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Find video protocols related to scientific articles indexed in Pubmed.
Can Urinary PCA3 Supplement PSA in the Early Detection of Prostate Cancer?
J. Clin. Oncol.
PUBLISHED: 11-12-2014
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Given the limited sensitivity and specificity of prostate-specific antigen (PSA), its widespread use as a screening tool has raised concerns for the overdiagnosis of low-risk and the underdiagnosis of high-grade prostate cancer. To improve early-detection biopsy decisions, the National Cancer Institute conducted a prospective validation trial to assess the diagnostic performance of the prostate cancer antigen 3 (PCA3) urinary assay for the detection of prostate cancer among men screened with PSA.
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Group 9 Organometallic Compounds for Therapeutic and Bioanalytical Applications.
Acc. Chem. Res.
PUBLISHED: 11-05-2014
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Conspectus Compared with organic small molecules, metal complexes offer several distinct advantages as therapeutic agents or biomolecular probes. Carbon atoms are typically limited to linear, trigonal planar, or tetrahedral geometries, with a maximum of two enantiomers being formed if four different substituents are attached to a single carbon. In contrast, an octahedral metal center with six different substituents can display up to 30 different stereoisomers. While platinum- and ruthenium-based anticancer agents have attracted significant attention in the realm of inorganic medicinal chemistry over the past few decades, group 9 complexes (i.e., iridium and rhodium) have garnered increased attention in therapeutic and bioanalytical applications due to their adjustable reactivity (from kinetically liable to substitutionally inert), high water solubility, stability to air and moisture, and relative ease of synthesis. In this Account, we describe our efforts in the development of group 9 organometallic compounds of general form [M(C(?)N)2(N(?)N)] (where M = Ir, Rh) as therapeutic agents against distinct biomolecular targets and as luminescent probes for the construction of oligonucleotide-based assays for a diverse range of analytes. Earlier studies by researchers had focused on organometallic iridium(III) and rhodium(III) half-sandwich complexes that show promising anticancer activity, although their precise mechanisms of action still remain unknown. More recently, kinetically-inert group 9 complexes have arisen as fascinating alternatives to organic small molecules for the specific targeting of enzyme activity. Research in our laboratory has shown that cyclometalated octahedral rhodium(III) complexes were active against Janus kinase 2 (JAK2) or NEDD8-activating enzyme (NAE) activity, or against NO production leading to antivasculogenic activity in cellulo. At the same time, recent interest in the development of small molecules as modulators of protein-protein interactions has stimulated our research group to investigate whether kinetically-inert metal complexes could also be used to target protein-protein interfaces relevant to the pathogenesis of certain diseases. We have recently discovered that cyclometalated octahedral iridium(III) and rhodium(III) complexes bearing C(?)N ligands based on 2-phenylpyridine could function as modulators of protein-protein interactions, such as TNF-?, STAT3, and mTOR. One rhodium(III) complex antagonized STAT3 activity in vitro and in vivo and displayed potent antitumor activity in a mouse xenograft model of melanoma. Notably, these studies were among the first to demonstrate the direct inhibition of protein-protein interfaces by kinetically-inert group 9 metal complexes. Additionally, we have discovered that group 9 solvato complexes carrying 2-phenylpyridine coligands could function as inhibitors and probes of ?-amyloid fibrillogenesis. Meanwhile, the rich photophysical properties of iridium complexes have made them popular tools for the design of luminescent labels and probes. Luminescent iridium(III) complexes benefit from a high quantum yield, responsive emissive properties, long-lived phosphorescence lifetimes, and large Stokes shift values. Over the past few years, our group has developed a number of kinetically-inert, organometallic iridium(III) complexes bearing various C(?)N and N(?)N ligands that are selective for G-quadruplex DNA, which is a DNA secondary structure formed from planar stacks of guanine tetrads stabilized by Hoogsteen hydrogen bonding. These complexes were then employed to develop G-quadruplex-based, label-free luminescence switch-on assays for nucleic acids, enzyme activity, small molecules, and metal ions.
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Assessment of HBV Preventive Services in a Medically Underserved Asian and Pacific Islander Population Using Provider and Patient Data.
J Gen Intern Med
PUBLISHED: 09-24-2014
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Hepatitis B (HBV) represents a significant health disparity among medically underserved Asian and Hawaiian/Pacific Islander (API) populations. Studies evaluating adherence to HBV screening and vaccination guidelines in this population are limited.
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Virtual screening and optimization of Type II inhibitors of JAK2 from a natural product library.
Chem. Commun. (Camb.)
PUBLISHED: 09-17-2014
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Amentoflavone has been identified as a JAK2 inhibitor by structure-based virtual screening of a natural product library. In silico optimization using the DOLPHIN model yielded analogues with enhanced potency against JAK2 activity and HCV activity in cellulo. Molecular modeling and kinetic experiments suggested that the analogues may function as Type II inhibitors of JAK2.
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Systematic review of efficacy and outcomes of salvage liver transplantation after primary hepatic resection for hepatocellular carcinoma.
J. Gastroenterol. Hepatol.
PUBLISHED: 09-11-2014
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Upfront liver transplantation is the gold standard in the treatment of patients with hepatocellular carcinoma (HCC) and cirrhosis, but a shortage of donor organs negatively impacts on survival outcomes, with significant disease progression during long waiting lists. This systematic review evaluates the safety and efficacy of salvage liver transplantation (SLT) as treatment for recurrent HCC after initial hepatic resection.
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Discovery of a small-molecule inhibitor of STAT3 by ligand-based pharmacophore screening.
Methods
PUBLISHED: 08-24-2014
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STAT3 modulates the transcription of a wide variety of regulatory genes involved in cell proliferation, differentiation, migration, apoptosis, and other critical cellular functions. Constitutive activation of STAT3 has been detected in a wide spectrum of human malignancies. A pharmacophore model constructed from a training set of STAT3 inhibitors binding to the SH2 domain was used to screen an in-house database of compounds, from which azepine 1 emerged as a top candidate. Compound 1 inhibited STAT3 DNA-binding activity in vitro and attenuated STAT3-directed transcription in cellulo with comparable potency to the well-known STAT3 inhibitor S3I-201. A fluorescence polarization assay revealed that compound 1 targeted the SH2 domain of STAT3. Furthermore, compound 1 inhibited STAT3 phosphorylation in cells without affecting the total expression of STAT3. This study also validates the use of pharmacophore modeling to identify inhibitors of protein-protein interactions.
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Glycoproteins identified from heart failure and treatment models.
Proteomics
PUBLISHED: 08-20-2014
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Conduction abnormalities can lead to dyssynchronous contraction, which significantly worsens morbidity and mortality of heart failure. Cardiac resynchronization therapy (CRT) can reverse ventricular remodeling and improve cardiac function. Although the underlying molecular changes are unknown, the use of a canine model of dyssynchronous heart failure (DHF) and CRT has shown that there are global changes across the cardiac proteome. This study determines changes in serum glycoprotein concentration from DHF and CRT compared to normal. We hypothesize that CRT invokes protective or advantageous pathways that can be reflected in the circulating proteome. Two prong discovery approaches were carried out on pooled normal, DHF, and CRT samples composed of individual canine serum to determine the overall protein concentration and the N-linked glycosites of circulating glycoproteins. The level of the glycoproteins was altered in DHF and CRT compared to control sera, with 63 glycopeptides substantially increased in DHF and/or CRT. Among the 32 elevated glycosite-containing peptides in DHF, 13 glycopeptides were reverted to normal level after CRT therapy. We further verify the changes of glycopeptides using label-free LC-MS from individual canine serum. Circulating glycoproteins such as alpha-fetoprotein, alpha-2-macroglobulin, galectin-3-binding protein, and collectin-10 show association to failing heart and CRT treatment model.
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Pharmacophore modeling for the identification of small-molecule inhibitors of TACE.
Methods
PUBLISHED: 08-08-2014
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Tumor necrosis factor ?-converting enzyme (TACE) plays a critical role in diverse physiological processes such as inflammation, hematopoiesis, and development. In this study, a pharmacophore model constructed from a training set of TACE inhibitors was used to screen an in-house database of organic compounds, from which compound 1 emerged as a top candidate. In a cell-free assay, compound 1 inhibited TACE enzymatic activity in a dose-dependent manner. Moreover, compound 1 inhibited the production of soluble TNF-? in human acute monocytic leukemia THP-1 cells without impacting nitric oxide production, and exhibited anti-proliferative activity against THP-1 cells. We envisage that compound 1 may be employed as a useful scaffold for the development of more potent TACE inhibitors. This study also validates the use of pharmacophore modeling to identify enzyme inhibitors.
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Visualization of Zn²? ions in live zebrafish using a luminescent iridium(III) chemosensor.
ACS Appl Mater Interfaces
PUBLISHED: 08-01-2014
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A novel luminescent cyclometalated iridium(III) complex-based chemosensor (1) bearing a zinc-specific receptor, tris(2-pyridylmethyl)amine, and the 3-phenyl-1H-pyrazole ligand has been designed and synthesized. Upon the addition of Zn(2+) ions to a solution of iridium(III) complex 1, a pronounced luminescence color change from blue to green can be observed, which may be attributed to the suppression of photoinduced electron transfer upon complexation of complex 1 with Zn(2+) ions. The interaction of iridium(III) complex 1 with Zn(2+) ions was investigated by UV-vis absorption titration, emission titration, and (1)H NMR titration. Furthermore, the iridium(III) complex 1 exhibited good selectivity for Zn(2+) over 13 other common metal ions, including K(+), Ag(+), Na(+), Ni(2+), Fe(3+), Hg(2+), Cd(2+), Mg(2+), Ca(2+), Cu(2+), Mn(2+), Co(2+), and Pb(2+) ions. The practical application of the iridium(III) complex 1 in visualizing intracellular Zn(2+) distribution in live zebrafish was also demonstrated.
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Effect of Distal Interlocking Screw Number and Position after Intramedullary Nailing of Distal Tibial Fractures: A Biomechanical Study Simulating Immediate Weight-Bearing.
J Orthop Trauma
PUBLISHED: 07-30-2014
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To quantify the changes in biomechanical stability conferred by the addition of a single medial blocking screw or a single bi-cortical interlocking screw to two existing distal points of screw fixation in a distal tibial fracture model repaired with intramedullary nailing.
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Management of acute kidney injury with continuous veno-venous haemodiafiltration in a cat.
J. Feline Med. Surg.
PUBLISHED: 07-03-2014
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Continuous renal replacement therapy is an emerging technique for the treatment of acute kidney injury (AKI). Data regarding its use in cats are limited. This report describes the use of a novel continuous renal replacement therapy (CRRT) system for the treatment of AKI in a cat. A 1.3-year-old cat developed uraemic signs following the administration of a non-steroidal anti-inflammatory agent for the treatment of a suspect traumatic episode. CRRT was provided with a Prismaflex Gambro machine used in continuous veno-venous haemodiafiltration mode, with an AN-69 surface-treated membrane, synthetic colloid priming and heparin anticoagulation. Two treatment cycles were performed totalling 51 h of CRRT. The treatment was effective in controlling uraemic signs, and no major complications were noted. Owing to financial constrains the owners declined further CRRT treatments, and on day 8 of hospitalisation, owing to the lack of significant clinical improvement, humane euthanasia was performed. The set-up detailed in this report provides a viable option for the initial treatment of cats with AKI.
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A colorimetric chemosensor for Cu(2+) ion detection based on an iridium(III) complex.
Sci Rep
PUBLISHED: 07-01-2014
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We report herein the synthesis and application of a series of novel cyclometalated iridium(III) complexes 1-3 bearing a rhodamine-linked NˆN ligand for the detection of Cu(2+) ions. Under the optimised conditions, the complexes exhibited high sensitivity and selectivity for Cu(2+) ions over a panel of other metal ions, and showed consistent performance in a pH value range of 6 to 8. Furthermore, the potential application of this system for the monitoring of Cu(2+) ions in tap water or natural river water samples was demonstrated.
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In silico identification of natural product inhibitors of JAK2.
Methods
PUBLISHED: 06-02-2014
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Emodic acid (1) and 6-chloroemodic acid (2) have been identified from a natural product database as useful scaffolds for the future development of novel JAK2 inhibitors using structure-based high-throughput virtual screening. Low-energy binding conformations of 1 and 2 in the JAK2 PTK domain were generated by virtual ligand docking and were found to overlap considerably with the binding pose of CMP6, a known JAK2 inhibitor. Compounds 1 and 2 displayed low micromolar efficacies against JAK2 enzyme activity and JAK2 autophosphorylation in human erythroleukemia cells, and inhibited STAT3 DNA-binding activity in a human hepatocarcinoma cell line.
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Discovery of deoxyvasicinone derivatives as inhibitors of NEDD8-activating enzyme.
Methods
PUBLISHED: 05-31-2014
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NEDD8-activating enzyme (NAE) controls the specific degradation of proteins regulated by cullin-RING ubiquitin E3 ligases, and has been considered as an attractive molecular target for the development of drugs against cancer. A pharmacophore model constructed from a training set of deoxyvasicinone derivatives was used to screen 376 compounds from an analogue database. From the initial screening, the valine-linked deoxyvasicinone derivative 9 and the N-isopropyl-linked deoxyvasicinone derivative 10 emerged as the top scoring candidates. Compounds 9 and 10 showed micromolar potencies in both cell-free and cell-based systems, with selectivity for NAE over the related enzymes SAE and UAE. Molecular modelling analysis suggested that 9 and 10 may inhibit NAE by blocking the ATP-binding domain. Thus, these deoxyvasicinone derivatives could be considered as promising lead molecules for the development of more potent inhibitors of NAE.
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A rhodium(III) complex inhibits LPS-induced nitric oxide production and angiogenic activity in cellulo.
J. Inorg. Biochem.
PUBLISHED: 05-25-2014
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Metal-containing complexes have arisen as viable alternatives to organic molecules as therapeutic agents. Metal complexes possess a number of advantages compared to conventional carbon-based compounds, such as distinct geometries, interesting electronic properties, variable oxidation states and the ability to arrange different ligands around the metal centre in a precise fashion. Meanwhile, nitric oxide (NO) plays key roles in the regulation of angiogenesis, vascular permeability and inflammation. We herein report a novel cyclometalated rhodium(III) complex as an inhibitor of lipopolysaccharides (LPS)-induced NO production in RAW264.7 macrophages. Experiments suggested that the inhibition of NO production in cells by complex 1 was mediated through the down-regulation of nuclear factor-?B (NF-?B) activity. Furthermore, complex 1 inhibited angiogenesis in human umbilical vein endothelial cells (HUVECs) as revealed by an endothelial tube formation assay. This study demonstrates that kinetically inert rhodium(III) complexes may be potentially developed as effective anti-angiogenic agents.
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An oligonucleotide-based label-free luminescent switch-on probe for RNA detection utilizing a G-quadruplex-selective iridium(III) complex.
Nanoscale
PUBLISHED: 05-13-2014
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We report herein the synthesis and application of a novel G-quadruplex-selective luminescent iridium(iii) complex for the construction of an oligonucleotide-based, label-free, rapid and convenient luminescent RNA detection platform.
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STAT3 down regulates LC3 to inhibit autophagy and pancreatic cancer cell growth.
Oncotarget
PUBLISHED: 05-07-2014
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The dismal 5-year survival (<5%) for pancreatic cancer (PanCA) underscores the need for developing effective therapeutic options. Recent studies from our laboratory have shown that Nexrutine® (Nx), a bark extract from Phellodendron amurense exhibits excellent anticancer activity in human pancreatic cancer cells through inhibition of inflammatory signaling via STAT3/NF?B/Cox-2. Given the apparent high oxidative stress and autophagic activity in pancreatic tumors, we investigated the potential of Nx to modulate autophagy, reactive oxygen species (ROS), and their crosstalk. Our results show that Nx inhibits autophagy and decreases ROS generation. Pharmacological inhibition of autophagy led to decreased ROS generation and proliferation with no significant effect on apoptosis. Further, using combination index analysis we also found that combination of late-stage autophagy inhibitor with Nx exhibited a moderate synergistic to additive effect. Additionally, genetic or pharmacological inactivation of STAT3 reduced LC3-II levels and expression indicating a possible role for STAT3 in transcriptional regulation of autophagy. Since both inflammatory and oxidative stress signaling activate STAT3, our data implicates that STAT3 plays a vital role in the regulation of autophagy through its contributions to the positive feedback loop between ROS and autophagy. Overall, our findings reveal an important role for STAT3/LC3/ROS in Nx-mediated anti-pancreatic cancer effects.
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Antagonizing STAT3 dimerization with a rhodium(III) complex.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 04-25-2014
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Kinetically inert metal complexes have arisen as promising alternatives to existing platinum and ruthenium chemotherapeutics. Reported herein, to our knowledge, is the first example of a substitutionally inert, Group?9 organometallic compound as a direct inhibitor of signal transducer and activator of transcription?3 (STAT3) dimerization. From a series of cyclometalated rhodium(III) and iridium(III) complexes, a rhodium(III) complex emerged as a potent inhibitor of STAT3 that targeted the SH2 domain and inhibited STAT3 phosphorylation and dimerization. Significantly, the complex exhibited potent anti-tumor activities in an in?vivo mouse xenograft model of melanoma. This study demonstrates that rhodium complexes may be developed as effective STAT3 inhibitors with potent anti-tumor activity.
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Ischemia in tumors induces early and sustained phosphorylation changes in stress kinase pathways but does not affect global protein levels.
Mol. Cell Proteomics
PUBLISHED: 04-09-2014
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Protein abundance and phosphorylation convey important information about pathway activity and molecular pathophysiology in diseases including cancer, providing biological insight, informing drug and diagnostic development, and guiding therapeutic intervention. Analyzed tissues are usually collected without tight regulation or documentation of ischemic time. To evaluate the impact of ischemia, we collected human ovarian tumor and breast cancer xenograft tissue without vascular interruption and performed quantitative proteomics and phosphoproteomics after defined ischemic intervals. Although the global expressed proteome and most of the >25,000 quantified phosphosites were unchanged after 60 min, rapid phosphorylation changes were observed in up to 24% of the phosphoproteome, representing activation of critical cancer pathways related to stress response, transcriptional regulation, and cell death. Both pan-tumor and tissue-specific changes were observed. The demonstrated impact of pre-analytical tissue ischemia on tumor biology mandates caution in interpreting stress-pathway activation in such samples and motivates reexamination of collection protocols for phosphoprotein analysis.
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Tissue Proteomics Using Chemical Immobilization and Mass Spectrometry.
Anal. Biochem.
PUBLISHED: 04-02-2014
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Proteomics analysis is important for characterizing tissues to gain biological and pathological insights, which could lead to the identification of disease-associated proteins for disease diagnostics or targeted therapy. However, tissues are commonly embedded in optimal cutting temperature compound (OCT) or they are formalin-fixed and paraffin-embedded (FFPE) in order to maintain tissue morphology for histology evaluation. Although several tissue proteomics analyses have been performed on FFPE tissues using advanced mass spectrometry technologies, high throughput proteomic analysis of OCT-embedded tissues has been difficult due to the interference of OCT in the mass spectrometry analysis. In addition, molecules other than proteins present in tissues further complicate tissue proteomic analysis. Herein, we report the development of a method using Chemical Immobilization of Proteins for Peptide Extraction (CIPPE). In this method, proteins are chemically immobilized onto a solid support; interferences from tissues and OCT embedding are removed by extensive washing of proteins conjugated on the solid support. Peptides are then released from the solid phase by proteolysis, enabling mass spectrometry analysis. This method was first validated by eliminating OCT interference from a standard protein, human serum albumin, where all the unique peaks contributed by OCT contamination were eradicated. Finally, this method was applied for the proteomic analysis of frozen and OCT-embedded tissues using iTRAQ labeling and 2D liquid chromatography tandem mass spectrometry. The data showed reproducible extraction and quantitation of 10,284 proteins from 3,996 protein groups and a minimal impact of OCT embedding on the analysis of the global proteome of the stored tissue samples.
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Wound complications associated with bone morphogenetic protein-2 in orthopaedic trauma surgery.
J Orthop Trauma
PUBLISHED: 04-01-2014
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To document the incidence of postoperative wound complications associated with the use of rhBMP-2 in a large series of patients for both acute traumatic and reconstructive extremity cases.
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Shining a new narrow band of light on old problems.
Am. J. Gastroenterol.
PUBLISHED: 03-31-2014
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Improvements in narrow band imaging (NBI) may provide an improved view of colonic mucosa for detection of polyps and adenomas. In this issue, Leung et al. report findings to suggest that this next-generation NBI technology is superior to conventional high-definition white light endoscopy in polyp detection. These findings are based on brighter illumination, which has been a problem with older generations of NBI, which did not increase polyp detection but were useful for polyp characterization. Although these findings are very promising for this new role of second-generation NBI in polyp detection, the study must be viewed with consideration of the history of the older NBI system, the analysis of which through multiple positive and negative studies ultimately led to the conclusion that it was not beneficial for detection.
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Proteomic cancer biomarkers from discovery to approval: it's worth the effort.
Expert Rev Proteomics
PUBLISHED: 03-21-2014
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The current landscape of cancer biomarkers is changing rapidly, with new and exciting developments. With the advances of proteomic technologies, many potential cancer biomarkers have been discovered. However, the number of new cancer biomarkers cleared or approved by the US FDA is rather limited. Although technological advances are important, clearly defining intended use, good study design and appropriate patient specimens are critical for the success of FDA approval. While obtaining FDA clearance/approval for newly developed and clinically useful cancer biomarkers has been slow, the reward for patient care could be enormous.
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Biomarkers in prostate cancer: what's new?
Curr Opin Oncol
PUBLISHED: 03-15-2014
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This review is intended to provide an overview of the current state of biomarkers for prostate cancer (PCa), with a focus on biomarkers approved by the US Food and Drug Administration (FDA) as well as biomarkers available from Clinical Laboratory Improvement Amendment (CLIA)-certified clinical laboratories within the last 1-2 years.
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SILAC-based quantitative proteomic analysis of secretome between activated and reverted hepatic stellate cells.
Proteomics
PUBLISHED: 03-14-2014
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Activated hepatic stellate cell (HSC) is the main myofibroblast cell in the liver fibrosis (LF). An important characteristic of the recovery of LF is not only the apoptosis of activated HSCs but also reversal of myofibroblast-like phenotype to a quiescent-like phenotype. Understanding the changes of secreted proteins in the reversion of activated HSCs may provide the broader view of cellular regulatory networks and discover candidate markers or targets for therapeutic strategies of LF. In this study, stable isotope labeling with amino acids (SILAC) combined with linear ion trap-Fourier transform ion cyclotron resonance mass spectrometer (LTQ-FT MS) was performed on in vitro activated HSCs and reverted HSCs to obtain a proteomic view of secretory proteins. In total, 330 proteins showed significant differences in reverted HSCs. Among these, 109 upregulated proteins were mainly involved in amino acid metabolism pathway and glucose metabolism pathway using GeneGO/MetaCore software, while 221 downregulated proteins are closely associated with HSCs activation, such as cytoskeleton remodeling, chemokines, and cell adhesion. Additionally, a set of novel proteins associated with HSCs activation and reversion were validated by Western blotting in the cell secretion and in the sera of LF, including vitronectin, laminin beta 1, and ubiquitin conjugation factor E4B. Our study provided the valuable insight into the mechanisms in the reversion of activated HSCs and identified some potential biomarkers of LF in clinical studies. All MS data have been deposited in the ProteomeXchange with identifier PXD000773 (http://proteomecentral.proteomexchange.org/dataset/PXD000773).
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Nutritional management of acute pancreatitis in dogs and cats.
J Vet Emerg Crit Care (San Antonio)
PUBLISHED: 02-17-2014
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To review current and emerging nutritional approaches in the management of acute pancreatitis (AP) in people, dogs, and cats, and to provide a framework for further investigation in this field.
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Systematic evaluation of evidence on veterinary viscoelastic testing part 4: Definitions and data reporting.
J Vet Emerg Crit Care (San Antonio)
PUBLISHED: 01-30-2014
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To systematically examine evidence surrounding definitions and reporting of data for viscoelastic testing in veterinary medicine.
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Structure-based repurposing of FDA-approved drugs as inhibitors of NEDD8-activating enzyme.
Biochimie
PUBLISHED: 01-17-2014
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We report the discovery of an inhibitor of NEDD8-activating enzyme (NAE) by an integrated virtual screening approach. Piperacillin 1 inhibited NAE activity in cell-free and cell-based systems with high selectivity. Furthermore, piperacillin 1 was able to inhibit the degradation of the NAE downstream protein substrate p27(kip1). Our molecular modeling and kinetic studies suggested that this compound may act as a non-covalent ATP-competitive inhibitor of NAE.
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Targeted peptide measurements in biology and medicine: best practices for mass spectrometry-based assay development using a fit-for-purpose approach.
Mol. Cell Proteomics
PUBLISHED: 01-17-2014
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Adoption of targeted mass spectrometry (MS) approaches such as multiple reaction monitoring (MRM) to study biological and biomedical questions is well underway in the proteomics community. Successful application depends on the ability to generate reliable assays that uniquely and confidently identify target peptides in a sample. Unfortunately, there is a wide range of criteria being applied to say that an assay has been successfully developed. There is no consensus on what criteria are acceptable and little understanding of the impact of variable criteria on the quality of the results generated. Publications describing targeted MS assays for peptides frequently do not contain sufficient information for readers to establish confidence that the tests work as intended or to be able to apply the tests described in their own labs. Guidance must be developed so that targeted MS assays with established performance can be made widely distributed and applied by many labs worldwide. To begin to address the problems and their solutions, a workshop was held at the National Institutes of Health with representatives from the multiple communities developing and employing targeted MS assays. Participants discussed the analytical goals of their experiments and the experimental evidence needed to establish that the assays they develop work as intended and are achieving the required levels of performance. Using this "fit-for-purpose" approach, the group defined three tiers of assays distinguished by their performance and extent of analytical characterization. Computational and statistical tools useful for the analysis of targeted MS results were described. Participants also detailed the information that authors need to provide in their manuscripts to enable reviewers and readers to clearly understand what procedures were performed and to evaluate the reliability of the peptide or protein quantification measurements reported. This paper presents a summary of the meeting and recommendations.
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Health service management study for stroke: a randomized controlled trial to evaluate two models of stroke care.
Int J Stroke
PUBLISHED: 01-03-2014
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The most effective and efficient model for providing organized stroke care remains uncertain. This study aimed to compare the effect of two models in a randomized controlled trial.
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Mechanisms by which low glucose enhances the cytotoxicity of metformin to cancer cells both in vitro and in vivo.
PLoS ONE
PUBLISHED: 01-01-2014
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Different cancer cells exhibit altered sensitivity to metformin treatment. Recent studies suggest these findings may be due in part to the common cell culture practice of utilizing high glucose, and when glucose is lowered, metformin becomes increasingly cytotoxic to cancer cells. In low glucose conditions ranging from 0 to 5 mM, metformin was cytotoxic to breast cancer cell lines MCF7, MDAMB231 and SKBR3, and ovarian cancer cell lines OVCAR3, and PA-1. MDAMB231 and SKBR3 were previously shown to be resistant to metformin in normal high glucose medium. When glucose was increased to 10 mM or above, all of these cell lines become less responsive to metformin treatment. Metformin treatment significantly reduced ATP levels in cells incubated in media with low glucose (2.5 mM), high fructose (25 mM) or galactose (25 mM). Reductions in ATP levels were not observed with high glucose (25 mM). This was compensated by enhanced glycolysis through activation of AMPK when oxidative phosphorylation was inhibited by metformin. However, enhanced glycolysis was either diminished or abolished by replacing 25 mM glucose with 2.5 mM glucose, 25 mM fructose or 25 mM galactose. These findings suggest that lowering glucose potentiates metformin induced cell death by reducing metformin stimulated glycolysis. Additionally, under low glucose conditions metformin significantly decreased phosphorylation of AKT and various targets of mTOR, while phospho-AMPK was not significantly altered. Thus inhibition of mTOR signaling appears to be independent of AMPK activation. Further in vivo studies using the 4T1 breast cancer mouse model confirmed that metformin inhibition of tumor growth was enhanced when serum glucose levels were reduced via low carbohydrate ketogenic diets. The data support a model in which metformin treatment of cancer cells in low glucose medium leads to cell death by decreasing ATP production and inhibition of survival signaling pathways. The enhanced cytotoxicity of metformin against cancer cells was observed both in vitro and in vivo.
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A colorimetric and luminescent dual-modal assay for Cu(II) ion detection using an iridium(III) complex.
PLoS ONE
PUBLISHED: 01-01-2014
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A novel iridium(III) complex-based chemosensor bearing the 5,6-bis(salicylideneimino)-1,10-phenanthroline ligand receptor was developed, which exhibited a highly sensitive and selective color change from colorless to yellow and a visible turn-off luminescence response upon the addition of Cu(II) ions. The interactions of this iridium(III) complex with Cu2+ ions and thirteen other cations have been investigated by UV-Vis absorption titration, emission titration, and 1H NMR titration.
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Discovery of a natural product-like iNOS inhibitor by molecular docking with potential neuroprotective effects in vivo.
PLoS ONE
PUBLISHED: 01-01-2014
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In this study, we applied structure-based virtual screening techniques to identify natural product or natural product-like inhibitors of iNOS. The iNOS inhibitory activity of the hit compounds was characterized using cellular assays and an in vivo zebrafish larvae model. The natural product-like compound 1 inhibited NO production in LPS-stimulated Raw264.7 macrophages, without exerting cytotoxic effects on the cells. Significantly, compound 1 was able to reverse MPTP-induced locomotion deficiency and neurotoxicity in an in vivo zebrafish larval model. Hence, compound 1 could be considered as a scaffold for the further development of iNOS inhibitors for potential anti-inflammatory or anti-neurodegenerative applications.
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Label-free luminescence switch-on detection of T4 polynucleotide kinase activity using a G-quadruplex-selective probe.
Chem. Commun. (Camb.)
PUBLISHED: 12-16-2013
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A label-free, oligonucleotide-based, switch-on luminescence detection method for T4 polynucleotide kinase activity has been developed using a novel G-quadruplex-selective luminescent Ir(iii) complex probe. The application of the assay for screening potential T4 PNK inhibitors is also demonstrated. To our knowledge, this is the first metal-based assay for PNK activity.
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Oculopharyngeal muscular dystrophy: underdiagnosed disease in Hong Kong.
Hong Kong Med J
PUBLISHED: 12-07-2013
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Despite the advances in the understanding of the molecular basis for oculopharyngeal muscular dystrophy in the last decade, it remains an underdiagnosed disease, especially among the Chinese. In the presence of a positive family history and late-onset ptosis, dysphagia, and proximal muscle weakness (its cardinal features), we suggest that PABPN1 gene analysis should be the first-line investigation to rule out this condition. Muscle biopsy can be reserved for atypical cases. Non-specific mitochondrial changes in the muscle specimens of these patients should be appreciated, so as to avoid diagnostic confusion. It is hoped that greater awareness among medical professionals and judicious use of PABPN1 gene analysis will lead to earlier diagnosis, better management, and avoidance of unnecessary invasive investigations of affected patients.
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A Highly Sensitive Targeted Mass Spectrometric Assay for Quantification of AGR2 Protein in Human Urine and Serum.
J. Proteome Res.
PUBLISHED: 12-03-2013
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Anterior gradient 2 (AGR2) is a secreted, cancer-associated protein in many types of epithelial cancer cells. We developed a highly sensitive targeted mass spectrometric assay for quantification of AGR2 in urine and serum. Digested peptides from clinical samples were processed by PRISM (high pressure and high resolution separations coupled with intelligent selection and multiplexing), which incorporates high pH reversed-phase liquid chromatography (LC) separations to fractionate and select target fractions for follow-on LC-selected reaction monitoring (LC-SRM) analyses. The PRISM-SRM assay for AGR2 showed a reproducibility of <10% CV and limit of quantification (LOQ) values of ?130 pg/mL in serum and ?10 pg per 100 ?g of total protein mass in urine, respectively. A good correlation (R(2) = 0.91) was observed for the measurable AGR2 concentrations in urine between SRM and enzyme-linked immunosorbent assay (ELISA). On the basis of an initial cohort of 37 subjects, urinary AGR2/PSA concentration ratios showed a significant difference (P = 0.026) between noncancer and cancer. Large clinical cohort studies are needed for the validation of AGR2 as a useful diagnostic biomarker for prostate cancer. Our work validated the approach of identifying candidate secreted protein biomarkers through genomics and measurement by targeted proteomics, especially for proteins where no immunoassays are available.
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Label-Free Luminescent Switch-on Detection of Endonuclease IV Activity Using a G-Quadruplex-Selective Iridium(III) Complex.
ACS Appl Mater Interfaces
PUBLISHED: 11-22-2013
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We report herein the synthesis and application of a novel G-quadruplex-selective luminescent iridium(III) complex [Ir(ppy)2(bcp)](+) (where ppy = 2-phenylpyridine and bcp = 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) for the sensitive detection of apurinic/apyrimidinic (AP) endonuclease activity. Using endonuclease IV (Endo IV) as a model enzyme, a duplex DNA substrate containing a G-quadruplex-forming sequence is cleaved by Endo IV at the abasic site. This releases the G-quadruplex sequence, which folds into a G-quadruplex and is recognised by the G-quadruplex-selective iridium(III) complex with an enhanced luminescence response. The assay achieved high sensitivity and selectivity for Endo IV over other tested enzymes.
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Analysis of N-glycoproteins using genomic N-glycosite prediction.
J. Proteome Res.
PUBLISHED: 11-15-2013
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Protein glycosylation has long been recognized as one of the most common post-translational modifications. Most membrane proteins and extracellular proteins are N-linked glycosylated, and they account for the majority of current clinical diagnostic markers or therapeutic targets. Quantitative proteomic analysis of detectable N-linked glycoproteins from cells or tissues using mass spectrometry has the potential to provide biological basis for disease development and identify disease associated glycoproteins. However, the information of low abundance but important peptides is lost due to the lack of MS/MS fragmentation or low quality of MS/MS spectra for low abundance peptides. Here, we show the feasibility of formerly N-glycopeptide identification and quantification at MS1 level using genomic N-glycosite prediction (GenoGlyco) coupled with stable isotopic labeling and accurate mass matching. The GenoGlyco Analyzer software uses accurate precursor masses of detected N-deglycopeptide peaks to match them to N-linked deglycopeptides that are predicted from genes expressed in the cells. This method results in more robust glycopeptide identification compared to MS/MS-based identification. Our results showed that over three times the quantity of N-deglycopeptide assignments from the same mass spectrometry data could be produced in ovarian cancer cell lines compared to a MS/MS fragmentation method. Furthermore, the method was also applied to N-deglycopeptide analysis of ovarian tumors using the identified deglycopeptides from the two ovarian cell lines as heavy standards. We show that the described method has a great potential in the analysis of detectable N-glycoproteins from cells and tissues.
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Prognostic Value of Preoperative Right Ventricular Geometry and Tricuspid Valve Tethering Area in Patients Undergoing Tricuspid Annuloplasty.
Circulation
PUBLISHED: 09-25-2013
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Patients who undergo tricuspid annuloplasty (TA) during left heart valve surgery have a poor postoperative clinical outcome. Nonetheless, preoperative right ventricular (RV) echocardiography parameters that predict adverse events in these patients are poorly understood.
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Development and pilot of an advance care planning website for women with ovarian cancer: a randomized controlled trial.
Gynecol. Oncol.
PUBLISHED: 07-25-2013
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Few available tools facilitate cancer patients and physicians discussions of quality of life and end-of-life. Our objective was to develop a web-based tool to promote advance care planning for women with ovarian cancer.
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Glycoproteomic analysis of bronchoalveolar lavage (BAL) fluid identifies tumor-associated glycoproteins from lung adenocarcinoma.
J. Proteome Res.
PUBLISHED: 07-11-2013
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Cytological examination of cells from bronchoalveolar lavage (BAL) is commonly used for the diagnosis of lung cancer. Proteins released from lung cancer cells into BAL may serve as biomarkers for cancer detection. In this study, N-glycoproteins in eight cases of BAL fluid, as well as eight lung adenocarcinoma tissues and eight tumor-matched normal lung tissues, were analyzed using the solid-phase extraction of N-glycoprotein (SPEG), iTRAQ labeling, and liquid chromatography tandem mass spectrometry (LC-MS/MS). Of 80 glycoproteins found in BAL specimens, 32 were identified in both cancer BAL and cancer tissues, with levels of 25 glycoproteins showing at least a 2-fold difference between cancer and benign BAL. Among them, eight glycoproteins showed greater than 2-fold elevations in cancer BAL, including Neutrophil elastase (NE), Integrin alpha-M, Cullin-4B, Napsin A, lysosome-associated membrane protein 2 (LAMP2), Cathepsin D, BPI fold-containing family B member 2, and Neutrophil gelatinase-associated lipocalin. The levels of Napsin A in cancer BAL were further verified in independently collected 39 BAL specimens using an ELISA assay. Our study demonstrates that potential protein biomarkers in BAL fluid can be detected and quantified.
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Detection of 3?5 exonuclease activity using a metal-based luminescent switch-on probe.
Methods
PUBLISHED: 06-28-2013
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A luminescent iridium(III) complex has been discovered to be selective for G-quadruplex DNA, and was employed in a label-free G-quadruplex-based detection assay for 3?5 exonuclease activity in aqueous solution. A proof-of-concept of this assay has been demonstrated by using prokaryotic exonuclease III (ExoIII) as a model enzyme. In this assay, a G-quadruplex-forming hairpin oligonucleotide (hairpin-G4 DNA, 5-GAG3TG4AG3TG4A2GCAGA2G2ATA2CT2C4AC3TC4AC3TC-3) initially exists in a duplex conformation, resulting in a low luminescence signal due to the weak interaction between the iridium(III) complex and duplex DNA. Upon digestion by ExoIII, the guanine-rich sequence is released and folds into a G-quadruplex, which greatly enhances the luminescence emission of the iridium(III) probe. This method was highly sensitive for 3?5 exonuclease over other DNA-modifying enzymes.
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Bioactive luminescent transition-metal complexes for biomedical applications.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 06-13-2013
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The serendipitous discovery of the anticancer drug cisplatin cemented medicinal inorganic chemistry as an independent discipline in the 1960s. Luminescent metal complexes have subsequently been widely applied for sensing, bio-imaging, and in organic light-emitting diode applications. Transition-metal complexes possess a variety of advantages that make them suitable as therapeutics and as luminescent probes for biomolecules. It is thus highly desirable to develop new luminescent metal complexes that either interact with DNA through different binding modes or target alternative cellular machinery such as proteins as well as to provide a more effective means of monitoring disease progression. In this Review, we highlight recent examples of biologically active luminescent metal complexes that can target and probe a specific biomolecule, and offer insights into the future potential of these compounds for the investigation and treatment of human diseases.
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Uptake and mitochondrial dysfunction of alpha-synuclein in human astrocytes, cortical neurons and fibroblasts.
Transl Neurodegener
PUBLISHED: 06-03-2013
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The accumulation and aggregation of alpha-synuclein (?-syn) in several tissue including the brain is a major pathological hallmark in Parkinsons disease (PD). In this study, we show that ?-syn can be taken up by primary human cortical neurons, astrocytes and skin-derived fibroblasts in vitro. Our findings that brain and peripheral cells exposed to ?-syn can lead to impaired mitochondrial function, leading to cellular degeneration and cell death, provides additional evidence for the involvement of mitochondrial dysfunction as a mechanism of toxicity of ?-syn in human cells.
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A parallel G-quadruplex-selective luminescent probe for the detection of nanomolar calcium(II) ion.
Methods
PUBLISHED: 06-02-2013
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A parallel G-quadruplex-selective iridium(III) complex has been synthesized and employed as a luminescent probe in a label-free G-quadruplex-based detection assay for Ca(2+) ions in aqueous solution. In this assay, a guanine-rich oligonucleotide (G4, 5-G4T4G4-3) initially exists in an antiparallel G-quadruplex conformation, resulting in a low luminescence signal. Upon incubation with Ca(2+) ions, the antiparallel G-quadruplex is induced into a parallel G-quadruplex conformation, which greatly enhances the luminescence emission of the iridium(III) probe. This method was highly sensitive for Ca(2+) ions with a limit of detection in the nanomolar range, and was selective for Ca(2+) over other metal ions.
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A luminescent G-quadruplex switch-on probe for the highly selective and tunable detection of cysteine and glutathione.
Chem. Commun. (Camb.)
PUBLISHED: 05-29-2013
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A G-quadruplex-selective luminescent iridium(III) switch-on probe has been developed for the detection of cysteine (Cys) in aqueous solution. The system is highly sensitive and selective towards Cys with a tunable range of detection. The detection of glutathione (GSH) is also examined.
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Glycoproteomics using fluid-based specimens in the discovery of lung cancer protein biomarkers: promise and challenge.
Proteomics Clin Appl
PUBLISHED: 05-29-2013
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Lung cancer is the leading cancer in the United States and worldwide. In spite of the rapid progression in personalized treatments, the overall survival rate of lung cancer patients is still suboptimal. Over the past decade, tremendous efforts have been focused on the discovery of protein biomarkers to facilitate the early detection and monitoring of lung cancer progression during treatment. In addition to tumor tissues and cancer cell lines, a variety of biological material has been studied. Particularly in recent years, studies using fluid-based specimen or so-called "fluid-biopsy" specimens have progressed rapidly. Fluid specimens are relatively easier to collect than tumor tissue, and they can be repeatedly sampled during the disease progression. Glycoproteins are the major content of fluid specimens and have long been recognized to play fundamental roles in many physiological and pathological processes. In this review, we focus the discussion on recent advances of glycoproteomics, particularly in the identification of potential glyco protein biomarkers using fluid-based specimens in lung cancer. The purpose of this review is to summarize current strategies, achievements, and perspectives in the field. This insight will highlight the discovery of tumor-associated glycoprotein biomarkers in lung cancer and their potential clinical applications.
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Alpha-synuclein transmission and mitochondrial toxicity in primary human foetal enteric neurons in vitro.
Neurotox Res
PUBLISHED: 05-27-2013
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Parkinsons disease (PD) is a multicentred neurodegenerative disorder characterised by the accumulation and aggregation of alpha-synuclein (?-syn) in several parts of the central nervous system. However, it is well established that PD can generate symptoms of constipation and other gastrointestinal problems and ?-syn containing lesions have been identified in intestinal nerve cells. In this study, we show that ?-syn can be taken up and accumulate in primary human foetal enteric neurons from the gastrointestinal tract and can be transferred between foetal enteric neurons. Impaired proteosomal/lysosomal degradation can promote the uptake and accumulation of ?-syn in enteric neurons. Enteric neurons exposed to ?-syn can also lead to impaired mitochondrial complex I activity, reduced mitochondrial function, and NAD(+) depletion culminating in cell death via energy restriction. These findings demonstrate neuron-to-neuron transmission of ?-syn in enteric neurons, providing renewed evidence for Braaks hypothesis and the aetiology of PD.
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Preferences, barriers and facilitators for establishing comprehensive stroke units: a multidisciplinary survey.
Aust Health Rev
PUBLISHED: 05-25-2013
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To determine the preferences of multidisciplinary stroke clinicians for models of inpatient stroke unit care and perceived barriers to establishing a comprehensive stroke unit (CSU) model (acute and rehabilitation care in the same ward).
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Impact of a multivariate index assay on referral patterns for surgical management of an adnexal mass.
Am. J. Obstet. Gynecol.
PUBLISHED: 05-24-2013
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To determine the impact on referral patterns of using a Multivariate Index Assay, CA125, modified-American College of Obstetricians and Gynecologists referral guidelines, and clinical assessment among patients undergoing surgery for an adnexal mass after initial evaluation by nongynecologic oncologists.
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A label-free G-quadruplex-based luminescent switch-on assay for the selective detection of histidine.
Methods
PUBLISHED: 05-17-2013
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A label-free G-quadruplex-based luminescent switch-on assay has been developed for the selective detection of micromolar histidine in aqueous solution. In this study, an iridium(III) complex was employed as a G-quadruplex-specific luminescent probe while a guanine-rich oligonucleotide (Pu27, 5-TG4AG3TG4AG3TG4A2G2-3)/cupric ion (Cu(2+)) ensemble was employed as a recognition unit for histidine. The initial luminescence of the iridium(III) complex in the presence of G-quadruplex DNA is effectively quenched by Cu(2+) ions due to the Cu(2+)-mediated unfolding of the G-quadruplex motif. The addition of histidine sequesters Cu(2+) ions from the ensemble, thereby restoring the luminescence of the system. The assay could detect down to 1?M of histidine in aqueous media, and also exhibited good selectivity for histidine over other amino acids with the use of the cysteine, masking agent N-ethylmaleimide. Furthermore, the application of the assay for the detection of histidine in diluted urine samples was demonstrated.
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Clinical performance of a multivariate index assay for detecting early-stage ovarian cancer.
Am. J. Obstet. Gynecol.
PUBLISHED: 04-30-2013
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We sought to analyze the effectiveness of a multivariate index assay (MIA) in identifying early-stage ovarian malignancy compared to clinical assessment, CA 125-II, and modified American Congress of Obstetricians and Gynecologists (ACOG) guidelines among women undergoing surgery for an adnexal mass.
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Belinostat and panobinostat (HDACI): in vitro and in vivo studies in thyroid cancer.
J. Cancer Res. Clin. Oncol.
PUBLISHED: 04-24-2013
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Advanced thyroid cancer responds poorly to most therapies. New therapies and combinations are needed. The aim of this study was to examine both in vitro and in vivo activity of two relatively new histone deacetylase inhibitors (HDACIs), belinostat and panobinostat, and a variety of tyrosine kinase inhibitors (TKIs) against a panel of nine human thyroid cancer cell lines.
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Translation of proteomic biomarkers into FDA approved cancer diagnostics: issues and challenges.
Clin Proteomics
PUBLISHED: 04-23-2013
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Tremendous efforts have been made over the past few decades to discover novel cancer biomarkers for use in clinical practice. However, a striking discrepancy exists between the effort directed toward biomarker discovery and the number of markers that make it into clinical practice. One of the confounding issues in translating a novel discovery into clinical practice is that quite often the scientists working on biomarker discovery have limited knowledge of the analytical, diagnostic, and regulatory requirements for a clinical assay. This review provides an introduction to such considerations with the aim of generating more extensive discussion for study design, assay performance, and regulatory approval in the process of translating new proteomic biomarkers from discovery into cancer diagnostics. We first describe the analytical requirements for a robust clinical biomarker assay, including concepts of precision, trueness, specificity and analytical interference, and carryover. We next introduce the clinical considerations of diagnostic accuracy, receiver operating characteristic analysis, positive and negative predictive values, and clinical utility. We finish the review by describing components of the FDA approval process for protein-based biomarkers, including classification of biomarker assays as medical devices, analytical and clinical performance requirements, and the approval process workflow. While we recognize that the road from biomarker discovery, validation, and regulatory approval to the translation into the clinical setting could be long and difficult, the reward for patients, clinicians and scientists could be rather significant.
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Detection of base excision repair enzyme activity using a luminescent G-quadruplex selective switch-on probe.
Chem. Commun. (Camb.)
PUBLISHED: 04-05-2013
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We report herein a simple and convenient luminescent assay for detection of base excision repair enzyme activity using an Ir(III) complex as a G-quadruplex selective probe. Using uracil-DNA glycosylase (UDG) as a model enzyme, the assay achieved high sensitivity and selectivity for UDG over other tested enzymes. The utility of the assay for screening potential UDG inhibitors was also demonstrated.
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Congenital fibrosis of extraocular muscle type 1A due to KIF21A mutation: first case report from Hong Kong.
Hong Kong Med J
PUBLISHED: 03-29-2013
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With the advancement of ophthalmological genetics, the molecular basis for more and more eye diseases can be elucidated. Congenital fibrosis of extraocular muscle (CFEOM) is an example. It is characterised by a congenital non-progressive restrictive ophthalmoplegia and ptosis. It is an autosomal dominant disease, caused by mutations of the KIF21A gene. With positive family history and typical ophthalmological findings, mutational analysis of KIF21A gene should be performed, not only to confirming the diagnosis, but also to offer a prognosis, for genetic counselling, and the possibility of prenatal diagnosis. Here we report the first KIF21A mutation associated with CFEOM1A in Hong Kong.
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Genomic and functional characterizations of phosphodiesterase subtype 4D in human cancers.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 03-27-2013
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Discovery of cancer genes through interrogation of genomic dosage is one of the major approaches in cancer research. In this study, we report that phosphodiesterase subtype 4D (PDE4D) gene was homozygously deleted in 198 cases of 5,569 primary solid tumors (3.56%), with most being internal microdeletions. Unexpectedly, the microdeletions did not result in loss of their gene products. Screening PDE4D expression in 11 different types of primary tumor samples (n = 165) with immunohistochemistry staining revealed that its protein levels were up-regulated compared with corresponding nontransformed tissues. Importantly, depletion of endogenous PDE4D with three independent shRNAs caused apoptosis and growth inhibition in multiple types of cancer cells, including breast, lung, ovary, endometrium, gastric, and melanoma, which could be rescued by reexpression of PDE4D. We further showed that antitumor events triggered by PDE4D suppression were lineage-dependently associated with Bcl-2 interacting mediator of cell death (BIM) induction and microphthalmia-associated transcription factor (MITF) down-regulation. Furthermore, ectopic expression of the PDE4D short isoform, PDE4D2, enhanced the proliferation of cancer cells both in vitro and in vivo. Moreover, treatment of cancer cells with a unique specific PDE4D inhibitor, 26B, triggered massive cell death and growth retardation. Notably, these antineoplastic effects induced by either shRNAs or small molecule occurred preferentially in cancer cells but not in nonmalignant epithelial cells. These results suggest that although targeted by genomic homozygous microdeletions, PDE4D functions as a tumor-promoting factor and represents a unique targetable enzyme of cancer cells.
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Hepatitis B Management in Vulnerable Populations: Gaps in Disease Monitoring and Opportunities for Improved Care.
Dig. Dis. Sci.
PUBLISHED: 03-22-2013
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Hepatitis B (HBV) is prevalent in certain US populations and regular HBV disease monitoring is critical to reducing associated morbidity and mortality. Adherence to established HBV monitoring guidelines among primary care providers is unknown.
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A highly sensitive G-quadruplex-based luminescent switch-on probe for the detection of polymerase 3-5 proofreading activity.
Methods
PUBLISHED: 03-19-2013
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We report herein a luminescent switch-on label-free G-quadruplex-based assay for the rapid and sensitive detection of polymerase proofreading activity using a novel iridium(III) complex as a G-quadruplex-selective probe. The interaction of the iridium(III) complex with the G-quadruplex motif facilitates the highly sensitive switch-on detection of polymerase proofreading activity. Using T4 DNA polymerase (T4 pol) as a model enzyme, the assay achieved high sensitivity and selectivity for T4 pol over other tested enzymes.
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Critical appraisal: approaches to caries removal: what the clinical evidence says.
J Esthet Restor Dent
PUBLISHED: 03-19-2013
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Every day in the United States, complete caries removal in vital, asymptomatic teeth with deep carious lesions ends in unavoidable exposure of the pulp. As a result, the complexity and cost of treatment increases dramatically and many patients are left with extraction as their only viable option. This review appraises evidence which supports alternative treatments designed to preserve the vitality of the tooth and thus avoid extraction.
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Silibinin synergizes with histone deacetylase and DNA methyltransferase inhibitors in upregulating E-cadherin expression together with inhibition of migration and invasion of human non-small cell lung cancer cells.
J. Pharmacol. Exp. Ther.
PUBLISHED: 03-05-2013
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Aggressive cancers in the epithelial-to-mesenchymal transition (EMT) phase are characterized by loss of cell adhesion, repression of E-cadherin, and increased cell mobility. Non-small cell lung cancer (NSCLC) differs in basal level of E-cadherin; predominantly exhibiting silenced expression due to epigenetic-related modifications. Accordingly, effective treatments are needed to modulate these epigenetic events that in turn can positively regulate E-cadherin levels. Herein, we investigated silibinin, a natural flavonolignan with anticancer efficacy against lung cancer, either alone or in combination with epigenetic therapies to modulate E-cadherin expression in a panel of NSCLC cell lines. Silibinin combined with HDAC inhibitor Trichostatin A [TSA; 7-[4-(dimethylamino)phenyl]-N-hydroxy-4,6-dimethyl-7-oxohepta-2,4-dienamide] or DNMT inhibitor 5-Aza-deoxycytidine (Aza) significantly restored E-cadherin levels in NSCLC cells harboring epigenetically silenced E-cadherin expression. These combination treatments also strongly decreased the invasion/migration of these cells, which further emphasized the biologic significance of E-cadherin restoration. Treatment of NSCLC cells, with basal E-cadherin levels, by silibinin further increased the E-cadherin expression and inhibited their migratory and invasive potential. Additional studies showed that silibinin alone as well as in combination with TSA or Aza downmodulate the expression of Zeb1, which is a major transcriptional repressor of E-cadherin. Overall these findings demonstrate the potential of combinatorial treatments of silibinin with HDAC or DNMT inhibitor to modulate EMT events in NSCLC cell lines, leading to a significant inhibition in their migratory and invasive potentials. These results are highly significant, since loss of E-cadherin and metastatic spread of the disease via EMT is associated with poor prognosis and high mortalities in NSCLC.
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Simultaneous ventral hernia repair in bariatric surgery.
ANZ J Surg
PUBLISHED: 03-03-2013
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BACKGROUND: Obesity is a significant risk factor in abdominal hernia occurrence and recurrence. In patients having bariatric surgery, there are no clear guidelines as to whether repair should be done simultaneously, especially if procedures involve division or resection of part of the gastrointestinal tract. METHODS: A retrospective case series review over a 6-year period to December 2012 from a prospective database was conducted. As per existing practice for bariatric procedures, patients were followed up indefinitely. Short- and long-term outcomes were analysed. RESULTS: Forty-five patients underwent combined laparoscopic bariatric surgery and abdominal wall hernia repair. Of these, 36 had resection procedures (gastric bypass or sleeve gastrectomy) and 9 had non-resection procedures (gastric banding). The mean operative time was 151?min and the mean length of stay was 3 days. Two patients developed post-operative mesh seroma infections. To date, there have been no mesh removals or recurrent hernias. There was no mortality in this series. DISCUSSION: This study demonstrated a low rate of mesh infection (4.44%) at a median follow-up of 13 months, even when a resectional procedure was performed (5.56%). These results suggest the possible viability and reasonable short-/long-term outcomes of simultaneous laparoscopic abdominal wall hernia repair during bariatric surgical procedures, even if the surgery involved division or resection of part of the gastrointestinal tract. This topic is an area of clinical research that warrants further study.
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Analysis of serum protein glycosylation by a differential lectin immunosorbant assay (dLISA).
Clin Proteomics
PUBLISHED: 02-28-2013
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Lectin immunosorbant assays (LISAs) have been widely used for analyzing protein glycosylation. However, the analysis of serum samples by LISAs could suffer from high sample-dependent background noise. The aim of this study is to develop a differential lectin immunosorbant assay (dLISA) with reduced background interferences.
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G-quadruplexes for luminescent sensing and logic gates.
Nucleic Acids Res.
PUBLISHED: 02-23-2013
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G-quadruplexes represent a versatile sensing platform for the construction of label-free molecular detection assays owing to their diverse structures that can be selectively recognized by G-quadruplex-specific luminescent probes. In this Survey and Summary, we highlight recent examples of the application of the label-free strategy for the development of G-quadruplex-based luminescent detection platforms with a view towards the potential application of tetraplex structures in the design of DNA logic gates.
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A highly selective and non-reaction based chemosensor for the detection of Hg2+ ions using a luminescent iridium(III) complex.
PLoS ONE
PUBLISHED: 02-21-2013
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We report herein a novel luminescent iridium(III) complex with two hydrophobic carbon chains as a non-reaction based chemosensor for the detection of Hg(2+) ions in aqueous solution (<0.002% of organic solvent attributed to the probe solution). Upon the addition of Hg(2+) ions, the emission intensity of the complex was significantly enhanced and this change could be monitored by the naked eye under UV irradiation. The iridium(III) complex shows high specificity for Hg(2+) ions over eighteen other cations. The system is capable of detecting micromolar levels of Hg(2+) ions, which is within the range of many chemical systems.
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Phosphorescent imaging of living cells using a cyclometalated iridium (III) complex.
PLoS ONE
PUBLISHED: 02-14-2013
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A cell permeable cyclometalated iridium(III) complex has been developed as a phosphorescent probe for cell imaging. The iridium(III) solvato complex [Ir(phq)2(H2O]2)] preferentially stains the cytoplasm of both live and dead cells with a bright luminescence.
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Luminescent and colorimetric strategies for the label-free DNA-based detection of enzyme activity.
Brief Funct Genomics
PUBLISHED: 02-08-2013
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Enzymes are critically involved in maintaining normal cellular physiology through the catalysis of highly specific and tightly regulated chemical reactions. The inhibition or undesired activation of particular enzymatic functions has been associated with the pathogenesis of a number of diseases. Consequently, the aberrant activity of certain enzymes can be regarded as biomarkers for the diagnosis or monitoring of particular diseases. With rapid technological advances in the field of DNA nanotechnology, oligonucleotides have recently emerged as attractive recognition units for monitoring the activity of enzymes compared with organic small molecules or protein antibodies. In this review article, we present an overview of advantages and versatility of the label-free approach for the fabrication of DNA-based sensing platforms using colorimetric and luminescent molecules as signal transducing units and highlight recent examples of label-free strategies that have been employed for monitoring enzyme activity.
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Clinical experience with a lipid-free, ready-made parenteral nutrition solution in dogs: 70 cases (2006-2012).
J Vet Emerg Crit Care (San Antonio)
PUBLISHED: 01-29-2013
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To review the clinical use of a lipid-free, ready-made amino acid and glucose parenteral nutrition (PN) solution in dogs.
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Label-free luminescent oligonucleotide-based probes.
Chem Soc Rev
PUBLISHED: 01-26-2013
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Breakthrough advances in chemistry and biology over the last two decades have vastly expanded the repertoire of nucleic acid structure and function with potential application in multiple areas of science and technology, including sensing and analytical applications. DNA oligonucleotides represent popular tools for the development of sensing platforms due to their low cost, rich structural polymorphism, and their ability to bind to cognate ligands with sensitivity and specificity rivaling those for protein enzymes and antibodies. In this review, we give an overview of the "label-free" approach that has been a particular focus of our group and others for the construction of luminescent DNA-based sensing platforms. The label-free strategy aims to overcome some of the drawbacks associated with the use of covalently-labeled oligonucleotides prevalent in electrochemical and optical platforms. Label-free DNA-based probes harness the selective interaction between luminescent dyes and functional oligonucleotides that exhibit a "structure-switching" response upon binding to analytes. Based on the numerous examples of label-free luminescent DNA-based probes reported recently, we envisage that this field would continue to thrive and mature in the years to come.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.