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Fluoro
Selected AbstractsHighly Enantioselective Synthesis of No-Carrier-Added 6-[18F]Fluoro- L -dopa by Chiral Phase-Transfer AlkylationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2004Christian Lemaire Abstract [18F]Fluoro- L -dopa, an important radiopharmaceutical for positron emission tomography (PET), has been synthesized using a phase-transfer alkylation reaction. A chiral quaternary ammonium salt derived from a Cinchona alkaloid served as phase-transfer catalyst for the enantioselective alkylation of a glycine derivative. The active methylene group of this Schiff-base substrate was deprotonated with cesium hydroxide and rapidly alkylated by the 2-[18F]fluoro-4,5-dimethoxybenzyl halide (X = Br, I). The reaction proceeded with high yield (> 90%) at 0 °C or room temperature in various solvents such as toluene or dichloromethane. Preparation of the [18F]alkylating agent on a solid support was developed. After labelling, the labeled [18F]fluoroveratraldehyde was trapped on a tC18 cartridge and then converted on the cartridge into the corresponding benzyl halide derivatives by addition of aqueous sodium borohydride and gaseous hydrobromic or -iodic acid. Hydrolysis and purification by preparative HPLC made 6-[18F]fluoro- L -dopa ready for human injection in a 25,30% decay-corrected radiochemical yield in a synthesis time of 100 min. The product was found to be chemically, radiochemically and enantiomerically pure (ee > 95%). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Highly Efficient and Stereoselective Julia,Kocienski Protocol for the Synthesis of ,-Fluoro-,,,-unsaturated Esters and Weinreb Amides Employing 3,5-Bis(trifluoromethyl)phenyl (BTFP) SulfonesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2008Diego Abstract ,-Fluoroacetates 3 and Weinreb amide 4, bearing a ,-[3,5-bis(trifluoromethyl)phenyl]sulfonyl (BTFP-sulfonyl) group at the ,-position, are employed in the highly stereoselective synthesis of ,-fluoro-,,,-unsaturated alkenoates and Weinreb amides, respectively. Aromatic and aliphatic aldehydes are condensed under extremely mild and simple reaction conditions using potassium carbonate in dimethylformamide at room temperature under solid-liquid phase-transfer catalysis conditions in good yields and high Z -diastereoselectivities, specially in the case of the fluorinated Weinreb amides. A detailed computational mechanistic study suggests a final non-concerted elimination of sulfur dioxide and 3,5-bis(trifluoromethyl)phenoxide and explains the observed high stereoselectivities for the reaction on the basis of thermodynamic and kinetic considerations. [source] Synthesis of Fluorinated Chitin Derivatives via Enzymatic PolymerizationMACROMOLECULAR BIOSCIENCE, Issue 10 2006Akira Makino Abstract Summary: Synthesis of fluorinated chitin derivatives has been achieved using chitinase from Bacillus sp. as a catalyst. 6,-Fluoro- (1a), 6-fluoro- (1b) and 6,6,-difluoro- (1c) chitobiose oxazoline derivatives were newly prepared as TSAS monomers for chitinase. Ring-opening polyaddition of these monomers proceeded effectively at pH 8.0,9.0 and 30,40,°C, giving rise to alternatingly 6-fluorinated chitin derivatives (2a and 2b) from 1a and 1b, and fully 6-fluorinated chitin derivative (2c) from 1c under total control of regioselectivity and stereochemistry. XRD measurements revealed that polysaccharides 2a and 2b had crystalline structures similar to that of , -chitin. [source] ChemInform Abstract: A Convenient Method for the Synthesis of (Z)-,-Fluoroacrylates: Lewis Base-Catalyzed Carbonyl Fluoroolefination Using Fluoro(trimethylsilyl)ketene Ethyl Trimethylsilyl Acetal.CHEMINFORM, Issue 1 2009Makoto Michida Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Highly Efficient and Stereoselective Julia,Kocienski Protocol for the Synthesis of ,-Fluoro-,,,-unsaturated Esters and Weinreb Amides Employing 3,5-Bis(trifluoromethyl)phenyl (BTFP) Sulfones.CHEMINFORM, Issue 50 2008Diego A. Alonso Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] New Functionalized, Differently Fluorinated Building-Blocks via Michael Addition to ,-Fluoro-,-nitroalkenes.CHEMINFORM, Issue 43 2006Marco Molteni Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis of ,-Fluoro-,-amino Acids by Claisen Rearrangement.CHEMINFORM, Issue 40 2005Frank Tranel Abstract For Abstract see ChemInform Abstract in Full Text. [source] Syntheses of ,-Fluoro-,,,-Unsaturated Thioamides and Thiazolines from a Fluorophosphonodithioacetate.CHEMINFORM, Issue 46 2004Emmanuel Pfund Abstract For Abstract see ChemInform Abstract in Full Text. [source] (C4N2H12) [FeII0.86FeIII1.14 (HPO3)1.39 (HPO4)0.47 (PO4)0.14F3]: A Fluoro,Phosphite,Hydrogenphosphate,Phosphate Iron(II,III) Mixed-Valence Organically Templated Compound.CHEMINFORM, Issue 17 2004Sergio Fernandez-Armas Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Novel One-Pot Conversion of Aldehydes to (E)-,-Fluoro-,-trifluoromethylallylic Alcohols.CHEMINFORM, Issue 20 2003Yanchang Shen No abstract is available for this article. [source] ChemInform Abstract: Highly Efficient and Stereoselective Route to threo- and erythro-,-Allylated ,-Fluoro-,-hydroxy Esters via Radical Allylation Reaction.CHEMINFORM, Issue 33 2002Takashi Ishihara Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Highly Stereoselective Radical Reduction of ,-Bromo-,-fluoro-,-hydroxy Esters with Tributyltin Hydride Leading to threo-,Fluoro-,-hydroxy Esters.CHEMINFORM, Issue 27 2002Kazuhide Mima Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Electrophilic Fluorination Mediated by Cinchona Alkaloids: Highly Enantioselective Synthesis of ,-Fluoro-,-phenylglycine Derivatives.CHEMINFORM, Issue 14 2002Barbara Mohar Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: A New "One-Pot" Conversion of Trifluoroacetic Ester to ,-Fluoro-,-trifluoromethyl-,-alkoxy-vinylphosphonates.CHEMINFORM, Issue 28 2001Yanchang Shen Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Pd-Catalyzed Asymmetric Hydrogenation of ,-Fluorinated Iminoesters in Fluorinated Alcohol: A New and Catalytic Enantioselective Synthesis of Fluoro ,-Amino Acid Derivatives.CHEMINFORM, Issue 20 2001Hajime Abe Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] XNA, (xylo Nucleic Acid): A Summary and New DerivativesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 11 2005B. Ravindra Babu Abstract Fully modified homopyrimidine 2'-deoxy- xylo nucleic acid (dXNA) form triple helixes with complementary DNA/RNA with thermal stabilities comparable to those of the corresponding DNA:DNA and DNA:RNA duplexes. However, a single or few insertions of dXNA monomers in a DNA strand significantly lower duplex stabilities. The dXNA monomers are known to adopt predominantly an N -type furanose conformation in solution. With a desire to increase the binding affinity, seven sugar-modified XNA monomers (H, F, N, M, K, P and Q) have been synthesised and their effect on hybridization towards DNA and RNA complements studied. The introduction of 2'-fluoro and 2'-hydroxy substituents was expected to induce conformational restriction towards C3'- endo -type furanose conformation of monomer F derived from 1-(2'-deoxy-2'-fluoro-,- D -xylofuranosyl)thymine and monomer H derived from 1-(,- D -xylofuranosyl)thymine. The presence of functionalites facing the minor groove as in 1-(2'-amino-2'-deoxy-2'- N,4'- C -methylene-,- D -xylofuranosyl)thymine (monomer N), 1-[4- C -(N -methylpiperazinyl)methyl-,- D -xylofuranosyl]thymine (monomer P), 1-(4- C -piperazinylmethyl-,- D -xylofuranosyl)thymine (monomer Q), 1-(4- C -hydroxymethyl-,- D -xylofuranosyl)thymine (monomer M) and 9-(4- C -hydroxymethyl-,- D -xylofuranosyl)adenine (monomer K) was studied, with monomer N being locked in an N -type furanose conformation. Besides, an efficient synthesis of known xylo -LNA phosphoramidite 19, required for the incorporation of 1-(2'- O,4'- C -methylene-,- D -xylofuranosyl)thymine (monomer L) is described. For comparison, hydridization data of various XNAs reported in the literature are included in the discussion section. The thermal denaturation studies show that XNAs containing conformationally locked monomers (N and L) display improved binding affinity, and that partially modified DNA/XNA chimera, or fully modified XNA display preferential hybridization towards RNA complements. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Highly Enantioselective Synthesis of No-Carrier-Added 6-[18F]Fluoro- L -dopa by Chiral Phase-Transfer AlkylationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2004Christian Lemaire Abstract [18F]Fluoro- L -dopa, an important radiopharmaceutical for positron emission tomography (PET), has been synthesized using a phase-transfer alkylation reaction. A chiral quaternary ammonium salt derived from a Cinchona alkaloid served as phase-transfer catalyst for the enantioselective alkylation of a glycine derivative. The active methylene group of this Schiff-base substrate was deprotonated with cesium hydroxide and rapidly alkylated by the 2-[18F]fluoro-4,5-dimethoxybenzyl halide (X = Br, I). The reaction proceeded with high yield (> 90%) at 0 °C or room temperature in various solvents such as toluene or dichloromethane. Preparation of the [18F]alkylating agent on a solid support was developed. After labelling, the labeled [18F]fluoroveratraldehyde was trapped on a tC18 cartridge and then converted on the cartridge into the corresponding benzyl halide derivatives by addition of aqueous sodium borohydride and gaseous hydrobromic or -iodic acid. Hydrolysis and purification by preparative HPLC made 6-[18F]fluoro- L -dopa ready for human injection in a 25,30% decay-corrected radiochemical yield in a synthesis time of 100 min. The product was found to be chemically, radiochemically and enantiomerically pure (ee > 95%). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis of ,-fluoro-,-trifluoromethyl alka-2,4-dienesHETEROATOM CHEMISTRY, Issue 3 2007Yanchang Shen The palladium/copper(I) iodide cocatalyzed coupling reaction of (Z)-,-fluoro-,-trifluoromethylstannanes (1) with vinyl iodides (2) has been explored giving substituted ,-fluoro-,-trifluoromethyl dienes (3) in 33,95% yields. In studies we have conducted so far, a larger number of the configurations of the products remained unchanged (cases 3a, 3e,h), though in several cases (cases 3b,d) two configurations of the products were obtained. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:208,211, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20284 [source] Regioselective C-2 or C-5 Direct Arylation of Pyrroles with Aryl Bromides using a Ligand-Free Palladium CatalystADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Julien Roger Abstract A simple and atom-economical procedure for the regioselective C-2 or C-5 arylation of pyrroles via a CH bond activation is reported. Only 0.5,0.01 mol% of commercially available and air-stable ligand-free palladium(II) acetate [Pd(OAc)2] was employed as the catalyst. The presence of electron-withdrawing substituents such as formyl, acetyl or ester at the C-2 position of the pyrrole is tolerated. This environmentally attractive procedure has also been found to be tolerant to a very wide variety of functional groups on the aryl bromides such as formyl, acetyl, propionyl, ester, nitrile, nitro, fluoro, methoxy, amino or trifluoromethyl. [source] Selective Preparation of Diamondoid Fluorides[1]ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2009Hartmut Schwertfeger Abstract The selective fluorination of diamantane, triamantane, [121]tetramantane, and [1(2,3)4]pentamantane bromides and alcohols was achieved by using the fluorinating agents silver fluoride (AgF) and diethylaminosulfur trifluoride (DAST). Various mono-, di-, tri- and even tetrafluorinated diamondoid derivatives were prepared and characterized. We were also able to prepare the amino fluoro and the fluoro alcohol derivatives of diamantane from the corresponding monoprotected diamondoid diols. These reactions can be carried out in a highly selective manner and proceed without isomerizations. The fluorinated, unequally disubstituted derivatives are valuable compounds for the exploration of electronic, pharmacological, and material properties of functionalized diamondoids. [source] Palladium-Catalyzed Direct C-4 Arylation of 2,5-Disubstituted Furans with Aryl BromidesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2008Aditya Abstract A simple and atom-economic procedure for the selective C-4 arylation of 2,5-disubstituted furans via CH bond activation using electron-deficient aryl bromides is reported. Only 0.5 mol% of the commercially available dimeric (allene)palladium chloride, [Pd(C3H5)Cl]2, was employed as catalyst. This environmentally attractive procedure has been found to be tolerant to a variety of functional groups on the aryl bromide such as carbonyl, nitrile, nitro, fluoro, ester or trifluoromethyl. [source] Highly Efficient and Stereoselective Julia,Kocienski Protocol for the Synthesis of ,-Fluoro-,,,-unsaturated Esters and Weinreb Amides Employing 3,5-Bis(trifluoromethyl)phenyl (BTFP) SulfonesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2008Diego Abstract ,-Fluoroacetates 3 and Weinreb amide 4, bearing a ,-[3,5-bis(trifluoromethyl)phenyl]sulfonyl (BTFP-sulfonyl) group at the ,-position, are employed in the highly stereoselective synthesis of ,-fluoro-,,,-unsaturated alkenoates and Weinreb amides, respectively. Aromatic and aliphatic aldehydes are condensed under extremely mild and simple reaction conditions using potassium carbonate in dimethylformamide at room temperature under solid-liquid phase-transfer catalysis conditions in good yields and high Z -diastereoselectivities, specially in the case of the fluorinated Weinreb amides. A detailed computational mechanistic study suggests a final non-concerted elimination of sulfur dioxide and 3,5-bis(trifluoromethyl)phenoxide and explains the observed high stereoselectivities for the reaction on the basis of thermodynamic and kinetic considerations. [source] Trends of the bonding effect on the performance of DFT methods in electric properties calculations: A pattern recognition and metric space approach on some XY2 (X = O, S and Y = H, O, F, S, Cl) moleculesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 2 2010Christos Christodouleas Abstract A test set of 10 molecules (open and ring forms of ozone and sulfur dioxide as well as water and hydrogen sulfide and their respective fluoro- and chloro-substituted analogs) of specific atmospheric interest has been formed as to assess the performance of various density functional theory methods in (hyper)polarizability calculations against well-established ab initio methods. The choice of these molecules was further based on (i) the profound change in the physics between isomeric systems, e.g., open (C2v) and ring (D3h) forms of ozone, (ii) the relation between isomeric forms, e.g., open and ring form of sulfur dioxide (both of C2v symmetry), and (iii) the effect of the substitution, e.g., in fluoro- and chloro-substituted water analogs. The analysis is aided by arguments chosen from the information theory, graph theory, and pattern recognition fields of Mathematics: In brief, a multidimensional space is formed by the methods which are playing the role of vectors with the independent components of the electric properties to act as the coordinates of these vectors, hence the relation between different vectors (e.g., methods) can be quantified by a proximity measure. Results are in agreement with previous studies revealing the acceptable and consistent behavior of the mPW1PW91, B3P86, and PBE0 methods. It is worth noting the remarkable good performance of the double hybrid functionals (namely: B2PLYP and mPW2PLYP) which are for the first time used in calculations of electric response properties. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010 [source] Trifluoromethanesulfonic acid, an alternative solvent medium for the direct electrophilic fluorination of DOPA: new syntheses of 6-[18F]fluoro- L -DOPA and 6-[18F]fluoro- D -DOPAJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 14 2007Babak Behnam Azad Abstract Previous work from this laboratory has shown that the direct fluorination of 3, 4-dihydroxy-phenyl- L -alanine (L -DOPA) in anhydrous HF (aHF) or BF3/HF with F2 is an efficient method for the synthesis of 6-fluoro- L -DOPA. Since then, 18F-labeled 6-fluoro- L -DOPA ([18F]6-fluoro- L -DOPA) has been used to study presynaptic dopaminergic function in the human brain and to monitor gastrointestinal carcinoid tumors. This work demonstrates that the reactivity and selectivity of F2 toward L -DOPA in CF3SO3H is comparable with that in aHF. This new synthetic procedure has led to the production of [18F]fluoro- L -DOPA and [18F]fluoro-D-DOPA isomers in 17±2% radiochemical yields (decay corrected with respect to [18F]F2). The 2- and 6-FDOPA isomers were separated by HPLC and subsequently characterized by 19F NMR spectroscopy. The corresponding [18F]-FDOPA enantiomers have been obtained in clinically useful quantities by a synthetic approach that avoids the use of aHF. Copyright © 2007 John Wiley & Sons, Ltd. [source] Utility of 1,3,4,6-tetra- O -acetyl-2-deoxy-2-[18F]fluoro-glucopyranoside for no-carrier-added 18F-glycosylation of amino acidsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 10 2005Simone Maschauer Abstract A radiochemical method for the 18F-glycosylation of amino acid side chains was developed starting from peracetylated 2-deoxy-2-[18F]fluoroglucopyranoside (TA-[18F]FDG). O -(2-deoxy-2-[18F]fluoro- D -glucopyranosyl)- L -serine and the corresponding threonyl compound were obtained in a radiochemical yield of 25% and 12% (related to [18F]fluoride), respectively, after Zemplén deprotection within a total reaction time of 90 min. The anomeric configuration of the corresponding 19F-substituted compounds revealed preferential , -stereoselectivity. The 18F-glycosylation method using TA-[18F]FDG is compatible with the short half-life of fluorine-18 and combines glycosylation and 18F-labelling of a target compound within a single reaction step. TA-[18F]FDG is a promising 18F-labelled prosthetic group and could be adapted to 18F-labelling of bioactive peptides to study their pharmacokinetics using positron emission tomography (PET). Copyright © 2005 John Wiley & Sons, Ltd. [source] Convenient methods for the synthesis of d4, d2 and d6 isotopomers of 4-(4-fluorobenzyl)piperidineJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 6 2005Ágnes Proszenyák Abstract Pure 4-(4-fluoro-[2,3,5,6- 2H4]benzyl)piperidine was prepared via the Grignard reaction of 4-fluoro-[2,3,5,6- 2H4]bromobenzene and pyridine-4-aldehyde followed by consecutive deoxygenation and heteroatomic ring saturation in the presence of palladium on carbon catalyst. An improved method for the catalytic H/D exchange in benzylic positions of 4-(4-fluorobenzyl)piperidine and its d4 derivative has also been described. Copyright © 2005 John Wiley & Sons, Ltd. [source] Synthesis and preliminary in vivo evaluation of 4-[18F]fluoro- N -{2-[4-(6-trifluoromethylpyridin-2-yl)piperazin-1-yl]ethyl}benzamide, a potential PET radioligand for the 5-HT1A receptorJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2004M. Vandecapelle Abstract 4-Fluoro- N -{2-[4-(6-trifluoromethylpyridin-2-yl)piperazin-1-yl]ethyl}benzamide is a full 5-HT1A agonist with high affinity (pKi=9.3), selectivity and a c log P of 3.045. The corresponding PET radioligand 4-[18F]fluoro- N -{2-[4-(6-trifluoromethylpyridin-2-yl)piperazin-1-yl]ethyl}benzamide was synthesized by nucleophilic aromatic substitution on the nitro precursor. The fluorinating agent K[18F]F/Kryptofix 2.2.2 was both dried (9 min, 700 W) and incorporated in the precursor (5 min, 700 W) using a commercially available microwave oven. In a total synthesis time of 60 min, an overall radiochemical yield of 18% (SD=5, n=7, EOS) was obtained. Radiochemical purity was always higher than 99% and specific activity always higher than 81.4 GBq/µmol (2.2 Ci/µmol). Initial brain uptake in mice was 2.19% ID (5.47% ID/g, 2 min) but decreased rapidly (0.17% ID, 0.45% ID/g (60 min)). During the first 20 min p.i., radioactivity concentration of the brain was significantly higher than that of blood demonstrating good brain entry of the tracer. Copyright © 2004 John Wiley & Sons, Ltd. [source] Glioma cells under hypoxic conditions block the brain microvascular endothelial cell death induced by serum starvationJOURNAL OF NEUROCHEMISTRY, Issue 1 2005Yoshifumi Ueda Abstract Angiogenesis is one of essential components for the growth of neoplasms, including malignant gliomas. However, tumor vascularization is often poorly organized and marginally functional due to tumor strucutural abnormalities, inducing regional or temporal hypoxic conditions and nutritional shortages in tumor tissues. We investigated how during angiogenesis migrating endothelial cells survive in these hypoxic and reduced nutritional conditions. Human brain microvascular endothelial cells (HBMECs) underwent apoptosis and necrosis after serum withdrawal. This endothelial cell death was blocked by recombinant VEGF protein or the culture medium of U251 glioma cells exposed to hypoxia (H-CM). Hypoxic treatment increased vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNF-,) expression in U251 glioma cells. H-CM activated nuclear factor-,B (NF,B) protein and increased the gene expression of antiapoptotic factors including Bcl-2, Bcl-XL, survivin and X-chromosome-linked inhibitor of apoptosis protein (XIAP) in endothelial cells. The survival activity of H-CM for endothelial cells was abolished by two kinds of VEGF inhibitors {Cyclopeptidic VEGF inhibitor and a VEGF receptor tyrosine kinase inhibitor (4-[(4,-chloro-2,-fluoro) phenylamino]-6, 7-dimethoxyquinazoline)} or NF,B inhibitors (ALLN and BAY 11,7082). These VEGF inhibitors did not block the activation of NF,B induced by H-CM in endothelial cells. On the contrary, TNF-, antagonist WP9QY enhanced the survival activity of H-CM for endothelial cells and blocked NF,B activation induced by H-CM under serum-starved conditions. Taken together, our data suggest that both the secretion of VEGF from glioma cells and activation of NF,B in endothelial cells induced by TNF-, are necessary for endothelial cell survival as they increase the expression of antiapoptotic genes in endothelial cells under conditions of serum starvation. These pathways may be one of the mechanisms by which angiogenesis is maintained in glioma tissues. [source] Early detection of bone infection and differentiation from post-surgical inflammation using 2-deoxy-2-[18F]-fluoro- D -glucose positron emission tomography (FDG-PET) in an animal modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2005Laurie Jones-Jackson Abstract Diagnosing bone infection in the context of post-surgical inflammation is problematic since many of the early signs of infection are similar to normal post-surgical changes. We used a rabbit osteomyelitis model to evaluate the use of 2-deoxy-2-[18F]-fluoro- D -glucose positron emission tomography (FDG-PET) as a means of detecting post-operative infection in the context of post-surgical inflammation. Comparisons were made between infected and non-infected rabbits in which infection with Staphylococcus aureus was initiated at the time of surgery. Weekly PET scans were obtained 30 and 60 min after the introduction of FDG and analyzed based on standardized uptake values (SUV) at the surgical site and visual assessment of the presence or absence of infection. Concurrent X-rays were taken immediately prior to scanning. At 4 weeks post-operatively, animals were sacrificed for histologic and bacteriologic confirmation of infection. Uptake of FDG was evident in the bone of all rabbits on day 1 post-surgery, however, SUV comparisons from the surgical site could not be used to distinguish between the infected and uninfected groups until day 15. Visual analysis of FDG-PET scans revealed a significant difference (p < 0.01) between the infected and uninfected groups as early as day 8. This was due in part to the ability to visualize regional lymph nodes by FDG-PET.© 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Preparation of anti-danofloxacin antibody and development of an indirect competitive enzyme-linked immunosorbent assay for detection of danofloxacin residue in chicken liverJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2009Zhongqiu Liu Abstract BACKGROUND: Danofloxacin is used widely as both a clinical medicine for humans and a veterinary drug in animal husbandry. In this study a polyclonal anti-danofloxacin antibody was prepared for the first time and a simple and rapid indirect competitive enzyme-linked immunosorbent assay (cELISA) method based on the antibody was developed to monitor danofloxacin residue in chicken liver. RESULTS: The prepared antibody showed high sensitivity, with an IC50 value of 2.0 ng mL,1 towards danofloxacin, and good specificity, with significant cross-reactivity only towards pefloxacin (22%) and fleroxacin (21%) among commonly used (fluoro)quinolones evaluated in the study. The developed cELISA test kit had a detection limit of 0.8 ng mL,1, and satisfactory results were obtained when it was applied to chicken liver spiked with various levels of danofloxacin. The cELISA test kit was also used to detect danofloxacin in chicken liver samples purchased from a local food market, and the results were confirmed by liquid chromatography/mass spectrometry. CONCLUSION: The anti-danofloxacin antibody prepared in this study exhibits excellent quality, with high sensitivity and good specificity. The cELISA test kit based on the antibody has a very low detection limit and is suitable for use as an efficient screening method to detect danofloxacin residue in foods and food products. Copyright © 2009 Society of Chemical Industry [source] | ||||||||||||||||