bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alteration of monocytic cell oxidative burst caused by methacrylic monomers present in dental materials: a chemiluminescence study
Authors: Nocca Giuseppina , Sole Pasquale De , Gambarini Gianluca , Palma Francesco De , Parziale Vito , Giardina Bruno , Lupi Alessandro 
Published: April 2006

AbstractMethacrylates are present in dental composite resins used in clinical practice. Methacrylates are photo‐polymerized, but this reaction is never complete, so release of uncured monomers in the periapical tissues and in biological fluids may happen and, potentially, alter the repair of pulpal and of periapical lesions by interfering with local phagocytes. The aim of this study was the evaluation of the functional activity of the monocyte–macrophage system after incubation with methacrylic monomers. The oxidative burst of two cellular systems was analysed using the chemiluminescence technique. Data were collected and statistically analysed. Monomers were found to reduce the in vitro oxidative burst of phagocytes independently from their cytotoxicity. These findings demand further evaluation of the effects of oxidative burst alteration in monocyte–macrophage function and may prompt the inclusion of the described chemiluminescence test in biocompatibility preliminary studies of dental materials. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of iodide using flow injection with acidic potassium permanganate chemiluminescence detection
Authors: Yaqoob Mohammad , Atiq‐ur‐Rehman  , Waseem Amir , Nabi Abdul 
Published: April 2006

AbstractA simple and rapid flow‐injection method is described for the determination of iodide, based on potassium permanganate chemiluminescence detection via oxidation of formaldehyde in aqueous hydrochloric acid. The calibration graph was linear over the range 1.0–12 × 10−6 mol/L (r2 = 0.9955) with relative standard deviations (n = 4) in the range 1.0–3.5%. The detection limit (3σ) was 1.0 × 10−7 mol/L, with sample throughput of 120/h. The effect of interfering cations [Ca(II), Mg(II), Ni(II), Fe(II), Fe(III) and Pb(II)] and anions (Cl−, SO42−, PO43−, NO3−, NO2−, F− and SO32−) were studied. The method was applied to iodized salt samples and the results obtained in the range 0.03 ± 0.005–0.10 ± 0.006 mg I/g were in reasonable agreement with the amount labelled. The method was statistically compared with the results obtained by titration; no significant disagreement at 95% confidence was observed. Copyright © 2006 John Wiley & Sons, Ltd.
Ruthenium Complexes of Thiocinnamaldehydes: Synthesis, Structure, and [4+2]‐Cycloaddition Reactions
Authors: Schenk Wolfdieter A. , Beucke Thomas , Burzlaff Nicolai , Klüglein Matthias , Stemmler Marco 
Published: April 2006

AbstractRuthenium hydrogensulfido complexes [CpRu(PP)(SH)] ((PP)Ph2PCH2PPh2 (dppm), Ph2PC2H4PPh2 (dppe)) were obtained from the corresponding chloro complexes by Cl/SH exchange. Condensation with a range of cinnamaldehydes gave thiocinnamaldehyde complexes [CpRu(PP)(SCHCR2CHR1)]PF6 (R1=C6H4X, R2=H, Me, X=H, OMe, NMe2, Cl, NO2) as highly‐colored crystalline compounds. The thiocinnamaldehyde complexes undergo [4+2]‐cycloaddition reactions with vinyl ethers CH2CHOR3 (R3=Et, Bu) and styrenes H2CCHC6H4Y (Y=H, Me, OMe, Cl, Br, NO2) to give complexes of 2,4,5‐trisubstituted 3,4‐dihydro‐2H‐thiopyrans as mixtures of two diastereoisomers. The rate of addition of para‐substituted styrenes H2CCHC6H4Y to [CpRu(dppm)(SCHCHCHPh)]PF6 increases in the series Y=NO2, Br, Cl, H, Me, OMe, indicating that the cycloaddition is dominated by the HOMO(dienophile)–LUMO(diene) interaction. The strained dienophiles norbornadiene and norbornene also add, giving ruthenium complexes of 3‐thia‐tricyclo[6.2.1.02,7]undeca‐4,9‐dienes and 3‐thia‐tricyclo[6.2.1.02,7]undec‐4‐enes, respectively. Addition reactions with acrolein, methacrolein, methyl vinyl ketone, acrylic ester, or ethyl propiolate finally yielded ruthenium complexes of 3,4‐disubstituted 3,4‐dihydro‐2H‐thiopyrans and 4H‐thiopyrans, respectively.
Macropodumines A–C: Novel Pentacyclic Alkaloids with an Unusual Skeleton or Zwitterion Moiety from Daphniphyllum macropodum Miq.
Authors: Zhang Wen , Guo Yue‐Wei , Krohn Karsten 
Published: April 2006

AbstractThree novel alkaloids, macropodumines A–C (1–3), were isolated from the stem of Daphniphyllum macropodum Miq. Interestingly, the structure of macropodumine A (1) was characterized as having a fused pentacyclic system including an unusual eleven‐membered macrolactone ring, whereas macropodumine B (2) contains a rare cyclopentadienyl carbanion, which is stabilized as a zwitterion by an internal iminium cation. The structures of these new metabolites were established on the basis of their detailed spectroscopic analysis. In particular, the unique structure of zwitterion 2 was further confirmed by using single‐crystal X‐ray diffraction analysis.
Electron Transfer in Nonpolar Solvents in Fullerodendrimers with Peripheral Ferrocene Units
Authors: Pérez Laura , García‐Martínez Joaquín C. , Díez‐Barra Enrique , Atienzar Pedro , García Hermenegildo , Rodríguez‐López Julián , Langa Fernando 
Published: April 2006

AbstractTwo new fullerodendrimers, with two and four ferrocene units on their periphery, have been synthesized by 1,3‐dipolar cycloaddition reactions between the corresponding azomethine ylides and C60. These new compounds have been studied by using cyclic voltammetry and UV/Vis spectroscopy. Weak intramolecular interactions between the fullerene cage and the ferrocene groups have been found. The photochemical events of both fullerene–ferrocene dendrimers have been probed by means of steady‐state and time‐resolved techniques. The steady‐state emission intensities of the fulleropyrrolidine–ferrocene dendrimers 1 and 2 were found to be quenched relative to the N‐methylfulleropyrrolidine without substituents that was used as a model. The nanosecond transient absorption spectral studies revealed efficient charge separation in both systems, even in toluene. The lifetimes of the (C60).−–(dendron).+ are higher for the second‐generation fullerodendrimer (with four ferrocene units) and they are of the order of tens of nanoseconds in toluene and hundreds of nanoseconds in polar solvents.
Novel method for cell debris removal in the flow cytometric cell cycle analysis using carboxy‐fluorescein diacetate succinimidyl ester
Authors: Terho Perttu , Lassila Olli 
Published: April 2006

AbstractBackground:Cell cycle analysis with flow cytometry using propidium iodide (PI) can be difficult in some cases because of the cell debris. Here, we introduce debris removal using intranuclear protein staining (DRIPS), a novel method for separating intact nuclei and cell debris to different populations using carboxy‐fluorescein diacetate succinimidyl ester (CFSE).Methods:To study the apoptosis‐sensitivity, chicken DT40 B cell lymphoma cell line was γ irradiated. After the irradiation, the cells were incubated up to 8 h and the stages of the cell cycle were followed with flow cytometry.Results:CFSE staining, done simultaneously with PI, stained the cell debris brighter than intact nuclei and could be excluded from the histogram with a simple gating procedure. The method is reliable and reproducible and can be executed within 15 min.Conclusions:DRIPS‐method greatly enhances the analysis of difficult cell cycle samples. © 2006 International Society for Analytical Cytology
Synthesis and Structure of Trialkyltantalum Complexes Stabilized by Aminopyridinato Ligands
Authors: Noor Awal , Kretschmer Winfried , Kempe Rhett 
Published: April 2006

Abstract(4‐Methylpyridin‐2‐yl)(trimethylsilyl)amine (1), (6‐methylpyridin‐2‐yl)(trimethylsilyl)amine (2), and (2,6‐diisopropylphenyl)(pyridin‐2‐yl)amine (3) were deprotonated and used as ligands to synthesize trialkyltantalum complexes. The reaction of 2 equiv. of 1 or 2 with pentabenzyltantalum afforded tribenzyltantalum(V) complexes by toluene elimination. Analogous reaction using 3 failed. Lithiation of 3 followed by the reaction with tribenzyltantalum dichloride gave rise to the corresponding tribenzyl complex. Other alkyltantalum complexes stabilized by this ligand environment can be prepared by treating tantalum pentachloride with 2 equiv. oflithiated 3 to form a bis(aminopyridinato)tantalum trichloride. The reaction of this trichloride with 3 equiv. of alkyllithium compounds like methyllithium affords the corresponding trialkyltantalum complexes. X‐ray diffraction studies of four of the synthesized complexes were carried out. They adopt two different coordination environments, either slightly distorted capped octahedrons (sterically less demanding aminopyridinato ligands) or pentagonal bipyramids (bulkier aminopyridinato ligands). The alkyl species were surprisingly stable at elevated temperatures and no formation of mixed alkyl/alkylidene complexes was observed. Alkyl cation formation and the behaviour of a selection of these compounds in olefin polymerization were explored. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Intramolecular controls for the generation of clinical‐quality SNP genotypes and the assessment of normal heterozygote imbalance
Authors: McKeown Brian , Rowan Paul , Sung Robert , Derbyshire Roger 
Published: April 2006

AbstractWe present an inventive method that generates intramolecular controls for SNP analysis, termed Mirror SNPs. Using the ovine diseases of callipyge and scrapie as examples, we describe the PCR‐driven production of balanced heterozygote copies of the various SNPs implicated in these diseases. In the absence of a callipyge‐positive control DNA, we generated a balanced heterozygote Mirror SNP that represents both the wild‐type and mutant forms of the causal polymorphism. Simultaneous analysis of this artificial Mirror SNP and the Real (target) SNP was used to prove the absence of the mutant form of the nucleotide at the Real SNP position in tested samples. Scrapie susceptibility was assessed using a PCR‐driven system which generated four separate Mirror SNPs, and these enabled the confirmation of an apparent departure from ‘balanced’ heterozygote appearance at Real SNPs tested. Mirror SNP technology is generic and will enable the accurate assessment of rare and medically important SNP variants, more accurate frequency determinations, and the potential assessment of SNPs in ‘mixed template’ samples common in forensic analyses.
Capillary electrophoresis‐mass spectrometry of a new cross‐linker with acrylic functionality
Authors: Simó Carolina , Pérez Paloma , Neusüß Christian , Pelzing Matthias , San Román Julio , Gallardo Alberto , Cifuentes Alejandro 
Published: April 2006

AbstractAnalytical characterization of dimethacrylate‐tyrosine‐lysine‐tyrosine (DMTLT, a new biodegradable acrylic cross‐linker synthesized at our laboratory) is carried out using CE‐MS. DMTLT is a pseudopeptide composed by tyrosine‐lysine‐tyrosine amino acids linked through urea bonds with two methacrylic groups, one at each end of the molecule, making this compound an excellent cross‐linker for polymerization reactions and for obtaining new biodegradable materials. A new CE‐MS method is developed for the characterization of DMTLT and its products of degradation after basic hydrolysis. In order to carry out an exhaustive examination of such degradation products methods based on CE coupled to IT and TOF‐MS are employed. Based on CE‐IT‐MS results and the elemental composition of the degradation products obtained by CE‐TOF‐MS, conclusions on the mechanism and kinetic of hydrolysis of DMTLT are obtained confirming both the usefulness of CE‐MS to characterize new biomaterials and the applicability of DMTLT for preparing new biodegradable polymers. These results are corroborated through the CE‐MS detection of the identified products of degradation in a dimethyl acrylamide polymer cross‐linked with DMTLT.
Isolation, identification and characterisation of starch‐interacting proteins by 2‐D affinity electrophoresis
Authors: Kosar‐Hashemi Behjat , Irwin Jennifer A. , Higgins Jody , Rahman Sadequr , Morell Matthew K. 
Published: April 2006

AbstractA 2‐D affinity electrophoretic technique (2‐DAE) has been used to isolate proteins that interact with various starch components from total barley endosperm extracts. In the first dimension, proteins are separated by native PAGE. The second‐dimensional gel contains polysaccharides such as amylopectin and glycogen. The migration of starch‐interacting proteins in this dimension is determined by their affinity towards a particular polysaccharide and these proteins are therefore spatially separated from the bulk of proteins in the crude extract. Four distinct proteins demonstrate significant affinity for amylopectin and have been identified as starch branching enzyme I (SBEI), starch branching enzyme IIa (SBEIIa), SBEIIb and starch phosphorylase using polyclonal antibodies and zymogram activity analysis. In the case of starch phosphorylase, a protein spot was excised from a 2‐DAE polyacrylamide gel and analysed using Q‐TOF MS/MS, resulting in the alignment of three internal peptide sequences with the known sequence of the wheat plastidic starch phosphorylase isoform. This assignment was confirmed by the determination of the enzyme's function using zymogram analysis. Dissociation constants (Kd) were calculated for the three enzymes at 4°C and values of 0.20, 0.21 and 1.3 g/L were determined for SBEI, SBEIIa and starch phosphorylase, respectively. Starch synthase I could also be resolved from the other proteins in the presence of glycogen and its identity was confirmed using a polyclonal antibody and by activity analysis. The 2‐DAE method described here is simple, though powerful, enabling protein separation from crude extracts on the basis of function.
A simple light‐emitted diode‐induced fluorescence detector using optical fibers and a charged coupled device for direct and indirect capillary electrophoresis methods
Authors: Arráez‐Román David , Fernández‐Sánchez Jorge F. , Cortacero‐Ramírez Sonia , Segura‐Carretero Antonio , Fernández‐Gutiérrez Alberto 
Published: April 2006

AbstractWe constructed a simple fluorescence detector for both direct and indirect CE methods using a blue light‐emitted diode (470 nm) as excitation source, a bifurcated optical fiber as a waveguide, and a CCD camera as a detector. The connection of all the components is fairly easy even for nonexperts and the use of a CCD camera improves the applicability of this detector compared to the others using PMTs because it permits the recording of 2‐D electropherograms or phosphorescence measurements. This detector provides a compact, low cost, and rapid system for the determination of native fluorescence compounds which have high quantum yields by CE with direct fluorescence detection, showing an LOD of 2.6×10−6 M for fluorescein; the determination of fluorescence derivative compounds by CE with direct fluorescence detection, showing an LOD of 1.6×10−7 M for FITC‐labeled 1,6‐diaminohexane; and nonfluorescence compounds by CE with indirect fluorescence detection with an LOD of 2.7×10−6 M for gallic acid.
Sheathless capillary electrophoresis‐mass spectrometry using a pulsed electrospray ionization source
Authors: Chao Bing‐Fong , Chen Chao‐Jung , Li Fu‐An , Her Guor‐Rong 
Published: April 2006

AbstractA sheathless interface has been developed for coupling CE with electrospray IT mass spectrometer. This interface utilized a pulsed ESI source. The use of a pulsed electrospray source allows the use of a sprayer with larger orifice, and thus alleviates the problem of column clogging during conductive coating and CE analysis. A pulsed ESI source operated at 20 Hz and 20% duty cycle was found to produce the optimal signals. For better signals, the maximum ion injection time in the IT mass spectrometer has to be set to a value close to the actual spraying time (10 ms). Using a sprayer with 50 µm od, more stable and enhanced signals were obtained in comparison with continuous CE‐ESI‐MS under the same flow rate (150 nL/min). The utility of this design is demonstrated with the analysis of synthetic drugs by CE‐MS.
The major subtypes of human B‐cell lymphomas lack mutations in BCL‐2 family member BAD
Authors: Schmitz Roland , Thomas Roman K. , Harttrampf Anne C. , Wickenhauser Claudia , Schultze Joachim L. , Hansmann Martin‐Leo , Wolf Jürgen , Küppers Ralf 
Published: April 2006

AbstractMembers of the BCL‐2 gene family are well known for their role in the pathogenesis of B‐cell lymphomas in humans and in mouse models. A recent report that knockout mice deficient for the proapoptotic BCL‐2 family member gene BAD frequently develop B‐cell lymphomas prompted us to analyze a large collection of human B‐cell lymphomas for inactivating mutations in the BAD gene. All 3 exons of the BAD gene were amplified and directly sequenced. The 81 lymphomas analyzed included 16 cases of B‐cell chronic lymphocytic leukemia, 11 mantle‐cell lymphomas, 10 follicular lymphomas, 7 MALT lymphomas, 8 Burkitt's lymphoma cell lines, 3 cell lines of multiple myeloma, 15 cases and 4 cell lines of diffuse large B‐cell lymphoma and 7 Hodgkin's lymphoma lines. No mutations were found in any of the cases. We conclude that mutations in the BAD gene do not play a role in the pathogenesis of the major subtypes of human B‐cell lymphomas. © 2006 Wiley‐Liss, Inc.
Down‐regulation of ASY/Nogo transcription associated with progression of adult T‐cell leukemia/lymphoma
Authors: Shimakage Misuzu , Inoue Nobumasa , Ohshima Kohichi , Kawahara Kunimitsu , Oka Takashi , Yasui Kazuta , Matsumoto Kayoko , Inoue Hirokazu , Watari Akihiro , Higashiyama Shinji , Yutsudo Masuo 
Published: April 2006

AbstractAdult T‐cell leukemia/lymphoma (ATLL) is an aggressive form of human leukemia/lymphoma. Although this disease is initiated by infection with human T‐lymphotropic virus type 1 (HTLV‐1), many HTLV‐1 carriers survive for a long period without aggressive illness, suggesting that other factors may play roles in the progression of ATLL to an aggressive state. However, the mechanism involved in this progression still remains unclear. Previously, we have reported that ASY/Nogo mRNA was markedly down‐regulated in human small‐cell lung carcinomas, whereas it was expressed in normal tissues and other lung carcinomas, such as adenocarcinoma and squamous cell carcinoma. To understand whether or not ASY/Nogo gene is involved in the progression of ATLL, we examined the expression of ASY/Nogo mRNA in smoldering, chronic and aggressive ATLL, and found that the expression level of ASY/Nogo mRNA was markedly reduced in clinically aggressive ATLL. HTLV‐1 Tax expression was not affected by the down‐regulation of ASY/Nogo mRNA. These results indicate that the ASY/Nogo gene may act as a suppressor against ATLL progression, independent of Tax expression. © 2006 Wiley‐Liss, Inc.
Cd8 T‐cell recognition of human 5T4 oncofetal antigen
Authors: Smyth Lucy JC , Elkord Eyad , Taher Taher E.I. , Jiang Hui‐Rong , Burt Deborah J. , Clayton Alison , van Veelen Peter A. , de Ru Arnoud , Ossendorp Ferry , Melief Cornelis J. M. , Drijfhout Jan W. , Dermime Said , Hawkins Robert E. , Stern Peter L. 
Published: April 2006

AbstractThe 5T4 oncofetal antigen is expressed by a wide variety of human carcinomas, including colorectal, ovarian and gastric carcinomas. The restricted expression of 5T4 on tumor tissues as well as its implication in tumor progression and bad prognosis makes 5T4 a promising new candidate for immunotherapy. An MVA vaccine encoding 5T4 antigen has been successfully evaluated in preclinical studies in a murine tumor model. Here, we report the generation of human CD8 T cells specific for the 5T4 antigen by stimulation with autologous monocyte derived DC infected with a replication defective adenovirus encoding the 5T4 cDNA (Ad5T4). Analysis of several donors confirms a repertoire of such CD8 responses. In a parallel approach, incorporating the results of proteasome‐mediated digestion of 5T4 derived 35‐mer peptides and the potential high affinity epitopes predicted by a computer‐based algorithm, we identified 8 putative HLA‐A*0201‐presented CD8 MHC class I epitopes of 5T4 antigen. Two of these generated specific CD8 T cells after restimulation with peptide loaded autologous DC and assay by cytotoxicity and IFNγ ELISPOT. Moreover these particular peptide generated T cells recognized naturally 5T4 positive tumor cells only if they expressed HLA‐A*0201 as judged by IFNγ ELISPOT or ELISA. Also, HLA‐A*0201 CD8 T cells recognized these peptides in a DC‐Ad5T4 polyclonal response. In conclusion, there is a repertoire of CD8 T cell recognition of 5T4 in normal human donors and some candidate HLA‐A*0201 epitopes have been identified. © 2006 Wiley‐Liss, Inc.
Nuclear Ptdlns(3,4,5)P3 signaling: An ongoing story
Authors: Déléris Paul , Gayral Stéphanie , Breton‐Douillon Monique 
Published: April 2006

AbstractPhosphatidylinositol 3,4,5‐trisphosphate (Ptdlns(3,4,5)P3) is linked to a variety of cellular functions, such as growth, cell survival, and differentiation. Ptdlns(3,4,5)P3 is primarily synthesized by class I phosphoinositide 3‐kinases and its hydrolysis by two 3‐phosphoinositide 3‐phosphatases, PTEN and SHIP proteins, leads to the production of two other second messengers, Ptdlns(4,5)P2 and Ptdlns(3,4)P2, respectively. Evidence accumulated over the last years strongly suggest that Ptdlns(3,4,5)P3 is an important component of signaling pathway operating within the nucleus. Moreover, recent advances indicated that nuclear translocation of cell surface receptors could activate nuclear phosphoinositide 3‐kinase suggesting a new mode of signal transduction. The aim of this review is intended to summarize the state of our knowledge on nuclear Ptdlns(3,4,5)P3 and its metabolizing enzymes, and to highlight the emerging roles for intranuclear Ptdlns(3,4,5)P3. J. Cell. Biochem. 98: 469–485, 2006. © 2006 Wiley‐Liss, Inc.
Friedel–Crafts benzylation of aromatics with benzyl alcohols catalyzed by heteropoly acids supported on mesoporous silica
Authors: Kamalakar Gunda , Komura Kenichi , Kubota Yoshihiro , Sugi Yoshihiro 
Published: April 2006

AbstractHeteropoly acids (HPA), such as tungstophosphoric acid (H3PW12O40 · xH2O) (HPW), molybdophosphoric acid (H3PMo12O40 · xH2O) (HPMo) and tungstosilicic acid (H4SiW12O40 · xH2O) (HSiW) were supported on mesoporous silica such as MCM‐41, FSM‐16 and SBA‐15 by the impregnation method to enhance the catalytic activity of these solid acids by their dispersion on the support with high surface area. These supported solid catalysts were used in the benzylation of benzene and substituted aromatics with benzyl alcohol (BnOH). The immobilization enhanced the catalytic performances and HPW supported on MCM‐41 exhibited the best activity for benzylation among the heteropoly acids, although dibenzyl ether (DBE) formation by the dehydration of BnOH also occurred. The mesoporous architecture of the silica enhances the activity of benzylation because of the high dispersion of HPW on the support with high surface area; however, no steric restriction by the pores of mesoporous silica was observed. The catalysts used in the present study retained their catalytic activity for five reaction cycles. The rate of benzylation of substituted benzenes and benzylating agents was influenced by the electronic nature of the substituent. Electron‐donating groups enhanced the rate of reaction; however, electron‐withdrawing groups retard the benzylation. These results show that the reactivity of benzene and benzyl alcohols was retarded by electron‐withdrawing groups. The formation of polybenzylated products was influenced by the reactivity of diphenylmethane products. The benzylation accompanies the DBE formation by the dehydration of BnOH, particularly in the initial stages, because the benzylation of aromatics with BnOH is not as rapid as the dehydration of BnOH. However, direct benzylation of benzene occurs with DBE and DBE participates in the benzylation of benzene via BnOH after its hydrolysis. This is further supported by the effect of water on the benzylation of benzene by DBE, although there is a possibility of direct benzylation of DBE with benzene. Copyright © 2006 Society of Chemical Industry