bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathologic expression of MHC class II is driven by mitogen‐activated protein kinases
Authors: Martins Isabelle , Deshayes Frederique , Baton Fabrice , Forget Antoine , Ciechomska Iwona , Sylla Khaoussou , Aoudjit Fawzi , Charron Dominique , Al‐Daccak Reem , Alcaide‐Loridan Catherine 
Published: February 2007

AbstractThe class II transactivator (CIITA) is the master regulator of MHC class II molecules (MHC II). In melanoma, the MHC II are constitutively expressed due to an abnormal transcription of CIITA from its promoter III (pIII), and requires the presence of a 1‐kb enhancer located upstream from this latter. Since mitogen‐activated protein kinases (MAPK) have been shown to be activated in most melanomas, we sought to analyze their possible involvement in CIITA expression. Using chemical inhibitors and dominant‐negative constructs of MAPK‐ERK kinase (Mek1) and MAPK‐JNK, we evidenced the inhibition of MHC II and CIITA expression in melanoma cell lines displaying activated MAPK. Transcriptional regulation by MAPK is known to involve the AP‐1 transcription factor family. Sequence analysis revealed an AP‐1‐responsive motif in the enhancer of CIITA pIII at –5954/–5947 from the site of transcription initiation. Its mutagenesis reduced CIITA expression four‐ to fivefold in melanoma cell lines and alleviated the effect of dominant‐negative constructs of the MAPK pathway. Together, our findings demonstrate that MAPK‐ERK and MAPK‐JNK are regulators of CIITA transcription in melanoma, and pinpoint an AP‐1‐responsive site in the CIITA gene pIII. This should have considerable impact on our understanding of the physio‐pathologic expression of MHC II.
HER‐2/neu antigen loss and relapse of mammary carcinoma are actively induced by T cell‐mediated anti‐tumor immune responses
Authors: Kmieciak Maciej , Knutson Keith L. , Dumur Catherine I. , Manjili Masoud H. 
Published: February 2007

AbstractInduction of tumor‐specific immune responses results in the inhibition of tumor development. However, tumors recur because of the tumor immunoediting process that facilitates development of escape mechanisms in tumors. It is not known whether tumor escape is an active process whereby anti‐tumor immune responses induce loss or downregulation of the target antigen in the antigen‐positive clones. To address this question, we used rat neu‐overexpressing mouse mammary carcinoma (MMC) and its relapsed neu antigen‐negative variant (ANV). ANV emerged from MMC under pressure from neu‐specific T cell responses in vivo. We then cloned residual neu antigen‐negative cells from MMC and residual neu antigen‐positive cells from ANV. We found marked differences between these neu‐negative clones and ANV, demonstrating that the residual neu‐negative clones are probably not the origin of ANV. Since initial rejection of MMC was associated with the presence of IFN‐γ‐secreting T cells, we treated MMC with IFN‐γ and showed that IFN‐γ could induce downregulation of neu expression in MMC. This appears to be due to methylation of the neu promoter. Together, these data suggest that neu antigen loss is an active process that occurs in primary tumors due to the neu‐targeted anti‐tumor immune responses.
Generalized multi‐organ autoimmunity in CCR7‐deficient mice
Authors: Davalos‐Misslitz Ana C. M. , Rieckenberg Julia , Willenzon Stefanie , Worbs Tim , Kremmer Elisabeth , Bernhardt Günter , Förster Reinhold 
Published: February 2007

AbstractDevelopment of autoimmunity is a multi‐factorial process involving genetic predisposition as well as environmental and stochastic factors. Although the mechanisms responsible for the initiation of autoimmunity remain only partially understood, several studies have demonstrated that genetic predisposition plays a major role in this process. In the present study, we analyzed the influence of CCR7 signaling in the development of autoimmunity, because this chemokine receptor is essentially involved in the functional organization of thymus architecture. We demonstrate that CCR7‐deficient mice are prone to develop generalized multi‐organ autoimmunity. The autoimmune phenotype of CCR7–/– mice encompasses the presence of lymphocyte infiltrates in several peripheral organs, circulating autoantibodies against a multitude of tissue‐specific antigens and IgG deposition on renal glomeruli. Additionally, CCR7‐deficient mice show increased susceptibility to streptozotocin‐induced diabetes and spontaneously display signs of chronic autoimmune renal disease. Thus, this study identifies CCR7 as a genetic factor involved in the regulation of autoimmunity.
Keggin POMs Modified by Bonding to Multitrack Cu(bipy) Chains through Linearly Arrayed Terminal and Bridging Oxygen Atoms of the M3O13 Triad
Authors: Sha Jingquan , Peng Jun , Liu Hongsheng , Chen Jing , Dong Baoxia , Tian Aixiang , Su Zhongmin 
Published: February 2007

AbstractTwo novel complexes based on the Keggin POMs modified by the Cu(4,4′‐bipy) moiety, {[Cu(4,4′‐bipy)]3[HSiMo12O40]}·1.5H2O (1) and {[Cu(4,4′‐bipy)]4[SiW12O40]}·3H2O (2) (bipy = bipyridine), have been hydrothermally synthesized and characterized by routine physical methods and single‐crystal X‐ray diffraction. Complexes 1 and 2 represent the first examples of fully oxidized Keggin POM anions as pendant polydentate ligands covalently bonded to a multitrack Cu(bipy) polymer chain(s) through linearly arrayed Od···Oc···Od (Od, terminal oxygen; Oc, bridging oxygen) atoms of single M3O13 triad(s). In the crystalline lattice of 1, the 1D chain is constructed from a α‐[SiMo12O40]4– (SiMo12) cluster as a pendant tridentate ligand covalently bonded to three CuI(4,4′‐bipy) subunits, and the neighbouring polymer strands interconnect with the Keggin fragments geared like the teeth of a zipper. In compound 2, the 2D extended layer structure is composed of a α‐[SiW12O40]4– (SiW12) cluster as a pendant hexadentate ligand covalently bonded to four CuI(4,4′‐bipy) subunits and forms a 2D net‐texture structure with a large vacancy (30.9 × 10.6 Å), and the 2D layers are arranged in a parallel staggering fashion to form a 3D framework.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Control of the EOF in CE using polyelectrolytes of different charge densities
Authors: Danger Grégoire , Ramonda Michel , Cottet Hervé 
Published: February 2007

AbstractThe control of the EOF direction and magnitude remains one of the more challenging issues for the optimization of separations in CE. In this work, we investigated the possibility to use variously charged polyanions for a fine‐tuning of the EOF using polyelectrolyte multilayers. For that purpose, polyanions of poly(acrylamide‐co‐2‐acrylamido‐2‐methyl‐1‐propanesulfonate) (PAMAMPS) with different chemical charge rates varying between 3 and 100% were used. These copolymers are statistic hydrophilic copolymers of acrylamide (AM) and 2‐acrylamido‐2‐methyl‐1‐propanesulfonate (AMPS). The study of the influence of the chemical charge rate (AMPS molar proportion in the copolymer) on the electroosmotic mobility (μeo) of a capillary modified by a polyelectrolyte bilayer (polycation/PAMAMPS) revealed that the fine‐tuning of the EOF was possible, at least for cathodic or slightly anodic EOF (μeo from −5×10−5 to +35×10−5 cm2V−1s−1). Electroosmotic mobility values were compared with the free‐draining electrophoretic mobilities of the PAMAMPS constituting the last layer of the capillary coating. The stability of the EOF is discussed in detail on the basis of successive determinations of electroosmotic mobility and migration times. The application to the separation of a model peptide mixture demonstrated the interest (and the simplicity) of this approach for optimizing resolution and analysis time. Experimental resolutions were compared to the theoretical ones that we would obtain on a fused‐silica capillary having the same EOF as the coated capillary.
Large‐scale differential display analysis of T helper cell differentiation
Authors: Ojala Pekka , Virtanen Eveliina , Chen Zhi 
Published: February 2007

AbstractWe have developed a novel large‐scale multicapillary fluorescent differential display (FDD) platform amenable to further automation. The power of the method is demonstrated by the analysis of T helper cell differentiation. Eight RNA samples from wild type, Stat4 knockout and Stat6 knockout mice were analyzed with 16 anchoring primers and 24 arbitrary primers, resulting in 285 294 sample peaks. Visually selected patterns of differential expression suggest two major regulatory mechanisms: activation and Stat4 genotype. A subset of the findings is reproduced in the confirmatory differential display (DD) that included technical and biological replicates. In a small fragment identification pilot study, we identify Ifi27 and Cct8 to be up‐regulated by T cell activation. We present a method for the analysis of electropherogram similarity across large datasets, based on correlation of low‐resolution representations of electrophoretic data. We show how it can be applied to analyze experimental and technical variables. Using this method, we demonstrate the effect of activation and genotype. In addition, agreement of our real experimental data to the theoretical basis of DD, as well as issues in anchoring primer selectivity, are studied.
A wide‐range, low‐cost 150 bp ladder for sizing DNA fragments between 150 and 4500 bp
Authors: Barvish Zeev , Davis Claytus , Gitelman Inna 
Published: February 2007

AbstractAgarose gel electrophoresis, a very routine procedure, requires molecular weight standards; these are usually manufactured from plasmid or viral DNA fragments, or more recently, from PCR products of defined sizes. We describe here the preparation of a molecular weight standard from a completely different DNA source – the uniquely organized genome of the beetle Tenebrio molitor. The standard can be used to accurately size DNAs between 150 and 4500 bp, a useful range of sizes for many agarose gel electrophoresis applications, including separation of PCR products and plasmid cloning targets. In addition, it is easy to prepare, inexpensive, and rivals the best of the commercial ladders.
Determination of xanthohumol in hops (Humulus lupulus L.) by nonaqueous CE
Authors: Kac Javor , Zakrajšek Jure , Mlinarič Aleš , Kreft Samo , Filipič Metka 
Published: February 2007

AbstractXanthohumol (XN) is a prenylated chalcone with antimutagenic and anticancer activity from hops. A nonaqueous reverse polarity capillary electrophoretic method for the determination of XN in hop extract was developed and validated. The optimal parameters were a 64.5 cm long fused‐silica capillary with 50 μm id at 25°C; 30 kV negative voltage (anode at detector side of the capillary); nonaqueous buffer with 75 mM NaOH and 50 mM boric acid in methanol; hydrodynamical injection with 10 mbar for 40 s; and detection at 440 nm. XN, isoxanthohumol (IX), colupulone, adlupulone, and n‐lupulone were well resolved on the electropherogram. The LOD for XN was 0.05 mg/L and RSD for peak area was below 3%. The amount of XN in different samples of hop pellets varied from 0.14 to 0.42%.
Cell cycle‐dependent characterization of single MCF‐7 breast cancer cells by 2‐D CE
Authors: Harwood Melissa M. , Bleecker Joan V. , Rabinovitch Peter S. , Dovichi Norman J. 
Published: February 2007

AbstractThe composition of single MCF‐7 breast cancer cells is characterized using 2‐D CE. Individual MCF‐7 cells were aspirated into a 30 μm inner diameter fused‐silica capillary and lysed by contact with an SDS‐containing buffer. Proteins and other primary amines were fluorescently labeled on‐column using the fluorogenic dye 3‐(2‐furoyl)quinoline‐2‐carboxaldehyde. Labeled components were separated first according to molecular weight using capillary sieving electrophoresis (CSE) and then by MEKC. Analytes were detected in a sheath‐flow cuvette using LIF. The expression profiles for MCF‐7 cellular homogenate and a single MCF‐7 cell are compared. As a proof‐of‐principle investigation, variation in expression was also compared within and between G1 and G2/M cell cycle phases for MCF‐7 cells. Following their treatment with the viable nuclear stain Hoechst 33342, MCF‐7 cells were sorted by flow cytometry on the basis of their ploidy. Sorted cells were then analyzed by 2‐D CE. The degree of variability was >2.5 times larger between cells of different phases than between cells of the same phase. In typical 1 h 2‐D CE separations using MCF‐7 cells, over 100 components are resolved.
Ultrahigh‐pressure dual online solid phase extraction/capillary reverse‐phase liquid chromatography/tandem mass spectrometry (DO‐SPE/cRPLC/MS/MS): A versatile separation platform for high‐throughput and highly sensitive proteomic analyses
Authors: Min Hye‐Ki , Hyung Seok‐Won , Shin Joong‐Won , Nam Hui‐Sun , Ahn Sung‐Hyun , Jung Hee Jung , Lee Sang‐Won 
Published: February 2007

AbstractCapillary RPLC/ESI‐MS (cRPLC/ESI‐MS) is one of the most powerful analytical tools for current proteomic research. The development of cRPLC techniques coupled online to a mass spectrometer has focused on increasing the separation efficiency, detection sensitivity, and throughput. Recently, the use of high‐pressure (over 10 000 psi) LC systems that utilize long, small inner diameter capillary columns has gained much attention for proteomic analyses. In this study, we developed an ultrahigh‐pressure dual online SPE/capillary RPLC (DO‐SPE/cRPLC) system. This LC system employs two online SPE columns and two capillary columns (75 μm inner diameter×1 m length) in a single separation system, and has a maximum operating pressure of 10 000 psi. This DO‐SPE/cRPLC system is capable of providing high‐resolution separation in addition to several other advantageous features, such as high reproducibility in terms of the LC retention time, rapid sample injection, online desalting, online sample enrichment of dilute samples, and increased throughput as a result of essentially removing the column equilibration time between successive experiments. We coupled the DO‐SPE/cRPLC system online to a tandem mass spectrometer to allow high‐throughput proteomic analyses. In this paper, we demonstrate the efficiency of this DO‐SPE/cRPLC/MS/MS system by its use in the analyses of proteomic samples exhibiting different levels of complexity.
Reference strand‐mediated conformation analysis‐based typing of multiple alleles in the rhesus macaque MHC class I Mamu‐A and Mamu‐B loci
Authors: Tanaka‐Takahashi Yumiko , Yasunami Michio , Naruse Taeko , Hinohara Kunihiko , Matano Tetsuro , Mori Kazuyasu , Miyazawa Masaaki , Honda Mitsuo , Yasutomi Yasuhiro , Nagai Yoshiyuki , Kimura Akinori 
Published: February 2007

AbstractThe rhesus macaque exhibits individual differences in susceptibility and resistance to infectious agents such as simian immunodeficiency virus (SIV) under experimental conditions, and these may be genetically determined at least in part by major histocompatibility complex (MHC) class I polymorphism. Although the importance of defining MHC class I polymorphism is well recognized, development of a generic and comprehensive molecular typing method of MHC class I alleles of the rhesus macaque has been hampered because, during the evolution of this species, multiple copies of similar DNA sequences have been generated by duplication events including the coding sequences of Mamu‐A and Mamu‐B loci. We report here a newly developed reference strand‐mediated conformation analysis (RSCA)‐based typing method of multiple Mamu‐A and Mamu‐B cDNAs that allowed us to estimate the number of expressed alleles. This technique detected 1–7 Mamu‐A signals and 2–12 Mamu‐B signals in a single sample, indicating that the number of functional alleles may vary. By comparing the data from the parents with those from the descendants in the breeding colony, several MHC class I haplotypes consisting of variable numbers of functional Mamu‐A and Mamu‐B alleles could be assigned.
Defining shore platform boundaries using airborne laser scan data: a preliminary investigation
Authors: Palamara D. R. , Dickson M. E. , Kennedy D. M. 
Published: February 2007

AbstractAs an initial evaluation of the potential of digital elevation models (DEMs) and geographic information systems (GISs) for geomorphic characterization of rocky shorelines, airborne laser scan (ALS) data have been used to characterize shore platforms around Shag Point, southeastern New Zealand. The platforms have been characterized using field‐based techniques in previously published research, and therefore offer an ideal site for evaluation purposes. The main challenge involved the delineation of the shore platform area in terms of landward and seaward extents. The cliff top and landward edge of the shore platform was readily mapped, whereas the seaward edge of platforms was mapped with lesser precision due to difficulties associated with tidal inundation and the interference of wave action and surface water. In the central region of the study area (∼0·1 km2) higher platform elevations and dense point cloud data enabled the generation of a high‐resolution (1 m) DEM. In analysing the DEM, ALS offered an advantage over the previous field survey in respect of the ability to assess continuous topography in plan‐view. The extent and form of two distinctive erosional surfaces is clearly apparent and was revealed through classifications based on slope and elevation. The spatial continuity of the upper surface implies that, in addition to the role of rock structure described in previous work, sea level and wave exposure may have been important factors in the generation and preservation of platform morphology at Shag Point. Copyright © 2007 John Wiley & Sons, Ltd.
A new technique for non‐destructive field measurement of rock‐surface strength: an application of the Equotip hardness tester to weathering studies
Authors: Aoki Hisashi , Matsukura Yukinori 
Published: February 2007

AbstractTafone‐like depressions have developed on the Aoshima sandstone blocks used for a masonry bridge pier in the coastal spray zone. A thin layer of partial granular disintegration was found on the surface in depressions. To evaluate quantitatively the strength of the thin weathered layer, the hardness was measured at the surface of the sandstone blocks using both an Equotip hardness tester and an L‐type Schmidt hammer. Comparison of the two testing results indicates that the Equotip hardness value is more sensitive in evaluating the strength of a thin layer of weathered surface rock than the Schmidt hardness value. By applying two methods, i.e. both the repeated impact method and the single impact method, the Equotip tester can evaluate the strengths of fresh internal and weathered surficial portions of rocks having a thin weathering layer. Comparison of the two strengths enables evaluation of strength reduction due to weathering. Copyright © 2007 John Wiley & Sons, Ltd.
Biocatalytic aldehyde reduction using tailor‐made whole‐cell catalysts: a novel synthesis of the aroma chemical cinnamyl alcohol
Authors: Chamouleau Francoise , Hagedorn Chad , May Oliver , Gröger Harald 
Published: February 2007

AbstractA biocatalytic method for the synthesis of the aroma chemical cinnamyl alcohol by means of a wholecell‐catalysed reduction of cinnamyl aldehyde has been developed. As a biocatalyst, recombinant whole cells overexpressing an alcohol dehydrogenase from Lactobacillus kefir and a glucose dehydrogenase from Thermoplasma acidophilum have been used in combination with d‐glucose as co‐substrate. The reduction process proceeds with a conversion of 98%, even at a high substrate input of 166 g/l cinnamyl aldehyde, and gives a yield of 77% of the desired product, cinnamyl alcohol. In addition to high product concentrations, further advantages of this approach are the use of a low‐cost whole‐cell catalyst, the high purity of the product, as well as the fact that there is no need for the addition of external co‐factor in the biotransformation step. Copyright © 2007 John Wiley & Sons, Ltd.
Essential oil composition of the flowerheads of Chrysanthemum coronarium L. from Greece
Authors: Basta Andriani , Pavlović Milica , Couladis Maria , Tzakou Olga 
Published: February 2007

AbstractThe essential oils of the flowerheads (capitula) of Chrysanthemum coronarium (Compositae), collected in two different locations in Greece, were obtained by hydrodistillation and analysed by GC–MS. Fifty‐six constituents were identified, of which oxygenated monoterpenes made the highest contribution. The major constituents in sample A were trans‐chrysanthenyl acetate (13.2%), trans‐chrysanthenyl isovalerate (10.2%) and cis‐chrysanthenyl acetate (9.9%), while those of sample B were camphor (15.7%), cis‐chrysanthenyl acetate (9.1%) and trans‐chrysanthenyl acetate (7.8%). Copyright © 2007 John Wiley & Sons, Ltd.
Exocytosis of ATP from astrocyte progenitors modulates spontaneous Ca2+ oscillations and cell migration
Authors: Striedinger Katharine , Meda Paolo , Scemes Eliana 
Published: February 2007

AbstractIn the mature central nervous system (CNS) regulated secretion of ATP from astrocytes is thought to play a significant role in cell signaling. Whether such a mechanism is also operative in the developing nervous system and, if so, during which stage of development, has not been investigated. We have tackled this question using cells derived from reconstituted neurospheres, as well as brain explants of embryonic mice. Here, we show that in both models of neural cell development, astrocyte progenitors are competent for the regulated secretion of ATP‐containing vesicles. We further document that this secretion is dependent on cytosolic Ca2+ and the v‐SNARE system, and takes place by exocytosis. Interference with ATP secretion alters spontaneous Ca2+ oscillations and migration of neural progenitors. These data indicate that astrocyte progenitors acquire early in development the competence for regulated secretion of ATP, and that this event is implicated in the regulation of at least two cell functions, which are critical for the proper morphogenesis and functional maturation of the CNS. © 2007 Wiley‐Liss, Inc.