bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell‐free fetal DNA (SRY locus) concentration in maternal plasma is directly correlated to the time elapsed from the onset of preeclampsia to the collection of blood
Authors: Farina Antonio , Sekizawa Akihiko , Rizzo Nicola , Concu Manuela , Banzola Irina , Carinci Paolo , Simonazzi Giuliana , Okai Takashi 
Published: March 2004

AbstractObjectiveTo determine (1) if fetal DNA (fDNA) in the maternal circulation in women affected by preeclampsia correlates with the time elapsed from the onset of symptoms to the time of blood collection, and (2) if the inclusion of this variable improves the discrimination between affected and unaffected patients by using fDNA distributions.MethodsPlasma were collected from 34 women at 33.7 ± 3.9 weeks' gestation, affected by preeclampsia, and bearing a single male fetus. fDNA was extracted from 1.5‐mL plasma samples, and the SRY and β‐globin gene were analyzed by real‐time quantitative PCR. MoMs (multiple of the control median) were calculated by using a log equation of 102 normal cases. Log MoMs were then plotted against the time elapsed from onset of symptoms to blood collection (expressed in days) by means of a log‐linear regression. Adjusted MoMs were then calculated. ROC curves were used to test the discrimination obtained by using adjusted MoMs.ResultsThe median MoMs of controls and preeclamptic patients were 1.00 ± 1.53 and 2.62 ± 2.70 respectively. By plotting log MoM fDNA against the time elapsed from onset of symptoms to blood collection, we found a significant positive correlation, (p‐value < 0.001, R2 = 0.55, F = 38.97, from 1 to 50 days). The adjusted median fDNA MoM was 2.66 ± 2.50. Areas under the curves, as estimated by ROC curves, were 76.7 for unadjusted and 85.5 for adjusted MoMs respectively (p‐value = 0.02).ConclusionsThe effect of a further covariate showed that (1) fDNA passage from trophoblasts to maternal circulation for unit of time is proportional to the duration of the damage and that (2) increased discrimination can be obtained in comparison to normal subjects. Copyright © 2004 John Wiley & Sons, Ltd.
Structure and properties of an oriented fluorosulfonated/PTFE copolymer
Authors: Gilbert M. , Haworth B. , Myers D. J. B. 
Published: March 2004

AbstractThis polymer is a precursor of Nafion, an ionomer developed for ion‐selective membranes. In this work various stretching procedures were carried out on the precursor, in order to explore the possibilities of enhanced performance. First, the crystallization behavior and properties of the unoriented precursor were investigated. It was found that the precursor copolymer contains crystallinity, which melts over a very wide temperature range. The amount of crystallinity is modified both by thermal history and applied shear. Thermal analysis can be used to determine processing/annealing temperatures for samples with unknown thermal history. It was found that the precursor possessed a maximum elongation at break at 70°C. Stretching was carried out at 70°C using a laboratory‐based tentering process, to produce both uniaxial and biaxial films. Films were characterized to monitor their shrinkage behavior, and orientation was measured by birefringence. Their tensile properties were measured with respect to stretching direction. Using tentering, which is carried out at relatively low temperatures, large amounts of orientation were produced, resulting in a significant increase in tensile strength, and decrease in elongation at break.
Effects of carbon nanotubes on the crystallization behavior of polypropylene
Authors: Valentini L. , Biagiotti J. , López‐Manchado M. A. , Santucci S. , Kenny J. M. 
Published: March 2004

AbstractThe effect of the incorporation of single‐walled carbon nanotubes (SWNTs) on the PP crystallization kinetics is investigated by thermal analysis, microscopy and Raman spectroscopy. The results of the investigation show that SWNT acts as a strong nucleation agent. A marked decrease of the half‐time of PP crystallization as well as a sensible increase of the overall crystallization rate is observed in the presence of SWNTs. Moreover, these effects are already noticeable at the lowest SWNT content in the composite with slow further effects at higher concentrations, suggesting a saturation of the nucleating action at the higher concentrations studied. The Avrami model can represent the crystallization kinetics of PP in the composite. The kinetic curves obtained under non‐isothermal conditions confirm the results obtained in isothermal tests and demonstrate the nucleation ability of SWNTs on the PP crystallization. Raman spectroscopy and scanning electron microscopy (SEM) are successfully applied to demonstrate that in the composite films, the changes in the crystallization kinetics can be explained in terms of the changes of the distance between nanotubes in bundles following a different intercalation of the polymer matrix.
Structure modification of isotactic polypropylene by bi‐component nucleating systems
Authors: Sterzynski Tomasz , Øysæd Harry 
Published: March 2004

AbstractThe efficiency of heterogeneous nucleation of isotactic polypropylenes (iPP) with various isotacticity and MWD is estimated by an increase of the crystallization temperature (Tcr). A bi‐component nucleating system, composed of a pimelic acid and a calcium stearate, was added to the polymeric matrix in the molten state. The relative increase of Tcr is found to be independent on the structure stereo‐regularity of iPP. On the contrary, dependent on the polymer structure, the investigated nucleating system influences in a different way the creation of the β‐phase. The form of the DSC melting curves, for the β‐phase rich iPP samples, is discussed in terms of various preliminary cooling conditions. The transformation from a multi‐modal form of the DSC melting peak to a simple one is related to the lowering of the cooling rate and to the increase of the heating rate.
A proteomic view of cell physiology of Bacillus licheniformis
Authors: Voigt Birgit , Schweder Thomas , Becher Dörte , Ehrenreich Armin , Gottschalk Gerhard , Feesche Jörg , Maurer Karl‐Heinz , Hecker Michael 
Published: March 2004

AbstractThe still ongoing sequencing of Bacillus licheniformis at the Göttingen Sequencing Laboratory provides the basis for proteome studies of the bacterium. By using two‐dimensional (2‐D) electrophoresis and protein identification by mass spectrometry, we were able to create master gels for B. licheniformis cells grown either in minimal medium or in complex medium containing about 300 and 180 entries, respectively. With the DECODON Delta 2D software we identified the most abundant protein spots on the gels, which were shown to perform mainly basic metabolic functions in the cell such as translation, amino acid metabolism, glycolysis, and tricarboxylic acid (TCA) cycle. Based on the master gels, we were able to study the regulation of metabolic pathways such as glycolysis and TCA cycle. In cells grown in the presence of glucose a significant increase of the amount of some glycolytic enzymes (TpiA, GapA, Pgk, Pgm, Eno, Pyk) and of the pyruvate dehydrogenase (PdhA‐D) was found. At the same time, there is a strong repression of almost all TCA cycle enzymes and of the ATP synthase. Glucose also stimulates the acetate kinase (AckA) and the phosphotransacetylase (Pta) which are known to be involved in the overflow metabolism in B. subtilis. Furthermore, we began developing proteomic signatures for growth of B. licheniformis in complex medium. For this purpose, we compared the proteome pattern of exponentially growing cells with that of cells in different stages during stationary phase. The most obvious proteomic signature indicates that cells during stationary phase are subjected to a severe oxidative stress and a resulting protein stress. Furthermore, the level of many vegetative proteins is strongly reduced when the growth is arrested after entry into stationary phase. The data indicate that proteomics can be a valuable tool to describe the physiological state of B. licheniformis cell populations, e.g., of cells growing in a bioreactor.
Brain proteome of mice lacking the receptors for tumor necrosis factor α
Authors: Pejović Vojislav , Šoškić Vukić , Pan Weihong , Kastin Abba J. 
Published: March 2004

AbstractTumor necrosis factor α (TNFα) is involved in regulation of food intake, inflammatory response, and cancer cachexia. Its actions are mediated by at least two receptors: TNFR1 and TNFR2. We show that mice lacking the TNFα receptors have altered levels of proteins that take part in signal transduction, stress response, protein folding, glucose and amino acid metabolism, vesicle trafficking, and cytoskeletal arrangements. This is the first time that some of them have been associated with TNFα signaling pathways.
Tumor suppressor Smad4 mediates downregulation of the anti‐adhesive invasion‐promoting matricellular protein SPARC: Landscaping activity of Smad4 as revealed by a “secretome” analysis
Authors: Volmer Martin W. , Radacz Yvonne , Hahn Stephan A. , Klein‐Scory Susanne , Stühler Kai , Zapatka Marc , Schmiegel Wolff , Meyer Helmut E. , Schwarte‐Waldhoff Irmgard 
Published: March 2004

AbstractWe have demonstrated previously that restoration of Smad4 expression in Smad4‐deficient SW480 human colon carcinoma cells was adequate to suppress tumorigenicity and invasive potential, whereas cell growth in vitro was not affected. Here we show that Smad4‐positive and Smad4‐negative SW480 cells deposit extracellular matrices in tissue culture which are functionally different with respect to their adhesiveness. We present a “differential secretomics analysis” as the most direct approach to identify the underlying alterations. The protein composition of conditioned media produced by Smad4‐positive and Smad4‐negative SW480 cells was compared by two‐dimensional (2‐D) gel electrophoresis. A major group of protein spots was detected in media derived from Smad4‐negative cells, only, which were identified as “secreted protein, acidic and rich in cysteins” (SPARC) by mass spectrometry. SPARC expression in SW480 cells was suppressed by Smad4 at the level of transcription. SPARC is a glycoprotein of the extracellular matrix, characterized as an anti‐adhesive and invasion‐promoting protein. Differential secretomics appeared as a powerful method to identify a novel Smad4 target gene, which may be one of the players involved in reduced adhesiveness of extracellular matrices and thus consistent with Smad4's emerging role as an invasion suppressor.
Microheterogeneity of the major grass group 6 allergen Phl p 6: Analysis by mass spectrometry
Authors: Blume Cornelia , Lindner Buko , Becker Wolf‐Meinhard , Petersen Arnd 
Published: March 2004

AbstractThe precise structural characterization of allergens is a basic requirement to improve diagnostics and to find therapeutic strategies against allergic disorders. Natural grass pollen allergens exhibit a wide variety of isoforms and it is still unknown whether this microheterogeneity is essential for the allergic reaction or has a functional effect on sensitization. Well‐defined recombinant allergens are considered to replace natural allergens for clinical trials. For the major timothy grass pollen allergen Phl p 6 (∼12 kDa) and a recombinant rPhl p 6 we determined the structural microheterogeneity by two‐dimensional electrophoresis (2‐DE), high‐resolution electrospray ionization‐Fourier transform‐mass spectrometry (ESI‐FT‐MS) of the intact molecules, and by tryptic peptide mass fingerprinting using matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS). Natural Phl p 6 is a mixture of mainly two isoforms that differ by two amino acids leading to a mass difference of 5 Da. For each of this two isoforms six variants were identified with modifications at the C‐ and/or N‐terminus. The recombinant Phl p 6 comprises the same structure as one of the main isoforms indicating that it represents a major part of the natural Phl p 6.
Proteome analysis of intraclonal diversity of two Pseudomonas aeruginosa TB clone isolates
Authors: Arevalo‐Ferro Catalina , Buschmann Julia , Reil Gerold , Görg Angelika , Wiehlmann Lutz , Tümmler Burkhard , Eberl Leo , Riedel Kathrin 
Published: March 2004

AbstractTwo strains, Pseudomonas aeruginosa TB10839 and TB121838, which belong to the TB clonal lineage, have been isolated from sputa of cystic fibrosis patients. Despite the fact that the strains are closely related, their pathogenic potential differs dramatically: while strain TB10839 is capable of proliferating in polymorphonuclear granulocytes, strain TB121838 is not. Comparative two‐dimensional polyacrylamide gel electrophoresis coupled to matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF)‐mass spectrometry was employed to map the extracellular, intracellular, and surface sub‐proteomes of TB10839 and TB121838 and to identify differentially expressed proteins. About 4% of all detected protein spots were differentially expressed between both strains including absent or present spots and spots with a more than 2‐fold changed intensity. This percentage reflects a relatively high degree of intraclonal variability. Many of the protein spots in TB10839 that were missing or expressed at lower levels in TB121838 were identified as quorum‐sensing regulated virulence factors. It might be speculated that the increased expression of these proteins contributes to pathogenic competence of TB10839.
Double chip protein arrays using recombinant single‐chain Fv antibody fragments
Authors: Gilbert Ilka , Schiffmann Susanne , Rubenwolf Susanne , Jensen Kristian , Mai Thao , Albrecht Christian , Lankenau Andreas , Beste Gerald , Blank Kerstin , Gaub Hermann E. , Clausen‐Schaumann Hauke 
Published: March 2004

AbstractProtein arrays permit the parallel analysis of many different markers in a small sample volume. However, the problem of cross‐reactivity limits the degree of multiplexing in parallel sandwich immunoassays (using monoclonal antibodies (mAbs)), meaning antibodies must be prescreened in order to reduce false positives. In contrast, we use a second chip surface for the local application of detection antibodies, thereby efficiently eliminating antibody cross‐reactions. Here, we illustrate the potential advantages of using single‐chain Fv fragments rather than mAbs as capture and detection molecules with this double chip technology.
A combination of different mass spectroscopic techniques for the analysis of dynamic changes of histone modifications
Authors: Bonaldi Tiziana , Imhof Axel , Regula Jörg T. 
Published: March 2004

AbstractThe N‐terminal tails of the histones are subject to many enzyme‐mediated post‐translational modifications, such as lysine acetylation, lysine and arginine methylation, serine phosphorylation, poly‐ADP ribosylation and the attachment of the small peptide ubiquitin. These modifications, singly or in combination, are thought to generate an epigenetic code that specifies different patterns of gene activity. We present a detailed study on the mapping of histone post‐translational modifications using a combination of matrix‐assisted laser desorption/ionization‐time of flight and electrospray ionization tandem mass spectrometry analysis of peptides generated by protease cleavage of individual histones isolated from different developmental stages. Due to their high content in basic amino acid residues and in order to be able to quantitatively compare two different samples we developed a chemical derivatization protocol. This strategy enabled us to determine the primary sequence of the peptides and to unambiguously assign specific modifications. This method is generally applicable to histone samples from various sources and can be used to study changes of modification patterns during early embryonic development or tissue differentiation and regeneration.
Heterogeneous nuclear ribonucleoprotein A2/B1 identified as an autoantigen in autoimmune hepatitis by proteome analysis
Authors: Huguet Stèphanie , Labas Valèrie , Duclos‐Vallee Jean‐Charles , Bruneel Arnaud , Vinh Joëlle , Samuel Didier , Johanet Catherine , Ballot Eric 
Published: March 2004

AbstractOur aim was to characterize antinuclear antibody (ANA) targets in type 1 autoimmune hepatitis (AIH1) using a proteomic tool. ANA‐positive sera from 29 patients with AIH1 and 14 negative controls were analyzed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and immunoblotting. The principal antigens identified were a 30 kDa triplet band which was recognized by 79% of patient sera and 14% of control sera, and a 36 kDa antigen which was recognized by 52% and 14% of sera, respectively. The latter antigen was studied in more detail using two‐dimensional electrophoresis (2‐DE) and mass spectrometry (MS). Its identification corresponded to heterogeneous nuclear ribonucleoprotein A2/B1. This paper presents the first description of this protein as an antigen in AIH1.
Towards a standardized human proteome database: Quantitative proteome profiling of living cells
Authors: Traxler Elisabeth , Bayer Editha , Stöckl Johannes , Mohr Thomas , Lenz Christof , Gerner Christopher 
Published: March 2004

AbstractComparative proteome profiling, performed by two‐dimensional polyacrylamide gel electrophoresis or multidimensional protein identification technology, usually relies on the relative comparison of samples of interest with respect to a reference. Currently, no standardized quantitative protein expression database of human cells, facilitating data comparisons between different laboratories, exists. Recently, we have published two‐dimensional polyacrylamide gel electrophoresis‐based techniques to assess absolute protein data comprising protein amounts, synthesis rates and biological half‐lives (Mol. Cell. Proteomics 2002, 1, 528–537). Determination of protein amounts by fluorography of two‐dimensional gels was followed by the exact quantification of the amount of incorporated 35S radiolabel. Here we demonstrate an application of this highly standardized method to quiescent human T cells, phythaemagglutinin‐stimulated T cells and Jurkat cells, a human T lymphoblast cell line. While the protein composition of quiescent T cells differed significantly compared to that of Jurkat cells, it was only slightly different compared to the activated T cells. Synthesis profile analyses demonstrated that activated T cells clearly differed from the quiescent cells, performing apparently almost like lymphoblast cells. The great sensitivity of this approach was further demonstrated with human umbilical vein endothelial cells treated for six hours with vascular endothelial growth factor. While no significant alteration of protein amounts was detected at all upon activation, the synthesis rate of several proteins was found to be more than doubled.
Proteome analysis of Madrid E strain of Rickettsia prowazekii
Authors: Chao Chien‐Chung , Chelius Dirk , Zhang Terry , Daggle Lindsey , Ching Wei‐Mei 
Published: March 2004

AbstractRickettsia prowazekii, an obligate intracellular Gram‐negative bacterium, is the etiologic agent of epidemic typhus. The threat of typhus as a biological weapon lies in its stability in the dried louse feces and in its infection by inhalation of an aerosol. Consequently, it is listed as a select agent and warrants more research to understand its pathogenesis. Although the genomic DNA sequence of strain Madrid E has been completed, the actual expression of the individual protein has not been investigated. In order to provide a global view of the expressed protein profile, the whole cell lysate of purified rickettsia (Madrid E strain) was reduced, alkylated, and digested with trypsin. The total digest was characterized by a two‐dimensional liquid chromatography mass spectrometry system and analyzed with a modified version of the ProteomeX workstation. A total of 252 proteins out of 834 predicted protein‐coding genes were identified, 238 proteins were identified by the detection of at least two unique peptides. Only 14 proteins were identified by the detection of one unique peptide in all three separate analyses. Among the 238 proteins identified by multiple unique peptides, 230 proteins were found in at least two of three separate analyses. The reproducible and convenient methodology and the information described here have provided a foundation for future proteome study of various R. prowazekii strains with different virulence.
An antisense oligonucleotide to cIAP‐1 sensitizes prostate cancer cells to fas and TNFα mediated apoptosis
Authors: McEleny Kevin , Coffey Ronan , Morrissey Colm , Williamson Kate , Zangemeister‐Wittke Uwe , Fitzpatrick John M. , Watson R. William G. 
Published: March 2004

AbstractBACKGROUNDThe inhibitors of apoptosis (IAP) proteins are a family of structurally homologous caspase inhibitors. We synthesized an antisense oligonucleotide (AO) to target a region within the BIR domain of cIAP‐1 and examined its ability to facilitate apoptosis in prostate cancer cells.METHODSWe transfected the IAP AO into PC3 and DU145 cells and determined alterations in IAP expression using Western blotting. Apoptosis and viability were assessed using propidium iodide (PI) DNA incorporation with flow cytometry. Pacitaxel, caffeic acid phenethyl ester (CAPE), Fas antibody, and TNFα were used as ‘second hit’ agents in association with the AO.RESULTSWestern blotting showed a down‐regulation in cIAP‐1 expression and higher levels of spontaneous apoptosis in both cell types with no alteration in overall cell viability. AO sensitized PC3 cells, to Fas antibody and TNFα‐mediated apoptosis, but not to apoptosis mediated by paclitaxel or CAPE.CONCLUSIONScIAP‐1 down‐regulation increased spontaneous apoptosis in prostate cancer cells and sensitized PC3 cells to receptor‐mediated apoptosis.
Vitamin D receptor gene polymorphisms and prostate cancer risk
Authors: Cheteri Mahesh B. Keitheri , Stanford Janet L. , Friedrichsen Danielle M. , Peters Mette A. , Iwasaki Lori , Langlois Mariela C. , Feng Ziding , Ostrander Elaine A. 
Published: March 2004

AbstractBACKGROUNDVitamin D is a steroid hormone that is thought to play a role in the etiology and progression of prostate cancer. Hormone activity requires binding to the vitamin D receptor (VDR), which contains several genetic polymorphisms that have been associated with risk of prostate cancer. To further evaluate this relationship, we conducted a population‐based case‐control study of the VDR BsmI, FokI, and Poly‐A polymorphisms, and prostate cancer.METHODSGermline DNA samples and survey data from incident prostate cancer cases (n = 559) and controls (n = 523) of similar age (40–64 years) without a history of the disease who resided in King County, Washington were analyzed.RESULTSThe frequency of the BsmI, FokI, and Poly‐A genotypes were similar in cases and controls, and no overall association between any variants and prostate cancer risk were noted. Stratification by clinical features of disease revealed that among men with localized stage disease, the BsmI bb genotype was associated with a modest increase in risk (OR, 1.49; 95% CI, 1.02–2.17; P = 0.04) compared to the BB genotype.CONCLUSIONSThese results suggest that polymorphisms in the VDR gene are not strong predictors of prostate cancer risk among Caucasian men in the U.S. © 2004 Wiley‐Liss, Inc.