bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and characterization of the major proteins of ram seminal plasma
Authors: Bergeron Annick , Villemure Michèle , Lazure Claude , Manjunath Puttaswamy 
Published: May 2005

AbstractMammalian seminal plasma contains among others, two major families of proteins, namely spermadhesins and those proteins that contain fibronectin type II domains. Spermadhesins are the major proteins of boar and stallion seminal plasma and homologous proteins have been identified in the bull. These proteins appear to be involved in capacitation and sperm–egg interaction. In bovine seminal plasma, proteins containing fibronectin type II domains are the major proteins and are designated BSP proteins. These proteins play a role in sperm capacitation. In this study, we present the isolation and characterization of the major proteins of ram seminal plasma. Precipitated proteins from Suffolk ram seminal plasma were loaded onto a gelatin–Agarose column. The unadsorbed (fraction A) and retarded proteins (fraction B) were removed by washing the column with phosphate buffered‐saline and the adsorbed proteins (fraction C) were eluted with 5M urea. SDS–PAGE of fraction B indicated the presence of a 15.5 kDa protein, which is the major protein of ram seminal plasma (∼45% of total protein by weight) and was identified as a spermadhesin by N‐terminal sequencing. SDS–PAGE analysis of fraction C revealed the presence of four proteins, which represented ∼20% of total ram seminal plasma proteins by weight, and were identified as proteins of the BSP family and named RSP proteins. These RSP proteins were designated RSP‐15 kDa, RSP‐16 kDa, RSP‐22 kDa, and RSP‐24 kDa. Only RSP‐15 kDa and ‐16 kDa proteins cross‐reacted with antibodies against BSP proteins. Ram spermadhesin and RSP proteins interact with heparin but only RSP proteins bind to hen's egg yolk low‐density lipoprotein. In conclusion, spermadhesin is the major protein of ram seminal plasma and other major proteins belong to the BSP protein family. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
PU.1 protein expression has a positive linear association with protein expression of germinal centre B cell genes including BCL‐6, CD10, CD20 and CD22: identification of PU.1 putative binding sites in the BCL‐6 promotor
Authors: Torlakovic Emina , Malecka Agnieszka , Myklebust June H , Tierens Anne , Aasheim Hans‐Christian , Nesland Jahn M , Smeland Erlend , Kvaløy Stein , Delabie Jan 
Published: May 2005

AbstractThe transcription factor PU.1 has been shown to be crucial for the early stages of B cell development but its function at later stages of B cell development is less well known. We observed previously that PU.1 is expressed uniformly throughout the mature pre‐plasma cell B cell population, the only exception being a subpopulation of germinal centre (GC) cells which showed exceptionally high expression of PU.1. This suggested that PU.1 may also have a role in GC B cell biology. To test this hypothesis and to screen for possible genes regulated by PU.1, we first evaluated semi‐quantitatively the possible co‐expression of PU.1 with proteins known to be upregulated or downregulated during GC B cell development. Normal lymphoid tissues and 255 B cell non‐Hodgkin lymphomas of putative GC B cell origin were evaluated. PU.1 expression was positively associated with CD10 (p < 0.0001), CD20 (p = 0.043), CD22 (p = 0.005), CD79a (p = 0.024) and Bcl‐6 (p < 0.0001) and negatively associated with cytoplasmic immunoglobulin light‐chain expression (p = 0.036) in diffuse large B cell lymphoma. Identical or nearly identical associations were found in follicular lymphoma. Since CD20 is known to be partly regulated by PU.1 and putative PU.1‐binding sites have been described in the regulatory regions of the CD22, CD79a and CD10 genes, we looked for putative PU.1 binding sites in the BCL6 promotor. Four such putative PU.1 binding sites were identified. Further analysis by gel‐shift electromobility essay showed that PU.1 protein binds to three of the four putative binding sites in the BCL6 promotor. PU.1 and Bcl‐6 were also found to be upregulated in centroblasts in the normal GC, but jointly downregulated in a subpopulation of centrocytes. Our findings support the contention that PU.1 may also have an important role in GC B cell development. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Amplification and overexpression of c‐erbB‐2, epidermal growth factor receptor, and c‐met in biliary tract cancers
Authors: Nakazawa Kumiko , Dobashi Yoh , Suzuki Shioto , Fujii Hideki , Takeda Yasuhisa , Ooi Akishi 
Published: May 2005

AbstractCarcinomas of the biliary tract have a poor prognosis. It is important to understand the molecular genetic characteristics of these tumours in order to employ newer effective treatments and to improve patient prognosis. There is increasing evidence that overexpression of tyrosine kinase growth factor receptors such as ErbB‐2, epidermal growth factor receptor (EGFR), and Met may play important roles in the development of biliary tract carcinomas. The aim of this study was to assess the potential for novel chemotherapies targeting these receptors. Overexpression of the tyrosine kinase receptor proteins was examined by immunohistochemistry in 221 biliary tract carcinomas, of which 28 were from the intrahepatic bile duct, 78 from the extrahepatic bile duct, 89 from the gall bladder, and 26 from the ampulla of Vater. Positively stained tumours were further examined for gene amplification by fluorescence in situ hybridization. Overexpression of ErbB‐2 was found in 15.7%, 11.5%, and 5.1% of carcinomas of the gall bladder, ampulla of Vater, and extrahepatic bile duct, respectively, and gene amplification was present in 79% of these. Overexpression of EGFR was found in 8.1% of tumours with no predominant location and was also associated with gene amplification with high frequency (77%). Met overexpression, most frequent in intrahepatic bile duct carcinomas (21.4%), was not associated with gene amplification. It is proposed that the new adjuvant chemotherapies could be directed to carcinomas of the biliary tract in which ErbB‐2 and EGFR are overexpressed. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
First evidence supporting a potential role for the BMP/SMAD pathway in the progression of oestrogen receptor‐positive breast cancer
Authors: Helms Mike W , Packeisen Jens , August Christian , Schittek Birgit , Boecker Werner , Brandt Burkhard H , Buerger Horst 
Published: May 2005

AbstractOestrogen receptor expression is generally a sign of better tumour differentiation and comparatively good clinical outcome in invasive breast cancer. However, oestrogen receptor‐positive, poorly differentiated carcinomas with a poor clinical outcome exist. The underlying genetic mechanisms and the genes involved remain obscure, even though chromosome 7p gains seem to be associated with these uncommon tumours. In this study, we compared two subsets of oestrogen receptor‐positive breast cancers, which differed in tumour grade, cytogenetic instability, and tumour proliferation, for their differential gene expression in order to identify proteins involved in the progression of oestrogen receptor‐positive breast cancers. We were able to show by means of subtractive suppression hybridization, real‐time reverse transcriptase PCR, and tissue microarray analysis that expression of the bone morphogenetic protein receptor IB (BMPR‐IB) is a major hallmark of the progression and dedifferentiation of breast cancer. Strong expression of BMPR‐IB was associated with high tumour grade, high tumour proliferation, cytogenetic instability, and a poor prognosis in oestrogen receptor‐positive carcinomas. Western blot analysis revealed that downstream signalling of this receptor is mainly mediated via phosphorylation of SMAD 1 in oestrogen receptor‐positive breast cancer. Even though BMPR‐IB was expressed in oestrogen receptor‐positive and ‐negative breast cancers, an impact on tumour grade, proliferation, and cytogenetic instability, as parameters of tumour progression, could only be demonstrated in oestrogen receptor‐positive carcinomas. This pro‐proliferative effect was complemented by significant anti‐apoptotic activity, indicated by XIAP and IAP‐2 expression in BMPR‐IB‐positive carcinomas. These results show that the BMP/SMAD pathway is activated in breast cancer and may contribute to breast cancer progression and dedifferentiation in oestrogen receptor‐positive breast cancer. The definition of this pathway characterizes a new potential target in the molecular treatment of invasive breast cancer. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The negative effect of red tape on research
Authors: Boshier A. , Shakir S. A. W. , Telfer P. , Behr E. , Pakrashi T. , Camm A. J. 
Published: May 2005

AbstractPurposesTo describe the kind of the difficulties encountered when seeking research governance approval for a nationwide public health and genetic study—the Drug‐Induced Arrhythmia Risk Evaluation study—in England.MethodsDescription of the processes followed when seeking research governance approval for the Drug‐Induced Arrhythmia Risk Evaluation study—a case control study with annual follow‐up of cases and controls over 5 years, set in the English National Health Service (NHS).ResultsThe authors describe wide variations in NHS research governance approval procedures in England.ConclusionNHS research governance procedures in England are impeding the process of epidemiological studies; there is the need for a centralised NHS R&D approval of studies, which is analogous to MREC for ethical approval. Copyright © 2005 John Wiley & Sons, Ltd.
Pressure and trimethylaluminum effects on ethene/1‐hexene copolymerization with methylaluminoxane‐activated (1,2,4‐Me3Cp)2ZrCl2: Trimethylaluminum suppression of standard termination reactions after 1‐hexene insertion
Authors: Bruaseth Ingvild , Bahr Matthias , Gerhard Dirk , Rytter Erling 
Published: May 2005

AbstractEthene homopolymerizations and copolymerizations with 1‐hexene were catalyzed by methylaluminoxane‐activated (1,2,4‐Me3Cp)2ZrCl2. Investigations of the effects of various pressures on the homopolymerizations and copolymerizations and of the effects of different concentrations of trimethylaluminum (TMA) on the copolymerizations were performed. The characteristics of the ethene/1‐hexene copolymers agreed with expectations for changes in the ethene concentration: the incorporation of 1‐hexene decreased, whereas the melting point and crystallinity increased, with increasing pressure. The main termination mechanism of the homopolymerizations was β‐hydrogen transfer to the monomer. Termination mechanisms resulting in vinylidene unsaturations dominated in the copolymerizations. Standard termination mechanisms producing vinyl and trans‐vinylene unsaturations occurred in parallel and were not influenced by the ethene or TMA concentration. In addition, some chain transfer to TMA, producing saturated end groups after hydrolysis, occurred. Copolymerizations with different additions of TMA, with the other polymerization conditions kept constant, showed that the catalytic productivity [tons of polyethylene/(mol of Zr h)], the 1‐hexene incorporation, and the molecular weight (from gel permeation chromatography) were independent of the TMA concentration. Surprisingly, the vinylidene content decreased almost linearly with increasing TMA concentration. TMA might have coordinated to the catalytic site after 1‐hexene insertion and rotation to the β‐agostic state and, therefore, suppressed the standard termination reactions after 1‐hexene insertion. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2584–2597, 2005
N‐Bromosuccinimide as a thermal iniferter for radical polymerization
Authors: Zhou Hong , Jiang Jianguo , Zhang Keda 
Published: May 2005

AbstractN‐Bromosuccinimide (NBS) was used as a thermal iniferter for the initiation of the bulk polymerizations of methyl methacrylate, methyl acrylate, and styrene. The polymerizations showed the characteristics of a living polymerization: both the yields and the molecular weights of the resultant polymers increased linearly as the reaction time increased. The molecular weight distributions of the polymers were 1.42–1.95 under the studied conditions. The resultant polymers could be used as macroiniferters to reinitiate the polymerization of the second monomer. The copolymers poly(methyl methacrylate)‐b‐polystyrene and polystyrene‐b‐poly(methyl methacrylate) were obtained and characterized. End‐group analysis of the resultant poly(methyl methacrylate), poly(methyl acrylate), and polystyrene confirmed that NBS behaved as a thermal iniferter. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2567–2573, 2005
Hydration in a new semiaromatic polyamide observed by humidity‐controlled dynamic viscoelastometry and X‐ray diffraction
Authors: Uddin Ahmed Jalal , Gotoh Yasuo , Ohkoshi Yutaka , Nagura Masanobu , Endo Ryokei , Hara Tetsuya 
Published: May 2005

AbstractHydration in a new semiaromatic polyamide, named polyamide 9‐T (PA9‐T), a copolymer of terephthalic acid with n‐ and iso‐nonanediamines, is studied by dynamic viscoelastic analysis under controlled humidity conditions and wide‐angle X‐ray diffraction analysis in comparison with common polyamide nylon 6. The storage modulus of PA9‐T is retained at up to 60 °C with increasing humidity, then dropped with further increases in temperature past 70 °C. The decrease in mechanical properties at 70 °C due to moisture uptake is found to be substantially improved by annealing to develop molecular packing and/or crystallization. In contrast, the storage modulus of very highly crystallized (50% crystallinity) nylon 6 decreases markedly with humidity at low temperatures such as 20 °C. Thus, PA9‐T retains its mechanical properties in humid atmospheres at much higher temperatures than nylon 6. The crystalline X‐ray diffraction peaks for nylon 6 corresponding to (002) + (202) of the α form shift upon absorption of moisture, speculated to be due to the weakening of hydrogen bonds and the subsequent conformational disordering of the chains. Unlike nylon 6, the crystalline peaks of PA9‐T do not shift due to moisture uptake. This is considered to be attributable to that the long aliphatic chain in PA9‐T forms the large hydrophobic domain, rendering PA9‐T less hygroscopic than nylon 6. Additionally, strong hydrogen bonds formed by terephthalamide residues together with a strong stacking force of phenylene groups may also repel water, preventing moisture bind with the amide groups of PA9‐T crystals. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1640–1648, 2005
Thermomechanical properties and phase structure of epoxy/silica nano‐hybrid materials constructed from a linear silicone oligomer
Authors: Ochi Mitsukazu , Matsumura Tomoyuki 
Published: May 2005

AbstractEpoxy‐grafted silicone oligomer (ESO), which has a linear silicone chain in the backbone moiety, was synthesized from a trifunctional alkoxysilane via a sol–gel reaction. Characterization of ESO was performed with 1H and 29Si NMR, Fourier transform infrared, and gel permeation chromatography. The number‐average molecular weight of ESO was 3300. By adding the silicone oligomer as the inorganic source in the curing process of the epoxy resin, novel epoxy/silica hybrid materials were prepared. It was observed by transmission electron microscope that fine silica‐rich domains of about 5‐nm diameter were uniformly dispersed in the cured epoxy matrix. Thermomechanical properties of the hybrid materials were also investigated. The storage modulus in the rubbery region and the peak area of the tan δ curve at the glass‐transition region increased and decreased, respectively, with the hybridization of the silica network. The mobility of the epoxy network chains should be considerably suppressed by the hybridization with the silica network. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1631–1639, 2005
Exploring the charge space of protein–protein association: A proteomic study
Authors: Shaul Yossi , Schreiber Gideon 
Published: May 2005

AbstractThe rate of association of a protein complex is a function of an intrinsic basal rate and of the magnitude of electrostatic steering. In the present study we analyze the contribution of electrostatics towards the association rate of proteins in a database of 68 transient hetero‐protein–protein complexes. Our calculations are based on an upgraded version of the computer algorithm PARE, which was shown to successfully predict the impact of mutations on kon by calculating the difference in Columbic energy of interaction of a pair of proteins. HyPare (http://bip.weizmann.ac.il/HyPare), automatically calculates the impact of mutations on a per‐residue basis for all residues of a protein–protein interaction, achieving a precision similar to that of PARE. Our calculations show that electrostatics play a marginal role (<10 fold) in determining the rate of association for about half of the complexes in the database. Strong electrostatic steering, which results in an increase of over 100‐fold in kon, was calculated for about 25% of the complexes. Applying HyPare to all 68 complexes in the database shows that a small number of residues are hotspots for association. About 40% of the hotspots are calculated to increase the rate of association upon mutation, and thus increase binding affinity. This is a much higher ratio than found for hotspots for dissociation, where the large majority cause weaker binding. About 40% of the hotspots are located outside the physical boundary of the binding site, making them ideal candidates for protein engineering. Our data shows that a majority of protein–protein complexes are not optimized for fast association. Hotspots are not evenly distributed between all types of amino acids. About 75% of all hotspots are of charged residues. This is understandable, as a charge‐reverse mutant changes the total charge by 2. The small number of hydrophobic residues that are hotspots upon mutation probably relates to their location and surrounding. For 18 out of the 68 complexes in the database, experimental values of kon are available. For these, a basal rate of association was calculated to be in the range of 104M−1s−1 to 107M−1s−1. Some of these rates were verified independently from experimental mutant data. The basal rates were correlated with the size of the proteins and the shape of the interface. Proteins 2005. © 2005 Wiley‐Liss, Inc.
A new relaxed state in horse methemoglobin characterized by crystallographic studies
Authors: Sankaranarayanan R. , Biswal B.K. , Vijayan M. 
Published: May 2005

AbstractA new relaxed state has been characterized in the crystals of horse methemoglobin grown at neutral pH at low ionic concentration and their low humidity variants. The crystals provide an example for improvement in X‐ray diffraction quality with reduced solvent content. Only the classical R state has been so far observed in liganded horse hemoglobin. The state characterized in the present study lies in between the R state and the R2 state characterized earlier in liganded human hemoglobin. The results presented here, along with those of earlier studies, suggest that relaxed and tense hemoglobin can access ensembles of states. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Effect of dense plasma on the spectral properties of hydrogenic ions
Authors: Sil A. N. , Saha B. , Mukherjee P. K. 
Published: May 2005

AbstractThe effect of strongly coupled plasma on the energy levels, dynamic polarizabilities, oscillator strengths, and transition probabilities of a number of hydrogenic ions is estimated, using the ion‐sphere (IS) model. The transition properties are calculated using time‐dependent variation perturbation theory. The variation of the atomic properties under different plasma densities are analyzed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Ab initio study of the far infrared spectrum of glycine
Authors: Senent M. L. , Villa M. , Domínguez‐Gómez R. , Fernández‐Clavero A. 
Published: May 2005

AbstractIn glycine, four large amplitude vibrations, the three internal rotations of the CC, COH, and CN bonds, and the amine group inversion are responsible for the nonrigidity of the molecule. They present 12 potential energy surface minima corresponding to eight different conformers. The energy levels for the four motions mentioned above and the HNH bending were determined using ab initio calculations and three different flexible models in one, two, and three dimensions. For this purpose, eight different MP4/cc‐pVTZ potential energy surfaces, five one‐dimensional for each internal coordinate, one two‐dimensional potential depending on the amine wagging and bending coordinates, and one three‐dimensional potential depending on the three internal rotation coordinates, were calculated. For the most stable conformer, the harmonic frequencies corresponding to the HNH bending, NH2 inversion, and the CC, COH, and CN torsions were calculated at 1677, 955, 65, 657, and 218 cm−1, and the anharmonic fundamental frequencies to be 1454, 803, 78, 522, and 175 cm−1 with the one‐dimensional model. The NHN bending and amine wagging fundamentals are determined to be 1688, and 799 with the two‐dimensional model. The fundamentals of the CC, COH and CN torsions were calculated to be 86, 546, and 189 cm−1 with the three‐dimensional model. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Analytic atomic wave functions of NMCSCF quality: Applications
Authors: Xiong Z. , Velgakis M. I. , Bacalis N. C. 
Published: May 2005

AbstractConcise analytic, nonorthogonal but selectively orthogonalizable, modified Laguerre type atomic orbitals are developed, providing conciseness, clear physical interpretation, and near‐equivalent accuracy with numerical multi‐configuration self‐consistent field, to atomic configuration interaction calculations. By analyzing the general Eckart theorem, which introduces an energy augmentation to the variational criterion for excited states, securing against variational collapse, we use them to calculate several excited atomic states known to be in danger of suffering from variational collapse. We also use them to calculate highly excited states, applied to computation of recently measured VUV spectra of He states near the second ionization threshold. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Cyanobacteria/cyanotoxin research—Looking back for the future: The opening lecture of the 6th ICTC, Bergen, Norway
Authors: Skulberg Olav M. 
Published: May 2005

AbstractA retrospective view of the development of research on cyanobacteria and their toxins—in Norway and worldwide—is cursorily examined. Combined with a personal narrative of the work and life of the author, the relevant research progress in the last 50 years of the 20th century is outlined. This was the period in biology when research of toxigenic cyanobacteria was coming to a head. The knowledge and understanding achieved were the result of a collective international enterprise binding the community of specialists together. The noxious organisms were isolated, and the basic chemistry, physiology, and toxicology of the specific cyanotoxins were settled. At the threshold today of what is widely regarded as the century of biology, the study of toxigenic cyanobacteria is undergoing important transformations. New frontiers include the interface between molecular biology, biochemistry, toxicology, and ecology. The results of the basic and applied research efforts will expand the understanding of cyanobacteria and be beneficial to the management of natural resources and the care of human beings. The tiny cyanobacteria, being a geological force in the dynamics of the globe, will continually become more central to the modern world and be applied more closely, affecting our lives. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 220–228, 2005.