bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteomic analysis of hyperoxia‐induced responses in the human choriocarcinoma cell line JEG‐3
Authors: Vorum Henrik , Østergaard Morten , Hensechke Philip , Enghild Jan J. , Riazati Mahtab , Rice Gregory E. 
Published: February 2004

AbstractLiving cells exposed to changes in the surrounding oxygen tension, have the ability to adapt to the new environment through the regulatory effect of intracellular mediators. In an effort to identify important proteins that may be involved in the hyperoxic response, we performed proteomic analysis on the human choriocarcinoma cell line JEG‐3, incubated under high oxygen tension (carbogen, 95% O2/5% CO2) or air (21% oxygen/5% CO2). We identified 13 protein spots that were significantly down‐regulated (p < 0.05) in JEG‐3 cells incubated under hyperoxic conditions compared to standard conditions. Ten of these spots were positively identified by matrix‐assisted laser desorption/ionization time of flight‐mass spectrometry as nine different proteins: Villin 2, tublin β, profilin I, glyceraldehyde‐3‐phosphate dehydrogenase, phosphoglycerate mutase, peroxiredoxin 1, neuroplypeptide h3, poly(rC)‐binding protein 1 and cyclophilin A. These proteins have been implicated in regulating cytoskeletal structure, glycolysis, redox status, signal transduction, transcription and protein folding. The data obtained are consistent with the roles of these proteins in mediating cellular response to oxidative stress and in regulating cell proliferation and motility.
Preparation of human heart for laser microdissection and proteomics
Authors: De Souza Ayesha I. , McGregor Emma , Dunn Michael J. , Rose Marlene L. 
Published: February 2004

AbstractProteomics generates information on expressed proteins, and laser microdissection (LMD) is a method that allows enrichment of specific cell types from complex heterogeneous tissue. Together they provide a powerful tool for functional genomic research. Here, we have investigated (i) the effects of fixation and staining on cardiac proteins separated by two‐dimensional gel electrophoresis (2‐DE) and (ii) feasibility of using LMD to separately prepare myocytes and blood vessels for 2‐DE gel analysis. This is the first such study of human heart. The effect of fixation (ethanol or acetone), staining with haematoxylin and eosin in the presence and absence of xylene, and antibody staining was investigated. Proteins were separated by 2‐DE and spots detected by silver staining. Quantitative spot analysis showed that contractile proteins were preserved under all conditions, and no significant differences were found when the groups studied were compared with the control group. However, there were differences in the visual quality of the gel patterns. LMD provided enough protein from blood vessels and myocytes to run one large‐format (18×24 cm) 2‐D gel for each subset of cells. Collection of this material took 70 h (≈︁ 2800 blood vessels and 17 000 myocytes) and resulted in tissue‐specific gel patterns for these two structures. In conclusion, the use of haematoxylin and eosin staining without xylene provided the best morphology and did not significantly affect protein spot number.
Mechanisms of hydrazine toxicity in rat liver investigated by proteomics and multivariate data analysis
Authors: Guldberg Klenø Tina , Rønnedal Leonardsen Lise , Ørsted Kjeldal Helle , Møller Laursen Steen , Nørregaard Jensen Ole , Baunsgaard Dorrit 
Published: February 2004

AbstractA proteomics approach combined with multivariate data analysis was used to examine the hepatotoxic effect of hydrazine in 30 male Sprague Dawley rats, assigned to four treatment groups and two control groups. Liver samples from the individual animals were resolved by two‐dimensional differential gel electrophoresis (2‐D DIGE) and protein patterns from the 2‐D gels were analyzed by principal component analysis (PCA) and partial least squares regression (PLSR). The PCA plot was able to describe the variation in the protein expression related to dose and time, by separation or clustering of different animal groups. PLSR followed by variable selection (Jack‐knifing) was used to select proteins that varied significantly in relation to the dose related response of the hydrazine treatment. The 10 up‐regulated and 10 down‐regulated proteins with highest rank in the PLSR model were identified by mass spectrometry. Hydrazine treatment induced altered expression of proteins related to lipid metabolism, Ca2+ homeostasis, thyroid hormone pathways and stress response. Several of the identified proteins have not previously been implicated in hydrazine toxicity and may thus be regarded as new potential biomarkers of induced liver toxicity.
Proteomics of methylene blue photo‐treated plasma before and after removal of the dye by an absorbent filter
Authors: Crettaz David , Sensebe Luc , Vu Dinh‐Hao , Schneider Philippe , Depasse François , Bienvenut Willy‐Vincent , Quadroni Manfredo , Tissot Jean‐Daniel 
Published: February 2004

AbstractMethylene blue (MB) and light are used for virus inactivation of plasma for transfusion. However, the presence of MB has been the subject of concern, and efforts have been made to efficiently remove the dye after photo‐treatment. For this study, plasma was collected by apheresis from 10 donors (group A), then treated using the MacoPharma THERAFLEX procedure (MB; 1 μM, and light exposure; 180 J/cm2) (group B), and finally filtered in order to remove the dye (group C). Proteins were analyzed by two‐dimensional electrophoresis, and peptides showing modifications were characterized by mass spectrometry. Clottable and antigenic fibrinogen levels, as well as fibrin polymerization time were measured. Analyses of the gels focused on a region corresponding to pI between 4.5 and 6.5, and Mr from 7000 to 58 000. In this area, 387 ± 47 spots matched, and four of these spots presented significant modifications. They corresponded to changes of the γ‐chain of fibrinogen, of transthyretin, and of apolipoprotein A‐I, respectively. A decrease of clottable fibrinogen and a prolongation of fibrin polymerization time were observed in groups B and C. Removal of MB by filtration was not responsible for additional protein alterations. The effect of over‐treatment of plasma by very high concentrations of MB (50 μM) in association with prolonged light exposure (3 h) was also analyzed, and showed complex alterations of most of the plasma proteins, including fibrinogen γ‐chain, transthyretin, and apolipoprotein A‐I. Our data indicates that MB treatment at high concentration and prolonged illumination severely injure plasma proteins. By contrast, at the MB concentration used to inactivate viruses, damages are apparently very restricted.
Determination of the stoichiometry of protein complexes using liquid chromatography with fluorescence and mass spectrometric detection of fluorescently labeled proteolytic peptides
Authors: Hochleitner Elisabeth O. , Sondermann Peter , Lottspeich Friedrich 
Published: February 2004

AbstractA method for the determination of the stoichiometry of protein complexes has been developed, which is based on proteolytic digestion of the complex, labeling with a fluorescent reagent, specific for amino or sulfhydryl groups, and separation by liquid chromatography with fluorescence and mass spectrometric detection. The intensity of the fluorescence signal of the labeled peptides resulting from different proteins is directly proportional to the stoichiometry of these proteins in the complex. The performance of the method was evaluated with standard peptides and proteins to ensure that accurate molar ratios can be obtained from the fluorescence chromatogram. Standard deviations of the measured molar ratio from the expected molar ratio were below 10% for both peptides and proteins. The method was finally employed for the determination of the stoichiometry of the 1:1 complex of sFcγRIII and hFc1. Using the described methodology, a stoichiometry of 1:1.1 was measured, which agrees well with a 1:1 complex.
A DSC Analysis of Inverse Salt‐pair Explosive Composition
Authors: Babu E. Suresh , Kaur Sukhminder 
Published: February 2004

AbstractAlkali nitrates are used as an ingredient in low explosive compositions and pyrotechnics. It has been suggested that alkali nitrates can form inverse salt‐pair explosives with the addition of ammonium chloride. Therefore, the thermal behavior of low explosive compositions containing potassium nitrate mixed with ammonium chloride has been studied using Differential Scanning Calorimetry (DSC). Results provide information about the ion exchange reaction between these two chemical substances and the temperature region at which the formation of a cloud of salt particles of potassium chloride takes place. Furthermore, the addition of ammonium chloride quenches the flame of deflagrating compositions and causes the mixture to undergo explosive decomposition at relatively low temperatures.
Static Electric Sensitivity Characteristics of Zr/BaCrO4 Pyrolants
Authors: Kuwahara Takuo , Kohno Takehiro , Wang Chia Hsiang 
Published: February 2004

AbstractZirconium (Zr) easily ignites in air atmosphere and generates high‐energy output. Therefore, it is used as a fuel for pyrolants. Barium chromate (BaCrO4) dose not ignite in air, so it is one of safety materials and it is used as oxidizer. These materials are mixed with viton as coating material/agent, since viton is easily dissolved in acetone. The static electric sensitivity of only‐BaCrO4‐coated material is lower than that of Zr‐coated one. The static electric energy, E, influences the chemical and the physical ignition delay times and they decrease with increasing E. The chemical ignition delay time decreases with increasing concentration of Zr. The chemical and physical ignition delay times of only‐BaCrO4‐coated pyrolant are longer than those of both‐coated material and only‐Zr‐coated, so the pyrolant of only‐BaCrO4‐coated pyrolant is the safer material.
Nanomaterials for Heterogeneous Combustion
Authors: Pivkina Alla , Ulyanova Polina , Frolov Yurii , Zavyalov Sergey , Schoonman Joop 
Published: February 2004

AbstractNanophase materials and nanocomposites, characterized by an ultra fine grain size (less than 100 nm) have attracted wide spread interest in recent years by virtue of their unusual mechanical, electrical, optical, magnetic, and energetic properties. Studies have shown that the thermal behavior of nano‐scaled materials is quite different from micron‐sized powders. Nanosized metallic and explosive powders have been used as solid propellant and explosive mixtures to increase efficiency. At the same time recent studies reveal that the presence of nanosized metals in propellants does not necessary translate into an increased burning rate and burning temperature. The reasons of this effect are far from being clear. This paper presents a new approach to the production of nanocomposites of some energetic materials – ammonium nitrite, cyclotrimethylene trinitramine (RDX), and aluminum – by the vacuum co‐deposition technique. The thermal behavior of the synthesized nanopowder and nanocomposites is investigated. A substantial difference in burning rate of RDX nanopowder has been found in comparison to micron‐sized material. Experimental results allow investigating the effects of nanosized materials on the combustion characteristics.
Effects of Nanometer Ni, Cu, Al and NiCu Powders on the Thermal Decomposition of Ammonium Perchlorate
Authors: Liu Leili , Li Fengsheng , Tan Linghua , Ming Li , Yi Yang 
Published: February 2004

AbstractA study of the decomposition behaviour for Ammonium Perchlorate(AP) was carried out by differential thermal analysis and the two decomposition peaks were observed. The high temperature peak was found to shift to lower temperatures, but the corresponding shift in the low temperature peak was smaller due to the effect of nanometer metal powders. Results shows that Cu and NiCu nanopowders decreased both the high and low decomposition temperature, while Ni and Al nanopowders just decreased the high decomposition temperature and increased the low decomposition temperature. Metal micron‐sized powders show catalytic effects on the thermal decomposition of AP, but their effects are less than that of nanometer metal powders. With the increase in content, nanometer metal powders enhanced their catalytic effect on the high temperature decomposition of AP, however their effect was weakened on the low temperature decomposition.
The Effects of Containment on Detonation Velocity
Authors: Souers P. Clark , Vitello Peter , Esen Sedat , Kruttschnitt Julius , Bilgin H. A. 
Published: February 2004

AbstractReactive flow cylinder code runs on six explosives were made with rate constants varying from 0.03 to 70 μs−1. Six unconfined/steel sets of original ANFO and dynamite data are presented. A means of comparing confinement effects both at constant radius and at constant detonation velocity is presented. Calculations show two qualitatively different modes of behavior. For Us/Co≥1.2, where Us is the detonation velocity and Co the zero‐pressure sound speed in steel, we find a sharp shock wave in the metal. The shock passes through the steel and the outer wall has a velocity jump‐off. For Us/Co≤1.04, we find a pressure gradient that moves at the detonation velocity. A precursor pulse drives in the explosive ahead of the detonation front. The outer wall begins to move outward at the same time the shock arrives in the explosive, and the outer wall slowly and continuously increases in velocity. The Us/Co≥1.2 cylinders saturate in detonation velocity for thick walls but the Us/Co<<1.04 case does not. The unconfined cylinder shows an edge lag in the front that approximately equals the reaction zone length, but the highly confined detonation front is straight and contains no reaction zone information. The wall thickness divided by the reaction zone length yields a dimensionless wall thickness, which allows comparison of explosives with different detonation rates. Even so, a rate effect is found in the detonation velocities, which amounts to the inverse 0.15–0.5 power.
Metal/Fluorocarbon Pyrolants: V. Theoretical Evaluation of the Combustion Performance of Metal/Fluorocarbon Pyrolants based on Strained Fluorocarbons
Authors: Koch Ernst‐Christian 
Published: February 2004

AbstractThe potential of strained fluorocarbons, which can act as oxidizers in metal‐based pyrolant systems, is investigated. The oxidizing performance of fluorocarbons is evaluated by the enthalpy of combustion ΔcH(298K) and the fractional electron transfer ΔN. ΔcH(298K) can be related to hybridisation, molar C/F ratio and strain of the parent carbon skeleton of the fluorocarbon. Considered fluorocarbons are tetrafluorotetrahedrane (CF)4 (3), tetrakis(trifluoromethyl)tetrahedrane C4(CF3)4 (4), hexafluoro[3]prismane (CF)6 (5), hexakis(trifluoromethyl)[3]prismane C6(CF3)6 (6), octafluorocubane (CF)8 (7), octakis(trifluoromethyl)cubane C8(CF3)8 (8), eicosafluorododecahedrane (CF)20 (9), eicosakis(trifluoromethyl)dodecahedrane C20(CF3)20 (10), C60F48 (11) and perfluorofullerane (CF)60 (12). Powerful oxidisers in terms of exothermicity are those possessing both tertiary CF‐units and strained carbon skeletons. Nevertheless the reactivity, which is estimated on basis of ΔN, the fraction of electrons transferred according to Pearson, has been found to be high with the corresponding perfluoromethyl derivatives and maximum with the fluorofulleranes. For part IV see Ref. 17.
Calculation of the Detonation Velocities and Detonation Pressures of Dinitrobiuret (DNB) and Diaminotetrazolium Nitrate (HDAT‐NO3)
Authors: Geith Janna , Klapötke Thomas M. , Weigand Jan , Holl Gerhard 
Published: February 2004

AbstractThe enthalpies of combustion (ΔcombH) of dinitrobiuret (DNB) and diaminotetrazolium nitrate (HDAT‐NO3) were determined experimentally using oxygen bomb calorimetry: ΔcombH(DNB)=5195±200 kJ kg−1, ΔcombH(HDAT‐NO3)=7900±300 kJ kg−1. The standard enthalpies of formation (ΔfH°) of DNB and HDAT‐NO3 were obtained on the basis of quantum chemical computations at the electron‐correlated ab initio MP2 (second order Møller‐Plesset perturbation theory) level of theory using a correlation consistent double‐zeta basis set (cc‐pVTZ): ΔfH°(DNB)=−353 kJ mol−1, −1 829 kJ kg−1; ΔfH°(HDAT‐NO3)=+254 kJ mol−1, +1 558 kJ kg−1. The detonation velocities (D) and detonation pressures (P) of DNB and HDAT‐NO3 were calculated using the empirical equations by Kamlet and Jacobs: D(DNB)=8.66 mm μs−1, P(DNB)=33.9 GPa, D(HDAT‐NO3)=8.77 mm μs−1, P(HDAT‐NO3)=33.3 GPa.
Regulation of prostasin expression and function in the prostate
Authors: Chen Li‐Mei , Zhang Xiaochun , Chai Karl X. 
Published: February 2004

AbstractBACKGROUNDThe invasion suppressor prostasin is down‐regulated in prostate cancer, but the mechanism is unknown. A prostasin‐binding protein (PBP) was found in the seminal vesicles, but its identity remains unclear.METHODSGenomic Southern blot analysis using methylation sensitive restriction endonucleases was employed to examine the prostasin gene promoter region in prostate cancer cell lines. RT‐PCR was employed to examine prostasin expression under demethylation, histone deacetylase inhibition, and nerve growth factor (NGF) treatment. Liquid column chromatography was employed to purify the PBP from mouse seminal vesicles. The PBP was further characterized by amino acid sequence analysis, recombinant protein expression, protease inhibition and binding assays. Immunohistochemistry and Western blot analysis were used to evaluate PBP expression in the prostate and prostate cancer cells.RESULTSPromoter DNA methylation partly causes the prostasin down‐regulation in DU‐145 and PC‐3 cells, while prostasin expression can be induced by NGF. The PBP is identified to be protease nexin‐1 (PN‐1), a serpin. PN‐1 inhibits prostasin's serine protease activity, is expressed by prostate epithelial cells (PrECs) and prostate cancer cells, and capable of binding to membrane‐anchored prostasin.CONCLUSIONSProstasin's expression and function are regulated by factors in the prostate tissue environment. © 2003 Wiley‐Liss, Inc.
Treatment of epigallocatechin‐3‐gallate inhibits matrix metalloproteinases‐2 and ‐9 via inhibition of activation of mitogen‐activated protein kinases, c‐jun and NF‐κB in human prostate carcinoma DU‐145 cells
Authors: Vayalil Praveen K. , Katiyar Santosh K. 
Published: February 2004

AbstractBACKGROUNDMatrix metalloproteinases (MMPs) are involved in tumor progression including the carcinoma of the prostate (CaP). Therefore, the effect of (−)‐epigallocatechin‐3‐gallate (EGCG) was determined on the synthesis and activation of tumor invasion‐specific MMP‐2 and MMP‐9 in human prostate carcinoma DU‐145 cells.METHODSMMP‐2 and MMP‐9 were determined by zymography and Western blot analysis. Since fibroblast conditioned medium (FCM) partially mimics in vivo tumor‐host microenvironment, DU145 cells were co‐cultured in FCM.RESULTSTreatment of EGCG to DU‐145 cells resulted in dose‐dependent inhibition of FCM‐induced pro and active both forms of MMP‐2 and MMP‐9 concomitant with marked inhibition of phosphorylation of ERK1/2 and p38. In identical conditions, treatment of EGCG or inhibitors of MEK or p38 to DU‐145 cells inhibited FCM‐induced phosphorylation of ERK1/2 and/or p38 concomitant reduction in MMP‐2 and ‐9. EGCG also inhibited androgen‐induced pro‐MMP‐2 expression in LNCaP cells. Further, treatment of EGCG also resulted in inhibition of activation of c‐jun and NF‐κB in in vitro DU‐145 cells.CONCLUSIONSThe inhibition of MMP‐2 and MMP‐9 in DU145 cells by EGCG is mediated via inhibition of phosphorylation of ERK1/2 and p38 pathways, and inhibition of activation of transcription factors c‐jun and NF‐κB. EGCG may play a role in prevention of invasive metastatic processes of both androgen‐dependent and ‐independent prostate carcinoma. © 2003 Wiley‐Liss, Inc.
Inhibition of cell signaling by the combi‐nitrosourea FD137 in the androgen independent DU145 prostate cancer cell line
Authors: Qiu Qiyu , Dudouit Fabienne , Banerjee Ranjita , McNamee James P. , Jean‐Claude Bertrand J. 
Published: February 2004

AbstractBACKGROUNDFD137, a nitrosourea appended to a quinazoline ring, was designed to simultaneously block epidermal growth factor receptor (EGFR)‐mediated signaling and damage genomic DNA in refractory EGF‐dependent prostate tumors.METHODSThe mixed inhibition of cell signaling and DNA damage by FD137 were determined by Western blotting, RT‐PCR, flow cytometry, sulforhodamine B (SRB), and comet assay.RESULTSFD137 and its metabolite FD110 induced a dose‐dependent increase in inhibition of EGF‐stimulated EGFR autophosphorylation and this translated into blockade of c‐fos gene expression in DU145 cells. FD137 induced significant levels of DNA damage and showed 150‐fold greater anti‐proliferative activity than BCNU, a classical nitrosourea. In contrast to BCNU, complete inhibition of EGF‐induced cell transition to S‐phase was observed at concentrations of FD137 as low as 3 μM.CONCLUSIONFD137 could not only damage DNA, but also significantly block downstream EGFR‐mediated signaling. The superior activity of FD137 may be imputable to the combined effect of its mixed EGFR/DNA targeting properties. This novel strategy may well represent a new approach to target nitrosoureas to EGFR‐overexpressing carcinomas of the prostate. © 2004 Wiley‐Liss, Inc.
P‐glycoprotein increases the efflux of the androgen dihydrotestosterone and reduces androgen responsive gene activity in prostate tumor cells
Authors: Fedoruk Matthew N. , Giménez‐Bonafé Pepita , Guns Emma S. , Mayer Lawrence D. , Nelson Colleen C. 
Published: February 2004

AbstractBACKGROUNDP‐glycoprotein (P‐gp) is commonly associated with multi‐drug resistance (MDR) in cancer cells and the efflux of a broad spectrum of chemicals from the cell, including many chemotherapeutics and certain steroid hormones. The impact of P‐gp and mechanisms involved in androgen transport and cellular accumulation within normal and malignant prostate cells remains unclear.METHODSFollowing incubation of LNCaP, PC‐3, HeLa, and HeLa FLAG–androgen receptor (AR) cells with 3H‐dihydrotestosterone (DHT) alone and in combination with P‐gp inhibitors, PSC‐833 and verapamil, we examined the cellular accumulation and efflux of androgens, as well as gene transcriptional response.RESULTSOur data reveal that the cellular transport and accumulation of DHT is dependent on the expression of functional AR and modulated by P‐gp. P‐gp over‐expression by both transient transfection and aspirin treatment in LNCaP cells showed decreased intracellular DHT accumulation, further suggesting DHT efflux is P‐gp regulated.CONCLUSIONSAndrogen responsiveness may be modulated by P‐gp in prostate cancer cells. The biological consequences of increased P‐gp expression are decreased androgen accumulation and a corresponding decrease in androgen‐regulated transcriptional activity and PSA gene expression. © 2004 Wiley‐Liss, Inc.