bluuebunny/crossref_metadata_2025_split huggingface dataset:
17β‐estradiol downregulates β3‐integrin expression in differentiating and mature human osteoclasts
Authors: Saintier D. , Burde M.‐A. , Rey J.M. , Maudelonde T. , de Vernejoul M.C. , Cohen‐Solal M.E. 
Published: November 2003

AbstractThe increased bone resorption observed after estrogen withdrawal is responsible for bone loss and may lead to osteoporosis. The mechanism by which estradiol inhibits bone resorption is known to involve decreased osteoclastogenesis, however, the effect on osteoclast adhesion remains unclear. We examined the in vitro effect of estradiol and raloxifene on human osteoclast differentiation and function. Human peripheral blood mononuclear cells were cultured with M‐CSF/RANK‐L for 18 days, and we evaluated bone resorption, the expression of the protein and mRNA of the integrins, c‐jun and c‐fos in the presence or absence of estradiol. In this human model, β3‐integrin expression increased at the mRNA and protein levels during osteoclast differentiation, whereas that of β5‐integrin did not. We found that estradiol and raloxifene directly inhibited bone resorption on bone slices by 50%, and decreased the expression of β3‐integrin mRNA (60%) and protein (20%) in a time‐dependent manner. Moreover, the mRNAs of c‐fos and c‐jun were both diminished by estradiol and raloxifene, particularly in early osteoclasts, but also to a lesser extent in mature cells. These findings suggest that the direct inhibitory action of estradiol on bone resorption may affect human osteoclast differentiation through downregulation of c‐fos and c‐jun and adhesion through modulation of β3‐integrin. J. Cell. Physiol. 198: 269–276, 2004© 2003 Wiley‐Liss, Inc.
Reduction of intracellular pH inhibits constitutive expression of Cyclooxygenase‐2 in human colon cancer cells
Authors: Pirkebner Daniela , Fuetsch Michaela , Wittmann Walter , Weiss Helmut , Haller Thomas , Schramek Herbert , Margreiter Raimund , Amberger Albert 
Published: November 2003

AbstractCyclooxygenase‐2 (COX‐2) over‐expression is critically involved in tumor formation. Intracellular pH (pHi) has been shown to be alkaline in cancer cells, and to be an important trigger for cell proliferation. This study therefore analyzed the relationship between pHi and COX‐2 expression. HRT‐18 and Caco‐2 cells cultured in medium with bicarbonate maintained a pHi of ∼7.6, which is higher than that of non‐neoplastic cells. Cells grown in bicarbonate‐free medium with a pH at 6.8 showed a reduction in pHi to approximately 7.0. Importantly, reduction of pHi resulted in a complete inhibition of COX‐2 mRNA and protein expression. When cells were grown in bicarbonate‐supplemented medium at pH 6.8, pHi maintained at ∼7.6 and COX‐2 expression was not inhibited. Additionally, analysis utilizing protein synthesis inhibitor cycloheximide demonstrated that pHi mediated inhibition of COX‐2 mRNA expression requires de novo protein synthesis of regulatory protein(s). These data strongly suggest that an alkaline pHi is an important trigger for constitutive COX‐2 expression. Defining pHi‐mediated mechanisms that govern the constitutive COX‐2 expression may help in developing new strategies to block COX‐2 over‐expression in cancer cells. J. Cell. Physiol. 198: 295–301, 2004© 2003 Wiley‐Liss, Inc.
Modulation of vascular smooth muscle cells proteoglycan synthesis by the extracellular matrix
Authors: Figueroa Julio E. , Oubre John , Vijayagopal Parakat 
Published: November 2003

AbstractIn this study, we investigated the effect of the extracellular matrix (ECM) secreted by vascular cells on proteoglycan (PG) synthesis by vascular smooth muscle cells in culture. PG synthesis of human aortic smooth muscle cells plated on plastic or the matrices derived from vascular endothelial cells, vascular smooth muscle cells, or THP‐1 macrophages was characterized. Smooth muscle cell and macrophage matrices increased both secreted and cellular smooth muscle cells PG production by 2.5‐fold to 3.9‐fold, respectively, over plastic and endothelial cell matrix. Macrophage matrix was more potent than smooth muscle cell matrix in this regard. Selective enzymatic removal of chondroitin sulfates, collagen, and elastin from smooth muscle cell matrix enhanced the stimulation of PG synthesis, as did the removal of chondroitin sulfates from macrophage matrix. PG turnover rates were similar for smooth muscle cells plated on the three matrices. The newly synthesized PG from cultures plated on smooth muscle cell‐, and macrophage‐derived matrices had greater charge density, larger molecular size, and longer glycosaminoglycan chains than those from endothelial cell matrix cultures. These data show that the ECM plays a major role in modulating vascular smooth muscle cell PG metabolism in vitro. J. Cell. Physiol. 198: 302–309, 2004© 2003 Wiley‐Liss, Inc.
Dermatan sulfate exerts an enhanced growth factor response on skeletal muscle satellite cell proliferation and migration
Authors: Villena Joan , Brandan Enrique 
Published: November 2003

AbstractSkeletal muscle regeneration is a complex process in which many agents are involved. When skeletal muscle suffers an injury, quiescent resident myoblasts called satellite cells are activated to proliferate, migrate, and finally differentiate. This whole process occurs in the presence of growth factors, the extracellular matrix (ECM), and infiltrating macrophages. We have shown previously that different proteoglycans, either present at the plasma membrane or the ECM, are involved in the differentiation process by regulating growth factor activity. In this article, we evaluated the role of glycosaminoglycans (GAGs) in myoblast proliferation and migration, using C2C12, a satellite cell‐derived cell line. A synergic stimulatory effect on myoblast proliferation was observed with hepatocyte growth factor (HGF) and fibroblast growth factor type 2 (FGF‐2), which was dependent on cell sulfation. The GAG dermatan sulfate (DS) enhanced HGF/FGF‐2‐dependent proliferation at 1–10 ng/ml. However, decorin, a proteoglycan containing DS, was unable to reproduce this enhanced proliferative effect. On the other hand, HGF strongly increased myoblast migration. The HGF‐dependent migratory process required the presence of sulfated proteoglycans/GAGs present on the myoblast surface, as inhibition of both cell sulfation, and heparitinase (Hase) and chondroitinase ABC (Chabc) treatment of myoblasts, resulted in a very strong inhibition of cell migration. Among the GAGs analyzed, DS most increased HGF‐dependent myoblast migration. Taken together, these findings showed that DS is an enhancer of growth factor‐dependent proliferation and migration, two critical processes involved in skeletal muscle formation. J. Cell. Physiol. 198: 169–178, 2004© 2003 Wiley‐Liss, Inc.
Aldehydes mediate tissue factor induction: A possible mechanism linking lipid peroxidation to thrombotic events
Authors: Cabré Anna , Girona Josefa , Vallvé Joan‐C. , Masana Lluís 
Published: November 2003

AbstractTissue factor (TF), which is expressed in atherosclerotic plaques and colocalizes with oxidized lipids, initiates the thrombogenic process. We have analyzed the effect of aldehydes derived from peroxidation of polyunsaturated fatty acids on TF expression in human vascular smooth muscle cells (HVSMC). Our results demonstrate that hexanal and 2,4‐decadienal (2,4‐DDE), two apolar aldehydes, increase TF expression. Exposure of HVSMC to hexanal for 2 h led to TF protein levels up to seven times higher than untreated cells whereas 2,4‐DDE for 30 min led to them being up to 2.2 times higher. This induction of TF antigen by aldehydes correlates with an increase in TF mRNA levels. Electrophoretic mobility shift assays (EMSAs) showed that the binding activity of the transcription factor AP‐1 (c‐Fos/c‐Jun) to TF promoter was elevated in response to these oxidation products. This enhancement was associated to an increase of c‐fos transcriptional activity, which was reversible by pretreatment with simvastatin. We conclude that the induction of TF by aldehydes might contribute to the severity of atherogenesis.
J. Cell. Physiol. 198: 230–236, 2004© 2003 Wiley‐Liss, Inc.
PDTC, metal chelating compound, induces G1 phase cell cycle arrest in vascular smooth muscle cells through inducing p21Cip1 expression: Involvement of p38 mitogen activated protein kinase
Authors: Moon Sung‐Kwon , Jung Sun‐Young , Choi Yung‐Hyun , Lee Young‐Choon , Patterson Cam , Kim Cheorl‐Ho 
Published: November 2003

AbstractPyrrolidine dithiocarbamate (PDTC), a metal chelating compound, is known to induce cell death in vascular smooth muscle cells (VSMC). However, the molecular mechanism for PDTC‐induced VSMC death is not well understood. Addition of PDTC reduced cell growth and DNA synthesis on VSMC in low density conditions. However, in serum depleted medium, PDTC did not affect the cell viability, suggesting that certain factors in serum may mediate the cytotoxic effect of PDTC. Several metal chelators prevented the cell death induced by PDTC. In a serum‐deprived condition, addition of exogenous metals, copper, iron, and zinc, restored the cytotoxic effect of PDTC. These data indicate that metals such as copper, iron, and zinc in serum may mediate the cytotoxic effect of PDTC. At low VSMC density in 10% FBS, treatment of PDTC, which induced a cell‐cycle block in G1‐phase, induced down‐regulation of cyclins and CDKs and up‐regulation of the CDK inhibitor p21 expression, whereas up‐regulation of p27 or p53 by PDTC was not observed. Finally, we determined PDTC‐mediated signaling pathway involved in VSMC death. Among relevant pathways, PDTC induced marked activation of p38MAPK and JNK. Expression of dominant negative p38MAPK and SB203580, a p38MAPK specific inhibitor, blocked PDTC‐dependent p38MAPK, growth inhibition, and p21 expression. These data demonstrate that the p38MAPK pathway participates in p21 induction, which consequently leads to decrease of cyclin D1/cdk4 and cyclin E/cdk2 complexes and PDTC‐dependent VSMC growth inhibition. In conclusion, an understanding of the molecular mechanisms of PDTC in VSMC provides a theoretical basis for clinical approaches using antioxidant therapies in atherosclerosis. J. Cell. Physiol. 198: 310–323, 2004© 2003 Wiley‐Liss, Inc.
Raman study of magnetite (Fe3O4): laser‐induced thermal effects and oxidation
Authors: Shebanova Olga N. , Lazor Peter 
Published: November 2003

AbstractNatural magnetite (Fe3O4) in the form of single crystal and powder was studied by laser Raman spectroscopy at various laser powers. The correlations between the power of the excitation laser, the temperature of the sampled spot and the degree of oxidation of magnetite were accurately established. In the course of the oxidation of the single crystal of magnetite, the first characteristic features of hematite appear at about 300 and 410 cm−1, at a temperature close to 240°C. This may explain the erroneous assignment of these modes to the intrinsic Raman modes of magnetite in some studies. For the finely powdered magnetite, which is much more easily prone to oxidation, the reaction mechanism proceeds via a metastable maghemite (γ‐Fe2O3) before the final product hematite is formed. Three independent methods based on the quasi‐harmonic approximation and on the ratio of the Stokes to anti‐Stokes intensities were used to calculate the local temperature of the laser‐heated spot. Temperature‐induced shifts of phonon bands were also evaluated. The phonons shift at the following rates: A1g − 0.023(1) cm−1 K−1, T2g(2) − 0.030(2) cm−1 K−1, Eg − 0.019(5) cm−1 K−1 and T2g(1) − 0.00(1) cm−1 K−1. Copyright © 2003 John Wiley & Sons, Ltd.
Density functional andab initiostudies of the molecular structure and vibrational spectra of novelO,O′‐diethyl‐N‐(α‐aryloxyacetyl)thiophosphorylhydrazine herbicides
Authors: Li Wei , Wu Qiaofeng , Ye Yong , Luo Mingdao , Shi Deqing , Hu Jiming 
Published: November 2003

AbstractThe ground‐state geometry, vibrational wavenumbers and thermodynamic parameters ofO,O′‐diethyl‐N‐(α‐acetonaphthalene)thiophosphorylhydrazine andO,O′‐diethyl‐N‐(α‐2‐methylphenoxyacetyl)thiophosphorylhydrazine were studied by DFT‐B3LYP, B3PW91 andab initioRHF methods. The optimized geometries and some thermodynamic parameters obtained by using different methods and basis sets were compared. The wavenumber of the stretching vibration of the CO group ofO,O′‐diethyl‐N‐(α‐acetonaphthalene)thiophosphorylhydrazine is shifted down significantly because of intra or intermolecular hydrogen bonds formed among the molecules. Copyright © 2003 John Wiley & Sons, Ltd.
Structural characterization of self‐assembled monolayers by unenhanced Raman spectroscopy
Authors: Choplin F. , Navarre S. , Bousbaa J. , Babin P. , Bennetau B. , Bruneel J.‐L. , Desbat B. 
Published: November 2003

AbstractThis paper presents unenhanced Raman spectra of self‐assembled monolayers [2‐(22‐trichlorosilanyldocosoxy)ethyl acetate], grafted on to silicon dioxide wafers, obtained by using a confocal Raman microscope. The quality of monolayer formation, at the micrometer scale, was monitored by drawing maps of a few square micrometers and homogeneous monolayers were obtained using a detergent cleaning procedure. The results are in good agreement with those obtained previously by atomic force microscopy studies. Copyright © 2003 John Wiley & Sons, Ltd.
Collaborative data processing in developing predictive models of complex reaction systems
Authors: Frenklach Michael , Packard Andrew , Seiler Pete , Feeley Ryan 
Published: November 2003

AbstractThe subject of this report is a methodology for the transformation of (experimental) data into predictive models. We use a concrete example, drawn from the field of combustion chemistry, and examine the data in terms of precisely defined modes of scientific collaboration. The numerical methodology that we employ is founded on a combination of response surface technique and robust control theory. The numerical results show that an essential element of scientific collaboration is collaborative processing of data, demonstrating that combining the entire collection of data into a joint analysis extracts substantially more of the information content of the data. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 36: 57–66, 2004
Itinerant ferromagnetism and antiferromagnetism from the perspective of chemical bonding
Authors: Dronskowski Richard 
Published: November 2003

AbstractThe quantum chemical tool crystal orbital Hamilton population (COHP) has been used for the analysis of bonding within metallic systems to predict the tendency for ferromagnetic and antiferromagnetic order. In these materials, the preference of bonding interactions and avoidance of antibonding interactions is realized not by conventional Jahn–Teller/Peierls distortions but simply by rearranging the spin sublattices upon spontaneous spin polarization. In general, spin‐restricted bonding analyses of itinerant metals with a tendency for ferromagnetic order (such as α‐Fe, Co, and Ni) exhibitantibondingstates at the Fermi level that disappear upon going ferromagnetic; within the elemental metals the onset of magnetism strengthens the metalmetal bond. A typical antiferromagnet (Cr) showsnonbondingstates in the highest bands that remain almost untouched during spin polarization. This bonding classification of potential ferro‐ or antiferromagnets also holds for intermetallic alloys and can be utilized for rational syntheses. The recipe is exemplified with the help of multinary iron/manganese rhodium borides in which various adjustments of the Fermi level have been synthetically realized. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Quantum chemical calculation of crystalline model of biomembrane
Authors: Evarestov R. A. , Stefanov V. E. , Karasev V. A. , Bandura A. V. 
Published: November 2003

AbstractA theoretical study on the possibility of protons transfer in biomembranes via continuous systems of hydrogen bonds was carried out on the basis of a simple crystalline model IPE–HCl (crystals of phosphatidylethanolamine titrated with HCl). A combined approach was used involving optimization of atomic structure by the method of molecular mechanics and subsequent nonempirical quantum chemistry calculation of the electronic structure of IPE–HCl. For hydrogen atoms, molecular mechanics yielded more precise positions compared to those found in the experimental X‐ray study (monoclinic space group C2/c, 240 atoms in primitive unit cell). Quantum chemistry calculation of the electronic structure of IPE–HCL crystal was performed on the basis of the optimized atomic positions. The nonempirical Hartree–Fock LCAO method is used as in computer code CRYSTAL. The calculated values of Mulliken charges on hydrogen atoms in P‐O‐H groups are essentially closer to those for protons than are the values of charge on other hydrogen atoms. This result supports the assumption about the importance of systems of hydrogen bonds in the membrane‐like structures. In agreement with the proton mechanism of energy transfer, presumed for biomembranes, total energy of the atomic configuration with transferred proton is close to that of undistorted structure. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Investigation of interatomic bonding in 3C‐SiC:M by nonempirical quantum chemistry methods
Authors: Yuryeva E. I. , Ivanovskii A. L. 
Published: November 2003

AbstractIn this work, the presence of 3d metal (MTi, V, Cr and Ni) impurity atoms in the cubic silicon carbide (3C‐SiC) was simulated theoretically. Electronic structure, parameters of chemical bonding, and binding energies were calculated by the cluster density functional theory DFT approach for M substitutions in silicon, carbon, and interstitial sites. The full‐potential FLMTO technique was employed to calculate the cohesive energy for the M → Si substitutions and the crystal lattice relaxation effects around the impurity atoms. We found that for stoichiometric substitutions all 3d impurities occupy Si positions but for nonstoichiometric SiC the Ti, V(Ni), and Cr atoms may also occupy the interstitial, Si, and C sites, respectively. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Transaction cost‐enhanced entry mode choices and firm performance
Authors: Brouthers Keith D. , Brouthers Lance Eliot , Werner Steve 
Published: November 2003

AbstractAccording to transaction cost theory, firms select the international mode of entry that provides the most efficient form of governance. However, previous scholarship largely neglects the impact of transaction cost variables on entry mode choice and firm performance. In this study, we add transaction cost variables to a set of variables previously used to predict firm mode choice and performance. We theorize and find that firms selecting these ‘transaction cost‐enhanced international entry modes’ perform better than firms using other modes of entry. Based on our results, we conclude that ‘enhanced’ transaction cost theory appears to be normative as well as descriptive with respect to international entry mode decisions. Copyright © 2003 John Wiley & Sons, Ltd.
Industrial dynamics and managerial networking in an emerging market: the case of China
Authors: Luo Yadong 
Published: November 2003

AbstractThis study examines how industrial conditions influence the level of executives' managerial networking with decision‐makers in other entities such as buyers, suppliers, competitors, distributors, and regulators in an emerging market. Corroborating a view that social capital holds contingent value, we theorize that executives facing different industrial conditions have different levels of commitment to exploiting interpersonal ties for fulfilling organizational needs. We propose that managerial networking is influenced by exogenous industrial attributes such as structural uncertainty, sales growth, regulatory stringency, competitive pressure, and production capacity utilization. Our analysis of executives in 364 firms in China demonstrates that the level of managerial networking increases when uncertainty, regulation, and competition increase and production capacity utilization decreases. For a specific firm, the link between industrial dynamics and managerial networking is moderated by its strategic proactiveness. Copyright © 2003 John Wiley & Sons, Ltd.
Oral glucosamine and the management of feline idiopathic cystitis
Authors: Gunn-Moore D.A. , Shenoy C.M. 
Published: November 2003

Oral glucosamine was compared to a placebo for the management of cats with feline idiopathic cystitis (FIC) in a randomised, double-blinded, placebo-controlled, study. Forty cats with a history of recurrent cystitis due to FIC were divided into two groups and treated daily per os with either 125 mg N-acetyl glucosamine or a placebo for six months. Owners graded their cats' clinical signs at the beginning and end of the study, and kept daily diaries documenting signs of cystitis using visual analogue scales. Further episodes of cystitis were seen in 26 (65%) of the cats during the study. Affected cats experienced a mean of five recurrences (range 1–19) with each recurrence lasting a mean of four days (range 1–64 days). There were no significant differences between the two groups when considering the owners assessments of the mean health score ( P > 0.5), the average monthly clinical score ( P = 0.22) or the average number of days with clinical signs ( P = 0.28). Two cats suffered from such severe recurrent urethral obstruction that they were euthanased; they were both in the placebo group. Compared to the start of the study the majority of cats in both groups improved significantly ( P < 0.001) (mean health score of each group at the start was 0.5 ± SD 0.5, compared to glucosamine 4.4 ± 0.7 and placebo 3.9 ± 1.6 at the end). This is believed to have occurred because the owners of 36 of the 40 cats (90%) started feeding more canned cat food. The urine specific gravity at the start of the trial was significantly higher (mean 1.050 ± SD 1.007) than when reassessed one month later (1.036 ± 1.010, P < 0.01).
D‐Ribose improves diastolic function and quality of life in congestive heart failure patients: a prospective feasibility study
Authors: Omran Heyder , Illien Stefan , MacCarter Dean , St. Cyr John , Lüderitz Berndt 
Published: November 2003

AbstractPatients with chronic coronary heart disease often suffer from congestive heart failure (CHF) despite multiple drug therapies. D‐Ribose has been shown in animal models to improve cardiac energy metabolism and function following ischaemia. This was a prospective, double blind, randomized, crossover design study, to assess the effect of oral D‐ribose supplementation on cardiac hemodynamics and quality of life in 15 patients with chronic coronary artery disease and CHF. The study consisted of two treatment periods of 3 weeks, during which either oral D‐ribose or placebo was administered followed by a 1‐week wash out period, and then administration of the other supplement. Assessment of myocardial functional parameters by echocardiography, quality of life using the SF‐36 questionnaire and functional capacity using cycle ergometer testing was performed. The administration of D‐ribose resulted in an enhancement of atrial contribution to left ventricular filling (40±11 vs. 45±9%, P=0.02), a smaller left atrial dimension (54±20 vs. 47±18 ml, P=0.02) and a shortened E wave deceleration (235±64 vs. 196±42, P=0.002) by echocardiography. Further, D‐ribose also demonstrated a significant improvement of the patient's quality of life (417±118 vs. 467±128, P≤0.01). In comparison, placebo did not result in any significant echocardiographic changes or in quality of life. This feasibility study in patients with coronary artery disease in CHF revealed the beneficial effects of D‐ribose by improving diastolic functional parameters and enhancing quality of life.