bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cartilage‐derived morphogenetic proteins enhance the osteogenic protein‐1‐induced osteoblastic cell differentiation of C2C12 cells
Authors: Yeh Lee‐Chuan C. , Tsai Alicia D. , Zavala Michelle C. , Lee John C. 
Published: March 2004

AbstractPrevious studies have shown that osteogenic protein‐1 (OP‐1; also known as BMP‐7) induces differentiation of the pluripotent mesenchymal cell line C2C12 into osteoblastic cells. OP‐1 also alters the steady‐state levels of messenger RNA (mRNA) encoding for the cartilage‐derived morphogenetic proteins (CDMPs) in C2C12 cells. In the present study, the effects of exogenous CDMPs on bone cell differentiation induced by OP‐1 in C2C12 cells were examined. Exogenous CDMP‐1, ‐2, and ‐3 synergistically and dose‐dependently enhanced OP‐1 action in stimulating alkaline phosphatase (AP) activity and osteocalcin (OC) mRNA expression. AP staining studies revealed that the combination of OP‐1 and CDMP enhanced OP‐1 action by stimulating those cells that had responded to OP‐1 and not by activating additional cells. The combination did not change the mRNA expression of the BMPs and their receptors. CDMP‐1 enhanced the suppression of the OP‐1‐induced expression of the myogeneic differentiation regulator MyoD. CDMP‐1 and OP‐1 alone stimulated Smad5 protein expression, but the combination of OP‐1 and CDMP‐1 stimulated synergistically Smad5 protein expression. Thus, one mechanism of the observed synergy involved enhancement of the induced Smad5 protein expression. At the same protein concentration, CDMP‐1 is most potent in enhancing OP‐1 activity in inducing osteoblastic cell differentiation of C2C12 cells. CDMP‐3 is about 80% as potent as CDMP‐1, and CDMP‐2 is the least potent (about 50% of CDMP‐1). © 2004 Wiley‐Liss, Inc.
Immunotherapy with autologous tumor cells engineered to secrete Tag7/PGRP, an innate immunity recognition molecule
Authors: Larin Sergey S. , Korobko Elena V. , Kustikova Olga S. , Borodulina Olga R. , Raikhlin Natan T. , Brisgalov Igor P. , Georgiev Georgii P. , Kiselev Sergei L. 
Published: March 2004

AbstractBackgroundRecent studies indicate that the innate component of immune defense plays an important role in the establishment of antigen‐specific immune response. We have previously isolated a novel mouse gene tag7/PGRP that was shown to be involved in the innate component of the immune system, and its insect homologue is an upstream mediator of Toll signaling in Drosophila.MethodsTransiently or stably genetically modified mouse tumor cell lines expressing Tag7 were used. Tumor growth rate and animal survival were analyzed. Possible effector cells involved in tumor suppression were detected immunohistochemically.ResultsTransfection of mammary gland adenocarcinoma cells with the tag7 cDNA did not alter their growth rate in vitro but diminished their tumorogenicity in vivo in syngeneic and immunodeficient animals. Increased incidence of apoptosis was registered in the modified tumors. Transient expression of Tag7 by mouse melanoma M3 cells elicited protective immunity against parental tumor cells. Immunohistochemical analysis revealed that tumors after immunization with the genetically modified cells were infiltrated with Mac1+ cells, B220+ cells, and NK cells. Using nude mice we observed rejection of modified cells, but did not detect memory formation.ConclusionsWe can conclude that secretion of the Tag7 protein by genetically modified cells can induce mobilization of antigen‐presenting cells and innate effectors. Memory mechanisms are mediated by T cell response. For the first time our results demonstrate that local secretion of Tag7—the molecule involved in innate immunity—may play an important role in the induction of effective antitumor response in mice. Copyright © 2004 John Wiley & Sons, Ltd.
Rescue of TNFα‐inhibited neuronal cells by IGF‐1 involves Akt and c‐Jun N‐terminal kinases
Authors: Kenchappa Prashanth , Yadav Ajay , Singh Gurvinder , Nandana Srinivas , Banerjee Kakoli 
Published: March 2004

AbstractProinflammatory cytokines, especially tumor necrosis factor α (TNFα), is a pleiotropic mediator of a diverse array of physiologic and neurologic functions and is upregulated during various inflammatory and neurodegenerative diseases. A common survival response during such situations is the increased expression of the hormone insulin‐like growth factor 1 (IGF‐1). Although it was thought previously that the mechanisms of TNFα and IGF‐1 action were unrelated, it has been shown that low doses of TNFα can inhibit the survival effects of IGF‐1 in mouse cerebellar granule neurons. We used a neuronal cell line SH‐SY5Y, which underwent apoptosis in response to TNFα and this process could be reversed substantially by IGF‐1. Crosstalk between signaling pathways of these two factors was found at various points downstream of their signal transduction. To determine the mechanisms of IGF‐1‐mediated rescue, we looked at the MAP kinases, which are known to be involved in IGF‐1 as well as TNFα signaling. The c‐Jun N‐terminal kinase pathway, which is known normally to promote cell death, was found to actually promote survival of TNFα‐mediated cell death. Inhibiting the c‐Jun survival pathway completely reversed the rescue mediated by IGF‐1. In addition, the Akt pathway played an equally important role in this rescue. © 2004 Wiley‐Liss, Inc.
Redesigning computer call center work: a longitudinal field experiment
Authors: Workman Michael , Bommer William 
Published: March 2004

AbstractComputer technology call centers provide technical assistance to customers via the telephone to solve computer hardware and software problems. The simultaneous demands for technical and customer service skills often place strain on call center employees, frequently producing poor job attitudes. We utilized a field experiment (N = 149) with a randomly assigned pretest–posttest and control group design to compare three interventions' effectiveness on employee job attitudes in a computer technology call center: Intervention 1 focused on aligning organizational structures; Intervention 2 focused on increasing employee involvement in work processes (high‐involvement); and Intervention 3 implemented autonomous work teams.We found that high‐involvement work processes produced the most potent effects on job satisfaction and organizational commitment attitudes, as well as on performance (i.e., improved customer satisfaction scores, increased closed problems, reduced problems escalated, and fewer repeat calls). Further, we found that group work preference moderated the results between the group‐oriented interventions and employees' job satisfaction. Under high involvement and in autonomous work teams, high preferences for group work resulted in greater job satisfaction than when employees had lower preferences for group work. However, preferences for group work were not associated with increased organizational commitment in either intervention. Copyright © 2004 John Wiley & Sons, Ltd.
Evaluation of pedotransfer functions predicting hydraulic properties of soils and deeper sediments
Authors: Wagner Bernhard , Tarnawski Vlodek R. , Stöckl Michael 
Published: March 2004

AbstractEight pedotransfer functions (PTF) originally calibrated to soil data are used for evaluation of hydraulic properties of soils and deeper sediments. Only PTFs are considered which had shown good results in previous investigations. Two data sets were used for this purpose: a data set of measured pressure heads vs. water contents of 347 soil horizons (802 measured pairs) from Bavaria (Southern Germany) and a data set of 39 undisturbed samples of tertiary sediments from deeper ground (down to 100 m depth) in the molasse basin north of the Alps, containing 840 measured water contents vs. pressure head and unsaturated hydraulic conductivity. A statistical analysis of the PTFs shows that their performance is quite similar with respect to predicting soil water contents. Less satisfactory results were obtained when the PTFs were applied to prediction of water content of sediments from deeper ground. The predicted unsaturated hydraulic conductivities show about the same uncertainty as for soils in a previous study. Systematic deviations of predicted values indicate that an adaptation of the PTFs to the specific conditions of deeper ground should be possible in order to improve predictions.
Variability of CO2 and N2O emissions during freeze‐thaw cycles: results of model experiments on undisturbed forest‐soil cores
Authors: Teepe Robert , Ludwig Bernard 
Published: March 2004

AbstractThe amounts of N2O released in periods of alternate freezing and thawing depend on site and freezing conditions, and contribute considerably to the annual N2O emissions. However, quantitative information on the N2O emission level of forest soils in freeze‐thaw cycles is scarce, especially with regard to the direct and indirect effect of tree species and the duration of freezing. Our objectives were (i) to quantify the CO2 and N2O emissions of three soils under beech which differed in their texture, C and N contents, and humus types in freeze‐thaw cycles, and (ii) to study the effects of the tree species (beech (Fagus sylvatica L.) and spruce (Picea abies (L.) Karst.)) for silty soils from two adjacent sites and the duration of freezing (three and eleven days) on the emissions. Soils were adjusted to a matric potential of –0.5 kPa, and emissions were measured in 3‐hr intervals for 33 days. CO2 emissions of all soils were similar in the two freeze‐thaw cycles, and followed the temperature course. In contrast, the N2O emissions during thawing differed considerably. Large N2O emissions were found on the loamy soil under beech (Loam‐beech) with a maximum N2O emission of 1200 μg N m–2 h–1 and a cumulative emission of 0.15 g N m–2 in the two thawing periods. However, the sandy soil under beech (Sand‐beech) emitted only 1 mg N2O‐N m–2 in the two thawing periods probably because of a low water‐filled pore space of 44 %. The N2O emissions of the silty soil under beech (Silt‐beech) were small (9 mg N m–2 in the two thawing periods) with a maximum emission of 150 μg N m–2 h–1 while insignificant N2O emissions were found on the silty soil under spruce (0.2 mg N m–2 in the two thawing periods). The cumulative N2O emissions of the short freeze‐thaw cycles were 17 % (Sand‐beech) or 22 % (Loam‐beech, Silt‐beech) less than those of the long freeze‐thaw cycles, but the differences between the emissions of the two periods were not significant (P ≤ 0.05). The results of the study show that the amounts of N2O emitted in freeze‐thaw cycles vary markedly among different forest soils and that the tree species influence the N2O thawing emissions in forests considerably due to direct and indirect impacts on soil physical and chemical properties, soil structure, and properties of the humus layer.
Miniaturised sample preparation of fatty foodstuffs for the determination of polychlorinated biphenyls
Authors: Ramos Juan‐José , González M.‐José , Ramos Lourdes 
Published: March 2004

AbstractA miniaturised analytical method allowing the exhaustive extraction of environmentally relevant polychlorinated biphenyls (PCBs) from fatty foodstuffs and the purification of the extracts in a single step has been developed. After dispersion of the freeze dried sample on silica modified with 44% (w/w) of sulphuric acid, the mixture was packed in a glass column on top of a multilayer silica column used for removal of the lipids and biogenic co‐extracted material. Using this arrangement, a complete sample preparation can be accomplished by two successive 10 min static extractions with hexane followed by a brief dynamic step to ensure purging of the sample and sorbents. The analytical method showed a satisfactory performance, with recoveries of the endogenous PCBs studied in the 81–134% range of those found using a more conventional off‐line procedure, even though as small an amount of sample as 0.1 g was used. Detection limits by gas chromatography with micro‐electron capture detection (GC–ECD) were in all cases lower than 0.3 ng/g sample (freeze dried basis) and the repeatability of the complete analytical procedure better than 14% (except for PCB 167). When combined with GC and ion trap detection in the tandem mass spectrometry mode, the miniaturised method has been proved to be a valuable alternative to the more expensive high resolution mass spectrometry for fast screening of PCBs 77, 126, and 169, even if these congeners were not isolated from the bulk of PCBs.
Sample preparation followed by HPLC under harmless 100% aqueous conditions for determination of oxytetracycline in milk and eggs
Authors: Furusawa Naoto 
Published: March 2004

AbstractA simple and hazardous chemical‐free method for the high‐performance liquid chromatographic determination of oxytetracycline (OTC) residues in milk and eggs has been developed. Sample preparation consists in homogenization with an aqueous solution by means of a handheld ultrasonic homogenizer followed by centrifugal ultrafiltration. HPLC is performed with an isocratic aqueous mobile phase and a photo‐diode array detector. Average recoveries of OTC (0.05, 0.1, and 0.2 μg mL–1 for milk; 0.1, 0.2, and 0.4 μg mL–1 for eggs) were ≥ 84% with relative standard deviations of ≤ 2.3%. The total time required for the analysis of one sample and LOQs were < 30 min and < 0.1 μg mL–1, respectively. In all the processes, no organic solvents or hazardous reagents were used.
Separation and determination of active components in Radix Salviae miltiorrhizae and its medicinal preparations by nonaqueous capillary electrophoresis
Authors: Chen An Jia , Zhang Ji You , Li Cun Hong , Chen Xiao Feng , Hu Zhi De , Chen Xing Guo 
Published: March 2004

AbstractA nonaqueous capillary electrophoresis (NACE) method was developed for simultaneous assay of three bioactive components (1: cryptotanshinone; 2: tanshinone IIA, and 3: tanshinone I) in Radix Salviae miltiorrhizae and in its herbal preparations for the first time. After optimization of separation conditions, a buffer of 250 mmol L–1 ammonium acetate containing 30% acetonitrile and 1.0% acetic acid (V : V) in methanol was selected for separating the three analytes, but baseline separation of tanshinon I and tanshinone IIA was not obtained. Therefore second‐order derivative electropherograms were applied for resolving overlapping peaks. Regression equations revealed good linear relationships (correlation coefficients 0.9943–0.9991) between peak heights in second‐order derivative electropherograms and concentrations of the three analytes. The relative standard deviations (RSD) of the migration times and the peak height of the three constituents were in the range of 0.81–0.88% and 0.34–1.13% (intra‐day), 1.57–1.86% and 3.05–5.52% (inter‐day), respectively. The recoveries of three constituents ranged from 90.2 to 108.5%. The results indicated that baseline separation of the analytes was sometimes hard to obtain and second‐order derivative electropherograms were applicable for the resolving and analysis of overlapping peaks.
Prenatal diagnosis of an extra der(4) resulting from a complex maternal chromosome translocation
Authors: Migliori Maria Valeria , Pettinari Antonella , Ciaschini Anna Maria , Piermattei Paola , Pigliapoco Francesco , Discepoli Giancarlo 
Published: March 2004

AbstractWe report the prenatal diagnosis of an extra der(4) resulting from 4:2 malsegregation of a maternal balanced complex translocation involving chromosomes 4, 10, and 11. The woman was referred for amniocentesis because of recurrent miscarriages. Fluorescence in situ hybridization was performed in order to characterize the complex chromosome rearrangement. Following genetic counselling, the couple decided to terminate the pregnancy. Copyright © 2004 John Wiley & Sons, Ltd.
Molecular screening of the ZFHX1B gene in prenatally diagnosed isolated agenesis of the corpus callosum
Authors: Espinosa‐Parrilla Yolanda , Encha‐Razavi Férechté , Attié‐Bitach Tania , Martinovic Jelena , Morichon‐Delvallez Nicole , Munnich Arnold , Vekemans Michel , Lyonnet Stanislas , Amiel Jeanne 
Published: March 2004

AbstractObjectiveAgenesis of the corpus callosum (ACC) is the most common malformation of the central nervous system and may be associated with mental retardation. ACC is found in 40% of the cases of Mowat–Wilson syndrome (MWS), a polytopic embryonic defect including a distinctive facial gestalt, severe mental retardation, epilepsy and postnatal microcephaly as constant features. Other manifestations involve Hirschsprung disease, cardiac defects, renal abnormalities and hypospadias. Among this broad spectrum of malformations recently associated with haploinsufficiency of the zinc finger homeobox 1B gene (ZFHX1B), ACC can therefore be the only feature to be detected prenatally. Thus, we studied a group of 18 fetuses terminated for ACC and performed mutational analysis of the ZFHX1B gene in six selected cases.MethodsDiagnosis of agenesis of the ACC was performed by prenatal echography survey. Screening for ZFHX1B deletions was performed by poly (CA) microsatellite markers studies and real‐time semi‐quantitative PCR. Mutational analysis was performed by single‐strand conformation polymorphisms analysis (SSCP).ResultsNeither deletion encompassing the ZFHX1B locus nor mutation could be detected in any of the six fetuses analysed.ConclusionZFHX1B is not a major gene in isolated ACC. However, analysis of MWS should be considered in the differential diagnosis of ACC, especially when the facial features raise the possibility of MWS. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallization and orientation development in fiber and film processing of polypropylenes of varying stereoregular form and tacticity
Authors: Choi Dongman , White James L. 
Published: March 2004

AbstractWe investigated the crystallization and orientation development in melt spinning and tubular blown film extrusion of several different types of polypropylenes, including conventional high tacticity isotactic polypropylenes (iPP) and metallocene catalyst low tacticity iPPs and syndiotactic polypropylenes (sPP). The fiber and film samples were characterized by wide‐angle X‐ray diffraction (WAXD), birefringence and differential scanning calorimetry (DSC). In melt spinning iPP, we found that the mesomorphic structure of iPP is more readily formed in lower tacticity fibers, and significant amounts of hexagonal β‐form crystals are found in low tacticity iPP fibers spun at high draw‐down ratios. Low tacticity iPP fibers exhibited a significant decrease in the crystalline chain‐axis orientation at high draw‐down ratios, resulting from increased epitaxially branched lamellae. Melt‐spun sPP fibers exhibit Form I helical structure at low spinning speeds and Form III zigzag all trans structure at high spinning speeds. We found that the level of spinline stress is the governing factor for this structural change. Melt‐spun sPP fibers exhibit much higher chain‐axis (c‐axis) orientation factors (fc) and lower birefringence than iPP fibers spun at the same spinline stresses. In tubular blown sPP films, the a‐axis of Form I unit cell tends to orient perpendicular to the film surface, while the b‐axis of monoclinic α unit cell does so in iPP blown films.
Characterization of polyethylene terephthalate films drawn in hot water
Authors: Zumailan A. , Dargent E. , Saiter J. M. 
Published: March 2004

AbstractSorbed water molecules in PET (around 1% in mass) lead to classic plasticizing effects, basically evidenced by a decrease of the glass transition (Tg) and of the cold crystallisation (Tc) temperatures with increasing water content. During drawing of dry PET film and depending on the draw ratio, the initial amorphous phase is oriented at first, then a strain‐induced crystallisation appears. This work deals with the conjugate effects of drawing and water sorption in PET films drawn in hot water. Differential scanning calorimetry and birefringence measurements shown that drawing performed in hot water leads to modifications of Tg and Tc without modification of the degree of crystallinity. Moreover, the formation of water clusters is observed when the strain‐induced crystalline phase occurs.
Blends, hydrogen bonds, and orientation: Understanding the role of interactions
Authors: Brisson Josée 
Published: March 2004

AbstractA review of past and present studies on orientation, rheology, and FTIR investigations on a hydrogen bond–forming polymer, poly(vinyl phenol) (PVPh), and its blends with polyethylene oxide (PEO), poly(methyl methacrylate) (PMMA), and poly(vinyl methyl ether) (PVME) is presented. Orientation is analyzed on the basis of deformation‐induced orientation and relaxation. For deformation, it is proposed from recent molecular modeling studies that orientation is similar for flexible backbone polymers of the types studied. To investigate relaxation, dynamical rheology analysis was performed previously on PVPh/PEO blends and global molecular weight between entanglement, Me, and chain friction ζ were estimated. Me remained close to that of the polymer forming the dominant network, a discontinuity being observed near 50 mole percent. Friction coefficient exhibited a maximum near that of the orientation function of this system. Near‐infrared measurements also showed a maximum in the number of interchain hydrogen bonds at this concentration, although broader than that of orientation or of the friction coefficient. For strongly interacting blends, it is proposed that a break in orientation behavior would be associated with the dominant network present, and therefore to Me, whereas ζ will dictate whether orientation decreases or increases in a given network domain.
Dynamics and criteria for bubble instabilities in a single layer film blowing extrusion
Authors: Kim Seungoh , Fang Yunli , Lafleur Pierre G. , Carreau Pierre J. 
Published: March 2004

AbstractIn this paper, the performance of a new in‐line scanning camera system for the study of various bubble instabilities in film blowing extrusion is critically evaluated. Three commercial film‐grade polyethylenes, LmPE, LLDPE and LDPE, were used to generate the bubble instabilities. Reliable and objective criteria for differentiating various bubble instabilities such as draw resonance, helicoidal instability, and frost line height instability are proposed by using the new device. Detailed dynamics of each bubble instability was carefully investigated as a function of time in a broad range of the take‐up ratio (TUR), blow‐up ratio (BUR) and frost line height (FLH). In addition, effects of melt temperature and mass flow rates on dynamics of the bubble instabilities are discussed. It was found that the new system could capture the main characteristics of all bubble instabilities quantitatively. It was also found that magnitude and periodicity of radius variation during draw resonance of LmPE decreased as TUR increased at constant FLH and BUR. This implies that the origin of draw resonance in film blowing seems to be different from that observed in fiber spinning. In the case of helicoidal instability, eccentricity, which defines the deviation of the bubble center from the die center, decreased as TUR increased. However, the bubble could not be stabilized as expected. A graphical quantification approach to determine the stable zone in the bubble stability map is also discussed.