bluuebunny/crossref_metadata_2025_split huggingface dataset:
Difluoromethylornithine stimulates early cardiac commitment of mesenchymal stem cells in a model of mixed culture with cardiomyocytes
Authors: Muscari Claudio , Bonafé Francesca , Carboni Marco , Govoni Marco , Stanic Ivana , Gamberini Chiara , Ricci Francesca , Tazzari Pier Luigi , Caldarera Claudio Marcello , Guarnieri Carlo 
Published: January 2008

AbstractThe efficiency of in vitro mesenchymal stem cell (MSC) differentiation into the myocardial lineage is generally poor. In order to improve cardiac commitment, bone marrow GFP+MSCs obtained from transgenic rats were cultured with adult wild type rat cardiomyocytes for 5 days in the presence of difluoromethylornithine (DFMO), an inhibitor of polyamine synthesis and cell proliferation. The percentage of GFP+MSCs showing cardiac myofibril proteins (cMLC2, cTnI) was about threefold higher after DFMO addition (3%) relative to the untreated control (1%). Another set of experiments was performed with cardiomyocytes incubated for 1 day in the absence of glucose and serum and under hypoxic conditions (pO2 < 1%), in order to simulate severe ischemia. The percentage of cardiac committed GFP+MSCs was about 5% when cultured with the hypoxic/starved cardiomyocytes and further increased to 7% after DFMO addition. The contemporary presence of putrescine in DFMO‐treated cells markedly blunted differentiation, while the cytostatic mitomycin C was not able to induce cardiac commitment. The involvement of histone acetylation in DFMO‐induced differentiation was evidenced by the strong attenuation of cardiac commitment exerted by anacardic acid, an inhibitor of histone acetylase. Moreover, the percentage of acetylated histone H3 significantly increased in bone marrow MSCs obtained from wild type rats and treated with DFMO. These results suggest that polyamine depletion can represent a useful strategy to improve MSC differentiation into the cardiac lineage, especially in the presence of cardiomyocytes damaged by an ischemic environment. J. Cell. Biochem. 103: 1046–1052, 2008. © 2008 Wiley‐Liss, Inc.
Stabilization mechanisms of organic matter in four temperate soils: Development and application of a conceptual model
Authors: von Lützow Margit , Kögel‐Knabner Ingrid , Ludwig Bernard , Matzner Egbert , Flessa Heinz , Ekschmitt Klemens , Guggenberger Georg , Marschner Bernd , Kalbitz Karsten 
Published: January 2008

AbstractBased on recent findings in the literature, we developed a process‐oriented conceptual model that integrates all three process groups of organic matter (OM) stabilization in soils namely (1) selective preservation of recalcitrant compounds, (2) spatial inaccessibility to decomposer organisms, and (3) interactions of OM with minerals and metal ions. The model concept relates the diverse stabilization mechanisms to active, intermediate, and passive pools. The formation of the passive pool is regarded as hierarchical structured co‐action of various processes that are active under specific pedogenetic conditions.To evaluate the model, we used data of pool sizes and turnover times of soil OM fractions from horizons of two acid forest and two agricultural soils. Selective preservation of recalcitrant compounds is relevant in the active pool and particularly in soil horizons with high C contents. Biogenic aggregation preserves OM in the intermediate pool and is limited to topsoil horizons. Spatial inaccessibility due to the occlusion of OM in clay microstructures and due to the formation of hydrophobic surfaces stabilizes OM in the passive pool. If present, charcoal contributes to the passive pool mainly in topsoil horizons. The importance of organo‐mineral interactions for OM stabilization in the passive pool is well‐known and increases with soil depth. Hydrophobicity is particularly relevant in acid soils and in soils with considerable inputs of charcoal. We conclude that the stabilization potentials of soils are site‐ and horizon‐specific. Furthermore, management affects key stabilization mechanisms. Tillage increases the importance of organo‐mineral interactions for OM stabilization, and in Ap horizons with high microbial activity and C turnover, organo‐mineral interactions can contribute to OM stabilization in the intermediate pool. The application of our model showed that we need a better understanding of processes causing spatial inaccessibility of OM to decomposers in the passive pool.
Organo‐mineral associations in temperate soils: Integrating biology, mineralogy, and organic matter chemistry
Authors: Kögel‐Knabner Ingrid , Guggenberger Georg , Kleber Markus , Kandeler Ellen , Kalbitz Karsten , Scheu Stefan , Eusterhues Karin , Leinweber Peter 
Published: January 2008

AbstractWe summarize progress with respect to (1) different approaches to isolate, extract, and quantify organo‐mineral compounds from soils, (2) types of mineral surfaces and associated interactions, (3) the distribution and function of soil biota at organo‐mineral surfaces, (4) the distribution and content of organo‐mineral associations, and (5) the factors controlling the turnover of organic matter (OM) in organo‐mineral associations from temperate soils. Physical fractionation achieves a rough separation between plant residues and mineral‐associated OM, which makes density or particle‐size fractionation a useful pretreatment for further differentiation of functional fractions. A part of the OM in organo‐mineral associations resists different chemical treatments, but the data obtained cannot readily be compared among each other, and more research is necessary on the processes underlying resistance to treatments for certain OM components. Studies using physical‐fractionation procedures followed by soil‐microbiological analyses revealed that organo‐mineral associations spatially isolate C sources from soil biota, making quantity and quality of OM in microhabitats an important factor controlling community composition. The distribution and activity of soil microorganisms at organo‐mineral surfaces can additionally be modified by faunal activities. Composition of OM in organo‐mineral associations is highly variable, with loamy soils having generally a higher contribution of polysaccharides, whereas mineral‐associated OM in sandy soils is often more aliphatic. Though highly reactive towards Fe oxide surfaces, lignin and phenolic components are usually depleted in organo‐mineral associations. Charred OM associated with the mineral surface contributes to a higher aromaticity in heavy fractions. The relative proportion of OC bound in organo‐mineral fractions increases with soil depth. Likewise does the strength of the bonding. Organic molecules sorbed to the mineral surfaces or precipitated by Al are effectively stabilized, indicated by reduced susceptibility towards oxidative attack, higher thermal stability, and lower bioavailability. At higher surface loading, organic C is much better bioavailable, also indicated by little 14C age. In the subsurface horizons of the soils investigated in this study, Fe oxides seem to be the most important sorbents, whereas phyllosilicate surfaces may be comparatively more important in topsoils. Specific surface area of soil minerals is not always a good predictor for C‐stabilization potentials because surface coverage is discontinuous. Recalcitrance and accessibility/aggregation seem to determine the turnover dynamics in fast and intermediate cycling OM pools, but for long‐term OC preservation the interactions with mineral surfaces, and especially with Fe oxide surfaces, are a major control in all soils investigated here.
Comparison of two quantitative soil organic carbon models with a conceptual model using data from an agricultural long‐term experiment
Authors: Ludwig Bernard , Kuka Katrin , Franko Uwe , von Lützow Margit 
Published: January 2008

AbstractQuantitative soil organic carbon (SOC) models are required for a better understanding of C sequestration in soils and for prognoses at different scenarios. However, it is unclear whether the major C‐stabilization mechanisms are included adequately. Objectives were (1) to test the performance of the CIPS (Carbon turnover In Pore Space) model and the Rothamsted Carbon (RothC) Model for a prediction of the SOC dynamics at the long‐term experiments at Halle (Germany) and (2) to compare the model structures of the quantitative models and a conceptual model in order to identify shortcomings of the quantitative models. Both quantitative models had a similar prediction performance: the C dynamics was predicted satisfactorily for the Halle sites under continuous rye with NPK fertilization or without any fertilization (1878–1953), but larger deviations between modeled and measured C contents were observed for the continuous rye and maize in the entire period from 1878 to 1996. The comparison of the conceptual model with the quantitative models revealed that the neglect of the black C dynamics and the interactions of SOC with mineral surfaces are not included explicitly. Site‐specific calibrations are required where these processes have a significant impact on soil organic matter dynamics. Furthermore, the number of pools and mechanisms in the conceptual model is higher than in the quantitative models independent of their level of abstraction. Despite the neglect of some important mechanisms in the quantitative models, it has to be noted that they reproduce the SOC data generally well in agricultural surface soils. Moreover, they need only few inputs which are generally easily obtainable.
Optimisation of the headspace‐solid phase microextraction for organomercury and organotin compound determination in sediment and biota
Authors: Delgado Alejandra , Usobiaga Aresatz , Prieto Ailette , Zuloaga Olatz , de Diego Alberto , Madariaga Juan M. 
Published: January 2008

AbstractHeadspace solid‐phase microextraction was optimised for the simultaneous preconcentration of methylmercury (MeHg+), monobutyltin, dibutyltin, tributyltin, monophenyltin (MPhT), diphenyltin (DPhT), and triphenyltin (TPhT) from sediments and biota. Extraction time (3–24 min), extraction temperature (20–90°C), desorption time (1–10.4 min), desorption temperature (152–260°C), and sample volume (5–22 mL) were simultaneously optimised, while variables such as fibre type (30 μm polydimethylsiloxane, PDMS), pH (acetic acid/sodium acetate, HOAc/NaOAc, 2 mol/L, pH ∼︁ 4.8), the concentration of the derivatisation agent (sodium tetraethylborate, NaBEt4, 0.1% m/v), and the ionic strength (fixed by the buffer solution) were kept constant. The variables were optimised according to the experiments proposed by the MultiSimplex program and the responses were considered in order to establish the optimum conditions. The repeatability (relative standard deviation, RSD, 5–20.6%) and limits of detection (LODs, 0.05–0.97 ng/g) of the overall method were also estimated. The lowest precisions were obtained for DPhT and TPhT. The optimised preconcentration method was applied to the determination of MeHg+, butyl‐ and phenyltins in certified reference materials (IAEA‐405 MeHg+ in estuarine sediment, BCR‐646 butyl‐ and phenyltins in marine sediment, BCR‐463 MeHg+ in tuna fish, DOLT‐2 MeHg+ in dogfish liver, and BCR‐477 butyltins in mussel tissue) by GC with microwave‐induced plasma/atomic‐emission detection.
Id1 delays senescence of primary human melanocytes
Authors: Cummings Staci D. , Ryu Byungwoo , Samuels Michael A. , Yu Xiaobing , Meeker Alan K. , Healey Megan A. , Alani Rhoda M. 
Published: January 2008

AbstractThe Id family of helix‐loop‐helix transcription factors is upregulated in a variety of human malignancies and has been implicated in promoting tumorigenesis through effects on cell growth, differentiation, and tumor angiogenesis. While expression of Id proteins has been associated with tumorigenesis, the precise mechanistic relationship between Id expression and carcinogenesis has not been clearly delineated. We have previously shown that Id1 delays cellular senescence in primary mammalian cells through inhibition of the cell cycle regulatory protein and familial melanoma gene, p16/INK4a. We have also demonstrated that Id1 expression is upregulated in early stage primary human melanomas and may be an important marker for early malignancy. In order to further define the role of Id1 in human melanoma development, we have evaluated the function of Id1 in primary human melanocytes. Here we show that constitutive expression of Id1 in primary human melanocytes leads to delayed cellular senescence and decreased expression of the familial melanoma gene, p16/INK4a. Although melanocytes constitutively expressing Id1 are shown to possess extended lifespans, this is not associated with an appreciable change in cell growth or telomere length. We conclude that Id1 delays cellular senescence in primary human melanocytes through inhibition of p16/INK4a expression and suggest that Id1 may contribute to the malignant conversion of primary human melanocytes through extension of cellular lifespan. © 2008 Wiley‐Liss, Inc.
Numerical estimation of REV and permeability tensor for fractured rock masses by composite element method
Authors: Chen S.‐H. , Feng X.‐M. , Isam S. 
Published: January 2008

AbstractThe Monte Carlo method is used to generate parent stochastic discrete fracture network, from which a series of fractured rock samples of different sizes and orientations are extracted. The fracture network combined with a regular grid forms composite element mesh of the fractured rock sample, in which each composite element is composed of sub‐elements incised by fracture segments. The composite element method (CEM) for the seepage is implemented to obtain the nodal hydraulic potential as well as the seepage flow rates through the fractured rock samples. The application of CEM enables a large quantity of stochastic tests for the fractured rock samples because the pre‐process is facilitated greatly. By changing the sizes and orientations of the samples, the analysis of the seepage characteristics is realized to evaluate the variation of the permeability components, the existence of the permeability tensor and the representative element volume. The feasibility and effectiveness are illustrated in a numerical example. Copyright © 2008 John Wiley & Sons, Ltd.
Application of the interior‐point method to shakedown analysis of pavements
Authors: Nguyen An Danh , Hachemi Abdelkader , Weichert Dieter 
Published: January 2008

AbstractBased on the lower‐bound shakedown theorem by Melan, a method to analyse pavements under cyclic, in particular, rolling contact loading is presented. Repeated sliding/rolling line contact as well as repeated stationary contact is considered. The material is assumed to be rate‐independent elastic–plastic. As yield conditions, the rounded Mohr–Coulomb and von Mises yield criteria are used, assuming associated flow rules. The proposed numerical method is based on finite elements, and the inherent optimization problem to determine the shakedown factors is solved using the interior‐point method. Several numerical results are presented and compared with the existing results in literatures. Copyright © 2008 John Wiley & Sons, Ltd.
Direct optimization of dynamic systems described by differential‐algebraic equations
Authors: Fabien Brian C. 
Published: January 2008

AbstractThis paper presents a method for the optimization of dynamic systems described by index‐1 differential‐algebraic equations (DAE). The class of problems addressed include optimal control problems and parameter identification problems. Here, the controls are parameterized using piecewise constant inputs on a grid in the time interval of interest. In addition, the DAE are approximated using a Rosenbrock–Wanner (ROW) method. In this way the infinite‐dimensional optimal control problem is transformed into a finite‐dimensional nonlinear programming problem (NLP). The NLP is solved using a sequential quadratic programming (QP) technique that minimizes the L∞ exact penalty function, using only strictly convex QP subproblems. This paper shows that the ROW method discretization of the DAE leads to (i) a relatively small NLP problem and (ii) an efficient technique for evaluating the function, constraints and gradients associated with the NLP problem. This paper also investigates a state mesh refinement technique that ensures a sufficiently accurate representation of the optimal state trajectory. Two nontrivial examples are used to illustrate the effectiveness of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.
Influenza‐associated morbidity in children with cancer
Authors: Tasian Sarah K. , Park Julie R. , Martin Emily T. , Englund Janet A. 
Published: January 2008

AbstractBackgroundThe clinical impact of influenza in children undergoing therapy for cancer is not well‐described in the literature.ProcedureLaboratory‐documented influenza infection in pediatric oncology patients cared for in a single regional pediatric medical center between July 2000 and June 2005 was identified by review of medical and laboratory records.ResultsTwenty‐seven clinical encounters were identified in 24 pediatric oncology patients with influenza infection. Eighty‐three percent of patients were receiving chemotherapy for hematologic or solid malignancies. Two‐thirds of patients were hospitalized for a median duration of 7.4 days; 40% of patients experienced a delay in scheduled chemotherapy as result of influenza infection. Most children (67%) were not neutropenic, although 63% were lymphopenic. Importantly, 15% of children with influenza had simultaneously diagnosed bacteremia. Concomitant pathogens included Pseudomonas aeruginosa, Enterobacter cloacae, Enterococcus faecalis, and coagulase‐negative Staphylococcus. Primary influenza pneumonia and/or respiratory failure occurred in three children, and ventilatory support was required in four clinical encounters. Antiviral medications were administered to 63% of patients within 2 days of influenza diagnosis.ConclusionPediatric oncology patients experienced significant influenza‐associated morbidities. Influenza infection should be considered in febrile children with respiratory symptoms during the respiratory viral season, as well as concurrent bacterial or fungal infections. Pediatr Blood Cancer 2008;50:983–987. © 2008 Wiley‐Liss, Inc.
Current awareness: Pharmacoepidemiology and drug safety
Authors:   John Wiley & Sons, Ltd.
Published: January 2008

AbstractIn order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
Identification of target antigens of antiendothelial cell antibodies in healthy individuals: A proteomic approach
Authors: Servettaz Amélie , Guilpain Philippe , Camoin Luc , Mayeux Patrick , Broussard Cédric , Tamby Mathieu C. , Tamas Nicolas , Kaveri Srini V. , Guillevin Loïc , Mouthon Luc 
Published: January 2008

AbstractIn order to identify target antigens of anti‐endothelial cell (anti‐EC) antibodies (AECA) in healthy individuals, we have used a proteomic approach combining 2‐DE and immunoblotting. Whole cell protein extracts obtained from human umbilical vein EC (HUVEC) cultures were used as a source of antigens. Serum IgG from 12 healthy blood donors were tested at a concentration of 200 μg/mL. Targeted spots were identified by MS. The HUVEC proteome was composed of 884 protein spots. Among these, 61 ± 25.8 (mean ± SD) spots were recognized by serum IgG from healthy individuals, with marked differences from one individual to another. Among these spots, 11 were recognized by serum IgG from all healthy individuals tested. These spots corresponded to six different proteins with several spots corresponding to different isoforms of the same protein. Target antigens were: cytoskeletal proteins (β‐actin, α‐tubulin, and vimentin); glycolytic enzymes (glucose‐3‐phosphate‐deshydrogenase and α‐enolase); and prolyl‐4‐hydroxylase β subunit, a member of the disulfide isomerase family. This study shows that the repertoire of IgG AECA is heterogeneous among healthy individuals. IgG from all of the healthy individuals tested recognized a restricted set of highly conserved ubiquitous proteins playing key roles in cell biology and maintenance of homeostasis.
ClpL is essential for induction of thermotolerance and is potentially part of the HrcA regulon in Lactobacillus gasseri
Authors: Suokko Aki , Poutanen Marjo , Savijoki Kirsi , Kalkkinen Nisse , Varmanen Pekka 
Published: January 2008

AbstractStress‐inducible proteins are likely to contribute to the survival and activity of probiotic bacteria during industrial processes and in the gastrointestinal tract. The recently published genome sequence of probiotic Lactobacillus gasseri ATCC 33323 suggests the presence of ClpC, ClpE, ClpL, and ClpX from the Clp ATPase family of stress proteins. The heat‐shock response of L. gasseri was studied using 2‐D DIGE. A total of 20 protein spots showing significant (p<0.05) increase in abundance after 30 min heat‐shock were identified, including DnaK, GroEL, ClpC, ClpE, and ClpL. To study the physiological role of ClpL, one of the most highly induced proteins during heat‐shock, its corresponding gene was inactivated. The ΔclpL mutant strain had growth characteristics that were indistinguishable from wild‐type under several stress conditions. However, in the absence of functional ClpL, L. gasseri exhibited drastically reduced survival at a lethal temperature and was unable to induce thermotolerance. Genome sequences indicate that the expression of clp genes in several Lactobacillus species is regulated by HrcA, instead of CtsR, the conserved clp gene regulator of low G+C Gram‐positive bacteria. Electrophoretic mobility shift assays using L. gasseri HrcA protein and clpL upstream fragments revealed, for the first time, a direct interaction between HrcA and the promoter of a clp gene from a Lactobacillus.
1st Central and Eastern European Proteomic Conference & 3rd Czech Proteomic Conference 29 – 31 October 2007, Prague, Czech Republic
Authors: Gadher Suresh Jivan , Bezouška Karel , Kovářová Hana 
Published: January 2008

AbstractMore than 130 delegates from all over the world attended the 1st Central and Eastern European Proteomic Conference organized together with the 3rd Czech Proteomic Conference in the TOP Hotel, Prague in the Czech Republic from 29th to 31st October, 2007. The autumn nostalgia of the historical city of Prague provided the stage for a fascinating meeting that reviewed rapidly emerging proteomic research in the countries of Central and Eastern Europe, and focused on proteomics driven discovery and applications.