bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subject classification obtained by cluster analysis and principal component analysis applied to flow cytometric data
Authors: Lugli Enrico , Pinti Marcello , Nasi Milena , Troiano Leonarda , Ferraresi Roberta , Mussi Chiara , Salvioli Gianfranco , Patsekin Valeri , Robinson J. Paul , Durante Caterina , Cocchi Marina , Cossarizza Andrea 
Published: March 2007

AbstractBackground:Polychromatic flow cytometry (PFC) allows the simultaneous determination of multiple antigens in the same cell, resulting in the generation of a high number of subsets. As a consequence, data analysis is the main difficulty with this technology. Here we show the use of cluster analysis (CA) and principal component analyses (PCA) to simplify multicolor data visualization and to allow subjects' classification.Methods:By eight‐colour cytofluorimetric analysis, we investigated the T cell compartment in donors of different age (young, middle‐aged, and centenarians). T cell subsets were identified by combining positive and negative expression of antigens. The resulting data set was organized into a matrix and subjected to CA and PCA.Results:CA clustered people of different ages on the basis of cytofluorimetric profile. PCA of the cellular subsets identified centenarians within a different cluster from young donors, while middle‐aged donors were scattered between these groups. These approaches identified T cell phenotypes that changed with increasing age. In young donors, memory T cell subsets tended to be CD127+ and CD95− whereas CD127−, CD95+ phenotypes were found at higher frequencies in people with advanced age.Conclusions:Our data suggest the use of bioinformatic approaches to analyze large data‐sets generated by PFC and to obtain the rapid identification of key populations that best characterize a group of subjects. © 2007 International Society for Analytical Cytology
Vaccinia virus impairs directional migration and chemokine receptor switch of human dendritic cells
Authors: Humrich Jens Y. , Thumann Peter , Greiner Sebastian , Humrich Jan H. , Averbeck Marco , Schwank Christiane , Kämpgen Eckhart , Schuler Gerold , Jenne Lars 
Published: March 2007

AbstractA crucial event for the induction of an anti‐viral immune response is the coordinated, phenotype‐dependent migration of dendritic cells (DC) to sites of infection and secondary lymphoid organs. Here we show that the vaccinia virus (VV) strains Western Reserve (WR) and modified virus Ankara (MVA) inhibit directional migration of mature DC toward the lymphoid chemokines CCL19 and CXCL12 without affecting surface expression of the respective chemokine receptors or impairing undirected cellular locomotion. Instead, infection with VV results in a deficiency of extracellular signal‐regulated kinase‐1 and a disturbance of intracellular calcium mobilization, indicating a viral interference with signaling events downstream of the surface chemokine receptors. In immature DC, apart from inhibiting chemokine‐induced migration of infected DC, infection with both VV strains increases expression of the inflammatory chemokine receptors CCR1 and CXCR1 on non‐infected bystander DC, which depends on the activity of IFN‐α. Although functional, these chemokine receptors are resistant to lipopolysaccharide‐induced down‐regulation. In addition, VV‐infected and non‐infected bystander DC fail to up‐regulate the lymphoid chemokine receptor CCR7 upon activation, together pointing to a disability to undergo the chemokine receptor switch. This study shows that VV targets directional migration of professional antigen‐presenting cells at multiple functional levels, revealing a potent viral strategy of immune escape.See accompanying commentary: http://dx.doi.org/10.1002/eji.200737215
BAFF and LPS cooperate to induce B cells to become susceptible to CD95/Fas‐mediated cell death
Authors: Acosta‐Rodríguez Eva V. , Craxton Andrew , Hendricks Deborah W. , Merino Maria C. , Montes Carolina L. , Clark Edward A. , Gruppi Adriana 
Published: March 2007

AbstractMicroorganisms with pathogen‐associated molecular patterns (PAMP) activate B cells directly by binding to TLR and also indirectly by inducing APC to release cytokines such as BAFF that promote B cell survival. We found that murine B cells activated concomitantly with LPS (TLR‐4 ligand) and BAFF are protected from spontaneous apoptosis, but are more susceptible to Fas/CD95‐mediated cell death. This increased susceptibility to Fas‐induced apoptosis is associated with a dramatic coordinated up‐regulation of Fas/CD95 and IRF‐4 expression through a mechanism mediated, at least in part, by inhibition of the MEK/ERK pathway. Up‐regulation of Fas/CD95 by BAFF is restricted to B cells activated through TLR‐4, but not through TLR‐9, BCR or CD40. TLR ligands differ in the BAFF family receptors (R) they induce on B cells: BAFF‐R is increased by the TLR4 ligand, LPS, but not by the TLR9 ligand, CpG‐containing oligodeoxynucleotides, which, in contrast, strongly up‐regulates transmembrane activator and CAML interactor (TACI). This suggests the up‐regulation of Fas by BAFF is mediated by BAFF‐R and not by TACI. Consistently, APRIL, which binds to TACI and B cell maturation antigen but not BAFF‐R, did not enhance Fas expression on LPS‐activated B cells. Increased susceptibility to Fas‐mediated killing of B cells activated with LPS and BAFF may be a fail‐safe mechanism to avoid overexpansion of nonspecific or autoreactive B cells.
Expression of a non‐DNA‐binding Ikaros isoform exclusively in B cells leads to autoimmunity but not leukemogenesis
Authors: Wojcik Heather , Griffiths Erin , Staggs Sarah , Hagman James , Winandy Susan 
Published: March 2007

AbstractIkaros is a transcriptional regulator whose function is essential for B cell development. It is expressed in the hematopoietic stem cell (HSC) through the mature B cell stage. Using genetically engineered mice in which the endogenous Ikaros gene is disrupted, it has been shown that a lack of Ikaros leads to a block in B cell development and that its severe diminution results in a hyperresponsive B cell compartment. Ikaros expression within the HSC has led to speculation as to whether the role of Ikaros in B cell biology is largely accomplished prior to B cell specification. In addition, widespread expression of Ikaros in hematopoietic cells leads to the possibility that some or all of the observed defects are not B cell autonomous. In this report, we demonstrate that over‐expression of a dominant interfering Ikaros isoform exclusively in B cells has profound effects on mature B cell function. We provide evidence that continued high‐level expression of Ikaros is essential for homeostasis of peripheral lymphocytes and maintenance of B cell tolerance. We also show that deregulation of Ikaros activity does not rapidly result in B cell leukemogenesis as it does with 100% penetrance within the T cell lineage.
[CuII4] Clusters From the Self‐Assembly of Two Imidazolidinyl 2‐Phenolate‐Bridged [CuII2] Units: The Role of the Chloride Bridge
Authors: Paital Alok Ranjan , Hong Chang Seop , Kim Hyoung Chan , Ray Debashis 
Published: March 2007

AbstractA new family of tetracopper clusters [Cu4(μ4‐X)L2]ClO4·nH2O (1a–c) [X = Cl, Br, I; n = 12, 2, 2; H3L = 2‐(2′‐hydroxyphenyl)‐1,3‐bis[4‐(2‐hydroxyphenyl)‐3‐azabut‐3‐enyl]‐1,3‐imidazolidine] have been synthesised and characterised. The X‐ray crystal structure of 1a reveals that the template action of the spherical Cl– anion (μ4‐Cl–), which features a unique rectangular planar bridging mode, is responsible for the self‐assembly of two [Cu2L]+ units in complex 1a. In this family of complexes the spherical halides serve as templates to assemble the dimeric unit into tetrameric complexes, which gives an insight into the role of the halide bridge in tetranuclear complex formation. The capacity of this bridge to mediate magnetic coupling has been examined by bulk magnetic measurements for complex 1a. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
CuO/ZnO Nanoparticles in a Matrix of Amorphous Silica as High‐Surface Precursors for Methanol Synthesis
Authors: Rohe Bernd , Weiss Rainer , Vukojević Sascha , Baltes Christian , Muhler Martin , Tausch Michael , Epple Matthias 
Published: March 2007

AbstractAn intimate mixture of CuO/ZnO nanocrystals was prepared by an easy sol‐gel synthesis (precipitation in methanol by hydroxide in the presence of a silane). The organic substituents of the silane were almost completely removed by a subsequent photochemical oxidation. The resulting amorphous SiO2 prevented the growth of the catalytically active particles to larger crystals. The coating layer of silica can easily be penetrated by gaseous reactants, as shown by the high specific surface area of about 110–130 m2 g–1 (probably due to both silica and nanocrystalline CuO/ZnO) and the good catalytic activity in methanol synthesis from CO/CO2/H2 synthesis gas (7 to 37 %, compared to an industrial standard methanol catalyst). The ratio of CuO to ZnO can be easily varied by the used preparation method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Repetitive Application of a Fluorous Chiral BINAP–Ru Complex in the Asymmetric Hydrogenation of Olefins
Authors: Horn Joachim , Bannwarth Willi 
Published: March 2007

AbstractA trisperfluoroalkylsilyl‐modified (S)‐BINAP ligand has been prepared and its pertinent Ru complex applied to the asymmetric hydrogenation of olefins. Efficient separation of the Ru catalyst by filtration and its reuse was achieved. Relative to the untagged complex with a Ru‐leaching of 300 ppm, leaching into the product was low (1.6–4.9 ppm). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Decision support for network operation in an open power market
Authors: Warland Geir , Holen Arne T. , Solem Gerd , Uhlen Kjetil , Gimmestad Idar 
Published: March 2007

AbstractThe Norwegian system operator plans to change from (N‐1) to a more flexible cost‐based security criterion. The approach is illustrated using a simple example and then compared with alternative decision paradigms. The comparison shows how different paradigms may change ranking of operating alternatives and that the new cost‐based criterion still tends to favor alternatives close to (N‐1), provided application of a penalty factor giving additional and significant weight on interruption costs. Copyright © 2007 John Wiley & Sons, Ltd.
Improved analytical expressions for the reduction factor of feeding lines consisting of three single‐core cables
Authors: Popović Ljubivoje M. 
Published: March 2007

AbstractThe paper presents an original analytical procedure giving analytical expressions for the determination of ground fault current distribution for a fault located anywhere along a feeding line consisting of three single‐core cables. The derived analytical expressions are mathematically rigorous and take into account all the relevant factors without introducing some larger approximations or idealizations of the real electrical circuit. Correct estimation of ground fault current distribution is necessary in contemporary power engineering practice due to at least two important reasons. One of them is the possibility to a correct estimation of dangerous potential differences, touch and step voltage, which may appear during a ground fault at grounding system of the supplied station. The second reason is the possibility to choose single‐core cables of the feeding cable lines with a metallic sheath cross‐section large enough to withstand thermal strains caused by fault currents. The final result of the use of the analytical expressions derived here is the possibility to determine safe and cost‐effective solutions regarding the grounding systems of the supplied stations and regarding the cross‐sections of the metallic sheaths of single‐core cables. The validation of the derived expressions is verified by experimental measurements. Copyright © 2007 John Wiley & Sons, Ltd.
Geostatistical and multi‐elemental analysis of soils to interpret land‐use history in the Hebrides, Scotland
Authors: Entwistle J.A. , McCaffrey K.J.W. , Dodgshon R.A. 
Published: March 2007

Abstract In the absence of documentary evidence about settlement form and agricultural practice in northwest Scotland before the mid‐18th century, a geoarchaeological approach to reconstructing medieval land use and settlement form is presented here. This study applies multielemental analysis to soils previously collected from a settlement site in the Hebrides and highlights the importance of a detailed knowledge of the local soil environment and the cultural context. Geostatistical methods were used to analyze the spatial variability and distribution of a range of soil properties typically associated with geoarchaeological investigations. Semivariograms were produced to determine the spatial dependence of soil properties, and ordinary kriging was undertaken to produce prediction maps of the spatial distribution of these soil properties and enable interpolation over nonsampled locations in an attempt to more fully elucidate former land‐use activity and settlement patterns. The importance of identifying the spatial covariance of elements and the need for several lines of physical and chemical evidence is highlighted. For many townships in the Hebrides, whose precise location and layout prior to extensive land reorganization in the late 18th–early 19th century is not recoverable through plans, multi‐elemental analysis of soils can offer a valuable prospective and diagnostic tool. © 2007 Wiley Periodicals, Inc.
Genetic model testing and statistical power in population‐based association studies of quantitative traits
Authors: Lettre Guillaume , Lange Christoph , Hirschhorn Joel N. 
Published: March 2007

AbstractThe optimal method for considering different genetic models in association studies is not clear. We compared analytical strategies that use different genetic models to analyze genotype–phenotype information from association studies of quantitative traits in unrelated individuals. We created simulated datasets where the minor alleles are causal with an additive, dominant, or recessive mode of inheritance over a range of allele frequencies. We then computed power to detect these causal alleles using one or a combination of statistical models in a standard regression framework, including corrections for the multiple testing incurred by analyzing multiple models. Our results show that, as expected, maximal power is achieved when we test a single genetic model that matches the actual underlying mode of inheritance of the causal allele. When the inheritance pattern of the causal allele is unknown, the co‐dominant model, a single two degrees of freedom test, has good overall performance in any of the three simple modes of inheritance simulated. Alternatively, it is slightly more powerful to analyze all three genetic models together (additive, dominant, and recessive), but only if the significance thresholds used to correct for analyzing multiple models are appropriately determined (such as by permutation). Finally, a commonly employed approach, testing the additive model alone, performs poorly for recessive causal alleles when the minor allele frequency is not close to 50%. Our observations were confirmed by analyzing an existing genetic association dataset in which we detect the effect of a KCNJ11 variant on insulinogenic index in unrelated non‐diabetic individuals. Genet. Epidemiol. 2007. © 2007 Wiley‐Liss, Inc.
Inhibitory effect of 4‐methylesculetin on hyaluronan synthesis slows the development of human pancreatic cancer in vitro and in nude mice
Authors: Hajime Morohashi , Shuichi Yoshihara , Makoto Nakai , Masanori Yamaguchi , Ikuko Kakizaki , Atsushi Kon , Mutsuo Sasaki , Keiichi Takagaki 
Published: March 2007

AbstractWe report the inhibitory effect of 4‐methylesculetin (ME), a 4‐methylumbelliferone derivative, on hyaluronan (HA) synthesis by pancreatic cancer cells, and its resulting anticancer action. First, HA in cell culture was analyzed using competitive inhibition with hyaluronic acid‐binding protein (HABP) to study HA synthesis by the human pancreatic cancer cell line KP1‐NK, and cell‐surface HA was visualized using a particle‐exclusion assay to study the synthesis of extracellular matrix HA. We also analyzed the inhibitory effect of ME on cell adhesion and invasion, which play a role in the invasion, growth and metastasis of human pancreatic cancer. Furthermore, we examined HA in human pancreatic cancer cells transplanted into the hypodermis of nude mice to study the inhibitory effect of ME on HA synthesis. Moreover, pancreatic cancer cells were also transplanted into the abdomen of nude mice to study whether ME would have the potential to prolong the survival of patients with end‐stage pancreatic cancer. ME at 10 μM did not inhibit the growth of human pancreatic cancer cells, but inhibited HA synthesis in cell culture by 40%, adhesion by 44% and invasion by 40%. ME inhibited the proliferation of subcutaneous tumors and HA synthesis (by 50%) of pancreatic cancer transplanted into the hypodermis of nude mice. ME also prolonged the survival time of nude mice bearing abdominally transplanted pancreatic cancer cells. ME inhibited pancreatic cancer growth and metastasis by inhibition of HA synthesis. These results suggest that ME may prolong the survival time of patients with end‐stage pancreatic cancer. © 2007 Wiley‐Liss, Inc.
Potential for treatment of liposarcomas with the MDM2 antagonist Nutlin‐3A
Authors: Müller Christoph R. , Paulsen Erik B. , Noordhuis Paul , Pedeutour Florence , Sæter Gunnar , Ola Myklebost  
Published: March 2007

AbstractThe MDM2‐antagonist Nutlin 3A can efficiently induce apoptosis in osteosarcoma cell lines with amplified MDM2. However, Nutlin‐based therapy could be even more important in more common sarcoma types where this aberration is frequent. The well‐ and de‐differentiated liposarcomas have complex marker chromosomes, consistently including multiple copies of the MDM2 locus. Since amplification seems to be a primary aberration in these tumors, whereas amplification in osteosarcoma generally is a progression marker, the underlying biological mechanisms may be different. We have therefore investigated the molecular response to Nutlin treatment in several liposarcoma cell lines with such markers, as well as a panel of other sarcoma cell lines. We report that Nutlin efficiently stabilized p53 and induced downstream p53 dependent transcription and apoptosis in liposarcoma cells with amplified MDM2 in vitro. Some effect of Nutlin was also observed on cell lines without amplified MDM2 but with wt TP53, but no apoptosis was induced. The MDM4 protein, reported to interfere with the reactivation of p53, was undetectable in cells with amplified MDM2. Thus, Nutlin represents a promising new therapeutic principle for the treatment of an increasing group of sarcomas. © 2007 Wiley‐Liss, Inc.
Six‐month natural history of oral versus cervical human papillomavirus infection
Authors: D'Souza Gypsyamber , Fakhry Carole , Sugar Elizabeth A. , Seaberg Eric C. , Weber Kathleen , Minkoff Howard L. , Anastos Kathryn , Palefsky Joel M. , Gillison Maura L. 
Published: March 2007

AbstractHuman papillomavirus (HPV) infection is etiologically associated with a subset of oral cancers, and yet, the natural history of oral HPV infection remains unexplored. The feasibility of studying oral HPV natural history was evaluated by collecting oral rinse samples on 2 occasions at a 6‐month interval from 136 HIV‐positive and 63 HIV‐negative participants. Cervical vaginal lavage samples were concurrently collected for comparison. HPV genomic DNA was detected in oral and cervical samples by consensus primer PCR and type‐specified for 37 HPV types. The six‐month cumulative prevalence of oral HPV infection was significantly less than for cervical infection (p < 0.0001). HIV‐positive women were more likely than HIV‐negative women to have an oral (33 vs. 15%, p = 0.016) or cervical (78 vs. 51%, p < 0.001) infection detected. Oral HPV infections detected at baseline were as likely as cervical infections to persist to 6 months among HIV‐negative (60% vs. 51%, p = 0.70) and HIV‐positive (55% vs. 63%, p = 0.27) women. Factors that independently elevated odds for oral HPV persistence differed from cervical infection and included current smoking (OR = 8, 95% CI = 1.3–53), age above 44 years (OR = 20, 95% CI = 4.1–83), CD4 < 500 (OR = 6, 95% CI = 1.1–26), use of HAART therapy (OR = 12, 95% CI = 1.0–156), and time on HAART therapy (trend p = 0.04). The rate of oral HPV infections newly detected at follow‐up was significantly lower than cervical infection among HIV‐positive (p < 0.001) and HIV‐negative women (p < 0.001). Our study not only demonstrates that it is feasible to study the natural history of oral HPV infection with oral rinse sampling, but also indicates that oral and cervical HPV natural history may differ. © 2007 Wiley‐Liss, Inc.
Physical activity and risk of endometrial cancer: The European prospective investigation into cancer and nutrition
Authors: Friedenreich Christine , Cust Anne , Lahmann Petra H. , Steindorf Karen , Boutron‐Ruault Marie‐Christine , Clavel‐Chapelon Françoise , Mesrine Sylvie , Linseisen Jakob , Rohrmann Sabine , Pischon Tobias , Schulz Mandy , Tjønneland Anne , Johnsen Nina Fons , Overvad Kim , Mendez Michelle , Arguelles M.V. , Garcia Carmen Martinez , Larrañaga Nerea , Chirlaque María‐Dolores , Ardanaz Eva , Bingham Sheila , Khaw Kay‐Tee , Allen Naomi , Key Tim , Trichopoulou Antonia , Dilis Vardis , Trichopoulos Dimitrios , Pala Valeria , Palli Domenico , Tumino Rosario , Panico Salvatore , Vineis Paolo , Bueno‐de‐Mesquita H. Bas , Peeters Petra H.M. , Monninkhof Evelyn , Berglund Göran , Manjer Jonas , Slimani Nadia , Ferrari Pietro , Kaaks Rudolf , Riboli Elio 
Published: March 2007

AbstractThe etiologic role of physical activity in endometrial cancer risk remains unclear given the few epidemiologic studies that have been conducted. To investigate this relation more fully, an analysis was undertaken in the European prospective investigation into cancer and nutrition (EPIC). During an average 6.6 years of follow‐up, 689 incident endometrial cancer cases were identified from an analytic cohort within EPIC of 253,023 women. Cox proportional hazards models were used to estimate the associations between type of activity (total, occupational, household, recreational) and endometrial cancer risk. For total activity, women in the highest compared with the lowest quartile of activity had a risk of 0.88 (95% confidence interval (95% CI = 0.61–1.27). No clear associations between each type of activity and endometrial cancer risk were found for the total study population combined. Associations were more evident in the stratified results, with premenopausal women who were active versus inactive experiencing a risk of 0.66 (95% CI = 0.38–1.14) overall. Among premenopausal women, for household and recreational activities the risk estimates in the highest as compared with the lowest quartiles were, respectively, 0.48 (95% CI = 0.23–0.99) and 0.78 (95% CI = 0.44–1.39). No effect modification by body mass index, hormone replacement therapy, oral contraceptive use or energy intake was found. This study provides no evidence of a protective effect of increased physical activity in endometrial cancer risk in all women but some support for a benefit among premenopausal women. The relative risk reductions are most apparent for household activities. © 2007 Wiley‐Liss, Inc.