bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maturation of dendritic cells abrogates C1q production in vivo and in vitro
Authors: Castellano Giuseppe , Woltman Andrea M. , Nauta Alma J. , Roos Anja , Trouw Leendert A. , Seelen Marc A. , Schena Francesco Paolo , Daha Mohamed R. , van Kooten Cees 
Published: January 2004

AbstractDendritic cells (DCs) and complement are essential components of the innate immune system. Immature DCs (immDCs) and mature DCs (mDCs) can migrate to lymphoid areas inducing, respectively, tolerance and immune responses. Primary deficiency of complement component C1q (C1q) leads to autoimmunity, suggesting a role in the maintenance of tolerance. In the present study, we investigated the production of C1q by immDCs, mDCs, and macrophages. We demonstrated that monocyte-derived and CD34+-derived interstitial DCs are a rich source of C1q. C1q produced by immDCs is functionally active in complement activation and binding to apoptotic cells. The production of C1q is completely down-regulated upon DC maturation in vitro. Moreover, we found that DC differentiation in the presence of interferon-α (IFN-α) accelerated DC maturation and strongly impaired overall C1q production. Finally, we demonstrated the presence, in significant numbers, of DC-SIGN+/C1q+ cells in T-cell areas of tonsils, next to DC-LAMP+ mDCs lacking C1q. We conclude from these results that immDC, a cell with tolerogenic properties, is a rich source of active C1q in vitro and in vivo, which is down-regulated on maturation. Therefore, immDCs may be considered an additional source of C1q in humans.
Granulocyte transmigration through the endothelium is regulated by the oxidase activity of vascular adhesion protein-1 (VAP-1)
Authors: Koskinen Kaisa , Vainio Petri J. , Smith David J. , Pihlavisto Marjo , Ylä-Herttuala Seppo , Jalkanen Sirpa , Salmi Marko 
Published: January 2004

AbstractPolymorphonuclear leukocytes (PMNs) migrate from the blood into areas of inflammation by binding to the endothelial cells of blood vessels via adhesion molecules. Vascular adhesion protein-1 (VAP-1) is one of the molecules mediating leukocyte-endothelial cell interactions. It is also an endothelial cell-surface enzyme (amine oxidase) that produces reactive oxygen species during the catalytic reaction. To study the role of the enzymatic activity of VAP-1 in PMN extravasation, we used an enzymatically inactive VAP-1 mutant, specific amine oxidase inhibitors (including a novel small molecule compound), and anti-VAP-1 antibodies in several flow-dependent models. The enzyme inhibitors diminished PMN rolling on and transmigration through human endothelial cells under conditions of laminar shear stress in vitro. Notably, the enzyme inactivating point mutation abolished the capacity of VAP-1 to mediate transmigration. Moreover, the new VAP-1 inhibitor effectively prevented the extravasation of PMNs in an animal model of inflammation. These data show that the oxidase activity of VAP-1 controls PMN exit from the blood during the relatively poorly understood transmigration step. (Blood. 2004;103:3388-3395)
Lyn tyrosine kinase regulates thrombopoietin-induced proliferation of hematopoietic cell lines and primary megakaryocytic progenitors
Authors: Lannutti Brian J. , Drachman Jonathan G. 
Published: January 2004

AbstractIn this study we demonstrate that thrombopoietin (TPO)–stimulated Src family kinases (SFKs) inhibit cellular proliferation and megakaryocyte differentiation. Using the Src kinase inhibitors pyrolopyrimidine 1 and 2 (PP1, PP2), we show that TPO-dependent proliferation of BaF3/Mpl cells was enhanced at concentrations that are specific for SFKs. Similarly, proliferation is increased after introducing a dominant-negative form of Lyn into BaF3/Mpl cells. Murine marrow cells from Lyn-deficient mice or wild-type mice cultured in the presence of the Src inhibitor, PP1, yielded a greater number of mature megakaryocytes and increased nuclear ploidy. Truncation and targeted mutation of the Mpl cytoplasmic domain indicate that Y112 is critical for Lyn activation. Examining the molecular mechanism for this antiproliferative effect, we determined that SFK inhibitors did not affect tyrosine phosphorylation of Janus kinase 2 (JAK2), Shc, signal transducer and activator of transcription (STAT)5, or STAT3. In contrast, pretreatment of cells with PP2 increased Erk1/2 (mitogen-activated protein kinase [MAPK]) phosphorylation and in vitro kinase activity, particularly after prolonged TPO stimulation. Taken together, our results show that Mpl stimulation results in the activation of Lyn kinase, which appears to limit the proliferative response through a signaling cascade that regulates MAPK activity. These data suggest that SFKs modify the rate of TPO-induced proliferation and are likely to affect cell cycle regulation during megakaryocytopoiesis.
Transplantation tolerance induced by intranasal administration of HY peptides
Authors: Chai Jian-Guo , James Edward , Dewchand Hamlata , Simpson Elizabeth , Scott Diane 
Published: January 2004

AbstractInduction of antigen-specific tolerance to transplantation antigens is desirable to control host-versus-graft and graft-versus-host reactions. Following molecular identification of a set of minor histocompatibility (H) antigens, we have used selected HY peptide epitopes for this purpose. Intranasal administration of individual major histocompatibility complex (MHC) class II-restricted HY peptides induces indefinite survival of syngeneic male skin grafts and allows engraftment of male bone marrow. Tolerance involves linked suppression to additional HY epitopes on test grafts. Long-term tolerance also requires suppression of emerging thymic emigrants. It does not involve deletion. HY peptide–specific CD4+ and CD8+ T cells expand on re-exposure to male antigen; these expansions are smaller in tolerant than control mice and fewer HY-specific cells from tolerant females secrete interferon γ and interleukin 10 (IL-10). Significantly, CD4+ cells from peptide-pretreated females fail to make IL-2 responses to cognate peptide, limiting expansion of the HY-specific CD8+ populations that can cause graft rejection. Consistent with this, tolerance induction by HY peptide is abrogated by coadministration of lipopolysaccharide. IL-10 does not appear to be critically involved because tolerance is inducible in IL-10–deficient mice. Adoptive transfer of tolerance into naive neonatal recipients by splenocytes from long-term tolerant donors provides evidence for involvement of regulatory cells.
Analysis of the lambdoid prophage element e14 in the E. coli K-12 genome
Authors: Mehta Preeti , Casjens Sherwood , Krishnaswamy Sankaran 
Published: January 2004

Abstract
Background
Many sequenced bacterial genomes harbor phage-like elements or cryptic prophages. These elements have been implicated in pathogenesis, serotype conversion and phage immunity. The e14 element is a defective lambdoid prophage element present at 25 min in the E. coli K-12 genome. This prophage encodes important functional genes such as lit (T4 exclusion), mcrA (modified cytosine restriction activity) and pin (recombinase).

Results
Bioinformatic analysis of the e14 prophage sequence shows the modular nature of the e14 element which shares a large part of its sequence with the Shigella flexneri phage SfV. Based on this similarity, the regulatory region including the repressor and Cro proteins and their binding sites were identified. The protein product of b1149 was found to be a fusion of a replication protein and a terminase. The genes b1143, b1151 and b1152 were identified as putative pseudogenes. A number of duplications of the stfE tail fibre gene of the e14 are seen in plasmid p15B. A protein based comparative approach using the COG database as a starting point helped detect lambdoid prophage like elements in a representative set of completely sequenced genomes.

Conclusions
The e14 element was characterized for the function of its encoded genes, the regulatory regions, replication origin and homology with other phage and bacterial sequences. Comparative analysis at nucleotide and protein levels suggest that a number of important phage related functions are missing in the e14 genome including parts of the early left operon, early right operon and late operon. The loss of these genes is the result of at least three major deletions that have occurred on e14 since its integration. A comparative protein level approach using the COG database can be effectively used to detect defective lambdoid prophage like elements in bacterial genomes.
Toll-like receptors and the host defense against microbial pathogens: bringing specificity to the innate-immune system
Authors: Netea Mihai G , Van der Graaf Chantal , Van der Meer Jos W M , Kullberg Bart Jan 
Published: January 2004

AbstractToll-like receptors (TLRs) have been identified as a major class of pattern-recognition receptors. Recognition of pathogen-associated molecular patterns (PAMPs) by TLRs, alone or in heterodimerization with other TLR or non-TLR receptors, induces signals responsible for the activation of genes important for an effective host defense, especially proinflammatory cytokines. Although a certain degree of redundancy exists between signals induced by the various TLRs, recent studies have identified intracellular pathways specific for individual TLRs. This leads to the release of cytokine profiles specific for particular PAMPs and thus, TLRs confer a certain degree of specificity to the innate-immune response. In addition to the activation of the innate-immune response, TLR-mediated recognition represents a link between the innate- and acquired-immune systems, by inducing the maturation of dendritic cells and directing the T helper responses. Alternatively, recent data have also suggested TLR-mediated escape mechanisms used by certain pathogenic microorganisms, especially through TLR2 induction of anti-inflammatory cytokines. Finally, the crucial role of TLRs for the host defense against infections has been strengthened recently by the description of patients partially defective in the TLR-activation pathways.
Fabrication and Efficient Photochromism of the Mixed Langmuir–Blodgett Films of a Water-miscible Azobenzene Amphiphile and Long-chain Alkylammoniums
Authors: Azumi Reiko , Kakiuchi Keiko , Matsumoto Mutsuyoshi 
Published: January 2004

Abstract
The fabrication and efficient photochromism of the mixed Langmuir–Blodgett films of a water-miscible azobenzene amphiphile and long-chain alkylammoniums are demonstrated. Long-chain alkylammonium can serve as a counterion to stabilize the anionic azobenzene amphiphile on the water surface, and also as a spacer around the azobenzene amphiphile to prevent the aggregation, enabling the efficient photoisomerization of azobenzene.
Hysteretic Behavior on the Heat of Protonation of Diethylenetriamine in Aqueous Solution
Authors: Maki Tei , Kanzaki Ryo , Umebayashi Yasuhiro , Ishiguro Shin-ichi 
Published: January 2004

Abstract
Hysteretic behavior was found on the heat of protonation of diethylenetriamine (dien) in aqueous solution at 298 K. We propose the presence of two conformers for Hdien+, which have significantly different proton affinities. Mutual transformation between the conformers may be practically forbidden, but is strongly accelerated upon their protonation to form H2dien2+.
The First Metal Complexes of 4,4′-Biimidazole and 4,4′-Biimidazolate with Hydrogen-Bonding Networks on the Cu(II) Complexes: 1-D Structures by N–H···X···H–N Hydrogen-Bonding
Authors: Morita Yasushi , Murata Tsuyoshi , Fukui Kozo , Tadokoro Makoto , Sato Kazunobu , Shiomi Daisuke , Takui Takeji , Nakasuji Kazuhiro 
Published: January 2004

Abstract
The Cu(II) complexes based on 4,4′-biimidazole and its deprotonated mono-anionic ligands were synthesized as the first metal complexes, which exhibit hydrogen-bonding networks. X-ray crystal structure analyses reveal the π-stacking structure of each complex and N–H···X or N···H–X type hydrogen-bondings.
Direct Observation of Polymer-Binding Site on Calcite Crystal by FE/SEM: Regulation of Binding Abilities by a Rotation of Amide Group in Poly(carboxylate) to CaCO3 Crystals
Authors: Takahashi Kazuyuki , Doi Mototsugu , Kobayashi Atsuko , Taguchi Takahisa , Onoda Akira , Okamura Taka-aki , Yamamoto Hitoshi , Ueyama Norikazu 
Published: January 2004

Abstract
Poly{1-[(Z)-3-carboxyl-2-propenylaminomethyl]ethylene} binding on the edge of calcite crystals was observed directly by 13C CP/MAS NMR and FE/SEM measurements. Comparing the results taken both before and after the washing process, we were able to make these observation because the polymer ligand weakly bound to the CaCO3 crystals.
Organic Additive-assisted Growth of Quaternary PbX(OH) (X = Cl, Br, I) Polygonal Tubular Crystals via Ethanol Thermal Process
Authors: Zhang Xu , Xie Yi , Xu Fen , Xu Di , Zhou Guien 
Published: January 2004

Abstract
Millimeter-scaled polygonal tubular crystals of PbX(OH) (X = Cl, Br, I) are successfully grown in ethanol system with the aid of polyoxyethylene tert-octylphenyl ether (Triton X-100). The results demonstrate that the suitable organic additive favors the growth of tubular crystals.
Thermal Behavior of Natural and Cation-Exchanged Clinoptilolite from Sardinia (Italy)
Authors: Langella Alessio , Pansini Michele , Cerri Guido , Cappelletti Piergiulio , de’Gennaro Maurizio 
Published: January 2004

AbstractThe thermal behavior of two clinoptilolites from an epiclastic and a pyroclastic deposit of central-northern Sardinia and of their exchanged forms (Li, Na, K, Cs, Mg, Ca, Sr and ammonium) were investigated by differential thermal analysis and thermogravimetry up to 1000°C. Their thermal stability was studied by evaluating the residual crystallinity (expressed as rehydration capacity) after 2 h thermal treatments at 450, 600 and 900°C. The water loss at 1000°C was linearly related to the radius (r) and the charge (z) of the exchangeable cations by the equations r2/z or r3/z, which are proportional to the inverse of the charge density over the surface or to the charge density over the volume of the cations.The cation composition plays a crucial role in determining the thermal behavior of clinoptilolite. The presence of cations such as Cs or K, which have low surface or volume charge densities, was found to increase the thermal resistance. In particular, the crystallinity of Cs- and K-exchanged forms of both clinoptilolites was not affected by thermal treatment at 450°C and was only slightly reduced by thermal treatment at 600°C.Predicting the thermal behavior of natural and cation-exchanged forms of these clinoptilolites can provide useful information for possible applications in catalysis, in the case of high thermal stability, or for thermal transformation into ceramics or lightweight aggregates.
Properties and Utilization of Zeolite-Blended Portland Cements
Authors: Janotka Ivan , Krajči L’udovít , Dzivák Martin 
Published: January 2004

AbstractThe resistance to acidic and sulfate attack of Portland-pozzolan cement containing 35 wt.% of zeolite was compared with that of unamended Portland cement. Mortar specimens kept in 0.5% and 1.0% HCl solution, 5% Na2SO4 solution, and in reference water for 365 and 720 days were tested using a set of physical-mechanical and chemical techniques. The ability of mortars containing zeolitic cements with 15 to 50 wt.% of zeolite to protect steel against corrosion was verified by a potentiodynamic method. Mortar with zeolitic cement performs better when exposed to 1% HCl solution due to the presence of a finer pore matrix, a hydrate phase poorer in CaO-containing hydration products with lower leachability, and the high resistance of zeolite material itself to acidic attack, compared with Portland cement and siliceous sand. The improved sulfate resistance of the mortar with zeolitic cement is caused by the decreased C3A in the cement blend in comparison with that in Portland cement, a reduction in SO3 binding into the cement paste and decreased amount of CaO-containing hydration products capable of reacting with a sulfate solution forming voluminous reaction products, and consequent crack propagation, large expansion and structural disintegration. Passivation of steel in mortars with blends of Portland cement to zeolite percentage ratios of 85/15, 75/25 and 65/35 by weight is comparable to that of Portland cement mortar. This is particularly important because the mortar with zeolitic cement exhibits late strengths similar to that of Portland cement mortar. This confirms that zeolitic cement can replace Portland cement in many applications with the advantage of higher resistance to acidic and sulfate attack.
Determination of Layer-Charge Characteristics of Smectites
Authors: Christidis G. E. , Eberl D. D. 
Published: January 2004

AbstractA new method for calculation of layer charge and charge distribution of smectites is proposed. The method is based on comparisons between X-ray diffraction (XRD) patterns of K-saturated, ethylene glycol-solvated, oriented samples and calculated XRD patterns for three-component, mixed-layer systems. For the calculated patterns it is assumed that the measured patterns can be modeled as random interstratifications of fully expanding 17.1 Å layers, partially expanding 13.5 Å layers and non-expanding 9.98 Å layers. The technique was tested using 29 well characterized smectites. According to their XRD patterns, smectites were classified as group 1 (low-charge smectites) and group 2 (high-charge smectites). The boundary between the two groups is at a layer charge of −0.46 equivalents per half unit-cell. Low-charge smectites are dominated by 17.1 Å layers, whereas high-charge smectites contain only 20% fully expandable layers on average. Smectite properties and industrial applications may be dictated by the proportion of 17.1 Å layers present. Non-expanding layers may control the behavior of smectites during weathering, facilitating the formation of illite layers after subsequent cycles of wetting and drying. The precision of the method is better than 3.5% at a layer charge of −0.50; therefore the method should be useful for basic research and for industrial purposes.
Crystallization Conditions of Fundamental Particles from Mixed-Layer Illite-Smectite of Bentonites Based on Isotopic Data (K-Ar, Rb-Sr and δ18O)
Authors: Clauer Norbert , Liewig Nicole , Pierret Marie-Claire , Toulkeridis Theofilos 
Published: January 2004

AbstractRb-Sr and oxygen isotope studies, in addition to K-Ar isotopic determinations published previously, are reported on diagenetic and hydrothermal fundamental particles (particle thickness of 0.03 to 0.05 nm and particle ab size of 0.02–0.05 µm) of the East-Slovak Basin. The combined data set allows us to ascertain the crystallization conditions of the illite material from two bentonite units collected at two basinal sites located ~20 km apart, and characterized by prolonged diagenetic conditions induced by progressive burial. A bentonite rock characterized by a short hydrothermal event from the Zempleni mountains to the SW of the East-Slovak basin is also studied.For the two first sites, the δ18O values increase in one case and decrease in the other, when the size of the diagenetic fundamental particles from bentonite samples increases. These variations suggest that temperature increased in one and decreased in the second of the two samples collected in the basin, while the particles were growing. In the case of the hydrothermal bentonite, the δ18O values of the different size-fractions consisting of fundamental particles remain about constant, suggesting constant temperature and fluid chemistry.The Rb-Sr dates of the fundamental particles of the three bentonite rocks were systematically higher than the corresponding K-Ar ages. The 87Sr/86Sr ratios, which are initially involved in the particle nucleation, appeared higher than that of contemporaneous sea-water. In all cases, the initial 87Sr/ 86Sr ratio decreases when particle size increases, which implies supply of external Sr into the bentonite units. This external Sr seems to have had an 87Sr/86Sr ratio close or identical to that of the contemporaneous sea water. This means that Sr, probably of sea-water origin, progressively diffused from host shales into the bentonite units, during burial diagenesis. In turn it favors the suggestion made previously about diffusion of K from shales into the bentonite layers during illitization of the smectite from these units.
Raman and X-ray Diffraction Data on Anatase in Fired Kaolins
Authors: Murad Enver 
Published: January 2004

AbstractThe Raman spectra of many kaolins are dominated by bands from ancillary anatase. Fired samples of a commercial anatase-bearing kaolin from the Jari River deposit in Brazil showed significant variations of Raman spectra as a function of the firing temperature. The spectra showed the full range of anatase bands up to a firing temperature of 900°C. From 950°C the background increased significantly, leading to an unfavorable signal/noise ratio that allowed observation of only the most intense (Eg) band at ~144 cm−1. X-ray diffraction (XRD), however, confirmed that this band, which persists up to 1200°C, results from anatase. Two factors may be responsible for the high thermal stability of anatase in this sample: its relatively large particle size of ~120 nm and possible reactions with Si and Al that become liberated during kaolinite breakdown. When evaluated with circumspection, Raman and XRD data on anatase can serve as ‘thermometers’ to elucidate the thermal history of fired anatase-bearing kaolins and other anatase-bearing clays.
Low-Temperature Synthesis of Micas under Conventional- and Microwave-Hydrothermal Conditions
Authors: Komarneni Sridhar , Newalkar Bharat L. 
Published: January 2004

AbstractSeveral micas containing different octahedral and interlayer cations were synthesized at different temperatures under conventional- and microwave-hydrothermal conditions and these phases were characterized by powder X-ray diffraction, solid-state magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy. A Zn K-mica with Zn in the octahedral sheets and K in the interlayers was synthesized in the temperature range 150–200°C and a novel Zn Rb-mica with Zn in the octahedral sheets and Rb in the interlayers was synthesized at 200°C. The synthesis of either Mg, Co or Ni K-micas, however, was found to be difficult or impossible at these low temperatures. Solid-state 29Si MAS-NMR revealed that the Al in the tetrahedral sites is disordered with several nearest-neighbor Si environments. In general, microwave-assisted hydrothermal conditions led to better crystallization of the Zn K-micas compared with the conventional method.
Biologie im Supermarkt: Zwischen Fett‐Ecke und Light‐Quark
Authors: Probst Wilfried , Scharf Karl‐Heinz 
Published: January 2004

AbstractWie Befragungen an Jugendlichen zeigten, sind „Einkaufslandschaften”︁ wie Supermärkte und Warenhäuser mittlerweile zu Orten der Freizeitgestaltung geworden. Im Hinblick auf die einseitige Beeinflussung der Kinder und Jugendlichen durch Angebote und Werbung sollte eine Konsumentenbildung vor Ort angestrebt werden. Erprobungen mit Lehramtsstudierenden, Schulklassen und Lehrkräften haben gezeigt, dass „Biologie im Supermarkt”︁ eine sinnvolle Ergänzung des Unterrichts darstellen kann. Dabei können in diesem Unterricht auch viele allgemeinbiologische und im Lehrplan aufgeführte Inhalte bearbeitet werden. Dies wird am Beispiel des Themas „Fette und fette Öle”︁ näher ausgeführt.
Gut gerüstet mit eisernem Schuhwerk
Authors: Knoll Ulrike 
Published: January 2004

AbstractIn der unwirtlichen Umgebung der Unterwassergeysire im Indischen Ozean kriecht eine Schnecke auf eiserner Sohle. Ihren Fuß ziert ein schuppenbesetzter Stiefel, der aus ungewöhnlichen Werkstoffen besteht.