bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insulin‐like growth factor binding protein‐2 mediates the inhibition of DNA synthesis by transforming growth factor‐β in mink lung epithelial cells*†
Authors: Dong Feng , WU Hai‐Bin , Hong Jiang , Rechler Matthew M. 
Published: August 2002

AbstractInsulin‐like growth factor binding protein‐3 (IGFBP‐3) has been proposed to mediate the growth inhibitory effects of transforming growth factor (TGF)‐β in breast and prostate cancer cells. Both TGF‐β and exogenous IGFBP‐3 inhibit DNA synthesis in Mv1 mink lung epithelial cells (CCL64). The present study asks whether IGFBPs synthesized by CCL64 cells mediate growth inhibition by TGF‐β. CCL64 cells synthesize and secrete a single 34‐kDa IGFBP that was identified as IGFBP‐2 by immunoprecipitation and immunodepletion. Recombinant bovine IGFBP‐2 inhibited CCL64 DNA synthesis in serum‐free media in an IGF‐independent manner. Coincubation with Leu60‐IGF‐I, an IGF‐I analog that binds to IGFBPs with higher affinity than to IGF‐I receptors, decreased the inhibition by bIGFBP‐2. Leu60‐IGF‐I also decreased the inhibition of CCL64 DNA synthesis by TGF‐β by up to 70%, whereas Long‐R3‐IGF‐I, an IGF‐I analog with higher affinity for IGF‐I receptors than for IGFBPs, did not decrease inhibition, suggesting that the effect of Leu60‐IGF‐I resulted from its forming complexes with endogenous IGFBPs. Leu60‐IGF‐I did not decrease TGF‐β stimulation of a Smad3‐dependent reporter gene. Following incubation of intact CCL64 cells with bIGFBP‐2 at 0°C, bIGFBP‐2 was recovered in membrane fractions; membrane association was abolished by coincubation with Leu60‐IGF‐I. If exogenous and secreted IGFBP‐2 must bind to CCL64 cells to inhibit DNA synthesis, Leu60‐IGF‐I might reduce the inhibition of DNA synthesis by bIGFBP‐2 or TGF‐β by inhibiting the association of IGFBP‐2 in the media with CCL64 cells. Since TGF‐β does not increase IGFBP‐2 abundance, we propose that TGF‐β sensitizes CCL64 cells to the latent growth inhibitory activity of endogenous IGFBP‐2 by potentiating an intracellular IGFBP‐2 signaling pathway or by promoting the association of secreted IGFBP‐2 with the plasma membrane. J. Cell. Physiol. 190: 63–73, 2002. Published 2002 Wiley‐Liss, Inc.
Inhibition of Caco‐2 cell proliferation by all‐trans retinoic acid: Role of insulin‐like growth factor binding protein‐6
Authors: Kim Eun J. , Kang Young‐Hee , Schaffer Beverly S. , Bach Leon A. , MacDonald Richard G. , Park Jung H.Y. 
Published: August 2002

AbstractThe present study examined the effects of all‐trans retinoic acid (tRA) on proliferation and expression of the IGF system in Caco‐2 human colon adenocarcinoma cells. tRA inhibited Caco‐2 cell proliferation in a dose‐dependent manner, with a 40 ± 2% decrease in cell number observed 48 h after the addition of 1 μM tRA. Ligand blot analysis of IGFBPs in conditioned media revealed that Caco‐2 cells produced three IGFBPs of Mr: 34,000 (IGFBP‐2), 24,000 (IGFBP‐4), and 32,000 (IGFBP‐6). The concentrations of IGFBP‐2 and IGFBP‐4 decreased by 48 ± 6 and 70 ± 13%, respectively, whereas that of IGFBP‐6 increased by 698 ± 20% with 1 μM tRA. tRA decreased mRNA levels of IGFBP‐2 and IGFBP‐4 by 20 ± 3 and 50 ± 8%, respectively, whereas tRA increased IGFBP‐6 mRNA by 660 ± 20%. tRA did not alter levels of IGF‐II mRNA or peptide. To examine if endogenous IGFBP‐6 inhibits cell proliferation, Caco‐2 cells were transfected with an IGFBP‐6 cDNA expression construct or pcDNA3 vector only and stable clones were selected. Clones overexpressing IGFBP‐6 grew more slowly than vector controls and achieved final densities 30–55% lower than those of vector controls. Accumulation of IGFBP‐6 mRNA and concentrations of IGFBP‐6 peptide in conditioned media were increased by 200–250 and 220–250%, respectively, in the IGFBP‐6 clones compared with controls. Increased expression of IGFBP‐6, which has a high binding affinity for IGF‐II, following tRA treatment suggests that the decreased proliferation caused by tRA may result, at least in part, from IGFBP‐6‐mediated disruption of the IGF‐II autocrine loop in these colon cancer cells. J. Cell. Physiol. 190: 92–100, 2002. © 2002 Wiley‐Liss, Inc.
P2Y2 nucleotide receptor signaling in human monocytic cells: Activation, desensitization and coupling to mitogen‐activated protein kinases
Authors: Santiago‐Pérez Laura I. , Flores Rosa V. , Santos‐Berríos Cynthia , Chorna Nataliya E. , Krugh Brent , Garrad Richard C. , Erb Laurie , Weisman Gary A. , González Fernando A. 
Published: August 2002

AbstractActivation of P2Y2 receptors by extracellular nucleotides has been shown to induce phenotypic differentiation of human promonocytic U937 cells that is associated with the inflammatory response. The P2Y2 receptor agonist, UTP, induced the phosphorylation of the MAP kinases MEK1/2 and ERK1/2 in a sequential manner, since ERK1/2 phosphorylation was abolished by the MEK1/2 inhibitor PD 098059. Other results indicated that P2Y2 receptors can couple to MAP kinases via phosphatidylinositol 3‐kinase (PI3K) and c‐src. Accordingly, ERK1/2 phosphorylation induced by UTP was inhibited by the PI3K inhibitors, wortmannin and LY294002, and the c‐src inhibitors, radicicol and PP2, but not by inhibitors of protein kinase C (PKC). The phosphorylation of ERK1/2 was independent of the ability of P2Y2 receptors to increase the concentration of intracellular free calcium, since chelation of intracellular calcium by BAPTA did not diminish the phosphorylation of ERK1/2 induced by UTP. A 5‐minute treatment with UTP reduced U937 cell responsiveness to a subsequent UTP challenge. UTP‐induced desensitization was characterized by an increase in the EC50 for receptor activation (from 0.44 to 9.3 μM) and a dramatic (∼75%) decrease in the maximal calcium mobilization induced by a supramaximal dose of UTP. Phorbol ester treatment also caused P2Y2 receptor desensitization (EC50 = 12.3 μM UTP and maximal calcium mobilization reduced by ∼33%). The protein kinase C inhibitor GF 109203X failed to significantly inhibit the UTP‐induced desensitization of the P2Y2 receptor, whereas the protein phosphatase inhibitor okadaic acid blocked receptor resensitization. Recovery of receptor activity after UTP‐induced desensitization was evident in cells treated with agonist for 5 or 30 min. However, P2Y2 receptor activity remained partially desensitized 30 min after pretreatment of cells with UTP for 1 h or longer. This sustained desensitized state correlated with a decrease in P2Y2 receptor mRNA levels. Desensitization of ERK1/2 phosphorylation was induced by a 5‐minute pretreatment with UTP, and cell responsiveness did not return even after a 30‐minute incubation of cells in the absence of an agonist. Results suggest that desensitization of the P2Y2 receptor may involve covalent modifications (i.e., receptor phosphorylation) that functionally uncouple the receptor from the calcium signaling pathway, and that transcriptional regulation may play a role in long‐term desensitization. Our results indicate that calcium mobilization and ERK1/2 phosphorylation induced by P2Y2 receptor activation are independent events in U937 monocytes. © 2001 Wiley‐Liss, Inc.
Monocytic cell adhesion to intact and plasmin‐modified fibrinogen: Possible involvement of Mac‐1 (CD11b/CD18) and ICAM‐1 (CD54)
Authors: Arefieva T.L. , Krasnikova Tatiana L. 
Published: August 2002

Abstractβ2‐integrin Mac‐1 and immunoglobulin‐like ICAM‐1 adhesion molecules are expressed by monocytes and both known to bind fibrinogen and its degradation products. Here, we investigated whether fibrinogen cleavage with plasmin modulates the adherence of monocytic cells and what types of adhesion molecules are involved. Using several cell types, characterized by different patterns of Mac‐1 and ICAM‐1 expression, and monoclonal antibodies against β2‐integrins and ICAM‐1 we demonstrate, that fibrinogen cleavage evokes gradual decrease in β2‐integrin‐dependent cell adhesion. Furthermore, generation of the early degradation products, fragments X and Y, by minimum cleavage of fibrinogen stimulates cell adhesion, mediated by ICAM‐1. © 2001 Wiley‐Liss, Inc.
Catalytic wet air oxidation of phenol using active carbon: performance of discontinuous and continuous reactors
Authors: Stüber Frank , Polaert Isabelle , Delmas Henri , Font Josep , Fortuny Agustí , Fabregat Azael 
Published: August 2002

AbstractCatalytic wet air oxidation (CWAO) of an aqueous phenol solution using active carbon (AC) as catalytic material was compared for a slurry and trickle bed reactor. Semi‐batchwise experiments were carried out in a slurry reactor in the absence of external and internal mass transfer. Trickle‐bed runs were conducted under the same conditions of temperature and pressure. Experimental results from the slurry reactor study showed that the phenol removal rate significantly increased with temperature and phenol concentration, whereas partial oxygen pressure had little effect. Thus, at conditions of 160 °C and 0.71 MPa of oxygen partial pressure, almost complete phenol elimination was achieved within 2 h for an initial phenol concentration of 2.5 g dm−3. Under the same conditions of temperature and pressure, the slurry reactor performed at much higher initial rates with respect to phenol removal than the trickle bed reactor, both for a fresh active carbon and an aged active carbon, previously used for 50 h in the trickle bed reactor, but mineralisation was found to be much lower in the slurry reactor. Mass transfer limitations, ineffective catalyst wetting or preferential flow in the trickle bed alone cannot explain the drastic difference in the phenol removal rate. It is likely that the slurry system also greatly favours the formation of condensation polymers followed by their irreversible adsorption onto the AC surface, thereby progressively preventing the phenol molecules to be oxidised. Thus, the application of this type of reactor in CWAO has to be seriously questioned when aiming at complete mineralisation of phenol. Furthermore, any kinetic study of phenol oxidation conducted in a batch slurry reactor may not be useful for the design and scale‐up of a continuous trickle bed reactor.© 2001 Society of Chemical Industry
Liquid phase hydrogenation of benzene to cyclohexene on ruthenium catalysts supported on zinc oxide‐based binary oxides
Authors: Hu Sung‐Cheng , Chen Yu‐Wen 
Published: August 2002

AbstractA series of binary oxide‐supported ruthenium catalysts with zinc oxide as a component of the support was prepared. Zinc oxide was a major component of the support, the other component was lanthanum oxide, zirconium oxide, chromium oxide, barium oxide, gallium oxide, strontium oxide, calcium oxide or magnesium oxide. Liquid phase hydrogenation of benzene to cyclohexene was studied on these catalysts in a stirred tank reactor at a hydrogen pressure of 2.5–6.0 MPa and 448 K. The reaction was operated in a kinetic‐controlled regime. In order to have high selectivity to cyclohexene, a large amount of water should be present. In addition, the reaction medium should be an alkaline solution. The yield of cyclohexene was in the order: Ru/Ga2O3–ZnO > Ru/La2O3–ZnO > Ru/Cr2O3–ZnO > Ru/ZrO2–ZnO > Ru/MgO–ZnO = Ru/CaO–ZnO = Ru/SrO–ZnO = Ru/BaO–ZnO.Ru/Ga2O3–ZnO demonstrated the highest selectivity and yield of cyclohexene. A model of the low solubilities of reactants in the water film surrounding the catalyst can explain the reaction behavior of the catalyst.© 2001 Society of Chemical Industry
Adsorption and desorption characteristics of zinc on ash particles derived from oil palm waste
Authors: Chu Khim Hoong , Hashim Mohd Ali 
Published: August 2002

AbstractSolid waste such as palm fibre and shell produced by the palm oil industry is used by palm oil mills as boiler fuel to produce steam for electricity generation. The ash produced after combustion creates a disposal problem for the palm oil industry. This study explored the potential of oil palm ash as an adsorbent material for removal and recovery of zinc ions from aqueous solutions. The equilibrium uptake of zinc was found to increase with solution pH in the range 3–6, yielding a maximum adsorption capacity of 0.163 mmol g−1 of ash at a pH of 6. The affinity constant of oil palm ash was found to greatly exceed that of a commercial ion exchange resin, suggesting that oil palm ash may find potential application in treating dilute zinc‐containing waste streams. Four isotherm models were used to fit the constant pH equilibrium isotherms obtained at four different pH values. The entire data set was successfully simulated using two of the isotherm models: a Langmuir model with pH‐dependent parameters and an extended Langmuir–Freundlich model with pH‐independent parameters. The rates of adsorption and desorption for zinc were measured using a stirred‐batch contactor. The contact time required to reach apparent adsorption equilibrium was found to decrease with increasing adsorbent dosage. Both the rate and the extent of zinc desorption were affected by the pH of the desorbing solution. The adsorption and desorption rates were consistent with simple first‐order rate models.© 2002 Society of Chemical Industry
Identification, characterization, and physiological actions of factor H as an adrenomedullin binding protein present in human plasma
Authors: Pío Rubén , Elsasser Ted H. , Martínez Alfredo , Cuttitta Frank 
Published: August 2002

AbstractA recently discovered adrenomedullin binding protein has been characterized as complement factor H, an important regulator of the complement cascade. This review will describe the evidence that led to the identification of factor H as an adrenomedullin binding protein and will address the implications that such binding has in the radioimmunoassay of AM in plasma. We will also describe the possible physiological implications of AM binding: namely, factor H suppresses the antimicrobial activity of AM, enhances AM‐mediated induction of cyclic‐AMP in rat fibroblasts, and augments the AM‐mediated growth of a human cancer cell line. These initial studies suggest that factor H may be an important factor in the regulation of AM physiology. The elucidation of the mechanisms that modulate AM activity will be necessary for the understanding of the role of AM in normal and pathological conditions. Microsc. Res. Tech. 57:23–27, 2002. © 2002 Wiley‐Liss, Inc.
Are lymphocytic monoclonality and immunoglobulin heavy chain (IgH) rearrangement premalignant conditions in chronic gastritis?
Authors: Wündisch Thomas , Thiede Christian , Alpen Birgit , Stolte Manfred , Neubauer Andreas 
Published: August 2002

AbstractNormal gastric mucosa is devoid of lymphoid cells. Any increase of lymphocytes suggests chronic inflammation. Infection with Helicobacter pylori (Hp) is the major cause for nonautoimmune chronic gastritis and induces a mixed cellular response resulting in an acquired lymphoid tissue, or MALT (mucosa‐associated lymphoid tissue). Hp has also been implicated in the genesis of gastric MALT‐lymphoma. Polymerase chain reaction‐based assays to detect the expansion of monoclonal B‐cells have also been used to corroborate the diagnosis. In a considerable number of cases monoclonal B‐cells remain detectable in follow‐up biopsies, with the lymphoma being in complete histological remission. The clinical relevance of this finding is not clear yet. However, there also exist different reports that monoclonal B‐cells can be found in gastric biopsies of patients with neither a histological sign nor a present or past history of lymphoma. In the light of these findings we address the question whether B‐cell monoclonality can be seen as a premalignant condition in chronic gastritis and conclude that as of now the relevance of the finding of B‐cell monoclonality remains unclear. As of now the only and gold standard for the diagnosis of gastric MALT‐lymphoma is histopathology. Microsc. Res. Tech. 53:414–418, 2001. © 2001 Wiley‐Liss, Inc.
Exposure to exogenous DNA can modify the sensitivity of the Fas apoptotic pathway
Authors: de Carvalho Bittencourt Marcelo , Saas Philippe , Fresnay Stéphanie , Yerly‐Motta Véronique , Ferrand Christophe , Perruche Sylvain , Duperrier Anne , Hervé Patrick , Tiberghien Pierre , Chalmers David E. 
Published: August 2002

AbstractBackgroundGene‐transfer techniques are commonly employed for both in vitro and in vivo studies. However, modifications of the target cell following the introduction of the gene of interest are not often examined. These modifications can alter the immunogenicity and/or the susceptibility of the target cell to apoptosis and may produce unwanted consequences in vivo.MethodsGene transfer into the murine fibroblastic Ψ‐CRIP packaging cellline was performed using calcium phosphate precipitation, cationic liposome–DNA complexes or a retroviral RNA‐mediated method. After gene transfer, Fas expression, cytokine production, and sensitivity to Fas ligand (FasL)‐mediated death were assessed.ResultsFollowing transfection of a FasL expression vector by calcium phosphate precipitation, an unexpected increase was observed in apoptotic cell death in previously Fas‐resistant Ψ‐CRIP cells. This apoptosis was due to Fas upregulation and an increase of sensitivity to FasL‐mediated death. Other plasmids coding non‐cytotoxic factors also modulated this apoptotic pathway. Theco‐stimulatory molecule CD80 was also upregulated. Exposure to naked DNA alone elicited the same response. The effect was not dependent on the methylation status of exogenous DNA, but was found to be dependent on the target cell type and might be avoided by the use of an RNA‐mediated retroviral system.ConclusionsPlasmid transfection or simple exposure to naked DNA can increase sensitivity to apoptosis. The generation of FasL packaging cell lines is therefore limited by an increase in FasL/Fas‐mediated apoptosis. These findings should be considered when using genetically modified transplantable cells in order to prevent elimination by host cytotoxic cells and in particular when cells are engineered using FasL. Copyright © 2001 John Wiley & Sons, Ltd.
Adenovirus or HA‐2 fusogenic peptide‐assisted lipofection increases cytoplasmic levels of plasmid in nondividing endothelium with little enhancement of transgene expression
Authors: Subramanian Ajit , Ma Haiching , Dahl Kris N. , Zhu Jingya , Diamond Scott L. 
Published: August 2002

AbstractBackgroundAdenovirus‐assisted lipofection has been reported to increase transfection efficiency through mechanisms potentially involving endosome escape and/or nuclear targeting activity. Similarly, transfection with the viral fusogenic peptide HA‐2 of the influenza virus hemagglutinin can increase transfection efficiency. However, there are few studies examining the mechanism and intracellular trafficking of these viral and/or viral fusogenic peptide‐assisted lipofections.Methods and resultsEndosome escape was directly assayed with T7 RNA polymerase bound to plasmid (pTMβgal) expressing β‐galactosidase under a T7 promoter to detect transcribable plasmid that escapes the endosomal compartment. Lipofection of pTMβgal with replication‐deficient adenovirus (Ad5‐null) at a multiplicity of infection (MOI) of 100 and 1000 increased cytoplasmic levels of transcribable plasmid by 24‐ and 117‐fold, respectively, over lipofection alone, without an effect on total plasmid uptake. However, lipofection of pCMVβgal with Ad5‐null at a MOI of 100 and 1000 increased transgene expression only seven‐ and eight‐fold, respectively, over lipofection alone. Thus, a 24‐fold increase in endosome escape saturated expression from pCMVβgal and provided only a seven‐fold benefit in nondividing cells, which was not significantly increased with further increases in endosome escape. A cationic form of HA‐2 (HA‐K4) also caused significant enhancements in endosome escape, as detected with the cytoplasmic transcription assay. However, HA‐K4 enhancement of endosome escape did not correlate with transgene expression from pCMVβgal, consistent with the detection of HA‐K4‐mediated partitioning of plasmid to the insoluble fraction of the cell lysate.ConclusionThese results indicate that enhancement of endosome escape in nondividing cells does not fully alleviate rate limits related to nuclear import of the plasmid. Copyright © 2001 John Wiley & Sons, Ltd.
On splittable colorings of graphs and hypergraphs
Authors: Füredi Zoltán , Ramamurthi Radhika 
Published: August 2002

AbstractThe notion of a split coloring of a complete graph was introduced by Erdős and Gyárfás [7] as a generalization of split graphs. In this work, we offer an alternate interpretation by comparing such a coloring to the classical Ramsey coloring problem via a two‐round game played against an adversary. We show that the techniques used and bounds obtained on the extremal (r,m)‐split coloring problem of [7] are closer in nature to the Turán theory of graphs rather than Ramsey theory. We extend the notion of these colorings to hypergraphs and provide bounds and some exact results. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 226–237, 2002
Empowerment at last?
Authors: Moore Mick 
Published: August 2002

AbstractThe World Bank and other international development agencies have declared empowerment to be central to their anti‐poverty programmes. They are vague over meaning, and may be using the term partly to advance their own organizational interests. The term may imply more political confrontation than international organizations are able to cope with. If they to take empowerment seriously, they need to think more about practical strategies. Their best approach might be indirect and parametric, rather than direct and interventionist: helping to create a political environment that enables poor people to organize themselves, rather than by supporting poor peoples' organizations directly. Copyright © 2001 John Wiley & Sons, Ltd.
Attacking Poverty: but what happened to urban poverty and development?
Authors: Amis Philip 
Published: August 2002

AbstractThis paper reviews Attacking Poverty with regard to its treatment of urban poverty. The central argument is that urbanization and urban poverty are increasingly important but are largely ignored in the report. Thus the dynamics of urban poverty are overlooked and the subsequent policy suggestions are subsequently weakened. The report's emphasis on empowerment misses the historically progressive nature of urbanization as a social force. Copyright © 2001 John Wiley & Sons, Ltd.
Promises kept: enforcement and the role of rotating savings and credit associations in an economy
Authors: Chiteji N. S. 
Published: August 2002

AbstractRotating savings and credit associations (roscas) are a popular form of informal finance in developing countries. This paper examines the rosca's ability to enforce its terms of membership and the implications that this has for their existence in an economy. A connection between enforcement costs and the desirability of rosca formation is illustrated using a framework that focuses on the nature of the financial contract that the rosca offers, allowing inferences to be drawn about the likely viability of roscas throughout the development process and the implications this has for debates about financial dualism. Copyright © 2002 John Wiley & Sons, Ltd.
Putting context into ICTs in international development: an institutional networking project in Vietnam
Authors: Boyle Grant 
Published: August 2002

AbstractThis paper questions the adequacy of the technological orientation present in many popular discussions over the role of information and communications technologies (ICTs) in international development. In particular, the paper considers the impact of technology on how programme goals and development problems are understood, by relating critical computer design literature to the experience of deploying an Internet‐based research network in a university capacity‐building programme in Vietnam. The current technology‐focused discourse leads such work to tend to be envisioned merely in terms of selected means, such as ICT connectivity or skills. However, it is only through discussion of the ends, not means, of ICT deployment that the complexity of such deployment can be adequately understood. Copyright © 2002 John Wiley & Sons, Ltd.