bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diferentially expressed adenylyl cyclase isoforms mediate secretory functions in cholangiocyte subpopulation #
Authors: Strazzabosco Mario , Fiorotto Romina , Melero Saida , Glaser Shannon , Francis Heather , Spirli Carlo , Alpini Gianfranco 
Published: March 2009

Abstract
Cyclic adenosine monophosphate (cAMP) is generated by adenylyl cyclases (ACs), a group of enzymes with different tissue specificity and regulation. We hypothesized that AC isoforms are heterogeneously expressed along the biliary tree, are associated with specific secretory stimuli, and are differentially modulated in cholestasis. Small duct and large duct cholangiocytes were isolated from controls and from lipopolysaccharide-treated or α-naphthylisothiocyanate–treated rats. AC isoform expression was assessed via real-time polymerase chain reaction. Secretion and cAMP levels were measured in intrahepatic bile duct units after stimulation with secretin, forskolin, HCO3
−/CO2, cholinergic agonists, and β-adrenergic agonists, with or without selected inhibitors or after silencing of AC8 or soluble adenylyl cyclase (sAC) with small interfering RNA. Gene expression of the Ca2+-insensitive isoforms (AC4, AC7) was higher in small duct cholangiocytes, whereas that of the Ca2+-inhibitable (AC5, AC6, AC9), the Ca2+/calmodulin-stimulated AC8, and the soluble sAC was higher in large duct cholangiocytes. Ca2+/calmodulin inhibitors and AC8 gene silencing inhibited choleresis and cAMP production stimulated by secretin and acetylcholine, but not by forskolin. Secretion stimulated by isoproterenol and calcineurin inibitors was cAMP-dependent and γ-aminobutyric acid–inhibitable, consistent with activation of AC9. Cholangiocyte secretion stimulated by isohydric changes in [HCO3
−]i was cAMP-dependent and inhibited by sAC inhibitor and sAC gene silencing. Treatment with lipopolysaccharide or α-naphthylisothiocyanate increased expression of AC7 and sAC but decreased expression of the other ACs. Conclusion: These studies demonstrate a previously unrecognized role of ACs in biliary pathophysiology. In fact: (1) AC isoforms are differentially expressed in cholangiocyte subpopulations; (2) AC8, AC9, and sAC mediate cholangiocyte secretion in response to secretin, β-adrenergic agonists, or changes in [HCO3
−]i, respectively; and (3) AC gene expression is modulated in experimental cholestasis. (Hepatology 2009)
Hypoxia-inducible factor 1α is up-regulated by oncostatin M and participates in oncostatin M signaling #
Authors: Vollmer Stefan , Kappler Valérie , Kaczor Jakub , Flügel Daniela , Rolvering Catherine , Kato Nobuyuki , Kietzmann Thomas , Behrmann Iris , Haan Claude 
Published: March 2009

Abstract
The interleukin-6–type cytokine oncostatin M (OSM) acts via the Janus kinase/signal transducer and activator of transcription pathway as well as via activation of mitogen-activated protein kinases and is known to critically regulate processes such as liver development and regeneration, hematopoiesis, and angiogenesis, which are also determined by hypoxia with the hypoxia-inducible factor 1α (HIF1α) as a key component. Here we show that treatment of hepatocytes and hepatoma cells with OSM leads to an increased protein level of HIF1α under normoxic and hypoxic conditions. Furthermore, the OSM-dependent HIF1α increase is mediated via Janus kinase/signal transducer and activator of transcription 3 and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase 1/2 pathways. OSM-mediated HIF1α up-regulation did not result from an increase in HIF1α protein stability but from increased transcription from the HIF1α gene. In addition, we show that the OSM-induced HIF1α gene transcription and the resulting enhanced HIF1α protein levels are important for the OSM-dependent vascular endothelial growth factor and plasminogen activator inhibitor 1 gene induction associated with several diseases. Conclusion: HIF1α levels increase significantly after treatment of hepatocytes and hepatoma cells with OSM, and HIF1α contributes to OSM downstream signaling events, pointing to a cross-talk between cytokine and hypoxia signaling in processes such as liver development and regeneration. (Hepatology 2009.)
Chromodomain helicase/adenosine triphosphatase DNA binding protein 1–like (CHD1l) gene suppresses the nucleus-to-mitochondria translocation of nur77 to sustain hepatocellular carcinoma cell survival #
Authors: Chen Leilei , Hu Liang , Chan Tim Hon Man , Tsao George Sai-Wah , Xie Dan , Huo Ke-Ke , Fu Li , Ma Stephanie , Zheng Bo-Jian , Guan Xin-Yuan 
Published: March 2009

Abstract
Amplification of 1q21 has been detected in 58% to 78% of primary hepatocellular carcinoma cases, suggesting that one or more oncogenes within the amplicon play a critical role in the development of this disease. The chromodomain helicase/adenosine triphosphatase DNA binding protein 1–like gene (CHD1L) is a recently identified oncogene localized at 1q21. Our previous studies have demonstrated that CHD1L has strong tumorigenic ability and confers high susceptibility to spontaneous tumors in a CHD1L-transgenic mouse model. In this study, we demonstrate that the antiapoptotic ability of CHD1L is associated with its interaction with Nur77, a critical member of a p53-independent apoptotic pathway. As the first cellular protein identified to bind Nur77, CHD1L is able to inhibit the nucleus-to-mitochondria translocation of Nur77, which is the key step of Nur77-mediated apoptosis, resulting in the hindrance of the release of cytochrome c and the initiation of apoptosis. Knock-down of CHD1L expression by RNA interference could rescue the mitochondrial targeting of Nur77 and the subsequent apoptosis. Further studies found that the C-terminal Macro domain of CHD1L is responsible for the interaction with Nur77, and a CHD1L mutant lacking residues 600-897 failed to interact with Nur77 and prevented Nur77-mediated apoptosis. More importantly, we found that the inhibition of Nur77-mediated apoptosis by endogenous CHD1L is a critical biological cellular process in hepatocarcinogenesis. Conclusion: We demonstrate in this study that overexpression of CHD1L could sustain tumor cell survival by preventing Nur77-mediated apoptosis. (Hepatology 2009.)
Tumor microvasculature supports proliferation and expansion of glioma‐propagating cells
Authors: Borovski Tijana , Verhoeff Joost J.C. , ten Cate Rosemarie , Cameron Kate , de Vries Nienke A. , van Tellingen Olaf , Richel Dirk J. , van Furth Wouter R. , Medema Jan Paul , Sprick Martin R. 
Published: March 2009

AbstractGlioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. The identification of ‘cancer stem cells’ (CSC) has shed new light on the potential mechanism of therapy resistance of these tumors. Because these cells appear to be more resistant to conventional treatments, they are thought to drive tumor regrowth after therapy. Therefore, novel therapeutic approaches that target these cells are needed. Tumor cells interact with their microenvironment. It has been reported that close contact between CSCs and tumor microvascular endothelium in GBM is important for CSCs to preserve their undifferentiated state and self‐renewal ability. However, our understanding of this interaction is still rudimentary. This is in part due to a lack of suitable in vitro models that accurately represent the in vivo situation. Therefore, we set up a co‐culture system consisting of primary brain tumor microvascular endothelial cells (tMVECs) and glioma propagating cells (GPCs) derived from biopsies of GBM patients. We found that tMVECs support the growth of GPCs resulting in higher proliferation rates comparing to GPCs cultured alone. This effect was dependent on direct contact between the 2 cell types. In contrast to GPCs, the FCS‐cultured cell line U87 was stimulated by culturing on tMVEC‐derived ECM alone, suggesting that both cell types interact different with their microenvironment. Together, these results demonstrate the feasibility and utility of our system to model the interaction of GPCs with their microenvironment. Identification of molecules that mediate this interaction could provide novel targets for directed therapy for GBM. © 2009 UICC
Systemic inflammation increases cancer cell adhesion to hepatic sinusoids by neutrophil mediated mechanisms
Authors: McDonald Braedon , Spicer Jonathan , Giannais Betty , Fallavollita Lucia , Brodt Pnina , Ferri Lorenzo E. 
Published: March 2009

AbstractInteractions between endothelial selectins and selectin ligands expressed on tumor cells have been implicated in the binding of circulating metastatic cancer cells to the vascular endothelium during extravasation. Moreover, there is mounting evidence that inflammatory environments can accelerate the progression of metastasis by neutrophil mediated mechanisms. In this study, a physiologically relevant in vivo model of early metastasis coupled with intravital microscopy was used to visualize the trafficking of tumor cells within the liver vasculature in real time. Using GFP‐labeled Lewis lung carcinoma subline H‐59 cells, we show here that disrupting the interactions between endothelial selectins and tumor cell selectin ligands diminished tumor cell recruitment to the liver. Furthermore, systemic inflammation induced by intravenous injection of lipopolysaccharide significantly enhanced the metastatic potential of these lung carcinoma cells by increasing their propensity to adhere to the liver sinusoidal endothelium. Confocal microscopy revealed frequent colocalization of cancer cells with neutrophils and neutrophil depletion in vivo significantly attenuated the lipopolysaccharide‐induced increase in H‐59 cell adhesion. Although direct selectin–selectin ligand interactions contributed significantly to tumor cell adhesion to sinusoidal endothelial cells, we show here that in addition, interactions between adherent neutrophils within the inflamed sinusoids and circulating tumor cells may further increase tumor cell arrest in the liver. © 2009 UICC
Spatial Distribution of Algal Assemblages in a Temperate Lowland Peat Bog
Authors: Machová‐Černá Kateřina , Neustupa Jiří 
Published: March 2009

AbstractSamples of phytobenthos were collected during three different seasons in 2005 along a linear transect of a lowland peat bog at various spatial scales (10 cm, 1 m, 10 m) to investigate the seasonal dynamics, diversity, and factors influencing the spatial patterns of microalgal communities. Non‐metric multidimensional scaling (NMDS), similarity percentage (SIMPER) analyses, ANOSIM, Mantel tests and diversity indices were used to analyze the data. Seasonal dynamics were exhibited by an increase in diversity, and a decrease in dominance from May to October, with significant differences in species composition. Mantel tests showed the significant influence of distance, microhabitat type, and conductivity on maintaining the similarity of species composition on scales of 1 m and 10 m. The small‐scale processes (colonization and niche differentiation), microhabitat type, geographic distance and conductivity were found to be the main factors influencing the distribution of algal assemblages. We conclude that these factors are related to winter disturbance, and the consequent colonization and subsequent niche differentiation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Limnology of the Crater Lake Cuicocha, Ecuador, a Cold Water Tropical Lake
Authors: Gunkel Günter , Beulker Camilla 
Published: March 2009

AbstractCuicocha (3380 m a.s.l.) is a young, a few hundred years old volcanic lake in the western cordilleras of the Ecuadorian Andes with some post‐volcanic activities, such as emission of volcanic gases and input of hydrothermal water. Water chemistry is influenced by the emission of CO2 and weathering of the young andesitic rocks in the water shed. A calcium cycle exists in the lake with intensive biological Ca precipitation at the flanks and formation of travertine crusts, while in the hypolimnion dissolution of Ca carbonate occurs. The crater lake is oligotrophic, biodiversity is low; the littoral flora and fauna is more important than the pelagic species. In the littoral zone, a small Totora zone occurs, followed by submerged macrophytes down to 35 m water depth. Phyto‐ and zooplankton occur down into the hypolimnion. Phytoplankton is strongly influenced by down‐welling of water (atelomixis) and by coprecipitation with detritial flocs (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydroacoustic Estimates of Fish Population Depths and Densities at Increasingly Longer Time Scales
Authors: Busch Susan , Mehner Thomas 
Published: March 2009

AbstractTo assess the reliability of depth and density estimates of vertically migrating fish (Coregonus spp.), repeated hydroacoustic surveys were conducted in a stratified lake during the same day, during subsequent nights within a week, and over four months of a year. The reliability of the hydroacoustic method, determined by the coefficient of variance of population depth of fish, was high within nights, but decreased with increasingly longer time scales. Volumetric fish densities were likewise more variable between surveys at longer temporal distances than at short‐term scales. Night‐time population depths of fish were highly correlated to the vertical position of the thermocline. Over the diel cycle, the depth distribution of the coregonids was also correlated to light intensities at the surface. We conclude that single hydroacoustic surveys reliably reflect the depth distribution and volumetric density of the fish populations in a deep lake at temporal scales of up to a week. At longer scales, physical forcing may change the depth distribution of fish, and population dynamics may alter the density estimates substantially (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ATP and Ergosterol as Indicators of Fungal Biomass during Leaf Decomposition in Streams: a Comparative Study
Authors: Abelho Manuela 
Published: March 2009

AbstractErgosterol and ATP concentrations, microbial respiration and sporulation rates of aquatic hyphomycetes associated with leaves of Castanea sativa decomposing in a 5th order stream were determined periodically over a period of 102 days in order to compare ergosterol and ATP as indicators of fungal biomass. ATP and ergosterol concentrations exhibited a significant positive correlation (F = 4.459, DF = 28, P < 0.001) during the first stages of leaf breakdown (until day 39), i.e., during periods of increasing fungal biomass. No correlation was found between ATP and ergosterol concentrations during later stages of decomposition (days 39 to 102). Respiration rates increased rapidly up to 0.525 mg O2 h–1 g–1 AFDM during the first month and remained high until the end of the experiment. Sporulation rates peaked at day 9 (1069 conidia day–1 mg–1 AFDM) and decreased during later stages of decomposition. ATP‐to‐biomass conversion factors were determined for both fungi (0.59 μmol ATP g–1 dry mass) and bacteria (1.30 μmol ATP g–1 dry mass) collected from the stream and grown in the laboratory. Estimates of fungal biomass based on ATP concentrations were similar to those calculated from ergosterol concentrations during the first 39 days of breakdown. The results here presented suggest that ATP is a reliable method to quantify microbial biomass in streams and that the relative importance of bacteria increases at later stages of decomposition. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Life History of a Population of Protonemura intricata (Ris, 1902) (Insecta, Plecoptera) in a Constant Temperature Stream in Central Europe
Authors: Kozáčeková Zuzana , de Figueroa José Manuel Tierno , López‐Rodríguez Manuel Jesús , Beracko Pavel , Derka Tomas 
Published: March 2009

AbstractThe nymphal biology (life cycle, secondary production and feeding) of a population of Protonemura intricata was studied in a calcareous stream with almost constant temperature (7–8 °C) through the year at Prosiek valley (Chočské Vrchy Mts., West Carpathians, Slovakia). The results were compared with those previously known for this species in other areas. According to our data, the species has a complicated life cycle consisting of two cohorts with different duration (probably a cohort splitting). This life cycle seems to be uncommon among the Plecoptera, which usually has simple univoltine or semivoltine life cycles, and could be probably attributed to the constant temperature regime similar to that of tropical environments. One factor, the photoperiod length, was positively correlated with monthly growth rates. The nymphal growth varied throughout the year, but the highest growth was in late spring and summer, and the lowest was in winter. The annual secondary production was very high (909.4 mg · m–2) despite not being the most frequent taxon in the stream. The highest monthly production values were observed in the autumnal‐winter period (November–December) due to massive hatching of nymphs. The lowest production values were observed in late summer and early autumn. Analyses of gut contents showed that this species behaves mainly as gatherer‐collector, but also as shredder and, occasionally, as scraper. Changes in the gut content composition were detected in relation to the size. Comparing our results with those of the literature, it can be inferred that different populations of P. intricata can show notable differences in their life history when inhabiting places with different thermal conditions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The price consideration model of brand choice
Authors: Ching Andrew , Erdem Tülin , Keane Michael 
Published: March 2009

AbstractThe workhorse brand choice models in marketing are the multinomial logit (MNL) and nested multinomial logit (NMNL). These models place strong restrictions on how brand share and purchase incidence price elasticities are related. In this paper, we propose a new model of brand choice, the “price consideration” (PC) model, that allows more flexibility in this relationship. In the PC model, consumers do not observe prices in each period. Every week, a consumer decides whether to consider a category. Only then does he/she look at prices and decide whether and what to buy. Using scanner data, we show the PC model fits much better than MNL or NMNL. Simulations reveal the reason: the PC model provides a vastly superior fit to inter‐purchase spells. Copyright © 2009 John Wiley & Sons, Ltd.
Bayesian estimation of random‐coefficients choice models using aggregate data
Authors: Musalem Andrés , Bradlow Eric T. , Raju Jagmohan S. 
Published: March 2009

AbstractThis article discusses the use of Bayesian methods for estimating logit demand models usingaggregatedata. We analyze two different demand systems: independent samples and consumer panel. Under the first system, there is a different and independent random sample ofNconsumers in each period and each consumer makes only a single purchase decision. Under the second system, the sameNconsumers make a purchase decision in each ofTperiods. Interestingly, there exists an asymptotic link between these two systems, which has important implications for the estimation of these demand models. The proposed methods are illustrated using simulated and real data. Copyright © 2009 John Wiley & Sons, Ltd.
Consumer price evaluations through choice experiments
Authors: Sándor Zsolt , Franses Philip Hans 
Published: March 2009

AbstractWe collect experimental choice data and estimate preferences for mobile phones with a special focus on measuring consumer price evaluations when consumers face difficult choice tasks. For this purpose we employ a heteroskedastic random coefficient logit model in which the variance of the extreme value error term depends on variables that affect the consistency (with rational behavior) of choice. We specify the price of some products in the choice experiment with discount and seek to answer the question how consumers evaluate these. We find evidence in our data that the prices specified with discount significantly compromise the consistency of choice. Copyright © 2009 John Wiley & Sons, Ltd.
IL‐12 stimulates the osteoclast inhibitory peptide‐1 (OIP‐1/hSca) gene expression in CD4+ T cells
Authors: Shanmugarajan Srinivasan , Kawanabe Noriaki , Koide Masanori , Tsuruga Eichi , Arroyo Jazmine E. , Key Lyndon L. , Reddy Sakamuri V. 
Published: March 2009

AbstractImmune cell products such as interferon (IFN)‐γ and interleukin (IL)‐12 are potent inhibitors of osteoclast formation. We previously characterized the human osteoclast inhibitory peptide‐1 (OIP‐1/hSca), a Ly‐6 gene family member and showed IFN‐γ modulation of OIP‐1 expression in bone marrow cells. Whether, IL‐12 regulates OIP‐1 expression in the bone microenvironment is unclear. Real‐time PCR analysis revealed that IL‐12 treatment significantly enhanced OIP‐1 mRNA expression in human bone marrow mononuclear cells. Because IL‐12 induces IFN‐γ production by T cells, we tested whether IFN‐γ participates in IL‐12 stimulation of OIP‐1 gene expression in these cells. IL‐12 treatment in the presence of IFN‐γ neutralizing antibody significantly increased OIP‐1 mRNA expression, suggesting that IL‐12 directly regulates OIP‐1 gene expression. Interestingly, real‐time PCR analysis demonstrated that IL‐12 induces OIP‐1 expression (3.2‐fold) in CD4+ T cells; however, there was no significant change in CD8+ T cells. Also, IL‐12 (10 ng/ml) treatment of Jurkat cells transfected with OIP‐1 gene (−1 to −1,988 bp) promoter‐luciferase reporter plasmid demonstrated a 5‐fold and 2.7‐fold increase in OIP‐1 gene promoter activity in the presence and absence of antibody against IFN‐γ, respectively. We showed that STAT‐1,3 inhibitors treatment significantly decreased IL‐12 stimulated OIP‐1 promoter activity. Chromatin immunoprecipitation (ChIP) assay confirmed STAT‐3, but not STAT‐1 binding to the OIP‐1 gene promoter in response to IL‐12 stimulation. These results suggest that IL‐12 stimulates the OIP‐1 gene expression through STAT‐3 activation in CD4+ T cells. J. Cell. Biochem. 107: 104–111, 2009. © 2009 Wiley‐Liss, Inc.