bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromatin modification of the human imprinted NDN (necdin) gene detected by in vivo footprinting
Authors: Hanel Meredith L. , Lau Jason C.Y. , Paradis Isabelle , Drouin Régen , Wevrick Rachel 
Published: January 2005

AbstractAllele‐specific transcription is a characteristic feature of imprinted genes. Many imprinted genes are also transcribed in a tissue‐ or cell type‐specific manner. Overlapping epigenetic signals must, therefore, modulate allele‐specific and tissue‐specific expression at imprinted loci. In addition, long‐range interactions with an Imprinting Center (IC) may influence transcription, in an allele‐specific or cell‐type specific manner. The IC on human chromosome 15q11 controls parent‐of‐origin specific allelic identity of a set of genes located in cis configuration within 2 Mb. We have now examined the chromatin accessibility of the promoter region of one of the Imprinting Centre‐controlled genes, NDN encoding necdin, using in vivo DNA footprinting to identify sites of DNA–protein interaction and altered chromatin configuration. We identified sites of modified chromatin that mark the parental alleles in NDN‐expressing cells, and in cells in which NDN is not expressed. Our results suggest that long‐lasting allele‐specific marks and more labile tissue‐specific marks layer epigenetic information that can be discriminated using DNA footprinting methodologies. Sites of modified chromatin mark the parental alleles in NDN‐expressing cells, and in cells in which NDN is not expressed. Our results suggest that a layering of epigenetic information controls allele‐ and tissue‐specific gene expression of this imprinted gene. J. Cell. Biochem. 94: 1046–1057, 2005. © 2005 Wiley‐Liss, Inc.
Does endogenous fatty acid metabolism allow cancer cells to sense hypoxia and mediate hypoxic vasodilatation? Characterization of a novel molecular connection between fatty acid synthase (FAS) and hypoxia‐inducible factor‐1α (HIF‐1α)‐related expression of vascular endothelial growth factor (VEGF) in cancer cells overexpressing her‐2/neu oncogene
Authors: Menendez Javier A. , Vellon Luciano , Oza Bharvi P. , Lupu Ruth 
Published: January 2005

AbstractHer‐2/neu (erbB‐2) oncogene overexpression is associated with increased tumor progression and metastasis. Fatty acid synthase (FAS), the key lipogenic enzyme responsible for the endogenous synthesis of fatty acids, has been shown to be one of the genes regulated by Her‐2/neu at the level of transcription, translation, and biosynthetic activity. Interestingly, we recently established that both pharmacological inhibition of FAS activity and silencing of FAS gene expression specifically suppress Her‐2/neu oncoprotein expression and tyrosine‐kinase activity in breast and ovarian Her‐2/neu overexpressors. Unraveling the functional organization of this novel bi‐directional molecular connection between Her‐2/neu and FAS‐dependent neoplastic lipogenesis is a major challenge that the field is only beginning to take on. Considering that Her‐2/neu overexpression correlates with increased expression of the hypoxia inducible factor‐1α (HIF‐1α), which, in a mitogen‐activated protein kinase (MAPK)‐dependent manner, plays a key role in the expression of several genes including cytokines such as vascular endothelial growth factor (VEGF), we hypothesized that FAS blockade should result in a concomitant down‐regulation of VEGF. Unexpectedly, the specific inhibition of the de novo fatty acid synthesis with the small‐molecule inhibitor of FAS activity C75 resulted in a dramatic dose‐dependent enhancement (up to 500% increase) of VEGF secretion in Her‐2/neu‐overexpressing SK‐Br3, BT‐474, and SKOV3 cancer cells. Concurrently, FAS blockade drastically activated MAPK and promoted further a prominent accumulation of HIF‐1α in Her‐2/neu overexpressors. Moreover, U0126‐induced inhibition of MAPK activity completely abolished C75‐induced up‐regulation of HIF‐1α expression and VEGF secretion, whereas it did not modulate C75‐induced down‐regulation of Her‐2/neu oncogene. Importantly, RNA interference (RNAi)‐mediated silencing of the FAS gene recapitulated C75's effects by up‐regulating VEGF secretion, MAPK activation and HIF‐1α expression. Therefore, it appears that perturbation of cancer‐associated endogenous fatty metabolism triggers a “hypoxia‐like” (oxygen‐independent) condition that actively rescues Her‐2/neu‐dependent MAPK → HIP‐1α → VEGF cascade. It is tempting to suggest that an intact FAS‐catalyzed endogenous fatty acid metabolism is a necessary metabolic adaptation to support the enhanced ability of Her‐2/neu‐overexpressing cancer cells to survive cellular hypoxia in a HIF‐α‐dependent manner. J. Cell. Biochem. 94: 857–863, 2005. © 2005 Wiley‐Liss, Inc.
Leukemia fusion proteins and co‐repressor complexes: Changing paradigms
Authors: Redner Robert L. , Liu Johnson M. 
Published: January 2005

AbstractMany cases of acute myelogenous leukemia (AML) are characterized by non‐random chromosomal translocations that fuse a DNA‐binding protein with a transcriptional regulator, which in turn may aberrantly recruit a co‐repressor complex. The similarities in this pattern between different AML chimeric fusions have led to a paradigm that stresses the importance of the co‐repressor complex in altering the pattern of expression of genes targeted by the DNA‐binding moiety of the fusion. Such findings beg the question of whether the fusion proteins merely serve as anchors to recruit the co‐repressor complex or whether they play other significant roles in leukemogenesis. The answers to this question may have therapeutic importance since we now have the ability to target various components of the co‐repressor complex, such as the histone deacetylase (HDAC) enzymes. In this Prospect, we wish to highlight some of the complexities and difficulties with the existing molecular paradigm of this challenging group of disorders. J. Cell. Biochem. 94: 864–869, 2005. © 2005 Wiley‐Liss, Inc.
Role of the retinoblastoma tumor suppressor protein in cellular differentiation
Authors: Nguyen Don X. , McCance Dennis J. 
Published: January 2005

AbstractThe retinoblastoma protein (pRb105) is a true tumor suppressor as deregulation of the Rb pathway by either mutation of pRb105 itself or other proteins in the pathway, such as p16INK4a, occur in most cancers. This prototypical family member, along with the related p107 and p130, are involved in the control of cell cycle regulation, but pRb105 has also been shown to be involved in tissue development and differentiation. This prospective will discuss the increasing evidence for a role of pRb105 in cellular differentiation and the fact that various cancers, which contain mutant pRb105, or mutations in proteins in the pRb105 pathway, are perhaps a result of deregulation of differentiation. J. Cell. Biochem. 94: 870–879, 2005. © 2005 Wiley‐Liss, Inc.
Association of cottontail rabbit papillomavirus E6 oncoproteins with the hDlg/SAP97 tumor suppressor
Authors: Du Minjie , Fan Xueli , Hanada Toshihiko , Gao Hua , Lutchman Mohini , Brandsma Janet L. , Chishti Athar H. , Chen Jason J. 
Published: January 2005

AbstractPapillomaviruses are small DNA viruses that infect epithelial tissues and cause warts. Human papillomavirus (HPV) infection is the primary risk factor for the development of cervical cancer. The E6 and E7 oncogenes are the only genes consistently expressed in HPV‐positive cervical cancer cells. Cottontail rabbit papillomavirus (CRPV) induces papillomas and carcinomas on cottontail and domestic rabbits and provides an excellent animal model of HPV infection and vaccine development. CRPV encodes three transforming proteins; LE6, SE6, and E7. Each of these proteins is required for papilloma formation. Like HPV E7, the CRPV E7 protein binds to the tumor suppressor pRB. In contrast, unlike HPV E6, the CRPV E6 proteins do not bind the tumor suppressor p53. Although more than a dozen cellular proteins have been identified as HPV E6 interacting proteins, nothing is known about the cellular interacting proteins of CRPV E6s. Here we describe the association of CRPV E6s with hDlg/SAP97, the mammalian homolog of the Drosophila discs large tumor suppressor protein. HPV E6 has previously shown to bind and target hDlg/SAP97 for degradation. Our results demonstrate that both LE6 and SE6 interact with hDlg/SAP97, although their association does not lead to the degradation of hDlg/SAP97. The PDZ domains of hDlg were shown to be sufficient for interaction with CRPV E6 proteins while the C‐terminus of CRPV E6 is essential for the interaction with hDlg. The association of hDlg with SE6 may be important but not sufficient for the transformation of NIH 3T3 cells by SE6. Importantly, a CRPV SE6 mutant defective for papilloma formation did not interact with hDlg. These results suggest that interaction with hDlg/SAP97 plays a role in the biological function of CRPV E6s. J. Cell. Biochem. 94: 1038–1045, 2005. © 2005 Wiley‐Liss, Inc.
Extracellular matrix rigidity governs smooth muscle cell motility in a biphasic fashion
Authors: Peyton Shelly R. , Putnam Andrew J. 
Published: January 2005

AbstractIncreasing evidence suggests that mechanical cues inherent to the extracellular matrix (ECM) may be equally as critical as its chemical identity in regulating cell behavior. We hypothesized that the mechanical properties of the ECM directly regulate the motility of vascular smooth muscle cells (SMCs) and tested this hypothesis using polyacrylamide substrates with tunable mechanical properties. Quantification of the migration speed on uniformly compliant hydrogels spanning a range of stiffnesses (Young's moduli values from 1.0 to 308 kPa for acrylamide/bisacrylamide ratios between 5/0.1% and 15/1.2%, respectively) revealed a biphasic dependence on substrate compliance, suggesting the existence of an optimal substrate stiffness capable of supporting maximal migration. The value of this optimal stiffness shifted depending on the concentration of ECM protein covalently attached to the substrate. Specifically, on substrates presenting a theoretical density of 0.8 μg/cm2 fibronectin, the maximum speed of 0.74 ± 0.09 μm/min was achieved on a 51.9 kPa gel; on substrates presenting a theoretical density of 8.0 μg/cm2 fibronectin, the maximum speed of 0.72 ± 0.06 μm/min occurred on a softer 21.6 kPa gel. Pre‐treatment of cells with Y27632, an inhibitor of the Rho/Rho‐kinase (ROCK) pathway, reduced these observed maxima to values comparable to those on non‐optimal stiffnesses. In parallel, quantification of TritonX‐insoluble vinculin via Western blotting, coupled with qualitative fluorescent microscopy, revealed that the formation of focal adhesions and actin stress fibers also depends on ECM stiffness. Combined, these data suggest that the mechanical properties of the underlying ECM regulate Rho‐mediated contractility in SMCs by disrupting a presumptive cell‐ECM force balance, which in turn regulates cytoskeletal assembly and ultimately, cell migration. © 2005 Wiley‐Liss, Inc.
Expression and activity of C/EBPβ and δ are upregulated by dexamethasone in skeletal muscle
Authors: Yang Hongmei , Mammen Joshua , Wei Wei , Menconi Michael , Evenson Amy , Fareed Moin , Petkova Victoria , Hasselgren Per‐Olof 
Published: January 2005

AbstractThe influence of glucocorticoids on the expression and activity of the transcription factors CCAAT/enhancer binding protein (C/EBP)β and δ in skeletal muscle was examined by treating rats or cultured L6 myotubes with dexamethasone. Treatment of rats with 10 mg/kg of dexamethasone resulted in increased C/EBPβ and δ DNA binding activity in the extensor digitorum longus muscle as determined by electrophoretic mobility shift assay (EMSA) and supershift analysis. A similar response was noticed in dexamethasone‐treated myotubes. In other experiments, myocytes were transfected with a plasmid containing a promoter construct consisting of multiple C/EBP binding elements upstream of a luciferase reporter gene. Treatment of these cells with dexamethasone resulted in a fourfold increase in luciferase activity, suggesting that glucocorticoids increase C/EBP‐dependent gene activation in muscle cells. In addition, dexamethasone upregulated the protein and gene expression of C/EBPβ and δ in the myotubes in a time‐ and dose‐dependent fashion as determined by Western blotting and real‐time PCR, respectively. The results suggest that glucocorticoids increase C/EBPβ and δ activity and expression through a direct effect in skeletal muscle. © 2005 Wiley‐Liss, Inc.
Investigation of the operation time dependence of the yield of ammonia conversion to nitrogen(II) oxide by platinum catalyst sets
Authors: Kozub Paul A , Trusov Nikolai V , Gryn Grigorii I , Prezhdo Victor V 
Published: January 2005

AbstractThe origins of changes in the catalytic activity of platinum catalysts in the ammonia oxidation process are studied. A general mathematical model for the dependence of the catalyst activity on the operation time of a single platinum gauze is proposed. Simplified expressions for the catalytic activity of two basic types of catalyst sets are obtained. Optimization of the catalyst operation mode is investigated and an optimal mode is selected based on the industrial data.© 2001 Society of Chemical Industry
Oxidative polymerization and partial dechlorination of 2,4,6‐trichlorophenol by a mixture of peroxidase isozymes from Vaccinium myrtillus
Authors: Stazi Silvia Rita , Fevereiro Pedro , Sermanni Giovanni Giovannozzi , Barros Raquel Aires 
Published: January 2005

AbstractPlant peroxidases (EC 1.11.1.7) catalyze the oxidation of phenolic pollutants in the presence of hydrogen peroxide. In the present study, extracellular peroxidases from Vaccinium myrtillus cell suspension cultures (VMP) were evaluated for their ability to polymerize 2,4,6‐trichlorophenol (TCP), a ubiquitous environmental contaminant. The effect of pH, temperature, reaction time, enzyme amount and initial pollutant concentration on the treatment efficiency was investigated in order to optimize the reaction conditions for TCP removal. An appreciable removal efficiency and a partial dehalogenation of TCP was observed over a wide range of initial pollutant concentrations (0.1–20 mmol dm−3) and reaction conditions suggesting that VMP could be useful for potential decontamination applications. The use of polyethylene glycol in the reaction mixture allowed a reduction of the catalyst requirements needed to obtain well defined extents of TCP removal.© 2001 Society of Chemical Industry
Cyclohexene hydrogenation using Group VIII metal complexes as catalysts in heterogeneous and homogeneous conditions
Authors: Quiroga M E , Cagnola E A , Liprandi D A , L'Argentière P C 
Published: January 2005

AbstractThe stability and catalytic behaviour of a ruthenium complex with chloride and tridecylamine as ligands were studied. The hydrogenation of cyclohexene carried out in mild conditions, both in homogeneous and heterogeneous conditions, was used as a test reaction. FTIR and XPS results show that the active species is the complex itself, which is stable under the reaction conditions. XPS determination shows that the ruthenium complex is tetra‐coordinated, suggesting that its formula is [RuCl2(NH2(CH2)12CH3)2]. This ruthenium complex supported on γ‐Al2O3is more active and sulfur‐resistant than the same complex unsupported and even more than a nickel complex with the above mentioned ligands. The Ru complex, supported or not, is also more active and sulfur‐resistant than a conventional Ru/γ‐Al2O3catalyst evaluated in the same operational conditions.© 2001 Society of Chemical Industry
Biotransformation of (+)‐ and (−)‐bornyl acetate using the plant parasitic fungus Glomerella cingulata as a biocatalyst
Authors: Miyazawa Mitsuo , Miyasato Yoshiki 
Published: January 2005

AbstractThe microbial transformations of (+)‐ and (−)‐bornyl acetate were investigated using the plant parasitic fungus, Glomerella cingulata. As a result, (+)‐ and (−)‐bornyl acetate were converted to (+)‐ and (−)‐5‐exo‐hydroxybornyl acetate, (+)‐ and (−)‐5‐oxobornyl acetate and (+)‐ and (−)‐borneol respectively. The structures of the metabolic products were determined by spectroscopic data.© 2001 Society of Chemical Industry
Lactic acid recovery from fermentation broth using one‐stage electrodialysis
Authors: Kim Yang Hoon , Moon Seung‐Hyeon 
Published: January 2005

AbstractOne‐stage electrodialysis (ED) for lactic acid recovery with two‐ and three‐compartment water‐splitting ED (WSED) was investigated using various ion‐exchange membranes in order to overcome the inefficiency of two‐stage ED, which consists of desalting ED for recovery and partial purification and subsequent WSED for acidification. The two‐compartment WSED had a low current efficiency and high energy consumption in spite of a simple stack configuration. A three‐compartment WSED successfully converted sodium lactate in the fermentation broth into lactic acid and sodium hydroxide with average yields of 96% and 93%, respectively. In relation to lactic acid purification, of the membranes tested in this study, the highest glucose rejection, 98.3%, was achieved using a PC 100D membrane. The CMS membrane rejected magnesium and calcium at levels as high as 81.7% and 78.5%, respectively. We concluded that the three‐compartment WSED with properly chosen membranes, enabled lactic acid to be recovered directly from the fermentation broth.© 2001 Society of Chemical Industry
Mathematical model for ethanol production from mixed sugars by Pichia stipitis
Authors: Nakamura Yoshitoshi , Sawada Tatsuro , Inoue Eiichi 
Published: January 2005

AbstractA mathematical model for estimating the dynamic behavior of ethanol production from mixed sugars such as glucose and xylose is presented. This model was constructed by introducing the term for ethanol production into the diauxic growth model proposed previously by the authors. It was assumed that the first substrate, glucose, is metabolized by a constitutive enzyme and the second substrate, xylose, is utilized by an inducible enzyme. The synthesis of the inducible enzyme is controlled by the catabolite repression caused by glucose and with the induction caused by xylose as an inducer, and the xylose is then converted into cell mass and ethanol by the inducible enzyme. The parameters of the model were estimated from the experimental data in the medium containing glucose and xylose, singly or in combination in a batch culture. The application of the model was examined for experiments in both batch and continuous culture, with glucose and xylose as carbon sources. The calculated values, according to the model, corresponded satisfactorily with experimental data, such as cell growth, substrate consumption, and ethanol production, especially in the estimation of the lag times between the first log phase and the second log phase in cell growth and ethanol production.© 2001 Society of Chemical Industry
Batch and continuous studies on treatment of pulp mill wastewater by Aeromonas formicans
Authors: Gupta V K , Minocha A K , Jain Neeraj 
Published: January 2005

AbstractBatch and continuous studies have been conducted on the treatment of black liquor from a kraft pulp and paper mill by a bacterial strain, Aeromonas formicans. The results of batch studies revealed that the strain was able to remove 71% and 78% of COD and lignin respectively, while the colour removal efficiency was around 86% in 10 days of retention time. The analysis of lignin degradation products by gas chromatography after 20 days of incubation revealed the formation of some phenolic acids, which were responsible for the decrease in pH during batch studies. The removal efficiencies of COD, colour and lignin obtained in continuous reactor studies were 73, 88 and 77% respectively for an 8 day detention period and these efficiencies were almost the same as obtained in batch studies.© 2001 Society of Chemical Industry
Simultaneous organic carbon and nitrogen removal in an SBR controlled at low dissolved oxygen concentration
Authors: Dangcong Peng , Bernet Nicolas , Delgenes Jean‐Phillipe , Moletta Rene 
Published: January 2005

AbstractSimultaneous organic carbon and nitrogen removal was studied in a sequencing batch reactor (SBR) fed with synthetic municipal wastewater and controlled at a low dissolved oxygen (DO) level (0.8 mg dm−3). Experimental results over a long time (120 days) showed that the reactor achieved high treatment capacities (organic and nitrogen loading rates reached as high as 2.4 kg COD m−3 d−1 and 0.24 kg NH3‐N m3 d−1) and efficiencies (COD, NH3‐N and total nitrogen removal efficiencies were 95%, 99% and 75%). No filamentous bacteria were found in the sludge even though the reactor had been seeded with filamentous bulking sludge. Instead, granular sludge, which possessed high activity and good settleability, was formed. Furthermore, the sludge production rate under low DO was less than that under high DO. Significant benefits, such as low investment and less operating cost, will be obtained from the new process.© 2001 Society of Chemical Industry
The effect of an enzymatic pretreatment on the hydrolysis and size reduction of fat particles in slaughterhouse wastewater
Authors: Masse L , Kennedy K J , Chou S P 
Published: January 2005

AbstractThe effect of an enzymatic pretreatment, Pancreatic Lipase 250 (PL‐250), on the hydrolysis and size reduction of fat particles in slaughterhouse wastewater was characterised for enzyme doses ranging from 125 to 1000 mg dm−3 and initial particle sizes (Din) varying between 53 and 383 µm. Treatment with PL‐250 significantly reduced the size of pork fat particles in slaughterhouse wastewater. Particle size reduction increased with Din, possibly due to the more filamentous and plate‐like configuration of the larger fat particles, which could be easily broken at weak points. The smaller particles were observed to be denser and more spherical. Size reduction also increased with enzyme concentration, but the benefit of adding more enzyme diminished greatly as enzyme dose was increased. The maximum long‐chain fatty acid (LCFA) concentration in filtered samples was detected after 4–7 h of treatment and ranged from 8.2 to 34.9 mg dm−3. The linear rate of LCFA released in solution during enzymatic pretreatment ranged from 39.4 to 169.9 mg dm−3 d−1, and increased with enzyme concentration up to 500 mg dm−3. At a PL‐250 concentration of 1000 mg dm−3, the LCFA release rate decreased, maybe due to excessive layering of adsorbed enzyme on the fat particles or increased degradation of released LCFAs. The pretreatment appeared to be more efficient with beef than pork fat particles. However, the effect of an enzymatic pretreatment on a downstream anaerobic treatment of slaughterhouse wastewater containing fat particles remains to be tested.© 2001 Society of Chemical Industry
Totally chlorine‐free bleaching of Acetosolv pulps: a clean approach to dissolving pulp manufacture
Authors: Abad Severino , Santos Valentín , Parajó Juan Carlos 
Published: January 2005

AbstractEucalyptus globulus wood samples were delignified in media containing concentrated acetic acid, water and hydrochloric acid (Acetosolv process) under optimized conditions, and the pulps were subjected to totally chlorine‐free (TCF) bleaching. Alkaline extractions, oxygen delignification, ozone treatment, enzymatic xylan removal and hydrogen peroxide oxidation in alkaline media were investigated as individual steps in selected bleaching sequences. Under the best conditions, fully bleached pulps with favourable characteristics for dissolving pulp manufacture were obtained.© 2001 Society of Chemical Industry