bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Unexpected Role for p53 in Augmenting SV40 Large T Antigen-Mediated Tumorigenesis
Authors: Herzig M. , Novatchkova M. , Christofori G. 
Published: September 2004

AbstractSimian virus 40 large T antigen transforms cells by sequestration and inactivation of the tumor suppressor proteins p53, retinoblastoma gene product (pRb), and the pRb-related proteins p107 and p130. Thus, the absence of functional p53 is expected to promote T antigen-mediated tumorigenesis. However, in a transgenic mouse model of T antigen-mediated β cell carcinogenesis (Rip1Tag2), tumor volumes are significantly diminished when these mice are intercrossed with p53-deficient mice. Whereas the incidence of β tumor cell apoptosis is unaffected, their proliferation rate is reduced in p53-deficient β cell tumors
Cmdr1, a Chicken P-Glycoprotein, Confers Multidrug Resistance and Interacts with Estradiol
Authors: Edelmann H.M.L. , Duchek P. , Rosenthal F.E. , Föger N. , Glackin C. , Kane S.E. , Kuchler K. 
Published: September 2004

AbstractWe have cloned from a chicken intestinal cDNA library Cmdr1, the first avian P-glycoprotein. Cmdr1 is 67% and 69% identical to proteins encoded by the human
Constitutive Expression of Interleukin-1beta (IL-1beta) in Rat Oligodendrocytes
Authors: Blasi F. , Riccio M. , Brogi A. , Strazza M. , Taddei M.L. , Romagnoli S. , Luddi A. , DAngelo R. , Santi S. , Costantino-Ceccarini E. , Melli M. 
Published: September 2004

AbstractThe RT-PCR analysis of RNA from progenitor and differentiated primary rat oligodendrocytes, and from the oligodendrocyte CG-4 cell line, shows the presence of the IL-1β mRNA, the type I IL-1 receptor and the IL-1 receptor accessory protein in these cells.
Yeast Cells Allow High-Level Expression and Formation of Polyomavirus-Like Particles
Authors: Sasnauskas K. , Buzaite O. , Vogel F. , Jandrig B. , Razanskas R. , Staniulis J. , Scherneck S. , Krüger D. H. , Ulrich R. 
Published: September 2004

AbstractPolyomavirus-derived virus-like particles (VLPs) have been described as potential carriers for encapsidation of nucleic acids in gene therapy. Although VLPs can be generated inE. colior insect cells, the yeast expression system should be advantageous as it is well established for the biotechnological generation of products for human use, especially because they are free of toxins hazardous for humans. We selected the yeastSaccharomyces cerevisiaefor expression of the major capsid protein VP1 of a non-human polyomavirus, the hamster polyomavirus (HaPV). Two entire HaPV VP1- coding sequences, starting with the authentic and a second upstream ATG, respectively, were subcloned and expressed to high levels inSaccharomyces cerevisiae. The expressed VP1 assembled spontaneously into VLPs with a structure resembling that of the native HaPV capsid. Determination of the subcellular localization revealed a nuclear localization of some particles formed by the N-terminally extended VP1, whereas particles formed by the authentic VP1 were found mainly in the cytoplasmic compartment.
Purification and MALDI-MS Characterization of Stressin, a Stress-Associated Glycoprotein
Authors: Lauc G. , Peter-Katalinic J. , Dabelic S. , Flögel M. 
Published: September 2004

Abstract
Glycoconjugates have a whole spectrum of biological roles, from those that appear trivial to those that are crucial. Results accumulated in the past years indicate they might also play an important role in the response to stress, a complex physiological response of the human organism to various threats. We have recently identified stressin, a human serum glycoprotein, which was found to be increased under stress conditions. Here we report the purification of stressin from sera of professional soldiers and partial characterization of its protein and carbohydrate parts using lectin blotting and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS).
Stressin was purified using a combination of ammonium sulfate precipitation, ion exchange chromatography, preparative gel electrophoresis and reverse-phase HPLC. It was found to be a highly glycosylated protein. Only 21.9 kDa (out of 36.7 kDa) was the protein part, whereas the remaining 40% of the mass originated from N-linked oligosaccharides. The carbohydrate part contained 12 sialic acids moieties, nearly 90% of which were lost due to post-source decay in the field-free tube.
Tryptic fragments were produced from glycosylated and deglycosylated stressin, separated by reverse-phase HPLC and their exact molecular masses were determined using MALDI-MS. Comparison with tryptic maps of other proteins in computer databases indicated that stressin does not correspond to any already described protein.
Trypsin from Pacifastacus leninsculus Hepatopancreas: Purification and cDNA Cloning of the Synthesized Zymogen
Authors: Hernández-Cortés P. , Cerenius L. , García-Carreño F. , Söderhäll K. 
Published: September 2004

AbstractTrypsin was purified from crayfish,Pacifastacus leniusculus, hepatopancreas, and the gene that encoded this enzyme was cloned from a hepatopancreas cDNA library. Crayfish trypsin is synthesized as a zymogen according to the sequence of the putative precursor peptide. The authenticity of the trypsinogen is supported by the deduced amino acid sequence and confirmed by the N-terminal amino acid sequence of the mature protein. The enzyme has features characteristic of a trypsin, such as a specific binding pocket. Sequence comparison shows that crayfish trypsin is similar to those of other species, with the exception that six cysteine residues present in vertebrates are missing. Some structural characteristics, such as the length of the signal peptide and a calcium binding site, are similar to bacterial trypsin.
Molecular Mimicry between a Monoclonal Antibody and One Subunit of Crotoxin, a Heterodimeric Phospholipase A2 Neurotoxin
Authors: Choumet V. , Lafaye P. , Demangel C. , Bon C. , Mazié J.-C. 
Published: September 2004

AbstractCrotoxin is a heterodimeric phospholipase A2neurotoxin formed by the non-covalent association of an acidic and non-toxic subunit, CA, and a basic and weakly toxic phospholipase A2, CB. The two subunits behave in a synergistic manner. CA enhances the lethal potency of CB by increasing its selectivity of action. The mAb A-56.36, directed against the non-toxic subunit CA, was previously shown to neutralize crotoxin toxicity by dissociating the crotoxin complex. In the present report, a polypeptide sequence similarity was observed between some CDRs of mAb A-56.36 and two regions of CB (pos. 60–80 and 95–110). Phage displayed peptides corresponding to VH2 and VH3 of mAb A-56.36 and to their homologous sequences in CB bind CA to different extents. This observation shows that mAb A-56.36 interacts with a region of CA involved in its interaction with CB, therefore mimicking the binding of CB to CA. A similar approach was used to determine the regions of ammodytoxin A and of agkistrodotoxin, two phospholipase A2neurotoxins similar to CB, which are involved in the formation of heterocomplexes with CA. The analysis of these data contributes to the determination of stretches of amino acids which could constitute the paratope of mAb A-56.36, as well as the region of association of CB with CA in crotoxin.
Engineered Second Harmonic Generation in Photonic‐Crystal Slabs Consisting of Centrosymmetric Materials
Authors: Luo X. , Ishihara T. 
Published: September 2004

AbstractSecond harmonic generation (SHG) based on a quadrupole effect in photonic‐crystal slabs (PCSs) consisting of centrosymmetric materials is presented. The results show that SHG occurs when the pump mode with an asymmetric electromagnetic field distribution is coupled with the eigenmode of the PCS. Theoretical and experimental studies also show that the phase match condition can be achieved without resorting to birefringence or a quasi‐phase‐match condition when two conditions coincide: the fundamental mode and the second harmonic mode are the eigenmodes of the PCS, and they can be excited simultaneously by tuning the dispersion curves so that they cross by changing the thickness of the waveguide layer. The concept of the asymmetry of the electromagnetic field spatial mode can be used in a microcavity to obtain harmonic generation.
Hole Transport in Poly(phenylene vinylene)/Methanofullerene Bulk‐Heterojunction Solar Cells
Authors: Melzer C. , Koop E. J. , Mihailetchi V. D. , Blom P. W. M. 
Published: September 2004

AbstractA fundamental limitation of the photocurrent of solar cells based on a blend of poly(2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐p‐phenylene vinylene) (MDMO‐PPV) and [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) is caused by the mobility of the slowest charge‐carrier species, the holes in the MDMO‐PPV. In order to allow the experimentally observed photocurrents electrostatically, a hole mobility of at least 10–8 m2 V–1 s–1 is required, which exceeds the observed hole mobility in pristine MDMO‐PPV by more than two orders of magnitude. However, from space‐charge‐limited conduction, admittance spectroscopy, and transient electroluminescence measurements, we found a hole mobility of 2 × 10–8 m2 V–1 s–1 for the MDMO‐PPV phase in the blend at room temperature. Consequently, the charge‐carrier transport in a MDMO‐PPV:PCBM‐based solar cell is much more balanced than previously assumed, which is a necessary requirement for the reported high fill factors of above 50 %.
Kinetic Study of Homogeneous Alkene Hydrogenation by Model Discrimination
Authors: Greiner Lasse , Ternbach Michel Brik 
Published: September 2004

AbstractModel discrimination is one of the methods of choice to obtain a valid kinetic description of a catalytic reaction with minimal experimental effort. It allows fast judgement of catalyst behavior and its suitability for process development. Using dynamic experiments and modeling, the kinetics of a homogeneous hydrogenation with cationic rhodium‐PyrPhos {[Rh(PyrPhos)(COD)]BF4} were investigated. A set of three batch experiments allowed the discrimination between 6 models. Qualitative and quantitative descriptions of the kinetic behavior could be derived. Most importantly, evidence for catalyst deactivation was gained.
An Efficient and Improved Method for the Preparation of Nitriles from Primary Amides and Aldoximes†
Authors: Narsaiah A. Venkat , Nagaiah K. 
Published: September 2004

AbstractThe pivaloyl chloride‐pyridine system has been utilized as a novel and efficient reagent for the preparation of nitriles from primary amides and aldoximes. The reaction proceeds smoothly under mild reaction conditions and the products are obtained in excellent yields. This method is applicable to a wide range of substrates including aromatic, heterocyclic and aliphatic species. The dehydration takes place at room temperature in the case of primary amides and dichloromethane at reflux temperature is required for rapid conversion in the case of aldoximes.
Insights into the Cerium Chloride‐Catalyzed Grignard Addition to Esters
Authors: Conlon David A. , Kumke Daniel , Moeder Charles , Hardiman Michelle , Hutson Gerri , Sailer Laura 
Published: September 2004

AbstractAddition of methylmagnesium chloride to ester 1 in the presence of cerium chloride gave significantly better yields of the tertiary alcohol 2 than the reaction performed in the absence of cerium chloride. The beneficial effect of added cerium chloride is postulated to be due to suppression of the enolization of the ketone intermediate. The use of properly “activated” anhydrous cerium chloride which is proposed to generate a less basic, more nucleophilic species to overcome this undesired reaction was found to be critical. The activated cerium chloride was identified as the known seven‐coordinate THF solvate, [CeCl(μ‐Cl)2(THF)2]n. Inactive crystal forms were also identified and the key parameters for formation of the active form were delineated.
Geminal Bis(sulfoximine)s: Synthesis and Applications in Asymmetric Catalysis
Authors: Reggelin M. , Weinberger H. , Spohr V. 
Published: September 2004

AbstractA number of C2‐symmetrical geminal bis(sulfoximine)s have been prepared for the first time and used as ligands in boron‐mediated reductions of acetophenone and copper complex‐catalyzed 1,4‐additions of diethylzinc to 2‐cyclohexenone. The copper complex of bis(sulfoximine) 46 was found to be highly active in this type of reaction, furnishing the addition product in nearly quantitative yield even at −90 °C. From the reaction of bis(sulfoximine) 42 with Cu(OTf)2 a copper complex was isolated and characterized by X‐ray structural analysis. A mixture of SES‐Cl and NaN3 in acetonitrile was found to behave like SES‐N3 in FeCl2‐mediated iminations of sulfoxides, affording the corresponding sulfoximines with complete retention of the sulfur configuration.
Mutation screen of the brain derived neurotrophic factor gene (BDNF): Identification of several genetic variants and association studies in patients with obesity, eating disorders, and attention‐deficit/hyperactivity disorder
Authors: Friedel S. , Fontenla Horro F. , Wermter A.K. , Geller F. , Dempfle A. , Reichwald K. , Smidt J. , Brönner G. , Konrad K. , Herpertz‐Dahlmann B. , Warnke A. , Hemminger U. , Linder M. , Kiefl H. , Goldschmidt H.P. , Siegfried W. , Remschmidt H. , Hinney A. , Hebebrand J. 
Published: September 2004

AbstractSeveral lines of evidence indicate an involvement of brain derived neurotrophic factor (BDNF) in body weight regulation and activity: heterozygous Bdnf knockout mice (Bdnf+/−) are hyperphagic, obese, and hyperactive; furthermore, central infusion of BDNF leads to severe, dose‐dependent appetite suppression and weight loss in rats. We searched for the role of BDNF variants in obesity, eating disorders, and attention‐deficit/hyperactivity disorder (ADHD). A mutation screen (SSCP and DHPLC) of the translated region of BDNF in 183 extremely obese children and adolescents and 187 underweight students was performed. Additionally, we genotyped two common polymorphisms (rs6265: p.V66M; c.−46C > T) in 118 patients with anorexia nervosa, 80 patients with bulimia nervosa, 88 patients with ADHD, and 96 normal weight controls. Three rare variants (c.5C > T: p.T2I; c.273G > A; c.*137A > G) and the known polymorphism (p.V66M) were identified. A role of the I2 allele in the etiology of obesity cannot be excluded. We found no association between p.V66M or the additionally genotyped variant c.−46C > T and obesity, ADHD or eating disorders. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148‐7299:1/suppmat/index.html. © 2004 Wiley‐Liss, Inc.
The keratins and their disorders
Authors: Rugg Elizabeth L. , Leigh Irene M. 
Published: September 2004

AbstractDiseases caused by mutations in gene encoding keratin intermediate filaments (IF) are characterized by a loss of structural integrity in the cells expressing those keratins in vivo. This is manifested as cell fragility, compensatory epidermal hyperkeratosis, and keratin filament aggregation in some affected tissues. Keratin disorders are a novel molecular category including quite different phenotypes such as epidermolysis bullosa simplex (EBS), bullous congenital ichthyosiform erthroderma (BCIE), pachyonychia congenital (PC), steatocystoma multiplex, ichthyosis bullosa of Siemens (IBS), and white sponge nevus (WSN) of the orogenital mucosa. © 2004 Wiley‐Liss, Inc.
Brainstem pathology in DYT1 primary torsion dystonia
Authors: McNaught Kevin St. P. , Kapustin Alexander , Jackson Tehone , Jengelley Toni‐Ann , JnoBaptiste Ruth , Shashidharan Pullanipally , Perl Daniel P. , Pasik Pedro , Olanow C. Warren 
Published: September 2004

AbstractDYT1 dystonia is a severe form of young‐onset dystonia caused by a mutation in the gene that encodes for the protein torsinA, which is thought to play a role in protein transport and degradation. We describe, for the first time to our knowledge, perinuclear inclusion bodies in the midbrain reticular formation and periaqueductal gray in four clinically documented and genetically confirmed DYT1 patients but not in controls. The inclusions were located within cholinergic and other neurons in the pedunculopontine nucleus, cuneiform nucleus, and griseum centrale mesencephali and stained positively for ubiquitin, torsinA, and the nuclear envelope protein lamin A/C. No evidence of inclusion body formation was detected in the substantia nigra pars compacta, striatum, hippocampus, or selected regions of the cerebral cortex. We also noted tau/ubiquitin‐immunoreactive aggregates in pigmented neurons of the substantia nigra pars compacta and locus coeruleus in all four DYT1 dystonia cases, but not in controls. This study supports the notion that DYT1 dystonia is associated with impaired protein handling and the nuclear envelope. The role of the pedunculopontine and cuneiform nuclei, and related brainstem other involved brainstem structures in mediating motor activity and muscle tone also suggest that alterations in these structures, in mediating motor activity and controlling muscle tone suggests that alterations in these structures could underlie the pathophysiology of DYT1 dystonia. Ann Neurol 2004
Crystallographic report: [Diaqua bis(2,2′‐bipyridine)(µ‐naphthalene‐1,4,5,8‐tetracarboxylato)]dizinc(II) tetrahydrate
Authors: Zhao Xiao‐Jun , Tao Jun 
Published: September 2004

AbstractThe title complex features a two‐dimensional polymeric structure owing to the presence of µ4‐bridging naphthalene‐1,4,5,8‐tetracarboxylate ligands. The trigonal bipyramidal coordination geometry for zinc is completed by a chelating 2,2′‐bipyridine and a water molecule. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Diphenyltin(IV) N‐salicylidenevalinate
Authors: Yin Han Dong , Wang Qi Bao 
Published: September 2004

AbstractThe title compound, {Ph2Sn[2‐OC6H4CHNCHCH(CH3)2COO]}, is a five‐coordinated monomer with trigonal bipyramidal tin and with the axial positions occupied by oxygen atoms derived from the tridentate ligand. Copyright © 2004 John Wiley & Sons, Ltd.
Modeling aerobic carbon oxidation and storage by integrating respirometric, titrimetric, and off‐gas CO2 measurements
Authors: Pratt Steven , Yuan Zhiguo , Keller Jurg 
Published: September 2004

AbstractA method for detailed investigation of aerobic carbon degradation processes by microorganisms is presented. The method relies on an integrated use of the respirometric, titrimetric, and off‐gas CO2 measurements. The oxygen uptake rate (OUR), hydrogen ion production rate (HPR), and the carbon dioxide transfer rate (CTR) resulting from the biological as well as physicochemical processes, coupled with a metabolic model characterizing both the growth and carbon storage processes, enables the comprehensive study of the carbon degradation processes. The method allows the formation of carbon storage products and the biomass growth rates to be estimated without requiring any off‐line biomass or liquid‐phase measurements, although the practical identifiability of the system could be improved with additional measurements. Furthermore, the combined yield for biomass growth and carbon storage is identifiable, along with the affinity constant with respect to the carbon substrate. However, the individual yields for growth and carbon storage are not identifiable without further knowledge about the metabolic pathways employed by the microorganisms in the carbon conversion. This is true even when more process variables are measured. The method is applied to the aerobic carbon substrate degradation by a full‐scale sludge using acetate as an example carbon source. The sludge was able to quickly take up the substrate and store it as poly‐β‐hydroxybutyrate (PHB). The PHB formation rate was a few times faster than the biomass growth rate, which was confirmed by off‐line liquid‐ and solid‐phase analysis. The estimated combined yield for biomass growth and carbon storage compared closely to that determined from the theoretical yields reported in literature based on thermodynamics. This suggests that the theoretical yields may be used as default parameters for modeling purposes. © 2004 Wiley Periodicals, Inc.
Stochastic modeling of the phase‐variable pap operon regulation in uropathogenic Escherichia coli
Authors: Jarboe Laura R. , Beckwith David , Liao James C. 
Published: September 2004

AbstractRegulation of the pap operon in uropathogenic Escherichia coli is phase variable. This phase variation arises from competition between regulatory proteins at two sites within the regulatory region, GATCdist and GATCprox. We have used the available literature data to design a stochastic model of the molecular interactions of pap regulation and expression during growth in a non‐glucose environment at 37°C. The resulting wild‐type model is consistent with reported data. The wild‐type model served as a basis for two “in silico” mutant models for investigating the role of key regulatory components, the GATCdist binding site and the PapI interaction with Lrp at the GATCprox site. Our results show that competition at GATCdist is required for phase variation, as previously reported. However, our results suggest that removal of competition at GATCdist does not affect initial state dependence. Additionally, the PapI involvement in Lrp translocation from GATCprox to GATCdist is required for the initial state dependence but not for phase variation. Our results also predict that pap expression is maximized at low growth rates and minimized at high growth rates. These predictions provide a basis for further experimental investigation. © 2004 Wiley Periodicals, Inc.
Trickle‐bed root culture bioreactor design and scale‐up: Growth, fluid‐dynamics, and oxygen mass transfer
Authors: Ramakrishnan Divakar , Curtis Wayne R. 
Published: September 2004

AbstractTrickle‐bed root culture reactors are shown to achieve tissue concentrations as high as 36 g DW/L (752 g FW/L) at a scale of 14 L. Root growth rate in a 1.6‐L reactor configuration with improved operational conditions is shown to be indistinguishable from the laboratory‐scale benchmark, the shaker flask (μ = 0.33 day−1). These results demonstrate that trickle‐bed reactor systems can sustain tissue concentrations, growth rates and volumetric biomass productivities substantially higher than other reported bioreactor configurations. Mass transfer and fluid dynamics are characterized in trickle‐bed root reactors to identify appropriate operating conditions and scale‐up criteria. Root tissue respiration goes through a minimum with increasing liquid flow, which is qualitatively consistent with traditional trickle‐bed performance. However, liquid hold‐up is much higher than traditional trickle‐beds and alternative correlations based on liquid hold‐up per unit tissue mass are required to account for large changes in biomass volume fraction. Bioreactor characterization is sufficient to carry out preliminary design calculations that indicate scale‐up feasibility to at least 10,000 liters. © 2004 Wiley Periodicals, Inc.
Model‐based optimization of a conductive matrix enzyme electrode
Authors: Wu Xiaoxi , Detzel Christopher J. , Van Wie Bernard J. , Haarsma Sarah J. , Kidwell David A. 
Published: September 2004

AbstractA mathematical model has been developed to describe the mechanism for internal mass transfer and enzyme reaction kinetics of an amperometric conductive matrix enzyme electrode. The model is simplified and solved analytically to arrive at a representation for the response slope in the linear range as well as for the response time. This is the first time that the response time of an enzyme electrode is described by a mathematical model. Simulations give information on how the design parameters influence the performance of the electrode for a glucose oxidase catalyzed sensing reaction process. Based on this information, several designs were constructed and tested showing suitable agreement with theoretical predictions. Finally, an optimized electrode was designed and validated. © 2004 Wiley Periodicals, Inc.