bluuebunny/crossref_metadata_2025 huggingface dataset:
A phenotype for genetic studies of successful cognitive aging*
Authors: Silverman Jeremy M. , Schnaider‐Beeri Michal , Grossman Hillel T. , Schmeidler James , Wang Joy Y. , Lally Rachel C.
Published: November 2007

Survival from Alzheimer's disease (AD) and other dementias into late old age may be a useful phenotype for genetic studies of successful cognitive aging. To support molecular genetics studies for successful cognitive aging, we conducted a two‐stage study to determine an optimal age phenotype for successful cognitive aging. First, risk of AD was evaluated, through informant interviews, in 4,794 parents and siblings of 976 elderly nondemented probands who were divided into three different proband age groups: those aged 60–74, 75–89, and 90+. Relatives of probands aged 90+ had a significantly lower risk than the relatives of the other two proband groups. Second, this sample was combined with an earlier sample (combined nondemented elderly probands: n = 2,025; relatives: n = 10,506), and a series of proband age groups (i.e., 75–79, 80–84, 85–89, 90+) were used to determine which optimally identifies a group of relatives with low AD risk. Using the relatives of the nondemented proband aged 60–74 as the reference group, there were reductions in cumulative risk among relatives of probands aged 85–89 and 90+, but only the latter group also showed significant reductions to the relatives of probands aged 75–79, 80–84, and 85–89. This pattern of results varied little by sex. Finally, cumulative AD risk curves were similar between relatives of probands aged 90–94 and 95+. These results suggest that age 90 is an optimal age threshold to use for both men and women in genetic studies seeking to identify genes associated with successful cognitive aging. © 2007 Wiley‐Liss, Inc.
In vitro effects of methylmercury on ascidian (Styela plicata) immunocyte responses
Authors: Cammarata M. , Parisi M.G. , Benenati G. , Arizza V. , Cillari T. , Piazzese D. , Gianguzza A. , Vazzana M. , Vizzini A. , Parrinello N.
Published: November 2007

This study shows that high methylmercury concentrations are cytotoxic for Styela plicata hemocytes, whereas sublethal concentrations affect immunocyte responses. Moreover, hemocytes exposed to the xenobiotic present a significantly enhanced phenoloxidase activity as revealed in the hemocyte lysate supernatant compared with the control. Although the cytotoxic activity of S. plicata hemocytes toward rabbit erythrocytes is a PO‐dependent cell‐target reaction due to quinone products, it was significantly decreased by suitable methylmercury concentrations in the medium. The same xenobiotic concentrations decreased the hemocyte phagocytic activity toward yeast. In both the responses cell‐target contacts could be affected by methylmercury, whereas the releasing capacity appeared to be unchanged, as indicated by hemocyte PO‐release in the medium. Finally, changes in hemocyte shape and spreading capacity were shown. On the basis of the present results, Styela plicata hemocyte responses could be an additional immunotoxicology test using a microplate method that reveals cell morphological changes and spreading capacity. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis, structural characterization and catalytic activities of dicopper(II) complexes derived from tridentate pyrazole‐based N2O ligands
Authors: Zhang Guo‐Fang , Zhou Qiu‐Ping , Dou Yin‐Li , Yin Mai‐Hua , Wang Yao
Published: November 2007

A group of a diverse family of dinuclear copper(II) complexes derived from pyrazole‐containing tridentate N2O ligands, 1,3‐bis(3,5‐dimethylpyrazol‐1‐yl)propan‐2‐ol (Hdmpzpo), 1,3‐bis(3‐phenyl‐5‐methyl pyrazol‐1‐yl)propan‐2‐ol (Hpmpzpo) and 1,3‐bis(3‐cumyl‐5‐methylpyrazol‐1‐yl)propan‐2‐ol (Hcmpzpo), were synthesized and characterized by elemental analysis, IR spectroscopy and three of them also by single‐crystal X‐ray diffraction. Three complexes, [Cu2(pmpzpo)2](NO3)2·2CH3OH (3·2CH3OH), [Cu2(pmpzpo)2](ClO4)2 (4) and [Cu2(cmpzpo)2](ClO4)2·2DMF (7·2DMF), each exhibits a dimeric structure with a inversion center being located between the two copper atoms. The metal ion is coordinated in a distorted square planar environment by two pyrazole nitrogen atoms and two bridging alkoxo oxygen atoms. Both complexes 1·CH3OH·H2O and 3·2CH3OH were investigated in anaerobic conditions for the catalytic oxidation of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to the corresponding quinone (3,5‐DTBQ), for modeling the functional properties of catechol oxidase. Copyright © 2007 John Wiley & Sons, Ltd.
Electromagnetic fields alter the expression of estrogen receptor cofactors in breast cancer cells
Authors: Girgert Rainer , Gründker Carsten , Emons Günter , Hanf Volker
Published: November 2007

Breast cancer is the most common malignancy of women in Western societies. The increasing exposure to electromagnetic fields has been suspected to contribute to the rising incidence of breast cancer in industrialized countries. The majority of breast tumors is treated with the partial antiestrogen tamoxifen. Most tumors become resistant to tamoxifen in the course of treatment resulting in treatment failure. Electromagnetic fields reduce the efficacy of tamoxifen similar to tamoxifen resistance. In this study we investigated the mechanism by which electromagnetic fields influence the sensitivity to tamoxifen. In cells exposed to 1.2 µT of a 50 Hz electromagnetic field gene expression of cofactors of the estrogen receptors was compared to sham exposed cells. Using a gene array technology several cofactors were found to be differentially expressed. The expression of the coactivators, SRC‐1 and AIB1, and of two corepressors, N‐Cor and SMRT, was quantified by RT‐PCR. Both coactivators were expressed more strongly in the exposed cells while the expression of two corepressors decreased. The RNA analysis was confirmed by Western blots. The contradirectional changes in gene expression of coactivators and corepressors by electromagnetic fields results in a lower sensitivity to tamoxifen. Electromagnetic fields may contribute to the induction of tamoxifen resistance in vivo. Bioelectromagnetics 29:169–176, 2008. © 2007 Wiley‐Liss, Inc.
Computational pore network modeling of the influence of biofilm permeability on bioclogging in porous media
Authors: Thullner Martin , Baveye Philippe
Published: November 2007

For many years, controversy has surrounded the use of biofilm models to describe the distribution of microbial biomass in natural or artificial porous media. This use is often advocated on the basis of the relative mathematical simplicity of the biofilm concept, and of the widespread availability of analytical solutions or numerical implementations. However, microscopic observations consistently point to a patchy, rather than homogeneous, distribution of microorganisms at the pore scale in many porous media of interest, even under conditions of severe bioclogging. Also, bioclogging models involving biofilms tend to underpredict the extent of permeability reductions in all be the coarse‐textured materials. In this context, computer simulations described in the present article show that some of the limitations of biofilm models to describe the bioclogging of porous media are linked to the common constitutive assumption that biofilms are impermeable, that is, that nutrient transport occurs through the biofilms only by molecular diffusion. When this restriction is alleviated and liquid flow is allowed in the biofilms, the level of bioclogging achievable by a given biomass is very significantly increased and is comparable to that observed in experiments. In addition, the distribution of microorganisms becomes patchy and exhibits a self‐organized periodic pattern with pores either entirely filled with biomass or without any biomass at all, again similar to published microscopic observations. These results suggest that biofilm models should not be ruled out a priori for the quantitative description of bioclogging in porous media, as long as biofilms are allowed to be permeable. Biotechnol. Bioeng. 2008;99: 1337–1351. © 2007 Wiley Periodicals, Inc.
Quantitative analysis of virus‐like particle size and distribution by field‐flow fractionation
Authors: Chuan Yap P. , Fan Yuan Y. , Lua Linda , Middelberg Anton P.J.
Published: November 2007

Asymmetric flow field‐flow fractionation (AFFFF) coupled with multiple‐angle light scattering (MALS) is a powerful technique showing potential for the analysis of pharmaceutically‐relevant virus‐like particles (VLPs). A lack of published methods, and concerns that membrane adsorption during sample fractionation may cause sample aggregation, have limited widespread acceptance. Here we report a reliable optimized method for VLP analysis using AFFFF‐MALS, and benchmark it against dynamic light scattering (DLS) and transmission electron microscopy (TEM). By comparing chemically identical VLPs having very different quaternary structure, sourced from both bacteria and insect cells, we show that optimized AFFFF analysis does not cause significant aggregation, and that accurate size and distribution information can be obtained for heterogeneous samples in a way not possible with TEM and DLS. Optimized AFFFF thus provides a quantitative way to monitor batch consistency for new vaccine products, and rapidly provides unique information on the whole population of particles within a sample. Biotechnol. Bioeng. 2008;99: 1425–1433. © 2007 Wiley Periodicals, Inc.
Evaluation of microfluidics reactor technology on the kinetics of virus inactivation
Authors: Bailey Mark R. , Chen Dayue , Emery Warren R. , Lambooy Peter K. , Nolting Juliana , Quertinmont Michelle T. , Shamlou Parviz A.
Published: November 2007

Mammalian cell lines constitute an important part in the manufacture of therapeutic proteins. However, their susceptibility to virus contamination is a potential risk to patient safety and productivity, and has led to the development of a repertoire of virus inactivation techniques. From a process development viewpoint, the challenge is to demonstrate the required log reduction in virus content without a significant loss in product titer or quality. The balance between the two is dictated by the kinetics of virus inactivation and protein degradation, both of which are critically affected by process parameters. In this study we describe a commercially available microchannel reactor (MCR) and demonstrate how it can be used to evaluate the impact of temperature on the kinetics of virus inactivation and protein product degradation. Virus spiking experiments are reported using Xenotropic Murine Leukemia Virus and REOvirus, into buffers in the absence and presence of a therapeutic protein currently under development at Lilly. The results demonstrate that the MCR is an ideal platform for evaluation of fast reactive systems and reactions that are particularly sensitive to small changes to process conditions. These conditions include heat inactivation of a virus in a mammalian cell culture process stream used in the manufacture of therapeutic proteins and antibodies. Biotechnol. Bioeng. 2008;99: 1384–1391. © 2007 Wiley Periodicals, Inc.
Escherichia coli‐based cell‐free synthesis of virus‐like particles
Authors: Bundy Bradley C. , Franciszkowicz Marc J. , Swartz James R.
Published: November 2007

Virus‐like particles (VLP) have received considerable attention for vaccine, drug delivery, gene therapy and material science applications. Although the number of unique VLP and their applications are rapidly growing, the positive impact of VLP applications is limited by the current diverse, expensive, and typically low‐yielding production technologies available. These technologies, when scaled, often result in structurally and compositionally inconsistent products. We present Escherichia coli‐based cell‐free protein synthesis as a production technology to overcome many of the limitations of current VLP production processes. Using this technique, the MS2 bacteriophage coat protein VLP was produced at a yield 14 times the best published production yield. Also, a C‐terminally truncated Hepatitis B core protein VLP was produced at similarly high yields (6 × 1013 VLP/mL). These VLP were found to have comparable characteristics to those produced in vivo. The scalability of this technology was tested without loss in production yields. To our knowledge, this is the first time a prokaryote‐based in vitro transcription/translation system has generated a virus‐like particle. Biotechnol. Bioeng. 2008;100: 28–37. Biotechnol. Bioeng. 2008;100: 28–37. © 2007 Wiley Periodicals, Inc.
Role of subsite +1 residues in pH dependence and catalytic activity of the glycoside hydrolase family 1 β‐glucosidase BGL1A from the basidiomycete Phanerochaete chrysosporium
Authors: Tsukada Takeshi , Igarashi Kiyohiko , Fushinobu Shinya , Samejima Masahiro
Published: November 2007

The basidiomycete Phanerochaete chrysosporium produces two glycoside hydrolase family 1 intracellular β‐glucosidases, BGL1A and BGL1B, during the course of cellulose degradation. In order to clarify the catalytic difference between two enzymes, in spite of their high similarity in amino acid sequences (65%), five amino acids around the catalytic site of BGL1A were individually mutated to those of BGL1B (V173C, M177L, D229N, H231D, and K253A), and the effects of the mutations on cellobiose hydrolysis were evaluated. When the kinetic parameters (Km and kcat) were compared at the optimum pH for the wild‐type enzyme, the kinetic efficiency was decreased in the cases of D229N, H231D, and K253A, but not V173C or M177L. The pH dependence of cellobiose hydrolysis showed a significantly more acidic pH profile for the D229N mutant, compared with the wild‐type enzyme. Since D229 is located between K253 and the putative acid/base catalyst E170, we prepared the double mutant D229N/K253A, and found that its hydrolytic activity at neutral pH was restored to that of the wild‐type enzyme. Our results indicate that the interaction between D229 and K253 is critical for the pH dependence and catalytic activity of BGL1A. Biotechnol. Bioeng. 2008;99: 1295–1302. © 2007 Wiley Periodicals, Inc.
High‐yield anthocyanin biosynthesis in engineeredEscherichia coli
Authors: Yan Yajun , Li Zhen , Koffas Mattheos A.G.
Published: November 2007

Anthocyanins are red, purple, or blue plant water‐soluble pigments. In the past two decades, anthocyanins have received extensive studies for their anti‐oxidative, anti‐inflammatory, anti‐cancer, anti‐obesity, anti‐diabetic, and cardioprotective properties. In the present study, anthocyanin biosynthetic enzymes from different plant species were characterized and employed for pathway construction leading from inexpensive precursors such as flavanones and flavan‐3‐ols to anthocyanins inEscherichia coli. The recombinantE. colicells successfully achieved milligram level production of two anthocyanins, pelargonidin 3‐O‐glucoside (0.98 mg/L) and cyanidin 3‐O‐gluside (2.07 mg/L) from their respective flavanone precursors naringenin and eriodictyol. Cyanidin 3‐O‐glucoside was produced at even higher yields (16.1 mg/L) from its flavan‐3‐ol, (+)‐catechin precursor. Further studies demonstrated that availability of the glucosyl donor, UDP‐glucose, was the key metabolic limitation, while product instability at normal pH was also identified as a barrier for production improvement. Therefore, various optimization strategies were employed for enhancing the homogenous synthesis of UDP‐glucose in the host cells while at the same time stabilizing the final anthocyanin product. Such optimizations included culture medium pH adjustment, the creation of fusion proteins and the rational manipulation ofE. colimetabolic network for improving the intracellular UDP‐glucose metabolic pool. As a result, production of pelargonidin 3‐O‐glucoside at 78.9 mg/L and cyanidin 3‐O‐glucoside at 70.7 mg/L was achieved from their precursor flavan‐3‐ols without supplementation with extracellular UDP‐glucose. These results demonstrate the efficient production of the core anthocyanins for the first time and open the possibility for their commercialization for pharmaceutical and nutraceutical applications. Biotechnol. Bioeng. 2008;100: 126–140. © 2007 Wiley Periodicals, Inc.
Optimization of spray‐drying conditions for the large‐scale preparation of Bacillus thuringiensis var. israelensis after downstream processing
Authors: Prabakaran G. , Hoti S.L.
Published: November 2007

Reduction of water activity in the formulations of mosquito biocontrol agent, Bacillus thuringiensis var. israelensis is very important for long term and successful storage. A protocol for spray drying of B. thuringiensis var. israelensis was developed through optimizing parameters such as inlet temperature and atomization type. A indigenous isolate of B. thuringiensis var. israelensis (VCRC B‐17) was dried by freeze and spray drying methods and the moisture content and mosquito larvicidal activity of materials produced by the two methods were compared. The larvicidal activity was checked against early fourth instars Aedes aegypti larvae. Results showed that the freeze‐dried powders retained the larvicidal activity fairly well. The spray‐dried powder moderately lost its larvicidal activity at different inlet temperatures. Between the two types of atomization, centrifugal atomization retained more activity than the nozzle type atomization. Optimum inlet temperature for both centrifugal and nozzle atomization was 160°C. Keeping the outlet temperature constant at 70°C the moisture contents for the spray‐dried powders through centrifugal atomization and freeze‐dried powders were 10.23% and 11.80%, respectively. The LC50 values for the spray‐dried and freeze‐dried powders were 17.42 and 16.18 ng/mL, respectively. Spore count of materials before drying was 3 × 1010 cfu/mL and after spray drying through nozzle and centrifugal atomization at inlet and outlet temperature of 160°C/70°C were 2.6 × 109 and 5.0 × 109 cfu/mL, respectively. Biotechnol. Bioeng. 2008;100: 103–107. © 2007 Wiley Periodicals, Inc.
Reporter gene assay against lipophilic chemicals based on site‐specific genomic recombination of a nuclear receptor gene, its response element, and a luciferase reporter gene within a stable HeLa cell line
Authors: Mori Tetsushi , Saito Fumiyo , Yoshino Tomoko , Takeyama Haruko , Matsunaga Tadashi
Published: November 2007

Genomic recombination was performed in a genetically modified stable HeLa cell line, HeLa55, using a uniquely designed donor vector harboring an exchange cassette comprised of the human glucocorticoid receptor (hGR) gene, its response element, and a luciferase reporter gene, to generate stable hGRLuc clones. After screening for cassette insertion, the selected stable clone, hGRLuc‐7, showed high integration stability of the exchange cassette over 20 passages with significantly high luciferase activity and fold inductions of up to 40‐ to 50‐fold. In addition, the cells were evaluated with synthetic glucocorticoid, dexamethasone, and a reasonable EC50 value of approximately 2.3 × 10−9 M was obtained. Strong and weak agonists, non‐responsive chemicals, and hGR antagonists were also evaluated in which the stable hGRLuc‐7 clone showed both high sensitivity and selectivity. The technology presented in this work is simple and reproducible, and shows great potential for the future development of genetically modified stable cell systems which are applicable in both fundamental and application researches of nuclear receptors. Biotechnol. Bioeng. 2008;99: 1453–1461. © 2007 Wiley Periodicals, Inc.
Effect of shear on performance and microbial ecology of continuously stirred anaerobic digesters treating animal manure
Authors: Hoffmann Rebecca A. , Garcia Marcelo L. , Veskivar Mehul , Karim Khursheed , Al‐Dahhan Muthanna H. , Angenent Largus T.
Published: November 2007

We determined the effect of different mixing intensities on the performance, methanogenic population dynamics, and juxtaposition of syntrophic microbes in anaerobic digesters treating cow manure from a dairy farm. Computer automated radioactive particle tracking in conjunction with computational fluid dynamics was performed to quantify the shear levels locally. Four continuously stirred anaerobic digesters were operated at different mixing intensities of 1,500, 500, 250, and 50 revolutions per min (RPM) over a 260‐day period at a temperature of 34 ± 1°C. Animal manure at a volatile solids (VS) concentration of 50 g/L was fed into the digesters daily at five different organic loading rates between 0.6 and 3.5 g VS/L day. The different mixing intensities had no effect on the biogas production rates and yields at steady‐state conditions. A methane yield of 0.241 ± 0.007 L CH4/g VS fed was obtained by pooling the data of all four digesters during steady‐state periods. However, digester performance was affected negatively by mixing intensity during startup of the digesters, with lower biogas production rates and higher volatile fatty acids concentrations observed for the 1,500‐RPM digester. Despite similar methane production yields and rates, the acetoclastic methanogenic populations were different for the high‐ and low‐intensity mixed digesters with Methanosarcina spp. and Methanosaeta concilii as the predominant methanogens, respectively. For all four digesters, epifluorescence microscopy revealed decreasing microbial floc sizes beginning at week 4 and continuing through week 26 after which no microbial flocs remained. This decrease in size, and subsequent loss of microbial flocs did not, however, produce any long‐term upsets in digester performance. Biotechnol. Bioeng. 2008;100: 38–48. © 2007 Wiley Periodicals, Inc.
Large‐Scale Synthesis of Single‐Crystalline RE2O3 (RE=Y, Dy, Ho, Er) Nanobelts by a Solid–Liquid‐Phase Chemical Route
Authors: Han Min , Shi Nai‐En , Zhang Wen‐Li , Li Bao‐Jun , Sun Jian‐Hua , Chen Kun‐Ji , Zhu Jian‐Ming , Wang Xin , Xu Zheng
Published: November 2007

Yttrium‐group heavy rare‐earth sesquioxide (RE2O3, RE=Y, Dy, Ho, Er) nanobelts were successfully fabricated by thermolysis of solid RE(NO3)3⋅x H2O in a dodecylamine/1‐octadecene mixed solvent system. The synthetic principle is based on separating the nucleation and growth processes by utilizing the poor solubility of RE(NO3)3⋅χ H2O in the solvent mixture and the heat‐transportation difference between the liquid and solid. By using dodecylamine, RE2O3 nanobelts can be readily obtained. X‐ray diffraction (XRD) analysis shows that the synthesized RE2O3 nanobelts are body‐centered cubic and crystalline. Field‐emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), selective‐area electron diffraction (SAED), and high‐resolution transmission electron microscopy (HR‐TEM) demonstrate that the synthesized RE2O3 compounds possess regular geometric structure (beltlike) with perfect crystallinity. Preliminary experimental results prove that the dodecylamine plays a key role in the formation of RE2O3 nanobelts and cannot be replaced by other surfactants. Furthermore, this method can be extended to the synthesis of RE2O3 nanobelt/metal nanocrystal nanocomposites and ABO3 (A=Y, Dy, Ho, Er; B=Al) and A3B5O12 (A=Y, Dy, Ho, Er; B=Al)‐type ternary oxide nanobelts, using mixed‐metal nitrate salts in the correct stoichiometry instead of single rare‐earth nitrates.
Titania‐Coated Platinum Thin Films by MOCVD: Electrochemical and Photoelectrochemical Properties
Authors: Daniele S. , Battistel D. , Gerbasi R. , Benetollo F. , Battiston S.
Published: November 2007

Pt films are deposited on glass rods from Pt(acac)2 and H2O in the thickness range 10–200 nm. Voltammetric measurements show that a 100 nm Pt film behaves like a bulk Pt electrode. A series of 100 nm Pt films are then coated with anatase TiO2 films 15–100 nm thick using Ti(OiPr)4 as the precursor. The electrochemical properties of the Pt–TiO2 electrodes, investigated by cyclic voltammetry in aqueous solutions, indicate that the passivating TiO2 layer induces some kinetic inhibitions into the heterogeneous electron transfer process of Ru(NH3)63+, which is utilized as a probe molecule. The photoelectrochemical performance of the Pt–TiO2 films demonstrates an optimum behavior for 100 nm TiO2 coatings. The photocatalytic properties of the Pt–TiO2 films can be exploited for electrocatalytic applications in sensor technology.
Optimization of the Vaporization of Liquid and Solid CVD Precursors: Experimental and Modeling Approaches
Authors: Maury F. , Duminica F.‐D. , Senocq F.
Published: November 2007

Two representative examples of the vapor phase transport of liquid and solid molecular precursors from a bubbler and a saturator, respectively, are presented. The influence of the vaporization conditions on the amount of vaporized precursor makes it possible to propose a model suitable for delivering high flow rates for, for instance, large‐scale reactors or continuous deposition in conveyor‐belt reactors. For the liquid compound Ti(OiPr)4 (TTIP) used in atmospheric pressure CVD of TiO2 thin films, the vapor flow rate increases linearly with the carrier gas flow rate up to a critical value, and also exponentially with the bubbler temperature. A numerical model is developed to simulate the experimental data. To illustrate the case of solid precursor, the sublimation of Fe(C5H5)2, used in the MOCVD of iron thin films, is studied. In this case, the amount of vaporized ferrocene is not proportional to the carrier gas flow rate. A model is developed for a powdery precursor, taking into account the gas/solid exchange surface and therefore the initial amount of precursor in the saturator. It can be used to predict the best vaporization conditions required to maximize and keep constant the precursor flow rate delivered to the CVD reactor.
Geographical clustering of eating disordered behaviors in U.S. high school students
Authors: Forman‐Hoffman Valerie L. , Cunningham Cassie L.
Published: November 2007

Objective:

The aim of this study was to determine if eating disorder behaviors geographically clustered among U.S high school students.

Method:

Our sample consisted of 15,349 high school students who responded to the 1999 Youth Risk Behavior Study (YRBS). Weight control and eating disordered behaviors under investigation included dieting, exercising, fasting, using diet pills, and purging to control weight in the last 30 days. We calculated pairwise odds ratios (PWORs) to determine the degree of within‐county clustering.

Results:

Among all participants, adjusted analyses revealed that having any weight control or eating disorder symptom, severe restricting, dieting, exercising, and diet pill use each showed significant clustering (p < .05). Purging did not significantly cluster by county. The magnitude of clustering was stronger for female students than male students.

Conclusion:

The significant clustering of weight control and eating disorder behavior in U.S. high school students confirms evidence of a social contagion effect of eating disorders. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2008
Organization of the Ru2Na Moiety of a Phenazine Ligand Into a New Coordination Network Promoted by ClO4–Aromatic‐π Interactions
Authors: Banerjee Priyabrata , Jana Atish Dipankar , Mostafa Golam , Goswami Sreebrata
Published: November 2007

A unique supramolecular network of the trimetallic building unit [(bpy)2Ru(LO)Na(LO)Ru(bpy)2](ClO4)5·3H2O {bpy = 2,2′‐bipyridine, LO = 7‐methoxy‐5‐(4‐methoxyphenyl)‐2,3‐bis(4‐methoxyphenylimino)‐3,5‐dihydro‐2H‐phenazin‐1‐one} is described. Crystal growth is driven by several synergistic intermolecular interactions including ClO4–π, π–π, C–H···π and hydrogen bonding. Optical properties of the supramolecule are modified due to aggregation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Bridged Dinuclear Tripodal Tris(amido)phosphane Complexes of Titanium and Zirconium as Diligating Building Blocks for Organometallic Polymers
Authors: Han Hua , Johnson Samuel A.
Published: November 2007

Appropriate bridging ligands allow for the preparation of bimetallic titanium and zirconium precursors to transition‐metal‐containing polymers using the formally trianionic P(CH2NArR)3 ligand (where ArR = Ph, and 3,5‐Me2C6H3 for a and b, respectively). Lithiation of the known amidophosphane ligand precursors P(CH2NHArR)3 (1a,b) with 3 equiv. of nBuLi cleanly provided the diethyl ether adducts P(CH2NArR)3Li3(OEt2)1.5 (2a,b). The THF adduct P(CH2NPh)3Li3(THF)5 (2a‐THF) was characterized by X‐ray crystallography. Protonolysis reactions were used to prepare the mononuclear titanium complexes P(CH2NArR)3TiOC6H4tBu (4a,b) and dinuclear species [P(CH2NPh)3TiNMe2]2‐μ‐4,4′{O[3,3′,5,5′‐(C6H2Me2)2]O} (5a), [P(CH2NPh)3Ti]2(μ‐O) (6a), and P(CH2N‐3,5‐Me2C6H3)3Ti‐μ‐O‐Ti(NMe2)3 (7b), from P(CH2NArR)3TiNMe2. The reactions of 1a,b with Zr(NEt2)4 afforded metal complexes of the type P(CH2NArR)3ZrNEt2 (8a,b). The chloride complexes P(CH2NArR)3ZrCl(THF) (9a,b) were prepared by treatment of HNEt3Cl with 1 or 2. The complexes 9a,b reacted with cyclopentadienyllithium (C5H5Li) to produce P(CH2NArR)3ZrCp (10a,b), which were also prepared by the reactions of the lithium salts 2a,b with CpZrCl3. The dilithium salt of the fulvalene dianion (Li2C10H8) reacts with 9a,b to produce the dinuclear complexes trans‐[P(CH2NArR)3Zr]2(μ‐η5:η5‐C10H8) (10a,b), respectively. The facile preparation of transition‐metal‐containing polymers from the bridged dinuclear complexes was illustrated by the reaction of 6a with half an equivalent of [Rh(CO)2(μ‐Cl)]2, which precipitated polymeric Cl(CO)Rh[P(CH2NPh)3Ti]2(μ‐O). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Stereoselective Synthesis of (2S,4R)‐4‐Hydroxypipecolic Acid
Authors: Occhiato Ernesto G. , Scarpi Dina , Guarna Antonio
Published: November 2007

A new synthetic route to enantiopure (2S,4R)‐4‐hydroxypipecolic acid from commercial ethyl (3S)‐4‐chloro‐3‐hydroxybutanoate is reported. The synthesis is based on the Pd‐catalyzed methoxycarbonylation of a 4‐alkoxy‐substituted δ‐valerolactam‐derived vinyl triflate followed by the stereocontrolled hydrogenation of the enamine double bond. The final product was obtained after exhaustive hydrolysis in 20 % yield over 10 steps. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Novel Electrochemical Microsensor for Hydrogen Peroxide based on Iron‐Ruthenium Hexacyanoferrate Modified Carbon Fiber Electrode
Authors: Pauliukaite Rasa , Hočevar Samo B. , Hutton Emily A. , Ogorevc Božidar
Published: November 2007

Novel electrochemical microsensor based on mixed iron‐ruthenium hexacyanoferrate (FeRuHCF) modified carbon fiber microelectrode (CFME) is presented for voltammetric and amperometric measurement of hydrogen peroxide at physiological pH. The FeRuHCF coating was electrochemically deposited using a one step procedure onto the substrate carbon fiber microelectrode by cycling the potential between 0.0 and +1.0 V (vs. Ag/AgCl) in a solution containing all precursor salts. The microsensor displayed good stability in neutral and alkaline media and had a nonstop working lifetime of up to 12 hours. The amperometric response time varied from 5 to 15 s depending on the hydrogen peroxide concentration level. The newly developed electrochemical microsensor exhibited a highly linear behavior in the examined concentration range from 5 to 1000 μmol L−1 (R2=0.999), an LoD (3σ) of 0.9 μmol L−1, and a favorable reproducibility with a calculated RSD of 2.9% (n= 6) for 100 μmol L−1 hydrogen peroxide, thus holding great promise for its further application in real samples and its exploitation in combination with biorecognition elements in advanced microbiosensor design.
Fibroblast nemosis arrests growth and induces differentiation of human leukemia cells
Authors: Kankuri Esko , Babusikova Olga , Hlubinova Kristina , Salmenperä Pertteli , Boccaccio Carla , Lubitz Werner , Harjula Ari , Bizik Jozef
Published: November 2007

Interactive signaling between cancer cells and stroma plays an important role in determining tumor development. We recently found tumor cell‐derived factors to induce fibroblast clustering, and that the high amounts of hepatocyte growth factor/scatter factor (HGF/SF) produced by these cell–cell contact‐activated fibroblasts enhanced the invasiveness of c‐Met‐expressing cancer cells. We now observed that leukemia cells lacking c‐Met respond to this novel type of fibroblast activation, nemosis, with growth arrest and differentiation to a dendritic cell‐like phenotype. This effect was counteracted by introduction of c‐Met expression into these cells. Moreover, those leukemia cell lines harboring properly processed c‐Met showed no effect in response to nemosis. We propose this effect to be mediated by nemosis‐derived cytokine signals, and present the potential candidates induced in the nemotic fibroblasts: interleukins‐1, ‐6, ‐8, ‐11, leukemia inhibitory factor and granulocyte‐macrophage‐colony‐stimulating factor. Our results emphasize the role of activated stromal fibroblasts in controlling progression of certain hematologic malignancies in a c‐Met expression‐dependent manner. © 2007 Wiley‐Liss, Inc.
Differences in antitumor effects of various statins on human pancreatic cancer
Authors: Gbelcová Helena , Leníček Martin , Zelenka Jaroslav , Knejzlík Zdeněk , Dvořáková Gabriela , Zadinová Marie , Poučková Pavla , Kudla Michal , Balaž Peter , Ruml Tomáš , Vítek Libor
Published: November 2007

Statins are widely used for the treatment of hypercholesterolemia. However, their inhibitory action on HMG‐CoA reductase also results in the depletion of intermediate biosynthetic products, which importantly contribute to cell proliferation. The aim of the present study was to compare the effects of the individual commercially available statins on experimental pancreatic cancer. The in vitro effects of individual statins (pravastatin, atorvastatin, simvastatin, lovastatin, cerivastatin, rosuvastatin and fluvastatin) on the viability of human pancreatic cancer were evaluated in CAPAN‐2, BxPc‐3 and MiaPaCa‐2 cell lines. The in vivo experiments were performed on nude mice xenotransplanted with CAPAN‐2 cells. The mice received oral treatments either with a placebo, or with the statins mentioned earlier in a daily dose corresponding to a hypocholesterolemic dose in humans. The effect of these statins on the intracellular Ras protein, trafficking in MiaPaCa‐2 transfected cells, was also investigated. Substantial differences in the tumor‐suppressive effects of all statins were detected in both in vitro and in vivo experiments. While simvastatin exerted the highest tumor‐suppressive effects in vitro, rosuvastatin (p = 0.002), cerivastatin (p = 0.002) and fluvastatin (p = 0.009) were the most potent compounds in an animal model. All statins (except pravastatin) inhibited intracellular Ras protein translocation. In summary, substantial tumor‐suppressive effects of various statins on the progression of experimental pancreatic adenocarcinoma were demonstrated, with marked differences among individual statins. These results support greatly the potential of statins for the chemoadjuvant treatment of pancreatic cancer. © 2007 Wiley‐Liss, Inc.
Stabilization of cellular properties and differentiation mutilpotential of human mesenchymal stem cells transduced with hTERT gene in a long‐term culture
Authors: Huang Guoping , Zheng Qiang , Sun Jie , Guo Chunjuan , Yang Jinfeng , Chen Rui , Xu Yuling , Wang Guozhong , Shen Dan , Pan Zhijun , Jin Jie , Wang Jinfu
Published: November 2007

Human bone marrow mesenchymal stem cells (hMSCs) are promising candidates for cell therapy and tissue engineering. The life span of hMSCs during in vitro culture is limited. Human telomerase catalytic subunit (hTERT) gene transduction can prolong the life span of hMSCs and maintain their potential of osteogenic differentiation. We established a line of hMSCs transduced with exogenous hTERT (hTERT‐hMSCs) and investigated its sustaining cellular properties in a long‐term culture. This line of hTERT‐hMSCs was cultured for 290 population doublings (PDs) without loss of contact inhibition. Under adipogenic, chondrogenic and osteogenic induction, hTERT‐hMSCs at PD 95 and PD 275 could differentiate respectively into adipocytes, chondrocytes, and osteocytes. hTERT‐hMSCs at these PDs showed no transforming activity through both in vitro assay of cell growth in soft agar and in vivo assay of tumorigenicity in NOD‐SCID mice. Karyotype analyses showed no significant chromosomal abnormalities in hTERT‐hMSCs at these PDs. These results suggested that the hTERT‐hMSCs at lower population doubling levels (PDLs) should be considered as a cell model for studies of cellular senescence, differentiation and in vitro tissue engineering experiment because of its prolonged life span and normal cellular properties. J. Cell. Biochem. 103: 1256–1269, 2008. © 2007 Wiley‐Liss, Inc.
Lysophosphatidic acid in malignant ascites stimulates migration of human mesenchymal stem cells
Authors: Lee Mi Jeong , Jeon Eun Su , Lee Jung Sub , Cho Mong , Suh Dong‐Soo , Chang Chulhun L. , Kim Jae Ho
Published: November 2007

Lysophosphatidic acid (LPA) is elevated in ascites of ovarian cancer patients and is involved in growth and invasion of ovarian cancer cells. Accumulating evidence suggests a pivotal role of mesenchymal stem cells (MSCs) or stromal cells in tumorigenesis. In the present study, we demonstrated that ascites from ovarian cancer patients and LPA increased migration of human MSCs. The migration of MSCs induced by LPA and malignant ascites was completely abrogated by pretreatment with Ki16425, an antagonist of LPA receptors, and by silencing of endogenous LPA1, but not LPA2, with small interference RNA, suggesting a key role of LPA played in the malignant ascites‐induced migration. LPA induced activation of ERK through pertussis toxin‐sensitive manner, and pretreatment of MSCs with U0126, a MEK inhibitor, or pertussis toxin attenuated the LPA‐induced migration. Moreover, LPA induced activation of RhoA in MSCs, and pretreatment of the cells with Y27632, a Rho kinase inhibitor, markedly inhibited the LPA‐induced migration. In addition, LPA and malignant ascites increased intracellular concentration of calcium in MSCs, and Ki16425 completely inhibited the elevation of intracellular calcium. These results suggest that LPA is a crucial component of the malignant ascites which induce the migration of MSCs and elevation of intracellular calcium. J. Cell. Biochem. 104: 499–510, 2008. © 2007 Wiley‐Liss, Inc.
Tweaking the hinge and caps: testing a model of the organization of jaws
Authors: Depew Michael J. , Compagnucci Claudia
Published: November 2007

Historically, examinations of gnathostome skulls have indicated that for essentially the entirety of their existence, jaws have been characterized by a high degree of fidelity to an initial basic structural design that will then go on to manifest an amazing array of end‐point phenotypes. These two traits—bauplan fidelity and elaboration of design—are inter‐connected and striking, and beg a number of questions, including: Are all jaws made in the same manner and if not how not? To begin to tackle such questions, we herein operationally define jaws as two appositional, hinged cranial units for which polarity and potential modularity are characteristics, and then address what is necessary for them to form, including delineating both the sources of cells and tissues that will formally yield the jaws as well as what informs their ontogeny (e.g., sources of positional information and factors directing the interpretation of developmental cues). Following on this, we briefly describe a predictive, testable model of jaw development (the “Hinge and Caps” model) and present evidence that theSatb2+cell population in the developing jaw primordia of mice defines a developmentally and evolutionarily significant jaw module such as would be predicted by the model.J. Exp. Zool. (Mol. Dev. Evol.) 310B:315–335, 2008. © 2007 Wiley‐Liss, Inc.
Sequence‐specific inhibition of RNA polymerase III‐dependent transcription using Zorro locked nucleic acid (LNA)
Authors: Ge Rongbin , Svahn Mathias G. , Simonson Oscar E. , Mohamed Abdalla J. , Lundin Karin E. , Smith C. I. Edvard
Published: November 2007

Background

RNA polymerase III (pol III)‐dependent transcripts are involved in many fundamental activities in a cell, such as splicing and protein synthesis. They also regulate cell growth and influence tumor formation. During recent years vector‐based systems for expression of short hairpin (sh) RNA under the control of a pol III promoter have been developed as gene‐based medicines. Therefore, there is an increasing interest in means to regulate pol III‐dependent transcription. Recently, we have developed a novel anti‐gene molecule ‘Zorro LNA (Locked Nucleic Acid)’, which simultaneously hybridizes to both strands of super‐coiled DNA and potently inhibits RNA polymerase II‐derived transcription. We have now applied Zorro LNA in an attempt to also control U6 promoter‐driven expression of shRNA.

Methods

In this study, we constructed pshluc and pshluc2BS plasmids, in which U6 promoter‐driven small hairpin RNA specific for luciferase gene (shluc) was without or with Zorro LNA binding sites, respectively. After hybridization of Zorro LNA to pshluc2BS, the LNA‐bound plasmid was cotransfected with pEGFPluc into mammalian cells and into a mouse model. In cellular experiments, cotransfection of unhybridized pshluc2BS, Zorro LNA and pEGFPluc was also performed.

Results

The results showed that the Zorro LNA construct efficiently inhibited pol III‐dependent transcription as an anti‐gene reagent in a cellular context, including in vivo in a mouse model.

Conclusions

Thus, this new form of gene silencer ‘Zorro LNA’ could potentially serve as a versatile regulator of pol III‐dependent transcription, including various forms of shRNAs. Copyright © 2007 John Wiley & Sons, Ltd.
The teacher as leader: The relationship between emotional intelligence and leadership effectiveness, commitment, and satisfaction
Authors: Iordanoglou Dimitra
Published: November 2007

Emotional intelligence has emerged in the past decade as one of the crucial components of leadership effectiveness in many different contexts. The present study aimed at examining the relationships among emotional intelligence, leadership effectiveness, commitment, and satisfaction in education. Three hundred thirty‐two primary education teachers participated in the study conducted in Greece. Results, using structural equation modeling, showed that emotional intelligence, especially the intrapersonal and interpersonal dimensions, has a positive effect on leadership roles, explaining 51% of variance. A strong positive effect was also apparent on teachers' commitment and effectiveness, as measured by teachers' perception. Leadership roles such as performance evaluation, motivation support, and development improvement had a strong influence on effectiveness. The findings could have implications for the selection and training of future educators.
Sealing of open dentinal tubules by laser irradiation: AFM and SEM observations of dentine surfaces
Authors: Kubínek Roman , Zapletalová Zdenka , Vůjtek Milan , Novotný Radko , Kolářová Hana , Chmelíčková Hana , Peřina Jan
Published: November 2007

Dentin of human teeth is a vital hydrated tissue. It is strongly sensitive to dehydration and drying that are commonly used in preparation of samples for scanning electron microscopy. Experience in examination of dentine surfaces of extracted human third molars using contact mode atomic force microscopy under moist conditions is described. The examined dentine surfaces are modified by laser radiation produced by a pulsed Nd:YAG laser that leads to sealing of open dentinal tubules under suitable conditions that are reached after covering dentine surfaces with dye agents. Out of four investigated dye agents erythrosin solution in water has been found the most suitable and the lower and upper limits of pulse energies for sealing of dentinal tubules have been set. Copyright © 2007 John Wiley & Sons, Ltd.
Erratum: Engineering a circularly permuted GFP scaffold for peptide presentation
Authors: Paschke Matthias , Tiede Christian , Höhne Wolfgang
Published: November 2007

Engineering a circularly permuted GFP scaffold for peptide presentation

Matthias Paschke, Christian Tiede, Wolfgang Höhne.

Volume 20, Issue 5, Pages 367–378 (September/October 2007) DOI: 10.1002/jmr.844.

The above paper was published with an incorrect affiliation of the co‐authors. The correct address is as follows:

Institut für Biochemie, Charité‐Universitätsmedizin Berlin, Monbijoustrasse 2a, D‐10117 Berlin, Germany
Evaluation of the Physical‐Chemical Properties of Poly(ethylene oxide)‐block‐Poly(propylene oxide) by Different Characterization Techniques
Authors: Mansur Claudia , Spinelli Luciana , González Gaspar , Lucas Elizabete F.
Published: November 2007

Summary: A surfactant's efficiency for a given application is dependent on its chemical structure and physical‐chemical properties in solution, including surfactant solubility as a function of concentration and temperature as well as adsorption and aggregation behavior. This review work describes the main physical‐chemical properties ascertained by means of various characterization techniques, which can be used to study nonionic surfactants based on poly(ethylene oxide)‐block‐poly(propylene oxide) (PEO‐PPO). Among these, some are widely used and others are relatively new for this type of application.
Synthesis and Characterization of a Biocompatible Copolymer to be Used as Cell Culture Support
Authors: Becerra Natalia , Restrepo Luz Marina , López Betty Lucy
Published: November 2007

Summary: N‐isopropylacrylamide (NIPAAm)/butylacrylate (BAc) copolymer was synthesized by emulsion polymerization in order to use it as a cell culture surface for corneal epithelium biosubstitutes. Results showed that the obtained polymers were thermosensitive hydrogels. The copolymer was characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and swelling degree. 3T3 Swiss cells were used as feeder layers and they were used to test the cytotoxic effect of the hydrogels. The conditions to isolate, cultivate, expand and cryo‐preserve human oral mucosal cells were established and analysis of several morphological and immuno‐histochemical characteristics of the cultivated oral mucous were made.
Functionalization of Biodegradable Polyester for Tissue Engineering Applications
Authors: Thiré Rossana M. S. M. , Meiga Taíla O. , Dick Sabrina , Andrade Leonardo R.
Published: November 2007

Summary: Chemical modification of polymer surface may potentially be used to create smart materials that can guide cellular adhesion, proliferation and maintenance of specific expression of molecules. The microbial polyester poly (3‐hydroxybutyrate) (PHB) has been attracted attention as promising material for applications in tissue engineering. In this work, a wet‐chemical method, base ethylenediamine aminolysis, was performed to improve the adhesion of chondrocytes isolated from human articular cartilage to PHB films. The effects of chemical treatment on PHB films was evaluated by following changes in morphology and surface chemical composition using atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS), respectively. While the effect on cells morphology was studied by scanning electron microscopy (SEM). The treatment with ethylenediamine did not change significantly the morphology of the structures of PHB films surface. However, the roughness of the aminolyzed films was slightly higher. The introduction of nitrogen‐containing groups was confirmed by XPS. In vitro experiments indicated that the surface modification did not have toxic effects in cells, since they could adhere and proliferate on modified PHB films. It was observed that long‐time treatment improved ability of PHB films to support cell growth, which could be accounted to physicochemical and topological effects.