bluuebunny/crossref_metadata_2025 huggingface dataset:
Total Synthesis, Molecular Editing and Evaluation of a Tripyrrolic Natural Product: The Case of “Butylcycloheptylprodigiosin”
Authors: Fürstner Alois , Radkowski Karin , Peters Hartwig , Seidel Günter , Wirtz Conny , Mynott Richard , Lehmann Christian W.
Published: January 2007

Conflicting reports are found in the literature on whether the ortho‐pyrrolophane derivative 6, which has been named “butylcycloheptylprodigiosin” even though it is a cyclononane derivative, is a natural product or merely a mis‐assigned structure. This dispute has now been resolved by an unambiguous total synthesis of this complex alkaloid which confirms the initial structure assignment. The chosen approach is largely catalysis‐based, featuring the first application of a “Narasaka–Heck” reaction in natural product chemistry. This palladium‐catalyzed transformation allows the unsaturated oxime ester 26 to be converted into the bicyclic dihydropyrrole 27. Other notable reactions of the reported approach to 6 are a regioselective Tsuji–Trost reaction of the doubly allylic acetate 21 with methyl acetoacetate, a base‐induced aromatization of 27 to the corresponding pyrrole 28, a chemoselective oxidation of the benzylic methyl group in 33 with cerium ammonium nitrate in a biphasic reaction medium that does not affect the labile pyrrole nucleus, and a Suzuki cross‐coupling for the completion of the heterocyclic domain. Diversification in the latter step leads to a set of analogues that differ from the natural product in the terminal (hetero)arene ring. This structural modification results in complete loss of the very pronounced ability of the parent compound 6 to induce oxidative cleavage in double stranded DNA in the presence of CuII. Several cyclononane‐, cyclononene‐ and cyclononadiene derivatives prepared en route to 6 have been characterized by crystal structure analysis, allowing the conformational behavior of nine‐membered carbocycles to be studied.
Molecular dynamics study of the conformational dynamics and energetics of some large‐ring cyclodextrins (CDn, n = 24, 25, 26, 27, 28, 29)
Authors: Gotsev Martin G. , Ivanov Petko M. , Jaime Carlos
Published: January 2007

Molecular dynamics simulations in water solution were performed on six large‐ring cyclodextrins (LR‐CDs) with a degree of polymerization 24, 25, 26, 27, 28, and 29. The AMBER parm99 force field and explicit water molecules (TIP3P) were used in the simulations. The present research was aimed at further extending our knowledge on the structural dynamics and the energetics of this new class of compounds that may eventually provide chiral cavities suitable for formation of inclusion complexes with small molecules, and, accordingly, to serve as host structures for chiral recognition. The study focused on several representatives flanking CD26—the largest LR‐CD for which X‐ray data is available. Both the monitoring of the structural variations during the simulations as well as the analyses of energy balances are indicative for high flexibility of the macrorings. Slight differences of the overall preferred shapes were detected with diminishing the size of the macromolecules from CD29 to CD24. An elongated cavity (CD28) or a double parallel strand in different specific representations are the dominating motifs in the LR‐CDs studied: with loops at the two ends (CD25, CD28, CD29), with a loop at one end (CD25), twisted (CD26, CD27) or twisted with an open portion in the middle (CD24), helical (CD24, CD25), or linking two loops from one of their sides (CD27). Two loops connected by an arc (CD28, CD29) and a cavity with the shape of an extended rectangular (CD24, CD28) appear preferentially during the conformational interconversions of the two larger CDs, whereas helical motifs are present in the smaller macrorings: an extended helix with ends linked by an arc (CD24), helical turn and helical portion (CD26, CD27). A triple propeller conformation or three symmetrical loops of almost equal size were also detected for CD26 and CD29, respectively. The present results further support the hypothesis for the existence of more than one cavity in large‐ring cyclodextrins and suggest preferred conformations in water solution for the LR‐CDs with degree of polymerization from 24 to 29. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Evidence for multiple signaling pathways in single squid olfactory receptor neurons
Authors: Mobley Arie Sitthichai , Mahendra Gandham , Lucero Mary T.
Published: January 2007

At least two different G‐protein‐mediated transduction cascades, the adenylate cyclase and phospholipase C (PLC) pathway, process chemosensory stimuli for various species. In squid olfactory receptor neurons (ORNs), physiological studies indicate that both pathways may be present; however, confirmation of the transduction molecules at the protein level is absent. Here we provide evidence that the G‐proteins involved in both adenylate cyclase and PLC pathways are present in squid ORNs (Lolliguncula brevis). We used immunoblotting to show that Gαolf, Gαq, and a downstream effector, enzyme PLC140, are present in the squid olfactory epithelium (OE). To localize these proteins to one or more of the five morphological cell types described for squid OE, paraformaldehyde‐fixed olfactory organs were cryosectioned (10 μm), double‐labeled for Gαolf, Gαq, or PLC140, and imaged. Analysis of serial sections from entire olfactory organs for epithelial area and patterns of immunofluorescence revealed a region of highest immunoreactivity at the anterior half of the organ. At the cellular level, type 1 cells could not be distinguished morphologically and were not included in the analysis. The three labeling patterns observed in type 2 cells were Gαq alone, PLC140 alone, and colocalization of Gαq and PLC140. Subsets of cell types 3, 4, and 5 showed colocalization of Gαolf with Gαq but not with PLC140. These data suggest that the PLC pathway predominates in type 2 cells; however, coexpression of Gαolf with Gαq in cell types 3, 4, and 5 suggests that both pathways may participate in olfactory transduction in non‐type 2 squid ORNs. J. Comp. Neurol. 501:231–242, 2007. © 2007 Wiley‐Liss, Inc.
Behavior of Ni‐Doped MgMoO4 Single‐Phase Catalysts for Synthesis of Multiwalled Carbon Nanotube Bundles
Authors: Li Y. , Zhang X. , Geise H. J. , van Tendeloo G.
Published: January 2007

A significant effect is found when various ratios of CH4/H2 and CH4/N2 are used for the synthesis of multiwalled carbon nanotube (MWNT) bundles on nickel‐doped MgMoO4 (Ni/Mo/MgO) as a catalyst. The absorption of hydrogen makes the nickel–molybdenum nanoparticles highly dispersed on the porous MgO, and the synergism of nickel–molybdenum has the effect that sufficient carbon atoms are rapidly dissolved in the molten nickel‐molybdenum nanoparticles, leading to a high yield of MWNTs. The phase transformations of the catalysts and the formation mechanism of the MWNT bundles on Ni/Mo/MgO catalyst are also presented.
CVD‐Fabricated Aluminum Oxide Coatings from Aluminum tri‐iso‐propoxide: Correlation Between Processing Conditions and Composition
Authors: Gleizes A. N. , Vahlas C. , Sovar M.‐M. , Samélor D. , Lafont M.‐C.
Published: January 2007

This paper presents results on aluminum oxide thin films processed using metal–organic (MO) CVD from aluminum tri‐iso‐propoxide (ATI) without any additional oxygen source, in the temperature range 623–973 K. The films do not diffract X‐rays, except when grown at 973 K or annealed at 1073 K. Their composition was investigated using several techniques; electron probe micro analysis (EPMA), energy dispersive X‐ray spectroscopy (EDX), elastic recoil detection analysis (ERDA), and Rutherford back‐scattering spectroscopy (RBS). It corresponds to the formula AlO(OH) for those grown at 623 K. The composition of films prepared above 688 K corresponds to the formula Al2O3. Between 623 K and 688 K, partly hydroxylated films are obtained. This is confirmed by Fourier transform infrared (FTIR) transmission spectroscopy (no OH absorption band in the 3500 cm–1 region for films prepared above 688 K), and by thermogravimetric analysis (TGA, DTG) (no significant mass loss for films prepared above 688 K). Observations using the transmission electron microscopy (TEM) showed that films prepared at 623 K are amorphous, while those prepared at 973 K are nanocrystalline. In both cases, γ‐Al2O3 crystals are formed and progressively grow on exposure to the TEM electron beam. Knowing the correlation between processing conditions and the composition of such films should help optimize the process with regards to any aimed property of use.
Thermomechanical Properties of Parylene X, A Room‐Temperature Chemical Vapor Depositable Crosslinkable Polymer
Authors: Senkevich J. J. , Woods B. W. , McMahon J. J. , Wang P.‐I
Published: January 2007

Poly(p‐xylylene) has existed commercially for many years but has never gained widespread acceptance due to its poor thermal and optical properties. Parylene X, a new chemical vapor depositable polymer on the same process platform as poly(p‐xylylene), is a copolymer of poly(ethynyl‐p‐xylylene) and poly(p‐xylylene). It exhibits thermal stability to at least 420 °C, has a low coefficient of thermal expansion of 55 ppm after it is crosslinked, and exhibits low stress. It possesses a glass transition temperature of 73 °C and starts to crosslink at ∼160 °C with a peak isotherm at 250 °C. The ethynyl functional groups crosslink to form the very stable phenyl moiety.
Deposition of Palladium Nanodots of Controlled Size and Density onto Surface‐Modified SiO2 Particles by an Atmospheric Pressure CVS/MOCVD Process
Authors: Binder A. , Heel A. , Kasper G.
Published: January 2007

A continuous gas‐phase process under atmospheric pressure for tailoring Pd/SiO2 catalyst particles is described and characterized. Emphasis is placed on controlling the size and number density of Pd nanodots on the surface of the carrier particle. In the first step, sub‐micrometer‐sized SiO2 support particles are generated continuously in a flow reactor by chemical vapor synthesis (CVS) from tetraethyl(ortho)silicate (TEOS). A process‐integrated method is described to vary the surface concentration of hydroxyl groups on the SiO2 between about 1 and 6 OH groups per nm2, by adjusting the synthesis conditions. In a second step, Pd nanodots are deposited onto the SiO2 by metal–organic (MO)CVD of Cp(allyl)Pd [(η3‐allyl)(η5‐cyclopentadienyl)palladium]. The median diameter of the Pd nanodots was varied between about 1.3 and 3 nm (σg ∼1.2) by adjusting the precursor concentration in the gas phase. It is shown that the number density of the Pd islands varied in proportion to the density of hydroxyl groups on the SiO2 in the range 0‐12 Pd islands per 100 nm2 of carrier particle surface.
A Passion for Publishing
Authors: Hitchman Michael L.
Published: January 2007

2007 marks the bicentennial of John Wiley & Sons' publishing business. In this editorial, the Editor takes a brief look back in time, examining the history and origins of a technique that would come to be known as chemical vapor deposition, and comments on the journal's rise to being the forum of choice for publishing the best research in this industrially and academically important field.
The Synthesis, Crystal and Band Structures, and Properties of the Quaternary Supramolecular Complexes [Hg6Z4](MX6)Hgy (Z = As, Sb; M = Hg, Cd; X = Cl, Br, I; y = 0, 0.5, 0.6)
Authors: Zou Jian‐Ping , Li Yan , Fu Ming‐Lai , Guo Guo‐Cong , Xu Gang , Liu Xue‐Hui , Zhou Wei‐Wei , Huang Jin‐Shun
Published: January 2007

The series of supramolecular complexes (Hg6As4)(CdCl6)Hg0.5 (1), (Hg6As4)(HgCl6)Hg0.5 (2), (Hg6As4)(CdBr6) (3), and (Hg6Sb4)(CdI6)Hg0.6 (4) has been prepared by a solid‐state reaction and their crystal structures determined by single‐crystal X‐ray diffraction. All these compounds crystallize in the space group Pa$\bar {3}$ with four formula units in a cell: a = 12.172(2) (1), 12.189(1) (2), 12.3738(5) (3), and 13.234(2) Å (4). Their structures feature a 3D cationic host framework that is built up of linearly coordinated mercury and tetrahedrally coordinated pnicogen atoms to form distorted As2Hg6 or Sb2Hg6 octahedra, and discrete guest anions. The distorted octahedra corner‐share with each other to form a perovskite‐like, 3D cationic framework that possess two types of closed cavities with different sizes. The octahedral guest anions (MX6)4– are embedded in the larger cavities, whereas the smaller cavities trap the excess mercury atoms or remain empty. The optical properties were investigated by diffuse reflectance and FT IR spectroscopy. The electronic band structures and density of states (DOS) calculated by DFT methods indicate that the present compounds are semiconductors and that the optical absorption mainly originates from the charge transitions from the p orbital of the pnicogen (As or Sb) and halogen (Cl, Br or I) atoms states to the Hg1 6s states for 1, 3, and 4, and to Hg1 6s and Hg3 6sstates for 2.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Developing an Iridium Oxide Film Modified Microelectrode for Microscale Measurement of pH
Authors: Li Jianping , Du Yalin , Fang Cheng
Published: January 2007

Iridium oxide film modified microelectrode was fabricated by anodic oxidation method onto the tip of an etched iridium wire in diluted sulfuric acid solution by cyclic voltammetry. The iridium oxide film microelectrode exhibited very promising pH sensing performance, with an ideal Nernstian in the tested pH range of 0 to 14. This method for preparing microelectrode allowed accurately control of the deposited amount and the rate of the iridium oxide film growth. The electrodes demonstrated advantages of long lifetime, good selectivity and fast response with a relative time less than 0.2 s for pH changes in a large scale. The microelectrode was not interfered by a wide variety of inorganic ions and organic compounds. Furthermore, the electrodes were successfully applied to the measurement of pH in microscale of apples.
Flexible Ultrathin PolyDVB/EVB Composite Membranes for the Optimization of a Whole Blood Glucose Sensor
Authors: Bridge Kerry , Davis Frank , Collyer Stuart , Higson Séamus P. J.
Published: January 2007

An ultrathin composite membrane has been developed as the outer covering barrier in a model amperometric glucose oxidase enzyme electrode. The membrane was formed by cathodic electropolymerization of divinylbenzene/ethylvinylbenzene at the surface of a gold coated polyester support membrane. Permeability coefficients were determined for O2 and glucose across membranes with a range of polymer thicknesses. Anionic interferents (such as ascorbate), were screened from the working electrode via a charge exclusion mechanism. The enzyme electrode showed an initial 10% signal drift when first exposed to whole human blood over a period of 2 hours, after which responses remained essentially stable. Whole blood patient glucose determinations yielded a correlation coefficient of r2=0.99 compared to standard hospital analyses.
Uppsalator's acceleration
Authors: Pastushenko Vassili Ph.
Published: January 2007

Semiquantitative prediction of the Uppsalator (electroosmotical oscillator developed in Uppsala) under constant voltage is confirmedvianumerical solution of exact nonlinear integro‐differential equations in partial derivatives (PDE). Critical voltage and characteristic features of pressure and liquid flow velocity as functions of time are reproduced with high precision. In particular, the number of inflection pointsperperiod of oscillating velocity increases with growing voltage from two to six. A new feature is demonstrated. For sufficiently high voltages the Uppsalator shows normal deceleration,i.e., the oscillation period grows with voltage. However, in some supercritical range of voltages, acceleration is observed, as expressed by decrease of the oscillation period with growing voltage. Thus, the Uppsalator at constant voltage considered earlier as an impossible phenomenon represents a great challenge for experimental verification.
A dynamic molecular probe to investigate catalytic effects and Joule heating in enantioselective MEKC
Authors: Trapp Oliver
Published: January 2007

Enantiomerization of ferroin [tris(1,10‐phenanthroline)‐iron(II)‐complex] was investigated by enantioselective dynamic micellar EKC. The enantiomer separation was performed in an aqueous 50 mM sodium borate/sodium dihydrogenphosphate buffer at pH 8.0 in the presence of the chiral surfactant sodium cholate. The unified equation of dynamic chromatography was employed to determine reaction rate constants from the electropherograms featured with distinct plateau formation. Activation parameters ΔH≠ = 124.0 ± 0.5 kJ/mol and ΔS≠ = 121 ± 1 J·K−1mol−1 were calculated from temperature‐dependent measurements between 10.0 and 27.5°C in 2.5 K steps. Considering the data obtained by polarimetry of enantiomeric pure ferroin in water, it was found that enantiomerization rate in the micelle is accelerated by a factor of 12. Because of the highly positive activation entropy ΔS≠, ferroin was used as a temperature‐sensitive dynamic molecular probe to determine temperature deviations caused by Joule heating.
Investigation of hormone activity in butterfly imaginal wing discs by protein expression pattern changes
Authors: Cieslak Alexandra , Vogler Alfried P. , Lafranchi‐Tristem Nathalie , Dunn Michael J. , Westbrook Jules A.
Published: January 2007

In a proteomic approach using 2‐DE, the changes in protein expression patterns in wing imaginal discs induced by hormone treatment have been studied. Here we show the response of butterfly imaginal wing disc tissue taken from late fifth instar larvae of the African‐Mocker swallowtail Papilio dardanus (Lepidoptera) to the insect hormones 20‐hydroxyecdysone (20‐HE) and juvenile hormone (JH). The tissues were cultured in the presence of one hormone or a combination of both and their protein expression was compared to the pattern obtained from untreated wing discs. All the treatments resulted in changes in the expression pattern distinct from the uninduced control, indicating a distinct protein regulation induced by the hormones. The treatment with both of the hormones, which are known to have antagonistic physiological effects, did show a unique pattern, presumably the result, in part, of synergistic effects on protein expression mediated by the combined effects of both the hormones. The extent of the interaction between JH and 20‐HE indicates a complex molecular regulation, far beyond a simple antagonistic effect.
Shotgun electroelution: A proteomic tool for simultaneous sample elution from whole SDS‐polyacrylamide gel slabs
Authors: Antal József , Bányász Borbála , Buzás Zsuzsanna
Published: January 2007

A high‐throughput device has been constructed which allows parallel electroelution of separated SDS‐protein bands directly from intact unsectioned polyacrylamide gel slabs as well as single electroelution of certain protein spots into a 384‐well standard flat‐bottom multiwell plate. The prototype provides complete, quick elution for proteomics from 1‐D or from 2‐D gels without gel sectioning. Since the elution chamber matrix requires no assembly, sample handling can be easily carried out by existing robotic workstations. The current design is a good candidate for automation of spot elution since there are no moving liquid containing components in the apparatus. Eight SDS‐proteins were eluted in test runs and an average 70% sample recovery was achieved by re‐electrophoresis of the electroeluates.
pH transients during salt removal in isoelectric trapping separations: A curse revisited
Authors: Shave Evan , Vigh Gyula
Published: January 2007

The pH transients that occur during isoelectric trapping separations as a result of the removal of nonampholytic ionic components have been re‐examined. Salts containing strong electrolyte anions and cations, both with equal and dissimilar mobilities, have been studied using anodic and cathodic buffering membranes whose pH values were both equidistant and nonequidistant from pH 7. The direction and magnitude of the pH transient (acidic or basic) was found to depend on both the mobilities of the anion and cation (μanion/μcation) and the pH difference between pH 7 and the pH of the buffering membranes (|pHmembanodic − 7|/|7 − pHmembcathodic|). When |pHmembanodic − 7|/|7 − pHmembcathodic| = 1, μanion/μcation<1 leads to an acidic pH transient, μanion/μcation = 1 eliminates the pH transient and μanion/μcation>1 leads to a basic pH transient. When μanion/μcation = 1, |pHmembanodic − 7|/|7 − pHmembcathodic|<1 leads to a basic pH transient, |pHmembanodic − 7|/|7 − pHmembcathodic| = 1 eliminates the pH transient and |pHmembanodic − 7|/|7 − pHmembcathodic|>1 leads to an acidic pH transient. By selecting appropriate anodic and cathodic buffering membranes to adjust the |pHmembanodic − 7|/|7 − pHmembcathodic| value, pH transients caused by dissimilar anion and cation mobilities can be avoided.
Control system for the switched reluctance drive of a flywheel energy‐storage module
Authors: Vázquez C. , Lafoz M. , Ugena D. , García‐Tabarés L.
Published: January 2007

This paper presents a novel control system for the operation of a flywheel energy‐storage (FES) module used for power peak shaving in high‐speed railway substations. A double power converter drives a switched reluctance machine (SRM) along with a flywheel operating in a wide speed range. An innovative controller architecture based on modular microcontrolled boards connected through a CAN network is introduced. Standard switching patterns are modified to reduce iron and semiconductor losses and to improve harmonic performance. Experimental results for a 140 kW/5 MJ prototype are presented confirming controller compliance with the system specifications and requirements. Copyright © 2007 John Wiley & Sons, Ltd.
A finite element model for free surface flows on fixed meshes
Authors: Coppola‐Owen A. H. , Codina R.
Published: January 2007

In this paper, we present a finite element model for free surface flows on fixed meshes. The main novelty of the approach, compared with typical fixed mesh finite element models for such flows, is that we take advantage of the particularities of free surface flow, instead of considering it a particular case of two‐phase flow. The fact that a given free surface implies a known boundary condition on the interface, allows us to solve the Navier–Stokes equations on the fluid domain uncoupled from the solution on the rest of the finite element mesh. This, together with the use of enhanced integration allows us to model low Froude number flows accurately, something that is not possible with typical two‐phase flow models applied to free surface flow. Copyright © 2007 John Wiley & Sons, Ltd.
A battery of DNA effect biomarkers to evaluate environmental exposure of Flemish adolescents
Authors: Koppen G. , Verheyen G. , Maes A. , Gorp U. Van , Schoeters G. , Hond E. Den , Staessen J. , Nawrot T. , Roels H. A. , Vlietinck R. , Verschaeve L.
Published: January 2007

The present paper deals with the evaluation of a battery of genotoxicity biomarkers in healthy Flemish adolescents and their relation with common pollutants occurring in their life environment. DNA damage as reflected by the comet assay appeared to be most sensitive to ozone (partial r2 = 0.102, p < 0.00001), and to a lesser extent to ortho‐cresol (partial r2 = 0.055; p = 0.001) and 1‐hydroxy‐pyrene (1‐OH‐pyrene, partial r2 = 0.031; p = 0.013). 8‐hydroxy‐deoxyguanosine (8‐OHdG) was only related to ortho‐cresol (r2 = 0.069; p < 0.007). Interestingly, the comet assay results and urinary 8‐OHdG concentrations were positively correlated with a Pearson r = 0.21 (p = 0.003, N = 200). Logistic regression models revealed significant relations between chromatid breaks and 1‐OH‐pyrene (relative risk (RR): 1.58; p = 0.008), and t,t‐muconic acid (RR: 1.71; p = 0.014). There was no correlation between micronucleus formation or occurrence of chromosomal or chromatid breaks on the one hand and comet or 8‐OHdG results on the other hand. Thus, in this study the comet assay on whole blood samples and urine 8‐OHdG measurements especially appeared sensitive biomarkers for assessing the genetic effects of environmental pollutants to which adolescents may be exposed. Copyright © 2007 John Wiley & Sons, Ltd.
Tumor microenvironment: The role of the tumor stroma in cancer
Authors: Li Hanchen , Fan Xueli , Houghton JeanMarie
Published: January 2007

The tumor microenvironment, composed of non‐cancer cells and their stroma, has become recognized as a major factor influencing the growth of cancer. The microenvironment has been implicated in the regulation of cell growth, determining metastatic potential and possibly determining location of metastatic disease, and impacting the outcome of therapy. While the stromal cells are not malignant per se, their role in supporting cancer growth is so vital to the survival of the tumor that they have become an attractive target for chemotherapeutic agents. In this review, we will discuss the various cellular and molecular components of the stromal environment, their effects on cancer cell dynamics, and the rationale and implications of targeting this environment for control of cancer. Additionally, we will emphasize the role of the bone marrow‐derived cell in providing cells for the stroma. J. Cell. Biochem. 101: 805–815, 2007. © 2007 Wiley‐Liss, Inc.
Dissection of mammalian replicators by a novel plasmid stability assay
Authors: Hashizume Toshihiko , Shimizu Noriaki
Published: January 2007

A plasmid, bearing a mammalian replication initiation region (IR) and a matrix attachment region (MAR) was previously shown to be efficiently amplified to high copy number in mammalian cells and to generate chromosomal homogeneously staining regions (HSRs). The amplification mechanism was suggested to entail a head‐on collision at the MAR between the transcription machinery and the hypothetical replication fork arriving from the IR, leading to double strand breakage (DSB) that triggered HSR formation. The experiments described here show that such plasmids are stabilized if collisions involving not only promoter‐driven transcription but also promoter‐independent transcription are avoided, and stable plasmids appeared to persist as submicroscopic episomes. These findings suggest that the IR sequence that promotes HSR generation may correspond to the sequence that supports replication initiation (replicator). Thus, we developed a “plasmid stability assay” that sensitively detects the activity of HSR generation in a test sequence. The assay was used to dissect two replicator regions, derived from the c‐myc and DHFR ori‐β loci. Consequently, minimum sequences that efficiently promoted HSR generation were identified. They included several sequence elements, most of which coincided with reported replicator elements. These data and this assay will benefit studies of replication initiation and applications that depend on plasmid amplification. J. Cell. Biochem. 101: 552–565, 2007. © 2007 Wiley‐Liss, Inc.
Jedi—a novel transmembrane protein expressed in early hematopoietic cells
Authors: Krivtsov Andrei V. , Rozov Fedor N. , Zinovyeva Marina V. , Hendrikx P. Jan , Jiang Yajuan , Visser Jan W.M. , Belyavsky Alexander V.
Published: January 2007

Self‐renewal and differentiation of hematopoietic stem and progenitor cells are defined by the ensembles of genes expressed by these cells. Here we report identification of a novel gene named Jedi, which is expressed predominantly in short‐ and long‐term repopulating stem cells when compared to more mature bone marrow progenitors. Jedi mRNA encodes a transmembrane protein that contains multiple EGF‐like repeats. Jedi and two earlier reported proteins, MEGF10 and MEGF11, share a substantial homology and are likely to represent a novel protein family. Studies of the potential role of Jedi in hematopoietic regulation demonstrated that the retrovirally mediated expression of Jedi in bone marrow cells decreased the number of myeloid progenitors in in vitro clonogenic assays. In addition, expression of Jedi in NIH 3T3 fibroblasts resulted in a decreased number of late and early myeloid progenitors in the non‐adherent co‐cultured bone marrow cells. Jedi shares a number of structural features with the Jagged/Serrate/Delta family of Notch ligands, and our experiments indicate that the extracellular domain of Jedi, similar to the corresponding domain of Jagged1, inhibits Notch signaling. On the basis of obtained results, we suggest that Jedi is involved in the fine regulation of the early stages of hematopoietic differentiation, presumably through the Notch signaling pathway. J. Cell. Biochem. 101: 767–784, 2007. © 2007 Wiley‐Liss, Inc.
CD36 is a novel and potential anti‐fibrogenic target in albumin‐induced renal proximal tubule fibrosis
Authors: Yang Yu‐Lin , Lin Shyh‐Horng , Chuang Lea‐Yea , Guh Jinn‐Yuh , Liao Tung‐Nan , Lee Tao‐Chen , Chang Wen‐Teng , Chang Fang‐Rong , Hung Min‐Yuan , Chiang Tai‐An , Hung Chien‐Ya
Published: January 2007

Albumin is not only a risk factor for diabetic nephropathy (DN), but also a therapeutic target. Hence, scientists have long sought ways to elucidate the interactions between albumin and diabetic renal tubule fibrosis. CD36, a surface receptor for thrombospondin‐1, has been reported to interact with latent transforming growth factor‐beta1 (TGF‐β1) and activate its fibrogenic bioactivity. This study elucidates the interactions between CD36 and renal tubule fibrosis. LLC‐PK1 cells were applied to represent renal proximal tubule cells. The expression of CD36 was evaluated by flow cytometry. Fibronectin was assayed by Western blot and enzyme‐linked immunosorbent assay (ELISA). Bioactive TGF‐β1 was assayed by ELISA. We demonstrated that albumin was shown significantly to inhibit cell growth without affecting hypertrophy status since protein content and cell size remained unaffected under albumin treatment. Moreover, albumin dose‐dependently (0, 1, or 10 mg/ml) enhanced the secretion of bioactive TGF‐β1 and fibronectin with the upregulation of CD36. Intriguingly, CD36 siRNA, a potent silencer for CD36 effectively suppressed the albumin‐induced increase in CD36, TGF‐β1, and even fibronectin level. Accordingly, albumin is a pro‐fibrogenic factor for proximal tubule cells since albumin per se markedly upregulated the expression of TGF‐β1 and fibronectin. Most importantly, CD36 may mediate albumin‐induced cellular fibrosis since CD36 siRNA appeared to have anti‐fibrosis effects. This work suggests that CD36 is a novel and potential therapeutic target for diabetic renal tubule fibrosis. J. Cell. Biochem. 101: 735–744, 2007. © 2007 Wiley‐Liss, Inc.
Contributions of pro‐oxidant and anti‐oxidant conditions to the actions of 24,25‐dihydroxyvitamin D3 and 1,25‐dihydroxyvitamin D3 on phosphate uptake in intestinal cells
Authors: Peery Sven L. , Nemere Ilka
Published: January 2007

The steroid hormone 1,25‐dihydroxyvitamin D3 [1,25(OH)2D3] rapidly stimulates the uptake of phosphate in isolated chick intestinal cells, while the steroid 24,25‐dihydroxyvitamin D3 [24,25(OH)2D3] inhibits the rapid stimulation by 1,25(OH)2D3. Earlier work in this laboratory has indicated that a cellular binding protein for 24,25(OH)2D3 is the enzyme catalase. Since binding resulted in decreased catalase activity and increased H2O2 production, studies were undertaken to determine if pro‐oxidant conditions mimicked the inhibitory actions of 24,25(OH)2D3, and anti‐oxidant conditions prevented the inhibitory actions of 24,25(OH)2D3. An antibody against the 24,25(OH)2D3 binding protein was found to neutralize the inhibitory effect of the steroid on 1,25(OH)2D3‐mediated 32P uptake. Incubation of cells in the presence of 50 nM catalase was also found to alleviate inhibition. In another series of experiments, isolated intestinal epithelial cells were incubated as controls or with 1,25(OH)2D3, each in the presence of the catalase inhibitor 3‐amino‐1,2,4‐triazole, or with 1,25(OH)2D3 alone. Cells exposed to hormone alone again showed an increased accumulation of 32P, while cells treated with catalase inhibitor and hormone had uptake levels that were indistinguishable from controls. We tested whether inactivation of protein kinase C (PKC), the signaling pathway for 32P uptake, occurred. Incubation of cells with phorbol‐13‐myristate (PMA) increased 32P uptake, while cells pretreated with 50 µM H2O2 prior to PMA did not exhibit increased uptake. Likewise, PMA significantly increased PKC activity while cells exposed to H2O2 prior to PMA did not. It is concluded that catalase has a central role in mediating rapid responses to steroid hormones. J. Cell. Biochem. 101:1176–1184, 2007. © 2007 Wiley‐Liss, Inc.
Phosphorylation of mitochondrial phospholipid scramblase 3 by protein kinase C‐δ induces its activation and facilitates mitochondrial targeting of tBid
Authors: He Yongwen , Liu Jihua , Grossman Douglas , Durrant David , Sweatman Trevor , Lothstein Leonard , Epand Raquel F. , Epand Richard M. , Lee Ray M.
Published: January 2007

Phospholipid scramblase 3 (PLS3) is a member of the phospholipid scramblase family present in mitochondria. PLS3 plays an important role in regulation of mitochondrial morphology, respiratory function, and apoptotic responses. PLS3 is phosphorylated by PKC‐δ at Thr21 and is the mitochondrial target of PKC‐δ‐induced apoptosis. Cells with overexpression of PLS3, but not the phosphoinhibitory mutant PLS3(T21A), are more susceptible to apoptosis induced by AD198, an extranuclear targeted anthracycline that activates PKC‐δ. Here we report that the phosphomimetic mutant of PLS3(T21D) by itself can induce apoptosis in HeLa cells. Using proteoliposomes with addition of pyrene‐labeled phosphatidylcholine (PC) at the outer leaflet, we measured the lipid flip‐flop activity of PLS3 and its phosphorylation mutant. PLS3(T21D) is more potent than wild‐type PLS3 or PLS3(T21A) to transfer pyrene‐PC from the outer leaflet to the inner leaflet of liposomes. Based on our previous finding that PLS3 enhances tBid‐induced mitochondrial damages, we tested the hypothesis that PLS3 enhances cardiolipin translocation to mitochondrial surface and facilitates tBid targeting. Fluorescein‐labeled tBid(G94E) was used as a probe to quantify cardiolipin on the surface of mitochondria. Mitochondria from cells treated with AD198 or cells expressing PLS3(T21D) had a higher level of tBid‐binding capacity than control cells or cells expressing wild‐type PLS3. These findings indicate that phosphorylation of PLS3 by PKC‐δ induces PLS3 activation to facilitate mitochondrial targeting of tBid and apoptosis. J. Cell. Biochem. 101:1210–1221, 2007. © 2007 Wiley‐Liss, Inc.
Oncostatin M promotes osteogenesis and suppresses adipogenic differentiation of human adipose tissue‐derived mesenchymal stem cells
Authors: Song Hae Young , Jeon Eun Su , Kim Jung Il , Jung Jin Sup , Kim Jae Ho
Published: January 2007

Oncostatin M (OSM) is a multifunctional cytokine of the interleukin‐6 family and has been implicated in embryonic development, differentiation, inflammation, and regeneration of liver and bone. In the present study, we demonstrated that treatment of human adipose mesenchymal stem cells (hADSCs) with OSM‐attenuated adipogenic differentiation, as indicated by decreased accumulation of intracellular lipid droplets and down‐regulated expression of adipocytic markers, such as lipoprotein lipase and PPARγ. However, OSM treatment stimulated osteogenic differentiation, as demonstrated by the increase in matrix mineralization and expression levels of osteogenic differentiation markers, including alkaline phosphatase, Runx2, and osteocalcin. OSM treatment induced activation of JAK2, JAK3, and ERK in hADSCs, and pre‐treatment of hADSCs with the JAK2 inhibitor, AG490, significantly restored the OSM‐induced inhibition of adipogenic differentiation. Whereas, the JAK3 inhibitor, WHI‐P131, and the MEK inhibitor, U0126, had no effects on the anti‐adipogenic activity of OSM. On the other hand, the pro‐osteogenic activity of OSM was prevented by treatment of the cells with WHI‐P131 or U0126, but not with AG490. These results indicate that distinct signaling pathways, including JAK2, JAK3, and MEK‐ERK, play specific roles in the OSM‐induced anti‐adipogenic and pro‐osteogenic differentiation of hADSCs. J. Cell. Biochem. 101:1238–1251, 2007. © 2007 Wiley‐Liss, Inc.
Concerted activation of the Mdm2 promoter by p72 RNA helicase and the coactivators p300 and P/CAF
Authors: Shin Sook , Janknecht Ralf
Published: January 2007

A scarcely studied and under‐recognized feature of RNA helicases is their ability to regulate gene transcription. In particular, very little is known about the role of p72 RNA helicase in gene regulation. Here, we have analyzed how this helicase may enhance promoter activity. We demonstrate that p72 RNA helicase forms complexes with the homologous coactivators p300 and CBP in vitro and in vivo, especially leading to an enhancement of the transactivation potential of their C‐termini. In addition, we show that the p300/CBP‐associated protein (P/CAF) also interacts with p72 RNA helicase, and both this interaction and the binding to p300/CBP are mediated by the N‐terminal 63 amino acids of p72 RNA helicase. p300, P/CAF and p72 RNA helicase synergize to stimulate selected promoters, including the Mdm2 one. Notably, downregulation of p72 RNA helicase leads to reduced Mdm2 transcription. Furthermore, our data suggest that p72 RNA helicase activates the Mdm2 promoter in a p53 dependent and independent manner. Collectively, our results have unraveled a mechanism of how p72 RNA helicase can regulate gene transcription, namely by cooperating with p300/CBP and P/CAF. Thereby, p72 RNA helicase may not only be involved in the p53‐Mdm2 regulatory loop, but also profoundly impact on the transcriptome through various CBP/p300 and P/CAF interacting proteins. J. Cell. Biochem. 101:1252–1265, 2007. © 2007 Wiley‐Liss, Inc.
Heparin suppresses lipid raft‐mediated signaling and ligand‐independent EGF receptor activation
Authors: Liu Yuan‐Tao , Song LiFang , Templeton Douglas M.
Published: January 2007

Heparin is well known to suppress vascular smooth muscle cell (VSMC) proliferation, and attempts to exploit this therapeutically have led to recognition of multiple pathways for heparin's anti‐mitogenic actions. At low concentrations (ca. 1 µg · ml−1), these suppressive effects may reflect physiological activities of endogenous heparan sulfates, and appear to be rapid responses to extracellular or cell surface‐associated heparin. Because heparin has been shown to influence expression of caveolin proteins, and caveolae/lipid rafts are critical structures modulating cell signaling, we examined the effect of heparin on signaling involving cholesterol‐rich membrane microdomains. The VSMC line PAC‐1 activates the MAP kinase Erk in response to the cholesterol‐sequestering agents methyl‐β‐cyclodextrin and nystatin. This follows a temporal sequence that involves Ras‐GTP activation of MEK, and is independent of PKC, Src, and PI3 kinase. However, ligand‐independent phosphorylation of the EGF receptor (EGFR) by removal of cholesterol precedes Ras activation, and the EGFR kinase inhibitor AG1478 blocks Erk phosphorylation, supporting occurrence of the signaling sequence EGFR‐Ras‐MEK‐Erk. Phosphorylation of EGFR occurs predominantly in caveolin‐rich microdomains as identified by Western blotting of fractions from density gradient centrifugation of membranes prepared under detergent‐free conditions. In these situations, heparin inhibits phosphorylation of EGFR on the Src‐dependent site Tyr845, but not the autophosphorylation of Tyr1173, and decreases Ras activation and Erk phosphorylation. We conclude that heparin can suppress Erk signaling in VSMC with effects on site‐specific phosphorylation of EGFR localized in caveolin‐enriched lipid rafts. J. Cell. Physiol. 211: 205–212, 2007. © 2007 Wiley‐Liss, Inc.
Dual transcriptional control of claudin‐11 via an overlapping GATA/NF‐Y motif: Positive regulation through the interaction of GATA, NF‐YA, and CREB and negative regulation through the interaction of Smad, HDAC1, and mSin3A
Authors: Lui Wing‐Yee , Wong Elissa W.P. , Guan Yuanfang , Lee Will M.
Published: January 2007

The expression of claudin‐11, a key integral tight junction protein, is tightly regulated to ensure that the integrity of the seminiferous epithelium could be maintained during the translocation of spermatocytes at the blood–testis barrier at stages VIII–IX. In this study, we elucidate how the overlapping GATA/NF‐Y motif within the core promoter of claudin‐11 gene is modulated by differential binding of various transcription factors, resulting in dual transcriptional control. Using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay, we confirmed that GATA, nuclear factor YA (NF‐YA), and cAMP response element‐binding protein (CREB) form a complex in vivo and bind to the GATA/NF‐Y region to promote claudin‐11 gene transcription. Such gene activations were significantly reduced in the presence of siRNA specific to these transcription factors. GATA and CREB transactivation could be further modulated by the presence of Smad3 and Smad4 proteins. Binding of Smad proteins at the GATA/NF‐Y motif could repress the GATA and CREB transactivation of claudin‐11 gene. Such repression which required the recruitment and physical interactions of histone deacetylase 1 and its co‐repressor, mSin3A with Smad proteins, was abolished by treatment with Trichostatin A, thus suggesting the involvement of histone deacetylation at the site of the promoter region. It is believed that cyclic changes in the ratio of positive regulators (GATA, NF‐Y, and CREB) to negative regulators (Smads) in the seminiferous epithelium during the spermatogenic cycle might provide a precise control in claudin‐11 gene transcription. J. Cell. Physiol. 211: 638–648, 2007. © 2007 Wiley‐Liss, Inc.
Evaluation of the viability of cultured corneal endothelial cells by quantitative electron probe X‐ray microanalysis
Authors: Alaminos M. , Sanchez‐Quevedo M.C. , Muñoz‐Ávila J.I. , García J.M. , Crespo P.V. , González‐Andrades M. , Campos A.
Published: January 2007

Construction of artificial organs and tissues by tissue engineering is strongly dependent on the availability of viable cells. For that reason, the viability and the physiological status of cells kept in culture must be evaluated before the cells can be used for clinical purposes. In this work, we determined the viability of isolated rabbit corneal endothelial cells by trypan blue staining and quantitative electron probe X‐ray microanalysis. Our results showed that the ionic content of potassium in cultured corneal endothelial cells tended to rise initially, but significantly decreased in cells in the fifth (and final) subculture, especially in comparison to cells in the fourth subculture (P < 0.001). However, the concentration of sulfur was higher in the fifth subculture than in the fourth subculture (P < 0.001), with a nonsignificant increase in sodium in the fifth subculture (P = 0.031). These data imply a remarkable decrease in the K/Na ratio from the fourth to the fifth subculture. Our microanalytical results, along with the morphological differences between cells in the last two subcultures, are compatible with an early phase of the preapoptotic process in the fifth subculture, and suggest that cells of the first four subcultures would be better candidates for tissue engineering. J. Cell. Physiol. 211: 692–698, 2007. © 2007 Wiley‐Liss, Inc.
The small‐scale manufacturing sector in Ghana: a source of dynamism or of subsistence income?
Authors: Mensah John Victor , Tribe Michael , Weiss John
Published: January 2007

Survey data from small‐scale manufacturing enterprises in Central Region, Ghana permit analysis of factors affecting performance, and of economic dynamism. The majority of the firms were sole proprietorships, with most of the hired labour being apprentices. A high proportion of rural‐based proprietors and many urban‐based proprietors had secondary occupations. All but two of the industry groups were unprofitable when the legal minimum wage was used as a proxy for the value of proprietors' time. The implication of this is that the small‐scale industries are principally a source of modest income and may not be financially and economically dynamic. However, the small enterprises surveyed do seem to represent part of a ‘sustainable livelihoods’ strategy of lowering economic risk by diversifying income sources. Copyright © 2007 John Wiley & Sons, Ltd.
Designer Self‐Assembling Peptide Materials
Authors: Zhao Xiaojun , Zhang Shuguang
Published: January 2007

Understanding of macromolecular materials at the molecular level is becoming increasingly important for a new generation of nanomaterials for nanobiotechnology and other disciplines, namely, the design, synthesis, and fabrication of nanodevices at the molecular scale from bottom up. Basic engineering principles for microfabrication can be learned through fully grasping the molecular self‐assembly and programmed assembly phenomena. Self‐ and programmed‐assembly phenomena are ubiquitous in nature. Two key elements in molecular macrobiological material productions are chemical complementarity and structural compatibility, both of which require weak and non‐covalent interactions that bring building blocks together during self‐assembly. Significant advances have been made during the 1990s at the interface of materials chemistry and biology. They include the design of helical ribbons, peptide nanofiber scaffolds for three‐dimensional cell cultures and tissue engineering, peptide surfactants for solubilizing and stabilizing diverse types of membrane proteins and their complexes, and molecular ink peptides for arbitrary printing and coating surfaces as well as coiled‐coil helical peptides for multi‐length scale fractal structures. These designer self‐assembling peptides have far reaching implications in a broad spectrum of applications in biology, medicine, nanobiotechnology, and nanobiomedical technology, some of which are beyond our current imaginations.

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Water‐Triggered Frontal Polymerization
Authors: Pujari Narahari S. , Inamdar Satish R. , Ponrathnam Surendra , Kulkarni Bhaskar D.
Published: January 2007

A totally new mode of frontal polymerization (FP) of acrylamide is established which is triggered by the simple addition of a minute, specific volume of water. Experimental conditions under which this mode of polymerization yields linear and water‐soluble polyacrylamide were carefully established, paving the way to synthesize commercially pertinent homo‐ and copolymers. A new redox couple was identified to circumvent the imidization and the ensuing gelation, hitherto associated with FP of acrylamide. Effects of reaction variables such as type and concentration of redox couple and volume of water on measurable parameters of FP such as front velocity, front temperature, shape of front and yield have been studied. Two types of redox couples are reported. Nonplanar frontal regime was observed in few redox couples. We could visually observe helical patterns with naked eyes, while layered patterns were observable under SEM. Additionally, micro‐phase separation and heterogeneity in the polymer matrix was observed due to unreacted pockets of monomer which evolve via bulk mode. This nonlinear phenomenon is described.

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