bluuebunny/crossref_metadata_2025 huggingface dataset:
Retinal ganglion cell protection by 17‐β‐estradiol in a mouse model of inherited glaucoma
Authors: Zhou Xiaohong , Li Feng , Ge Jian , Sarkisian Steven R. , Tomita Hiroshi , Zaharia Alexander , Chodosh James , Cao Wei
Published: February 2007

Glaucoma is the second leading cause of blindness in the world. The ultimate cause of vision loss due to glaucoma is thought to be retinal ganglion cell (RGC) apoptosis. Neuroprotection of RGC is becoming an important approach of glaucoma therapy. Several lines of evidence suggest that estrogen has neurotrophic and neuroprotective properties. In this study, we examine the role of estrogen in preventing RGC loss in DBA/2J mouse, an in vivo model of an inherited (pigmentary) glaucoma. Two‐month‐old female DBA/2J mice were anesthetized and ovariectomized with or without subcutaneous 17β‐estradiol (βE2) pellet implantation. RGC survival was evaluated from flat‐mounted whole retinas by counting retrograde‐labeled cells. The loss of nerve fibers and RGC were also evaluated in paraffin‐fixed retinal cross sections. Biochemical alterations in the retinas of DBA/2J mice in response to systemic injection of βE2 were also examined. We have made several important observations showing that: (1) βE2 treatment reduced the loss of RGC and neurofibers through inhibition of ganglion cell apoptosis, (2) βE2 activated Akt and cAMP‐responsive‐element‐binding‐protein (CREB), (3) βE2 up‐regulated thioredoxin‐1 (Trx‐1) expression, (4) βE2 reduced the increased activations of mitogen‐activated protein kinases (MAPK) and NF‐κB, (5) βE2 inhibited the increased interleukin‐18 (IL‐18) expression, and (6) treatment with tamoxifen, an estrogen receptor antagonist, blocked βE2‐mediated activation of Akt and inhibition of MAPK phosphorylation in the retinas of DBA/2J mice. These findings suggest the possible involvement of multiple biochemical events, including estrogen receptor/Akt/CREB/thioredoxin‐1, and estrogen receptor/MAPK/NF‐κB, in estrogen‐mediated retinal ganglion cell protection. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Effect of incubation temperature and androgens on dopaminergic activity in the leopard gecko, Eublepharis macularius
Authors: Dias Brian George , Ataya Ramona Sousan , Rushworth David , Zhao Jun , Crews David
Published: February 2007

Male leopard geckos that hatch from eggs incubated at a female‐biased temperature (Tf) behave differently when compared with males hatching at a temperature which produces a male‐biased sex ratio (Tm). We investigated the effect of incubation temperature and androgen implantation on aspects of the dopaminergic system of Tf and Tm males. Our data suggest that more dopamine (DA) is stored in the nucleus accumbens of naive Tf males compared with naïve Tm males when they encounter a receptive female conspecific across a barrier. No difference was measured in the preoptic area and the ventral tegmental area (VTA). This difference in intracellular DA levels in a motivation‐related brain nucleus might be correlated with differences in sociosexual behavior observed between the two morphs. There were no differences in tyrosine hydroxylase (TH) expressing cell numbers in the VTA of cholesterol (CH)‐implanted naive castrated Tf and Tm males. Only Tf males implanted with testosterone had significantly higher TH immunopositive cell numbers in the VTA compared with CH‐ and dihydrotestosterone‐implanted Tf males. These data indicate that both the embryonic environment as well as the circulating hormonal milieu can modulate neurochemistry, which might in turn be a basis for individual variation in behavior. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Regeneration in zebrafish lateral line neuromasts: Expression of the neural progenitor cell marker sox2 and proliferation‐dependent and‐independent mechanisms of hair cell renewal
Authors: Hernández Pedro P. , Olivari Francisco A. , Sarrazin Andrés F. , Sandoval Pablo C. , Allende Miguel L.
Published: February 2007

Mechanosensory hair cells are essential for audition in vertebrates, and in many species, have the capacity for regeneration when damaged. Regeneration is robust in the fish lateral line system as new hair cells can reappear after damage induced by waterborne aminoglycoside antibiotics, platinum‐based drugs, and heavy metals. Here, we characterize the loss and reappearance of lateral line hair cells induced in zebrafish larvae treated with copper sulfate using diverse molecular markers. Transgenic fish that express green fluorescent protein in different cell types in the lateral line system have allowed us to follow the regeneration of hair cells after different damage protocols. We show that conditions that damage only differentiated hair cells lead to reappearance of new hair cells within 24 h from nondividing precursors, whereas harsher conditions are followed by a longer recovery period that is accompanied by extensive cell division. In order to characterize the cell population that gives rise to new hair cells, we describe the expression of a neural stem cell marker in neuromasts. The zebrafish sox2 gene is strongly expressed in neuromast progenitor cells, including those of the migrating lateral line primordium, the accessory cells that underlie the hair cells in neuromasts, and in interneuromastic cells that give rise to new neuromasts. Moreover, we find that most of the cells that proliferate within the neuromast during regeneration express this marker. Thus, our results describe the dynamics of hair cell regeneration in zebrafish and suggest the existence of at least two mechanisms for recovery of these cells in neuromasts. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Costimulation induced phosphorylation of L‐plastin facilitates surface transport of the T cell activation molecules CD69 and CD25
Authors: Wabnitz Guido H. , Köcher Thomas , Lohneis Philipp , Stober Christoph , Konstandin Mathias H. , Funk Beate , Sester Urban , Wilm Matthias , Klemke Martin , Samstag Yvonne
Published: February 2007

Rearrangements in the actin cytoskeleton play a pivotal role for costimulation‐induced formation of the immunological synapse and T cell activation. Yet, little is known about the actin‐binding proteins that link costimulation to rearrangements in the actin cytoskeleton. Here we demonstrate that phosphorylation of the actin bundling protein L‐plastin in response to costimulation through TCR/CD3 plus CD2 or CD28, respectively, is important for the activation of human peripheral blood T lymphocytes (PBT). Mass spectrometry and site‐directed mutagenesis revealed that Ser5 represents the only phospho‐acceptor site of L‐plastin in PBT. Wild‐type L‐plastin (wt‐LPL) and a non‐phosphorylatable 5A‐L‐plastin (5A‐LPL) equally relocalized to the immunological synapse between PBT and APC. Yet importantly, cells expressing 5A‐LPL showed a significantly lower expression of the T cell activation molecules CD25 and CD69 on the cell surface than cells expressing wt‐LPL. This effect is due to a failure in the transport of CD25 and CD69 to the cell surface since the total amount of these proteins within the cells remained unchanged. In conclusion, phosphorylation of the actin bundling protein L‐plastin represents a so‐far‐unknown mechanism by which costimulation controls the transport of activation receptors to the T cell surface.
Facile Synthesis of Oligothiophene‐Capped CdS Nanoparticles
Authors: Antoun Tarek , Brayner Roberta , Al terary Seham , Fiévet Fernand , Chehimi Mohamed , Yassar Abderrahim
Published: February 2007

CdS nanoparticles functionalized by electroactive oligothiophenes, with narrow size distribution, have been prepared and characterized. The structure of the hybrid product was investigated by TEM, XRD, optical and FTIR spectroscopy. The modified nanoparticles consist of a few tens of oligothiophene units attached to the CdS core. The grafting of conjugated oligomers to nanoparticles was made possible by complexing the dangling cadmium ion on the nanoparticle surface.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Neutral Yttrium Tris(amide) and Ate Complexes Coordinated by an (R)‐N,N′‐Diisopropyl‐1,1′‐binaphthyl‐2,2′‐diamido Ligand as Enantioselective Catalysts for Intramolecular Hydroamination
Authors: Riegert David , Collin Jacqueline , Daran Jean‐Claude , Fillebeen Tauqir , Schulz Emmanuelle , Lyubov Dmitrii , Fukin Georgy , Trifonov Alexander
Published: February 2007

A bis(amido)yttrium chloride coordinated by (R)‐N,N′‐diisopropyl‐1,1′‐binaphthyl‐2,2′‐diamide [Y{(R)‐C20H12(NiPr)2}Cl(thf)2] has been prepared and characterized by X‐ray analysis along with the corresponding yttrium ate complex [Li(thf)4][Y{(R)‐C20H12(NiPr)2}2]. The reaction of [(R)‐N,N′‐diisopropyl‐1,1′‐binaphthyl‐2,2′‐diamido]yttrium chloride with lithium diisopropylamine leads to the formation of a neutral tris(amido)yttrium complex which was characterized by NMR spectroscopy. The new complexes [Y{(R)‐C20H12(NiPr)2}{NiPr2}] and [{Li(thf)4}(Y{(R)‐C20H12(NiPr)2}2)], which contain the same enantiopure binaphthyldiamido ligand, are compared for the catalysis of several intramolecular hydroamination reactions. Both complexes provide pyrrolidines andpiperidines with moderate to high enantioselectivities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Spin‐Center Shift (SCS) – A Versatile Concept in Biological and Synthetic Chemistry
Authors: Wessig Pablo , Muehling Olaf
Published: February 2007

Reactions involving radical intermediates are nowadays an inherent part of organic chemistry and the impressive progress in this area in recent decades has contributed to the understanding of many biological processes and provided many valuable methods for preparative chemists. By analyzing the mechanism of some biochemical transformations involving radical intermediates a common principle emerges. If at the atom adjacent to an α‐hydroxy or α‐alkoxy radical a leaving group is tethered a rapid elimination takes place and the spin density is shifted by one atom. This concept, called the spin‐center shift (SCS), considerably extends the scope of some radical reactions. This microreview provides an overview of both biochemical examples of the SCS concept and synthetic applications. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Efficient Synthesis of 2‐Methyl Derivatives of 1,1′‐Bi(2‐naphthol) and 1,1′‐Bi(2‐phenols)
Authors: Solinas Maurizio , Meadows Rebecca E. , Wilson Claire , Blake Alexander J. , Woodward Simon
Published: February 2007

Reaction of 1,1′‐binaphthol and structurally related 1,1′‐biphenols with sulfonylating reagents [RSO2Cl; R = 4‐Tol, Ph] leads to clean, ultraselective monoderivatisation, shown crystallographically in one case (2‐OH–2′‐OTs–1,1′‐binaphthyl). Reaction of the remaining 2‐hydroxy function with either Tf2O or NfF [Nf = nonaflate, CF3(CF2)3SO2‐] affords the protected/activated cores (2‐R1O–2′‐R2O–1,1′‐biaryl) [R1,R2 pairs = Tf,Ts (X‐ray); Tf,SO2Ph; Nf,Ts (on 1,1′‐binaphthyl core); Tf,Ts; Nf,Ts (on 1,1′‐biphenyl core); Tf,Ts; Nf,Ts (on 3,3′,5,5′‐tetramethyl‐1,1′‐biphenyl core)]. Reaction of the Tf,Ts species with either MeMgBr/NiCl2(dppe) (for the 1,1′‐binaphthyl) or (AlMe3)2(DABCO)/Pd2(dba)3 (for the 1,1′‐biphenyl) affords 2‐OH–2′‐Me–1,1′‐biaryl units on subsequent hydrolysis (crystallographically characterised in the binaphthyl case). The latter methyl/hydroxy compounds are doubly deprotonated by either nBuLi/TMEDA or nBuLi/tBuOK to afford dianions that react cleanly with Cl2SiPh2 (two X‐ray structures). The equivalent reaction of the 2‐OH–2′‐Me–1,1′‐binaphthyl with Ph(O)Cl2 is less clean due to the absence of a strong Thorpe–Ingold effect. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Ring–Chain Tautomerism of Simplified Analogues of Isoniazid–NAD(P) Adducts: an Experimental and Theoretical Study
Authors: Delaine Tamara , Bernardes‐Génisson Vania , Stigliani Jean‐Luc , Gornitzka Heinz , Meunier Bernard , Bernadou Jean
Published: February 2007

Simplified analogues of oxidized and reduced isoniazid–NAD(P) adducts were prepared to study their behaviour with regard to ring–chain tautomeric isomerism in solution. In DMSO, the oxidized analogues (pyridinium salts) and the corresponding 1,2‐dihydropyridine‐reduced compounds were found to exist exclusively in the ring (cyclic hemiamidal) form. In contrast, the 1,4‐dihydropyridine‐reduced analogues were present in the ring and/or chain forms depending on the nature of the aromatic substituent. The 1,4‐dihydropyridines (Ar = Ph, 3Cl‐Py) are, in solution, preferentially in the keto–amide chain form, whereas the pyridine analogue (Ar = Py), which is the closest model of the isoniazid–NAD(P) adduct, exists as ring (major) and chain (minor) tautomers in equilibrium. The ratio of the tautomeric forms involved in the equilibrium of this system is also influenced by the polarity of the solvent with a shift towards the ring tautomer when the polarity of the solvent is increased. Complementary computational studies were performed by using quantum chemical calculations (B3LYP/6‐31G**) and frontier molecular orbital analysis, which allowed the key structural factors involved in the ring–chain tautomerism equilibrium to be discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A Novel Route to a Bromo‐Cyano‐Substituted Azulene and Its Exploitation in the Construction of an Acetylenic Scaffold
Authors: Petersen Michael Åxman , Kilså Kristine , Kadziola Anders , Nielsen Mogens Brøndsted
Published: February 2007

A novel route to functionalized azulenes is devised from a dihydroazulene precursor. Thus, bromination of 1,1‐dicyano‐2‐phenyl‐1,8a‐dihydroazulene followed by heating in the presence of bromide ions provides an efficient way to generate 3‐bromo‐1‐cyano‐2‐phenylazulene. Formation of this somewhat unexpected product was confirmed by X‐ray crystallographic analysis. It undergoes a palladium‐catalyzed cross‐coupling reaction with trimethylsilylacetylene, affording a new azulene building block for acetylenic scaffolding. Oxidative homo‐coupling hereof provides an azulene dimer, for which the optical and electrochemical properties are compared to the other azulenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Retributive justice and social categorizations: the perceived fairness of punishment depends on intergroup status
Authors: van Prooijen Jan‐Willem , Lam Jerôme
Published: February 2007

In the current research, the authors investigate the influence of intergroup status and social categorizations on retributive justice judgments, that is, the extent to which observers perceive punishment as fair. Building on social identity theory and the model of subjective group dynamics, it is predicted that when the ingroup has higher status than the outgroup, people are relatively less concerned about punishment of an outgroup offender than when the ingroup has lower status than the outgroup. Two experiments revealed that participants are more punitive towards an ingroup than an outgroup offender when ingroup status is high but not when ingroup status is low. Furthermore, in correspondence with our line of reasoning, this finding emerged because participants were less punitive towards outgroup offenders when ingroup status is high than when ingroup status was low. It is concluded that the perceived fairness of punishment depends on the offender's social categorization and intergroup status. Copyright © 2007 John Wiley & Sons, Ltd.
Familiar eyes are smiling: on the role of familiarity in the perception of facial affect
Authors: Claypool Heather M. , Hugenberg Kurt , Housley Meghan K. , Mackie Diane M.
Published: February 2007

Quickly and accurately perceiving others' facial affect is paramount for successful social interaction. This work investigates the role of familiarity in helping us to interpret others' facial emotions. In Experiments 1 and 2, participants viewed several faces, some familiar and some novel, and judged how happy each face appeared. As predicted, results showed that familiar faces were perceived as happier than were novel faces. In Experiment 3, participants again viewed several faces, some familiar and some not, and rated the perceived anger or happiness of these faces. As expected, familiar faces were perceived as happier and less angry than were novel faces. Thus, these results suggest that familiarity is one cue we use to interpret the facial affect of others. Copyright © 2007 John Wiley & Sons, Ltd.
Solid‐State Reference Electrode Based on Electrodeposited Nanoporous Platinum for Microchip
Authors: Han Ji‐Hyung , Park Sejin , Boo Hankil , Kim Hee Chan , Nho Jongmin , Chung Taek Dong
Published: February 2007

A new solid‐state reference electrode operating in buffered aqueous solution for electrochemical system on microfluidic chip is reported. The anodized nanoporous platinum showed its usefulness as a solid‐state reference electrode owing to near‐Nernstian behavior, low hysteresis, and quick response. The presence of redox couples such as Fe(CN)$\rm{ _6^{3 - /4 - } }$, bringing about significant interference, can be successfully suppressed by an electropolymerized poly‐1,3‐phenylendiamine (poly‐m‐PD) layer on the nanoporous platinum surface. Since the poly‐m‐PD coated nanoporous platinum oxide responds exclusively to pH, its potential should be constant and stable in a buffer solution. The nanoporous platinum oxide with poly‐m‐PD film is easy to produce and is particularly compatible with microfabrication. The experimental results in this study demonstrate that the proposed system successfully works as a solid‐state reference electrode that should be integrated on microchips for microanalysis systems.
Improvement of Selectivity and Stability of Amperometric Detection of Hydrogen Peroxide Using Prussian Blue‐PAMAM Supramolecular Complex Membrane as a Catalytic Layer
Authors: Wu Shouguo , Wang Taoling , Wang Changqin , Gao Zongyong , Wang Chuanqin
Published: February 2007

A novel hydrogen peroxide (H2O2) sensor was fabricated by using a submonolayer of 3‐mercaptopropionic acid (3‐MPA) adsorbed on a polycrystalline gold electrode further reacted with poly(amidoamine) (PAMAM) dendrimer (generation 4.0) to obtain a film on which Prussian Blue (PB) was later coordinated to afford a mixed and stable electrocatalytic layer for H2O2 reduction. On the basis of the electrochemical behaviors, atomic force microscopy (AFM) and X‐ray photoelectron spectra (XPS), it is suggested that the PB molecules are located within the dendritic structure of the surface attached PAMAM dendrimers. It was found that the PB/PAMAM/3‐MPA/Au modified electrode showed an excellent electrocatalytic activity for H2O2 reduction. The effects of applied potential and pH of solution upon the response of the modified electrode were investigated for an optimum analytical performance. Even in the presence of dissolved oxygen, the sensor exhibited highly sensitive and rapid response to H2O2. The steady‐state cathodic current responses of the modified electrode obtained at −0.20 V (vs. SCE) in air‐saturated 0.1 mol L−1 phosphate buffer solution (PBS, pH 6.50) showed a linear relationship to H2O2 concentration ranging from 1.2×10−6 mol L−1 to 6.5×10−4 mol L−1 with a detection limit of 3.1×10−7 mol L−1. Performance of the electrode was evaluated with respected to possible interferences such as ascorbic acid and uric acid etc. The selectivity, stability, and reproducibility of the modified electrode were satisfactory.
Irreversible and Reversible Deactivation of Bilirubin Oxidase by Urate
Authors: Shin Hyosul , Kang Chan , Heller Adam
Published: February 2007

Oxygen is electroreduced to water on a carbon cathode coated with wired bilirubin oxidase in a pH 7.4 0.15 M NaCl phosphate buffer solution at 37 °C at much lesser polarization than it is on a pure platinum cathode in 0.5 M H2SO4. While the wired bilirubin oxidase cathode operates for over a week in the aerated or oxygenated buffer solution, it is degraded rapidly when in serum. We reported earlier that in the presence of O2 an intermediate product of the electrooxidation of urate, which is a normal serum component, irreversibly damages the wired bilirubin oxidase and also reported that the electrocatalyst is irreversibly damaged, in the absence of urate, when it is brought, by disconnecting the electrode, to the O2/H2O half cell potential at pH 7.4. Here we report that a) dissolved bilirubin oxidase is irreversibly and rapidly damaged by urate in the presence of O2; and b) that the immobilized wired bilirubin oxidase electrocatalyst is not only irreversibly deactivated by urate in the presence of O2 in a few hours, but is initially reversibly deactivated, in 1 min or less, by the urate in the presence of O2.
Xanthine Sensors Based on Anodic and Cathodic Detection of Enzymatically Generated Hydrogen Peroxide
Authors: Rahman Md. Aminur , Won Mi‐Sook , Shim Yoon‐Bo
Published: February 2007

A xanthine biosensor was fabricated by the covalent immobilization of xanthine oxidase (XO) onto a functionalized conducting polymer (Poly‐5, 2′: 5′, 2″‐terthiophine‐3‐carboxylic acid), poly‐TTCA through the formation of amide bond between carboxylic acid groups of poly‐TTCA and amine groups of enzyme. The immobilization of XO onto the conducting polymer (XO/poly‐TTCA) was characterized using cyclic voltammetry, quartz crystal microbalance (QCM), and X‐ray photoelectron spectroscopy (XPS) techniques. The direct electron transfer of the immobilized XO at poly‐TTCA was found to be quasireversible and the electron transfer rate constant was determined to be 0.73 s−1. The biosensor efficiently detected xanthine through oxidation at +0.35 V and reduction at −0.25 V (versus Ag/AgCl) of enzymatically generated hydrogen peroxide. Various experimental parameters, such as pH, temperature, and applied potential were optimized. The linear dynamic ranges of anodic and cathodic detections of xanthine were between 5.0×10−6−1.0×10−4 M and 5.0×10−7 to 1.0×10−4 M, respectively. The detection limits were determined to be of 1.0×10−6 M and 9.0×10−8 M with anodic and cathodic processes, respectively. The applicability of the biosensor was tested by detecting xanthine in blood serum and urine real samples.
Sensitive Biosensors Based on (Dendrimer Encapsulated Pt Nanoparticles)/Enzyme Multilayers
Authors: Zhu Yihua , Zhu Huiyu , Yang Xiaoling , Xu Lihuan , Li Chunzhong
Published: February 2007

A sensitive enzymed‐based biosensor for glucose has been obtained by introducing dendrimer encapsulated Pt nanoparticles via a layer‐by‐layer assembling method. The free amine groups located on each poly(amidoamine) dendrimer molecule were exploited to covalently attach enzyme to the dendrimer chains using carbodiimide coupling. The resultant enzyme electrodes are shown to have excellent sensitivity (as high as 30.33 μA mM−1 cm−2) and a limit of detection (about 0.1 μmol L−1), depending on metal nanoparticles within dendrimers and the biocompatibility of dendrimers, the linear response range to glucose (from 5 μM to 1.0 mM), a fast response time (within 5 s), and good reproducibility (<8% relative standard deviation between electrodes at low substrate concentration). The sensitivities, and stabilities determined experimentally have demonstrated the potential of dendrimer encapsulated Pt nanoparticles as a novel candidate for enzymatic glucose biosensors.
Unified models for adaptive OFDM systems when QAM or PSK modulation is applied
Authors: Assimakopoulos Costas , Pavlidou F.‐N.
Published: February 2007

In this paper, the solutions of the major bit‐loading problems that are found in the literature, are unified into simple equations (models). These equations give an insight of the affection of the channel over a multicarrier system. Moreover, the models allow the transition from the solution of one loading problem to the solution of the others. The models are dependent on the modulation type that is used. We examine the quadrature amplitude modulation (QAM) modulated orthogonal frequency division multiplexing (OFDM), and the phase shift keying (PSK)‐modulated OFDM systems. For each modulation type, the continuous throughput model is extracted. The continuous throughput model refers to a system that its subcarriers can be loaded with non‐integer number of bits. The non‐integer bit distribution can then be rounded to integers, using a rounding method. The models except from the calculation of the optimised quantities (total data rate, total power and symbol error rate) without the need of running a loading algorithm to its extent, provide a means to manipulate a whole multicarrier system in a way similar to single‐carrier system. Copyright © 2007 John Wiley & Sons, Ltd.
Performance enhancement of perfect difference codes with spectral amplitude coding using sub‐optimal decision threshold
Authors: Jhou Jhih‐Syue , Lin Jen‐Yung , Wen Jyh‐Horng
Published: February 2007

This paper applies perfect difference code (PDC) to develop an optical code‐division multiple‐access (OCDMA) system with spectral amplitude coding (SAC). The differential receiver of the proposed systems exploits the cross‐correlation property of PDC to remove the multiple‐access interference (MAI) without reducing the power of the received signal. The threshold applied in the data decision process has a crucial influence on the bit error rate (BER). Hence, this study investigates the effects of several different decision rules. The numerical results show that the BERs of the synchronous OCDMA system using PDC proposed by Weng and Wu are 100 times and 17 times greater than those of the current system for code sizes of 183 and 307, respectively, under conditions of equal power budgets. To achieve the same BERs, the theoretical analysis reveals that the transmission power required by the Weng's system is around k/(k‐1) times greater than that of the current system, where k denotes the code weight of the signature code employed. Additionally, under conditions of reliable communication (i.e. BER ≤ 10−9), the capacity of the proposed system is almost one and half times greater than that of Weng's system. Regarding the data decision threshold, this study proposes a realisable sub‐optimal decision threshold as a replacement for the optimal decision threshold. The performance of the proposed system using this sub‐optimal threshold is found to be only marginally poorer than that obtained when the optimal decision threshold is employed. Therefore, the proposed sub‐optimal threshold provides a suitable means of improving the system performance of SAC OCDMA systems using signature codes with a fixed in‐phase cross‐correlation property. Copyright © 2007 John Wiley & Sons, Ltd.
The use of monthly indicators to forecast quarterly GDP in the short run: an application to the G7 countries
Authors: Golinelli Roberto , Parigi Giuseppe
Published: February 2007

The delayed release of the National Account data for GDP is an impediment to the early understanding of the economic situation. In the short run, this information gap may be at least partially eliminated by bridge models (BM) which exploit the information content of timely updated monthly indicators. In this paper we examine the forecasting ability of BM for GDP growth in the G7 countries and compare their performance to that of univariate and multivariate statistical benchmark models. We run four alternative one‐quarter‐ahead forecasting experiments to assess BM performance in situations as close as possible to the actual forecasting activity. BM are estimated for GDP both for single countries (USA, Japan, Germany, France, UK, Italy and Canada), and area‐wide (G7, European Union, and Euro area). BM forecasting ability is always superior to that of benchmark models, provided that at least some monthly indicator data are available over the forecasting horizon.  Copyright © 2007 John Wiley & Sons, Ltd.
Using a heterogeneous multinomial probit model with a neural net extension to model brand choice
Authors: Hruschka Harald
Published: February 2007

The multinomial probit model introduced here combines heterogeneity across households with flexibility of the (deterministic) utility function. To achieve flexibility deterministic utility is approximated by a neural net of the multilayer perceptron type. A Markov Chain Monte Carlo method serves to estimate heterogeneous multinomial probit models which fulfill economic restrictions on signs of (marginal) effects of predictors (e.g., negative for price). For empirical choice data the heterogeneous multinomial probit model extended by a multilayer perceptron clearly outperforms all the other models studied. Moreover, replacing homogeneous by heterogeneous reference price mechanisms and thus allowing price expectations to be formed differently across households also leads to better model performance. Mean utility differences and mean elasticities w.r.t. price and price deviation from reference price demonstrate that models with linear utility and nonlinear utility approximated by a multilayer perceptron lead to very different implications for managerial decision making.  Copyright © 2007 John Wiley & Sons, Ltd.
Implementing student information systems
Authors: Sullivan Laurie , Porter Rebecca
Published: February 2007

Implementing an enterprise resource planning system is a complex undertaking. Careful planning, management, communication, and staffing can make the difference between a successful and unsuccessful implementation.
Implementation never ends! the postimplementation organizational and operational implications of ERP
Authors: Goldstein Philip J.
Published: February 2007

Planning for the ongoing support and maintenance that accompany implementation of new enterprise resource planning systems may be more essential to realizing benefit from a technology investment than choosing the product with the most features.
The impact of implementing new information systems on the priorities, management, and allocation of resources at colleges and universities
Authors: Hossler Don
Published: February 2007

The hidden dimensions of leadership and of the costs associated with the implementation of new information systems should be carefully considered. They can help determine the short‐ and long‐term success of new systems.
Reactivation with a simple exposure to the experimental environment is sufficient to induce reconsolidation requiring protein synthesis in the hippocampal CA3 region in mice
Authors: Artinian Julien , Jaeger Xavier De , Fellini Laetitia , Saint Blanquat Paul de , Roullet Pascal
Published: February 2007

Our understanding of the memory reconsolidation process is at an earlier stage than that of consolidation. For example, it is unclear if, as for memory consolidation, reconsolidation of a memory trace necessitates protein synthesis. In fact, conflicting results appear in the literature and this discrepancy may be due to differences in the experimental reactivation procedure. Here, we addressed the question of whether protein synthesis in the CA3 hippocampal region is crucial in memory consolidation and reconsolidation of allocentric knowledge after reactivation in different experimental conditions in the Morris water maze. We showed (1) that an injection of the protein synthesis inhibitor anisomycin in the CA3 region during consolidation or after a single reactivation trial disrupted performance and (2) that protein synthesis is required even after a simple contextual reactivation without any learning trial and independently of the presence of the reinforcement. This work demonstrates that a simple exposure to the spatial environment is sufficient to reactivate the memory trace, to make it labile, and that reconsolidation of this trace requires de novo protein synthesis. © 2007 Wiley‐Liss, Inc.
Reactivation of behavioral activity during sharp waves: A computational model for two stage hippocampal dynamics
Authors: Molter Colin , Sato Naoyuki , Yamaguchi Yoko
Published: February 2007

The rodent hippocampus is known to exhibit two very distinctive patterns of activity: theta with place selective cells firing during exploratory behavior and sharp waves (SPWs) associated with collective discharges in the CA3 during slow wave sleep (SWS), inactivity while awake and consummatory behavior. A great deal of evidence has demonstrated that the cells activated during SPWs events are representative of previous behavioral activity, which suggests an important functional role of off‐line learning and consolidation for these SPWs events. Supporting this view, forward, and more recently, reverse replay of linear track behavioral sequences have been reported in rodent's hippocampal place cells during SPWs. We demonstrate here that these patterns of reactivation can be successfully reproduced by relying on a computational model of the hippocampus with theta phase precession and synaptic plasticity during theta rhythm. Two mechanisms are proposed to initiate SPWs events: random reactivation in the presence of rapid, irregular subthreshold inputs and place selective cell activations. In 2D navigation computational experiments, rather than observing the perfect replay of experienced pathways, new pathways “experienced during immobility” emerge. This suggests a neural mechanism for shortcut navigation. © 2007 Wiley‐Liss, Inc.
Mucin‐depleted foci are modulated by dietary treatments and show deregulation of proliferative activity in carcinogen‐treated rodents
Authors: Femia Angelo Pietro , Caderni Giovanna , Bottini Consuelo , Salvadori Maddalena , Dolara Piero , Tessitore Luciana
Published: February 2007

The correlation between mucin‐depleted foci (MDF) and colon carcinogenesis was studied in F344 rats initiated with 1,2‐dimethylhydrazine and treated with a chemopreventive regimen (polyethylene glycol, PEG) or with a promoting diet (high‐corn oil). High corn oil diet increased MDF, while PEG reduced them. The expression of p27 and p16, inhibitors of cyclin‐dependent kinases, which inhibit the progression of the cell cycle, was studied by immunohistochemistry in MDF and in aberrant crypt foci (ACF) of control rats. In both MDF and ACF, the nuclear expression of p27 was markedly reduced, while p16 was reduced to a lower extent. Mitotic activity was higher in MDF and ACF than in normal mucosa of control rats. MDF were also identified in azoxymethane‐initiated SWR/J mice. These results further confirm that MDF are preneoplastic lesions and could be useful biomarkers of colon carcinogenesis. © 2007 Wiley‐Liss, Inc.
Expression of neutral endopeptidase (NEP/CD10) on pancreatic tumor cell lines, pancreatitis and pancreatic tumor tissues
Authors: Erhuma Mabruk , Köbel Martin , Mustafa Tarek , Wulfänger Jens , Dralle Henning , Hoang‐Vu Cuong , Langner Jürgen , Seliger Barbara , Kehlen Astrid
Published: February 2007

Neutral endopeptidase (NEP/CD10) is a cell surface zinc metalloprotease cleaving peptide bounds on the amino terminus of hydrophobic amino acids and inactivating multiple physiologically active peptides. Loss or decrease in NEP/CD10 expression have been reported in many types of malignancies, but the role of NEP/CD10 in pancreatic carcinoma has not yet been identified. Using real‐time RT‐PCR, flow cytometry as well as immunohistochemistry, NEP/CD10 expression was quantified in both pancreatic carcinoma cell lines and in tumor specimens obtained from patients with primary pancreatic carcinomas. Three out of 8 pancreatic carcinoma cell lines exhibit heterogeneous NEP/CD10 expression levels: PATU‐8988T expressed the highest NEP/CD10 levels, whereas HUP‐T4 and HUP‐T3 cells showed a moderate to low NEP/CD10 expression. NEP/CD10 immunoreactivity was found in 6 of 24 pancreatic ductal adenocarcinomas, but also in 3 of 6 tissues of patients with chronic pancreatitis. NEP/CD10 expression in pancreatic tumor lesions and cell lines was not associated with tumor grading and staging. Treatment of PATU‐8988T cells with the histone deacetylase inhibitors sodium butyrate and valproic acid induced an increase of NEP/CD10 expression. This was accompanied by a reduced cell proliferation rate of PATU‐8988T cells, which was increased by the addition of the enzyme activity inhibitors phosphoramidon and thiorphan. Thus, NEP/CD10 is differentially expressed in pancreatic tumors and might be involved in the proliferative activity of pancreatic cancer cells. However, further studies are needed to provide more detailed information of the role of NEP/CD10 under physiological and pathophysiological conditions of the pancreas. © 2007 Wiley‐Liss, Inc.
Increased expression of estrogen‐related receptor α (ERRα) is a negative prognostic predictor in human prostate cancer
Authors: Fujimura Tetsuya , Takahashi Satoru , Urano Tomohiko , Kumagai Jinpei , Ogushi Tetsuo , Horie‐Inoue Kuniko , Ouchi Yasuyoshi , Kitamura Tadaichi , Muramatsu Masami , Inoue Satoshi
Published: February 2007

The nuclear receptor ERRα (estrogen‐related receptor α) is known to modulate the estrogen‐signaling pathway, but the biological significance of ERRα in the prostate remains unclear. We investigated the expression of ERRα in human prostate tissues and cancer cell lines to evaluate the potential roles of the receptor in prostate cancer (PC). Western blot analysis of ERRα was performed in three cell lines of human PC (LNCaP, DU145 and PC‐3). The expressions of ERRα in cancerous lesions (n = 106) and benign foci (n = 99) of 106 surgically obtained prostate specimens were evaluated by immunohistochemistry. The relationships between the ERRα expression and clinicopathological features were evaluated. Western blot analysis using the polyclonal anti‐ERRα antibody detected a 52 kD band in all three PC cell lines. Positive immunostaining of ERRα in the nuclei was found in 73 (69%) cancerous and 47 (47.5%) benign epithelium, whereas the stromal tissues were negative for ERRα. The mean immunoreactivity score (IR score) of the cancerous lesions (3.5 ± 2.6) was significantly higher than that of the benign foci (1.8 ± 2.1) (p < 0.0001). The IR score of the cancerous lesions significantly correlated with the Gleason score (p = 0.0135). Univariate and multivariate hazard analyses revealed significant correlations between elevated ERRα expression and poor cancer‐specific survival (p = 0.0141 and 0.0367, respectively). The enhanced expression of ERRα might play a role in the development of human PC and serve as a significant prognostic factor for the disease. © 2006 Wiley‐Liss, Inc.
Increased expression of Dyrk1a in HPV16 immortalized Keratinocytes enable evasion of apoptosis
Authors: Chang Hung‐Shu , Lin Ching‐Hui , Yang Chien‐Hui , Yen Ming‐Shyen , Lai Chiung‐Ru , Chen Yi‐Rong , Liang Yuh‐Jin , Yu Winston C.Y.
Published: February 2007

Immortalization is a critical event in virus‐related oncogenesis. No enough information, however, is currently available to elucidate the changes that occur in cellular molecules during immortalization. To identify potential cellular markers or regulators involving in immortalization, a paired‐cell model of primary foreskin keratinocytes (FK) and HPV16 immortalized foreskin keratinocytes were established. Using mRNA differential display, RT‐PCR and Northern blot methods, we have identified and confirmed that Dyrk1a (dual‐specificity tyrosine‐phosphorylated and regulated kinase 1A) is present and increased in HPV16 immortalized cells, but is absent in primary keratinocytes. Moreover, transfection of E7 siRNA oligo into immortalized cells leads to a diminishing E7 expression and the eventual disappearance of Dyrk1a. Similar results of Dyrk1a expressional differences could also be seen when tissue specimens were compared using LCM/real‐time PCR and immunohistochemistry analysis; malignant cervical lesions contain significantly more DYRK1A than normal tissue. It was also demonstrated that raised DYRK1A could rearrange the cellular localization of FKHR (forkhead in rhabdomyosarcoma), an apoptosis activator, and suppress BAD. Importantly, this phenomenon can be reversed when endogenous Dyrk1a was knocked down in immortalized cells by RNA interference. These results suggest that the raised Dyrk1a in HPV16 immortalized keratinocytes and cervical lesions may serve as a candidate antiapoptotic factor in the FKHR regulated pathway and initiate immortalization and tumorigenesis gradually. © 2007 Wiley‐Liss, Inc.
Immunological characterization of missense mutations occurring within cytotoxic T cell‐defined p53 epitopes in HLA‐A*0201+ squamous cell carcinomas of the head and neck
Authors: Ito Daisuke , Visus Carmen , Hoffmann Thomas K. , Balz Vera , Bier Henning , Appella Ettore , Whiteside Theresa L. , Ferris Robert L. , DeLeo Albert B.
Published: February 2007

Previous analyses of p53 in 40 HLA‐A*0201(HLA‐A2)+ squamous cell carcinomas of the head and neck (SCCHN) indicated that 6/13 p53 missense mutations that were detected, S149C, T150R, V157F, Y220C, Y220H and E271K, occurred within HLA‐A2‐restricted cytotoxic T lymphocyte (CTL)‐defined p53 epitopes. Of the 6, the p53 S149C, Y220C and Y220H peptides were immunogenic. Anti‐p53 mutant S149C and Y220H effector cells cross‐reacted against the parental wild type sequence (wt) p53 peptides, whereas anti‐p53 Y220C effector cells were specific for the mutant peptide, p53 Y220C cDNA‐transfected HLA‐A2+ SaOS cells, and an HLA‐A2+ SCCHN cell line naturally expressing the mutation. These results indicate that the p53 Y220C mutation can be processed and presented for CD8+ T cell recognition. Furthermore, using an autologous PBMC/tumor system, anti‐p53 Y220C peptide‐effector cells recognizing the autologous tumor could also be generated. Our analysis of p53 in 10 additional HLA‐A2+ SCCHN tumors detected the p53 Y220C in 2/10 tumors raising the overall frequency of the p53 Y220C mutation to 6/50 (12%) HLA‐A2+ SCCHN tumors. In contrast, independent of their HLA class I genotypes, the p53 Y220C mutation frequency for all human tumors analyzed to date is ∼1.5%. This unexpectedly high frequency of the p53 Y220C mutation in HLA‐A2+ SCCHN suggests that vaccines targeting this mutation would not only be expected to induce robust anti‐tumor immune responses in HLA‐A2+ subjects, but also be more widely applicable than previously envisioned for any given p53 missense mutation. © 2007 Wiley‐Liss, Inc.
KIT gene in pediatric osteosarcomas: Could it be a new therapeutic target?
Authors: Entz‐Werle Natacha , Gaub Marie‐Pierre , Lavaux Thomas , Marcellin Luc , Metzger Nadia , Marec‐Berard Perrine , Schmitt Claudine , Brugiere Laurence , Kalifa Chantal , Tabone Marie‐Dominique , Pacquement Hélène , Gentet Philippe , Lutz Patrick , Oudet Pierre , Babin Annie
Published: February 2007

In our previous study, a frequent rearrangement at 4q12 has been identified by allelotyping in our large and homogeneous population of pediatric osteosarcomas and it was significantly linked to c‐kit protein overexpression. To confirm and understand the involvement of KIT in this tumor, the next step of the study was designed to detect the potential mutations of KIT gene by sequencing the frequently mutated exons 6, 8, 10, 11, 13, 17 and 21 and, in case of unmutated samples, to confirm the genomic amplifications of the wild‐type receptor by real‐time quantitative PCR (QPCR). A new microsatellite and QPCR targeting PDGFRA was also added to check the accuracy of the 4q11‐12 locus. These techniques were performed in 74 pediatric high‐grade osteosarcomas treated with the OS94 protocol. Surprisingly, no mutations were found, but, only DNA amplification of KIT gene in the entire population. PDGFRA gene QPCR revealed an unexpected result of predominant deletions in the rearranged tumors. All these results confirm the major role of the 4q11‐12 locus and specifically the involvement of c‐kit wild‐type receptor overexpression in pediatric osteosarcomas and leads us to believe that inhibitors targeting this receptor could have a therapeutic effect in a selected group of patients. © 2007 Wiley‐Liss, Inc.
Evaluation of a new p16INK4A ELISA test and a high‐risk HPV DNA test for cervical cancer screening: Results from proof‐of‐concept study
Authors: Mao Constance , Balasubramanian Akhila , Yu Mujun , Kiviat Nancy , Ridder Ruediger , Reichert Anja , Herkert Matthias , Doeberitz Magnus von Knebel , Koutsky Laura A.
Published: February 2007

p16INK4a, a cell cycle regulation protein, accumulates in abnormal epithelial cells infected with high‐risk human papilloma virus (HPV). In immunostaining studies, p16INK4a has shown potential as a marker of high grade cervical intraepithelial neoplasia (CIN) and invasive cervical cancer. To evaluate its potential use in cervical cancer screening, we conducted a feasibility study to compare the performance of a new enzyme linked immunosorbant assay (ELISA) for p16INK4a (mtm laboratories, Heidelberg, Germany) to that of the Hybrid capture 2™ (hc2) test for high‐risk HPV DNA for the detection of CIN3. Three hundred and nineteen women were referred from Western Washington Planned Parenthood clinics for colposcopy examination and cervical biopsy because of abnormal Pap test results. Cervical samples were obtained from study participants for p16INK4a ELISA, liquid‐based cytology and hc2. The order (first and second) for obtaining samples for cervical cytology and p16INK4a ELISA changed with every other subject. Concentrations of p16INK4a protein were higher when the sample was taken before the cytology. The sensitivity of p16INK4a ELISA (concentration ≥ 8 units/ml) taken as first sample was 90.0% for CIN3, and the sensitivity of HC2 taken as a second sample was 85%. In the same group, the specificity of p16INK4a ELISA (46.9%) was slightly better than hc2 (35.4%) Results from this proof‐of‐concept study suggest that p16INK4a ELISA has a similar sensitivity and slightly better specificity for CIN3 compared to hc2. These findings support proceeding with a larger study with samples from a population of women presenting for routine cytology screening. © 2007 Wiley‐Liss, Inc.
Avoiding calcineurin inhibitors in the early post‐operative course in high‐risk liver transplant recipients: The role of extracorporeal photopheresis
Authors: Urbani Lucio , Mazzoni Alessandro , De Simone Paolo , Catalano Gabriele , Coletti Laura , Petruccelli Stefania , Biancofiore Gianni , Bindi Lucia , Scatena Fabrizio , Filipponi Franco
Published: February 2007

The aim of this work is to report on the results of a single‐center, prospective study on the feasibility of calcineurin‐inhibitor (CNI)‐staggered immunosuppression by use of extracorporeal photopheresis (ECP) in liver transplant (LT) recipients at risk of renal and neurological complications.Patients were matched on a 1:1 basis with historical controls on standard CNI immunosuppression. ECP patients were treated with ECP plus antimetabolites and/or steroids, while CNIs were withheld until clinically indicated. Thirty‐six patients were evaluated: 18 ECP patients and 18 controls. ECP was tolerated in 100% of cases. CNI were introduced at a median of 8 days (4–55) in 17 ECP patients, while one patient was on a fully CNI‐sparing regimen 22 months after LT. Acute rejection occurred in 27.7% patients in ECP (5/18) versus 16.7% in controls (3/18) (P = ns) with a shorter time to rejection in ECP (36 ± 31.3 days vs. 83.6 ± 65.6 days; P = ns). All rejection episodes were amenable to medical treatment. Neurological and renal complications occurred in 22.2% (4/18) of patients in either group, but led to in‐hospital mortality in 3 patients among controls versus 1 in ECP (P = ns). One‐, 6‐, and 12‐month survival rates were 94.4, 88.1, and 88.1% in ECP versus 94.4, 77.7, and 72.2% among controls (P < 0.0001). ECP seems to allow for management of high‐risk LT recipients in the early post‐transplant course and reduction of CNI‐related mortality. Continued data validation is favored to assess the impact of ECP on long‐term graft and patient survival. J Clin Apheresis 2007. © 2007 Wiley‐Liss, Inc.