bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrophobic recovery behavior of PMMA and PEA ionomers treated with PSII
Authors: Song Ju‐Myung , Kim Youngsoo , Han Seunghee , Lee Yeonhee , Kim Joon‐Seop
Published: June 2003

The surfaces of poly(methyl methacrylate) (PMMA)‐based and poly(ethyl acrylate) (PEA)‐based ionomers were treated either with plasma or with plasma source ion implantation (PSII), and their hydrophobic recovery behavior was studied by measuring water contact angles. It was found that the hydrophobic recovery of the plasma‐treated and PSII‐treated surfaces of PMMA ionomers was much slower than that of the acid‐form copolymers. This was due to the presence of hydrophilic ionic groups on the ionomer surface. In addition, in the case of the PMMA ionomers, a slow hydrophobic recovery behavior for a long period of time was observed. In the case of the PEA ionomer, the water contact angle values were found to be larger than those for the PMMA ionomers. When the contact angle values of the PMMA and PEA ionomers were compared to those of polystyrene (PS) ionomers, it was found that the order of ionomers showing higher angle value at comparable aging time was as follows: PS ionomer > PEA ionomer > PMMA ionomer. This was due to the difference in polarity and matrix glass transition temperature of the ionomers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3100–3106, 2003
Circular dichroism spectroscopy of conformers of (guanine + adenine) repeat strands of DNA
Authors: Kejnovská Iva , Kypr Jaroslav , Vorlíčková Michaela
Published: June 2003

(Guanine+adenine) strands of DNA are known to associate into guanine tetraplexes, homodimerize into parallel or antiparallel duplexes, and fold into a cooperatively melting single strand resembling the protein alpha helix. Using CD spectroscopy and other methods, we studied how this conformational polymorphism depended on the primary structure of DNA. The study showed that d(GGGA)5 and d(GGA)7 associated into homoduplexes at low salt or in the presence of LiCl but were prone to guanine tetraplex formation, especially in the presence of KCl. In addition, they yielded essentially the same CD spectrum in the presence of ethanol as observed with the ordered single strand of d(GA)10. Strands of d(GA)10, d(GGAA)5, d(GAA)7, and d(GAAA)5 associated into homoduplexes in both LiCl and KCl solutions, but not into guanine tetraplexes. d(GAAA)5 and d(GAA)7 further failed to form the single‐stranded conformer in aqueous ethanol. Adenine protonation, however, stabilized the single‐stranded conformer even in these adenine‐rich fragments. The ordered single strands, homoduplexes as well as the guanine tetraplexes, all provided strikingly similar CD spectra, indicating that all of the conformers shared similar base stacking geometries. The increasing adenine content only decreased the conformer thermostability. Chirality 15:584–592, 2003. © 2003 Wiley‐Liss, Inc.
Chiral HPLC method for chiral purity determination of paroxetine drug substance
Authors: Zukowski Janusz , Brightwell Malcolm , de Biasi Vern
Published: June 2003

This article describes a chiral HPLC method for (+) trans isomer of paroxetine in a paroxetine drug substance. The method development was performed to establish a suitable HPLC system in order to separate both enantiomers. It was found that a system based on a Chiralpak AD column was suitable for the analysis. Proper column maintenance and the optimized eluent composition allowed good reproducibility and sensitivity for the method. The method was also checked on a number of different columns using different HPLC equipment and gave both reproducible chromatography and reproducible quantitative results. Chirality 15:600–604, 2003. © 2003 Wiley‐Liss, Inc.
A visual servoing system with feature prediction using a motion observer
Authors: Saruta Kunihiko , Fujimoto Hiroshi , Hori Yoichi
Published: June 2003

A visual servo is an eye‐in‐hand robot system that directly uses real‐time visual information for control. This paper proposes a novel visual servoing system with motion observer (MOB)‐based feature prediction. The position of the target object cannot be observed directly. The motion observer is designed as a minimum‐order observer and is useful for high‐performance servoing. The effectiveness of the proposed method is shown by simulations and experiments. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(1): 67–73, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10154
Three‐phase immittance converter
Authors: Irie Hisaichi , Nishisako Takayuki
Published: June 2003

The immittance converter has an input impedance that is proportional to the admittance of a load connected across its output terminals. In this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, a constant‐voltage source is converted into a constant‐current source and a constant‐current source into a constant‐voltage source. The immittance converters consisting of only passive elements (inductors L and capacitors C) are suitable for use in the high‐frequency links in power electronics applications.

Previously, we proposed several types of immittance converters and some applications to power electronics equipment. In this paper, we propose a new three‐phase immittance converter consisting of three L and C elements each to obtain an alternating current source from a three‐phase voltage source without control.

This paper presents a configuration of the new three‐phase immittance converter that operates in either anti‐phase or in‐phase modes between the input voltage and the output voltage, and its voltage–current conversion characteristics and efficiency characteristics. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(1): 52– 58, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10169
Characteristic‐varying systems in the D‐Module: Their properties of existence, realization, and stability
Authors: Shinnaka Shinji
Published: June 2003

Signal processing based on frequency polarity has been attracting wide attention due to its potential applications to industry. It is popular to employ two vector rotators for such signal processing. However, it has very recently been reported that an equivalent signal processing effect can be attained in a much simpler manner using two‐input two‐output filters in the D‐module. This paper further investigates a class of characteristic‐varying systems in the D‐module, which contains the filters in the D‐module as a special case, and gives new analytical results on their properties from the viewpoints of existence, realization, and stability. If the results are applied to filter problems, n‐th order filters in the D‐module in new forms can be easily and directly obtained, whose stability and response equivalent to the associated filters with vector rotators are guaranteed. If the results are applied to AC motor modeling problems, dynamic models and block diagrams of AC motors in general reference frame are easily and directly obtained. Very general and useful analyses are given for a newly proposed class of characteristic‐varying systems in the D‐module that have potential usefulness in various industrial applications including control of magnetic bearing system, analyses and active compensations of power systems, and sensorless drives of AC motors. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(1): 39–51, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10171
Empirical Bayes estimators and non‐parametric mixture models for space and time–space disease mapping and surveillance
Authors: Böhning Dankmar
Published: June 2003

The analysis of the geographic variation of disease and its representation on a map is an important topic in epidemiological research and in public health in general. Identification of spatial heterogeneity of relative risk using morbidity and mortality data is required. Frequently, interest is also in the analysis of space data with respect to time, where typically data are used which are aggregated in certain time windows like 5 or 10 years. The occurrence measure of interest is usually thestandardized mortality (morbidity) ratio(SMR). It is well known that disease maps in space or in space and time should not solely be based upon the crude SMR but rather some smoothed version of it. This fact has led to a tremendous amount of theoretical developments in spatial methodology, in particular in the area of hierarchical modeling in connection with fully Bayesian estimation techniques like Markov chain Monte Carlo. It seems, however, that at the same time, where these theoretical developments took place, on the practical side only very few of these developments have found their way into daily practice of epidemiological work and surveillance routines. In this article we focus on developments that avoid the pitfalls of the crude SMR and simultaneously retain a simplicity and, at least approximately, the validity of more complex models. After an illustration of the typical pitfalls of the crude SMR the article is centered around three issues: (a) the separation of spatial random variation from spatial structural variation; (b) a simple mixture model for capturing spatial heterogeneity; (c) an extension of this model for capturing temporal information. The techniques are illustrated by numerous examples. Public domain software like Dismap is mentioned that enables easy mixture modeling in the context of disease mapping. Copyright © 2003 John Wiley & Sons, Ltd.
Space varying coefficient models for small area data
Authors: Assunção Renato M.
Published: June 2003

Many spatial regression problems using area data require more flexible forms than the usual linear predictor for modelling the dependence of responses on covariates. One direction for doing this is to allow the coefficients to vary as smooth functions of the area's geographical location. After presenting examples from the scientific literature where these spatially varying coefficients are justified, we briefly review some of the available alternatives for this kind of modelling. We concentrate on a Bayesian approach for generalized linear models proposed by the author which uses a Markov random field to model the coefficients' spatial dependency. We show that, for normally distributed data, Gibbs sampling can be used to sample from the posterior and we prove a result showing the equivalence between our model and other usual spatial regression models. We illustrate our approach with a number of rather complex applied problems, showing that the method is computationally feasible and provides useful insights in substantive problems. Copyright © 2003 John Wiley & Sons, Ltd.
A space–time analysis of the relationship between material deprivation and mortality for lung cancer
Authors: Dreassi Emanuela
Published: June 2003

The relationship between socioeconomic factors and mortality for lung cancer is investigated. A space–time hierarchical Bayesian model with time dependent covariates, to identify the proper lag time on which lung cancer mortality is affected by socioeconomic factors, is adopted. An example of lung cancer in males in Tuscany (Italy) during the period 1971–99 is provided. Results confirm the presence of an association between mortality for lung cancer and socioeconomic factors with a temporal lag (latency time) of 10 years. Copyright © 2003 John Wiley & Sons, Ltd.
Oogenesis and plasma levels of sex steroids in cultured females of brown trout (Salmo trutta linnaeus, 1758) in Chile
Authors: Estay Francisco , Díaz Andrés , Pedrazza Rodrigo , Colihueque Nelson
Published: June 2003

Naturalized brown trout populations in Chile are a valuable genetic resource with aquaculture potential. The oogenesis of a three‐year‐old brown trout cultured population was studied in southern Chile. Gonadosomatic index (GSI), oocyte growth, gonadal microscopic characteristics, and plasma levels of estradiol–17β (E2), testosterone (T), and 17α–hydroxyprogesterone (17α–HP) were measured bimonthly for a nine‐month period before spawning. The maximum GSI level (22%) was similar to that described for other salmonids, although it was reached in May, more than one month before the population started spawning. Oocyte growth increases strongly from January when diameter reaches more than 1 mm. The vitellogenic period (six‐seven months) is consistent with the long vitellogenesis, described for salmonid females maturing at three years old. E2 shows a slow increase from November, reaching its peak value in March (65.2±0.7 ng/ml), during maximal vitellogenic activity. T increases as oogenesis progresses, reaching a maximum of 90±20 ng/ml during May, and falling considerably during ovulation. Following a typical pattern of progestogens in salmonid oogenesis, 17α–HP stays at basal levels during most of oogenesis, but experiences a strong surge (2.0±0.4 ng/ml) just before ovulation. J. Exp. Zool. 298A:60–66, 2003. © 2003 Wiley‐Liss, Inc.
Putative serotonin reuptake inhibitor‐induced spawning and parturition in freshwater bivalves is inhibited by mammalian 5‐HT2 receptor antagonists
Authors: Fong Peter P. , Philbert Caroline M. , Roberts Brian J.
Published: June 2003

Selective serotonin reuptake inhibitors (SSRIs) can mimic the physiological actions of serotonin, and in bivalve molluscs they induce zebra mussel spawning and fingernail clam parturition. We have elucidated further the pharmacology of SSRI‐induced spawning and part‐urition by blocking these reproductive processes with two mammalian 5‐HT2 receptor antagonists, cyproheptadine and mianserin. These two antagonists were potent inhibitors of both spawning and parturition induced by the SSRIs fluvoxamine, fluoxetine, and zimelidine. In zebra mussels, both cyproheptadine and mianserin significantly blocked spawning induced by fluvoxamine and by zimelidine. In the fingernail clams Sphaerium spp., both cyproheptadine and mianserin blocked fluvoxamine‐induced parturition. A possible mechanism of action for SSRI‐induced spawning and parturition in bivalves is suggested. J. Exp. Zool. 298A:67–72, 2003. © 2003 Wiley‐Liss, Inc.
Error analysis of the fast inhomogeneous plane wave algorithm for 2D free‐space cases
Authors: Ohnuki Shinichiro , Chew Weng Cho
Published: June 2003

The fast inhomogeneous plane wave algorithm is another approach of the diagonal factorization of the Green's function which is represented by the infinite integration. In this paper, we discuss the error analysis in terms of the truncation of the integration path and the indispensable extrapolation process. Finally, this algorithm will be shown to be error controllable. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 300–304, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11043
Turkey
Authors: Cavusgil S. Tamer , Civi Emin , Tutek H. Hulya , Dalgic Tevfik
Published: June 2003

The Turkish Republic was founded in 1923, following the fall of the Ottoman Empire. Turkey is strategically
positioned at the crossroads of Europe, the Black Sea region, and the Turkic‐speaking republics of
Central Asia. It is also situated on the Mediterranean coast at close proximity to the Middle East, the Gulf
States, and North Africa. It thus offers an excellent base for economic activities throughout the region. The
country was a gateway from the ancient Silk Road to new markets and today is becoming a powerful focal point as
a cultural and political intermediary as well as a regional trade center of growing importance. Turkey is the
17th largest economy in the world (Economist, 2003; World Bank, 2001).

Turkish culture, history, and people have always fascinated scholars. In recent years, the country also has
captured the attention of Western companies and investors. Once highly insular, the Turkish economy has been
transformed over the past two decades into a vibrant liberal market within a rapidly modernizing society. It is
regarded by the U.S. Department of Commerce as one of the top emerging markets.

This article will explore the foundations of the Turkish economy, business system, and business culture from
the perspective of foreign companies. Following a brief overview of the economy, the country's market
potential is discussed. Next, entry strategies—including potential partnerships with indigenous
firms—are recommended. Finally, we offer insights into the business culture, and provide tips for working
effectively with Turkish business people. © 2003 Wiley Periodicals, Inc.
Atypical properties displayed by annexin A9, a novel member of the annexin family of Ca2+ and lipid binding proteins
Authors: Goebeler Verena , Ruhe Daniela , Gerke Volker , Rescher Ursula
Published: June 2003

Annexin A9 is a novel member of the annexin family of Ca2+ and phospholipid binding proteins which has so far only been identified in EST data bases and whose deduced protein sequence shows mutations in residues considered crucial for Ca2+ coordination in other annexins. To elucidate whether the annexin A9 protein is expressed as such and to characterize its biochemical properties we probed cell extracts with specific anti‐annexin A9 antibodies and developed a recombinant expression system. We show that the protein is found in HepG2 hepatoma cell lysates and that a green fluorescent protein‐tagged form is abundantly expressed in the cytosol of HeLa cells. Recombinant expression in bacteria yields a soluble protein that can be enriched by conventional chromatographic procedures. The protein is capable of binding phosphatidylserine containing liposomes albeit only at Ca2+ concentrations exceeding 2 mM. Moreover and in contrast to other annexins this binding appears to be irreversible as the liposome‐bound annexin A9 cannot be released by Ca2+ chelation. These results indicate that annexin A9 is a unique member of the annexin family whose intracellular activity is not subject to Ca2+ regulation.
Cell surface expression of functional hepatitis C virus E1 and E2 glycoproteins
Authors: Drummer Heidi E. , Maerz Anne , Poumbourios Pantelis
Published: June 2003

Hepatitis C virus (HCV) glycoproteins E1 and E2 are believed to be retained in the endoplasmic reticulum (ER) or cis‐Golgi compartment via retention signals located in their transmembrane domains. Here we describe the detection of E1 and E2 at the surface of transiently transfected HEK 293T and Huh7 cells. Surface‐localized E1E2 heterodimers presented exclusively as non‐covalently associated complexes. Surface‐expressed E2 contained trans‐Golgi modified complex/hybrid type carbohydrate and migrated diffusely between 70 and 90 kDa while intracellular E1 and E2 existed as high mannose 35 kDa and 70 kDa precursors, respectively. In addition, surface‐localized E1E2 heterodimers were incorporated into E1E2‐pseudotyped HIV‐1 particles that were competent for entry into Huh7 cells. These studies suggest that functional HCV glycoproteins are not retained exclusively in the ER and transit through the secretory pathway.
Fluorescence correlation spectroscopy analysis of the dynamics of tubulin interaction with RB3, a stathmin family protein
Authors: Krouglova Tatiana , Amayed Phedra , Engelborghs Yves , Carlier Marie-France
Published: June 2003

We have used fluorescence correlation spectroscopy to analyze the interaction of GTP‐tubulin with rhodamine‐labeled RB3, a neural protein of the stathmin family, and to determine the kinetic pathway of the association process. RB3 displayed slow association–dissociation kinetics with tubulin depending on the square of the tubulin concentration. The values of the apparent association and dissociation rate constants of the complex of two tubulin dimers and RB3 are determined to be (3.52±0.14)×10−3 μM−2/s and (1.9±0.6)×10−3 s−1 respectively. The value of the equilibrium dissociation constant for the first tubulin–RB3 interaction is estimated to be ⩾7 μM at 20°C.
The SUMO pathway is required for selective degradation of DNA topoisomerase IIβ induced by a catalytic inhibitor ICRF‐1931
Authors: Isik Sevim , Sano Kuniaki , Tsutsui Kimiko , Seki Masayuki , Enomoto Takemi , Saitoh Hisato , Tsutsui Ken
Published: June 2003

DNA topoisomerase I and II have been shown to be modified with a ubiquitin‐like protein SUMO in response to their specific inhibitors called ‘poisons’. These drugs also damage DNA by stabilizing the enzyme–DNA cleavable complex and induce a degradation of the enzymes through the 26S proteasome system. A plausible link between sumoylation and degradation has not yet been elucidated. We demonstrate here that topoisomerase IIβ, but not its isoform IIα, is selectively degraded through proteasome by exposure to the catalytic inhibitor ICRF‐193 which does not damage DNA. The β isoform immunoprecipitated from ICRF‐treated cells was modified by multiple modifiers, SUMO‐2/3, SUMO‐1, and polyubiquitin. When the SUMO conjugating enzyme Ubc9 was conditionally knocked out, the ICRF‐induced degradation of topoisomerase IIβ did not occur, suggesting that the SUMO modification pathway is essential for the degradation.
Inhibition of Aβ production and APP maturation by a specific PKA inhibitor
Authors: Su Yuan , Ryder John , Ni Binhui
Published: June 2003

Alzheimer's disease is characterized pathologically by extracellular amyloid β protein (Aβ) deposition in the brain. The Aβ peptide, a 39–42 amino acid fragment, is derived from defined proteolysis of the amyloid precursor protein (APP) [Glenner et al., Appl. Pathol. 2 (1984) 357–369; Selkoe, Neuron 6 (1991) 487–498] and is the primary component of senile plaques. Although it is known that intracellular APP is subjected to posttranslational modification, the molecular mechanism that regulates the APP processing is not completely clear. In the present study, we demonstrates that H89, a specific inhibitor for cAMP dependent protein kinase A (PKA), inhibits Aβ production and APP secretion in a dose dependent manner in cells stably transfected with human APP bearing a ‘Swedish mutation’. Concurrent with the effect, H89 inhibits C‐terminal fragment of the APP. We also found that the PKA inhibitor abolishes the mature form of intracellular APP and accumulates the immature form. Finally, direct administration of H89 into brains of transgenic mice overexpressing human APP shows that the compound inhibits Aβ production in the hippocampal region. Our data suggests that PKA plays an important role in the maturation of APP associated with APP processing.
Functional interaction of the subunit 3 of RNA polymerase II (RPB3) with transcription factor‐4 (ATF4)
Authors: De Angelis Roberta , Iezzi Simona , Bruno Tiziana , Corbi Nicoletta , Di Padova Monica , Floridi Aristide , Fanciulli Maurizio , Passananti Claudio
Published: June 2003

RPB3 is a core subunit of RNA polymerase II (pol II) that, together with the RPB11 subunit, forms the heterodimer considered as a functional counterpart of the bacterial α subunit homodimer involved in promoter recognition. We previously employed the yeast two‐hybrid system and identified an interaction between RPB3 and the myogenic transcription factor myogenin, demonstrating an involvement of this subunit in muscle differentiation. In this paper we report the interaction between RPB3 and another known transcription factor, ATF4. We found that the intensity of the interaction between RPB3 and ATF4 is similar to the one between RPB3 and myogenin. This interaction involves an RPB3 specific region not homologous to the prokaryotic α subunit. We demonstrated that RBP3 is able to enhance ATF4 transactivation, whereas the region of RPB3 (Sud) that contacts ATF4, when used as a dominant negative, markedly inhibits ATF4 transactivation activity. Interestingly, ATF4 protein level, as reported for its partner RPB3, increases during C2C7 cell line muscle differentiation.
Preferential closed channel blockade of HERG potassium currents by chemically synthesised BeKm‐1 scorpion toxin
Authors: Milnes James T , Dempsey Christopher E , Ridley John M , Crociani Olivia , Arcangeli Annarosa , Hancox Jules C , Witchel Harry J
Published: June 2003

The scorpion toxin peptide BeKm‐1 was synthesised by fluorenylmethoxycarbonyl solid phase chemistry and folded by air oxidation. The peptide's effects on heterologous human ether‐a‐go‐go‐related gene potassium current (I
HERG) in HEK293 cells were assessed using ‘whole‐cell’ patch clamp. Blockade of I
HERG by BeKm‐1 was concentration‐dependent, temperature‐dependent, and rapid in onset and reversibility. Blockade also exhibited inverse voltage dependence, inverse dependence on duration of depolarisation, and reverse use‐ and frequency‐dependence. Blockade by BeKm‐1 and recombinant ergtoxin, another scorpion toxin known to block HERG, differed in their recovery from HERG current inactivation elicited by strong depolarisation and in their ability to block HERG when the channels were already activated. We conclude that synthetic BeKm‐1 toxin blocks HERG preferentially through a closed (resting) state channel blockade mechanism, although some open channel blockade also occurs.
Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel1
Authors: Corzo Gerardo , Gilles Nicolas , Satake Honoo , Villegas Elba , Dai Li , Nakajima Terumi , Haupt Joachim
Published: June 2003

Six peptide toxins (Magi 1–6) were isolated from the Hexathelidae spider Macrothele gigas. The amino acid sequences of Magi 1, 2, 5 and 6 have low similarities to the amino acid sequences of known spider toxins. The primary structure of Magi 3 is similar to the structure of the palmitoylated peptide named PlTx‐II from the North American spider Plectreurys tristis (Plectreuridae). Moreover, the amino acid sequence of Magi 4, which was revealed by cloning of its cDNA, displays similarities to the Na+ channel modifier δ‐atracotoxin from the Australian spider Atrax robustus (Hexathelidae). Competitive binding assays using several 125I‐labelled peptide toxins clearly demonstrated the specific binding affinity of Magi 1–5 to site 3 of the insect sodium channel and also that of Magi 5 to site 4 of the rat sodium channel. Only Magi 6 did not compete with the scorpion toxin LqhαIT in binding to site 3 despite high toxicity on lepidoptera larvae of 3.1 nmol/g. The K
is of other toxins were between 50 pM for Magi 4 and 1747 nM for Magi 1. In addition, only Magi 5 binds to both site 3 in insects (K
i=267 nM) and site 4 in rat brain synaptosomes (K
i=1.2 nM), whereas it showed no affinities for either mammal binding site 3 or insect binding site 4. Magi 5 is the first spider toxin with binding affinity to site 4 of a mammalian sodium channel.
Late ischemic preconditioning of the myocardium alters the expression of genes involved in inflammatory response
Authors: Zubakov Dmitrij , Hoheisel Jörg D , Kluxen Franz-Werner , Brändle Marian , Ehring Thomas , Hentsch Bernd , Frohme Marcus
Published: June 2003

Myocardial ischemic preconditioning (IPC) is a potent endogenous mechanism of cardioprotection against ischemia–reperfusion injury. In this study we focused on the second phase of IPC as the most interesting in terms of therapeutic implementations. We aimed at the detection of genes, which are differentially expressed at 16 h after reperfusion. Preconditioning of canine myocardium was initiated by 5 min occlusion of the left anterior descending coronary artery with subsequent reperfusion. cDNA representational difference analysis in combination with microarray hybridization and reverse transcription polymerase chain reaction were used to reveal the changes in gene expression in canine hearts. We found that functionally related genes for tristetraproline (TTP), selectin E, matrix metalloproteinase 9, and tumor necrosis factor‐α were highly upregulated at the late phase of IPC. The upregulation of TTP gene at the late phase of IPC, reported here for the first time, may represent a cardioprotective mechanism, which could be a promising perspective in clinical interventions against ischemia–reperfusion injuries of the heart.
The first committed step reaction of caffeine biosynthesis: 7‐methylxanthosine synthase is closely homologous to caffeine synthases in coffee (Coffea arabica L.)1
Authors: Mizuno Kouichi , Kato Misako , Irino Fumi , Yoneyama Naho , Fujimura Tatsuhito , Ashihara Hiroshi
Published: June 2003

In coffee and tea plants, caffeine is synthesized from xanthosine via a pathway that has three methylation steps. We identified and characterized the gene encoding the enzyme for the first methylation step of caffeine biosynthesis. The full‐length cDNA of coffee tentative caffeine synthase 1, CtCS1, previously isolated by the rapid amplification of cDNA ends was translated with an Escherichia coli expression system and the resultant recombinant protein was purified using Ni‐NTA column. The protein renamed CmXRS1 has 7‐methylxanthine synthase (xanthosine:S‐adenosyl‐L‐methionine methyltransferase) activity. CmXRS1 was specific for xanthosine and xanthosine 5′‐monophosphate (XMP) could not be used as a substrate. The K
m value for xanthosine was 73.7 μM. CmXRS1 is homologous to coffee genes encoding enzymes for the second and third methylation steps of caffeine biosynthesis.
IL‐1β‐dependent activation of NF‐κB mediates PGE2 release via the expression of cyclooxygenase‐2 and microsomal prostaglandin E synthase
Authors: Catley Matthew C. , Chivers Joanna E. , Cambridge Lisa M. , Holden Neil , Slater Donna M. , Staples Karl J. , Bergmann Martin W. , Loser Peter , Barnes Peter J. , Newton Robert
Published: June 2003

Prostaglandin (PG) E2 release is induced in pulmonary A549 cells by the NF‐κB‐activating stimuli interleukin‐1β (IL‐1β) and phorbol 12‐myristate 13‐acetate (PMA). Adenoviral over‐expression of IκBαΔN, a dominant NF‐κB inhibitor, prevents NF‐κB‐dependent transcription and was used to qualify the role of NF‐κB in the release of PGE2. IκBαΔN repressed IL‐1β‐induced, but not PMA‐induced, cycloxygenase‐2 (COX‐2) and microsomal prostaglandin E synthase (mPGES) expression. These data conclusively demonstrate a substantial role for NF‐κB in the co‐ordinate induction of COX‐2, mPGES and in the corresponding release of PGE2 by IL‐1β. However, other pathways are primarily responsible for PGE2 release induced by PMA.
The Raf/MEK inhibitor PD98059 enhances ERK1/2 phosphorylation mediated by peroxynitrite via enforced mitochondrial formation of reactive oxygen species
Authors: Cerioni Liana , Palomba Letizia , Cantoni Orazio
Published: June 2003

Exposure of PC12 cells to 100 μM peroxynitrite promotes phosphorylation of extracellular signal‐regulated kinases 1 and 2 (ERK1/2) sensitive to PD98059 or U0126. At higher concentrations, however, ERK1/2 phosphorylation was prevented by U0126 and increased by PD98059 via a U0126‐sensitive mechanism. PD98059, unlike U0126, enhanced the peroxynitrite‐dependent formation of reactive oxygen species (ROS). These results, along with others obtained using respiratory chain inhibitors and respiration‐deficient cells, lead to the conclusion that PD98059, while effectively inhibiting the peroxynitrite‐induced Raf/MEK signaling leading to ERK1/2 phosphorylation, promotes an enforced mitochondrial formation of ROS inducing ERK1/2 phosphorylation via a Raf‐1‐independent/MEK‐dependent mechanism.
Specific covalent binding of a NF‐κB decoy hairpin oligonucleotide targeted to the p50 subunit and induction of apoptosis
Authors: Lesage Denis , Metelev Valeri , Borisova Oksana , Dolinnaya Nina , Oretskaya Tatiana , Baran-Marszak Fanny , Taillandier Eliane , Raphael Martine , Fagard Remi
Published: June 2003

The NF‐κB transcriptional factor regulates various functions such as immune responses, cellular growth and development, and is frequently activated in tumor cells. Thus, inhibition of NF‐κB could suppress tumor cell growth. Using a decoy synthetic hairpin‐shaped oligodeoxyribonucleotide (ODN) containing the κB site with an integrated single diphosphoryldisulfide linkage, we demonstrate its covalent binding to the p50 subunit of NF‐κB. Furthermore, this decoy ODN induces apoptosis in a lymphoblastoma cell line. Thus, such chemically modified decoys could be valuable tools for blocking nuclear factors and tumor cell growth.
Receptor–drug association studies in the inhibition of the hematin aggregation process of malaria
Authors: Portela César , Afonso Carlos M.M. , Pinto Madalena M.M. , Ramos Maria João
Published: June 2003

Docking studies were performed to investigate the binding of several antimalarial compounds to the putative drug receptors involved in the hematin aggregation process. These studies reveal a binding profile that correlates with the complementarity of electrostatic potentials between the receptors and the active molecules. These results allow a possible explanation for the same molecular mechanism shown by 4‐aminoquinolines, quinine, mefloquine, halofantrine and hydroxylated xanthones. The docking data presented in this work offer an interesting approach to the design of new molecules with potential antimalarial activity.
MjK1, a K+ channel from M. jannaschii, mediates K+ uptake and K+ sensitivity in E. coli
Authors: Hellmer Jens , Zeilinger Carsten
Published: June 2003

The methanogenic and hyperthermophilic deep‐sea archaeon Methanococcus jannaschii has three putative K+ channels, MVP (Mj0139), MjK1 (Mj0138.1) and MjK2 (Mj1357). The physiological function of these K+ channels was examined in a viability assay, using the Escherichia coli mutant LB2003 (kup1, ΔkdpABC5, ΔtrkA). While MjK2 expression had no effects on the potassium‐dependent phenotype of LB2003, MVP and MjK1 complemented the deficiency at a concentration of 1 mM KCl. In contrast to KcsA, MthK and MVP, MjK1 strongly affected host cell viability at 10 and 100 mM KCl. The toxic effects were less pronounced when growth media were supplemented with the K+ channel blocker BaCl2.
Tropomodulin binds to filensin intermediate filaments
Authors: Fischer R.S. , Quinlan R.A. , Fowler V.M.
Published: June 2003

Tropomodulin (Tmod) is an actin filament pointed end capping protein found in the membrane skeleton of lens fiber cells. We demonstrate that Tmod4 is able to bind the lens‐specific intermediate filament protein, filensin, in either co‐sedimentation or solid phase binding assays in a saturable fashion, but with low affinity and stoichiometry. Furthermore, Tmod4 does not bind the 53 kDa rod domain of filensin, nor to CP49, the obligate assembly partner of filensin. Finally, the binding of filensin to Tmod4 does not inhibit the actin capping activity of Tmod4 in vitro, suggesting that the two functions are not mutually exclusive.
Identification of a novel Ezrin‐binding site in syndecan‐2 cytoplasmic domain
Authors: Granés Francesc , Berndt Christine , Roy Christian , Mangeat Paul , Reina Manuel , Vilaró Senén
Published: June 2003

ERM (Ezrin/Radixin/Moesin) proteins are crosslinkers between plasma membrane proteins and the actin cytoskeleton, thereby involved in the formation of cell adhesion sites. Earlier work showed that Ezrin links syndecan‐2 to the actin cytoskeleton. Here we provide evidence that the Ezrin N‐terminal domain binds to the syndecan‐2 cytoplasmic domain with an estimated K
D of 0.71 μM and without the requirement of other proteins. We also studied the regions in the syndecan‐2 cytoplasmic domain implicated in the binding to Ezrin. By truncating the syndecan‐2 cytoplasmic domain and by oligopeptide competition assays we show that the Ezrin‐binding sequence is not located in the positively charged juxtamembrane region (RMRKK), but in the neighboring sequence DEGSYD. We therefore conclude that the consensus sequence for Ezrin binding is unique among membrane proteins, suggesting a distinct regulation.
New perspectives on mitochondrial morphology in cell function
Authors: Brocard Jacques B. , Rintoul Gordon L. , Reynolds Ian J.
Published: June 2003

Mitochondria are a node of integration for intracellular signaling pathways and their morphology changes seem to be tightly associated with their function. New data show that morphology is one of the parameters involved in mitochondria's choice between promoting cell death and protecting cells against general metabolic jeopardy.
Existence of Lipschitzian solutions to the classical problem of the calculus of variations in the autonomous case
Authors: Cellina A. , Ferriero A.
Published: June 2003

Under general growth assumptions, that include some cases of linear growth, we prove existence of Lipschitzian solutions to the problem of minimizing

∫_a^b L(x(s),x'(s)) ds

with the boundary conditions

x(a)=A

,

x(b)=B

.

Dans l’article on démontre l’existence de solutions Lipschitziennes du problème de minimiser

∫_a^b L(x(s),x'(s)) ds

,

x(a)=A

,

x(b)=B

, avec des conditions faibles, de croissance, qui comprennent des cas de croissance linéaire.
Milton’s conjecture on the regularity of solutions to isotropic equations
Authors: Faraco Daniel
Published: June 2003

We present examples showing that the threshold for the integrability of the gradient of solutions to isotropic equations is

2K/(K−1)

. The main tools are

p

-laminates and Beltrami Operators.

Nous présentons des exemples, qui prouvent que le seuil de l’intégrabilité du gradient des solutions des équations isotropiques est

2K/(K−1)

. Les techniques principales sont les

p

-laminates et les opérateurs de Beltrami.
Nonhyperbolic persistent attractors near the Morse–Smale boundary
Authors: San Martı́n Rebolledo Bernardo , Vera Valenzuela Jaime A , Muñoz Morales Eduardo M
Published: June 2003

In this paper we present a submanifold

\mathcal {N}

of codimension two contained in the Morse–Smale regular boundary in

\mathcal X^r(M)

, the space of

\mathcal C^r

vector fields on a 3-dimensional manifold

M

, which exhibits singular cycles, such that for generic 2-parameter families going through, it has nonhyperbolic nontrivial attractors for a set of parameters with positive Lebesgue measure.

Dans cet article on construit une sous-variété

\mathcal {N}

de codimension deux contenue dans la frontière régulière de l’ensemble des champs de vecteurs Morse–Smale de

\mathcal X^r(M)

, l’espace de champs de vecteurs de classe

\mathcal C^r

sur la variété de dimension trois

M

, laquelle présente des cycles singuliers tels que, toute famille générique à deux paramètres transversale à

\mathcal {N}

possède des ensembles attractifs non hyperboliques et non triviaux pour un ensemble de paramètres dont la mesure de Lebesgue est positive.
Neumann and second boundary value problems for Hessian and Gauß curvature flows
Authors: Schnürer Oliver C , Smoczyk Knut
Published: June 2003

We consider the flow of a strictly convex hypersurface driven by the Gauß curvature. For the Neumann boundary value problem and for the second boundary value problem we show that such a flow exists for all times and converges eventually to a solution of the prescribed Gauß curvature equation. We also discuss oblique boundary value problems and flows for Hessian equations.

Nous considérons le flot d’une hypersurface strictement convexe piloté par la courbure de Gauß. Pour le problème aux limites de Neumann et pour le deuxième problème aux limites nous montrons qu’un tel flot existe pour tout temps et converge vers une solution de l’équation de courbure de Gauß prescrite. Nous étudions aussi des problèmes aux limites oblique et les flots pour des équations hessiennes.
Cryopreservation of tissue engineered constructs for bone
Authors: Kofron Michelle D. , Opsitnick Natalie C. , Attawia Mohamed A. , Laurencin Cato T.
Published: June 2003

The large‐scale clinical use of tissue engineered constructs will require provisions for its mass availability and accessibility. Therefore, it is imperative to understand the effects of low temperature (–196°C) on the tissue engineered biological system. Initial studies used samples of the osteoblast‐like cell line (SaOS‐2) adhered to a two‐dimensional poly(lactide‐co‐glycolide) thin film (2D‐PLAGA) or a three‐dimensional poly(lactide‐co‐glycolide) sintered microsphere matrix (3D‐PLAGA) designed for bone tissue engineering. Experimental samples were tested for their ability to maintain cell viability, following low temperature banking for one week, in solutions of the penetrating cryoprotective agents, dimethylsulfoxide (DMSO), ethylene glycol, and glycerol. Results indicated the DMSO solution yielded the greatest percent cell survival for SaOS‐2 cells adhered to both the 2D‐ and 3D‐PLAGA scaffolds; therefore, DMSO was used to cryopreserve mineralizing primary rabbit osteoblasts cells adhered to 2D‐PLAGA matrices for 35 days. Results indicated retention of the extracellular matrix architecture as no statistically significant difference in the pre‐ and post‐thaw mineralized structures was measured. Percent cell viability of the mineralized constructs following low temperature storage was approximately 50%. These are the first studies to address the issue of preservation techniques for tissue engineered constructs. The ability to successfully cryopreserve mineralized tissue engineered matrices for bone may offer an unlimited and readily available source of bone‐like materials for orthopaedic applications. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Electromyographic activity and strength during maximum isometric pronation and supination efforts in healthy adults
Authors: Gordon Karen D. , Pardo Richard D. , Johnson James A. , King Graham J. W. , Miller Thomas A.
Published: June 2003

There exists a lack of quantitative data in the literature related to the torque produced during axial forearm rotation and the electromyographic (EMG) activity of the muscles involved. Therefore, the purpose of this study was to compare the relative EMG activity of four forearm muscles during resisted forearm rotation. A custom‐built device capable of measuring torque in the absence of grip was employed. Fourteen healthy volunteers performed maximum isometric voluntary contractions in five positions of axial forearm rotation for both pronation and supination. EMG data were collected simultaneously from the supinator, biceps, pronator quadratus (deep and superficial heads), and pronator teres muscles using fine‐wire bipolar electrodes. Data were analyzed to determine the contributions of each muscle to pronation and supination torque over five positions of forearm rotation. In the absence of grip no significant difference was found between supination and pronation torque in neutral position. Supination torque generation was greater in the pronated forearm positions, and pronation torque was greater in the supinated positions (p < 0.05). A root‐mean‐square EMG analysis verified the major contributions of the pronator teres and both heads of the pronator quadratus muscle to pronation torque, and supinator and biceps to supination torque. The deep head of the pronator quadratus was active during both pronation and supination, lending support to the theory that it may act primarily as a dynamic distal radioulnar joint stabilizer. This information may be helpful in upper extremity modeling, surgical treatments, and rehabilitation strategies. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Erythromycin inhibits wear debris‐induced osteoclastogenesis by modulation of murine macrophage NF‐κB activity
Authors: Ren Weiping , Li Xiao Hua , Chen Ben D. , Wooley Paul H.
Published: June 2003

Activation of nuclear factor kappa B (NF‐κkB) signaling in response to cell stimulation by wear debris may be critical in the pathogenesis of aseptic loosening. Erythromycin (EM), a macrolide antibiotic, has been shown to effectively suppress some types of inflammatory reactions. In this study, we examined the effect of EM on wear debris‐induced osteoclastic bone resorption in vitro. EM inhibited Ca+ release from neonatal calvaria co‐cultured with conditioned medium from mouse RAW264.7 macrophages activated by wear debris. Inhibition of Ca+ release was associated with a decreased number of tartrate‐resistant acid phosphatase (TRAP)‐positive cells in cultured bones. To investigate the mechanism whereby EM inhibits bone‐resorption, RAW cells were incubated with wear debris in the presence EM. Real time RT‐CR analysis revealed that EM (5 μg/ml) significantly inhibited mRNA expression of NF‐κB, cathepsin K (CPK), IL‐1β and TNFα, but not RANK in RAW cells stimulated with wear debris. Furthermore, electrophoretic mobility‐shift assay showed that EM (0.2 μg‐5 μg/ml) could reduce DNA‐binding activity of NF‐κB in RAW cells stimulated with wear debris. The inhibition of inflammatory osteoclastogenesis by EM treatment was further confirmed by an osteoclast (OC) formation assay using primary cultures of mouse bone marrow progenitor cells stimulated with macrophage colony‐stimulating factor and RANK ligand (RANKL). EM treatment (5 μg/ml) resulted in more than 70% reduction in multinucleated OC formation and 50% reduction of TRAP+ cells by bone marrow progenitor cells. Our findings support that EM suppresses wear debris‐induced osteoclastic bone resorption by, at least, down‐regulation of NF‐κB signaling pathway. It appears that EM represents a potential therapeutic candidate for the treatment and prevention of aseptic loosening. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Pathology of lumbar nerve root compression Part 2: Morphological and immunohistochemical changes of dorsal root ganglion
Authors: Kobayashi Shigeru , Yoshizawa Hidezo , Yamada Shuuichi
Published: June 2003

Study design: This study is to investigate the changes of dorsal root ganglion (DRG) induced by mechanical compression using in vivo model.

Objectives: The effect of axonal flow disturbance induced by nerve root compression was determined in DRG.

Summary of background data: The dorsal root ganglion should not be overlooked when considering the mechanism of low back pain and sciatica, so it is important to understand the morphologic and functional changes that occur in primary sensory neurons of the dorsal root ganglion as a result of nerve root compression. However, few studies have looked at changes of neurons within the dorsal root ganglion caused by disturbance of axonal flow and the axon reaction as a result of mechanical compression of the dorsal root through which the central branches of the primary sensory nerves pass.

Methods: In mongrel dogs, the seventh lumbar nerve root was compressed for 24 h, one week, or three weeks using a clip with a pressure of 7.5 gf. Morphologic changes of the primary sensory neurons in the dorsal root ganglion secondary to the axon reaction were examined by light and electron microscopy. Changes of immunostaining for substance P (SP), calcitonin gene‐related peptide (CGRP), and somatostatin (SOM) in the primary sensory neurons affected by central chromatolysis after nerve root compression were also examined.

Results: Light microscopy showed central chromatolysis of neurons in the dorsal root ganglion from one week after the start of compression. Electron microscopy of the affected neurons revealed movement of the nucleus to the cell periphery and the loss of rough endo‐plasmic reticulum and mitochondria from the central region. Immunohistochemical studies showed a marked decrease of SP, CGRP, and SOM staining in small ganglion cells with central chromatolysis when compared with cells from control ganglia.

Conclusion: It is important to be aware that in patients with nerve root compression due to lumbar disc herniation or lumbar canal stenosis, dysfunction is not confined to degeneration at the site of compression, but also extends to the primary sensory neurons within the dorsal root ganglion as a result of the axon reaction. Patients with sensory disturbance should therefore be fully informed of the fact that these symptoms will not resolve immediately after surgery. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.