bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclic AMP affinity purification and ESI–QTOF MS–MS identification of cytosolic glyceraldehyde 3‐phosphate dehydrogenase and two nucleoside diphosphate kinase isoforms from tobacco BY‐2 cells
Authors: Laukens Kris , Roef Luc , Witters Erwin , Slegers Herman , Van Onckelen Harry
Published: October 2002

The soluble protein fraction of tobacco bright yellow 2 cells contained adenosine 3′,5′‐cyclic monophosphate (cAMP)‐binding activity, detected with both a conventional binding assay and a surface plasmon resonance biosensor. A cAMP‐agarose‐based affinity purification procedure yielded three proteins which were identified by mass spectrometry as glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) and two nucleoside diphosphate kinases (NDPKs). This is the first report describing an interaction between cAMP and these proteins in higher plants. Our findings are discussed in view of the reported role of the interaction of cAMP with GAPDH and NDPK in animals and yeast. In addition, we provide a rapid method to isolate both proteins from higher plants.
Identification of a functional destruction box in the Xenopus laevis aurora‐A kinase pEg2
Authors: Arlot-Bonnemains Yannick , Klotzbucher Andrea , Giet Régis , Uzbekov Rustem , Bihan Réjane , Prigent Claude
Published: October 2002

Like for all aurora‐A kinases, the Xenopus pEg2 kinase level peaks in G2/M and is hardly detectable in G1 cells, suggesting that the protein is degraded upon exit from mitosis as reported for the human aurora‐A kinase. We identified for the first time a sequence RxxL in the C‐terminal end of the kinase catalytic domain. Mutation of this sequence RxxL to RxxI suppresses the ubiquitination of the protein as well as its degradation. The sequence RxxL corresponding to the pEg2 functional destruction box has been conserved throughout evolution in all aurora kinases including aurora‐A, ‐B and ‐C.
Latent TGF‐β binding protein‐3 (LTBP‐3) requires binding to TGF‐β for secretion
Authors: Chen Yan , Dabovic Branka , Annes Justin P , Rifkin Daniel B
Published: October 2002

Latent transforming growth factor‐β (TGF‐β) binding protein (LTBP)‐1, which is easily secreted, has been shown to enhance the secretion of TGF‐β. Here we show that another member of the LTBP family, LTBP‐3, is not secreted by several cell types, but secretion occurs after coexpression with TGF‐β. The secretion of LTBP‐3 requires complexing of LTBP‐3 with Cys33 of the TGF‐β propeptide.
Implication of three isoforms of PLA2 in human T‐cell proliferation
Authors: Tessier Christian , Hichami Aziz , Akhtar Khan Naim
Published: October 2002

We observed that human (Jurkat) T‐cells constitutively expressed the mRNA, encoding for the four isoforms of phospholipase A2 (PLA2), i.e. two secretory (type IB and type V), and two cytosolic (type IV, Ca2+‐dependent and type VI, Ca2+‐independent). In order to assess whether these PLA2 isoforms are active, we labeled Jurkat T‐cells with [3H]arachidonic acid ([3H]AA) and determined its release into the extracellular medium in the presence of phorbol 12‐myristate 13‐acetate (PMA) and ionomycin. The three PLA2 isoforms seem functional as aristolochic acid and bromoenol lactone (BEL), the respective inhibitors of type IB/type V and type VI PLA2s, significantly inhibited the release of free [3H]AA. On the other hand, arachidonyl trifluoromethyl ketone (AACOCF3), an inhibitor of type IV PLA2, failed to curtail significantly the release of free [3H]AA into the extracellular medium. We assessed the implication of these PLA2 isoforms in transcription of the interleukin‐2 (IL‐2) gene, involved in T‐cell proliferation. Hence, aristolochic acid and BEL, but not AACOCF3, significantly inhibited the PMA and ionomycin‐induced induction of mRNA of IL‐2. Similarly, aristolochic acid and BEL, but not AACOCF3, significantly inhibited the PMA and ionomycin‐induced secretion of IL‐2 in the culture supernatants. Together these results suggest that human Jurkat T‐cells possess two secretory and two cytosolic PLA2 isoforms and only three of them (type IB, type V and type VI) are implicated in T‐cell proliferation.
Ascorbate inhibits iNOS expression in endotoxin‐ and IFNγ‐stimulated rat skeletal muscle endothelial cells
Authors: Wu Feng , Tyml Karel , Wilson John X.
Published: October 2002

Lipopolysaccharide endotoxin and interferon‐γ induced inducible nitric oxide synthase (iNOS) protein expression and nitrite/nitrate formation in microvascular endothelial cell cultures (ECs) derived from rat skeletal muscle. Pretreatment of ECs with ascorbate accumulated a large amount of ascorbate inside the cells and consequently decreased both intracellular oxidant level and iNOS induction. These effects of ascorbate were abolished in the presence of exogenous superoxide generated by xanthine oxidase/xanthine plus catalase but were not altered when N‐nitro‐L‐arginine methyl ester was applied to inhibit nitric oxide synthesis. Ascorbate also attenuated the activation of transcription factor IRF‐1 but not NFκB. These results indicate that ascorbate inhibits iNOS expression in ECs by an antioxidant mechanism independent of both NFκB activation and the reported negative feedback effect of nitric oxide.
Phospholipase C is required for glucose‐induced calcium influx in budding yeast
Authors: Tisi Renata , Baldassa Simona , Belotti Fiorella , Martegani Enzo
Published: October 2002

Intracellular calcium is a second messenger involved in several processes in yeast, such as mating, nutrient sensing, stress response and cell cycle events. It was reported that glucose addition stimulates a rapid increase in free calcium level in yeast. To investigate the calcium level variations induced by different stimuli we used a reporter system based on the photoprotein aequorin. Glucose addition (50 mM) to nutrient‐starved cells induced an increase in free intracellular calcium concentration, mainly due to an influx from external medium. The increase of calcium reached its maximum 100–120 s after the stimulus. A concentration of about 20 mM glucose was required for a 50% increase in intracellular calcium. This response was completely abolished in strain plc1Δ and in the isogenic wild‐type strain treated with 3‐nitrocoumarin, a phosphatidylinositol‐specific phospholipase C inhibitor, suggesting that Plc1p is essential for glucose‐induced calcium increase. This suggests that Plc1p should have a significant role in transducing glucose signal. The calcium influx induced by addition of high glucose on cells previously stimulated with low glucose levels was inhibited in strains with a deletion in the GPR1 or GPA2 genes, which suggests that glucose would be detected through the Gpr1p/Gpa2p receptor/G protein‐coupled (GPCR) complex. Moreover, the signal was completely abolished in a strain unable to phosphorylate glucose, which is consistent with the reported requirement of glucose phosphorylation for GPCR complex activation.
PPARγ ligands, troglitazone and pioglitazone, up‐regulate expression of HMG‐CoA synthase and HMG‐CoA reductase gene in THP‐1 macrophages
Authors: Iida Kaoruko Tada , Kawakami Yasushi , Suzuki Hiroaki , Sone Hirohito , Shimano Hitoshi , Toyoshima Hideo , Okuda Yukichi , Yamada Nobuhiro
Published: October 2002

Recently it has been reported that macrophages express a nuclear receptor, peroxisome proliferator‐activated receptor γ (PPARγ). Using a ligand of PPARγ, troglitazone or pioglitazone, we have shown that the expression of two genes involved in cholesterol biosynthesis, 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) synthase and HMG‐CoA reductase, were increased by activation of PPARγ through a PPAR response element (PPRE) in THP‐1 macrophages. In addition, treatment with troglitazone significantly increased the activity of HMG‐CoA reductase and the amount of intracellular cholesterol. Thus, we conclude that PPARγ and its agonists increase the cholesterol content of macrophages by the increased expression of genes involved in cholesterol biosynthesis. These findings suggest that PPARγ may play a role in cholesterol metabolism in macrophages.
Association of the mammalian proto‐oncoprotein Int‐6 with the three protein complexes eIF3, COP9 signalosome and 26S proteasome
Authors: Hoareau Alves Karine , Bochard Valérie , Réty Stéphane , Jalinot Pierre
Published: October 2002

The mammalian Int‐6 protein has been characterized as a subunit of the eIF3 translation initiation factor and also as a transforming protein when its C‐terminal part is deleted. It includes a protein domain, which also exists in various subunits of eIF3, of the 26S proteasome and of the COP9 signalosome (CSN). By performing a two‐hybrid screen with Int‐6 as bait, we have isolated subunits belonging to all three complexes, namely eIF3‐p110, Rpt4, CSN3 and CSN6. The results of transient expression experiments in COS7 cells confirmed the interaction of Int‐6 with Rpt4, CSN3 and CSN6, but also showed that Int‐6 is able to bind another subunit of the CSN: CSN7a. Immunoprecipitation experiments performed with the endogenous proteins showed that Int‐6 binds the entire CSN, but in low amount, and also that Int‐6 is associated with the 26S proteasome. Taken together these results show that the Int‐6 protein can bind the three complexes with various efficiencies, possibly exerting a regulatory activity in both protein translation and degradation.
The physiological role of dehydroascorbic acid
Authors: Wilson John X
Published: October 2002

Dehydroascorbic acid (DHA) is abundant in the human diet and also is generated from vitamin C (ascorbic acid, AA) in the lumen of the gastrointestinal tract. DHA is absorbed from the lumen of the small intestine and reduced to AA, which subsequently circulates in the blood. Utilization of AA as an antioxidant and enzyme cofactor causes its oxidation to DHA in extracellular fluid and cells. DHA has an important role in many cell types because it can be used to regenerate AA. Both physiological (e.g. insulin, insulin‐like growth factor I, cyclic AMP) and pathological (e.g. oxidative stress, diabetes, sepsis) factors alter the transport and metabolic mechanisms responsible for this DHA recycling.
Maltooligosaccharide disproportionation reaction: an intrinsic property of amylosucrase from Neisseria polysaccharea
Authors: Albenne Cécile , Skov Lars K , Mirza Osman , Gajhede Michael , Potocki-Véronèse Gabrielle , Monsan Pierre , Remaud-Simeon Magali
Published: October 2002

Amylosucrase from Neisseria polysaccharea (AS) is a remarkable transglycosidase of family 13 of the glycoside hydrolases that catalyses the synthesis of an amylose‐like polymer from sucrose and is always described as a sucrose‐specific enzyme. Here, we demonstrate for the first time the ability of pure AS to catalyse the disproportionation of maltooligosaccharides by cleaving the α‐1,4 linkage at the non‐reducing end of a maltooligosaccharide donor and transferring the glucosyl unit to the non‐reducing end of another maltooligosaccharide acceptor. Surprisingly, maltose, maltotriose and maltotetraose are very poor glucosyl donors whereas longer maltooligosaccharides are even more efficient glucosyl donors than sucrose. At least five glucose units are required for efficient transglucosylation, suggesting the existence of strong binding subsites, far from the sucrose binding site, at position +4 and above.
Orientation and interactions of dipolar molecules during transport through OmpF porin
Authors: Robertson Kindal M , Tieleman D.Peter
Published: October 2002

The outer membrane of Gram‐negative bacteria contains porins, large sieve‐like proteins allowing small molecules to diffuse in and out of the periplasm. We have simulated transport of the dipolar molecules alanine and methylglucose through the OmpF porin from Escherichia coli using non‐equilibrium steered molecular dynamics simulations in a realistic bilayer environment. Structural perturbation of the protein is minimal. During the permeation process, both alanine and methylglucose align strongly in the electric field in the eyelet region, where the adhesion force on the permeating molecule has a maximum. Binding of the permeating dipolar molecules in the eyelet region is not observed.
CIN85/CMS family of adaptor molecules
Authors: Dikic Ivan
Published: October 2002

CIN85 and CMS belong to a family of ubiquitously expressed adaptor molecules containing three SH3 domains, a proline‐rich region and a coiled‐coil domain. By binding to numerous proteins they assemble multimeric complexes implicated in cell‐specific signals controlling T‐cell activation, kidney glomeruli function or apoptosis in neuronal cells. CIN85/CMS also associate with accessory endocytic proteins, components of the actin cytoskeleton as well as other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. These interactions enable CIN85/CMS to function within a network of signaling pathways that co‐ordinate critical steps involved in downregulation and degradation of RTKs.
Differential effect of pH on sodium binding by the various GABA transporters expressed in Xenopus oocytes
Authors: Grossman Tamar R , Nelson Nathan
Published: October 2002

Mouse GABA transporters belong to the family of Na+‐ and Cl−‐dependent neurotransmitter transporters. The four GABA transporters exhibit unique presteady‐state currents when expressed in Xenopus oocytes. The properties of the presteady‐state currents correspond to their different affinities to Na+. In the presence of 20 μM GABA and at pH 7.5, the half‐maximal uptake activity was 47, 120, 25 and 35 mM Na+ for GAT1, GAT2, GAT3 and GAT4, respectively. The appearance of presteady‐state currents at positive or negative imposed potentials was in correlation with the affinity to Na+. Changing the external pH differentially affected the GABA uptake and the presteady‐state activities of the various GABA transporters. It is suggested that protons compete with Na+ on its binding site; however, the proton binding is not productive and is unable to drive GABA uptake.
N‐acetylcysteine prevents MAA induced male germ cell apoptosis: role of glutathione and cytochrome c
Authors: Rao A.V.S.Kondala , Shaha Chandrima
Published: October 2002

Exposure to methoxyacetic acid (MAA), a major byproduct of the paint industry, causes testicular atrophy in multiple species. This study demonstrates DNA breakdown in rat germ cells after exposure to MAA in vivo within 12 h, leading to 40% germ cell death by 24 h. Within 4 h of treatment, cytochrome c is released from the mitochondria into the cytosol without the involvement of mitochondrial potential loss, reactive oxygen species generation or lipid peroxidation events. Peak activation of caspase‐9 and caspase‐3 is detectable post treatment at 4 and 8 h respectively. There is a decrease in germ cell glutathione levels within 2 h of MAA treatment. Replenishment of glutathione by pretreatment of the animals with the antioxidant N‐acetylcysteine prior to MAA treatment could prevent the release of cytochrome c, DNA fragmentation and cell death.
Novel strategy for anti‐HIV‐1 action: selective cytotoxic effect of N‐myristoyltransferase inhibitor on HIV‐1‐infected cells
Authors: Takamune Nobutoki , Hamada Hirotoshi , Misumi Shogo , Shoji Shozo
Published: October 2002

N‐myristoyltransferase (NMT) is essential for the survival of eukaryotes and the production of infectious human immunodeficiency virus type‐1(HIV‐1) by the host cell. In this study, we found decreases in the mRNA levels of human NMT isoforms and the NMT activities in the course of HIV‐1 infection in the human T‐cell line, CEM. Investigating the cytotoxic effect of the novel synthetic NMT inhibitors on the chronic HIV‐1 infected T‐cell line, CEM/LAV‐1, and the uninfected CEM, revealed that the cytotoxic effect was significantly selective for CEM/LAV‐1. This was thought to be due to the difference between the NMT levels of the cell lines. In this paper, we propose that NMT may be a candidate target for anti‐HIV‐1‐infected‐cell agents.
SecY–SecY and SecY–SecG contacts revealed by site‐specific crosslinking
Authors: van der Sluis Eli O , Nouwen Nico , Driessen Arnold J.M
Published: October 2002

Protein translocation across the cytoplasmic membrane of Escherichia coli is mediated by the integral membrane complex SecYEG and the peripherally bound ATPase SecA. To probe the environment of the cytoplasmic domains of SecY within the SecYEG complex, we introduced single cysteine residues in each of the six cytoplasmic domains. Neighbouring SecY molecules with a single cysteine residue in cytoplasmic domains C1, C2 or C6 formed a disulfide bond upon oxidation. The presence of the disulfide bond between two C2 domains reversibly inhibited protein translocation. Chemical crosslinking showed that the C2 and C3 domains are in close proximity of SecG and chemical modification of the cysteine residue in the C5 domain with N‐ethyl‐maleimide or fluorescein‐5‐maleimide inactivates the SecYEG complex. Taken together, our data give novel insights in the interactions between subunits of the SecYEG complex and emphasise the importance of cytoplasmic domain C5 for SecY functioning.
Comparative characterization of Aedes 3‐hydroxykynurenine transaminase/alanine glyoxylate transaminase and Drosophila serine pyruvate aminotransferase
Authors: Han Qian , Li Jianyong
Published: October 2002

This study describes the comparative analysis of two insect recombinant aminotransferases, Aedes aegypti 3‐hydroxykynurenine (3‐HK) transaminase/alanine glyoxylate aminotransferase (Ae‐HKT/AGT) and Drosophila melanogaster serine pyruvate aminotransferase (Dm‐Spat), which share 52% identity in their amino acid sequences. Both enzymes showed AGT activity. In addition, Ae‐HKT/AGT is also able to catalyze the transamination of 3‐HK or kynurenine with glyoxylate, pyruvate or oxaloacetate as the amino acceptor. Kinetic analysis and other data suggest that Ae‐HKT/AGT plays a critical role in mosquito tryptophan catabolism by detoxifying 3‐HK and that Dm‐Spat is primarily involved in glyoxylate detoxification.
Posttranslational modification of E. coli histone‐like protein H‐NS and bovine histones by short‐chain poly‐(R)‐3‐hydroxybutyrate (cPHB)
Authors: Reusch Rosetta N. , Shabalin Olga , Crumbaugh A. , Wagner Rolf , Schröder Oliver , Wurm Reinhild
Published: October 2002

Short‐chain poly‐(R)‐3‐hydroxybutyrate (cPHB), a highly flexible, amphiphilic molecule with salt‐solvating properties, is a ubiquitous constituent of prokaryotic and eukaryotic cells, wherein it is mainly conjugated to proteins. The solvating properties and cellular distribution of cPHB suggest it may be associated with proteins that bind and/or transfer DNA. Here we examine Escherichia coli protein H‐NS and calf thymus histones, H1, H2A, H2B, H3, and H4, for the presence of cPHB. The proteins are related in that all bind to DNA and are implicated in the compact organization of the chromosome. The presence of cPHB in E. coli H‐NS was first detected in Western blots of two‐dimensional sodium dodecyl sulfate–polyacrylamide gel electrophoresis gels of total cell proteins, probed with anti‐cPHB IgG, and then by Western blot analysis of the purified protein. Western blot analysis of the calf thymus histones indicated that each contained cPHB. The presence of cPHB in H‐NS and histones was confirmed by chemical assay. The in vivo size of conjugated cPHB could not be established due to the lack of standards and degradation of cPHB during protein purification and storage. The molecular characteristics of cPHB and its presence in histone‐like and histone proteins of diverse organisms suggest it may play a role in DNA binding and/or DNA organization.
Identification of a pH regulated Na+/H+ antiporter of Methanococcus jannaschii
Authors: Hellmer Jens , Pätzold Ralf , Zeilinger Carsten
Published: October 2002

The genome of the hyperthermophilic archaeon Methanococcus jannaschii contains three Na+/H+ antiporter related genes Mj0057, Mj1521 and Mj1275. Comparative sequence alignments revealed that Mj0057 and Mj1521 belong to the NhaP family whereas Mj1275 is a member of the NapA family. The genes were cloned and expressed in the double mutant Escherichia coli strain Frag144 (ΔnhaA, ΔnhaB) to analyze their capability of mediating ΔpH driven Na+ flux in everted vesicles. From the tested clones only Mj0057 displayed Na+ (Li+)/H+ antiporter activity. The transport was pH dependent and occurred at pH 7.0 and below. At pH 6.0 the apparent K
m values for Na+ and Li+ were approximately 10 and 2.5 mM, respectively.
FGF receptors ubiquitylation: dependence on tyrosine kinase activity and role in downregulation
Authors: Monsonego-Ornan E , Adar R , Rom E , Yayon A
Published: October 2002

A crucial aspect of ligand‐mediated receptor activation and shut‐down is receptor internalization and degradation. Here we compared the ubiquitylation of either wild type or a K508A ‘kinase‐dead’ mutant of fibroblast growth factor receptor 3 (FGFR3) with that of its naturally occurring overactive mutants, G380R as in achondroplasia, or K650E involved in thanatophoric dysplasia. Fibroblast growth factor receptors ubiquitylation was found to be directly proportional to their intrinsic tyrosine kinase activity, both of which could be blocked using kinase inhibitors. Despite excessive ubiquitylation, both overactive mutants failed to be efficiently degraded, even when challenged with ligand or overexpression of c‐Cbl, a putative E3 ligase. We conclude that phosphorylation is essential for FGFR3 ubiquitylation, but is not sufficient to induce downregulation of its internalization resistant mutants.
Apisimin, a new serine–valine‐rich peptide from honeybee (Apis mellifera L.) royal jelly: purification and molecular characterization1
Authors: Bı́liková K , Hanes J , Nordhoff E , Saenger W , Klaudiny J , Šimúth J
Published: October 2002

A peptide named apisimin was found in honeybee (Apis mellifera L.) royal jelly (RJ). N‐terminal sequencing showed that this peptide corresponded to the sequence of a cDNA clone isolated from an expression cDNA library prepared from heads of nurse honeybees. No homology was found between the protein sequence of apisimin with a molecular mass of 5540.4 Da and sequences deposited in the Swiss‐Prot database. The 54 amino acids of apisimin do not include Cys, Met, Pro, Arg, His, Tyr, and Trp residues. The peptide shows a well‐defined secondary structure as observed by CD spectroscopy, and has the tendency to form oligomers. Isoelectrofocusing showed apisimin to be an acidic peptide.
β‐Aspartylpeptides as substrates of L‐asparaginases from Escherichia coli and Erwinia chrysanthemi
Authors: Kelo Eira , Noronkoski Tiina , Stoineva Ivanka B , Petkov Dimiter D , Mononen Ilkka
Published: October 2002

L‐Asparaginase is known to catalyze the hydrolysis of L‐asparagine to L‐aspartic and ammonia, but little is known about its action on peptides. When we incubated L‐asparaginases purified either from Escherichia coli or Erwinia chrysanthemi – commonly used as chemotherapeutic agents because of their antitumour activity – with eight small β‐aspartylpeptides such as β‐aspartylserineamide, β‐aspartylalanineamide, β‐aspartylglycineamide and β‐aspartylglycine, we found that both L‐asparaginases could catalyze the hydrolysis of five of them yielding L‐aspartic acid and amino acids or peptides. Our data show that L‐asparaginases can hydrolyze β‐aspartylpeptides and suggest that L‐asparaginase therapy may affect the metabolism of β‐aspartylpeptides present in human body.
Cellular munc18c levels can modulate glucose transport rate and GLUT4 translocation in 3T3L1 cells
Authors: Macaulay S.Lance , Grusovin Julian , Stoichevska Violet , Ryan Joanne M , Castelli Laura A , Ward Colin W
Published: October 2002

Munc18c has been shown to bind syntaxin 4 and to play a role in GLUT4 translocation and glucose transport, although this role is as yet poorly defined. In the present study, the effects of modulating the available level of munc18c on glucose transport and GLUT4 translocation were examined. Over‐expression of munc18c in 3T3L1 adipocytes inhibited insulin‐stimulated glucose transport by approximately 50%. Basal glucose transport rates were also decreased by approximately 25%. In contrast, microinjection of a munc18c polyclonal antibody stimulated GLUT4 translocation by approximately 60% over basal levels without affecting insulin‐stimulated GLUT4 levels. Microinjection of a control antibody had no effect. These data are consistent with the likelihood that antibody microinjection sequesters munc18c enabling translocation/fusion of GLUT4 vesicles. Mutagenesis of a potential proline‐directed kinase phosphorylation site in munc18c, T569, that in previous studies of its neuronal counterpart munc18a caused its dissociation from its complex with syntaxin 1a, had no effect on munc18c's association with syntaxin 4 or its inhibition of glucose transport, indicative that phosphorylation of this residue is not important for insulin regulation of glucose transport. The over‐expression and microinjection sequestration data support an inhibitory role for munc18c on translocation/fusion of GLUT4 vesicles. They further show that altering the level of available munc18c in 3T3L1 cells can modulate glucose transport rates, indicating its potential as a target for therapeutics in diabetes.
Glucocorticoid inhibits expression of V‐1, a catecholamine biosynthesis regulatory protein, in cultured adrenal medullary cells
Authors: Hiwatashi Yusuke , Kurahashi Yusuke , Hatada Risa , Ueno Susumu , Honma Takao , Yanagihara Nobuyuki , Yanase Haruko , Iwanaga Toshihiko , Ohizumi Yasushi , Yamakuni Tohru
Published: October 2002

V‐1 acts as a positive and coordinate regulator of gene expression of catecholamine biosynthetic enzymes in PC12D cells. The present study was conducted to investigate the mechanism controlling expression of V‐1 in the adrenal gland. Immunohistochemical analysis demonstrated that noradrenergic chromaffin cells more highly expressed V‐1 than adrenergic chromaffin cells preferentially expressing the glucocorticoid receptor in rat adrenal glands. Western blotting showed that in cultured bovine adrenal medullary cells, dexamethasone, a synthetic glucocorticoid, inhibited expression of V‐1, and that this inhibition was prevented by RU‐486, a glucocorticoid receptor antagonist. These results suggest that adrenal expression of V‐1 is differentially controlled by glucocorticoids through the specific receptor, and that thereby V‐1 regulates catecholamine biosynthesis in a catecholaminergic phenotype‐dependent manner.
Modulation of Kv4.3 current by accessory subunits
Authors: Deschênes Isabelle , Tomaselli Gordon F
Published: October 2002

Kv4.3 encodes the pore‐forming subunit of the cardiac transient outward potassium current (I
to). hKv4.3‐encoded current does not fully replicate cardiac I
to, suggesting a functionally significant role for accessory subunits. KChIP2 associates with Kv4.3 and modifies hKv4.3‐encoded currents but does not replicate native I
to. We examined the effect of several ancillary subunits expressed in the heart on hKv4.3‐encoded currents. Remarkably, the ancillary subunits Kvβ3, minK, MiRP‐1, the Na channel β1 and KChIP2 increased the density and modified the gating of hKv4.3 current. hKv4.3 promiscuously assembles with ancillary subunits in vitro, functionally modifying the encoded currents; however, the physiological significance is uncertain.
Allosteric transitions of Torpedo acetylcholine receptor in lipids, detergent and amphipols: molecular interactions vs. physical constraints
Authors: Martinez Karen L , Gohon Yann , Corringer Pierre-Jean , Tribet Christophe , Mérola Fabienne , Changeux Jean-Pierre , Popot Jean-Luc
Published: October 2002

The binding of a fluorescent agonist to the acetycholine receptor from Torpedo electric organ has been studied by time‐resolved spectroscopy in three different environments: in native membrane fragments, in the detergent CHAPS, and after complexation by amphipathic polymers (‘amphipols’). Binding kinetics was similar in the membrane and in amphipols, demonstrating that the receptor can display unaltered allosteric transitions outside its natural lipid environment. In contrast, allosteric equilibria were strongly shifted towards the desensitized state in CHAPS. Therefore, the effect of CHAPS likely results from molecular interactions rather than from the loss of bulk physical properties of the membrane environment.
Demonstration of glycosaminoglycans in Caenorhabditis elegans
Authors: Yamada Shuhei , Van Die Irma , Van den Eijnden Dirk H. , Yokota Akiko , Kitagawa Hiroshi , Sugahara Kazuyuki
Published: October 2002

A considerable amount (approximately 1.6 μg from 1 mg of dried nematode) of non‐sulfated chondroitin, two orders of magnitude less yet an appreciable amount of heparan sulfate, and no hyaluronate were found in Caenorhabditis elegans nematodes. The chondroitin chains were heterogeneous in size, being shorter than that of whale cartilage chondroitin sulfate. The disaccharide composition analysis of heparan sulfate revealed diverse sulfation including glucosamine 2‐N‐sulfation, glucosamine 6‐O‐sulfation and uronate 2‐O‐sulfation. These results imply that chondroitin and heparan sulfate are involved in fundamental biological processes.
The yeast Rgd1p is a GTPase activating protein of the Rho3 and Rho4 proteins
Authors: Doignon François , Weinachter Caroline , Roumanie Olivier , Crouzet Marc
Published: October 2002

The RGD1 gene, identified during sequencing of the Saccharomyces cerevisiae genome, encodes a protein with a Rho‐GTPase activating protein (GAP) domain at the carboxy‐terminal end. The Rgd1 protein showed two‐hybrid interactions with the activated forms of Rho2p, Rho3p and Rho4p. Using in vitro assays, we demonstrated that Rgd1p stimulated the GTPase activity of both Rho3p and Rho4p; no stimulation was observed on Rho2p. In addition, the rho3Δrgd1Δ double mutant exhibited a dramatic growth defect compared to the single mutants, suggesting that Rgd1p has a GAP activity in vivo. The present study allowed the identification of the first GAP of Rho3p and Rho4p.
Cyclooxygenase‐2 activity is necessary for the angiogenic properties of oncostatin M
Authors: Pourtau Jérôme , Mirshahi Farrokh , Li Hong , Muraine Marc , Vincent Loïc , Tedgui Alain , Vannier Jean-Pierre , Soria Jeannette , Vasse Marc , Soria Claudine
Published: October 2002

Macrophages play a major role in angiogenesis. We recently reported that oncostatin M (OSM), a cytokine of the interleukin (IL)‐6 family secreted by macrophages, has a potent angiogenic activity on human microvascular endothelial cells (HMEC‐1), but has no effect on macrovascular cells (human umbilical vein endothelial cells (HUVECs)). In this work, we show that in HMEC‐1, OSM (0.5–2.5 ng/ml), leukemia inhibitory factor (LIF) (25 ng/ml), bFGF (25 ng/ml) and IL‐1β (5 ng/ml) induced production of cyclooxygenase (COX)‐2. In contrast, in HUVECs, neither OSM nor LIF induced COX‐2 mRNA, suggesting that COX‐2 might be implicated in the angiogenic activity of OSM. This was confirmed by the inhibiting effect on OSM‐induced HMEC‐1 proliferation of specific COX‐2 inhibitors. In vivo studies confirmed this findings. We conclude that induction of COX‐2 by OSM is necessary for its angiogenic activity, but is not sufficient since IL‐1β, which also induces COX‐2 in HMEC‐1, has only a poor proliferative effect.
The use of electronic data interchange for supply chain coordination in the food industry
Authors: Hill Craig A. , Scudder Gary D.
Published: October 2002

Supply chain management (SCM) is concerned with the relationship between a company and its suppliers and customers. It is characterized by interorganizational coordination: companies working jointly with their customers and suppliers to integrate activities along the supply chain to effectively supply product to customers. More developed SCM is indicated by systematic integration, i.e. standardized and automatic interorganizational interfaces. Information technology (IT) engenders such systematic integration by allowing more efficient and automatic information flow.

This research focuses on electronic data interchange (EDI), an important class of IT used for interorganizational information transfers in the supply chain. Data from a survey of the food industry is used to examine the use of EDI with respect to interfirm coordination activities involving suppliers and customers. The influence of demographic characteristics on EDI use is also investigated. The results suggest that firms view EDI as a tool for improving efficiencies rather than as a tool for facilitating supply chain integration. There is also a surprising difference in firms use of EDI with customers vis‐à‐vis suppliers. Firms tend to be much more accommodating of the desires of their customers than of their suppliers.
The determinants of firm performance after ownership transformation in Slovenia
Authors: Hrovatin N. , Uršič S.
Published: October 2002

In the last decade there has been an extensive debate in transition countries on whether ownership matters for company performance. The key issue has been whether outsider ownership outperforms insider ownership. This paper examines the influence of several variables — insider ownership, ownership by the state and municipalities, market share and the share of exports — on company performance in a sample of 488 Slovenian industrial companies after their ownership transformation. Econometric estimations demonstrate, contrary to the expectations based on previous Slovenian studies, that insider ownership does enhance performance. Market share has the expected positive influence on value added, whereas the influence of exports is negative due to the export reorientation to Western markets and the exchange rate policy in 1998. The effect of state ownership is statistically insignificant.
Fetal Heart Rate Monitoring: Interpretation and Collaborative Management
Authors: Fox Michael , Kilpatrick Sarah , King Tekoa , Parer Julian T.
Published: October 2002

Effective intrapartum fetal heart rate (FHR) monitoring requires ongoing collaboration among health care providers. Nurses, midwives, and physicians must have a shared understanding of 1) how FHR tracings are interpreted, 2) which FHR patterns are associated with actual or impending fetal acidemia, 3) when and within what time frame the physician or the midwife should be notified of variant FHR patterns, 4) how quickly physicians and midwives should respond when notified of variant patterns, and 5) the indications for and optimal timing of interventions such as operative delivery. This article reviews the literature on FHR monitoring and includes a discussion of the advantages and limitations of different monitoring modalities. An overview of those FHR patterns are associated with presumed fetal acidemia is presented, as well as sample multidisciplinary FHR monitoring guidelines and an exercise in intrapartum FHR pattern evaluation that can be used to initiate development of local FHR monitoring patterns.
Scope of Practice: Freedom Within Limits
Authors: Schuiling Kerri D. , Slager Joani
Published: October 2002

“Scope of practice” has a variety of meanings amongst mid‐wives, other health professionals, health organizations, and consumers of midwifery care. For some, it refers to the Standards for the Practice of Midwifery; for others, it encompasses the legal base of practice; still others equate it with the components of the clinical parameters of practice. Because “scope of practice” is dynamic and parameters of practice can be impacted by many variables, succinctly defining “scope of practice” is difficult.

This article provides a comprehensive discussion of the concept “scope of practice.” Clinical scenarios are provided as case exemplars. The aim of this paper is to provide both new and experienced midwives with a substantive definition of the concept “scope of practice.”
THE EVOLUTION OF THE CORE COMPETENCIES FOR BASIC MIDWIFERY PRACTICE
Authors: Burst Helen Varney , Avery Melissa D.
Published: October 2002

The Core Competencies for Basic Midwifery Practice, as promulgated by the American College of Nurse‐Midwives (ACNM), was first published in 1978 to provide a standard approach to nurse‐midwifery education. Since then, it has been revised three times, most recently in 1997, and now serve as the curricular template for ACNM‐accredited education programs. This paper discusses the historic evolution of the core competencies and the document's use in midwifery education and practice.
Layering and orientational ordering of propane on graphite: An experimental and simulation study
Authors: Zhao Xiongce , Kwon Seokjoon , Vidic Radisav D. , Borguet Eric , Johnson J. Karl
Published: October 2002

We report the results of an experimental and theoretical study of propane adsorption on highly oriented pyrolytic graphite. Simulations and experiments were carried out for temperatures from 90 to 110 K and pressures from ultrahigh vacuum up to about 0.5 mTorr. Both simulations and experiments show that propane adsorbs in a layer-by-layer fashion and exhibits continuous growth beyond the second layer at the higher temperatures studied. Experimental adsorption data were obtained by optical differential reflectance (ODR) and temperature programmed desorption (TPD). The ODR method is able to dynamically follow the adsorption and desorption process as a function of time over a wide pressures range, while TPD probes only the desorption events at ultrahigh vacuum conditions. The influence of the fluid–fluid potential on the adsorption isotherms has been investigated by comparing simulations using five different propane potentials. The pressure at which the second layer forms was found to vary by more than 1 order of magnitude among the potentials tested, whereas the isosteric heat of adsorption is less sensitive to the potential. We find that the propane potential that best describes the liquid phase energetics is in the best agreement with experimental adsorption isotherms and isosteric heats. The binding energy of propane in the monolayer measured from TPD experiments is in excellent agreement with that computed from simulations, both giving values of about 30 kJ mol−1. The isosteric heat of adsorption at incipient second layer formation is 23±2 kJ mol−1 as measured from ODR isotherms and 24±1 kJ mol−1 computed from simulations. The isosteric heat as a function of coverage computed from molecular simulations is roughly constant over the 1–2 and the 2–3 layering transitions at 91 K. We show that this unusual behavior is due to a rotational transition, whereby molecules in the first layer rotate from a parallel (all CHx groups in contact with the graphite plane) to a perpendicular (one CH3 group pointing up) orientation. This rotational transition has two effects: it allows more molecules to adsorb in the monolayer and increases the isosteric heat of adsorption in the second layer over that for adsorption onto an atomically smooth surface.
Relativistic Gaussian basis sets for molecular calculations: Cs–Hg
Authors: Koga Toshikatsu , Tatewaki Hiroshi , Matsuoka Osamu
Published: October 2002

Relativistic Gaussian basis sets suitable for molecular calculations are presented for the 26 atoms Cs55 through Hg80. This is the second part of our systematic generation of the basis sets, proposed in a previous paper [J. Chem. Phys. 115, 3561 (2001)]. For the 26 atoms, the maximum truncation error in the total energies is 4.97 mhartree and the virial deviations from −1 never exceed 1.2×10−7. A test calculation on the GdF molecule is given.
Pressure and temperature dependence of the melt segmental dynamics of cis-1,4-polyisoprene via time resolved optical spectroscopy
Authors: Punchard B. J. , Adolf D. B.
Published: October 2002

The local segmental dynamics of melt anthracene-labeled cis-1,4-polyisoprene have been studied as a function of temperature (318–333 K) and pressure (0.1–140 MPa). Activation volumes for the motions range from 24 to 39 cm3 mol−1 and are observed to be temperature dependent, decreasing with increasing temperature. Activation energies at constant pressure range from 32 to 75 kJ mol−1 and are significantly pressure dependent, increasing with increasing pressure. These activation energies are decomposed at a series of pressures and temperatures into a term arising from the energy required to execute the motions at constant volume (i.e., a constant volume activation energy) and a term describing the energy required to create the needed free volume for the observed motions. Values of the constant volume activation energy for the local motions are compared where nearly the same density is reached either via the combination of a high pressure and high temperature or the combination of a lower pressure and lower temperature. These comparisons reveal that the constant volume activation energy reached via the higher pressure and temperature is larger.
Anomalous localization effects associated with excess volume of cobalt catalyst in multiwalled carbon nanotubes
Authors: Haruyama Junji , Takesue Izumi , Hasegawa Tetsuro
Published: October 2002

We report on the anomalous localization effects strongly associated with excess volume of a cobalt catalyst in multiwalled carbon nanotubes (MWNTs) synthesized in nanoporous alumina membranes. These effects bring about the following anomalies in bulk MWNTs: (a) A slight increase in the volume of excess cobalt changes antilocalization (AL) to weak localization (WL), (b) a further increase in excess changes this WL back to the AL, but only in magnetoresistance (MR) oscillation, and (c) even under this AL in MR, AL can not be observed in the conductance versus logarithmic temperature relation. Mechanisms for these anomalies were discussed based on the unique MWNT structures.
Transient optical studies of charge recombination dynamics in a polymer/fullerene composite at room temperature
Authors: Montanari Ivan , Nogueira Ana F. , Nelson Jenny , Durrant James R. , Winder Christoph , Loi Maria Antonietta , Sariciftci Niyazi Serdar , Brabec Christoph
Published: October 2002

The recombination kinetics of photogenerated charge carriers in a composite of poly[2-methoxy-5- (3′,7′-dimethyloctyloxy)-1-4-phenylene vinylene], (MDMO–PPV) and the functionalised fullerene 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 are investigated at room temperature by transient absorption spectroscopy. The decay dynamics of positively charged MDMO–PPV polarons were found to be either monophasic or biphasic, depending upon the laser excitation density employed. The slower, power law, decay phase (100 ns–10 ms) is attributed to recombination dynamics of localized polarons, while the fast decay component (<20 ns) is attributed to recombination of relatively mobile polarons observed when the density of localized states is exceeded by the density of photogenerated polarons (∼1017 cm−3). The implications of these observations are discussed in relation to polymer/C60 photovoltaic cells.
Impact of the channel thickness on the performance of Schottky barrier metal–oxide–semiconductor field-effect transistors
Authors: Knoch J. , Appenzeller J.
Published: October 2002

We present quantum simulations of single-gated Schottky barrier metal–oxide–semiconductor field-effect transistors on ultrathin silicon on insulator. The electrostatics of such devices is investigated and the influence of the silicon thickness on the Schottky barriers at the source and drain and, thus, the influence on the current–voltage characteristics are elaborated. We show that decreasing the channel layer thickness leads to a strong reduction of the Schottky barrier thickness and thus to an increased gate control of the drain current. The use of ultrathin channel layers improves the off- as well as the on state of such transistors and results in electrical characteristics comparable with conventional metal–oxide–semiconductor field-effect transistors.
Depth profiling InGaN/GaN multiple quantum wells by Rutherford backscattering: The role of intermixing
Authors: Pereira S. , Pereira E. , Alves E. , Barradas N. P. , O’Donnell K. P. , Liu C. , Deatcher C. J. , Watson I. M.
Published: October 2002

We report a detailed compositional analysis of InxGa1−xN/GaN multiple quantum wells (MQWs) grown by metalorganic chemical vapor deposition. Depth profiles of the InN fraction, x, in the MQWs were determined from grazing incidence Rutherford backscattering spectroscopy (RBS) analysis. Simulation of the RBS spectra provides precise estimations of individual well compositions, thickness, and the extent of In/Ga intermixing. It is ascertained that intermixing, and In segregation to the GaN cap layer, strongly increase with the value of x in the wells and with the number of periods in the MQW stack. Deleterious effects of intermixing on the spectral properties are apparent when comparing the photoluminescence spectra of two MQW structures with 8 and 18 wells, grown under the same nominal conditions.
Efficient diode-pumped passively Q-switched laser operation around 1.9 μm and self-frequency Raman conversion of Tm-doped KY(WO4)2
Authors: Batay L. E. , Kuzmin A. N. , Grabtchikov A. S. , Lisinetskii V. A. , Orlovich V. A. , Demidovich A. A. , Titov A. N. , Badikov V. V. , Sheina S. G. , Panyutin V. L. , Mond M. , Kück S.
Published: October 2002

Passively Q-switched operation of Yb,Tm:KY(WO4)2 and Tm:KY(WO4)2 lasers diode pumped at 805 nm has been investigated. A thin plate of Cr:ZnS was used as a saturable absorber for passive Q switching. A maximum average output power of 116 mW emitted at 1.9 μm in comparison to 160 mW for the free-running regime at the same pumping level has been obtained with a slope efficiency of 26% with respect to the incident pump power. Using a Tm:KYW sample with broadband antireflection coatings and dichroic laser resonator mirror, the first Stokes component of Raman self-frequency conversion was observed at 2365 nm.
Wavelength- and duration-tunable soliton source based on a 20-GHz Mach–Zehnder modulator and adiabatic Raman compression
Authors: de Matos C. J. S. , Chestnut D. A. , Taylor J. R.
Published: October 2002

Adiabatic Raman compression was employed to obtain wavelength- and duration-tunable solitons from a 20 GHz sinusoidal pulse train generated using a low-cost LiNbO3 Mach–Zehnder amplitude modulator. 25 to 0.8 ps pulse duration tunability was attained under adiabatic compression, while high-quality, low-pedestal solitons as short as 450 fs were still achieved outside of the adiabatic regime. Compressed solitons with similar durations were obtained over the 1540 to 1560 nm wavelength range.
Second-harmonic study of polar symmetry and domain structure in SrTi18O3
Authors: Zhang Lei , Kleemann Wolfgang , Wang Ruiping , Itoh Mitsuru
Published: October 2002

The ferroelectric domain structure of SrTi18O3 is studied via the azimuthal dependence of the second-harmonic (SH) light intensity below Tc≈25 K. Tensor analysis of the SH response reveals locally variant mixtures of eight triclinic polar domains, which transform into an orthorhombic single domain under an electric field E applied perpendicularly to the tetragonal axis, with d22 being the dominant coupling constant.
Adaptive interferometer based on wave mixing in a photorefractive crystal under alternating electric field
Authors: Kamshilin Alexei A. , Grachev Alexander I.
Published: October 2002

Coupling of two waves with different polarization states in a photorefractive crystal under an ac electric field allows us to achieve the linear transformation of a small transient phase shift into the intensity modulation without any output polarization filtering. This can lead to design of an adaptive interferometer with sensitivity that reaches the classical homodyne detection limit.
Near-infrared electroluminescence in polymer composites based on organic nanocrystals
Authors: Maltsev Eugene I. , Lypenko Dmitry A. , Bobinkin Vladimir V. , Tameev Alek R. , Kirillov Sergey V. , Shapiro Boris I. , Schoo Herman F. M. , Vannikov Anatoly V.
Published: October 2002

IR electroluminescence was revealed in single-layer light-emitting diodes based on a type of electroactive polymer nanocomposites-electron-hole conducting aromatic polyimide and organic nanocrystalline particles of cyanine molecules, known as J-aggregates. These materials exhibit a very narrow emission band with a maximum at 815 nm. Dramatic increase of charge-carrier mobility was observed for these layers containing the J-aggregate nanocrystalline phase.