bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification and characterization of a soluble form of lysosome‐associated membrane glycoprotein‐2 (lamp‐2) from rat liver lysosomal contents
Authors: Akasaki Kenji , Tsuji Hiroshi
Published: July 2007

Lysosomal membrane of rat liver contains a highly glycosylated protein referred to as lamp‐2. Lamp‐2 occurs to a significant extent in a soluble fraction of rat liver lysosomes. The soluble form of lamp‐2 (SF‐lamp‐2) was purified to electrophoretic homogeneity. An apparent molecular weight (Mr) of SF‐lamp‐2 on sodium dodecy sulfate‐polyacrylamide gel electrophoresis was determined to be 91,000 which is 5,000 less than that of the membranous form of lamp‐2 (MF‐lamp‐2). SF‐ and MF‐lamp‐2 were very similar to each other in terms of sialic acid content, NH2‐terminal amino acid sequence and isoelectric point. Gel filtration data indicated that native SF‐lamp‐2 has an Mr=360,000. Taken together, SF‐lamp‐2 forms a tetrameric structure consisiting of a homogenous polypeptide lacking a membrane‐spanning domain and a cytoplasmic tail near the COOH‐terminus.
Angiotensin‐converting enzyme inhibitor increases insulin‐induced pp185 phosphorylation in liver and muscle of obese rats
Authors: Carvalho Daniela S. , Villaça Veridiana , Brenelli Sigisfredo L. , Carvalho Carla R. O. , Saad Mario J. A.
Published: July 2007

The clinical use of angiotensin‐converting enzyme (ACE) inhibitors has been associated with increased insulin sensitivity. However, the molecular mechanism is unknown. The authors examined the early steps in insulin action, i.e., the phosphorylation status of the insulin receptor and of the pp185 in liver and muscle of obese rats treated acutely with captopril, using immunoblotting with antiphosphotyrosine antibodies. Following treatment with captopril there was an improvement in insulin‐induced insulin receptor and pp185 phosphorylation in the liver and muscle of obese rats. This finding contribute to an explanation of the mechanism by which ACE inhibitors appear to improve insulin sensitivity.
Isolation and characterization of the mouse ribosomal protein S7 gene
Authors: Annilo Tarmo , Jelina Jelena , Pata Illar , Metspalu Andres
Published: July 2007

We have isolated and characterized the single intron‐containing gene encoding the mouse ribosomal protein S7. The mouse 129SV S7 gene has seven exons and six introns spanning about 5000 nucleotides. The exon‐intron structure of the gene is similar to other vertebrate homologues. Southern blot analysis showed that in addition to the isolated single‐copy intron‐containing gene, there are 10‐12 members in the mouse S7 gene family, which are all most probably processed pseudogenes. The promoter region of rpS7 contains several evolutionarily conserved putative regulatory elements. The main transcription start site was mapped to a T residue within a polypyrimidine tract, 79 nucleotides upstream from AUG codon.
Cloning and sequencing of the homologues of both the bacterial and eukaryotic initiation factor genes (hIF‐2 and heIF‐2γ from archaeal Halobacterium halobium
Authors: Hasegawa Yoshiko , Sawaoka Nozomi , Kado Nozomi , Ochi Minako , Itoh Takuzi
Published: July 2007

The cloning and sequencing of the genes encoding the translational initiation factors (hIF‐2 and heIF‐2 γ) was performed by screening the halophilic archaeon Halobacterium halobium genomic library with a probe constructed from the peptide IGHVDHGK that is conserved in archaeal GTP‐binding elongation factors. The codon usage by the hIF‐2 and heIF‐2 γ genes showed a preference for triplets ending in G or C. This characteristic is almost identical to that of other H. halobium genes. The translated protein of hIF‐2 and heIF‐2 γ genes is made of 414 and 583 amino acid residues, respectively, and contains the sequence motif for the binding of GTP. The sequence of hIF‐2 shows a strong similarity to the initiation factor IF‐2 from Bacteria whereas heIF‐2 γ shows a strong similarity to the initiation factor eIF‐2 γ from Eucarya.
Transcription of the rat p53 gene is induced by a 39kDa protein binding to the p53 promoter region during the liver regeneration
Authors: Lee Minhyung , Park Sunhee , Song Haisun , Park Jong‐sang
Published: July 2007

The adult rat liver is normally in a state of growth arrest. However, cell loss such as partial hepatectomy can induce the proliferation of the hepatocytes. Early after partial hepatectomy, the concentration of p53 mRNA increases during the prereplicative phase. In this study, we identified the cis‐regulatory element involved in the induced transcription of the rat p53 gene by DNase I footprinting assay. This element had a partial homolgy to the AP 1 recognition motif, but the competition study with AP1 oligonucleotide showed that this element was not the AP1 recognition motif. The molecular weight of the binding protein to this motif was determined as 39kDa by southwestern blotting analysis. In vitro transcription assay with the competitor containing the binding motif showed that the 39kDa protein binding to the element was requried for the induced transcription of the rat p53 gene during the liver regeneration.
Thioredoxin fusion/HIV‐1 protease coexpression system for production of soluble human IL6 in E. coli cytoplasm
Authors: Han Bao‐Guang , Song Xiao‐Guo , Peng Shan‐Yun , Wang Jia‐Xi , Ling Shi‐Gan
Published: July 2007

In this paper, thioredoxin (TRX) fusion expression system has been modified to produce soluble human IL6 (hIL6) without TRX moiety in E. coli cytoplasm. A novel TRX gene fusion vector was developed that contained at the 3′‐end of TRX gene a short DNA sequences encoding a linker peptide ‘‐GSGSGVSQNYPIVQHHHHHH‐’, serving not only as a specific HIV‐1 protease site but also providing six contiguous histidine (His) residues to foreign proteins. The cDNA for hIL6 was cloned into this vector resulting in plasmid pTRX@HISIL6. The cDNA for the HIV‐1 protease has been cloned into another compatible plasmid pHMM2, resulting in plasmid pHMM2‐PR. Both plasmids were transformed into E. coli strain GI724, and when induced for expression of both proteins, the correct processing of TRX@HISIL6 was obtained, producing hlL6 with His6‐tag at the N terminus named HISIL6. A fraction of HISIL6 was found in soluble form and could be purified to homogeneity by Ni‐NTA Superflow and ion‐exchange chromatography. The biological activity of purified HISIL6 was measured by MTT method in an IL‐6‐dependent cell line 7TD1 to be 2.1×108 unit/mg.
The effect of heparin and pentosan polysulfate on the thermal stability of yeast alcohol dehydrogenase
Authors: Paulíková Helena , Molnárová Milota , Podhradský Dusan
Published: July 2007

Heparin and pentosan polysulfate as organic polyanions inhibit yeast alcohol dehydrogenase (YADH). The aim of this study was to determine the effect of heparin and pentosan polysulfate on the thermostability of alcohol dehydrogenase. Spectral and kinetic analyses showed that these compounds increase the thermal stability of the enzyme and eliminate entirely thermal aggregation. The thermostabilizing effect of unfractionated heparin and pentosan polysulfate was accelerated in the presence of NAD+. The addition of NAD+ (11 μM) to the incubation medium decreased the inhibition of the YADH activity in the presence of pentosan polysulfate (1.32 μM). Moreover, 38 % of the residual activity of YADH was found after a 5‐rain incubation at 70 °C. These findings indicate that heparinoids not only modulate the enzyme activity but also can prevent the protein's thermal denaturation.
Sequence‐specific DNA binding activity in the RAE28 protein, a mouse homologue of the Drosophila polyhomeotic protein
Authors: Nomura Midori , Takihara Yoshihiro , Motaleb Abdul , Horie Kyoji , Higashinakagawa Toru , Shimada Kazunori
Published: July 2007

The rae28 gene, a mouse homologue of the Drosophila polyhomeotic gene, is involved in the maintenance of the transcriptional repression states of Hox genes. In this study we synthesized the glutathione S transferase‐RAE28 (GST‐RAE28) fusion protein and examined sequence‐specific DNA binding activity in the RAE28 protein by using the selected and amplified binding site method. After five rounds of enrichment, the eluted DNAs were amplified, cloned and sequenced. The sequences of individual oligonucleotides included the following consensus sequences; 5′‐ACCA‐3′, 5′‐ACCCA‐3′, 5′‐CTATCA‐3′ and 5′‐TGCC‐3′. The oligonucleotides including these consensus sequences were show to have significant affinity with the GST‐RAE28 fusion protein. The RAE28 protein was recently shown to form multimeric protein complexes with other members of mouse Pc‐G proteins in the nucleus. These findings strongly suggest that the RAE28 protein constitutes a sequence‐specific DNA binding domain in multimeric Pc‐G protein complexes.
Use of prokaryotically expressed nucleocapsid protein as positive antigen in ELISA
Authors: Kumar S. S. , Renji R. , Saini Mohini , Goel A. C. , Sharma Bhaskar
Published: July 2007

A cDNA library of Rinderpest vaccine virus was prepared in Zap Express vector (Stratagene). The Rinderpest ‘N′ gene specific clones were selected, characterized and thereafter expressed in E. coli XLOLR strain. The expressed protein was found to be immunogenic in western blot with hyperimmune sera. It reacted with rinderpest and ‘N′ protein specific monoclonal antibodies in Enzyme Linked Immunosorbent Assay (ELISA). Prokaryotically expressed ‘N′ protein also gave precipitin band in counter immunoelectrophoresis test (CIE). The expression of N protein was sufficient for its utility as positive antigen in CIE and ELISA used for rinderpest diagnosis.
Role of reducing co‐factor in cerulenin‐insensitivity of 6‐hydroxymellein synthase in carrot cell extract
Authors: Kurosaki Fumiya , Togashi Kousuke , Arisawa Munehisa
Published: July 2007

The activity of 6‐hydroxymellein synthase, a multifunctional polyketide biosynthetic enzyme of carrot, was not inhibited by cerulenin in the presence of NADPH. However, cerulenin showed a marked inhibitory activity to the synthase if the reducing co‐factor was omitted from the assay mixture. The synthase was also sensitive to the antibiotic even in the presence of NADPH when the acyl condensation site and the reducing domain at the reaction center of the enzyme were dissociated under the high ionic strength condition, In addition, the synthase activity was appreciably inhibited when NADH was employed instead of NADPH. These observations strongly suggest that a phosphate group attached to 2′‐position of adenosyl moiety of NADPH molecule plays an important role in the apparent insensitivity of 6‐hydroxymellein synthase toward cerulenin.
Presence and comparison of angiotensin converting enzyme in commercial cell culture sera
Authors: Bramucci Massimo , Miano Antonino , Quassinti Luana , Maccari Ennio , Murri Oretta , Amici Domenico
Published: July 2007

This study was conducted to determine the presence of the angiotensin converting enzyme in commercial sera used in cell culture medium. The aim of the research was to bring the presence of proteinases (angiotensin converting enzyme) to cell culture users' knowledge and to give some data for solving problems about the development of peptides as useful drugs. The enzymes, purified from foetal bovine, adult bovine, foetal equine, adult equine, and human sera, showed molecular weights of about 170 kDa. Captopril and lisinopril inhibited enzyme activities at nanomolar concentrations. The enzymes were able to hydrolyze, with different efficiency, angiotensin I, bradykinin and epidermal mitosis inhibiting pentapeptide. The heat inactivation of commercial sera at 56°C for 30 min showed a reduction of ACE activity of about 35‐80%. Therefore, the presence of ACE activity in commercial sera can influence the activity of biological peptides tested on cell lines cultured “in vitro”.
Total reactive antioxidant potential in human saliva of smokers and non‐smokers
Authors: Kondakova Irina , Lissi E. A. , Pizarro M.
Published: July 2007

Uric acid is the most important non‐enzymatic antioxidant present in human saliva. There is a great variability among individuals, both in salivary uric acid content and saliva total reactive antioxidant potential (TRAP). The uric acid present in saliva correlates with plasma uric acid, suggesting that the former is imported from plasma. There are not statistical differences between uric acid or TRAP values in saliva of smokers and non‐smokers. Also, smoking a cigarette does not modify the levels of antioxidants present in saliva.
Direct Transcriptional Control of the Chloroplast Genes psbA and psaAB Adjusts Photosynthesis to Light Energy Distribution in Plants
Authors: Pfannschmidt Thomas , Nilsson Anders , Tullberg Anna , Link Gerhard , Allen John F.
Published: July 2007

Two photosystems, I and II, absorb and convert light energy in photosynthesis in chloroplasts of green plants. The genes psbA and psaAB of the cytoplasmic chloroplast genome encode core components of photosystem II and photosystem I, respectively. Here we show that the absolute amounts of photosystem I and photosystem II respond, in a complementary manner, to changes in light quality that preferentially excite each photosystem in mustard seedlings. We also show that the initial response to altered energy distribution is a change in the rates of transcription of psbA and psaAB. Changes in chlorophyll fluorescence emission in vivo suggest that the signal initiating this change is the oxidation‐reduction state of plastoquinone, a component of the photosynthetic electron transport chain that connects photosystem I and photosystem II. The results are consistent with transcriptional effects observed previously with chloroplasts isolated in vitro and demonstrate that redox control of chloroplast transcription initiates long‐term adjustments that compensate for imbalance in energy distribution and adapt the whole plant to altered light environments.
Hypoxia, Ischemic Stroke, and Memory Deficits: Prospects for Therapy
Authors: Sun Miao‐Kun
Published: July 2007

Oxygenation of cells and tissues in mammals according to metabolic needs is always a life‐or‐death necessity. Over the last decade, life scientists have gained an impressive understanding of cellular and molecular mechanisms in hypoxic‐ischemic injury and memory deficits, survival, and death. Functional recovery from hypoxia‐ischemia depends on how the individual responds to the insult, and whether appropriate responses are initiated and maintained. Unraveling the biochemical and molecular mechanisms and responses of hypoxia‐ischemia is likely to dramatically shape and improve medical practice in the treatments of hypoxia‐ischemia and memory deficits.
Geldanamycin Induces Heat Shock Protein Expression Through Activation of HSF1 in K562 Erythroleukemic Cells
Authors: Kim Hong Ro , Kang Ho Sung , Kim Han Do
Published: July 2007

HSP90 is one of the most abundant heat shock proteins (HSPs) in eukaryotic cells and is found in complex with several regulatory proteins such as kinases and transcription factors. Geldanamycin (GA), a benzoquinone ansamycin, specifically binds to HSP90 and disrupts the interaction of HSP90 and target proteins. Thus, GA has been used as a specific inhibitor of HSP90. In this study, we examined whether GA could affect protein synthesis and gene expression in the human erythroleukemic cell line K562. Treatment with GA, but not herbimycin A (another benzoquinone ansamycin), highly induced a 70‐kDa protein, which was revealed to be HSP70 by immunoblotting and immunoprecipitation with anti‐HSP70 antibody. The expression of HSP28 was also enhanced by GA. Furthermore, GA induced the activation of heat shock factor 1 (HSF1), but not HSF2, as determined by electromobility shift and electromobility supershift assay. In addition, similar to heat shock treatment, GA induced the phosphorylation of HSF1. Heat shock element‐binding activity and phosphorylation of HSF1 were attenuated 3 h after GA treatment. These results indicate that the functional inactivation of HSP90 by GA potentially stimulates the expression of heat shock proteins through activation of HSF1.
Investigation of the Orientation of Purple Membrane Sheets in Langmuir‐Blodgett Films by a Quartz Crystal Microbalance
Authors: Lu Tao , Rothe Ulrich , Liebau Maik , Schaffer Heike , Hufnagel Peter , Bakowsky Udo
Published: July 2007

By means of the quartz crystal microbalance (QCM), a convenient method was developed to determine the degree of orientation of purple membrane (PM) sheets on the air/water interface. Langmuir‐Blodgett films from both wild‐type and SH‐mutant PM (bR D36C) were vertically deposited on the surface of goldsputtered AT‐cut quartz crystals. The shift of resonance frequency of the QCM during a special washing protocol allowed us to differentiate between physically adsorbed PM fragments and any PM attached to the gold surface via chemical bonds. By washing with organic solvents, complete desorption of the wild‐type PM was achieved, whereas for the SH‐mutant, 60% of the PM fragments could not be detached from the surface. These PM sheets should be oriented with the cytoplasmic side facing the water subphase so that their SH‐groups can chemically bind to the gold surface of the quartz plate.
Peptide Binding Inhibits Aggregation of Soluble MHC Class II in Solution
Authors: Arimilli Subhashini , Astafieva Irina , Mukku Prabha V. , Cardoso Cristina , Deshpande Shrikant , Nag Bishwajit
Published: July 2007

Affinity‐purified major histocompatability complex (MHC) class II molecules are known to bind antigenic peptide in vitro. This peptide‐bound MHC class II is known to undergo a change in structure upon stable binding of antigenic peptide. Previous results from our, and other laboratories, have suggested a relationship between MHC class II structure and peptide association that enables class II to enter into a stable conformation upon peptide binding. In this report we describe that stable binding of high‐affinity antigenic peptide to MHC class II molecule results in transition of aggregated purified MHC class II proteins to a stable heterodimeric state. Such transition was demonstrated by using purified human HLA‐DR2 class II molecule and high‐affinity myelin basic protein (MBP) 83‐102)Y83 peptide. Highly aggregated purified DR2 (high molecular weight; HMW) was first separated from heterodimer (low molecular weight; LMW) in the presence of 50‐fold molar excess of MBP(83‐102)Y83 peptide. We then show that the aggregated HMW preparation can be successfully converted into a stable dimer by further incubation with MBP(83‐102)Y83 and changing various binding parameters such as pH, temperature, reducing agent, and peptide concentrations. Under optimized conditions, the highly aggregated inactive DR2 molecules can be completely loaded with the antigenic peptide. The transformed heterodimers with bound peptide prepared by this method are biologically active, as shown by their ability to induce the production of gamma‐interferon by SS8T transformed human T cells. These results suggest that in solution, MHC class II molecules may be aggregated in the absence of bound peptide. Such aggregated MHC class II molecules can be converted to stable and biologically active heterodimers in the presence of high‐affinity antigenic peptide.
Lucigenin Luminescence Elicited by Microsomes and Its Modulation by Nitroazole Compounds
Authors: Schepetkin I. A.
Published: July 2007

The lucigenin luminescence elicited by rat liver microsomes and its modulation by the nitroazole compounds metronidazole and sanazole (drug AK‐2123), as well as the rates of lucigenindependent NADPH consumption and cytochrome c reduction, were studied. The obtained data suggest that the luminescence can be the result of univalent lucigenin reduction by microsomal NAD(P)Hreductases, generation of superoxide anion radical in the redox cycle of lucigenin radicals, dioxetane formation by (di)oxygenases, and catalytic action of cytochrome P450 heme on dioxetane decomposition, followed by light emission.
Effect of 13‐Hydroperoxyoctadecadienoic Acid on the Supply of Arachidonic Acid for Prostaglandin Synthesis from Arachidonoyl‐CoA Mediated by the Cytosolic or Microsomal acyl‐CoA Hydrolase in Rabbit Kidney Medulla
Authors: Sakuma Satoru , Fujimoto Yohko , Yoshimura Mari , Saeki Kazuki , Mukai Akiko , Akimoto Manabu , Fujita Tadashi
Published: July 2007

The effects of 13‐hydroperoxyoctadecadienoic acid (13‐HPODE) on the cytosolic or microsomal acyl‐CoA hydrolase (ACH) activity in rabbit kidney medulla and on the ACH‐mediated prostaglandin (PG) formation fromarachidonoyl‐CoA (AA‐CoA) were examined. 13‐HPODE (10, 20, and 50 mu M) had no effect on the cytosolic ACH activity but significantly inhibited the activity of the microsomal enzyme (43‐57% inhibition). PG formation was measured as follows: AA‐CoA (20 nmol) was preincubated with the cytosolic or microsomal fraction (as the source of ACH) in the presence or absence of 13‐HPODE for 5 min at 37° C, followed by incubation with the microsomal fraction (as the source of PG‐synthesizing enzymes), hydroquinone and reduced glutathione for 5 min at 37° C, and the PGs formed were measured by HPLC, with use of 9‐anthryldiazomethane for derivatization. 13‐HPODE reduced the PG formation when the microsomal fraction, but not the cytosolic fraction, was used as the source of ACH (10,20, and 50 mu M; 28‐55% inhibition). These results suggest that 13‐HPODE may modulate PG levels in rabbit kidney medulla by inhibiting the microsomal ACH activity.
Fine Structure of the Human Translocation Protein 1 (HTP1/TLOC1) Gene
Authors: Daimon Makoto , Susa Shinji , Kato Takeo
Published: July 2007

We characterized the genomic region corresponding to the human translocation protein 1 (HTP1/TLOC1) cDNA previously reported. An experiment using rapid amplification of cDNA ends revealed that the transcription initiation site was at 12 bp upstream from the translation initiation codon ATG. Using direct‐sequencing PCR, we determined precise intron/exon boundaries and intron‐exon composition of the gene. The gene region spanned 28 kb and was composed of eight exons and seven introns. The lengths of exons and introns range from 48 to > 1707 bp and from 0.25 to 8.2 kb, respectively. The translation initiation codon and the termination codon were located in exons 1 and 8, respectively. The nucleotide sequences of the introns were also determined in the region around the intron/exon boundaries for 63 to 442 bp. All of the sequences around the intron/exon boundaries were consistent with the 5′ and 3′ consensus sequences for splice junctions of transcribed genes. Putative lariat sequences were identified between 28 and 64 nucleotides from the 3′ splice junction for all seven introns. DNA walking experiments revealed a promoter region of 600 bp. The promoter region did not contain an apparent TATA box or a CAT box but did contain Evi‐1, GATA, v‐Myb, MZF1, and AP‐1 binding sites‐factors known as regulatory factors on expression of the gene in blood cells. Therefore, this gene may be one such gene.
Variation of Hepatic Methotrexate 7‐Hydroxylase Activity in Animals and Humans
Authors: Kitamura Shigeyuki , Sugihara Kazumi , Nakatani Keiko , Ohta Shigeru , Oh‐Hara Toshinari , Ninomiya Shin‐Ichi , Green Carol E. , Tyson Charles A.
Published: July 2007

This study deals with individual and species variations in the converting activity of methotrexate (MTX) to 7‐hydroxymethotrexate in animals and humans. When MTX 7‐hydroxylase was assayed in six human liver cytosols, a 48‐fold range of intersubject variation of the activity was observed. The variations were correlated to the concentrations of aldehyde oxidase activity in human subjects assayed with benzaldehyde as a substrate. Species differences of liver MTX 7‐hydroxylase activity were also observed. The activity was highest in rabbits, followed by rats, hamsters, and monkeys but was undetectable in dogs. Strain differences of MTX 7‐hydroxylase activity based on aldehyde oxidase activity were also observed in rats and mice. The results suggest that aldehyde oxidase functions as MTX 7‐hydroxylase in livers of animals and humans, and the observed differences of MTX 7‐hydroxylase activity are due to variations in the amount of aldehyde oxidase present.
Oxidative Stress, Antioxidant Defenses, and Damage Removal, Repair, and Replacement Systems
Authors: Davies Kelvin J. A.
Published: July 2007

Oxidative stress is an unavoidable consequence of life in an oxygen‐rich atmosphere. Oxygen radicals and other activated oxygen species are generated as by‐products of aerobic metabolism and exposure to various natural and synthetic toxicants. The “Oxygen Paradox” is that oxygen is dangerous to the very life‐forms for which it has become an essential component of energy production. The first defense against oxygen toxicity is the sharp gradient of oxygen tension, seen in all mammals, from the environmental level of 20% to a tissue concentration of only 3‐4% oxygen. These relatively low tissue levels of oxygen prevent most oxidative damage from ever occurring. Cells, tissues, organs, and organisms utilize multiple layers of antioxidant defenses and damage removal, and replacement or repair systems in order to cope with the remaining stress and damage that oxygen engenders. The enzymes comprising many of these protective systems are inducible under conditions of oxidative stress adaptation, in which the expression of over 40 mammalian genes is upregulated. Mitotic cells have the additional defensive ability of entering a transient growth‐arrested state (in the first stages of adaptation) in which DNA is protected by histone proteins, energy is conserved by diminished expression of nonessential genes, and the expression of shock and stress proteins is greatly increased. Failure to fully cope with an oxidative stress can switch mitotic cells into a permanent growth‐arrested, senescence‐like state in which they may survive for long periods. Faced with even more severe oxidative stress, or the declining protective enzymes and adaptive capacity associated with aging, cells may “sacrifice themselves” by apoptosis, which protects surrounding healthy tissue from further damage. Only under the most severe oxidative stress conditions will cells undergo a necrotic death, which exposes surrounding tissues to the further vicissitudes of an inflammatory immune response. This remarkable array of systems for defense; damage removal, replacement, and repair; adaptation; growth modulation; and apoptosis make it possible for us to enjoy life in an oxygen‐rich environment.
Cardiovascular Development and the Colonizing Cardiac Neural Crest Lineage
Authors: Snider Paige , Olaopa Michael , Firulli Anthony B. , Conway Simon J.
Published: July 2007

Although it is well established that transgenic manipulation of mammalian neural crest-related gene expression and microsurgical removal of premigratory chicken andXenopusembryonic cardiac neural crest progenitors results in a wide spectrum of both structural and functional congenital heart defects, the actual functional mechanism of the cardiac neural crest cells within the heart is poorly understood. Neural crest cell migration and appropriate colonization of the pharyngeal arches and outflow tract septum is thought to be highly dependent on genes that regulate cell-autonomous polarized movement (i.e., gap junctions, cadherins, and noncanonicalWnt1pathway regulators). Once the migratory cardiac neural crest subpopulation finally reaches the heart, they have traditionally been thought to participate in septation of the common outflow tract into separate aortic and pulmonary arteries. However, several studies have suggested these colonizing neural crest cells may also play additional unexpected roles during cardiovascular development and may even contribute to a crest-derived stem cell population. Studies in both mice and chick suggest they can also enter the heart from the venous inflow as well as the usual arterial outflow region, and may contribute to the adult semilunar and atrioventricular valves as well as part of the cardiac conduction system. Furthermore, although they are not usually thought to give rise to the cardiomyocyte lineage, neural crest cells in the zebrafish (Danio rerio) can contribute to the myocardium and may have different functions in a species-dependent context. Intriguingly, both ablation of chick andXenopuspremigratory neural crest cells, and a transgenic deletion of mouse neural crest cell migration or disruption of the normal mammalian neural crest gene expression profiles, disrupts ventral myocardial function and/or cardiomyocyte proliferation. Combined, this suggests that either the cardiac neural crest secrete factor/s that regulate myocardial proliferation, can signal to the epicardium to subsequently secrete a growth factor/s, or may even contribute directly to the heart. Although there are species differences between mouse, chick, and Xenopus during cardiac neural crest cell morphogenesis, recent data suggest mouse and chick are more similar to each other than to the zebrafish neural crest cell lineage. Several groups have used the genetically definedPax3(splotch) mutant mice model to address the role of the cardiac neural crest lineage. Here we review the current literature, the neural crest-related role of thePax3transcription factor, and discuss potential function/s of cardiac neural crest-derived cells during cardiovascular developmental remodeling.
Time‐varying parameter estimation with application to trajectory tracking
Authors: Bousson K.
Published: July 2007

Purpose

This paper is concerned with an online parameter estimation algorithm for nonlinear uncertain time‐varying systems for which no stochastic information is available.

Design/methodology/approach

The estimation procedure, called nonlinear learning rate adaptation (NLRA), computes an individual adaptive learning rate for each parameter instead of using a single adaptive learning rate for all the parameters as done in stochastic approximation, each individual learning rate being controlled by a meta‐learning rate rule for the sake of minimizing the measurement prediction error. The method does not require stochastic information about the system model and the measurement noise covariance matrices contrarily to the Kalman filtering. Numerical results about aircraft navigation trajectory tracking show that the method is able to estimate reliably time‐varying parameters even in presence of measurement noise.

Findings

The proposed algorithm is practically insensitive to changes in the meta‐learning rate. Therefore, the performance of the method is stable with respect to the tuning parameter of the algorithm.

Practical implications

The proposed NLRA method may be adopted for recursive parameter estimation of uncertain systems when no stochastic information is available. It may also be used for process regulation and dynamic system stabilization in feedback control applications.

Originality/value

Provides a method for fast and practical computation of parameter estimates without requiring to know the model and measurement noise covariance matrices contrarily to existing stochastic estimation methods.
Aesthetic theory and logo design: examining consumer response to proportion across cultures
Authors: Pittard Narelle , Ewing Michael , Jevons Colin
Published: July 2007

Purpose

The purpose of this study is to investigate reactions to the divine proportion (a ratio of 1: 1.618) in logo design across different cultures.

Design/methodology/approach

The approach is a survey in three different countries: Australia, Singapore and South Africa.

Findings

Results showed there is universal preference for the divine proportion across cultures. Logos based on forms found in nature that were expressed in the divine proportion were most preferred, but for artificially constructed logos, a 1:1 ratio was preferred.

Research limitations/implications

A limited set of ratios were considered. Further research could investigate different ratios and different logos.

Practical implications

International brand managers should commission designs that use natural forms based on the divine proportion. Different national cultures react similarly to logo designs, in contrast to many other fields of business where strong cultural differences exist.

Originality/value

This paper is the first exploration of responses to the divine proportion in logo design across cultures.
Service failure and recovery strategies in the restaurant sector
Authors: Dutta Kirti , Venkatesh Umashankar , Parsa H.G.
Published: July 2007

Purpose

The purpose of this research is to explore the reasons for service failure in restaurants. The paper aims to give insights into customers' perceptions and response regarding service failure and recovery and to try to draw a parallel between consumers in a developing economy like India and the same in a developed society, such as USA.

Design/methodology/approach

The paper is empirical and involves data from 200 respondents from India and the USA. The sampling unit is individual restaurant customers and the data collection instrument is a structured, non‐disguised questionnaire. The questionnaires have been administered through personal interviews.

Findings

The study found conclusive results on the reasons for service failure in the restaurant business in the context of developed and developing economies. It also sheds light on the behavioral aspects of customers' perception towards these failures and their responses to the same. The paper further looked into the recovery strategy employed by restaurants and the customers' perception towards the recovery strategies.

Practical implications

The study has important managerial implications as it facilitates the understanding of where and how the failure‐points occur and how customers perceive and react to them. The paper is also helpful in designing policies and procedures to proactively weed‐out such failure‐points and, in case of their occurrence, design responses to the same.

Originality/value

The paper is valuable as very little has been done in the Indian context. It also creates a comparative perspective as to service failure in the restaurant sector between a developed and a developing country.
Measuring efficiency of the hotel and restaurant sector: the case of India
Authors: Sanjeev Gunjan M.
Published: July 2007

Purpose

The purpose of this research is to provide exploratory insights on measurement of efficiency of the hotel and restaurant companies operating in India.

Design/methodology/approach

This study will use a linear programming‐based approach, data envelopment analysis (DEA), to evaluate the efficiency of hotel and restaurant companies operating in India. DEA is a method of evaluating the relative efficiency of decision‐making units (DMUs). In this study the decision‐making units are the hotel and restaurant companies. The study further explores if there exists a relationship between the efficiency and size of the hotel and restaurant companies.

Findings

The DEA model used in this study assigns efficiency scores to each of the hotel and restaurant companies taken in the sample of 68 companies for the year 2004‐2005. The study also explores whether there is a relationship between the efficiency and size of the hotel and restaurant companies.

Practical implications

As this study evaluates the efficiency of the hotel and restaurant sector, it separates the most efficient hotel and restaurant companies from the non‐efficient ones. The study identifies the top performers in this sector. Also, managers get important insights for their strategic and operational decisions to improve performance.

Originality/value

There are very few known studies that have measured the efficiency of the hotel and restaurant companies. This study is one of the few exploratory initiatives in the Indian context.
New business models for the new media world
Authors: Berman Saul J. , Abraham Steven , Battino Bill , Shipnuck Louisa , Neus Andreas
Published: July 2007

Purpose

The authors perform market trend analysis and to examine the clash between new and traditional media and explore future industry competitive scenarios.

Design/methodology/approach

IBM conducted a comprehensive study that included interviews with leaders of media companies and an in‐depth analysis of the factors that are shaping the industry outlook. IBM conducted in‐person interviews with more than 75 senior media executives, industry analysts, economists and technology visionaries and also worked with the Economist Intelligence Unit to survey another 125 industry executives.

Findings

IBM sees four primary business models emerging – traditional media, walled communities, content hyper‐syndication and new platform aggregation. The research also found evidence of another developing conflict that it calls the media divide. It could pit partner against partner in a struggle for growth.

Practical implications

IBM proposes seven industry‐specific recommendations for incumbent media companies as they face the immediate threat from new entrants and eventual collisions with traditional partners: Deliver experiences, not just content. Leverage virtual worlds. Innovate business models. Invest in interactive, measurable advertising services and platforms. Redefine partnerships, while mitigating fallout. Shift investment from traditional business to new models. Create a flexible business design.

Originality/value

The article offers a combination of market evolution analysis, future market scenarios and recommendations for gaining first mover advantage.
Quality of life in Friedreich ataxia: what clinical, social and demographic factors are important?
Authors: Wilson C. L. , Fahey M. C. , Corben L. A. , Collins V. R. , Churchyard A. J. , Lamont P. J. , Delatycki M. B.
Published: July 2007

The aim of this study was to examine the impact of Friedreich ataxia (FRDA) on quality of life (QOL) using a generic tool to explore factors potentially associated with health status. Sixty‐three individuals with genetically confirmed FRDA, self completed the Medical Outcomes Study 36 item Short Form Health Survey Version 2 (SF‐36V2) and were assessed using the FRDA Rating Scale. Disease‐specific, demographic, and social characteristics were also recorded. SF‐36V2 results were compared with Australian population norms. Sample subgroups of disease severity and age at disease onset were reviewed. Physical and mental component summaries were examined in relation to clinical and social characteristics using multiple linear regression. QOL is significantly worse in individuals with FRDA compared with population norms. Those with severe disease did not perceive a lower QOL than those with mild or moderate disease except in their physical functioning. A later age of onset and increased disease severity were negatively associated with physical QOL, whilst, increased disease duration was positively associated with mental QOL. There were limitations associated with the use of SF‐36V2 in the FRDA population. Further exploration of health‐related QOL and FRDA may benefit from the use of a more appropriate generic tool.
Lateralized ERP components related to spatial orienting: Discriminating the direction of attention from processing sensory aspects of the cue
Authors: Jongen Ellen M. M. , Smulders Fren T. Y. , Van der Heiden Joep S. H.
Published: July 2007

Two spatial cueing experiments were conducted to examine the functional significance of lateralized ERP components after cue‐onset and to discriminate components related to sensory cue aspects and components related to the direction of attention. In Experiment 1, a simple detection task was presented. In Experiment 2, attentional selection was augmented. Two unimodal visual cueing tasks were presented using nonlateralized line cues and lateralized arrow cues. Lateralized cue effects and modulation after stimulus onset were stronger in Experiment 2. An early posterior component was related to the physical shape of arrows. A posterior negativity (EDAN) may be related to the encoding of direction from arrow cues. An anterior negativity (ADAN) and a posterior positivity (LDAP) were related to the direction of attention. The ADAN was delayed when it was more difficult to derive cue meaning. Finally, the data suggested an overlap of the LDAP and the EDAN.
Conceivability, Imagination and Modal Knowledge*
Authors: FIOCCO M. ORESTE
Published: July 2007

The notion of conceivability has traditionally been regarded as crucial to an account of modal knowledge. Despite its importance to modal epistemology, there is no received explication of conceivability. One purpose of this paper is to argue that the notion is not fruitfully explicated in terms of the imagination. The most natural way of presenting a notion of conceivability qua imaginability is open to cogent criticism. In order to avoid such criticism, an advocate of the modal insightfulness of the imagination must broaden the idea of what it is to be imaginable. I argue that this required broadening renders the imagination idle (in this context). Consequently, I distinguish two different accounts of the evidential basis of modal knowledge and present a more general argument that concludes that the very notion of conceivability should be eschewed in modal epistemology.
Regulation of the
mpt
Operon in
Listeria innocua
by the ManR Protein
Authors: Xue Junfeng , Miller Kurt W.
Published: July 2007

The phosphotransferase system regulation domain (PRD)-containing activator, ManR, is required for glucose-controlled transcription of the
m
annose
p
ermease
t
wo (
mpt
) operon in
Listeria innocua
. His-871 in ManR PRD-II is needed for
mpt
repression in glucose-free media. His-506 in PRD-I is needed for
mpt
induction by glucose.
Rcs and PhoPQ Regulatory Overlap in the Control ofSalmonella entericaVirulence
Authors: García-Calderón Clara B. , Casadesús Josep , Ramos-Morales Francisco
Published: July 2007

Genetic screens based on the use of MudJ-generatedlacfusions permitted the identification of novel genes regulated by the Rcs signal transduction system inSalmonella entericaserovar Typhimurium. Besides genes that are also found in theEscherichia coligenome, our screens identifiedSalmonella-specific genes regulated by RcsB, includingbapA,siiE,srfA, andsrfB. Here we show that thesrfABCoperon is negatively regulated by RcsB and by PhoP. In vivo studies using mutants with constitutive activation of the Rcs and/or PhoPQ system suggested that there is an overlap between these regulatory systems in the control ofSalmonellavirulence.
Targeted cell replacement with bone marrow cells for airway epithelial regeneration
Authors: Wong Amy P. , Dutly Andre E. , Sacher Adrian , Lee Haeyul , Hwang David M. , Liu Mingyao , Keshavjee Shaf , Hu Jim , Waddell Thomas K.
Published: July 2007

It has been suggested that some adult bone marrow cells (BMC) can localize to the lung and develop tissue-specific characteristics including those of pulmonary epithelial cells. Here, we show that the combination of mild airway injury (naphthalene-induced) as a conditioning regimen to direct the site of BMC localization and transtracheal delivery of short-term cultured BMC enhances airway localization and adoption of an epithelial-like phenotype. Confocal analysis of airway and alveolar-localized BMC (fluorescently labeled) with epithelial markers shows expression of the pulmonary epithelial proteins, Clara cell secretory protein, and surfactant protein C. To confirm epithelial gene expression by BMC, we generated transgenic mice expressing green fluorescent protein (GFP) driven by the epithelial-specific cytokeratin-18 promoter and injected BMC from these mice transtracheally into wild-type recipients after naphthalene-induced airway injury. BMC retention in the lung was observed for at least 120 days following cell delivery with increasing GFP transgene expression over time. Some BMC cultured in vitro over time also expressed GFP transgene, suggesting epithelial transdifferentiation of the BMC. The results indicate that targeted delivery of BMC can promote airway regeneration.
Death of Parents and Adult Psychological and Physical Well-Being
Authors: Marks Nadine F. , Jun Heyjung , Song Jieun
Published: July 2007

Guided by a life course perspective, attachment theory, and gender theory, this study aims to examine the impact of death of a father, a mother, or both parents, as well as continuously living with one or both parents dead (in contrast to having two parents alive) on multiple dimensions of psychological well-being (depressive symptoms, happiness, self-esteem, mastery, and psychological wellness), alcohol abuse (binge drinking), and physical health (self-assessed health). Analyses of longitudinal data from 8,865 adults in the National Survey of Families and Households 1987-1993 reveal that a father's death leads to more negative effects for sons than daughters and a mother's death leads to more negative effects for daughters than sons. Problematic effects of parent loss are reflected more in men's physical health reports than women's. This study's results suggest that family researchers and practitioners working with aging families should not underestimate the impact of filial bereavement on adult well-being.
The complete genomes of three viruses assembled from shotgun libraries of marine RNA virus communities
Authors: Culley Alexander I , Lang Andrew S , Suttle Curtis A
Published: July 2007

Background

RNA viruses have been isolated that infect marine organisms ranging from bacteria to whales, but little is known about the composition and population structure of the in situ marine RNA virus community. In a recent study, the majority of three genomes of previously unknown positive-sense single-stranded (ss) RNA viruses were assembled from reverse-transcribed whole-genome shotgun libraries. The present contribution comparatively analyzes these genomes with respect to representative viruses from established viral taxa.

Results

Two of the genomes (JP-A and JP-B), appear to be polycistronic viruses in the proposed order Picornavirales that fall into a well-supported clade of marine picorna-like viruses, the characterized members of which all infect marine protists. A temporal and geographic survey indicates that the JP genomes are persistent and widespread in British Columbia waters. The third genome, SOG, encodes a putative RNA-dependent RNA polymerase (RdRp) that is related to the RdRp of viruses in the family Tombusviridae, but the remaining SOG sequence has no significant similarity to any sequences in the NCBI database.

Conclusion

The complete genomes of these viruses permitted analyses that resulted in a more comprehensive comparison of these pathogens with established taxa. For example, in concordance with phylogenies based on the RdRp, our results support a close homology between JP-A and JP-B and RsRNAV. In contrast, although classification of the SOG genome based on the RdRp places SOG within the Tombusviridae, SOG lacks a capsid and movement protein conserved within this family and SOG is thus likely more distantly related to the Tombusivridae than the RdRp phylogeney indicates.