bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation between Genotypic Diversity, Lipooligosaccharide Gene Locus Class Variation, and Caco-2 Cell Invasion Potential of
Campylobacter jejuni
Isolates from Chicken Meat and Humans: Contribution to Virulotyping
Authors: Habib Ihab , Louwen Rogier , Uyttendaele Mieke , Houf Kurt , Vandenberg Olivier , Nieuwenhuis Edward E. , Miller William G. , van Belkum Alex , De Zutter Lieven
Published: May 2009

Significant interest in studying the lipooligosaccharide (LOS) of
Campylobacter jejuni
has stemmed from its potential role in postinfection paralytic disorders. In this study we present the results of PCR screening of five LOS locus classes (A, B, C, D, and E) for a collection of 116
C. jejuni
isolates from chicken meat (
n
= 76) and sporadic human cases of diarrhea (
n
= 40). We correlated LOS classes with clonal complexes (CC) assigned by multilocus sequence typing (MLST). Finally, we evaluated the invasion potential of a panel of 52 of these
C. jejuni
isolates for Caco-2 cells. PCR screening showed that 87.1% (101/116) of isolates could be assigned to LOS class A, B, C, D, or E. Concordance between LOS classes and certain MLST CC was revealed. The majority (85.7% [24/28]) of
C. jejuni
isolates grouped in CC-21 were shown to express LOS locus class C. The invasion potential of
C. jejuni
isolates possessing sialylated LOS (
n
= 29; classes A, B, and C) for Caco-2 cells was significantly higher (
P
< 0.0001) than that of
C. jejuni
isolates with nonsialylated LOS (
n
= 23; classes D and E). There was no significant difference in invasiveness between chicken meat and human isolates. However,
C. jejuni
isolates assigned to CC-206 (correlated with LOS class B) or CC-21 (correlated with LOS class C) showed statistically significantly higher levels of invasion than isolates from other CC. Correlation between LOS classes and CC was further confirmed by pulsed-field gel electrophoresis. The present study reveals a correlation between genotypic diversity and LOS locus classes of
C. jejuni
. We showed that simple PCR screening for
C. jejuni
LOS classes could reliably predict certain MLST CC and add to the interpretation of molecular-typing results. Our study corroborates that sialylation of LOS is advantageous for
C. jejuni
fitness and virulence in different hosts. The modulation of cell surface carbohydrate structure could enhance the ability of
C. jejuni
to adapt to or survive in a host.
Conjugative Type 4 Secretion System of a Novel Large Plasmid from the ChemoautotrophTetrathiobacter kashmirensisand Construction of Shuttle Vectors forAlcaligenaceae
Authors: Dam Bomba , Ghosh Wriddhiman , Das Gupta Sujoy K.
Published: May 2009

Tetrathiobacterspp. and other members of theAlcaligenaceaeare metabolically versatile and environmentally significant. A novel, ∼60-kb conjugative plasmid, pBTK445, from the sulfur chemolithoautotrophTetrathiobacter kashmirensis, was identified and characterized. This plasmid exists at a low copy number of 2 to 3 per host chromosome. The portion of pBTK445 sequenced so far (∼25 kb) harbors genes putatively involved in replication, transfer functions, partition, and UV damage repair. A 1,373-bp region was identified as the minimal replicon. This region contains arepAgene encoding a protein belonging to the RPA (replication protein A) superfamily and an upstream, iteron-basedoriV. A contiguous 11-gene cluster homologous to various type 4 secretion systems (T4SSs) was identified. Insertional inactivation demonstrated that this cluster is involved in the conjugative transfer functions of pBTK445, and thus, it was named thetagB(transfer-associated gene homologous tovirB) locus. The core and peripheral TagB components show different phylogenetic affinities, suggesting that this system has evolved by assembling components from evolutionarily divergent T4SSs. AvirD4homolog, putatively involved in nucleoprotein transfer, is also present downstream of thetagBlocus. Although pBTK445 resembles IncP plasmids in terms of its genomic organization and the presence of an IncP-specifictrbMhomolog, it also shows several unique features. Unlike that of IncP, theoriTof pBTK445 is located in close proximity to theoriV, and atraLhomolog, which is generally present in the TraI locus of IncP, is present in pBTK445 in isolation, upstream of thetagBlocus. A significant outcome of this study is the construction of conjugative shuttle vectors forTetrathiobacterand related members of theAlkaligenaceae.
Identification of a Novel Alkaliphilic Esterase Active at Low Temperatures by Screening a Metagenomic Library from Antarctic Desert Soil
Authors: Heath Caroline , Hu Xiao Ping , Cary S. Craig , Cowan Donald
Published: May 2009

A novel esterase was identified through functional screening of a metagenomic library in
Escherichia coli
obtained from Antarctic desert soil. The 297-amino-acid sequence had only low (<29%) similarity to a putative esterase from
Burkholderia xenovorans
. The enzyme was active over a temperature range of 7 to 54°C and at alkaline pH levels and is a potential candidate for industrial application.
Enterocin 96, a Novel Class II Bacteriocin Produced by
Enterococcus faecalis
WHE 96, Isolated from Munster Cheese
Authors: Izquierdo Esther , Wagner Camille , Marchioni Eric , Aoude-Werner Dalal , Ennahar Saïd
Published: May 2009

Enterococcus faecalis
WHE 96, a strain isolated from soft cheese based on its anti-
Listeria
activity, produced a 5,494-Da bacteriocin that was purified to homogeneity by ultrafiltration and cation-exchange and reversed-phase chromatographies. The amino acid sequence of this bacteriocin, named enterocin 96, was determined by Edman degradation, and its structural gene was sequenced, revealing a double-glycine leader peptide. After a comparison with other bacteriocins, it was shown that enterocin 96 was a new class II bacteriocin that showed very little similarity with known structures. Enterocin 96 was indeed a new bacteriocin belonging to class II bacteriocins. The activity spectrum of enterocin 96 covered a wide range of bacteria, with strong activity against most gram-positive strains but very little or no activity against gram-negative strains.
Flow-Based Microfluidic Device for Quantifying Bacterial Chemotaxis in Stable, Competing Gradients
Authors: Englert Derek L. , Manson Michael D. , Jayaraman Arul
Published: May 2009

Chemotaxis is the migration of cells in gradients of chemoeffector molecules. Although multiple, competing gradients must often coexist in nature, conventional approaches for investigating bacterial chemotaxis are suboptimal for quantifying migration in response to gradients of multiple signals. In this work, we developed a microfluidic device for generating precise and stable gradients of signaling molecules. We used the device to investigate the effects of individual and combined chemoeffector gradients on
Escherichia coli
chemotaxis. Laminar flow-based diffusive mixing was used to generate gradients, and the chemotactic responses of cells expressing green fluorescent protein were determined using fluorescence microscopy. Quantification of the migration profiles indicated that
E. coli
was attracted to the quorum-sensing molecule autoinducer-2 (AI-2) but was repelled from the stationary-phase signal indole. Cells also migrated toward higher concentrations of isatin (indole-2,3-dione), an oxidized derivative of indole. Attraction to AI-2 overcame repulsion by indole in equal, competing gradients. Our data suggest that concentration-dependent interactions between attractant and repellent signals may be important determinants of bacterial colonization of the gut.
Ustilago maydis
Rho1 and 14-3-3 Homologues Participate in Pathways Controlling Cell Separation and Cell Polarity
Authors: Pham Cau D. , Yu Zhanyang , Sandrock Björn , Bölker Michael , Gold Scott E. , Perlin Michael H.
Published: May 2009

Proteins of the 14-3-3 and Rho-GTPase families are functionally conserved eukaryotic proteins that participate in many important cellular processes such as signal transduction, cell cycle regulation, malignant transformation, stress response, and apoptosis. However, the exact role(s) of these proteins in these processes is not entirely understood. Using the fungal maize pathogen,
Ustilago maydis
, we were able to demonstrate a functional connection between Pdc1 and Rho1, the
U. maydis
homologues of 14-3-3ε and Rho1, respectively. Our experiments suggest that Pdc1 regulates viability, cytokinesis, chromosome condensation, and vacuole formation. Similarly,
U. maydis
Rho1 is also involved in these three essential processes and exerts an additional function during mating and filamentation. Intriguingly, yeast two-hybrid and epistasis experiments suggest that both Pdc1 and Rho1 could be constituents of the same regulatory cascade(s) controlling cell growth and filamentation in
U. maydis
. Overexpression of
rho1
ameliorated the defects of cells depleted for Pdc1. Furthermore, we found that another small G protein, Rac1, was a suppressor of lethality for both Pdc1 and Rho1. In addition, deletion of
cla4
, encoding a Rac1 effector kinase, could also rescue cells with Pdc1 depleted. Inferring from these data, we propose a model for Rho1 and Pdc1 functions in
U. maydis
.
Isolation and Characterization of Senescent
Cryptococcus neoformans
and Implications for Phenotypic Switching and Pathogenesis in Chronic Cryptococcosis
Authors: Jain Neena , Cook Emily , Xess Immaculata , Hasan Fahmi , Fries Dietrich , Fries Bettina C.
Published: May 2009

Although several virulence factors and associated genes have been identified, the mechanisms that allow
Cryptococcus neoformans
to adapt during chronic infection and to persist in immunocompromised hosts remain poorly understood. Characterization of senescent cells of
C. neoformans
demonstrated that these cells exhibit a significantly enlarged cell body and capsule but still cross the blood-brain barrier.
C. neoformans
cells with advanced generational age are also more resistant to phagocytosis and killing by antifungals, which could promote their selection during chronic disease in humans. Senescent cells of RC-2, a
C. neoformans
strain that undergoes phenotypic switching, manifest switching rates up to 11-fold higher than those of younger cells. Infection experiments with labeled cells suggest that senescent yeast cells can potentially accumulate in vivo. Mathematical modeling incorporating different switching rates demonstrates how increased switching rates promote the emergence of hypervirulent mucoid variants during chronic infection. Our findings introduce the intriguing concept that senescence in eukaryotic pathogens could be a mechanism of microevolution that may promote pathoadaptation and facilitate evasion of an evolving immune response.
A Subunit of Protein Kinase A Regulates Growth and Differentiation in the FungusMucor circinelloides
Authors: Ocampo J. , Fernandez Nuñez L. , Silva F. , Pereyra E. , Moreno S. , Garre V. , Rossi S.
Published: May 2009

The cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling pathway plays a role in regulating development, growth, and virulence in a number of fungi. To determine whether PKA plays a similar function in zygomycete fungi, a mutant ofMucor circinelloideswas generated that lackspkaR1, one of the regulatory subunits of PKA. The mutant showed a reduction in growth and alterations in germination rates, cell volume, germ tube length, and asexual sporulation. The lack ofpkaR1gene resulted in a highly decreased, but not null, cAMP binding activity and in a protein kinase activity that was still dependent on cAMP, although with a higher −/+ cAMP activity ratio, suggesting the existence of other cAMP binding activities. Consequently, three proteins analogous topkaR1were predicted from the recently sequenced genome ofM. circinelloidesand were namedpkaR2,pkaR3, andpkaR4. Two of the proteins,pkaR2andpkaR3, with cAMP binding activity were isolated from the wild-type strain and identified by mass spectrometry. The expression of all genes was detected at the mRNA level by semiquantitative reverse transcription-PCR, and they showed a differential expression at different developmental stages. This is the first time that a fungus is reported to have more than one gene encoding the regulatory subunit of PKA.
Class III Chitin Synthase ChsB of
Aspergillus nidulans
Localizes at the Sites of Polarized Cell Wall Synthesis and Is Required for Conidial Development
Authors: Fukuda Kazuharu , Yamada Kazunari , Deoka Ken , Yamashita Shuichi , Ohta Akinori , Horiuchi Hiroyuki
Published: May 2009

Class III chitin synthases play important roles in tip growth and conidiation in many filamentous fungi. However, little is known about their functions in those processes. To address these issues, we characterized the deletion mutant of a class III chitin synthase-encoding gene of
Aspergillus nidulans
,
chsB
, and investigated ChsB localization in the hyphae and conidiophores. Multilayered cell walls and intrahyphal hyphae were observed in the hyphae of the
chsB
deletion mutant, and wavy septa were also occasionally observed. ChsB tagged with FLAG or enhanced green fluorescent protein (EGFP) localized mainly at the tips of germ tubes, hyphal tips, and forming septa during hyphal growth. EGFP-ChsB predominantly localized at polarized growth sites and between vesicles and metulae, between metulae and phialides, and between phalides and conidia in asexual development. These results strongly suggest that ChsB functions in the formation of normal cell walls of hyphae, as well as in conidiophore and conidia development in
A. nidulans
.
The Global Consequence of Disruption of the AcrAB-TolC Efflux Pump in
Salmonella enterica
Includes Reduced Expression of SPI-1 and Other Attributes Required To Infect the Host
Authors: Webber Mark A. , Bailey Andrew M. , Blair Jessica M. A. , Morgan Eirwen , Stevens Mark P. , Hinton Jay C. D. , Ivens Al , Wain John , Piddock Laura J. V.
Published: May 2009

The mechanisms by which RND pumps contribute to pathogenicity are currently not understood. Using the AcrAB-TolC system as a paradigm multidrug-resistant efflux pump and
Salmonella enterica
serovar Typhimurium as a model pathogen, we have demonstrated that AcrA, AcrB, and TolC are each required for efficient adhesion to and invasion of epithelial cells and macrophages by
Salmonella
in vitro. In addition, AcrB and TolC are necessary for
Salmonella
to colonize poultry. Mutants lacking
acrA
,
acrB
, or
tolC
showed differential expression of major operons and proteins involved in pathogenesis. These included chemotaxis and motility genes, including
cheWY
and
flgLMK
and 14
Salmonella
pathogenicity island (SPI)-1-encoded type III secretion system genes, including
sopE
, and associated effector proteins. Reverse transcription-PCR confirmed these data for identical mutants in two other
S.
Typhimurium backgrounds. Western blotting showed reduced production of SipA, SipB, and SipC. The absence of AcrB or TolC also caused widespread repression of chemotaxis and motility genes in these mutants, and for
acrB
::
aph
, this was associated with decreased motility. For mutants lacking a functional
acrA
or
acrB
gene, the
nap
and
nir
operons were repressed, and both mutants grew poorly in anaerobic conditions. All phenotypes were restored to that of the wild type by
trans
-complementation with the wild-type allele of the respective inactivated gene. These data explain how mutants lacking a component of AcrAB-TolC are attenuated and that this phenotype is a result of decreased expression of numerous genes encoding proteins involved in pathogenicity. The link between antibiotic resistance and pathogenicity establishes the AcrAB-TolC system as fundamental to the biology of
Salmonella
.
TheCoxiella burnetiiAnkyrin Repeat Domain-Containing Protein Family Is Heterogeneous, with C-Terminal Truncations That Influence Dot/Icm-Mediated Secretion
Authors: Voth Daniel E. , Howe Dale , Beare Paul A. , Vogel Joseph P. , Unsworth Nathan , Samuel James E. , Heinzen Robert A.
Published: May 2009

Coxiella burnetiiis an obligate intracellular bacterium that directs biogenesis of a parasitophorous vacuole (PV) for replication. Effectors of PV maturation are likely translocated into the host cytosol by a type IV secretion system (T4SS) with homology to the Dot/Icm apparatus ofLegionella pneumophila. Since secreted bacterial virulence factors often functionally mimic the activities of host proteins, prokaryotic proteins with eukaryotic features are considered candidate T4SS substrates. Genes encoding proteins with eukaryotic-type ankyrin repeat domains (Anks) were identified upon genome sequencing of theC. burnetiiNine Mile reference isolate, which is associated with a case of human acute Q fever. Interestingly, recent genome sequencing of the G and K isolates, derived from human chronic endocarditis patients, and of the Dugway rodent isolate revealed remarkable heterogeneity in the Ank gene family, with the Dugway isolate harboring the largest number of full-length Ank genes. UsingL. pneumophilaas a surrogate host, we identified 10 Dugway Anks and 1 Ank specific to the G and K endocarditis isolates translocated into the host cytosol in a Dot/Icm-dependent fashion. A 10-amino-acid C-terminal region appeared to be necessary for translocation, with some Anks also requiring the chaperone IcmS for secretion. Ectopically expressed Anks localized to a variety of subcellular regions in mammalian cells, including microtubules, mitochondria, and the PV membrane. Collectively, these data suggest thatC. burnetiiisolates translocate distinct subsets of the Ank protein family into the host cytosol, where they modulate diverse functions, some of which may be unique toC. burnetiipathotypes.
Ion Diffusion and Lithium Jump of Li2B12F12 dissolved in Propylene Carbonate (PC) studied by NMR Spectroscopy
Authors: Hayamizu Kikuko , Hattori Mineyuki , Arai Juichi , Matsuo Akira
Published: May 2009

Many lithium salts are investigated to use in electrolytes for lithium batteries. Most anions are monovalent ions. A newly synthesized cluster bivalent anion B12F122- has been verified on the possibility of the usage in secondary lithium batteries. In this study, diffusive properties of the anion, lithium and solvent are studied by the PGSE NMR method for four different concentrations of the PC solutions. Since the temperature dependence of 7Li T1 shows the minimum, the correlation times for the lithium jump are estimated.
Electrochemical and Physicochemical Properties of PYR14-FSI Based Electrolytes with LiFSI
Authors: Paillard Elie E. , Zhou Qian , Henderson Wesley , Appetecchi Giovanni B. , Montanino Maria , Passerini Stefano
Published: May 2009

N-methyl-N-butylpyrrolidinium bis(fluorosulfonyl)imide ionic liquid (PY14FSI)-based electrolytes with LiFSI have been characterized in terms of conductivity, viscosity, thermal phase behavior, electrochemical and thermal stability. The results indicate a high conductivity for the pure ionic liquid and those containing LiFSI. The addition of salt lowers the melting temperature of the electrolyte mixture and, for some of the electrolytes, the conductivity is superior to 10-5 S cm-1 at -40{degree sign}C and up to 3.7 mS cm-1 at 25{degree sign}C. For the more conductive electrolyte at room temperature ((1-x) PY14FSI-(x) LiFSI (x = 0.10)), lithium metal has been cycled for more than 200 cycles at 20{degree sign}C with little overpotential relative to the Li0/Li+ couple, showing that the passivation layer on the surface of lithium is stable and allows reversible lithium deposition. One drawback of these electrolytes is the low thermal degradation temperature, which is lower than that of the pure IL, which may be attributed to impurities in the commercially available LiFSI.
Lithium-ion Kinetics at Interface between Lithium-ion Conductive Electrolyte/DMC-based Electrolyte Interfaces
Authors: Yamada Yuki , Abe T. , Ogumi Zempachi
Published: May 2009

Lithium-ion transfer at interface between lithium-ion conductive ceramic of La0.55Li0.35TiO3 (LLT) and liquid electrolyte consisting of LiClO4 and mixture of EC and DMC (1:9 in vol%) was studied by AC impedance spectroscopy using a four-probe cell. From the Nyquist plot, the resistance due to the lithium-ion transfer at interface between LLT and liquid electrolyte was obtained. The temperature dependency of the charge transfer resistances gave the activation energies of around 53 kJmol-1, which is almost identical with the value for the lithium-ion transfer using the same system except that the volume ratio of EC and DMC is 1:1. In contrast, when the liquid electrolyte consisting of LiClO4 and DMC was used, the activation energy was evaluated to be 33 kJmol-1. Lithium-ion kinetics at the interface was discussed.
Role of cGMP-dependent protein kinase in regulation of pulmonary vascular smooth muscle cell adhesion and migration: effect of hypoxia
Authors: Negash S. , Narasimhan S. R. , Zhou W. , Liu J. , Wei F. L. , Tian J. , Raj J. Usha
Published: May 2009

Exposure to prolonged hypoxia can result in pulmonary vascular remodeling and pulmonary hypertension. Hypoxia induces pulmonary vascular smooth muscle cell (PVSMC) proliferation and vascular remodeling by affecting cell adhesion and migration and secretion of extracellular matrix proteins. We previously showed that acute hypoxia decreases cGMP-dependent protein kinase (PKG) activity in PVSMC and that PKG plays a role in maintaining the differentiated contractile phenotype in normoxia. In this study, we investigated the effect of hypoxia on PVSMC adhesion and migration and the role of PKG in these functions. Ovine fetal pulmonary artery SMC were incubated in normoxia (Po2∼100 Torr) or hypoxia (Po2∼30–40 Torr) or treated with the PKG inhibitor DT-3 for 24 h in normoxia. To further study the role of PKG in the modulation of adhesion and migration, PVSMC were transiently transfected with a full-length PKG1α [PKG-green fluorescent protein (GFP)] or a dominant-negative construct (G1αR-GFP). Cell adhesion to extracellular matrix proteins was determined, and integrin-mediated adhesion was assessed by α/β-integrin-mediated cell adhesion array. Exposure to hypoxia (24 h) and pharmacological inhibition of PKG1 by DT-3 significantly promoted adhesion mediated by α4-, β1-, and α5β1-integrins to fibronectin, laminin, and tenacin and also resulted in increased cell migration. Likewise, inhibition of PKG by expression of a dominant-negative PKG1α construct increased cell adhesion and migration, comparable to that induced by hypoxia. Dynamic actin reorganization associated with integrin-mediated cell adhesion is partly regulated by the actin-binding protein cofilin, the (Ser3) phosphorylation of which inhibits its actin-severing activity. We found that increased PKG expression and activity is associated with decreased cofilin (Ser3) phosphorylation, implying a role for PKG in the modulation of cofilin activity and actin dynamics. Together, these findings identify cGMP/PKG1 signaling as central to the functional differences between PVSMC exposed to normoxia versus hypoxia.
Lipid-soluble components in cigarette smoke induce mitochondrial production of reactive oxygen species in lung epithelial cells
Authors: van der Toorn Marco , Rezayat Delaram , Kauffman Henk F. , Bakker Stephan J. L. , Gans Rijk O. B. , Koëter Gerard H. , Choi Augustine M. K. , van Oosterhout Antoon J. M. , Slebos Dirk-Jan
Published: May 2009

Reactive oxygen species (ROS) present in cigarette smoke (CS) are thought to contribute to the development of COPD. Although CS-ROS can hardly enter airway epithelial cells, and certainly not the circulation, systemic levels of ROS have been found to be elevated in COPD patients. We hypothesize that lipophilic components present in CS can enter airway epithelial cells and increase intracellular ROS production by disturbing mitochondrial function. Different airway epithelial cells were exposed to CS extract (CSE), hexane-treated CSE (CSE without lipophilic components), gaseous-phase CS, and water-filtered CS (gaseous-phase CS without ROS). Mitochondrial membrane potential (Δψm) and ATP levels were assessed using the bronchial epithelial cell line Beas-2b. ROS generation measured directly by DCF fluorescence and indirectly by measuring free thiol groups (-SH) upon exposure to CS was assessed using lung alveolar epithelial cells devoid of functional mitochondria (A549-ρ0), with normal A549 cells serving as controls. In Beas-2b cells, CSE (4 h) caused a dose-dependent decrease in Δψm and ATP levels, whereas hexane-treated CSE did not. DCF fluorescence in A549 cells increased in response to CSE, whereas this was not the case in A549-ρ0 cells. Exposure of A549 cells to CS resulted in a rapid decrease in free -SH, whereas exposure to ROS-depleted CS only resulted in a delayed decrease. This delayed decrease was less pronounced in A549-ρ0 cells. Lipophilic components in CS disturb mitochondrial function, which contributes to increased intracellular generation of ROS. Our results are of importance in understanding the systemic effects of smoking observed in patients with COPD.
Aberrant cell adhesion molecule expression in human bronchopulmonary sequestration and congenital cystic adenomatoid malformation
Authors: Volpe MaryAnn V. , Chung Eunice , Ulm Jason P. , Gilchrist Brian F. , Ralston Steven , Wang Karen T. , Nielsen Heber C.
Published: May 2009

In many organs, integrins and cadherins are partly regulated by Hox genes, but their interactions in airway morphogenesis and congenital lung diseases are unknown. We previously showed that the Hox protein HoxB5 is abnormally increased in bronchopulmonary sequestration (BPS) and congenital cystic adenomatoid malformation (CCAM), congenital lung lesions with abnormal airway branching. We now report on α2-, α3-, and β1-integrin and E-cadherin expression in normal human lung and in BPS and CCAM tissue previously shown to have abnormal HoxB5 expression and on the relationship of cell adhesion molecule expression to Hoxb5 regulation. α2-, α3-, and β1-integrins and E-cadherin expression in normal human lung and BPS and CCAM were evaluated using Western blot and immunohistochemistry. Fetal mouse lung fibroblasts with Hoxb5-specific siRNA downregulation were evaluated for α2-integrin protein levels by Western blot. Compared with normal human lung, a previously undetected α2-integrin isoform potentially lacking essential cytoplasmic sequences was significantly increased in BPS and CCAM, and α2-integrin spatial and cellular expression was more intense. E-cadherin protein levels were also significantly increased, whereas α3increased in CCAM compared with canalicular, but not with alveolar, stage lung. β1-integrin levels were unchanged. We conclude that in BPS and CCAM, altered α2-integrin cytoplasmic signaling contributes to abnormal cellular behavior in these lung lesions. Aberrant cell adhesion molecule and Hox protein regulation are likely part of the mechanism involved in the development of BPS and CCAM.
Decoding the Ternary (23, 11, 9) Quadratic Residue Code
Authors: Interlando J. Carmelo
Published: May 2009

The algebraic decoding of binary quadratic residue codes can be performed using the Peterson or the Berlekamp‐Massey algorithm once certain unknown syndromes are determined or eliminated. The technique of determining unknown syndromes is applied to the nonbinary case to decode the expurgated ternary quadratic residue code of length 23.
Intra-Skip in Inter-Frame Coding of H.264/AVC
Authors: Su Hui
Published: May 2009

In inter-frame coding of H.264/AVC standard, not only seven inter-partition modes but also intra-modes are taken into account for seeking the best coding mode so as to maintain higher encoding efficiency by sacrificing the speed of H.264/AVC encoder. Aiming at intra-skip, this paper proposes a novel mathematical model for intra-skip in inter-frame coding to alleviate the complexity of the process; the model provides remarkable performance increment by cutting down encoding time while accompanying very minor bitrate increase. The critical advantage of this proposed scheme most emphasized on is that it can optimize H.264 encoder in conjunction with any proposed fast inter- and intra-methods which are focusing on inter-partition mode decision, motion search algorithms, and fast intra-algorithms.
Tumor Necrosis Factor Receptor Superfamily, Member 1B Haplotypes Increase or Decrease the Risk of Inflammatory Bowel Diseases in a New Zealand Caucasian Population
Authors: Ferguson Lynnette R. , Han Dug Yeo , Huebner Claudia , Petermann Ivonne , Barclay Murray L. , Gearry Richard B. , McCulloch Alan , Demmers Pieter S.
Published: May 2009

Inflammatory bowel diseases (IBDs) comprising Crohn disease (CD) and ulcerative colitis (UC) are chronic inflammatory conditions with polygenic susceptibility. Interactions between TNF-alpha and TNF-alpha receptor play a fundamental role in inflammatory response. This study investigates the role that selected single nucleotide polymorphisms (SNPs) and haplotypes in the TNF-alpha receptor (TNSFRSF1B) gene play in the risk of IBD in a New Zealand Caucasian population. DNA samples from 388 CD, 405 UC, 27 indeterminate colitis patients, and 293 randomly selected controls, from Canterbury, New Zealand were screened for 3 common SNPs in TNSFRSF1B: rs1061622 (c.676T>C), rs1061624 (c.∗1663A>G), and rs3397 (c.∗1690T>C), using TaqMan technologies. Carrying the rs1061624 variant decreased the risk of UC in the left colon (OR 0.73, 95% CI=0.54–1.00) and of being a smoker at diagnosis (OR 0.62; 95% CI=0.40–0.96). Carrying the rs3397 variant decreased the risk of penetrating CD (OR 0.62, 95% CI=0.40–0.95). Three marker haplotype analyses revealed highly significant differences between CD patients and control subjects (χ2=29.9,df=7,P=.0001) and UC cases and controls (χ2=46.3,df=7,P<.0001). We conclude that carrying a 3-marker haplotype in the TNSFRSF1B gene may increase (e.g., haplotype of GGC was 2.9-fold more in the CD or UCpatients) or decrease (e.g., TGT was 0.47-fold less in UC patients) the risk of IBD in a New Zealand Caucasian population.
Cannabis and Breastfeeding
Authors: Garry Aurélia , Rigourd Virginie , Amirouche Ammar , Fauroux Valérie , Aubry Sylvie , Serreau Raphaël
Published: May 2009

Cannabis is a drug derived from hemp plant,Cannabis sativa, used both as a recreational drug or as medicine. It is a widespread illegal substance, generally smoked for its hallucinogenic properties. Little is known about the adverse effects of postnatal cannabis exposure throw breastfeeding because of a lack of studies in lactating women. The active substance of cannabis is the delta 9 TetraHydroCannabinol (THC). Some studies conclude that it could decrease motor development of the child at one year of age. Therefore, cannabis use and abuse of other drugs like alcohol, tobacco, or cocaine must be contraindicated during breastfeeding. Mothers who use cannabis must stop breastfeeding, or ask for medical assistance to stop cannabis use in order to provide her baby with all the benefits of human milk.
Improving Accuracy of Coarse Grid Numerical Solution of Solid‐Solid Reactions by Taylor Series Expansion of the Reaction Term
Authors: Hassanzadeh Hassan , Pooladi-Darvish Mehran , Abedi Jalal
Published: May 2009

Exothermic solid‐solid reactions lead to sharp reaction fronts that cannot be captured by coarse spatial mesh size numerical simulations that are often required for large‐scale simulations. We present a coarse‐scale formulation with high accuracy by using a Taylor series expansion of the reaction term. Results show that such expansion could adequately maintain the accuracy of fine‐scale behavior of a constant pattern reaction front while using a smaller number of numerical grid cells. Results for a one‐dimensional solid‐solid reacting system reveal reasonable computational time saving. The presented formulation improves our capabilities for conducting fast and accurate numerical simulations of industrial‐scale solid‐solid reactions.
Fixed Points and Stability of the Cauchy Functional Equation in "Equation missing" -Algebras
Authors: Park Choonkil
Published: May 2009

Using the fixed point method, we prove the generalized Hyers-Ulam stability of homomorphisms in "Equation missing"-algebras and Lie "Equation missing"-algebras and of derivations on "Equation missing"-algebras and Lie "Equation missing"-algebras for the Cauchy functional equation.
Hairy Cell Leukemia and Bladder Cancer in a Patient: Relation with Dye Exposure and Review of the Literaure
Authors: Paydas Semra
Published: May 2009

Chemical exposure is important in the etiology of some cancers. Dye or solvent exposures are important both in bladder cancer (BC) and hairy cell leukemia (HCL). Here a case with BC and HCL has been presented and literature has been reviewed.
Synthesis, Spectroscopic, and Antimicrobial Studies on Bivalent Zinc and Mercury Complexes of 2‐Formylpyridine Thiosemicarbazone
Authors: Chandra Sulekh , Parmar Shikha , Kumar Yatendra
Published: May 2009

A series of metal complexes of Zn(II) and Hg(II) having the general composition [M(L)2]X2 [where L = 2‐formylpyridine thiosemicarbazone; M = Zn(II) and Hg(II); X = Cl−, and ] have been prepared and characterized by elemental chemical analysis, molar conductance, and spectral (IR and mass) studies. The IR spectral data suggests the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, a tetrahedral geometry has been assigned for Zn(II) and Hg(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.
Chemokine Receptor and Ligand Upregulation in the Diaphragm during Endotoxemia and Pseudomonas Lung Infection
Authors: Demoule Alexandre , Divangahi Maziar , Yahiaoui Linda , Danialou Gawiyou , Gvozdic Dusanka , Petrof Basil J.
Published: May 2009

Sepsis-induced diaphragmatic inflammation has been associated with respiratory failure, but the role of chemokines in this process has not been evaluated. Here we sought to study the local expression and molecular regulation of the chemokines, regulated upon activation normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein (MIP)-1α, in the murine diaphragm during sepsis. Constitutive expression levels of RANTES and MIP-1α, as well as their receptors, CCR1 and CCR5, were significantly higher in diaphragm than limb muscle. Sepsis was induced by acute lipopolysaccharide (LPS) delivery or subacutely by intratracheal administration of livePseudomonas aeruginosabacteria. Both sepsis models triggered a marked upregulation of RANTES and MIP-1αin the diaphragm. In vitro, stimulation of diaphragmatic muscle cells with LPS also led to RANTES upregulation. Inhibition of the NF-kB pathway using pharmacologic or dominant negative genetic approaches blocked the LPS-induced RANTES upregulation, while free radical scavengers had no effect. We conclude that sepsis leads to greatly increased expression of RANTES, MIP-1αand their cognate receptors in the diaphragm. Manipulation of the NF-kB pathway and other regulators of chemokine expression in the diaphragm could represent a novel method for mitigating the skeletal muscle inflammatory response associated with sepsis-induced diaphragmatic dysfunction.
Generalized Variational Principle for Long Water‐Wave Equation by He′s Semi‐Inverse Method
Authors: Zhang Weimin
Published: May 2009

Variational principles for nonlinear partial differential equations have come to play an important role in mathematics and physics. However, it is well known that not every nonlinear partial differential equation admits a variational formula. In this paper, He′s semi‐inverse method is used to construct a family of variational principles for the long water‐wave problem.
Prevention of Cardiomyopathy in Transfusion-Dependent Homozygous Thalassaemia Today and the Role of Cardiac Magnetic Resonance Imaging
Authors: Aessopos Athanassios , Berdoukas Vasilios , Tsironi Maria
Published: May 2009

Transfusion and iron chelation therapy revolutionised survival and reduced morbidity in patients with transfusion-dependent beta thalassaemia major. Despite these improvements, cardiac disease remained the most common cause of death in those patients. Recently the ability to determine the degree of cardiac iron overload, through cardiac magnetic resonance imaging (CMR) has allowed more logical approaches to iron removal, particularly from the heart. The availability of two oral chelators, deferiprone and deferasirox has reduced the need for the injectable chelator deferrioxamine and an additional benefit has been that deferiprone has been shown to be more cardioprotective than deferrioxamine. This review on the prevention of cardiac disease makes recommendations on the chelation regime that would be desirable for patients according to their cardiac iron status as determined by CMR determined by CMR. It also discusses approaches to chelation management should CMR not be available.
Limited Stochastic Meta-Descent for Kernel-Based Online Learning
Authors: He Wenwu
Published: May 2009

To improve the single-run performance of online learning and reinforce its stability, we consider online learning with limited adaptive learning rate in this letter. The letter extends convergence proofs for NORMA to a range of step sizes, then employs support vector learning with stochastic meta-descent (SVMD) limited to that range for step size adaptation, so as to obtain an online kernel algorithm that combines theoretical convergence guarantees with good practical performance. Experiments on different data sets corroborate theoretical results well and show that our method is another promising way for online learning.
Stimulus-Dependent Correlations in Threshold-Crossing Spiking Neurons
Authors: Burak Yoram , Lewallen Sam , Sompolinsky Haim
Published: May 2009

We consider a threshold-crossing spiking process as a simple model for the activity within a population of neurons. Assuming that these neurons are driven by a common fluctuating input with gaussian statistics, we evaluate the cross-correlation of spike trains in pairs of model neurons with different thresholds. This correlation function tends to be asymmetric in time, indicating a preference for the neuron with the lower threshold to fire before the one with the higher threshold, even if their inputs are identical. The relationship between these results and spike statistics in other models of neural activity is explored. In particular, we compare our model with an integrate-and-fire model in which the membrane voltage resets following each spike. The qualitative properties of spike cross-correlations, emerging from the threshold-crossing model, are similar to those of bursting events in the integrate-and-fire model. This is particularly true for generalized integrate-and-fire models in which spikes tend to occur in bursts, as observed, for example, in retinal ganglion cells driven by a rapidly fluctuating visual stimulus. The threshold-crossing model thus provides a simple, analytically tractable description of event onsets in these neurons.
Cash for Comment
Authors: Chylinski Mathew
Published: May 2009

An unconditioned stimulus in the form of “participation money” serves to keep track of students’ comments during class discussions and extrinsically to reinforce their class participation behaviors. Using a longitudinal experiment to investigate the effect of the participation money stimulus on several education outcomes, the author finds that the stimulus increases the number of comments during weekly class discussions, as perceived by both instructors and students. This increased class participation has a positive effect on students’ experience and perceived understanding of course material, as well as the social atmosphere during class discussions. The findings thus have important implications for marketing educators.
An Investigation of Factors Associated With Student Participation in Study Abroad
Authors: Doyle Stephanie , Gendall Philip , Meyer Luanna H. , Hoek Janet , Tait Carolyn , McKenzie Lynanne , Loorparg Avatar
Published: May 2009

International student exchange programs are widely promoted in higher education as a means of developing desirable intercultural skills and understanding among students. This multimethod study employed data from student surveys, tertiary institution case studies, and interviews with key stakeholders to identify factors that inhibited or promoted the uptake of international exchange programs among New Zealand students. These factors include the development of early understanding of the benefits of studying abroad; ongoing support to students; social, cultural, and linguistic capabilities; and how effectively overseas study was integrated into student degree programs. Implications of these findings for exchange programs in general are discussed in the context of future strategic development of expanded, more diverse opportunities for study overseas.
Chromosome 7 Aneusomy in Metaplastic Breast Carcinomas With Chondroid, Squamous, and Spindle-Cell Differentiation
Authors: Gwin Katja , Lezon-Geyda Kimberly , Harris Lyndsay , Tavassoli Fattaneh A.
Published: May 2009

Metaplastic breast carcinomas (MBCs) are basal-like tumors that frequently express epidermal growth factor receptor (EGFR) via an unknown underlying genetic mechanism. In this study, the EGFR/CEP7 gene copy number in 17 MBCs with chondroid, squamous, and spindle-cell differentiation showing EGFR expression by immunohistochemistry was analyzed using fluorescence in situ hybridization. All cases had a balanced EGFR/CEP7 ratio. EGFR gene amplification was not observed in any case. Monosomy was found in 25% and polysomy in 12.5% of carcinomas with chondroid differentiation. All spindle-cell carcinomas and 50% of squamous carcinomas showed trisomy. Comparison with CEP7 copy number revealed aneusomy of chromosome 7, as opposed to increases or decreases specific to the EGFR gene or 7p. Although no direct correlation between EGFR expression by immunohistochemistry and aneusomy was observed, cases with a score of 3+ showed a higher frequency of EGFR gene copy gain. In the absence of EGFR amplification, chromosome 7 aneusomy might be a useful criterion for the determination of potential candidates for EGFR tyrosine kinase inhibitor clinical trials.
Writing Our Way Into Shared Understanding
Authors: Lapadat Judith C.
Published: May 2009

From her experience as an instructor, the author finds that it is valuable to engage graduate students in conducting a study within their qualitative methods course. In this article, the author discusses how she used a collaborative autobiographical research approach. Class members generate autobiographical writing to be shared with the group, and then the group collaboratively analyzes and interprets the set of autobiographical materials. The author goes on to describe two examples of collaborative autobiographical projects grounded, respectively, in memory-work and narrative inquiry frameworks. The complexity of autobiographical writing and the value of collaboration are discussed, along with ethical issues relating to role blurring, coresearcher relationships, anonymity, Research Ethics Board timelines, and cycles of consent.
Generation of a Danish TTO value set for EQ-5D health states
Authors: Wittrup-Jensen Kim U. , Lauridsen Jørgen , Gudex Claire , Pedersen Kjeld M.
Published: May 2009

Aims: Health policy decisions should be based on national social preferences. In the absence of a set of Danish health preferences, patient outcome studies using the EQ-5D instrument have typically used UK health state valuations. This article describes the development of a Danish EQ-5D value set. Methods: Regression modelling was based on Time Trade-Off (TTO) data derived from computer-assisted interviews conducted with 1,332 respondents from the Danish general population. Using a split-sample technique, 46 health states were directly valued by the respondents. Five different model types were tested and compared on statistical and theoretical grounds. Eleven different specifications were then tested for the chosen model type to identify the most appropriate model that had high explanatory power and parameters that were both consistent (positively signed) and statistically significant. Results: An additive random effects model was found to be superior to ordinary least squares, fixed effects, random coefficient and censored Tobit modelling approaches. From the 11 model specifications tested, the TTO3 model (main effects model, without an N3 factor) performed best and was used to generate a Danish set of health state preferences. Conclusions: An additive random effects model appears to adequately generate a Danish set of EQ-5D health state preferences. The model has high explanatory power and produces consistent and significant parameters for EQ-5D dimensions and levels. It is recommended that this value set be used in Danish cost-utility studies using EQ-5D.
Hemisphere Specific Impairments in Reach-to-Grasp Control After Stroke: Effects of Object Size
Authors: Tretriluxana Jarugool , Gordon James , Fisher Beth E. , Winstein Carolee J.
Published: May 2009

Background and objective. The authors investigated hemispheric specialization for the visuomotor transformation of grasp preshaping and the coordination between transport and grasp in individuals poststroke. Based on a bilateral model, the authors hypothesized that after unilateral stroke there would be hemisphere-specific deficits revealed by the ipsilesional limb. Methods. Right or left stroke and age- and limb-matched nondisabled participants performed rapid reach-to-grasp of 3 sized objects. The authors quantified grasp preshaping as the correlation between initial aperture velocity and peak aperture, and peak aperture and object diameter. A cross correlation analysis using transport velocity and aperture size was performed to quantify transport-grasp coordination. All statistical tests for hemisphere-specific deficits involved comparisons between each stroke group and the matched nondisabled group. Results. Overall, the right stroke group, but not left stroke group, demonstrated prolonged movement time. For grasp preshaping there was a higher correlation between initial aperture velocity and peak aperture for the right stroke group and a lower correlation between peak aperture and object diameter for the left stroke group. For transport-grasp coordination the correlation between transport velocity and aperture size was higher for the left stroke group and lower for the right stroke group, which also demonstrated a higher standard deviation of time lag. Conclusions. After left stroke, there was deficient scaling of grasp preshaping and stronger transport-grasp coordination. In contrast, after right stroke, grasp preshaping began earlier and transport-grasp coordination was weaker. Together, these hemisphere-specific deficits suggest a left hemisphere specialization for the visuomotor transformation of grasp preshaping and a right hemisphere specialization for transport-grasp coordination.
Taken on Faith? The Impact of Uncertainty, Knowledge Relatedness, and Richness of Information on Entrepreneurial Opportunity Exploitation
Authors: Wood Matthew S. , Pearson J. Michael
Published: May 2009

This article develops a theoretical model that suggests that differential levels of uncertainty, knowledge relatedness, and richness of information will have a substantial impact on the decision to engage in entrepreneurship. Effects of the individual differences fear of failure and general self-efficacy are also considered. Using a metric conjoint methodology, respondents are asked to evaluate a series of profiles with different levels of each attribute and then indicate their willingness to invest in an entrepreneurial opportunity. This approach allows for the calculation of main and interaction effects as well as the importance of each factor in the investment decision. Results indicated that all three factors and their interactions play a significant role in the decision to engage in entrepreneurial action. The degree of opportunity-related uncertainty was found to be the most important factor in the decision-making process.