bluuebunny/crossref_metadata_2025 huggingface dataset:
Different gvpC length variants are transcribed within single filaments of the cyanobacterium Planktothrix rubescens
Authors: Becker Sven , Hayes Paul K. , Walsby Anthony E.
Published: January 2005

Transcripts of the gas vesicle genesgvpAandgvpCwere detected in single filaments of the cyanobacteriumPlanktothrix rubescensusing reverse transcription and quantitative real-time PCR. Primers were designed to amplify short sequences withingvpAand three length variants ofgvpC. With genomic template DNA, and using Sybr Green to monitor product accumulation, similar amplification efficiencies were observed for each of these genes. The relative copy numbers ofgvpClength variants in genomic DNA from fivePlanktothrixgas vesicle genotypes determined by real-time PCR were similar to those indicated by sequencing the gas vesicle gene clusters. The precipitation ofgvpcDNA reverse-transcribed from cellular RNA from single filaments was required before amplification of the gene fragments; without this step it was not possible to detect the accumulation of the expected amplicons by dissociation analysis. Precipitation was also necessary to ensure the generation of product curves that allowed linear regression in an early stage of PCR, a prerequisite for the quantification of low-input cDNA amounts without the need for standard curves. This report shows that differentgvpClength variants are transcribed within singlePlanktothrixfilaments, both from laboratory cultures and from natural samples taken from Lake Zürich. This has implications for the efficiency of buoyancy provision by the possible production of gas vesicles of different strengths within individual cyanobacterial filaments. The hypothesis that post-transcriptional regulation may influence the type of protein (GvpC) present in gas vesicles is presented.
Recovery of an environmental chlamydia strain from activated sludge by co-cultivation with Acanthamoeba sp.
Authors: Collingro Astrid , Poppert Sven , Heinz Eva , Schmitz-Esser Stephan , Essig Andreas , Schweikert Michael , Wagner Michael , Horn Matthias
Published: January 2005

Chlamydiae are a unique group of obligate intracellular bacteria comprising important pathogens of vertebrates as well as symbionts of free-living amoebae. Although there is ample molecular evidence for a huge diversity and wide distribution of chlamydiae in nature, environmental chlamydiae are currently represented by only few isolates. This paper reports the recovery of a novel environmental chlamydia strain from activated sludge by co-cultivation with Acanthamoeba sp. The recovered environmental chlamydia strain UV-7 showed the characteristic morphology of chlamydial developmental stages as revealed by electron microscopy and was identified as a new member of the family Parachlamydiaceae (98·7 % 16S rRNA sequence similarity to Parachlamydia acanthamoebae). Infection studies suggested that Parachlamydia sp. UV-7 is not confined to amoeba hosts but is also able to invade mammalian cells. These findings outline a new straightforward approach to retrieving environmental chlamydiae from nature without prior, tedious isolation and cultivation of their natural host cells, and lend further support to suggested implications of environmental chlamydiae for public health.
Degradation of the xenoestrogen nonylphenol by aquatic fungi and their laccases
Authors: Junghanns Charles , Moeder Monika , Krauss Gudrun , Martin Claudia , Schlosser Dietmar
Published: January 2005

Degradation of technical nonylphenol (t-NP), known as an endocrine-disrupting compound mixture, was assessed, using the mitosporic fungal strain UHH 1-6-18-4 isolated from nonylphenol-contaminated river water, and a strain of the aquatic hyphomyceteClavariopsis aquatica. GC-MS analysis could resolve 12 peaks attributable to nonyl chain-branched t-NP isomers. All were degraded, to individual extents. Analysis of degradation metabolites suggested intracellular hydroxylation of the nonyl moieties of individual t-NP isomers. Further metabolites also indicated shortening of branched nonyl chains, and 4-hydroxybenzoic acid was identified as a t-NP breakdown product in UHH 1-6-18-4. The t-NP degradation efficiency was higher in UHH 1-6-18-4 than inC. aquatica, and a lower specificity in degradation of individual t-NP constituents in UHH 1-6-18-4 than inC. aquaticawas observed. Strain UHH 1-6-18-4 concomitantly produced extracellular laccase under degradation conditions. A mixture of CuSO4and vanillic acid considerably enhanced laccase production in both fungi. Laccase preparations derived from UHH 1-6-18-4 andC. aquaticacultures also converted t-NP. Laccase-catalysed transformation of t-NP led to the formation of products with higher molecular masses than that of the parent compound. These results emphasize a role of fungi occurring in aquatic ecosystems in degradation of water contaminants with endocrine activity, which has not previously been considered. Furthermore, the results are in support of two different mechanisms employed by fungi isolated from aquatic environments to initiate t-NP degradation: hydroxylation of individual t-NP isomers at their branched nonyl chains and further breakdown of the alkyl chains of certain isomers; and attack of t-NP by extracellular laccase, the latter leading to oxidative coupling of primary radical products to compounds with higher molecular masses.
Detailed studies of the binding mechanism of the Sinorhizobium meliloti transcriptional activator ExpG to DNA
Authors: Baumgarth Birgit , Bartels Frank Wilco , Anselmetti Dario , Becker Anke , Ros Robert
Published: January 2005

The exopolysaccharide galactoglucan promotes the establishment of symbiosis between the nitrogen-fixing Gram-negative soil bacterium Sinorhizobium meliloti 2011 and its host plant alfalfa. The transcriptional regulator ExpG activates expression of galactoglucan biosynthesis genes by direct binding to the expA1, expG/expD1 and expE1 promoter regions. ExpG is a member of the MarR family of regulatory proteins. Analysis of target sequences of an ExpG(His)6 fusion protein in the exp promoter regions resulted in the identification of a binding site composed of a conserved palindromic region and two associated sequence motifs. Association and dissociation kinetics of the specific binding of ExpG(His)6 to this binding site were characterized by standard biochemical methods and by single-molecule spectroscopy based on the atomic force microscope (AFM). Dynamic force spectroscopy indicated a distinct difference in the kinetics between the wild-type binding sequence and two mutated binding sites, leading to a closer understanding of the ExpG–DNA interaction.
Characterization of new DsbB-like thiol-oxidoreductases of Campylobacter jejuni and Helicobacter pylori and classification of the DsbB family based on phylogenomic, structural and functional criteria
Authors: Raczko Anna M. , Bujnicki Janusz M. , Pawłowski Marcin , Godlewska Renata , Lewandowska Magdalena , Jagusztyn-Krynicka Elżbieta K.
Published: January 2005

In Gram-negative bacterial cells, disulfide bond formation occurs in the oxidative environment of the periplasm and is catalysed by Dsb (disulfide bond) proteins found in the periplasm and in the inner membrane. In this report the identification of a new subfamily of disulfide oxidoreductases encoded by a gene denoted dsbI, and functional characterization of DsbI proteins from Campylobacter jejuni and Helicobacter pylori, as well as DsbB from C. jejuni, are described. The N-terminal domain of DsbI is related to DsbB proteins and comprises five predicted transmembrane segments, while the C-terminal domain is predicted to locate to the periplasm and to fold into a β-propeller structure. The dsbI gene is co-transcribed with a small ORF designated dba (
dsbI-accessory). Based on a series of deletion and complementation experiments it is proposed that DsbB can complement the lack of DsbI but not the converse. In the presence of DsbB, the activity of DsbI was undetectable, hence it probably acts only on a subset of possible substrates of DsbB. To reconstruct the principal events in the evolution of DsbB and DsbI proteins, sequences of all their homologues identifiable in databases were analysed. In the course of this study, previously undetected variations on the common thiol-oxidoreductase theme were identified, such as development of an additional transmembrane helix and loss or migration of the second pair of Cys residues between two distinct periplasmic loops. In conjunction with the experimental characterization of two members of the DsbI lineage, this analysis has resulted in the first comprehensive classification of the DsbB/DsbI family based on structural, functional and evolutionary criteria.
In vivo analyses of constitutive and regulated promoters in halophilic archaea
Authors: Gregor Dagmar , Pfeifer Felicitas
Published: January 2005

The two gvpA promoters PcA
and PpA
of Halobacterium salinarum, and the PmcA
promoter of Haloferax mediterranei were investigated with respect to growth-phase-dependent expression and regulation in Haloferax volcanii transformants using the bgaH reading frame encoding BgaH, an enzyme with β-galactosidase activity, as reporter. For comparison, the Pfdx
promoter of the ferredoxin gene of Hbt. salinarum and the PbgaH
promoter of Haloferax lucentense (formerly Haloferax alicantei) were analysed. Pfdx
, driving the expression of a house-keeping gene, was highly active during the exponential growth phase, whereas PbgaH
and the three gvpA promoters yielded the largest activities during the stationary growth phase. Compared to Pfdx
, the basal promoter activities of PpA
and PmcA
were rather low, and larger activities were only detected in the presence of the endogenous transcriptional activator protein GvpE. The PcA
promoter does not yield a detectable basal promoter activity and is only active in the presence of the homologous cGvpE. To investigate whether the PcA
-TATA box and the BRE element were the reason for the lack of the basal PcA
activity, these elements and also sequences further upstream were substituted with the respective sequences of the stronger PpA
promoter and investigated in Hfx. volcanii transformants. All these promoter chimera did not yield a detectable basal promoter activity. However, whenever the PpA
-BRE element was substituted for the PcA
-BRE, an enhanced cGvpE-mediated activation was observed. The promoter chimeras harbouring PpA
-BRE plus 5 (or more) bp further upstream also gained activation by the heterologous pGvpE and mcGvpE proteins. The sequence required for the GvpE-mediated activation was determined by a 4 bp scanning mutagenesis with the 45 bp region upstream of PmcA
-BRE. None of these alterations influenced the basal promoter activity, but the sequence TGAAACGG-n4-TGAACCAA was important for the GvpE-mediated activation of PmcA
.
The amoebae plate test implicates a paralogue of lpxB in the interaction of Legionella pneumophila with Acanthamoeba castellanii
Authors: Albers Urs , Reus Katrin , Shuman Howard A. , Hilbi Hubert
Published: January 2005

Legionella pneumophilais a bacterial parasite of freshwater amoebae which also grows in alveolar macrophages and thus causes the potentially fatal pneumonia Legionnaires' disease. Intracellular growth within amoebae and macrophages is mechanistically similar and requires the Icm/Dot type IV secretion system. This paper reports the development of an assay, the amoebae plate test (APT), to analyse growth ofL. pneumophilawild-type andicm/dotmutant strains spotted on agar plates in the presence ofAcanthamoeba castellanii. In the APT, wild-typeL. pneumophilaformed robust colonies even at high dilutions,icmT, -R, -PordotBmutants failed to grow, andicmSor -Gmutants were partially growth defective. TheicmSoricmGmutant strains were used to screen anL. pneumophilachromosomal library for genes that suppress the growth defect in the presence of the amoebae. AnicmSsuppressor plasmid was isolated that harboured theicmSand flankingicmgenes, indicating that this plasmid complements the intracellular growth defect of the mutant. In contrast, differenticmGsuppressor plasmids rendered theicmGmutant more cytotoxic forA. castellaniiwithout enhancing intracellular multiplication in amoebae or RAW264.7 macrophages. Deletion of individual genes in the suppressor plasmids inserts identifiedlcs(Legionellacytotoxicsuppressor) -A, -B, -Cand -Das being required for enhanced cytotoxicity of anicmGmutant strain. The corresponding proteins show sequence similarity to hydrolases, NlpD-related metalloproteases, lipid A disaccharide synthases and ABC transporters, respectively. Overexpression of LcsC, a putative paralogue of the lipid A disaccharide synthase LpxB, increased cytotoxicity of anicmGmutant but not that of othericm/dotorrpoSmutant strains againstA. castellanii. Based on sequence comparison and chromosomal location,lcsBandlcsCprobably encode enzymes involved in cell wall maintenance and peptidoglycan metabolism. The APT established here may prove useful to identify other bacterial factors relevant for interactions with amoeba hosts.
Identification of polymorphic motifs using probabilistic search algorithms
Authors: Basu Analabha , Chaudhuri Probal , Majumder Partha P.
Published: January 2005

The problem of identifying motifs comprising nucleotides at a set of polymorphic DNA sites, not necessarily contiguous, arises in many human genetic problems. However, when the sites are not contiguous, no efficient algorithm exists for polymorphic motif identification. A search based on complete enumeration is computationally inefficient. We have developed probabilistic search algorithms to discover motifs of known or unknown lengths. We have developed statistical tests of significance for assessing a motif discovery, and a statistical criterion for simultaneously estimating motif length and discovering it. We have tested these algorithms on various synthetic data sets and have shown that they are very efficient, in the sense that the “true” motifs can be detected in the vast majority of replications and in a small number of iterations. Additionally, we have applied them to some real data sets and have shown that they are able to identify known motifs. In certain applications, it is pertinent to find motifs that contain contrasting nucleotides at the sites included in the motif (e.g., motifs identified in case-control association studies). For this, we have suggested appropriate modifications. Using simulations, we have discovered that the success rate of identification of the correct motif is high in case-control studies except when relative risks are small. Our analyses of evolutionary data sets resulted in the identification of some motifs that appear to have important implications on human evolutionary inference. These algorithms can easily be implemented to discover motifs from multilocus genotype data by simple numerical recoding of genotypes.
Single haplotype analysis demonstrates rapid evolution of the killer immunoglobulin-like receptor (KIR) loci in primates
Authors: Sambrook Jennifer G. , Bashirova Arman , Palmer Sophie , Sims Sarah , Trowsdale John , Abi-Rached Laurent , Parham Peter , Carrington Mary , Beck Stephan
Published: January 2005

The human killer immunoglobulin-like receptors (KIR) are encoded within the Leukocyte Receptor Complex (LRC) on chromosome 19q13.4. Here we report the comparative genomic analysis of single KIR haplotypes in two other primates. In the common chimpanzee (Pan troglodytes), seven KIR genes (ptKIRnewI, ptKIRnewII, ptKIR2DL5, ptKIRnewIII, ptKIR3DP1, ptKIR2DL4, ptKIR3DL1/2) have been identified, and five KIR genes (mmKIRnewI, mmKIR1D, mmKIR2DL4, mmKIR3DL10, mmKIR3DL1) are present in the haplotype sequenced for the rhesus macaque (Macaca mulatta). Additional cDNA analysis confirms the genes predicted from the genomic sequence and reveals the presence of a fifth novel KIR gene (mmKIRnewII) in the second haplotype of the rhesus macaque. While all known human haplotypes contain both activating and inhibitory KIR genes, only inhibitory KIR genes (characterized by long cytoplasmic tails) were found by in silico and cDNA analyses in the two primate haplotypes studied here. Comparison of the two human and the two non-human primate haplotypes demonstrates rapid diversification of the KIR gene family members, many of which have diverged in a species-specific manner. An analysis of the intronic regions of the two non-human primates reveals the presence of ancient repeat elements, which are indicative of the duplication events that have taken place since the last common ancestor.
Linkage group selection: Rapid gene discovery in malaria parasites
Authors: Culleton Richard , Martinelli Axel , Hunt Paul , Carter Richard
Published: January 2005

The identification of parasite genes controlling phenotypes such as drug resistance, virulence, immunogenicity, and transmission is vital to malaria research. Classical genetic methods have achieved these goals only rarely and with difficulty. We describe here a novel genetic method, Linkage Group Selection (LGS), which achieves rapid de novo location of genes encoding selectable phenotypes of malaria parasites. A phenotype-specific selection pressure is applied to the uncloned progeny of a genetic cross between two malaria parasites that differ in the relevant phenotype. Selected and unselected progeny are analyzed using genome-wide quantitative genetic markers. Markers of the “sensitive” parent, which are reduced after selection, are sequenced and located in genomic databases. They are expected to be closely linked to gene(s) determining the phenotype under selection. We have validated LGS with the rodent malaria parasite Plasmodium chabaudi chabaudi using a phenotype, pyrimethamine resistance, whose controlling gene, that encoding dihydrofolate reductase (dhfr), is known. We show that molecular markers closely linked to dhfr, and only those linked to this gene, were reduced or removed by pyrimethamine treatment in accordance with the expectations of LGS.
Gene and alternative splicing annotation with AIR
Authors: Florea Liliana , Di Francesco Valentina , Miller Jason , Turner Russell , Yao Alison , Harris Michael , Walenz Brian , Mobarry Clark , Merkulov Gennady V. , Charlab Rosane , Dew Ian , Deng Zuoming , Istrail Sorin , Li Peter , Sutton Granger
Published: January 2005

Designing effective and accurate tools for identifying the functional and structural elements in a genome remains at the frontier of genome annotation owing to incompleteness and inaccuracy of the data, limitations in the computational models, and shifting paradigms in genomics, such as alternative splicing. We present a methodology for the automated annotation of genes and their alternatively spliced mRNA transcripts based on existing cDNA and protein sequence evidence from the same species or projected from a related species using syntenic mapping information. At the core of the method is the splice graph, a compact representation of a gene, its exons, introns, and alternatively spliced isoforms. The putative transcripts are enumerated from the graph and assigned confidence scores based on the strength of sequence evidence, and a subset of the high-scoring candidates are selected and promoted into the annotation. The method is highly selective, eliminating the unlikely candidates while retaining 98% of the high-quality mRNA evidence in well-formed transcripts, and produces annotation that is measurably more accurate than some evidence-based gene sets. The process is fast, accurate, and fully automated, and combines the traditionally distinct gene annotation and alternative splicing detection processes in a comprehensive and systematic way, thus considerably aiding in the ensuing manual curation efforts.
Evolution and functional classification of vertebrate gene deserts
Authors: Ovcharenko Ivan , Loots Gabriela G. , Nobrega Marcelo A. , Hardison Ross C. , Miller Webb , Stubbs Lisa
Published: January 2005

Large tracts of the human genome, known as gene deserts, are devoid of protein-coding genes. Dichotomy in their level of conservation with chicken separates these regions into two distinct categories, stable and variable. The separation is not caused by differences in rates of neutral evolution but instead appears to be related to different biological functions of stable and variable gene deserts in the human genome. Gene Ontology categories of the adjacent genes are strongly biased toward transcriptional regulation and development for the stable gene deserts, and toward distinctively different functions for the variable gene deserts. Stable gene deserts resist chromosomal rearrangements and appear to harbor multiple distant regulatory elements physically linked to their neighboring genes, with the linearity of conservation invariant throughout vertebrate evolution.
Uprobe: A genome-wide universal probe resource for comparative physical mapping in vertebrates
Authors: Kellner Wendy A. , Sullivan Robert T. , Carlson Brian H. , Thomas James W.
Published: January 2005

Interspecies comparisons are important for deciphering the functional content and evolution of genomes. The expansive array of >70 public vertebrate genomic bacterial artificial chromosome (BAC) libraries can provide a means of comparative mapping, sequencing, and functional analysis of targeted chromosomal segments that is independent and complementary to whole-genome sequencing. However, at the present time, no complementary resource exists for the efficient targeted physical mapping of the majority of these BAC libraries. Universal overgo-hybridization probes, designed from regions of sequenced genomes that are highly conserved between species, have been demonstrated to be an effective resource for the isolation of orthologous regions from multiple BAC libraries in parallel. Here we report the application of the universal probe design principal across entire genomes, and the subsequent creation of a complementary probe resource, Uprobe, for screening vertebrate BAC libraries. Uprobe currently consists of whole-genome sets of universal overgo-hybridization probes designed for screening mammalian or avian/reptilian libraries. Retrospective analysis, experimental validation of the probe design process on a panel of representative BAC libraries, and estimates of probe coverage across the genome indicate that the majority of all eutherian and avian/reptilian genes or regions of interest can be isolated using Uprobe. Future implementation of the universal probe design strategy will be used to create an expanded number of whole-genome probe sets that will encompass all vertebrate genomes.
High-resolution mtDNA evidence for the late-glacial resettlement of Europe from an Iberian refugium
Authors: Pereira Luísa , Richards Martin , Goios Ana , Alonso Antonio , Albarrán Cristina , Garcia Oscar , Behar Doron M. , Gölge Mukaddes , Hatina Jiři , Al-Gazali Lihadh , Bradley Daniel G. , Macaulay Vincent , Amorim António
Published: January 2005

The advent of complete mitochondrial DNA (mtDNA) sequence data has ushered in a new phase of human evolutionary studies. Even quite limited volumes of complete mtDNA sequence data can now be used to identify the critical polymorphisms that define sub-clades within an mtDNA haplogroup, providing a springboard for large-scale high-resolution screening of human mtDNAs. This strategy has in the past been applied to mtDNA haplogroup V, which represents <5% of European mtDNAs. Here we adopted a similar approach to haplogroup H, by far the most common European haplogroup, which at lower resolution displayed a rather uninformative frequency distribution within Europe. Using polymorphism information derived from the growing complete mtDNA sequence database, we sequenced 1580 base pairs of targeted coding-region segments of the mtDNA genome in 649 individuals harboring mtDNA haplogroup H from populations throughout Europe, the Caucasus, and the Near East. The enhanced genealogical resolution clearly shows that sub-clades of haplogroup H have highly distinctive geographical distributions. The patterns of frequency and diversity suggest that haplogroup H entered Europe from the Near East ∼20,000–25,000 years ago, around the time of the Last Glacial Maximum (LGM), and some sub-clades re-expanded from an Iberian refugium when the glaciers retreated ∼15,000 years ago. This shows that a large fraction of the maternal ancestry of modern Europeans traces back to the expansion of hunter-gatherer populations at the end of the last Ice Age.
Ultrastructural pathology of prion diseases revisited: brain biopsy studies
Authors: Liberski P. P. , Streichenberger N. , Giraud P. , Soutrenon M. , Meyronnet D. , Sikorska B. , Kopp N.
Published: January 2005

We report here a detailed ultrastructural comparison of brain biopsies from 13 cases of Creutzfeldt‐Jakob disease (CJD) and from one case of fatal familial insomnia (FFI). The latter disease has not heretofore benefited from ultrastructural study. In particular, we searched for tubulovesicular structures (TVS), 35‐nm particles regarded as the only disease‐specific structures at the level of thin‐section electron microscopy. Our material consisted of brain biopsies obtained by open surgery from one FFI case from a new French family, one case of variant CJD (vCJD), nine cases of sporadic CJD (sCJD), two cases of iatrogenic (human growth hormone) CJD and one case of hereditary CJD (Val203Iso). The ultrastructural picture of the cerebral cortex of the FFI patient was virtually indistinguishable from that of CJD. TVS were found, albeit only after prolonged search. Typical spongiform change was observed, consisting of intracellular membrane‐bound vacuoles containing secondary chambers (vacuoles within vacuoles) and amorphous material. Neuronal degeneration was widespread: some processes contained degenerating mitochondria and lysosomal electron‐dense bodies and these met the criteria for neuroaxonal dystrophy. Other processes contained branching cisterns; still others were filled with electron‐dense masses and amorphous vesicles. The overall ultrastructural appearance of variant CJD was similar to that of FFI cerebral cortex, except for a much higher number of cellular processes containing TVS. We detected TVS in the majority of sCJD cases that, in addition to typical spongiform change and robust astrocytic reaction, showed widespread neuritic and synaptic degeneration and autophagic vacuoles. We conclude that TVS are readily found in FFI, vCJD and sCJD and that widespread neuritic degeneration is a part of ultrastructural pathology in prion diseases.
Olig2 expression, GFAP, p53 and 1p loss analysis contribute to glioma subclassification
Authors: Mokhtari K. , Paris S. , Aguirre‐Cruz L. , Privat N. , Crinière E. , Marie Y. , Hauw J.‐J. , Kujas M. , Rowitch D. , Hoang‐Xuan K. , Delattre J.‐Y. , Sanson M.
Published: January 2005

The expression of Olig2, a basic helix–loop–helix (bHLH) transcription factor involved in oligodendroglial specification, was investigated by immunohistochemistry in a series of 146 tumours and control samples. Olig2 expression was restricted to glial tumours and nontumoral oligodendrocytes. It was higher in oligodendrogliomas as compared to astrocytomas and oligoastrocytomas, and in grade III as compared to grade II tumours. Olig 2 was absent or weakly expressed in glioblastoma (GBM), whereas strong expression was found in the oligodendroglial foci of GBM with oligodendroglial component (GBMO). Double labelling was performed on a subset of the most typical tumours, according to the WHO classification. It showed a mutual exclusion, at cell level, of Olig2 and GFAP expression. In pure oligodendrogliomas, tumour cells were Olig2+/GFAP–. In contrast, two main tumour populations, Olig2+/GFAP– and Olig2–/GFAP+, were found in both oligoastrocytomas and astrocytomas. Based on these data from selected samples, two separate entities can be established, corresponding to ‘pure oligodendrogliomas’ and ‘astrocytomas and oligoastrocytomas’. The relevance of this subdivision is further supported by the association with 1p loss and a trend to better survival for pure oligodendrogliomas and with p53 expression and a trend to shorter survival for astrocytomas and oligoastrocytomas. Combined testing of Olig2, 1p status, GFAP and p53 expression may therefore be helpful in refining current classification and providing more homogeneous sets of gliomas for clinical studies.
Genetic–morphologic association study: association between the low density lipoprotein‐receptor related protein (LRP) and cerebral amyloid angiopathy
Authors: Christoforidis M. , Schober R. , Krohn K.
Published: January 2005

Accumulating evidence suggests that genetic factors such as apolipoprotein E (APOE), can act in different ways in the pathogenesis of cerebral amyloid angiopathy (CAA) and Alzheimer's disease (AD). The role of the low‐density lipoprotein‐receptor related protein (LRP), the major cerebral APOE receptor, in AD has been discussed controversially depending on data from different populations and methodological approaches. We examined the influence of LRP polymorphisms on CAA in 125 post‐mortem cases genotyped for APOE and classified according to the neurofibrillary Braak and Braak staging of AD (indicating neurodegeneration grade). CAA was assessed separately for leptomeningeal (CAAlep.), noncapillary cortical (CAAcort.) and capillary cortical (CAAcap.) vessels in β‐amyloid stained sections. Our results suggest: (i) the 87 bp allele of LRP5′ polymorphism (LRP5′) is an independent predictive factor for CAAcort. and CAAlep.; (ii) the C/C genotype (C allele) of the LRP exon 3 polymorphism is positively associated with  the  severity  of  CAAlep.  and  CAAcort.,  implicating a younger age of CAA onset and/or faster CAA progression; (iii) as CAAcort. and CAAlep. showed different genetic associations in contrast to CAAcap., we can underscore the hypothesis that different molecular mechanisms are involved in CAA pathogenesis of noncapillary and capillary cerebral vessels. Our results lead us to postulate that the LRP5′87 bp and the LRP exon 3 C alleles of the LRP gene (or another locus that might be in linkage disequilibrium with these LRP polymorphic sites) could modify cerebrovascular LRP function or expression in noncapillary cerebral vessels, leading to an increased cerebrovascular amyloid deposition.
Personality Correlates of Workplace Anti‐Social Behavior
Authors: Lee Kibeom , Ashton Michael C. , Shin Kang‐Hyun
Published: January 2005

La relation entre le comportement antisocial au travail (ASB) et des traits de personnalité généraux a étéétudiée sur un échantillon composé de 267 salariés coréens. L’ASB au travail a été conceptualiséà partir de deux dimensions, l’ASB dirigée contre les individues (ASBI) et l’ASB dirigée contre l’organisation (ASBO). La personnalité a étéévaluée grâce au Big Five et à un sixième facteur ≪honnêteté‐humilité≫ (Ashton & Lee, 2001). Les analyses de régression multiple indiquèrent que l’honnêteté‐humilité et l’extraversion jouaient un rôle essentiel dans la prédiction de l’ASBI et de l’ASBO. De plus, Agreeablenessétait reliée à l’ASBI tandis que Conscientiousness l’était à l’ASBO. On parle aussi de la nécessité d’adopter un modèle optimal des traits de personnalité.

The relationship between workplace Anti‐Social Behavior (ASB) and higher‐order personality traits was investigated using a sample of 267 Korean employees. Workplace ASB was conceptualized as having two dimensions: ASB directed against individuals (ASBI) and ASB directed against the organization (ASBO). Personality was assessed using adjective measures of the Big Five factors and of a sixth factor, Honesty‐Humility (Ashton & Lee, 2001). Multiple regression analyses indicated that Honesty‐Humility and Extraversion played prominent roles in predicting both ASBI and ASBO. Also, Agreeableness was related to ASBI, whereas Conscientiousness was related to ASBO. The importance of adopting an optimal framework of personality traits was discussed.
Stress in Academic Life: Work Characteristics as Predictors of Student Well‐being and Performance
Authors: Chambel Maria José , Curral Luís
Published: January 2005

La relation entre les caractéristiques du travail, le bien‐être des étudiants et la performance a étéévaluée à partir du modèle de Karasck & Theorell ≪Travail, exigences, contrôle, soutien≫ (1990). Un échantillon d’étudiants portugais (N= 825) a répondu à un questionnaire comprenant des mesures du contrôle et des exigences du travail universitaire, du soutien des pairs, de la satisfaction relative à la vie universitaire, de l’anxiété/dépression et des résultats aux examens. Il apparut, comme dans d’aures contextes de travail, que la satisfaction des étudiants pour ce qui est de la vie universitaire, ainsi que les niveaux d’anxiété/dépression étaient fortement dépendants de leur perception des caractéristiques du travail. Les niveaux de satisfaction ont un effet direct sur la performance et agissent sur la relation entre la maîtrise du travail universitaire et la performance.

The relationship between work characteristics, student well‐being and performance was assessed, based upon Karasek and Theorell's (1990) Job Demands–Control–Support model. A sample of Portuguese university students (N= 825) answered a questionnaire comprising measures of academic work demands and control, peer support, satisfaction with academic life, anxiety/depression and academic performance. Results suggested that, similar to other work contexts, student satisfaction with academic life and anxiety/depression levels are strongly dependent on their perceptions of work characteristics. Levels of satisfaction have a direct impact on student performance and mediate the relationship between academic work control and performance.
Second‐Generation Poverty Reduction Strategies: New Opportunities and Emerging Issues
Authors: Driscoll Ruth , Evans Alison
Published: January 2005

The poverty reduction strategy paper (PRSP) approach has taken centre stage in development asssistance over the past five years. International endorsement of the approach has led to important gains in government focus on poverty reduction, civil society participation and donor behaviour. Yet PRSPs also potentially offer a much greater contribution to aid effectiveness, good governance and poverty reduction in developing countries. With a second generation of PRSPs now set to appear, this article examines the technical and political challenges that need addressing to realise their potential over time. Emerging issues include how to respond to political transitions, alternative design approaches, how to assess financing needs, and ways of enhancing the predictability of aid.
Uganda: No More Pro‐poor Growth?
Authors: Kappel Robert , Lay Jann , Steiner Susan
Published: January 2005

This article explores changing growth regimes in Uganda, from pro‐poor growth in the 1990s to growth without poverty reduction, actually even with a slight increase in poverty, after 2000. Not surprisingly, it finds that good agricultural performance is the key determinant of direct pro‐poor growth in the 1990s, while lower agricultural growth is the root cause of the recent increase in poverty. At the same time, after 2000 low agricultural growth appears to have induced important employment shifts out of agriculture, which have dampened the increase in poverty. The article also assesses the indirect form of pro‐poor growth by analysing the incidence of public spending and the tax system, and finds that indirect pro‐poor growth has been achieved to only a limited extent.
Market Structure, Efficiency and Rising Consolidation of the Banking Industry in the Euro Area
Authors: Kapopoulos Panayotis , Siokis Fotios
Published: January 2005

Four factors are fundamentally altering the financial landscape in the Euro Area: deregulation, further disintermediation provoked by the common currency and common monetary policy, technological advances and increased competition from non‐bank intermediaries. Faced with the combined pressures of these factors, banks are devising strategies to do business in this new environment. They respond by attempting to improve their efficiency and/or market power through consolidation and balance sheet restructuring. This article examines whether the ongoing process of consolidation should be rationalized on the basis of the benefits of economies of scale and scope or to the attempt of banks to tackle excess capacity problems. Empirical findings reveal a significant effect of efficiency measures on banking profitability indices. Also, we argue that further disintermediation caused by common currency and common monetary policy poses a threat to banks' profitability. Finally, these results have some implications for merger and antitrust policy as well as for supervisory and regulatory practices.
Beliefs, Bailouts and Spread of Bank Panics
Authors: Vaugirard Victor
Published: January 2005

This article highlights the spread of bank panics across countries, as the public reassesses governments' propensity to bailouts. Policymakers decide whether to save collapsing banking systems by weighing social costs of crises against the costs associated with raising taxes to finance rescue packages. Policymakers know those social costs of bank liquidation whereas the public does not. In this setup, financial crises may result from the public's self‐fulfilling prophecies about equilibrium outcomes, as lenders' expectations impinge on the taxation cost of bailouts. It follows that a banking crisis in a country leads creditors to reexamine policymakers' willingness to bailouts in other countries, which eventually makes their banks more vulnerable to self‐confirming depositors' runs.
A Data Mining Approach to Forming Generic Bills of Materials in Support of Variant Design Activities
Authors: Romanowski , Carol J. , Nagi Rakesh
Published: January 2005

In variant design, the proliferation of bills of materials makes it difficult for designers to find previous designs that would aid in completing a new design task. This research presents a novel, data mining approach to forming generic bills of materials (GBOMs), entities that represent the different variants in a product family and facilitate the search for similar designs and configuration of new variants. The technical difficulties include: (i) developing families or categories for products, assemblies, and component parts; (ii) generalizing purchased parts and quantifying their similarity; (iii) performing tree union; and (iv) establishing design constraints. These challenges are met through data mining methods such as text and tree mining, a new tree union procedure, and embodying the GBOM and design constraints in constrained XML. The paper concludes with a case study, using data from a manufacturer of nurse call devices, and identifies a new research direction for data mining motivated by the domains of engineering design and information.
Product Lifecycle Management for Performance Support
Authors: Pham Duc T. , Dimov , Stefan S. , Setchi , Rossitza M. , Peat , Bernard , Soroka , Anthony J. , Brousseau , Emmanuel B. , Huneiti , Ammar M. , Lagos , Nikolaos , Noyvirt , Alexander E. , Pasantonopoulos , Charilaos , Tsaneva , Daniela K. , Tang Qiao
Published: January 2005

This paper shows how product lifecycle information can be utilized to assist people engaged in product lifecycle tasks, in particular those concerned with product support. A progression of product data management methods based on knowledge engineering techniques is presented to allow the creation and delivery of effective, personalized performance support information. The product data management methods discussed include semantic hypermedia authoring, automated construction of product documentation, automated diagnostic module construction, and adaptive product support generation. These methods are utilized to improve the performance of product lifecycle actors, while reducing the time, knowledge, and input required from them, through increased task support and automation.
Cardiovascular Magnetic Resonance in Cardiac Amyloidosis
Authors: Maceira Alicia Maria , Joshi Jayshree , Prasad Sanjay Kumar , Moon James Charles , Perugini Enrica , Harding Idris , Sheppard Mary Noelle , Poole-Wilson Philip Alexander , Hawkins Philip Nigel , Pennell Dudley John
Published: January 2005

Background—

Cardiac amyloidosis can be diagnostically challenging. Cardiovascular magnetic resonance (CMR) can assess abnormal myocardial interstitium.

Methods and Results—

Late gadolinium enhancement CMR was performed in 30 patients with cardiac amyloidosis. In 22 of these, myocardial gadolinium kinetics with T
1
mapping was compared with that in 16 hypertensive controls. One patient had CMR and autopsy only. Subendocardial T
1
in amyloid patients was shorter than in controls (at 4 minutes: 427±73 versus 579±75 ms;
P
<0.01), was shorter than subepicardium T
1
for the first 8 minutes (
P
≤0.01), and was correlated with markers of increased myocardial amyloid load, as follows: left ventricular (LV) mass (
r
=−0.51,
P
=0.013); wall thickness (
r
=−0.54 to −0.63,
P
<0.04); interatrial septal thickness (
r
=−0.52,
P
=0.001); and diastolic function (
r
=−0.42,
P
=0.025). Global subendocardial late gadolinium enhancement was found in 20 amyloid patients (69%); these patients had greater LV mass (126±30 versus 93±25 g/m
2
;
P
=0.009) than unenhanced patients. Histological quantification showed substantial interstitial expansion with amyloid (30.5%) but only minor fibrosis (1.3%). Amyloid was dominantly subendocardial (42%) compared with midwall (29%) and subepicardium (18%). There was 97% concordance in diagnosis of cardiac amyloid by combining the presence of late gadolinium enhancement and an optimized T
1
threshold (191 ms at 4 minutes) between myocardium and blood.

Conclusions—

In cardiac amyloidosis, CMR shows a characteristic pattern of global subendocardial late enhancement coupled with abnormal myocardial and blood-pool gadolinium kinetics. The findings agree with the transmural histological distribution of amyloid protein and the cardiac amyloid load and may prove to have value in diagnosis and treatment follow-up.
Weight Loss and the Renin-Angiotensin-Aldosterone System
Authors: Engeli Stefan , Böhnke Jana , Gorzelniak Kerstin , Janke Jürgen , Schling Petra , Bader Michael , Luft Friedrich C. , Sharma Arya M.
Published: January 2005

The renin-angiotensin-aldosterone system has been causally implicated in obesity-associated hypertension. We studied the influence of obesity and weight reduction on the circulating and adipose tissue renin-angiotensin-aldosterone system in menopausal women. Blood samples were analyzed for angiotensinogen, renin, aldosterone, angiotensin-converting enzyme activity, and angiotensin II. In adipose tissue biopsy samples, we analyzed angiotensinogen, renin, renin-receptor, angiotensin-converting enzyme, and angiotensin II type-1 receptor gene expression. Obese women (n=19) had higher circulating angiotensinogen, renin, aldosterone, and angiotensin-converting enzyme than lean women (n=19), and lower angiotensinogen gene expression in adipose tissue. Seventeen women successfully participated in a weight reduction protocol over 13 weeks to reduce daily caloric intake by 600 kcal. Body weight was reduced by −5%, as were angiotensinogen levels by −27%, renin by −43%, aldosterone by −31%, angiotensin-converting enzyme activity by −12%, and angiotensinogen expression by −20% in adipose tissue (all
P
<0.05). The plasma angiotensinogen decrease was highly correlated with the waist circumference decline (
r
=0.74;
P
<0.001). Weight and renin-angiotensin-aldosterone system reductions were accompanied by a −7-mm Hg reduced systolic ambulatory blood pressure. These data suggest that a 5% reduction in body weight can lead to a meaningfully reduced renin-angiotensin-aldosterone system in plasma and adipose tissue, which may contribute to the reduced blood pressure.
Safeguarding Hospitality Service When the Unexpected Happens
Authors: Kwortnik Robert J.
Published: January 2005

The blackout of '03 took many hoteliers in the northeastern United States and Canada largely by surprise. Hotel managers found themselves scrambling to serve guests overnight in darkened hotels, many of which did not have running water, let alone expected amenities. Despite the challenges, hoteliers responding to a postblackout survey reported that their staff members were up to the task of providing hospitality for guests—often by devising creative processes for check-in and checkout, food service, and the like. For their part, guests were mostly understanding about the power failure and appreciated hotel employees' efforts on their behalf. However, guests were surprised that hotels often did not have backup power to maintain critical systems after emergency power failed. Service quality and the guest experience typically suffered at those hotels that lost power and were ill prepared to deal with disruptions in the service system. This article examines these problems and provides insights for how to safeguard service when the unexpected happens.
Multibranding Strategy
Authors: Enz Cathy A.
Published: January 2005

A case analysis examines the Yum! Brands strategy of cobranding. Yum! Brands may be the most aggressive of all restaurant franchisors in combining multiple concepts in one location. Intended to boost sales per unit, the cobranding strategy allows Yum! to locate restaurants in locations that might not support a single concept by increasing the traffic and sales at a particular location. So far, the chief downside of the strategy is potential complexity in operating differing brands in one restaurant. On balance, however, the strategy has allowed Yum! to expand its brands both in terms of number of restaurants and in terms of systemwide sales. Yum! is extending its cobranding experiment to combine its Pizza Hut concept with that of Pasta Bravo, a separate firm's casual pasta restaurant.
Color-Blind Racial Ideology and Psychological False Consciousness Among African Americans
Authors: Neville Helen A. , Coleman M. Nikki , Falconer Jameca Woody , Holmes Deadre
Published: January 2005

The relations between color-blind racial beliefs (i.e., denial and distortion of the existence of racism) and dimensions of PFC (i.e., false beliefs that serve to work against one’s individual or group interest) among 211 African Americans was investigated. Findings indicated that greater endorsement of color-blind racial beliefs was related to the three dimensions of PFC investigated, including higher levels of (a) victim blame attributions of racial inequality, (b) internalized oppression, and (c) justification of social roles or social dominance orientation. K- means cluster analysis among all variables was used to identify racial ideology types. Results suggested that the three multivariate types uncovered—racialized egalitarian consciousness, structural psychological false consciousness, and psychological false consciousness—were differentially related to system blame attributions and out-group friendship preferences. Implications of the findings and future directions are discussed.
Confronting Stigma: Community Involvement and Psychological Well-Being Among HIV-Positive Latino Gay Men
Authors: Ramirez-Valles Jesus , Fergus Stevenson , Reisen Carol A. , Poppen Paul J. , Zea Maria Cecilia
Published: January 2005

Theories of social integration and stress process posit that community involvement may buffer or may compensate the adverse effects of stigma on psychological well-being. In this article, the authors explore this thesis in a stigmatized and seldom studied group of HIV-positive Latino gay men. Specifically, they examine the effects of community involvement in AIDS and gay-related organizations (e.g., volunteerism and activism) and experienced homosexual stigma on three psychological well-being indicators (i.e., self-esteem, depression, and loneliness). The cross-sectional sample includes 155 HIV-positive men living in New York City and Washington, DC. Results suggest that experienced stigma attributed to homosexuality is associated with psychological well-being. Community involvement, however, seems to compensate the association between stigma and depression and loneliness, while buffering the association with self-esteem. Furthermore, community involvement appears to also heighten the perception of stigma.