bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface modification of polyethylene by medium pressure microplasma generator
Authors: Yamamoto R K , Pessoa R S , Massi M , Grigorov K G , Gongora‐Rubio M R , Maciel H S
Published: August 2009

Polyethylene surface modification studies were performed in a new microplasma source using O2 and N2 gases. The degree of modification of polyethylene surface was qualitatively investigated through water contact angle measurements using distilled water. The influence of the plasma discharge parameters, such as gas nature, gas flow, power and exposure time, over the polyethylene contact angle was investigated. The obtained results indicate a decrease of the contact angle from 100° (for untreated sample) to 22·9°, when N2 plasma was used for 40 s and discharge power >2 W. The surface morphology of the samples was examined by atomic force microscope and a smoothing effect after the plasma treatment was found. These results are very promising because of the experimental set‐up which requires medium vacuum, exhibit low process temperature (50–100°C) leaving the surface intact. Other advantages are the very short processing time (60 s) and applicability to large area substrates.
On concept of process signature in analysis of multistage surface formation
Authors: Mansori M. El , Mezghani S. , Sabri L. , Zahouani H.
Published: August 2009

In this work, an attempt is made to develop a novel approach based on the concept of process signatures to investigate the correlation of the quality of manufactured surface and the process of its generation which is independent to manufacturing conditions. The process signature is the multiscale modifications of surface topography, which depicts the essential changes of the surface state produced on the original surface after abrasive machining. An advanced signal processing technique, the continuous wavelets transform is used to identify the multiscale transfer function of the process which represents the amount of surface modifications. The applicability of this methodology is demonstrated by several practical examples. It is shown that the signature is strongly influenced by abrasive dispersity and granulometry, process induced modes of deformation. The work demonstrates also that the process signatures respond in a predictable fashion to changes in process variables and combinations of stage.
Which effective viscosity?
Authors: N. Petford
Published: August 2009

Magmas undergoing shear are prime examples of flows that involve the transport of solids and gases by a separate (silicate melt) carrier phase. Such flows are called multiphase, and have attracted much attention due to their important range of engineering applications. Where the volume fraction of the dispersed phase (crystals) is large, the influence of particles on the fluid motion becomes significant and must be taken into account in any explanation of the bulk behaviour of the mixture. For congested magma deforming well in excess of the dilute limit (particle concentrations >40% by volume), sudden changes in the effective or relative viscosity can be expected. The picture is complicated further by the fact that the melt phase is temperature- and shear-rate-dependent. In the absence of a constitutive law for the flow of congested magma under an applied force, it is far from clear which of the many hundreds of empirical formulae devised to predict the rheology of suspensions as the particle fraction increases with time are best suited. Some of the more commonly used expressions in geology and engineering are reviewed with an aim to home in on those variables key to an improved understanding of magma rheology. These include a temperature, compositional and shear-rate dependency of viscosity of the melt phase with the shear-rate dependency of the crystal (particle) packing arrangement. Building on previous formulations, a new expression for the effective (relative) viscosity of magma is proposed that gives users the option to define a packing fraction range as a function of shear stress. Comparison is drawn between processes (segregation, clustering, jamming), common in industrial slurries, and structures seen preserved in igneous rocks. An equivalence is made such that congested magma, viewed in purely mechanical terms as a high-temperature slurry, is an inherently nonequilibrium material where flow at large Pe´clet numbers may result in shear thinning and spontaneous development of layering.
Steverustite, Pb52+(OH)5[Cu+(S6+O3S2–)3](H2O)2, a new thiosulphate mineral from the Frongoch Mine Dump, Devils Bridge, Ceredigion, Wales: description and crystal structure
Authors: Cooper M. A. , Hawthorne F. C. , E. Moffatt
Published: August 2009

Steverustite, ideally Pb52+(OH)5[Cu+(S6+O3S2–)3](H2O)2, is a new supergene mineral from the Frongoch mine dump, Devils Bridge, Ceredigion, Wales. It generally forms fibrous fan-like bundles that occur in small cavities in quartz veins with other supergene species. Crystals are fibrous to acicular, elongated along [010], and are bounded by (h0l) faces too small to index reliably. It is transparent, colourless to white with a white streak, has a vitreous lustre, does not fluoresce under ultraviolet light and is brittle with a splintery fracture. The calculated density is 5.150 g/cm3, and the calculated mean refractive index is 1.94. The mineral is monoclinic, P21/n, a 12.5631(7), b 8.8963(5), c 18.0132(11) Å, β 96.459(1)º, V 2000.5(3) Å3, Z = 4, a:b:c = 1.41217:1:2.02480. The seven strongest lines in the X-ray powder diffraction pattern are as follows: d (Å), I, (h k l): 3.934, 10, (Ī14); 3.934, 8, (Ī11); 3.348, 7, (313); 6.211, 6, (200); 4.797, 6, (211); 3.026, 6, (314); 2.837, 5, (016). Chemical analysis by electron microprobe gave PbO 72.59, SO3 15.78, Cu2O 4.47, S2– 6.32, H2O 4.83, O=S2– –3.15, total 100.84 wt.% where the amount of H2O was determined by crystal-structure analysis. The resulting empirical formula is Pb4.992+Cu0.96+(S6+O3S2–)3.03(OH)4.88(H2O)1.67, based on O + OH + H2O + S2– = 18.67 a.p.f.u. (atoms per formula unit) with H2O = 1.67 a.p.f.u. (from crystal-structure solution and refinement).

The crystal structure of steverustite was solved by direct methods and refined to R1 = 2.7% for 3366 unique (Fo > 4σF) reflections. There are five distinct Pb2+ cations with coordination numbers from [8] to [11], all of which show stereoactive lone-pair behaviour and which form a strongly bonded cluster of composition [Pb5(OH)5]. There is one Cu+ cation triangularly coordinated by three S2– atoms that belong to three thiosulphate groups, forming a Cu+(S6+O3S2–)3 group. The [Pb5(OH)5] units and [Cu(S2O3)3] groups occur at the vertices of interpenetrating 36 nets to form layers of composition [Pb5(OH)5Cu(S2O3)3] parallel to (010) which are linked by weaker bonds. Examination of the stereochemistry of thiosulphate and thionate structures shows that the combination of  and S–S distances are distinct for these two types of structures.
Mercurian sphalerite from Akoluk deposit (Ordu, NE Turkey): Hg as a cathodoluminescence activator
Authors: Çiftçi E.
Published: August 2009

A recent investigation of sphalerite from Akoluk deposit, Ordu, NE Turkey, revealed the possible presence of a new activator element in the sphalerite structure. The sample was studied under a reflected light microscope coupled with a cold-stage cathodoluminescence (CL) system which revealed a unique banding in the sphalerite. The same sample was subsequently examined using the backscattered electron and luminescence modes in an electron microscope, the results of which were later confirmed in terms of chemical composition by electron probe microanalyses (EPMA). Detailed evaluation of the EPMA data indicated the presence of a new CL activator element in the sphalerite structure. The data also indicate that Hg2+ in the sphalerite crystal structure substitutes for Zn in a simple manner and for Cd and Cu in a coupled manner. Spectral analysis indicated a bright yellow and orange-red blend (more like brown) CL colour with λmax centred at 580 nm, probably due to Cd and Mn ions, and relatively broad emission bands ranging from 525 to 690 nm with λmax centred at 580 and 700, due probably to Cu, Cd and Hg. This study reports that Hg in the sphalerite crystal lattice behaves as an activator and/or co-activator element resulting in emissions of CL colours that range from yellow with purple shades to shades of brown, based on their varying contents.
The effect of non-stoichiometry on the high-temperature behaviour of MgAl2O4 spinel
Authors: Nestola F. , Secco L. , Bruno M. , Prencipe M. , Martignago F. , Princivalle F. , Dal Negro A.
Published: August 2009

The effect of cation vacancies upon the thermal expansion and crystal structure of a synthetic defect spinel with composition Mg0.4Al2.4☐0.2O4 was investigated by X-ray diffraction, in situ, at temperatures up to 1273 K. No evidence of symmetry violations from the Fd3m evenat the highest temperature were noted. The volume thermal expansion is markedly less than that of stoichiometric MgAl2O4 spinel, regardless of the degree of inversion. The u oxygen atomic coordinate remains constant throughout the temperature range investigated, with the M–O an dT–O bond lengths showing identical rates of expansivities. An analysis of the evolution of polyhedral volumes with temperature indicates that at 1273 K the octahedron inflates by 0.099 Å3 and the tetrahedron by 0.056 Å3. The expansion of the octahedron is significantly greater than in stoichiometric MgAl2O4 spinel, whereas the expansion of the tetrahedron is similar. The results demonstrate that an excess of Al in the spinel structure accompanied by the formation of cation vacancies strongly affect an important thermodynamic property, in this case, thermal expansion. Such an effect must be considered for those phases stable inthe Earth’s mantle where 4–5 wt.% Al2O3 is thought to be present.
Zirconolite and calzirtite in banded forsterite-spinel-calcite skarn ejecta from the 1631 eruption of Vesuvius: inferences for magma-wallrock interactions
Authors: Pascal M.-L. , Di Muro A. , Fonteilles M. , Principe C.
Published: August 2009

Two Ca-Zr-Ti oxides, zirconolite CaZrTi2O7 and calzirtite Ca2Zr5Ti2O16, occur as minute interstitial crystals in skarn (forsterite-spinel-calcite, with rhythmic banding) ejecta from the 1631 eruption of Vesuvius. The substitutions in zirconolite observed here mainly include Nb-for-Ti (typical for zirconolites in alkaline magmatic surroundings) and (Th,U)-for-Ca, and produce a crystal-chemical formula Ca0.9–1Th0.04–0.12U0.04–0.10ZrTi1.36–1.61Nb0.09–0.22(Fe,Mg,Al)0.29–0.47O7. The skarn, which occurs in contact with a pyroxenite of magmatic origin, displays a mineralogical zoning with Zr-, Ti-, Nb- and (U,Th)-rich oxides (e.g. Nb-perovskite and zirconolite) close to the pyroxenite (<2 mm), whereas those oxides observed further from the pyroxenite (>1 cm) are richer still in Zr but (Ti, Nb, U, Th)-poor or free (e.g. calzirtite and baddeleyite ZrO2). Textural relationships between minerals provide evidence for a metasomatic development of the skarn at the expense of the pyroxenite, through drastic leaching of Na, K, Si, Fe. The same process is responsible for the zoning in the skarn (leaching of Fe, Si, Ti, Nb, U and Th), in which Zr was less mobilized than other HFSE. This process, related to the circulation of fluids equilibrated with carbonates, is responsible for those forsterite-spinel (± calcite) skarns which can be observed as remnants in a large part of the 1631 ejecta. Such endoskarns probably formed repeatedly during at least the last millennia of Vesuvius’ history, and existed prior to the emplacement at shallow depth of the 1631 magma whose chamber walls were different from the limestone/dolostone classically assumed to host the Vesuvius magmas (Fulignati et al., 2005).
How I monitor residual disease in chronic myeloid leukemia
Authors: Radich Jerald P.
Published: August 2009

Molecular monitoring in chronic myeloid leukemia (CML) is a powerful tool to document treatment responses and predict relapse. Nonetheless, the proliferation of clinical trials and “guidelines” using the molecular endpoints of CML has outpaced practice norms, commercial laboratory application, and reimbursement practices, leaving some anxiety (if not confusion and despair) about molecular monitoring in the day-to-day treatment of CML. This article will try to address these issues by describing how I monitor CML, which, in summary, is with interest and without panic.
Dominant role of CD47–thrombospondin-1 interactions in myeloma-induced fusion of human dendritic cells: implications for bone disease
Authors: Kukreja Anjli , Radfar Soroosh , Sun Ben-Hua , Insogna Karl , Dhodapkar Madhav V.
Published: August 2009

Lytic bone disease in myeloma is characterized by an increase in multinucleate osteoclasts in close proximity to tumor cells. However, the nature of osteoclast precursors and the mechanisms underlying multinuclearity are less understood. Here we show that culture of myeloma cell lines as well as primary myeloma cells with human dendritic cells (DCs) but not monocytes or macrophages leads to spontaneous cell-cell fusion, which then leads to the facile formation of multinucleate bone-resorbing giant cells. Osteoclastogenesis is cell contact dependent, leading to up-regulation of thrombospondin-1 (TSP-1) in DCs. Disruption of CD47–TSP-1 interaction by TSP-1–blocking antibodies or down-regulation of CD47 on tumor cells by RNA interference abrogates tumor-induced osteoclast formation. Blockade of CD47–TSP-1 interactions also inhibits receptor activator for nuclear factor κB ligand- and macrophage colony-stimulating factor–induced formation of osteoclasts from human monocytes. Further, TSP-1 blockade attenuates hypercalcemia induced by parathyroid hormone in vivo. These data point to a role for CD47–TSP-1 interactions in regulating cell-fusion events involved in human osteoclast formation. They also suggest that DCs, known to be enriched in myeloma tumors, may be direct precursors for tumor-associated osteoclasts. Disruption of CD47–TSP-1 interactions or preventing the recruitment of DCs to tumors may provide novel approaches to therapy of myeloma bone disease and osteoporosis.
How to be an attractive male: floral dimorphism and attractiveness to pollinators in a dioecious plant
Authors: Waelti Marc O , Page Paul A , Widmer Alex , Schiestl Florian P
Published: August 2009

Background

Sexual selection theory predicts that males are limited in their reproductive success by access to mates, whereas females are more limited by resources. In animal-pollinated plants, attraction of pollinators and successful pollination is crucial for reproductive success. In dioecious plant species, males should thus be selected to increase their attractiveness to pollinators by investing more than females in floral traits that enhance pollinator visitation. We tested the prediction of higher attractiveness of male flowers in the dioecious, moth-pollinated herb Silene latifolia, by investigating floral signals (floral display and fragrance) and conducting behavioral experiments with the pollinator-moth, Hadena bicruris.

Results

As found in previous studies, male plants produced more but smaller flowers. Male flowers, however, emitted significantly larger amounts of scent than female flowers, especially of the pollinator-attracting compounds. In behavioral tests we showed that naïve pollinator-moths preferred male over female flowers, but this preference was only significant for male moths.

Conclusion

Our data suggest the evolution of dimorphic floral signals is shaped by sexual selection and pollinator preferences, causing sexual conflict in both plants and pollinators.
Do potatoes and tomatoes have a single evolutionary history, and what proportion of the genome supports this history?
Authors: Rodriguez Flor , Wu Feinan , Ané Cécile , Tanksley Steve , Spooner David M
Published: August 2009

Background

Phylogenies reconstructed with only one or a few independently inherited loci may be unresolved or incongruent due to taxon and gene sampling, horizontal gene transfer, or differential selection and lineage sorting at individual loci. In an effort to remedy this situation, we examined the utility of conserved orthologous set (COSII) nuclear loci to elucidate the phylogenetic relationships among 29 diploid Solanum species in the sister clades that include tomato and potato, and in Datura inoxia as a far outgroup. We screened 40 COSII markers with intron content over 60% that are mapped in different chromosomes; selected a subset of 19 by the presence of single band amplification of size mostly between 600 and 1200 bp; sequenced these 19 COSII markers, and performed phylogenetic analyses with individual and concatenated datasets. The present study attempts to provide a fully resolved phylogeny among the main clades in potato and tomato that can help to identify the appropriate markers for future studies using additional species.

Results

Among potatoes, when total evidence is invoked, one single predominant history is highlighted with complete resolution within and among the three main clades. It also supports the hypothesis of the North and Central American B-genome origin of the tuber-bearing members of Solanum sect. Petota and shows a clear division between A genomes in clades 3 and 4, and B genomes in clade 1+2. On the other hand, when a prior agreement approach is invoked other potato evolutionary histories are revealed but with less support. These alternative histories could be explained by past hybridization, or fast rates of speciation. In the case of tomato, the analyses with all sequence data completely resolved 19 of 21 clades, for the first time revealed the monophyly of five clades, and gave further support for the recent segregation of new species from the former Solanum peruvianum. Concordance analyses revealed and summarized the extensive discordance among COSII markers. Some potential reasons for discordance could be methodological, to include systematic errors due to using a wrong model of sequence evolution, coupled with long branches, or mixtures of branch lengths within COSII, or undetected paralogy or alignment bias. Other reasons could be biological processes such as hybridization or lineage sorting.

Conclusion

This study confirms and quantifies the utility of using DNA sequences from different parts of the genome in phylogenetic studies to avoid possible bias in the sampling. It shows that 11–18 loci are enough to get the dominant history in this group of Solanum, but more loci would be needed to discern the distribution of gene genealogies in more depth, and thus detect which mechanism most likely shaped the discordance.
Grapevine cell early activation of specific responses to DIMEB, a resveratrol elicitor
Authors: Zamboni Anita , Gatto Pamela , Cestaro Alessandro , Pilati Stefania , Viola Roberto , Mattivi Fulvio , Moser Claudio , Velasco Riccardo
Published: August 2009

Background

In response to pathogen attack, grapevine synthesizes phytoalexins belonging to the family of stilbenes. Grapevine cell cultures represent a good model system for studying the basic mechanisms of plant response to biotic and abiotic elicitors. Among these, modified β-cyclodextrins seem to act as true elicitors inducing strong production of the stilbene resveratrol.

Results

The transcriptome changes of Vitis riparia × Vitis berlandieri grapevine cells in response to the modified β-cyclodextrin, DIMEB, were analyzed 2 and 6 h after treatment using a suppression subtractive hybridization experiment and a microarray analysis respectively. At both time points, we identified a specific set of induced genes belonging to the general phenylpropanoid metabolism, including stilbenes and hydroxycinnamates, and to defence proteins such as PR proteins and chitinases. At 6 h we also observed a down-regulation of the genes involved in cell division and cell-wall loosening.

Conclusions

We report the first large-scale study of the molecular effects of DIMEB, a resveratrol inducer, on grapevine cell cultures. This molecule seems to mimic a defence elicitor which enhances the physical barriers of the cell, stops cell division and induces phytoalexin synthesis.
The RHNumtS compilation: Features and bioinformatics approaches to locate and quantify Human NumtS
Authors: Lascaro Daniela , Castellana Stefano , Gasparre Giuseppe , Romeo Giovanni , Saccone Cecilia , Attimonelli Marcella
Published: August 2009

Background

To a greater or lesser extent, eukaryotic nuclear genomes contain fragments of their mitochondrial genome counterpart, deriving from the random insertion of damaged mtDNA fragments. NumtS (Nuclear mt Sequences) are not equally abundant in all species, and are redundant and polymorphic in terms of copy number. In population and clinical genetics, it is important to have a complete overview of NumtS quantity and location. Searching PubMed for NumtS or Mitochondrial pseudo-genes yields hundreds of papers reporting Human NumtS compilations produced byin silicoor wet-lab approaches. A comparison of published compilations clearly shows significant discrepancies among data, due both to unwise application of Bioinformatics methods and to a not yet correctly assembled nuclear genome. To optimize quantification and location of NumtS, we produced a consensus compilation of Human NumtS by applying various bioinformatics approaches.

Results

Location and quantification of NumtS may be achieved by applying database similarity searching methods: we have applied various methods such as Blastn, MegaBlast and BLAT, changing both parameters and database; the results were compared, further analysed and checked against the already published compilations, thus producing the Reference Human Numt Sequences (RHNumtS) compilation. The resulting NumtS total 190.

Conclusion

The RHNumtS compilation represents a highly reliable reference basis, which may allow designing a lab protocol to test the actual existence of each NumtS. Here we report preliminary results based on PCR amplification and sequencing on 41 NumtS selected from RHNumtS among those with lower score. In parallel, we are currently designing the RHNumtS database structure for implementation in the HmtDB resource. In the future, the same database will host NumtS compilations from other organisms, but these will be generated only when the nuclear genome of a specific organism has reached a high-quality level of assembly.
Integrative analysis of RUNX1 downstream pathways and target genes
Authors: Michaud Joëlle , Simpson Ken M , Escher Robert , Buchet-Poyau Karine , Beissbarth Tim , Carmichael Catherine , Ritchie Matthew E , Schütz Frédéric , Cannon Ping , Liu Marjorie , Shen Xiaofeng , Ito Yoshiaki , Raskind Wendy H , Horwitz Marshall S , Osato Motomi , Turner David R , Speed Terence P , Kavallaris Maria , Smyth Gordon K , Scott Hamish S
Published: August 2009

Background

TheRUNX1transcription factor gene is frequently mutated in sporadic myeloid and lymphoid leukemia through translocation, point mutation or amplification. It is also responsible for a familial platelet disorder with predisposition to acute myeloid leukemia (FPD-AML). The disruption of the largely unknown biological pathways controlled by RUNX1 is likely to be responsible for the development of leukemia. We have used multiple microarray platforms and bioinformatic techniques to help identify these biological pathways to aid in the understanding of why RUNX1 mutations lead to leukemia.

Results

Here we report genes regulated either directly or indirectly by RUNX1 based on the study of gene expression profiles generated from 3 different human and mouse platforms. The platforms used were global gene expression profiling of: 1) cell lines with RUNX1 mutations from FPD-AML patients, 2) over-expression of RUNX1 and CBFβ, and 3) Runx1 knockout mouse embryos using either cDNA or Affymetrix microarrays. We observe that our datasets (lists of differentially expressed genes) significantly correlate with published microarray data from sporadic AML patients with mutations in eitherRUNX1or its cofactor,CBFβ. A number of biological processes were identified among the differentially expressed genes and functional assays suggest that heterozygousRUNX1point mutations in patients with FPD-AML impair cell proliferation, microtubule dynamics and possibly genetic stability. In addition, analysis of the regulatory regions of the differentially expressed genes has for the first time systematically identified numerous potential novel RUNX1 target genes.

Conclusion

This work is the first large-scale study attempting to identify the genetic networks regulated by RUNX1, a master regulator in the development of the hematopoietic system and leukemia. The biological pathways and target genes controlled by RUNX1 will have considerable importance in disease progression in both familial and sporadic leukemia as well as therapeutic implications.
The human gastric pathogen Helicobacter pylori has a potential acetone carboxylase that enhances its ability to colonize mice
Authors: Brahmachary Priyanka , Wang Ge , Benoit Stéphane L , Weinberg Michael V , Maier Robert J , Hoover Timothy R
Published: August 2009

Background

Helicobacter pylori colonizes the human stomach and is the etiological agent of peptic ulcer disease. All three H. pylori strains that have been sequenced to date contain a potential operon whose products share homology with the subunits of acetone carboxylase (encoded by acxABC) from Xanthobacter autotrophicus strain Py2 and Rhodobacter capsulatus strain B10. Acetone carboxylase catalyzes the conversion of acetone to acetoacetate. Genes upstream of the putative acxABC operon encode enzymes that convert acetoacetate to acetoacetyl-CoA, which is metabolized further to generate two molecules of acetyl-CoA.

Results

To determine if the H. pylori acxABC operon has a role in host colonization the acxB homolog in the mouse-adapted H. pylori SS1 strain was inactivated with a chloramphenicol-resistance (cat) cassette. In mouse colonization studies the numbers of H. pylori recovered from mice inoculated with the acxB:cat mutant were generally one to two orders of magnitude lower than those recovered from mice inoculated with the parental strain. A statistical analysis of the data using a Wilcoxin Rank test indicated the differences in the numbers of H. pylori isolated from mice inoculated with the two strains were significant at the 99% confidence level. Levels of acetone associated with gastric tissue removed from uninfected mice were measured and found to range from 10–110 μmols per gram wet weight tissue.

Conclusion

The colonization defect of the acxB:cat mutant suggests a role for the acxABC operon in survival of the bacterium in the stomach. Products of the H. pylori acxABC operon may function primarily in acetone utilization or may catalyze a related reaction that is important for survival or growth in the host. H. pylori encounters significant levels of acetone in the stomach which it could use as a potential electron donor for microaerobic respiration.
Enhancing bile tolerance improves survival and persistence of Bifidobacterium and Lactococcus in the murine gastrointestinal tract
Authors: Watson Debbie , Sleator Roy D , Hill Colin , Gahan Cormac GM
Published: August 2009

Background

The majority of commensal gastrointestinal bacteria used as probiotics are highly adapted to the specialised environment of the large bowel. However, unlike pathogenic bacteria; they are often inadequately equipped to endure the physicochemical stresses of gastrointestinal (GI) delivery in the host. Herein we outline a patho-biotechnology strategy to improve gastric delivery and host adaptation of a probiotic strainBifidobacterium breveUCC2003 and the generally regarded as safe (GRAS) organismLactococcus lactisNZ9000.

Results

In vitrobile tolerance of both strains was significantly enhanced (P< 0.001), following heterologous expression of theListeria monocytogenesbile resistance mechanism BilE. Strains harbouringbilEwere also recovered at significantly higher levels (P< 0.001), than control strains from the faeces and intestines of mice (n= 5), following oral inoculation. Furthermore, aB. brevestrain expressingbilEdemonstrated increased efficacy relative to the wild-type strain in reducing oralL. monocytogenesinfection in mice.

Conclusion

Collectively the data indicates that bile tolerance can be enhanced inBifidobacteriumandLactococcusspecies through rational genetic manipulation and that this can significantly improve delivery to and colonisation of the GI tract.
Diversity of the parB and repA genes of the Burkholderia cepacia complex and their utility for rapid identification of Burkholderia cenocepacia
Authors: Drevinek Pavel , Baldwin Adam , Dowson Christopher G , Mahenthiralingam Eshwar
Published: August 2009

Background

Burkholderia cenocepacia is the most prominent species of the B. cepacia complex (Bcc), a group of nine closely related and difficult to identify bacteria that cause serious infections in patients with cystic fibrosis. Despite its clinical relevance, identification of B. cenocepacia as a single species is unavailable, as it splits by a widely used recA gene-based PCR identification method into discrete phylogenetic subgroups IIIA, IIIB, IIIC and IIID. With the aim of identifying gene targets suitable for unified detection of B. cenocepacia strains, we examined sequence polymorphisms in the repA and parB genes. These essential genes are involved in the replication and partitioning of bacterial replicons, hence we also had the opportunity for the first time to investigate the evolution of the multireplicon (three chromosome) structure of Bcc genomes.

Results

Alignment of the repA and parB genes from publicly available Bcc genome sequences enabled the design of primers for their amplification and sequence analysis. Multilocus sequencing typing, a highly discriminatory method for Bcc species and strain discrimination, was used to select strains of unique sequence types (STs) that spanned the known Bcc genetic diversity. Sequence datasets of repA (83 isolates, 67 STs) and parB (120 isolates, 95 STs) genes from the second chromosome were aligned and examined phylogenetically to identify polymorphisms suitable for identification of B. cenocepacia. In contrast to parB, the Bcc repA sequences demonstrated distinct clustering of B. cenocepacia from other species, which enabled the design a species-specific multiplex PCR. The novel single-reaction B. cenocepacia detection method was tested on a panel of 142 different Bcc strains (142 STs) and distinguished recA groups IIIA, IIIB and IIID, from all other Bcc members with 100% sensitivity and 93% specificity.

Conclusion

The repA-based multiplex PCR is a useful aid to the rapid identification of the most clinically relevant B. cenocepacia recA subgroups IIIA, IIIB and IIID. Phylogenetic analysis of repA and parB genes demonstrated that acquisition of the second and third replicons of Bcc genomes occurred prior to their differentiation into discrete species and that the sharing of replicons across species had not occurred.
The Kv2.1 K+ channel targets to the axon initial segment of hippocampal and cortical neurons in culture and in situ
Authors: Sarmiere Patrick D , Weigle Cecile M , Tamkun Michael M
Published: August 2009

Background

The Kv2.1 delayed-rectifier K+ channel regulates membrane excitability in hippocampal neurons where it targets to dynamic cell surface clusters on the soma and proximal dendrites. In the past, Kv2.1 has been assumed to be absent from the axon initial segment.

Results

Transfected and endogenous Kv2.1 is now demonstrated to preferentially accumulate within the axon initial segment (AIS) over other neurite processes; 87% of 14 DIV hippocampal neurons show endogenous channel concentrated at the AIS relative to the soma and proximal dendrites. In contrast to the localization observed in pyramidal cells, GAD positive inhibitory neurons within the hippocampal cultures did not show AIS targeting. Photoactivable-GFP-Kv2.1-containing clusters at the AIS were stable, moving <1 μm/hr with no channel turnover. Photobleach studies indicated individual channels within the cluster perimeter were highly mobile (FRAP τ = 10.4 ± 4.8 sec), supporting our model that Kv2.1 clusters are formed by the retention of mobile channels behind a diffusion-limiting perimeter. Demonstrating that the AIS targeting is not a tissue culture artifact, Kv2.1 was found in axon initial segments within both the adult rat hippocampal CA1, CA2, and CA3 layers and cortex.

Conclusion

In summary, Kv2.1 is associated with the axon initial segment both in vitro and in vivo where it may modulate action potential frequency and back propagation. Since transfected Kv2.1 initially localizes to the AIS before appearing on the soma, it is likely multiple mechanisms regulate Kv2.1 trafficking to the cell surface.
Heat shock protein 90: translation from cancer to Alzheimer's disease treatment?
Authors: Luo Wenjie , Rodina Anna , Chiosis Gabriela
Published: August 2009

Both malignant transformation and neurodegeneration, as it occurs in Alzheimer's disease, are complex and lengthy multistep processes characterized by abnormal expression, post-translational modification, and processing of certain proteins. To maintain and allow the accumulation of these dysregulated processes, and to facilitate the step-wise evolution of the disease phenotype, cells must co-opt a compensatory regulatory mechanism. In cancer, this role has been attributed to heat shock protein 90 (Hsp90), a molecular chaperone that maintains the functional conformation of multiple proteins involved in cell-specific oncogenic processes. In this sense, at the phenotypic level, Hsp90 appears to serve as a biochemical buffer for the numerous cancer-specific lesions that are characteristic of diverse tumors. The current review proposes a similar role for Hsp90 in neurodegeneration. It will present experimentally demonstrated, but also hypothetical, roles that suggest Hsp90 can act as a regulator of pathogenic changes that lead to the neurodegenerative phenotype in Alzheimer's disease.
Epidemiology of constipation in Europe and Oceania: a systematic review
Authors: Peppas George , Alexiou Vangelis G , Mourtzoukou Eleni , Falagas Matthew E
Published: August 2009

Background

We aimed to review the literature regarding the epidemiology of constipation in Europe and Oceania and the associated prevalence/risk factors.

Methods

Two reviewers performed PubMed searches and a hand search of references. A study was considered eligible for inclusion if it reported data about the prevalence of constipation in any population, free of other gastrointestinal disorders, in Europe and Oceania. Studies were evaluated for quality. Data regarding the setting, type of study, definition of constipation, study population, prevalence of constipation, factors associated with increased odds for constipation, and the female to male ratio, were collected.

Results

The 21 reviewed studies depict prevalence rates in 34 different population groups ranging widely from a low 0.7% to a high 81%. In the general population of Europe the mean value of the reported constipation rates is 17,1 % and the median value 16.6%. Among the studies conducted in Oceania, the mean value of constipation prevalence was 15.3%. Female gender, age and socioeconomic and educational class seem to have major effect on constipation prevalence. A number of various other risk factors are, less clearly, associated with constipation.

Conclusion

This systematic review depicts the high prevalence and related risk factors of a disorder that decreases the health-related quality of life and has major economic consequences.
A survey of knowledge, attitudes and practices towards avian influenza in an adult population of Italy
Authors: Di Giuseppe Gabriella , Abbate Rossella , Albano Luciana , Marinelli Paolo , Angelillo Italo F
Published: August 2009

Background

Several public health strategic interventions are required for effective prevention and control of avian influenza (AI) and it is necessary to create a communication plan to keep families adequately informed on how to avoid or reduce exposure. This investigation determined the knowledge, attitudes, and behaviors relating to AI among an adult population in Italy.

Methods

From December 2005 to February 2006 a random sample of 1020 adults received a questionnaire about socio-demographic characteristics, knowledge of transmission and prevention about AI, attitudes towards AI, behaviors regarding use of preventive measures and food-handling practices, and sources of information about AI.

Results

A response rate of 67% was achieved. Those in higher socioeconomic classes were more likely to identify the modes of transmission and the animals' vehicles for AI. Those older, who knew the modes of transmission and the animals' vehicles for AI, and who still need information, were more likely to know that washing hands soap before and after touching raw poultry meat and using gloves is recommended to avoid spreading of AI through food. The risk of being infected was significantly higher in those from lower socioeconomic classes, if they did not know the definition of AI, if they knew that AI could be transmitted by eating and touching raw eggs and poultry foods, and if they did not need information. Compliance with the hygienic practices during handling of raw poultry meat was more likely in those who perceived to be at higher risk, who knew the hygienic practices, who knew the modes of transmission and the animals' vehicles for AI, and who received information from health professionals and scientific journals.

Conclusion

Respondents demonstrate no detailed understanding of AI, a greater perceived risk, and a lower compliance with precautions behaviors and health educational strategies are strongly needed.
Emergence of unusual human rotavirus strains in Salento, Italy, during 2006–2007
Authors: De Donno Antonella , Grassi Tiziana , Bagordo Francesco , Idolo Adele , Cavallaro Alessandra , Gabutti Giovanni ,   the Collaborative Group for the surveillance of Rotavirus Infection
Published: August 2009

Background

In recent years, rotavirus genotyping by RT-PCR has provided valuable information about the diversity of rotaviruses (RV) circulating throughout the world.

The purpose of the present study was to monitor the prevalence of the different G and P genotypes of rotaviruses circulating in Salento and detect any uncommon or novel types.

Methods

During the period from January 2006 to December 2007, a total of 243 rotavirus positive stool samples were collected from children with diarrhoea admitted to four Hospitals in the province of Lecce (Copertino, Galatina, Gallipoli and Tricase).

All the specimens were tested for RV by real time PCR and genotyped for VP7 (G-type) and VP4 (P-type) gene by reverse transcription (RT) and multiplex PCR using different type specific primers.

Results

In course of this study we identified 4 common G&P combinations viz. G2P[8], G1P[8], G2P[4] and G9P[8] amongst 59.8% of the typeable rotavirus positives.

Rotavirus G2P[8] was recognized as the most widespread genotype during the sentinel-based survey in Salento.

The detection of other novel and unusual strains, such as G2P[10], G4P[10], G8P[4], G9P[11] and G10P[8] is noteworthy.

Furthermore, a significant number of mixed infections were observed during the survey period but G3P[8] rotaviruses were not detected.

Conclusion

This study highlights the genetic diversity among rotaviruses isolated from children in Salento and the emergence of some novel strains. Therefore, it is highly essential to continuously monitor for these strains so as to assess the impact of vaccines on RV strains circulating in Salento and understand the effect of strain variation on efficacy of presently available vaccines.
Antiviral resistance during pandemic influenza: implications for stockpiling and drug use
Authors: Arino Julien , Bowman Christopher S , Moghadas Seyed M
Published: August 2009

Background

The anticipated extent of antiviral use during an influenza pandemic can have adverse consequences for the development of drug resistance and rationing of limited stockpiles. The strategic use of drugs is therefore a major public health concern in planning for effective pandemic responses.

Methods

We employed a mathematical model that includes both sensitive and resistant strains of a virus with pandemic potential, and applies antiviral drugs for treatment of clinical infections. Using estimated parameters in the published literature, the model was simulated for various sizes of stockpiles to evaluate the outcome of different antiviral strategies.

Results

We demonstrated that the emergence of highly transmissible resistant strains has no significant impact on the use of available stockpiles if treatment is maintained at low levels or the reproduction number of the sensitive strain is sufficiently high. However, moderate to high treatment levels can result in a more rapid depletion of stockpiles, leading to run-out, by promoting wide-spread drug resistance. We applied an antiviral strategy that delays the onset of aggressive treatment for a certain amount of time after the onset of the outbreak. Our results show that if high treatment levels are enforced too early during the outbreak, a second wave of infections can potentially occur with a substantially larger magnitude. However, a timely implementation of wide-scale treatment can prevent resistance spread in the population, and minimize the final size of the pandemic.

Conclusion

Our results reveal that conservative treatment levels during the early stages of the outbreak, followed by a timely increase in the scale of drug-use, will offer an effective strategy to manage drug resistance in the population and avoid run-out. For a 1918-like strain, the findings suggest that pandemic plans should consider stockpiling antiviral drugs to cover at least 20% of the population.
Lack of evidence for association of primary sclerosing cholangitis and primary biliary cirrhosis with risk alleles for Crohn's disease in Polish patients
Authors: Gaj Pawel , Habior Andrzej , Mikula Michal , Ostrowski Jerzy
Published: August 2009

Background

Numerous papers have addressed the association of mutations and polymorphisms of susceptibility genes with autoimmune inflammatory disorders. We investigated whether polymorphisms that confer susceptibility to Crohn's disease could be classified also as predisposing factors for the development of primary sclerosing cholangitis and primary biliary cirrhosis in Polish patients.

Methods

The study included 60 patients with CD, 77 patients with PSC, of which 61 exhibited IBD (40 UC, 8 CD, and 13 indeterminate colitis), and 144 patients with PBC. All the patients were screened against Crohn's disease associating genetic polymorphisms.

The polymorphisms were chosen according to previously confirmed evidence for association with Crohn's disease, including Pro268Ser, Arg702Trp, Gly908Arg and 1007fs in NOD2/CARD15, Leu503Phe/-207G>C in SLC22A4/OCTN1/SLC22A5/OCTN2, Arg30Gln in DLG5, Thr300Ala in ATG16L1, and Arg381Gln, His3Gln and exon-3'UTR in IL23R. Genotyping was carried out using TaqMan SNP genotyping assays.

Results

We confirmed a strong association between three NOD2/CARD15 gene variants (Pro268Ser, OR = 2.52, 95% CI = 1.34 – 4.75); (Arg702Trp, OR = 6.65, 95% CI = 1.99 – 22.17); (1007fs, OR = 9.59, 95% CI = 3.94 – 23.29), and a weak association between both the protective OCTN1/OCTN2 CC haplotype (OR = 0.28, 95% CI = 0.08 – 0.94), and a variant of ATG16L1 gene (Thr300Ala, OR = 0.468, 95% CI = 0.24 – 0.90) with Crohn's disease. In contrast, none of the polymorphisms exhibited association with susceptibility to primary sclerosing cholangitis and primary biliary cirrhosis, including a group of primary sclerosing cholangitis patients with concurrent IBD.

Conclusion

Although the clinical data indicate non-random co-occurrence of inflammatory bowel disease and primary sclerosing cholangitis, consistently with the previously published studies, no genetic association was found between the genetic variants predisposing to Crohn's disease and hepatobiliary autoimmune disorders. However, since estimation of genetic variant disproportion is limited by sample size, these negative results may also indicate that eventually shared genetic predispositions are too little to be captured by small patient groups.
French database of children and adolescents with Prader-Willi syndrome
Authors: Molinas Catherine , Cazals Laurent , Diene Gwenaelle , Glattard Melanie , Arnaud Catherine , Tauber Maithe ,   French Reference Centre for PWS (FrRefC-PWS)
Published: August 2009

Background

Prader-Willi syndrome (PWS) is a rare multisystem genetic disease leading to severe complications mainly related to obesity. We strongly lack information on the natural history of this complex disease and on what factors are involved in its evolution and its outcome. One of the objectives of the French reference centre for Prader-Willi syndrome set-up in 2004 was to set-up a database in order to make the inventory of Prader-Willi syndrome cases and initiate a national cohort study in the area covered by the centre.

Description

the database includes medical data of children and adolescents with Prader-Willi syndrome, details about their management, socio-demographic data on their families, psychological data and quality of life of the parents. The tools and organisation used to ensure data collection and data quality in respect of good clinical practice procedures are discussed, and main characteristics of our Prader-Willi population at inclusion are presented.

Conclusion

this database covering all the aspects of PWS clinical, psychological and social profiles, including familial psychological and quality of life will be a powerful tool for retrospective studies concerning this complex and multi factorial disease and could be a basis for the design of future prospective multicentric studies. The complete database and the Stata.do files are available to any researcher wishing to use them for non-commercial purposes and can be provided upon request to the corresponding author.
A systematic review of the prevalence and determinants of nonadherence to phosphate binding medication in patients with end-stage renal disease
Authors: Karamanidou Christina , Clatworthy Jane , Weinman John , Horne Rob
Published: August 2009

Background

Cardiovascular events are the leading cause of death in end stage renal disease (ESRD). Adherence to phosphate binding medication plays a vital role in reducing serum phosphorus and associated cardiovascular risk. This poses a challenge for patients as the regimen is often complex and there may be no noticeable impact of adherence on symptoms. There is a need to establish the level of nonadherence to phosphate binding medication in renal dialysis patients and identify the factors associated with it.

Methods

The online databases PsycINFO, Medline, Embase and CINAHL were searched for quantitative studies exploring predictors of nonadherence to phosphate binding medication in ESRD. Rates and predictors of nonadherence were extracted from the papers.

Results

Thirty four studies met the inclusion criteria. There was wide variation in reported rates of non-adherence (22–74% patients nonadherent, mean 51%). This can be partially attributed to differences in the way adherence has been defined and measured. Demographic and clinical predictors of nonadherence were most frequently assessed but only younger age was consistently associated with nonadherence. In contrast psychosocial variables (e.g. patients' beliefs about medication, social support, personality characteristics) were less frequently assessed but were more likely to be associated with nonadherence.

Conclusion

Nonadherence to phosphate binding medication appears to be prevalent in ESRD. Several potentially modifiable psychosocial factors were identified as predictors of nonadherence. There is a need for further, high-quality research to explore these factors in more detail, with the aim of informing the design of an intervention to facilitate adherence.