bluuebunny/crossref_metadata_2025 huggingface dataset:
Epithelial junction formation requires confinement of Cdc42 activity by a novel SH3BP1 complex
Authors: Elbediwy Ahmed , Zihni Ceniz , Terry Stephen J. , Clark Peter , Matter Karl , Balda Maria S.
Published: August 2012

Epithelial cell–cell adhesion and morphogenesis require dynamic control of actin-driven membrane remodeling. The Rho guanosine triphosphatase (GTPase) Cdc42 regulates sequential molecular processes during cell–cell junction formation; hence, mechanisms must exist that inactivate Cdc42 in a temporally and spatially controlled manner. In this paper, we identify SH3BP1, a GTPase-activating protein for Cdc42 and Rac, as a regulator of junction assembly and epithelial morphogenesis using a functional small interfering ribonucleic acid screen. Depletion of SH3BP1 resulted in loss of spatial control of Cdc42 activity, stalled membrane remodeling, and enhanced growth of filopodia. SH3BP1 formed a complex with JACOP/paracingulin, a junctional adaptor, and CD2AP, a scaffolding protein; both were required for normal Cdc42 signaling and junction formation. The filamentous actin–capping protein CapZ also associated with the SH3BP1 complex and was required for control of actin remodeling. Epithelial junction formation and morphogenesis thus require a dual activity complex, containing SH3BP1 and CapZ, that is recruited to sites of active membrane remodeling to guide Cdc42 signaling and cytoskeletal dynamics.
IL-1β mediates chronic intestinal inflammation by promoting the accumulation of IL-17A secreting innate lymphoid cells and CD4+ Th17 cells
Authors: Coccia Margherita , Harrison Oliver J. , Schiering Chris , Asquith Mark J. , Becher Burkhard , Powrie Fiona , Maloy Kevin J.
Published: August 2012

Although very high levels of interleukin (IL)-1β are present in the intestines of patients suffering from inflammatory bowel diseases (IBD), little is known about the contribution of IL-1β to intestinal pathology. Here, we used two complementary models of chronic intestinal inflammation to address the role of IL-1β in driving innate and adaptive pathology in the intestine. We show that IL-1β promotes innate immune pathology in Helicobacter hepaticus–triggered intestinal inflammation by augmenting the recruitment of granulocytes and the accumulation and activation of innate lymphoid cells (ILCs). Using a T cell transfer colitis model, we demonstrate a key role for T cell–specific IL-1 receptor (IL-1R) signals in the accumulation and survival of pathogenic CD4+ T cells in the colon. Furthermore, we show that IL-1β promotes Th17 responses from CD4+ T cells and ILCs in the intestine, and we describe synergistic interactions between IL-1β and IL-23 signals that sustain innate and adaptive inflammatory responses in the gut. These data identify multiple mechanisms through which IL-1β promotes intestinal pathology and suggest that targeting IL-1β may represent a useful therapeutic approach in IBD.
miR-146a controls the resolution of T cell responses in mice
Authors: Yang Lili , Boldin Mark P. , Yu Yang , Liu Claret Siyuan , Ea Chee-Kwee , Ramakrishnan Parameswaran , Taganov Konstantin D. , Zhao Jimmy L. , Baltimore David
Published: August 2012

T cell responses in mammals must be tightly regulated to both provide effective immune protection and avoid inflammation-induced pathology. NF-κB activation is a key signaling event induced by T cell receptor (TCR) stimulation. Dysregulation of NF-κB is associated with T cell–mediated inflammatory diseases and malignancies, highlighting the importance of negative feedback control of TCR-induced NF-κB activity. In this study we show that in mice, T cells lacking miR-146a are hyperactive in both acute antigenic responses and chronic inflammatory autoimmune responses. TCR-driven NF-κB activation up-regulates the expression of miR-146a, which in turn down-regulates NF-κB activity, at least partly through repressing the NF-κB signaling transducers TRAF6 and IRAK1. Thus, our results identify miR-146a as an important new member of the negative feedback loop that controls TCR signaling to NF-κB. Our findings also add microRNA to the list of regulators that control the resolution of T cell responses.
The coding genome of splenic marginal zone lymphoma: activation of NOTCH2 and other pathways regulating marginal zone development
Authors: Rossi Davide , Trifonov Vladimir , Fangazio Marco , Bruscaggin Alessio , Rasi Silvia , Spina Valeria , Monti Sara , Vaisitti Tiziana , Arruga Francesca , Famà Rosella , Ciardullo Carmela , Greco Mariangela , Cresta Stefania , Piranda Daniela , Holmes Antony , Fabbri Giulia , Messina Monica , Rinaldi Andrea , Wang Jiguang , Agostinelli Claudio , Piccaluga Pier Paolo , Lucioni Marco , Tabbò Fabrizio , Serra Roberto , Franceschetti Silvia , Deambrogi Clara , Daniele Giulia , Gattei Valter , Marasca Roberto , Facchetti Fabio , Arcaini Luca , Inghirami Giorgio , Bertoni Francesco , Pileri Stefano A. , Deaglio Silvia , Foà Robin , Dalla-Favera Riccardo , Pasqualucci Laura , Rabadan Raul , Gaidano Gianluca
Published: August 2012

Splenic marginal zone lymphoma (SMZL) is a B cell malignancy of unknown pathogenesis, and thus an orphan of targeted therapies. By integrating whole-exome sequencing and copy-number analysis, we show that the SMZL exome carries at least 30 nonsilent gene alterations. Mutations in NOTCH2, a gene required for marginal-zone (MZ) B cell development, represent the most frequent lesion in SMZL, accounting for ∼20% of cases. All NOTCH2 mutations are predicted to cause impaired degradation of the NOTCH2 protein by eliminating the C-terminal PEST domain, which is required for proteasomal recruitment. Among indolent B cell lymphoproliferative disorders, NOTCH2 mutations are restricted to SMZL, thus representing a potential diagnostic marker for this lymphoma type. In addition to NOTCH2, other modulators or members of the NOTCH pathway are recurrently targeted by genetic lesions in SMZL; these include NOTCH1, SPEN, and DTX1. We also noted mutations in other signaling pathways normally involved in MZ B cell development, suggesting that deregulation of MZ B cell development pathways plays a role in the pathogenesis of ∼60% SMZL. These findings have direct implications for the treatment of SMZL patients, given the availability of drugs that can target NOTCH, NF-κB, and other pathways deregulated in this disease.
Voltage-sensing domain mode shift is coupled to the activation gate by the N-terminal tail of hERG channels
Authors: Tan Peter S. , Perry Matthew D. , Ng Chai Ann , Vandenberg Jamie I. , Hill Adam P.
Published: August 2012

Human ether-a-go-go–related gene (hERG) potassium channels exhibit unique gating kinetics characterized by unusually slow activation and deactivation. The N terminus of the channel, which contains an amphipathic helix and an unstructured tail, has been shown to be involved in regulation of this slow deactivation. However, the mechanism of how this occurs and the connection between voltage-sensing domain (VSD) return and closing of the gate are unclear. To examine this relationship, we have used voltage-clamp fluorometry to simultaneously measure VSD motion and gate closure in N-terminally truncated constructs. We report that mode shifting of the hERG VSD results in a corresponding shift in the voltage-dependent equilibrium of channel closing and that at negative potentials, coupling of the mode-shifted VSD to the gate defines the rate of channel closure. Deletion of the first 25 aa from the N terminus of hERG does not alter mode shifting of the VSD but uncouples the shift from closure of the cytoplasmic gate. Based on these observations, we propose the N-terminal tail as an adaptor that couples voltage sensor return to gate closure to define slow deactivation gating in hERG channels. Furthermore, because the mode shift occurs on a time scale relevant to the cardiac action potential, we suggest a physiological role for this phenomenon in maximizing current flow through hERG channels during repolarization.
Impact of signaling microcompartment geometry on GPCR dynamics in live retinal photoreceptors
Authors: Najafi Mehdi , Haeri Mohammad , Knox Barry E. , Schiesser William E. , Calvert Peter D.
Published: August 2012

G protein–coupled receptor (GPCR) cascades rely on membrane protein diffusion for signaling and are generally found in spatially constrained subcellular microcompartments. How the geometry of these microcompartments impacts cascade activities, however, is not understood, primarily because of the inability of current live cell–imaging technologies to resolve these small structures. Here, we examine the dynamics of the GPCR rhodopsin within discrete signaling microcompartments of live photoreceptors using a novel high resolution approach. Rhodopsin fused to green fluorescent protein variants, either enhanced green fluorescent protein (EGFP) or the photoactivatable PAGFP (Rho-E/PAGFP), was expressed transgenically in Xenopus laevis rod photoreceptors, and the geometries of light signaling microcompartments formed by lamellar disc membranes and their incisure clefts were resolved by confocal imaging. Multiphoton fluorescence relaxation after photoconversion experiments were then performed with a Ti–sapphire laser focused to the diffraction limit, which produced small sub–cubic micrometer volumes of photoconverted molecules within the discrete microcompartments. A model of molecular diffusion was developed that allows the geometry of the particular compartment being examined to be specified. This was used to interpret the experimental results. Using this unique approach, we showed that rhodopsin mobility across the disc surface was highly heterogeneous. The overall relaxation of Rho-PAGFP fluorescence photoactivated within a microcompartment was biphasic, with a fast phase lasting several seconds and a slow phase of variable duration that required up to several minutes to reach equilibrium. Local Rho-EGFP diffusion within defined compartments was monotonic, however, with an effective lateral diffusion coefficient Dlat = 0.130 ± 0.012 µm2s−1. Comparison of rhodopsin-PAGFP relaxation time courses with model predictions revealed that microcompartment geometry alone may explain both fast local rhodopsin diffusion and its slow equilibration across the greater disc membrane. Our approach has for the first time allowed direct examination of GPCR dynamics within a live cell signaling microcompartment and a quantitative assessment of the impact of compartment geometry on GPCR activity.
Oxygen level: the dominant of resistive switching characteristics in cerium oxide thin films
Authors: Younis Adnan , Chu Dewei , Li Sean
Published: August 2012

Currently, resistive switching mechanisms in metal oxide thin films are not clearly understood due to lack of solid evidence. In this work, the switching behaviour of the Au/CeO2/conductive glass structure was analysed, where reproducible and pronounced resistive switching characteristics were obtained. The role of oxygen vacancies in switching characteristics was investigated. The concentration of oxygen vacancies in the CeO2 thin films was controlled by post-annealing and monitored by x-ray photon spectroscopy. The reduction in the switching ratio and the intensity of the peak associated with oxygen concentration O 1s level after annealing treatment confirmed the dominating role of oxygen vacancies in switching behaviour.
Electron temperature, ion density and energy influx measurements in a tubular plasma reactor for powder surface modification
Authors: Roth C , Oberbossel G , Rohr P Rudolf von
Published: August 2012

The tubular plasma reactor was designed for the continuous surface modification of fine powders in non-equilibrium RF discharges. So far, little has been known about the plasma characteristics of this inductively coupled reactor system. Therefore, moderate pressure argon–oxygen discharges, commonly used for powder processing, are investigated with tailor-made probe techniques. The influence of plasma power, system pressure, gas composition and mean gas velocity on the axial profiles of plasma parameters was studied. Electron temperature and positive ion density profiles were measured with a Langmuir double probe and the energy influx due to the plasma was determined by a new type of calorimetric probe. The limits for the E–H-mode transition are provided and photographs of the discharge are presented to illustrate the relationship between process parameters and plasma characteristics. Both, ion density and energy influx increased with rising plasma power. The axial energy influx profiles were in addition strongly influenced by the mean gas velocity. Based on these profiles the maximum transient particle temperature was calculated as a function of the particle diameter. Particle temperatures in the order of 100 °C were estimated, whereas the thermal load of the substrates rises with increasing plasma power, residence time and pressure.
Fiber texturing in nano-crystalline TiO2 thin films deposited at 150 °C by dc-reactive sputtering on fiber-textured [0 0 0 1] ZnO : Al substrates
Authors: Pellegrino Giovanna , Bongiorno Corrado , Ravesi Sebastiano , Alberti Alessandra
Published: August 2012

TiO2 thin films were deposited at an effective surface temperature of 150 °C by dc-reactive magnetron sputtering on ZnO : Al oriented substrates having a fiber texture along the [0 0 0 1] axis, and studied by transmission electron microscopy and x-ray diffraction analyses. The substrate texturing was used to tailor the TiO2 structure in such a way that a porous matrix made of anatase nano-grains (10 nm in diameter) is formed instead of an amorphous layer (as observed at 150 °C on glass). Additionally, we demonstrate that, by adding an ex situ 200 °C annealing, the anatase domains also gain a fiber texture with the axes aligned to that of the substrate. The TiO2/AZO structural coupling is expected to play a crucial role for the carrier transport through the interface as required in dye-sensitized solar cells. Moreover, the low temperatures used render the process compatible with commonly used plastics substrates.
Thermal evaporation and x-ray photostability of dodecyl-passivated silicon nanoparticles
Authors: Coxon Paul R , Ashby Shane P , Frogley Mark D , Chao Yimin
Published: August 2012

X-ray photoelectron spectroscopy (XPS) and x-ray absorption spectroscopy have been used to study the makeup of thin films of 6.5 nm diameter dodecyl-capped silicon nanoparticles (SiNPs) formed in a one-pot synthesis method of micelle reduction. Thermostability measurements show the SiNPs undergo thermal desorption at ∼240 °C, a higher temperature than for SiNPs capped by shorter hydrocarbon layers owing to the greater size of the nanoparticle system in this case. Suspensions of SiNPs are found to evaporate in a UHV environment intact with the hydrocarbon passivating layer preserved and form thin films which are visualized with microimaging FTIR spectroscopy. The stability of the capping layer within thick SiNP films under extended exposure (up to 2160 s) to 140 eV photons has been examined where XPS spectra show the breakdown of the passivating layer allowing the underlying silicon core to undergo subsequent oxidation.
Structural Characterization of Arabidopsis Leaf Arabinogalactan Polysaccharides
Authors: Tryfona Theodora , Liang Hui-Chung , Kotake Toshihisa , Tsumuraya Yoichi , Stephens Elaine , Dupree Paul
Published: August 2012

Proteins decorated with arabinogalactan (AG) have important roles in cell wall structure and plant development, yet the structure and biosynthesis of this polysaccharide are poorly understood. To facilitate the analysis of biosynthetic mutants, water-extractable arabinogalactan proteins (AGPs) were isolated from the leaves of Arabidopsis (Arabidopsis thaliana) plants and the structure of the AG carbohydrate component was studied. Enzymes able to hydrolyze specifically AG were utilized to release AG oligosaccharides. The released oligosaccharides were characterized by high-energy matrix-assisted laser desorption ionization-collision-induced dissociation mass spectrometry and polysaccharide analysis by carbohydrate gel electrophoresis. The Arabidopsis AG is composed of a β-(1→3)-galactan backbone with β-(1→6)-d-galactan side chains. The β-(1→6)-galactan side chains vary in length from one to over 20 galactosyl residues, and they are partly substituted with single α-(1→3)-l-arabinofuranosyl residues. Additionally, a substantial proportion of the β-(1→6)-galactan side chain oligosaccharides are substituted at the nonreducing termini with single 4-O-methyl-glucuronosyl residues via β-(1→6)-linkages. The β-(1→6)-galactan side chains are occasionally substituted with α-l-fucosyl. In the fucose-deficient murus1 mutant, AGPs lack these fucose modifications. This work demonstrates that Arabidopsis mutants in AGP structure can be identified and characterized. The detailed structural elucidation of the AG polysaccharides from the leaves of Arabidopsis is essential for insights into the structure-function relationships of these molecules and will assist studies on their biosynthesis.
Survival of theAfrican white‐backed vultureGyps africanusin north‐easternSouthAfrica
Authors: Monadjem Ara , Botha Andre , Murn Campbell
Published: August 2012

Old World vultures are in decline across their entire range. Although critical for the formulation of effective conservation measures, neither survival nor movement patterns of African vultures are adequately known. This paper presents survival and movement data on theAfrican white‐backed vultures (Gyps africanus) fromSouthAfrica. Survival estimates were modelled on resightings of tagged vultures. Birds were captureden masseand resighted betweenNovember 2005 andDecember 2010. A total of 93 adult and subadult birds were fitted with uniquely numbered patagial tags, which were resighted 3707 times(mean of 39.8 resightings per bird). The programmeMARKwas used to estimate survival. The best model was one where survival and recaptures varied only with time (e.g. year). However, owing to the fading (illegibility) of tags in later years, the relationship with time is probably spurious. The second best model was one where survival and recaptures varied with age and time. Annual survival estimates increased from 85.2% in second‐year birds to 99.9% in adults. This corresponds well with the survival of two otherGypsvultures that have been studied to date and underscores the point that additional mortality of adults in these long‐lived species will result in rapid population declines.
The Thyroid – too much and too little across the ages. The consequences of subclinical thyroid dysfunction
Authors: Franklyn Jayne A.
Published: August 2012

Mild thyroid dysfunction is common, and more prevalent than overt hyper‐ and hypothyroidism. Subclinical (mild) thyroid dysfunction is a biochemical entity characterized by an abnormality of serum TSH associated with normal serum thyroid hormone concentrations. Subclinical hyperthyroidism is thus defined as low or suppressed serum TSH with normal serum‐free T4 and T3, while subclinical hypothyroidism is defined as raised serum TSH with normal circulating T4. These biochemical abnormalities are part of the much wider spectrum of thyroid dysfunction which includes overt hyperthyroidism and overt hypothyroidism, but by no means always indicate underlying thyroid disease. There is much debate about the significance of mild abnormalities of thyroid function in terms of symptoms and potential associations with long‐term morbidity and mortality and hence much debate about whether to screen for these abnormalities, and, once identified, whether to treat or monitor, and if so, how? Our knowledge base has increased significantly in recent years, principally because studies of large cohorts have begun to define the epidemiology and associations of mild thyroid dysfunction (including short‐term and long‐term outcomes) and a small but increasing number of randomized‐controlled intervention studies have been reported. There is, however, much to learn about these disorders and, given their prevalence, their impact on health.
HTLV‐1‐associated infective dermatitis: updates on the pathogenesis
Authors: McGill Neilia‐Kay , Vyas Jui , Shimauchi Takatoshi , Tokura Yoshiki , Piguet Vincent
Published: August 2012

HTLV‐1‐associated infective dermatitis (HAID) is the main paediatric manifestation of human T‐cell lymphotropic virus type 1 (HTLV‐1). It is characterised by a chronic exudative eczematous eruption and persistent infection with Staphylococcus aureus (SA) and beta‐haemolytic streptococci (BHS). Prevalence is highest in the Caribbean and Brazil; however, cases have been reported in other HTLV‐1 endemic regions. Approximately 20 million people worldwide are infected with HTLV‐1 and only 5–10% suffer from disease. Other manifestations include adult T‐cell leukaemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV‐1‐associated myelopathy (TSP/HAM). HAID may also progress to ATLL or TSP/HAM. Treatment options are limited to prolonged antibiotic therapy. The aim of this paper is to review existing evidence and propose new theories on the pathogenesis of HAID. The current view is that HTLV‐1 infection is required and in susceptible individuals leads to immune dysregulation with subsequent immunosuppression and superinfection with SA and BHS. Evidence suggests that host, environment and genetic factors may play a causative role. Genetic factors within ethnic groups determine host immune response and carrier state or disease manifestation of HTLV‐1 infection. Increased IgE levels may contribute to the SA and BHS superinfection in HAID. Additionally, the possible impact of filaggrin, skin proteinase dysregulation, Langerhans cell dysfunction and TH2 chemokines is highlighted. More than 45 years since the discovery of HAID, the exact pathogenesis is still not fully understood. Further research is still needed to clearly elucidate the exact pathogenic mechanism of HAID.
Lack of microRNA miR‐150 reduces the capacity of epidermal Langerhans cell cross‐presentation
Authors: Mi Qing‐Sheng , Xu Ying‐Ping , Qi Rui‐Qun , Shi Yu‐Ling , Zhou Li
Published: August 2012

MicroRNAs (miRNAs) are evolutionarily conserved small non‐coding RNAs that repress target genes at post‐transcriptional level. Langerhans cells (LCs) are skin‐residential dendritic cells (DCs) with a life cycle distinct from other types of DCs. miRNA deficiency interrupts the homoeostasis and function of epidermal LCs, suggesting the critical roles of miRNAs in LC development and function. However, the roles of individual miRNAs in regulating LC development and function remain completely unknown. MiRNA miR‐150 is highly expressed in mature lymphocytes and regulates T‐ and B‐cell development and function. Here, we reported that miR‐150 is also expressed in epidermal LCs, and its expression is significantly down‐regulated during in vitro LC maturation. Using a miR‐150 knockout mouse model, we found that lack of miR‐150 reduces the capacity of LCs to cross‐present a soluble antigen to antigen‐specific CD8+ T cells, but does not disturb the development, maturation, migration and phagocytic capacity of LCs. Thus, our data indicate that miR‐150 is required for LC cross‐presentation.
Winter cold tolerance and the geographic range separation of Bromus tectorum and Bromus rubens, two severe invasive species in North America
Authors: Bykova Olga , Sage Rowan F.
Published: August 2012

The invasive grasses Bromus rubens and Bromus tectorum are responsible for widespread damage to semiarid biomes of western North America. Bromus. tectorum dominates higher and more northern landscapes than its sister species B. rubens, which is a severe invader in the Mojave desert region of the American Southwest. To assess climate thresholds controlling their distinct geographic ranges, we evaluated the winter cold tolerance of B. tectorum and B. rubens. Freezing tolerance thresholds were determined using electrolyte leakage and whole‐plant mortality. The responses of the two species to winter cold and artificial freezing treatments were similar in 2007–2008 and 2009–2010. When grown at minimum temperatures of 10 °C, plants of both species had cold tolerance thresholds near −10 °C, while plants acclimated to a daily minimum of −10 to −30 °C survived temperatures down to −31 °C. In the winter of 2010–2011, a sudden severe cold event on December 9, 2010 killed all B. rubens populations, while B. tectorum was not harmed; all tested plants were 7–8 weeks old. Controlled acclimation experiments demonstrated that 8‐week‐old plants of B. rubens had a slower acclimation rate to subzero temperatures than B. tectorum and could not survive a rapid temperature drop from 1 to −14 °C. Four‐month‐old B. rubens populations were as cold tolerant as B. tectorum. Our results show that severe and sudden freeze events in late autumn can kill young plants of B. rubens but not B. tectorum. Such events could exclude B. rubens from the relatively cold, Intermountain steppe biome of western North America where B. tectorum predominates.
Natural pipes in blanket peatlands: major point sources for the release of carbon to the aquatic system
Authors: Holden Joseph , Smart Richard P. , Dinsmore Kerry J. , Baird Andy J. , Billett Mike F. , Chapman Pippa J.
Published: August 2012

Natural soil pipes, which have been widely reported in peatlands, have been shown to contribute significantly to total stream flow. Here, using measurements from eight pipe outlets, we consider the role of natural pipes in the transport of fluvial carbon within a 17.4‐ha blanket‐peat‐covered catchment. Concentrations of dissolved and particulate organic carbon (DOC and POC) from pipe waters varied greatly between pipes and over time, ranging between 5.3 and 180.6 mg L−1 for DOC and 0.08 and 220 mg L−1 for POC. Pipes were important pathways for peatland fluvial carbon export, with fluxes varying between 0.6 and 67.8 kg yr−1 (DOC) and 0.1 and 14.4 kg yr−1 (POC) for individual pipes. Pipe DOC flux was equivalent to 20% of the annual DOC flux from the stream outlet while the POC flux from pipes was equivalent to 56% of the annual stream POC flux. The proportion of different forms of aquatic carbon to total aquatic carbon flux varied between pipes, with DOC ranging between 80.0% and 91.2%, POC from 3.6% to 17.1%, dissolved CO2‐C from 2.4% to 11.1% and dissolved CH4‐C from 0.004% to 1.3%. The total flux of dissolved CO2‐C and CH4‐C scaled up to all pipe outlets in the study catchment was estimated to be 89.4 and 3.6 kg yr−1 respectively. Overall, pipe outlets produced discharge equivalent to 14% of the discharge in the stream but delivered an amount of aquatic carbon equivalent to 22% of the aquatic carbon flux at the catchment outlet. Pipe densities in blanket peatlands are known to increase when peat is affected by drainage or drying. Hence, environmental change in many peatlands may lead to an increase in aquatic carbon fluxes from natural pipes, thereby influencing the peatland carbon balance and downstream ecological processes.
Yam tuber mucilage as a candidate substance for saliva substitute: in vitro study of its viscosity and influences on lysozyme and peroxidase activities
Authors: Kho Hong‐Seop , Park Moon‐Soo , Chang Ji‐Youn , Kim Yoon‐Young
Published: August 2012

Objective

To investigate the viscosity of yam tuber mucilage (YTM) and its effects on lysozyme and peroxidase activities in solution phase and on surface phase.

Methods

Two kinds of YTM were extracted, one containing both protein and carbohydrate and the other containing mainly carbohydrate. Hen egg‐white lysozyme and bovine lactoperoxidase were used as lysozyme and peroxidase sources, respectively. Viscosity was measured with a cone‐and‐plate digital viscometer. Lysozyme activity was determined using the turbidimetric method, and peroxidase activity was determined using the NbsSCN assay. Hydroxyapatite beads were used as a solid phase.

Results

The viscosity values of YTM followed a pattern of a non‐Newtonian fluid. The carbohydrate concentration affected the viscosity values at all shear rates, while the protein concentration affected the viscosity values at low shear rates. It could be suggested that YTM composed of 1.0 mg/ml protein and 1.0 mg/ml carbohydrate has viscosity values similar to those of unstimulated whole saliva at shear rates present at routine oral functions. Hydroxyapatite‐adsorbed YTM significantly increased the adsorption and subsequent enzymatic activities of lysozyme, but not those of peroxidase.

Conclusions

Yam tuber mucilage has viscoelastic properties similar to those of human saliva and enhances the enzymatic activity of lysozyme on hydroxyapatite surfaces.
Protection conferred by heterologous vaccination against tuberculosis is dependent on the ratio of CD4+/CD4+ Foxp3+ cells
Authors: Fedatto Paola Fernanda , Sérgio Cássia Alves , Paula Marina Oliveira e , Gembre Ana Flávia , Franco Luís Henrique , Wowk Pryscilla Fanini , Ramos Simone Gusmão , Horn Cynthia , Marchal Gilles , Turato Walter Miguel , Silva Célio Lopes , da Fonseca Denise Morais , Bonato Vânia Luiza Deperon
Published: August 2012

CD4+ Foxp3+ regulatory T cells inhibit the production of interferon‐γ, which is the major mediator of protection against Mycobacterium tuberculosis infection. In this study, we evaluated whether the protection conferred by three different vaccines against tuberculosis was associated with the number of spleen and lung regulatory T cells. We observed that after homologous immunization with the 65 000 molecular weight heat‐shock protein (hsp 65) DNA vaccine, there was a significantly higher number of spleen CD4+ Foxp3+ cells compared with non‐immunized mice. Heterologous immunization using bacillus Calmette–Guérin (BCG) to prime and DNA‐hsp 65 to boost (BCG/DNA‐hsp 65) or BCG to prime and culture filtrate proteins (CFP)‐CpG to boost (BCG/CFP‐CpG) induced a significantly higher ratio of spleen CD4+/CD4+ Foxp3+ cells compared with non‐immunized mice. In addition, the protection conferred by either the BCG/DNA‐hsp 65 or the BCG/CFP‐CpG vaccines was significant compared with the DNA‐hsp 65 vaccine. Despite the higher ratio of spleen CD4+/CD4+ Foxp3+ cells found in BCG/DNA‐hsp 65‐immunized or BCG/CFP‐CpG‐immunized mice, the lungs of both groups of mice were better preserved than those of DNA‐hsp 65‐immunized mice. These results confirm the protective efficacy of BCG/DNA‐hsp 65 and BCG/CFP‐CpG heterologous prime‐boost vaccines and the DNA‐hsp 65 homologous vaccine. Additionally, the prime‐boost regimens assayed here represent a promising strategy for the development of new vaccines to protect against tuberculosis because they probably induce a proper ratio of CD4+ and regulatory (CD4+ Foxp3+) cells during the immunization regimen. In this study, this ratio was associated with a reduced number of regulatory cells and no injury to the lungs.
Clinical characteristics of norovirus gastroenteritis among hospitalized children in Japan
Authors: Kawada Jun‐Ichi , Arai Naoko , Nishimura Naoko , Suzuki Michio , Ohta Rieko , Ozaki Takao , Ito Yoshinori
Published: August 2012

Acute diarrhea is one of commonest pediatric illnesses worldwide. Although the importance of norovirus as a cause of gastroenteritis outbreaks is well documented, its role in sporadic acute gastroenteritis is not well characterized. The aim of this study was to clarify the prevalence and clinical characteristics of norovirus gastroenteritis among hospitalized children. Between November 2007 and April 2008, inpatients under 12 years of age with acute gastroenteritis in a single hospital in Japan were investigated. A stool sample from each patient was screened for enteropathogenic bacteria and tested by reverse transcription polymerase reaction for norovirus and by an immunochromatographic method for rotavirus and enteric adenoviruses. The clinical features of children with norovirus gastroenteritis were compared with those of children with rotavirus and children without noro‐ or rotovirus infections. Among 107 patients included in this study, norovirus and rotavirus were detected in 36 (34%) and 37 (35%) patients, respectively. Compared with rotavirus enteritis, the duration of vomiting and diarrhea was significantly longer, and serum C‐reactive protein concentrations were higher, in patients with norovirus enteritis. Norovirus was detected as frequently as rotavirus in hospitalized pediatric gastroenteritis patients. Our results suggest that norovirus gastroenteritis among hospitalized young children is not less severe than rotavirus gastroenteritis.
Effectiveness of stop‐smoking medications: findings from the International Tobacco Control (ITC) Four Country Survey
Authors: Kasza Karin A. , Hyland Andrew J. , Borland Ron , McNeill Ann D. , Bansal‐Travers Maansi , Fix Brian V. , Hammond David , Fong Geoffrey T. , Cummings K. Michael
Published: August 2012

Aim

To evaluate the population effectiveness of stop‐smoking medications while accounting for potential recall bias by controlling for quit attempt recency.

Design

Prospective cohort survey.

Setting

United Kingdom, Canada, Australia and the United States.

Participants

A total of 7436 adult smokers (18+ years) selected via random digit dialling and interviewed as part of the International Tobacco Control Four Country Survey (ITC‐4) between 2002 and 2009. Primary analyses utilized the subset of respondents who participated in 2006 or later (n = 2550).

Measurements

Continuous abstinence from smoking for 1 month/6 months.

Findings

Among participants who recalled making a quit attempt within 1 month of interview, those who reported using varenicline, bupropion or nicotine patch were more likely to maintain 6‐month continuous abstinence from smoking compared to those who attempted to quit without medication [adjusted odds ratio (OR) 5.84, 95% confidence interval (CI) (2.12–16.12), 3.94 (0.87–17.80), 4.09 (1.72–9.74), respectively]; there were no clear effects for oral NRT use. Those who did not use any medication when attempting to quit tended to be younger, to be racial/ethnic minorities, to have lower incomes and to believe that medications do not make quitting easier.

Conclusions

Consistent with evidence from randomized controlled trials, smokers in the United Kingdom, Canada, Australia and the United States are more likely to succeed in quit attempts if they use varenicline, bupropion or nicotine patch. Previous population studies that failed to find an effect failed to control adequately for important sources of bias.
Longing to belong: children in residential care and their experiences of peer relationships at school and in the children's home
Authors: Emond Ruth
Published: August 2012

Resilience literature has stressed the potential of both children's educational experiences and their friendships to act as protective factors against adversity. However, less is known about how children living with adversity navigate these ‘everyday’ aspects of social terrain and the particular challenges that they face. This paper explores the meaning and experience of peer relationships to one group of children living in residential care in Ireland. Drawing on a larger study of school and care, it explores data gathered from 16 children, aged 8 to 18, who were living in eight different children's homes on the east coast of Ireland. The findings suggest that the children were acutely aware of their ‘care’ status and developed a number of strategies to manage this identity in school. It appears that more often than not, children described being left to their own devises to manage friendships and peer relationships. Thus, despite being a crucial source of both stress and support, peer relationships did not appear to be regarded as an issue that adults should be involved with. This raises questions for practice about what children should be supported with and the way in which peer relationships are potentially overlooked by social work, residential and school staff.
Two‐generation preschool programme: immediate and 7‐year‐old outcomes for low‐income children and their parents
Authors: Benzies Karen , Mychasiuk Richelle , Kurilova Jana , Tough Suzanne , Edwards Nancy , Donnelly Carlene
Published: August 2012

Preschool children living in low‐income families are at increased risk for poor outcomes; early intervention programmes mitigate these risks. While there is considerable evidence of the effectiveness of centre‐based programmes in other jurisdictions, there is limited research about Canadian programmes, specifically programmes that include children and parents. The purpose of this study was to evaluate a single‐site, two‐generation preschool demonstration programme for low‐income families in Canada. A single group, pre‐test (programme intake) /post‐test (programme exit) design with a 7‐year‐old follow‐up was used. Between intake and exit, significant improvements in receptive language and global development were found among the children, and significant improvements in self‐esteem, use of community resources, parenting stress and risk for child maltreatment were found among the parents. These positive improvements were sustained until the children were 7 years old. Public investment in two‐generation preschool programmes may mitigate risks for suboptimal child development and improve parental psychosocial outcomes.
Renal tubular acidosis type IV in hyperkalaemic patients – a fairy tale or reality?
Authors: Haas Christian S. , Pohlenz Inga , Lindner Ulrich , Muck Philip M. , Arand Jovana , Suefke Sven , Lehnert Hendrik
Published: August 2012

Objective

Hyperkalaemia is a common feature in hospitalized patients and often attributed to drugs antagonizing the renin‐angiotensin‐aldosterone system (RAAS) and/or acute kidney injury (AKI), despite significantly preserved glomerular filtration rate (GFR). The objective of this study was to determine the prevalence and role of renal tubular acidosis type IV (RTA IV) in the development of significant hyperkalaemia.

Design

A single‐centre retrospective study.

Patients

Patients admitted to a University Hospital over 12 months.

Measurements

Patients with a potassium value > 6·0 mm were identified. Clinical and laboratory data were revisited, and patients with a normal anion gap metabolic acidosis were evaluated for the existence of RTA IV.

Results

A total of 57 patients having significant hyperkalaemia (>6·0 mm) were identified. Twelve patients had end‐stage renal disease, while 21 patients had solely AKI or progressive chronic renal failure. RTA IV was present in 24 patients (42%), of whom 71% had pre‐existing renal insufficiency because of diabetic nephropathy or tubulointerstitial nephritis. All hyperkalaemic patients with urinary/serum electrolytes suggestive of RTA IV had evidence of AKI, but creatinine levels were significantly lower (P < 0·05), while the number of drugs antagonizing the RAAS was comparable.

Conclusion

We demonstrated that RTA IV (i) is very common in patients with hyperkalaemia; (ii) should always be suspected in hyperkalaemic patients with only moderately impaired GFR; and (iii) may result in significant hyperkalaemia in the presence of both AKI and drugs antagonizing the RAAS.
Plasma Lp‐PLA2 mass and apoB‐lipoproteins that carry Lp‐PLA2 decrease after sodium
Authors: Constantinides Alexander , Kerstens Michiel N. , Dikkeschei Bert D. , van Pelt L. Joost , Tellis Constantinos C. , Tselepis Alexandros D. , Dullaart Robin P. F.
Published: August 2012

Eur J Clin Invest 2012; 42 (11): 1235–1243

Background  Lipoprotein‐associated phospholipase A2 (Lp‐PLA2) is a novel cardiovascular risk marker, which is predominantly complexed to apolipoprotein (apo) B‐containing lipoproteins in human plasma. As increasing dietary sodium intake may decrease plasma apoB‐containing lipoproteins, we tested whether a sodium challenge lowers plasma Lp‐PLA2 mass, as well as the levels of apoB‐containing lipoprotein particles carrying Lp‐PLA2 (apoB‐Lp‐PLA2), employing a newly developed enzyme‐linked immunosorbent assay.

Materials and methods  In 45 women and 31 men (mean age 44 ± 14 years), plasma Lp‐PLA2 mass (turbidimetric immunoassay), the level of apoB‐Lp‐PLA2, expressed in apoB concentration and lipoproteins were measured in response to a 3‐day challenge with 9 g sodium chloride tablets daily.

Results  Urinary sodium excretion increased from 165 ± 60 to 321 ± 70 mmol/24 h (P < 0·001) after salt loading. Plasma Lp‐PLA2 mass decreased from 618 (493–719) to 588 (465–698) μg/L (P < 0·001), and apoB‐Lp‐PLA2 decreased from 0·276 (0·200–0·351) to 0·256 (0·189–0·328) g LDL protein/L (P = 0·004) in response to the sodium challenge together with decreases in plasma total cholesterol, nonhigh‐density lipoprotein (HDL) cholesterol, low‐density lipoprotein (LDL) cholesterol, apolipoprotein B and the total cholesterol/HDL cholesterol ratio (P < 0·01 for all). Changes in plasma Lp‐PLA2 mass were correlated positively with changes in total cholesterol, LDL cholesterol and non‐HDL cholesterol (r = 0·260–0·276, P < 0·05 to P < 0·02), whereas changes in apoB‐Lp‐PLA2 were correlated positively with changes in non‐HDL cholesterol and in the total cholesterol/HDL cholesterol ratio (r = 0·232–0·385, P < 0·05–0·01).

Conclusion  Both plasma Lp‐PLA2 mass levels and apoB‐Lp‐PLA2 decrease in response to a short‐term oral sodium challenge.
Choice of selectivity coefficients for cation exchange using principal components analysis and bootstrap anova of coefficients of variation
Authors: Visconti F. , De Paz J. M. , Rubio J. L.
Published: August 2012

Modellers of the exchange of sodium, potassium, calcium and magnesium in soils have to choose from up to six different equations based on the mass action law paradigm (mainly Gapon, Vanselow, Gaines‐Thomas and Kerr) and up to six different binary cation combinations. In this article a methodology to choose the most appropriate equation and binary cation combinations is presented. The combination of six equations with six binary cation combinations resulted in 36 selectivity coefficients. Each one of these was assessed for 133 calcareous illitic soil samples. Six principal components analyses (PCA) were carried out to find out which three binary cation combinations accounted most for the variance of the soil exchange selectivity. Then a bootstrap anova and multiple comparison (MC) procedure with orthogonal contrasts were carried out to compare the coefficients of variation of the selectivity coefficients calculated with each equation. According to the PCA, the three binary cation combinations involving calcium, and expressed with whichever of the equations of Kerr, Vanselow and Gaines‐Thomas, accounted most efficiently for the variance of the soil exchange selectivity. According to the bootstrap anova and MC analysis, the Gapon equations, either in analytical concentrations or activities of aqueous cations, provide significantly larger coefficients of variation than the equations of Kerr (either in analytical concentrations or activities of aqueous cations), Vanselow and Gaines‐Thomas. The use of the Kerr, Vanselow or Gaines‐Thomas equations and the three binary cation combinations involving calcium resulted in the most effective way of modelling the exchange equilibria of sodium, potassium, calcium and magnesium in calcareous illitic soils.
Gradients in fracture force and grazing resistance across canopy layers in seven tropical grass species
Authors: Jacobs A. A. A. , Scheper J. A. , Benvenutti M. A. , Gordon I. J. , Poppi D. P. , Elgersma A.
Published: August 2012

In reproductive swards, stems can act as a barrier that affects the grazing behaviour of ruminant livestock. The barrier effect of stems is closely associated with both the force required to fracture the stems and the density of these stems (in combination, these make up grazing resistance), and these factors need to be considered when making predictions about the forage intake of ruminants grazing reproductive pastures. Differences in grazing resistance between sward canopy layers of different grass species are thought to affect bite dimensions, but data are scarce. In this study, we assessed the grazing resistance for three canopy layers of seven tropical grass species. Species differed significantly in grazing resistance for every canopy layer, with a general ranking order for grazing resistance, in ascending order: Cenchrus ciliaris (‘American' buffel), Digitaria milanjiana (‘Jarra’ finger grass), Setaria surgens (annual pigeon grass), Setaria sphacelata (‘Narok’ setaria), Dichanthium sericeum (Queensland bluegrass), Chloris gayana (‘Callide’ Rhodes grass). In the top canopy layer, grazing resistance did not appear to create a barrier for any of the species, but in the bottom canopy layer, it did for all species. Species also differed in the relative contribution of fracture force and density to grazing resistance. The results highlight the importance of managing the grazing systems to minimize the barrier effect of the stems, which can be done by controlling the phenological stage of the pasture and the grass species and animal size used in the system.
The effect of postharvest handling and processing on sea urchin (Evechinus chloroticus) gonad quality
Authors: Verachia Wasseela , Niven Brian , Bremer Philip J.
Published: August 2012

Sea urchin gonads also known as roe or uni are a high‐valued food, considered a delicacy in many parts of the world. To determine the impact of stress caused by exposure of live urchins to air on the subsequent shelf‐life of recovered gonads, urchins (Evechinus chloroticus) were held in air at either 4 °C for 144 h or 15 °C for 72h. The coelomic fluid of urchins held in air showed a decrease in pH and increase in lactic acid concentration, percentage solid, turbidity level, colour and coelomocyte numbers. Gonads recovered from urchins held in air exhibited enhanced rates of deterioration over time, as assessed by a loss of surface definition and a decrease in their water‐holding capacity and height‐to‐surface ratio (melting). Gonad deterioration was minimised by implementing a brine + alum wash upon immediate removal of gonads from live urchins. This research has shown that the manner in which live urchins are held and processed has a dramatic impact on the subsequent shelf‐life and quality of the recovered gonads.
Effect of thermal treatment on the characteristic properties of loach peptide
Authors: You Lijun , Zheng Lin , Regenstein Joe M. , Zhao Mouming , Liu Dong
Published: August 2012

The effects of thermal treatment on the changes in the colour, the molecular weight distribution, amino acid profiles and the overall antioxidant activities of loach peptide were investigated. When the thermal temperature was rising, the browning was enhanced. The contents of free amino acids Gly, Arg, Thr and Tyr were increased, whereas those of Asp, Ser, Met, Cys, Trp and Lys were decreased. The scavenging activities (1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activity, the oxygen radical absorbance capacity (ORAC) and the reducing power of loach peptides after different thermal treatments were lower than those of the control, whereas the Cu2+ chelating activity was higher (except from the sample treated at 100 °C, 20 min). The heat treatment at 121 °C, 15 min was shown to be the best thermal processing, as it caused the least loss in radical scavenging activity and showed relatively higher Cu2+ chelating activity.