bluuebunny/crossref_metadata_2025 huggingface dataset:
The Lifeworlds of Organic and Conventional Farmers in Central‐southern England: A Phenomenological Enquiry
Authors: Kings David , Ilbery Brian
Published: April 2014

Little comparative research has investigated the ‘lifeworlds’ of organic and conventional farmers. Using phenomenology, this article explores and describes the ‘lifeworlds’ of farmers in central‐southern England with the aim of identifying their understandings and experiences in relation to their choice of farming system. On‐farm ‘lifeworld’ interviews and observations (examined in terms of movement, rest and encounter) showed that, in contrast to conventional farmers, organic farmers often have less tidy farms, perceive the farm and ‘natural’ environment as one and the same, place more importance on their dwelling and experience greater feelings of isolation. Most of the organic respondents' understandings of farming were more closely linked to the ‘natural’ environment, biodiversity and agricultural sustainability than the conventional farmers, whose agricultural understandings were often concerned with creating pheasant cover and providing ‘good environments’ for foxes.
Regulation of Personal Social Services – TheIsraeli Experience
Authors: Lahat Lihi , Talit Gal
Published: April 2014

The current article explores the aspects of regulatory policy in the field of personal social services. InIsrael, the government sets standards, and finances and oversees personal social services, while the services themselves are provided primarily by non‐governmental organizations. Based on a qualitative study we examined two questions. First, what characterizes the implementation of regulatory mechanisms in the field of personal social services inIsrael? Second, how can we explain the outcomes of regulation in the personal social services inIsrael? In a unique approach, we used the institutional analysis and development (IAD) framework to explore the regulatory practices implemented in community residences and hostels for people with intellectual disabilities and in after school programmes. The findings revealed that although there were implementation gaps in both cases, theIADmight improve our understanding of the nature and magnitude of these gaps. Furthermore, the insights gained may have implications for policymakers in their development of regulatory policy.
Soil dispersion tests combined with topographical information can describe field‐scale sediment and phosphorus losses
Authors: Villa A. , Djodjic F. , Bergström L.
Published: April 2014

Methods for estimating sediment and phosphorus (P) transfer from agricultural land to surface waters are needed to mitigate their adverse impact on water quality. This study quantified sediment and P losses from five agricultural fields and evaluated the patterns observed based on the intrinsic risk of sediment and P mobilization from the soil, together with field topographical and hydrological data. The mobilization risk was estimated using the environmental soil dispersion test DESPRAL. High‐resolution LiDAR elevation data and crop management data were used to describe transport and delivery of the material mobilized. Annual flow‐weighted suspended solids (SS) concentration in drainage water ranged from 48 to 374 mg/L, total P (TP) from 0.12 to 0.39 mg/L and unreactive P (UP) from 0.08 to 0.33 mg/L. The mobilization risk, measured as turbidity in the aliquot recovered from the dispersion test, varied from 781 to 2310 nephelometric turbidity units (NTU). The method proved to be efficient in describing and differentiating sediment and P mobilization potential between fields. The topographical data also showed large differences between fields, with the length–slope (LS) parameter varying from 0.037 to 0.999. Based on assessments of source (mobilization risk) and transport factors (LS, crop management data), it was possible to characterize fields as favoured or limited in terms of source and transport and to explain the long‐term SS and P losses observed at field scale.
Lubrication Behavior of Binary Blends of Solvent Neutral-150: Polyalpholefin-100 and Solvent Neutral-150: Polyisobutene
Authors: Heidarzadeh Rizi Safieh , Semnani Abolfazl
Published: April 2014

Different blends containing 5%, 10%, 15%, 20%, 25%, and 30% of polyalphaolefin-100 (PAO-100) as a minor component and solvent neutral-150 (SN-150) as a major component were prepared. The important lubrication properties of the blends were then measured. The obtained results indicate that upon increasing the weight percentage of PAO-100, the viscosity index (VI) rises, the cold cranking simulator (CCS) diminishes, and viscosities approach the corresponding values due to solvent neutral-500 (SN-500). Different equations were derived between the viscosity and VI and weight percentage of PAO-100. A similar procedure was employed for blends containing 1%, 5%, 10%, 12%, and 15% of polyisobutene (PIB). In this case, results parallel to PAO-100 were obtained. The 30% PAO-100: SN-150 and 12% PIB: SN-150 mixtures were successfully employed for the equalization of semisynthetic engine oil SAE 20W50 API SJ from Millers Company. Biodegradability as well as tribotests were performed on the recent blends and compared with corresponding values due to SN-150.
Thermal Stress Analysis of a Railway Wheel in Sliding-Rolling Motion
Authors: Zwierczyk Péter T. , Váradi Károly
Published: April 2014

Our investigations aimed to model the thermal stress development between wheel and rail, caused by heat generation during braking, by coupled transient thermal and elastic-plastic FE simulations. Stresses are generated due to thermal expansion caused by local temperature rise and changes in temperature in case of one revolution of the wheel. Our investigations resulted in the fact that thermal expansion caused by heat generation and heat conduction induced considerable local stresses along the thread of the wheel ∼0.1–0.5 mm underneath the surface.
A Comprehensive Study of Vibration Signals for a Thin Shell Structure Using Enhanced Independent Component Analysis and Experimental Validation
Authors: Cheng Wei , He Zhengjia , Zhang Zhousuo
Published: April 2014

Vibration source information (source number, source waveforms, and source contributions) of gears, bearings, motors, and shafts is very important for machinery condition monitoring, fault diagnosis, and especially vibration monitoring and control. However, it has been a challenging to effectively extract the source information from the measured mixed vibration signals without a priori knowledge of the mixing mode and sources. In this paper, we propose source number estimation, source separation, and source contribution evaluation methods based on an enhanced independent component analysis (EICA). The effects of nonlinear mixing mode and different source number on source separation are studied with typical vibration signals, and the effectiveness of the proposed methods is validated by numerical case studies and experimental studies on a thin shell test bed. The conclusions show that the proposed methods have a high accuracy for thin shell structures. This research benefits for application of independent component analysis (ICA) to solve the vibration monitoring and control problems for thin shell structures and provides important references for machinery condition monitoring and fault diagnosis.
Laser Diagnostics of Plasma in Synthesis of Graphene-Based Materials
Authors: Tuesta Alfredo D. , Bhuiyan Aizaz , Lucht Robert P. , Fisher Timothy S.
Published: April 2014

Rotational temperature profiles of H2 in a microwave plasma chemical vapor deposition (MPCVD) reactor were measured via coherent anti-Stokes Raman scattering (CARS) spectroscopy. The temperature was found to increase with reactor pressure, plasma generator power, and distance from the deposition surface. At 10 Torr, the measured temperature range was approximately 700–1200 K while at 30 Torr it was 1200–2000 K under the conditions studied. The introduction of CH4 and N2 to the plasma increased the rotational temperature consistently. These findings will aid in understanding the function of the chemical composition and reactions in the plasma environment of these reactors which, to date, remains obscure.
Low-temperature growth of gallium nitride films by inductively coupled-plasma-enhanced reactive magnetron sputtering
Authors: Ni Chih-Jui , Chau-Nan Hong Franklin
Published: April 2014

Gallium nitride (GaN) films were grown on sapphire substrate by reactive magnetron sputtering. Inductively coupled-plasma (ICP) source was installed between the substrate holder and the sputtering target to increase the plasma density and the degree of ionization of nitrogen gas. Liquid Ga and Ar/N2 were used as the sputtering target and sputtering gases, respectively. X-ray diffraction measurements confirmed that the authors could grow high quality GaN crystallites at 500 °C. However, the crystalline GaN (0002) peak remained even by lowering the growth temperature down to 300 °C. The N:Ga ratio of the film grown at 500 °C was almost 1:1, and the nitrogen composition became higher toward the 1:1 N:Ga ratio with increasing the growth temperature. The high degree of ionization induced by ICP source was essential to the growth of high crystalline quality GaN films.
Mucus, It Is Not Just a Static Barrier
Authors: Chen Grace Y. , Stappenbeck Thaddeus S.
Published: April 2014

NLRP6 activates autophagy in intestinal goblet cells to promote mucus secretion and prevent microbial infection.
No Light Control
Authors: Riddihough Guy
Published: April 2014

In plants, light-dependent regulation of nuclear alternative splicing involves a signal generated within the chloroplast.
Optogenetic Inhibition
Authors: VanHook Annalisa M.
Published: April 2014

Engineered light-sensitive ion channels allow rapid and reversible neuronal inhibition.
Phasevarions Mediate Epigenetic Regulation of Antimicrobial Susceptibility in Neisseria meningitidis
Authors: Jen Freda E.-C. , Seib Kate L. , Jennings Michael P.
Published: April 2014

Phase variation is a common feature of host-adapted bacterial pathogens such as
Neisseria meningitidis
. Recently, we reported that this rapid on/off switching of gene expression occurs in DNA methyltransferases, altering expression in multiple genes via changes in global methylation. In the current study, we compared MIC values of strains with ModA11, ModA12, and ModD1 phasevarions, revealing MIC differences due to ModA11 and ModA12 switching, with a ModA11_OFF strain showing 4-fold reduced susceptibilities to ceftazidime and ciprofloxacin.
The Broad-Spectrum Antiviral Compound ST-669 Restricts Chlamydial Inclusion Development and Bacterial Growth and Localizes to Host Cell Lipid Droplets within Treated Cells
Authors: Sandoz Kelsi M. , Valiant William G. , Eriksen Steven G. , Hruby Dennis E. , Allen Robert D. , Rockey Daniel D.
Published: April 2014

Novel broad-spectrum antimicrobials are a critical component of a strategy for combating antibiotic-resistant pathogens. In this study, we explored the activity of the broad-spectrum antiviral compound ST-669 for activity against different intracellular bacteria and began a characterization of its mechanism of antimicrobial action. ST-669 inhibits the growth of three different species of chlamydia and the intracellular bacterium
Coxiella burnetii
in Vero and HeLa cells but not in McCoy (murine) cells. The antichlamydial and anti-
C. burnetii
activity spectrum was consistent with those observed for tested viruses, suggesting a common mechanism of action. Cycloheximide treatment in the presence of ST-669 abrogated the inhibitory effect, demonstrating that eukaryotic protein synthesis is required for tested activity. Immunofluorescence microscopy demonstrated that different chlamydiae grow atypically in the presence of ST-669, in a manner that suggests the compound affects inclusion formation and organization. Microscopic analysis of cells treated with a fluorescent derivative of ST-669 demonstrated that the compound localized to host cell lipid droplets but not to other organelles or the host cytosol. These results demonstrate that ST-669 affects intracellular growth in a host-cell-dependent manner and interrupts proper development of chlamydial inclusions, possibly through a lipid droplet-dependent process.
Benefits of a Pharmacology Antimalarial Reference Standard and Proficiency Testing Program Provided by the Worldwide Antimalarial Resistance Network (WWARN)
Authors: Lourens Chris , Lindegardh Niklas , Barnes Karen I. , Guerin Philippe J. , Sibley Carol H. , White Nicholas J. , Tarning Joel
Published: April 2014

Comprehensive assessment of antimalarial drug resistance should include measurements of antimalarial blood or plasma concentrations in clinical trials and in individual assessments of treatment failure so that true resistance can be differentiated from inadequate drug exposure. Pharmacometric modeling is necessary to assess pharmacokinetic-pharmacodynamic relationships in different populations to optimize dosing. To accomplish both effectively and to allow comparison of data from different laboratories, it is essential that drug concentration measurement is accurate. Proficiency testing (PT) of laboratory procedures is necessary for verification of assay results. Within the Worldwide Antimalarial Resistance Network (WWARN), the goal of the quality assurance/quality control (QA/QC) program is to facilitate and sustain high-quality antimalarial assays. The QA/QC program consists of an international PT program for pharmacology laboratories and a reference material (RM) program for the provision of antimalarial drug standards, metabolites, and internal standards for laboratory use. The RM program currently distributes accurately weighed quantities of antimalarial drug standards, metabolites, and internal standards to 44 pharmacology,
in vitro
, and drug quality testing laboratories. The pharmacology PT program has sent samples to eight laboratories in four rounds of testing. WWARN technical experts have provided advice for correcting identified problems to improve performance of subsequent analysis and ultimately improved the quality of data. Many participants have demonstrated substantial improvements over subsequent rounds of PT. The WWARN QA/QC program has improved the quality and value of antimalarial drug measurement in laboratories globally. It is a model that has potential to be applied to strengthening laboratories more widely and improving the therapeutics of other infectious diseases.
Ceftobiprole Activity against over 60,000 Clinical Bacterial Pathogens Isolated in Europe, Turkey, and Israel from 2005 to 2010
Authors: Farrell David J. , Flamm Robert K. , Sader Helio S. , Jones Ronald N.
Published: April 2014

Ceftobiprole medocaril is a newly approved drug in Europe for the treatment of hospital-acquired pneumonia (HAP) (excluding patients with ventilator-associated pneumonia but including ventilated HAP patients) and community-acquired pneumonia in adults. The aim of this study was to evaluate the
in vitro
antimicrobial activity of ceftobiprole against prevalent Gram-positive and -negative pathogens isolated in Europe, Turkey, and Israel during 2005 through 2010. A total of 60,084 consecutive, nonduplicate isolates from a wide variety of infections were collected from 33 medical centers. Species identification was confirmed, and all isolates were susceptibility tested using reference broth microdilution methods. Ceftobiprole had high activity against methicillin-susceptible
Staphylococcus aureus
(MSSA) (100.0% susceptible), methicillin-susceptible coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci, and
Streptococcus pneumoniae
(99.3% susceptible), with MIC
90
values of 0.25, 0.12, ≤0.06, and 0.5 μg/ml, respectively. Ceftobiprole was active against methicillin-resistant
S. aureus
(MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC
90
of 2 μg/ml. Ceftobiprole was active against
Enterococcus faecalis
(MIC
50/90
, 0.5/4 μg/ml) but not against most
Enterococcus faecium
isolates. Ceftobiprole was very potent against the majority of
Enterobacteriaceae
(87.3% susceptible), with >80% inhibited at ≤0.12 μg/ml. The potency of ceftobiprole against
Pseudomonas aeruginosa
(MIC
50/90
, 2/>8 μg/ml; 64.6% at MIC values of ≤4 μg/ml) was similar to that of ceftazidime (MIC
50/90
, 2/>16 μg/ml; 75.4% susceptible), but limited activity was observed against
Acinetobacter
spp. and
Stenotrophomonas maltophilia
. High activity was also observed against all
Haemophilus influenzae
(MIC
90
, ≤0.06 μg/ml) and
Moraxella catarrhalis
(MIC
50/90
, ≤0.06/0.25 μg/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this very large longitudinal sample of contemporary pathogens.
Validation of Antibiotic Susceptibility Testing Guidelines in a Routine Clinical Microbiology Laboratory Exemplifies General Key Challenges in Setting Clinical Breakpoints
Authors: Hombach Michael , Courvalin Patrice , Böttger Erik C.
Published: April 2014

This study critically evaluated the new European Committee for Antimicrobial Susceptibility Testing (EUCAST) antibiotic susceptibility testing guidelines on the basis of a large set of disk diffusion diameters determined for clinical isolates. We report several paradigmatic problems that illustrate key issues in the selection of clinical susceptibility breakpoints, which are of general importance not only for EUCAST but for all guidelines systems, i.e., (i) the need for species-specific determinations of clinical breakpoints/epidemiological cutoffs (ECOFFs), (ii) problems arising from pooling data from various sources, and (iii) the importance of the antibiotic disk content for separating non-wild-type and wild-type populations.
Pharmacological Study of Cefoxitin as an Alternative Antibiotic Therapy to Carbapenems in Treatment of Urinary Tract Infections Due to Extended-Spectrum-β-Lactamase-Producing Escherichia coli
Authors: Guet-Revillet H. , Emirian A. , Groh M. , Nebbad-Lechani B. , Weiss E. , Join-Lambert O. , Bille E. , Jullien V. , Zahar J. R.
Published: April 2014

Cefoxitin could be an alternative to carbapenems in extended-spectrum-beta-lactamase-producing
Escherichia coli
(ESBL-EC) infections. However, pharmacological and clinical data regarding cefoxitin are limited. Using a recent pharmacological model and the MICs of ESBL-EC collected from pyelonephritis, we determined the probabilities to reach four pharmacological targets: free cefoxitin concentrations above the MIC during 50% and 100% of the administration interval (T>MIC = 50% and T>MIC = 100%, respectively) and free cefoxitin concentrations above 4× MIC during 50% and 100% of the administration interval (T>4MIC = 50% and T>4MIC = 100%, respectively). Cefoxitin could be used to treat ESBL-EC pyelonephritis, but administration modalities should be optimized according to MICs in order to reach pharmacological targets.
Enhanced Antiretroviral Therapy in Rhesus Macaques Improves RT-SHIV Viral Decay Kinetics
Authors: North Thomas W. , Villalobos Andradi , Hurwitz Selwyn J. , Deere Jesse D. , Higgins Joanne , Chatterjee Payel , Tao Sijia , Kauffman Robert C. , Luciw Paul A. , Kohler James J. , Schinazi Raymond F.
Published: April 2014

Using an established nonhuman primate model, rhesus macaques were infected intravenously with a chimeric simian immunodeficiency virus (SIV) consisting of SIVmac239with the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase from clone HXBc2 (RT-SHIV). The impacts of two enhanced (four- and five-drug) highly active antiretroviral therapies (HAART) on early viral decay and rebound were determined. The four-drug combination consisted of an integrase inhibitor, L-870-812 (L-812), together with a three-drug regimen comprising emtricitabine [(−)-FTC], tenofovir (TFV), and efavirenz (EFV). The five-drug combination consisted of one analog for each of the four DNA precursors {using TFV, (−)-FTC, (−)-β-d-(2R,4R)-1,3-dioxolane-2,6-diaminopurine (amdoxovir [DAPD]), and zidovudine (AZT)}, together with EFV. A cohort treated with a three-drug combination of (−)-FTC, TFV, and EFV served as treated controls. Daily administration of a three-, four-, or five-drug combination of antiretroviral agents was initiated at week 6 or 8 after inoculation and continued up to week 50, followed by a rebound period. Plasma samples were collected routinely, and drug levels were monitored using liquid chromatography-tandem mass spectrometry (LC–MS-MS). Viral loads were monitored with a standard TaqMan quantitative reverse transcriptase PCR (qRT-PCR) assay. Comprehensive analyses of replication dynamics were performed. RT-SHIV infection in rhesus macaques produced typical viral infection kinetics, with untreated controls establishing persistent viral loads of >104copies of RNA/ml. RT-SHIV loads at the start of treatment (V0) were similar in all treated cohorts (P> 0.5). All antiretroviral drug levels were measureable in plasma. The four-drug and five-drug combination regimens (enhanced HAART) improved suppression of the viral load (within 1 week;P< 0.01) and had overall greater potency (P< 0.02) than the three-drug regimen (HAART). Moreover, rebound viremia occurred rapidly following cessation of any treatment. The enhanced HAART (four- or five-drug combination) showed significant improvement in viral suppression compared to the three-drug combination, but no combination was sufficient to eliminate viral reservoirs.
Characterization of a Respiratory Syncytial Virus L Protein Inhibitor
Authors: Tiong-Yip Choi-Lai , Aschenbrenner Lisa , Johnson Kenneth D. , McLaughlin Robert E. , Fan Jun , Challa SreeRupa , Xiong Hui , Yu Qin
Published: April 2014

The respiratory syncytial virus (RSV) L protein is a viral RNA-dependent RNA polymerase that contains multiple enzyme activities required for RSV replication. The RSV L inhibitors described in literature are limited by their cytotoxicity or the lack of RSV B subtype coverage. Here, we characterize a new RSV L inhibitor with strong antiviral activity against both RSV A and B subtypes and no detectable cytotoxicity. This compound, AZ-27, was equally active against RSV live viruses and subgenomic replicons and demonstrated advantages over other classes of RSV inhibitors in time-of-addition and cell line dependency studies. Resistance studies identified a dominant mutation in the putative capping enzyme domain of L protein, which conferred strong resistance to the AZ-27 series but not other classes of RSV inhibitors, supporting RSV L protein as the direct target for AZ-27. This novel and broad-spectrum RSV L polymerase inhibitor may pave the way toward an efficacious RSV therapeutic and provide a new tool for interrogation of the L protein function.
A Low-Affinity Penicillin-Binding Protein 2x Variant Is Required for Heteroresistance in Streptococcus pneumoniae
Authors: Engel Hansjürg , Mika Moana , Denapaite Dalia , Hakenbeck Regine , Mühlemann Kathrin , Heller Manfred , Hathaway Lucy J. , Hilty Markus
Published: April 2014

Heteroresistance to penicillin in
Streptococcus pneumoniae
is the ability of subpopulations to grow at a higher antibiotic concentration than expected from the MIC. This may render conventional resistance testing unreliable and lead to therapeutic failure. We investigated the role of the primary β-lactam resistance determinants, penicillin-binding protein 2b (PBP2b) and PBP2x, and the secondary resistance determinant PBP1a in heteroresistance to penicillin. Transformants containing PBP genes from the heteroresistant strain Spain
23F
2349
in the nonheteroresistant strain R6 background were tested for heteroresistance by population analysis profiling (PAP). We found that
pbp2x
, but not
pbp2b
or
pbp1a
alone, conferred heteroresistance to R6. However, a change of
pbp2x
expression was not observed, and therefore, expression does not correlate with an increased proportion of resistant subpopulations. In addition, the influence of the CiaRH system, mediating PBP-independent β-lactam resistance, was assessed by PAP on
ciaR
disruption mutants but revealed no heteroresistant phenotype. We also showed that the highly resistant subpopulations (HOM*) of transformants containing low-affinity
pbp2x
undergo an increase in resistance upon selection on penicillin plates that partially reverts after passaging on selection-free medium. Shotgun proteomic analysis showed an upregulation of phosphate ABC transporter subunit proteins encoded by
pstS
,
phoU
,
pstB
, and
pstC
in these highly resistant subpopulations. In conclusion, the presence of low-affinity
pbp2x
enables certain pneumococcal colonies to survive in the presence of β-lactams. Upregulation of phosphate ABC transporter genes may represent a reversible adaptation to antibiotic stress.
High Incidence and Endemic Spread of NDM-1-Positive Enterobacteriaceae in Henan Province, China
Authors: Qin Shangshang , Fu Ying , Zhang Qijing , Qi Hui , Wen Jian Guo , Xu Hui , Xu Lijuan , Zeng Li , Tian Hao , Rong Lijuan , Li Yonghong , Shan Lihong , Xu Hongde , Yu Yunsong , Feng Xianju , Liu Hong-Min
Published: April 2014

The emergence and spread of New Delhi metallo-β-lactamase 1 (NDM-1)-producing carbapenem-resistant
Enterobacteriaceae
(CRE) present an urgent threat to human health. In China, the
bla
NDM-1
gene has been reported mostly in
Acinetobacter
spp. but is rarely found in
Enterobacteriaceae
. Here, we report a high incidence and endemic spread of NDM-1-producing CRE in Henan Province in China. Sixteen (33.3%) of the 48 CRE isolates obtained from patients during June 2011 to July 2012 were positive for
bla
NDM-1
, and the gene was found to be carried on plasmids of various sizes (∼55 to ∼360 kb). These plasmids were readily transferrable to recipient
Escherichia coli
by conjugation, conferred resistance to multiple antibiotics, and belonged to multiple replicon types. The
bla
NDM-1
-positive CRE isolates were genetically diverse, and six new multilocus sequence typing (MLST) sequence types were linked to the carriage of NDM-1. Five of the isolates were classified as extensively drug-resistant (XDR) isolates, four of which also carried the
fosA3
gene conferring resistance to fosfomycin, an alternative drug for treating infections by CRE. In each
bla
NDM-1
-positive CRE isolate, the
bla
NDM-1
gene was downstream of an intact IS
Aba125
element and upstream of the
ble
MBL
gene. Furthermore, gene environment analysis suggested the possible transmission of
bla
NDM-1
-containing sequences from
Acinetobacter
spp. to
Klebsiella pneumoniae
and
Klebsiella oxytoca
. These findings reveal the emergence and active transmission of NDM-1-positive CRE in China and underscore the need for heightened measures to control their further spread.
SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion
Authors: Gallotta Marilena , Gancitano Giovanni , Pietrocola Giampiero , Mora Marirosa , Pezzicoli Alfredo , Tuscano Giovanna , Chiarot Emiliano , Nardi-Dei Vincenzo , Taddei Anna Rita , Rindi Simonetta , Speziale Pietro , Soriani Marco , Grandi Guido , Margarit Immaculada , Bensi Giuliano
Published: April 2014

Group A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of the
spy0269
gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interact
in vitro
with the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cells
in vitro
and that
Lactococcus lactis
expressing Spy0269 on its cell surface could adhere to mammalian cells
in vitro
and to mice nasal mucosa
in vivo
. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (

S
treptococcus
py
ogenes

A
dhesion and
D
ivision protein).
FTT0831c/FTL_0325 Contributes to Francisella tularensis Cell Division, Maintenance of Cell Shape, and Structural Integrity
Authors: Robertson Gregory T. , Case Elizabeth Di Russo , Dobbs Nicole , Ingle Christine , Balaban Murat , Celli Jean , Norgard Michael V.
Published: April 2014

The
Francisella
FTT0831c/FTL_0325 gene encodes amino acid motifs to suggest it is a lipoprotein and that it may interact with the bacterial cell wall as a member of the OmpA-like protein family. Previous studies have suggested that FTT0831c is surface exposed and required for virulence of
Francisella tularensis
by subverting the host innate immune response (M. Mahawar et al., J. Biol. Chem. 287:25216–25229, 2012). We also found that FTT0831c is required for murine pathogenesis and intramacrophage growth of Schu S4, but we propose a different model to account for the proinflammatory nature of the resultant mutants. First, inactivation of FTL_0325 from live vaccine strain (LVS) or FTT0831c from Schu S4 resulted in temperature-dependent defects in cell viability and morphology. Loss of FTT0831c was also associated with an unusual defect in lipopolysaccharide O-antigen synthesis, but loss of FTL_0325 was not. Full restoration of these properties was observed in complemented strains expressing FTT0831c
in trans
, but not in strains lacking the OmpA motif, suggesting that cell wall contact is required. Finally, growth of the LVS FTL_0325 mutant in Mueller-Hinton broth at 37°C resulted in the appearance of membrane blebs at the poles and midpoint, prior to the formation of enlarged round cells that showed evidence of compromised cellular membranes. Taken together, these data are more consistent with the known structural role of OmpA-like proteins in linking the OM to the cell wall and, as such, maintenance of structural integrity preventing altered surface exposure or release of Toll-like receptor 2 agonists during rapid growth of
Francisella
in vitro
and
in vivo
.
The Salmonella Effector SteA Contributes to the Control of Membrane Dynamics of Salmonella-Containing Vacuoles
Authors: Domingues Lia , Holden David W. , Mota Luís Jaime
Published: April 2014

Salmonella enterica
serovar Typhimurium is a bacterial pathogen causing gastroenteritis in humans and a typhoid-like systemic disease in mice.
S
. Typhimurium virulence is related to its capacity to multiply intracellularly within a membrane-bound compartment, the
Salmonella
-containing vacuole (SCV), and depends on type III secretion systems that deliver bacterial effector proteins into host cells. Here, we analyzed the cellular function of the
Salmonella
effector SteA. We show that, compared to cells infected by wild-type
S
. Typhimurium, cells infected by Δ
steA
mutant bacteria displayed fewer
Salmonella
-induced filaments (SIFs), an increased clustering of SCVs, and morphologically abnormal vacuoles containing more than one bacterium. The increased clustering of SCVs and the appearance of vacuoles containing more than one bacterium were suppressed by inhibition of the activity of the microtubule motor dynein or kinesin-1. Clustering and positioning of SCVs are controlled by the effectors SseF and SseG, possibly by helping to maintain a balanced activity of microtubule motors on the bacterial vacuoles. Deletion of
steA
in
S
. Typhimurium Δ
sseF
or Δ
sseG
mutants revealed that SteA contributes to the characteristic scattered distribution of Δ
sseF
or Δ
sseG
mutant SCVs in infected cells. Overall, this shows that SteA participates in the control of SCV membrane dynamics. Moreover, it indicates that SteA is functionally linked to SseF and SseG and suggests that it might contribute directly or indirectly to the regulation of microtubule motors on the bacterial vacuoles.
Chemokines and Antimicrobial Peptides Have a
cag
-Dependent Early Response to Helicobacter pylori Infection in Primary Human Gastric Epithelial Cells
Authors: Mustapha Pascale , Paris Isabelle , Garcia Magali , Tran Cong Tri , Cremniter Julie , Garnier Martine , Faure Jean-Pierre , Barthes Thierry , Boneca Ivo G. , Morel Franck , Lecron Jean-Claude , Burucoa Christophe , Bodet Charles
Published: April 2014

Helicobacter pylori
infection systematically causes chronic gastric inflammation that can persist asymptomatically or evolve toward more severe gastroduodenal pathologies, such as ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. The
cag
pathogenicity island (
cag
PAI) of
H. pylori
allows translocation of the virulence protein CagA and fragments of peptidoglycan into host cells, thereby inducing production of chemokines, cytokines, and antimicrobial peptides. In order to characterize the inflammatory response to
H. pylori
, a new experimental protocol for isolating and culturing primary human gastric epithelial cells was established using pieces of stomach from patients who had undergone sleeve gastrectomy. Isolated cells expressed markers indicating that they were mucin-secreting epithelial cells. Challenge of primary epithelial cells with
H. pylori
B128 underscored early dose-dependent induction of expression of mRNAs of the inflammatory mediators CXCL1 to -3, CXCL5, CXCL8, CCL20, BD2, and tumor necrosis factor alpha (TNF-α). In AGS cells, significant expression of only CXCL5 and CXCL8 was observed following infection, suggesting that these cells were less reactive than primary epithelial cells. Infection of both cellular models with
H. pylori
B128ΔcagM, a
cag
PAI mutant, resulted in weak inflammatory-mediator mRNA induction. At 24 h after infection of primary epithelial cells with
H. pylori
, inflammatory-mediator production was largely due to
cag
PAI substrate-independent virulence factors. Thus,
H. pylori
cag
PAI substrate appears to be involved in eliciting an epithelial response during the early phases of infection. Afterwards, other virulence factors of the bacterium take over in development of the inflammatory response. Using a relevant cellular model, this study provides new information on the modulation of inflammation during
H. pylori
infection.
Staphylococcal Enterotoxin B-Induced MicroRNA-155 Targets SOCS1 To Promote Acute Inflammatory Lung Injury
Authors: Rao Roshni , Nagarkatti Prakash , Nagarkatti Mitzi
Published: April 2014

Staphylococcal enterotoxin B (SEB) causes food poisoning in humans. It is considered a biological weapon, and inhalation can trigger lung injury and sometimes respiratory failure. Being a superantigen, SEB initiates an exaggerated inflammatory response. While the role of microRNAs (miRNAs) in immune cell activation is getting increasing recognition, their role in the regulation of inflammatory disease induced by SEB has not been studied. In this investigation, we demonstrate that exposure to SEB by inhalation results in acute inflammatory lung injury accompanied by an altered miRNA expression profile in lung-infiltrating cells. Among the miRNAs that were significantly elevated, miR-155 was the most overexpressed. Interestingly, miR-155−/−mice were protected from SEB-mediated inflammation and lung injury. Further studies revealed a functional link between SEB-induced miR-155 and proinflammatory cytokine gamma interferon (IFN-γ). Through the use of bioinformatics tools, suppressor of cytokine signaling 1 (SOCS1), a negative regulator of IFN-γ, was identified as a potential target of miR-155. While miR-155−/−mice displayed increased expression ofSocs1, the overexpression of miR-155 led to its suppression, thereby enhancing IFN-γ levels. Additionally, the inhibition of miR-155 resulted in restoredSocs1expression. Together, our data demonstrate an important role for miR-155 in promoting SEB-mediated inflammation in the lungs throughSocs1suppression and suggest that miR-155 may be an important target in preventing SEB-mediated inflammation and tissue injury.
Structural Conservation, Variability, and Immunogenicity of the T6 Backbone Pilin of Serotype M6 Streptococcus pyogenes
Authors: Young Paul G. , Moreland Nicole J. , Loh Jacelyn M. , Bell Anita , Atatoa Carr Polly , Proft Thomas , Baker Edward N.
Published: April 2014

Group A streptococcus (GAS;
Streptococcus pyogenes
) is a Gram-positive human pathogen that causes a broad range of diseases ranging from acute pharyngitis to the poststreptococcal sequelae of acute rheumatic fever. GAS pili are highly diverse, long protein polymers that extend from the cell surface. They have multiple roles in infection and are promising candidates for vaccine development. This study describes the structure of the T6 backbone pilin (BP; Lancefield T-antigen) from the important M6 serotype. The structure reveals a modular arrangement of three tandem immunoglobulin-like domains, two with internal isopeptide bonds. The T6 pilin lysine, essential for polymerization, is located in a novel VAKS motif that is structurally homologous to the canonical YPKN pilin lysine in other three- and four-domain Gram-positive pilins. The T6 structure also highlights a conserved pilin core whose surface is decorated with highly variable loops and extensions. Comparison to other Gram-positive BPs shows that many of the largest variable extensions are found in conserved locations. Studies with sera from patients diagnosed with GAS-associated acute rheumatic fever showed that each of the three T6 domains, and the largest of the variable extensions (V8), are targeted by IgG during infection
in vivo
. Although the GAS BP show large variations in size and sequence, the modular nature of the pilus proteins revealed by the T6 structure may aid the future design of a pilus-based vaccine.
Not just another case of low back pain
Authors: Etzkorn Kristin , Oliver Alyce M
Published: April 2014

A 55-year-old woman presented with persistent, progressive low back and neck pain for 5 years that had failed conservative therapy with analgesics and epidural injections. Physical examination revealed range of motion of lumbar and cervical spine were significantly limited in all directions and she had a bluish discolouration of the pinnae bilaterally. She had elevated urinary excretion of homogentisic acid, diagnostic of alkaptonuria. Further investigation with imaging of the spine revealed diffuse advanced degenerative disease of the cervical and lumbar spine consistent with ochronotic arthropathy.
The future of population registers: linking routine health datasets to assess a population's current glycaemic status for quality improvement
Authors: Chan Wing Cheuk , Jackson Gary , Wright Craig Shawe , Orr-Walker Brandon , Drury Paul L , Boswell D Ross , Lee Mildred Ai Wei , Papa Dean , Jackson Rod
Published: April 2014

Objectives

To determine the diabetes screening levels and known glycaemic status of all individuals by age, gender and ethnicity within a defined geographic location in a timely and consistent way to potentially facilitate systematic disease prevention and management.

Design

Retrospective observational study.

Setting

Auckland region of New Zealand.

Participants

1 475 347 people who had utilised publicly funded health service in New Zealand and domicile in the Auckland region of New Zealand in 2010. The health service utilisation population was individually linked to a comprehensive regional laboratory repository dating back to 2004.

Outcome measures

The two outcomes measures were glycaemia-related blood testing coverage (glycated haemoglobin (HbA1c), fasting and random glucose and glucose tolerance tests), and the proportions and number of people with known dysglycaemia in 2010 using modified American Diabetes Association (ADA) and WHO criteria.

Results

Within the health service utilisation population, 792 560 people had had at least one glucose or HbA1c blood test in the previous 5.5 years. Overall, 81% of males (n=198 086) and 87% of females (n=128 982) in the recommended age groups for diabetes screening had a blood test to assess their glycaemic status. The estimated age-standardised prevalence of dysglycaemia was highest in people of Pacific Island ethnicity at 11.4% (95% CI 11.2% to 11.5%) for males and 11.6% (11.4% to 11.8%) for females, followed closely by people of Indian ethnicity at 10.8% (10.6% to 11.1%) and 9.3% (9.1% to 9.6%), respectively. Among the indigenous Maori population, the prevalence was 8.2% (7.9% to 8.4%) and 7% (6.8% to 7.2%), while for ‘Others’ (mainly Europeans) it was 3% (3% to 3.1%) and 2.2% (2.1% to 2.2%), respectively.

Conclusions

We have demonstrated that the data linkage between a laboratory repository and national administrative datasets has the potential to provide a systematic and consistent individual level clinical information that is relevant to medical auditing for a large geographically defined population.
Acupuncture for the treatment of chronic obstructive pulmonary disease: a protocol of a systematic review
Authors: Choi Tae-Young , Jun Ji Hee , Choi Jun-Young , Kim Jong-In , Lee Myeong Soo , Ernst Edzard
Published: April 2014

Introduction

This review aims to evaluate the efficacy of acupuncture in the treatment of chronic obstructive pulmonary disease (COPD).

Methods and analysis

14 databases will be searched from their inception. These include PubMed, AMED, EMBASE, the Cochrane Library, seven Korean medical databases (Korean Studies Information Service System, DBPIA, Oriental Medicine Advanced Searching Integrated System, Research Information Service System, KoreaMed, The Town Society of Science Technology and the Korean National Assembly Library), three Chinese Databases (China National Knowledge Infrastructure Database (CNKI), the Chongqing VIP Chinese Science and Technology Periodical Database (VIP), and the Wanfang Database). Only randomised clinical trials (RCTs) using acupuncture for COPD will be considered. The selection of the studies, data abstraction and validation will be performed independently by two researchers. Methodological quality will be assessed with the Cochrane risk of bias.

Dissemination

The systematic review will be published in a peer-reviewed journal. The review will also be disseminated electronically and in print. Updates of the review will be conducted to inform and guide the healthcare practice and policy.

Trial registration number

PROSPERO 2013: CRD42013004824.
Falling mortality when adjusted for comorbidity in upper gastrointestinal bleeding: relevance of multi-disciplinary care
Authors: Taha Ali S , Saffouri Eliana , McCloskey Caroline , Craigen Theresa , Angerson Wilson J
Published: April 2014

Objectives

The understanding of changes in comorbidity might improve the management of upper gastrointestinal bleeding (UGIB); such changes might not be detectable in short-term studies. We aimed to study UGIB mortality as adjusted for comorbidity and the trends in risk scores over a 14-year period.

Methods

Patients presenting with UGIB to a single institution, 1996–2010, were assessed. Those with multiple comorbidities were managed in a multi-disciplinary care unit since 2000. Trends with time were assessed using logistic regression, including those for Charlson comorbidity score, the complete Rockall score and 30-day mortality.

Results

2669 patients were included. The Charlson comorbidity score increased significantly with time: the odds of a high (3+) score increasing at a relative rate of 4.4% a year (OR 1.044; p<0.001). The overall 30-day mortality was 4.9% and inpatient mortality was 7.1%; these showed no relationship with time. When adjusted for the increasing comorbidity, the odds of death decreased significantly at a relative rate of 4.5% per year (p=0.038). After the introduction of multi-disciplinary care, the raw mortality OR was 0.680 (p=0.08), and adjusted for comorbidity it was 0.566 (p=0.013).

Conclusions

30-day mortality decreased when adjusted for the rising comorbidity in UGIB; whether this is related to the introduction of multi-disciplinary care needs to be considered.
Too heavy, too late: investigating perinatal health outcomes in immigrants residing in Spain. A cross-sectional study (2009–2011)
Authors: Juárez Sol P , Revuelta-Eugercios Bárbara A
Published: April 2014

Background

Studies have shown that immigrants residing in Spain have lower risks of delivering low birthweight (LBW) and preterm babies despite their socioeconomic disadvantages (the healthy migrant paradox). However, less is known about other important perinatal outcomes derived from birth weight and gestational age such as macrosomia and post-term birth. This paper aims to compare the main indicators related to birth weight and gestational age (LBW, macrosomia, preterm and post-term) for immigrants and Spaniards.

Methods

Cross-sectional study based on the Spanish vital statistics for years 2009–2011. Multinomial regression models were performed to obtain crude and adjusted ORs and their 95% CIs.

Results

After adjusting for known confounders, compared with Spaniards, most immigrant groups show lower or not significantly different risks of delivering LBW (OR between 0.65 and 0.87) or, more exceptionally, preterm babies (between 0.75 and 0.93). However, most of them also show higher risks of delivering macrosomic (OR between 1.21 and 2.58) and post-term babies (OR between 1.11 and 1.50). Mothers from sub-Saharan Africa show a higher risk in all perinatal outcomes studied.

Conclusions

The immigrant health paradox should be carefully assessed in comprehensive terms. Together with a predominantly lower risk of LBW, most immigrants have a higher risk of macrosomia, post-term and preterm births. These results have policy-making implications since studying the right tail of the birth weight and gestational age distributions implies considering a different set of risk factors.
Onyx embolization of dural arteriovenous fistulas of the cavernous sinus through the superior pharyngeal branch of the ascending pharyngeal artery
Authors: Pero Guglielmo , Quilici Luca , Piano Mariangela , Valvassori Luca , Boccardi Edoardo
Published: April 2014

We report three cases of dural arteriovenous fistula (DAVF) of the cavernous sinus treated by Onyx injection through the superior pharyngeal branch of the ascending pharyngeal artery. The treatment of choice of DAVFs of the cavernous sinus is endovascular, and it is preferentially done via transvenous occlusion of the cavernous sinus. The cavernous sinus can be reached through either the inferior petrosal sinus or the superior ophthalmic vein. When these venous routes are occluded, the first attempt is to pass through the occluded inferior petrosal sinus, but sometimes this attempt can fail. In some cases there are small transosseous feeders to the fistula arising from the superior pharyngeal branch of the ascending pharyngeal artery. When all of the more conventional approaches are unattainable, this route can be attempted. In our experience, it allowed safe and rapid occlusion of the fistula.