bluuebunny/crossref_metadata_2025 huggingface dataset:
Discerning the Role of Bacteroides fragilis in Celiac Disease Pathogenesis
Authors: Sánchez E. , Laparra J. M. , Sanz Y.
Published: July 2012

Celiac disease (CD) is associated with intestinal dysbiosis, which can theoretically lead to dysfunctions in host-microbe interactions and contribute to the disease. In the present study, possible differences inBacteroidesspp. and their pathogenic features between CD patients and controls were investigated.Bacteroidesclones (n= 274) were isolated, identified, and screened for the presence of the virulence genes (bftandmpII) coding for metalloproteases. The proteolytic activity of selectedBacteroides fragilisstrains was evaluated by zymography and, after gastrointestinal digestion of gliadin, by high-pressure liquid chromatography/electrospray ionization/tandem mass spectrometry. The effects ofB. fragilisstrains on Caco-2 cell culture permeability and inflammatory response to digested gliadin were determined.B. fragiliswas more frequently identified in CD patients than in healthy controls, in contrast toBacteroides ovatus.B. fragilisclones carrying virulence genes coding for metalloproteases were more abundant in CD patients than in controls.B. fragilisstrains, representing the isolated clones and carrying metalloprotease genes, showed gelatinase activity and exerted the strongest adverse effects on the integrity of the Caco-2 cell monolayer. AllB. fragilisstrains also showed gliadin-hydrolyzing activity, and some of them generated immunogenic peptides that preserved or increased inflammatory cytokine production (tumor necrosis factor alpha) and showed increased ability to permeate through Caco-2 cell cultures. These findings suggest that increased abundance ofB. fragilisstrains with metalloprotease activities could play a role in CD pathogenesis, although furtherin vivostudies are required to support this hypothesis.
Evaluation of Near-Infrared Pasteurization in Controlling Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium, and Listeria monocytogenes in Ready-To-Eat Sliced Ham
Authors: Ha Jae-Won , Ryu Sang-Ryeol , Kang Dong-Hyun
Published: July 2012

This study was conducted to investigate the efficacy of near-infrared (NIR) heating to reduce
Salmonella enterica
serovar Typhimurium,
Escherichia coli
O157:H7, and
Listeria monocytogenes
in ready-to-eat (RTE) sliced ham compared to conventional convective heating, and the effect of NIR heating on quality was determined by measuring the color and texture change. A cocktail of three pathogens was inoculated on the exposed or protected surfaces of ham slices, followed by NIR or conventional heating at 1.8 kW. NIR heating for 50 s achieved 4.1-, 4.19-, and 3.38-log reductions in surface-inoculated
S.
Typhimurium,
E. coli
O157:H7, and
L. monocytogenes
, respectively, whereas convective heating needed 180 s to attain comparable reductions for each pathogen. There were no statistically significant (
P
> 0.05) differences in reduction between surface- and internally inoculated pathogens at the end of NIR treatment (50 s). However, when treated with conventional convective heating, significant (
P
< 0.05) differences were observed at the final stages of the treatment (150 and 180 s). Color values and texture parameters of NIR-treated (50-s treatment) ham slices were not significantly (
P
> 0.05) different from those of nontreated samples. These results suggest that NIR heating can be applied to control internalized pathogens as well as surface-adhering pathogens in RTE sliced meats without affecting product quality.
Phosphate Starvation Promotes Swarming Motility and Cytotoxicity of Pseudomonas aeruginosa
Authors: Bains Manjeet , Fernández Lucía , Hancock Robert E. W.
Published: July 2012

We investigated the transcriptional responses ofPseudomonas aeruginosaunder phosphate-deficient (0.2 mM) conditions compared to phosphate sufficiency (1 mM). This elicited enormous transcriptional changes in genes related to phosphate acquisition, quorum sensing, chemotaxis, toxin secretion, and regulation. This dysregulation also led to increased virulence-associated phenotypes, including swarming motility and cytotoxicity.
Comparative Inactivation of Murine Norovirus, Human Adenovirus, and Human JC Polyomavirus by Chlorine in Seawater
Authors: de Abreu Corrêa Adriana , Carratala Anna , Barardi Celia Regina Monte , Calvo Miquel , Girones Rosina , Bofill-Mas Sílvia
Published: July 2012

Viruses excreted by humans affect the commercial and recreational use of coastal water. Shellfish produced in contaminated waters have been linked to many episodes and outbreaks of viral gastroenteritis, as well as other food-borne diseases worldwide. The risk can be reduced by appropriate treatment following harvesting and by depuration. The kinetics of inactivation of murine norovirus 1 and human adenovirus 2 in natural and artificial seawater by free available chlorine was studied by quantifying genomic copies (GC) using quantitative PCR and infectious viral particles (PFU). Human JC polyomavirus Mad4 kinetics were evaluated by quantitative PCR. DNase or RNase were used to eliminate free genomes and assess potential viral infectivity when molecular detection was performed. At 30 min of assay, human adenovirus 2 showed 2.6- and 2.7-log10GC reductions and a 2.3- and 2.4-log10PFU reductions in natural and artificial seawater, respectively, and infectious viral particles were still observed at the end of the assay. When DNase was used prior to the nucleic acid extraction the kinetic of inactivation obtained by quantitative PCR was statistically equivalent to the one observed by infectivity assays. For murine norovirus 1, 2.5, and 3.5-log10GC reductions were observed in natural and artificial seawater, respectively, while no viruses remained infectious after 30 min of contact with chlorine. Regarding JC polyomavirus Mad4, 1.5- and 1.1-log10GC reductions were observed after 30 min of contact time. No infectivity assays were conducted for this virus. The results obtained provide data that might be applicable to seawater used in shellfish depuration.
Characterization of a Novel Microcin That Kills Enterohemorrhagic Escherichia coli O157:H7 and O26
Authors: Eberhart Lauren J. , Deringer James R. , Brayton Kelly A. , Sawant Ashish A. , Besser Thomas E. , Call Douglas R.
Published: July 2012

A novel phenotype was recently identified in which specific strains of
Escherichia coli
inhibit competing
E. coli
strains via a mechanism that was designated “proximity-dependent inhibition” (PDI). PDI-expressing (PDI
+
)
E. coli
is known to inhibit susceptible (PDI
−
)
E. coli
strains, including several enterohemorrhagic (EHEC) and enterotoxigenic (ETEC)
E. coli
strains. In this study, every strain from a genetically diverse panel of
E. coli
O157:H7 (
n
= 25) and additional strains of
E. coli
serovar O26 were susceptible to the PDI phenotype. LIVE/DEAD staining was consistent with inhibition by killing of susceptible cells. Comparative genome analysis identified the genetic component of PDI, which is composed of a plasmid-borne (Incl1) operon encoding a putative microcin and associated genes for transport, immunity, and microcin activation. Transfer of the plasmid to a PDI
−
strain resulted in transfer of the phenotype, and deletion of the genes within the operon resulted in loss of the inhibition phenotype. Deletion of chromosomally encoded
tolC
also resulted in loss of the inhibitory phenotype, and this confirmed that the putative microcin is most likely secreted via a type I secretion pathway. Deletion of an unrelated plasmid gene did not affect the PDI phenotype. Quantitative reverse transcription (RT)-PCR demonstrated that microcin expression is correlated with logarithmic-phase growth. The ability to inhibit a diversity of
E. coli
strains indicates that this microcin may influence gut community composition and could be useful for control of important enteric pathogens.
Culture- and Quantitative IS
900
Real-Time PCR-Based Analysis of the Persistence of Mycobacterium avium subsp. paratuberculosis in a Controlled Dairy Cow Farm Environment
Authors: Moravkova M. , Babak V. , Kralova A. , Pavlik I. , Slana I.
Published: July 2012

The aim of this study was to monitor the persistence of
Mycobacterium avium
subsp.
paratuberculosis
in environmental samples taken from a Holstein farm with a long history of clinical paratuberculosis. A herd of 606 head was eradicated, and mechanical cleaning and disinfection with chloramine B with ammonium (4%) was carried out on the farm; in the surrounding areas (on the field and field midden) lime was applied. Environmental samples were collected before and over a period of 24 months after destocking. Only one sample out of 48 (2%) examined on the farm (originating from a waste pit and collected before destocking) was positive for
M. avium
subsp.
paratuberculosis
by cultivation on solid medium (Herrold's egg yolk medium). The results using real-time quantitative PCR (qPCR) showed that a total of 81% of environmental samples with an average mean
M. avium
subsp.
paratuberculosis
cell number of 3.09 × 10
3
were positive for
M. avium
subsp.
paratuberculosis
before destocking compared to 43% with an average mean
M. avium
subsp.
paratuberculosis
cell number of 5.86 × 10
2
after 24 months.
M. avium
subsp.
paratuberculosis
-positive samples were detected in the cattle barn as well as in the calf barn and surrounding areas.
M. avium
subsp.
paratuberculosis
was detected from different matrices: floor and instrument scrapings, sediment, or scraping from watering troughs, waste pits, and cobwebs.
M. avium
subsp.
paratuberculosis
DNA was also detected in soil and plants collected on the field midden and the field 24 months after destocking. Although the proportion of positive samples decreased from 64% to 23% over time, the numbers of
M. avium
subsp.
paratuberculosis
cells were comparable.
Draft Genome Sequence of a Psychrotolerant Sulfur-Oxidizing Bacterium, Sulfuricella denitrificans skB26, and Proteomic Insights into Cold Adaptation
Authors: Watanabe Tomohiro , Kojima Hisaya , Fukui Manabu
Published: July 2012

Except for several conspicuous cases, very little is known about sulfur oxidizers living in natural freshwater environments.Sulfuricella denitrificansskB26 is a psychrotolerant sulfur oxidizer recently isolated from a freshwater lake as a representative of a new genus in the classBetaproteobacteria. In this study, an approximately 3.2-Mb draft genome sequence of strain skB26 was obtained. In the draft genome, consisting of 23 contigs, a single rRNA operon, 43 tRNA genes, and 3,133 coding sequences were identified. The identified genes include those required for sulfur oxidation, denitrification, and carbon fixation. Comparative proteomic analysis was conducted to assess cold adaptation mechanisms of this organism. From cells grown at 22°C and 5°C, proteins were extracted for analysis by nano-liquid chromatography–electrospray ionization–tandem mass spectrometry. In the cells cultured at 5°C, relative abundances of ribosomal proteins, cold shock proteins, and DEAD/DEAH box RNA helicases were increased in comparison to those at 22°C. These results suggest that maintenance of proper translation is critical for growth under low-temperature conditions, similar to the case for other cold-adapted prokaryotes.
Predicted Protein Subcellular Localization in Dominant Surface Ocean Bacterioplankton
Authors: Luo Haiwei
Published: July 2012

Bacteria consume dissolved organic matter (DOM) through hydrolysis, transport and intracellular metabolism, and these activities occur in distinct subcellular localizations. Bacterial protein subcellular localizations for several major marine bacterial groups were predicted using genomic, metagenomic and metatranscriptomic data sets following modification of MetaP software for use with partial gene sequences. The most distinct pattern of subcellular localization was found for
Bacteroidetes
, whose genomes were substantially enriched with outer membrane and extracellular proteins but depleted of inner membrane proteins compared with five other taxa (SAR11, Roseobacter,
Synechococcus
,
Prochlorococcus
, oligotrophic marine
Gammaproteobacteria
). When subcellular localization patterns were compared between genes and transcripts, three taxa had expression biased toward proteins localized to cell locations outside of the cytosol (SAR11, Roseobacter, and
Synechococcus
), as expected based on the importance of carbon and nutrient acquisition in an oligotrophic ocean, but two taxa did not (oligotrophic marine
Gammaproteobacteria
and
Bacteroidetes
). Diel variations in the fraction and putative gene functions of transcripts encoding inner membrane and periplasmic proteins compared to cytoplasmic proteins suggest a close coupling of photosynthetic extracellular release and bacterial consumption, providing insights into interactions between phytoplankton, bacteria, and DOM.
Unexpected Specificity of Interspecies Cobamide Transfer from Geobacter spp. to Organohalide-Respiring Dehalococcoides mccartyi Strains
Authors: Yan Jun , Ritalahti Kirsti M. , Wagner Darlene D. , Löffler Frank E.
Published: July 2012

Dehalococcoides mccartyi
strains conserve energy from reductive dechlorination reactions catalyzed by corrinoid-dependent reductive dehalogenase enzyme systems.
Dehalococcoides
lacks the ability for
de novo
corrinoid synthesis, and pure cultures require the addition of cyanocobalamin (vitamin B
12
) for growth. In contrast,
Geobacter lovleyi
, which dechlorinates tetrachloroethene to
cis
-1,2-dichloroethene (
cis
-DCE), and the nondechlorinating species
Geobacter sulfurreducens
have complete sets of cobamide biosynthesis genes and produced 12.9 ± 2.4 and 24.2 ± 5.8 ng of extracellular cobamide per liter of culture suspension, respectively, during growth with acetate and fumarate in a completely synthetic medium.
G. lovleyi
-
D. mccartyi
strain BAV1 or strain FL2 cocultures provided evidence for interspecies corrinoid transfer, and
cis
-DCE was dechlorinated to vinyl chloride and ethene concomitant with
Dehalococcoides
growth. In contrast, negligible increase in
Dehalococcoides
16S rRNA gene copies and insignificant dechlorination occurred in
G. sulfurreducens
-
D. mccartyi
strain BAV1 or strain FL2 cocultures. Apparently,
G. lovleyi
produces a cobamide that complements
Dehalococcoides
' nutritional requirements, whereas
G. sulfurreducens
does not. Interestingly,
Dehalococcoides
dechlorination activity and growth could be restored in
G. sulfurreducens
-
Dehalococcoides
cocultures by adding 10 μM 5′,6′-dimethylbenzimidazole. Observations made with the
G. sulfurreducens
-
Dehalococcoides
cocultures suggest that the exchange of the lower ligand generated a cobalamin, which supported
Dehalococcoides
activity. These findings have implications for
in situ
bioremediation and suggest that the corrinoid metabolism of
Dehalococcoides
must be understood to faithfully predict, and possibly enhance, reductive dechlorination activities.
Temporal Dynamics and Decay of Putatively Allochthonous and Autochthonous Viral Genotypes in Contrasting Freshwater Lakes
Authors: Hewson Ian , Barbosa Jorge G. , Brown Julia M. , Donelan Ryan P. , Eaglesham James B. , Eggleston Erin M. , LaBarre Brenna A.
Published: July 2012

Aquatic viruses play important roles in the biogeochemistry and ecology of lacustrine ecosystems; however, their composition, dynamics, and interactions with viruses of terrestrial origin are less extensively studied. We used a viral shotgun metagenomic approach to elucidate candidate autochthonous (i.e., produced within the lake) and allochthonous (i.e., washed in from other habitats) viral genotypes for a comparative study of their dynamics in lake waters. Based on shotgun metagenomes prepared from catchment soil and freshwater samples from two contrasting lakes (Cayuga Lake and Fayetteville Green Lake), we selected two putatively autochthonous viral genotypes (phycodnaviruses likely infecting algae and cyanomyoviruses likely infecting picocyanobacteria) and two putatively allochthonous viral genotypes (geminiviruses likely infecting terrestrial plants and circoviruses infecting unknown hosts but common in soil libraries) for analysis by genotype-specific quantitative PCR (TaqMan) applied to DNAs from viruses in the viral size fraction of lake plankton, i.e., 0.2 μm > virus > 0.02 μm. The abundance of autochthonous genotypes largely reflected expected host abundance, while the abundance of allochthonous genotypes corresponded with rainfall and storm events in the respective catchments, suggesting that viruses with these genotypes may have been transported to the lake in runoff. The decay rates of allochthonous and autochthonous genotypes, assessed in incubations where all potential hosts were killed, were generally lower (0.13 to 1.50% h
−1
) than those reported for marine virioplankton but similar to those for freshwater virioplankton. Both allochthonous and autochthonous viral genotypes were detected at higher concentrations in subsurface sediments than at the water-sediment interface. Our data indicate that putatively allochthonous viruses are present in lake plankton and sediments, where their temporal dynamics reflect active transport to the lake during hydrological events and then decay once there.
NasT-Mediated Antitermination Plays an Essential Role in the Regulation of the Assimilatory Nitrate Reductase Operon in Azotobacter vinelandii
Authors: Wang Baomin , Pierson Leland S. , Rensing Christopher , Gunatilaka Malkanthi K. , Kennedy Christina
Published: July 2012

Azotobacter vinelandii
is a well-studied model system for nitrogen fixation in bacteria. Regulation of nitrogen fixation in
A. vinelandii
is independent of NtrB/NtrC, a conserved nitrogen regulatory system in proteobacteria. Previous work showed that an
ntrC
mutation in
A. vinelandii
resulted in a loss of induction of assimilatory nitrate and nitrite reductases encoded by the
nasAB
operon. In addition to NtrC, several other proteins, including NasT, a protein containing a potential RNA-binding domain ANTAR (
A
miR and
N
asR
t
ranscription
a
ntitermination
r
egulators), have been implicated in
nasAB
regulation. In this work, we characterize the sequence upstream of
nasA
and identify several DNA sequence elements, including two potential NtrC binding sites and a putative intrinsic transcriptional terminator upstream of
nasA
that are potentially involved in
nasAB
regulation. Our analyses confirm that the
nasAB
promoter,
P
nasA
, is under NtrC control. However, unlike NtrC-regulated promoters in enteric bacteria,
P
nasA
shows high activity in the presence of ammonium; in addition, the
P
nasA
activity is altered in the
nifA
gene mutation background. We discuss the implication of these results on NtrC-mediated regulation in
A. vinelandii
. Our study provides direct evidence that induction of
nasAB
is regulated by NasT-mediated antitermination, which occurs within the leader region of the operon. The results also support the hypothesis that NasT binds the promoter proximal hairpin of
nasAB
for its regulatory function, which contributes to the understanding of the regulatory mechanism of ANTAR-containing antiterminators.
Multiple Transcription-Activating Sequences Regulate the RsmZ Regulatory Small RNA of Pseudomonas brassicacearum
Authors: Lalaouna D. , Fochesato S. , Barakat M. , Ortet P. , Achouak W.
Published: July 2012

ThemutS-rpoSregion is known to be a highly polymorphic segment of the chromosome owing to horizontal gene transfer and evolutionary processes. InPseudomonas,mutS-fdxA-rsmZ-rpoSorganization is highly conserved, as well as the promoter region of the RsmZ small RNA (sRNA)-encoding gene. One exception to this conservation is inPseudomonas brassicacearum, where a 308-nucleotide (nt) sequence, predicted to form a hairpin structure in single-stranded DNA (ssDNA), is inserted between therpoSandrsmZgenes. Using MEME software, we identified nine consensus motifs in thersmZpromoter region of 16 sequencedPseudomonasgenomes. We observed that an upstream activation sequence (UAS) and an M1 motif (located between the −10 promoter element and the UAS) are shared among examinedPseudomonasgenomes. A third motif, the M2 motif, is localized within the coding sequence of therpoSgene. Constructs fusing the different identified motifs to thelacZreporter were produced. Ourin vivoanalysis of thersmZ-activating elements indicates that the palindromic UAS located 180 bp upstream of thersmZtranscriptional start inP. brassicacearumNFM 421 is essential, but not sufficient, for fullrsmZexpression. Here, we demonstrate a role for the three motifs in the activation of thersmZgene, and we hypothesize the role of additional transcriptional factors, along with the DNA structuring role of the hairpin in the complex network controlling the expression ofrsmZ.
CbrA Is a Flavin Adenine Dinucleotide Protein That Modifies the Escherichia coli Outer Membrane and Confers Specific Resistance to Colicin M
Authors: Helbig Stephanie , Hantke Klaus , Ammelburg Moritz , Braun Volkmar
Published: July 2012

Colicin M (Cma) is a protein toxin produced byEscherichia colithat kills sensitiveE. colicells by inhibiting murein biosynthesis in the periplasm. Recombinant plasmids carryingcbrA(formerlyyidS) strongly increased resistance of cells to Cma, whereas deletion ofcbrAincreased Cma sensitivity. Transcription ofcbrAis positively controlled by the two-component CreBC system. A ΔcreBmutant was highly Cma sensitive because little CbrA was synthesized. Treatment of CbrA-overproducing cells by osmotic shock failed to render cells Cma sensitive because the cells were resistant to osmotic shock. In a natural environment with a growth-limiting nutrient supply, cells producing CbrA defend themselves against colicin M synthesized by competing cells. Isolated CbrA is a protein with noncovalently bound flavin adenine dinucleotide. Sequence comparison and structure prediction assign the closest relative of CbrA with a known crystal structure as digeranylgeranyl-glycerophospholipid reductase ofThermoplasma acidophilum. CbrA is found inEscherichia coli,Citrobacter, andSalmonella bongoribut not in other enterobacteria. The next homologs with the highest identity (over 50%) are found in the anaerobicClostridium botulinumgroup 1 and a few otherFirmicutes.
TolC-Dependent Secretion of an Ankyrin Repeat-Containing Protein of Rickettsia typhi
Authors: Kaur Simran J. , Rahman M. Sayeedur , Ammerman Nicole C. , Beier-Sexton Magda , Ceraul Shane M. , Gillespie Joseph J. , Azad Abdu F.
Published: July 2012

Rickettsia typhi, the causative agent of murine (endemic) typhus, is an obligate intracellular pathogen with a life cycle involving both vertebrate and invertebrate hosts. In this study, we characterized a gene (RT0218) encoding a C-terminal ankyrin repeat domain-containing protein, namedRickettsiaankyrinrepeatprotein 1 (RARP-1), and identified it as a secreted effector protein ofR. typhi.RT0218showed differential transcript abundance at various phases ofR. typhiintracellular growth. RARP-1 was secreted byR. typhiinto the host cytoplasm duringin vitroinfection of mammalian cells. Transcriptional analysis revealed thatRT0218was cotranscribed with adjacent genesRT0217(hypothetical protein) andRT0216(TolC) as a single polycistronic mRNA. Given one of its functions as a facilitator of extracellular protein secretion in some Gram-negative bacterial pathogens, we tested the possible role of TolC in the secretion of RARP-1. UsingEscherichia coliC600 and an isogenictolCinsertion mutant as surrogate hosts, our data demonstrate that RARP-1 is secreted in a TolC-dependent manner. Deletion of either the N-terminal signal peptide or the C-terminal ankyrin repeats abolished RARP-1 secretion by wild-typeE. coli. Importantly, expression ofR. typhitolCin theE. colitolCmutant restored the secretion of RARP-1, suggesting that TolC has a role in RARP-1 translocation across the outer membrane. This work implies that the TolC component of the putative type 1 secretion system ofR. typhiis involved in the secretion process of RARP-1.
Functional Analysis of Bacillus subtilis Genes Involved in the Biosynthesis of 4-Thiouridine in tRNA
Authors: Rajakovich Lauren J. , Tomlinson John , Dos Santos Patricia C.
Published: July 2012

ThiI has been identified as an essential enzyme involved in the biosynthesis of thiamine and the tRNA thionucleoside modification, 4-thiouridine. InEscherichia coliandSalmonella enterica, ThiI acts as a sulfurtransferase, receiving the sulfur donated from the cysteine desulfurase IscS and transferring it to the target molecule or additional sulfur carrier proteins. However, inBacillus subtilisand most species from theFirmicutesphylum, ThiI lacks the rhodanese domain that contains the site responsible for the sulfurtransferase activity. The lack of the gene encoding for a canonical IscS cysteine desulfurase and the presence of a short sequence of ThiI in these bacteria pointed to mechanistic differences involving sulfur trafficking reactions in both biosynthetic pathways. Here, we have carried out functional analysis ofB. subtilisthiIand the adjacent gene,nifZ, encoding for a cysteine desulfurase. Gene inactivation experiments inB. subtilisindicate the requirement of ThiI and NifZ for the biosynthesis of 4-thiouridine, but not thiamine.In vitrosynthesis of 4-thiouridine by ThiI and NifZ, along with labeling experiments, suggests the occurrence of an alternate transient site for sulfur transfer, thus obviating the need for a rhodanese domain.In vivocomplementation studies inE. coliIscS- or ThiI-deficient strains provide further support for specific interactions between NifZ and ThiI. These results are compatible with the proposal thatB. subtilisNifZ and ThiI utilize mechanistically distinct and mutually specific sulfur transfer reactions.
Variation in safety culture dimensions within and between US and Swiss Hospital Units: an exploratory study
Authors: Schwendimann René , Zimmermann Natalie , Küng Kaspar , Ausserhofer Dietmar , Sexton Bryan
Published: July 2012

Background

The purpose of this study was to explore the variability in safety culture dimensions within and between Swiss and US clinical areas.

Methods

Cross-sectional design. The 30-item Safety Attitudes Questionnaire (SAQ) was distributed in 2009 to clinicians involved in direct patient care in medical and surgical units of two Swiss and 10 US hospitals. At the unit level, results were calculated as the percentage of respondents within a unit who reported positive perceptions. MANOVA and ANOVA were used to test for differences between and within US and Swiss hospital units.

Results

In total, 1370 clinicians from 54 hospital units responded (response rate 84%), including 1273 nurses and 97 physicians. In Swiss hospital units, three SAQ dimensions were lower (safety climate, p=0.024; stress recognition, p<0.001; and perceptions of management, p<0.001) compared with US hospital units.

There was significant variability in four out of six SAQ dimensions (teamwork climate, safety climate, job satisfaction and perceptions of unit management) (p<0.001). Moreover, intraclass correlations indicate that these four dimensions vary more at the unit level than hospital level, whereas stress recognition and working conditions vary more at the hospital level.

Conclusions

The authors found differences in SAQ dimensions at the country, hospital and unit levels. The general emphases placed on teamwork and safety climate in quality and safety efforts appear to be highlighting dimensions that vary more at the unit than hospital level. They suggest that patient safety improvement interventions target unit level changes, and they support the emphasis being placed on teamwork and safety climate, as these vary significantly at the unit level across countries.
The importance of low-risk HPV infection for the risk of abnormal cervical cytology/histology in more than 40 000 Danish women
Authors: Nielsen Ann , Iftner Thomas , Nørgaard Mia , Munk Christian , Junge Jette , Kjaer Susanne Krüger
Published: July 2012

Objectives

To estimate the age and type-specific distribution of low-risk (LR) human papillomavirus (HPV) types in cervical samples from women in the general population and to assess the distribution of LR-HPV without the coexistence of high-risk HPV types in different cytology and histology categories.

Methods

In a cross-sectional study, liquid-based cytology samples (SurePath) were collected over a 3-year period. The samples were HPV tested by Hybrid Capture II (HC2; Digene) and genotyped using a PCR-based assay (INNO-LiPAv2; Innogenetics Inc.). A total of 40 382 women (14–95 years of age) were included in the study. By linkage with the nationwide Pathology Data Bank, the HPV test results were directly linked to cytological diagnoses made from the same samples and to subsequent histology results.

Results

Overall, 2790 women (6.9%) tested positive for LR-HPV types, with HPV6 and HPV70 being the most frequent types detected, whereas HPV11 was uncommon. The highest prevalence was observed in the youngest age group (≤19 years). The LR-HPV prevalence was 6.3% in women with normal cytology, 33.1% in atypical squamous cells of undetermined significance (ASCUS), 19.6% in low-grade squamous intraepithelial lesion and 12.7% in those with high-grade squamous intraepithelial lesion. When considering women with LR-HPV alone, the prevalence was 2.0% (normal cytology), 11.3% (ASCUS), 2.6% (low-grade squamous intraepithelial lesion) and 0.7% in women with high-grade squamous intraepithelial lesion, respectively. A similar pattern was observed in relation to the histological diagnoses with the majority of LR-HPV infections detected in CIN1 lesions (24.7%).

Conclusions

LR-HPV types alone are relatively common in ASCUS, whereas LR-HPV types without coexisting high-risk HPV types are virtually never detected in severe cervical lesions.
Exploring staff attitudes to routine HIV testing in non-traditional settings: a qualitative study in four healthcare facilities
Authors: Thornton Alicia Claire , Rayment Michael , Elam Gillian , Atkins Mark , Jones Rachel , Nardone Anthony , Roberts Patrick , Tenant-Flowers Melinda , Anderson Jane , Sullivan Ann Kathleen ,   on behalf of the HINTS Study Group
Published: July 2012

Objectives

To explore staff attitudes towards and experiences of the implementation of routine HIV testing in four healthcare settings in areas of high diagnosed HIV prevalence.

Methods

As part of the HINTS (HIV Testing in Non-traditional Settings) Study, routine offer of an HIV test to all 16–65-year-old patients was conducted for 3 months in an emergency department, an acute admissions unit, a dermatology outpatients department and a primary care practice. The authors conducted focus groups with staff at these sites before and after the implementation of testing. Transcriptions of focus groups were subject to thematic analysis.

Results

Four major themes were identified: the stigma of HIV and exceptionalisation of HIV testing as a condition; the use of routine testing compared with a targeted strategy as a means of improving the acceptability of testing; the need for an additional skill set to conduct HIV testing; and the existence within these particular settings of operational barriers to the implementation of HIV testing. Specifically, the time taken to conduct testing and management of results were seen by staff as barriers. There was a clear change in staff perception before and after implementation of testing as staff became aware of the high level of patient acceptability.

Conclusions

The routine offer of HIV testing in general medical services is feasible, but implementation requires training and support for staff, which may be best provided by the local sexual health service.
TRANSPORT VIA CLASSICAL PERCOLATION AT QUANTUM HALL PLATEAU TRANSITIONS
Authors: FLÖSER MARTINA , FLORENS SERGE , CHAMPEL THIERRY
Published: July 2012

We consider transport properties of disordered two-dimensional electron gases under high perpendicular magnetic field, focusing in particular on the peak longitudinal conductivity [Formula: see text] at the quantum Hall plateau transition. We use a local conductivity model, valid at temperatures high enough such that quantum tunneling is suppressed, taking into account the random drift motion of the electrons in the disordered potential landscape and inelastic processes provided by electron-phonon scattering. A diagrammatic solution of this problem is proposed, which leads to a rich interplay of conduction mechanisms, where classical percolation effects play a prominent role. The scaling function for [Formula: see text] is derived in the high temperature limit, which can be used to extract universal critical exponents of classical percolation from experimental data.
miR-140-3p regulation of TNF-α-induced CD38 expression in human airway smooth muscle cells
Authors: Jude Joseph A. , Dileepan Mythili , Subramanian Subbaya , Solway Julian , Panettieri Reynold A. , Walseth Timothy F. , Kannan Mathur S.
Published: July 2012

CD38, a membrane protein expressed in airway smooth muscle (ASM) cells, plays a role in cellular Ca2+ dynamics and ASM contractility. In human ASM (HASM) cells, TNF-α induces CD38 expression through activation of MAPKs, NF-κB, and AP-1, and its expression is differentially elevated in cells from asthmatic patients compared with cells from nonasthmatic subjects. The CD38 3′-untranslated region (UTR) has targets for miR-140-3p. We hypothesized that miR-140-3p regulates CD38 expression in HASM cells by altering CD38 mRNA stability. Basal and TNF-α-induced expression of miR-140-3p was determined in nonasthmatic ASM (NAASM) and asthmatic ASM (AASM) cells. NAASM and AASM cells were transfected with control, miR-140-3p mimic, or miR-140-3p antagomirs, and CD38 expression and CD38 mRNA stability were determined. Luciferase reporter assays were used to determine miR-140-3p binding to the CD38 3′-UTR. Activation of p38, ERK, and JNK MAPKs, NF-κB, and AP-1 was determined in miR-140-3p mimic-transfected NAASM. TNF-α attenuated miR-140-3p expression in NAASM and AASM cells, but at a greater magnitude in AASM cells. CD38 mRNA expression was attenuated by miR-140-3p mimic at comparable magnitude in NAASM and AASM cells. Mutated miR-140-3p target on the CD38 3′-UTR reversed the inhibition of luciferase activity by miR-140-3p mimic. CD38 mRNA stability was unaltered by miR-140-3p mimic in NAASM or AASM cells following arrest of transcription. TNF-α-induced activation of p38 MAPK and NF-κB was attenuated by miR-140-3p mimic. The findings indicate that miR-140-3p modulates CD38 expression in HASM cells through direct binding to the CD38 3′-UTR and indirect mechanisms involving activation of p38 MAPK and NF-κB. Furthermore, indirect mechanisms appear to play a major role in the regulation of CD38 expression.
Adenosine triphosphate regulates NADPH oxidase activity leading to hydrogen peroxide production and COX-2/PGE2 expression in A549 cells
Authors: Lin Chih-Chung , Lee I-Ta , Wu Wan-Ling , Lin Wei-Ning , Yang Chuen-Mao
Published: July 2012

Non-small cell lung carcinoma (NSCLC) accounts for most of all lung cancers, which is the leading cause of mortality in human beings. High level of cyclooxygenase-2 (COX-2) is one of the features of NSCLC and related to the low survival rate of NSCLC. However, whether extracellular nucleotides releasing from stressed resident tissues contributes to the expression of COX-2 remains unclear. Here, we showed that stimulation of A549 cells by adenosine 5′- O-(3-thiotriphosphate) (ATPγS) led to an increase in COX-2 gene expression and prostaglandin E2 (PGE2) synthesis, revealed by Western blotting, RT-PCR, promoter assay, and enzyme-linked immunosorbent assay. In addition, ATPγS induced intracellular reactive oxygen species (ROS) generation through the activation of NADPH oxidase. The increase of ROS level resulted in activation of the c-Src/epidermal growth factor receptor (EGFR)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/nuclear factor (NF)-κB cascade. We also found that activated Akt was translocated into the nucleus and recruited with NF-κB and p300 to form a complex. Thus, activation of p300 modulated the acetylation of histone H4 via the NADPH oxidase/c-Src/EGFR/PI3K/Akt/NF-κB cascade stimulated by ATPγS. Our results are the first to show a novel role of NADPH oxidase-dependent Akt/p65/p300 complex formation that plays a key role in regulating COX-2/PGE2 expression in ATPγS-treated A549 cells. Taken together, we demonstrated that ATPγS stimulated activation of NADPH oxidase, resulting in generation of ROS, which then activated the downstream c-Src/EGFR/PI3K/Akt/NF-κB/p300 cascade to regulate the expression of COX-2 and synthesis of PGE2 in A549 cells. Understanding the regulation of COX-2 expression and PGE2 release by ATPγS on A549 cells may provide potential therapeutic targets of NSCLC.
Glycogen synthase kinase-3β/β-catenin signaling regulates neonatal lung mesenchymal stromal cell myofibroblastic differentiation
Authors: Popova Antonia P. , Bentley J. Kelley , Anyanwu Anuli C. , Richardson Michelle N. , Linn Marisa J. , Lei Jing , Wong Elizabeth J. , Goldsmith Adam M. , Pryhuber Gloria S. , Hershenson Marc B.
Published: July 2012

In bronchopulmonary dysplasia (BPD), alveolar septa are thickened with collagen and α-smooth muscle actin-, transforming growth factor (TGF)-β-positive myofibroblasts. We examined the biochemical mechanisms underlying myofibroblastic differentiation, focusing on the role of glycogen synthase kinase-3β (GSK-3β)/β-catenin signaling pathway. In the cytoplasm, β-catenin is phosphorylated on the NH2 terminus by constitutively active GSK-3β, favoring its degradation. Upon TGF-β stimulation, GSK-3β is phosphorylated and inactivated, allowing β-catenin to translocate to the nucleus, where it activates transcription of genes involved in myofibroblastic differentiation. We examined the role of β-catenin in TGF-β1-induced myofibroblastic differentiation of neonatal lung mesenchymal stromal cells (MSCs) isolated from tracheal aspirates of premature infants with respiratory distress. TGF-β1 increased β-catenin expression and nuclear translocation. Transduction of cells with GSK-3β S9A, a nonphosphorylatable, constitutively active mutant that favors β-catenin degradation, blocked TGF-β1-induced myofibroblastic differentiation. Furthermore, transduction of MSCs with ΔN-catenin, a truncation mutant that cannot be phosphorylated on the NH2 terminus by GSK-3β and is not degraded, was sufficient for myofibroblastic differentiation. In vivo, hyperoxic exposure of neonatal mice increases expression of β-catenin in α-smooth muscle actin-positive myofibroblasts. Similar changes were found in lungs of infants with BPD. Finally, low-passage unstimulated MSCs from infants developing BPD showed higher phospho-GSK-3β, β-catenin, and α-actin content compared with MSCs from infants not developing this disease, and phospho-GSK-3β and β-catenin each correlated with α-actin content. We conclude that phospho-GSK-3β/β-catenin signaling regulates α-smooth muscle actin expression, a marker of myofibroblast differentiation, in vitro and in vivo. This pathway appears to be activated in lung mesenchymal cells from patients with BPD.
Existence of 2m − 1 Positive Solutions for Sturm‐Liouville Boundary Value Problems with Linear Functional Boundary Conditions on the Half‐Line
Authors: Sun Yanmei , Zhao Zengqin
Published: July 2012

By using the Leggett‐Williams fixed theorem, we establish the existence of multiple positive solutions for second‐order nonhomogeneous Sturm‐Liouville boundary value problems with linear functional boundary conditions. One explicit example with singularity is presented to demonstrate the application of our main results.
Characterizing Curvilinear Features Using the Localized Normal‐Score Ensemble Kalman Filter
Authors: Zhou Haiyan , Li Liangping , Gómez-Hernández J. Jaime
Published: July 2012

The localized normal‐score ensemble Kalman filter is shown to work for the characterization of non‐multi‐Gaussian distributed hydraulic conductivities by assimilating state observation data. The influence of type of flow regime, number of observation piezometers, and the prior model structure are evaluated in a synthetic aquifer. Steady‐state observation data are not sufficient to identify the conductivity channels. Transient‐state data are necessary for a good characterization of the hydraulic conductivity curvilinear patterns. Such characterization is very good with a dense network of observation data, and it deteriorates as the number of observation piezometers decreases. It is also remarkable that, even when the prior model structure is wrong, the localized normal‐score ensemble Kalman filter can produce acceptable results for a sufficiently dense observation network.
A Real World Report on Intravenous High-Dose and Non-High-Dose Proton-Pump Inhibitors Therapy in Patients with Endoscopically Treated High-Risk Peptic Ulcer Bleeding
Authors: Lu Lung-Sheng , Lin Sheng-Chieh , Kuo Chung-Mou , Tai Wei-Chen , Tseng Po-Lin , Chang Kuo-Chin , Kuo Chung-Huang , Chuah Seng-Kee
Published: July 2012

Background and Study Aims. The optimal dose of intravenous proton-pump inhibitor (PPI) therapy for the prevention of peptic ulcer (PU) rebleeding remains controversial. This study aimed to understand the real world experiences in prescribing high-dose PPI and non-high-dose PPI for preventing rebleeding after endoscopic treatment of high-risk PU.Patients and Methods. A total of 220 subjects who received high-dose and non-high-dose pantoprazole for confirmed acute PU bleeding that were successfully treated endoscopically were enrolled. They were divided into rebleeding (n=177) and non-rebleeding groups (n=43). Randomized matching of the treatment-control group was performed. Patients were randomly selected for non-high-dose and high-dose PPI groups (n=44in each group).Results. Univariate analysis showed, significant variables related to rebleeding were female, higher creatinine levels, and higher Rockall scores (≧6). Before case-control matching, the high-dose PPI group had higher creatinine level, higher percentage of shock at presentation, and higher Rockall scores. After randomized treatment-control matching, no statistical differences were observed for rebleeding rates between the high-dose and non-high-dose groups after case-control matching.Conclusion. This study suggests that intravenous high-dose pantoprazole may not be superior to non-high-dose regimen in reducing rebleeding in high-risk peptic ulcer bleeding after successful endoscopic therapy.
Concomitant Targeting of Tumor Cells and Induction of T-cell Response Synergizes to Effectively Inhibit Trastuzumab-Resistant Breast Cancer
Authors: Wang Qingfei , Li Shau-Hsuan , Wang Hai , Xiao Yi , Sahin Ozgur , Brady Samuel W. , Li Ping , Ge Hailiang , Jaffee Elizabeth M. , Muller William J. , Hortobagyi Gabriel N. , Yu Dihua
Published: July 2012

Trastuzumab is an iconic rationally designed targeted therapy for HER2-positive breast cancers. However, the low response rate and development of resistance call for novel approaches for the treatment of patients. Here, we report that concurrent targeting of tumor cells and activation of T cells in the tumor microenvironment results in a synergistic inhibitory effect on tumor growth and overcomes resistance in two distinct PTEN loss–mediated trastuzumab-resistant mammary tumor mouse models. In vivo combination treatment with HER2/Neu antibody and Akt inhibitor triciribine effectively inhibited tumor growth in both models via inhibiting PI3K/AKT and mitogen-activated protein kinase signaling accompanied by increased T-cell infiltration in the tumor microenvironment. We showed that both CD8+ and CD4+ T cells were essential to the optimal antitumor effect of this combination treatment in an IFN-γ–dependent manner. Importantly, the antitumor activities of HER2/Neu antibody and triciribine combination treatment were further improved when coinhibitory receptor cytotoxic T-lymphocyte–associated antigen 4 was blocked to enhance the T-cell response. Our data indicate that multitargeted combinatorial therapies targeting tumor cells and concomitantly enhancing T-cell response in the tumor microenvironment could cooperate to exert maximal therapeutic activity, suggesting a promising clinical strategy for treating trastuzumab-resistant breast cancers and other advanced malignancies. Cancer Res; 72(17); 4417–28. ©2012 AACR.
Glutamine Deprivation Enhances Antitumor Activity of 3-Bromopyruvate through the Stabilization of Monocarboxylate Transporter-1
Authors: Cardaci Simone , Rizza Salvatore , Filomeni Giuseppe , Bernardini Roberta , Bertocchi Fabio , Mattei Maurizio , Paci Maurizio , Rotilio Giuseppe , Ciriolo Maria Rosa
Published: July 2012

Anticancer drug efficacy might be leveraged by strategies to target certain biochemical adaptations of tumors. Here we show how depriving cancer cells of glutamine can enhance the anticancer properties of 3-bromopyruvate, a halogenated analog of pyruvic acid. Glutamine deprival potentiated 3-bromopyruvate chemotherapy by increasing the stability of the monocarboxylate transporter-1, an effect that sensitized cells to metabolic oxidative stress and autophagic cell death. We further elucidated mechanisms through which resistance to chemopotentiation by glutamine deprival could be circumvented. Overall, our findings offer a preclinical proof-of-concept for how to employ 3-bromopyruvate or other monocarboxylic-based drugs to sensitize tumors to chemotherapy. Cancer Res; 72(17); 4526–36. ©2012 AACR.
Molecular Pathways: Context-Dependent Approaches to Notch Targeting as Cancer Therapy
Authors: Egloff Ann Marie , Grandis Jennifer R.
Published: July 2012

Recent high-throughput genomic sequencing studies of solid tumors, including head and neck squamous cell carcinoma (SCC), ovarian cancer, lung adenocarcinoma, glioblastoma, breast cancer, and lung SCC, have highlighted DNA mutation as a mechanism for aberrant Notch signaling. A primary challenge of targeting Notch for treatment of solid malignancies is determining whether Notch signaling is cancer promoting or tumor suppressing for a specific cancer. We compiled reported Notch receptor and ligand missense and nonsense mutations to glean insights into aberrant Notch signaling. Frequencies of coding mutations differed for the 4 NOTCH genes. A total of 4.7% of tumors harbored NOTCH1 missense or nonsense mutations. NOTCH2, and NOTCH3 had similar overall mutation rates of 1.5% and 1.3%, respectively, whereas NOTCH4 mutations were rarer. Notch ligand genes were rarely mutated. The combined mutation frequency and position spectra of the 4 Notch paralogs across the different cancers provide an opportunity to begin to illuminate the different contributions of each Notch paralog to each tumor type and to identify opportunities for therapeutic targeting. Notch signaling pathway activators and inhibitors are currently in early clinical development for treatment of solid malignancies. Defining the status and consequences of altered Notch signaling will be important for selection of appropriate treatment. Clin Cancer Res; 18(19); 5188–95. ©2012 AACR.