bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of bone-conduction harmonic distortions on hearing thresholds
Authors: Eichenauer Anja , Dillon Harvey , Clinch Barry , Loi Teck
Published: July 2014

This study compares bone conduction (BC) thresholds obtained with two bone vibrators (BV): The Radioear B71 and an advanced BV, the Radioear B81. B81 has less distortion and is capable of higher output levels. Two tests with 20 normal hearing subjects were conducted to determine if the low distortion of B81 offers any advantages for audiometry. Hearing threshold differences between B71 and B81 are only significant at 250 Hz for levels between 20 dB hearing level (HL) and 30 dB HL. At other frequencies and higher levels, where B81 also performs with less distortion than B71, tactile responses interfere before B81 can be advantageous.
More Health for the Money—Toward a More Rigorous Implementation Science
Authors: Kruk Margaret E.
Published: July 2014

Rigorous implementation science can improve efforts to scale up effective health interventions.
Lactobacillus rhamnosus GG Inhibits the Toxic Effects of Staphylococcus aureus on Epidermal Keratinocytes
Authors: Mohammedsaeed Walaa , McBain Andrew J. , Cruickshank Sheena M. , O'Neill Catherine A.
Published: July 2014

Few studies have evaluated the potential benefits of the topical application of probiotic bacteria or material derived from them. We have investigated whether a probiotic bacterium,
Lactobacillus rhamnosus
GG, can inhibit
Staphylococcus aureus
infection of human primary keratinocytes in culture. When primary human keratinocytes were exposed to
S. aureus
, only 25% of the keratinocytes remained viable following 24 h of incubation. However, in the presence of 10
8
CFU/ml of live
L. rhamnosus
GG, the viability of the infected keratinocytes increased to 57% (
P
= 0.01).
L. rhamnosus
GG lysates and spent culture fluid also provided significant protection to keratinocytes, with 65% (
P
= 0.006) and 57% (
P
= 0.01) of cells, respectively, being viable following 24 h of incubation. Keratinocyte survival was significantly enhanced regardless of whether the probiotic was applied in the viable form or as cell lysates 2 h before or simultaneously with (
P
= 0.005) or 12 h after (
P
= 0.01)
S. aureus
infection. However, spent culture fluid was protective only if added before or simultaneously with
S. aureus
. With respect to mechanism, both
L. rhamnosus
GG lysate and spent culture fluid apparently inhibited adherence of
S. aureus
to keratinocytes by competitive exclusion, but only viable bacteria or the lysate could displace
S. aureus
(
P
= 0.04 and 0.01, respectively). Furthermore, growth of
S. aureus
was inhibited by either live bacteria or lysate but not spent culture fluid. Together, these data suggest at least two separate activities involved in the protective effects of
L. rhamnosus
GG against
S. aureus
, growth inhibition and reduction of bacterial adhesion.
Metatranscriptomic Analysis of Arctic Peat Soil Microbiota
Authors: Tveit Alexander T. , Urich Tim , Svenning Mette M.
Published: July 2014

Recent advances in meta-omics and particularly metatranscriptomic approaches have enabled detailed studies of the structure and function of microbial communities in many ecosystems. Molecular analyses of peat soils, ecosystems important to the global carbon balance, are still challenging due to the presence of coextracted substances that inhibit enzymes used in downstream applications. We sampled layers at different depths from two high-Arctic peat soils in Svalbard for metatranscriptome preparation. Here we show that enzyme inhibition in the preparation of metatranscriptomic libraries can be circumvented by linear amplification of diluted template RNA. A comparative analysis of mRNA-enriched and nonenriched metatranscriptomes showed that mRNA enrichment resulted in a 2-fold increase in the relative abundance of mRNA but biased the relative distribution of mRNA. The relative abundance of transcripts for cellulose degradation decreased with depth, while the transcripts for hemicellulose debranching increased, indicating that the polysaccharide composition of the peat was different in the deeper and older layers. Taxonomic annotation revealed that
Actinobacteria
and
Bacteroidetes
were the dominating polysaccharide decomposers. The relative abundances of 16S rRNA and mRNA transcripts of methanogenic
Archaea
increased substantially with depth. Acetoclastic methanogenesis was the dominating pathway, followed by methanogenesis from formate. The relative abundances of 16S rRNA and mRNA assigned to the methanotrophic
Methylococcaceae
, primarily
Methylobacter
, increased with depth. In conclusion, linear amplification of total RNA and deep sequencing constituted the preferred method for metatranscriptomic preparation to enable high-resolution functional and taxonomic analyses of the active microbiota in Arctic peat soil.
SmoXYB1C1Z of Mycobacterium sp. Strain NBB4: a Soluble Methane Monooxygenase (sMMO)-Like Enzyme, Active on C
2
to C
4
Alkanes and Alkenes
Authors: Martin Kiri E. , Ozsvar Jazmin , Coleman Nicholas V.
Published: July 2014

Monooxygenase (MO) enzymes initiate the aerobic oxidation of alkanes and alkenes in bacteria. A cluster of MO genes (
smoXYB1C1Z
) of thus-far-unknown function was found previously in the genomes of two
Mycobacterium
strains (NBB3 and NBB4) which grow on hydrocarbons. The predicted Smo enzymes have only moderate amino acid identity (30 to 60%) to their closest homologs, the soluble methane and butane MOs (sMMO and sBMO), and the
smo
gene cluster has a different organization from those of sMMO and sBMO. The
smoXYB1C1Z
genes of NBB4 were cloned into pMycoFos to make pSmo, which was transformed into
Mycobacterium smegmatis
mc
2
-155. Cells of mc
2
-155(pSmo) metabolized C
2
to C
4
alkanes, alkenes, and chlorinated hydrocarbons. The activities of mc
2
-155(pSmo) cells were 0.94, 0.57, 0.12, and 0.04 nmol/min/mg of protein with ethene, ethane, propane, and butane as substrates, respectively. The mc
2
-155(pSmo) cells made epoxides from ethene, propene, and 1-butene, confirming that Smo was an oxygenase. Epoxides were not produced from larger alkenes (1-octene and styrene). Vinyl chloride and 1,2-dichloroethane were biodegraded by cells expressing Smo, with production of inorganic chloride. This study shows that Smo is a functional oxygenase which is active against small hydrocarbons.
M. smegmatis
mc
2
-155(pSmo) provides a new model for studying sMMO-like monooxygenases.
Biosynthesis of Novel Pyoverdines by Domain Substitution in a Nonribosomal Peptide Synthetase of Pseudomonas aeruginosa
Authors: Calcott Mark J. , Owen Jeremy G. , Lamont Iain L. , Ackerley David F.
Published: July 2014

Pyoverdine is a fluorescent nonribosomal peptide siderophore made by fluorescent pseudomonads. The
Pseudomonas aeruginosa
nonribosomal peptide synthetase (NRPS) PvdD contains two modules that each incorporate an
l
-threonine residue at the C-terminal end of pyoverdine. In an attempt to generate modified pyoverdine peptides, we substituted alternative-substrate-specifying adenylation (A) and peptide bond-catalyzing condensation (C) domains into the second module of PvdD. When just the A domain was substituted, the resulting strains produced only wild-type pyoverdine—at high levels if the introduced A domain specified threonine or at trace levels otherwise. The high levels of pyoverdine synthesis observed whenever the introduced A domain specified threonine indicated that these nonnative A domains were able to communicate effectively with the PvdD C domain. Moreover, the unexpected observation that non-threonine-specifying A domains nevertheless incorporated threonine into pyoverdine suggests that the native PvdD C domain exhibited stronger selectivity than these A domains for the incorporated amino acid substrate (i.e., misactivation of a threonine residue by the introduced A domains was more frequent than misincorporation of a nonthreonine residue by the PvdD C domain). In contrast, substitution of both the C and A domains of PvdD generated high yields of rationally modified pyoverdines in two instances, these pyoverdines having either a lysine or a serine residue in place of the terminal threonine. However, C-A domain substitution more commonly yielded a truncated peptide product, likely due to stalling of synthesis on a nonfunctional recombinant NRPS template.
Directed Evolution of Brain-Derived Neurotrophic Factor for Improved Folding and Expression in Saccharomyces cerevisiae
Authors: Burns Michael L. , Malott Thomas M. , Metcalf Kevin J. , Hackel Benjamin J. , Chan Jonah R. , Shusta Eric V.
Published: July 2014

Brain-derived neurotrophic factor (BDNF) plays an important role in nervous system function and has therapeutic potential. Microbial production of BDNF has resulted in a low-fidelity protein product, often in the form of large, insoluble aggregates incapable of binding to cognate TrkB or p75 receptors. In this study, employing
Saccharomyces cerevisiae
display and secretion systems, it was found that BDNF was poorly expressed and partially inactive on the yeast surface and that BDNF was secreted at low levels in the form of disulfide-bonded aggregates. Thus, for the purpose of increasing the compatibility of yeast as an expression host for BDNF, directed-evolution approaches were employed to improve BDNF folding and expression levels. Yeast surface display was combined with two rounds of directed evolution employing random mutagenesis and shuffling to identify BDNF mutants that had 5-fold improvements in expression, 4-fold increases in specific TrkB binding activity, and restored p75 binding activity, both as displayed proteins and as secreted proteins. Secreted BDNF mutants were found largely in the form of soluble homodimers that could stimulate TrkB phosphorylation in transfected PC12 cells. Site-directed mutagenesis studies indicated that a particularly important mutational class involved the introduction of cysteines proximal to the native cysteines that participate in the BDNF cysteine knot architecture. Taken together, these findings show that yeast is now a viable alternative for both the production and the engineering of BDNF.
Transcriptome-Based Analysis of the Pantoea stewartii Quorum-Sensing Regulon and Identification of EsaR Direct Targets
Authors: Ramachandran Revathy , Burke Alison Kernell , Cormier Guy , Jensen Roderick V. , Stevens Ann M.
Published: July 2014

Pantoea
stewartii
subsp.
stewartii
is a proteobacterium that causes Stewart's wilt disease in corn plants. The bacteria form a biofilm in the xylem of infected plants and produce capsule that blocks water transport, eventually causing wilt. At low cell densities, the quorum-sensing (QS) regulatory protein EsaR is known to directly repress expression of
esaR
itself as well as the genes for the capsular synthesis operon transcription regulator,
rcsA
, and a 2,5-diketogluconate reductase,
dkgA
. It simultaneously directly activates expression of genes for a putative small RNA,
esaS
, the glycerol utilization operon,
glpFKX
, and another transcriptional regulator,
lrhA
. At high bacterial cell densities, all of this regulation is relieved when EsaR binds an acylated homoserine lactone signal, which is synthesized constitutively over growth. QS-dependent gene expression is critical for the establishment of disease in the plant. However, the identity of the full set of genes controlled by EsaR/QS is unknown. A proteomic approach previously identified around 30 proteins in the QS regulon. In this study, a whole-transcriptome, next-generation sequencing analysis of rRNA-depleted RNA from QS-proficient and -deficient
P. stewartii
strains was performed to identify additional targets of EsaR. EsaR-dependent transcriptional regulation of a subset of differentially expressed genes was confirmed by quantitative reverse transcription-PCR (qRT-PCR). Electrophoretic mobility shift assays demonstrated that EsaR directly bound 10 newly identified target promoters. Overall, the QS regulon of
P. stewartii
orchestrates three major physiological responses: capsule and cell envelope biosynthesis, surface motility and adhesion, and stress response.
Comprehensive Comparison of Cultivable Norovirus Surrogates in Response to Different Inactivation and Disinfection Treatments
Authors: Cromeans Theresa , Park Geun Woo , Costantini Veronica , Lee David , Wang Qiuhong , Farkas Tibor , Lee Alvin , Vinjé Jan
Published: July 2014

Human norovirus is the leading cause of epidemic and sporadic acute gastroenteritis. Since no cell culture method for human norovirus exists, cultivable surrogate viruses (CSV), including feline calicivirus (FCV), murine norovirus (MNV), porcine enteric calicivirus (PEC), and Tulane virus (TuV), have been used to study responses to inactivation and disinfection methods. We compared the levels of reduction in infectivities of CSV and Aichi virus (AiV) after exposure to extreme pHs, 56°C heating, alcohols, chlorine on surfaces, and high hydrostatic pressure (HHP), using the same matrix and identical test parameters for all viruses, as well as the reduction of human norovirus RNA levels under these conditions. At pH 2, FCV was inactivated by 6 log
10
units, whereas MNV, TuV, and AiV were resistant. All CSV were completely inactivated at 56°C within 20 min. MNV was inactivated 5 log
10
units by alcohols, in contrast to 2 and 3 log
10
units for FCV and PEC, respectively. TuV and AiV were relatively insensitive to alcohols. FCV was reduced 5 log
10
units by 1,000 ppm chlorine, in contrast to 1 log
10
unit for the other CSV. All CSV except FCV, when dried on stainless steel surfaces, were insensitive to 200 ppm chlorine. HHP completely inactivated FCV, MNV, and PEC at ≥300 MPa, and TuV at 600 MPa, while AiV was completely resistant to HHP up to 800 MPa. By reverse transcription-quantitative PCR (RT-qPCR), genogroup I (GI) noroviruses were more sensitive than GII noroviruses to alcohols, chlorine, and HHP. Although inactivation profiles were variable for each treatment, TuV and MNV were the most resistant CSV overall and therefore are the best candidates for studying the public health outcomes of norovirus infections.
Influence of Populus Genotype on Gene Expression by the Wood Decay Fungus Phanerochaete chrysosporium
Authors: Gaskell Jill , Marty Amber , Mozuch Michael , Kersten Philip J. , Splinter BonDurant Sandra , Sabat Grzegorz , Azarpira Ali , Ralph John , Skyba Oleksandr , Mansfield Shawn D. , Blanchette Robert A. , Cullen Dan
Published: July 2014

We examined gene expression patterns in the lignin-degrading fungusPhanerochaete chrysosporiumwhen it colonizes hybrid poplar (Populus alba×tremula) and syringyl (S)-rich transgenic derivatives. A combination of microarrays and liquid chromatography-tandem mass spectrometry (LC-MS/MS) allowed detection of a total of 9,959 transcripts and 793 proteins. Comparisons ofP. chrysosporiumtranscript abundance in medium containing poplar or glucose as a sole carbon source showed 113 regulated genes, 11 of which were significantly higher (>2-fold,P< 0.05) in transgenic line 64 relative to the parental line. Possibly related to the very large amounts of syringyl (S) units in this transgenic tree (94 mol% S), several oxidoreductases were among the upregulated genes. Peptides corresponding to a total of 18 oxidoreductases were identified in medium consisting of biomass from line 64 or 82 (85 mol% S) but not in the parental clone (65 mol% S). These results demonstrate thatP. chrysosporiumgene expression patterns are substantially influenced by lignin composition.
Factors Limiting the Spread of the Protective Symbiont Hamiltonella defensa in Aphis craccivora Aphids
Authors: Dykstra Hannah R. , Weldon Stephanie R. , Martinez Adam J. , White Jennifer A. , Hopper Keith R. , Heimpel George E. , Asplen Mark K. , Oliver Kerry M.
Published: July 2014

Many insects are associated with heritable symbionts that mediate ecological interactions, including host protection against natural enemies. The cowpea aphid,
Aphis craccivora
, is a polyphagous pest that harbors
Hamiltonella defensa
, which defends against parasitic wasps. Despite this protective benefit, this symbiont occurs only at intermediate frequencies in field populations. To identify factors constraining
H. defensa
invasion in
Ap. craccivora
, we estimated symbiont transmission rates, performed fitness assays, and measured infection dynamics in population cages to evaluate effects of infection. Similar to results with the pea aphid,
Acyrthosiphon pisum
, we found no consistent costs to infection using component fitness assays, but we did identify clear costs to infection in population cages when no enemies were present. Maternal transmission rates of
H. defensa
in
Ap. craccivora
were high (ca. 99%) but not perfect. Transmission failures and infection costs likely limit the spread of protective
H. defensa
in
Ap. craccivora
. We also characterized several parameters of
H. defensa
infection potentially relevant to the protective phenotype. We confirmed the presence of
H. defensa
in aphid hemolymph, where it potentially interacts with endoparasites, and performed real-time quantitative PCR (qPCR) to estimate symbiont and phage abundance during aphid development. We also examined strain variation of
H. defensa
and its bacteriophage at multiple loci, and despite our lines being collected in different regions of North America, they were infected with a nearly identical strains of
H. defensa
and APSE4 phage. The limited strain diversity observed for these defensive elements may result in relatively static protection profile for this defensive symbiosis.
Hydrogen Photoproduction by Immobilized N
2
-Fixing Cyanobacteria: Understanding the Role of the Uptake Hydrogenase in the Long-Term Process
Authors: Kosourov Sergey , Leino Hannu , Murukesan Gayathri , Lynch Fiona , Sivonen Kaarina , Tsygankov Anatoly A. , Aro Eva-Mari , Allahverdiyeva Yagut
Published: July 2014

We have investigated two approaches to enhance and extend H
2
photoproduction yields in heterocystous, N
2
-fixing cyanobacteria entrapped in thin alginate films. In the first approach, periodic CO
2
supplementation was provided to alginate-entrapped, N-deprived cells. N deprivation led to the inhibition of photosynthetic activity in vegetative cells and the attenuation of H
2
production over time. Our results demonstrated that alginate-entrapped Δ
hupL
cells were considerably more sensitive to high light intensity, N deficiency, and imbalances in C/N ratios than wild-type cells. In the second approach,
Anabaena
strain PCC 7120, its Δ
hupL
mutant, and
Calothrix
strain 336/3 films were supplemented with N
2
by periodic treatments of air, or air plus CO
2
. These treatments restored the photosynthetic activity of the cells and led to a high level of H
2
production in
Calothrix
336/3 and Δ
hupL
cells (except for the treatment air plus CO
2
) but not in the
Anabaena
PCC 7120 strain (for which H
2
yields did not change after air treatments). The highest H
2
yield was obtained by the air treatment of Δ
hupL
cells. Notably, the supplementation of CO
2
under an air atmosphere led to prominent symptoms of N deficiency in the Δ
hupL
strain but not in the wild-type strain. We propose that uptake hydrogenase activity in heterocystous cyanobacteria not only supports nitrogenase activity by removing excess O
2
from heterocysts but also indirectly protects the photosynthetic apparatus of vegetative cells from photoinhibition, especially under stressful conditions that cause an imbalance in the C/N ratio in cells.
Exopolysaccharides Synthesized by Lactobacillus reuteri Protect against Enterotoxigenic Escherichia coli in Piglets
Authors: Chen Xiao Yan , Woodward Adrienne , Zijlstra Ruurd T. , Gänzle Michael G.
Published: July 2014

Enterotoxigenic
Escherichia coli
(ETEC) is a major cause of diarrhea in piglets; ETEC cells colonize the intestinal mucosa with adhesins and deliver toxins that cause fluid loss. This study determined the antiadhesive properties of bacterial exopolysaccharides (reuteran and levan) and related glycans (dextran and inulin) in a small intestinal segment perfusion (SISP) model. The SISP model used 10 jejunal segments from 5-week-old piglets. Five segments were infected with ETEC expressing K88 fimbriae (ETEC K88), while five segments were treated with saline. Every two segments (ETEC and non-ETEC infected) were infused with 65 ml of 10 g liter
−1
of glycans or saline (control) for 8 h. High-resolution melting-curve (HRM) quantitative PCR (qPCR) indicated that
E. coli
is the dominant bacterium in infected segments, while other bacteria were predominant in noninfected segments. Infection by ETEC K88 was also verified by qPCR; gene copy numbers of K88 fimbriae and the heat-labile toxin (LT) in mucosal scrapings and outflow fluid of infected segments were significantly higher than those in noninfected segments. Genes coding for K88 fimbriae and LT were also detected in noninfected segments. LT amplicons from infected and noninfected segments were 99% identical over 481 bp, demonstrating the presence of autochthonous ETEC K88. All glycans reduced fluid loss caused by ETEC K88 infection. Reuteran tended (
P
= 0.06) to decrease ETEC K88 levels in mucosal scraping sample, as judged by qPCR. Fluorescent
in situ
hybridization analysis demonstrated that reuteran significantly (
P
= 0.012) decreased levels of adherent ETEC K88. Overall, reuteran may prevent piglet diarrhea by reducing adhesion of ETEC K88.
Effect of Lineage-Specific Metabolic Traits of Lactobacillus reuteri on Sourdough Microbial Ecology
Authors: Lin Xiaoxi B. , Gänzle Michael G.
Published: July 2014

This study determined the effects of specific metabolic traits of
Lactobacillus reuteri
on its competitiveness in sourdoughs. The competitiveness of lactobacilli in sourdough generally depends on their growth rate; acid resistance additionally contributes to competitiveness in sourdoughs with long fermentation times. Glycerol metabolism via glycerol dehydratase (
gupCDE
) accelerates growth by the regeneration of reduced cofactors; glutamate metabolism via glutamate decarboxylase (
gadB
) increases acid resistance by generating a proton motive force. Glycerol and glutamate metabolisms are lineage-specific traits in
L. reuteri
; therefore, this study employed glycerol dehydratase-positive sourdough isolates of human-adapted
L. reuteri
lineage I, glutamate decarboxylase-positive strains of rodent-adapted
L. reuteri
lineage II, as well as mutants with deletions in
gadB
or
gupCDE
. The competitivenesses of the strains were quantified by inoculation of wheat and sorghum sourdoughs with defined strains, followed by propagation of doughs with a 10% inoculum and 12-h or 72-h fermentation cycles. Lineage I
L. reuteri
strains dominated sourdoughs propagated with 12-h fermentation cycles; lineage II
L. reuteri
strains dominated sourdoughs propagated with 72-h fermentation cycles.
L. reuteri
100-23Δ
gadB
was outcompeted by its wild-type strain in sourdoughs fermented with 72-h fermentation cycles;
L. reuteri
FUA3400Δ
gupCDE
was outcompeted by its wild-type strain in sourdoughs fermented with both 12-h and 72-h fermentation cycles. Competition experiments with isogenic pairs of strains resulted in a constant rate of strain displacement of the less competitive mutant strain. In conclusion, lineage-specific traits of
L. reuteri
determine the competitiveness of this species in sourdough fermentations.
The Underlying Structure of Adaptation under Strong Selection in 12 Experimental Yeast Populations
Authors: Kohn Linda M. , Anderson James B.
Published: July 2014

The aims of this study were to determine (i) whether adaptation under strong selection occurred through mutations in a narrow target of one or a few nucleotide sites or a broad target of numerous sites and (ii) whether the programs of adaptation previously observed from three experimental populations were unique or shared among populations that underwent parallel evolution. We used archived population samples from a previous study, representing 500 generations of experimental evolution in 12 populations under strong selection, 6 populations in a high-salt environment and 6 populations in a low-glucose environment. Each set of six populations included four with sexual reproduction and two with exclusively asexual reproduction. Populations were sampled as resequenced genomes of 115 individuals and as bulk samples from which frequencies of mutant alleles were estimated. In a high-salt environment, a broad target of 11 mutations within the proton exporter,
PMA1
, was observed among the six populations, in addition to expansions of the
ENA
gene cluster. This pattern was shared among populations that underwent parallel evolution. In a low-glucose environment, two programs of adaptation were observed. The originally observed pattern of mutation in
MDS3
/
MKT1
in population M8 was a narrow target of a single nucleotide, unique to this population. Among the other five populations, the three mutations were shared in a broad target, sensing/signaling genes
RAS1
and
RAS2. RAS1
/
RAS2
mutations were not observed in the high-salt populations;
PMA1
mutations were observed only in a high-salt environment.
Toxoplasma gondii Ingests and Digests Host Cytosolic Proteins
Authors: Dou Zhicheng , McGovern Olivia L. , Di Cristina Manlio , Carruthers Vern B.
Published: July 2014

The protozoan parasite
Toxoplasma gondii
resides within a nonfusogenic vacuole during intracellular replication. Although the limiting membrane of this vacuole provides a protective barrier to acidification and degradation by lysosomal hydrolases, it also physically segregates the parasite from the host cytosol. Accordingly, it has been suggested that
T. gondii
acquires material from the host via membrane channels or transporters. The ability of the parasite to internalize macromolecules via endocytosis during intracellular replication has not been tested. Here, we show that
Toxoplasma
ingests host cytosolic proteins and digests them using cathepsin L and other proteases within its endolysosomal system. Ingestion was reduced in mutant parasites lacking an intravacuolar network of tubular membranes, implicating this apparatus as a possible conduit for trafficking to the parasite. Genetic ablation of proteins involved in the pathway is associated with diminished parasite replication and virulence attenuation. We show that both virulent type I and avirulent type II strain parasites ingest and digest host-derived protein, indicating that the pathway is not restricted to highly virulent strains. The findings provide the first definitive evidence that
T. gondii
internalizes proteins from the host during intracellular residence and suggest that protein digestion within the endolysosomal system of the parasite contributes to toxoplasmosis.

IMPORTANCE
Toxoplasma gondii
causes significant disease in individuals with weak immune systems. Treatment options for this infection have drawbacks, creating a need to understand how this parasite survives within the cells it infects as a prelude to interrupting its survival strategies. This study reveals that
T. gondii
internalizes proteins from the cytoplasm of the cells it infects and degrades such proteins within a digestive compartment within the parasite. Disruption of proteins involved in the pathway reduced parasite replication and lessened disease severity. The identification of a novel parasite ingestion pathway opens opportunities to interfere with this process and improve the outcome of infection.
Apoptosis-Like Death, an Extreme SOS Response in Escherichia coli
Authors: Erental Ariel , Kalderon Ziva , Saada Ann , Smith Yoav , Engelberg-Kulka Hanna
Published: July 2014

In bacteria, SOS is a global response to DNA damage, mediated by the
recA-lexA
genes, resulting in cell cycle arrest, DNA repair, and mutagenesis. Previously, we reported that
Escherichia coli
responds to DNA damage via another
recA-lexA
-mediated pathway resulting in programmed cell death (PCD). We called it apoptosis-like death (ALD) because it is characterized by membrane depolarization and DNA fragmentation, which are hallmarks of eukaryotic mitochondrial apoptosis. Here, we show that ALD is an extreme SOS response that occurs only under conditions of severe DNA damage. Furthermore, we found that ALD is characterized by additional hallmarks of eukaryotic mitochondrial apoptosis, including (i) rRNA degradation by the endoribonuclease YbeY, (ii) upregulation of a unique set of genes that we called
e
xtensive-
d
amage-
i
n
duced (
Edin
) genes, (iii) a decrease in the activities of complexes I and II of the electron transport chain, and (iv) the formation of high levels of OH˙ through the Fenton reaction, eventually resulting in cell death. Our genetic and molecular studies on ALD provide additional insight for the evolution of mitochondria and the apoptotic pathway in eukaryotes.

IMPORTANCE
The SOS response is the first described and the most studied bacterial response to DNA damage. It is mediated by a set of two genes,
recA-lexA
, and it results in DNA repair and thereby in the survival of the bacterial culture. We have shown that
Escherichia coli
responds to DNA damage by an additional
recA-lexA
-mediated pathway resulting in an apoptosis-like death (ALD). Apoptosis is a mode of cell death that has previously been reported only in eukaryotes. We found that
E. coli
ALD is characterized by several hallmarks of eukaryotic mitochondrial apoptosis. Altogether, our results revealed that
recA-lexA
is a DNA damage response coordinator that permits two opposite responses: life, mediated by the SOS, and death, mediated by the ALD. The choice seems to be a function of the degree of DNA damage in the cell.
Coverage of common cancer types in UK national newspapers: a content analysis
Authors: Konfortion Julie , Jack Ruth H , Davies Elizabeth A
Published: July 2014

Objective

To determine whether recent newspaper coverage of the four most common cancer types relates to their relative burden and national awareness months, and to identify the subject focus during high-coverage periods.

Design

Content analysis using the Nexis newspaper article database.

Setting

UK 2011–2012.

Outcome measures

Annual number and ranking, monthly proportions and subject of articles on breast, lung, bowel and prostate cancers.

Results

9178 articles were identified during 2011 and 2012 featuring breast (4237), prostate (1757), lung (1746) and bowel (1438) cancer. Peaks in monthly proportions above the 99% upper confidence limit were identified for each. Breast cancer had the highest coverage of 12% and 17% during its awareness month. Smaller peaks (11%) were identified during Bowel Cancer Awareness month. Prostate cancer received high coverage in relation to the case of the man convicted of the Lockerbie bombing who had been diagnosed with the cancer, and lung cancer in relation to the deaths of celebrities. Breast cancer was covered most often overall and by newspaper category while the lower coverage of other cancer types did not consistently mirror the relative number of new cases each year. The peaks by newspaper category were similar to the overall coverage with few exceptions.

Conclusions

UK newspaper coverage of common cancer types other than of the breast appears under-represented relative to their population burden. Coverage of breast cancer and bowel cancer appears to be influenced by their awareness months, while that of prostate cancer and lung cancer is influenced by other media stories. Health-promoting public bodies and campaigners could learn from the success of Breast Cancer Awareness Month and work more closely with journalists to ensure that the relevant messages reach wider audiences.
Examining different measures of multimorbidity, using a large prospective cross-sectional study in Australian general practice
Authors: Harrison Christopher , Britt Helena , Miller Graeme , Henderson Joan
Published: July 2014

Objectives

Prevalence estimates of multimorbidity vary widely due to inconsistent definitions and measurement methods. This study examines the independent effects on prevalence estimates of how ‘disease entity’ is defined—as a single chronic condition or chapters/domains in the International Classification of Primary Care (V.2; ICPC-2), International Classification of Disease (10th revision; ICD-10) or the Cumulative Illness Rating Scale (CIRS), the number of disease entities required for multimorbidity, and the number of chronic conditions studied.

Design

National prospective cross-sectional study.

Setting

Australian general practice.

Participants

8707 random consenting deidentified patient encounters with 290 randomly selected general practitioners.

Main outcome measures

Prevalence estimates of multimorbidity using different definitions.

Results

Data classified to ICPC-2 chapters, ICD-10 chapters or CIRS domains produce similar multimorbidity prevalence estimates. When multimorbidity was defined as two or more (2+) disease entities: counting individual chronic conditions and groups of chronic conditions produced similar estimates; the 12 most prevalent chronic conditions identified about 80% of those identified using all chronic conditions. When multimorbidity was defined as 3+ disease entities: counting individual chronic conditions produced significantly higher estimates than counting groups of chronic conditions; the 12 most prevalent chronic conditions identified only two-thirds of patients identified using all chronic conditions.

Conclusions

Multimorbidity defined as 2+ disease entities can be measured using different definitions of disease entity with as few as 12 prevalent chronic conditions, but lacks specificity to be useful, especially in older people. Multimorbidity, defined as 3+, requires more measurement conformity and inclusion of all chronic conditions, but provides greater specificity than the 2+ definition. The proposed concept of “complex multimorbidity”, the co-occurrence of three or more chronic conditions affecting three or more different body systems within one person without defining an index chronic condition, may be useful in identifying high-need individuals.
Is the growth of the child of a smoking mother influenced by the father's prenatal exposure to tobacco? A hypothesis generating longitudinal study
Authors: Pembrey Marcus , Northstone Kate , Gregory Steven , Miller Laura L , Golding Jean
Published: July 2014

Objectives

Transgenerational effects of different environmental exposures are of major interest, with rodent experiments focusing on epigenetic mechanisms. Previously, we have shown that if the study mother is a non-smoker, there is increased mean birth weight, length and body mass index (BMI) in her sons if she herself had been exposed prenatally to her mother's smoking. The aim of this study was to determine whether the prenatal smoke exposure of either parent influenced the growth of the fetus of a smoking woman, and whether any effects were dependent on the fetal sex.

Design

Population-based prebirth cohort study.

Setting

Avon Longitudinal Study of Parents and Children.

Participants

Participants were residents of a geographic area with expected date of delivery between April 1991 and December 1992. Among pregnancies of mothers who smoked during pregnancy, data were available concerning maternal and paternal prenatal exposures to their own mother smoking for 3502 and 2354, respectively.

Primary and secondary outcome measures

Birth weight, length, BMI and head circumference.

Results

After controlling for confounders, there were no associations with birth weight, length or BMI. There was a strong adjusted association of birth head circumference among boys whose fathers had been exposed prenatally (mean difference −0.35 cm; 95% CI −0.57 to −0.14; p=0.001). There was no such association with girls (interaction p=0.006). Similar associations were found when primiparae and multiparae were analysed separately. In order to determine whether this was reflected in child development, we examined the relationships with IQ; we found that the boys born to exposed fathers had lower IQ scores on average, and that this was particularly due to the verbal component (mean difference in verbal IQ −3.65 points; 95% CI −6.60 to −0.70).

Conclusions

Head size differences concerning paternal fetal exposure to smoking were unexpected and, as such, should be regarded as hypothesis generating.
Observational longitudinal cohort study to determine progression to heart failure in a screened community population: the Echocardiographic Heart of England Screening Extension (ECHOES-X) study
Authors: Taylor Clare J , Roalfe Andrea K , Tait Lynda , Davis Russell C , Iles Rachel , Derit Marites , Hobbs F D Richard
Published: July 2014

Objectives

Rescreen a large community cohort to examine the progression to heart failure over time and the role of natriuretic peptide testing in screening.

Design

Observational longitudinal cohort study.

Setting

16 socioeconomically diverse practices in central England.

Participants

Participants from the original Echocardiographic Heart of England Screening (ECHOES) study were invited to attend for rescreening.

Outcome measures

Prevalence of heart failure at rescreening overall and for each original ECHOES subgroup. Test performance of N Terminal pro-B-type Natriuretic Peptide (NT-proBNP) levels at different thresholds for screening.

Results

1618 of 3408 participants underwent screening which represented 47% of survivors and 26% of the original ECHOES cohort. A total of 176 (11%, 95% CI 9.4% to 12.5%) participants were classified as having heart failure at rescreening; 103 had heart failure with reduced ejection fraction (HFREF) and 73 had heart failure with preserved ejection fraction (HFPEF). Sixty-eight out of 1232 (5.5%, 95% CI 4.3% to 6.9%) participants who were recruited from the general population over the age of 45 and did not have heart failure in the original study, had heart failure on rescreening. An NT-proBNP cut-off of 400 pg/mL had sensitivity for a diagnosis of heart failure of 79.5% (95% CI 72.4% to 85.5%) and specificity of 87% (95% CI 85.1% to 88.8%).

Conclusions

Rescreening identified new cases of HFREF and HFPEF. Progression to heart failure poses a significant threat over time. The natriuretic peptide cut-off level for ruling out heart failure must be low enough to ensure cases are not missed at screening.
Should both iodised and non-iodised salt be made available in Chinese cities? A cross-sectional survey
Authors: Yu J , Liu P , Liu Y , Liu S J , Sun D J
Published: July 2014

Objective

To contribute evidence relevant to the policy of supplying iodised salt (IS), non-iodised salt (NIS) or both in Chinese cities.

Design

Subnational telephone interview survey.

Setting

China.

Participants

Totally, 24 557 telephone numbers were dialled and 4833 citizens accepted the telephone interview. The telephone numbers were randomly selected by random digit dialling and a Mitofsky-Waksberg two-stage sampling method in 17 capital cities and 6 coastal cities from 17 iodine deficiency disorder (IDD)-eliminated provinces (municipalities).

Results

The 4833 citizens finished the telephone interview. Among them, 3738 (77.3%) citizens chose IS, 481 (10%) citizens chose NIS, and the others chose both IS and NIS. The citizens’ awareness rates of IDD and IDD preventive measures were 68.7% and 62.5%, respectively.

Conclusions

It is not a suitable time to supply IS and NIS simultaneously in the developed cities of China, but a pilot project may be conducted in the cities where IDD has been sustainably eliminated, there is strong awareness of IDD and the population can make informed decisions regarding IS. IDD health education should be further strengthened, especially regarding the potential for IQ damage.
Chronic condition comorbidity and multidrug therapy in general practice populations: a cross-sectional linkage study
Authors: Roberts Eyitope R , Green Daniel , Kadam Umesh T
Published: July 2014

Objectives

The study investigated (1) the association between comorbidity and multidrug prescribing compared with the index condition, and (2) the association between vascular comorbidity and non-vascular condition key drug prescribing.

Design

Cross-sectional study linking anonymised computer consultations with prescription records for a 2-year time period.

Setting

11 general practices in North Staffordshire, England.

Participants

Study groups aged 40 years and over (N=12 875). Within six conditions, comorbid group with the other five conditions was compared with an ‘alone’ group without them. Additionally, how the ‘vascular’ (one of diabetes, cardiovascular disease and cerebrovascular disease) comorbidity influenced chronic obstructive pulmonary disease (COPD), osteoarthritis (OA) or depression drug prescribing was investigated.

Outcome measures

Based on the British National Formulary, five main drug chapters constituted a measure of drug counts, with low count as 2 or less and high multidrug count as 3 or more. Key drugs prescribed for COPD, OA and depression were derived from guidelines.

Results

The adjusted associations between the comorbid groups and higher multidrug count compared with their respective ‘alone’ group were: odds ratio (OR) 7.1 (95% CI 5.6 to 9.0) for depression, OR 5.4 (95% CI 4.6 to 6.3) for cardiovascular disease, OR 3.7 (95% CI 2.8 to 5.0) for cerebrovascular disease, OR 3.6 (95% CI 3.1 to 4.3) for OA, OR 3.5 (95% CI 3.0 to 4.2) for diabetes and OR 3.2 (95% CI 2.6 to 4.0) for COPD. In COPD, vascular comorbidity was associated with a significant reduction in key COPD drug treatments (adjusted OR 0.6 (95% CI 0.4 to 0.8). In depression, vascular comorbidity was associated with a reduction in key depression drug treatments (OR 0.6 (95% CI 0.4 to 0.7)).

Conclusions

Our findings show that multidrug prescribing for different body systems is higher with comorbidity and may be associated with lower likelihood of prescribing for specific conditions. Further research is required on whether multidrug prescribing influences the outcomes of care for chronic conditions.
Deafening silence? Time to reconsider whether organisations are silent or deaf when things go wrong
Authors: Jones Aled , Kelly Daniel
Published: July 2014

Several public inquiries into healthcare failings in the UK have noted that employees of failing organizations attempt to raise concerns about shortcomings in care, often over a prolonged period of time, only for those concerns to be ignored. However, healthcare literature has largely focused on how organizations and their employees are silent in the face of such failings, positioning employees as daring not to speak in response to serious workplace problems or issues. We argue that only focussing on organizational silence is a critical mistake which misrepresents actual events and overly-simplifies the complexities of workplace culture. The disregard shown by academics, practitioners and policy makers to employee voice strategies, which do not amount to whistle-blowing, but equally cannot either be defined as “silence”, results in signals being ignored that can be effective in preventing and ending wrongdoing by others. In addition to understanding silence we suggest therefore that better understanding of why organizations are deaf to, or disregard, employee concerns are needed. We propose that a virtuous cycle is possible, whereby the introduction of systems that result in better listening and valuing of employee concerns reinforces a culture of speaking up and, in turn, organizational learning. Similarly, organizations that disregard employees concerns are destined not to learn, ultimately falling silent and failing.
Ultrasound-guided hematoma block in distal radial fracture reduction: a randomised clinical trial
Authors: Fathi Marzieh , Moezzi Meysam , Abbasi Saeed , Farsi Davood , Zare Mohammad Amin , Hafezimoghadam Peyman
Published: July 2014

Objective

We compared the efficacy and safety of ultrasound-guided haematoma block with that of procedural sedation and analgesia in patients with acute distal radial fracture reduction pain control.

Methods

This was a randomised clinical trial on adult patients conducted in two teaching hospitals. Patients received intravenous midazolam plus fentanyl in the procedural sedation and analgesia group, and fracture site injection of lidocaine 10% in the ultrasound guided haematoma block group. We measured pain scores before reduction, during reduction and 5, 10 and 15 min after reduction by a numeric rating scale, and patient and physician satisfaction by a four-level Likert scale. Time to discharge, early adverse effects and late complications were also compared.

Results

We enrolled 160 patients with distal radial fracture and randomised 143 patients into two groups (after excluding 17 patients). Pain was effectively controlled in both groups. Pain scores had no statistically significant difference before and during reduction and 5 and 15 min after reduction in the procedural sedation and analgesia and ultrasound guided haematoma block groups. Patient and physician overall satisfaction were similar in the two groups. Time to discharge was significantly lower in the ultrasound guided haematoma block group. Four patients (5.5%) in the procedural sedation and analgesia group showed early adverse effects. No patient in either group showed any late complications.

Conclusions

Ultrasound guided haematoma block may be a safe and effective alternative to procedural sedation and analgesia.

Trial registration number

201112308104N5.
Gains of chromosomes 7 and 17 in tubulocystic carcinoma of kidney: two cases with fluorescence in situ hybridisation analysis
Authors: Chen Ni , Nie Ling , Gong Jing , Chen Xueqin , Xu Miao , Chen Min , Zhou Qiao
Published: July 2014

Tubulocystic carcinoma (TCC) is a very rare renal tumour with unique gross and microscopic features, alternatively considered as low-grade collecting duct carcinoma. Recent studies favoured distinction of TCC from collecting duct carcinoma, and some cases of TCC synchronously coexisting with other renal cell tumour subtypes were described. We report here two new cases of pure (case 1) or mixed (case 2) TCC with fluorescence in situ hybridisation (FISH) analysis, which showed gains of chromosomes 7 and 17 in the pure TCC of case 1, as well as in the TCC and the papillary renal cell carcinoma (PRCC) components in case 2. These data may further support the notion that TCC is more closely related to PRCC.
Heterotopic ossification: a systematic review
Authors: Edwards Dafydd S , Clasper J C
Published: July 2014

Heterotopic ossification (HO) is the formation of mature lamellar bone in extraskeletal soft tissues. It was first described 1000 years ago in the healing of fractures, and in relation to military wounds, texts from the American Civil War and World War I refer to HO specifically. It continues to cause problems to injured service personnel; the consequences of wound and soft tissue complications in traumatic amputations pose particular problems to rehabilitation and prosthetic use. While HO is seen in rare genetic conditions, it is most prevalent after joint replacement surgery and trauma. In the civilian setting HO has been commonly described in patients after traumatic brain injuries, spinal cord injuries and burns. Militarily, as a consequence of recent operations, and the characteristic injury of blast-related amputations, a renewed interest in HO has emerged due to an increased incidence seen in casualties. The heterogeneous nature of a blast related amputation makes it difficult for a single aetiological event to be identified, although it is now accepted that blast, amputation through the zone of injury, increased injury severity and associated brain injuries are significant risk factors in HO formation. The exact cellular event leading to HO has yet to be identified, and as a consequence its prevention is restricted to the use of anti-inflammatory medication and radiation, which is often contraindicated in the acute complex military casualty. A systematic review in PubMed and the Cochrane Database identified research articles related to HO to illustrate the military problem of HO and its management, current research concepts and experimental theories regarding HO. This also served as a gap analysis providing the researchers detail of any knowledge deficit in this field, in particular to the military aspects of HO; 637 out of 7891 articles initially identified that referenced HO were relevant to this review.