bluuebunny/crossref_metadata_2025 huggingface dataset:
Link between Culture Zeta Potential Homogeneity and Ebp in Enterococcus faecalis
Authors: Tariq Muhammad , Bruijs Chissa , Kok Jan , Krom Bastiaan P.
Published: January 2012

Enterococcus faecalis
, a commensal of the gastrointestinal tract and an opportunistic pathogen, has the ability to adhere to surfaces and form biofilms. It has been shown earlier that only 10 to 20% of an
E. faecalis
OG1RF culture expresses endocarditis- and biofilm-associated pili (Ebp), which are involved in biofilm formation. Another study revealed that
E. faecalis
clinical isolates, as well as OG1RF, are heterogeneous with respect to their apparent zeta potential, which was also correlated with increased ability to form biofilm. The aim of this study was to demonstrate that the heterogeneity in the presence of Ebp is correlated to that in apparent zeta potential. Heterogeneous cultures of OG1RF showed two distinct subpopulations with the most (−38 mV) and least (−26 mV) negative zeta potential. Deletion of EbpR, the activator of the
ebp
operon, or the structural genes
ebpABC
resulted in homogeneous culture with the most negative zeta potential. Conversely, overexpression of EbpR or the structural genes
ebpABC
resulted in homogeneous culture with the least negative zeta potential. The results show that
ebp
operon expression in
E. faecalis
, as measured by using P

ebp

-
gfp
promoter fusion, is the cause of heterogeneity in zeta potential and that pilus production causes the cells to behave as the least negative particle in an electric field.
Enhanced Staphylolytic Activity of the Staphylococcus aureus Bacteriophage vB_SauS-phiIPLA88 HydH5 Virion-Associated Peptidoglycan Hydrolase: Fusions, Deletions, and Synergy with LysH5
Authors: Rodríguez-Rubio Lorena , Martínez Beatriz , Rodríguez Ana , Donovan David M. , García Pilar
Published: January 2012

Virion-associated peptidoglycan hydrolases have potential as antimicrobial agents due to their ability to lyse Gram-positive bacteria on contact. In this work, our aim was to improve the lytic activity of HydH5, a virion-associated peptidoglycan hydrolase from the
Staphylococcus aureus
bacteriophage vB_SauS-phiIPLA88. Full-length HydH5 and two truncated derivatives containing only the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) domain exhibited high lytic activity against live
S. aureus
cells. In addition, three different fusion proteins were created between lysostaphin and HydH5, each of which showed higher staphylolytic activity than the parental enzyme or its deletion construct. Both parental and fusion proteins lysed
S. aureus
cells in zymograms and plate lysis and turbidity reduction assays. In plate lysis assays, HydH5 and its derivative fusions lysed bovine and human
S. aureus
strains, the methicillin-resistant
S. aureus
(MRSA) strain N315, and human
Staphylococcus epidermidis
strains. Several nonstaphylococcal bacteria were not affected. HydH5 and its derivative fusion proteins displayed antimicrobial synergy with the endolysin LysH5
in vitro
, suggesting that the two enzymes have distinct cut sites and, thus, may be more efficient in combination for the elimination of staphylococcal infections.
Cloning, Baeyer-Villiger Biooxidations, and Structures of the Camphor Pathway 2-Oxo-Δ
3
-4,5,5-Trimethylcyclopentenylacetyl-Coenzyme A Monooxygenase of Pseudomonas putida ATCC 17453
Authors: Leisch Hannes , Shi Rong , Grosse Stephan , Morley Krista , Bergeron Hélène , Cygler Miroslaw , Iwaki Hiroaki , Hasegawa Yoshie , Lau Peter C. K.
Published: January 2012

A dimeric Baeyer-Villiger monooxygenase (BVMO) catalyzing the lactonization of 2-oxo-Δ
3
-4,5,5-trimethylcyclopentenylacetyl-coenzyme A (CoA), a key intermediate in the metabolism of camphor by
Pseudomonas putida
ATCC 17453, had been initially characterized in 1983 by Ougham and coworkers (H. J. Ougham, D. G. Taylor, and P. W. Trudgill, J. Bacteriol. 153:140–152, 1983). Here we cloned and overexpressed the 2-oxo-Δ
3
-4,5,5-trimethylcyclopentenylacetyl-CoA monooxygenase (OTEMO) in
Escherichia coli
and determined its three-dimensional structure with bound flavin adenine dinucleotide (FAD) at a 1.95-Å resolution as well as with bound FAD and NADP
+
at a 2.0-Å resolution. OTEMO represents the first homodimeric type 1 BVMO structure bound to FAD/NADP
+
. A comparison of several crystal forms of OTEMO bound to FAD and NADP
+
revealed a conformational plasticity of several loop regions, some of which have been implicated in contributing to the substrate specificity profile of structurally related BVMOs. Substrate specificity studies confirmed that the 2-oxo-Δ
3
-4,5,5-trimethylcyclopentenylacetic acid coenzyme A ester is preferred over the free acid. However, the catalytic efficiency (
k
cat
/

K
m

) favors 2-
n
-hexyl cyclopentanone (4.3 × 10
5
M
−1
s
−1
) as a substrate, although its affinity (

K
m

= 32 μM) was lower than that of the CoA-activated substrate (

K
m

= 18 μM). In whole-cell biotransformation experiments, OTEMO showed a unique enantiocomplementarity to the action of the prototypical cyclohexanone monooxygenase (CHMO) and appeared to be particularly useful for the oxidation of 4-substituted cyclohexanones. Overall, this work extends our understanding of the molecular structure and mechanistic complexity of the type 1 family of BVMOs and expands the catalytic repertoire of one of its original members.
Increased Furan Tolerance in Escherichia coli Due to a Cryptic
ucpA
Gene
Authors: Wang Xuan , Miller Elliot N. , Yomano Lorraine P. , Shanmugam K. T. , Ingram Lonnie O.
Published: January 2012

Expression arrays were used to identify 4 putative oxidoreductases that were upregulated (>3-fold) by furfural (15 mM, 15 min). Plasmid expression of one (
ucpA
) increased furan tolerance in ethanologenic strain LY180 and wild-type strain W. Deleting
ucpA
decreased furfural tolerance. Although the mechanism remains unknown, the cryptic
ucpA
gene is now associated with a phenotype: furan resistance.
Genome-Based Reconstruction of the Protein Import Machinery in the Secondary Plastid of a Chlorarachniophyte Alga
Authors: Hirakawa Yoshihisa , Burki Fabien , Keeling Patrick J.
Published: January 2012

Most plastid proteins are encoded by their nuclear genomes and need to be targeted across multiple envelope membranes. In vascular plants, the translocons at the outer and inner envelope membranes of chloroplasts (TOC and TIC, respectively) facilitate transport across the two plastid membranes. In contrast, several algal groups harbor more complex plastids, the so-called secondary plastids, which are surrounded by three or four membranes, but the plastid protein import machinery (in particular, how proteins cross the membrane corresponding to the secondary endosymbiont plasma membrane) remains unexplored in many of these algae. To reconstruct the putative protein import machinery of a secondary plastid, we used the chlorarachniophyte alga
Bigelowiella natans
, whose plastid is bounded by four membranes and still possesses a relict nucleus of a green algal endosymbiont (the nucleomorph) in the intermembrane space. We identified nine homologs of plant-like TOC/TIC components in the recently sequenced
B. natans
nuclear genome, adding to the two that remain in the nucleomorph genome (
B. natans
TOC75 [BnTOC75] and BnTIC20). All of these proteins were predicted to be localized to the plastid and might function in the inner two membranes. We also show that the homologs of a protein, Der1, that is known to mediate transport across the second membrane in the several lineages with secondary plastids of red algal origin is not associated with plastid protein targeting in
B. natans
. How plastid proteins cross this membrane remains a mystery, but it is clear that the protein transport machinery of chlorarachniophyte plastids differs from that of red algal secondary plastids.
Insights into the Gene Expression Profile of Uncultivable Hemotrophic Mycoplasma suis during Acute Infection, Obtained Using Proteome Analysis
Authors: Felder Kathrin M. , Carranza Paula M. , Gehrig Peter M. , Roschitzki Bernd , Barkow-Oesterreicher Simon , Hoelzle Katharina , Riedel Katharina , Kube Michael , Hoelzle Ludwig E.
Published: January 2012

Hemotrophic mycoplasmas, bacteria without cell walls whose niche is the erythrocytes of their hosts, have never been cultivatedin vitro. Therefore, knowledge of their pathogenesis is fundamental.Mycoplasma suisinfects pigs, causing either acute fatal hemolytic anemia or chronic low-grade anemia, growth retardation, and immune suppression. Recently, the complete genomes of two hemotrophic mycoplasma species,M. suisandM. haemofelis, were sequenced, offering new strategies for the analysis of their pathogenesis. In this study we implemented a proteomic approach to identifyM. suisproteins during acute infection by using tandem mass spectrometry. Twenty-two percent of the predicted proteins encoded inM. suisstrain KI_3806 were identified. These included nearly all encoded proteins of glycolysis and nucleotide metabolism. The proteins for lipid metabolism, however, were underrepresented. A high proportion of the detected proteins are involved in information storage and processing (72.6%). In addition, several proteins of different functionalities, i.e., posttranslational modification, membrane genesis, signal transduction, intracellular trafficking, inorganic ion transport, and defense mechanisms, were identified. In its reduced genome,M. suisharbors 65.3% (strain Illinois) and 65.9% (strain KI_3806) of the genes encode hypothetical proteins. Of these, only 6.3% were identified at the proteome level. All proteins identified in this study are present in bothM. suisstrains and are encoded in more highly conserved regions of the genome sequence. In conclusion, our proteome approach is a further step toward the elucidation of the pathogenesis and life cycle ofM. suisas well as the establishment of anin vitrocultivation system.
Perturbation of the Oxidizing Environment of the Periplasm Stimulates the PhoQ/PhoP System in Escherichia coli
Authors: Lippa Andrew M. , Goulian Mark
Published: January 2012

The PhoQ/PhoP two-component system is repressed by divalent cations, such as Mg
2+
and Ca
2+
, in the growth medium and stimulated by low pH and certain cationic antimicrobial peptides. In
Escherichia coli
, it was recently shown that the histidine kinase PhoQ is also modulated by at least two additional factors, the small membrane proteins SafA and MgrB. This raises the possibility that the PhoQ/PhoP circuit has additional regulatory components and integrates additional input signals. We screened
E. coli
transposon insertion mutants to look for proteins that modulate the activity of the PhoQ/PhoP system, and we uncovered a role for DsbA, a periplasmic oxidant that facilitates the formation of disulfide bonds. Deletion of
dsbA
or
dsbB
, which maintains a pool of oxidized DsbA, leads to increased transcription of at least two PhoP-regulated genes. Addition of the reducing agent dithiothreitol to wild-type cells had a similar effect, and treatment of a
dsbA
null strain with the oxidant Cu
2+
rescued the reporter gene expression phenotype. We also demonstrated that expression of an MgrB mutant that lacked cysteines blocked the effect of a
dsbA
null mutation on PhoQ/PhoP activity, suggesting that MgrB acts downstream of DsbA in this pathway. Taken together, these results demonstrate that a decrease in the oxidizing activity of the periplasm stimulates PhoQ/PhoP and may reveal a new input stimulus for this important two-component system.
Francisella tularensis RipA Protein Topology and Identification of Functional Domains
Authors: Mortensen Brittany L. , Fuller James R. , Taft-Benz Sharon , Collins Edward J. , Kawula Thomas H.
Published: January 2012

Francisella tularensis
is a Gram-negative coccobacillus and is the etiological agent of the disease tularemia. Expression of the cytoplasmic membrane protein RipA is required for
Francisella
replication within macrophages and other cell types; however, the function of this protein remains unknown. RipA is conserved among all sequenced
Francisella
species, and RipA-like proteins are present in a number of individual strains of a wide variety of species scattered throughout the prokaryotic kingdom. Cross-linking studies revealed that RipA forms homoligomers. Using a panel of RipA-green fluorescent protein and RipA-PhoA fusion constructs, we determined that RipA has a unique topology within the cytoplasmic membrane, with the N and C termini in the cytoplasm and periplasm, respectively. RipA has two significant cytoplasmic domains, one composed roughly of amino acids 1 to 50 and the second flanked by the second and third transmembrane domains and comprising amino acids 104 to 152. RipA functional domains were identified by measuring the effects of deletion mutations, amino acid substitution mutations, and spontaneously arising intragenic suppressor mutations on intracellular replication, induction of interleukin-1β (IL-1β) secretion by infected macrophages, and oligomer formation. Results from these experiments demonstrated that each of the cytoplasmic domains and specific amino acids within these domains are required for RipA function.
OnpA, an Unusual Flavin-Dependent Monooxygenase Containing a Cytochrome
b
5
Domain
Authors: Xiao Yi , Liu Ting-Ting , Dai Hui , Zhang Jun-Jie , Liu Hong , Tang Huiru , Leak David J. , Zhou Ning-Yi
Published: January 2012

ortho
-Nitrophenol 2-monooxygenase (EC 1.14.13.31) from
Alcaligenes
sp. strain NyZ215 catalyzes monooxygenation of
ortho
-nitrophenol to form catechol via
ortho
-benzoquinone. Sequence analysis of this
onpA
-encoded enzyme revealed that it contained a flavin-binding monooxygenase domain and a heme-binding cytochrome
b
5
domain. OnpA was purified to homogeneity as a His-tagged protein and was considered a monomer, as determined by gel filtration. FAD and heme were identified by high-performance liquid chromatography (HPLC) and HPLC-mass spectrometry (HPLC-MS) as cofactors in this enzyme, and quantitative analysis indicated that 1 mol of the purified recombinant OnpA contained 0.66 mol of FAD and 0.20 mol of heme. However, the enzyme activity of OnpA was increased by 60% and 450% after addition of FAD and hemin, respectively, suggesting that the optimal stoichiometry was 1:1:1. In addition, site-directed mutagenesis experiments confirmed that two highly conserved histidines located in the cytochrome
b
5
domain were associated with binding of the heme, and the cytochrome
b
5
domain was involved in the OnpA activity. These results indicate that OnpA is an unusual FAD-dependent monooxygenase containing a fused cytochrome
b
5
domain that is essential for its activity. Therefore, we here demonstrate a link between cytochrome
b
5
and flavin-dependent monooxygenases.
Expression of Multidrug Resistance Efflux Pump Gene
norA
Is Iron Responsive in Staphylococcus aureus
Authors: Deng Xin , Sun Fei , Ji Quanjiang , Liang Haihua , Missiakas Dominique , Lan Lefu , He Chuan
Published: January 2012

Staphylococcus aureus
utilizes efflux transporter NorA to pump out a wide range of structurally dissimilar drugs, conferring low-level multidrug resistance. The regulation of
norA
expression has yet to be fully understood although past studies have revealed that this gene is under the control of the global transcriptional regulator MgrA and the two-component system ArlRS. To identify additional regulators of
norA
, we screened a transposon library in strain Newman expressing the transcriptional fusion
norA-lacZ
for altered β-galactosidase activity. We identify a transposon insertion in
fhuB
, a gene that encodes a ferric hydroxamate uptake system permease, and propose that the
norA
transcription is iron responsive. In agreement with this observation, addition of FeCl
3
repressed the induction of
norA-lacZ
, suggesting that bacterial iron uptake plays an important role in regulating
norA
transcription. In addition, a
fur
(ferric uptake regulator) deletion exhibited compromised
norA
transcription and reduced resistance to quinolone compared to the wild-type strain, indicating that
fur
functions as a positive regulator of
norA
. A putative Fur box identified in the promoter region of
norA
was confirmed by electrophoretic mobility shift and DNase I footprint assays. Finally, by employing a siderophore secretion assay, we reveal that NorA may contribute to the export of siderophores. Collectively, our experiments uncover some novel interactions between cellular iron level and
norA
regulation in
S. aureus
.
Group X Aldehyde Dehydrogenases of Pseudomonas aeruginosa PAO1 Degrade Hydrazones
Authors: Taniyama Kosuke , Itoh Hideomi , Takuwa Atsushi , Sasaki Yasuyuki , Yajima Shunsuke , Toyofuku Masanori , Nomura Nobuhiko , Takaya Naoki
Published: January 2012

Hydrazones are natural and synthetic compounds containing a C=N-N moiety. Here we found that the opportunistic pathogen
Pseudomonas aeruginosa
PAO1 produced NAD
+
- or NADP
+
-dependent hydrazone dehydrogenase (HDH), which converts hydrazones to the corresponding hydrazides and acids rather than to the simple hydrolytic product aldehydes. Gene cloning indicated that the HDH is part of the group X aldehyde dehydrogenase (ALDH) family, which is distributed among bacteria, although the physiological roles of the ALDH family remain unknown. The PAO1 strain upregulated HDH in the presence of the hydrazone adipic acid bis(ethylidene hydrazide) (AEH). Gene disruption of the HDH-encoding
hdhA
(PA4022) decreased growth rates in culture medium containing AEH as the sole carbon source, and this effect was more obvious in the double gene disruption of
hdhA
and its orthologous
exaC
(PA1984), indicating that these genes are responsible for hydrazone utilization. Recombinant proteins of group X ALDHs from
Escherichia coli
,
Paracoccus denitrificans
, and
Ochrobactrum anthropi
also acted as HDHs in that they produced HDH activity in the cells and degraded hydrazones. These findings indicated the physiological roles of group X ALDHs in bacteria and showed that they comprise a distinct ALDH subfamily.
Dynamics ofspeBmRNA Transcripts in Streptococcus pyogenes
Authors: Chen Zhiyun , Itzek Andreas , Malke Horst , Ferretti Joseph J. , Kreth Jens
Published: January 2012

Streptococcus pyogenes(group A streptococcus [GAS]) is a human-specific pathogen that causes a variety of diseases ranging from superficial infections to life-threatening diseases. SpeB, a potent extracellular cysteine proteinase, plays an important role in the pathogenesis of GAS infections. Previous studies show that SpeB expression and activity are controlled at the transcriptional and posttranslational levels, though it had been unclear whetherspeBwas also regulated at the posttranscriptional level. In this study, we examined the growth phase-dependentspeBmRNA level and decay using quantitative reverse transcription-PCR (qRT-PCR) and Northern blot analyses. We observed thatspeBmRNA accumulated rapidly during exponential growth, which occurred concomitantly with an increase inspeBmRNA stability. A closer observation revealed that the increasedspeBmRNA stability was mainly due to progressive acidification. Inactivation of RNase Y, a recently identified endoribonuclease, revealed a role in processing and degradation ofspeBmRNA. We conclude that the increasedspeBmRNA stability contributes to the rapid accumulation ofspeBtranscript during growth.
CarF Mediates Signaling by Singlet Oxygen, Generated via Photoexcited Protoporphyrin IX, in Myxococcus xanthus Light-Induced Carotenogenesis
Authors: Galbis-Martínez Marisa , Padmanabhan S. , Murillo Francisco J. , Elías-Arnanz Montserrat
Published: January 2012

Blue light triggers carotenogenesis in the nonphototrophic bacterium
Myxococcus xanthus
by inducing inactivation of an anti-σ factor, CarR, and the consequent liberation of the cognate extracytoplasmic function (ECF) σ factor, CarQ. CarF, the protein implicated earliest in the response to light, does not resemble any known photoreceptor. It interacts physically with CarR and is required for its light-driven inactivation, but the mechanism is unknown. Blue-light sensing in
M. xanthus
has been attributed to the heme precursor protoporphyrin IX (PPIX), which can generate the highly reactive singlet oxygen species (
1
O
2
) by energy transfer to oxygen. However,
1
O
2
involvement in
M. xanthus
light-induced carotenogenesis remains to be established. Here, we present genetic evidence of the involvement of PPIX as well as
1
O
2
in light-induced carotenogenesis in
M. xanthus
and of how these are linked to CarF in the signal transduction pathway. Response to light was examined in
carF
-bearing and
carF-
deficient
M. xanthus
strains lacking endogenous PPIX due to deletion of
hemB
or accumulating PPIX due to deletion of
hemH
(
hemB
and
hemH
are early- and late-acting heme biosynthesis genes, respectively). This demonstrated that light induction of the CarQ-dependent promoter, P
QRS
, correlated directly with cellular PPIX levels. Furthermore, we show that P
QRS
activation is triggered by
1
O
2
and is inhibited by exogenously supplied hemin and that CarF is essential for the action of
1
O
2
. Thus, our findings indicate that blue light interaction with PPIX generates
1
O
2
, which must be transmitted via CarF to trigger the transcriptional response underlying light-induced carotenogenesis in
M. xanthus
.
Suppression of a
dnaKJ
Deletion by Multicopy
dksA
Results from Non-Feedback-Regulated Transcripts That Originate Upstream of the Major
dksA
Promoter
Authors: Chandrangsu Pete , Wang Li , Choi Sang Ho , Gourse Richard L.
Published: January 2012

DksA is an RNA polymerase (RNAP) binding transcription factor that controls expression of a large number of genes in concert with the small-molecule “alarmone” ppGpp. DksA also aids in the resolution of conflicts between RNAP and DNA polymerase (DNAP) during genome replication. DksA was originally identified as a multicopy suppressor of the temperature sensitivity caused by deletion of the genes coding for the DnaKJ chaperone system. Here, we address a longstanding question regarding the role of DksA in Δ
dnaKJ
suppression. We demonstrate that DksA expression from a multicopy plasmid is necessary and sufficient for suppression, that overexpression occurs despite the fact that the major
dksA
promoter is feedback regulated in wild-type cells, and that weak, non-feedback-regulated transcription originating upstream of the major promoter for the
dksA
gene accounts for overexpression. We tentatively rule out three potential explanations for suppression related to known functions of DnaKJ. Because a determinant in DksA needed for the regulation of transcription initiation, but not for resolution of RNAP-DNAP conflicts, is needed to bypass the need for DnaKJ, we suggest that suppression results from an unidentified product whose promoter is directly or indirectly regulated by DksA.
Bacillus subtilis RapA Phosphatase Domain Interaction with Its Substrate, Phosphorylated Spo0F, and Its Inhibitor, the PhrA Peptide
Authors: Diaz Alejandra R. , Core Leighton J. , Jiang Min , Morelli Michela , Chiang Christina H. , Szurmant Hendrik , Perego Marta
Published: January 2012

Rap proteins in
Bacillus subtilis
regulate the phosphorylation level or the DNA-binding activity of response regulators such as Spo0F, involved in sporulation initiation, or ComA, regulating competence development. Rap proteins can be inhibited by specific peptides generated by the export-import processing pathway of the Phr proteins. Rap proteins have a modular organization comprising an amino-terminal alpha-helical domain connected to a domain formed by six tetratricopeptide repeats (TPR). In this study, the molecular basis for the specificity of the RapA phosphatase for its substrate, phosphorylated Spo0F (Spo0F∼P), and its inhibitor pentapeptide, PhrA, was analyzed in part by generating chimeric proteins with RapC, which targets the DNA-binding domain of ComA, rather than Spo0F∼P, and is inhibited by the PhrC pentapeptide.
In vivo
analysis of sporulation efficiency or competence-induced gene expression, as well as
in vitro
biochemical assays, allowed the identification of the amino-terminal 60 amino acids as sufficient to determine Rap specificity for its substrate and the central TPR3 to TPR5 (TPR3-5) repeats as providing binding specificity toward the Phr peptide inhibitor. The results allowed the prediction and testing of key residues in RapA that are essential for PhrA binding and specificity, thus demonstrating how the widespread structural fold of the TPR is highly versatile, using a common interaction mechanism for a variety of functions in eukaryotic and prokaryotic organisms.
How, where and with whom? Physical activity context preferences of three adult groups at risk of inactivity
Authors: Burton Nicola W , Khan Asaduzzaman , Brown Wendy J
Published: January 2012

Background

Strategies to promote physical activity may be more successful if they reflect people's interests.

Purpose

To explore physical activity contexts preferred by three adult groups at risk of inactivity: older adults, those with low income and those with high body mass index (BMI).

Methods

Cross-sectional data were from a mail survey of 7873 adults aged 42–67 years. Respondents indicated the extent of disagreement or agreement with a preference for each of 14 contexts relating to format (eg, vigorous), location (eg, outdoors) and social setting (eg, done alone). Data were analysed using multilevel multinomial logistic regression. Adjusted OR and 95% CI are reported.

Results

Those aged 60–67 (vs 42–49) years had significantly higher odds to prefer activities with people of same age, and significantly lower odds to prefer activities that are at a fixed time with scheduled sessions, competitive, team-based or vigorous. Adults with low (vs high) income had significantly higher odds to prefer activities that are low cost, not just about exercise, team-based, supervised, skill-based or that can be done alone, and significantly lower odds to prefer vigorous or outdoor activities. Adults with BMI 30+ (vs<25) had significantly higher odds to prefer activities that are supervised, with people the same sex, team-based, with people the same age, or at a fixed time with scheduled sessions.

Conclusions

These three groups had distinct preferences for how, where and with whom the physical activity is done. This information could be used by those who promote, design, deliver and evaluate physical activity opportunities.
Functional management of ankle sprains: what volume and intensity of walking is undertaken in the first week postinjury
Authors: Tully Mark A , Bleakley Chris M , O'Connor Sean R , McDonough Suzanne M
Published: January 2012

Background

Acute ankle sprains are usually managed functionally, with advice to undertake progressive weight-bearing and walking. Mechanical loading is an important modular of tissue repair; therefore, the clinical effectiveness of walking after ankle sprain may be dose dependent. The intensity, magnitude and duration of load associated with current functional treatments for ankle sprain are unclear.

Aim

To describe physical activity (PA) in the first week after ankle sprain and to compare results with a healthy control group.

Methods

Participants (16–65 years) with an acute ankle sprain were randomised into two groups (standard or exercise). Both groups were advised to apply ice and compression, and walk within the limits of pain. The exercise group undertook additional therapeutic exercises. PA was measured using an activPAL accelerometer, worn for 7 days after injury. Comparisons were made with a non-injured control group.

Results

The standard group were significantly less active (1.2±0.4 h activity/day; 5621±2294 steps/day) than the exercise (1.7±0.7 h/day, p=0.04; 7886±3075 steps/day, p=0.03) and non-injured control groups (1.7±0.4 h/day, p=0.02; 8844±2185 steps/day, p=0.002). Also, compared with the non-injured control group, the standard and exercise groups spent less time in moderate (38.3±12.7 min/day vs 14.5±11.4 min/day, p=0.001 and 22.5±15.9 min/day, p=0.003) and high-intensity activity (4.1±6.9 min/day vs 0.1±0.1 min/day, p=0.001 and 0.62±1.0 min/day p=0.005).

Conclusion

PA patterns are reduced in the first week after ankle sprain, which is partly ameliorated with addition of therapeutic exercises. This study represents the first step towards developing evidence-based walking prescription after acute ankle sprain.
Winter sports athletes: long-term effects of cold air exposure
Authors: Sue-Chu Malcolm
Published: January 2012

Athletes such as skaters and skiers inhale large volumes of cold air during exercise and shift from nasal to mouth breathing. Endurance athletes, like cross-country skiers, perform at 80% or more of their maximal oxygen consumption and have minute ventilations in excess of 100 l/min. Cold air is always dry, and endurance exercise results in loss of water and heat from the lower respiratory tract. In addition, athletes can be exposed to indoor and outdoor pollutants during the competitive season and during all-year training. Hyperpnoea with cold dry air represents a significant environmental stress to the airways. Winter athletes have a high prevalence of respiratory symptoms and airway hyper-responsiveness to methacholine and hyperpnoea. The acute effects of exercise in cold air are neutrophil influx as demonstrated in lavage fluid and airway epithelial damage as demonstrated by bronchoscopy. Upregulation of pro-inflammatory cytokines has been observed in horses. Chronic endurance training damages the epithelium of the small airways in mice. Airway inflammation has been observed on bronchoscopy of cross-country skiers and in dogs after a 1100-mile endurance race in Alaska. Neutrophilic and lymphocytic inflammation with remodelling is present in bronchial biopsies from skiers. Repeated peripheral airway hyperpnoea with dry air causes inflammation and remodelling in dogs. As it is currently unknown if these airway changes are reversible upon cessation of exposure, preventive measures to diminish exposure of the lower airways to cold air should be instituted by all winter sports athletes.
Respiratory physiology: adaptations to high-level exercise
Authors: McKenzie Donald C
Published: January 2012

Most exercise scientists would agree that the physiological determinants of peak endurance performance include the capacity to transport oxygen to the working muscle, diffusion from the muscle to the mitochondria, energy production and force generation, all influenced by signals from the central nervous system. In general, the capacity of the pulmonary system far exceeds the demands required for ventilation and gas exchange during exercise. Endurance training induces large and significant adaptations within the cardiovascular, musculoskeletal and haematological systems. However, the structural and functional properties of the lung and airways do not change in response to repetitive physical activity and, in elite athletes, the pulmonary system may become a limiting factor to exercise at sea level and altitude. As a consequence to this respiratory paradox, highly trained athletes may develop intrathoracic and extrathoracic obstruction, expiratory flow limitation, respiratory muscle fatigue and exercise-induced hypoxaemia. All of these maladaptations may influence performance.
Effects of resistance training on arterial stiffness: a meta-analysis
Authors: Miyachi Motohiko
Published: January 2012

Background

Regular aerobic exercise prevents and reverses arterial stiffening, but the association between resistance training and arterial stiffness is unclear.

Aim

This study was performed to conduct a systematic review and meta-analysis of randomised controlled clinical trials (RCTs) assessing the associations between resistance training and changes in arterial stiffness.

Methods

MEDLINE and SPORTDiscus databases were searched from January 1980 through to April 2011. RCTs evaluating the ability of resistance training to increase arterial stiffness in comparison with a control group were included in the meta-analysis. Two independent reviewers extracted data and assessed the quality of the included studies. Data from 185 reports of eight RCTs (193 participants) were included. Pooled mean differences in arterial stiffness indices (carotid arterial β stiffness and pulse wave velocity (PWV)) between intervention and control groups were calculated using a random-effects model.

Results

The overall association of resistance training versus control with relative changes in carotid β index or PWV (eight studies; 193 participants) was 10.7% (95% CI 3.4% to 18.0%; I2, 89%; heterogeneity, p<0.001). Five studies indicated that resistance training in young subjects (n=115) was significantly associated with an increase in stiffness index of 14.3% (95% CI 8.5% to 20.1%; I2, 71%; heterogeneity, p<0.001) compared with controls. However, three studies showed that resistance training in middle-aged subjects (n=78) was not associated with changes in arterial stiffness. In addition, although high-intensity resistance training (n=87) was significantly associated with an increase in stiffness of 11.6%, moderate-intensity resistance training (n=106) showed no such association.

Conclusion

High-intensity resistance training is associated with increased arterial stiffness in young subjects with low baseline levels of arterial stiffness.
The incidence of admissions for schizophrenia and related psychoses in two cohorts: 1875–1924 and 1994–2010
Authors: Healy David , Le Noury Joanna , Linden Stefanie Caroline , Harris Margaret , Whitaker Chris , Linden David , Baker Darren , Roberts Anthony P
Published: January 2012

Objective

To investigate changes in incidence of admissions for schizophrenia and related non-affective psychoses in North Wales.

Design

Data from two epidemiologically complete cohorts of patients presenting for the first time to mental health services in North Wales between 1875–1924 and 1994–2010 are used in this study to map the incidence of hospital admissions for schizophrenia and non-affective psychoses.

Setting

The North Wales Asylum Denbigh (archived patient case notes) and the North West Wales District General Hospital psychiatric unit.

Population

3168 patients admitted to the North Wales Asylum Denbigh between 1875 and 1924 and 355 patients admitted to the District General Hospital psychiatric unit between 1994 and 2010.

Results

There was an increasing admission incidence for schizophrenia between 1875 and 1900, a higher admission rate in the 1990s for men, followed by a drop in rates of admission for both genders since 2006. Admission incidences switch from parity between the sexes in the historical period to a doubling of the admission rates for men compared with women in the modern period. This admission pattern differs from the admission patterns for affective psychoses or organic disorders.

Conclusion

There have been changes in the incidence of admissions for schizophrenia in North Wales.
Healthcare use and costs associated with obesity in Badalona, Spain: a study protocol: Table 1
Authors: Sicras-Mainar Antonio , Gil Joan , Mora Toni , Navarro-Artieda Ruth , Ayma Joan
Published: January 2012

Introduction

The objectives of the study are twofold. First, to calculate healthcare resource utilisation and costs for a cohort of adult overweight and obese patients observed in primary and hospital care centres during eight consecutive years (2003–2010) in an urban setting in Spain. An analysis of whether these costs vary by groups of individuals and types of disease, and of how they compare with the previous literature, is carried out in order to predict actions or policies for resource optimisation. The second objective is to estimate the impact of overweight and obesity on the consumption of resources and costs, accounting for a wide array of controls.

Methods and analysis

Observational and retrospective cohort data are used, consisting of medical records of patients followed up in outpatient and hospital care facilities during the years 2003–2010. Three cohorts of patients are analysed: normal weight (18.5≥ body mass index (BMI) <25), overweight (25≥ BMI <30) and obese (BMI ≥30); BMI is computed using clinical information. Individual-level data on comorbidity, resource utilisation and costs are available, and external information provided by the population census regarding socioeconomic status is used. Utilisation and associated costs across BMI groups are compared by computing ratios for overweight and obese individuals relative to those of normal weight. Count data regression models (hurdle and finite mixture models) are used, together with two-part model regression models and taking into account the panel structure of the data set to explore the impact of overweight and obesity on the increased utilisation of health services and costs, accounting for a wide set of controls.
Late presentations of minor head injury
Authors: Barrow Anna , Ndikum John , Harris Tim
Published: January 2012

Objective

To determine the frequency with which a CT head is performed in patients presenting more than 4 h after minor head injury and the clinical features that predict an abnormal scan.

Design

Observational cohort study.

Setting

Emergency department (ED) of the Royal London Hospital, London, UK.

Participants

500 patients presenting to the ED of the Royal London Hospital.

Methods

Chart review of all patients with minor head injury presenting more than 4 h from insult to the ED between December 2007 and May 2009. Inclusion criteria were: age over 16 years, Glasgow coma scale (GCS) 14 or 15 on first assessment, over 4 h post-injury. Exclusion criteria were: age under 16 years, GCS 13 and less, injuries limited to the face with no risk of intracranial injury; presentation less than 4 h after injury.

Results

497 patients were identified: 147 patients had CT head; 11 had intracranial injuries on CT. Loss of consciousness (p=0.0005), potential coagulopathy (p=0.0015), injuries above the clavicles (p=0.0150), open/depressed skull fracture (p=0.0221), alcohol/drug intoxication (p=0.0406) and focal neurology (p=0.0562) were predictors of positive CT scan. Five patients (1% of sample, 45% of patients with abnormal CT) required a neurosurgical procedure. Two (18.2%) self-discharged and four (36.4%) were followed up as outpatients. One patient (0.09%) died as a result of intracranial injury.

Discussion

Patients with minor head injury who present over 4 h post-insult exhibit a similar risk of intracranial pathology to those presenting within 4 h. The risk factors previously identified to predict intracranial injury are similar in this study.
The role of prenatal, perinatal and postnatal factors in the explanation of socioeconomic inequalities in preschool asthma symptoms: the Generation R Study
Authors: Hafkamp-de Groen Esther , van Rossem Lenie , de Jongste Johan C , Mohangoo Ashna D , Moll Henriëtte A , Jaddoe Vincent W V , Hofman Albert , Mackenbach Johan P , Raat Hein
Published: January 2012

Background

The authors assessed whether socioeconomic inequalities in asthma symptoms were already present in preschool children and to what extent prenatal, perinatal and postnatal risk factors for asthma symptoms mediate the effect of socioeconomic status (SES).

Methods

The study included 3136 Dutch children participating in the Generation R Study, a prospective cohort study. Adjusted ORs of asthma symptoms for low and middle SES (household income and maternal education) compared to high SES were calculated after adjustment for potential confounders and also adjusted for prenatal, perinatal and postnatal mediators at preschool age.

Results

At age 1 year, low-SES children had a 40% lower risk of asthma symptoms compared to high-SES children (p<0.01). However, the risk of asthma symptoms in 3- and 4-year-old low-SES children was 1.5 times higher compared to their high-SES age mates (p<0.05). The positive associations at age 1 year were particularly modified by postnatal factors (up to 38%). In toddlers, prenatal factors explained up to 58% of the negative associations between SES and asthma symptoms.

Conclusions

SES indirectly affects asthma symptoms at preschool age. The inverse association between SES and asthma symptoms emerges at age 3 years. This is particularly due to a high level of adverse prenatal circumstances in low-SES toddlers. Future research should evaluate public health programs (during pregnancy) to reduce socioeconomic inequalities in childhood asthma.
Socioeconomic inequalities and vaccination coverage: results of an immunisation coverage survey in 27 Brazilian capitals, 2007–2008
Authors: Barata Rita Barradas , Sampaio de Almeida Ribeiro Manoel Carlos , de Moraes José Cássio , Flannery Brendan ,   on behalf of the Vaccine Coverage Survey 2007 Group
Published: January 2012

Background

Since 1988, Brazil's Unified Health System has sought to provide universal and equal access to immunisations. Inequalities in immunisation may be examined by contrasting vaccination coverage among children in the highest versus the lowest socioeconomic strata. The authors examined coverage with routine infant immunisations from a survey of Brazilian children according to socioeconomic stratum of residence census tract.

Methods

The authors conducted a household cluster survey in census tracts systematically selected from five socioeconomic strata, according to average household income and head of household education, in 26 Brazilian capitals and the federal district. The authors calculated coverage with recommended vaccinations among children until 18 months of age, according to socioeconomic quintile of residence census tract, and examined factors associated with incomplete vaccination.

Results

Among 17 295 children with immunisation cards, 14 538 (82.6%) had received all recommended vaccinations by 18 months of age. Among children residing in census tracts in the highest socioeconomic stratum, 77.2% were completely immunised by 18 months of age versus 81.2%–86.2% of children residing in the four census tract quintiles with lower socioeconomic indicators (p<0.01). Census tracts in the highest socioeconomic quintile had significantly lower coverage for bacille Calmette-Guérin, oral polio and hepatitis B vaccines than those with lower socioeconomic indicators. In multivariable analysis, higher birth order and residing in the highest socioeconomic quintile were associated with incomplete vaccination. After adjusting for interaction between socioeconomic strata of residence census tract and household wealth index, only birth order remained significant.

Conclusions

Evidence from Brazilian capitals shows success in achieving high immunisation coverage among poorer children. Strategies are needed to reach children in wealthier areas.
A worksite vitality intervention to improve older workers' lifestyle and vitality-related outcomes: results of a randomised controlled trial
Authors: Strijk Jorien E , Proper Karin I , van der Beek Allard J , van Mechelen Willem
Published: January 2012

Objective

To evaluate the effectiveness of a worksite vitality intervention on vigorous physical activity (VPA), fruit intake, aerobic capacity, mental health and need for recovery after work among older hospital workers (ie, 45 years and older).

Methods

The 6-month intervention was evaluated using a randomised controlled trial design. Workers who were randomised to the intervention group (n=367; control: n=363) received the Vital@Work intervention containing (1) a Vitality Exercise Program (VEP) combined with (2) three visits to Personal Vitality Coach. The VEP consisted of a weekly yoga session, a weekly workout session and weekly unsupervised aerobic exercising. Free fruit was provided at the VEP. Data on the outcome measures were collected (ie, year 2009–2010) at baseline (n=730) and 6 months of follow-up after baseline (n=575) using questionnaires, accelerometers and 2 km walk tests. Effects were analysed according to the intention-to-treat principle with complete cases (n=575) and imputed data (n=730) using linear regression analyses. Additional analyses were performed for high yoga and workout compliance (ie, >mean number of sessions).

Results

Effects were found for sports activities (β=40.4 min/week, 95% CI 13.0 to 67.7) and fruit intake (β=2.7 pieces/week, 95% CI 0.07 to 4.7) and were stronger for workers with high compliance to yoga (sport: β=49.6 min/week, 95% CI 13.9 to 85.2; fruit: β=3.8 pieces/week, 95% CI 1.1 to 6.4) and workout sessions (sport: β=72.9 min/week, 95% CI 36.1 to 109.8; fruit: β=4.0 pieces/week, 95% CI 1.1 to 6.4). The intervention group lowered their need for recovery, when compared to controls (β=−3.5, 95% CI −6.4 to −0.54), with stronger effects for high workout compliance (β=−5.3, 95% CI −9.3 to −1.3). No effects were found on VPA, aerobic capacity or mental health.

Conclusions

Implementation of worksite yoga and workout facilities and minimal fruit interventions should be considered by employers to promote transitions into healthier lifestyles and thereby health.
Molecular epidemiology of genitalChlamydia trachomatisinfection in Shenzhen, China
Authors: Zhang Juan-Juan , Zhao Guang-Lu , Wang Feng , Hong Fu-Chang , Luo Zhen-Zhou , Lan Li-Na , Zhang Chun-Lai , Peng Yi , Liu Xiao-Li , Feng Tie-Jian , Chen Xiang-Sheng
Published: January 2012

Objective

To investigate molecular epidemiology ofChlamydia trachomatisinfection among patients recruited from different clinic settings in Shenzhen, China.

Methods

A total of 2534 patients from the sexually transmitted disease (STD) clinics, obstetrics and gynaecology (OBGYN) clinics and genitourinary medicine (GUM) clinics in 34 hospitals participated in the study. TheC trachomatisinfection was determined using COBAS Amplicor system. DNA extracted inC trachomatis-positive samples was amplified using a nested PCR based onompA gene and then genotyped using a microsphere suspension array.

Results

The overall prevalence of genitalC trachomatisinfection was 17.7%. The prevalence in patients at STD or GUM clinics was significantly higher than that in patients at OBGYN clinics. Being male (adjusted OR (AOR) 2.5, 95% CI 1.8 to 3.4), having no consistent use of a condom with casual partners in the past 3 months (AOR 1.7, 95% CI 1.1 to 2.8) and having any STD symptoms (AOR 3.3, 95% CI 2.0 to 5.4) were independently associated withC trachomatisinfection. Eight genotypes were identified. The most prevalent genotypes were F (22.3%), E (22.0%) and D/Da (12.7%). Other genotypes were G/Ga (8.0%), J (7.3%), K (2.7%), H (2.7%) and I/Ia (0.4%). Eighty-two samples (18.3%) were infected with multiple genotypes. Genotype D/Da among patients from GUM clinics was more common than those from STD or OBGYN clinics. Infections with genotypes G and F were statistically associated with abnormal vaginal discharge (p=0.001) and being married (p=0.014), respectively. Infection with multiple genotypes was more common among patients with a higher income (p=0.011).

Conclusion

A substantial prevalence of genitalC trachomatisinfection in Shenzhen suggests the importance of detection and treatment of the infection in high-risk groups.