bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Habitat and Climate Variables on Arbuscular Mycorrhizal Fungus Community Distribution, as Revealed by a Case Study of Facultative Plant Epiphytism under Semiarid Conditions
Authors: Torrecillas E. , Torres P. , Alguacil M. M. , Querejeta J. I. , Roldán A.
Published: September 2013

In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as
Phoenix dactylifera
L. (date palm). In this study, we focused on
Sonchus tenerrimus
L. plants growing as facultative epiphytes in
P. dactylifera
and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial
S. tenerrimus
plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum
Glomeromycota
, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats.
Noninvasive High-Throughput Single-Cell Analysis of the Intracellular pH of Saccharomyces cerevisiae by Ratiometric Flow Cytometry
Authors: Valkonen Mari , Mojzita Dominik , Penttilä Merja , Benčina Mojca
Published: September 2013

The ability of cells to maintain pH homeostasis in response to environmental changes has elicited interest in basic and applied research and has prompted the development of methods for intracellular pH measurements. Many traditional methods provide information at population level and thus the average values of the studied cell physiological phenomena, excluding the fact that cell cultures are very heterogeneous. Single-cell analysis, on the other hand, offers more detailed insight into population variability, thereby facilitating a considerably deeper understanding of cell physiology. Although microscopy methods can address this issue, they suffer from limitations in terms of the small number of individual cells that can be studied and complicated image processing. We developed a noninvasive high-throughput method that employs flow cytometry to analyze large populations of cells that express pHluorin, a genetically encoded ratiometric fluorescent probe that is sensitive to pH. The method described here enables measurement of the intracellular pH of single cells with high sensitivity and speed, which is a clear improvement compared to previously published methods that either require pretreatment of the cells, measure cell populations, or require complex data analysis. The ratios of fluorescence intensities, which correlate to the intracellular pH, are independent of the expression levels of the pH probe, making the use of transiently or extrachromosomally expressed probes possible. We conducted an experiment on the kinetics of the pH homeostasis ofSaccharomyces cerevisiaecultures grown to a stationary phase after ethanol or glucose addition and after exposure to weak acid stress and glucose pulse. Minor populations with pH homeostasis behaving differently upon treatments were identified.
Changing Dietary Calcium-Phosphorus Level and Cereal Source Selectively Alters Abundance of Bacteria and Metabolites in the Upper Gastrointestinal Tracts of Weaned Pigs
Authors: Metzler-Zebeli Barbara U. , Mann Evelyne , Schmitz-Esser Stephan , Wagner Martin , Ritzmann Mathias , Zebeli Qendrim
Published: September 2013

Several dietary ingredients may affect the bacterial community structure and metabolism in the porcine gut and may therefore influence animals' health and performance. This study investigated the effects of cereal source and calcium-phosphorus (CaP) level in the diet on bacterial microbiota and metabolites, nutrient intake, and gut environment in weaned pigs. Pigs (
n
= 8/treatment) were fed wheat-barley- or corn-based diets with an adequate or high CaP level for 14 days. Effects on microbiota in the stomach, ileum, and midcolon were assessed using quantitative PCR. Data showed that
Enterobacteriaceae
,
Campylobacter
spp., and
Helicobacter
spp., which all contain highly immune reactive lipopolysaccharide (LPS), were abundant at all gut sites. Diet effects on bacteria and metabolites were moderate and occurred mainly in the upper gut, whereas no effects on bacteria, fermentation products, and LPS could be observed in the colon. Differences in carbohydrate intake with corn versus wheat-barley diets selectively stimulated
Bifidobacterium
in the stomach and ileum. There was a growth advantage for a few bacterial groups in the stomach and ileum of pigs fed the high versus adequate CaP level (i.e., gastric
Enterobacteriaceae
and ileal
Enterococcus
,
Bacteroides-Prevotella-Porphyromonas
, and
Campylobacter
). Interestingly, gastrointestinal pH was not affected by dietary CaP level. The present findings demonstrate the stability of the bacterial community and gut environment toward dietary changes even in young pigs. The results on stimulation of gastric and ileal
Bifidobacterium
by corn diets may be employed in nutritional strategies to support gut health after weaning.
Termites Facilitate Methane Oxidation and Shape the Methanotrophic Community
Authors: Ho Adrian , Erens Hans , Mujinya Basile Bazirake , Boeckx Pascal , Baert Geert , Schneider Bellinda , Frenzel Peter , Boon Nico , Van Ranst Eric
Published: September 2013

Termite-derived methane contributes 3 to 4% to the total methane budget globally. Termites are not known to harbor methane-oxidizing microorganisms (methanotrophs). However, a considerable fraction of the methane produced can be consumed by methanotrophs that inhabit the mound material, yet the methanotroph ecology in these environments is virtually unknown. The potential for methane oxidation was determined using slurry incubations under conditions with high (12%) and
in situ
(∼0.004%) methane concentrations through a vertical profile of a termite (
Macrotermes falciger
) mound and a reference soil. Interestingly, the mound material showed higher methanotrophic activity. The methanotroph community structure was determined by means of a
pmoA
-based diagnostic microarray. Although the methanotrophs in the mound were derived from populations in the reference soil, it appears that termite activity selected for a distinct community. Applying an indicator species analysis revealed that putative atmospheric methane oxidizers (high-indicator-value probes specific for the JR3 cluster) were indicative of the active nest area, whereas methanotrophs belonging to both type I and type II were indicative of the reference soil. We conclude that termites modify their environment, resulting in higher methane oxidation and selecting and/or enriching for a distinct methanotroph population.
Abi Is Required for Modulation and Stability but Not Localization or Activation of the SCAR/WAVE Complex
Authors: Davidson Andrew J. , Ura Seiji , Thomason Peter A. , Kalna Gabriela , Insall Robert H.
Published: September 2013

The SCAR/WAVE complex drives actin-based protrusion, cell migration, and cell separation during cytokinesis. However, the contribution of the individual complex members to the activity of the whole remains a mystery. This is primarily because complex members depend on one another for stability, which limits the scope for experimental manipulation. Several studies suggest that Abi, a relatively small complex member, connects signaling to SCAR/WAVE complex localization and activation through its polyproline C-terminal tail. We generated a deletion series of the
Dictyostelium discoideum
Abi to investigate its exact role in regulation of the SCAR complex and identified a minimal fragment that would stabilize the complex. Surprisingly, loss of either the N terminus of Abi or the C-terminal polyproline tail conferred no detectable defect in complex recruitment to the leading edge or the formation of pseudopods. A fragment containing approximately 20% Abi—and none of the sites that couple to known signaling pathways—allowed the SCAR complex to function with normal localization and kinetics. However, expression of N-terminal Abi deletions exacerbated the cytokinesis defect of the
Dictyostelium abi
mutant, which was earlier shown to be caused by the inappropriate activation of SCAR. This demonstrates, unexpectedly, that Abi does not mediate the SCAR complex's ability to make pseudopods, beyond its role in complex stability. Instead, we propose that Abi has a modulatory role when the SCAR complex is activated through other mechanisms.
Dictyostelium Lipid Droplets Host Novel Proteins
Authors: Du Xiaoli , Barisch Caroline , Paschke Peggy , Herrfurth Cornelia , Bertinetti Oliver , Pawolleck Nadine , Otto Heike , Rühling Harald , Feussner Ivo , Herberg Friedrich W. , Maniak Markus
Published: September 2013

Across all kingdoms of life, cells store energy in a specialized organelle, the lipid droplet. In general, it consists of a hydrophobic core of triglycerides and steryl esters surrounded by only one leaflet derived from the endoplasmic reticulum membrane to which a specific set of proteins is bound. We have chosen the unicellular organism
Dictyostelium discoideum
to establish kinetics of lipid droplet formation and degradation and to further identify the lipid constituents and proteins of lipid droplets. Here, we show that the lipid composition is similar to what is found in mammalian lipid droplets. In addition, phospholipids preferentially consist of mainly saturated fatty acids, whereas neutral lipids are enriched in unsaturated fatty acids. Among the novel protein components are LdpA, a protein specific to
Dictyostelium
, and Net4, which has strong homologies to mammalian DUF829/Tmem53/NET4 that was previously only known as a constituent of the mammalian nuclear envelope. The proteins analyzed so far appear to move from the endoplasmic reticulum to the lipid droplets, supporting the concept that lipid droplets are formed on this membrane.
SPO71
Encodes a Developmental Stage-Specific Partner for Vps13 in Saccharomyces cerevisiae
Authors: Park Jae-Sook , Okumura Yuuya , Tachikawa Hiroyuki , Neiman Aaron M.
Published: September 2013

The creation of haploid gametes in yeast, termed spores, requires the
de novo
formation of membranes within the cytoplasm. These membranes, called prospore membranes, enclose the daughter nuclei generated by meiosis. Proper growth and closure of prospore membranes require the highly conserved Vps13 protein. Mutation of
SPO71
, a meiosis-specific gene first identified as defective in spore formation, was found to display defects in membrane morphogenesis very similar to those seen in
vps13
Δ cells. Specifically, prospore membranes are smaller than in the wild type, they fail to close, and membrane vesicles are present within the prospore membrane lumen. As in
vps13
Δ cells, the levels of phophatidylinositol-4-phosphate are reduced in the prospore membranes of
spo71
Δ cells.
SPO71
is required for the translocation of Vps13 from the endosome to the prospore membrane, and ectopic expression of
SPO71
in vegetative cells results in mislocalization of Vps13. Finally, the two proteins can be coprecipitated from sporulating cells. We propose that Spo71 is a sporulation-specific partner for Vps13 and that they act in concert to regulate prospore membrane morphogenesis.
Complete Genome Sequences of Two Bovine Viral Diarrhea Viruses Isolated from Brain Tissues of Nonambulatory (Downer) Cattle
Authors: Oem Jae-Ku , Joo Soo-Kyung , An Dong-Jun
Published: September 2013

Here, we report the complete genome sequences of two bovine viral diarrhea viruses (BVDVs) (strains 11F011 and 12F004) isolated from brain tissues from nonambulatory (downer) cattle. The complete genomes of strains 11F011 and 12F004 contain 12,287 nucleotides (nt) with a single large open reading frame and 12,301 nt with a single large open reading frame, respectively. Phylogenetic analysis indicated that these strains belong to the BVDV-2a and -1b genotypes, respectively.
First Insights into the Genome of the Gram-Negative, Endospore-Forming Organism Sporomusa ovata Strain H1 DSM 2662
Authors: Poehlein Anja , Gottschalk Gerhard , Daniel Rolf
Published: September 2013

The genome of
Sporomusa ovata
strain H1 DSM 2662, an anaerobic, Gram-negative endospore-forming bacterium, was sequenced.
S. ovata
uses
N
-methyl compounds, primary alcohols, fatty acids, and H
2
and CO
2
as energy and carbon sources to produce acetate. The genome harbors one chromosome, which encodes proteins typical for sporulation.
The Second Messenger Cyclic Di-GMP Regulates Clostridium difficile Toxin Production by Controlling Expression of
sigD
Authors: McKee Robert W. , Mangalea Mihnea R. , Purcell Erin B. , Borchardt Erin K. , Tamayo Rita
Published: September 2013

The Gram-positive obligate anaerobe
Clostridium difficile
causes potentially fatal intestinal diseases. How this organism regulates virulence gene expression is poorly understood. In many bacterial species, the second messenger cyclic di-GMP (c-di-GMP) negatively regulates flagellar motility and, in some cases, virulence. c-di-GMP was previously shown to repress motility of
C. difficile
. Recent evidence indicates that flagellar gene expression is tightly linked with expression of the genes encoding the two
C. difficile
toxins TcdA and TcdB, which are key virulence factors for this pathogen. Here, the effect of c-di-GMP on expression of the toxin genes
tcdA
and
tcdB
was determined, and the mechanism connecting flagellar and toxin gene expressions was examined. In
C. difficile
, increasing c-di-GMP levels reduced the expression levels of
tcdA
and
tcdB
, as well as that of
tcdR
, which encodes an alternative sigma factor that activates
tcdA
and
tcdB
expression. We hypothesized that the
C. difficile
orthologue of the flagellar alternative sigma factor SigD (FliA; σ
28
) mediates regulation of toxin gene expression in response to c-di-GMP. Indeed, ectopic expression of
sigD
in
C. difficile
resulted in increased expression levels of
tcdR
,
tcdA
, and
tcdB
. Furthermore,
sigD
expression enhanced toxin production and increased the cytopathic effect of
C. difficile
on cultured fibroblasts. Finally, evidence is provided that SigD directly activates
tcdR
expression and that SigD cannot activate
tcdA
or
tcdB
expression independent of TcdR. Taken together, these data suggest that SigD positively regulates toxin genes in
C. difficile
and that c-di-GMP can inhibit both motility and toxin production via SigD, making this signaling molecule a key virulence gene regulator in
C. difficile
.
Identification, Purification, and Characterization of a Novel Amino Acid Racemase, Isoleucine 2-Epimerase, from Lactobacillus Species
Authors: Mutaguchi Yuta , Ohmori Taketo , Wakamatsu Taisuke , Doi Katsumi , Ohshima Toshihisa
Published: September 2013

Accumulation of
d
-leucine,
d
-
allo
-isoleucine, and
d
-valine was observed in the growth medium of a lactic acid bacterium,
Lactobacillus otakiensis
JCM 15040, and the racemase responsible was purified from the cells and identified. The N-terminal amino acid sequence of the purified enzyme was GKLDKASKLI, which is consistent with that of a putative γ-aminobutyrate aminotransferase from
Lactobacillus buchneri
. The putative γ-aminobutyrate aminotransferase gene from
L. buchneri
JCM 1115 was expressed in recombinant
Escherichia coli
and then purified to homogeneity. The enzyme catalyzed the racemization of a broad spectrum of nonpolar amino acids. In particular, it catalyzed at high rates the epimerization of
l
-isoleucine to
d
-
allo
-isoleucine and
d
-
allo
-isoleucine to
l
-isoleucine. In contrast, the enzyme showed no γ-aminobutyrate aminotransferase activity. The relative molecular masses of the subunit and native enzyme were estimated to be about 49 kDa and 200 kDa, respectively, indicating that the enzyme was composed of four subunits of equal molecular masses. The

K
m

and
V
max
values of the enzyme for
l
-isoleucine were 5.00 mM and 153 μmol·min
−1
·mg
−1
, respectively, and those for
d
-
allo
-isoleucine were 13.2 mM and 286 μmol·min
−1
·mg
−1
, respectively. Hydroxylamine and other inhibitors of pyridoxal 5′-phosphate-dependent enzymes completely blocked the enzyme activity, indicating the enzyme requires pyridoxal 5′-phosphate as a coenzyme. This is the first evidence of an amino acid racemase that specifically catalyzes racemization of nonpolar amino acids at the C-2 position.
Diversity of Cobalamin Riboswitches in the Corrinoid-Producing Organohalide Respirer Desulfitobacterium hafniense
Authors: Choudhary Pallavi K. , Duret Aurélie , Rohrbach-Brandt Emmanuelle , Holliger Christof , Sigel Roland K. O. , Maillard Julien
Published: September 2013

The strategic adaptation of prokaryotes in polluted niches involves the efficient regulation of their metabolism. The obligate anaerobe and metabolically versatileDesulfitobacterium hafniensereductively dechlorinates halogenated organic compounds (so-called organohalides). SomeD. hafniensestrains carry out organohalide respiration (OHR), a process which requires the use of corrinoid as a cofactor in reductive dehalogenases, the key enzymes in OHR. We report here the diversity of the cobalamin riboswitches that possibly regulate the corrinoid metabolism forD. hafniense. The analysis of availableD. hafniensegenomes indicates the presence of 18 cobalamin riboswitches located upstream of genes whose products are mainly involved in corrinoid biosynthesis and transport. To obtain insight into their function, the secondary structures of three of these RNA elements were predicted by Mfold, as well as analyzed by in-line probing. These RNA elements both display diversity in their structural elements and exhibit various affinities toward adenosylcobalamin that possibly relates to their role in the regulation of corrinoid metabolism. Furthermore, adenosylcobalamin-inducedin vivorepression of RNA synthesis of the downstream located genes indicates that the corrinoid transporters and biosynthetic enzymes inD. hafniensestrain TCE1 are regulated at the transcriptional level. Taken together, the riboswitch-mediated regulation of the complex corrinoid metabolism inD. hafniensecould be of crucial significance in environments polluted with organohalides both to monitor their intracellular corrinoid level and to coexist with corrinoid-auxotroph OHR bacteria.
MecA Protein Acts as a Negative Regulator of Genetic Competence in Streptococcus mutans
Authors: Tian Xiao-Lin , Dong Gaofeng , Liu Tianlei , Gomez Zubelda A. , Wahl Astrid , Hols Pascal , Li Yung-Hua
Published: September 2013

Streptococcus mutans
develops competence for genetic transformation through a complex network that receives inputs from at least two signaling peptides, competence-stimulating peptide (CSP) and
sigX
-inducing peptide (XIP). The key step of competence induction is the transcriptional activation of
comX
, which encodes an alternative sigma factor, SigX (σ
X
), controlling the expression of late competence genes essential for DNA uptake and recombination. In this study, we provide evidence that MecA acts as a negative regulator in the posttranslational regulation of SigX in
S. mutans
. Using
luxAB
transcriptional reporter strains, we demonstrate that MecA represses the expression of late competence genes in
S. mutans
grown in a complex medium that is subpermissive for competence induction by CSP. The negative regulation of competence by MecA requires the presence of a functional SigX. Accordingly, inactivation of MecA results in a prolonged competence state of
S. mutans
under this condition. We have also found that the AAA+ protease ClpC displays a similar repressing effect on late competence genes, suggesting that both MecA and ClpC function coordinately to regulate competence in the same regulatory circuit in
S. mutans
. This suggestion is strongly supported by the results of bacterial two-hybrid assays, which demonstrate that MecA interacts with both SigX and ClpC, forming a ternary SigX-MecA-ClpC complex. Western blot analysis also confirms that inactivation of MecA or ClpC results in the intracellular accumulation of the SigX in
S. mutans
. Together, our data support the notion that MecA mediates the formation of a ternary SigX-MecA-ClpC complex that sequesters SigX and thereby negatively regulates genetic competence in
S. mutans
.
VhuD Facilitates Electron Flow from H
2
or Formate to Heterodisulfide Reductase in Methanococcus maripaludis
Authors: Costa Kyle C. , Lie Thomas J. , Xia Qin , Leigh John A.
Published: September 2013

Flavin-based electron bifurcation has recently been characterized as an essential energy conservation mechanism that is utilized by hydrogenotrophic methanogenic
Archaea
to generate low-potential electrons in an ATP-independent manner. Electron bifurcation likely takes place at the flavin associated with the α subunit of heterodisulfide reductase (HdrA). In
Methanococcus maripaludis
the electrons for this reaction come from either formate or H
2
via formate dehydrogenase (Fdh) or Hdr-associated hydrogenase (Vhu). However, how these enzymes bind to HdrA to deliver electrons is unknown. Here, we present evidence that the δ subunit of hydrogenase (VhuD) is central to the interaction of both enzymes with HdrA. When
M. maripaludis
is grown under conditions where both Fdh and Vhu are expressed, these enzymes compete for binding to VhuD, which in turn binds to HdrA. Under these conditions, both enzymes are fully functional and are bound to VhuD in substoichiometric quantities. We also show that Fdh copurifies specifically with VhuD in the absence of other hydrogenase subunits. Surprisingly, in the absence of Vhu, growth on hydrogen still occurs; we show that this involves F
420
-reducing hydrogenase. The data presented here represent an initial characterization of specific protein interactions centered on Hdr in a hydrogenotrophic methanogen that utilizes multiple electron donors for growth.
Excellent reliability for MRI grading and prognostic parameters in acute hamstring injuries
Authors: Hamilton B , Whiteley R , Almusa E , Roger B , Geertsema C , Tol Johannes L
Published: September 2013

Background

Categorical grading and other measurable MRI parameters are frequently utilised for predicting the outcome of hamstring injuries. However, the reliability and smallest detectable difference (SDD) have not been previously evaluated. It therefore remains unclear if the variability in previously reported results reflects reporting variation or actual injury status.

Methods

25 hamstring injuries were scored by two experienced radiologists using the Peetrons grading and specific prognostic MRI parameters: distance from ischial tuberosity (cm), extent (cranio to caudal, anterior to posterior, medial to lateral; (cm)), maximum cross-sectional area (%), volume (cm3) of the oedema. The interobserver and intraobserver reliability was calculated along with the SDDs for each scale variable.

Results

There were 3 Grade 0 (12%), 11 grade 1 (44%), 9 grade 2 (36%) and 2 grade 3 (8%) injuries. Cronbach's α values for grading were 1.00 (inter) and 0.96 (intra), respectively. The intraclass correlation coefficients for the prognostic MRI parameters were between 0.77 and 1.0. The SDDs varied between each parameter.

Conclusions

Excellent interobserver and intraobserver reliability was found for grading and prognostic MRI parameters in acute hamstring injuries. In daily practice and research, we can be confident that scoring hamstring injuries by experienced radiologists is reproducible. The documented SDDs allow meaningful clinical inferences to be made when assessing observed and reported changes in MRI status.
Physical activity during pregnancy and the risk of gestational diabetes mellitus: a systematic review and meta-analysis of randomised controlled trials
Authors: Yin Ya-nan , Li Xiang-lian , Tao Tie-jun , Luo Bi-ru , Liao Shu-juan
Published: September 2013

Objectives

We performed a systematic review and meta-analysis to assess the effects of physical activity in preventing gestational diabetes mellitus (GDM).

Search strategy

We searched the literature in six electronic databases and bibliographies of relevant articles.

Selection criteria

We included randomised controlled trials on pregnant women who did not have GDM and other complications previously and had increased physical activity as the only intervention. The risk of developing GDM was documented separately for the intervention and control groups.

Data collection and analysis

Two reviewers extracted data and assessed quality independently. Data from the included trials were combined using a fixed-effects model. The effect size was expressed as relative risk (RR) and 95% CI.

Main results

Of the 1110 studies identified, six randomised controlled trials met the inclusion criteria. In three trials, the incidence of GDM was lower in the intervention group than in the control group, whereas two trials showed a higher incidence of GDM in the intervention group and the remaining trial found no GDM in either the intervention or control group. The meta-analysis resulted in a relative risk (RR) of GDM of 0.91 (95% CI 0.57 to 1.44), suggesting no significant difference in the risk of developing GDM between the intervention and the control groups. No indication of publication bias was found.

Conclusions

Evidence was insufficient to suggest that physical activity during pregnancy might be effective to lower the risk of developing GDM.
Impairment of brainstem implicit learning paradigms differentiates multiple system atrophy (MSA) from idiopathic Parkinson syndrome
Authors: von Lewinski Friederike , Schwan Michaela , Paulus Walter , Trenkwalder Claudia , Sommer Martin
Published: September 2013

Objectives

Learning as measured by eyeblink classical conditioning is preserved in patients with idiopathic Parkinson's disease, but severely affected in patients with progressive supranuclear palsy. We here sought to clarify whether procedural learning is impaired in multiple system atrophy (MSA), and whether it may be helpful for the differentiation of parkinsonian syndromes.

Design

We investigated learning using (1) eyeblink classical conditioning with a delay (interstimulus interval 0 ms) and a trace (600 ms) paradigm and (2) a serial reaction time task.

Setting

Participants were recruited from academic research centres.

Participants

11 patients with MSA and 11 healthy controls.

Results

Implicit learning in eyeblink classical conditioning (acquisition of conditioned responses) as well as the serial reaction time task measures of implicit learning (reaction time change) are impaired in patients with MSA as compared with controls, whereas explicit learning as measured by the sequence recall of the serial reaction time task is relatively preserved.

Analysis

We hypothesise that the learning deficits of patients with MSA are due to lesions of cerebellar and connected brainstem areas.

Conclusions

A retrospective synopsis of these novel data on patients with MSA and groups of patients with idiopathic Parkinson's disease and progressive supranuclear palsy studied earlier suggest that eyeblink classical conditioning may contribute to the early differentiation of atypical Parkinson syndromes from idiopathic Parkinson's disease. This hypothesis should be tested in a prospective trial.
Acute exacerbation in rheumatoid arthritis-associated interstitial lung disease: a retrospective case control study
Authors: Hozumi Hironao , Nakamura Yutaro , Johkoh Takeshi , Sumikawa Hiromitsu , Colby Thomas V , Kono Masato , Hashimoto Dai , Enomoto Noriyuki , Fujisawa Tomoyuki , Inui Naoki , Suda Takafumi , Chida Kingo
Published: September 2013

Objectives

To investigate the risk factors and prognosis associated with acute exacerbation (AE) in patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

Design

A retrospective case–control study.

Setting

A single academic hospital.

Participants

51 consecutive patients diagnosed with RA-ILD between 1995 and 2012. All patients fulfilled the diagnostic criteria of the American College of Rheumatology for RA. ILD was diagnosed on the basis of clinical presentation, pulmonary function tests, high-resolution CT (HRCT) findings and lung biopsy findings.

Main outcome measures

Overall survival and cumulative AE incidence were analysed using Kaplan-Meier method. Cox hazards analysis was used to determine significant variables associated with AE occurrence and survival status.

Results

A total of 11 patients (22%) developed AE, with an overall 1-year incidence of 2.8%. Univariate analysis revealed that older age at ILD diagnosis (HR 1.11; 95% CI 1.02 to 1.21; p=0.01), usual interstitial pneumonia (UIP) pattern on HRCT (HR 1.95; 95% CI 1.07 to 3.63; p=0.03) and methotrexate usage (HR 3.04; 95% CI 1.62 to 6.02; p=0.001) were associated with AE. Of 11 patients who developed AE during observation period, 7 (64%) died of initial AE. In survival, AE was a prognostic factor for poor outcome (HR 2.47; 95% CI 1.39 to 4.56; p=0.003).

Conclusions

In patients with RA-ILD, older age at ILD diagnosis, UIP pattern on HRCT and methotrexate usage are associated with the development of AE. Furthermore, AE has a serious impact on their survival.
The value of personalised risk information: a qualitative study of the perceptions of patients with prostate cancer
Authors: Han Paul K J , Hootsmans Norbert , Neilson Michael , Roy Bethany , Kungel Terence , Gutheil Caitlin , Diefenbach Michael , Hansen Moritz
Published: September 2013

Objective

To explore the experiences of patients with prostate cancer with risk information and their perceptions of the value of personalised risk information in treatment decisions.

Design

A qualitative study was conducted using focus groups. Semistructured interviews explored participants’ experiences with using risk information, and their perceptions of the potential value of personalised risk information produced by clinical prediction models.

Participants

English-speaking patients, ages 54–82, diagnosed with prostate cancer within the past 3 years, residing in rural and non-rural geographic locations in Maine (USA), and attending prostate cancer patient support groups.

Setting

6 focus groups were conducted with 27 patients; separate groups were held for patients with low-risk, medium-risk and high-risk disease defined by National Comprehensive Cancer Network guidelines.

Results

Several participants reported receiving risk information that was imprecise rather than precise, qualitative rather than quantitative, indirect rather than direct and focused on biomarker values rather than clinical outcomes. Some participants felt that personalised risk information could be useful in helping them make better informed decisions, but expressed scepticism about its value. Many participants favoured decision-making strategies that were heuristic-based and intuitive rather than risk-based and deliberative, and perceived other forms of evidence—emotions, recommendations of trusted physicians, personal narratives—as more reliable and valuable in treatment decisions.

Conclusions

Patients with prostate cancer appear to have little experience using personalised risk information, may favour heuristic-based over risk-based decision-making strategies and may perceive personalised risk information as less valuable than other types of evidence. These decision-making approaches and perceptions represent potential barriers to the clinical use of personalised risk information. Overcoming these barriers will require providing patients with greater exposure to risk information, education about the nature and value of personalised risk information and training in deliberative decision-making strategies. More research is needed to confirm these findings and address these needs.
Representativeness and optimal use of body mass index (BMI) in the UK Clinical Practice Research Datalink (CPRD)
Authors: Bhaskaran Krishnan , Forbes Harriet J , Douglas Ian , Leon David A , Smeeth Liam
Published: September 2013

Objectives

To assess the completeness and representativeness of body mass index (BMI) data in the Clinical Practice Research Datalink (CPRD), and determine an optimal strategy for their use.

Design

Descriptive study.

Setting

Electronic healthcare records from primary care.

Participants

A million patient random sample from the UK CPRD primary care database, aged ≥16 years.

Primary and secondary outcome measures

BMI completeness in CPRD was evaluated by age, sex and calendar period. CPRD-based summary BMI statistics for each calendar year (2003–2010) were age-standardised and sex-standardised and compared with equivalent statistics from the Health Survey for England (HSE).

Results

BMI completeness increased over calendar time from 37% in 1990–1994 to 77% in 2005–2011, was higher among females and increased with age. When BMI at specific time points was assigned based on the most recent record, calendar–year-specific mean BMI statistics underestimated equivalent HSE statistics by 0.75–1.1 kg/m2. Restriction to those with a recent (≤3 years) BMI resulted in mean BMI estimates closer to HSE (≤0.28 kg/m2underestimation), but excluded up to 47% of patients. An alternative strategy of imputing up-to-date BMI based on modelled changes in BMI over time since the last available record also led to mean BMI estimates that were close to HSE (≤0.37 kg/m2underestimation).

Conclusions

Completeness of BMI in CPRD increased over time and varied by age and sex. At a given point in time, a large proportion of the most recent BMIs are unlikely to reflect current BMI; consequent BMI misclassification might be reduced by employing model-based imputation of current BMI.
Myocardial infarction incidence and survival by ethnic group: Scottish Health and Ethnicity Linkage retrospective cohort study
Authors: Bansal Narinder , Fischbacher Colin M , Bhopal Raj S , Brown Helen , Steiner Markus FC , Capewell Simon ,   on behalf of the Scottish Health and Ethnicity Linkage Study
Published: September 2013

Objective

Inequalities in coronary heart disease mortality by country of birth are large and poorly understood. However, these data misclassify UK-born minority ethnic groups and provide little detail on whether excess risk is due to increased incidence, poorer survival or both.

Design

Retrospective cohort study.

Setting

General resident population of Scotland.

Participants

All those residing in Scotland during the 2001 Census were eligible for inclusion: 2 972 120 people were included in the analysis. The number still residing in Scotland at the end of the study in 2008 is not known.

Primary and secondary outcome measures

As specified in the analysis plan, the primary outcome measures were first occurrence of admission or death due to myocardial infarction and time to event. There were no secondary outcome measures.

Results

Acute myocardial infarction (AMI) incidence risk ratios (95% CIs) relative to white Scottish populations (100) were highest among Pakistani men (164.1 (142.2 to 189.2)) and women (153.7 (120.5, 196.1)) and lowest for men and women of Chinese (39.5 (27.1 to 57.6) and 59.1 (38.6 to 90.7)), other white British (77 (74.2 to 79.8) and 72.2 (69.0 to 75.5)) and other white (83.1 (75.9 to 91.0) and 79.9 (71.5 to 89.3)) ethnic groups. Adjustment for educational qualification did not eliminate these differences. Cardiac intervention uptake was similar across most ethnic groups. Compared to white Scottish, 28-day survival did not differ by ethnicity, except in Pakistanis where it was better, particularly in women (0.44 (0.25 to 0.78)), a difference not removed by adjustment for education, travel time to hospital or cardiac intervention uptake.

Conclusions

Pakistanis have the highest incidence of AMI in Scotland, a country renowned for internationally high cardiovascular disease rates. In contrast, survival is similar or better in minority ethnic groups. Clinical care and policy should focus on reducing incidence among Pakistanis through more aggressive prevention.
GPs’ perspectives on the management of patients with multimorbidity: systematic review and synthesis of qualitative research
Authors: Sinnott Carol , Mc Hugh Sheena , Browne John , Bradley Colin
Published: September 2013

Objective

To synthesise the existing published literature on the perceptions of general practitioners (GPs) or their equivalent on the clinical management of multimorbidity and determine targets for future research that aims to improve clinical care in multimorbidity.

Design

Systematic review and metaethnographic synthesis of primary studies that used qualitative methods to explore GPs’ experiences of clinical management of multimorbidity or multiple chronic diseases.

Data sources

EMBASE, MEDLINE, CINAHL, PsycInfo, Academic Search Complete, SocIndex, Social Science Full Text and digital theses/online libraries (database inception to September 2012) to identify literature using qualitative methods (focus groups or interviews).

Review methods

The 7-step metaethnographic approach described by Noblit and Hare, which involves cross-interpretation between studies while preserving the context of the primary data.

Results

Of 1805 articles identified, 37 were reviewed in detail and 10 were included, using a total of 275 GPs in 7 different countries. Four areas of difficulty specific to the management of multimorbidity emerged from these papers: disorganisation and fragmentation of healthcare; the inadequacy of guidelines and evidence-based medicine; challenges in delivering patient-centred care; and barriers to shared decision-making. A ‘line of argument’ was drawn which described GPs’ sense of isolation in decision-making for multimorbid patients.

Conclusions

This systematic review shows that the problem areas for GPs in the management of multimorbidity may be classified into four domains. There will be no ‘one size fits all’ intervention for multimorbidity but these domains may be useful targets to guide the development of interventions that will assist and improve the provision of care to multimorbid patients.
Antimicrobial resistance monitoring inNeisseria gonorrhoeaeand strategic use of funds from the Global Fund to set up a systematic Moroccan gonococcal antimicrobial surveillance programme
Authors: Hançali Amina , Ndowa Francis , Bellaji Bahija , Bennani Aziza , Kettani Amina , Charof Reda , Aouad Rajae El
Published: September 2013

Objectives

The aims of this study were to assess antimicrobial resistance inNeisseria gonorrhoeaeinfections and update the treatment in the national guidelines for the syndromic management of sexually transmitted infections in Morocco.

Methods

171 men complaining of urethral discharge were recruited from basic health services during 2009. Urethral swab samples were collected andN gonorrhoeaeidentification was performed by culture. Antimicrobial susceptibility testing was performed using the Etest method and the antimicrobial agents tested were ciprofloxacin, penicillin, spectinomycin, tetracycline, ceftriaxone and cefixime.

Results

A total of 72 isolates were examined. Significant resistance to tetracycline (92.8%) and ciprofloxacin (86.8%), which was used as first-line treatment in gonococcal infections, was noted. No resistance to spectinomycin, ceftriaxone or cefixime was detected in all the isolates.

Conclusions

Following these results the Ministry of Health of Morocco replaced ciprofloxacin and introduced ceftriaxone 250 mg as a single dose in the treatment of gonococcal infections. Using funds from the Global Fund to Fight AIDS, Tuberculosis and Malaria (the Global Fund), a surveillance programme was set up for antimicrobial resistance testing inN gonorrhoeae.
Mechanisms of maternal transfer of organochlorine contaminants and mercury in the common thresher shark (Alopias vulpinus)
Authors: Lyons Kady , Lowe Christopher G.
Published: September 2013

A putative mechanism for maternal transfer of organic contaminants and total mercury was empirically demonstrated in a near-term pregnant female common thresher shark (Alopias vulpinus). Contaminants were measured in the liver and muscle tissue of the mother and her four embryos, as well as the embryos’ stomach contents. Concentrations of organic contaminants and mercury were found to be lower in the embryos’ livers than in the mother’s and were clearly measurable in the embryo stomach contents, which consisted of consumed ovulated eggs. Presence of high concentrations of organic contaminants and mercury in embryos, prior to any exogenous exposure, provides clear evidence of maternal offloading in this species. In addition, the detection of these chemicals in the yolky stomach contents provides a mechanism by which oophagous elasmobranch females offload contaminants onto their young.
Influence of sex, migration distance, and latitude on life history expression in steelhead and rainbow trout (Oncorhynchus mykiss)
Authors: Ohms Haley A. , Sloat Matthew R. , Reeves Gordon H. , Jordan Chris E. , Dunham Jason B.
Published: September 2013

In partially migratory species, such as Oncorhynchus mykiss, the emergence of life history phenotypes is often attributed to fitness trade-offs associated with growth and survival. Fitness trade-offs can be linked to reproductive tactics that vary between the sexes, as well as the influence of environmental conditions. We found that O. mykiss outmigrants are more likely to be female in nine populations throughout western North America (grand mean 65% female), in support of the hypothesis that anadromy is more likely to benefit females. This bias was not related to migration distance or freshwater productivity, as indicated by latitude. Within one O. mykiss population we also measured the resident sex ratio and did not observe a male bias, despite a high female bias among outmigrants in that system. We provide a simulation to demonstrate the relationship between sex ratios and the proportion of anadromy and show how sex ratios could be a valuable tool for predicting the prevalence of life history types in a population.
Fish growth and degree-days I: selecting a base temperature for a within-population study
Authors: Chezik Kyle A. , Lester Nigel P. , Venturelli Paul A.
Published: September 2013

Degree-days (DD) are an increasingly popular method for explaining variation in fish growth and development. By including a base temperature (To) the DD formula limits calculations to temperatures that are relevant to growth. However, our review of growth studies shows multiple To values in use for a given fish species. To determine how To affects the ability of DD to explain within-population growth variation, we first show that the ability of DD to describe a growing season is robust to low values of To. We then analyze immature length data from eight species and 85 water bodies in North America to show that there is a broad range of To values that effectively explain growth variation. Based on these results, we argue that precise To estimates are unwarranted for most single-population studies and recommend standard To values (0, 5, 10, 15 °C). Standardization facilitates comparative studies and promotes the use of DD in future research. To this end, we provide equations for converting annual DD at a given To to annual DD at a standard To.
Cycloheximide and lipopolysaccharide downregulate αENaC mRNA via different mechanisms in alveolar epithelial cells
Authors: Migneault Francis , Boncoeur Émilie , Morneau Frédéric , Pascariu Mihai , Dagenais André , Berthiaume Yves
Published: September 2013

Active Na+ transport mediated by epithelial Na+ channel (ENaC) is vital for fetal lung fluid reabsorption at birth and pulmonary edema resolution. Previously, we demonstrated that αENaC expression and activity are downregulated in alveolar epithelial cells by cycloheximide (Chx) and Pseudomonas aeruginosa. The regulatory mechanisms of αENaC mRNA expression by Chx and lipopolysaccharide (LPS) from P. aeruginosa were further studied in the present work. Both agents decreased αENaC mRNA expression to 50% of control values after 4 h. Chx repressed αENaC expression in a dose-dependent manner independently of protein synthesis. Although extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) pathways were activated by the two treatments, their mechanisms of ENaC mRNA modulation were different. First, activation of the signaling pathways was sustained by Chx but only transiently by LPS. Second, ERK1/2 or p38 MAPK inhibition attenuated the effects of Chx on αENaC mRNA, whereas suppression of both signaling pathways was necessary to alleviate the outcome of LPS on αENaC mRNA. The molecular mechanisms involved in the decrease of αENaC expression were investigated in both conditions. LPS, but not Chx, significantly reduced αENaC promoter activity via the ERK1/2 and p38 MAPK pathways. These results suggest that LPS attenuates αENaC mRNA expression via diminution of transcription, whereas Chx could trigger some posttranscriptional mechanisms. Although LPS and Chx downregulate αENaC mRNA expression similarly and with similar signaling pathways, the mechanisms modulating ENaC expression are different depending on the nature of the cellular stress.
Hallmarks in the study of respiratory physiology and the crucial role of Antoine-Laurent de Lavoisier (1743–1794)
Authors: Karamanou Marianna , Tsoucalas Gregory , Androutsos George
Published: September 2013

From the early 17th century the advent of physical and chemical sciences developed two important movements toward the explanation of all vital phenomena: the Iatrochemical and Iatromechanical Schools. The important research of their representatives such as Jan Baptist van Helmont, John Mayow, Robert Boyle, Gian Alfonso Borelli, Richard Lower, and Albrecht von Haller, followed by the discovery of the atmospheric gases, provided a fecund soil for the leading work of Lavoisier in respiratory physiology.