bluuebunny/crossref_metadata_2025 huggingface dataset:
The gradient of electrical potential difference and of sodium and potassium of the gut contents along the caecum and colon of normal and sodium‐depleted rats
Authors: Edmonds C. J.
Published: December 2014

1. The Na, K and water content of stools, and of gut contents removed from the terminal ileum, caecum and colon were determined in normal and Na‐depleted rats and the p.d. across the colon wall measured at the site of removal of each specimen.

2. During passage through the caecum and colon, especially the ascending segment of colon, the faecal Na and water content fell considerably, K content being unchanged in the normal rats and falling in the Na‐depleted. Na concentration of the faecal water fell but K concentration rose owing to water absorption.

3. Feeding normal rats with a sulphonated polystyrene resin caused a considerable Na loss in the stool, the ratio Na/(Na+K) being consistently greater than in rats not taking resin. Resin induced little Na but much K loss in Na‐depleted rats.

4. The electrical p.d. across the colon wall varied little over the length of the caecum and colon in normal rats, rarely exceeding 20 mV, the serosa being +ve with respect to lumen. Potential difference measurements were greater in Na‐depleted rats, and those of the caecum and descending colon were consistently higher than those of the ascending colon. There was a similar pattern in resin‐fed rats but potentials tended to be higher.

5. K concentration of the gut contents was always greater than could be accounted for if K were passively distributed across the colonic mucosa.

6. It was concluded that: (i) active Na absorption was stimulated by Na depletion; (ii) K was probably actively transported into the colon lumen, and when unabsorbable anions were present in the gut K secretion was critically important in Na absorption; (iii) the elevation of p.d. associated with Na depletion was probably associated with the stimulated Na transport.
Transport of sodium and secretion of potassium and bicarbonate by the colon of normal and sodium‐depleted rats
Authors: Edmonds C. J.
Published: December 2014

1. Ascending and descending colonic segments of normal and Na‐depleted rats were perfused in vivo with isotonic solutions of varying Na concentration and the unidirectional Na fluxes and secretion rate of K and bicarbonate and the transmucosal electrical p.d. were measured.

2. Potential difference was greater in Na‐depleted rats, especially towards the distal end of the descending colon. With reduction of luminal Na concentration, p.d. was reduced.

3. The ascending and descending segments were similar in regard to Na transport except that the latter had lower passive permeability. Na depletion caused an increase of Na influx rate, Na net flux rate and Na exchange diffusion whilst the mucosal passive Na permeability decreased. These changes resulted in a reduction in the critical luminal Na concentration, i.e. the concentration at which the unidirectional fluxes were equal.

4. K secretion rate was similar in the ascending and descending colon and was increased by Na depletion. In all rats, it was reduced when the luminal Na concentration was low.

5. Bicarbonate secretion rate was unaffected by the Na depletion and all solutions remained isotonic during perfusion.

6. The results confirmed that active Na transport was stimulated by Na depletion but indicated that this was probably not the only factor in the elevation of transmucosal p.d.
The influence of the polar anastomotic vessels on autoregulation and the urinary excretion of water and sodium by perfused cat kidneys
Authors: Lockett Mary F.
Published: December 2014

1. Cat kidneys have been perfused from pump‐oxygenator and from heart‐lung circuits.

2. Kidneys perfused from the pump‐oxygenator circuit excreted more water and sodium and showed higher values for sodium: potassium in urine than kidneys perfused from heart—lung circuits. Renal plasma flow and the clearances of creatinine and p‐aminohippuric acid were similar for preparations perfused by the two different methods.

3. Dorsal and ventral polar anastomotic vessels appeared to communicate directly with sheaves of vasa recta in the kidneys of young cats through interlobar vessels.

4. Ligature of these polar anastomotic vessels impaired autoregulation of blood flow in perfused cat kidneys.

5. Open drainage from these polar vessels during perfusion increased the rates of excretion of water and sodium.

6. Histological preparations made from kidneys perfused from pump‐oxygenator and from heart—lung circuits for periods of 5‐6½ hr showed that the nephrons remain undamaged. The diameters of the tubules correlated with the rates of urine flow immediately before fixation.
Hormonal actions of the heart and of lungs on the isolated kidney
Authors: Lockett Mary F.
Published: December 2014

1. An hormonal influence of the heart on the isolated kidney has been demonstrated by insertion of hearts into pump‐oxygenator circuits during renal perfusions.

2. This hormone is a steroid which is secreted from the heart into the cardiac venous blood in response to reduction in venous input. The steroid is extractable from heart muscle.

3. The actions of the cardiac steroid resemble those of aldosterone but are of shorter latency. Renal blood flow (R.B.F.) and glomerular filtration rate (G.F.R.) rise; urine flow, Na‐concentration and Na/K decrease.

4. An hormonal influence of lungs on the isolated kidney is also demonstrated. This hormone is not a steroid. It is antidiuretic and Na‐retaining: the concentration of urinary Na rises: Na/K remains unchanged.
An analysis of facilitation of transmitter release at the neuromuscular junction of the frog
Authors: Mallart A. , Martin A. R.
Published: December 2014

1. Experiments were done on Mg‐blocked neuromuscular junctions of the frog to study in detail the magnitude and time course of facilitation of the end‐plate potential (e.p.p.).

2. When two shocks were applied to the motor nerve with an interval of 5 msec or less between them, the amplitude of the second e.p.p. was facilitated by approximately 100%. This facilitation decreased as the interval was lengthened.

3. The facilitation could be separated into two components on the basis of the time course of its decay as the interval between the two shocks was increased. The first component decayed exponentially after the conditioning shock with a time constant of about 35 msec. The second became apparent 60‐80 msec after the conditioning shock, rose to a maximum of approximately 15% at about 120 msec and decayed thereafter with a time constant of the order of 250 msec.

4. The growth of e.p.p. amplitude during short trains of repetitive stimulation at frequencies up to 100/sec and its subsequent decay could be predicted by assuming that the magnitude and time course of both components of facilitation were the same for every shock in the train and that these individual facilitatory effects summed linearly.
A quantitative study of cutaneous receptors and afferent fibres in the cat and rabbit
Authors: Brown A. G. , Iggo A.
Published: December 2014

1. The discharge in myelinated afferent fibres innervating hairs in anaesthetized cats and rabbits, dissected from the saphenous nerve, was recorded during controlled movements of the hairs.

2. Three types of rapidly adapting afferent unit were found and they innervated three kinds of hair follicle—down hair, guard hair and tylotrich.

3. The down hair units had low thresholds (critical slopes) and some of the guard hairs had the highest thresholds and least sensitivity to displacement.

4. There was a good fit to a power function for the relation between velocity of displacement of a hair and the frequency of discharge in the corresponding afferent fibre.

5. It is concluded that the rapidly adapting hair follicle receptors can function as efficient exact movement detectors.

6. Tylotrich follicles were often associated with touch corpuscles, but there was independent innervation of the rapidly adapting tylotrich follicle receptors and the slowly adapting touch corpuscle receptors.

7. The conduction velocities of large populations of myelinated cutaneous axons innervating cutaneous mechanoreceptors were measured in cats and rabbits.
Phaeobacter sp. Strain Y4I Utilizes Two Separate Cell-to-Cell Communication Systems To Regulate Production of the Antimicrobial Indigoidine
Authors: Cude W. Nathan , Prevatte Carson W. , Hadden Mary K. , May Amanda L. , Smith Russell T. , Swain Caleb L. , Campagna Shawn R. , Buchan Alison
Published: December 2014

The marine roseobacter
Phaeobacter
sp. strain Y4I synthesizes the blue antimicrobial secondary metabolite indigoidine when grown in a biofilm or on agar plates. Prior studies suggested that indigoidine production may be, in part, regulated by cell-to-cell communication systems.
Phaeobacter
sp. strain Y4I possesses two
luxR
and
luxI
homologous
N
-acyl-
l
-homoserine lactone (AHL)-mediated cell-to-cell communication systems, designated
pgaRI
and
phaRI
. We show here that Y4I produces two dominant AHLs, the novel monounsaturated
N
-(3-hydroxydodecenoyl)-
l
-homoserine lactone (3OHC
12:1
-HSL) and the relatively common
N
-octanoyl-
l
-homoserine lactone (C
8
-HSL), and provide evidence that they are synthesized by PhaI and PgaI, respectively. A Tn
5
insertional mutation in either genetic locus results in the abolishment (
pgaR
::Tn
5
) or reduction (
phaR
::Tn
5
) of pigment production. Motility defects and denser biofilms were also observed in these mutant backgrounds, suggesting an overlap in the functional roles of these systems. Production of the AHLs occurs at distinct points during growth on an agar surface and was determined by isotope dilution high-performance liquid chromatography–tandem mass spectrometry (ID-HPLC-MS/MS) analysis. Within 2 h of surface inoculation, only 3OHC
12:1
-HSL was detected in agar extracts. As surface-attached cells became established (at ∼10 h), the concentration of 3OHC
12:1
-HSL decreased, and the concentration of C
8
-HSL increased rapidly over 14 h. After longer (>24-h) establishment periods, the concentrations of the two AHLs increased to and stabilized at ∼15 nM and ∼600 nM for 3OHC
12:1
-HSL and C
8
-HSL, respectively. In contrast, the total amount of indigoidine increased steadily from undetectable to 642 μM by 48 h. Gene expression profiles of the AHL and indigoidine synthases (
pgaI
,
phaI
, and
igiD
) were consistent with their metabolite profiles. These data provide evidence that
pgaRI
and
phaRI
play overlapping roles in the regulation of indigoidine biosynthesis, and it is postulated that this allows
Phaeobacter
sp. strain Y4I to coordinate production of indigoidine with different growth-phase-dependent physiologies.
Organic Substances Interfere with Reverse Transcription-Quantitative PCR-Based Virus Detection in Water Samples
Authors: Hata Akihiko , Katayama Hiroyuki , Furumai Hiroaki
Published: December 2014

Reverse transcription (RT)-PCR-based virus detection from water samples is occasionally hampered by organic substances that are coconcentrated during virus concentration procedures. To characterize these organic substances, samples containing commercially available humic acid, which is known to inhibit RT-PCR, and river water samples were subjected to adsorption-elution-based virus concentration using an electronegative membrane. In this study, the samples before, during, and after the concentration were analyzed in terms of organic properties and virus detection efficiencies. Two out of the three humic acid solutions resulted in RT-quantitative PCR (qPCR) inhibition that caused >3-log
10
-unit underestimation of spiked poliovirus. Over 60% of the organics contained in the two solutions were recovered in the concentrate, while over 60% of the organics in the uninhibited solution were lost during the concentration process. River water concentrates also caused inhibition of RT-qPCR. Organic concentrations in the river water samples increased by 2.3 to 3.9 times after the virus concentration procedure. The inhibitory samples contained organic fractions in the 10- to 100-kDa size range, which are suspected to be RT-PCR inhibitors. According to excitation-emission matrices, humic acid-like and protein-like fractions were also recovered from river water concentrates, but these fractions did not seem to affect virus detection. Our findings reveal that detailed organic analyses are effective in characterizing inhibitory substances.
Gut Symbionts from Distinct Hosts Exhibit Genotoxic Activity via Divergent Colibactin Biosynthesis Pathways
Authors: Engel Philipp , Vizcaino Maria I. , Crawford Jason M.
Published: December 2014

Secondary metabolites produced by nonribosomal peptide synthetase (NRPS) or polyketide synthase (PKS) pathways are chemical mediators of microbial interactions in diverse environments. However, little is known about their distribution, evolution, and functional roles in bacterial symbionts associated with animals. A prominent example is colibactin, a largely unknown family of secondary metabolites produced by
Escherichia coli
via a hybrid NRPS-PKS biosynthetic pathway that inflicts DNA damage upon eukaryotic cells and contributes to colorectal cancer and tumor formation in the mammalian gut. Thus far, homologs of this pathway have only been found in closely related
Enterobacteriaceae
, while a divergent variant of this gene cluster was recently discovered in a marine alphaproteobacterial
Pseudovibrio
strain. Herein, we sequenced the genome of
Frischella perrara
PEB0191, a bacterial gut symbiont of honey bees and identified a homologous colibactin biosynthetic pathway related to those found in
Enterobacteriaceae
. We show that the colibactin genomic island (GI) has conserved gene synteny and biosynthetic module architecture across
F. perrara
,
Enterobacteriaceae
, and the
Pseudovibrio
strain. Comparative metabolomics analyses of
F. perrara
and
E. coli
further reveal that these two bacteria produce related colibactin pathway-dependent metabolites. Finally, we demonstrate that
F. perrara
, like
E. coli
, causes DNA damage in eukaryotic cells
in vitro
in a colibactin pathway-dependent manner. Together, these results support that divergent variants of the colibactin biosynthetic pathway are widely distributed among bacterial symbionts, producing related secondary metabolites and likely endowing its producer with functional capabilities important for diverse symbiotic associations.
Novel Reporter for Identification of Interference with Acyl Homoserine Lactone and Autoinducer-2 Quorum Sensing
Authors: Weiland-Bräuer Nancy , Pinnow Nicole , Schmitz Ruth A.
Published: December 2014

Two reporter strains were established to identify novel biomolecules interfering with bacterial communication (quorum sensing [QS]). The basic design of these
Escherichia coli
-based systems comprises a gene encoding a lethal protein fused to promoters induced in the presence of QS signal molecules. Consequently, these
E. coli
strains are unable to grow in the presence of the respective QS signal molecules unless a nontoxic QS-interfering compound is present. The first reporter strain designed to detect autoinducer-2 (AI-2)-interfering activities (AI2-QQ.1) contained the
E. coli
ccdB
lethal gene under the control of the
E. coli
lsrA
promoter. The second reporter strain (AI1-QQ.1) contained the
Vibrio fischeri
luxI
promoter fused to the
ccdB
gene to detect interference with acyl-homoserine lactones. Bacteria isolated from the surfaces of several marine eukarya were screened for quorum-quenching (QQ) activities using the established reporter systems AI1-QQ.1 and AI2-QQ.1. Out of 34 isolates, two interfered with acylated homoserine lactone (AHL) signaling, five interfered with AI-2 QS signaling, and 10 were demonstrated to interfere with both signal molecules. Open reading frames (ORFs) conferring QQ activity were identified for three selected isolates (
Photobacterium
sp.,
Pseudoalteromonas
sp., and
Vibrio parahaemolyticus
). Evaluation of the respective heterologously expressed and purified QQ proteins confirmed their ability to interfere with the AHL and AI-2 signaling processes.
Phosphoryl Transfer from α-d-Glucose 1-Phosphate Catalyzed by Escherichia coli Sugar-Phosphate Phosphatases of Two Protein Superfamily Types
Authors: Wildberger Patricia , Pfeiffer Martin , Brecker Lothar , Rechberger Gerald N. , Birner-Gruenberger Ruth , Nidetzky Bernd
Published: December 2014

The Cori ester α-d-glucose 1-phosphate (αGlc 1-P) is a high-energy intermediate of cellular carbohydrate metabolism. Its glycosidic phosphomonoester moiety primes αGlc 1-Pfor flexible exploitation in glucosyl and phosphoryl transfer reactions. Two structurally and mechanistically distinct sugar-phosphate phosphatases fromEscherichia coliwere characterized in this study for utilization of αGlc 1-Pas a phosphoryl donor substrate. Theagpgene encodes a periplasmic αGlc 1-Pphosphatase (Agp) belonging to the histidine acid phosphatase family. Had13 is from the haloacid dehydrogenase-like phosphatase family. Cytoplasmic expression of Agp (inE. coliOrigami B) gave a functional enzyme preparation (kcatfor phosphoryl transfer from αGlc 1-Pto water, 40 s−1) that was shown by mass spectrometry to exhibit no free cysteines and the native intramolecular disulfide bond between Cys189and Cys195. Enzymatic phosphoryl transfer from αGlc 1-Pto water in H218O solvent proceeded with complete18O label incorporation into the phosphate released, consistent with catalytic reaction through O-1–P, but not C-1–O, bond cleavage. Hydrolase activity of both enzymes was not restricted to a glycosidic phosphomonoester substrate, andd-glucose 6-phosphate was converted with akcatsimilar to that of αGlc 1-P. By examining phosphoryl transfer from αGlc 1-Pto an acceptor substrate other than water (d-fructose ord-glucose), we discovered that Agp exhibited pronounced synthetic activity, unlike Had13, which utilized αGlc 1-Pmainly for phosphoryl transfer to water. By applyingd-fructose in 10-fold molar excess over αGlc 1-P(20 mM), enzymatic conversion furnishedd-fructose 1-phosphate as the main product in a 55% overall yield. Agp is a promising biocatalyst for use in transphosphorylation from αGlc 1-P.
Use of mCherry Red Fluorescent Protein for Studies of Protein Localization and Gene Expression in Clostridium difficile
Authors: Ransom Eric M. , Ellermeier Craig D. , Weiss David S.
Published: December 2014

Fluorescent proteins are powerful reporters in biology, but most require O
2
for chromophore maturation, making them inherently difficult to use in anaerobic bacteria.
Clostridium difficile
, a strict anaerobe with a genomic GC content of only 29%, is the leading cause of hospital-acquired diarrhea in developed countries, and new methods for studying this pathogen are sorely needed. We recently demonstrated that a cyan fluorescent protein called CFP
opt
that has been codon optimized for production in low-GC bacteria can be used to study protein localization in
C. difficile
provided the cells are fixed prior to exposure to air. We describe here a codon-optimized variant of mCherry (mCherryOpt) that exhibits faster acquisition of fluorescence and a better signal-to-noise ratio than CFP
opt
. We utilized
mCherryOpt
to construct plasmids for studying protein localization (pRAN473) and gene expression (pDSW1728) in
C. difficile
. Plasmid pRAN473 is an
mCherryOpt
fusion vector with a tetracycline-inducible promoter. To document its biological utility, we demonstrated septal localization of two cell division proteins, MldA and ZapA. Plasmid pDSW1728 is designed for cloning a promoter of interest upstream of
mCherryOpt
. As proof of principle, we studied the expression of the
pdaV
operon, which is required for lysozyme resistance. In confirmation and extension of previous reports, we found that expression of the
pdaV
operon requires the alternative sigma factor σ
v
and that induction by lysozyme is dose dependent and uniform across the population of lysozyme-treated cells.
Integrative Conjugative Elements Are Widespread in Field Isolates of Mycoplasma Species Pathogenic for Ruminants
Authors: Tardy Florence , Mick Virginie , Dordet-Frisoni Emilie , Marenda Marc Serge , Sirand-Pugnet Pascal , Blanchard Alain , Citti Christine
Published: December 2014

Comparative genomics have revealed massive horizontal gene transfer (HGT) between
Mycoplasma
species sharing common ruminant hosts. Further results pointed toward an integrative conjugative element (ICE) as an important contributor of HGT in the small-ruminant-pathogen
Mycoplasma agalactiae
. To estimate the prevalence of ICEs in ruminant mycoplasmas, we surveyed their occurrence in a collection of 166 field strains representing 4 (sub)species that are recognized as major pathogens. Based on available sequenced genomes, we first defined the conserved, minimal ICE backbone as composed of 4 coding sequences (CDSs) that are evenly distributed and predicted to be essential for ICE chromosomal integration-excision and horizontal transfer. Screening of the strain collection revealed that these 4 CDSs are well represented in ruminant
Mycoplasma
species, suggesting widespread occurrence of ICEs. Yet their prevalence varies within and among species, with no correlation found with the individual strain history. Extrachromosomal ICE forms were also often detected, suggesting that ICEs are able to circularize in all species, a first and essential step in ICE horizontal transfer. Examination of the junction of the circular forms and comparative sequence analysis of conserved CDSs clearly pointed toward two types of ICE, the
hominis
and
spiroplasma
types, most likely differing in their mechanism of excision-integration. Overall, our data indicate the occurrence and maintenance of functional ICEs in a large number of field isolates of ruminant mycoplasmas. These may contribute to genome plasticity and gene exchanges and, presumably, to the emergence of diverse genotypes within pathogenic mycoplasmas of veterinary importance.
SUMOylation Is Developmentally Regulated and Required for Cell Pairing during Conjugation in Tetrahymena thermophila
Authors: Nasir Amjad M. , Yang Qianyi , Chalker Douglas L. , Forney James D.
Published: December 2014

The covalent attachment of
s
mall
u
biquitin-like
mo
difier (SUMO) to target proteins regulates numerous nuclear events in eukaryotes, including transcription, mitosis and meiosis, and DNA repair. Despite extensive interest in nuclear pathways within the field of ciliate molecular biology, there have been no investigations of the SUMO pathway in
Tetrahymena
. The developmental program of sexual reproduction of this organism includes cell pairing, micronuclear meiosis, and the formation of a new somatic macronucleus. We identified the
Tetrahymena thermophila
SMT3
(SUMO) and
UBA2
(SUMO-activating enzyme) genes and demonstrated that the corresponding green fluorescent protein (GFP) tagged gene products are found predominantly in the somatic macronucleus during vegetative growth. Use of an anti-Smt3p antibody to perform immunoblot assays with whole-cell lysates during conjugation revealed a large increase in SUMOylation that peaked during formation of the new macronucleus. Immunofluorescence using the same antibody showed that the increase was localized primarily within the new macronucleus. To initiate functional analysis of the SUMO pathway, we created germ line knockout cell lines for both the
SMT3
and
UBA2
genes and found both are essential for cell viability. Conditional Smt3p and Uba2p cell lines were constructed by incorporation of the cadmium-inducible metallothionein promoter. Withdrawal of cadmium resulted in reduced cell growth and increased sensitivity to DNA-damaging agents. Interestingly, Smt3p and Uba2p conditional cell lines were unable to pair during sexual reproduction in the absence of cadmium, consistent with a function early in conjugation. Our studies are consistent with multiple roles for SUMOylation in
Tetrahymena
, including a dynamic regulation associated with the sexual life cycle.
Effects of lixisenatide on elevated liver transaminases: systematic review with individual patient data meta-analysis of randomised controlled trials on patients with type 2 diabetes
Authors: Gluud Lise L , Knop Filip K , Vilsbøll Tina
Published: December 2014

Objective

To evaluate the effects of the glucagon-like peptide-1 receptor agonist lixisenatide on elevated liver blood tests in patients with type 2 diabetes.

Design

Systematic review.

Data sources

Electronic and manual searches were combined.

Study selection

Randomised controlled trials (RCTs) on lixisenatide versus placebo or active comparators for type 2 diabetes were included.

Participants

Individual patient data were retrieved to calculate outcomes for patients with elevated liver blood tests.

Main outcome measures

Normalisation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST).

Data synthesis

The results of included trials were combined in meta-analyses. Sequential, subgroup and regression analyses were performed to evaluate heterogeneity and bias.

Results

We included 12 RCTs on lixisenatide versus placebo and 3 RCTs with the active comparators liraglutide, exenatide or sitagliptin. The mean treatment duration was 29 weeks. Lixisenatide increased the proportion of patients with normalisation of ALT (risk difference: 0.07; 95% CI 0.01 to 0.14; number needed to treat: 14 patients, p=0.042). The effect was not confirmed in sequential analysis. No effects of lixisenatide were identified on AST, alkaline phosphatase or bilirubin. No evidence of bias was identified. Mixed effect multilevel meta-regression analyses suggest that the benefit of lixisenatide on ALT was limited to patients who were overweight or obese.

Conclusions

This review suggests that lixisenatide increases the proportion of obese or overweight patients with type 2 diabetes who achieve normalisation of ALT. Additional research is needed to determine if the findings translate to clinical outcome measures.

Trial registration number

PROSPERO; CRD42013005779.
Diagnostic accuracy study of three alcohol breathalysers marketed for sale to the public
Authors: Ashdown Helen F , Fleming Susannah , Spencer Elizabeth A , Thompson Matthew J , Stevens Richard J
Published: December 2014

Objectives

To assess the diagnostic accuracy of three personal breathalyser devices available for sale to the public marketed to test safety to drive after drinking alcohol.

Design

Prospective comparative diagnostic accuracy study comparing two single-use breathalysers and one digital multiuse breathalyser (index tests) to a police breathalyser (reference test).

Setting

Establishments licensed to serve alcohol in a UK city.

Participants

Of 222 participants recruited, 208 were included in the main analysis. Participants were eligible if they were 18 years old or over, had consumed alcohol and were not intending to drive within the following 6 h.

Outcome measures

Sensitivity and specificity of the breathalysers for the detection of being at or over the UK legal driving limit (35 µg/100 mL breath alcohol concentration).

Results

18% of participants (38/208) were at or over the UK driving limit according to the police breathalyser. The digital multiuse breathalyser had a sensitivity of 89.5% (95% CI 75.9% to 95.8%) and a specificity of 64.1% (95% CI 56.6% to 71.0%). The single-use breathalysers had a sensitivity of 94.7% (95% CI 75.4% to 99.1%) and 26.3% (95% CI 11.8% to 48.8%), and a specificity of 50.6% (95% CI 40.4% to 60.7%) and 97.5% (95% CI 91.4% to 99.3%), respectively. Self-reported alcohol consumption threshold of 5 UK units or fewer had a higher sensitivity than all personal breathalysers.

Conclusions

One alcohol breathalyser had sensitivity of 26%, corresponding to false reassurance for approximately one person in four who is over the limit by the reference standard, at least on the evening of drinking alcohol. The other devices tested had 90% sensitivity or higher. All estimates were subject to uncertainty. There is no clearly defined minimum sensitivity for this safety-critical application. We conclude that current regulatory frameworks do not ensure high sensitivity for these devices marketed to consumers for a decision with potentially catastrophic consequences.
The impact of exacerbation frequency on mortality following acute exacerbations of COPD: a registry-based cohort study
Authors: Schmidt Sigrun Alba Johannesdottir , Johansen Martin Berg , Olsen Morten , Xu Xiao , Parker Joseph M , Molfino Nestor A , Lash Timothy L , Sørensen Henrik Toft , Christiansen Christian Fynbo
Published: December 2014

Objective

To examine the association between exacerbation frequency and mortality following an acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Design

Cohort study using medical databases.

Setting

Northern Denmark.

Participants

On 1 January 2005, we identified all patients with prevalent hospital-diagnosed chronic obstructive pulmonary disease (COPD) who had at least one AECOPD during 1 January 2005 to 31 December 2009. We followed patients from the first AECOPD during this period until death, emigration or 31 December 2009, whichever came first. We flagged all AECOPD events during follow-up and characterised each by the exacerbation frequency (0, 1, 2 or 3+) in the prior 12-month period.

Main outcomes and measures

Using Cox regression, we computed 0–30-day and 31–365-day age-adjusted, sex-adjusted, and comorbidity-adjusted mortality rate ratios (MRRs) with 95% CIs entering exacerbation frequency as a time-varying exposure.

Results

We identified 16 647 eligible patients with prevalent COPD, of whom 6664 (40%) developed an AECOPD and were thus included in the study cohort. The 0–30-day MRRs were 0.97 (95% CI 0.80 to 1.18), 0.90 (95% CI 0.70 to 1.15) and 1.03 (95% CI 0.81 to 1.32) among patients with AECOPD with 1, 2 and 3+ AECOPDs versus no AECOPD within the past 12 months, respectively. The corresponding MRRs were 1.47 (95% CI 1.30 to 1.66), 1.89 (95% CI 1.59 to 2.25) and 1.59 (95% CI 1.23 to 2.05) for days 31–365.

Conclusion

Among patients with AECOPD, one or more exacerbations in the previous year were not associated with 30-day mortality but were associated with an increased 31–365-day mortality.
Air ambulance tasking: mechanism of injury, telephone interrogation or ambulance crew assessment?
Authors: Wilmer Ian , Chalk Graham , Davies Gareth Edward , Weaver Anne Elizabeth , Lockey David John
Published: December 2014

Objective

The identification of serious injury is critical to the tasking of air ambulances. London’s Air Ambulance (LAA) is dispatched by a flight paramedic based on mechanism of injury (MOI), paramedical interrogation of caller (INT) or land ambulance crew request (REQ).This study aimed to demonstrate which of the dispatch methods was most effective (in accuracy and time) in identifying patients with serious injury.

Methods

A retrospective review of 3 years of data (to December 2010) was undertaken. Appropriate dispatch was defined as the requirement for LAA to escort the patient to hospital or for resuscitation on-scene. Inaccurate dispatch was where LAA was cancelled or left the patient in the care of the land ambulance crew. The χ2test was used to calculate p values; with significance adjusted to account for multiple testing.

Results

There were 2203 helicopter activations analysed: MOI 18.9% (n=417), INT 62.4% (n=1375) and REQ 18.7% (n=411). Appropriate dispatch rates were MOI 58.7% (245/417), INT 69.7% (959/1375) and REQ 72.2% (297/411). INT and REQ were both significantly more accurate than MOI (p<0.0001). There was no significant difference in accuracy between INT and REQ (p=0.36). Combining MOI and INT remotely identified 80.2% of patients, with an overtriage rate of 32.8%. Mean time to dispatch (in minutes) was MOI 4, INT 8 and REQ 21.

Conclusions

Telephone interrogation of the caller by a flight paramedic is as accurate as ground ambulance crew requests, and both are significantly better than MOI in identifying serious injury. Overtriage remains an issue with all methods.
Republished: Just a drop of cement: a case of cervical spine bone aneurysmal cyst successfully treated by percutaneous injection of a small amount of polymethyl-methacrylate cement
Authors: Fahed Robert , Clarençon Frédéric , Riouallon Guillaume , Cormier Evelyne , Bonaccorsi Raphael , Pascal-Mousselard Hugues , Chiras Jacques
Published: December 2014

Aneurysmal bone cyst (ABC) is a benign hemorrhagic tumor, commonly revealed by local pain. The best treatment for this lesion is still controversial. We report the case of a patient with chronic neck pain revealing an ABC of the third cervical vertebra. After percutaneous injection of a small amount of polymethyl-methacrylate bone cement, the patient experienced significant clinical and radiological improvement.
Cilostazol: an antiplatelet agent for the neurointerventionist?
Authors: Bhogal P , Brouwer P A , Makalanda H L D
Published: December 2014

Antiplatelet agents are essential for the successful management of patients undergoing a variety of neurointerventional procedures. The most commonly used anti-platelet agents are aspirin, clopidogrel and prasugrel. However, there exist an alternative class of anti-platelet agent that may prove useful for neurointerventionists. In particular a drug called cilostazol may have numerous added advantages above and beyond its antiplatelet effect that may be valuable for our patients. In this short review we aim to highlight some of these potential advantages.
Knockdown of angiopoietin like-2 protects against angiotensin II-induced cerebral endothelial dysfunction in mice
Authors: Yu Carol , Luo Xiaoyan , Duquette Natacha , Thorin-Trescases Nathalie , Thorin Eric
Published: December 2014

Angiopoietin like-2 (angptl2) is a circulating pro-inflammatory and pro-oxidative protein, but its role in regulating cerebral endothelial function remains unknown. We hypothesized that in mice knockdown (KD) of angptl2, cerebral endothelial function would be protected against ANG II-induced damage. Subcutaneous infusion of ANG II (200 ng·kg−1·min−1, n = 15) or saline ( n = 15) was performed in 20-wk-old angptl2 KD mice and wild-type (WT) littermates for 14 days. In saline-treated KD and WT mice, the amplitude and the sensitivity of ACh-induced dilations of isolated cerebral arteries were similar. However, while endothelial nitric oxide (NO) synthase (eNOS)-derived O2−/H2O2 contributed to dilation in WT mice, eNOS-derived NO ( P < 0.05) was involved in KD mice. ANG II induced cerebral endothelial dysfunction only in WT mice ( P < 0.05), which was reversed ( P < 0.05) by either N-acetyl-l-cysteine, apocynin, gp91ds-tat, or indomethacin, suggesting the contribution of reactive oxygen species from Nox2 and Cox-derived contractile factors. In KD mice treated with ANG II, endothelial function was preserved, likely via Nox-derived H2O2, sensitive to apocynin and PEG-catalase ( P < 0.05), but not to gp91ds-tat. In the aorta, relaxation similarly and essentially depended on NO; endothelial function was maintained after ANG II infusion in all groups, but apocynin significantly reduced aortic relaxation in KD mice ( P < 0.05). Protein expression levels of Nox1/2 in cerebral arteries were similar among all groups, but that of Nox4 was greater ( P < 0.05) in saline-treated KD mice. In conclusion, knockdown of angptl2 may be protective against ANG II-induced cerebral endothelial dysfunction; it favors the production of NO, likely increasing endothelial cell resistance to stress, and permits the expression of an alternative vasodilatory Nox pathway.
Neutrophil extracellular traps in ischemia-reperfusion injury-induced myocardial no-reflow: therapeutic potential of DNase-based reperfusion strategy
Authors: Ge Lan , Zhou Xin , Ji Wen-Jie , Lu Rui-Yi , Zhang Yan , Zhang Yi-Dan , Ma Yong-Qiang , Zhao Ji-Hong , Li Yu-Ming
Published: December 2014

Emerging evidence suggests a potential role of neutrophil extracellular traps (NETs) in linking sterile inflammation and thrombosis. We hypothesized that NETs would be induced during myocardial ischemia-reperfusion (I/R), and NET-mediated microthrombosis may contribute to myocardial “no-reflow”. Male Wistar rats were randomly divided into I/R control, DNase (DNase I, 20 μg/rat), recombinant tissue-type plasminogen activator (rt-PA, 420 μg/rat), DNase + rt-PA, and sham control groups after 45-min myocardial ischemia. In situ NET formation, the anatomic “no re-flow” area, and infarct size were evaluated immediately after 3 h of reperfusion. Long-term left ventricular (LV) functional and histological analyses were performed 45 days after operation. Compared with the I/R controls, the DNase + rt-PA group exhibited reduced NET density [8.38 ± 1.98 vs. 26.86 ± 3.07 (per 200 × field), P < 0.001] and “no-flow” area (15.22 ± 0.06 vs. 34.6 ± 0.05%, P < 0.05) in the ischemic region, as well as reduced infarct size (38.39 ± 0.05 vs. 71.00 ± 0.03%, P < 0.001). Additionally, compared with the I/R controls, DNase + rt-PA treatment significantly ameliorated I/R injury-induced LV remodeling (LV ejection fraction: 64.22 ± 3.37 vs. 33.81 ± 2.98%, P < 0.05; LV maximal slope of the LV systolic pressure increment: 3,785 ± 216 vs. 2,596 ± 299 mmHg/s, P < 0.05). The beneficial effect was not observed in rats treated with DNase I or rt-PA alone. Our study provides evidence for the existence of NETs in I/R-challenged myocardium and confirms the long-term benefit of a novel DNase-based reperfusion strategy (DNase I + rt-PA), which might be a promising option for the treatment of myocardial I/R injury and coronary no-reflow.
Cardiac sympathetic afferent stimulation induces salt-sensitive sympathoexcitation through hypothalamic epithelial Na+ channel activation
Authors: Ito Koji , Hirooka Yoshitaka , Sunagawa Kenji
Published: December 2014

The cardiac sympathetic afferent (CSA), which plays an important role in heart-brain communication for sympathoexcitation, is stimulated in heart failure. Additionally, high salt intake leads to further sympathoexcitation due to activation of hypothalamic epithelial Na+ channels (ENaCs) in heart failure. In the present study, we stimulated the CSA in adult male mice by epicardial application of capsaicin and using ethanol as a control to determine whether CSA stimulation led to activation of hypothalamic ENaCs, resulting in salt-induced sympathoexcitation. Three days after capsaicin treatment, an upregulation of hypothalamic α-ENaCs, without activation of mineralocorticoid receptors, was observed. We also examined expression levels of the known ENaC activator TNF-α. Hypothalamic TNF-α increased in capsaicin-treated mice, whereas intracerebroventricular infusion of the TNF-α blocker etanercept prevented capsaicin-induced upregulation of α-ENaCs. To examine brain arterial pressure (AP) sensitivity toward Na+, we performed an intracerebroventricular infusion of high Na+-containing (0.2 M) artificial cerebrospinal fluid. AP and heart rate were significantly increased in capsaicin-treated mice compared with control mice. CSA stimulation also caused excitatory responses with high salt intake. Compared with a regular salt diet, the high-salt diet augmented AP, heart rate, and 24-h urinary norepinephrine excretion, which is an indirect marker of sympathetic activity with mineralocorticoid receptor activation, in capsaicin-treated mice but not in ethanol-treated mice. Treatment with etanercept or the ENaC blocker benzamil prevented these salt-induced excitatory responses. In summary, we show that CSA stimulation leads to an upregulation of hypothalamic α-ENaCs mediated via an increase in TNF-α and results in increased salt sensitivity.
Space radiation-associated lung injury in a murine model
Authors: Christofidou-Solomidou Melpo , Pietrofesa Ralph A. , Arguiri Evguenia , Schweitzer Kelly S. , Berdyshev Evgeny V. , McCarthy Maureen , Corbitt Astrid , Alwood Joshua S. , Yu Yongjia , Globus Ruth K. , Solomides Charalambos C. , Ullrich Robert L. , Petrache Irina
Published: December 2014

Despite considerable progress in identifying health risks to crewmembers related to exposure to galactic/cosmic rays and solar particle events (SPE) during space travel, its long-term effects on the pulmonary system are unknown. We used a murine risk projection model to investigate the impact of exposure to space-relevant radiation (SR) on the lung. C3H mice were exposed to 137Cs gamma rays, protons (acute, low-dose exposure mimicking the 1972 SPE), 600 MeV/u 56Fe ions, or 350 MeV/u 28Si ions at the NASA Space Radiation Laboratory at Brookhaven National Laboratory. Animals were irradiated at the age of 2.5 mo and evaluated 23.5 mo postirradiation, at 26 mo of age. Compared with age-matched nonirradiated mice, SR exposures led to significant air space enlargement and dose-dependent decreased systemic oxygenation levels. These were associated with late mild lung inflammation and prominent cellular injury, with significant oxidative stress and apoptosis (caspase-3 activation) in the lung parenchyma. SR, especially high-energy 56Fe or 28Si ions markedly decreased sphingosine-1-phosphate levels and Akt- and p38 MAPK phosphorylation, depleted anti-senescence sirtuin-1 and increased biochemical markers of autophagy. Exposure to SR caused dose-dependent, pronounced late lung pathological sequelae consistent with alveolar simplification and cellular signaling of increased injury and decreased repair. The associated systemic hypoxemia suggested that this previously uncharacterized space radiation-associated lung injury was functionally significant, indicating that further studies are needed to define the risk and to develop appropriate lung-protective countermeasures for manned deep space missions.
Strict Requirement for Vector-Induced Type I Interferon in Efficacious Antitumor Responses to Virally Encoded IL12
Authors: Melero Ignacio , Quetglas Jose I. , Reboredo Mercedes , Dubrot Juan , Rodriguez-Madoz Juan R. , Mancheño Uxua , Casales Erkuden , Riezu-Boj Jose I. , Ruiz-Guillen Marta , Ochoa Maria C. , Sanmamed Miguel F. , Thieblemont Nathalie , Smerdou Cristian , Hervas-Stubbs Sandra
Published: December 2014

Host responses are increasingly considered important for the efficacious response to experimental cancer therapies that employ viral vectors, but little is known about the specific nature of host responses required. In this study, we investigated the role of host type I interferons (IFN-I) in the efficacy of virally delivered therapeutic genes. Specifically, we used a Semliki Forest virus encoding IL12 (SFV-IL12) based on its promise as an RNA viral vector for cancer treatment. Intratumoral injection of SFV-IL12 induced production of IFN-I as detected in serum. IFN-I production was abolished in mice deficient for the IFNβ transcriptional regulator IPS-1 and partially attenuated in mice deficient for the IFNβ signaling protein TRIF. Use of bone marrow chimeric hosts established that both hematopoietic and stromal cells were involved in IFN-I production. Macrophages, plasmacytoid, and conventional dendritic cells were each implicated based on cell depletion experiments. Further, mice deficient in the IFN-I receptor (IFNAR) abolished the therapeutic activity of SFV-IL12, as did a specific antibody-mediated blockade of IFNAR signaling. Reduced efficacy was not caused by an impairment in IL12 expression, because IFNAR-deficient mice expressed the viral IL12 transgene even more strongly than wild-type (WT) hosts. Chimeric host analysis for the IFNAR involvement established a strict requirement in hematopoietic cells. Notably, although tumor-specific CD8 T lymphocytes expanded robustly after intratumoral injection of WT mice with SFV-IL12, this did not occur in mice where IFNAR was inactivated genetically or pharmacologically. Overall, our results argued that the antitumor efficacy of a virally based transgene therapeutic relied strongly on a vector-induced IFN-I response, revealing an unexpected mechanism of action that is relevant to a broad array of current translational products in cancer research. Cancer Res; 75(3); 497–507. ©2014 AACR.
Physical Activity and Survival among Men Diagnosed with Prostate Cancer
Authors: Bonn Stephanie E. , Sjölander Arvid , Lagerros Ylva Trolle , Wiklund Fredrik , Stattin Pär , Holmberg Erik , Grönberg Henrik , Bälter Katarina
Published: December 2014

Background: Few studies have investigated the association between post-diagnosis physical activity and mortality among men diagnosed with prostate cancer. The aim of this study was to investigate the effect of physical activity after a prostate cancer diagnosis on both overall and prostate cancer–specific mortality in a large cohort.

Methods: Data from 4,623 men diagnosed with localized prostate cancer 1997–2002 and followed-up until 2012 were analyzed. HRs with 95% confidence intervals (CI) were estimated using Cox proportional hazards models to examine the association between post-diagnosis recreational MET-h/d, time spent walking/bicycling, performing household work or exercising, and time to overall and prostate cancer–specific death. All models were adjusted for potential confounders.

Results: During the follow-up, 561 deaths of any cause and 194 deaths from prostate cancer occurred. Statistically significantly lower overall mortality rates were found among men engaged in ≥5 recreational MET-h/d (HR, 0.63; 95% CI, 0.52–0.77), walking/bicycling ≥20 min/d (HR, 0.70; 95% CI, 0.57–0.86), performing household work ≥1 h/d (HR, 0.71; 95% CI, 0.59–0.86), or exercising ≥1 h/wk (HR, 0.74; 95% CI, 0.61–0.90), compared with less active men within each activity type. For prostate cancer–specific mortality, statistically significantly lower mortality rates were seen among men walking/bicycling ≥20 min/d (HR, 0.61; 95% CI, 0.43–0.87) or exercising ≥1 h/wk (HR, 0.68; 95% CI, 0.48–0.94).

Conclusions: Higher levels of physical activity were associated with reduced rates of overall and prostate cancer–specific mortality.

Impact: Our study further strengthens previous results indicating beneficial effects of physical activity on survival among men with prostate cancer. Cancer Epidemiol Biomarkers Prev; 24(1); 57–64. ©2014 AACR.
Inhibition of the GTPase Rac1 Mediates the Antimigratory Effects of Metformin in Prostate Cancer Cells
Authors: Dirat Béatrice , Ader Isabelle , Golzio Muriel , Massa Fabienne , Mettouchi Amel , Laurent Kathiane , Larbret Frédéric , Malavaud Bernard , Cormont Mireille , Lemichez Emmanuel , Cuvillier Olivier , Tanti Jean François , Bost Frédéric
Published: December 2014

Cell migration is a critical step in the progression of prostate cancer to the metastatic state, the lethal form of the disease. The antidiabetic drug metformin has been shown to display antitumoral properties in prostate cancer cell and animal models; however, its role in the formation of metastases remains poorly documented. Here, we show that metformin reduces the formation of metastases to fewer solid organs in an orthotopic metastatic prostate cancer cell model established in nude mice. As predicted, metformin hampers cell motility in PC3 and DU145 prostate cancer cells and triggers a radical reorganization of the cell cytoskeleton. The small GTPase Rac1 is a master regulator of cytoskeleton organization and cell migration. We report that metformin leads to a major inhibition of Rac1 GTPase activity by interfering with some of its multiple upstream signaling pathways, namely P-Rex1 (a Guanine nucleotide exchange factor and activator of Rac1), cAMP, and CXCL12/CXCR4, resulting in decreased migration of prostate cancer cells. Importantly, overexpression of a constitutively active form of Rac1, or P-Rex, as well as the inhibition of the adenylate cyclase, was able to reverse the antimigratory effects of metformin. These results establish a novel mechanism of action for metformin and highlight its potential antimetastatic properties in prostate cancer. Mol Cancer Ther; 14(2); 586–96. ©2014 AACR.