bluuebunny/crossref_metadata_2025 huggingface dataset:
Planning Mediates Between Self-Efficacy and Physical Activity Among Motivated Young Adults
Authors: Zhou Guangyu , Wang Dongmei , Knoll Nina , Schwarzer Ralf
Published: April 2015

Background:

Often, motivation to be physically active is a necessary precondition of action but still does not suffice to initiate the target behavior. Instead, motivation needs to be translated into action by a self-regulatory process. Self-efficacy and planning are considered to be useful constructs that help to facilitate such translations.

Objective:

The aim is to examine the roles of motivation, planning, and self-efficacy as well as the mechanisms that operate in the change of physical activity levels.

Methods:

In a longitudinal observation study with 249 young adults, self-efficacy, planning, motivation, and physical activity were assessed at 2 points in time, 3 months apart.

Results:

Planning served as a mediator between self-efficacy and physical activity, controlling for baseline activity. In addition to this indirect effect, a moderator effect was found between self-efficacy and stages of change on planning. The mediation operated only in motivated, but not in unmotivated students.

Conclusions:

A mediation from self-efficacy via planning to physical activity seems to be likely only when people are motivated to become more active.
Sponsorship-Linked Marketing: Introduction to Topics
Authors: Cornwell T. Bettina , Kwak Dae Hee
Published: April 2015

Sponsorship of sport has developed over the past three decades to become a worldwide communications platform, a motivator for relationship building, and an omnipresent aspect of consumer experience for many. While it has been and continues to be a funding mechanism for sport, it is the evolution and metamorphosis of sponsorship-linked marketing that delivers endless research topics as sponsoring evolves dynamically.
Does ketamine target olfactory receptors in the brain?
Authors: Wolf Steffen , Hatt Hanns , Ernst Oliver P.
Published: April 2015

The finding that the anesthetic ketamine activates distinct olfactory receptors highlights the importance of this class of GPCRs for drug design.
Mothers tell daughters to wait for a mate
Authors: VanHook Annalisa M.
Published: April 2015

Exposure to mating pheromone drives cytoplasmic accumulation of a cell cycle inhibitor that determines whether yeast enter mitosis or wait for a mate.
Exciting nerve cells deep inside the brain
Authors: Stern Peter
Published: April 2015

A minimally invasive method allows remote neuronal excitation through the activation of a heat-sensitive receptor by magnetic nanoparticles.
A lysosomal amino acid sensor for mTORC1
Authors: VanHook Annalisa M.
Published: April 2015

Amino acid transporter SLC38A9 contributes to the amino acid sensitivity of mTORC1 activation.
Neuregulin stimulation of cardiomyocyte regeneration in mice and human myocardium reveals a therapeutic window
Authors: Polizzotti Brian D. , Ganapathy Balakrishnan , Walsh Stuart , Choudhury Sangita , Ammanamanchi Niyatie , Bennett David G. , dos Remedios Cristobal G. , Haubner Bernhard J. , Penninger Josef M. , Kühn Bernhard
Published: April 2015

The growth factor neuregulin stimulates heart muscle repair in newborn mice and heart muscle from human infants if given during a specific therapeutic time period.
A change of heart for phosphodiesterase signaling
Authors: Haldar Saptarsi M.
Published: April 2015

PDE9A is a novel myocardial phosphodiesterase that can be pharmacologically inhibited in heart disease.
Patchwork people: A role for somatic mutations in brain malformations
Authors: Mefford Heather C.
Published: April 2015

Somatic mutations in
MTOR
cause potentially treatable developmental abnormalities of the brain.
Meropenem-Clavulanic Acid Has High
In Vitro
Activity against Multidrug-Resistant Mycobacterium tuberculosis
Authors: Davies Forsman L. , Giske C. G. , Bruchfeld J. , Schön T. , Juréen P. , Ängeby K.
Published: April 2015

We investigated the activity of meropenem-clavulanic acid (MEM-CLA) against 68
Mycobacterium tuberculosis
isolates. We included predominantly multi- and extensively drug-resistant tuberculosis (MDR/XDR-TB) isolates, since the activity of MEM-CLA for resistant isolates has previously not been studied extensively. Using Middlebrook 7H10 medium, all but four isolates showed an MIC distribution of 0.125 to 2 mg/liter for MEM-CLA, below the non-species-related breakpoint for MEM of 2 mg/liter defined by EUCAST. MEM-CLA is a potential treatment option for MDR/XDR-TB.
Clinical Epidemiology and Molecular Analysis of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Nepal: Characteristics of Sequence Types 131 and 648
Authors: Sherchan Jatan Bahadur , Hayakawa Kayoko , Miyoshi-Akiyama Tohru , Ohmagari Norio , Kirikae Teruo , Nagamatsu Maki , Tojo Masayoshi , Ohara Hiroshi , Sherchand Jeevan B. , Tandukar Sarmila
Published: April 2015

Recently, CTX-M-type extended-spectrum-β-lactamase (ESBL)-producing
Escherichia coli
strains have emerged worldwide. In particular,
E. coli
with O antigen type 25 (O25) and sequence type 131 (ST131), which is often associated with the CTX-M-15 ESBL, has been increasingly reported globally; however, epidemiology reports on ESBL-producing
E. coli
in Asia are limited. Patients with clinical isolates of ESBL-producing
E. coli
in the Tribhuvan University teaching hospital in Kathmandu, Nepal, were included in this study. Whole-genome sequencing of the isolates was conducted to analyze multilocus sequence types, phylotypes, virulence genotypes, O25b-ST131 clones, and distribution of acquired drug resistance genes. During the study period, 105 patients with ESBL-producing
E. coli
isolation were identified, and the majority (90%) of these isolates were CTX-M-15 positive. The most dominant ST was ST131 (
n
= 54; 51.4%), followed by ST648 (
n
= 15; 14.3%). All ST131 isolates were identified as O25b-ST131 clones, subclone H30-Rx. Three ST groups (ST131, ST648, and non-ST131/648) were compared in further analyses. ST648 isolates had a proportionally higher resistance to non-β-lactam antibiotics and featured drug-resistant genes more frequently than ST131 or non-ST131/648 isolates. ST131 possessed the most virulence genes, followed by ST648. The clinical characteristics were similar among groups. More than 38% of ESBL-producing
E. coli
isolates were from the outpatient clinic, and pregnant patients comprised 24% of ESBL-producing
E. coli
cases. We revealed that the high resistance of ESBL-producing
E. coli
to multiple classes of antibiotics in Nepal is driven mainly by CTX-M-producing ST131 and ST648. Their immense prevalence in the communities is a matter of great concern.
In Vitro
Activity of Ceftazidime-Avibactam against 338 Molecularly Characterized Gentamicin-Nonsusceptible Gram-Negative Clinical Isolates Obtained from Patients in Canadian Hospitals
Authors: Denisuik Andrew J. , Karlowsky James A. , Denisuik Tyler , Nichols Wright W. , Keating Thomas A. , Adam Heather J. , Baxter Melanie , Walkty Andrew , Zhanel George G.
Published: April 2015

The mechanism of aminoglycoside resistance among 338 gentamicin-nonsusceptible Gram-negative bacteria (207
Enterobacteriaceae
and 131
Pseudomonas aeruginosa
) was assessed, and the
in vitro
activity of ceftazidime-avibactam against these isolates was determined. Aminoglycoside-modifying enzymes were detected in 91.8% of
Enterobacteriaceae
and 13.7% of
P. aeruginosa
isolates. A single strain of
Klebsiella pneumoniae
harbored a 16S rRNA methylase (ArmA). The ceftazidime-avibactam MIC
90
values were 0.5 μg/ml (MIC, ≤8 μg/ml for 100% of isolates) and 16 μg/ml (MIC, ≤8 μg/ml for 87.8% of isolates) against gentamicin-nonsusceptible
Enterobacteriaceae
and
P. aeruginosa
isolates, respectively.
Plasma and Epithelial Lining Fluid Pharmacokinetics of Ceftolozane and Tazobactam Alone and in Combination in Mice
Authors: Melchers M. J. , Mavridou E. , Seyedmousavi S. , van Mil A. C. , Lagarde C. , Mouton J. W.
Published: April 2015

Ceftolozane is a new cephalosporin with activity against Gram-negative and Gram-positive microorganisms. However, the compound is susceptible to degradation by extended-spectrum beta-lactamases (ESBLs). Tazobactam is an ESBL inhibitor and is combined with ceftolozane to broaden its activity. Surprisingly, although tazobactam has been available for over 20 years, few if any reliable data exist on the tazobactam pharmacokinetic (PK) properties in mice. To evaluate the PK and pharmacodynamic (PD) relationships in mice, the PK properties of tazobactam and ceftolozane were extensively investigated. Thigh-infected neutropenic CD-1 mice were injected intraperitoneally with a single 0.1-ml dose containing ceftolozane, tazobactam, or both compounds. Ceftolozane was applied in 2-fold-increasing doses of 4 mg/kg of body weight to 64 mg/kg alone or in combination. Tazobactam was combined in reverse doses (thus, 64/4 mg/kg, 32/8 mg/kg, etc.) (
n =
2 per time point). In separate validation experiments, ceftolozane-tazobactam was given alone or in combination at 32/8 mg/kg and 8/32 mg/kg (
n =
4 per time point). Plasma samples (one per mouse) and bronchoalveolar lavage samples were collected at up to 12 time points until 6 h after administration. There were no significant differences in the ceftolozane and tazobactam PK alone versus combined, indicating no PK interaction. The PKs were linear and dose proportional for both compounds and showed a good penetration in the epithelial lining fluid. The estimated mean (standard deviation) half-life of ceftolozane was 0.287 h (0.031 h), and that of tazobactam was 0.176 h (0.026), and the
V
was 0.43 liter/kg and 1.14 liter/kg, respectively. The estimates of tazobactam parameters can also be used to (re)interpret PD data.
Efficacy of Tigecycline for Secondary Acinetobacter Bacteremia and Factors Associated with Treatment Failure
Authors: Liou Bo-Huang , Lee Yi-Tzu , Kuo Shu-Chen , Liu Po-Yu , Fung Chang-Phone
Published: April 2015

We describe the clinical outcome of 17 patients with secondary
Acinetobacter
bacteremia whose isolates had a tigecycline MIC of ≤2 mg/liter and who received tigecycline within 2 days of bacteremia onset. The 14-day mortality rate of the tigecycline cohort was 41.2% (7/17), which was significantly higher than that of those receiving other appropriate antimicrobial agents (13.8%, 9/65;
P
= 0.018). However, the percentages of end-stage renal disease and congestive heart failure were higher in the tigecycline cohort. The efficacy of tigecycline was contingent upon the illness severity and bacterial species. Tigecycline should be applied cautiously for treatment of
Acinetobacter
bacteremia.
Azole Drug Import into the Pathogenic Fungus Aspergillus fumigatus
Authors: Esquivel Brooke D. , Smith Adam R. , Zavrel Martin , White Theodore C.
Published: April 2015

The fungal pathogen
Aspergillus fumigatus
causes serious illness and often death when it invades tissues, especially in immunocompromised individuals. The azole class of drugs is the most commonly prescribed treatment for many fungal infections and acts on the ergosterol biosynthesis pathway. One common mechanism of acquired azole drug resistance in fungi is the prevention of drug accumulation to toxic levels in the cell. While drug efflux is a well-known resistance strategy, reduced azole import would be another strategy to maintain low intracellular azole levels. Recently, azole uptake in
Candida albicans
and other yeasts was analyzed using [
3
H]fluconazole. Defective drug import was suggested to be a potential mechanism of drug resistance in several pathogenic fungi, including
Cryptococcus neoformans
,
Candida krusei
, and
Saccharomyces cerevisiae
. We have adapted and developed an assay to measure azole accumulation in
A. fumigatus
using radioactively labeled azole drugs, based on previous work done with
C. albicans
. We used this assay to study the differences in azole uptake in
A. fumigatus
isolates under a variety of drug treatment conditions, with different morphologies and with a select mutant strain with deficiencies in the sterol uptake and biosynthesis pathway. We conclude that azole drugs are specifically selected and imported into the fungal cell by a pH- and ATP-independent facilitated diffusion mechanism, not by passive diffusion. This method of drug transport is likely to be conserved across most fungal species.
Novel Dosing Strategies Increase Exposures of the Potent Antituberculosis Drug Rifapentine but Are Poorly Tolerated in Healthy Volunteers
Authors: Dooley Kelly E. , Savic Radojka M. , Park Jeong-Gun , Cramer Yoninah , Hafner Richard , Hogg Evelyn , Janik Jennifer , Marzinke Mark A. , Patterson Kristine , Benson Constance A. , Hovind Laura , Dorman Susan E. , Haas David W. ,   ACTG A5311 Study Team
Published: April 2015

Rifapentine is a potent antituberculosis drug currently in phase III trials. Bioavailability decreases with increasing dose, yet high daily exposures are likely needed to improve efficacy and shorten the tuberculosis treatment duration. Further, the limits of tolerability are poorly defined. The phase I multicenter trial in healthy adults described here investigated two strategies to increase rifapentine exposures: dividing the dose or giving the drug with a high-fat meal. In arm 1, rifapentine was administered at 10 mg/kg of body weight twice daily and 20 mg/kg once daily, each for 14 days, separated by a 28-day washout; the dosing sequence was randomized. In arm 2, 15 mg/kg rifapentine once daily was given with a high-fat versus a low-fat breakfast. Sampling for pharmacokinetic analysis was performed on days 1 and 14. Population pharmacokinetic analyses were performed. This trial was stopped early for poor tolerability and because of safety concerns. Of 44 subjects, 20 discontinued prematurely; 11 of these discontinued for protocol-defined toxicity (a grade 3 or higher adverse event or grade 2 or higher rifamycin hypersensitivity). Taking rifapentine with a high-fat meal increased the median steady-state area under the concentration-time curve from time zero to 24 h (AUC
0–24ss
) by 31% (relative standard error, 6%) compared to that obtained when the drug was taken with a low-fat breakfast. Dividing the dose increased exposures substantially (e.g., 38% with 1,500 mg/day). AUC
0–24ss
was uniformly higher in our study than in recent tuberculosis treatment trials, in which toxicity was rare. In conclusion, two strategies to increase rifapentine exposures, dividing the dose or giving it with a high-fat breakfast, successfully increased exposures, but toxicity was common in healthy adults. The limits of tolerability in patients with tuberculosis remain to be defined. (AIDS Clinical Trials Group study A5311 has been registered at ClinicalTrials.gov under registration no. NCT01574638.)
Inhibition of Outer Membrane Proteases of the Omptin Family by Aprotinin
Authors: Brannon John R. , Burk David L. , Leclerc Jean-Mathieu , Thomassin Jenny-Lee , Portt Andrea , Berghuis Albert M. , Gruenheid Samantha , Le Moual Hervé
Published: April 2015

Bacterial proteases are important virulence factors that inactivate host defense proteins and contribute to tissue destruction and bacterial dissemination. Outer membrane proteases of the omptin family, exemplified by
Escherichia coli
OmpT, are found in some Gram-negative bacteria. Omptins cleave a variety of substrates at the host-pathogen interface, including plasminogen and antimicrobial peptides. Multiple omptin substrates relevant to infection have been identified; nonetheless, an effective omptin inhibitor remains to be found. Here, we purified native CroP, the OmpT ortholog in the murine pathogen
Citrobacter rodentium
. Purified CroP was found to readily cleave both a synthetic fluorescence resonance energy transfer substrate and the murine cathelicidin-related antimicrobial peptide. In contrast, CroP was found to poorly activate plasminogen into active plasmin. Although classical protease inhibitors were ineffective against CroP activity, we found that the serine protease inhibitor aprotinin displays inhibitory potency in the micromolar range. Aprotinin was shown to act as a competitive inhibitor of CroP activity and to interfere with the cleavage of the murine cathelicidin-related antimicrobial peptide. Importantly, aprotinin was able to inhibit not only CroP but also
Yersinia pestis
Pla and, to a lesser extent,
E. coli
OmpT. We propose a structural model of the aprotinin-omptin complex in which Lys
15
of aprotinin forms salt bridges with conserved negatively charged residues of the omptin active site.
Chlamydia muridarum Induction of Glandular Duct Dilation in Mice
Authors: Sun Xin , Yang Zhangsheng , Zhang Hongbo , Dai Jin , Chen Jianlin , Tang Lingli , Rippentrop Sheena , Xue Min , Zhong Guangming , Wu Ganqiu
Published: April 2015

Although
Chlamydia
-induced hydrosalpinx in women and mice has been used as a surrogate marker for tubal infertility, the medical relevance of nontubal pathologies, such as uterine horn dilation, developed in mice following chlamydial infection remains unclear. We now report that the uterine horn dilation correlates with glandular duct dilation detected microscopically following
Chlamydia muridarum
infection. The dilated glandular ducts pushed the uterine horn lumen to closure or dilation and even broke through the myometrium to develop extrusion outside the uterine horn. The severity scores of uterine horn dilation observed macroscopically correlated well with the number of cross sections of the dilated glandular ducts counted under microscopy. Chlamydial infection was detected in the glandular epithelial cells, potentially leading to inflammation and dilation of the glandular ducts. Direct delivery of
C. muridarum
into the mouse uterus increased both uterine horn/glandular duct dilation and hydrosalpinx. However, the chlamydial plasmid, which is essential for the induction of hydrosalpinx, was not required for the induction of uterine horn/glandular duct dilation. Screening 12 strains of mice for uterine horn dilation following
C. muridarum
infection revealed that B10.D2, C57BL/10J, and C57BL/6J mice were most susceptible, followed by BALB/cJ and A/J mice. Deficiency in host genes involved in immune responses failed to significantly alter the
C. muridarum
induction of uterine horn dilation. Nevertheless, the chlamydial induction of uterine horn/glandular duct dilation may be used to evaluate plasmid-independent pathogenicity of
Chlamydia
in susceptible mice.
Staphylococcus aureus MnhF Mediates Cholate Efflux and Facilitates Survival under Human Colonic Conditions
Authors: Sannasiddappa Thippeswamy H. , Hood Graham A. , Hanson Kevan J. , Costabile Adele , Gibson Glenn R. , Clarke Simon R.
Published: April 2015

Resistance to the innate defenses of the intestine is crucial for the survival and carriage of
Staphylococcus aureus
, a common colonizer of the human gut. Bile salts produced by the liver and secreted into the intestines are one such group of molecules with potent antimicrobial activity. The mechanisms by which
S. aureus
is able to resist such defenses in order to colonize and survive in the human gut are unknown. Here we show that
mnhF
confers resistance to bile salts, which can be abrogated by efflux pump inhibitors. MnhF mediates the efflux of radiolabeled cholic acid both in
S. aureus
and when heterologously expressed in
Escherichia coli
, rendering them resistant. Deletion of
mnhF
attenuated the survival of
S. aureus
in an anaerobic three-stage continuous-culture model of the human colon (gut model), which represents different anatomical areas of the large intestine.
Analysis of the Effects of Cigarette Smoke on Staphylococcal Virulence Phenotypes
Authors: McEachern Elisa K. , Hwang John H. , Sladewski Katherine M. , Nicatia Shari , Dewitz Carola , Mathew Denzil P. , Nizet Victor , Crotty Alexander Laura E.
Published: April 2015

Cigarette smoking is the leading preventable cause of death, disease, and disability worldwide. It is well established that cigarette smoke provokes inflammatory activation and impairs antimicrobial functions of human immune cells. Here we explore whether cigarette smoke likewise affects the virulence properties of an important human pathogen,
Staphylococcus aureus
, and in particular methicillin-resistant
S. aureus
(MRSA), one of the leading causes of invasive bacterial infections. MRSA colonizes the nasopharynx and is thus exposed to inhalants, including cigarette smoke. MRSA exposed to cigarette smoke extract (CSE-MRSA) was more resistant to macrophage killing (4-fold higher survival;
P
< 0.0001). CSE-MRSA demonstrated reduced susceptibility to cell lysis (1.78-fold;
P
= 0.032) and antimicrobial peptide (AMP) (LL-37) killing (MIC, 8 μM versus 4 μM). CSE modified the surface charge of MRSA in a dose-dependent fashion, impairing the binding of particles with charge similar to that of AMPs by 90% (
P
< 0.0001). These changes persisted for 24 h postexposure, suggesting heritable modifications. CSE exposure increased hydrophobicity by 55% (
P
< 0.0001), which complemented findings of increased MRSA adherence and invasion of epithelial cells. CSE induced upregulation of
mprF
, consistent with increased MRSA AMP resistance.
S. aureus
without
mprF
had no change in surface charge upon exposure to CSE.
In vivo
, CSE-MRSA pneumonia induced higher mouse mortality (40% versus 10%) and increased bacterial burden at 8 and 20 h postinfection compared to control MRSA-infected mice (
P
< 0.01). We conclude that cigarette smoke-induced immune resistance phenotypes in MRSA may be an additional factor contributing to susceptibility to infectious disease in cigarette smokers.
Listeria monocytogenes Spreads within the Brain by Actin-Based Intra-Axonal Migration
Authors: Henke Diana , Rupp Sebastian , Gaschen Véronique , Stoffel Michael H. , Frey Joachim , Vandevelde Marc , Oevermann Anna
Published: April 2015

Listeria monocytogenes
rhombencephalitis is a severe progressive disease despite a swift intrathecal immune response. Based on previous observations, we hypothesized that the disease progresses by intra-axonal spread within the central nervous system. To test this hypothesis, neuroanatomical mapping of lesions, immunofluorescence analysis, and electron microscopy were performed on brains of ruminants with naturally occurring rhombencephalitis. In addition, infection assays were performed in bovine brain cell cultures. Mapping of lesions revealed a consistent pattern with a preferential affection of certain nuclear areas and white matter tracts, indicating that
Listeria monocytogenes
spreads intra-axonally within the brain along interneuronal connections. These results were supported by immunofluorescence and ultrastructural data localizing
Listeria monocytogenes
inside axons and dendrites associated with networks of fibrillary structures consistent with actin tails.
In vitro
infection assays confirmed that bacteria were moving within axon-like processes by employing their actin tail machinery. Remarkably,
in vivo
, neutrophils invaded the axonal space and the axon itself, apparently by moving between split myelin lamellae of intact myelin sheaths. This intra-axonal invasion of neutrophils was associated with various stages of axonal degeneration and bacterial phagocytosis. Paradoxically, the ensuing adaxonal microabscesses appeared to provide new bacterial replication sites, thus supporting further bacterial spread. In conclusion, intra-axonal bacterial migration and possibly also the innate immune response play an important role in the intracerebral spread of the agent and hence the progression of listeric rhombencephalitis.
Oxygen-Dependent Cell-to-Cell Variability in the Output of the Escherichia coli Tor Phosphorelay
Authors: Roggiani Manuela , Goulian Mark
Published: April 2015

Escherichia coli
senses and responds to trimethylamine-
N
-oxide (TMAO) in the environment through the TorT-TorS-TorR signal transduction system. The periplasmic protein TorT binds TMAO and stimulates the hybrid kinase TorS to phosphorylate the response regulator TorR through a phosphorelay. Phosphorylated TorR, in turn, activates transcription of the
torCAD
operon, which encodes the proteins required for anaerobic respiration via reduction of TMAO to trimethylamine. Interestingly,
E. coli
respires TMAO in both the presence and absence of oxygen, a behavior that is markedly different from the utilization of other alternative electron acceptors by this bacterium. Here we describe an unusual form of regulation by oxygen for this system. While the average level of
torCAD
transcription is the same for aerobic and anaerobic cultures containing TMAO, the behavior across the population of cells is strikingly different under the two growth conditions. Cellular levels of
torCAD
transcription in aerobic cultures are highly heterogeneous, in contrast to the relatively homogeneous distribution in anaerobic cultures. Thus, oxygen regulates the variance of the output but not the mean for the Tor system. We further show that this oxygen-dependent variability stems from the phosphorelay.

IMPORTANCE
Trimethylamine-
N
-oxide (TMAO) is utilized by numerous bacteria as an electron acceptor for anaerobic respiration. In
E. coli
, expression of the proteins required for TMAO respiration is tightly regulated by a signal transduction system that is activated by TMAO. Curiously, although oxygen is the energetically preferred electron acceptor, TMAO is respired even in the presence of oxygen. Here we describe an interesting and unexpected form of regulation for this system in which oxygen produces highly variable expression of the TMAO utilization proteins across a population of cells without affecting the mean expression of these proteins. To our knowledge, this is the first reported example of a stimulus regulating the variance but not the mean output of a signaling system.
RNase III-Independent Autogenous Regulation of Escherichia coli Polynucleotide Phosphorylase via Translational Repression
Authors: Carzaniga Thomas , Dehò Gianni , Briani Federica
Published: April 2015

The complex posttranscriptional regulation mechanism of the
Escherichia coli
pnp
gene, which encodes the phosphorolytic exoribonuclease polynucleotide phosphorylase (PNPase), involves two endoribonucleases, namely, RNase III and RNase E, and PNPase itself, which thus autoregulates its own expression. The models proposed for
pnp
autoregulation posit that the target of PNPase is a mature
pnp
mRNA previously processed at its 5′ end by RNase III, rather than the primary
pnp
transcript (RNase III-dependent models), and that PNPase activity eventually leads to
pnp
mRNA degradation by RNase E. However, some published data suggest that
pnp
expression may also be regulated through a PNPase-dependent, RNase III-independent mechanism. To address this issue, we constructed isogenic Δ
pnp rnc
+
and Δ
pnp
Δ
rnc
strains with a chromosomal
pnp-lacZ
translational fusion and measured β-galactosidase activity in the absence and presence of PNPase expressed by a plasmid. Our results show that PNPase also regulates its own expression via a reversible RNase III-independent pathway acting upstream from the RNase III-dependent branch. This pathway requires the PNPase RNA binding domains KH and S1 but not its phosphorolytic activity. We suggest that the RNase III-independent autoregulation of PNPase occurs at the level of translational repression, possibly by competition for
pnp
primary transcript between PNPase and the ribosomal protein S1.

IMPORTANCE
In
Escherichia coli
, polynucleotide phosphorylase (PNPase, encoded by
pnp
) posttranscriptionally regulates its own expression. The two models proposed so far posit a two-step mechanism in which RNase III, by cutting the leader region of the
pnp
primary transcript, creates the substrate for PNPase regulatory activity, eventually leading to
pnp
mRNA degradation by RNase E. In this work, we provide evidence supporting an additional pathway for PNPase autogenous regulation in which PNPase acts as a translational repressor independently of RNase III cleavage. Our data make a new contribution to the understanding of the regulatory mechanism of
pnp
mRNA, a process long since considered a paradigmatic example of posttranscriptional regulation at the level of mRNA stability.
The Matrix Reloaded: How Sensing the Extracellular Matrix Synchronizes Bacterial Communities
Authors: Steinberg Nitai , Kolodkin-Gal Ilana
Published: April 2015

In response to chemical communication, bacterial cells often organize themselves into complex multicellular communities that carry out specialized tasks. These communities are frequently referred to as biofilms, which involve the collective behavior of different cell types. Like cells of multicellular eukaryotes, the biofilm cells are surrounded by self-produced polymers that constitute the extracellular matrix (ECM), which binds them to each other and to the surface. In multicellular eukaryotes, it has been evident for decades that cell-ECM interactions control multiple cellular processes during development. While cells both in biofilms and in multicellular eukaryotes are surrounded by ECM and activate various genetic programs, until recently it has been unclear whether cell-ECM interactions are recruited in bacterial communicative behaviors. In this review, we describe the examples reported thus far for ECM involvement in control of cell behavior throughout the different stages of biofilm formation. The studies presented in this review have provided a newly emerging perspective of the bacterial ECM as an active player in regulation of biofilm development.
Abbreviated Pathway for Biosynthesis of 2-Thiouridine in Bacillus subtilis
Authors: Black Katherine A. , Dos Santos Patricia C.
Published: April 2015

The 2-thiouridine (s2U) modification of the wobble position in glutamate, glutamine, and lysine tRNA molecules serves to stabilize the anticodon structure, improving ribosomal binding and overall efficiency of the translational process. Biosynthesis of s2U inEscherichia colirequires a cysteine desulfurase (IscS), a thiouridylase (MnmA), and five intermediate sulfur-relay enzymes (TusABCDE). TheE. coliMnmA adenylates and subsequently thiolates tRNA to form the s2U modification.Bacillus subtilislacks IscS and the intermediate sulfur relay proteins, yet its genome contains a cysteine desulfurase gene,yrvO, directly adjacent tomnmA. The genomic synteny ofyrvOandmnmAcombined with the absence of the Tus proteins indicated a potential functionality of these proteins in s2U formation. Here, we provide evidence that theB. subtilisYrvO and MnmA are sufficient for s2U biosynthesis. A conditionalB. subtilisknockout strain showed that s2U abundance correlates with MnmA expression, andin vivocomplementation studies inE. coliIscS- or MnmA-deficient strains revealed the competency of these proteins in s2U biosynthesis.In vitroexperiments demonstrated s2U formation by YrvO and MnmA, and kinetic analysis established a partnership between theB. subtilisproteins that is contingent upon the presence of ATP. Furthermore, we observed that the slow-growth phenotype ofE. coliΔiscSand ΔmnmAstrains associated with s2U depletion is recovered byB. subtilis yrvOandmnmA. These results support the proposal that the involvement of a devoted cysteine desulfurase, YrvO, in s2U synthesis bypasses the need for a complex biosynthetic pathway by direct sulfur transfer to MnmA.

IMPORTANCEThe 2-thiouridine (s2U) modification of the wobble position in glutamate, glutamine, and lysine tRNA is conserved in all three domains of life and stabilizes the anticodon structure, thus guaranteeing fidelity in translation. The biosynthesis of s2U inEscherichia colirequires seven proteins: the cysteine desulfurase IscS, the thiouridylase MnmA, and five intermediate sulfur-relay enzymes (TusABCDE).Bacillus subtilisand most Gram-positive bacteria lack a complete set of biosynthetic components. Interestingly, themnmAcoding sequence is located adjacent toyrvO, encoding a cysteine desulfurase. In this work, we provide evidence that theB. subtilisYrvO is able to transfer sulfur directly to MnmA. Both proteins are sufficient for s2U biosynthesis in a pathway independent of the one used inE. coli.
Targeted Knockout of the Rickettsia rickettsii OmpA Surface Antigen Does Not Diminish Virulence in a Mammalian Model System
Authors: Noriea Nicholas F. , Clark Tina R. , Hackstadt Ted
Published: April 2015

Strains of
Rickettsia rickettsii
, the causative agent of Rocky Mountain spotted fever (RMSF), differ dramatically in virulence despite >99% genetic homology. Spotted fever group (SFG) rickettsiae produce two immunodominant outer membrane proteins, rickettsial OmpA (rOmpA) and rOmpB, which are conserved throughout the SFG and thought to be fundamental to pathogenesis. rOmpA is present in all virulent strains of
R. rickettsii
but is not produced in the only documented avirulent strain, Iowa, due to a premature stop codon. Here we report the creation of an isogenic
ompA
mutant in the highly virulent strain Sheila Smith by insertion of intronic RNA to create a premature stop codon 312 bp downstream of the 6,747-bp open reading frame initiation site (int312). Targeted insertion was accomplished using an LtrA group II intron retrohoming system. Growth and entry rates of Sheila Smith
ompA
::int312 in Vero cells remained comparable to those of the wild type. Virulence was assessed in a guinea pig model by challenge with 100 PFU of either
ompA
::int312 Sheila Smith or the wild type, but no significant difference in either fever peak (40.5°C) or duration (8 days) were shown between the wild type and the knockout. The ability to disrupt genes in a site-specific manner using an LtrA group II intron system provides an important new tool for evaluation of potential virulence determinants in rickettsial disease research.

IMPORTANCE
R. rickettsii
rOmpA is an immunodominant outer membrane autotransporter conserved in the spotted fever group. Previous studies and genomic comparisons suggest that rOmpA is involved in adhesion and may be critical for virulence. Little information is available for rickettsial virulence factors in an isogenic background, as limited systems for targeted gene disruption are currently available. Here we describe the creation of an rOmpA knockout by insertion of a premature stop codon into the 5′ end of the open reading frame using a group II intron system. An isogenic rOmpA knockout mutation in the highly virulent Sheila Smith strain did not cause attenuation in a guinea pig model of infection, and no altered phenotype was observed in cell culture. We conclude that rOmpA is not critical for virulence in a guinea pig model but may play a role in survival or transmission from the tick vector.
Effectiveness of Acupuncture Combined with Rehabilitation for Treatment of Acute Or Subacute Stroke: A Systematic Review
Authors: Vados Larissa , Ferreira Alberto , Zhao ShouFa , Vercelino Rafael , Wang Shu
Published: April 2015

Objectives

To determine whether the combination of acupuncture and rehabilitation produces better results in the treatment of acute or subacute stroke sequelae than rehabilitation alone.

Methods

A systematic review was carried out. A search was conducted in March 2014 using PubMed, Medline, the Cochrane Library, Chinese National Knowledge Infrastructure database (CNKI) and Wanfang databases. English and Chinese language articles published within 10 years of the search were reviewed for inclusion. Randomised control trials comparing combined treatment with acupuncture and rehabilitation and rehabilitation alone in patients with acute or subacute stroke (onset until 3 months after stroke) were included in this review. Three review authors independently checked the titles and abstracts of trials for inclusion based on selection criteria. Studies measuring changes of motor function, activities of daily living, neurological deficit or spasticity/range of motion during the treatment period and at the end of follow-up were included.

Results

17 trials met the inclusion criteria, of which five were of good quality. 14 trials had results favourable to acupuncture combined with rehabilitation, compared with conventional rehabilitation treatment alone.

Conclusions

Acupuncture in combination with rehabilitation may have benefits for the treatment of acute and subacute stroke sequelae in comparison with rehabilitation alone. However, many of the studies were at risk of bias. Future studies should focus on reaching a consensus about the most appropriate modality of acupuncture intervention, and the appropriate length of treatment for both interventions, to maximise the potential synergistic outcomes.
Mycotic pseudoaneurysm by vancomycin-intermediateStaphylococcus aureus: a rare cause of persistent bacteraemia
Authors: Mahfood Haddad Toufik , Vallabhajosyula Saraschandra , Sundaragiri Pranathi Rao , Vivekanandan Renuga
Published: April 2015

Pseudoaneurysms are vessel wall ruptures, that are often mistaken for deep vein thrombosis (DVT). A middle-aged man presented with right leg pain, swelling and erythema. His history was significant for persistentStaphylococcus aureusbacteraemia. Ultrasound revealed subacute DVT and laboratory parameters were suggestive of sepsis. He was started on intravenous heparin and antimicrobials. Owing to persistent anaemia despite blood transfusion, MRI of the right thigh was obtained. It revealed a 13×17 cm superficial femoral artery infected mycotic pseudoaneurysm (MPA) with a fresh haematoma. The patient underwent arterial ligation and extensive debridement. Intraoperative cultures revealed daptomycin-resistant vancomycin-intermediateS. aureus(VISA) and he was managed with 6 weeks of intravenous ceftaroline. MPAs are most common in the femoral artery and form <1% of aneurysms. Therapy involves surgical debridement and prolonged antimicrobials. VISA causing MPA is associated with worse outcomes. We report the first time use of ceftaroline in the management of a VISA MPA.
A 54-year-old woman with premature ventricular complexes and a rapidly changing ECG
Authors: Bencharif Sarah , Leung Lawrence
Published: April 2015

Premature ventricular complexes (PVCs) are common findings in asymptomatic participants during ECG recordings. While most PVCs are treated conservatively, some patients may develop adverse cardiac events needing further investigations and definitive ablation by radiofrequency. Spectral strain ultrasonography has demonstrated ventricular dysfunction as a sequel to high burden PVCs, but the exact underlying pathophysiology is still uncertain. Cohort studies have associated PVCs with increased risks for overall cardiovascular morbidity and mortality, and yet consensus is still lacking for threshold in treating PVCs. Our case is that of a 54-year-old woman with an unusual bradycardiac presentation of PVCs and an ECG that changed rapidly within minutes.
Pain reduction in patients after applying a nitrous oxide/oxygen mixture (Livopan) during photodynamic therapy: study protocol for an observational study (Livopan study)
Authors: Gholam Patrick , Fink Christine , Uhlmann Lorenz , Enk Alexander
Published: April 2015

Introduction

Photodynamic therapy (PDT) is an effective treatment option for extensively photodamaged skin with multiple actinic kerastosis. However, the main drawback of PDT is the intensive pain experienced during its application, which makes it frequently necessary to interrupt or even terminate the process resulting in incomplete treatment. Several strategies for controlling pain during PDT have been studied but few effective methods are currently available. Alternative options are urgently needed. Livopan, a nitrous oxide/oxygen mixture, is indicated for the treatment of short-term pain conditions when rapid analgesic onset and offset effects are wanted. But so far, there are no studies evaluating the effect of Livopan on pain intensity during PDT. Therefore, it remains unclear whether patients benefit from this inhalation analgesia. Within the Livopan study, this issue will be evaluated for the first time.

Methods and analysis

The Livopan study is a prospective, single-centre, explorative, controlled, observational study to investigate the pain reduction in patients after applying a nitrous oxide/oxygen mixture (Livopan) during PDT according to the visual analogue scale in 60 patients.

Ethics and dissemination

Ethics approval was provided by the ethics committee of the medical faculty of the University of Heidelberg. Ethics approval number S-169/2014.

Trial registration number

German Clinical Trial Register (DRKS): DRKS00006054.
Palliative care patients’ perceptions of the work involved in understanding and managing the network of care provision surrounding them
Authors: Jarrett N , Porter K , Davis C , Lathlean J , Duke S , Corner J , Addington-Hall J
Published: April 2015

Objective

To explore the work carried out for cancer palliative care patients in understanding and dealing with the often large network of care provision surrounding them.

Method

Qualitative thematic analysis of interviews with 24 patients (aged 48–85 years) with 15 different types/sites of cancer and palliative care needs.

Results

The main theme of ‘patient work—their strategies and project management’ is presented. Subthemes included: being organised and keeping records; planning ahead and coordinating care; information gathering; understanding the hierarchy and knowing who the key people are; strategies to remember names and roles; understanding and ‘working the system’. Insights are given into the work carried out on patients’ behalf by family, although it was unclear who would do this work if no family was available. Some of the challenges faced by patients and families are identified. These included limited information; uncertainty when care is transferred between different teams or locations; deciding who to contact and how; and negotiating through gatekeepers.

Conclusions

The number and variety of people contributing to the care of a cancer palliative care patient can be difficult for patients and family to comprehend. Work is required by patients or family on their behalf to achieve the level of understanding required to become accomplished at navigating the system and project managing their care organisation, and is probably influenced by role expectations and previous experience. Much of this additional, often hidden, workload for patients and family could probably be reduced with clear, timely information provision by health professionals.
Why is it so difficult to recruit patients to research in emergency care? Lessons from the AHEAD study
Authors: Johnson Rowena , Kuczawski Maxine , Mason Suzanne
Published: April 2015

Introduction

In February 2014, all 23 National Institute for Health Research medical research specialities were failing to meet recruitment targets, with ‘Injuries and Emergencies’ research performing particularly poorly. In this paper, the multicentre AHEAD study was used to explore issues surrounding recruitment in UK emergency departments.

Method

The AHEAD study investigated management and outcomes in over 3000 anticoagulated patients who suffered a head injury. Data from the study were used to compare patient recruitment at 33 Type-1 emergency departments. A questionnaire was sent to a research nurse at each of these sites and 30 replied (91% response rate). The survey investigated the difficulties encountered during patient recruitment and whether these were related to recruitment methods. More detailed interviews were conducted with three research nurses, to gain further insight into the barriers and facilitators involved.

Results

Overall recruitment varied widely between sites with an eightfold variation in recruitment rates. Population demographics and other uncontrollable factors will partly contribute to this variation. However, research nurses reported many problems, including site resources, lack of staff engagement and flaws in recruitment strategies, which could be improved.

Conclusions

Many of the barriers to recruiting patients for research studies encountered by research nurses have previously been reported in the literature, but there remain consistent problems. Until solutions are found, researchers will continue to miss recruitment targets and this will have implications for the efficiency and quality of emergency medicine research in the UK.
Bone marrow aspiration in resource poor environment: our experience in Kenya
Authors: Busarla Satya Vara Prasad
Published: April 2015

Bone marrow aspiration examination is performed mainly to evaluate haematological disorders. Several bone marrow aspiration needles are available that include the Salah, Klima, Jamshidi and Islam. However, cost is an issue in our local environment as most of our patients are not medically insured. We describe our experience of bone marrow aspiration using an 18-gauge lumbar puncture needle at the posterior superior iliac spine. The technique is safe and cost effective and the site is easily accessible, even in obese patients. The crush preparations provide good morphology, therefore avoiding repeats. Additional training is not required for the procedural technique. We recommend this technique for use in resource challenged settings.
Differentiating primary and extragenital metastatic mucinous ovarian tumours: an algorithm combining PAX8 with tumour size and laterality
Authors: Hu Ajin , Li Hongwei , Zhang Letian , Ren Caixia , Wang Yuxiang , Liu Yan , Liu Congrong
Published: April 2015

Aims

Our aim was to analyse the utility of the algorithm combining PAX8 with clinicopathological characteristics (tumour size, laterality and patient age) in differentiating primary ovarian mucinous tumours (POMTs) from extragenital metastatic mucinous carcinomas involving the ovary (eMOMCs).

Methods and results

Immunohistochemical staining for PAX8 was performed on formalin ﬁxed, parafﬁn embedded tissues from 47 POMTs, 18 eMOMCs and 70 extragenital primary mucinous carcinomas (ePMCs) using anti-PAX8 rabbit polyclonal antibody (pAb) and anti-PAX8 rabbit monoclonal antibody (mAb). PAX8 (pAb) positive signals were found in 3/18 eMOMCs and in 32/70 ePMCs. PAX8 (mAb) demonstrated superior specificity, with 0% positivity in both eMOMCs and ePMCs, but unfavourable sensitivity, with 60.9% in ovarian mucinous borderline tumours and 45.8% in POMCs. Although PAX8 (mAb) immunostaining status (66.2%), tumour size (75.4%) and laterality (84.6%) demonstrated unsatisfactory accuracy when they were evaluated individually in differentiating POMTs from eMOMCs, a combination of PAX8 (mAb) immunostaining status, tumour size and laterality markedly increased accuracy (86.2%), with a satisfactory Youden Index (63.7%).

Conclusions

PAX8 (mAb) was a specific marker in differentiating POMTs from eMOMCs. As a simple, convenient and high performance to price ratio algorithm, a combination of PAX8 (mAb) immunostaining with tumour size and laterality will improve the diagnostic criteria of ovarian mucinous metastasis.