bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complete Sequence of pOZ176, a 500-Kilobase IncP-2 Plasmid Encoding IMP-9-Mediated Carbapenem Resistance, from Outbreak Isolate Pseudomonas aeruginosa 96
Authors: Xiong Jianhui , Alexander David C. , Ma Jennifer H. , Déraspe Maxime , Low Donald E. , Jamieson Frances B. , Roy Paul H. 
Published: May 2013

ABSTRACT

Pseudomonas aeruginosa
96 (PA96) was isolated during a multicenter surveillance study in Guangzhou, China, in 2000. Whole-genome sequencing of this outbreak strain facilitated analysis of its IncP-2 carbapenem-resistant plasmid, pOZ176. The plasmid had a length of 500,839 bp and an average percent G+C content of 57%. Of the 618 predicted open reading frames, 65% encode hypothetical proteins. The pOZ176 backbone is not closely related to any plasmids thus far sequenced, but some similarity to pQBR103 of
Pseudomonas fluorescens
SBW25 was observed. Two multiresistant class 1 integrons and several insertion sequences were identified. The
bla
IMP-9
-carrying integron contained
aacA4
→
bla
IMP-9
→
aacA4
, flanked upstream by Tn
21 tnpMRA
and downstream by a complete
tni
operon of Tn
402
and a
mer
module, named Tn
6016
. The second integron carried
aacA4
→
catB8a
→
bla
OXA-10
and was flanked by Tn
1403
-like
tnpRA
and a
sul1
-type 3′ conserved sequence (3′-CS), named Tn
6217
. Other features include three resistance genes similar to those of Tn
5
, a tellurite resistance operon, and two
pil
operons. The replication and maintenance systems exhibit similarity to a genomic island of
Ralstonia solanacearum
GM1000. Codon usage analysis suggests the recent acquisition of
bla
IMP-9
. The origins of the integrons on pOZ176 indicated separate horizontal gene transfer events driven by antibiotic selection. The novel mosaic structure of pOZ176 suggests that it is derived from environmental bacteria.
Post-PKS Tailoring Steps of the Spiramycin Macrolactone Ring in Streptomyces ambofaciens
Authors: Nguyen Hoang-Chuong , Darbon Emmanuelle , Thai Robert , Pernodet Jean-Luc , Lautru Sylvie 
Published: May 2013

ABSTRACT

Spiramycins are clinically important 16-member macrolide antibiotics produced by
Streptomyces ambofaciens
. Biosynthetic studies have established that the earliest lactonic intermediate in spiramycin biosynthesis, the macrolactone platenolide I, is synthesized by a type I modular polyketide synthase (PKS). Platenolide I then undergoes a series of post-PKS tailoring reactions yielding the final products, spiramycins I, II, and III. We recently characterized the post-PKS glycosylation steps of spiramycin biosynthesis in
S. ambofaciens
. We showed that three glycosyltransferases, Srm5, Srm29, and Srm38, catalyze the successive attachment of the three carbohydrates mycaminose, forosamine, and mycarose, respectively, with the help of two auxiliary proteins, Srm6 and Srm28. However, the enzymes responsible for the other tailoring steps, namely, the C-19 methyl group oxidation, the C-9 keto group reduction, and the C-3 hydroxyl group acylation, as well as the timing of the post-PKS tailoring reactions, remained to be established. In this study, we show that Srm13, a cytochrome P450, catalyzes the oxidation of the C-19 methyl group into a formyl group and that Srm26 catalyzes the reduction of the C-9 keto group, and we propose a timeline for spiramycin-biosynthetic post-PKS tailoring reactions.
Theaflavin-3,3′-Digallate and Lactic Acid Combinations Reduce Herpes Simplex Virus Infectivity
Authors: Isaacs Charles E. , Xu Weimin 
Published: May 2013

ABSTRACT

The present study examined the efficacy of using multiple mechanisms as part of a topical microbicide to inactivate herpes simplex virus (HSV) by combining theaflavin-3,3′-digallate (TF-3) and lactic acid (LA) over the pH range of 4.0 to 5.7 to mimic conditions in the female reproductive tract. Six clinical isolates of HSV-2 and two clinical isolates of HSV-1 were almost completely inactivated when TF-3 (100 μM) was present with LA over the pH range of 4.5 to 5.7, whereas four additional HSV-1 clinical isolates required TF-3 concentrations of 250 to 500 μM for comparable virus titer reduction. LA (1%) alone at pH 4.0 reduced the titers of laboratory and clinical isolates of HSV-1 and HSV-2 by ≥5 log
10
, but most LA-dependent antiviral activity was lost at a pH of ≥4.5. When HSV-1 and HSV-2 were incubated at pH 4.0 without LA virus titers were not reduced. At pH 4.0, HSV-1 and HSV-2 titers were reduced 5 log
10
in 20 min by LA alone. TF-3 reduced HSV-2 titers by 5 log
10
in 20 to 30 min at pH 4.5, whereas HSV-1 required 60 min for comparable inactivation. Mixtures of TF-3 and LA stored at 37°C for 1 month at pH 4.0 to 5.7 maintained antiviral activity. Semen, but not cervical vaginal fluid, decreased LA-dependent antiviral activity at pH 4.0, but adding TF-3 to the mixture reduced HSV titers by 4 to 5 log
10
. These results indicate that a combination microbicide containing TF-3 and LA could reduce HSV transmission.
The Fur-Iron Complex Modulates Expression of the Quorum-Sensing Master Regulator, SmcR, To Control Expression of Virulence Factors in Vibrio vulnificus
Authors: Kim In Hwang , Wen Yancheng , Son Jee-Soo , Lee Kyu-Ho , Kim Kun-Soo 
Published: May 2013

ABSTRACT

The gene
vvpE
, encoding the virulence factor elastase, is a member of the quorum-sensing regulon in
Vibrio vulnificus
and displays enhanced expression at high cell density. We observed that this gene was repressed under iron-rich conditions and that the repression was due to a Fur (
f
erric
u
ptake
r
egulator)-dependent repression of
smcR
, a gene encoding a quorum-sensing master regulator with similarity to
luxR
in
Vibrio harveyi
. A gel mobility shift assay and a footprinting experiment demonstrated that the Fur-iron complex binds directly to two regions upstream of
smcR
(−82 to −36 and −2 to +27, with respect to the transcription start site) with differing affinities. However, binding of the Fur-iron complex is reversible enough to allow expression of
smcR
to be induced by quorum sensing at high cell density under iron-rich conditions. Under iron-limiting conditions, Fur fails to bind either region and the expression of
smcR
is regulated solely by quorum sensing. These results suggest that two biologically important environmental signals, iron and quorum sensing, converge to direct the expression of
smcR
, which then coordinates the expression of virulence factors.
Phosphatidylinositol 4,5-Bisphosphate Is a Novel Coactivator of the Pseudomonas aeruginosa Cytotoxin ExoU
Authors: Tyson Gregory H. , Hauser Alan R. 
Published: May 2013

ABSTRACT

ExoU is a potent phospholipase A
2
effector protein secreted by the type III secretion system of
Pseudomonas aeruginosa
. By cleaving plasma membrane phospholipids, it causes rapid lysis of eukaryotic cells. However, ExoU does not exhibit activity on its own but instead requires eukaryotic cell cofactors for activation. Ubiquitin and ubiquitinated proteins have been shown to activate ExoU, but previous work suggested that other cofactors are also involved. In this study, we demonstrate that phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is another important coactivator of ExoU. PI(4,5)P2 works synergistically with ubiquitin to greatly enhance the phospholipase A
2
activity of ExoU. Distinct residues of ExoU were critical for activation by PI(4,5)P2 and by ubiquitin, indicating that these factors activate ExoU by discrete mechanisms. In support of the biological relevance of PI(4,5)P2 coactivation, a yeast mutant with reduced PI(4,5)P2 levels was less susceptible to the cytotoxic activity of ExoU. Together, these findings further elaborate the molecular mechanism of ExoU.
Functional Characterization of Burkholderia pseudomallei Trimeric Autotransporters
Authors: Campos Cristine G. , Byrd Matthew S. , Cotter Peggy A. 
Published: May 2013

ABSTRACT

Burkholderia pseudomallei
is a tier 1 select agent and the causative agent of melioidosis, a severe and often fatal disease with symptoms ranging from acute pneumonia and septic shock to a chronic infection characterized by abscess formation in the lungs, liver, and spleen. Autotransporters (ATs) are exoproteins belonging to the type V secretion system family, with many playing roles in pathogenesis. The genome of
B. pseudomallei
strain 1026b encodes nine putative trimeric AT proteins, of which only four have been described. Using a bioinformatic approach, we annotated putative domains within each trimeric AT protein, excluding the well-studied BimA protein, and found short repeated sequences unique to
Burkholderia
species, as well as an unexpectedly large proportion of ATs with extended signal peptide regions (ESPRs). To characterize the role of trimeric ATs in pathogenesis, we constructed disruption or deletion mutations in each of eight AT-encoding genes and evaluated the resulting strains for adherence to, invasion of, and plaque formation in A549 cells. The majority of the ATs (and/or the proteins encoded downstream) contributed to adherence to and efficient invasion of A549 cells. Using a BALB/c mouse model of infection, we determined the contributions of each AT to bacterial burdens in the lungs, liver, and spleen. At 48 h postinoculation, only one strain, Bp340::pD
bpaC
, demonstrated a defect in dissemination and/or survival in the liver, indicating that BpaC is required for wild-type virulence in this model.
Protective Efficacy Induced by Recombinant Clostridium difficile Toxin Fragments
Authors: Leuzzi Rosanna , Spencer Janice , Buckley Anthony , Brettoni Cecilia , Martinelli Manuele , Tulli Lorenza , Marchi Sara , Luzzi Enrico , Irvine June , Candlish Denise , Veggi Daniele , Pansegrau Werner , Fiaschi Luigi , Savino Silvana , Swennen Erwin , Cakici Osman , Oviedo-Orta Ernesto , Giraldi Monica , Baudner Barbara , D'Urzo Nunzia , Maione Domenico , Soriani Marco , Rappuoli Rino , Pizza Mariagrazia , Douce Gillian R. , Scarselli Maria 
Published: May 2013

ABSTRACT

Clostridium difficile
is a spore-forming bacterium that can reside in animals and humans.
C. difficile
infection causes a variety of clinical symptoms, ranging from diarrhea to fulminant colitis. Disease is mediated by TcdA and TcdB, two large enterotoxins released by
C. difficile
during colonization of the gut. In this study, we evaluated the ability of recombinant toxin fragments to induce neutralizing antibodies in mice. The protective efficacies of the most promising candidates were then evaluated in a hamster model of disease. While limited protection was observed with some combinations, coadministration of a cell binding domain fragment of TcdA (TcdA-B1) and the glucosyltransferase moiety of TcdB (TcdB-GT) induced systemic IgGs which neutralized both toxins and protected vaccinated animals from death following challenge with two strains of
C. difficile
. Further characterization revealed that despite high concentrations of toxin in the gut lumens of vaccinated animals during the acute phase of the disease, pathological damage was minimized. Assessment of gut contents revealed the presence of TcdA and TcdB antibodies, suggesting that systemic vaccination with this pair of recombinant polypeptides can limit the disease caused by toxin production during
C. difficile
infection.
Clinical supervision in a UK military Department of Community Mental Health
Authors: Wesson Matthew I , Whybrow D , Greenberg N , Gould M 
Published: May 2013

ObjectivesRecent service developments in the NHS on the provision of talking therapies such as the Improving Access to Psychological Therapies (IAPT) initiative have made the compliance with clinical supervision (CS) inherent among its service guidelines. This paper presents the findings of an audit, measuring compliance with CS among clinicians providing psychological therapies within a military Department of Community Mental Health.MethodAdherence to the recommended monthly supervision and the presence of an indate CS contract were audited on two separate occasions over 2 years by analysing the departmental electronic CS database.ResultsCompliance rates were found to be lower than the Defence guidelines, which are already modest in their expectations compared with IAPT CS standards.DiscussionPotential reasons are hypothesised including high levels of staff rotation, other military commitments, clinicians not keeping up-to-date records and the pressures of meeting performance indicators on other clinical issues. Proposals for improving the uptake of CS are suggested along with areas for further research.
Stentrievers versus other endovascular treatment methods for acute stroke: comparison of procedural results and their relationship to outcomes
Authors: Ribo Marc , Molina Carlos A , Jankowitz Brian , Tomasello Alejandro , Zaidi Syed , Jumaa Mouhammad , Coscojuela Pilar , Oakley Jennifer , Alvarez-Sabín José , Jovin Tudor 
Published: May 2013

Background and purposeThe use of stentrievers (ST) is rapidly growing due to several potential benefits over other available treatments. ST potentially restore flow before clot retrieval and reduce procedural time. We aimed to study the impact of these potential benefits.MethodsPatients with acute stroke treated with endovascular procedures in two stroke centers were studied. According to device availability, patients were treated either with intra-arterial tissue plasminogen activator (IAT), Merci or ST. We defined time to initial flow restoration as time from symptom onset to first pass of contrast to previously occluded arteries either through the deployed device or after recanalization. Complete recanalization (Thrombolysis In Cerebral Infarction >2b), day 5 National Institute of Health Stroke Scale (NIHSS) score and favorable outcome at 3 months (modified Rankin Scale score≤2) were recorded.ResultsA total of 315 patients were studied: 127 IAT, 119 Merci, 69 ST (26 Trevo, 43 Solitaire). No major differences were observed in baseline characteristics between the treatment groups. The rate of complete recanalization was higher with ST (67.2%) than with IAT (50.8%) or Merci (57.3%) (p=0.05). Time from groin puncture to final recanalization was lower with ST (88±46 min) than with IAT (103±70 min) or Merci (128±62 min) (p<0.01) and time from groin puncture to initial flow restoration was shorter with ST (36±18 min) than with IAT (92±67 min) or Merci (114±57 min) (p<0.01). Discharge NIHSS was lower in the ST group (7, IQR 1–26) than in the IAT (14, 2–30) or Merci (12, 5–30) groups (p=0.05) and the rate of favorable outcome was higher: ST (52.9%) vs IAT (33.9%) and Merci (40%) (p=0.03). The use of a ST increased the odds of a favorable outcome (OR 1.9, 95% CI 1.04 to 3.39; p=0.037).ConclusionsIn acute endovascular treatment of stroke, the use of ST may increase recanalization and reduce time to flow restoration leading to improved outcomes.
Republished: Paediatric early warning scores: Holy Grail and Achilles' heel
Authors: Roland Damian 
Published: May 2013

Abstract
Early Warning Scores (EWS) have become increasingly used by hospitals throughout the world to prevent unexpected admission to intensive care or even death in their inpatient population. It is well known that signs of deterioration are present well before collapse and by a combination of systems, EWS enable healthcare professionals to intervene at an appropriate time. A number of national bodies and regulators in the UK have required the use of Early Warning Scores in locations where children are inpatients. This article attempts to describe the background to their development, identify common problems and provide information for units interested in introducing an EWS into their department.
Republished: Non-invasive urine based tests for the detection of bladder cancer
Authors: Wadhwa Neha , Jatawa Suresh Kumar , Tiwari Archana 
Published: May 2013

Abstract
Bladder cancer is the fourth most frequently diagnosed malignant neoplasm and cause of cancer-related deaths in men and eighth in women. Patients with bladder cancer undergo repeated cystoscopic examinations of the bladder to monitor for tumour recurrence which is invasive, costly and lacks accuracy. Therefore, the development of non-invasive urine based tests for the early detection of bladder cancer would be of tremendous benefit to both patients and healthcare systems. A number of urine based markers are available for the early diagnosis of bladder cancer. The diagnosis of bladder cancer relies on identifying malignant cells in the urine. All urinary markers have a higher sensitivity as compared with cytology but they score lower in specificity. Many soluble and cell based markers have been developed. Only two of the soluble and cell based markers have obtained the Food and Drug Administration approval. In the current review, the most recent literature of urinary markers is summarised. This article reports some of the more prominent urine markers and new technologies used nowadays.
A spectral‐domain optical coherence tomography device provides reliable corneal pachymetry measurements in canine eyes
Authors: Alario A. F. , Pirie C. G. 
Published: May 2013

The objective of this study was to determine central corneal thickness (CCT) and the intra‐ and interuser reliability using a portable spectral‐domain optical coherence tomography (SD‐OCT) device in canine eyes. Twenty clinically normal dogs were examined. CCT measurements were obtained from both eyes of each animal three times by two operators in succession. The CCT was automatically calculated using the pachymetry software generated from eight radial scans, 6 mm in length. Mean canine CCT was 606.83±39.45 μm for all eyes examined. There was no significant difference in CCT based on the eye examined (OD vs OS), age or gender of the animal. There was no significant difference in CCT between replicates performed by the same operator; however, a small but significant difference was noted in CCT between operators. The mean difference in CCT between operators was 1.9 μm (P=0.03). The coefficient of variation for each user and between users was very low (range 0.64–1.7 per cent). The intraclass correlation coefficient comparing operators was 0.975. Based on these results, the SD‐OCT device evaluated is capable of obtaining precise CCT measurements with excellent intra‐ and interoperator reliability in canine eyes.
Long-term Morphofunctional Remodeling of Internal Thoracic Artery Grafts
Authors: Porto Italo , Gaudino Mario , De Maria Giovanni Luigi , Di Vito Luca , Vergallo Rocco , Bruno Piergiorgio , Bonalumi Giorgia , Prati Francesco , Bolognese Leonardo , Crea Filippo , Massetti Massimo 
Published: May 2013

Background—
Internal thoracic arteries (ITAs) are frequently anastomosed to the coronary circulation for bypass grafting. The purpose of this research was to investigate in vivo the long-term morphofunctional changes of ITAs after their use as coronary artery bypass conduits, by comparing the morphological features and vasoreactivity of the grafted left ITA (LITA) with the native, nonharvested right ITA (RITA) in the same patient.

Methods and Results—

At least 10 years after surgery, in 10 patients, LITA graft and nonharvested RITA were assessed by quantitative angiography and frequency-domain optical tomography. Endothelium-dependent and independent vasodilation was tested by selective infusion of acetylcholine and isosorbide dinitrate. Quantitative angiography showed that baseline mean diameter of LITA graft was significantly smaller than that of RITA (2.59 mm [2.29–3.04] versus 3.05 mm [2.75–3.32];
P
=0.01). LITA showed a significant intimal thickening (
P
=0.05) and a nonsignificant medial thinning (
P
=0.22) compared with RITA, leading to an increased intima-media ratio (intima-media ratio, 0.72 [0.53–0.91] versus 0.23 [0.12–0.38];
P
=0.02). The intima-media ratio correlated inversely with the vasodilatatory response in RITA (
r
=−0.68,
P
=0.03 for acetylcholine and
r
=−0.62,
P
=0.05 for isosorbide dinitrate) but not in LITA (
r
=−0.18,
P
=0.63 for acetylcholine and
r
=−0.11,
P
=0.75 for isosorbide dinitrate).

Conclusions—
Ten years after implantation to the coronary circulation, LITA grafts show intimal thickening, increased intima/media ratio, and maintained endothelium-derived vasodilation. These changes are likely to be an adaptive answer to the different flow dynamics typical of coronary circulation.
Development and Validation of a Risk Score to Predict QT Interval Prolongation in Hospitalized Patients
Authors: Tisdale James E. , Jaynes Heather A. , Kingery Joanna R. , Mourad Noha A. , Trujillo Tate N. , Overholser Brian R. , Kovacs Richard J. 
Published: May 2013

Background—
Identifying hospitalized patients at risk for QT interval prolongation could lead to interventions to reduce the risk of torsades de pointes. Our objective was to develop and validate a risk score for QT prolongation in hospitalized patients.

Methods and Results—

In this study, in a single tertiary care institution, consecutive patients (n=900) admitted to cardiac care units comprised the risk score development group. The score was then applied to 300 additional patients in a validation group. Corrected QT (QT
c
) interval prolongation (defined as QT
c
>500 ms or an increase of >60 ms from baseline) occurred in 274 (30.4%) and 90 (30.0%) patients in the development group and validation group, respectively. Independent predictors of QT
c
prolongation included the following: female (odds ratio, 1.5; 95% confidence interval, 1.1–2.0), diagnosis of myocardial infarction (2.4 [1.6–3.9]), sepsis (2.7 [1.5–4.8]), left ventricular dysfunction (2.7 [1.6–5.0]), administration of a QT-prolonging drug (2.8 [2.0–4.0]), ≥2 QT-prolonging drugs (2.6 [1.9–5.6]), or loop diuretic (1.4 [1.0–2.0]), age >68 years (1.3 [1.0–1.9]), serum K
+
<3.5 mEq/L (2.1 [1.5–2.9]), and admitting QT
c
>450 ms (2.3; confidence interval [1.6–3.2]). Risk scores were developed by assigning points based on log odds ratios. Low-, moderate-, and high-risk ranges of 0 to 6, 7 to 10, and 11 to 21 points, respectively, best predicted QT
c
prolongation (C statistic=0.823). A high-risk score ≥11 was associated with sensitivity=0.74, specificity=0.77, positive predictive value=0.79, and negative predictive value=0.76. In the validation group, the incidences of QT
c
prolongation were 15% (low risk); 37% (moderate risk); and 73% (high risk).

Conclusions—

A risk score using easily obtainable clinical variables predicts patients at highest risk for QT
c
interval prolongation and may be useful in guiding monitoring and treatment decisions.