bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen Peroxide Production from Glycerol Metabolism Is Dispensable for Virulence of Mycoplasma gallisepticum in the Tracheas of Chickens
Authors: Szczepanek S. M. , Boccaccio M. , Pflaum K. , Liao X. , Geary S. J. 
Published: August 2014

ABSTRACT

Hydrogen peroxide (H
2
O
2
) is a by-product of glycerol metabolism in mycoplasmas and has been shown to cause cytotoxicity for cocultured eukaryotic cells. There appears to be selective pressure for mycoplasmas to retain the genes needed for glycerol metabolism. This has generated interest and speculation as to their function during infection. However, the actual effects of glycerol metabolism and H
2
O
2
production on virulence
in vivo
have never been assessed in any
Mycoplasma
species. To this end, we determined that the wild-type (WT) R
low
strain of the avian pathogen
Mycoplasma gallisepticum
is capable of producing H
2
O
2
when grown in glycerol and is cytotoxic to eukaryotic cells in culture. Transposon mutants with mutations in the genes present in the glycerol transport and utilization pathway, namely,
glpO
,
glpK
, and
glpF
, were identified. All mutants assessed were incapable of producing H
2
O
2
and were not cytotoxic when grown in glycerol. We also determined that vaccine strains ts-11 and 6/85 produce little to no H
2
O
2
when grown in glycerol, while the naturally attenuated F strain does produce H
2
O
2
. Chickens were infected with one of two
glpO
mutants, a
glpK
mutant, R
low
, or growth medium, and tracheal mucosal thickness and lesion scores were assessed. Interestingly, all
glp
mutants were reproducibly virulent in the respiratory tracts of the chickens. Thus, there appears to be no link between glycerol metabolism/H
2
O
2
production/cytotoxicity and virulence for this
Mycoplasma
species in its natural host. However, it is possible that glycerol metabolism is required by
M. gallisepticum
in a niche that we have yet to study.
Inhibition of Local Immune Responses by the Frog-Killing Fungus Batrachochytrium dendrobatidis
Authors: Fites J. Scott , Reinert Laura K. , Chappell Timothy M. , Rollins-Smith Louise A. 
Published: August 2014

ABSTRACT

Amphibians are suffering unprecedented global declines. A leading cause is the infectious disease chytridiomycosis caused by the chytrid fungus
Batrachochytrium dendrobatidis
. Chytridiomycosis is a skin disease which disrupts transport of essential ions leading to death. Soluble factors produced by
B. dendrobatidis
impair amphibian and mammalian lymphocytes
in vitro
, but previous studies have not shown the effects of these inhibitory factors
in vivo
. To demonstrate
in vivo
inhibition of immunity by
B. dendrobatidis
, a modified delayed-type-hypersensitivity (DTH) protocol was developed to induce innate and adaptive inflammatory swelling in the feet of
Xenopus laevis
by injection of killed bacteria or phytohemagglutinin (PHA). Compared to previous protocols for PHA injection in amphibians, this method induced up to 20-fold greater inflammatory swelling. Using this new protocol, we measured DTH responses induced by killed bacteria or PHA in the presence of
B. dendrobatidis
supernatants. Swelling induced by single injection of PHA or killed bacteria was not significantly affected by
B. dendrobatidis
supernatants. However, swelling caused by a secondary injection of PHA, was significantly reduced by
B. dendrobatidis
supernatants. As previously described
in vitro
, factors from
B. dendrobatidis
appear to inhibit lymphocyte-mediated inflammatory swelling but not swelling caused by an inducer of innate leukocytes. This suggests that
B. dendrobatidis
is capable of inhibiting lymphocytes in a localized response to prevent adaptive immune responses in the skin. The modified protocol used to induce inflammatory swelling in the present study may be more effective than previous methods to investigate amphibian immune competence, particularly in nonmodel species.
Genetic Examination and Mass Balance Analysis of Pyruvate/Amino Acid Oxidation Pathways in the Hyperthermophilic Archaeon Thermococcus kodakarensis
Authors: Nohara Kenta , Orita Izumi , Nakamura Satoshi , Imanaka Tadayuki , Fukui Toshiaki 
Published: August 2014

ABSTRACT

The present study investigated the simultaneous oxidation of pyruvate and amino acids during H
2
-evolving growth of the hyperthermophilic archaeon
Thermococcus kodakarensis
. The comparison of mass balance between a cytosolic hydrogenase (HYH)-deficient strain (the Δ
hyhBGSL
strain) and the parent strain indicated that NADPH generated via H
2
uptake by HYH was consumed by reductive amination of 2-oxoglutarate catalyzed by glutamate dehydrogenase. Further examinations were done to elucidate functions of three enzymes potentially involved in pyruvate oxidation: pyruvate formate-lyase (PFL), pyruvate:ferredoxin oxidoreductase (POR), and 2-oxoisovalerate:ferredoxin oxidoreductase (VOR) under the HYH-deficient background in
T. kodakarensis
. No significant change was observed by deletion of
pflDA
, suggesting that PFL had no critical role in pyruvate oxidation. The growth properties and mass balances of Δ
porDAB
and Δ
vorDAB
strains indicated that POR and VOR specifically functioned in oxidation of pyruvate and branched-chain amino acids, respectively, and the lack of POR or VOR was compensated for by promoting the oxidation of another substrate driven by the remaining oxidoreductase. The H
2
yields from the consumed pyruvate and amino acids were increased from 31% by the parent strain to 67% and 82% by the deletion of
hyhBGSL
and double deletion of
hyhBGSL
and
vorDAB
, respectively. Significant discrepancies in the mass balances were observed in excess formation of acetate and NH
3
, suggesting the presence of unknown metabolisms in
T. kodakarensis
grown in the rich medium containing pyruvate.
Listeria monocytogenes Is Resistant to Lysozyme through the Regulation, Not the Acquisition, of Cell Wall-Modifying Enzymes
Authors: Burke Thomas P. , Loukitcheva Anastasia , Zemansky Jason , Wheeler Richard , Boneca Ivo G. , Portnoy Daniel A. 
Published: August 2014

ABSTRACT

Listeria monocytogenes
is a Gram-positive facultative intracellular pathogen that is highly resistant to lysozyme, a ubiquitous enzyme of the innate immune system that degrades cell wall peptidoglycan. Two peptidoglycan-modifying enzymes, PgdA and OatA, confer lysozyme resistance on
L. monocytogenes
; however, these enzymes are also conserved among lysozyme-sensitive nonpathogens. We sought to identify additional factors responsible for lysozyme resistance in
L. monocytogenes
. A forward genetic screen for lysozyme-sensitive mutants led to the identification of 174 transposon insertion mutations that mapped to 13 individual genes. Four mutants were killed exclusively by lysozyme and not other cell wall-targeting molecules, including the peptidoglycan deacetylase encoded by
pgdA
, the putative carboxypeptidase encoded by
pbpX
, the orphan response regulator encoded by
degU
, and the highly abundant noncoding RNA encoded by
rli31
. Both
degU
and
rli31
mutants had reduced expression of
pbpX
and
pgdA
, yet DegU and Rli31 did not regulate each other. Since
pbpX
and
pgdA
are also present in lysozyme-sensitive bacteria, this suggested that the acquisition of novel enzymes was not responsible for lysozyme resistance, but rather, the regulation of conserved enzymes by DegU and Rli31 conferred high lysozyme resistance. Each lysozyme-sensitive mutant exhibited attenuated virulence in mice, and a time course of infection revealed that the most lysozyme-sensitive strain was killed within 30 min of intravenous infection, a phenotype that was recapitulated in purified blood. Collectively, these data indicate that the genes required for lysozyme resistance are highly upregulated determinants of
L. monocytogenes
pathogenesis that are required for avoiding the enzymatic activity of lysozyme in the blood.
CcpA-Mediated Catabolite Activation of the Bacillus subtilis ilv-leu Operon and Its Negation by Either CodY- or TnrA-Mediated Negative Regulation
Authors: Fujita Yasutaro , Satomura Takenori , Tojo Shigeo , Hirooka Kazutake 
Published: August 2014

ABSTRACT

The
Bacillus subtilis ilv-leu
operon functions in the biosynthesis of branched-chain amino acids. It undergoes catabolite activation involving a promoter-proximal
cre
which is mediated by the complex of CcpA and P-Ser-HPr. This activation of
ilv-leu
expression is negatively regulated through CodY binding to a high-affinity site in the promoter region under amino acid-rich growth conditions, and it is negatively regulated through TnrA binding to the TnrA box under nitrogen-limited growth conditions. The CcpA-mediated catabolite activation of
ilv-leu
required a helix face-dependent interaction of the complex of CcpA and P-Ser-HPr with RNA polymerase and needed a 19-nucleotide region upstream of
cre
for full activation. DNase I footprinting indicated that CodY binding to the high-affinity site competitively prevented the binding of the complex of CcpA and P-Ser-HPr to
cre
. This CodY binding not only negated catabolite activation but also likely inhibited transcription initiation from the
ilv-leu
promoter. The footprinting also indicated that TnrA and the complex of CcpA and P-Ser-HPr simultaneously bound to the TnrA box and the
cre
site, respectively, which are 112 nucleotides apart; TnrA binding to its box was likely to induce DNA bending. This implied that interaction of TnrA bound to its box with the complex of CcpA and P-Ser-HPr bound to
cre
might negate catabolite activation, but TnrA bound to its box did not inhibit transcription initiation from the
ilv-leu
promoter. Moreover, this negation of catabolite activation by TnrA required a 26-nucleotide region downstream of the TnrA box.
Hydrogen Formation and Its Regulation in Ruminococcus albus: Involvement of an Electron-Bifurcating [FeFe]-Hydrogenase, of a Non-Electron-Bifurcating [FeFe]-Hydrogenase, and of a Putative Hydrogen-Sensing [FeFe]-Hydrogenase
Authors: Zheng Yanning , Kahnt Jörg , Kwon In Hyuk , Mackie Roderick I. , Thauer Rudolf K. 
Published: August 2014

ABSTRACT

Ruminococcus albus
7 has played a key role in the development of the concept of interspecies hydrogen transfer. The rumen bacterium ferments glucose to 1.3 acetate, 0.7 ethanol, 2 CO
2
, and 2.6 H
2
when growing in batch culture and to 2 acetate, 2 CO
2
, and 4 H
2
when growing in continuous culture in syntrophic association with H
2
-consuming microorganisms that keep the H
2
partial pressure low. The organism uses NAD
+
and ferredoxin for glucose oxidation to acetyl coenzyme A (acetyl-CoA) and CO
2
, NADH for the reduction of acetyl-CoA to ethanol, and NADH and reduced ferredoxin for the reduction of protons to H
2
. Of all the enzymes involved, only the enzyme catalyzing the formation of H
2
from NADH remained unknown. Here, we report that
R. albus
7 grown in batch culture on glucose contained, besides a ferredoxin-dependent [FeFe]-hydrogenase (HydA2), a ferredoxin- and NAD-dependent electron-bifurcating [FeFe]-hydrogenase (HydABC) that couples the endergonic formation of H
2
from NADH to the exergonic formation of H
2
from reduced ferredoxin. Interestingly,
hydA2
is adjacent to the
hydS
gene, which is predicted to encode an [FeFe]-hydrogenase with a C-terminal PAS domain. We showed that
hydS
and
hydA2
are part of a larger transcriptional unit also harboring putative genes for a bifunctional acetaldehyde/ethanol dehydrogenase (Aad), serine/threonine protein kinase, serine/threonine protein phosphatase, and a redox-sensing transcriptional repressor. Since HydA2 and Aad are required only when
R. albus
grows at high H
2
partial pressures, HydS could be a H
2
-sensing [FeFe]-hydrogenase involved in the regulation of their biosynthesis.
Cell Division Resets Polarity and Motility for the Bacterium Myxococcus xanthus
Authors: Harvey Cameron W. , Madukoma Chinedu S. , Mahserejian Shant , Alber Mark S. , Shrout Joshua D. 
Published: August 2014

ABSTRACT

Links between cell division and other cellular processes are poorly understood. It is difficult to simultaneously examine division and function in most cell types. Most of the research probing aspects of cell division has experimented with stationary or immobilized cells or distinctly asymmetrical cells. Here we took an alternative approach by examining cell division events within motile groups of cells growing on solid medium by time-lapse microscopy. A total of 558 cell divisions were identified among approximately 12,000 cells. We found an interconnection of division, motility, and polarity in the bacterium
Myxococcus xanthus
. For every division event, motile cells stop moving to divide. Progeny cells of binary fission subsequently move in opposing directions. This behavior involves
M. xanthus
Frz proteins that regulate
M. xanthus
motility reversals but is independent of type IV pilus “S motility.” The inheritance of opposing polarity is correlated with the distribution of the G protein RomR within these dividing cells. The constriction at the point of division limits the intracellular distribution of RomR. Thus, the asymmetric distribution of RomR at the parent cell poles becomes mirrored at new poles initiated at the site of division.
Use of probiotics to correct dysbiosis of normal microbiota following disease or disruptive events: a systematic review
Authors: McFarland Lynne V 
Published: August 2014

ObjectiveTo assess the evidence for the claim probiotics can correct dysbiosis of the normal microbiota resulting from disease or disruptive events.SettingSystematic review of published clinical trials of patients receiving a probiotic intervention for the prevention or treatment of various diseases.Data sourcesSources searched (1985–2013): PubMed, EMBASE, Cochrane Database of Systematic Reviews, CINAHL, AMED and ISI Web of Science. Three on-line clinical trial registries were searched: Cochrane Central Register of Controlled trials, MetaRegister of Controlled Trials and National Institutes of Health.Review methodsIncluded studies were randomised clinical trials of probiotic interventions having microbiological assays. Studies were evaluated following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for specific probiotic strains. A standard data extraction form was used to collect the raw data.Outcome measuresThe primary outcome is the degree of microbiota correction by specific probiotic strains. Secondary outcome was the association between the degree of dysbiosis correction and clinical efficacy.ResultsThe review of the literature found three distinct study designs: model A (restoration) assayed patients enrolled with a healthy, undisturbed microbiota and then assayed postdisruptive event and probiotic therapy; model B (alteration) assayed patients with pre-existing disrupted microbiota and then postprobiotic therapy; model C (no dysbiosis) assayed volunteers with no disruptive event prebiotic and postprobiotic. From a total of 63 trials, 83% of the probiotic products using model A restored the microbiota, 56% using model B improved the microbiota and only 21% using model C had any effect on microbiota. Clinical efficacy was more commonly associated with strains capable of restoration of the normal microbiota.ConclusionsThe ability to assess the degree of dysbiosis improvement is dependent on the enrolled population and the timing of microbiological assays. The functional claim for correcting dysbiosis is poorly supported for most probiotic strains and requires further research.Trial registration numberPROSPERO (CRD42014007224).
A systematic review of behavioural marker systems in healthcare: what do we know about their attributes, validity and application?
Authors: Dietz Aaron S , Pronovost Peter J , Benson Kari N , Mendez-Tellez Pedro Alejandro , Dwyer Cynthia , Wyskiel Rhonda , Rosen Michael A 
Published: August 2014

ObjectiveBehavioural marker systems are advocated as a method for providing accurate assessments, directing feedback and determining the impact of teamwork improvement initiatives. The present article reports on the state of quality surrounding their use in healthcare and discusses the implications of these findings for future research, development and application. In doing so, this article provides a practical resource where marker systems can be selected and evaluated based on their strengths and limitations.MethodsFour research questions framed this review: what are the attributes of behavioural marker systems? What evidence of reliability and validity exists? What skills and expertise are required for their use? How have they been applied to investigate the relationship between teamwork and other constructs?ResultsBehavioural markers systems are generally designed for specific work domains or tasks. They often cover similar content with inconsistent terminology, which complicates the comparison of research findings across clinical domains. Although several approaches were used to establish the reliability and validity of marker systems, the marker system literature, as a whole, requires more robust reliability and validity evidence. The impact of rater training on rater proficiency was mixed, but evidence suggests that improvements can be made over time.ConclusionsA consensus of definitions for teamwork constructs must be reached to ensure that the meaning behind behavioural measurement is understood across disciplines, work domains and task types. Future development efforts should focus on the cost effectiveness and feasibility of measurement tools including time spent training raters. Further, standards for the testing and reporting of psychometric evidence must be established. Last, a library of tools should be generated around whether the instrument measures general or domain-specific behaviours.
UNUSUAL CASE OF AN ELBOW MASS CAUSED BY CANDIDA ARTHRITIS IN A PATIENT WITH SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: Imamura Hitoshi , Iwamoto Takuji , Momohara Shigeki 
Published: August 2014

A 45-year-old woman with systemic lupus erythematosus presented with a painless bulky mass on her elbow. Joint fluid analysis showed the presence of a yeast-like organism. Surgical debridement was performed and specimens obtained at surgery showed growth of Candida albicans. Although Candida species are an uncommon cause of infectious arthritis, fungal arthritis should be considered in the patient with predisposing factors.
THE HOLEVICH FLAP REVISITED: A COMPARISON WITH THE FOUCHER FLAP, CASE SERIES
Authors: Couceiro José , Sanmartín Marcos 
Published: August 2014

The first dorsal metacarpal artery flap was initially described by Hilgenfeldt, it was designed as a racquet flap by Holevich and modified as an island flap by Foucher and Braun. The objective of the present is to compare the Holevich flap and the Foucher flap in terms of venous congestion and flap necrosis. From 2009 to 2013, ten first dorsal metacarpal artery flaps were performed at our hospital's hand unit. Five of the flaps were Holevich type flaps and five of the flaps were Foucher flaps. There were seven men and three women. The mean age was 47 years for the Foucher flap group (17–67 years), and 48 years for the Holevich flap group (36–61 years). Strength, static two tips discrimination, ranges of motion, satisfaction, cold intolerance, pain, flap congestion and flap necrosis were recorded for both groups. Similar values of strength, pain, range of motion and two tips discrimination were found on both groups. There was a higher incidence of flap congestion and necrosis on the Foucher flap group (two thumbs underwent partial flap necrosis and two underwent venous congestion in three patients). There was also a higher incidence of cold intolerance in the Foucher group (two patients exhibited moderate cold intolerance and one exhibited a severe cold intolerance). A proper statistical analysis was not possible due to the size of the case series. In this small case series the Holevich exhibited less flap necrosis, less venous congestion, and less incidence of cold intolerance than the Foucher flap.
Dietary Inflammatory Index and Risk of Colorectal Cancer in the Iowa Women's Health Study
Authors: Shivappa Nitin , Prizment Anna E. , Blair Cindy K. , Jacobs David R. , Steck Susan E. , Hébert James R. 
Published: August 2014

AbstractBackground: Colorectal cancer, the third most common cancer in the United States, has a natural history that usually encompasses several decades. Dietary components have been implicated in the etiology of colorectal cancer, perhaps through their effect on inflammation.Methods: We examined the ability of the dietary inflammatory index (DII) to predict colorectal cancer in the Iowa Women's Health Study. The DII was computed based on dietary intake assessed by a 121-item food frequency questionnaire in this cohort of 34,703 women, ages 55 to 69 years, free of any self-reported prior malignancy at enrollment in 1986. Incident colorectal cancer cases were identified through linkage with the State Health Registry of Iowa (a Surveillance, Epidemiology, and End Results program member). Cox proportional hazards regression was used to estimate HRs. Through the end of 2010, 1,636 incident colorectal cancers were identified, including 1,329 colon and 325 rectal cancers.Results: Multivariable analysis, adjusting for body mass index, smoking status, pack-years of smoking, hormone replacement therapy, education, diabetes, and total energy intake, revealed positive associations between higher DII and colorectal cancer risk [HR for DIIcontinuous: 1.07 per unit increase in DII (corresponding to 0.5 SD unit increase); 95% confidence interval (CI), 1.01–1.13; HR for DIIquintiles: Q5 vs. Q1 = 1.20; 95% CI, 1.01–1.43]. HRs for DII were similar for colon cancer and rectal cancer, though not statistically significant for rectal cancer.Conclusions: These results indicate that a proinflammatory diet, as indicated by higher DII scores, was associated with higher risk of developing colorectal cancer.Impact: Proinflammatory diets are associated with increased risk of colorectal cancer. Cancer Epidemiol Biomarkers Prev; 23(11); 2383–92. ©2014 AACR.
Safety and Feasibility of Closed Chest Epicardial Catheter Ablation Using Electroporation
Authors: Neven Kars , van Driel Vincent , van Wessel Harry , van Es René , du Pré Bastiaan , Doevendans Pieter A. , Wittkampf Fred 
Published: August 2014

Background—
Permanent coronary artery damage is a hazardous complication of epicardial radiofrequency ablation. Irreversible electroporation (IRE) is a promising nonthermal ablation modality able to create deep myocardial lesions. We investigated the effects of epicardial IRE on luminal coronary artery diameter and lesion depth.

Methods and Results—

In 5 pigs (60–75 kg), the pericardium was exposed using surgical subxiphoidal epicardial access. A custom deflectable octopolar 12-mm circular catheter with 2-mm ring electrodes was introduced in the pericardium via a steerable sheath. After coronary angiography (CAG), the proximal, mid, and distal left anterior descending, and circumflex coronary arteries were targeted with a single, cathodal 200 J application. CAG was repeated after IRE and after 3 months follow-up. Using quantitative CAG, the minimal luminal diameter at the lesion site was compared with the average of the diameters just proximal and distal to that lesion. Intimal hyperplasia and lesion size were measured histologically. CAG directly postablation demonstrated short-lasting luminal narrowing with normalization in the targeted area, suggestive of coronary spasm. After 3 months, all CAGs were identical to preablation CAGs: mean reference luminal diameter was 2.2±0.3 mm, mean luminal diameter at the lesion site was 2.1±0.3 mm (
P
=0.35). Average intimal hyperplasia in all arteries was 2±4%. Median lesion depth was 6.4±2.6 mm.

Conclusions—
Luminal coronary artery diameter remained unaffected 3 months after epicardial IRE, purposely targeting the coronary arteries. IRE can create deep lesions and is a safe modality for catheter ablation on or near coronary arteries.