bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the
xplAB
-Containing Gene Cluster Involved in the Bacterial Degradation of the Explosive Hexahydro-1,3,5-Trinitro-1,3,5-Triazine
Authors: Chong Chun Shiong , Sabir Dana Khdr , Lorenz Astrid , Bontemps Cyril , Andeer Peter , Stahl David A. , Strand Stuart E. , Rylott Elizabeth L. , Bruce Neil C.
Published: August 2014

Repeated use of the explosive compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) on military land has resulted in significant soil and groundwater pollution. Rates of degradation of RDX in the environment are low, and accumulated RDX, which the U.S. Environmental Protection Agency has determined is a possible human carcinogen, is now threatening drinking water supplies. RDX-degrading microorganisms have been isolated from RDX-contaminated land; however, despite the presence of these species in contaminated soils, RDX pollution persists. To further understand this problem, we studied RDX-degrading species belonging to four different genera (
Rhodococcus
,
Microbacterium
,
Gordonia
, and
Williamsia
) isolated from geographically distinct locations and established that the
xplA
and
xplB
(
xplAB
) genes, which encode a cytochrome P450 and a flavodoxin redox partner, respectively, are nearly identical in all these species. Together, the
xplAB
system catalyzes the reductive denitration of RDX and subsequent ring cleavage under aerobic and anaerobic conditions. In addition to
xplAB
, the
Rhodococcus
species studied here share a 14-kb region flanking
xplAB
; thus, it appears likely that the RDX-metabolizing ability was transferred as a genomic island within a transposable element. The conservation and transfer of
xplAB
-flanking genes suggest a role in RDX metabolism. We therefore independently knocked out genes within this cluster in the RDX-degrading species
Rhodococcus rhodochrous
11Y. Analysis of the resulting mutants revealed that XplA is essential for RDX degradation and that XplB is not the sole contributor of reducing equivalents to XplA. While XplA expression is induced under nitrogen-limiting conditions and further enhanced by the presence of RDX, MarR is not regulated by RDX.
Characterization of Novel Polycyclic Aromatic Hydrocarbon Dioxygenases from the Bacterial Metagenomic DNA of a Contaminated Soil
Authors: Chemerys Angelina , Pelletier Eric , Cruaud Corinne , Martin Florence , Violet Fabien , Jouanneau Yves
Published: August 2014

Ring-hydroxylating dioxygenases (RHDs) play a crucial role in the biodegradation of a range of aromatic hydrocarbons found on polluted sites, including polycyclic aromatic hydrocarbons (PAHs). Current knowledge on RHDs comes essentially from studies on culturable bacterial strains, while compelling evidence indicates that pollutant removal is mostly achieved by uncultured species. In this study, a combination of DNA-SIP labeling and metagenomic sequence analysis was implemented to investigate the metabolic potential of main PAH degraders on a polluted site. Following
in situ
labeling using [
13
C]phenanthrene, the labeled metagenomic DNA was isolated from soil and subjected to shotgun sequencing. Most annotated sequences were predicted to belong to
Betaproteobacteria
, especially
Rhodocyclaceae
and
Burkholderiales
, which is consistent with previous findings showing that main PAH degraders on this site were affiliated to these taxa. Based on metagenomic data, four RHD gene sets were amplified and cloned from soil DNA. For each set, PCR yielded multiple amplicons with sequences differing by up to 321 nucleotides (17%), reflecting the great genetic diversity prevailing in soil. RHDs were successfully overexpressed in
Escherichia coli
, but full activity required the coexpression of two electron carrier genes, also cloned from soil DNA. Remarkably, two RHDs exhibited much higher activity when associated with electron carriers from a sphingomonad. The four RHDs showed markedly different preferences for two- and three-ring PAHs but were poorly active on four-ring PAHs. Three RHDs preferentially hydroxylated phenanthrene on the C-1 and C-2 positions rather than on the C-3 and C-4 positions, suggesting that degradation occurred through an alternate pathway.
Engineering of Pseudomonas taiwanensis VLB120 for Constitutive Solvent Tolerance and Increased Specific Styrene Epoxidation Activity
Authors: Volmer Jan , Neumann Christoph , Bühler Bruno , Schmid Andreas
Published: August 2014

The application of whole cells as biocatalysts is often limited by the toxicity of organic solvents, which constitute interesting substrates/products or can be used as a second phase for
in situ
product removal and as tools to control multistep biocatalysis. Solvent-tolerant bacteria, especially
Pseudomonas
strains, are proposed as promising hosts to overcome such limitations due to their inherent solvent tolerance mechanisms. However, potential industrial applications suffer from tedious, unproductive adaptation processes, phenotypic variability, and instable solvent-tolerant phenotypes. In this study, genes described to be involved in solvent tolerance were identified in
Pseudomonas
taiwanensis
VLB120, and adaptive solvent tolerance was proven by cultivation in the presence of 1% (vol/vol) toluene. Deletion of
ttgV
, coding for the specific transcriptional repressor of solvent efflux pump TtgGHI gene expression, led to constitutively solvent-tolerant mutants of
P. taiwanensis
VLB120 and VLB120Δ
C
. Interestingly, the increased amount of solvent efflux pumps enhanced not only growth in the presence of toluene and styrene but also the biocatalytic performance in terms of stereospecific styrene epoxidation, although proton-driven solvent efflux is expected to compete with the styrene monooxygenase for metabolic energy. Compared to that of the
P. taiwanensis
VLB120Δ
C
parent strain, the maximum specific epoxidation activity of
P. taiwanensis
VLB120Δ
C
Δ
ttgV
doubled to 67 U/g of cells (dry weight). This study shows that solvent tolerance mechanisms, e.g., the solvent efflux pump TtgGHI, not only allow for growth in the presence of organic compounds but can also be used as tools to improve redox biocatalysis involving organic solvents.
Incorporation of Exogenous Fatty Acids Protects Enterococcus faecalis from Membrane-Damaging Agents
Authors: Saito Holly E. , Harp John R. , Fozo Elizabeth M.
Published: August 2014

Enterococcus faecalis
is a commensal bacterium of the mammalian intestine that can persist in soil and aquatic systems and can be a nosocomial pathogen to humans. It employs multiple stress adaptation strategies in order to survive such a wide range of environments. Within this study, we sought to elucidate whether membrane fatty acid composition changes are an important component for stress adaptation. We noted that
E. faecalis
OG1RF was capable of changing its membrane composition depending upon growth phase and temperature. The organism also readily incorporated fatty acids from bile, serum, and medium supplemented with individual fatty acids, often dramatically changing the membrane composition such that a single fatty acid was predominant. Growth in either low levels of bile or specific individual fatty acids was found to protect the organism from membrane challenges such as high bile exposure. In particular, we observed that when grown in low levels of bile, serum, or the host-derived fatty acids oleic acid and linoleic acid,
E. faecalis
was better able to survive the antibiotic daptomycin. Interestingly, the degree of membrane saturation did not appear to be important for protection from the stressors examined here; instead, it appears that a specific fatty acid or combination of fatty acids is critical for stress resistance.
The Two-Component GacS-GacA System Activates
lipA
Translation by RsmE but Not RsmA in Pseudomonas protegens Pf-5
Authors: Zha Daiming , Xu Li , Zhang Houjin , Yan Yunjun
Published: August 2014

In
Pseudomonas
spp., the Gac-Rsm signal transduction system is required for the production of lipases. The current model assumes that the system induces lipase gene transcription mediated through the quorum-sensing (QS) system. However, there are no reports of a QS system based upon
N
-acyl homoserine lactones or the regulation of lipase gene expression in
Pseudomonas protegens
. In this study, we investigated the regulatory mechanism acting on
lipA
expression activated by the Gac-Rsm system in
P. protegens
Pf-5 through deletion and overexpression of
gacA
, overexpression of
rsmA
or
rsmE
, expression of various
lacZ
fusions, reverse transcription-PCR analysis, and determination of whole-cell lipase activity. The results demonstrated that the GacS-GacA (GacS/A) system activates
lipA
expression at both the transcriptional and the translational levels but that the translational level is the key regulatory pathway. Further results showed that the activation of
lipA
translation by the GacS/A system is mediated through RsmE, which inhibits
lipA
translation by binding to the ACAAGGAUGU sequence overlapping the Shine-Dalgarno (SD) sequence of
lipA
mRNA to hinder the access of the 30S ribosomal subunit to the SD sequence. Moreover, the GacS/A system promotes
lipA
transcription through the mediation of RsmA inhibiting
lipA
transcription via an unknown pathway. Besides the transcriptional repression, RsmA mainly activates
lipA
translation by negatively regulating
rsmE
translation. In summary, in
P. protegens
Pf-5, the Gac-RsmE system mainly and directly activates
lipA
translation and the Gac-RsmA system indirectly enhances
lipA
transcription.
Site-Directed Mutagenesis of the Heterotrimeric Killer Toxin Zymocin Identifies Residues Required for Early Steps in Toxin Action
Authors: Wemhoff Sabrina , Klassen Roland , Meinhardt Friedhelm
Published: August 2014

Zymocin is a
Kluyveromyces lactis
protein toxin composed of αβγ subunits encoded by the cytoplasmic virus-like element k1 and functions by αβ-assisted delivery of the anticodon nuclease (ACNase) γ into target cells. The toxin binds to cells' chitin and exhibits chitinase activity
in vitro
that might be important during γ import.
Saccharomyces cerevisiae
strains carrying k1-derived hybrid elements deficient in either αβ (k1ORF2) or γ (k1ORF4) were generated. Loss of either gene abrogates toxicity, and unexpectedly, Orf2 secretion depends on Orf4 cosecretion. Functional zymocin assembly can be restored by nuclear expression of k1ORF2 or k1ORF4, providing an opportunity to conduct site-directed mutagenesis of holozymocin. Complementation required active site residues of α's chitinase domain and the sole cysteine residue of β (Cys250). Since βγ are reportedly disulfide linked, the requirement for the conserved γ C231 was probed. Toxicity of intracellularly expressed γ C231A indicated no major defect in ACNase activity, while complementation of k1ΔORF4 by γ C231A was lost, consistent with a role of β C250 and γ C231 in zymocin assembly. To test the capability of αβ to carry alternative cargos, the heterologous ACNase from
Pichia acaciae
(
P. acaciae
Orf2 [PaOrf2]) was expressed, along with its immunity gene, in k1ΔORF4. While efficient secretion of PaOrf2 was detected, suppression of the k1ΔORF4-derived k1Orf2 secretion defect was not observed. Thus, the dependency of k1Orf2 on k1Orf4 cosecretion needs to be overcome prior to studying αβ's capability to deliver other cargo proteins into target cells.
Enhanced Uranium Immobilization and Reduction by Geobacter sulfurreducens Biofilms
Authors: Cologgi Dena L. , Speers Allison M. , Bullard Blair A. , Kelly Shelly D. , Reguera Gemma
Published: August 2014

Biofilms formed by dissimilatory metal reducers are of interest to develop permeable biobarriers for the immobilization of soluble contaminants such as uranium. Here we show that biofilms of the model uranium-reducing bacterium
Geobacter sulfurreducens
immobilized substantially more U(VI) than planktonic cells and did so for longer periods of time, reductively precipitating it to a mononuclear U(IV) phase involving carbon ligands. The biofilms also tolerated high and otherwise toxic concentrations (up to 5 mM) of uranium, consistent with a respiratory strategy that also protected the cells from uranium toxicity. The enhanced ability of the biofilms to immobilize uranium correlated only partially with the biofilm biomass and thickness and depended greatly on the area of the biofilm exposed to the soluble contaminant. In contrast, uranium reduction depended on the expression of
Geobacter
conductive pili and, to a lesser extent, on the presence of the
c
cytochrome OmcZ in the biofilm matrix. The results support a model in which the electroactive biofilm matrix immobilizes and reduces the uranium in the top stratum. This mechanism prevents the permeation and mineralization of uranium in the cell envelope, thereby preserving essential cellular functions and enhancing the catalytic capacity of
Geobacter
cells to reduce uranium. Hence, the biofilms provide cells with a physically and chemically protected environment for the sustained immobilization and reduction of uranium that is of interest for the development of improved strategies for the
in situ
bioremediation of environments impacted by uranium contamination.
Physical and Genetic Interaction between Ammonium Transporters and the Signaling Protein Rho1 in the Plant Pathogen Ustilago maydis
Authors: Paul Jinny A. , Barati Michelle T. , Cooper Michael , Perlin Michael H.
Published: August 2014

Dimorphic transitions between yeast-like and filamentous forms occur in many fungi and are often associated with pathogenesis. One of the cues for such a dimorphic switch is the availability of nutrients. Under conditions of nitrogen limitation, fungal cells (such as those of
Saccharomyces cerevisiae
and
Ustilago maydis
) switch from budding to pseudohyphal or filamentous growth. Ammonium transporters (AMTs) are responsible for uptake and, in some cases, for sensing the availability of ammonium, a preferred nitrogen source. Homodimer and/or heterodimer formation may be required for regulating the activity of the AMTs. To investigate the potential interactions of Ump1 and Ump2, the AMTs of the maize pathogen
U. maydis
, we first used the split-ubiquitin system, followed by a modified split-YFP (yellow fluorescent protein) system, to validate the interactions
in vivo
. This analysis showed the formation of homo- and hetero-oligomers by Ump1 and Ump2. We also demonstrated the interaction of the high-affinity ammonium transporter, Ump2, with the Rho1 GTPase, a central protein in signaling, with roles in controlling polarized growth. This is the first demonstration in eukaryotes of the physical interaction
in vivo
of an ammonium transporter with the signaling protein Rho1. Moreover, the Ump proteins interact with Rho1 during the growth of cells in low ammonium concentrations, a condition required for the expression of the Umps. Based on these results and the genetic evidence for the interaction of Ump2 with both Rho1 and Rac1, another small GTPase, we propose a model for the role of these interactions in controlling filamentation, a fundamental aspect of development and pathogenesis in
U. maydis
.
Variation in charges for 10 common blood tests in California hospitals: a cross-sectional analysis
Authors: Hsia Renee Y , Akosa Antwi Yaa , Nath Julia P
Published: August 2014

Objectives

To determine the variation in charges for 10 common blood tests across California hospitals in 2011, and to analyse the hospital and market-level factors that may explain any observed variation.

Design, setting and participants

We conducted a cross-sectional analysis of the degree of charge variation between hospitals for 10 common blood tests using charge data reported by all non-federal California hospitals to the California Office of Statewide Health Planning and Development in 2011.

Outcome measures

Charges for 10 common blood tests at California hospitals during 2011.

Results

We found that charges for blood tests varied significantly between California hospitals. For example, charges for a lipid panel ranged from US$10 to US$10 169, a thousand-fold difference. Although government hospitals and teaching hospitals were found to charge significantly less than their counterparts for many blood tests, few other hospital characteristics and no market-level predictors significantly predicted charges for blood tests. Our models explained, at most, 21% of the variation between hospitals in charges for the blood test in question.

Conclusions

These findings demonstrate the seemingly arbitrary nature of the charge setting process, making it difficult for patients to act as true consumers in this era of ‘consumer-directed healthcare.’
Improving Mental Status Questionnaire (MSQ) completion on admission to the Acute Surgical Receiving Unit (ASRU), Ninewells Hospital, Dundee
Authors: Okwemba Sylvia , Copeland Lauren
Published: August 2014

Delirium is common yet poorly identified in the UK. Early recognition is a key prognostic factor; delay here being associated with: increased mortality, increased morbidity, prolonged hospital stay, long term disability, and increased risk of developing dementia. Improvement in the diagnosis and management of delirium has scope to improve patient care, clinical outcomes, and ultimately an improved patient experience. As patients aged ≥75 years are at an increased risk of developing delirium, we focused the improvement project to this age group.

The baseline data demonstrated that the average ≥75 year-old patient admitted to the Acute Surgical Receiving Unit (ASRU) at Ninewells Hospital had 5.4 out of 12 predisposing and precipitating risk factors for delirium; thus there was great potential for delirium to develop in these patients. During the analysis of the baseline data it became clear that we could not go ahead and implement the initial proposed improvement as the completion of the mental status questionnaire (MSQ) was inconsistent and low at 14.99%. Completion of the MSQ is vital in establishing any cognitive deficit at admission, and for providing a baseline for the continuing admission. As a consequence of this, we had to shift the main aim of the improvement project from improving the identification, diagnosis, and management of delirium, to improving the completion rate of the MSQ in our target age group.

Consultations with members of the admission team were held to determine ways of improving the MSQ completion rate. It became clear that the completion of the MSQ relied on clinical staff remembering all 10 questions that constitute the test. The main intervention to facilitate improvement involved affixing a sticker with all 10 questions of the MSQ within the admissions document. The main aim was to increase the percentage of cognitive screening by the Mental State Questionnaire (MSQ) to 95% in patients aged ≥75 on admission to ASRU at Ninewells Hospital by 11th July 2013.

We achieved our main aim with 100% compliance on two days. Our average compliance over six days was however 81.33%, whilst not reaching our target this is still a substantial improvement. The introduction of the sticker detailing the 10 MSQ questions within the ASRU admissions document was well received by the admissions team. It has simplified the process as members of staff do not need to rely on their memory to remember the questions, and the sticker also acts as a prompt for them to consider further cognitive screening.
Increasing uptake of bowel cancer screening
Authors: Graham Sarah
Published: August 2014

Uptake of bowel cancer screening uptake at our practice is 32.72%, which is below the national target of 60%, but our cancer prevalence and death rate is higher than our CCG statistical mean. We examined reasons for non-response to bowel cancer screening in our patients and explored ways to promote engagement.

From August 2013 to February 2014 we used three interventions in two patient groups: those turning 60 and eligible for screening (rising 60’s) and non-responders to screening. Interventions used were; letter encouragement for rising 60’s, staff education to increase opportunistic promotion of screening and calling non- responders to identify reasons for non-participation and encourage participation. Calls were made by either a Doctor or a Health Care Assistant (HCA); ethnicity, language spoken, caller and call outcome was recorded.

Rising 60’s (n=26) had an uptake of 46%, increased from 32.72%. From the non-responders (n = 73) we were unable to contact 38%, 46% was due to an incorrect or no phone number. Of those contacted main reasons for non-participation were not receiving a screening kit (n=19) and not wanting to be screened (n=14). Following calls 66% of non-responders agreed to screening. From this 66% half (50%) completed screening with a negative result. 15 non-responders refused screening following our calls, the main reason given was not wanting to know if they had cancer (n =14). Calls from doctor and HCA had similar rates of screening uptake (39% and 33% respectively).

Difficulty contacting patients was an unexpected barrier to screening and will be addressed. Actively encouraging screening appears beneficial with similar responses to Doctor and HCA. There appears to be a place for increased education regarding screening and early detection of malignancy amongst patients.

Overall our interventions improved screening uptake at the practice and will be continued in future.
Environmental preferences and constraints of Daphne laureola, an invasive shrub in western Canada
Authors: Lei Thomas
Published: August 2014

Daphne laureola L. is an evergreen forest understory shrub native to the Mediterranean regions of Europe and North Africa that has invaded parts of western North America, including coastal British Columbia (BC) and the states of Washington and Oregon. It can form dense thickets that are likely to prevent the establishment and growth of native plants. Despite its expanding range in the west coast regions, not much is known about its environmental preferences and the ecophysiological attributes associated with its presence and distribution. A 2-year study conducted in Victoria, BC, found that D. laureola attained higher densities in forests with moderate shade at 12%–15% canopy gap opening, whereas densities decreased at higher and lower levels of canopy openness. Specifically, variation in patch density was significantly associated with the level of diffuse light (UOC, uniform overcast sky) and sunfleck duration in the summer, but many leaf-level properties such as photosynthetic rate, leaf dry mass per unit area (LMA), and long-term water use efficiency (as indicated by δ13C) were similar between patches. Taken together, highest plant densities were achieved in forest understory that received less direct but more diffuse sunlight in summer, suggesting that the best growing condition is a compromise between reduced drought stress through lower sunfleck exposure and increased carbon gain under brighter canopies. In future, the high fruit output combined with the readily available seed dispersers seems to ensure that D. laureola will continue to spread, particularly into mainland areas where milder summers may offer a wider range of potential sites for occupation.
A characterization of modules embedding in products of primes and enveloping condition for their class
Authors: Dehghani N. , Vedadi M. R.
Published: August 2014

Modules (cogenerated by nonzero their submodules) having nonzero square homomorphism in nonzero submodules are said (prime) weakly compressible (wc). Such modules are semiprime (i.e. they are cogenerated by their essential submodules). For many rings R, including commutative rings, it is proved that wc modules are isomorphic submodules of products of prime modules, and the converse holds precisely when the class of wc modules is enveloping for mod-R or equivalently, every semiprime module is wc. Semi-Artinian rings R have the latter property and the converse is true when R is strongly regular. Duo Noetherian rings over which wc modules form an enveloping class are shown to have a finite number maximal ideals. If R is Morita equivalent to a Dedekind domain, then the class of wc R-modules is enveloping if and only if R is simple Artinian or J (R) ≠ 0.
Hyperbilirubinemia modulates myocardial function, aortic ejection, and ischemic stress resistance in the Gunn rat
Authors: Bakrania Bhavisha , Du Toit Eugene F. , Ashton Kevin J. , Kiessling Can J. , Wagner Karl-Heinz , Headrick John P. , Bulmer Andrew C.
Published: August 2014

Mildly elevated circulating unconjugated bilirubin (UCB) is associated with protection against hypertension and ischemic heart disease. We assessed whether endogenously elevated bilirubin in Gunn rats modifies cardiovascular function and resistance to ischemic insult. Hearts were assessed ex vivo (Langendorff perfusion) and in vivo (Millar catheterization and echocardiography), and left ventricular myocardial gene expression was measured via quantitative real-time PCR. Ex vivo analysis revealed reduced intrinsic contractility in the Gunn myocardium (+dP/d t: 1,976 ± 622 vs. 2,907 ± 334 mmHg/s, P < 0.01; −dP/d t: −1,435 ± 372 vs. −2,234 ± 478 mmHg/s, P < 0.01), which correlated positively with myocardial UCB concentration ( P < 0.05). In vivo analyses showed no changes in left ventricular contractile parameters and ejection (fractional shortening and ejection fraction). However, Gunn rats exhibited reductions in the rate of aortic pressure development (3,008 ± 461 vs. 4,452 ± 644 mmHg/s, P < 0.02), mean aortic velocity (439 ± 64 vs. 644 ± 62 mm/s, P < 0.01), and aortic volume time integral pressure gradient (2.32 ± 0.65 vs. 5.72 ± 0.74 mmHg, P < 0.01), in association with significant aortic dilatation (12–24% increase in aortic diameter, P < 0.05). Ex vivo Gunn hearts exhibited improved ventricular function after 35 min of ischemia and 90 min of reperfusion (63 ± 14 vs. 35 ± 12%, P < 0.01). These effects were accompanied by increased glutathione peroxidase and reduced superoxide dismutase and phospholamban gene expression in Gunn rat myocardium ( P < 0.05). These data collectively indicate that hyperbilirubinemia in Gunn rats 1) reduces intrinsic cardiac contractility, which is compensated for in vivo; 2) induces aortic dilatation, which may beneficially influence aortic ejection velocities and pressures; and 3) may improve myocardial stress resistance in association with beneficial transcriptional changes. These effects may contribute to protection from cardiovascular disease with elevated bilirubin.
Regulatory T cells are recruited in the infarcted mouse myocardium and may modulate fibroblast phenotype and function
Authors: Saxena Amit , Dobaczewski Marcin , Rai Vikrant , Haque Zaffar , Chen Wei , Li Na , Frangogiannis Nikolaos G.
Published: August 2014

Regulatory T cells (Tregs) play a pivotal role in suppressing immune responses regulating behavior and gene expression in effector T cells, macrophages, and dendritic cells. Tregs infiltrate the infarcted myocardium; however, their role the inflammatory and reparative response after myocardial infarction remains poorly understood. We used FoxP3EGFP reporter mice to study Treg trafficking in the infarcted heart and examined the effects of Treg depletion on postinfarction remodeling using an anti-CD25 antibody. Moreover, we investigated the in vitro effects of Tregs on cardiac fibroblast phenotype and function. Low numbers of Tregs infiltrated the infarcted myocardium after 24–72 h of reperfusion. Treg depletion had no significant effects on cardiac dysfunction and scar size after reperfused myocardial infarction but accelerated ventricular dilation and accentuated apical remodeling. Enhanced myocardial dilation in Treg-depleted animals was associated with increased expression of chemokine (C-C motif) ligand 2 and accentuated macrophage infiltration. In vitro, Tregs modulated the cardiac fibroblast phenotype, reducing expression of α-smooth muscle actin, decreasing expression of matrix metalloproteinase-3, and attenuating contraction of fibroblast-populated collagen pads. Our findings suggest that endogenous Tregs have modest effects on the inflammatory and reparative response after myocardial infarction. However, the anti-inflammatory and matrix-preserving properties of Tregs may suggest a role for Treg-based cell therapy in the attenuation of adverse postinfarction remodeling.
Myofilament dysfunction contributes to impaired myocardial contraction in the infarct border zone
Authors: Shimkunas Rafael , Makwana Om , Spaulding Kimberly , Bazargan Mona , Khazalpour Michael , Takaba Kiyoaki , Soleimani Mehrdad , Myagmar Bat-Erdene , Lovett David H. , Simpson Paul C. , Ratcliffe Mark B. , Baker Anthony J.
Published: August 2014

After myocardial infarction, a poorly contracting nonischemic border zone forms adjacent to the infarct. The cause of border zone dysfunction is unclear. The goal of this study was to determine the myofilament mechanisms involved in postinfarction border zone dysfunction. Two weeks after anteroapical infarction of sheep hearts, we studied in vitro isometric and isotonic contractions of demembranated myocardium from the infarct border zone and a zone remote from the infarct. Maximal force development (Fmax) of the border zone myocardium was reduced by 31 ± 2% versus the remote zone myocardium ( n = 6/group, P < 0.0001). Decreased border zone Fmax was not due to a reduced content of contractile material, as assessed histologically, and from myosin content. Furthermore, decreased border zone Fmax did not involve altered cross-bridge kinetics, as assessed by muscle shortening velocity and force development kinetics. Decreased border zone Fmax was associated with decreased cross-bridge formation, as assessed from muscle stiffness in the absence of ATP where cross-bridge formation should be maximized (rigor stiffness was reduced 34 ± 6%, n = 5, P = 0.011 vs. the remote zone). Furthermore, the border zone myocardium had significantly reduced phosphorylation of myosin essential light chain (ELC; 41 ± 10%, n = 4, P < 0.05). However, for animals treated with doxycycline, an inhibitor of matrix metalloproteinases, rigor stiffness and ELC phosphorylation were not reduced in the border zone myocardium, suggesting that doxycycline had a protective effect. In conclusion, myofilament dysfunction contributes to postinfarction border zone dysfunction, myofilament dysfunction involves impaired cross-bridge formation and decreased ELC phosphorylation, and matrix metalloproteinase inhibition may be beneficial for limiting postinfarct border zone dysfunction.
Prolonged uterine artery nitric oxide synthase inhibition modestly alters basal uteroplacental vasodilation in the last third of ovine pregnancy
Authors: Rosenfeld Charles R. , Roy Timothy
Published: August 2014

Mechanisms regulating uteroplacental blood flow (UPBF) in pregnancy remain unclear, but they likely involve several integrated signaling systems. Endothelium-derived nitric oxide (NO) is considered an important contributor, but the extent of its involvement is unclear. Bolus intra-arterial infusions of nitro-l-arginine methyl ester (l-NAME) modestly decrease ovine basal UPBF; however, the doses and duration of infusion may have been insufficient. We, therefore, examined prolonged uterine artery (UA) NO synthase inhibition with l-NAME throughout the last third of ovine pregnancy by performing either continuous 30-min UA infusion dose responses ( n = 4) or 72-h UA infusions (0.01 mg/ml) at 104–108, 118–125, and 131–137 days of gestation ( n = 7) while monitoring mean arterial pressure (MAP), heart rate (HR), and UPBF. Uteroplacental vascular resistance (UPVR) was calculated, and uterine cGMP synthesis was measured. Thirty-minute UA l-NAME infusions did not dose dependently decrease UPBF, increase UPVR, or decrease uterine cGMP synthesis ( P > 0.1); however, MAP rose and HR fell modestly. Prolonged continuous 72-h UA l-NAME infusions decreased UPBF ∼32%, increased UPVR ∼68% ( P ≤ 0.001), and decreased uterine cGMP synthesis 70% at 54–72 h ( P ≤ 0.004); the noninfused uterine horn was unaffected. These findings were associated with ∼10% increases in MAP and decreases in HR that were greater at 104–108 than 118–125 and 131–137 days of gestation ( P = 0.006). Although uterine and UA NO and cGMP synthesis increase severalfold during ovine pregnancy, they contribute modestly to the maintenance and rise in UPBF in the last third of gestation. Thus, local UA NO may primarily modulate vasoconstrictor responses. Notably, the systemic vasculature appears more sensitive than the uterine vasculature to NO synthase inhibition.
PKG-1α leucine zipper domain defect increases pulmonary vascular tone: implications in hypoxic pulmonary hypertension
Authors: Ramchandran Ramaswamy , Raghavan Aarti , Geenen David , Sun Miranda , Bach Laura , Yang Qiwei , Raj J. Usha
Published: August 2014

Pulmonary hypertension (PH) is a chronic disease characterized by a progressive increase in vasomotor tone, narrowing of the vasculature with structural remodeling, and increase in pulmonary vascular resistance. Current treatment strategies include nitric oxide therapy and methods to increase cGMP-mediated vasodilatation. cGMP-dependent protein kinases (PKG) are known mediators of nitric oxide- and cGMP-induced vasodilatation. Deletion of PKG-1 in mice has been shown to induce PH, however, the exact mechanisms by which loss of PKG-1 function leads to PH is not known. In a mouse model with a selective mutation in the NH2-terminus leucine zipper protein interaction domain of PKG-1α [leucine zipper mutant (LZM)], we found a progressive increase in right ventricular systolic pressure and right heart hypertrophy compared with wild-type (WT) mice and increased RhoA-GTPase activity in the lungs. When exposed to chronic hypoxia, LZM mice developed modestly enhanced right ventricular remodeling compared with WT mice. Tadalafil, a phosphodiesterase-5 inhibitor that increases cGMP levels, significantly attenuated hypoxia-induced cardiopulmonary remodeling in WT mice but had no effect in LZM mice. We conclude that a functional leucine zipper domain in PKG-1α is essential for maintenance of a low pulmonary vascular tone in normoxia and for cGMP-mediated beneficial effects of phosphodiesterase-5 inhibition in hypoxic cardiopulmonary remodeling.
Role of hypoxia-induced transglutaminase 2 in pulmonary artery smooth muscle cell proliferation
Authors: Penumatsa Krishna C. , Toksoz Deniz , Warburton Rod R. , Hilmer Andrew J. , Liu Tiegang , Khosla Chaitan , Comhair Suzy A. A. , Fanburg Barry L.
Published: August 2014

We previously reported that transglutaminase 2 (TG2) activity is markedly elevated in lungs of hypoxia-exposed rodent models of pulmonary hypertension (PH). Since vascular remodeling of pulmonary artery smooth muscle cells (PASMCs) is important in PH, we undertook the present study to determine whether TG2 activity is altered in PASMCs with exposure to hypoxia and whether that alteration participates in their proliferative response to hypoxia. Cultured distal bovine (b) and proximal human (h) PASMCs were exposed to hypoxia (3% O2) or normoxia (21% O2). mRNA and protein expression were determined by PCR and Western blot analyses. TG2 activity and function were visualized and determined by fluorescent labeled 5-pentylamine biotin incorporation and immunoblotting of serotonylated fibronectin. Cell proliferation was assessed by [3H]thymidine incorporation assay. At 24 h, both TG2 expression and activity were stimulated by hypoxia in bPASMCs. Activation of TG2 by hypoxia was blocked by inhibition of the extracellular calcium-sensing receptor or the transient receptor potential channel V4. In contrast, TG2 expression was blocked by inhibition of the transcription factor hypoxia-inducible factor-1α, supporting the presence of separate mechanisms for stimulation of activity and expression of TG2. Pulmonary arterial hypertension patient-derived hPASMCs were found to proliferate significantly more rapidly and respond to hypoxia more strongly than control-derived hPASMCs. Similar to bovine cells, hypoxia-induced proliferation of patient-derived cells was blocked by inhibition of TG2 activity. Our results suggest an important role for TG2, mediated by intracellular calcium fluxes and HIF-1α, in hypoxia-induced PASMC proliferation and possibly in vascular remodeling in PH.
Real-time monitoring of endogenous lipid peroxidation by exhaled ethylene in patients undergoing cardiac surgery
Authors: Cristescu Simona M. , Kiss Rudolf , te Lintel Hekkert Sacco , Dalby Miles , Harren Frans J. M. , Risby Terence H. , Marczin Nandor
Published: August 2014

Pulmonary and systemic organ injury produced by oxidative stress including lipid peroxidation is a fundamental tenet of ischemia-reperfusion injury, inflammatory response to cardiac surgery, and cardiopulmonary bypass (CPB) but is not routinely measured in a surgically relevant time frame. To initiate a paradigm shift toward noninvasive and real-time monitoring of endogenous lipid peroxidation, we have explored pulmonary excretion and dynamism of exhaled breath ethylene during cardiac surgery to test the hypothesis that surgical technique and ischemia-reperfusion triggers lipid peroxidation. We have employed laser photoacoustic spectroscopy to measure real-time trace concentrations of ethylene from the patient breath and from the CPB machine. Patients undergoing aortic or mitral valve surgery-requiring CPB ( n = 15) or off-pump coronary artery bypass surgery (OPCAB) ( n = 7) were studied. Skin and tissue incision by diathermy caused striking (>30-fold) increases in exhaled ethylene resulting in elevated levels until CPB. Gaseous ethylene in the CPB circuit was raised upon the establishment of CPB (>10-fold) and decreased over time. Reperfusion of myocardium and lungs did not appear to enhance ethylene levels significantly. During OPCAB surgery, we have observed increased ethylene in 16 of 30 documented reperfusion events associated with coronary and aortic anastomoses. Therefore, novel real-time monitoring of endogenous lipid peroxidation in the intraoperative setting provides unparalleled detail of endogenous and surgery-triggered production of ethylene. Diathermy and unprotected regional myocardial ischemia and reperfusion are the most significant contributors to increased ethylene.
Optimization of Process Parameters of Stamping Forming of the Automotive Lower Floor Board
Authors: Ma Guoying , Huang Binbing
Published: August 2014

There are many process parameters which have great effect on the forming quality of parts during automobile panel stamping forming process. This paper took automotive lower floor board as the research object; the forming process was analyzed by finite element simulation using Dynaform. The influences of four main process parameters including BHF (blank holder force), die corner radius, friction coefficient, and die clearance on the maximum thinning rate and the maximum thickening rate were researched based on orthogonal experiment. The results show that the influences of each value of various factors on the target are not identical. On this basis, the optimization of the four parameters was carried out, and the high quality product was obtained and the maximum thinning rate and maximum thickening rate were effectively controlled. The results also show that the simulation analysis provides the basis for the optimization of the forming process parameters, and it can greatly shorten the die manufacturing cycles, reduce the production costs, and improve the production efficiency.
The Almost Sure Asymptotic Stability and Boundedness of Stochastic Functional Differential Equations with Polynomial Growth Condition
Authors: Feng Lichao , Li Shoumei
Published: August 2014

Stability and boundedness are two of the most important topics in the study of stochastic functional differential equations (SFDEs). This paper mainly discusses the almost sure asymptotic stability and the boundedness of nonlinear SFDEs satisfying the local Lipschitz condition but not the linear growth condition. Here we assume that the coefficients of SFDEs are polynomial or dominated by polynomial functions. We give sufficient criteria on the almost sure asymptotic stability and the boundedness for this kind of nonlinear SFDEs. Some nontrivial examples are provided to illustrate our results.
Phenotypic Switch Induced by Simulated Microgravity on MDA-MB-231 Breast Cancer Cells
Authors: Masiello Maria Grazia , Cucina Alessandra , Proietti Sara , Palombo Alessandro , Coluccia Pierpaolo , D’Anselmi Fabrizio , Dinicola Simona , Pasqualato Alessia , Morini Veronica , Bizzarri Mariano
Published: August 2014

Microgravity exerts dramatic effects on cell morphology and functions, by disrupting cytoskeleton and adhesion structures, as well as by interfering with biochemical pathways and gene expression. Impairment of cells behavior has both practical and theoretical significance, given that investigations of mechanisms involved in microgravity-mediated effects may shed light on how biophysical constraints cooperate in shaping complex living systems. By exposing breast cancer MDA-MB-231 cells to simulated microgravity (~0.001 g), we observed the emergence of two morphological phenotypes, characterized by distinct membrane fractal values, surface area, and roundness. Moreover, the two phenotypes display different aggregation profiles and adherent behavior on the substrate. These morphological differences are mirrored by the concomitant dramatic functional changes in cell processes (proliferation and apoptosis) and signaling pathways (ERK, AKT, and Survivin). Furthermore, cytoskeleton undergoes a dramatic reorganization, eventually leading to a very different configuration between the two populations. These findings could be considered adaptive and reversible features, given that, by culturing microgravity-exposed cells into a normal gravity field, cells are enabled to recover their original phenotype. Overall these data outline the fundamental role gravity plays in shaping form and function in living systems.
Modeling and Implementing Two-Stage AdaBoost for Real-Time Vehicle License Plate Detection
Authors: Song Moon Kyou , Sarker Md. Mostafa Kamal
Published: August 2014

License plate (LP) detection is the most imperative part of the automatic LP recognition system. In previous years, different methods, techniques, and algorithms have been developed for LP detection (LPD) systems. This paper proposes to automatical detection of car LPs via image processing techniques based on classifier or machine learning algorithms. In this paper, we propose a real-time and robust method for LPD systems using the two-stage adaptive boosting (AdaBoost) algorithm combined with different image preprocessing techniques. Haar-like features are used to compute and select features from LP images. The AdaBoost algorithm is used to classify parts of an image within a search window by a trained strong classifier as either LP or non-LP. Adaptive thresholding is used for the image preprocessing method applied to those images that are of insufficient quality for LPD. This method is of a faster speed and higher accuracy than most of the existing methods used in LPD. Experimental results demonstrate that the average LPD rate is 98.38% and the computational time is approximately 49 ms.
Correlated Analytic Hierarchy Process
Authors: Liu Hsiang-Hsi , Yeh Yeong-Yuh , Huang Jih-Jeng
Published: August 2014

The analytic hierarchy process (AHP) has been the most popular tool for the field of decision making in the past 30 years, because of its simplicity and rationality. Construct a hierarchy system for evaluation by decision makers. Hence, only the effect of outer‐dependence can be considered in the AHP. However, besides outer‐dependence, correlation is another common effect between criteria which cannot be accounted for neither by the AHP nor by the analytic network process (ANP). Hence, in this paper, we extend the AHP to consider the correlation effect. In addition, a biobjective programming model is proposed to derive the result. Furthermore, the traditional AHP can be considered as the special case of the proposed model when the correlation effect between criteria is ignored. Finally, a numerical example is given to justify the proposed method and compare the result with the AHP.
National Trends and Disparities in Cervical Cancer Screening among Commercially Insured Women, 2001–2010
Authors: Wharam J. Frank , Zhang Fang , Xu Xin , Landon Bruce E. , Ross-Degnan Dennis
Published: August 2014

Background: Previous surveys reported declining cervical cancer screening rates from 2000 to 2010, but trends by key demographic and age groups are less clear.

Methods: We examined 3-year Papanicolaou (Pap) test rates among 4.2 million women enrolled in a large national health plan during 2001 to 2010. We calculated and plotted adjusted 3-year rates stratified by age and key neighborhood-level socioeconomic characteristics including poverty level and race/ethnicity (white, black, Hispanic, and mixed ethnicity neighborhood). We fitted trends in 2001–2010 screening rates and socioeconomic disparities as annual percentage changes (APC) using joinpoint analysis.

Results: Women ages 21 to 29 years had estimated 3-year Pap testing rates of 81.3% to 81.4% over the decade. Estimated disparities by low–high poverty level were 3.1% and 2.0% in 2001–2003 and 2008–2010, respectively, a nonsignificant decline. Initial white–black disparities were 4.0% and declined significantly from 2005–2007 to 2008–2010 to 2.8% at an APC of −0.65% (P = 0.021). White–Hispanic disparities declined from 4.3% to 0.8% over the decade, a −0.50% APC (P = 0.024). Among women ages 30 to 64 years, estimated 3-year Pap testing rates trended down from 76.1% to 71.8% over the decade [−0.94% APC (P < 0.001) until 2005–2007]. This pattern was similar among women from most categories of poverty and race/ethnicity.

Conclusions: Among commercially insured women ages 21 to 29 years, 3-year Pap testing rates remained stable at 81% over the decade; disparities were small and improved for Hispanic women to a greater degree than for black women. Among women ages 30 to 64 years, 3-year Pap testing rates declined from 2001 to 2010.

Impact: Cervical cancer screening should be promoted to achieve Healthy People 2020 goals. Cancer Epidemiol Biomarkers Prev; 23(11); 2366–73. ©2014 AACR.
Prospective Study of Seroreactivity to JC Virus T-Antigen and Risk of Colorectal Cancers and Adenomas
Authors: Hampras Shalaka S. , Viscidi Raphael P. , Helzlsouer Kathy J. , Lee Ji-Hyun , Fulp William J. , Giuliano Anna R. , Platz Elizabeth A. , Rollison Dana E.
Published: August 2014

John Cunningham virus (JCV) is a common polyomavirus classified as a possible carcinogen by the International Agency for Research on Cancer. JCV may play a role in colorectal carcinogenesis, although we previously reported no association between JCV capsid antibodies and colorectal cancer. No studies have examined the role of seroreactivity to JCV T-antigen (T-Ag) oncoprotein in colorectal cancer. A case–control study nested within a community-based prospective cohort (CLUE II) was conducted. In 1989, 25,080 residents of Washington County, Maryland, were enrolled in CLUE II, completing baseline questionnaires and providing blood samples. At follow-up, 257 incident colorectal cancer cases were identified by linkage to population-based cancer registries through 2006 and matched to controls on age, sex, race, and date of blood draw. One hundred and twenty-three colorectal adenoma cases were identified through self-report during follow-up and matched to controls on age, sex, race, date of blood draw, and colorectal cancer screening. Baseline serum samples were tested for seroreactivity to JCV T-Ag. Associations between JCV T-Ag seroreactivity and colorectal cancer/adenomas were evaluated using conditional logistic regression models. Overall, seroreactivity to JCV T-Ag was not statistically significantly associated with the risk of either colorectal cancer [OR, 1.34; 95% confidence interval (CI), 0.89–2.01] or adenoma (OR, 1.30; 95% CI, 0.70–2.42), while a borderline association with colorectal cancer was observed among women (OR, 1.82; 95% CI, 1.00–3.31). Our past evaluation of JCV capsid seropositivity, combined with current findings, does not support a notable etiologic role for JCV infection in colorectal cancer. Cancer Epidemiol Biomarkers Prev; 23(11); 2591–6. ©2014 AACR.