bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ObjectivesTo 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 participantsWe 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 measuresCharges for 10 common blood tests at California hospitals during 2011.ResultsWe 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.ConclusionsThese 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

AbstractDelirium 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

AbstractUptake 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.
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

Abstract
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 &lt; 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

AbstractJohn 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.
Improved Stool DNA Integrity Method for Early Colorectal Cancer Diagnosis
Authors: Rengucci Claudia , De Maio Giulia , Menghi Maura , Scarpi Emanuela , Guglielmo Simona , Fusaroli Pietro , Caletti Giancarlo , Saragoni Luca , Gardini Andrea Casadei , Zoli Wainer , Falcini Fabio , Amadori Dino , Calistri Daniele 
Published: August 2014

AbstractBackground: DNA integrity analysis could represent an alternative approach to the early detection of colorectal cancer. Previously, fluorescence long DNA (FL-DNA) in stools was extracted using a manual approach and analyzed by capillary electrophoresis assay (CE FL-DNA). We aimed to improve diagnostic accuracy using a simpler and more standardized method [Real Time PCR FL-DNA (RT FL-DNA)] for the detection of early malignant lesions in a population undergoing colorectal cancer screening.Methods: From 241 stool samples, DNA was extracted using manual and semiautomatic extraction systems and analyzed using FL-DNA tests by CE and RT assays. The RT FL-DNA approach showed slightly higher sensitivity and specificity compared with the CE FL-DNA method. Furthermore, we compared the RT FL-DNA approach with the iFOBT report.Results: Nonparametric ranking statistics were used to analyze the relationship between the median values of RT FL-DNA and the clinicohistopathologic characteristics. The median values of both variables were significantly higher in patients with cancer than in patients with noncancerous lesions. According to the Fagan nomogram results, the iFOBT and FL-DNA methods provided more accurate diagnostic information and were able to identify subgroups at varying risks of cancer.Conclusions: The combination of the semiautomatic extraction system and RT FL-DNA analysis improved the quality of DNA extracted from stool samples.Impact: RT FL-DNA shows great potential for colorectal cancer diagnosis as it is a reliable and relatively easy analysis to perform on routinely processed stool samples in combination with iFOBT. Cancer Epidemiol Biomarkers Prev; 23(11); 2553–60. ©2014 AACR.