bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anatomical background noise power spectrum in differential phase contrast and dark field contrast mammograms
Authors: Garrett John , Ge Yongshuai , Li Ke , Chen Guang‐Hong 
Published: November 2014

Purpose:In x‐ray absorption mammography, it has been found that the anatomical background noise can be characterized by a power law dependence on the spatial frequency, NPSa(f) ≈ αf−β. In this letter, the authors present the first experimental results of the corresponding exponents, β, for differential phase contrast (βDPC) and dark field contrast (βDF) mammography.Methods:A grating‐based x‐ray multicontrast imaging acquisition benchtop system was used to simultaneously acquire mammograms with three different contrast mechanisms from 15 cadaver breasts under the same x‐ray data acquisition conditions. The cadaver breasts were imaged in the coronal plane. The authors’ experimental implementation of the well documented method [Burgess, Jacobson, and Judy, Med. Phys. 28, 419–437 (2001)] to extract the exponent β was first validated using anonymized clinical mammograms. Experiments were then used to determine β for the three types of mammograms for each cadaver breast acquired with our multicontrast imaging system: absorption contrast mammogram (βAbs.), differential phase contrast mammogram (βDPC), and dark‐field contrast mammogram (βDF).Results:The measured β values, acquired in the coronal plane with the benchtop multicontrast imaging system are βAbs. = 3.61 ± 0.49, βDPC = 2.54 ± 0.75, and βDF = 1.44 ± 0.49 for absorption, differential phase, and dark field mammogram, respectively.Conclusions:The β values for differential phase contrast and dark field mammography are significantly lower than the measured value of β for the corresponding absorption contrast mammograms. The greatly reduced β value of the anatomical background noise in differential phase contrast and dark field mammograms may suggest potentially improved diagnostic performance for certain types of breast cancer imaging tasks.
Radiotherapy beyond cancer: Target localization in real‐time MRI and treatment planning for cardiac radiosurgery
Authors: Ipsen S. , Blanck O. , Oborn B. , Bode F. , Liney G. , Hunold P. , Rades D. , Schweikard A. , Keall P. J. 
Published: November 2014

Purpose:Atrial fibrillation (AFib) is the most common cardiac arrhythmia that affects millions of patients world‐wide. AFib is usually treated with minimally invasive, time consuming catheter ablation techniques. While recently noninvasive radiosurgery to the pulmonary vein antrum (PVA) in the left atrium has been proposed for AFib treatment, precise target location during treatment is challenging due to complex respiratory and cardiac motion. A MRI linear accelerator (MRI‐Linac) could solve the problems of motion tracking and compensation using real‐time image guidance. In this study, the authors quantified target motion ranges on cardiac magnetic resonance imaging (MRI) and analyzed the dosimetric benefits of margin reduction assuming real‐time motion compensation was applied.Methods:For the imaging study, six human subjects underwent real‐time cardiac MRI under free breathing. The target motion was analyzed retrospectively using a template matching algorithm. The planning study was conducted on a CT of an AFib patient with a centrally located esophagus undergoing catheter ablation, representing an ideal case for cardiac radiosurgery. The target definition was similar to the ablation lesions at the PVA created during catheter treatment. Safety margins of 0 mm (perfect tracking) to 8 mm (untracked respiratory motion) were added to the target, defining the planning target volume (PTV). For each margin, a 30 Gy single fraction IMRT plan was generated. Additionally, the influence of 1 and 3 T magnetic fields on the treatment beam delivery was simulated using Monte Carlo calculations to determine the dosimetric impact of MRI guidance for two different Linac positions.Results:Real‐time cardiac MRI showed mean respiratory target motion of 10.2 mm (superior–inferior), 2.4 mm (anterior–posterior), and 2 mm (left–right). The planning study showed that increasing safety margins to encompass untracked respiratory motion leads to overlapping structures even in the ideal scenario, compromising either normal tissue dose constraints or PTV coverage. The magnetic field caused a slight increase in the PTV dose with the in‐line MRI‐Linac configuration.Conclusions:The authors’ results indicate that real‐time tracking and motion compensation are mandatory for cardiac radiosurgery and MRI‐guidance is feasible, opening the possibility of treating cardiac arrhythmia patients completely noninvasively.
Dissemination of NDM Metallo-β-Lactamase Genes among Clinical Isolates of Enterobacteriaceae Collected during the SMART Global Surveillance Study from 2008 to 2012
Authors: Biedenbach D. , Bouchillon S. , Hackel M. , Hoban D. , Kazmierczak K. , Hawser S. , Badal R. 
Published: November 2014

ABSTRACT

The prevalence of carbapenemase enzymes continues to increase. Among the Ambler class B enzymes is the New Delhi metallo-β-lactamase (NDM). This particular enzyme is capable of hydrolyzing nearly all β-lactam antimicrobial agents and has spread rapidly, becoming a global problem. Therapeutic treatment options for patients infected with isolates which produce this enzyme are difficult to manage, as cross-resistance to other antimicrobial classes is common. The Study for Monitoring Antimicrobial Resistance Trends (SMART) is a global surveillance study evaluating the antimicrobial susceptibilities of numerous Gram-negative bacterial species recovered from people with intra-abdominal and urinary tract infections. The Clinical and Laboratory Standards Institute methods and a molecular analysis identified 134 isolates of
Enterobacteriaceae
(nine species) and one
Acinetobacter
sp. with
bla
NDM
genes. These isolates were collected in nine countries, and >95% of the isolates possessed the NDM-1 variant. The MIC
90
values were >4 mg/liter and >8 mg/liter for ertapenem and imipenem, respectively. No tested β-lactam or β-lactamase inhibitor combination had activity against these isolates. Resistance to amikacin (79.9%) and levofloxacin (82.8%) was common. Nearly all the isolates encoded additional enzymes, including AmpC cephalosporinases and extended-spectrum β-lactamases. There is an urgent need for infection control and continued global monitoring of isolates which harbor the NDM enzyme, as evidenced by recent outbreaks.
A Cell-Based Strategy To Assess Intrinsic Inhibition Efficiencies of HIV-1 Reverse Transcriptase Inhibitors
Authors: Abram Michael E. , Tsiang Manuel , White Kirsten L. , Callebaut Christian , Miller Michael D. 
Published: November 2014

ABSTRACTDuring HIV-1 reverse transcription, there are increasing opportunities for nucleos(t)ide (NRTI) or nonnucleoside (NNRTI) reverse transcriptase (RT) inhibitors to stop elongation of the nascent viral DNA (vDNA). In addition, RT inhibitors appear to influence the kinetics of vDNA synthesis differently. While cell-free kinetic inhibition constants have provided detailed mechanistic insight, these assays are dependent on experimental conditions that may not mimic the cellular milieu. Here we describe a novel cell-based strategy to provide a measure of the intrinsic inhibition efficiencies of clinically relevant RT inhibitors on a per-stop-site basis. To better compare inhibition efficiencies among HIV-1 RT inhibitors that can stop reverse transcription at any number of different stop sites, their basic probability,p, of getting stopped at any potential stop site was determined. A relationship between qPCR-derived 50% effective inhibitory concentrations (EC50s) and this basic probability enabled determination ofpby successive approximation. On a per-stop-site basis, tenofovir (TFV) exhibited 1.4-fold-greater inhibition efficiency than emtricitabine (FTC), and as a class, both NRTIs exhibited an 8- to 11-fold greater efficiency than efavirenz (EFV). However, as more potential stops sites were considered, the probability of reverse transcription failing to reach the end of the template approached equivalence between both classes of RT inhibitors. Overall, this novel strategy provides a quantitative measure of the intrinsic inhibition efficiencies of RT inhibitors in the natural cellular milieu and thus may further understanding of drug efficacy. This approach also has applicability for understanding the impact of viral polymerase-based inhibitors (alone or in combination) in other virus systems.
Role of Anaerobiosis in Capsule Production and Biofilm Formation in Vibrio vulnificus
Authors: Phippen Britney L. , Oliver James D. 
Published: November 2014

ABSTRACT

Vibrio vulnificus
, a pervasive human pathogen, can cause potentially fatal septicemia after consumption of undercooked seafood. Biotype 1 strains of
V. vulnificus
are most commonly associated with human infection and are separated into two genotypes, clinical (C) and environmental (E), based on the virulence-correlated gene. For ingestion-based vibriosis to occur, this bacterium must be able to withstand multiple conditions as it traverses the gastrointestinal tract and ultimately gains entry into the bloodstream. One such condition, anoxia, has yet to be extensively researched in
V. vulnificus
. We investigated the effect of oxygen availability on capsular polysaccharide (CPS) production and biofilm formation in this bacterium, both of which are thought to be important for disease progression. We found that lack of oxygen elicits a reduction in both CPS and biofilm formation in both genotypes. This is further supported by the finding that
pilA
,
pilD
, and
mshA
genes, all of which encode type IV pilin proteins that aid in attachment to surfaces, were downregulated during anaerobiosis. Surprisingly, E-genotypes exhibited distinct differences in gene expression levels of capsule and attachment genes compared to C-genotypes, both aerobically and anaerobically. The importance of understanding these disparities may give insight into the observed differences in environmental occurrence and virulence potential between these two genotypes of
V. vulnificus
.
Staphylococcus epidermidis SrrAB Regulates Bacterial Growth and Biofilm Formation Differently under Oxic and Microaerobic Conditions
Authors: Wu Youcong , Wu Yang , Zhu Tao , Han Haiyan , Liu Huayong , Xu Tao , Francois Patrice , Fischer Adrien , Bai Li , Götz Friedrich , Qu Di 
Published: November 2014

ABSTRACT

SrrAB expression in
Staphylococcus epidermidis
strain 1457 (SE1457) was upregulated during a shift from oxic to microaerobic conditions. An
srrA
deletion (Δ
srrA
) mutant was constructed for studying the regulatory function of SrrAB. The deletion resulted in retarded growth and abolished biofilm formation both
in vitro
and
in vivo
and under both oxic and microaerobic conditions. Associated with the reduced biofilm formation, the Δ
srrA
mutant produced much less polysaccharide intercellular adhesion (PIA) and showed decreased initial adherence capacity. Microarray analysis showed that the
srrA
mutation affected transcription of 230 genes under microaerobic conditions, and 51 genes under oxic conditions. Quantitative real-time PCR confirmed this observation and showed downregulation of genes involved in maintaining the electron transport chain by supporting cytochrome and quinol-oxidase assembly (e.g.,
qoxB
and
ctaA
) and in anaerobic metabolism (e.g.,
pflBA
and
nrdD
). In the Δ
srrA
mutant, the expression of the biofilm formation-related gene
icaR
was upregulated under oxic conditions and downregulated under microaerobic conditions, whereas
icaA
was downregulated under both conditions. An electrophoretic mobility shift assay further revealed that phosphorylated SrrA bound to the promoter regions of
icaR
,
icaA
,
qoxB
, and
pflBA
, as well as its own promoter region. These findings demonstrate that in
S. epidermidis
SrrAB is an autoregulator and regulates biofilm formation in an
ica
-dependent manner. Under oxic conditions, SrrAB modulates electron transport chain activity by positively regulating
qoxBACD
transcription. Under microaerobic conditions, it regulates fermentation processes and DNA synthesis by modulating the expression of both the
pfl
operon and
nrdDG
.
Contemporary Avian Influenza A Virus Subtype H1, H6, H7, H10, and H15 Hemagglutinin Genes Encode a Mammalian Virulence Factor Similar to the 1918 Pandemic Virus H1 Hemagglutinin
Authors: Qi Li , Pujanauski Lindsey M. , Davis A. Sally , Schwartzman Louis M. , Chertow Daniel S. , Baxter David , Scherler Kelsey , Hartshorn Kevan L. , Slemons Richard D. , Walters Kathie-Anne , Kash John C. , Taubenberger Jeffery K. 
Published: November 2014

ABSTRACT
Zoonotic avian influenza virus infections may lead to epidemics or pandemics. The 1918 pandemic influenza virus has an avian influenza virus-like genome, and its H1 hemagglutinin was identified as a key mammalian virulence factor. A chimeric 1918 virus expressing a contemporary avian H1 hemagglutinin, however, displayed murine pathogenicity indistinguishable from that of the 1918 virus. Here, isogenic chimeric avian influenza viruses were constructed on an avian influenza virus backbone, differing only by hemagglutinin subtype expressed. Viruses expressing the avian H1, H6, H7, H10, and H15 subtypes were pathogenic in mice and cytopathic in normal human bronchial epithelial cells, in contrast to H2-, H3-, H5-, H9-, H11-, H13-, H14-, and H16-expressing viruses. Mouse pathogenicity was associated with pulmonary macrophage and neutrophil recruitment. These data suggest that avian influenza virus hemagglutinins H1, H6, H7, H10, and H15 contain inherent mammalian virulence factors and likely share a key virulence property of the 1918 virus. Consequently, zoonotic infections with avian influenza viruses bearing one of these hemagglutinins may cause enhanced disease in mammals.

IMPORTANCE
Influenza viruses from birds can cause outbreaks in humans and may contribute to the development of pandemics. The 1918 pandemic influenza virus has an avian influenza virus-like genome, and its main surface protein, an H1 subtype hemagglutinin, was identified as a key mammalian virulence factor. In a previous study, a 1918 virus expressing an avian H1 gene was as virulent in mice as the reconstructed 1918 virus. Here, a set of avian influenza viruses was constructed, differing only by hemagglutinin subtype. Viruses with the avian H1, H6, H7, H10, and H15 subtypes caused severe disease in mice and damaged human lung cells. Consequently, infections with avian influenza viruses bearing one of these hemagglutinins may cause enhanced disease in mammals, and therefore surveillance for human infections with these subtypes may be important in controlling future outbreaks.
Exercise interventions for weight management during pregnancy and up to 1 year postpartum among normal weight, overweight and obese women: a systematic review and meta-analysis
Authors: Elliott-Sale K J , Barnett C T , Sale C 
Published: November 2014

BackgroundThe prevalence of excessive gestation weight gain, extended postpartum weight retention and pregravid obese women is increasing and is associated with numerous adverse health outcomes.ObjectiveTo review the evidence from studies employing exercise-only interventions for weight management among pregnant and postpartum women.Search strategyTen databases were searched for randomised controlled trials conducted during pregnancy or within the 12 months following childbirth and published between 1990 and 2013.Selection criteriaThere were no restrictions to the type, frequency, duration or intensity of exercise intervention. Interventions not specifically designed to target weight were excluded. The outcomes were a change in body weight (kg) or body mass index (BMI; kg/m2).Data collection and analysisAll data were continuous and were reported as weighted mean differences (WMD), with 95% CIs. Data were analysed with a fixed-effect model and heterogeneity was determined using the I2statistic.ResultsFive studies were included in this review. Exercise significantly reduced gestational weight gain (WMD=−2.22 kg, CI −3.14 to −1.3, p≤0.00001) and had no significant effect on postpartum weight loss (WMD=−1.74 kg, CI −3.59 to 0.10, p=0.06) or BMI during pregnancy (WMD=−2.8 kg/m2, CI −5.60 to 0.00, p=0.05) or postpartum (WMD=−0.54 kg/m2, CI −1.17 to 0.08, p=0.09).ConclusionsThere is currently limited evidence to suggest that exercise can be used to limit maternal gestational weight gain.
Supporting patients with uncertain recovery: the use of the AMBER care bundle in an acute hospital
Authors: Etkind Simon Noah , Karno Jennifer , Edmonds Polly M , Carey Irene , Murtagh Fliss E M 
Published: November 2014

ObjectivesPatients who are deteriorating, with uncertain recovery and with a short prognosis often have complex needs. The AMBER care bundle systematically manages these patients by promoting consistent communication and care planning. To describe how the AMBER bundle is applied in a UK hospital. To identify factors affecting the use of the AMBER bundle in patients who subsequently died. To gain preliminary data with regard to potential markers of deterioration in groups less frequently supported by AMBERMethodsRetrospective review of electronic case notes for all deaths over 11 months on five inpatient wards where AMBER was implemented.ResultsN=149. Median age 80, IQR 72–87. Admission diagnoses: cancer (25%), non-cancer (31%), multimorbidity (44%). 38% were supported by AMBER. Patients with cancer were more frequently supported by AMBER (62% vs 30% p<0.001). Illness trajectory was defined a priori as ‘predictable gradual’ (40%), ‘predictable rapid’ (22%), ‘unpredictable’ (21%) or ‘sudden death’ (17%). ‘Predictable gradual’ deterioration resulted in more frequent support by AMBER (62% vs 21%, p<0.001). Patients were supported by AMBER after median 10 days of admission (IQR 5–17 days), and died median 9 days later (IQR 3–15 days). Patients with multimorbidity or unpredictable deterioration were less frequently supported by AMBER. Potential markers of deterioration were acute kidney injury, delirium, falls and comorbidity.ConclusionsThe use of the AMBER care bundle is affected by illness trajectory and diagnosis. Future work should clarify predictors of deterioration in patients with an unpredictable course.
On the Wielandt subgroup of generalized FC-groups
Authors: Kaplan G. , Vincenzi G. 
Published: November 2014

We extend to soluble FC*-groups, the class of generalized FC-groups introduced in [de Giovanni, Russo and Vincenzi, Groups with restricted conjugacy classes, Serdica Math. J. 28(3) (2002) 241–254], the characterization of finite soluble T-groups, and some results on the Wielandt subgroup, obtained recently in [Kaplan, On finite T-groups and the Wielandt subgroup, J. Group Theory. 14 (2011) 855–863].
Genetic Disruption of Lactate/H+ Symporters (MCTs) and Their Subunit CD147/BASIGIN Sensitizes Glycolytic Tumor Cells to Phenformin
Authors: Marchiq Ibtissam , Le Floch Renaud , Roux Danièle , Simon Marie-Pierre , Pouyssegur Jacques 
Published: November 2014

Abstract
Rapidly growing glycolytic tumors require energy and intracellular pH (pHi) homeostasis through the activity of two major monocarboxylate transporters, MCT1 and the hypoxia-inducible MCT4, in intimate association with the glycoprotein CD147/BASIGIN (BSG). To further explore and validate the blockade of lactic acid export as an anticancer strategy, we disrupted, via zinc finger nucleases, MCT4 and BASIGIN genes in colon adenocarcinoma (LS174T) and glioblastoma (U87) human cell lines. First, we showed that homozygous loss of MCT4 dramatically sensitized cells to the MCT1 inhibitor AZD3965. Second, we demonstrated that knockout of BSG leads to a decrease in lactate transport activity of MCT1 and MCT4 by 10- and 6-fold, respectively. Consequently, cells accumulated an intracellular pool of lactic and pyruvic acids, magnified by the MCT1 inhibitor decreasing further pHi and glycolysis. As a result, we found that these glycolytic/MCT-deficient cells resumed growth by redirecting their metabolism toward OXPHOS. Third, we showed that in contrast with parental cells, BSG-null cells became highly sensitive to phenformin, an inhibitor of mitochondrial complex I. Phenformin addition to these MCT-disrupted cells in normoxic and hypoxic conditions induced a rapid drop in cellular ATP-inducing cell death by “metabolic catastrophe.” Finally, xenograft analysis confirmed the deleterious tumor growth effect of MCT1/MCT4 ablation, an action enhanced by phenformin treatment. Collectively, these findings highlight that inhibition of the MCT/BSG complexes alone or in combination with phenformin provides an acute anticancer strategy to target highly glycolytic tumors. This genetic approach validates the anticancer potential of the MCT1 and MCT4 inhibitors in current development. Cancer Res; 75(1); 171–80. ©2014 AACR.
Beta-Endorphin Cell Therapy for Cancer Prevention
Authors: Zhang Changqing , Murugan Sengottuvelan , Boyadjieva Nadka , Jabbar Shaima , Shrivastava Pallavi , Sarkar Dipak K. 
Published: November 2014

Abstract
β-Endorphin (BEP)–producing neuron in the hypothalamus plays a key role in bringing the stress axis to a state of homeostasis and maintaining body immune defense system. Long-term delivery of BEP to obtain beneficial effect on chemoprevention is challenging, as the peptides rapidly develop tolerance. Using rats as animal models, we show here that transplantation of BEP neurons into the hypothalamus suppressed carcinogens- and hormone-induced cancers in various tissues and prevented growth and metastasis of established tumors via activation of innate immune functions. In addition, we show that intracerebroventricular administration of nanosphere-attached dibutyryl cyclic adenosine monophosphate (dbcAMP) increased the number of BEP neurons in the hypothalamus, reduced the stress response, enhanced the innate immune function, and prevented tumor cell growth, progression, and metastasis. BEP neuronal supplementation did not produce any deleterious effects on general health but was beneficial in suppressing age-induced alterations in physical activity, metabolic, and immune functions. We conclude that the neuroimmune system has significant control over cancer growth and progression, and that activation of the neuroimmune system via BEP neuronal supplementation/induction may have therapeutic value for cancer prevention and improvement of general health. Cancer Prev Res; 8(1); 56–67. ©2014 AACR.
The Spreading of a Buoyant Plume Beneath a Landfast Ice Cover
Authors: Kasper Jeremy L. , Weingartner Thomas J. 
Published: November 2014

AbstractIdealized numerical simulations using the Regional Ocean Modeling System demonstrate the effects of an immobile landfast ice cover that is frictionally coupled to an underice buoyant plume established by river discharge. The discharge rapidly increases and decreases over a 30-day period and has a maximum of 6000 m3 s−1. This study examined the response to a landfast ice cover of 26-km width and one that encompasses the entire shelf width. The model setting mimics spring conditions on the Alaskan Beaufort Sea (ABS) shelf. In comparison with the ice-free case subject to the same discharge scenario, underice plumes are broader and deeper, and the downwave freshwater flux is substantially decreased and delayed. Multiple anticyclonic bulges form in the ice-free case, but only a single, large bulge forms when ice is present. These differences are because of the frictional coupling between the ice and plume, which results in an Ekman-like underice boundary layer, a subsurface velocity maximum, and frictional shears that enhance vertical mixing and entrainment. For a partially ice-covered shelf, the plume spreads across the ice edge to form a swift, buoyant, ice-edge jet, whose width accords with the scale of Yankovsky and Chapman for a surface-advected plume. For a fully ice-covered shelf, the buoyant water spreads 60 km offshore over a 30-day period. For a steady discharge of 6000 m3 s−1 and a completely ice-covered shelf, the plume spreads offshore at a rate of ~1.5 km day−1 and extends ~95 km offshore after 60 days.