bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of a constrained paired‐view technique in iterative reconstruction for breast tomosynthesis
Authors: Wu Gang , Mainprize James G. , Yaffe Martin J. 
Published: September 2013

Purpose:The order in which the projection views are employed in the reconstruction of tomosynthesis by iterative algorithms, such as simultaneous algebraic reconstruction technique and maximum likelihood, has a strong effect on the rate of convergence, accuracy, and the edge‐blurring artifacts in the reconstructed image. The purpose of this investigation was to characterize and evaluate the effects of ordering schemes on image quality for breast tomosynthesis reconstruction and to explore a new constrained paired‐view technique that could provide reduction of reconstruction artifacts. In this work, the authors compared several different ordering schemes and characterized the image quality and the formation of out‐of‐plane artifacts. Furthermore, a new normalization method is presented. It produces more accurate reconstructions with reduced artifacts comparing to the standard method of sequential ordering.Methods:In addition to visual assessment of image quality, several indices such as the signal‐difference‐to‐noise ratio, the artifact‐spread function, and the lesion detectability (d′) were computed to quantitatively evaluate the effect of ordering scheme. The sets of breast tomosynthesis projection images were simulated for reconstruction; one set had uniform background (white noise only) and the other two contained both anatomic background and quantum noise. Clinical breast images were also studied for comparison.Results:The authors have quantified the image quality in reconstructed slices for a range of tumor sizes. The authors’ proposed method provides better performance for all of the metrics tested (contrast, d′, and the level of artifacts) both for the uniform phantom case and in the presence of anatomical structure.Conclusions:The paired projection normalization provides better performance in the image quality of the reconstructed slices, and results in a lower level of artifacts in the Z direction. This implies that even a relatively simple method like the “side‐to‐side” sequence, which pairs two symmetrical projections with equal angular distance from the central projection, would achieve better reconstructed image quality than the conventional “step‐by‐step” method, which uses sequential projections one after another.
Cancer risk estimates from radiation therapy for heterotopic ossification prophylaxis after total hip arthroplasty
Authors: Mazonakis Michalis , Berris Theoharris , Lyraraki Efrossyni , Damilakis John 
Published: September 2013

Purpose:Heterotopic ossification (HO) is a frequent complication following total hip arthroplasty. This study was conducted to calculate the radiation dose to organs‐at‐risk and estimate the probability of cancer induction from radiotherapy for HO prophylaxis.Methods:Hip irradiation for HO with a 6 MV photon beam was simulated with the aid of a Monte Carlo model. A realistic humanoid phantom representing an average adult patient was implemented in Monte Carlo environment for dosimetric calculations. The average out‐of‐field radiation dose to stomach, liver, lung, prostate, bladder, thyroid, breast, uterus, and ovary was calculated. The organ‐equivalent‐dose to colon, that was partly included within the treatment field, was also determined. Organ dose calculations were carried out using three different field sizes. The dependence of organ doses upon the block insertion into primary beam for shielding colon and prosthesis was investigated. The lifetime attributable risk for cancer development was estimated using organ, age, and gender‐specific risk coefficients.Results:For a typical target dose of 7 Gy, organ doses varied from 1.0 to 741.1 mGy by the field dimensions and organ location relative to the field edge. Blocked field irradiations resulted in a dose range of 1.4–146.3 mGy. The most probable detriment from open field treatment of male patients was colon cancer with a high risk of 564.3 × 10−5 to 837.4 × 10−5 depending upon the organ dose magnitude and the patientˈs age. The corresponding colon cancer risk for female patients was (372.2–541.0) × 10−5. The probability of bladder cancer development was more than 113.7 × 10−5 and 110.3 × 10−5 for males and females, respectively. The cancer risk range to other individual organs was reduced to (0.003–68.5) × 10−5.Conclusions:The risk for cancer induction from radiation therapy for HO prophylaxis after total hip arthroplasty varies considerably by the treatment parameters, organ site in respect to treatment volume and patientˈs gender and age. The presented risk estimates may be useful in the follow‐up studies of irradiated patients.
Escherichia coli Biofilms Have an Organized and Complex Extracellular Matrix Structure
Authors: Hung Chia , Zhou Yizhou , Pinkner Jerome S. , Dodson Karen W. , Crowley Jan R. , Heuser John , Chapman Matthew R. , Hadjifrangiskou Maria , Henderson Jeffrey P. , Hultgren Scott J. 
Published: September 2013

ABSTRACT

Bacterial biofilms are ubiquitous in nature, and their resilience is derived in part from a complex extracellular matrix that can be tailored to meet environmental demands. Although common developmental stages leading to biofilm formation have been described, how the extracellular components are organized to allow three-dimensional biofilm development is not well understood. Here we show that uropathogenic
Escherichia coli
(UPEC) strains produce a biofilm with a highly ordered and complex extracellular matrix (ECM). We used electron microscopy (EM) techniques to image floating biofilms (pellicles) formed by UPEC. EM revealed intricately constructed substructures within the ECM that encase individual, spatially segregated bacteria with a distinctive morphology. Mutational and biochemical analyses of these biofilms confirmed curli as a major matrix component and revealed important roles for cellulose, flagella, and type 1 pili in pellicle integrity and ECM infrastructure. Collectively, the findings of this study elucidated that UPEC pellicles have a highly organized ultrastructure that varies spatially across the multicellular community.

IMPORTANCE
Bacteria can form biofilms in diverse niches, including abiotic surfaces, living cells, and at the air-liquid interface of liquid media. Encasing these cellular communities is a self-produced extracellular matrix (ECM) that can be composed of proteins, polysaccharides, and nucleic acids. The ECM protects biofilm bacteria from environmental insults and also makes the dissolution of biofilms very challenging. As a result, formation of biofilms within humans (during infection) or on industrial material (such as water pipes) has detrimental and costly effects. In order to combat bacterial biofilms, a better understanding of components required for biofilm formation and the ECM is required. This study defined the ECM composition and architecture of floating pellicle biofilms formed by
Escherichia coli
.
Novel Role for the Streptococcus pneumoniae Toxin Pneumolysin in the Assembly of Biofilms
Authors: Shak Joshua R. , Ludewick Herbert P. , Howery Kristen E. , Sakai Fuminori , Yi Hong , Harvey Richard M. , Paton James C. , Klugman Keith P. , Vidal Jorge E. 
Published: September 2013

ABSTRACT

Streptococcus pneumoniae
is an important commensal and pathogen responsible for almost a million deaths annually in children under five. The formation of biofilms by
S. pneumoniae
is important in nasopharyngeal colonization, pneumonia, and otitis media. Pneumolysin (Ply) is a toxin that contributes significantly to the virulence of
S. pneumoniae
and is an important candidate as a serotype-independent vaccine target. Having previously demonstrated that a
luxS
knockout mutant was unable to form early biofilms and expressed less
ply
mRNA than the wild type, we conducted a study to investigate the role of Ply in biofilm formation. We found that Ply was expressed in early phases of biofilm development and localized to cellular aggregates as early as 4 h postinoculation.
S. pneumoniae ply
knockout mutants in D39 and TIGR4 backgrounds produced significantly less biofilm biomass than wild-type strains at early time points, both on polystyrene and on human respiratory epithelial cells, cultured under static or continuous-flow conditions. Ply’s role in biofilm formation appears to be independent of its hemolytic activity, as
S. pneumoniae
serotype 1 strains, which produce a nonhemolytic variant of Ply, were still able to form biofilms. Transmission electron microscopy of biofilms grown on A549 lung cells using immunogold demonstrated that Ply was located both on the surfaces of pneumococcal cells and in the extracellular biofilm matrix. Altogether, our studies demonstrate a novel role for pneumolysin in the assembly of
S. pneumoniae
biofilms that is likely important during both carriage and disease and therefore significant for pneumolysin-targeting vaccines under development.

IMPORTANCE
The bacterium
Streptococcus pneumoniae
(commonly known as the pneumococcus) is commonly carried in the human nasopharynx and can spread to other body sites to cause disease. In the nasopharynx, middle ear, and lungs, the pneumococcus forms multicellular surface-associated structures called biofilms. Pneumolysin is an important toxin produced by almost all
S. pneumoniae
strains, extensively studied for its ability to cause damage to human tissue. In this paper, we demonstrate that pneumolysin has a previously unrecognized role in biofilm formation by showing that strains without pneumolysin are unable to form the same amount of biofilm on plastic and human cell substrates. Furthermore, we show that the role of pneumolysin in biofilm formation is separate from the hemolytic activity responsible for tissue damage during pneumococcal diseases. This novel role for pneumolysin suggests that pneumococcal vaccines directed against this protein should be investigated for their potential impact on biofilms formed during carriage and disease.
Hepatic hydrothorax in the absence of ascites
Authors: Sukcharoen Kittiya , Dixon Steven , Mangat Kamarjit , Stanton Andrew 
Published: September 2013

A previously well 66-year-old woman presented with a recurrent transudative right-sided pleural effusion. A nodular liver with coarse echotexture was demonstrated on ultrasound and subsequent MRI found hepatocellular carcinoma. In the absence of cardiopulmonary disease and significant protein uria, the recurrent pleural effusion was presumed to be hepatic hydrothorax despite the absence of ascites or other clinical features of chronic liver disease. The patient is currently awaiting liver transplantation.
Randomised controlled trial comparing hypnotherapy versus gabapentin for the treatment of hot flashes in breast cancer survivors: a pilot study
Authors: MacLaughlan David Shannon , Salzillo Sandra , Bowe Patrick , Scuncio Sandra , Malit Bridget , Raker Christina , Gass Jennifer S , Granai C O , Dizon Don S 
Published: September 2013

ObjectivesTo compare the efficacy of hypnotherapy versus gabapentin for the treatment of hot flashes in breast cancer survivors, and to evaluate the feasibility of conducting a clinical trial comparing a drug with a complementary or alternative method (CAM).DesignProspective randomised trial.SettingBreast health centre of a tertiary care centre.Participants15 women with a personal history of breast cancer or an increased risk of breast cancer who reported at least one daily hot flash.InterventionsGabapentin 900 mg daily in three divided doses (control) compared with standardised hypnotherapy. Participation lasted 8 weeks.Outcome measuresThe primary endpoints were the number of daily hot flashes and hot flash severity score (HFSS). The secondary endpoint was the Hot Flash Related Daily Interference Scale (HFRDIS).Results27 women were randomised and 15 (56%) were considered evaluable for the primary endpoint (n=8 gabapentin, n=7 hypnotherapy). The median number of daily hot flashes at enrolment was 4.5 in the gabapentin arm and 5 in the hypnotherapy arm. HFSS scores were 7.5 in the gabapentin arm and 10 in the hypnotherapy arm. After 8 weeks, the median number of daily hot flashes was reduced by 33.3% in the gabapentin arm and by 80% in the hypnotherapy arm. The median HFSS was reduced by 33.3% in the gabapentin arm and by 85% in the hypnotherapy arm. HFRDIS scores improved by 51.6% in the gabapentin group and by 55.2% in the hypnotherapy group. There were no statistically significant differences between groups.ConclusionsHypnotherapy and gabapentin demonstrate efficacy in improving hot flashes. A definitive trial evaluating traditional interventions against CAM methods is feasible, but not without challenges. Further studies aimed at defining evidence-based recommendations for CAM are necessary.Trial registrationclinicaltrials.gov (NCT00711529).
Validation of healthcare administrative data for the diagnosis of epilepsy
Authors: Franchi C , Giussani G , Messina P , Montesano M , Romi S , Nobili A , Fortino I , Bortolotti A , Merlino L , Beghi E ,   and the EPIRES Group
Published: September 2013

BackgroundAdministrative databases have become an important tool to monitor diseases. Patients with epilepsy could be traced using disease-specific codes and prescriptions, but formal validation is required to obtain an accurate case definition. The aim of the study was to correlate administrative data on epilepsy with an independent source of patients with epilepsy in a district of Lombardy, Northern Italy, from 2000 to 2008.MethodsData of nearly 320 600 inhabitants in the district of Lecco collected from the Drug Administrative Database of the Lombardy Region were analysed. Among them were included patients who fulfilled the International Classification of Diseases 9 (ICD-9) codes and/or the disease-specific exemption code for epilepsy and those who had at least one EEG record and took antiepileptic drugs (AEDs) as monotherapy or in variable combinations. To ascertain epilepsy cases, 11 general practitioners (GPs) with 15 728 affiliates were contacted. Multiple versions of the diagnostic algorithm were developed using different logistic regression models and all combinations of the four independent variables.ResultsAmong the GP affiliates, 71 (4.5/1000) had a gold standard diagnosis of epilepsy. The best and most conservative algorithm included EEG and selected treatment schedules and identified 61/71 patients with epilepsy (sensitivity 85.9%, CI 76.0% to 92.2%) and 15 623/15 657 patients without epilepsy (specificity 99.8%,CI 99.7% to 99.8%). The positive and negative predictive values were 64.2% and 99.9%. Sensitivity (86.7%) and the positive predictive value (68.4%) increased only slightly when patients with single seizures were included.ConclusionsA diagnostic algorithm including EEG and selected treatment schedules is only moderately sensitive for the detection of epilepsy and seizures. These findings apply only to the Northern Italian scenario.
Ambient air pollution and hypertensive disorder of pregnancy
Authors: Xu Xiaohui , Hu Hui , Ha Sandie , Roth Jeffrey 
Published: September 2013

BackgroundAmbient air pollution has been implicated in the development of hypertensive disorders of pregnancy (HDP). However, evidence of the association between air pollution and HDP is still limited, and the effects of gaseous air pollutants on HDP and their time windows of exposure have not been well studied.MethodsWe used the Florida birth registry data to investigate the associations between air pollutants (NO2, SO2, PM2.5, O3and CO) and the risks of HDP in 22 041 pregnant women in Jacksonville, Florida, USA from 2004 to 2005. Further, we examined whether air pollution exposure during different time windows defined by trimesters and the entire pregnancy had different effects on HDP.ResultsThe single-pollutant logistic regression model showed that exposure to four pollutants during the full pregnancy period was significantly associated with prevalence of HDP after adjusting for covariates: NO2(OR=1.21, 95% CI 1.09 to 1.35), PM2.5(OR=1.24, 95% CI 1.08 to 1.43), SO2(OR=1.13, 95% CI 1.01 to 1.25) and CO (OR=1.12, 95% CI 1.03 to 1.22) per IQR increase. Similar effects were observed when first trimester exposure to NO2, SO2and CO, and second trimester exposures to PM2.5were examined. Consistent results were confirmed in multiple-pollutant models.ConclusionsThis study suggests that exposure to high levels of air pollution during early pregnancy and the full gestational period was associated with increased prevalence of HDP in Florida, USA.
PP10 Green and Black Tea for the Primary Prevention of Cardiovascular Disease (CVD): A Cochrane Systematic Review
Authors: Hartley L C , Flowers N , Holmes J , Clarke A , Stranges S , Hooper L , Rees K 
Published: September 2013

BackgroundThere is increasing evidence that both green and black tea are beneficial for cardiovascular disease (CVD) prevention.ObjectiveDetermine the effects of green and black tea on the primary prevention of CVD.MethodsThe following electronic databases were searched with no language restrictions from their inception to October 2012: MEDLINE, EMBASE, CINAHL, Web of Science, the Cochrane Library and trial registers. Included studies fulfilled the following criteria: study design - RCTs, participants - free of CVD (includes those at high risk), intervention – Green tea, Black tea or tea extracts, comparator – no intervention or placebo, outcomes – diagnosis of CVD or change in the risk factor profile for CVD (blood pressure, lipids). Two reviewers independently screened titles and abstracts, assessed shortlisted studies for formal inclusion/exclusion, abstracted data and assessed methodological quality.ResultsDatabase searching resulted in1733 hits of which 130 went forward for formal inclusion/exclusion. Nine RCTs met the inclusion criteria. Five trials examined green tea extracts and four examined black tea extracts. No studies reported cardiovascular events. Black tea extracts were found to produce statistically significant reductions in LDL cholesterol (mean difference -0.46mmol/l [95% CI -0.54, -0.39]) and blood pressure (SBP - mean difference -1.85mmHG [-32.6, -0.44]; DBP - mean difference -1.32mmHG [-2.7, -0.06]), but only a small number of trials contributed to each analysis and studies were at some risk of bias. Green tea extracts were also found to produce statistically significant reductions in total cholesterol (mean difference -0.65 mmol/l [-0.81, -0.50]), LDL cholesterol (mean difference -0.58 mmol/l [-0.87, -0.28]) and blood pressure (SBP - mean difference -3.43 mmHG [-4.54, -2.31]), but only three studies contributed to each analysis. When both tea types were analysed together they showed favourable effects on LDL cholesterol (mean difference -0.47 mmol/l [-0.54, -0.40]) and blood pressure (SBP - mean difference -2.27 mmHG [-3.44, -1.11]; DBP mean difference -2.60 mmHG [-3.46, -1.73]).ConclusionThere are very few long term studies examining the intake of green or black tea for the primary prevention of CVD. The limited evidence suggests that tea has favourable effects on CVD risk factors, but due to the small number of trials contributing to each analysis the results should be treated with caution and further high quality trials with longer term follow-up are needed to confirm this.
Impact of Appropriate Use on the Prognostic Value of Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging
Authors: Doukky Rami , Hayes Kathleen , Frogge Nathan , Balakrishnan Gautam , Dontaraju Venkata Satish , Rangel Maria O. , Golzar Yasmeen , Garcia-Sayan Enrique , Hendel Robert C. 
Published: September 2013

Background—
Appropriate use criteria (AUC) have been developed to aid in the optimal use of single-photon emission computed tomography (SPECT)–myocardial perfusion imaging (MPI), a technique that is a mainstay of risk assessment for ischemic heart disease. The impact of appropriate use on the prognostic value of SPECT-MPI is unknown.

Methods and Results—

A prospective cohort study of 1511 consecutive patients undergoing outpatient, community-based SPECT-MPI was conducted. Subjects were stratified on the basis of the 2009 AUC for SPECT-MPI into an appropriate or uncertain appropriateness group and an inappropriate group. Patients were prospectively followed up for 27±10 months for major adverse cardiac events of death, death or myocardial infarction, and cardiac death or myocardial infarction. In the entire cohort, the 167 subjects (11%) with an abnormal scan experienced significantly higher rates of major adverse cardiac events and coronary revascularization than those with normal MPI. Among the 823 subjects (54.5%) whose MPIs were classified as appropriate (779, 51.6%) or uncertain (44, 2.9%), an abnormal scan predicted a multifold increase in the rates of death (9.2% versus 2.6%; hazard ratio, 3.1;
P
=0.004), death or myocardial infarction (11.8% versus 3.3%; hazard ratio, 3.3;
P
=0.001), cardiac death or myocardial infarction (6.7% versus 1.7%; hazard ratio, 3.7;
P
=0.006), and revascularization (24.7% versus 2.7%; hazard ratio, 11.4;
P
<0.001). Among the 688 subjects (45.5%) with MPI classified as inappropriate, an abnormal MPI failed to predict major adverse cardiac events, although it was associated with a high revascularization rate. Furthermore, appropriate MPI use provided incremental prognostic value beyond myocardial perfusion and ejection fraction data.

Conclusions—
When performed for appropriate indications, SPECT-MPI continues to demonstrate high prognostic value. However, inappropriate use lacks effectiveness for risk stratification, further emphasizing the need for optimal patient selection for cardiac testing.
Switching Strategy for Mechanical Thrombectomy of Acute Large Vessel Occlusion in the Anterior Circulation
Authors: Kang Dong-Hun , Kim Yong-Won , Hwang Yang-Ha , Park Jaechan , Hwang Jeong-Hyun , Kim Yong-Sun 
Published: September 2013

Background and Purpose—
We introduce the concept of a switching strategy for mechanical thrombectomy with period-to-period analysis. In period 1, forced arterial suction thrombectomy with a Penumbra reperfusion catheter was performed, even in difficult cases; in period 2, forced arterial suction thrombectomy was initially performed, with switching to Solitaire in difficult cases.

Methods—
We analyzed 135 consecutive patients treated with mechanical thrombectomy with acute large vessel occlusion in the anterior circulation, 61 from period 1 and 74 from period 2. We defined difficult case for both periods as ≥3 failed attempts at recanalization.

Results—

Period 2 showed a trend for better angiographic outcome of Thrombolysis in Cerebral Infarction 2b-3 (73.8%, period 1 versus 85.1%, period 2;
P
=0.10). In interperiod subgroup analysis of difficult cases, switching significantly outperformed nonswitching in Thrombolysis in Cerebral Infarction 2b-3 recanalization (52.7% versus 82.9%;
P
=0.030). Differences in puncture-to-recanalization time, symptomatic intracranial hemorrhage incidence, and procedure-related complications were not statistically significant.

Conclusions—
A switching strategy using 2 mechanical thrombectomy techniques (forced arterial suction thrombectomy to Solitaire) may harbor better angiographic outcomes than a 1 technique only strategy (forced arterial suction thrombectomy).