bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of a novel two dimensional diode array the “magic plate” as a radiation detector for radiation therapy treatment
Authors: Wong J. H. D. , Fuduli I. , Carolan M. , Petasecca M. , Lerch M. L. F. , Perevertaylo V. L. , Metcalfe P. , Rosenfeld A. B. 
Published: April 2012

Purpose:Intensity modulated radiation therapy (IMRT) utilizes the technology of multileaf collimators to deliver highly modulated and complex radiation treatment. Dosimetric verification of the IMRT treatment requires the verification of the delivered dose distribution. Two dimensional ion chamber or diode arrays are gaining popularity as a dosimeter of choice due to their real time feedback compared to film dosimetry. This paper describes the characterization of a novel 2D diode array, which has been named the “magic plate” (MP). It was designed to function as a 2D transmission detector as well as a planar detector for dose distribution measurements in a solid water phantom for the dosimetric verification of IMRT treatment delivery.Methods:The prototype MP is an 11 × 11 detector array based on thin (50μm) epitaxial diode technology mounted on a 0.6 mm thick Kapton substrate using a proprietary “drop‐in” technology developed by the Centre for Medical Radiation Physics, University of Wollongong. A full characterization of the detector was performed, including radiation damage study, dose per pulse effect, percent depth dose comparison with CC13 ion chamber and build up characteristics with a parallel plane ion chamber measurements, dose linearity, energy response and angular response.Results:Postirradiated magic plate diodes showed a reproducibility of 2.1%. The MP dose per pulse response decreased at higher dose rates while at lower dose rates the MP appears to be dose rate independent. The depth dose measurement of the MP agrees with ion chamber depth dose measurements to within 0.7% while dose linearity was excellent. MP showed angular response dependency due to the anisotropy of the silicon diode with the maximum variation in angular response of 10.8% at gantry angle 180°. Angular dependence was within 3.5% for the gantry angles ± 75°. The field size dependence of the MP at isocenter agrees with ion chamber measurement to within 1.1%. In the beam perturbation study, the surface dose increased by 12.1% for a 30 × 30 cm2 field size at the source to detector distance (SDD) of 80 cm whilst the transmission for the MP was 99%.Conclusions:The radiation response of the magic plate was successfully characterized. The array of epitaxial silicon based detectors with “drop‐in” packaging showed properties suitable to be used as a simplified multipurpose and nonperturbing 2D radiation detector for radiation therapy dosimetric verification.
Noise reduction in low‐dose cone beam CT by incorporating prior volumetric image information
Authors: Ouyang Luo , Solberg Timothy , Wang Jing 
Published: April 2012

Purpose:Repeated use of cone beam CT (CBCT) in radiotherapy introduces extra imaging dose to patients. In this work, the authors propose a method to effectively reduce the imaging dose of on‐treatment CBCT by incorporating previously acquired CBCT.Methods:The Karhunen–Loève (KL) transform was used to consider the correlation among the on‐treatment low‐dose CBCT and prior CBCTs in the projection domain. Following the KL transform, the selected CBCT projection data were decomposed into uncorrelated, ordered principal components. Then, a penalized weighted least‐squares (PWLS) criterion was applied to restore each KL component using different penalty strengths, where the penalty parameter was inversely proportional to its corresponding KL eigenvalue. Following the inverse KL transform on the processed data, the FDK algorithm was used to reconstruct the on‐treatment CBCT image. The proposed algorithm was evaluated using both phantom and patient data.Results:The proposed algorithm demonstrated the ability to suppress noise while preserving edge information effectively. This new strategy outperforms the PWLS algorithm without considering prior information based on the noise‐resolution tradeoff measurement and analyze of the reconstructed small objects.Conclusions:Information extracted from previously acquired CBCT can be effectively utilized to suppress noise in on‐treatment low‐dose CBCT. The presented strategy can significantly lower the patient CBCT radiation dose.
Sharing of Prey: Coinfection of a Bacterium by a Virus and a Prokaryotic Predator
Authors: Chen Huan , Williams Henry N. 
Published: April 2012

ABSTRACT

Rarely, if ever, has a single bacterial cell been confirmed to simultaneously host two fundamentally different predators. Two such predators are viruses and the predatory prokaryotes known as
Bdellovibrio
and like organisms. Viruses or bacteriophage are particles requiring prey cells in an active metabolic state to complete their life cycle. The
Bdellovibrio
and like organisms, unlike viruses, are bacteria that can efficiently infect and grow in prey which are in stationary phase. In this study, electron microscopic examination revealed an unprecedented coinfection by the two agents of
Vibrio vulnificus
, introducing a new bacterial predation paradigm. Rather than the viruses and
Bdellovibrio
and like organisms competing for a single prey cell, both can survive in the same cell and successfully reproduce themselves. This is an especially valuable mechanism when the prey is in short supply, and the survival of the predators may be at stake.

IMPORTANCE
This article describes the coinfection of a prokaryotic prey or host cell by both a bacteriophage (phage) and the predatory bacterium of the group
Bdellovibrio
and like organisms (BALOs). Such coinfection has not been previously reported and therefore introduces a new paradigm for predation of bacteria. This finding invites new studies on the interactions of BALOs, phage, and prey in predation. Predation is an important mechanism in nature for helping to keep bacterial populations in check and also plays a major role in the cycling of nutrients through the microbial loop. How dual infection by phage and BALOs imposes on these and other functions of predation is fertile ground for future studies and serves as a keystone reference on bacterial predation and mortality.
Human Origin for Livestock-Associated Methicillin-Resistant Staphylococcus aureus
Authors: Fitzgerald J. Ross 
Published: April 2012

ABSTRACT

Methicillin-resistant
Staphylococcus aureus
(MRSA) is a major cause of human morbidity and mortality worldwide. The emergence in the last decade of a livestock-associated MRSA (LA-MRSA) clone which also has the capacity to cause zoonotic infections in humans has raised important questions regarding its origin and its potential to cause human epidemics. An important study by L. B. Price et al. [mBio 3(1):e00305-11, 2012] provides evidence for a human ancestral origin for LA-MRSA, raising concerns about agricultural practices that may have contributed to its emergence and expansion. The study highlights the potential for comparative whole-genome sequencing of closely related strains to provide valuable insights into the evolutionary history of bacterial pathogens.
Young persons' access to genitourinary medicine clinics in the UK: a cross-sectional survey: Table 1
Authors: Thomas Melonie , Dixon Kiri , Ali Amer Henry , Patel Rajul , Robinson Angela J , Yuen H M , Foley Elizabeth 
Published: April 2012

Study DesignThis service evaluation of genitourinary medicine (GUM) clinics in the UK was designed to quantify access for young people requesting to be seen and to establish whether they could be seen outside school hours.MethodsIn December 2009 postal questionnaires were sent to all lead clinicians in UK GUM clinics asking when they expected a young person would be offered an appointment and whether it could be outside school hours. Between January and March 2010 trained male and female medical students posing as 16 year olds telephoned all GUM clinics listed on the British Association for Sexual Health and HIV website with symptomatic and asymptomatic scenarios and requested an appointment after school hours.Results99% of the 152 responding clinicians estimated that an appointment would be offered within 48 h for both male and female contacts and over 90% could be seen outside school hours whether symptomatic or not. Of the 666 clinic telephone contacts, 88% were offered an appointment within two working days, and 66% were offered an after school appointment within 2 days. There was no significant difference whether the ‘patient’ was symptomatic or not (87% vs 86%, respectively, p=0.784) in being offered an appointment within two working days. There was variation between countries, with England performing significantly better; 94% were offered an appointment within 2 days versus 58%, 55% and 67% for Wales, Scotland and Northern Ireland, respectively.ConclusionThe findings would support the impact and value of process targets on service delivery.
Postmenopausal Hormone Therapy Is Associated with a Reduced Risk of Colorectal Cancer Lacking CDKN1A Expression
Authors: Lin Jennifer H. , Morikawa Teppei , Chan Andrew T. , Kuchiba Aya , Shima Kaori , Nosho Katsuhiko , Kirkner Gregory , Zhang Shumin M. , Manson JoAnn E. , Giovannucci Edward , Fuchs Charles S. , Ogino Shuji 
Published: April 2012

Abstract
Experimental studies have shown that estrogen- or progesterone-activated signaling leads to growth inhibition effects on colon cancer cells through the upregulation of several cell-cycle regulators. However, epidemiologic studies evaluating hormone therapy use and colorectal cancer risk by the status of cell-cycle regulators are lacking. In this study, we used data from the prospective Nurses' Health Study to evaluate whether the association between hormone therapy use and colorectal cancer risk differs by the molecular pathologic status of microsatellite instability (MSI) and expression of cell-cycle–related tumor biomarkers, including CDKN1A (p21, CIP1), CDKN1B (p27, KIP1), and TP53 (p53) by immunohistochemistry. Duplication Cox regression analysis was used to determine an association between hormone therapy use, cancer risk, and specific tumor biomarkers in 581 incident colon and rectal cancer cases that occurred during 26 years of follow-up among 105,520 postmenopausal women. We found a difference between hormone therapy use and colorectal cancer risk according to CDKN1A expression (Pheterogeneity = 0.01). Current hormone therapy use was associated with a reduced risk for CDKN1A-nonexpressed [multivariate relative risk (RR), 0.61; 95% confidence interval (CI), 0.46–0.82] but not for CDKN1A-expressed (RR, 1.32; 95% CI, 0.76–2.31) tumors. The lower risk for CDKN1A-nonexpressed but not for CDKN1A-expressed cancers was also present among current users of estrogen-alone therapy. We found no significant difference in the relations between hormone therapy use and cancer risk according to MSI, CDKN1B, or TP53 status. Together, our molecular pathological epidemiology findings suggest a preventive effect of hormone therapy against colorectal carcinogenesis that depends, in part, on loss of cyclin-dependent kinase inhibitor CDKN1A. Cancer Res; 72(12); 3020–8. ©2012 AACR.
Clinical Outcomes in Non–Small Cell Lung Cancers Harboring Different Exon 19 Deletions in EGFR
Authors: Chung Kuei-Pin , Wu Shang-Gin , Wu Jenn-Yu , Yang James Chih-Hsin , Yu Chong-Jen , Wei Pin-Fei , Shih Jin-Yuan , Yang Pan-Chyr 
Published: April 2012

Abstract
Purpose: Several deletions in exon 19 of epidermal growth factor receptor (EGFR) gene have been reported in non–small cell lung cancer (NSCLC). It is unknown if deletions occurring at different amino acid positions or of different sizes are associated with different clinical outcome to EGFR tyrosine kinase inhibitors (TKI).
Experimental Design: This study enrolled NSCLC patients with deletions in EGFR exon 19. Patients who had received EGFR TKIs for advanced NSCLC were further evaluated for response rate (RR), progression-free survival (PFS), and overall survival (OS).
Results: In 308 patients with deletions in EGFR exon 19, 298 had deletions encompassing the entire amino acid string from L747 through E749 (LRE deletions). EGFR TKIs were used in 204 patients with advanced NSCLC. Patients with non-LRE deletions had the least RR, compared with those with deletions from E746 or L747 (42.9%, 68.2%, and 79.6%, respectively; P = 0.022). Patients with non-LRE deletions had relatively short median PFS, though not significantly different from those with deletions from E746 or L747 (5.9, 9.8, and 10.5 months, respectively; P = 0.665). The OS was not different among patients with deletions occurring at different amino acid positions (P = 0.776). Deletions in exon 19 of different sizes were not associated with different RR, PFS, or OS.
Conclusions: Non-LRE deletions in exon 19 were associated with worse response to EGFR TKIs, compared with LRE deletions. Therefore, the expected clinical outcome under EGFR TKIs depends on not only the existence but also the types of deletions in exon 19. Clin Cancer Res; 18(12); 3470–7. ©2012 AACR.
Defining a Gene Promoter Methylation Signature in Sputum for Lung Cancer Risk Assessment
Authors: Leng Shuguang , Do Kieu , Yingling Christin M. , Picchi Maria A. , Wolf Holly J. , Kennedy Timothy C. , Feser William J. , Baron Anna E. , Franklin Wilbur A. , Brock Malcolm V. , Herman James G. , Baylin Stephen B. , Byers Tim , Stidley Christine A. , Belinsky Steven A. 
Published: April 2012

Abstract
Purpose: To evaluate the methylation state of 31 genes in sputum as biomarkers in an expanded nested, case–control study from the Colorado cohort, and to assess the replication of results from the most promising genes in an independent case–control study of asymptomatic patients with stage I lung cancer from New Mexico.
Experimental Design: Cases and controls from Colorado and New Mexico were interrogated for methylation of up to 31 genes using nested, methylation-specific PCR. Individual genes and methylation indices were used to assess the association between methylation and lung cancer with logistic regression modeling.
Results: Seventeen genes with ORs of 1.4 to 3.6 were identified and selected for replication in the New Mexico study. Overall, the direction of effects seen in New Mexico was similar to Colorado with the largest increase in case discrimination (ORs, 3.2–4.2) seen for the PAX5α, GATA5, and SULF2 genes. Receiver operating characteristic (ROC) curves generated from seven-gene panels from Colorado and New Mexico studies showed prediction accuracy of 71% and 77%, respectively. A 22-fold increase in lung cancer risk was seen for a subset of New Mexico cases with five or more genes methylated. Sequence variants associated with lung cancer did not improve the accuracy of this gene methylation panel.
Conclusions: These studies have identified and replicated a panel of methylated genes whose integration with other promising biomarkers could initially identify the highest risk smokers for computed tomographic screening for early detection of lung cancer. Clin Cancer Res; 18(12); 3387–95. ©2012 AACR.
Dendritic Cell–Activating Vaccine Adjuvants Differ in the Ability to Elicit Antitumor Immunity Due to an Adjuvant-Specific Induction of Immunosuppressive Cells
Authors: Dang Yushe , Wagner Wolfgang M. , Gad Ekram , Rastetter Lauren , Berger Carmen M. , Holt Gregory E. , Disis Mary L. 
Published: April 2012

Abstract
Purpose: We questioned whether the vaccine adjuvant combination of TLR-7 ligand agonist, imiquimod, with granulocyte macrophage colony-stimulating factor (GM-CSF) would result in enhanced dendritic cell recruitment and activation with increased antigen-specific immunity as compared with either adjuvant used alone.
Experimental Design: The adjuvant effects of GM-CSF and imiquimod were studied in ovalbumin (OVA) and MMTVneu transgenic mice using peptide-based vaccines. Type I immunity, serum cytokines, myeloid-derived suppressive cells (MDSC), and regulatory T cells (Treg) levels were examined.
Results: Both GM-CSF and imiquimod equally induced local accumulation and activation of dendritic cells. Both adjuvants effectively enhanced OVA-specific T-cell responses. We further evaluated the antitumor efficacy of adjuvant GM-CSF and imiquimod immunizing against murine insulin-like growth factor–binding protein-2 (IGFBP-2), a nonmutated oncoprotein overexpressed in the tumors of MMTVneu transgenic mice. Tumor growth was significantly inhibited in the mice receiving IGFBP-2 peptides with GM-CSF (P = 0.000), but not in imiquimod vaccine-treated groups (P = 0.141). Moreover, the addition of imiquimod to GM-CSF negated the antitumor activity of the vaccine when GM-CSF was used as the sole adjuvant. While GM-CSF stimulated significant levels of antigen-specific T-helper cell (TH)1, imiquimod induced elevated serum interleukin (IL)-10. Both MDSC and Tregs were increased in the imiquimod-treated but not GM-CSF–treated groups (P = 0.000 and 0.006, respectively). Depleting MDSC and Treg in animals immunized with imiquimod and IGFBP-2 peptides restored antitumor activity to the levels observed with vaccination using GM-CSF as the sole adjuvant.
Conclusion: Adjuvants may induce regulatory responses in the context of a self-antigen vaccine. Adjuvant triggered immunosuppression may limit vaccine efficacy and should be evaluated in preclinical models especially when contemplating combination approaches. Clin Cancer Res; 18(11); 3122–31. ©2012 AACR.
Diazoxide Maintains Human Myocyte Volume Homeostasis During Stress
Authors: Maffit Sara K. , Sellitto Angela D. , Al‐Dadah Ashraf S. , Schuessler Richard B. , Damiano Ralph J. , Lawton Jennifer S. 
Published: April 2012

Background
Exposure to hypothermic hyperkalemic cardioplegia, hyposmotic stress, or metabolic inhibition results in significant animal myocyte swelling (6% to10%) and subsequent reduced contractility (10% to 20%). Both are eliminated by the adenosine triphosphate‐sensitive potassium channel opener diazoxide (DZX). The relationship between swelling and reduced contractility suggests that the structural change may represent one mechanism of postoperative myocardial stunning. This study evaluated human myocyte volume during stress to investigate if similar phenomena exist in human myocytes.

Methods and Results

Human atrial myocytes isolated from tissue obtained during cardiac surgery were perfused with Tyrode's physiological solution (20 minutes, 37°C), test solution (20 minutes), and Tyrode's (37°C, 20 minutes). Test solutions (
n
=6 to 12 myocytes each) included Tyrode's (37°C or 9°C), Tyrode's+DZX (9°C), hyperkalemic cardioplegia (9°C)±DZX, cardioplegia+DZX+HMR 1098 (sarcolemmal adenosine triphosphate‐sensitive potassium channel inhibitor, 9°C), cardioplegia+DZX+5‐hydroxydeconoate (mitochondrial adenosine triphosphate‐sensitive potassium channel inhibitor, 9°C), mild hyposmotic solution±DZX, metabolic inhibition±DZX, and metabolic inhibition+DZX+5‐hydroxydeconoate. Myocyte volume was recorded every 5 minutes. Exposure to hypothermic hyperkalemic cardioplegia, hyposmotic stress, or metabolic inhibition resulted in significant human myocyte swelling (8%, 7%, and 6%, respectively; all
P
<0.05 vs control). In all groups, the swelling was eliminated or lessened by DZX. The addition of channel inhibitors did not significantly alter results.

Conclusions

DZX maintains human myocyte volume homeostasis during stress via an unknown mechanism. DZX may prove to be clinically useful following the elucidation of its specific mechanism of action.

(
J Am Heart Assoc
. 2012;1:jah3‐e000778 doi

:
10.1161/JAHA.112.000778
.)
Individual Patient Data Subgroup Meta-Analysis of Surgery for Spontaneous Supratentorial Intracerebral Hemorrhage
Authors: Gregson Barbara A. , Broderick Joseph P. , Auer Ludwig M. , Batjer Hunt , Chen Xian-Cheng , Juvela Seppo , Morgenstern Lewis B. , Pantazis George C. , Teernstra Onno P.M. , Wang Wen-Zhi , Zuccarello Mario , Mendelow A. David 
Published: April 2012

Background and Purpose—
By 2010 there had been 14 published trials of surgery for intracerebral hemorrhage reported in systematic reviews or to the authors, but the role and timing of operative intervention remain controversial and the practice continues to be haphazard. This study attempted to obtain individual patient data from each of the 13 studies published since 1985 to better define groups of patients that might benefit from surgery.

Methods—
Authors of identified published articles were approached by mail, e-mail, and at conferences and invited to take part in the study. Data were obtained from 8 studies (2186 cases). Individual patient data included patient's age, Glasgow Coma Score at presentation, volume and site of hematoma, presence of intraventricular hemorrhage, method of evacuation, time to randomization, and outcome.

Results—

Meta-analysis indicated that there was improved outcome with surgery if randomization was undertaken within 8 hours of ictus (
P
=0.003), or the volume of the hematoma was 20 to 50 mL (
P
=0.004), or the Glasgow Coma Score was between 9 and 12 (
P
=0.0009), or the patient was aged between 50 and 69 years (
P
=0.01). In addition, there was some evidence that more superficial hematomas with no intraventricular hemorrhage might also benefit (
P
=0.09).

Conclusions—
There is evidence that surgery is of benefit if undertaken early before the patient deteriorates. This work identifies areas for further research. Ongoing studies in subgroups of patients such as the Surgical Trial in Lobar Intracerebral Hemorrhage (STICH II) will confirm whether these interpretations can be replicated.
Carotid Artery Anatomy and Geometry as Risk Factors for Carotid Atherosclerotic Disease
Authors: Phan Thanh G. , Beare Richard J. , Jolley Damien , Das Gita , Ren Mandy , Wong Kitty , Chong Winston , Sinnott Matthew D. , Hilton James E. , Srikanth Velandai 
Published: April 2012

Background and Purpose—
Traditional vascular risk factors do not completely explain the asymmetry, racial, and sex differences in carotid artery disease. Carotid anatomy and geometry may play a role in the pathogenesis of internal carotid artery (ICA) stenosis, but their effects are unknown. We hypothesized that carotid artery anatomy and geometry would be independently associated with ICA stenosis.

Method—
This is a retrospective study of patients with CT angiography at Monash Medical Centre, 2006 to 2007. Carotid arteries were segmented using semiautomated methods to estimate measures of carotid anatomy and geometry. Measurements of carotid artery geometry were performed according to the recent article by Thomas and colleagues. ICA stenosis was dichotomized as <30% or ≥30% stenosis. Cluster logistic regression was used to examine the associations of anatomy and geometry with stenosis accounting for the paired arteries within subjects, adjusting for age, sex, and vascular risk factors.

Results—
Mean age of the sample (n=178) was 68.4 years (SD, 14 years). The following were independently associated with ICA stenosis: ICA radius at the bifurcation (OR, 0.20; 95% CI, 0.14–0.29), ICA angle (OR, 1.05 per degree increment; 95% CI, 1.04–1.07), age (OR, 1.05 per year increment; 95% CI, 1.03–1.07), male sex (OR, 1.72; 95% CI, 1.08–2.8), and ever-smoker (OR, 1.85; 95% CI, 1.15–2.96).

Conclusions—
Carotid anatomy and geometry may enhance the risk of stenosis independent of traditional vascular risk factors and may be of help in very early identification of patients at high risk of developing carotid artery atherosclerosis for aggressive intervention.