bluuebunny/crossref_metadata_2025_split huggingface dataset:
X‐ray scatter correction method for dedicated breast computed tomography
Authors: Sechopoulos Ioannis 
Published: May 2012

Purpose:To improve image quality and accuracy in dedicated breast computed tomography (BCT) by removing the x‐ray scatter signal included in the BCT projections.Methods:The previously characterized magnitude and distribution of x‐ray scatter in BCT results in both cupping artifacts and reduction of contrast and accuracy in the reconstructions. In this study, an image processing method is proposed that estimates and subtracts the low‐frequency x‐ray scatter signal included in each BCT projection postacquisition and prereconstruction. The estimation of this signal is performed using simple additional hardware, one additional BCT projection acquisition with negligible radiation dose, and simple image processing software algorithms. The high frequency quantum noise due to the scatter signal is reduced using a noise filter postreconstruction. The dosimetric consequences and validity of the assumptions of this algorithm were determined using Monte Carlo simulations. The feasibility of this method was determined by imaging a breast phantom on a BCT clinical prototype and comparing the corrected reconstructions to the unprocessed reconstructions and to reconstructions obtained from fan‐beam acquisitions as a reference standard. One‐dimensional profiles of the reconstructions and objective image quality metrics were used to determine the impact of the algorithm.Results:The proposed additional acquisition results in negligible additional radiation dose to the imaged breast (∼0.4% of the standard BCT acquisition). The processed phantom reconstruction showed substantially reduced cupping artifacts, increased contrast between adipose and glandular tissue equivalents, higher voxel value accuracy, and no discernible blurring of high frequency features.Conclusions:The proposed scatter correction method for dedicated breast CT is feasible and can result in highly improved image quality. Further optimization and testing, especially with patient images, is necessary to characterize its impact on clinical performance.
MORC Family ATPases Required for Heterochromatin Condensation and Gene Silencing
Authors: Moissiard Guillaume , Cokus Shawn J. , Cary Joshua , Feng Suhua , Billi Allison C. , Stroud Hume , Husmann Dylan , Zhan Ye , Lajoie Bryan R. , McCord Rachel Patton , Hale Christopher J. , Feng Wei , Michaels Scott D. , Frand Alison R. , Pellegrini Matteo , Dekker Job , Kim John K. , Jacobsen Steven E. 
Published: May 2012

To Silence or Not to SilenceRepressed genes commonly have methylated DNA, and/or covalent histone modifications associated with silent chromatin, and/or associated small interfering (si)RNAs. All three features are components of gene-silencing systems (see the Perspective byJacob and Martienssen). In a screen for components of DNA methylation gene-silencing systems in the flowering plant,Moissiardet al.(p.1448, published online 3 May) identified the genesAtMoRC1andAtMORC6, which are homologs of the mouseMicrorchidia1gene. AtMORC1 and AtMORC6 are involved in silencing transposable elements and genes corresponding to DNA-methylated loci, and yet neither gene is required for maintenance of DNA methylation. Instead,AtMoRC1andAtMORC6are related to proteins that remodel chromatin superstructure, and they seem to control gene-silencing through the higher-order compaction of methylated and silent chromatin.Qianet al.(p.1445) identified anArabidopsisgene, IDM1 (increased DNA methylation 1), that is involved in regulating DNA methylation at loci enriched for repeats and multigene families containing highly homologous genes. IDM1 protects target genes from DNA silencing and recognizes both histone H3 and methylated DNA at target loci and is able to acetylate histone H3.
Double-blind, randomised clinical assay to evaluate the efficacy of probiotics in preterm newborns weighing less than 1500 g in the prevention of necrotising enterocolitis
Authors: Fernández-Carrocera Luis Alberto , Solis-Herrera Aide , Cabanillas-Ayón Marisol , Gallardo-Sarmiento Rocío Beatriz , García-Pérez Carmina Sarisol , Montaño-Rodríguez Rosalba , Echániz-Aviles Maria Olga Leticia 
Published: May 2012

BackgroundA randomised, double-blind clinical trial was undertaken in order to assess the effectiveness of probiotics in the prevention of necrotising enterocolitis (NEC) in newborns weighing <1500 g.MethodsWe studied a group of 150 patients who were randomised in two groups after parental consent was obtained, to receive either a daily feeding supplementation with a multispecies probiotic (Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus plantarum, Bifidobacteruim infantis, Streptococcus thermophillus) 1 g per day plus their regular feedings or to receive their regular feedings with nothing added (control group), over the period of January 2007 through June 2010. Clinicians in care of the infants were blinded to the group assignment.ResultsThe primary outcome was the development of NEC. Both groups were comparable, with no differences during hospitalisation, including the type of nutrition received. Blood cultures obtained from cases that developed sepsis did not reveal lactobacillus or Bifidobacteria growth. No differences were detected in terms of NEC risk reduction (RR: 0.54, 95% CI 0.21 to 1.39) although we did observe a clear trend in the reduction of NEC frequency in the studied cases: 6 (8%) versus 12 (16%) in the control group. When the combined risk of NEC or death was calculated as a post hoc analysis, we found a significantly lower risk (RR: 0.39, 95% CI 0.17 to 0.87) for the study group.ConclusionsProbiotics may offer potential benefits for premature infants and are a promising strategy in the reduction of the risk of NEC in preterm newborns.
Older veterans and emergency department discharge information
Authors: Hastings Susan , Stechuchak Karen , Oddone Eugene , Weinberger Morris , Tucker Dana , Knaack William , Schmader Kenneth 
Published: May 2012

BackgroundStudy goals were to assess older veterans' understanding of their emergency department (ED) discharge information and to determine the association between understanding discharge information and patient assessment of overall quality of care.MethodsTelephone interviews were conducted with 305 patients aged 65 or older (or their proxies) within 48 h of discharge from a Veterans Affairs Medical Center ED. Patients were asked about their perceived understanding (at the time of ED discharge) of information about their ED diagnosis, expected course of illness, contingency plan (ie, return precautions, who to call if it got worse, potential medication side effects) and follow-up care. Overall quality of ED care was rated on a four-point scale of poor, fair, good or excellent.ResultsPatients or their proxies reported not understanding information about their ED diagnosis (21%), expected course of illness (50%), contingency plan (43%), and how soon they needed to follow-up with their primary care provider (25%). In models adjusted for age and race, a positive association was observed between perceived understanding of the cause of the problem (OR 2.3; 95% CI 1.3 to 4.0), expected duration of symptoms (OR 1.6; 95% CI 1.0 to 2.5) and the contingency plan (OR 2.2; CI 1.3 to 3.4), and rating overall ED care as excellent.ConclusionsOlder veterans may not understand key items of information at the time ED discharge, and this may have an impact on how they view the quality of ED care. Strategies are needed to improve communication of ED discharge information to older veterans and their families.
Mortality and morbidity meetings: an untapped resource for improving the governance of patient safety?
Authors: Higginson Juliet , Walters Rhiannon , Fulop Naomi 
Published: May 2012

IntroductionNational Health Service hospitals and government agencies are increasingly using mortality rates to monitor the quality of inpatient care. Mortality and Morbidity (M&M) meetings, established to review deaths as part of professional learning, have the potential to provide hospital boards with the assurance that patients are not dying as a consequence of unsafe clinical practices. This paper examines whether and how these meetings can contribute to the governance of patient safety.MethodsTo understand the arrangement and role of M&M meetings in an English hospital, non-participant observations of meetings (n=9) and semistructured interviews with meeting chairs (n=19) were carried out. Following this, a structured mortality review process was codesigned and introduced into three clinical specialties over 12 months. A qualitative approach of observations (n=30) and interviews (n=40) was used to examine the impact on meetings and on frontline clinicians, managers and board members.FindingsThe initial study of M&M meetings showed a considerable variation in the way deaths were reviewed and a lack of integration of these meetings into the hospital's governance framework. The introduction of the standardised mortality review process strengthened these processes. Clinicians supported its inclusion into M&M meetings and managers and board members saw that a standardised trust-wide process offered greater levels of assurance.ConclusionM&M meetings already exist in many healthcare organisations and provide a governance resource that is underutilised. They can improve accountability of mortality data and support quality improvement without compromising professional learning, especially when facilitated by a standardised mortality review process.
Scoring the percentage of Ki67 positive nuclei is superior to mitotic count and the mitosis marker phosphohistone H3 (PHH3) in terms of differentiating flat lesions of the bladder mucosa
Authors: Gunia Sven , Kakies Christoph , Erbersdobler Andreas , Koch Stefan , May Matthias 
Published: May 2012

AimsTo systematically compare different approaches for evaluating mucosal proliferative activity regarding their diagnostic role for delineating flat lesions of the bladder mucosa.Methods32 carcinoma in situ (CIS) and 31 flat non-CIS conditions (low-grade dysplasia and reactive atypia) of the bladder mucosa were assessed by two independent pathologists in two rounds in terms of their proliferative activity assessed by the mitotic counts on H&E-stained sections (mitoses per mm2) and immunohistochemically using the MIB-1 antibody and the mitosis marker phosphohistone H3 (PHH3). Two different approaches for immunoscoring (percentage of stained nuclei vs dichotomised height of mucosal staining considering lower half vs full-thickness marker expression) were applied. κ statistics were used to evaluate interobserver and intraobserver reproducibility.ResultsScoring the percentage of Ki67 expressing cell nuclei seems to be superior to dichotomisation of the height of mucosal staining as well as to PHH3 immunostaining and conventional mitotic counts in terms of delineating CIS from flat non-CIS conditions. This approach shows substantial (κ=0.62–0.65; p<0.001) interobserver and substantial to almost perfect (κ=0.67–0.83; p<0.001) intraobserver reproducibility.ConclusionsThe MIB-1 antibody is a useful adjunct in the differential diagnosis of conventionally challenging flat lesions of the bladder mucosa. In particular, 16% or more Ki67 positive cell nuclei favours CIS over flat non-CIS conditions, whereas 15% or less Ki67 positive cell nuclei is supportive of non-CIS conditions. However, due to some important limitations of MIB-1 staining, the MIB-1 antibody should be used as a component of a panel.
Absence of extramural venous invasion is an excellent predictor of metastasis-free survival in colorectal carcinoma stage II—a study using tangential tissue sectioning
Authors: Dirschmid Klaus , Sterlacci William , Oellig Frank , Edlinger Michael , Jasarevic Zerina , Rhomberg Michaela , Dirschmid Harald , Offner Felix 
Published: May 2012

AimsExtramural venous invasion (EVI) is an important predictor of haematogenous metastasis in colorectal cancer (CRC). However, remarkable discrepancies in incidence rates indicate major problems regarding EVI assessment. The present prospective study applies tangential vessel preparation to CRC resection specimens and correlates results of EVI with metachronous haematogenous metastatic (MHM) spread.MethodsStage II CRC diagnosed at the Institute of Pathology, University Teaching Hospital Feldkirch, Austria over a period of 30 months were analysed and tangential sectioning of the pericolonic tissue was performed. Confirmation, or exclusion of MHM, as assessed by computerised tomography, sonography or biopsy, was recorded.ResultsIn 50/79 (63%) cases EVI was detected. In 13/50 (26%), MHM developed. Of the 29/79 (37%) patients without EVI, only one (3.5%) developed MHM. Statistically, the rate of MHM for patients with EVI was independent of adjuvant chemotherapy.ConclusionsTangential sectioning of the tumour periphery in CRC stage II yields a high rate of histologically evaluable extramural veins and permits proper assessment of EVI. Absence of EVI is significantly associated with metastasis-free survival, a finding of potential therapeutic value. On the other hand, one-third of the patients with EVI and circumferential tumour growth develop MHM, a setting in which the option for adjuvant chemotherapy should be considered. This study emphasises the importance of tangential sectioning of the invasive tumour front in CRC compared with the recommended perpendicular technique. The sensitivity and specificity of this method regarding MHM are characterised.
Coexistence of Gilbert syndrome with hereditary haemolytic anaemias
Authors: Rawa Katarzyna , Adamowicz-Salach Anna , Matysiak Michał , Trzemecka Anna , Burzynska Beata 
Published: May 2012

BackgroundGilbert syndrome is an inherited disease characterised by mild unconjugated hyperbilirubinaemia caused by mutations inUGT1A1gene which lead to decreased activity of UDP-glucuronosyltransferase 1A1. The most frequent genetic defect is a homozygous TA dinucleotide insertion in the regulatory TATA box in theUGT1A1gene promoter.Methods and results182 Polish healthy individuals and 256 patients with different types of hereditary haemolytic anaemias were examined for the A(TA)nTAA motif. PCR was performed using sense primer labelled by 6-Fam and capillary electrophoresis was carried out in an ABI 3730 DNA analyser. The frequency of the (TA)7/(TA)7genotype in the control group was estimated at 18.13%, (TA)6/(TA)7at 45.05% and (TA)6/(TA)6at 36.26%. There was a statistically significant difference in the (TA)6/(TA)6genotype distribution between healthy individuals and patients with glucose-6-phosphate dehydrogenase deficiency (p=0.041). Additionally, uncommon genotypes, (TA)5/(TA)6, (TA)5/(TA)7and (TA)7/(TA)8of the promoter polymorphism, were discovered.ConclusionGenotyping of theUGT1A1gene showed distinct distribution of the common A(TA)nTAA polymorphism relative to other European populations. Because of a greater risk of hyperbilirubinaemia due to hereditary haemolytic anaemia, the diagnosis of Gilbert syndrome in this group of patients is very important.
Glutamate and GABA in the medial amygdala induce selective central sympathetic/parasympathetic cardiovascular responses
Authors: Neckel Helinton , Quagliotto Edson , Casali Karina R. , Montano Nicola , Dal Lago Pedro , Rasia-Filho Alberto A. 
Published: May 2012

Glutamate and γ-aminobutyric acid (GABA) participate in central cardiovascular control, and are found in the rat posterodorsal medial amygdala (MePD), an area of the forebrain that modulates emotional/social behaviors. Here we tested whether these neurotransmitters in the MePD could change the basal activity, chemoreflex, and baroreflex cardiovascular responses in awake rats. Power spectral analysis and symbolic analysis were used to evaluate these responses. Microinjections of saline, glutamate (2 µg), or GABA (61 ng or 100 µg; n = 5–7 rats per group) did not affect basal parameters or chemoreflex responses. However, baroreflex responses showed marked changes. Glutamate increased power spectral and symbolic sympathetic indexes related to both cardiac and vascular modulations (P < 0.05). In turn, the displacement of the baroreflex half-maximal heart rate (HR) response was associated with a GABA (61 ng) mediated decrease in the upper plateau (P < 0.05). Administration of GABA (61 ng, but not 100 µg) also increased HR variability (P < 0.05), in association with parasympathetic activation. These data add novel evidence that the MePD can promote selective responses in the central regulation of the cardiovascular system, i.e., glutamate in the MePD evoked activation of a central sympathetic reflex adjustment, whereas GABA activated a central parasympathetic one.
Metabolic and genetic factors modulating subject specific LDL-C responses to plant sterol therapy1This article is an invited review for the Journal's Made In Canada section. The authors gratefully acknowledge the training that was acquired at the Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba. We would specifically like to thank Dr. Peter Jones for his mentorship and significant contribution to the research contained within this manuscript.
Authors: Rideout Todd C. , Harding Scott V. , Mackay Dylan S. 
Published: May 2012

Reducing intestinal cholesterol absorption with plant sterol consumption is a well-characterized strategy to lower LDL-C and potentially reduce cardiovascular disease risk. However, over 50 years of clinical research demonstrate that there is significant heterogeneity in the individual LDL-C lowering response to plant sterol therapy. A clear understanding of why plant sterols work effectively in some individuals but not in others will ensure optimal integration of plant sterols in future personalized nutritional lipid-lowering strategies. This review will examine the current knowledge base surrounding the metabolic and genetic determinants of LDL-C lowering in response to plant sterol consumption.
TWO ALMOST HOMOCLINIC SOLUTIONS FOR SECOND-ORDER PERTURBED HAMILTONIAN SYSTEMS
Authors: JANCZEWSKA JOANNA 
Published: May 2012

We prove the existence of two almost homoclinic solutions for a class of second-order perturbed Hamiltonian systems [Formula: see text], where L : ℝ → ℝn2is a continuous matrix-valued function such that L(t) is symmetric and positive definite for each t ∈ ℝ, the smallest eigenvalue of L(t) → ∞ as |t| → ∞, W : ℝ × ℝn→ ℝ is a C1-map satisfying the Ambrosetti–Rabinowitz condition and f : ℝ → ℝnis continuous and sufficiently small in L2(ℝ, ℝn). We improve a result by Rabinowitz and Tanaka [Math. Z. 206 (1991) 473–499].
LORENTZ SPACE ESTIMATES FOR THE COULOMBIAN RENORMALIZED ENERGY
Authors: SERFATY SYLVIA , TICE IAN 
Published: May 2012

In this paper we obtain optimal estimates for the "currents" associated to point masses in the plane, in terms of the Coulombian renormalized energy of Sandier–Serfaty [From the Ginzburg–Landau model to vortex lattice problems, to appear in Comm. Math. Phys. (2012); One-dimensional log gases and the renormalized energy, in preparation]. To derive the estimates, we use a technique that we introduced in [Lorentz space estimates for the Ginzburg–Landau energy, J. Funct. Anal. 254(3) (2008) 773–825], which couples the "ball construction method" to estimates in the Lorentz space L2,∞.
Tunnel valleys: current knowledge and future perspectives
Authors: van der Vegt P. , Janszen A. , Moscariello A. 
Published: May 2012

Abstract
Tunnel valleys are elongated incisions that are commonly interpreted as being the result of erosional processes by subglacial meltwater occurring under continental ice sheets. The abundance, size and the primarily coarse-grained infill of these features have made tunnel valleys important hydrocarbon and groundwater reservoirs. Although numerous tunnel valleys have been described over the last century, their formation and infill remain poorly understood. This review summarizes and discusses the current knowledge of tunnel valleys, providing an overview of the observations around the world. Morphological aspects that separate tunnel valleys from other landforms are discussed, as well as the wide variety of sedimentary environments found to contribute to the infilling of these features. The depth of the incision and the character of ice retreat significantly determine the final infill architecture. The formational hypotheses proposed in the literature are assessed to test their wider applicability to all other tunnel valleys in order to find a generic model that helps in the prediction of the morphology and infilling of both Pleistocene and pre-Pleistocene age. A quasi-steady-state model, with small meltwater outbursts that erode tunnel valleys near the ice margin, seems compatible with most of the known valleys. Other proposed models require specific geographical or climatic conditions.
Gene Signatures Associated with Mouse Postnatal Hindbrain Neural Stem Cells and Medulloblastoma Cancer Stem Cells Identify Novel Molecular Mediators and Predict Human Medulloblastoma Molecular Classification
Authors: Corno Daniela , Pala Mauro , Cominelli Manuela , Cipelletti Barbara , Leto Ketty , Croci Laura , Barili Valeria , Brandalise Federico , Melzi Raffaella , Di Gregorio Alessandra , Sergi Lucia Sergi , Politi Letterio Salvatore , Piemonti Lorenzo , Bulfone Alessandro , Rossi Paola , Rossi Ferdinando , Consalez Gian Giacomo , Poliani Pietro Luigi , Galli Rossella 
Published: May 2012

Abstract
Medulloblastoma arises from mutations occurring in stem/progenitor cells located in restricted hindbrain territories. Here we report that the mouse postnatal ventricular zone lining the IV ventricle also harbors bona fide stem cells that, remarkably, share the same molecular profile with cerebellar white matter–derived neural stem cells (NSC). To identify novel molecular mediators involved in medulloblastomagenesis, we compared these distinct postnatal hindbrain-derived NSC populations, which are potentially tumor initiating, with murine compound Ptch/p53 mutant medulloblastoma cancer stem cells (CSC) that faithfully phenocopy the different variants of human medulloblastoma in vivo. Transcriptome analysis of both hindbrain NSCs and medulloblastoma CSCs resulted in the generation of well-defined gene signatures, each reminiscent of a specific human medulloblastoma molecular subclass. Most interestingly, medulloblastoma CSCs upregulated developmentally related genes, such as Ebfs, that were shown to be highly expressed in human medulloblastomas and play a pivotal role in experimental medullo-blastomagenesis. These data indicate that gene expression analysis of medulloblastoma CSCs holds great promise not only for understanding functional differences between distinct CSC populations but also for identifying meaningful signatures that might stratify medulloblastoma patients beyond histopathologic staging.
Significance: The functional and molecular comparison between the cell progenitor lineages from which medulloblastoma is thought to arise and medulloblastoma CSCs might lead to the identification of novel, potentially relevant mediators of medulloblastomagenesis. Our findings provide a rationale for the exploitation of mouse CSCs as a valuable preclinical model for human medulloblastoma, both for the definition of CSC-associated gene signatures with predictive mean and for the identification of therapeutically targetable genes. Cancer Discov; 2(6); 554–68. © 2012 AACR.
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