bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diminished heart rate reactivity to acute psychological stress is associated with enhanced carotid intima‐media thickness through adverse health behaviors
Authors: Ginty Annie T. , Williams Sarah E. , Jones Alexander , Roseboom Tessa J. , Phillips Anna C. , Painter Rebecca C. , Carroll Douglas , de Rooij Susanne R. 
Published: March 2016

AbstractRecent evidence demonstrates that individuals with low heart rate (HR) reactions to acute psychological stress are more likely to be obese or smokers. Smoking and obesity are established risk factors for increased carotid intima‐media thickness (IMT). The aim of this study was to examine the potential pathways linking intima‐media thickness, smoking, body mass index (BMI), and HR stress reactivity. A total of 552 participants, 47.6% male, M (SD) age = 58.3 (0.94) years, were exposed to three psychological stress tasks (Stroop, mirror drawing, and speech) preceded by a resting baseline period; HR was recorded throughout. HR reactivity was calculated as the average response across the three tasks minus average baseline HR. Smoking status, BMI, and IMT were determined by trained personnel. Controlling for important covariates (e.g., socioeconomic status), structural equation modeling revealed that BMI and smoking mediated the negative relationship between HR reactivity and IMT. The hypothesized model demonstrated a good overall fit to the data, χ2(8) = 0.692, p = .403; CFI = 1.00; TLI = 1.00 SRMR = .01; RMSEA < .001 (90% CI < 0.01–0.11). HR reactivity was negatively related to BMI (β = −.16) and smoking (β = −.18), and these in turn were positively associated with IMT (BMI: β = .10; smoking: β = .17). Diminished HR stress reactivity appears to be a marker for enlarged IMT and appears to be exerting its impact through already established risks. Future research should examine this relationship longitudinally and aim to intervene early.
Cross‐modal symbolic processing can elicit either an N2 or a protracted N2/N400 response
Authors: Griffiths Oren , Le Pelley Mike E. , Jack Bradley N. , Luque David , Whitford Thomas J. 
Published: March 2016

AbstractA cross‐modal symbolic paradigm was used to elicit EEG activity related to semantic incongruence. Twenty‐five undergraduate students viewed pairings of visual lexical cues (e.g., DOG) with congruent (50% of trials) or incongruent (50%) auditory nonlexical stimuli (animal vocalizations; e.g., sound of a dog woofing or a cat meowing). In one condition, many different pairs of congruent/incongruent stimuli were shown, whereas in a second condition only two pairs of stimuli were repeatedly shown. A typical N400‐like pattern of incongruence‐related activity (including activity in the N2 time window) was evident in the condition using many stimuli, whereas the incongruence‐related activity in the two‐stimuli condition was confined to differential N2‐like activity. A supplementary analysis excluded stimulus characteristics as the source of this differential activity between conditions. We found that a single individual performing a fixed task can demonstrate either a protracted N400‐like pattern of activity or a more temporally focused N2‐like pattern of activity in response to the same stimulus, which suggests that the N2 may be a precursor to the protracted N400 response.
Changes in the Immune System of Female Wistar Rats After Exposure to Immunosuppressive Treatment During Pregnancy
Authors: Kabat‐Koperska J. , Kolasa‐Wołosiuk A. , Wojciuk B. , Wojciechowska‐Koszko I. , Roszkowska P. , Krasnodębska‐Szponder B. , Paczkowska E. , Safranow K. , Gołembiewska E. , Machaliński B. , Ciechanowski K. 
Published: March 2016

AbstractThis experimental study assessed the impact of medications frequently used after kidney transplantation on the immune system of pregnant female Wistar rats. The study evaluates medications, both approved and contraindicated during pregnancy in common therapeutic combinations. The study was conducted on 32 female Wistar rats, subjected to immunosuppressive regimens most commonly used in therapy of human kidney transplant recipients (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; and cyclosporine A, everolimus and prednisone). The animals received drugs by oral gavage 2 weeks before pregnancy and at 3 weeks of pregnancy. We found drug regimen‐dependent differences in cytometry from spleen. Many subpopulations of lymphocytes were suppressed in rats treated with cyclosporine A, mycophenolate mofetil and prednisone and tacrolimus, mycophenolate mofetil and prednisone; the number of NK cells was increased in group of rats treated with cyclosporine A, everolimus and prednisone. We also found changes in histological examination of thymus and spleen of all treated dams. In cytokine assay, we noticed increasing levels of IL‐17 with increasing doses of concanavalin A in control group and in group of dams treated with cyclosporine A, mycophenolate mofetil and prednisone. This increase was blocked in rats treated with tacrolimus, mycophenolate mofetil and prednisone and cyclosporine A, everolimus and prednisone. Qualitative, quantitative and morphological changes of immune system in pharmacologically immunosuppressed females have been observed. Thymus structure, spleen composition and splenocytes IL‐17 production were mostly affected in drug regimen‐dependent manner.
Biomechanical Comparison of Locking Compression Plate versus Positive Profile Pins and Polymethylmethacrylate for Stabilization of the Canine Lumbar Vertebrae
Authors: Sturges Beverly K. , Kapatkin Amy S. , Garcia Tanya C. , Anwer Cona , Fukuda Shimpei , Hitchens Peta L. , Wisner Tristan , Hayashi Kei , Stover Susan M. 
Published: March 2016

ObjectiveTo compare the stiffness, angular deformation, and mode of failure of lumbar vertebral column constructs stabilized with bilateral pins and polymethylmethacrylate (Pin‐PMMA) or with a unilateral (left) locking compression plate (LCP) with monocortical screws.Study DesignEx vivo biomechanical, non‐randomized.Samples: Cadaveric canine thoracolumbar specimens (n=16).MethodsThoracolumbar (T13‐L3) vertebral specimens had the L1‐L2 vertebral motion unit stabilized with either Pin‐PMMA or LCP. Stiffness in flexion, extension, and right and left lateral bending after nondestructive testing were compared between intact (pretreated) specimens and Pin‐PMMA, and LCP constructs. The Pin‐PMMA and LCP constructs were then tested to failure in flexion and left lateral bending.ResultsBoth the Pin‐PMMA and LCP constructs had reduced range of motion at the stabilized L1‐L2 vertebral motion unit compared to intact specimens. The Pin‐PMMA constructs had less range of motion for the flexion elastic zone than LCP constructs. The Pin‐PMMA constructs were stiffer than intact specimens in flexion, extension, and lateral bending, and stiffer than LCP constructs in flexion and left lateral bending. The Pin‐PMMA constructs had less angular deformation at construct yield and lower residual deformation at L1‐L2 than LCP constructs after destructive testing to failure in flexion. The Pin‐PMMA constructs were stiffer, stronger, and had less deformation at yield than LCP constructs after destructive testing to failure in lateral bending. Most constructs failed distant to the implant and fixation site.ConclusionsPin‐PMMA constructs had greater lumbar vertebral stiffness and reduced ROM than LCP constructs; however, both Pin‐PMMA and LCP constructs were stronger than intact specimens.
Dual Bone Fixation: A Biomechanical Comparison of 3 Implant Constructs in a Mid‐Diaphyseal Fracture Model of the Feline Radius and Ulna
Authors: Preston Timothy J. , Glyde Mark , Hosgood Giselle , Day Robert E. 
Published: March 2016

ObjectiveTo compare the biomechanical properties of dual bone fixation (DBF) constructs to radial locking compression plating (LCP) in an ex vivo feline antebrachial fracture gap model.Study DesignEx vivo study.Sample PopulationCadaveric feline antebrachii (n=12 pairs).MethodsAntebrachii were radiographed to confirm normal skeletal appearance and maturity. After creation of a 5 mm radial and ulnar ostectomy, each antebrachium received 1 of 3 constructs using an incomplete randomized block design (n=8 per group). All groups received a 10 hole 2.0 mm radial LCP. DBF groups received either a 1.2 mm ulnar intramedullary pin (LCP with pin) or an 8 hole 2.0 mm ulnar LCP in addition to the radial LCP. Biomechanical testing was performed in axial compression and caudocranial and mediolateral 4‐point bending before destruction in axial compression.ResultsDBF constructs (LCP with pin and dual LCP) were significantly stiffer than radial LCP alone in axial compression and caudocranial bending. There were no differences between LCP with pin and dual LCP constructs in axial compression and caudocranial bending or between any constructs in mediolateral bending. Failure load was significantly greater for dual LCP than LCP with pin or LCP alone constructs. Failure loads were not different between LCP with pin and LCP alone.ConclusionDBF significantly increased construct stiffness and strength. Given the high complication rate reported in cat antebrachial fractures when only the radius is stabilized, surgeons should consider DBF.
Preoperative Differential Diagnosis of Canine Adrenal Tumors Using Triple‐Phase Helical Computed Tomography
Authors: Yoshida Orie , Kutara Kenji , Seki Mamiko , Ishigaki Kumiko , Teshima Kenji , Ishikawa Chieko , Iida Gentoku , Edamura Kazuya , Kagawa Yumiko , Asano Kazushi 
Published: March 2016

ObjectiveTo characterize the computed tomography (CT) findings for canine adrenal tumors, including cortical adenoma, cortical adenocarcinoma, and pheochromocytoma, and to evaluate the feasibility and usefulness of preoperative triple‐phase helical CT for differentiation of tumor types and surgical planning.Study DesignRetrospective study.AnimalsDogs with adrenal tumors (n=36).MethodsAll dogs underwent triple‐phase helical CT, followed by adrenalectomy and histopathological diagnosis of the resected mass. Precontrast images, arterial, venous, and delayed phase images were obtained. In all cases, morphological characteristics and CT values and calculations, including the percentage enhancement washout ratio, relative percentage washout, enhancement washin, and enhancement washout, were analyzed and compared among the tumor types.ResultsOf the 36 dogs with adrenal masses, cortical adenocarcinoma was most commonly diagnosed (16 dogs), followed by pheochromocytoma (13 dogs), and cortical adenoma (7 dogs). The precontrast minimum CT value and enhancement washout between venous and delayed phases in the cortical adenoma were significantly higher than those in the cortical adenocarcinoma. The maximum CT values of the precontrast image and arterial and venous phases, the enhancement washin and washouts, percentage enhancement washout ratio, and relative percentage washout in the pheochromocytomas were significantly higher than those in cortical adenocarcinoma.ConclusionThe differential diagnosis of canine adrenal tumors was feasible based on triple‐phase CT findings, including morphological features, CT values, and intratumoral contrast attenuation. Preoperative diagnosis using triple‐phase helical CT may be useful for surgical planning in dogs with adrenal tumors.
Multilevel segmentation of intracranial aneurysms in CT angiography images
Authors: Wang Yan , Zhang Yue , Navarro Laurent , Eker Omer Faruk , Corredor Jerez Ricardo A. , Chen Yu , Zhu Yuemin , Courbebaisse Guy 
Published: March 2016

Purpose:Segmentation of aneurysms plays an important role in interventional planning. Yet, the segmentation of both the lumen and the thrombus of an intracranial aneurysm in computed tomography angiography (CTA) remains a challenge. This paper proposes a multilevel segmentation methodology for efficiently segmenting intracranial aneurysms in CTA images.Methods:The proposed methodology first uses the lattice Boltzmann method (LBM) to extract the lumen part directly from the original image. Then, the LBM is applied again on an intermediate image whose lumen part is filled by the mean gray‐level value outside the lumen, to yield an image region containing part of the aneurysm boundary. After that, an expanding disk is introduced to estimate the complete contour of the aneurysm. Finally, the contour detected is used as the initial contour of the level set with ellipse to refine the aneurysm.Results:The results obtained on 11 patients from different hospitals showed that the proposed segmentation was comparable with manual segmentation, and that quantitatively, the average segmentation matching factor (SMF) reached 86.99%, demonstrating good segmentation accuracy. Chan–Vese method, Sen's model, and Luca's model were used to compare the proposed method and their average SMF values were 39.98%, 40.76%, and 77.11%, respectively.Conclusions:The authors have presented a multilevel segmentation method based on the LBM and level set with ellipse for accurate segmentation of intracranial aneurysms. Compared to three existing methods, for all eleven patients, the proposed method can successfully segment the lumen with the highest SMF values for nine patients and second highest SMF values for the two. It also segments the entire aneurysm with the highest SMF values for ten patients and second highest SMF value for the one. This makes it potential for clinical assessment of the volume and aspect ratio of the intracranial aneurysms.
Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency
Authors: Dial Christian , Weiss Elisabeth , Siebers Jeffrey V. , Hugo Geoffrey D. 
Published: March 2016

Purpose:To quantify the potential benefit associated with daily replanning in lung cancer in terms of normal tissue dose sparing and to characterize the tradeoff between adaptive benefit and replanning frequency.Methods:A set of synthetic images and contours, derived from weekly active breathing control images of 12 patients who underwent radiation therapy treatment for nonsmall cell lung cancer, is generated for each fraction of treatment using principal component analysis in a way that preserves temporal anatomical trends (e.g., tumor regression). Daily synthetic images and contours are used to simulate four different treatment scenarios: (1) a “no‐adapt” scenario that simulates delivery of an initial plan throughout treatment, (2) a “midadapt” scenario that implements a single replan for fraction 18, (3) a “weekly adapt” scenario that simulates weekly adaptations, and (4) a “full‐adapt” scenario that simulates daily replanning. An initial intensity modulated radiation therapy plan is created for each patient and replanning is carried out in an automated fashion by reoptimizing beam apertures and weights. Dose is calculated on each image and accumulated to the first in the series using deformable mappings utilized in synthetic image creation for comparison between simulated treatments.Results:Target coverage was maintained and cord tolerance was not exceeded for any of the adaptive simulations. Average reductions in mean lung dose (MLD) and volume of lung receiving 20 Gy or more (V20lung) were 65 ± 49 cGy (p = 0.000 01) and 1.1% ± 1.2% (p = 0.0006), respectively, for all patients. The largest reduction in MLD for a single patient was 162 cGy, which allowed an isotoxic escalation of the target dose of 1668 cGy. Average reductions in cord max dose, mean esophageal dose (MED), dose received by 66% of the heart (D66heart), and dose received by 33% of the heart (D33heart), were 158 ± 280, 117 ± 121, 37 ± 77, and 99 ± 120 cGy, respectively. Average incremental reductions in MLD for the midadapt, weekly adapt, and full‐adapt treatments were 38, 18, and 8 cGy, respectively. Incremental reductions in MED for the same treatments were 57, 37, and 23 cGy. Reductions in MLD and MED for the full‐adapt treatment were correlated with the absolute decrease in the planning target volume (r = 0.34 and r = 0.26).Conclusions:Adaptive radiation therapy for lung cancer yields clinically relevant reductions in normal tissue doses for frequencies of adaptation ranging from a single replan up to daily replanning. Increased frequencies of adaptation result in additional benefit while magnitude of benefit decreases.
Ultrasound intima‐media thickness measurement of the carotid artery using ant colony optimization combined with a curvelet‐based orientation‐selective filter
Authors: Li Hao , Zhang Shijie , Ma Rui , Chen Huiren , Xi Shui , Zhang Jue , Fang Jing 
Published: March 2016

Purpose:Automatic measurement of the intima‐media thickness (IMT) from ultrasound carotid images is an important task in clinical diagnosis. Many computer‐based techniques for IMT measurement have been proposed to overcome the limits of manual segmentation. However, the robustness of the algorithms would be influenced by the inherent speckle noise of ultrasound image. This paper proposed a curvelet guided ant colony optimization (CGACO) strategy that could achieve satisfied accuracy for IMT measurement with improved robustness to noise.Methods:The curvelet‐based orientation‐selective (CBOS) filter was first introduced for speckle removal and edge enhancement. Different from conventional methods, CBOS filter processes the curvelet coefficients by orientations rather than by magnitude. Then, a specially designed two‐leg ant colony optimization technique, combined with Otsu thresholding and Sobel edge detector, was proposed as a novel segmentation method to extract the media‐adventitia (MA) and the lumen‐intima (LI) boundaries. Finally, a coupled snake model was employed to further smooth the contours of MA and LI.Results:In addition to 224 carotid artery images acquired from 34 participants, simulated speckled images with nine levels of noise were also included in the database. The mean absolute distance errors of CGACO for LI interface tracings, MA interface tracings, and IMT measurements were 0.030 ± 0.027, 0.039 ± 0.036, and 0.041 ± 0.036 mm, respectively. Besides, CGACO had a correlation coefficient as high as 0.992 and a bias as low as −0.008. All these measures were comparable to or better than a previous technique and the manual segmentation. On the other hand, CGACO had the highest success rate of 98.7% in the segmentation of real data. It also maintained a much higher success rate in the segmentation of simulated images with different levels of speckle noise.Conclusions:The proposed technique showed accurate IMT measurement results. Furthermore, benefiting from the CBOS filter, the robustness to noise of the algorithm was substantially improved. Therefore, CGACO could provide a reliable way to segment the carotid artery from ultrasound images and could be used in clinical practice of IMT measurement, particularly in early atherosclerotic stages.
Discovery of the Elusive UDP-Diacylglucosamine Hydrolase in the Lipid A Biosynthetic Pathway in Chlamydia trachomatis
Authors: Young Hayley E. , Zhao Jinshi , Barker Jeffrey R. , Guan Ziqiang , Valdivia Raphael H. , Zhou Pei 
Published: March 2016

ABSTRACT

Constitutive biosynthesis of lipid A via the Raetz pathway is essential for the viability and fitness of Gram-negative bacteria, including
Chlamydia trachomatis
. Although nearly all of the enzymes in the lipid A biosynthetic pathway are highly conserved across Gram-negative bacteria, the cleavage of the pyrophosphate group of UDP-2,3-diacyl-GlcN (UDP-DAGn) to form lipid X is carried out by two unrelated enzymes: LpxH in beta- and gammaproteobacteria and LpxI in alphaproteobacteria. The intracellular pathogen
C. trachomatis
lacks an ortholog for either of these two enzymes, and yet, it synthesizes lipid A and exhibits conservation of genes encoding other lipid A enzymes. Employing a complementation screen against a
C. trachomatis
genomic library using a conditional-lethal
lpxH
mutant
Escherichia coli
strain, we have identified an open reading frame (Ct461, renamed
lpxG
) encoding a previously uncharacterized enzyme that complements the UDP-DAGn hydrolase function in
E. coli
and catalyzes the conversion of UDP-DAGn to lipid X
in vitro
. LpxG shows little sequence similarity to either LpxH or LpxI, highlighting LpxG as the founding member of a third class of UDP-DAGn hydrolases. Overexpression of LpxG results in toxic accumulation of lipid X and profoundly reduces the infectivity of
C. trachomatis
, validating LpxG as the long-sought-after UDP-DAGn pyrophosphatase in this prominent human pathogen. The complementation approach presented here overcomes the lack of suitable genetic tools for
C. trachomatis
and should be broadly applicable for the functional characterization of other essential
C. trachomatis
genes
.

IMPORTANCE
Chlamydia trachomatis
is a leading cause of infectious blindness and sexually transmitted disease. Due to the lack of robust genetic tools, the functions of many
Chlamydia
genes remain uncharacterized, including the essential gene encoding the UDP-DAGn pyrophosphatase activity for the biosynthesis of lipid A, the membrane anchor of lipooligosaccharide and the predominant lipid species of the outer leaflet of the bacterial outer membrane. We designed a complementation screen against the
C. trachomatis
genomic library using a conditional-lethal mutant of
E. coli
and identified the missing essential gene in the lipid A biosynthetic pathway, which we designated
lpxG
. We show that LpxG is a member of the calcineurin-like phosphatases and displays robust UDP-DAGn pyrophosphatase activity
in vitro
. Overexpression of LpxG in
C. trachomatis
leads to the accumulation of the predicted lipid intermediate and reduces bacterial infectivity, validating the
in vivo
function of LpxG and highlighting the importance of regulated lipid A biosynthesis in
C. trachomatis
.
Excess short-term mortality in women after isolated coronary artery bypass graft surgery
Authors: Filardo Giovanni , Hamman Baron L , Pollock Benjamin D , da Graca Briget , Sass Danielle M , Phan Teresa K , Edgerton James , Prince Syma L , Ring W Steves 
Published: March 2016

ObjectiveFemale sex is considered a risk factor for adverse outcomes following isolated coronary artery bypass graft (CABG) surgery. We assessed the association between sex and short-term mortality following isolated CABG, and estimated the ‘excess’ deaths occurring in women.MethodsShort-term mortality was investigated in 13 327 consecutive isolated CABG patients in North Texas between January 2008 and December 2012. The association between sex and CABG short-term mortality, and the excess deaths among women were assessed via a propensity-adjusted (by Society of Thoracic Surgeons-recognised risk factors) generalised estimating equations model approach.ResultsShort-term mortality was significantly higher in women than men (adjusted OR=1.39; 95% CI 1.04 to 1.86; p=0.027). This significantly greater risk translates into 35 ‘excess’ deaths among women included in this study (>10% of the total 343 deaths in the study cohort) and into 392 ‘excess’ deaths among the ∼40 000 women undergoing isolated CABG in the USA each year.ConclusionsThe higher risk associated with female sex lead to 35 ‘excess’ deaths in women in this study cohort (over 10% of the total deaths) and to 392 ‘excess’ deaths among women undergoing isolated CABG in the USA each year. Further research is needed to assess the causal mechanisms underlying this sex-related difference. Results of such work could inform the development and implementation of sex-specific treatment and management strategies to reduce women's mortality following CABG. Based on our results, if such work brought women's short-term mortality into line with men's, total short-term mortality could be reduced by up to 10%.