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Sample records for plaque mechanical analysis

  1. Mechanical model of vulnerable atherosclerotic plaque rupture

    Institute of Scientific and Technical Information of China (English)

    SU; Haijun; ZHANG; Mei; ZHANG; Yun

    2004-01-01

    Rupture of atherosclerotic plaque is the main trigger of acute cardiovascular events, but the mechanism of plaque rupture is still unknown. We have constructed a model describing the motion of the fibrous cap of the plaque using the theory of elastic mechanics and studied the stability of the plaque theoretically. It has shown that plaque rupture is the result of a dynamic interplay between factors intrinsic to the plaque itself and extrinsic factors. We have proposed a new mechanism of plaque rupture, given a new explanation about the nonlinear dynamic progress of atherosclerosis and suggested a method to identify the vulnerable plaques to manage atherosclerosis.

  2. Local axial compressive mechanical properties of human carotid atherosclerotic plaques-characterisation by indentation test and inverse finite element analysis.

    Science.gov (United States)

    Chai, Chen-Ket; Akyildiz, Ali C; Speelman, Lambert; Gijsen, Frank J H; Oomens, Cees W J; van Sambeek, Marc R H M; van der Lugt, Aad; Baaijens, Frank P T

    2013-06-21

    The fibrous cap of an atherosclerotic plaque may be prone to rupture if the occurring stresses exceed the strength of the cap. Rupture can cause acute thrombosis and subsequent ischaemic stroke or myocardial infarction. A reliable prediction of the rupture probability is essential for the appropriate treatment of atherosclerosis. Biomechanical models, which compute stresses and strain, are promising to provide a more reliable rupture risk prediction. However, these models require knowledge of the local biomechanical properties of atherosclerotic plaque tissue. For this purpose, we examined human carotid plaques using indentation experiments. The test set-up was mounted on an inverted confocal microscope to visualise the collagen fibre structure during the tests. By using an inverse finite element (FE) approach, and assuming isotropic neo-Hookean behaviour, the corresponding Young's moduli were found in the range from 6 to 891kPa (median 30kPa). The results correspond to the values obtained by other research groups who analysed the compressive Young's modulus of atherosclerotic plaques. Collagen rich locations showed to be stiffer than collagen poor locations. No significant differences were found between the Young's moduli of structured and unstructured collagen architectures as specified from confocal collagen data. Insignificant differences between the middle of the fibrous cap, the shoulder regions, and remaining plaque tissue locations indicate that axial, compressive mechanical properties of atherosclerotic plaques are independent of location within the plaque. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Mechanical Stresses in Carotid Plaques

    DEFF Research Database (Denmark)

    Samuel, Samuel Alberg

    Aterosklerose er den hyppigste årsag til død og svær invaliditet i verden. Sygdommen danner aterosklerotiske plaques, som består af lipidkerner dækket af en fibrøs kappe. Såfremt kappen brister, dannes overliggende tromber, som kan føres med blodstrømmen og forårsage strokes hvis kappen brister i...... mekaniske kræfter, som påvirker den fibrøse kappe, for at være en medvirkende årsag til plaqueruptur. Endvidere er stress-niveauerne i den fibrøse kappe en risikomarkør, som påvirkes af såvel den fibrøse kappetykkelse som lipid kerne størrelsen, blodtryk og graden af forsnævring. Imidlertid har hidtidige...... for at få fjernet deres plaques (carotis endarterektomi). Dernæst blev skanningerne segmenteret i lipid-kerne, fibrøs kappe, blodbane, karvæg og calcificationer. Endvidere blev blodets hastighed, blodtryk og karvægs deformationer målt. Disse data blev benyttet til longitudinelle fluid-struktur interaktions...

  4. Fatigue crack propagation analysis of plaque rupture.

    Science.gov (United States)

    Pei, Xuan; Wu, Baijian; Li, Zhi-Yong

    2013-10-01

    Rupture of atheromatous plaque is the major cause of stroke or heart attack. Considering that the cardiovascular system is a classic fatigue environment, plaque rupture was treated as a chronic fatigue crack growth process in this study. Fracture mechanics theory was introduced to describe the stress status at the crack tip and Paris' law was used to calculate the crack growth rate. The effect of anatomical variation of an idealized plaque cross-section model was investigated. The crack initiation was considered to be either at the maximum circumferential stress location or at any other possible locations around the lumen. Although the crack automatically initialized at the maximum circumferential stress location usually propagated faster than others, it was not necessarily the most critical location where the fatigue life reached its minimum. We found that the fatigue life was minimum for cracks initialized in the following three regions: the midcap zone, the shoulder zone, and the backside zone. The anatomical variation has a significant influence on the fatigue life. Either a decrease in cap thickness or an increase in lipid pool size resulted in a significant decrease in fatigue life. Comparing to the previously used stress analysis, this fatigue model provides some possible explanations of plaque rupture at a low stress level in a pulsatile cardiovascular environment, and the method proposed here may be useful for further investigation of the mechanism of plaque rupture based on in vivo patient data.

  5. Mechanical Interaction of an Expanding Coiled Stent with a Plaque-Containing Arterial Wall: A Finite Element Analysis.

    Science.gov (United States)

    Welch, Tré R; Eberhart, Robert C; Banerjee, Subhash; Chuong, Cheng-Jen

    2016-03-01

    Wall injury is observed during stent expansion within atherosclerotic arteries, related in part to stimulation of the inflammatory process. Wall stress and strain induced by stent expansion can be closely examined by finite element analysis (FEA), thus shedding light on procedure-induced sources of inflammation. The purpose of this work was to use FEA to examine the interaction of a coiled polymer stent with a plaque-containing arterial wall during stent expansion. An asymmetric fibrotic plaque-containing arterial wall model was created from intravascular ultrasound (IVUS) images of a diseased artery. A 3D model for a coil stent at unexpanded state was generated in SolidWorks. They were imported into ANSYS for FEA of combined stent expansion and fibrotic plaque-distortion. We simulated the stent expansion in the plaqued lumen by increasing balloon pressure from 0 to 12 atm in 1 atm step. At increasing pressure, we examined how the expanding stent exerts forces on the fibrotic plaque and vascular wall components, and how the latter collectively resist and balance the expansive forces from the stent. Results show the expanding coiled stent creates high stresses within the plaque and the surrounding fibrotic capsule. Lower stresses were observed in adjacent medial and adventitial layers. High principal strains were observed in plaque and fibrotic capsule. The results suggest fibrotic capsule rupture might occur at localized regions. The FEA/IVUS method can be adapted for routine examination of the effects of the expansion of selected furled stents against IVUS-reconstructed diseased vessels, to improve stent deployment practices.

  6. Stress analysis of fracture of atherosclerotic plaques: crack propagation modeling.

    Science.gov (United States)

    Rezvani-Sharif, Alireza; Tafazzoli-Shadpour, Mohammad; Kazemi-Saleh, Davood; Sotoudeh-Anvari, Maryam

    2016-12-09

    Traditionally, the degree of luminal obstruction has been used to assess the vulnerability of atherosclerotic plaques. However, recent studies have revealed that other factors such as plaque morphology, material properties of lesion components and blood pressure may contribute to the fracture of atherosclerotic plaques. The aim of this study was to investigate the mechanism of fracture of atherosclerotic plaques based on the mechanical stress distribution and fatigue analysis by means of numerical simulation. Realistic models of type V plaques were reconstructed based on histological images. Finite element method was used to determine mechanical stress distribution within the plaque. Assuming that crack propagation initiated at the sites of stress concentration, crack propagation due to pulsatile blood pressure was modeled. Results showed that crack propagation considerably changed the stress field within the plaque and in some cases led to initiation of secondary cracks. The lipid pool stiffness affected the location of crack formation and the rate and direction of crack propagation. Moreover, increasing the mean or pulse pressure decreased the number of cycles to rupture. It is suggested that crack propagation analysis can lead to a better recognition of factors involved in plaque rupture and more accurate determination of vulnerable plaques.

  7. A Framework for Local Mechanical Characterization of Atherosclerotic Plaques: Combination of Ultrasound Displacement Imaging and Inverse Finite Element Analysis.

    Science.gov (United States)

    Akyildiz, Ali C; Hansen, Hendrik H G; Nieuwstadt, Harm A; Speelman, Lambert; De Korte, Chris L; van der Steen, Antonius F W; Gijsen, Frank J H

    2016-04-01

    Biomechanical models have the potential to predict plaque rupture. For reliable models, correct material properties of plaque components are a prerequisite. This study presents a new technique, where high resolution ultrasound displacement imaging and inverse finite element (FE) modeling is combined, to estimate material properties of plaque components. Iliac arteries with plaques were excised from 6 atherosclerotic pigs and subjected to an inflation test with pressures ranging from 10 to 120 mmHg. The arteries were imaged with high frequency 40 MHz ultrasound. Deformation maps of the plaques were reconstructed by cross correlation of the ultrasound radiofrequency data. Subsequently, the arteries were perfusion fixed for histology and structural components were identified. The histological data were registered to the ultrasound data to construct FE model of the plaques. Material properties of the arterial wall and the intima of the atherosclerotic plaques were estimated using a grid search method. The computed displacement fields showed good agreement with the measured displacement fields, implying that the FE models were able to capture local inhomogeneities within the plaque. On average, nonlinear stiffening of both the wall and the intima was observed, and the wall of the atheroslcerotic porcine iliac arteries was markedly stiffer than the intima (877 ± 459 vs. 100 ± 68 kPa at 100 mmHg). The large spread in the data further illustrates the wide variation of the material properties. We demonstrated the feasibility of a mixed experimental-numerical framework to determine the material properties of arterial wall and intima of atherosclerotic plaques from intact arteries, and concluded that, due to the observed variation, plaque specific properties are required for accurate stress simulations.

  8. Oral biofilm models for mechanical plaque removal

    NARCIS (Netherlands)

    Verkaik, Martinus J.; Busscher, Henk J.; Rustema-Abbing, Minie; Slomp, Anje M.; Abbas, Frank; van der Mei, Henny C.

    2010-01-01

    In vitro plaque removal studies require biofilm models that resemble in vivo dental plaque. Here, we compare contact and non-contact removal of single and dual-species biofilms as well as of biofilms grown from human whole saliva in vitro using different biofilm models. Bacteria were adhered to a sa

  9. Accuracy of coronary plaque detection and assessment of interobserver agreement for plaque quantification using automatic coronary plaque analysis software on coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Laqmani, A.; Quitzke, M.; Creder, D.D.; Adam, G.; Lund, G. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology and Nuclearmedicine; Klink, T. [Wuerzburg Univ. (Germany). Inst. of Diagnostic and Interventional Radiology

    2016-10-15

    To evaluate the accuracy of automatic plaque detection and the interobserver agreement of automatic versus manually adjusted quantification of coronary plaques on coronary CT angiography (cCTA) using commercially available software. 10 cCTA datasets were evaluated using plaque software. First, the automatically detected plaques were verified. Second, two observers independently performed plaque quantification without revising the automatically constructed plaque contours (automatic approach). Then, each observer adjusted the plaque contours according to plaque delineation (adjusted approach). The interobserver agreement of both approaches was analyzed. 32 of 114 automatically identified findings were true-positive plaques, while 82 (72 %) were false-positive. 20 of 52 plaques (38 %) were missed by the software (false-negative). The automatic approach provided good interobserver agreement with relative differences of 0.9 ± 16.0 % for plaque area and -3.3 ± 33.8 % for plaque volume. Both observers independently adjusted all contours because they did not represent the plaque delineation. Interobserver agreement decreased for the adjusted approach with relative differences of 25.0 ± 24.8 % for plaque area and 20.0 ± 40.4 % for plaque volume. The automatic plaque analysis software is of limited value due to high numbers of false-positive and false-negative plaque findings. The automatic approach was reproducible but it necessitated adjustment of all constructed plaque contours resulting in deterioration of the interobserver agreement.

  10. Influence of material property variability on the mechanical behaviour of carotid atherosclerotic plaques: a 3D fluid-structure interaction analysis.

    Science.gov (United States)

    Yuan, Jianmin; Teng, Zhongzhao; Feng, Jiaxuan; Zhang, Yongxue; Brown, Adam J; Gillard, Jonathan H; Jing, Zaiping; Lu, Qingsheng

    2015-08-01

    Mechanical analysis has been shown to be complementary to luminal stenosis in assessing atherosclerotic plaque vulnerability. However, patient-specific material properties are not available and the effect of material properties variability has not been fully quantified. Media and fibrous cap (FC) strips from carotid endarterectomy samples were classified into hard, intermediate and soft according to their incremental Young's modulus. Lipid and intraplaque haemorrhage/thrombus strips were classified as hard and soft. Idealised geometry-based 3D fluid-structure interaction analyses were performed to assess the impact of material property variability in predicting maximum principal stress (Stress-P1 ) and stretch (Stretch-P1 ). When FC was thick (1000 or 600 µm), Stress-P1 at the shoulder was insensitive to changes in material stiffness, whereas Stress-P1 at mid FC changed significantly. When FC was thin (200 or 65 µm), high stress concentrations shifted from the shoulder region to mid FC, and Stress-P1 became increasingly sensitive to changes in material properties, in particular at mid FC. Regardless of FC thickness, Stretch-P1 at these locations was sensitive to changes in material properties. Variability in tissue material properties influences both the location and overall stress/stretch value. This variability needs to be accounted for when interpreting the results of mechanical modelling. © 2015 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.

  11. Effect of calcification on the mechanical stability of plaque based on a three-dimensional carotid bifurcation model

    Directory of Open Access Journals (Sweden)

    Wong Kelvin KL

    2012-02-01

    Full Text Available Abstract Background This study characterizes the distribution and components of plaque structure by presenting a three-dimensional blood-vessel modelling with the aim of determining mechanical properties due to the effect of lipid core and calcification within a plaque. Numerical simulation has been used to answer how cap thickness and calcium distribution in lipids influence the biomechanical stress on the plaque. Method Modelling atherosclerotic plaque based on structural analysis confirms the rationale for plaque mechanical examination and the feasibility of our simulation model. Meaningful validation of predictions from modelled atherosclerotic plaque model typically requires examination of bona fide atherosclerotic lesions. To analyze a more accurate plaque rupture, fluid-structure interaction is applied to three-dimensional blood-vessel carotid bifurcation modelling. A patient-specific pressure variation is applied onto the plaque to influence its vulnerability. Results Modelling of the human atherosclerotic artery with varying degrees of lipid core elasticity, fibrous cap thickness and calcification gap, which is defined as the distance between the fibrous cap and calcification agglomerate, form the basis of our rupture analysis. Finite element analysis shows that the calcification gap should be conservatively smaller than its threshold to maintain plaque stability. The results add new mechanistic insights and methodologically sound data to investigate plaque rupture mechanics. Conclusion Structural analysis using a three-dimensional calcified model represents a more realistic simulation of late-stage atherosclerotic plaque. We also demonstrate that increases of calcium content that is coupled with a decrease in lipid core volume can stabilize plaque structurally.

  12. Microbial profiling of dental plaque from mechanically ventilated patients.

    Science.gov (United States)

    Sands, Kirsty M; Twigg, Joshua A; Lewis, Michael A O; Wise, Matt P; Marchesi, Julian R; Smith, Ann; Wilson, Melanie J; Williams, David W

    2016-02-01

    Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97% gene similarity cut-off for bacterial species level identifications. A significant 'microbial shift' occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection.

  13. Directional spatial frequency analysis of lipid distribution in atherosclerotic plaque

    Science.gov (United States)

    Korn, Clyde; Reese, Eric; Shi, Lingyan; Alfano, Robert; Russell, Stewart

    2016-04-01

    Atherosclerosis is characterized by the growth of fibrous plaques due to the retention of cholesterol and lipids within the artery wall, which can lead to vessel occlusion and cardiac events. One way to evaluate arterial disease is to quantify the amount of lipid present in these plaques, since a higher disease burden is characterized by a higher concentration of lipid. Although therapeutic stimulation of reverse cholesterol transport to reduce cholesterol deposits in plaque has not produced significant results, this may be due to current image analysis methods which use averaging techniques to calculate the total amount of lipid in the plaque without regard to spatial distribution, thereby discarding information that may have significance in marking response to therapy. Here we use Directional Fourier Spatial Frequency (DFSF) analysis to generate a characteristic spatial frequency spectrum for atherosclerotic plaques from C57 Black 6 mice both treated and untreated with a cholesterol scavenging nanoparticle. We then use the Cauchy product of these spectra to classify the images with a support vector machine (SVM). Our results indicate that treated plaque can be distinguished from untreated plaque using this method, where no difference is seen using the spatial averaging method. This work has the potential to increase the effectiveness of current in-vivo methods of plaque detection that also use averaging methods, such as laser speckle imaging and Raman spectroscopy.

  14. Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial.

    Science.gov (United States)

    Liu, Ting; Maurovich-Horvat, Pál; Mayrhofer, Thomas; Puchner, Stefan B; Lu, Michael T; Ghemigian, Khristine; Kitslaar, Pieter H; Broersen, Alexander; Pursnani, Amit; Hoffmann, Udo; Ferencik, Maros

    2017-08-12

    Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm(3), 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features.

  15. IVUS-based FSI models for human coronary plaque progression study: components, correlation and predictive analysis.

    Science.gov (United States)

    Wang, Liang; Wu, Zheyang; Yang, Chun; Zheng, Jie; Bach, Richard; Muccigrosso, David; Billiar, Kristen; Maehara, Akiko; Mintz, Gary S; Tang, Dalin

    2015-01-01

    Atherosclerotic plaque progression is believed to be associated with mechanical stress conditions. Patient follow-up in vivo intravascular ultrasound coronary plaque data were acquired to construct fluid-structure interaction (FSI) models with cyclic bending to obtain flow wall shear stress (WSS), plaque wall stress (PWS) and strain (PWSn) data and investigate correlations between plaque progression measured by wall thickness increase (WTI), cap thickness increase (CTI), lipid depth increase (LDI) and risk factors including wall thickness (WT), WSS, PWS, and PWSn. Quarter average values (n = 178-1016) of morphological and mechanical factors from all slices were obtained for analysis. A predictive method was introduced to assess prediction accuracy of risk factors and identify the optimal predictor(s) for plaque progression. A combination of WT and PWS was identified as the best predictor for plaque progression measured by WTI. Plaque WT had best overall correlation with WTI (r = -0.7363, p WTI: (r = -0.3208, p < 1E-10); cap thickness: (r = 0.4541, p < 1E-10); CTI: (r = -0.1719, p = 0.0190); LD: (r = -0.2206, p < 1E-10); LDI: r = 0.1775, p < 0.0001). WSS had mixed correlation results.

  16. Evolution and rupture of vulnerable plaques: a review of mechanical effects

    Directory of Open Access Journals (Sweden)

    Assemat P

    2013-04-01

    Full Text Available Pauline Assemat, Kerry Hourigan Fluids Laboratory for Aeronautical and Industrial Research (FLAIR, Department of Mechanical and Aerospace Engineering and Division of Biological Engineering, Monash University, Melbourne, VIC, Australia Abstract: Atherosclerosis occurs as a result of the buildup and infiltration of lipid streaks in artery walls, leading to plaques. Understanding the development of atherosclerosis and plaque vulnerability is of critical importance, since plaque rupture can result in heart attack or stroke. Plaques can be divided into two distinct types: those that rupture (vulnerable and those that are less likely to rupture (stable. In the last few decades, researchers have been interested in studying the influence of the mechanical effects (blood shear stress, pressure forces, and structural stress on the plaque formation and rupture processes. In the literature, physiological experimental studies are limited by the complexity of in vivo experiments to study such effects, whereas the numerical approach often uses simplified models compared with realistic conditions, so that no general agreement of the mechanisms responsible for plaque formation has yet been reached. In addition, in a large number of cases, the presence of plaques in arteries is asymptomatic. The prediction of plaque rupture remains a complex question to elucidate, not only because of the interaction of numerous phenomena involved in this process (biological, chemical, and mechanical but also because of the large time scale on which plaques develop. The purpose of the present article is to review the current mechanical models used to describe the blood flow in arteries in the presence of plaques, as well as reviewing the literature treating the influence of mechanical effects on plaque formation, development, and rupture. Finally, some directions of research, including those being undertaken by the authors, are described. Keywords: atherosclerosis, rupture

  17. Impact of flow rates in a cardiac cycle on correlations between advanced human carotid plaque progression and mechanical flow shear stress and plaque wall stress

    Directory of Open Access Journals (Sweden)

    Ferguson Marina

    2011-07-01

    Full Text Available Abstract Background Mechanical stresses are known to play important roles in atherosclerotic plaque initiation, progression and rupture. It has been well-accepted that atherosclerosis initiation and early progression correlate negatively with flow wall shear stresses (FSS. However, mechanisms governing advanced plaque progression are not well understood. Method In vivo serial MRI data (patient follow-up were acquired from 14 patients after informed consent. Each patient had 2-4 scans (scan interval: 18 months. Thirty-two scan pairs (baseline and follow-up scans were formed with slices matched for model construction and analysis. Each scan pair had 4-10 matched slices which gave 400-1000 data points for analysis (100 points per slice on lumen. Point-wise plaque progression was defined as the wall thickness increase (WTI at each data point. 3D computational models with fluid-structure interactions were constructed based on in vivo serial MRI data to extract flow shear stress and plaque wall stress (PWS on all data points to quantify correlations between plaque progression and mechanical stresses (FSS and PWS. FSS and PWS data corresponding to both maximum and minimum flow rates in a cardiac cycle were used to investigate the impact of flow rates on those correlations. Results Using follow-up scans and maximum flow rates, 19 out of 32 scan pairs showed a significant positive correlation between WTI and FSS (positive/negative/no significance correlation ratio = 19/9/4, and 26 out of 32 scan pairs showed a significant negative correlation between WTI and PWS (correlation ratio = 2/26/4. Corresponding to minimum flow rates, the correlation ratio for WTI vs. FSS and WTI vs. PWS were (20/7/5 and (2/26/4, respectively. Using baseline scans, the correlation ratios for WTI vs. FSS were (10/12/10 and (9/13/10 for maximum and minimum flow rates, respectively. The correlation ratios for WTI vs. PWS were the same (18/5/9, corresponding to maximum and minimum

  18. Impact of flow rates in a cardiac cycle on correlations between advanced human carotid plaque progression and mechanical flow shear stress and plaque wall stress.

    Science.gov (United States)

    Yang, Chun; Canton, Gador; Yuan, Chun; Ferguson, Marina; Hatsukami, Thomas S; Tang, Dalin

    2011-07-19

    Mechanical stresses are known to play important roles in atherosclerotic plaque initiation, progression and rupture. It has been well-accepted that atherosclerosis initiation and early progression correlate negatively with flow wall shear stresses (FSS). However, mechanisms governing advanced plaque progression are not well understood. In vivo serial MRI data (patient follow-up) were acquired from 14 patients after informed consent. Each patient had 2-4 scans (scan interval: 18 months). Thirty-two scan pairs (baseline and follow-up scans) were formed with slices matched for model construction and analysis. Each scan pair had 4-10 matched slices which gave 400-1000 data points for analysis (100 points per slice on lumen). Point-wise plaque progression was defined as the wall thickness increase (WTI) at each data point. 3D computational models with fluid-structure interactions were constructed based on in vivo serial MRI data to extract flow shear stress and plaque wall stress (PWS) on all data points to quantify correlations between plaque progression and mechanical stresses (FSS and PWS). FSS and PWS data corresponding to both maximum and minimum flow rates in a cardiac cycle were used to investigate the impact of flow rates on those correlations. Using follow-up scans and maximum flow rates, 19 out of 32 scan pairs showed a significant positive correlation between WTI and FSS (positive/negative/no significance correlation ratio = 19/9/4), and 26 out of 32 scan pairs showed a significant negative correlation between WTI and PWS (correlation ratio = 2/26/4). Corresponding to minimum flow rates, the correlation ratio for WTI vs. FSS and WTI vs. PWS were (20/7/5) and (2/26/4), respectively. Using baseline scans, the correlation ratios for WTI vs. FSS were (10/12/10) and (9/13/10) for maximum and minimum flow rates, respectively. The correlation ratios for WTI vs. PWS were the same (18/5/9), corresponding to maximum and minimum flow rates. Flow shear stress

  19. Efficacy of homecare regimens for mechanical plaque removal in managing gingivitis: a meta review

    NARCIS (Netherlands)

    van der Weijden, F.A.; Slot, D.E.

    2015-01-01

    Focused question Based on evidence as presented in systematic reviews what is the efficacy and safety of available homecare toothbrush regimens for mechanical plaque removal on plaque and gingivitis in adults? Material & Methods Three Internet sources were used (up to and including August 2014) to

  20. Efficacy of homecare regimens for mechanical plaque removal in managing gingivitis: a meta review

    NARCIS (Netherlands)

    van der Weijden, F.A.; Slot, D.E.

    2015-01-01

    Focused question Based on evidence as presented in systematic reviews what is the efficacy and safety of available homecare toothbrush regimens for mechanical plaque removal on plaque and gingivitis in adults? Material & Methods Three Internet sources were used (up to and including August 2014) to s

  1. Efficacy and mechanisms of non-antibacterial, chemical plaque control by dentifrices - An in vitro study

    NARCIS (Netherlands)

    Busscher, Henk J.; White, Don J.; Atema-Smit, Jelly; van der Mei, Henny C.

    Objectives: The provision of antiplaque benefits to dentifrices assists patients in improving hygiene and reducing susceptibility to gingivitis and caries. Chemical plaque control involves different mechanisms and is mostly associated with antibacterial effects, but also includes effects on pellicle

  2. Three-dimensional reconstruction and analysis of structure characteristics on senile plaques of Alzheimer's disease

    Institute of Scientific and Technical Information of China (English)

    YE Wei; LIU Jianwu; ZHOU Jiangning; HU Xiangyou; TANG Xiaowei

    2005-01-01

    Alzheimer's disease is a progressive neuro- degenerative disorder characterized by the presence of senile plaques primarily composed of amyloid ( in brain. Abnormal secretion and aggregation of amyloid ( are the key events in pathogenesis of Alzheimer's disease. Reduction of amyloid ( production and inhibition of amyloid ( aggregation to form senile plaques are hopeful strategies for the treatment and prevention of Alzheimer's disease. In the present study, the silver and immunohistochemical staining methods were applied to discover senile plaques in the hippocampus of Alzheimer's disease patients, and then images were processed and three-dimensionally reconstructed by Matlab and AVS software. The structure characteristics of senile plaques were measured through correlation function calculation and fractal dimension by a computer-aided method. Diffuse plaque had no amyloid center, but classic plaque presented compact central core structure; two types of plaques were both of porous structure, but the sizes of their pores were significantly different. Furthermore, there was difference in fractal dimension value between the diffuse plaque and classic plaque in the two staining methods. The comparison of structure characteristics between two types of plaques indicated that they developed independently. Establishment of the methods for reconstructing the three-dimen- sional structure of senile plaque and analyzing their structure characteristics is helpful for further study on the aggregation mechanism of senile plaque.

  3. Numerical analysis of the hemodynamic effect of plaque ulceration in the stenotic carotid artery bifurcation

    Science.gov (United States)

    Wong, Emily Y.; Milner, Jaques S.; Steinman, David A.; Poepping, Tamie L.; Holdsworth, David W.

    2009-02-01

    The presence of ulceration in carotid artery plaque is an independent risk factor for thromboembolic stroke. However, the associated pathophysiological mechanisms - in particular the mechanisms related to the local hemodynamics in the carotid artery bifurcation - are not well understood. We investigated the effect of carotid plaque ulceration on the local time-varying three-dimensional flow field using computational fluid dynamics (CFD) models of a stenosed carotid bifurcation geometry, with and without the presence of ulceration. CFD analysis of each model was performed with a spatial finite element discretization of over 150,000 quadratic tetrahedral elements and a temporal discretization of 4800 timesteps per cardiac cycle, to adequately resolve the flow field and pulsatile flow, respectively. Pulsatile flow simulations were iterated for five cardiac cycles to allow for cycle-to-cycle analysis following the damping of initial transients in the solution. Comparison between models revealed differences in flow patterns induced by flow exiting from the region of the ulcer cavity, in particular, to the shape, orientation and helicity of the high velocity jet through the stenosis. The stenotic jet in both models exhibited oscillatory motion, but produced higher levels of phase-ensembled turbulence intensity in the ulcerated model. In addition, enhanced out-of-plane recirculation and helical flow was observed in the ulcerated model. These preliminary results suggest that local fluid behaviour may contribute to the thrombogenic risk associated with plaque ulcerations in the stenotic carotid artery bifurcation.

  4. Stability Analysis of a Model of Atherosclerotic Plaque Growth

    Directory of Open Access Journals (Sweden)

    Sushruth Reddy

    2015-01-01

    Full Text Available Atherosclerosis, the formation of life-threatening plaques in blood vessels, is a form of cardiovascular disease. In this paper, we analyze a simplified model of plaque growth to derive physically meaningful results about the growth of plaques. In particular, the main results of this paper are two conditions, which express that the immune response increases as LDL cholesterol levels increase and that diffusion prevails over inflammation in a healthy artery.

  5. Efficacy of inter-dental mechanical plaque control in managing gingivitis - a meta-review

    NARCIS (Netherlands)

    Sälzer, S.A.; Slot, D.E.; van der Weijden, F.A.; Dörfer, C.E.

    2015-01-01

    Focused question What is the effect of mechanical inter-dental plaque removal in addition to toothbrushing, on managing gingivitis using various formats of inter-dental self-care in adults based on evidence gathered from existing systematic reviews? Material & Methods Three Internet sources were

  6. Efficacy of inter-dental mechanical plaque control in managing gingivitis - a meta-review

    NARCIS (Netherlands)

    Sälzer, S.A.; Slot, D.E.; van der Weijden, F.A.; Dörfer, C.E.

    2015-01-01

    Focused question What is the effect of mechanical inter-dental plaque removal in addition to toothbrushing, on managing gingivitis using various formats of inter-dental self-care in adults based on evidence gathered from existing systematic reviews? Material & Methods Three Internet sources were sea

  7. Coronary plaque composition as assessed by greyscale intravascular ultrasound and radiofrequency spectral data analysis

    NARCIS (Netherlands)

    N. Gonzalo (Nieves); H.M. Garcia-Garcia (Hector); J.M.R. Ligthart (Jürgen); G.A. Rodriguez-Granillo (Gaston); E. Meliga (Emanuele); Y. Onuma (Yoshinobu); J.C.H. Schuurbiers (Johan); N. Bruining (Nico); P.W.J.C. Serruys (Patrick)

    2008-01-01

    textabstractObjectives: (i) To explore the relation between greyscale intravascular ultrasound (IVUS) plaque qualitative classification and IVUS radiofrequency data (RFD) analysis tissue types; (ii) to evaluate if plaque composition as assessed by RFD analysis can be predicted by visual assessment o

  8. Lumen irregularity dominates the relationship between mechanical stress condition, fibrous-cap thickness, and lumen curvature in carotid atherosclerotic plaque.

    Science.gov (United States)

    Teng, Zhongzhao; Sadat, Umar; Ji, Guangyu; Zhu, Chengcheng; Young, Victoria E; Graves, Martin J; Gillard, Jonathan H

    2011-03-01

    High mechanical stress condition over the fibrous cap (FC) has been widely accepted as a contributor to plaque rupture. The relationships between the stress, lumen curvature, and FC thickness have not been explored in detail. In this study, we investigate lumen irregularity-dependent relationships between mechanical stress conditions, local FC thickness (LT(FC)), and lumen curvature (LC(lumen)). Magnetic resonance imaging slices of carotid plaque from 100 patients with delineated atherosclerotic components were used. Two-dimensional structure-only finite element simulations were performed for the mechanical analysis, and maximum principal stress (stress-P₁) at all integral nodes along the lumen was obtained. LT(FC) and LC(lumen) were computed using the segmented contour. The lumen irregularity (L-δir) was defined as the difference between the largest and the smallest lumen curvature. The results indicated that the relationship between stress-P₁, LT(FC), and LC(lumen) is largely dependent on L-δir. When L-δir ≥ .31 (irregular lumen), stress-P₁ strongly correlated with lumen curvature and had a weak/no correlation with local FC thickness, and in 73.4% of magnetic resonance (MR) slices, the critical stress (maximum of stress-P₁ over the diseased region) was found at the site where the lumen curvature was large. When L-δir ≤ 0.28 (relatively round lumen), stress-P₁ showed a strong correlation with local FC thickness but weak/no correlation with lumen curvature, and in 71.7% of MR slices, the critical stress was located at the site of minimum FC thickness. Using lumen irregularity as a method of identifying vulnerable plaque sites by referring to the lumen shape is a novel and simple method, which can be used for mechanics-based plaque vulnerability assessment.

  9. Optical measurement of arterial mechanical properties: from atherosclerotic plaque initiation to rupture

    Science.gov (United States)

    Nadkarni, Seemantini K.

    2013-12-01

    During the pathogenesis of coronary atherosclerosis, from lesion initiation to rupture, arterial mechanical properties are altered by a number of cellular, molecular, and hemodynamic processes. There is growing recognition that mechanical factors may actively drive vascular cell signaling and regulate atherosclerosis disease progression. In advanced plaques, the mechanical properties of the atheroma influence stress distributions in the fibrous cap and mediate plaque rupture resulting in acute coronary events. This review paper explores current optical technologies that provide information on the mechanical properties of arterial tissue to advance our understanding of the mechanical factors involved in atherosclerosis development leading to plaque rupture. The optical approaches discussed include optical microrheology and traction force microscopy that probe the mechanical behavior of single cell and extracellular matrix components, and intravascular imaging modalities including laser speckle rheology, optical coherence elastography, and polarization-sensitive optical coherence tomography to measure the mechanical properties of advanced coronary lesions. Given the wealth of information that these techniques can provide, optical imaging modalities are poised to play an increasingly significant role in elucidating the mechanical aspects of coronary atherosclerosis in the future.

  10. Comparison of carotid plaque tissue characteristics in patients with acute coronary syndrome or stable angina pectoris: assessment by iPlaque, transcutaneous carotid ultrasonography with integrated backscatter analysis.

    Science.gov (United States)

    Bando, Mika; Yamada, Hirotsugu; Kusunose, Kenya; Fukuda, Daiju; Amano, Rie; Tamai, Rina; Torii, Yuta; Hirata, Yukina; Nishio, Susumu; Yamaguchi, Koji; Soeki, Takeshi; Wakatsuki, Tetsuzo; Sata, Masataka

    2015-07-25

    The association of the tissue characteristics of carotid plaques with coronary artery disease has attracted interest. The present study compared the tissue characteristics of carotid plaques in patients with acute coronary syndrome (ACS) with those in patients with stable angina pectoris (SAP) using the iPlaque system, which is based on ultrasound integrated backscatter. Carotid ultrasound examinations were performed in 26 patients with ACS, and 38 age- and gender-matched patients with SAP. Neither plaque area nor maximal intima-media thickness differed significantly between the two groups. However, the average integrated backscatter value within the plaque was greater in the ACS patients than in the SAP patients. iPlaque analysis revealed that the percentage blue area (lipid pool) was greater in the ACS patients than in the SAP patients (43.4 ± 11.2 vs 18.3 ± 10.3%, p < 0.0001), and that the percentage green area (fibrosis) was lower in the ACS than in the SAP patients (7.5 ± 7.5% vs 20.7 ± 11.7%, p < 0.0001). The lipid component of carotid plaques is greater in ACS patients than in SAP patients. Our iPlaque system provides a useful and feasible method for the tissue characterization of carotid plaques in the clinical setting.

  11. Correlations between carotid plaque progression and mechanical stresses change sign over time: a patient follow up study using MRI and 3D FSI models.

    Science.gov (United States)

    Tang, Dalin; Yang, Chun; Canton, Gador; Wu, Zheyang; Hatsukami, Thomas; Yuan, Chun

    2013-10-14

    Increasing evidence suggests that mechanisms governing advanced plaque progression may be different from those for early progression and require further investigation. Serial MRI data and 3D fluid-structure interaction (FSI) models were employed to identify possible correlations between mechanical stresses and advanced plaque progression measured by vessel wall thickness increase (WTI). Long-term patient follow up was used to gather data and investigate if the correlations identified above were reproducible. In vivo MRI data were acquired from 16 patients in a follow-up study with 2 to 4 scans for each patient (scan interval: average 18 months and standard deviation 6.8 months). A total of 38 scan pairs (baseline and follow-up) were formed for analysis using the carotid bifurcation as the registration point. 3D FSI models were constructed to obtain plaque wall stress (PWS) and flow shear stress (FSS) to quantify their correlations with plaque progression. The Linear Mixed-Effects models were used to study possible correlations between WTI and baseline PWS and FSS with nodal dependence taken into consideration. Of the 38 scan pairs, 22 pairs showed positive correlation between baseline PWS and WTI, 1 pair showed negative correlation, and 15 pairs showed no correlation. Thirteen patients changed their correlation sign (81.25%). Between baseline FSS and WTI, 16 pairs showed negative correlation, 1 pair showed positive correlation. Twelve patients changed correlation sign (75%). Our results showed that advanced plaque progression had an overall positive correlation with plaque wall stress and a negative correlation with flow shear stress at baseline. However, long-term follow up showed that correlations between plaque progress and mechanical stresses (FSS and PWS) identified for one time period were not re-producible for most cases (>80%). Further investigations are needed to identify the reasons causing the correlation sign changes.

  12. Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro

    NARCIS (Netherlands)

    T.P.M. Goderie; G. van Soest (Gijs); H.M. Garcia-Garcia (Hector); N. Gonzalo (Nieves); S. Koljenovic (Senada); G.J.H.L. Leenders (Geert); F. Mastik (Frits); E.S. Regar (Eveline); J.W. Oosterhuis (Wolter); P.W.J.C. Serruys (Patrick); A.F.W. van der Steen (Ton)

    2010-01-01

    textabstractThis study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods h

  13. Multi-scale AM-FM motion analysis of ultrasound videos of carotid artery plaques

    Science.gov (United States)

    Murillo, Sergio; Murray, Victor; Loizou, C. P.; Pattichis, C. S.; Pattichis, Marios; Barriga, E. Simon

    2012-03-01

    An estimated 82 million American adults have one or more type of cardiovascular diseases (CVD). CVD is the leading cause of death (1 of every 3 deaths) in the United States. When considered separately from other CVDs, stroke ranks third among all causes of death behind diseases of the heart and cancer. Stroke accounts for 1 out of every 18 deaths and is the leading cause of serious long-term disability in the United States. Motion estimation of ultrasound videos (US) of carotid artery (CA) plaques provides important information regarding plaque deformation that should be considered for distinguishing between symptomatic and asymptomatic plaques. In this paper, we present the development of verifiable methods for the estimation of plaque motion. Our methodology is tested on a set of 34 (5 symptomatic and 29 asymptomatic) ultrasound videos of carotid artery plaques. Plaque and wall motion analysis provides information about plaque instability and is used in an attempt to differentiate between symptomatic and asymptomatic cases. The final goal for motion estimation and analysis is to identify pathological conditions that can be detected from motion changes due to changes in tissue stiffness.

  14. Influence of Adaptive Statistical Iterative Reconstruction on coronary plaque analysis in coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Precht, Helle; Kitslaar, Pieter H; Broersen, Alexander

    2016-01-01

    PURPOSE: The purpose of this study was to study the effect of iterative reconstruction (IR) software on quantitative plaque measurements in coronary computed tomography angiography (CCTA). METHODS: Thirty patients with a three clinical risk factors for coronary artery disease (CAD) had one CCTA...... performed. Images were reconstructed using FBP, 30% and 60% adaptive statistical IR (ASIR). Coronary plaque analysis was performed as per patient and per vessel (LM, LAD, CX and RCA) measurements. Lumen and vessel volumes and plaque burden measurements were based on automatic detected contours in each...

  15. Effect of atherosclerosis on thermo-mechanical properties of arterial wall and its repercussion on plaque instability.

    Science.gov (United States)

    Guinea, G V; Atienza, J M; Fantidis, P; Rojo, F J; Ortega, A; Torres, M; Gonzalez, P; Elices, M L; Hayashi, K; Elices, M

    2009-03-06

    Data from the literature report febrile reactions prior to myocardial infarction in patients with normal coronary arteries and that coronary syndromes seem to be triggered by bacterial and viral infections, being fever the common symptom. The thermo-mechanical behavior of thoracic aortas of New Zealand White rabbits with different degrees of atherosclerosis was measured by means of pressure-diameter tests at different temperatures. Specific measurements of the thermal dilatation coefficient of atheroma plaques were performed by means of tensile tests. Results show a different thermo-mechanical behavior, the dilatation coefficient of atheroma plaque being at least twice that of the arterial wall. Temperature-induced mechanical stress at the plaque-vessel interface could be enough to promote plaque rupture. Therefore, increases of corporal temperature, either local or systemic, can play a role in increasing the risk of acute coronary syndromes and deserve a more comprehensive study.

  16. Antimicrobial agents used in the control of periodontal biofilms: effective adjuncts to mechanical plaque control?

    Science.gov (United States)

    Teles, Ricardo Palmier; Teles, Flavia Rocha Fonseca

    2009-01-01

    The control of biofilm accumulation on teeth has been the cornerstone of periodontal disease prevention for decades. However, the widespread prevalence of gingivitis suggests the inefficiency of self-performed mechanical plaque control in preventing gingival inflammation. This is particularly relevant in light of recent evidence suggesting that long standing gingivitis increases the risk of loss of attachment and that prevention of gingival inflammation might reduce the prevalence of mild to moderate periodontitis. Several antimicrobials have been tested as adjuncts to mechanical plaque control in order to improve the results obtained with oral home care. Recent studies, including meta-analyses, have indicated that home care products containing chemical antimicrobials can provide gingivitis reduction beyond what can be accomplished with brushing and flossing. Particularly, formulations containing chlorhexidine, mouthrinses containing essential oils and triclosan/copolymer dentifrices have well documented clinical antiplaque and antigingivitis effects. In vivo microbiological tests have demonstrated the ability of these antimicrobial agents to penetrate the biofilm mass and to kill bacteria growing within biofilms. In addition, chemical antimicrobials can reach difficult-to-clean areas such as interproximal surfaces and can also impact the growth of biofilms on soft tissue. These agents have a positive track record of safety and their use does not seem to increase the levels of resistant species. Further, no study has been able to establish a correlation between mouthrinses containing alcohol and oral cancer. In summary, the adjunct use of chemical plaque control should be recommended to subjects with well documented difficulties in achieving proper biofilm control using only mechanical means.

  17. Antimicrobial agents used in the control of periodontal biofilms: effective adjuncts to mechanical plaque control?

    Directory of Open Access Journals (Sweden)

    Ricardo Palmier Teles

    2009-06-01

    Full Text Available The control of biofilm accumulation on teeth has been the cornerstone of periodontal disease prevention for decades. However, the widespread prevalence of gingivitis suggests the inefficiency of self-performed mechanical plaque control in preventing gingival inflammation. This is particularly relevant in light of recent evidence suggesting that long standing gingivitis increases the risk of loss of attachment and that prevention of gingival inflammation might reduce the prevalence of mild to moderate periodontitis. Several antimicrobials have been tested as adjuncts to mechanical plaque control in order to improve the results obtained with oral home care. Recent studies, including meta-analyses, have indicated that home care products containing chemical antimicrobials can provide gingivitis reduction beyond what can be accomplished with brushing and flossing. Particularly, formulations containing chlorhexidine, mouthrinses containing essential oils and triclosan/copolymer dentifrices have well documented clinical antiplaque and antigingivitis effects. In vivo microbiological tests have demonstrated the ability of these antimicrobial agents to penetrate the biofilm mass and to kill bacteria growing within biofilms. In addition, chemical antimicrobials can reach difficult-to-clean areas such as interproximal surfaces and can also impact the growth of biofilms on soft tissue. These agents have a positive track record of safety and their use does not seem to increase the levels of resistant species. Further, no study has been able to establish a correlation between mouthrinses containing alcohol and oral cancer. In summary, the adjunct use of chemical plaque control should be recommended to subjects with well documented difficulties in achieving proper biofilm control using only mechanical means.

  18. Identification and analysis of senile plaques using nuclear microscopy

    Science.gov (United States)

    Landsberg, J. P.; McDonald, B.; Roberts, J. M.; Grime, G. W.; Watt, F.

    1991-03-01

    The senile plaques and neuro-fibrillary tangles which form part of the pathology of Alzheimer's disease have come under increasing scrutiny over the last decade. In particular, much work has been done investigating their elemental composition. The suggestion that 75-100% of senile plaques with mature cores contain aluminium and silicon, probably in the form of alumino-silicates, has led to increasing speculation about the role of these elements in the disease. SPM preliminary studies suggest that aluminium and silicon are not present in as great a proportion of senile plaques as presented in the literature. The situation is complicated by the fact that airborne and solubilised salts of aluminium and silicon may be encountered as contamination. They have been found, for example, in granular or crystalline form in the Aristar grade organic laboratory reagents used for staining the tissue, and in the pure pioloform used to back the samples. The latest results from scans of stained and unstained Alzheimer tissue are presented.

  19. Computational Fluid Dynamics Analysis of the Effect of Plaques in the Left Coronary Artery

    Directory of Open Access Journals (Sweden)

    Thanapong Chaichana

    2012-01-01

    Full Text Available This study was to investigate the hemodynamic effect of simulated plaques in left coronary artery models, which were generated from a sample patient’s data. Plaques were simulated and placed at the left main stem and the left anterior descending (LAD to produce at least 60% coronary stenosis. Computational fluid dynamics analysis was performed to simulate realistic physiological conditions that reflect the in vivo cardiac hemodynamics, and comparison of wall shear stress (WSS between Newtonian and non-Newtonian fluid models was performed. The pressure gradient (PSG and flow velocities in the left coronary artery were measured and compared in the left coronary models with and without presence of plaques during cardiac cycle. Our results showed that the highest PSG was observed in stenotic regions caused by the plaques. Low flow velocity areas were found at postplaque locations in the left circumflex, LAD, and bifurcation. WSS at the stenotic locations was similar between the non-Newtonian and Newtonian models although some more details were observed with non-Newtonian model. There is a direct correlation between coronary plaques and subsequent hemodynamic changes, based on the simulation of plaques in the realistic coronary models.

  20. Therapeutic Effect and Safety of Ustekinumab for Plaque Psoriasis:A Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    Yi Liu; Jian-ping Gong; Wen-fang Li

    2014-01-01

    Objective To evaluate the efficacy and safety of ustekinumab in the therapy of plaque psoriasis. Methods Literatures published up to November 2013 were collected from Cochrane library, MEDLINE, and PubMed which were related with ustekinumab for plaque psoriasis. The efficacy was estimated using relative risk of Psoriasis Area and Severity Index (PASI) 75 response rate at the week 12 endpoint in clinical trials, and adverse effects were also analyzed. Meta-analysis was carried out by using Review Manager 5.1. Results Six randomized control trials consistent with the inclusion criteria were selected and reviewed. Ustekinumab 45 mg group and 90 mg group could get better therapeutic effect compared with the placebo group (all P0.05), except that infection rate in ustekinumab 45 mg group was higher than the placebo group (P=0.02). Conclusions Ustekinumab is an effective and safe therapeutic method for plaque psoriasis. However, further longer time analysis of safety is needed.

  1. Technical aspects of nuclear microprobe analysis of senile plaques from alzheimer patients

    Science.gov (United States)

    Larsson, N. P.-O.; Tapper, U. A. S.; Sturesson, K.; Odselius, R.; Brun, A.

    1990-04-01

    Alzheimer's disease, a common form of senile dementia, has been proposed to be caused by aluminium. One of the interesting structures to be studied, senile plaque cores in the brain, have centres of only about 10 μm. We have investigated the possibility of applying nuclear microprobes to sections containing senile plaques. An alternative staining procedure, TMToluidin blue staining using a spray technique, is also presented. An outline is given of a procedure for preparing senile plaque specimens for nuclear microprobe analysis. This includes a technique for accurate ion beam positioning, utilizing electron microscopy-grids. The subject may be of general interest since sample preparation is one of the most important aspects in microprobe analysis of biological matter.

  2. Laser-induced fluorescence: quantitative analysis of atherosclerotic plaque chemical content in human aorta

    Science.gov (United States)

    Dai, Erbin; Wishart, David; Khoury, Samir; Kay, Cyril M.; Jugdutt, Bodh I.; Tulip, John; Lucas, Alexandra

    1996-05-01

    We have been studying laser-induced fluorescence as a technique for identification of selected changes in the chemical composition of atherosclerotic plaque. Formulae for quantification of chemical changes have been developed based upon analysis of fluorescence emission spectra using multiple regression analysis and the principal of least squares. The intima of human aortic necropsy specimens was injected with chemical compounds present in atherosclerotic plaque. Spectra recorded after injection of selected chemical components found in plaque (collagen I, III, IV, elastin and cholesterol) at varying concentrations (0.01 - 1.0 mg) were compared with saline injection. A single fiber system was used for both fluorescence excitation (XeCl excimer laser, 308 nm, 1.5 - 2.0 mJ/ pulse, 5 Hz) and fluorescence emission detection. Average spectra for each chemical have been developed and the wavelengths of peak emission intensity identified. Curve fitting analysis as well as multiple regression analysis were used to develop formulae for assessment of chemical content. Distinctive identifying average curves were established for each chemical. Excellent correlations were identified for collagen I, III, and IV, elastin, and cholesterol (R2 equals 0.92 6- 0.997). Conclusions: (1) Fluorescence spectra of human aortas were significantly altered by collagen I, collagen III, elastin and cholesterol. (2) Fluorescence spectroscopic analysis may allow quantitative assessment of atherosclerotic plaque chemical content in situ.

  3. Computer-implemented system and method for automated and highly accurate plaque analysis, reporting, and visualization

    Science.gov (United States)

    Kemp, James Herbert (Inventor); Talukder, Ashit (Inventor); Lambert, James (Inventor); Lam, Raymond (Inventor)

    2008-01-01

    A computer-implemented system and method of intra-oral analysis for measuring plaque removal is disclosed. The system includes hardware for real-time image acquisition and software to store the acquired images on a patient-by-patient basis. The system implements algorithms to segment teeth of interest from surrounding gum, and uses a real-time image-based morphing procedure to automatically overlay a grid onto each segmented tooth. Pattern recognition methods are used to classify plaque from surrounding gum and enamel, while ignoring glare effects due to the reflection of camera light and ambient light from enamel regions. The system integrates these components into a single software suite with an easy-to-use graphical user interface (GUI) that allows users to do an end-to-end run of a patient record, including tooth segmentation of all teeth, grid morphing of each segmented tooth, and plaque classification of each tooth image.

  4. Immunohistochemical analysis of small plaque parapsoriasis: involvement of dendritic cells.

    Science.gov (United States)

    Zeybek, N Dilara; Asan, Esin; Erbil, A Hakan; Dagdeviren, Attila

    2008-01-01

    Small plaque parapsoriasis (SPP) is one of the cutaneous T-cell lymphoproliferative disorders. The aim of the present study was to show the antigenic profile of a subset of dendritic cells and lymphocytes in SPP in comparison with normal cells to provide data on the role of these two cell types in the pathogenesis of SPP. Skin biopsy specimens of lesions were obtained from 8 patients with SPP. Biopsies of the healthy skin from 9 control individuals were also analyzed. Immunohistochemistry was performed on the frozen tissue sections to reveal binding of anti-HLA Class II, anti-CD1a, anti-CD4, anti-CD8, anti-CD44, anti-CD45, and anti-CD68 monoclonal antibodies. There was a statistically significant increase in the number of CD1a(+), Langerhans cells (LCs), HLA-DR-immunoreactive and, CD1a-positive dermal dendritic cells and CD68(+) macrophages in the SPP group (p=0.008, 0.008, 0.002 and <0.0009, respectively). The number of lymphocytes positive for CD4, CD8 and CD45 was significantly higher than normal in the SPP group (p=0.015, <0.0009 and <0.0009, respectively). Our study demonstrates that both peptide- and lipid-based antigens are involved in the persistent antigenic exposure in SPP. Dendritic cells play a pivotal role in SPP by presenting antigens by both LC and dermal dendritic cells via MHC Class II and CD1a molecules. The CD68(+) macrophages are thought to be involved in the immune response in this pathology as an antigen-presenting cell.

  5. Mechanism of ceroid formation in atherosclerotic plaque: in situ studies using a combination of Raman and fluorescence spectroscopy

    Science.gov (United States)

    Haka, Abigail S.; Kramer, John R.; Dasari, Ramachandra R.; Fitzmaurice, Maryann

    2011-01-01

    Accumulation of the lipid-protein complex ceroid is a characteristic of atherosclerotic plaque. The mechanism of ceroid formation has been extensively studied, because the complex is postulated to contribute to plaque irreversibility. Despite intensive research, ceroid deposits are defined through their fluorescence and histochemical staining properties, while their composition remains unknown. Using Raman and fluorescence spectral microscopy, we examine the composition of ceroid in situ in aorta and coronary artery plaque. The synergy of these two types of spectroscopy allows for identification of ceroid via its fluorescence signature and elucidation of its chemical composition through the acquisition of a Raman spectrum. In accordance with in vitro predictions, low density lipoprotein (LDL) appears within the deposits primarily in its peroxidized form. The main forms of modified LDL detected in both coronary artery and aortic plaques are peroxidation products from the Fenton reaction and myeloperoxidase-hypochlorite pathway. These two peroxidation products occur in similar concentrations within the deposits and represent ∼40 and 30% of the total LDL (native and peroxidized) in the aorta and coronary artery deposits, respectively. To our knowledge, this study is the first to successfully employ Raman spectroscopy to unravel a metabolic pathway involved in disease pathogenesis: the formation of ceroid in atherosclerotic plaque. PMID:21280898

  6. Quantitative analysis of ultrasound contrast flow behavior in carotid plaque neovasculature.

    Science.gov (United States)

    Hoogi, Assaf; Akkus, Zeynettin; van den Oord, Stijn C H; ten Kate, Gerrit L; Schinkel, Arend F L; Bosch, Johan G; de Jong, Nico; Adam, Dan; van der Steen, Antonius F W

    2012-12-01

    Intraplaque neovascularization is considered as an important indication for plaque vulnerability. We propose a semiautomatic algorithm for quantification of neovasculature, thus, enabling assessment of plaque vulnerability. The algorithm detects and tracks contrast spots using multidimensional dynamic programming. Classification of contrast tracks into blood vessels and artifacts was performed. The results were compared with manual tracking, visual classification and maximal intensity projection. In 28 plaques, 97% of the contrast spots were detected. In 89% of the objects, the automatic tracking determined the contrast motion with an average distance of less than 0.5 mm from the manual marking. Furthermore, 75% were correctly classified into artifacts and vessels. The automated neovascularization grading agreed within 1 grade with visual analysis in 91% of the cases, which was comparable to the interobserver variability of visual grading. These results show that the method can successfully quantify features that are linked to vulnerability of the carotid plaque. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  7. Short term effect of mechanical plaque control on salivary concentration of S. mutans and lactobacilli.

    Science.gov (United States)

    Wikner, S

    1986-08-01

    All visible plaque was professionally removed from teeth of 40 children who were highly infected with S. mutans and lactobacilli. Shortly before and after the removal of plaque the concentrations of those bacteria were assessed in saliva stimulated by chewing. S. mutans and lactobacilli correlated well at baseline but not after plaque elimination, e.g. more than 80% of children who were heavily infected with S. mutans could be identified by a lactobacillus test at baseline. After the elimination of plaque, the mean concentration of S. mutans dropped by 64% but lactobacilli remained unchanged. The results indicate that oral hygiene measures taken by the patient prior to sampling of saliva may mask the true concentration of salivary S. mutans and complicate the identification of high caries risk patients.

  8. Fluorescence spectrum analysis of atherosclerotic plaque using doxycycline.

    Science.gov (United States)

    Miyagi, M; Nakajima, H; Katoh, T; Usui, M; Amemiya, T; Nagai, Y; Ibukiyama, C

    1999-05-01

    Using doxycycline (DOXY), fluorescence spectrum analysis was performed on arteriosclerotic lesions, and the efficacy of this method was examined in basic and clinical studies. In the basic study, DOXY 50 mg was administered intravenously to arteriosclerotic rabbits, and the thoracoabdominal aorta removed. Fluorescence spectral analysis was performed on each specimen, and the fluorescence spectral pattern, peak intensity and degree of intimal hypertrophy were studied. In the clinical study, DOXY 200 mg was administered intravenously to 6 human subjects with stable angina and coronary arterial stenosis of greater than 90%, and coronary angiography, coronary angioscopy and fluorescence spectral analysis were performed. DOXY accumulation in the arteriosclerotic intima of rabbit aortae was confirmed. The fluorescence spectrum was monomodal, peaking at around 532 nm. In the noncalcification group, significant correlation was observed between peak intensity and arteriosclerotic intimal thickness. Using DOXY as a fluorescent marker, it was possible to assess the level of arteriosclerotic intimal hypertrophy. Clinically, it was possible to obtain the DOXY spectrum of the coronary arteries.

  9. Volumetric Analysis of Carotid Plaque Components and Cerebral Microbleeds: A Correlative Study.

    Science.gov (United States)

    Saba, Luca; Sanfilippo, Roberto; di Martino, Michele; Porcu, Michele; Montisci, Roberto; Lucatelli, Pierleone; Anzidei, Michele; Francone, Marco; Suri, Jasjit S

    2017-03-01

    The purpose of this work was to explore the association between carotid plaque volume (total and the subcomponents) and cerebral microbleeds (CMBs). Seventy-two consecutive (male 53; median age 64) patients were retrospectively analyzed. Carotid arteries were studied by using a 16-detector-row computed tomography scanner whereas brain was explored with a 1.5 Tesla system. CMBs were studied using a T2*-weighted gradient-recalled echo sequence. CMBs were classified as from absent (grade 1) to severe (grade 4). Component types of the carotid plaque were defined according to the following Hounsfield unit (HU) ranges: lipid less than 60 HU; fibrous tissue from 60 to 130 HU; calcification greater than 130 HU, and plaque volumes of each component were calculated. Each carotid artery was analyzed by 2 observers. The prevalence of CMBs was 35.3%. A statistically significant difference was observed between symptomatic (40%) and asymptomatic (11%) patients (P value = .001; OR = 6.07). Linear regression analysis demonstrated an association between the number of CMBs and the symptoms (P = .0018). Receiver operating characteristics curve analysis found an association between the carotid plaque subcomponents and CMBs (Az = .608, .621, and .615 for calcified, lipid, and mixed components, respectively), and Mann-Whitney test confirmed this association in particular for the lipid components (P value = .0267). Results of this study confirm the association between CMBs and symptoms and that there is an increased number of CMBs in symptomatic patients. Moreover, we found that an increased volume of the fatty component is associated with the presence and number of CMBs. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  10. Chronic over-expression of heat shock protein 27 attenuates atherogenesis and enhances plaque remodeling: a combined histological and mechanical assessment of aortic lesions.

    Directory of Open Access Journals (Sweden)

    Charles M Cuerrier

    Full Text Available AIMS: Expression of Heat Shock Protein-27 (HSP27 is reduced in human coronary atherosclerosis. Over-expression of HSP27 is protective against the early formation of lesions in atherosclerosis-prone apoE(-/- mice (apoE(-/-HSP27(o/e - however, only in females. We now seek to determine if chronic HSP27 over-expression is protective in a model of advanced atherosclerosis in both male and female apoE(-/- mice. METHODS AND RESULTS: After 12 weeks on a high fat diet, serum HSP27 levels rose more than 16-fold in male and female apoE(-/-HSP27(o/e mice, although females had higher levels than males. Relative to apoE(-/- mice, female apoE(-/-HSP27(o/e mice showed reductions in aortic lesion area of 35% for en face and 30% for cross-sectional sinus tissue sections - with the same parameters reduced by 21% and 24% in male cohorts; respectively. Aortic plaques from apoE(-/-HSP27(o/e mice showed almost 50% reductions in the area occupied by cholesterol clefts and free cholesterol, with fewer macrophages and reduced apoptosis but greater intimal smooth muscle cell and collagen content. The analysis of the aortic mechanical properties showed increased vessel stiffness in apoE(-/-HSP27(o/e mice (41% in female, 34% in male compare to apoE(-/- counterparts. CONCLUSIONS: Chronic over-expression of HSP27 is atheroprotective in both sexes and coincides with reductions in lesion cholesterol accumulation as well as favorable plaque remodeling. These data provide new clues as to how HSP27 may improve not only the composition of atherosclerotic lesions but potentially their stability and resilience to plaque rupture.

  11. Identification of two genes potentially associated in iron-heme homeostasis in human carotid plaque using microarray analysis

    Indian Academy of Sciences (India)

    Hanène Ayari; Giampiero Bricca

    2013-06-01

    Classic characteristics are poor predictors of the risk of thromboembolism. Thus, better markers for the carotid atheroma plaque formation and symptom causing are needed. Our objective was to study by microarray analysis gene expression of genes involved in homeostasis of iron and heme in carotid atheroma plaque from the same patient. mRNA gene expression was measured by an Affymetrix GeneChip Human Gene 1.0 ST arrays (Affymetrix, Santa Clara, CA, USA) using RNA prepared from 68 specimens of endarteriectomy from 34 patients. Two genes involved in iron-heme homeostasis, CD163 and heme oxygenase (HO-1), were analysed in 34 plaques. CD163 (2.18, =1.45E−08) and HO-1 (fold-change 2.67, =2.07E−09) mRNAs were induced. We suggest that atheroma plaques show a more pronounced induction of CD163 and HO-1. Although further evidence is needed, our results support previous data. To our knowledge, this is the first report comparing gene expression between intact arterial tissue and carotid plaque using microarray analysis.

  12. Cystatin C is Associated With Plaque Phenotype and Plaque Burden

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    Yufeng Wen

    2016-03-01

    Full Text Available Background/Aims: The relationship between carotid artery plaque burden, phenotype and serum cystatin C at normal and impaired renal function is still unclear. Methods: Demographic characteristics, carotid ultrasonography and other relevant information of 1,477 patients were collected. The association of carotid artery plaque burden, plaque phenotype with serum cystatin C was evaluated by strategy analysis based on renal function. Results: Serum cystatin C (OR=2.05, 95% CI: 1.83-2.29, POR=1.60, 95%CI: 1.43-1.78, POR=1.21, 95%CI: 1.10-1.32, P Conclusion: In normal renal function, serum cystatin C may confer stability of plaques. In mildly impaired renal function, serum cystatin C is a risk predictor of plaques. In normal renal function circumstances, serum cystatin C may benefit to the stability of plaques. In mild impaired renal function circumstances, serum cystatin C are a risk predictors of plaques.

  13. The expanding indications for virtual histology intravascular ultrasound for plaque analysis prior to carotid stenting.

    Science.gov (United States)

    Schiro, B J; Wholey, M H

    2008-12-01

    Complications of carotid artery stenting (CAS), including stroke, remain relatively high when compared with carotid endarterectomy (CEA). Current selection criteria for patients undergoing CAS are based predominately on surgical risk related to other comorbidities. Little attention is given to the morphology of the atherosclerotic plaque, although studies have shown that extensive variability exists which confers certain risks for plaque vulnerability. Virtual Histology intravascular ultrasound (VH IVUS) offers a unique method of assessing plaque morphology prior to CAS. Herein, the authors review the concepts of atherosclerotic plaque morphology and discuss the background of VH IVUS and illustrate its use in the carotid system. With selection of the appropriate patient and the appropriate plaque, more favorable outcomes of CAS may be achieved which will solidify its place as a frontline treatment of carotid vascular disease.

  14. Comparative analysis between hard- and soft-filament toothbrushes related to plaque removal and gingival abrasion.

    Science.gov (United States)

    Carvalho, Rosimary de Sousa; Rossi, Vanessa; Weidlich, Patrícia; Oppermann, Rui Vicente

    2007-01-01

    The aim of this split-mouth, examiner-blind study was to compare the dental plaque removal and incidence of gingival abrasion associated with the use of hard- and soft-filament toothbrushes. The test group consisted of 20 non-dental students, mean age 25 years. After a three-day period of plaque accumulation following the use of a disclosing solution, the Quigley-Hein Plaque Index was recorded, while the presence of gingival abrasion was measured from photographs. Pairs of quadrants 1-3 and 2-4 were allocated to supervised brushing with hard- or soft-filament toothbrushes for 30 seconds, limited to the buccal aspects of the teeth. Plaque levels and gingival abrasion were again assessed. Initial and final values of the plaque index and the mean number of abrasions were compared with the Friedman and Wilcoxon tests (p < or = 0.05). Plaque indices were reduced significantly from a baseline of 4.12 in both groups to 1.21 after the use of hard-filament toothbrushes, and to 1.67 after the use of soft-filament toothbrushes. The use of hard-filament toothbrushes resulted in a significantly higher mean number of lesions when compared to the soft-filament toothbrushes; 11.6 and 7.9, respectively (p = 0.018). Hard-filament toothbrushes remove more plaque than soft filament brushes, but also cause a higher number of gingival abrasions.

  15. Numerical analysis of the cooling effect of blood over inflamed atherosclerotic plaque.

    Science.gov (United States)

    Kim, Taehong; Ley, Obdulia

    2008-06-01

    Atherosclerotic plaques with high likelihood of rupture often show local temperature increase with respect to the surrounding arterial wall temperature. In this work, atherosclerotic plaque temperature was numerically determined during the different levels of blood flow reduction produced by the introduction of catheters at the vessel lumen. The temperature was calculated by solving the energy equation and the Navier-Stokes equations in 2D idealized arterial models. Arterial wall temperature depends on three basic factors: metabolic activity of the inflammatory cells embedded in the plaque, heat convection due to luminal blood flow, and heat conduction through the arterial wall and plaque. The calculations performed serve to simulate transient blood flow reduction produced by the presence of thermography catheters used to measure arterial wall temperature. The calculations estimate the spatial and temporal alterations in the cooling effect of blood flow and plaque temperature during the measurement process. The mathematical model developed provides a tool for analyzing the contribution of factors known to affect heat transfer at the plaque surface. Blood flow reduction leads to a nonuniform temperature increase ranging from 0.1 to 0.25 degrees Celsius in the plaque/lumen interface of the arterial geometries considered in this study. The temperature variation as well as the Nusselt number calculated along the plaque surface strongly depended on the arterial geometry and distribution of inflammatory cells. The calculations indicate that the minimum required time to obtain a steady temperature profile after arterial occlusion is 6 s. It was seen that in arteries with geometries involving bends, the temperature profiles appear asymmetrical and lean toward the downstream edge of the plaque.

  16. Advanced computed tomographic anatomical and morphometric plaque analysis for prediction of fractional flow reserve in intermediate coronary lesions

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    Opolski, Maksymilian P., E-mail: opolski.mp@gmail.com [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Kepka, Cezary, E-mail: c.kepka@ikard.pl [Department of Coronary and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Achenbach, Stephan, E-mail: stephan.achenbach@uk-erlangen.de [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Erlangen (Germany); Pregowski, Jerzy, E-mail: jerzypregowski74@gmail.com [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Kruk, Mariusz, E-mail: mariuszkruk2000@yahoo.com [Department of Coronary and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Staruch, Adam D., E-mail: adstarman@gmail.com [Medical University of Warsaw, Warsaw (Poland); Kadziela, Jacek, E-mail: j.kadziela@ikard.pl [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Ruzyllo, Witold, E-mail: w.ruzyllo@ikard.pl [Department of Coronary and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Witkowski, Adam, E-mail: witkowski@hbz.pl [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland)

    2014-01-15

    Objective: To determine the application of advanced coronary computed tomography angiography (CCTA) plaque analysis for predicting invasive fractional flow reserve (FFR) in intermediate coronary lesions. Methods: Sixty-one patients with 71 single intermediate coronary lesions (≥50–80% stenosis) on CCTA prospectively underwent coronary angiography and FFR. Advanced anatomical and morphometric plaque analysis was performed based on CCTA data set to determine optimal criteria for significant flow impairment. A significant stenosis was defined as FFR ≤ 0.80. Results: FFR averaged 0.85 ± 0.09, and 19 lesions (27%) were functionally significant. FFR correlated with minimum lumen area (MLA) (r = 0.456, p < 0.001), minimum lumen diameter (MLD) (r = 0.326, p = 0.006), reference lumen diameter (RLD) (r = 0.245, p = 0.039), plaque burden (r = −0.313, p = 0.008), lumen area stenosis (r = −0.305, p = 0.01), lesion length (r = −0.692, p < 0.001), and plaque volume (r = −0.668, p < 0.001). There was no relationship between FFR and CCTA morphometric plaque parameters. By multivariate analysis the independent predictors of FFR were lesion length (beta = −0.581, p < 0.001), MLA (beta = 0.360, p = 0.041), and RLD (beta = −0.255, p = 0.036). The optimal cutoffs for lesion length, MLA, MLD, RLD, and lumen area stenosis were >18.5 mm, ≤3.0 mm{sup 2}, ≤2.1 mm, ≤3.2 mm, and >69%, respectively (max. sensitivity: 100% for MLA, max. specificity: 79% for lumen area stenosis). Conclusions: CCTA predictors for FFR support the mathematical relationship between stenosis pressure drop and coronary flow. CCTA could prove to be a useful rule-out test for significant hemodynamic effects of intermediate coronary stenoses.

  17. Phylogenetic analysis shows that Neolithic slate plaques from the southwestern Iberian Peninsula are not genealogical recording systems.

    Directory of Open Access Journals (Sweden)

    Daniel García Rivero

    Full Text Available Prehistoric material culture proposed to be symbolic in nature has been the object of considerable archaeological work from diverse theoretical perspectives, yet rarely are methodological tools used to test the interpretations. The lack of testing is often justified by invoking the opinion that the slippery nature of past human symbolism cannot easily be tackled by the scientific method. One such case, from the southwestern Iberian Peninsula, involves engraved stone plaques from megalithic funerary monuments dating ca. 3,500-2,750 B.C. (calibrated age. One widely accepted proposal is that the plaques are ancient mnemonic devices that record genealogies. The analysis reported here demonstrates that this is not the case, even when the most supportive data and techniques are used. Rather, we suspect there was a common ideological background to the use of plaques that overlay the southwestern Iberian Peninsula, with little or no geographic patterning. This would entail a cultural system in which plaque design was based on a fundamental core idea, with a number of mutable and variable elements surrounding it.

  18. Phylogenetic analysis shows that Neolithic slate plaques from the southwestern Iberian Peninsula are not genealogical recording systems.

    Science.gov (United States)

    García Rivero, Daniel; O'Brien, Michael J

    2014-01-01

    Prehistoric material culture proposed to be symbolic in nature has been the object of considerable archaeological work from diverse theoretical perspectives, yet rarely are methodological tools used to test the interpretations. The lack of testing is often justified by invoking the opinion that the slippery nature of past human symbolism cannot easily be tackled by the scientific method. One such case, from the southwestern Iberian Peninsula, involves engraved stone plaques from megalithic funerary monuments dating ca. 3,500-2,750 B.C. (calibrated age). One widely accepted proposal is that the plaques are ancient mnemonic devices that record genealogies. The analysis reported here demonstrates that this is not the case, even when the most supportive data and techniques are used. Rather, we suspect there was a common ideological background to the use of plaques that overlay the southwestern Iberian Peninsula, with little or no geographic patterning. This would entail a cultural system in which plaque design was based on a fundamental core idea, with a number of mutable and variable elements surrounding it.

  19. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

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    João L. A. A. Falcão

    2015-04-01

    Full Text Available Background: The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. Objectives: We compared 64-slice multidetector computed tomography (MDCT with gray scale intravascular ultrasound (IVUS for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. Methods: The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient. A coronary plaque was diagnosed in segments with plaque burden > 40%. Results: At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01. However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. Conclusions: In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.

  20. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

    Energy Technology Data Exchange (ETDEWEB)

    Falcão, João L. A. A.; Falcão, Breno A. A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil); Gurudevan, Swaminatha V. [Cedars-Sinai Heart Institute, Los Angeles, California, USA (United States); Campos, Carlos M.; Silva, Expedito R.; Kalil-Filho, Roberto; Rochitte, Carlos E.; Shiozaki, Afonso A.; Coelho-Filho, Otavio R.; Lemos, Pedro A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil)

    2015-04-15

    The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.

  1. Ultraviolet Phototherapy Management of Moderate-to-Severe Plaque Psoriasis: An Evidence-Based Analysis.

    Science.gov (United States)

    2009-01-01

    The purpose of this evidence based analysis was to determine the effectiveness and safety of ultraviolet phototherapy for moderate-to-severe plaque psoriasis. The specific research questions for the evidence review were as follows: What is the safety of ultraviolet phototherapy for moderate-to-severe plaque psoriasis?What is the effectiveness of ultraviolet phototherapy for moderate-to-severe plaque psoriasis? TARGET POPULATION AND CONDITION Psoriasis is a common chronic, systemic inflammatory disease affecting the skin, nails and occasionally the joints and has a lifelong waning and waxing course. It has a worldwide occurrence with a prevalence of at least 2% of the general population, making it one of the most common systemic inflammatory diseases. The immune-mediated disease has several clinical presentations with the most common (85% - 90%) being plaque psoriasis. Characteristic features of psoriasis include scaling, redness, and elevation of the skin. Patients with psoriasis may also present with a range of disabling symptoms such as pruritus (itching), pain, bleeding, or burning associated with plaque lesions and up to 30% are classified as having moderate-to-severe disease. Further, some psoriasis patients can be complex medical cases in which diabetes, inflammatory bowel disease, and hypertension are more likely to be present than in control populations and 10% also suffer from arthritis (psoriatic arthritis). The etiology of psoriasis is unknown but is thought to result from complex interactions between the environment and predisposing genes. Management of psoriasis is related to the extent of the skin involvement, although its presence on the hands, feet, face or genitalia can present challenges. Moderate-to-severe psoriasis is managed by phototherapy and a range of systemic agents including traditional immunosuppressants such as methotrexate and cyclospsorin. Treatment with modern immunosuppressant agents known as biologicals, which more specifically

  2. Intraplaque hemorrhage is associated with higher structural stresses in human atherosclerotic plaques: an in vivo MRI-based 3d fluid-structure interaction study

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    Canton Gador

    2010-12-01

    Full Text Available Abstract Background Studies using medical images have shown that intraplaque hemorrhage may accelerate plaque progression and may produce a stimulus for atherosclerosis development by increasing lipid core and plaque volume and creating new destabilizing factors. Image-based 3D computational models with fluid-structure interactions (FSI will be used to perform plaque mechanical analysis and investigate possible associations between intraplaque hemorrhage and both plaque wall stress (PWS and flow shear stress (FSS. Methods In vivo MRI data of carotid plaques from 5 patients with intraplaque hemorrhage confirmed by histology were acquired. 3D multi-component FSI models were constructed for each plaque to obtain mechanical stresses. Plaque Wall Stress (PWS and Flow Shear Stress (FSS were extracted from all nodal points on the lumen surface of each plaque for analysis. Results The mean PWS value from all hemorrhage nodes of the 5 plaques combined was higher than that from non-hemorrhage nodes (75.6 versus 68.1 kPa, P = 0.0003. The mean PWS values from hemorrhage nodes for each of the 5 plaques were all significantly higher (5 out of 5 than those from non-hemorrhage nodes (P 2, P = 0.0002. However, the mean flow shear stress values from individual cases showed mixed results: only one out of five plaques showed mean FSS value from hemorrhage nodes was higher than that from non-hemorrhage nodes; three out of five plaques showed that their mean FSS values from hemorrhage nodes were lower than those from non-hemorrhage nodes; and one plaque showed that the difference had no statistical significance. Conclusion The results of this study suggested that intraplaque hemorrhage nodes were associated with higher plaque wall stresses. Compared to flow shear stress, plaque wall stress has a better correlation with plaque component feature (hemorrhage linked to plaque progression and vulnerability. With further validation, plaque stress analysis may provide

  3. APP with Kunitz type protease inhibitor domain (KPI) correlates with neuritic plaque density but not with cortical synaptophysin immunoreactivity in Alzheimer's disease and non-demented aged subjects: a multifactorial analysis.

    Science.gov (United States)

    Zhan, S S; Sandbrink, R; Beyreuther, K; Schmitt, H P

    1995-01-01

    The formation of beta A4 amyloid protein in neuritic plaques in Alzheimer's disease (AD) and advanced age is a complex process that involves a number of both cellular and molecular mechanisms, the interrelations of which are not yet completely understood. We have examined quantitatively, in AD and aged controls an extended spectrum of amyloid plaque-related cellular and molecular factors and the cortical synaptophysin immunoreactivity (synaptic density) in order to check for interrelations between them by multifactorial analysis. In 3 cases of senile dementia of the Alzheimer type (SDAT) aged 72, 80 and 82 years, and 9 controls aged 43-88 (mean age 65) years, the cortical synaptophysin immunoreactivity was assessed, together with the numbers of neurons, astrocytes and microglial cells, senile plaques, of tangle-bearing neurons, and the amount of beta A4 amyloid precursor protein (APP) with and without the Kunitz type serine protease inhibitor (KPI) domain. The main results were: APP including the KPI domain (KPI-APP) correlated with the number of neuritic plaques, regardless of whether they occurred in SDAT or non-demented controls. There was no significant difference in the amount of KPI-APP between SDAT and controls. Conversely, APP695 (without KPI) was significantly reduced in SDAT. KPI-APP did not correlate with the synaptophysin immunoreactivity (RGVA), while APP695 showed a significant correlation with the latter in all evaluations. It also correlated with the neuron counts, which was not true for KPI-APP. These results support previous findings indicating that KPI-APP is an important local factor for amyloid deposition in the neuritic plaques, both in AD and in non-demented aged people. On the contrary, KPI-APP does not seem to be significantly involved in the mechanisms of synaptic change outside of the plaques.

  4. RNAseq based transcriptomics study of SMCs from carotid atherosclerotic plaque: BMP2 and IDs proteins are crucial regulators of plaque stability.

    Science.gov (United States)

    Alloza, Iraide; Goikuria, Haize; Idro, Juan Luis; Triviño, Juan Carlos; Fernández Velasco, José María; Elizagaray, Elena; García-Barcina, María; Montoya-Murillo, Genoveva; Sarasola, Esther; Vega Manrique, Reyes; Freijo, Maria Del Mar; Vandenbroeck, Koen

    2017-06-14

    Carotid artery atherosclerosis is a risk factor to develop cerebrovascular disease. Atheroma plaque can become instable and provoke a cerebrovascular event or else remain stable as asymptomatic type. The exact mechanism involved in plaque destabilization is not known but includes among other events smooth muscle cell (SMC) differentiation. The goal of this study was to perform thorough analysis of gene expression differences in SMCs isolated from carotid symptomatic versus asymptomatic plaques. Comparative transcriptomics analysis of SMCs based on RNAseq technology identified 67 significant differentially expressed genes and 143 significant differentially expressed isoforms in symptomatic SMCs compared with asymptomatic. 37 of top-scoring genes were further validated by digital PCR. Enrichment and network analysis shows that the gene expression pattern of SMCs from stable asymptomatic plaques is suggestive for an osteogenic phenotype, while that of SMCs from unstable symptomatic plaque correlates with a senescence-like phenotype. Osteogenic-like phenotype SMCs may positively affect carotid atheroma plaque through participation in plaque stabilization via bone formation processes. On the other hand, plaques containing senescence-like phenotype SMCs may be more prone to rupture. Our results substantiate an important role of SMCs in carotid atheroma plaque disruption.

  5. A Meta Analysis and Hierarchical Classification of HU-Based Atherosclerotic Plaque Characterization Criteria

    NARCIS (Netherlands)

    Kristanto, Wisnumurti; van Ooijen, Peter M. A.; Jansen-van der Weide, Marijke C.; Vliegenthart, Rozemarijn; Oudkerk, Matthijs

    2013-01-01

    Background: Many computed tomography (CT) studies have reported that lipid-rich, presumably rupture-prone atherosclerotic plaques can be characterized according to their Hounsfield Unit (HU) value. However, the published HU-based characterization criteria vary considerably. The present study aims to

  6. Comparative analysis of cell proliferation ratio in plaque and erosive oral lichen planus: An immunohistochemical study

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    C Pramod Redder

    2014-01-01

    Full Text Available Background: Proliferating cell nuclear antigen (PCNA is a nuclear protein synthesized in the late G1 and S-phase of the cell cycle. Detection of this protein represents a useful marker of the proliferation status of lesions. This study has been carried out to evaluate the cell proliferation rate in oral lichen planus (OLP and comparison between plaque and erosive lichen planus, which indicates the potential for malignant transformation. Materials and Methods: This study was comprised of 64 cases of histologically proven lichen planus, out of which 32 cases of plaque and erosive each was taken. Two sections were taken from each, one for H and E staining to verify histological diagnosis according to Eisenberg criteria, other sections were stained according to super sensitive polymer horse radish peroxidise method for identifying immunohistochemical expression of PCNA. Data were statistically analyzed by Tukey high-range statistical domain test. Statistically significant P value was considered <0.05. Results: In two types of lichen planus, erosive type (66.86% showed higher expression of PCNA followed by plaque (17.07%. Overall, P value was <0.001, which was statistically significant. It indicates that proliferation activity is more in erosive lichen planus followed by plaque type, which ultimately results in increased rate of malignant transformation. Conclusion: PCNA is a good nuclear protein marker to evaluate the proliferation status of OLP. Out of the two types of lichen planus, erosive type possesses more proliferative ratio and chances of malignant change is more in this type. It emphasizes the importance of long-term follow-up with erosive type when compared with plaque type.

  7. Analysis of gingival plaque index and oral hygiene of patients with regard to smoking

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    Patrícia Petromili Nordi Sasso Garcia

    2008-01-01

    Full Text Available Objective: To make a clinical evaluation of periodontal alterations caused by cigarettes in smoker and non-smoker patients from two aspects: gingival plaque index and oral hygiene. Methods: Eighty patients of both sexes, ranging between 20 and 50 years of age, were selected and divided into four experimental groups (non-smoker patients without esthetic restorations, non-smoker patients with esthetic restorations, smoker patients without esthetic restorations, smoker patients with esthetic restorations. Results: The patients without restorations, irrespective of whether they were smokers or not, presented a lower gingival plaque index than the patients with restorations; that is, the presence of restorations exerts a strong influence on the increase in bacterial and gingival plaque indexes. With regard to oral hygiene, of the 40 smoker patients examined, many had been smoking for many years; in the majority of cases, around 20 cigarettes/day. Of the 80 patients examined (smokers and non-smokers, around 50% informed that they brushed their teeth three times a day, and 55 patients (over 50% informed that they visited the dentist periodically. Of the 80 patients examined (smokers and non-smokers, only 17 returned to the dental consulting room every six months, while 26 patients informed that they went once a year. Balance was also found between smokers and non-smokers with regard to the presence of bad breath. (halitosis Conclusion: Restorations had a strong influence on the increase in the bacterial and gingival plaque indexes, and over 50% of the patients examined informed that they visited the dentist periodically. As regards the presence of bad breath, it was found that around 40% of patients affirmed being aware of it.

  8. A Finite Difference Numerical Analysis of Heat Transfer in Atheromatous Plaque for Percutaneous Transluminal Microwave Angioplasty

    Science.gov (United States)

    1990-06-01

    method for placing a catheter into the vascular system by surgical exposure of a blood vessel or percutaneous technique was developed by S.I. Seldinger ...angioplasty method is a new technique that has a tremendous potential for selectively heating atheromatous plaques in arteries with minimal thermal...well as reduced medical expenses associated with this procedure. Modern angioplasty techniques are the by-products of two important technological

  9. Quantitative analysis of monocyte subpopulations in murine atherosclerotic plaques by multiphoton microscopy.

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    Abigail S Haka

    Full Text Available The progressive accumulation of monocyte-derived cells in the atherosclerotic plaque is a hallmark of atherosclerosis. However, it is now appreciated that monocytes represent a heterogeneous circulating population of cells that differ in functionality. New approaches are needed to investigate the role of monocyte subpopulations in atherosclerosis since a detailed understanding of their differential mobilization, recruitment, survival and emigration during atherogenesis is of particular importance for development of successful therapeutic strategies. We present a novel methodology for the in vivo examination of monocyte subpopulations in mouse models of atherosclerosis. This approach combines cellular labeling by fluorescent beads with multiphoton microscopy to visualize and monitor monocyte subpopulations in living animals. First, we show that multiphoton microscopy is an accurate and timesaving technique to analyze monocyte subpopulation trafficking and localization in plaques in excised tissues. Next, we demonstrate that multiphoton microscopy can be used to monitor monocyte subpopulation trafficking in atherosclerotic plaques in living animals. This novel methodology should have broad applications and facilitate new insights into the pathogenesis of atherosclerosis and other inflammatory diseases.

  10. Comparison of the use of different modes of mechanical oral hygiene in prevention of plaque and gingivitis.

    NARCIS (Netherlands)

    Rosema, N.A.; Timmerman, M.F.; Versteeg, P.A.; Palenstein Helderman, W.H. van; Velden, U. van den; Weijden, G.A. van der

    2008-01-01

    BACKGROUND: The objective of this study was to evaluate the effect of an oscillating/rotating/pulsating powered toothbrush on plaque and gingivitis prevention over a 9-month period. METHODS: The study had an examiner-masked, randomized, three-group parallel design. A total of 122 subjects >or= 18

  11. Three-dimensional imaging MS of lipids in atherosclerotic plaques: Open-source methods for reconstruction and analysis.

    Science.gov (United States)

    Patterson, Nathan H; Doonan, Robert J; Daskalopoulou, Stella S; Dufresne, Martin; Lenglet, Sébastien; Montecucco, Fabrizio; Thomas, Aurélien; Chaurand, Pierre

    2016-06-01

    Three-dimensional MALDI imaging MS (IMS) is a growing branch of IMS still requiring developments in methodology and technology to make the technique routinely accessible. Many challenges are simply a matter of producing 3D reconstructions and interpreting them in a timely fashion. In this aim and using analysis of lipids from atherosclerotic plaques from a human carotid and mouse aortic sinuses, we describe 3D reconstruction methods using open-source software that provides high-quality visualization and rapid interpretation through multivariate segmentation of the 3D IMS data. Multiple datasets were generated for each sample and we provide insight into simple means to correlate the separate datasets.

  12. Biomechanics and inflammation in atherosclerotic plaque erosion and plaque rupture: implications for cardiovascular events in women.

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    Ian C Campbell

    Full Text Available Although plaque erosion causes approximately 40% of all coronary thrombi and disproportionally affects women more than men, its mechanism is not well understood. The role of tissue mechanics in plaque rupture and regulation of mechanosensitive inflammatory proteins is well established, but their role in plaque erosion is unknown. Given obvious differences in morphology between plaque erosion and rupture, we hypothesized that inflammation in general as well as the association between local mechanical strain and inflammation known to exist in plaque rupture may not occur in plaque erosion. Therefore, our objective was to determine if similar mechanisms underlie plaque rupture and plaque erosion.We studied a total of 74 human coronary plaque specimens obtained at autopsy. Using lesion-specific computer modeling of solid mechanics, we calculated the stress and strain distribution for each plaque and determined if there were any relationships with markers of inflammation. Consistent with previous studies, inflammatory markers were positively associated with increasing strain in specimens with rupture and thin-cap fibroatheromas. Conversely, overall staining for inflammatory markers and apoptosis were significantly lower in erosion, and there was no relationship with mechanical strain. Samples with plaque erosion most closely resembled those with the stable phenotype of thick-cap fibroatheromas.In contrast to classic plaque rupture, plaque erosion was not associated with markers of inflammation and mechanical strain. These data suggest that plaque erosion is a distinct pathophysiological process with a different etiology and therefore raises the possibility that a different therapeutic approach may be required to prevent plaque erosion.

  13. Coronary plaque characterization of nonculprit or nontarget lesions assessed by analysis of in vivo intracoronary ultrasound radio-frequency data

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-liang; ZHANG Jiao; MA Dong-xing; LUO Jian-ping; YANG Sheng-li; HAN Wei; LIU Ying; JING Li-min; MENG Rong-ying

    2009-01-01

    Background Unheralded sudden death and acute myocardial infarction are common manifestations of coronary atherosclerosis. Such events are related to thrombotic occlusion at the site of non-flow limiting atheroscterotic plaques in epicardial coronary arteries. This study aimed to assess plaque characterization of nonculprit lesions in patients with acute coronary syndrome (ACS) compared with those with stable angina pectoris (SAP) determined by analysis of intravascular ultrasound (IVUS) radiofrequency (RF) data.Methods In 81 patients, nonculprit vessels with <50% diameter stenosis and nontarget segment of culprit vessels with <50% diameter stenosis were studied with IVUS. Tissue maps were reconstructed from RF data using IVUS-Virtual Histology software.Results Mean lipid core percentage was significantly higher in patients with ACS than in those with SAP ((25.78±6.30)% vs (9.11±4.90)%, P <0.001). In addition, patients with SAP showed more fibrotic vessels ((59.66±16.87)% vs (49.07±10.20)%, P <0.001). There was no significant difference in either mean calcium ((4.37±2.40)% vs (5.12±3.00)%, P=0.225) or fibrolipid ((24.94±9.40)% vs (25.82±13.60)%, P=0.731) percentages in nonculprit vessels, but the mean calcium percentage was significantly higher in nontarget lesions of culprit vessels ((5.51±3.29)% vs (3.57±2.10)%, P=0.003). In addition, there was a positive correlation between lipid core and remodeling index (RI) (r=0.847, P<0.001) and a negative correlation between fibrous tissue and RI (r=-0.946, P<0.001).Conclusions In this study, in both nonculprit vessels and nontarget lesion of culprit vessels, plaque characterization of nonculprit lesions determined by spectral analysis of IVUS RF data was significantly different in patients with ACS. The percentage of lipid core was significantly higher in patients with ACS than in those with SAP. Conversely, SAP patients showed more fibrotic content. In vivo plaque composition and morphological changes were

  14. Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque

    Directory of Open Access Journals (Sweden)

    Eugenio Picano

    2015-05-01

    Full Text Available A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque, iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque, and markedly hyperechoic with shadowing (calcific plaque. Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging

  15. Integrated analysis of microarray data of atherosclerotic plaques: modulation of the ubiquitin-proteasome system.

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    Full Text Available Atherosclerosis is a typical complex multi-factorial disease and many molecules at different levels and pathways were involved in its development. Some studies have investigated the dysregulation in atherosclerosis at mRNA, miRNA or DNA methylation level, respectively. However, to our knowledge, the studies that integrated these data and revealed the abnormal networks of atherosclerosis have not been reported. Using microarray technology, we analyzed the omics data in atherosclerosis at mRNA, miRNA and DNA methylation levels. Our results demonstrated that the global DNA methylation and expression of miRNA/mRNA were significantly decreased in atherosclerotic plaque than in normal vascular tissue. The interaction network constructed using the integrative data revealed many genes, cellular processes and signaling pathways which were widely considered to play crucial roles in atherosclerosis and also revealed some genes, miRNAs or signaling pathways which have not been investigated in atherosclerosis until now (e.g. miR-519d and SNTB2. Moreover, the overall protein ubiquitination in atherosclerotic plaque was significantly increased. The proteasome activity was increased early but decreased in advanced atherosclerosis. Our study revealed many classic and novel genes and miRNAs involved in atherosclerosis and indicated the effects of ubiquitin-proteasome system on atherosclerosis might be closely related to the course of atherosclerosis. However, the efficacy of proteasome inhibitors in the treatment of atherosclerosis still needs more research.

  16. EFFECTS OF β-ENDORPHIN ON PHYTOHEMAGGLUTININ -INDUCED LYMPHOCYTE PROLIFERATION AND MOUSE PLAQUE-FORMINGCELL RESPONSE VIA AN OPIOID RECEPTOR MECHANISM

    Institute of Scientific and Technical Information of China (English)

    林嘉友; 鲁刚; 翁佳玉

    1994-01-01

    The effects of opioid peptides on immune responses were investigated.It was found that β-endorphin(β-END) can depress proliferative responses to PHA in rat splenocytes but enhance those in mice,and it could also inibit the plaque-forming cell(PFC) response to sheep red blood cells when mouse splenocytes immunized in vivo were cultured in vitro with the peptide.The peptide antagonist naloxone was able to reverse β-END suppression of the PFC response.The data indicate that β-END suppresses antibody production or secretion via a specific opioidreceptor-mediated mechanism.

  17. Characterization and genomic analysis of a plaque purified strain of cyanophage PP.

    Science.gov (United States)

    Zhou, Yiran; Lin, Juan; Li, Na; Hu, Zhihong; Deng, Fei

    2013-10-01

    Cyanophages are ubiquitous and essential components of the aquatic environment and play an important role in the termination of algal blooms. As such, they have attracted widespread interest. PP was the first isolated cyanophage in China, which infects Plectonema boryanum and Phormidium foveolarum. In this study, this cyanophage was purified three times by a double-agar overlay plaque assay and characterized. Its genome was extracted, totally sequenced and analyzed. Electron microscopy revealed a particle with an icosahedral head connected to a short stubby tail. Bioassays showed that PP was quite virulent. The genome of PP is a 42,480 base pair (bp), linear, double-stranded DNA molecule with 222 bp terminal repeats. It has high similarity with the known Pf-WMP3 sequence. It contains 41 open reading frames (ORFs), 17 of which were annotated. Intriguingly, the genome can be divided into two completely different parts, which differ both in orientation and function.

  18. Microbiological analysis of bacterial plaque on three different threads in oral surgery.

    Science.gov (United States)

    Bucci, Marco; Borgonovo, Andrea; Bianchi, Albino; Zanellato, Anna; Re, Dino

    2017-02-01

    Suture is the final act of most oral surgery procedures. The quality of healing after the operation depends on its efficiency. Sutures must not cause inflammation - neither directly nor indirectly. The objective of this study is to compare the bacterial colonization on different suture materials after a third molar extraction. Thirty patients were randomly selected among people going under third molar extraction; they were divided into 3 groups and one suture type was used on each group. After 7 days distal stitches were removed by a single operator, placed in physiologic solution and analyzed after 2 or 3 hours. Patients followed the same postsurgical protocols; materials used were: Ethicon Silk® 4/0, B. Braun Dafilon® 4/0, and B. Braun Safil® 4/0. The amount of cocci and bacilli on the sutures analyzed shows that silk (Ethicon Silk) is the higher level of retention material where monofilament (B. Braun Dafilon) is the lower. There is a difference between monofilament and polyglycolide (B. Braun Safil), as the former is less retentive than the latter, although not significantly so. A less plaque retention, and consequently a fewer bacterial presence, is crucial to minimize the inflammatory process and allow a better tissue healing. Since the capability of brushing and, of course, the final personal hygiene depends on multiple variables, we must use surgical protocols able to minimize the effect of improper cleaning on the healing process: this statement implies the use of low plaque retention materials. The use of monofilament or polyglycolide threads in sutures can help reducing bacterial concentration and therefore promotes a faster and better healing.

  19. Atherosclerotic plaque components characterization and macrophage infiltration identification by intravascular ultrasound elastography based on b-mode analysis: validation in vivo.

    Science.gov (United States)

    Zhang, Peng-Fei; Su, Hai-Jun; Zhang, Mei; Li, Ji-Fu; Liu, Chun-Xi; Ding, Shi-Fang; Miao, Ya; Chen, Liang; Li, Xiao-Nan; Yi, Xin; Zhang, Yun

    2011-01-01

    Intravascular ultrasound elastography (IVUSE) is a promising imaging technique for early investigation of vulnerable plaques. Compared to radiofrequency signal processing, digital B-mode analysis is simple and of higher portability. However, rare studies have been reported validating the latter technique in vivo. In this study, we developed an IVUSE computer software system involving semi-automatic border delineation and block-matching algorithm and validated the system in vivo. Seven minipigs were fed with atherogenic diet for 40 weeks. For each pig, the endothelium of one side of the renal arteries was denuded at the fifth week. With cross-correlation analysis, Lagrangian strain was calculated from two intravascular ultrasound images acquired in situ. Sixty regions of interests were selected from 35 elastograms matched well with the corresponding histological slices. Plaque types within these regions were classified as fibrous, fibro-fatty or fatty on Masson's trichrome and Oil-red O staining. Macrophage infiltration was also evaluated with immunohistology. Comparison between the mean strain value of the region of interest and the histological results revealed significant differences in strain values among different plaque types and non-diseased artery walls. The extent of macrophage infiltration was found to be correlated positively with strain values. For identification of fibro-fatty and fibrous plaques and macrophage infiltration, the system showed high sensitivity (93, 96 and 92%, respectively) and specificity (89, 76 and 66%, respectively), as revealed by receiver operating characteristic analysis. Our IVUSE system based on B-mode analysis is capable of characterizing fibrous and fibro-fatty plaques and macrophage intensity, thus holds potential for identifying vulnerable plaque.

  20. Mechanical stimulation of C2C12 cells increases m-calpain expression, focal adhesion plaque protein degradation and cell differentiation

    DEFF Research Database (Denmark)

    Grossi, Alberto; Lawson, Moira Ann

    Abstract Mechanical stimulation of C2C12 cells increases m-calpain expression, focal adhesion plaque protein degradation and cell differentiation. A. Grossi, M. A. Lawson; Department of Food Science, Royal Veterinary and Agricultural University, Frederiksberg C, Denmark The process of muscle...... development and growth is a complex sequence of events whereby muscle cells respond to a number of stimuli in order to form organised muscle tissue. Increase in muscle mass is greatly influenced by the rate of skeletal muscle protein synthesis and degradation, processes that can be altered by mechanical...... forces. Stretch- or load-induced signaling is now beginning to be understood as a factor which affects the mass and phenotype of muscles as well as the expression of a number of proteins within muscle cells. Use of magnetic field to produce mechanical forces to stimulate cell populations has been well...

  1. Digital Image Analysis of Ultrasound B-mode images of Carotid Atherosclerotic Plaque: Correlation with Histological Examination

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Rosendal, Kim; Grønholdt, Marie-Louise Moes

    1996-01-01

    This paper reports on a study of how well texture features extracted from B-mode images of atherosclerotic plaque correlates with histological results obtained from the same plaque after carotid endarterectomy. The study reveals that a few second order texture features (diagonal moment, standard...

  2. Meta-analysis of genome-wide association studies from the CHARGE consortium identifies common variants associated with carotid intima media thickness and plaque

    NARCIS (Netherlands)

    J.C. Bis (Joshua); M. Kavousi (Maryam); N. Franceschini (Nora); A.J. Isaacs (Aaron); G.R. Abecasis (Gonçalo); U. Schminke (Ulf); W.S. Post (Wendy S.); A.V. Smith (Albert Vernon); L.A. Cupples (Adrienne); H.S. Markus (Hugh S.); R. Schmidt (Reinhold); J.E. Huffman (Jennifer); T. Lehtimäki (Terho); J. Baumert (Jens); T. Münzel (Thomas); S.R. Heckbert (Susan); A. Dehghan (Abbas); K.E. North (Kari); B.A. Oostra (Ben); S. Bevan (Steve); E.M. Stoegerer (Eva Maria); C. Hayward (Caroline); O. Raitakari (Olli); C. Meisinger (Christa); A. Schillert (Arne); S. Sanna (Serena); H. Völzke (Henry); Y.C. Cheng (Yu Ching); B. Thorsson (Bolli); C.S. Fox (Caroline); K. Rice (Kenneth); F. Rivadeneira Ramirez (Fernando); V. Nambi (Vijay); E. Halperin (Eran); K. Petrovic (Katja); L. Peltonen (Leena Johanna); H.E. Wichmann (Heinz Erich); R.B. Schnabel (Renate); M. Dörr (Marcus); A. Parsa (Afshin); T. Aspelund (Thor); S. Demissie (Serkalem); S. Kathiresan (Sekar); M.P. Reilly (Muredach); K.D. Taylor (Kent); A.G. Uitterlinden (André); D.J. Couper (David); M. Sitzer (Matthias); M. Kähönen (Mika); T. Illig (Thomas); P.S. Wild (Philipp); M. Orrù (Marco); J. Lüdemann (Jan); A.R. Shuldiner (Alan); G. Eiriksdottir (Gudny); C.C. White (Charles); J.I. Rotter (Jerome); A. Hofman (Albert); J. Seissler (Jochen); T. Zeller (Tanja); G. Usala; F.D.J. Ernst (Florian); L.J. Launer (Lenore); R.B. D'Agostino (Ralph); D.H. O'Leary (Daniel H.); C. Ballantyne (Christie); J.P. Thiery (Joachim); A. Ziegler (Andreas); E. Lakatta (Edward); R.K. Chilukoti (Ravi Kumar); T.B. Harris (Tamara); P.A. Wolf (Philip); B.M. Psaty (Bruce); J.F. Polak (Joseph F.); X. Li (Xiaohui); W. Rathmann (Wolfgang); M. Uda (Manuela); E.A. Boerwinkle (Eric); N. Klopp (Norman); J.F. Wilson (James); J. Viikari (Jorma); W. Koenig (Wolfgang); S. Blankenberg (Stefan); A.B. Newman (Anne); J.C.M. Witteman (Jacqueline); G. Heiss (Gerardo); C.M. van Duijn (Cock); A. Scuteri (Angelo); G. Homuth (Georg); B.D. Mitchell (Braxton); V. Gudnason (Vilmundur); C.J. O'Donnell (Christopher)

    2011-01-01

    textabstractCarotid intima media thickness (cIMT) and plaque determined by ultrasonography are established measures of subclinical atherosclerosis that each predicts future cardiovascular disease events. We conducted a meta-analysis of genome-wide association data in 31,211 participants of European

  3. Mechanical Stimulation of C2C12 Cells Increases m-Calpain Expression and Activity, Focal Adhesion Plaque Degradation and Cell Fusion

    DEFF Research Database (Denmark)

    Grossi, Alberto; Lawson, Moira Ann; Karlsson, Anders H

    Abstract Mechanical Stimulation of C2C12 Cells Increases m-calpain Expression and Activity, Focal Adhesion Plaque Degradation and Cell Fusion A. Grossi, A. H. Karlsson, M. A. Lawson; Department of Dairy and Food Science, Royal Veterinary and Agricultural University, Frederiksberg C, Denmark...... to the activity of ubiquitous proteolytic enzymes known as calpains has been reported. Whether there is a link between stretch- or load induced signaling and calpain expression and activation is not known. Using a magnetic bead stimulation assay and C2C12 mouse myoblasts cell population, we have demonstrated...... that mechanical stimulation via laminin receptors leads to an increase in m-calpain expression, but no increase in the expression of other calpain isoforms. Our study revealed that after a short period of stimulation, m-calpain relocates into focal adhesion complexes and is followed by a breakdown of specific...

  4. Atherosclerotic plaque regression: fact or fiction?

    Science.gov (United States)

    Shanmugam, Nesan; Román-Rego, Ana; Ong, Peter; Kaski, Juan Carlos

    2010-08-01

    Coronary artery disease is the major cause of death in the western world. The formation and rapid progression of atheromatous plaques can lead to serious cardiovascular events in patients with atherosclerosis. The better understanding, in recent years, of the mechanisms leading to atheromatous plaque growth and disruption and the availability of powerful HMG CoA-reductase inhibitors (statins) has permitted the consideration of plaque regression as a realistic therapeutic goal. This article reviews the existing evidence underpinning current therapeutic strategies aimed at achieving atherosclerotic plaque regression. In this review we also discuss imaging modalities for the assessment of plaque regression, predictors of regression and whether plaque regression is associated with a survival benefit.

  5. Ultrasound analysis of gray-scale median value of carotid plaques is a useful reference index for cerebro-cardiovascular events in patients with type 2 diabetes.

    Science.gov (United States)

    Ariyoshi, Kyoko; Okuya, Shigeru; Kunitsugu, Ichiro; Matsunaga, Kimie; Nagao, Yuko; Nomiyama, Ryuta; Takeda, Komei; Tanizawa, Yukio

    2015-01-01

    Measurements of plaque echogenicity, the gray-scale median (GSM), were shown to correlate inversely with risk factors for cerebro-cardiovascular disease (CVD). The eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio is a potential predictor of CVD risk. In the present study, we assessed the usefulness of carotid plaque GSM values and EPA/AA ratios in atherosclerotic diabetics. A total of 84 type 2 diabetics with carotid artery plaques were enrolled. On admission, platelet aggregation and lipid profiles, including EPA and AA, were examined. Using ultrasound, mean intima media thickness and plaque score were measured in carotid arteries. Plaque echogenicity was evaluated using computer-assisted quantification of GSM. The patients were then further observed for approximately 3 years. Gray-scale median was found to be a good marker of CVD events. On multivariate logistic regression analysis, GSM <32 and plaque score ≥5 were significantly associated with past history and onset of CVD during the follow-up period, the odds ratios being 7.730 (P = 0.014) and 4.601 (P = 0.046), respectively. EPA/AA showed a significant correlation with GSM (P = 0.012) and high-density lipoprotein cholesterol (P = 0.039), and an inverse correlation with platelet aggregation (P = 0.046) and triglyceride (P = 0.020). Although most patients with CVD had both low GSM and low EPA/AA values, an association of EPA/AA with CVD events could not be statistically confirmed. The present results suggest the GSM value to be useful as a reference index for CVD events in high-risk atherosclerotic diabetics. Associations of the EPA/AA ratio with known CVD risk factors warrant a larger and more extensive study to show the usefulness of this parameter.

  6. Tensile and compressive properties of fresh human carotid atherosclerotic plaques.

    LENUS (Irish Health Repository)

    Maher, Eoghan

    2009-12-11

    Accurate characterisation of the mechanical properties of human atherosclerotic plaque is important for our understanding of the role of vascular mechanics in the development and treatment of atherosclerosis. The majority of previous studies investigating the mechanical properties of human plaque are based on tests of plaque tissue removed following autopsy. This study aims to characterise the mechanical behaviour of fresh human carotid plaques removed during endarterectomy and tested within 2h. A total of 50 radial compressive and 17 circumferential tensile uniaxial tests were performed on samples taken from 14 carotid plaques. The clinical classification of each plaque, as determined by duplex ultrasound is also reported. Plaques were classified as calcified, mixed or echolucent. Experimental data indicated that plaques were highly inhomogeneous; with variations seen in the mechanical properties of plaque obtained from individual donors and between donors. The mean behaviour of samples for each classification indicated that calcified plaques had the stiffest response, while echolucent plaques were the least stiff. Results also indicated that there may be a difference in behaviour of samples taken from different anatomical locations (common, internal and external carotid), however the large variability indicates that more testing is needed to reach significant conclusions. This work represents a step towards a better understanding of the in vivo mechanical behaviour of human atherosclerotic plaque.

  7. Mechanical stimulation of C2C12 cells increases m-calpain expression, focal adhesion plaque protein degradation and cell differentiation

    DEFF Research Database (Denmark)

    Grossi, Alberto; Lawson, Moira Ann

    Abstract Mechanical stimulation of C2C12 cells increases m-calpain expression, focal adhesion plaque protein degradation and cell differentiation. A. Grossi, M. A. Lawson; Department of Food Science, Royal Veterinary and Agricultural University, Frederiksberg C, Denmark The process of muscle...... documented and has been shown to affect transcription of specific gene sequences, protein synthesis, the immune system and increase in Ca2+ influx. The past 10 years has seen a dramatic increase in the understanding of how proteolytic enzymes such as calpains can affect the growth of muscle. In vivo studies...... have shown that m-calpain is necessary for myoblast fusion leading to the formation of muscle fibers and that inhibition of this enzyme restricts myotube formation. Whether there is a link between stretchor load induced signaling and m-calpain expression and activation is not known. Using a magnetic...

  8. Advantage in Bright-blood and Black-blood Magnetic Resonance Imaging with High-resolution for Analysis of Carotid Atherosclerotic Plaques

    Directory of Open Access Journals (Sweden)

    Mei Li

    2015-01-01

    Full Text Available Background: About 50% of the cerebral ischemia events are induced by intracranial and extracranial atherosclerosis. This study aimed to evaluate the feasibility and accuracy for displaying atherosclerotic plaques in carotid arteries and analyzing their ingredients by using high-resolution new magnetic resonance imaging (MRI techniques. Methods: Totally, 49 patients suspected of extracranial carotid artery stenosis were subjected to cranial MRI scan and magnetic resonance angiography (MRA examination on carotid arteries, and high-resolution bright-blood and black-blood MRI analysis was carried out within 1 week. Digital subtraction angiography (DSA examination was carried out for 16 patients within 1 month. Results: Totally, 103 plaques were detected in the 49 patients, which were characterized by localized or diffusive thickening of the vessel wall, with the intrusion of crescent-shaped abnormal signal into lumens. Fibrous cap was displayed as isointensity in T1-weighted image (T1WI and hyperintensities in proton density weighted image (PDWI and T2-weighted image (T2WI, lipid core was displayed as isointensity or slight hyperintensities in T1WI, isointensity, hyperintensities or hypointensity in PDWI, and hypointensity in T2WI. Calcification in plaques was detected in 11 patients. Eight patients were detected with irregular plaque surface or ulcerative plaques, which were characterized by irregular intravascular space surface in the black-blood sequences, black hypointensity band was not detected in three-dimensional time-of-flight, or the hypointensity band was not continuous, and intrusion of hyperintensities into plaques can be detected. Bright-blood and black-blood techniques were highly correlated with the diagnosis of contrast-enhanced MRA in angiostenosis degree, Rs = 0.97, P < 0.001. In comparison to DSA, the sensitivity, specificity, and accuracy of MRI diagnosis of stenosis for ≥50% were 88.9%, 100%, and 97.9%, respectively

  9. Development of an improved microneutralization assay for respiratory syncytial virus by automated plaque counting using imaging analysis

    Directory of Open Access Journals (Sweden)

    Quiroz Jorge

    2005-11-01

    Full Text Available Abstract Background Respiratory syncytial virus (RSV is the major cause of lower respiratory tract infection in infants and young children. Although several experimental RSV vaccines are under investigation, immuno therapy is the only treatment currently available. In assessing the immunogenicity of various vaccine formulations, a plaque reduction neutralization assay for the evaluation of RSV neutralizing antibody has been widely used. The method produces reliable results, but it is tedious and labor intensive as it relies on manual counting by laboratory personnel. To facilitate evaluation of phase II and phase III vaccine clinical trials, a more rapid, reliable and efficient neutralization assay is needed. Results An improved microneutralization assay for quantifying RSV neutralizing antibodies was developed using an ImmunoSpot® Series I Analyzer (Cellular Technology Ltd., Cleveland, OH for automated plaque counting. The method is an improvement of the established classical microneutralization assay in which immunostained plaques on transparent tissue culture plates are counted manually under a dissecting microscope. Image analyzer technology allows for fully automated counting of plaques distributed throughout an entire well. Adjustments, such as the use of opaque tissue culture plates and the TMB substrate, True Blue™ (KPL, Gaithersburg, MD, were required to adapt the assay for optimal detection of plaques by the image analyzer. The suitability and the accuracy of the method for counting RSV plaques were determined by comparative testing of a reference serum and two control sera by manual and automated counting methods. The results showed that the two methods were highly correlated (R = 0.9580 and the titers generated by them were within two-fold. Conclusion Our results demonstrate that the semi-automated assay is rapid and reliable. It provides results within two fold to the classical plaque microneutralization assay and is readily

  10. Quantitative analysis of arterial flow properties for detection of non-calcified plaques in ECG-gated coronary CT angiography

    Science.gov (United States)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2015-03-01

    We are developing a computer-aided detection system to assist radiologists in detection of non-calcified plaques (NCPs) in coronary CT angiograms (cCTA). In this study, we performed quantitative analysis of arterial flow properties in each vessel branch and extracted flow information to differentiate the presence and absence of stenosis in a vessel segment. Under rest conditions, blood flow in a single vessel branch was assumed to follow Poiseuille's law. For a uniform pressure distribution, two quantitative flow features, the normalized arterial compliance per unit length (Cu) and the normalized volumetric flow (Q) along the vessel centerline, were calculated based on the parabolic Poiseuille solution. The flow features were evaluated for a two-class classification task to differentiate NCP candidates obtained by prescreening as true NCPs and false positives (FPs) in cCTA. For evaluation, a data set of 83 cCTA scans was retrospectively collected from 83 patient files with IRB approval. A total of 118 NCPs were identified by experienced cardiothoracic radiologists. The correlation between the two flow features was 0.32. The discriminatory ability of the flow features evaluated as the area under the ROC curve (AUC) was 0.65 for Cu and 0.63 for Q in comparison with AUCs of 0.56-0.69 from our previous luminal features. With stepwise LDA feature selection, volumetric flow (Q) was selected in addition to three other luminal features. With FROC analysis, the test results indicated a reduction of the FP rates to 3.14, 1.98, and 1.32 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. The study indicated that quantitative blood flow analysis has the potential to provide useful features for the detection of NCPs in cCTA.

  11. Comparison of triclosan and stannous fluoride dentifrices on parameters of gingival inflammation and plaque scores: a systematic review and meta-analysis.

    Science.gov (United States)

    Sälzer, S; Slot, D E; Dörfer, C E; Van der Weijden, G A

    2015-02-01

    To systematically review the literature to compare the efficacy of triclosan (Tcs) and stannous fluoride (SnF) dentifrices on parameters of gingivitis and plaque scores. Medline, EMBASE and Cochrane Central Register of Controlled Trials were searched up to March 2013 to identify appropriate studies. Studies regarding self-performed manual brushing by adults with a minimum 4 weeks of follow-up were included. Primary outcomes were parameters of gingivitis. Secondary outcome was plaque score. Of 55 publications, 11 met the eligibility criteria. Additionally, four unpublished papers were added after contacting the manufacturers of the leading brands. In total, 15 studies [10 medium term and five long term (>6 months)] were processed for data analysis. There was no difference in gingival index (or its modification) between the two types of dentifrice [DiffM-0.04, 95% confidence interval CI (-0.11; 0.04); P = 0.34]. The change in the average gingival bleeding score was significantly in favour of SnF [DiffM0.02, 95% CI (0.01; 0.02); P < 0.00001]. Plaque scores demonstrated a statistical significant difference in favour of Tcs, according to Quigley-Hein Plaque Index (Q&H PI; DiffM-0.29, 95% CI [-0.45; -0.13]; P = 0.0004), but there was no difference according to Rustogi Modified Navy Plaque Index (RMNPI) [DiffM-0.09, 95% CI (-0.01; 0.18); P = 0.07]. Long-term results supported these findings. In the context of inconclusive results for the primary outcome variable of gingival health, it can be concluded that there was a minor and most likely clinically insignificant difference between Tcs- and SnF-containing dentifrices. Meta-analysis of plaque score reduction was also inconclusive; whereas Tcs was more effective when assessed by the Q&H PI, it was not when scored with the RMNPI. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Fluoride bioavailability in saliva and plaque

    Science.gov (United States)

    2012-01-01

    Background Different fluoride formulations may have different effects on caries prevention. It was the aim of this clinical study to assess the fluoride content, provided by NaF compared to amine fluoride, in saliva and plaque. Methods Eight trained volunteers brushed their teeth in the morning for 3 minutes with either NaF or amine fluoride, and saliva and 3-day-plaque-regrowth was collected at 5 time intervals during 6 hours after tooth brushing. The amount of collected saliva and plaque was measured, and the fluoride content was analysed using a fluoride sensitive electrode. All subjects repeated all study cycles 5 times, and 3 cycles per subject underwent statistical analysis using the Wilcoxon-Mann-Whitney test. Results Immediately after brushing the fluoride concentration in saliva increased rapidly and dropped to the baseline level after 360 minutes. No difference was found between NaF and amine fluoride. All plaque fluoride levels were elevated after 30 minutes until 120 minutes after tooth brushing, and decreasing after 360 minutes to baseline. According to the highly individual profile of fluoride in saliva and plaque, both levels of bioavailability correlated for the first 30 minutes, and the fluoride content of saliva and plaque was back to baseline after 6 hours. Conclusions Fluoride levels in saliva and plaque are interindividually highly variable. However, no significant difference in bioavailability between NaF and amine fluoride, in saliva, or in plaque was found. PMID:22230722

  13. Quantitative analysis of ultrasound B-mode images of carotid atherosclerotic plaque: correlation with visual classification and histological examination

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Grønholdt, Marie-Louise; Wiebe, Brit

    1998-01-01

    a correlation coefficient of r = -0.42 (p = 0.002), for mean echogenicity of the plaque region. The best performing feature was of second order and denoted Contrast (r = -0.5). Though significant, the latter correlation is probably not strong enough to be useful for clinical prediction of relative volume...

  14. Molecular analysis of 16S rRNA genes identifies potentially periodontal pathogenic bacteria and archaea in the plaque of partially erupted third molars.

    Science.gov (United States)

    Mansfield, J M; Campbell, J H; Bhandari, A R; Jesionowski, A M; Vickerman, M M

    2012-07-01

    Small subunit rRNA sequencing and phylogenetic analysis were used to identify cultivable and uncultivable microorganisms present in the dental plaque of symptomatic and asymptomatic partially erupted third molars to determine the prevalence of putative periodontal pathogens in pericoronal sites. Template DNA prepared from subgingival plaque collected from partially erupted symptomatic and asymptomatic mandibular third molars and healthy incisors was used in polymerase chain reaction with broad-range oligonucleotide primers to amplify 16S rRNA bacterial and archaeal genes. Amplicons were cloned, sequenced, and compared with known nucleotide sequences in online databases to identify the microorganisms present. Two thousand three hundred two clones from the plaque of 12 patients carried bacterial sequences from 63 genera belonging to 11 phyla, including members of the uncultivable TM7, SR1, and Chloroflexi, and difficult-to-cultivate Synergistetes and Spirochaetes. Dialister invisus, Filifactor alocis, Fusobacterium nucleatum, Porphyromonas endodontalis, Prevotella denticola, Tannerella forsythia, and Treponema denticola, which have been associated with periodontal disease, were found in significantly greater abundance in pericoronal compared with incisor sites. Dialister invisus and F nucleatum were found in greater abundance in sites exhibiting clinical symptoms. The archaeal species, Methanobrevibacter oralis, which has been associated with severe periodontitis, was found in 3 symptomatic patients. These findings have provided new insights into the complex microbiota of pericoronitis. Several bacterial and archaeal species implicated in periodontal disease were recovered in greater incidence and abundance from the plaque of partially erupted third molars compared with incisors, supporting the hypothesis that the pericoronal region may provide a favored niche for periodontal pathogens in otherwise healthy mouths. Copyright © 2012 American Association of Oral and

  15. Dental plaque identification at home

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003426.htm Dental plaque identification at home To use the sharing ... that collects around and between teeth. The home dental plaque identification test shows where plaque builds up. ...

  16. A tale of two plaques: convergent mechanisms of T-cell-mediated inflammation in psoriasis and atherosclerosis.

    Science.gov (United States)

    Armstrong, April W; Voyles, Stephanie V; Armstrong, Ehrin J; Fuller, Erin N; Rutledge, John C

    2011-07-01

    Psoriasis and atherosclerosis are diseases in which effector T lymphocytes such as Helper T cells type 1 (Th1) and 17 (Th17) play integral roles in disease pathogenesis and progression. Regulatory T cells (Treg) also exert clinically important anti-inflammatory effects that are pathologically altered in psoriasis and atherosclerosis. We review the immunological pathways involving Th1, Th17 and Treg cells that are common to psoriasis and atherosclerosis. These shared pathways provide the basis for mechanisms that may explain the epidemiologic observation that patients with psoriasis have an increased risk of heart disease. Improved understanding of these pathways will guide future experiments and may lead to the development of therapeutics that prevent or treat cardiovascular complications in patients with psoriasis.

  17. Mechanical stimulation of C2C12 cells increases m-calpain expression, focal adhesion plaque protein degradation

    DEFF Research Database (Denmark)

    Grossi, Alberto; Karlsson, Anders H; Lawson, Moira Ann

    2008-01-01

    reorganization due to the activity of the ubiquitous proteolytic enzymes, calpains, has been reported. Whether there is a link between stretch- or load-induced signaling and calpain expression and activation is not known. Using a magnetic bead stimulation assay and C2C12 mouse myoblasts cell population, we have...... demonstrated that mechanical stimulation via laminin receptors leads to an increase in m-calpain expression, but no increase in the expression of other calpain isoforms. Our study revealed that after a short period of stimulation, m-calpain relocates into focal adhesion complexes and is followed by a breakdown...... of specific focal adhesion proteins previously identified as substrates for this enzyme. We show that stimulation also leads to an increase in calpain activity in these cells. These data support the pivotal role for m-calpain in the control of muscle precursor cell differentiation and thus strengthen the idea...

  18. Quantitative Analysis of Dental Plaque Based on Auto-fluorescence Imaging%基于自体荧光成像的牙菌斑量化分析

    Institute of Scientific and Technical Information of China (English)

    鞠国浩; 陈庆光; 朱海华; 林斌; 陈晖

    2014-01-01

    Based on the differences between auto-fluorescence spectra of plaque and dental tissue, a quantitative analysis method of plaque using auto-fluorescence imaging was presented. Auto-fluorescence spectrum of tooth samples excited by 405 nm was measured, on the basis of analyzing the correlation between color parameters of fluorescence and dental plaque content, R/B of fluorescence image was proposed as quantitative assessment parameter of dental plaque content, meanwhile long-wavelength pass filter with central wavelength of 490 nm was used to filter fluorescence spectral bands. Finally, experimental setup was built to obtain the auto-fluorescence image. Quantitative analysis results of three different levels of plaque content and distribution was obtained by using R/B value as segmentation thresholds, which confirmed with visual examination results.%本文基于牙菌斑与牙齿组织自体荧光光谱的差异性,提出了一种利用自体荧光成像的牙菌斑量化分析方法。首先测试了牙齿样品在405 nm 激发光作用下自体荧光光谱分布,在分析荧光颜色参量与牙菌斑含量相关性的基础上,提出以荧光图像的R/B作为牙菌斑含量量化的参量,并确定使用中心波长为490 nm的长波通滤光片对荧光光谱波段进行选择性提取。最后,搭建实验装置获取了牙齿自体荧光图像,利用R/B值作为分割阈值得到了三个不同等级的牙菌斑含量与分布的量化分析结果,与视诊结果相符。

  19. Analysis driven mechanical redesign

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.L.; Robison, R.H.

    1997-08-01

    This paper documents an effort to use a constrained nonlinear optimization package (OptdesX) to drive a feature-based mechanical design system (Pro/Engineer) in an optimization loop. Optimizations performed in this manner can maximally respect the design intent built into the model, and eliminate the need to propagate optimization results back to design, a flaw of most current optimization systems. A prototype system was built to demonstrate the capability; use of the prototype uncovered a variety of issues that should be addressed to productionize this kind of capability.

  20. Carotid plaque age is a feature of plaque stability inversely related to levels of plasma insulin.

    Directory of Open Access Journals (Sweden)

    Sara Hägg

    Full Text Available BACKGROUND: The stability of atherosclerotic plaques determines the risk for rupture, which may lead to thrombus formation and potentially severe clinical complications such as myocardial infarction and stroke. Although the rate of plaque formation may be important for plaque stability, this process is not well understood. We took advantage of the atmospheric (14C-declination curve (a result of the atomic bomb tests in the 1950s and 1960s to determine the average biological age of carotid plaques. METHODOLOGY/PRINCIPAL FINDING: The cores of carotid plaques were dissected from 29 well-characterized, symptomatic patients with carotid stenosis and analyzed for (14C content by accelerator mass spectrometry. The average plaque age (i.e. formation time was 9.6±3.3 years. All but two plaques had formed within 5-15 years before surgery. Plaque age was not associated with the chronological ages of the patients but was inversely related to plasma insulin levels (p = 0.0014. Most plaques were echo-lucent rather than echo-rich (2.24±0.97, range 1-5. However, plaques in the lowest tercile of plaque age (most recently formed were characterized by further instability with a higher content of lipids and macrophages (67.8±12.4 vs. 50.4±6.2, p = 0.00005; 57.6±26.1 vs. 39.8±25.7, p<0.0005, respectively, less collagen (45.3±6.1 vs. 51.1±9.8, p<0.05, and fewer smooth muscle cells (130±31 vs. 141±21, p<0.05 than plaques in the highest tercile. Microarray analysis of plaques in the lowest tercile also showed increased activity of genes involved in immune responses and oxidative phosphorylation. CONCLUSIONS/SIGNIFICANCE: Our results show, for the first time, that plaque age, as judge by relative incorporation of (14C, can improve our understanding of carotid plaque stability and therefore risk for clinical complications. Our results also suggest that levels of plasma insulin might be involved in determining carotid plaque age.

  1. Computerized detection of noncalcified plaques in coronary CT angiography: Evaluation of topological soft gradient prescreening method and luminal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Jun, E-mail: jvwei@umich.edu; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-08-15

    Purpose: The buildup of noncalcified plaques (NCPs) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. Interpretation of coronary CT angiography (cCTA) to search for NCP is a challenging task for radiologists due to the low CT number of NCP, the large number of coronary arteries, and multiple phase CT acquisition. The authors conducted a preliminary study to develop machine learning method for automated detection of NCPs in cCTA. Methods: With IRB approval, a data set of 83 ECG-gated contrast enhanced cCTA scans with 120 NCPs was collected retrospectively from patient files. A multiscale coronary artery response and rolling balloon region growing (MSCAR-RBG) method was applied to each cCTA volume to extract the coronary arterial trees. Each extracted vessel was reformatted to a straightened volume composed of cCTA slices perpendicular to the vessel centerline. A topological soft-gradient (TSG) detection method was developed to prescreen for NCP candidates by analyzing the 2D topological features of the radial gradient field surface along the vessel wall. The NCP candidates were then characterized by a luminal analysis that used 3D geometric features to quantify the shape information and gray-level features to evaluate the density of the NCP candidates. With machine learning techniques, useful features were identified and combined into an NCP score to differentiate true NCPs from false positives (FPs). To evaluate the effectiveness of the image analysis methods, the authors performed tenfold cross-validation with the available data set. Receiver operating characteristic (ROC) analysis was used to assess the classification performance of individual features and the NCP score. The overall detection performance was estimated by free response ROC (FROC) analysis. Results: With our TSG prescreening method, a prescreening sensitivity of 92.5% (111/120) was achieved with a total of 1181 FPs (14.2 FPs/scan). On average, six features

  2. Bacterial colonization during de novo plaque formation.

    Science.gov (United States)

    Ramberg, Per; Sekino, Satoshi; Uzel, Naciye Guzin; Socransky, Sigmund; Lindhe, Jan

    2003-11-01

    To determine microbial changes that occur during plaque formation in a dentition free of gingival inflammation. Ten subjects were recruited. The study included one preparatory period (2 weeks) and a plaque accumulation period (4 days). The volunteers exercised proper tooth cleaning methods, were scaled and received repeated professional mechanical tooth cleaning during the preparatory period. During the plaque accumulation period, the participants abstained from plaque control measures. Plaque was scored on the approximal surfaces of maxillary and mandibular premolars on Days 0, 1, 2 and 4 using a scale from 0 to 5 and according to the criteria of the Quigley and Hein Plaque Index (QHI). Supragingival plaque samples were obtained from the same intervals and surfaces and evaluated using a checkerboard DNA-DNA hybridization technique. The mean QHI increased from 0 to 1.6 (Day 4). The total number of organisms on Day 0 averaged 140 x 10(5) and increased to about 210 x 10(5) after 4 days without oral hygiene. The most dominant species on Day 0 were members of the genus Actinomyces. These organisms comprised almost 50% of the microbiota evaluated. None of the Actinomyces species increased significantly during the 4 days. Some Streptococcus species increased significantly over time as well as species of the genera Capnocytophaga, Campylobacter, Fusobacteria and Actinomyces actinomycetemcomitans. In the present investigation, the preparatory phase established a situation with minimal gingival inflammation and close to zero amounts of dental plaque. The Day 0 plaque samples exhibited high proportions of Actinomyces species. During the 4 days of no oral hygiene, there was a small increase in total numbers of organisms as well as a modest increase in the proportion of "disease-associated" taxa such as species of the "orange complex" species.

  3. Apopotic gene Bax expression in carotid plaque

    Institute of Scientific and Technical Information of China (English)

    Bao-Zhong MEN; Ding-Biao ZHOU; Huai-Yin SHI; Xiao-Ming ZHANG

    2006-01-01

    The expression of BAX in carotid atherosclerosis and its regulation is far from defined. Objectives To investigate BAX expression in stable/fibrous and instable/vulnerable carotid plaque and its clinical significance. Methods 25 cases of carotid plaque specimens obtained from endarterectomy were divided into two groups, stable/fibrous 14 cases, vulnerable/instable 11 cases; aortic artery and its branches from hepatic transplantation donors 6 case as control. The expression of proapoptotic BAX was detected by immunohistochemistry(IHC), in situ hybridization(ISH) and in situ TdT dUTP nick end labeling (TUNEL). Results 5 cases of BAX ( + ) were detected by ICH and ISH, 4 case of TUNEL ( + ) were detected by TUNEL in stable/fibrous carotid plaque , while 10 cases were BAX ( + )by IHC(P < 0.05) , 11case by ISH and 9 case by TUNEL were detected in instable/vulnerable carotid plaque ( P < 0.01 ), respectively. The intensity of BAX ( + ) cells by IHC and ISH was 8.63 ± 2.62 and 10.32 ± 3.12 in fibrous plaques, whereas 122 ± 21.64and 152 ± 23.35 in vulnerable plaques, respectively. No expression of BAX was found in controlled group. Conclusion The higher expression of Bax in vulnerable carotid plaque may be one mechanisms in molecular pathogenesis of carotid atherosclerosis which affect plaque stability and be the cause of higher incidence of stroke than fibrous carotid plaques, the regulation of BAX expression in different stage of atherosclerosis may provide targets in gene therapy for carotid atherosclerosis.

  4. The desmosomal plaque and the cytoskeleton.

    Science.gov (United States)

    Franke, W W; Cowin, P; Schmelz, M; Kapprell, H P

    1987-01-01

    Two major plasma membrane domains are involved in the architectural organization of the cytoskeleton. Both are junctions of the adherens category characterized by the presence of dense plaques associated with the cytoplasmic surface of their membranes. The plaques serve as specific anchorage structures for two different types of cytoplasmic filaments. Intermediate-sized filaments (IF) of several types, i.e. cytokeratin IF in epithelial cells, desmin IF in cardiac myocytes and vimentin IF in arachnoidal cells of meninges, meningiomas and several other cells, attach to the desmosomal plaques, whereas actin-containing microfilaments associate with non-desmosomal adhering junctions such as the zonula adherens, fascia adherens and punctum adherens. The plaques of both kinds of adhering junctions contain a common acidic polypeptide of Mr 83,000 identical to 'band 5 protein' of bovine snout epidermal desmosomes. However, other plaque components are mutually exclusive to one of the two subclasses of adhering junctions. The desmosomal plaque structure, which does not contain vinculin and alpha-actinin, comprises representatives of cytoplasmic, non-membrane-integrated proteins such as desmoplakin(s) and the cytoplasmic portions of transmembrane glycoproteins such as 'band 3 glycoprotein'. The analysis of both categories of junction-associated plaques should provide a basis for understanding the establishment and the dynamics of junction-cytoskeleton interaction.

  5. Corneal mucus plaques.

    Science.gov (United States)

    Fraunfelder, F T; Wright, P; Tripathi, R C

    1977-02-01

    Corneal mucus plaques adhered to the anterior corneal surface in 17 of 67 advanced cases of keratoconjunctivitis sicca. The plaques were translucent to opaque and varied in size and shape, from multiple isolated islands to bizarre patterns involving more than half the corneal surface. Ultrastructurally, they consisted of mucus mixed with desquamated degenerating epithelial cells and proteinaceous and lipoidal material. The condition may be symptomatic but can be controlled and prevented in most cases by topical ocular application of 10% acetylcysteine.

  6. An analysis of concentration of sucrose, endogenous pH, and alteration in the plaque pH on consumption of commonly used liquid pediatric medicines

    Directory of Open Access Journals (Sweden)

    Sunitha S

    2009-03-01

    Full Text Available Background: Many parents are often unaware of the hidden, added sugars in many foods and drinks including pediatric liquid medicines; thus, hidden sugar in the form of pediatric medications has not been focused upon as cariogenic agents. Objective: (i assess concentration of sucrose in six pediatric drugs, (ii determine endogenous pH of these drugs, and (iii estimate drop in the plaque pH in the oral cavity in first 30 minutes after consumption of the drugs. Materials and Methods: Ten adult volunteers with mean age of 22 years were double blinded for the study. Concentration of sucrose was assessed by volumetric method at Department of Chemical Branch of Engineering. Endogenous pH and drop in the plaque pH after consumption of the drugs were assessed using digital pH meter. Statistical analysis: SPSS software was used to assess the pH level at different time intervals and expressed as mean ± SD. Changes in pH were assessed by one-way ANOVA followed by Wilcoxons signed rank test. P-value was set at 0.05. Result: There were varying amounts of fermentable sucrose detected in the drugs; all the drugs were acidic. There is a significant drop of plaque pH after consumption of the drug. Conclusion: These sweeteners along with their low endogenic pH form a high cariogenic formulation. Thus, nonsucrose (noncariogenic or sugar-free medications are needed to be prescribed along with proper oral hygiene care to the children under medication.

  7. Expression of RANTES mRNA in skin lesions of feline eosinophilic plaque.

    Science.gov (United States)

    Kimura, Tomoe; Kano, Rui; Maeda, Sadatoshi; Tsujimoto, Hajime; Nagata, Masahiko; Hasegawa, Atsuhiko

    2003-10-01

    One of the mechanisms of eosinophil infiltration is its induction by chemoattractants such as regulated upon activation, normal T-expressed and secreted (RANTES) which is a cysteine-cysteine chemokine that mediates chemotaxis and activation of eosinophils in humans and mice. Skin lesions of feline eosinophilic plaque are characterized by a predominant infiltration of eosinophils. The mechanism(s) of eosinophilic infiltration in the skin and/or mucosa of cats is unknown. It is possible that RANTES is involved. To investigate the presence of RANTES in the skin of cats with eosinophilic plaques and nonaffected skin, we cloned and sequenced the full-length feline RANTES cDNA gene, in order to determine whether it is present in the skin of cats with eosinophilic plaques and/or if it is present in normal adjacent skin. We were able to document the the expression of RANTES mRNAs in skin with feline eosinophilic plaque as well as in normal cat skin. The full-length cDNA sequence of the RANTES gene (742 bp) contained a single open reading frame of 276 bp encoding a protein of 92 amino acids. The amino acid sequence of feline RANTES shared 67 and 74% sequence identity with that of bovine and mouse RANTES genes, respectively. RT-PCR analysis on RANTES mRNA in the skin of cats with eosinophilic plaque revealed that its expression was higher in the eosinophilic plaque skin lesions than in the normal skin. The result suggested that RANTES might play a role to induce eosinophil infiltration in feline eosinophilic plaque lesions.

  8. [Is regression of atherosclerotic plaque possible?

    Science.gov (United States)

    Páramo, José A; Civeira, Fernando

    As it is well-known, a thrombus evolving into a disrupted/eroded atherosclerotic plaque causes most acute coronary syndromes. Plaque stabilization via reduction of the lipid core and/or thickening of the fibrous cap is one of the possible mechanisms accounted for the clinical benefits displayed by different anti-atherosclerotic strategies. The concept of plaque stabilization was developed to explain how lipid-lowering agents could decrease adverse coronary events without substantial modifications of the atherosclerotic lesion ('angiographic paradox'). A number of imaging modalities (vascular ultrasound and virtual histology, MRI, optical coherence tomography, positron tomography, etc.) are used for non-invasive assessment of atherosclerosis; most of them can identify plaque volume and composition beyond lumen stenosis. An 'aggressive' lipid-lowering strategy is able to reduce the plaque burden and the incidence of cardiovascular events; this may be attributable, at least in part, to plaque-stabilizing effects. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Analysis of kinetic reaction mechanisms

    CERN Document Server

    Turányi, Tamás

    2014-01-01

    Chemical processes in many fields of science and technology, including combustion, atmospheric chemistry, environmental modelling, process engineering, and systems biology, can be described by detailed reaction mechanisms consisting of numerous reaction steps. This book describes methods for the analysis of reaction mechanisms that are applicable in all these fields. Topics addressed include: how sensitivity and uncertainty analyses allow the calculation of the overall uncertainty of simulation results and the identification of the most important input parameters, the ways in which mechanisms can be reduced without losing important kinetic and dynamic detail, and the application of reduced models for more accurate engineering optimizations. This monograph is invaluable for researchers and engineers dealing with detailed reaction mechanisms, but is also useful for graduate students of related courses in chemistry, mechanical engineering, energy and environmental science and biology.

  10. Morphological and Stress Vulnerability Indices for Human Coronary Plaques and Their Correlations with Cap Thickness and Lipid Percent: An IVUS-Based Fluid-Structure Interaction Multi-patient Study.

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2015-12-01

    Full Text Available Plaque vulnerability, defined as the likelihood that a plaque would rupture, is difficult to quantify due to lack of in vivo plaque rupture data. Morphological and stress-based plaque vulnerability indices were introduced as alternatives to obtain quantitative vulnerability assessment. Correlations between these indices and key plaque features were investigated. In vivo intravascular ultrasound (IVUS data were acquired from 14 patients and IVUS-based 3D fluid-structure interaction (FSI coronary plaque models with cyclic bending were constructed to obtain plaque wall stress/strain and flow shear stress for analysis. For the 617 slices from the 14 patients, lipid percentage, min cap thickness, critical plaque wall stress (CPWS, strain (CPWSn and flow shear stress (CFSS were recorded, and cap index, lipid index and morphological index were assigned to each slice using methods consistent with American Heart Association (AHA plaque classification schemes. A stress index was introduced based on CPWS. Linear Mixed-Effects (LME models were used to analyze the correlations between the mechanical and morphological indices and key morphological factors associated with plaque rupture. Our results indicated that for all 617 slices, CPWS correlated with min cap thickness, cap index, morphological index with r = -0.6414, 0.7852, and 0.7411 respectively (p<0.0001. The correlation between CPWS and lipid percentage, lipid index were weaker (r = 0.2445, r = 0.2338, p<0.0001. Stress index correlated with cap index, lipid index, morphological index positively with r = 0.8185, 0.3067, and 0.7715, respectively, all with p<0.0001. For all 617 slices, the stress index has 66.77% agreement with morphological index. Morphological and stress indices may serve as quantitative plaque vulnerability assessment supported by their strong correlations with morphological features associated with plaque rupture. Differences between the two indices may lead to better plaque

  11. Plaque Type Blue Naevus

    Directory of Open Access Journals (Sweden)

    Sentamilselvi G

    1997-01-01

    Full Text Available A case of plaque type blue naevus was encountered in a Dermatology Clinic in Madras. The various clinical differential diagnoses are discussed, the hitopathological features described and the benign nature of the tumour stressed. The case is reported for its rarity and to create an awareness of this entity.

  12. Functional expression of dental plaque microbiota.

    Science.gov (United States)

    Peterson, Scott N; Meissner, Tobias; Su, Andrew I; Snesrud, Erik; Ong, Ana C; Schork, Nicholas J; Bretz, Walter A

    2014-01-01

    Dental caries remains a significant public health problem and is considered pandemic worldwide. The prediction of dental caries based on profiling of microbial species involved in disease and equally important, the identification of species conferring dental health has proven more difficult than anticipated due to high interpersonal and geographical variability of dental plaque microbiota. We have used RNA-Seq to perform global gene expression analysis of dental plaque microbiota derived from 19 twin pairs that were either concordant (caries-active or caries-free) or discordant for dental caries. The transcription profiling allowed us to define a functional core microbiota consisting of nearly 60 species. Similarities in gene expression patterns allowed a preliminary assessment of the relative contribution of human genetics, environmental factors and caries phenotype on the microbiota's transcriptome. Correlation analysis of transcription allowed the identification of numerous functional networks, suggesting that inter-personal environmental variables may co-select for groups of genera and species. Analysis of functional role categories allowed the identification of dominant functions expressed by dental plaque biofilm communities, that highlight the biochemical priorities of dental plaque microbes to metabolize diverse sugars and cope with the acid and oxidative stress resulting from sugar fermentation. The wealth of data generated by deep sequencing of expressed transcripts enables a greatly expanded perspective concerning the functional expression of dental plaque microbiota.

  13. Functional Expression of Dental Plaque Microbiota

    Directory of Open Access Journals (Sweden)

    Scott Norman Peterson

    2014-08-01

    Full Text Available Dental caries remains a significant public health problem and is considered pandemic worldwide. The prediction of dental caries based on profiling of microbial species involved in disease and equally important, the identification of species conferring dental health has proven more difficult than anticipated due to high interpersonal and geographical variability of dental plaque microbiota. We have used RNA-Seq to perform global gene expression analysis of dental plaque microbiota derived from 19 twin pairs that were either concordant (caries-active or caries-free or discordant for dental caries. The transcription profiling allowed us to define a functional core microbiota consisting of nearly 60 species. Similarities in gene expression patterns allowed a preliminary assessment of the relative contribution of human genetics, environmental factors and caries phenotype on the microbiota’s transcriptome. Correlation analysis of transcription allowed the identification of numerous functional networks, suggesting that inter-personal environmental variables may co-select for groups of genera and species. Analysis of functional role categories allowed the identification of dominant functions expressed by dental plaque biofilm communities, that highlight the biochemical priorities of dental plaque microbes to metabolize diverse sugars and cope with the acid and oxidative stress resulting from sugar fermentation. The wealth of data generated by deep sequencing of expressed transcripts enables a greatly expanded perspective concerning the functional expression of dental plaque microbiota.

  14. Mechanical tolerance stackup and analysis

    CERN Document Server

    Fischer, Bryan R

    2011-01-01

    Use Tolerance Analysis Techniques to Avoid Design, Quality, and Manufacturing Problems Before They Happen Often overlooked and misunderstood, tolerance analysis is a critical part of improving products and their design processes. Because all manufactured products are subject to variation, it is crucial that designers predict and understand how these changes can affect form, fit, and function of parts and assemblies--and then communicate their findings effectively. Written by one of the developers of ASME Y14.5 and other geometric dimension and tolerancing (GD&T) standards, Mechanical Tolerance

  15. Characteristics of carotid atherosclerotic plaques of chronic lipid apheresis patients as assessed by In Vivo High-Resolution CMR - a comparative analysis

    Directory of Open Access Journals (Sweden)

    Grimm Jochen M

    2012-11-01

    Full Text Available Abstract Background Components of carotid atherosclerotic plaques can reliably be identified and quantified using high resolution in vivo 3-Tesla CMR. It is suspected that lipid apheresis therapy in addition to lowering serum lipid levels also has an influence on development and progression of atherosclerotic plaques. The purpose of this study was to evaluate the influence of chronic lipid apheresis (LA on the composition of atherosclerotic carotid plaques. Methods 32 arteries of 16 patients during chronic LA-therapy with carotid plaques and stenosis of 1–80% were matched according to degree of stenosis with 32 patients, who had recently suffered an ischemic stroke. Of these patients only the asymptomatic carotid artery was analyzed. All patients underwent black-blood 3 T CMR of the carotids using parallel imaging and dedicated surface coils. Cardiovascular risk factors were recorded. Morphology and composition of carotid plaques were evaluated. For statistical evaluation Fisher’s Exact and unpaired t-test were used. A p-value Results Patients in the LA-group were younger (63.5 vs. 73.9. years, p2, p Conclusion Results of this study suggest that, despite a severer risk profile for cardiovascular complications in LA-patients, chronic LA is associated with significantly lower lipid content in carotid plaques compared to plaques of patients without LA with similar degrees of stenosis, which is characteristic of clinically stable plaques.

  16. Plaque complement activation and cognitive loss in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Camp Dianne M

    2008-03-01

    Full Text Available Abstract Background Complement activation is increased in Alzheimer's disease (AD, but its significance is unclear. The objective of this study was to determine the relationship between complement activation and cognition during the development of AD. Methods iC3b, C9, Bielschowsky, and Gallyas staining was performed on aged normal (n = 17, mild cognitively impaired (n = 12, and AD (n = 17–18 inferior temporal gyrus specimens. Plaques were counted in 10× fields with high numbers of Bielschowsky-stained plaques. One-way ANOVA was used to determine between-group differences for plaque counts and measures of cognitive function, and linear regression was used to evaluate global cognition as a function of Bielschowsky-stained plaques. Terms for iC3b- and C9-stained plaques were then added sequentially as additional predictors in a "mediation analysis" model. Results Complement was detected on plaques in all groups, and on neurofibrillary tangles only in AD specimens. iC3b, C9, and Bielschowsky-stained plaque counts increased 2.5- to 3-fold in AD vs. other groups (all p ≤ 0.01. C9 staining was present on some diffuse plaques, as well as on neuritic plaques. Bielschowsky-stained and complement-stained plaque counts were highly correlated, and were negatively correlated with cognitive measures. When the Bielschowsky plaque count was used as a predictor, its correlations with cognitive measures were statistically significant, but when iC3b and C9 plaque counts were added as additional predictors, these correlations were no longer significant. This loss of significance was attributed to multicollinearity, i.e., high correlations between Bielschowsky-stained and complement-stained plaque counts. Conclusion Both early-stage (iC3b and late-stage (C9 complement activation occurs on neocortical plaques in subjects across the cognitive spectrum; contrary to previous reports, C9 is present on some diffuse plaques. Because of high correlations between

  17. Uveal Melanoma Treated With Iodine-125 Episcleral Plaque: An Analysis of Dose on Disease Control and Visual Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Bradford A. [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Mettu, Pradeep; Vajzovic, Lejla [Department of Ophthalmology, Duke University, Durham, North Carolina (United States); Rivera, Douglas [Austin Cancer Centers, Austin, Texas (United States); Alkaissi, Ali; Steffey, Beverly A.; Cai, Jing [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Stinnett, Sandra [Department of Biostatistics and Informatics, Duke University, Durham, North Carolina (United States); Dutton, Jonathan J. [Department of Ophthalmology, University of North Carolina, Chapel Hill, North Carolina (United States); Buckley, Edward G. [Department of Ophthalmology, Duke University, Durham, North Carolina (United States); Halperin, Edward [Department of Radiation Oncology, New York Medical College, Valhalla, New York (United States); Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Mruthyunjaya, Prithvi [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Department of Ophthalmology, Duke University, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina (United States)

    2014-05-01

    Purpose: To investigate, in the treatment of uveal melanomas, how tumor control, radiation toxicity, and visual outcomes are affected by the radiation dose at the tumor apex. Methods and Materials: A retrospective review was performed to evaluate patients treated for uveal melanoma with {sup 125}I plaques between 1988 and 2010. Radiation dose is reported as dose to tumor apex and dose to 5 mm. Primary endpoints included time to local failure, distant failure, and death. Secondary endpoints included eye preservation, visual acuity, and radiation-related complications. Univariate and multivariate analyses were performed to determine associations between radiation dose and the endpoint variables. Results: One hundred ninety patients with sufficient data to evaluate the endpoints were included. The 5-year local control rate was 91%. The 5-year distant metastases rate was 10%. The 5-year overall survival rate was 84%. There were no differences in outcome (local control, distant metastases, overall survival) when dose was stratified by apex dose quartile (<69 Gy, 69-81 Gy, 81-89 Gy, >89 Gy). However, increasing apex dose and dose to 5-mm depth were correlated with greater visual acuity loss (P=.02, P=.0006), worse final visual acuity (P=.02, P<.0001), and radiation complications (P<.0001, P=.0009). In addition, enucleation rates were worse with increasing quartiles of dose to 5 mm (P=.0001). Conclusions: Doses at least as low as 69 Gy prescribed to the tumor apex achieve rates of local control, distant metastasis–free survival, and overall survival that are similar to radiation doses of 85 Gy to the tumor apex, but with improved visual outcomes.

  18. Relationship between caries and dental plaque composition.

    Science.gov (United States)

    Bayrak, Sule; Okte, Zeynep; Fidanci, Ulvi Reha

    2011-02-01

    To evaluate the relationship between dental caries and the biochemical composition of dental plaque and to determine the effect of a 10% sucrose solution on the biochemical structure of dental plaque in children. 60 children grouped according to caries status took part in this study [Caries-free (CF), DMFS=0, df-s = 0; Caries-positive (CP), DMFS > or =10, df-s > or =10]. Dental plaque samples were collected before (baseline) and at 3 and 30 minutes after a 1-minute rinse with 10% sucrose. Fluoride (F), calcium (Ca), and inorganic phosphorus (Pi) levels were determined using ion chromatography, and insoluble polysaccharide (IEPS) concentrations were determined using colorimetric analysis. Although the mean baseline Ca and Pi levels in plaque were higher in the CF group than in the CP group, these differences were not statistically significant. Baseline IEPS levels were significantly higher in the CP group than in the CF group. Following exposure to sucrose, plaque F, Ca and Pi concentrations decreased significantly in both groups. However, insoluble polysaccharide concentrations increased significantly in the CF group only.

  19. 孤立性颈动脉粥样硬化斑块内膜长轴切面力学状态的初步超声研究%Preliminary longitudinal mechanical pattern study of the isolated carotid atherosclerotic plaque intima using velocity vector imaging

    Institute of Scientific and Technical Information of China (English)

    岳文胜; 尹立雪; 王珊; 邓燕; 左明良; 李爽; 余洋; 罗安果

    2008-01-01

    Objective To evaluate the mechanical homogeneity pattern of isolated carotid atherosclerotic plaque intima on longitudinal axis view using ultrasonic velocity vector imaging.Methods Fourty six patients with 48 isolated plaques were undergone the high frequency ultrasound scanning,the real-time two-dimensional longitudinal-axis gray scale view at the maximal thickness of the plaque was obtained in three complete cardiac cycles.A dedicated velocity vector imaging(ⅤⅤⅠ)workstation was used for the off-line dynamic two-dimensional gray-scale image analysis and mechanics parameter(i.e.,the peak strain and the absolute difference of the peak strain)assessment at the sites of the upper,middle and down stream separately.The length and direction distribution of the velocity vectors at the carotid atherosclerotic plaque intima were observed.Wilcoxon test was utilized for the comparison of the peak strain and the absolute difference of the peak strain between two sites.Results The chaos phenomenon of velocity vector distribution at the sites of plaque intima occurred significantly differed from those uniform velocity vectors at the reference sites.According to the two groups of the higher strain value side and the lower strain value side on the upper stream and the down stream of the plaque intima,the peak strain at the higher strain value side was significantly higher than the lower strain value side(P=0.000).There was a significantly difference between the absolute difference of peak strain from the higher strain value side to the middle stream point of the plaque intima and the absolute difference of peak strain from the lower strain value side to the higher strain value side of the plaque intima(P<0.017).Conclusions The length and direction distribution of velocity vectors of the isolated carotid atherosclerotic plaque intima on longitudinal axis view are uneven,the mechanical heterogeneity pattern exists at the plaque intima and could be visualized and

  20. Short-term consumption of probiotic lactobacilli has no effect on acid production of supragingival plaque

    DEFF Research Database (Denmark)

    Marttinen, Aino; Haukioja, Anna; Karjalainen, Sára

    2011-01-01

    of probiotics to the plaque was assessed using PCR techniques. No probiotic-induced changes were found in the acidogenicity of plaque. Also, MS counts remained at the original level. The number of subjects with lactobacilli in plaque increased in the L. reuteri group (p¿=¿0.011) but not in the LGG group. PCR...... analysis of plaque revealed the presence of LGG in four and L. reuteri in six subjects after the use of the probiotic. The use of the lactobacilli did not affect the acidogenicity or MS levels of plaque. Short-term consumption of LGG and L. reuteri appeared not to influence the acidogenicity of plaque....

  1. La pelade par plaques

    Science.gov (United States)

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre les schémas thérapeutiques et les résultats des traitements pour la pelade par plaques, de même que les aider à identifier les patients pour qui une demande de consultation en dermatologie pourrait s’imposer. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant le traitement de la pelade par plaques. Message principal La pelade par plaques est une forme auto-immune de perte pileuse qui touche à la fois les enfants et les adultes. Même s’il n’y a pas de mortalité associée à la maladie, la morbidité découlant des effets psychologiques de la perte des cheveux peut être dévastatrice. Lorsque la pelade par plaques et le sous-type de la maladie sont identifiés, un schéma thérapeutique approprié peut être amorcé pour aider à arrêter la chute des cheveux et possiblement faire commencer la repousse. Les traitements de première intention sont la triamcinolone intralésionnelle avec des corticostéroïdes topiques ou du minoxidil ou les 2. Les médecins de famille peuvent prescrire ces traitements en toute sécurité et amorcer ces thérapies. Les cas plus avancés ou réfractaires pourraient avoir besoin de diphénylcyclopropénone topique ou d’anthraline topique. On peut traiter la perte de cils avec des analogues de la prostaglandine. Les personnes ayant subi une perte de cheveux abondante peuvent recourir à des options de camouflage ou à des prothèses capillaires. Il est important de surveiller les troubles psychiatriques en raison des effets psychologiques profonds de la perte de cheveux. Conclusion Les médecins de famille verront de nombreux patients qui perdent leurs cheveux. La reconnaissance de la pelade par plaques et la compréhension du processus pathologique sous-jacent permettent d’amorcer un schéma thérapeutique approprié. Les cas plus graves ou r

  2. Phenotype commitment in vascular smooth muscle cells derived from coronary atherosclerotic plaques: differential gene expression of endothelial Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    ML Rossi

    2009-06-01

    Full Text Available Unstable angina and myocardial infarction are the clinical manifestations of the abrupt thrombotic occlusion of an epicardial coronary artery as a result of spontaneous atherosclerotic plaque rupture or fissuring, and the exposure of highly thrombogenic material to blood. It has been demonstrated that the proliferation of vascular smooth muscle cells (VSMCs and impaired bioavailabilty of nitric oxide (NO are among the most important mechanisms involved in the progression of atherosclerosis. It has also been suggested that a NO imbalance in coronary arteries may be involved in myocardial ischemia as a result of vasomotor dysfunction triggering plaque rupture and the thrombotic response. We used 5’ nuclease assays (TaqMan™ PCRs to study gene expression in coronary plaques collected by means of therapeutic directional coronary atherectomy from 15 patients with stable angina (SA and 15 with acute coronary syndromes (ACS without ST elevation. Total RNA was extracted from the 30 plaques and the cDNA was amplified in order to determine endothelial nitric oxide synthase (eNOS gene expression. Analysis of the results showed that the expression of eNOS was significantly higher (p<0.001 in the plaques from the ACS patients. Furthermore, isolated VSMCs from ACS and SA plaques confirmed the above pattern even after 25 plating passages. In situ RT-PCR was also carried out to co-localize the eNOS messengers and the VSMC phenotype.

  3. Imaging Modalities to Identity Inflammation in an Atherosclerotic Plaque

    Directory of Open Access Journals (Sweden)

    Sunny Goel

    2015-01-01

    Full Text Available Atherosclerosis is a chronic, progressive, multifocal arterial wall disease caused by local and systemic inflammation responsible for major cardiovascular complications such as myocardial infarction and stroke. With the recent understanding that vulnerable plaque erosion and rupture, with subsequent thrombosis, rather than luminal stenosis, is the underlying cause of acute ischemic events, there has been a shift of focus to understand the mechanisms that make an atherosclerotic plaque unstable or vulnerable to rupture. The presence of inflammation in the atherosclerotic plaque has been considered as one of the initial events which convert a stable plaque into an unstable and vulnerable plaque. This paper systemically reviews the noninvasive and invasive imaging modalities that are currently available to detect this inflammatory process, at least in the intermediate stages, and discusses the ongoing studies that will help us to better understand and identify it at the molecular level.

  4. A comparative study on plaque vulnerability using constitutive equations.

    Science.gov (United States)

    Karimi, A; Navidbakhsh, M; Faghihi, S

    2014-03-01

    Atherosclerosis is the most serious and common form of cardiovascular disease in which plaque builds up inside the arteries. Peak plaque stress is considered as the main reason for plaque rupture, which results in heart attack and stroke. In the current research, the finite element method is used to anticipate plaque vulnerability, using human samples. A total of 23 healthy and atherosclerotic human coronary arteries (14 healthy and 9 atherosclerotic) were removed within 5 h postmortem. The samples were mounted on a uniaxial tensile test machine and the obtained mechanical properties were used in finite element models. The peak plaque stresses for the Ogden hyperelastic model were compared to the Mooney-Rivlin and Neo-Hookean outcomes. The results indicated that hypocellular plaque in all three models has the highest stress values compared to the cellular and calcified ones and, as a result, is quite prone to rupture. The calcified plaque type, in contrast, has the lowest stress values and remains stable. The results can be used in plaque vulnerability prediction and have clinical implications for interventions and surgeries such as balloon-angioplasty, cardiopulmonary bypass and stenting.

  5. Does the presence of the Helicobacter pylori in the dental plaque associate with its gastric infection? A meta-analysis and systematic review

    Directory of Open Access Journals (Sweden)

    Nader Navabi

    2011-01-01

    Conclusion: Co-infection of gastric H. pylori and dental plaque is reported by half of the studies. However, there is not enough evidence for the efficacy of dental treatment on prevention of recurrent gastric H. pylori infection.

  6. Demonstration of characteristic skin surface contours of extramammary Paget's disease and parapsoriasis en plaque by image analysis of negative impression replicas.

    Science.gov (United States)

    Kikuchi, Katsuko; Aiba, Setsuya; O'Goshi, Ken-ichiro; Yanai, Motohiro; Takahashi, Motoji; Kasai, Hidefumi; Tagami, Hachiro

    2002-10-01

    The surface contours of lesional skin of certain skin diseases, such as parapsoriasis en plaque (PEP) and extramammary Paget's disease (EMPD), in which there is a massive infiltration by non-epidermal cells, looks somewhat different from that of the adjacent normal skin, needless to state that they are apparently different from that of ordinary chronic inflammatory dermatoses where we found acanthotic epidermis accompanied by hyperkeratosis. We attempted to objectively characterize these unique skin surface changes qualitatively and quantitatively using non-invasive methods. Negative impression replicas were taken from the lesional skin of patients with EMPD or PEP as well as from the adjacent uninvolved skin. The findings were confirmed histologically. The replicas were examined by using computerized image analysis. Several parameters were analyzed that correlate with the changes in the anisotropy of the skin furrows (VC1), average skin roughness (KSD), average length of skin furrows (LEN), and number of skin furrows (NUM). There were significant decreases in KSD and NUM in EMPD, indicating a smoother skin surface in the lesional skin than in the adjacent normal skin. In contrast, the PEP lesion had an increase in VC1 and LEN and a decrease in NUM, which suggests larger skin ridges in the lesional skin than in the uninvolved skin. Thus the unique skin surface of the cutaneous disorders accompanied by epidermal invasion by non-epidermal cells, such as EMPD and PEP, was characterized both qualitatively and quantitatively using computerized image analysis of negative impression replicas.

  7. Effects of Low Carbohydrate High Protein (LCHP) diet on atherosclerotic plaque phenotype in ApoE/LDLR-/- mice: FT-IR and Raman imaging.

    Science.gov (United States)

    Wrobel, T P; Marzec, K M; Chlopicki, S; Maślak, E; Jasztal, A; Franczyk-Żarów, M; Czyżyńska-Cichoń, I; Moszkowski, T; Kostogrys, R B; Baranska, M

    2015-09-22

    Low Carbohydrate High Protein (LCHP) diet displays pro-atherogenic effects, however, the exact mechanisms involved are still unclear. Here, with the use of vibrational imaging, such as Fourier transform infrared (FT-IR) and Raman (RS) spectroscopies, we characterize biochemical content of plaques in Brachiocephalic Arteries (BCA) from ApoE/LDLR(-/-) mice fed LCHP diet as compared to control, recomended by American Institute of Nutrition, AIN diet. FT-IR images were taken from 6-10 sections of BCA from each mice and were complemented with RS measurements with higher spatial resolution of chosen areas of plaque sections. In aortic plaques from LCHP fed ApoE/LDLR(-/-) mice, the content of cholesterol and cholesterol esters was increased, while that of proteins was decreased as evidenced by global FT-IR analysis. High resolution imaging by RS identified necrotic core/foam cells, lipids (including cholesterol crystals), calcium mineralization and fibrous cap. The decreased relative thickness of the outer fibrous cap and the presence of buried caps were prominent features of the plaques in ApoE/LDLR(-/-) mice fed LCHP diet. In conclusion, FT-IR and Raman-based imaging provided a complementary insight into the biochemical composition of the plaque suggesting that LCHP diet increased plaque cholesterol and cholesterol esters contents of atherosclerotic plaque, supporting the cholesterol-driven pathogenesis of LCHP-induced atherogenesis.

  8. Atherosclerotic Plaque Destabilization in Mice: A Comparative Study.

    Directory of Open Access Journals (Sweden)

    Helene Hartwig

    Full Text Available Atherosclerosis-associated diseases are the main cause of mortality and morbidity in western societies. The progression of atherosclerosis is a dynamic process evolving from early to advanced lesions that may become rupture-prone vulnerable plaques. Acute coronary syndromes are the clinical manifestation of life-threatening thrombotic events associated with high-risk vulnerable plaques. Hyperlipidemic mouse models have been extensively used in studying the mechanisms controlling initiation and progression of atherosclerosis. However, the understanding of mechanisms leading to atherosclerotic plaque destabilization has been hampered by the lack of proper animal models mimicking this process. Although various mouse models generate atherosclerotic plaques with histological features of human advanced lesions, a consensus model to study atherosclerotic plaque destabilization is still lacking. Hence, we studied the degree and features of plaque vulnerability in different mouse models of atherosclerotic plaque destabilization and find that the model based on the placement of a shear stress modifier in combination with hypercholesterolemia represent with high incidence the most human like lesions compared to the other models.

  9. Smooth muscle cells healing atherosclerotic plaque disruptions are of local, not blood, origin in apolipoprotein E knockout mice

    DEFF Research Database (Denmark)

    Bentzon, Jacob F; Sondergaard, Claus S; Kassem, Mustafa;

    2007-01-01

    circulating bone marrow-derived progenitor cells. Here, we analyzed the contribution of this mechanism to plaque healing after spontaneous and mechanical plaque disruption in apolipoprotein E knockout (apoE-/-) mice. METHODS AND RESULTS: To determine the origin of SMCs after spontaneous plaque disruption......, irradiated 18-month-old apoE-/- mice were reconstituted with bone marrow cells from enhanced green fluorescent protein (eGFP) transgenic apoE-/- mice and examined when they died up to 9 months later. Plaque hemorrhage, indicating previous plaque disruption, was widely present, but no bone marrow-derived e......GFP+ SMCs were detected. To examine the origin of healing SMCs in a model that recapitulates more features of human plaque rupture and healing, we developed a mechanical technique that produced consistent plaque disruption, superimposed thrombosis, and SMC-mediated plaque healing in apoE-/- mice. Mechanical...

  10. Lipidome of atherosclerotic plaques from hypercholesterolemic rabbits.

    Science.gov (United States)

    Bojic, Lazar A; McLaren, David G; Shah, Vinit; Previs, Stephen F; Johns, Douglas G; Castro-Perez, Jose M

    2014-12-15

    The cellular, macromolecular and neutral lipid composition of the atherosclerotic plaque has been extensively characterized. However, a comprehensive lipidomic analysis of the major lipid classes within atherosclerotic lesions has not been reported. The objective of this study was to produce a detailed framework of the lipids that comprise the atherosclerotic lesion of a widely used pre-clinical model of plaque progression. Male New Zealand White rabbits were administered regular chow supplemented with 0.5% cholesterol (HC) for 12 weeks to induce hypercholesterolemia and atherosclerosis. Our lipidomic analyses of plaques isolated from rabbits fed the HC diet, using ultra-performance liquid chromatography (UPLC) and high-resolution mass spectrometry, detected most of the major lipid classes including: Cholesteryl esters, triacylglycerols, phosphatidylcholines, sphingomyelins, diacylglycerols, fatty acids, phosphatidylserines, lysophosphatidylcholines, ceramides, phosphatidylglycerols, phosphatidylinositols and phosphatidylethanolamines. Given that cholesteryl esters, triacylglycerols and phosphatidylcholines comprise greater than 75% of total plasma lipids, we directed particular attention towards the qualitative and quantitative assessment of the fatty acid composition of these lipids. We additionally found that sphingomyelins were relatively abundant lipid class within lesions, and compared the abundance of sphingomyelins to their precursor phosphatidylcholines. The studies presented here are the first approach to a comprehensive characterization of the atherosclerotic plaque lipidome.

  11. Lipidome of Atherosclerotic Plaques from Hypercholesterolemic Rabbits

    Directory of Open Access Journals (Sweden)

    Lazar A. Bojic

    2014-12-01

    Full Text Available The cellular, macromolecular and neutral lipid composition of the atherosclerotic plaque has been extensively characterized. However, a comprehensive lipidomic analysis of the major lipid classes within atherosclerotic lesions has not been reported. The objective of this study was to produce a detailed framework of the lipids that comprise the atherosclerotic lesion of a widely used pre-clinical model of plaque progression. Male New Zealand White rabbits were administered regular chow supplemented with 0.5% cholesterol (HC for 12 weeks to induce hypercholesterolemia and atherosclerosis. Our lipidomic analyses of plaques isolated from rabbits fed the HC diet, using ultra-performance liquid chromatography (UPLC and high-resolution mass spectrometry, detected most of the major lipid classes including: Cholesteryl esters, triacylglycerols, phosphatidylcholines, sphingomyelins, diacylglycerols, fatty acids, phosphatidylserines, lysophosphatidylcholines, ceramides, phosphatidylglycerols, phosphatidylinositols and phosphatidylethanolamines. Given that cholesteryl esters, triacylglycerols and phosphatidylcholines comprise greater than 75% of total plasma lipids, we directed particular attention towards the qualitative and quantitative assessment of the fatty acid composition of these lipids. We additionally found that sphingomyelins were relatively abundant lipid class within lesions, and compared the abundance of sphingomyelins to their precursor phosphatidylcholines. The studies presented here are the first approach to a comprehensive characterization of the atherosclerotic plaque lipidome.

  12. Coronary spasm, a pathogenic trigger of vulnerable plaque rupture

    Institute of Scientific and Technical Information of China (English)

    WANG Li-xin; L(U) Shu-zheng; ZHANG Wei-jun; SONG Xian-tao; CHEN Hui; ZHANG Li-jie

    2011-01-01

    Objective This coronary artery spasm review aimed to explore the most possible pathogenic trigger mechanism of vulnerable plaque rupture.Data sources Data used in this coronary artery spasm review were mainly from Medline and Pubmed in English.Study selection These reports from major review on coronary artery spasm.and these research included coronary artery conception,pathogenesis of spasm,mechanisms of plaque rupture,epidemiological evidence,clinical manifestation and the relationship between coronary artery spasm and vulnerable plaque rupture.Results Coronary artery spasm is somehow related to the presence of atherosclerotic intima disease in the coronary artery.However,chronic low-grade inflammation causes coronary vessel smooth muscle cell hypersensitivity,which can directely cause coronary artery spasm.Myocardial infarction and sudden cardiac death may be initiated by a sudden intense localized contraction of coronary artery smooth muscle.Conclusion Coronary artery spasm may be one trigger that can initiate and exacerbate vulnerable plaque rupture.

  13. Antibacterial effect of taurolidine (2%) on established dental plaque biofilm.

    Science.gov (United States)

    Arweiler, Nicole Birgit; Auschill, Thorsten Mathias; Sculean, Anton

    2012-04-01

    Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections. However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique and to compare it with the effect of NaCl and chlorhexidine (CHX), 18 subjects had to refrain from all mechanical and chemical hygiene measures for 24 h. A voluminous supragingival plaque sample was taken from the buccal surfaces of the lower molars and wiped on an objective slide. The sample was then divided into three equal parts and mounted with one of the three test or control preparations (a) NaCl, (b) taurolidine 2% and (c) CHX 0.2%. After a reaction time of 2 min, the test solutions were sucked of. Subsequently, the plaque biofilm was stained with fluorescence dye and vitality of the plaque flora was evaluated under the fluorescence microscope (VF%). Plaque samples treated with NaCl showed a mean VF of 82.42 ± 6.04%. Taurolidine affected mean VF with 47.57 ± 16.60% significantly (p taurolidine). Taurolidine possesses a significant antibacterial effect on the supragingival plaque biofilm which was, however, not as pronounced as that of CHX.

  14. Dental plaque biofilm in oral health and disease.

    Science.gov (United States)

    Seneviratne, Chaminda Jayampath; Zhang, Cheng Fei; Samaranayake, Lakshman Perera

    2011-01-01

    Dental plaque is an archetypical biofilm composed of a complex microbial community. It is the aetiological agent for major dental diseases such as dental caries and periodontal disease. The clinical picture of these dental diseases is a net result of the cross-talk between the pathogenic dental plaque biofilm and the host tissue response. In the healthy state, both plaque biofilm and adjacent tissues maintain a delicate balance, establishing a harmonious relationship between the two. However, changes occur during the disease process that transform this 'healthy' dental plaque into a 'pathogenic' biofilm. Recent advances in molecular microbiology have improved the understanding of dental plaque biofilm and produced numerous clinical benefits. Therefore, it is imperative that clinicians keep abreast with these new developments in the field of dentistry. Better understanding of the molecular mechanisms behind dental diseases will facilitate the development of novel therapeutic strategies to establish a 'healthy dental plaque biofilm' by modulating both host and microbial factors. In this review, the present authors aim to summarise the current knowledge on dental plaque as a microbial biofilm and its properties in oral health and disease.

  15. 数字图像分析技术定量分析牙菌斑的效果评价%Evaluation of dental plaque by quantitative digital image analysis system

    Institute of Scientific and Technical Information of China (English)

    黄振; 栾庆先

    2016-01-01

    目的:使用图像分析软件对牙菌斑染色图像进行分析,验证该技术的可操作性和实用性,考察该方法的可重复性,并评价不同菌斑染色方式对结果的影响。方法:从北京大学医学部口腔医学专业新入校学生中招募符合纳入标准的志愿者30人,菌斑染色后拍摄标准化口内前牙区数字图像,用Image Pro Plus 7.0软件进行图像分析,同时评价前牙区的Quigley-Hein菌斑指数。结果:图像分析计算所得菌斑染色面积百分比与临床检查记录的相应牙齿菌斑指数有较高的相关一致性,Spearman相关系数为0.776(P<0.01)。两名研究者用软件计算牙齿面积和菌斑面积的同类相关系数分别为0.956和0.930(P<0.01),Bland-Altman分析图显示仅有极个别的点在95%一致性界限以外。不同菌斑染色的图像分析结果显示,牙齿面积在两组间差异无统计学意义,但菌斑面积差异有统计学意义(P<0.01)。结论:该方法较易于操作掌握,所计算的菌斑百分比与传统的菌斑指数有较高的一致性,且重复性好,不同菌斑染色方法对图像分割结果影响不大,宜选用对菌斑敏感的菌斑染色剂进行图像分析。%Objective:To analyze the plaque staining image by using image analysis software,to verify the maneuverability,practicability and repeatability of this technique,and to evaluate the influence of different plaque stains.Methods:In the study,30 volunteers were enrolled from the new dental students of Peking University Health Science Center in accordance with the inclusion criteria.The digital images of the anterior teeth were acquired after plaque stained according to filming standardization.The image analysis was performed using Image Pro Plus 7.0,and the Quigley-Hein plaque indexes of the anterior teeth were evaluated.Results:The plaque stain area percentage and the corresponding dental plaque in-dex were

  16. Dental plaque control effect analysis on community residents by periodic oral health education%阶段性口腔健康教育对社区居民口腔菌斑控制的效果观察

    Institute of Scientific and Technical Information of China (English)

    唐世平; 葛风华; 张国明

    2015-01-01

    Objective To investigate the dental plaque control effect analysis on community residents by periodic oral health education .Methods Selected 200 cases community residents from January 2013 and January 2014 from Shenzhen baoan district ganoderma lucidum garden community as the observation objects .They were selected from east community and west community ,100 .divided into control group and the observation group according to the geographical position .The con‐trol group east community residents were given collective preach joint promotional material on a regular basis ,the observation group west community residents were given dental plaque control for 6 mouths .The dental plaque clearance and plaque vol‐ume changes before and after intervention of two groups patients were compared .Results Before the intervention , the dental plaque volume of the control group was (2 .78 ± 0 .03) ,the dental plaque volume of the observation group was (2 .86 ± 0 .05 ) ,there was no significantly different (P >0 .05) .After health education ,the dental plaque volume of the observation group was significantly less than that of the control group (2 .01 ± 0 .02)vs(2 .48 ± 0 .04) ,(P<0 .05) .Con‐clusions Periodic oral education can raise residents'awareness of oral object step by step ,with clear plaque skills and quality with quantity can be more clear plaque ,it can ensure people's oral health .%目的:探讨阶段性口腔健康教育对社区居民口腔菌斑控制的效果。方法以2013年1月~2014年1月深圳市宝安区灵芝园社区200名常住居民作为研究对象,人为按地理位置划分为东区和西区,各100名。其中以东区作为对照组,采取常规宣教方法。西区作为观察组,采取为期6个月的阶段性口腔健康教育的方式。比较两组菌斑清除率和干预前后菌斑量的变化。结果干预前对照组口腔菌斑量为(2.78±0.03)分,观察组为(2.86±0.05)分,两组

  17. Analysis and optimization of silicon wafers wire sawing; Analyse et optimisation du procede de decoupe de plaques de silicium

    Energy Technology Data Exchange (ETDEWEB)

    Rouault de Coligny, P.

    2002-09-15

    This work has been done at the Centre de Mise en Forme des Materiaux and supported by the Agence de l'Environnement et la Maitrise de l'Energie and Photowatt International SA. It concerns one of the stages of the production of photovoltaic solar cells: the cutting of multi-crystalline silicon wafers by wire sawing. A review of the literature combined with the observation of rough wafers shows that wire sawing involves 3-body abrasion and that material removal is achieved in a ductile manner and forms micro-chips. Therefore, the depth of indentation which is necessary for the ductile-fragile transition as shown by the review of the literature is not reached. The resulting abrasion can be described thanks to Archard's Law. The subsurface damage is 2.5 {mu}m deep. A thermal study has shown that the temperature of the cutting is no higher than about 50 deg. C and that it depends on how much heat can be evacuated by the wire. Analyzing the flaws of the wafers has enabled us to identify their origins and to find solutions. The study of the wire's wear has proved that its diameter can be reduced only if the wire is drawn continuously. Energy can be saved at various stages, the surface of the wafers can be improved, these three arguments plead for the suppression of the back and forth. A tribological device has been set up which allows us to study the abrasion of silicon in the same conditions as in the wire sawing. A mechanical model linking the bending of the wire to the parameters collected during the wire sawing process can predict how high the wire web will be in the transitional and permanent regimes, the contact pressure and the wire wear. Material removal by plane strain scratch tests has been numerically simulated. The orders of magnitude of wear coefficients are identical to those deduced from tribological simulations and to those measured on the saws. This approach has opened new prospects which will improve the process by optimizing the

  18. Butyrylcholinesterase in the life cycle of amyloid plaques.

    Science.gov (United States)

    Guillozet, A L; Smiley, J F; Mash, D C; Mesulam, M M

    1997-12-01

    Deposits of diffuse beta-amyloid (Abeta) may exist in the brain for many years before leading to neuritic degeneration and dementia. The factors that contribute to the putative transformation of the Abeta amyloid from a relatively inert to a pathogenic state remain unknown and may involve interactions with additional plaque constituents. Matching brain sections from 2 demented and 4 nondemented subjects were processed for the demonstration of Abeta immunoreactivity, butyrylcholinesterase (BChE) enzyme activity, and thioflavine S binding. Additional sections were processed for the concurrent demonstration of two or three of these markers. A comparative analysis of multiple cytoarchitectonic areas processed with each of these markers indicated that Abeta plaque deposits are likely to undergo three stages of maturation, ie, a "diffuse" thioflavine S-negative stage, a thioflavine S-positive (ie, compact) but nonneuritic stage, and a compact neuritic stage. A multiregional analysis showed that BChE-positive plaques were not found in cytoarchitectonic areas or cortical layers that contained only the thioflavine S-negative, diffuse type of Abeta plaques. The BChE-positive plaques were found only in areas containing thioflavine S-positive compact plaques, both neuritic and nonneuritic. Within such areas, almost all (>98%) BChE-containing plaques bound thioflavine S, and almost all (93%) thioflavine S plaques contained BChE. These results suggest that BChE becomes associated with amyloid plaques at approximately the same time that the Abeta deposit assumes a compact beta-pleated conformation. BChE may therefore participate in the transformation of Abeta from an initially benign form to an eventually malignant form associated with neuritic tissue degeneration and clinical dementia.

  19. Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients.

    Science.gov (United States)

    Otten, Marieke P T; Busscher, Henk J; Abbas, Frank; van der Mei, Henny C; van Hoogmoed, Chris G

    2012-10-01

    Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims. First, volunteers brushed 2 weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12 h after brushing and bacterial concentrations and viabilities were measured. The contributions of plaque and saliva towards substantivity were determined by combining control plaques with experimental plaque or saliva samples and subsequently assessing their viabilities. Bacterial compositions in the various plaque and saliva samples were compared using denaturing gradient gel electrophoresis. The viabilities of plaques after brushing with Colgate-Total® and Crest-Pro-Health® were smaller than of control plaques and up to 12 h after brushing with Crest-Pro-Health® plaques still contained effective, residual antibacterial activity against control plaques. No effective, residual antibacterial activity could be measured in saliva samples after brushing. There was no significant difference in bacterial composition of plaque or saliva after brushing with the different toothpastes. Plaque-left-behind after mechanical cleaning contributes to the substantive action of an antibacterial toothpaste containing stannous fluoride (Crest-Pro-Health®). The absorptive capacity of plaque-left-behind after brushing is of utmost clinical importance, since plaque is predominantly left behind in places where its removal and effective killing matter most. Therewith this study demonstrates a clear and new beneficial effect of the use of antibacterial toothpastes.

  20. Infrared radiant ceramic plaques; Plaques radiantes ceramiques a infrarouge

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-05-01

    Infrared plaques developed by MORGAN MATROC can now produce radiant heat from both natural and bottled gas with substantially lower NOx levels, and greater fuel efficiency and cleanliness, than other mass produced gas burning systems. The properties of this ceramic system, in particular very low thermal conductivity, allied to the infrared process for heat conversion, result in efficient radiation of energy. Morgan Matroc now claims half of the world-wide market of infrared plaque. (authors)

  1. Amyloid Plaques in Retina for Diagnosis in Alzheimer’s patients: unsatisfactory results from a mata-analysis

    Directory of Open Access Journals (Sweden)

    Jiangling Jiang

    2016-11-01

    Full Text Available Background: Detection of retinal β-amyloid (Aβ peptide accumulation is a novel diagnostic method for Alzheimer’s disease (AD, but there is, as yet, no conclusive evidence of its accuracy.Aim: To identify the diagnostic accuracy of pathological retinal Aβ detection for AD by a meta-analytic approach.Methods: Electronic and reference searches were conducted to identify studies related to the diagnostic effects of retinal Aβ detection in AD that met pre-defined inclusion criteria. The QUADAS-2 tool was employed to assess the risk of bias, and Review Manager plus the Open Meta-Analyst were used to perform the data analysis.Results: From 493 unduplicated reports, five studies with small sample sizes were included in this review. Six staining methods were employed. The eligible studies showed extremely broad ranges of sensitivity (0 to 1.00 and specificity (0.50 to 1.00 with substantial heterogeneity. The estimates of positive likelihood ratio (PLR, negative likelihood ratio (NLR, diagnostic odds ratio (DOR were also extremely varied (from 0.71 to 11.57 for PLR, from 0.04 to 1.11 for NLR, and from 0.69 to 297.00 for DOR.Conclusions: The limited number of eligible studies and their methodological heterogeneity make it impossible to come to a conclusion whether pathological retinal Aβ detection is an effective diagnostic tool for AD. More studies, especially large surveys investigating retina Aβ load with quantitative methods among consecutive or random samples, are needed to determine the accuracy of Aβ detection for diagnosing AD.

  2. Majorana Electroformed Copper Mechanical Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Overman, Nicole R.; Overman, Cory T.; Kafentzis, Tyler A.; Edwards, Danny J.; Hoppe, Eric W.

    2012-04-30

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay. The DEMONSTRATOR will utilize ultra high purity electroformed copper for a variety of detector components and shielding. A preliminary mechanical evaluation was performed on the Majorana prototype electroformed copper material. Several samples were removed from a variety of positions on the mandrel. Tensile testing, optical metallography, scanning electron microscopy, and hardness testing were conducted to evaluate mechanical response. Analyses carried out on the Majorana prototype copper to this point show consistent mechanical response from a variety of test locations. Evaluation shows the copper meets or exceeds the design specifications.

  3. The effect of an essential-oils mouthrinse as compared to a vehicle solution on plaque and gingival inflammation: a systematic review and meta-analysis

    NARCIS (Netherlands)

    M.P.C. Van Leeuwen; D.E. Slot; G.A. Van der Weijden

    2014-01-01

    Objective The purpose of this review was to systematically evaluate the effects of an alcohol vehicle solution (V-Sol) compared with an essential-oils mouthwash (EOMW) and if available with a water-based control (WC) on plaque, gingival inflammation parameters and extrinsic tooth staining. Materials

  4. Comparison of triclosan and stannous fluoride dentifrices on parameters of gingival inflammation and plaque scores: a systematic review and meta-analysis

    NARCIS (Netherlands)

    Sälzer, S.A.; Slot, D.E.; Dörfer, C.E.; van der Weijden, G.A.

    2015-01-01

    Objective To systematically review the literature to compare the efficacy of triclosan (Tcs) and stannous fluoride (SnF) dentifrices on parameters of gingivitis and plaque scores. Materials and Methods Medline, EMBASE and Cochrane Central Register of Controlled Trials were searched up to March 2013

  5. Comparison of triclosan and stannous fluoride dentifrices on parameters of gingival inflammation and plaque scores: a systematic review and meta-analysis

    NARCIS (Netherlands)

    Sälzer, S.A.; Slot, D.E.; Dörfer, C.E.; van der Weijden, G.A.

    2015-01-01

    Objective To systematically review the literature to compare the efficacy of triclosan (Tcs) and stannous fluoride (SnF) dentifrices on parameters of gingivitis and plaque scores. Materials and Methods Medline, EMBASE and Cochrane Central Register of Controlled Trials were searched up to March 2013

  6. Evidence for xylitol 5-P production in human dental plaque

    Energy Technology Data Exchange (ETDEWEB)

    Waaler, S.M. (Department of Preclinical Techniques and Material Sciences and Department of Pedodontics, Dental Faculty, University of Oslo, Oslo (Norway))

    1992-01-01

    The Turku sugar studies indicated that xylitol may possess a caries-therapeutic effect. More recent data show that xylotol exhibits a bacteriostatic activity on a wide range of bacteria based on uptake and expulsion of xylitol. Intracellular xylitol 5-P appears to be a key substance associated with inhibition of bacterial metabolism by xylitol. This has been shown in studies with pure strains of bacteria, mainly Streptococcus mutans. The aim of the present study was to examine if production of xylitol 5-P occurs in freshly collected dental plaque which is exposed to labeled xylitol. Plaque extracts were analyzed by thin-layer chromatography combined with autoradiography and high performance liquid chromatography. Strong indications were obtained that xylitol 5-P is readily produced by dental plaque. No other significant xylitol metabolites were identified. The bacteriostatic properties of xylitol in plaque are a mechanism which may well account for the caries-therapeutic effect of xylitol. (au).

  7. Analysis of carotid artery plaque and wall boundaries on CT images by using a semi-automatic method based on level set model

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Sannia, Stefano; Ledda, Giuseppe [University of Cagliari - Azienda Ospedaliero Universitaria di Cagliari, Department of Radiology, Monserrato, Cagliari (Italy); Gao, Hao [University of Strathclyde, Signal Processing Centre for Excellence in Signal and Image Processing, Department of Electronic and Electrical Engineering, Glasgow (United Kingdom); Acharya, U.R. [Ngee Ann Polytechnic University, Department of Electronics and Computer Engineering, Clementi (Singapore); Suri, Jasjit S. [Biomedical Technologies Inc., Denver, CO (United States); Idaho State University (Aff.), Pocatello, ID (United States)

    2012-11-15

    The purpose of this study was to evaluate the potentialities of a semi-automated technique in the detection and measurement of the carotid artery plaque. Twenty-two consecutive patients (18 males, 4 females; mean age 62 years) examined with MDCTA from January 2011 to March 2011 were included in this retrospective study. Carotid arteries are examined with a 16-multi-detector-row CT system, and for each patient, the most diseased carotid was selected. In the first phase, the carotid plaque was identified and one experienced radiologist manually traced the inner and outer boundaries by using polyline and radial distance method (PDM and RDM, respectively). In the second phase, the carotid inner and outer boundaries were traced with an automated algorithm: level-set-method (LSM). Data were compared by using Pearson rho correlation, Bland-Altman, and regression. A total of 715 slices were analyzed. The mean thickness of the plaque using the reference PDM was 1.86 mm whereas using the LSM-PDM was 1.96 mm; using the reference RDM was 2.06 mm whereas using the LSM-RDM was 2.03 mm. The correlation values between the references, the LSM, the PDM and the RDM were 0.8428, 0.9921, 0.745 and 0.6425. Bland-Altman demonstrated a very good agreement in particular with the RDM method. Results of our study indicate that LSM method can automatically measure the thickness of the plaque and that the best results are obtained with the RDM. Our results suggest that advanced computer-based algorithms can identify and trace the plaque boundaries like an experienced human reader. (orig.)

  8. Measuring early plaque formation clinically.

    Science.gov (United States)

    Maliska, Alessandra N; Weidlich, Patricia; Gomes, Sabrina C; Oppermann, Rui V

    2006-01-01

    To test a system of measuring early plaque formation (EPF) and its subgingival extension as related to the presence or absence of a plaque free zone (PFZ). EPF was measured by three independent examiners following two consecutive 72-hour periods of undisturbed plaque build-up. One of the examiners further measured EPF following a 96-hour period in the presence of chlorhexidine or placebo. The classification system was composed of criterion 0 (plaque-free dental surface), criterion 1 (presence of plaque and PFZ) and criterion 2 (absence of PFZ, subgingival extension of plaque). Intra- and inter-examiner reliability were evaluated by means of the percentage of absolute agreement (c), Kappa (k) and Kendall (kd) coefficients. The third experiment consisted of a double-blind, placebo-controlled, cross-over trial. Plaque build-up in the presence of 0.12% chlorhexidine was assessed by employing the classification system described. The percentage of absolute intra- and inter-examiner agreement ranged from 85.43% to 75.63% and from 77.31% to 75.35% respectively. Chlorhexidine and placebo rinses showed similar percentages of criterion 1 surfaces, 62.6% and 51.5% respectively (p = 0.343). Of the surfaces, 44.3% showed criterion 2 after the use of placebo, while 3.4% of surfaces showed this criterion with the chlorhexidine (p = 0.007). The events associated with EPF can be appropriately scored with this classification system. Chlorhexidine rinses inhibit both the plaque colonization of the dental surfaces as well as its subgingival extension.

  9. Periodontal pathogens in atheromatous plaque

    Directory of Open Access Journals (Sweden)

    Saroj K. Rath

    2014-01-01

    Full Text Available Background: There has been increasing attention paid in recent years to the possibility that oral bacterial infection, particularly periodontal disease may influence the initiation and or progression of systemic diseases. These studies confirm the observation that heart disease is the most commonly found systemic condition in patients with periodontal disease. Moreover, the literature has also highlighted substantial evidence indicating the presence of Gram-negative periodontal pathogens in atheromatous plaques. Aim: This study intends to investigate the possible association between periodontal health and coronary artery disease by evaluating periodontal status, association between the periodontal plaque and coronary atheromatous plaques for presence of micro-organisms such as, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia. Materials and methods: A case-control study was designed with seven patients who had undergone coronary endarterectomy for cardiovascular disease and 28 controls. The periodontal examination for cases was performed 1 day before vascular surgery and the controls were clinically examined. The atheromatous plaque sample collected during endarterectomy and the intraoral plaque samples were subjected to polymerase chain reaction for identification of A. actinomycetemcomitans, P. gingivalis, P. intermedia and T. forsythia. Results: The presence of periodontal bacteria DNA in coronary atheromatous plaques and sub-gingival plaque samples of the same patients was confirmed by this study. CONCLUSION A correlation was established between putative bacteria contributing to atheromatous plaques and species associated with periodontal disease. One particularly important study to be carried out is the investigation of a possible clinically meaningful reduction in coronary heart disease resulting from the prevention or treatment of periodontal disease.

  10. High shear stress relates to intraplaque haemorrhage in asymptomatic carotid plaques

    DEFF Research Database (Denmark)

    Tuenter, A.; Selwaness, M.; Arias Lorza, A.

    2016-01-01

    BACKGROUND AND AIMS: Carotid artery plaques with vulnerable plaque components are related to a higher risk of cerebrovascular accidents. It is unknown which factors drive vulnerable plaque development. Shear stress, the frictional force of blood at the vessel wall, is known to influence plaque...... estimating equations analysis, adjusting for age, sex and carotid wall thickness. RESULTS: The study group consisted of 93 atherosclerotic carotid arteries of 74 participants. In plaques with higher maximum shear stresses, IPH was more often present (OR per unit increase in maximum shear stress (log...... formation. We evaluated the association between shear stress and plaque components (intraplaque haemorrhage (IPH), lipid rich necrotic core (LRNC) and/or calcifications) in relatively small carotid artery plaques in asymptomatic persons. METHODS: Participants (n = 74) from the population-based Rotterdam...

  11. Plaque biofilms: the effect of chemical environment on natural human plaque biofilm architecture.

    Science.gov (United States)

    Robinson, C; Strafford, S; Rees, G; Brookes, S J; Kirkham, J; Shore, R C; Watson, P S; Wood, S

    2006-11-01

    The architecture of microbial biofilms especially the outer regions have an important influence on the interaction between biofilm and local environment particularly on the flux of materials into and out of biofilm compartments and as a consequence, biofilm metabolic behaviour. In the case of dental plaque biofilms, architecture will determine access of nutrients including acidogenic substrates and therapeutic materials to the microbial biomass and to the underlying tooth surface. Manipulation of this architecture may offer a means of altering mass transfer into the whole biofilm and biomass and raises the possibility of improving access of therapeutics. Plaque biofilms formed in vivo on human enamel were subjected to a number of different chemical conditions while under observation by confocal laser scanning microscopy in reflection mode. In this way the outer 50-100 microm or so of the biofilms was examined. Density and distribution of biomass were recorded as degree of reflectance. The amount and density of biofilm biomass increased from the plaque saliva interface towards the interior. Plaque biofilms were robust and little affected by mechanical manipulation, high ionic strength or low pH (2.5). Detergent (SLS), however, often appeared to either remove biomass and/or dramatically reduce its density.

  12. Reducing allergic symptoms through eliminating subgingival plaque

    Directory of Open Access Journals (Sweden)

    Haryono Utomo

    2008-12-01

    Full Text Available Background: Elimination of subgingival plaque for prevention and treatment of periodontal diseases through scaling is a routine procedure. It is also well-known that periodontal disease is related to systemic diseases. Nevertheless, the idea how scaling procedures also able to reduce allergic symptoms i.e. eczema and asthma, is not easily accepted, because it is contradictory to the “hygiene hypothesis”. However, since allergic symptoms also depend on variable factors such as genetic, environmental and infection factors; every possible effort to eliminate or avoid from these factors had to be considered. Subgingival plaque is a source of infection, especially the Gram-negative bacteria that produced endotoxin (lipopolysaccharides, LPS, a potential stimulator of immunocompetent cells, which may also related to allergy, such as mast cells and basophils. In addition, it also triggers the “neurogenic switching” mechanism which may be initiated from chronic gingivitis. Objective: This case report may explain the possible connection between subgingival plaque and allergy based on evidence-based cases. Case: Two adult siblings who suffered from chronic gingivitis also showed different manifestations of allergy that were allergic dermatitis and asthma for years. They were also undergone unsuccessful medical treatment for years. Oral and topical corticosteroids were taken for dermatitis and inhalation for asthma. Case Management: Patients were conducted deep scaling procedures, allergic symptoms gradually diminished in days even though without usual medications. Conclusion: Concerning to the effectiveness of scaling procedures which concomitantly eliminate subgingival plaque in allergic patients, it concluded that this concept is logical. Nevertheless, further verification and collaborated study with allergic expert should be done.

  13. Aortic atherosclerotic plaque detection using a multiwavelength handheld photoacoustic imaging system

    Science.gov (United States)

    Hirano, Susumu; Namita, Takeshi; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

    2016-03-01

    Patients affected by diseases caused by arteriosclerosis are increasing. Atherosclerosis, which is becoming an especially difficult health problem, forms plaques from lipids such as cholesterol located in walls of the aorta, cerebral artery, and coronary artery. Because lipid-rich plaques are vulnerable and because arterial rupture causes acute vascular occlusion, early detection is crucially important to prevent plaque growth and rupture. Ultrasound systems can detect plaques but cannot discriminate between vulnerable and equable plaques. To evaluate plaques non-invasively and easily, we developed a handheld photoacoustic imaging device. Its usefulness was verified in phantom experiments with a bovine aorta in which mimic plaque had been embedded. Photoacoustic images taken at wavelengths that produce high light absorbance by lipids show strong photoacoustic signals from the boundary of the mimic plaque. Results confirmed that our system can evaluate plaque properties by analysis with the photoacoustic spectrum. The effects of surrounding tissues and tissue components on plaque evaluation were investigated using a layered phantom. The mimic plaque located under a 6 mm blood layer was also evaluated. Results of these analyses demonstrate the system's usefulness.

  14. Advanced human carotid plaque progression correlates positively with flow shear stress using follow-up scan data: an in vivo MRI multi-patient 3D FSI study.

    Science.gov (United States)

    Yang, Chun; Canton, Gador; Yuan, Chun; Ferguson, Marina; Hatsukami, Thomas S; Tang, Dalin

    2010-09-17

    Although it has been well-accepted that atherosclerosis initiation and early progression correlate negatively with flow wall shear stresses (FSS), increasing evidence suggests mechanisms governing advanced plaque progression are not well understood. Fourteen patients were scanned 2-4 times at 18 month intervals using a histologically validated multi-contrast magnetic resonance imaging (MRI) protocol to acquire carotid plaque progression data. Thirty-two scan pairs (baseline and follow-up scans) were formed with slices matched for model construction and analysis. 3D fluid-structure interaction (FSI) models were constructed and plaque wall stress (PWS) and flow shear stress (FSS) were obtained from all matching lumen data points (400-1000 per plaque; 100 points per matched slice) to quantify correlations with plaque progression measured by vessel wall thickness increase (WTI). Using FSS and PWS data from follow-up scan, 21 out of 32 scan pairs showed a significant positive correlation between WTI and FSS (positive/negative/no significance ratio=21/8/3), and 26 out of 32 scan pairs showed a significant negative correlation between WTI and PWS (positive/negative/no significance ratio=2/26/4). The mean FSS value of lipid core nodes (n=5294) from all 47 plaque models was 63.5dyn/cm(2), which was 45% higher than that from all normal vessel nodes (n=27553, p<0.00001). The results from this intensive FSI study indicate that flow shear stress from follow-up scan correlates positively with advanced plaque progression which is different from what has been observed in plaque initiation and early-stage progression. It should be noted that the correlation results do not automatically lead to any causality conclusions.

  15. Mechanical tolerance stackup and analysis

    CERN Document Server

    Fischer, Bryan R

    2004-01-01

    BackgroundDimensioning and TolerancingTolerance Format and Decimal PlacesConverting Plus/Minus Dimensions and Tolerances into Equal Bilaterally Toleranced DimensionsVariation and Sources of VariationTolerance AnalysisWorst-case Tolerance StackupsStatistical Tolerance StackupsGeometric Dimensioning and Tolerancing (GD&T)Converting Plus/Minus Tolerancing to Positional Tolerancing and Projected Tolerance ZonesDiametral and Radial Tolerance StackupsSpecifying Material Condition Modifiers and Their Effect on Tolerance Stackups The Tolerance Stackup SketchThe Tolerance Stackup Report FormTolerance S

  16. Reproducibility of Two 3-D Ultrasound Carotid Plaque Quantification Methods

    DEFF Research Database (Denmark)

    Graebe, Martin; Entrekin, Robert; Collet-Billon, Antoine;

    2014-01-01

    -sectional, 2-D freehand sweep and a mechanical 3-D ultrasound investigation of 62 carotid artery plaques is reported with intra-class correlation coefficients (with 95% confidence intervals). Inter-observer agreement was 0.60 (0.29-0.77) for the freehand method and 0.89 (0.83-0.93) for the mechanical 3-D...

  17. Denitrification in human dental plaque

    Directory of Open Access Journals (Sweden)

    Verstraete Willy

    2010-03-01

    Full Text Available Abstract Background Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate (NO3- concentrations in the millimolar range and that dental plaque houses bacteria that can reduce this NO3- to nitrite (NO2-. Results We show that dental plaque mediates denitrification of NO3- to nitric oxide (NO, nitrous oxide (N2O, and dinitrogen (N2 using microsensor measurements, 15N isotopic labelling and molecular detection of denitrification genes. In vivo N2O accumulation rates in the mouth depended on the presence of dental plaque and on salivary NO3- concentrations. NO and N2O production by denitrification occurred under aerobic conditions and was regulated by plaque pH. Conclusions Increases of NO concentrations were in the range of effective concentrations for NO signalling to human host cells and, thus, may locally affect blood flow, signalling between nerves and inflammatory processes in the gum. This is specifically significant for the understanding of periodontal diseases, where NO has been shown to play a key role, but where gingival cells are believed to be the only source of NO. More generally, this study establishes denitrification by human-associated microbial communities as a significant metabolic pathway which, due to concurrent NO formation, provides a basis for symbiotic interactions.

  18. Plaque control and oral hygiene methods

    LENUS (Irish Health Repository)

    Harrison, Peter

    2017-06-01

    The experimental gingivitis study of Löe et al.1 demonstrated a cause and effect relationship between plaque accumulation and gingival inflammation, and helped to establish plaque\\/biofilm as the primary risk factor for gingivitis. When healthy individuals withdrew oral hygiene efforts, gingival inflammation ensued within 21 days in all subjects. Once effective plaque removal was recommenced, clinical gingival health was quickly re-established – indicating that plaque-associated inflammation is modifiable by plaque control. As current consensus confirms that gingivitis and periodontitis may be viewed as a continuum of disease,2 the rationale for achieving effective plaque control is clear.

  19. Characterization of atherosclerotic plaque-depositions by infrared, Raman and CARS microscopy

    Science.gov (United States)

    Matthäus, Christian; Bergner, Gero; Krafft, Christoph; Dietzek, Benjamin; Romeike, Bernd F. M.; Brehm, Bernhard R.; Popp, Jürgen

    2011-07-01

    Atherosclerotic plaques are mainly composed of proteoglycans, triglycerides, cholesterol, cholesterolester and crystalline calcium. From histopathological characterizations it is known that the composition of these atherosclerotic plaques can vary to a great extent, due to different risk factors as smoking, hyperlipedemia, or genetic background ect. The individual plaque components can be spectroscopically easily identified. Furthermore, spectroscopic imaging technologies offer the possibility to study the plaque compositions in a more quantitative manner than traditional staining techniques. Here, we compare the potential of IR, Raman and CARS microscopy to characterize the constitution of atherosclerotic plaques as well as the structure of the surrounding tissue. For data analysis and image reconstruction spectral decomposition algorithms such as vertex component analysis (VCA) were introduced. The results are in good agreement with the histopathology. Aim of the study is to correlate the compositional characteristics of atherosclerotic plaques with individual disease patterns.

  20. Control Engineering Analysis of Mechanical Pitch Systems

    Science.gov (United States)

    Bernicke, Olaf; Gauterin, Eckhard; Schulte, Horst; Zajac, Michal

    2014-12-01

    With the help of a local stability analysis the coefficient range of a discrete damper, used for centrifugal forced, mechanical pitch system of small wind turbines (SWT), is gained for equilibrium points. - By a global stability analysis the gained coefficient range can be validated. An appropriate approach by Takagi-Sugeno is presented in the paper.

  1. Evaluation of the dentogingival area during early plaque formation.

    Science.gov (United States)

    Weidlich, P; Lopes de Souza, M A; Oppermann, R V

    2001-07-01

    The aims of this investigation were to evaluate the pattern of supragingival plaque formation in the dentogingival area within 96 hours after abstinence from mechanical plaque control and to clinically analyze the gingival inflammatory response observed. Six male volunteers, 20 to 23 years of age, had their upper incisors and cuspids polished. Four independent periods of no mechanical plaque control--24, 48, 72, and 96 hours--were instituted. In each period, plaque was disclosed and standardized individual photographs were taken. Impressions were taken and replicas were analyzed by scanning electron microscopy. Gingival crevicular fluid (GCF) was collected at baseline and 96 hours. The height of the gingival papilla was measured at baseline, 24, and 96 hours. Results showed the presence of a plaque-free zone (PFZ) along the gingival margin up to 72 hours. After 96 hours, there was a significant reduction in the presence of PFZ in the proximal thirds of the buccal surface when compared to the other experimental periods. At the end of the study, there was a significant increase in the GCF flow as well as edema of the interdental papilla, when compared to baseline values. The PFZ observed during the initial phase was less apparent at the 96-hour period. At this time, there was an increase in the gingival inflammatory response, represented clinically by increased GCF flow and edema.

  2. A Patient With Plaque Type Morphea Mimicking Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Wardhana Wardhana

    2015-04-01

    Full Text Available Morphea is an uncommon connective tissue disease with the most prominent feature being thickening or fibrosis of the dermal without internal organ involvement. It is also known as a part of localized scleroderma. Based on clinical presentation and depth of tissue involvement, morphea is classified into several forms, and about two thirds of adults with morphea have plaque type. Overproduction of collagen production by fibroblast is the cause of abnormality in morphea, and the hyperactivity mechanism of fibroblast is still unknown, although there are several mechanisms already proposed. Plaque type morphea is actually a benign and self limited. Plaque type morphea that mimicking systemic lupus erythematosus in clinical appearance, such as alopecia and oral mucosal ulcers, is uncommon. A case of plaque type morphea mimicking systemic lupus erythematosus in a 20 year old woman was discussed. The patient was treated with local and systemic immunosuppressant and antioxydant. The patient’s condition is improved without any significant side effects. Key words: morphea, plaque type.

  3. Comparison of Manual and Electric Toothbrush in Dental Plaque Removal: A Clinical Trial

    Directory of Open Access Journals (Sweden)

    Sheikh-Al-Eslamian

    2014-06-01

    Full Text Available Background Mechanical oral hygiene procedures are the most effective means of plaque removal and toothbrush is the most commonly used tool for mechanical plaque removal worldwide. There is an array of available manual and electric toothbrushes in the market. Thus, choosing the best one for dental plaque removal can be of great help for patients. Objectives This study aimed at compare the efficacy of dental plaque removal using a manual and an electric toothbrush. Materials and Methods This experimental, single-blinded sequential clinical trial was conducted on 12 patients (ten females and two males who aged 21 to 30 years old. The tested manual toothbrush was 35-mm soft Oral-B Pulsar and the electric one was Oral-B Professional Care 8500 DLX chargeable D18. Patients’ dental plaque score was set as zero through scaling, root planning, and polishing. Subjects were avoided tooth cleaning for three days and on day four, plaque accumulation was assessed using Tureskey's modification of Quigley and Hein plaque index. Results The mean of plaque index was 2.13 ± 0.83 and 2.11 ± 1.01 in the manual and electric toothbrush groups, respectively. No significant difference was detected between the study toothbrushes in terms of plaque removal (P = 0.374; however, with the manual tooth brushing, plaque removal was significantly greater in the buccal than in lingual surface and in the maxilla than in the mandible (P = 0.03 and P = 0.015, respectively. Conclusions Similar to previous studies, this study could not show the superiority of electric toothbrush over manual in plaque removal. After 72 hours, the mean of plaque index was greater in buccal than in lingual surface, which may be attributed to the natural cleansing action of the tongue.

  4. En plaque meningioma with angioinvasion

    Directory of Open Access Journals (Sweden)

    Basu Keya

    2010-04-01

    Full Text Available En plaque meningioma is a rare type of meningioma characterized by infiltrative nature, sheet-like growth and at times invading the bone. We report here a case of en plaque meningioma with typical grade I histomorphology along with unusual feature of angioinvasion. The patient was a 55-year-old man presenting with headache and painful proptosis of right eye. Imaging modalities revealed an en -plaque meningioma extending into the right sylvian fissure, with thickening of right temporal calvarium, greater wing of sphenoid and extension into the orbit. Magnetic resonance angiography showed medial displacement of right middle cerebral artery. The tumor was removed from the sylvian fissure and right temporal convexity. However, only subtotal removal of the intraorbital part was possible. Histology showed a meningothelial meningioma with low tumor cell proliferation, but infiltration into the bone, skeletal muscle and angioinvasion. Recognition of meningiomas en plaque is useful, as these tumors are difficult to resect completely, and are more prone to undergo recurrence or malignant change. In addition, angioinvasion seen in this tumor may have additional prognostic significance.

  5. Plaque inflammation and unstable morphology are associated with early stroke recurrence in symptomatic carotid stenosis.

    LENUS (Irish Health Repository)

    Marnane, Michael

    2014-03-01

    Although symptomatic carotid stenosis is associated with 3-fold increased risk of early stroke recurrence, the pathophysiologic mechanisms of high early stroke risk have not been established. We aimed to investigate the relationship between early stroke recurrence after initial symptoms and histological features of plaque inflammation and instability in resected carotid plaque.

  6. Effects of intima stiffness and plaque morphology on peak cap stress

    NARCIS (Netherlands)

    Akyildiz, A.C.; Speelman, L.; Van Brummelen, H.; Gutiérrez, M.A.; Virmani, R.; Van der Lugt, A.; Van der Steen, A.F.W.; Wentzel, J.J.; Gijsen, F.J.H.

    2011-01-01

    Background: Rupture of the cap of a vulnerable plaque present in a coronary vessel may cause myocardial infarction and death. Cap rupture occurs when the peak cap stress exceeds the cap strength. The mechanical stress within a cap depends on the plaque morphology and the material characteristics of

  7. Effects of intima stiffness and plaque morphology on peak cap stress

    NARCIS (Netherlands)

    A.C. Akyildiz (Ali); L. Speelman (Lambert); H. van Brummelen (Harald); M.A. Gutiérrez (Miguel); R. Virmani (Renu); A. van der Lugt (Aad); A.F.W. van der Steen (Ton); J.J. Wentzel (Jolanda); F.J.H. Gijsen (Frank)

    2011-01-01

    textabstractBackground: Rupture of the cap of a vulnerable plaque present in a coronary vessel may cause myocardial infarction and death. Cap rupture occurs when the peak cap stress exceeds the cap strength. The mechanical stress within a cap depends on the plaque morphology and the material

  8. Mechanical Analysis of high precision manipulator

    Directory of Open Access Journals (Sweden)

    O.J. Elle

    1995-10-01

    Full Text Available It is of great importance that high precision manipulators are well designed from a mechanical point of view. A thorough analysis of all mechanical aspects concerning an accurate manipulator will make a good basis for further design. This paper presents a new approach to mechanical analysis of high-precision manipulators. A typical six axis anthropomorphic manipulator configuration is chosen as a model for the analysis. The paper is divided into two main parts; static deformation analysis and dynamic analysis. The static deformation analysis consists of three sub-parts; link deformation, joint deformation and total mechanical deformation. A simple fixed beam deformation model is used to simulate every link. Both specific gravity and a load attached at the end of the beam is considered. By varying material, outer dimensions and wall thickness it is possible to determine optimal values. Looking at the whole structure with an attacking force at the end, it is possible to select appropriate motor/transmission combinations. Each combination represents compliance and combined with the arm compliance the total deformation can be found. The result shows that deformation due to compliance in the joints represents 97

  9. Can anti-erosion dentifrices also provide effective plaque control?

    Science.gov (United States)

    Bellamy, P G; Prendergast, M; Strand, R; Yu, Z; Day, T N; Barker, M L; Mussett, A J

    2011-08-01

    While gingivitis and caries continue to be prevalent issues, there is growing concern about dental erosion induced by dietary acids. An oral hygiene product that protects against all these conditions would be beneficial. This study investigated the potential of two anti-erosion dentifrices to inhibit plaque. This was a randomized, three-period, two-treatment, double-blind, crossover study evaluating a stannous chloride/sodium fluoride dentifrice (SnCl(2)/NaF, blend-a-med(®) Pro Expert) and a popular anti-erosion dentifrice (NaF, Sensodyne(®) ProNamel(™)). During Period 3, subjects were randomized to repeat one treatment to evaluate any product carryover effects. Each treatment period was 17 days. Test dentifrices were used with a standard manual toothbrush. Digital plaque image analysis (DPIA) was employed at the end of each period to evaluate plaque levels (i) overnight (am prebrush); (ii) post-brushing with the test product (am post-brush); and (iii) mid-afternoon (pm). Analysis was conducted via an objective computer algorithm, which calculated total area of visible plaque. Twenty-seven subjects completed the study. At all time points, subjects had statistically significantly (P ≤ 0.0001) lower plaque levels after using the SnCl(2)/NaF dentifrice than the NaF dentifrice. The antiplaque benefit for the SnCl(2)/NaF dentifrice versus the NaF dentifrice was: am prebrush = 26.0%; am post-brushing = 27.9%; pm = 25.7%. The SnCl(2)/NaF dentifrice provided significantly greater daytime and overnight plaque inhibition than the NaF toothpaste. When recommending dentifrice to patients susceptible to dental erosion, clinicians can consider one that also inhibits plaque. © 2010 John Wiley & Sons A/S.

  10. Analysis of frequency characteristics of compliant mechanisms

    Institute of Scientific and Technical Information of China (English)

    WANG Wenjing; YU Yueqing

    2007-01-01

    Much work is needed for a further study on the dynamic analysis of compliant mechanisms to improve their performance and operational accuracy.This paper uses the finite element method to develop a dynamic equation of the compliant mechanism.Natural frequencies and modes are derived.Using the differentials of a stiffness matrix to design parameters,a method for calculating the sensitivity of natural frequency is presented.The numerical simulation results indicate that the design parameters have an impact on the frequency characteristics of the compliant mechanisms and the proposed method is more accurate and convenient for analyzing frequency characteristics.

  11. Plaque formation by Teschen disease virus and the effect of certain associated factors.

    Science.gov (United States)

    Dardiri, A H; Delay, P D

    1966-07-01

    A plaque assay method was developed for Teschen disease virus using primary pig kidney cultures in which neutral red stain was incorporated in the agar overlay medium. Certain factors associated with the plaque-forming ability of the virus were standardized. Cultures allowed to adsorb the virus for 45-60 minutes at 28 and 37 C, gave maximal plaque count. The virus infected the cellular layer through the agar medium. Plating efficiency of the virus was enhanced by using a small volume of inoculum. Addition of serum to the medium was not required. Neutral red concentration in the agar overlay medium affected the number of plaques. Statistical analysis demonstrated the uniformity of the plaque counts and their linear relationship to virus concentration. Isolation of the virus by the plaque technique from infected spinal cord supernatant fluid was achieved.

  12. Red autofluorescence of dental plaque bacteria

    NARCIS (Netherlands)

    van der Veen, M. H.; Thomas, R. Z.; Huysmans, M. C. D. N. J. M.; de Soet, J. J.

    2006-01-01

    Red autofluorescence of plaque and its relation to fluorescence of a single species in the biofilm was studied. Fluorescence images of non-disclosed and disclosed plaque of 28 first-year students were captured. The plaque samples were assessed by culture methods and studied for red autofluorescence.

  13. Unified theory on the pathogenesis of Randall's plaques and plugs.

    Science.gov (United States)

    Khan, Saeed R; Canales, Benjamin K

    2015-01-01

    Kidney stones develop attached to sub-epithelial plaques of calcium phosphate (CaP) crystals (termed Randall's plaque) and/or form as a result of occlusion of the openings of the Ducts of Bellini by stone-forming crystals (Randall's plugs). These plaques and plugs eventually extrude into the urinary space, acting as a nidus for crystal overgrowth and stone formation. To better understand these regulatory mechanisms and the pathophysiology of idiopathic calcium stone disease, this review provides in-depth descriptions of the morphology and potential origins of these plaques and plugs, summarizes existing animal models of renal papillary interstitial deposits, and describes factors that are believed to regulate plaque formation and calcium overgrowth. Based on evidence provided within this review and from the vascular calcification literature, we propose a "unified" theory of plaque formation-one similar to pathological biomineralization observed elsewhere in the body. Abnormal urinary conditions (hypercalciuria, hyperoxaluria, and hypocitraturia), renal stress or trauma, and perhaps even the normal aging process lead to transformation of renal epithelial cells into an osteoblastic phenotype. With this de-differentiation comes an increased production of bone-specific proteins (i.e., osteopontin), a reduction in crystallization inhibitors (such as fetuin and matrix Gla protein), and creation of matrix vesicles, which support nucleation of CaP crystals. These small deposits promote aggregation and calcification of surrounding collagen. Mineralization continues by calcification of membranous cellular degradation products and other fibers until the plaque reaches the papillary epithelium. Through the activity of matrix metalloproteinases or perhaps by brute physical force produced by the large sub-epithelial crystalline mass, the surface is breached and further stone growth occurs by organic matrix-associated nucleation of CaOx or by the transformation of the outer layer

  14. A randomized controlled clinical trial of Ocimum sanctum and chlorhexidine mouthwash on dental plaque and gingival inflammation

    Directory of Open Access Journals (Sweden)

    Devanand Gupta

    2014-01-01

    Full Text Available Background: Periodontal diseases are ubiquitous, affecting all dentate animals. Regular methods for controlling it have been found to be ineffective, which have paved the way for the use of herbal products as an adjunctive to mechanical therapy as they are free to untoward effects and hence can be used for a long period of time. Ocimum sanctum is a plant which has the greater medicinal value and enormous properties for curing and preventing disease. Objective: In the present study we assessed the effectiveness of Ocimum sanctum on dental plaque, gingival inflammation and comparison with gold standard chlorhexidine and normal saline (placebo. Materials and Methods: A triple blind randomized control trial was conducted among volunteered medical students. They were randomly allocated into three study groups: (1 Ocimum sanctum mouthwash (n = 36; (2 Chlorhexidine (active control (n = 36; (3 normal saline (negative control (n = 36. Assessment was carried out according to plaque score and gingival score. Statistical analysis was carried out later to compare the effect of both mouthwash. ANOVA (Analysis of variance and post-hoc LSD tests were performed using software package used for statistical analysis (SPSS version 17. P ≤0.05 was considered as statistically significant. Results: Our result showed that Ocimum sanctum mouthrinse is equally effective in reducing plaque and gingivitis as Chlorhexidine. The results demonstrated a significant reduction in gingival bleeding and plaque indices in both groups over a period of 15 and 30 days as compared to control group. Conclusion: The results of the present study indicate that Ocimum sanctum mouthrinse may prove to be an effective mouthwash owing to its ability in decreasing periodontal indices by reducing plaque accumulation, gingival inflammation and bleeding. It has no side effect as compared to chlorhexidine.

  15. Protein components in saliva and plaque fluid from irradiated primates

    Energy Technology Data Exchange (ETDEWEB)

    Edgar, W.M.; Bowen, W.H.; Cole, M.F. (Caries Prevention and Research Branch, National Caries Program, NIDR, Bethesda, Maryland, USA)

    1982-01-01

    Irradiation of the major salivary glands of monkeys (Macaca mulatta) fed cariogenic diets leads to caries clinically indistinguishable from radiation caries in man. This study compares the organic compostion of individual samples of plaque fluid and saliva from irradiated and control monkeys receiving the same cariogenic diet. Plaque and saliva were collected from fasting, tranquillised animals. Four irradiated animals were sampled repeatedly as were non-irradiated controls. Total protein, albumin, immunoglobulins A, G, and M, and the third component of complement (C'3) were quantitated in plaque fluid and whole saliva. Salivary amylase and peroxidase activities were also determined. Plaque fluid and saliva samples were also subjected to polyacrylamide gel electrophoresis. The total viable anaerobic count and numbers of Streptococcus mutans were determined in samples of plaque. The results suggest that the major effect of irradiation leading to increased numbers of S. mutans and caries susceptibility is in the amount, and not the composition, of the saliva produced by the residual gland tissue. The scanty flow of saliva may reduce the effectiveness of cleansing, buffering and lubrication mechanisms as well as resulting in a marked reduction in the total amount of specific and non-specific immune factors entering the mouth.

  16. Apremilast for the management of moderate to severe plaque psoriasis.

    Science.gov (United States)

    Vangipuram, Ramya; Alikhan, Ali

    2017-04-01

    Psoriasis is a chronic inflammatory skin disease characterized by erythematous plaques on extensor surfaces, scalp, and back. Current therapies for psoriasis are limited by route of administration, side effects, and cost. Apremilast is the first oral phosphodiesterase inhibitor approved for moderate-to-severe plaque psoriasis. It is a small molecule inhibitor of phosphodiesterase-4, and decreases the inflammatory activity associated with psoriasis. Areas covered: This review will discuss the pharmacology of apremilast, mechanism of action, results from key clinical trials, and its use in managing psoriasis. Currently approved treatments are also discussed. Expert commentary: The advantages of apremilast include convenient oral administration and dosing, a favorable safety and tolerability profile, and significant efficacy in moderate-to-severe plaque psoriasis.

  17. Effectiveness of Azadirachta indica (neem) mouthrinse in plaque and gingivitis control: a systematic review.

    Science.gov (United States)

    Dhingra, K; Vandana, K L

    2017-02-01

    The aim of this systematic review was to evaluate the effectiveness of Azadirachta indica (neem)-based herbal mouthrinse in improving plaque control and gingival health. Literature search was accomplished using electronic databases (PubMed, Cochrane Central Register of Controlled Trials and EMBASE) and manual searching, up to February 2015, for randomized controlled trials (RCTs) presenting clinical data for efficacy of neem mouthrinses when used alone or as an adjunct to mechanical oral hygiene as compared to chlorhexidine mouthrinses for controlling plaque and gingival inflammation in patients with gingivitis. Of the total 206 articles searched, three randomized controlled trials evaluating neem-based herbal mouthrinses were included. Due to marked heterogeneity observed in study characteristics, meta-analysis was not performed. These studies reported that neem mouthrinse was as effective as chlorhexidine mouthrinse when used as an adjunct to toothbrushing in reducing plaque and gingival inflammation in gingivitis patients. However, the quality of reporting and evidence along with methods of studies was generally flawed with unclear risk of bias. Despite the promising results shown in existing randomized controlled trials, the evidence concerning the clinical use of neem mouthrinses is lacking and needs further reinforcement with high-quality randomized controlled trials based on the reporting guidelines of herbal CONSORT statement. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Quantitative analysis of textures produced in a hot-extruded zirconium plate; Analyse quantitative des textures developpees dans une plaque de zirconium filee a chaud

    Energy Technology Data Exchange (ETDEWEB)

    Couterne, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Institut national des sciences et techniques nucleaires, laboratoire de metallurgie

    1967-01-01

    The textures produced in zirconium by the extrusion at 730 deg C of a cylindrical billet in the form of a plate having a rectangular cross-section, have been studied by the Schulz method using an isotropic standard. These textures have been determined both parallel to the plane of the plate and parallel to the plane of the sides, All the results are analyzed in a final discussion which makes it possible to show, in particular near the edges of the plate, that certain components of the textures observed in the two series of recordings are in fact aspects of the same texture seen from two different angles, It is shown furthermore that the zirconium thus shaped has cold-work textures and als recrystallisation textures formed after the preceding cold-working, If the observed textures are considered schematically, it can be see that two of these have already been described in the literature and are similar to those found in rolled products: these textures are such that the (0001) planes are inclined at 36 deg C and 60 deg C respectively with respect to a plan tangential to the curve (envelope of transverse flow rates) resulting from the extrusion geometry under consideration; the third texture is defined. by the fact that the (0001) plane is orthogonal to the exterior surfaces of the plate. The direction of extrusion associated with these planes and common to the three textures is of the type <1010>, Dilatometric tests have been carried out on samples taken both parallel and perpendicular to the extrusion direction, These tests show that the zirconium is dilatometrically anisotropic and that a plot of ({alpha}{sub v})-a against temperature shows a change of gradient at 400 deg C, this latter effect may be due to the change in the electronic configuration of the metal occurring at this temperature. (author) [French] Les textures conferees au zirconium par filage a chaud a 730 deg C d'une billette cylindrique sous forme d'une plaque de section rectangulaire, ont

  19. A randomized clinical study for comparative evaluation of Aloe Vera and 0.2% chlorhexidine gluconate mouthwash efficacy on de-novo plaque formation

    Science.gov (United States)

    Chhina, Shivjot; Singh, Avnish; Menon, Ipseeta; Singh, Rickypal; Sharma, Anubhav; Aggarwal, Vartika

    2016-01-01

    Objective: To comparatively assess the antiplaque efficacy of Aloe vera mouthwash and 0.2% chlorhexidine gluconate mouthwash on de novo plaque formation. Materials and Methods: This was a randomized, single blind, parallel, controlled clinical study with 90 healthy participants, with mean age of 27.19 ± 12.08 years. After thorough oral prophylaxis, participants were instructed to discontinue mechanical plaque control. Participants were divided randomly into three groups; pure Aloe vera mouthwash was dispensed to the test group; control group received 0.2% chlorhexidine gluconate mouthwash; in Placebo group, flavored distilled water was used as oral rinse twice daily. Effect on 4-day de novo plaque formation was assessed by comparing pre-rinsing Quigley Hein Modified Plaque Scores were analyzed statistically using analysis of variance and Student's t-test. Results: Post-rinsing control group showed the least plaque score which was comparable to the test group. Both the control group and test group showed significant difference with the placebo group. Conclusions: Herbal mouthwash containing Aloe vera mouthwash has comparable antiplaque efficacy as the gold standard 0.2% chlorhexidine gluconate with fewer side effects and can be considered as an alternative. PMID:27382543

  20. The molecular concept of atheromatous plaques.

    Science.gov (United States)

    Thent, Zar Chi; Chakraborty, Chiranjib; Mahakkanukrauh, Pasuk; Kosai, Nik; Rajan, Reynu; Das, Srijit

    2016-05-02

    Recently, there are scientific attempts to devise new drugs in the biotechnology industry in order to treat various diseases including atherosclerosis. Atherosclerosis is considered to be a leading cause of death throughout the world. Atherosclerosis involves oxidative damage to the cells with production of reactive oxygen species (ROS). Development of atheromatous plaques in the arterial wall is a common feature. Specific inflammatory markers pertaining to the arterial wall in atherosclerosis may be useful for both diagnosis and treatment. These include macrophage inhibiting factor (MIF), leucocytes and P-selectin. Modern therapeutic paradigms involving endothelial progenitor cells therapy, angiotensin II type-2 (AT2R) and ATP-activated purinergic receptor therapy are notable to mention. Future drugs may be designed aiming three signalling mechanisms of AT2R which are (a) activation of protein phosphatases resulting in protein dephosphorylation (b) activation of bradykinin/nitric oxide/cyclic guanosine 3',5'-monophosphate pathway by vasodilation and (c) stimulation of phospholipase A(2) and release of arachidonic acid. Drugs may also be designed to act on ATP-activated purinergic receptor channel type P2X7 molecules which acts on cardiovascular system. In the present review, we discuss the molecular concept of the inflammatory process occurring inside the arterial wall. Better understanding of the vascular inflammatory processes and the cells involved in the formation of plaques, may prove to be beneficial for future diagnosis, clinical treatment and planning innovative novel anti-atherosclerotic drugs.

  1. Plaque array method and proteomics-based identification of biomarkers from Alzheimer's disease serum.

    Science.gov (United States)

    Madasamy, Shanmugavel; Chaudhuri, Vaishali; Kong, Raymond; Alderete, Benjamin; Adams, Christopher M; Knaak, Tim D; Ruan, Weiming; Wu, Alan H B; Bigos, Marty; Amento, Edward P

    2015-02-20

    Progressive accumulation of amyloid plaques in the regions of brain, carotid and cerebral arteries is the leading cause of Alzheimer's disease (AD) and related dementia in affected patients. The early identification of individuals with AD remains a challenging task relying on symptomatic events and thus the development of a biomarker-based approach will significantly aid in the diagnosis of AD. Here we describe a flow cytometer-based serum biomarker identification method using plaque particles, and applying mass spectrometry based proteomic analysis of the isolated plaque particles for the identification of serum proteins present in the plaque particles. We identified 195 serum proteins that participate in the process of plaque particle formation. Among the 195 proteins identified, 68.2% of them overlapped in abeta-42, cholesterol, tau-275 and α-synuclein plaque particles. Significantly, 22.5% of the proteins identified as bound to abeta-42 plaque particles generated in AD serum were unique when compared with cholesterol, α-synuclein and tau plaque particles. In age-matched control experiments, 15% of them showed in vitro insoluble abeta-42 particle formation and 59% of the identified plaque particle constituents from AD serum were also present in the insoluble plaque particles derived from control. We have developed an in vitro method for plaque particle detection and identified serum protein markers that are associated with AD-related plaque particle formation. With further clinical validation, this assay may provide a novel, non-invasive means for the early detection of AD. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. A mechanical energy analysis of gait initiation

    Science.gov (United States)

    Miller, C. A.; Verstraete, M. C.

    1999-01-01

    The analysis of gait initiation (the transient state between standing and walking) is an important diagnostic tool to study pathologic gait and to evaluate prosthetic devices. While past studies have quantified mechanical energy of the body during steady-state gait, to date no one has computed the mechanical energy of the body during gait initiation. In this study, gait initiation in seven normal male subjects was studied using a mechanical energy analysis to compute total body energy. The data showed three separate states: quiet standing, gait initiation, and steady-state gait. During gait initiation, the trends in the energy data for the individual segments were similar to those seen during steady-state gait (and in Winter DA, Quanbury AO, Reimer GD. Analysis of instantaneous energy of normal gait. J Biochem 1976;9:253-257), but diminished in amplitude. However, these amplitudes increased to those seen in steady-state during the gait initiation event (GIE), with the greatest increase occurring in the second step due to the push-off of the foundation leg. The baseline level of mechanical energy was due to the potential energy of the individual segments, while the cyclic nature of the data was indicative of the kinetic energy of the particular leg in swing phase during that step. The data presented showed differences in energy trends during gait initiation from those of steady state, thereby demonstrating the importance of this event in the study of locomotion.

  3. Multimodal spectroscopy detects features of vulnerable atherosclerotic plaque

    Science.gov (United States)

    Šćepanović, Obrad R.; Fitzmaurice, Maryann; Miller, Arnold; Kong, Chae-Ryon; Volynskaya, Zoya; Dasari, Ramachandra R.; Kramer, John R.; Feld, Michael S.

    2011-01-01

    Early detection and treatment of rupture-prone vulnerable atherosclerotic plaques is critical to reducing patient mortality associated with cardiovascular disease. The combination of reflectance, fluorescence, and Raman spectroscopy-termed multimodal spectroscopy (MMS)-provides detailed biochemical information about tissue and can detect vulnerable plaque features: thin fibrous cap (TFC), necrotic core (NC), superficial foam cells (SFC), and thrombus. Ex vivo MMS spectra are collected from 12 patients that underwent carotid endarterectomy or femoral bypass surgery. Data are collected by means of a unitary MMS optical fiber probe and a portable clinical instrument. Blinded histopathological analysis is used to assess the vulnerability of each spectrally evaluated artery lesion. Modeling of the ex vivo MMS spectra produce objective parameters that correlate with the presence of vulnerable plaque features: TFC with fluorescence parameters indicative of collagen presence; NC/SFC with a combination of diffuse reflectance β-carotene/ceroid absorption and the Raman spectral signature of lipids; and thrombus with its Raman signature. Using these parameters, suspected vulnerable plaques can be detected with a sensitivity of 96% and specificity of 72%. These encouraging results warrant the continued development of MMS as a catheter-based clinical diagnostic technique for early detection of vulnerable plaques.

  4. Restriction of bacteriophage plaque formation in Streptomyces spp.

    Science.gov (United States)

    Cox, K L; Baltz, R H

    1984-08-01

    Several Streptomyces species that produce restriction endonucleases were characterized for their ability to propagate 10 different broad host range bacteriophages. Each species displayed a different pattern of plaque formation. A restrictionless mutant of S. albus G allowed plaque formation by all 10 phages, whereas the wild-type strain showed plaques with only 2 phages. DNA isolated from three of the phages was analyzed for the presence of restriction sites for Streptomyces species-encoded enzymes, and a very strong correlation was established between the failure to form plaques on Streptomyces species that produced particular restriction enzymes and the presence of the corresponding restriction sites in the phage DNA. Also, the phages that lacked restriction sites in their DNA generally formed plaques on the corresponding restriction endonuclease-producing hosts at high efficiency. The DNAs from the three phages analyzed also generally contained either many or no restriction sites for the Streptomyces species-produced enzymes, suggesting a strong evolutionary trend to either eliminate all or tolerate many restriction sites. The data indicate that restriction plays a major role in host range determination for Streptomyces phages. Analysis of bacteriophage host ranges of many other uncharacterized Streptomyces hosts has identified four relatively nonrestricting hosts, at least two of which may be suitable hosts for gene cloning. The data also suggest that several restriction systems remain to be identified in the genus Streptomyces.

  5. Arsenic rich iron plaque on macrophyte roots - an ecotoxicological risk?

    Energy Technology Data Exchange (ETDEWEB)

    Taggart, M.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom); Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain)], E-mail: mark.taggart@uclm.es; Mateo, R. [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain); Charnock, J.M.; Bahrami, F. [Synchrotron Radiation Department, CCLRC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Green, A.J. [Department of Wetland Ecology, Estacion Biologica de Donana, CSIC, Pabellon del Peru, Avenida Maria Luisa s/n, 41013 Seville (Spain); Meharg, A.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom)

    2009-03-15

    Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcollar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed 'root + plaque' material in excess of 1000 mg kg{sup -1}, and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcollar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque. - Accumulation of metals with iron plaque on macrophyte roots in wetlands poses an ecotoxicological risk to certain herbivores.

  6. The Distribution of Macrophages and the Mechanism of Macrophages Accumulation in Atheroscle-rotic Plaques%动脉粥样硬化斑块中巨噬细胞的分布与蓄积机制

    Institute of Scientific and Technical Information of China (English)

    王林青; 李全忠; 钱宗杰

    2016-01-01

    动脉粥样硬化斑块破裂可导致严重的临床事件(如心肌梗死和脑卒中)。巨噬细胞是动脉粥样硬化斑块内最主要的炎性细胞,它可根据不同的微环境分化成不同表型的巨噬细胞。其中, M1型巨噬细胞主要位于斑块不稳定区,M2型巨噬细胞主要位于斑块的稳定区。随着动脉粥样硬化斑块的进展,斑块内积聚的巨噬细胞逐渐增多,而斑块内不断蓄积的巨噬细胞主要依赖于局部巨噬细胞的增殖,而不是血中单核细胞的分化。%The rupture of atherosclerotic plaque can lead to severe consequences, such as myocardial infraction and stroke.Macrophages are the predominant inflammatory cells within the plaques,which are very versatile and can polarize different phenotypes depending on the local microenvironment .M1 macrophages are exclusively found in unstable plaques and M2 macrophages being higher in stable plaques.The incremental accumulation of macrophages corresponded with plaque progression,are mainly derived from local prolifera-tion rather than from the influx of blood-borne monocytes.

  7. Three-Dimensional Carotid Plaque Progression Simulation Using Meshless Generalized Finite Difference Method Based on Multi-Year MRI Patient-Tracking Data.

    Science.gov (United States)

    Yang, Chun; Tang, Dalin; Atluri, Satya

    2010-01-01

    Cardiovascular disease (CVD) is becoming the number one cause of death worldwide. Atherosclerotic plaque rupture and progression are closely related to most severe cardiovascular syndromes such as heart attack and stroke. Mechanisms governing plaque rupture and progression are not well understood. A computational procedure based on three-dimensional meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating patients were scanned three times (T1, T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Since there was insufficient data with the current technology to quantify individual plaque component growth, the whole plaque was assumed to be uniform, homogeneous, isotropic, linear, and nearly incompressible. The linear elastic model was used. The 3D plaque model was discretized and solved using a meshless generalized finite difference (GFD) method. Four growth functions with different combinations of wall thickness, stress, and neighboring point terms were introduced to predict future plaque growth based on previous time point data. Starting from the T2 plaque geometry, plaque progression was simulated by solving the solid model and adjusting wall thickness using plaque growth functions iteratively until T3 is reached. Numerically simulated plaque progression agreed very well with the target T3 plaque geometry with errors ranging from 11.56%, 6.39%, 8.24%, to 4.45%, given by the four growth functions. We believe this is the first time 3D plaque progression simulation based on multi-year patient-tracking data was reported. Serial MRI-based progression simulation adds time dimension to plaque vulnerability assessment and will improve prediction accuracy for potential plaque rupture

  8. Radiation regression patterns after cobalt plaque insertion for retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Buys, R.J.; Abramson, D.H.; Ellsworth, R.M.; Haik, B.

    1983-08-01

    An analysis of 31 eyes of 30 patients who had been treated with cobalt plaques for retinoblastoma disclosed that a type I radiation regression pattern developed in 15 patients; type II, in one patient, and type III, in five patients. Nine patients had a regression pattern characterized by complete destruction of the tumor, the surrounding choroid, and all of the vessels in the area into which the plaque was inserted. This resulting white scar, corresponding to the sclerae only, was classified as a type IV radiation regression pattern. There was no evidence of tumor recurrence in patients with type IV regression patterns, with an average follow-up of 6.5 years, after receiving cobalt plaque therapy. Twenty-nine of these 30 patients had been unsuccessfully treated with at least one other modality (ie, light coagulation, cryotherapy, external beam radiation, or chemotherapy).

  9. Vulnerable Plaques, Inflammation and Newer Imaging Modalities

    Directory of Open Access Journals (Sweden)

    Bhatia V

    2003-01-01

    Full Text Available Currently, inflammation is considered to be the central player in the pathogenesis of atherosclerosis. It leads to the formation of multiple plaques in the arterial beds including coronary vasculature. Recent studies using the latest imaging techniques have shown that in patients with acute coronary syndromes (ACS multiple plaques are ruptured and have thrombus formation on them. Various factors make these plaques unstable, these include structural components of plaque like thin fibrous cap, high lipid content of the plaque core and inflammation, both localized and generalized. It has been shown that most of the ACS are caused by plaques causing non-critical stenosis as seen on traditional X-ray angiography. Also, the phenomenon of remodelling makes angiography a poor technique for plaque visualization. Hence newer modalities are required to identify these 'vulnerable plaques'. Intravascular ultrasound (IVUS, thermography and Magnetic Resonance Imaging (MRI are a few such promising techniques. Here we review the invasive and non-invasive modalities that can be helpful in the identification of these plaques before they become unstable and cause ACS, and also the available therapies to stabilize these plaques.

  10. Pathogenicity of human high pathogenic H5N1 virus with different plaque property

    Directory of Open Access Journals (Sweden)

    Yong-qiang LI

    2011-06-01

    Full Text Available Objective To determine the pathogenicity of human high pathogenic H5N1 virus with different plaque property,and provide a new train of thought and basis for research on crossing species-genus transmission of avian influenza virus.Methods Variants with different plaque property(larger-and smaller-plaque variant were isolated from A/Beijing/01/03(H5N1(BJ01 by the plaque purification.Mice were inoculated intranasally(i.n. with each kind of isolated variant and monitored for 14 days to record and calculate the body weight change and the survival rate.The difference in pathogenicity of isolated variants was estimated with proper principle of statistics.Results The plaques of original strain of BJ01 virus were heterogeneous with various size and shape.Larger-plaque variants(L1 and L2 and smaller-plaque variants(S1,S2 and S3 were isolated separately.The pathogenicity was higher in S1 and S2 variants than in S3,L1 and L2 variants,and that of L2 variant was the lowest.Variants forming different plaques were heterogeneous in pathogenicity,and those forming same plaques were also heterogeneous in pathogenicity.Conclusion There is no linear correlation between the pathogenicity of variants and the size of plaque they formed.The variants with different pathogenicity could be isolated from the same H5N1 virus strain by plaque purification.These results would provide a basis for vaccine development and the studies on molecular mechanism of H5N1 virus.

  11. Lectin Pathway of Complement Activation Is Associated with Vulnerability of Atherosclerotic Plaques

    Science.gov (United States)

    Fumagalli, Stefano; Perego, Carlo; Zangari, Rosalia; De Blasio, Daiana; Oggioni, Marco; De Nigris, Francesca; Snider, Francesco; Garred, Peter; Ferrante, Angela M. R.; De Simoni, Maria-Grazia

    2017-01-01

    Inflammatory mechanisms may be involved in atherosclerotic plaque rupture. By using a novel histology-based method to quantify plaque instability here, we assess whether lectin pathway (LP) of complement activation, a major inflammation arm, could represent an index of plaque instability. Plaques from 42 consecutive patients undergoing carotid endarterectomy were stained with hematoxylin-eosin and the lipid core, cholesterol clefts, hemorrhagic content, thickness of tunica media, and intima, including or not infiltration of cellular debris and cholesterol, were determined. The presence of ficolin-1, -2, and -3 and mannose-binding lectin (MBL), LP initiators, was assessed in the plaques by immunofluorescence and in plasma by ELISA. LP activation was assessed in plasma by functional in vitro assays. Patients presenting low stenosis (≤75%) had higher hemorrhagic content than those with high stenosis (>75%), indicating increased erosion. Increased hemorrhagic content and tunica media thickness, as well as decreased lipid core and infiltrated content were associated with vulnerable plaques and therefore used to establish a plaque vulnerability score that allowed to classify patients according to plaque vulnerability. Ficolins and MBL were found both in plaques’ necrotic core and tunica media. Patients with vulnerable plaques showed decreased plasma levels and intraplaque deposition of ficolin-2. Symptomatic patients experiencing a transient ischemic attack had lower plasma levels of ficolin-1. We show that the LP initiators are present within the plaques and their circulating levels change in atherosclerotic patients. In particular, we show that decreased ficolin-2 levels are associated with rupture-prone vulnerable plaques, indicating its potential use as marker for cardiovascular risk assessment in atherosclerotic patients. PMID:28360913

  12. In silico analyses of metagenomes from human atherosclerotic plaque samples

    DEFF Research Database (Denmark)

    Mitra, Suparna; Drautz-Moses, Daniela I; Alhede, Morten

    2015-01-01

    a challenge. RESULTS: To investigate microbiome diversity within human atherosclerotic tissue samples, we employed high-throughput metagenomic analysis on: (1) atherosclerotic plaques obtained from a group of patients who underwent endarterectomy due to recent transient cerebral ischemia or stroke. (2...

  13. Volumetric Examination of MS Plaques and Correlation with EDSS Ratings.

    Science.gov (United States)

    Gurwara, S; Hailey, B; Thompson, A; Minagar, A; Hardjasudarma, M; Gonzalez-Toledo, E

    2009-05-15

    This study is a retrospective analysis of 17 patients with multiple sclerosis. The total volume of plaques from three different MR image sets of the brain was correlated with the EDSS ratings of the patients. Each of the correlations showed a positive relationship, but none was statistically significant. A more extensive study is required in order to give significance to these relationships.

  14. Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro

    NARCIS (Netherlands)

    C.L. de Korte (Chris); G. Pasterkamp (Gerard); H.A. Woutman; N. Bom (Klaas); A.F.W. van der Steen (Ton)

    2000-01-01

    textabstractBACKGROUND: The composition of plaque is a major determinant of coronary-related clinical syndromes. Intravascular ultrasound (IVUS) elastography has proven to be a technique capable of reflecting the mechanical properties of phantom material and the femoral arterial

  15. Evaluation of antiplaque and antigingivitis effect of herbal mouthwash in treatment of plaque induced gingivitis: A randomized, clinical trial

    Directory of Open Access Journals (Sweden)

    Shivanand Aspalli

    2014-01-01

    Full Text Available Background: Ayurvedic drugs have been used since ancient times to treat diseases including periodontal diseases. Oral rinses made from ayurvedic medicines are used in periodontal therapy to control bleeding and reduce inflammation. The aim of this clinical study is to verify the efficacy of herbal mouthwash containing Pilu, Bibhitaka, Nagavalli, Gandhapura taila, Ela, Peppermint satva, and Yavani satva on reduction of plaque and gingivitis. Materials and Methods: A total of 100 volunteers with clinical signs of mild to moderate gingivitis were selected and assigned to Group A (only scaling done and Group B (scaling along with the use of herbal mouthwash. After recording the clinical parameters, the patients were instructed to use herbal mouthwash 15 ml for 30 s twice daily after food in Group B and oral hygiene instructions were given to all patients. Plaque and gingivitis assessment were carried out using the plaque index (Silness nd Loe, 1964, Gingival index (Loe And Silness, 1963, Gingival bleeding index (Ainamo and Bay, 1975 at baseline and at 21 days of the herbal mouthwash use. Statistically analysis was carried out using the student′s t-test for normally distributed data and Wilcoxson test or Mann-Whitney U-test for skewed data. Results: Our results showed that herbal mouthwash was effective in treatment of plaque induced gingivitis in Group B when compared with the Group A. Conclusion: Herbal mouthwash is effective in treatment of plaque induced gingivitis and can be effectively used as an adjunct to mechanical therapy with lesser side-effects.

  16. Fluorescent activated cell sorting: an effective approach to study dendritic cell subsets in human atherosclerotic plaques.

    Science.gov (United States)

    Van Brussel, Ilse; Ammi, Rachid; Rombouts, Miche; Cools, Nathalie; Vercauteren, Sven R; De Roover, Dominique; Hendriks, Jeroen M H; Lauwers, Patrick; Van Schil, Paul E; Schrijvers, Dorien M

    2015-02-01

    Different immune cell types are present within atherosclerotic plaques. Dendritic cells (DC) are of special interest, since they are considered as the 'center of the immuniverse'. Identifying inflammatory DC subtypes within plaques is important for a better understanding of the lesion pathogenesis and pinpoints their contribution to the atherosclerotic process. We have developed a flow cytometry-based method to characterize and isolate different DC subsets (i.e. CD11b(+), Clec9A(+) and CD16(+) conventional (c)DC and CD123(+) plasmacytoid (p)DC) in human atherosclerotic plaques. We revealed a predominance of pro-inflammatory CD11b(+) DC in advanced human lesions, whereas atheroprotective Clec9A(+) DC were almost absent. CD123(+) pDC and CD16(+) DC were also detectable in plaques. Remarkably, plaques from distinct anatomical locations exhibited different cellular compositions: femoral plaques contained less CD11b(+) and Clec9A(+) DC than carotid plaques. Twice as many monocytes/macrophages were observed compared to DC. Moreover, relative amounts of T cells/B cells/NK cells were 6 times as high as DC numbers. For the first time, fluorescent activated cell sorting analysis of DC subsets in human plaques indicated a predominance of CD11b(+) cDC, in comparison with other DC subsets. Isolation of the different subsets will facilitate detailed functional analysis and may have significant implications for tailoring appropriate therapy.

  17. Correlation between Plaque Composition as assessed by Virtual Histology and C-reactive Protein

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Dimytri Alexandre de Alvim, E-mail: dimytri@cardiol.br; Sousa, Amanda Guerra Moraes R.; Costa Junior, José de Ribamar; Costa, Ricardo Alves da; Staico, Rodolfo; Tanajura, Luis Fernando Leite; Centemero, Marinella Patrizia; Feres, Fausto; Abizaid, Alexandre Antonio Cunha; Sousa, J. Eduardo Moraes R. [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

    2013-07-15

    Previous studies have shown that coronary plaque composition plays a pivotal role in plaque instability, and imaging modalities and serum biomarkers have been investigated to identify vulnerable plaque. Virtual histology IVUS (VH-IVUS) characterizes plaque components as calcified, fibrotic, fibrofatty, or necrotic core. C-reactive protein (hsCRP) is an independent risk factor and a powerful predictor of future coronary events. However, a relationship between inflammatory response indicated by CRP and plaque characteristics in ACS patients remains not well established. To determine, by using VH-IVUS, the relation between coronary plaque components and plasma high-sensitivity CRP levels in patients with acute coronary syndromes (ACS). 52 patients with ACS were enrolled in this prospective study. Electrocardiographically-gated VH-IVUS were performed in the culprit lesion before PCI. Blood sample was drawn from all patients before the procedure and after 24 hours, and hs-CRP levels were determined. Mean age was 55.3±4.9 years, 76.9% were men and 30.9% had diabetes. Mean MLA was 3.9±1.3 mm{sup 2}, and plaque burden was 69±11.3%, as assessed by IVUS. VH-IVUS analysis at the minimum luminal site identified plaque components: fibrotic (59.6±15.8%), fibrofatty (7.6±8.2%), dense calcium (12.1±9.2%) and necrotic core (20.7±12.7%). Plasma hs-CRP (mean 16.02±18.07 mg/L) did not correlate with necrotic core (r=-0.089, p = 0.53) and other plaque components. In this prospective study with patients with ACS, the predominant components of the culprit plaque were fibrotic and necrotic core. Serum hs C-reactive protein levels did not correlate with plaque composition.

  18. Enhancement patterns in the fibro cellular tissue in different kinds of plaques of the internal carotid artery

    Energy Technology Data Exchange (ETDEWEB)

    Rantner, Barbara, E-mail: barbara.rantner@i-med.ac.at [Department of Vascular Surgery, Innsbruck Medical University, Innsbruck (Austria); Sojer, Martin, E-mail: martin.sojer@uki.at [Department of Neurology, Innsbruck Medical University, Innsbruck (Austria); Kremser, Christian, E-mail: christian.kremser@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Innsbruck (Austria); Cartes-Zumelzu, Fabiola, E-mail: fabiola.cartes-zumelzu@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Innsbruck (Austria); Fraedrich, Gustav, E-mail: gustav.fraedrich@i-med.ac.at [Department of Vascular Surgery, Innsbruck Medical University, Innsbruck (Austria); Jaschke, Werner, E-mail: Werner.jaschke@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Innsbruck (Austria); Chemelli-Steingruber, Iris, E-mail: iris.chemelli.steingruber@gmail.com [Department of Radiology, Innsbruck Medical University, Innsbruck (Austria)

    2013-11-01

    Background: The differentiation between stable and vulnerable plaques in the internal carotid artery (ICA) remains a matter of interest. With the implementation of contrast agent in magnetic resonance imaging (MRI) a more detailed plaque characterization is possible. The study at hand focuses on enhancement patterns of fibro cellular tissue in different kinds of plaques in the ICA. Methods: Between May 2011 and December 2012, 49 patients (39 male) with >50% stenosis of the ICA were consecutively enrolled. In 10 patients with bilateral ICA stenosis, both plaques were included for analysis. We performed a classification of plaques according to Cai and observed 11 type 4–5 plaques, 15 type 6 plaques and 33 type 8 plaques. MRI was performed on a 3 T whole body MR system. The standard 12 channel head coil was combined with the neck extension coil and two bilateral 7 cm loop coils. Post-contrast T1w images were subtracted from pre contrast images to identify late enhancement in fibro cellular tissue. Enhancement patterns were allocated as intraluminal, intraplaque and vasa vasorum enhancement in different types of plaques. Results: Fibro cellular tissue always exhibited a higher contrast enhancement compared to the sternocleidomastoid muscle. This reflects a higher grade of vascularization of the fibrocellular tissue. Contrast enhancement was present irrespective of the plaque type. In detail, intraluminal, intraplaque and vasa vasorum enhancement were observed in all types of plaques. Even type 8 plaques, according to the classification of Cai, had a significant contrast enhancement, though supposed to be with low inflammatory activity. Conclusion: Type 8 plaques might not be as stable as postulated. Whether the relevant uptake of contrast agent is due to the fibrous tissue or reflects the inflammatory activity of the plaque should be matter of further investigations.

  19. ANALYSIS OF MECHANISMS FINANCING OF CULTURAL SPHERE

    Directory of Open Access Journals (Sweden)

    Costandachi Gheorghe

    2008-01-01

    Full Text Available In this work is made analysis concern basically state structures of culture and arts activities, is describes the problems are met during the reforming process the financial mechanisms in cultural sphere. Author disclosed the ways evolve private and estate financing cultural sphere, also is disclosed why is need estate financial support. The work contains something detailed measures actions to improve financial and mechanisms financing of cultural sphere. Analyzing questions of modernization of budgetary financing of branch the author have formulated effectiveness of use of budgetary funds at all levels in cultural structures and proposed the ways of finishing of market reforms in cinematography. In the final of work is presented scheme system of financing, formation and distribution of financial resources in cinematography and is making conclusions and is offered wais of the solutions created present situation in this sphere in Moldova.

  20. Analysis on mechanism of thin film lubrication

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chaohui; LUO Jianbin; HUANG Zhiqiang

    2005-01-01

    It is an important concern to explore the properties and principles of lubrication at nano or molecularscale. For a long time, measurement apparatus for filmthickness of thin film lubrication (TFL) at nano scale havebeen devised on the basis of superthin interferometry technique. Many experiments were carried out to study the lubrication principles of TFL by taking advantages of aforementioned techniques, in an attempt to unveil the mechanism of TFL. Comprehensive experiments were conducted to explore the distinctive characteristics of TFL. Results show that TFL is a distinctive lubrication state other than any known lubrication ones, and serves as a bridge between elastohydrodynamic lubrication (EHL) and boundary lubrication (BL). Two main influence factors of TFL are the solid surface effects and the molecular properties of the lubricant, whose combination effects result in alignment of liquid molecules near the solid surfaces and subsequently lubrication with ordered film emerged. Results of theoretical analysis considering microstructure are consistent with experimental outcomes, thus validating the proposed mechanism.

  1. Experiments and video analysis in classical mechanics

    CERN Document Server

    de Jesus, Vitor L B

    2017-01-01

    This book is an experimental physics textbook on classical mechanics focusing on the development of experimental skills by means of discussion of different aspects of the experimental setup and the assessment of common issues such as accuracy and graphical representation. The most important topics of an experimental physics course on mechanics are covered and the main concepts are explored in detail. Each chapter didactically connects the experiment and the theoretical models available to explain it. Real data from the proposed experiments are presented and a clear discussion over the theoretical models is given. Special attention is also dedicated to the experimental uncertainty of measurements and graphical representation of the results. In many of the experiments, the application of video analysis is proposed and compared with traditional methods.

  2. Scanning electron microscopy analysis of the growth of dental plaque on the surfaces of removable orthodontic aligners after the use of different cleaning methods

    Directory of Open Access Journals (Sweden)

    Levrini L

    2015-12-01

    Full Text Available Luca Levrini, Francesca Novara, Silvia Margherini, Camilla Tenconi, Mario Raspanti Department of Surgical and Morphological Sciences, Dental Hygiene School, Research Centre Cranio Facial Disease and Medicine, University of Insubria, Varese, Italy Background: Advances in orthodontics are leading to the use of minimally invasive technologies, such as transparent removable aligners, and are able to meet high demands in terms of performance and esthetics. However, the most correct method of cleaning these appliances, in order to minimize the effects of microbial colonization, remains to be determined. Purpose: The aim of the present study was to identify the most effective method of cleaning removable orthodontic aligners, analyzing the growth of dental plaque as observed under scanning electron microscopy. Methods: Twelve subjects were selected for the study. All were free from caries and periodontal disease and were candidates for orthodontic therapy with invisible orthodontic aligners. The trial had a duration of 6 weeks, divided into three 2-week stages, during which three sets of aligners were used. In each stage, the subjects were asked to use a different method of cleaning their aligners: 1 running water (control condition; 2 effervescent tablets containing sodium carbonate and sulfate crystals followed by brushing with a toothbrush; and 3 brushing alone (with a toothbrush and toothpaste. At the end of each 2-week stage, the surfaces of the aligners were analyzed under scanning electron microscopy. Results: The best results were obtained with brushing combined with the use of sodium carbonate and sulfate crystals; brushing alone gave slightly inferior results. Conclusion: On the basis of previous literature results relating to devices in resin, studies evaluating the reliability of domestic ultrasonic baths for domestic use should be encouraged. At present, pending the availability of experimental evidence, it can be suggested that dental

  3. Investigation Of Interaction Between Nitinol Stent And A Vascular Plaque Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Recep Güneş

    2012-06-01

    Full Text Available In this study, the interaction between the Nitinol stent and the artery with plaque was investigated using finite element method. The occurring pressure values during the cardiac contraction (systolic and loosening (diastolic were applied as loading to the modeled system with Nitinol stent. In the light of the stress values, the suitability of the Nitinol stent in an artery with plaque was investigated. In the analysis, Nitinol stent was assumed to be shape memory alloy, and artery and plaque were assumed to behave linearly elastic. As a result, the stress and deformations in the plaque and artery due to the interference of Nitinol stent were discussed and concluded that the structure of artery with plaque can be expanded in accordance with Nitinol stent.

  4. SIGNAL FLOW GRAPH ANALYSIS OF MECHANICAL ENGINEERING SYSTEMS

    Science.gov (United States)

    CONTROL SYSTEMS, *MECHANICS, *STRUCTURES, *THERMODYNAMICS, *TOPOLOGY, BEAMS(ELECTROMAGNETIC), BEAMS(STRUCTURAL), GAS FLOW, GEARS, HEAT EXCHANGERS, MATHEMATICAL ANALYSIS, MATHEMATICS, MECHANICAL ENGINEERING , RAMJET ENGINES.

  5. Current status of vulnerable plaque detection.

    LENUS (Irish Health Repository)

    Sharif, Faisal

    2012-02-01

    Critical coronary stenoses have been shown to contribute to only a minority of acute coronary syndromes (ACS) and sudden cardiac death. Autopsy studies have identified a subgroup of high-risk patients with disrupted vulnerable plaque and modest stenosis. Consequently, a clinical need exists to develop methods to identify these plaques prospectively before disruption and clinical expression of disease. Recent advances in invasive and noninvasive imaging techniques have shown the potential to identify these high-risk plaques. The anatomical characteristics of the vulnerable plaque such as thin cap fibroatheroma and lipid pool can be identified with angioscopy, high frequency intravascular ultrasound, intravascular MRI, and optical coherence tomography. Efforts have also been made to recognize active inflammation in high-risk plaques using intravascular thermography. Plaque chemical composition by measuring electromagnetic radiation using spectroscopy is also an emerging technology to detect vulnerable plaques. Noninvasive imaging with MRI, CT, and PET also holds the potential to differentiate between low and high-risk plaques. However, at present none of these imaging modalities are able to detect vulnerable plaque neither has been shown to definitively predict outcome. Nevertheless in contrast, there has been a parallel development in the physiological assessment of advanced atherosclerotic coronary artery disease. Thus recent trials using fractional flow reserve in patients with modest non flow-limiting stenoses have shown that deferral of PCI with optimal medical therapy in these patients is superior to coronary intervention. Further trials are needed to provide more information regarding the natural history of high-risk but non flow-limiting plaque to establish patient-specific targeted therapy and to refine plaque stabilizing strategies in the future.

  6. Numerical modelling of tooth enamel subsurface lesion formation induced by dental plaque.

    Science.gov (United States)

    Ilie, O; van Turnhout, A G; van Loosdrecht, M C M; Picioreanu, C

    2014-01-01

    Using a one-dimensional mathematical model that couples tooth demineralisation and remineralisation with metabolic processes occurring in the dental plaque, two mechanisms for subsurface lesion formation were evaluated. It was found that a subsurface lesion can develop only as the result of alternating periods of demineralisation (acid attack during sugar consumption) and remineralisation (resting period) in tooth enamel with uniform mineral composition. It was also shown that a minimum plaque thickness that can induce an enamel lesion exists. The subsurface lesion formation can also be explained by assuming the existence of a fluoride-containing layer at the tooth surface that decreases enamel solubility. A nearly constant thickness of the surface layer was obtained with both proposed mechanisms. Sensitivity analysis showed that surface layer formation is strongly dependent on the length of remineralisation and demineralisation cycles. The restoration period is very important and the numerical simulations support the observation that often consumption of sugars is a key factor in caries formation. The calculated profiles of mineral content in enamel are similar to those observed experimentally. Most probably, both studied mechanisms interact in vivo in the process of caries development, but the simplest explanation for subsurface lesion formation remains the alternation between demineralisation and remineralisation cycles without any pre-imposed gradients.

  7. Comparing Clinical Efficacy of Hyg and Ionic Toothbrushes in Removing Plaque from the Teeth

    Directory of Open Access Journals (Sweden)

    S Alaiee

    2013-08-01

    Full Text Available Introduction: Mechanical plaque control is the main way to prevent caries and periodontal diseases. Among the mechanical methods, daily use of toothbrush is considered as the best way to achieve oral health. Therefore, the purpose of this study was to evaluate clinical and microbiological efficacy of Hygenic toothbrushes in plaque removal. Methods: In this randomized clinical trial, 40 volunteers were selected. Patients were randomly divided into two groups, one group received toothbrushes with battery and the other group received toothbrushes without the battery. At the beginning of the study plaque score was measured and recorded. Patients brushed for a week and plaque was measured again. Then in both groups the first toothbrush was taken and the second brush was received by the volunteers in a cross over manner. In this regard, the mirobiological samples (colony forming units were determined before and after brushing. Data was analyzed by means of T- tests using the spss software. Results: The results showed that toothbrushes with and without battery reduced plaque score (respectively 98/22% and 26/19%. Colony forming units was reduced for both toothbrushes with battery (6/24% and without battery (9/5%. This indicates that toothbrushes with battery significantly reduced plaque compared to the ordinary toothbrushes. Conclusion: Hygenic toothbrushes reduce plaque score and microbial counts more effectively than ordinary toothbrushes.

  8. High wall shear stress and high-risk plaque: an emerging concept.

    Science.gov (United States)

    Eshtehardi, Parham; Brown, Adam J; Bhargava, Ankit; Costopoulos, Charis; Hung, Olivia Y; Corban, Michel T; Hosseini, Hossein; Gogas, Bill D; Giddens, Don P; Samady, Habib

    2017-01-10

    In recent years, there has been a significant effort to identify high-risk plaques in vivo prior to acute events. While number of imaging modalities have been developed to identify morphologic characteristics of high-risk plaques, prospective natural-history observational studies suggest that vulnerability is not solely dependent on plaque morphology and likely involves additional contributing mechanisms. High wall shear stress (WSS) has recently been proposed as one possible causative factor, promoting the development of high-risk plaques. High WSS has been shown to induce specific changes in endothelial cell behavior, exacerbating inflammation and stimulating progression of the atherosclerotic lipid core. In line with experimental and autopsy studies, several human studies have shown associations between high WSS and known morphological features of high-risk plaques. However, despite increasing evidence, there is still no longitudinal data linking high WSS to clinical events. As the interplay between atherosclerotic plaque, artery, and WSS is highly dynamic, large natural history studies of atherosclerosis that include WSS measurements are now warranted. This review will summarize the available clinical evidence on high WSS as a possible etiological mechanism underlying high-risk plaque development.

  9. The unstable plaque: a diagnostic challenge in cardiology; Diagnostische Herausforderung in der Kardiologie: Die instabile arteriosklerotische Plaque

    Energy Technology Data Exchange (ETDEWEB)

    Levkau, B. [Inst. fuer Pathophysiologie, Universitaetsklinikum Essen (Germany); Schaefers, M. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Muenster (Germany)

    2004-09-01

    Atherosclerotic plaque rupture still accounts for one third of all deaths worldwide and constitutes a major source of disability and health care costs. Dysregulation of MMPs in the atherosclerotic lesion may result in mechanical destabilization and rupture of the atherosclerotic plaque, potentially leading to thrombosis and vessel occlusion with life-threatening clinical complications. Therefore, identifying individual patients at high risk of plaque rupture is an important challenge in clinical medicine. We have used the broad-spectrum MMP inhibitor CGS 27023A to develop the radioligand [{sup 123}I]I-HO-CGS 27023A for in vivo imaging of MMP activity. Using this radioligand, we were able to specifically image MMP activity by scintigraphy in vivo in the MMP-rich vascular lesions that develop after carotid artery ligation and cholesterol-rich diet in apolipoprotein E-deficient mice. Thus, imaging of MMP activity in vivo is feasible using radiolabelled MMP inhibitors. In combination with the high-resolution morphological imaging techniques such as MRI and CT, the molecular imaging of individual disease parameters such as MMP activity in lesions of atherosclerosis may help design approaches for the prediction and prevention of coronary events due to plaque rupture of an individual lesion in an individual patient. (orig.)

  10. Relation between baseline plaque features and subsequent coronary artery remodeling determined by optical coherence tomography and intravascular ultrasound.

    Science.gov (United States)

    Xie, Zulong; Dong, Nana; Sun, Rong; Liu, Xinxin; Gu, Xia; Sun, Yong; Du, Hongwei; Dai, Jiannan; Liu, Youbin; Hou, Jingbo; Tian, Jinwei; Yu, Bo

    2017-01-17

    Atherosclerosis often leads to myocardial infarction and stroke. We examined the influence of baseline plaque characteristics on subsequent vascular remodeling in response to changes in plaque size. Using optical coherence tomography (OCT) and intravascular ultrasound (IVUS), we examined 213 plaques from 138 patients with acute coronary syndrome at baseline and repeated IVUS at the 12-month follow-up. The change in external elastic membrane (EEM) area for each 1 mm2 change in plaque area (i.e., the slope of the regression line) was calculated as a measure of vascular remodeling capacity. In plaques with static positive remodeling, the slope was smaller than in plaques without static positive remodeling. In addition, the slope of the regression line for lesions with a large plaque burden was much smaller than that for lesions with a small plaque burden. Multivariate linear regression analysis showed that diabetes, calcification and static positive remodeling were inversely and independently associated with the level of change in EEM area/change in plaque area. Lesions with a large plaque burden, calcifications or static positive remodeling had less remodeling capacity, and calcification and static positive remodeling were independent predictors of reduced subsequent remodeling. Therefore, calcifications and static positive remodeling could be used as morphological biomarkers to predict decreased subsequent arterial remodeling.

  11. Topical tazarotene vs. coal tar in stable plaque psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, U.; Kaur, I.; Dogra, S.; De, D.; Kumar, B. [Postgraduate Institute of Medical Education & Research, Chandigarh (India)

    2010-07-15

    The efficacy of topical tazarotene has not previously been compared with the conventional topical treatment of crude coal tar (CCT) in stable plaque psoriasis. In this nonblinded side-to-side comparison study, patients with chronic stable plaque psoriasis, who had bilaterally symmetrical plaques on the limbs, applied 0.1% tazarotene gel on the right side and 5% CCT ointment on the left side once daily for 12 weeks followed by an 8-week treatment-free follow up period. Severity of psoriatic lesions and response to treatment was evaluated by scoring erythema, scaling and induration (ESI). Of 30 patients recruited, 27 could be assessed. In the per-protocol analysis, the mean percentage reduction in ESI score at the end of the treatment period was 74.15% {+-} 9.43 and 77.37% {+-} 10.93 with tazarotene and CCT, respectively (P {gt} 0.05). A reduction in ESI score of {gt} 75% was seen in 11 (40.74%) and 16 (59.26%) patients with tazarotene and CCT, respectively, at the end of 12 weeks. Side-effects were seen in 48.14% of patients treated with tazarotene, but in no patient treated with CCT. Tazarotene 0.1% gel has comparable clinical efficacy to CCT 5% ointment. CCT ointment remains a cost-effective therapy for plaque psoriasis.

  12. Study on the Influence and Mechanism of Photodynamic Therapy on the Cariogenic Bacteria in Dental Plaque Biofilms%光动力疗法对牙菌斑生物膜内致龋菌的影响及作用机制的研究

    Institute of Scientific and Technical Information of China (English)

    常秀明; 邹朝晖; 阴慧娟

    2012-01-01

    Objective: To study the killing effects and mechanism of photodynamic therapy using hematoporphyrin monomethylether as photosensitizer on the cariogenic bacteria in dental plaque biofilms. Methods: S. mutans. S. sangius. L. acidophilus. A. viscosus had been chosen as the experimental bacteria to establish dental plaque biofilms model. Divide them into four groups; HMME-PDT group,HMME-PDT+ sodium azide group, cetylpyridinium chloride group, normal saline group. The influence of the cariogenic bacteria in plaque biofilms was observed according to plate counting of bacteria method. A pH reflect the acid production of cariogenic bacteria of the different treatments. Results: Compared to normal saline group, HMME-PDT and cetylpyridinium chloride made the number of cariogenic bacteria (CFU/mL) in plaque biofilms significantly reduced(Pplaque biofilms of HMME + sodium azide group was not significant different, with the bactericidal rate only 9. 47%.⊿ pH of the records showed that, HMME-PDT group could prevent the acid production of cariogenic bacteria in plaque biofilms in a certain time range (0-24h). Conclusion: PDT is an effective method in eliminating cariogenic bacteria of dental plaque biofilms and inhibiting the acid production,while singlet oxygen plays an important role in the sterile process of PDT.%目的:探讨以血卟啉单甲醚( hematoporphyrin monomethylether,HMME)为光敏剂的光动力疗法(photodynamic therapy,PDT)对牙菌斑生物膜内致龋菌的杀灭作用及机制.方法:以变形链球菌、血链球菌、嗜酸性乳杆菌和粘性放线菌为实验菌株,建立牙菌斑生物膜模型.实验分为4组:HMME- PDT组、HMME- PDT加叠氮钠组、西吡氯铵处理组、生理盐水处理组.平板菌落计数观察牙菌斑内致龋菌的活力,并测定不同处理前后pH的变化值(△pH)观察其对致龋菌产酸能力的影响.结

  13. PLAQUE ASSAY OF NEWCASTLE DISEASE VIRUS

    Directory of Open Access Journals (Sweden)

    B. Sardjono

    2012-09-01

    Full Text Available The Newcastle disease virus (NDV was isolated from a 3 months-old indigenous chicken (buras or kampung chicken which showed clinical signs of Newcastle disease (ND. For viral isolation a small part of the spleen and lung were inoculated into 10 days-old embryonated chicken eggs. The physical characteristics of the isolate (A/120 were studied. The hemagglutination of chicken red blood cell showed slow elution, thermostability of hemagglutinin at 56°C was 120 minutes. The vims was able to agglutinate horse erythrocytes but not those of sheep. The biological characteristics on mean death time (MDT of embryonated chicken egg and plaque morphology on chicken embryo fibroblast (CEF primary cell cultures were studied. The MDT was 56 hours, the isolate was velogenic NDV. There were three different plaque morphologies on CEF : 2 mm clear plaques, 1 mm clear plaques, and minute clear plaques which were visible only with microscopic examination.

  14. Modeling plaque fissuring and dissection during balloon angioplasty intervention.

    Science.gov (United States)

    Gasser, T Christian; Holzapfel, Gerhard A

    2007-05-01

    Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and/or dissection occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment site. We propose physical and finite element models, which are generally useable to trace fissuring and/or dissection in atherosclerotic plaques during balloon angioplasty interventions. The arterial wall is described as an anisotropic, heterogeneous, highly deformable, nearly incompressible body, whereas tissue failure is captured by a strong discontinuity kinematics and a novel cohesive zone model. The numerical implementation is based on the partition of unity finite element method and the interface element method. The later is used to link together meshes of the different tissue components. The balloon angioplasty-based failure mechanisms are numerically studied in 3D by means of an atherosclerotic-prone human external iliac artery, with a type V lesion. Image-based 3D geometry is generated and tissue-specific material properties are considered. Numerical results show that in a primary phase the plaque fissures at both shoulders of the fibrous cap and stops at the lamina elastica interna. In a secondary phase, local dissections between the intima and the media develop at the fibrous cap location with the smallest thickness. The predicted results indicate that plaque fissuring and dissection cause localized mechanical trauma, but prevent the main portion of the stenosis from high stress, and hence from continuous tissue damage.

  15. 青春期龈炎患者牙周可疑致病菌的检测%Bacteriological analysis of subgingival plaque in adolescents

    Institute of Scientific and Technical Information of China (English)

    吕绳漪; 时清; 杨圣辉

    2008-01-01

    目的 研究青春期龈炎患者龈下菌斑中牙周致病菌的变化特点及其与临床症状的相关性.方法 选择2006年6至10月于首都医科大学口腔医学院儿童口腔科及牙周科门诊就诊的11至17岁患者共54例.采集龈下菌斑样本108个,其中牙龈炎组(G组)30例(60个样本,牙龈轻度炎症20个样本,中度炎症19个样本,重度炎症21个样本),健康对照组(H组)15例(30个样本),慢性牙周炎对照组(P组)9例(18个样本),用细菌培养法检测产黑色素菌群、伴放线放线杆菌、放线菌、具核梭杆菌,同时记录取样牙牙周探诊深度(probing depth,PD)、牙龈指数(gingival index,GI)、出血指数(bleeding index,BI)、附着丧失(attachment loss,AL).结果 在H、G、P 3组中,产黑色素菌群的检出率分别为:3%、30%和100%;具核梭杆菌的检出率分别为:30%、68%和94%,3组相比差异有统计学意义(P<0.01).牙龈轻、中度炎症组具核梭杆菌和放线菌的菌落计数[分别为(3.8±0.7)和(5.3±0.9)]较H组[分别为(3.1±0.4)和(4.2±0.8)]明显增加(P<0.01);牙龈重度炎症组产黑色素菌群和具核梭杆菌菌落计数[分别为(4.7±1.2)和(4.4±0.8)]较轻度炎症组[分别为(3.1±0.5)和(3.8±0.7)]明显增加(P<0.01);而P组产黑色素菌群、具核梭杆菌、伴放线放线杆菌的菌落计数[分别为(6.6±1.0)、(5.5±1.0)和(4.2±1.7)]均比牙龈重度炎症组[分别为(4.7±1.2)、(4.4±0.8)和(2.6±0.9)]明显增加(P<0.01).产黑色素菌群、具核梭杆菌、伴放线放线杆菌的检出率和菌落计数均与BI、PD和AL呈正相关(P<0.01).结论 重度牙龈炎时,牙周致病菌已明显增加,提示牙周组织存在进一步破坏的危险,临床上应给予足够重视.%Objective To investigate the changes in characteristics of periodontal pathogens in subgingival plaque of patients with puberty gingivitis and its relevance with clinical symptoms.Methods A total of 108 subgingival plaque samples were collected

  16. Increased expression of fatty acid binding protein 4 and leptin in resident macrophages characterises atherosclerotic plaque rupture

    Science.gov (United States)

    Lee, K.; Santibanez-Koref, M.; Polvikoski, T.; Birchall, D.; Mendelow, A.D.; Keavney, B.

    2013-01-01

    Objective Resident macrophages play an important role in atheromatous plaque rupture. The macrophage gene expression signature associated with plaque rupture is incompletely defined due to the complex cellular heterogeneity in the plaque. We aimed to characterise differential gene expression in resident plaque macrophages from ruptured and stable human atheromatous lesions. Methods and results We performed genome-wide expression analyses of isolated macrophage-rich regions of stable and ruptured human atherosclerotic plaques. Plaques present in carotid endarterectomy specimens were designated as stable or ruptured using clinical, radiological and histopathological criteria. Macrophage-rich regions were excised from 5 ruptured and 6 stable plaques by laser micro-dissection. Transcriptional profiling was performed using Affymetrix microarrays. The profiles were characteristic of activated macrophages. At a false discovery rate of 10%, 914 genes were differentially expressed between stable and ruptured plaques. The findings were confirmed in fourteen further stable and ruptured samples for a subset of eleven genes with the highest expression differences (p < 0.05). Pathway analysis revealed that components of the PPAR/Adipocytokine signaling pathway were the most significantly upregulated in ruptured compared to stable plaques (p = 5.4 × 10−7). Two key components of the pathway, fatty-acid binding-protein 4 (FABP4) and leptin, showed nine-fold (p = 0.0086) and five-fold (p = 0.0012) greater expression respectively in macrophages from ruptured plaques. Conclusions We found differences in gene expression signatures between macrophages isolated from stable and ruptured human atheromatous plaques. Our findings indicate the involvement of FABP4 and leptin in the progression of atherosclerosis and plaque rupture, and suggest that down-regulation of PPAR/adipocytokine signaling within plaques may have therapeutic potential. PMID:23122912

  17. Molecular mechanics conformational analysis of tylosin

    Science.gov (United States)

    Ivanov, Petko M.

    1998-01-01

    The conformations of the 16-membered macrolide antibiotic tylosin were studied with molecular mechanics (AMBER∗ force field) including modelling of the effect of the solvent on the conformational preferences (GB/SA). A Monte Carlo conformational search procedure was used for finding the most probable low-energy conformations. The present study provides complementary data to recently reported analysis of the conformations of tylosin based on NMR techniques. A search for the low-energy conformations of protynolide, a 16-membered lactone containing the same aglycone as tylosin, was also carried out, and the results were compared with the observed conformation in the crystal as well as with the most probable conformations of the macrocyclic ring of tylosin. The dependence of the results on force field was also studied by utilizing the MM3 force field. Some particular conformations were computed with the semiempirical molecular orbital methods AM1 and PM3.

  18. Pharmaceutical applications of dynamic mechanical thermal analysis.

    Science.gov (United States)

    Jones, David S; Tian, Yiwei; Abu-Diak, Osama; Andrews, Gavin P

    2012-04-01

    The successful development of polymeric drug delivery and biomedical devices requires a comprehensive understanding of the viscoleastic properties of polymers as these have been shown to directly affect clinical efficacy. Dynamic mechanical thermal analysis (DMTA) is an accessible and versatile analytical technique in which an oscillating stress or strain is applied to a sample as a function of oscillatory frequency and temperature. Through cyclic application of a non-destructive stress or strain, a comprehensive understanding of the viscoelastic properties of polymers may be obtained. In this review, we provide a concise overview of the theory of DMTA and the basic instrumental/operating principles. Moreover, the application of DMTA for the characterization of solid pharmaceutical and biomedical systems has been discussed in detail. In particular we have described the potential of DMTA to measure and understand relaxation transitions and miscibility in binary and higher-order systems and describe the more recent applications of the technique for this purpose.

  19. Recognition and Analysis of Corrosion Failure Mechanisms

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    Steven Suess

    2006-02-01

    Full Text Available Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, material evaluation, data review and conclusion procurement. In analyzing corrosion failures, one must recognize the wide range of common corrosion mechanisms. The features of any corrosion failure give strong clues as to the most likely cause of the corrosion. This article details a proven approach to properly determining the root cause of a failure, and includes pictographic illustrations of the most common corrosion mechanisms, including general corrosion, pitting, galvanic corrosion, dealloying, crevice corrosion, microbiologically-influenced corrosion (MIC, corrosion fatigue, stress corrosion cracking (SCC, intergranular corrosion, fretting, erosion corrosion and hydrogen damage.

  20. Thermal mechanical analysis of sprag clutches

    Science.gov (United States)

    Mullen, Robert L.; Zab, Ronald Joseph; Kurniawan, Antonius S.

    1992-01-01

    Work done at Case Western Reserve University on the Thermal Mechanical analysis of sprag helicopter clutches is reported. The report is presented in two parts. The first part is a description of a test rig for the measurement of the heat generated by high speed sprag clutch assemblies during cyclic torsional loading. The second part describes a finite element modeling procedure for sliding contact. The test rig provides a cyclic torsional load of 756 inch-pounds at 5000 rpm using a four-square arrangement. The sprag clutch test unit was placed between the high speed pinions of the circulating power loop. The test unit was designed to have replaceable inner ad outer races, which contain the instrumentation to monitor the sprag clutch. The torque loading device was chosen to be a water cooled magnetic clutch, which is controlled either manually or through a computer. In the second part, a Generalized Eulerian-Lagrangian formulation for non-linear dynamic problems is developed for solid materials. This formulation is derived from the basic laws and axioms of continuum mechanics. The novel aspect of this method is that we are able to investigate the physics in the spatial region of interest as material flows through it without having to follow material points. A finite element approximation to the governing equations is developed. Iterative Methods for the solution of the discrete finite element equations are explored. A FORTRAN program to implement this formulation is developed and a number of solutions to problems of sliding contact are presented.

  1. Haemodynamical stress in mouse aortic arch with atherosclerotic plaques: Preliminary study of plaque progression

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    P. Assemat

    2014-07-01

    Full Text Available Atherosclerotic plaques develop at particular sites in the arterial tree, and this regional localisation depends largely on haemodynamic parameters (such as wall shear stress; WSS as described in the literature. Plaque rupture can result in heart attack or stroke and hence understanding the development and vulnerability of atherosclerotic plaques is critically important. The purpose of this study is to characterise the haemodynamics of blood flow in the mouse aortic arch using numerical modelling. The geometries are digitalised from synchrotron imaging and realistic pulsatile blood flow is considered under rigid wall assumptions. Two cases are considered; arteries with and without plaque. Mice that are fed under fat diet present plaques in the aortic arch whose size is dependent on the number of weeks under the diet. The plaque distribution in the region is however relatively constant through the different samples. This result underlines the influence of the geometry and consequently of the wall shear stresses for plaque formation with plaques growing in region of relative low shear stresses. A discussion of the flow field in real geometry in the presence and absence of plaques is conducted. The presence of plaques was shown to alter the blood flow and hence WSS distribution, with regions of localised high WSS, mainly on the wall of the brachiocephalic artery where luminal narrowing is most pronounced. In addition, arch plaques are shown to induce recirculation in the blood flow, a phenomenon with potential influence on the progression of the plaques. The oscillatory shear index and the relative residence time have been calculated on the geometry with plaques to show the presence of this recirculation in the arch, an approach that may be useful for future studies on plaque progression.

  2. Statistical mechanics analysis of sparse data.

    Science.gov (United States)

    Habeck, Michael

    2011-03-01

    Inferential structure determination uses Bayesian theory to combine experimental data with prior structural knowledge into a posterior probability distribution over protein conformational space. The posterior distribution encodes everything one can say objectively about the native structure in the light of the available data and additional prior assumptions and can be searched for structural representatives. Here an analogy is drawn between the posterior distribution and the canonical ensemble of statistical physics. A statistical mechanics analysis assesses the complexity of a structure calculation globally in terms of ensemble properties. Analogs of the free energy and density of states are introduced; partition functions evaluate the consistency of prior assumptions with data. Critical behavior is observed with dwindling restraint density, which impairs structure determination with too sparse data. However, prior distributions with improved realism ameliorate the situation by lowering the critical number of observations. An in-depth analysis of various experimentally accessible structural parameters and force field terms will facilitate a statistical approach to protein structure determination with sparse data that avoids bias as much as possible.

  3. MECHANISM ANALYSIS AND MATHEMATICAL DESCRIPTION OF MECHANICAL ABRUP TFAULTS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Gradual faults and abrupt faults of mechanical systems are differentiated by variation patterns of state var ibles.After the reasons of abrupt faults are analyzed by nonlinear dynamics,two methods establishing the mathematical models for abrupt faults are presented.As an example,a cusp catastrophe model of the vibration amplitudes of a Jeffcott rotor with nonlinear stiffness and its parameter condition of the vibration state catastrophe are obtained.

  4. A negative correlation between human carotid atherosclerotic plaque progression and plaque wall stress: in vivo MRI-based 2D/3D FSI models.

    Science.gov (United States)

    Tang, Dalin; Yang, Chun; Mondal, Sayan; Liu, Fei; Canton, Gador; Hatsukami, Thomas S; Yuan, Chun

    2008-01-01

    It is well accepted that atherosclerosis initiation and progression correlate positively with low and oscillating flow wall shear stresses (FSS). However, this mechanism cannot explain why advanced plaques continue to grow under elevated FSS conditions. In vivo magnetic resonance imaging (MRI)-based 2D/3D multi-component models with fluid-structure interactions (FSI, 3D only) for human carotid atherosclerotic plaques were introduced to quantify correlations between plaque progression measured by wall thickness increase (WTI) and plaque wall (structure) stress (PWS) conditions. A histologically validated multi-contrast MRI protocol was used to acquire multi-year in vivo MRI images. Our results using 2D models (200-700 data points/patient) indicated that 18 out of 21 patients studied showed significant negative correlation between WTI and PWS at time 2 (T2). The 95% confidence interval for the Pearson correlation coefficient is (-0.443,-0.246), p<0.0001. Our 3D FSI model supported the 2D correlation results and further indicated that combining both plaque structure stress and flow shear stress gave better approximation results (PWS, T2: R(2)=0.279; FSS, T1: R(2)=0.276; combining both: R(2)=0.637). These pilot studies suggest that both lower PWS and lower FSS may contribute to continued plaque progression and should be taken into consideration in future investigations of diseases related to atherosclerosis.

  5. Fibrillar amyloid plaque formation precedes microglial activation.

    Directory of Open Access Journals (Sweden)

    Christian K E Jung

    Full Text Available In Alzheimer's disease (AD, hallmark β-amyloid deposits are characterized by the presence of activated microglia around them. Despite an extensive characterization of the relation of amyloid plaques with microglia, little is known about the initiation of this interaction. In this study, the detailed investigation of very small plaques in brain slices in AD transgenic mice of the line APP-PS1(dE9 revealed different levels of microglia recruitment. Analysing plaques with a diameter of up to 10 μm we find that only the half are associated with clear morphologically activated microglia. Utilizing in vivo imaging of new appearing amyloid plaques in double-transgenic APP-PS1(dE9xCX3CR1+/- mice further characterized the dynamic of morphological microglia activation. We observed no correlation of morphological microglia activation and plaque volume or plaque lifetime. Taken together, our results demonstrate a very prominent variation in size as well as in lifetime of new plaques relative to the state of microglia reaction. These observations might question the existing view that amyloid deposits by themselves are sufficient to attract and activate microglia in vivo.

  6. Association of carotid plaque Lp-PLA(2 with macrophages and Chlamydia pneumoniae infection among patients at risk for stroke.

    Directory of Open Access Journals (Sweden)

    Berna Atik

    Full Text Available BACKGROUND: We previously showed that the burden of Chlamydia pneumoniae in carotid plaques was significantly associated with plaque interleukin (IL-6, and serum IL-6 and C-reactive protein (CRP, suggesting that infected plaques contribute to systemic inflammatory markers in patients with stroke risk. Since lipoprotein-associated phospholipase A2 (Lp-PLA(2 mediates inflammation in atherosclerosis, we hypothesized that serum Lp-PLA(2 mass and activity levels and plaque Lp-PLA(2 may be influenced by plaque C. pneumoniae infection. METHODOLOGY/PRINCIPAL FINDINGS: Forty-two patients underwent elective carotid endarterectomy. Tissue obtained at surgery was stained by immunohistochemistry for Lp-PLA(2 grade, macrophages, IL-6, C. pneumoniae and CD4+ and CD8+ cells. Serum Lp-PLA(2 activity and mass were measured using the colorimetric activity method (CAM and ELISA, respectively. Serum homocysteine levels were measured by HPLC. Eleven (26.2% patients were symptomatic with transient ischemic attacks. There was no correlation between patient risk factors (smoking, coronary artery disease, elevated cholesterol, diabetes, obesity, hypertension and family history of genetic disorders for atherosclerosis and serum levels or plaque grade for Lp-PLA(2. Plaque Lp-PLA(2 correlated with serum homocysteine levels (p = 0.013, plaque macrophages (p<0.01, and plaque C. pneumoniae (p<0.001, which predominantly infected macrophages, co-localizing with Lp-PLA(2. CONCLUSIONS: The significant association of plaque Lp-PLA(2 with plaque macrophages and C. pneumoniae suggests an interactive role in accelerating inflammation in atherosclerosis. A possible mechanism for C. pneumoniae in the atherogenic process may involve infection of macrophages that induce Lp-PLA(2 production leading to upregulation of inflammatory mediators in plaque tissue. Additional in vitro and in vivo research will be needed to advance our understanding of specific C. pneumoniae and Lp-PLA(2

  7. Angiogenesis in atherosclerotic plaque obtained from carotid endarterectomy: association between symptomatology and plaque morphology.

    Science.gov (United States)

    Hiyama, Takami; Tanaka, Toshihide; Endo, Shinichi; Komine, Kazumasa; Kudo, Tadashi; Kobayashi, Hiroo; Shiokawa, Yoshiaki

    2010-01-01

    Carotid plaque with hemorrhage leads to cerebral embolism and ischemic stroke. Plaque angiogenesis and angiogenetic factors such as vascular endothelial growth factor (VEGF) are critical in the progression of atherosclerotic carotid plaque and intraplaque hemorrhage. The correlation between plaque angiogenesis and presence of clinical symptoms was studied in 41 specimens obtained during carotid endarterectomy from 20 symptomatic and 21 asymptomatic patients treated for carotid artery stenosis. Histological findings using hematoxylin-eosin and immunohistochemical staining against von Willebrand factor and VEGF were examined. Intraplaque hemorrhage, calcification, necrosis, and invasion of foam cells were frequently observed in the carotid plaques from symptomatic patients compared with asymptomatic patients. Higher microvessel density was found in the carotid plaques with necrosis and invasion of foam cells compared with plaques without necrosis and/or foam cell invasion, and higher expression of VEGF was found from symptomatic patients compared with asymptomatic patents. These results suggest that plaque angiogenesis and higher level of VEGF expression may enhance the progression of ischemic symptoms in patients with carotid artery stenosis. Invasive macrophages in the plaque of symptomatic patients increase levels of VEGF and might enhance plaque angiogenesis and atherosclerosis progression.

  8. Color doppler ultrasonography and multislice computer tomography angiography in carotid plaque detection and characterization

    Directory of Open Access Journals (Sweden)

    Vučaj-Ćirilović Viktorija

    2011-01-01

    Full Text Available Beckground/Aim. Cerebrovascular diseases are the third leading cause of mortality in the world, following malignant and cardiovascular diseases. Therefore, their timely and precise diagnostics is of great importance. The aim of this study was to compare duplex scan Color Doppler ultrasonography (CDU with multislice computed tomography angiography (MSCTA in detection of morphological and functional disorders at extracranial level of carotid arteries. Methods. The study included 75 patients with 150 carotid arteries examined in the period from January 2008 to April 2009. The patients were firstly examined by CDU, then MSCTA, followed by the surgery of extracranial segment of carotid arteries. In 10 patients, the obtained material was referred for histopathological (HP examination. We used both CDU and MSCT in the analysis of: plaque surface, plaque structure, degree of stenosis, and the presence of intraplaque hemorrhage. Results. The results obtained by CDU and MSCTA were first compared between themselves, and then to intraoperative findings. Retrospective analysis showed that MSCTA is more sensitive than CDU in assessment of plaque surface (for smooth plaques CDU 89% : MSCTA 97%; for plaques with irregular surface CDU 75% : MSCTA 87%; for ulcerations CDU 54% : MSCTA 87%. Regarding determination of plaque structure (mixed plaque CDU 66% : MSCTA 70%; correlation with HP findings CDU 94% : MSCTA 96% and localization (CDU 63% : MSCTA 65%, and in terms of sensitivity and specificity, both methods showed almost the same results. Also, there is no statistical difference between these two methods for the degree of stenosis (CDU 96% : MSCTA 98%. Conclusion. Atherosclerotic disease of extracranial part of carotid arteries primarily affects population of middle-aged and elderly, showing more associated risk factors. Sensitivity and specificity of CDU and MSCTA regarding plaque composition, the degree of stenosis and plaque localization are almost the same

  9. Magnetic force microscopy of atherosclerotic plaque

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    Alexeeva T.A.

    2014-03-01

    Full Text Available In this work by methods of scanning probe microscopy, namely by atomic force microscopy and magnetic force microscopy the fragments of atherosclerotic plaque section of different nature were investigated. The fragments of atherosclerotic vessels with elements of immature plaque were taken during the coiled artery bypass surgery by alloprosthesis. As the result of investigation we found magnetically ordered phase of endogenous origin in the fragment of solid plaque of mixed structure. This phase is presents biogenic magnetic nanoparticles and their clusters with average size characteristic of 200-400 nm.

  10. The prevention and regression of atherosclerotic plaques: emerging treatments

    Directory of Open Access Journals (Sweden)

    Kalanuria AA

    2012-09-01

    Full Text Available Atul Ashok Kalanuria,1 Paul Nyquist,1 Geoffrey Ling1,21Division of Neuro Critical Care, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, 2Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, MD, USAAbstract: Occlusive vascular diseases, such as sudden coronary syndromes, stroke, and peripheral arterial disease, are a huge burden on the health care systems of developed and developing countries. Tremendous advances have been made over the last few decades in the diagnosis and treatment of atherosclerotic diseases. Intravascular ultrasound has been able to provide detailed information of plaque anatomy and has been used in several studies to assess outcomes. The presence of atherosclerosis disrupts the normal protective mechanism provided by the endothelium and this mechanism has been implicated in the pathophysiology of coronary artery disease and stroke. Efforts are being put into the prevention of atherosclerosis, which has been shown to begin in childhood. This paper reviews the pathophysiology of atherosclerosis and discusses the current options available for the prevention and reversal of plaque formation.Keywords: cardiovascular, atherosclerotic disease, endothelium, plaque, reversal, coronary artery disease, stroke

  11. PERFORMANCE ANALYSIS OF MECHANICAL DRAFT COOLING TOWER

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

    2009-02-10

    Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has cross-flow and counter-current MDCT's consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to simulate the cooling tower performance for the counter-current cooling tower and to conduct a parametric study under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model and performed the benchmarking analysis against the integral measurement results to accomplish the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of parametric calculations was performed to investigate the impact of wind speeds and ambient conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was also benchmarked against the literature data and the SRS integral test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be published here.

  12. Arterial luminal curvature and fibrous-cap thickness affect critical stress conditions within atherosclerotic plaque: an in vivo MRI-based 2D finite-element study.

    Science.gov (United States)

    Teng, Zhongzhao; Sadat, Umar; Li, Zhiyong; Huang, Xueying; Zhu, Chengcheng; Young, Victoria E; Graves, Martin J; Gillard, Jonathan H

    2010-10-01

    High mechanical stress in atherosclerotic plaques at vulnerable sites, called critical stress, contributes to plaque rupture. The site of minimum fibrous cap (FC) thickness (FC(MIN)) and plaque shoulder are well-documented vulnerable sites. The inherent weakness of the FC material at the thinnest point increases the stress, making it vulnerable, and it is the big curvature of the lumen contour over FC which may result in increased plaque stress. We aimed to assess critical stresses at FC(MIN) and the maximum lumen curvature over FC (LC(MAX)) and quantify the difference to see which vulnerable site had the highest critical stress and was, therefore, at highest risk of rupture. One hundred patients underwent high resolution carotid magnetic resonance (MR) imaging. We used 352 MR slices with delineated atherosclerotic components for the simulation study. Stresses at all the integral nodes along the lumen surface were calculated using the finite-element method. FC(MIN) and LC(MAX) were identified, and critical stresses at these sites were assessed and compared. Critical stress at FC(MIN) was significantly lower than that at LC(MAX) (median: 121.55 kPa; inter quartile range (IQR) = [60.70-180.32] kPa vs. 150.80 kPa; IQR = [91.39-235.75] kPa, p LC(MAX) only was used, then 112 out of 352 would be underestimated. Stress analysis at FC(MIN) and LC(MAX) should be used for a refined mechanical risk assessment of atherosclerotic plaques, since material failure at either site may result in rupture.

  13. 磁共振成像用于区分冠状动脉斑块成分的Meta分析%Distinction of coronary atherosclerotic plaques with magnetic resonance imaging: a Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    王永智; 李云娟; 浦奎; 郭峰; 张会; 秘春敬

    2016-01-01

    Objective To review the feasibility and veracity of magnetic resonance imaging (MRI) in distinction of coronary atherosclerotic plaques by using Meta-analysis method.Methods The databases of Cochrane Library, PubMed, OVID, EBSCO, CNKI, CBM and WanFang Database were retrieved with computer until to Dec. 31, 2014 for collecting studies on distinction of coronary atherosclerotic plaques with MRI, and screening the documents according to the recommendation by Cochrane Collaboration. The documents were analyzed by using STATA 12.0 software and Meta-disc 1.4 software, including heterogeneity test, public bias test, Meta-regression, clinical pragmatic investigation, pooled sensitivity (SEN), specificity (SPE), diagnostic odds ratio (DOR) and 95% confidence interval (95%CI). The summary receiver operating characteristic curve (SROC) and area under curve (AUC) were drawn and calculated. Results There were totally 6 documents included. SEN was [0.92 (95%CI: 0.86~0.9), SPE was [0.89 (95%CI:0.82~0.94)], DOR was [56.09 (95%CI: 18.41~212.49)], and AUC was 0.9451 in summarized identification of lipid-rich composition. SEN was [0.88 (0.79~0.94)], SPE was [0.96 (0.91~0.98)], DOR was [78.95 (22.01~283.28)], and AUC was 0.9291 in identification of calcification composition.Conclusion MRI is highly accurate in distinction of lipid-rich composition and calcification composition in coronary atherosclerotic plaques.%目的 用Meta分析的方法评价磁共振成像区分冠状动脉粥样斑块组成成分的可行性及准确性.方法 计算机检索Cochrane Library、PubMed、OVID、EBSCO、中国期刊全文数据库、中国生物医学文献数据库和万方数据库,时间截止至2014年12月31日.纳入关于磁共振成像识别区分冠状动脉粥样硬化斑块成分的研究文献,结合Cochrane协作网推荐内容制定纳入标准筛选文献,然后采用STATA 12.0和Meta-disc 1.4软件对资料进行统计分析,包括异质性检验、发表偏倚检测、Meta回归

  14. A retrospective study of the probability of the evolution of parapsoriasis en plaques into mycosis fungoides.

    Science.gov (United States)

    Väkevä, Liisa; Sarna, Seppo; Vaalasti, Annikki; Pukkala, Eero; Kariniemi, Arja-Leena; Ranki, Annamari

    2005-01-01

    Parapsoriasis en plaque has been suggested to be an early manifestation of mycosis fungoides (cutaneous T-cell lymphoma). We explored the disease course of patients with small plaque or large plaque parapsoriasis in a 26-year retrospective cohort analysis of 105 parapsoriasis patients, who were clinically and histopathologically followed up in Helsinki and Tampere University Hospitals. Eventual later cancers of these patients were verified from the Finnish Cancer Registry. In the small plaque parapsoriasis group, 7 patients (10%) and in the large plaque parapsoriasis group 12 patients (35%), developed histologically confirmed mycosis fungoides during a median of 10 and 6 years, respectively. No significant differences were found regarding the risk of developing mycosis fungoides or the tendency to remission in patients treated with or without phototherapy. Our results show that not only large plaque parapsoriasis, but also small plaque parapsoriasis, as currently defined in textbooks, can progress to mycosis fungoides. The benefits of phototherapy are equivocal in parapsoriasis treatment as far as progression to cancer is concerned.

  15. Identification of High-Risk Plaques by MRI and Fluorescence Imaging in a Rabbit Model of Atherothrombosis.

    Directory of Open Access Journals (Sweden)

    Ning Hua

    Full Text Available The detection of atherosclerotic plaques at risk for disruption will be greatly enhanced by molecular probes that target vessel wall biomarkers. Here, we test if fluorescently-labeled Activatable Cell Penetrating Peptides (ACPPs could differentiate stable plaques from vulnerable plaques that disrupt, forming a luminal thrombus. Additionally, we test the efficacy of a combined ACPP and MRI technique for identifying plaques at high risk of rupture.In an atherothrombotic rabbit model, disrupted plaques were identified with in vivo MRI and co-registered in the same rabbit aorta with the in vivo uptake of ACPPs, cleaved by matrix metalloproteinases (MMPs or thrombin. ACPP uptake, mapped ex vivo in whole aortas, was higher in disrupted compared to non-disrupted plaques. Specifically, disrupted plaques demonstrated a 4.5~5.0 fold increase in fluorescence enhancement, while non-disrupted plaques showed only a 2.2~2.5 fold signal increase. Receiver operating characteristic (ROC analysis indicates that both ACPPs (MMP and thrombin show high specificity (84.2% and 83.2% and sensitivity (80.0% and 85.7% in detecting disrupted plaques. The detection power of ACPPs was improved when combined with the MRI derived measure, outward remodeling ratio.Our targeted fluorescence ACPP probes distinguished disrupted plaques from stable plaques with high sensitivity and specificity. The combination of anatomic, MRI-derived predictors for disruption and ACPP uptake can further improve the power for identification of high-risk plaques and suggests future development of ACPPs with molecular MRI as a readout.

  16. Genesis and growth of extracellular-vesicle-derived microcalcification in atherosclerotic plaques

    Science.gov (United States)

    Hutcheson, Joshua D.; Goettsch, Claudia; Bertazzo, Sergio; Maldonado, Natalia; Ruiz, Jessica L.; Goh, Wilson; Yabusaki, Katsumi; Faits, Tyler; Bouten, Carlijn; Franck, Gregory; Quillard, Thibaut; Libby, Peter; Aikawa, Masanori; Weinbaum, Sheldon; Aikawa, Elena

    2016-03-01

    Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification areas. We also show that calcification morphology and the plaque’s collagen content--two determinants of atherosclerotic plaque stability--are interlinked.

  17. Genesis and growth of extracellular vesicle-derived microcalcification in atherosclerotic plaques

    Science.gov (United States)

    Hutcheson, Joshua D.; Goettsch, Claudia; Bertazzo, Sergio; Maldonado, Natalia; Ruiz, Jessica L.; Goh, Wilson; Yabusaki, Katsumi; Faits, Tyler; Bouten, Carlijn; Franck, Gregory; Quillard, Thibaut; Libby, Peter; Aikawa, Masanori; Weinbaum, Sheldon; Aikawa, Elena

    2015-01-01

    Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification zones. We also show that calcification morphology and the plaque’s collagen content – two determinants of atherosclerotic plaque stability - are interlinked. PMID:26752654

  18. Large plaque parapsoriasis in a child

    OpenAIRE

    Das Jayanta; Gangopadhyay Asok

    2005-01-01

    A case of large plaque parapsoriasis with extensive skin lesions is presented for its unusual clinical features. The controversial issue of its nosological position is discussed as it has a considerable impact on the management of such cases.

  19. Sticky Brain 'Plaques' Implicated in Alzheimer's Again

    Science.gov (United States)

    ... fullstory_166550.html Sticky Brain 'Plaques' Implicated in Alzheimer's Again Researchers believe these substances form in early ... in the brain signals an early stage of Alzheimer's disease. It's been known for years that in ...

  20. Compositional volumetry of non-calcified coronary plaques by multislice computed tomography: An ex vivo feasibility study

    NARCIS (Netherlands)

    N. Bruining (Nico); J.R.T.C. Roelandt (Jos); S. Verheye (Stefan); M.W. Knaapen (Michiel); Y. Onuma (Yoshinobu); E.S. Regar (Eveline); F. Cademartiri (Filippo); S. de Winter (Sebastiaan); G.J.J. van Langenhove (Glenn); P.W.J.C. Serruys (Patrick); R. Hamers (Ronald); P.J. de Feyter (Pim)

    2009-01-01

    textabstractAims: Non-invasive quantitative compositional analysis of coronary plaque would be a major advantage to study coronary artery disease. This study explores the application to use the Hounsfield units (HU) distribution of coronary plaques imaged by multislice computed tomography-coronary

  1. 口腔牙菌斑与呼吸机相关性肺炎的关系%Relationship of dental plaque and ventilator associated pneumonia

    Institute of Scientific and Technical Information of China (English)

    高伟良; 王凌伟; 吴伟元; 陶维华

    2015-01-01

    Objective To investigate the relationship of dental plaque and ventilator associated pneumonia (VAP)in patients undergoing mechanical ventilation.Methods A total of 30 patients with VAP who were admitted into the intensive care unit of hospital were selected.Dental plaques and bronchoalveolar lavage fluids (BALF)samples from patients were cultured,the bacteria from the BALF and dental plaques were identified and homology analysis was determined by pulsed-field gel electrophoresis.Results Aerobic bacteria were cultured from 22 dental plaques of 30 patients,including 1 5 patients with equal to or greater than 2 kinds of bacteria;aerobic bacteria were cultured from 1 7 BALF samples.The proportion of gram-negative bacteria was higher than that of gram-positive bacteria isolating from both the dental plaques and BALF samples.Bacteria from 10 BALF samples showed highly homologous with those of dental plaques samples.Conclusion Dental plaques are closely related to VAP and may serve as important reservoir for respiratory pathogens in patients undergoing mechanical ventilation.%目的:探讨机械通气患者口腔牙菌斑与呼吸机相关性肺炎(VAP)的关系。方法选择我院重症监护病房行机械通气后并发 VAP 的30例患者,同时取其口腔牙菌斑和肺泡灌洗液进行培养,并进行细菌鉴定和同源性分析。结果30例患者中有22例的牙菌斑能培养出需氧细菌,其中15例的牙菌斑培养出的需氧菌≥2种;17例患者的肺泡灌洗液能培养出需氧细菌。牙菌斑和肺泡灌洗液培养出的革兰阴性菌的比例均高于革兰阳性菌。17个肺泡灌洗液样本中有10个和自身牙菌斑所培养出来的细菌具有高度同源性。结论口腔牙菌斑与 VAP 的发生密切相关,可能是机械通气患者呼吸道病原体的一个重要来源。

  2. Early canine plaque biofilms: characterization of key bacterial interactions involved in initial colonization of enamel.

    Directory of Open Access Journals (Sweden)

    Lucy J Holcombe

    Full Text Available Periodontal disease (PD is a significant problem in dogs affecting between 44% and 63.6% of the population. The main etiological agent for PD is plaque, a microbial biofilm that colonizes teeth and causes inflammation of the gingiva. Understanding how this biofilm initiates on the tooth surface is of central importance in developing interventions against PD. Although the stages of plaque development on human teeth have been well characterized little is known about how canine plaque develops. Recent studies of the canine oral microbiome have revealed distinct differences between the canine and human oral environments and the bacterial communities they support, particularly with respect to healthy plaque. These differences mean knowledge about the nature of plaque formation in humans may not be directly translatable to dogs. The aim of this study was to identify the bacterial species important in the early stages of canine plaque formation in vivo and then use isolates of these species in a laboratory biofilm model to develop an understanding of the sequential processes which take place during the initial colonization of enamel. Supra-gingival plaque samples were collected from 12 dogs at 24 and 48 hour time points following a full mouth descale and polish. Pyrosequencing of the 16S rDNA identified 134 operational taxonomic units after statistical analysis. The species with the highest relative abundance were Bergeyella zoohelcum, Neisseria shayeganii and a Moraxella species. Streptococcal species, which tend to dominate early human plaque biofilms, had very low relative abundance. In vitro testing of biofilm formation identified five primary colonizer species, three of which belonged to the genus Neisseria. Using these pioneer bacteria as a starting point, viable two and three species communities were developed. Combining in vivo and in vitro data has led us to construct novel models of how the early canine plaque biofilm develops.

  3. Uptake of inflammatory cell marker [{sup 11}C]PK11195 into mouse atherosclerotic plaques

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, Iina; Marjamaeki, Paeivi; Naagren, Kjell; Roivainen, Anne; Knuuti, Juhani [University of Turku, Turku PET Centre, Turku (Finland); Laine, V.J.O. [Turku University Hospital, Department of Pathology, Turku (Finland); Wilson, Ian [GE Healthcare Biosciences, Medical Diagnostics, London (United Kingdom); Leppaenen, Pia; Ylae-Herttuala, Seppo [University of Kuopio, A.I. Virtanen Institute, Kuopio (Finland)

    2009-01-15

    The ligand [{sup 11}C]PK11195 binds with high affinity and selectivity to peripheral benzodiazepine receptor, expressed in high amounts in macrophages. In humans, [{sup 11}C]PK11195 has been used successfully for the in vivo imaging of inflammatory processes of brain tissue. The purpose of this study was to explore the feasibility of [{sup 11}C]PK11195 in imaging inflammation in the atherosclerotic plaques. The presence of PK11195 binding sites in the atherosclerotic plaques was verified by examining the in vitro binding of [{sup 3}H]PK11195 onto mouse aortic sections. Uptake of intravenously administered [{sup 11}C]PK11195 was studied ex vivo in excised tissue samples and aortic sections of a LDLR/ApoB48 atherosclerotic mice. Accumulation of the tracer was compared between the atherosclerotic plaques and non-atherosclerotic arterial sites by autoradiography and histological analyses. The [{sup 3}H]PK11195 was found to bind to both the atherosclerotic plaques and the healthy wall. The autoradiography analysis revealed that the uptake of [{sup 11}C]PK11195 to inflamed regions in plaques was more prominent (p = 0.011) than to non-inflamed plaque regions, but overall it was not higher than the uptake to the healthy vessel wall. Also, the accumulation of {sup 11}C radioactivity into the aorta of the atherosclerotic mice was not increased compared to the healthy control mice. Our results indicate that the uptake of [{sup 11}C]PK11195 is higher in inflamed atherosclerotic plaques containing a large number of inflammatory cells than in the non-inflamed plaques. However, the tracer uptake to other structures of the artery wall was also prominent and may limit the use of [{sup 11}C]PK11195 in clinical imaging of atherosclerotic plaques. (orig.)

  4. The use of Speckle Reduction Imaging (SRI) Ultrasound in the characterization of carotid artery plaques

    Energy Technology Data Exchange (ETDEWEB)

    Liasis, Nikolaos [1st Department of Surgery, Vascular Division, ' LAIKON' Hospital, Athens University Medical School (Greece)], E-mail: nliasis@forthnet.gr; Klonaris, Chris [1st Department of Surgery, Vascular Division, ' LAIKON' Hospital, Athens University Medical School (Greece)], E-mail: chris_klonaris@yahoo.com; Katsargyris, Athanasios [1st Department of Surgery, Vascular Division, ' LAIKON' Hospital, Athens University Medical School (Greece)], E-mail: kthanassos@yahoo.com; Georgopoulos, Sotirios [1st Department of Surgery, Vascular Division, ' LAIKON' Hospital, Athens University Medical School (Greece)], E-mail: sgeorg@med.uoa.gr; Labropoulos, Nicos [Division of Vascular Surgery, University of Medicine and Dentistry of New Jersey, Newark (United States)], E-mail: nlabrop@yahoo.com; Tsigris, Chris [1st Department of Surgery, Vascular Division, ' LAIKON' Hospital, Athens University Medical School (Greece)], E-mail: ctsigris@yahoo.com; Giannopoulos, Athanasios [1st Department of Surgery, Vascular Division, ' LAIKON' Hospital, Athens University Medical School (Greece)], E-mail: dimitrak@mohaw.gr; Bastounis, Elias [1st Department of Surgery, Vascular Division, ' LAIKON' Hospital, Athens University Medical School (Greece)], E-mail: ebastoun@med.uoa.gr

    2008-03-15

    Background and purpose: Speckle Reduction Imaging is a new algorithm that improves the image quality of B-mode scanning by reducing the reverberation artifacts. In the present study the value of this method for the characterization of atherosclerotic plaques in the internal carotid artery was investigated. Methods: Two hundred and twenty two patients (161 men, 61 women; mean age 73 years) referred for carotid ultrasound evaluation were included in the study. Patients with plaques of the internal carotid artery as identified by conventional B-mode scanning were investigated also with the addition of Speckle Reduction Imaging (SRI) with the use of a 4-11-MHz wide band linear transducer. Plaque morphology was rated according to a standardized protocol by two independent observers. Results: For the determination of plaque echogenicity, the reproducibility of SRI ({kappa} = 0.83) was higher than that of conventional B-mode ultrasound ({kappa} = 0.68). The interobserver agreement for plaque surface characterization was also higher for SRI ({kappa} = 0.8) than for conventional B-mode ({kappa} = 0.61). At the evaluation of the image quality through a semiquantitative analysis, SRI was rated superior in the plaque texture resolution, plaque borders determination, vessel wall demarcation and fibrous cap depiction. In addition, the level of 'speckle' was reduced with the use of SRI. Conclusions: SRI is a technique that shows good general agreement with high-resolution B-mode and can be used for the characterization of atherosclerotic plaques in the carotid artery. Furthermore, because this advanced technique allows reduction of ultrasound artifacts, it improves the image quality allowing more precise visualization of plaque morphological details.

  5. Atherosclerotic Aortic Plaques Detected by Transesophageal Echocardiography

    Institute of Scientific and Technical Information of China (English)

    赵云; 朱文玲; 倪超; 郭丽琳; 曾勇; 方理刚

    2002-01-01

    Objective To evaluate the predictive value of atherosclerotic aortic plaques in coronary artery disease (CAD) Methods In 50patients with suspected coronary artery disease, transesophageal echocardiography was performed to examine their thoracic aortas 2 weeks before or after coronary angiography. In the cases of coronary angiography studied, stenosis of the coronary artery ≥ 50 % was considered to be due to coronary artery disease,whereas the thickness of the intima ≥ 1.3 mm was taken to be the criteria for the presence of an atherosclerotic aortic plaque on the transesophageal echocardiographic test. Results Among the 50 patients, 37 cases were diagnosed as CAD and 13 cases were considered to be normal. The plaques of the thoracic aorta were observed in 34cases in the CAD group and 3 cases in the normal group. The sensitivity and specificity of aortic plaques for CAD were 91.9 % and 76.9%, respectively. The positive and negative predictive values of the aortic plaques for CAD were 91.9% and 76.9%, respectively. The accuracy was 88.0%. 80 percent of the patients with single- yes sel disease had thoracic aortic plaques, 92 percent of the patients with two-vessel disease and 100 percent of the patients with three-vessel disease had thoracic aortic plaques. There was a significant difference in the thickness of aortic intimas between the normal group and the CAD group. Conclusions Detectingatherosclerotic plaques in the thoracic aorta with transesophageal echocardiography may be of great value in predicting the presence and extent of coronary artery disease.

  6. MMP-1 and MMP-9 regulate epidermal growth factor-dependent collagen loss in human carotid plaque smooth muscle cells.

    Science.gov (United States)

    Rao, Velidi H; Kansal, Vikash; Stoupa, Samantha; Agrawal, Devendra K

    2014-02-01

    Mechanisms underlying the rupture of atherosclerotic plaque, a crucial factor in the development of myocardial infarction and stroke, are not well defined. Here, we examined the role of epidermal growth factor (EGF)-mediated matrix metalloproteinases (MMP) on the stability of interstitial collagens in vascular smooth muscle cells (VSMCs) isolated from carotid endarterectomy tissues of symptomatic and asymptomatic patients with carotid stenosis. VSMCs isolated from the carotid plaques of both asymptomatic and symptomatic patients were treated with EGF. The MMP-9 activity was quantified by gelatin zymography and the analysis of mRNA transcripts and protein for MMP-9, MMP-1, EGFR and collagen types I, Col I(α1) and collagen type III, Col III(α1) were analyzed by qPCR and immunofluorescence, respectively. The effect of EGF treatment to increase MMP-9 activity and mRNA transcripts for MMP-9, MMP-1, and EGFR and to decrease mRNA transcripts for Col I(α1) and Col III(α1) was threefold to fourfold greater in VSMCs isolated from the carotid plaques of symptomatic than asymptomatic patients. Inhibitors of EGFR (AG1478) and a small molecule inhibitor of MMP-9 decreased the MMP9 expression and upregulated Col I(α1) and Col III(α1) in EGF-treated VSMCs of both groups. Additionally, the magnitude in decreased MMP-9 mRNA and increased Col I(α1) and Col III(α1) due to knockdown of MMP-9 gene with siRNA in EGF-treated VSMCs was significantly greater in the symptomatic group than the asymptomatic group. Thus, a selective blockade of both EGFR and MMP-9 may be a novel strategy and a promising target for stabilizing vulnerable plaques in patients with carotid stenosis.

  7. Cobalt plaque versus enucleation for uveal melanoma: comparison of survival rates.

    OpenAIRE

    Adams, K S; Abramson, D. H.; Ellsworth, R M; Haik, B G; Bedford, M; Packer, S; Seddon, J; Albert, D.; Polivogianis, L

    1988-01-01

    Two hundred and twenty-three patients treated by cobalt plaque for uveal melanoma were compared with 416 patients treated by enucleation for uveal melanoma in terms of patient survival. The median follow-up time for the patients treated by cobalt plaque was 4.3 years. Kaplan-Meier survival curves were calculated up to five years following treatment based on time to tumour-related deaths. Cox's proportional hazards multivariate analysis was performed to determine which variables were related t...

  8. Assessment of dental plaque by optoelectronic methods

    Science.gov (United States)

    Negrutiu, Meda-Lavinia; Sinescu, Cosmin; Bortun, Cristina Maria; Levai, Mihaela-Codrina; Topala, Florin Ionel; Crǎciunescu, Emanuela Lidia; Cojocariu, Andreea Codruta; Duma, Virgil Florin; Podoleanu, Adrian Gh.

    2016-03-01

    The formation of dental biofilm follows specific mechanisms of initial colonization on the surface, microcolony formation, development of organized three dimensional community structures, and detachment from the surface. The structure of the plaque biofilm might restrict the penetration of antimicrobial agents, while bacteria on a surface grow slowly and display a novel phenotype; the consequence of the latter is a reduced sensitivity to inhibitors. The aim of this study was to evaluate with different optoelectronic methods the morphological characteristics of the dental biofilm. The study was performed on samples from 25 patients aged between 18 and 35 years. The methods used in this study were Spectral Domain Optical Coherence Tomography (SD-OCT) working at 870 nm for in vivo evaluations and Scanning Electron Microscopy (SEM) for validations. For each patient a sample of dental biofilm was obtained directly from the vestibular surface of the teeth's. SD-OCT produced C- and B-scans that were used to generate three dimensional (3D) reconstructions of the sample. The results were compared with SEM evaluations. The biofilm network was dramatically destroyed after the professional dental cleaning. OCT noninvasive methods can act as a valuable tool for the 3D characterization of dental biofilms.

  9. Effects of cast gold surface finishing on plaque retention.

    Science.gov (United States)

    Keenan, M P; Shillingburg, H T; Duncanson, M G; Wade, C K

    1980-02-01

    The relationship between the surface finish on cast gold restorations and the amount of plaque deposited on that surface was examined. Six different finishes were tested. The rough finish was found to accumulate significantly less plaque than the other finishes. Every finish exhibited some plaque accumulation, even after the first 24 hours. Each finish accumulated progressively more plaque at each successive time interval.

  10. Meta-analysis of Clinical Efficacy of Chinese Medic ine on Carotid Atherosclerotic Plaque%中医药治疗颈动脉粥样硬化斑块临床疗效的 Meta分析

    Institute of Scientific and Technical Information of China (English)

    刘梨; 龚后武; 张建影; 常小荣

    2015-01-01

    目的:系统评价中医药相关疗法对颈动脉粥样硬化斑块的临床疗效。方法:计算机检索The Co-chrane Library、PubMed、CBM、CNKI、WanFang Data及VIP,收集有关中医药治疗颈动脉粥样硬化斑块的随机对照试验( RCT),检索时限从建库至2014年8月,由两位研究者根据纳入及排除标准独立筛选文献、提取信息及评价纳入文献的方法学质量后,采用软件Rev Man 5.2.9进行Meta分析。结果:最终纳入10个RCT,共计1006例患者,干预措施治疗组为中医药相关疗法,对照组均为常规西药治疗。 Meta分析结果显示:与常规西药用药相比,中医药干预组能显著改善临床证候[OR=2.08,95%CI(1.50,9.55),P=0.004];颈动脉内中膜厚度影响方面,中医药较单纯西药治疗有效,其差异有统计学意义[MD=-0.06,95%CI(-0.10,-0.03),P=0.0006];对降低硬化斑块体积/面积,中医药干预组也较对照组明显( P<0.00001)。结论:在治疗颈动脉粥样硬化斑块方面,中医药干预组的疗效优于常规西药用药组。因纳入研究质量较低,数量所限,故上述结论仍需开展更多大样本高质量的RCT加以验证。%Objective:To evaluate the clinical efficacy of TCM therapy on the carotid atherosclerotic plaque.Methods:Search The Cochrane Library, PubMed, CBM, CNKI, WanFang Data and VIP and collect information of randomized controlled trial ( RCT) about Chinese medicine treatment for carotid atherosclerotic plaque, building a database to re-trieve the time to August 2014 .Two reviewers independently screened the literatures based on inclusion and exclusion criteria,and extracted information and evaluation methods including studies after methodology quality by use of software RevMan 5.2.9 Meta-analysis.Results:Including 10 RCT, totally 1006 cases of patients, the treatment group was trea-ted with interventions of Chinese

  11. 16S rRNA-based detection of oral pathogens in coronary atherosclerotic plaque

    Directory of Open Access Journals (Sweden)

    Mahendra Jaideep

    2010-01-01

    Full Text Available Background: Atherosclerosis develops as a response of the vessel wall to injury. Chronic bacterial infections have been associated with an increased risk for atherosclerosis and coronary artery disease. The ability of oral pathogens to colonize in coronary atheromatous plaque is well known. Aim: The aim of this study was to detect the presence of Treponema denticola, Porphyromonas gingivalis and Campylobacter rectus in the subgingival and atherosclerotic plaques of patients with coronary artery disease. Materials and Methods: Fifty-one patients in the age group of 40-80 years with coronary artery disease were selected for the study. DNA was extracted from the plaque samples. The specific primers for T. denticola, C. rectus and P. gingivalis were used to amplify a part of the 16S rRNA gene by polymerase chain reaction. Statistical Analysis Used: Chi-square analysis, correlation coefficient and prevalence percentage of the microorganisms were carried out for the analysis. Results: Of the 51 patients, T. denticola, C. rectus and P. gingivalis were detected in 49.01%, 21.51% and 45.10% of the atherosclerotic plaque samples. Conclusions: Our study revealed the presence of bacterial DNA of the oral pathogenic microorganisms in coronary atherosclerotic plaques. The presence of the bacterial DNA in the coronary atherosclerotic plaques in significant proportion may suggest the possible relationship between periodontal bacterial infection and genesis of coronary atherosclerosis.

  12. ECG-Gated Three-dimensional Intravascular Ultrasound : Feasibility and Reproducibility of the Automated Analysis of Coronary Lumen and Atherosclerotic Plaque Dimensions in Humans

    NARCIS (Netherlands)

    C. von Birgelen (Clemens); E.A. de Vrey (Evelyn); G.S. Mintz (Gary); A. Nicosia; N. Bruining (Nico); W. Li (Wenguang); P.W.J.C. Serruys (Patrick); P.J. de Feyter (Pim); J.R.T.C. Roelandt (Jos); C.J. Slager (Cornelis)

    1997-01-01

    textabstractBackground Automated systems for the quantitative analysis of three-dimensional (3D) sets of intravascular ultrasound (IVUS) images have been developed to reduce the time required to perform volumetric analyses; however, 3D image reconstruction by these nongated systems is frequently

  13. Optical detection of structural changes in human carotid atherosclerotic plaque

    Science.gov (United States)

    Korol, R. M.; Canham, P. B.; Finlay, H. M.; Hammond, R. R.; Quantz, M.; Ferguson, G. G.; Liu, L. Y.; Lucas, A. R.

    2005-08-01

    Background: Arterial bifurcations are commonly the sites of developing atherosclerotic plaque that lead to arterial occlusions and plaque rupture (myocardial infarctions and strokes). Laser induced fluorescence (LIF) spectroscopy provides an effective nondestructive method supplying spectral information on extracellular matrix (ECM) protein composition, specifically collagen and elastin. Purpose: To investigate regional differences in the ECM proteins -- collagen I, III and elastin in unstable plaque by analyzing data from laser-induced fluorescence spectroscopy of human carotid endarterectomy specimens. Methods: Gels of ECM protein extracts (elastin, collagen types I & III) were measured as reference spectra and internal thoracic artery segments (extra tissue from bypass surgery) were used as tissue controls. Arterial segments and the endarterectomy specimens (n=21) were cut into 5mm cross-sectional rings. Ten fluorescence spectra per sampling area were then recorded at 5 sites per ring with argon laser excitation (357nm) with a penetration depth of 200 μm. Spectra were normalized to maximum intensity and analyzed using multiple regression analysis. Tissue rings were fixed in formalin (within 3 hours of surgery), sectioned and stained with H&E or Movat's Pentachrome for histological analysis. Spectroscopy data were correlated with immunohistology (staining for elastin, collagen types I, III and IV). Results: Quantitative fluorescence for the thoracic arteries revealed a dominant elastin component on the luminal side -- confirmed with immunohistology and known artery structure. Carotid endarterectomy specimens by comparison had a significant decrease in elastin signature and increased collagen type I and III. Arterial spectra were markedly different between the thoracic and carotid specimens. There was also a significant elevation (pcollagen type I distal to the bifurcation compared to proximal tissue in the carotid specimens. Conclusion: Fluorescence spectroscopy

  14. The effect of a chlorhexidine regimen on de novo plaque formation.

    Science.gov (United States)

    Sekino, Satoshi; Ramberg, Per; Uzel, Naciye Guzin; Socransky, Sigmund; Lindhe, Jan

    2004-08-01

    To evaluate the effect of a pretreatment regimen that combined meticulous mechanical tooth cleaning with the daily use of chlorhexidine (rinse, gargle and tongue application) on de novo plaque formation and on the recolonization of various microbiological species in plaque and saliva during a 4-day period of no oral hygiene. Ten subjects aged 24-36 years with gingivitis were recruited. The study was designed as a double blind cross-over clinical trial including two phases. Each experimental phase comprised one preparatory period of 7 days and one plaque accumulation period of 4 days. During the preparatory period, the volunteers (i) performed meticulous mechanical tooth cleaning using toothbrush and dentifrice and (ii) were, in addition, given two sessions of professional tooth cleaning (PTC) The final PTC was delivered after bacterial sampling had been made on Day 0. In the Control group, no additional plaque control measures were included. In the Test group, the participants in addition to the mechanical measures (i) rinsed twice daily, for 60 s each time with a 0.2% chlorhexidine solution, (ii) gargled twice daily for 10 s with the chlorhexidine preparation, and finally (iii) brushed the dorsum of the tongue for 60 s, twice daily, with a 1.0% chlorhexidine gel. During the 4-day plaque accumulation period, the participants abstained from all mechanical and chemical plaque control measures. On Days 0, 1, 2 and 4 the quantity and quality of plaque formed was assessed by clinical means and by DNA probe techniques. The microbiota of the saliva was studied in samples obtained on Days 0 and 4. It was demonstrated that chlorhexidine used as a mouthrinse combined with gargling and tongue application during the preparatory period significantly retarded the amount of plaque that formed on tooth surfaces during the following 4 days of no oral hygiene. Further, the number of microorganisms present in the biofilm representing Days 0, 1 and 2 of the "plaque accumulation period

  15. Fiber-reinforced composite analysis using optical coherence tomography after mechanical and thermal cycling

    Science.gov (United States)

    Kyotoku, B. B. C.; Braz, A. K. S.; Braz, R.; Gomes, A. S. L.

    2007-02-01

    Fiber-reinforced composites are new materials which have been used for a variety of dental applications, including tooth splinting, replacement of missing teeth, treatment of dental emergencies, reinforcement of resin provisional fixed prosthodontic restorations, orthodontic retention, and other clinical applications. Different fiber types are available, but little clinical information has been disseminated. The traditional microscopy investigation, most commonly used to study this material, is a destructive technique, which requires specimen sectioning and are essentially surface measurements. On the basis of these considerations, the aim of this research is to analyze the interior of a dental sample reinforced with fiber after a mechanical and thermal cycling to emulate oral conditions using optical coherence tomography (OCT). The device we are using is a home built Fourier domain OCT working at 800 nm with 6 μm resolution. The results are compared with microscopy images to validate OCT as a working method. In long term, fractures allow bacterial invasion provoking plaque and calculus formation that can cause caries and periodontal disease. Therefore, non invasive imaging of the bridge fiber enables the possibility of periodic clinical evaluation to ensure the patient health. Furthermore, OCT images can provide a powerful method for quantitative analysis of crack propagation, and can potentially be used for in vivo assessment.

  16. The Relationship of Epicardial Fat Volume to Coronary Plaque, Severe Coronary Stenosis, and High-Risk Coronary Plaque Features Assessed by Coronary CT Angiography

    Science.gov (United States)

    Rajani, Ronak; Shmilovich, Haim; Nakazato, Ryo; Nakanishi, Rine; Otaki, Yuka; Cheng, Victor Y.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Slomka, Piotr J.; Min, James K.; Berman, Daniel S.; Dey, Damini

    2013-01-01

    Background Associations of epicardial fat volume (EFV) measured on non-contrast cardiac computed tomography (NCT) include coronary plaque, myocardial ischemia and adverse cardiac events. Objectives This study aimed to define the relationship of EFV to coronary plaque type, severe coronary stenosis, and to the presence of high-risk plaque features (HRPFs). Methods We retrospectively evaluated 402 consecutive patients, with no prior history of coronary artery disease, who underwent same day non-contrast cardiac computed tomography (NCT) and coronary CT angiography (CTA). EFV was measured on NCT using validated, semi-automated, software. The coronary arteries were evaluated for coronary plaque type [calcified (CP), non-calcified (NCP) or partially-calcified (MP)] and coronary stenosis severity ≥70% using coronary CTA. For patients with NCP and PCP, 2 high risk plaque features were evaluated: Low-attenuation plaque and positive remodeling. Results There were 402 patients with a median age of 66 years (range 23–92) of whom 226 (56%) were male. The EFV was larger in patients with CP (112 ± 55 cm3 vs. 89 ± 39 cm3), PCP (110 ± 57 cm3 vs. 98 ± 45 cm3) and NCP (115 ± 44 cm3 vs. EFV 100 ± 52 cm3. In the 192 patients with PCP or NCP, on multivariable analysis, after adjusting for conventional cardiovascular risk factors, EFV was an independent predictor of ≥70% coronary artery stenosis (OR 3.0, 95% CI 1.3–6.6, p=0.008), any high risk plaque features (OR 1.7, 95% CI 0.9–3.4, p=0.04) and low attention plaque (OR 2.4, 95% CI 1.1–5.1, p=0.02), but not of positive remodeling. Conclusions Epicardial fat volume is larger in patients with CP, PCP and NCP. In patients with NCP and PCP, EFV is significantly associated with severe coronary stenosis, high risk plaque features and low attenuation plaque. PMID:23622507

  17. 2-Methacryloyloxyethyl Phosphorylcholine Polymer Treatment of Complete Dentures to Inhibit Denture Plaque Deposition.

    Science.gov (United States)

    Ikeya, Kenji; Fukunishi, Miya; Iwasa, Fuminori; Inoue, Yuuki; Ishihara, Kazuhiko; Baba, Kazuyoshi

    2016-12-26

    Removable dentures made of poly (methyl methacrylate) (PMMA) are prone to bacterial adherence and dental plaque formation, which is called denture plaque. Denture plaque-associated infection is a source of serious dental and medical complications in the elderly. 2-Methacryloyloxyethyl phosphorylcholine (MPC) is a well-known biomedical material that exhibits marked antithrombogenicity and tissue compatibility because of its high resistance to protein adsorption and cell adhesion. Therefore, MPC polymer coatings are suggested to have the potential to inhibit plaque deposition on the surface of PMMA dentures. However, coating MPC polymer on the surface of a PMMA denture is a complex procedure that requires specialized equipment, which is regarded as a major barrier to its clinical application. Here, we introduce a new MPC polymer treatment procedure that uses poly (MPC-co-BMA-co-MPAz) (PMBPAz) to prevent denture plaque deposition on removable dentures. This procedure enables the MPC coating of PMMA denture surfaces in a simple and stable manner that is resistant to various chemical and mechanical stresses due to the MPC layer of PMBPAz that is covalently bound to the PMMA surface by ultraviolet light irradiation. In addition, the procedure does not require any specialized equipment and can be completed by clinicians within 2 min. We applied this procedure in a clinical setting and demonstrated its clinical utility and efficacy in inhibiting plaque deposition on removable dentures.

  18. Differences between Rice Cultivars in Iron Plaque Formation on Roots and Plant Lead Tolerance

    Directory of Open Access Journals (Sweden)

    Xinmei Ma

    2013-02-01

    Full Text Available The aim of this study was to understand some mechanisms on the variations between rice cultivars in lead (Pb tolerance. Pot soil experiments were conducted with two rice cultivars under different soil Pb levels and the relationships between Pb phytotoxicity, uptake and iron plaque formation on roots were investigated. The results showed that the rice cultivar with indica consanguinity (Shanyou 63 were more sensitive to soil Pb stress than the cultivar with japonica consanguinity (Wuyunjing 7, particularly for the roots. Pb concentrations and distribution ratios in root tissues were higher for Shan you 63 than for Wuyunjing 7, but those in the plaques showed a reverse order. Fe distribution ratios in plaques were also larger for Wuyunjing 7 than for Shanyou 63, but the ratios in root tissues showed a reverse order. The results indicate that iron plaque formation on rice roots can provide a barrier to soil Pb stress in Pb-contaminated soils. The plaque will increase the sequestration of Pb on root surface, providing a means of external exclusion of soil Pb. But the function of the plaque is limited, only effective in relatively lower or moderate levels of soil Pb contamination.

  19. Bacterial Communities Associated with Atherosclerotic Plaques from Russian Individuals with Atherosclerosis.

    Science.gov (United States)

    Ziganshina, Elvira E; Sharifullina, Dilyara M; Lozhkin, Andrey P; Khayrullin, Rustem N; Ignatyev, Igor M; Ziganshin, Ayrat M

    2016-01-01

    Atherosclerosis is considered a chronic disease of the arterial wall and is the major cause of severe disease and death among individuals all over the world. Some recent studies have established the presence of bacteria in atherosclerotic plaque samples and suggested their possible contribution to the development of cardiovascular disease. The main objective of this preliminary pilot study was to better understand the bacterial diversity and abundance in human atherosclerotic plaques derived from common carotid arteries of individuals with atherosclerosis (Russian nationwide group) and contribute towards the further identification of a main group of atherosclerotic plaque bacteria by 454 pyrosequencing their 16S ribosomal RNA (16S rRNA) genes. The applied approach enabled the detection of bacterial DNA in all atherosclerotic plaques. We found that distinct members of the order Burkholderiales were present at high levels in all atherosclerotic plaques obtained from patients with atherosclerosis with the genus Curvibacter being predominant in all plaque samples. Moreover, unclassified Burkholderiales as well as members of the genera Propionibacterium and Ralstonia were typically the most significant taxa for all atherosclerotic plaques. Other genera such as Burkholderia, Corynebacterium and Sediminibacterium as well as unclassified Comamonadaceae, Oxalobacteraceae, Rhodospirillaceae, Bradyrhizobiaceae and Burkholderiaceae were always found but at low relative abundances of the total 16S rRNA gene population derived from all samples. Also, we found that some bacteria found in plaque samples correlated with some clinical parameters, including total cholesterol, alanine aminotransferase and fibrinogen levels. Finally, our study indicates that some bacterial agents at least partially may be involved in affecting the development of cardiovascular disease through different mechanisms.

  20. Effect of Manuka honey, chlorhexidine gluconate and xylitol on the clinical levels of dental plaque

    Directory of Open Access Journals (Sweden)

    Prathibha A Nayak

    2010-01-01

    Full Text Available Aims: To compare the effect of Manuka honey, chlorhexidine gluconate (0.2% mouthwash and xylitol chewing gum on the dental plaque levels. Materials and Methods: Sixty healthy male dental students aged between 21 and 25 years (mean age 23.4 years participated in the study. All the subjects received a professional prophylaxis at the start of the study, with the purpose of making the dentition 100% free of plaque and calculus. The subjects were then randomly divided into three groups, i.e. the Manuka honey group, the chlorhexidine gluconate mouthwash group and the xylitol chewing gum group. Rinsing with water or any other fluid after the procedure was not allowed as also any form of mechanical oral hygiene for all the subjects during the experimental period of 72 h. After the experimental period, the plaque was disclosed using disclosing solution and their scores were recorded at six sites per tooth using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Results: The mean plaque scores for Groups I, II and III were 1.37, 1.35 and 1.57, respectively. The ANOVA revealed that between-group comparison was significant, with an F-value of 5.99 and a probability value of 0.004. The T-test was carried out to evaluate the inter-group significance, which revealed that the plaque inhibition by Manuka honey was similar to that of chlorhexidine mouthwash. Both Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly, better than the xylitol chewing gum. Conclusion: Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly better than xylitol chewing gum.

  1. The effect of iron in MRI and transverse relaxation of amyloid-beta plaques in Alzheimer's disease.

    Science.gov (United States)

    Meadowcroft, Mark D; Peters, Douglas G; Dewal, Rahul P; Connor, James R; Yang, Qing X

    2015-03-01

    Dysregulation of neural iron is known to occur during the progression of Alzheimer's disease. The visualization of amyloid-beta (Aβ) plaques with MRI has largely been credited to rapid proton relaxation in the vicinity of plaques as a result of focal iron deposition. The goal of this work was to determine the relationship between local relaxation and related focal iron content associated with Aβ plaques. Alzheimer's disease (n=5) and control tissue (n=3) sample slices from the entorhinal cortex were treated overnight with the iron chelator deferoxamine or saline, and microscopic gradient-echo MRI datasets were taken. Subsequent to imaging, the same slices were stained for Aβ and iron, and then compared with regard to parametric R2 * relaxation maps and gradient-echo-weighted MR images. Aβ plaques in both chelated and unchelated tissue generated MR hypo-intensities and showed relaxation rates significantly greater than the surrounding tissue. The transverse relaxation rate associated with amyloid plaques was determined not to be solely a result of iron load, as much of the relaxation associated with Aβ plaques remained following iron chelation. The data indicate a dual relaxation mechanism associated with Aβ plaques, such that iron and plaque composition synergistically produce transverse relaxation.

  2. Likelihood analysis of earthquake focal mechanism distributions

    CERN Document Server

    Kagan, Y Y

    2014-01-01

    In our paper published earlier we discussed forecasts of earthquake focal mechanism and ways to test the forecast efficiency. Several verification methods were proposed, but they were based on ad-hoc, empirical assumptions, thus their performance is questionable. In this work we apply a conventional likelihood method to measure a skill of forecast. The advantage of such an approach is that earthquake rate prediction can in principle be adequately combined with focal mechanism forecast, if both are based on the likelihood scores, resulting in a general forecast optimization. To calculate the likelihood score we need to compare actual forecasts or occurrences of predicted events with the null hypothesis that the mechanism's 3-D orientation is random. For double-couple source orientation the random probability distribution function is not uniform, which complicates the calculation of the likelihood value. To better understand the resulting complexities we calculate the information (likelihood) score for two rota...

  3. The dental plaque microbiome in health and disease.

    Science.gov (United States)

    Peterson, Scott N; Snesrud, Erik; Liu, Jia; Ong, Ana C; Kilian, Mogens; Schork, Nicholas J; Bretz, Walter

    2013-01-01

    Dental decay is one of the most prevalent chronic diseases worldwide. A variety of factors, including microbial, genetic, immunological, behavioral and environmental, interact to contribute to dental caries onset and development. Previous studies focused on the microbial basis for dental caries have identified species associated with both dental health and disease. The purpose of the current study was to improve our knowledge of the microbial species involved in dental caries and health by performing a comprehensive 16S rDNA profiling of the dental plaque microbiome of both caries-free and caries-active subjects. Analysis of over 50,000 nearly full-length 16S rDNA clones allowed the identification of 1,372 operational taxonomic units (OTUs) in the dental plaque microbiome. Approximately half of the OTUs were common to both caries-free and caries-active microbiomes and present at similar abundance. The majority of differences in OTU's reflected very low abundance phylotypes. This survey allowed us to define the population structure of the dental plaque microbiome and to identify the microbial signatures associated with dental health and disease. The deep profiling of dental plaque allowed the identification of 87 phylotypes that are over-represented in either caries-free or caries-active subjects. Among these signatures, those associated with dental health outnumbered those associated with dental caries by nearly two-fold. A comparison of this data to other published studies indicate significant heterogeneity in study outcomes and suggest that novel approaches may be required to further define the signatures of dental caries onset and progression.

  4. The dental plaque microbiome in health and disease.

    Directory of Open Access Journals (Sweden)

    Scott N Peterson

    Full Text Available Dental decay is one of the most prevalent chronic diseases worldwide. A variety of factors, including microbial, genetic, immunological, behavioral and environmental, interact to contribute to dental caries onset and development. Previous studies focused on the microbial basis for dental caries have identified species associated with both dental health and disease. The purpose of the current study was to improve our knowledge of the microbial species involved in dental caries and health by performing a comprehensive 16S rDNA profiling of the dental plaque microbiome of both caries-free and caries-active subjects. Analysis of over 50,000 nearly full-length 16S rDNA clones allowed the identification of 1,372 operational taxonomic units (OTUs in the dental plaque microbiome. Approximately half of the OTUs were common to both caries-free and caries-active microbiomes and present at similar abundance. The majority of differences in OTU's reflected very low abundance phylotypes. This survey allowed us to define the population structure of the dental plaque microbiome and to identify the microbial signatures associated with dental health and disease. The deep profiling of dental plaque allowed the identification of 87 phylotypes that are over-represented in either caries-free or caries-active subjects. Among these signatures, those associated with dental health outnumbered those associated with dental caries by nearly two-fold. A comparison of this data to other published studies indicate significant heterogeneity in study outcomes and suggest that novel approaches may be required to further define the signatures of dental caries onset and progression.

  5. Mechanical vibration and shock analysis, sinusoidal vibration

    CERN Document Server

    Lalanne, Christian

    2014-01-01

    Everything engineers need to know about mechanical vibration and shock...in one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to m

  6. DECT evaluation of noncalcified coronary artery plaque

    Energy Technology Data Exchange (ETDEWEB)

    Ravanfar Haghighi, Rezvan [Medical Imaging Research Center and Colorectal Research Center, Shiraz University of Medical Science, Shiraz 719 363 5899 (Iran, Islamic Republic of); Chatterjee, S. [BGVS Chemical Engineering Building (Old), Indian Institute of Science, Bangalore 560012 (India); Tabin, Milo; Singh, Rishi P.; Sharma, Munish; Krishna, Karthik [Department of Forensic Medicine, All India Institute of Medical Sciences, New Delhi 110029 (India); Sharma, Sanjiv; Jagia, Priya [Department of Cardiac-Radiology, All India Institute of Medical Sciences, New Delhi 110029 (India); Ray, Ruma; Arava, Sudhir [Department of Pathology, All India Institute of Medical Sciences, New Delhi 110029 (India); Yadav, Rakesh [Department of Cardiology, All India Institute of Medical Sciences, New Delhi 110029 (India); Vani, V. C. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India); Lakshmi, R.; Kumar, Pratik, E-mail: drpratikkumar@gmail.com [Department of Cardiac-Biochemistry, All India Institute of Medical Sciences, New Delhi 110029 (India); Mandal, Susama R. [Department of Medical Physics Unit IRCH, All India Institute of Medical Sciences, New Delhi 110029 (India)

    2015-10-15

    Purpose: Composition of the coronary artery plaque is known to have critical role in heart attack. While calcified plaque can easily be diagnosed by conventional CT, it fails to distinguish between fibrous and lipid rich plaques. In the present paper, the authors discuss the experimental techniques and obtain a numerical algorithm by which the electron density (ρ{sub e}) and the effective atomic number (Z{sub eff}) can be obtained from the dual energy computed tomography (DECT) data. The idea is to use this inversion method to characterize and distinguish between the lipid and fibrous coronary artery plaques. Methods: For the purpose of calibration of the CT machine, the authors prepare aqueous samples whose calculated values of (ρ{sub e}, Z{sub eff}) lie in the range of (2.65 × 10{sup 23} ≤ ρ{sub e} ≤ 3.64 × 10{sup 23}/cm{sup 3}) and (6.80 ≤ Z{sub eff} ≤ 8.90). The authors fill the phantom with these known samples and experimentally determine HU(V{sub 1}) and HU(V{sub 2}), with V{sub 1},V{sub 2} = 100 and 140 kVp, for the same pixels and thus determine the coefficients of inversion that allow us to determine (ρ{sub e}, Z{sub eff}) from the DECT data. The HU(100) and HU(140) for the coronary artery plaque are obtained by filling the channel of the coronary artery with a viscous solution of methyl cellulose in water, containing 2% contrast. These (ρ{sub e}, Z{sub eff}) values of the coronary artery plaque are used for their characterization on the basis of theoretical models of atomic compositions of the plaque materials. These results are compared with histopathological report. Results: The authors find that the calibration gives ρ{sub e} with an accuracy of ±3.5% while Z{sub eff} is found within ±1% of the actual value, the confidence being 95%. The HU(100) and HU(140) are found to be considerably different for the same plaque at the same position and there is a linear trend between these two HU values. It is noted that pure lipid type plaques

  7. Assessment of carotid plaque composition using fast-kV switching dual-energy CT with gemstone detector: comparison with extracorporeal and virtual histology-intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Yuki; Kuya, Keita; Ohta, Yasutoshi; Fujii, Shinya; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Yonago (Japan); Sakamoto, Makoto; Watanabe, Takashi [Tottori University, Division of Neurosurgery, Department of Neurological Sciences, Faculty of Medicine, Yonago (Japan); Kishimoto, Junichi; Iwata, Naoki [Tottori University Hospital, Division of Clinical Radiology, Yonago (Japan)

    2015-09-15

    The present study compares the applicability of CT carotid plaque imaging using effective Z maps using gemstone spectral imaging (GSI) with that of conventional extracorporeal carotid ultrasound (US) and virtual histology-intravascular ultrasound (VH-IVUS). We assessed stenosis in 31 carotid arteries of 30 patients. All patients underwent carotid CTA using GSI (Discovery CT750 HD, GE Healthcare). US and IVUS were examined with 25 and 8 vessels, respectively. We compared the effective Z values at noncalcified carotid plaque with the plaque components identified by US. We defined the plaque with low or low to iso intensity on US as vulnerable plaque and the plaque with iso, iso to high, and high intensity on US as stable plaque. We also performed visual assessment of color-coded effective Z maps in comparison with VH-IVUS and compared effective Z values with plaque components generated by VH-IVUS. The effective Z values at noncalcified carotid plaque were significantly lower for a group with vulnerable plaque, than with stable plaque on US (p < 0.05). Receiver operating curve analysis showed that AUC of effective Z values was 0.882 concerning the differentiation of these two groups on US. The interpretation of color-coded effective Z maps was essentially compatible with that of VH-IVUS for carotid plaque in all vessels. Effective Z values at noncalcified plaque showed significant negative correlation with the areas of fibro-fatty components generated by VH-IVUS (ρ = -0.874, p < 0.05). Effective Z maps generated by GSI can detect vulnerable carotid plaque materials. (orig.)

  8. Local effects of atherosclerotic plaque on arterial distensibility.

    Science.gov (United States)

    Giannattasio, C; Failla, M; Emanuelli, G; Grappiolo, A; Boffi, L; Corsi, D; Mancia, G

    2001-11-01

    common carotid artery. This provides evidence that the effect of a plaque on arterial mechanical properties is not limited to the actual plaque site but rather extends to a considerable degree in a proximal direction.

  9. Regression of atherosclerosis is characterized by broad changes in the plaque macrophage transcriptome.

    Directory of Open Access Journals (Sweden)

    Jonathan E Feig

    Full Text Available We have developed a mouse model of atherosclerotic plaque regression in which an atherosclerotic aortic arch from a hyperlipidemic donor is transplanted into a normolipidemic recipient, resulting in rapid elimination of cholesterol and monocyte-derived macrophage cells (CD68+ from transplanted vessel walls. To gain a comprehensive view of the differences in gene expression patterns in macrophages associated with regressing compared with progressing atherosclerotic plaque, we compared mRNA expression patterns in CD68+ macrophages extracted from plaque in aortic aches transplanted into normolipidemic or into hyperlipidemic recipients. In CD68+ cells from regressing plaque we observed that genes associated with the contractile apparatus responsible for cellular movement (e.g. actin and myosin were up-regulated whereas genes related to cell adhesion (e.g. cadherins, vinculin were down-regulated. In addition, CD68+ cells from regressing plaque were characterized by enhanced expression of genes associated with an anti-inflammatory M2 macrophage phenotype, including arginase I, CD163 and the C-lectin receptor. Our analysis suggests that in regressing plaque CD68+ cells preferentially express genes that reduce cellular adhesion, enhance cellular motility, and overall act to suppress inflammation.

  10. Quantification of Canine Dental Plaque Using Quantitative Light-Induced Fluorescence.

    Science.gov (United States)

    Wallis, Corrin; Gill, Yadvinder; Colyer, Alison; Davis, Ian; Allsopp, Judi; Komarov, Gleb; Higham, Susan; Harris, Stephen

    2016-03-01

    The aim of this work was to evaluate Quantitative Light-induced Fluorescence (QLF) as an alternative to the established Logan and Boyce method for determining plaque coverage of dogs' teeth. In a series of studies in conscious and anesthetized dogs, QLF showed good intra-photographer repeatability (coefficient of variation [CV] of 7.5% for undisclosed teeth) and inter-photographer reproducibility (CV of 3.2% for undisclosed teeth and 8.5% for disclosed teeth). The QLF software accurately identifies areas of plaque as demonstrated by comparison to the variability of 5 human scorers, manually marking plaque on QLF-acquired images (P = 0.1). There was good agreement with the modified Logan and Boyce method in the percentage reduction in plaque accumulation measured when dogs were fed an oral care chew versus no chew. To see a 15% difference in plaque accumulation, which is considered sufficient by the Veterinary Oral Health Council to differentiate between 2 treatments, a retrospective power analysis (90%) of the data established that only 7 dogs would be required, compared to 19 dogs for the modified Logan and Boyce method. QLF is a reliable method for measuring dental plaque in dogs with the added advantage that it is not subjective and requires fewer animals.

  11. The risk factors associated with ultrasonic tissue characterization of carotid plaque in type 2 diabetic patients.

    Science.gov (United States)

    Irie, Yoko; Katakami, Naoto; Kaneto, Hideaki; Takahara, Mitsuyoshi; Sakamoto, Ken'ya; Kosugi, Keisuke; Shimomura, Iichiro

    2014-01-01

    Little is known about the related factors of plaque echogenicity in diabetic subjects. This was a single-center, retrospective, study investigating a subgroup of patients of a previously published trial. We enrolled 179 middle-aged and older Japanese type 2 diabetic patients with carotid plaque, and examined the parameters related with echogenicity of carotid plaque evaluated by gray-scale median (GSM). Proportion of males and body mass index (BMI) were significantly higher and HDL-cholesterol was significantly lower in the patients with low GSM (HDL-cholesterol as independent variables and the presence of low GSM plaques as an objective variable showed that male (odds ratio (OR) 2.36, 95%CI 1.05-5.31, p = 0.037) and BMI (OR 1.12 [1.01-1.24], p = 0.029) were independently associated with low GSM plaques. Another multiple logistic regression analysis with gender, BMI, and low-HDL-cholesterolemia (HDL-C HDL-cholesterolemia (OR 2.30 [1.03-5.13], p = 0.042) and BMI (OR 1.11 [1.00-1.22], p = 0.046) were independently associated with low GSM plaques. Our study suggests that gender, BMI and low-HDL-cholesterol are important determinants of the content of the vascular wall in diabetic subjects. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Vulnerable Plaque Detection and Quantification with Gold Particle–Enhanced Computed Tomography in Atherosclerotic Mouse Models

    Directory of Open Access Journals (Sweden)

    David De Wilde

    2015-06-01

    Full Text Available Recently, an apolipoprotein E–deficient (ApoE−/− mouse model with a mutation (C1039G+/− in the fibrillin-1 (Fbn1 gene (ApoE−/−Fbn1C1039G+/− mouse model was developed showing vulnerable atherosclerotic plaques, prone to rupture, in contrast to the ApoE−/− mouse model, where mainly stable plaques are present. One indicator of plaque vulnerability is the level of macrophage infiltration. Therefore, this study aimed to measure and quantify in vivo the macrophage infiltration related to plaque development and progression. For this purpose, 5-weekly consecutive gold nanoparticle–enhanced micro–computed tomography (microCT scans were acquired. Histology confirmed that the presence of contrast agent coincided with the presence of macrophages. Based on the microCT scans, regions of the artery wall with contrast agent present were calculated and visualized in three dimensions. From this information, the contrast-enhanced area and contrast-enhanced centerline length were calculated for the branches of the carotid bifurcation (common, external, and internal carotid arteries. Statistical analysis showed a more rapid development and a larger extent of plaques in the ApoE−/−Fbn1C1039G+/− compared to the ApoE−/− mice. Regional differences between the branches were also observable and quantifiable. We developed and applied a methodology based on gold particle–enhanced microCT to visualize the presence of macrophages in atherosclerotic plaques in vivo.

  13. Non-plaque-induced gingival lesions

    DEFF Research Database (Denmark)

    Holmstrup, P

    1999-01-01

    The origin of gingival inflammation is occasionally different from that of routine plaque-associated gingivitis, and such non-plaque-associated types of gingivitis often present characteristic clinical features. Examples of such forms of gingivitis are specific bacterial, viral, and fungal......, a confirmed diagnosis may require histopathologic examination and/or culture. Atypical gingivitis may also occur as gingival manifestations of dermatological diseases, the most relevant of these being lichen planus, pemphigoid, pemphigus vulgaris, erythema multiforme, and lupus erythematosus. Non-plaque......, the most important of these being Candida species including C. albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis, and C. guillermondii. Gingival histoplasmosis is a granulomatous disease caused by the fungus Histoplasma capsulatum and, as for the other specific infections of gingiva...

  14. Plaque rupture in humans and mice

    DEFF Research Database (Denmark)

    Schwartz, Stephen M; Galis, Zorina S; Rosenfeld, Michael E

    2007-01-01

    Despite the many studies of murine atherosclerosis, we do not yet know the relevance of the natural history of this model to the final events precipitated by plaque disruption of human atherosclerotic lesions. The literature has become particularly confused because of the common use of terms...... such as "instability", "vulnerable", "rupture", or even "thrombosis" for features of plaques in murine model systems not yet shown to rupture spontaneously and in an animal surprisingly resistant to formation of thrombi at sites of atherosclerosis. We suggest that use of conclusory terms like "vulnerable" and "stable...... that various forms of data have implicated in plaque progression. For example, formation of the fibrous cap, protease activation, and cell death in the necrotic core can be well described and have all been modeled in well-defined experiments. The relevance of such well-defined, objective, descriptive...

  15. PLACD-7T Study: Atherosclerotic Carotid Plaque Components Correlated with Cerebral Damage at 7 Tesla Magnetic Resonance Imaging.

    Science.gov (United States)

    den Hartog, A G; Bovens, S M; Koning, W; Hendrikse, J; Pasterkamp, G; Moll, F L; de Borst, G J

    2011-02-01

    In patients with carotid artery stenosis histological plaque composition is associated with plaque stability and with presenting symptomatology. Preferentially, plaque vulnerability should be taken into account in pre-operative work-up of patients with severe carotid artery stenosis. However, currently no appropriate and conclusive (non-) invasive technique to differentiate between the high and low risk carotid artery plaque in vivo is available. We propose that 7 Tesla human high resolution MRI scanning will visualize carotid plaque characteristics more precisely and will enable correlation of these specific components with cerebral damage. The aim of the PlaCD-7T study is 1: to correlate 7T imaging with carotid plaque histology (gold standard); and 2: to correlate plaque characteristics with cerebral damage ((clinically silent) cerebral (micro) infarcts or bleeds) on 7 Tesla high resolution (HR) MRI. We propose a single center prospective study for either symptomatic or asymptomatic patients with haemodynamic significant (70%) stenosis of at least one of the carotid arteries. The Athero-Express (AE) biobank histological analysis will be derived according to standard protocol. Patients included in the AE and our prospective study will undergo a pre-operative 7 Tesla HR-MRI scan of both the head and neck area. We hypothesize that the 7 Tesla MRI scanner will allow early identification of high risk carotid plaques being associated with micro infarcted cerebral areas, and will thus be able to identify patients with a high risk of periprocedural stroke, by identification of surrogate measures of increased cardiovascular risk.

  16. Plaque control evaluation of a stabilized stannous fluoride dentifrice compared to a triclosan dentifrice in a six-week trial.

    Science.gov (United States)

    Sharma, N; He, T; Barker, M L; Biesbrock, A R

    2013-01-01

    To compare the anti-plaque efficacy of a stabilized 0.454% stannous fluoride (referred to as SnF2) dentifrice versus a 0.3% triclosan dentifrice formulated with a copolymer and sodium fluoride (referred to as triclosan). The study had a randomized, double-blind, two-treatment, parallel-group design, and compared plaque reduction from baseline after both three and six weeks of treatment with either the SnF2 or triclosan dentifrices using a manual toothbrush. Subjects brushed their teeth using their assigned treatment dentifrices according to the manufacturer's instructions. Following overnight plaque accumulation, levels of plaque were assessed by an experienced examiner using the Rustogi, et al. Modified Navy Plaque Index at the start of the study (baseline), and after three and six weeks of regular brushing. Groups were compared using analysis of covariance separately for Weeks 3 and 6, and by repeated measures for Weeks 3 and 6 combined. One-hundred and twenty subjects were randomized to treatment and 114 subjects completed the study. Both treatment groups showed a statistically significant reduction from baseline in mean plaque values for all three tooth areas (whole mouth, gingival margin, interproximal) at both Weeks 3 and 6 (p dentifrices showed statistically significant reductions from baseline in whole mouth, gumline, and interproximal accumulated overnight plaque after three and six weeks of brushing, but the SnF2 dentifrice showed statistically significantly greater plaque reductions versus the triclosan dentifrice.

  17. 急性冠脉综合征患者 mTOR活性及 CD71表达率与斑块性质的相关性%Analysis of the correlation among mTOR activation and CD71 expression frequencies and plaque nature in acute coronary syndrome patient

    Institute of Scientific and Technical Information of China (English)

    张艳; 胡春玲; 刘慧华; 李志樑

    2014-01-01

    目的:研究急性冠脉综合征( ACS)患者T细胞中哺乳动物雷帕霉素靶蛋白( mTOR)活性与转铁蛋白受体( CD71)以及斑块性质的相关性。方法采用免疫印迹试验( Western blot)及流式细胞术( FACS)分别检测ACS组、稳定性心绞痛(SAP)组以及胸痛综合征(CPS)对照组患者T细胞内p70S6K磷酸化水平( p-p70S6K)及CD4+CD71+/CD4+表达比率,血管内超声( IVUS)检查斑块性质,分析两者之间的关系。结果 ACS患者 p-p70S6K 表达量及 CD4+CD71+/CD4+表达比率均显著高于 SAP 及对照组( P<0.01);不稳定性斑块组中上述2种指标值均显著高于稳定性斑块组(P<0.01);相关性分析示不稳定斑块中斑块负荷与p-p70S6K表达量及CD4+CD71+/CD4+细胞比率均呈正相关( r=0.93,r=0.92,P<0.05);p-p70S6K表达量与CD4+CD71+/CD4+细胞比率亦呈正相关(r=0.91,P<0.05)。结论 mTOR 活性与CD71表达率升高及ACS中斑块不稳定性密切相关。%Objective To investigate the correlation among mTOR activation, CD71 expression frequencies and plaque nature in acute coronary syndrome(ACS)patient.Methods The expression of phospho-p70S6K ( indicative of mTORC activity ) by western blot and CD4+CD71+/CD4+ frequencies by fluorescence activated cell sorter(FACS),plaque nature by intravascular ultrasound (IVUS)were analyzed in T cells isolated from peripheral blood of ACS,stable angina pectoris(SAP)or chest pain syndrome (CPS)patients. Then we investigated the correlation among mTOR activation, CD71 expression frequencies and plaque nature by correlation analysis. Results The expressions of p-p70S6K and the frequencies of CD4+CD71+/CD4+ were significantly increased in ACS group as compared with SAP and CPS control groups( P<0.01) , and the above two indexes were also significantly increased in unstable plaque than those in stable plaque (P<0.01).By correlation analysis,the plaque burden in unstable plaque as measured with IVUS correlated positively with the p-p70S6K

  18. Cobalt60 plaques in recurrent retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Fass, D.; McCormick, B.; Abramson, D.; Ellsworth, R. (Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, NY, NY (USA))

    1991-08-01

    Cobalt60 plaque irradiation is one treatment option for patients with recurrent retinoblastoma following conventional external beam irradiation (ERT). Tumorocidal doses can be delivered without excessive risk of normal tissue injury. In patients not considered candidates for xenon arc or cryotherapy, 60Co is an alternative to enucleation. Between 1968 and 1987, 85 patients were treated with 60Co plaques, 72 of whom had failed prior ERT. Age at diagnosis ranged from 1 week to 4 years. There are 37 males and 35 females. Seventy-one patients had bilateral disease and one had unilateral. Three patients had both eyes plaqued. Prior ERT ranged from 30 to 70 Gy (mean 4200 Gy). Time from initial therapy to failure ranged from 13 to 60 months. Cobalt plaques of 10 mm, 15 mm, or 10 {times} 15 mm were used depending on tumor size and location. Dose prescribed to the apex of the tumor ranged from 30 to 50 Gy (median 40 Gy) given over 3 to 8 days. Twelve patients had two plaque applications; three patients had three plaque applications. All patients were followed with routine ophthalmoscopic examinations. Follow-up ranged from 2 to 22 years (mean 8.7). Seven patients died of metastatic disease; 10 patients developed non-ocular second tumors. Thirty patients required enucleation. Twenty-two patients had clear tumor progression, two patients had radiation complications, and six patients had a combination of tumor growth and complications. Cobalt60 can salvage eyes in retinoblastoma patients failing ERT. Currently, the authors are using I125 in an attempt to spare normal ocular tissue and reduce subsequent complications.

  19. An analysis on the Risk Factors of Carotid Artery Atherosclerotic Plaques in Cerebral Infarction Patients%脑梗死患者颈动脉粥样硬化斑块的相关因素分析

    Institute of Scientific and Technical Information of China (English)

    王本孝; 许平

    2011-01-01

    Objective:To explore the risk factors for carotid artery atherosclerotic plaques in cerebral infarction patients. Methods: Color doppler ultrasound scanner was used to detect the plaques of the carotid arteries in patients with cerebral infarction (n=126) and normal controls (n=61). According to the doppler ultrasound scanning, the patients were divided into plaque (+) group (n=102) and plaque(—) group (n=24). The patients in the plaque(+) group were further divided into stable plaque (n=35) and unstable plaque subgroups (n=67). The physical data and the concentration of total cholesterol(TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A (ApoA),apolipoprotein B (ApoB), lipoprotein-a (Lp(a)), fibrinogen (FIB) and blood glucose (BG) were measured, and compared between the groups. Results: Carotid atherosclerotic artery plaques were detected in 80.9% of the patients, which was significantly higher than that in the normal controls (P<0.01). When compared with those in plaque(—) group, those patients were much older. Smoking, hypertension, diabetes, higher concentrations of TC, Lp(a), ApoB, FIB, LDLC, and BG were more frequently found in the plaque(+) group. The FIB concentrations of patients in the unstable plaque subgroup was much higher that in the stable plaque subgroup (P<0.05). Conclusion: Carotid atherosclerotic plaques were the risk factor for cerebral infarction.Old age, smoking, hypertention, diabetes mellitus, lipoidosis, and high fibrinogen are the risk factors for carotid atherosclerotic plaques. High concentration of fibrinogen affects stability of the plaques.%目的:探讨脑梗死患者颈动脉粥样硬化斑块形成及其稳定性的相关影响因素.方法:应用彩色多普勒超声检测脑梗死患者126例及正常对照者61例颈动脉斑块形成情况;根据超声检查结果将126例脑梗死患者分为有斑块组102

  20. PORPHYROMONAS GINGIVALIS IN CORONARY ATHEROMA AND SUBGINGIVAL PLAQUE – A CLINICAL AND MICROBIOLOGICAL STUDY

    Directory of Open Access Journals (Sweden)

    Col S K

    2014-01-01

    Full Text Available BACKGROUND : There has been increasing attention paid in recent years to the possibility that oral bacterial infection, particularly periodontal disease may influence the initiation and or progression of systemic diseases. These studies confirm the observation that hea rt disease is the most commonly found systemic condition in patients with periodontal disease. Moreover, the literature has also highlighted substantial evidence indicating the presence of gram negative periodontal pathogens in atheromatous plaques. AIMS : The present study intends to investigate the possible association between periodontal health and coronary artery disease by evaluating periodontal status, association between the periodontal plaque and coronary atheromatous plaques for presence of P.ging ivalis. SETTINGS AND DESIGN : A case control study was designed with 07 patients who had underwent coronary endarterectomy for CVD and 28 controls . The periodontal examination for cases was performed one day before vascular surgery and t he controls we re clinically examined. METHODS AND MATERIAL : The atheromatous plaque sample collected during endarterectomy and the Intraoral plaque samples were subjected to PCR for identification of P.gingivalis. The presence of periodontal bacteria DNA in coronary atheromatous plaques and subgingival plaque samples of the same patients was confirmed by this study. STATISTICAL ANALYSIS USED : Means and proportions for personal characters, major risk factors and c linical parameters were calculated for both the groups. The significance of any difference in means was tested by using “Students t test”, and the significance of any difference in proportions was tested by using Dunn - Sidak Adjusted p Value. RESULTS : D uring the microbial analysis of plaque samples by PCR in group A it was seen that Porphyromonas gingivalis in 100 % of the samples . Microbial analysis of endarterectomy samples by PCR in group A shows that Porphyromonas

  1. Tribology analysis of chemical-mechanical polishing

    Energy Technology Data Exchange (ETDEWEB)

    Runnels, S.R.; Eyman, L.M. (Sematech, Austin, TX (United States))

    1994-06-01

    To better understand the variation of material removal rate on a wafer during chemical-mechanical polishing (CMP), knowledge of the stress distribution on the wafer surface is required. The difference in wafer-surface stress distributions could be considerable depending on whether or not the wafer hydroplanes during polishing. This study analyzes the fluid film between the wafer and pad and demonstrates that hydroplaning is possible for standard CMP processes. The importance of wafer curvature, slurry viscosity, and rotation speed on the thickness of the fluid film is also demonstrated.

  2. Analysis on mechanism of land resource security

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper probes into the relationship among individual benefits, benefits of the country, common benefits of all humans in land use and land resource security. The following balanced land use model is proposed: the harmonious and interactive relationship between man and nature, two main bodies of land ecological system, constitutes the mechanism of land resources security. The feedback relationship between man and nature is the basis for the land resources security and the core is the relationship among people established for the benefit equilibrium in land use. The conflicts, in land use stem from the rarity of land resource and the solution to those conflicts in harmony helps land resource security.

  3. Analysis of Mechanical Properties for GEM Foil

    CERN Document Server

    Chin, Yuk Ming

    2016-01-01

    In view of new assembly technique of the GEM detector; in which three foils stack is stretched to get the uniform gaps among the foils. We studied the mechanical properties of the foil material. We conditioned the samples in different environments to make them extra dry and wet. As holes are the major source of the charge amplification their deformation can effect the detector performance. Therefore in our studies we also studied at which level of the stress the holes deformation is seen. These tensile and holes deformation studies can help to optimize the stress during detector assembly.

  4. Kinematics Analysis of Two Parallel Locomotion Mechanisms

    Science.gov (United States)

    2010-08-27

    world. Many thanks to Dr. Mehdi Ahmandian, Dr. Corina Sandu, Dr. Robert Sturges and Dr. Bob West. As my committee members, you have given me...128(3), pp. 566-573. [47] Mcgeer, T., 1990, "Passive Dynamic Walking," International Journal of Robotics Research, 9(2), pp. 62-82. [48] Spong , M...Locomotion Robot," Proc. 31st ASME Mechanisms and Robotics Conference, Las Vegas, NV, United States, 8 PART B, pp. 1001-1011. [53] Spong , M. W., and

  5. Performance Analysis for Dispensing Mechanism of Active Code

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The dispensing mechanism of active code is a key technology in an active network. Conventional capsule and programmable switch approaches have their own shortcomings. The DCCAN(distributed code caching for active network) mechanism presented in this paper overcomes these shortcomings. In this paper, capsule and programmable switch approaches are introduced, and their shortcomings are analyzed. The principle of the DCCAN mechanism is described. The theory analysis in transmit width based on the DCCAN mechanism and capsule approach are described. The theory analysis shows that the DCCAN mechanism has many good characteristics and can improve the efficiency of an active network. Key factors which affect the transmit width based on the DCCAN mechanism are discussed. The using condition of the DCCAN mechanism is also discussed.

  6. System reliability analysis for kinematic performance of planar mechanisms

    Institute of Scientific and Technical Information of China (English)

    ZHANG YiMin; HUANG XianZhen; ZHANG XuFang; HE XiangDong; WEN BangChun

    2009-01-01

    Based on the reliability and mechanism kinematic accuracy theories, we propose a general methodology for system reliability analysis of kinematic performance of planar mechanisms. The loop closure equations are used to estimate the kinematic performance errors of planar mechanisms. Reliability and system reliability theories are introduced to develop the limit state functions (LSF) for failure of kinematic performance qualities. The statistical fourth moment method and the Edgeworth series technique are used on system reliability analysis for kinematic performance of planar mechanisms, which relax the restrictions of probability distribution of design variables. Finally, the practicality, efficiency and accuracy of the proposed method are demonstrated by numerical examples.

  7. Recognition and Analysis of Corrosion Failure Mechanisms

    OpenAIRE

    Steven Suess

    2006-01-01

    Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, materi...

  8. Recognition and Analysis of Corrosion Failure Mechanisms

    OpenAIRE

    Steven Suess

    2006-01-01

    Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, materi...

  9. Analysis of WWER 1000 collector cracking mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Matocha, K.; Wozniak, J. [Vitkovice J.S.C., Ostrava (Switzerland)

    1997-12-31

    The presentation reviews the large experimental program, started in 1993 in Vitkovice, where the main aim was: (1) a detailed study of strain and thermal ageing, dissolved oxygen content and temperature on subcritical crack growth in 10NiMo8.5 (10GN2MFA) steel, (2) a detailed study of the effect of high temperature water and tube expansion technology on fracture behaviour of ligaments between holes for heat exchange tubes, and (3) a detailed study of the effect of drilling, tube expansion technology and heat treatment on residual stresses on the surface of holes for heat exchange tubes. The aim of all these investigations was to find a dominant damage mechanism responsible for collector cracking to be able to judge the efficiency of implemented modifications and suggested countermeasures and to answer a very important question whether proper operation conditions (mainly water chemistry) make the operation of steam generators made in Vitcovice safe throughout the planned lifetime. 10 refs.

  10. Kinematical Analysis of an Articulated Mechanism

    CERN Document Server

    Fleischfresser, Luciano

    2015-01-01

    The purpose of this work is twofold: to present mathematical expressions for the kinematics of an articulated mechanism and to perform numerical experiments with the implemented Fortran code. The system of rigid parts is made of two slender bars and a disk. A constant 2 rad/s counterclockwise rotation rate is imposed on the disk triggering the planar motion of the longer bar (link) and the rotation of the shorter one (output). Angular relations, velocities and accelerations are analyzed for a 90-degree turn of the disk. The inversion of the linking bar sense of rotation is well captured by the simulation, and the paper and pencil solutions that may lead to wrong conclusions are explained. Equations are derived from first principles and the Fortran code is placed under version control (currently, v.0.8-beta). This computer project is relevant for those in charge of vector dynamics courses and wishing to expose students to project-based learning activities.

  11. Alzheimer's Protein Plaques May Also Harm the Heart

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162241.html Alzheimer's Protein Plaques May Also Harm the Heart Deposits ... fragments that form plaques in the brains of Alzheimer's patients might also stiffen their heart muscle and ...

  12. Plaque retention on elastomeric ligatures. An in vivo study

    OpenAIRE

    CONDÒ, R.; CASAGLIA, A.; CONDÒ, S.G.; Cerroni, L

    2013-01-01

    Fixed orthodontic appliances make it difficult to maintain the oral hygiene, resulting in plaque accumulation. Retention of bacterial plaque, represents a risk for white spot lesions and development of periodontal disease.

  13. Infliximab for the treatment of plaque psoriasis

    Directory of Open Access Journals (Sweden)

    Jennifer S Gall

    2008-03-01

    Full Text Available Jennifer S Gall, Robert E KalbState University of New York at Buffalo, School of Medicine and Biomedical Sciences, Department of Dermatology, NY, USAAbstract: Infliximab is a monoclonal antibody that targets tumor necrosis factor-α (TNFα. It is used in the treatment of a number of inflammatory disorders including severe plaque psoriasis. TNFα is thought to have a major role in psoriasis by promoting an inflammatory infiltrate into the skin and inducing keratinocyte proliferation and preventing keratinocyte apoptosis, which directly contributes to the characteristic plaque skin lesions. Based on four randomized, placebo-controlled, double-blind clinical trials and nine open-label uncontrolled trials of the use of infliximab in plaque psoriasis, it was found that infliximab is a highly efficacious, rapid, sustainable, and relatively safe therapy. Yet as with any biologic, caution is recommended in its use as infusion reactions, lupus-like syndromes, infections, malignancies including lymphomas, as well as other rare events have been reported.Keywords: infliximab, psoriasis, plaque

  14. Large plaque parapsoriasis in a child

    Directory of Open Access Journals (Sweden)

    Das Jayanta

    2005-01-01

    Full Text Available A case of large plaque parapsoriasis with extensive skin lesions is presented for its unusual clinical features. The controversial issue of its nosological position is discussed as it has a considerable impact on the management of such cases.

  15. Intracoronary Thermography: a vulnerable Plaque Detection Technique?

    NARCIS (Netherlands)

    A.G. ten Have (Anna)

    2006-01-01

    textabstractThe studies reported in this thesis were performed to answer the central question: can intracoronary thermography be used for vulnerable plaque detection? To answer this question, we have identified parameters that influence intracoronary thermography measurements, and have studied to w

  16. Vaporization of atherosclerotic plaques by spark erosion

    NARCIS (Netherlands)

    C.J. Slager (Cornelis); C.E. Essed; J.C.H. Schuurbiers (Johan); N. Bom (Klaas); P.W.J.C. Serruys (Patrick); G.T. Meester (Geert)

    1985-01-01

    textabstractAn alternative to the laser irradiation of atherosclerotic lesions has been developed. A pulsed electrocardiogram R wave-triggered electrical spark erosion technique is described. Controlled vaporization of fibrous and lipid plaques with minimal thermal side effects was achieved and docu

  17. Mathematical models for atherosclerotic plaque evolution

    NARCIS (Netherlands)

    Bulelzai, M.A.K.

    2013-01-01

    Atherosclerosis is a disease in which low density lipoproteins (LDL) accumulate in the arterial wall due to an inflammatory response, which is triggered by the oxidation of LDL molecules that are already present in the arterial wall. Progression of atherosclerotic plaques involves many components wh

  18. Digitate dermatosis (small-plaque parapsoriasis).

    Science.gov (United States)

    Lewin, Jesse; Latkowski, Jo-Ann

    2012-12-15

    We report a 79-year-old man with a 15-year history of elongated, finger-like, erythematous patches that are symmetrically distributed on his flanks and of small, parapsoriasis, which is a benign entity that has been the center of controversy over the years, owing to its similarities to large-plaque parapsoriasis, which is on a spectrum with mycosis fungoides.

  19. Retroperitoneal liposarcoma associated with small plaque parapsoriasis

    OpenAIRE

    Polichetti Paolo; Sgueglia Monica; Blasi Sara; Tartaglia Francesco; Tromba Luciana; Berni Alberto

    2007-01-01

    Abstract Background Extremely rare cases of paraneoplastic syndromes or ectopic production of proteins associated with liposarcoma are reported in literature. Production of Granulocyte-Colony Stimulating Factor, alpha-fetoprotein, paraneoplastic pemphigus and leucocytosis, Acrokeratosis paraneoplastica (Bazex's syndrome) are reported. The present report describes a case of retroperitoneal liposarcoma associated with small plaque parapsoriasis. Our search in the English literature of such a ki...

  20. Adalimumab: A Review in Chronic Plaque Psoriasis.

    Science.gov (United States)

    Burness, Celeste B; McKeage, Kate

    2015-12-01

    Adalimumab (Humira(®)) is a fully human monoclonal antibody against tumour necrosis factor (TNF), formulated for subcutaneous administration. It is well established in the treatment of adults with moderate-to-severe chronic plaque psoriasis and has recently received approval in the EU for the treatment of severe chronic plaque psoriasis in children and adolescents from 4 years of age. In a phase III trial in paediatric patients, a significantly greater proportion of patients receiving adalimumab 0.8 mg/kg (to a maximum of 40 mg) every other week (eow) achieved a ≥75 % improvement from baseline in Psoriasis Area and Severity Index than those receiving methotrexate after 16 weeks of treatment. In adults, well-designed randomized clinical trials demonstrated that adalimumab 40 mg eow effectively reduced the signs and symptoms of psoriasis and improved dermatology-specific and general measures of health-related quality of life, with these benefits sustained during long-term treatment. Adalimumab was generally well tolerated, compared with placebo or methotrexate, during clinical trials in paediatric and adult patients with chronic plaque psoriasis. Thus, adalimumab remains an important treatment strategy in adults with moderate-to-severe chronic plaque psoriasis and provides a promising new systemic treatment option for children and adolescents from 4 years of age with severe psoriasis.

  1. Plaques of Nonstenotic Basilar Arteries with Isolated Pontine Infarction on Three-dimensional High Isotropic Resolution Magnetic Resonance Imaging

    Institute of Scientific and Technical Information of China (English)

    Xian-Jin Zhu; Wei-Jian Jiang; Lei Liu; Li-Bin Hu; Wu Wang; Zun-Jing Liu

    2015-01-01

    Background:There are few studies for evaluating plaque characteristics of nonstenotic basilar arteries (BA).Our aim was to determine entire BA plaques with a three-dimensional volumetric isotropic turbo spin-echo acquisition (VISTA) and investigate the differences between the patients with and without isolated pontine infarction (IPI).Methods:Twenty-four consecutive symptomatic patients with nonstenotic BA on time of flight magnetic resonance angiography (TOF MRA) were enrolled from China-Japan Friendship Hospital between January 2014 and December 2014.BA was classified as "normal" or"irregular" based on TOF MRA,and "normal wall","slight wall-thickening",and "plaque" based on three-dimensional VISTA images.Outcomes from MRA and VISTA were compared.Patients were categorized as IPI and non-IPI groups based on the diffusion-weighted imaging.Clinical and plaque characteristics were compared between the two groups.Results:A total of 1024 image slices including 311 (30.37%) plaque slices,427 (41.70%) slight wall-thickening slices,and 286 (27.93%) normal wall slices for the entire BA from 23 patients were finally included for analysis.VISTA images detected plaques in all the 9 (100%) irregular MRA patients and 7 of 14 (50%) normal MRA patients.IPI was found in 1 1 (47.83%) patients.Compared to non-IPI group,the IPI group had a higher percentage of plaque slices (P =0.001) and lower percentage of normal wall slices (P =0.014) than non-IPI group.Conclusions:Three-dimensional VISTA images enable detection of BA plaques not visualized by MRA.BA plaques could be found in both the IPI and non-IPI group.However,IPI group showed plaques more extensively in BA than the non-IPI group.

  2. Effect of Guanxinshutong capsule on the expression of matrix metalloproteinases-9 and tissue matrix metalloproteinase inhibitor-1 of atherosclerotic plaque in apoE-/- mice

    Institute of Scientific and Technical Information of China (English)

    霍煜

    2014-01-01

    Objective To approach the possible mechanism of Guanxinshutong capsule on the progression and stability of atherosclerotic plaque through observing the effects of Guanxinshutong capsule on pathologic morphology and expression of tissue matrix metalloproteinase inhibitor-1(TIMP-1),matrix metalloproteinases-9(MMP-9)of atherosclerotic plaque in Apo E-/-mice model with experimental atherosclerosis.Methods The animals were fed

  3. Outcomes of Iodine-125 Plaque Brachytherapy for Uveal Melanoma With Intraoperative Ultrasonography and Supplemental Transpupillary Thermotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Badiyan, Shahed N. [Department of Radiation Oncology, Mallinckrodt Institute of Radiology, St. Louis, Missouri (United States); Rao, Rajesh C. [Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri (United States); Apicelli, Anthony J.; Acharya, Sahaja; Verma, Vivek; Garsa, Adam A.; DeWees, Todd; Speirs, Christina K.; Garcia-Ramirez, Jose; Esthappan, Jacqueline; Grigsby, Perry W. [Department of Radiation Oncology, Mallinckrodt Institute of Radiology, St. Louis, Missouri (United States); Harbour, J. William, E-mail: JWHarbour@med.miami.edu [Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri (United States); Ocular Oncology Service, Department of Ophthalmology, Bascom Palmer Eye Institute and Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida (United States)

    2014-03-15

    Purpose: To assess the impact on local tumor control of intraoperative ultrasonographic plaque visualization and selective application of transpupillary thermotherapy (TTT) in the treatment of posterior uveal melanoma with iodine-125 (I-125) episcleral plaque brachytherapy (EPB). Methods and Materials: Retrospective analysis of 526 patients treated with I-125 EPB for posterior uveal melanoma. Clinical features, dosimetric parameters, TTT treatments, and local tumor control outcomes were recorded. Statistical analysis was performed using Cox proportional hazards and Kaplan-Meier life table method. Results: The study included 270 men (51%) and 256 women (49%), with a median age of 63 years (mean, 62 years; range, 16-91 years). Median dose to the tumor apex was 94.4 Gy (mean, 97.8; range, 43.9-183.9) and to the tumor base was 257.9 Gy (mean, 275.6; range, 124.2-729.8). Plaque tilt >1 mm away from the sclera at plaque removal was detected in 142 cases (27%). Supplemental TTT was performed in 72 patients (13.7%). One or 2 TTT sessions were required in 71 TTT cases (98.6%). After a median follow-up of 45.9 months (mean, 53.4 months; range, 6-175 months), local tumor recurrence was detected in 19 patients (3.6%). Local tumor recurrence was associated with lower dose to the tumor base (P=.02). Conclusions: Ultrasound-guided plaque localization of I-125 EPB is associated with excellent local tumor control. Detection of plaque tilt by ultrasonography at plaque removal allows supplemental TTT to be used in patients at potentially higher risk for local recurrence while sparing the majority of patients who are at low risk. Most patients require only 1 or 2 TTT sessions.

  4. Oxidized LDL in carotid plaques and plasma associates with plaque instability

    National Research Council Canada - National Science Library

    Nishi, Kyoko; Itabe, Hiroyuki; Uno, Masaaki; Kitazato, Keiko T; Horiguchi, Hidehisa; Shinno, Kiyohito; Nagahiro, Shinji

    2002-01-01

    Oxidation of LDL plays a significant pathogenic role in atherosclerosis. In this study, we attempted to clarify the correlation between the morphology of human atherosclerotic plaques and the oxidized LDL (OxLDL...

  5. Histiocytoid Sweet's syndrome presenting with annular erythematous plaques*

    Science.gov (United States)

    Marcarini, Renata; de Araujo, Raquel Nardelli; Nóbrega, Monisa Martins; Medeiros, Karina Bittencourt; Gripp, Alexandre Carlos; Maceira, Juan Manuel Piñeiro

    2016-01-01

    Histiocytoid Sweet's Syndrome is a rare inflammatory disease described in 2005 as a variant of the classical Sweet's Syndrome (SS). Histopathologically, the dermal inflammatory infiltrate is composed mainly of mononuclear cells that have a histiocytic appearance and represent immature myeloid cells. We describe a case of Histiocytoid Sweet's Syndrome in an 18-year-old man. Although this patient had clinical manifestations compatible with SS, the cutaneous lesions consisted of erythematous annular plaques, which are not typical for this entity and have not been described in histiocytic form so far. The histiocytic subtype was confirmed by histopathological analysis that showed positivity for myeloperoxidase in multiple cells with histiocytic appearance.

  6. Analysis and control of underactuated mechanical systems

    CERN Document Server

    Choukchou-Braham, Amal; Djemaï, Mohamed; Busawon, Krishna

    2014-01-01

    This monograph provides readers with tools for the analysis, and control of systems with fewer control inputs than degrees of freedom to be controlled, i.e., underactuated systems. The text deals with the consequences of a lack of a general theory that would allow methodical treatment of such systems and the ad hoc approach to control design that often results, imposing a level of organization whenever the latter is lacking. The authors take as their starting point the construction of a graphical characterization or control flow diagram reflecting the transmission of generalized forces through the degrees of freedom. Underactuated systems are classified according to the three main structures by which this is found to happen—chain, tree, and isolated vertex—and control design procedures proposed. The procedure is applied to several well-known examples of underactuated systems: acrobot; pendubot; Tora system; ball and beam; inertia wheel; and robotic arm with elastic joint. The text is illustrated with MATL...

  7. Core Backbone Convergence Mechanisms and Microloops Analysis

    Directory of Open Access Journals (Sweden)

    Abdelali Ala

    2012-07-01

    Full Text Available In this article we study approaches that can be used to minimise the convergence time, we also make a focus on microloops phenomenon, analysis and means to mitigate them. The convergence time reflects the time required by a network to react to a failure of a link or a router failure itself. When all nodes (routers have updated their respective routing and forwarding databases, we can say the network has converged. This study will help in building real-time and resilient network infrastructure, the goal is to make any evenement in the core network, as transparent as possible to any sensitive and real-time flows. This study is also, a deepening of earlier works presented in [10] and [11].

  8. Inflamed psoriatic plaques: Drug toxicity or disease exacerbation?

    Directory of Open Access Journals (Sweden)

    Nidhi Jindal

    2013-01-01

    Full Text Available We are presenting a case of Methotrexate treated stable plaque psoriasis, in whom inflamed psoriatic plaques of drug toxicity were misdiagnosed as disease exacerbation. Erosive psoriatic plaques were present in the absence of biochemical or hematological derangements. Ulceration of psoriatic plaques in the presence of disturbed hematological profile is well described as a harbinger of methotrexate toxicity, but this kind of erosions in the absence of any systemic involvement is the first report of its kind.

  9. Analytical kinematics analysis and synthesis of planar mechanisms

    CERN Document Server

    Gans, Deborah

    2013-01-01

    Using computational techniques and a complex variable formulation, this book teaches the student of kinematics to handle increasingly difficult problems in both the analysis and design of mechanisms all based on the fundamental loop closure equation.

  10. Analysis of soft rock roadway deformation mechanism in Zhangshuanglou Mine

    Institute of Scientific and Technical Information of China (English)

    顾士亮

    2003-01-01

    On basis of ground stress surveying and analysis of physical nature and mechanics character of rock, the deformation mechanism of west main roadway in Zhangshuanglou Mine is studied. It is put forward that engineering mechanics nature, infiltration of water and concentrated stress on pillar are the main factors to affect stability of the west main roadway. The overall thinking used to restore the roadway is raised.

  11. Carotid Magnetic Resonance Imaging A Window to Study Atherosclerosis and Identify High-Risk Plaques

    National Research Council Canada - National Science Library

    Oikawa, Minako; Ota, Hideki; Takaya, Norihide; Miller, Zach; Hatsukami, Thomas S; Yuan, Chun

    2009-01-01

    ...: the so-called "vulnerable plaque". A reliable, in vivo, imaging method capable of identifying plaque characteristics associated with high-risk plaque will be immensely useful for evaluating plaque status and predicting future events...

  12. Three-dimensional carotid ultrasound plaque texture predicts vascular events

    DEFF Research Database (Denmark)

    van Engelen, Arna; Wannarong, Thapat; Parraga, Grace;

    2014-01-01

    carotid plaque volume and 376 measures of plaque texture. Patients were followed up to 5 years (median [range], 3.12 [0.77-4.66]) for myocardial infarction, transient ischemic attack, and stroke. Sparse Cox regression was used to select the most predictive plaque texture measurements in independent...

  13. En plaque meningioma in thoracic spine: case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyeon Seon; Kang, Ho Yeong; Yoon, Deug Hee; Jo, Byung June; Lee, Sang Ho; Choi, Young Geun [Wooridul Spine Hospital, Seoul (Korea, Republic of); Lee, Sang Yeun [Puchon Daesung Hospital, Puchon (Korea, Republic of)

    2005-07-15

    Spinal en plaque meningioma is rarely found in the spinal canal, although lateral sphenoid wing meningioma displays a propensity for growth en plaque. We encountered a case of completely circumferential spinal en plaque meningioma, which is an even rarer condition. Herein, we report the CT MRI findings along with a review of the related literature.

  14. The Preliminary Analysis of Microflora in Dental Plaque of Twin Children by PCR-DGGE%PCR-DGGE初步分析双胞胎儿童牙菌斑细菌群落组成

    Institute of Scientific and Technical Information of China (English)

    陆剑; 相艳; 李宇红; 杜民权

    2012-01-01

    目的:应用PCR-DGGE技术对双胞胎儿童牙菌斑细菌群落组成进行初步分析.方法:牙菌斑样本取自6对双胞胎儿童,年龄3.5~5.5岁,共17份.分别提取细菌总DNA,PCR扩增16S rDNA V3可变区,产物经DGGE指纹图谱分析其组成.结果:DGGE图谱显示,无龋和患龋双胞胎儿童牙菌斑菌属分布存在差异.结论:PCR-DGGE技术可较直观、灵敏地反应牙菌斑菌属的组成情况.%Objective: To detect bacterial community in dental plaque of twin children by PCR-DGGE. Methods: A total of 17 samples were collected from 6 twins. PCR - based denaturing gradient gel electrophoresis surveys mi-crobial diversity by displaying PCR-generated 16S rDNA V3 fragment that migrate at different distances, reflecting the differences sequence of the fragment. Result: DGGE fingerprint patterns of dental plaque samples showed variation among them. Conclusion: PCR-DGGE method is a sensitive and effective approach to resolve the microflora structure of dental plaque.

  15. Analysis of Frequency Characteristics and Sensitivity of Compliant Mechanisms

    Institute of Scientific and Technical Information of China (English)

    LIU Shanzeng; DAI Jiansheng; LI Aimin; SUN Zhaopeng; FENG Shizhe; CAO Guohua

    2016-01-01

    Based on a modified pseudo-rigid-body model, the frequency characteristics and sensitivity of the large-deformation compliant mechanism are studied. Firstly, the pseudo-rigid-body model under the static and kinetic conditions is modified to enable the modified pseudo-rigid-body model to be more suitable for the dynamic analysis of the compliant mechanism. Subsequently, based on the modified pseudo-rigid-body model, the dynamic equations of the ordinary compliant four-bar mechanism are established using the analytical mechanics. Finally, in combination with the finite element analysis software ANSYS, the frequency characteristics and sensitivity of the compliant mechanism are analyzed by taking the compliant parallel-guiding mechanism and the compliant bistable mechanism as examples. From the simulation results, the dynamic characteristics of compliant mechanism are relatively sensitive to the structure size, section parameter, and characteristic parameter of material on mechanisms. The results could provide great theoretical significance and application values for the structural optimization of compliant mechanisms, the improvement of their dynamic properties and the expansion of their application range.

  16. Analysis of frequency characteristics and sensitivity of compliant mechanisms

    Science.gov (United States)

    Liu, Shanzeng; Dai, Jiansheng; Li, Aimin; Sun, Zhaopeng; Feng, Shizhe; Cao, Guohua

    2016-07-01

    Based on a modified pseudo-rigid-body model, the frequency characteristics and sensitivity of the large-deformation compliant mechanism are studied. Firstly, the pseudo-rigid-body model under the static and kinetic conditions is modified to enable the modified pseudo-rigid-body model to be more suitable for the dynamic analysis of the compliant mechanism. Subsequently, based on the modified pseudo-rigid-body model, the dynamic equations of the ordinary compliant four-bar mechanism are established using the analytical mechanics. Finally, in combination with the finite element analysis software ANSYS, the frequency characteristics and sensitivity of the compliant mechanism are analyzed by taking the compliant parallel-guiding mechanism and the compliant bistable mechanism as examples. From the simulation results, the dynamic characteristics of compliant mechanism are relatively sensitive to the structure size, section parameter, and characteristic parameter of material on mechanisms. The results could provide great theoretical significance and application values for the structural optimization of compliant mechanisms, the improvement of their dynamic properties and the expansion of their application range.

  17. Topographic association of angioscopic yellow plaques with coronary atherosclerotic plaque: assessment with quantitative colorimetry in human coronary artery autopsy specimens.

    Science.gov (United States)

    Ishibashi, Fumiyuki; Lisauskas, Jennifer B; Kawamura, Akio; Waxman, Sergio

    2008-01-01

    Yellow plaques seen during coronary angioscopy are thought to be the surrogates for superficial intimal lipids in coronary plaque. Given diffuse and heterogeneous nature of atherosclerosis, yellow plaques in coronaries may be seen as several yellow spots on diffuse coronary plaque. We examined the topographic association of yellow plaques with coronary plaque. In 40 non-severely stenotic ex-vivo coronary segments (average length: 52.2 +/- 3.1 mm), yellow plaques were examined by angioscopy with quantitative colorimetry. The segments were cut perpendicular to the long axis of the vessel at 2 mm intervals, and 1045 slides with 5 microm thick tissue for whole segments were prepared. To construct the plaque surface, each tissue slice was considered to be representative of the adjacent 2 mm. The circumference of the lumen and the lumen border of plaque were measured in each slide, and the plaque surface region was constructed. Coronary plaque was in 37 (93%) of 40 segments, and consisted of a single mass [39.9 +/- 3.9 (0-100) mm, 311.3 +/- 47.4 (0.0-1336.2) mm2]. In 30 (75%) segments, multiple (2-9) yellow plaques were detected on a mass of coronary plaque. The number of yellow plaques correlated positively with coronary plaque surface area (r = 0.77, P colorimetry, some of them are associated with lipid cores underneath thin fibrous caps, may be used to assess the extent of coronary plaque. Further research using angioscopy could be of value to study the association of high-risk coronaries with acute coronary syndromes.

  18. Randomized digital plaque imaging trial evaluating plaque inhibition efficacy of a novel stabilized stannous fluoride dentifrice compared with an amine fluoride/stannous fluoride dentifrice.

    Science.gov (United States)

    Bellamy, P G; Boulding, A; Farmer, S; Day, T N; Mussett, A J; Barker, M L

    2012-01-01

    To assess the plaque inhibition efficacy ofa novel 0.454% stabilized stannous fluoride test dentifrice (SnF2) to an amine fluoride/stannous fluoride marketed control dentifrice (AmF/SnF2) using digital plaque imaging analysis (DPIA). The 10-week study was a randomized, two-treatment, three-period, double-blind crossover design. Subjects brushed twice daily with their assigned dentifrice (SnF2 or AmF/SnF2) using a standard manual toothbrush during three treatment periods each lasting 17 days, separated by four-day washout periods. DPIA was used to analyze plaque coverage on facial surfaces of the 12 anterior teeth (canine to canine) by three assessments on Days 15, 16, and 17 at the end of each treatment period. Assessments were conducted the morning following no overnight brushing of facial surfaces (A.M. pre-brush), after 40 seconds of full mouth brushing with the assigned dentifrice (A.M. post-brush), and during the afternoon (P.M.). Twenty-seven subjects were randomized and completed the study. At each assessment time point, plaque levels for the SnF2 dentifrice were statistically significantly lower compared to those for the AmF/SnF2 dentifrice (21.4%, 22.6%, 24.3%, respectively; p dentifrice than with the AmF/SnF2 dentifrice. The plaque control benefits of the SnF2 dentifrice seen at the morning and afternoon time points indicated significantly better inhibition of plaque re-growth.

  19. Male Gender and Arterial Hypertension are Plaque Predictors at Coronary Computed Tomography Angiography

    Science.gov (United States)

    Oliveira, Joselina Luzia Menezes; Hirata, Mario Hiroyuki; Sousa, Amanda Guerra de Moraes Rego; Gabriel, Fabíola Santos; Hirata, Thiago Dominguez Crespo; Tavares, Irlaneide da Silva; Melo, Luiza Dantas; Dória, Fabiana de Santana; Sousa, Antônio Carlos Sobral; Pinto, Ibraim Masciarelli Francisco

    2015-01-01

    Background Systemic Arterial Hypertension (SAH) is one of the main risk factors for Coronary Artery Disease (CAD), in addition to male gender. Differences in coronary artery lesions between hypertensive and normotensive individuals of both genders at the Coronary Computed Tomography Angiography (CCTA) have not been clearly determined. Objective To Investigate the calcium score (CS), CAD extent and characteristics of coronary plaques at CCTA in men and women with and without SAH. Methods Prospective cross-sectional study of 509 patients undergoing CCTA for CAD diagnosis and risk stratification, from November 2011 to December 2012, at Instituto de Cardiologia Dante Pazzanese. Individuals were stratified according to gender and subdivided according to the presence (HT +) or absence (HT-) of SAH. Results HT+ women were older (62.3 ± 10.2 vs 57.8 ± 12.8, p = 0.01). As for the assessment of CAD extent, the HT+ individuals of both genders had significant CAD, although multivessel disease is more frequent in HT + men. The regression analysis for significant CAD showed that age and male gender were the determinant factors of multivessel disease and CS ≥ 100. Plaque type analysis showed that SAH was a predictive risk factor for partially calcified plaques (OR = 3.9). Conclusion Hypertensive men had multivessel disease more often than women. Male gender was a determinant factor of significant CAD, multivessel disease, CS ≥ 100 and calcified and partially calcified plaques, whereas SAH was predictive of partially calcified plaques. PMID:25861034

  20. Characteristic detected on computed tomography angiography predict coronary artery plaque progression in non-culprit lesions

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Ya Hang; Zhou, Jia Zhou; Zhou, Ying; Yang, Xiaobo; Yang, Jun Jie; Chen, Yun Dai [Dept. of Cardiology, Chinese PLA General Hospital, Beijing (China)

    2017-06-15

    This study sought to determine whether variables detected on coronary computed tomography angiography (CCTA) would predict plaque progression in non-culprit lesions (NCL). In this single-center trial, we analyzed 103 consecutive patients who were undergoing CCTA and percutaneous coronary intervention (PCI) for culprit lesions. Follow-up CCTA was scheduled 12 months after the PCI, and all patients were followed for 3 years after their second CCTA examination. High-risk plaque features and epicardial adipose tissue (EAT) volume were assessed by CCTA. Each NCL stenosis grade was compared visually between two CCTA scans to detect plaque progression, and patients were stratified into two groups based on this. Logistic regression analysis was used to evaluate the factors that were independently associated with plaque progression in NCLs. Time-to-event curves were compared using the log-rank statistic. Overall, 34 of 103 patients exhibited NCL plaque progression (33%). Logistic regression analyses showed that the NCL progression was associated with a history of ST-elevated myocardial infarction (odds ratio [OR] = 5.855, 95% confidence interval [CI] = 1.391–24.635, p = 0.016), follow-up low-density lipoprotein cholesterol level (OR = 6.832, 95% CI = 2.103–22.200, p = 0.001), baseline low-attenuation plaque (OR = 7.311, 95% CI = 1.242–43.028, p = 0.028) and EAT (OR = 1.015, 95% CI = 1.000–1.029, p = 0.044). Following the second CCTA examination, major adverse cardiac events (MACEs) were observed in 12 patients, and NCL plaque progression was significantly associated with future MACEs (log rank p = 0.006). Noninvasive assessment of NCLs by CCTA has potential prognostic value.

  1. Kinematic analysis of a flexible six-DOF parallel mechanism.

    Science.gov (United States)

    Jing, Feng-Shui; Tan, Min; Hou, Zeng-Guang; Liang, Zi-Ze; Wang, Yun-Kuan; Gupta, Madan M; Nikiforuk, Peter N

    2006-04-01

    In this paper, a new type of six-degrees of freedom (DOF) flexible parallel mechanism (FPM) is presented. This type of parallel mechanism possesses several favorable properties: (1) its number of DOFs is independent of the number of serial chains which make up the mechanism; (2) it has no kinematical singularities; (3) it is designed to move on rails, and therefore its workspace is much larger than that of a conventional parallel manipulator; and (4) without changing the number of DOFs and the kinematics of the mechanisms, the number of the serial chains can be reconfigured according to the needs of the tasks. These properties make the mechanism very preferable in practice, especially for such tasks as joining huge ship blocks, in which the manipulated objects vary dramatically both in weights and dimensions. Furthermore, the mechanism can be used as either a fully actuated system or an underactuated system. In the fully actuated case, the mechanism has six DOF motion capabilities and manipulation capabilities. However, in the underactuated case, the mechanism still has six DOF motion capabilities, but it has only five DOF manipulation capabilities. In this paper, both the inverse and forward kinematics are studied and expressed in a closed form. The workspace and singularity analysis of the mechanism are also presented. An example is presented to illustrate how to calculate the kinematics of the mechanism in both fully-actuated and underactuated cases. Finally, an application of such a mechanism to manufacturing industry is introduced.

  2. Ultrasound Vascular Elastography as a Tool for Assessing Atherosclerotic Plaques

    DEFF Research Database (Denmark)

    Mahmood, Badar; Ewertsen, C; Carlsen, Jørn

    2016-01-01

    to distinguish between vulnerable and stable plaques. The aim of this paper is to provide an overview of the literature on vascular elastography. A systematic search of the available literature for studies using elastography for assessing atherosclerotic plaques was conducted using the MEDLINE, Embase, Cochrane...... compared to B-mode ultrasound alone. Most studies reported higher strain values for vulnerable plaques. Ultrasound elastography has potential as a clinical tool in the assessment of atherosclerotic plaques. Elastography is able to distinguish between different plaque types, but there is considerable...

  3. The efficacy of honey solution as plaque reducing agent

    Directory of Open Access Journals (Sweden)

    Dewi Nurul M

    2010-06-01

    Full Text Available Background: Periodontal care is an important step of periodontal health management. Some chemically active substances have been studied as an adjunct to mechanical plaque control. Honey is a traditional topical treatment for infected wounds and have inhibitory effect to around 60 species of bacteria including aerobes and anaerobes, gram-positives and gram-negatives. Purpose: To compare the efficacy of 5% and 25% honey solution and aquadest as mouth-rinses to control dental plaque during 4 days period. Method: After a thorough prophylaxis, during 4 days period of no oral hygiene all subjects were rinsed with 10 ml mouth-rinse they received 3 times a day after meal. Group I rinse with 5% honey solution, group II with 25%, and group III with aquadest as control. Results: There were significant increases of plaque index within each group, but no differences between all three groups in every experimental day. The fact that the probability value from day 1 (0.766 were gradually decreased to day 4 (0.076. Conclusion: Anti-microbial properties of honey solution as mouth-rinse did not show any inhibition effect on plaque formation until day 4.Latar belakang: Menjaga kesehatan periodontal merupakan tahap penting dalam pemeliharaan kesehatan periodontal. Beberapa substansi kimiawi aktif telah diteliti untuk membantu dalam kontrol plak gigi secara mekanik. Madu merupakan obat tradisional untuk luka terinfeksi dan dinyatakan mempunyai pengaruh menghambat sekitar 60 spesies termasuk bakteri aerob dan anaerob gram positif dan gram negatif. Tujuan: Membandingkan manfaat larutan madu 5% dan 25% terhadap akuades sebagai obat kumur untuk mengontrol pembentukan plak gigi selama 4 hari penelitian. Metode: Setelah tindakan profilaksis pembersihan sempurna, semua subjek penelitian dipersilahkan berkumur dengan 10 ml larutan yang telah diterima, 3 kali sehari setelah makan. Kelompok 1 berkumur dengan larutan madu 5%, kelompok 2 dengan 25%, dan kelompok 3 dengan akuades

  4. Back analysis of mechanical parameters of roller compacted concrete dam

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam displacements.During the process of back analysis,the initial samples of parameters were designed with uniform design method.Then,a transversely isotropic model of RCCD was established by MSC.Marc software.Through this model,training samples of LSSVM model could be obtained.And then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was established.Finally,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using PLS.By inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be obtained.The example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

  5. Hygro-Thermo-Mechanical Analysis of a Reactor Vessel

    Directory of Open Access Journals (Sweden)

    Jaroslav Kruis

    2012-01-01

    Full Text Available Determining the durability of a reactor vessel requires a hygro-thermo-mechanical analysis of the vessel throughout its service life. Damage, prestress losses, distribution of heat and moisture and some other quantities are needed for a durability assessment. A coupled analysis was performed on a two-level model because of the huge demands on computer hardware. This paper deals with a hygro-thermo-mechanical analysis of a reactor vessel made of prestressed concrete with a steel inner liner. The reactor vessel is located in Temelín, Czech Republic.

  6. Simultaneous amplification of two bacterial genes: more reliable method of Helicobacter pylori detection in microbial rich dental plaque samples.

    Science.gov (United States)

    Chaudhry, Saima; Idrees, Muhammad; Izhar, Mateen; Butt, Arshad Kamal; Khan, Ayyaz Ali

    2011-01-01

    Polymerase Chain reaction (PCR) assay is considered superior to other methods for detection of Helicobacter pylori (H. pylori) in oral cavity; however, it also has limitations when sample under study is microbial rich dental plaque. The type of gene targeted and number of primers used for bacterial detection in dental plaque samples can have a significant effect on the results obtained as there are a number of closely related bacterial species residing in plaque biofilm. Also due to high recombination rate of H. pylori some of the genes might be down regulated or absent. The present study was conducted to determine the frequency of H. pylori colonization of dental plaque by simultaneously amplifying two genes of the bacterium. One hundred dental plaque specimens were collected from dyspeptic patients before their upper gastrointestinal endoscopy and presence of H. pylori was determined through PCR assay using primers targeting two different genes of the bacterium. Eighty-nine of the 100 samples were included in final analysis. With simultaneous amplification of two bacterial genes 51.6% of the dental plaque samples were positive for H. pylori while this prevalence increased to 73% when only one gene amplification was used for bacterial identification. Detection of H. pylori in dental plaque samples is more reliable when two genes of the bacterium are simultaneously amplified as compared to one gene amplification only.

  7. Prevalence and factors associated with scleral hyaline plaque: clinical study of older adults in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Horowitz S

    2015-06-01

    Full Text Available Soraya Horowitz,1 Nadyr Damasceno,1 Eduardo Damasceno21Department of Ophthalmology, Hospital Naval Marcilio Dias, Rio de Janeiro, 2Department of Ophthalmology, Universidade Federal Fluminense, Niterói, BrazilPurpose: To investigate the prevalence of scleral hyaline plaque among older adults in the city of Niterói in southeastern Brazil. A second goal was to assess the correlation between scleral hyaline plaque and several age-related diseases, including eye diseases and systemic diseases.Methods: The study sample comprised 667 participants who were followed for 15 months. The study had a prospective, longitudinal, observational design that established inclusion and exclusion criteria. The following variables were selected for correlation with scleral hyaline plaque: sex, age, age range, iris color, ethnicity, presence of cataract, moderate to high myopia, age-related macular degeneration (AMD, diabetes mellitus, systemic arterial hypertension, degenerative arthritis, and osteoporosis. These correlations were assessed by means of the χ2 test and Student’s t-test. Multivariate analysis was performed to exclude factors that were potentially associated with aging exclusively but that did not have a direct relationship with hyaline plaque. Binary logistic regression was used to calculate odds ratios, significance, and confidence intervals.Results: Scleral hyaline plaques were found in 177 patients (17.54%. There was a statistically significant association between the presence of hyaline plaques and sex (female, age range (≥70 years old, ethnicity (Caucasian, cataract, moderate to high myopia, systemic arterial hypertension, degenerative arthritis, and osteoporosis (P<0.05. On multivariate binary logistic regression analysis, only female sex, age range (≥70 years, moderate to high myopia, and degenerative arthritis exhibited significant correlation.Conclusion: The prevalence of scleral hyaline plaque in the present study was higher than in

  8. Dual-mode ultrasound arrays for image-guided targeting of atheromatous plaques

    Science.gov (United States)

    Ballard, John R.; Casper, Andrew J.; Liu, Dalong; Haritonova, Alyona; Shehata, Islam A.; Troutman, Mitchell; Ebbini, Emad S.

    2012-11-01

    A feasibility study was undertaken in order to investigate alternative noninvasive treatment options for atherosclerosis. In particular, the aim of this study was to investigate the potential use of Dual-Mode Ultrasound Arrays (DMUAs) for image guided treatment of atheromatous plaques. DMUAs offer a unique treatment paradigm for image-guided surgery allowing for robust image-based identification of tissue targets for localized application of HIFU. In this study we present imaging and therapeutic results form a 3.5 MHz, 64-element fenestrated prototype DMUA for targeting lesions in the femoral artery of familial hypercholesterolemic (FH) swine. Before treatment, diagnostic ultrasound was used to verify the presence of plaque in the femoral artery of the swine. Images obtained with the DMUA and a diagnostic (HST 15-8) transducer housed in the fenestration were analyzed and used for guidance in targeting of the plaque. Discrete therapeutic shots with an estimated focal intensity of 4000-5600 W/cm2 and 500-2000 msec duration were performed at several planes in the plaque. During therapy, pulsed HIFU was interleaved with single transmit focus imaging from the DMUA and M2D imaging from the diagnostic transducer for further analysis of lesion formation. After therapy, the swine's were recovered and later sacrificed after 4 and 7 days for histological analysis of lesion formation. At sacrifice, the lower half of the swine was perfused and the femoral artery with adjoining muscle was fixed and stained with H&E to characterize HIFU-induced lesions. Histology has confirmed that localized thermal lesion formation within the plaque was achieved according to the planned lesion maps. Furthermore, the damage was confined to the plaque tissue without damage to the intima. These results offer the promise of a new treatment potentially suited for vulnerable plaques. The results also provide the first real-time demonstration of DMUA technology in targeting fine tissue structures for

  9. Bacterial diversity and community structure of supragingival plaques in adults with dental health or caries revealed by 16S pyrosequencing

    Directory of Open Access Journals (Sweden)

    Cuicui Xiao

    2016-07-01

    Full Text Available Dental caries has a polymicrobial etiology within the complex oral microbial ecosystem. However, the overall diversity and structure of supragingival plaque microbiota in adult dental health and caries are not well understood. Here, 160 supragingival plaque samples from patients with dental health and different severities of dental caries were collected for bacterial genomic DNA extraction, pyrosequencing by amplification of the 16S rDNA V1–V3 hypervariable regions, and bioinformatic analysis. High-quality sequences (2,261,700 clustered into 10,365 operational taxonomic units (OTUs; 97% identity, representing 453 independent species belonging to 122 genera, 66 families, 34 orders, 21 classes, and 12 phyla. All groups shared 7522 OTUs, indicating the presence of a core plaque microbiome. Smooth rarefaction curves were suggestive of plaque microbial diversity. α diversity analysis showed that healthy plaque microbial diversity exceeded that of dental caries, with the diversity decreasing gradually with the severity of caries. The dominant phyla of plaque microbiota included Bacteroidetes, Actinobacteria, Proteobacteria, Firmicutes, Fusobacteria, and TM7. The dominant genera included Capnocytophaga, Prevotella, Actinomyces, Corynebacterium, Neisseria, Streptococcus, Rothia, and Leptotrichia. β diversity analysis showed that the plaque microbial community structure was similar in all groups and that group members were relatively constant, only showing differences in abundance. Analysis of composition differences identified 10 health-related and 21 caries-related genera. Key genera (27 that potentially contributed to plaque microbiota distributions between groups were identified. Finally, co-occurrence network analysis and function prediction were performed. Treatment strategies directed toward modulating microbial interactions and their functional output should be further developed.

  10. Reliability and discriminatory power of methods for dental plaque quantification

    Directory of Open Access Journals (Sweden)

    Daniela Prócida Raggio

    2010-04-01

    Full Text Available OBJECTIVE: This in situ study evaluated the discriminatory power and reliability of methods of dental plaque quantification and the relationship between visual indices (VI and fluorescence camera (FC to detect plaque. MATERIAL AND METHODS: Six volunteers used palatal appliances with six bovine enamel blocks presenting different stages of plaque accumulation. The presence of plaque with and without disclosing was assessed using VI. Images were obtained with FC and digital camera in both conditions. The area covered by plaque was assessed. Examinations were done by two independent examiners. Data were analyzed by Kruskal-Wallis and Kappa tests to compare different conditions of samples and to assess the inter-examiner reproducibility. RESULTS: Some methods presented adequate reproducibility. The Turesky index and the assessment of area covered by disclosed plaque in the FC images presented the highest discriminatory powers. CONCLUSION: The Turesky index and images with FC with disclosing present good reliability and discriminatory power in quantifying dental plaque.

  11. 18FDG PET and ultrasound echolucency in carotid artery plaques

    DEFF Research Database (Denmark)

    Graebe, Martin; Pedersen, Sune F; Højgaard, Liselotte

    2010-01-01

    OBJECTIVES: The objective was to evaluate inflammation in echolucent carotid artery plaques. BACKGROUND: Ultrasound echolucency of carotid artery plaques has been proven to differentiate patients at high risk of stroke. On the other hand, positron emission tomography (PET) of plaques with the use...... for ultrasound and PET imaging. Plaque standardized gray scale medians (GSM) were measured in longitudinal ultrasound images to quantitate echolucency, and GSM values were compared with FDG PET uptake quantified by maximum standardized uptake values (SUV). Symptomatic plaques were compared with contralateral...... plaques ranged from high to low inflammatory activity, as depicted with PET. Quantitative FDG SUV differentiated asymptomatic from symptomatic plaques, whereas GSM values did not. There was a positive correlation between CD68 expression and FDG uptake (r = 0.50, p = 0.04). CONCLUSIONS: Our results...

  12. Plaque accumulations caused by interdental stripping.

    Science.gov (United States)

    Radlanski, R J; Jäger, A; Schwestka, R; Bertzbach, F

    1988-11-01

    Human enamel surfaces were stripped with orthodontic grinding and finishing materials, and evaluated with the scanning electron microscope (SEM). Even under in vitro conditions with the finest finishing strips, it was not possible to produce an enamel surface free of the furrows that result from the initial abrasion caused by the coarse strip. Enamel surfaces stripped gradually from coarse to superfine were left in the mouths of patients for 12 weeks and evaluated with the SEM. The edges of the furrows were found to be smoother but the furrows remained wide and deep enough to facilitate more plaque accumulations than those on untreated surfaces. The use of dental floss did not result in prevention of plaque accumulations along the bottom of the furrows.

  13. Oculocutaneous albinism complicated with an ulcerated plaque

    Directory of Open Access Journals (Sweden)

    Lokanatha Keshavalu

    2013-04-01

    Full Text Available A 32-year-old male with a history of albinism and farmer by occupation presented with an ulcerated plaque on the right wrist. The patient had light eyes, hair, and skin. Physical examination showed extensive photodamage. A skin biopsy specimen from the plaque revealed a well-differentiated squamous-cell carcinoma. Wide surgical excision was done. The most common types of oculocutaneous albinism (OCA, OCA 1 and OCA 2, are autosomal recessive disorders of pigmentation that commonly affect the skin, hair and eyes. Photodamage and skin cancers plague patients with albinism. Albinos face a myriad of social and medical issues. Importance of photoprotection, skin cancer surveillance and treatment has been stressed upon in this report.

  14. Noninvasive diagnosis of vulnerable coronary plaque

    Science.gov (United States)

    Pozo, Eduardo; Agudo-Quilez, Pilar; Rojas-González, Antonio; Alvarado, Teresa; Olivera, María José; Jiménez-Borreguero, Luis Jesús; Alfonso, Fernando

    2016-01-01

    Myocardial infarction and sudden cardiac death are frequently the first manifestation of coronary artery disease. For this reason, screening of asymptomatic coronary atherosclerosis has become an attractive field of research in cardiovascular medicine. Necropsy studies have described histopathological changes associated with the development of acute coronary events. In this regard, thin-cap fibroatheroma has been identified as the main vulnerable coronary plaque feature. Hence, many imaging techniques, such as coronary computed tomography, cardiac magnetic resonance or positron emission tomography, have tried to detect noninvasively these histomorphological characteristics with different approaches. In this article, we review the role of these diagnostic tools in the detection of vulnerable coronary plaque with particular interest in their advantages and limitations as well as the clinical implications of the derived findings. PMID:27721935

  15. Evidence-based control of plaque and gingivitis.

    Science.gov (United States)

    Santos, A

    2003-01-01

    Most adults brush and floss inadequately, and constant education and/or reinforcement is often required. Bacteria are usually left behind with mechanical oral health routines, and chemotherapeutic agents may have a key role as adjuncts to daily home-care. To date, two antiseptic mouthwashes have received the ADA Seal of Acceptance: Peridex (Zila Pharmaceuticals, Phoenix, AZ, USA; CHX, chlorhexidine) and Listerine (Pfizer Consumer Healthcare, Morris Plains, NJ, USA; essential oil (EO) mouthwash). CHX has a strong affinity for tooth and tissue surfaces, but can cause brown staining on the teeth and tongue. Patients must also wait until all traces of toothpaste are removed before rinsing with CHX. Long-term use of an EO mouthwash is microbiologically safe, with no changes observed in the bacterial composition of supragingival plaque, and no evidence of antimicrobial resistance. A number of trials have demonstrated the long-term plaque- and gingivitis-reducing properties of both CHX and EO mouthwashes. These studies clearly demonstrate that these agents have lasting efficacy, and can access hard-to-reach areas.

  16. Intradural extramedullary tuberculoma mimicking en plaque meningioma

    Directory of Open Access Journals (Sweden)

    Ozek Erdinc

    2009-01-01

    Full Text Available In this paper we report an 18 year old woman with an intradural extramedullary tuberculoma mimicking en plaque meningioma located in the thoracic region. The patient was operated via thoracic laminoplasty and tumor was totally resected. On the follow-up examination the magnetic resonance imaging demonstrated the total excision of the tumor. Here we describe a case of intradural extramedullary tuberculoma of the spinal cord as a complication of tuberculosis meningitis in a previously healthy young female.

  17. Polarization properties of amyloid-beta plaques in Alzheimer's disease (Conference Presentation)

    Science.gov (United States)

    Baumann, Bernhard; Wöhrer, Adelheid; Ricken, Gerda; Pircher, Michael; Kovacs, Gabor G.; Hitzenberger, Christoph K.

    2016-03-01

    In histopathological practice, birefringence is used for the identification of amyloidosis in numerous tissues. Amyloid birefringence is caused by the parallel arrangement of fibrous protein aggregates. Since neurodegenerative processes in Alzheimer's disease (AD) are also linked to the formation of amyloid-beta (Aβ) plaques, optical methods sensitive to birefringence may act as non-invasive tools for Aβ identification. At last year's Photonics West, we demonstrated polarization-sensitive optical coherence tomography (PS-OCT) imaging of ex vivo cerebral tissue of advanced stage AD patients. PS-OCT provides volumetric, structural imaging based on both backscatter contrast and tissue polarization properties. In this presentation, we report on polarization-sensitive neuroimaging along with numerical simulations of three-dimensional Aβ plaques. High speed PS-OCT imaging was performed using a spectral domain approach based on polarization maintaining fiber optics. The sample beam was interfaced to a confocal scanning microscope arrangement. Formalin-fixed tissue samples as well as thin histological sections were imaged. For comparison to the PS-OCT results, ray propagation through plaques was modeled using Jones analysis and various illumination geometries and plaque sizes. Characteristic polarization patterns were found. The results of this study may not only help to understand PS-OCT imaging of neuritic Aβ plaques but may also have implications for polarization-sensitive imaging of other fibrillary structures.

  18. Is the red fluorescence of dental plaque related to its cariogenicity?

    Science.gov (United States)

    Bittar, Daniela G.; Pontes, Laura Regina A.; Calvo, Ana Flávia B.; Novaes, Tatiane F.; Braga, Mariana M.; Freitas, Patrícia M.; Tabchoury, Cinthia P. M.; Mendes, Fausto M.

    2014-06-01

    It has been speculated that the red fluorescence emitted by dental plaque could be related to its cariogenicity. To test this hypothesis, we designed this crossover in situ study, with two experimental phases of 14 days each. Seventeen volunteers, wearing a palatal appliance with bovine enamel blocks, were instructed to drip a 20% sucrose solution (experimental group) or purified water (control group) onto the enamel blocks eight times daily. The specimens were removed after 4, 7, 10, and 14 days, and the red fluorescence of dental plaque formed on the enamel blocks was assessed using a quantitative light-induced fluorescence device. After the plaque removal, surface and cross-sectional microhardness tests were performed to assess the mineral loss. The comparisons were made by a multilevel linear regression analysis. We observed a significant increase in the red fluorescence of the dental plaque after longer periods of formation, but this trend was verified in both groups. The mineral loss assessed by the microhardness techniques, contrariwise, showed a significant increase only in the experimental group. In conclusion, the red fluorescence emitted by the dental plaque indicates a mature biofilm, but this fact is not necessarily associated with its cariogenicity.

  19. Automated classification of atherosclerotic plaque from magnetic resonance images using predictive models.

    Science.gov (United States)

    Anderson, Russell W; Stomberg, Christopher; Hahm, Charles W; Mani, Venkatesh; Samber, Daniel D; Itskovich, Vitalii V; Valera-Guallar, Laura; Fallon, John T; Nedanov, Pavel B; Huizenga, Joel; Fayad, Zahi A

    2007-01-01

    The information contained within multicontrast magnetic resonance images (MRI) promises to improve tissue classification accuracy, once appropriately analyzed. Predictive models capture relationships empirically, from known outcomes thereby combining pattern classification with experience. In this study, we examine the applicability of predictive modeling for atherosclerotic plaque component classification of multicontrast ex vivo MR images using stained, histopathological sections as ground truth. Ten multicontrast images from seven human coronary artery specimens were obtained on a 9.4 T imaging system using multicontrast-weighted fast spin-echo (T1-, proton density-, and T2-weighted) imaging with 39-mum isotropic voxel size. Following initial data transformations, predictive modeling focused on automating the identification of specimen's plaque, lipid, and media. The outputs of these three models were used to calculate statistics such as total plaque burden and the ratio of hard plaque (fibrous tissue) to lipid. Both logistic regression and an artificial neural network model (Relevant Input Processor Network-RIPNet) were used for predictive modeling. When compared against segmentation resulting from cluster analysis, the RIPNet models performed between 25 and 30% better in absolute terms. This translates to a 50% higher true positive rate over given levels of false positives. This work indicates that it is feasible to build an automated system of plaque detection using MRI and data mining.

  20. Arsenic mobilization and speciation during iron plaque decomposition in a paddy soil

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hai; Chen, Zheng; Sun, Guoxin [Chinese Academy of Sciences, Beijing (China). Research Center for Eco-environmental Sciences; Zhu, Yongguan [Chinese Academy of Sciences, Beijing (China). Research Center for Eco-environmental Sciences; Chinese Academy of Sciences, Xiamen (China). Key Lab. of Urban Environment and Health; Yin, Xixiang [Chinese Academy of Sciences, Xiamen (China). Key Lab. of Urban Environment and Health; Chinese Academy of Sciences, Beijing (China). Research Center for Eco-environmental Sciences

    2012-03-15

    Little information is available concerning the mobilization and speciation of arsenic (As) in paddy soils during iron plaque decomposition. It is important to investigate these processes since they affect As bioavailability and contaminate surface and ground water systems. A microcosm experiment was conducted to investigate the reductive dissolution of iron plaque and subsequent As mobilization under NaN{sub 3} sterilized (abiotic treatments) and non-sterilized (biotic treatments) paddy soil conditions. In the biotic treatment, As and iron (Fe) were quickly released into the soil solution, with more than 76.1% of total arsenic (T{sub As}) on the roots lost in 27 days. In the abiotic treatment, both iron plaque decomposition and As release were significantly slower, with only 39.4% of T{sub As} on the roots lost in 85 days. A part of arsenate reduction reaction occurred before and may also occur after release from roots in both abiotic and biotic treatments. Bacterial abundance, quantified by real-time PCR, varied significantly between treatments. Terminal restriction fragment length polymorphism combined with principal component analysis (PCA) revealed that microbial community structures were also different between treatments. The changes in microbial factors (bacterial abundance and microbial diversity and activities) significantly affected iron plaque decomposition, As mobilization, and speciation processes. Iron plaque reductive dissolution was likely the major factor leading to As release. Most As released was trapped in the solid phase during the incubation period. (orig.)

  1. Retroperitoneal liposarcoma associated with small plaque parapsoriasis

    Directory of Open Access Journals (Sweden)

    Polichetti Paolo

    2007-07-01

    Full Text Available Abstract Background Extremely rare cases of paraneoplastic syndromes or ectopic production of proteins associated with liposarcoma are reported in literature. Production of Granulocyte-Colony Stimulating Factor, alpha-fetoprotein, paraneoplastic pemphigus and leucocytosis, Acrokeratosis paraneoplastica (Bazex's syndrome are reported. The present report describes a case of retroperitoneal liposarcoma associated with small plaque parapsoriasis. Our search in the English literature of such a kind of association did not reveal any case reported. Case presentation A 74 year male patient was admitted to our hospital because of the presence of an abdominal mass in right iliac fossa. He also complained of a two-year history of psoriasiform eruptions. The CT scan showed a retroperitoneal pelvic mass. Therefore surgical resection of the tumor was performed. After surgery, the skin eruptions disappeared completely in seven days and so a diagnosis of parapsoriasis syndrome was done. Conclusion Parallel disappearing of skin eruptions after surgery, typical clinical picture and not specific histology of the cutaneous lesions suggest the diagnosis of small plaque parapsoriasis. Therefore we propose to add Small Plaque Parapsoriasis to the list of paraneoplastic syndromes associated to liposarcoma.

  2. Elevated plasma lipoprotein-associated phospholipase A2 activity is associated with plaque rupture in patients with coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    LIU Chuan-fen; QIN Li; REN Jing-yi; CHEN Hong; WANG Wei-min; LIU Jian; SONG Jun-xian; LI Li-jun

    2011-01-01

    Background Lipoprotein-associated phospholipase A2 (Lp-PLA2) has recently been shown to be positively related to coronary events in patients with coronary artery disease (CAD). However, direct evidence about the relationship between circulation Lp-PLA2 activity and vulnerable plaque in patients with CAD remains lacking.Methods Plasma Lp-PLA2 activity was determined in 146 consecutive patients with CAD who underwent clinically-indicated coronary angiography and preinterventional intravascuiar ultrasound (IVUS).Results Eighty-three patients were included in the final analysis after the initial screening. Sixty (72.3%) were acute coronary syndrome (ACS) patients and 23 (27.7%) were stable angina pectoris (SAP) patients. Plaque rupture occurred in 39 (47.0%) patients, and 34 (87.2%) were from ACS patients and 5 (12.8%) from SAP patients. There were no significant differences in clinical and angiographic characteristics between patients with plaque rupture and those without plaque rupture, except for smoking, high-sensitive C-reactive protein (hs-CRP) level and Lp-PLA2 activity (all P <0.05).IVUS measurement uncovered that patients with plaque rupture had more frequent positive remodeling (74.4% vs.43.2%, P=0.004), soft plaques (64.1% vs. 36.4%, P=0.012) and higher remodeling index (1.13±0.16 vs. 0.99±0.11,P=0.041) as compared with those without plaque rupture. Multivariate Logistic regression analysis showed that plasma Lp-PLA2 activity was independently associated with plaque rupture after adjusting for smoking, positive remodeling and soft plaque (Model 1: odds ratio (OR) 1.13, 95% confidence interval (CI): 1.06-1.20) or adjusting for smoking, hs-CRP level, positive remodeling and soft plaque (Model 2: OR 1.11, 95%CI: 1.04-1.1 9).Conclusions Plasma Lp-PLA2 activity is associated with plaque rupture in patients with CAD, independently of traditional CAD risk factors, hs-CRP level and IVUS parameters. Lp-PLA2 may be a risk marker for vulnerable plaques.

  3. Extracellular matrix proteomics identifies molecular signature of symptomatic carotid plaques

    Science.gov (United States)

    Langley, Sarah R.; Willeit, Karin; Didangelos, Athanasios; Matic, Ljubica Perisic; Skroblin, Philipp; Barallobre-Barreiro, Javier; Lengquist, Mariette; Rungger, Gregor; Kapustin, Alexander; Kedenko, Ludmilla; Molenaar, Chris; Lu, Ruifang; Barwari, Temo; Suna, Gonca; Iglseder, Bernhard; Paulweber, Bernhard; Willeit, Peter; Pasterkamp, Gerard; Davies, Alun H.; Monaco, Claudia; Hedin, Ulf; Shanahan, Catherine M.; Willeit, Johann; Kiechl, Stefan

    2017-01-01

    BACKGROUND. The identification of patients with high-risk atherosclerotic plaques prior to the manifestation of clinical events remains challenging. Recent findings question histology- and imaging-based definitions of the “vulnerable plaque,” necessitating an improved approach for predicting onset of symptoms. METHODS. We performed a proteomics comparison of the vascular extracellular matrix and associated molecules in human carotid endarterectomy specimens from 6 symptomatic versus 6 asymptomatic patients to identify a protein signature for high-risk atherosclerotic plaques. Proteomics data were integrated with gene expression profiling of 121 carotid endarterectomies and an analysis of protein secretion by lipid-loaded human vascular smooth muscle cells. Finally, epidemiological validation of candidate biomarkers was performed in two community-based studies. RESULTS. Proteomics and at least one of the other two approaches identified a molecular signature of plaques from symptomatic patients that comprised matrix metalloproteinase 9, chitinase 3-like-1, S100 calcium binding protein A8 (S100A8), S100A9, cathepsin B, fibronectin, and galectin-3-binding protein. Biomarker candidates measured in 685 subjects in the Bruneck study were associated with progression to advanced atherosclerosis and incidence of cardiovascular disease over a 10-year follow-up period. A 4-biomarker signature (matrix metalloproteinase 9, S100A8/S100A9, cathepsin D, and galectin-3-binding protein) improved risk prediction and was successfully replicated in an independent cohort, the SAPHIR study. CONCLUSION. The identified 4-biomarker signature may improve risk prediction and diagnostics for the management of cardiovascular disease. Further, our study highlights the strength of tissue-based proteomics for biomarker discovery. FUNDING. UK: British Heart Foundation (BHF); King’s BHF Center; and the National Institute for Health Research Biomedical Research Center based at Guy’s and St

  4. Effect of plaque accumulation and salivary factors on enamel demineralization and plaque composition in situ

    Directory of Open Access Journals (Sweden)

    Tenuta Livia Maria Andaló

    2003-01-01

    Full Text Available This study evaluated the effect of some plaque and salivary factors on caries progression in situ. The salivary secretion rate, buffering capacity and mutans streptococci counts from 13 volunteers were determined. For three distinct periods of time, 4, 7 and 10 days, each of them wore a palatal appliance containing 4 bovine enamel blocks. They used a non-fluoridated dentifrice during the experiment and a 20% sucrose solution was dripped onto the blocks 10 times a day. Mutans streptococci (MS, calcium (Ca, and insoluble polysaccharide (IP were quantified in the dental plaque formed on the enamel blocks, after each period. Enamel demineralization was assessed by surface microhardness, and the percentage of surface microhardness change (%SMC in relation to the baseline values was calculated. Enamel demineralization occurred after each period of plaque accumulation (p < 0.05, and the %SMC increased with time (from 13.8 to 48.3%. The concentrations of Ca and IP in plaque were not statistically different among the experimental times, but significant correlations were found between these concentrations and %SMC. Neither the salivary factors assessed initially nor mutans streptococci in plaque presented statistically significant correlations to %SMC. The results suggest that enamel demineralization is time-dependent and is more related to the composition of the biofilm formed than to the salivary factors studied.

  5. [A systematic review of anti-interleukin-17 antibody in the treatment of plaque psoriasis].

    Science.gov (United States)

    Fan, Xiao-Dong; Xia, Xiang; Zhang, Chun-Yan; Kong, Wen-Qiang; Zhou, Chun-Yang; DU, Biao

    2017-09-20

    To evaluate the efficacy and safety of anti-interleukin-17 antibody in the treatment of plaque psoriasis. Randomized controlled trials (RCT) of anti-interleukin-17 antibody (Secukinumab, Brodalumab, and Ixekizumab) in the treatment of plaque psoriasis published between January, 2000 and March, 2017 were searched from PubMed, Cochrane Library, EBSCO, EMbase, CBM, CNKI, VIPdetabase, and Wangfang database. The quality of the retrieved trials was evaluated and the results of studies were analyzed using RevMan 5.0 software. Thirteen RCTs were included involving a total of 11 203 patients. Meta-analysis showed a significant differences between anti-interleukin-17 antibody and placebo (or positive drug) in terms of PASI75 and sPGA (P0.05). Anti-interleukin-17 antibody is safe and effective for treatment of plaque psoriasis.

  6. [Microbiological composition of dental plaque using Sprague Dawley rats as an experimental model].

    Science.gov (United States)

    Sánchez, F R; Perrone, M; Acevedo, A M

    1990-01-01

    In this study, the microbiological composition of the dental plaque in 12 male Sprague-Dawley rats was determined. Analysis using the light microscope showed the presence of nine colonies which suggested the presence of cocci, (6) diplococci (1) and rods. (2) Five of the bacteria were Gram positive and three were Gram negative. The morphological characteristic suggested the presence of Actinomyces in the case of Gram positive rods; Fusobacterium in the case of Gram negative rods; Neisseria and Veillonella in the of Gram negative cocci and Streptococci for the rest of the colonies. The biochemical characterization of the bacteria suggested the absence of Streptococcus mutans in the dental plaque of this animals.

  7. Intravascular probe for detection of vulnerable plaque

    Science.gov (United States)

    Patt, Bradley E.; Iwanczyk, Jan S.; MacDonald, Lawrence R.; Yamaguchi, Yuko; Tull, Carolyn R.; Janecek, Martin; Hoffman, Edward J.; Strauss, H. William; Tsugita, Ross; Ghazarossian, Vartan

    2001-12-01

    Coronary angiography is unable to define the status of the atheroma, and only measures the luminal dimensions of the blood vessel, without providing information about plaque content. Up to 70% of heart attacks are caused by minimally obstructive vulnerable plaques, which are too small to be detected adequately by angiography. We have developed an intravascular imaging detector to identify vulnerable coronary artery plaques. The detector works by sensing beta or conversion electron radiotracer emissions from plaque-binding radiotracers. The device overcomes the technical constraints of size, sensitivity and conformance to the intravascular environment. The detector at the distal end of the catheter uses six 7mm long by 0.5mm diameter scintillation fibers coupled to 1.5m long plastic fibers. The fibers are offset from each other longitudinally by 6mm and arranged spirally around a guide wire in the catheter. At the proximal end of the catheter the optical fibers are coupled to an interface box with a snap on connector. The interface box contains a position sensitive photomultiplier tube (PSPMT) to decode the individual fibers. The whole detector assembly fits into an 8-French (2.7 mm in diameter) catheter. The PSPMT image is further decoded with software to give a linear image, the total instantaneous count rate and an audio output whose tone corresponds to the count rate. The device was tested with F-18 and Tl-204 sources. Spectrometric response, spatial resolution, sensitivity and beta to background ratio were measured. System resolution is 6 mm and the sensitivity is >500 cps / micrometers Ci when the source is 1 mm from the detector. The beta to background ratio was 11.2 for F-18 measured on a single fiber. The current device will lead to a system allowing imaging of labeled vulnerable plaque in coronary arteries. This type of signature is expected to enable targeted and cost effective therapies to prevent acute coronary artery diseases such as: unstable angina

  8. 单纯机械性菌斑控制对学龄前儿童变形链球菌的短期影响%Short term effect of mechanical plaque control on salivary S.mutans in preschool children

    Institute of Scientific and Technical Information of China (English)

    刘敏; 葛立宏; 郑树国; 袁超; 张波; 袁峻伟; 关雪琳; 苏颖; 徐韬

    2012-01-01

    Objective To verify the effect of mechanical tooth cleaning by toothbrush and dental floss on Streptococci mutans of preschool children. Methods Blinded randomized controlled clinical trial. 54 3 -year -old preschool children with detectable S. mutans were recruited. Dental college students cleaned the teeth of test group participants with toothbrush and dental floss under the indication of plaque disclosing agent once a day. Dentocult SM Strip mutans (D-SM) were used to test the S. mutans in saliva. Results The D-SM test scores had declined from 1.82 to 0.95 for the test group after 10 times of tooth cleaning (P0.05 compared with baseline). The D-SM level of control group had not fluctuated statistically. Conclusion Meticulous and continuous plaque control with tooth brush and dental floss can decrease the S. mutans level of preschool children, however, the effect ceased as the intervention ceased.%目的 评价用牙刷和牙线进行机械性菌斑控制对学龄前儿童变形链球菌的影响.方法 检查者单盲的随机对照临床研究.将54名唾液中检出变形链球菌的3岁学龄前儿童纳入该研究,随机分为实验组和对照组.菌斑染色后,口腔医学生给实验组儿童用牙刷和牙线彻底清洁牙面菌斑,不用牙膏,每天一次,共10次.用Dentocult SMStrip mutans (D-SM)监测唾液中变形链球菌的水平.结果 10次机械性菌斑控制结束后,实验组的D-SM值由基线的1.82下降到0.95(P<0.001),干预结束后2周D-SM值上升到1.62.对照组D-SM值的波动无统计学意义.结论 连续、彻底的单纯机械性菌斑控制能降低学龄前儿童变形链球菌水平,干预结束后该作用消失.

  9. Effects of decline in renal function with age on the outcome of asymptomatic carotid plaque in healthy adults:a 5-year follow-up study

    Institute of Scientific and Technical Information of China (English)

    JIANG Shi-min; SUN Xue-feng; GU Hong-xia; CHEN Yun-shuang; XI Chun-sheng; QIAO Xi; CHEN Xiang-mei

    2012-01-01

    Background It has been long suggested that abnormal clinical factors in the body,such as dyslipidemia and diabetes.can affect the presence of atherosclerosis.However,few studies on the effect of factors within the normal range,such as the loss of renal function with age,on the prevalence of atherosclerosis are few know in healthy individuals.The aim of this study was to investigate risk factors affecting the presence of asymptomatic carotid plaques in a middle-aged and elderly healthy population.Methods In this regard,we prospectively evaluated 245 healthy individuals (98 males and 147 females) at baseline and after 5 years.Changes in the presence of carotid plaque between 2003 and 2008 were categorized into four groups,i.e.subjects without plaque at entry (n=165):Group 1 (without plaque on two occasions,n=129) and Group 2 (with nascent plaque at follow-up,n=36); subjects with plaque at entry (n=80); Group 3 (with plaque regression at follow-up,n=29) and Group 4 (with plaque on two occasions,n=51).Results Univariate analysis showed that the positive rate of carotid plaques in males was higher than that in females at the baseline,and that a significantly inverse correlation existed between the prevalence rate of plaque and aging.Logistic regression analysis of cross-sectional research showed that independent risk factors for the prevalence of atherosclerosis were male gender,lower estimated glomerular filtration rate (eGFR) and higher low-density lipoprotein cholesterol (LDL-C) at the baseline,and older age and lower eGFR were involved in the presence of carotid plaques at follow-up point.However,logistic regression analysis of the longitudinal data showed that older age,decreased eGFR and increased systolic blood pressure (SBP) independently predicted the presence of carotid plaques after 5 years in subjects without plaque at entry.In addition,in subjects with plaque at entry,age,changes in eGFR and the baseline levels of serum albumin (ALB) and serum total

  10. Thrombosis and morphology of plaque rupture using optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    GUO Jun; CHEN Yun-dai; TIAN Feng; LIU Hong-bin; CHEN Lian; SUN Zhi-jun; REN Yi-hong

    2013-01-01

    Background Thrombosis following plaque rupture is the main cause of acute coronary syndrome,but not all plaque ruptures lead to thrombosis.There are limited in vivo data on the relationship between the morphology of ruptured plaque and thrombosis.Methods We used optical coherence tomography (OCT) to investigate the morphology of plaque rupture and its relation to coronary artery thrombosis in patients with coronary heart disease.Forty-two patients with coronary artery plaque rupture detected by OCT were divided into two groups (with or without thrombus) and the morphological characteristics of ruptured plaque,including fibrous cap thickness and broken cap site,were recorded.Results The fibrous cap of ruptured plaque with thrombus was significantly thinner compared to caps without thrombus ((57.00±17.00) μm vs.(96.00±48.00) μm; P=0.0076).Conclusions Plaque rupture associated with thrombosis occurs primarily in plaque covered by a thin fibrous cap.Thick fibrous caps are associated with greater stability of ruptured plaque.

  11. From quantitative protein complex analysis to disease mechanism.

    Science.gov (United States)

    Texier, Y; Kinkl, N; Boldt, K; Ueffing, M

    2012-12-15

    Interest in the field of cilia biology and cilia-associated diseases - ciliopathies - has strongly increased over the last few years. Proteomic technologies, especially protein complex analysis by affinity purification-based methods, have been used to decipher various basic but also disease-associated mechanisms. This review focusses on some selected recent studies using affinity purification-based protein complex analysis, thereby exemplifying the great possibilities this technology offers.

  12. Mobility analysis of parallel mechanisms based on screw theory and mechanism topology

    Directory of Open Access Journals (Sweden)

    Liping Wang

    2015-11-01

    Full Text Available A practical method for mobility analysis of mechanisms is presented in this article, which is based on the screw theory and the topology structure of mechanisms. The proposed method can be summarized as one core principle and two key techniques. The core principle is that the series connection of kinematic pairs is equivalent to the superposition of corresponding degrees of freedom, and the parallel connection of kinematic pairs is equivalent to the superposition of corresponding constraints. The first key technique for analyzing the mobility of mechanisms is to correctly identify the series and parallel connection relationship between all kinematic pairs, that is, the mechanism topology structure. Another key technique is transforming the screws and reciprocal screws from local coordinate systems to the global coordinate system. First, the above-mentioned method is presented in theory. Then, several examples are analyzed using it, which validate its effectiveness and universality.

  13. UPDATE ON MECHANICAL ANALYSIS OF MONOLITHIC FUEL PLATES

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Burkes; F. J. Rice; J.-F. Jue; N. P. Hallinan

    2008-03-01

    Results on the relative bond strength of the fuel-clad interface in monolithic fuel plates have been presented at previous RRFM conferences. An understanding of mechanical properties of the fuel, cladding, and fuel / cladding interface has been identified as an important area of investigation and quantification for qualification of monolithic fuel forms. Significant progress has been made in the area of mechanical analysis of the monolithic fuel plates, including mechanical property determination of fuel foils, cladding processed by both hot isostatic pressing and friction bonding, and the fuel-clad composite. In addition, mechanical analysis of fabrication induced residual stress has been initiated, along with a study to address how such stress can be relieved prior to irradiation. Results of destructive examinations and mechanical tests are presented along with analysis and supporting conclusions. A brief discussion of alternative non-destructive evaluation techniques to quantify not only bond quality, but also bond integrity and strength, will also be provided. These are all necessary steps to link out-of-pile observations as a function of fabrication with in-pile behaviours.

  14. Smallpox virus plaque phenotypes: genetic, geographical and case fatality relationships.

    Science.gov (United States)

    Olson, Victoria A; Karem, Kevin L; Smith, Scott K; Hughes, Christine M; Damon, Inger K

    2009-04-01

    Smallpox (infection with Orthopoxvirus variola) remains a feared illness more than 25 years after its eradication. Historically, case-fatality rates (CFRs) varied between outbreaks (<1 to approximately 40 %), the reasons for which are incompletely understood. The extracellular enveloped virus (EEV) form of orthopoxvirus progeny is hypothesized to disseminate infection. Investigations with the closely related Orthopoxvirus vaccinia have associated increased comet formation (EEV production) with increased mouse mortality (pathogenicity). Other vaccinia virus genetic manipulations which affect EEV production inconsistently support this association. However, antisera against vaccinia virus envelope protect mice from lethal challenge, further supporting a critical role for EEV in pathogenicity. Here, we show that the increased comet formation phenotypes of a diverse collection of variola viruses associate with strain phylogeny and geographical origin, but not with increased outbreak-related CFRs; within clades, there may be an association of plaque size with CFR. The mechanisms for variola virus pathogenicity probably involves multiple host and pathogen factors.

  15. Thermo-Mechanical Modeling and Analysis for Turbopump Assemblies

    Science.gov (United States)

    Platt, Mike; Marsh, Matt

    2003-01-01

    Life, reliability, and cost are strongly impacted by steady and transient thermo-mechanical effect. Design cycle can suffer big setbacks when working a transient stress/deflection issue. Balance between objectives and constrains is always difficult. Requires assembly-level analysis early in the design cycle.

  16. An Analysis of the Waste Water Treatment Maintenance Mechanic Occupation.

    Science.gov (United States)

    Clark, Anthony B.; And Others

    The general purpose of the occupational analysis is to provide workable, basic information dealing with the many and varied duties performed in the waste water treatment mechanics occupation. The document opens with a brief introduction followed by a job description. The bulk of the document is presented in table form. Twelve duties are broken…

  17. Thermal hydraulic and mechanical analysis of CH HCSB TBM

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-yu; FENG Kai-ming; ZHANG Guo-shu; YUAN Tao

    2006-01-01

    Based on the structure design and results of neutronics analysis of the CH HCSB TBM (Chinese helium cooled solid breeder test blanket module), thermal hydraulic and mechanical analyses have been carried out. Results show that the design of the CH HCSB TBM is reasonable and acceptable.

  18. Do radial oxygen loss and external aeration affect iron plaque formation and arsenic accumulation and speciation in rice?

    Science.gov (United States)

    Wu, Chuan; Ye, Zhihong; Li, Hui; Wu, Shengchun; Deng, Dan; Zhu, Yongguan; Wong, Minghung

    2012-05-01

    Hydroponic experiments were conducted to investigate the effect of radial oxygen loss (ROL) and external aeration on iron (Fe) plaque formation, and arsenic (As) accumulation and speciation in rice (Oryza sativa L.). The data showed that there were significant correlations between ROL and Fe concentrations in Fe plaque produced on different genotypes of rice. There were also significant differences in the amounts of Fe plaque formed between different genotypes in different positions of roots and under different aeration conditions (aerated, normal, and stagnant treatments). In aerated treatments, rice tended to have a higher Fe plaque formation than in a stagnant solution, with the greatest formation at the root tip decreasing with increasing distances away, in accordance with a trend of spatial ROL. Genotypes with higher rates of ROL induced higher degrees of Fe plaque formation. Plaques sequestered As on rice roots, with arsenate almost double that with arsenite, leading to decreased As accumulation in both roots and shoots. The major As species detected in roots and shoots was arsenite, ranging from 34 to 78% of the total As in the different treatments and genotypes. These results contribute to our understanding of genotypic differences in As uptake by rice and the mechanisms causing rice genotypes with higher ROL to show lower overall As accumulation.

  19. Preliminary antiplaque efficacy of aloe vera mouthwash on 4 day plaque re-growth model: randomized control trial.

    Science.gov (United States)

    Gupta, Rajendra Kumar; Gupta, Devanand; Bhaskar, Dara John; Yadav, Ankit; Obaid, Khursheed; Mishra, Sumit

    2014-04-01

    Due to increasing resistance to antibiotics and rising incidence of oral diseases, there is a need for alternative treatment modalities to combat oral diseases. The aim of the present study was to access the effect of Aloe vera mouthwash on the dental plaque in the experimental period of 4 days and to compare it with the bench mark control chlorhexidine and placebo (saline water). A total of 300 systemically healthy subjects were randomly allocated into 3 groups: Aloe vera mouthwash group (n=100), control group (=100)-chlorhexidene group and saline water-Placebo (n=100). To begin with, Gingival index (GI) and plaque index (PI) were recorded. Then, baseline plaque scores were brought to zero by professionally cleaning the teeth with scaling and polishing. After randomization of the participants into three groups they were refrained from regular mechanical oral hygiene measures. Subjects were asked to swish with respective mouthwash (Aloe vera mouthwash, 0.2%chlorhexidine gluconate mouthwash, or normal saline) as per therapeutic dose for 4 days. The results showed that Aloe vera mouthrinse is equally effective in reducing plaque as Chlorhexidine compared to placebo over a period of 4 days. There was a significant reduction on plaque in Aloe vera and chlorhexidine groups and no statistically significant difference was observed among them (p>0.05). Aloe vera mouthwash showed no side effects. The results of the present study indicated that Aloe vera may prove an effective mouthwash due to its ability in reducing dental plaque.

  20. Dynamic Model Visualizing the Process of Viral Plaque Formation

    Directory of Open Access Journals (Sweden)

    Boriana Marintcheva

    2012-09-01

    Full Text Available In Microbiology and Virology courses, viral plaques are often presented to students as the way one can visualize viruses/bacteriophages. While students generally grasp the idea that counting plaques is essentially the same as counting viruses in their sample (assuming that one virus entering the cell is sufficient for productive infection, the process of plaque formation itself remains largely obscure. Many students fail to appreciate that viral plaques are actually a “laboratory-made” phenomenon allowing us to observe and study the growth of lytic viruses. The latter often presents a challenge for the interpretation of experimental data related to viral growth and drug discovery using plaque reduction assay. The hands-on model described here creates an opportunity for students to experience the process of viral plaque formation while engaging multiple senses and creating a lasting impression.  

  1. Clinical evaluation of the cross-action and between teeth toothbrushes effects on the bacterial plaque and gingival status

    Directory of Open Access Journals (Sweden)

    Sayar Ferena

    2015-05-01

    Full Text Available Background and Aims: The routine mechanical plaque control is done by toothbrush. With regard to different designs of tooth head brushes in order to better plaque removal, the aim of this study was to evaluate the effect of between teeth and cross-action tooth brush on the plaque and gingival status among dental students of dental branch-Islamic Azad University during 2012-13 academic years.   Materials and Methods: This single-blind, cross over, clinical trial was conducted on 30 subjects with mean age (23±0.9 in two groups of 15 persons . They had at least 20 teeth and had gingivitis with no history of antibiotic use in the last 3 months. Those who were undergoing orthodontic treatment, using drugs affecting the gums and having crown and bridge were excluded from the study. The first group used the cross action toothbrush and the second group used between teeth toothbrush and the subjects were asked to brush their teeth for two minutes twice a day in modified bass method and not to floss during the execution of this study. After 14 days plaque index (Turesky, Approximal plaque index and gingival bleeding index were recorded on all teeth except third molars. After a week wash out period, second stage of the study was conducted the same as the first stage with the other kind of brush for each group. Data were analyzed using Generalized Linear Model (GLM test.   Results: There was no statistical significant difference between two toothbrushes based on plaque index, gingival bleeding index and approximal plaque index, respectively (P = 0.29, P = 0.47, P = 0.33. In all measured indices, the treatment sequence showed no significant difference (P = 0.23.   Conclusion: There was no statistical difference between cross-action and between teeth toothbrush in reducing plaque and gingival bleeding.

  2. Molecular Phenotyping Small (Asian) versus Large (Western) Plaque Psoriasis Shows Common Activation of IL-17 Pathway Genes but Different Regulatory Gene Sets.

    Science.gov (United States)

    Kim, Jaehwan; Oh, Chil-Hwan; Jeon, Jiehyun; Baek, Yoosang; Ahn, Jaewoo; Kim, Dong Joo; Lee, Hyun-Soo; Correa da Rosa, Joel; Suárez-Fariñas, Mayte; Lowes, Michelle A; Krueger, James G

    2016-01-01

    Psoriasis is present in all racial groups, but in varying frequencies and severity. Considering that small plaque psoriasis is specific to the Asian population and severe psoriasis is more predominant in the Western population, we defined Asian small and intermediate plaque psoriasis as psoriasis subtypes and compared their molecular signatures with the classic subtype of Western large plaque psoriasis. Two different characteristics of psoriatic spreading-vertical growth and radial expansion-were contrasted between subtypes, and genomic data were correlated to histologic and clinical measurements. Compared with Western large plaque psoriasis, Asian small plaque psoriasis revealed limited psoriasis spreading, but IL-17A and IL-17-regulated proinflammatory cytokines were highly expressed. Paradoxically, IL-17A and IL-17-regulated proinflammatory cytokines were lower in Western large plaque psoriasis, whereas T cells and dendritic cells in total psoriatic skin area were exponentially increased. Negative immune regulators, such as CD69 and FAS, were decreased in both Western large plaque psoriasis and psoriasis with accompanying arthritis or obesity, and their expression was correlated with psoriasis severity index. Based on the disease subtype comparisons, we propose that dysregulation of T-cell expansion enabled by downregulation of immune negative regulators is the main mechanism for development of large plaque psoriasis subtypes.

  3. SU-E-T-635: Process Mapping of Eye Plaque Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, J; Kim, Y [University of Arizona, Tucson, AZ (United States)

    2015-06-15

    Purpose: To apply a risk-based assessment and analysis technique (AAPM TG 100) to eye plaque brachytherapy treatment of ocular melanoma. Methods: The role and responsibility of personnel involved in the eye plaque brachytherapy is defined for retinal specialist, radiation oncologist, nurse and medical physicist. The entire procedure was examined carefully. First, major processes were identified and then details for each major process were followed. Results: Seventy-one total potential modes were identified. Eight major processes (corresponding detailed number of modes) are patient consultation (2 modes), pretreatment tumor localization (11), treatment planning (13), seed ordering and calibration (10), eye plaque assembly (10), implantation (11), removal (11), and deconstruction (3), respectively. Half of the total modes (36 modes) are related to physicist while physicist is not involved in processes such as during the actual procedure of suturing and removing the plaque. Conclusion: Not only can failure modes arise from physicist-related procedures such as treatment planning and source activity calibration, but it can also exist in more clinical procedures by other medical staff. The improvement of the accurate communication for non-physicist-related clinical procedures could potentially be an approach to prevent human errors. More rigorous physics double check would reduce the error for physicist-related procedures. Eventually, based on this detailed process map, failure mode and effect analysis (FMEA) will identify top tiers of modes by ranking all possible modes with risk priority number (RPN). For those high risk modes, fault tree analysis (FTA) will provide possible preventive action plans.

  4. Applications of Digital Image Analysis in Experimental Mechanics

    DEFF Research Database (Denmark)

    Lyngbye, J. : Ph.D.

    The present thesis "Application of Digital Image Analysis in Experimental Mechanics" has been prepared as a part of Janus Lyngbyes Ph.D. study during the period December 1988 to June 1992 at the Department of Building technology and Structural Engineering, University of Aalborg, Denmark....... In this thesis attention will be focused on optimal use and analysis of the information of digital images. This is realized during investigation and application of parametric methods in digital image analysis. The parametric methods will be implemented in applications representative for the area of experimental...

  5. Mechanism and kinetics analysis of AlN combustion synthesis

    Institute of Scientific and Technical Information of China (English)

    郑永挺; 张宇民; 赫晓东; 刘长青

    2004-01-01

    Mechanism of AlN combustion synthesis was studied by DSC analysis and "quenching" experiment of combustion wave. In preheating region, Al powder melted at 660 ℃ and became spherical because of surface tension. In reaction region, Al volatilized rapidly at 1 000 ℃ and Al vapor reacted with N2 to form AlN, which nucleated and grew on the surface of AlN formed precedently as a diluent. Based on the experiment analysis,kinetics equations and modeling were established. Analysis showed the dramatic effect of temperature, aluminum particle size and nitrogen pressure on the reaction speed.

  6. Analysis of mechanical systems with transversal vibrations in transportation

    Directory of Open Access Journals (Sweden)

    A. Buchacz

    2008-12-01

    Full Text Available Purpose: of this article are modelling and dynamic analysis of mechanical systems during the rotationalmovement. Nowadays technical problems are tied with high speeds of mechanisms, high precision of work,using lower density materials, and many other high demands for elements of work. Objective of this paper wasthe analysis with giving into consideration the interaction between working motion and local vibrations. Themodel is loaded by transverse forces and transformed to the global reference frame.Design/methodology/approach: derived equations of motion were made by the Lagrange equations methodwith generalized coordinates and generalized velocities assumed as orthogonal projections of individualcoordinates and velocities of each beam to axes of the global reference frame.Findings: systems of equations of motion of transversally vibrating systems in two-dimensional motion willbe put to use to derivation of the dynamical flexibility of these systems and complex systems. Those equationsare the beginning of the analysis of complex systems. They can also be used to derivation of the substitutedynamical flexibility of n-linked systems.Research limitations/implications: mechanical systems vibrating transversally in terms of two-dimensionalmotion were considered in the thesis. The consecutive problem of dynamical analysis is modelling of systemsin spatial motion and also the analysis of systems loaded by longitudinal forces.Practical implications: mathematical effects of this article can be put to use into many mechanisms andmachines running in rotational transportation. For example applications are: high speed turbines, wind powerplants, rotors, manipulators and in aerodynamics issues, etc. Of course results should be adopted and modifiedto appropriate system.Originality/value: High demands for parameters of work of mechanisms and machines are the postulation fornew research and new ways of modelling and analyzing those type systems. The example way

  7. [Correlation between serum inflammatory cytokine levels and fibrous cap thickness of fibrofatty plaque in coronary culprit lesions].

    Science.gov (United States)

    Zhong, Y; Ye, F; You, W; Wu, Z M

    2017-07-24

    Objective: To identify the correlation between serum inflammatory cytokine levels including high sensitive C reactive protein (hs-CRP) and lipoprotein associated phospholipase (Lp-PLA2) and the fibrous cap thickness of fibrofatty plaque in coronary culprit lesions. Methods: Clinical data of 117 patients with selective coronary artery angiography diagnosed coronary artery disease admitted to our hospital from January 2015 to January 2016 were retrospective analyzed. According to type of coronary disease, patients were divided into 3 subgroups: SAP group (containing 47 stable angina patients), UAP group (containing 52 unstable angina patients), and NSTEMI group(containing 18 acute non ST segment elevation myocardial infarction patients). Serum hs-CRP and Lp-PLA2 levels were measured before subsequent procedures. The characteristics of the culprit lesions were detected by optical coherence tomogarpgy(OCT) before interventional treatment, and the correlation between hs-CRP and Lp-PLA2 and the fibrous cap thickness of fibrofatty plaque in coronary culprit lesions were analyzed. Results: (1) The serum levels of hs-CRP (2.13(1.04, 4.75)μg/L vs. 1.02(0.60, 1.29)μg/L and 1.30(1.03, 1.96)μg/L, all Pcap thickness of fibrofatty plaque in coronary culprit lesions were smaller in NSTEMI group and UAP group than in SAP group(50(50, 60)μm and 60(50, 90)μm vs. 130(80, 190)μm, all P0.05). Proportion of thin-cap fibroatheroma plaque(82.35%(14/18) vs. 19.15%(9/47) and 63.46%(33/52), all P0.05). (3) Pearson correlation analysis showed that serum levels of hs-CRP(r=-0.233, Pcap thickness of fibrofatty plaques. Spearman correlation analysis showed that serum levels of hs-CRP were positively correlated with plaque rupture(r=0.409, Pcap fibroatheroma plaque(OR=1.017, Pcap fibroatheroma plaque, plaque rupture and thrombosis was significantly higher in the NSTEMI patients, while the prevalence of calcification in plaque is more often in SAP patients. Increased serum levels of Lp-PLA2

  8. Plaques Formed by Mutagenized Viral Populations Have Elevated Coinfection Frequencies

    Science.gov (United States)

    Aguilera, Elizabeth R.; Erickson, Andrea K.; Jesudhasan, Palmy R.; Robinson, Christopher M.

    2017-01-01

    ABSTRACT The plaque assay is a common technique used to measure virus concentrations and is based upon the principle that each plaque represents a single infectious unit. As such, the number of plaques is expected to correlate linearly with the virus dilution plated, and each plaque should be formed by a single founder virus. Here, we examined whether more than one virus can contribute to plaque formation. By using genetic and phenotypic assays with genetically marked polioviruses, we found that multiple parental viruses are present in 5 to 7% of plaques, even at an extremely low multiplicity of infection. We demonstrated through visual and biophysical assays that, like many viral stocks, our viral stocks contain both single particles and aggregates. These data suggest that aggregated virions are capable of inducing coinfection and chimeric plaque formation. In fact, inducing virion aggregation via exposure to low pH increased coinfection in a flow cytometry-based assay. We hypothesized that plaques generated by viruses with high mutation loads may have higher coinfection frequencies due to processes restoring fitness, such as complementation and recombination. Indeed, we found that coinfection frequency correlated with mutation load, with 17% chimeric plaque formation for heavily mutagenized viruses. Importantly, the frequency of chimeric plaques may be underestimated by up to threefold, since coinfection with the same parental virus cannot be scored in our assay. This work indicates that more than one virus can contribute to plaque formation and that coinfection may assist plaque formation in situations where the amount of genome damage is high. PMID:28292984

  9. Aging mechanisms of perfluorocarbon emulsions using image analysis.

    Science.gov (United States)

    Freire, Mara G; Dias, Ana M A; Coelho, Maria A Z; Coutinho, João A P; Marrucho, Isabel M

    2005-06-01

    The aging mechanisms of perfluorocarbon emulsions were investigated using image analysis. Oil-in-water emulsions of two perfluorocarbons, n-perfluorohexane and perfluorodecalin, were prepared with three emulsifiers, Lecithin, Span 20, and Pluronic F-68. The effect of the temperature and the replacement of water by an aqueous phase consisting of a microbial culture medium were also studied. The emulsions were prepared by sonication and their stability was followed through analysis of the evolution of mean droplet size. The results indicate that the stability of perfluorocarbon in water emulsions depends on all the parameters investigated and that two aging mechanisms, coalescence and molecular diffusion, may take place. Analysis of the evolution of the mean droplet size during long time periods indicate that coalescence is more common than previously reported for these systems and seems to be favored by a temperature increase.

  10. Tennis Forehand Stroke Action of Biological Mechanics Analysis

    Directory of Open Access Journals (Sweden)

    Feng Li

    2013-05-01

    Full Text Available Forehand technique is the basic tennis technology, the highest utilization rate technology, but also the most lethal technology and one of the magic weapons of a tennis match. Grasp the qualitative and quantitative methods combined, the combination of video, movie, analytical and computer technology, combining the principles of the movement mechanics and mathematical statistics. Based on the biological mechanics principle and according to the latest research results of the element analysis and logic analysis, analysis of forehand stroke technical movement, which make us more subtle and correct understand forehand technique and eventually be able to provide a scientific theoretical guidance and practical reference for tennis teaching and training and make a small contribution to perfect tennis skills and innovation.

  11. Association of Streptococcus with Plaque Type of Psoriasis

    Directory of Open Access Journals (Sweden)

    Mohammad Akram Hossain

    2015-05-01

    Full Text Available Background: Guttate psoriasis has a well-known association with streptococcal throat infections, but the effects of these infections in patients with chronic plaque type of psoriasis remains to be evaluated. In Bangladesh several studies were done on psoriasis but no data about association between streptococcal throat infection and plaque type psoriasis are available so far. Considering the co-morbidities of psoriasis patients, it might be justifiable to find out the events that provoke the initiation or exacerbation of psoriatic disease process. Objective: To observe the association of streptococcus with plaque type of psoriasis. Materials and Methods: This observational study was conducted in the department of Dermatology and Venereology, Bangabandhu Sheikh Mujib Medical University, Dhaka. Forty seven patients clinically and histopathologically diagnosed as having plaque psoriasis were selected as cases and patients with skin diseases other than psoriasis were selected as controls. Results: In this study majority of subjects (55% were diagnosed as chronic plaque psoriasis. Among the subjects with guttate flare of chronic plaque psoriasis 64.2% gave a positive history of sore throat. ASO titer was raised (>200 IU/mL in 28 (59.5% patients of chronic plaque psoriasis and 7 (17.9% patients of non-psoriatic respondents. The difference between two groups was significant (p0.05. Conclusion: This study shows that streptococcal throat infections are associated with plaque psoriasis and early treatment of throat infections may be beneficial for plaque type of psoriasis patients.

  12. Microbial characterization of an experimental cariogenic plaque in man.

    Science.gov (United States)

    Ostrom, C A; Koulourides, T; Hickman, F; McGhee, J R

    1977-06-01

    Experimentally induced plaque seemed to originate by direct contact inoculation from the vestibular mucosa and saliva. During the next seven days, this plaque developed its own characteristics. Populations of Streptococcus mutans usually less than 2% of total streptococci population in plaques that were less than three days old, increased between days 3 and 7. Proportions of S sanguis, high in early samples, decreased after day 3. Populations of S salivarius, which usually outnumbered other streptococci, fluctuated widely through day 3, and then increased in proportion in subjects who were more productive of experimental caries, but decreased in subjects who were less productive. Proportions of plaque flora comprising lactobacilli paralleled those of S salivarius.

  13. Scaling analysis for the investigation of slip mechanisms in nanofluids

    Directory of Open Access Journals (Sweden)

    Savithiri S

    2011-01-01

    Full Text Available Abstract The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of slip mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it.

  14. Scaling analysis for the investigation of slip mechanisms in nanofluids

    Science.gov (United States)

    Savithiri, S.; Pattamatta, Arvind; Das, Sarit K.

    2011-07-01

    The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of slip mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it.

  15. Dynamic Response of Linear Mechanical Systems Modeling, Analysis and Simulation

    CERN Document Server

    Angeles, Jorge

    2012-01-01

    Dynamic Response of Linear Mechanical Systems: Modeling, Analysis and Simulation can be utilized for a variety of courses, including junior and senior-level vibration and linear mechanical analysis courses. The author connects, by means of a rigorous, yet intuitive approach, the theory of vibration with the more general theory of systems. The book features: A seven-step modeling technique that helps structure the rather unstructured process of mechanical-system modeling A system-theoretic approach to deriving the time response of the linear mathematical models of mechanical systems The modal analysis and the time response of two-degree-of-freedom systems—the first step on the long way to the more elaborate study of multi-degree-of-freedom systems—using the Mohr circle Simple, yet powerful simulation algorithms that exploit the linearity of the system for both single- and multi-degree-of-freedom systems Examples and exercises that rely on modern computational toolboxes for both numerical and symbolic compu...

  16. Biological Jumping Mechanism Analysis and Modeling for Frog Robot

    Institute of Scientific and Technical Information of China (English)

    Meng Wang; Xi-zhe Zang; Ji-zhuang Fan; Jie Zhao

    2008-01-01

    This paper presents a mechanical model of jumping robot based on the biological mechanism analysis of frog. By biological observation and kinematic analysis the frog jump is divided into take-off phase, aerial phase and landing phase. We find the similar trajectories of hindlimb joints during jump, the important effect of foot during take-off and the role of forelimb in supporting the body. Based on the observation, the frog jump is simplified and a mechanical model is put forward. The robot leg is represented by a 4-bar spring/linkage mechanism model, which has three Degrees of Freedom (DOF) at hip joint and one DOF (passive) at tarsometatarsal joint on the foot. The shoulder and elbow joints each has one DOF for the balancing function of arm.The ground reaction force of the model is analyzed and compared with that of frog during take-off. The results show that the model has the same advantages of low likelihood of premature lift-off and high efficiency as the frog. Analysis results and the model can be employed to develop and control a robot capable of mimicking the jumping behavior of flog.

  17. Multiple regression analysis of urinary fluoride, s aliva and plaque fluoride levels of adolescents dental fluorosis%氟斑牙青少年尿氟与唾液氟及菌斑氟的相关性分析

    Institute of Scientific and Technical Information of China (English)

    于阳阳; 赵伟; 刘晓燕; 邹冬荣; 杨晓昀; 刘荣; 于晓峰; 营杰

    2016-01-01

    Objective The purpose of this study was to study the correlation between dental fluorosis, saliva and plaque fluoride levels and urinary fluoride values in adolescents dental fluorosis. Methods A middle school was chosen as a survey point in the study. Two hundred adolescents were examined the degree of dental fluorosis by Dean's method. These adolescents were divided into four groups according to the severity of fluorosis (n = 52, 40, 28 and 80). Fluoride ion specific electrode was used to measure the fluoride levels in dental plaque, saliva, urinary and drinking water. The differences were analyzed b y ANOVA. Correlation of the fluoride levels between dental plaque, saliva, urine and the degree of dental fluorosis were analyzed by the method of multiple linear regression. Results The average fluoride content of drinking water was (2.20 ± 0.40) mg/L. Compared with controls, the fluoride concentrations in dental plaque, saliva and urine were higher in light, medium and severe dental fluorosis groups [(1.55 ± 0.88), (1.94 ± 0.77), (2.74 ± 0.83) than (0.32 ± 0.20) mg/L; (4.44 ± 1.62), (8.09 ± 0.93), (10.72 ± 0.99) than (0.02 ± 0.01) mg/L;(31.77 ± 6.09), (57.98 ± 1.83), (65.98 ± 2.78) than (13.06 ± 2.11) μg/g, all P<0.05]. Urinary fluoride was correlated with fluoride in saliva and dental plaque (r=0.245, 0.440, all P<0.05). Saliva fluoride was correlated with fluoride in dental plaque (r=0.849, P<0.01). The degree of dental fluorosis was correlated with fluoride in urine and saliva (r = 0.497, 0.896, 0.924, all P< 0.01). The multiple linear regression equation between fluoride in urine and the degree of dent al fluorosis, fluoride in dental plaque and saliva was as follow: y = 1.357 + 1.618x1 + 0.001x2 - 0.331x3 ± 0.69. Conclusions The metabolism of fluoride in body is related with oral fluoride repository in adolescents dental fluorosis. Fluoride in urine is influenced by plaque fluoride level, saliva fluoride concentration and the degree of dental

  18. 普萘洛尔对肾上腺素促大鼠动脉粥样硬化斑块进展的保护作用及其机制的研究%Investigation of the mechanisms of protective effect of propranolol on the progression of atherosclerotic plaque in rats caused by epinephrine

    Institute of Scientific and Technical Information of China (English)

    周敬群; 周军; 董勇; 曾秋棠; 杨维华

    2011-01-01

    Objective:To investigate the mechanisms of protective effect of propranolol on the progression of atherosclerotic plaque, and to study the changes of expression of CD68 and matrix metalloproteinase 9 (MMP 9) in rats caused by epinephrine. Methods:50 male Wistar rats were fed with high cholesterol diet for 17 weeks to estab lish atherosclerotic model. Then, they were randomly divided into five groups: control group, epinephrine group, propranolol group A, propranolol group B and propranolol group C (10 rats each group). All groups were contin uously fed with high cholesterol diet. At the same time, control group rats were treated with 0. 9% sodium chlo ride 0. 5 ml/d, ih; epinephrine group rats were treated with epinephrine 0. 5 mg/kg ? D, ih; propranolol groups were pretreated with propranolol (group A 2. 5 mg/kg ? D; group B 5 mg/kg ? D; group C 7. 5 mg/kg ? D) before 30 minutes treatment with epinephrine. After one week, the expressions of CD68 and MMP 9 in the artery athero sclerotic plaque were examined by immunohistochemistry. Results: Compared with control group, the expressions of CD68 and MMP 9 in epinephrine group were significantly increased (P<0. 05). Compared with epinephrine group, propranolol groups showed that the expressions of CD68 and MMP 9 in atherosclerotic plaque decreased significantly (P<0. 05). Among propranolol groups, with the increase of the propranolol dose, the positive ex pression of CD68 and MMP 9 were decreased, but no significant difference were observed. Conclusion:Propranolol can delay the progression of atherosclerotic plaque which may due to its effect to attenuate the macrophage infiltra tion and MMP 9 expression induced by epinephrine.%目的:探讨普萘洛尔对肾上腺素促大鼠动脉粥样硬化斑块进展的预防作用及其机制.方法:50只Wistar雄性大鼠经高脂喂养17周,制成动脉粥样硬化模型.随机分为对照组、肾上腺素组、普萘洛尔小剂量组、普萘洛尔中剂量组、

  19. Mechanism of Residual Lumen Stenosis at the Side Branch Ostium After Final Kissing Balloon Inflation: A Volumetric Intracoronary Ultrasound Study of Coronary Bifurcation Lesions.

    Science.gov (United States)

    Yamawaki, Masahiro; Murasato, Yoshinobu; Kinoshita, Yoshihisa; Fujii, Kenichi; Fujino, Yoshihisa; Shinke, Toshiro; Takeda, Yoshihiro; Yamada, Shinichiro; Shimada, Yoshihisa; Tsukahara, Reiko; Muramatsu, Toshiya; Suzuki, Takahiko

    2016-04-01

    To investigate the mechanisms of residual stenosis (RS) at side branch ostium (SBO) after final kissing balloon inflation (FKI) and clarify the impact of carina- and plaque-shifts on RS. Carina- and plaque-shift induce SBO compromise. FKI is an effective technique to treat this complication; however, RS often persist, and are associated with restenosis at SBO. We performed serial volumetric analysis of 91 bifurcations in which crossover-stenting with FKI and pre-/post-intravascular ultrasounds (IVUS) were completed in both branches. The plaque- and carina-shifts were defined as an increase in the plaque-volume and a decrease in the vessel-volume at the SBO, respectively. RS at the SBO, defined as area stenosis >50% on IVUS, was identified in 19 lesions. After FKI, the plaque volume- significantly increased at the SBO, with its reduction in the proximal main vessel (MV). However, at the SBO, the volumetric lumen change correlated with vessel change (ρ = 0.690, P < 0.001), but not plaque change (P = 0.390), suggesting that RS at SBO was more likely associated with inadequate vessel stretch, not plaque increase after FKI. Carina-shift was more frequently found in cases with RS, compared to those without RS (37% vs. 11%, P = 0.013). Pre-procedure IVUS findings to predict RS at SBO after FKI were negative-remodeling at distal MV, plaque -burden at distal MV, and plaque-burden at the SBO. Carina-shift has a greater contribution to the formation of RS at SBO after FKI. The pre-procedure IVUS provides helpful information for predicting the RS after FKI. © 2016, Wiley Periodicals, Inc.

  20. Non-linear finite element analysis in structural mechanics

    CERN Document Server

    Rust, Wilhelm

    2015-01-01

    This monograph describes the numerical analysis of non-linearities in structural mechanics, i.e. large rotations, large strain (geometric non-linearities), non-linear material behaviour, in particular elasto-plasticity as well as time-dependent behaviour, and contact. Based on that, the book treats stability problems and limit-load analyses, as well as non-linear equations of a large number of variables. Moreover, the author presents a wide range of problem sets and their solutions. The target audience primarily comprises advanced undergraduate and graduate students of mechanical and civil engineering, but the book may also be beneficial for practising engineers in industry.

  1. Hygrothermal effect of bamboo by dynamic mechanical analysis

    Institute of Scientific and Technical Information of China (English)

    GUAN Mingjie; ZHANG Qisheng

    2006-01-01

    Dynamic properties of bamboo,Phyllostachys pubescens,with moisture content (MC) ranging from -130 to 130℃,were studied by dynamic mechanical analysis (DMA).The results showed that the hygrothermal effect on dynamic mechanical properties was negative.The storage modulus decreases with increasing temperature and MC,and glass transition temperature decreases with increasing MC.The glass transition temperature and tan delta of bamboo were 30.5℃,0.02 and 10.61℃,0.04,when MC was 10% and 34%,respectively.

  2. Mechanical network in titin immunoglobulin from force distribution analysis.

    Directory of Open Access Journals (Sweden)

    Wolfram Stacklies

    2009-03-01

    Full Text Available The role of mechanical force in cellular processes is increasingly revealed by single molecule experiments and simulations of force-induced transitions in proteins. How the applied force propagates within proteins determines their mechanical behavior yet remains largely unknown. We present a new method based on molecular dynamics simulations to disclose the distribution of strain in protein structures, here for the newly determined high-resolution crystal structure of I27, a titin immunoglobulin (IG domain. We obtain a sparse, spatially connected, and highly anisotropic mechanical network. This allows us to detect load-bearing motifs composed of interstrand hydrogen bonds and hydrophobic core interactions, including parts distal to the site to which force was applied. The role of the force distribution pattern for mechanical stability is tested by in silico unfolding of I27 mutants. We then compare the observed force pattern to the sparse network of coevolved residues found in this family. We find a remarkable overlap, suggesting the force distribution to reflect constraints for the evolutionary design of mechanical resistance in the IG family. The force distribution analysis provides a molecular interpretation of coevolution and opens the road to the study of the mechanism of signal propagation in proteins in general.

  3. [Development of Fluorescence Sensing Mechanism for Cell Functional Analysis].

    Science.gov (United States)

    Ojida, Akio; Takashima, Ippei

    2016-01-01

      Fluorescence probes are now widely used as indispensable tools in many cell functional analyses. At present, the design of fluorescent probes largely depends on the limited numbers of established sensing mechanisms such as photo-induced electron transfer (PET), photo-induced charge transfer (PCT), and fluorescence resonance energy transfer (FRET). Although these mechanisms are versatile in metal ion sensing, introduction of a new sensing mechanism is highly desirable not only to design a more sophisticated probe with high selectivity and sensitivity but also to expand the diversity of the sensing targets to unveil biological phenomena. In this article, we report the design of dual emission fluorescent probes for metal ions based on a unique fluorescence-sensing mechanism. The fluorescent probes incorporating this sensing mechanism displayed a large emission red-shift on complexation with metal ions such as Cd(II) and Ag(I). X-ray crystallography and theoretical computational calculations of the Cd(II) and Ag(I) complexes revealed that the emission shift was induced by non-coordination contact between the aromatic ring of fluorophore and the metal ion (arene-metal ion contact; AM-contact), which modulates the energy levels of molecular orbitals. The fluorescent probe was successfully applied to in cell ratiometric bioimaging of bioactive hydrogen sulfide (H2S). These successful applications highlight the usefulness of this sensing mechanism in biological fluorescence analysis.

  4. Analysis of nematode mechanics by piezoresistive displacement clamp.

    Science.gov (United States)

    Park, Sung-Jin; Goodman, Miriam B; Pruitt, Beth L

    2007-10-30

    Studying animal mechanics is critical for understanding how signals in the neuromuscular system give rise to behavior and how force-sensing organs and sensory neurons work. Few techniques exist to provide forces and displacements appropriate for such studies. To address this technological gap, we developed a metrology using piezoresistive cantilevers as force-displacement sensors coupled to a feedback system to apply and maintain defined load profiles to micrometer-scale animals. We show that this system can deliver forces between 10(-8) and 10(-3) N across distances of up to 100 mum with a resolution of 12 nN between 0.1 Hz and 100 kHz. We use this new metrology to show that force-displacement curves of wild-type nematodes (Caenorhabditis elegans) are linear. Because nematodes have approximately cylindrical bodies, this finding demonstrates that nematode body mechanics can be modeled as a cylindrical shell under pressure. Little is known about the relative importance of hydrostatic pressure and shell mechanics, however. We show that dissipating pressure by cuticle puncture or decreasing it by hyperosmotic shock has only a modest effect on stiffness, whereas defects in the dpy-5 and lon-2 genes, which alter body shape and cuticle proteins, decrease and increase stiffness by 25% and 50%, respectively. This initial analysis of C. elegans body mechanics suggests that shell mechanics dominates stiffness and is a first step in understanding how body mechanics affect locomotion and force sensing.

  5. Terahertz mechanical vibrations in lysozyme: Raman spectroscopy vs modal analysis

    Science.gov (United States)

    Carpinteri, Alberto; Lacidogna, Giuseppe; Piana, Gianfranco; Bassani, Andrea

    2017-07-01

    The mechanical behaviour of proteins is receiving an increasing attention from the scientific community. Recently it has been suggested that mechanical vibrations play a crucial role in controlling structural configuration changes (folding) which govern proteins biological function. The mechanism behind protein folding is still not completely understood, and many efforts are being made to investigate this phenomenon. Complex molecular dynamics simulations and sophisticated experimental measurements are conducted to investigate protein dynamics and to perform protein structure predictions; however, these are two related, although quite distinct, approaches. Here we investigate mechanical vibrations of lysozyme by Raman spectroscopy and linear normal mode calculations (modal analysis). The input mechanical parameters to the numerical computations are taken from the literature. We first give an estimate of the order of magnitude of protein vibration frequencies by considering both classical wave mechanics and structural dynamics formulas. Afterwards, we perform modal analyses of some relevant chemical groups and of the full lysozyme protein. The numerical results are compared to experimental data, obtained from both in-house and literature Raman measurements. In particular, the attention is focused on a large peak at 0.84 THz (29.3 cm-1) in the Raman spectrum obtained analyzing a lyophilized powder sample.

  6. Assessment of plaque assay methods for alphaviruses.

    Science.gov (United States)

    Juarez, Diana; Long, Kanya C; Aguilar, Patricia; Kochel, Tadeusz J; Halsey, Eric S

    2013-01-01

    Viruses from the Alphavirus genus are responsible for numerous arboviral diseases impacting human health throughout the world. Confirmation of acute alphavirus infection is based on viral isolation, identification of viral RNA, or a fourfold or greater increase in antibody titers between acute and convalescent samples. In convalescence, the specificity of antibodies to an alphavirus may be confirmed by plaque reduction neutralization test. To identify the best method for alphavirus and neutralizing antibody recognition, the standard solid method using a cell monolayer overlay with 0.4% agarose and the semisolid method using a cell suspension overlay with 0.6% carboxymethyl cellulose (CMC) overlay were evaluated. Mayaro virus, Una virus, Venezuelan equine encephalitis virus (VEEV), and Western equine encephalitis virus (WEEV) were selected to be tested by both methods. The results indicate that the solid method showed consistently greater sensitivity than the semisolid method. Also, a "semisolid-variant method" using a 0.6% CMC overlay on a cell monolayer was assayed for virus titration. This method provided the same sensitivity as the solid method for VEEV and also had greater sensitivity for WEEV titration. Modifications in plaque assay conditions affect significantly results and therefore evaluation of the performance of each new assay is needed.

  7. Concept of Remission in Chronic Plaque Psoriasis.

    Science.gov (United States)

    Gisondi, Paolo; Di Mercurio, Marco; Idolazzi, Luca; Girolomoni, Giampiero

    2015-11-01

    Psoriasis is a lifelong chronic inflammatory disease affecting 2-3% of the worldwide population. Current understanding of the pathogenesis of psoriasis assigns central importance to an interaction between acquired and innate immunity. The disease is characterized by a series of linked cellular changes in the skin, including hyperplasia of epidermal keratinocytes, angiogenesis, and infiltration of T lymphocytes, neutrophils, and other types of leukocytes in the affected skin. Plaque psoriasis is the most common clinical form and is characterized by red and scaly plaques generally localized at extensor sites such as elbows and knees. Major determinants of psoriasis severity include the extent of skin involvement; localization in highly affected areas such as scalp, palms, and soles; pruritus; presence of comorbidities including psoriatic arthritis; and impairment on quality of life. About one-third of patients have moderate to severe psoriasis defined as PASI (Psoriasis Area and Severity Index) and/or Dermatology Life Quality Index>10, and/or affected body surface area>10%. The optimal treatment goal is to safely achieve complete or almost complete skin clearance. Treatments available are various and they are chosen according to disease features, comorbidities, and patient characteristics and priorities. Topical treatments including corticosteroids and Vitamin D analogs are reserved for mild disease. Phototherapy, cyclosporine, methotrexate, acitretin, or biologics such as tumor necrosis factor-α antagonists and ustekinumab are reserved for the moderate to severe forms.

  8. The effect of iron plaque on uptake and translocation of norfloxacin in rice seedlings grown in paddy soil.

    Science.gov (United States)

    Yan, Dafang; Ma, Wei; Song, Xiaojing; Bao, Yanyu

    2017-03-01

    Although the role of iron plaque on rice root surface has been investigated in recent years, its effect on antibiotic uptake remains uncertain. In the study, pot experiment was conducted to investigate the effect of iron plaque on uptake and translocation of norfloxacin (adding 10 and 50 mg·kg(-1) treatments) in rice seedlings grown in paddy soil. Iron plaque was induced by adding different amounts of Fe(II) in soil. The results showed that the presence of norfloxacin can decrease the amount of iron plaque induced. After rice with iron plaque induced, norfloxacin was mainly accumulated in iron plaque on root surface, followed by inside root, but its translocation from root to other rice tissues is not observed. Iron plaque played the role of a barrier for norfloxacin uptake into rice roots under high norfloxacin concentration of 50 mg·kg(-1), however not that under low concentration of 10 mg·kg(-1). And the barrier function was the most strongest with adding Fe(II) of 30 mg·kg(-1) as combined action of iron plaque and rhizosphere effect. Fluorescence microscope analysis showed that norfloxacin mainly distributed in the outside of root cell, which showed its translocation as apoplastic pathway in rice. Comparing with non-rhizosphere, more norfloxacin was accumulated in rhizosphere soil. Maybe, strong root oxidization (high Eh values) induced more iron oxide formation in rhizosphere and on root surface, which led to norfloxacin's mobility towards to rhizosphere through its strong adsorption of iron oxides and then promoted its uptake by rice on root surface.

  9. Association between serum vitamin D levels and subclinical coronary atherosclerosis and plaque burden/composition in young adult population

    Directory of Open Access Journals (Sweden)

    Seckin Satilmis

    2015-02-01

    Full Text Available Evidence suggests that low 25-OH vitamin D 25(OHD concentrations may increase the risk of several cardiovascular diseases such as hypertension, peripheral vascular disease, diabetes mellitus, obesity, myocardial infarction, heart failure and cardiovascular mortality. Recent studies suggested a possible relationship between vitamin D deficiency and increased carotid intima-media wall thickness and vascular calcification. We hypothesized that low 25(OHD may be associated with coronary atherosclerosis and coronary plaque burden and composition, and investigated the relationship between serum vitamin D levels and coronary atherosclerosis, plaque burden or structure, in young adult patients by using dual-source 128x2 slice coronary computed tomography angiography (CCTA. We included 98 patients with coronary atherosclerosis and 110, age and gender matched, subjects with normal findings on CCTA examinations. Patients with subclinical atherosclerosis had significantly higher serum total cholesterol, triglycerides, hs-CRP, uric acid, HbA1c and creatinine levels and lower serum 25(OHD levels in comparison with controls. There was no significant correlation between 25(OHD and plaque morphology. There was also a positive relationship between 25(OHD and plaque burden of coronary atherosclerosis. In multivariate analysis, coronary atherosclerosis was associated high hs-CRP (adjusted OR: 2.832, uric acid (adjusted OR: 3.671 and low 25(OHD (adjusted OR: 0.689. Low levels of 25(OHD were associated with coronary atherosclerosis and plaque burden, but there was no significant correlation between 25(OHD and plaque morphology.

  10. Effect of reader experience on variability, evaluation time and accuracy of coronary plaque detection with computed tomography coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Saur, Stefan C.; Szekely, Gabor [ETH Zurich, Computer Vision Laboratory, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Group, Boston, MA (United States); Stolzmann, Paul; Baumueller, Stephan; Leschka, Sebastian; Scheffel, Hans; Desbiolles, Lotus [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Fuchs, Thomas J. [ETH Zurich, Department of Computer Science, Zurich (Switzerland); Cattin, Philippe C. [ETH Zurich, Computer Vision Laboratory, Zurich (Switzerland); University of Basel, Medical Image Analysis Center, Basel (Switzerland)

    2010-07-15

    To assess the effect of reader experience on variability, evaluation time and accuracy in the detection of coronary artery plaques with computed tomography coronary angiography (CTCA). Three independent, blinded readers with three different experience levels twice labelled 50 retrospectively electrocardiography (ECG)-gated contrast-enhanced dual-source CTCA data sets (15 female, age 67.3 {+-} 10.4 years, range 46-86 years) indicating the presence or absence of coronary plaques. The evaluation times for the readings were recorded. Intra- and interobserver variability expressed as {kappa} statistics and sensitivity, specificity, and negative and positive predictive values were calculated for plaque detection, with a consensus reading of the three readers taken as the standard of reference. A bootstrap method was applied in the statistical analysis to account for clustering. Significant correlations were found between reader experience and, respectively, evaluation times (r = -0.59, p < 0.05) and intraobserver variability (r = 0.73, p < 0.05). The evaluation time significantly differed among the readers (p < 0.05). The observer variability for plaque detection, compared with the consensus, varied between {kappa} = 0.582 and {kappa} = 0.802. Variability of plaque detection was significantly smaller (p < 0.05) and more accurate (p < 0.05) for the most experienced reader. Reader experience significantly correlated with observer variability, evaluation time and accuracy of coronary plaque detection at CTCA. (orig.)

  11. Prediction of coronary plaque location on arteries having myocardial bridge, using finite element models.

    Science.gov (United States)

    Nikolić, Dalibor; Radović, Miloš; Aleksandrić, Srđan; Tomašević, Miloje; Filipović, Nenad

    2014-11-01

    This study was performed to evaluate the influences of the myocardial bridges on the plaque initializations and progression in the coronary arteries. The wall structure is changed due to the plaque presence, which could be the reason for multiple heart malfunctions. Using simplified parametric finite element model (FE model) of the coronary artery having myocardial bridge and analyzing different mechanical parameters from blood circulation through the artery (wall shear stress, oscillatory shear index, residence time), we investigated the prediction of "the best" position for plaque progression. We chose six patients from the angiography records and used data from DICOM images to generate FE models with our software tools for FE preprocessing, solving and post-processing. We found a good correlation between real positions of the plaque and the ones that we predicted to develop at the proximal part of the myocardial bridges with wall shear stress, oscillatory shear index and residence time. This computer model could be additional predictive tool for everyday clinical examination of the patient with myocardial bridge.

  12. Dental plaque development on a hydroxyapatite disk in young adults observed by using a barcoded pyrosequencing approach.

    Science.gov (United States)

    Takeshita, Toru; Yasui, Masaki; Shibata, Yukie; Furuta, Michiko; Saeki, Yoji; Eshima, Nobuoki; Yamashita, Yoshihisa

    2015-01-30

    Dental plaque is a dynamic microbial biofilm ecosystem that comprises hundreds of species including difficult-to-cultivate bacteria. We observed the assembly of a plaque bacterial community through 16S rRNA gene analysis. Plaque samples that accumulated on a hydroxyapatite disk for 1, 2, 3, 4, 5, and 7 days with saliva on day 0 were collected from 19 young adults using a removable resin splint. Quantitative PCR analysis showed that the total bacterial amount gradually increased and reached a plateau on day 4. Barcoded pyrosequencing analysis revealed that the microbial richness and diversity particularly increased between days 5 and 7. A principal coordinate analysis plot based on unweighted UniFrac showed the community assembly in a time-related manner, which became increasingly similar to the salivary microbiota. Facultative anaerobic bacteria such as Streptococcus, Neisseria, Abiotrophia, Gemella, and Rothia were predominant in the plaque bacterial community in the earlier days, whereas obligate anaerobes, such as Porphyromonas, Fusobacterium, Prevotella, and Capnocytophaga showed increased dominance on later days. UniFrac analysis also demonstrated that dental caries experience had a significant effect on the assembly process. Our results reveal the development pattern of the plaque bacterial community as well as the inter-individual differences associated with dental caries experience.

  13. Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

    Science.gov (United States)

    Iyer, Nageshwar; Chandna, Shalu; Dhindsa, Abhishek; Damle, Dhanashree; Loomba, Ashish

    2016-01-01

    Aim: The aim of this clinical study was to confirm the plaque removal efficacy of the Colgate 360 Whole Mouth Clean Toothbrush. Study Design: This was a single-center, monadic, case–controlled study with the 7 days duration. Materials and Methods: A total of eighty participants (56 male and 24 female) aged between 18 and 45 years with a minimum of 20 permanent teeth (excluding the third molars) without any prosthetic crowns and an initial plaque score of minimum 1.5 as determined by Modified Quigley-Hein Plaque Index (1970) participated in the study. There were two dropouts during the study duration, one male and one female. The participants were instructed to brush for 1 min, after which plaque index was recorded again. They were then instructed to brush their teeth twice a day for 1 min with the assigned toothbrush (Colgate 360 Whole Mouth Clean Toothbrush) and a commercially available fluoride toothpaste for the next 7 days. On the 7th day, all the participants were recalled for follow-up and plaque examination. The plaque index scores (pre- and post-brushing) were recorded, tabulated, and analyzed statistically. Results: The mean plaque indices reduced after brushing both on day 1 and day 7. There was also a reduction in mean plaque indices from day 1 to day 7. All these reductions were statistically significant (P < 0.001). The reduction in plaque scores was independent of the gender of the participants however female participants showed lower scores as compared to male participants (P < 0.001). Conclusion: The present study demonstrated a significant reduction in plaque scores with the use of Colgate 360 Whole Mouth Clean Soft Toothbrush throughout the study period. Continued use resulted in a further significant reduction in plaque scores irrespective of the gender of participants. PMID:27630494

  14. Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

    Directory of Open Access Journals (Sweden)

    Nageshwar Iyer

    2016-01-01

    Full Text Available Aim: The aim of this clinical study was to confirm the plaque removal efficacy of the Colgate 360 Whole Mouth Clean Toothbrush. Study Design: This was a single-center, monadic, case-controlled study with the 7 days duration. Materials and Methods: A total of eighty participants (56 male and 24 female aged between 18 and 45 years with a minimum of 20 permanent teeth (excluding the third molars without any prosthetic crowns and an initial plaque score of minimum 1.5 as determined by Modified Quigley-Hein Plaque Index (1970 participated in the study. There were two dropouts during the study duration, one male and one female. The participants were instructed to brush for 1 min, after which plaque index was recorded again. They were then instructed to brush their teeth twice a day for 1 min with the assigned toothbrush (Colgate 360 Whole Mouth Clean Toothbrush and a commercially available fluoride toothpaste for the next 7 days. On the 7 th day, all the participants were recalled for follow-up and plaque examination. The plaque index scores (pre- and post-brushing were recorded, tabulated, and analyzed statistically. Results: The mean plaque indices reduced after brushing both on day 1 and day 7. There was also a reduction in mean plaque indices from day 1 to day 7. All these reductions were statistically significant (P < 0.001. The reduction in plaque scores was independent of the gender of the participants however female participants showed lower scores as compared to male participants (P < 0.001. Conclusion: The present study demonstrated a significant reduction in plaque scores with the use of Colgate 360 Whole Mouth Clean Soft Toothbrush throughout the study period. Continued use resulted in a further significant reduction in plaque scores irrespective of the gender of participants.

  15. Analysis of Stability and Bifurcation in Nonlinear Mechanics with Dissipation

    Directory of Open Access Journals (Sweden)

    Claude Stolz

    2011-01-01

    Full Text Available The analysis of stability and bifurcation is studied in nonlinear mechanics with dissipative mechanisms: plasticity, damage, fracture. The description is based on introduction of a set of internal variables. This framework allows a systematic description of the material behaviour via two potentials: the free energy and the potential of dissipation. In the framework of standard generalized materials the internal state evolution is governed by a variational inequality which depends on the mechanism of dissipation. This inequality is obtained through energetic considerations in an unified description based upon energy and driving forces associated to the dissipative process. This formulation provides criterion for existence and uniqueness of the system evolution. Examples are presented for plasticity, fracture and for damaged materials.

  16. Sensitivity analysis of GSI based mechanical characterization of rock mass

    CERN Document Server

    Ván, P

    2012-01-01

    Recently, the rock mechanical and rock engineering designs and calculations are frequently based on Geological Strength Index (GSI) method, because it is the only system that provides a complete set of mechanical properties for design purpose. Both the failure criteria and the deformation moduli of the rock mass can be calculated with GSI based equations, which consists of the disturbance factor, as well. The aim of this paper is the sensitivity analysis of GSI and disturbance factor dependent equations that characterize the mechanical properties of rock masses. The survey of the GSI system is not our purpose. The results show that the rock mass strength calculated by the Hoek-Brown failure criteria and both the Hoek-Diederichs and modified Hoek-Diederichs deformation moduli are highly sensitive to changes of both the GSI and the D factor, hence their exact determination is important for the rock engineering design.

  17. Forward Position Analysis of 5-DOF Parallel Mechanism

    Institute of Scientific and Technical Information of China (English)

    QI Ming; MEI Jiangping

    2006-01-01

    A systematic method for the forward kinematics of a five degrees of freedom (5-DOF)parallel mechanism with the legs'topology 4-UPS/UPU,is developed.Such mechanism is composed of a movable platform connected to the base by four identical 6-DOF active limbs plus one active limb with its DOF being exactly the same as the specified DOF of the movable platform.Three translational and two rotational DOFs can be achieved.Firstly,a set of polynomial equations of forward position analysis is formulated based on the architecture of the mechanism.Then the system of equations is degraded from five-dimensional to three-dimensional by means of analytic elimination.Method of least squares and Gauss-Newton algorithm are used to construct the objective function and to solve it,respectively.Example shows that through 4-time iteration within 16 ms the objective function converges to the provided error tolerance,10 -4.

  18. Conformational analysis of small molecules: NMR and quantum mechanics calculations.

    Science.gov (United States)

    Tormena, Cláudio F

    2016-08-01

    This review deals with conformational analysis in small organic molecules, and describes the stereoelectronic interactions responsible for conformational stability. Conformational analysis is usually performed using NMR spectroscopy through measurement of coupling constants at room or low temperature in different solvents to determine the populations of conformers in solution. Quantum mechanical calculations are used to address the interactions responsible for conformer stability. The conformational analysis of a large number of small molecules is described, using coupling constant measurements in different solvents and at low temperature, as well as recent applications of through-space and through-hydrogen bond coupling constants JFH as tools for the conformational analysis of fluorinated molecules. Besides NMR parameters, stereoelectronic interactions such as conjugative, hyperconjugative, steric and intramolecular hydrogen bond interactions involved in conformational preferences are discussed.

  19. Delineation of atherosclerotic plaque using subharmonic imaging filtering techniques and a commercial intravascular ultrasound system.

    Science.gov (United States)

    Sridharan, Anush; Eisenbrey, John R; Machado, Priscilla; deMuinck, Ebo D; Doyley, Marvin M; Forsberg, Flemming

    2013-01-01

    The ability to delineate atherosclerotic plaque from the surrounding tissue using custom-developed subharmonic imaging (SHI) digital filtering techniques was investigated in vivo using a commercially available system. Atherosclerosis was induced in the aorta of two Watanabe Heritable Hyperlipidemic rabbits following which injections of an ultrasound contrast agent (UCA) Definity (Lantheus Medical Imaging, N Billerica, Massachusetts) were administered. Imaging was performed using a Galaxy intravascular ultrasound (IVUS) scanner (Boston Scientific, Natick, Massachusetts) equipped with an Atlantis® SR Pro Imaging Catheter (Boston Scientific). Four preliminary band-pass filters were designed to isolate the subharmonic signal (from surrounding tissue) and applied to the radio-frequency (RF) data. Preliminary filter performances were compared in terms of vessel-tissue contrast-to-tissue ratio (CTR) and visual examination. Based on preliminary results, a subharmonic adaptive filter and a stopband (SB) filter were designed and applied to the RF data. Images were classified as fundamental, SHI, and SB. Four readers performed qualitative analysis of 168 randomly selected images (across all three imaging modes). The images were scored for overall image quality, image noise, plaque visualization, and vessel lumen visualization. A Wilcoxon signed-rank test was used to compare the scores followed by intraclass correlation (ICC) evaluation. Quantitative analysis was performed by calculating the CTRs for the vessel-to-plaque and vessel-to-tissue (compared using a paired student's t test). Qualitative analysis showed SHI and SB to have significantly less image noise relative to the fundamental mode (p < 0.001). Fundamental mode scored significantly higher than SHI and SB for the remaining three categories. ICC showed mixed results among reader evaluation for delineation of plaque. However, quantitatively, SHI produced the best vessel-plaque CTR.

  20. Antieigenvalue analysis for continuum mechanics, economics, and number theory

    Directory of Open Access Journals (Sweden)

    Gustafson Karl

    2016-01-01

    Full Text Available My recent book Antieigenvalue Analysis, World-Scientific, 2012, presented the theory of antieigenvalues from its inception in 1966 up to 2010, and its applications within those forty-five years to Numerical Analysis, Wavelets, Statistics, Quantum Mechanics, Finance, and Optimization. Here I am able to offer three further areas of application: Continuum Mechanics, Economics, and Number Theory. In particular, the critical angle of repose in a continuum model of granular materials is shown to be exactly my matrix maximum turning angle of the stress tensor of the material. The important Sharpe ratio of the Capital Asset Pricing Model is now seen in terms of my antieigenvalue theory. Euclid’s Formula for Pythagorean triples becomes a special case of my operator trigonometry.

  1. Classical mechanics approach applied to analysis of genetic oscillators.

    Science.gov (United States)

    Vasylchenkova, Anastasiia; Mraz, Miha; Zimic, Nikolaj; Moskon, Miha

    2016-04-05

    Biological oscillators present a fundamental part of several regulatory mechanisms that control the response of various biological systems. Several analytical approaches for their analysis have been reported recently. They are, however, limited to only specific oscillator topologies and/or to giving only qualitative answers, i.e., is the dynamics of an oscillator given the parameter space oscillatory or not. Here we present a general analytical approach that can be applied to the analysis of biological oscillators. It relies on the projection of biological systems to classical mechanics systems. The approach is able to provide us with relatively accurate results in the meaning of type of behaviour system reflects (i.e. oscillatory or not) and periods of potential oscillations without the necessity to conduct expensive numerical simulations. We demonstrate and verify the proposed approach on three different implementations of amplified negative feedback oscillator.

  2. Pyrosequencing of Plaque Microflora In Twin Children with Discordant Caries Phenotypes.

    Directory of Open Access Journals (Sweden)

    Meng Zhang

    Full Text Available Despite recent successes in the control of dental caries, the mechanism of caries development remains unclear. To investigate the causes of dental decay, especially in early childhood caries, the supragingival microflora composition of 20 twins with discordant caries phenotypes were analyzed using high-throughput pyrosequencing. In addition, the parents completed a lifestyle questionnaire. A total of 228,789 sequencing reads revealed 10 phyla, 84 genera, and 155 species of microflora, the relative abundances of these strains varied dramatically among the children, Comparative analysis between groups revealed that Veillonella, Corynebacterium and Actinomyces were presumed to be caries-related genera, Fusobacterium, Kingella and Leptotrichia were presumed to be healthy-related genus, yet this six genera were not statistically significant (P>0.05. Moreover, a cluster analysis revealed that the microbial composition of samples in the same group was often dissimilar but that the microbial composition observed in twins was usually similar. Although the genetic and environmental factors that strongly influence the microbial composition of dental caries remains unknown, we speculate that genetic factors primarily influence the individual's susceptibility to dental caries and that environmental factors primarily regulate the microbial composition of the dental plaque and the progression to caries. By using improved twins models and increased sample sizes, our study can be extended to analyze the specific genetic and environmental factors that affect the development of caries.

  3. Parametric Design and Mechanical Analysis of Beams based on SINOVATION

    Science.gov (United States)

    Xu, Z. G.; Shen, W. D.; Yang, D. Y.; Liu, W. M.

    2017-07-01

    In engineering practice, engineer needs to carry out complicated calculation when the loads on the beam are complex. The processes of analysis and calculation take a lot of time and the results are unreliable. So VS2005 and ADK are used to develop a software for beams design based on the 3D CAD software SINOVATION with C ++ programming language. The software can realize the mechanical analysis and parameterized design of various types of beams and output the report of design in HTML format. Efficiency and reliability of design of beams are improved.

  4. CISM Course on Analysis and Estimation of Stochastic Mechanical Systems

    CERN Document Server

    Wedig, Walter

    1988-01-01

    This book summarizes the developments in stochastic analysis and estimation. It presents novel applications to practical problems in mechanical systems. The main aspects of the course are random vibrations of discrete and continuous systems, analysis of nonlinear and parametric systems, stochastic modelling of fatigue damage, parameter estimation and identification with applications to vehicle road systems and process simulations by means of autoregressive models. The contributions will be of interest to engineers and research workers in industries and universities who want first hand information on present trends and problems in this topical field of engineering dynamics.

  5. Summary of fracture mechanics problems analysis method in ABAQUS

    Directory of Open Access Journals (Sweden)

    Duan Hongjun

    2015-07-01

    Full Text Available Fracture mechanics is the study of the strength of the materials or structures with crack and crack propagation regularity of a discipline. There are a lot of analysis function of ABAQUS, including fracture analysis. ABAQUS is very easy to use and easy to establish a model of the complicated problem. In order to effectively study of strong discontinuity problems such as crack, provides two methods of simulating the problem of cracks of ABAQUS. This paper describes the two methods respectively, and compare two methods.

  6. Consistency analysis of accelerated degradation mechanism based on gray theory

    Institute of Scientific and Technical Information of China (English)

    Yunxia Chen; Hongxia Chen; Zhou Yang; Rui Kang; Yi Yang

    2014-01-01

    A fundamental premise of an accelerated testing is that the failure mechanism under elevated and normal stress levels should remain the same. Thus, verification of the consistency of failure mechanisms is essential during an accelerated testing. A new consistency analysis method based on the gray theory is pro-posed for complex products. First of al , existing consistency ana-lysis methods are reviewed with a focus on the comparison of the differences among them. Then, the proposed consistency ana-lysis method is introduced. Two effective gray prediction models, gray dynamic model and new information and equal dimensional (NIED) model, are adapted in the proposed method. The process to determine the dimension of NIED model is also discussed, and a decision rule is expanded. Based on that, the procedure of ap-plying the new consistent analysis method is developed. Final y, a case study of the consistency analysis of a reliability enhancement testing is conducted to demonstrate and validate the proposed method.

  7. Analysis of the mechanical behaviour of the ITER magnet system

    Energy Technology Data Exchange (ETDEWEB)

    Jong, C.T.J.

    1996-03-01

    The International Thermonuclear Experimental Reactor (ITER) is a tokamak fusion device with the objective of demonstrating controlled ignition and an extended burn for a duration sufficient to achieve stationary conditions. The design of ITER will be based on extensive new design work supported by new physical and technological results. As part of the ITER Engineering Design Activities, the mechanical behaviour of the toroidal field coil (TF coil) system during normal operating conditions and fault conditions has to be analyzed. The displacements and/or stresses in the components must be limited to prevent mechanical failure of parts of the overall structure. These Engineering Design Activities are supported by R and D programs in the European Union. This final report describes the work carried out by ECN to develop a finite element model (FE model) of the TF-coil system which is suitable for the analysis of the mechanical behaviour and presents results obtained with this model. For the analysis of the mechanical behaviour, a large three dimensional (3D) non-linear finite element model has been developed. With this FE model a large number of load cases has been analyzed which correspond with several time points during multiple pulses. (orig./WL).

  8. ANALYSIS OF THE MECHANISM MODELS OF TECHNOLOGICAL INNOVATION DIFFUSION

    Institute of Scientific and Technical Information of China (English)

    XU Jiuping; HU Minan

    2004-01-01

    This paper analyzes the mechanism and principle of diffusion of technology diffusion on the basis of quantitative analysis. Then it sets up the diffusion model of innovation incorporating price, advertising and distribution, the diffusion model of innovation including various kinds of consumers, and the substitute model between the new technology and the old one applied systems dynamics, optimization method, probabilistic method and simulation method on computer. Finally this paper concludes with some practical observations from a case study.

  9. Immunosensor with Fluid Control Mechanism for Salivary Cortisol Analysis

    OpenAIRE

    Yamaguchi, Masaki; Matsuda, Yohei; Sasaki, Shohei; Sasaki, Makoto; Kadoma, Yoshihiro; Imai, Yoshikatsu; Niwa, Daisuke; Shetty, Vivek

    2012-01-01

    The purpose of this research is to demonstrate a new design for a cortisol immunosensor for the noninvasive and quantitative analysis of salivary cortisol. We propose a cortisol immunosensor with a fluid control mechanism which has both a vertical flow and a lateral flow. The detected current resulting from a competitive reaction between the sample cortisol and a glucose oxidase (GOD)-labeled cortisol conjugate was found to be inversely related to the concentration of cortisol in the sample s...

  10. Physical quantities and dimensional analysis: from mechanics to quantum gravity

    CERN Document Server

    Trancanelli, Diego

    2015-01-01

    Physical quantities and physical dimensions are among the first concepts encountered by students in their undergraduate career. In this pedagogical review, I will start from these concepts and, using the powerful tool of dimensional analysis, I will embark in a journey through various branches of physics, from basic mechanics to quantum gravity. I will also discuss a little bit about the fundamental constants of Nature, the so-called "cube of Physics", and the natural system of units.

  11. Markers of inflammation collocate with increased wall stress in human coronary arterial plaque.

    Science.gov (United States)

    Hallow, Karen Melissa; Taylor, W Robert; Rachev, Alexander; Vito, Raymond Peter

    2009-12-01

    In this study, we hypothesized that spatial relationships exist between the local mechanical environment and inflammatory marker expression in atherosclerotic plaques, and that these relationships are plaque-progression dependent. Histologic cross-sections were collected at regular intervals along the length of diseased human coronary arteries and classified as early, intermediate, advanced, or mature based on their morphological features. For each cross-section, the spatial distribution of stress was determined using a 2D heterogeneous finite element model, and the corresponding distribution of selected inflammatory markers (macrophages, matrix metalloproteinase-1 [MMP-1], and nuclear factor-kappa B [NF-κB]) were determined immunohistochemically. We found a monotonic spatial relationship between mechanical stress and activated NF-κB that was consistent in all stages of plaque progression. We also identified progression-dependent relationships between stress and both macrophage presence and MMP-1 expression. These findings add to our understanding of the role of mechanical stress in stimulating the inflammatory response, and help explain how mechanical factors may regulate complex biological changes in remodeling.

  12. Multifractal and mechanical analysis of amorphous solid dispersions.

    Science.gov (United States)

    Adler, Camille; Teleki, Alexandra; Kuentz, Martin

    2017-03-09

    The formulation of lipophilic and hydrophobic compounds is a challenge for the pharmaceutical industry and it requires the development of complex formulations. Our first aim was to investigate hot-melt extrudate microstructures by means of multifractal analysis using scanning electron microscopy imaging. Since the microstructure can affect solid dosage form performance such as mechanical properties, a second objective was to study the influence of the type of adsorbent and of the presence of an amorphous compound on extrudate hardness. β-Carotene (BC) was chosen as poorly water-soluble model compound. Formulations containing a polymer, a lipid and two different silica based inorganic carriers were produced by hot-melt extrusion. Based on scanning electron microscopy/energy dispersive X-ray spectroscopy, the obtained images were analyzed using multifractal formalism. The breaking force of the strands was assessed by a three point bending test. Multifractal analysis and three point bending results showed that the nature of interparticle interactions in the inorganic carrier as well as the presence of amorphous BC had an influence on the microstructure and thus on the mechanical performance. The use of multifractal analysis and the study of the mechanical properties were complementary to better characterize and understand complex formulations obtained by hot-melt extrusion.

  13. Clinical feasibility of 3D automated coronary atherosclerotic plaque quantification algorithm on coronary computed tomography angiography: Comparison with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung-Bok [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Myongji Hospital, Division of Cardiology, Cardiovascular Center, Goyang (Korea, Republic of); Lee, Byoung Kwon [Yonsei University College of Medicine, Division of Cardiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Shin, Sanghoon [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); National Health Insurance Corporation Ilsan Hospital, Division of Cardiology, Goyang (Korea, Republic of); Heo, Ran; Chang, Hyuk-Jae; Chung, Namsik [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of); Arsanjani, Reza [Cedars-Sinai Medical Center, Departments of Imaging and Medicine, Cedars-Sinai Heart Institute, Los Angeles, CA (United States); Kitslaar, Pieter H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical Imaging Systems B.V., Leiden (Netherlands); Broersen, Alexander; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Ahn, Sung Gyun [Yonsei University Wonju Severance Christian Hospital, Division of Cardiology, Wonju (Korea, Republic of); Min, James K. [New York-Presbyterian Hospital, Institute for Cardiovascular Imaging, Weill-Cornell Medical College, New York, NY (United States); Hong, Myeong-Ki; Jang, Yangsoo [Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of)

    2015-10-15

    To evaluate the diagnostic performance of automated coronary atherosclerotic plaque quantification (QCT) by different users (expert/non-expert/automatic). One hundred fifty coronary artery segments from 142 patients who underwent coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS) were analyzed. Minimal lumen area (MLA), maximal lumen area stenosis percentage (%AS), mean plaque burden percentage (%PB), and plaque volume were measured semi-automatically by expert, non-expert, and fully automatic QCT analyses, and then compared to IVUS. Between IVUS and expert QCT analysis, the correlation coefficients (r) for the MLA, %AS, %PB, and plaque volume were excellent: 0.89 (p < 0.001), 0.84 (p < 0.001), 0.91 (p < 0.001), and 0.94 (p < 0.001), respectively. There were no significant differences in the mean parameters (all p values >0.05) except %AS (p = 0.01). The automatic QCT analysis showed comparable performance to non-expert QCT analysis, showing correlation coefficients (r) of the MLA (0.80 vs. 0.82), %AS (0.82 vs. 0.80), %PB (0.84 vs. 0.73), and plaque volume (0.84 vs. 0.79) when they were compared to IVUS, respectively. Fully automatic QCT analysis showed clinical utility compared with IVUS, as well as a compelling performance when compared with semiautomatic analyses. (orig.)

  14. Low gray scale values of computerized images of carotid plaques associated with increased levels of triglyceride-rich lipoproteins and with increased plaque lipid content

    DEFF Research Database (Denmark)

    Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Weibe, Britt M.

    1997-01-01

    Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content......Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content...

  15. A Computational Model to Assess Poststenting Wall Stresses Dependence on Plaque Structure and Stenosis Severity in Coronary Artery

    Directory of Open Access Journals (Sweden)

    Zuned Hajiali

    2014-01-01

    Full Text Available The current study presents computational models to investigate the poststenting hemodynamic stresses and internal stresses over/within the diseased walls of coronary arteries which are in different states of atherosclerotic plaque. The finite element method is applied to build the axisymmetric models which include the plaque, arterial wall, and stent struts. The study takes into account the mechanical effects of the opening pressure and its association with the plaque severity and the morphology. The wall shear stresses and the von Mises stresses within the stented coronary arteries show their strong dependence on the plaque structure, particularly the fibrous cap thickness. Higher stresses occur in severely stenosed coronaries with a thinner fibrous cap. Large stress concentrations around the stent struts cause injury or damage to the vessel wall which is linked to the mechanism of restenosis. The in-stent restenosis rate is also highly dependent on the opening pressure, to the extent that stenosed artery is expanded, and geometry of the stent struts. The present study demonstrates, for the first time, that the restenosis is to be viewed as a consequence of biomechanical design of a stent repeating unit, the opening pressure, and the severity and morphology of the plaque.

  16. Detection of vulnerable plaques rather than the culprit lesions in patients with acute coronary syndrome using virtual histology intravascular ultrasound imaging

    Institute of Scientific and Technical Information of China (English)

    QIAN Ju-ying

    2009-01-01

    @@ Pathology and postmortem studies have reported that the most important mechanism of acute coronary syndrome (ACS) is the rupture of a vulnerable plaque and subsequent thrombus formation. Such events commonly arise from the non-flow limiting atherosclerotic lesions which are prone to rupture. Thin-cap fibroatheromas (TCFA) are the most common type of vulnerable plaque. As the widely used technique for the detection of coronary arterial diseases, coronary angiography has intrinsic limitations since it only portrays the contrast agent-filled contour of the lumen and provides little information on the vessel wall and even less the characteristics of the plaques.

  17. Lack of autologous tissue transmission of eosinophilic plaques in cats.

    Science.gov (United States)

    Moriello, K A; Kunkle, G; Miller, L M; Crowley, A

    1990-07-01

    Autologous tissue transmission of spontaneously developing feline eosinophilic plaques was attempted in 5 cats. Macerated tissue from the plaque was vigorously rubbed onto 2 scarified skin sites in each cat. The inoculated areas were observed daily for 30 days. During that time, no clinical or histologic evidence of transmission was found.

  18. Carotid plaque, intima-media thickness, and incident aortic stenosis

    DEFF Research Database (Denmark)

    Martinsson, Andreas; Östling, Gerd; Persson, Margaretha

    2014-01-01

    OBJECTIVE: Aortic stenosis (AS) shares risk factors with atherosclerotic vascular disease. Carotid intima-media thickness (IMT) and plaque may reflect the cumulative damage from exposure to different atherosclerotic risk factors. We examined the relationship of carotid IMT and plaque with incident...

  19. Het effect van suikervrije (functionele) kauwgom op plaque en gingivitis

    NARCIS (Netherlands)

    Keukenmeester, R.S.; Slot, D.E.; van der Weijden, G.A.

    2013-01-01

    Het doel van twee systematische literatuuronderzoeken was het onderzoeken van het effect van suikervrije (functionele) kauwgom op plaque en klinische parameters van gingivitis. Studie 1 onderzocht het effect op plaque en gingivitis van suikervrije kauwgom ten opzichte van geen kauwgomgebruik. Studie

  20. Red fluorescent dental plaque: An indicator of oral disease?

    NARCIS (Netherlands)

    Volgenant, C.M.C.

    2016-01-01

    Oral diseases are worldwide the most common diseases, with dental caries and periodontal inflammatory diseases as most frequently occurring diseases. Both are strongly associated with dental plaque, which is the mass of bacteria (biofilm) that grows on surfaces in the mouth. Some dental plaque fluor

  1. Plaque removal by young children using old and new toothbrushes.

    NARCIS (Netherlands)

    Palenstein Helderman, W.H. van; Kyaing, M.M.; Aung, M.T.; Soe, W.; Rosema, N.A.; Weijden, G.A. van der; Hof, M.A. van 't

    2006-01-01

    There is inconclusive evidence about the relationship between toothbrush wear and plaque removal. This randomized cross-over clinical trial aimed to validate or invalidate non-inferiority in the plaque-removal efficacy of old vs. new toothbrushes in the hands of 7- and 8-year-old children. The lower

  2. The use of imbricated sutures in radioactive plaque brachytherapy surgery

    Directory of Open Access Journals (Sweden)

    Kaan Gündüz

    2010-03-01

    Full Text Available Kaan Gündüz1, Jose S Pulido1, Peter D Yeakel2, Michael King3, Kelly L Classic1, Keith M Furutani21Department of Ophthalmology, 2Department of Radiation Oncology, 3Section of Media Support Services, Mayo Clinic, Rochester, MN, USAAbstract: This paper describes a new technique to suture the radioactive plaque to sclera. The radioactive plaque is conventionally sutured to the sclera using 5/0 nylon sutures. The imbricated suture technique involves using a 1/0 silk or 2/0 mersilene suture imbricated with the 5/0 nylon suture when the nylon suture is tied and cut. The imbricated suture technique allows easy identification of the plaque at removal and provides a surface that separates the 5/0 nylon from the surface of the eyelet platform, making suture cutting easier and safer. The radiation exposure times ranged from 9.1 minutes to 14 minutes (mean: 10.8 minutes during plaque insertion and from 2.8 to 3.3 minutes (mean: 3.0 minutes during plaque removal with the imbricated suture technique. This technique may decrease radiation exposure time and may prevent inadvertent scleral damage.Keywords: plaque radiotherapy, Iodine-125, Ruthenium-106, Collaborative Ocular Melanoma Study, choroidal melanoma, ciliary body melanoma, retinoblastoma, plaque placement, plaque removal, radiation exposure

  3. New low-viscosity overlay medium for viral plaque assays

    Directory of Open Access Journals (Sweden)

    Garten Wolfgang

    2006-08-01

    Full Text Available Abstract Background Plaque assays in cell culture monolayers under solid or semisolid overlay media are commonly used for quantification of viruses and antiviral substances. To overcome the pitfalls of known overlays, we tested suspensions of microcrystalline cellulose Avicel RC/CL™ as overlay media in the plaque and plaque-inhibition assay of influenza viruses. Results Significantly larger plaques were formed under Avicel-containing media, as compared to agar and methylcellulose (MC overlay media. The plaque size increased with decreasing Avicel concentration, but even very diluted Avicel overlays (0.3% ensured formation of localized plaques. Due to their low viscosity, Avicel overlays were easier to use than methylcellulose overlays, especially in the 96-well culture plates. Furthermore, Avicel overlay could be applied without prior removal of the virus inoculum thus facilitating the assay and reducing chances of cross-contamination. Using neuraminidase inhibitor oseltamivir carboxylate, we demonstrated applicability of the Avicel-based plaque reduction assay for testing of antiviral substances. Conclusion Plaque assay under Avicel-containing overlay media is easier, faster and more sensitive than assays under agar- and methylcellulose overlays. The assay can be readily performed in a 96-well plate format and seems particularly suitable for high-throughput virus titrations, serological studies and experiments on viral drug sensitivity. It may also facilitate work with highly pathogenic agents performed under hampered conditions of bio-safety labs.

  4. [Effect of Root Iron Plaque on Norfloxacin Uptake by Rice].

    Science.gov (United States)

    Ma, Wei; Bao, Yan-yu

    2015-06-01

    In anaerobic condition, release of oxygen by roots to rhyzosphere caused the formation of red plaque of iron oxides or hydroxides on the root surface of rice. The effect of iron plaque on norfloxacin uptake was investigated with solution culture in greenhouse, and the results are showed in the following. The content of iron plaque increased with the increase of Fe2+ concentration in medium. After the addition of norfloxacin in nutrient solution, the content of iron plaques on the root surface decreased to different degree, and the reduction of iron plaques was increasing with the increase of norfloxacin mass concentration. Significant relationships were found between the iron plaques and norfloxacin on the root surface, and the correlation coefficients were 0.959 (norfloxacin mass concentration was 10 mg x L(-1)) and 0.987 (norfloxacin mass concentration was 50 mg x L(-1)), respectively, however, the norfloxacin contents in roots and shoots had no significant correlation with the iron plaques. After addition of different mass concentrations of norfloxacin, the quality distribution percentages of norfloxacin on the root surface and in roots and shoots were 87.7%-97.6%, 0.8%-4.8%, 1.5%-7.5%, respectively, the norfloxacin content on the root surface was far greater than those in roots and shoots. It was therefore concluded that iron plaque on roots was a norfloxacin reservoir for rice plant but had no significant effect on the transfer of norfloxacin to roots and shoots of the rice plant.

  5. Iron plaque formed under aerobic conditions efficiently immobilizes arsenic in Lupinus albus L roots.

    Science.gov (United States)

    Fresno, Teresa; Peñalosa, Jesús M; Santner, Jakob; Puschenreiter, Markus; Prohaska, Thomas; Moreno-Jiménez, Eduardo

    2016-09-01

    Arsenic is a non-threshold carcinogenic metalloid. Thus, human exposure should be minimised, e.g. by chemically stabilizing As in soil. Since iron is a potential As immobiliser, it was investigated whether root iron plaque, formed under aerobic conditions, affects As uptake, metabolism and distribution in Lupinus albus plants. White lupin plants were cultivated in a continuously aerated hydroponic culture containing Fe/EDDHA or FeSO4 and exposed to arsenate (5 or 20 μM). Only FeSO4 induced surficial iron plaque in roots. LA-ICP-MS analysis accomplished on root sections corroborated the association of As to this surficial Fe. Additionally, As(V) was the predominant species in FeSO4-treated roots, suggesting less efficient As uptake in the presence of iron plaque. Fe/EDDHA-exposed roots neither showed such surficial FeAs co-localisation nor As(V) accumulation; in contrast As(III) was the predominant species in root tissue. Furthermore, FeSO4-treated plants showed reduced shoot-to-root As ratios, which were >10-fold lower compared to Fe/EDDHA treatment. Our results highlight the role of an iron plaque formed in roots of white lupin under aerobic conditions on As immobilisation. These findings, to our knowledge, have not been addressed before for this plant and have potential implications on soil remediation (phytostabilisation) and food security (minimising As in crops).

  6. Asbestos exposure, pleural plaques, and the risk of death from lung cancer.

    Science.gov (United States)

    Pairon, Jean-Claude; Andujar, Pascal; Rinaldo, Mickael; Ameille, Jacques; Brochard, Patrick; Chamming's, Soizick; Clin, Bénédicte; Ferretti, Gilbert; Gislard, Antoine; Laurent, François; Luc, Amandine; Wild, Pascal; Paris, Christophe

    2014-12-15

    Although asbestos is a well-known lung carcinogen, the pleural plaque-lung cancer link remains controversial. This study was designed to examine this link in asbestos-exposed workers. A 6-year follow-up was conducted to study lung cancer mortality in the 5,402 male subjects participating in an asbestos-related disease screening program conducted from October 2003 to December 2005 in four French regions. Chest computed tomography (CT) scan was performed in all subjects with randomized, independent, double reading of CT scans focusing on benign asbestos-related abnormalities. Cox model survival regression analysis was used to model lung cancer mortality according to the presence of pleural plaques, with age as the main time variable, adjusting for smoking and asbestos cumulative exposure index. All statistical tests were two-sided. Thirty-six deaths from lung cancer were recorded. Lung cancer mortality was significantly associated with pleural plaques in the follow-up study in terms of both the unadjusted hazard ratio of 2.91 (95% confidence interval = 1.49-5.70) and the adjusted hazard ratio of 2.41 (95% confidence interval = 1.21-4.85) after adjustment for smoking and asbestos cumulative exposure index. Pleural plaques may be an independent risk factor for lung cancer death in asbestos-exposed workers and could be used as an additional criterion in the definition of high-risk populations eligible for CT screening.

  7. Molecular detection and corelation of Helicobacter pylori in dental plaque and gastric biopsies of dyspeptic patients

    Science.gov (United States)

    Bharath, T Sreenivasa; Reddy, M Sesha; Dhanapal, Raghu; Raj Kumar, N Govind; Neeladri Raju, PV; Saraswathi, TR

    2014-01-01

    Helicobacter pylori is a microaerophilic organism, which colonizes in the gastric mucosa. Its role in etiology and development of acute and chronic gastritis and peptic ulcer diseases is scientifically proved. Oral cavity especially supragingival, subgingival plaque and so forth simulate the same microaerophilic environment favorable for the growth of this bacterium. Aim: Detection of H. pylori simultaneously in the oral cavity and gastric mucosa of patients suffering from gastric pathologies. Objectives: To detect H. pylori in the oral cavity and gastric mucosa using endoscopy, urease test and real-time polymerase chain reaction (PCR) (urease A gene). Determining its association and corelation with patient demographics, oral hygiene maintenance and periodontal disease status. Materials and Methods: Endoscopic examination, oral findings oral hygiene index-simplified (OHI-S) and community periodontal index and treatment needs (CPITN) indices were recorded. Antral biopsies and supragingival plaque samples were taken from 56 dyspeptic adult patients. The collected samples were subjected to histological examination, urease broth test and urease A gene amplification using real-time PCR. Result: H. pylori was detected in the supragingival plaque of individuals with H. pylori-induced gastric diseases using rapid urease test and real-time PCR analysis. Occurrence of same strain of H. pylori simultaneously in plaque and gastric mucosa was observed. Positive correlation was obtained between the collected indices and quantity of H. pylori colonization. PMID:24959032

  8. Detection of Fungal Elements in Atherosclerotic Plaques Using Mycological, Pathological and Molecular Methods

    Directory of Open Access Journals (Sweden)

    Omid MASOUMI

    2015-10-01

    Full Text Available Background: The aim of this study was to detect fungi in atherosclerotic plaques and investigate their possible role in atherosclerosis.Methods: Coronary atherosclerotic plaques specimen were obtained from patients with atherosclerosis. Direct exami-nation, culture, histopathology study, PCR and sequencing were performed to detect/identify the mycotic elements in the plaques. Age, sex, smoking, obesity, hypertension, hyperlipidemia, family history of heart diseases and diabetes were considered and data were analyzed using Chi Square test by SPSS version 15.Results: A total of 41 specimens were analyzed. Direct examination for fungal elements was negative in all cases but in culture only one specimen grew as a mold colony. The presence of fungal elements were confirmed in 6 and 2 tissue sections stained by Gomori methenamine silver and Hematoxylin and Eosin methods, respectively. Using PCR, 11 cases were positive for fungi. The DNA sequence analysis of six positive specimens which were randomly selected revealed fungi as Candida albicans (n=3, Candida guilliermondii (n=2 and Monilia sp. (n=1.Conclusion: A significant association between the presence of fungi in atherosclerotic plaques and severity of athero-genesis and atherosclerotic disease was not found. This could be due to limited numbers of patients included in our study. However, the presence of fungal elements in 26.8% of our specimens is considerable and the results does not exclude the correlation between the presence of fungi with atherosclerosis and coronary artery disease.

  9. Molecular detection and corelation of Helicobacter pylori in dental plaque and gastric biopsies of dyspeptic patients

    Directory of Open Access Journals (Sweden)

    T Sreenivasa Bharath

    2014-01-01

    Full Text Available Helicobacter pylori is a microaerophilic organism, which colonizes in the gastric mucosa. Its role in etiology and development of acute and chronic gastritis and peptic ulcer diseases is scientifically proved. Oral cavity especially supragingival, subgingival plaque and so forth simulate the same microaerophilic environment favorable for the growth of this bacterium. Aim: Detection of H. pylori simultaneously in the oral cavity and gastric mucosa of patients suffering from gastric pathologies. Objectives: To detect H. pylori in the oral cavity and gastric mucosa using endoscopy, urease test and real-time polymerase chain reaction (PCR (urease A gene. Determining its association and corelation with patient demographics, oral hygiene maintenance and periodontal disease status. Materials and Methods: Endoscopic examination, oral findings oral hygiene index-simplified (OHI-S and community periodontal index and treatment needs (CPITN indices were recorded. Antral biopsies and supragingival plaque samples were taken from 56 dyspeptic adult patients. The collected samples were subjected to histological examination, urease broth test and urease A gene amplification using real-time PCR. Result: H. pylori was detected in the supragingival plaque of individuals with H. pylori-induced gastric diseases using rapid urease test and real-time PCR analysis. Occurrence of same strain of H. pylori simultaneously in plaque and gastric mucosa was observed. Positive correlation was obtained between the collected indices and quantity of H. pylori colonization.

  10. Association Between Absolute Eosinophil Count and Complex Aortic Arch Plaque in Patients With Acute Ischemic Stroke.

    Science.gov (United States)

    Kitano, Takaya; Nezu, Tomohisa; Shiromoto, Takashi; Kubo, Satoshi; Uemura, Jyunichi; Wada, Yuko; Yagita, Yoshiki

    2017-04-01

    Eosinophil counts are thought to be associated with atherosclerosis and aortic arch plaques. However, whether these associations exist among patients with acute ischemic stroke remains unclear. We aimed to evaluate the association between absolute eosinophil count (AEC) and aortic arch plaques among these patients. Consecutive acute ischemic stroke patients undergoing transesophageal echocardiography were retrospectively analyzed. Complex aortic arch plaques (CAPs) were defined as plaques ≥4 mm in thickness, with ulcer, or with mobile component. A total of 430 patients (289 male, mean age 69.8±11.4 years) were enrolled. Patients with CAPs (n=169) showed higher mean AEC than those without (167±174/µL versus 127±127/µL; P=0.007). Multivariate analysis showed that increased AEC was independently associated with the presence of CAPs (odds ratio, 2.09; 95% confidence interval, 1.21-3.65). Among patients with acute ischemic stroke, increased AEC was independently associated with the presence of CAPs. Our results suggest that AEC may be a useful predictor for the presence of CAPs in these patients. © 2017 American Heart Association, Inc.

  11. Towards the mechanical characterization of abdominal wall by inverse analysis.

    Science.gov (United States)

    Simón-Allué, R; Calvo, B; Oberai, A A; Barbone, P E

    2017-02-01

    The aim of this study is to characterize the passive mechanical behaviour of abdominal wall in vivo in an animal model using only external cameras and numerical analysis. The main objective lies in defining a methodology that provides in vivo information of a specific patient without altering mechanical properties. It is demonstrated in the mechanical study of abdomen for hernia purposes. Mechanical tests consisted on pneumoperitoneum tests performed on New Zealand rabbits, where inner pressure was varied from 0mmHg to 12mmHg. Changes in the external abdominal surface were recorded and several points were tracked. Based on their coordinates we reconstructed a 3D finite element model of the abdominal wall, considering an incompressible hyperelastic material model defined by two parameters. The spatial distributions of these parameters (shear modulus and non linear parameter) were calculated by inverse analysis, using two different types of regularization: Total Variation Diminishing (TVD) and Tikhonov (H(1)). After solving the inverse problem, the distribution of the material parameters were obtained along the abdominal surface. Accuracy of the results was evaluated for the last level of pressure. Results revealed a higher value of the shear modulus in a wide stripe along the craneo-caudal direction, associated with the presence of linea alba in conjunction with fascias and rectus abdominis. Non linear parameter distribution was smoother and the location of higher values varied with the regularization type. Both regularizations proved to yield in an accurate predicted displacement field, but H(1) obtained a smoother material parameter distribution while TVD included some discontinuities. The methodology here presented was able to characterize in vivo the passive non linear mechanical response of the abdominal wall. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Genetic divergence of Chikungunya virus plaque variants from the Comoros Island (2005).

    Science.gov (United States)

    Wasonga, Caroline; Inoue, Shingo; Rumberia, Cecilia; Michuki, George; Kimotho, James; Ongus, Juliette R; Sang, Rosemary; Musila, Lillian

    2015-12-01

    Chikungunya virus (CHIKV) from a human sample collected during the 2005 Chikungunya outbreak in the Comoros Island, showed distinct and reproducible large (L2) and small (S7) plaques which were characterized in this study. The parent strain and plaque variants were analysed by in vitro growth kinetics in different cell lines and their genetic similarity assessed by whole genome sequencing, comparative sequence alignment and phylogenetic analysis. In vitro growth kinetic assays showed similar growth patterns of both plaque variants in Vero cells but higher viral titres of S7 compared to L2 in C6/36 cells. Amino acids (AA) alignments of the CHIKV plaque variants and S27 African prototype strain, showed 30 AA changes in the non-structural proteins (nsP) and 22 AA changes in the structural proteins. Between L2 and S7, only two AAs differences were observed. A missense substitution (C642Y) of L2 in the nsP2, involving a conservative AA substitution and a nonsense substitution (R524X) of S7 in the nsP3, which has been shown to enhance O'nyong-nyong virus infectivity and dissemination in Anopheles mosquitoes. The phenotypic difference observed in plaque size could be attributed to one of these AA substitutions. Phylogenetic analysis showed that the parent strain and its variants clustered closely together with each other and with Indian Ocean CHIKV strains indicating circulation of isolates with close evolutionary relatedness in the same outbreak. These observations pave way for important functional studies to understand the significance of the identified genetic changes in virulence and viral transmission in mosquito and mammalian hosts.

  13. Association of circulating omentin-1 level with arterial stiffness and carotid plaque in type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Yoo Hye

    2011-11-01

    Full Text Available Abstract Background Adipokines contribute directly to the atherosclerotic process, connecting metabolic disorders such as obesity and diabetes to cardiovascular disease. Omentin-1 is a recently discovered novel adipokine, so data about the relationship of this adipokine to vascular health in type 2 diabetes is limited. Methods We enrolled 60 people with type 2 diabetes, with or without carotid plaque, and 30 participants with normal glucose tolerance. We measured serum omentin-1, high-sensitivity C-reactive protein (hsCRP levels, and the homeostasis model assessment of insulin resistance (HOMA-IR, as well as other cardiovascular risk factors. Vascular health was assessed by brachial ankle pulse wave velocity (baPWV and carotid intima-media thickness (IMT. Results Serum omentin-1 levels were significantly decreased in type 2 diabetes patients compared to normal glucose controls and was further reduced in type 2 diabetes patients with carotid plaque compared to those without carotid plaque. Multiple stepwise regression analysis showed that age, systolic blood pressure, history of use of statins, angiotensin receptor blockers or angiotensin-converting enzyme inhibitors, and serum omentin-1 level were independent factors determining baPWV in people with type 2 diabetes (r2 = 0.637. Furthermore, in multivariate logistic regression analysis, circulating omentin-1 level was an independent decisive factor for the presence of carotid plaque in type 2 diabetes patients, even after adjusting for age, gender, body mass index, systolic blood pressure, fasting blood glucose, low density lipoprotein cholesterol, and history of smoking and medication (odds ratio, 0.621; 95% confidence interval, 0.420-0.919; P = 0.017. Conclusions Circulating omentin-1 level was independently correlated with arterial stiffness and carotid plaque in type 2 diabetes, even after adjusting for other cardiovascular risk factors and detailed medication history.

  14. Spectroscopy to improve identification of vulnerable plaques in cardiovascular disease.

    Science.gov (United States)

    Bruggink, Janneke L M; Meerwaldt, Robbert; van Dam, Gooitzen M; Lefrandt, Joop D; Slart, Riemer H J A; Tio, René A; Smit, Andries J; Zeebregts, Clark J

    2010-01-01

    Many apparent healthy persons die from cardiovascular disease, despite major advances in prevention and treatment of cardiovascular disease. Traditional cardiovascular risk factors are able to predict cardiovascular events in the long run, but fail to assess current disease activity or nearby cardiovascular events. There is a clear relation between the occurrence of cardiovascular events and the presence of so-called vulnerable plaques. These vulnerable plaques are characterized by active inflammation, a thin cap and a large lipid pool. Spectroscopy is an optical imaging technique which depicts the interaction between light and tissues, and thereby shows the biochemical composition of tissues. In recent years, impressive advances have been made in spectroscopy technology and intravascular spectroscopy is able to assess the composition of plaques of interest and thereby to identify and actually quantify plaque vulnerability. This review summarizes the current evidence for spectroscopy as a measure of plaque vulnerability and discusses the potential role of intravascular spectroscopic imaging techniques.

  15. Anti-plaque agents. Rationale and prospects for prevention of gingivitis and periodontal disease.

    Science.gov (United States)

    van der Ouderaa, F J

    1991-07-01

    Oral health surveys have shown that even in countries with established patterns of oral hygiene habits, most individuals have relatively poor gingival health. This is due to a low interest in complying with oral health procedures. A number of factors are apparent when investigating compliance to oral hygiene habits, viz only approximately 50% of the population brushes twice a day or more, brushing time is probably much too short and use of dental floss is not very prevalent. Studies of the effect of motivation on oral hygiene suggest that improvements can be achieved, but these are not maintained unless motivation is continuously reinforced. This suggests that topically applied anti-plaque agents should be used to augment mechanical plaque control. A number of product forms are available to delivery anti-plaque agents i.e., mouthrinses, dentifrices, aqueous gels, and additionally floss, chewing gum and lozenges. Any product form should provide a physically, chemically and microbiologically stable environment for the agent concerned. It should facilitate optimal bioavailability of the agents at the site of action and encourage patient compliance. Anti-plaque agents for topical administration should have the following properties: high intrinsic efficacy against a broad spectrum of oral organisms, toxicological and ecological safety, oral substantivity, no adverse reactions and good chemical stability. A number of classes of anti-plaque agents have been identified such as positively charged organic molecules, metal salts, phenols, enzymes, peroxides, sugar substitutes, fluorides and surface modifying agents. In order to achieve optimal bioavailability, the agent to be dosed should be compatible with the product form used. The 2 major product forms are rinses and dentifrices.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Effect of Fluoride Mouthrinse and Toothpaste on Number of Streptococcal Colony Forming Units of Dental Plaque

    Directory of Open Access Journals (Sweden)

    SE Jabbarifar

    2005-11-01

    Full Text Available Background: Frequent topical fluoride therapy through toothpaste, mouthrinse, professional gels and solutions causes decrease in incidence, pause and repair of dental caries in the enamel. These mechanisms are done through penetration of fluoride ions (F- and their replacement with hydroxyl ions (OH- of hydroxyappatite of enamel, interfere with microbial metabolism of dental plaque and bacteriostatic effect on some cariogenic bacterial strains such as streptococci. The aim of this study was to examine the effect of fluoride mouthrinse and toothpaste on the number of streptococcal colony forming units of dental plaque. Methods: 62 children with 6-7 years old were put in two groups. Samples of dental plaque from each group were collected both before and after use of the fluoride mouthrinse and or toothpaste. The samples were cultured on blood agar to find the number of streptococcal colony forming units (CFU. The mean colony forming unit was compared inter and intra groups before and after application of Fluoride products. Results: The streptococcal CFU of dental plaque before and after use of the mouthrinse and toothpaste respectively was (1240±1367, 1253±1341.5 and (551±716, 898±1151. Statistically, the streptococcal CFU in each group before and after use of the toothpaste and mouthrinse was significantly different. Conclusion: The findings of this study indicated that the fluoride toothpaste and mouthrinse reduce number of streptococcal colony forming units of dental plaque. Also this reduction was not depended on level of (F- Ions, sort of vehicle of fluoride and frequent application of the fluoride mouthrinse and toothpaste. Keywords: fluoride mouthrinse, fluoride toothpaste, colony forming unit (CFU, streptococcus

  17. Isogeometric Analysis and Shape Optimization in Fluid Mechanics

    DEFF Research Database (Denmark)

    Nielsen, Peter Nørtoft

    unites the power to solve complex engineering problems from finite element analysis (FEA) with the ability to effectively represent complex shapes from computer aided design (CAD). The methodology is appealing for flow modeling purposes also due to the inherent high regularity of velocity and pressure......This thesis brings together the fields of fluid mechanics, as the study of fluids and flows, isogeometric analysis, as a numerical method to solve engineering problems using computers, and shape optimization, as the art of finding "best" shapes of objects based on some notion of goodness. The flow...... is given of how isogeometric analysis is applied to flow problems. We present several new discretizations of the velocity and pressure spaces, we investigate these in terms of stability and error convergence properties, and a benchmark flow problem is analyzed. As the second contribution, we show how...

  18. Hyperostotic sphenoid wing meningioma en plaque: proptosis management

    Directory of Open Access Journals (Sweden)

    Zakaria Wael K.

    2016-12-01

    Full Text Available Background: En plaque sphenoid wing meningioma is morphological unique in comparison with other intracranial meningiomas, characterized by a carpet-like usually small soft tissue component which invade the dura and extensively involve the bone specially the sphenoid wing and orbit causing significant hyperostosis. Patients & Methods: A retrospective analysis of the clinical data, neuro-radiological features, and operative techniques of eighteen patients underwent transcranio-orbital approach sphenoid wing meningioma presented with proptosis during the period from September 2011 to April 2014 in the neurosurgery department, Mansoura University. Patients age ranged from 38 years to 54 years and there was sex males and twelve females. Chief complaints were progressive proptosis and visual acuity deficits. All patients were operated up on using a fronto-temporal approach with orbital decompression. The extent of tumor resection and postoperative complications were investigated. Results: Total removal was achieved in fourteen cases (77.8% over a mean follow-up period of 36 months. Pathological examination showed that twelve patients (66.67% were meningothelial meningiomas. After surgery, proptosis improved in all patients, visual acuity improved in fifteen patients (83.3%. Cerebrospinal fluid leakage was found in one patient. There were no operation-related deaths or other significant complications. Four patients had residual tumor (22.2%; two of them underwent surgical re-attack of the tumor and the other two cases were sent for gamma knife radio-surgery. Conclusions: Sphenoid wing meningioma en plaque, mainly meningothelial meningiomas, are characterized by the associated bony hyperostosis that gives them a distinct radiological appearance. The bony hyperostosis is of neoplastic nature and is responsible for many of the clinical manifestation of such tumors and hence should be totally drilled to achieve cure and avoid recurrence. Extensive tumor

  19. Carotid artery stenosis with a high-intensity signal plaque on time-of-flight magnetic resonance angiography and association with evidence of intraplaque hypoxia.

    Science.gov (United States)

    Ogata, Atsushi; Kawashima, Masatou; Wakamiya, Tomihiro; Nishihara, Masashi; Masuoka, Jun; Nakahara, Yukiko; Ebashi, Ryo; Inoue, Kohei; Takase, Yukinori; Irie, Hiroyuki; Abe, Tatsuya

    2017-06-01

    OBJECTIVE Hypoxia induces angiogenesis and plays a major role in the progression of carotid plaques. During carotid intervention, plaques with high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) often cause ischemic stroke and embolic complications. However, the role of intraplaque hypoxia before carotid endarterectomy (CEA) and carotid artery stenting is not presently understood. In this study the authors aimed to investigate the relationship between intraplaque hypoxia and MRA findings. METHODS Nineteen consecutive patients with 20 carotid artery stenoses who underwent CEA at Saga University Hospital between August 2008 and December 2014 were enrolled in the study. The expressions of hypoxia-inducible transcription factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were analyzed by immunohistochemical analysis. In addition, the relationship between the findings on TOF MRA and pathology for the carotid plaques was analyzed. RESULTS High-intensity plaques on TOF MRA showed higher expression levels of HIF-1α (p = 0.015) and VEGF (p = 0.007) compared with isointensity plaques. The rate of intraplaque hemorrhage (IPH) on TOF MRA was also significantly higher in the high-intensity plaques than in the isointensity plaques (p = 0.024). Finally, the mean number of neovessels was significantly higher in those without plaque hemorrhage than in those with plaque hemorrhage (p = 0.010). CONCLUSIONS Plaques with high-intensity signals on TOF MRA were associated with IPH and evidence of intraplaque hypoxia. This fact may represent an opportunity to establish novel therapeutic agents targeting intraplaque hypoxia.

  20. The association of lesion eccentricity with plaque morphology and components in the superficial femoral artery: a high-spatial-resolution, multi-contrast weighted CMR study

    Directory of Open Access Journals (Sweden)

    Zhao Xihai

    2010-07-01

    Full Text Available Abstract Background Atherosclerotic plaque morphology and components are predictors of subsequent cardiovascular events. However, associations of plaque eccentricity with plaque morphology and plaque composition are unclear. This study investigated associations of plaque eccentricity with plaque components and morphology in the proximal superficial femoral artery using cardiovascular magnetic resonance (CMR. Methods Twenty-eight subjects with an ankle-brachial index less than 1.00 were examined with 1.5T high-spatial-resolution, multi-contrast weighted CMR. One hundred and eighty diseased locations of the proximal superficial femoral artery (about 40 mm were analyzed. The eccentric lesion was defined as [(Maximum wall thickness- Minimum wall thickness/Maximum wall thickness] ≥ 0.5. The arterial morphology and plaque components were measured using semi-automatic image analysis software. Results One hundred and fifteen locations were identified as eccentric lesions and sixty-five as concentric lesions. The eccentric lesions had larger wall but similar lumen areas, larger mean and maximum wall thicknesses, and more calcification and lipid rich necrotic core, compared to concentric lesions. For lesions with the same lumen area, the degree of eccentricity was associated with an increased wall area. Eccentricity (dichotomous as eccentric or concentric was independently correlated with the prevalence of calcification (odds ratio 3.78, 95% CI 1.47-9.70 after adjustment for atherosclerotic risk factors and wall area. Conclusions Plaque eccentricity is associated with preserved lumen size and advanced plaque features such as larger plaque burden, more lipid content, and increased calcification in the superficial femoral artery.

  1. Plaque Formation by and Plaque Cloning of Chlamydia trachomatis Biovar Trachoma

    OpenAIRE

    Matsumoto, Akira; Izutsu, Hiroshi; Miyashita, Naoyuki; Ohuchi, Masanobu

    1998-01-01

    A new technique for the induction of plaque formation by Chlamydia trachomatis biovar trachoma applicable to the titration of infectivity and cloning of biovar trachoma was established. Three novel strains were cloned and confirmed to be free of glycogen inclusions. The lack of glycogen accumulation correlated with the absence of a 7.5-kb plasmid, which is highly conserved in other strains of C. trachomatis. Although the growth efficiency of these plasmid-free strains was slightly lower than ...

  2. Dynamic mechanical analysis of double base rocket propellants

    Directory of Open Access Journals (Sweden)

    Marcin Cegła

    2016-03-01

    Full Text Available The article presents dynamic mechanical analysis (DMA for solid rocket propellants testing. Principles of operation and measured values are briefly described. The authors refer to the previous research of PTFE material and literature data providing information about proper experimental conditions and influence of measurement frequency, load amplitude, and heating rate on the results of DMA tests. The experimental results of solid double-base rocket propellant testing obtained on the N Netzsch DMA 242 device are presented. Mechanical properties such as the dynamic storage modulus E´, the dynamic loss modulus E˝ and tan(δ were measured within temperature range from (–120°C to (+90°C at the heating rate of 1 K/min. The test sample was subjected to a dual cantilever multi-frequency test. Special attention was paid to determination of the glass transition temperature of the tested propellant in reference to the NATO standardization agreement 4540 as well as influence of the measurement frequency on the glass transition.[b]Keywords[/b]: Dynamic mechanical analysis, solid rocket propellants, glass transition temperature

  3. Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation

    National Research Council Canada - National Science Library

    Zimmermann, Leonard W; Amoush, Ahmad; Wilkinson, Douglas A

    2015-01-01

    ... for an Eye Physics model EP917 eye plaque. Monte Carlo (MC) simulation using MCNPX 2.7 was used to calculate the central axis dose in water for an EP917 eye plaque fully loaded with 17 IsoAid Advantage (125)I seeds...

  4. Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation

    National Research Council Canada - National Science Library

    Zimmermann, Leonard W; Amoush, Ahmad; Wilkinson, Douglas A

    2015-01-01

    ... for an Eye Physics model EP917 eye plaque. Monte Carlo (MC) simulation using MCNPX 2.7 was used to calculate the central axis dose in water for an EP917 eye plaque fully loaded with 17 IsoAid Advantage   125 I seeds...

  5. Circulating Leukocyte and Carotid Atherosclerotic Plaque Telomere Length Interrelation, Association With Plaque Characteristics, and Restenosis After Endarterectomy

    NARCIS (Netherlands)

    Huzen, Jardi; Peeters, Wouter; de Boer, Rudolf A.; Moll, Frans L.; Wong, Liza S. M.; Codd, Veryan; de Kleijn, Dominique P. V.; de Smet, Bart J. G. L.; van Veldhuisen, Dirk J.; Samani, Nilesh J.; van Gilst, Wiek H.; Pasterkamp, Gerard; van der Harst, Pim

    2011-01-01

    Objective-Shorter leukocyte telomeres are associated with atherosclerosis and predict future heart disease. The goal of the present study was to determine whether leukocyte telomere length is related to atherosclerotic plaque telomere length and whether it is associated with plaque characteristics o

  6. The plaque inhibitory effect of a CPC mouthrinse in a 3-day plaque accumulation model - a cross-over study

    NARCIS (Netherlands)

    Versteeg, P.A.; Rosema, N.A.M.; Hoenderdos, N.L.; Slot, D.E.; van der Weijden, G.A.

    2010-01-01

    Objective:  To test the plaque inhibitory effect of an experimental 0.07% cetylpyridinium chloride (CPC) mouthrinse in a 3-day plaque accumulation model in a cross-over design. Material and Methods:  A total of 30 subjects (non-dental students), ≥18 years of age, were randomly assigned to use one of

  7. The content of copper and zinc in human ulcered atherosclerotic plaque

    Directory of Open Access Journals (Sweden)

    Radak Đorđe

    2004-01-01

    Full Text Available INTRODUCTION Copper and zinc have significant antiatherogenic effect influencing activity of antioxidant enzyms (giutathion-peroxidase i superoxid-dismutase, mechanism of apoptosis and other mechanisms. Few studies showed increased copper and zinc concentration in atherosclerotic plaque in comparison to normal vascular tissue. AIM The aim of the study was to compare copper and zinc concentrations in carotid artery tissue without significant atherosclerotic changes and human ulcered atherosclerotic plaque. MATERIAL AND METHODS Study was conducted on 66 patients. Carotid endarterectomy due to the significant carotid atherosclerotic changes with cerebrovascular disorders was performed in 54 patients (81.8%. Control group consisted of 12 patients (18.2% without carotid atherosclerotic changes operated due to the symptomatic kinking and coiling of carotid artery. Operated group consisted of 38 man (62.96% and 16 woman (37.04%. Control group had the same number of patients: six men (50% and six women (50%. Preoperatively, all patients were examined by vascular surgeon, neurologist and cardiologist. Duplex sonografy of carotid and vertebral arteries was performed by Aloca DSD 630 ultrasound with mechanical and linear transducer 7.7 MHz. Indication for surgical treatment was obtained according to non-invasive diagnostic protocol and neurological symptoms. Copper and zinc concentration in human ulcered atherosclerotic plaque and carotid artery segment were estimated by spectophotometry (Varian AA-5. RESULTS Average age of our patients was 59.8±8.1 years. For males average age was 76.1 ±9.8 years. And for females 42.4±5.8 years. In group with carotid endarterectomy female patients were significantly younger than male patients (p<0.01. In group with carotid endarterectomy clinically determined neurological disorders were found in 47 patients (87.03%-35 male (74.47% and 12 female patients (25.53%. Regarding risk factors for cardiovascular diseases, no

  8. Analysis of Mechanical Stresses/Strains in Superconducting Wire

    Science.gov (United States)

    Barry, Matthew; Chen, Jingping; Zhai, Yuhu

    2016-10-01

    The optimization of superconducting magnet performance and development of high-field superconducting magnets will greatly impact the next generation of fusion devices. A successful magnet development, however, relies deeply on the understanding of superconducting materials. Among the numerous factors that impact a superconductor's performance, mechanical stress is the most important because of the extreme operation temperature and large electromagnetic forces. In this study, mechanical theory is used to calculate the stresses/strains in typical superconducting strands, which consist of a stabilizer, a barrier, a matrix and superconducting filaments. Both thermal loads and mechanical loads are included in the analysis to simulate operation conditions. Because this model simulates the typical architecture of major superconducting materials, such as Nb3Sn, MgB2, Bi-2212 etc., it provides a good overall picture for us to understand the behavior of these superconductors in terms of thermal and mechanical loads. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship (SULI) program.

  9. A mechanical analysis of myomere shape in fish.

    Science.gov (United States)

    Van Leeuwen, J L

    1999-12-01

    An architectural analysis is offered of the trunk muscles in fish, which are arranged in a longitudinal series of geometrically complex myomeres. The myomeres are separated by myosepta, collagenous sheets with complex fibre patterns. The muscle fibres in the myomeres are also arranged in complex three-dimensional patterns. Previously, it has been proposed that the muscle fibre arrangement allows for a uniform strain distribution within the muscle. Physical constraints limit the range of shapes that fibre-reinforced materials such as muscles can adopt, irrespective of their genetic profile. The three-dimensional shapes of myosepta are predicted by mechanical modelling from the requirements for mechanical stability and prescribed muscle fibre arrangements. The model can also be used to study the force transmission and likely locations of ligaments and bones in the myosepta. The model shows that the dorsal and ventral fins are located such that unfavourable mechanical interactions with the trunk muscles are avoided. In bony fish, extensive muscular deformations (notably in the region of the horizontal septum) that would not contribute to bending are avoided by the mechanical support of the skin, intramuscular bones and ribs. In sharks, the skin plays a more prominent role in avoiding such deformations because of the absence of bony elements.

  10. Analysis of mechanism of shock bump due to roof fall

    Institute of Scientific and Technical Information of China (English)

    GU Xin-jian; LI Jian-xiong

    2004-01-01

    According to the characteristics of the shock bump due to roof fall, a simple mechanics model has been established by applying the catastrophic theory and the law of energy conservation. The author suggests that the shock bump may be induced by the sudden energy release in the roof falling after underground mineral extractions, and through the systematic analysis of actual examples on site, the empirical formulae for the roof falling and energy release are derived, which would provide a new way for the study of the origin and mechanism of mine tremor due to fallen-in roof structure. It is of a great importance to enrich the shock bump theory and production safety in mine.

  11. Collapse Mechanism Analysis in the Design of Superstructure Vehicle

    Science.gov (United States)

    Mohd Nor, M. K.

    2016-11-01

    The EU directive 2001/85/EC is an official European text which describes the specifications for “single deck class II and III vehicles” required to be approved by the regulation UN/ECE no.66 (R66). To prevent the catastrophic consequences by occupant during an accident, the Malaysian government has reinforced the same regulation upon superstructure construction. This paper discusses collapse mechanism analysis of a superstructure vehicle using a Crash D nonlinear analysis computer program based on this regulation. The analysis starts by hand calculation to define the required energy absorption by the chosen structure. Simple calculations were then performed to define the weakest collapse mechanism after undesirable collapse modes are eliminated. There are few factors highlighted in this work to pass the regulation. Using the selected cross section, Crash D simulation showed a good result. Generally, the deformation is linearly correlates to the energy absorption for the structure with low stiffness. Failure of critical members such as vertical lower side wall must be avoided to sustain safety of the passenger compartment and prevent from severe and fatal injuries to the trapped occupant.

  12. Nonlinear analysis of collapse mechanism in superstructure vehicle

    Science.gov (United States)

    Nor, M. K. Mohd; Ho, C. S.; Ma'at, N.

    2017-04-01

    The EU directive 2001/85/EC is an official European text which describes the specifications for "single deck class II and III vehicles" required to be approved by the regulation UN/ECE no.66 (R66). To prevent the catastrophic consequences by occupant during an accident, the Malaysian government has reinforced the same regulation upon superstructure construction. This paper discusses collapse mechanism analysis of a superstructure vehicle using a Crash D nonlinear analysis computer program based on this regulation. The analysis starts by hand calculation to define the required energy absorption by the chosen structure. Simple calculations were then performed to define the weakest collapse mechanism after undesirable collapse modes are eliminated. There are few factors highlighted in this work to pass the regulation. Using the selected cross section, Crash D simulation showed a good result. Generally, the deformation is linearly correlates to the energy absorption for the structure with low stiffness. Failure of critical members such as vertical lower side wall must be avoided to sustain safety of the passenger compartment and prevent from severe and fatal injuries to the trapped occupant.

  13. Quantification of plaque lipids in the aortic root of ApoE-deficient mice by 3D DIXON magnetic resonance imaging in an ex vivo model

    Energy Technology Data Exchange (ETDEWEB)

    Dietel, Barbara; Kuehn, Constanze; Achenbach, Stephan [University Hospital of Erlangen-Nuremberg, Department of Cardiology and Angiology, Erlangen (Germany); Budinsky, Lubos [Campus Science Support Facilities (CSF), Vienna Biocenter (VBC), Vienna (Austria); Uder, Michael [University Hospital of Erlangen-Nuremberg, Department of Radiology, Erlangen (Germany); Hess, Andreas [University of Erlangen-Nuremberg, Department of Experimental and Clinical Pharmacology and Toxicology, Erlangen (Germany)

    2014-10-31

    To establish a dedicated protocol for the three-dimensional (3D) quantification of plaque lipids in apolipoprotein E-deficient (apoE{sup -/-}) mice using ex vivo MRI. ApoE{sup -/-} mice were fed a high-fat diet (n = 10) or normal food (n = 10) for 3 months. Subsequently, a 3D FLASH MRI sequence was used to view the anatomy of the aortic root in the isolated hearts, where a 3D double-echo two-excitation pulse sequence (DIXON sequence) was used to selectively image plaque lipids. The vessel wall, lumen and plaque lipid volumes were quantified by MRI and histology for correlation analysis. DIXON MRI allowed visualisation and accurate quantification of plaque lipids. When comparing the vessel wall, lumen and plaque lipid sizes in the aortic root, Bland-Altman and linear regression analysis revealed a close correlation between MRI results and the histological data both on a slice-by-slice basis and of the volumetric measurements (vessel wall: r{sup 2} = 0.775, p < 0.001; vessel lumen: r{sup 2} = 0.875; p = 0.002; plaque lipid: r{sup 2} = 0.819, p = 0.003). The combination of 3D FLASH and DIXON-sequence MRI permits an accurate ex vivo assessment of the investigated plaque parameters in the aortic root of mice, particularly the lipid content. (orig.)

  14. Molecular mechanism study of intervention effect of Cassia seed on atherosclerotic plaque of rab-bits with hyperhomocysteinemia%决明子对高同型半胱氨酸血症兔动脉粥样斑块干预的分子机制研究

    Institute of Scientific and Technical Information of China (English)

    周路坦; 周玲生; 周银生; 丁可

    2014-01-01

    Objective To investigate the molecular mechanism of intervention effect of Cassia seed on atherosclerotic plaque of rabbits with hyperhomocysteinemia. Methods Forty rabbits were ran-domly divided into four groups:control group, methionine group,Cassia seed ﹢ methionine group,Lipitor﹢methionine group. Rabbits with hyperhomocysteinemia model were established using high L-methionine. The plasma levels of homocysteine( Hcy)in rabbits were compared among the four groups. The formation process of plaque was detected by vascular ultrasound,the expression levels of Bcl-2 and Bax were observed by immunohistochemistry,and the intervention effect of Cassia seed on the pathologic process of the disease was analyzed. Results Compared with methionine group,IMT of ab-dominal aorta and Vp of abdominal aorta decreased obviously in Cassia seed group and Lipitor group, there were significant differences( P ﹤0. 05 ),but there were no significant differences between Cassia seed group and Lipitor group( P ﹥0. 05 ). Immunohistochemistry showed that,there was significant difference in the Bax expression level between methionine group and control group( P﹤0. 01 ). Compared with methionine group,the positive expression rate of Bax in smooth muscle cells and foam cells de-creased,the expression levels of Bcl-2 increased slightly in Cassia seed group and Lipitor group,there were significant differences(P﹤0. 01). The ratio of Bax/Bcl-2 decreased in Cassia seed group. Conclu-sions Cassia seed can intervene the formation of atherosclerotic plaque of rabbits with hyperhomocys-teinemia through down-regulation the ratio of Bax/Bcl-2 .%目的:探讨决明子对高同型半胱氨酸( HHcy)血症兔动脉粥样斑块干预的分子机制。方法将40只家兔随机分成对照组、蛋氨酸组、决明子﹢蛋氨酸组、立普妥﹢蛋氨酸组。采用高L-蛋氨酸建立兔高同型半胱氨酸血症模型。比较各组兔血浆同型半胱氨酸( Hcy)含量,应用血

  15. Comparative Plaque Removal Efficacy of a New Powered Toothbrush and a Manual Toothbrush.

    Science.gov (United States)

    Vorwerk, L; Ghassemi, A; Hooper, W; Patel, V; Milleman, J; Milleman, K

    2016-09-01

    The purpose of this study was to determine the plaque removal effectiveness of a new powered toothbrush and compare it to that of a manual brush. This examiner-blind, randomized study used a cross-over design. Sixty-two (62) qualifying subjects were randomly assigned either to the powered brush (Arm & Hammer Spinbrush™ Truly Radiant™ Clean & Fresh Battery-Powered Toothbrush), or a standard manual toothbrush (ADA Standard Manual Toothbrush) and instructed to brush at home with a standard fluoride toothpaste twice daily for two minutes during a one-week familiarization period. At the end of this period, the subjects returned to the study site. After refraining from oral hygiene for 12-16 hours and from eating and drinking for four hours, plaque was disclosed by rinsing with an erythrosine dye solution and scored using the Rustogi Modification of the Navy Plaque Index (RMNPI). Subjects then brushed under supervision with their assigned toothbrush for two minutes, and plaque was disclosed and rescored. They were then given the alternate toothbrush, and the familiarization routine and evaluation process were repeated. The primary outcome variable was mean whole mouth RMNPI score with additional analyses performed on regional subsets of tooth surfaces. Within-group analysis showed that both toothbrushes produced statistically significant reductions from the pre-brushing baseline in whole mouth and regional plaque scores (p < 0.01), with respective whole mouth reductions of 40.7% and 24.9% for the powered brush and the manual brush. Between-group analyses showed that the powered brush produced a statistically significantly greater plaque reduction than the manual brush, both whole mouth (63.7%, p < 0.0001) and at all 12 subsets of sites. When evaluated using this single-use clinical model, the Arm & Hammer Spinbrush Truly Radiant Clean & Fresh powered toothbrush was statistically significantly more effective in reducing plaque than the manual toothbrush, both whole

  16. The Schwickerath adhesion test: A fracture mechanics analysis.

    Science.gov (United States)

    Schneider, G A; Swain, M V

    2015-08-01

    The Schwickerath three point bending adhesion test is the basis of the International Standard ISO 9693:1999 procedure for assessing porcelain bonding to metals [1]. It has also been used to evaluate the adhesion of porcelain to zirconia. The purpose of this paper is a fracture mechanics analysis of this test, which allows determination of the crack-length load-displacement and toughness dependence of cracks extending along or near the interface. Linear elastic mechanics is used to develop expressions for the strain energy and compliance of Schwickerath geometry specimens as a function of crack extension along or near the interface. From the derivative of the compliance as a function of crack growth the strain energy release rate (G, N/m) is determined. The energy release rate for interface crack extension of Schwickerath geometry specimens is determined. It is found that a simple relationship between the minima of the force-displacement response and the strain energy release rate G exists. Further development enables the predicted force-displacement response as a function of crack length to be derived for different values of G. Experimental results of porcelain bonded to zirconia with and without notches of various lengths machined along the interface verify the expressions and analysis developed. With the fracture mechanics analysis developed in this paper it is possible to determine the quality of adhesion in Schwickerath specimens by the interface toughness in addition to the nominal interface shear bond strength. As the toughness of brittle materials has much less scatter than its strength, the interface toughness characterization of the adhesion should allow for a better distinction between the adhesion quality of bonding. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. Discordant Lipid Pattern and Carotid Atherosclerotic Plaque. Importance of Remnant Cholesterol

    Science.gov (United States)

    Masson, Walter; Lobo, Martín; Molinero, Graciela; Siniawski, Daniel

    2017-01-01

    Background: Subjects with levels of non-HDL-C 30 mg/dL above those of LDL-C (lipid discordance) or with high remnant cholesterol levels could have a greater residual cardiovascular risk. Objectives: To determine the prevalence of lipid discordance in a primary prevention population and analyze the clinical variables associated with it;To investigate the association between lipid discordance and remnant cholesterol with the presence of carotid plaque. Methods: Primary prevention patients without diabetes or lipid-lowering therapy were included. Regardless of the LDL-C level, we define “lipid discordance” if the non-HDL-C value exceeded 30 mg/dL that of LDL-C. Remnant cholesterol was calculated as total cholesterol minus HDL-C minus LDL-C when triglycerides were < 4.0 mmol/L. Ultrasound was used to assess carotid plaque occurrence. Multiple regression logistic models were performed. Results: The study included 772 patients (mean age 52 ± 11 years, 66% women). The prevalence of lipid discordance was 34%. Male sex and body mass index were independently associated with discordant lipid pattern. The prevalence of carotid plaque was higher in subjects with lipid discordance (40.2% vs. 29.2, p = 0.002). The multivariate analysis showed that the discordant lipid pattern was associated with the greater probability of carotid plaque (OR 1.58, 95% CI 1.08-2.34, p = 0.02). Similarly, a significant association between calculated remnant cholesterol and carotid plaque was found. Conclusion: Lipid discordance and presence of a higher level of calculated remnant cholesterol are associated with subclinical atherosclerosis. Our findings could be used to improve the residual cardiovascular risk evaluation. PMID:28699976

  18. High-resolution intravascular magnetic resonance quantification of atherosclerotic plaque at 3T

    Directory of Open Access Journals (Sweden)

    Qian Di

    2012-03-01

    Full Text Available Abstract Background The thickness of fibrous caps (FCT of atherosclerotic lesions is a critical factor affecting plaque vulnerability to rupture. This study tests whether 3 Tesla high-resolution intravascular cardiovascular magnetic resonance (CMR employing tiny loopless detectors can identify lesions and accurately measure FCT in human arterial specimens, and whether such an approach is feasible in vivo using animal models. Methods Receive-only 2.2 mm and 0.8 mm diameter intravascular loopless CMR detectors were fabricated for a clinical 3 Tesla MR scanner, and the absolute signal-to-noise ratio determined. The detectors were applied in a two-step protocol comprised of CMR angiography to identify atherosclerotic lesions, followed by high-resolution CMR to characterize FCT, lesion size, and/or vessel wall thickness. The protocol was applied in fresh human iliac and carotid artery specimens in a human-equivalent saline bath. Mean FCT measured by 80 μm intravascular CMR was compared with histology of the same sections. In vivo studies compared aortic wall thickness and plaque size in healthy and hyperlipidemic rabbit models, with post-mortem histology. Results Histology confirmed plaques in human specimens, with calcifications appearing as signal voids. Mean FCT agreed with histological measurements within 13% on average (correlation coefficient, R = 0.98; Bland-Altman analysis, -1.3 ± 68.9 μm. In vivo aortic wall and plaque size measured by 80 μm intravascular CMR agreed with histology. Conclusion Intravascular 3T CMR with loopless detectors can both locate atherosclerotic lesions, and accurately measure FCT at high-resolution in a strategy that appears feasible in vivo. The approach shows promise for quantifying vulnerable plaque for evaluating experimental therapies.

  19. The usefulness of optical analyses for detecting vulnerable plaques using rabbit models

    Science.gov (United States)

    Nakai, Kanji; Ishihara, Miya; Kawauchi, Satoko; Shiomi, Masashi; Kikuchi, Makoto; Kaji, Tatsumi

    2011-03-01

    Purpose: Carotid artery stenting (CAS) has become a widely used option for treatment of carotid stenosis. Although technical improvements have led to a decrease in complications related to CAS, distal embolism continues to be a problem. The purpose of this research was to investigate the usefulness of optical methods (Time-Resolved Laser- Induced Fluorescence Spectroscopy [TR-LIFS] and reflection spectroscopy [RS] as diagnostic tools for assessment of vulnerable atherosclerotic lesions, using rabbit models of vulnerable plaque. Materials & Methods: Male Japanese white rabbits were divided into a high cholesterol diet group and a normal diet group. In addition, we used a Watanabe heritable hyperlipidemic (WHHL) rabbit, because we confirmed the reliability of our animal model for this study. Experiment 1: TR-LIFS. Fluorescence was induced using the third harmonic wave of a Q switch Nd:YAG laser. The TR-LIFS was performed using a photonic multi-channel analyzer with ICCD (wavelength range, 200 - 860 nm). Experiment 2: RS. Refection spectra in the wavelength range of 900 to 1700 nm were acquired using a spectrometer. Results: In the TR-LIFS, the wavelength at the peak was longer by plaque formation. The TR-LIFS method revealed a difference in peak levels between a normal aorta and a lipid-rich aorta. The RS method showed increased absorption from 1450 to 1500 nm for lipid-rich plaques. We observed absorption around 1200 nm due to lipid only in the WHHL group. Conclusion: These methods using optical analysis might be useful for diagnosis of vulnerable plaques. Keywords: Carotid artery stenting, vulnerable plaque, Time-Resolved Laser-Induced Fluorescence

  20. A Framework for Web-Based Mechanical Design and Analysis

    Institute of Scientific and Technical Information of China (English)

    Chiaming; Yen; Wujeng; Li

    2002-01-01

    In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to ...

  1. Stochastic Analysis of Mean Interference for RTS/CTS Mechanism

    CERN Document Server

    Zhong, Yi

    2012-01-01

    The RTS/CTS handshake mechanism in WLAN is studied using stochastic geometry. The effect of RTS/CTS is treated as a thinning procedure for a spatially distributed point process that models the potential transceivers in a WLAN, and the resulting concurrent transmission processes are described. Exact formulas for the intensity of the concurrent transmission processes and the mean interference experienced by a typical receiver are established. The analysis yields useful results for understanding how the design parameters of RTS/CTS affect the network interference.

  2. Groups as units of functional analysis, individuals as proximate mechanisms.

    Science.gov (United States)

    Wilson, David Sloan

    2014-06-01

    Whenever selection operates at a given level of a multitier hierarchy, units at that level should become the object of functional analysis, and units at lower levels should be studied as proximate mechanisms. This intuition already exists for the study of genes in individuals, when individuals are the unit of selection. It is only beginning to be applied for the study of individuals in groups, when groups are the unit of selection. Smaldino's target article is an important step in this direction with an emphasis on human cultural evolution, but the same algorithm applies to all multilevel evolutionary processes.

  3. Functional analysis and quantum mechanics: an introduction for physicists

    Energy Technology Data Exchange (ETDEWEB)

    Ranade, Kedar S. [Ulm Univ. (Germany). Inst. fuer Quantenphysik and Center for Integrated Quantum Science and Technology (IQST)

    2015-09-15

    We give an introduction to certain topics from functional analysis which are relevant for physics in general and in particular for quantum mechanics. Starting from some examples, we discuss the theory of Hilbert spaces, spectral theory of unbounded operators, distributions and their applications and present some facts from operator algebras. We do not give proofs, but present examples and analogies from physics which should be useful to get a feeling for the topics considered. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Coronary plaque quantification and fractional flow reserve by coronary computed tomography angiography identify ischaemia-causing lesions

    DEFF Research Database (Denmark)

    Gaur, Sara; Øvrehus, Kristian Altern; Dey, Damini

    2016-01-01

    tomography angiography (CTA)-derived fractional flow reserve (FFRCT), and lesion-specific ischaemia identified by FFR in a substudy of the NXT trial (Analysis of Coronary Blood Flow Using CT Angiography: Next Steps). METHODS AND RESULTS: Coronary CTA stenosis, plaque volumes, FFRCT, and FFR were assessed...... the receiver-operating characteristics curve (AUC) analysis. Ischaemia was defined by FFR or FFRCT ≤0.80. Plaque volumes were inversely related to FFR irrespective of stenosis severity. Relative risk (95% confidence interval) for prediction of ischaemia for stenosis >50%, NCP ≥185 mm(3), LD-NCP ≥30 mm(3), CP...

  5. Diameter of basalt columns derived from fracture mechanics bifurcation analysis.

    Science.gov (United States)

    Bahr, H-A; Hofmann, M; Weiss, H-J; Bahr, U; Fischer, G; Balke, H

    2009-05-01

    The diameter of columnar joints forming in cooling basalt and drying starch increases with decreasing growth rate. This observation can be reproduced with a linear-elastic three-dimensional fracture mechanics bifurcation analysis, which has been done for a periodic array of hexagonal columnar joints by considering a bifurcation mode compatible with observations on drying starch. In order to be applicable to basalt columns, the analysis has been carried out with simplified stationary temperature fields. The critical diameter differs from the one derived with a two-dimensional model by a mere factor of 1/2. By taking into account the latent heat released at the solidification front, the results agree fairly well with observed column diameters.

  6. Cell mechanics through analysis of cell trajectories in microfluidic channel

    Science.gov (United States)

    Bowie, Samuel; Alexeev, Alexander; Sulchek, Todd

    The understanding of dynamic cell behavior can aid in research ranging from the mechanistic causes of diseases to the development of microfluidic devices for cancer detection. Through analysis of trajectories captured from video of the cells moving in a specially designed microfluidic device, insight into the dynamic viscoelastic nature of cells can be found. The microfluidic device distinguishes cells viscoelastic properties through the use of angled ridges causing a series of compressions, resulting in differences in trajectories based on cell stiffness. Trajectories of cell passing through the device are collected using image processing methods and data mining techniques are used to relate the trajectories to cell properties obtained from experiments. Furthermore, numerical simulation of the cell and microfluidic device are used to match the experimental results from the trajectory analysis. Combination of the modeling and experimental data help to uncover how changes in cellular structures result in changes in mechanical properties.

  7. Differences in root aeration, iron plaque formation and waterlogging tolerance in six mangroves along a continues tidal gradient.

    Science.gov (United States)

    Cheng, Hao; Wang, You-Shao; Fei, Jiao; Jiang, Zhao-Yu; Ye, Zhi-Hong

    2015-10-01

    Mangrove is a special coastal forest along tropical and subtropical intertidal shores. However, how mangroves adapt to tidal flooding and the mechanisms involved in mangrove zonation are still poorly understood. In this study, a pot trial with different tide treatments was conducted to investigate the differences in root anatomy, porosity, radial oxygen loss, iron plaque formation and waterlogging tolerance among six mangroves along a continuous tidal gradient. The index of waterlogging tolerance illustrated that Sonneratia apetala possessed the highest index, followed by Aeguceras corniculatum/Kandelia, Rhizophora stylosa, Heritiera littorlis and Thespesia populnea. Waterlogging tolerances of the mangroves were found to be positively correlated with their root porosity, radial oxygen loss and iron plaque formation. Waterlogging-sensitive species such as landward semi-mangroves exhibited small root porosity and ROL, while waterlogging-tolerant species such as seaward pioneer and rhizophoraceous mangroves exhibited extensive porosity, ROL and iron plaque formation. Nevertheless, grater root porosity and iron plaque formation were detected in permanent waterlogged plants when compared to drained plants. In conclusion, The present study proposes a structural adaptive strategy to tidal flooding in mangroves, such that the mangroves with higher root porosity, ROL and iron plaque appeared to exhibit higher waterlogging tolerance and adaptability in anaerobic foreshores.

  8. Grating-based X-ray phase-contrast tomography of atherosclerotic plaque at high photon energies

    Energy Technology Data Exchange (ETDEWEB)

    Hetterich, Holger; Fill, Sandra [Klinikum der Ludwig-Maximilians-Univ., Muenchen (Germany). Inst. fuer Klinische Radiologie; Herzen, Julia [Technische Univ. Muenchen, Garching (Germany). Physik-Dept. und Inst. fuer Medizintechnik; Helmholtz-Zentrum Geesthacht, Geesthacht (Germany). Zentrum fuer Materialforschung] [and others

    2013-10-01

    Background: Tissue characterization of atherosclerosis by absorption-based imaging methods is limited due to low soft-tissue contrast. Grating-based phase-contrast computed tomography (PC-CT) may become an alternative for plaque assessment if the phase signal can be retrieved at clinically applicable photon energies. The aims of this feasibility study were (i) to characterize arterial vessels at low and high photon energies, (ii) to extract qualitative features and (iii) quantitative phase-contrast Hounsfield units (HU-phase) of plaque components at 53 keV using histopathology as gold standard. Materials and methods: Five human carotid artery specimens underwent grating-based PC-CT using synchrotron radiation of either 23 keV or 53 keV and histological work-up. Specimens without advanced atherosclerosis were used to extract signal criteria of vessel layers. Diseased specimens were screened for important plaque components including fibrous tissue (FT), lipid (LIP), necrotic core (NEC), intraplaque hemorrhage (IPH), inflammatory cell infiltration (INF) and calcifications (CA). Qualitative features as well as quantitative HU-phase were analyzed. Results: Thirty-three regions in 6 corresponding PC-CT scans and histology sections were identified. Healthy samples had the same signal characteristics at 23 keV and 53 keV with bright tunica intima and adventitia and dark media. Plaque components showed differences in signal intensity and texture at 53 keV. Quantitative analysis demonstrated the highest HU-phase of soft