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Sample records for accurate plaque vulnerability

  1. The vulnerable and unstable atherosclerotic plaque.

    PubMed

    Fishbein, Michael C

    2010-01-01

    The lesion responsible for the overwhelming majority of acute coronary events is plaque disruption or erosion with superimposed thrombosis. The term "vulnerable plaque" has been used to describe those atherosclerotic plaques that are particularly susceptible to disruption. Vulnerable plaques are generally characterized as those having a thin inflamed fibrous cap over a very large lipid core. However, only a small percentage of such plaques rupture, and plaques with different characteristics may also rupture and thrombose. Most autopsy, intravascular ultrasound, and recent computed tomography angiographic studies of coronary arteries reveal large plaques at sites of rupture. While angiographic data are said to show less severe narrowing at sites of plaque rupture, actual review of data indicates that, even angiographically, more than 50% of plaques have greater than 75% cross-sectional area stenosis at sites of plaque rupture. If plaque rupture is more common at the shoulder region of a plaque, one could envision that this would be at a peripheral site of the plaque where the plaque may not be as large or occlusive. New knowledge about vulnerable plaques is emerging through the evolution of novel techniques used to study plaques in vivo. These methods combine sophisticated imaging techniques, often in conjunction with molecular biomarkers, that provide new insights into plaque biology. Since atherosclerotic coronary artery disease is such a widespread and fatal disease, it is important that we continue to strive for a greater understanding of the nature of the vulnerable plaque. Only then can rational interventions for this disorder be developed and implemented.

  2. Nuclear Molecular Imaging for Vulnerable Atherosclerotic Plaques

    PubMed Central

    Lee, Soo Jin

    2015-01-01

    Atherosclerosis is an inflammatory disease as well as a lipid disorder. Atherosclerotic plaque formed in vessel walls may cause ischemia, and the rupture of vulnerable plaque may result in fatal events, like myocardial infarction or stroke. Because morphological imaging has limitations in diagnosing vulnerable plaque, molecular imaging has been developed, in particular, the use of nuclear imaging probes. Molecular imaging targets various aspects of vulnerable plaque, such as inflammatory cell accumulation, endothelial activation, proteolysis, neoangiogenesis, hypoxia, apoptosis, and calcification. Many preclinical and clinical studies have been conducted with various imaging probes and some of them have exhibited promising results. Despite some limitations in imaging technology, molecular imaging is expected to be used both in the research and clinical fields as imaging instruments become more advanced. PMID:26357491

  3. Imaging atherosclerosis and vulnerable plaque.

    PubMed

    Sadeghi, Mehran M; Glover, David K; Lanza, Gregory M; Fayad, Zahi A; Johnson, Lynne L

    2010-05-01

    Identifying patients at high risk for an acute cardiovascular event such as myocardial infarction or stroke and assessing the total atherosclerotic burden are clinically important. Currently available imaging modalities can delineate vascular wall anatomy and, with novel probes, target biologic processes important in plaque evolution and plaque stability. Expansion of the vessel wall involving remodeling of the extracellular matrix can be imaged, as can angiogenesis of the vasa vasorum, plaque inflammation, and fibrin deposits on early nonocclusive vascular thrombosis. Several imaging platforms are available for targeted vascular imaging to acquire information on both anatomy and pathobiology in the same imaging session using either hybrid technology (nuclear combined with CT) or MRI combined with novel probes targeting processes identified by molecular biology to be of importance. This article will discuss the current state of the art of these modalities and challenges to clinical translation.

  4. Growth of Necrotic Cores in Vulnerable Plaque

    NASA Astrophysics Data System (ADS)

    Fok, Pak-Wing

    2011-03-01

    Plaques are fatty deposits that grow mainly in arteries and develop as a result of a chronic inflammatory response. Plaques are called vulnerable when they are prone to mechanical rupture. Vulnerable Plaques (VPs) are characterized by lipid-rich, necrotic cores that are heavily infiltrated with macrophages. The rupture of VPs releases thrombogenic agents into the bloodstream, usually resulting in myocardial infarctions. We propose a quantitative model to predict the development of a plaque's necrotic core. By solving coupled reaction-diffusion equations for macrophages and dead cells, we explore the joint effects of hypoxic cell death and chemo-attraction to Ox-LDL, a molecule that is strongly linked to atherosclerosis. Our model predicts cores that have approximately the right size and shape. Normal mode analysis and subsequent calculation of the smallest eigenvalues allow us to compute the times required for the system to reach its steady state. This study allows us to make quantitative predictions for how quickly vulnerable plaques develop and how their growth depends on system parameters such as chemotactic coefficients and cell death rates.

  5. Noninvasive diagnosis of vulnerable coronary plaque

    PubMed Central

    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

  6. Intravascular probe for detection of vulnerable plaque

    NASA Astrophysics Data System (ADS)

    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

  7. Contemporary carotid imaging: from degree of stenosis to plaque vulnerability.

    PubMed

    Brinjikji, Waleed; Huston, John; Rabinstein, Alejandro A; Kim, Gyeong-Moon; Lerman, Amir; Lanzino, Giuseppe

    2016-01-01

    Carotid artery stenosis is a well-established risk factor of ischemic stroke, contributing to up to 10%-20% of strokes or transient ischemic attacks. Many clinical trials over the last 20 years have used measurements of carotid artery stenosis as a means to risk stratify patients. However, with improvements in vascular imaging techniques such as CT angiography and MR angiography, ultrasonography, and PET/CT, it is now possible to risk stratify patients, not just on the degree of carotid artery stenosis but also on how vulnerable the plaque is to rupture, resulting in ischemic stroke. These imaging techniques are ushering in an emerging paradigm shift that allows for risk stratifications based on the presence of imaging features such as intraplaque hemorrhage (IPH), plaque ulceration, plaque neovascularity, fibrous cap thickness, and presence of a lipid-rich necrotic core (LRNC). It is important for the neurosurgeon to be aware of these new imaging techniques that allow for improved patient risk stratification and outcomes. For example, a patient with a low-grade stenosis but an ulcerated plaque may benefit more from a revascularization procedure than a patient with a stable 70% asymptomatic stenosis with a thick fibrous cap. This review summarizes the current state-of-the-art advances in carotid plaque imaging. Currently, MRI is the gold standard in carotid plaque imaging, with its high resolution and high sensitivity for identifying IPH, ulceration, LRNC, and inflammation. However, MRI is limited due to time constraints. CT also allows for high-resolution imaging and can accurately detect ulceration and calcification, but cannot reliably differentiate LRNC from IPH. PET/CT is an effective technique to identify active inflammation within the plaque, but it does not allow for assessment of anatomy, ulceration, IPH, or LRNC. Ultrasonography, with the aid of contrast enhancement, is a cost-effective technique to assess plaque morphology and characteristics, but it is

  8. Spectroscopy to improve identification of vulnerable plaques in cardiovascular disease.

    PubMed

    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.

  9. The Vulnerable Plaque: the Real Villain in Acute Coronary Syndromes

    PubMed Central

    Liang, Michael; Puri, Aniket; Devlin, Gerard

    2011-01-01

    The term "vulnerable plaque" refers to a vascular lesion that is prone to rupture and may result in life-threatening events which include myocardial infarction. It consists of thin-cap fibroatheroma and a large lipid core which is highly thrombogenic. Acute coronary syndromes often result from rupture of vulnerable plaques which frequently are only moderately stenosed and not visible by conventional angiography. Several invasive and non-invasive strategies have been developed to assess the burden of vulnerable plaques. Intravascular ultrasound provides a two-dimensional cross-sectional image of the arterial wall and can help assess the plaque burden and composition. Optical coherent tomography offers superior resolution over intravascular ultrasound. High-resolution magnetic resonance imaging provides non-invasive imaging for visualizing fibrous cap thickness and rupture in plaques. In addition, it may be of value in assessing the effects of treatments, such as lipid-lowering therapy. Technical issues however limit its clinical applicability. The role of multi-slice computed tomography, a well established screening tool for coronary artery disease, remains to be determined. Fractional flow reserve (FFR) may provide physiological functional assessment of plaque vulnerability; however, its role in the management of vulnerable plaque requires further studies. Treatment of the vulnerable patient may involve systemic therapy which currently include statins, ACE inhibitors, beta-blockers, aspirin, and calcium-channel blockers and in the future local therapeutic options such as drug-eluting stents or photodynamic therapy. PMID:21673834

  10. High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis

    PubMed Central

    Wang, Yi; Qiu, Juhui; Luo, Shisui; Xie, Xiang; Zheng, Yiming; Zhang, Kang; Ye, Zhiyi; Liu, Wanqian; Gregersen, Hans; Wang, Guixue

    2016-01-01

    Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions. PMID:27482467

  11. Multimodal spectroscopy detects features of vulnerable atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    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.

  12. Intracoronary Imaging in the Detection of Vulnerable Plaques.

    PubMed

    Batty, Jonathan A; Subba, Shristy; Luke, Peter; Gigi, Li Wing Chi; Sinclair, Hannah; Kunadian, Vijay

    2016-03-01

    Coronary artery disease is the result of atherosclerotic changes to the coronary arterial wall, comprising endothelial dysfunction, vascular inflammation and deposition of lipid-rich macrophage foam cells. Certain high-risk atherosclerotic plaques are vulnerable to disruption, leading to rupture, thrombosis and the clinical sequelae of acute coronary syndrome. Though recognised as the gold standard for evaluating the presence, distribution and severity of atherosclerotic lesions, invasive coronary angiography is incapable of identifying non-stenotic, vulnerable plaques that are responsible for adverse cardiovascular events. The recognition of such limitations has impelled the development of intracoronary imaging technologies, including intravascular ultrasound, optical coherence tomography and near-infrared spectroscopy, which enable the detailed evaluation of the coronary wall and atherosclerotic plaques in clinical practice. This review discusses the present status of invasive imaging technologies; summarises up-to-date, evidence-based clinical guidelines; and addresses questions that remain unanswered with regard to the future of intracoronary plaque imaging.

  13. A computational fluid-structure interaction model for plaque vulnerability assessment in atherosclerotic human coronary arteries

    NASA Astrophysics Data System (ADS)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza; Haghpanahi, Mohammad

    2014-04-01

    Coronary artery disease is responsible for a third of global deaths worldwide. Computational simulations of blood flow can be used to understand the interactions of artery/plaque and blood in coronary artery disease and to better predict the rupture of atherosclerotic plaques. So far, the mechanical properties of animals' coronary artery have been mostly used for hemodynamic simulation of atherosclerotic arteries. The mechanical properties of animals' coronary arteries are often not accurate enough and can be only used for an approximate estimation and comparative assessment of the cognate parameters in human. In this study, a three-dimensional (3D) computational fluid-structure interactions model with three different plaque types is presented to perform a more accurate plaque vulnerability assessment for human atherosclerotic plaques. The coronary arteries of twenty-two male individuals were removed during autopsy and subjected to uniaxial tensile loading. The hyperelastic material coefficients of coronary arteries were calculated and implemented to the computational model. The fully coupled fluid and structure models were solved using the explicit dynamics finite element code LS-DYNA. The normal and shear stresses induced within the plaques were significantly affected by different plaque types. The highest von Mises (153 KPa) and shear (57 KPa) stresses were observed for hypocellular plaques, while the lowest von Mises (70 KPa) and shear (39 KPa) stresses were observed on the stiffer calcified plaques. The results suggest that the risk of plaque rupture due to blood flow is lower for cellular and hypocellular plaques, while higher for calcified plaques with low fracture stresses.

  14. Vulnerable atherosclerotic plaque detection by resonance Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Cheng-hui; Boydston-White, Susie; Weisberg, Arel; Wang, Wubao; Sordillo, Laura A.; Perotte, Adler; Tomaselli, Vincent P.; Sordillo, Peter P.; Pei, Zhe; Shi, Lingyan; Alfano, Robert R.

    2016-12-01

    A clear correlation has been observed between the resonance Raman (RR) spectra of plaques in the aortic tunica intimal wall of a human corpse and three states of plaque evolution: fibrolipid plaques, calcified and ossified plaques, and vulnerable atherosclerotic plaques (VPs). These three states of atherosclerotic plaque lesions demonstrated unique RR molecular fingerprints from key molecules, rendering their spectra unique with respect to one another. The vibrational modes of lipids, cholesterol, carotenoids, tryptophan and heme proteins, the amide I, II, III bands, and methyl/methylene groups from the intrinsic atherosclerotic VPs in tissues were studied. The salient outcome of the investigation was demonstrating the correlation between RR measurements of VPs and the thickness measurements of fibrous caps on VPs using standard histopathology methods, an important metric in evaluating the stability of a VP. The RR results show that VPs undergo a structural change when their caps thin to 66 μm, very close to the 65-μm empirical medical definition of a thin cap fibroatheroma plaque, the most unstable type of VP.

  15. Molecular Imaging of Vulnerable Atherosclerotic Plaques in Animal Models

    PubMed Central

    Gargiulo, Sara; Gramanzini, Matteo; Mancini, Marcello

    2016-01-01

    Atherosclerosis is characterized by intimal plaques of the arterial vessels that develop slowly and, in some cases, may undergo spontaneous rupture with subsequent heart attack or stroke. Currently, noninvasive diagnostic tools are inadequate to screen atherosclerotic lesions at high risk of acute complications. Therefore, the attention of the scientific community has been focused on the use of molecular imaging for identifying vulnerable plaques. Genetically engineered murine models such as ApoE−/− and ApoE−/−Fbn1C1039G+/− mice have been shown to be useful for testing new probes targeting biomarkers of relevant molecular processes for the characterization of vulnerable plaques, such as vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, intercellular adhesion molecule (ICAM)-1, P-selectin, and integrins, and for the potential development of translational tools to identify high-risk patients who could benefit from early therapeutic interventions. This review summarizes the main animal models of vulnerable plaques, with an emphasis on genetically altered mice, and the state-of-the-art preclinical molecular imaging strategies. PMID:27618031

  16. In vivo Raman spectral pathology of human atherosclerosis and vulnerable plaque

    NASA Astrophysics Data System (ADS)

    Motz, Jason T.; Fitzmaurice, Maryann; Miller, Arnold; Gandhi, Saumil J.; Haka, Abigail S.; Galindo, Luis; Dasari, Ramachandra R.; Kramer, John R., Jr.; Feld, Michael S.

    2006-03-01

    The rupture of vulnerable atherosclerotic plaque accounts for the majority of clinically significant acute cardiovascular events. Because stability of these culprit lesions is directly related to chemical and morphological composition, Raman spectroscopy may be a useful technique for their study. Recent developments in optical fiber probe technology have allowed for the real-time in vivo Raman spectroscopic characterization of human atherosclerotic plaque demonstrated in this work. We spectroscopically examine 74 sites during carotid endarterectomy and femoral artery bypass surgeries. Of these, 34 are surgically biopsied and examined histologically. Excellent signal-to-noise ratio spectra are obtained in only 1 s and fit with an established model, demonstrating accurate tissue characterization. We also report the first evidence that Raman spectroscopy has the potential to identify vulnerable plaque, achieving a sensitivity and specificity of 79 and 85%, respectively. These initial findings indicate that Raman spectroscopy has the potential to be a clinically relevant diagnostic tool for studying cardiovascular disease.

  17. Optical coherence tomography for imaging the vulnerable plaque

    NASA Astrophysics Data System (ADS)

    Tearney, Guillermo J.; Jang, Ik-Kyung; Bouma, Brett E.

    2006-03-01

    While our understanding of vulnerable coronary plaque is still at an early stage, the concept that certain types of plaques predispose patients to developing an acute myocardial infarction continues to be at the forefront of cardiology research. Intracoronary optical coherence tomography (OCT) has been developed to both identify and study these lesions due to its distinct resolution advantage over other imaging modalities. We review clinical research conducted at the Massachusetts General Hospital over the past five years to develop, validate, and utilize this technology to improve our understanding of vulnerable plaque. Our results show that intracoronary OCT may be safely conducted in patients and that it provides abundant information regarding plaque microscopic morphology, which is essential to the identification and study of high-risk lesions. Even though many basic biological, clinical, and technological challenges must be addressed prior to widespread use of this technology, the unique capabilities of OCT ensure that it will have a prominent role in shaping the future of cardiology.

  18. Macrophage-targeted photodynamic detection of vulnerable atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Hamblin, Michael R.; Tawakol, Ahmed; Castano, Ana P.; Gad, Faten; Zahra, Touqir; Ahmadi, Atosa; Stern, Jeremy; Ortel, Bernhard; Chirico, Stephanie; Shirazi, Azadeh; Syed, Sakeena; Muller, James E.

    2003-06-01

    Rupture of a vulnerable atherosclerotic plaque (VP) leading to coronary thrombosis is the chief cause of sudden cardiac death. VPs are angiographically insignificant lesions, which are excessively inflamed and characterized by dense macrophage infiltration, large necrotic lipid cores, thin fibrous caps, and paucity of smooth muscle cells. We have recently shown that chlorin(e6) conjugated with maleylated albumin can target macrophages with high selectivity via the scavenger receptor. We report the potential of this macrophage-targeted fluorescent probe to localize in VPs in a rabbit model of atherosclerosis, and allow detection and/or diagnosis by fluorescence spectroscopy or imaging. Atherosclerotic lesions were induced in New Zealand White rabbit aortas by balloon injury followed by administration of a high-fat diet. 24-hours after IV injection of the conjugate into atherosclerotic or normal rabbits, the animals were sacrificed, and aortas were removed, dissected and examined for fluorescence localization in plaques by fiber-based spectrofluorimetry and confocal microscopy. Dye uptake within the aortas was also quantified by fluorescence extraction of samples from aorta segments. Biodistribution of the dye was studied in many organs of the rabbits. Surface spectrofluorimetry after conjugate injection was able to distinguish between plaque and adjacent aorta, between atherosclerotic and normal aorta, and balloon-injured and normal iliac arteries with high significance. Discrete areas of high fluorescence (up to 20 times control were detected in the balloon-injured segments, presumably corresponding to macrophage-rich plaques. Confocal microscopy showed red ce6 fluorescence localized in plaques that showed abundant foam cells and macrophages by histology. Extraction data on aortic tissue corroborated the selectivity of the conjugate for plaques. These data support the strategy of employing macrophage-targeted fluorescent dyes to detect VP by intravascular

  19. Spectral CT imaging of vulnerable plaque with two independent biomarkers

    NASA Astrophysics Data System (ADS)

    Baturin, Pavlo; Alivov, Yahya; Molloi, Sabee

    2012-07-01

    The purpose of this paper is to investigate the feasibility of a novel four-material decomposition technique for assessing the vulnerability of plaque with two contrast materials spectral computer tomography (CT) using two independent markers: plaque's inflammation and spotty calcification. A simulation study was conducted using an energy-sensitive photon-counting detector for k-edge imaging of the coronary arteries. In addition to detecting the inflammation status, which is known as a biological marker of a plaque's vulnerability, we use spotty calcium concentration as an independent marker to test a plaque's vulnerability. We have introduced a new method for detecting and quantifying calcium concentrations in the presence of two contrast materials (iodine and gold), calcium and soft tissue background. In this method, four-material decomposition was performed on a pixel-by-pixel basis, assuming there was an arbitrary mixture of materials in the voxel. The concentrations of iodine and gold were determined by the k-edge material decomposition based on the maximum likelihood method. The calibration curves of the attenuation coefficients, with respect to the concentrations of different materials, were used to separate the calcium signal from both contrast materials and different soft tissues in the mixtures. Three different materials (muscle, blood and lipid) were independently used as soft tissue. The simulations included both ideal and more realistic energy resolving detectors to measure the polychromatic photon spectrum in single slice parallel beam geometry. The ideal detector was used together with a 3 cm diameter digital phantom to demonstrate the decomposition method while a more realistic detector and a 33 × 24 cm2 digital chest phantom were simulated to validate the vulnerability assessment technique. A 120 kVp spectrum was generated to produce photon flux sufficient for detecting contrast materials above the k-edges of iodine (33.2 keV) and gold (80.7 ke

  20. Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging

    NASA Astrophysics Data System (ADS)

    Doherty, Joshua Ryan

    The rupture of arterial plaques is the most common cause of ischemic complications including stroke, the fourth leading cause of death and number one cause of long term disability in the United States. Unfortunately, because conventional diagnostic tools fail to identify plaques that confer the highest risk, often a disabling stroke and/or sudden death is the first sign of disease. A diagnostic method capable of characterizing plaque vulnerability would likely enhance the predictive ability and ultimately the treatment of stroke before the onset of clinical events. This dissertation evaluates the hypothesis that Acoustic Radiation Force Impulse (ARFI) imaging can noninvasively identify lipid regions, that have been shown to increase a plaque's propensity to rupture, within carotid artery plaques in vivo. The work detailed herein describes development efforts and results from simulations and experiments that were performed to evaluate this hypothesis. To first demonstrate feasibility and evaluate potential safety concerns, finite- element method simulations are used to model the response of carotid artery plaques to an acoustic radiation force excitation. Lipid pool visualization is shown to vary as a function of lipid pool geometry and stiffness. A comparison of the resulting Von Mises stresses indicates that stresses induced by an ARFI excitation are three orders of magnitude lower than those induced by blood pressure. This thesis also presents the development of a novel pulse inversion harmonic tracking method to reduce clutter-imposed errors in ultrasound-based tissue displacement estimates. This method is validated in phantoms and was found to reduce bias and jitter displacement errors for a marked improvement in image quality in vivo. Lastly, this dissertation presents results from a preliminary in vivo study that compares ARFI imaging derived plaque stiffness with spatially registered composition determined by a Magnetic Resonance Imaging (MRI) gold standard

  1. Application of IR and NIR fiber optic imaging in thermographic and spectroscopic diagnosis of atherosclerotic vulnerable plaques: preliminary experience

    NASA Astrophysics Data System (ADS)

    Naghavi, Morteza; Khan, Tania; Gu, Bujin; Soller, Babs R.; Melling, Peter; Asif, Mohammed; Gul, Khawar; Madjid, Mohammad; Casscells, S. W.; Willerson, James T.

    2000-12-01

    Despite major advances in cardiovascular science and technology during the past three decades, approximately half of all myocardial infarctions and sudden deaths occur unexpectedly. It is widely accepted that coronary atherosclerotic plaques and thrombotic complications resulting from their rupture or erosion are the underlying causes of this major health problem. The majority of these vulnerable plaques exhibit active inflammation, a large necrotic lipid core, a thin fibrous cap, and confer a stenosis of less than 70%. These lesions are not detectable by stress testing or coronary angiography. Our group is exploring the possibility of a functional classification based on physiological variables such as plaque temperature, pH, oxygen consumption, lactate production etc. We have shown that heat accurately locates the inflamed plaques. We also demonstrated human atherosclerotic plaques are heterogeneous with regard to pH and hot plaques and are more likely to be acidic. To develop a nonsurgical method for locating the inflamed plaques, we are developing both IR fiber optic imaging and NIR spectroscopic systems in our laboratory to detect hot and acidic plaque in atherosclerotic arterial walls. Our findings introduce the possibility of an isolated/combined IR and NIR fiber optic catheter that can bring new insight into functional assessment of atherosclerotic plaque and thereby detection of active and inflamed lesions responsible for heart attacks and strokes.

  2. Is Cadmium Exposure Associated with the Burden, Vulnerability and Rupture of Human Atherosclerotic Plaques?

    PubMed Central

    Sallsten, Gerd; Lundh, Thomas; Barregard, Lars

    2015-01-01

    The general population is exposed to cadmium from food and smoking. Cadmium is a widely spread toxic pollutant that seems to be associated with cardiovascular diseases, although little is known if it contributes to the occurrence of atherosclerotic plaques and the process whereby plaques become vulnerable and are prone to rupture. We tested the hypotheses that cadmium exposure is associated not only with an increased subclinical burden of atherosclerotic plaques in different vascular territories and early signs of plaque vulnerability, but also with cadmium content and plaque-rupture in the clinical phase of the disease. Ultrasound technique was used to measure plaque prevalence and echogenicity in the carotid and femoral arteries in a population sample of women (n = 599) in whom blood cadmium was measured. In addition cadmium was measured in snap-frozen endarterectomies and whole blood obtained from patients who were referred to surgery because of symptomatic carotid plaques (n = 37). Sixteen endarterectomies were divided into three parts corresponding to different flow conditions and plaque vulnerability. In the population sample blood cadmium was associated with the number of vascular territories with plaques (p = 0.003 after adjustment for potential confounders). The cadmium concentrations in symptomatic plaques were 50-fold higher in plaque tissue than in blood. Cadmium levels in blood and plaque correlated, also after adjustment for smoking and other cardiovascular risk factors (p<0.001). Compared with the other parts of the plaque, the cadmium content was double as high in the part where plaque rupture usually occurs. In conclusion, the results show that cadmium exposure is associated with the burden of subclinical atherosclerosis in middle-aged women with different degrees of glucose tolerance, and that the content of cadmium in symptomatic plaques in patients is related to that in blood, but much higher, and preferentially located in the part of plaque

  3. Imaging Coronary Atherosclerosis and Vulnerable Plaques with Optical Coherence Tomography

    NASA Astrophysics Data System (ADS)

    Tearney, Guillermo J.; Jang, Ik-Kyung; Kashiwagi, Manubu; Bouma, Brett E.

    Intracoronary optical coherence tomography (OCT) is an invasive microscopic imaging technology that has been developed for the identification of vulnerable plaque. OCT acquires cross-sectional images of tissue reflectance and, since it may be implemented through an optical fiber probe, it is readily adaptable to coronary catheters for insertion into coronary arteries and circumferential imaging of arterial pathology. The first investigation of vascular optical coherence tomography ex vivo demonstrated the potential of this technique to identify arterial microstructure. Subsequent development of OCT technology enabled image acquisition at rates sufficient for intracoronary imaging in human patients. In this chapter, we review studies conducted with this technology at the Massachusetts General Hospital (MGH). Results from these studies show that a wide variety of microscopic features, including those associated with TCFAs, can be identified by OCT imaging both ex vivo and in living human patients. These findings suggest that this technology will play an important role in improving our understanding of coronary artery disease, guiding local therapy, and decreasing themortality of AMI.

  4. Cap buckling as a potential mechanism of atherosclerotic plaque vulnerability.

    PubMed

    Abdelali, Maria; Reiter, Steven; Mongrain, Rosaire; Bertrand, Michel; L'Allier, Philippe L; Kritikou, Ekaterini A; Tardif, Jean-Claude

    2014-04-01

    Plaque rupture in atherosclerosis is the primary cause of potentially deadly coronary events, yet about 40% of ruptures occur away from the plaque cap shoulders and cannot be fully explained with the current biomechanical theories. Here, cap buckling is considered as a potential destabilizing factor which increases the propensity of the atherosclerotic plaque to rupture and which may also explain plaque failure away from the cap shoulders. To investigate this phenomenon, quasistatic 2D finite element simulations are performed, considering the salient geometrical and nonlinear material properties of diverse atherosclerotic plaques over the range of physiological loads. The numerical results indicate that buckling may displace the location of the peak von Mises stresses in the deflected caps. Plaque buckling, together with its deleterious effects is further observed experimentally in plaque caps using a physical model of deformable mock coronary arteries with fibroatheroma. Moreover, an analytical approach combining quasistatic equilibrium equations with the Navier-Bresse formulas is used to demonstrate the buckling potential of a simplified arched slender cap under intraluminal pressure and supported by foundations. This analysis shows that plaque caps - calcified, fibrotic or cellular - may buckle in specific undulated shapes once submitted to critical loads. Finally, a preliminary analysis of intravascular ultrasonography recordings of patients with atherosclerotic coronary arteries corroborates the numerical, experimental and theoretical findings and shows that various plaque caps buckle in vivo. By displacing the sites of high stresses in the plaque cap, buckling may explain the atherosclerotic plaque cap rupture at various locations, including cap shoulders.

  5. Ultrasound-Based Carotid Elastography for Detection of Vulnerable Atherosclerotic Plaques Validated by Magnetic Resonance Imaging.

    PubMed

    Huang, Chengwu; Pan, Xiaochang; He, Qiong; Huang, Manwei; Huang, Lingyun; Zhao, Xihai; Yuan, Chun; Bai, Jing; Luo, Jianwen

    2016-02-01

    Ultrasound-based carotid elastography has been developed to estimate the mechanical properties of atherosclerotic plaques. The objective of this study was to evaluate the in vivo capability of carotid elastography in vulnerable plaque detection using high-resolution magnetic resonance imaging as reference. Ultrasound radiofrequency data of 46 carotid plaques from 29 patients (74 ± 5 y old) were acquired and inter-frame axial strain was estimated with an optical flow method. The maximum value of absolute strain rate for each plaque was derived as an indicator for plaque classification. Magnetic resonance imaging of carotid arteries was performed on the same patients to classify the plaques into stable and vulnerable groups for carotid elastography validation. The maximum value of absolute strain rate was found to be significantly higher in vulnerable plaques (2.15 ± 0.79 s(-1), n = 27) than in stable plaques (1.21 ± 0.37 s(-1), n = 19) (p < 0.0001). Receiver operating characteristic curve analysis was performed, and the area under the curve was 0.848. Therefore, the in vivo capability of carotid elastography to detect vulnerable plaques, validated by magnetic resonance imaging, was proven, revealing the potential of carotid elastography as an important tool in atherosclerosis assessment and stroke prevention.

  6. Detection of vulnerable atherosclerosis plaques with a dual-modal single-photon-emission computed tomography/magnetic resonance imaging probe targeting apoptotic macrophages.

    PubMed

    Cheng, Dengfeng; Li, Xiao; Zhang, Chunfu; Tan, Hui; Wang, Cong; Pang, Lifang; Shi, Hongcheng

    2015-02-04

    Atherosclerosis (AS), especially the vulnerable AS plaque rupture-induced acute obstructive vascular disease, is a leading cause of death. Accordingly, there is a need for an effective method to draw accurate predictions about AS progression and plaque vulnerability. Herein we report on an approach to constructing a hybrid nanoparticle system using a single-photon-emission computed tomography (SPECT)/magnetic resonance imaging (MRI) multimodal probe, aiming for a comprehensive evaluation of AS progression by achieving high sensitivity along with high resolution. Ultrasmall superparamagnetic iron oxide (USPIO) was covered by aminated poly(ethylene glycol) (PEG) and carboxylated PEG simultaneously and then functionalized with diethylenetriaminepentacetate acid for (99m)Tc coordination and subsequently Annexin V for targeting apoptotic macrophages abundant in vulnerable plaques. The in vivo accumulations of imaging probe reflected by SPECT and MRI were consistent and accurate in highlighting lesions. Intense radioactive signals detected by SPECT facilitated focus recognization and quantification, while USPIO-based T2-weighted MRI improved the focal localization and volumetry of AS plaques. For subsequent ex vivo planar images, targeting effects were further confirmed by immunohistochemistry, including CD-68 and TUNEL staining; meanwhile, the degree of concentration was proven to be statistically correlated with the Oil Red O staining results. In conclusion, these results indicated that the Annexin V-modified hybrid nanoparticle system specifically targeted the vulnerable AS plaques containing apoptotic macrophages and could be of great value in the invasively accurate detection of vulnerable plaques.

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

    PubMed Central

    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

  8. Analysis of Cardiovascular Tissue Components for the Diagnosis of Coronary Vulnerable Plaque from Intravascular Ultrasound Images

    PubMed Central

    Hwang, Yoo Na; Kim, Ga Young; Shin, Eun Seok

    2017-01-01

    The purpose of this study was to characterize cardiovascular tissue components and analyze the different tissue properties for predicting coronary vulnerable plaque from intravascular ultrasound (IVUS) images. For this purpose, sequential IVUS image frames were obtained from human coronary arteries using 20 MHz catheters. The plaque regions between the intima and media-adventitial borders were manually segmented in all IVUS images. Tissue components of the plaque regions were classified into having fibrous tissue (FT), fibrofatty tissue (FFT), necrotic core (NC), or dense calcium (DC). The media area and lumen diameter were also estimated simultaneously. In addition, the external elastic membrane (EEM) was computed to predict the vulnerable plaque after the tissue characterization. The reliability of manual segmentation was validated in terms of inter- and intraobserver agreements. The quantitative results found that the FT and the media as well as the NC would be good indicators for predicting vulnerable plaques in IVUS images. In addition, the lumen was not suitable for early diagnosis of vulnerable plaque because of the low significance compared to the other vessel parameters. To predict vulnerable plaque rupture, future study should have additional experiments using various tissue components, such as the EEM, FT, NC, and media.

  9. Chinese Herbal Cardiotonic Pill Stabilizes Vulnerable Plaques in Rabbits by Decreasing the Expression of Adhesion Molecules

    PubMed Central

    Chen, Liang; Li, Xiaonan; Li, Changjiang; Rong, Yuanyuan; Xiao, Yawei; Xu, Xinsheng; Yao, Guihua; Jiang, Guihua

    2016-01-01

    Abstract: The cardiotonic pill (CP), consisting of a mixture of Radix Salviae Miltiorrhizae, Radix Notoginseng, and Borneolum Syntheticum, has been widely used in the prevention and treatment of cardiovascular disease. Adhesion molecules, including intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1, are involved in the development of vulnerable plaque. We investigated the effect of the CP in a rabbit model of vulnerable plaque established by local transfection with p53 gene. Compared with the control group, rabbits with vulnerable plaque showed a significantly lower intima-media thickness and plaque burden after CP treatment for 12 weeks. Moreover, the reduction in rate of plaque rupture and vulnerability index was similar. On enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and immunohistochemistry analysis, the expression of intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 was inhibited with CP treatment. CP treatment could postpone atherosclerotic plaque development and stabilize vulnerable plaque by inhibiting the expression of adhesion molecules in treatment of cardiovascular disease. PMID:27110743

  10. The vulnerable plaque: current concepts and future perspectives on coronary morphology, composition and wall stress imaging.

    PubMed

    Silva Marques, João; Pinto, Fausto J

    2014-02-01

    Cardiovascular imaging plays an important role in the identification and characterization of the vulnerable plaque. A major goal is the ability to identify individuals at risk of plaque rupture and developing an acute coronary syndrome. Early recognition of rupture-prone atherosclerotic plaques may lead to the development of pharmacologic and interventional strategies to reduce acute coronary events. We review state-of-the-art cardiovascular imaging for identification of the vulnerable plaque. There is ample evidence of a close relationship between plaque morphology and patient outcome, but molecular imaging can add significant information on tissue characterization, inflammation and subclinical thrombosis. Additionally, identifying arterial wall exposed to high shear stress may further identify rupture-prone arterial segments. These new modalities may help reduce the individual, social and economic burden of cardiovascular disease.

  11. Vulnerable atherosclerotic plaque elasticity reconstruction based on a segmentation-driven optimization procedure using strain measurements: theoretical framework.

    PubMed

    Le Floc'h, Simon; Ohayon, Jacques; Tracqui, Philippe; Finet, Gérard; Gharib, Ahmed M; Maurice, Roch L; Cloutier, Guy; Pettigrew, Roderic I

    2009-07-01

    It is now recognized that prediction of the vulnerable coronary plaque rupture requires not only an accurate quantification of fibrous cap thickness and necrotic core morphology but also a precise knowledge of the mechanical properties of plaque components. Indeed, such knowledge would allow a precise evaluation of the peak cap-stress amplitude, which is known to be a good biomechanical predictor of plaque rupture. Several studies have been performed to reconstruct a Young's modulus map from strain elastograms. It seems that the main issue for improving such methods does not rely on the optimization algorithm itself, but rather on preconditioning requiring the best estimation of the plaque components' contours. The present theoretical study was therefore designed to develop: 1) a preconditioning model to extract the plaque morphology in order to initiate the optimization process, and 2) an approach combining a dynamic segmentation method with an optimization procedure to highlight the modulogram of the atherosclerotic plaque. This methodology, based on the continuum mechanics theory prescribing the strain field, was successfully applied to seven intravascular ultrasound coronary lesion morphologies. The reconstructed cap thickness, necrotic core area, calcium area, and the Young's moduli of the calcium, necrotic core, and fibrosis were obtained with mean relative errors of 12%, 4% and 1%, 43%, 32%, and 2%, respectively.

  12. Vulnerable Atherosclerotic Plaque Elasticity Reconstruction Based on a Segmentation-Driven Optimization Procedure Using Strain Measurements: Theoretical Framework

    PubMed Central

    Le Floc’h, Simon; Tracqui, Philippe; Finet, Gérard; Gharib, Ahmed M.; Maurice, Roch L.; Cloutier, Guy; Pettigrew, Roderic I.

    2016-01-01

    It is now recognized that prediction of the vulnerable coronary plaque rupture requires not only an accurate quantification of fibrous cap thickness and necrotic core morphology but also a precise knowledge of the mechanical properties of plaque components. Indeed, such knowledge would allow a precise evaluation of the peak cap-stress amplitude, which is known to be a good biomechanical predictor of plaque rupture. Several studies have been performed to reconstruct a Young’s modulus map from strain elastograms. It seems that the main issue for improving such methods does not rely on the optimization algorithm itself, but rather on preconditioning requiring the best estimation of the plaque components’ contours. The present theoretical study was therefore designed to develop: 1) a preconditioning model to extract the plaque morphology in order to initiate the optimization process, and 2) an approach combining a dynamic segmentation method with an optimization procedure to highlight the modulogram of the atherosclerotic plaque. This methodology, based on the continuum mechanics theory prescribing the strain field, was successfully applied to seven intravascular ultrasound coronary lesion morphologies. The reconstructed cap thickness, necrotic core area, calcium area, and the Young’s moduli of the calcium, necrotic core, and fibrosis were obtained with mean relative errors of 12%, 4% and 1%, 43%, 32%, and 2%, respectively. PMID:19164080

  13. The Spatial Distribution of Plaque Vulnerabilities in Patients with Acute Myocardial Infarction

    PubMed Central

    Zheng, Guian; Li, Yuxin; Takayama, Tadateru; Nishida, Toshihiko; Sudo, Mitsumasa; Haruta, Hironori; Fukamachi, Daisuke; Okubo, Kimie; Higuchi, Yoshiharu; Hiro, Takafumi; Saito, Satoshi; Hirayama, Atsushi

    2016-01-01

    Objective Although the plaque characteristics have been recognized in patients with acute myocardial infarction (AMI), the plaque spatial distribution is not well clarified. Using color-mapping intravascular ultrasound (iMAP-IVUS), we examined culprit lesions to clarify plaque morphology, composition and spatial distribution of the sites of potential vulnerability. Methods Sixty-eight culprit lesions in 64 consecutive AMI patients who underwent angiography and IVUS examinations before intervention were analyzed. Plaque morphology and composition were quantified with iMAP-IVUS. The spatial distribution of the sites of potential vulnerability was assessed with longitudinal reconstruction of the consecutive IVUS images. The plaque characteristics were also compared between ruptured and non-ruptured lesions, and between totally occlusive (TO) and non-TO lesions. Results The sites with maximum necrotic area (maxNA), maximum plaque burden (maxPB) and most severely narrowed (minimal luminal area, MLA) were recognized vulnerability. In the majority of cases, maxNA sites were proximal to the maxPB sites, and MLA sites were distal to the maxNA and maxPB sites. Ruptures usually occurred close to maxNA sites and proximal to maxPB and MLA sites. The average distance from the site of rupture to the maxNA site was 0.33 ± 4.04 mm. Ruptured lesions showed significant vessel remodeling, greater plaque volume, and greater lipidic volume compared to those of non-ruptured lesions. Both the length and plaque burden (PB) of TO lesions were greater than those of non-TO lesions. Conclusions Instead of overlapping on maxPB sites, most maxNA sites are proximal to the maxPB sites and are the sites most likely to rupture. Plaque morphology and composition play critical roles in plaque rupture and coronary occlusion. PMID:27031514

  14. A rapid, simple, and accurate plaque assay for human respiratory syncytial virus (HRSV).

    PubMed

    Kim, Kyung Sook; Kim, Ah Ra; Piao, Ying; Lee, Ju-Hie; Quan, Fu-Shi

    2017-03-31

    Plaque assays of human respiratory syncytial virus (HRSV) are time-consuming, requiring 4 to 7 days for plaque formation and several hours for dye staining. Here, we describe a simple method by which RSV plaques can be visualized and counted with the naked eye only 2 days after infection of HEp-2 cells. In this assay, the infected cells are stained with monoclonal antibodies and the plaques are developed using diaminobenzidine (DAB). We tested the accuracy of this new plaque assay by comparing the results obtained on days 1, 2, 3, 4, 5, and 6 post-infection. The whole procedure is significantly simpler than the traditional method, with an immunostaining process of around 1.5h. Our method is rapid, accurate, and simple; thus, it has the potential to significantly contribute to studies related to RSV disease.

  15. The role of near-infrared spectroscopy in the detection of vulnerable atherosclerotic plaques

    PubMed Central

    Hajek, Petr; Stechovsky, Cyril; Honek, Jakub; Spacek, Miloslav; Veselka, Josef

    2016-01-01

    Coronary artery disease is the leading cause of mortality worldwide. Most acute coronary syndromes are caused by a rupture of a vulnerable atherosclerotic plaque which can be characterized by a lipid-rich necrotic core with an overlying thin fibrous cap. Many vulnerable plaques can cause angiographically mild stenoses due to positive remodelling, which is why the extent of coronary artery disease may be seriously underestimated. In recent years, we have witnessed a paradigm shift in interventional cardiology. We no longer focus solely on the degree of stenosis; rather, we seek to determine the true extent of atherosclerotic disease. We seek to identify high-risk plaques for improvement in risk stratification of patients and prevention. Several imaging methods have been developed for this purpose. Intracoronary near-infrared spectroscopy is one of the most promising. Here, we discuss the possible applications of this diagnostic method and provide a comprehensive overview of the current knowledge. PMID:27904523

  16. Vulnerable atherosclerotic carotid plaque evaluation by ultrasound, computed tomography angiography, and magnetic resonance imaging: an overview.

    PubMed

    Naim, Cyrille; Douziech, Maxime; Therasse, Eric; Robillard, Pierre; Giroux, Marie-France; Arsenault, Frederic; Cloutier, Guy; Soulez, Gilles

    2014-08-01

    Ischemic syndromes associated with carotid atherosclerotic disease are often related to plaque rupture. The benefit of endarterectomy for high-grade carotid stenosis in symptomatic patients has been established. However, in asymptomatic patients, the benefit of endarterectomy remains equivocal. Current research seeks to risk stratify asymptomatic patients by characterizing vulnerable, rupture-prone atherosclerotic plaques. Plaque composition, biology, and biomechanics are studied by noninvasive imaging techniques such as magnetic resonance imaging, computed tomography, ultrasound, and ultrasound elastography. These techniques are at a developmental stage and have yet to be used in clinical practice. This review will describe noninvasive techniques in ultrasound, magnetic resonance imaging, and computed tomography imaging modalities used to characterize atherosclerotic plaque, and will discuss their potential clinical applications, benefits, and drawbacks.

  17. Machine learning techniques as a helpful tool toward determination of plaque vulnerability.

    PubMed

    Cilla, Myriam; Martínez, Javier; Peña, Estefanía; Martínez, Miguel Ángel

    2012-04-01

    Atherosclerotic cardiovascular disease results in millions of sudden deaths annually, and coronary artery disease accounts for the majority of this toll. Plaque rupture plays main role in the majority of acute coronary syndromes. Rupture has been usually associated with stress concentrations, which are determined mainly by tissue properties and plaque geometry. The aim of this study is develop a tool, using machine learning techniques to assist the clinical professionals on decisions of the vulnerability of the atheroma plaque. In practice, the main drawbacks of 3-D finite element analysis to predict the vulnerability risk are the huge main memories required and the long computation times. Therefore, it is essential to use these methods which are faster and more efficient. This paper discusses two potential applications of computational technologies, artificial neural networks and support vector machines, used to assess the role of maximum principal stress in a coronary vessel with atheroma plaque as a function of the main geometrical features in order to quantify the vulnerability risk.

  18. Plaque Vulnerability as Assessed by Radiofrequency Intravascular Ultrasound in Patients with Valvular Calcification

    PubMed Central

    Senguttuvan, Nagendra Boopathy; Kumar, Sharath; Mishra, Sundeep; Cho, Jun Hwan; Kwon, Jee Eun; Hyeon, Seong Hyeop; Jeong, Yun Sang; Won, Hoyoun; Shin, Seung Yong; Lee, Kwang Je; Kim, Tae Ho; Kim, Chee Jeong; Kim, Sang-Wook

    2016-01-01

    Background Cardiac valvular calcification is associated with the overall coronary plaque burden and considered an independent cardiovascular risk and prognostic factor. The purpose of this study was to evaluate the relationship between the presence of valvular calcification and plaque morphology and/or vulnerability. Methods Transthoracic echocardiography was used to assess valvular calcification in 280 patients with coronary artery disease who underwent radiofrequency intravascular ultrasound (Virtual Histology IVUS, VH-IVUS). A propensity score–matched cohort of 192 patients (n = 96 in each group) was analyzed. Thin-capped fibroatheroma (TCFA) was defined as a necrotic core (NC) >10% of the plaque area with a plaque burden >40% and NC in contact with the lumen for ≥3 image slices. A remodeling index (lesion/reference vessel area) >1.05 was considered to be positive. Results Patients were divided into two groups: any calcification in at least one valve (152 patients) vs. no detectable valvular calcification (128 patients). Groups were similar in terms of age, risk factors, clinical diagnosis, and angiographic analysis after propensity score-matched analysis. Gray-scale IVUS analysis showed that the vessel size, plaque burden, minimal lumen area, and remodeling index were similar. By VH-IVUS, % NC and % dense calcium (DC) were greater in patients with valvular calcification (p = 0.024, and p = 0.016, respectively). However, only % DC was higher at the maximal NC site by propensity score-matched analysis (p = 0.029). The frequency of VH-TCFA occurrence was higher depending on the complexity (p = 0.0064) and severity (p = 0.013) of valvular calcification. Conclusions There is a significant relationship between valvular calcifications and VH-IVUS assessment of TCFAs. Valvular calcification indicates a greater atherosclerosis disease complexity (increased calcification of the coronary plaque) and vulnerable coronary plaques (higher incidence of VH-TCFA). PMID

  19. Relationship of MMP-14 and TIMP-3 Expression with Macrophage Activation and Human Atherosclerotic Plaque Vulnerability

    PubMed Central

    Johnson, Jason L.; Jenkins, Nicholas P.; Huang, Wei-Chun; Sala-Newby, Graciela B.; Scholtes, Vincent P. W.; Moll, Frans L.; Pasterkamp, Gerard; Newby, Andrew C.

    2014-01-01

    Matrix metalloproteinase-14 (MMP-14) promotes vulnerable plaque morphology in mice, whereas tissue inhibitor of metalloproteinases-3 (TIMP-3) overexpression is protective. MMP-14hi  TIMP-3lo rabbit foam cells are more invasive and more prone to apoptosis than MMP-14lo  TIMP-3hi cells. We investigated the implications of these findings for human atherosclerosis. In vitro generated macrophages and foam-cell macrophages, together with atherosclerotic plaques characterised as unstable or stable, were examined for expression of MMP-14, TIMP-3, and inflammatory markers. Proinflammatory stimuli increased MMP-14 and decreased TIMP-3 mRNA and protein expression in human macrophages. However, conversion to foam-cells with oxidized LDL increased MMP-14 and decreased TIMP-3 protein, independently of inflammatory mediators and partly through posttranscriptional mechanisms. Within atherosclerotic plaques, MMP-14 was prominent in foam-cells with either pro- or anti-inflammatory macrophage markers, whereas TIMP-3 was present in less foamy macrophages and colocalised with CD206. MMP-14 positive macrophages were more abundant whereas TIMP-3 positive macrophages were less abundant in plaques histologically designated as rupture prone. We conclude that foam-cells characterised by high MMP-14 and low TIMP-3 expression are prevalent in rupture-prone atherosclerotic plaques, independent of pro- or anti-inflammatory activation. Therefore reducing MMP-14 activity and increasing that of TIMP-3 could be valid therapeutic approaches to reduce plaque rupture and myocardial infarction. PMID:25301980

  20. Mesenchymal Stem Cells Stabilize Atherosclerotic Vulnerable Plaque by Anti-Inflammatory Properties

    PubMed Central

    Wang, Shuang-shuang; Hu, Si-wang; Zhang, Qing-hua; Xia, Ai-xiang

    2015-01-01

    Background and objectives Formation and progression of atherosclerotic vulnerable plaque (VP) is the primary cause of many cardio-cerebrovascular diseases such as acute coronary syndrome and stroke. It has been reported that bone marrow mesenchymal stem cells (MSC) exhibit protective effects against many kinds of diseases including myocardial infarction. Here, we examined the effects of intravenous MSC infusion on a VP model and provide novel evidence of its influence as a therapy in this animal disease model. Subjects and methods Thirty healthy male New Zealand white rabbits were randomly divided into a MSC, VP or stable plaque (SP) group (n = 10/group) and received high fat diet and cold-induced common carotid artery intimal injury with liquid nitrogen to form atherosclerotic plaques. Serum hs-CRP, TNF-α, IL-6 and IL-10 levels were measured by ELISA at 1, 2, 3, 7, 14, 21 and 28 days after MSC transplantation. The animals were sacrificed at 4 weeks after MSC transplantation. Lesions in the right common carotid were observed using H&E and Masson staining, and the fibrous cap/lipid core ratio of atherosclerotic plaques were calculated. The expression of nuclear factor κB (NF-κB) and matrix metalloproteinase 1, 2, 9 (MMP-1,2,9) in the plaque were detected using immunohistochemistry, and apoptotic cells in the plaques were detected by TUNEL. In addition, the level of TNF-α stimulated gene/protein 6 (TSG-6) mRNA and protein were measured by quantitative Real-Time PCR and Western blotting, respectively. Results Two rabbits in the VP group died of lung infection and cerebral infarction respectively at 1 week after plaque injury by liquid nitrogen. Both H&E and Masson staining revealed that the plaques from the SP and MSC groups had more stable morphological structure and a larger fibrous cap/lipid core ratio than the VP group. Serum hs-CRP, TNF-α and IL-6 were significantly down-regulated, whereas IL-10 was significantly up-regulated in the MSC group compared with

  1. Chronic intermittent mental stress promotes atherosclerotic plaque vulnerability, myocardial infarction and sudden death in mice.

    PubMed

    Roth, Lynn; Rombouts, Miche; Schrijvers, Dorien M; Lemmens, Katrien; De Keulenaer, Gilles W; Martinet, Wim; De Meyer, Guido R Y

    2015-09-01

    Vulnerable atherosclerotic plaques are prone to plaque rupture leading to acute cardiovascular syndromes and death. Elucidating the risk of plaque rupture is important to define better therapeutic or preventive strategies. In the present study, we investigated the effect of chronic intermittent mental stress on atherosclerotic plaque stability and cardiovascular mortality in apolipoprotein E-deficient (ApoE(-/-)) mice with a heterozygous mutation in the fibrillin-1 gene (Fbn1(C1039G+/)(-)). This mouse model displays exacerbated atherosclerosis with spontaneous plaque ruptures, myocardial infarction and sudden death, when fed a Western-type diet (WD). Female ApoE(-/-)Fbn1(C1039G+/-) mice were fed a WD for up to 25 weeks. After 10 weeks WD, mice were divided in a control (n = 27) and mental stress (n = 29) group. The chronic intermittent mental stress protocol consisted of 3 triggers: water avoidance, damp bedding and restraint stress, in a randomly assigned order lasting 6 h every weekday for 15 weeks. Chronic intermittent mental stress resulted in a significant increase in the amount of macrophages in atherosclerotic plaques of the proximal ascending aorta, whereas type I collagen and fibrous cap thickness were decreased. The coronary arteries of mental stress-treated mice showed larger plaques, more stenosis, and an increased degree of perivascular fibrosis. Moreover, myocardial infarctions occurred more frequently in the mental stress group. As compared to the control group, the survival of stressed ApoE(-/-)Fbn1(C1039G+/-) mice decreased from 67% to 52% at 25 weeks WD, presumably due to myocardial infarctions. In conclusion, chronic intermittent mental stress promotes plaque instability, myocardial infarctions, and mortality of ApoE(-/-)Fbn1(C1039G+/-) mice.

  2. Plaque and arterial vulnerability investigation in a three-layer atherosclerotic human coronary artery using computational fluid-structure interaction method

    NASA Astrophysics Data System (ADS)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

    2014-08-01

    Coronary artery disease is the common form of cardiovascular diseases and known to be the main reason of deaths in the world. Fluid-Structure Interaction (FSI) simulations can be employed to assess the interactions of artery/plaque and blood to provide a more precise anticipation for rupture of arterial tissue layers and plaque tissues inside an atherosclerotic artery. To date, the arterial tissue in computational FSI simulations has been considered as a one-layer structure. However, a single layer assumption might have deeply bounded the results and, consequently, more computational simulation is needed by considering the arterial tissue as a three-layer structure. In this study, a three-dimensional computational FSI model of an atherosclerotic artery with a three-layer structure and different plaque types was established to perform a more accurate arterial wall/plaque tissue vulnerability assessment. The hyperelastic material coefficients of arterial layers were calculated and implemented in the computational model. The fully coupled fluid and structure models were solved using the explicit dynamics finite element code LS-DYNA. The results revealed the significant role of plaque types in the normal and shear stresses induced within the arterial tissue layers. The highest von Mises and shear stresses were observed on the stiffest calcified plaque with 3.59 and 3.27 MPa, while the lowest von Mises and shear stresses were seen on the hypocellular plaque with 1.15 and 0.63 MPa, respectively. Regardless of plaque types, the media and adventitia layers were played protective roles by displaying less stress on their wall, whilst the intima layer was at a high risk of rupture. The findings of this study have implications not only for determining the most vulnerable arterial layer/plaque tissue inside an atherosclerotic coronary artery but also for balloon-angioplasty, stenting, and bypass surgeries.

  3. Vulnerable Plaque

    MedlinePlus

    ... Kawasaki Disease Long Q-T Syndrome Marfan Syndrome Metabolic Syndrome Mitral Valve Prolapse Myocardial Bridge Myocarditis Obstructive Sleep Apnea Pericarditis Peripheral Vascular Disease Rheumatic Fever Sick Sinus Syndrome Silent Ischemia Stroke Sudden ...

  4. Requirements for imaging vulnerable plaque in the coronary artery using a coded aperture imaging system

    NASA Astrophysics Data System (ADS)

    Tozian, Cynthia

    A coded aperture1 plate was employed on a conventional gamma camera for 3D single photon emission computed tomography (SPECT) imaging on small animal models. The coded aperture design was selected to improve the spatial resolution and decrease the minimum detectable activity (MDA) required to image plaque formation in the APoE (apolipoprotein E) gene deficient mouse model when compared to conventional SPECT techniques. The pattern that was tested was a no-two-holes-touching (NTHT) modified uniformly redundant array (MURA) having 1,920 pinholes. The number of pinholes combined with the thin sintered tungsten plate was designed to increase the efficiency of the imaging modality over conventional gamma camera imaging methods while improving spatial resolution and reducing noise in the image reconstruction. The MDA required to image the vulnerable plaque in a human cardiac-torso mathematical phantom was simulated with a Monte Carlo code and evaluated to determine the optimum plate thickness by a receiver operating characteristic (ROC) yielding the lowest possible MDA and highest area under the curve (AUC). A partial 3D expectation maximization (EM) reconstruction was developed to improve signal-to-noise ratio (SNR), dynamic range, and spatial resolution over the linear correlation method of reconstruction. This improvement was evaluated by imaging a mini hot rod phantom, simulating the dynamic range, and by performing a bone scan of the C-57 control mouse. Results of the experimental and simulated data as well as other plate designs were analyzed for use as a small animal and potentially human cardiac imaging modality for a radiopharmaceutical developed at Bristol-Myers Squibb Medical Imaging Company, North Billerica, MA, for diagnosing vulnerable plaques. If left untreated, these plaques may rupture causing sudden, unexpected coronary occlusion and death. The results of this research indicated that imaging and reconstructing with this new partial 3D algorithm improved

  5. Positron emission tomography of the vulnerable atherosclerotic plaque in man – a contemporary review

    PubMed Central

    Pedersen, Sune F; Hag, Anne Mette F; Klausen, Thomas L; Ripa, Rasmus S; Bodholdt, Rasmus P; Kjær, Andreas

    2014-01-01

    Atherosclerosis is the primary underlying cause of cardiovascular disease (CVD). It is the leading cause of morbidity and mortality in the Western world today and is set to become the prevailing disease and major cause of death worldwide by 2020. In the 1950s surgical intervention was introduced to treat symptomatic patients with high-grade carotid artery stenosis due to atherosclerosis – a procedure known as carotid endarterectomy (CEA). By removing the atherosclerotic plaque from the affected carotid artery of these patients, CEA is beneficial by preventing subsequent ipsilateral ischemic stroke. However, it is known that patients with low to intermediate artery stenosis may still experience ischemic events, leading clinicians to consider plaque composition as an important feature of atherosclerosis. Today molecular imaging can be used for characterization, visualization and quantification of cellular and subcellular physiological processes as they take place in vivo; using this technology we can obtain valuable information on atherosclerostic plaque composition. Applying molecular imaging clinically to atherosclerotic disease therefore has the potential to identify atherosclerotic plaques vulnerable to rupture. This could prove to be an important tool for the selection of patients for CEA surgery in a health system increasingly focused on individualized treatment. This review focuses on current advances and future developments of in vivo atherosclerosis PET imaging in man. PMID:24289282

  6. A Review of Intravascular Ultrasound–Based Multimodal Intravascular Imaging: The Synergistic Approach to Characterizing Vulnerable Plaques

    PubMed Central

    Ma, Teng; Zhou, Bill; Hsiai, Tzung K.; Shung, K. Kirk

    2015-01-01

    Catheter-based intravascular imaging modalities are being developed to visualize pathologies in coronary arteries, such as high-risk vulnerable atherosclerotic plaques known as thin-cap fibroatheroma, to guide therapeutic strategy at preventing heart attacks. Mounting evidences have shown three distinctive histopathological features—the presence of a thin fibrous cap, a lipid-rich necrotic core, and numerous infiltrating macrophages—are key markers of increased vulnerability in atherosclerotic plaques. To visualize these changes, the majority of catheter-based imaging modalities used intravascular ultrasound (IVUS) as the technical foundation and integrated emerging intravascular imaging techniques to enhance the characterization of vulnerable plaques. However, no current imaging technology is the unequivocal “gold standard” for the diagnosis of vulnerable atherosclerotic plaques. Each intravascular imaging technology possesses its own unique features that yield valuable information although encumbered by inherent limitations not seen in other modalities. In this context, the aim of this review is to discuss current scientific innovations, technical challenges, and prospective strategies in the development of IVUS-based multi-modality intravascular imaging systems aimed at assessing atherosclerotic plaque vulnerability. PMID:26400676

  7. Changing views of the biomechanics of vulnerable plaque rupture: a review.

    PubMed

    Cardoso, Luis; Weinbaum, Sheldon

    2014-02-01

    This review examines changing perspectives on the biomechanics of vulnerable plaque rupture over the past 25 years from the first finite element analyses (FEA) showing that the presence of a lipid pool significantly increases the local tissue stress in the atheroma cap to the latest imaging and 3D FEA studies revealing numerous microcalcifications in the cap proper and a new paradigm for cap rupture. The first part of the review summarizes studies describing the role of the fibrous cap thickness, tissue properties, and lesion geometry as main determinants of the risk of rupture. Advantages and limitations of current imaging technologies for assessment of vulnerable plaques are also discussed. However, the basic paradoxes as to why ruptures frequently did not coincide with location of PCS and why caps >65 μm thickness could rupture at tissue stresses significantly below the 300 kPa critical threshold still remained unresolved. The second part of the review describes recent studies in the role of microcalcifications, their origin, shape, and clustering in explaining these unresolved issues including the actual mechanism of rupture due to the explosive growth of tiny voids (cavitation) in local regions of high stress concentration between closely spaced microinclusions oriented along their tensile axis.

  8. Relation of microchannel structure identified by optical coherence tomography to plaque vulnerability in patients with coronary artery disease.

    PubMed

    Kitabata, Hironori; Tanaka, Atsushi; Kubo, Takashi; Takarada, Shigeho; Kashiwagi, Manabu; Tsujioka, Hiroto; Ikejima, Hideyuki; Kuroi, Akio; Kataiwa, Hideaki; Ishibashi, Kohei; Komukai, Kenichi; Tanimoto, Takashi; Ino, Yasushi; Hirata, Kumiko; Nakamura, Nobuo; Mizukoshi, Masato; Imanishi, Toshio; Akasaka, Takashi

    2010-06-15

    Increased neovascularization in atherosclerotic plaques is associated with plaque vulnerability. The high resolution of optical coherence tomography (OCT) might provide a chance to directly visualize plaque neovascularization in vivo. The aim of the present study was to investigate the relation between microchannels in culprit plaques identified by OCT and plaque vulnerability in patients with coronary artery disease. A total of 63 consecutive patients with coronary artery disease who had undergone both OCT and intravascular ultrasound before any interventions to examine culprit lesion morphologies were enrolled. Microchannel was defined as a no-signal tubuloluminal structure on the cross-sectional optical coherence tomographic image. Microchannels were found in 24 (38%) of the 63 patients. The patients were divided into 2 groups according to the presence or absence of microchannels. The frequency of plaque rupture tended to be greater in the microchannel group (50% vs 28%, p = 0.11). The thickness of the fibrous cap (median 60 vs 100 microm, p = 0.001) was significantly less in the patients with microchannels, and significant differences were found in the frequency of thin-cap fibroatheroma (54% vs 21%, p = 0.012) and positive remodeling (67% vs 36%, p = 0.02) between the 2 groups. The high-sensitivity C-reactive protein levels in the microchannel group was significantly greater than those in the no-microchannel group (median 0.27 vs 0.13 mg/dl, p = 0.015). Moreover, increased microchannel counts were associated with greater high-sensitivity C-reactive protein levels (p = 0.01). In conclusion, a significant relation was found between the presence of microchannels in plaques identified by OCT and plaque vulnerability in patients with coronary artery disease.

  9. Circulating CD36 and fractalkine levels are associated with vulnerable plaque progression in patients with unstable angina pectoris.

    PubMed

    Li, Rui Jian; Yang, Ming; Li, Ji Fu; Xue, Li; Chen, Yu Guo; Chen, Wen Qiang

    2014-11-01

    The chemokine, fractalkine, independently enhances the vulnerability of coronary atherosclerotic plaques. The present study investigated the combined effects of CD36 and fractalkine on coronary plaque progression in patients with unstable angina pectoris. In the present study, 120 unstable angina pectoris patients undergoing coronary angiography and intravascular ultrasound were divided into two groups: an intermediate lesion group (lumen diameter stenosis 50-70%, 80 patients) and a severe lesion group (at least one lesion with lumen diameter stenosis > 70%, 40 patients). The control group consisted of 40 healthy age- and sex-matched subjects. Concentrations of CD36 and fractalkine were measured by enzyme-linked immunosorbent assay. Major adverse cardiovascular events were monitored over a 2-year follow up. Intravascular ultrasound showed that patients with severe lesions had more calcified and mixed plaques, and a larger plaque area and plaque burden than patients with intermediate lesions (P < 0.05-0.01). More patients with severe lesions underwent stent deployment (P < 0.05) than those with intermediate lesions. CD36 and fractalkine concentrations were significantly higher in the severe lesion patients (P < 0.05), and both had significant positive correlations (P < 0.05) with the plaque burden of atherosclerotic lesions. Using the matched nested case-control study, we found that CD36 and fractalkine levels were higher in patients with recurrent major adverse cardiovascular events than controls (P < 0.05). In conclusion, CD36 and fractalkine both promote, and might synergistically enhance, the progression of coronary atherosclerotic plaques.

  10. MiR-181b Antagonizes Atherosclerotic Plaque Vulnerability Through Modulating Macrophage Polarization by Directly Targeting Notch1.

    PubMed

    An, Tian-Hui; He, Quan-Wei; Xia, Yuan-Peng; Chen, Sheng-Cai; Baral, Suraj; Mao, Ling; Jin, Hui-Juan; Li, Ya-Nan; Wang, Meng-Die; Chen, Jian-Guo; Zhu, Ling-Qiang; Hu, Bo

    2016-10-08

    Atherosclerotic plaque vulnerability is the major cause for acute stroke and could be regulated by macrophage polarization. MicroRNA-181b (miR-181b) was involved in macrophage differential. Here, we explore whether miR-181b could regulate atherosclerotic plaque vulnerability by modulating macrophage polarization and the underline mechanisms. In acute stroke patients with atherosclerotic plaque, we found that the serum level of miR-181b was decreased. Eight-week apolipoprotein E knockout (ApoE(-/-)) mice were randomly divided into three groups (N = 10): mice fed with normal saline (Ctrl), mice fed with high-fat diet, and tail vein injection with miRNA agomir negative control (AG-NC)/miR-181b agomir (181b-AG, a synthetic miR-181b agonist). We found that the serum level of miR-181b in AG-NC group was lower than that in Ctrl group. Moreover, 181b-AG could upregulate miR-181b expression, reduce artery burden and attenuate atherosclerotic plaque vulnerability by modulating macrophage polarization. In RAW264.7 cells treated with oxidized low-density lipoprotein (ox-LDL), we found miR-181b could reverse the function of ox-LDL on M1/M2 markers at both mRNA and protein levels. Furthermore, by employing luciferase reporter assay, we found that Notch1 was a direct target of miR-181b and could be regulated by miR-181b in vivo and in vitro. Finally, inhibition of Notch1 could abolish the function of downregulating miR-181b on increasing M2 phenotype macrophages. Our study demonstrates that administration of miR-181b could reduce atherosclerotic plaque vulnerability partially through modulating macrophage phenotype by directly targeting Notch1.

  11. A finite element study of balloon expandable stent for plaque and arterial wall vulnerability assessment

    NASA Astrophysics Data System (ADS)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

    2014-07-01

    The stresses induced within plaque tissues and arterial layers during stent expansion inside an atherosclerotic artery can be exceeded from the yield stresses of those tissues and, consequently, lead to plaque or arterial layer rupture. The distribution and magnitude of the stresses in each component involved in stenting might be clearly different for different plaque types and different arterial layers. In this study, a nonlinear finite element simulation was employed to investigate the effect of plaque composition (calcified, cellular, and hypocellular) on the stresses induced in the arterial layers (intima, media, and adventitia) during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal/healthy arterial tissues on its outer side. The results indicated a significant influence of plaque types on the maximum stresses induced within the plaque wall and arterial layers during stenting but not when computing maximum stress on the stent. The stress on the stiffest calcified plaque wall was in the fracture level (2.38 MPa), whereas cellular and hypocellular plaques remain stable owing to less stress on their walls. Regardless of plaque types, the highest von Mises stresses were observed on the stiffest intima layer, whereas the lowest stresses were seen to be located in less stiff media layer. The computed stresses on the intima layer were found to be high enough to initiate a rupture in this stiff layer. These findings suggest a higher risk of arterial vascular injury for the intima layer, while a lower risk of arterial injury for the media and adventitia layers.

  12. Effects of insulin sensitizers on plaque vulnerability associated with elevated lipid content in atheroma in ApoE-knockout mice.

    PubMed

    Cefalu, W T; Wang, Z Q; Schneider, D J; Absher, P M; Baldor, L C; Taatjes, D J; Sobel, B E

    2004-03-01

    Acute coronary syndromes are generally precipitated by rupture of lipid-laden, relatively acellular, vulnerable atherosclerotic plaques with thin fibrous caps. We investigated whether a high-fat diet alters insulin sensitivity and whether insulin sensitizers (troglitazone and rosiglitazone) alter the composition of otherwise lipidladen atherosclerotic plaques in mice deficient in apolipoprotein E (ApoE). ApoE-knockout mice were fed a high-fat (n=30) or standard chow (n=10) diet for two weeks. Thereafter, those fed the high-fat diet were treated with troglitazone (n=10), rosiglitazone (n=10) or no drug (n=10) for 16 weeks beginning at 8 weeks of age. Carbohydrate metabolism was assessed with intraperitoneal glucose tolerance tests and insulin tolerance tests. Plaque composition was characterised with confocal laser scanning microscopy. The high-fat diet induced insulin resistance in the absence of weight gain. Compared with control animals on the high-fat diet, animals given troglitazone (400 mg/kg/day) or rosiglitazone (4 mg/kg/day) had significantly less area under the curve (AUC) for insulin ( p<0.05) and glucose disposal ( p<0.05). Despite significant increases in insulin sensitivity with drug treatment, no change in HDL-cholesterol and triglyceride levels, nor reduction in atheroma size or lipid content was noted. Thus, improvement in insulin resistance induced by a high-fat diet in this animal model of vasculopathy did not alter plaque composition.

  13. In search of the "vulnerable plaque": can it be localized and will focal regional therapy ever be an option for cardiac prevention?

    PubMed

    Ambrose, John A

    2008-04-22

    The search to find the location of future plaque ruptures or plaque erosions leading to myocardial infarction (so-called "vulnerable plaques") is an important area of cardiovascular research. Systemic therapy, including use of statins, targets the vulnerable patient. However, adverse events cannot be completely eliminated with the appropriate application of systemic therapies and thus has given rise to the possibility of local or regional therapy of "vulnerable plaques" to prevent future events. Until now, no criteria have been developed for consideration of this therapy. For such a strategy to work, there should be several prerequisites. These involve the identification of susceptible lesions, the number of lesions, their natural history, and proof that an interventional technique is preferable to medical therapy alone. The greatest deficiency relates to the fact that until the natural history of presumed "vulnerable plaques" is known one can never truly identify what constitutes a "vulnerable plaque." Much work needs to be done in this area, but ongoing and new trials should provide important information that could potentially change drastically how coronary artery disease is diagnosed and treated.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. The Immunologic Injury Composite with Balloon Injury Leads to Dyslipidemia: A Robust Rabbit Model of Human Atherosclerosis and Vulnerable Plaque

    PubMed Central

    Zhang, Guangyin; Li, Ming; Li, Liangjun; Xu, Yingzhi; Li, Peng; Yang, Cui; Zhou, Yanan; Zhang, Junping

    2012-01-01

    Atherosclerosis is a condition in which a lipid deposition, thrombus formation, immune cell infiltration, and a chronic inflammatory response, but its systemic study has been hampered by the lack of suitable animal models, especially in herbalism fields. We have tried to perform a perfect animal model that completely replicates the stages of human atherosclerosis. This is the first combined study about the immunologic injury and balloon injury based on the cholesterol diet. In this study, we developed a modified protocol of the white rabbit model that could represent a novel approach to studying human atherosclerosis and vulnerable plaque. PMID:22988422

  16. Elevated hemoglobin A1c Is Associated with Carotid Plaque Vulnerability: Novel Findings from Magnetic Resonance Imaging Study in Hypertensive Stroke Patients

    PubMed Central

    Sun, Beibei; Zhao, Huilin; Liu, Xiaosheng; Lu, Qing; Zhao, Xihai; Pu, Jun; Xu, Jianrong

    2016-01-01

    The association between hemoglobin A1c (HbA1c) level and carotid plaque vulnerability has been rarely studied by magnetic resonance imaging (MRI). The present study of MRI-identified carotid atherosclerotic lesions in hypertensive patients with acute stroke therefore sought to determine the associations between HbA1c level and plaque morphological and compositional characteristics and acute cerebral infarction (ACI) severity. Eighty hypertensive patients with acute stroke were enrolled; stratified into high (≥6.5%) and low (<6.5%) HbA1c groups; and underwent carotid and brain MRI to assess carotid plaque features and ACI volume in the region supplied by the internal carotid artery (ICA) in the symptomatic side. Plaque burden [percent wall volume (PWV), max wall thickness (max-WT)] and lipid-rich necrotic core (LRNC) were larger in the high as compared to the low HbA1c group. High HbA1c was an independent risk factor for the presence of plaque (odds ratio [OR] = 3.71) and LRNC plaque (OR = 7.08). HbA1c independently correlated with ACI severity among patients with ICA region cerebral infarction and carotid plaque. Our study suggested that an elevated HbA1c may have an adverse effect on carotid plaque vulnerability especially those with larger LRNC volumes in hypertensive stroke patients, which might exacerbate the severity of ACIs. PMID:27629481

  17. Preclinical models of atherosclerosis. The future of Hybrid PET/MR technology for the early detection of vulnerable plaque.

    PubMed

    Cuadrado, Irene; Saura, Marta; Castejón, Borja; Martin, Ana María; Herruzo, Irene; Balatsos, Nikolaos; Zamorano, Jose Luis; Zaragoza, Carlos

    2016-04-08

    Cardiovascular diseases are the leading cause of death in developed countries. The aetiology is currently multifactorial, thus making them very difficult to prevent. Preclinical models of atherothrombotic diseases, including vulnerable plaque-associated complications, are now providing significant insights into pathologies like atherosclerosis, and in combination with the most recent advances in new non-invasive imaging technologies, they have become essential tools to evaluate new therapeutic strategies, with which can forecast and prevent plaque rupture. Positron emission tomography (PET)/computed tomography imaging is currently used for plaque visualisation in clinical and pre-clinical cardiovascular research, albeit with significant limitations. However, the combination of PET and magnetic resonance imaging (MRI) technologies is still the best option available today, as combined PET/MRI scans provide simultaneous data acquisition together with high quality anatomical information, sensitivity and lower radiation exposure for the patient. The coming years may represent a new era for the implementation of PET/MRI in clinical practice, but first, clinically efficient attenuation correction algorithms and research towards multimodal reagents and safety issues should be validated at the preclinical level.

  18. Three-dimensional dynamic contrast-enhanced MRI for the accurate, extensive quantification of microvascular permeability in atherosclerotic plaques.

    PubMed

    Calcagno, Claudia; Lobatto, Mark E; Dyvorne, Hadrien; Robson, Philip M; Millon, Antoine; Senders, Max L; Lairez, Olivier; Ramachandran, Sarayu; Coolen, Bram F; Black, Alexandra; Mulder, Willem J M; Fayad, Zahi A

    2015-10-01

    Atherosclerotic plaques that cause stroke and myocardial infarction are characterized by increased microvascular permeability and inflammation. Dynamic contrast-enhanced MRI (DCE-MRI) has been proposed as a method to quantify vessel wall microvascular permeability in vivo. Until now, most DCE-MRI studies of atherosclerosis have been limited to two-dimensional (2D) multi-slice imaging. Although providing the high spatial resolution required to image the arterial vessel wall, these approaches do not allow the quantification of plaque permeability with extensive anatomical coverage, an essential feature when imaging heterogeneous diseases, such as atherosclerosis. To our knowledge, we present the first systematic evaluation of three-dimensional (3D), high-resolution, DCE-MRI for the extensive quantification of plaque permeability along an entire vascular bed, with validation in atherosclerotic rabbits. We compare two acquisitions: 3D turbo field echo (TFE) with motion-sensitized-driven equilibrium (MSDE) preparation and 3D turbo spin echo (TSE). We find 3D TFE DCE-MRI to be superior to 3D TSE DCE-MRI in terms of temporal stability metrics. Both sequences show good intra- and inter-observer reliability, and significant correlation with ex vivo permeability measurements by Evans Blue near-infrared fluorescence (NIRF). In addition, we explore the feasibility of using compressed sensing to accelerate 3D DCE-MRI of atherosclerosis, to improve its temporal resolution and therefore the accuracy of permeability quantification. Using retrospective under-sampling and reconstructions, we show that compressed sensing alone may allow the acceleration of 3D DCE-MRI by up to four-fold. We anticipate that the development of high-spatial-resolution 3D DCE-MRI with prospective compressed sensing acceleration may allow for the more accurate and extensive quantification of atherosclerotic plaque permeability along an entire vascular bed. We foresee that this approach may allow for

  19. A direct vulnerable atherosclerotic plaque elasticity reconstruction method based on an original material-finite element formulation: theoretical framework

    PubMed Central

    Bouvier, Adeline; Deleaval, Flavien; Doyley, Marvin M; Yazdani, Saami K; Finet, Gérard; Le Floc'h, Simon; Cloutier, Guy; Pettigrew, Roderic I; Ohayon, Jacques

    2016-01-01

    The peak cap stress (PCS) amplitude is recognized as a biomechanical predictor of vulnerable plaque (VP) rupture. However, quantifying PCS in vivo remains a challenge since the stress depends on the plaque mechanical properties. In response, an iterative material finite element (FE) elasticity reconstruction method using strain measurements has been implemented for the solution of these inverse problems. Although this approach could resolve the mechanical characterization of VPs, it suffers from major limitations since (i) it is not adapted to characterize VPs exhibiting high material discontinuities between inclusions, and (ii) does not permit real time elasticity reconstruction for clinical use. The present theoretical study was therefore designed to develop a direct material-FE algorithm for elasticity reconstruction problems which accounts for material heterogeneities. We originally modified and adapted the extended FE method (Xfem), used mainly in crack analysis, to model material heterogeneities. This new algorithm was successfully applied to six coronary lesions of patients imaged in vivo with intravascular ultrasound. The results demonstrated that the mean relative absolute errors of the reconstructed Young's moduli obtained for the arterial wall, fibrosis, necrotic core, and calcified regions of the VPs decreased from 95.3±15.56%, 98.85±72.42%, 103.29±111.86% and 95.3±10.49%, respectively, to values smaller than 2.6 × 10−8±5.7 × 10−8% (i.e. close to the exact solutions) when including modified-Xfem method into our direct elasticity reconstruction method. PMID:24240392

  20. A direct vulnerable atherosclerotic plaque elasticity reconstruction method based on an original material-finite element formulation: theoretical framework

    NASA Astrophysics Data System (ADS)

    Bouvier, Adeline; Deleaval, Flavien; Doyley, Marvin M.; Yazdani, Saami K.; Finet, Gérard; Le Floc'h, Simon; Cloutier, Guy; Pettigrew, Roderic I.; Ohayon, Jacques

    2013-12-01

    The peak cap stress (PCS) amplitude is recognized as a biomechanical predictor of vulnerable plaque (VP) rupture. However, quantifying PCS in vivo remains a challenge since the stress depends on the plaque mechanical properties. In response, an iterative material finite element (FE) elasticity reconstruction method using strain measurements has been implemented for the solution of these inverse problems. Although this approach could resolve the mechanical characterization of VPs, it suffers from major limitations since (i) it is not adapted to characterize VPs exhibiting high material discontinuities between inclusions, and (ii) does not permit real time elasticity reconstruction for clinical use. The present theoretical study was therefore designed to develop a direct material-FE algorithm for elasticity reconstruction problems which accounts for material heterogeneities. We originally modified and adapted the extended FE method (Xfem), used mainly in crack analysis, to model material heterogeneities. This new algorithm was successfully applied to six coronary lesions of patients imaged in vivo with intravascular ultrasound. The results demonstrated that the mean relative absolute errors of the reconstructed Young's moduli obtained for the arterial wall, fibrosis, necrotic core, and calcified regions of the VPs decreased from 95.3±15.56%, 98.85±72.42%, 103.29±111.86% and 95.3±10.49%, respectively, to values smaller than 2.6 × 10-8±5.7 × 10-8% (i.e. close to the exact solutions) when including modified-Xfem method into our direct elasticity reconstruction method.

  1. Tanshinone II A stabilizes vulnerable plaques by suppressing RAGE signaling and NF-κB activation in apolipoprotein-E-deficient mice

    PubMed Central

    Zhao, Dong; Tong, Lufang; Zhang, Lixin; Li, Hong; Wan, Yingxin; Zhang, Tiezhong

    2016-01-01

    Tanshinone II A (TSIIA) is a diterpene quinone extracted from the roots of Salvia miltiorrhiza with anti-inflammatory and anti-oxidant properties that is used to treat atherosclerosis. In the current study, morphological analyses were conducted to evaluate the effects of TSIIA on atherosclerotic vulnerable plaque stability. Additionally, receptor of advanced glycation end products (RAGE), adhesion molecule, and matrix-metalloproteinases (MMPs) expression, and nuclear factor-κB (NF-κB) activation were examined in apolipoprotein E (apoE)-deficient mice treated with TSIIA. Eight-week-old apoE−/− mice were administered TSIIA and fed an atherogenic diet for 8 weeks. TSIIA exhibited no effects on plaque size. Analysis of the vulnerable plaque composition demonstrated decreased numbers of macrophages and smooth muscle cells, and increased collagen content in apoE-deficient mice treated with TSIIA compared with untreated mice. Western blotting revealed that TSIIA downregulated the expression levels of vascular cellular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and MMP-2, −3, and −9, suppressed RAGE, and inhibited NF-κB, JNK and p38 activation. The present study demonstrated that the underlying mechanism of TSIIA stabilization of vulnerable plaques involves interfering with RAGE and NF-κB activation, and downregulation of downstream inflammatory factors, including ICAM-1, VCAM-1, and MMP-2, −3 and −9 in apoE−/− mice. PMID:27840935

  2. Arterial vulnerable plaque characterization using ultrasound-induced thermal strain imaging (TSI).

    PubMed

    Kim, Kang; Huang, Sheng-Wen; Hall, Timothy L; Witte, Russell S; Chenevert, Thomas L; O'Donnell, Matthew

    2008-01-01

    anatomy. These in vitro results demonstrate the potential of high-resolution US-induced TSI with a small temperature change (<1 degrees C) for plaque characterization.

  3. From vulnerable plaque to vulnerable patient--Part III: Executive summary of the Screening for Heart Attack Prevention and Education (SHAPE) Task Force report.

    PubMed

    Naghavi, Morteza; Falk, Erling; Hecht, Harvey S; Jamieson, Michael J; Kaul, Sanjay; Berman, Daniel; Fayad, Zahi; Budoff, Matthew J; Rumberger, John; Naqvi, Tasneem Z; Shaw, Leslee J; Faergeman, Ole; Cohn, Jay; Bahr, Raymond; Koenig, Wolfgang; Demirovic, Jasenka; Arking, Dan; Herrera, Victoria L M; Badimon, Juan; Goldstein, James A; Rudy, Yoram; Airaksinen, Juhani; Schwartz, Robert S; Riley, Ward A; Mendes, Robert A; Douglas, Pamela; Shah, Prediman K

    2006-07-17

    Screening for early-stage asymptomatic cancers (eg, cancers of breast and colon) to prevent late-stage malignancies has been widely accepted. However, although atherosclerotic cardiovascular disease (eg, heart attack and stroke) accounts for more death and disability than all cancers combined, there are no national screening guidelines for asymptomatic (subclinical) atherosclerosis, and there is no government- or healthcare-sponsored reimbursement for atherosclerosis screening. Part I and Part II of this consensus statement elaborated on new discoveries in the field of atherosclerosis that led to the concept of the "vulnerable patient." These landmark discoveries, along with new diagnostic and therapeutic options, have set the stage for the next step: translation of this knowledge into a new practice of preventive cardiology. The identification and treatment of the vulnerable patient are the focuses of this consensus statement. In this report, the Screening for Heart Attack Prevention and Education (SHAPE) Task Force presents a new practice guideline for cardiovascular screening in the asymptomatic at-risk population. In summary, the SHAPE Guideline calls for noninvasive screening of all asymptomatic men 45-75 years of age and asymptomatic women 55-75 years of age (except those defined as very low risk) to detect and treat those with subclinical atherosclerosis. A variety of screening tests are available, and the cost-effectiveness of their use in a comprehensive strategy must be validated. Some of these screening tests, such as measurement of coronary artery calcification by computed tomography scanning and carotid artery intima-media thickness and plaque by ultrasonography, have been available longer than others and are capable of providing direct evidence for the presence and extent of atherosclerosis. Both of these imaging methods provide prognostic information of proven value regarding the future risk of heart attack and stroke. Careful and responsible

  4. Vulnerability

    NASA Technical Reports Server (NTRS)

    Taback, I.

    1979-01-01

    The discussion of vulnerability begins with a description of some of the electrical characteristics of fibers before definiting how vulnerability calculations are done. The vulnerability results secured to date are presented. The discussion touches on post exposure vulnerability. After a description of some shock hazard work now underway, the discussion leads into a description of the planned effort and some preliminary conclusions are presented.

  5. A Foundation for the Accurate Prediction of the Soft Error Vulnerability of Scientific Applications

    SciTech Connect

    Bronevetsky, G; de Supinski, B; Schulz, M

    2009-02-13

    Understanding the soft error vulnerability of supercomputer applications is critical as these systems are using ever larger numbers of devices that have decreasing feature sizes and, thus, increasing frequency of soft errors. As many large scale parallel scientific applications use BLAS and LAPACK linear algebra routines, the soft error vulnerability of these methods constitutes a large fraction of the applications overall vulnerability. This paper analyzes the vulnerability of these routines to soft errors by characterizing how their outputs are affected by injected errors and by evaluating several techniques for predicting how errors propagate from the input to the output of each routine. The resulting error profiles can be used to understand the fault vulnerability of full applications that use these routines.

  6. The Effects of the Mediterranean Diet on Biomarkers of Vascular Wall Inflammation and Plaque Vulnerability in Subjects with High Risk for Cardiovascular Disease. A Randomized Trial

    PubMed Central

    Casas, Rosa; Sacanella, Emilio; Urpí-Sardà, Mireia; Chiva-Blanch, Gemma; Ros, Emilio; Martínez-González, Miguel-Angel; Covas, Maria-Isabel; Salas-Salvadó, Jordi; Fiol, Miquel; Arós, Fernando; Estruch, Ramon

    2014-01-01

    Background Adherence to the Mediterranean diet (MD) is associated with reduced morbidity and mortality due to cardiovascular disease. However, how the MD exerts its effects is not fully known. Aim To assess the 12-month effects of two enhanced MDs compared to a low-fat diet on inflammatory biomarkers related to atherosclerosis and plaque vulnerability in a subcohort of the PREDIMED (Prevención con Dieta Mediterránea) study. Methods A total of 164 participants at high risk for cardiovascular disease were randomized into three diet groups: MD supplemented with 50mL/d of extra virgin olive oil (MD+EVOO) or 30 g/d of nuts (MD+Nuts) and a low-fat diet. Changes in classical cardiovascular risk factors, inflammatory biomarkers of atherosclerosis and plaque vulnerability were measured after 12 months of intervention. Results Compared to participants in the low-fat diet group, those receiving MD+EVOO and MD+Nuts showed a higher decrease in systolic (6mmHg) and diastolic (3mmHg) blood pressure (P = 0.02; both), as well as a reduction of 10% and 8% in LDL-cholesterol (P = 0.04), respectively. Patients in the MD+Nuts group showed a significant reduction of 34% in CD40 expression on monocyte surface compared to low-fat diet patients (P = 0.03). In addition, inflammatory biomarkers related to plaque instability such as C-reactive protein and interleukin-6 were reduced by 45% and 35% and 95% and 90% in the MD+EVOO and MD+Nuts groups, respectively (P<0.05; all) compared to the low-fat diet group. Likewise, sICAM and P-selectin were also reduced by 50% and 27%, respectively in the MD+EVOO group (P = 0.04) and P-selectin by 19% in MD+Nuts group (P = 0.04) compared to the low-fat diet group. Conclusions Adherence to the MD is associated with an increase in serum markers of atheroma plaque stability which may explain, at least in part, the protective role of MD against ischemic heart disease. Trial Registration www.controlled-trials.com ISRCTN35739639 PMID

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

    PubMed

    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.

  8. On the potential of a new IVUS elasticity modulus imaging approach for detecting vulnerable atherosclerotic coronary plaques: In vitro vessel phantom study

    PubMed Central

    Le Floc’h, Simon; Cloutier, Guy; Finet, Gérard; Tracqui, Philippe; Pettigrew, Roderic I.; Ohayon, Jacques

    2016-01-01

    Peak cap stress amplitude is recognized as a good indicator of vulnerable plaque (VP) rupture. However, such stress evaluation strongly relies on a precise, but still lacking, knowledge of the mechanical properties exhibited by the plaque components. As a first response to this limitation, our group recently developed, in a previous theoretical study, an original approach, called iMOD, which reconstructs elasticity maps (or modulograms) of atheroma plaques from the estimation of strain fields. In the present in vitro experimental study, conducted on PVA-C arterial phantoms, we investigate the benefit of coupling the iMOD procedure with the acquisition of intravascular ultrasound (IVUS) measurements for detection of VP. Our results show that the combined iMOD-IVUS strategy : 1) successfully detected and quantified soft inclusion contours with high positive predictive values and sensitivities of 89.7 ± 3.9% and 81.5 ± 8.8 %, respectively, 2) estimated reasonably cap thicknesses larger than ~300 µm, but underestimated thinner caps, and 3) quantified satisfactorily Young's modulus of hard medium (mean value of 109.7 ± 23.7 kPa instead of 145.4 ± 31.8 kPa), but overestimated the stiffness of soft inclusions (mean Young`s moduli of 31.4 ± 9.7 kPa instead of 17.6 ± 3.4 kPa). All together, these results demonstrate a promising benefit of the new iMOD-IVUS clinical imaging method for in vivo VP detection. PMID:20826899

  9. Plaque regression and plaque stabilisation in cardiovascular diseases

    PubMed Central

    Dave, Tarun; Ezhilan, J.; Vasnawala, Hardik; Somani, Vinod

    2013-01-01

    Atherosclerosis is characterized by formation of plaques on the inner walls of arteries that threatens to become the leading cause of death worldwide via its sequelae of myocardial infarction and stroke. Endothelial dysfunction leads to cholesterol uptake and accumulation of inflammatory markers within the plaque. The stability of a plaque eventually depends on the balance between vascular smooth muscle cells that stabilize it and the inflammatory cells like macrophages and T lymphocytes that make it prone to rupture. The current approach to manage atherosclerosis focuses on the treatment of a ruptured plaque and efforts have been made to reduce the risk of plaque rupture by identifying vulnerable plaques and treating them before they precipitate into clinical events. New diagnostic approaches such as IVUS and CIMT ultrasound are now being preferred over traditional coronary angiography because of their better accuracy in measuring plaque volume rather than the level of stenosis caused. The present review highlights the literature available on two prevalent approaches to manage a vulnerable plaque, namely, plaque stabilization and plaque regression, and their validation through various treatment modalities in recent plaque management studies. Plaque stabilization focuses on stabilizing the content of plaque and strengthening the overlying endothelium, while plaque regression focuses on the overall reduction in plaque volume and to reverse the arterial endothelium to its normal functional state. Although earlier studies contemplated the practicality of plaque regression and focused greatly on stabilization of a vulnerable plaque, our review indicated that, aided by the use of superior diagnostics tools, more intensive lipid modifying therapies have resulted in actual plaque regression. PMID:24381872

  10. Application of infrared fiber optic imaging in atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Guo, Bujin; Casscells, S. W.; Bearman, Gregory H.; McNatt, Janice; Naghevi, Morteza; Malik, Basit A.; Gul, Khawar; Willerson, James T.

    1999-07-01

    Rupture of atherosclerotic plaques - the main cause of heart attach and stokes - is not predictable. Hence even treadmill stress tests fail to detect many persons at risk. Fatal plaques are found at autopsies to be associated with active inflammatory cells. Classically, inflammation is detected by its swelling, red color, pain and heat. We have found that heat accurately locates the dangerous plaques that are significantly warmer then atherosclerotic plaques without the same inflammation. In order to develop a non-surgical method of locating these plaques, an IR fiber optic imaging system has been developed in our laboratory to evalute the causes and effect of heat in atherosclerotic plaques. The fiber optical imagin bundle consists of 900 individual As2S3 chalcogenide glass fibers which transmit IR radiation from 0.7 micrometers 7 micrometers with little energy loss. By combining that with a highly sensitive Indium Antimonide IR focal plane array detector, we are able to obtain thermal graphic images in situ. The temperature heterogeneity of atherosclerotic plaques developed in the arteral of the experimental animal models is under study with the new device. The preliminary experimental results from the animal model are encouraging. The potential of using this new technology in diagnostic evaluation of the vulnerable atherosclerotic plaques is considerable.

  11. Ultrafast optical-ultrasonic system and miniaturized catheter for imaging and characterizing atherosclerotic plaques in vivo

    PubMed Central

    Li, Jiawen; Ma, Teng; Mohar, Dilbahar; Steward, Earl; Yu, Mingyue; Piao, Zhonglie; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Patel, Pranav M.; Chen, Zhongping

    2015-01-01

    Atherosclerotic coronary artery disease (CAD) is the number one cause of death worldwide. The majority of CAD-induced deaths are due to the rupture of vulnerable plaques. Accurate assessment of plaques is crucial to optimize treatment and prevent death in patients with CAD. Current diagnostic techniques are often limited by either spatial resolution or penetration depth. Several studies have proved that the combined use of optical and ultrasonic imaging techniques increase diagnostic accuracy of vulnerable plaques. Here, we introduce an ultrafast optical-ultrasonic dual-modality imaging system and flexible miniaturized catheter, which enables the translation of this technology into clinical practice. This system can perform simultaneous optical coherence tomography (OCT)-intravascular ultrasound (IVUS) imaging at 72 frames per second safely in vivo, i.e., visualizing a 72 mm-long artery in 4 seconds. Results obtained in atherosclerotic rabbits in vivo and human coronary artery segments show that this ultrafast technique can rapidly provide volumetric mapping of plaques and clearly identify vulnerable plaques. By providing ultrafast imaging of arteries with high resolution and deep penetration depth simultaneously, this hybrid IVUS-OCT technology opens new and safe opportunities to evaluate in real-time the risk posed by plaques, detect vulnerable plaques, and optimize treatment decisions. PMID:26678300

  12. Ex vivo differential phase contrast and magnetic resonance imaging for characterization of human carotid atherosclerotic plaques.

    PubMed

    Meletta, Romana; Borel, Nicole; Stolzmann, Paul; Astolfo, Alberto; Klohs, Jan; Stampanoni, Marco; Rudin, Markus; Schibli, Roger; Krämer, Stefanie D; Herde, Adrienne Müller

    2015-10-01

    Non-invasive detection of specific atherosclerotic plaque components related to vulnerability is of high clinical relevance to prevent cerebrovascular events. The feasibility of magnetic resonance imaging (MRI) for characterization of plaque components was already demonstrated. We aimed to evaluate the potential of ex vivo differential phase contrast X-ray tomography (DPC) to accurately characterize human carotid plaque components in comparison to high field multicontrast MRI and histopathology. Two human plaque segments, obtained from carotid endarterectomy, classified according to criteria of the American Heart Association as stable and unstable plaque, were examined by ex vivo DPC tomography and multicontrast MRI (T1-, T2-, and proton density-weighted imaging, magnetization transfer contrast, diffusion-weighted imaging). To identify specific plaque components, the plaques were subsequently sectioned and stained for fibrous and cellular components, smooth muscle cells, hemosiderin, and fibrin. Histological data were then matched with DPC and MR images to define signal criteria for atherosclerotic plaque components. Characteristic structures, such as the lipid and necrotic core covered by a fibrous cap, calcification and hemosiderin deposits were delineated by histology and found with excellent sensitivity, resolution and accuracy in both imaging modalities. DPC tomography was superior to MRI regarding resolution and soft tissue contrast. Ex vivo DPC tomography allowed accurate identification of structures and components of atherosclerotic plaques at different lesion stages, in good correlation with histopathological findings.

  13. Integrating metabolic performance, thermal tolerance, and plasticity enables for more accurate predictions on species vulnerability to acute and chronic effects of global warming.

    PubMed

    Magozzi, Sarah; Calosi, Piero

    2015-01-01

    Predicting species vulnerability to global warming requires a comprehensive, mechanistic understanding of sublethal and lethal thermal tolerances. To date, however, most studies investigating species physiological responses to increasing temperature have focused on the underlying physiological traits of either acute or chronic tolerance in isolation. Here we propose an integrative, synthetic approach including the investigation of multiple physiological traits (metabolic performance and thermal tolerance), and their plasticity, to provide more accurate and balanced predictions on species and assemblage vulnerability to both acute and chronic effects of global warming. We applied this approach to more accurately elucidate relative species vulnerability to warming within an assemblage of six caridean prawns occurring in the same geographic, hence macroclimatic, region, but living in different thermal habitats. Prawns were exposed to four incubation temperatures (10, 15, 20 and 25 °C) for 7 days, their metabolic rates and upper thermal limits were measured, and plasticity was calculated according to the concept of Reaction Norms, as well as Q10 for metabolism. Compared to species occupying narrower/more stable thermal niches, species inhabiting broader/more variable thermal environments (including the invasive Palaemon macrodactylus) are likely to be less vulnerable to extreme acute thermal events as a result of their higher upper thermal limits. Nevertheless, they may be at greater risk from chronic exposure to warming due to the greater metabolic costs they incur. Indeed, a trade-off between acute and chronic tolerance was apparent in the assemblage investigated. However, the invasive species P. macrodactylus represents an exception to this pattern, showing elevated thermal limits and plasticity of these limits, as well as a high metabolic control. In general, integrating multiple proxies for species physiological acute and chronic responses to increasing

  14. 3D MRI-based anisotropic FSI models with cyclic bending for human coronary atherosclerotic plaque mechanical analysis.

    PubMed

    Tang, Dalin; Yang, Chun; Kobayashi, Shunichi; Zheng, Jie; Woodard, Pamela K; Teng, Zhongzhao; Billiar, Kristen; Bach, Richard; Ku, David N

    2009-06-01

    Heart attack and stroke are often caused by atherosclerotic plaque rupture, which happens without warning most of the time. Magnetic resonance imaging (MRI)-based atherosclerotic plaque models with fluid-structure interactions (FSIs) have been introduced to perform flow and stress/strain analysis and identify possible mechanical and morphological indices for accurate plaque vulnerability assessment. For coronary arteries, cyclic bending associated with heart motion and anisotropy of the vessel walls may have significant influence on flow and stress/strain distributions in the plaque. FSI models with cyclic bending and anisotropic vessel properties for coronary plaques are lacking in the current literature. In this paper, cyclic bending and anisotropic vessel properties were added to 3D FSI coronary plaque models so that the models would be more realistic for more accurate computational flow and stress/strain predictions. Six computational models using one ex vivo MRI human coronary plaque specimen data were constructed to assess the effects of cyclic bending, anisotropic vessel properties, pulsating pressure, plaque structure, and axial stretch on plaque stress/strain distributions. Our results indicate that cyclic bending and anisotropic properties may cause 50-800% increase in maximum principal stress (Stress-P1) values at selected locations. The stress increase varies with location and is higher when bending is coupled with axial stretch, nonsmooth plaque structure, and resonant pressure conditions (zero phase angle shift). Effects of cyclic bending on flow behaviors are more modest (9.8% decrease in maximum velocity, 2.5% decrease in flow rate, 15% increase in maximum flow shear stress). Inclusion of cyclic bending, anisotropic vessel material properties, accurate plaque structure, and axial stretch in computational FSI models should lead to a considerable improvement of accuracy of computational stress/strain predictions for coronary plaque vulnerability

  15. Optimization of K-edge imaging for vulnerable plaques using gold nanoparticles and energy resolved photon counting detectors: a simulation study.

    PubMed

    Alivov, Yahya; Baturin, Pavlo; Le, Huy Q; Ducote, Justin; Molloi, Sabee

    2014-01-06

    We investigated the effect of different imaging parameters, such as dose, beam energy, energy resolution and the number of energy bins, on the image quality of K-edge spectral computed tomography (CT) of gold nanoparticles (GNP) accumulated in an atherosclerotic plaque. A maximum likelihood technique was employed to estimate the concentration of GNP, which served as a targeted intravenous contrast material intended to detect the degree of the plaque's inflammation. The simulation studies used a single-slice parallel beam CT geometry with an x-ray beam energy ranging between 50 and 140 kVp. The synthetic phantoms included small (3 cm in diameter) cylinder and chest (33 × 24 cm(2)) phantoms, where both phantoms contained tissue, calcium and gold. In the simulation studies, GNP quantification and background (calcium and tissue) suppression tasks were pursued. The x-ray detection sensor was represented by an energy resolved photon counting detector (e.g., CdZnTe) with adjustable energy bins. Both ideal and more realistic (12% full width at half maximum (FWHM) energy resolution) implementations of the photon counting detector were simulated. The simulations were performed for the CdZnTe detector with a pixel pitch of 0.5-1 mm, which corresponds to a performance without significant charge sharing and cross-talk effects. The Rose model was employed to estimate the minimum detectable concentration of GNPs. A figure of merit (FOM) was used to optimize the x-ray beam energy (kVp) to achieve the highest signal-to-noise ratio with respect to the patient dose. As a result, the successful identification of gold and background suppression was demonstrated. The highest FOM was observed at the 125 kVp x-ray beam energy. The minimum detectable GNP concentration was determined to be approximately 1.06 µmol mL(-1) (0.21 mg mL(-1)) for an ideal detector and about 2.5 µmol mL(-1) (0.49 mg mL(-1)) for a more realistic (12% FWHM) detector. The studies show the optimal

  16. Optimization of the K-edge imaging for vulnerable plaques using gold nanoparticles and energy-resolved photon counting detectors: a simulation study

    PubMed Central

    Alivov, Yahya; Baturin, Pavlo; Le, Huy Q.; Ducote, Justin; Molloi, Sabee

    2014-01-01

    We investigated the effect of different imaging parameters such as dose, beam energy, energy resolution, and number of energy bins on image quality of K-edge spectral computed tomography (CT) of gold nanoparticles (GNP) accumulated in an atherosclerotic plaque. Maximum likelihood technique was employed to estimate the concentration of GNP, which served as a targeted intravenous contrast material intended to detect the degree of plaque's inflammation. The simulations studies used a single slice parallel beam CT geometry with an X-ray beam energy ranging between 50 and 140 kVp. The synthetic phantoms included small (3 cm in diameter) cylinder and chest (33x24 cm2) phantom, where both phantoms contained tissue, calcium, and gold. In the simulation studies GNP quantification and background (calcium and tissue) suppression task were pursued. The X-ray detection sensor was represented by an energy resolved photon counting detector (e.g., CdZnTe) with adjustable energy bins. Both ideal and more realistic (12% FWHM energy resolution) implementations of photon counting detector were simulated. The simulations were performed for the CdZnTe detector with pixel pitch of 0.5-1 mm, which corresponds to the performance without significant charge sharing and cross-talk effects. The Rose model was employed to estimate the minimum detectable concentration of GNPs. A figure of merit (FOM) was used to optimize the X-ray beam energy (kVp) to achieve the highest signal-to-noise ratio (SNR) with respect to patient dose. As a result, the successful identification of gold and background suppression was demonstrated. The highest FOM was observed at 125 kVp X-ray beam energy. The minimum detectable GNP concentration was determined to be approximately 1.06 μmol/mL (0.21 mg/mL) for an ideal detector and about 2.5 μmol/mL (0.49 mg/mL) for more realistic (12% FWHM) detector. The studies show the optimal imaging parameters at lowest patient dose using an energy resolved photon counting detector

  17. Vascular MR segmentation: wall and plaque

    NASA Astrophysics Data System (ADS)

    Yang, Fuxing; Holzapfel, Gerhard; Schulze-Bauer, Christian; Stollberger, Rudolf; Thedens, Daniel; Bolinger, Lizann; Stolpen, Alan; Sonka, Milan

    2003-05-01

    Cardiovascular events frequently result from local rupture of vulnerable atherosclerotic plaque. Non-invasive assessment of plaque vulnerability is needed to allow institution of preventive measures before heart attack or stroke occur. A computerized method for segmentation of arterial wall layers and plaque from high-resolution volumetric MR images is reported. The method uses dynamic programming to detect optimal borders in each MRI frame. The accuracy of the results was tested in 62 T1-weighted MR images from 6 vessel specimens in comparison to borders manually determined by an expert observer. The mean signed border positioning errors for the lumen, internal elastic lamina, and external elastic lamina borders were -0.12+/-0.14 mm, 0.04+/-0.12mm, and -0.15+/-0.13 mm, respectively. The presented wall layer segmentation approach is one of the first steps towards non-invasive assessment of plaque vulnerability in atherosclerotic subjects.

  18. Stabilization of high-risk plaques

    PubMed Central

    Takata, Kohei; Zhang, Bo; Miura, Shin-ichiro; Saku, Keijiro

    2016-01-01

    The prevalence of atherosclerotic cardiovascular diseases (ASCVDs) is increasing globally and they have become the leading cause of death in most countries. Numerous experimental and clinical studies have been conducted to identify major risk factors and effective control strategies for ASCVDs. The development of imaging modalities with the ability to determine the plaque composition enables us to further identify high-risk plaque and evaluate the effectiveness of different treatment strategies. While intensive lipid-lowering by statins can stabilize or even regress plaque by various mechanisms, such as the reduction of lipid accumulation in a necrotic lipid core, the reduction of inflammation, and improvement of endothelial function, there are still considerable residual risks that need to be understood. We reviewed important findings regarding plaque vulnerability and some encouraging emerging approaches for plaque stabilization. PMID:27500090

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

    PubMed Central

    Assemat, P.; Siu, K.K.; Armitage, J.A.; Hokke, S.N.; Dart, A.; Chin-Dusting, J.; Hourigan, K.

    2014-01-01

    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. PMID:25349678

  20. Mechanical analysis of arterial plaques in native geometry with OCT wall motion analysis

    PubMed Central

    Robertson, Claire; Heidari, Andrew E.; Chen, Zhongping; George, Steven C.

    2014-01-01

    The mechanical behavior of an atherosclerotic plaque may encode information about the type, composition, and vulnerability to rupture. Human arterial segments with varying plaque burden were analyzed ex vivo with optical coherence tomography (OCT) to determine plaque type and to determine compliance during pulsatile inflation in their native geometry. Calcifications and lipid filled plaques showed markedly different compliance when analyzed with OCT wall motion analysis. There was also a trend towards increased circumferential variation in arterial compliance with increasing plaque burden. PMID:24388166

  1. Imaging Modalities to Identity Inflammation in an Atherosclerotic Plaque

    PubMed Central

    Goel, Sunny; Miller, Avraham; Agarwal, Chirag; Zakin, Elina; Acholonu, Michael; Gidwani, Umesh; Sharma, Abhishek; Kulbak, Guy; Shani, Jacob; Chen, On

    2015-01-01

    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. PMID:26798515

  2. Multiphoton microscopy of atheroslcerotic plaques

    NASA Astrophysics Data System (ADS)

    Lilledahl, Magnus B.; de Lange Davies, Catharina; Haugen, Olav A.; Svaasand, Lars O.

    2007-02-01

    Multiphoton microscopy is a techniques that fascilitates three dimensional imaging of intact, unstained tissue. Especially connective tissue has a relatively strong nonlinear optical response and can easily be imaged. Atherosclerosis is a disease where lipids accumulate in the vessel wall and there is a thickening of the intima by growth of a cap of connective tissue. The mechanical strength of this fibrous cap is of clinically importance. If the cap ruptures a thrombosis forms which can block a coronary vessel and therby causing myocardial infarction. Multiphoton microscopy can be used to image the fibrous cap and thereby determine the thickness of the cap and the structure of the connective fibres. This could possibly be developed into a diagnostic and clincal tool to monitor the vulnerability of a plaque and also to better understand the development of a plaque and effects of treatment. We have collected multiphoton microscopy images from atherosclerotic plaque in human aorta, both two photon excited fluorescens and second harmonic generated signal. The feasability of using this technique to determine the state of the plaque is explored.

  3. Saliva and dental plaque.

    PubMed

    Rudney, J D

    2000-12-01

    Dental plaque is being redefined as oral biofilm. Diverse overlapping microbial consortia are present on all oral tissues. Biofilms are structured, displaying features like channels and projections. Constituent species switch back and forth between sessile and planktonic phases. Saliva is the medium for planktonic suspension. Several major functions can be defined for saliva in relation to oral biofilm. It serves as a medium for transporting planktonic bacteria within and between mouths. Bacteria in transit may be vulnerable to negative selection. Salivary agglutinins may prevent reattachment to surfaces. Killing by antimicrobial proteins may lead to attachment of dead cells. Salivary proteins form conditioning films on all oral surfaces. This contributes to positive selection for microbial adherence. Saliva carries chemical messengers which allow live adherent cells to sense a critical density of conspecifics. Growth begins, and thick biofilms may become resistant to antimicrobial substances. Salivary macromolecules may be catabolized, but salivary flow also may clear dietary substrates. Salivary proteins act in ways that benefit both host and microbe. All have multiple functions, and many do the same job. They form heterotypic complexes, which may exist in large micelle-like structures. These issues make it useful to compare subjects whose saliva functions differently. We have developed a simultaneous assay for aggregation, killing, live adherence, and dead adherence of oral species. Screening of 149 subjects has defined high killing/low adherence, low killing/high adherence, high killing/high adherence, and low killing/low adherence groups. These will be evaluated for differences in their flora.

  4. Research Progress on the Risk Factors and Outcomes of Human Carotid Atherosclerotic Plaques

    PubMed Central

    Xiong, Xiang-Dong; Xiong, Wei-Dong; Xiong, Shang-Shen; Chen, Gui-Hai

    2017-01-01

    Objective: Atherosclerosis is an inflammatory process that results in complex lesions or plaques that protrude into the arterial lumen. Carotid atherosclerotic plaque rupture, with distal atheromatous debris embolization, causes cerebrovascular events. This review aimed to explore research progress on the risk factors and outcomes of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention. Data Sources: We searched the PubMed database for recently published research articles up to June 2016, with the key words of “risk factors”, “outcomes”, “blood components”, “molecular mechanisms”, “cellular mechanisms”, and “human carotid atherosclerotic plaques”. Study Selection: The articles, regarding the latest developments related to the risk factors and outcomes, atherosclerotic plaque composition, blood components, and consequences of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention, were selected. Results: This review described the latest researches regarding the interactive effects of both traditional and novel risk factors for human carotid atherosclerotic plaques, novel insights into human carotid atherosclerotic plaque composition and blood components, and consequences of human carotid atherosclerotic plaque. Conclusion: Carotid plaque biology and serologic biomarkers of vulnerability can be used to predict the risk of cerebrovascular events. Furthermore, plaque composition, rather than lesion burden, seems to most predict rupture and subsequent thrombosis. PMID:28303857

  5. F-18 Fluoride Positron Emission Tomography-Computed Tomography for Detecting Atherosclerotic Plaques.

    PubMed

    Kang, Won Jun

    2015-01-01

    A large number of major cardiovascular events occur in patients due to minimal or some lumen narrowing of the coronary artery. Recent biological studies have shown that the biological composition or vulnerability of the plaque is more critical for plaque rupture compared to the degree of stenosis. To overcome the limitations of anatomical images, molecular imaging techniques have been suggested as promising imaging tools in various fields. F-18 fluorodeoxyglucose (FDG), which is widely used in the field of oncology, is an example of molecular probes used in atherosclerotic plaque evaluation. FDG is a marker of plaque macrophage glucose utilization and inflammation, which is a prominent characteristic of vulnerable plaque. Recently, F-18 fluoride has been used to visualize vulnerable plaque in clinical studies. F-18 fluoride accumulates in regions of active microcalcification, which is normally observed during the early stages of plaque formation. More studies are warranted on the accumulation of F-18 fluoride and plaque formation/vulnerability; however, due to high specific accumulation, low background activity, and easy accessibility, F-18 fluoride is emerging as a promising non-invasive imaging probe to detect vulnerable plaque.

  6. Simulation of human atherosclerotic femoral plaque tissue: the influence of plaque material model on numerical results

    PubMed Central

    2015-01-01

    Background Due to the limited number of experimental studies that mechanically characterise human atherosclerotic plaque tissue from the femoral arteries, a recent trend has emerged in current literature whereby one set of material data based on aortic plaque tissue is employed to numerically represent diseased femoral artery tissue. This study aims to generate novel vessel-appropriate material models for femoral plaque tissue and assess the influence of using material models based on experimental data generated from aortic plaque testing to represent diseased femoral arterial tissue. Methods Novel material models based on experimental data generated from testing of atherosclerotic femoral artery tissue are developed and a computational analysis of the revascularisation of a quarter model idealised diseased femoral artery from a 90% diameter stenosis to a 10% diameter stenosis is performed using these novel material models. The simulation is also performed using material models based on experimental data obtained from aortic plaque testing in order to examine the effect of employing vessel appropriate material models versus those currently employed in literature to represent femoral plaque tissue. Results Simulations that employ material models based on atherosclerotic aortic tissue exhibit much higher maximum principal stresses within the plaque than simulations that employ material models based on atherosclerotic femoral tissue. Specifically, employing a material model based on calcified aortic tissue, instead of one based on heavily calcified femoral tissue, to represent diseased femoral arterial vessels results in a 487 fold increase in maximum principal stress within the plaque at a depth of 0.8 mm from the lumen. Conclusions Large differences are induced on numerical results as a consequence of employing material models based on aortic plaque, in place of material models based on femoral plaque, to represent a diseased femoral vessel. Due to these large

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Motion compensation method using dynamic programming for quantification of neovascularization in carotid atherosclerotic plaques with contrast enhanced ultrasound (CEUS)

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    Intraplaque neovascularization (IPN) has been linked with progressive atherosclerotic disease and plaque instability in several studies. Quantification of IPN may allow early detection of vulnerable plaques. A dedicated motion compensation method with normalized-cross-correlation (NCC) block matching combined with multidimensional (2D+time) dynamic programming (MDP) was developed for quantification of IPN in small plaques (<30% diameter stenosis). The method was compared to NCC block matching without MDP (forward tracking (FT)) and showed to improve motion tracking. Side-by-side CEUS and B-mode ultrasound images of carotid arteries were acquired by a Philips iU22 system with a L9-3 linear array probe. The motion pattern for the plaque region was obtained from the Bmode images with MDP. MDP results were evaluated in-vitro by a phantom and in-vivo by comparing to manual tracking of three experts for multibeat-image-sequences (MIS) of 11 plaques. In the in-vivo images, the absolute error was 72+/-55μm (mean+/-SD) for X (longitudinal) and 34+/-23μm for Y (radial). The method's success rate was visually assessed on 67 MIS. The tracking was considered failed if it deviated >2 pixels (~200μm) from true motion in any frame. Tracking was scored as fully successful in 63 MIS (94%) for MDP vs. 52(78%) for FT. The range of displacement over these 63 was 1045+/-471μm (X) and 395+/-216μm (Y). The tracking sporadically failed in 4 MIS (6%) due to poor image quality, jugular vein proximity and out-of-plane motion. Motion compensation showed improved lumen-plaque contrast separation. In conclusion, the proposed method is sufficiently accurate and successful for in vivo application.

  9. Fluorescence lifetime imaging microscopy for the characterization of atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Phipps, Jennifer; Sun, Yinghua; Saroufeem, Ramez; Hatami, Nisa; Marcu, Laura

    2009-02-01

    Atherosclerotic plaque composition has been associated with plaque instability and rupture. This study investigates the use of fluorescence lifetime imaging microscopy (FLIM) for mapping plaque composition and assessing features of vulnerability. Measurements were conducted in atherosclerotic human aortic samples using an endoscopic FLIM system (spatial resolution of 35 µm temporal resolution 200 ps) developed in our lab which allows mapping in one measurement the composition within a volume of 4 mm diameter x 250 µm depth. Each pixel in the image represents a corresponding fluorescence lifetime value; images are formed through a flexible 0.6 mm side-viewing imaging bundle which allows for further intravascular applications. Based on previously recorded spectra of human atherosclerotic plaque, fluorescence emission was collected through two filters: f1: 377/50 and f2: 460/60 (center wavelength/bandwidth), which together provides the greatest discrimination between intrinsic fluorophores related to plaque vulnerability. We have imaged nine aortas and lifetime images were retrieved using a Laguerre expansion deconvolution technique and correlated with histopathology. Early results demonstrate discrimination using fluorescence lifetime between early, lipid-rich, and collagen-rich lesions which are consistent with previously reported time-resolved atherosclerotic plaque measurements.

  10. A four-criterion selection procedure for atherosclerotic plaque elasticity reconstruction based on in vivo coronary intravascular ultrasound radial strain sequences.

    PubMed

    Le Floc'h, Simon; Cloutier, Guy; Saijo, Yoshifumi; Finet, Gérard; Yazdani, Saami K; Deleaval, Flavien; Rioufol, Gilles; Pettigrew, Roderic I; Ohayon, Jacques

    2012-12-01

    Plaque elasticity (i.e., modulogram) and morphology are good predictors of plaque vulnerability. Recently, our group developed an intravascular ultrasound (IVUS) elasticity reconstruction method which was successfully implemented in vitro using vessel phantoms. In vivo IVUS modulography, however, remains a major challenge as the motion of the heart prevents accurate strain field estimation. We therefore designed a technique to extract accurate strain fields and modulograms from recorded IVUS sequences. We identified a set of four criteria based on tissue overlapping, RF-correlation coefficient between two successive frames, performance of the elasticity reconstruction method to recover the measured radial strain, and reproducibility of the computed modulograms over the cardiac cycle. This four-criterion selection procedure (4-CSP) was successfully tested on IVUS sequences obtained in twelve patients referred for a directional coronary atherectomy intervention. This study demonstrates the potential of the IVUS modulography technique based on the proposed 4-CSP to detect vulnerable plaques in vivo.

  11. Evaluation of plaques and stenosis.

    PubMed

    Arnoldi, Elisabeth; Henzler, Thomas; Bastarrika, Gorka; Thilo, Christian; Nikolaou, Konstantin; Schoepf, U Joseph

    2010-07-01

    Cardiac CT scan has emerged from a research tool to a widely used clinical modality in the diagnostic management of coronary artery disease. Based on evidence of numerous clinical studies coronary CT angiography (cCTA) has emerged as a fast, accurate, and noninvasive alternative to conventional angiography in selected patient populations. A major strength of cCTA is its ability to combine information on the coronary artery anatomy, the vessel lumen, and atherosclerotic lesions. Recent investigations on the application of cCTA in myocardial perfusion imaging suggest that cCTA may allow analysis of the hemodynamic relevance of detected stenosis. Data is accumulating that supports its relevance for patient management and outcome. This article examines the role of cCTA for the evaluation of plaques and stenosis.

  12. Aetiology of pleural plaques

    PubMed Central

    Rous, V.; Studeny, J.

    1970-01-01

    Pleural plaques were found in 644 (6·6%) of 9,760 photofluorograms taken in 1965 in a region of Pelhřimov district; the incidence was highest in the age group 66-70 years. The advanced age of those affected may be explained by the greater frequency of the causative agent in the past. The disorder was known in Pelhřimov district as early as 1930; it was then thought to be posttuberculous. The past history of the cases was uninformative; as a rule, the only common previous disease was pleurisy with effusion, occurring in 9·7%. The general condition of those affected was excellent; only 8% were aware of the fact that pleural lesions were present. The disorder was found mainly in farmers, familial incidence was common, and if two generations of one family suffered from the condition, the older generation was affected in 100%. Pleural plaques consist morphologically of limited areas of hyalinized collagenous connective tissue with calcium salt deposits. Tubercle bacilli could not be cultivated from the lesions. Mineralological analysis showed no evidence of silicates in the pleural plaques and a normal content in the lungs. The aetiological factor responsible for the development of pleural plaques in Pelhřimov district is not known, but asbestos cannot be implicated. The unknown noxious agent is carried to the pleura by the lymph and blood stream. Pleural plaques are an endemic disorder. The traditional view that lesions are post-tuberculous appears, in the region submitted to this study, to be a possible explanation. Images PMID:5465601

  13. Influence of shear stress magnitude and direction on atherosclerotic plaque composition

    PubMed Central

    Mehta, Vikram V.; Bovens, Sandra M.; Mohri, Zahra; Poulsen, Christian Bo; Gsell, Willy; Tremoleda, Jordi L.; Towhidi, Leila; de Silva, Ranil; Petretto, Enrico; Krams, Rob

    2016-01-01

    The precise flow characteristics that promote different atherosclerotic plaque types remain unclear. We previously developed a blood flow-modifying cuff for ApoE−/− mice that induces the development of advanced plaques with vulnerable and stable features upstream and downstream of the cuff, respectively. Herein, we sought to test the hypothesis that changes in flow magnitude promote formation of the upstream (vulnerable) plaque, whereas altered flow direction is important for development of the downstream (stable) plaque. We instrumented ApoE−/− mice (n = 7) with a cuff around the left carotid artery and imaged them with micro-CT (39.6 µm resolution) eight to nine weeks after cuff placement. Computational fluid dynamics was then performed to compute six metrics that describe different aspects of atherogenic flow in terms of wall shear stress magnitude and/or direction. In a subset of four imaged animals, we performed histology to confirm the presence of advanced plaques and measure plaque length in each segment. Relative to the control artery, the region upstream of the cuff exhibited changes in shear stress magnitude only (p < 0.05), whereas the region downstream of the cuff exhibited changes in shear stress magnitude and direction (p < 0.05). These data suggest that shear stress magnitude contributes to the formation of advanced plaques with a vulnerable phenotype, whereas variations in both magnitude and direction promote the formation of plaques with stable features. PMID:27853578

  14. Influence of shear stress magnitude and direction on atherosclerotic plaque composition.

    PubMed

    Pedrigi, Ryan M; Mehta, Vikram V; Bovens, Sandra M; Mohri, Zahra; Poulsen, Christian Bo; Gsell, Willy; Tremoleda, Jordi L; Towhidi, Leila; de Silva, Ranil; Petretto, Enrico; Krams, Rob

    2016-10-01

    The precise flow characteristics that promote different atherosclerotic plaque types remain unclear. We previously developed a blood flow-modifying cuff for ApoE(-/-) mice that induces the development of advanced plaques with vulnerable and stable features upstream and downstream of the cuff, respectively. Herein, we sought to test the hypothesis that changes in flow magnitude promote formation of the upstream (vulnerable) plaque, whereas altered flow direction is important for development of the downstream (stable) plaque. We instrumented ApoE(-/-) mice (n = 7) with a cuff around the left carotid artery and imaged them with micro-CT (39.6 µm resolution) eight to nine weeks after cuff placement. Computational fluid dynamics was then performed to compute six metrics that describe different aspects of atherogenic flow in terms of wall shear stress magnitude and/or direction. In a subset of four imaged animals, we performed histology to confirm the presence of advanced plaques and measure plaque length in each segment. Relative to the control artery, the region upstream of the cuff exhibited changes in shear stress magnitude only (p < 0.05), whereas the region downstream of the cuff exhibited changes in shear stress magnitude and direction (p < 0.05). These data suggest that shear stress magnitude contributes to the formation of advanced plaques with a vulnerable phenotype, whereas variations in both magnitude and direction promote the formation of plaques with stable features.

  15. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.

  16. La pelade par plaques

    PubMed Central

    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

  17. Characterizing atherosclerotic plaque with computed tomography: a contrast-detail study

    NASA Astrophysics Data System (ADS)

    Kasraie, Nima; Clarke, Geoffrey D.

    2012-02-01

    Plaque characterization may benefit from the increasing distinctiveness of the attenuating properties of different soft plaque components at lower energies. Due to the relative slight increase in the CT number of the nonadipose soft plaque at lower tube voltage settings vs. adipose plaque, a higher contrast between atheromous adipose and non-adipose plaque may become visible with modern 64 slice systems. A contrast-detail (C-D) phantom with varying plaque composition as the contrast generating method, was imaged on a commercial 64 slice MDCT system using 80, 120, and 140 kVp settings. The same phantom was also imaged on a Cone Beam CT (CBCT) system with a lower tube voltage of 75 kVp. The results of experiments from four different observers on three different plaque types (lipid, fiber, calcific) indicate that CT attenuation within lipid cores and fibrous masses vary not only with the percentage of lipid or fiber present, but also with the size of the cores. Furthermore, the C-D curve analysis for all three plaque types reveals that while the noise constraints prevent visible differentiation of soft plaque at current conventional 64 slice MDCT settings, CBCT exhibits superior visible contrast detectability than its conventional counterpart, with the latter having appreciably better resolution limits and beneficial lower tube voltages. This low voltage CT technique has the potential to be useful in composition based diagnosis of carotid vulnerable atherosclerotic plaque.

  18. A framework for the co-registration of hemodynamic forces and atherosclerotic plaque components

    PubMed Central

    Chiu, Bernard; Chen, Huijun; Chen, Yimin; Hatsukami, Thomas S.; Kerwin, William S.; Yuan, Chun

    2013-01-01

    Local hemodynamic forces, such as wall shear stress, are thought to trigger cellular and molecular mechanisms that determine atherosclerotic plaque vulnerability to rupture. Magnetic resonance imaging (MRI) has emerged as a powerful tool to characterize human carotid atherosclerotic plaque composition and morphology, and to identify plaque features shown to be key determinants of plaque vulnerability. Image-based computational fluid dynamics (CFD) has allowed researchers to obtain time-resolved wall shear stress (WSS) information of atherosclerotic carotid arteries. A deeper understanding of the mechanisms of initiation and progression of atherosclerosis can be obtained through the comparison of WSS and plaque composition and morphology. To date, however, advance in knowledge has been limited greatly due to the lack of a reliable infrastructure to perform such analysis. The aim of this study is to establish a framework that will allow for the co-registration and analysis of the three-dimensional (3D) distribution ofWSS and plaque components and morphology. The use of this framework will lead to future studies targeted to determining the role of WSS in atherosclerotic plaque progression and vulnerability. PMID:23945133

  19. Carotid plaque characterization using CT and MRI scans for synergistic image analysis

    NASA Astrophysics Data System (ADS)

    Getzin, Matthew; Xu, Yiqin; Rao, Arhant; Madi, Saaussan; Bahadur, Ali; Lennartz, Michelle R.; Wang, Ge

    2014-09-01

    Noninvasive determination of plaque vulnerability has been a holy grail of medical imaging. Despite advances in tomographic technologies , there is currently no effective way to identify vulnerable atherosclerotic plaques with high sensitivity and specificity. Computed tomography (CT) and magnetic resonance imaging (MRI) are widely used, but neither provides sufficient information of plaque properties. Thus, we are motivated to combine CT and MRI imaging to determine if the composite information can better reflect the histological determination of plaque vulnerability. Two human endarterectomy specimens (1 symptomatic carotid and 1 stable femoral) were imaged using Scanco Medical Viva CT40 and Bruker Pharmascan 16cm 7T Horizontal MRI / MRS systems. μCT scans were done at 55 kVp and tube current of 70 mA. Samples underwent RARE-VTR and MSME pulse sequences to measure T1, T2 values, and proton density. The specimens were processed for histology and scored for vulnerability using the American Heart Association criteria. Single modality-based analyses were performed through segmentation of key imaging biomarkers (i.e. calcification and lumen), image registration, measurement of fibrous capsule, and multi-component T1 and T2 decay modeling. Feature differences were analyzed between the unstable and stable controls, symptomatic carotid and femoral plaque, respectively. By building on the techniques used in this study, synergistic CT+MRI analysis may provide a promising solution for plaque characterization in vivo.

  20. Dental plaque identification at home

    MedlinePlus

    ... about 30 seconds. Then rinse your mouth with water and examine your teeth. Any red-stained areas are plaque. A small dental mirror may help you check all areas. The second method uses a plaque light. ... your mouth gently with water. Examine your teeth and gums while shining an ...

  1. Pioneer F Plaque Location

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Pioneer F spacecraft, destined to be the first man made object to escape from the solar system into interstellar space, carries this pictorial plaque. It is designed to show scientifically educated inhabitants of some other star system, who might intercept it millions of years from now, when Pioneer was launched, from where, and by what kind of beings. (Hopefully, any aliens reading the plaque will not use this knowledge to immediately invade Earth.) The design is etched into a 6 inch by 9 inch gold-anodized aluminum plate, attached to the spacecraft's attenna support struts in a position to help shield it from erosion by interstellar dust. The radiating lines at left represents the positions of 14 pulsars, a cosmic source of radio energy, arranged to indicate our sun as the home star of our civilization. The '1-' symbols at the ends of the lines are binary numbers that represent the frequencies of these pulsars at the time of launch of Pioneer F relative of that to the hydrogen atom shown at the upper left with a '1' unity symbol. The hydrogen atom is thus used as a 'universal clock,' and the regular decrease in the frequencies of the pulsars will enable another civilization to determine the time that has elapsed since Pioneer F was launched. The hydrogen is also used as a 'universal yardstick' for sizing the human figures and outline of the spacecraft shown on the right. The hydrogen wavelength, about 8 inches, multiplied by the binary number representing '8' shown next to the woman gives her height, 64 inches. The figures represent the type of creature that created Pioneer. The man's hand is raised in a gesture of good will. Across the bottom are the planets, ranging outward from the Sun, with the spacecraft trajectory arching away from Earth, passing Mars, and swinging by Jupiter.

  2. Clinical viability of carotid plaque strain estimation using B-mode ultrasound image sequences.

    PubMed

    Khan, Amir A; Hecker, Joseph C; Lal, Brajesh K; Sikdar, Siddhartha

    2016-08-01

    It is estimated that approximately 30% of ischemic strokes are caused by rupture of plaque in the carotid artery. Development of techniques focusing on identifying plaques that are vulnerable to rupture is thus indispensable for stroke prevention. Recent studies have demonstrated that motion analysis of plaques from B-mode and RF ultrasound (US) image sequences can be used to estimate plaque strain. However, viability of these methods in a clinical setting, with variable acquisition protocols, has not been demonstrated yet. In this paper, we explore the viability of estimating plaque strain from B-mode US images of asymptomatic patients, acquired in a real clinical setting with different acquisition settings, frame rates, and operators. Our proposed strain measures, shear strain rate entropy and variance, combined with the recently reported maximum absolute shear strain rate, show that the plaques fall into two distinct clusters. Moreover, these clusters show good correlations with plaque echolucency and echogenicity. We conclude that B-mode US imaging is a viable tool for characterizing plaque dynamics in clinical environments. In future studies, we plan to implement this method on multi-center studies for longitudinal monitoring of plaque.

  3. Coronary artery atherectomy reduces plaque shear strains: an endovascular elastography imaging study.

    PubMed

    Keshavarz-Motamed, Zahra; Saijo, Yoshifumi; Majdouline, Younes; Riou, Laurent; Ohayon, Jacques; Cloutier, Guy

    2014-07-01

    Mechanical response and properties of the arterial wall can be used to identify the biomechanical instability of plaques and predict their vulnerability to rupture. Shear strain elastography (SSE) is proposed to identify vulnerable plaque features attributed to mechanical structural heterogeneities. The aims of this study were: 1) to report on the potential of SSE to identify atherosclerotic plaques; and 2) to use SSE maps to highlight biomechanical changes in lesion characteristics after directional coronary atherectomy (DCA) interventions. For this purpose, SSE was imaged using in vivo intravascular ultrasound (IVUS) radio-frequency data collected from 12 atherosclerotic patients before and after DCA intervention. Coronary atherosclerotic plaques (pre-DCA) showed high SSE magnitudes with large affected areas. There were good correlations between SSE levels and soft plaque content (i.e., cellular fibrosis, thrombosis and fibrin) (mean |SSE| vs. soft plaque content: r = 0.82, p < 0.01). Significant differences were noticed between SSE images before and after DCA. Stable arteries (post-DCA) exhibited lower values than pre-DCA vessels (e.g., pre-DCA: mean |SSE| = 3.9 ± 0.2% vs. 1.1 ± 0.2% post-DCA, p < 0.001). Furthermore, SSE magnitude was statistically higher in plaques with a high level of inflammation (e.g., mean |SSE| had values of 4.8 ± 0.4% in plaques with high inflammation, whereas it was reduced to 1.8 ± 0.2% with no inflammation, p < 0.01). This study demonstrates the potential of the IVUS-based SSE technique to detect vulnerable plaques in vivo.

  4. Chronic miR-29 antagonism promotes favorable plaque remodeling in atherosclerotic mice.

    PubMed

    Ulrich, Victoria; Rotllan, Noemi; Araldi, Elisa; Luciano, Amelia; Skroblin, Philipp; Abonnenc, Mélanie; Perrotta, Paola; Yin, Xiaoke; Bauer, Ashley; Leslie, Kristen L; Zhang, Pei; Aryal, Binod; Montgomery, Rusty L; Thum, Thomas; Martin, Kathleen; Suarez, Yajaira; Mayr, Manuel; Fernandez-Hernando, Carlos; Sessa, William C

    2016-06-01

    Abnormal remodeling of atherosclerotic plaques can lead to rupture, acute myocardial infarction, and death. Enhancement of plaque extracellular matrix (ECM) may improve plaque morphology and stabilize lesions. Here, we demonstrate that chronic administration of LNA-miR-29 into an atherosclerotic mouse model improves indices of plaque morphology. This occurs due to upregulation of miR-29 target genes of the ECM (col1A and col3A) resulting in reduced lesion size, enhanced fibrous cap thickness, and reduced necrotic zones. Sustained LNA-miR-29 treatment did not affect circulating lipids, blood chemistry, or ECM of solid organs including liver, lung, kidney, spleen, or heart. Collectively, these data support the idea that antagonizing miR-29 may promote beneficial plaque remodeling as an independent approach to stabilize vulnerable atherosclerotic lesions.

  5. Ultrasound Vascular Elastography as a Tool for Assessing Atherosclerotic Plaques – A Systematic Literature Review

    PubMed Central

    Mahmood, B.; Ewertsen, C.; Carlsen, J.; Nielsen, M. B.

    2016-01-01

    Atherosclerosis is a widespread disease that accounts for nearly 3-quarters of deaths due to cardiovascular disease. Ultrasound elastography might be able to reliably identify characteristics associated with vulnerable plaques. There is a need for the evaluation of elastography and its ability 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 Library and Web of Science databases. A standardized template was used to extract relevant data following the PRISMA 2009 checklist. 20 articles were included in this paper. The studies were heterogeneous. All studies reported that elastography was a feasible technique and provided additional information 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 methodological variation between studies. There is a need for larger studies in a clinical setting to determine the full potential of elastography. PMID:27896334

  6. A feasibility study of carotid elastography for risk assessment of atherosclerotic plaques validated by magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Pan, Xiaochang; Huang, Lingyun; Huang, Manwei; Zhao, Xihai; He, Le; Yuan, Chun; Bai, Jing; Luo, Jianwen

    2014-03-01

    Stroke is a leading cause of mortality worldwide. One of its main reasons is rupture of carotid atherosclerotic plaques. Conventional B-mode ultrasound images and Doppler/color flow measurements are mostly used to evaluate degree of stenosis, which underestimates plaque vulnerability. Alternatively, the correspondence between multi-contrast magnetic resonance imaging (MRI) features, plaque composition and histology has been well established. In this study, the feasibility of ultrasound carotid elastography in risk assessment of carotid atherosclerotic plaques is investigated. Preliminarily in-vivo results on a small number of human subjects are initially validated by multi-contrast, highresolution MRI, and it shows that maximum strain rate might be feasible to evaluate the plaque vulnerability.

  7. Dental plaque as a biofilm and new research on biofilm removal by power toothbrushes.

    PubMed

    Dudgeon, Douglas J; Berg, Joel

    2002-07-01

    Dental researchers have only recently begun to regard dental plaque as a biofilm. Dental plaque biofilm is a complex, heterogeneous structure of bacteria cells, a sticky extracellular matrix, and fluid channels. The biofilm must be modeled accurately for laboratory studies to be meaningful. To that end, researchers have compared the sonicare toothbrush to the Braun Oral-B 3D Excel Plaque Remover for the removal of interproximal dental plaque biofilm in an in vitro model. This article defines the concept of biofilms in the oral cavity and reviews how biofilm modeling is showing differences in toothbrush performance.

  8. Making a Lightweight Battery Plaque

    NASA Technical Reports Server (NTRS)

    Reid, M. A.; Post, R. E.; Soltis, D.

    1986-01-01

    Plaque formed in porous plastic by electroless plating. Lightweight plaque prepared by electroless plating of porous plastic contains embedded wire or expanded metal grid. Plastic may or may not be filled with soluble pore former. If it contains soluble pore former, treated to remove soluble pore former and increase porosity. Porous plastic then clamped into rig that allows plating solutions to flow through plastic. Lightweight nickel plaque used as electrode substrate for alkaline batteries, chiefly Ni and Cd electrodes, and for use as electrolyte-reservoir plates for fuel cells.

  9. Disappearance of La Caille Plaque

    NASA Astrophysics Data System (ADS)

    2010-04-01

    A bronze plaque erected to the memory of N.-L. de La Caille near the site of his observatory in Central Cape Town, has been stolen by metal thieves. It was designed by the famous architect Sir Herbert Baker.

  10. Detection of Rupture-Prone Atherosclerotic Plaques by Time-Resolved Laser Induced Fluorescence Spectroscopy

    PubMed Central

    Marcu, Laura; Jo, Javier A.; Fang, Qiyin; Papaioannou, Thanassis; Reil, Todd; Qiao, Jian-Hua; Baker, J. Dennis; Freischlag, Julie A.; Fishbein, Michael C.

    2009-01-01

    Objective Plaque with dense inflammatory cells, including macrophages, thin fibrous cap and superficial necrotic/lipid core is thought to be prone-to-rupture. We report a time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) technique for detection of such markers of plaque vulnerability in human plaques. Methods The autofluorescence of carotid plaques (65 endarterectomy patients) induced by a pulsed laser (337 nm, 0.7 ns) was measured from 831 distinct areas. The emission was resolved spectrally- (360–550 nm range) and temporally- (0.3 ns resolution) using a prototype fiber-optic TR-LIFS apparatus. Lesions were evaluated microscopically and quantified as to the % of different components (fibrous cap, necrotic core, inflammatory cells, foam cells, mature and degraded collagen, elastic fibers, calcification, and smooth muscle cell of the vessel wall). Results We determined that the spectral intensities and time-dependent parameters at discrete emission wavelengths 1) allow for discrimination (sensitivity >81%, specificity >94%) of various compositional and pathological features associated with plaque vulnerability including infiltration of macrophages into intima and necrotic/lipid core under a thin fibrous cap, and 2) show a linear correlation with plaque biochemical content: elastin (P<0.008), collagen (P<0.02), inflammatory cells (P<0.003), necrosis (P<0.004). Conclusion Our results demonstrate the feasibility of TR-LIFS as a method for the identification of markers of plaque vulnerability. Current findings enable future development of TR-LIFS based clinical devices for rapid investigation of atherosclerotic plaques and detection of those at high-risk. PMID:18926540

  11. Characterising human atherosclerotic carotid plaque tissue composition and morphology using combined spectroscopic and imaging modalities

    PubMed Central

    2015-01-01

    Calcification is a marked pathological component in carotid artery plaque. Studies have suggested that calcification may induce regions of high stress concentrations therefore increasing the potential for rupture. However, the mechanical behaviour of the plaque under the influence of calcification is not fully understood. A method of accurately characterising the calcification coupled with the associated mechanical plaque properties is needed to better understand the impact of calcification on the mechanical behaviour of the plaque during minimally invasive treatments. This study proposes a comparison of biochemical and structural characterisation methods of the calcification in carotid plaque specimens to identify plaque mechanical behaviour. Biochemical analysis, by Fourier Transform Infrared (FTIR) spectroscopy, was used to identify the key components, including calcification, in each plaque sample. However, FTIR has a finite penetration depth which may limit the accuracy of the calcification measurement. Therefore, this FTIR analysis was coupled with the identification of the calcification inclusions located internally in the plaque specimen using micro x-ray computed tomography (μX-CT) which measures the calcification volume fraction (CVF) to total tissue content. The tissue characterisation processes were then applied to the mechanical material plaque properties acquired from experimental circumferential loading of human carotid plaque specimen for comparison of the methods. FTIR characterised the degree of plaque progression by identifying the functional groups associated with lipid, collagen and calcification in each specimen. This identified a negative relationship between stiffness and 'lipid to collagen' and 'calcification to collagen' ratios. However, μX-CT results suggest that CVF measurements relate to overall mechanical stiffness, while peak circumferential strength values may be dependent on specific calcification geometries. This study

  12. Mapping elasticity moduli of atherosclerotic plaque in situ via atomic force microscopy.

    PubMed

    Tracqui, Philippe; Broisat, Alexis; Toczek, Jackub; Mesnier, Nicolas; Ohayon, Jacques; Riou, Laurent

    2011-04-01

    Several studies have suggested that evolving mechanical stresses and strains drive atherosclerotic plaque development and vulnerability. Especially, stress distribution in the plaque fibrous capsule is an important determinant for the risk of vulnerable plaque rupture. Knowledge of the stiffness of atherosclerotic plaque components is therefore of critical importance. In this work, force mapping experiments using atomic force microscopy (AFM) were conducted in apolipoprotein E-deficient (ApoE(-/-)) mouse, which represents the most widely used experimental model for studying mechanisms underlying the development of atherosclerotic lesions. To obtain the elastic material properties of fibrous caps and lipidic cores of atherosclerotic plaques, serial cross-sections of aortic arch lesions were probed at different sites. Atherosclerotic plaque sub-structures were subdivided into cellular fibrotic, hypocellular fibrotic and lipidic rich areas according to histological staining. Hertz's contact mechanics were used to determine elasticity (Young's) moduli that were related to the underlying histological plaque structure. Cellular fibrotic regions exhibit a mean Young modulus of 10.4±5.7kPa. Hypocellular fibrous caps were almost six-times stiffer, with average modulus value of 59.4±47.4kPa, locally rising up to ∼250kPa. Lipid rich areas exhibit a rather large range of Young's moduli, with average value of 5.5±3.5kPa. Such precise quantification of plaque stiffness heterogeneity will allow investigators to have prospectively a better monitoring of atherosclerotic disease evolution, including arterial wall remodeling and plaque rupture, in response to mechanical constraints imposed by vascular shear stress and blood pressure.

  13. Aldehyde dehydrogenase 2 inhibits inflammatory response and regulates atherosclerotic plaque

    PubMed Central

    Wei, Shu-jian; Zhang, Ming-xiang; Wang, Xu-ping; Yuan, Qiu-huan; Xue, Li; Wang, Jia-li; Cui, Zhao-qiang; Zhang, Yun; Xu, Feng; Chen, Yu-guo

    2016-01-01

    Previous studies demonstrated that aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, which eliminates ALDH2 activity down to 1%-6%, is a susceptibility gene for coronary disease. Here we investigated the underlying mechanisms based on our prior clinical and experimental studies. Male apoE−/− mice were transfected with GFP, ALDH2-overexpression and ALDH2-RNAi lentivirus respectively (n=20 each) after constrictive collars were placed around the right common carotid arteries. Consequently, ALDH2 gene silencing led to an increased en face plaque area, more unstable plaque with heavier accumulation of lipids, more macrophages, less smooth muscle cells and collagen, which were associated with aggravated inflammation. However, ALDH2 overexpression displayed opposing effects. We also found that ALDH2 activity decreased in atherosclerotic plaques of human and aged apoE−/− mice. Moreover, in vitro experiments with human umbilical vein endothelial cells further illustrated that, inhibition of ALDH2 activity resulted in elevating inflammatory molecules, an increase of nuclear translocation of NF-κB, and enhanced phosphorylation of NF-κB p65, AP-1 c-Jun, Jun-N terminal kinase and p38 MAPK, while ALDH2 activation could trigger contrary effects. These findings suggested that ALDH2 can influence plaque development and vulnerability, and inflammation via MAPK, NF-κB and AP-1 signaling pathways. PMID:27191745

  14. Evaluation of combined near-IR spectroscopic (NIRS)-IVUS imaging as a means to detect lipid-rich plaque burden in human coronary autopsy specimens

    NASA Astrophysics Data System (ADS)

    Su, Jimmy L.; Grainger, Stephanie J.; Greiner, Cherry A.; Hendricks, Michael J.; Goode, Meghan M.; Saybolt, Matthew D.; Wilensky, Robert L.; Madden, Sean P.; Muller, James E.

    2016-02-01

    Intracoronary near-infrared spectroscopy (NIRS) can identify lipid in the coronary arteries, but lacks depth resolution. A novel catheter is currently in clinical use that combines NIRS with intravascular ultrasound (IVUS), which provides depth-resolved structural information via the IVUS modality. A measure designated as lipid-rich plaque burden (LRPB) has been proposed as a means to interpret the combined acoustic and optical information of NIRS-IVUS. LRPB is defined as the area created by the intersection of the NIRS lipid-rich arc with the corresponding IVUS-measured plaque burden. We determined the correlation in human coronary autopsy specimens between LRPB, a measure of lipid presence and extent available via intravascular imaging in patients, and the area of lipid-rich plaque as determined by the gold-standard of histology. Fifteen artery segments from 8 human autopsy hearts were imaged with the NIRS-IVUS system (TVC Imaging System, Infraredx Inc., Burlington, MA). Arteries were imaged in a specialty fixture that assured accurate co-registration between imaging and histology. The arteries were then fixed and divided into 2 mm blocks for histological staining. Pathological contouring of lipid-rich areas was performed on the stained thin sections for 54 lipid-rich blocks. Computation of LRPB was performed on transverse NIRS-IVUS frames corresponding to the histologic sections. The quantified LRPB was frequently higher than the lipid-rich plaque area determined by histology, because the region denoted by the EEL and lumen within the NIRS lipid-rich arc is not entirely comprised of lipid. Overall, a moderate to strong correlation (R = 0.73) was found between LRPB determined by NIRS-IVUS imaging and the lipid-rich plaque area determined by histology. LRPB, which can be measured in patients with NIRS-IVUS imaging, corresponds to the amount of lipid-rich plaque in a coronary artery. LRPB should be evaluated in prospective clinical trials for its ability to

  15. Anti‐Inflammatory Immune Skewing Is Atheroprotective: Apoe−/−FcγRIIb−/− Mice Develop Fibrous Carotid Plaques

    PubMed Central

    Harmon, Erin Y.; Fronhofer, Van; Keller, Rebecca S.; Feustel, Paul J.; Zhu, Xinmei; Xu, Hao; Avram, Dorina; Jones, David M.; Nagarajan, Shanmugam; Lennartz, Michelle R.

    2014-01-01

    Background Stroke, caused by carotid plaque rupture, is a major cause of death in the United States. Whereas vulnerable human plaques have higher Fc receptor (FcγR) expression than their stable counterparts, how FcγR expression impacts plaque histology is unknown. We investigated the role of FcγRIIb in carotid plaque development and stability in apolipoprotein (Apo)e−/− and Apoe−/−FcγRIIb−/− double knockout (DKO) animals. Methods and Results Plaques were induced by implantation of a shear stress‐modifying cast around the carotid artery. Plaque length and stenosis were followed longitudinally using ultrasound biomicroscopy. Immune status was determined by flow cytometry, cytokine release, immunoglobulin G concentration and analysis of macrophage polarization both in plaques and in vitro. Surprisingly, DKO animals had lower plaque burden in both carotid artery and descending aorta. Plaques from Apoe−/− mice were foam‐cell rich and resembled vulnerable human specimens, whereas those from DKO mice were fibrous and histologically stable. Plaques from DKO animals expressed higher arginase 1 (Arg‐1) and lower inducible nitric oxide synthase (iNOS), indicating the presence of M2 macrophages. Analysis of blood and cervical lymph nodes revealed higher interleukin (IL)‐10, immune complexes, and regulatory T cells (Tregs) and lower IL‐12, IL‐1β, and tumor necrosis factor alpha (TNF‐α) in DKO mice. Similarly, in vitro stimulation produced higher IL‐10 and Arg‐1 and lower iNOS, IL‐1β, and TNF‐α in DKO versus Apoe−/− macrophages. These results define a systemic anti‐inflammatory phenotype. Conclusions We hypothesized that removal of FcγRIIb would exacerbate atherosclerosis and generate unstable plaques. However, we found that deletion of FcγRIIb on a congenic C57BL/6 background induces an anti‐inflammatory Treg/M2 polarization that is atheroprotective. PMID:25516435

  16. Plaque hemorrhage in carotid artery disease: Pathogenesis, clinical and biomechanical considerations

    PubMed Central

    Teng, Zhongzhao; Sadat, Umar; Brown, Adam J.; Gillard, Jonathan H.

    2014-01-01

    Stroke remains the most prevalent disabling illness today, with internal carotid artery luminal stenosis due to atheroma formation responsible for the majority of ischemic cerebrovascular events. Severity of luminal stenosis continues to dictate both patient risk stratification and the likelihood of surgical intervention. But there is growing evidence to suggest that plaque morphology may help improve pre-existing risk stratification criteria. Plaque components such a fibrous tissue, lipid rich necrotic core and calcium have been well investigated but plaque hemorrhage (PH) has been somewhat overlooked. In this review we discuss the pathogenesis of PH, its role in dictating plaque vulnerability, PH imaging techniques, marterial properties of atherosclerotic tissues, in particular, those obtained based on in vivo measurements and effect of PH in modulating local biomechanics. PMID:24485514

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

    PubMed

    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.

  18. Shear wave elastography plaque characterization with mechanical testing validation: a phantom study

    NASA Astrophysics Data System (ADS)

    Widman, E.; Maksuti, E.; Larsson, D.; Urban, M. W.; Bjällmark, A.; Larsson, M.

    2015-04-01

    Determining plaque vulnerability is critical when selecting the most suitable treatment for patients with atherosclerotic plaque. Currently, clinical non-invasive ultrasound-based methods for plaque characterization are limited to visual assessment of plaque morphology and new quantitative methods are needed. In this study, shear wave elastography (SWE) was used to characterize hard and soft plaque mimicking inclusions in six common carotid artery phantoms by using phase velocity analysis in static and dynamic environments. The results were validated with mechanical tensile testing. In the static environment, SWE measured a mean shear modulus of 5.8  ±  0.3 kPa and 106.2  ±  17.2 kPa versus 3.3  ±  0.5 kPa and 98.3  ±  3.4 kPa measured by mechanical testing in the soft and hard plaques respectively. Furthermore, it was possible to measure the plaques’ shear moduli throughout a simulated cardiac cycle. The results show good agreement between SWE and mechanical testing and indicate the possibility for in vivo arterial plaque characterization using SWE.

  19. Integrated IVUS-OCT Imaging for Atherosclerotic Plaque Characterization

    PubMed Central

    Li, Xiang; Li, Jiawen; Jing, Joe; Ma, Teng; Liang, Shanshan; Zhang, Jun; Mohar, Dilbahar; Raney, Aidan; Mahon, Sari; Brenner, Matthew; Patel, Pranav; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping

    2014-01-01

    For the diagnosis of atherosclerosis, biomedical imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed. The combined use of IVUS and OCT is hypothesized to remarkably increase diagnostic accuracy of vulnerable plaques. We have developed an integrated IVUS-OCT imaging apparatus, which includes the integrated catheter, motor drive unit, and imaging system. The dual-function imaging catheter has the same diameter of current clinical standard. The imaging system is capable for simultaneous IVUS and OCT imaging in real time. Ex vivo and in vivo experiments on rabbits with atherosclerosis were conducted to demonstrate the feasibility and superiority of the integrated intravascular imaging modality. PMID:24771992

  20. Inhibiting macrophage proliferation suppresses atherosclerotic plaque inflammation.

    PubMed

    Tang, Jun; Lobatto, Mark E; Hassing, Laurien; van der Staay, Susanne; van Rijs, Sarian M; Calcagno, Claudia; Braza, Mounia S; Baxter, Samantha; Fay, Francois; Sanchez-Gaytan, Brenda L; Duivenvoorden, Raphaël; Sager, Hendrik; Astudillo, Yaritzy M; Leong, Wei; Ramachandran, Sarayu; Storm, Gert; Pérez-Medina, Carlos; Reiner, Thomas; Cormode, David P; Strijkers, Gustav J; Stroes, Erik S G; Swirski, Filip K; Nahrendorf, Matthias; Fisher, Edward A; Fayad, Zahi A; Mulder, Willem J M

    2015-04-01

    Inflammation drives atherosclerotic plaque progression and rupture, and is a compelling therapeutic target. Consequently, attenuating inflammation by reducing local macrophage accumulation is an appealing approach. This can potentially be accomplished by either blocking blood monocyte recruitment to the plaque or increasing macrophage apoptosis and emigration. Because macrophage proliferation was recently shown to dominate macrophage accumulation in advanced plaques, locally inhibiting macrophage proliferation may reduce plaque inflammation and produce long-term therapeutic benefits. To test this hypothesis, we used nanoparticle-based delivery of simvastatin to inhibit plaque macrophage proliferation in apolipoprotein E deficient mice (Apoe(-/-) ) with advanced atherosclerotic plaques. This resulted in rapid reduction of plaque inflammation and favorable phenotype remodeling. We then combined this short-term nanoparticle intervention with an eight-week oral statin treatment, and this regimen rapidly reduced and continuously suppressed plaque inflammation. Our results demonstrate that pharmacologically inhibiting local macrophage proliferation can effectively treat inflammation in atherosclerosis.

  1. Inhibiting macrophage proliferation suppresses atherosclerotic plaque inflammation

    PubMed Central

    Tang, Jun; Lobatto, Mark E.; Hassing, Laurien; van der Staay, Susanne; van Rijs, Sarian M.; Calcagno, Claudia; Braza, Mounia S.; Baxter, Samantha; Fay, Francois; Sanchez-Gaytan, Brenda L.; Duivenvoorden, Raphaël; Sager, Hendrik B.; Astudillo, Yaritzy M.; Leong, Wei; Ramachandran, Sarayu; Storm, Gert; Pérez-Medina, Carlos; Reiner, Thomas; Cormode, David P.; Strijkers, Gustav J.; Stroes, Erik S. G.; Swirski, Filip K.; Nahrendorf, Matthias; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

    2015-01-01

    Inflammation drives atherosclerotic plaque progression and rupture, and is a compelling therapeutic target. Consequently, attenuating inflammation by reducing local macrophage accumulation is an appealing approach. This can potentially be accomplished by either blocking blood monocyte recruitment to the plaque or increasing macrophage apoptosis and emigration. Because macrophage proliferation was recently shown to dominate macrophage accumulation in advanced plaques, locally inhibiting macrophage proliferation may reduce plaque inflammation and produce long-term therapeutic benefits. To test this hypothesis, we used nanoparticle-based delivery of simvastatin to inhibit plaque macrophage proliferation in apolipoprotein E–deficient mice (Apoe−/−) with advanced atherosclerotic plaques. This resulted in the rapid reduction of plaque inflammation and favorable phenotype remodeling. We then combined this short-term nanoparticle intervention with an 8-week oral statin treatment, and this regimen rapidly reduced and continuously suppressed plaque inflammation. Our results demonstrate that pharmacologically inhibiting local macrophage proliferation can effectively treat inflammation in atherosclerosis. PMID:26295063

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

    PubMed Central

    Hua, Ning; Baik, Fred; Pham, Tuan; Phinikaridou, Alkystis; Giordano, Nick; Friedman, Beth; Whitney, Michael; Nguyen, Quyen T.; Tsien, Roger Y.; Hamilton, James A.

    2015-01-01

    Introduction 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. Methods and Results 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. Conclusions 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. PMID:26448434

  3. Viral Concentration Determination Through Plaque Assays: Using Traditional and Novel Overlay Systems

    PubMed Central

    Baer, Alan; Kehn-Hall, Kylene

    2014-01-01

    Plaque assays remain one of the most accurate methods for the direct quantification of infectious virons and antiviral substances through the counting of discrete plaques (infectious units and cellular dead zones) in cell culture. Here we demonstrate how to perform a basic plaque assay, and how differing overlays and techniques can affect plaque formation and production. Typically solid or semisolid overlay substrates, such as agarose or carboxymethyl cellulose, have been used to restrict viral spread, preventing indiscriminate infection through the liquid growth medium. Immobilized overlays restrict cellular infection to the immediately surrounding monolayer, allowing the formation of discrete countable foci and subsequent plaque formation. To overcome the difficulties inherent in using traditional overlays, a novel liquid overlay utilizing microcrystalline cellulose and carboxymethyl cellulose sodium has been increasingly used as a replacement in the standard plaque assay. Liquid overlay plaque assays can be readily performed in either standard 6 or 12 well plate formats as per traditional techniques and require no special equipment. Due to its liquid state and subsequent ease of application and removal, microculture plate formats may alternatively be utilized as a rapid, accurate and high throughput alternative to larger scale viral titrations. Use of a non heated viscous liquid polymer offers the opportunity to streamline work, conserves reagents, incubator space, and increases operational safety when used in traditional or high containment labs as no reagent heating or glassware are required. Liquid overlays may also prove more sensitive than traditional overlays for certain heat labile viruses. PMID:25407402

  4. Endoscopic fluorescence lifetime imaging microscopy (FLIM) images of aortic plaque: an automated classification method

    NASA Astrophysics Data System (ADS)

    Phipps, Jennifer; Sun, Yinghua; Hatami, Nisa; Fishbein, Michael C.; Rajaram, Amit; Saroufeem, Ramez; Marcu, Laura

    2010-02-01

    The objective of this study was to develop an automated algorithm which uses fluorescence lifetime imaging microscopy (FLIM) images of human aortic atherosclerotic plaque to provide quantitative and spatial information regarding compositional features related to plaque vulnerability such as collagen degradation, lipid accumulation, and macrophage infiltration. Images were acquired through a flexible fiber imaging bundle with intravascular potential at two wavelength bands optimal to recognizing markers of vulnerability: F377: 377/55 nm and F460: 460/50 nm (center wavelength/bandwidth). A classification method implementing principal components analysis and linear discriminant analysis to correlate FLIM data sets with histopathology was validated on a training set and then used to classify a validation set of FLIM images. The output of this algorithm was a false-color image with each pixel color coded to represent the chemical composition of the sample. Surface areas occupied by elastin, collagen, and lipid components were then calculated and used to define the vulnerability of each imaged location. Four groups were defined: early lesion, stable, mildly vulnerable and extremely vulnerable. Each imaged location was categorized in one of the groups based on histopathology and classification results; sensitivities (SE) and specificities (SP) were calculated (SE %/SP %): early lesion: 95/96, stable: 71/97, mildly vulnerable: 75/94, and extremely vulnerable: 100/93. The capability of this algorithm to use FLIM images to quickly determine the chemical composition of atherosclerotic plaque, particularly related to vulnerability, further enhances the potential of this system for implementation as an intravascular diagnostic modality.

  5. The roles of myeloperoxidase in coronary artery disease and its potential implication in plaque rupture.

    PubMed

    Teng, Nathaniel; Maghzal, Ghassan J; Talib, Jihan; Rashid, Imran; Lau, Antony K; Stocker, Roland

    2017-03-01

    Atherosclerosis is the main pathophysiological process underlying coronary artery disease (CAD). Acute complications of atherosclerosis, such as myocardial infarction, are caused by the rupture of vulnerable atherosclerotic plaques, which are characterized by thin, highly inflamed, and collagen-poor fibrous caps. Several lines of evidence mechanistically link the heme peroxidase myeloperoxidase (MPO), inflammation as well as acute and chronic manifestations of atherosclerosis. MPO and MPO-derived oxidants have been shown to contribute to the formation of foam cells, endothelial dysfunction and apoptosis, the activation of latent matrix metalloproteinases, and the expression of tissue factor that can promote the development of vulnerable plaque. As such, detection, quantification and imaging of MPO mass and activity have become useful in cardiac risk stratification, both for disease assessment and in the identification of patients at risk of plaque rupture. This review summarizes the current knowledge about the role of MPO in CAD with a focus on its possible roles in plaque rupture and recent advances to quantify and image MPO in plasma and atherosclerotic plaques.

  6. Vulnerability Evaluation Framework

    EPA Pesticide Factsheets

    View the Vulnerability Evaluation Framework, which provides policy-makers, stakeholders, industry, and the public with a transparent framework to evaluate vulnerabilities associated with geologic sequestration sites.

  7. Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque

    SciTech Connect

    Saba, Luca; Potters, Fons; Lugt, Aad van der; Mallarini, Giorgio

    2010-08-15

    In the last two decades, a substantial number of articles have been published to provide diagnostic solutions for patients with carotid atherosclerotic disease. These articles have resulted in a shift of opinion regarding the identification of stroke risk in patients with carotid atherosclerotic disease. In the recent past, the degree of carotid artery stenosis was the sole determinant for performing carotid intervention (carotid endarterectomy or carotid stenting) in these patients. We now know that the degree of stenosis is only one marker for future cerebrovascular events. If one wants to determine the risk of these events more accurately, other parameters must be taken into account; among these parameters are plaque composition, presence and state of the fibrous cap (FC), intraplaque haemorrhage, plaque ulceration, and plaque location. In particular, the FC is an important structure for the stability of the plaque, and its rupture is highly associated with a recent history of transient ischaemic attack or stroke. The subject of this review is imaging of the FC.

  8. Numerical observer for atherosclerotic plaque classification in spectral computed tomography.

    PubMed

    Lorsakul, Auranuch; Fakhri, Georges El; Worstell, William; Ouyang, Jinsong; Rakvongthai, Yothin; Laine, Andrew F; Li, Quanzheng

    2016-07-01

    Spectral computed tomography (SCT) generates better image quality than conventional computed tomography (CT). It has overcome several limitations for imaging atherosclerotic plaque. However, the literature evaluating the performance of SCT based on objective image assessment is very limited for the task of discriminating plaques. We developed a numerical-observer method and used it to assess performance on discrimination vulnerable-plaque features and compared the performance among multienergy CT (MECT), dual-energy CT (DECT), and conventional CT methods. Our numerical observer was designed to incorporate all spectral information and comprised two-processing stages. First, each energy-window domain was preprocessed by a set of localized channelized Hotelling observers (CHO). In this step, the spectral image in each energy bin was decorrelated using localized prewhitening and matched filtering with a set of Laguerre-Gaussian channel functions. Second, the series of the intermediate scores computed from all the CHOs were integrated by a Hotelling observer with an additional prewhitening and matched filter. The overall signal-to-noise ratio (SNR) and the area under the receiver operating characteristic curve (AUC) were obtained, yielding an overall discrimination performance metric. The performance of our new observer was evaluated for the particular binary classification task of differentiating between alternative plaque characterizations in carotid arteries. A clinically realistic model of signal variability was also included in our simulation of the discrimination tasks. The inclusion of signal variation is a key to applying the proposed observer method to spectral CT data. Hence, the task-based approaches based on the signal-known-exactly/background-known-exactly (SKE/BKE) framework and the clinical-relevant signal-known-statistically/background-known-exactly (SKS/BKE) framework were applied for analytical computation of figures of merit (FOM). Simulated data of a

  9. Lipid volume fraction in atherosclerotic plaque phantoms classified under saline conditions by multispectral angioscopy at near-infrared wavelengths around 1200 nm.

    PubMed

    Matsui, Daichi; Ishii, Katsunori; Awazu, Kunio

    2016-05-01

    To identify high-risk atherosclerotic lesions, we require detailed information on the stability of atherosclerotic plaques. In this study, we quantitatively classified the lipid volume fractions in atherosclerotic plaque phantoms by a novel angioscope combined with near-infrared multispectral imaging. The multispectral angioscope was operated at peak absorption wavelengths of lipid in vulnerable plaques (1150, 1200, and 1300 nm) and at lower absorption wavelengths of water. The potential of the multispectral angioscope was demonstrated in atherosclerotic plaque phantoms containing 10-60 vol.% lipid and immersed in saline solution. The acquired multispectral data were processed by a spectral angle mapper algorithm, which enhanced the simulated plaque areas. Consequently, we classified the lipid volume fractions into five categories (0-5, 5-15, 15-30, 30-50, and 50-60 vol.%). Multispectral angioscopy at wavelengths around 1200 nm is a powerful tool for quantitatively evaluating the stability of atherosclerotic plaques based on the lipid volume fractions.

  10. Multimodality Intravascular Imaging Assessment of Plaque Erosion versus Plaque Rupture in Patients with Acute Coronary Syndrome

    PubMed Central

    Kwon, Jee Eun; Mintz, Gary S.; Hong, Young Joon; Lee, Sung Yun; Kim, Ki Seok; Hahn, Joo-Yong; Kumar, Kaup Sharath; Won, Hoyoun; Hyeon, Seong Hyeop; Shin, Seung Yong; Lee, Kwang Je; Kim, Tae Ho; Kim, Chee Jeong; Kim, Sang Wook

    2016-01-01

    Background and Objectives We assessed plaque erosion of culprit lesions in patients with acute coronary syndrome in real world practice. Subjects and Methods Culprit lesion plaque rupture or plaque erosion was diagnosed with optical coherence tomography (OCT). Intravascular ultrasound (IVUS) was used to determine arterial remodeling. Positive remodeling was defined as a remodeling index (lesion/reference EEM [external elastic membrane area) >1.05. Results A total of 90 patients who had plaque rupture showing fibrous-cap discontinuity and ruptured cavity were enrolled. 36 patients showed definite OCT-plaque erosion, while 7 patients had probable OCT-plaque erosion. Overall, 26% (11/43) of definite/probable plaque erosion had non-ST elevation myocardial infarction (NSTEMI) while 35% (15/43) had ST elevation myocardial infarction (STEMI). Conversely, 14.5% (13/90) of plaque rupture had NSTEMI while 71% (64/90) had STEMI (p<0.0001). Among plaque erosion, white thrombus was seen in 55.8% (24/43) of patients and red thrombus in 27.9% (12/43) of patients. Compared to plaque erosion, plaque rupture more often showed positive remodeling (p=0.003) with a larger necrotic core area examined by virtual histology (VH)-IVUS, while negative remodeling was prominent in plaque erosion. Overall, 65% 28/43 of plaque erosions were located in the proximal 30 mm of a culprit vessel-similar to plaque ruptures (72%, 65/90, p=0.29). Conclusion Although most of plaque erosions show nearly normal coronary angiogram, modest plaque burden with negative remodeling and an uncommon fibroatheroma might be the nature of plaque erosion. Multimodality intravascular imaging with OCT and VH-IVUS showed fundamentally different pathoanatomic substrates underlying plaque rupture and erosion. PMID:27482258

  11. Atherosclerotic plaque regression: fact or fiction?

    PubMed

    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.

  12. [Is regression of atherosclerotic plaque possible?

    PubMed

    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.

  13. The effects of plaque morphology and material properties on peak cap stress in human coronary arteries.

    PubMed

    Akyildiz, Ali C; Speelman, Lambert; Nieuwstadt, Harm A; van Brummelen, Harald; Virmani, Renu; van der Lugt, Aad; van der Steen, Anton F W; Wentzel, Jolanda J; Gijsen, Frank J H

    2016-01-01

    Heart attacks are often caused by rupture of caps of atherosclerotic plaques in coronary arteries. Cap rupture occurs when cap stress exceeds cap strength. We investigated the effects of plaque morphology and material properties on cap stress. Histological data from 77 coronary lesions were obtained and segmented. In these patient-specific cross sections, peak cap stresses were computed by using finite element analyses. The finite element analyses were 2D, assumed isotropic material behavior, and ignored residual stresses. To represent the wide spread in material properties, we applied soft and stiff material models for the intima. Measures of geometric plaque features for all lesions were determined and their relations to peak cap stress were examined using regression analyses. Patient-specific geometrical plaque features greatly influence peak cap stresses. Especially, local irregularities in lumen and necrotic core shape as well as a thin intima layer near the shoulder of the plaque induce local stress maxima. For stiff models, cap stress increased with decreasing cap thickness and increasing lumen radius (R = 0.79). For soft models, this relationship changed: increasing lumen radius and increasing lumen curvature were associated with increased cap stress (R = 0.66). The results of this study imply that not only accurate assessment of plaque geometry, but also of intima properties is essential for cap stress analyses in atherosclerotic plaques in human coronary arteries.

  14. 3D carotid plaque MR Imaging

    PubMed Central

    Parker, Dennis L.

    2015-01-01

    SYNOPSIS There has been significant progress made in 3D carotid plaque magnetic resonance imaging techniques in recent years. 3D plaque imaging clearly represents the future in clinical use. With effective flow suppression techniques, choices of different contrast weighting acquisitions, and time-efficient imaging approaches, 3D plaque imaging offers flexible imaging plane and view angle analysis, large coverage, multi-vascular beds capability, and even can be used in fast screening. PMID:26610656

  15. Automatic detection of plaques with severe stenosis in coronary vessels of CT angiography

    NASA Astrophysics Data System (ADS)

    Dinesh, M. S.; Devarakota, Pandu; Kumar, Jitendra

    2010-03-01

    Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of coronary arteries and is the leading cause of death worldwide. Computed tomography angiography (CTA) has been proved to be very useful for accurate noninvasive diagnosis and quantification of plaques. However, the existing methods to measure the stenosis in the plaques are not accurate enough in mid and distal segments where the vessels become narrower. To alleviate this, we propose a method that consists of three stages namely, automatic extraction of coronary vessels; vessels straightening; lumen extraction and stenosis evaluation. In the first stage, the coronary vessels are segmented using a parametric approach based on circular vessel model at each point on the centerline. It is assumed that centerline information is available in advance. Vessel straightening in the second stage performs multi-planar reformat (MPR) to straighten the curved vessels. MPR view of a vessel helps to visualize and measure the plaques better. On the straightened vessel, lumen and vessel wall are segregated using a nearest neighbor classification. To detect the plaques with severe stenosis in the vessel lumen, we propose a "Diameter Luminal Stenosis" method for analyzing the smaller segments of the vessel. Proposed measurement technique identifies the segments that have plaques and reports the top three severely stenosed segments. Proposed algorithm is applied on 24 coronary vessels belonging to multiple cases acquired from Sensation 64 - slice CT and initial results are promising.

  16. An imbalance between specialized pro-resolving lipid mediators and pro-inflammatory leukotrienes promotes instability of atherosclerotic plaques

    PubMed Central

    Fredman, Gabrielle; Hellmann, Jason; Proto, Jonathan D.; Kuriakose, George; Colas, Romain A.; Dorweiler, Bernhard; Connolly, E. Sander; Solomon, Robert; Jones, David M.; Heyer, Eric J.; Spite, Matthew; Tabas, Ira

    2016-01-01

    Chronic unresolved inflammation plays a causal role in the development of advanced atherosclerosis, but the mechanisms that prevent resolution in atherosclerosis remain unclear. Here, we use targeted mass spectrometry to identify specialized pro-resolving lipid mediators (SPM) in histologically-defined stable and vulnerable regions of human carotid atherosclerotic plaques. The levels of SPMs, particularly resolvin D1 (RvD1), and the ratio of SPMs to pro-inflammatory leukotriene B4 (LTB4), are significantly decreased in the vulnerable regions. SPMs are also decreased in advanced plaques of fat-fed Ldlr−/− mice. Administration of RvD1 to these mice during plaque progression restores the RvD1:LTB4 ratio to that of less advanced lesions and promotes plaque stability, including decreased lesional oxidative stress and necrosis, improved lesional efferocytosis, and thicker fibrous caps. These findings provide molecular support for the concept that defective inflammation resolution contributes to the formation of clinically dangerous plaques and offer a mechanistic rationale for SPM therapy to promote plaque stability. PMID:27659679

  17. [From myocardium to the atherosclerotic plaque: new perspectives in cardiologic imaging].

    PubMed

    Gargiulo, Paola; D'Amore, Carmen; Dellegrottaglie, Santo; Leosco, Dario; Rengo, Giuseppe; Musella, Francesca; Pirozzi, Elisabetta; Mosca, Susanna; Casaretti, Laura; Formisano, Roberto; Bologna, Ada; Parente, Antonio; Conte, Sirio; Perrone-Filardi, Pasquale

    2011-06-01

    Molecular imaging is an innovative and promising approach in cardiology for functional characterization of atherosclerosis. Nuclear, ultrasound and magnetic resonance imaging have been used for assessment of atherosclerosis of large and small arteries in several clinical and experimental studies. Positron Emission Tomography with fluorodeoxyglucose can measure metabolic activity and vulnerability of atherosclerotic plaques, identifying individuals at risk of future cardiovascular events. Magnetic resonance imaging can quantify carotid artery inflammation using iron oxide nanoparticles as contrast agent. In addition, macrophage accumulation of iron particles in atherosclerotic plaques may allow monitoring of inflammation during drug therapy, whereas contrast-enhanced ultrasound imaging may detect plaque neovascularization. Currently, technical factors, including cardiac and diaphragmatic motion and small size of coronary vessels, limit routine application of these techniques for coronary imaging. Purpose of this review is to describe state of the art and potential areas of clinical applications of molecular imaging of atherosclerosis.

  18. Challenges on the frontier of intracoronary imaging: atherosclerotic plaque macrophage measurement by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Tanaka, Atsushi; Tearney, Guillermo J.; Bouma, Brett E.

    2010-01-01

    Cellularity of the fibrous caps of coronary atheromas, manifested by the infiltration of macrophages (average size, 20 to 30 μm), is thought to weaken the structural integrity of the cap and predispose plaques to rupture. Therefore, an imaging technology capable of identifying macrophages within fibroatheroma caps in patients could provide valuable information for assessing plaque rupture risk. Recently, intravascular optical coherence tomography (OCT), a high-resolution coronary imaging modality, with an axial resolution of ~10 μm, has been introduced into the clinical setting. OCT images of the microstructure of the coronary artery wall enable accurate plaque-type characterization, supported by histopathological comparison data. Because of its high resolution, OCT may also be used to identify macrophages in vivo. In this paper we review recent developments in OCT for measuring macrophages in atherosclerotic plaques.

  19. Quantitative evaluation of atherosclerotic plaques using cross-polarization optical coherence tomography, nonlinear, and atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Gubarkova, Ekaterina V.; Kirillin, Mikhail Yu.; Dudenkova, Varvara V.; Timashev, Peter S.; Kotova, Svetlana L.; Kiseleva, Elena B.; Timofeeva, Lidia B.; Belkova, Galina V.; Solovieva, Anna B.; Moiseev, Alexander A.; Gelikonov, Gregory V.; Fiks, Ilya I.; Feldchtein, Felix I.; Gladkova, Natalia D.

    2016-12-01

    A combination of approaches to the image analysis in cross-polarization optical coherence tomography (CP OCT) and high-resolution imaging by nonlinear microscopy and atomic force microscopy (AFM) at the different stages of atherosclerotic plaque development is studied. This combination allowed us to qualitatively and quantitatively assess the disorganization of collagen in the atherosclerotic arterial tissue (reduction and increase of CP backscatter), at the fiber (change of the geometric distribution of fibers in the second-harmonic generation microscopy images) and fibrillar (violation of packing and different nature of a basket-weave network of fibrils in the AFM images) organization levels. The calculated CP channel-related parameters are shown to have a statistically significant difference between stable and unstable (also called vulnerable) plaques, and hence, CP OCT could be a potentially powerful, minimally invasive method for vulnerable plaques detection.

  20. Software Vulnerability Taxonomy Consolidation

    SciTech Connect

    Polepeddi, Sriram S.

    2004-12-07

    In today's environment, computers and networks are increasing exposed to a number of software vulnerabilities. Information about these vulnerabilities is collected and disseminated via various large publicly available databases such as BugTraq, OSVDB and ICAT. Each of these databases, individually, do not cover all aspects of a vulnerability and lack a standard format among them, making it difficult for end-users to easily compare various vulnerabilities. A central database of vulnerabilities has not been available until today for a number of reasons, such as the non-uniform methods by which current vulnerability database providers receive information, disagreement over which features of a particular vulnerability are important and how best to present them, and the non-utility of the information presented in many databases. The goal of this software vulnerability taxonomy consolidation project is to address the need for a universally accepted vulnerability taxonomy that classifies vulnerabilities in an unambiguous manner. A consolidated vulnerability database (CVDB) was implemented that coalesces and organizes vulnerability data from disparate data sources. Based on the work done in this paper, there is strong evidence that a consolidated taxonomy encompassing and organizing all relevant data can be achieved. However, three primary obstacles remain: lack of referencing a common ''primary key'', un-structured and free-form descriptions of necessary vulnerability data, and lack of data on all aspects of a vulnerability. This work has only considered data that can be unambiguously extracted from various data sources by straightforward parsers. It is felt that even with the use of more advanced, information mining tools, which can wade through the sea of unstructured vulnerability data, this current integration methodology would still provide repeatable, unambiguous, and exhaustive results. Though the goal of coalescing all available data, which would be of use to

  1. Plaquing procedure for infectious hematopoietic necrosis virus

    USGS Publications Warehouse

    Burke, J.A.; Mulcahy, D.

    1980-01-01

    A single overlay plaque assay was designed and evaluated for infectious hematopoietic necrosis virus. Epithelioma papillosum carpio cells were grown in normal atmosphere with tris(hydroxymethyl)aminomethane- or HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid)-buffered media. Plaques were larger and formed more quickly on 1- to 3-day-old cell monolayers than on older monolayers. Cell culture medium with a 10% addition of fetal calf serum (MEM 10) or without serum (MEM 0) were the most efficient virus diluents. Dilution with phosphate-buffered saline, saline, normal broth, or deionized water reduced plaque numbers. Variations in the pH (7.0 to 8.0) of a MEM 0 diluent did not affect plaque numbers. Increasing the volume of viral inoculum above 0.15 ml (15- by 60-mm plate) decreased plaquing efficiency. Significantly more plaques occurred under gum tragacanth and methylcellulose than under agar or agarose overlays. Varying the pH (6.8 to 7.4) of methylcellulose overlays did not significantly change plaque numbers. More plaques formed under the thicker overlays of both methylcellulose and gum tragacanth. Tris(hydroxymethyl)aminomethane and HEPES performed equally well, buffering either medium or overlay. Plaque numbers were reduced when cells were rinsed after virus adsorption or less than 1 h was allowed for adsorption. Variation in adsorption time between 60 and 180 min did not change plaque numbers. The mean plaque formation time was 7 days at 16 degrees C. The viral dose response was linear when the standardized assay was used.

  2. Monte Carlo dosimetry for {sup 103}Pd, {sup 125}I, and {sup 131}Cs ocular brachytherapy with various plaque models using an eye phantom

    SciTech Connect

    Lesperance, Marielle; Martinov, M.; Thomson, R. M.

    2014-03-15

    ocular structures are generally delivered with plaques containing {sup 103}Pd seeds. Conclusions: The combined effects of ocular and plaque media on dose are significant and vary with plaque model and radionuclide, suggesting the importance of model-based dose calculations employing accurate ocular and plaque media and geometries for eye plaque brachytherapy.

  3. Intracoronary Near-Infrared Spectroscopy (NIRS) Imaging for Detection of Lipid Content of Coronary Plaques: Current Experience and Future Perspectives.

    PubMed

    Jaguszewski, Milosz; Klingenberg, Roland; Landmesser, Ulf

    2013-01-01

    Acute coronary syndromes are frequently caused by "vulnerable" coronary plaques with a lipid-rich core. In 1993 near-infrared spectroscopy (NIRS) was first used to detect the lipid (cholesterol) content of atherosclerotic plaques in an experimental animal study. NIRS was then carefully validated using human atherosclerotic plaques (ex vivo), and has subsequently been developed for intracoronary imaging in humans, for which now an FDA-approved catheter-based NIRS system is available. NIRS provides a "chemogram" of the coronary artery wall and is used to detect lipid-rich plaques. Using this technology, recent studies have shown that lipid-rich plaques are very frequent in the culprit lesion of patients with an acute coronary syndrome, and are also common in non-culprit coronary lesions in these patients as compared to patients with stable coronary disease. First studies are evaluating the impact of statin therapy on coronary NIRS-detected lipid cores. Intracoronary NIRS imaging represents a highly interesting method for coronary plaque characterization in humans and may become a valuable tool for the development of novel therapies aiming to impact on the biology of human coronary artery plaques, likely in combination with other intracoronary imaging techniques, such as optical coherence tomography.

  4. What Does Vulnerability Mean?

    ERIC Educational Resources Information Center

    Parley, Fiona F

    2011-01-01

    Protection of those deemed vulnerable has received increasing attention since 2000. This article reports on care staff views of vulnerability using original data from a research study (Parley. "Vulnerability and abuse: an exploration of views of care staff working with people who have learning disabilities," PhD Thesis, 2007) in which care staff…

  5. Plaque-based competitive hybridization.

    PubMed

    Villányi, Zoltán; Gyurján, István; Stéger, Viktor; Orosz, László

    2008-01-01

    The authors have developed a simple, cost-saving experimental design, plaque-based competitive hybridization (PBCH), for genome-wide identification of genes differentially expressed in different tissues. PBCH offers advantages in comparison with other methods used in comparative genomics by combining the principles of differential hybridization with the subtractive hybridization. PBCH is particularly advantageous when libraries with few differences are to be analyzed. The authors demonstrate the use of PBCH by identifying 3 genes, up-regulated in the developing velvet antler of red deer (Cervus elaphus): ApoD, C011A2, and S100a1. The fidelity and sensitivity of PBCH is also shown: 1 specific clone among a library sample of 15,000 can be recognized. Possibilities for further utilizations are discussed.

  6. Corneal plaque containing levofloxacin in a dog.

    PubMed

    Park, Young-Woo; Kang, Byung-Jae; Lim, Jae Hyun; Ahn, Jung-Mo; Lim, Hyun Sook

    2015-11-01

    A 13-year-old castrated male Yorkshire terrier developed a corneal ulcer 2 weeks after intracapsular lens extraction (ICLE) in the right eye. The corneal ulcer was treated with levofloxacin eye drops. A plaque with a white luster developed in the central cornea 2 weeks after treatment with levofloxacin eye drops. The corneal plaque was surgically removed under inhalant anesthesia. The corneal plaque displayed antimicrobial activity against Escherichia coli. Furthermore, levofloxacin content in the plaque was confirmed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry (MS). The corneal ulcer completely resolved 2 weeks after the surgical removal of the corneal lesion and replacement of levofloxacin eye drops with tobramycin eye drops. Although the topical use of levofloxacin is unlikely to lead to corneal chemical deposits due to the high water solubility of the drug compared to other topical fluoroquinolones, this patient developed corneal plaque of the antibiotic drop.

  7. Quantification of arterial plaque and lumen density with MDCT

    SciTech Connect

    Paul, Narinder S.; Blobel, Joerg; Kashani, Hany; Rice, Murray; Ursani, Ali

    2010-08-15

    automatically generate a true assessment of measured CT number (HU) corresponding to plaque physical density {rho} (g/cm{sup 3}). This is a significant development for the accurate, noninvasive classification of noncalcified arterial plaque.

  8. Assessment of coronary plaque collagen with polarization sensitive optical coherence tomography (PS-OCT)

    NASA Astrophysics Data System (ADS)

    Giattina, Susanne D.; Courtney, Brian K.; Herz, Paul R.; Harman, Michelle; Shortkroff, Sonya; Stamper, Debra L.; Liu, Bin; Fujimoto, James G.; Brezinski, Mark E.

    2006-02-01

    Current evidence indicates that most plaques classified as vulnerable or ruptured plaques do not lead to unstable angina or myocardial infarction. Improved methods are needed to risk stratify plaques to identify those which lead to most acute coronary syndromes. Collagen depletion in the intima overlying lipid collections appears to be a critical component of unstable plaques. In this study, we use polarization sensitive optical coherence tomography (PS-OCT) for the assessment of coronary plaque collagen. Collagen is birefringent, meaning that different polarization states travel through it at different velocities. Changes in PS-OCT images are a measure of tissue birefringence. Twenty-two coronary artery segments were imaged with PS-OCT and analyzed by picrosirius staining (a measure of collagen intensity and fiber size) and trichrome blue. The regression plot between PS-OCT changes and measured collagen yielded a correlation coefficient value of 0.475 (p<0.002). Good correlation was noted between two blinded investigators both with respect to PS-OCT measurements as well as luminosity as assessed by picrosirius. The predictive value of a PS-OCT measurement of negligible birefringence (less than 33% change) for minimal collagen was 93% while the predictive value of high birefringence (greater than 66% change) for high collagen concentrations was 89%. The effect of fiber type (chemical composition) was minimal relative to the effect due to fiber concentration. The capability of PS-OCT to assess plaque collagen content, in addition to its ability to generate high resolution structural assessments, make it a potentially powerful technology for identifying high risk plaques.

  9. Intravascular detection of microvessel infiltration in atherosclerotic plaques: An intraluminal extension of acoustic angiography

    NASA Astrophysics Data System (ADS)

    Martin, K. Heath

    Cardiovascular disease is the leading cause of death worldwide, surpassing both stroke and cancer related mortality with 17.5 million deaths in 2014 alone. Atherosclerosis is the build-up of fatty deposits within arteries and is responsible for the majority of cardiovascular related deaths. Over the past decade, research in atherosclerosis has identified that a key limitation in the appropriate management of the disease is detecting and identifying dangerous fatty plaque build-ups before they dislodge and cause major cardiovascular events, such as embolisms, stroke, or myocardial infarctions. It has been noted that plaques vulnerable to rupture have several key features that may be used to distinguish them from asymptomatic plaques. One key identifier of a dangerous plaque is the presence of blood flow within the plaque itself since this is an indicator of growth and instability of the plaque. Recently, a superharmonic imaging method known as "acoustic angiography" has been shown to resolve microvasculature with unprecedented quality and could be a possible method of detecting blood vessel infiltration within these plaques. This dissertation describes the material and methods used to move the application of "acoustic angiography" to a reduced form factor typical of intravascular catheters and to demonstrate its ability to detect microvasculature. The implementation of this approach is described in terms of the contrast agents used to generate superharmonic signals, the dual-frequency transducers to image them, and the hardware needed to operate them in order to establish how these design choices can impact the quality of the images produced. Furthermore, this dissertation demonstrates how image processing methods such as adaptive windowing or automated sound speed correction can further enhance image quality of vascular targets. The results of these chapters show how acoustic angiography may be optimized using engineering considerations both in signal acquisition

  10. Towards coronary plaque imaging using simultaneous PET-MR: a simulation study

    NASA Astrophysics Data System (ADS)

    Petibon, Y.; El Fakhri, G.; Nezafat, R.; Johnson, N.; Brady, T.; Ouyang, J.

    2014-03-01

    Coronary atherosclerotic plaque rupture is the main cause of myocardial infarction and the leading killer in the US. Inflammation is a known bio-marker of plaque vulnerability and can be assessed non-invasively using fluorodeoxyglucose-positron emission tomography imaging (FDG-PET). However, cardiac and respiratory motion of the heart makes PET detection of coronary plaque very challenging. Fat surrounding coronary arteries allows the use of MRI to track plaque motion during simultaneous PET-MR examination. In this study, we proposed and assessed the performance of a fat-MR based coronary motion correction technique for improved FDG-PET coronary plaque imaging in simultaneous PET-MR. The proposed methods were evaluated in a realistic four-dimensional PET-MR simulation study obtained by combining patient water-fat separated MRI and XCAT anthropomorphic phantom. Five small lesions were digitally inserted inside the patients coronary vessels to mimic coronary atherosclerotic plaques. The heart of the XCAT phantom was digitally replaced with the patient's heart. Motion-dependent activity distributions, attenuation maps, and fat-MR volumes of the heart, were generated using the XCAT cardiac and respiratory motion fields. A full Monte Carlo simulation using Siemens mMR's geometry was performed for each motion phase. Cardiac/respiratory motion fields were estimated using non-rigid registration of the transformed fat-MR volumes and incorporated directly into the system matrix of PET reconstruction along with motion-dependent attenuation maps. The proposed motion correction method was compared to conventional PET reconstruction techniques such as no motion correction, cardiac gating, and dual cardiac-respiratory gating. Compared to uncorrected reconstructions, fat-MR based motion compensation yielded an average improvement of plaque-to-background contrast of 29.6%, 43.7%, 57.2%, and 70.6% for true plaque-to-blood ratios of 10, 15, 20 and 25:1, respectively. Channelized

  11. Atorvastatin attenuates atherosclerotic plaque destabilization by inhibiting endoplasmic reticulum stress in hyperhomocysteinemic mice.

    PubMed

    Jia, Fang; Wu, Chunfang; Chen, Zhenyue; Lu, Guoping; Sun, Jianhui

    2016-04-01

    Endoplasmic reticulum (ER) stress has been suggested to play a role in the progression of plaque vulnerability and the occurrence of acute complications of coronary atherosclerosis. Atorvastatin is known to exert pleiotropic effects on the cardiovascular system. The present study aimed to examine the stabilizing effects of atorvastatin on vulnerable plaques within hyperhomocysteinemic apolipoprotein E‑deficient (ApoE‑/‑) mice, and to investigate the potential mechanisms underlying ER stress in ApoE‑/‑ mice and macrophages. In the present study, ApoE‑/‑ mice were administrated methionine or atorvastatin, and were sacrificed after 2 months. Necrotic core size, collagen content and inflammatory cytokine infiltration were subsequently measured in the aortic lesions, in order to investigate plaque stability. Treatment with atorvastatin decreased the number and size of necrotic cores, increased collagen content, and downregulated tumor necrosis factor (TNF)‑α and matrix metalloproteinase (MMP)‑9 mRNA expression, as compared with the methionine group. Immunohistochemical analysis indicated that atorvastatin administration prevented ER stress activation in aortic lesions of hyperhomocysteinemic mice. Furthermore, macrophages were challenged with homocysteine (Hcy) in the presence or absence of atorvastatin and thapsigargin (an ER stress inducer). Atorvastatin suppressed Hcy‑induced ER stress, and downregulated TNF‑α and MMP‑9 mRNA expression in the macrophages. Conversely, thapsigargin attenuated the inhibitory effects of atorvastatin against Hcy‑induced TNF‑α and MMP‑9 expression. These results indicated that hyperhomocysteinemia may promote atherosclerotic plaque development and instability. In addition, atorvastatin was able to improve atherosclerotic plaque stability in hyperhomocysteinemic mice by inhibiting ER stress.

  12. In vitro atherosclerotic plaque and calcium quantitation by intravascular ultrasound and electron-beam computed tomography.

    PubMed

    Gutfinger, D E; Leung, C Y; Hiro, T; Maheswaran, B; Nakamura, S; Detrano, R; Kang, X; Tang, W; Tobis, J M

    1996-05-01

    The purpose of this investigation was to compare the accuracy of intravascular ultrasound (IVUS) and electron-beam computed tomography (EBCT) in quantitating human atherosclerotic plaque and calcium. In experiment 1, 12 human atherosclerotic arterial segments were obtained at autopsy and imaged by using IVUS and EBCT. The plaque from each arterial segment was dissected and a volume measurement of the dissected plaque was obtained by water displacement. The plaque from each arterial segment was ashed at 700 degrees F, and the weight of the remaining ashes was used as an estimate of the calcium mass. In experiment II, 11 calcified arterial segments were obtained at autopsy and imaged by using IVUS at one site along the artery. A corresponding histologic cross section stained with Masson's trichrome was prepared. In experiment I, the mean plaque volume measured by water displacement was 165.3 +/- 118.4 microliters. The mean plaque volume calculated by IVUS was 166.1 +/- 114.4 microliters and correlated closely with that by water displacement (r = 0.98, p < 0.0001). The mean calcium mass measured by ashing was 19.4 +/- 15.8 mg. The mean calculated calcium mass by EBCT was 19.9 mg and correlated closely with that by ashing (r=0.98, p<0.001). The mean calculated calcium volume by IVUS was 18.6 +/- 11.2 microliters and correlated linearly with the calcium mass by ashing (r = 0.87, p < 0.0003). In experiment II, the mean cross-sectional area of the calcified matrix was 1.71 +/- 0.66 mm2 by histologic examination compared with 1.44 +/- 0.66 mm2 by IVUS. There was a good correlation between the calcified cross-sectional area by histologic examination and IVUS (r = 0.76, p < 0.007); however, IVUS may underestimate the amount of calcium present depending on the intralesional calcium morphologic characteristics. In conclusion, IVUS accurately quantitates atherosclerotic plaque volume as well as the cross-sectional area and volume of intralesional calcium, especially if the

  13. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Saturn V Space Vehicle's induction into the National Register of Historic Places by the United States Department of the Interior.

  14. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, located on the grounds of Marshall Space Flight Center in Huntsville, Alabama,commemorates the designation of the Saturn V Rocket as a National Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers in 1980.

  15. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Redstone Test Stand as an Alabama Historic Civil Engineering Landmark. The site was desinated as such in 1979.

  16. Evaluation of Carotid Plaque Using Ultrasound Imaging

    PubMed Central

    2016-01-01

    Traditional risk factors for predicting of cardiovascular disease are not always effective predictors for development of cardiovascular events. This review summarizes several newly developed noninvasive imaging techniques for evaluating carotid plaques and their role in cardiovascular disease risk. PMID:27358696

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

    PubMed Central

    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

  18. Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares.

    PubMed

    Östling, Gerd; Persson, Margaretha; Hedblad, Bo; Gonçalves, Isabel

    2013-11-01

    Grey scale median (GSM) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut-off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with Adobe Photoshop(®) and with Artery Measurement System (AMS) on duplex ultrasound images of 100 consecutive medium- to large-sized carotid plaques of the Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for Adobe Photoshop(®) and AMS, respectively. Mean difference was 20·45 (95% CI: 19·17-21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi-square test revealed a kappa value of 0·68 when studying quartiles of GSM. The intra-observer variability was 1·9% for AMS and 2·5% for Adobe Photoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries.

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

    NASA Astrophysics Data System (ADS)

    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

  20. Static analysis assisted vulnerability-oriented evolutionary fuzzing

    NASA Astrophysics Data System (ADS)

    Yang, Gang; Feng, Chao; Tang, Chaojing

    2017-03-01

    The blindness of fuzzing test is the main reason for its inefficiency in practical vulnerability discovery. In this paper, we proposed a static analysis assisted and vulnerability-oriented fuzzing testing technology. Through the static analysis, the suspect vulnerable code areas can be located roughly. And combined with dynamics update based on the fuzzing feedback, the vulnerable code areas can be further accurately located. By applying the distances to the located vulnerable code areas as one of metrics of the evolutionary fuzzing test, the vulnerability-oriented test cases are generated. The results in the experiment showed that the method proposed in this paper could effectually improve the vulnerability discovering efficiency of fuzzing test.

  1. Spectroscopic photoacoustic imaging of lipid-rich plaques in the human aorta in the 740 to 1400 nm wavelength range

    NASA Astrophysics Data System (ADS)

    Allen, Thomas J.; Hall, Andrew; Dhillon, Amar P.; Owen, James S.; Beard, Paul C.

    2012-06-01

    Spectroscopic photoacoustic imaging has the potential to discriminate between normal and lipid-rich atheromatous areas of arterial tissue by exploiting the differences in the absorption spectra of lipids and normal arterial tissue in the 740 to 1400 nm wavelength range. Identification of regions of high lipid concentration would be useful to identify plaques that are likely to rupture (vulnerable plaques). To demonstrate the feasibility of visualizing lipid-rich plaques, samples of human aortas were imaged in forward mode, at wavelengths of 970 and 1210 nm. It was shown that the structure of the arterial wall and the boundaries of lipid-rich plaques obtained from the photoacoustic images were in good agreement with histology. The presence of lipids was also confirmed by comparing the photoacoustic spectra (740 to 1400 nm) obtained in a region within the plaque to the spectral signature of lipids. Furthermore, a lipid-rich plaque was successfully imaged while illuminating the sample through 2.8 mm of blood demonstrating the possibility of implementing the photoacoustic technique in vivo.

  2. Joint learning of ultrasonic backscattering statistical physics and signal confidence primal for characterizing atherosclerotic plaques using intravascular ultrasound.

    PubMed

    Sheet, Debdoot; Karamalis, Athanasios; Eslami, Abouzar; Noël, Peter; Chatterjee, Jyotirmoy; Ray, Ajoy K; Laine, Andrew F; Carlier, Stephane G; Navab, Nassir; Katouzian, Amin

    2014-01-01

    Intravascular Ultrasound (IVUS) is a predominant imaging modality in interventional cardiology. It provides real-time cross-sectional images of arteries and assists clinicians to infer about atherosclerotic plaques composition. These plaques are heterogeneous in nature and constitute fibrous tissue, lipid deposits and calcifications. Each of these tissues backscatter ultrasonic pulses and are associated with a characteristic intensity in B-mode IVUS image. However, clinicians are challenged when colocated heterogeneous tissue backscatter mixed signals appearing as non-unique intensity patterns in B-mode IVUS image. Tissue characterization algorithms have been developed to assist clinicians to identify such heterogeneous tissues and assess plaque vulnerability. In this paper, we propose a novel technique coined as Stochastic Driven Histology (SDH) that is able to provide information about co-located heterogeneous tissues. It employs learning of tissue specific ultrasonic backscattering statistical physics and signal confidence primal from labeled data for predicting heterogeneous tissue composition in plaques. We employ a random forest for the purpose of learning such a primal using sparsely labeled and noisy samples. In clinical deployment, the posterior prediction of different lesions constituting the plaque is estimated. Folded cross-validation experiments have been performed with 53 plaques indicating high concurrence with traditional tissue histology. On the wider horizon, this framework enables learning of tissue-energy interaction statistical physics and can be leveraged for promising clinical applications requiring tissue characterization beyond the application demonstrated in this paper.

  3. Activation of activator protein 2 alpha by aspirin alleviates atherosclerotic plaque growth and instability in vivo

    PubMed Central

    Yang, Jing-Jing; Li, Peng; Wang, Fu; Liang, Wen-Jing; Ma, Hui; Chen, Yuan; Ma, Zhi-Min; Li, Quan-Zhong; Peng, Qi-Sheng; Zhang, Yun; Wang, Shuang-Xi

    2016-01-01

    Aims Aspirin has been used for the secondary prevention and treatment of cardiovascular disease for several decades. We investigated the roles of transcriptional factor activator protein 2α (AP-2α) in the beneficial effects of aspirin in the growth and vulnerability of atherosclerotic plaque. Methods and Results In mice deficient of apolipoprotein E (Apoe-/-), aspirin (20, 50 mg/kg/day) suppressed the progression of atherosclerosis in aortic roots and increased the plaque stability in carotid atherosclerotic plaques induced by collar-placement. In vivo lentivirus-mediated RNA interference of AP-2α reversed the inhibitory effects of aspirin on atherosclerosis in Apoe-/- mice. Mechanically, aspirin increased AP-2α phosphorylation and its activity, upregulated IkBα mRNA and protein levels, and reduced oxidative stress in cultured vascular smooth muscle cells. Furthermore, deficiency of AP-2α completely abolished aspirin-induced upregulation of IkBα levels and inhibition of oxidative stress in Apoe-/- mice. Clinically, conventional doses of aspirin increased AP-2α phosphorylation and IkBα protein expression in humans subjects. Conclusion Aspirin activates AP-2α to upregulate IkBα gene expression, resulting in attenuations of plaque development and instability in atherosclerosis. PMID:27391154

  4. Plaque characterization in ex vivo MRI evaluated by dense 3D correspondence with histology

    NASA Astrophysics Data System (ADS)

    van Engelen, Arna; de Bruijne, Marleen; Klein, Stefan; Verhagen, Hence; Groen, Harald; Wentzel, Jolanda; van der Lugt, Aad; Niessen, Wiro

    2011-03-01

    Automatic quantification of carotid artery plaque composition is important in the development of methods that distinguish vulnerable from stable plaques. MRI has shown to be capable of imaging different components noninvasively. We present a new plaque classification method which uses 3D registration of histology data with ex vivo MRI data, using non-rigid registration, both for training and evaluation. This is more objective than previously presented methods, as it eliminates selection bias that is introduced when 2D MRI slices are manually matched to histological slices before evaluation. Histological slices of human atherosclerotic plaques were manually segmented into necrotic core, fibrous tissue and calcification. Classification of these three components was voxelwise evaluated. As features the intensity, gradient magnitude and Laplacian in four MRI sequences after different degrees of Gaussian smoothing, and the distances to the lumen and the outer vessel wall, were used. Performance of linear and quadratic discriminant classifiers for different combinations of features was evaluated. Best accuracy (72.5 +/- 7.7%) was reached with the linear classifier when all features were used. Although this was only a minor improvement to the accuracy of a classifier that only included the intensities and distance features (71.6 +/- 7.9%), the difference was statistically significant (paired t-test, p<0.05). Good sensitivity and specificity for calcification was reached (83% and 95% respectively), however, differentiation between fibrous (sensitivity 85%, specificity 60%) and necrotic tissue (sensitivity 49%, specificity 89%) was more difficult.

  5. Science to Practice: Does FDG Differentiate Morphologically Unstable from Stable Atherosclerotic Plaque?

    PubMed

    Dilsizian, Vasken; Jadvar, Hossein

    2017-04-01

    It has been reported that fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) may detect the inflammatory state and macrophage burden of atherosclerotic plaques and potentially identify vulnerable plaques. However, published reports have been inconsistent in this area. Tavakoli et al ( 1 ) hypothesized that differential regulation of macrophage glucose metabolism by macrophage colony-stimulating factor (M-CSF; inflammation resolving) and granulocyte-M-CSF (GM-CSF; proinflammatory) may contribute to the inconsistency of FDG vessel wall inflammation. After the induction of inflammatory and metabolic profiles, both M-CSF and GM-CSF generated comparable levels of glucose uptake in cultured macrophages and murine atherosclerotic plaques. These findings suggest that although FDG uptake is an indicator of vascular macrophage burden (total number of macrophages), it may not necessarily differentiate morphologically unstable (inflammatory) from stable (noninflammatory) atherosclerotic plaque. Moreover, although atherosclerosis is characterized by macrophage-predominated inflammation, there is a wide range of other vascular diseases in which macrophages and inflammation play an important role in the absence of atherosclerosis. FDG uptake will be indistinguishable in atherosclerosis from large-artery inflammatory vascular disease, such as Takayasu arteritis, chemotherapy- or radiation-induced vascular inflammation, or foreign-body reaction, such as synthetic arterial graft. Because of the nonspecific nature of FDG uptake by any cell (upregulated under hypoxic conditions or other microenvironmental factors), this work calls for a more cautious approach to interpreting vascular FDG uptake as indicative of inflammatory atherosclerosis in the clinical setting.

  6. Chemical agents for the control of plaque and plaque microflora: an overview.

    PubMed

    Gaffar, A; Afflitto, J; Nabi, N

    1997-10-01

    This presentation provides an overview of the technologies available for the chemical control of plaque. It is generally accepted that the formation of dental plaque at the interfaces of tooth/gingiva is one of the major causes of gingival inflammation and dental caries. Several therapeutic approaches have been used to control dental plaque and supragingival infections. These include fluoride preparations such as stannous fluoride, oxygenating agents, anti-attachment agents, and cationic and non-cationic antibacterial agents. Among the fluoride preparations, stable stannous fluoride pastes and gels have been shown to reduce supragingival plaque, gingivitis, hypersensitivity and caries. The effect of the oxygenating agents on the supragingival plaque has been equivocal, but recent data indicate that a stable agent which provides sustained active oxygen release is effective in controlling plaque. A polymer, PVPA, which reduced attachment of bacteria to teeth was shown to significantly reduce plaque formation in humans. A new generation of antibacterials includes non-ionics such as triclosan, which in combination with a special polymer delivery system, has been shown to reduce plaque, gingivitis, supragingival calculus and dental caries in long-term studies conducted around the world. Unlike the first generation of agents, the triclosan/copolymer/sodium fluoride system is effective in long-term clinicals and does not cause staining of teeth, increase in calculus, or disturbance in the oral microbial ecology.

  7. Amyloid Plaques in PSAPP Mice Bind Less Metal than Plaques in Human Alzheimer's Disease

    SciTech Connect

    Leskovjan, A.; Lanzirotti, A; Miller, L

    2009-01-01

    Amyloid beta (A{Beta}) is the primary component of Alzheimer's disease (AD) plaques, a key pathological feature of the disease. Metal ions of zinc (Zn), copper (Cu), iron (Fe), and calcium (Ca) are elevated in human amyloid plaques and are thought to be involved in neurodegeneration. Transgenic mouse models of AD also exhibit amyloid plaques, but fail to exhibit the high degree of neurodegeneration observed in humans. In this study, we imaged the Zn, Cu, Fe, and Ca ion distribution in the PSAPP transgenic mouse model representing end-stage AD (N = 6) using synchrotron X-ray fluorescence (XRF) microprobe. In order to account for differences in density in the plaques, the relative protein content was imaged with synchrotron Fourier transform infrared microspectroscopy (FTIRM) on the same samples. FTIRM results revealed a 61% increase in protein content in the plaques compared to the surrounding tissue. After normalizing to protein density, we found that the PSAPP plaques contained only a 29% increase in Zn and there was actually less Cu, Fe, and Ca in the plaque compared to the surrounding tissue. Since metal binding to A{beta} is thought to induce redox chemistry that is toxic to neurons, the reduced metal binding in PSAPP mice is consistent with the lack of neurodegeneration in these animals. These findings were in stark contrast to the high metal ion content observed in human AD plaques, further implicating the role of metal ions in human AD pathology.

  8. DECT evaluation of noncalcified coronary artery plaque

    SciTech Connect

    Ravanfar Haghighi, Rezvan; Chatterjee, S.; Tabin, Milo; Singh, Rishi P.; Sharma, Munish; Krishna, Karthik; Sharma, Sanjiv; Jagia, Priya; Ray, Ruma; Arava, Sudhir; Yadav, Rakesh; Vani, V. C.; Lakshmi, R.; Kumar, Pratik; Mandal, Susama R.

    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

  9. Localized pleural plaques and lung cancer

    SciTech Connect

    Partanen, T.; Nurminen, M.; Zitting, A.; Koskinen, H.; Wiikeri, M.; Ahlman, K. )

    1992-01-01

    In a mass chest radiography survey conducted in 1971 for 7,986 residents of three Finnish communities, 604 subjects (7.6%) with pleural plaques but not other asbestos-related radiographic signs were identified. The same number of referents, each individually matched to each plaque carrier on sex, birth year, and community, was selected from among persons in the same source population with no pleural plaques. The two groups were followed for investigation of incidence of lung cancer during 1972-1989. Twenty-eight of those with plaques and 25 referents contracted lung cancer (crude conditional RR = 1.1; CL95 = 0.7, 1.9). The application of the proportional hazards model, with adjustment for sex, age, and residence, resulted in a hazard ratio of 1.1 (CL = 0.6, 1.8). The risk ratio estimate may be biased; hence, the result is inconclusive in regard to the predictive assessment of lung cancer risk among carriers of pleural plaques.

  10. Functional expression of dental plaque microbiota

    PubMed Central

    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. PMID:25177549

  11. Fatigue crack propagation analysis of plaque rupture.

    PubMed

    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.

  12. Endovascular shear strain elastography for the detection and characterization of the severity of atherosclerotic plaques: in vitro validation and in vivo evaluation.

    PubMed

    Majdouline, Younes; Ohayon, Jacques; Keshavarz-Motamed, Zahra; Roy Cardinal, Marie-Hélène; Garcia, Damien; Allard, Louise; Lerouge, Sophie; Arsenault, Frédéric; Soulez, Gilles; Cloutier, Guy

    2014-05-01

    This work explores the potential of shear strain elastograms to identify vulnerable atherosclerotic plaques. The Lagrangian speckle model estimator (LSME) elasticity imaging method was further developed to estimate shear strain elasticity (SSE). Three polyvinyl alcohol cryogel vessel phantoms were imaged with an intravascular ultrasound (IVUS) scanner. The estimated SSE maps were validated against finite-element results. Atherosclerosis was induced in carotid arteries of eight Sinclair mini-pigs using a combination of surgical techniques, diabetes and a high-fat diet. IVUS images were acquired in vivo in 14 plaques before euthanasia and histology. All plaques were characterized by high magnitudes in SSE maps that correlated with American Heart Association atherosclerosis stage classifications (r = 0.97, p < 0.001): the worse the plaque condition the higher was the absolute value of SSE, i.e. |SSE| (e.g., mean |SSE| was 3.70 ± 0.40% in Type V plaques, whereas it was reduced to 0.11 ± 0.01% in normal walls). This study indicates the feasibility of using SSE to highlight atherosclerotic plaque vulnerability characteristics.

  13. Quantitative assessment of MS plaques and brain atrophy in multiple sclerosis using semiautomatic segmentation method

    NASA Astrophysics Data System (ADS)

    Heinonen, Tomi; Dastidar, Prasun; Ryymin, Pertti; Lahtinen, Antti J.; Eskola, Hannu; Malmivuo, Jaakko

    1997-05-01

    Quantitative magnetic resonance (MR) imaging of the brain is useful in multiple sclerosis (MS) in order to obtain reliable indices of disease progression. The goal of this project was to estimate the total volume of gliotic and non gliotic plaques in chronic progressive multiple sclerosis with the help of a semiautomatic segmentation method developed at the Ragnar Granit Institute. Youth developed program running on a PC based computer provides de displays of the segmented data, in addition to the volumetric analyses. The volumetric accuracy of the program was demonstrated by segmenting MR images of fluid filed syringes. An anatomical atlas is to be incorporated in the segmentation system to estimate the distribution of MS plaques in various neural pathways of the brain. A total package including MS plaque volume estimation, estimation of brain atrophy and ventricular enlargement, distribution of MS plaques in different neural segments of the brain has ben planned for the near future. Our study confirmed that total lesion volumes in chronic MS disease show a poor correlation to EDSS scores but show a positive correlation to neuropsychological scores. Therefore accurate total volume measurements of MS plaques using the developed semiautomatic segmentation technique helped us to evaluate the degree of neuropsychological impairment.

  14. Preoperative 3D FSE T1-Weighted MR Plaque Imaging for Severely Stenotic Cervical ICA: Accuracy of Predicting Emboli during Carotid Endarterectomy.

    PubMed

    Ogasawara, Yasushi; Sato, Yuiko; Narumi, Shinsuke; Sasaki, Makoto; Fujiwara, Shunrou; Kobayashi, Masakazu; Yoshida, Kenji; Terayama, Yasuo; Ogasawara, Kuniaki

    2016-10-27

    The aim of the present study was to determine whether preoperative three-dimensional (3D) fast spin-echo (FSE) T1-weighted magnetic resonance (MR) plaque imaging for severely stenotic cervical carotid arteries could accurately predict the development of artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). Seventy-five patients underwent preoperative MR plaque imaging and CEA under transcranial Doppler ultrasonography of the ipsilateral middle cerebral artery. On reformatted axial MR image slices showing the maximum plaque occupation rate (POR) and maximum plaque intensity for each patient, the contrast ratio (CR) was calculated by dividing the internal carotid artery plaque signal intensity by the sternocleidomastoid muscle signal intensity. For all patients, the area under the receiver operating characteristic curve (AUC)-used to discriminate between the presence and absence of microembolic signals-was significantly greater for the CR on the axial image with maximum plaque intensity (CRmax intensity) (0.941) than for that with the maximum POR (0.885) (p < 0.05). For 32 patients in whom both the maximum POR and the maximum plaque density were identified, the AUCs for the CR were 1.000. Preoperative 3D FSE T1-weighted MR plaque imaging accurately predicts the development of artery-to-artery emboli during exposure of the carotid arteries in CEA.

  15. Preoperative 3D FSE T1-Weighted MR Plaque Imaging for Severely Stenotic Cervical ICA: Accuracy of Predicting Emboli during Carotid Endarterectomy

    PubMed Central

    Ogasawara, Yasushi; Sato, Yuiko; Narumi, Shinsuke; Sasaki, Makoto; Fujiwara, Shunrou; Kobayashi, Masakazu; Yoshida, Kenji; Terayama, Yasuo; Ogasawara, Kuniaki

    2016-01-01

    The aim of the present study was to determine whether preoperative three-dimensional (3D) fast spin-echo (FSE) T1-weighted magnetic resonance (MR) plaque imaging for severely stenotic cervical carotid arteries could accurately predict the development of artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). Seventy-five patients underwent preoperative MR plaque imaging and CEA under transcranial Doppler ultrasonography of the ipsilateral middle cerebral artery. On reformatted axial MR image slices showing the maximum plaque occupation rate (POR) and maximum plaque intensity for each patient, the contrast ratio (CR) was calculated by dividing the internal carotid artery plaque signal intensity by the sternocleidomastoid muscle signal intensity. For all patients, the area under the receiver operating characteristic curve (AUC)—used to discriminate between the presence and absence of microembolic signals—was significantly greater for the CR on the axial image with maximum plaque intensity (CRmax intensity) (0.941) than for that with the maximum POR (0.885) (p < 0.05). For 32 patients in whom both the maximum POR and the maximum plaque density were identified, the AUCs for the CR were 1.000. Preoperative 3D FSE T1-weighted MR plaque imaging accurately predicts the development of artery-to-artery emboli during exposure of the carotid arteries in CEA. PMID:27801780

  16. Plaque assay for virulent Legionella pneumophila.

    PubMed Central

    Fernandez, R C; Lee, S H; Haldane, D; Sumarah, R; Rozee, K R

    1989-01-01

    Methods of assessing virulence of Legionella pneumophila, the etiologic agent of Legionnaires disease, include the infection of guinea pigs, fertile chicken eggs, and mammalian and protozoan cell cultures. Guinea pig assays, in particular, are expensive, laborious, or unsuitable for routine screening of Legionella isolates. We have developed a virulence assay that requires the enumeration of viruslike plaques which are the result of virulent L. pneumophila infecting mouse L929 cells. Each plaque is the consequence of the initial infection of an L cell with a single bacterium. A nonvirulent mutant derived from the serial passage of virulent L. pneumophila on Mueller-Hinton agar fails to survive within L cells and consequently fails to produce plaques. Images PMID:2674192

  17. Association between Randall's Plaque and Calcifying Nanoparticles

    NASA Technical Reports Server (NTRS)

    Ciftcioglu, Neva; Vejdani, Kaveh; Lee, Olivia; Mathew, Grace; Aho, Katja M.; Kajander, Olavi; McKay, David S.; Jones, Jeff A.; Hayat, Matthew; Stoller, Marshall L.

    2007-01-01

    Randall's plaques, first described by Alexander Randall in the 1930s, are small subepithelial calcifications in the renal papillae (RP) that also extend deeply into the renal medulla. Despite the strong correlation between the presence of these plaques and the formation of renal stones, the precise origin and pathogenesis of Randall s plaque formation remain elusive. The discovery of calcifying nanoparticles (CNP) and their detection in many calcifying processes of human tissues has raised hypotheses about their possible involvement in renal stone formation. We collected RP and blood samples from 17 human patients who had undergone laparoscopic nephrectomy due to neoplasia. Homogenized RP tissues and serum samples were cultured for CNP. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis were performed on fixed RP samples. Immunohistochemical staining (IHS) was applied on the tissue samples using CNP-specific monoclonal antibody (mAb). Randall s plaques were visible on gross inspection in 11 out of 17 collected samples. Cultures of all serum samples and 13 tissue homogenates had CNP growth within 4 weeks. SEM revealed spherical apatite formations in 14 samples, with calcium and phosphate peaks detected by EDS analysis. IHS was positive in 9 out of 17 samples. A strong link was found between the presence of Randall s plaques and the detection of CNP, also referred to as nanobacteria. These results suggest new insights into the etiology of Randall's plaque formation, and will help us understand the pathogenesis of stone formation. Further studies on this topic may lead us to new approaches on early diagnosis and novel medical therapies of kidney stone formation.

  18. Aterofisiol® in carotid plaque evolution

    PubMed Central

    Amato, Bruno; Compagna, Rita; Amato, Maurizio; Gallelli, Luca; de Franciscis, Stefano; Serra, Raffaele

    2015-01-01

    Background In patients with carotid stenosis, the risk of plaque rupture is related to the composition of the atherosclerotic plaque rather than to its magnitude. In this regard, we evaluated the effects of a supplement, Aterofisiol,® containing omega-3 (EPA [eicosapen acid] DHA [docosahexaenoic acid]), vitamin K2, vitamin B6, vitamin B12, oligomeric proanthocyanidins (OPC) and resveratrol on the composition of atherosclerotic plaque and on neurological symptoms in patients with carotid stenosis undergoing carotid endarterectomy. Methods The study was randomized, prospective, and double-blinded. Eligible patients were of both sexes, with carotid stenosis >70% who underwent endarterectomy. Enrolled patients were randomly allocated to receive either one tablet of acetylsalicylic acid 100 mg (Cardioaspirin®) + one tablet of Aterofisiol every 24 hours or one tablet of Cardioaspirin + one tablet of placebo every 24 hours. Each treatment was started 30 days before the surgery and was stopped 5 days before the surgery. The plaques were removed “en bloc” using standard surgical technique. Results During the study period, 214 patients (135 men and 79 women) were enrolled for intent-to-treat and randomized in two groups: Group A: 107 patients (68 men and 39 women) were treated with Cardioaspirin + Aterofisiol. Group B: 107 patients (67 men and 40 women) were treated with Cardioaspirin + placebo. At the end of the study, 202 patients participated fully (103 patients in Group A and 99 patients in Group B), making up the protocol evaluation population (94.4%). The mean lipid content of removed plaques was significantly lower (P<0.05) in Group A. We recorded a significantly lower incidence of neurological symptoms in Group A in comparison with Group B (P<0.05). Conclusion In the study, Aterofisiol showed to be effective in reducing the amounts of cholesterol and lipids in the plaques and in reducing adverse neurological events in the study group with respect to controls

  19. Validation of the Filovirus Plaque Assay for Use in Preclinical Studies

    PubMed Central

    Shurtleff, Amy C.; Bloomfield, Holly A.; Mort, Shannon; Orr, Steven A.; Audet, Brian; Whitaker, Thomas; Richards, Michelle J.; Bavari, Sina

    2016-01-01

    A plaque assay for quantitating filoviruses in virus stocks, prepared viral challenge inocula and samples from research animals has recently been fully characterized and standardized for use across multiple institutions performing Biosafety Level 4 (BSL-4) studies. After standardization studies were completed, Good Laboratory Practices (GLP)-compliant plaque assay method validation studies to demonstrate suitability for reliable and reproducible measurement of the Marburg Virus Angola (MARV) variant and Ebola Virus Kikwit (EBOV) variant commenced at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID). The validation parameters tested included accuracy, precision, linearity, robustness, stability of the virus stocks and system suitability. The MARV and EBOV assays were confirmed to be accurate to ±0.5 log10 PFU/mL. Repeatability precision, intermediate precision and reproducibility precision were sufficient to return viral titers with a coefficient of variation (%CV) of ≤30%, deemed acceptable variation for a cell-based bioassay. Intraclass correlation statistical techniques for the evaluation of the assay’s precision when the same plaques were quantitated by two analysts returned values passing the acceptance criteria, indicating high agreement between analysts. The assay was shown to be accurate and specific when run on Nonhuman Primates (NHP) serum and plasma samples diluted in plaque assay medium, with negligible matrix effects. Virus stocks demonstrated stability for freeze-thaw cycles typical of normal usage during assay retests. The results demonstrated that the EBOV and MARV plaque assays are accurate, precise and robust for filovirus titration in samples associated with the performance of GLP animal model studies. PMID:27110807

  20. Novel methodology for 3D reconstruction of carotid arteries and plaque characterization based upon magnetic resonance imaging carotid angiography data.

    PubMed

    Sakellarios, Antonis I; Stefanou, Kostas; Siogkas, Panagiotis; Tsakanikas, Vasilis D; Bourantas, Christos V; Athanasiou, Lambros; Exarchos, Themis P; Fotiou, Evangelos; Naka, Katerina K; Papafaklis, Michail I; Patterson, Andrew J; Young, Victoria E L; Gillard, Jonathan H; Michalis, Lampros K; Fotiadis, Dimitrios I

    2012-10-01

    In this study, we present a novel methodology that allows reliable segmentation of the magnetic resonance images (MRIs) for accurate fully automated three-dimensional (3D) reconstruction of the carotid arteries and semiautomated characterization of plaque type. Our approach uses active contours to detect the luminal borders in the time-of-flight images and the outer vessel wall borders in the T(1)-weighted images. The methodology incorporates the connecting components theory for the automated identification of the bifurcation region and a knowledge-based algorithm for the accurate characterization of the plaque components. The proposed segmentation method was validated in randomly selected MRI frames analyzed offline by two expert observers. The interobserver variability of the method for the lumen and outer vessel wall was -1.60%±6.70% and 0.56%±6.28%, respectively, while the Williams Index for all metrics was close to unity. The methodology implemented to identify the composition of the plaque was also validated in 591 images acquired from 24 patients. The obtained Cohen's k was 0.68 (0.60-0.76) for lipid plaques, while the time needed to process an MRI sequence for 3D reconstruction was only 30 s. The obtained results indicate that the proposed methodology allows reliable and automated detection of the luminal and vessel wall borders and fast and accurate characterization of plaque type in carotid MRI sequences. These features render the currently presented methodology a useful tool in the clinical and research arena.

  1. Narcissistic grandiosity and narcissistic vulnerability in psychotherapy.

    PubMed

    Pincus, Aaron L; Cain, Nicole M; Wright, Aidan G C

    2014-10-01

    This article briefly summarizes the empirical and clinical literature underlying a contemporary clinical model of pathological narcissism. Unlike the DSM Narcissistic Personality Disorder (NPD), this clinical model identifies and differentiates between two phenotypic themes of dysfunction-narcissistic grandiosity and narcissistic vulnerability-that can be expressed both overtly and covertly in patients' ways of thinking, feeling, behaving, and participating in treatment. Clinical recognition that narcissistic patients can and often do present for psychotherapy in vulnerable states of depression, anxiety, shame, and even suicidality increases the likelihood of accurate diagnosis and effective treatment planning. This article provides case examples derived from psychotherapies with narcissistic patients to demonstrate how narcissistic grandiosity and narcissistic vulnerability concurrently present in patients who seek treatment.

  2. Facility Environmental Vulnerability Assessment

    SciTech Connect

    Van Hoesen, S.D.

    2001-07-09

    From mid-April through the end of June 2001, a Facility Environmental Vulnerability Assessment (FEVA) was performed at Oak Ridge National Laboratory (ORNL). The primary goal of this FEVA was to establish an environmental vulnerability baseline at ORNL that could be used to support the Laboratory planning process and place environmental vulnerabilities in perspective. The information developed during the FEVA was intended to provide the basis for management to initiate immediate, near-term, and long-term actions to respond to the identified vulnerabilities. It was expected that further evaluation of the vulnerabilities identified during the FEVA could be carried out to support a more quantitative characterization of the sources, evaluation of contaminant pathways, and definition of risks. The FEVA was modeled after the Battelle-supported response to the problems identified at the High Flux Beam Reactor at Brookhaven National Laboratory. This FEVA report satisfies Corrective Action 3A1 contained in the Corrective Action Plan in Response to Independent Review of the High Flux Isotope Reactor Tritium Leak at the Oak Ridge National Laboratory, submitted to the Department of Energy (DOE) ORNL Site Office Manager on April 16, 2001. This assessment successfully achieved its primary goal as defined by Laboratory management. The assessment team was able to develop information about sources and pathway analyses although the following factors impacted the team's ability to provide additional quantitative information: the complexity and scope of the facilities, infrastructure, and programs; the significantly degraded physical condition of the facilities and infrastructure; the large number of known environmental vulnerabilities; the scope of legacy contamination issues [not currently addressed in the Environmental Management (EM) Program]; the lack of facility process and environmental pathway analysis performed by the accountable line management or facility owner; and poor

  3. In vivo MRI-based simulation of fatigue process: a possible trigger for human carotid atherosclerotic plaque rupture

    PubMed Central

    2013-01-01

    Background Atherosclerotic plaque is subjected to a repetitive deformation due to arterial pulsatility during each cardiac cycle and damage may be accumulated over a time period causing fibrous cap (FC) fatigue, which may ultimately lead to rupture. In this study, we investigate the fatigue process in human carotid plaques using in vivo carotid magnetic resonance (MR) imaging. Method Twenty seven patients with atherosclerotic carotid artery disease were included in this study. Multi-sequence, high-resolution MR imaging was performed to depict the plaque structure. Twenty patients were found with ruptured FC or ulceration and 7 without. Modified Paris law was used to govern crack propagation and the propagation direction was perpendicular to the maximum principal stress at the element node located at the vulnerable site. Results The predicted crack initiations from 20 patients with FC defect all matched with the locations of the in vivo observed FC defect. Crack length increased rapidly with numerical steps. The natural logarithm of fatigue life decreased linearly with the local FC thickness (R2 = 0.67). Plaques (n=7) without FC defect had a longer fatigue life compared with those with FC defect (p = 0.03). Conclusion Fatigue process seems to explain the development of cracks in FC, which ultimately lead to plaque rupture. PMID:23617791

  4. Association between Randall's Plaque and Calcifying Nanoparticles

    NASA Technical Reports Server (NTRS)

    Citfcioglu, Neva; Vejdani, Kaveh; Lee, Olivia; Mathew, Grace; Aho, Katja M.; Kajander, Olavi; McKay, David S.; Jones, Jeffrey A.; Feiveson, Alan H.; Stoller, Marshall L.

    2007-01-01

    Randall initially described calcified subepithelial papillary plaques, which he hypothesized as nidi for kidney stone formation. The discovery of calcifying nanoparticles (CNP) in many calcifying processes of human tissues has raised another hypothesis about their possible involvement in urinary stone formation. This research is the first attempt to investigate the potential association of these two hypotheses. We collected renal papilla and blood samples from 17 human patients who had undergone laparoscopic nephrectomy due to neoplasia. Immunohistochemical staining (IHS) was applied on the tissue samples using monoclonal antibody 8D10 (mAb) against CNP. Homogenized papillary tissues and serum samples were cultured for CNP. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis were performed on fixed papillary samples. Randall's plaques were visible on gross inspection in 11 out of 17 collected samples. IHS was positive for CNP antigen in 8 of these 11 visually positive samples, but in only 1 of the remaining 6 samples. SEM revealed spherical apatite formations in 14 samples, all of which had calcium and phosphate peaks detected by EDS analysis. From this study, there was some evidence of a link between the presence of Randall's plaques and the detection of CNP, also referred to as nanobacteria. Although causality was not demonstrated, these results suggest that further studies with negative control samples should be made to explore the etiology of Randall's plaque formation, thus leading to a better understanding of the pathogenesis of stone formation.

  5. Adalimumab: A Review in Chronic Plaque Psoriasis.

    PubMed

    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.

  6. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the designation of the Propulsion and Structural Test Facility as a National Historic Landmark by the National Park Service of the United States Interior. The site was designated as a landmark in 1985.

  7. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Redstone Test Stand as a National Historic Landmark. The site was designated as such in 1985 by the National Park Service of the United States Department of the Interior.

  8. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Saturn V Dynamic Test Stand as a National Historic Landmark. The site was designated as such in 1985 by the National Park Service of the United States Department of the Interior.

  9. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Saturn V Launch Vehicle as a National Historic Landmark. The site was designated as such in 1984 by the National Park Service of the United States Department of the Interior.

  10. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama commemorates the Neutral Buoyancy Space Simulator as a National Historic Landmark. The site was designated as such in 1986 by the National Park Service of the United States Department of the Interior.

  11. BATON ROUGE NATIONAL CEMETERY PLAQUE MOUNTED ON BASE OF FLAGPOLE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BATON ROUGE NATIONAL CEMETERY PLAQUE MOUNTED ON BASE OF FLAGPOLE, WITH NATIONAL REGISTER OF HISTORIC PLACES PLAQUE AT RIGHT. VIEW TO NORTH. - Baton Rouge National Cemetery, 220 North 19th Street, Baton Rouge, East Baton Rouge Parish, LA

  12. 18. Photocopy of drawing of bronze dedication plaque, circa 1903 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Photocopy of drawing of bronze dedication plaque, circa 1903 (original drawing in possession of City Engineer's Office Grand Rapids, Michigan) DEDICATION PLAQUE. - Bridge Street Bridge, Spanning Grand River, Michigan & Bridge Streets, Grand Rapids, MI

  13. Fleshing out vulnerability.

    PubMed

    Tavaglione, Nicolas; Martin, Angela K; Mezger, Nathalie; Durieux-Paillard, Sophie; François, Anne; Jackson, Yves; Hurst, Samia A

    2015-02-01

    In the literature on medical ethics, it is generally admitted that vulnerable persons or groups deserve special attention, care or protection. One can define vulnerable persons as those having a greater likelihood of being wronged - that is, of being denied adequate satisfaction of certain legitimate claims. The conjunction of these two points entails what we call the Special Protection Thesis. It asserts that persons with a greater likelihood of being denied adequate satisfaction of their legitimate claims deserve special attention, care or protection. Such a thesis remains vague, however, as long as we do not know what legitimate claims are. This article aims at dispelling this vagueness by exploring what claims we have in relation to health care - thus fleshing out a claim-based conception of vulnerability. We argue that the Special Protection Thesis must be enriched as follows: If individual or group X has a greater likelihood of being denied adequate satisfaction of some of their legitimate claims to (i) physical integrity, (ii) autonomy, (iii) freedom, (iv) social provision, (v) impartial quality of government, (vi) social bases of self-respect or (vii) communal belonging, then X deserves special attention, care or protection. With this improved understanding of vulnerability, vulnerability talk in healthcare ethics can escape vagueness and serve as an adequate basis for practice.

  14. Artery buckling affects the mechanical stress in atherosclerotic plaques

    PubMed Central

    2015-01-01

    Background Tortuous arteries are often seen in patients with hypertension and atherosclerosis. While the mechanical stress in atherosclerotic plaque under lumen pressure has been studied extensively, the mechanical stability of atherosclerotic arteries and subsequent effect on the plaque stress remain unknown. To this end, we investigated the buckling and post-buckling behavior of model stenotic coronary arteries with symmetric and asymmetric plaque. Methods Buckling analysis for a model coronary artery with symmetric and asymmetric plaque was conducted using finite element analysis based on the dimensions and nonlinear anisotropic materials properties reported in the literature. Results Artery with asymmetric plaque had lower critical buckling pressure compared to the artery with symmetric plaque and control artery. Buckling increased the peak stress in the plaque and led to the development of a high stress concentration in artery with asymmetric plaque. Stiffer calcified tissue and severe stenosis increased the critical buckling pressure of the artery with asymmetric plaque. Conclusions Arteries with atherosclerotic plaques are prone to mechanical buckling which leads to a high stress concentration in the plaques that can possibly make the plaques prone to rupture. PMID:25603490

  15. Cosmonaut Leonov and Astronaut Stafford display ASTP commemorative plaque

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Cosmonaut Aleksey A. Leonov (on left) and Astronaut Thomas P. Stafford display the Apollo Soyuz Test Project (ASTP) commemorative plaque. The two commanders of their respective crews are in the Apollo Command Module trainer in bldg 35 at JSC. The two plaques divided into four quarters each will be flown on the ASTP mission. The plaque is written in both English and Russian.

  16. TB in Vulnerable Populations

    PubMed Central

    Ugarte-Gil, César; Caro, Godofredo; Aylas, Rula; Castro, César; Lema, Claudia

    2016-01-01

    Abstract This article analyzes the factors associated with vulnerability of the Ashaninka, the most populous indigenous Peruvian Amazonian people, to tuberculosis (TB). By applying a human rights-based analytical framework that assesses public policy against human rights standards and principles, and by offering a step-by-step framework for a full assessment of compliance, it provides evidence of the relationship between the incidence of TB among the Ashaninka and Peru’s poor level of compliance with its human rights obligations. The article argues that one of the main reasons for the historical vulnerability of the Ashaninka to diseases such as TB is a lack of political will on the part of the national government to increase public health spending, ensure that resources reach the most vulnerable population, and adopt and invest in a culturally appropriate health system. PMID:27780999

  17. Energy vulnerability relationships

    SciTech Connect

    Shaw, B.R.; Boesen, J.L.

    1998-02-01

    The US consumption of crude oil resources has been a steadily growing indicator of the vitality and strength of the US economy. At the same time import diversity has also been a rapidly developing dimension of the import picture. In the early 1970`s, embargoes of crude oil from Organization of Producing and Exporting Countries (OPEC) created economic and political havoc due to a significant lack of diversity and a unique set of economic, political and domestic regulatory circumstances. The continued rise of imports has again led to concerns over the security of our crude oil resource but threats to this system must be considered in light of the diversity and current setting of imported oil. This report develops several important issues concerning vulnerability to the disruption of oil imports: (1) The Middle East is not the major supplier of oil to the United States, (2) The US is not vulnerable to having its entire import stream disrupted, (3) Even in stable countries, there exist vulnerabilities to disruption of the export stream of oil, (4) Vulnerability reduction requires a focus on international solutions, and (5) DOE program and policy development must reflect the requirements of the diverse supply. Does this increasing proportion of imported oil create a {open_quotes}dependence{close_quotes}? Does this increasing proportion of imported oil present a vulnerability to {open_quotes}price shocks{close_quotes} and the tremendous dislocations experienced during the 1970`s? Finally, what is the vulnerability of supply disruptions from the current sources of imported oil? If oil is considered to be a finite, rapidly depleting resource, then the answers to these questions must be {open_quotes}yes.{close_quotes} However, if the supply of oil is expanding, and not limited, then dependence is relative to regional supply sources.

  18. Plutonium Vulnerability Management Plan

    SciTech Connect

    1995-03-01

    This Plutonium Vulnerability Management Plan describes the Department of Energy`s response to the vulnerabilities identified in the Plutonium Working Group Report which are a result of the cessation of nuclear weapons production. The responses contained in this document are only part of an overall, coordinated approach designed to enable the Department to accelerate conversion of all nuclear materials, including plutonium, to forms suitable for safe, interim storage. The overall actions being taken are discussed in detail in the Department`s Implementation Plan in response to the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 94-1. This is included as Attachment B.

  19. Objective quantification of plaque using digital image analysis.

    PubMed

    Sagel, P A; Lapujade, P G; Miller, J M; Sunberg, R J

    2000-01-01

    Dental plaque is the precursor to many oral diseases (e.g. gingivitis, periodontitis, caries) and thus its removal and control are an important aspect of oral hygiene. Many of the oral care products available today remove or inhibit the growth of dental plaque. Historically, the antiplaque efficacy of products was measured in blinded clinical trials where the amount of plaque on teeth is assessed via subjective visual grading with predefined scales such as the Turesky index. The ability of the examiner to consistently apply the index over time and the sensitivity of the scales often leads to large, expensive clinical trials. The present invention is an automatic measurement of plaque coverage on the facial surfaces of teeth using a digital image analysis technique. Dental plaque disclosed with fluorescein is digitally imaged under long-wave ultraviolet light. Ultraviolet illumination of fluorescein-disclosed plaque produces an image where the pixels of the image can be categorically classified based on color into one of five classes: teeth; plaque; gingiva; plaque on gingiva, or lip retractors. The amount of plaque on teeth can be determined by summation of the number of plaque pixels. The percent coverage is calculated from the number of plaque pixels and teeth pixels in the image. The digital image analysis of plaque allows facial plaque levels to be precisely measured (RSD = 3.77%). In application, the digital image analysis of plaque is capable of measuring highly significant plaque growth inhibition of a stannous fluoride dentifrice with as few as 10 subjects in a cross-over design.

  20. Non-invasive assessment of atherosclerotic plaques effects on the segment-to-segment human carotid visco-elasticity and filtering.

    PubMed

    Bia, D; Pessana, F; Forcada, P; Zócalo, Y; Kotliar, C; Armentano, R L

    2010-01-01

    Although a variety of factors have been proposed as key factors of the atherosclerotic plaque vulnerability, the mechanisms that contribute to this problem are not yet fully characterized. In previous works we demonstrated that changes in arterial wall viscosity and elasticity and/or in the filtering function (FF) could be in the basis of arterial wall alterations. If these properties are altered in arterial wall with atherosclerotic plaques remain to be analyzed. Our aims were to analyze, the arterial wall visco-elasticity and FF of human carotid arteries with atherosclerotic plaques. To this end, instantaneous arterial diameter waveforms were obtained non-invasively (B-Mode Echography), in five sites (S1-S5) on the carotid artery. After that, diameter waveform obtained in S1 (first segment of the common carotid artery) was calibrated using pressure values, and used to quantify the pressure-diameter relationship for each segment. From pressure-diameter relationships, viscosity, elasticity and FF were quantified. Central portions of atherosclerotic plaques showed a reduced FF. At least in theoretical terms, the FF reduction could be related with the plaque vulnerability.

  1. Delinquent Recidivists: Vulnerable Children.

    ERIC Educational Resources Information Center

    Moore, Roslyn; And Others

    1984-01-01

    This study examines the relationship between vulnerability factors and recidivism of juvenile offenders. Four factors are identified which distinguish recedivists from nonrecidivists in a sample of 96 first offenders matched by age and sex. Results are discussed from an epidemiological and early intervention perspective. (Author/BS)

  2. Biological Vulnerability to Alcoholism.

    ERIC Educational Resources Information Center

    Schuckit, Marc A.

    1987-01-01

    Reviews the role of biological factors in the risk for alcoholism. Notes the importance of the definition of primary alcoholism and highlights data indicating that this disorder is genetically influenced. In studies of men at high risk for the future development of alcoholism, vulnerability shows up in reactions to ethanol brain wave amplitude and…

  3. Plaque formation of dietary isomaltulose in humans.

    PubMed

    Ooshima, T; Izumitani, A; Takei, T; Fujiwara, T; Sobue, S

    1990-01-01

    The plaque formation of isomaltulose, a sucrose isomer, was examined in 15 human volunteers with both diet and oral hygiene under supervision. The subjects were requested to refrain from all oral hygiene procedures for 3 days and were provided between-meal snacks containing 157 g of 4 test sugars (100% isomaltulose, 70% isomaltulose + 30% sucrose, 50% isomaltulose + 50% sucrose, and 100% sucrose). The study was repeated 4 times over 4 weeks. The isomaltulose diet resulted in the lowest plaque index, while sucrose induced a significantly greater deposition. In the absence of sucrose-containing snacks, mutans streptococci in saliva decreased below the baseline level. These results suggest that isomaltulose may be a suitable substitute for sucrose in between meal snacks.

  4. Enucleation versus plaque irradiation for choroidal melanoma

    SciTech Connect

    Straatsma, B.R.; Fine, S.L.; Earle, J.D.; Hawkins, B.S.; Diener-West, M.; McLaughlin, J.A.

    1988-07-01

    The Collaborative Ocular Melanoma Study (COMS) is an international, multicenter-controlled study. The organization includes an Executive Committee, Steering Committee, 6 Central Units, 32 Clinical Centers, and a Data and Safety Monitoring Committee. Scientifically, the COMS consists of (1) a randomized trial of patients with medium choroidal melanoma treated with enucleation versus iodine-125 plaque irradiation, (2) a randomized trial of patients with large choroidal melanoma treated with enucleation versus preenucleation external beam irradiation and enucleation, and (3) a prospective observational study of patients with small choroidal melanoma to determine whether a randomized trial of treatment is appropriate. In design and conduct of the COMS, special consideration is given to biostatistics and sample size considerations, iodine-125 plaque irradiation of choroidal melanoma, and coordinated ocular melanoma research. Recruitment is in progress. However, the pool of eligible patients is limited and the COMS needs the continued support and cooperation of ophthalmologists throughout the United States and Canada.

  5. Plaque accumulations caused by interdental stripping.

    PubMed

    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.

  6. Impact of Wall Shear Stress and Pressure Variation on the Stability of Atherosclerotic Plaque

    NASA Astrophysics Data System (ADS)

    Taviani, V.; Li, Z. Y.; Sutcliffe, M.; Gillard, J.

    Rupture of vulnerable atheromatous plaque in the carotid and coronary arteries often leads to stroke and heart attack respectively. The mechanism of blood flow and plaque rupture in stenotic arteries is still not fully understood. A three dimensional rigid wall model was solved under steady and unsteady conditions assuming a time-varying inlet velocity profile to investigate the relative importance of axial forces and pressure drops in arteries with asymmetric stenosis. Flow-structure interactions were investigated for the same geometry and the results were compared with those retrieved with the corresponding one dimensional models. The Navier-Stokes equations were used as the governing equations for the fluid. The tube wall was assumed linearly elastic, homogeneous isotropic. The analysis showed that wall shear stress is small (less than 3.5%) with respect to pressure drop throughout the cycle even for severe stenosis. On the contrary, the three dimensional behavior of velocity, pressure and wall shear stress is in general very different from that predicted by one dimensional models. This suggests that the primary source of mistakes in one dimensional studies comes from neglecting the three dimensional geometry of the plaque. Neglecting axial forces only involves minor errors.

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

    PubMed Central

    RAGGIO, Daniela Prócida; BRAGA, Mariana Minatel; RODRIGUES, Jonas Almeida; FREITAS, Patrícia Moreira; IMPARATO, José Carlos Pettorossi; MENDES, Fausto Medeiros

    2010-01-01

    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. Conclusions The Turesky index and images with FC with disclosing present good reliability and discriminatory power in quantifying dental plaque. PMID:20485931

  8. SU-E-T-635: Process Mapping of Eye Plaque Brachytherapy

    SciTech Connect

    Huynh, J; Kim, Y

    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.

  9. Development of a novel plaque reduction neutralisation test for hantavirus infection.

    PubMed

    Pádua, Michelly de; Souza, William Marciel de; Lauretti, Flávio; Figueiredo, Luiz Tadeu Moraes

    2015-08-01

    In the Americas, hantaviruses cause severe cardiopulmonary syndrome (HCPS) with a high fatality rate. Hantavirus infection is commonly diagnosed using serologic techniques and reverse transcription-polymerase chain reaction. This paper presents a novel plaque reduction neutralisation test (PRNT) for detecting antibodies to Brazilian hantavirus. Using PRNT, plaque detection was enhanced by adding 0.6% of dimethyl sulfoxide into the overlay culture medium of the infected cells. This procedure facilitated clear visualisation of small plaques under the microscope and provided for easy and accurate plaque counting. The sera from 37 HCPS patients from the city of Ribeirão Preto, Brazil was evaluated for the Rio Mamoré virus (RIOMV) using PRNT. Six samples exhibited neutralising antibodies; these antibodies exhibited a low titre. The low level of seropositive samples may be due to fewer cross-reactions between two different hantavirus species; the patients were likely infected by Araraquara virus (a virus that has not been isolated) and RIOMV was used for the test. This assay offers a new approach to evaluating and measuring neutralising antibodies produced during hantavirus infections and it can be adapted to other hantaviruses, including viruses that will be isolated in the future.

  10. Recent advances in visualizing vulnerable plaque: focus on noninvasive molecular imaging.

    PubMed

    Bala, Gezim; Cosyns, Bernard

    2014-09-01

    Traditional imaging methods in atherosclerosis have focused primarily on anatomic information. Imaging approaches that visualize molecular targets rather than anatomic structures may emphasize biologic aspects of atherosclerosis. Molecular imaging of atherosclerotic lesions has become a crucial experimental tool and is now emerging in the clinical arena. In this review, we briefly highlight the rationale and fundamental principles of molecular imaging. We then discuss the promising imaging modalities, along with their potential limitations, and the molecular targets being investigated in experimental research. Finally, we summarize the most important clinical studies recently performed in humans.

  11. Myocardial Bridge and Acute Plaque Rupture

    PubMed Central

    Perl, Leor; Daniels, David; Schwartz, Jonathan; Tanaka, Shige; Yeung, Alan; Tremmel, Jennifer A.; Schnittger, Ingela

    2016-01-01

    A myocardial bridge (MB) is a common anatomic variant, most frequently located in the left anterior descending coronary artery, where a portion of the coronary artery is covered by myocardium. Importantly, MBs are known to result in a proximal atherosclerotic lesion. It has recently been postulated that these lesions predispose patients to acute coronary events, even in cases of otherwise low-risk patients. One such mechanism may involve acute plaque rupture. In this article, we report 2 cases of patients with MBs who presented with acute coronary syndromes despite having low cardiovascular risk. Their presentation was life-risking and both were treated urgently and studied with coronary angiographies and intravascular ultrasound. This latter modality confirmed a rupture of an atherosclerotic plaque proximal to the MB as a likely cause of the acute events. These cases, of unexplained acute coronary syndrome in low-risk patients, raise the question of alternative processes leading to the event and the role MB play as an underlying cause of ruptured plaques. In some cases, an active investigation for this entity may be warranted, due to the prognostic implications of the different therapeutic modalities, should an MB be discovered. PMID:28251167

  12. Cataractogenesis after Cobalt-60 eye plaque radiotherapy

    SciTech Connect

    Kleineidam, M.; Augsburger, J.J. ); Hernandez, C.; Glennon, P.; Brady, L.W. )

    1993-07-15

    This study was designed to estimate the actuarial incidence of typical postirradiation cataracts and to identify prognostic factors related to their development in melanoma-containing eyes treated by Cobalt-60 plaque radiotherapy. A special interest was the impact of calculated radiation dose and dose-rate to the lens. The authors evaluated the actuarial occurrence of post-irradiation cataract in 365 patients with primary posterior uveal melanoma treated by Cobalt-60 plaque radiotherapy between 1976 and 1986. Only 22% (S.E. = 4.6%) of the patients who received a total dose of 6 to 20 Gy at the center of the lens developed a visually significant cataract attributable to the radiation within 5 years after treatment. Using multivariate Cox proportional hazards modeling, the authors identified thickness of the tumor, location of the tumor's anterior margin relative to the equatorward and the ora serrata, and diameter of the eye plaque used as the best combination of covariables for predicting length of time until development of cataract. Surprisingly, the dose of radiation delivered to the lens, which was strongly correlated to all of these covariables, was not a significant predictive factor in multivariate analysis. The results suggest that success of efforts to decrease the occurrence rate of post-irradiation cataracts by better treatment planning might be limited in patients with posterior uveal melanoma. 21 refs., 2 figs., 5 tabs.

  13. Retroperitoneal liposarcoma associated with small plaque parapsoriasis

    PubMed Central

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

    2007-01-01

    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. PMID:17620118

  14. Microwave plaque thermoradiotherapy for choroidal melanoma.

    PubMed Central

    Finger, P. T.

    1992-01-01

    Microwave thermoradiotherapy was used as a primary treatment for 44 patients with choroidal melanoma. An episcleral dish-shaped microwave antenna was placed beneath the tumour at the time of plaque brachytherapy. While temperatures were measured at the sclera, the tumour's apex was targeted to receive a minimum of 42 degrees C for 45 minutes. In addition, the patients received full or reduced doses of plaque radiotherapy. No patients have been lost to follow-up. Two eyes have been enucleated: one for rubeotic glaucoma, and one for uveitic glaucoma. Though six patients have died, only one death was due to metastatic choroidal melanoma (39 months after treatment). Clinical observations suggest that the addition of microwave heating to plaque radiation therapy of choroidal melanoma has been well tolerated. There has been a 97.7% local control rate (with a mean follow-up of 22.2 months). We have reduced the minimum tumour radiation dose (apex dose) to levels used for thermoradiotherapy of cutaneous melanomas (50 Gy/5000 rad). Within the range of this follow-up period no adverse effects which might preclude the use of this microwave heat delivery system for treatment of choroidal melanoma have been noted. Images PMID:1622949

  15. Cellular immune response in multiple sclerosis plaques.

    PubMed Central

    Boyle, E. A.; McGeer, P. L.

    1990-01-01

    Multiple sclerosis plaques were immunohistochemically stained to exhibit cells expressing immune-system antigens. Human leukocyte antigen (HLA)-DR-positive cells formed dense rings around all plaque regions. The majority were reactive microglia/macrophages. Counterstaining with oil red O revealed heavy myelin debris within these cells. They were distinct from astrocytes, which were identified with an antibody to glial fibrillary acidic protein (GFAP) and which did not contain oil red O myelin debris. Numerous leukocytes and microglia were stained with antibody to leukocyte common antigen (LCA). Lymphocytes in cuffs around vessels, along the margins of capillary walls, and, sparingly, in the tissue matrix of affected areas, were stained with antibodies to CD4 (T-helper/inducer) and CD8 (T-cytotoxic/suppressor). In experimental allergic encephalomyelitis (EAE) induced in Lewis rats, a similar proliferation of Ia-positive (OX6, OX17) cells displaying reactive microglia/macrophage morphology was observed. These Ia-positive cells also were easily distinguished from GFAP-positive astrocytes. The results suggest that macrophages/reactive microglia, and not astrocytes, express class II MHC antigens in multiple sclerosis and EAE plaques. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:1698025

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

    PubMed

    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 < 0.0001). If critical stress at FC(MIN) was only used, then the stress condition of 238 of 352 MR slices would be underestimated, while if the critical stress at 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.

  17. The Myth of “The Vulnerable Plaque”: Transitioning from a Focus on Individual Lesions to Atherosclerotic Disease Burden for Coronary Artery Disease Risk Assessment

    PubMed Central

    Arbab-Zadeh, Armin; Fuster, Valentin

    2014-01-01

    The cardiovascular science community has pursued the quest to identify vulnerable atherosclerotic plaque in patients for decades, hoping to prevent acute coronary events. However, despite major advancements in imaging technology that allow visualization of rupture-prone plaques, clinical studies have not demonstrated improved risk prediction compared to traditional approaches. Considering the complex relationship between plaque rupture and acute coronary event risk suggested by pathology studies and confirmed by clinical investigations, these results are not surprising. This review summarizes the evidence supporting a multifaceted hypothesis of the natural history of atherosclerotic plaque rupture. Managing patients at risk of suffering acute coronary events mandates a greater focus on the atherosclerotic disease burden, rather than on features of individual plaques. PMID:25601032

  18. Carotid atherosclerotic plaque characterisation by measurement of ultrasound sound speed in vitro at high frequency, 20 MHz.

    PubMed

    Brewin, M P; Srodon, P D; Greenwald, S E; Birch, M J

    2014-02-01

    This study aimed to utilise a tissue mimicking material (TMM) in order to embed in vitro carotid plaque tissue so that its acoustic properties could be assessed. Here, an International Electrotechnical Commission (IEC) agar-based TMM was adapted to a clear gel by removal of the particulates. This clear TMM was measured with sound speed at 1540 ms(-1) and an attenuation coefficient of 0.15 dB cm(-1)MHz(-1). Composite sound speed was then measured through the embedded material using a scanning acoustic microscope (SAM). Both broadband reflection and transmission techniques were performed on each plaque specimen in order to ensure the consistency of the measurement of sound speed, both at 21 °C and 37 °C. The plaque was measured at two temperatures to investigate any effect on the lipid content of the plaque. The contour maps from its associated attenuation plots were used to match the speed data to the photographic mask of the plaque outline. This physical matching was then used to derive the sound speed from the percentage composition seen in the histological data by solution of simultaneous equations. Individual speed values for five plaque components were derived; TMM, elastin, fibrous/collagen, calcification and lipid. The results for derived sound speed in the TMM were consistently close to the expected value of soft tissue, 1540 ms(-1). The fibrous tissue showed a mean value of 1584 ms(-1) at 37 °C. The derived sound speeds for elastic and lipid exhibited large inter-quartile ranges. The calcification had higher sound speed than the other plaque components at 1760-2000 ms(-1). The limitations here lay in the difficulties in the matching process caused by the inhomogeneity of the plaque material and shrinkage during the histological process. Future work may concentrate on more homogeneous material in order to derive sound speed data for separate components. Nevertheless, this study increases the known data ranges of the individual components within a plaque

  19. Overexpression of Prolyl-4-Hydroxylase-α1 Stabilizes but Increases Shear Stress-Induced Atherosclerotic Plaque in Apolipoprotein E-Deficient Mice

    PubMed Central

    Liu, Xin-xin; Li, Meng-meng; Zhang, Yu; Chen, Liang; Wang, Lin; Di, Ming-xue

    2016-01-01

    The rupture and erosion of atherosclerotic plaque can induce coronary thrombosis. Prolyl-4-hydroxylase (P4H) plays a central role in the synthesis of all known types of collagens, which are the most abundant constituent of the extracellular matrix in atherosclerotic plaque. The pathogenesis of atherosclerosis is thought to be in part caused by shear stress. In this study, we aimed to investigate a relationship between P4Hα1 and shear stress-induced atherosclerotic plaque. Carotid arteries of ApoE−/− mice were exposed to low and oscillatory shear stress conditions by the placement of a shear stress cast for 2 weeks; we divided 60 male ApoE−/− mice into three groups for treatments with saline (mock) (n = 20), empty lentivirus (lenti-EGFP) (n = 20), and lentivirus-P4Hα1 (lenti-P4Hα1) (n = 20). Our results reveal that after 2 weeks of lenti-P4Hα1 treatment both low and oscillatory shear stress-induced plaques increased collagen and the thickness of fibrous cap and decreased macrophage accumulation but no change in lipid accumulation. We also observed that overexpression of P4Ha1 increased plaque size. Our study suggests that P4Hα1 overexpression might be a potential therapeutic target in stabilizing vulnerable plaques. PMID:27818566

  20. Assessment of atherosclerotic plaque collagen content and architecture using polarization-sensitive optical coherence tomography (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Doradla, Pallavi; Villiger, Martin; Tshikudi, Diane M.; Bouma, Brett E.; Nadkarni, Seemantini K.

    2016-02-01

    Acute myocardial infarction, caused by the rupture of vulnerable coronary plaques, is the leading cause of death worldwide. Collagen is the primary extracellular matrix macromolecule that imparts the mechanical stability to a plaque and its reduction causes plaque instability. Intracoronary polarization sensitive optical coherence tomography (PS-OCT) measures the polarization states of the backscattered light from the tissue to evaluate plaque birefringence, a material property that is elevated in proteins such as collagen with an ordered structure. Here we investigate the dependence of the PS-OCT parameters on the quantity of the plaque collagen and fiber architecture. In this study, coronary arterial segments from human cadaveric hearts were evaluated with intracoronary PS-OCT and compared with Histopathological assessment of collagen content and architecture from picrosirius-red (PSR) stained sections. PSR sections were visualized with circularly-polarized light microscopy to quantify collagen birefringence, and the additional assessment of color hue indicated fibril thickness. Due to the ordered architecture of thick collagen fibers, a positive correlation between PS-OCT retardation and quantity of thick collagen fibers (r=0.54, p=0.04), and similarly with the total collagen content (r=0.51, p=0.03) was observed. In contrast, there was no perceivable relationship between PS-OCT retardation and the presence of thin collagen fibers (r=0.08, p=0.07), suggesting that thin and disorganized collagen fiber architecture did not significantly contribute to the PS-OCT retardation. Further analysis will be performed to assess the relationship between PS-OCT retardation and collagen architecture based on immunohistochemical analysis of collagen type. These results suggest that intracoronary PS-OCT may open the opportunity to assess collagen architecture in addition total collagen content, potentially enabling an improved understanding of coronary plaque rupture.

  1. Bacteriology of Human Experimental Gingivitis: Effect of Plaque Age

    PubMed Central

    Syed, S. A.; Loesche, W. J.

    1978-01-01

    Twenty-five subjects with previously excellent hygiene and healthy gingiva developed heavy plaque accumulations and bleeding or nonbleeding gingivitis about certain papilla after 21 days of no oral hygiene. Gingival marginal plaque about a single papilla was collected at 0, 1, 2, and 3 weeks of no oral hygiene in each subject. The plaque was dispersed, serially diluted, and plated on MM10 sucrose agar in an oxygen-free atmosphere. From 50 to 100 colonies from a single high-dilution plate were characterized for each sample. Over 8,500 isolates were partially characterized and placed into one of 29 taxonomic species or groups. The flora was predominantly gram-positive at all time periods. Streptococcal species dominated in the 0- and 1-week-old plaques, i.e. 62 and 43% of the colonyforming units (CFU), but dropped to 26 to 32% of the CFU in the 2- and 3-week-old plaques. Actinomyces species dominated in the older plaques, i.e., 40 to 50% of the CFU. Actinomyces israelii was the most prominent species in the older plaques. Veillonella accounted for 15 to 20% of the CFU at all time periods. Although the other gram-negative species increased with time, collectively they averaged less than 5% of the CFU at week 3. The shift from a Streptococcus-dominated plaque to an Actinomyces-dominated plaque was the most striking microbial change observed as the plaque aged. PMID:711336

  2. The microscopic network structure of mussel (Mytilus) adhesive plaques

    PubMed Central

    DeMartini, Daniel G.; Waite, J. Herbert

    2015-01-01

    Marine mussels of the genus Mytilus live in the hostile intertidal zone, attached to rocks, bio-fouled surfaces and each other via collagen-rich threads ending in adhesive pads, the plaques. Plaques adhere in salty, alkaline seawater, withstanding waves and tidal currents. Each plaque requires a force of several newtons to detach. Although the molecular composition of the plaques has been well studied, a complete understanding of supra-molecular plaque architecture and its role in maintaining adhesive strength remains elusive. Here, electron microscopy and neutron scattering studies of plaques harvested from Mytilus californianus and Mytilus galloprovincialis reveal a complex network structure reminiscent of structural foams. Two characteristic length scales are observed characterizing a dense meshwork (approx. 100 nm) with large interpenetrating pores (approx. 1 µm). The network withstands chemical denaturation, indicating significant cross-linking. Plaques formed at lower temperatures have finer network struts, from which we hypothesize a kinetically controlled formation mechanism. When mussels are induced to create plaques, the resulting structure lacks a well-defined network architecture, showcasing the importance of processing over self-assembly. Together, these new data provide essential insight into plaque structure and formation and set the foundation to understand the role of plaque structure in stress distribution and toughening in natural and biomimetic materials. PMID:26631333

  3. The microscopic network structure of mussel (Mytilus) adhesive plaques.

    PubMed

    Filippidi, Emmanouela; DeMartini, Daniel G; Malo de Molina, Paula; Danner, Eric W; Kim, Juntae; Helgeson, Matthew E; Waite, J Herbert; Valentine, Megan T

    2015-12-06

    Marine mussels of the genus Mytilus live in the hostile intertidal zone, attached to rocks, bio-fouled surfaces and each other via collagen-rich threads ending in adhesive pads, the plaques. Plaques adhere in salty, alkaline seawater, withstanding waves and tidal currents. Each plaque requires a force of several newtons to detach. Although the molecular composition of the plaques has been well studied, a complete understanding of supra-molecular plaque architecture and its role in maintaining adhesive strength remains elusive. Here, electron microscopy and neutron scattering studies of plaques harvested from Mytilus californianus and Mytilus galloprovincialis reveal a complex network structure reminiscent of structural foams. Two characteristic length scales are observed characterizing a dense meshwork (approx. 100 nm) with large interpenetrating pores (approx. 1 µm). The network withstands chemical denaturation, indicating significant cross-linking. Plaques formed at lower temperatures have finer network struts, from which we hypothesize a kinetically controlled formation mechanism. When mussels are induced to create plaques, the resulting structure lacks a well-defined network architecture, showcasing the importance of processing over self-assembly. Together, these new data provide essential insight into plaque structure and formation and set the foundation to understand the role of plaque structure in stress distribution and toughening in natural and biomimetic materials.

  4. CYBER/PHYSICAL SECURITY VULNERABILITY ASSESSMENT INTEGRATION

    SciTech Connect

    MacDonald, Douglas G.; Key, Brad; Clements, Samuel L.; Hutton, William J.; Craig, Philip A.; Patrick, Scott W.; Crawford, Cary E.

    2011-07-17

    This internally funded Laboratory-Directed R&D project by the Pacific Northwest National Laboratory, in conjunction with QinetiQ North America, is intended to identify and properly assess areas of overlap (and interaction) in the vulnerability assessment process between cyber security and physical protection. Existing vulnerability analysis (VA) processes and software tools exist, and these are heavily utilized in the determination of predicted vulnerability within the physical and cyber security domains. These determinations are normally performed independently of one another, and only interact on a superficial level. Both physical and cyber security subject matter experts have come to realize that though the various interactive elements exist, they are not currently quantified in most periodic security assessments. This endeavor aims to evaluate both physical and cyber VA techniques and provide a strategic approach to integrate the interdependent relationships of each into a single VA capability. This effort will also transform the existing suite of software currently utilized in the physical protection world to more accurately quantify the risk associated with a blended attack scenario. Performance databases will be created to support the characterization of the cyber security elements, and roll them into prototype software tools. This new methodology and software capability will enable analysts to better identify and assess the overall risk during a vulnerability analysis.

  5. Micro-analysis of plaque fluid from single-site fasted plaque

    SciTech Connect

    Vogel, G.L.; Carey, C.M.; Chow, L.C.; Tatevossian, A. )

    1990-06-01

    Despite the site-specific nature of caries, nearly all data on the concentration of ions relevant to the level of saturation of plaque fluid with respect to calcium phosphate minerals or enamel are from studies that used pooled samples. A procedure is described for the collection and analysis of inorganic ions relevant to these saturation levels in plaque fluid samples collected from a single surface on a single tooth. Various methods for examining data obtained by this procedure are described, and a mathematical procedure employing potential plots is recommended.

  6. Vulnerability analysis for design of bridge health monitoring system

    NASA Astrophysics Data System (ADS)

    Sun, L. M.; Yu, G.

    2010-03-01

    The recent engineering implementation of health monitoring system for long span bridges show difficulties for precisely assessing structural physical condition as well as for accurately alarming on structural damages, although hundreds of sensors were installed on a structure and a great amount of data were collected from the monitoring system. The allocation of sensors and the alarming algorithm are still two of the most important tasks to be considered when designing the structural health monitoring system. Vulnerability, in its original meaning, is the system susceptibility to local damage. For a structural system, the vulnerability can thus be regarded as structural performance susceptibility to local damage of structure. The purpose of this study is to propose concepts and methods of structural vulnerability for determining monitoring components which are more vulnerable than others and the corresponding warning threshold once the damages occur. The structural vulnerability performances to various damage scenarios depend upon structural geometrical topology, loading pattern on the structure and the degradation of component performance. A two-parameters structural vulnerability evaluation method is proposed in this paper. The parameters are the damage consequence and the relative magnitude of the damage scenarios to the structural system, respectively. Structural vulnerability to various damage scenarios can be regarded as the tradeoff between the two parameters. Based on the results of structural vulnerability analysis, the limited structural information from health monitoring can be utilized efficiently. The approach of the design of bridge health monitoring system is illustrated for a cable-stayed bridge.

  7. Plaque Size Is Decreased but M1 Macrophage Polarization and Rupture Related Metalloproteinase Expression Are Maintained after Deleting T-Bet in ApoE Null Mice

    PubMed Central

    Tsaousi, Aikaterini; Hayes, Elaine M.; Di Gregoli, Karina; Bond, Andrew R.; Bevan, Laura

    2016-01-01

    Background Thelper1 (Th1) lymphocytes have been previously implicated in atherosclerotic plaque growth but their role in plaque vulnerability to rupture is less clear. We investigated whether T-bet knockout that prevents Th1 lymphocyte differentiation modulates classical (M1) macrophage activation or production of matrix degrading metalloproteinases (MMPs) and their tissue inhibitors, TIMPs. Methods & Results We studied the effect of T-bet deletion in apolipoproteinE (ApoE) knockout mice fed a high fat diet (HFD) or normal chow diet (ND). Transcript levels of M1/M2 macrophage polarization markers, selected MMPs and TIMPs were measured by RT-qPCR in macrophages isolated from subcutaneous granulomas or in whole aortae. Immunohistochemistry of aortic sinus (AS) and brachiocephalic artery (BCA) plaques was conducted to quantify protein expression of the same factors. Deletion of T-bet decreased mRNA for the M1 marker NOS-2 in granuloma macrophages but levels of M2 markers (CD206, arginase-1 and Ym-1), MMPs-2, -9, -12, -13, -14 and -19 or TIMPs-1 to -3 were unchanged. No mRNA differences were observed in aortic extracts from mice fed a HFD for 12 weeks. Moreover, AS and BCA plaques were similarly sized between genotypes, and had similar areas stained for NOS-2, COX-2, MMP-12 and MMP-14 proteins. T-bet deletion increased MMP-13, MMP-14 and arginase-1 in AS plaques. After 35 weeks of ND, T-bet deletion reduced the size of AS and BCA plaques but there were no differences in the percentage areas stained for M1 or M2 markers, MMPs-12, -13, -14, or TIMP-3. Conclusions Absence of Th1 lymphocytes is associated with reduced plaque size in ApoE knockout mice fed a normal but not high fat diet. In either case, M1 macrophage polarization and expression of several MMPs related to plaque instability are either maintained or increased. PMID:26886778

  8. Icaritin Inhibits Collagen Degradation-Related Factors and Facilitates Collagen Accumulation in Atherosclerotic Lesions: A Potential Action for Plaque Stabilization

    PubMed Central

    Zhang, Zong-Kang; Li, Jie; Yan, De-Xin; Leung, Wing-Nang; Zhang, Bao-Ting

    2016-01-01

    Most acute coronary syndromes result from rupture of vulnerable atherosclerotic plaques. The collagen content of plaques may critically affect plaque stability. This study tested whether Icaritin (ICT), an intestinal metabolite of Epimedium-derived flavonoids, could alter the collagen synthesis/degradation balance in atherosclerotic lesions. Rabbits were fed with an atherogenic diet for four months. Oral administration of ICT (10 mg·kg−1·day−1) was started after two months of an atherogenic diet and lasted for two months. The collagen degradation-related parameters, including macrophages accumulation, content and activity of interstitial collagenase-1 (MMP-1), and the collagen synthesis-related parameters, including amount and distribution of smooth muscle cells (SMC) and collagen mRNA/protein levels, were evaluated in the aorta. ICT reduced plasma lipid levels, inhibited macrophage accumulation, lowered MMP-1 mRNA and protein expression, and suppressed proteolytic activity of pro-MMP-1 and MMP-1 in the aorta. ICT changed the distribution of the SMCs towards the fibrous cap of lesions without increasing the amount of SMCs. Higher collagen protein content in lesions and aorta homogenates was observed with ICT treatment compared with the atherogenic diet only, without altered collagen mRNA level. These results suggest that ICT could inhibit the collagen degradation-related factors and facilitate collagen accumulation in atherosclerotic lesions, indicating a new potential of ICT in atherosclerotic plaques. PMID:26828485

  9. Icaritin Inhibits Collagen Degradation-Related Factors and Facilitates Collagen Accumulation in Atherosclerotic Lesions: A Potential Action for Plaque Stabilization.

    PubMed

    Zhang, Zong-Kang; Li, Jie; Yan, De-Xin; Leung, Wing-Nang; Zhang, Bao-Ting

    2016-01-28

    Most acute coronary syndromes result from rupture of vulnerable atherosclerotic plaques. The collagen content of plaques may critically affect plaque stability. This study tested whether Icaritin (ICT), an intestinal metabolite of Epimedium-derived flavonoids, could alter the collagen synthesis/degradation balance in atherosclerotic lesions. Rabbits were fed with an atherogenic diet for four months. Oral administration of ICT (10 mg·kg(-1)·day(-1)) was started after two months of an atherogenic diet and lasted for two months. The collagen degradation-related parameters, including macrophages accumulation, content and activity of interstitial collagenase-1 (MMP-1), and the collagen synthesis-related parameters, including amount and distribution of smooth muscle cells (SMC) and collagen mRNA/protein levels, were evaluated in the aorta. ICT reduced plasma lipid levels, inhibited macrophage accumulation, lowered MMP-1 mRNA and protein expression, and suppressed proteolytic activity of pro-MMP-1 and MMP-1 in the aorta. ICT changed the distribution of the SMCs towards the fibrous cap of lesions without increasing the amount of SMCs. Higher collagen protein content in lesions and aorta homogenates was observed with ICT treatment compared with the atherogenic diet only, without altered collagen mRNA level. These results suggest that ICT could inhibit the collagen degradation-related factors and facilitate collagen accumulation in atherosclerotic lesions, indicating a new potential of ICT in atherosclerotic plaques.

  10. Experimental measurements and Monte Carlo calculations for (103)Pd dosimetry of the 12 mm COMS eye plaque.

    PubMed

    Saidi, Pooneh; Sadeghi, Mahdi; Tenreiro, Claudio

    2013-05-01

    Monte Carlo simulations and TLD dosimetry have been performed to determine the dose distributions along the central axis of the 12 mm COMS eye plaques loaded with IRA1-(103)Pd seeds. Several simulations and measurements have been employed to investigate the effect of Silastic insert and air in front of the eye on dosimetry results along the central axis of the plaque and at some critical ocular structures. Measurements were performed using TLD-GR200A circular chip dosimeters in a PMMA eye phantom. The central axis TLD chips locations were arranged in one central column of eye phantom, in 3 mm intervals. The off-axis TLD chips locations were arranged in three off-axis columns around the central axis column. Version 5 of the MCNP code was also used to evaluate the dose distribution around the plaque. The presence of the Silastic insert results in dose reduction of 14% at 5 mm; also about 7% dose reduction appears at the interface point, due to the air presence and lack of the scattering condition. The overall dosimetric parameters for the COMS eye plaque loaded with new palladium seeds are similar to a commercial widely used seed such as Theragenics200. As the dose calculations under TG-43 assumptions do not consider the effect of the plaque backing and Silastic insert for accurate dosimetry, it's suggested to apply the effect of the eye plaque materials and air on dosimetry results along the central axis of the plaque and at some critical ocular structures.

  11. Characterization of lipid-rich plaques using spectroscopic optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Nam, Hyeong Soo; Song, Joon Woo; Jang, Sun-Joo; Lee, Jae Joong; Oh, Wang-Yuhl; Kim, Jin Won; Yoo, Hongki

    2016-07-01

    Intravascular optical coherence tomography (IV-OCT) is a high-resolution imaging method used to visualize the internal structures of walls of coronary arteries in vivo. However, accurate characterization of atherosclerotic plaques with gray-scale IV-OCT images is often limited by various intrinsic artifacts. In this study, we present an algorithm for characterizing lipid-rich plaques with a spectroscopic OCT technique based on a Gaussian center of mass (GCOM) metric. The GCOM metric, which reflects the absorbance properties of lipids, was validated using a lipid phantom. In addition, the proposed characterization method was successfully demonstrated in vivo using an atherosclerotic rabbit model and was found to have a sensitivity and specificity of 94.3% and 76.7% for lipid classification, respectively.

  12. Intradural Extramedullary Tuberculoma Mimicking En Plaque Meningioma

    PubMed Central

    Shim, Dae Moo; Kim, Tae Kyun; Chae, Soo Uk

    2010-01-01

    A 24-year-old man with tuberculosis meningitis developed acute paraplegia and sensory disturbances 5 weeks after receiving conventional antituberculous therapy. Magnetic resonance imaging revealed an intradural extramedullary long segmental mass mimicking en plaque meningioma at the T2-T6 vertebrae levels. Prompt surgical decompression was performed. A histology examination of the mass revealed a tuberculoma. After surgery, the patient showed improved motor power and a normal bladder function. Intradural extramedullary tuberculoma of the spinal cord is rare complication of tuberculosis meningitis, which can occur as a response to conventional antituberculous therapy. PMID:21119945

  13. Fibrous Pleural Plaques Detected at Autopsy

    PubMed Central

    TÜRKMEN, Nursel; EREN, Bülent; GÜNDOĞMUŞ, Ümit Naci

    2014-01-01

    The reported case was a 84-year-old male, dead after a traffic accident. The death was considered to be suspicious by prosecutor and an autopsy was mandated. In macroscopic autopsy investigation left tibia, fibula and multiple rib fractures, widespread seborrheic keratoses, and hyperpigmented skin lesions were detected. In the left chest cavity blood content and white colored lesions spread on the left parietal pleura and chest surface of the thoracic diaphragm were observed. The histological examination of the pleural lesions revealed fibrotic hyalinized structures with calcified foci. Investigation of pleural plaques in forensic autopsy is important for scientific classification of this interesting entity. PMID:25705312

  14. Plaques Formed by Mutagenized Viral Populations Have Elevated Coinfection Frequencies

    PubMed Central

    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

  15. Dosimetric Benefit of a New Ophthalmic Radiation Plaque

    SciTech Connect

    Marwaha, Gaurav; Wilkinson, Allan; Bena, James; Macklis, Roger; Singh, Arun D.

    2012-12-01

    Purpose: To determine whether the computed dosimetry of a new ophthalmic plaque, EP917, when compared with the standard Collaborative Ocular Melanoma Study (COMS) plaques, could reduce radiation exposure to vision critical structures of the eye. Methods and Materials: One hundred consecutive patients with uveal melanoma treated with COMS radiation plaques between 2007 and 2010 were included in this study. These treatment plans were generated with the use of Bebig Plaque Simulator treatment-planning software, both for COMS plaques and for EP917 plaques using I-125. Dose distributions were calculated for a prescription of 85 Gy to the tumor apex. Doses to the optic disc, opposite retina, lens, and macula were obtained, and differences between the 2 groups were analyzed by standard parametric methods. Results: When compared with the COMS plaques, the EP917 plaques used fewer radiation seeds by an average difference of 1.94 (P<.001; 95% confidence interval [CI], -2.8 to -1.06) and required less total strength of radiation sources by an average of 17.74 U (air kerma units) (P<.001; 95% CI, -20.16 to -15.32). The total radiation doses delivered to the optic disc, opposite retina, and macula were significantly less by 4.57 Gy, 0.50 Gy, and 11.18 Gy, respectively, with the EP917 plaques vs the COMS plaques. Conclusion: EP917 plaques deliver less overall radiation exposure to critical vision structures than COMS treatment plaques while still delivering the same total therapeutic dose to the tumor.

  16. Subsurface ablation of atherosclerotic plaque using ultrafast laser pulses

    PubMed Central

    Lanvin, Thomas; Conkey, Donald B.; Frobert, Aurelien; Valentin, Jeremy; Goy, Jean-Jacques; Cook, Stéphane; Giraud, Marie-Noelle; Psaltis, Demetri

    2015-01-01

    We perform subsurface ablation of atherosclerotic plaque using ultrafast pulses. Excised mouse aortas containing atherosclerotic plaque were ablated with ultrafast near-infrared (NIR) laser pulses. Optical coherence tomography (OCT) was used to observe the ablation result, while the physical damage was inspected in histological sections. We characterize the effects of incident pulse energy on surface damage, ablation hole size, and filament propagation. We find that it is possible to ablate plaque just below the surface without causing surface damage, which motivates further investigation of ultrafast ablation for subsurface atherosclerotic plaque removal. PMID:26203381

  17. DETAIL OF PLAQUE DESCRIBING LION SCULPTURES BY ROLAND HINTON PERRY, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF PLAQUE DESCRIBING LION SCULPTURES BY ROLAND HINTON PERRY, NORTHWEST ABUTMENT - Connecticut Avenue Bridge, Spans Rock Creek & Potomac Parkway at Connecticut Avenue, Washington, District of Columbia, DC

  18. Subsurface ablation of atherosclerotic plaque using ultrafast laser pulses.

    PubMed

    Lanvin, Thomas; Conkey, Donald B; Frobert, Aurelien; Valentin, Jeremy; Goy, Jean-Jacques; Cook, Stéphane; Giraud, Marie-Noelle; Psaltis, Demetri

    2015-07-01

    We perform subsurface ablation of atherosclerotic plaque using ultrafast pulses. Excised mouse aortas containing atherosclerotic plaque were ablated with ultrafast near-infrared (NIR) laser pulses. Optical coherence tomography (OCT) was used to observe the ablation result, while the physical damage was inspected in histological sections. We characterize the effects of incident pulse energy on surface damage, ablation hole size, and filament propagation. We find that it is possible to ablate plaque just below the surface without causing surface damage, which motivates further investigation of ultrafast ablation for subsurface atherosclerotic plaque removal.

  19. 25. DETAIL VIEW OF COMMEMORATIVE NAMEPLATE PLAQUE, NORTH END SPAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. DETAIL VIEW OF COMMEMORATIVE NAMEPLATE PLAQUE, NORTH END SPAN - East Bloomsburg Bridge, Spanning Susquehanna River at Pennsylvania Route 487 (Legislative Route 283), Bloomsburg, Columbia County, PA

  20. 14. DETAIL VIEW OF COMMEMORATIVE PLAQUE AND FINIAL, NORTH END ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. DETAIL VIEW OF COMMEMORATIVE PLAQUE AND FINIAL, NORTH END SPAN - East Bloomsburg Bridge, Spanning Susquehanna River at Pennsylvania Route 487 (Legislative Route 283), Bloomsburg, Columbia County, PA

  1. Expression of NPP1 is regulated during atheromatous plaque calcification

    PubMed Central

    Nitschke, Yvonne; Hartmann, Simone; Torsello, Giovanni; Horstmann, Rüdiger; Seifarth, Harald; Weissen-Plenz, Gabriele; Rutsch, Frank

    2011-01-01

    Abstract Mutations of the ENPP1 gene encoding ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) are associated with medial calcification in infancy. While the inhibitory role of matrix proteins such as osteopontin (OPN) with respect to atherosclerotic plaque calcification has been established, the role of NPP1 in plaque calcification is not known. We assessed the degree of plaque calcification (computed tomography), NPP1 and OPN localization (immunohistochemistry) and expression (RT-PCR) in a cohort of 45 patients undergoing carotid endatherectomy for significant stenosis of the internal carotid artery and in normal arteries (N= 50). We correlated NPP1 and OPN expression levels to the degree of plaque calcification, to pro-atherogenic factors and statin therapy. NPP1 was demonstrated in the base and in the shoulder of atherosclerotic plaques. Compared to normal arteries and non-calcified plaques, in calcified plaques NPP1 mRNA was decreased (P < 0.0001). OPN mRNA levels were up-regulated in carotid atheroma. NPP1 and OPN expression levels positively correlated with the degree of plaque calcification (R= 0.54, P= 0.00019 and R= 0.46, P= 0.017, respectively) and with risk factors of atherosclerosis. Expression of the calcification inhibitor NPP1 is down-regulated in calcified atherosclerotic plaques. Our correlation data point to a counter-active mechanism, which in the end turns out to be insufficient to prevent further progression of calcification. PMID:20015201

  2. Aggregation and disaggregation of senile plaques in Alzheimer disease

    PubMed Central

    Cruz, L.; Urbanc, B.; Buldyrev, S. V.; Christie, R.; Gómez-Isla, T.; Havlin, S.; McNamara, M.; Stanley, H. E.; Hyman, B. T.

    1997-01-01

    We quantitatively analyzed, using laser scanning confocal microscopy, the three-dimensional structure of individual senile plaques in Alzheimer disease. We carried out the quantitative analysis using statistical methods to gain insights about the processes that govern Aβ peptide deposition. Our results show that plaques are complex porous structures with characteristic pore sizes. We interpret plaque morphology in the context of a new dynamical model based on competing aggregation and disaggregation processes in kinetic steady-state equilibrium with an additional diffusion process allowing Aβ deposits to diffuse over the surface of plaques. PMID:9207140

  3. Aging and Neuronal Vulnerability

    PubMed Central

    Mattson, Mark P.; Magnus, Tim

    2011-01-01

    Everyone ages, but only some will acquire a neurodegenerative disorder in the process. Disease might occur when cells fail to respond adaptively to age-related increases in oxidative, metabolic and ionic stress resulting in excessive accumulation of damaged proteins, DNA and membranes. Determinants of neuronal vulnerability might include cell size and location, metabolism of disease-specific proteins, and repertoire of signal transduction pathways and stress resistance mechanisms. Emerging evidence on protein interaction networks that monitor and respond to the normal aging process suggests that successful neural aging is possible for most, but also cautions that cures for neurodegenerative disorders are unlikely in the near future. PMID:16552414

  4. Assessment of plaque assay methods for alphaviruses.

    PubMed

    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.

  5. Concept of Remission in Chronic Plaque Psoriasis.

    PubMed

    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.

  6. The molecular concept of atheromatous plaques.

    PubMed

    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.

  7. Effect of Chlorhexidine with Fluoride Mouthrinse on Plaque Accumulation, Plaque pH - A Double Blind Parallel Randomized Clinical Trial

    PubMed Central

    Saha, Sabyasachi; Singh, Sanjay

    2016-01-01

    Introduction Mouthwashes are important means used in chemical control of dental plaque. There is strong evidence suggestive of better effectiveness, when fluoride is added to chlorhexidine mouthwash. Aim To assess the anti-plaque efficacy of Chlorhexidine combined with Fluoride mouthwash and to measure its impact on plaque accumulation and on plaque pH. Materials and Methods Initially 100 subjects were screened. A double blind, parallel randomized clinical trial was conducted on 30 subjects after applying inclusion and exclusion criteria. Other independent variables were matched before randomly allocating them in three groups: Group A-Chlorhexidine as positive control, Group B-Chlorhexidine + Fluoride as test group and Group C- Distilled water as negative control. Oral prophylaxis of participants was done before onset of the study. Plaque pH was assessed before and immediately after rinsing at 0, 5 and 10 minutes interval and after 7 days with digital pH electrode (pHepR pH meter, Hanna Instruments R10285) and accumulation of plaque was recorded by Turesky et al., modification of Quigley Hein Plaque Index (1970). ANOVA test was used for statistical analysis. Results Although there was a statistically significant reduction in mean plaque scores from baseline to seven days in both Groups A and B, Group B showed better anti-plaque efficacy . Almost equal drop in plaque pH was seen for both the groups at 5 and 10 minutes. Conclusion Better anti-plaque efficacy was observed in Group B (Chlorhexidine and Fluoride combination) with minimum variation of plaque pH. PMID:27630956

  8. Beyond 'vulnerable groups': contexts and dynamics of vulnerability.

    PubMed

    Zarowsky, Christina; Haddad, Slim; Nguyen, Vinh-Kim

    2013-03-01

    This paper reviews approaches to vulnerability in public health, introducing a series of 10 papers addressing vulnerability in health in Africa. We understand vulnerability as simultaneously a condition and a process. Social inequalities are manifest in and exacerbate three key dimensions of vulnerability: the initial level of wellbeing, the degree of exposure to risk, and the capacity to manage risk effectively. We stress the dynamic interactions linking material and social deprivation, poverty, powerlessness and ill health: risks or shocks and their health impacts are intimately interconnected and reinforce each other in a cycle which in the absence of effective interventions, increases vulnerability. An inductive process which does not begin with an a priori definition or measurement of 'vulnerability' and which does not assume the existence of fixed 'vulnerable groups' allowed us both to re-affirm core aspects of existing conceptual frameworks, and to engage in new ways with literature specifically addressing vulnerability and resilience at the population level as well as with literature - for example in ecology, and on the concept of frailty in research on aging - with which researchers on health and poverty in Africa may not be familiar. We invite conceptual and empirical work on vulnerability in complex systems frameworks. These perspectives emphasize contexts and nonlinear causality thus supporting analyses of vulnerability and resilience as both markers and emergent properties of dynamic interactions. We accept a working definition of vulnerability, and recognize that some definable groups of people are more likely than others to suffer harm from exposure to health risks. But we suggest that the real work - at both intellectual and policy/political levels - lies in understanding and responding to the dynamics, meanings and power relations underlying actual instances and processes of vulnerability and harm.

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

    PubMed

    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.

  10. Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

    PubMed Central

    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

  11. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  12. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  13. Monoglyceride lipase deficiency modulates endocannabinoid signaling and improves plaque stability in ApoE-knockout mice

    PubMed Central

    Vujic, Nemanja; Schlager, Stefanie; Eichmann, Thomas O.; Madreiter-Sokolowski, Corina T.; Goeritzer, Madeleine; Rainer, Silvia; Schauer, Silvia; Rosenberger, Angelika; Woelfler, Albert; Doddapattar, Prakash; Zimmermann, Robert; Hoefler, Gerald; Lass, Achim; Graier, Wolfgang F.; Radovic, Branislav; Kratky, Dagmar

    2016-01-01

    Background and aims Monoglyceride lipase (MGL) catalyzes the final step of lipolysis by degrading monoglyceride (MG) to glycerol and fatty acid. MGL also hydrolyzes and thereby deactivates 2-arachidonoyl glycerol (2-AG), the most abundant endocannabinoid in the mammalian system. 2-AG acts as full agonist on cannabinoid receptor type 1 (CB1R) and CB2R, which are mainly expressed in brain and immune cells, respectively. Thus, we speculated that in the absence of MGL, increased 2-AG concentrations mediate CB2R signaling in immune cells to modulate inflammatory responses, thereby affecting the development of atherosclerosis. Methods and results We generated apolipoprotein E (ApoE)/MGL double-knockout (DKO) mice and challenged them with Western-type diet for 9 weeks. Despite systemically increased 2-AG concentrations in DKO mice, CB2R-mediated signaling remains fully functional, arguing against CB2R desensitization. We found increased plaque formation in both en face aortae (1.3-fold, p = 0.028) and aortic valve sections (1.5-fold, p = 0.0010) in DKO mice. Interestingly, DKO mice also presented reduced lipid (12%, p = 0.031) and macrophage content (18%, p = 0.061), elevated intraplaque smooth muscle staining (1.4-fold, p = 0.016) and thicker fibrous caps (1.8-fold, p = 0.0032), together with a higher ratio of collagen to necrotic core area (2.5-fold, p = 0.0003) and expanded collagen content (1.6-fold, p = 0.0007), which suggest formation of less vulnerable atherosclerotic plaques. Treatment with a CB2R inverse agonist prevents these effects in DKO mice, demonstrating that the observed plaque phenotype in DKO mice originates from CB2R activation. Conclusion Loss of MGL modulates endocannabinoid signaling in CB2R-expressing cells, which concomitantly affects the pathogenesis of atherosclerosis. We conclude that despite larger lesion size loss of MGL improves atherosclerotic plaque stability. Thus, pharmacological MGL inhibition may be a novel intervention to reduce

  14. Risk assessment by dynamic representation of vulnerability, exploitation, and impact

    NASA Astrophysics Data System (ADS)

    Cam, Hasan

    2015-05-01

    Assessing and quantifying cyber risk accurately in real-time is essential to providing security and mission assurance in any system and network. This paper presents a modeling and dynamic analysis approach to assessing cyber risk of a network in real-time by representing dynamically its vulnerabilities, exploitations, and impact using integrated Bayesian network and Markov models. Given the set of vulnerabilities detected by a vulnerability scanner in a network, this paper addresses how its risk can be assessed by estimating in real-time the exploit likelihood and impact of vulnerability exploitation on the network, based on real-time observations and measurements over the network. The dynamic representation of the network in terms of its vulnerabilities, sensor measurements, and observations is constructed dynamically using the integrated Bayesian network and Markov models. The transition rates of outgoing and incoming links of states in hidden Markov models are used in determining exploit likelihood and impact of attacks, whereas emission rates help quantify the attack states of vulnerabilities. Simulation results show the quantification and evolving risk scores over time for individual and aggregated vulnerabilities of a network.

  15. Multiscale vulnerability of complex networks.

    PubMed

    Boccaletti, Stefano; Buldú, Javier; Criado, Regino; Flores, Julio; Latora, Vito; Pello, Javier; Romance, Miguel

    2007-12-01

    We present a novel approach to quantify the vulnerability of a complex network, i.e., the capacity of a graph to maintain its functional performance under random damages or malicious attacks. The proposed measure represents a multiscale evaluation of vulnerability, and makes use of combined powers of the links' betweenness. We show that the proposed approach is able to properly describe some cases for which earlier measures of vulnerability fail. The relevant applications of our method for technological network design are outlined.

  16. Lack of autologous tissue transmission of eosinophilic plaques in cats.

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Ultrafast laser ablation for targeted atherosclerotic plaque removal

    NASA Astrophysics Data System (ADS)

    Lanvin, Thomas; Conkey, Donald B.; Descloux, Laurent; Frobert, Aurelien; Valentin, Jeremy; Goy, Jean-Jacques; Cook, Stéphane; Giraud, Marie-Noelle; Psaltis, Demetri

    2015-07-01

    Coronary artery disease, the main cause of heart disease, develops as immune cells and lipids accumulate into plaques within the coronary arterial wall. As a plaque grows, the tissue layer (fibrous cap) separating it from the blood flow becomes thinner and increasingly susceptible to rupturing and causing a potentially lethal thrombosis. The stabilization and/or treatment of atherosclerotic plaque is required to prevent rupturing and remains an unsolved medical problem. Here we show for the first time targeted, subsurface ablation of atherosclerotic plaque using ultrafast laser pulses. Excised atherosclerotic mouse aortas were ablated with ultrafast near-infrared (NIR) laser pulses. The physical damage was characterized with histological sections of the ablated atherosclerotic arteries from six different mice. The ultrafast ablation system was integrated with optical coherence tomography (OCT) imaging for plaque-specific targeting and monitoring of the resulting ablation volume. We find that ultrafast ablation of plaque just below the surface is possible without causing damage to the fibrous cap, which indicates the potential use of ultrafast ablation for subsurface atherosclerotic plaque removal. We further demonstrate ex vivo subsurface ablation of a plaque volume through a catheter device with the high-energy ultrafast pulse delivered via hollow-core photonic crystal fiber.

  19. Immunochemical Characterization of Plaque Mutants of Simian Virus 40

    PubMed Central

    Ozer, H. L.; Takemoto, K. K.; Kirschstein, R. L.; Axelrod, D.

    1969-01-01

    Analysis of large and small plaque mutants of simian virus 40 using antisera prepared against each has revealed quantitative and possibly qualitative antigenic differences for each plaque type. A sensitive micro radioisotope precipitation test permitted evaluation of immunochemical similarities and differences of capsid antigens by inhibition of precipitation. PMID:4306300

  20. VIEW OF A BRONZE PLAQUE LOCATED AT THE FRONT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF A BRONZE PLAQUE LOCATED AT THE FRONT OF BUILDING 708. PLAQUE IS MOUNTED ON THE WALL JUST TO THE RIGHT SIDE OF THE CHAPEL'S ENTRANCE. - U.S. Naval Base, Pearl Harbor, Chapel, Corner of Oakley & Nimitz Street, Pearl City, Honolulu County, HI

  1. 24. View of one of the plaques from Clark Fork ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. View of one of the plaques from Clark Fork Vehicle Bridge. Presently located at the Bonner County Historical Museum in Sandpoint, Idaho. A plaque was attached at each end of the bridge. Only one remains. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  2. Adolescent (in)vulnerability.

    PubMed

    Quadrel, M J; Fischhoff, B; Davis, W

    1993-02-01

    Three groups of subjects were asked to judge the probability that they and several target others (a friend, an acquaintance, a parent, a child) would experience various risks. Subjects were middle-class adults, their teenage children, and high-risk adolescents from treatment homes. All three groups saw themselves as facing somewhat less risk than the target others. However, this perception of relative invulnerability was no more pronounced for adolescents than for adults. Indeed, the parents were viewed as less vulnerable than their teenage children by both the adults and those teens. These results are consistent with others showing small differences in the cognitive decision-making processes of adolescents and adults. Underestimating teens' competence can mean misdiagnosing the sources of their risk behaviors, denying them deserved freedoms, and failing to provide needed assistance.

  3. Automatic classification of atherosclerotic plaques imaged with intravascular OCT

    PubMed Central

    Rico-Jimenez, Jose J.; Campos-Delgado, Daniel U.; Villiger, Martin; Otsuka, Kenichiro; Bouma, Brett E.; Jo, Javier A.

    2016-01-01

    Intravascular optical coherence tomography (IV-OCT) allows evaluation of atherosclerotic plaques; however, plaque characterization is performed by visual assessment and requires a trained expert for interpretation of the large data sets. Here, we present a novel computational method for automated IV-OCT plaque characterization. This method is based on the modeling of each A-line of an IV-OCT data set as a linear combination of a number of depth profiles. After estimating these depth profiles by means of an alternating least square optimization strategy, they are automatically classified to predefined tissue types based on their morphological characteristics. The performance of our proposed method was evaluated with IV-OCT scans of cadaveric human coronary arteries and corresponding tissue histopathology. Our results suggest that this methodology allows automated identification of fibrotic and lipid-containing plaques. Moreover, this novel computational method has the potential to enable high throughput atherosclerotic plaque characterization. PMID:27867716

  4. Are herbal mouthwash efficacious over chlorhexidine on the dental plaque?

    PubMed Central

    Gupta, Devanand; Nayan, Swapna; Tippanawar, Harshad K.; Patil, Gaurav I.; Jain, Ankita; Momin, Rizwan K.; Gupta, Rajendra Kumar

    2015-01-01

    Aim: To compare the effect of herbal extract mouthwash and chlorhexidine mouthwash on the dental plaque level. Materials and Methods: The subjects (60 healthy medical students aged ranges between 20 and 25 years) were randomly divided into two groups, that is, the herbal group and the chlorhexidine gluconate mouthwash group. The data were collected at the baseline and 3 days. The plaque was disclosed using erythrosine disclosing agent and their scores were recorded using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Statistical analysis was carried out later to compare the effect of all the two groups. Results: Our result showed that the chlorhexidine group shows a greater decrease in plaque score followed by herbal extract, but the result was statistically insignificant. Conclusion: The results indicate that herbal mouthwash may prove to be an effective agent owing to its ability to reduce plaque level, especially in low socioeconomic strata. PMID:26130940

  5. Simplified dengue virus microwell plaque assay using an automated quantification program.

    PubMed

    Boonyasuppayakorn, Siwaporn; Suroengrit, Aphinya; Srivarangkul, Pimsiri; Yuttithamnon, Wanchalerm; Pankaew, Saran; Saelee, Thanaphon; Prompetchara, Eakachai; Salakij, Saran; Bhattarakosol, Parvapan

    2016-11-01

    The plaque assay is essential for virion quantitation but the classic protocol requires considerable efforts. A simplified dengue 96-well plaque assay with automated quantitation program is an alternative to access the level of infectious virus. Dengue plaque assay was simplified using LLC/MK2 cells and virus mixing simultaneously before semisolid addition. Results were obtained using a flatbed scanner and analysis by the self-written program optimized to manual reads. The newly developed microwell system was accurate to the standard assay because 19 independent titrations from all subtypes obtained from both systems differed less than a log10 p.f.u./ml with no significance (p>0.05) with good correlation (R(2)=0.9058). Coefficient of variations within and between assays, indicating assay reliability and repeatability, were 19.29%, and 12.50%, respectively. This method serves various experimental designs in drug discovery that requires viral titers assessment. Effective concentrations (EC90) results showed no significant difference between 24- and 96-well assays (p>0.05). Compound screening for potential antivirals and clinical isolate titrations were successfully arranged. The method contains distinguished features including protocol simplicity, less reagent consumption in microwell format, convenient and affordable data acquisition and analysis system.

  6. Refinement of the Modified Navy Plaque Index to increase plaque scoring efficiency in gumline and interproximal tooth areas.

    PubMed

    Rustogi, K N; Curtis, J P; Volpe, A R; Kemp, J H; McCool, J J; Korn, L R

    1992-01-01

    To improve the assessment of plaque present on teeth, a new index, based on the original Modified Navy Plaque Index, has been developed. The primary modifications to the original Modified Navy Plaque Index were: (1) extending areas F (distal) and D (mesial) into the region just below the interproximal contact point, and (2) extending areas C and A so as to increase the gumline (or marginal gingiva) region. The new index assesses the amount of plaque in the tooth area bounded by the tooth contact, the free gingival margin, and mesial or distal line angles. The use of this new index enables the examiner to evaluate and record both the gumline (or marginal areas) and interproximal areas of the tooth, thus giving these an anatomical areas an increased importance. A pilot clinical assessment study was conducted to utilize this new index in evaluating the plaque removal efficacy of five manual toothbrushes. The results from this pilot study indicated that, when the new plaque scoring index was used, significant differences between pre-toothbrushing and post-toothbrushing plaque scores (as well as among toothbrush groups) could be demonstrated. Further, these differences (plaque removal efficacy) were demonstrated on an interproximal (mesial and distal) basis and a gumline (or gingival margin) basis, as well as on a whole mouth basis.

  7. Accelerated Plaque Formation by Fowlpox Virus in the Presence of Chymotrypsin

    PubMed Central

    Asch, Bonnie B.; Gifford, George E.

    1969-01-01

    Chymotrypsin enhanced fowlpox virus plaque formation in chick embryo cell cultures. A simplified plaque assay for fowlpox virus is described. Plaques were produced in 3 days when chymotrypsin was included in a serum-free fluid overlay. Plaques were also produced in 5 to 6 days under an agar overlay when a medium containing fetal calf serum was employed. Kinetics of plaque formation were also studied, and it was shown that fowlpox virus plaque diameters grow at a linear rate. Images PMID:4905607

  8. Lower coronary plaque burden in patients with HIV presenting with acute coronary syndrome

    PubMed Central

    O'Dwyer, E J; Bhamra-Ariza, P; Rao, S; Emmanuel, S; Carr, A; Holloway, C J

    2016-01-01

    Objective Treated HIV infection is associated with a higher incidence of coronary artery disease and myocardial infarction, although the mechanisms remain unclear. We sought to characterise the burden of coronary artery disease in men with HIV using retrospective data from invasive coronary angiograms in patients presenting with acute coronary syndrome (ACS). Methods Demographic and coronary angiographic data were obtained from 160 men with ST elevation myocardial infarction, non-STEMI or high-risk chest pain; 73 HIV-infected cases and 87 age-matched controls. The burden of coronary disease was calculated using the Gensini Angiographic Scoring System by 2 independent cardiologists blinded to HIV status. Results The 2 groups were matched for age, sex and cardiac event subtype and there was no difference in rates of smoking or cholesterol levels. Compared with control participants, patients with HIV had higher usage of antihypertensives (46 (63%) vs 30 (35%), p<0.001) and statins (47 (64%) vs 29 (33%), p<0.001). There was no difference in plaque distribution between both groups; however, the Gensini score was 42% lower in cases with HIV than in controls (p<0.03). C reactive protein was higher in cases with HIV (13.4±15.4 vs 3.7±3.6). Conclusions Men with HIV presenting with ACS paradoxically had a lower burden of coronary plaque than matched controls, despite more aggressive risk factor management, suggesting that plaque vulnerability, rather than total burden of atherosclerosis, may be important in the pathophysiology of coronary artery disease in men with HIV. PMID:28123757

  9. Plaque Characteristics in Coronary Artery Disease Patients with Impaired Glucose Tolerance

    PubMed Central

    Suzuki, Keishi; Takano, Hitoshi; Kubota, Yoshiaki; Inui, Keisuke; Nakamura, Shunichi; Tokita, Yukichi; Kato, Koji; Asai, Kuniya; Shimizu, Wataru

    2016-01-01

    Background Impaired glucose tolerance (IGT) patients are known to have a high risk of cardiovascular events and their prognosis has been reported to be poor. The present study aimed to compare coronary plaque characteristics among coronary artery disease (CAD) patients with normal glucose tolerance (NGT), those with IGT, and those with diabetes mellitus (DM) by using optical coherence tomography (OCT). Methods The present study included 101 coronary artery disease patients (mean age, 67.9 ± 10.4 years; 82.4% male). OCT was performed for target and non-target vessels during percutaneous coronary intervention. The patients were divided into the following 3 groups: the NGT, IGT, and DM groups. Results A total of 136 non-target residual plaques were found in 101 patients (27, 30, and 44 in the NGT, IGT, and DM groups, respectively). The size of the lipid core expressed as the mean angle of the lipid arc was significantly greater in the IGT and DM groups than in the NGT group (163.0 ± 58.7°, 170.1 ± 59.3°, and 130.9 ± 37.7°, respectively, P < 0.05). The fibrous cap covering the lipid core was significantly thinner in the IGT group than in the NGT group (77.0 ± 23.4 μm vs. 105.6 ± 47.0 μm, P = 0.040). Conclusion The coronary plaques in CAD patients are more vulnerable when having IGT compared to those with NGT, and similar to those with DM. This finding may explain the high risk of cardiovascular events in CAD patients with IGT. PMID:27936195

  10. The Vulnerability of Elderly Consumers.

    ERIC Educational Resources Information Center

    McGhee, Jerrie L.

    1983-01-01

    Reviews research on the vulnerability of the elderly to consumer fraud. Patterns of consumption, situational characteristics, education and product knowledge, psychological losses, social isolation, and psychosocial transitions influence the elderly's vulnerability and ability to cope with consumer abuse. Higher educational attainment and greater…

  11. Preferential pharmacological inhibition of macrophage ACAT increases plaque formation in mouse and rabbit models of atherogenesis.

    PubMed

    Perrey, S; Legendre, C; Matsuura, A; Guffroy, C; Binet, J; Ohbayashi, S; Tanaka, T; Ortuno, J C; Matsukura, T; Laugel, T; Padovani, P; Bellamy, F; Edgar, A D

    2001-04-01

    The cholesteryl ester, foam cell-enriched vulnerable plaque is a principle pharmacological target for reducing athero-thrombosis. Acyl CoA:cholesterol Acyl Transferase (ACAT) catalyzes the esterification of free cholesterol in intestine, liver, adrenal and macrophages, leading in the latter cells to intracellular cholesteryl ester accumulation and foam cell formation in the arterial intima. Previous studies suggested the existence of several isoforms of ACAT with different tissue distribution and this has largely been confirmed by molecular cloning of ACAT-1 and ACAT-2. We developed a series of ACAT inhibitors that preferentially inhibited macrophage ACAT relative to hepatic or intestinal ACAT based on in vitro assays and ex vivo bioavailability studies. Four of these compounds were tested in three models of atherosclerosis at oral doses shown to give sufficient bioavailable monocyte/macrophage ACAT inhibitory activity. In fat-fed C57BL/6 mice, chow fed apo E-/- mice and KHC rabbits, the various ACAT inhibitors had either no effect or increased indices of atherosclerotic foam cell formation. Direct and indirect measurements suggest that the increase in plaque formation may have been related to inhibition of macrophage ACAT possibly leading to cytotoxic effects due to augmented free cholesterol. These results suggest that pharmacological inhibition of macrophage ACAT may not reduce, but actually aggravate, foam cell formation and progression.

  12. Inhaled diesel emissions alter atherosclerotic plaque composition in ApoE{sup -/-} mice

    SciTech Connect

    Campen, Matthew J.; Lund, Amie K.; Knuckles, Travis L.; Conklin, Daniel J.; Bishop, Barbara; Young, David; Seilkop, Steven; Seagrave, JeanClare; Reed, Matthew D.; McDonald, Jacob D.

    2010-02-01

    Recent epidemiological studies suggest that traffic-related air pollution may have detrimental effects on cardiovascular health. Previous studies reveal that gasoline emissions can induce several enzyme pathways involved in the formation and development of atherosclerotic plaques. As a direct comparison, the present study examined the impact of diesel engine emissions on these pathways, and further examined the effects on vascular lesion pathology. Apolipoprotein E-null mice were simultaneously placed on a high-fat chow diet and exposed to four concentrations, plus a high concentration exposure with particulates (PM) removed by filtration, of diesel emissions for 6 h/day for 50 days. Aortas were subsequently assayed for alterations in matrix metalloproteinase-9, endothelin-1, and several other biomarkers. Diesel induced dose-related alterations in gene markers of vascular remodeling and aortic lipid peroxidation; filtration of PM did not significantly alter these vascular responses, indicating that the gaseous portion of the exhaust was a principal driver. Immunohistochemical analysis of aortic leaflet sections revealed no net increase in lesion area, but a significant decrease in lipid-rich regions and increasing trends in macrophage accumulation and collagen content, suggesting that plaques were advanced to a more fragile, potentially more vulnerable state by diesel exhaust exposure. Combined with previous studies, these results indicate that whole emissions from mobile sources may have a significant role in promoting chronic vascular disease.

  13. Annexin A5-Functionalized Bimodal Nanoparticles for MRI and Fluorescence Imaging of Atherosclerotic Plaques

    PubMed Central

    van Tilborg, Geralda A. F.; Vucic, Esad; Strijkers, Gustav J.; Cormode, David P.; Mani, Venkatesh; Skajaa, Torjus; Reutelingsperger, Chris P. M.; Fayad, Zahi A.; Mulder, Willem J. M.; Nicolay, Klaas

    2011-01-01

    Apoptosis and macrophage burden are believed to correlate with atherosclerotic plaque vulnerability and are therefore considered important diagnostic and therapeutic targets for atherosclerosis. These cell types are characterized by the exposure of phosphatidylserine (PS) at their surface. In the present study, we developed and applied a small micellar fluorescent annexin A5-functionalized nanoparticle for noninvasive magnetic resonance imaging (MRI) of PS exposing cells in atherosclerotic lesions. Annexin A5-mediated target-specificity was confirmed with ellipsometry and in vitro binding to apoptotic Jurkat cells. In vivo T1-weighted MRI of the abdominal aorta in atherosclerotic ApoE−/− mice revealed enhanced uptake of the annexin A5-micelles as compared to control-micelles, which was corroborated with ex vivo near-infrared fluorescence images of excised whole aortas. Confocal laser scanning microscopy (CLSM) demonstrated that the targeted agent was associated with macrophages and apoptotic cells, whereas the nonspecific control agent showed no clear uptake by such cells. In conclusion, the annexin A5-conjugated bimodal micelles displayed potential for noninvasive assessment of cell types that are considered to significantly contribute to plaque instability and therefore may be of great value in the assessment of atherosclerotic lesion phenotype. PMID:20804153

  14. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  15. Effect of listerine on dental plaque and gingivitis.

    PubMed

    Fornell, J; Sundin, Y; Lindhe, J

    1975-01-01

    The present study was performed in 10 adults in order to evaluate the effect of an antiseptic mouthrinse (Listerine) on the rate of dental plaque formation and gingivitis development during a 2-week period when all efforts towards active mechanical oral hygiene were withdrawn. The study was performed as a crossover study and was carried out during four consecutive 2-week periods. During the first and third periods (preparatory periods) the participants were subjected to repeated professional tooth cleanings in order to establish plaque- and gingivitis-free dentitions. During the second and fourth periods (test and control periods) the participants were not allowed to brush their teeth but rinsed their mouths three times a day with Listerine or a placebo mouthwash. Plaque Index, Gingival Index, gingival fluid flow, and crevicular leukocytes were assessed on d 0, 2, 4, 7, and 14. On d 7 and 14, dental plaque was removed from the right and left jaws respectively and the wet weights determined. The chemotactic activity elaborated by the plaques was studied in Boyden chambers. During the Listerine test period, significantly lower Plaque and Gingival Index values were scored and lower amounts of plaque could be sampled in comparison to the control period.

  16. Sulfadiazines prevent plaque formation and gingivitis in beagles.

    PubMed

    Howell, T H; Reddy, M S; Weber, H P; Li, K L; Alfano, M C; Vogel, R; Tanner, A C; Williams, R C

    1990-07-01

    The effect of zinc sulfadiazine (ZnSD) and silver sulfadiazine (AgSD) on developing plaque formation and gingivitis was studied in 12 beagle dogs over a 14-week period. Plaque and gingival indices were used to measure plaque formation and gingivitis. During a 2-wk baseline period each dog was brought to optimal gingival health with prophylaxis and tooth brushing. Thereafter, 4 dogs were treated twice daily with topical application of 3.0% zinc sulfadiazine; 4 dogs were treated with 2.0% silver sulfadiazine while 4 dogs treated with placebo gel served as controls over a 12-wk treatment period. At wk 2 of treatment, all three groups of dogs showed an increase in plaque build-up on their teeth from baseline. By wk 6, plaque accumulation on the teeth was significantly less in dogs treated with either ZnSD or AgSD compared to control dogs. At wk 2 of treatment, gingival inflammation was increased from baseline in all three groups. Thereafter, over the course of the 12-wk treatment period, gingival inflammation in the ZnSD and the AgSD treated dogs was significantly less than the placebo treated dogs. The data indicate that both ZnSD and AgSD inhibit developing plaque formation in beagles. This significant inhibition of plaque formation was accompanied by a significant reduction in gingival inflammation.

  17. Systematic review of pleural plaques and lung function

    PubMed Central

    Kerper, Laura E.; Lynch, Heather N.; Zu, Ke; Tao, Ge; Utell, Mark J.

    2015-01-01

    Abstract Context US EPA proposed a Reference Concentration for Libby amphibole asbestos based on the premise that pleural plaques are adverse and cause lung function deficits. Objective We conducted a systematic review to evaluate whether there is an association between pleural plaques and lung function and ascertain whether results were dependent on the method used to identify plaques. Methods Using the PubMed database, we identified studies that evaluated pleural plaques and lung function. We assessed each study for quality, then integrated evidence and assessed associations based on the Bradford Hill guidelines. We also compared the results of HRCT studies to those of X-ray studies. Results We identified 16 HRCT and 36 X-ray studies. We rated six HRCT and 16 X-ray studies as higher quality based on a risk-of-bias analysis. Half of the higher quality studies reported small but statistically significant mean lung function decrements associated with plaques. None of the differences were clinically significant. Many studies had limitations, such as inappropriate controls and/or insufficient adjustment for confounders. There was little consistency in the direction of effect for the most commonly reported measurements. X-ray results were more variable than HRCT results. Pleural plaques were not associated with changes in lung function over time in longitudinal studies. Conclusion The weight of evidence indicates that pleural plaques do not impact lung function. Observed associations are most likely due to unidentified abnormalities or other factors. PMID:25518994

  18. CD44 Targeting Magnetic Glyconanoparticles for Atherosclerotic Plaque Imaging

    PubMed Central

    El-Dakdouki, Mohammad H.; El-Boubbou, Kheireddine; Kamat, Medha; Huang, Ruiping; Abela, George S.; Kiupel, Matti; Zhu, David C.; Huang, Xuefei

    2013-01-01

    Purpose The cell surface adhesion molecule CD44 plays important roles in the initiation and development of atherosclerotic plaques. We aim to develop nanoparticles that can selectively target CD44 for the non-invasive detection of atherosclerotic plaques by magnetic resonance imaging. Methods Magnetic glyco-nanoparticles with hyaluronan immobilized on the surface have been prepared. The binding of these nanoparticles with CD44 in vitro was evaluated by enzyme linked immunosorbent assay, flow cytometry and confocal microscopy. In vivo magnetic resonance imaging of plaques was performed on an atherosclerotic rabbit model. Results The magnetic glyconanoparticles can selectively bind CD44. In T2* weighted magnetic resonance images acquired in vivo, significant contrast changes in aorta walls were observed with a very low dose of the magnetic nanoparticles, allowing the detection of atherosclerotic plaques. Furthermore, imaging could be performed without significant delay after probe administration. The selectivity of hyaluronan nanoparticles in plaque imaging was established by several control experiments. Conclusions Magnetic nanoparticles bearing surface hyaluronan enabled the imaging of atherosclerotic plaques in vivo by magnetic resonance imaging. The low dose of nanoparticles required, the possibility to image without much delay and the high biocompatibility are the advantages of these nanoparticles as contrast agents for plaque imaging. PMID:23568520

  19. Schizophrenia: vulnerability versus disease.

    PubMed Central

    Tsuang, Ming T.; Stone, William S.; Faraone, Stephen V.

    2000-01-01

    One of the most important trends in the treatment of schizophrenia involves its early diagnosis and intervention. The ultimate goal of research is the prevention of the disorder, A major impediment to the development of prevention strategies, however, is that we do not yet know what the liability for schizophrenia is before the onset of psychosis. Consequently, early treatment attempts are focused on the “prodrome,” which involves the early symptoms of psychosis. In a companion paper, we recently suggested that prevention work should focus not only on the prodrome, but also on “schizotaxia,” which is a clinically meaningful condition that may reflect the vulnerability to schizophrenia in the absence of psychosis. Because schizotaxia can be assessed prior to the prodrome, studies of schizotaxia might lead to more effective prevention programs. We continue the characterization of schizotaxia in this paper by focusing on the etiological roots of schizotaxia, plus its likely neurodevelopmental course, clinical expression, and treatment. Finally, the importance of including neurobiological variables in the conceptualization and eventual diagnosis of schizotaxia is reviewed. PMID:22034456

  20. Butyrylcholinesterase in the life cycle of amyloid plaques.

    PubMed

    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.

  1. Hydrogen sulfide production from subgingival plaque samples.

    PubMed

    Basic, A; Dahlén, G

    2015-10-01

    Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3 < 7 mm) and 35% had severe periodontal breakdown (CAL > 7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket.

  2. Neutralization Assay for Chikungunya Virus Infection: Plaque Reduction Neutralization Test.

    PubMed

    Azami, Nor Azila Muhammad; Moi, Meng Ling; Takasaki, Tomohiko

    2016-01-01

    Neutralization assay is a technique that detects and quantifies neutralizing antibody in serum samples by calculating the percentage of reduction of virus activity, as the concentration of virus used is usually constant. Neutralizing antibody titer is conventionally determined by calculating the percentage reduction in total virus infectivity by counting and comparing number of plaques (localized area of infection due to cytopathic effect) with a standard amount of virus. Conventional neutralizing test uses plaque-reduction neutralization test (PRNT) to determine neutralizing antibody titers against Chikungunya virus (CHIKV). Here we describe the plaque reduction neutralization assay (PRNT) using Vero cell lines to obtain neutralizing antibody titers.

  3. The relationships between malocclusion, gingival inflammation, plaque and calculus.

    PubMed

    Buckley, L A

    1981-01-01

    Certain features of malocclusion considered important in relation to periodontal health were analyzed in a study of 300 subjects. It was found that plaque and gingival inflammation were not related to vertical incisor overbite, horizontal incisor overjet or posterior cuspal interdigitation. Individual tooth irregularity measured as tilting, rotation, displacement and crowding had a low but statistically significant correlation with plaque, calculus and gingival inflammation. However, the study showed that these features of malocclusion are far less important than the extent of plaque and calculus deposits in the development of gingival inflammation.

  4. Non-pulsed electrochemical impregnation of flexible metallic battery plaques

    DOEpatents

    Maskalick, Nicholas J.

    1982-01-01

    A method of loading active battery material into porous, flexible, metallic battery plaques, comprises the following steps: precipitating nickel hydroxide active material within the plaque, by making the plaque cathodic, at a high current density, in an electro-precipitation cell also containing a consumable nickel anode and a solution comprising nickel nitrate, having a pH of between 2.0 and 2.8; electrochemically oxidizing the precipitate in caustic formation solution; and repeating the electro-precipitation step at a low current density.

  5. Research with vulnerable human beings.

    PubMed

    Tangwa, Godfrey B

    2009-11-01

    Some categories of human beings are particularly vulnerable vis-à-vis medical research. Vulnerability could be considered as the liability to be harmed, exploited, deceived, cheated, wronged, or otherwise unfairly treated, in roughly that descending order of importance. Vulnerable human beings obviously include the incompetent (minors and mentally handicapped adults), the desperately poor, ill or ignorant, prisoners, refugees, pregnant women, subordinates in highly authoritarian systems, etc. Vulnerability in itself does not imply that no research whatsoever should be carried out with such categories of humans but only that it should be carried out only under very special conditions. In this paper I treat of vulnerability in research of particularly developing world populations; of the types of research which exploit such vulnerability, and of why and how research subjects should be protected. The aim in this paper is to stimulate practical reflection on the possible vulnerabilities of potential research subjects that researchers or investigators need to avoid exploiting rather than on an adequate theoretical treatment of the issue.

  6. BIOACCESSIBILITY TESTS ACCURATELY ESTIMATE ...

    EPA Pesticide Factsheets

    Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with P significantly reduced the bioavailability of Pb. The bioaccessibility of the Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter 24%, or present as Pb sulfate 18%. Ad

  7. Assessment of dental plaque by optoelectronic methods

    NASA Astrophysics Data System (ADS)

    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.

  8. Prolidase activity in chronic plaque psoriasis patients

    PubMed Central

    Aksoy, Nurten; Ozgöztas, Orhan; Sezen, Hatice; Yesilova, Yavuz; Turan, Enver

    2015-01-01

    Introduction Psoriasis is a chronic, inflammatory, T-cell-mediated and hyperproliferative skin disease characterized by erythematous, squamous, sharply circumscribed and infiltrated plaques. The metabolisms of the collagen proteins undergo considerable changes due to the acceleration of their turnovers as a result of increased prolidase activity in psoriasis patients. Aim To determine the level of prolidase activity in psoriasis patients and evaluate its relationship with the oxidative system. Material and methods The serum prolidase enzyme activity, total antioxidant levels and total oxidant levels of 40 psoriasis patients and a control group including 47 healthy individuals were analyzed by using their serum samples, and their oxidative stress indices were calculated. Results The prolidase levels (p < 0.01), total oxidant levels (p < 0.01) and oxidative stress index levels (p < 0.001) of the patient group were higher than the corresponding parameters in the control group. The total antioxidant level was low (p < 0.01). Although a positive correlation was found between the prolidase and total antioxidant levels and the total oxidant level, no correlation was found between prolidase and the oxidative stress index. Conclusions It has been determined that the activity of the prolidase enzyme increases due to the increased collage turnover in psoriasis patients. Increased serum oxidant levels and oxidative stress indices values may play a role in the pathogenesis of psoriasis. PMID:26015776

  9. Identifying Frailty Among Vulnerable Populations

    PubMed Central

    Salem, Benissa E.; Nyamathi, Adeline; Phillips, Linda R.; Mentes, Janet; Sarkisian, Catherine; Brecht, Lynn

    2014-01-01

    Frailty is a significant public health issue which is experienced by homeless and other vulnerable adults; to date, a frailty framework has not been proposed to guide researchers who study this hard-to-reach population. The Frailty Framework among Homeless and other Vulnerable Populations (FFHVP) has been developed from empirical research and consultation with frailty experts in an effort to characterize antecedents, i.e. situational, health-related, behavioral, resource, biological, and environmental factors which contribute to physical, psychological and social frailty domains and impact adverse outcomes. As vulnerable populations continue to age, a greater understanding of frailty will enable the development of nursing interventions. PMID:24469090

  10. Accurate spectral color measurements

    NASA Astrophysics Data System (ADS)

    Hiltunen, Jouni; Jaeaeskelaeinen, Timo; Parkkinen, Jussi P. S.

    1999-08-01

    Surface color measurement is of importance in a very wide range of industrial applications including paint, paper, printing, photography, textiles, plastics and so on. For a demanding color measurements spectral approach is often needed. One can measure a color spectrum with a spectrophotometer using calibrated standard samples as a reference. Because it is impossible to define absolute color values of a sample, we always work with approximations. The human eye can perceive color difference as small as 0.5 CIELAB units and thus distinguish millions of colors. This 0.5 unit difference should be a goal for the precise color measurements. This limit is not a problem if we only want to measure the color difference of two samples, but if we want to know in a same time exact color coordinate values accuracy problems arise. The values of two instruments can be astonishingly different. The accuracy of the instrument used in color measurement may depend on various errors such as photometric non-linearity, wavelength error, integrating sphere dark level error, integrating sphere error in both specular included and specular excluded modes. Thus the correction formulas should be used to get more accurate results. Another question is how many channels i.e. wavelengths we are using to measure a spectrum. It is obvious that the sampling interval should be short to get more precise results. Furthermore, the result we get is always compromise of measuring time, conditions and cost. Sometimes we have to use portable syste or the shape and the size of samples makes it impossible to use sensitive equipment. In this study a small set of calibrated color tiles measured with the Perkin Elmer Lamda 18 and the Minolta CM-2002 spectrophotometers are compared. In the paper we explain the typical error sources of spectral color measurements, and show which are the accuracy demands a good colorimeter should have.

  11. VIEW TO THE SOUTHEAST. MEMORIAL WITH BRONZE PLAQUE IN HONOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW TO THE SOUTHEAST. MEMORIAL WITH BRONZE PLAQUE IN HONOR OF KELLER, MARKS THE CENTER OF THE BRIDGE. - Keller Memorial Bridge, Spanning Tennessee River at U.S. Highway 31, Decatur, Morgan County, AL

  12. 38. 100 foot through truss bridge original identification plaque ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. 100 foot through truss - bridge original identification plaque located on the top of the north portal entrance. - Weidemeyer Bridge, Spanning Thomes Creek at Rawson Road, Corning, Tehama County, CA

  13. Clathrin and Cx43 gap junction plaque endoexocytosis

    SciTech Connect

    Nickel, Beth M.; DeFranco, B. Hewa; Gay, Vernon L.; Murray, Sandra A.

    2008-10-03

    In earlier transmission electron microscopic studies, we have described pentilaminar gap junctional membrane invaginations and annular gap junction vesicles coated with short, electron-dense bristles. The similarity between these electron-dense bristles and the material surrounding clathrin-coated pits led us to suggest that the dense bristles associated with gap junction structures might be clathrin. To confirm that clathrin is indeed associated with annular gap junction vesicles and gap junction plaques, quantum dot immuno-electron microscopic techniques were used. We report here that clathrin associates with both connexin 43 (Cx43) gap junction plaques and pentilaminar gap junction vesicles. An important finding was the preferential localization of clathrin to the cytoplasmic surface of the annular or of the gap junction plaque membrane of one of the two contacting cells. This is consistent with the possibility that the direction of gap junction plaque internalization into one of two contacting cells is regulated by clathrin.

  14. 13. SOUTHEAST OBELISK WITH PLAQUE COMMEMORATING CROSSING OF THE NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. SOUTHEAST OBELISK WITH PLAQUE COMMEMORATING CROSSING OF THE NORTH ANNA RIVER BY ARMY OF NORTHERN VIRGINIA MAY 22, 1864; LOOKING EAST - Fox Bridge No. 1936, Spanning North Anna River at U.S. Route 1, Ashland, Hanover County, VA

  15. GETTYSBURG ADDRESS AND NATIONAL REGISTER PLAQUES, WITH HEADSTONES IN BACKGROUND. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GETTYSBURG ADDRESS AND NATIONAL REGISTER PLAQUES, WITH HEADSTONES IN BACKGROUND. VIEW TO NORTHEAST. - Hot Springs National Cemetery, Virginia Medical Center 500 North Fifth Street, Hot Springs, Fall River County, SD

  16. A helical microwave antenna for welding plaque during balloon angioplasty

    SciTech Connect

    Liu, P.; Rappaport, C.M.

    1996-10-01

    A catheter-based microwave helix antenna has been developed in an attempt to improve the long-term success of balloon angioplasty treatment of arteriosclerosis. When the balloon is inflated to widen vessels obstructed with plaque, microwave power is deposited in the plaque, heating it, and thereby fixing it in place. By optimizing the helix pitch angle and excitation frequency, the antenna radiation pattern can be adjusted to deposit microwave power preferentially in the plaque while avoiding overheating the healthy artery. The optimal power deposition patterns of helical antennas are analytically computed for four-layered concentric and four-layered nonconcentric cylindrical geometries, which model symmetric and asymmetric occluded arteries. Experiments were performed on occluded artery phantom models with a prototype antenna for both symmetric and asymmetric models, which matched the theoretical predictions well, indicating almost complete power absorption in the low-water-content simulated plaque.

  17. 32. STUDIO VIEW OF PLAQUE PLACED ON MILL HOUSE AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. STUDIO VIEW OF PLAQUE PLACED ON MILL HOUSE AT TIME OF COMPLETION, COMMEMORATING EDWARD J. LUKE (SEE TEXT) - Sperry Corn Elevator Complex, Weber Avenue (North side), West of Edison Street, Stockton, San Joaquin County, CA

  18. 5. DETAIL VIEW, LOOKING WEST, SHOWING STONE PLAQUE INSCRIBED 'USRA, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. DETAIL VIEW, LOOKING WEST, SHOWING STONE PLAQUE INSCRIBED 'USRA, 1936' LOCATED IN EAST ELEVATION (tHIS PHOTOGRAPH IS FOGGED) - Spring Lake Bridge, Spanning Bob Barnes Branch at County Road No. 36D, Belleville, Yell County, AR

  19. Detail of aluminum plaque attached to the top of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of aluminum plaque attached to the top of the northwest pilaster, facing west. - Oakland Avenue Viaduct, Oakland Avenue spanning U.S. Route 62 (State Route 2302) & Pine Run, Sharon, Mercer County, PA

  20. Limestone and bronze "Mississippi River Crossing" Bridge plaque located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Limestone and bronze "Mississippi River Crossing" Bridge plaque located at North corner of Administration Building site - Huey P. Long Bridge, Administration Building, 5100 Jefferson Highway, Jefferson, Jefferson Parish, LA

  1. 30. Bronze plaque located on southern inner wall at east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Bronze plaque located on southern inner wall at east end of south pier taken looking southeast - Duluth Ship Canal, South Pier, North end of Minnesota Point & Canal Park, Duluth, St. Louis County, MN

  2. Plaque formation and marginal gingivitis associated with restorative materials.

    PubMed

    Litonjua, Luis A; Cabanilla, Leyvee L; Abbott, Lawrence J

    2011-05-01

    The presence of restorative materials on tooth surfaces is perceived to be a contributing factor to periodontal disease. This observation is a result of the increased accumulation of plaque on restorations adjacent to the gingiva, which may lead to gingivitis. Plaque is believed to adhere better to restorations than to enamel. This may be due to the surface characteristics of restorative materials such as surface roughness and surface-free energy inherent in the materials. This article reviews the experimental studies of plaque formation on different restorative materials. In addition, clinical studies analyzing and comparing restorative materials and the consequent formation of gingivitis are reviewed. While in vitro and in vivo studies show variations in plaque formation among restorative materials and enamel, clinical studies demonstrate that the progression of gingivitis can be prevented if patients maintain adequate oral hygiene and home care. Therefore, instructing the patient to maintain proper oral hygiene and home care is more important than the choice of restorative material.

  3. Plaque formation and marginal gingivitis associated with restorative materials.

    PubMed

    Litonjua, Luis A; Cabanilla, Leyvee L; Abbott, Lawrence J

    2012-01-01

    The presence of restorative materials on tooth surfaces is perceived to be a contributing factor to periodontal disease. This observation is a result of the increased accumulation of plaque on restorations adjacent to the gingiva, which may lead to gingivitis. Plaque is believed to adhere better to restorations than to enamel. This may be due to the surface characteristics of restorative materials such as surface roughness and surface-free energy inherent in the materials. This article reviews the experimental studies of plaque formation on different restorative materials. In addition, clinical studies analyzing and comparing restorative materials and the consequent formation of gingivitis are reviewed. While in vitro and in vivo studies show variations in plaque formation among restorative materials and enamel, clinical studies demonstrate that the progression of gingivitis can be prevented if patients maintain adequate oral hygiene and home care. Therefore, instructing the patient to maintain proper oral hygiene and home care is more important than the choice of restorative material.

  4. Elevation view of dedication plaque on east wall of south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation view of dedication plaque on east wall of south lobby - National Home for Disabled Volunteer Soldiers, Pacific Branch, Main Mental Health Building, 11301 Wilshire Boulevard, West Los Angeles, Los Angeles County, CA

  5. A patient with plaque type morphea mimicking systemic lupus erythematosus.

    PubMed

    Wardhana; Datau, E A

    2015-04-01

    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.

  6. 6. VIEW OF COMMEMORATIVE PLAQUE, EAST APPROACH GUARDRAIL, WHICH STATES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF COMMEMORATIVE PLAQUE, EAST APPROACH GUARDRAIL, WHICH STATES 'SALINE RIVER; ARK. GENERAL CONST. CO.; CONTRACTOR; ARKANSAS; STATE HIGHWAY DEPARTMENT; 1928, BRIDGE NO. __.' - Saline River Bridge, County Highway 365 across Saline River, Benton, Saline County, AR

  7. Coronary plaque imaging by coronary computed tomography angiography

    PubMed Central

    Sato, Akira

    2014-01-01

    Coronary computed tomography angiography (CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coronary artery disease (CAD). With the development of technical aspects of coronary CTA, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes by coronary CTA. In this review we discuss the coronary plaque morphology estimated by CTA beyond coronary angiography including the comparison to the currently available other imaging modalities used to examine morphological characteristics of the atherosclerotic plaque. Furthermore, this review underlies the value of a combined assessment of coronary anatomy and myocardial perfusion in patients with CAD, and adds to an increasing body of evidence suggesting an added diagnostic value when combining both modalities. We hope that an integrated, multi-modality imaging approach will become the gold standard for noninvasive evaluation of coronary plaque morphology and outcome data in clinical practice. PMID:24876919

  8. Detail of plaque beneath column on the south parapet at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of plaque beneath column on the south parapet at the west end of the bridge. The plaque reads “1914; Mayor E.J. Drussel; Councilmen E.S. Henry, E.F. Hogan, R.P. Lamdin, C.F. Ross, J.H. Shuppert; Leonard & Day, Engineers; C.H. Gildersleeve, Builder.” - First Street Bridge, Spanning Napa River at First Street between Soscol Avenue & Juarez Street, Napa, Napa County, CA

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

    PubMed Central

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

    2013-01-01

    SUMMARY 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. Aim Purpose of this study was to determine in vivo the retention of plaque on three different elastic ligatures, in comparison with stainless steel ligature, to determine a possible association between type of ligatures and accumulation of microorganisms. Material and Methods three elastic ligation systems were analyzed for plaque retention: ring-shape, clear, latex ligatures (Leone® Spa), ring-shape, grey, polyurethane ligatures (Micerium® Spa) and grey, polyurethane, Slide low-friction ligatures (Leone® Spa), compared with stainless steel ligatures (Leone® Spa) used as control. Forthy orthodontic patients undergoing fixed orthodontic therapy were selected. A sample for each type of ligature were applied inside the oral cavity of each subject. Samples were kept in the oral cavity for 28 days, ligating 0.16 X 0.22 stainless steel archwire to stainless steel orthodontic premolars brackets. The presence of bacterical slime was quantified by spectrophotometric method (crystal violet-Bouin’s fixative) and morphological observations was evaluated by Scanning Electron Microscopy (SEM). Results From analysis of bacterical slime emerges that all the elastics showed a low plaque retention, especially if compared to the group of steinless steel ligatures, that presented a greater plaque adhesion, statistically significant compared to the Slide group (r<0.0002) and the two elastic groups (r<0.0001). This study reported no significant difference between the Slide ligatures and the traditional elastic ligatures as regards the retention of plaque. SEM images showed presence of cocci, rods and few filamentous organisms and an interbacterial matrix in all observed samples. Conclusion Elastomeric ligatures showed a significant lower susceptibility

  10. Urease and Dental Plaque Microbial Profiles in Children

    PubMed Central

    Morou-Bermudez, Evangelia; Rodriguez, Selena; Bello, Angel S.; Dominguez-Bello, Maria G.

    2015-01-01

    Objective Urease enzymes produced by oral bacteria generate ammonia, which can have a significant impact on the oral ecology and, consequently, on oral health. To evaluate the relationship of urease with dental plaque microbial profiles in children as it relates to dental caries, and to identify the main contributors to this activity. Methods 82 supragingival plaque samples were collected from 44 children at baseline and one year later, as part of a longitudinal study on urease and caries in children. DNA was extracted; the V3–V5 region of the 16S rRNA gene was amplified and sequenced using 454 pyrosequencing. Urease activity was measured using a spectrophotometric assay. Data were analyzed with Qiime. Results Plaque urease activity was significantly associated with the composition of the microbial communities of the dental plaque (Baseline P = 0.027, One Year P = 0.012). The bacterial taxa whose proportion in dental plaque exhibited significant variation by plaque urease levels in both visits were the family Pasteurellaceae (Baseline P<0.001; One Year P = 0.0148), especially Haemophilus parainfluenzae. No association was observed between these bacteria and dental caries. Bacteria in the genus Leptotrichia were negatively associated with urease and positively associated with dental caries (Bonferroni P<0.001). Conclusions Alkali production by urease enzymes primarily from species in the family Pasteurellaceae can be an important ecological determinant in children’s dental plaque. Further studies are needed to establish the role of urease-associated bacteria in the acid/base homeostasis of the dental plaque, and in the development and prediction of dental caries in children. PMID:26418220

  11. [Is dental plaque a normal Helicobacter pylori reservoir?].

    PubMed

    Améndola, R; Roldán, C D; Morgade, L; Solagna, A; Lineado, A; Musi, A O; Valero, J; Zerbo, O; Kogan, Z; Ferro, F E; Schenone, L; Corti, R

    1998-01-01

    The mechanisms of transmission and reservoir of Helicobacter pylori is still unclear; even it has been suggested that dental plaque could be the bacterial reservoir and one important factor in the reinfection. The aim of the study was to evaluate the prevalence of Helicobacter pylori in dental plaque in 20 patients with non ulcer dyspepsia (12 females, 7 males; mean age 40.5 years) and antral infection; and to establish the presence of bacteria in dental plaque and gastric mucosa after eradication. Gastric colonization in all of them was confirmed by five samples (three of antrum and two of body) with Giemsa conventional technique, clotest and culture. When clotest was positive in gastric mucosa, we performed the scrape of dental plaque and sending the material for culture. All patients were treated with a scheme of seven days with one protom pump inhibitor and two antibiotics. After four weeks all the patients were controlled with endoscopy and culture of dental plaque to confirm eradication. Dental plaque culture was positive in 1/20 patients (5%), and this results was similar to developed countries, using as detection method culture or polymerase chain reaction (PCR).

  12. Automatic plaque assay for the pharmaceutical industry using machine vision

    NASA Astrophysics Data System (ADS)

    Wilder, Joseph; Tsai, Augustine; Festa, J. M.

    1995-10-01

    A crucial step in the manufacture of vaccines is the verification of their potency. An assay of the potency must be carried out on every batch produced to determine the safety and efficacy of the vaccine. Currently, human inspectors count the number of plaques (holes) in a cell layer in a petri dish to estimate the potency.They must determine whether nearby plaques that have overgrown each other's borders are single or multiple plaques and distinguish between plaques and small tears in the cell layer resulting from the processing operations (the edges of tears differ in appearance from the edges of plaques). Because of the judgments required to make these subtle distinctions, human inspectors are inconsistent. In cooperation with Merck & Co., Inc., the Rutgers University Center for Computer Aids for Industrial Productivity has demonstrated the feasibility of achieving consistent automatic counting of plaques by a prototype intelligent machine vision system. The David Sarnoff Research Center developed materials handling equipment and factory information system interfaces to enable this prototype system to be installed in a quality control facility at Merck. This paper describes the overall operation of the machine vision aspects of the system, including optics, illumination, sensing, preprocessing, feature extraction and shape recognition. Results of initial tests of the system are also reported.

  13. "Show me the money": vulnerability to gambling moderates the attractiveness of money versus suspense.

    PubMed

    Hahn, Cheryl; Wilson, Timothy D; McRae, Kaichen; Gilbert, Daniel T

    2013-10-01

    Do people take risks to obtain rewards or experience suspense? We hypothesized that people vulnerable to gambling are motivated more by the allure of winning money whereas people less vulnerable to gambling are motivated more by the allure of suspense. Consistent with this hypothesis, participants with high scores on a subscale of the Gambling Attitudes and Beliefs Survey--a measure of vulnerability to gambling--reported more of a motivation to earn money (pilot study), were more likely to accept a certain or near-certain amount of money than to gamble for that same amount (Studies 1-2), and worked harder to earn money (Study 3). People vulnerable to gambling also made more accurate predictions about how much they would gamble. People less vulnerable to gambling, in contrast, gambled more than people vulnerable to gambling, but did not know that they would.

  14. Cholesterol-independent effects of atorvastatin prevent cardiovascular morbidity and mortality in a mouse model of atherosclerotic plaque rupture.

    PubMed

    Roth, Lynn; Rombouts, Miche; Schrijvers, Dorien M; Martinet, Wim; De Meyer, Guido R Y

    2016-05-01

    Because cholesterol-independent effects of statins are difficult to determine in patients, we studied these pleiotropic effects in apolipoprotein E-deficient (ApoE(-/-)) mice with a mutation in the fibrillin-1 gene (Fbn1(C1039G+/-)). These mice develop exacerbated atherosclerosis and spontaneous plaque ruptures, accompanied by myocardial infarctions (MI) and sudden death. ApoE(-/-)Fbn1(C1039G+/-) mice were fed a Western diet (WD). At week 10 of WD, mice were divided in a control (WD), atorvastatin (10mg/kg/day + WD) and cholesterol withdrawal group (cholW, normal chow). The latter was included to compare the effects of atorvastatin with dietary lipid lowering. Fifteen weeks later, the mice were sacrificed. CholW, but not atorvastatin, reduced plasma cholesterol. Survival increased from 50% to 90% both in cholW and atorvastatin treated mice. CholW as well as atorvastatin treatment increased plaque collagen and fibrous cap thickness, but they did not affect the amount of plaque macrophages and T cells. MMP-2 and MMP-9 activity was significantly lower and the expression of MMP-12, TNF-α and IL-1β was strongly reduced in both treatment groups. Blood monocytes and neutrophils returned to baseline levels (ApoE(-/-) mice before the onset of atherosclerosis). Importantly, atorvastatin but not cholW significantly reduced coronary stenosis (from 50 to 28%) and the occurrence of MI (from 43 to 10%). In conclusion, independent of cholesterol lowering, atorvastatin significantly reduced mortality, plaque vulnerability and inflammation to the same extent as cholW. In addition, atorvastatin but not cholW reduced coronary stenosis and the occurrence of MI. These data unequivocally illustrate the significance of the pleiotropic effects of atorvastatin in the prevention of cardiovascular morbidity and mortality.

  15. I-125 ROPES eye plaque dosimetry: Validation of a commercial 3D ophthalmic brachytherapy treatment planning system and independent dose calculation software with GafChromic{sup ®} EBT3 films

    SciTech Connect

    Poder, Joel; Corde, Stéphanie

    2013-12-15

    Purpose: The purpose of this study was to measure the dose distributions for different Radiation Oncology Physics and Engineering Services, Australia (ROPES) type eye plaques loaded with I-125 (model 6711) seeds using GafChromic{sup ®} EBT3 films, in order to verify the dose distributions in the Plaque Simulator™ (PS) ophthalmic 3D treatment planning system. The brachytherapy module of RADCALC{sup ®} was used to independently check the dose distributions calculated by PS. Correction factors were derived from the measured data to be used in PS to account for the effect of the stainless steel ROPES plaque backing on the 3D dose distribution.Methods: Using GafChromic{sup ®} EBT3 films inserted in a specially designed Solid Water™ eye ball phantom, dose distributions were measured three-dimensionally both along and perpendicular to I-125 (model 6711) loaded ROPES eye plaque's central axis (CAX) with 2 mm depth increments. Each measurement was performed in full scatter conditions both with and without the stainless steel plaque backing attached to the eye plaque, to assess its effect on the dose distributions. Results were compared to the dose distributions calculated by Plaque Simulator™ and checked independently with RADCALC{sup ®}.Results: The EBT3 film measurements without the stainless steel backing were found to agree with PS and RADCALC{sup ®} to within 2% and 4%, respectively, on the plaque CAX. Also, RADCALC{sup ®} was found to agree with PS to within 2%. The CAX depth doses measured using EBT3 film with the stainless steel backing were observed to result in a 4% decrease relative to when the backing was not present. Within experimental uncertainty, the 4% decrease was found to be constant with depth and independent of plaque size. Using a constant dose correction factor of T= 0.96 in PS, where the calculated dose for the full water scattering medium is reduced by 4% in every voxel in the dose grid, the effect of the plaque backing was accurately

  16. Targeted Delivery of Shear Stress-Inducible Micrornas by Nanoparticles to Prevent Vulnerable Atherosclerotic Lesions

    PubMed Central

    Wong, Wing Tak; Ma, Shuangtao; Tian, Xiao Yu; Gonzalez, Andrea Banuet; Ebong, Eno E.; Shen, Haifa

    2016-01-01

    Atherosclerosis is a chronic inflammatory vascular wall disease, and endothelial cell dysfunction plays an important role in its development and progression. Under the influence of laminar shear stress, however, the endothelium releases homeostatic factors such as nitric oxide and expresses of vasoprotective microRNAs that are resistant to atherosclerosis. Adhesion molecules such as E-selectin, exhibited on the endothelial surface, recruit monocytes that enter the vessel wall to form foam cells. Accumulation of these foam cells form fatty streaks that may progress to atherosclerotic plaques in the blood vessel wall. Interestingly, E-selectin may also serve as an affinity moiety for targeted drug delivery against atherosclerosis. We have recently developed an E-selectin-targeted platform that enriches therapeutic microRNAs in the inflamed endothelium to inhibit formation of vulnerable atherosclerotic plaques. PMID:27826369

  17. Clinical and Pathological Insights into the Dynamic Nature of the White Matter Multiple Sclerosis Plaque

    PubMed Central

    Frischer, Josa M.; Weigand, Stephen D.; Guo, Yong; Kale, Nilufer; Parisi, Joseph E.; Pirko, Istvan; Mandrekar, Jay; Bramow, Stephan; Metz, Imke; Brück, Wolfgang; Lassmann, Hans; Lucchinetti, Claudia F.

    2015-01-01

    Background An extensive analysis of white matter plaques in a large sample of MS autopsies provides insights into the dynamic nature of MS pathology. Methods 120 MS cases (1220 tissue blocks) were included. Plaque types were classified according to demyelinating activity based on stringent criteria. Early-active, late-active, smoldering, inactive, and shadow plaques were distinguished. 2476 MS white matter plaques were identified. Plaque type distribution was analyzed in relation to clinical data. Findings Active plaques were most often found in early disease, whereas at later stages, smoldering, inactive and shadow plaques predominated. The presence of early-active plaques rapidly declined with disease duration. Plaque type distribution differed significantly by clinical course. The majority of plaques in acute-monophasic and RRMS were active. Among SPMS cases with attacks, all plaque types could be distinguished including active plaques, in contrast to SPMS without attacks in whom inactive plaques predominated. Smoldering plaques were frequently and almost exclusively found in progressive MS. At 47-years of age, an equilibrium was observed between active and inactive plaques, whereas smoldering plaques began to peak. Men displayed a higher proportion of smoldering plaques. Interpretation Disease duration, clinical course, age and gender contribute to the dynamic nature of white matter MS pathology. Active MS plaques predominate in acute and early RRMS and are the likely substrate of clinical attacks. Progressive MS transitions to an accumulation of smoldering plaques characterized by microglial activation and slow expansion of pre-existing plaques. Whether current MS therapeutics impact this pathological driver of disease progression remains uncertain. PMID:26239536

  18. High throughput object-based image analysis of β-amyloid plaques in human and transgenic mouse brain.

    PubMed

    Samaroo, Harry D; Opsahl, Alan C; Schreiber, Jan; O'Neill, Sharon M; Marconi, Michael; Qian, Jessie; Carvajal-Gonzalez, Santos; Tate, Barbara; Milici, Anthony J; Bales, Kelly R; Stephenson, Diane T

    2012-02-15

    Advances in imaging technology have enabled automated approaches for quantitative image analysis. In this study, a high content object based image analysis method was developed for quantification of β-amyloid (Aβ) plaques in postmortem brains of Alzheimer's disease (AD) subjects and in transgenic mice over overexpressing Aβ. Digital images acquired from immunohistochemically stained sections of the superior frontal gyrus were analyzed for Aβ plaque burden using a Definiens object-based segmentation approach. Blinded evaluation of Aβ stained sections from AD and aged matched human subjects accurately identified AD cases with one exception. Brains from transgenic mice overexpressing Aβ (PS1APP mice) were also evaluated by our Definiens object based image analysis approach. We observed an age-dependent increase in the amount of Aβ plaque load that we quantified in both the hippocampus and cortex. From the contralateral hemisphere, we measured the amount of Aβ in brain homogenates biochemically and observed a significant correlation between our biochemical measurements and those that we measured by our object based Definiens system in the hippocampus. Assessment of Aβ plaque load in PS1APP mice using a manual segmentation technique (Image-Pro Plus) confirmed the results of our object-based image analysis approach. Image acquisition and analysis of 32 stained human slides and 100 mouse slides were executed in 8 h and 22 h, respectively supporting the relatively high throughput features of the Definiens platform. The data show that digital imaging combined with object based image analysis is a reliable and efficient approach to quantifying Aβ plaques in human and mouse brain.

  19. Combined orcein and martius scarlet blue (OMSB) staining for qualitative and quantitative analyses of atherosclerotic plaques in brachiocephalic arteries in apoE/LDLR(-/-) mice.

    PubMed

    Gajda, Mariusz; Jasztal, Agnieszka; Banasik, Tomasz; Jasek-Gajda, Ewa; Chlopicki, Stefan

    2017-02-06

    Numerous cellular and extracellular components should be analyzed in sections of atherosclerotic plaques to assess atherosclerosis progression and vulnerability. Here, we combined orcein (O) staining for elastic fibers and martius scarlet blue (MSB) polychrome to visualize various morphological contents of plaque in brachiocephalic arteries (BCA) of apoE/LDLR(-/-) mice. Elastic fibers (including broken elastic laminae and 'buried' fibrous caps) were stained purple and they could be easily distinguished from collagen fibers (blue). Orcein allowed clear identification of even the finest elastic fibers. Erythrocytes were stained yellow and they could easily be discerned from mature fibrin (red). Old fibrin tends to acquire blue color. The method of OMSB staining is simple, takes less than 1 h to perform and can be adapted to automatic stainers. Most importantly, the color separation is good enough to allow digital automatic segmentation of specific components in tissue section and quantitative analysis of the plaque constituents. OMSB was used to compare atherosclerotic plaques in proximal and distal regions of BCA in apoE/LDLR(-/-) mice. In conclusion, OMSB staining represents a novel staining that could be routinely used for qualitative and quantitative microscopic assessments of formaldehyde-fixed and paraffin-embedded sections of arteries with atherosclerotic lesions.

  20. The Role of Intracoronary Plaque Imaging with Intravascular Ultrasound, Optical Coherence Tomography, and Near-Infrared Spectroscopy in Patients with Coronary Artery Disease.

    PubMed

    Hoang, Vu; Grounds, Jill; Pham, Don; Virani, Salim; Hamzeh, Ihab; Qureshi, Athar Mahmood; Lakkis, Nasser; Alam, Mahboob

    2016-09-01

    The development of multiple diagnostic intracoronary imaging modalities has increased our understanding of coronary atherosclerotic disease. These imaging modalities, intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near-infrared spectroscopy (NIRS), have provided a method to study plaques and introduced the concept of plaque vulnerability. They are being increasingly used for percutaneous coronary intervention (PCI) optimization and are invaluable tools in research studying the pathophysiology of acute coronary syndrome (ACS), in-stent thrombosis and in-stent restenosis. IVUS has the ability to visualize the intracoronary lumen and the vessel wall and can be used to detect early atherosclerotic disease even in the setting of positive arterial remodeling. Studies supporting the use of IVUS to optimize stent deployment and apposition have shown a significant reduction in cardiovascular events. OCT provides even higher resolution imaging and near microscopic detail of plaques, restenoses, and thromboses; thus, it can identify the etiology of ACS. Ongoing trials are evaluating the role of OCT in PCI and using OCT to study stent endothelialization and neointimal proliferation. NIRS is a modality capable of localizing and quantifying lipid core burden. It is usually combined with IVUS and is used to characterize plaque composition. The benefits of NIRS in the setting of ACS have been limited to case reports and series. The utilization of all these intracoronary imaging modalities will continue to expand as their indications for clinical use and research grow. Studies to support their use for PCI optimization resulting in improved outcomes with potential to prevent downstream events are ongoing.

  1. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

    SciTech Connect

    Lesperance, Marielle; Inglis-Whalen, M.; Thomson, R. M.

    2014-02-15

    simulation by up to 16%. In the full eye model simulations, the average dose to the lens is larger by 7%–9% than the dose to the center of the lens, and the maximum dose to the optic nerve is 17%–22% higher than the dose to the optic disk for all radionuclides. In general, when normalized to the same prescription dose at the tumor apex, doses delivered to all structures of interest in the full eye model are lowest for{sup 103}Pd and highest for {sup 131}Cs, except for the tumor where the average dose is highest for {sup 103}Pd and lowest for {sup 131}Cs. Conclusions : The eye is not radiologically water-equivalent, as doses from simulations of the plaque in the full eye model differ considerably from doses for the plaque in a water phantom and from simulated TG-43 calculated doses. This demonstrates the importance of model-based dose calculations for eye plaque brachytherapy, for which accurate elemental compositions of ocular media are necessary.

  2. Groundwater vulnerability on small islands

    NASA Astrophysics Data System (ADS)

    Holding, S.; Allen, D. M.; Foster, S.; Hsieh, A.; Larocque, I.; Klassen, J.; van Pelt, S. C.

    2016-12-01

    The majority of naturally occurring freshwater on small islands is groundwater, which is primarily recharged by precipitation. Recharge rates are therefore likely to be impacted by climate change. Freshwater resources on small islands are particularly vulnerable to climate change because they are limited in size and easily compromised. Here we have compiled available aquifer system characteristics and water-use data for 43 small island developing states distributed worldwide, based on local expert knowledge, publications and regional data sets. Current vulnerability was assessed by evaluating the recharge volume per capita. For future vulnerability, climate change projections were used to estimate changes in aquifer recharge. We find that 44% of islands are in a state of water stress, and while recharge is projected to increase by as much as 117% on 12 islands situated in the western Pacific and Indian Ocean, recharge is projected to decrease by up to 58% on the remaining 31 islands. Of great concern is the lack of enacted groundwater protection legislation for many of the small island developing states identified as highly vulnerable to current and future conditions. Recharge indicators, shown alongside the state of legal groundwater protections, provide a global picture of groundwater supply vulnerability under current and future climate change conditions.

  3. Dual-modal magnetic resonance and fluorescence imaging of atherosclerotic plaques in vivo using VCAM-1 targeted tobacco mosaic virus.

    PubMed

    Bruckman, Michael A; Jiang, Kai; Simpson, Emily J; Randolph, Lauren N; Luyt, Leonard G; Yu, Xin; Steinmetz, Nicole F

    2014-03-12

    The underlying cause of major cardiovascular events, such as myocardial infarctions and strokes, is atherosclerosis. For accurate diagnosis of this inflammatory disease, molecular imaging is required. Toward this goal, we sought to develop a nanoparticle-based, high aspect ratio, molecularly targeted magnetic resonance (MR) imaging contrast agent. Specifically, we engineered the plant viral nanoparticle platform tobacco mosaic virus (TMV) to target vascular cell adhesion molecule (VCAM)-1, which is highly expressed on activated endothelial cells at atherosclerotic plaques. To achieve dual optical and MR imaging in an atherosclerotic ApoE(-/-) mouse model, TMV was modified to carry near-infrared dyes and chelated Gd ions. Our results indicate molecular targeting of atherosclerotic plaques. On the basis of the multivalency and multifunctionality, the targeted TMV-based MR probe increased the detection limit significantly; the injected dose of Gd ions could be further reduced 400x compared to the suggested clinical use, demonstrating the utility of targeted nanoparticle cargo delivery.

  4. Are Vulnerability Disclosure Deadlines Justified?

    SciTech Connect

    Miles McQueen; Jason L. Wright; Lawrence Wellman

    2011-09-01

    Vulnerability research organizations Rapid7, Google Security team, and Zero Day Initiative recently imposed grace periods for public disclosure of vulnerabilities. The grace periods ranged from 45 to 182 days, after which disclosure might occur with or without an effective mitigation from the affected software vendor. At this time there is indirect evidence that the shorter grace periods of 45 and 60 days may not be practical. However, there is strong evidence that the recently announced Zero Day Initiative grace period of 182 days yields benefit in speeding up the patch creation process, and may be practical for many software products. Unfortunately, there is also evidence that the 182 day grace period results in more vulnerability announcements without an available patch.

  5. Low copper and high manganese levels in prion protein plaques

    USGS Publications Warehouse

    Johnson, Christopher J.; Gilbert, P.U.P.A.; Abrecth, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; McKenzie, Debbie

    2013-01-01

    Accumulation of aggregates rich in an abnormally folded form of the prion protein characterize the neurodegeneration caused by transmissible spongiform encephalopathies (TSEs). The molecular triggers of plaque formation and neurodegeneration remain unknown, but analyses of TSE-infected brain homogenates and preparations enriched for abnormal prion protein suggest that reduced levels of copper and increased levels of manganese are associated with disease. The objectives of this study were to: (1) assess copper and manganese levels in healthy and TSE-infected Syrian hamster brain homogenates; (2) determine if the distribution of these metals can be mapped in TSE-infected brain tissue using X-ray photoelectron emission microscopy (X-PEEM) with synchrotron radiation; and (3) use X-PEEM to assess the relative amounts of copper and manganese in prion plaques in situ. In agreement with studies of other TSEs and species, we found reduced brain levels of copper and increased levels of manganese associated with disease in our hamster model. We also found that the in situ levels of these metals in brainstem were sufficient to image by X-PEEM. Using immunolabeled prion plaques in directly adjacent tissue sections to identify regions to image by X-PEEM, we found a statistically significant relationship of copper-manganese dysregulation in prion plaques: copper was depleted whereas manganese was enriched. These data provide evidence for prion plaques altering local transition metal distribution in the TSE-infected central nervous system.

  6. Uniaxial tensile testing approaches for characterisation of atherosclerotic plaques.

    PubMed

    Walsh, M T; Cunnane, E M; Mulvihill, J J; Akyildiz, A C; Gijsen, F J H; Holzapfel, G A

    2014-03-03

    The pathological changes associated with the development of atherosclerotic plaques within arterial vessels result in significant alterations to the mechanical properties of the diseased arterial wall. There are several methods available to characterise the mechanical behaviour of atherosclerotic plaque tissue, and it is the aim of this paper to review the use of uniaxial mechanical testing. In the case of atherosclerotic plaques, there are nine studies that employ uniaxial testing to characterise mechanical behaviour. A primary concern regarding this limited cohort of published studies is the wide range of testing techniques that are employed. These differing techniques have resulted in a large variance in the reported data making comparison of the mechanical behaviour of plaques from different vasculatures, and even the same vasculature, difficult and sometimes impossible. In order to address this issue, this paper proposes a more standardised protocol for uniaxial testing of diseased arterial tissue that allows for better comparisons and firmer conclusions to be drawn between studies. To develop such a protocol, this paper reviews the acquisition and storage of the tissue, the testing approaches, the post-processing techniques and the stress-strain measures employed by each of the nine studies. Future trends are also outlined to establish the role that uniaxial testing can play in the future of arterial plaque mechanical characterisation.

  7. Antiinflammatory actions of inorganic nitrate stabilize the atherosclerotic plaque

    PubMed Central

    Khambata, Rayomand S.; Ghosh, Suborno M.; Rathod, Krishnaraj S.; Thevathasan, Tharssana; Filomena, Federica; Xiao, Qingzhong; Ahluwalia, Amrita

    2017-01-01

    Reduced bioavailable nitric oxide (NO) plays a key role in the enhanced leukocyte recruitment reflective of systemic inflammation thought to precede and underlie atherosclerotic plaque formation and instability. Recent evidence demonstrates that inorganic nitrate (NO3−) through sequential chemical reduction in vivo provides a source of NO that exerts beneficial effects upon the cardiovascular system, including reductions in inflammatory responses. We tested whether the antiinflammatory effects of inorganic nitrate might prove useful in ameliorating atherosclerotic disease in Apolipoprotein (Apo)E knockout (KO) mice. We show that dietary nitrate treatment, although having no effect upon total plaque area, caused a reduction in macrophage accumulation and an elevation in smooth muscle accumulation within atherosclerotic plaques of ApoE KO mice, suggesting plaque stabilization. We also show that in nitrate-fed mice there is reduced systemic leukocyte rolling and adherence, circulating neutrophil numbers, neutrophil CD11b expression, and myeloperoxidase activity compared with wild-type littermates. Moreover, we show in both the ApoE KO mice and using an acute model of inflammation that this effect upon neutrophils results in consequent reductions in inflammatory monocyte expression that is associated with elevations of the antiinflammatory cytokine interleukin (IL)-10. In summary, we demonstrate that inorganic nitrate suppresses acute and chronic inflammation by targeting neutrophil recruitment and that this effect, at least in part, results in consequent reductions in the inflammatory status of atheromatous plaque, and suggest that this effect may have clinical utility in the prophylaxis of inflammatory atherosclerotic disease. PMID:28057862

  8. Plaque autofluorescence as potential diagnostic targets for oral malodor

    NASA Astrophysics Data System (ADS)

    Lee, Eun-Song; Yim, Hyun-Kyung; Lee, Hyung-Suk; Choi, Jong-Hoon; Kwon, Ho-Keun; Kim, Baek-Il

    2016-08-01

    The aim of this study was to determine whether the degree of tongue and interdental plaque can be used to assess oral malodor by quantifying their fluorescence as detected using quantitative light-induced fluorescence (QLF) technology. Ninety-nine subjects who complained of oral malodor were included. The level of oral malodor was quantified using the organoleptic score (OLS) and the concentration of volatile sulfur compounds (VSCs). The fluorescence properties of tongue and interdental plaque were quantified as scores calculated by multiplying the intensity and area of fluorescence in QLF-digital images, and the combined plaque fluorescence (CPF) score was obtained by summing the scores for the two regions. The associations of the scores with malodor levels and the diagnostic accuracy of the CPF score were analyzed. The two plaque fluorescence scores and their combined score differed significantly with the level of oral malodor (p<0.001). The CPF score was moderately correlated with OLS (r=0.64) and VSC levels (r=0.54), and its area under the receiver operating characteristic curve was 0.77 for identifying subjects with definite oral malodor (OLS≥2). In conclusion, plaque fluorescence from tongue and interdental sites as detected using QLF technology can be used to assess the level of oral malodor.

  9. Cyber / Physical Security Vulnerability Assessment Integration

    SciTech Connect

    MacDonald, Douglas G.; Simpkins, Bret E.

    2012-07-28

    Abstract Both physical protection and cyber security domains offer solutions for the discovery of vulnerabilities through the use of various assessment processes and software tools. Each vulnerability assessment (VA) methodology provides the ability to identify and categorize vulnerabilities, and quantifies the risks within their own areas of expertise. Neither approach fully represents the true potential security risk to a site and/or a facility, nor comprehensively assesses the overall security posture. The technical approach to solving this problem was to identify methodologies and processes that blend the physical and cyber security assessments, and develop tools to accurately quantify the unaccounted for risk. SMEs from both the physical and the cyber security domains developed the blending methodologies, and cross trained each other on the various aspects of the physical and cyber security assessment processes. A local critical infrastructure entity volunteered to host a proof of concept physical/cyber security assessment, and the lessons learned have been leveraged by this effort. The four potential modes of attack an adversary can use in approaching a target are; Physical Only Attack, Cyber Only Attack, Physical Enabled Cyber Attack, and the Cyber Enabled Physical Attack. The Physical Only and the Cyber Only pathway analysis are two of the most widely analyzed attack modes. The pathway from an off-site location to the desired target location is dissected to ensure adversarial activity can be detected and neutralized by the protection strategy, prior to completion of a predefined task. This methodology typically explores a one way attack from the public space (or common area) inward towards the target. The Physical Enabled Cyber Attack and the Cyber Enabled Physical Attack are much more intricate. Both scenarios involve beginning in one domain to affect change in the other, then backing outward to take advantage of the reduced system effectiveness, before

  10. The retina dose-area histogram: a metric for quantitatively comparing rival eye plaque treatment options

    PubMed Central

    2013-01-01

    Purpose Episcleral plaques have a history of over a half century in the delivery of radiation therapy to intraocular tumors such as choroidal melanoma. Although the tumor control rate is high, vision-impairing complications subsequent to treatment remain an issue. Notable, late complications are radiation retinopathy and maculopathy. The obvious way to reduce the risk of radiation damage to the retina is to conform the prescribed isodose surface to the tumor base and to reduce the dose delivered to the surrounding healthy retina, especially the macula. Using a fusion of fundus photography, ultrasound and CT images, tumor size, shape and location within the eye can be accurately simulated as part of the radiation planning process. In this work an adaptation of the dose-volume histogram (DVH), the retina dose-area histogram (RDAH) is introduced as a metric to help compare rival plaque designs and conformal treatment planning options with the goal of reducing radiation retinopathy. Material and methods The RDAH is calculated by transforming a digitized fundus-photo collage of the tumor into a rasterized polar map of the retinal surface known as a retinal diagram (RD). The perimeter of the tumor base is digitized on the RD and its area computed. Area and radiation dose are calculated for every pixel in the RD. Results The areal resolution of the RDAH is a function of the pixel resolution of the raster image used to display the RD and the number of polygon edges used to digitize the perimeter of the tumor base. A practical demonstration is presented. Conclusions The RDAH provides a quantitative metric by which episcleral plaque treatment plan options may be evaluated and compared in order to confirm adequate dosimetric coverage of the tumor and margin, and to help minimize dose to the macula and retina. PMID:23634152

  11. Behavior of spindles and spindle plaques in the cell cycle and conjugation of Saccharomyces cerevisiae.

    PubMed Central

    Byers, B; Goetsch, L

    1975-01-01

    The interdependence of spindle plaque with other aspects of cell division and conjugation in Saccharomyces cerevisiae has been investigated. Three forms of the spindle plaque appear sequentially before the formation of the complete, intranuclear spindle. The single plaque is present initially in the mitotic cycle; it becomes transformed into a satellite-bearing single plaque during the latter part of G1. Subsequently, plaque duplication yields the double plaque characteristic of the early phase of budding, which coincides with the period of chromosome replication (S). The eventual separation of these plaques to form a complete spindle, with a single plaque at each pole, is nearly coincident with the completion of S. The form of the plaque differs in two independent cases of G1 arrest: the single plaque is found in a cell in stationary arrest of growth, whereas a cell arrested by mating factors in preparation for conjugation contains a satellite-bearing single plaque. The latter form is retained during zygote formation, where it serves as the initial site of fusion of each prezygotic nuceus with the other. This fusion results in the formation of a single zygotic nucleus with a satellite-bearing single plaque, which is subsequently transformed into a double plaque as the zygote buds. The double plaque is situated adjacent to the site of bud emergence in both vegetative cells and zygotes. Images PMID:1100612

  12. Bioenergetic Mechanisms in Astrocytes May Contribute to Amyloid Plaque Deposition and Toxicity*

    PubMed Central

    Fu, Wen; Shi, Diya; Westaway, David; Jhamandas, Jack H.

    2015-01-01

    Alzheimer disease (AD) is characterized neuropathologically by synaptic disruption, neuronal loss, and deposition of amyloid β (Aβ) protein in brain structures that are critical for memory and cognition. There is increasing appreciation, however, that astrocytes, which are the major non-neuronal glial cells, may play an important role in AD pathogenesis. Unlike neurons, astrocytes are resistant to Aβ cytotoxicity, which may, in part, be related to their greater reliance on glycolytic metabolism. Here we show that, in cultures of human fetal astrocytes, pharmacological inhibition or molecular down-regulation of a main enzymatic regulator of glycolysis, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase (PFKFB3), results in increased accumulation of Aβ within and around astrocytes and greater vulnerability of these cells to Aβ toxicity. We further investigated age-dependent changes in PFKFB3 and astrocytes in AD transgenic mice (TgCRND8) that overexpress human Aβ. Using a combination of Western blotting and immunohistochemistry, we identified an increase in glial fibrillary acidic protein expression in astrocytes that paralleled the escalation of the Aβ plaque burden in TgCRND8 mice in an age-dependent manner. Furthermore, PFKFB3 expression also demonstrated an increase in these mice, although at a later age (9 months) than GFAP and Aβ. Immunohistochemical staining showed significant reactive astrogliosis surrounding Aβ plaques with increased PFKFB3 activity in 12-month-old TgCRND8 mice, an age when AD pathology and behavioral deficits are fully manifested. These studies shed light on the unique bioenergetic mechanisms within astrocytes that may contribute to the development of AD pathology. PMID:25814669

  13. Bifurcation analysis of a model for atherosclerotic plaque evolution

    NASA Astrophysics Data System (ADS)

    Bulelzai, M. A. K.; Dubbeldam, J. L. A.; Meijer, H. G. E.

    2014-06-01

    We analyze two ordinary differential equation (ODE) models for atherosclerosis. The ODE models describe long time evolution of plaques in arteries. We show how the dynamics of the first atherosclerosis model (model A) can be understood using codimension-two bifurcation analysis. The Low-Density Lipoprotein (LDL) intake parameter (d) is the first control parameter and the second control parameter is either taken to be the conversion rate of macrophages (b) or the wall shear stress (σ). Our analysis reveals that in both cases a Bogdanov-Takens (BT) point acts as an organizing center. The bifurcation diagrams are calculated partly analytically and to a large extent numerically using AUTO07 and MATCONT. The bifurcation curves show that the concentration of LDL in the plaque as well as the monocyte and the macrophage concentrations exhibit oscillations for a certain range of values of the control parameters. Moreover, we find that there are threshold values for both the cholesterol intake rate dcrit and the conversion rate of the macrophages bcrit, which depend on the values of other parameters, above which the plaque volume increases with time. It is found that larger conversion rates of macrophages lower the threshold value of cholesterol intake and vice versa. We further argue that the dynamics for model A can still be discerned in the second model (model B) in which the slow evolution of the radius of the artery is coupled self-consistently to changes in the plaque volume. The very slow evolution of the radius of the artery compared to the other processes makes it possible to use a slow manifold approximation to study the dynamics in this case. We find that in this case the model predicts that the concentrations of the plaque constituents may go through a period of oscillations before the radius of the artery will start to decrease. These oscillations hence act as a precursor for the reduction of the artery radius by plaque growth.

  14. Effects of plaque lengths on stent surface roughness.

    PubMed

    Syaifudin, Achmad; Takeda, Ryo; Sasaki, Katsuhiko

    2015-01-01

    The physical properties of the stent surface influence the effectiveness of vascular disease treatment after stent deployment. During the expanding process, the stent acquires high-level deformation that could alter either its microstructure or the magnitude of surface roughness. This paper constructed a finite element simulation to observe the changes in surface roughness during the stenting process. Structural transient dynamic analysis was performed using ANSYS, to identify the deformation after the stent is placed in a blood vessel. Two types of bare metal stents are studied: a Palmaz type and a Sinusoidal type. The relationship between plaque length and the changes in surface roughness was investigated by utilizing three different length of plaque; plaque length longer than the stent, shorter than the stent and the same length as the stent. In order to reduce computational time, 3D cyclical and translational symmetry was implemented into the FE model. The material models used was defined as a multilinear isotropic for stent and hyperelastic for the balloon, plaque and vessel wall. The correlation between the plastic deformation and the changes in surface roughness was obtained by intermittent pure tensile test using specimen whose chemical composition was similar to that of actual stent material. As the plastic strain is achieved from FE simulation, the surface roughness can be assessed thoroughly. The study found that the plaque size relative to stent length significantly influenced the critical changes in surface roughness. It was found that the length of stent which is equal to the plaque length was preferable due to the fact that it generated only moderate change in surface roughness. This effect was less influential to the Sinusoidal stent.

  15. Ability of combined Near-Infrared Spectroscopy-Intravascular Ultrasound (NIRS-IVUS) imaging to detect lipid core plaques and estimate cap thickness in human autopsy coronary arteries

    NASA Astrophysics Data System (ADS)

    Grainger, S. J.; Su, J. L.; Greiner, C. A.; Saybolt, M. D.; Wilensky, R. L.; Raichlen, J. S.; Madden, S. P.; Muller, J. E.

    2016-03-01

    The ability to determine plaque cap thickness during catheterization is thought to be of clinical importance for plaque vulnerability assessment. While methods to compositionally assess cap integrity are in development, a method utilizing currently available tools to measure cap thickness is highly desirable. NIRS-IVUS is a commercially available dual imaging method in current clinical use that may provide cap thickness information to the skilled reader; however, this is as yet unproven. Ten autopsy hearts (n=15 arterial segments) were scanned with the multimodality NIRS-IVUS catheter (TVC Imaging System, Infraredx, Inc.) to identify lipid core plaques (LCPs). Skilled readers made predictions of cap thickness over regions of chemogram LCP, using NIRS-IVUS. Artery segments were perfusion fixed and cut into 2 mm serial blocks. Thin sections stained with Movat's pentachrome were analyzed for cap thickness at LCP regions. Block level predictions were compared to histology, as classified by a blinded pathologist. Within 15 arterial segments, 117 chemogram blocks were found by NIRS to contain LCP. Utilizing NIRSIVUS, chemogram blocks were divided into 4 categories: thin capped fibroatheromas (TCFA), thick capped fibroatheromas (ThCFA), pathological intimal thickening (PIT)/lipid pool (no defined cap), and calcified/unable to determine cap thickness. Sensitivities/specificities for thin cap fibroatheromas, thick cap fibroatheromas, and PIT/lipid pools were 0.54/0.99, 0.68/0.88, and 0.80/0.97, respectively. The overall accuracy rate was 70.1% (including 22 blocks unable to predict, p = 0.075). In the absence of calcium, NIRS-IVUS imaging provided predictions of cap thickness over LCP with moderate accuracy. The ability of this multimodality imaging method to identify vulnerable coronary plaques requires further assessment in both larger autopsy studies, and clinical studies in patients undergoing NIRS-IVUS imaging.

  16. Vulnerability in research ethics: a way forward.

    PubMed

    Lange, Margaret Meek; Rogers, Wendy; Dodds, Susan

    2013-07-01

    Several foundational documents of bioethics mention the special obligation researchers have to vulnerable research participants. However, the treatment of vulnerability offered by these documents often relies on enumeration of vulnerable groups rather than an analysis of the features that make such groups vulnerable. Recent attempts in the scholarly literature to lend philosophical weight to the concept of vulnerability are offered by Luna and Hurst. Luna suggests that vulnerability is irreducibly contextual and that Institutional Review Boards (Research Ethics Committees) can only identify vulnerable participants by carefully examining the details of the proposed research. Hurst, in contrast, defines the vulnerable as those especially at risk of incurring the wrongs to which all research ethics participants are exposed. We offer a more substantive conception of vulnerability than Luna but one that gives rise to a different rubric of responsibilities from Hurst's. While we understand vulnerability to be an ontological condition of human existence, in the context of research ethics, we take the vulnerable to be research subjects who are especially prone to harm or exploitation. Our analysis rests on developing a typology of sources of vulnerability and showing how distinct sources generate distinct obligations on the part of the researcher. Our account emphasizes that the researcher's first obligation is not to make the research participant even more vulnerable than they already are. To illustrate our framework, we consider two cases: that of a vulnerable population involved in international research and that of a domestic population of people with diminished capacity.

  17. Interactive Vulnerability Analysis Enhancement Results

    DTIC Science & Technology

    2012-12-01

    PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD- MM -YYYY) DECEMBER 2012 2. REPORT TYPE FINAL TECHNICAL REPORT 3. DATES...application. Here is a screenshot of IAST finding a Cross-Site Scripting (XSS) vulnerability in a “ Hello World” Scala application: Approved for Public

  18. Glaciology: Vulnerable Antarctic ice shelves

    NASA Astrophysics Data System (ADS)

    Siegert, Martin

    2017-01-01

    The decay of floating ice shelves around Antarctica speeds up ice flow from the continent and contributes to increased sea-level rise. Now, meltwater attributed to warm winds has been discovered on an East Antarctic ice shelf, suggesting greater vulnerability than previously thought.

  19. The Vulnerability Assessment & Mitigation Methodology

    DTIC Science & Technology

    2003-01-01

    Defense Systems........................................ 111 A.37. Vulnerabilities That Can Be Incurred from Vaccination ........... 112 A.38...protect against future threats or system failures while mitigating current and past threats and weaknesses. Also, sophisticated adver - saries are...and recovery • Adaptability and learning • Immunological defense systems • Vaccination ISR and Self-Awareness • Intelligence operations • Self

  20. Dosimetric study of the 15 mm ROPES eye plaque

    SciTech Connect

    Granero, D.; Perez-Calatayud, J.; Ballester, F.; Casal, E.; Frutos, J.M. de

    2004-12-01

    The main aim of this paper is to make a study of dose-rate distributions obtained around the 15 mm, radiation oncology physics and engineering services, Australia (ROPES) eye plaque loaded with {sup 125}I model 6711 radioactive seeds. In this study, we have carried out a comparison of the dose-rate distributions obtained by the algorithm used by the Plaque Simulator (PS) (BEBIG GmbH, Berlin, Germany) treatment planning system with those obtained by means of the Monte Carlo method for the ROPES eye plaque. A simple method to obtain the dose-rate distributions in a treatment planning system via the superposition of the dose-rate distributions of a seed placed in the eye plaque has been developed. The method uses eye plaque located in a simplified geometry of the head anatomy and distributions obtained by means of the Monte Carlo code GEANT4. The favorable results obtained in the development of this method suggest that it could be implemented on a treatment planning system to improve dose-rate calculations. We have also found that the dose-rate falls sharply along the eye and that outside the eye the dose-rate is very low. Furthermore, the lack of backscatter photons from the air located outside the eye-head phantom produces a dose reduction negligible for distances from the eye-plaque r<1 cm but reaches up to 20% near the air-eye interface. Results showed that the treatment planning system lacks accuracy around the border of the eye (in the sclera and the surrounding area) due to the simplicity of the algorithm used. The BEBIG treatment planning system uses a global attenuation factor that takes into account the effect of the eye plaque seed carrier and the lack of backscatter photons caused by the metallic cover, which in the case of a ROPES eye plaque has a default value of T=1 (no correction). In the present study, a global attenuation factor T=0.96 and an air-interface correction factor which improve on treatment planning system calculations were obtained.

  1. Parameter on plaque-induced gingivitis. American Academy of Periodontology.

    PubMed

    2000-05-01

    The American Academy of Periodontology has developed the following parameter on plaque-induced gingivitis in the absence of clinical attachment loss. Plaque-induced gingivitis is the most common form of the periodontal diseases, affecting a significant portion of the population in susceptible individuals. Patients should be informed of the disease process, therapeutic alternatives, potential complications, expected results, and their responsibility in treatment. Consequences of no treatment should be explained. No treatment may result in continuation of clinical signs of disease, with possible development of gingival defects and progression to periodontitis. Given this information, patients should then be able to make informed decisions regarding their periodontal therapy.

  2. Method of making a light weight battery plaque

    NASA Technical Reports Server (NTRS)

    Reid, M. A.; Post, R. E.; Soltis, D. G. (Inventor)

    1984-01-01

    A nickel plaque which may be coated with a suitable metal or compound to make an electrode for a fuel cell or battery is fabricated by directing nickel sensitizer, catalyst and plating solutions through a porous plastic substrate in the order named and at prescribed temperatures and flow rates. A boride compound dissolved in the plating solution decreases the electrical resistance of the plaque. Certain substrates may require treatment in an alkali solution to dissolve filler materials thereby increasing porosity to a required 65%.

  3. Peptidic targeting of phosphatidylserine for the MRI detection of apoptosis in atherosclerotic plaques.

    PubMed

    Burtea, Carmen; Laurent, Sophie; Lancelot, Eric; Ballet, Sébastien; Murariu, Oltea; Rousseaux, Olivier; Port, Marc; Vander Elst, Luce; Corot, Claire; Muller, Robert N

    2009-01-01

    Molecular and cellular imaging of atherosclerosis has garnered more interest at the beginning of the 21st century, with aims to image in vivo biological properties of plaque lesions. Apoptosis seems an attractive target for the diagnosis of vulnerable atherosclerotic plaques prone to a thrombotic event. The aim of the present work was to screen for apoptosis peptide binders by phage display with the final purpose to detect apoptotic cells in atherosclerotic plaques by magnetic resonance imaging (MRI). A phosphatidylserine-specific peptide identified by phage display was thus used to design an MRI contrast agent (CA), which was evaluated as a potential in vivo reporter of apoptotic cells. A library of linear 6-mer random peptides was screened in vitro against immobilized phosphatidylserine. Phage DNA was isolated and sequenced, and the affinity of peptides for phosphatidylserine was evaluated by enzyme-linked immunosorbent assay. The phosphatidylserine-specific peptide and its scrambled homologue were attached to a linker and conjugated to DTPA-isothiocyanate. The products were purified by dialysis and by column chromatography and complexed with gadolinium chloride. After their evaluation using apoptotic cells and a mouse model of liver apoptosis, the phosphatidylserine-targeted CA was used to image atherosclerotic lesions on ApoE(-/-) transgenic mice. Apoptotic cells were detected on liver and aorta specimens by the immunostaining of phosphatidylserine and of active caspase-3. Sequencing of the phage genome highlighted nine different peptides. Their alignment with amino acid sequences of relevant proteins revealed a frequent homology with Ca2+ channels, reminiscent of the function of annexins. Alignment with molecules involved in apoptosis provides a direct correlation between peptide selection and utility. The in vivo MRI studies performed at 4.7 T provide proof of concept that apoptosis-related pathologies could be diagnosed by MRI with a low molecular weight

  4. Using GA-Ridge regression to select hydro-geological parameters influencing groundwater pollution vulnerability.

    PubMed

    Ahn, Jae Joon; Kim, Young Min; Yoo, Keunje; Park, Joonhong; Oh, Kyong Joo

    2012-11-01

    For groundwater conservation and management, it is important to accurately assess groundwater pollution vulnerability. This study proposed an integrated model using ridge regression and a genetic algorithm (GA) to effectively select the major hydro-geological parameters influencing groundwater pollution vulnerability in an aquifer. The GA-Ridge regression method determined that depth to water, net recharge, topography, and the impact of vadose zone media were the hydro-geological parameters that influenced trichloroethene pollution vulnerability in a Korean aquifer. When using these selected hydro-geological parameters, the accuracy was improved for various statistical nonlinear and artificial intelligence (AI) techniques, such as multinomial logistic regression, decision trees, artificial neural networks, and case-based reasoning. These results provide a proof of concept that the GA-Ridge regression is effective at determining influential hydro-geological parameters for the pollution vulnerability of an aquifer, and in turn, improves the AI performance in assessing groundwater pollution vulnerability.

  5. The nature of iron deposits differs between symptomatic and asymptomatic carotid atherosclerotic plaques

    DOE PAGES

    Kopriva, David; Kisheev, Anastasye; Meena, Deiter; ...

    2015-11-25

    Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophagesmore » with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. Moreover, the abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin.« less

  6. The nature of iron deposits differs between symptomatic and asymptomatic carotid atherosclerotic plaques

    SciTech Connect

    Kopriva, David; Kisheev, Anastasye; Meena, Deiter; Pelle, Shaneen; Karnitsky, Max; Lavoie, Andrea; Buttigieg, Josef; Hagemeyer, Christoph E.

    2015-11-25

    Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophages with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. Moreover, the abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin.

  7. SU-E-T-443: Geometric Uncertainties in Eye Plaque Dosimetry for a Fully Loaded 16 Mm COMS Plaque

    SciTech Connect

    Morrison, H; Menon, G; Jans, H; Larocque, M; Sloboda, R

    2015-06-15

    Purpose: To determine the effect of geometric uncertainties in the seed positions in a COMS eye plaque on the central axis (CAX) dose. Methods: A Silastic insert was placed into a photopolymer 3D printed 16 mm COMS plaque, which was then positioned onto a custom-designed PMMA eye phantom. High resolution 3D images were acquired of the setup using a Siemens Inveon microPET/CT scanner. Images were acquired with the plaque unloaded and loaded with IsoAid I-125 seed shells (lack of silver core to minimize metal artifacts). Seed positions and Silastic thickness beneath each slot were measured. The measured seed coordinates were used to alter the seed positions within a standard 16 mm COMS plaque in Plaque Simulator v5.7.3 software. Doses along the plaque CAX were compared for the original and modified plaque coordinates using 3.5 mCi seeds with treatment times set to deliver 70 Gy to tumour apexes of 3.5, 5, and 10 mm height. Results: The majority of seeds showed length-wise displacement, and all seeds showed displacement radially outward from the eye center. The average radial displacement was 0.15 mm larger than the expected 1.4 mm offset, approximately half of which was due to increased Silastic thickness beneath each slot. The CAX doses for the modified seed positions were consistently lower for all tumour heights due to geometric displacement of the seeds; dose differences were found to increase to a maximum of 2.6% at a depth of ∼10 mm, after which they decreased due to the inverse square dose fall-off minimizing this effect. Conclusion: This work presents initial results of a broader dosimetric uncertainty evaluation for fully loaded COMS eye plaques and demonstrates the effects of seed positioning uncertainties. The small shifts in seed depths had noticeable effects on the CAX doses indicating the importance of careful Silastic loading. Funding provided by Alberta Cancer Foundation Grant #26655, Vanier Canada Graduate Scholarship, and Alberta Innovates Health

  8. Assessing European wild fire vulnerability

    NASA Astrophysics Data System (ADS)

    Oehler, F.; Oliveira, S.; Barredo, J. I.; Camia, A.; Ayanz, J. San Miguel; Pettenella, D.; Mavsar, R.

    2012-04-01

    Wild fire vulnerability is a measure of potential socio-economic damage caused by a fire in a specific area. As such it is an important component of long-term fire risk management, helping policy-makers take informed decisions about adequate expenditures for fire prevention and suppression, and to target those regions at highest risk. This paper presents a first approach to assess wild fire vulnerability at the European level. A conservative approach was chosen that assesses the cost of restoring the previous land cover after a potential fire. Based on the CORINE Land Cover, a restoration cost was established for each land cover class at country level, and an average restoration time was assigned according to the recovery capacity of the land cover. The damage caused by fire was then assessed by discounting the cost of restoring the previous land cover over the restoration period. Three different vulnerability scenarios were considered assuming low, medium and high fire severity causing different levels of damage. Over Europe, the potential damage of wild land fires ranges from 10 - 13, 732 Euro*ha-1*yr-1 for low fire severity, 32 - 45,772 Euro*ha-1*yr-1 for medium fire severity and 54 - 77,812 Euro*ha-1*yr-1 for high fire severity. The least vulnerable are natural grasslands, moors and heathland and sclerophyllous vegetation, while the highest cost occurs for restoring broad-leaved forest. Preliminary validation comparing these estimates with official damage assessments for past fires shows reasonable results. The restoration cost approach allows for a straightforward, data extensive assessment of fire vulnerability at European level. A disadvantage is the inherent simplification of the evaluation procedure with the underestimation of non-markets goods and services. Thus, a second approach has been developed, valuing individual wild land goods and services and assessing their annual flow which is lost for a certain period of time in case of a fire event. However

  9. Fermentation of five sucrose isomers by human dental plaque bacteria.

    PubMed

    Matsuyama, J; Sato, T; Hoshino, E; Noda, T; Takahashi, N

    2003-01-01

    Sucrose has five structural isomers: palatinose, trehalulose, turanose, maltulose and leucrose. Although these isomers have been reported to be noncariogenic disaccharides, which cannot be utilized by mutans streptococci, there is no information about their fermentability by other bacteria in dental plaque. The purpose of the present study was to examine whether these isomers were fermented by predominant bacteria in human dental plaque. Clinical bacterial isolates obtained from dental plaque from 3 children aged 22 months to 50 months (146 strains) were inoculated into 3 ml of peptone-yeast extract (PY medium) containing glucose for 1 day, then an aliquot of 20 microl of culture medium was inoculated into 1 ml of PY medium containing 1% (w/v) of the respective test carbohydrates. After incubation for 1 day, the pH values and the optical density at 660 nm of the cultures were measured. Fermentation ability was measured by pH or=0.5. Of the clinical isolates, 33% fermented palatinose, and 69% of these were Actinomyces species. All of the palatinose-fermenting bacterial strains fermented trehalulose, 25% fermented turanose, 70% fermented maltulose and 23% fermented leucrose. We therefore conclude that, in human dental plaque, there are significant numbers of bacteria that are able to ferment sucrose isomers.

  10. 6. VIEW OF BRIDGE COMMEMORATIVE PLAQUE WHICH STATES '1908, J. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF BRIDGE COMMEMORATIVE PLAQUE WHICH STATES '1908, J. H. CROOKS, ED. ELLIS, A. S. LELAND, COMMISSIONERS. L. E. BRELSFORD, AUDITOR. L. WEST, SURVEYOR. - B. C. GERWICK, DESIGNER. F. E. WITHCOTT, ENG. ON CONST. C. A. WARNER, CONTRACTOR.' - First Street Reinforced Concrete Bridge, Spanning Moxahala Creek at First Street (CR 7), Roseville, Muskingum County, OH

  11. Congenital plaque-type glomuvenous malformation associated with chylous ascites.

    PubMed

    Tejedor, Maria; Martín-Santiago, Ana; Gómez, Cristina; Fiol, Miquel; Benítez-Segura, Ignacio

    2010-01-01

    Congenital plaque-type glomuvenous malformation (GVM) is caused by loss of function mutations in glomulin gene. We report a newborn with this rare vascular disorder associated with chylous ascites. The common mesenchymal origin of GVM and lymphatic vessels as well as the glomulin expression in vascular smooth muscle cells in utero could help explain this unusual prenatal complication of glomuvenous malformations.

  12. Development of Tc-99m Imaging Agents for Abeta Plaques

    SciTech Connect

    Zhi-Ping, Zhuang; Mei-Ping Kung; Catherihne Hou; Hank F. Kung

    2008-09-26

    Development of SPECT imaging agents based on Tc-99m targeting Aβ plaques is useful for diagnosis of Alzheimer’s disease (AD). A stilbene derivative, [11C]SB-13, showing promise in detecting senile plaques present in AD patients has been reported previously1,2. Based on the 4’-amino-stilbene core structure we have added substituted groups through which a chelating group, N2S2, was conjugated. We report herein a series of Tc-99m labeled stilbene derivative conjugated with a TcO[N2S2] core. The syntheses of stilbenes containing a N2S2 chelating ligand are achieved by a scheme shown. Lipophilic 99mTc stilbene complexes were successfully prepared and purified through HPLC. Preliminary results of in vitro labeling of brain sections from transgenic mice showed very promising plaque labeling. These 99mTc stilbene derivatives are warranted for further evaluations as potential imaging agents targeting amyloid plaques.

  13. APOLLO 16 TECHNICIAN ATTACHES PLAQUE TO LUNAR MODULE'S DESCENT STAGE

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Working inside the Apollo 16 Saturn V space vehicle at the launch pad, technician Ken Crow attaches a stainless steel plaque bearing the names of Apollo 16 astronauts John W. Young, Thomas K. Mattingly II and Charles M. Duke, Jr., to the Lunar Module's descent stage, which will remain on the Moon's surface.

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

    PubMed

    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.

  15. Ichthyosiform large plaque parapsoriasis: report of a rare entity.

    PubMed

    Nag, Falguni; Ghosh, Arghyaprasun; Biswas, Projna; Chatterjee, Gobinda; Biswas, Saugato

    2013-09-01

    Large plaque parapsoriasis (LPP) is an idiopathic, chronic scaly dermatosis classified within parapsoriasis group of diseases, occurring commonly in middle aged patients of all races and geographic regions. LPP and its variants are closely related to the patch stage of mycosis fungoides. The two types of LPP mostly described are the poikilodermatous and retiform parapsoriasis. We are reporting an ichthyosiform LPP for its rarity.

  16. Reporting Casting Bronze Plaque Becomes Advisers Class Project

    ERIC Educational Resources Information Center

    Ross, Charlie

    1977-01-01

    Describes an advisers' class project (at the University of Oklahoma) which consisted of reporting on the casting of a bronze plaque bearing the names of the first school newspaper, "The Students Gazette," and its editor, Samuel M. Fox, for presentation in Philadelphia to commemorate scholastic journalism's Bicentennial. (MB)

  17. Interstellar Message Plaques: Application of White-Light Holography

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    2002-01-01

    During Spring / Summer 2001, a prototype white-light holographic interstellar-probe message plaque was created under Contract H-29712D of NASA Marshall Spaceflight Center (MSFC), and commercial white-light holograms were tested for space-radiation tolerance at the MSFC Space Environment Facility (SEF) in Huntsville, AL, USA. Artist C Bangs' message plaque was created at the Center for Holographic Arts in Long Island City, NY. The 57.5 X 47.5 cm rainbow hologram was delivered to MSFC after framing by Simon Liu Inc., Brooklyn, NY, USA. The prototype message plaque, which is in the collection of the MSFC Space Transportation Directorate, has six multiplexed 2-D and 3-D images representing humans, the hypothetical interstellar spacecraft, and our position in the galaxy. Consultation with John Caulfield of Fisk University, an expert in holography, revealed that micron-thick holograms not much larger than a sheet of paper could contain hundreds of thousands of images, which opens the me ssage-plaque field considerably so that work of many artists could be included. Tests of commercial holograms at up to 100 MRad of simulated solar-wind radiation were performed at MSFC / SEF. Image-quality deterioriation was monitored using the image-color- histogram of the (trademarked) Adobe Photoshop software package. No significant deterioration occurred, which is in agreement with the literature. Holographic solar sails may be a propulsive application of this technology.

  18. 4. VISTA POINT AND INTERPRETIVE PLAQUE AT LEE VINING CANYON. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VISTA POINT AND INTERPRETIVE PLAQUE AT LEE VINING CANYON. NOTE ROAD CUT ON CANYON WALL. LOOKING NNE. GIS: N-37 56 30.3 / 119 13 44.8 - Tioga Road, Between Crane Flat & Tioga Pass, Yosemite Village, Mariposa County, CA

  19. DETAIL VIEW OF GENERAL ELECTRIC PLAQUE INSIDE NORTHWEST CONTROL HOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF GENERAL ELECTRIC PLAQUE INSIDE NORTHWEST CONTROL HOUSE SHOWING MANUFACTURING SPECIFICATIONS AND SWASTICA IN LOWER RIGHT CORNER - Ortona Lock, Lock No. 2, Machinery and Control Houses, Caloosahatchee River, Cross-State Canal, Okeechobee Intracoastal Waterway, Ortona, Glades County, FL

  20. Microflora and chemical composition of dental plaque from subjects with hereditary fructose intolerance.

    PubMed

    Hoover, C I; Newbrun, E; Mettraux, G; Graf, H

    1980-06-01

    We compared the microbiological and chemical composition of dental plaque from subjects with hereditary fructose intolerance who restrict their dietary sugar intake with that of control subjects who do not. The two groups showed no significant differences in chemical composition of plaque: the mean protein, carbohydrate, calcium, magnesium, and phosphate contents were similar. Dental plaque from both groups contained similar numbers of total colony-forming units per microgram of plaque protein, and Streptococcus sanguis, an indigenous nonpathogen, was isolated with equal frequency from plaque samples of both groups. However, potentially odontopathic Streptococcus mutans and Lactobacillus were isolated three to four times more frequently from plaque samples of control subjects than from plaque samples of subjects with hereditary fructose intolerance. Clearly, diet (sucrose in particular) influences the colonization and multiplication of specific cariogenic organisms in dental plaque.

  1. Dosimetry of (125)I and (103)Pd COMS eye plaques for intraocular tumors: report of Task Group 129 by the AAPM and ABS.

    PubMed

    Chiu-Tsao, Sou-Tung; Astrahan, Melvin A; Finger, Paul T; Followill, David S; Meigooni, Ali S; Melhus, Christopher S; Mourtada, Firas; Napolitano, Mary E; Nath, Ravinder; Rivard, Mark J; Rogers, D W O; Thomson, Rowan M

    2012-10-01

    Dosimetry of eye plaques for ocular tumors presents unique challenges in brachytherapy. The challenges in accurate dosimetry are in part related to the steep dose gradient in the tumor and critical structures that are within millimeters of radioactive sources. In most clinical applications, calculations of dose distributions around eye plaques assume a homogenous water medium and full scatter conditions. Recent Monte Carlo (MC)-based eye-plaque dosimetry simulations have demonstrated that the perturbation effects of heterogeneous materials in eye plaques, including the gold-alloy backing and Silastic insert, can be calculated with reasonable accuracy. Even additional levels of complexity introduced through the use of gold foil "seed-guides" and custom-designed plaques can be calculated accurately using modern MC techniques. Simulations accounting for the aforementioned complexities indicate dose discrepancies exceeding a factor of ten to selected critical structures compared to conventional dose calculations. Task Group 129 was formed to review the literature; re-examine the current dosimetry calculation formalism; and make recommendations for eye-plaque dosimetry, including evaluation of brachytherapy source dosimetry parameters and heterogeneity correction factors. A literature review identified modern assessments of dose calculations for Collaborative Ocular Melanoma Study (COMS) design plaques, including MC analyses and an intercomparison of treatment planning systems (TPS) detailing differences between homogeneous and heterogeneous plaque calculations using the American Association of Physicists in Medicine (AAPM) TG-43U1 brachytherapy dosimetry formalism and MC techniques. This review identified that a commonly used prescription dose of 85 Gy at 5 mm depth in homogeneous medium delivers about 75 Gy and 69 Gy at the same 5 mm depth for specific (125)I and (103)Pd sources, respectively, when accounting for COMS plaque heterogeneities. Thus, the adoption of

  2. MID-ATLANTIC REGIONAL VULNERABILITY ASSESSMENT

    EPA Science Inventory

    ORD's Regional Vulnerability Assessment (REVA) Program is developing and demonstrating approaches to assess current and future environmental vulnerabilities so that risk management activities can be targeted. The sister program to EMA.P (Environmental Monitoring Assessment Progr...

  3. Infrastructure Vulnerability Assessment Model (I-VAM).

    PubMed

    Ezell, Barry Charles

    2007-06-01

    Quantifying vulnerability to critical infrastructure has not been adequately addressed in the literature. Thus, the purpose of this article is to present a model that quantifies vulnerability. Vulnerability is defined as a measure of system susceptibility to threat scenarios. This article asserts that vulnerability is a condition of the system and it can be quantified using the Infrastructure Vulnerability Assessment Model (I-VAM). The model is presented and then applied to a medium-sized clean water system. The model requires subject matter experts (SMEs) to establish value functions and weights, and to assess protection measures of the system. Simulation is used to account for uncertainty in measurement, aggregate expert assessment, and to yield a vulnerability (Omega) density function. Results demonstrate that I-VAM is useful to decisionmakers who prefer quantification to qualitative treatment of vulnerability. I-VAM can be used to quantify vulnerability to other infrastructures, supervisory control and data acquisition systems (SCADA), and distributed control systems (DCS).

  4. Accurate Evaluation of Quantum Integrals

    NASA Technical Reports Server (NTRS)

    Galant, D. C.; Goorvitch, D.; Witteborn, Fred C. (Technical Monitor)

    1995-01-01

    Combining an appropriate finite difference method with Richardson's extrapolation results in a simple, highly accurate numerical method for solving a Schrodinger's equation. Important results are that error estimates are provided, and that one can extrapolate expectation values rather than the wavefunctions to obtain highly accurate expectation values. We discuss the eigenvalues, the error growth in repeated Richardson's extrapolation, and show that the expectation values calculated on a crude mesh can be extrapolated to obtain expectation values of high accuracy.

  5. Dose verification of eye plaque brachytherapy using spectroscopic dosimetry.

    PubMed

    Jarema, T; Cutajar, D; Weaver, M; Petasecca, M; Lerch, M; Kejda, A; Rosenfeld, A

    2016-09-01

    Eye plaque brachytherapy has been developed and refined for the last 80 years, demonstrating effective results in the treatment of ocular malignancies. Current dosimetry techniques for eye plaque brachytherapy (such as TLD- and film-based techniques) are time consuming and cannot be used prior to treatment in a sterile environment. The measurement of the expected dose distribution within the eye, prior to insertion within the clinical setting, would be advantageous, as any errors in source loading will lead to an erroneous dose distribution and inferior treatment outcomes. This study investigated the use of spectroscopic dosimetry techniques for real-time quality assurance of I-125 based eye plaques, immediately prior to insertion. A silicon detector based probe, operating in spectroscopy mode was constructed, containing a small (1 mm(3)) silicon detector, mounted within a ceramic holder, all encapsulated within a rubber sheath to prevent water infiltration of the electronics. Preliminary tests of the prototype demonstrated that the depth dose distribution through the central axis of an I-125 based eye plaque may be determined from AAPM Task Group 43 recommendations to a deviation of 6 % at 3 mm depth, 7 % at 5 mm depth, 1 % at 10 mm depth and 13 % at 20 mm depth, with the deviations attributed to the construction of the probe. A new probe design aims to reduce these discrepancies, however the concept of spectroscopic dosimetry shows great promise for use in eye plaque quality assurance in the clinical setting.

  6. Soil vulnerability for cesium transfer.

    PubMed

    Vandenhove, Hildegarde; Sweeck, Lieve

    2011-07-01

    The recent events at the Fukushima Daiichi nuclear power plant in Japan have raised questions about the accumulation of radionuclides in soils and the possible impacts on agriculture surrounding nuclear power plants. This article summarizes the knowledge gained after the nuclear power plant accident in Chernobyl, Ukraine, on how soil parameters influence soil vulnerability for radiocesium bioavailability, discusses some potential agrochemical countermeasures, and presents some predictions of radiocesium crop concentrations for areas affected by the Fukushima accident.

  7. Vulnerabilities

    DTIC Science & Technology

    2009-05-04

    May 1, 2006)”, http://www.mod.go.jp/e/d_policy/dp13.html (accessed 1 April 2009). 6 ibid 7 Hongo , Jun. “Japan, U.S. sign accord on forces,” The...Jacobs, G. Keith. "Guam Becoming US Pacific Linchpin." Asia-Pacific Defence Reporter 29 (2003): 38-39. Jun, Hongo . "Japan, U.S. sign accord on forces

  8. Cotton genetic resources and crop vulnerability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A report on the genetic vulnerability of cotton was provided to the National Genetic Resources Advisory Council. The report discussed crop vulnerabilities associated with emerging diseases, emerging pests, and a narrowing genetic base. To address these crop vulnerabilities, the report discussed the ...

  9. Vulnerability of older patients in critical care.

    PubMed

    Hardin, Sonya R

    2015-06-01

    One of the patient characteristics in the AACN Synergy Model is vulnerability. Vulnerability is defined in the model as the susceptibility to actual or potential stressors that may adversely affect patients' outcomes. The risk of vulnerability increases in older patients in critical care units.

  10. Plaque: What It Is and How to Get Rid of It

    MedlinePlus

    Rx for PLAQUE: Sound Teeth What it is and how to get rid of it People used to think that as you got older you naturally lost your teeth. ... your teeth for a lifetime! Plaque: What is it? Plaque is made up of invisible masses of ...

  11. 21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... adhesion of dental plaque. (a) Identification. The device is assigned the generic name oral rinse to reduce... bacterial plaque on teeth and oral mucosal surfaces by physical means. The device type includes those devices that act by reducing the attachment and inhibiting the growth of bacterial plaque....

  12. Stable size distribution of amyloid plaques over the course of Alzheimer disease.

    PubMed

    Serrano-Pozo, Alberto; Mielke, Matthew L; Muzitansky, Alona; Gómez-Isla, Teresa; Growdon, John H; Bacskai, Brian J; Betensky, Rebecca A; Frosch, Matthew P; Hyman, Bradley T

    2012-08-01

    Amyloid β plaques are a key pathologic feature of Alzheimer disease (AD), but whether plaque sizes increase or stabilize over the course of AD is unknown. We measured the size distribution of total immunoreactive (10D5-positive) and dense-core (Thioflavin S-positive) plaques in the temporal neocortex of a large group of subjects with AD and age-matched plaque-bearing subjects without dementia to test the hypothesis that amyloid plaques continue to grow along with the progression of the disease. The size of amyloid β (10D5)-positive plaques did not differ between groups, whereas dense-core plaques from the group with AD were slightly larger than those from the group without dementia (∼25%-30%, p = 0.01). Within the group with AD, dense-core plaque size did not independently correlate with duration of clinical disease (from 4 to 21 years, p = 0.68), whereas 10D5-positive plaque size correlated negatively with disease duration (p = 0.01). By contrast, an earlier age of symptom onset strongly predicted a larger postmortem plaque size; this effect was independent of disease duration and the presence of the APOE[Latin Small Letter Open E]4 allele (p = 0.0001). We conclude that plaques vary in size among patients, with larger size distributions correlating with an earlier age of onset, but plaques do not substantially increase in size over the clinical course of the disease.

  13. Local Inhibition of Macrophage and Smooth Muscle Cell Proliferation to Suppress Plaque Progression

    PubMed Central

    Sukhovershin, Roman A.; Toledano Furman, Naama E.; Tasciotti, Ennio; Trachtenberg, Barry H.

    2016-01-01

    Atherosclerosis is a complex process responsible for a major burden of cardiovascular morbidity and mortality. Macrophages and smooth muscle cells (SMCs) are abundant within atherosclerotic plaques. This review discusses the role of macrophages and SMCs in plaque progression and provides an overview of nanoparticle-based approaches and other current methods for local targeting of atherosclerotic plaques. PMID:27826367

  14. Atorvastatin attenuates p-cresyl sulfate-induced atherogenesis and plaque instability in ApoE knockout mice

    PubMed Central

    Han, Hui; Chen, Yanjia; Zhu, Jinzhou; Ni, Jingwei; Sun, Jiateng; Zhang, Ruiyan

    2016-01-01

    p-cresyl sulfate (PCS) is a protein-bound uremic toxin retained in the blood of patients with chronic kidney disease (CKD) As atherosclerosis is a primary cardiovascular complication for patients with CKD, the aim of the present study was to investigate the mechanisms underlying the aggravation of atherosclerosis by PCS. In addition, the effect of atorvastatin was assessed in reversing the effects of PCS. PCS was revealed to promote the initiation and progression of atherosclerosis. Following treatment with atorvastatin, apolipoprotein E knockout mice demonstrated a reduction in PCS-induced atherogenesis and plaque vulnerability. In addition, atorvastatin decreased the protein expression levels of vascular cell adhesion molecule-1 and intercellular cell adhesion molecule-1, and the interaction between leukocytes and endothelia. The plasma lipid profiles of mice were not significantly affected by gavage of low-dose atorvastatin. The results of the present study indicate that PCS promotes plaque growth and instability by enhancing leukocyte-endothelium interaction, and that these effects may be attenuated by atorvastatin treatment. PMID:27574007

  15. Health status of vulnerable populations.

    PubMed

    Aday, L A

    1994-01-01

    The notion of risk underlying the concept of vulnerability implies that everyone is potentially vulnerable (or at risk), that is, there is always a chance of developing health problems. The risk is, however, greater for those with the least social status, social capital, and human capital resources to either prevent or ameliorate the origins and consequences of poor physical, psychological, or social health. The completeness and accuracy of information on the health status of the vulnerable populations examined here varies substantially across groups. Methodological work is needed to derive standardized definitions of terms, specify the content and timing for collecting information for minimum basic data sets, and develop uniform standards for evaluating and reporting data quality on the health status of vulnerable populations. The variety of indicators of vulnerable populations examined indicates that during the decade of the 1980s the incidence of serious physical, psychological, and/or social needs increased (at worst) and was unameliorated (at best) for millions of Americans. AIDS emerged as a new and deadly threat from a handful of cases classified as Gay-Related Immune Deficiency in the early part of the 1980s to what now may be over a million Americans who are HIV-positive. The number of homeless has increased an average of 20% a year to estimates now ranging up to one million men, women, or children homeless on any given night to twice that number who may be homeless sometime during the year. Over seven million people immigrated to the United States during the period from 1981 to 1990--an increasing proportion of whom are refugees carrying with them the physical, psychological, and social wounds of war. The number of children abused by family members or other intimates has burgeoned to an estimated 1.6 to 1.7 million per year, and with the greater use of firearms, intentional acts of violence towards oneself or others are becoming increasingly deadly in

  16. Measuring vulnerability to disaster displacement

    NASA Astrophysics Data System (ADS)

    Brink, Susan A.; Khazai, Bijan; Power, Christopher; Wenzel, Friedemann

    2015-04-01

    Large scale disasters can cause devastating impacts in terms of population displacement. Between 2008 and 2013, on average 27 million people were displaced annually by disasters (Yonetani 2014). After large events such as hurricane Katrina or the Port-au-Prince earthquake, images of inadequate public shelter and concerns about large scale and often inequitable migration have been broadcast around the world. Population displacement can often be one of the most devastating and visible impacts of a natural disaster. Despite the importance of population displacement in disaster events, measures to understand the socio-economic vulnerability of a community often use broad metrics to estimate the total socio-economic risk of an event rather than focusing on the specific impacts that a community faces in a disaster. Population displacement is complex and multi-causal with the physical impact of a disaster interacting with vulnerability arising from the response, environmental issues (e.g., weather), cultural concerns (e.g., expectations of adequate shelter), and many individual factors (e.g., mobility, risk perception). In addition to the complexity of the causes, population displacement is difficult to measure because of the wide variety of different terms and definitions and its multi-dimensional nature. When we speak of severe population displacement, we may refer to a large number of displaced people, an extended length of displacement or associated difficulties such as poor shelter quality, risk of violence and crime in shelter communities, discrimination in aid, a lack of access to employment or other difficulties that can be associated with large scale population displacement. We have completed a thorough review of the literature on disaster population displacement. Research has been conducted on historic events to understand the types of negative impacts associated with population displacement and also the vulnerability of different groups to these impacts. We

  17. Research on security vulnerability of chip

    NASA Astrophysics Data System (ADS)

    Chen, Zhifeng; Li, Qingbao; Li, Zhou

    2013-03-01

    The 21st century is the information era. IC (Integrated Circuit) is the basis of the modern information industry. The security vulnerability or back door of IC is directly related to the entire information system security. From the perspective of information security, security vulnerability of chip is led out through the practical examples and then the importance of security vulnerability of chip is emphasized. By comparing the security vulnerability of chip with the software virus, the characteristics of the chip vulnerabilities are summed up. Moreover, this paper describes the security vulnerability models of different control logic chips, combinational and sequential logic chips models. Finally it puts forward two kinds of detecting methods of security vulnerability of chip against the two models.

  18. A free boundary problem for steady small plaques in the artery and their stability

    NASA Astrophysics Data System (ADS)

    Friedman, Avner; Hao, Wenrui; Hu, Bei

    2015-08-01

    Atherosclerosis is a leading cause of death in the United States and worldwide; it originates from a plaque which builds up in the artery. In this paper, we consider a simplified model of plaque growth involving LDL and HDL cholesterols, macrophages and foam cells, which satisfy a coupled system of PDEs with a free boundary, the interface between the plaque and the blood flow. We prove that there exist small radially symmetric stationary plaques and establish a sharp condition that ensures their stability. We also determine necessary and sufficient conditions under which a small initial plaque will shrink and disappear, or persist for all times.

  19. Urban flood risk mitigation: from vulnerability assessment to resilient city

    NASA Astrophysics Data System (ADS)

    Serre, D.; Barroca, B.

    2009-04-01

    some research activities have been undertaken, there are no specific methods and tools to assess flood vulnerability at the scale of the city. Indeed, by studying literature we can list some vulnerability indicators and a few Geographic Information System (GIS) tools. But generally indicators and GIS are not developed specifically at the city scale: often a regional scale is used. Analyzing vulnerability at this scale needs more accurate and formalized indicators and GIS tools. The second limit of existing GIS is temporal: even if vulnerability could be assessed and localized through GIS, such tools cannot assist city managers in their decision to efficiency recover after a severe flood event. Due to scale and temporal limits, methods and tools available to assess urban vulnerability need large improvements. Talking into account all these considerations and limits, our research is focusing on: • vulnerability indicators design; • recovery scenarios design; • GIS for city vulnerability assessment and recovery scenarios. Dealing with vulnerability indicators, the goal is to design a set of indicators of city sub systems. Sub systems are seen like assets of high value and complex and interdependent infrastructure networks (i.e. power supplies, communications, water, transport etc.). The infrastructure networks are critical for the continuity of economic activities as well as for the people's basic living needs. Their availability is also required for fast and effective recovery after flood disasters. The severity of flood damage therefore largely depends on the degree that both high value assets and critical urban infrastructure are affected, either directly or indirectly. To face the challenge of designing indicators, a functional model of the city system (and sub systems) has to be built to analyze the system response to flood solicitation. Then, a coherent and an efficient set of vulnerability of indicators could be built up. With such methods city stakeholders

  20. Apollo 11 Commander Armstrong Presents President With Commemorative Plaque

    NASA Technical Reports Server (NTRS)

    1974-01-01

    On June 4, 1974, 5 years after the successful Apollo 11 lunar landing mission, commander Neil Armstrong (right) presented a plaque to U.S. President Richard Milhous Nixon (left) on behalf of all people who had taken part in the space program. In making the presentation, Armstrong said 'Mr. President, you have proclaimed this week to be United States Space week in conjunction with the fifth anniversary of our first successful landing on the Moon. It is my privilege to represent my colleagues, the crewmen of projects Mercury, Gemini, Apollo, and Skylab, and the men and women of NASA, and the hundreds of thousands of Americans from across the land who contributed so mightily to the success of our efforts in space in presenting this plaque which bears the names of each individual who has had the privilege of representing this country' in a space flight. The presentation was made at the California white house in San Clemente.

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

    PubMed Central

    Kalanuria, Atul Ashok; Nyquist, Paul; Ling, Geoffrey

    2012-01-01

    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. PMID:23049260

  2. Multiple keratoacanthomas developing in healing plaques of Psoriasis

    PubMed Central

    Relhan, Vineet; Sinha, Surabhi; Khurana, Nita; Garg, Vijay K.

    2013-01-01

    A 22 year old male psoriatic patient presented with multiple reddish scaly plaques all over body. After hematological and biochemical investigations the patient was started on oral methotrexate 15 mg weekly. PASI score at the start of treatment was 26.2. After 3 months PASI dropped to 11.5, the dose of methotrexate was tapered to 7.5mg weekly and the patient was maintained on this dose and kept under monthly follow up. Four months later, the patient presented with reddish to hyperpigmented raised firm nodules having a central crater over the healing plaques of psoriasis. Few lesions showed self resolution over a period of 6-12 weeks. Histopathology of the lesion confirmed it to be Keratoacanthoma. We believe the most likely etiologic factors for the multiple KAs in our patient could be a genetic susceptibility stimulated by multiple causes. PMID:23984234

  3. Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation.

    PubMed

    Zimmermann, Leonard W; Amoush, Ahmad; Wilkinson, Douglas A

    2015-11-08

    This work is a comparative study of the dosimetry calculated by Plaque Simulator, a treatment planning system for eye plaque brachytherapy, to the dosimetry calculated using Monte Carlo simulation 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. In addition, the dosimetry parameters Λ, gL(r), and F(r,θ) were calculated for the IsoAid Advantage model IAI-125 (125)I seed and benchmarked against published data. Bebig Plaque Simulator (PS) v5.74 was used to calculate the central axis dose based on the AAPM Updated Task Group 43 (TG-43U1) dose formalism. The calculated central axis dose from MC and PS was then compared. When the MC dosimetry parameters for the IsoAid Advantage (125)I seed were compared with the consensus values, Λ agreed with the consensus value to within 2.3%. However, much larger differences were found between MC calculated gL(r) and F(r,θ) and the consensus values. The differences between MC-calculated dosimetry parameters are much smaller when compared with recently published data. The differences between the calculated central axis absolute dose from MC and PS ranged from 5% to 10% for distances between 1 and 12 mm from the outer scleral surface. When the dosimetry parameters for the (125)I seed from this study were used in PS, the calculated absolute central axis dose differences were reduced by 2.3% from depths of 4 to 12 mm from the outer scleral surface. We conclude that PS adequately models the central dose profile of this plaque using its defaults for the IsoAid model IAI-125 at distances of 1 to 7 mm from the outer scleral surface. However, improved dose accuracy can be obtained by using updated dosimetry parameters for the IsoAid model IAI-125 (125)I seed.

  4. Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation.

    PubMed

    Zimmermann, Leonard W; Amoush, Ahmad; Wilkinson, Douglas A

    2015-11-01

    This work is a comparative study of the dosimetry calculated by Plaque Simulator, a treatment planning system for eye plaque brachytherapy, to the dosimetry calculated using Monte Carlo simulation 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  125I seeds. In addition, the dosimetry parameters Λ, gL(r), and F(r,θ) were calculated for the IsoAid Advantage model IAI-125  125I seed and benchmarked against published data. Bebig Plaque Simulator (PS) v5.74 was used to calculate the central axis dose based on the AAPM Updated Task Group 43 (TG-43U1) dose formalism. The calculated central axis dose from MC and PS was then compared. When the MC dosimetry parameters for the IsoAid Advantage  125I seed were compared with the consensus values, Λ agreed with the consensus value to within 2.3%. However, much larger differences were found between MC calculated gL(r) and F(r,θ) and the consensus values. The differences between MC-calculated dosimetry parameters are much smaller when compared with recently published data. The differences between the calculated central axis absolute dose from MC and PS ranged from 5% to 10% for distances between 1 and 12 mm from the outer scleral surface. When the dosimetry parameters for the  125I seed from this study were used in PS, the calculated absolute central axis dose differences were reduced by 2.3% from depths of 4 to 12 mm from the outer scleral surface. We conclude that PS adequately models the central dose profile of this plaque using its defaults for the IsoAid model IAI-125 at distances of 1 to 7 mm from the outer scleral surface. However, improved dose accuracy can be obtained by using updated dosimetry parameters for the IsoAid model IAI-125  125I seed. PACS number: 87.55.K.

  5. Hydrocortisone supresses inflammatory activity of metalloproteinase - 8 in carotid plaque

    PubMed Central

    Gabriel, Sthefano Atique; Antonangelo, Leila; Capelozzi, Vera Luiza; Beteli, Camila Baumann; de Camargo Júnior, Otacílio; de Aquino, José Luis Braga; Caffaro, Roberto Augusto

    2015-01-01

    Objective Matrix metalloproteinases are inflammatory biomarkers involved in carotid plaque instability. Our objective was to analyze the inflammatory activity of plasma and carotid plaque MMP-8 and MMP-9 after intravenous administration of hydrocortisone. Methods The study included 22 patients with stenosis ≥ 70% in the carotid artery (11 symptomatic and 11 asymptomatic) who underwent carotid endarterectomy. The patients were divided into two groups: Control Group - hydrocortisone was not administered, and Group 1 - 500 mg intravenous hydrocortisone was administered during anesthetic induction. Plasma levels of MMP-8 and MMP-9 were measured preoperatively (24 hours before carotid endarterectomy) and at 1 hour, 6 hours and 24 hours after carotid endarterectomy. In carotid plaque, tissue levels of MMP-8 and MMP-9 were measured. Results Group 1 showed increased serum levels of MMP- 8 (994.28 pg/ml and 408.54 pg/ml, respectively; P=0.045) and MMP-9 (106,656.34 and 42,807.69 respectively; P=0.014) at 1 hour after carotid endarterectomy compared to the control group. Symptomatic patients in Group 1 exhibited lower tissue concentration of MMP-8 in comparison to the control group (143.89 pg/ml and 1317.36 respectively; P=0.003). There was a correlation between preoperative MMP-9 levels and tissue concentrations of MMP-8 (P=0.042) and MMP-9 (P=0.019) between symptomatic patients in the control group. Conclusion Hydrocortisone reduces the concentration of MMP- 8 in carotid plaque, especially in symptomatic patients. There was an association between systemic and tissue inflammation. PMID:26313719

  6. The Dental Plaque Microbiome in Health and Disease

    PubMed Central

    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. PMID:23520516

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

    NASA Astrophysics Data System (ADS)

    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 (p<0.05) of collagen type I distal to the bifurcation compared to proximal tissue in the carotid specimens. Conclusion: Fluorescence

  8. An Osteolytic Meningioma en Plaque of the Sphenoid Ridge

    PubMed Central

    Baek, Jin-Uk; Yoo, Jae-Chul

    2008-01-01

    Meningioma en plaque (MEP) is a rare tumor characterized more by its clinical and biological behavior than its histological appearance. Hyperostosis of the skull is one of the characteristic signs of MEP. This bony change can produce clinical symptoms and signs in MEP by pressing against adjacent structures. The authors report a rare case of an osteolytic MEP extending from the sphenoid wing into the orbital wall, middle fossa, and temporalis muscle. PMID:19096543

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

    PubMed

    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.

  10. Vulnerability of groundwater resources to nitrate pollution: A simple and effective procedure for delimiting Nitrate Vulnerable Zones.

    PubMed

    Arauzo, Mercedes

    2017-01-01

    This research was undertaken to further our understanding of the factors involved in nonpoint-source nitrate pollution of groundwater. The shortcomings of some of the most commonly used methods for assessing groundwater vulnerability have been analysed and a new procedure that incorporates key improvements has been proposed. The new approach (LU-IV procedure) allows us to assess and map groundwater vulnerability to nitrate pollution and to accurately delimit the Nitrate Vulnerable Zones. The LU-IV procedure proved more accurate than the most widely used methods to assess groundwater vulnerability (DRASTIC, GOD), when compared with nitrate distribution in the groundwater of 46 aquifers included in the study (using the drainage basin as the unit of analysis). The proposed procedure stands out by meeting the following requirements: (1) it uses readily available parameters that provide enough data to feed the model, (2) it excludes redundant parameters, (3) it avoids the need to assign insufficiently contrasted weights to parameters, (4) it assess the whole catchment area that potentially drains N-polluted waters into the receptor aquifer, (5) it can be implemented within a GIS, and (6) it provides a multi-scale representation. As the LU-IV procedure has been demonstrated to be a reliable tool for delimiting NVZ, it could be particularly interesting to use it in countries where certain types of environmental data are either not available or have only limited availability. Based on this study (and according to the LU-IV procedure), it was concluded that an area of at least 1728km(2) should be considered as NVZ. This sharply contrasts with the current 328km(2) officially designated in the study area by the Spain's regional administrations. These results highlight the need to redefine the current NVZ designation, which is essential for an appropriate implementation of action programmes designed to restore water quality in line with Directive 91/676/EEC.

  11. Inadequate dietary magnesium intake increases atherosclerotic plaque development in rabbits

    PubMed Central

    King, Jennifer L.; Miller, Rita J.; Blue, James P.; O'Brien, William D.; Erdman, John W.

    2012-01-01

    Epidemiological studies have shown dietary magnesium (Mg) intake and serum Mg levels to be inversely correlated with the development of atherosclerosis. We hypothesized that low levels of Mg would promote atherosclerotic plaque development in rabbits. New Zealand white rabbits (4 months old, n = 22) were fed an atherogenic diet containing 0.12% (−Mg), 0.27% (control), or 0.43% (+Mg) Mg for 8 weeks. Blood samples were obtained at baseline, 2, 4, 6, and 8 weeks and were assayed for total cholesterol, high-density lipoprotein (HDL), non-HDL, triglycerides (TG), C-reactive protein, serum Mg, and erythrocyte Mg. Aortas from −Mg had significantly more plaque, with an intima thickness 42% greater than control and 36% greater than +Mg. Serum cholesterol levels rose over time, and at 8 weeks, −Mg had the highest and +Mg the lowest total and non-HDL cholesterol and TG levels, although these results did not reach significance. Over time, serum Mg levels increased, and erythrocyte Mg levels decreased. C-reactive protein significantly increased in all groups at 4 and 6 weeks but returned to baseline levels by 8 weeks. This study supports the hypothesis that inadequate intake of Mg results in an increase in atherosclerotic plaque development in rabbits. PMID:19555816

  12. HDL-Mimetic PLGA Nanoparticle To Target Atherosclerosis Plaque Macrophages

    PubMed Central

    Sanchez-Gaytan, Brenda L.; Fay, Francois; Lobatto, Mark E.; Tang, Jun; Ouimet, Mireille; Kim, YongTae; van der Staay, Susanne E. M.; van Rijs, Sarian M.; Priem, Bram; Zhang, Liangfang; Fisher, Edward A; Moore, Kathryn J.; Langer, Robert; Fayad, Zahi A.; Mulder, Willem J M

    2015-01-01

    High-density lipoprotein (HDL) is a natural nanoparticle that exhibits an intrinsic affinity for atherosclerotic plaque macrophages. Its natural targeting capability as well as the option to incorporate lipophilic payloads, e.g., imaging or therapeutic components, in both the hydrophobic core and the phospholipid corona make the HDL platform an attractive nanocarrier. To realize controlled release properties, we developed a hybrid polymer/HDL nanoparticle composed of a lipid/apolipoprotein coating that encapsulates a poly(lactic-co-glycolic acid) (PLGA) core. This novel HDL-like nanoparticle (PLGA–HDL) displayed natural HDL characteristics, including preferential uptake by macrophages and a good cholesterol efflux capacity, combined with a typical PLGA nanoparticle slow release profile. In vivo studies carried out with an ApoE knockout mouse model of atherosclerosis showed clear accumulation of PLGA–HDL nanoparticles in atherosclerotic plaques, which colocalized with plaque macrophages. This biomimetic platform integrates the targeting capacity of HDL biomimetic nanoparticles with the characteristic versatility of PLGA-based nanocarriers. PMID:25650634

  13. HDL-mimetic PLGA nanoparticle to target atherosclerosis plaque macrophages.

    PubMed

    Sanchez-Gaytan, Brenda L; Fay, Francois; Lobatto, Mark E; Tang, Jun; Ouimet, Mireille; Kim, YongTae; van der Staay, Susanne E M; van Rijs, Sarian M; Priem, Bram; Zhang, Liangfang; Fisher, Edward A; Moore, Kathryn J; Langer, Robert; Fayad, Zahi A; Mulder, Willem J M

    2015-03-18

    High-density lipoprotein (HDL) is a natural nanoparticle that exhibits an intrinsic affinity for atherosclerotic plaque macrophages. Its natural targeting capability as well as the option to incorporate lipophilic payloads, e.g., imaging or therapeutic components, in both the hydrophobic core and the phospholipid corona make the HDL platform an attractive nanocarrier. To realize controlled release properties, we developed a hybrid polymer/HDL nanoparticle composed of a lipid/apolipoprotein coating that encapsulates a poly(lactic-co-glycolic acid) (PLGA) core. This novel HDL-like nanoparticle (PLGA-HDL) displayed natural HDL characteristics, including preferential uptake by macrophages and a good cholesterol efflux capacity, combined with a typical PLGA nanoparticle slow release profile. In vivo studies carried out with an ApoE knockout mouse model of atherosclerosis showed clear accumulation of PLGA-HDL nanoparticles in atherosclerotic plaques, which colocalized with plaque macrophages. This biomimetic platform integrates the targeting capacity of HDL biomimetic nanoparticles with the characteristic versatility of PLGA-based nanocarriers.

  14. The effect of two toothpastes on plaque and gingival inflamation.

    PubMed

    Saxer, U P; Menghini, G; Bohnert, K J; Ley, F

    1995-01-01

    In this study on 60 adult subjects, the effective of Parodontax, a dentifrice containing herbal ingredients and sodium bicarbonate abrasive, was compared to a non-marketed new toothpaste containing herbal ingredients and calcium hydrogen phosphate as the abrasive. Plaque, gingivitis and gingival bleeding parameters were scored. The periodontal probe bleeding index of Ainamo and Bay was modified to score slight and moderate bleeding. In this first four-week period all subjects used the new toothpaste. After this period the new toothpaste produced a significant decrease (p<0.01) in gingivitis and bleeding on probing, but no effect on plaque was observed. During the second period of eight weeks the subjects were randomly divided into two groups, one using Parodontax and the other group continuing with the new toothpaste. The study design was a double-blind procedure. At the end of the 12-week study period the plaque index showed no changes in both groups. The gingivitis and bleeding indices decreased significantly (p<0.001) by 40% in both groups compared to the baseline examination.

  15. Isolation of Actinomyces bacteriophage from human dental plaque.

    PubMed

    Tylenda, C A; Calvert, C; Kolenbrander, P E; Tylenda, A

    1985-07-01

    Human dental plaque samples were screened for the presence of bacteriophage for Actinomyces viscosus and Streptococcus sanguis. None of the 336 samples yielded phage for S. sanguis, but 10 contained virulent actinomyces phage. A high host cell specificity was observed in that one phage isolate infected only A. viscosus T14V, eight phage isolates infected only A. viscosus MG-1, and one infected both strains. None was capable of productively infecting various other actinomyces strains that represented the six actinomyces coaggregation groups. Because phage-containing samples occurred randomly in this survey, no correlation between the individual collecting the samples, dental clinic, or type of patient and the presence of phage in the sample was noted. Examination of one of the samples that yielded phage for the presence of a natural host strain for that particular phage resulted in the isolation of two strains which were identified as A. viscosus serotype II and Actinomyces naeslundii serotype I. This is the first report of an A. naeslundii host strain and actinomyces bacteriophage of human dental plaque origin. The finding of both phage and host strains in the same dental plaque sample along with the observation of high host cell specificity by these phage provide indicators that support an active role for actinomyces bacteriophage in oral microbial ecology. The use of these freshly isolated phage as probes to study actinomyces coaggregation properties is discussed.

  16. Influence of Cigarette Smoking on Burden and Characteristics of Coronary Artery Plaques in Chinese Men

    PubMed Central

    Sun, Yujiao; Yu, Xin; Zhi, Ying; Geng, Song; Li, Hua; Liu, Ting; Xu, Ke; Qi, Guoxian

    2015-01-01

    Background It is generally well-known that smoking has a substantial impact on general health, and cardiovascular health in particular. The purpose of this study was to analyze the effects of different smoking status on the burden and characteristics of coronary artery plaques in Chinese men. Methods Our study enrolled 1920 individuals with suspected coronary artery disease undergoing 256-detector-row computed tomography scan after clinical assessment. These study participants were stratified into three groups: never smoker, current smoker, and former smoker, according to their smoking status. Thereafter, the associations of different smoking status with the coronary artery plaques were assessed using both univariable and multivariable logistic regression. Results The prevalences of any plaque, significant stenosis and coronary artery calcium score (CACS) ≥ 10 were highest in the current smokers (all p < 0.05). The proportion of calcified plaques was the lowest and the prevalence of non-calcified plaques was the highest in current smokers (p = 0.004). The higher pack-years group had significantly elevated percentages of any plaque, significant stenosis, ≥ 2/LM vessel disease and CACS ≥ 10 than the lower pack-years group (all p < 0.001). The percent of calcified plaques was lower and the percent of non-calcified plaques was higher in the higher (> 20) pack-years group than in the lower pack-years group (≤ 20) (p = 0.024). Current smoking with higher pack-years was the independent risk factor for any plaque, significant stenosis, CACS ≥ 10, non-calcified and mixed plaques (all p < 0.05) after multivariate adjustments. Conclusions The current smokers had the most serious burden of coronary artery plaques and the highest percentage of non-calcified plaques. Current smoking with higher pack-years was a significant risk factor for coronary artery plaque burden and non-calcified and mixed plaques. PMID:27122899

  17. Mountain torrents: Quantifying vulnerability and assessing uncertainties

    PubMed Central

    Totschnig, Reinhold; Fuchs, Sven

    2013-01-01

    Vulnerability assessment for elements at risk is an important component in the framework of risk assessment. The vulnerability of buildings affected by torrent processes can be quantified by vulnerability functions that express a mathematical relationship between the degree of loss of individual elements at risk and the intensity of the impacting process. Based on data from the Austrian Alps, we extended a vulnerability curve for residential buildings affected by fluvial sediment transport processes to other torrent processes and other building types. With respect to this goal to merge different data based on different processes and building types, several statistical tests were conducted. The calculation of vulnerability functions was based on a nonlinear regression approach applying cumulative distribution functions. The results suggest that there is no need to distinguish between different sediment-laden torrent processes when assessing vulnerability of residential buildings towards torrent processes. The final vulnerability functions were further validated with data from the Italian Alps and different vulnerability functions presented in the literature. This comparison showed the wider applicability of the derived vulnerability functions. The uncertainty inherent to regression functions was quantified by the calculation of confidence bands. The derived vulnerability functions may be applied within the framework of risk management for mountain hazards within the European Alps. The method is transferable to other mountain regions if the input data needed are available. PMID:27087696

  18. Scenarios for coastal vulnerability assessment

    USGS Publications Warehouse

    Nicholls, Robert J.; Woodroffe, Colin D.; Burkett, Virginia; Hay, John; Wong, Poh Poh; Nurse, Leonard; Wolanski, Eric; McLusky, Donald S.

    2011-01-01

    Coastal vulnerability assessments tend to focus mainly on climate change and especially on sea-level rise. Assessment of the influence of nonclimatic environmental change or socioeconomic change is less well developed and these drivers are often completely ignored. Given that the most profound coastal changes of the twentieth century due to nonclimate drivers are likely to continue through the twenty-first century, this is a major omission. It may result in not only overstating the importance of climate change but also overlooking significant interactions of climate change and other drivers. To support the development of policies relating to climate change and coastal management, integrated assessments of climatic change in coastal areas are required, including the effects of all the relevant drivers. This chapter explores the development of scenarios (or "plausible futures") of relevant climate and nonclimate drivers that can be used for coastal analysis, with an emphasis on the nonclimate drivers. It shows the importance of analyzing the impacts of climate change and sea-level rise in a broader context of coastal change and all its drivers. This will improve the analysis of impacts, key vulnerabilities, and adaptation needs and, hence, inform climate and coastal policy. Stakeholder engagement is important in the development of scenarios, and the underlying assumptions need to be explicit, transparent, and open to scientific debate concerning their uncertainties/realism and likelihood.

  19. Vulnerable to HIV / AIDS. Migration.

    PubMed

    Fernandez, I

    1998-01-01

    This special report discusses the impact of globalization, patterns of migration in Southeast Asia, gender issues in migration, the links between migration and HIV/AIDS, and spatial mobility and social networks. Migrants are particularly marginalized in countries that blame migrants for transmission of infectious and communicable diseases and other social ills. Effective control of HIV/AIDS among migrant and native populations requires a multisectoral approach. Programs should critically review the privatization of health care services and challenge economic models that polarize the rich and the poor, men and women, North and South, and migrant and native. Programs should recognize the equality between locals and migrants in receipt of health services. Countermeasures should have input from migrants in order to reduce the conditions that increase vulnerability to HIV/AIDS. Gender-oriented research is needed to understand women's role in migration. Rapid assessment has obscured the human dimension of migrants' vulnerability to HIV. Condom promotion is not enough. Migration is a major consequence of globalization, which holds the promise, real or imagined, of prosperity for all. Mass migration can be fueled by explosive regional developments. In Southeast Asia, migration has been part of the process of economic development. The potential to emigrate increases with greater per capita income. "Tiger" economies have been labor importers. Safe sex is not practiced in many Asian countries because risk is not taken seriously. Migrants tend to be used as economic tools, without consideration of social adjustment and sex behavior among singles.

  20. Vulnerability of network of networks

    NASA Astrophysics Data System (ADS)

    Havlin, S.; Kenett, D. Y.; Bashan, A.; Gao, J.; Stanley, H. E.

    2014-10-01

    Our dependence on networks - be they infrastructure, economic, social or others - leaves us prone to crises caused by the vulnerabilities of these networks. There is a great need to develop new methods to protect infrastructure networks and prevent cascade of failures (especially in cases of coupled networks). Terrorist attacks on transportation networks have traumatized modern societies. With a single blast, it has become possible to paralyze airline traffic, electric power supply, ground transportation or Internet communication. How, and at which cost can one restructure the network such that it will become more robust against malicious attacks? The gradual increase in attacks on the networks society depends on - Internet, mobile phone, transportation, air travel, banking, etc. - emphasize the need to develop new strategies to protect and defend these crucial networks of communication and infrastructure networks. One example is the threat of liquid explosives a few years ago, which completely shut down air travel for days, and has created extreme changes in regulations. Such threats and dangers warrant the need for new tools and strategies to defend critical infrastructure. In this paper we review recent advances in the theoretical understanding of the vulnerabilities of interdependent networks with and without spatial embedding, attack strategies and their affect on such networks of networks as well as recently developed strategies to optimize and repair failures caused by such attacks.

  1. Dynamics of immune system vulnerabilities

    NASA Astrophysics Data System (ADS)

    Stromberg, Sean P.

    The adaptive immune system can be viewed as a complex system, which adapts, over time, to reflect the history of infections experienced by the organism. Understanding its operation requires viewing it in terms of tradeoffs under constraints and evolutionary history. It typically displays "robust, yet fragile" behavior, meaning common tasks are robust to small changes but novel threats or changes in environment can have dire consequences. In this dissertation we use mechanistic models to study several biological processes: the immune response, the homeostasis of cells in the lymphatic system, and the process that normally prevents autoreactive cells from entering the lymphatic system. Using these models we then study the effects of these processes interacting. We show that the mechanisms that regulate the numbers of cells in the immune system, in conjunction with the immune response, can act to suppress autoreactive cells from proliferating, thus showing quantitatively how pathogenic infections can suppress autoimmune disease. We also show that over long periods of time this same effect can thin the repertoire of cells that defend against novel threats, leading to an age correlated vulnerability. This vulnerability is shown to be a consequence of system dynamics, not due to degradation of immune system components with age. Finally, modeling a specific tolerance mechanism that normally prevents autoimmune disease, in conjunction with models of the immune response and homeostasis we look at the consequences of the immune system mistakenly incorporating pathogenic molecules into its tolerizing mechanisms. The signature of this dynamic matches closely that of the dengue virus system.

  2. SU-E-T-15: A Comparison of COMS and EP917 Eye Plaque Applicators Using Different Radionuclides

    SciTech Connect

    Aryal, P; Molloy, JA; Rivard, MJ

    2015-06-15

    Purpose: To investigate the effect of plaque design and radionuclides on eye plaque dosimetry. Methods: The Monte Carlo N-particle Code version 6 (MCNP6) was used for radiation transport simulations. The 14 mm and 16 mm diameter COMS plaques and the model EP917 plaque were simulated using brachytherapy seeds containing I-125, Pd-103, and Cs-131 radionuclides. The origin was placed at the scleral inner surface. The central axis (CAX) doses of both COMS plaques at −1 mm, 0 mm, 1 mm, 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, and 22.6 mm were compared to the model EP917 plaque. Dose volume histograms (DVHs) were also created for both COMS plaques for the tumor and outer sclera then compared to results for the model EP917 plaque. Results: For all radionuclides, the EP917 plaque delivered higher dose (max 343%) compared to the COMS plaques, except for the 14 mm COMS plaque with Cs-131 at 1 mm and 2 mm depths from outer sclera surface. This could be due to source design. For all radionuclides, the 14 mm COMS plaque delivered higher doses compared to the 16 mm COMS plaque for the depths up to 5 mm. Dose differences were not significant beyond depths of 10 mm due to ocular lateral scatter for the different plaque designs. Tumor DVHs for the 16 mm COMS plaque with Cs-131 provided better dose homogeneity and conformity compared to other COMS plaques with I-125 and Pd-103. Using Pd-103, DVHs for the 16 mm COMS plaque delivered less dose to outer sclera compared to other plaques. Conclusion: This study identified improved tumor homogeneity upon considering radionuclides and plaque designs, and found that scleral dose with the model EP917 plaque was higher than for the 16 mm COMS plaque for all the radionuclides studied.

  3. Assessing human vulnerability: Daytime residential distribution as a vulnerability indicator

    NASA Astrophysics Data System (ADS)

    Gokesch, Karin; Promper, Catrin; Papathoma-Köhle, Maria; Glade, Thomas

    2014-05-01

    Natural hazard risk management is based on detailed information on potential impacts of natural hazards. Especially concerning fast onset hazards such as flash floods, earthquakes but also debris flows and landslides, knowing potential hotspots of impact to both, assets and human lives is essential. This information is important for emergency management and decision making in the response phase of the disaster management cycle. Emergency managers are in need of information regarding not only the number of humans being potentially affected but also the respective vulnerability of the group affected based on characteristics such as age, income, health condition, mobility, etc. regarding a certain hazard. The analysis presented focuses on the distribution of the population, assuming a certain pattern of people in a certain radius of action. The method applied is based on a regular pattern of movement of different groups of people and a pattern of presence in certain units, e.g. schools, businesses or residential buildings. The distribution is calculated on a minimum of available data including the average household size, as well as information on building types. The study area is located in the Southwest of Lower Austria, Austria. The city of Waidhofen/Ybbs can be regarded as a regional center providing basic infrastructure, shops and schools. The high concentration of buildings combining shops and residential units leads to a high damage potential throughout the whole study area. The presented results indicate the population distribution within the study area on an average working day. It is clear that explicitly high numbers of people are located in specific buildings (e.g. schools and hospitals) which also include highly vulnerable groups especially to fast onset hazards. The results provide emergency services with the information that they need in order to intervene directly where large numbers of victims or people that need to be evacuated are located. In this

  4. Regional brain hypometabolism is unrelated to regional amyloid plaque burden

    PubMed Central

    Altmann, Andre; Ng, Bernard; Landau, Susan M.; Jagust, William J.

    2015-01-01

    See Sorg and Grothe (doi:10.1093/brain/awv302) for a scientific commentary on this article. In its original form, the amyloid cascade hypothesis of Alzheimer’s disease holds that fibrillar deposits of amyloid are an early, driving force in pathological events leading ultimately to neuronal death. Early clinicopathological investigations highlighted a number of inconsistencies leading to an updated hypothesis in which amyloid plaques give way to amyloid oligomers as the driving force in pathogenesis. Rather than focusing on the inconsistencies, amyloid imaging studies have tended to highlight the overlap between regions that show early amyloid plaque signal on positron emission tomography and that also happen to be affected early in Alzheimer’s disease. Recent imaging studies investigating the regional dependency between metabolism and amyloid plaque deposition have arrived at conflicting results, with some showing regional associations and other not. We extracted multimodal neuroimaging data from the Alzheimer’s disease neuroimaging database for 227 healthy controls and 434 subjects with mild cognitive impairment. We analysed regional patterns of amyloid deposition, regional glucose metabolism and regional atrophy using florbetapir (18F) positron emission tomography, 18F-fluordeoxyglucose positron emission tomography and T1-weighted magnetic resonance imaging, respectively. Specifically, we derived grey matter density and standardized uptake value ratios for both positron emission tomography tracers in 404 functionally defined regions of interest. We examined the relation between regional glucose metabolism and amyloid plaques using linear models. For each region of interest, correcting for regional grey matter density, age, education and disease status, we tested the association of regional glucose metabolism with (i) cortex-wide florbetapir uptake; (ii) regional (i.e. in the same region of interest) florbetapir uptake; and (iii) regional florbetapir uptake

  5. Intravascular laser speckle imaging for the mechanical analysis of coronary plaques (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hosoda, Masaki; Wang, Jing; Tsikudi, Diane; Nadkarni, Seemantini

    2016-02-01

    Acute myocardial infarction is frequently caused by the rupture of coronary plaques with severely compromised viscoelastic properties. We have developed a new optical technology termed intravascular laser speckle imaging (ILSI) that evaluates plaque viscoelastic properties, by measuring the time scale (time constant, τ) of temporally evolving laser speckle fluctuations. To enable coronary evaluation in vivo, an optical ILSI catheter has been developed that accomplishes omni-directional illumination and viewing of the entire coronary circumference without the need for mechanical rotation. Here, we describe the capability of ILSI for evaluating human coronary atherosclerosis in cadaveric hearts. ILSI was conducted in conjunction with optical coherence tomography (OCT) imaging in five human cadaveric hearts. The left coronary artery (LCA), left anterior descending (LAD), left circumflex artery (LCx), and right coronary artery (RCA) segments were resected and secured on custom-developed coronary holders to enable accurate co-registration between ILSI, OCT, and histopathology. Speckle time constants, τ, calculated from each ILSI section were compared with lipid and collagen content measured from quantitative Histopathological analysis of the corresponding Oil Red O and Picrosirius Red stained sections. Because the presence of low viscosity lipid elicits rapid speckle fluctuations, we observed an inverse correlation between τ measured by ILSI and lipid content (R= -0.64, p< 0.05). In contrast, the higher viscoelastic modulus of fibrous regions resulted in a positive correlation between τ and collagen content (R= 0.54, p< 0.05). These results demonstrate the feasibility of conducting ILSI evaluation of arterial mechanical properties using a miniaturized omni-directional catheter.

  6. An holistic view on aquifer vulnerability based on a distinction of different types of vulnerability

    NASA Astrophysics Data System (ADS)

    De Luca, Domenico Antonio; Lasagna, Manuela; Franchino, Elisa

    2016-04-01

    AN HOLISTIC VIEW ON AQUIFER VULNERABILITY BASED ON A DISTINCTION OF DIFFERENT TYPES OF VULNERABILITY D.A. De Luca1 , M. Lasagna1, E. Franchino1 1Department of Earth Sciences, University of Turin The concept of vulnerability is certainly useful in the field of groundwater protection. Nevertheless, within the scientific community, the definition of groundwater vulnerability is still debatable and not clear and conclusive. This is probably due to the fact that researchers often have very different experiences and education. A positive effect of it is a constant exchange of ideas, but there are also negative consequences and difficulties in deepening the issue. The different approaches are very important but they are usable only if the concept of vulnerability is standardized: thus, for the sake of clarity, a number of definitions should be laid down, based on the different types of vulnerability. These definitions can then provide the necessary holistic view for the aquifer vulnerability assessment. Nowadays vulnerability methods focus on the degree of vulnerability and the parameters needed for its evaluation, often neglecting to clarify what is the type of vulnerability the proposed methods are referred. The type of vulnerability, indeed, is both logically and hierarchically superior to the degree of vulnerability. More specifically the type of vulnerability represents the evaluation of the hydrogeological conditions considered in the vulnerability assessment and able to influence the way in which the contamination can take place. Currently the only distinction, based on of the type of vulnerability, is referred to intrinsic and specific vulnerability. Intrinsic vulnerability assesses the susceptibility of the receptor based on the natural properties of the land and subsurface; specific vulnerability also includes properties of the analyzed contaminant. This distinction is useful but not exhaustive. In addition to this, e.g., a distinction of vertical vulnerability

  7. Metadata for selecting or submitting generic seismic vulnerability functions via GEM's vulnerability database

    USGS Publications Warehouse

    Jaiswal, Kishor

    2013-01-01

    This memo lays out a procedure for the GEM software to offer an available vulnerability function for any acceptable set of attributes that the user specifies for a particular building category. The memo also provides general guidelines on how to submit the vulnerability or fragility functions to the GEM vulnerability repository, stipulating which attributes modelers must provide so that their vulnerability or fragility functions can be queried appropriately by the vulnerability database. An important objective is to provide users guidance on limitations and applicability by providing the associated modeling assumptions and applicability of each vulnerability or fragility function.

  8. NV: Nessus Vulnerability Visualization for the Web

    SciTech Connect

    Harrison, Lane; Spahn, Riley B; Iannacone, Michael D; Downing, Evan P; Goodall, John R

    2012-01-01

    Network vulnerability is a critical component of network se- curity. Yet vulnerability analysis has received relatively lit- tle attention from the security visualization community. In this paper we describe nv, a web-based Nessus vulnerability visualization. Nv utilizes treemaps and linked histograms to allow system administrators to discover, analyze, and man- age vulnerabilities on their networks. In addition to visual- izing single Nessus scans, nv supports the analysis of sequen- tial scans by showing which vulnerabilities have been fixed, remain open, or are newly discovered. Nv was also designed to operate completely in-browser, to avoid sending sensitive data to outside servers. We discuss the design of nv, as well as provide case studies demonstrating vulnerability analysis workflows which include a multiple-node testbed and data from the 2011 VAST Challenge.

  9. Assessing the Security Vulnerabilities of Correctional Facilities

    SciTech Connect

    Morrison, G.S.; Spencer, D.S.

    1998-10-27

    The National Institute of Justice has tasked their Satellite Facility at Sandia National Laboratories and their Southeast Regional Technology Center in Charleston, South Carolina to devise new procedures and tools for helping correctional facilities to assess their security vulnerabilities. Thus, a team is visiting selected correctional facilities and performing vulnerability assessments. A vulnerability assessment helps to identi~ the easiest paths for inmate escape, for introduction of contraband such as drugs or weapons, for unexpected intrusion fi-om outside of the facility, and for the perpetration of violent acts on other inmates and correctional employees, In addition, the vulnerability assessment helps to quantify the security risks for the facility. From these initial assessments will come better procedures for performing vulnerability assessments in general at other correctional facilities, as well as the development of tools to assist with the performance of such vulnerability assessments.

  10. Vulnerability and resilience: a critical nexus.

    PubMed

    Lotz, Mianna

    2016-02-01

    Not all forms of human fragility or vulnerability are unavoidable. Sometimes we knowingly and intentionally impose conditions of vulnerability on others; and sometimes we knowingly and intentionally enter into and assume conditions of vulnerability for ourselves (for example, when we decide to trust or forgive, enter into intimate relationships with others, become a parent, become a subject of medical or psychotherapeutic treatment, and the like). In this article, I propose a presently overlooked basis on which one might evaluate whether the imposition or assumption of vulnerability is acceptable, and on which one might ground a significant class of vulnerability-related obligations. Distinct from existing accounts of the importance of promoting autonomy in conditions of vulnerability, this article offers a preliminary exploration of the nature, role, and importance of resilience promotion, its relationship to autonomy promotion, and its prospects for improving human wellbeing in autonomy inhibiting conditions.

  11. Fiber-Optic System for Dual-Modality Imaging of Glucose Probes 18F-FDG and 6-NBDG in Atherosclerotic Plaques

    PubMed Central

    Zaman, Raiyan T.; Kosuge, Hisanori; Pratx, Guillem; Carpenter, Colin; Xing, Lei; McConnell, Michael V.

    2014-01-01

    Background Atherosclerosis is a progressive inflammatory condition that underlies coronary artery disease (CAD)–the leading cause of death in the United States. Thus, the ultimate goal of this research is to advance our understanding of human CAD by improving the characterization of metabolically active vulnerable plaques within the coronary arteries using a novel catheter-based imaging system. The aims of this study include (1) developing a novel fiber-optic imaging system with a scintillator to detect both 18F and fluorescent glucose probes, and (2) validating the system on ex vivo murine plaques. Methods A novel design implements a flexible fiber-optic catheter consisting of both a radio-luminescence and a fluorescence imaging system to detect radionuclide 18F-fluorodeoxyglucose (18F-FDG) and the fluorescent analog 6-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-6-Deoxyglucose (6-NBDG), respectively. Murine macrophage-rich atherosclerotic carotid plaques were imaged ex vivo after intravenous delivery of 18F-FDG or 6-NBDG. Confirmatory optical imaging by IVIS-200 and autoradiography were also performed. Results Our fiber-optic imaging system successfully visualized both 18F-FDG and 6-NBDG probes in atherosclerotic plaques. For 18F-FDG, the ligated left carotid arteries (LCs) exhibited 4.9-fold higher radioluminescence signal intensity compared to the non-ligated right carotid arteries (RCs) (2.6×104±1.4×103 vs. 5.4×103±1.3×103 A.U., P = 0.008). Similarly, for 6-NBDG, the ligated LCs emitted 4.3-fold brighter fluorescent signals than the control RCs (1.6×102±2.7×101 vs. 3.8×101±5.9 A.U., P = 0.002). The higher uptake of both 18F-FDG and 6-NBDG in ligated LCs were confirmed with the IVIS-200 system. Autoradiography further verified the higher uptake of 18F-FDG by the LCs. Conclusions This novel fiber-optic imaging system was sensitive to both radionuclide and fluorescent glucose probes taken up by murine atherosclerotic plaques. In addition, 6

  12. Efficacy of two soft-bristle toothbrushes in plaque removal: a randomized controlled trial.

    PubMed

    Rosing, Cassiano Kuchenbecker; Cavagni, Juliano; Gaio, Eduardo José; Muniz, Francisco Wilker Mustafa Gomes; Oballe, Harry Juan Rivera; Ranzan, Nicolle; Friedrich, Stephanie Anagnostopoulos; Severo, Raísa Maldonado; Gittins, Elizabeth; Stewart, Bernal; Zhang, Yun Po

    2016-11-10

    The aim of this study was to compare the efficacy in supragingival plaque removal of two soft-bristle toothbrushes. Seventy volunteers were allocated randomly to the Colgate Slim Soft or Curaprox CS5460 toothbrush grourps. At baseline appointment, volunteers underwent plaque examination using the Rustogi Modification of the Navy Plaque Index. Under supervision, they then brushed their teeth for 1minute with their assigned toothbrushes and the plaque examination was repeated. Volunteers performed daily oral hygiene with their assigned toothbrush and a regular dentifrice provided by the researchers for 7 days. The baseline experimental procedures were then repeated. Separate analyses of variance were performed for the whole-mouth, interproximal, and gumline plaque scores (p < 0.05). No difference in baseline pre-brushing scores was found between groups. After a single toothbrushing, the mean plaque score was significantly reduced in both groups (p < 0.05), with greater reduction of whole-mouth and interproximal plaque scores observed in the SlimSoft group compared with the Curaprox group (p < 0.05). After 7 days, the SlimSoft group showed greater reduction of the whole-mouth and interproximal plaque scores compared with the Curaprox group (p < 0.05). In conclusion, the SlimSoft toothbrush presented greater efficacy in supragingival plaque removal than did the Curaprox CS5460 toothbrush, as reflected by whole-mouth and interproximal plaque scores.

  13. Consistent detection of Felis domesticus papillomavirus 2 DNA sequences within feline viral plaques.

    PubMed

    Munday, John S; Peters-Kennedy, Jeanine

    2010-11-01

    Viral plaques are well recognized skin lesions of cats. They are thought to be caused by papillomavirus infection; however, the causative papillomavirus is uncertain. In the current study, polymerase chain reaction using 2 consensus primer sets and 1 primer set specific for Felis domesticus papillomavirus 2 (FdPV-2) was used to amplify DNA from a series of 14 feline viral plaques. The FdPV-2 sequences were detected in all 14 viral plaques by the specific primers but in only 1 of 14 feline cutaneous trichoblastomas. Papillomavirus DNA was amplified from 8 plaques using the consensus primers. Sequences from FdPV-2 were amplified using the consensus primers from 4 plaques. In addition, 3 plaques contained papillomavirus DNA sequences from Felis domesticus papillomavirus sequence MY1, and a previously unreported papillomavirus DNA sequence was amplified from 1 plaque. As FdPV-2 was consistently present within the plaques, this suggests that this papillomavirus is the likely etiologic agent. Feline viral plaques can undergo neoplastic transformation to Bowenoid in situ carcinomas (BISCs). As FdPV-2 DNA is frequently present within BISCs, this suggests that FdPV-2 induces viral plaque formation and then remains detectible after neoplastic transformation.

  14. Primary Stenting for Complex Atherosclerotic Plaques in Aortic and Iliac Stenoses

    SciTech Connect

    Onal, Baran; Ilgit, Erhan T.; Yuecel, Cem; Ozbek, Erdal; Vural, Murat; Akpek, Sergin

    1998-09-15

    Purpose: To evaluate the efficacy of primary stenting for complex atherosclerotic plaques in aortic and iliac stenoses that are not amenable to balloon angioplasty alone. Methods: Nineteen patients with complex atherosclerotic plaques were treated with a Palmaz stent (n= 19), Wallstent (n= 1), Strecker stent (n= 1), or Memotherm stent (n= 1). A total of 22 stenoses presenting with complex plaque morphology including ulcerated plaques, ulcerated plaques with focal aneurysms, plaques with heavy calcification, severely eccentric plaques, plaques with overhanging edge, and plaques with spontaneous dissection were stented. The lesions were in the aorta (n= 1), common iliac artery (n= 19), or external iliac artery (n= 2). Results: Immediate angiography after stent placement revealed restoration of patency of the stented segment. Focal aneurysms and ulcerated areas were occluded in the follow-up angiographies obtained 4-12 weeks after the procedure. In one case with poor distal runoff and multiple complex lesions of the iliac artery, subacute occlusion occurred. Clinical and angiographic follow-up (3-46 months) revealed patency of all other stented segments. Conclusion: Primary stenting is an effective and reliable approach for complex plaques in stenoses. Patency of the arterial segment with a smooth lumen can be created without the risk of acute complications such as distal embolization, dissection, or occlusion.

  15. Mining Bug Databases for Unidentified Software Vulnerabilities

    SciTech Connect

    Dumidu Wijayasekara; Milos Manic; Jason Wright; Miles McQueen

    2012-06-01

    Identifying software vulnerabilities is becoming more important as critical and sensitive systems increasingly rely on complex software systems. It has been suggested in previous work that some bugs are only identified as vulnerabilities long after the bug has been made public. These vulnerabilities are known as hidden impact vulnerabilities. This paper discusses the feasibility and necessity to mine common publicly available bug databases for vulnerabilities that are yet to be identified. We present bug database analysis of two well known and frequently used software packages, namely Linux kernel and MySQL. It is shown that for both Linux and MySQL, a significant portion of vulnerabilities that were discovered for the time period from January 2006 to April 2011 were hidden impact vulnerabilities. It is also shown that the percentage of hidden impact vulnerabilities has increased in the last two years, for both software packages. We then propose an improved hidden impact vulnerability identification methodology based on text mining bug databases, and conclude by discussing a few potential problems faced by such a classifier.

  16. Proteomic differences in amyloid plaques in rapidly progressive and sporadic Alzheimer's disease.

    PubMed

    Drummond, Eleanor; Nayak, Shruti; Faustin, Arline; Pires, Geoffrey; A Hickman, Richard; Askenazi, Manor; Cohen, Mark; Haldiman, Tracy; Kim, Chae; Han, Xiaoxia; Shao, Yongzhao; Safar, Jiri G; Ueberheide, Beatrix; Wisniewski, Thomas

    2017-03-04

    Rapidly progressive Alzheimer's disease (rpAD) is a particularly aggressive form of Alzheimer's disease, with a median survival time of 7-10 months after diagnosis. Why these patients have such a rapid progression of Alzheimer's disease is currently unknown. To further understand pathological differences between rpAD and typical sporadic Alzheimer's disease (sAD) we used localized proteomics to analyze the protein differences in amyloid plaques in rpAD and sAD. Label-free quantitative LC-MS/MS was performed on amyloid plaques microdissected from rpAD and sAD patients (n = 22 for each patient group) and protein expression differences were quantified. On average, 913 ± 30 (mean ± SEM) proteins were quantified in plaques from each patient and 279 of these proteins were consistently found in plaques from every patient. We found significant differences in protein composition between rpAD and sAD plaques. We found that rpAD plaques contained significantly higher levels of neuronal proteins (p = 0.0017) and significantly lower levels of astrocytic proteins (p = 1.08 × 10(-6)). Unexpectedly, cumulative protein differences in rpAD plaques did not suggest accelerated typical sAD. Plaques from patients with rpAD were particularly abundant in synaptic proteins, especially those involved in synaptic vesicle release, highlighting the potential importance of synaptic dysfunction in the accelerated development of plaque pathology in rpAD. Combined, our data provide new direct evidence that amyloid plaques do not all have the same protein composition and that the proteomic differences in plaques could provide important insight into the factors that contribute to plaque development. The cumulative protein differences in rpAD plaques suggest rpAD may be a novel subtype of Alzheimer's disease.

  17. Proliferation Vulnerability Red Team report

    SciTech Connect

    Hinton, J.P.; Barnard, R.W.; Bennett, D.E.

    1996-10-01

    This report is the product of a four-month independent technical assessment of potential proliferation vulnerabilities associated with the plutonium disposition alternatives currently under review by DOE/MD. The scope of this MD-chartered/Sandia-led study was limited to technical considerations that could reduce proliferation resistance during various stages of the disposition processes below the Stored Weapon/Spent Fuel standards. Both overt and covert threats from host nation and unauthorized parties were considered. The results of this study will be integrated with complementary work by others into an overall Nonproliferation and Arms Control Assessment in support of a Secretarial Record of Decision later this year for disposition of surplus U.S. weapons plutonium.

  18. Attack Vulnerability of Network Controllability

    PubMed Central

    2016-01-01

    Controllability of complex networks has attracted much attention, and understanding the robustness of network controllability against potential attacks and failures is of practical significance. In this paper, we systematically investigate the attack vulnerability of network controllability for the canonical model networks as well as the real-world networks subject to attacks on nodes and edges. The attack strategies are selected based on degree and betweenness centralities calculated for either the initial network or the current network during the removal, among which random failure is as a comparison. It is found that the node-based strategies are often more harmful to the network controllability than the edge-based ones, and so are the recalculated strategies than their counterparts. The Barabási-Albert scale-free model, which has a highly biased structure, proves to be the most vulnerable of the tested model networks. In contrast, the Erdős-Rényi random model, which lacks structural bias, exhibits much better robustness to both node-based and edge-based attacks. We also survey the control robustness of 25 real-world networks, and the numerical results show that most real networks are control robust to random node failures, which has not been observed in the model networks. And the recalculated betweenness-based strategy is the most efficient way to harm the controllability of real-world networks. Besides, we find that the edge degree is not a good quantity to measure the importance of an edge in terms of network controllability. PMID:27588941

  19. Manual planimetric measurement of carotid plaque volume using three-dimensional ultrasound imaging

    SciTech Connect

    Landry, Anthony; Ainsworth, Craig; Blake, Chris; Spence, J. David; Fenster, Aaron

    2007-04-15

    We investigated the utility of three manual planimetric methods to quantify carotid plaque volume. A single observer measured 15 individual plaques from 15 three-dimensional (3D) ultrasound (3D US) images of patients ten times each using three different planimetric approaches. Individual plaque volumes were measured (range: 32.6-597.1 mm{sup 3}) using a standard planimetric approach (M1) whereby a plaque end was identified and sequential contours were measured. The same plaques were measured using a second approach (M2), whereby plaque ends were first identified and the 3D US image of the plaque was then subdivided into equal intervals. A third method (M3) was used to measure total plaque burden (range: 165.1-1080.0 mm{sup 3}) in a region ({+-}1.5 cm) relative to the carotid bifurcation. M1 systematically underestimated individual plaque volume compared to M2 (V{sub 2}=V{sub 1}+14.0 mm{sup 3}, r=0.99, p=0.006) due to a difference in the mean plaque length measured. Coefficients of variance (CV) for M1 and M2 decrease with increasing plaque volume, with M2 results less than M1. Root mean square difference between experimental and theoretical CV for M2 was 3.2%. The standard deviation in the identification of the transverse location of the carotid bifurcation was 0.56 mm. CVs for plaque burden measured using M3 ranged from 1.2% to 7.6% and were less than CVs determined for individual plaque volumes of the same volume. The utility of M3 was demonstrated by measuring carotid plaque burden and volume change over a period of 3 months in three patients. In conclusion, M2 was determined to be a more superior measurement technique than M1 to measure individual plaque volume. Furthermore, we demonstrated the utility of M3 to quantify regional plaque burden and to quantify change in plaque volume.

  20. Modeling Coastal Vulnerability through Space and Time.

    PubMed

    Hopper, Thomas; Meixler, Marcia S

    2016-01-01

    Coastal ecosystems experience a wide range of stressors including wave forces, storm surge, sea-level rise, and anthropogenic modification and are thus vulnerable to erosion. Urban coastal ecosystems are especially important due to the large populations these limited ecosystems serve. However, few studies have addressed the issue of urban coastal vulnerability at the landscape scale with spatial data that are finely resolved. The purpose of this study was to model and map coastal vulnerability and the role of natural habitats in reducing vulnerability in Jamaica Bay, New York, in terms of nine coastal vulnerability metrics (relief, wave exposure, geomorphology, natural habitats, exposure, exposure with no habitat, habitat role, erodible shoreline, and surge) under past (1609), current (2015), and future (2080) scenarios using InVEST 3.2.0. We analyzed vulnerability results both spatially and across all time periods, by stakeholder (ownership) and by distance to damage from Hurricane Sandy. We found significant differences in vulnerability metrics between past, current and future scenarios for all nine metrics except relief and wave exposure. The marsh islands in the center of the bay are currently vulnerable. In the future, these islands will likely be inundated, placing additional areas of the shoreline increasingly at risk. Significant differences in vulnerability exist between stakeholders; the Breezy Point Cooperative and Gateway National Recreation Area had the largest erodible shoreline segments. Significant correlations exist for all vulnerability (exposure/surge) and storm damage combinations except for exposure and distance to artificial debris. Coastal protective features, ranging from storm surge barriers and levees to natural features (e.g. wetlands), have been promoted to decrease future flood risk to communities in coastal areas around the world. Our methods of combining coastal vulnerability results with additional data and across multiple time

  1. Modeling Coastal Vulnerability through Space and Time

    PubMed Central

    2016-01-01

    Coastal ecosystems experience a wide range of stressors including wave forces, storm surge, sea-level rise, and anthropogenic modification and are thus vulnerable to erosion. Urban coastal ecosystems are especially important due to the large populations these limited ecosystems serve. However, few studies have addressed the issue of urban coastal vulnerability at the landscape scale with spatial data that are finely resolved. The purpose of this study was to model and map coastal vulnerability and the role of natural habitats in reducing vulnerability in Jamaica Bay, New York, in terms of nine coastal vulnerability metrics (relief, wave exposure, geomorphology, natural habitats, exposure, exposure with no habitat, habitat role, erodible shoreline, and surge) under past (1609), current (2015), and future (2080) scenarios using InVEST 3.2.0. We analyzed vulnerability results both spatially and across all time periods, by stakeholder (ownership) and by distance to damage from Hurricane Sandy. We found significant differences in vulnerability metrics between past, current and future scenarios for all nine metrics except relief and wave exposure. The marsh islands in the center of the bay are currently vulnerable. In the future, these islands will likely be inundated, placing additional areas of the shoreline increasingly at risk. Significant differences in vulnerability exist between stakeholders; the Breezy Point Cooperative and Gateway National Recreation Area had the largest erodible shoreline segments. Significant correlations exist for all vulnerability (exposure/surge) and storm damage combinations except for exposure and distance to artificial debris. Coastal protective features, ranging from storm surge barriers and levees to natural features (e.g. wetlands), have been promoted to decrease future flood risk to communities in coastal areas around the world. Our methods of combining coastal vulnerability results with additional data and across multiple time

  2. Randall's plaque: pathogenesis and role in calcium oxalate nephrolithiasis.

    PubMed

    Evan, A; Lingeman, J; Coe, F L; Worcester, E

    2006-04-01

    The purpose of these studies was to test the hypothesis that Randall's plaque develops in unique anatomical sites of the kidney and their formation is conditioned by specific stone-forming pathophysiologies. We performed intraoperative papillary biopsies from kidneys of idiopathic-calcium oxalate (CaOx), intestinal bypass for obesity, brushite (BR) and cystine stone formers (SF) during percutaneous nephrolithotomy. Tissues were examined by infrared analysis and light and electron microscopy. Our analysis revealed a distinct pattern of mineral deposition and papillary pathology for each type of SF. CaOx SF had interstitial apatite crystals beginning at thin loops of Henle. These deposits termed Randall's plaque are thought to serve as sites for stone attachment. No tubular injury was noted. Intestinal bypass patients possessed intraluminal apatite deposits in inner medullary collecting ducts (IMCD) with associated cell injury. BR SF showed the most severe form of cortical and medullary changes with sites of Randall's plaque, and yellowish intraluminal deposits of apatite in IMCD. Cystine SF had plugging of ducts of Bellini with cystine crystals and apatite deposits in IMCD and loops of Henle. Intratubular sites of crystalline deposits were always associated to adjacent regions of interstitial fibrosis. The metabolic, anatomic, and surgical pathologic findings in four distinct groups of SF clearly show that 'the histology of the renal papilla from a stone former, is particular to the clinical setting'. We believe our approach to studying stone disease will provide insights into the pathogenesis of stone formation for each type of SF that will lead to improved clinical treatment.

  3. The effect of miswak extract on plaque pH. An in vivo study.

    PubMed

    Sofrata, A; Lingström, P; Baljoon, M; Gustafsson, A

    2007-01-01

    The aim of this study was to document changes in plaque pH when an acidic challenge was followed by rinsing with miswak extract (Salvadora persica), and to evaluate the effect of miswak rinse on parotid gland secretion rate. Plaque pH was measured in 3-day-old plaque using the microtouch electrode. Rinsing with miswak extract, compared with water rinsing, resulted in protracted elevation of plaque pH (>6.0). The difference in plaque pH between miswak extract and water rinse was statistically significant at 30 min (p < 0.001). Rinsing with miswak extract stimulated parotid gland secretion (p < 0.01). In conclusion, miswak extract raised the plaque pH, suggesting a potential role in caries prevention.

  4. Effect of iron plaque on antimony uptake by rice (Oryza sativa L.).

    PubMed

    Cui, Xiao-Dan; Wang, Yu-Jun; Hockmann, Kerstin; Zhou, Dong-Mei

    2015-09-01

    Although iron (Fe) plaque has been shown to significantly affect the uptake of toxic antimony (Sb) by rice, knowledge about the influence of iron plaque on antimony (Sb) (amount, mechanisms, etc) is, however, limited. Here, the effect of Fe plaque on Sb(III) and Sb(V) (nominal oxidation states) uptake by rice (Oryza sativa L.) was investigated using hydroponic experiments and synchrotron-based techniques. The results showed that iron plaque immobilized Sb on the surface of rice roots. Although the binding capacity of iron plaque for Sb(III) was markedly greater than that for Sb(V), significantly more Sb(III) was taken up by roots and transported to shoots. In the presence of Fe plaque, Sb uptake into rice roots was significantly reduced, especially for Sb(III). However, this did not translate into decreasing Sb concentrations in rice shoots and even increased shoot Sb concentrations during high Fe-Sb(III) treatment.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Autoimmune hemolytic anemia during adalimumab treatment for plaque psoriasis.

    PubMed

    Harada, Yukinori; Yamamoto, Hiroaki; Sato, Midori; Kodaira, Mutsuki; Kono, Tsunesuke

    2015-01-01

    Adalimumab is commonly used to treat autoimmune diseases with few reported hematological adverse reactions. We herein describe the case of an 85-year-old Japanese man with plaque psoriasis who developed autoimmune hemolytic anemia (AIHA) after 3 years of adalimumab treatment. The patient suddenly developed hematuria and dyspnea on exertion while receiving adalimumab treatment. Laboratory data showed low hemoglobin levels and slightly increased reticulocyte counts, while direct and indirect antiglobulin tests were positive. The patient was diagnosed with AIHA which resolved after replacing the adalimumab treatment with prednisolone therapy. The findings from this case indicate that AIHA may be caused by long-term adalimumab treatment.

  7. First isolation of Streptococcus downei from human dental plaques.

    PubMed

    Yoo, So Young; Kim, Kwan-Joong; Lim, Seong-Hoon; Kim, Kwang-Won; Hwang, Ho-Keel; Min, Byung-Moo; Choe, Son-Jin; Kook, Joong-Ki

    2005-08-15

    In this study, we isolated four bacterial strains grown on mitis-salivarius sucrose bacitracin agar. The strains had similar biochemical characteristics to biotypes I or II of mutans streptococci. The four isolates were identified as Streptococcus downei by 16S rDNA and dextranase gene (dex) sequencing as well as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dex. To our knowledge, this is the first report of the isolation and identification of S. downei from dental plaque in humans. The results suggest that S. downei can inhabit the human oral cavity.

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

    PubMed Central

    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. PMID:28300927

  9. Plaque pH modulations of children's favourite snacks.

    PubMed

    Gauba, K; Goyal, A; Tewari, A

    1991-03-01

    Cariogenic potential of a few children's favourite snacks, assessed by evaluation of pH modulations on their respective consumption after 2,5,10,20,30 and 40 minutes compared to 10 percent sucrose control using pooled plaque method, in 8-12 years old children revealed lollipop (hard sucking candy) to be the most cariogenic and samosa without chutney to be the least cariogenic. The cariogenic potential of ice creams were similar, however, low as compared to sucrose solution of 10 percent.

  10. Can Chemical Mouthwash Agents Achieve Plaque/Gingivitis Control?

    PubMed

    Van der Weijden, Fridus A; Van der Sluijs, Eveline; Ciancio, Sebastian G; Slot, Dagmar E

    2015-10-01

    Also note that structured abstracts are not allowed per journal style: What is the effect of a mouthwash containing various active chemical ingredients on plaque control and managing gingivitis in adults based on evidence gathered from existing systematic reviews? The summarized evidence suggests that mouthwashes containing chlorhexidine(CHX) and essential oils (EO) had a large effect supported by a strong body of evidence. Also there was strong evidence for a moderate effect of cetylpyridinium chloride(CPC). Evidence suggests that a CHX mouthwash is the first choice, the most reliable alternative is EO. No difference between CHX and EO with respect to gingivitis was observed.

  11. Callahan's Vulnerability Thesis and "Dissatisfaction Theory."

    ERIC Educational Resources Information Center

    Iannaccone, Laurence

    1996-01-01

    In discussing school superintendent vulnerability, the paper addresses diverse meanings among scholars of Callahan's vulnerability thesis, highlighting other articles within this theme issue. The paper reflects on discussions of Callahan's "Education and the Cult of Efficacy" before its 1962 publication and investigates the relation…

  12. Predicting Vulnerability Risks Using Software Characteristics

    ERIC Educational Resources Information Center

    Roumani, Yaman

    2012-01-01

    Software vulnerabilities have been regarded as one of the key reasons for computer security breaches that have resulted in billions of dollars in losses per year (Telang and Wattal 2005). With the growth of the software industry and the Internet, the number of vulnerability attacks and the ease with which an attack can be made have increased. From…

  13. Vulnerable Youth and Transitions to Adulthood

    ERIC Educational Resources Information Center

    Xie, Rongbing; Sen, Bisakha; Foster, E. Michael

    2014-01-01

    This chapter focuses on vulnerable youth, the challenges they face during their transitions to adulthood, and the adverse effects of limited support systems on those transitions. The authors offer recommendations on how adult educators can help facilitate smooth transitions into adulthood for vulnerable youth.

  14. View of Commemorative plaque left on moon at Hadley-Apennine landing site

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A close-up view of a commemorative plaque left on the Moon at the Hadley-Apennine landing site in memory of 14 NASA astronauts and USSR cosmonauts, now deceased. Their names are inscribed in alphabetical order on the plaque. The plaque was stuck in the lunar soil by Astronauts David R. Scott and James B. Irwin during their Apollo 15 lunar surface extravehicular activity. The tin, man-like object represents the figure of a fallen astronaut/cosmonaut.

  15. In vivo fluorescence imaging of β-amyloid plaques with push-pull dimethylaminothiophene derivatives.

    PubMed

    Watanabe, Hiroyuki; Ono, Masahiro; Saji, Hideo

    2015-12-14

    In vivo fluorescence imaging of β-amyloid (Aβ) plaques in the brain is expected to be used as a new method for detecting Alzheimer's disease (AD). We synthesized novel push-pull dimethylaminothiophenyl (DTM) derivatives and evaluated their utility as in vivo fluorescence imaging probes targeting Aβ plaques. As a result, we found that DTM-2 is a promising fluorescent probe for Aβ plaques in the AD brains.

  16. The Effects of Sanguinaria Extract on Plaque Retention and Gingival Health in Active Orthodontic Patients.

    DTIC Science & Technology

    1985-01-01

    techniques to obtain adequate plaque removal. Failure to manage plaque removal during orthodontic treatment may lead to early loss of tooth support2 and an...demonstrating a technique of plaque removal that is effective before orthodontic treatment begins. This is fol- lowed by positive reinforcement...Zachrisson, B.U. and Zachrisson, S. Carie Incidence and Oral Hygiene During Orthodontic Treatment . Scand. J. Dent. Res. 79:394-401, 1971. 4. Alexander, C.M

  17. Paradoxic decreases in atherosclerotic plaque mass in insulin-treated diabetic patients.

    PubMed

    Kornowski, R; Mintz, G S; Lansky, A J; Hong, M K; Kent, K M; Pichard, A D; Satler, L F; Popma, J J; Bucher, T A; Leon, M B

    1998-06-01

    This study assessed the impact of diabetes mellitus on atherosclerotic lesion formation. Seventy insulin-treated diabetics, 150 non-insulin-treated diabetics, and 607 nondiabetics with chronic anginal syndromes and de novo native coronary stenoses were studied using (1) angiography, and (2) intravascular ultrasound (reference and lesion arterial, lumen, and plaque areas; area stenosis [reference-lesion/reference lumen area]; remodeling index [reference-lesion lumen area/lesion-reference plaque area]; and slope of the regression line relating lumen area to plaque burden [plaque/arterial area]). Despite being diabetic for longer and having similar lumen compromise, insulin-treated patients had (1) less reference plaque (8.3 +/- 3.4 vs 10.5 +/- 4.5 mm2, p = 0.0015), (2) less stenosis plaque (13.0 +/- 4.9 vs 16.9 mm2, p <0.0001), (3) smaller reference arterial areas (17.1 +/- 5.4 vs 19.7 +/- 6.2 mm2, p = 0.0063), and (4) smaller stenosis arterial areas (15.3 +/- 4.9 vs 19.5 +/- 6.5 mm2, p <0.0001) than non-insulin-treated diabetics. With use of multivariate linear regression analysis, insulin use was an independent (and negative) predictor of reference plaque and arterial areas (p = 0.0308 and p = 0.0179) and stenosis plaque and arterial areas (p = 0.0117 and p = 0.0066). This was also true when normalized for body surface area. The remodeling index showed that insulin treatment resulted in an exaggerated impact of plaque accumulation on lumen compromise. This was confirmed by the slope of the regression line relating lumen area to plaque burden. Patients with a longer duration of diabetes who were treated with insulin for > or = 1 year had (paradoxically) less reference segment and stenosis plaque accumulation. Possible explanations include impaired adaptive remodeling and/or arterial (and plaque) shrinkage.

  18. Quantitative evaluation of specific vulnerability to nitrate for groundwater resource protection based on process-based simulation model.

    PubMed

    Huan, Huan; Wang, Jinsheng; Zhai, Yuanzheng; Xi, Beidou; Li, Juan; Li, Mingxiao

    2016-04-15

    It has been proved that groundwater vulnerability assessment is an effective tool for groundwater protection. Nowadays, quantitative assessment methods for specific vulnerability are scarce due to limited cognition of complicated contaminant fate and transport processes in the groundwater system. In this paper, process-based simulation model for specific vulnerability to nitrate using 1D flow and solute transport model in the unsaturated vadose zone is presented for groundwater resource protection. For this case study in Jilin City of northeast China, rate constants of denitrification and nitrification as well as adsorption constants of ammonium and nitrate in the vadose zone were acquired by laboratory experiments. The transfer time at the groundwater table t50 was taken as the specific vulnerability indicator. Finally, overall vulnerability was assessed by establishing the relationship between groundwater net recharge, layer thickness and t50. The results suggested that the most vulnerable regions of Jilin City were mainly distributed in the floodplain of Songhua River and Mangniu River. The least vulnerable areas mostly appear in the second terrace and back of the first terrace. The overall area of low, relatively low and moderate vulnerability accounted for 76% of the study area, suggesting the relatively low possibility of suffering nitrate contamination. In addition, the sensitivity analysis showed that the most sensitive factors of specific vulnerability in the vadose zone included the groundwater net recharge rate, physical properties of soil medium and rate constants of nitrate denitrification. By validating the suitability of the process-based simulation model for specific vulnerability and comparing with index-based method by a group of integrated indicators, more realistic and accurate specific vulnerability mapping could be acquired by the process-based simulation model acquiring. In addition, the advantages, disadvantages, constraint conditions and

  19. Chemical facility vulnerability assessment project.

    PubMed

    Jaeger, Calvin D

    2003-11-14

    Sandia National Laboratories, under the direction of the Office of Science and Technology, National Institute of Justice, conducted the chemical facility vulnerability assessment (CFVA) project. The primary objective of this project was to develop, test and validate a vulnerability assessment methodology (VAM) for determining the security of chemical facilities against terrorist or criminal attacks (VAM-CF). The project also included a report to the Department of Justice for Congress that in addition to describing the VAM-CF also addressed general observations related to security practices, threats and risks at chemical facilities and chemical transport. In the development of the VAM-CF Sandia leveraged the experience gained from the use and development of VAs in other areas and the input from the chemical industry and Federal agencies. The VAM-CF is a systematic, risk-based approach where risk is a function of the severity of consequences of an undesired event, the attack potential, and the likelihood of adversary success in causing the undesired event. For the purpose of the VAM-CF analyses Risk is a function of S, L(A), and L(AS), where S is the severity of consequence of an event, L(A) is the attack potential and L(AS) likelihood of adversary success in causing a catastrophic event. The VAM-CF consists of 13 basic steps. It involves an initial screening step, which helps to identify and prioritize facilities for further analysis. This step is similar to the prioritization approach developed by the American Chemistry Council (ACC). Other steps help to determine the components of the risk equation and ultimately the risk. The VAM-CF process involves identifying the hazardous chemicals and processes at a chemical facility. It helps chemical facilities to focus their attention on the most critical areas. The VAM-CF is not a quantitative analysis but, rather, compares relative security risks. If the risks are deemed too high, recommendations are developed for

  20. [Correlation between autophagy and polarization of macrophages in atherosclerosis plaque in arteriosclerosis obliterans amputees].

    PubMed

    Chen, Wen-na; Guo, Sheng-nan; Wang, Jun-yan; Jia, Lian-qun; Li, Da-yong; Tian, Ying

    2016-01-01

    This study was designed to investigate the correlation between autophagy and polarization of macrophages in atherosclerosis (AS) plaque in arteriosclerosis obliterans amputees. Femoral artery specimens from arteriosclerosis obliterans amputees were performed hematoxylin and eosin (HE) staining, oil red O and immunofluorescence staining to observe the morphology of atherosclerotic plaque, phenotype of macrophages and autophagy in plaque; using real-time quantitative RT-PCR technology to detect the mRNA level of M1 and M2 type markers in arterial tissue; to analyze polarized signal pathway and autophagy protein levels in macrophages by Western blotting. Arterial specimens staining showed obvious lipid deposition and obvious infiltration of amount of foam cells and inflammatory cells. Macrophages were mainly expression M1 type in percentage in fibrous plaque. Although both M1 and M2 macrophages were upregulated in atheromatous plaque, the increase was dominant in M2 type in percentage. The level of autophagy was significantly higher in the atheromatous plaque than that of fibrous plaque. The expression of tumor necrosis factor- α (TNF-α), monocyte chemotactic protein-1 (MCP-1), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6) and interleukin-12 (IL-12) mRNA was significantly higher in fibrous plaque than that of atheromatous plaque (P < 0.01 or 0.05), and arginase-1 (Arg-1), transforming growth factor-β (TGF-β), CD163 and interleukin-10 (IL-10) mRNA was significantly lower than that in atheromatous plaque (P < 0.01). The levels of p-STAT1 and NF-κB were significantly increased in fibrous plaque (P < 0.01), while p-STAT6 expression was significantly increased in atheromatous plaque (P < 0.01). The level of LC3-II was significantly higher in atheromatous plaque than that in fibrous plaque (P < 0.01). Macrophages in early atherosclerotic plaque were induced to M1 type through p-STAT1/NF-κB pathway and expressed moderate levels of autophagy; while

  1. Immunohistochemical analysis of constituents of senile plaques and cerebro-vascular amyloid in aged dogs.

    PubMed

    Uchida, K; Nakayama, H; Tateyama, S; Goto, N

    1992-10-01

    Immunohistochemical analysis of constituents of senile plaques and cerebro-vascular amyloid in the brain of aged dogs was performed using antisera against beta protein, cystatin C, ubiquitin, tau, and neurofilament (NF). All types of senile plaques and cerebro-vascular amyloid in aged dogs were labeled by anti-beta protein serum. Cystatin C immunoreactivity was detected in neuronal cell bodies, primitive or classical plaques, and amyloid deposited around cerebral capillaries, but not in diffuse plaques and amyloid deposited in the media tunica of cerebro-meningeal arterioles. Ubiquitin-positive granules distributed widely in both gray and white matter of aged dogs, while they were very small in number in young dogs. Swollen neurites-like materials in primitive plaques or classical plaques were immunoreactive for anti-ubiquitin serum. Tau immunostaining labeled commonly axons and several neuronal or glial cells after hydrate autoclave pretreatment. Tau-positive components were observed very rarely in the corona of classical plaques. Most of swollen neurites-like structures of primitive or classical plaques were not reactive for anti-NF serum, and only a few plaques contained small numbers of NF-positive elements.

  2. Railways and asbestos in Japan (1928-1987)--epidemiology of pleural plaques, malignancies and pneumoconioses-.

    PubMed

    Hosoda, Yutaka; Hiraga, Youmei; Sasagawa, Sumiko

    2008-01-01

    Asbestos has been an indispensable insulating material for railway industries, especially steam locomotives (SLs). This review (1928-1987) consists of three parts. 1) Pleural plaques: Since the 1970s, pleural plaques have been regarded as evidence of past asbestos inhalation, and more recently recognized as a risk factor of asbestos-related malignancies. For diagnostic criteria on plain radiographs, the modified ILO 1980 International Classification of Radiographs of Pneumoconioses was used. Most cases had pleural plaques with normal lungs. Large plant workers showed a significantly higher rate of plaques than workers in smaller plants. Bilateral plaques were dominant followed by the left, then the right lung, and chest wall plaques were dominant over the diaphragm. The manifestation of pleural plaques was more correlated to years since the onset of the asbestos exposure than the sum of asbestos work years, although the result was not significant. The boilermen of railway ferry steamers had a significantly higher plaque rate than other seamen. CT studies on plaques started in 1978. 2) Asbestos-related malignancies: Five retrospective cohort studies 1960-1970 were made on primary lung cancer incidence and mortality among 350,000 active railway men with smoking information. The follow-up period was 20 yr at the longest. Almost all plant workers showed a tendency of higher incidence or mortality than the controls. Two cases of mesothelioma were reported in 1980. 3) Pneumoconioses: Most studies (1928-1975) had relatively low prevalence rates among SL-related workers.

  3. Comparison of strain rates of dart impacted plaques and pendulum impacted bumpers

    SciTech Connect

    Scammell, K.L.

    1987-01-01

    The difference in strain rates prevailing during pendulum impact of bumpers versus high speed dart impact of plaques was investigated. Uni-axial strain gages were applied to the tension side of the plaques and bumpers directly opposite the point of impact. The plaques were impacted with an instrumented high rate dart impact tester and the bumpers impacted with a full scale bumper pendulum impact tester. Theoretical calculations and actual strain rate data support the conclusion that the strain rate of a plaque during dart impact significantly exceeds that of bumper strain rate during pendulum impact.

  4. Neuritic Plaques and Cerebrovascular Amyloid in Alzheimer Disease are Antigenically Related

    NASA Astrophysics Data System (ADS)

    Wong, Caine W.; Quaranta, Vito; Glenner, George G.

    1985-12-01

    A synthetic peptide (Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr), homologous to the amino terminus of a protein purified from cerebrovascular amyloid (β protein), induced antibodies in BALB/c mice that were used immunohistochemically to stain not only amyloid-laden cerebral vessels but neuritic plaques as well. These findings suggest that the amyloid in neuritic plaques shares antigenic determinants with β protein of cerebral vessels. Since the amino acid compositions of plaque amyloid and cerebrovascular amyloid are similar, it is likely that plaque amyloid also consists of β protein. This possibility suggests a model for the pathogenesis of Alzheimer disease involving β protein.

  5. Iron plaque decreases cadmium accumulation in Oryza sativa L. and serves as a source of iron.

    PubMed

    Sebastian, A; Prasad, M N V

    2016-11-01

    Cadmium (Cd) contamination occurs in paddy soils; hence it is necessary to reduce Cd content of rice. Application and mode of action of ferrous sulphate in minimizing Cd in rice was monitored in the present study. Pot culture with Indian rice variety Swarna (MTU 7029) was maintained in Cd-spiked soil containing ferrous sulphates, which is expected to reduce Cd accumulation in rice. Responses in rhizosphere pH, root surface, metal accumulation in plant and molecular physiological processes were monitored. Iron plaque was induced on root surfaces after FeSO4 application and the amount of Fe in plaque reduced with increases in Cd in the soil. Rhizosphere pH decreased during plaque formation and became more acidic due to secretion of organic acids from the roots under Cd treatment. Moreover, iron chelate reductase activity increased with Cd treatment, but in the absence of Cd, activity of this enzyme increased in plaque-induced plants. Cd treatment caused expression of OsYSL18, whereas OsYSL15 was expressed only in roots without iron plaque. Fe content of plants increased during plaque formation, which protected plants from Cd-induced Fe deficiency and metal toxicity. This was corroborated with increased biomass, chlorophyll content and quantum efficiency of photo-synthesis among plaque-induced plants. We conclude that ferrous sulphate-induced iron plaque prevents Cd accumulation and Fe deficiency in rice. Iron released from plaque via organic acid mediated dissolution during Cd stress.

  6. On numerically accurate finite element

    NASA Technical Reports Server (NTRS)

    Nagtegaal, J. C.; Parks, D. M.; Rice, J. R.

    1974-01-01

    A general criterion for testing a mesh with topologically similar repeat units is given, and the analysis shows that only a few conventional element types and arrangements are, or can be made suitable for computations in the fully plastic range. Further, a new variational principle, which can easily and simply be incorporated into an existing finite element program, is presented. This allows accurate computations to be made even for element designs that would not normally be suitable. Numerical results are given for three plane strain problems, namely pure bending of a beam, a thick-walled tube under pressure, and a deep double edge cracked tensile specimen. The effects of various element designs and of the new variational procedure are illustrated. Elastic-plastic computation at finite strain are discussed.

  7. Serum Osteoprotegerin Is Associated With Calcified Carotid Plaque

    PubMed Central

    Kwon, Ami; Choi, Yun-Seok; Choi, Yong-Won; Chung, Woo-Baek; Park, Chul-Soo; Chung, Wook-Sung; Lee, Man-Young; Youn, Ho-Joong

    2016-01-01

    Abstract Osteoprotegerin (OPG) is a kind of tumor necrosis factor, which is related to bone metabolism and vascular calcification. The increase of Osteoprotegerin concentration in serum is related to cardiovascular diseases in humans. The purpose of this study was to figure out the relevance between osteoprotegerin in serum and carotid calcification. Serum OPG concentrations were compared in 145 patients who underwent carotid sonography (average age: 68 ± 9 years old, male: female = 81:64). A calcified plaque (CP) (37 people [27%]), a noncalcified plaque (NCP) (54 people [37%]), and a nonplaque (NP) (54 people [37%]) were classified for this study. No significant differences among 3 groups were demonstrated in the distribution of age, diabetes, high blood pressure, and hyperlipidemia. Serum osteoprotegerin concentrations were significantly increased in CP group rather than NCP group or NP group; (median [interquartile range], 4016 [1410] vs 3210 [1802] pg/mL, P < 0.05 and 4016 [1410] vs 3204 [1754] pg/mL, P < 0.05). Serum osteoprotegerin concentrations did not indicate a significant difference between NCP Group or NP Group. This study had proved that patient group accompanied with carotid calcification in carotid artery disease had an increased serum OPG concentration, so it could consider that OPG plays an important function on calcification related to arteriosclerosis. PMID:27082605

  8. Performance of digital RGB reflectance color extraction for plaque lesion

    NASA Astrophysics Data System (ADS)

    Hashim, Hadzli; Taib, Mohd Nasir; Jailani, Rozita; Sulaiman, Saadiah; Baba, Roshidah

    2005-01-01

    Several clinical psoriasis lesion groups are been studied for digital RGB color features extraction. Previous works have used samples size that included all the outliers lying beyond the standard deviation factors from the peak histograms. This paper described the statistical performances of the RGB model with and without removing these outliers. Plaque lesion is experimented with other types of psoriasis. The statistical tests are compared with respect to three samples size; the original 90 samples, the first size reduction by removing outliers from 2 standard deviation distances (2SD) and the second size reduction by removing outliers from 1 standard deviation distance (1SD). Quantification of data images through the normal/direct and differential of the conventional reflectance method is considered. Results performances are concluded by observing the error plots with 95% confidence interval and findings of the inference T-tests applied. The statistical tests outcomes have shown that B component for conventional differential method can be used to distinctively classify plaque from the other psoriasis groups in consistent with the error plots finding with an improvement in p-value greater than 0.5.

  9. Quantification of plaque stiffness by Brillouin microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Antonacci, Giuseppe; Pedrigi, Ryan; Krams, Rob; Török, Peter

    2016-03-01

    Spontaneous Brillouin scattering is an inelastic scattering process arising from inherent thermal density fluctuations, or acoustic phonons, propagating in a medium. Over the last few years, Brillouin spectroscopy has shown great potential to become a reliable non-invasive diagnostic tool due to its unique capability of retrieving viscoelastic properties of materials such as strain and stiffness. The detection of the weak scattered light, in addition to the resolution of the Brillouin peaks (typically shifted by few GHz from the central peak) represent one of the greatest challenges in Brillouin. The recent development of high sensitivity CCD cameras has brought Brillouin spectroscopy from a point sampling technique to a new imaging modality. Furthermore, the application of Virtually Imaged Phased Array (VIPA) etalons has dramatically reduced insertion loss simultaneously allowing fast (<1s) collection of the entire spectrum. Hitherto Brillouin microscopy has been shown the ability to provide unique stiffness maps of biological samples, such as the human lens, in a non-destructive manner. In this work, we present results obtained using our Brillouin microscope to map the stiffness variations in the walls of blood vessels in particular when atherosclerotic plaques are formed. The stiffness of the membrane that covers the plaques is critical in developing acute myocardial infarction yet it is not currently possible to credibly assess its stiffness due to lack of suitable methods.

  10. Periapical bacterial plaque in teeth refractory to endodontic treatment.

    PubMed

    Tronstad, L; Barnett, F; Cervone, F

    1990-04-01

    It has recently been found that bacteria are able to survive and maintain an infectious disease process in periapical lesions of nonvital teeth. The purpose of this study was to examine the surfaces of root tips removed during surgical-endodontic treatment for the presence of microorganisms. A full thickness flap was reflected under strict surgical asepsis and the periapical lesions were enucleated and removed. About 2-3 mm of the root was cut off, rinsed in sterile saline and placed in 10% neutral-buffered formalin. Upon fixation, the root tips were dehydrated, air-dried and given an electrically conducting coat of gold in a vacuum evaporator. The root tips were then studied in a Jeol, JSM-U3 scanning electron microscope, usually operated at 20 kV. The root surfaces were covered with soft tissue, except at the apex of the roots, where a continuous, smooth and structureless coating was seen, apparently adjacent to the apical foramen. At higher magnification a variety of bacterial forms were recognized in the smooth coating. A bacterial plaque was observed in irregularities of the surfaces between fiber bundles and cells and in crypts and holes. The bacteria were held together by an extracellular material and the plaque was dominated by cocci and rods. Fibrillar forms were recognized as well, often with cocci attached to their surfaces.

  11. Computerized flow and vessel wall analyses of coronary arteries for detection of non-calcified plaques in coronary CT angiography

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    The buildup of non-calcified plaques (NCP) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. We are developing a computer-aided detection (CADe) system to assist radiologists in detecting NCPs in cCTA. A major challenge of NCP detection is the large number of false positives (FPs) caused by the small sized coronary arteries, image noise and artifacts. In this study, our purpose is to design new image features to reduce FPs. A data set of 98 cCTA scans was retrospectively collected from patient files. We first used vessel wall analysis, in which topological features were extracted from vessel wall and fused with a support-vector machine, to identify the NCP candidates from the segmented coronary tree. Computerized flow dynamic (CFD) features that characterize the change in blood flow due to the presence of plaques and a vascular cross-sectional (VCS) feature that quantifies the presence of low attenuation region at the vessel wall were designed for FP reduction. Using a leave-one-out resampling method, a support vector machine classifier was trained to merge the features into a NCP likelihood score using the vessel wall features alone or in combination with the new CDF and VCS features. The performance of the new features in classification of true NCPs and FPs was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC). Without the new CFD and VCS features, the test AUC was 0.84+/-0.01. The AUC was improved to 0.88+/-0.01 with the addition of the new features. The improvement was statistically significant (p < 0.001). The study indicated that the new flow dynamic and vascular cross-sectional features were useful for differentiation of NCPs from FPs in cCTA.

  12. Groundwater vulnerability mapping of Qatar aquifers

    NASA Astrophysics Data System (ADS)

    Baalousha, Husam Musa

    2016-12-01

    Qatar is one of the most arid countries in the world with limited water resources. With little rainfall and no surface water, groundwater is the only natural source of fresh water in the country. Whilst the country relies mainly on desalination of seawater to secure water supply, groundwater has extensively been used for irrigation over the last three decades, which caused adverse environmental impact. Vulnerability assessment is a widely used tool for groundwater protection and land-use management. Aquifers in Qatar are carbonate with lots of fractures, depressions and cavities. Karst aquifers are generally more vulnerable to contamination than other aquifers as any anthropogenic-sourced contaminant, especially above a highly fractured zone, can infiltrate quickly into the aquifer and spread over a wide area. The vulnerability assessment method presented in this study is based on two approaches: DRASTIC and EPIK, within the framework of Geographical Information System (GIS). Results of this study show that DRASTIC vulnerability method suits Qatar hydrogeological settings more than EPIK. The produced vulnerability map using DRASTIC shows coastal and karst areas have the highest vulnerability class. The southern part of the country is located in the low vulnerability class due to occurrence of shale formation within aquifer media, which averts downward movement of contaminants.

  13. Vulnerability, Health Agency and Capability to Health.

    PubMed

    Straehle, Christine

    2016-01-01

    One of the defining features of the capability approach (CA) to health, as developed in Venkatapuram's book Health Justice, is its aim to enable individual health agency. Furthermore, the CA to health hopes to provide a strong guideline for assessing the health-enabling content of social and political conditions. In this article, I employ the recent literature on the liberal concept of vulnerability to assess the CA. I distinguish two kinds of vulnerability. Considering circumstantial vulnerability, I argue that liberal accounts of vulnerability concerned with individual autonomy, align with the CA to health. Individuals should, as far as possible, be able to make health-enabling decisions about their lives, and their capability to do so should certainly not be hindered by public policy. The CA to health and a vulnerability-based analysis then work alongside to define moral responsibilities and designate those who hold them. Both approaches demand social policy to address circumstances that hinder individuals from taking health-enabling decisions. A background condition of vulnerability, on the other hand, even though it hampers the capability for health, does not warrant the strong moral claim proposed by the CA to health to define health as a meta-capability that should guide social policy. Nothing in our designing social policy could change the challenge to health agency when we deal with background conditions of vulnerability.

  14. Modified COMS Plaques for {sup 125}I and {sup 103}Pd Iris Melanoma Brachytherapy

    SciTech Connect

    Thomson, Rowan M.; Furutani, Keith M.; Pulido, Jose S.; Stafford, Scott L.; Rogers, D.W.O.

    2010-11-15

    Purpose: Novel plaques are used to treat iris melanoma at the Mayo Clinic Rochester. The plaques are a modification of the Collaborative Ocular Melanoma Study (COMS) 22 mm plaque design with a gold alloy backing, outer lip, and silicone polymer insert. An inner lip surrounds a 10 mm diameter cutout region at the plaque center. Plaques span 360{sup o}, 270{sup o}, and 180{sup o} arcs. This article describes dosimetry for these plaques and others used in the treatment of anterior eye melanomas. Methods and Materials: The EGSnrc user-code BrachyDose is used to perform Monte Carlo simulations. Plaques and seeds are fully modeled. Three-dimensional dose distributions for different plaque models, TG-43 calculations, and {sup 125}I (model 6711) and {sup 103}Pd (model 200) seeds are compared via depth-dose curves, tabulation of doses at points of interest, and isodose contours. Results: Doses at points of interest differ by up to 70% from TG-43 calculations. The inner lip reduces corneal doses. Matching plaque arc length to tumor extent reduces doses to eye regions outside the treatment area. Maintaining the same prescription dose, {sup 103}Pd offers lower doses to critical structures than {sup 125}I, with the exception of the sclera adjacent to the plaque. Conclusion: The Mayo Clinic plaques offer several advantages for anterior eye tumor treatments. Doses to regions outside the treatment area are significantly reduced. Doses differ considerably from TG-43 predictions, illustrating the importance of complete Monte Carlo simulations. Calculations take a few minutes on a single CPU, making BrachyDose sufficiently fast for routine clinical treatment planning.

  15. Vulnerability indicators of sea water intrusion.

    PubMed

    Werner, Adrian D; Ward, James D; Morgan, Leanne K; Simmons, Craig T; Robinson, Neville I; Teubner, Michael D

    2012-01-01

    In this paper, simple indicators of the propensity for sea water intrusion (SWI) to occur (referred to as "SWI vulnerability indicators") are devised. The analysis is based on an existing analytical solution for the steady-state position of a sharp fresh water-salt water interface. Interface characteristics, that is, the wedge toe location and sea water volume, are used in quantifying SWI in both confined and unconfined aquifers. Rates-of-change (partial derivatives of the analytical solution) in the wedge toe or sea water volume are used to quantify the aquifer vulnerability to various stress situations, including (1) sea-level rise; (2) change in recharge (e.g., due to climate change); and (3) change in seaward discharge. A selection of coastal aquifer cases is used to apply the SWI vulnerability indicators, and the proposed methodology produces interpretations of SWI vulnerability that are broadly consistent with more comprehensive investigations. Several inferences regarding SWI vulnerability arise from the analysis, including: (1) sea-level rise impacts are more extensive in aquifers with head-controlled rather than flux-controlled inland boundaries, whereas the opposite is true for recharge change impacts; (2) sea-level rise does not induce SWI in constant-discharge confined aquifers; (3) SWI vulnerability varies depending on the causal factor, and therefore vulnerability composites are needed that differentiate vulnerability to such threats as sea-level rise, climate change, and changes in seaward groundwater discharge. We contend that the approach is an improvement over existing methods for characterizing SWI vulnerability, because the method has theoretical underpinnings and yet calculations are simple, although the coastal aquifer conceptualization is highly idealized.

  16. Determining Vulnerability Importance in Environmental Impact Assessment

    SciTech Connect

    Toro, Javier; Duarte, Oscar; Requena, Ignacio; Zamorano, Montserrat

    2012-01-15

    The concept of vulnerability has been used to describe the susceptibility of physical, biotic, and social systems to harm or hazard. In this sense, it is a tool that reduces the uncertainties of Environmental Impact Assessment (EIA) since it does not depend exclusively on the value assessments of the evaluator, but rather is based on the environmental state indicators of the site where the projects or activities are being carried out. The concept of vulnerability thus reduces the possibility that evaluators will subjectively interpret results, and be influenced by outside interests and pressures during projects. However, up until now, EIA has been hindered by a lack of effective methods. This research study analyzes the concept of vulnerability, defines Vulnerability Importance and proposes its inclusion in qualitative EIA methodology. The method used to quantify Vulnerability Importance is based on a set of environmental factors and indicators that provide a comprehensive overview of the environmental state. The results obtained in Colombia highlight the usefulness and objectivity of this method since there is a direct relation between this value and the environmental state of the departments analyzed. - Research Highlights: Black-Right-Pointing-Pointer The concept of vulnerability could be considered defining Vulnerability Importance included in qualitative EIA methodology. Black-Right-Pointing-Pointer The use of the concept of environmental vulnerability could reduce the subjectivity of qualitative methods of EIA. Black-Right-Pointing-Pointer A method to quantify the Vulnerability Importance proposed provides a comprehensive overview of the environmental state. Black-Right-Pointing-Pointer Results in Colombia highlight the usefulness and objectivity of this method.

  17. Accurate ab Initio Spin Densities.

    PubMed

    Boguslawski, Katharina; Marti, Konrad H; Legeza, Ors; Reiher, Markus

    2012-06-12

    We present an approach for the calculation of spin density distributions for molecules that require very large active spaces for a qualitatively correct description of their electronic structure. Our approach is based on the density-matrix renormalization group (DMRG) algorithm to calculate the spin density matrix elements as a basic quantity for the spatially resolved spin density distribution. The spin density matrix elements are directly determined from the second-quantized elementary operators optimized by the DMRG algorithm. As an analytic convergence criterion for the spin density distribution, we employ our recently developed sampling-reconstruction scheme [J. Chem. Phys.2011, 134, 224101] to build an accurate complete-active-space configuration-interaction (CASCI) wave function from the optimized matrix product states. The spin density matrix elements can then also be determined as an expectation value employing the reconstructed wave function expansion. Furthermore, the explicit reconstruction of a CASCI-type wave function provides insight into chemically interesting features of the molecule under study such as the distribution of α and β electrons in terms of Slater determinants, CI coefficients, and natural orbitals. The methodology is applied to an iron nitrosyl complex which we have identified as a challenging system for standard approaches [J. Chem. Theory Comput.2011, 7, 2740].

  18. Bacterial Amyloid and DNA are Important Constituents of Senile Plaques: Further Evidence of the Spirochetal and Biofilm Nature of Senile Plaques

    PubMed Central

    Miklossy, Judith

    2016-01-01

    It has long been known that spirochetes form clumps or micro colonies in vitro and in vivo. Cortical spirochetal colonies in syphilitic dementia were considered as reproductive centers for spirochetes. Historic and recent data demonstrate that senile plaques in Alzheimer’s disease (AD) are made up by spirochetes. Spirochetes, are able to form biofilm in vitro. Senile plaques are also reported to contain elements of biofilm constituents. We expected that AβPP and Aβ (the main components of senile plaques) also occur in pure spirochetal biofilms, and bacterial DNA (an important component of biofilm) is also present in senile plaques. Histochemical, immunohistochemical, and in situ hybridization techniques and the TUNEL assay were used to answer these questions. The results obtained demonstrate that Aβ and DNA, including spirochete-specific DNA, are key components of both pure spirochetal biofilms and senile plaques in AD and confirm the biofilm nature of senile plaques. These results validate validate previous observations that AβPP and/or an AβPP-like amyloidogenic protein are an integral part of spirochetes, and indicate that bacterial and host derived Aβ are both constituents of senile plaques. DNA fragmentation in senile plaques further confirms their bacterial nature and provides biochemical evidence for spirochetal cell death. Spirochetes evade host defenses, locate intracellularly, form more resistant atypical forms and notably biofilms, which contribute to sustain chronic infection and inflammation and explain the slowly progressive course of dementia in AD. To consider co-infecting microorganisms is equally important, as multi-species biofilms result in a higher resistance to treatments and a more severe dementia. PMID:27314530

  19. Papular angiolymphoid hyperplasia and lymphoplasmacytic plaque: a clinical and histological spectrum.

    PubMed

    Yeo, Y W; Oon, H H; Lee, J S; Pan, J Y; Mok, Y J; Ng, S K

    2016-04-18

    Acral pseudolymphomatous angiokeratoma of children (APACHE) is a rare form of cutaneous pseudolymphoma characterized byangiomatous papules with a predilection for the acral regions of children. Classically, a dense dermal lymphocytic infiltrate composed of both T and B cells is seen in histological specimens, together with prominent vessels lined by plump endothelial cells. Increasing evidence suggests that this condition is neither necessarily acral, pseudolymphomatous, nor angiokeratomatous. It may not always be a pediatric disease. Therefore, the correctness of its nomenclature has been questioned. Herein, we report threecases whose clinical and histological features were consistent with the diagnosis of APACHE. To our knowledge, this is the first report of APACHE from Southeast Asia. We also discuss why we believe "APACHE" to be a misnomer and support "papular angiolymphoid hyperplasia" as a more accurate and encompassing term. In addition, we illustrate a case with significant overlapping features with lymphoplasmacytic plaque in children, suggesting that both entities may exist on a clinical andhistological spectrum.

  20. Prevalence and risk factors for atherosclerotic carotid stenosis and plaque

    PubMed Central

    Woo, Shin Young; Joh, Jin Hyun; Han, Sang-Ah; Park, Ho-Chul

    2017-01-01

    Abstract Atherosclerotic carotid stenosis (ACS) is a major cause of ischemic stroke. Screening for asymptomatic ACS is important to identify the patients who require longitudinal surveillance, medication, or endovascular surgery. The aim of this study was to assess the prevalence and risk factors for ACS and carotid plaque (CP) in Korea using a population-based screening study. We recruited participants during visits to several community welfare centers in Korea. The baseline characteristics of the study population were collected. All patients underwent duplex ultrasonography to examine their bilateral carotid arteries. ACS was defined as the presence of plaque with ≥50% vessel diameter reduction and peak systolic velocity (PSV) ≥125 cm/s or PSV ratio ≥2.0. CP was defined as the presence of plaque with <50% vessel diameter reduction. The Mann–Whitney test, χ2 test, Fisher exact test, and logistic regression were used in the statistical analysis. A total of 3030 participants were enrolled in this study (male 43.7% and female 56.3%). The prevalence of ACS and CP was 1.1% and 5.7%, respectively. Significant risk factors for CP included age ≥80 years (odds ratio [OR], 8.11; 95% confidence interval [CI], 3.45–18.93), male sex (OR, 2.16; 95% CI, 1.29–3.61), hypertension (OR, 1.72; 95% CI, 1.21–2.45), and hyperlipidemia (OR, 1.84; 95% CI, 1.30–2.62). The presence of ACS was significantly associated with age (OR, 1.07; 95% CI, 1.03–1.12), hypertension (OR, 3.16; 95% CI, 1.34–7.46), and being an ex-smoker (OR, 6.81; 95% CI, 1.66–27.93) or current smoker (OR, 6.97; 95% CI, 1.78–27.31) after adjusting for confounding factors. This population-based screening study revealed that ACS was uncommon and had a prevalence of 1.1% in the study population. Age, hypertension, and smoking were risk factors for ACS. Further investigations into the prevalence and risk factors of ACS are required, as are studies on the cost-effectiveness of a national screening

  1. Connexin Type and Fluorescent Protein Fusion Tag Determine Structural Stability of Gap Junction Plaques*

    PubMed Central

    Stout, Randy F.; Snapp, Erik Lee; Spray, David C.

    2015-01-01

    Gap junctions (GJs) are made up of plaques of laterally clustered intercellular channels and the membranes in which the channels are embedded. Arrangement of channels within a plaque determines subcellular distribution of connexin binding partners and sites of intercellular signaling. Here, we report the discovery that some connexin types form plaque structures with strikingly different degrees of fluidity in the arrangement of the GJ channel subcomponents of the GJ plaque. We uncovered this property of GJs by applying fluorescence recovery after photobleaching to GJs formed from connexins fused with fluorescent protein tags. We found that connexin 26 (Cx26) and Cx30 GJs readily diffuse within the plaque structures, whereas Cx43 GJs remain persistently immobile for more than 2 min after bleaching. The cytoplasmic C terminus of Cx43 was required for stability of Cx43 plaque arrangement. We provide evidence that these qualitative differences in GJ arrangement stability reflect endogenous characteristics, with the caveat that the sizes of the GJs examined were necessarily large for these measurements. We also uncovered an unrecognized effect of non-monomerized fluorescent protein on the dynamically arranged GJs and the organization of plaques composed of multiple connexin types. Together, these findings redefine our understanding of the GJ plaque structure and should be considered in future studies using fluorescent protein tags to probe dynamics of highly ordered protein complexes. PMID:26265468

  2. 21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872.5580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... devices that act by reducing the attachment and inhibiting the growth of bacterial plaque....

  3. 21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872.5580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... devices that act by reducing the attachment and inhibiting the growth of bacterial plaque....

  4. Mechanical modeling of cholesterol crystallization in atherosclerotic plaques base on Micro-OCT images (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Luo, Yuemei; Liu, Xinyu; Chen, Si; Cui, Dongyao; Wang, Xianghong; Liu, Linbo

    2016-02-01

    Plaque rupture is the critical cause of cardiovascular thrombosis but this process is still under discussion. Recent studies show that, during crystallization, cholesterol crystals in atheromatous plaques accumulate rapidly in a limited space and may result in plaque rupture. However, the actual role of cholesterol crystals on plaque rupture remains unclear due to the lack of detailed morphological information of cholesterol crystals. In this study, we used a Micro-optical coherence tomography (µOCT) setup with 1-2 µm spatial resolution to extract the geometry of cholesterol crystals from human atherosclerotic artery ex vivo firstly. With measured dimensions of cholesterol crystals by this µOCT system (the average length and thickness of 269.1±80.16 µm and 3.0±0.33 µm), we developed a two-dimensional mechanical model in which rectangular shaped cholesterol crystals distribute at different locations spatially. We predicted the stress on the thin cap induced by the expansion of cholesterol crystals by use of finite-element method. Since a large portion of plaques (58%) rupture at points of peak circumferential stress (PCS), we used PCS as the primary indicator of plaque stability with blood pressure of 14.6 kPa on the lumen. The results demonstrate that loading of the concentrated crystals especially at the cap shoulder destabilize the plaque by proportionally increasing the PCS, while evenly distributed crystals loading along the cap might impose less PCS to the plaque than the concentrated case.

  5. Effects of mouth rinses with xylitol and fluoride on dental plaque and saliva.

    PubMed

    Giertsen, E; Emberland, H; Scheie, A A

    1999-01-01

    The aim of this study was to test the hypothesis that xylitol, alone and in combination with fluoride, affects the salivary flow rate and micro-biota, dental plaque accumulation, gingivitis development, and the acidogenic potential of plaque. Three groups, each of 10 subjects, rinsed for 1 min 3 times daily over two 4-week periods, first with 10 ml water (control), and thereafter with either 0.05% NaF, 40% xylitol, or with 0.025% NaF plus 20% xylitol according to a double-blind controlled design. They performed habitual mechanical tooth cleaning during the first 2 weeks of each period but abstained from interdental cleaning during the final 2 weeks. While mouth rinsing was continued, all mechanical oral hygiene was discontinued the last 2 days of each period to permit plaque accumulation. The last mouth rinse was administered in the clinic before the final examination. The following parameters were assessed: (1) unstimulated and paraffin-stimulated salivary secretion rates; (2) salivary micro-biota; (3) plaque index; (4) papillar bleeding; (5) plaque pH response to sucrose, and (6) lactate formation by dental plaque. No statistically significant differences in any of the parameters were found. In conclusion, three daily mouth rinses with fluoride and xylitol, separately or in combination, did not affect the salivary flow rate or micro-biota, dental plaque accumulation, gingivitis development, or the acidogenic potential of plaque.

  6. Amino acid composition and amino acid-metabolic network in supragingival plaque.

    PubMed

    Washio, Jumpei; Ogawa, Tamaki; Suzuki, Keisuke; Tsukiboshi, Yosuke; Watanabe, Motohiro; Takahashi, Nobuhiro

    2016-01-01

    Dental plaque metabolizes both carbohydrates and amino acids. The former can be degraded to acids mainly, while the latter can be degraded to various metabolites, including ammonia, acids and amines, and associated with acid-neutralization, oral malodor and tissue inflammation. However, amino acid metabolism in dental plaque is still unclear. This study aimed to elucidate what kinds of amino acids are available as metabolic substrates and how the amino acids are metabolized in supragingival plaque, by a metabolome analysis. Amino acids and the related metabolites in supragingival plaque were extracted and quantified comprehensively by CE-TOFMS. Plaque samples were also incubated with amino acids, and the amounts of ammonia and amino acid-related metabolites were measured. The concentration of glutamate was the highest in supragingival plaque, while the ammonia-production was the highest from glutamine. The obtained metabolome profile revealed that amino acids are degraded through various metabolic pathways, including deamination, decarboxylation and transamination and that these metabolic systems may link each other, as well as with carbohydrate metabolic pathways in dental plaque ecosystem. Moreover, glutamine and glutamate might be the main source of ammonia production, as well as arginine, and contribute to pH-homeostasis and counteraction to acid-induced demineralization in supragingival plaque.

  7. Early Detection of Amyloid Plaque in Alzheimer’s Disease via X-Ray Phase CT

    DTIC Science & Technology

    2014-06-01

    DATES COVERED 15 May 2013 - 14 May 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Early Detection of Amyloid Plaque in Alzheimer’s Disease via...SUPPLEMENTARY NOTES 14. ABSTRACT In this project, we proposed to develop the imaging method for early detection of amyloid plaque in Alzheimer’s

  8. Comparison of methods for monitoring changes in the pH of human dental plaque.

    PubMed

    Schachtele, C F; Jensen, M E

    1982-10-01

    Changes in human dental plaque pH can be used to obtain estimates of the acidogenic potential of ingested foods. The presence of acid in plaque is influenced by a large number of host, microbial, and substrate factors. Several useful methods have been developed for monitoring changes in plaque pH. Plaque sampling involves repeated removal of small samples of plaque from a number of teeth at intervals after food ingestion, dispersion of the sample, and in vitro measurement of pH. Touch electrode methods utilize glass or antimony microelectrodes, which are placed onto plaque in situ where direct readings can be obtained. Telemetry methods involve placement of glass microelectrodes or ion-sensitive field effect transistors within the dentition. Plaque is allowed to accumulate, and pH changes can subsequently be transmitted with radio or wire. Each of the methods has clear advantages and limitations. The methods have been simultaneously compared in human volunteers using solutions of fermentable carbohydrate. Inter-method differences in response were observed depending upon the site of measurement. Data obtained from caries-prone surfaces via telemetry showed lower pH minima and retarded returns to resting pH levels. The technology is available for controlled comparative plaque pH studies, with the method of choice depending upon the goals of the investigation. It is essential that the results be compared to data obtained with other models designed to evaluate the cariogenic potential of foods.

  9. Early Detection of Amyloid Plaque in Alzheimer’s Disease Via X-ray Phase CT

    DTIC Science & Technology

    2015-06-01

    SUBTITLE 5a. CONTRACT NUMBER W81XWH-12-1-0138 Early Detection of Amyloid Plaque in Alzheimer’s Disease Via X-ray Phase CT 5b. GRANT NUMBER 5c...ray phase contrast CT imaging method for early detection of amyloid plaque in Alzheimer’s disease. As specified in SA#1 and the project timeline, the

  10. Automatic segmentation of amyloid plaques in MR images using unsupervised support vector machines.

    PubMed

    Iordanescu, Gheorghe; Venkatasubramanian, Palamadai N; Wyrwicz, Alice M

    2012-06-01

    Deposition of the β-amyloid peptide (Aβ) is an important pathological hallmark of Alzheimer's disease (AD). However, reliable quantification of amyloid plaques in both human and animal brains remains a challenge. We present here a novel automatic plaque segmentation algorithm based on the intrinsic MR signal characteristics of plaques. This algorithm identifies plaque candidates in MR data by using watershed transform, which extracts regions with low intensities completely surrounded by higher intensity neighbors. These candidates are classified as plaque or nonplaque by an unsupervised learning method using features derived from the MR data intensity. The algorithm performance is validated by comparison with histology. We also demonstrate the algorithm's ability to detect age-related changes in plaque load ex vivo in amyloid precursor protein (APP) transgenic mice that coexpress five familial AD mutations (5xFAD mice). To our knowledge, this study represents the first quantitative method for characterizing amyloid plaques in MRI data. The proposed method can be used to describe the spatiotemporal progression of amyloid deposition, which is necessary for understanding the evolution of plaque pathology in mouse models of Alzheimer's disease and to evaluate the efficacy of emergent amyloid-targeting therapies in preclinical trials.

  11. 21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872.5580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... bacterial plaque on teeth and oral mucosal surfaces by physical means. The device type includes...

  12. 21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872.5580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... bacterial plaque on teeth and oral mucosal surfaces by physical means. The device type includes...

  13. Novel Papillomaviral Sequence Detected within Epidermal Plaques in a Wolf (Canis lupus).

    PubMed

    Rothenburger, Jamie L; Myers, Sherry; Lockerbie, Betty; Wobeser, Bruce

    2016-01-01

    We describe numerous pale plaques affecting the inguinal skin of a grey wolf (Canis lupus). Histologically, these were consistent with papillomaviral plaques. Immunohistochemistry confirmed papillomavirus antigens, and partial sequencing of the L1 gene suggests this is a novel papillomavirus most-closely related to Canis familiaris Papillomavirus 5.

  14. Lysophosphatidic acid triggers mast cell-driven atherosclerotic plaque destabilization by increasing vascular inflammation.

    PubMed

    Bot, Martine; de Jager, Saskia C A; MacAleese, Luke; Lagraauw, H Maxime; van Berkel, Theo J C; Quax, Paul H A; Kuiper, Johan; Heeren, Ron M A; Biessen, Erik A L; Bot, Ilze

    2013-05-01

    Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by modulating mast cell function. We here show by an imaging mass spectrometry approach that several LPA species are present in atherosclerotic plaques. Subsequently, we demonstrate that LPA is a potent mast cell activator which, unlike other triggers, favors release of tryptase. Local perivascular administration of LPA to an atherosclerotic carotid artery segment increases the activation status of perivascular mast cells and promotes intraplaque hemorrhage and macrophage recruitment without impacting plaque cell apoptosis. The mast cell stabilizer cromolyn could prevent intraplaque hemorrhage elicited by LPA-mediated mast cell activation. Finally, the involvement of mast cells in these events was further emphasized by the lack of effect of perivascular LPA administration in mast cell deficient animals. We demonstrate that increased accumulation of LPA in plaques induces perivascular mast cell activation and in this way contributes to plaque destabilization in vivo. This study points to local LPA availability as an important factor in atherosclerotic plaque stability.

  15. [Aged woman's vulnerability related to AIDS].

    PubMed

    Silva, Carla Marins; Lopes, Fernanda Maria do Valle Martins; Vargens, Octavio Muniz da Costa

    2010-09-01

    This article is a systhematic literature review including the period from 1994 to 2009, whose objective was to discuss the aged woman's vulnerability in relation to Acquired Imunodeficiency Syndrome (Aids). The search for scientific texts was accomplished in the following databases: Biblioteca Virtual em Saúde, Scientific Eletronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) and Medical Literature Analysis and Retrieval System Online (MEDLINE). The descriptors used were vulnerability, woman and Aids. Eighteen texts were analyzed, including articles in scientific journals, thesis and dissertations. As a conclusion, it was noted that aged women and vulnerability to Aids are directly related, through gender characteristics including submission and that were built historical and socially. We consider as fundamental the development of studies which may generate publications accessible to women, in order to help them see themselves as persons vulnerable to Aids contagion just for being women.

  16. Vulnerable Zone Indicator System (Option 2)

    EPA Pesticide Factsheets

    Enter your latitude and longitude to access the Vulnerable Zone Indicator System. VZIS can help you determine if your area could be affected by a chemical accident at a facility that submitted a Risk Management Plan (RMP).

  17. Salt vulnerability assessment methodology for urban streams

    NASA Astrophysics Data System (ADS)

    Betts, A. R.; Gharabaghi, B.; McBean, E. A.

    2014-09-01

    De-icing agents such as road salts while used for winter road maintenance can cause negative effects on urban stream water quality and drinking water supplies. A new methodology using readily available spatial data to identify Salt Vulnerable Areas (SVAs) for urban streams is used to prioritize implementation of best management practices. The methodology calculates the probable chloride concentration statistics at specified points in the urban stream network and compares the results with known aquatic species exposure tolerance limits to characterize the vulnerability scores. The approach prioritizes implementation of best management practices to areas identified as vulnerable to road salt. The vulnerability assessment is performed on seven sites in four watersheds in the Greater Toronto Area and validated using the Hanlon Creek watershed in Guelph. The mean annual in-stream chloride concentration equation uses readily available spatial data - with province-wide coverage - that can be easily used in any urban watershed.

  18. Extinction vulnerability of coral reef fishes

    PubMed Central

    Graham, Nicholas A J; Chabanet, Pascale; Evans, Richard D; Jennings, Simon; Letourneur, Yves; Aaron MacNeil, M; McClanahan, Tim R; Öhman, Marcus C; Polunin, Nicholas V C; Wilson, Shaun K

    2011-01-01

    With rapidly increasing rates of contemporary extinction, predicting extinction vulnerability and identifying how multiple stressors drive non-random species loss have become key challenges in ecology. These assessments are crucial for avoiding the loss of key functional groups that sustain ecosystem processes and services. We developed a novel predictive framework of species extinction vulnerability and applied it to coral reef fishes. Although relatively few coral reef fishes are at risk of global extinction from climate disturbances, a negative convex relationship between fish species locally vulnerable to climate change vs. fisheries exploitation indicates that the entire community is vulnerable on the many reefs where both stressors co-occur. Fishes involved in maintaining key ecosystem functions are more at risk from fishing than climate disturbances. This finding is encouraging as local and regional commitment to fisheries management action can maintain reef ecosystem functions pending progress towards the more complex global problem of stabilizing the climate. PMID:21320260

  19. Camana, Peru, and Tsunami Vulnerability

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A tsunami washed over the low-lying coastal resort region near Camana, southern Peru, following a strong earthquake on June 23, 2001. The earthquake was one of the most powerful of the last 35 years and had a magnitude of 8.4. After the initial quake, coastal residents witnessed a sudden drawdown of the ocean and knew a tsunami was imminent. They had less than 20 minutes to reach higher ground before the tsunami hit. Waves as high as 8 m came in four destructive surges reaching as far as 1.2 km inland. The dashed line marks the approximate area of tsunami inundation. Thousands of buildings were destroyed, and the combined earthquake and tsunami killed as many as 139 people. This image (ISS004-ESC-6128) was taken by astronauts onboard the International Space Station on 10 January 2002. It shows some of the reasons that the Camana area was so vulnerable to tsunami damage. The area has a 1 km band of coastal plain that is less than 5 m in elevation. Much of the plain can be seen by the bright green fields of irrigated agriculture that contrast with the light-colored desert high ground. Many of the tsunami-related deaths were workers in the onion fields in the coastal plain that were unwilling to leave their jobs before the end of the shift. A number of lives were spared because the tsunami occurred during the resort off-season, during the daylight when people could see the ocean drawdown, and during one of the lowest tides of the year. Information on the Tsunami that hit Camana can be found in a reports on the visit by the International Tsunami Survey Team and the USC Tsunami Research Lab. Earthquake Epicenter, Peru shows another image of the area. Image provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  20. [Vulnerability and National Health Service].

    PubMed

    Lima, Cristina

    2006-01-01

    to value life. The article concludes drawing attention to the need to invest in health education, which is just as important as the fair distribution of precious health care resources in reducing harmful risks to the most vulnerable patients.