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1

Vulnerable Plaque  

MedlinePLUS

... within an artery leading to the heart or brain. With time, the plaque buildup would narrow the artery so much that the artery would either close off or become clogged by a blood clot (much like a clogged drain). The lack of oxygen-rich blood to the ...

2

Fishbowl Plaques.  

ERIC Educational Resources Information Center

Presents an elementary art activity that successfully teaches the process of slabbing by having students create fishbowl plaques. Explains the process step-by-step beginning with a demonstration to the students along with showing previous examples. Endorses a type of clay that fires white because the glaze colors are much more vibrant. (CMK)

Lambert, Phyllis Gilchrist

1998-01-01

3

Inflammation and Plaque Vulnerability  

Microsoft Academic Search

Development of a thrombus at the site of an atherosclerotic plaque initiates abrupt arterial occlusion and is the proximate\\u000a event responsible for the vast majority of acute ischemic syndromes. In nearly 75% of cases thrombus overlies a disrupted\\u000a or ruptured plaque whereas the remainder of the thrombi overly an intact plaque with superficial endothelial erosion. Over\\u000a the past several years,

Prediman K. Shah

2009-01-01

4

Biomarkers of plaque instability.  

PubMed

Atherosclerosis is the proximate cause of arterial thrombosis, leading to acute occlusive cardiovascular syndromes. Thrombosis in atherosclerosis usually results from rupture of the fibrous cap of atherosclerotic plaques with a smaller proportion resulting from superficial endothelial erosion. Ruptured plaques are often associated with intimal and adventitial inflammation, increased size of lipid-rich necrotic core with thinned out collagen-depleted fibrous cap, outward remodeling, increased plaque neovascularity, intraplaque hemorrhage, and microcalcification. By inference, non-ruptured plaques with similar compositional features are considered to be at risk for rupture and hence are labeled vulnerable plaques or high-risk plaques. Identification of vulnerable plaques may help in predicting the risk of acute occlusive syndromes and may also allow targeting for aggressive systemic and possibly local therapies. Plaque rupture is believed to result from extracellular matrix (which comprises the protective fibrous cap) dysregulation due to excessive proteolysis in the context of diminished matrix synthesis. Inflammation is believed to play a key role by providing matrix-degrading metalloproteinases and also by inducing death of matrix-synthesizing smooth muscle cells. Systemic markers of inflammation are thus the most logical forms of potential biomarkers which may predict the presence of vulnerable or high-risk plaques. Several studies have suggested the potential prognostic value of a variety of systemic markers, but regrettably, their overall clinical predictive value is modestly incremental at best, especially for individual subjects compared to groups of patients. Nevertheless, continued investigation of reliable, cost-effective biomarkers that predict the presence of a high-risk plaque and future athero-thrombotic cardiovascular events with greater sensitivity and specificity is warranted. PMID:25326730

Shah, P K

2014-12-01

5

High Field Atherosclerotic Plaque MRI  

PubMed Central

Manifestations of atherosclerotic plaque in different arterial beds range from perfusion deficits to overt ischemia such as stroke and myocardial infarction. Atherosclerotic plaque composition is known to be associated with its propensity to rupture and cause vascular events. MRI of atherosclerotic plaque using clinical 1.5T scanners can detect plaque composition. Plaque MRI at higher field strengths offers both opportunities and challenges to improving the high spatial-resolution and contrast required for this type of imaging. This article summarizes the technological requirements required for high field plaque MRI and its application in detecting plaque components. PMID:22548932

Yuan, Chun; Wang, Jinnan; Balu, Niranjan

2012-01-01

6

Denitrification in human dental plaque  

Microsoft Academic Search

BACKGROUND: Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate (NO3-) concentrations in the millimolar range and that dental plaque houses bacteria that

Frank Schreiber; Peter Stief; Armin Gieseke; Ines M Heisterkamp; Willy Verstraete; Dirk de Beer; Paul Stoodley

2010-01-01

7

Plaque Assay for Rickettsia rickettsii  

PubMed Central

A plaque technique for the assay of Rickettsia rickettsii is described. The method employs primary chick or green monkey kidney monolayer cell cultures with either an agarose or special Noble agar overlay. Plaques were counted in 6 days and resultant titers correlated well with ld50 end points obtained by a standard assay in embryonated eggs. Identification of the plaque-forming organisms was accomplished by direct observation of rickettsiae-like bodies in the monolayer lesions, inhibition of plaques by antibiotics, sensitivity of plaques to specific immune serum, and failure to cultivate other microorganisms from the infected cells. Versatility of the test was demonstrated by assaying samples of rickettsiae from several different sources commonly used in our laboratory. These included infected yolk sacs, various cell cultures, and infected guinea pig tissue. Sufficient numbers of viable rickettsiae were present in the cells of a single lesion to permit direct recovery. Images PMID:4977475

Weinberg, Edmund H.; Stakebake, Jack R.; Gerone, Peter J.

1969-01-01

8

Plaque assay for Rickettsia rickettsii.  

PubMed

A plaque technique for the assay of Rickettsia rickettsii is described. The method employs primary chick or green monkey kidney monolayer cell cultures with either an agarose or special Noble agar overlay. Plaques were counted in 6 days and resultant titers correlated well with ld(50) end points obtained by a standard assay in embryonated eggs. Identification of the plaque-forming organisms was accomplished by direct observation of rickettsiae-like bodies in the monolayer lesions, inhibition of plaques by antibiotics, sensitivity of plaques to specific immune serum, and failure to cultivate other microorganisms from the infected cells. Versatility of the test was demonstrated by assaying samples of rickettsiae from several different sources commonly used in our laboratory. These included infected yolk sacs, various cell cultures, and infected guinea pig tissue. Sufficient numbers of viable rickettsiae were present in the cells of a single lesion to permit direct recovery. PMID:4977475

Weinberg, E H; Stakebake, J R; Gerone, P J

1969-05-01

9

Small Plaque Mutants of the Sindbis Virus.  

National Technical Information Service (NTIS)

In embryo cell cultures in gel medium infected with the Sindbis virus, two types of plaques appear: large (G) and small (p) plaques. The G plaques appear in 24 hours and grow until they attain a diameter of more than 20mm. The small plaques (p) appear aft...

C. Hannoun, J. Asso, P. Ardoin

1965-01-01

10

Plaque Assay for Murine Norovirus  

PubMed Central

Murine norovirus (MNV) is the only member of the Norovirus genus that efficiently grows in tissue culture 1, 2. Cell lysis and cytopathic effect (CPE) are observed during MNV-1 infection of murine dendritic cells or macrophages 1. This property of MNV-1 can be used to quantify the number of infectious particles in a given sample by performing a plaque assay 1. The plaque assay relies on the ability of MNV-1 to lyse cells and to form holes in a confluent cell monolayer, which are called plaques 3. Multiple techniques can be used to detect viral infections in tissue culture, harvested tissue, clinical, and environmental samples, but not all measure the number of infectious particles (e.g. qRT-PCR). One way to quantify infectious viral particles is to perform a plaque assay 3, which will be described in detail below. A variation on the MNV plaque assay is the fluorescent focus assay, where MNV antigen is immunostained in cell monolayers 4. This assay can be faster, since viral antigen expression precedes plaque formation. It is also useful for titrating viruses unable to form plaques. However, the fluorescent focus assay requires additional resources beyond those of the plaque assay, such as antibodies and a microscope to count focus-forming units. Infectious MNV can also be quantified by determining the 50% Tissue Culture Infective Dose (TCID50) 3. This assay measures the amount of virus required to produce CPE in 50% of inoculated tissue culture cells by endpoint titration 5. However, its limit of detection is higher compared to a plaque assay 4. In this article, we describe a plaque assay protocol that can be used to effectively determine the number of infectious MNV particles present in biological or environmental samples 1, 4, 6. This method is based on the preparation of 10-fold serial dilutions of MNV-containing samples, which are used to inoculate a monolayer of permissive cells (RAW 264.7 murine macrophage cells). Virus is allowed to attach to the cell monolayer for a given period of time and then aspirated before covering cells with a mixture of agarose and cell culture media. The agar enables the spread of viral progeny to neighboring cells while limiting spread to distantly located cells. Consequently, infected cells are lysed and form holes in the monolayer known as plaques. Upon sufficient spread of virus, plaques become visible following staining of cells with dyes, like neutral red, methylene blue, or crystal violet. At low dilutions, each plaque originates from one infectious viral particle and its progeny, which spread to neighboring cells. Thus, counting the number of plaques allows one to calculate plaque-forming units (PFU) present in the undiluted sample 3. PMID:22951568

Gonzalez-Hernandez, Mariam B.; Bragazzi Cunha, Juliana; Wobus, Christiane E.

2012-01-01

11

Progress in atherosclerotic plaque imaging  

PubMed Central

Cardiovascular diseases are the primary cause of mortality in the industrialized world, and arterial obstruction, triggered by rupture-prone atherosclerotic plaques, lead to myocardial infarction and cerebral stroke. Vulnerable plaques do not necessarily occur with flow-limiting stenosis, thus conventional luminographic assessment of the pathology fails to identify unstable lesions. In this review we discuss the currently available imaging modalities used to investigate morphological features and biological characteristics of the atherosclerotic plaque. The different imaging modalities such as ultrasound, magnetic resonance imaging, computed tomography, nuclear imaging and their intravascular applications are illustrated, highlighting their specific diagnostic potential. Clinically available and upcoming methodologies are also reviewed along with the related challenges in their clinical translation, concerning the specific invasiveness, accuracy and cost-effectiveness of these methods. PMID:22937215

Soloperto, Giulia; Casciaro, Sergio

2012-01-01

12

Imaging Atherosclerosis and Vulnerable Plaque  

PubMed Central

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. PMID:20395341

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

2010-01-01

13

Molecular imaging of plaque vulnerability.  

PubMed

Over the past decade, significant progress has been made in the development of novel imaging strategies focusing on the biology of the vessel wall for identification of vulnerable plaques. While the majority of these studies are still in the pre-clinical stage, few techniques (e.g., (18)F-FDG and (18)F-NaF PET imaging) have already been evaluated in clinical studies with promising results. Here, we will briefly review the pathobiology of atherosclerosis and discuss molecular imaging strategies that have been developed to target these events, with an emphasis on mechanisms that are associated with atherosclerotic plaque vulnerability. PMID:25124827

Tavakoli, Sina; Vashist, Aseem; Sadeghi, Mehran M

2014-12-01

14

Interstitial granulomatous dermatitis with plaques  

Microsoft Academic Search

Background: Interstitial granulomatous dermatitis is a histopathologic pattern with variable clinical appearance associated with autoimmune systemic diseases. The frequency of its different cutaneous expressions and its association with autoimmune diseases are not known. Objective: We describe the clinical, serologic, and histologic features in 17 patients with interstitial granulomatous dermatitis with a clinical presentation consisting of large erythematous plaques. Method: Skin

Carlo Tomasini; Mario Pippione

2002-01-01

15

Reproducibility in Ultrasonic Characterization of Carotid Plaques  

Microsoft Academic Search

Background and Purpose: Echolucent carotid plaques compared with echogenic plaques could carry a significant risk of transient ischemic attacks and strokes, but the reproducibility of new ultrasonic methods has not yet been proved. The objective was to evaluate interobserver and intraobserver agreement in characterizing the carotid plaques studied by both B mode imaging and color Doppler imaging, which is the

J. M. de Bray; J. M. Baud; P. Delanoy; J. P. Camuzat; V. Dehans; J. Descamp-Le Chevoir; J. R. Launay; F. Luizy; Y. Sentou; P. Cales

1998-01-01

16

Imaging Atherosclerosis and Risk of Plaque Rupture  

PubMed Central

Atherosclerosis imaging strategies can delineate characteristics of plaques at risk of rupture and thrombosis. Structural plaque imaging identifies high-risk plaque features including lipid pools, thin fibrous caps, and intraplaque hemorrhage, among others. New molecular imaging techniques complement structural imaging approaches by illuminating important features of plaque biology, with a prominent focus on detecting inflammation as a high-risk phenotype. As we unravel the molecular and structural characteristics underlying thrombosis-prone plaques, there is significant promise for eventual early identification and prediction of atherosclerotic plaque complications before they occur. Here we focus on recent imaging insights into high-risk arterial plaques, the etiologic agent of acute myocardial infarction (MI), stroke, and sudden cardiac death. PMID:23982263

Osborn, Eric A; Jaffer, Farouc A

2013-01-01

17

Fluoride in Dental Plaque and its Effects  

Microsoft Academic Search

Total plaque fluoride is in the range 5-10 mg\\/kg (ppm) on a wet-weight basis. The variability of literature data on plaque fluoride is partly ascribed to analytical problems, many assays being close to or below the concentration detection limit of the fluoride electrode. A change in classification of plaque fluoride compartments is necessary, since recent work indicates that there are

A. Tatevossian

1990-01-01

18

The relevance of Randall's plaques  

PubMed Central

The pathophysiology of nephrolithiasis is not fully understood. The pioneering work of Alexander Randall in the 1940s sought to clarify our understanding of stone formation. This review traces the inception of the theory of Randall's plaques and the refinement of the hypothesis in the early days of kidney stone research. It then reviews the contemporary findings utilizing sophisticated investigative techniques that shed additional light on the pathophysiology and redefine the seminal findings of Dr. Randall that were made 70 years ago. PMID:24497683

Strakosha, Ruth; Monga, Manoj; Wong, Michael Y. C.

2014-01-01

19

Biomechanics and Inflammation in Atherosclerotic Plaque Erosion and Plaque Rupture: Implications for Cardiovascular Events in Women  

PubMed Central

Objective Although plaque erosion causes approximately 40% of all coronary thrombi and disproportionally affects women more than men, its mechanism is not well understood. The role of tissue mechanics in plaque rupture and regulation of mechanosensitive inflammatory proteins is well established, but their role in plaque erosion is unknown. Given obvious differences in morphology between plaque erosion and rupture, we hypothesized that inflammation in general as well as the association between local mechanical strain and inflammation known to exist in plaque rupture may not occur in plaque erosion. Therefore, our objective was to determine if similar mechanisms underlie plaque rupture and plaque erosion. Methods and Results We studied a total of 74 human coronary plaque specimens obtained at autopsy. Using lesion-specific computer modeling of solid mechanics, we calculated the stress and strain distribution for each plaque and determined if there were any relationships with markers of inflammation. Consistent with previous studies, inflammatory markers were positively associated with increasing strain in specimens with rupture and thin-cap fibroatheromas. Conversely, overall staining for inflammatory markers and apoptosis were significantly lower in erosion, and there was no relationship with mechanical strain. Samples with plaque erosion most closely resembled those with the stable phenotype of thick-cap fibroatheromas. Conclusions In contrast to classic plaque rupture, plaque erosion was not associated with markers of inflammation and mechanical strain. These data suggest that plaque erosion is a distinct pathophysiological process with a different etiology and therefore raises the possibility that a different therapeutic approach may be required to prevent plaque erosion. PMID:25365517

Campbell, Ian C.; Suever, Jonathan D.; Timmins, Lucas H.; Veneziani, Alessandro; Vito, Raymond P.; Virmani, Renu; Oshinski, John N.; Taylor, W. Robert

2014-01-01

20

Iron plaque formation on seagrasses: Why not?  

Microsoft Academic Search

Iron (Fe) plaque formation is a well known phenomenon in wetland, freshwater and salt marsh species; however there are no reports about Fe plaque occurrence in seagrasses. Here we review the main factors regulating Fe deposition on the roots and rhizomes of plants from reduced sediments\\/soils, and discuss these factors in relation to marine environment. Moreover, we present some early

K atrina Povidisa; Marianne Holmer

2008-01-01

21

Advanced Techniques for MRI of Atherosclerotic Plaque  

PubMed Central

This review examines the state of the art in vessel wall imaging by MRI with an emphasis on the biomechanical assessment of atherosclerotic plaque. Three areas of advanced techniques are discussed. First, alternative contrast mechanisms, including susceptibility, magnetization transfer, diffusion and perfusion, are presented in regards to how they facilitate accurate determination of plaque constituents underlying biomechanics. Second, imaging technologies, including hardware and sequences, are reviewed in regards to how they provide the resolution and SNR necessary for determining plaque structure. Finally, techniques for combining MRI data into an overall assessment of plaque biomechanical properties, including wall shear stress and internal plaque strain, are presented. The paper closes with a discussion of the extent to which these techniques have been applied to different arteries commonly targeted by vessel wall MRI. PMID:20805732

Kerwin, William S.; Canton, Gador

2011-01-01

22

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

PubMed Central

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

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

2014-01-01

23

Retinal arterial plaques in acquired immunodeficiency syndrome  

PubMed Central

The authors report the unusual observation discrete plaque like excrescencies along the retinal arterial wall in a young patient with acquired immunodeficiency syndrome. Though bilateral, in the right eye there was severe arteriolar narrowing and so these plaques were less identifiable. Fluorescein angiography did not reveal any arteriolar occlusion or areas of capillary occlusion in both eyes. There were no other signs of HIV associated microangiopathy and the patient did not have any concurrent cardiovascular or hematological abnormality. The cause of these plaques remains unexplained and we conjecture that they could represent macro immune-complex deposition along the arteriolar walls. PMID:24765430

Venkatesh, Pradeep; Pathak, Harish; Garg, Satpal

2012-01-01

24

Atherosclerosis and Atheroma Plaque Rupture: Imaging Modalities in the Visualization of Vasa Vasorum and Atherosclerotic Plaques  

PubMed Central

Invasive angiography has been widely accepted as the gold standard to diagnose cardiovascular pathologies. Despite its superior resolution of demonstrating atherosclerotic plaque in terms of degree of lumen stenosis, the morphological assessment for the plaque is insufficient for the analysis of plaque components, and therefore, unable to predict the risk status or vulnerability of atherosclerotic plaque. There is an increased body of evidence to show that the vasa vasorum play an important role in the initiation, progression, and complications of atherosclerotic plaque leading to major adverse cardiac events. This paper provides an overview of the evidence-based reviews of various imaging modalities with regard to their potential value for comprehensive characterization of the composition, burden, and neovascularization of atherosclerotic plaque. PMID:24688380

2014-01-01

25

Historical Plaque at Marshall Space Flight Center  

NASA Technical Reports Server (NTRS)

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.

2002-01-01

26

Thermal study of vulnerable atherosclerotic plaque  

E-print Network

Atherosclerotic plaques with high probability of rupture show the presence of a hot spot due to the accumulation of inflammatory cells. This study utilizes two and three dimensional (2-D and 3-D) arterial geometries containing an atherosclerotic...

Kim, Taehong

2009-05-15

27

Vascular MR segmentation: wall and plaque  

NASA Astrophysics Data System (ADS)

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.

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

2003-05-01

28

A special type of senile plaque, possibly an initial stage  

Microsoft Academic Search

It is customary to distinguish “primitive”, “classic” and “compact” (“burned out”) senile plaques in Alzheimer's disease and senile dementia of the Alzheimer type (SDAT). Primitive plaques are characterized by altered neurites without accumulation of amyloid, classic plaques by an amyloid core surrounded by altered neurites and compact plaques by amyloid without pathological neurites. Here we describe a further type of

A. Probst; H. Brunnschweiler; C. Lautenschlager; J. Ulrich

1987-01-01

29

Characterization of Atherosclerotic Plaques by Laser Speckle Imaging  

Microsoft Academic Search

Background—A method capable of determining atherosclerotic plaque composition and measuring plaque viscoelasticity can provide valuable insight into intrinsic features associated with plaque rupture and can enable the identification of high-risk lesions. In this article, we describe a new optical technique, laser speckle imaging (LSI), that measures an index of plaque viscoelasticity. We evaluate the potential of LSI for characterizing atherosclerotic

Seemantini K. Nadkarni; Brett E. Bouma; Tina Helg; Raymond Chan; Elkan Halpern; Alexandra Chau; Milan Singh Minsky; Jason T. Motz; Stuart L. Houser; Guillermo J. Tearney

2010-01-01

30

Radiolabelled probes for imaging of atherosclerotic plaques  

PubMed Central

Cardiovascular disease is the leading cause of death worldwide. Unstable atherosclerotic plaques are prone to rupture followed by thrombus formation, vessel stenosis, and occlusion and frequently lead to acute myocardial infarction and brain infarction. As such, unstable plaques represent an important diagnostic target in clinical settings and the specific diagnosis of unstable plaques would enable preventive treatments for cardiovascular disease. To date, various imaging methods such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and intravascular ultrasound (IVUS) have been widely used clinically. Although these methods have advantages in terms of spatial resolution and the ability to make detailed identification of morphological alterations such as calcifications and vessel stenosis, these techniques require skill or expertise to discriminate plaque instability, which is essential for early diagnosis and treatment and can present difficulties for quantitative estimation. On the other hand, nuclear imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) can noninvasively collect quantitative information on the expression levels of functional molecules and metabolic activities in vivo and thus provide functional diagnoses of unstable plaques with high sensitivity. Specifically, unstable plaques are characterized by an abundance of invasive inflammatory cells (macrophages), increased oxidative stress that increases oxidized LDL and its receptor expressed on cells in the lesions, increased occurrence of apoptosis of macrophages and other cells involved in disease progression, increased protease expression and activity, and finally thrombus formation triggered by plaque rupture, which is the most important mechanism leading to the onset of infarctions and ischemic sudden death. Therefore, these characteristics can all be targets for molecular imaging by PET and SPECT. In this paper, we review the present state and future of radiolabelled probes that have been developed for detecting atherosclerotic unstable plaques with nuclear imaging techniques. PMID:23145360

Temma, Takashi; Saji, Hideo

2012-01-01

31

Detection of High-Risk Atherosclerotic Plaque  

PubMed Central

The leading cause of major morbidity and mortality in most countries around the world is atherosclerotic cardiovascular disease, most commonly caused by thrombotic occlusion of a high-risk coronary plaque resulting in myocardial infarction or cardiac death, or embolization from a high-risk carotid plaque resulting in stroke. The lesions prone to result in such clinical events are termed vulnerable or high-risk plaques, and their identification may lead to the development of pharmacological and mechanical intervention strategies to prevent such events. Autopsy studies from patients dying of acute myocardial infarction or sudden death have shown that such events typically arise from specific types of atherosclerotic plaques, most commonly the thin-cap fibroatheroma. However, the search in human beings for vulnerable plaques before their becoming symptomatic has been elusive. Recently, the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study demonstrated that coronary plaques that are likely to cause future cardiac events, regardless of angiographic severity, are characterized by large plaque burden and small lumen area and/or are thin-cap fibroatheromas verified by radiofrequency intravascular ultrasound imaging. This study opened the door to identifying additional invasive and noninvasive imaging modalities that may improve detection of high-risk atherosclerotic lesions and patients. Beyond classic risk factors, novel biomarkers and genetic profiling may identify those patients in whom noninvasive imaging for vulnerable plaque screening, followed by invasive imaging for risk confirmation is warranted, and in whom future pharmacological and/or device-based focal or regional therapies may be applied to improve long-term prognosis. PMID:22974808

Fleg, Jerome L.; Stone, Gregg W.; Fayad, Zahi A.; Granada, Juan F.; Hatsukami, Thomas S.; Kolodgie, Frank D.; Ohayon, Jacques; Pettigrew, Roderic; Sabatine, Marc S.; Tearney, Guillermo; Waxman, Sergio; Domanski, Michael J.; Srinivas, Pothur R.; Narula, Jagat

2013-01-01

32

Studies of the Rickettsial Plaque Assay Technique  

PubMed Central

A plaque assay system for pathogenic rickettsiae, which utilizes primary chick embryo tissue cultures, is described. It proved to be a highly reproducible measure of infectiousness for Rickettsia rickettsi and R. typhi, which were employed in most studies; as well as for R. canada, R. prowazeki, R. sibirica, R. akari, R. conori, and Coxiella burneti. Plaque-forming units (PFU) were compared to direct rickettsial counts and to 50% infectious dose (ID50) values for embryonated eggs, mice, and guinea pigs. Plaque size, appearance, and number were influenced by diluent, incubation temperature after nutrient overlay, centrifugation of inoculated tissue cultures, and number of host cells planted initially in each flask. The most critical factors in plaque formation were diluent used in making rickettsial suspensions and incubation temperature (32 C) after nutrient overlay. Brain Heart Infusion was the only diluent capable of preventing significant delay in plaque formation and decreases in PFU and mouse ID50. Plaque formation was unaffected by genetic background of host cells, volume of inoculum, temperature and length of incubation period before nutrient overlay, and rapid freezing and thawing of rickettsial seed. Centrifugation of inoculated cultures at 600 × g resulted in 100% irreversible absorption of rickettsiae to host cells within 5 min, whereas without centrifugation at least 4 hr was required to achieve the same effect. Images PMID:4629250

Wike, David A.; Tallent, George; Peacock, Marius G.; Ormsbee, Richard A.

1972-01-01

33

Coronary plaque imaging with 256-slice multidetector computed tomography: interobserver variability of volumetric lesion parameters with semiautomatic plaque analysis software  

Microsoft Academic Search

The purpose of this study was to evaluate the potential clinical value of coronary plaque imaging with a new generation CT\\u000a scanner and the interobserver variability of coronary plaque assessment with a new semiautomatic plaque analysis application.\\u000a Thirty-five isolated plaques of the left anterior descending coronary artery from 35 patients were evaluated with a new semiautomatic\\u000a plaque analysis application. All

Oliver Klass; Susanne Kleinhans; Matthew J. Walker; Mark Olszewski; Sebastian Feuerlein; Markus Juchems; Martin H. K. Hoffmann

2010-01-01

34

PLAQUE:PLAQUE: What it is and how to get rid of it  

E-print Network

and stick to the teeth. · Some types of plaque cause tooth decay. · Other types of plaque cause gum disease, especially sweets, provide nutrients for the germs that cause tooth decay, as well as those that cause gum--this could harm your gums. Brush Teeth Use any tooth brushing method that is comfortable, but do not scrub

Bandettini, Peter A.

35

Functional expression of dental plaque microbiota  

PubMed Central

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

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

2014-01-01

36

Magnetic Resonance Imaging to Identify Intraplaque Hemorrhage and Define its Location in Complicated Carotid Artery Plaques.  

E-print Network

??Atherosclerotic plaque (AP) composition is an important factor influencing plaque rupture. Intraplaque hemorrhage (IPH) is a marker of complicated-plaque formation, responsible for many of the… (more)

Bitar, Richard

2011-01-01

37

Association between Randall's Plaque and Calcifying Nanoparticles  

NASA Technical Reports Server (NTRS)

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.

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

38

Pigmented epidermal plaques in three dogs.  

PubMed

Papillomavirus was identified in pigmented epidermal plaques (PEP) from three dogs: a miniature schnauzer with hyperadrenocorticism and hypoglobulinemia, an American Staffordshire terrier with hypoglobulinemia, and a Pomeranian with unconfirmed hypothyroidism. Squamous cell carcinoma (SCC) arose within several plaques in the Pomeranian. Clinical improvement coincided in the first two cases with treatment of the concurrent disease and the administration of low-dose oral interferon-alpha. This is the first report of PEP in an American Staffordshire terrier and a Pomeranian. The potential for malignant transformation of PEP to SCC emphasizes the need for recognition and clinical management of PEP. PMID:15347622

Stokking, Laura B; Ehrhart, Eugene J; Lichtensteiger, Carol A; Campbell, Karen L

2004-01-01

39

Atherosclerotic plaque rupture and thrombosis. Evolving concepts.  

PubMed

Rupture of an atherosclerotic plaque associated with partial or complete thrombotic vessel occlusion is fundamental to the development of ischemic coronary syndromes. Plaques that produce only mild-to-moderate angiographic luminal stenosis are frequently those that undergo abrupt disruption, leading to unstable angina or acute myocardial infarction. Plaques with increased lipid content appear more prone to rupture, particularly when the lipid pool is localized eccentrically within the intima. Macrophages appear to play an important role in atherogenesis, perhaps by participating in the uptake and metabolism of lipoproteins, secretion of growth factors, and production of enzymes and toxic metabolites that may facilitate plaque rupture. In addition, the particular composition or configuration of a plaque and the hemodynamic forces to which it is exposed may determine its susceptibility to disruption. Exposure of collagen, lipids, and smooth muscle cells after plaque rupture leads to the activation of platelets and the coagulation cascade system. The resulting thrombus may lead to marked reduction in myocardial perfusion and the development of an unstable coronary syndrome, or it may become organized and incorporated into the diseased vessel, thus contributing to the progression of atherosclerosis. In unstable angina, plaque disruption leads to thrombosis, which is usually labile and results in only a transient reduction in myocardial perfusion. Release of vasoactive substances, arterial spasm, or increases in myocardial oxygen demand may contribute to ischemia. In acute myocardial infarction, plaque disruption results in a more persistent thrombotic vessel occlusion; the extent of necrosis depends on the size of the artery, the duration of occlusion, the presence of collateral flow, and the integrity of the fibrinolytic system. Thrombi that undergo lysis expose a highly thrombogenic surface to the circulating blood, which has the capacity of activating platelets and the coagulation cascade system and may lead to thrombotic reocclusion. Measurements aimed at reversing the process of atherosclerosis via cholesterol reduction and enhanced high density lipoprotein activity are encouraging. Active research is being focused on the development of new antithrombotic tools, such as inhibitors of thrombin, thromboxane, and serotonin receptor antagonists, and monoclonal antibodies aimed at blocking platelet membrane receptors or adhesive proteins. These compounds may prove useful when immediate and potent inhibition of the hemostatic system is desired. Intensive research is still needed in the areas of pathogenesis and therapeutic intervention in atherosclerosis. PMID:2203564

Fuster, V; Stein, B; Ambrose, J A; Badimon, L; Badimon, J J; Chesebro, J H

1990-09-01

40

Assessment of vulnerable plaque composition by matching the deformation of a parametric plaque model to measured plaque deformation  

Microsoft Academic Search

Intravascular ultrasound (IVUS) elastography visualizes local radial strain of arteries in so-called elastograms to detect rupture-prone plaques. However, due to the unknown arterial stress distribution these elastograms cannot be directly interpreted as a morphology and material composition image. To overcome this limitation we have developed a method that reconstructs a Young's modulus image from an elastogram. This method is especially

Radj A. Baldewsing; Johannes A. Schaar; Frits Mastik; Cees. W. J. Oomens; Antonius F. W. van der Steen

2005-01-01

41

Coronary CT Angiography in the Quantitative Assessment of Coronary Plaques  

PubMed Central

Coronary computed tomography angiography (CCTA) has been recently evaluated for its ability to assess coronary plaque characteristics, including plaque composition. Identification of the relationship between plaque composition by CCTA and patient clinical presentations may provide insight into the pathophysiology of coronary artery plaque, thus assisting identification of vulnerable plaques which are associated with the development of acute coronary syndrome. CCTA-generated 3D visualizations allow evaluation of both coronary lesions and lumen changes, which are considered to enhance the diagnostic performance of CCTA. The purpose of this review is to discuss the recent developments that have occurred in the field of CCTA with regard to its diagnostic accuracy in the quantitative assessment of coronary plaques, with a focus on the characterization of plaque components and identification of vulnerable plaques. PMID:25162010

2014-01-01

42

Exocytosis of polymorphonuclear leukocyte lysosomal contents induced by dental plaque.  

PubMed Central

Rabbit polymorphonuclear leukocytes were incubated with a sonically treated suspension of pooled dental plaque to determine if the plaque would induce release of lysosomal enzymes from the polymorphonuclear leukocytes. Cells incubated with plaque at 37 degrees C released significantly greater amounts of the lysosomal enzymes, beta-glucuronidase and lysozyme, than did cells incubated with plaque at 0 degrees C or without plaque at 37 degrees C. This response was both dose and time dependent. Release of the cytoplasmic enzyme lactate dehydrogenase was minimal, and there were no significant differences in lactate dehydrogenase release between cells at 0 and 37 degrees C, or without plaque. These results indicate that dental plaque can induce the selective release of lysosomal enzymes, which could be involved in the periodontal injury produced by dental plaque. PMID:561032

White, R R; Montgomery, E H

1977-01-01

43

AdipositasErhöhte Mortalität durch arteriosklerotische Folgekrankheiten und Karzinome  

Microsoft Academic Search

Zum Thema  \\u000a „La?t wohlbeleibte M?nner um mich sein …” so ?bersetzt A.W. Schlegel die Worte Caesars in Shakespeares Julius Caesar (1, 2).\\u000a Der Dichter hatte sich noch eindeutiger ausgedr?ckt: „let me have men about me that are fat …” Wenn auch nach unserem Sprachgef?hl\\u000a hier ein Unterschied ist, der Begriff „wohlbeleibt” oder „fat” ist sicher eher positiv als negativ besetzt.

A. Wirth

1997-01-01

44

Association between Randall's Plaque and Calcifying Nanoparticles  

NASA Technical Reports Server (NTRS)

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.

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

45

Interstitial granulomatous dermatitis with plaques and arthritis.  

PubMed

Interstitial granulomatous dermatitis and arthritis (IGDA) is a rare disease entity with female predominance. The case of a 53-year-old woman with erythemas, plaques and nodules associated with polyarthritis is presented. She was treated with cyclosporin A, with improvement of the joint affliction and complete clearance of skin lesions. The differential diagnosis of IGDA is discussed briefly. PMID:14579165

Wollina, U; Schönlebe, J; Unger, L; Weigel, K; Köstler, E; Nüsslein, H

2003-10-01

46

Interstitial granulomatous dermatitis with plaques and arthritis  

Microsoft Academic Search

Interstitial granulomatous dermatitis and arthritis (IGDA) is a rare disease entity with female predominance. The case of a 53-year-old woman with erythemas, plaques and nodules associated with polyarthritis is presented. She was treated with cyclosporin A, with improvement of the joint affliction and complete clearance of skin lesions. The differential diagnosis of IGDA is discussed briefly.

U. Wollina; J. Schönlebe; L. Unger; K. Weigel; E. Köstler; H. Nüsslein

2003-01-01

47

In vivo imaging reveals sigmoidal growth kinetic of ?-amyloid plaques  

PubMed Central

A major neuropathological hallmark of Alzheimer’s disease is the deposition of amyloid plaques in the brains of affected individuals. Amyloid plaques mainly consist of fibrillar ?-amyloid, which is a cleavage product of the amyloid precursor protein. The amyloid-cascade-hypothesis postulates A? accumulation as the central event in initiating a toxic cascade leading to Alzheimer’s disease pathology and, ultimately, loss of cognitive function. We studied the kinetics of ?-amyloid deposition in Tg2576 mice, which overexpress human amyloid precursor protein with the Swedish mutation. Utilizing long-term two-photon imaging we were able to observe the entire kinetics of plaque growth in vivo. Essentially, we observed that plaque growth follows a sigmoid-shaped curve comprising a cubic growth phase, followed by saturation. In contrast, plaque density kinetics exhibited an asymptotic progression. Taking into account the fact that a critical concentration of A? is required to seed new plaques, we can propose the following kinetic model of ?-amyloid deposition in vivo. In the early cubic phase, plaque growth is not limited by A? concentration and plaque density increases very fast. During the transition phase, plaque density stabilizes whereas plaque volume increases strongly reflecting a robust growth of the plaques. In the late asymptotic phase, A? peptide production becomes rate-limiting for plaque growth. In conclusion, the present study offers a direct link between in vitro and in vivo studies facilitating the translation of A?-lowering strategies from laboratory models to patients. PMID:24678659

2014-01-01

48

The pathology of atherosclerosis: plaque development and plaque responses to medical treatment.  

PubMed

Atherosclerosis develops over the course of 50 years, beginning in the early teenage years. The causes of this process appear to be lipid retention, oxidation, and modification, which provoke chronic inflammation at susceptible sites in the walls of all major conduit arteries. Initial fatty streaks evolve into fibrous plaques, some of which develop into forms that are vulnerable to rupture, causing thrombosis or stenosis. Erosion of the surfaces of some plaques and rupture of a plaque's calcific nodule into the artery lumen also may trigger thrombosis. The process of plaque development is the same regardless of race/ethnicity, sex, or geographic location, apparently worldwide. However, the rate of development is faster in patients with risk factors such as hypertension, tobacco smoking, diabetes mellitus, obesity, and genetic predisposition. Clinical trial data demonstrate that treatment with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) favorably alters plaque size, cellular composition, chemical composition, and biological activities centered on inflammation and cholesterol metabolism, as well as the risk of clinical events due to atherosclerosis. Even with advanced atherosclerosis, statins begin to improve clinical risk within 4 months. During long-term follow-up in clinical trials for up to 11 years with or without further treatment, clinical benefit remains significant, indicating the durability of treatment-induced changes in the development of plaque. Thus, atherosclerosis, a disease heretofore viewed as inevitably progressive, can be treated to significantly alter arterial lesions and reduce their clinical consequences. PMID:19110086

Insull, William

2009-01-01

49

Atherosclerotic plaque characterization by spatial and temporal speckle pattern analysis  

NASA Astrophysics Data System (ADS)

Improved methods are needed to identify the vulnerable coronary plaques responsible for acute myocardial infraction or sudden cardiac death. We describe a method for characterizing the structure and biomechanical properties of atherosclerotic plaques based on speckle pattern fluctuations. Near-field speckle images were acquired from five human aortic specimens ex vivo. The speckle decorrelation time constant varied significantly for vulnerable aortic plaques (? = 40 ms) versus stable plaques (? = 400 ms) and normal aorta (? = 500 ms). These initial results indicate that different atherosclerotic plaque types may be distinguished by analysis of temporal and spatial speckle pattern fluctuations.

Tearney, Guillermo J.; Bouma, Brett E.

2002-04-01

50

Imaging of coronary atherosclerosis and identification of the vulnerable plaque  

PubMed Central

Identification of the vulnerable plaque responsible for the occurrence of acute coronary syndromes and acute coronary death is a prerequisite for the stabilisation of this vulnerable plaque. Comprehensive coronary atherosclerosis imaging in clinical practice should involve visualisation of the entire coronary artery tree and characterisation of the plaque, including the three-dimensional morphology of the plaque, encroachment of the plaque on the vessel lumen, the major tissue components of the plaque, remodelling of the vessel and presence of inflammation. Obviously, no single diagnostic modality is available that provides such comprehensive imaging and unfortunately no diagnostic tool is available that unequivocally identifies the vulnerable plaque. The objective of this article is to discuss experience with currently available diagnostic modalities for coronary atherosclerosis imaging. In addition, a number of evolving techniques will be briefly discussed. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7

de Feyter, P.J.; Serruys, P. W.; Nieman, K.; Mollet, N.; Cademartiri, F.; van Geuns, R. J.; Slager, C.; van der Steen, A.F.W.; Krams, R.; Schaar, J.A.; Wielopolski, P.; Pattynama, P.M.T.; Arampatzis, A.; van der Lugt, A.; Regar, E.; Ligthart, J.; Smits, P.

2003-01-01

51

Predominant cultivable flora isolated from human root surface caries plaque.  

PubMed Central

Plaque samples were obtained from tooth surfaces exhibiting typical lesions of root surface caries and were immediately cultured by a continuous anaerobic procedure. The bacterial composition of root caries flora was determined on individual samples. Representative isolates from each specimen were characterized by morphological and physiological criteria. In addition, fluorescent antibody reagents were used to confirm the identification of Streptococcus mutans and Actinomyces viscosus. The plaque samples could be divided into two groups on the basis of the presence or absence of S. mutans in the plaque. In group I plaques, S. mutans comprised 30 percent of the total cultivable flora. S. sanguis was either not found or was present in very low number. In group II plaques, S. mutans was not detected, and S. sanguis formed 48 percent of the total plaque flora. A. viscosus was the dominant organism in all plaque samples, accounting for 47 percent of the group I isolates and 41 percent of the group II isolates. PMID:1091550

Syed, S A; Loesche, W J; Pape, H L; grenier, E

1975-01-01

52

Simple method for plating Escherichia coli bacteriophages forming very small plaques or no plaques under standard conditions.  

PubMed

The use of low concentrations (optimally 2.5 to 3.5 microg/ml, depending on top agar thickness) of ampicillin in the bottom agar of the plate allows for formation of highly visible plaques of bacteriophages which otherwise form extremely small plaques or no plaques on Escherichia coli lawns. Using this method, we were able to obtain plaques of newly isolated bacteriophages, propagated after induction of prophages present in six E. coli O157:H(-) strains which did not form plaques when standard plating procedures were employed. PMID:18586961

Lo?, Joanna M; Golec, Piotr; Wegrzyn, Grzegorz; Wegrzyn, Alicja; Lo?, Marcin

2008-08-01

53

Interstitial granulomatous dermatitis with plaques and arthritis.  

PubMed

Interstitial granulomatous dermatitis (IGD) is a histopathological disorder characterised by an infiltration of the reticular dermis with a predominance of interstitial and palisadic histiocytes with a few areas of degenerating collagen bundles associated with a variable number of polynuclear neutrophils and eosinophils. There are several clinical conditions with a pattern of IGD. The linear form associated with arthritis was the first variety described. There is also a second form, which presents with plaques. This variety may be associated with arthritis, use of certain drugs or the presence of different systemic disorders. We report a case of IGD with plaques and arthritis. We discuss the differential clinical and histological diagnosis with other inflammatory skin lesions, which may be associated with joint disorders and collagen degeneration. We believe that it should be considered in patients presenting with arthritis and skin lesions. PMID:12804998

Bañuls, José; Betlloch, Isabel; Botella, Rafael; Jiménez, Maria José; Blanes, Mar; Pascual, José Carlos; Belinchón, Isabel; Silvestre, Juan Francisco

2003-01-01

54

Enucleation versus plaque irradiation for choroidal melanoma.  

PubMed

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. PMID:3174030

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

1988-07-01

55

Earliest Known Roman London Plaque Discovered  

NSDL National Science Digital Library

Earlier today, archaeologists working on a massive dig on the southern banks of the River Thames uncovered the oldest known plaque inscribed with the city's Roman name, Londinium. While the exact date of the plaque is unknown, it is believed to date from between 50 and 150 AD, and would most likely have been placed on some type of building or in a shrine. Equally important, the plaque offers some initial concrete evidence that there was an emerging merchant class in London during this period. The actual location of the plaque's discovery is near the junction of what were three key roads in Roman Britain, and the finding represents only a small portion of what may be unearthed in this 40-week archaeology project.The first link is to a recent news story about the recent find in London. The second site leads to the Council for British Archaeology, which features numerous links to ongoing research projects within Britain and frequent updates about new findings from the field. The third site offers some perspective on the historical notion of Roman Britain, and particularly how scholars understand that epoch. The fourth site is a link to the complete work "Roman Roads in Britain," a historical study that seeks to describe and delineate the exact location of these very important Roman pathways. Information about the Museum of London, which is working jointly on this project, is provided by the fifth link. The last link, Britannia, is a nice omnibus listing of sites dealing with various aspects of Roman Britain history and archaeology, provided by the Dalton School in New York.

Grinnell, Max

2002-01-01

56

Conversion of plaque-area measurements to plaque index scores. An assessment of variation and discriminatory power.  

PubMed

Plaque areas recorded graphically or photographically provide a permanent record of plaque accumulations on teeth at a moment in time. As such, these records could be re-evaluated and converted into other index scores. The purpose of this study was to determine the reproducibility of scoring a plaque index from previously recorded plaque areas and to compare such scores with the original scores of the same index. A randomised blind, crossover study comparing 5 treatments for plaque inhibition scored by plaque area and index was chosen. 2 examiners, the original scorer PRH and another, NC, 2x scored the plaque area tooth charts according to the criteria of the plaque index system used in the original study. Standard deviations of the differences showed intra-examiner repeatability to be high particularly for the original examiner. Inter-examiner reproducibility for the original index scores was considered good but less than for intra-examiner repeatability. Correlation coefficients were complimentary to the differences analysis, being very high within examiners and less high for between examiners and original and rescored index. Separation between distributions of plaque area measurements for consecutive values of the index were particular good for scores 2 versus 3 and 3 versus 4 and less good for 1 versus 2 and 4 versus 5. Reanalysis of the study for treatment differences using rescored data revealed a similar level of significance as using the original data. Rescored index had similar discriminatory power for the study as plaque area and original plaque index when both were derived from the same buccal tooth surfaces. However, discriminatory power was less by comparison with original plaque index derived from the buccal surfaces of all teeth. It is concluded that plaque area provides a permanent record of plaque distribution which can be converted into index data at a later date. Such data collection could make possible comparisons between studies using different indices. PMID:10412846

Renton-Harper, P; Claydon, N; Warren, P; Newcombe, R G; Addy, M

1999-07-01

57

Atherosclerotic Aortic Arch Plaques in Acute Ischemic Stroke  

PubMed Central

Background: Atherosclerotic aortic arch plaques (AAP) have been linked to an increased risk of thrombo-embolic events as a cause of acute ischemic stroke of undetermined etiology. Objectives: To find out the presence of atherosclerotic plaques in aortic arch and their potential role as a source of embolism in cerebral infarction of undetermined etiology. Methods: We performed trans-esophageal echocardiography (TEE) and multislice computerized tomography (MSCT) of the aortic arch on 30 patients with acute ischemic stroke of undetermined cause from a total series of 150 non-selected patients with acute ischemic stroke studied prospectively by clinical evaluation, laboratory investigations, cranial computed tomography, color coded duplex ultrasonography of the carotid arteries and transcranial Doppler (TCD). Results: Using trans-esophageal echocardiography eight patients (29.6%) had atherosclerotic aortic arch plaques, while using multislice computerized tomography atherosclerotic aortic arch plaques were revealed in twelve patients (40%). Atherosclerotic aortic arch plaques were significantly related to older age, male gender, hypertension, ischemic heart disease and low-grade atherosclerotic carotid lesions. Multislice computerized tomography of the aortic arch was more sensitive than trans-esophageal echocardiography in detecting the site, size and characters of atherosclerotic aortic arch plaques. Conclusion: Atherosclerotic aortic arch plaques are a frequent finding in patients with acute ischemic stroke of undetermined cause supporting the hypothesis that aortic plaques have embolic potential. In addition, multislice computerized tomography is more sensitive than trans-esophageal echocardiography in detecting atherosclerotic aortic arch plaques and better characterization of these plaques especially relevant one. PMID:22518260

Deif, Randa; El-Sayed, Mohamed; allah, Foad Abd; Baligh, Essam; El-Fayomy, Nervana M.; EzzAt, Loai; Gamal, Heba

2011-01-01

58

Assessment of coronary arterial plaque by optical coherence tomography.  

PubMed

The purpose of this study was to analyze the ability of optical coherence tomography (OCT) to identify coronary arterial plaque diagnosed by histologic examination. We examined 166 sections from 108 coronary arterial segments of 40 consecutive human cadavers (24 men and 16 women; mean age 74 +/- 7 years). The plaque type was classified as fibrous (n = 43), fibrocalcific (n = 82), or lipid-rich (n = 41). The accuracy of OCT and intravascular ultrasound (IVUS) in characterizing the plaque type was studied, with the histologic consensus diagnosis serving as the gold standard. OCT, as well as IVUS, had high sensitivity and specificity for characterizing the different types of atherosclerotic plaque. OCT had a higher sensitivity for characterizing lipid-rich plaques than IVUS (85% vs 59%, p = 0.03). In conclusion, the high resolution of OCT permitted evaluation of lipid-rich plaques more accurately than IVUS. PMID:16616021

Kume, Teruyoshi; Akasaka, Takashi; Kawamoto, Takahiro; Watanabe, Nozomi; Toyota, Eiji; Neishi, Yoji; Sukmawan, Renan; Sadahira, Yoshito; Yoshida, Kiyoshi

2006-04-15

59

Dosimetric Benefit of a New Ophthalmic Radiation Plaque  

SciTech Connect

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.

Marwaha, Gaurav, E-mail: marwahg2@ccf.org [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Wilkinson, Allan [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Singh, Arun D. [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States)

2012-12-01

60

Dietary trans fatty acids and composition of human atheromatous plaques.  

PubMed

Dietary fatty acids are incorporated into atheromatous plaques mainly in the form of cholesterol esters. Physicochemical properties of the plaque (e. g. mechanical strength) depend on its fatty acid composition. Trans isomers of unsaturated fatty acids (TFA) are known to reduce the availability of fatty acid precursors for the synthesis of anticoagulant PG(1) and PG(3) prostaglandins. The present study was undertaken to determine the content of trans isomers in atheromatous plaques and to search for correlations between trans isomers in the plaque and adipose tissue. Atheromatous plaques were obtained from 31 patients who underwent surgery due to atherosclerotic stenosis of the abdominal aorta, iliac or femoral arteries. Fatty acids were extracted and separated as methyl esters using gas chromatography (GC) with an internal standard. Correlations were searched for with statistical methods, taking the level of significance as p < 0.05. We found spatial and positional isomers of sixteen- and eighteen-carbon fatty acids in plaques and adipose tissue, with elaidic acid (C18:1 trans-9) being the most abundant. Every plaque and adipose tissue sample contained linolelaidic acid (C18:2 trans-9 trans-12) which is derived exclusively from linoleic acid, as well as conjugated dienes of linoleic acid (CLA) produced during oxidative processes. The presence of trans isomers of fatty acids in the atheromatous plaque seems to be of relevance to plaque formation. Of much concern is the detection of elaidic and linolelaidic acids which adversely affect the physiologically important metabolism of eicosanoids. The TFA pool in adipose tissue has little effect on the amount of these acids in the atheromatous plaque. Apparently, the presence of TFA in atheromatous plaques is the result of processes taking place during plaque formation and maturation. PMID:15309454

Stachowska, Ewa; Do?egowska, Barbara; Chlubek, Dariusz; Weso?owska, Teresa; Ciechanowski, Kazimierz; Gutowski, Piotr; Szumi?owicz, Halina; Turowski, Rados?aw

2004-10-01

61

Development of a quantitative mechanical test of atherosclerotic plaque stability.  

PubMed

Atherosclerotic plaque rupture is the main cause of myocardial infarction and stroke. Both clinical and computational studies indicate that the shoulder region, where a plaque joins the vessel wall, is rupture-prone. Previous mechanistic studies focused on mechanical properties of the fibrous cap and tensile stresses, which could lead to tearing of the cap. Based on clinical observations of "mobile floating plaques," we postulate that de-adhesion between the fibrous cap and the underlying vessel wall may also play a role in plaque failure. Thus, measuring adhesive strength of the bond between plaque and vascular wall may provide useful new insights into plaque stability. Delamination experiments, widely used in examining inter-laminar adhesive strength of biological materials, were used to measure adhesive strength of advanced plaques in apolipoprotein E-knockout (apoE-KO) mice after 8 months on Western diet. We measured adhesive strength in terms of local energy release rate, G, during controlled plaque delamination. As a measure of the fracture energy required to delaminate a unit area of plaque from the underlying internal elastic lamina (IEL), G provides a quantitative measure of local adhesive strength of the plaque-IEL interface. The values for G acquired from 16 plaques from nine apoE-KO mouse aortas formed a positively skewed distribution with a mean of 24.5 J/m(2), median of 19.3 J/m(2), first quartile of 10.8 J/m(2), and third quartile of 34.1 J/m(2). These measurements are in the lower range of values reported for soft tissues. Histological studies confirmed delamination occurred at the interface between plaque and IEL. PMID:21757197

Wang, Ying; Ning, Jinfeng; Johnson, John A; Sutton, Michael A; Lessner, Susan M

2011-09-01

62

Impact de plaques composites : caractérisation et modèles  

NASA Astrophysics Data System (ADS)

We are concerned with the behavior of thin stratified carbon- or glass- epoxy composite plates. The present work is presented as a part of a more wide study carried out which purpose is the numerical simulation of damage evolution within such plates when subjected to a localized transverse low-velocity impact. To establish a correlation between the measured internal damage and the corresponding absorbed energy, from works presented in the literature, is the aim of this one. We first focuse our attention on the typical loading conditions of a direct transverse low-velocity impact. Indeed, we point out the respective role of the impactor/plate contact, indentation and flexion process of the plate on the localization, initiation and propagation of intralaminar cracking and interlaminar delamination. A phenomenological model of interactive evolution of these damages which takes into account the loading and energy absorption process is then proposed, and we identify the interaction between the experimental parameters and the up mentioned damages. We further expose a discussion about some contact law models, and our approach of the loading/structure interaction simulation in terms of the damage phenomenology model presented. Nous nous intéressons au comportement de plaques minces composites stratifiées à fibres longues et à base de carbone/époxyde ou verre/époxyde. Le travail présenté s'insère dans une étude globale visant la simulation numérique de l'évolution de l'endommagement interne des plaques. Le but de cet article est essentiellement de dégager une relation entre l'état d'endommagement mesuré dans la plaque et l'énergie d'impact absorbée correspondante, à partir des travaux exposés dans la littérature. Pour cela, nous présentons notre analyse des conditions de chargement typiques de la sollicitation d'impact transverse direct: nous différencions les, chargements de poinçonnement et de flexion de la plaque sur la localisation, l'initiation et la propagation de la fissuration intralaminaire et du délaminage interlaminaire. Sur la base de cette analyse, nous proposons un modèle phénoménologique d'évolution interactive des dommages tenant compte des modes de chargement et des énergies dissipées, et une identification de l'interaction paramètres expérimentaux/dommages. Nous exposons ensuite notre analyse de modèles de lois de contact par rapport au modèle phénoménologique présenté.

Espinosa, Ch.; Collombet, F.

1991-12-01

63

Dental plaque - associated infections and antibacterial oral hygiene products.  

PubMed

Synopsis Dental plaque accumulates on hard non-shedding surfaces such as teeth, dentures and orthodontic appliances. This accumulation is facilitated by the absence of adequate oral hygiene procedures. The term 'plaque' describes a mass of microorganisms embedded in an organic matrix of host and microbial origin. In addition to the aesthetic desirability of 'clean teeth, healthy gums and fresh breath' associated with the absence of plaque, obvious consequences of the presence of plaque include tooth decay (dental caries), gingivitis and periodontal (gum) disease and denture associated problems. Thus the prevention of plaque formation, the reduction of plaque accumulation and the effective removal of plaque are considerations of the cosmetic and health professions alike. There are many oral hygiene products available to the general public - toothpastes, mouthwashes, denture cleaners, and, more recently, chewing gums and novel mouthwashes. Several of these products have antimicrobial components. This paper reviews the microbiology of plaque and plaque associated problems, and surveys the type of products currently available for maintenance of good oral hygiene. Potential areas for future development are also explored. PMID:19291039

Verran, J

1991-02-01

64

59. SAC Plaque, front lawn, building 500, looking east ...  

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

59. SAC Plaque, front lawn, building 500, looking east - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

65

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

66

Multimodal spectroscopy detects features of vulnerable atherosclerotic plaque  

E-print Network

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 ...

Scepanovic, Obrad R.

67

Plaque rupture with severe pre-existing stenosis precipitating coronary thrombosis. Characteristics of coronary atherosclerotic plaques underlying fatal occlusive thrombi  

Microsoft Academic Search

Ruptured atheromatous plaques were identified by step-sectioning technique as responsible for 40 of 51 recent coronary artery thrombi and 63 larger intimal haemorrhages. The degree of pre-existing luminal narrowing at the site of rupture was decisive for whether plaque rupture caused occlusive thrombosis or just intimal haemorrhage. If the pre-existing stenosis was greater than 90% (histologically determined) then plaque rupture

E Falk

1983-01-01

68

Photolichenoid plaques with associated vitiliginous pigmentary changes.  

PubMed

A 49-year-old man with advanced HIV/AIDS on anti-retroviral therapy (HAART) and trimethoprim-sulfamethoxazole (TMP-SMX) presented with a several-month history of pruritic, erythematous, lichenified papules that coalesced into hyperkeratotic plaques on the trunk and extremities in a sun-exposed distribution. He shortly thereafter developed a progressive depigmentation over more than 80 percent of his body surface area. A biopsy specimen of an erythematous plaque on the trunk showed a superficial and mid-dermal infiltrate of lymphocytes with eosinophils, most consistent with either chronic lichenoid drug eruption or atypical lymphoproliferative disorder (ACLD) of HIV. The patient's lichenoid skin disease has persisted despite discontinuation of TMP-SMX, although it has improved partially with administration of topical glucocorticoids and acitretin. His depigmentation has continued to progress. We discuss the overlapping diagnostic entities which may be comprised by this patient's clinical disease, and highlight a unique presentation of the complex interaction between HIV infection and the skin. PMID:22031639

Tran, Kathleen; Hartman, Rachael; Tzu, Julia; Meehan, Shane; Sanders, Scott E; Pomeranz, Miriam Keltz; Sanchez, Miguel

2011-01-01

69

Inflammation of the Atherosclerotic Cap and Shoulder of the Plaque Is a Common and Locally Observed Feature in Unruptured Plaques of Femoral and Coronary Arteries  

Microsoft Academic Search

Retrospectively, plaque rupture is often colocalized with inflammation of the cap and shoulder of the atherosclerotic plaque. Local inflammation is therefore considered a potential marker for plaque vulnerability. However, high specificity of inflammation for plaque rupture is a requisite for application of inflammation markers to detect rupture-prone lesions. The objective of the present study was to investigate the prevalence and

Gerard Pasterkamp; Arjan H. Schoneveld; Allard C. van der Wal; Dirk-Jan Hijnen; Willem J. A. van Wolveren; Simon Plomp; Hans L. J. M. Teepen; Cornelius Borst

70

Plaque Assay for Q Fever and Scrub Typhus Rickettsiae  

PubMed Central

The plaque assay procedure developed for spotted fever and typhus group rickettsiae is also appropriate for scrub typhus and Q fever rickettsiae. The plaque titers of suspensions of Rickettsia tsutsugamushi and Coxiella burnetii compared favorably with end points obtained by titrations in mice. Images PMID:4989539

McDade, Joseph E.; Gerone, Peter J.

1970-01-01

71

Characterization of bacteriophage communities and CRISPR profiles from dental plaque  

PubMed Central

Background Dental plaque is home to a diverse and complex community of bacteria, but has generally been believed to be inhabited by relatively few viruses. We sampled the saliva and dental plaque from 4 healthy human subjects to determine whether plaque was populated by viral communities, and whether there were differences in viral communities specific to subject or sample type. Results We found that the plaque was inhabited by a community of bacteriophage whose membership was mostly subject-specific. There was a significant proportion of viral homologues shared between plaque and salivary viromes within each subject, suggesting that some oral viruses were present in both sites. We also characterized Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) in oral streptococci, as their profiles provide clues to the viruses that oral bacteria may be able to counteract. While there were some CRISPR spacers specific to each sample type, many more were shared across sites and were highly subject specific. Many CRISPR spacers matched viruses present in plaque, suggesting that the evolution of CRISPR loci may have been specific to plaque-derived viruses. Conclusions Our findings of subject specificity to both plaque-derived viruses and CRISPR profiles suggest that human viral ecology may be highly personalized. PMID:24981669

2014-01-01

72

Small entities with large impact: microcalcifications and atherosclerotic plaque vulnerability  

PubMed Central

Purpose of review Atherosclerotic plaque rupture and subsequent acute events, such as myocardial infarction and stroke, contribute to the majority of cardiovascular-related deaths. Calcification has emerged as a significant predictor of cardiovascular morbidity and mortality, challenging previously held notions that calcifications stabilize atherosclerotic plaques. In this review, we address this discrepancy through recent findings that not all calcifications are equivalent in determining plaque stability. Recent findings The risk associated with calcification is inversely associated with calcification density. As opposed to large calcifications that potentially stabilize the plaque, biomechanical modeling indicates that small microcalcifications within the plaque fibrous cap can lead to sufficient stress accumulation to cause plaque rupture. Microcalcifications appear to derive from matrix vesicles enriched in calcium-binding proteins that are released by cells within the plaque. Clinical detection of microcalcifications has been hampered by the lack of imaging resolution required for in-vivo visualization; however, recent studies have demonstrated promising new techniques to predict the presence of microcalcifications. Summary Microcalcifications play a major role in destabilizing atherosclerotic plaques. The identification of critical characteristics that lead to instability along with new imaging modalities to detect their presence in vivo may allow early identification and prevention of acute cardiovascular events. PMID:25188916

Hutcheson, Joshua D.; Maldonado, Natalia; Aikawa, Elena

2014-01-01

73

Dietary trans fatty acids and composition of human atheromatous plaques  

Microsoft Academic Search

Summary. Dietary fatty acids are incorporated into atheromatous plaques mainly in the form of cholesterol esters. Physicochemical properties of the plaque (e. g. mechanical strength) depend on its fatty acid composition. Trans isomers of unsaturated fatty acids (TFA) are known to reduce the availability of fatty acid precursors for the synthesis of anticoagulant PG 1 and PG 3 prostaglandins. The

Ewa Stachowska; Barbara Do??gowska; Dariusz Chlubek; Teresa Weso?owska; Kazimierz Ciechanowski; Piotr Gutowski; Halina Szumi?owicz; Rados?aw Turowski

2004-01-01

74

Free cholesterol in atherosclerotic plaques: where does it come from?  

Microsoft Academic Search

Purpose of review Free cholesterol in plaques is an emerging contributing factor to lesion instability and, until recently, apoptosis of lipid-laden macrophages was considered the major source of free cholesterol. The validity of this concept is beginning to be challenged since there is recent evidence of erythrocyte membrane-derived cholesterol in plaques. Therefore, intraplaque hemorrhage may not be a passive event,

Frank D. Kolodgie; Allen P. Burke; Gaku Nakazawa; Qi Cheng; Xin Xu; Renu Virmani

2007-01-01

75

Atherosclerotic plaque destabilization: mechanisms, models, and therapeutic strategies.  

PubMed

Understanding the pathophysiology of atherogenesis and the progression of atherosclerosis have been major goals of cardiovascular research during the previous decades. However, the complex molecular and cellular mechanisms underlying plaque destabilization remain largely obscure. Here, we review how lesional cells undergo cell death and how failed clearance exacerbates necrotic core formation. Advanced atherosclerotic lesions are further weakened by the pronounced local activity of matrix-degrading proteases as well as immature neovessels sprouting into the lesion. To stimulate translation of the current knowledge of molecular mechanisms of plaque destabilization into clinical studies, we further summarize available animal models of plaque destabilization. Based on the molecular mechanisms leading to plaque instability, we outline the current status of clinical and preclinical trials to induce plaque stability with a focus on induction of dead cell clearance, inhibition of protease activity, and dampening of inflammatory cell recruitment. PMID:24385514

Silvestre-Roig, Carlos; de Winther, Menno P; Weber, Christian; Daemen, Mat J; Lutgens, Esther; Soehnlein, Oliver

2014-01-01

76

Automated coronary CT angiography plaque-lumen segmentation  

NASA Astrophysics Data System (ADS)

We are investigating the feasibility of a computer-aided detection (CAD) system to assist radiologists in diagnosing coronary artery disease in ECG gated cardiac multi-detector CT scans having calcified plaque. Coronary artery stenosis analysis is challenging if calcified plaque or the iodinated blood pool hides viable lumen. The research described herein provides an improved presentation to the radiologist by removing obscuring calcified plaque and blood pool. The algorithm derives a Gaussian estimate of the point spread function (PSF) of the scanner responsible for plaque blooming by fitting measured CTA image profiles. An initial estimate of the extent of calcified plaque is obtained from the image evidence using a simple threshold. The Gaussian PSF estimate is then convolved with the initial plaque estimate to obtain an estimate of the extent of the blooming artifact and this plaque blooming image is subtracted from the CT image to obtain an image largely free of obscuring plaque. In a separate step, the obscuring blood pool is suppressed using morphological operations and adaptive region growing. After processing by our algorithm, we are able to project the segmented plaque-free lumen to form synthetic angiograms free from obstruction. We can also analyze the coronary arteries with vessel tracking and centerline extraction to produce cross sectional images for measuring lumen stenosis. As an additional aid to radiologists, we also produce plots of calcified plaque and lumen cross-sectional area along selected blood vessels. The method was validated using digital phantoms and actual patient data, including in one case, a validation against the results of a catheter angiogram.

Cline, Harvey E.; Krishnan, Karthik; Napel, Sandy; Rubin, Geoffrey D.; Turner, Wesley D.; Avila, Ricardo S.

2009-02-01

77

Imaging of atherosclerotic plaques in obesity: excessive fat accumulation, plaque progression and vulnerability.  

PubMed

Obesity is becoming a major health issue in the world due to sedentary lifestyles and increasing intake of Western diets. Obesity is associated with metabolic abnormalities and atherosclerotic cardiovascular diseases. Adipose tissue has been increasingly considered to play a critical role in inducing metabolic disturbances and promoting atherogenesis. Arterial wall imaging permits direct visualization of atheroma burden in various vascular beds. In addition, recent advances in imaging technology help characterize components, microstructures and functional features of atherosclerotic plaques. These imaging modalities have contributed to elucidating factors associated with atherosclerosis in obese patients. Also, it provides opportunities to evaluate the effect of novel therapies on plaques in the setting of obesity. The findings of recent imaging studies and the clinical implications will be reviewed. PMID:25355677

Kataoka, Yu; Nicholls, Stephen J

2014-12-01

78

Relationship between Watershed Infarcts and Recent Intra Plaque Haemorrhage in Carotid Atherosclerotic Plaque  

PubMed Central

Objective Watershed infarcts (WSI) are thought to result from hemodynamic mechanism, but studies have suggested that microemboli from unstable carotid plaques may distribute preferentially in watershed areas, i.e., between two cerebral arterial territories. Intraplaque haemorrhage (IPH) is an emerging marker of plaque instability and microembolic activity. We assessed the association between WSI and IPH in patients with recently symptomatic moderate carotid stenosis. Methods and Results We selected 65 patients with symptomatic moderate (median NASCET degree of stenosis?=?31%) carotid stenosis and brain infarct on Diffusion-Weighted Imaging (DWI) on Magnetic Resonance Imaging (MRI) from a multicentre prospective study. Fourteen (22%) had WSI (cortical, n?=?8; internal, n?=?4; cortical and internal, n?=?2). Patients with WSI were more likely to have IPH than those without WSI although the difference was not significant (50% vs. 31%, OR?=?2.19; 95% CI, 0.66–7.29; P?=?0.20). After adjustment for degree of stenosis, age and gender, the results remained unchanged. Conclusion About one in fifth of brain infarcts occurring in patients with moderate carotid stenosis were distributed in watershed areas. Albeit not significant, an association between IPH - more generally plaque component - and WSI, still remains possible. PMID:25272160

Isabel, Clothilde; Lecler, Augustin; Turc, Guillaume; Naggara, Olivier; Schmitt, Emmanuelle; Belkacem, Samia; Oppenheim, Catherine; Touze, Emmanuel

2014-01-01

79

Senile plaque neurites in Alzheimer disease accumulate amyloid precursor protein.  

PubMed Central

Senile plaques are polymorphous beta-amyloid protein deposits found in the brain in Alzheimer disease and normal aging. This beta-amyloid protein is derived from a larger precursor molecule of which neurons are the principal producers in brain. We found that amyloid precursor protein (APP)-immunoreactive neurites were involved in senile plaques and that only a subset of these neurites showed markers for the abnormal filaments characteristic of neurofibrillary pathology. In the neocortex of nondemented individuals with senile plaques but spared of neurofibrillary pathology, dystrophic neurites in senile plaques showed only APP accumulation. In contrast, in the brains of Alzheimer patients, virtually all APP-immunoreactive neurites also showed immunoreactivity with ubiquitin, tau, and phosphorylated neurofilaments. The presence of tau and neurofilament epitopes in dystrophic neurites in senile plaques was correlated with the extent of neurofibrillary pathology in the surrounding brain tissue. Accumulation of APP and the formation of neurofibrillary pathology in senile plaque neurites are therefore distinct phenomena. Our findings suggest that APP accumulation in senile plaque neurites occurs prior to tau accumulation and is therefore more closely related to appearance of neuritic dystrophy. Images PMID:1652752

Cras, P; Kawai, M; Lowery, D; Gonzalez-DeWhitt, P; Greenberg, B; Perry, G

1991-01-01

80

Collagenolytic Activity of Dental Plaque Associated with Periodontal Pathology  

PubMed Central

Certain dental plaques, removed from sites of gingival and periodontal pathology in mentally retarded, institutionalized individuals, when incubated in phosphate buffer with Achilles tendon collagen, gave rise to an increase in ninhydrin-positive material. These plaques, while showing great variability, released significantly more ninhydrin-positive material per milligram of plaque (wet weight) than did either the endogenous or heat-treated controls. Certain plaques could also break down soluble, tritiated, labeled collagen isolated from the calvaria of chicken embryos. Bacteroides melaninogenicus and Clostridia histolyticum were found in plaques by either fluorescent antibody or cultural methods. C. histolyticum, when detected, accounted for about 0.01 to 0.1% of the bacteria in plaque. A conspicuous isolate from some plaques was a Bacillus species which rapidly liquefied gelatin. Cell-free supernatants of this organism were able to degrade about 50 to 70% of the soluble collagen when incubated at 36 C. C. histolyticum ATCC 8034 caused an 80% degradation of the collagen under the same conditions of incubation. The Bacillus strains were facultative, could ferment glucose, reduced nitrate to nitrite, and were catalase, indole, and urease negative. The limited taxonomic information for the isolates is compatible with the description given for Bacillus cereus. PMID:4361294

Loesche, W. J.; Paunio, K. U.; Woolfolk, M. P.; Hockett, R. N.

1974-01-01

81

Intravascular photoacoustic imaging: a new tool for vulnerable plaque identification.  

PubMed

The vulnerable atherosclerotic plaque is believed to be at the root of the majority of acute coronary events. Even though the exact origins of plaque vulnerability remain elusive, the thin-cap fibroatheroma, characterized by a lipid-rich necrotic core covered by a thin fibrous cap, is considered to be the most prominent type of vulnerable plaque. No clinically available imaging technique can characterize atherosclerotic lesions to the extent needed to determine plaque vulnerability prognostically. Intravascular photoacoustic imaging (IVPA) has the potential to take a significant step in that direction by imaging both plaque structure and composition. IVPA is a natural extension of intravascular ultrasound that adds tissue type specificity to the images. IVPA utilizes the optical contrast provided by the differences in the absorption spectra of plaque components to image composition. Its capability to image lipids in human coronary atherosclerosis has been shown extensively ex vivo and has recently been translated to an in vivo animal model. Other disease markers that have been successfully targeted are calcium and inflammatory markers, such as macrophages and matrix metalloproteinase; the latter two through application of exogenous contrast agents. By simultaneously displaying plaque morphology and composition, IVPA can provide a powerful prognostic marker for disease progression, and as such has the potential to transform the current practice in percutaneous coronary intervention. PMID:24631379

Jansen, Krista; van Soest, Gijs; van der Steen, Antonius F W

2014-06-01

82

Non-pulsed electrochemical impregnation of flexible metallic battery plaques  

DOEpatents

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.

Maskalick, Nicholas J. (Pittsburgh, PA)

1982-01-01

83

MRI plaque imaging reveals high-risk carotid plaques especially in diabetic patients irrespective of the degree of stenosis  

PubMed Central

Background Plaque imaging based on magnetic resonance imaging (MRI) represents a new modality for risk assessment in atherosclerosis. It allows classification of carotid plaques in high-risk and low-risk lesion types (I-VIII). Type 2 diabetes mellitus (DM 2) represents a known risk factor for atherosclerosis, but its specific influence on plaque vulnerability is not fully understood. This study investigates whether MRI-plaque imaging can reveal differences in carotid plaque features of diabetic patients compared to nondiabetics. Methods 191 patients with moderate to high-grade carotid artery stenosis were enrolled after written informed consent was obtained. Each patient underwent MRI-plaque imaging using a 1.5-T scanner with phased-array carotid coils. The carotid plaques were classified as lesion types I-VIII according to the MRI-modified AHA criteria. For 36 patients histology data was available. Results Eleven patients were excluded because of insufficient MR-image quality. DM 2 was diagnosed in 51 patients (28.3%). Concordance between histology and MRI-classification was 91.7% (33/36) and showed a Cohen's kappa value of 0.81 with a 95% CI of 0.98-1.15. MRI-defined high-risk lesion types were overrepresented in diabetic patients (n = 29; 56.8%). Multiple logistic regression analysis revealed association between DM 2 and MRI-defined high-risk lesion types (OR 2.59; 95% CI [1.15-5.81]), independent of the degree of stenosis. Conclusion DM 2 seems to represent a predictor for the development of vulnerable carotid plaques irrespective of the degree of stenosis and other risk factors. MRI-plaque imaging represents a new tool for risk stratification of diabetic patients. See Commentary: http://www.biomedcentral.com/1741-7015/8/78/abstract PMID:21118504

2010-01-01

84

Transforming growth factor-?1 in plaque morphea  

PubMed Central

Introduction Morphea (localized scleroderma) is a rare cutaneous disease characterized by skin fibrosis of unknown pathogenesis. Transforming growth factor-? (TGF-?) is a potent profibrotic factor. The role of TGF-? in morphea remains unclear. Aim The goal of this study was to estimate the expression level of TGF-?1 in skin and peripheral blood mononuclear cells as well as the plasma levels of TGF-?1 in plaque morphea (MEP). Material and methods The study involved 20 MEP patients. Three control groups were involved: 1 – plasma: 36 healthy volunteers; 2 – PBMC: 47 healthy volunteers; 3 – skin biopsies: 13 samples collected during mastectomy (breast cancer was not skin involved). The analysis of TGF-?1 plasma levels was performed with the use an adequate ELISA kit, while real-time polymerase chain reaction was employed for the expression of TGF-?1 in peripheral blood mononuclear cells (PBMC) and skin. Results In our study we have not detected differences in TGF-? 1 expression in PBMC, skin, nor in plasma levels of TGF-?1 between MEP patients and healthy controls, regardless of disease activity and its duration. Conclusions The results of our study contradict the claim of the substantial role of TGF-?1 in the most common morphea subtype – MEP. PMID:24493995

Kowalczyk, Michal J.; Szramka-Pawlak, Beata; Gornowicz-Porowska, Justyna; Szewczyk, Aleksandra; Silny, Wojciech; Molinska-Glura, Marta; Olewicz-Gawlik, Anna; Zaba, Ryszard; Pazdrowski, Jakub; Hrycaj, Pawel

2013-01-01

85

Detection of Atherosclerotic Coronary Plaques by Fluorescence Lifetime Imaging Angioscopy  

E-print Network

the potential of a FLIM angioscopy system to detect and differentiate coronary atherosclerotic plaques ex-vivo into several groups including thin, fibrotic, lipid-laden, thick-cap fibroatheroma (FA), and fibrocalcified. Samples were extracted post-mortem weekly...

Thomas, Patrick A.

2010-10-12

86

Advances in mechanisms, imaging and management of the unstable plaque.  

PubMed

Post-mortem observations demonstrated that plaque fissure was the final event leading to coronary thrombosis and occlusion in about two-thirds of cases of sudden coronary death. Plaques prone to fissure have, therefore, been defined "vulnerable plaques" and are identified by specific anatomic features including thin inflamed fibrous cap, large lipidic core and positive remodeling. Accordingly, elegant imaging modalities have been developed in order to identify this "holy grail". However, the results of prognostic studies based on the identification of vulnerable plaques have not been encouraging because of the low positive predictive value for major cardiovascular events. This observation is not surprising as the pathogenesis of acute coronary syndromes is complex and multifactorial. In this review we propose a pathogenetic classification of acute coronary syndromes in the attempt to identify homogeneous groups of patients with a common mechanism of coronary instability which can be identified by using specific biomarkers and imaging techniques, and become a specific therapeutic target. PMID:24530781

Niccoli, Giampaolo; Liuzzo, Giovanna; Montone, Rocco A; Crea, Filippo

2014-04-01

87

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

88

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

89

Ultrasonic tissue characterization of collagen in lipid-rich plaques in apoE-deficient mice  

Microsoft Academic Search

Mechanical failure of the fibrous cap of a vulnerable atherosclerotic plaque may lead to sudden plaque rupture and thus precipitate arterial thrombosis. Because ultrasound correlates strongly with mechanical features of tissues it might provide information on the stability of fibrous caps. The acoustic properties of the normal vessel wall and plaques, particularly fibrous caps of lipid-rich plaques, were evaluated in

Yoshifumi Saijo; Claus Schiøtt Jørgensen; Erling Falk

2001-01-01

90

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

Microsoft Academic Search

IntroductionCurrent evidence indicates that most plaques classified as vulnerable or ruptured plaque 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

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

2006-01-01

91

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

92

Therapeutic Modifications to the Mineral Ion Composition of Dental Plaque  

Microsoft Academic Search

A mouth rinse containing calcium, phosphate, fluoride, urea and monofluorophosphate was used 12 times over 3 days by 15 young adults. The concentration of acid-extractable fluoride in 4-day-old plaque rose from 8.4 to 560 ng\\/mg dry weight. Plaque calcium increased from 4.1 to 42.5 ?g\\/mg and phosphate from 3.9 to 22.7 ?g\\/ mg. The ions are fixed in a form

E. I. F. Pearce

1984-01-01

93

Spectral CT imaging of vulnerable plaque with two independent biomarkers  

Microsoft Academic Search

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

Pavlo Baturin; Yahya Alivov; Sabee Molloi

2012-01-01

94

Improved plaque assays for Rickettsia prowazekii in Vero 76 cells.  

PubMed Central

Typhus group rickettsiae, including Rickettsia prowazekii and R. typhi, produce visible plaques on primary chick embryo fibroblasts and low-passage mouse embryo fibroblasts but do not form reproducible plaques on continuous cell culture lines. We tested medium overlay modifications for plaque formation of typhus group rickettsiae on the continuous fibroblast cell line Vero76. A procedure involving primary overlay with medium at pH 6.8, which was followed 2 to 3 days later with secondary overlay at neutral pH containing 1 microgram of emetine per ml and 20 micrograms of NaF per ml, resulted in visible plaques at 7 to 10 days postinfection. A single-step procedure involving overlay with medium containing 50 ng of dextran sulfate per ml also resulted in plaque formation within 8 days postinfection. These assays represent reproducible and inexpensive methods for evaluating the infectious titers of typhus group rickettsiae, cloning single plaque isolates, and testing the susceptibilities of rickettsiae to antibiotics. PMID:8818887

Policastro, P F; Peacock, M G; Hackstadt, T

1996-01-01

95

Effects of dietary flaxseed on atherosclerotic plaque regression.  

PubMed

Dietary flaxseed can retard the progression of atherosclerotic plaques. However, it remains unclear whether these antiatherogenic effects extend to plaque regression. In the present study, the therapeutic potential of dietary flaxseed on atherosclerotic plaque regression and vascular contractile function was evaluated using a novel rabbit model. Rabbits were randomly assigned to receive either a regular diet for 12 wk (group I) or a 1% cholesterol-supplemented diet for 4 wk followed by a regular diet for 8 wk (group II). The remaining experimental animals were treated as in group II but were fed for an additional 14 wk with either a regular diet (group III) or a 10% flaxseed-supplemented diet (group IV). Animals in group II showed clear evidence of plaque growth stabilization. Their vessels also exhibited significantly lower norepinephrine-induced contraction and an impaired relaxation response to acetylcholine compared with animals in group I. Dietary flaxseed supplementation resulted in a significant ?40% reduction in plaque formation (P = 0.033). Animals in both groups II and III displayed improved contraction and endothelium-dependent vessel relaxation. Dietary flaxseed is a valuable strategy to accelerate the regression of atherosclerotic plaques; however, flaxseed intervention did not demonstrate a clear beneficial effect on the vessel contractile response and endothelium-dependent vasorelaxation. PMID:23585134

Francis, Andrew A; Deniset, Justin F; Austria, Jose A; LaValleé, Renee K; Maddaford, Graham G; Hedley, Thomas E; Dibrov, Elena; Pierce, Grant N

2013-06-15

96

Phenotypic modulation of macrophages in response to plaque lipids  

PubMed Central

Purpose of review The accumulation of macrophages in the vascular wall is a hallmark of atherosclerosis. The biological properties of atherosclerotic plaque macrophages determine lesion size, composition and stability. In atherosclerotic plaques, macrophages encounter a microenvironment that is comprised of a variety of lipid oxidation products, each of which has diverse biological effects. In this review, we summarize recent advances in our understanding of the effects of plaque lipids on macrophage phenotypic polarization. Recent findings Atherosclerotic lesions in mice and in humans contain various macrophage phenotypes, which play different roles in mediating inflammation, the clearance of dead cells, and possibly resolution. Macrophages alter their phenotype and biological function in response to plaque lipids through the upregulation of specific sets of genes. Interaction of oxidized lipids with pattern recognition receptors and activation of the inflammasome by cholesterol crystals drive macrophages towards an inflammatory M1 phenotype. A new phenotype, Mox, develops when oxidized phospholipids activate stress response genes via Nrf2. Other lipid mediators such as nitrosylated-fatty acids and omega-3 fatty acid-derived products polarize plaque macrophages towards anti-inflammatory and proresolving phenotypes. Summary A deeper understanding of how lipids that accumulate in atherosclerotic plaques affect macrophage phenotype and function and thus atherosclerotic lesion development and stability will help to devise novel strategies for intervention. PMID:21841486

Adamson, Samantha; Leitinger, Norbert

2014-01-01

97

pH Heterogeneity of human and rabbit atherosclerotic plaques; a new insight into detection of vulnerable plaque  

Microsoft Academic Search

Background: Atherosclerotic plaques are heterogeneous with respect to inflammation, calcification, vascularity, oxygen, and temperature. We hypothesized that they also vary in pH and measured pH in living human carotid endarterectomized atherosclerotic plaques (CEA), Watanabe heritable hyperlipidemic (WHHL) rabbit aortas and human umbilical arteries (HUA). Methods and results: We measured pH of CEA of 48 patients, nine WHHL rabbit aortas and

Morteza Naghavi; Reji John; Sameh Naguib; Mir Said Siadaty; Roxana Grasu; K. C Kurian; W. Barry van Winkle; Babs Soller; Silvio Litovsky; Mohammad Madjid; James T Willerson; Ward Casscells

2002-01-01

98

Association between Variations in Coagulation System Genes and Carotid Plaque  

PubMed Central

Objective Genetic variation in coagulation and fibrinolysis may affect the development of subclinical atherosclerosis modifying the risk of stroke and cardiovascular disease. However, data on the relationship between subclinical atherosclerosis and genes involved in the coagulation system are sparse. The objective of this study is to examine the association between single nucleotide polymorphisms (SNPs) in coagulation system genes and subclinical carotid plaque phenotypes. Methods From the Genetic Determinants of Subclinical Carotid Disease study, 287 Dominicans were examined for carotid plaque presence, thickness, and surface irregularity by high-resolution B-mode carotid ultrasound. Logistic regression was used to test for association between 101 SNPs in 23 coagulation system genes and plaque phenotypes while controlling for age, sex, smoking, hypertension, dyslipidemia, and diabetes. Within gene haplotypes and interactions between genes were examined. A follow-up of SNPs in moderate to high (r2>0.25) linkage disequilibrium (LD) with those implicated in the discovery analysis (p?0.01) was performed in an independent sample of 301 Dominicans. Results The prevalence of carotid plaque (47% discovery; 46% follow-up) as well as the mean age (65±8 discovery; 65±9 follow-up) of the participants was similar in both datasets. Two genes (vWF and THBS1) were associated (p?0.01) with plaque size and surface irregularity. In followup, 5 SNPs in vWF were associated (p?0.05) with plaque size. SERPINE1 was an additional gene of interest in the haplotype and interaction analyses. Conclusions Variation in the vWF, THBS1, and SERPINE1 gene may play an important role in the pathogenesis of atherosclerotic plaque. PMID:22982001

Della-Morte, David; Beecham, Ashley; Dong, Chuanhui; Wang, Liyong; McClendon, Mark S.; Gardener, Hannah; Blanton, Susan H.; Sacco, Ralph L.; Rundek, Tatjana

2012-01-01

99

Thrombosis formation on atherosclerotic lesions and plaque rupture.  

PubMed

Atherosclerosis is a silent chronic vascular pathology that is the cause of the majority of cardiovascular ischaemic events. The evolution of vascular disease involves a combination of endothelial dysfunction, extensive lipid deposition in the intima, exacerbated innate and adaptive immune responses, proliferation of vascular smooth muscle cells and remodelling of the extracellular matrix, resulting in the formation of an atherosclerotic plaque. High-risk plaques have a large acellular lipid-rich necrotic core with an overlying thin fibrous cap infiltrated by inflammatory cells and diffuse calcification. The formation of new fragile and leaky vessels that invade the expanding intima contributes to enlarge the necrotic core increasing the vulnerability of the plaque. In addition, biomechanical, haemodynamic and physical factors contribute to plaque destabilization. Upon erosion or rupture, these high-risk lipid-rich vulnerable plaques expose vascular structures or necrotic core components to the circulation, which causes the activation of tissue factor and the subsequent formation of a fibrin monolayer (coagulation cascade) and, concomitantly, the recruitment of circulating platelets and inflammatory cells. The interaction between exposed atherosclerotic plaque components, platelet receptors and coagulation factors eventually leads to platelet activation, aggregation and the subsequent formation of a superimposed thrombus (i.e. atherothrombosis) which may compromise the arterial lumen leading to the presentation of acute ischaemic syndromes. In this review, we will describe the progression of the atherosclerotic lesion along with the main morphological characteristics that predispose to plaque rupture, and discuss the multifaceted mechanisms that drive platelet activation and subsequent thrombus formation. Finally, we will consider the current scientific challenges and future research directions. PMID:25156650

Badimon, L; Vilahur, G

2014-12-01

100

Raised Soluble P-Selectin Moderately Accelerates Atherosclerotic Plaque Progression  

PubMed Central

Soluble P-selectin (sP-selectin), a biomarker of inflammatory related pathologies including cardiovascular and peripheral vascular diseases, also has pro-atherosclerotic effects including the ability to increase leukocyte recruitment and modulate thrombotic responses in vivo. The current study explores its role in progressing atherosclerotic plaque disease. Apoe?/? mice placed on a high fat diet (HFD) were given daily injections of recombinant dimeric murine P-selectin (22.5 µg/kg/day) for 8 or 16 weeks. Saline or sE-selectin injections were used as negative controls. In order to assess the role of sP-selectin on atherothrombosis an experimental plaque remodelling murine model, with sm22?-hDTR Apoe?/? mice on a HFD in conjunction with delivery of diphtheria toxin to induce targeted vascular smooth muscle apoptosis, was used. These mice were similarly given daily injections of sP-selectin for 8 or 16 weeks. While plaque mass and aortic lipid content did not change with sP-selectin treatment in Apoe?/? or SM22?-hDTR Apoe?/? mice on HFD, increased plasma MCP-1 and a higher plaque CD45 content in Apoe?/? HFD mice was observed. As well, a significant shift towards a more unstable plaque phenotype in the SM22?-hDTR Apoe?/? HFD mice, with increased macrophage accumulation and lower collagen content, leading to a lower plaque stability index, was observed. These results demonstrate that chronically raised sP-selectin favours progression of an unstable atherosclerotic plaque phenotype. PMID:24846287

Andrews, Karen L.; Aprico, Andrea; Harris, Emma; Irvine, Jennifer C.; Jefferis, Ann-maree; Fang, Lu; Kanellakis, Peter; Bobik, Alex; Chin-Dusting, Jaye P. F.

2014-01-01

101

Macrophage-targeted photodynamic detection of vulnerable atherosclerotic plaque  

NASA Astrophysics Data System (ADS)

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 spectrofluorimetry. It may also be possible to use macrophage-targeted PDT to therapeutically modify inflammatory cell-laden VPs leading to plaque stabilization and reduction of sudden cardiovascular death.

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

102

Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging  

NASA Astrophysics Data System (ADS)

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 in human carotid artery plaques. It is shown in this capstone experiment that lipid filled regions in MRI correspond to areas of increased displacement in ARFI imaging while calcium and loose matrix components in MRI correspond to uniformly low displacements in ARFI imaging. This dissertation provides evidence to support that ARFI imaging may provide important prognostic and diagnostic information regarding stroke risk via measurements of plaque stiffness. More generally, the results have important implications for all acoustic radiation force based imaging methods used clinically.

Doherty, Joshua Ryan

103

Angiotensin Receptor Blockade With Candesartan Attenuates Atherosclerosis, Plaque Disruption, and Macrophage Accumulation Within the Plaque in a Rabbit Model  

PubMed Central

Background Little is known about whether direct angiotensin receptor blockade can reduce atherosclerosis and plaque disruption. This study evaluated the effect of angiotensin receptor blockade on both the development of atherosclerosis and the disruption of plaque in a modified Constantinides animal model. Methods and Results Twenty-eight New Zealand White rabbits underwent aortic balloon injury followed by a 1% cholesterol diet for 8 weeks. Thirteen rabbits received candesartan at 0.5 mg · kg?1 · d?1 beginning 2 days before aortic balloon injury and continued for the total 8 weeks of the cholesterol diet. The rabbits were then pharmacologically triggered and humanely killed, and their aortas were analyzed. The degree of atherosclerosis was determined by intima-media ratio of the infrarenal portion of the aorta. The frequency of intra-aortic thrombosis, a measure of plaque disruption, and the percentages of macrophage area and collagen-staining area of the plaque were determined. Candesartan-treated rabbits had less atherosclerosis (intima-media infrarenal aorta ratio of 1.18±0.08 versus 1.57±0.08 [mean±SEM] for the placebo group, P<0.001); fewer thrombi (3 of 13 versus 11 of 15; P<0.05); lower percentage area of macrophages to total plaque (18.8±2.7% versus 27±2.5%, P<0.05); and higher collagen to total plaque area (45±3% versus 35±2%, P<0.01). Conclusions These results demonstrate that angiotensin receptor blockade attenuates the degree of atherosclerosis and reduces both plaque disruption and macrophage accumulation while increasing collagen deposition in the aortas of this animal model. PMID:15451796

Perez, Alexandra S.; Nasser, Imad; Stewart, Robert; Vaidya, Anand; Al Ammary, Fawaz; Schmidt, Ben; Horowitz, Gary; Dolgoff, Jennifer; Hamilton, James; Quist, William C.

2010-01-01

104

Multimodal spectroscopy detects features of vulnerable atherosclerotic plaque  

NASA Astrophysics Data System (ADS)

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 ?-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.

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

2011-01-01

105

[Endemic pleural plaques and environmental factors (author's transl)].  

PubMed

In an agricultural town in Burgenland (Austria) we found an increased prevalence of pleural plaques. These calcifying thickenings of the pleura are related to minimal asbestos exposure such as is mesothelioma, but they cannot be regarded as a precancerosis. The increased occurrence of pleural plaques in this town of nearly 3500 inhabitants (in which during 1916 to 1945 asbestos was mined) we first found at the chest x-ray archives of a pulmologic hospital, then by mass radiography and blind comparison with control groups. A photofluoroscopy of 300 persons yielded 16 cases with definite pleural plaques (5.3%) among which were 4 cases with suspected asbestosis and another 14 cases with uncertain pleural plaques (4.7%). The 600 control persons showed no such radiological changes. Interviews wich persons detected for pleural plaques at mass radiography gave no indication that they had occupational asbestos exposure. But asbestos was detected in the soil of vineyards and in the dust of the houses. Asbestos was also detectable in the atmospheric dust by x-ray diffraction and scanning electron microscopic techniques. PMID:749422

Neuberger, M; Gründorfer, W; Haider, M; Königshofer, R; Müller, H W; Raber, A; Riedmüller, G; Schwaighofer, B

1978-12-01

106

Plaque Assay of Rickettsiae in a Mammalian Cell Line  

PubMed Central

Clear-cut and repeatable plaque assays were obtained for three rickettsiae of the spotted fever group (Rickettsia rickettsi, R. conori, and R. montana) in Vero cells used in a manner similar to that for arboviruses. In addition, three typhus group agents (R. typhi, R. canada, R. prowazeki) induced plaques in these cells. In preliminary tests Coxiella burneti (Nine Mile strain) failed to produce plaques. Comparable results were obtained in plastic flasks and plastic culture trays incubated in ambient air with or without addition of N-2-hydroxyethyl-piperazine-N?-2-ethanesulfinic acid buffer. Larger and more well defined R. rickettsi plaques were produced when cultures were overlaid with Leibovitz (L15) medium than with either medium 199 or Eagle medium. Phosphate-buffered saline containing bovine plasma albumin (fraction V), in contrast to brain heart infusion broth, as a diluent for preparing inocula consistently permitted development of larger and more numerous plaques with three agents: R. rickettsi, R. conori, and R. montana. When R. rickettsi and R. typhi were assayed in parallel in primary chicken embryo cultures and Vero cells, comparable results were obtained, but with R. canada results in Vero cells were superior. In contrast, R. prowazeki produced inconsistent results in Vero cells. Images PMID:4208640

Cory, J.; Yunker, C. E.; Ormsbee, R. A.; Peacock, M.; Meibos, H.; Tallent, G.

1974-01-01

107

Uniaxial tensile testing approaches for characterisation of atherosclerotic plaques.  

PubMed

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. PMID:24508324

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

2014-03-01

108

Infliximab in the treatment of plaque type psoriasis  

PubMed Central

Psoriasis is a chronic and immunomediated skin disease characterized by erythematous scaly plaques. Psoriasis affects approximately 1% to 3% of the Caucasian population. Tumor necrosis factor alpha (TNF-?) is a proinflammatory cytokine that plays a critical role in the pathogenesis of psoriasis. Infliximab is an anti-TNF-? drug widely used for the treatment of plaque type psoriasis and psoriatic arthritis. Controlled clinical trials demonstrated that infliximab is characterized by a high degree of clinical response in moderate to severe plaque psoriasis. Moreover infliximab showed rapid efficacy in nail psoriasis which represents a therapeutic challenge for dermatologists and a relevant source of distress for patients with plaque psoriasis. This anti-TNF-? has an encouraging safety profile, especially as long as physicians are watchful in prevention and early diagnosis of infections and infuse reactions. The efficacy, tolerability and safety profiles suggest infliximab as a suitable anti-psoriatic drug in the long-term treatment of a chronic disease such as plaque-type psoriasis. PMID:21436966

Saraceno, Rosita; Saggini, Andrea; Pietroleonardo, Lucia; Chimenti, Sergio

2009-01-01

109

Radiolabeled probes for imaging Alzheimer’s plaques  

NASA Astrophysics Data System (ADS)

Alzheimer's disease (AD) is a debilitating disease characterized by the presence of extra-cellular plaques and intra-cellular neurofibrillary tangles (NFTs) in the brain. The major protein component of these plaques is beta amyloid peptide (A?), a 40-42 amino acid peptide cleaved from amyloid precursor protein (APP) by ?-secretase and a putative ?-secretase. We radioiodinated quinoline derivatives (clioquinol and oxine) and evaluated them as potential amyloid imaging agents based on their ability to cross the blood brain barrier (BBB) and on their selectivity to metal binding sites on amyloid plaques. The uptake of theses tracers in the brains of normal swiss-webster mice was rapid and so was the clearance. Selectivity was demonstrated by higher binding to AD brain homogenates compared to normal brain. Autoradiographic studies demonstrated the localization of the tracers in the plaque regions of the AD brain sections as well as in liver tissue with amyloidosis. Further optimization and evaluations would likely lead to development of these molecules as AD plaque imaging agents.

Kulkarni, P. V.; Arora, V.; Roney, A. C.; White, C.; Bennett, M.; Antich, P. P.; Bonte, F. J.

2005-12-01

110

Low Copper and High Manganese Levels in Prion Protein Plaques  

PubMed Central

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. PMID:23435237

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

2013-01-01

111

The vulnerable coronary plaque: update on imaging technologies.  

PubMed

Several studies have been carried out on vulnerable plaque as the main culprit for ischaemic cardiac events. Historically, the most important diagnostic technique for studying coronary atherosclerotic disease was to determine the residual luminal diameter by angiographic measurement of the stenosis. However, it has become clear that vulnerable plaque rupture as well as thrombosis, rather than stenosis, triggers most acute ischaemic events and that the quantification of risk based merely on severity of the arterial stenosis is not sufficient. In the last decades, substantial progresses have been made on optimisation of techniques detecting the arterial wall morphology, plaque composition and inflammation. To date, the use of a single technique is not recommended to precisely identify the progression of the atherosclerotic process in human beings. In contrast, the integration of data that can be derived from multiple methods might improve our knowledge about plaque destabilisation. The aim of this narrative review is to update evidence on the accuracy of the currently available non-invasive and invasive imaging techniques in identifying components and morphologic characteristics associated with coronary plaque vulnerability. PMID:23803753

Rosa, Gian Marco; Bauckneht, Matteo; Masoero, Giovanni; Mach, François; Quercioli, Alessandra; Seitun, Sara; Balbi, Manrico; Brunelli, Claudio; Parodi, Antonello; Nencioni, Alessio; Vuilleumier, Nicolas; Montecucco, Fabrizio

2013-10-01

112

Laser speckle imaging of atherosclerotic plaques through optical fiber bundles.  

PubMed

Laser speckle imaging (LSI), a new technique that measures an index of plaque viscoelasticity, has been investigated recently to characterize atherosclerotic plaques. These prior studies demonstrated the diagnostic potential of LSI for detecting high-risk plaques and were conducted ex vivo. To conduct intracoronary LSI in vivo, the laser speckle pattern must be transmitted from the coronary wall to the image detector in the presence of cardiac motion. Small-diameter, flexible optical fiber bundles, similar to those used in coronary angioscopy, may be incorporated into an intravascular catheter for this purpose. A key challenge is that laser speckle is influenced by inter-fiber leakage of light, which may be exacerbated during bundle motion. In this study, we tested the capability of optical fiber bundles to transmit laser speckle patterns obtained from atherosclerotic plaques and evaluated the influence of motion on the diagnostic accuracy of fiber bundle-based LSI. Time-varying helium-neon laser speckle images of aortic plaques were obtained while cyclically moving the flexible length of the bundle to mimic coronary motion. Our results show that leached fiber bundles may reliably transmit laser speckle images in the presence of cardiac motion, providing a viable option to conduct intracoronary LSI. PMID:19021396

Nadkarni, Seemantini K; Bouma, Brett E; Yelin, Dvir; Gulati, Amneet; Tearney, Guillermo J

2008-01-01

113

Radionuclide imaging - A molecular key to the atherosclerotic plaque  

PubMed Central

Despite primary and secondary prevention, serious cardiovascular events like unstable angina or myocardial infarction still account for one third of all deaths worldwide. Therefore, identifying individual patients with vulnerable plaques at high risk for plaque rupture is a central challenge in cardiovascular medicine. Several non-invasive techniques, such as MRI, multislice computed tomography and electron beam tomography are currently being tested for their ability to identify such patients by morphological criteria. In contrast, molecular imaging techniques use radiolabeled molecules to detect functional aspects in atherosclerotic plaques by visualizing its biological activity. Based upon the knowledge about the pathophysiology of atherosclerosis, various studies in vitro, in vivo and the first clinical trials have used different tracers for plaque imaging studies, including radioactive labelled lipoproteins, components of the coagulation system, cytokines, mediators of the metalloproteinase system, cell adhesion receptors and even whole cells. This review gives an update on the relevant non-invasive plaque imaging approaches using nuclear imaging techniques to detect atherosclerotic vascular lesions. PMID:18582628

Langer, Harald Franz; Haubner, Roland; Pichler, Bernd Juergen; Gawaz, Meinrad

2008-01-01

114

Rayleigh mixture model for plaque characterization in intravascular ultrasound.  

PubMed

Vulnerable plaques are the major cause of carotid and coronary vascular problems, such as heart attack or stroke. A correct modeling of plaque echomorphology and composition can help the identification of such lesions. The Rayleigh distribution is widely used to describe (nearly) homogeneous areas in ultrasound images. Since plaques may contain tissues with heterogeneous regions, more complex distributions depending on multiple parameters are usually needed, such as Rice, K or Nakagami distributions. In such cases, the problem formulation becomes more complex, and the optimization procedure to estimate the plaque echomorphology is more difficult. Here, we propose to model the tissue echomorphology by means of a mixture of Rayleigh distributions, known as the Rayleigh mixture model (RMM). The problem formulation is still simple, but its ability to describe complex textural patterns is very powerful. In this paper, we present a method for the automatic estimation of the RMM mixture parameters by means of the expectation maximization algorithm, which aims at characterizing tissue echomorphology in ultrasound (US). The performance of the proposed model is evaluated with a database of in vitro intravascular US cases. We show that the mixture coefficients and Rayleigh parameters explicitly derived from the mixture model are able to accurately describe different plaque types and to significantly improve the characterization performance of an already existing methodology. PMID:21245004

Seabra, José C; Ciompi, Francesco; Pujol, Oriol; Mauri, Josepa; Radeva, Petia; Sanches, João

2011-05-01

115

Basal plate plaque: a novel organising placental thrombotic process.  

PubMed

In contrast to thrombi and haematomas at other body sites, thrombi in the placental intervillous space are not traditionally known to undergo organisation. This report presents 11 examples of a form of organising thrombotic process that develops as a plaque on the foetal aspect of the basal plate. Originally identified in the placenta of a foetus showing severe intrauterine growth restriction, further examples of this lesion, which we term a 'basal plate plaque', show a spectrum of placental involvement. Small lesions appear to occur at points of localised stasis at the basal plate (eg, at edges of anchoring villi or in small basal plate depressions). Large areas of involvement, as seen in the original case, may be pathological markers of more generalised disturbances in placental circulation or of hypercoagulability in the intervillous space. Large basal plate plaques may therefore prove to be diagnostically significant and should be reported. PMID:21252255

Fitzgerald, Brendan; Shannon, Patrick; Kingdom, John; Keating, Sarah

2011-08-01

116

Bifurcation analysis of a model for atherosclerotic plaque evolution  

NASA Astrophysics Data System (ADS)

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 (?). 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.

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

2014-06-01

117

Dosimetric study of the 15 mm ROPES eye plaque  

SciTech Connect

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.

Granero, D.; Perez-Calatayud, J.; Ballester, F.; Casal, E.; Frutos, J.M. de [Department of Atomic, Molecular and Nuclear Physics and IFIC, University of Valencia-CSIC, Dr. Moliner 50, E46100 Burjassot (Spain); Medical Physics Section, University Hospital, Av. Ramon y Cajal 3, E47011 Valladolid (Spain)

2004-12-01

118

Stress test evaluation of cobalt-enhanced nickel plaque electrodes  

NASA Astrophysics Data System (ADS)

The addition of cobalt to the surface of aerospace-quality sintered nickel plaque was observed to improve plate performance during a 5000 cycle stress test. A two-level, four-factor full factorial design matrix was established to compare the performance of cobalt-enhanced nickel plates with standard aerospace quality nickel plates during testing. The three other factors were loading level, current density during electrochemical impregnation and the concentration of KOH electrolyte. Regression analysis after 4000 cycles indicates that nickel plates fabricated from cobalt-enhanced plaque using a low current density during the electrochemical impregnation step provides the best performance during high rate charge/discharge applications.

Russell, Philip G.; Kuklinski, Jerry

119

Mobile floating carotid plaque post-trauma. Diagnosis and treatment.  

PubMed

We report the cases of two patients with mobile floating carotid plaques (MFCP). Two men were referred to us for carotid investigation after trauma. The duplex ultrasonography scan (DUS) showed the presence of a mobile floating plaque into the internal carotid artery associated with a stenosis of 40% and 65%, respectively (ECST criteria). Both patients were asymptomatic. Early CEA was performed (<24 h after admission). Intraoperatively it was confirmed the presence of MFCP. The patients were discharged without neurological symptoms two days postoperatively. At the follow-up the DUS showed the patency of the CEA without restenosis or residual flap. PMID:19151001

Ferrero, Emanuele; Gaggiano, Andrea; Ferri, Michelangelo; Nessi, Franco

2009-04-01

120

Method of making a light weight battery plaque  

NASA Technical Reports Server (NTRS)

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%.

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

1984-01-01

121

Dynamics of the Microglial/Amyloid Interaction Indicate a Role in Plaque Maintenance  

PubMed Central

Microglial cells aggregate around amyloid plaques in Alzheimer's disease, but, despite their therapeutic potential, various aspects of their reactive kinetics and role in plaque pathogenesis remain hypothetical. Through use of in vivo imaging and quantitative morphological measures in transgenic mice, we demonstrate that local resident microglia rapidly react to plaque formation by extending processes and subsequently migrating toward plaques, in which individual transformed microglia somata remain spatially stable for weeks. The number of plaque-associated microglia increased at a rate of almost three per plaque per month, independent of plaque volume. Larger plaques were surrounded by larger microglia, and a subset of plaques changed in size over time, with an increase or decrease related to the volume of associated microglia. Far from adopting a more static role, plaque-associated microglia retained rapid process and membrane movement at the plaque/glia interface. Microglia internalized systemically injected amyloid-binding dye at a much higher rate in the vicinity of plaques. These results indicate a role for microglia in plaque maintenance and provide a model with multiple targets for therapeutic intervention. PMID:18417708

Bolmont, Tristan; Haiss, Florent; Eicke, Daniel; Radde, Rebecca; Mathis, Chester A.; Klunk, William E.; Kohsaka, Shinichi; Jucker, Mathias

2008-01-01

122

Plaque: What It Is and How to Get Rid of It  

MedlinePLUS

... to the teeth. • Some types of plaque cause tooth decay. • Other types of plaque cause gum disease. Red, ... sweets, provide nutrients for the germs that cause tooth decay, as well as those that cause gum disease. ...

123

Mechanism of ceroid formation in atherosclerotic plaque: in situ studies combination of Raman and fluorescence spectroscopy  

E-print Network

Accumulation of the lipid-protein complex ceroid is a characteristic of atherosclerotic plaque. The mechanism of ceroid formation has been extensively studied, because the complex is postulated to contribute to plaque ...

Haka, Abigail S.

124

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

PubMed Central

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. PMID:7399699

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

1980-01-01

125

Quantification of coronary hemodynamics and plaque morphology using x-ray angiography and  

E-print Network

Quantification of coronary hemodynamics and plaque morphology using x-ray angiography arteries by fusion of data from x-ray angiography and intravascular ultrasound (IVUS) and elaborates angiography, intravascular ultrasound 1. Introduction Understanding the mechanisms of plaque development

Wahle, Andreas

126

Impact of local vessel curvature on the circumferential plaque distribution in coronary arteries  

E-print Network

the 3-D borders of the lumen/plaque and media/adventitia interfaces. Within each frame, plaque thickness with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple

Wahle, Andreas

127

Identification of amyloid plaques in retinas from Alzheimer's patients and noninvasive in vivo optical imaging of retinal plaques in a mouse model.  

PubMed

Noninvasive monitoring of ?-amyloid (A?) plaques, the neuropathological hallmarks of Alzheimer's disease (AD), is critical for AD diagnosis and prognosis. Current visualization of A? plaques in brains of live patients and animal models is limited in specificity and resolution. The retina as an extension of the brain presents an appealing target for a live, noninvasive optical imaging of AD if disease pathology is manifested there. We identified retinal A? plaques in postmortem eyes from AD patients (n=8) and in suspected early stage cases (n=5), consistent with brain pathology and clinical reports; plaques were undetectable in age-matched non-AD individuals (n=5). In APP(SWE)/PS1(?E9) transgenic mice (AD-Tg; n=18) but not in non-Tg wt mice (n=10), retinal A? plaques were detected following systemic administration of curcumin, a safe plaque-labeling fluorochrome. Moreover, retinal plaques were detectable earlier than in the brain and accumulated with disease progression. An immune-based therapy effective in reducing brain plaques, significantly reduced retinal A? plaque burden in immunized versus non-immunized AD mice (n=4 mice per group). In live AD-Tg mice (n=24), systemic administration of curcumin allowed noninvasive optical imaging of retinal A? plaques in vivo with high resolution and specificity; plaques were undetectable in non-Tg wt mice (n=11). Our discovery of A? specific plaques in retinas from AD patients, and the ability to noninvasively detect individual retinal plaques in live AD mice establish the basis for developing high-resolution optical imaging for early AD diagnosis, prognosis assessment and response to therapies. PMID:20550967

Koronyo-Hamaoui, Maya; Koronyo, Yosef; Ljubimov, Alexander V; Miller, Carol A; Ko, Minhee K; Black, Keith L; Schwartz, Michal; Farkas, Daniel L

2011-01-01

128

The Predominant Cultivable Flora of Carious Plaque and Carious Dentine  

Microsoft Academic Search

The quantitative recovery of bacteria from single localized sites, namely the interproximal plaque over a carious lesion and the underlying carious dentine, was undertaken. The samples were collected with minimal oxygen exposure and after dispersion and serial dilution were plated on mitis salivarius agar and various formulations of MM10 agar (a dilute trypticase, yeast extract medium). Higher total counts, Strep,

W. J. Loesche; S. A. Syed

1973-01-01

129

Atherothrombosis and Plaque Heterology: Different Location or a Unique Disease?  

Microsoft Academic Search

Formation of unstable plaques frequently results in atherothrombosis, the major cause for ischaemic stroke, myocardial infarction and peripheral arterial disease. Patients who have symptomatic thrombosis in one vascular bed are at increased risk of disease in other beds. However, the development of the disease in carotid, coronary and peripheral arteries may have different pathophysiology suggesting that more complex treatment protocols

M. Slevin; Q. Wang; A. Luque; Oriol Juan-Babot; J. Gaffney; P. Kumar; S. Kumar; L. Badimon; J. Krupinski

2008-01-01

130

Optical coherence tomography for imaging the vulnerable plaque  

NASA Astrophysics Data System (ADS)

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.

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

2006-03-01

131

Increased Expression of Wnt5a in Psoriatic Plaques  

Microsoft Academic Search

Psoriasis vulgaris is characterized by hyperproliferation and incomplete terminal differentiation of epidermal keratinocytes. Despite the established role of Wnt pathways in the regulation of stem cell proliferation and differentiation, they have not yet been associated with the pathophysiology of psoriasis. Here, we took biopsies from uninvolved and from lesional skin of 20 patients with plaque-type psoriasis. The biopsies were used

Joachim Reischl; Susanne Schwenke; Johanna M Beekman; Ulrich Mrowietz; Steffen Stürzebecher; Jürgen F Heubach

2007-01-01

132

7. VARIABLEANGLE LAUNCHER DEDICATION PLAQUE SHOWING JAMES H. JENNISON (LEFT), ...  

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

7. VARIABLE-ANGLE LAUNCHER DEDICATION PLAQUE SHOWING JAMES H. JENNISON (LEFT), AND W.H. SAYLOR (RIGHT), AT THE DEDICATION CEREMONY, May 7, 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

133

Detail, bridge plaque at balustrade of south abutment, from south, ...  

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

Detail, bridge plaque at balustrade of south abutment, from south, showing bridge construction in 1916 by city of Johnstown to design by Gustav A. Flink, designer and consulting engineer - Horner Street Bridge, Horner Street over Stonycreek River, Johnstown, Cambria County, PA

134

Amyloid Plaque Core Protein in Alzheimer Disease and Down Syndrome  

Microsoft Academic Search

We have purified and characterized the cerebral amyloid protein that forms the plaque core in Alzheimer disease and in aged individuals with Down syndrome. The protein consists of multimeric aggregates of a polypeptide of about 40 residues (4 kDa). The amino acid composition, molecular mass, and NH2-terminal sequence of this amyloid protein are almost identical to those described for the

Colin L. Masters; Gail Simms; Nicola A. Weinman; Gerd Multhaup; Brian L. McDonald; Konrad Beyreuther

1985-01-01

135

Composition and genesis of calcium deposits in atheroma plaques.  

PubMed

The composition of atheromatous plaque determines its progression toward rupture or thrombosis. Although its histopathological structure has been widely studied, little attention has been paid to its structural and chemical composition and even less to its mineral component. Thirty-three atheromatous plaques were obtained by carotid thromboendarterectomy. Three types of materials were observed under polarized light microscopy: apatite crystals in the form of glomeruli (dark with plane polarized illumination and greensh with cross-polarized illumination); fibrous-like cholesterol (uncolored or grayish with plane-polarized illumination); and amorphous organic material as brownish deposits. SEM-EDX analysis showed an abundance of phosphorus and calcium in sufficient quantities to form calcium phosphates, and appreciably reduced levels of sodium. X-ray diffraction results differentiated samples into three groups: group I with predominance of hydroxyapatite-type crystals, group II with crystalline material containing an amorphous component, and group III with wholly amorphous material. The most abundant mineral in atheromatous plaque is hydroxyapatite, on which crystals of cholesterol and lipid nuclei are deposited, stratifying the plaque into layers that reflect the different stages of its formation. The difference in calcium and sodium concentrations between arteries with and without atheromata may indicate an important relationship in the pathophysiological development of calcium deposits. PMID:24134634

Lara, María Jesús; Ros, Eduardo; Sierra, Manuel; Dorronsoro, Carlos; Aguilar, José

2014-05-01

136

Intracellular amyloid and the neuronal origin of Alzheimer neuritic plaques.  

PubMed

Genetic analysis of familial forms of Alzheimer's disease (AD) causally links the proteolytic processing of the amyloid precursor protein (APP) and AD. However, the specific type of amyloid and mechanisms of amyloid pathogenesis remain unclear. We conducted a detailed analysis of intracellular amyloid with an aggregation specific conformation dependent monoclonal antibody, M78, raised against fibrillar Aß42. M78 immunoreactivity colocalizes with Aß and the carboxyl terminus of APP (APP-CTF) immunoreactivities in perinuclear compartments at intermediate times in 10month 3XTg-AD mice, indicating that this represents misfolded and aggregated protein rather than normally folded APP. At 12months, M78 immunoreactivity also accumulates in the nucleus. Neuritic plaques at 12months display the same spatial organization of centrally colocalized M78, diffuse chromatin and neuronal nuclear NeuN staining surrounded by peripheral M78 and APP-CTF immunoreactivity as observed in neurons, indicating that neuritic plaques arise from degenerating neurons with intracellular amyloid immunoreactivity. The same staining pattern was observed in neuritic plaques in human AD brains, showing elevated intracellular M78 immunoreactivity at intermediate stages of amyloid pathology (Braak A and B) compared to no amyloid pathology and late stage amyloid pathology (Braak 0 and C, respectively). These results indicate that intraneuronal protein aggregation and amyloid accumulation is an early event in AD and that neuritic plaques are initiated by the degeneration and death of neurons by a mechanism that may be related to the formation of extracellular traps by neutrophils. PMID:25092575

Pensalfini, Anna; Albay, Ricardo; Rasool, Suhail; Wu, Jessica W; Hatami, Asa; Arai, Hiromi; Margol, Lawrence; Milton, Saskia; Poon, Wayne W; Corrada, Maria M; Kawas, Claudia H; Glabe, Charles G

2014-11-01

137

Interstellar Message Plaques: Application of White-Light Holography  

NASA Astrophysics Data System (ADS)

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.

Matloff, G. L.

2002-01-01

138

Evaluation of collagen in atherosclerotic plaques: the use of two coherent laser-based imaging methods  

Microsoft Academic Search

Acute coronary events such as myocardial infarction are frequently caused by the rupture of unstable atherosclerotic plaque.\\u000a Collagen plays a key role in determining plaque stability. Methods to measure plaque collagen content are invaluable in detecting\\u000a unstable atherosclerotic plaques. Recently, novel coherent laser-based imaging techniques, such as polarization-sensitive\\u000a optical coherence tomography (PSOCT) and laser speckle imaging (LSI) have been investigated,

Seemantini K. Nadkarni; Brett E. Bouma; Johannes de Boer; Guillermo J. Tearney

2009-01-01

139

Occurrence of pleural plaques in workers with exposure to mineral wool  

Microsoft Academic Search

The objective of this study was to investigate whether occurrence of pleural plaques is associated with exposure to mineral wool. The occurrence of pleural plaques on routine chest radiographs of 933 persons employed in the mineral wool manufacturing industry and 865 referents was compared. Twelve men from the mineral wool industry had pleural plaques, as against three of the referents

Bengt Järvholm; Gunnar Hillerdal; Anna-Karin Järliden; Alf Hansson; Bengt-Gunnar Lilja; Göran Tornling; Peter Westerholm

1995-01-01

140

Distribution of Inflammatory Cells in Atherosclerotic Plaques Relates to the Direction of Flow  

Microsoft Academic Search

Background—The distribution of macrophages and smooth muscle cells (SMCs) within atherosclerotic plaques is highly variable. This is clinically relevant because these cell types have opposite effects on the stability of atherosclerotic plaques. The present study was designed to investigate whether local variations in arterial flow over the plaque surface could relate to differences in the distribution of SMCs and macrophages

Maurits T. Dirksen; Allard C. van der Wal; Frank M. van den Berg; Chris M. van der Loos; Anton E. Becker

141

Mast cell infiltration in acute coronary syndromes: implications for plaque rupture  

Microsoft Academic Search

Objectives. To define the role of mast cells in plaque destabilization.Background. Inflammation is an essential feature of human coronary plaques. Macrophages and T lymphocytes are considered to contribute to destabilization of the plaques. The role of mast cells in this setting is less well studied. We therefore counted the mast cells in coronary atherectomy specimens from patients with chronic stable

Maija Kaartinen; Allard C. van der Wal; Chris M. van der Loos; Jan J. Piek; Karel T. Koch; Anton E. Becker; Petri T. Kovanen

1998-01-01

142

THE ROLE OF IRON PLAQUES IN IMMOBILIZING ARSENIC IN THE RICE-ROOT ENVIRONMENT  

E-print Network

THE ROLE OF IRON PLAQUES IN IMMOBILIZING ARSENIC IN THE RICE-ROOT ENVIRONMENT by Cecily Eiko Moyer that iron (Fe) plaques, consisting mainly of amorphous iron oxides, grow on the surfaces of the rice roots. Iron plaques sorb As, immobilizing the toxin, preventing it from absorption into the plant body

Sparks, Donald L.

143

THE ROLE OF IRON PLAQUES IN IMMOBILIZING ARSENIC IN THE RICE-ROOT ENVIRONMENT  

E-print Network

THE ROLE OF IRON PLAQUES IN IMMOBILIZING ARSENIC IN THE RICE-ROOT ENVIRONMENT by Cecily Eiko Moyer Rights Reserved #12;THE ROLE OF IRON PLAQUES IN IMMOBILIZING ARSENIC IN THE RICE-ROOT ENVIRONMENT ..............................................................................................11 2 FORMATION OF IRON PLAQUES AND ARSENIC SORPTION ON RICE (ORYZA SATIVA

Sparks, Donald L.

144

Monocytes and neutrophils expressing myeloperoxidase occur in fibrous caps and thrombi in unstable coronary plaques  

Microsoft Academic Search

BACKGROUND: Myeloperoxidase (MPO) -containing macrophages and neutrophils have been described at sites of plaque rupture. The presence of these cells in precursor lesions to acute rupture (thin cap atheroma, or vulnerable plaque) and within thrombi adjacent to ruptures has not been described, nor an association with iron-containing macrophages within unstable plaques. METHODS: We studied 61 acute ruptures, 15 organizing ruptures,

Fabio R Tavora; Mary Ripple; Ling Li; Allen P Burke

2009-01-01

145

The microglial phagocytic role with specific plaque types in the Alzheimer disease brain  

Microsoft Academic Search

Alzheimer disease (AD) involves glial inflammation associated with amyloid plaques. The role of the microglial cells in the AD brain is controversial, as it remains unclear if the microglia form the amyloid fibrils of plaques or react to them in a macrophage-phagocytic role. Also, it is not known why microglia are preferentially associated with some amyloid plaque types. This review

Michael R D’Andrea; Gregory M. Cole; March D. Ard

2004-01-01

146

Japanese Circulation Journal Vol.65, February 2001 he stability of atherosclerotic plaques depends greatly  

E-print Network

Japanese Circulation Journal Vol.65, February 2001 he stability of atherosclerotic plaques depends, are expressed in foam cell rich regions in atheromatous plaques.2 MMP-9, which degrades non-fibrillar collagen, is also known to be expressed in atherosclerotic plaques.3 Tumor necrosis factor receptor superfamily

Lee, Won-Ha

147

Controlling the angiogenic switch in developing atherosclerotic plaques: Possible targets for therapeutic intervention  

Microsoft Academic Search

Plaque angiogenesis may have an important role in the development of atherosclerosis. Vasa vasorum angiogenesis and medial infiltration provides nutrients to the developing and expanding intima and therefore, may prevent cellular death and contribute to plaque growth and stabilization in early lesions. However in more advanced plaques, inflammatory cell infiltration, and concomitant production of numerous pro-angiogenic cytokines may be responsible

Mark Slevin; Jerzy Krupinski; Lina Badimon

2009-01-01

148

Atherosclerotic Plaque at the Carotid Bifurcation: CT Angiographic Appearance with Histopathologic Correlation  

Microsoft Academic Search

BACKGROUND AND PURPOSE:The likelihood that carotid plaque will give rise to cerebral ischemia probably relates to the degree of arterial stenosis and to plaque morphology. The aim of this study was to assess whether features seen at CT angiography might be used to predict carotid plaque stability by comparing CT angiograms with histopathologic examinations of the carotid artery bifurcation. METHODS:

T. Barry Oliver; G. Alistair Lammie; Andrew R. Wright; Joanna Wardlaw; Sandi G. Patel; Russell Peek; C. Vaughan Ruckley; Donald A. Collie

149

Echo-Lucency of Computerized Ultrasound Images of Carotid Atherosclerotic Plaques Are Associated With Increased Levels of Triglyceride-Rich Lipoproteins as Well as Increased Plaque Lipid Content  

Microsoft Academic Search

Background—Echo-lucency of carotid atherosclerotic plaques on computerized ultrasound B-mode images has been associated with a high incidence of brain infarcts as evaluated on CT scans. We tested the hypotheses that triglyceride-rich lipoproteins in the fasting and postprandial state predict carotid plaque echo-lucency and that echo-lucency predicts a high plaque lipid content. Methods and Results—The study included 137 patients with neurological

Marie-Louise M. Grønholdt; Børge G. Nordestgaard; Britt M. Wiebe; Jens E. Wilhjelm; Henrik Sillesen

150

In vitro antiplaque activity of octenidine dihydrochloride (WIN 41464-2) against preformed plaques of selected oral plaque-forming microorganisms.  

PubMed Central

The antibacterial activity of octenidine dihydrochloride (WIN 41464-2) against intact preformed in vitro plaques of four indigenous oral plaque-forming microorganisms, Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii, was studied. Both absolute (plaque bactericidal index) and relative (chlorhexidine coefficient) indices of antiplaque efficacy were established. Octenidine dihydrochloride compared favorably with chlorhexidine digluconate with respect to overall antiplaque potency in this in vitro plaque bactericidal model. These data indicate that prudent selection of treatment concentration and duration and frequency of exposure should provide an effective means to aid in controlling dental caries and Actinomyces-associated disease in vivo. PMID:6847170

Slee, A M; O'Connor, J R

1983-01-01

151

A double layer plaque assay using spread plate technique for enumeration of bacteriophage MS2.  

PubMed

Bacteriophage MS2 is used widely as a model organism to estimate pathogenic virus survival in various environments, and is usually quantified by plaque assay. Although current plaque assays work well in enumeration of MS2 in environmental samples, quantification of MS2 calls for better visibility and higher consistency. In an attempt to improve the visibility and consistency of the current plaque assay, spread plate technique was introduced, instead of the pour plate technique used commonly in existing methods. Other parameters that influence the outcome of the plaque assay were also compared. Using spread plate technique resulted in an increase of plaque size by approximately 50% and contributed to a better visibility. Addition of supplements (glucose, CaCl2 and thiamine); reduction of agar thickness and hardness, also contributed to enhanced plaque visibility and increased plaque count. Among all the conditions tested, a supplemented thin bottom agar (10ml 1% agar) and a supplemented thin top agar (10ml 0.45% agar) with spread plate technique gave the maximum countable plaques with a minimum standard deviation. When compared to other methods, it produced significantly higher plaque count and lower variation. The optimized plaque assay significantly improved visibility and consistency of the existing plaque assay methods and could be used in quantification of MS2. PMID:24211298

Cormier, Jiemin; Janes, Marlene

2014-02-01

152

Plaque Rupture Complications in Murine Atherosclerotic Vein Grafts Can Be Prevented by TIMP-1 Overexpression  

PubMed Central

The current study describes the incidence and phenotype of plaque rupture complications in murine vein grafts. Since matrix metalloproteinases (MMPs) are highly involved in atherosclerotic plaque vulnerability and plaque rupture, we hypothesized that this model can be validated by overexpression of the MMP inhibitor TIMP-1. First we studied 47 vein grafts in hypercholesterolemic ApoE3*Leiden mice for the incidence of plaque complications. In 79% of these grafts, extensive lesions with plaque rupture complications like dissections, intraplaque hemorrhages or erosions with intramural thrombi were found. Next, in vivo Near-InfraRed-Fluorescence imaging demonstrated that electroporation mediated TIMP-1-overexpression reduced local MMP activity in vein grafts by 73% (p<0.01). This led to a 40% reduction in lesion-size after 28d (p?=?0.01) and a more stable lesion phenotype with significant more smooth muscle cells (135%), collagen (47%) and significant less macrophages (44%) and fibrin (55%) than controls. More importantly, lesions in the TIMP-1 group showed a 90% reduction of plaque complications (10/18 of control mice showed plaque complications versus 1/18 in TIMP-1 treated mice). Murine vein grafts are a relevant spontaneous model to study plaque stability and subsequent hemorrhagic complications, resulting in plaque instability. Moreover, inhibition of MMPs by TIMP-1-overexpression resulted in decreased plaque progression, increased stabilization and decreased plaque rupture complications in murine vein grafts. PMID:23071737

de Vries, Margreet R.; Niessen, Hans W. M.; Lowik, Clemens W. G. M.; Hamming, Jaap F.; Jukema, J. Wouter; Quax, Paul H. A.

2012-01-01

153

Coronary Plaque Type and Burden By Computed Tomography Angiography Without Association to C-Reactive Protein  

PubMed Central

Background: Contrast-enhanced computed tomography angiography (CTA) of the coronaries allows identification of plaques. Limited data exists on the relationship between C-reactive protein (CRP) and the plaque type or plaque burden detected by CTA. Aims: We studied relationship between CRP and coronary atherosclerosis. Materials and Methods: 92 patients without history of coronary disease underwent coronary CTA for chest pain. Coronary arteries were evaluated with each detected plaque labeled as calcified, noncalcified or mixed. Logarithmic transformation was done on CRP values for statistical analysis. Results: 1380 coronary segments were evaluated. The average age was 57 years (SE 1.0) and basal metabolic index (BMI) 28.9 kg/m2 (SE 0.5). Median CRP level was 2.75 mg/L (range 0.17-16.98). No association was found between CRP quartiles and plaque type. In stepwise multivariate analysis, only diabetes was associated with noncalcified plaque (P < 0.001). When calcified and mixed plaques were added to the model, age (P < 0.001), diabetes (P < 0.02), and statin use (P < 0.05) were associated with an increased number of plaques per subject. No association was found between log-CRP for any type of plaque. Conclusion: There was no association between CRP and plaque type by CTA. Lack of association is likely due to limited spatial resolution and underestimation of noncalcified plaque burden by CTA. PMID:25006560

Navaravong, Leenhapong; Steenson, Carol; Sigurdsson, Gardar

2014-01-01

154

Manganese and copper in the root plaque of Phragmites australis (cav. ) trin. ex steudel  

SciTech Connect

Manganese and copper were found in the iron oxide plaque on roots of Phragmites australis collected at six sampling sites in southern Quebec and Ontario, Canada. Manganese concentration in the plaque, like that of Fe, is correlated with Mn-bound-to-carbonates fraction of the soil/sediment. The Fe:Mn ratio of the plaque resemble the same ratio of Fe:Mn-bound-to-carbonates in the substrate. The ratio changes with environmental conditions, increasing with percentage of water and decreasing with pH. Plants located near flowing water accumulate more Mn (and Fe) in the plaque than plants in other habitats through the summer. Copper concentration in the plaque than plants in other habitats through the summer. Copper concentration in the plaque is pH-dependent and is positively correlated with the amount of Fe and Mn of the plaque, but appears to be related more closely to Mn.

St-Cyr, L.; Crowder, A.A. (Queen's Univ., Kingston, Ontario (Canada))

1990-04-01

155

Texture based segmentation method to detect atherosclerotic plaque from optical tomography images  

NASA Astrophysics Data System (ADS)

Optical coherence tomography (OCT) imaging has been widely employed in assessing cardiovascular disease. Atherosclerosis is one of the major cause cardio vascular diseases. However visual detection of atherosclerotic plaque from OCT images is often limited and further complicated by high frame rates. We developed a texture based segmentation method to automatically detect plaque and non plaque regions from OCT images. To verify our results we compared them to photographs of the vascular tissue with atherosclerotic plaque that we used to generate the OCT images. Our results show a close match with photographs of vascular tissue with atherosclerotic plaque. Our texture based segmentation method for plaque detection could be potentially used in clinical cardiovascular OCT imaging for plaque detection.

Prakash, Ammu; Hewko, Mark; Sowa, Michael; Sherif, Sherif

2013-06-01

156

The prevention and regression of atherosclerotic plaques: emerging treatments.  

PubMed

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

Kalanuria, Atul Ashok; Nyquist, Paul; Ling, Geoffrey

2012-01-01

157

Biofilms, a new approach to the microbiology of dental plaque  

Microsoft Academic Search

Dental plaque has the properties of a biofilm, similar to other biofilms found in the body and the environment. Modern molecular\\u000a biological techniques have identified about 1000 different bacterial species in the dental biofilm, twice as many as can be\\u000a cultured. Oral biofilms are very heterogeneous in structure. Dense mushroom-like structures originate from the enamel surface,\\u000a interspersed with bacteria-free channels

Jacob M. ten Cate

2006-01-01

158

Sequencing viral genomes from a single isolated plaque  

PubMed Central

Background Whole genome sequencing of viruses and bacteriophages is often hindered because of the need for large quantities of genomic material. A method is described that combines single plaque sequencing with an optimization of Sequence Independent Single Primer Amplification (SISPA). This method can be used for de novo whole genome next-generation sequencing of any cultivable virus without the need for large-scale production of viral stocks or viral purification using centrifugal techniques. Methods A single viral plaque of a variant of the 2009 pandemic H1N1 human Influenza A virus was isolated and amplified using the optimized SISPA protocol. The sensitivity of the SISPA protocol presented here was tested with bacteriophage F_HA0480sp/Pa1651 DNA. The amplified products were sequenced with 454 and Illumina HiSeq platforms. Mapping and de novo assemblies were performed to analyze the quality of data produced from this optimized method. Results Analysis of the sequence data demonstrated that from a single viral plaque of Influenza A, a mapping assembly with 3590-fold average coverage representing 100% of the genome could be produced. The de novo assembled data produced contigs with 30-fold average sequence coverage, representing 96.5% of the genome. Using only 10 pg of starting DNA from bacteriophage F_HA0480sp/Pa1651 in the SISPA protocol resulted in sequencing data that gave a mapping assembly with 3488-fold average sequence coverage, representing 99.9% of the reference and a de novo assembly with 45-fold average sequence coverage, representing 98.1% of the genome. Conclusions The optimized SISPA protocol presented here produces amplified product that when sequenced will give high quality data that can be used for de novo assembly. The protocol requires only a single viral plaque or as little as 10 pg of DNA template, which will facilitate rapid identification of viruses during an outbreak and viruses that are difficult to propagate. PMID:23742765

2013-01-01

159

Macrophage Activation in Atherosclerosis: Pathogenesis and Pharmacology of Plaque Rupture  

Microsoft Academic Search

Atherosclerosis is still an important disease. It accounts for 39% of deaths in the U.K. and 12 million U.S citizens have atherosclerosis-associated disease. Atherosclerosis may exert clinical effects by slow narrowing, producing stable angina or dramatic rupture, producing acute coronary syndromes such as unstable angina or myocardial infarction and death. Macrophages are abundant in ruptured atherosclerotic plaques. Macrophages are innate

J. J. Boyle

2005-01-01

160

Optical detection of structural changes in human carotid atherosclerotic plaque  

NASA Astrophysics Data System (ADS)

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 ?m. 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 spectroscopy is an effective method for evaluating ECM (collagen and elastin) associated with vascular remodeling despite the considerable variability in the plaque structure. Consistent regional differences were detected in the carotid specimens.

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

161

Modeling Plaque Fissuring and Dissection during Balloon Angioplasty Intervention  

Microsoft Academic Search

Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and\\/or dissection\\u000a occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization\\u000a of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment\\u000a site. We propose physical and finite element models, which are generally

T. Christian Gasser; Gerhard A. Holzapfel

2007-01-01

162

Complete Processing of Type III Collagen in Atherosclerotic Plaques  

Microsoft Academic Search

The extent of processing of type III collagen is assessed, and the proportions of type I and III collagens are estimated in atherosclerotic plaques obtained from the carotid artery, common femoral artery, and aorta. The fraction of type III collagen that had retained its amino-terminal propeptide (pN-collagen) was 42% in the soluble extract but only 0.0081% in the insoluble residue.

Michaela K. Bode; Martti Mosorin; Jari Satta; Leila Risteli; Tatu Juvonen; Juha Risteli

2010-01-01

163

The effect of two toothpastes on plaque and gingival inflamation.  

PubMed

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. PMID:8624228

Saxer, U P; Menghini, G; Bohnert, K J; Ley, F

1995-01-01

164

Quantitative evaluation of carotid arterial plaque surface irregularity  

NASA Astrophysics Data System (ADS)

Recent studies have demonstrated that atherosclerotic plaque surface morphology in the carotid arterial system represents an independent risk factor for embolus formation and subsequent cerebrovascular occlusive events. The primary aim of the current retrospective study is to enhance the clinical utility of this key finding by developing and evaluating objective, quantitative methods for characterizing plaque surface irregularity from Gadolinium-enhanced magnetic resonance angiography (MRA) studies. Nine metrics were analyzed for correlation with percent stenosis in 78 arteries from 43 patients with carotid artery disease. Most of the metrics comprised measurements obtained from a surface model of the stenotic lesion derived from the MRA via the Marching Cubes algorithm with application of the Isosurface Deformable Model. Percent stenosis was determined through real-time volume rendering of 3D MIP MRA studies in Vitrea2. Six of the analyzed metrics revealed significant correlation to percent stenosis (p<0.01). Reproducibility of all metrics was evaluated in a set of 14 randomly selected arteries from 13 patients by way of a single-trial, two-observer analysis. Six of the nine metrics demonstrated significant inter-observer reproducibility by way of single-factor ANOVA analysis (p<0.02). Collectively, the findings reported herein demonstrate an objective and reliable method for quantifying carotid plaque surface irregularity from standard MRA techniques with possible future clinical application in refining risk of ischemic cerebrovascular events and associated need for prophylactic intervention.

Robinson, Joshua; Brevetti, Lucy S.; Yim, Peter J.

2006-03-01

165

Supragingival plaque microbial analysis in reflection to caries experience  

PubMed Central

Background Dental caries develops as a result of the metabolism of carbohydrates by cariogenic bacteria present in a complex biofilm. The present study aimed to examine if bacteria in pooled supragingival plaque samples quantified using a “checkerboard DNA-DNA hybridization” based panel of caries-related bacteria, could reflect the caries experience in a manner similar to saliva samples analysed using a chair-side method in a previous investigation. Methods A total of 86 mothers and their children aged 4–6 years and 12–16 years old participated. Caries experience (DMFT/dmft; Decayed, Missing and Filled Teeth for permanent and primary teeth) was registered clinically and radiographically. Caries was recorded at the D3 level (caries into dentine). The D/d component was divided into three categories. A pooled supragingival plaque sample per participant was obtained from posterior approximal sites. Analyses of 15 bacterial species were performed using the checkerboard DNA-DNA hybridisation technique. Results No significant relationships were found between the bacterial scores and DMFT/dmft nor D/d groups. Conclusions Unlike the saliva samples and the chair-side method, interproximal pooled plaque samples analysed using the “checkerboard DNA-DNA hybridization technique” did not reveal any significant relations between the bacterial counts and the caries experience. PMID:23298235

2013-01-01

166

Sphenoid Wing en plaque meningiomas: Surgical results and recurrence rates  

PubMed Central

Background: Sphenoid wing en plaque meningiomas are a subgroup of meningiomas defined by its particular sheet-like dural involvement and its disproportionately large bone hyperostosis. En plaque meningiomas represent 2-9% of all meningiomas and they are mainly located in the sphenoid wing. Total surgical resection is difficult and therefore these tumors have high recurrence rates. Methods: Eighteen patients with sphenoid wing en plaque meningiomas surgically treated between January 1998 and December 2008 were included. Clinical, surgical, and follow-up data were retrospectively analyzed. Results: Mean age was 52.2 years and 83% were female. Five patients presented extension of dural component into the orbit and six patients presented cavernous sinus infiltration. Adjuvant radiation therapy was performed in three patients. After a mean follow-up of 4.6 years, five patients developed tumor recurrence - two patients were submitted to surgical treatment and the other three were submitted to radiation therapy. No patient presented recurrence after radiation therapy, whether performed immediately in the postoperative period or performed after recurrence. Patients without tumor extension to cavernous sinus or orbital cavity have the best prognosis treated with surgery alone. When tumor extension involves these locations the recurrence rate is high, especially in cases not submitted to adjuvant radiation therapy. Conclusion: Cavernous sinus and superior orbital fissure involvement are frequent and should be considered surgical limits. Postoperative radiation therapy is indicated in cases with residual tumor in these locations. PMID:23956929

Simas, Nuno M.; Farias, Joao Paulo

2013-01-01

167

Patient specific multiscale modelling for plaque formation and progression.  

PubMed

We present a three-dimensional model of plaque formation and progression that was tested in a set of patients who underwent coronary Computed Tomography angiography (CTA) for anginal symptoms. The 3D blood flow is described by the Navier-Stokes equations, together with the continuity equation. Mass transfer within the blood lumen and through the arterial wall is coupled with the blood flow and is modeled by a convection-diffusion equation. The Low Density Lipoprotein (LDL) transports in lumen of the vessel and through the vessel tissue (which has a mass consumption term) are coupled by Kedem-Katchalsky equations. The inflammatory process is modeled using three additional reaction-diffusion partial differential equations. A full three-dimensional model was created. Furthermore, features potentially affecting plaque growth, such as patient risk score, circulating biomarkers, localization and composition of the initial plaque, and coronary vasodilating capability were also investigated. The proof of concept of the model effectiveness was assessed 6 months after the baseline evaluation. PMID:23366529

Exarchos, T P; Sakellarios, A; Siogkas, P K; Fotiadis, D I; Milosevic, Z; Nikolic, D; Filipovic, N; Marraccini, P; Vozzi, F; Parodi, O

2012-01-01

168

Adherence of plaque components to different restorative materials.  

PubMed

This study compared the amount of artificial plaque synthesized in vitro by Streptococcus sobrinus on various dental materials using radioisotopes. In particular, plaque-retaining capacities of new types of ceramics were the focus of this study. Specimens were fabricated from the following materials (one amalgam alloy [Spherical-D], one casting gold alloy [Casting Gold TYPE I], one resin composite [Herculite XR] and three ceramics [Vita Celay Blanks, IPS Empress and Dicor MGC]). The amount of bacteria and glucans adhered on the specimens was measured after incubation for 24 hours at 37 degrees C with radio-labeled cariogenic bacteria and sucrose. This adhesion test was performed using two different surfaces with 600-grit roughness and clinical smoothness. Irrespective of the surface roughness, the least amount of plaque adhered to the ceramics. However, in the case of the resin composite and amalgam, the amount of bacteria and glucan adhesion decreased dramatically by polishing, though there were no statistically different changes in the amount of bacteria and glucans that adhered to the ceramics even after polishing. In general, the amount of adhered bacteria showed almost the same tendency as that of glucans. Although no statistical differences in the amount of bacteria and glucan adhesion were detected among the three ceramics investigated in this study, a lesser amount of bacteria and glucans adhered to them compared to the other materials. PMID:11504440

Kawai, K; Urano, M

2001-01-01

169

The Relationship Between Plaque pH, Plaque Acid Anion Profiles, and Oral Carbohydrate Retention After Ingestion of Several 'Reference Foods' by Human Subjects  

Microsoft Academic Search

The primary aim of this study was to rank several reference foods (apple drink, caramel, chocolate, cookie, skimmed milk powder, snack cracker, and wheat flake) according to their plaque pH response as monitored in a panel of 12 volunteers by the plaque-sampling method for comparison with data previously reported with other methods used to assess cariogenicity potential. Secondary experiments (using

M. W. J. Dodds; W. M. Edgar

1988-01-01

170

Pravastatin Treatment Increases Collagen Content and Decreases Lipid Content, Inflammation, Metalloproteinases, and Cell Death in Human Carotid Plaques Implications for Plaque Stabilization  

Microsoft Academic Search

Background—The clinical benefits of lipid lowering with statins are attributed to changes in plaque composition leading to lesion stability, but supporting clinical data from human studies are lacking. Therefore, we investigated the effect of 3 months of pravastatin treatment on composition of human carotid plaques removed during carotid endarterectomy. Methods and Results—Consecutive patients with symptomatic carotid artery stenosis received 40

Milita Crisby; Gunilla Nordin-Fredriksson; Prediman K. Shah; Juliana Yano; Jenny Zhu; Jan Nilsson

171

Spectral CT imaging of vulnerable plaque with two independent biomarkers  

NASA Astrophysics Data System (ADS)

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 keV). By performing simulations on a 3 cm diameter digital phantom, we successfully identified four materials that were simultaneously present in the mixture at different proportions and in multiple locations on the phantom. Quantitative analysis with a chest digital phantom showed that the results for iodine, gold and calcium were highly correlated with the known concentrations. The analysis revealed a potentially powerful technique for assessing a plaque's vulnerability with two independent markers. High correlation and low relative errors between calculated and known materials’ concentrations showed that the method is feasible. This technique can potentially have a high clinical impact.

Baturin, Pavlo; Alivov, Yahya; Molloi, Sabee

2012-07-01

172

Spectral CT imaging of vulnerable plaque with two independent biomarkers.  

PubMed

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 cm(2) 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 keV). By performing simulations on a 3 cm diameter digital phantom, we successfully identified four materials that were simultaneously present in the mixture at different proportions and in multiple locations on the phantom. Quantitative analysis with a chest digital phantom showed that the results for iodine, gold and calcium were highly correlated with the known concentrations. The analysis revealed a potentially powerful technique for assessing a plaque's vulnerability with two independent markers. High correlation and low relative errors between calculated and known materials' concentrations showed that the method is feasible. This technique can potentially have a high clinical impact. PMID:22683885

Baturin, Pavlo; Alivov, Yahya; Molloi, Sabee

2012-07-01

173

Retention of antimicrobial activity in plaque and saliva following mouthrinse use in vivo.  

PubMed

The aim of this study was to determine the contribution of plaque and saliva towards the prolonged activity, also called substantivity, of three antimicrobial mouthrinses (Listerine®, Meridol®, Crest Pro Health®), used in combination with a toothpaste (Prodent Coolmint®). Volunteers brushed for 4 weeks with a toothpaste without antimicrobial claims, while during the last 2 weeks half of the volunteers used an antimicrobial mouthrinse in addition to brushing. At the end of the experimental period, plaque and saliva samples were collected 6 h after oral hygiene, and bacterial concentrations and viabilities were determined. The contribution of plaque and saliva towards substantivity was assessed by combining plaque obtained after mechanical cleaning only with plaque and saliva obtained after additional use of an antimicrobial rinse. Subsequently, resulting viabilities of the combined plaques were determined. The viabilities of plaque samples after additional rinsing with mouthrinses were lower than of plaque obtained after mechanical cleaning only, regardless of the rinse involved. Moreover, plaque collected 6 h after rinsing with antimicrobial mouthrinses contained a surplus of antimicrobial activity. Only Listerine showed decreased viability in saliva, but none of the mouthrinses showed any residual antimicrobial activity in saliva. The findings indicate that plaque left behind after mechanical cleaning contributes to the prolonged substantivity of antimicrobial mouthrinses. PMID:20838045

Otten, M P T; Busscher, H J; van der Mei, H C; Abbas, F; van Hoogmoed, C G

2010-01-01

174

The importance of hemorrhage in the relationship between gross morphologic characteristics and cerebral symptoms in 376 carotid artery plaques.  

PubMed Central

In a prospective study 376 carotid artery plaques (275 symptomatic, 101 asymptomatic) were obtained from endarterectomies (184 unilateral and 96 bilateral) in 280 patients. The gross morphologic features of each plaque were noted at surgery and, together with the patient's clinical history, stored in computer memory. These data were analyzed in order to investigate the relationship of gross morphologic plaque characteristics with both the presence of cerebral symptoms and the degree of stenosis associated with the plaque. Ulceration was the most frequently observed of the five major gross plaque morphologic characteristics (46.0% of all plaques), but only intramural hemorrhage (30.6% of all plaques) was significantly more common in all symptomatic compared with all asymptomatic plaques (p less than 0.02). Hemorrhage was also the only gross characteristic significantly more common in focal symptomatic plaques when compared with either asymptomatic plaques (p less than 0.05) or nonfocal symptomatic plaques (p less than 0.01). When all the plaques were divided into three broad degrees of stenosis groups (0-39%, 40-69%, 70-99%) on the basis of angiographic data, only hemorrhage showed a significant correlation in incidence with increased degree of plaque stenosis, both when all plaques were considered (p less than 0.001) and when only symptomatic plaques were examined (p less than 0.001). The results indicate that intramural hemorrhage is the only carotid plaque gross morphologic characteristic significantly more frequent in symptomatic compared with asymptomatic plaques and the only characteristic significantly correlated with increased plaque size. These findings indicate that factors other than plaque ulceration and intraluminal thrombus play an important role in carotid plaque related cerebral symptoms. The data also raise questions concerning the unequivocal value of anticoagulant therapy in carotid artery disease, especially in highly stenotic lesions. Images Fig. 1. Fig. 1. PMID:6824372

Imparato, A M; Riles, T S; Mintzer, R; Baumann, F G

1983-01-01

175

Diffuse senile plaques occur commonly in the cerebellum in Alzheimer's disease.  

PubMed Central

Diffuse senile plaques are characterized by the presence of beta protein (beta P), also called A4 protein, in a dispersed form and the apparent lack of associated dystrophic neurites or reactive glial cells. They are the most common type of senile plaque found in the cerebral cortex in Alzheimer's disease (AD), Down's syndrome (DS), and normal aging. Here is reported the frequent presence of diffuse senile plaques in the molecular layer of cerebellar cortex in AD. Typical neuritic plaques were never detected in this location, making the cerebellar molecular cortex a useful site for the study of diffuse plaques because diffuse plaques in the cerebral cortex are intermingled with neuritic plaques. Diffuse cerebellar plaques were detected by modified Bielschowsky silver stain in 47 of 100 cases of clinically and pathologically diagnosed AD and in none of 40 aged demented and nondemented controls. They were immunolabeled by antibodies to purified AD meningeal or cortical beta P, and to a synthetic beta P but not by two antibodies to the carboxyl- and amino-termini of the beta protein precursor (beta PP), which label a subgroup of cerebral cortical plaques. This latter result suggests that the beta P deposited in the cerebellar molecular layer may be derived from a form of the beta PP from which the carboxyl and amino terminal regions of the precursor have already been cleaved. Diffuse cerebellar plaques were not recognized by antibodies to neurofilaments, tau, and PHF, all of which detect dystrophic neurites in cerebral cortical neuritic plaques. Also, no association of reactive astrocytes or microglial cells with diffuse cerebellar plaques was observed. Thus, diffuse cerebellar plaques represent multifocal deposits of noncompacted beta P that cause little or no morphologic reaction in their microenvironment. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:2675616

Joachim, C. L.; Morris, J. H.; Selkoe, D. J.

1989-01-01

176

Rosuvastatin improves plaque morphology in cerebral embolism patients with normal low-density lipoprotein and severe aortic arch plaque.  

PubMed

The effect of rosuvastatin was investigated on complicated aortic arch plaque (CAP) morphology and lipid profiles in acute cerebral embolism (CE) patients with normal low-density lipoprotein-cholesterol (LDL-c) levels. Transesophageal echocardiography (TEE) studies were performed in 56 consecutive CE patients with LDL-c less than 140 mg/dL who were not taking lipid-lowering agents at baseline. CAP observed by TEE was defined as the presence of greater than 4-mm diameter, ulcerated, or mobile aortic plaque. Patients were divided into those with CAP versus without CAP (group A, n=24, age 69±8 years) and without CAP (group B, n=32, age 62±10 years). Of the 24 group A patients, 18 received 5 mg/d of rosuvastatin for 6 months and had follow-up TEE studies. In Group A, the baseline values of high-density lipoprotein-cholesterol (HDL-c) and apolipoprotein A-1 (ApoA-1) were significantly lower than in Group B (44±15 versus 55±15 mg/dL, P=.0059; 103±19 versus 137±25 mg/dL, P=.0006, respectively) and age and serum high-sensitivity C-reactive protein concentration were significantly higher (69±8 vs. 62±10 years, P=.0080; 2.34±3.05 vs. 0.67±1.00 mg/dL, P=.0054, respectively). By multivariate logistic regression analysis, ApoA-1 was shown to be an independent predictor of CAP (odds ratio=.894, 95% confidence intervals .800-.996, P=.0483). In the 18 group A patients receiving rosuvastatin for 6 months, aortic arch plaque diameter and serum LDL-c were significantly decreased (5.8±2.2 to 5.1±2.1 mm, P=.0377; 110±23 to 81±23 mg/dL, P=.0008, respectively), whereas serum HDL-c and ApoA-1 concentrations were significantly increased (42±8 to 52±9 mg/dL, P=.0002; 109±22 to 135±15 mg/dL, P=.0002, respectively). Plaques were morphologically improved in 11 patients, unchanged in 6, and worsened in 1. These data suggest that rosuvastatin improves plaque morphology concomitant with improving lipid profiles in CE patients with normal LDL-c levels. PMID:24739590

Kaneko, Kazuyoshi; Saito, Hiroki; Takahashi, Tetsuya; Kiribayashi, Nobuyuki; Omi, Koki; Sasaki, Toshiki; Niizeki, Takeshi; Sugawara, Shigeo; Akasaka, Masahiro; Kubota, Isao

2014-07-01

177

Non-invasive measurement of coronary plaque from coronary CT angiography and its clinical implications.  

PubMed

Coronary CT angiography (CTA) is increasingly used worldwide for direct, non-invasive evaluation of the coronary arteries. Advances in computed tomography (CT) technology over the last decade have enabled such reliable imaging of the coronary arteries. Beyond arterial stenosis, coronary CTA also permits assessment of atherosclerotic plaque (including plaque burden) and coronary artery remodeling, previously only achievable through invasive means. It has been shown that coronary plaque volumes for non-calcified and mixed plaques and the arterial remodeling index, correlate closely with invasive intravascular ultrasound. Several studies have also shown a strong relationship of adverse plaque features imaged by coronary CTA with acute coronary syndrome, all-cause death, major adverse cardiovascular events and myocardial ischemia. The aim of this review is to summarize current methods for quantitative measurement of atherosclerotic plaque features from coronary CTA and to discuss their clinical implications. PMID:23984930

Dey, Damini; Schuhbaeck, Annika; Min, James K; Berman, Daniel S; Achenbach, Stephan

2013-08-01

178

Numbers and types of asbestos fibers in subjects with pleural plaques.  

PubMed Central

The authors analyzed asbestos fibers in lung samples from 20 subjects with pleural plaques discovered on autopsy and compared the findings to their previous analyses of lungs from subjects with little or no asbestos exposure and no plaques. Sixteen of the subjects with plaques had a history of exposure to asbestos. The authors used electron-optical methods and energy-dispersive x-ray spectroscopy to investigate the structure, diffraction patterns, and chemical composition of the asbestos fibers. The subjects with plaques had significantly higher median concentrations than the control subjects for amosite and crocidolite fibers (P less than 0.01) but not for the other fiber types. Minimal microscopic asbestosis was present in the 3 subjects who had the highest amosite concentrations. In the subjects with typical plaques, a history of asbestos exposure, and more fibers than in the control population, the relation of the plaques to asbestos was confirmed; for others, it was uncertain. PMID:7124907

Warnock, M. L.; Prescott, B. T.; Kuwahara, T. J.

1982-01-01

179

Human Serum Albumin Cys34 Oxidative Modifications following Infiltration in the Carotid Atherosclerotic Plaque  

PubMed Central

Objectives. To evaluate if the prooxidant environment present in atherosclerotic plaque may oxidatively modify filtered albumin. Methods. Fluorescein-5-maleimide labelled plasma samples and plaque extracts from 27 patients who had undergone carotid endarterectomy were analysed through nonreducing SDS-PAGE for albumin-Cys34 oxidation. Furthermore, degree and pattern of S-thiolation in both circulating and plaque-filtered albumin were assayed. Results. Albumin filtered in the atherosclerotic plaque showed higher levels of Cys34 oxidative modifications than the corresponding circulating form as well as different patterns of S-thiolation. Conclusions. Data indicate that the circulating albumin, once filtered in plaque, undergoes Cys34 oxidative modifications and demonstrate for the first time that albumin is a homocysteine and cysteinylglycine vehicle inside the plaque environment. PMID:24738021

Zinellu, Angelo; De Muro, Pierina; Carru, Ciriaco; Spirito, Rita; Guarino, Anna

2014-01-01

180

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

NASA Astrophysics Data System (ADS)

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.

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

2011-07-01

181

Membrane Type 1 Matrix Metalloproteinase Expression in Human Atherosclerotic Plaques Evidence for Activation by Proinflammatory Mediators  

Microsoft Academic Search

Background—Matrix metalloproteinases (MMPs) are expressed in atherosclerotic plaques, where in their active form, they may contribute to vascular remodeling and plaque disruption. In this study, we tested the hypothesis that membrane type 1 MMP (MT1-MMP), a novel transmembrane MMP that activates pro-MMP-2 (gelatinase A), is expressed in human atherosclerotic plaques and that its expression is regulated by proinflammatory molecules. Methods

Tripathi B. Rajavashisth; Xiao-Ping Xu; Stefan Jovinge; Simcha Meisel; Xiao-Ou Xu; Ning-Ning Chai; Michael C. Fishbein; Sanjay Kaul; Bojan Cercek; Behrooz Sharifi; Prediman K. Shah

182

Structure-dependent dynamic mechanical behavior of fibrous caps from human atherosclerotic plaques  

Microsoft Academic Search

Background. Although thrombosis associated witha fissured atherosclerotic plaque is believed tobethemostcommon causeofacute coronarysyndromes, theunderlying factors that trigger plaque rupture arecurrently unknown. However, themechanical behavior oftheplaque isprobably ofcritical importance. Methods andResults. Totestthehypothesis thatthemechanical properties ofa plaque are dependent on itscomposition and,inparticular, thatthestiffness offibrous capschanges within therangeoffrequencies carried bya physiological pressurewave,thestress-strain relation was studied in27fibrous capsandrelated totheunderlying histological structure of thefibrous cap.Fibrous

Richard T. Lee; Alan J. Grodzinsky; Eliot H. Frank; Roger D. Kamm; Fj Schoen

2010-01-01

183

Humanin, a Cytoprotective Peptide, Is Expressed in Carotid Artherosclerotic Plaques in Humans  

Microsoft Academic Search

ObjectiveThe mechanism of atherosclerotic plaque progression leading to instability, rupture, and ischemic manifestation involves oxidative stress and apoptosis. Humanin (HN) is a newly emerging endogenously expressed cytoprotective peptide. Our goal was to determine the presence and localization of HN in carotid atherosclerotic plaques.Methods and ResultsPlaque specimens from 34 patients undergoing carotid endarterectomy were classified according to symptomatic history. Immunostaining combined

David G. Zacharias; Sung Gyun Kim; Alfonso Eirin Massat; Adi R. Bachar; Yun K. Oh; Joerg Herrmann; Martin Rodriguez-Porcel; Pinchas Cohen; Lilach O. Lerman; Amir Lerman

2012-01-01

184

Effects of intima stiffness and plaque morphology on peak cap stress  

Microsoft Academic Search

Background  Rupture of the cap of a vulnerable plaque present in a coronary vessel may cause myocardial infarction and death. Cap rupture\\u000a occurs when the peak cap stress exceeds the cap strength. The mechanical stress within a cap depends on the plaque morphology\\u000a and the material characteristics of the plaque components. A parametric study was conducted to assess the effect of

Ali C Akyildiz; Lambert Speelman; Harald van Brummelen; Miguel A Gutiérrez; Renu Virmani; Aad van der Lugt; Anton FW van der Steen; Jolanda J Wentzel; Frank JH Gijsen

2011-01-01

185

Manganese and copper in the root plaque of Phragmites australis (cav. ) trin. ex steudel  

Microsoft Academic Search

Manganese and copper were found in the iron oxide plaque on roots of Phragmites australis collected at six sampling sites in southern Quebec and Ontario, Canada. Manganese concentration in the plaque, like that of Fe, is correlated with Mn-bound-to-carbonates fraction of the soil\\/sediment. The Fe:Mn ratio of the plaque resemble the same ratio of Fe:Mn-bound-to-carbonates in the substrate. The ratio

LOUISE ST-CYR; ADELE A. CROWDER

1990-01-01

186

Comparison of PCR and Plaque Assay for Detection and Enumeration of Coliphage in Polluted Marine Waters  

Microsoft Academic Search

the plaque assay and a reverse transcriptase (RT) PCR technique for F1-specific coliphage. The coliphage levels detected by the plaque assay averaged 1.90 3 104 PFU\\/100.0 ml. Using a most probable number (MPN) PCR approach, the levels averaged 2.40 3 106 MPN-PCR units\\/100.0 ml. Two samples were positive by RT-PCR but negative by plaque assay, and 12 samples were positive

JOAN B. ROSE; XINTING ZHOU; DALE W. GRIFFIN; JOHN H. PAUL

1997-01-01

187

The relationship between plaque pH, plaque acid anion profiles, and oral carbohydrate retention after ingestion of several 'reference foods' by human subjects.  

PubMed

The primary aim of this study was to rank several reference foods (apple drink, caramel, chocolate, cookie, skimmed milk powder, snack cracker, and wheat flake) according to their plaque pH response as monitored in a panel of 12 volunteers by the plaque-sampling method for comparison with data previously reported with other methods used to assess cariogenicity potential. Secondary experiments (using subsets of the panel of subjects) were undertaken in an attempt to elucidate some of the reasons for the observed plaque pH changes. Oral carbohydrate retention was measured at a single time period after food use as total anthrone-positive carbohydrate material, and as specific acidogenic sugars by gas-liquid chromatography after gel-exclusion chromatography. The concentrations of acid anions in the plaque fluid after food consumption were measured by isotachophoresis eight min after food use. According to the plaque pH response, apple-flavored fruit drink and chocolate were the most acidogenic foods and skimmed milk powder the least acidogenic. There were significant correlations (p less than 0.05) between the plaque pH data and lactate-plus-acetate concentrations in plaque fluid, but the correlations between the pH data and any of the carbohydrate retention parameters were not significant. PMID:3163354

Dodds, M W; Edgar, W M

1988-05-01

188

Staining and calculus formation after 0.12% chlorhexidine rinses in plaque-free and plaque covered surfaces: a randomized trial  

PubMed Central

Objectives Studies concerning side effects of chlorhexidine as related to the presence of plaque are scarce. The purpose of this study was to compare the side effects of 0.12% chlorhexidine gluconate (CHX) on previously plaque-free (control group) and plaque-covered surfaces (test group). Methods This study had a single-blind, randomized, split-mouth, 21 days-experimental gingivitis design, including 20 individuals who abandoned all mechanical plaque control methods during 25 days. After 4 days of plaque accumulation, the individuals had 2 randomized quadrants cleaned, remaining 2 quadrants with plaque-covered dental surfaces. On the fourth day, the individuals started with 0.12% CHX rinsing lasting for 21 days. Stain index intensity and extent as well as calculus formation were evaluated during the experimental period. Results Intergroup comparisons showed statistically higher (p<0.05) stain intensity and extent index as well as calculus formation over the study in test surfaces as compared to control surfaces. Thus, 26.19% of test surfaces presented calculus, whereas calculus was observed in 4.52% in control surfaces. Conclusion The presence of plaque increased 0.12% CHX side effects. These results strengthen the necessity of biofilm disruption prior to the start of CHX mouthrinses in order to reduce side effects. PMID:21085810

ZANATTA, Fabrício Batistin; ANTONIAZZI, Raquel Pippi; RÖSING, Cassiano Kuchenbecker

2010-01-01

189

A classic collaboration: Michael Davies on plaque vulnerability.  

PubMed

The British Heart Foundation sponsors the Michael Davies Young Investigator Award, and at its presentation in the Spring of 2009 two collaborators of Michael Davies spoke regarding their experiences on the Plaque Vulnerability project with him. This was to provide the winner and other nominees for the award, and colleagues at the meeting, descriptions of collaborating with Michael to sustain more than his name in association with the award. This article is an expansion of the personal reminiscences given at the time as a tribute to him, and to provide an inside story of how collaboration with such a prominent cardiac pathologist worked. PMID:22196149

Born, G V R; Richardson, P D

2012-02-01

190

Sphenoid Wing Meningioma en Plaque: A Clinical Review  

Microsoft Academic Search

Summary.\\u000a Summary.  \\u000a \\u000a \\u000a Objective.   To review the role of craniofacial resection and reconstruction in the treatment of patients with sphenoid wing meningioma\\u000a en plaque.\\u000a \\u000a \\u000a \\u000a Design:   15 patients were reviewed. The presenting features, operative details and complications were documented. The adequacy of\\u000a resection was reviewed and postoperative scans were analyzed to assess orbital reconstruction. Patients were assessed regarding\\u000a aesthetics and craniofacial function.

S. Honeybul; G. Neil-Dwyer; D. A. Lang; B. T. Evans; D. W. Ellison

2001-01-01

191

Plaque assay and cloning of scrub typhus rickettsiae in irradiated L-929 cells.  

PubMed Central

It was demonstrated that gamma-irradiated L-929 cells support plaque formation by three strains of Rickettsia tsutsugamushi and representative species of the spotted fever and typhus group rickettsiae. Sensitivity of the plaque assay for detection of viable scrub typhus rickettsiae was similar to that achieved with intraperitoneal inoculation of random-bred mice. The concentration of irradiated cells and the temperature and length of incubation were all found to affect plaque size. A technique combining terminal dilution and plaque purification was used to obtain clones of three strains of scrub typhus rickettsiae. Images PMID:69632

Oaks, S C; Osterman, J V; Hetrick, F M

1977-01-01

192

Molecular imaging of plaques in coronary arteries with PET and SPECT  

PubMed Central

Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lumen stenosis which is often used as an indicator for determining the severity of coronary artery disease. However, the degree of coronary lumen stenosis is not often related to compromising myocardial blood flow, as most of the cardiac events that are caused by atherosclerotic plaques are the result of vulnerable plaques which are prone to rupture. Thus, identification of vulnerable plaques in coronary arteries has become increasingly important to assist identify patients with high cardiovascular risks. Molecular imaging with use of positron emission tomography (PET) and single photon emission computed tomography (SPECT) has fulfilled this goal by providing functional information about plaque activity which enables accurate assessment of plaque stability. This review article provides an overview of diagnostic applications of molecular imaging techniques in the detection of plaques in coronary arteries with PET and SPECT. New radiopharmaceuticals used in the molecular imaging of coronary plaques and diagnostic applications of integrated PET/CT and PET/MRI in coronary plaques are also discussed.

Sun, Zhong-Hua; Rashmizal, Hairil; Xu, Lei

2014-01-01

193

Quantitative assessment of carotid plaque surface irregularities and correlation to cerebrovascular symptoms  

PubMed Central

Background The purpose of this study was to determine whether surface irregularities measured from ultrasound images of carotid artery plaques and quantified using a novel method, correlate with the presence of ipsilateral hemispheric cerebrovascular symptoms. Methods A plaque surface irregularity index (SII) was measured in 47 carotid artery plaques (32 subjects, stenosis range 10% -95%, 49% symptomatic) using ultrasound image sequences spanning several cardiac cycles. The differences in the distribution of SII in plaques with ipsilateral hemispheric symptoms versus those without symptoms and the correlation between the SII of plaques and the degrees of stenosis of the corresponding arteries were assessed. Diagnostic performance of plaque SII was evaluated on its own and in combination with the degree of stenosis. Results The mean SII was significantly greater for plaques with ipsilateral hemispheric symptoms (1.89 radians/mm) than for asymptomatic plaques (1.67 radians/mm, p?=?0.03). There was no statistically significant association between the SII and the degree of stenosis (p?=?0.30). SII predicted the presence of cerebrovascular symptoms with an accuracy of 66% (sensitivity 65%, specificity 67%) on its own and with an accuracy of 83% (sensitivity 96%, specificity 71%) in combination with the degree of stenosis. Conclusions Quantitative assessment of carotid plaque surface irregularities using a novel SII parameter correlates with the presence ipsilateral hemispheric cerebrovascular symptoms and may increase diagnostic performance beyond that provided by the degree of stenosis. PMID:24195596

2013-01-01

194

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

PubMed

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. PMID:12789977

Dudgeon, Douglas J; Berg, Joel

2002-07-01

195

Molecular imaging of plaques in coronary arteries with PET and SPECT.  

PubMed

Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lumen stenosis which is often used as an indicator for determining the severity of coronary artery disease. However, the degree of coronary lumen stenosis is not often related to compromising myocardial blood flow, as most of the cardiac events that are caused by atherosclerotic plaques are the result of vulnerable plaques which are prone to rupture. Thus, identification of vulnerable plaques in coronary arteries has become increasingly important to assist identify patients with high cardiovascular risks. Molecular imaging with use of positron emission tomography (PET) and single photon emission computed tomography (SPECT) has fulfilled this goal by providing functional information about plaque activity which enables accurate assessment of plaque stability. This review article provides an overview of diagnostic applications of molecular imaging techniques in the detection of plaques in coronary arteries with PET and SPECT. New radiopharmaceuticals used in the molecular imaging of coronary plaques and diagnostic applications of integrated PET/CT and PET/MRI in coronary plaques are also discussed. PMID:25278976

Sun, Zhong-Hua; Rashmizal, Hairil; Xu, Lei

2014-09-01

196

[Near-infrared spectroscopy (NIRS), new intracoronary imaging technique of unstable coronary plaque].  

PubMed

Acute coronary syndrome may develop in the background of hemodynamically non-significant coronary artery disease. It may be caused by the presence of "vulnerable plaque", which is characterized by the lipid rich core and thin fibrous cap content. NIRS - near infrared spectroscopy - is a morphological imaging method allowing determining atherosclerotic plaque cholesterol burden. Information about the chemical composition may contribute to "high risk" plaque early identification and subsequent optimal interventional strategy. The first experience with the clinical implementation of this novel method is demonstrated in a case report. Key words: acute coronary syndrome - chemogram - intravascular imaging - NIRS - vulnerable plaque. PMID:24974760

Ondrúš, Tomáš; Ka?ovský, Jan; Poloczek, Martin; Miklík, Roman; Bo?ek, Otakar; Je?ábek, Petr; Kala, Petr

2014-01-01

197

Evidence-based control of plaque and gingivitis.  

PubMed

Most adults brush and floss inadequately, and constant education and/or reinforcement is often required. Bacteria are usually left behind with mechanical oral health routines, and chemotherapeutic agents may have a key role as adjuncts to daily home-care. To date, two antiseptic mouthwashes have received the ADA Seal of Acceptance: Peridex (Zila Pharmaceuticals, Phoenix, AZ, USA; CHX, chlorhexidine) and Listerine (Pfizer Consumer Healthcare, Morris Plains, NJ, USA; essential oil (EO) mouthwash). CHX has a strong affinity for tooth and tissue surfaces, but can cause brown staining on the teeth and tongue. Patients must also wait until all traces of toothpaste are removed before rinsing with CHX. Long-term use of an EO mouthwash is microbiologically safe, with no changes observed in the bacterial composition of supragingival plaque, and no evidence of antimicrobial resistance. A number of trials have demonstrated the long-term plaque- and gingivitis-reducing properties of both CHX and EO mouthwashes. These studies clearly demonstrate that these agents have lasting efficacy, and can access hard-to-reach areas. PMID:12787197

Santos, A

2003-01-01

198

Performance of digital RGB reflectance color extraction for plaque lesion  

NASA Astrophysics Data System (ADS)

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.

Hashim, Hadzli; Taib, Mohd Nasir; Jailani, Rozita; Sulaiman, Saadiah; Baba, Roshidah

2005-01-01

199

How Does Calcification Influence Plaque Vulnerability? Insights from Fatigue Analysis  

PubMed Central

Background. Calcification is commonly believed to be associated with cardiovascular disease burden. But whether or not the calcifications have a negative effect on plaque vulnerability is still under debate. Methods and Results. Fatigue rupture analysis and the fatigue life were used to evaluate the rupture risk. An idealized baseline model containing no calcification was first built. Based on the baseline model, we investigated the influence of calcification on rupture path and fatigue life by adding a circular calcification and changing its location within the fibrous cap area. Results show that 84.0% of calcified cases increase the fatigue life up to 11.4%. For rupture paths 10D far from the calcification, the life change is negligible. Calcifications close to lumen increase more fatigue life than those close to the lipid pool. Also, calcifications in the middle area of fibrous cap increase more fatigue life than those in the shoulder area. Conclusion. Calcifications may play a positive role in the plaque stability. The influence of the calcification only exists in a local area. Calcifications close to lumen may be influenced more than those close to lipid pool. And calcifications in the middle area of fibrous cap are seemly influenced more than those in the shoulder area. PMID:24955401

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

2014-01-01

200

Ultraviolet Phototherapy Management of Moderate-to-Severe Plaque Psoriasis  

PubMed Central

Executive Summary Objective The purpose of this evidence based analysis was to determine the effectiveness and safety of ultraviolet phototherapy for moderate-to-severe plaque psoriasis. Research Questions The specific research questions for the evidence review were as follows: What is the safety of ultraviolet phototherapy for moderate-to-severe plaque psoriasis? What is the effectiveness of ultraviolet phototherapy for moderate-to-severe plaque psoriasis? Clinical Need: Target Population and Condition Psoriasis is a common chronic, systemic inflammatory disease affecting the skin, nails and occasionally the joints and has a lifelong waning and waxing course. It has a worldwide occurrence with a prevalence of at least 2% of the general population, making it one of the most common systemic inflammatory diseases. The immune-mediated disease has several clinical presentations with the most common (85% - 90%) being plaque psoriasis. Characteristic features of psoriasis include scaling, redness, and elevation of the skin. Patients with psoriasis may also present with a range of disabling symptoms such as pruritus (itching), pain, bleeding, or burning associated with plaque lesions and up to 30% are classified as having moderate-to-severe disease. Further, some psoriasis patients can be complex medical cases in which diabetes, inflammatory bowel disease, and hypertension are more likely to be present than in control populations and 10% also suffer from arthritis (psoriatic arthritis). The etiology of psoriasis is unknown but is thought to result from complex interactions between the environment and predisposing genes. Management of psoriasis is related to the extent of the skin involvement, although its presence on the hands, feet, face or genitalia can present challenges. Moderate-to-severe psoriasis is managed by phototherapy and a range of systemic agents including traditional immunosuppressants such as methotrexate and cyclospsorin. Treatment with modern immunosuppressant agents known as biologicals, which more specifically target the immune defects of the disease, is usually reserved for patients with contraindications and those failing or unresponsive to treatments with traditional immunosuppressants or phototherapy. Treatment plans are based on a long-term approach to managing the disease, patient’s expectations, individual responses and risk of complications. The treatment goals are several fold but primarily to: 1) improve physical signs and secondary psychological effects, 2) reduce inflammation and control skin shedding, 3) control physical signs as long as possible, and to 4) avoid factors that can aggravate the condition. Approaches are generally individualized because of the variable presentation, quality of life implications, co-existent medical conditions, and triggering factors (e.g. stress, infections and medications). Individual responses and commitments to therapy also present possible limitations. Phototherapy Ultraviolet phototherapy units have been licensed since February 1993 as a class 2 device in Canada. Units are available as hand held devices, hand and foot devices, full-body panel, and booth styles for institutional and home use. Units are also available with a range of ultraviolet A, broad and narrow band ultraviolet B (BB-UVB and NB-UVB) lamps. After establishing appropriate ultraviolet doses, three-times weekly treatment schedules for 20 to 25 treatments are generally needed to control symptoms. Evidence-Based Analysis Methods The literature search strategy employed keywords and subject headings to capture the concepts of 1) phototherapy and 2) psoriasis. The search involved runs in the following databases: Ovid MEDLINE (1996 to March Week 3 2009), OVID MEDLINE In-Process and Other Non-Indexed Citations, EMBASE (1980 to 2009 Week 13), the Wiley Cochrane Library, and the Centre for Reviews and Dissemination/International Agency for Health Technology Assessment. Parallel search strategies were developed for the remaining databases. Search results were limited to human and English-language

2009-01-01

201

Modified COMS Plaques for {sup 125}I and {sup 103}Pd Iris Melanoma Brachytherapy  

SciTech Connect

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.

Thomson, Rowan M., E-mail: rthomson@physics.carleton.c [Ottawa Carleton Institute of Physics, Carleton University, Ottawa, ON (Canada); Furutani, Keith M.; Pulido, Jose S.; Stafford, Scott L. [Mayo Clinic College of Medicine, Rochester, MN (United States); Rogers, D.W.O. [Ottawa Carleton Institute of Physics, Carleton University, Ottawa, ON (Canada)

2010-11-15

202

Nestin and WT1 expression in atheromathous plaque neovessels: Association with vulnerability.  

PubMed

Introduction. Neoangiogenesis is crucial for the progression and vulnerability of atheromasic lesions. Since adult vasa vasorum, which represent the neoangiogenetic burden of healthy arteries, constitutively express Nestin and Wilms Tumor (WT1), the aims of the present study are: i) to describe and quantify Nestin and WT1 in plaque neovessels; ii) to investigate the relationship between neovessel phenotype and plaque instability. Methods. We prospectively evaluated 49 consecutive carotid endarterectomy specimens. Histopathological characteristics were separately collected, particularly the intraplaque histological complications. Immunohistochemistry was carried out for CD34, Nestin and WT1; the density of positivity was evaluated for each marker. RT-PCR was performed to assess Nestin and WT1 mRNA levels on the first 10 plaques and on 10 control arteries. Results. Six (12.2%) plaques showed no neoangiogenesis. In the others, the mean immunohistochemical densities of CD34, Nestin, and WT1-positive structures were 41.88, 28.84 and 17.68/mm2. Among the CD34+ neovessels, 68% and 42% expressed Nestin and WT1 respectively, i.e., nearly 36% of the neovessels resulted to be Nestin+/WT1-. Furthermore, complicated plaques (n=30) showed significantly more CD34 and Nestin-positive vessels than uncomplicated plaques (n=13; P=0.045 and P=0.009), while WT1 was not increased (P=0.139). RT-PCR confirmed that WT1 gene expression was 3-fold lower than Nestin gene in plaques (p=0.001). Conclusions. Plaque neoangiogenesis shows both a Nestin+/WT1- and a Nestin+/WT1+ phenotype. The Nestin+/WT1- neovessels are significantly more abundant in complicated (vulnerable) plaques. The identification of new transcription factors in plaque neoangiogenesis, and their possible regulation, can open new perspectives in the therapy of vulnerable plaques. PMID:24861148

Fittipaldi, Silvia; Vasuri, Francesco; Degiovanni, Alessio; Pini, Rodolfo; Mauro, Raffaella; Faggioli, Gianluca; D'Errico-Grigioni, Antonia; Stella, Andrea; Pasquinelli, Gianandrea

2014-12-01

203

Association of statin therapy with reduced coronary plaque rupture: an optical coherence tomography study  

PubMed Central

Objective Statin therapy induces plaque regression and may stabilize atheromatous plaques. Optical coherence tomography (OCT) is a high-resolution in-vivo imaging modality that allows characterization of atherosclerotic plaques. We aimed to demonstrate the potential utility of OCT in evaluating coronary plaques in patients with or without statin therapy. Methods Patients undergoing cardiac catheterization were enrolled. We identified culprit lesions and performed intracoronary OCT imaging. Plaque lipid pool, fibrous cap thickness, and frequency of thin-cap fibroatheroma were evaluated using previously validated criteria. Macrophage density was determined from optical signals within fibrous caps. Presence of calcification, thrombosis, and rupture was assessed. Results Forty-eight patients were included (26 on statins, 22 without statins). Baseline characteristics were similar apart from lipid profile. Patients on statin therapy had lower total and low-density lipoprotein cholesterol concentrations (4.45± 1.35 vs. 5.26 ± 0.83 mmol/l, P = 0.02; 2.23 ± 0.78 vs. 3.26 ±0.62 mmol/l, P < 0.001, respectively). Frequencies of lipid-rich plaque (69 vs. 82%), thin-cap fibroatheroma (31 vs. 50%), plaque calcification (15 vs. 5%) and thrombosis (15 vs. 32%), and fibrous cap macrophage density were comparable between statin and nonstatin groups (5.9 vs. 6.3%; all P =NS). Ruptured plaques were, however, significantly less frequent in patients on established statin therapy (8 vs. 36%; P = 0.03) with a trend toward increased minimum fibrous cap thickness (78 vs. 49 ?m; P = 0.07). Conclusion We demonstrated the use of OCT in plaque characterization and found that patients on prior statin therapy have reduced incidence of ruptured plaques and a trend toward thicker fibrous caps. This suggests that statins may stabilize coronary plaques. PMID:18480667

Chia, Stanley; Raffel, Owen Christopher; Takano, Masamichi; Tearney, Guillermo J.; Bouma, Brett E.; Jang, Ik-Kyung

2009-01-01

204

Plaque pH and Associated Parameters in Relation to Caries  

Microsoft Academic Search

Intensified plaque acidogenicity in caries–prone subjects was reported many years ago, but emerging evidence has suggested that the relationship may not be as strong as once thought. We have now determined a range of acidogenicity variables in subjects having both caries prevalence and incidence data, and have included plaque mineral data in the analysis. pH measurements were made in 20

E. I. F. Pearce; L. Yue; M. J. Larsen

1999-01-01

205

Microbial Processes Associated with Roots of Bulbous Rush Coated with Iron Plaques  

Microsoft Academic Search

Bulbous rush ( Juncus bulbosus) is a pioneer species in acidic, iron-rich, coal mining lakes in the eastern part of Germany. Juncus roots are coated with iron plaques, and it has been suggested that microbial processes under the iron plaques might be supportive for Juncus plant growth. The objectives of this work were to enumerate the microbes involved in the

K. Küsel; A. Chabbi; T. Trinkwalter

2003-01-01

206

Subgemmal neurogenous plaque associated with burning tongue: report of two cases and review of the literature  

Microsoft Academic Search

Subgemmal neurogenous plaques, biphasic structures with a neurofibroma and neuroma patterns, are observed in tongue biopsies involving subepithelial areas, being characterized as aggregates of nerve plexus and ganglion cells. Oral burning symptoms, having many possible causes, are commonly observed during oral medicine practice, but the association of subgemmal neurogenous plaque with tongue burning symptoms is very unusual. Reported here are

L. A. Gueiros; J. E. Leon; M. A. Lopes; O. P. de Almeida; J. Jorge

2008-01-01

207

Detection and photodynamic therapy of inflamed atherosclerotic plaques in the carotid artery of rabbits  

E-print Network

Detection and photodynamic therapy of inflamed atherosclerotic plaques in the carotid artery Keywords: Atherosclerosis Vulnerable plaque Macrophage Fluorescence intensity Photodynamic therapy a b s t r a c t Photodynamic therapy (PDT) has been applied in the treatment of artery restenosis following

Cao, Wenwu

208

Measurement of fibrous cap thickness in atherosclerotic plaques by spatiotemporal analysis of laser speckle images  

Microsoft Academic Search

Necrotic-core fibroatheromas (NCFA) with thin, mechanically weak fibrous caps overlying lipid cores comprise the majority of plaques that rupture and cause acute myocardial infarction. Laser speckle imaging (LSI) has been recently demonstrated to enable atherosclerotic plaque characterization with high accuracy. We investigate spatio-temporal analysis of LSI data, in conjunction with diffusion theory and Monte Carlo modeling of light transport, to

Seemantini K. Nadkarni; Alberto Bilenca; Brett E. Bouma; Guillermo J. Tearney

2006-01-01

209

Cell death in human atherosclerotic plaques involves both oncosis and apoptosis  

Microsoft Academic Search

The aim of the present study was to analyze the frequency and mechanism of cell death in atherosclerotic plaques with a recent history (70% diameter reduction undergoing carotid endarterectomy. In situ tailing and nick translation of fragmented DNA, agarose gel electrophoresis of plaque DNA and electron microscopy were used to identify cell death by apoptosis (programmed cell death) and oncosis.

Milita Crisby; Bengt Kallin; Johan Thyberg; Boris Zhivotovsky; Sten Orrenius; Vasilios Kostulas; Jan Nilsson

1997-01-01

210

Characterization of Cholesterol Crystals in Atherosclerotic Plaques Using Stimulated Raman Scattering and Second-Harmonic Generation  

E-print Network

Characterization of Cholesterol Crystals in Atherosclerotic Plaques Using Stimulated Raman ABSTRACT Cholesterol crystals (ChCs) have been identified as a major factor of plaque vulnerability cholesterol in its native tissue environment, the physiochemical role of ChCs in atherosclerotic progression

Chen, Zhongping

211

Correlation of cholinergic abnormalities with senile plaques and mental test scores in senile dementia  

Microsoft Academic Search

Necropsy brain tissue from normal (control) patients and patients with depression and dementia was examined for activities of various cholinergic components, and these related to the degree of senile plaque formation and extent of intellectual impairment. Choline acetyltransferase and acetylcholinesterase activities decreased significantly as the mean plaque count rose, and in depressed and demented subjects the reduction in choline acetyltransferase

E K Perry; B E Tomlinson; G Blessed; K Bergmann; P H Gibson; R H Perry

1978-01-01

212

Effects of dental plaque antiseptic decontamination on bacterial colonization and nosocomial infections in critically ill patients  

Microsoft Academic Search

Objectives: To document in intensive care unit (ICU) patients the effect of dental plaque antiseptic decontamination on the occurrence of plaque colonization by aerobic nosocomial pathogens and nosocomial infections. Design: Single-blind randomized comparative study. Setting: A 16-bed adult intensive care unit in a university hospital. Patients: Patients consecutively admitted in the ICU with a medical condition suggesting an ICU stay

F. Fourrier; E. Cau-Pottier; H. Boutigny; M. Roussel-Delvallez; M. Jourdain; C. Chopin

2000-01-01

213

Online-only Material Genetic susceptibility for Alzheimer's disease neuritic plaque pathology  

E-print Network

................................2 eTable 2: Detailed top results of the neuritic plaque GWAS .............................3 eTable 4: Neuritic GWAS SNPs evaluated for associations with cognitive decline ......... Excel...............................................................................6 eFigure 1: Neuritic plaque GWAS quantile-quantile and Manhattan plots

de Bakker, Paul

214

Laser-induced fluorescence detection of atherosclerotic plaque with hematoporphyrin derivative used as an exogenous probe.  

PubMed

Clinical use of laser angioplasty is limited by the lack of an adequate guidance system. As a first step toward developing a reliable guidance system, laser-induced surface fluorescence and a fluorescent probe were used to differentiate plaque from normal arterial wall. The aortas from four normal New Zealand white rabbits and six atherosclerotic rabbits were studied in vitro. Rabbits from each group received 2.5 mg/kg of hematoporphyrin derivative intravenously 24 hours before death. Segments of the aortas were irradiated with a helium-cadmium laser, and the tissue surface fluorescence spectra were recorded with an optical multichannel analyzer. A plaque index, based on the resulting spectra, was calculated for each specimen of aorta. The spectra from normal aorta without hematoporphyrin derivative, normal aorta with hematoporphyrin derivative, and from plaque of atherosclerotic rabbits without hematoporphyrin derivative showed the same wavelength dependence. The plaque index values were not significantly different from one another. However, in plaque from atherosclerotic rabbits given hematoporphyrin derivative, the spectrum was markedly different, showing a broad spectral peak at 632 nm. This spectral peak corresponds to the spectral peak of hematoporphyrin derivative and was only seen in the plaque of atherosclerotic rabbits given hematoporphyrin derivative. The plaque index for these specimens was significantly different from all other specimens (p less than 0.001). This difference in fluorescence spectra and plaque index could be incorporated into a guidance system for laser angioplasty. PMID:2965255

Prevosti, L G; Wynne, J J; Becker, C G; Linsker, R; Shires, G T

1988-04-01

215

Enamel microhardness and fluoride uptake underneath fermenting and non-fermenting artificial plaque.  

PubMed

Washed cells of Streptococcus sanguis were used to form artificial plaque on the surface of bovine enamel and incubated underneath buffer solutions, initial pH 6, for 36 h at 37 degrees C. The decrease in the microhardness of the enamel surface under fermenting "plaque" could be prevented with fluoride. Enamel under a fermenting "plaque" took up significantly more (P less than 0.0u) fluoride than enamel under a non-fermenting "plaque" (initial F- in buffer: 10 parts/10(6)). The artificial plaque did not accumulate fluoride. Within fermenting "plaques/, the pH decreased significantly more without flouride (P less than 0.01) than with fluoride. Fluoride combined with sucrose more than negated the softening of the enamel caused by sucrose fermentation, i.e. it increased the hardness above the original values. The diffusion of fluoride through the fermenting artificial plaque was more rapid than through a non-fermenting plaque. These findings suggest that caries-conducive circumstances may promote fluoride uptake by enamel compared with non-caries-conducive circumstances. PMID:22924

Turtola, L O

1977-09-01

216

Ferritin is a component of the neuritic (senile) plaque in Alzheimer dementia  

Microsoft Academic Search

A strong immunoreactivity for ferritin was observed in the neuritic (senile) plaques in Alzheimer's disease hippocampus. The ferritin accumulation was almost exclusively associated with the microglia, which appeared to have proliferated greatly. These cells were also positive for HLA-DR, a putative marker for reactive microglia. In contrast, in the diffuse plaques, which were without neuritic pathology, the ferritin-stained microglia appeared

I. Grundke-Iqbal; J. Fleming; Y.-C. Tung; H. Lassmann; K. Iqbal; J. G. Joshi

1990-01-01

217

Chlamydia pneumoniae DNA in non-coronary atherosclerotic plaques and circulating leukocytes  

Microsoft Academic Search

Earlier studies have associated atherosclerosis with Chlamydia pneumoniae infection. C. pneumoniae may circulate via monocytes and migrate into plaques by leukocyte infiltration; however, detection is difficult. We developed a novel polymerase chain reaction (PCR) method to test the hypothesis that C. pneumoniae DNA in circulating leukocytes is correlated with C. pneumoniae DNA in plaque material and that C. pneumoniae copy

Mario Berger; Babette Schröder; Georg Daeschlein; Wolfgang Schneider; Andreas Busjahn; Igor Buchwalow; Friedrich C. Luft; Hermann Haller

2000-01-01

218

Quantification of coronary hemodynamics and plaque morphology using xray angiography and  

E-print Network

Quantification of coronary hemodynamics and plaque morphology using x­ray angiography arteries by fusion of data from x­ray angiography and intravascular ultrasound (IVUS) and elaborates angiography, intravascular ultrasound 1. Introduction Understanding the mechanisms of plaque development

Wahle, Andreas

219

Presence of Chlamydia pneumoniae in Human Symptomatic and Asymptomatic Carotid Atherosclerotic Plaque  

Microsoft Academic Search

Background— Chlamydia pneumoniaehas been identified in atherosclerotic plaques of patients with cerebrovascular and cardiovascular disease. However, the direct causative effect of C pneumoniae infection in the activation of atherosclerotic plaque to a prothrombotic state remains to be established. The aim of the present study is to examine the correlation between intraplaque presence of chlamydiae and symptomatic carotid disease in humans.

Ronald LaBiche; Deloris Koziol; Thomas C. Quinn; Charlotte Gaydos; Salman Azhar; Gary Ketron; Suman Sood; Thomas J. DeGraba

2010-01-01

220

Effects of a lactoperoxidase-system-containing toothpaste on dental plaque and whole saliva in vivo.  

PubMed

The effects of a lactoperoxidase-system-containing toothpaste. Biotene, on saliva and dental plaque were studied. In a double-blind crossover study 20 healthy volunteers used an experimental (comprising the complete peroxidase system) or a placebo (without lactoperoxidase, KSCN, and glucose oxidase) toothpaste twice daily for 2 weeks separated by a 2-week washout period. At base lines and at the end of both test periods saliva and plaque samples were collected, and plaque pH changes were monitored. Saliva was analyzed for hypothiocyanite (HOSCN/OSCN-) and thiocyanate (SCN-) concentrations and salivary peroxidase activity. The amount of total streptococci, mutans streptococci, lactobacilli, and total anaerobic flora was determined both in saliva and in plaque samples. The accumulation and the acidogenicity of plaque were also quantitated. A 2-week daily use of Biotene had no effect on salivary flow rate, peroxidase activity, HOSCN/OSCN-, SCN-, or any of the monitored bacterial counts compared with the placebo toothpaste. The accumulation of dental plaque was not affected by the lactoperoxidase-system-containing toothpaste. The acidogenicity of plaque did not change significantly, nor did the two test dentifrices differ in their ability to inhibit the plaque pH drop caused by sucrose in subjects with normal salivary flow rate. PMID:7887144

Kirstilä, V; Lenander-Lumikari, M; Tenovuo, J

1994-12-01

221

The efficacy of a herbal-based toothpaste on the control of plaque and gingivitis.  

PubMed

A double-blind controlled clinical trial with parallel groups was designed to investigate the effectiveness of a herbal-based toothpaste in the control of plaque and gingivitis as compared with a conventional dentifrice. 70 subjects with gingivitis completed the 6-week study. All participants had at least 20 natural teeth with no probing depths greater than 3 mm and a plaque index of 2 or more at baseline. At baseline, both groups were balanced for the parameters measured: plaque index, plaque vitality, gingival index, bleeding on probing and gingival crevicular fluid flow. At the end of the trial, there were reductions within both groups, however, there were no significant differences between the groups. It was concluded that the herbal based toothpaste was as effective as the conventionally formulated dentifrice in the control of plaque and gingivitis. PMID:7593698

Mullally, B H; James, J A; Coulter, W A; Linden, G J

1995-09-01

222

Roentgenographic evidence for predominant left-sided location of unilateral pleural plaques.  

PubMed

The roentgenographic prevalence and anatomic distribution of pleural plaques were studied in the US Navy Asbestos Medical Surveillance Program population (105,064 individuals as of July 17, 1985). "Definite" or "probable" pleural plaques were noted in 4.4 percent of films. These were unilateral in 19.3 percent of roentgenograms with "definite" pleural plaque and 33.9 percent of films with "probable" pleural plaque. Unilateral findings were more often left-sided than right-sided; a ratio of 287:82 in the "definite" group and 625:287 in the "probable" group. Left-sided predominance of unilateral plaque is a consistent and unexplained epidemiologic finding that may provide clues to pleural pathogenesis following asbestos exposure. PMID:2721262

Withers, B F; Ducatman, A M; Yang, W N

1989-06-01

223

A Voxel-Map Quantitative Analysis Approach for Atherosclerotic Noncalcified Plaques of the Coronary Artery Tree  

PubMed Central

Noncalcified plaques (NCPs) are associated with the presence of lipid-core plaques that are prone to rupture. Thus, it is important to detect and monitor the development of NCPs. Contrast-enhanced coronary Computed Tomography Angiography (CTA) is a potential imaging technique to identify atherosclerotic plaques in the whole coronary tree, but it fails to provide information about vessel walls. In order to overcome the limitations of coronary CTA and provide more meaningful quantitative information for percutaneous coronary intervention (PCI), we proposed a Voxel-Map based on mathematical morphology to quantitatively analyze the noncalcified plaques on a three-dimensional coronary artery wall model (3D-CAWM). This approach is a combination of Voxel-Map analysis techniques, plaque locating, and anatomical location related labeling, which show more detailed and comprehensive coronary tree wall visualization. PMID:24348749

Li, Ying; Chen, Wei; Chen, Yonglin; Chu, Chun; Fang, Bingji; Tan, Liwen

2013-01-01

224

Age differentiation of rat smooth muscle cells : altered proliferation profile, cellular changes, and implications for atherosclerotic plaque destabilization  

E-print Network

Clinical evidence has shown that the elderly are at a higher risk for atherosclerotic plaque destabilization. The effect of aging on smooth muscle cells, a major cell type in the plaque, is central to the process of disease ...

Huang, Chen-Wen, 1979-

2004-01-01

225

Vitamin K-Antagonists Accelerate Atherosclerotic Calcification and Induce a Vulnerable Plaque Phenotype  

PubMed Central

Background Vitamin K-antagonists (VKA) are treatment of choice and standard care for patients with venous thrombosis and thromboembolic risk. In experimental animal models as well as humans, VKA have been shown to promote medial elastocalcinosis. As vascular calcification is considered an independent risk factor for plaque instability, we here investigated the effect of VKA on coronary calcification in patients and on calcification of atherosclerotic plaques in the ApoE?/? model of atherosclerosis. Methodology/Principal Findings A total of 266 patients (133 VKA users and 133 gender and Framingham Risk Score matched non-VKA users) underwent 64-slice MDCT to assess the degree of coronary artery disease (CAD). VKA-users developed significantly more calcified coronary plaques as compared to non-VKA users. ApoE?/? mice (10 weeks) received a Western type diet (WTD) for 12 weeks, after which mice were fed a WTD supplemented with vitamin K1 (VK1, 1.5 mg/g) or vitamin K1 and warfarin (VK1&W; 1.5 mg/g & 3.0 mg/g) for 1 or 4 weeks, after which mice were sacrificed. Warfarin significantly increased frequency and extent of vascular calcification. Also, plaque calcification comprised microcalcification of the intimal layer. Furthermore, warfarin treatment decreased plaque expression of calcification regulatory protein carboxylated matrix Gla-protein, increased apoptosis and, surprisingly outward plaque remodeling, without affecting overall plaque burden. Conclusions/Significance VKA use is associated with coronary artery plaque calcification in patients with suspected CAD and causes changes in plaque morphology with features of plaque vulnerability in ApoE?/? mice. Our findings underscore the need for alternative anticoagulants that do not interfere with the vitamin K cycle. PMID:22952653

Schurgers, Leon J.; Chatrou, Martijn L. L.; Herfs, Marjolein; Winkens, Mark H. M.; Westenfeld, Ralf; Veulemans, Verena; Krueger, Thilo; Shanahan, Catherine M.; Jahnen-Dechent, Willi; Biessen, Erik; Narula, Jagat; Vermeer, Cees; Hofstra, Leonard; Reutelingsperger, Chris P.

2012-01-01

226

Automated Detection Framework of the Calcified Plaque with Acoustic Shadowing in IVUS Images  

PubMed Central

Intravascular Ultrasound (IVUS) is one ultrasonic imaging technology to acquire vascular cross-sectional images for the visualization of the inner vessel structure. This technique has been widely used for the diagnosis and treatment of coronary artery diseases. The detection of the calcified plaque with acoustic shadowing in IVUS images plays a vital role in the quantitative analysis of atheromatous plaques. The conventional method of the calcium detection is manual drawing by the doctors. However, it is very time-consuming, and with high inter-observer and intra-observer variability between different doctors. Therefore, the computer-aided detection of the calcified plaque is highly desired. In this paper, an automated method is proposed to detect the calcified plaque with acoustic shadowing in IVUS images by the Rayleigh mixture model, the Markov random field, the graph searching method and the prior knowledge about the calcified plaque. The performance of our method was evaluated over 996 in-vivo IVUS images acquired from eight patients, and the detected calcified plaques are compared with manually detected calcified plaques by one cardiology doctor. The experimental results are quantitatively analyzed separately by three evaluation methods, the test of the sensitivity and specificity, the linear regression and the Bland-Altman analysis. The first method is used to evaluate the ability to distinguish between IVUS images with and without the calcified plaque, and the latter two methods can respectively measure the correlation and the agreement between our results and manual drawing results for locating the calcified plaque in the IVUS image. High sensitivity (94.68%) and specificity (95.82%), good correlation and agreement (>96.82% results fall within the 95% confidence interval in the Student t-test) demonstrate the effectiveness of the proposed method in the detection of the calcified plaque with acoustic shadowing in IVUS images. PMID:25372784

Liu, Xin; Huang, Wenhua; Zhang, Heye; Tan, Ning; Hau, William Kongto; Zhang, Yuan-Ting; Liu, Huafeng

2014-01-01

227

Automated Detection Framework of the Calcified Plaque with Acoustic Shadowing in IVUS Images.  

PubMed

Intravascular Ultrasound (IVUS) is one ultrasonic imaging technology to acquire vascular cross-sectional images for the visualization of the inner vessel structure. This technique has been widely used for the diagnosis and treatment of coronary artery diseases. The detection of the calcified plaque with acoustic shadowing in IVUS images plays a vital role in the quantitative analysis of atheromatous plaques. The conventional method of the calcium detection is manual drawing by the doctors. However, it is very time-consuming, and with high inter-observer and intra-observer variability between different doctors. Therefore, the computer-aided detection of the calcified plaque is highly desired. In this paper, an automated method is proposed to detect the calcified plaque with acoustic shadowing in IVUS images by the Rayleigh mixture model, the Markov random field, the graph searching method and the prior knowledge about the calcified plaque. The performance of our method was evaluated over 996 in-vivo IVUS images acquired from eight patients, and the detected calcified plaques are compared with manually detected calcified plaques by one cardiology doctor. The experimental results are quantitatively analyzed separately by three evaluation methods, the test of the sensitivity and specificity, the linear regression and the Bland-Altman analysis. The first method is used to evaluate the ability to distinguish between IVUS images with and without the calcified plaque, and the latter two methods can respectively measure the correlation and the agreement between our results and manual drawing results for locating the calcified plaque in the IVUS image. High sensitivity (94.68%) and specificity (95.82%), good correlation and agreement (>96.82% results fall within the 95% confidence interval in the Student t-test) demonstrate the effectiveness of the proposed method in the detection of the calcified plaque with acoustic shadowing in IVUS images. PMID:25372784

Gao, Zhifan; Guo, Wei; Liu, Xin; Huang, Wenhua; Zhang, Heye; Tan, Ning; Hau, William Kongto; Zhang, Yuan-Ting; Liu, Huafeng

2014-01-01

228

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

NASA Astrophysics Data System (ADS)

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.

Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

2014-07-01

229

Calcium Oxalate Stones Are Frequently Found Attached to Randall's Plaque  

SciTech Connect

The exact mechanisms of the crystallization processes that occur during the formation of calcium oxalate calculi are controversial. Over six decades ago, Alexander Randall reported on a series of cadaveric renal units in which he observed calcium salt deposits on the tips of the renal papilla. Randall hypothesized that these deposits, eponymously termed Randall's plaque, would be the ideal site for stone formation, and indeed in a number of specimens he noted small stones attached to the papillae. With the recent advent of digital endoscopic imaging and micro computerized tomography (CT) technology, it is now possible to inspect the renal papilla of living, human stone formers and to study the attached stone with greater scrutiny.

Matlaga, Brian R. [James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, 4940 Eastern Ave / Room A 345, Baltimore, Maryland 21224 (United States); Williams, James C. Jr.; Evan, Andrew P. [Departments of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Dr /MS 5035, Indianapolis, Indiana, 46202 (United States); Lingeman, James E. [Methodist Hospital Institute for Kidney Stone Disease, 1801 N. Senate Blvd, Suite 220, Indianapolis, Indiana, 46202 (United States)

2007-04-05

230

Models of neurodegenerative disease - Alzheimer's Anatomical and amyloid plaque imaging  

PubMed Central

Alzheimer's disease (AD) is an important social and economic issue for our societies. The development of therapeutics against this severe dementia requires assessing the effects of new drugs in animal models thanks to dedicated biomarkers. According to the amyloid cascade hypothesis, ?–amyloid deposits are at the origin of most of the lesions associated with AD. These extracellular deposits are therefore one of the main targets in therapeutical strategies. A? peptides can be revealed histologically with specific dyes or antibodies, or by magnetic resonance microscopy (µMRI) that uses their association with iron as a source of signal. The microscopic size of the lesions necessitates the development of specific imaging protocols. Most protocols use T2-weighted sequences that reveal the aggregates as hypointense spots. This chapter describes histological methods that reveal amyloid plaques with specific stains and MR imaging protocols for in vivo and ex vivo MR imaging of AD mice. PMID:21874485

Petiet, Alexandra; Delatour, Benoit; Dhenain, Marc

2013-01-01

231

Review of diagnostic plaque reduction neutralization tests for flavivirus infection.  

PubMed

Flavivirus infections (including Japanese encephalitis, West Nile encephalitis and dengue fever/severe dengue) present a worldwide public health problem. Recent climate change may affect the geographical distribution of the arthropod vectors for these viruses and so the risk of flavivirus epidemics may increase. Many methods have been developed for the serological diagnosis of flavivirus infections, such as haemagglutination inhibition assay, enzyme-linked immunosorbent assay, and immunofluorescence in staining. However, the specificity of these assays varies. The plaque reduction neutralizing test (PRNT) using live viruses is currently the 'gold standard' for the differential serodiagnosis of flaviviruses. The specificity of results obtained with PRNT is better than that for other protocols and many laboratories apply the PRNT protocol to the differential serodiagnosis of flaviviruses. Here, recent refinements to the PRNT protocols with genetically modified recombinant viruses or reporter-harbouring virus-like particles are reviewed. Further, the problems associated with the differential serodiagnosis of flaviviruses using PRNT are discussed. PMID:23036176

Maeda, Akihiko; Maeda, Junko

2013-01-01

232

Calcium Oxalate Stones Are Frequently Found Attached to Randall's Plaque  

NASA Astrophysics Data System (ADS)

The exact mechanisms of the crystallization processes that occur during the formation of calcium oxalate calculi are controversial. Over six decades ago, Alexander Randall reported on a series of cadaveric renal units in which he observed calcium salt deposits on the tips of the renal papilla. Randall hypothesized that these deposits, eponymously termed Randall's plaque, would be the ideal site for stone formation, and indeed in a number of specimens he noted small stones attached to the papillae. With the recent advent of digital endoscopic imaging and micro computerized tomography (CT) technology, it is now possible to inspect the renal papilla of living, human stone formers and to study the attached stone with greater scrutiny.

Matlaga, Brian R.; Williams, James C.; Evan, Andrew P.; Lingeman, James E.

2007-04-01

233

The Level of Mercury in Human Dental Plaque and Interaction in vitro between Biofilms of Streptococcus mutans and Dental Amalgam  

Microsoft Academic Search

Mercury levels (ug\\/mg dry weight) in dental plaque from amalgam and enamel surfaces in human subjects with amalgam restorations were (range, mean, SD) 0.5-1.31, 0.72,0.34 and 0.01-0.54, 0.2, 0.19, respectively. The levels of mercury in plaque from amalgam surfaces were significantly higher than those from plaque on enamel (p < 0.001). No mercury was detected in plaque from subjects without

H. A. Lyttle; G. H. Bowden

1993-01-01

234

Identification of Atherosclerotic Plaques in Carotid Artery by Fluorescence Spectroscopy  

NASA Astrophysics Data System (ADS)

The aim of this work was to identify the presence of atherosclerotic plaques in carotid artery using the Fluorescence Spectroscopy. The most important pathogeny in the cardiovascular disorders is the atherosclerosis, which may affect even younger individuals. With approximately 1.2 million heart attacks and 750,000 strokes afflicting an aging American population each year, cardiovascular disease remains the number one cause of death. Carotid artery samples were obtained from the Autopsy Service at the University of São Paulo (São Paulo, SP, Brazil) taken from cadavers. After a histopathological analysis the 60 carotid artery samples were divided into two groups: normal (26) and atherosclerotic plaques (34). Samples were irradiated with the wavelength of 488 nm from an Argon laser. A 600 ?m core optical fiber, coupled to the Argon laser, was used for excitation of the sample, whereas another 600 optical fiber, coupled to the spectrograph entrance slit, was used for collecting the fluorescence from the sample. Measurements were taken at different points on each sample and then averaged. Fluorescence spectra showed a single broad line centered at 549 nm. The fluorescence intensity for each sample was calculated by subtracting the intensity at the peak (550 nm) and at the bottom (510 nm) and then data were statistically analyzed, looking for differences between both groups of samples. ANOVA statistical test showed a significant difference (p<0,05) between both types of tissues, with regard to the fluorescence peak intensities. Our results indicate that this technique could be used to detect the presence of the atherosclerotic in carotid tissue.

Rocha, Rick; Villaverde, Antonio Balbin; Silveira, Landulfo; Costa, Maricília Silva; Alves, Leandro Procópio; Pasqualucci, Carlos Augusto; Brugnera, Aldo

2008-04-01

235

Antibody-Labeled Liposomes for CT Imaging of Atherosclerotic Plaques  

PubMed Central

We evaluated the specific binding of anti-intercellular adhesion molecule 1 (ICAM-1) conjugated liposomes (immunoliposomes, or ILs) to activated human coronary artery endothelial cells (HCAEC) with the purpose of designing a computed tomographic imaging agent for early detection of atherosclerotic plaques. Covalent attachment of anti-ICAM-1 monoclonal antibodies to pre-formed liposomes stabilized with polyethylene glycol yielded ILs, with a coupling efficiency of the ICAM-1 to the liposomes of 10% to 24%. The anti-ICAM-1–labeled ILs had an average diameter of 136 nm as determined by dynamic light-scattering and cryogenic electron microscopy. The ILs' encapsulation of 5-[N-acetyl-(2,3-dihydroxypropyl)-amino)-N, N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-benzene-1,3-dicarboxamide (iohexol) was determined to be 18% to 19% by a dialysis technique coupled with ultraviolet detection of free iohexol. This encapsulation corresponded to 30 to 38 mg iodine per mL IL solution, and the ILs exhibited 91% to 98.5% iohexol retention at room temperature and under physiologic conditions. The specific binding of the ILs to cultured, activated HCAEC was measured using flow cytometry, enzyme-linked immunosorbent assays, and fluorescence microscopy. The immunosorbent assays demonstrated the specificity of binding of anti-ICAM-1 to ICAM-1 compared with control studies using nonspecific immunoglobulin G-labeled ILs. Flow cytometry and fluorescence microscopy experiments demonstrated the expression of ICAM-1 on the surface of activated HCAEC. Therefore, our iohexol-filled ILs demonstrated potential for implementation in computed tomographic angiography to noninvasively detect atherosclerotic plaques that are prone to rupture. PMID:19876414

Danila, Delia; Partha, Ranga; Elrod, Don B.; Lackey, Melinda; Casscells, S. Ward; Conyers, Jodie L.

2009-01-01

236

Carotid barochemoreceptor pathological findings regarding carotid plaque status and aging  

PubMed Central

BACKGROUND: Carotid barochemoreceptor pathological lesions have been studied in animals, but few human necropsies have been performed. Therefore, data rely on case patients following surgery, radiotherapy and carotid endarterectomy. Almost no data are available regarding whether the effect of aging prevails over pathological conditions, despite the classic description that glomic fibrosis increases with age. OBJECTIVE: To morphometrically characterize the alterations of the carotid barochemoreceptors and their supplying arteries. METHODS: Patients (n=23) who had suffered and died from stroke, with and without complicated internal carotid atheromatosis, were divided by age (group 1: older than 80 years; group 2: 65 to 80 years; and group 3: younger than 65 years). Carotid segments were obtained at autopsy. The specimens were stained for light microscopy and immunohistochemistry. RESULTS: Carotid glomus presented from moderate-to-severe atrophy and fibrosis. A focal decrease in vascularization (CD34-positive) of the glomus (greater than 50%) was observed in areas of atrophy and fibrosis. Damaged nerve endings (S100 protein-positive) were observed at the media of the carotid sinus. Morphometric data showed no differences between groups for glomus area, number of type 1 and 2 cells, and the wall to lumen arteriole ratio. No statistical differences were demonstrated in the pathological findings of the carotid glomus when comparing complicated with noncomplicated plaques or age groups. CONCLUSION: Severe carotid chemoreceptor damage exists in patients who have died from stroke and suffered from carotid atheromatosis. These findings were independent from aging and plaque type. However, damage was correlated with a marked narrowing of the supplying arterioles as a consequence of hemodynamic and/or metabolic alterations (dyslipidemia, diabetes). PMID:19148350

Milei, Jose; Lavezzi, Anna M; Bruni, Barbara; Grana, Daniel R; Azzato, Francisco; Matturri, Luigi

2009-01-01

237

Characterization of Recombinant, Ureolytic Streptococcus mutans Demonstrates an Inverse Relationship between Dental Plaque Ureolytic Capacity and Cariogenicity  

Microsoft Academic Search

Dental caries results from prolonged plaque acidification that leads to the establishment of a cariogenic microflora and demineralization of the tooth. Urease enzymes of oral bacteria hydrolyze urea to ammonia, which can neutralize plaque acids. To begin to examine the relationship between plaque ureolytic activity and the incidence of dental caries, recombinant, ureolytic strains of Streptococcus mutans were constructed. Spe-

K. ANNE CLANCY; SYLVIA PEARSON; WILLIAM H. BOWEN; ROBERT A. BURNE

2000-01-01

238

Quantitative Evaluation of Carotid Plaque Echogenicity by Integrated Backscatter Analysis: Correlation with Symptomatic History and Histologic Findings  

Microsoft Academic Search

Background and Purpose: Echogenicity of carotid plaque well reflects the risk of ischemic stroke and may be predictive of the histologic content of the plaque. However, objective evaluation of plaque echogenicity has been hampered by a lack of established quantitative measures. This study examined the relation between echogenicity assessed by integrated backscatter (IBS) analysis and (1) symptomatic history and (2)

Keiko Nagano; Hiroshi Yamagami; Yoshitane Tsukamoto; Kazuyuki Nagatsuka; Masahiro Yasaka; Izumi Nagata; Masatsugu Hori; Kazuo Kitagawa; Hiroaki Naritomi

2008-01-01

239

Plaque Removal and Thrombus Dissolution with the Photoacoustic Energy of Pulsed-Wave Lasers – Biotissue Interactions and Their Clinical Manifestations  

Microsoft Academic Search

Pulsed-wave lasers ablate atherosclerotic plaque and dissolve coronary thrombus by emission of photoacoustic energy initiating photomechanical, photochemical and photothermal transformation. The newly discovered process of ‘inertially confined ablation’ ascribes to pressure generation and plaque vaporization during lasing. Tremendous pressure within the lased plaque and gas bubble formation account for adverse clinical manifestations such as perforations, acute vessel closure and dissections.

On Topaz

1996-01-01

240

IGF-1 Has Plaque-Stabilizing Effects in Atherosclerosis by Altering Vascular Smooth Muscle Cell Phenotype  

PubMed Central

Insulin-like growth factor-1 (IGF-1) signaling is important for the maintenance of plaque stability in atherosclerosis due to its effects on vascular smooth muscle cell (vSMC) phenotype. To investigate this hypothesis, we studied the effects of the highly inflammatory milieu of the atherosclerotic plaque on IGF-1 signaling and stability-related phenotypic parameters of murine vSMCs in vitro, and the effects of IGF-1 supplementation on plaque phenotype in an atherosclerotic mouse model. M1-polarized, macrophage-conditioned medium inhibited IGF-1 signaling by ablating IGF-1 and increasing IGF-binding protein 3, increased vSMC apoptosis, and decreased proliferation. Expression of ?-actin and col3a1 genes was strongly attenuated by macrophage-conditioned medium, whereas expression of matrix-degrading enzymes was increased. Importantly, all of these effects could be corrected by supplementation with IGF-1. In vivo, treatment with the stable IGF-1 analog Long R3 IGF-1 in apolipoprotein E knockout mice reduced stenosis and core size, and doubled cap/core ratio in early atherosclerosis. In advanced plaques, Long R3 IGF-1 increased the vSMC content of the plaque by more than twofold and significantly reduced the rate of intraplaque hemorrhage. We believe that IGF-1 in atherosclerotic plaques may have a role in preventing plaque instability, not only by modulating smooth muscle cell turnover, but also by altering smooth muscle cell phenotype. PMID:21281823

von der Thusen, Jan H.; Borensztajn, Keren S.; Moimas, Silvia; van Heiningen, Sandra; Teeling, Peter; van Berkel, Theo J.C.; Biessen, Erik A.L.

2011-01-01

241

Ni-Co alloy plaque for cathode of Ni-Cd battery  

NASA Astrophysics Data System (ADS)

The present invention relates generally to Ni-Cd batteries, and, in particular, relates to the plaque material attached to the cathode. Because of the wide use of nickel-cadmium batteries, the corrosion rates of nickel and nickel-cobalt alloys are of interest to nickel-cadmium battery electrochemical theory and its technology. The plaque material of the cathode consists of a Ni-Co alloy in solid solution wherein the cobalt is by weight percent one to ten percent of the alloy. Conventional methods of applying the plaque material to the nickel core may be used. It is therefore an object of the present invention to provide an improved cathode for a nickel-cadmium battery wherein the nickel corrosion is substantially lessened in the plaque material. One process of making the plaque uses a nickel powder slurry that is applied to a nickel-plated steel core. This is then sintered at a high temperature which results in a very porous structure and an welding of the nickel grains to the core. This plaque is then soaked in appropriate salts to make either a positive or a negative plate; nickel salts make a positive plate and a cadmium salts a negative plate, for example. After impregnation, the plaque is placed in an electrolyte and an electric current is passed therethrough to convert the salts to their final form. In the nickel-cadmium cell, nickel hydroxide is the active material in the positive plate.

Lander, J. J.

1986-03-01

242

Aluminium and Phosphate Uptake by Phragmites australis: the Role of Fe, Mn and Al Root Plaques  

PubMed Central

Aluminium, a potentially phytotoxic metal, is an important constituent of many mine water discharges but has largely been neglected in the literature. The behaviour of this element in the rhizosphere of the wetland plant Phragmites australis was investigated in the laboratory in the presence and absence of Mn and Fe root plaques. Electron microscopy and chemical extraction techniques were utilized to determine the physico?chemical properties of the plaques and any association of Al. Both Mn and Fe plaques occurred as amorphous coatings on root surfaces with uneven distributions. Al was not adsorbed onto the surface of either plaque type but formed a separate phosphate deposit closely resembling the Fe and Mn plaques. Phosphorus was also found to be adsorbed to the surface of the Fe plaques (but not the Mn plaques). Both mechanisms were found to immobilize P at the root surface but this did not significantly reduce the concentration of P in aerial plant tissues that was sufficient to ensure adequate growth. PMID:12096805

BATTY, LESLEY C.; BAKER, ALAN J. M.; WHEELER, BRYAN D.

2002-01-01

243

Quantitative evaluation of atherosclerotic plaque phantom by near-infrared multispectral imaging with three wavelengths  

NASA Astrophysics Data System (ADS)

Atherosclerosis is a primary cause of critical ischemic disease. The risk of critical event is involved the content of lipid in unstable plaque. Near-infrared (NIR) range is effective for diagnosis of atherosclerotic plaque because of the absorption peaks of lipid. NIR multispectral imaging (NIR-MSI) is suitable for the evaluation of plaque because it can provide spectroscopic information and spatial image quickly with a simple measurement system. The purpose of this study is to evaluate the lipid concentrations in plaque phantoms quantitatively with a NIR-MSI system. A NIR-MSI system was constructed with a supercontinuum light, a grating spectrometer and a MCT camera. Plaque phantoms with different concentrations of lipid were prepared by mixing bovine fat and a biological soft tissue model to mimic the different stages of unstable plaque. We evaluated the phantoms by the NIR-MSI system with three wavelengths in the band at 1200 nm. Multispectral images were processed by spectral angle mapper method. As a result, the lipid areas of phantoms were effectively highlighted by using three wavelengths. In addition, the concentrations of lipid areas were classified according to the similarity between measured spectra and a reference spectrum. These results suggested the possibility of image enhancement and quantitative evaluation of lipid in unstable plaque with a NIR-MSI.

Nagao, Ryo; Ishii, Katsunori; Awazu, Kunio

2014-03-01

244

Non-calcified coronary atherosclerotic plaque characterization by dual energy computed tomography.  

PubMed

Coronary heart disease (CHD) is the most prevalent cause of death worldwide. Atherosclerosis which is the condition of plaque buildup on the inside of the coronary artery wall is the main cause of CHD. Rupture of unstable atherosclerotic coronary plaque is known to be the cause of acute coronary syndrome. Vulnerability of atherosclerotic plaque has been related to a large lipid core covered by a fibrous cap. Non-invasive assessment of plaque characterization is necessary due to prognostic importance of early stage identification. The purpose of this study is to use the additional attenuation data provided by dual energy computed tomography (DECT) for plaque characterization. We propose to train supervised learners on pixel values recorded from DECT monochromatic X-ray and material basis pairs images, for more precise classification of fibrous and lipid plaques. The interaction of the pixel values from different image types is taken into consideration, as single pixel value might not be informative enough to separate fibrous from lipid. Organic phantom plaques scanned in a fabricated beating heart phantom were used as ground truth to train the learners. Our results show that support vector machines, artificial neural networks and random forests provide accurate results both on phantom and patient data. PMID:24808227

Yamak, Didem; Panse, Prasad; Pavlicek, William; Boltz, Thomas; Akay, Metin

2014-05-01

245

Viral concentration determination through plaque assays: using traditional and novel overlay systems.  

PubMed

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

Baer, Alan; Kehn-Hall, Kylene

2014-01-01

246

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

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

247

Semi-automated segmentation of carotid artery total plaque volume from three dimensional ultrasound carotid imaging  

NASA Astrophysics Data System (ADS)

Carotid artery total plaque volume (TPV) is a three-dimensional (3D) ultrasound (US) imaging measurement of carotid atherosclerosis, providing a direct non-invasive and regional estimation of atherosclerotic plaque volume - the direct determinant of carotid stenosis and ischemic stroke. While 3DUS measurements of TPV provide the potential to monitor plaque in individual patients and in populations enrolled in clinical trials, until now, such measurements have been performed manually which is laborious, time-consuming and prone to intra-observer and inter-observer variability. To address this critical translational limitation, here we describe the development and application of a semi-automated 3DUS plaque volume measurement. This semi-automated TPV measurement incorporates three user-selected boundaries in two views of the 3DUS volume to generate a geometric approximation of TPV for each plaque measured. We compared semi-automated repeated measurements to manual segmentation of 22 individual plaques ranging in volume from 2mm3 to 151mm3. Mean plaque volume was 43+/-40mm3 for semi-automated and 48+/-46mm3 for manual measurements and these were not significantly different (p=0.60). Mean coefficient of variation (CV) was 12.0+/-5.1% for the semi-automated measurements.

Buchanan, D.; Gyacskov, I.; Ukwatta, E.; Lindenmaier, T.; Fenster, A.; Parraga, G.

2012-03-01

248

Macrophage expression of active MMP-9 induces acute plaque disruption in apoE-deficient mice  

PubMed Central

The majority of acute clinical manifestations of atherosclerosis are due to the physical rupture of advanced atherosclerotic plaques. It has been hypothesized that macrophages play a key role in inducing plaque rupture by secreting proteases that destroy the extracellular matrix that provides physical strength to the fibrous cap. Despite reports detailing the expression of multiple proteases by macrophages in rupture-prone regions, there is no direct proof that macrophage-mediated matrix degradation can induce plaque rupture. We aimed to test this hypothesis by retrovirally overexpressing the candidate enzyme MMP-9 in macrophages of advanced atherosclerotic lesions of apoE–/– mice. Despite a greater than 10-fold increase in the expression of MMP-9 by macrophages, there was only a minor increase in the incidence of plaque fissuring. Subsequent analysis revealed that macrophages secrete MMP-9 predominantly as a proform, and this form is unable to degrade the matrix component elastin. Expression of an autoactivating form of MMP-9 in macrophages in vitro greatly enhances elastin degradation and induces significant plaque disruption when overexpressed by macrophages in advanced atherosclerotic lesions of apoE–/– mice in vivo. These data show that enhanced macrophage proteolytic activity can induce acute plaque disruption and highlight MMP-9 as a potential therapeutic target for stabilizing rupture-prone plaques. PMID:16374516

Gough, Peter J.; Gomez, Ivan G.; Wille, Paul T.; Raines, Elaine W.

2006-01-01

249

Characteristics of Anabaena variabilis influencing plaque formation by cyanophage N-1.  

PubMed

Phage N-1 grown in Anabaena strain 7120 [N-1 . 7120] forms plaques on A. variabilis about 10(-7) to 10(-6) as efficiently as on Anabaena 7120. By manipulating different characteristics of the interaction between phage and host, it was possible to increase the relative efficiency of plaque formation to 0.38. Growth of A. variabilis at 40 degrees C for at least three generations resulted in an increase in the rate of phage adsorption and a 10-fold increase in the efficiency of plaque formation. The efficiency of plaque formation was further increased about 42-fold, with little or no further increase in rate of adsorption, in a variant strain. A. variabilis strain FD, isolated from a culture of A. variabilis which had grown for more than 30 generations at 40 degrees C. The low relative efficiency of plaque formation by N-1 . 7120 on A. variabilis could be partially accounted for if A. variabilis contains a deoxyribonucleic acid restriction endonuclease which is absent from Anabaena 7120. Indirect evidence for such an endonuclease included the following: (i) phage N-1 grown in A. variabilis (N-1 . Av) had approximately a 7 X 10(3)-fold higher relative efficiency of plaque formation on A. variabilis than had N-1 . 7120; and (ii) the efficiency of plaque formation by N-1 . 7120 on A. variabilis strain FD was increased by up to 146-fold after heating the latter organism at 51 degrees C. PMID:110787

Currier, T C; Wolk, C P

1979-07-01

250

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

PubMed Central

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

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

2013-01-01

251

Computer simulation of three-dimensional plaque formation and progression in the carotid artery.  

PubMed

Atherosclerosis is becoming the number one cause of death worldwide. In this study, three-dimensional computer model of plaque formation and development for human carotid artery is developed. The three-dimensional blood flow is described by the Navier-Stokes equation, together with the continuity equation. Mass transfer within the blood lumen and through the arterial wall is coupled with the blood flow and is modeled by a convection-diffusion equation. The low-density lipoproteins transports in lumen of the vessel and through the vessel tissue are coupled by Kedem-Katchalsky equations. The inflammatory process is modeled using three additional reaction-diffusion partial differential equations. Fluid-structure interaction is used to estimate effective wall stress analysis. Plaque growth functions for volume progression are correlated with shear stress and effective wall stress distribution. We choose two specific patients from MRI study with significant plaque progression. Plaque volume progression using three time points for baseline, 3- and 12-month follow up is fitted. Our results for plaque localization correspond to low shear stress zone and we fitted parameters from our model using nonlinear least-square method. Determination of plaque location and composition, and computer simulation of progression in time for a specific patient shows a potential benefit for the prediction of disease progression. The proof of validity of three-dimensional computer modeling in the evaluation of atherosclerotic plaque burden may shift the clinical information of MRI from morphological assessment toward a functional tool. Understanding and prediction of the evolution of atherosclerotic plaques either into vulnerable or stable plaques are major tasks for the medical community. PMID:23354828

Filipovic, Nenad; Teng, Zhongzhao; Radovic, Milos; Saveljic, Igor; Fotiadis, Dimitris; Parodi, Oberdan

2013-06-01

252

An Update of Animal Models of Alzheimer Disease with a Reevaluation of Plaque Depositions  

PubMed Central

Animal models of Alzheimer disease (AD) are used to study the mechanisms underlying AD pathogenesis, genetic interactions with genes of interest, and environmental risk factors that cause sporadic AD as well as to test the therapeutic effects of AD drug-candidates on neuropathology and cognitive function. To attain a comparative view on the AD models developed, representative AD lines were selected and summarized with respect to transgenic constructs and AD-related pathology. In addition, age-dependent plaque deposition data available in the literature for six representative AD models such as Tg2576, PDAPP, TgAPP23, Tg-APPswe/PS1dE9, 3xTg-AD, and 5XFAD mice were reevaluated using a photographic plaque reference scale method that was introduced recently. Tg2576, PDAPP, and TgAPP23 mice, which carry the amyloid precursor protein (APP) transgene, produced initially slow, but progressively accelerated plaque deposition as they aged, resulting in logistic plaque deposition. In contrast, Tg-APPswe/PS1dE9 and 3xTg-AD mice, which carry both APP and PS1 transgenes, developed abruptly accelerated plaque formation from the beginning, resulting in logarithmic plaque deposition. 5XFAD mice, which also carry both the APP and PS1 transgenes, developed a logarithmic deposition beginning at 2 months. This comparative analysis suggests that AD models may be classified into two distinct plaque deposition groups, and that early plaque models such as APPswe/PS1dE9, 3xTg-AD and 5XFAD might be useful to study the biochemical aspects of APP metabolism, whereas late plaque models such as Tg2576, PDAPP, and TgAPP23 might be useful to study more physiological and environmental aspects of AD pathogenesis, which occur on a longer time scale. PMID:23833557

Lee, Jung-Eun

2013-01-01

253

Improving quality assurance for assembled COMS eye plaques using a pinhole gamma camera.  

PubMed

A quality assurance system has been designed to verify the location and strength of seeds loaded in a brachytherapy eye plaque. This system consists of (1) a pinhole camera in conjunction with a Lumisys ACR-2000i computed radiography (CR) unit to image the location and measure the relative strength of the seeds with autoradiography, and (2) a source strength jig with a survey meter to estimate the total activity of the seeds in the plaque. Five holders of different sizes were made for fixation of the COMS (Collaborative Ocular Melanoma Study) plaques (12, 14, 16, 18, and 20 mm) in the camera. The plaque-to-pinhole distance (dpp) has been optimized to be 30 mm to give approximately uniform intensity on the CR image for uniformly loaded COMS plaques. The pinhole-to-detector distance (dpd) can be kept at either 30 mm for 1:1 scale, or at larger distances for higher magnification. For a 1:1 scaling and pinhole diameter of 0.345 mm, useful images are obtained with time-activity product (mCi sec) ranging from 5 to 250 mCi sec. Within this range, the pinhole system is able to differentiate seed activities of >10%. The resulting pinhole autoradiograph is able to (1) confirm the correct number of seeds loaded in the plaque, (2) verify the proper sitting of the seeds in the silastic carrier and the plaque, (3) verify the relative activity distribution of the seeds loaded in the plaque, and (4) potentially evaluate the integrity of the seed. The source strength measurement system is able to measure the total strength of seeds in the plaque ranging from 10 to 80 mCi with an uncertainty of 5%. PMID:18975677

Beiki-Ardakani, Akbar; Jezioranski, John; Jaffray, David A; Young, Ivan

2008-10-01

254

The rhythmic expression of clock genes attenuated in human plaque-derived vascular smooth muscle cells  

PubMed Central

Background Acute myocardial infarction and stroke are more likely to occur in the early morning. Circadian pacemakers are considered to be involved in the process. Many peripheral tissues and cells also contain clock systems. In this study, we examined whether the primary cultured human plaque-derived vascular smooth muscle cells (VSMCs) process circadian rhythmicity; furthermore, we investigated the expression difference of clock genes between normal human carotid VSMCs and human plaque-derived VSMCs. Methods Fifty-six human carotid plaques provided the atherosclerotic tissue, and 21 samples yielded viable cultured primary VSMCs. The normal carotid VSMCs were cultured from donors’ normal carotids. The mRNA levels of the target genes were measured by Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Results After serum shock, both types of cells showed clear circadian expressions of Bmal1, Cry1, Cry2, Per1, Per2, Per3 and Rev-erb? mRNA; meanwhile the Clock mRNA show a rhythmic expression in plaque-derived SMCs but not in normal carotid VSMCs. The expression levels of these main clock genes were significantly attenuated in human plaque-derived VSMCs compared with normal human carotid VSMCs. The rhythm of Bmal1 mRNA in plaque-derived VSMCs was changed. Conclusion The present results demonstrate that the human plaque-derived VSMCs possess different circadian rhythmicity from that of normal carotid VSMCs. The rhythm changes of clock genes in plaque-derived VSMCs may be involved in the process of atherosclerosis and finally promote the rupture of plaque. PMID:24418196

2014-01-01

255

Fast plaque sizing and some applications of the technique in antibody feedback experiments.  

PubMed

A method has been devised to make rapid assessments of plaque size simultaneously with plaque enumeration. The method depends on an inexpensive and simple interfacing of a weighted counter to a microcomputer. Comparisons made between relative (weighted counter) and absolute (photographic) assessments of plaque size, show that the relationship is not linear. It has been shown that assay conditions must be rigidly controlled for valid size comparisons to be made. IgM and IgG PFC specific for sheep RBC, burro RBC and TNP-, in primary and secondary, active and adoptive responses, were used in these experiments. An application of the method in antibody feedback experiments is described. PMID:2140118

Dresser, D W

1990-05-01

256

3D Critical Plaque Wall Stress Is a Better Predictor of Carotid Plaque Rupture Sites Than Flow Shear Stress: An In Vivo MRI-Based 3D FSI Study  

PubMed Central

Atherosclerotic plaque rupture leading to stroke is the major cause of long-term disability as well as the third most common cause of mortality. Image-based computational models have been introduced seeking critical mechanical indicators, which may be used for plaque vulnerability assessment. This study extends the previous 2D critical stress concept to 3D by using in vivo magnetic resonance image (MRI) data of human atherosclerotic carotid plaques and 3D fluid-structure interaction (FSI) models to: identify 3D critical plaque wall stress (CPWS) and critical flow shear stress (CFSS) and to investigate their associations with plaque rupture. In vivo MRI data of carotid plaques from 18 patients scheduled for endarterectomy were acquired using histologically validated multicontrast protocols. Of the 18 plaques, histology-confirmed that six had prior rupture (group 1) as evidenced by presence of ulceration. The remaining 12 plaques (group 2) contained no rupture. The 3D multicomponent FSI models were constructed for each plaque to obtain 3D plaque wall stress (PWS) and flow shear stress (FSS) distributions. Three-dimensional CPWS and CFSS, defined as maxima of PWS and FSS from all vulnerable sites, were determined for each plaque to investigate their association with plaque rupture. Slice-based critical PWS and FSS were also calculated for all slices for more detailed analysis and comparison. The mean 3D CPWS of group 1 was 263.44 kPa, which was 100% higher than that from group 2 (132.77, p = 0.03984). Five of the six ruptured plaques had 3D CPWS sites, matching the histology-confirmed rupture sites with an 83% agreement. Although the mean 3D CFSS (92.94 dyn/cm2) for group 1 was 76% higher than that for group 2 (52.70 dyn / cm2), slice-based CFSS showed no significant difference between the two groups. Only two of the six ruptured plaques had 3D CFSS sites matching the histology-confirmed rupture sites with a 33% agreement. CFSS had a good correlation with plaque stenosis severity (R2 = 0.40 with an exponential function fitting 3D CFSS data). This in vivo MRI pilot study using plaques with and without rupture demonstrates that 3D critical plaque wall stress values are more closely associated with atherosclerotic plaque rupture then critical flow shear stresses. Critical wall stress values may become indicators of high risk sites of rupture. Future work with a larger population will establish a possible CPWS-based plaque vulnerability classification. PMID:20459195

Teng, Zhongzhao; Canton, Gador; Yuan, Chun; Ferguson, Marina; Yang, Chun; Huang, Xueying; Zheng, Jie; Woodard, Pamela K.

2010-01-01

257

Biomechanical modeling and morphology analysis indicates plaque rupture due to mechanical failure unlikely in atherosclerosis-prone mice.  

PubMed

Spontaneous plaque rupture in mouse models of atherosclerosis is controversial, although numerous studies have discussed so-called "vulnerable plaque" phenotypes in mice. We compared the morphology and biomechanics of two acute and one chronic murine model of atherosclerosis to human coronaries of the thin-cap fibroatheroma (TCFA) phenotype. Our acute models were apolipoprotein E-deficient (ApoE(-/-)) and LDL receptor-deficient (LDLr(-/-)) mice, both fed a high-fat diet for 8 wk with simultaneous infusion of angiotensin II (ANG II), and our chronic mouse model was the apolipoprotein E-deficient strain fed a regular chow diet for 1 yr. We found that the mouse plaques from all three models exhibited significant morphological differences from human TCFA plaques, including the plaque burden, plaque thickness, eccentricity, and amount of the vessel wall covered by lesion as well as significant differences in the relative composition of plaques. These morphological differences suggested that the distribution of solid mechanical stresses in the walls may differ as well. Using a finite-element analysis computational solid mechanics model, we computed the relative distribution of stresses in the walls of murine and human plaques and found that although human TCFA plaques have the highest stresses in the thin fibrous cap, murine lesions do not have such stress distributions. Instead, local maxima of stresses were on the media and adventitia, away from the plaque. Our results suggest that if plaque rupture is possible in mice, it may be driven by a different mechanism than mechanics. PMID:23203971

Campbell, Ian C; Weiss, Daiana; Suever, Jonathan D; Virmani, Renu; Veneziani, Alessandro; Vito, Raymond P; Oshinski, John N; Taylor, W Robert

2013-02-01

258

Ultrasonography reveals nail thickening in patients with chronic plaque psoriasis.  

PubMed

Nail psoriasis is usually investigated and diagnosed by clinical examination. Ultrasonography is a non-invasive imaging technique for studying soft tissue involvement. The objective of this study was to estimate nail involvement in patients with chronic plaque psoriasis by ultrasonography. Prevalence, clinical type and severity of nail involvement according to nail psoriasis and severity index (NAPSI) were investigated in 138 patients with psoriasis. The thickness of the plate and bed of the fingernails was measured in 54 patients with psoriasis, 46 healthy controls and 37 patients with chronic eczema, using an ultrasonographic system equipped with a frequency transducer of 18 MHz. The prevalence of nail psoriasis was 73 % (102 out of 138). Onycholysis and thickening of the nail plate were the most common clinical type affecting 56 and 50 % of patients, respectively; splinter haemorrhages was the less common involving 10 % of patients. The mean NAPSI score was 18.4 ± 17.5 (SD; range 0-107). The thickness of fingernail plate and bed was significantly higher in patients with psoriasis with nail disease compared to healthy controls and patients with chronic eczema (p < 0.001). There was a linear correlation between NAPSI and plate and bed nail thickness (r = 0.52 and r = 0.38, p = 0.001). Increased nail plate and bed thickness was observed also in patients with psoriasis without clinically apparent nail involvement. In conclusion, thickening of the nail is a common feature of nail psoriasis also in patients without clinically apparent nail involvement. PMID:23011659

Gisondi, P; Idolazzi, L; Girolomoni, G

2012-11-01

259

Polymeric Nanoparticle PET/MR Imaging Allows Macrophage Detection in Atherosclerotic Plaques  

E-print Network

Rationale: Myeloid cell content in atherosclerotic plaques associates with rupture and thrombosis. Thus, imaging of lesional monocytes and macrophages could serve as a biomarker of disease progression and therapeutic ...

Majmudar, M. D.

260

Using multimodal femtosecond CARS imaging to determine plaque burden in luminal atherosclerosis  

NASA Astrophysics Data System (ADS)

Luminal atherosclerosis imaging was demonstrated by multimodal femtosecond CARS microscopy (MM-CARS). Using a myocardial infarction-prone rabbit model of atherosclerosis, this study demonstrated the utility of multimodal CARS imaging in determining atherosclerotic plaque burden through two types of image analysis procedures. Firstly, multimodal CARS images were evaluated using a signal-intensity parameter based on intensity changes derived from the multi-channel data (e.g. TPEF, SHG and CARS) to classify plaque burden within the vessel. Secondly, the SHG images that mainly correspond to collagen fibrils were evaluated using a texture analysis model based on the first-order statistical (FOS) parameters of the image histogram. Correlation between FOS parameters of collagen images with atherosclerosis plaque burden was established. A preliminary study of using spectroscopic CARS in identifying the different lipid components within the plaque was also discussed.

Ko, Alex C.-T.; Mostaço-Guidolin, Leila B.; Ridsdale, Andrew; Pegoraro, Adrian F.; Smith, Michael S. D.; Slepkov, Aaron; Hewko, Mark D.; Kohlenberg, Elicia K.; Schattka, Bernie; Stolow, Albert; Sowa, Michael G.

2011-03-01

261

Improved chicken embryo cell culture plaque assay for scrub typhus rickettsiae.  

PubMed Central

The plaque technique for three strains of Rickettsia tsutsugamushi in chicken embryo cell cultures was greatly improved by modifying the trypsinizing procedure and employing homologous chicken serum in the overlay medium. Images PMID:412863

Woodman, D R; Grays, R; Weiss, E

1977-01-01

262

A method of cobalt addition to improve nickel plaque electrode performance  

NASA Astrophysics Data System (ADS)

The addition of cobalt to the surface of aerospace-quality sintered nickel plaque was observed to improve plate performance. Initially, substitution of cobalt metal powder for 5% of the nickel powder in sintered nickel plaque improved electrode performance during cycling in a LEO regime at 80% DoD in a boilerplate cell. A soak/resinter method was developed to reduce the amount required and limit cobalt addition to the plaque surface. A boilerplate cell containing these cobalt-enhanced nickel plates had higher capacity utilization then a 50 A h NiH 2 cell containing electrodes made from standard sintered nickel plaque over the temperature range -10 to +20°C.

Kuklinski, Jerry; Russell, Philip G.

263

Painting blood vessels and atherosclerotic plaques with an adhesive drug depot.  

PubMed

The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques. PMID:23236189

Kastrup, Christian J; Nahrendorf, Matthias; Figueiredo, Jose Luiz; Lee, Haeshin; Kambhampati, Swetha; Lee, Timothy; Cho, Seung-Woo; Gorbatov, Rostic; Iwamoto, Yoshiko; Dang, Tram T; Dutta, Partha; Yeon, Ju Hun; Cheng, Hao; Pritchard, Christopher D; Vegas, Arturo J; Siegel, Cory D; MacDougall, Samantha; Okonkwo, Michael; Thai, Anh; Stone, James R; Coury, Arthur J; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G

2012-12-26

264

46. VIEW OF BRONZE ENGINEERS/INSPECTORS PLAQUE LOCATED ON SOUTH SIDE ...  

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

46. VIEW OF BRONZE ENGINEERS/INSPECTORS PLAQUE LOCATED ON SOUTH SIDE OF WESTERN APPROACH WALL - Tomlinson Bridge, Spanning Quinnipiac River at Forbes Street (U.S. Route 1), New Haven, New Haven County, CT

265

Detection of morphological markers of vulnerable atherosclerotic plaque using multimodal spectroscopy  

E-print Network

Vulnerable plaques, which are responsible for most acute ischemic events, are presently invisible to x-ray angiography. Their primary morphological features include a thin or ulcerated fibrous cap, a large necrotic core, ...

Fitzmaurice, Maryann

266

In vivo Raman spectral pathology of human atherosclerosis and vulnerable plaque  

E-print Network

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 ...

Motz, Jason T.

267

Use of Frozen Chick and Duck Embryo Cells for Plaque Assays of Arboviruses and Rickettsiae.  

National Technical Information Service (NTIS)

Conditions for preparation, freezing, storing and plating of chick and duck embryo cell slurries are described. Comparisons of plaque assay sensitivity for fresh and previously frozen cells with Eastern equine encephalitis, Western equine encephalitis, Ve...

A. T. McManus, D. R. Parker, R. H. Kenyon, J. P. Kondig, G. A. Eddy

1974-01-01

268

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

PubMed

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

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

2014-03-01

269

Painting blood vessels and atherosclerotic plaques with an adhesive drug depot  

PubMed Central

The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques. PMID:23236189

Kastrup, Christian J.; Nahrendorf, Matthias; Figueiredo, Jose Luiz; Lee, Haeshin; Kambhampati, Swetha; Lee, Timothy; Cho, Seung-Woo; Gorbatov, Rostic; Iwamoto, Yoshiko; Dang, Tram T.; Dutta, Partha; Yeon, Ju Hun; Cheng, Hao; Pritchard, Christopher D.; Vegas, Arturo J.; Siegel, Cory D.; MacDougall, Samantha; Okonkwo, Michael; Thai, Anh; Stone, James R.; Coury, Arthur J.; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G.

2012-01-01

270

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

E-print Network

Cellularity of the fibrous caps of coronary atheromas, manifested by the infiltration of macrophages (average size, 20 to 30 [micrometer]), is thought to weaken the structural integrity of the cap and predispose plaques ...

Bouma, Brett E.

271

Tissue pH Determination for the Detection of Metabolically Active, Inflamed Vulnerable Plaques Using Near-Infrared Spectroscopy: An in-vitro Feasibility Study  

Microsoft Academic Search

Detection of vulnerable plaques as the underlying cause of myocardial infarction is at the center of attention in cardiology. We have previously shown that infiltration of inflammatory cells in atherosclerotic plaques renders these plaques relatively hot and acidic, with substantial plaque temperature and pH variation. The objective of this investigation was to determine whether near-infrared diffuse reflectance spectroscopy (NIRS) could

Tania Khan; Babs Soller; Morteza Naghavi; Ward Casscells

2005-01-01

272

High prevalence of human cytomegalovirus in carotid atherosclerotic plaques obtained from Russian patients undergoing carotid endarterectomy  

PubMed Central

Background Human cytomegalovirus (HCMV) infection is associated with cardiovascular disease (CVD) but the role of this virus in CVD progression remains unclear. We aimed to examine the HCMV serostatus in Russian patients (n?=?90) who had undergone carotid endarterectomy (CEA) and controls (n?=?82) as well as to determine the prevalence of HCMV immediate early (IE) and late (LA) antigens in carotid atherosclerotic plaques obtained from 89 patients. In addition, we sought to determine whether HCMV infection was associated with inflammatory activity in the plaque by quantifying infiltrating CD3 and CD68 positive cells and 5-LO immunoreactivity. Methods HCMV serology was assessed with ELISA and immunohistochemistry staining was performed to detect HCMV antigens, CD3, CD68 and 5-LO reactivity. The Fisher’s exact test was used to compare i) seroprevalence of HCMV IgG between patients and controls and ii) HCMV-positive or –negative to that of CD3, CD68 and 5-LO immunoreactive cells in plaque samples. The student-t test was performed to connote the significance level of mean optical density between patients and controls. Results The seroprevalence for HCMV IgG was high in both patients and controls (99% and 98%, respectively). Controls had significantly higher IgG titers for HCMV compared with patients (p?=?0.0148). Strikingly, we found a high prevalence of HCMV antigens in atherosclerotic plaques; 57/89 (64%) and 47/87 (54%) were HCMV IE and LA positive, respectively. Most plaques had rather low HCMV reactivity with distinct areas of HCMV-positive cells mainly detected in shoulder regions of the plaques, but also in the area adjacent to the necrotic core and fibrous cap. In plaques, the cellular targets for HCMV infection appeared to be mainly macrophages/foam cells and smooth muscle cells. HCMV-positive plaques trended to be associated with increased numbers of CD68 positive macrophages and CD3 positive T cells, while 5-LO reactivity was high in both HCMV-positive and HCMV-negative plaques. Conclusions In Russian patients undergoing CEA, HCMV proteins are abundantly expressed in carotid plaques and may contribute to the inflammatory response in plaques via enhanced infiltration of CD68 and CD3 cells. PMID:24229441

2013-01-01

273

Association of the Sirtuin and Mitochondrial Uncoupling Protein Genes with Carotid Plaque  

PubMed Central

Objective Sirtuins (SIRTs) and mitochondrial uncoupling proteins (UCPs) have been implicated in cardiovascular diseases through the control of reactive oxygen species production. This study sought to investigate the association between genetic variants in the SIRT and UCP genes and carotid plaque. Methods In a group of 1018 stroke-free subjects from the Northern Manhattan Study with high-definition carotid ultrasonography and genotyping, we investigated the associations of 85 single nucleotide polymorphisms (SNPs) in the 11 SIRT and UCP genes with the presence and number of carotid plaques, and evaluated interactions of SNPs with sex, smoking, diabetes and hypertension as well as interactions between SNPs significantly associated with carotid plaque. Results Overall, 60% of subjects had carotid plaques. After adjustment for demographic and vascular risk factors, T-carriers of the SIRT6 SNP rs107251 had an increased risk for carotid plaque (odds ratio, OR?=?1.71, 95% CI?=?1.23–2.37, Bonferroni-corrected p?=?0.03) and for a number of plaques (rate ratio, RR?=?1.31, 1.18–1.45, Bonferroni-corrected p?=?1.4×10?5), whereas T-carriers of the UCP5 SNP rs5977238 had an decreased risk for carotid plaque (OR?=?0.49, 95% CI?=?0.32–0.74, Bonferroni-corrected p?=?0.02) and plaque number (RR?=?0.64, 95% CI?=?0.52–0.78, Bonferroni-corrected p?=?4.9×10?4). Some interactions with a nominal p?0.01 were found between sex and SNPs in the UCP1 and UCP3 gene; between smoking, diabetes, hypertension and SNPs in UCP5 and SIRT5; and between SNPs in the UCP5 gene and the UCP1, SIRT1, SIRT3, SIRT5, and SIRT6 genes in association with plaque phenotypes. Conclusion We observed significant associations between genetic variants in the SIRT6 and UCP5 genes and atherosclerotic plaque. We also found potential effect modifications by sex, smoking and vascular risk factors of the SIRT/UCP genes in the associations with atherosclerotic plaque. Further studies are needed to validate our observations. PMID:22087257

Wang, Liyong; Cabral, Digna; Beecham, Ashley; McClendon, Mark S.; Luca, Corneliu C.; Blanton, Susan H.; Sacco, Ralph L.; Rundek, Tatjana

2011-01-01

274

The relationship of amyloid plaques to cerebral capillaries in Alzheimer's disease.  

PubMed Central

The authors examined the hypothesis that senile plaques of Alzheimer's disease (AD) are formed by abnormal leakage of amyloidogenic precursors from brain capillaries by quantitative analysis of the spatial relationship between capillaries and amyloid plaques. Vibratome sections (40 mu) of the hippocampus, including the entorhinal cortex, obtained at autopsy from AD subjects, were immunostained with a monoclonal antibody to beta-protein and counterstained with rabbit serum to either the glucose transporter protein, a cerebral endothelial marker, or collagen type IV, a basal lamina marker. The authors found that while 60% to 77% of amyloid plaques were associated with capillaries, only 8% to 13% were penetrated by a capillary, the remainder being adjacent. To test whether 1) the area occupied by amyloid plaques or 2) the border zone (10-mu rim) surrounding amyloid plaques has a statistically higher density of capillaries than 3) the remaining gray matter, similarly double-stained 6-mu sections from five AD subjects were photographed and the capillary densities in the three areas calculated. Capillary density was significantly lower in 1) than in 3) and higher in 2) than in 3), while the combined area of 1) and 2) showed the same capillary density as 3). Similar results were obtained by using either the glucose transporter or the collagen type IV antibodies. Because capillary density is low within, and high in regions that immediately surround amyloid plaques, our findings suggest that amyloid plaques exclude capillaries or lead to their degeneration, or both. The latter possibility was investigated by triple-staining tissue sections with antibodies to beta-protein, glucose transporter, and collagen type IV. The proportion of glucose transporter-negative capillaries was not significantly different in areas inside or outside of the plaques. Thus, the authors found no evidence of basal lamina remnants consistent with capillary degeneration preferential to amyloid plaques. Although a small number of capillaries showed amyloid deposition just beneath the basement membrane, the authors conclude that capillaries play only a limited direct role, if any, in amyloid plaque formation, and that the apparent association of amyloid plaques and capillaries is no more than a chance contact. Images Figure 1 Figure 3 PMID:2260630

Kawai, M.; Kalaria, R. N.; Harik, S. I.; Perry, G.

1990-01-01

275

Keeping an eye on the ring: COMS plaque loading optimization for improved dose conformity and homogeneity  

PubMed Central

Purpose To improve tumor dose conformity and homogeneity for COMS plaque brachytherapy by investigating the dosimetric effects of varying component source ring radionuclides and source strengths. Material and methods The MCNP5 Monte Carlo (MC) radiation transport code was used to simulate plaque heterogeneity-corrected dose distributions for individually-activated source rings of 14, 16 and 18 mm diameter COMS plaques, populated with 103Pd, 125I and 131Cs sources. Ellipsoidal tumors were contoured for each plaque size and MATLAB programming was developed to generate tumor dose distributions for all possible ring weighting and radionuclide permutations for a given plaque size and source strength resolution, assuming a 75 Gy apical prescription dose. These dose distributions were analyzed for conformity and homogeneity and compared to reference dose distributions from uniformly-loaded 125I plaques. The most conformal and homogeneous dose distributions were reproduced within a reference eye environment to assess organ-at-risk (OAR) doses in the Pinnacle3 treatment planning system (TPS). The gamma-index analysis method was used to quantitatively compare MC and TPS-generated dose distributions. Results Concentrating > 97% of the total source strength in a single or pair of central 103Pd seeds produced the most conformal dose distributions, with tumor basal doses a factor of 2-3 higher and OAR doses a factor of 2-3 lower than those of corresponding uniformly-loaded 125I plaques. Concentrating 82-86% of the total source strength in peripherally-loaded 131Cs seeds produced the most homogeneous dose distributions, with tumor basal doses 17-25% lower and OAR doses typically 20% higher than those of corresponding uniformly-loaded 125I plaques. Gamma-index analysis found > 99% agreement between MC and TPS dose distributions. Conclusions A method was developed to select intra-plaque ring radionuclide compositions and source strengths to deliver more conformal and homogeneous tumor dose distributions than uniformly-loaded 125I plaques. This method may support coordinated investigations of an appropriate clinical target for eye plaque brachytherapy. PMID:23346146

Gagne, Nolan L.; Cutright, Daniel R.

2012-01-01

276

Inflammatory Multiple-Sclerosis Plaques Generate Characteristic Metabolic Profiles in Cerebrospinal Fluid  

PubMed Central

Background Multiple sclerosis (MS), an inflammatory disease of the central nervous system, manifests itself in numerous forms and stages. A number of brain metabolic alterations have been reported for MS patients vs. control subjects. However, metabolite profiles of cerebrospinal fluid (CSF) are not consistent among the published MS studies, most probably due to variations in the patient cohorts studied. We undertook the first investigation of highly homogeneous MS patient cohorts to determine characteristic effects of inflammatory MS plaques on the CSF metabolome, including only patients with clinically isolated syndrome (CIS) with or without inflammatory brain plaques, and controls. Methodology/Principal Findings CSF obtained by lumbar puncture was analyzed by proton magnetic resonance spectroscopy. 27 metabolites were quantified. Differences between groups of control subjects (n?=?10), CIS patients with (n?=?21) and without (n?=?12) inflammatory plaques were evaluated by univariate statistics and principal component analysis (PCA). Seven metabolites showed statistically significant inter-group differences (p<0.05). Interestingly, a significant increase in ?-hydroxyisobutyrate (BHIB) was detected in CIS with vs. without active plaques, but not when comparing either CIS group with control subjects. Moreover, a significant correlation was found, for the first time, between CSF lactate concentration and the number of inflammatory MS brain plaques. In contrast, fructose concentrations were equally enhanced in CIS with or without active plaques. PCA based on all 27 metabolites yielded group-specific clusters. Conclusions/Significance CSF metabolic profiles suggest a close link between MS plaque activity in CIS patients on the one hand and organic-acid metabolism on the other. Our detection of increased BHIB levels points to a hitherto unsuspected role for this compound in MS with active plaques, and serves as a basis for further investigation. The metabolic effects described in our study are crucial elements in the explanation of biochemical mechanisms involved in specific MS manifestations. PMID:17611627

Lutz, Norbert W.; Viola, Angele; Malikova, Irina; Confort-Gouny, Sylviane; Audoin, Bertrand; Ranjeva, Jean-Philippe; Pelletier, Jean; Cozzone, Patrick J.

2007-01-01

277

Multiaxial Mechanical Characteristics of Carotid Plaque Analysis by Multiarray Echotracking System  

Microsoft Academic Search

Background and Purpose—Carotid plaque rupture depends on the various types of mechanical stresses. Our objective was to determine the multiaxial mechanical characteristics of atherosclerotic plaque and adjacent segment of the common carotid artery. Methods—A novel noninvasive echotracking system was used to measure intima-media thickness, diameter, pulsatile strain, and distensibility at 128 sites on a 4-cm long common carotid artery segment.

Anna Paini; Pierre Boutouyrie; David Calvet; Mustapha Zidi; Enrico Agabiti-Rosei; Stephane Laurent

278

NiCo alloy plaque for cathode of Ni-Cd battery  

Microsoft Academic Search

The present invention relates generally to Ni-Cd batteries, and, in particular, relates to the plaque material attached to the cathode. Because of the wide use of nickel-cadmium batteries, the corrosion rates of nickel and nickel-cobalt alloys are of interest to nickel-cadmium battery electrochemical theory and its technology. The plaque material of the cathode consists of a Ni-Co alloy in solid

J. J. Lander

1986-01-01

279

Relation of arterial geometry to luminal narrowing and histologic markers for plaque vulnerability: the remodeling paradox  

Microsoft Academic Search

Objective. To relate local arterial geometry with markers that are thought to be related to plaque rupture.Background. Plaque rupture often occurs at sites with minor luminal stenosis and has retrospectively been characterized by colocalization of inflammatory cells. Recent studies have demonstrated that luminal narrowing is related with the mode of atherosclerotic arterial remodeling.Methods. We obtained 1,521 cross section slices at

Gerard Pasterkamp; Arjan H Schoneveld; Allard C van der Wal; Christian C Haudenschild; Ruud J. G Clarijs; Anton E Becker; Berend Hillen; Cornelius Borst

1998-01-01

280

Ultrastructural localization of butyrylcholinesterase in senile plaques in the brains of aged and Alzheimer disease patients  

Microsoft Academic Search

Histochemical localization of butyrylcholinesterase has been carried out in primitive, perivascular, and classic plaques in\\u000a the brains of both nondemented and Alzheimer disease (AD) patients. Butyrylcholinesterase histochemistry has been compared\\u000a to amyloid ?-protein (A?P) immunocytochemistry in adjacent sections. In small primitive plaques, most of the butyrylcholinesterase\\u000a reaction product appears ultrastructurally located over plasma membranes of healthy-looking cell processes. In more

Pilar Gómez-Ramos; M. A. Morán

1997-01-01

281

Early-onset formation of parenchymal plaque amyloid abrogates cerebral microvascular amyloid accumulation in transgenic mice.  

PubMed

The fibrillar assembly and deposition of amyloid ? (A?) protein, a key pathology of Alzheimer disease, can occur in the form of parenchymal amyloid plaques and cerebral amyloid angiopathy (CAA). Familial forms of CAA exist in the absence of appreciable parenchymal amyloid pathology. The molecular interplay between parenchymal amyloid plaques and CAA is unclear. Here we investigated how early-onset parenchymal amyloid plaques impact the development of microvascular amyloid in transgenic mice. Tg-5xFAD mice, which produce non-mutated human A? and develop early-onset parenchymal amyloid plaques, were bred to Tg-SwDI mice, which produce familial CAA mutant human A? and develop cerebral microvascular amyloid. The bigenic mice presented with an elevated accumulation of A? and fibrillar amyloid in the brain compared with either single transgenic line. Tg-SwDI/Tg-5xFAD mice were devoid of microvascular amyloid, the prominent pathology of Tg-SwDI mice, but exhibited larger parenchymal amyloid plaques compared with Tg-5xFAD mice. The larger parenchymal amyloid deposits were associated with a higher loss of cortical neurons and elevated activated microglia in the bigenic Tg-SwDI/Tg-5xFAD mice. The periphery of parenchymal amyloid plaques was largely composed of CAA mutant A?. Non-mutated A? fibril seeds promoted CAA mutant A? fibril formation in vitro. Further, intrahippocampal administration of biotin-labeled CAA mutant A? peptide accumulated on and adjacent to pre-existing parenchymal amyloid plaques in Tg-5xFAD mice. These findings indicate that early-onset parenchymal amyloid plaques can serve as a scaffold to capture CAA mutant A? peptides and prevent their accumulation in cerebral microvessels. PMID:24828504

Xu, Feng; Kotarba, AnnMarie E; Ou-Yang, Ming-Hsuan; Fu, Ziao; Davis, Judianne; Smith, Steven O; Van Nostrand, William E

2014-06-20

282

Cardiovascular magnetic resonance parameters of atherosclerotic plaque burden improve discrimination of prior major adverse cardiovascular events  

PubMed Central

Aims Patients with prior major cardiovascular or cerebrovascular events (MACE) are more likely to have future recurrent events independent of traditional cardiovascular disease risk factors. The purpose of this study was to determine if patients with traditional risk factors and prior MACE had increased cardiovascular magnetic resonance (CMR) plaque burden measures compared to patients with risk factors but no prior events. Methods and Results Black blood carotid and thoracic aorta images were obtained from 195 patients using a rapid extended coverage turbo spin echo sequence. CMR measures of plaque burden were obtained by tracing lumen and outer vessel wall contours. Patients with prior MACE had significantly higher MR plaque burden (wall thickness, wall area and normalized wall index) in carotids and thoracic aorta compared to those without prior MACE (Wall thickness carotids: 1.03 ± 0.03 vs. 0.93± 0.03, p = 0.001; SD wall thickness carotids: 0.137 ± 0.0008 vs. 0.102 ± 0.0004, p < 0.001; wall thickness aorta: 1.63 ± 0.10 vs. 1.50 ± 0.04, p = 0.009; SD wall thickness aorta: 0.186 ± 0.035 vs. 0.139 ± 0.012, p = 0.009 respectively). Plaque burden (wall thickness) and plaque eccentricity (standard deviation of wall thickness) of carotid arteries were associated with prior MACE after adjustment for age, sex, and traditional risk factors. Area under ROC curve (AUC) for discriminating prior MACE improved by adding plaque eccentricity to models incorporating age, sex, and traditional CVD risk factors as model inputs (AUC = 0.79, p = 0.05). Conclusion A greater plaque burden and plaque eccentricity is prevalent among patients with prior MACE. PMID:19393089

Mani, Venkatesh; Muntner, Paul; Gidding, Samuel S; Aguiar, Silvia H; El Aidi, Hamza; Weinshelbaum, Karen B; Taniguchi, Hiroaki; van der Geest, Rob; Reiber, Johan HC; Bansilal, Sameer; Farkouh, Michael; Fuster, Valentin; Postley, John E; Woodward, Mark; Fayad, Zahi A

2009-01-01

283

Symbiotic Relationship of Veillonella alcalescens and Streptococcus mutans in Dental Plaque in Gnotobiotic Rats  

Microsoft Academic Search

The symbiosis of two Streptococcus mutans strains differing in carbohydrate metabolism, and a strain of Veillonella alcalescens was studied in dental plaque in gnotobiotic rats. The lactate dehydrogenase in S. mutans FIL but not in C 67-1, is independent on fructose 1,6-diphosphate. S. mutans FIL was found to produce significantly more lactic acid in plaque than C 67-1. Both strains

J. S. van der Hoeven; A. I. Toorop; F. H. M. Mikx

1978-01-01

284

The Effect of Different Concentrations of Citrate in Drinks on Plaque pH  

Microsoft Academic Search

The effect of 0.1, 0.2 and 0.4% citrate in 10% sucrose solutions on the plaque pH in vivo was tested in 20 volunteers using the plaque harvesting technique. Results showed that the pH response for the three test solutions with citrate was significantly less compared with that for 10% sucrose (positive control) alone (p < 0.05). Mean areas under the

M. A. Pollard; M. S. Duggal; M. E. J. Curzon

1993-01-01

285

Factors affecting iron plaque on the roots of Phragmites australis (Cav.) Trin. ex Steudel  

Microsoft Academic Search

Phragmites australis (the common reed) was collected at six sites in southern Qubec and Ontario, Canada, in order to study the accumulation of\\u000a iron plaque on the roots. The deposition of iron oxides on roots ofP. australis did not correlate directly with soil measurements; however, the amounts of iron-bound-to-carbonates fraction of the soil\\/sediment,\\u000a responsible for the iron plaque accumulation, correlated

L. St-Cyr; A. A. Crowder

1989-01-01

286

The Influence of Surface Free-energy on Planimetric Plaque Growth in Man  

Microsoft Academic Search

The purpose of this study was to examine the change in plaque area over nine days in vivo on four materials with different surface free-energies (s.f.e.). Twelve healthy dental students participated in a crossover, split-mouth, double-blind study. Supragingival plaque formation was recorded over a nine-day period, on four different materials: fluorethylenepropylene (Teflon) (FEP), parafilm (PAR), cellulose acetate (CA), and enamel

M. Quirynen; M. Marechal; H. J. Busscher; A. H. Weerkamp; J. Arends; P. L. Darius; D. van Steenberghe

1989-01-01

287

3D Ultrasound System for Analysis of Carotid Plaque Progression and Regression  

Microsoft Academic Search

Morphological characterization of carotid plaques has been used for risk stratification and evaluation of response to therapy, evaluation of new risk factors, genetic research, and for quantifying effects of new anti-atherosclerotic therapies. We developed a 3D US system that allows detailed studies of carotid plaques in 3D. Our software includes 3D reconstruction, viewing, and manual and semi-automated segmentation of carotid

A. Fenster; B. Chiu; A. Landry; J. D. Spence; G. E. Parraga

2006-01-01

288

Effects of Chewing Sorbitol Gum and Paraffin on Human Interproximal Plaque pH  

Microsoft Academic Search

The effects of chewing sorbitol-containing gum and paraffin upon human interproximal plaque pH responses after consumption of a jelly donut were investigated in this study. Prolonged plaque pH responses were observed following consumption of the jelly donut. Dramatic rises in pH resulted when sorbitol gum and paraffin were chewed 15 min after consumption of the donut. Ten minutes of chewing

M. E. Jensen

1986-01-01

289

Inflammatory Biomarkers in Atherosclerosis: Pentraxin 3 Can Become a Novel Marker of Plaque Vulnerability  

PubMed Central

Inflammation is crucially involved in the development of carotid plaques. We examined the relationship between plaque vulnerability and inflammatory biomarkers using intraoperative blood and tissue specimens. We examined 58 patients with carotid stenosis. Following carotid plaque magnetic resonance imaging, 41 patients underwent carotid artery stenting (CAS) and 17 underwent carotid endarterectomy (CEA). Blood samples were obtained from the femoral artery (systemic) and common carotid artery immediately before and after CAS (local). Seventeen resected CEA tissue samples were embedded in paraffin, and histopathological and immunohistochemical analyses for IL-6, IL-10, E-selectin, adiponectin, and pentraxin 3 (PTX3) were performed. Serum levels of IL-6, IL-1?, IL-10, TNF?, E-selectin, VCAM-1, adiponectin, hs-CRP, and PTX3 were measured by multiplex bead array system and ELISA. CAS-treated patients were classified as stable plaques (n?=?21) and vulnerable plaques (n?=?20). The vulnerable group showed upregulation of the proinflammatory cytokines (IL-6 and TNF?), endothelial activation markers (E-selectin and VCAM-1), and inflammation markers (hs-CRP and PTX3) and downregulation of the anti-inflammatory markers (adiponectin and IL-10). PTX3 levels in both systemic and intracarotid samples before and after CAS were higher in the vulnerable group than in the stable group. Immunohistochemical analysis demonstrated that IL-6 was localized to inflammatory cells in the vulnerable plaques, and PTX3 was observed in the endothelial and perivascular cells. Our findings reveal that carotid plaque vulnerability is modulated by the upregulation and downregulation of proinflammatory and anti-inflammatory factors, respectively. PTX3 may thus be a potential predictive marker of plaque vulnerability. PMID:24936646

Shindo, Akihiro; Tanemura, Hiroshi; Yata, Kenichiro; Hamada, Kazuhide; Shibata, Masunari; Umeda, Yasuyuki; Asakura, Fumio; Toma, Naoki; Sakaida, Hiroshi; Fujisawa, Takao; Taki, Waro; Tomimoto, Hidekazu

2014-01-01

290

Identification of carotid plaque tissue properties using an experimental-numerical approach.  

PubMed

A biomechanical stress analysis could help to identify carotid plaques that are vulnerable to rupture, and hence reduce the risk of thrombotic strokes. Mechanical stress predictions critically depend on the plaque's constitutive properties, and the present study introduces a concept to derive viscoelastic parameters through an experimental-numerical approach. Carotid plaques were harvested from two patients during carotid endarterectomy (CEA), and, in total, nine test specimens were investigated. A novel in-vitro mechanical testing protocol, which allows for dynamic testing, keeping the carotid plaque components together, was introduced. Macroscopic pictures overlaid by histological stains allowed for the segmentation of plaque tissues, in order to develop high-fidelity and low-fidelity Finite Element Method (FEM) models of the test specimens. The FEM models together with load-displacement data from the mechanical testing were used to extract constitutive parameters through inverse parameter estimation. The applied inverse parameter estimation runs in stages, first addressing the hyperelastic parameters then the viscoelastic ones. Load-displacement curves from the mechanical testing showed strain stiffening and viscoelasticity, as is expected for both normal and diseased carotid tissue. The estimated constitutive properties of plaque tissue were comparable to previously reported studies. Due to the highly non-linear elasticity of vascular tissue, the applied parameter estimation approach is, as with many similar approaches, sensitive to the initial guess of the parameters. PMID:23790614

Heiland, Vincent M; Forsell, Caroline; Roy, Joy; Hedin, Ulf; Gasser, T Christian

2013-11-01

291

Acoustic radiation force impulse imaging of vulnerable plaques: a finite element method parametric analysis  

PubMed Central

Plaque rupture is the most common cause of complications such as stroke and coronary heart failure. Recent histopathological evidence suggests that several plaque features, including a large lipid core and a thin fibrous cap, are associated with plaques most at risk for rupture. Acoustic Radiation Force Impulse (ARFI) imaging, a recently developed ultrasound-based elasticity imaging technique, shows promise for imaging these features noninvasively. Clinically, this could be used to distinguish vulnerable plaques, for which surgical intervention may be required, from those less prone to rupture. In this study, a parametric analysis using Finite-Element Method (FEM) models was performed to simulate ARFI imaging of five different carotid artery plaques across a wide range of material properties. It was demonstrated that ARFI could resolve the softer lipid pool from the surrounding, stiffer media and fibrous cap and was most dependent upon the stiffness of the lipid pool component. Stress concentrations due to an ARFI excitation were located in the media and fibrous cap components. In all cases, the maximum Von Mises stress was < 1.2 kPa. In comparing these results with others investigating plaque rupture, it is concluded that while the mechanisms may be different, the Von Mises stresses imposed by ARFI are orders of magnitude lower than the stresses associated with blood pressure. PMID:23122224

Doherty, Joshua R.; Dumont, Douglas M.; Trahey, Gregg E.; Palmeri, Mark L.

2012-01-01

292

A haemolytic plaque forming assay for identifying cells producing anti-DNA antibodies.  

PubMed Central

A murine hybridoma cell line (aDNA35I9) secreting anti-DNA antibodies was used as a model for haemolytic plaque forming cells in an assay where DNA-conjugated sheep red blood cells (DNA-SRBC) were used as target cells. DEAE-dextran, employed to abolish the anti-complementary activity of agar gel, completely inhibited anti-DNA plaques. This problem was solved by using agarose instead of agar. Since the occurrence of small plaques may make reading of the test difficult, it was established that plaque size could be increased by decreasing the antigen density on the target cells. Free DNA in the gel inhibited plaque formation, indicating the specificity of the assay. Spleen cells from mice of the strains MRL/MP and NZB/W which are known to develop a stage of autoimmunity, produced plaques in numbers which were correlated to the age of the mice and to the anti-DNA antibody level in serum. PMID:3066539

Loftager, M K; H?ier-Madsen, M; Koch, C; Andersen, V

1988-01-01

293

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

NASA Astrophysics Data System (ADS)

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.

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

2010-03-01

294

Carotid Plaque Assessment using Fast 3D Isotropic-Resolution Black-Blood MRI  

PubMed Central

Black-blood MRI is a promising tool for carotid atherosclerotic plaque burden assessment and compositional analysis. However, current sequences are limited by large slice thickness. Accuracy of measurement can be improved by moving to isotropic imaging but can be challenging for patient compliance due to long scan times. We present a fast isotropic high spatial resolution (0.7×0.7×0.7mm) 3D black-blood sequence (3D-MERGE) covering the entire cervical carotid arteries within 2 minutes thus ensuring patient compliance and diagnostic image quality. The sequence is optimized for vessel wall imaging of the carotid bifurcation based on its signal properties. The optimized sequence is validated on patients with significant carotid plaque. Quantitative plaque morphology measurements and SNR measures show that 3D MERGE provides good blood suppression and comparable plaque burden measurements to existing MRI protocols. 3D-MERGE is a promising new tool for fast and accurate plaque burden assessment in patients with atherosclerotic plaque. PMID:20941742

Balu, Niranjan; Yarnykh, Vasily L.; Chu, Baocheng; Wang, Jinnan; Hatsukami, Thomas; Yuan, Chun

2010-01-01

295

Impaired Spine Stability Underlies Plaque-Related Spine Loss in an Alzheimer's Disease Mouse Model  

PubMed Central

Dendritic spines, the site of most excitatory synapses in the brain, are lost in Alzheimer’s disease and in related mouse models, undoubtedly contributing to cognitive dysfunction. We hypothesized that spine loss results from plaque-associated alterations of spine stability, causing an imbalance in spine formation and elimination. To investigate effects of plaques on spine stability in vivo, we observed cortical neurons using multiphoton microscopy in a mouse model of amyloid pathology before and after extensive plaque deposition. We also observed age-matched nontransgenic mice to study normal effects of aging on spine plasticity. We found that spine density and structural plasticity are maintained during normal aging. Tg2576 mice had normal spine density and plasticity before plaques appeared, but after amyloid pathology is established, severe disruptions were observed. In control animals, spine formation and elimination were equivalent over 1 hour of observation (?5% of observed spines), resulting in stable spine density. However, in aged Tg2576 mice spine elimination increased, specifically in the immediate vicinity of plaques. Spine formation was unchanged, resulting in spine loss. These data show a small population of rapidly changing spines in adult and even elderly mouse cortex; further, in the vicinity of amyloid plaques, spine stability is markedly impaired leading to loss of synaptic structural integrity. PMID:17717139

Spires-Jones, Tara L.; Meyer-Luehmann, Melanie; Osetek, Jennifer D.; Jones, Phillip B.; Stern, Edward A.; Bacskai, Brian J.; Hyman, Bradley T.

2007-01-01

296

Thymidine plaque autoradiography of thymidine kinase-positive and thymidine kinase-negative herpesviruses  

SciTech Connect

Plaques formed by herpes simplex virus (HSV), pseudorabies virus, and varicella-zoster virus were studied by plaque autoradiography after (/sup 14/C)thymidine labeling. Standard thymidine kinase-positive (TK+) viruses and TK- mutants of HSV types 1 and 2 and pseudorabies virus were studied, including cell cultured viruses and viruses isolated from animals. Autoradiography was performed with X-ray film with an exposure time of 5 days. After development of films, TK+ plaques showed dark rims due to isotope incorporation, whereas TK- plaques were minimally labeled. Plaque autoradiography of stock TK- viruses showed reversion frequencies to the TK+ phenotype of less than 10(-3). Autoradiography indicated that TK- virus retained the TK- phenotype after replication in vivo. In addition, it was shown that TK- HSV could be isolated from mouse trigeminal ganglion tissue after corneal inoculation of TK- HSV together with TK+ HSV. The plaque autoradiographic procedure was very useful to evaluate proportions of TK+ and TK- virus present in TK+-TK- virus mixtures.

Tenser, R.B.; Jones, J.C.; Ressel, S.J.; Fralish, F.A.

1983-01-01

297

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

PubMed Central

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

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

298

Homocysteine and Carotid Plaque Stability: A Cross-Sectional Study in Chinese Adults  

PubMed Central

Background and Purpose This study aimed to explore the possible association of plasma total homocysteine with carotid plaque stability. Methods A cross-sectional study was conducted from 2010 to 2011. A stratified random sample of 2,919 Chinese participants aged 40 years or older was enrolled. Plasma total homocysteine levels were measured and carotid plaques were evaluated by ultrasonography. Logistic regression model was used to analyze the association of homocysteine levels to the progression of carotid plaque development, while adjusting for demographics and vascular risk factors. Results The mean level of plasma homocysteine in the subjects was 14.9 µmol/l. Along with increase in homocysteine level, the risk of advanced carotid plaque elevated (odds ratio?=?1.28; 95% confidence interval?=?1.09–1.51) after adjusting for age, sex, and other potential confounders. Stratified by sex, higher homocysteine level was strongly associated with advanced carotid plaque in men (OR?=?1.41; 95% confidence interval?=?1.17–1.70), but not in women. Conclusion The findings suggest that plasma level of homocysteine may be associated with advanced carotid plaque, which constitutes high risks of stroke, in male Chinese adults. PMID:24736609

Liu, Chao; Gao, Xiang; Wang, Anxin; Guo, Yuming; Li, Wen; Zhao, Xingquan; Liang, Wannian

2014-01-01

299

High expression of genes for calcification-regulating proteins in human atherosclerotic plaques.  

PubMed Central

Calcification is common in atheromatous plaques and may contribute to plaque rupture and subsequent thrombosis. However, little is known about the mechanisms which regulate the calcification process. Using in situ hybridization and immunohistochemistry we show that two bone-associated proteins, osteopontin (OP) and matrix Gla protein (MGP), are highly expressed in human atheromatous plaques. High levels of OP mRNA and protein were found in association with necrotic lipid cores and areas of calcification. The predominant cell type in these areas was the macrophage-derived foam cell, although some smooth muscle cells could also be identified. MGP was expressed uniformly by smooth muscle cells in the normal media and at high levels in parts of the atheromatous intima. Highest levels of this matrix-associated protein were found in lipid-rich areas of the plaque. The pattern of expression of these two genes contrasted markedly with that of calponin and SM22 alpha, genes expressed predominantly by differentiated smooth muscle cells and whose expression was generally confined to the media of the vessel. The postulated function of OP and MGP as regulators of calcification in bone and the high levels and colocalization of both in atheromatous plaques suggest they have an important role in plaque pathogenesis and stability. Images PMID:8200973

Shanahan, C M; Cary, N R; Metcalfe, J C; Weissberg, P L

1994-01-01

300

Acoustic radiation force impulse imaging of vulnerable plaques: a finite element method parametric analysis.  

PubMed

Plaque rupture is the most common cause of complications such as stroke and coronary heart failure. Recent histopathological evidence suggests that several plaque features, including a large lipid core and a thin fibrous cap, are associated with plaques most at risk for rupture. Acoustic Radiation Force Impulse (ARFI) imaging, a recently developed ultrasound-based elasticity imaging technique, shows promise for imaging these features noninvasively. Clinically, this could be used to distinguish vulnerable plaques, for which surgical intervention may be required, from those less prone to rupture. In this study, a parametric analysis using Finite Element Method (FEM) models was performed to simulate ARFI imaging of five different carotid artery plaques across a wide range of material properties. It was demonstrated that ARFI imaging could resolve the softer lipid pool from the surrounding, stiffer media and fibrous cap and was most dependent upon the stiffness of the lipid pool component. Stress concentrations due to an ARFI excitation were located in the media and fibrous cap components. In all cases, the maximum Von Mises stress was<1.2 kPa. In comparing these results with others investigating plaque rupture, it is concluded that while the mechanisms may be different, the Von Mises stresses imposed by ARFI imaging are orders of magnitude lower than the stresses associated with blood pressure. PMID:23122224

Doherty, Joshua R; Dumont, Douglas M; Trahey, Gregg E; Palmeri, Mark L

2013-01-01

301

The Comparative Evaluation of the Effects of Tongue Cleaning on Existing Plaque Levels in Children  

PubMed Central

ABSTRACT The present study compared and evaluated the effects of tongue scraping and tongue brushing on existing plaque levels in children. The investigation was a single blind, stratified comparison of three parallel groups of children who performed either tongue scraping or tongue brushing along with tooth brushing or only tooth brushing twice daily under professional supervision for a 21 day period. Dental plaque was recorded using the plaque index described by Silness and Loe at baseline, on day 10 and on day 21. All data was subjected to statistical analysis using Wilcoxon's Signed Ranks Sum Test and Mann-Whitney U-test. The results of the present study show that the tongue scraping and tongue brushing groups showed statistically significant reductions in plaque levels after 10 days and also after 21 days. It was also noted that both tongue scraping and tongue brushing were equally effective in reducing the plaque load in children. How to cite this article: Winnier JJ, Rupesh S, Nayak UA, Reddy V, Rao AP. The Comparative Evaluation of the Effects of Tongue Cleaning on Existing Plaque Levels in Children. Int J Clin Pediatr Dent 2013;6(3):188-192.

Winnier, J Jasmin; Nayak, Ullal Anand; Reddy, Venugopal; Prasad Rao, Arun

2013-01-01

302

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

NASA Astrophysics Data System (ADS)

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. ?CT 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.

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

2014-09-01

303

Relation of osteoprotegerin to coronary calcium and aortic plaque (from the Dallas Heart Study).  

PubMed

Circulating osteoprotegerin (OPG) has been shown to be elevated in patients with vascular disease. The role of OPG as a biomarker for atherosclerosis in a large, unselected population is not well known. Plasma OPG levels were measured in 3,386 subjects in the Dallas Heart Study, a multiethnic, population-based probability sample of adults aged 30 to 65 years. Coronary artery calcium (CAC) was measured by electron beam computed tomography. Aortic plaque was assessed by magnetic resonance imaging. Multivariable logistic regression was used to assess associations among OPG, cardiovascular risk factors, CAC, and aortic plaque. Age, female gender, black race, smoking, personal and family history of coronary artery disease (CAD), diabetes mellitus, hyperlipidemia, CAC, and aortic plaque were significantly associated with higher plasma OPG levels (p <0.01) in univariable analyses. The prevalence of CAC and aortic plaque increased across OPG quartiles (p <0.001 for each). An OPG level in the fourth quartile was independently associated with CAC (RR 1.39, 95% confidence interval 1.01 to 1.93) and aortic plaque (RR 1.42, 95% confidence interval 1.09 to 1.86) after adjustment for age, gender, smoking, diabetes, hyperlipidemia, and family history of premature CAD. In conclusion, plasma OPG is independently associated with CAC and aortic plaque in an unselected population, suggesting it may be a novel biomarker for atherosclerosis in humans. PMID:17293196

Abedin, Moeen; Omland, Torbjørn; Ueland, Thor; Khera, Amit; Aukrust, Pål; Murphy, Sabina A; Jain, Tulika; Gruntmanis, Ugis; McGuire, Darren K; de Lemos, James A

2007-02-15

304

Relationship between Ultrasonic Attenuation, Size and Axial Strain Parameters for ex-vivo Atherosclerotic Carotid Plaque  

PubMed Central

Many ultrasonic parameters, primarily related to attenuation and scatterer size, have been used to characterize the composition of atherosclerotic plaque tissue. In this study we combine elastographic (axial strain ratio) and ultrasonic tissue characterization parameters, namely the attenuation coefficient and a scattering parameter associated with an “equivalent” scatterer size to delineate between fibrous, calcified, and lipidic plaque tissue. We present results obtained from 44 ex-vivo atherosclerotic plaque specimens obtained after carotid endarterectomy on human patients. Our results in the frequency range 2.5~7.5MHz indicate that softer plaques (with higher values of the strain ratio) are usually associated with larger equivalent scatterer size estimates (200 ~500 µm) and lower values of the attenuation coefficient slope (<1 dB/cm/MHz). On the other hand, stiffer plaques (with lower strain ratio values) are associated with smaller equivalent scatterer size estimates (100 ~200 µm) and higher values of the attenuation coefficient slope (1~3 dB/cm/MHz). These results indicate that ultrasonic tissue characterization and strain parameters have the potential to differentiate between different plaque types. These parameters can also be estimated from radiofrequency data acquired under in-vivo conditions and may help the clinician decide on appropriate interventional techniques. PMID:18490099

Shi, Hairong; Varghese, T.; Dempsey, R.J.; Salamat, M.S.; Zagzebski, J.A.

2008-01-01

305

{sup 106}Ruthenium Plaque Therapy (RPT) for Retinoblastoma  

SciTech Connect

Purpose: To evaluate the effectiveness of episcleral {sup 106}ruthenium plaque therapy (RPT) in the management of retinoblastoma. Methods and Materials: One hundred one RPTs were retrospectively analyzed that were performed in 90 eyes of 85 patients with retinoblastoma at National Cancer Center Hospital between 1998 and 2008. Each RPT had a corresponding tumor and 101 tumors were considered in the analysis of local control. Median follow-up length was 72.8 months. Median patient age at the RPT was 28 months. Median prescribed doses at reference depth and outer surface of the sclera were 47.4 Gy and 162.3 Gy, respectively. Results: Local control rate (LCR) and ocular retention rate (ORR) at 2 years were 33.7% and 58.7%, respectively. Unilateral disease, International Classification of Retinoblastoma group C or more advanced at the first presentation or at the time of RPT, vitreous and/or subretinal seeding, tumor size greater than 5 disc diameter (DD), reference depth greater than 5 mm, dose rate at reference depth lower than 0.7 Gy/hour, dose at the reference depth lower than 35 Gy, and (biologically effective dose with an {alpha}/{beta} ratio of 10 Gy) at the reference depth lower than 40 Gy{sub 10} were associated with unfavorable LCR. Two patients died of metastatic disease. Radiation complications included retinal detachment in 12 eyes (13.3%), proliferative retinopathy in 6 (6.7%), rubeosis iris in 2 (2.2%), and posterior subcapsular cataract in 23 (25.6%). Conclusion: RPT is an effective eye-preserving treatment for retinoblastoma.

Murakami, Naoya, E-mail: namuraka@ncc.go.jp [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Suzuki, Shigenobu [Department of Ophthalmic Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Ophthalmic Oncology, National Cancer Center Hospital, Tokyo (Japan); Ito, Yoshinori [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Yoshimura, Ryoichi [Department of Diagnostic Radiology and Oncology, Head and Neck Reconstruction Division, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan)] [Department of Diagnostic Radiology and Oncology, Head and Neck Reconstruction Division, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Inaba, Koji; Kuroda, Yuki; Morota, Madoka; Mayahara, Hiroshi; Sakudo, Mototake; Wakita, Akihisa; Okamoto, Hiroyuki; Sumi, Minako; Kagami, Yoshikazu [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Nakagawa, Keiichi; Ohtomo, Kuni [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan)] [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan); Itami, Jun [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)

2012-09-01

306

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

NASA Astrophysics Data System (ADS)

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 Hotelling observer (CHO) signal-to-noise ratio (SNR) was used to quantify plaque detectability. CHO-SNR improvement ranged from 105% to 128% for fat-MR-based motion correction as compared to no motion correction. Likewise, CHO-SNR improvement ranged from 348% to 396% as compared to both cardiac and dual cardiac-respiratory gating approaches. Based on this study, our approach, a fat-MR based motion correction for coronary plaque PET imaging using simultaneous PET-MR, offers great potential for clinical practice. The ultimate performance and limitation of our approach, however, must be fully evaluated in patient studies.

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

2014-03-01

307

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

PubMed

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 Hotelling observer (CHO) signal-to-noise ratio (SNR) was used to quantify plaque detectability. CHO-SNR improvement ranged from 105% to 128% for fat-MR-based motion correction as compared to no motion correction. Likewise, CHO-SNR improvement ranged from 348% to 396% as compared to both cardiac and dual cardiac-respiratory gating approaches. Based on this study, our approach, a fat-MR based motion correction for coronary plaque PET imaging using simultaneous PET-MR, offers great potential for clinical practice. The ultimate performance and limitation of our approach, however, must be fully evaluated in patient studies. PMID:24556608

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

2014-03-01

308

Butyrylcholinesterase is Associated with ?-Amyloid Plaques in the Transgenic APPSWE/PSEN1dE9 Mouse Model of Alzheimer Disease  

PubMed Central

Histochemical analysis of Alzheimer disease (AD) brain tissues indicates that butyrylcholinesterase (BuChE) is present in ?-amyloid (A?) plaques. The role of BuChE in AD pathology is unknown but an animal model developing similar BuChE-associated A? plaques could provide insights. The APPSWE/PSEN1dE9 mouse (ADTg), which develops A? plaques, was examined to determine if BuChE associates with these plaques, as in AD. We found that in mature ADTg mice, BuChE activity associated with A? plaques. A?-, thioflavin-S- and BuChE-positive plaques mainly accumulated in olfactory structures, cerebral cortex, hippocampal formation, amygdala and cerebellum. No plaques were stained for acetylcholinesterase activity. The distribution and abundance of plaque staining in ADTg closely resembled many aspects of plaque staining in AD. BuChE staining consistently showed fewer plaques than were detected with A? immunostaining but a greater number of plaques than were visualized with thioflavin-S. Double-labelling experiments demonstrated that all BuChE-positive plaques were A?-positive while only some BuChE-positive plaques were thioflavin-S-positive. These observations suggest that BuChE is associated with a subpopulation of A? plaques and may play a role in AD plaque maturation. Further study of this animal model could clarify the role of BuChE in AD pathology. PMID:22157615

Darvesh, Sultan; Cash, Meghan K.; Reid, G. Andrew; Martin, Earl; Mitnitski, Arnold; Geula, Changiz

2011-01-01

309

Data Mining of Atherosclerotic Plaque Transcriptomes Predicts STAT1-Dependent Inflammatory Signal Integration in Vascular Disease  

PubMed Central

Atherosclerotic plaque development involves multiple extra- and intra-cellular signals engaging cells from the immune system and from the vasculature. Pro-inflammatory pathways activated by interferon gamma (IFN?) and toll-like receptor 4 (TLR4) ligands are profoundly involved in plaque formation and have been shown to involve cross-talk in all atheroma-interacting cell types leading to increased activation of signal transducer and activator of transcription-1 (STAT1) and elevated expression of pro-inflammatory mediators. Here we demonstrate that in Gene Expression Omnibus repository (GEO) deposited microarray datasets, obtained from human coronary and carotid atherosclerotic plaques, a significant increase in expression of pro-inflammatory and immunomodulatory genes can be detected. Moreover, increased expression of multiple chemokines, adhesion molecules and matrix-remodeling molecules was commonly detected in both plaque types and correlated with the presence of putative STAT1 binding sites in their promoters, suggesting strong involvement of STAT1 in plaque development. We also provide evidence to suggest that STAT1-nuclear factor kappa-light-chain-enhancer of activated B cells (NF?B) or STAT1-interferon-regulated factor (IRF) regulatory modules are over-represented in the promoters of these inflammatory genes, which points to a possible contribution of IFN? and TLR4 cross-talk in the process of atherogenesis. Finally, a subset of these genes encodes for secreted proteins that could serve as a basis of a non-invasive diagnostic assay. The results of our in silico analysis in vitro provide potential evidence that STAT1-dependent IFN?-TLR4 cross-talk plays a crucial role in coronary and carotid artery plaque development and identifies a STAT1-dependent gene signature that could represent a novel diagnostic tool to monitor and diagnose plaque progression in human atherosclerosis. PMID:25196434

Sikorski, Krzysztof; Wesoly, Joanna; Bluyssen, Hans A. R.

2014-01-01

310

Plaque characteristics and arterial remodeling in coronary and peripheral arterial systems  

PubMed Central

Background Few studies have examined plaque characteristics among multiple arterial beds in vivo. The purpose of this study was to compare the plaque morphology and arterial remodeling between coronary and peripheral arteries using gray-scale and radiofrequency intravascular ultrasound (IVUS) at clinical presentation. Methods and Results IVUS imaging was performed in 68 patients with coronary and 93 with peripheral artery lesions (29 carotid, 50 renal, and 14 iliac arteries). Plaques were classified as fibroatheroma (VH-FA) (further subclassified as thin-capped [VH-TCFA] and thick-capped [VH-ThCFA]), fibrocalcific plaque (VH-FC) and pathological intimal thickening (VH-PIT). Plaque rupture (13% of coronary, 7% of carotid, 6% of renal, and 7% of iliac arteries; P=NS) and VHTCFA (37% of coronary, 24% of carotid, 16% of renal, and 7% of iliac arteries; p=0.02) were observed in all arteries. Compared with coronary arteries, VH-FA was less frequently observed in renal (p<0.001) and iliac arteries (p<0.006). Lesions with positive remodeling demonstrated more characteristics of VH-FA in coronary (84% vs. 25%, p<0.001), carotid (72% vs. 20%, p=0.001), and renal arteries (42% vs. 4%, p=0.001) compared with those with intermediate/negative remodeling. There was positive relationship between RI and percent necrotic area in all four arteries. Conclusions Atherosclerotic plaque phenotypes were heterogeneous among four different arteries; renal and iliac arteries had more stable phenotypes compared with coronary artery. In contrast, the associations of remodeling pattern with plaque phenotype and composition were similar among the various arterial beds. PMID:22721702

Matsuo, Yoshiki; Takumi, Takuro; Mathew, Verghese; Chung, Woo-Young; Barsness, Gregory W.; Rihal, Charanjit S.; Gulati, Rajiv; McCue, Eric T.; Holmes, David R; Eeckhout, Eric; Lennon, Ryan J.; Lerman, Lilach O.; Lerman, Amir

2012-01-01

311

Videodensitometric analysis of advanced carotid plaque: correlation with MMP-9 and TIMP-1 expression  

PubMed Central

Background Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of MMP (TIMP) promote derangement of the extracellular matrix, which is ultimately reflected in plaque images seen on ultrasound. Videodensitometry can identify structural disturbances in plaques. Objectives To establish the correlations between values determined using videodensitometry in B-mode ultrasound images of advanced carotid plaques and the total expression of MMP-9 and TIMP-1 in these removed plaques. Methods Thirty patients underwent ultrasonic tissue characterization of carotid plaques before surgery, using mean gray level (MGL), energy, entropy and homogeneity. Each patient was assigned preoperatively to one of 2 groups: group I, symptomatic patients (n = 16; 12 males; mean age 66.7 ± 6.8 years), and group II, asymptomatic patients (n = 14; 8 males; mean age 67.6 ± 6.81 years). Tissue specimens were analyzed for MMP-9 and TIMP-1 expression. Nine carotid arteries were used as normal tissue controls. Results MMP-9 expression levels were elevated in group II and in normal tissues compared to group I (p < 0.001). TIMP-1 levels were higher in group II than in group I, and significantly higher in normal tissues than in group I (p = 0.039). The MGL was higher in group II compared to group I (p = 0.038). Energy had greater values in group II compared to group I (p = 0.02). There were no differences between patient groups in homogeneity and entropy. Energy positively correlated with MMP-9 and TIMP-1 expression (p = 0.012 and p = 0.031 respectively). Homogeneity positively correlated with MMP-9 and TIMP-1 expression (p = 0.034 and p = 0.047 respectively). There were no correlations between protein expression and MGL or entropy. Conclusions Videodensitometric computer analysis of ultrasound scanning images can be used to identify stable carotid plaques, which have higher total expression levels of MMP-9 and TIMP-1 than unstable plaques. PMID:21923935

2011-01-01

312

Computerized detection of non-calcified plaques in coronary CT angiography: topological soft-gradient detection method for plaque prescreening  

NASA Astrophysics Data System (ADS)

Non-calcified plaque (NCP) detection in coronary CT angiography (cCTA) is challenging due to the low CT number of NCP, the large number of coronary arteries and multiple phase CT acquisition. We are developing computervision methods for automated detection of NCPs in cCTA. A data set of 62 cCTA scans with 87 NCPs was collected retrospectively from patient files. Multiscale coronary vessel enhancement and rolling balloon tracking were first applied to each cCTA volume to extract the coronary artery trees. Each extracted vessel was reformatted to a straightened volume composed of cCTA slices perpendicular to the vessel centerline. A new topological soft-gradient (TSG) detection method was developed to prescreen for both positive and negative remodeling candidates by analyzing the 2D topological features of the radial gradient field surface along the vessel wall. Nineteen features were designed to describe the relative location along the coronary artery, shape, distribution of CT values, and radial gradients of each NCP candidate. With a machine learning algorithm and a two-loop leave-one-case-out training and testing resampling method, useful features were selected and combined into an NCP likelihood measure to differentiate TPs from FPs. The detection performance was evaluated by FROC analysis. Our TSG method achieved a sensitivity of 96.6% with 35.4 FPs/scan at prescreening. Classification with the NCP likelihood measure reduced the FP rates to 13.1, 10.0 and 6.7 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. These results demonstrated that the new TSG method is useful for computerized detection of NCPs in cCTA.

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

2013-03-01

313

Risk of thrombosis in human atherosclerotic plaques: role of extracellular lipid, macrophage, and smooth muscle cell content  

Microsoft Academic Search

OBJECTIVE--To assess the size of the lipid pool and the number of smooth muscle cells and monocyte\\/macrophages in human aortic plaques that were intact and to compare the results with those in aortic plaques undergoing ulceration and thrombosis. DESIGN--The lipid pool was measured as a percentage of the total cross sectional area of the plaque. Immunohistochemistry was used to identify

M J Davies; P D Richardson; N Woolf; D R Katz; J Mann

1993-01-01

314

Site-specific intravascular ultrasound analysis of remodelling index and calcified necrosis patterns reveals novel blueprints for coronary plaque instability  

PubMed Central

Aims Post-mortem pathological studies have shown that a “vulnerable” plaque is the dominant patho-physiological mechanism responsible for acute coronary syndromes (ACS). One way to improve our understanding of these plaques in vivo is by using histological “surrogates” created by intravascular ultrasound derived virtual histology (IVUS-VH). Our aim in this analysis was to determine the relationship between site-specific differences in individual plaque areas between ACS plaques and stable plaques (SP), with a focus on remodelling index and the pattern of calcifying necrosis. Methods and results IVUS-VH was performed before percutaneous intervention in both ACS culprit plaques (CP) n=70 and stable disease (SP) n=35. A total of 210 plaque sites were examined in 105 lesions at the minimum lumen area (MLA) and the maximum necrotic core site (MAX NC). Each plaque site had multiple measurements made including some novel calculations to ascertain the plaque calcification equipoise (PCE) and the calcified interface area (CIA). CP has greater amounts of positive remodelling at the MLA (RI@MLA): 1.1 (±0.17) vs. 0.95 (±0.14) (P<0.001); lower values for PCE 30% vs. 54% (P<0.001) but a higher CIA 5.38 (±2.72) vs. 3.58 (±2.26) (P=0.001). These features can provide discriminatory ability between plaque types with area under the curve (AUC) measurements between 0.65-0.86. The cut-off values with greatest sensitivity and specificity to discriminate CP morphologies were: RI @ MLA >1.12; RI @ MAX NC >1.22; PCE @ MLA <47.1%; PCE @MAX NC <47.3%; CIA @ MLA >2.6; CIA @ MAX NC >3.1. Conclusions Determining the stage of calcifying necrosis, along with the remodelling index can discriminate between stable and ACS related plaques. These findings could be applied in the future to help detect plaques that have a vulnerable phenotype.

Patel, Billal; Stables, Rodney H.; Perry, Raphael A.; Palmer, Nicholas D.

2014-01-01

315

Morphologically distinct plaque types differentially affect dendritic structure and organisation in the early and late stages of Alzheimer's disease  

Microsoft Academic Search

We have investigated the effects of the deposition of insoluble #-amyloid plaques on dendritic morphology within the neocortex. Labelling for #-amyloid identified three morphologically distinct plaque types present both within the brains of preclinical Alzheimer's disease (AD) and end-stage AD cases. In both preclinical and end-stage AD, the percentage area occupied by diffuse plaques contained a greater density of labelling

Paul A. Adlard; James C. Vickers

2002-01-01

316

Compositions for labeling .beta.-amyloid plaques and neurofibrillary tangles  

DOEpatents

Compositions useful for labeling .beta.-amyloid plaques and neurofibrillary tangles are provided. The compositions comprises compounds of formula (I): ##STR00001## wherein R.sub.1 is selected from the group consisting of --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C.dbd.C(CN).sub.2-alkyl, --C.dbd.C(CN).sub.2-alkylenyl-R.sub.4, ##STR00002## wherein R.sub.4 is a radical selected from the group consisting of alkyl, substituted alkyl, aryl and substituted aryl; R.sub.5 is a radical selected from the group consisting of --NH.sub.2, --OH, --SH, --NH-alkyl, --NHR.sub.4, --NH-alkylenyl-R.sub.4, --O-alkyl, --O-alkylenyl-R.sub.4, --S-alkyl, and --S-alkylenyl-R.sub.4; R.sub.6 is a radical selected from the group consisting of --CN, --COOH, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)-halogen, --C(O)NH-alkyl, --C(O)NH-alkylenyl-R.sub.4 and --C(O)NH.sub.2; R.sub.7 is a radical selected from the group consisting of O, NH, and S; and R.sub.8 is N, O or S; and R.sub.2 is selected from the group consisting of alkyl and alkylenyl-R.sub.10 and R.sub.3 is alkylenyl-R.sub.10, wherein R.sub.10 is selected from the group consisting of --OH, --OTs, halogen, spiperone, spiperone ketal, and spiperone-3-yl, or R.sub.2 and R.sub.3 together form a heterocyclic ring, optionally substituted with at least one radical selected from the group consisting of alkyl, alkoxy, OH, OTs, halogen, alkyl-R.sub.10, carbonyl, spiperone, spiperone ketal and spiperone-3-yl, and further wherein one or more of the hydrogen, halogen or carbon atoms are optionally replaced with a radiolabel.

Barrio, Jorge R. (Agoura Hills, CA); Petric, Andrej (Ljubljana, SI); Satyamurthy, Nagichettiar (Los Angeles, CA); Small, Gary W. (Los Angeles, CA); Cole, Gregory M. (Santa Monica, CA); Huang, Sung-Cheng (Sherman Oaks, CA)

2008-03-11

317

Methods for labeling .beta.-amyloid plaques and neurofibrillary tangles  

DOEpatents

A method for labeling .beta.-amyloid plaques and neurofibrillary tangles in vivo and in vitro, comprises contacting a compound of formula (I): ##STR1## with mammalian tissue. In formula (I), R.sub.1 is selected from the group consisting of --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C.dbd.C(CN).sub.2 -alkyl, --C.dbd.C(CN).sub.2 -alkylenyl-R.sub.4 , ##STR2## R.sub.4 is a radical selected from the group consisting of alkyl, substituted alkyl, aryl and substituted aryl; R.sub.5, is a radical selected from the group consisting of --NH.sub.2, --OH, --SH, --NH-alkyl, --NHR.sub.4, --NH-alkylenyl-R.sub.4, --O-alkyl, --O-alkylenyl-R.sub.4, --S-alkyl, and --S-alkylenyl-R.sub.4 ; R.sub.6 is a radical selected from the group consisting of --CN, --COOH, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)-halogen, --C(O)NH , --C(O)NH-alkyl, --C(O)NH-alkylenyl-R.sub.4 ; R.sub.7 is a radical selected from the group consisting of O, NH, and S; and R.sub.8 is N, O or S. R.sub.2 and R.sub.3 are each independently selected from the group consisting of alkyl and alkylenyl-R.sub.10, wherein R.sub.10 is selected from the group consisting of --OH, --OTs, halogen, spiperone, spiperone ketal and spiperone-3-yl. Alternatively, R.sub.2 and R.sub.3 together form a heterocyclic ring, optionally substituted with at least one radical selected from the group consisting of alkyl, alkoxy, OH, OTs, halogen, alkylenyl-R.sub.10, carbonyl, spiperone, spiperone ketal and spiperone-3-yl. In the compounds of formula (I), one or more of the hydrogen, halogen or carbon atoms can, optionally, be replaced with a radiolabel.

Barrio, Jorge R. (Agoura Hills, CA); Petric, Andrej (Ljubljana, SI); Satyamurthy, Nagichettiar (Los Angeles, CA); Small, Gary W. (Los Angeles, CA); Cole, Gregory M. (Santa Monica, CA); Huang, Sung-Cheng (Sherman Oaks, CA)

2001-01-01

318

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

NASA Astrophysics Data System (ADS)

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 precise lesion formation in the presence or arterial pulsation and tissue motion. In this paper, we show results from targeting both proximal and distal sides of the vessel wall with a series of 5 - 7 discrete shots in each plane (typically three planes per plaque). Experiments to demonstrate a full treatment forming contiguous lesion within the target plaque are currently underway.

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

2012-11-01

319

Alzheimer's amyloid precursor protein-positive degenerative neurites exist even within kuru plaques not specific to Alzheimer's disease.  

PubMed Central

To clarify the relationship between amyloid formation and amyloid precursor protein (APP), the brain sections from eight patients with Alzheimer's disease (AD) and four with Gerstmann-Sträussler Syndrome (GSS) were investigated immunohistochemically by the double-immunostaining method. In AD, most APP-positive senile plaques belong to classical plaques or primitive plaques, whereas in diffuse plaques, APP-positive neuritic components are rarely observed. The authors documented that anti-APP-labeled degenerative neurites surrounding kuru plaques in all four GSS patients. These kuru plaques were verified by double immunostaining using anti-prion protein and anti-APP. The APP-positive structures in kuru plaques were almost identical with those seen in the classical plaques in AD. The authors concluded that APP-positive degenerative neurites are not an early event in the amyloid formation of senile plaques. It is therefore postulated that depositions of beta/A4 and prion proteins are primary events that may involve the surrounding microenvironment and result in the secondary formation of APP-positive degenerative neurites, not specific to AD. Images Figure 1 Figure 2 Figure 3 PMID:1684265

Ohgami, T.; Kitamoto, T.; Weidmann, A.; Beyreuther, K.; Tateishi, J.

1991-01-01

320

Concentration- and time-response characteristics of plaque isolates of Agrotis ipsilon multiple nucleopolyhedrovirus derived from a field isolate.  

PubMed

Plaque isolates derived from the Illinois field isolate of Agrotis ipsilon multiple nucleopolyhedrovirus are distinguished by the presence or absence of a small deletion in the baculovirus egt (ecdysteroid UDP-glucosyltransferase) coding sequence. In concentration-response and time-response bioassays with both plaque and field isolates, plaque isolates with a mutated egt gene were less pathogenic against A. ipsilon larvae than other isolates, but killed larvae faster. Mixed infections with isolates representing the two different egt genotypes caused the same level of mortality as the field isolate and a plaque isolate with a wild-type egt gene. PMID:23220242

Harrison, Robert L

2013-02-01

321

Effects of a chewable sodium bicarbonate oral composition on plaque and gingivitis.  

PubMed

The purpose of this pilot study was to evaluate the effects of an effervescent sodium bicarbonate based oral composition on plaque and gingivitis. Subjects selected for this study presented at screening with moderate plaque and American Academy of Periodontology (AAP) Type I/II periodontal status. At baseline, subjects were allocated to one of two groups by simple randomization; placebo (n=16) and active (n=16). During the study two subjects withdrew due to non-compliance and one because of a death in the family. Data were collected at baseline, day 14, and day 28. The Plaque Index (PI) of Silness and Loe was used to quantify the amount of supragingival plaque surrounding six selected teeth (3,14,8,19,24,30), and the Gingival Index (GI) of Loe and Silness was used to assess bleeding tendencies and visual appearance on the same six teeth. A soft tissue oral assessment was completed at each visit. Subjects were asked to perform study treatment three times a day, after meals, and continue with normal oral hygiene procedures. Subjects were requested to complete a 28-day diary to assess compliance. Data were analyzed using repeated measures analysis of variance. There were no statistically significant differences between the placebo and the active product groups and no statistical significant interaction between product and location within the mouth or visit for either the plaque or gingival scores. Results reveal the product was safe to oral tissues and was well accepted by subjects. PMID:12167942

McCombs, G B; Green, M L; Root, J

2001-02-15

322

Comprehensive overview of definitions for optical coherence tomography-based plaque and stent analyses.  

PubMed

Optical coherence tomography (OCT) is the current state-of-the-art intracoronary imaging modality that allows visualization of detailed morphological characteristics of both atherosclerotic plaque and stent. So far, three expert review documents have been released for standardization of OCT image analysis. In the real world, a variety of definitions are being used by different groups and by different core laboratories to analyze OCT findings because of different clinical/procedural contexts in which OCT research has been carried out. This comprehensive overview is aimed to summarize different applicable definitions used by different research groups in plaque and stent analysis using OCT. In addition, it presents readers with a panoramic view to select the best definition of OCT measurement for one's own study purpose. We divided this review article into two parts: Part I - Plaque analysis, and Part II - Stent analysis. The plaque analysis section summarizes the definitions of plaque composition, rupture, erosion, protruding calcific nodules, macrophages, microvessels, and cholesterol crystal. The stent analysis section includes the classification of stent struts, features of neointimal hyperplasia, and other stent-related findings such as tissue protrusion, thrombus, intrastent, and stent edge dissections. In each case of controversy, an explanation for the specific context is provided. PMID:24356250

Di Vito, Luca; Yoon, Joo Heung; Kato, Koji; Yonetsu, Taishi; Vergallo, Rocco; Costa, Marco; Bezerra, Hiram G; Arbustini, Eloisa; Narula, Jagat; Crea, Filippo; Prati, Francesco; Jang, Ik-Kyung

2014-03-01

323

A comparison of chlorhexidine, cetylpyridinium chloride, triclosan, and C31G mouthrinse products for plaque inhibition.  

PubMed

There are a large number of mouthrinse products available to the general public for use as adjuncts to oral hygiene. Many have not been evaluated and relatively few comparisons of products have been made. This study compared 4 mouthrinse products containing cetylpyridinium chloride (CPC), chlorhexidine, C31G, or triclosan with saline rinse included as a placebo control. Twenty dentate volunteers took part in this 4-day plaque regrowth study which had a single blind, randomized cross-over design balanced for residual effects. On day 1 of each study period, volunteers were rendered plaque free by a professional prophylaxis, suspended normal oral hygiene measures, and rinsed twice daily for 1 minute with 15 mL of the allocated rinse. On day 5, subjects were scored for disclosed plaque by plaque index and plaque area. By both measures the order of decreasing product efficacy was chlorhexidine, CPC and triclosan, C31G, and saline. All the differences in favor of the chlorhexidine product were highly significant as were those in favor of the other rinses compared to saline. It is concluded that the findings of this study reflect the actual chemical benefits of the products divorced from the indeterminate variable of toothbrushing. PMID:8724706

Renton-Harper, P; Addy, M; Moran, J; Doherty, F M; Newcombe, R G

1996-05-01

324

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

PubMed

The information contained within multicontrast magnetic resonance images (MRI) promises to improve tissue classification accuracy, once appropriately analyzed. Predictive models capture relationships empirically, from known outcomes thereby combining pattern classification with experience. In this study, we examine the applicability of predictive modeling for atherosclerotic plaque component classification of multicontrast ex vivo MR images using stained, histopathological sections as ground truth. Ten multicontrast images from seven human coronary artery specimens were obtained on a 9.4 T imaging system using multicontrast-weighted fast spin-echo (T1-, proton density-, and T2-weighted) imaging with 39-mum isotropic voxel size. Following initial data transformations, predictive modeling focused on automating the identification of specimen's plaque, lipid, and media. The outputs of these three models were used to calculate statistics such as total plaque burden and the ratio of hard plaque (fibrous tissue) to lipid. Both logistic regression and an artificial neural network model (Relevant Input Processor Network-RIPNet) were used for predictive modeling. When compared against segmentation resulting from cluster analysis, the RIPNet models performed between 25 and 30% better in absolute terms. This translates to a 50% higher true positive rate over given levels of false positives. This work indicates that it is feasible to build an automated system of plaque detection using MRI and data mining. PMID:17254700

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

2007-01-01

325

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

NASA Astrophysics Data System (ADS)

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.

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

1997-05-01

326

Spectral correlation analysis of amyloid ? plaque inhomogeneity from double staining experiments.  

PubMed

A spectral correlation algorithm for the analysis of hyperspectral fluorescence images is proposed by Ellingsen et al. [J. Biomed. Opt. 18, 020501 (2013)]. Here, it is applied to the analysis of double-stained A? amyloid plaques being related to the Alzheimer's disease (AD). Sections of APP/PS1 AD mice model brains are double stained with luminescent-conjugated oligothiophenes, known to bind to amyloid protein deposits. Hyperspectral fluorescence images of the brain sections are recorded and by applying the correlation algorithm the spectral inhomogeneity of the double-stained samples is mapped in terms of radial distribution and spectral content. To further investigate the progression of A? amyloid plaque formation, 19 AD mice of different ages up to 23 months are characterized, enabling a statistical analysis of the plaque heterogeneity. In accordance with recent findings by Nyström et al. [ACS Chem. Biol. 8, 1128-1133 (2013)], the spectral distribution within A? plaques is found to vary with age throughout the lifespan of the mouse. With the new correlation algorithm, it is possible to quantify the spectral abundance of the two stains depending on the relative distance from the plaque center and mouse age. Thus, we demonstrate the use of the correlation analysis approach in double-staining experiments and how it is possible to relate these to structural/spectral changes in biological samples. PMID:23933966

Ellingsen, Pål Gunnar; Nyström, Sofie; Reitan, Nina Kristine; Lindgren, Mikael

2013-10-01

327

A statin-loaded reconstituted high-density lipoprotein nanoparticle inhibits atherosclerotic plaque inflammation  

NASA Astrophysics Data System (ADS)

Inflammation is a key feature of atherosclerosis and a target for therapy. Statins have potent anti-inflammatory properties but these cannot be fully exploited with oral statin therapy due to low systemic bioavailability. Here we present an injectable reconstituted high-density lipoprotein (rHDL) nanoparticle carrier vehicle that delivers statins to atherosclerotic plaques. We demonstrate the anti-inflammatory effect of statin-rHDL in vitro and show that this effect is mediated through the inhibition of the mevalonate pathway. We also apply statin-rHDL nanoparticles in vivo in an apolipoprotein E-knockout mouse model of atherosclerosis and show that they accumulate in atherosclerotic lesions in which they directly affect plaque macrophages. Finally, we demonstrate that a 3-month low-dose statin-rHDL treatment regimen inhibits plaque inflammation progression, while a 1-week high-dose regimen markedly decreases inflammation in advanced atherosclerotic plaques. Statin-rHDL represents a novel potent atherosclerosis nanotherapy that directly affects plaque inflammation.

Duivenvoorden, Raphaël; Tang, Jun; Cormode, David P.; Mieszawska, Aneta J.; Izquierdo-Garcia, David; Ozcan, Canturk; Otten, Maarten J.; Zaidi, Neeha; Lobatto, Mark E.; van Rijs, Sarian M.; Priem, Bram; Kuan, Emma L.; Martel, Catherine; Hewing, Bernd; Sager, Hendrik; Nahrendorf, Matthias; Randolph, Gwendalyn J.; Stroes, Erik S. G.; Fuster, Valentin; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

2014-01-01

328

Carotid atherosclerotic plaques: proteomics study after a low-abundance protein enrichment step.  

PubMed

Atherosclerosis is one of the most important causes of cardiovascular and cerebrovascular events. Although phenotypic differentiation between stable and unstable plaques is currently possible, proteomic analysis of the atherosclerotic plaque could offer a global view of the atherosclerosis pathology. With the objective to highlight the detection of low-abundance proteins, we reduced the dynamic range of proteins by combinatorial peptide ligand library treatment of human carotid artery atherosclerotic plaques. After enrichment step, abundance of major proteins was decreased, revealing different protein profiles as assessed by both SDS-polyacrylamide gel electrophoresis and two-dimensional electrophoresis comparative analyses. Identification of proteins that were contained in a spot allowed finding large differences between noncomplicated and complicated plaques from carotid atherosclerotic lesions. Novel low-abundance proteins were detected correlating very well with biological alterations related to atherosclerosis (heat shock protein 27 (HSP27) isoforms, aldehyde dehydrogenase, moesin, Protein kinase C delta-binding protein, and inter-? trypsin inhibitor family heavy chain-related protein (ITIH4)). At the same time, the differential expression of known proteins of interest such as hemoglobin ?-chain and heat shock protein 27 between noncomplicated and hemorrhagic complicated plaques was maintained after enrichment step. The detection of different isoforms of a low-abundance protein such as heat shock protein 27 species was actually improved after enrichment of tissue protein extracts. All of these findings clearly support further investigations in view to confirm the role of these proteins as possible biomarkers. PMID:22287176

Malaud, Eric; Piquer, Dominique; Merle, Delphine; Molina, Laurence; Guerrier, Luc; Boschetti, Egisto; Saussine, Max; Marty-Ané, Charles; Albat, Bernard; Fareh, Jeannette

2012-02-01

329

A Statin-Loaded Reconstituted High-Density Lipoprotein Nanoparticle Inhibits Atherosclerotic Plaque Inflammation  

PubMed Central

Inflammation is a key feature of atherosclerosis and a target for therapy. Statins have potent anti-inflammatory properties but these cannot be fully exploited with oral statin therapy due to low systemic bioavailability. Here we present an injectable reconstituted high-density lipoprotein (rHDL) nanoparticle carrier vehicle that delivers statins to atherosclerotic plaques. We demonstrate the anti-inflammatory effect of statin-rHDL in vitro and show this effect is mediated through inhibition of the mevalonate pathway. We also apply statin-rHDL nanoparticles in vivo in an apolipoprotein E-knockout mouse model of atherosclerosis and show they accumulate in atherosclerotic lesions where they directly affect plaque macrophages. Finally we demonstrate that a three-month low-dose statin-rHDL treatment regimen inhibits plaque inflammation progression, while a one-week high-dose regimen markedly decreases inflammation in advanced atherosclerotic plaques. Statin-rHDL represents a novel potent atherosclerosis nanotherapy that directly affects plaque inflammation. PMID:24445279

Duivenvoorden, Raphael; Tang, Jun; Cormode, David P.; Mieszawska, Aneta J.; Izquierdo-Garcia, David; Ozcan, Canturk; Otten, Maarten J.; Zaidi, Neeha; Lobatto, Mark E.; van Rijs, Sarian M.; Priem, Bram; Kuan, Emma L.; Martel, Catherine; Hewing, Bernd; Sager, Hendrik; Nahrendorf, Matthias; Randolph, Gwendalyn J.; Stroes, Erik S.G.; Fuster, Valentin; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J.M.

2014-01-01

330

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

331

Antibacterial activity of aqueous extracts of Indian chewing sticks on dental plaque: An in vitro study.  

PubMed

The anti-microbial efficacy of aqueous extracts of Indian chewing sticks against different kinds of plaque bacteria in vitro was investigated. Supra-gingival plaque is cultured and subjected to the antibacterial activity of the aqueous extracts of chewing sticks (Neem, Acacia, Pongamia glabra, Achyranthes aspera, Streblus asper) separately. The results of the study demonstrate that all the five chewing sticks under study possess inhibitory potential against bacteria present in dental plaque mainly on aerobes. The antibacterial efficacy of aqueous extracts has antibacterial effects and could be used as a therapeutic agent and therefore, it appears to be potent anti-microbial agents that could be considered as a medicinal plant. Results of this study showed chewing sticks contained antibacterial agents, but the concentration and composition of the active substances differed among the plants. PMID:25210357

Rao, Dola Srinivasa; Penmatsa, Tanuja; Kumar, Alapati Kranthi; Reddy, M Narendra; Gautam, Nalam Sai; Gautam, Nalam Radhika

2014-07-01

332

Environmental Asbestotic Pleural Plaques in Northeast Corsica: Correlations with Airborne and Pleural Mineralogic Analysis  

PubMed Central

We report a prevalence study of environmental pleural plaques in subjects over 50 years old from the northeastern Corsican village of Murato, built on asbestos surface deposits. The percentage of plaques was 41%, versus 7.5% in the control village of Vezzani. Although surface deposits contain both chrysotile and tremolite, airborne pollution and asbestos lung burden of exposed inhabitants consist essentially of tremolite as assessed by transmission electron microscopy (TEM). However, TEM analysis of the parietal pleura of three animals bred in exposed areas showed a predominance of short fibers of chrysotile. The respective roles of tremolite and chrysotile in inducing pleural plaques in Corsica should thus be considered.—Environ Health Perspect 102(Suppl 5):251–252 (1994) PMID:7882944

Rey, F.; Boutin, C.; Viallat, J. R.; Steinbauer, J.; Alessandroni, P.; Jutisz, P.; Di Giambattista, D.; Billon-Galland, M. A.; Hereng, P.; Dumortier, P.; De Vuyst, P.

1994-01-01

333

Diffusion en régime permanent d'un champ magnétique glissant dans une plaque ferromagnétique  

NASA Astrophysics Data System (ADS)

We determine the magnetic vector potential for a ferromagnetic plate in the steady state conditions with eddy currents which are induced by sliding field currents. Our plate has non linear magnetic B(H) characteristic. We deduce the cyclic impedance of the field coils and the visualizations of the induction and the permeability of the plate as a function of both the magnitude of field current and the slip frequency. On détermine en régime permanent le potentiel vecteur magnétique dans une plaque ferromagnétique en présence des courants induits par un champ magnétique d'excitation glissant. La plaque a une caractéristique magnétique B(H) non linéaire. On en déduit en fonction de l'intensité du courant d'excitation et de la fréquence de glissement l'impédance cyclique des bobinages d'excitation ainsi que des visualisations de l'induction et de la perméabilité de la plaque.

Guettafi, A.; Quichaud, G.

1993-08-01

334

Totally extradural spinal en plaque meningiomas - Diagnostic dilemmas and treatment strategies  

PubMed Central

Background: Meningiomas are the second most common intraspinal tumors, constituting ~25% of all intraspinal tumors; however, in the context of extradural spinal lesions, the diagnosis of meningioma is an uncommon one. Purely extradural spinal meningiomas, especially of the en plaque variety, frequently mimic metastatic disease and may result in inadequate therapy. Case Description: We report two cases of totally extradural en-plaque meningiomas of the spine, one each in the cervical and dorsal spine. We present the significant diagnostic dilemmas posed by these cases and discuss the pathogenesis, treatment strategies, and long-term behavior of these uncommon lesions. Conclusion: Attention needs to be drawn to this dangerous preoperative and intraoperative misinterpretation. Intraoperative histopathology support for correct identification, gross total resection at surgery, inclusion of a durotomy to rule out intradural extension, and long-term follow-up are cornerstones for successful management of totally extradural en plaque spinal meningiomas.

Savardekar, Amey; Chatterjee, Debarshi; Chatterjee, Debajyoti; Dhandapani, Sivashanmugam; Mohindra, Sandeep; Salunke, Pravin

2014-01-01

335

Use of PCR to estimate the prevalence of Equus caballus papillomavirus in aural plaques in horses.  

PubMed

Aural plaques occur on the skin of the medial surface of the pinnae of horses. In this study the presence of Equus caballus papillomavirus (EcPV)-3 and -4 DNA was assessed in 45 such plaques using a 'touchdown' PCR. Papillomaviruses (PVs) were detected in 62.3% (28/45) of samples: EcPV-3 and -4 DNA in 8.89% (4/45) and 37.78% (17/45) of samples, respectively, with 15.56% (7/45) of samples exhibiting co-infection. Viral DNA was not detected in 37.78% (17/45) of samples, suggesting the possible existence of other equine PVs. Neither EcPV-3 nor -4 were detected in negative control skin. This study is the first to evaluate the prevalence of these two viruses in equine aural plaques. PMID:23773810

Gorino, Ana Claudia; Oliveira-Filho, Jose P; Taniwaki, Sueli A; Basso, Roberta M; Zakia, Luiza S; Araujo, João P; Borges, Alexandre S

2013-09-01

336

Reduced plaque accumulation on hydrocarbon thin film deposited on restorative acrylic polymers.  

PubMed

The deposition of a thin polymeric film from ethylene plasma was used to modify the surface properties of acrylic teeth, commonly used in the dental practice for crown and bridge restorations. The effects of the surface modification process on the surface composition, morphology, and energetics were evaluated by electron spectroscopy for chemical analysis, atomic force microscopy, and contact angle measurement respectively. Plaque accumulation on the plasma-coated and untreated material was evaluated in in vivo experiments, in which the same patient received conventional and plasma-coated restorations. The hydrocarbon-like surface of the plasma-coated restoration remained remarkably free from plaque, even in the absence of brushing. On the other hand, plaque accumulation was observed on the unmodified restoration. Results are discussed according to recent theories on bioadhesive phenomena. PMID:9261683

Bellanda, M; Cassinelli, C; Morra, M

1997-08-01

337

Diagnosis of infantile myofibromatosis with pseudo-ulcerated plaque using prenatal ultrasound: A case report  

PubMed Central

The present case report describes a case of infantile myofibromatosis (IM) with a pseudo-ulcerated plaque on the right side of the back of a fetus, detected in the 38th week of gestation using prenatal ultrasound. The fetus was examined weekly by ultrasound to measure the size of the mass. At birth, the scarlet mass was slightly elevated compared with the skin around it, with a cavity in the center. It appeared similar to an ulcerated plaque, but the surface of the mass was intact and smooth with a stratum lucidum. Thus, the mass was indicated to be a pseudo-ulcerated plaque. Three months later, the mass had grown larger and so was removed by surgery. The pathology of the mass was confirmed as IM. It is suggested that IM should be considered when a soft tissue tumor is presented by prenatal ultrasound. PMID:25371730

ZHANG, FEIXUE; CHENG, DONGFENG; WU, MEI; GE, LING; MA, XIANGXING

2014-01-01

338

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

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

339

An algorithm of rapid extraction star point and diffuse plaque in star image  

NASA Astrophysics Data System (ADS)

In order to solve the low speed and low accuracy in exacting star point which used in starlight star point navigation, this paper presents an algorithm to quickly extract the coordinates of the Navistar in the image. First of all, this algorithm extracts the coordinates of star point with a low accuracy, then extracting its diffuse plaque, in the final, get its exact coordinates. Which can reduce the amount of computation to improve navigation extraction rate while avoid the time-domain filtering of the star point of the outline and diffuse spots of gray value, solving low speed in the sky diffuse plaques star point image extraction. The experiments show that this algorithm can extract the star point while making dark star and background noise greatly reduced. At the same time, star point and diffuse plaque contour gray value can be consistent with the original image.

Wang, Shuai; Li, Yingchun; Du, Lin; Fan, Youchen

2014-02-01

340

Dental Caries, and Supragingival Plaque and Calculus among Students, Tanga, Tanzania  

PubMed Central

The prevalence of dental caries and supragingival plaque and calculus in 785 secondary schools students was assessed. More than half (53.6%) of the students were caries-free, and the majority of those with dental caries experience were aged 14–17 (68.1%) and females (53%). Mean DMFT was 1.26, with mean D-component of 1.05, and molars were most affected. Most students had supragingival plaque (74%) and calculus (56.9%) and more so in males than females (P > 0.05). Less than half of the students had experience of dental caries and those with caries were mostly females and of the younger age group. The low DMFT was contributed to the D-component, and molars were the tooth type most affected.The majority of students had supra-gingival plaque and calculus and more so in males than females. PMID:22461985

Carneiro, L. C.; Kabulwa, M. N.

2012-01-01

341

Application of imaging-derived parameters to dosimetry of intravascular brachytherapy sources: perturbation effects of residual plaque burden.  

PubMed

The dosimetric effect of geometric and material heterogeneities on intravascular brachytherapy dose delivery has been studied recently. Residual plaque within the coronary vessel appears to have an impact on the uniform delivery of radiation dose to the arterial tissue. In this study, we have examined the effect of residual plaque burden and post-PCI (percutaneous coronary intervention) plaque configuration on the dose to the arterial wall from clinical intravascular brachytherapy beta-emitting sources containing 32P and 90Sr/90Y. Monte Carlo simulations using the MCNP4B code were performed for these catheter-based sources with residual plaque burden ranging between 25% and 50%. The residual plaque burden values were derived from post-PCI data provided in several recent clinical studies. Dose calculations were performed for three different values of plaque density (1.45 g cm(-3), 2.20 g cm(-3), and 3.1 g cm(-3)) and three different plaque morphologies for the same residual plaque burden. The dose perturbation factor (DPF), defined as the ratio of dose at 2 mm radial distance for a given case to the dose at the same radial distance in homogeneous water medium, was determined for each of the three different plaque densities. The range of DPF values was 0.81-1.01, 0.62-0.99, and 0.41-0.97 for different plaque densities for the 32P source. Corresponding DPF values for the 90Sr/90Y source were 0.90-1.01, 0.84-1.01, and 0.62-1.01. The results indicate the need for accurate assessment of post-PCI clinical measurements such as minimal lumen diameter and residual plaque burden and incorporation of these values into dose calculations. PMID:12148741

Sehgal, Varun; Li, Zuofeng; Palta, Jatinder R; Smith, Karen M; Bolch, W E

2002-07-01

342

The acid-tolerant microbiota associated with plaque from initial caries and healthy tooth surfaces.  

PubMed

The intent of this study was to compare the inherent acid tolerance of bacteria in samples of dental plaque from tooth sites in subjects with and without initial caries. Plaque was collected from approximal surfaces showing early enamel caries and from healthy tooth surfaces in the same subjects, as well as from enamel surfaces of caries-free individuals. In addition to plating on blood agar, the plaque samples were plated directly on non-selective solid agar medium buffered to pH 7.0, 6.0, 5.5, 5.0, 4.5 and 4.0 to avoid any loss of adaptation to acid during primary isolation of plaque bacteria. The results showed that approximately 50% of the total cultivable plaque microbiota from caries, as well as healthy tooth sites, was able to grow at pH 5.5 and 1% at pH 5.0, pH values regarded as critical for the demineralization of tooth enamel. At pH 5.0, members of the genus Streptococcus were the dominant group, but mutans streptococci accounted for less than half of the streptococcal viable count. The other acid-tolerant streptococcal isolates included Streptococcus anginosus, Streptococcus constellatus, Streptococcus gordinii, Streptococcus intermedius, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius and SStreptococcus sanguis. Analysis of the results indicated that the mutans streptococci in dental plaque were highly variable with respect to acid tolerance, and that both caries and healthy sites harboured significant numbers of mutans streptococci that were not acid-tolerant. PMID:14571116

Svensäter, G; Borgström, M; Bowden, G H W; Edwardsson, S

2003-01-01

343

Traditional Cardiovascular Risk Factors Explain the Minority of the Variability in Carotid Plaque  

PubMed Central

Background Subclinical atherosclerotic plaque is an important marker of increased vascular risk. Identifying factors underlying the variability in burden of atherosclerotic carotid plaque unexplained by traditional vascular risk factors may help target novel preventive strategies. Methods As a part of the carotid substudy of the Northern Manhattan Study (NOMAS), 1,790 stroke-free individuals (mean age 69±9; 60% women; 61% Hispanic, 19% black, 18% white) were assessed for total plaque area (TPA) burden using 2D carotid ultrasound imaging. Multiple linear regression models were constructed. Model 1 used pre-specified traditional risk factors: age, sex, LDL-cholesterol, diabetes mellitus, pack-years of smoking, blood pressure (BP), and treatment for BP; and Model 2, an addition of socioeconomic and less traditional risk factors. The contributions of the components of the Framingham heart risk score (FRS) and the NOMAS global vascular risk score (GVRS) to the TPA were explored. Results Prevalence of carotid plaque was 58%. Mean TPA was 13±19mm2. Model 1 explained 19.5% of the variance in TPA burden (R2=0.195). Model 2 explained 21.9% of TPA burden. Similarly, FRS explained 18.8% and NOMAS GVRS 21.5% of the TPA variance. Conclusions The variation in preclinical carotid plaque burden is largely unexplained by traditional and less traditional vascular risk factors, suggesting that other unaccounted environmental and genetic factors play an important role in the determination of atherosclerotic plaque. Identification of these factors may lead to new approaches to prevent stroke and cardiovascular disease. PMID:22550054

Kuo, F; Gardener, H; Dong, C; Cabral, D; Della-Morte, D; Blanton, SH; Elkind, MSV; Sacco, RL; Rundek, T

2012-01-01

344

Monte Carlo dosimetry for {sup 125}I and {sup 103}Pd eye plaque brachytherapy  

SciTech Connect

A Monte Carlo study of dosimetry for eye plaque brachytherapy is performed. BrachyDose, an EGSnrc user code which makes use of Yegin's multi-geometry package, is used to fully model {sup 125}I (model 6711) and {sup 103}Pd (model 200) brachytherapy seeds and the standardized plaques of the Collaborative Ocular Melanoma Study (COMS). Three-dimensional dose distributions in the eye region are obtained. In general, dose to water is scored; however, the implications of replacing water with eye tissues are explored. The effect of the gold alloy (Modulay) backing is investigated and the dose is found to be sensitive to the elemental composition of the backing. The presence of the silicone polymer (Silastic) seed carrier results in substantial dose decreases relative to water, particularly for {sup 103}Pd. For a 20 mm plaque with a Modulay backing and Silastic insert, fully loaded with 24 seeds, the dose decrease relative to water is of the order of 14% for {sup 125}I and 20% for {sup 103}Pd at a distance of 1 cm from the inner sclera along the plaque's central axis. For the configurations of seeds used in COMS plaques, interseed attenuation is a small effect within the eye region. The introduction of an air interface results in a dose reduction in its vicinity which depends on the plaque's position within the eye and the radionuclide. Introducing bone in the eye's vicinity also causes dose reductions. The dose distributions in the eye for the two different radionuclides are compared and, for the same prescription dose, {sup 103}Pd generally offers a lower dose to critical normal structures. BrachyDose is sufficiently fast to allow full Monte Carlo dose calculations for routine clinical treatment planning.

Thomson, R. M.; Taylor, R. E. P.; Rogers, D. W. O. [Ottawa Carleton Institute of Physics, Carleton University Campus, Ottawa, K1S 5B6 (Canada)

2008-12-15

345

Uptake of 68gallium in atherosclerotic plaques in LDLR-/-ApoB100/100 mice  

PubMed Central

Background Atherosclerosis is a chronic inflammatory disease of artery wall characterized by infiltration of monocytes into subendothelial space and their differentiation into macrophages. Since rupture-prone plaques commonly contain high amounts of activated macrophages, imaging of the macrophage content may provide a useful tool for the evaluation of plaque vulnerability. The purpose of this study was to explore the uptake of 68gallium (68Ga) in atherosclerotic plaques in mice. Methods Uptake of ionic 68Ga was investigated in atherosclerotic LDLR-/-ApoB100/100 and C57BL/6N control mice at 3 h after injection. The ex vivo biodistribution of the 68Ga was assessed and autoradiography of aortic cryosections was defined. In vivo imaging of 68Ga was performed using a small animal positron emission tomography PET/CT scanner. Results Our results revealed that the uptake of 68Ga-radioactivity was higher in atherosclerotic plaques than in healthy vessel wall (ratio 1.8 ± 0.2, p = 0.0002) and adventitia (ratio 1.3 ± 0.2, p = 0.0011). The autoradiography signal co-localized with macrophages prominently as demonstrated by Mac-3 staining. In both mice strains, the highest level of radioactivity was found in the blood. Conclusions We observed a moderate but significantly elevated 68Ga-radioactivity uptake in the aortic plaques of atherosclerotic mice, especially at the sites rich in macrophages. While the uptake of 68Ga was promising in this animal model, the slow blood clearance may limit the usability of 68Ga as a PET tracer for clinical imaging of atherosclerotic plaques. PMID:22214258

2011-01-01

346

Receptor-targeted Iron Oxide Nanoparticles for Molecular MR Imaging of Inflamed Atherosclerotic Plaques  

PubMed Central

In a number of literature reports iron oxide nanoparticles have been investigated for use in imaging atherosclerotic plaques and found to accumulate in plaques via uptake by macrophages, which are critical in the process of atheroma initiation, propagation, and rupture. However, the uptake of these agents is nonspecific, thus the labeling efficiency for plaques in vivo is not ideal. We have developed targeted agents to improve the efficiency for labeling macrophage-laden plaques. These probes are based on iron oxide nanoparticles coated with dextran sulfate, a ligand of macrophage scavenger receptor type A (SR-A). We have sulfated dextran-coated iron oxide nanoparticles (DIO) with sulfur trioxide, thereby targeting our nanoparticle imaging agents to SR-A. The sulfated DIO (SDIO) remained mono-dispersed and had an average hydrodynamic diameter of 62 nm, an r1 relaxivity of 18.1 mM?1s?1, and an r2 relaxivity of 95.8 mM?1s?1 (37 °C, 1.4 T). Cell studies confirmed that these nanoparticles were nontoxic and specifically targeted to macrophages. In vivo MRI after intravenous injection of the contrast agent into an atherosclerotic mouse injury model showed substantial signal loss on the injured carotid at 4 and 24 hours post-injection of SDIO. No discernable signal decrease was seen at the control carotid and only mild signal loss was observed for the injured carotid post-injection of non-sulfated DIO, indicating preferential uptake of the SDIO particles at the site of atherosclerotic plaque. These results indicate that SDIO can facilitate MRI detection and diagnosis of vulnerable plaques in atherosclerosis. PMID:21742374

Tu, Chuqiao; Ng, Thomas S.C.; Sohi, Hargun; Palko, Heather; House, Adrian; Jacobs, Russell E.; Louie, Angelique Y.

2011-01-01

347

Osteoprotegerin, Pericytes and Bone-Like Vascular Calcification Are Associated with Carotid Plaque Stability  

PubMed Central

Background and Purpose Vascular calcification, recapitulating bone formation, has a profound impact on plaque stability. The aim of the present study was to determine the influence of bone-like vascular calcification (named osteoid metaplasia?=?OM) and of osteoprotegerin on plaque stability. Methods Tissue from carotid endarterectomies were analysed for the presence of calcification and signs of vulnerability according to AHA grading system. Osteoprotegerin (OPG), pericytes and endothelial cells were sought using immuno-histochemistry. Symptoms and preoperative imaging findings (CT-scan, MRI and Doppler-scan) were analyzed. Human pericytes were cultured to evaluate their ability to secrete OPG and to influence mineralization in the plaque. Results Seventy-three carotid plaques (49 asymptomatic and 24 symptomatic) were harvested. A significantly higher presence of OM (18.4% vs 0%, p<0.01), OPG (10.2% of ROI vs 3.4% of ROI, p<0.05) and pericytes (19% of ROI vs 3.8% of ROI, p<0.05) were noted in asymptomatic compared to symptomatic plaques. Consistently, circulating OPG levels were higher in the plasma of asymptomatic patients (3.2 ng/mL vs 2.5 ng/mL, p?=?0.05). In vitro, human vascular pericytes secreted considerable amounts of OPG and underwent osteoblastic differentiation. Pericytes also inhibited the osteoclastic differentiation of CD14+ cells through their secretion of OPG. Conclusions OPG (intraplaque an plasmatic) and OM are associated with carotid plaque stability. Pericytes may be involved in the secretion of intraplaque OPG and in the formation of OM. PMID:25259713

Davaine, Jean-Michel; Quillard, Thibaut; Brion, Regis; Laperine, Olivier; Guyomarch, Beatrice; Merlini, Thierry; Chatelais, Mathias; Guilbaud, Florian; Brennan, Meadhbh Aine; Charrier, Celine; Heymann, Dominique; Goueffic, Yann; Heymann, Marie-Francoise

2014-01-01

348

Delayed Amyloid Plaque Deposition and Behavioral Deficits in Outcrossed A?PP/PS1 Mice  

PubMed Central

Alzheimer’s disease (AD) is a progressive neurodegenerative dementia characterized by amyloid plaque accumulation, synapse/dendrite loss, and cognitive impairment. Transgenic mice expressing mutant forms of amyloid-? precursor protein (A?PP) and presenilin-1 (PS1) recapitulate several aspects of this disease and provide a useful model system for studying elements of AD progression. A?PP/PS1 mice have been previously shown to exhibit behavioral deficits and amyloid plaque deposition between 4–9 months of age. We crossed A?PP/PS1 animals with mice of a mixed genetic background (C57BL/6 × 129/SvJ) and investigated the development of AD-like features in the resulting outcrossed mice. The onset of memory-based behavioral impairment is delayed considerably in outcrossed A?PP/PS1 mice relative to inbred mice on a C57BL/6 background. While inbred A?PP/PS1 mice develop deficits in radial-arm water maze performance and novel object recognition as early as 8 months, outcrossed A?PP/PS1 mice do not display defects until 18 months. Within the forebrain, we find that inbred A?PP/PS1 mice have significantly higher amyloid plaque burden at 12 months than outcrossed A?PP/PS1 mice of the same age. Surprisingly, inbred A?PP/PS1 mice at 8 months have low plaque burden suggesting that plaque burden alone cannot explain the accompanying behavioral deficits. Analysis of A?PP processing revealed that elevated levels of soluble A? correlate with the degree of behavioral impairment in both strains. Taken together, these findings suggest that animal behavior, amyloid plaque deposition, and A?PP processing are sensitive to genetic differences between mouse strains. PMID:23047754

Couch, Brian A.; Kerrisk, Meghan E.; Kaufman, Adam C.; Nygaard, Haakon B.; Strittmatter, Stephen M.; Koleske, Anthony J.

2012-01-01

349

Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma.  

PubMed Central

AIMS/BACKGROUND: To analyse radiation related complications and secondary enucleation after irradiation of malignant uveal melanoma with ruthenium-106 plaques. METHODS: A series of 100 consecutive eyes irradiated in 1981-91 was analysed using the life table method and the Cox proportional hazards model. The median apical and scleral tumour dose was 100 Gy (range 15-200 Gy) and 1000 Gy (range 200-1200 Gy), respectively. The median follow up time was 2.8 and 2.0 years (range 1 month to 10 years) for anterior and posterior segment complications, respectively. RESULTS: The 3 and 5 year probabilities of being without radiation cataract were 73% and 63%, without neovascular glaucoma 91% and 81%, without vitreous haemorrhage 83% and 74%, without radiation maculopathy 85% and 70%, and without radiation optic neuropathy 90% and 88%, respectively. The risk of radiation cataract was highest with large tumour size (T1 + T2 v T3, p = 0.0027; height < or = 5 v > 5 mm, p = 0.029; largest basal diameter (LBD) < or = 15 v > 15 mm, p < 0.0001) and location of anterior tumour margin anterior v posterior to the equator (p = 0.0003); the risk of neovascular glaucoma with large size (T1 + T2 v T3, p = 0.039; LBD < or = 15 mm v 15 mm, p = 0.021); and the risk of maculopathy and optic neuropathy with proximity of the posterior tumour margin to the fovea and the optic disc (< or = 1.5 v > 1.5 mm; p = 0.030 and p = 0.0004, respectively). In Cox's multivariate analysis the strongest risk indicator for radiation cataract (RR 1.5, 95% CI 1.4-1.6) and vitreous haemorrhage (RR 1.6, 95% CI 1.4-1.8) was the height of the tumour; for neovascular glaucoma the TNM class (RR 6.2, 95% CI 2.7-13.8); for radiation maculopathy location of posterior tumour margin within 2 mm from the fovea (RR 3.4, 95% CI 2.0-6.0); and for radiation optic neuropathy location of tumour margin within 1 DD of the optic disc (RR 6.1, 95% CI 3.0-12.4). The 3 and 5 year probabilities of avoiding enucleation were 92% and 85%, respectively. Ten eyes were enucleated--six because of recurrent tumour growth, three because of treatment complications, and one because of mistakenly suspected extraocular growth. CONCLUSION: The results suggest that the frequency of radiation related complications after ruthenium brachytherapy of uveal melanoma is acceptable, in particular as regard irradiation of small and medium sized tumours for which ruthenium therapy generally is recommended. PMID:8949719

Summanen, P; Immonen, I; Kivela, T; Tommila, P; Heikkonen, J; Tarkkanen, A

1996-01-01

350

Feature-based characterization of motion-contaminated calcified plaques in cardiac multidetector CT  

SciTech Connect

In coronary calcium scoring, motion artifacts affecting calcified plaques are commonly characterized using descriptive terms, which incorporate an element of subjectivity in their interpretations. Quantitative indices may improve the objective characterization of these motion artifacts. In this paper, an automated method for generating 12 quantitative indices, i.e., features that characterize the motion artifacts affecting calcified plaques, is presented. This method consists of using the rapid phase-correlated region-of-interest (ROI) tracking algorithm for reconstructing ROI images of calcified plaques automatically from the projection data obtained during a cardiac scan, and applying methods for extracting features from these images. The 12 features include two dynamic, six morphological, and four intensity-based features. The two dynamic features are three-dimensional (3D) velocity and 3D acceleration. The six morphological features include edge-based volume, threshold-based volume, sphericity, irregularity, average margin gradient, and variance of margin gradient. The four intensity-based features are maximum intensity, mean intensity, minimum intensity, and standard deviation of intensity. The 12 features were extracted from 54 reconstructed sets of simulated four-dimensional images from the dynamic NCAT phantom involving six calcified plaques under nine heart rate/multi-sector gating combinations. In order to determine how well the 12 features correlated with a plaque motion index, which was derived from the trajectory of the plaque, partial correlation coefficients adjusted for heart rate, number of gated sectors, and mean feature values of the six plaques were calculated for all 12 features. Features exhibiting stronger correlations (|r| set-membership sign [0.60,1.00]) with the motion index were 3D velocity, maximum intensity, and standard deviation of intensity. Features demonstrating stronger correlations (|r| set-membership sign [0.60,1.00]) with other features mostly involved intensity-based features. Edge-based volume/irregularity and average margin gradient/variance of margin gradient were the only two feature pairs out of 12 with stronger correlations that did not involve intensity-based features. Automatically extracted features of the motion artifacts affecting calcified plaques in cardiac computed tomography images potentially can be used to develop models for predicting image assessability with respect to motion artifacts.

King, Martin; Giger, Maryellen L.; Suzuki, Kenji; Pan, Xiaochuan [Department of Radiology, Committee on Medical Physics, University of Chicago, Chicago, Illinois 60637 (United States)

2007-12-15

351

Thermoelastic displacement measured by DP-OCT for detecting vulnerable plaques  

PubMed Central

The detection of thermoelastic displacement by differential phase optical coherence tomography (DP-OCT) was analytically evaluated for identifying atherosclerotic plaques. Analytical solutions were developed to understand the dynamics of physical distribution of point hear sources during/after laser irradiation on thermoelastic responses of MION-injected tissue. Both analytical and experimental results demonstrated a delayed peak displacement along with slow decay after laser pulse due to heterogeneous distribution of the point heat sources. Detailed description of the heat sources in tissue as well as integration of a scanning mirror can improve computational accuracy as well as clinical applicability of DP-OCT for diagnosing vulnerable plaque. PMID:24575342

Kim, Jihoon; Kang, Hyun Wook; Oh, Junghwan; Milner, Thomas E.

2014-01-01

352

Spontaneous and Procedural Plaque Embolisation in Native Coronary Arteries: Pathophysiology, Diagnosis, and Prevention  

PubMed Central

The detachment of atherothrombotic material from the atherosclerotic coronary plaque and downstream embolisation is an underrecognized phenomenon and it causes different degrees of impairment of the coronary microcirculation. During treatment of obstructive atherosclerotic plaque by percutaneous coronary intervention (PCI) distal embolisation (DE) is considered to be inevitable and it is associated with potential clinical and prognostic implications. This review aims to assess the main aspects of both spontaneous and procedural DE, analyze their different pathophysiology, provide specific insights on the main diagnostic tools for their identification, and finally focus on the main strategies for their treatment and prevention. PMID:24455430

De Maria, Giovanni Luigi; Patel, Niket; Kassimis, George; Banning, Adrian P.

2013-01-01

353

Effect of Chewing Gums Containing Xylitol, Sorbitol or a Mixture of Xylitol and Sorbitol on Plaque Formation, pH Changes and Acid Production in Human Dental Plaque  

Microsoft Academic Search

The aim of the present investigation was to study if xylitol added to a sorbitol-containing chewing gum influenced the pH changes and the acid production activity from sorbitol in plaque. Using a cross-over design, a total of 71 persons were given, 10 times per day for 4 days, three types of chewing gum containing: (1) xylitol; (2) sorbitol, or (3)

V. Topitsoglou; D. Birkhed; L.-Å. Larsson; G. Frostell

1983-01-01

354

A?-Associated cerebral angiopathy and senile plaques with neurofibrillary tangles and cerebral hemorrhage in an aged wolverine ( Gulo gulo)  

Microsoft Academic Search

In this study of an aged wolverine (Gulo gulo), we document neuropathologic lesions (cerebral amyloid angiopathy (CAA), neuritic plaques (NPs), neurofibrillary tangles (NFTs), and granulovacuolar degeneration strikingly similar to those present in aging and Alzheimer's disease (AD), with the additional finding of concurrent cerebral hemorrhage. A? immunoreactive cerebral amyloid angiopathy and senile plaques (neuritic and diffuse) were present throughout the

Karen E. Roertgen; Joseph E. Parisi; H. Brent Clark; Donald L. Barnes; Timothy D. O'Brien; Kenneth H. Johnson

1996-01-01

355

Finite element simulation of slotted tube (stent) with the presence of plaque and artery by balloon expansion  

Microsoft Academic Search

In this paper, results are presented of nonlinear finite element simulations performed to analyse the interactions between the slotted tube (stent) and the plaque or artery using finite element method. The post-expansion response of the slotted tube in the presence of the plaque and artery was also investigated. The analysis was performed using finite element packages LS-DYNA explicit solver for

S. N. David Chua; B. J. MacDonald; M. S. J. Hashmi

2004-01-01

356

Viral plaque analysis on a wide field-of-view, time-lapse, on-chip imaging platform.  

PubMed

The observation of viral plaques is the standard method for determining the viral titer and understanding the behaviors of viruses. Here, we report the application of a wide field-of-view (FOV), time-lapse, on-chip imaging platform, termed the ePetri, for plaque analysis of murine norovirus 1 (MNV-1). The ePetri offers the ability to dynamically track plaques at the individual cell death event level over a wide FOV of 6 mm × 4 mm. As demonstration, we captured high-resolution time-lapse images of MNV-1-infected cells at 30 min intervals. We implemented a customized image-processing program containing a density-based clustering algorithm to analyze the spatial-temporal distribution of cell death events to identify plaques at their earliest stages. By using the results in a viral titer count format, we showed that our approach gives results that are comparable to conventional plaque assays. We further showed that the extra information collected by the ePetri can be used to monitor the dynamics of plaque formation and growth. Finally, we performed a demonstration experiment to show the relevance of such an experimental format for viral inhibitor study. We believe the ePetri is a simple and compact solution for the automation of viral plaque assays, plaque behavior analysis, and antiviral drug discovery and study. PMID:24611157

Han, Chao; Yang, Changhuei

2014-08-01

357

Arsenic rich iron plaque on macrophyte roots an ecotoxicological risk? M.A. Taggart a,b,*, R. Mateo b  

E-print Network

Arsenic rich iron plaque on macrophyte roots ­ an ecotoxicological risk? M.A. Taggart a,b,*, R transfer Wetlands Phytoremediation a b s t r a c t Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalco´ llar mine spill (Spain), residual arsenic

Green, Andy J.

358

Effect of Aerobic and Anaerobic Atmosphere on Acid Production from Sorbitol in Suspensions of Dental Plaque and Oral Streptococci  

Microsoft Academic Search

The pH changes and the amounts of the metabolic end products lactate, formate, acetate and ethanol were studied in suspensions of dental plaque material. The suspensions were incubated with sorbitol or glucose for 30–80 min, in the presence or absence of air. The acid production activity from neither sorbitol nor glucose was affected by the exposure of the plaque suspensions

S. Kalfas; D. Birkhed

1986-01-01

359

Regional Atherosclerotic Plaque Properties in ApoE–\\/– Mice Quantified by Atomic Force, Immunofluorescence, and Light Microscopy  

Microsoft Academic Search

Elucidating regional material properties of arterial tissue is fundamental to predicting transmural stresses and understanding how tissue stiffness influences cellular responses and vice versa. Atomic force microscopy (AFM) was used to measure point-wise the axial compressive stiffness of healthy aortas and atherosclerotic plaques at micron level separation distances. Cross sections of plaques were obtained from a widely used animal model

H. N. Hayenga; A. Trache; J. Trzeciakowski; J. D. Humphrey

2011-01-01

360

Galantamine Slows Down Plaque Formation and Behavioral Decline in the 5XFAD Mouse Model of Alzheimer's Disease  

PubMed Central

The plant alkaloid galantamine is an established symptomatic drug treatment for Alzheimer’s disease (AD), providing temporary cognitive and global relief in human patients. In this study, the 5X Familial Alzheimer’s Disease (5XFAD) mouse model was used to investigate the effect of chronic galantamine treatment on behavior and amyloid ? (A?) plaque deposition in the mouse brain. Quantification of plaques in untreated 5XFAD mice showed a gender specific phenotype; the plaque density increased steadily reaching saturation in males after 10 months of age, whereas in females the density further increased until after 14 months of age. Moreover, females consistently displayed a higher plaque density in comparison to males of the same age. Chronic oral treatment with galantamine resulted in improved performance in behavioral tests, such as open field and light-dark avoidance, already at mildly affected stages compared to untreated controls. Treated animals of both sexes showed significantly lower plaque density in the brain, i.e., the entorhinal cortex and hippocampus, gliosis being always positively correlated to plaque load. A high dose treatment with a daily uptake of 26 mg/kg body weight was tolerated well and produced significantly larger positive effects than a lower dose treatment (14 mg/kg body weight) in terms of plaque density and behavior. These results strongly support that galantamine, in addition to improving cognitive and behavioral symptoms in AD, may have disease-modifying and neuroprotective properties, as is indicated by delayed A? plaque formation and reduced gliosis. PMID:24586789

Bhattacharya, Soumee; Haertel, Christin; Maelicke, Alfred; Montag, Dirk

2014-01-01

361

Manifestation of palmoplantar pustulosis during or after infliximab therapy for plaque-type psoriasis: report on five cases.  

PubMed

Infliximab is a monoclonal antibody directed against TNF-alpha. It has been approved for use in rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, psoriatic arthritis and plaque-type psoriasis. In case reports, positive effects on pustular variants of psoriasis have also been reported. However, paradoxically, manifestation of pustular psoriasis and plaque-type psoriasis has been reported in patients treated with TNF antagonists including infliximab for other indications. Here, we report on 5 patients with chronic plaque-type psoriasis who developed palmoplantar pustulosis during or after discontinuation of infliximab therapy. In two of the five cases, manifestation of palmoplantar pustulosis was not accompanied by worsening of plaque-type psoriasis. Possibly, site-specific factors or a differential contribution of immunological processes modulated by TNF inhibitors to palmoplantar pustulosis and plaque-type psoriasis may have played a role. PMID:18239925

Mössner, Rotraut; Thaci, Diamant; Mohr, Johannes; Pätzold, Sylvie; Bertsch, Hans Peter; Krüger, Ullrich; Reich, Kristian

2008-03-01

362

Manifestation of palmoplantar pustulosis during or after infliximab therapy for plaque-type psoriasis: report on five cases  

PubMed Central

Infliximab is a monoclonal antibody directed against TNF-?. It has been approved for use in rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, psoriatic arthritis and plaque-type psoriasis. In case reports, positive effects on pustular variants of psoriasis have also been reported. However, paradoxically, manifestation of pustular psoriasis and plaque-type psoriasis has been reported in patients treated with TNF antagonists including infliximab for other indications. Here, we report on 5 patients with chronic plaque-type psoriasis who developed palmoplantar pustulosis during or after discontinuation of infliximab therapy. In two of the five cases, manifestation of palmoplantar pustulosis was not accompanied by worsening of plaque-type psoriasis. Possibly, site-specific factors or a differential contribution of immunological processes modulated by TNF inhibitors to palmoplantar pustulosis and plaque-type psoriasis may have played a role. PMID:18239925

Thaci, Diamant; Mohr, Johannes; Pätzold, Sylvie; Bertsch, Hans Peter; Krüger, Ullrich; Reich, Kristian

2008-01-01

363

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

364

Development of gas-phase metallized plaques for electrodes of storage batteries, in particular for nickel oxide electrodes  

NASA Astrophysics Data System (ADS)

Nickel oxide-electrode plaques for alkaline batteries have been developed by carbon vapor deposition plating fiber plaque substrates with nickel from nickelcarbonyo. Carbon felt proved to be a suitable substrate and large (22 x sq 15 sq cm) and thick 3 - 5 mm) plaques could be made from this material. Three metallization devices were constructed, one of which allowed continuous processing with carbonyl gas flowing through the felt; this improved evenness of nickel distribution. The physical properties of the plaques - structure, electric resistance, heat conduction, gas permeation - approximated by simple models and the corresponding calculations were compared with measurements. Nickel oxide electrodes were made from the plaques and were cycled in half-cell arrangements. The project goals concerning nickel sayings, capacity per unit area and current capability were reached.

Linkohr, R.; Schladitz, H.

1982-08-01

365

The Fat-Fed Apolipoprotein E Knockout Mouse Brachiocephalic Artery in the Study of Atherosclerotic Plaque Rupture  

PubMed Central

Atherosclerosis has been studied in animals for almost a century, yet the events leading up to the rupture of an atherosclerotic plaque (the underlying cause of the majority of fatal thrombosis formation) have only been studied in the past decade, due in part to the development of a mouse model of spontaneous plaque rupture. Apolipoprotein E knockout mice, when fed a high-fat diet, consistently develop lesions in the brachiocephalic artery that rupture at a known time point. It is therefore now possible to observe the development of lesions to elucidate the mechanisms behind the rupture of plaques. Critics argue that the model does not replicate the appearance of human atherosclerotic plaque ruptures. The purpose of this review is to highlight the reasons why we should be looking to the apolipoprotein E knockout mouse to further our understanding of plaque rupture. PMID:21076539

Bond, Andrew R.; Jackson, Christopher L.

2011-01-01

366

Impact of statin use before the onset of acute myocardial infarction on coronary plaque morphology of the culprit lesion.  

PubMed

Statins favorably stabilize coronary plaque. We evaluated the impact of statin use before the onset of acute myocardial infarction (AMI) on culprit lesion plaque morphology. Patients (n = 127) with AMI were divided into either a statin group (n = 31) or a nonstatin group (n = 96) based on statin use before the onset of AMI. Coronary plaque morphology of the culprit lesion was evaluated using intravascular ultrasound virtual histology (IVUS-VH) with radiofrequency data analysis before coronary intervention. The IVUS-VH identified 4 types of plaque components: fibrous, fibrofatty, dense calcium, and necrotic core. The IVUS-VH showed less percentage of necrotic area, greater percentage fibrous area, and greater percentage of fibrofatty area of the culprit lesion in the statin group. In conclusion, statin use before the onset of AMI might have effects on coronary plaque morphology of the AMI culprit lesion with less necrotic core and greater fibrous and fibrofatty component. PMID:22679133

Hikita, Hiroyuki; Kuroda, Shunsuke; Oosaka, Yuki; Kawaguchi, Naohiko; Nakashima, Emiko; Sugiyama, Tomoyo; Akiyama, Daiki; Kamiishi, Tetsuo; Kimura, Shigeki; Takahashi, Yoshihide; Kuwahara, Taishi; Sato, Akira; Takahashi, Atsushi; Isobe, Mitsuaki

2013-07-01

367

Chronic ?-secretase inhibition reduces amyloid plaque-associated instability of pre- and postsynaptic structures  

PubMed Central

The loss of synapses is a strong histological correlate of the cognitive decline in Alzheimer's disease (AD). Amyloid ??peptide (A?), a cleavage product of the amyloid precursor protein (APP), exerts detrimental effects on synapses, a process thought to be causally related to the cognitive deficits in AD. Here, we used in vivo two-photon microscopy to characterize the dynamics of axonal boutons and dendritic spines in APP/Presenilin 1 (APPswe/PS1L166P)–green fluorescent protein (GFP) transgenic mice. Time-lapse imaging over 4 weeks revealed a pronounced, concerted instability of pre- and postsynaptic structures within the vicinity of amyloid plaques. Treatment with a novel sulfonamide-type ?-secretase inhibitor (GSI) attenuated the formation and growth of new plaques and, most importantly, led to a normalization of the enhanced dynamics of synaptic structures close to plaques. GSI treatment did neither affect spines and boutons distant from plaques in amyloid precursor protein/presenilin 1-GFP (APPPS1-GFP) nor those in GFP-control mice, suggesting no obvious neuropathological side effects of the drug. PMID:24061497

Liebscher, S; Page, R M; Kafer, K; Winkler, E; Quinn, K; Goldbach, E; Brigham, E F; Quincy, D; Basi, G S; Schenk, D B; Steiner, H; Bonhoeffer, T; Haass, C; Meyer-Luehmann, M; Hubener, M

2014-01-01

368

Detection of Helicobacter pylori in dental plaque by reverse transcription-polymerase chain reaction.  

PubMed Central

To investigate whether the oral cavity is a potential reservoir and possible sanctuary for Helicobacter pylori, supragingival and subgingival plaques were analyzed by a Helicobacter genus-specific reverse transcriptase-polymerase chain reaction based on the sequence data of H. pylori 16S rRNA. The amplified 500-bp DNA fragment was identified by ethidium bromide staining after agarose gel electrophoresis and by Southern hybridization. Twenty-five dyspeptic patients were studied. Histologic examination of gastric biopsy specimens revealed that 18 had H. pylori gastritis and 7 did not. For seven of the 18 (38.8%) patients with proven H. pylori gastritis, H. pylori was also identified in their dental plaque. None of the patients without H. pylori gastritis had H. pylori in their dental plaque. The detection of H. pylori in dental plaque suggests that this H. pylori colonization is not restricted to the gastric mucosa and that this ecological niche may serve as a possible sanctuary which may be responsible for reinoculation of the stomach after topical anti-H. pylori therapies such as bismuth. Images PMID:8463387

Nguyen, A M; Engstrand, L; Genta, R M; Graham, D Y; el-Zaatari, F A

1993-01-01

369

Quantitative Analysis of Circumferential Plaque Distribution in Human Coronary Arteries in  

E-print Network

Quantitative Analysis of Circumferential Plaque Distribution in Human Coronary Arteries in Relation · Symptomatic coronary artery disease and atherosclerosis are among the leading causes of death in many to be understood. · 3-D Fusion of x-ray coronary angiography and intravascular ultrasound (IVUS) data allows

Wahle, Andreas

370

Mechanisms of plaque stabilization for the dihydropyridine calcium channel blocker amlodipine: review of the evidence  

Microsoft Academic Search

Coronary artery disease (CAD) is the consequence of atherosclerosis, a vascular disorder that is the leading cause of death and disability throughout much of the developed world. Certain cellular changes in the vulnerable atherosclerotic plaque are characterized by a loss of normal calcium regulation. This observation has led to interest in a potential antiatherogenic role for calcium channel blockers (CCBs),

R. Preston Mason

2002-01-01

371

Computational approaches for analyzing the mechanics of atherosclerotic plaques: a review.  

PubMed

Vulnerable and stable atherosclerotic plaques are heterogeneous living materials with peculiar mechanical behaviors depending on geometry, composition, loading and boundary conditions. Computational approaches have the potential to characterize the three-dimensional stress/strain distributions in patient-specific diseased arteries of different types and sclerotic morphologies and to estimate the risk of plaque rupture which is the main trigger of acute cardiovascular events. This review article attempts to summarize a few finite element (FE) studies for different vessel types, and how these studies were performed focusing on the used stress measure, inclusion of residual stress, used imaging modality and material model. In addition to histology the most used imaging modalities are described, the most common nonlinear material models and the limited number of models for plaque rupture used for such studies are provided in more detail. A critical discussion on stress measures and threshold stress values for plaque rupture used within the FE studies emphasizes the need to develop a more location and tissue-specific threshold value, and a more appropriate failure criterion. With this addition future FE studies should also consider more advanced strain-energy functions which then fit better to location and tissue-specific experimental data. PMID:24491496

Holzapfel, Gerhard A; Mulvihill, John J; Cunnane, Eoghan M; Walsh, Michael T

2014-03-01

372

Subcellular localization of amyloid precursor protein in senile plaques of Alzheimer's disease.  

PubMed Central

The authors have previously shown that amyloid precursor protein (APP) accumulates in neurites present in senile plaques of Alzheimer's disease (AD). In this ultrastructural immunocytochemical study, we describe the subcellular site of APP accumulation. Vibratome sections of glutaraldehyde-paraformaldehyde fixed hippocampi from five cases of AD were pretreated with methanol and immunostained with an antibody raised against recombinant APP 770 by using either indirect immunogold or peroxidase methods. Immunolabeling was localized in cell processes filled with amorphous, irregular-shaped materials, which were identified as dense bodies deformed by postmortem autolysis and methanol treatment, as well as multilamellar membranous bodies. Identification of these bodies was obtained with comparative ultrastructural examination of biopsy and autopsy tissue fixed with and without methanol treatment. These electron-dense organellae were positive for the lysosomal marker, acid phosphatase. At light microscopy, acid phosphatase and APP colocalized to the same cell processes in senile plaques. Many of those cell processes contained abnormal straight or paired helical filaments supporting their neuritic nature. These results suggest that APP accumulates in the lysosomal system of the dystrophic neurites present in senile plaques and are consistent with a neuronal origin of the APP forming the amyloid in senile plaques. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:1562053

Kawai, M.; Cras, P.; Richey, P.; Tabaton, M.; Lowery, D. E.; Gonzalez-DeWhitt, P. A.; Greenberg, B. D.; Gambetti, P.; Perry, G.

1992-01-01

373

Three Retinoid X Receptor Gene Polymorphisms in Plaque Psoriasis and Psoriasis Guttata  

Microsoft Academic Search

Aim: Polymorphisms in retinoid X receptors (RXRs) are very interesting from the point of view of a possible association of their variability with psoriasis. Methods: A total of 293 patients with plaque psoriasis, 82 patients with psoriasis guttata and 202 control subjects were enrolled in this study focused on 3 polymorphisms in RXRA and RXRB gene associations. Results: A marginally

Monika Pávková Goldbergová

2007-01-01

374

Current Computed Tomography Techniques Can Detect Duct of Bellini Plugging but not Randall's Plaques  

PubMed Central

Objectives To assess the ability of noninvasive computed tomography (CT) scans to detect interstitial calcium phosphate deposits (Randall's plaques) and duct of Bellini plugs, which are possible stone precursor lesions. Methods At time of percutaneous nephrolithotomy (PCNL) for stone removal, all accessible individual papillae of 105 patients were endoscopically visualized and video recorded. Image processing software was used to estimate the percentage papillary surface occupied by plaque or plug in each pole (upper, mid, lower). The location of stones was also recorded. A radiologist blinded to the mapping results scored pre surgical (n=98) and post surgical (n=105) abdominal CT scans for the presence or absence of calcification by pole. Results Mean age of the cohort was 56 years [range 23-84]. Maximum papillary surface area of each area of the kidney occupied by plug correlated with CT calcifications on both pre and post procedure images by rank sum test. However, maximum plaque surface area did not correlate with radiographic findings (p range from 0.10-0.90 for each pole by rank sum test). Sensitivity and specificity of CT to detect plugs of at least 1% of the papillary surface area was 81% and 69%, respectively. Conclusion Calcifications seen on current generation clinical CT scans correspond to ductal plugging involving at least 1% of the papillary surface area. Current clinical CT scan technology appears inadequate for detecting Randall's plaques. PMID:23791212

Krambeck, Amy E.; Lieske, John C.; Li, Xujian; Bergstralh, Eric J.; Rule, Andrew D.; Holmes, David; McCollough, Cynthia. M; Vrtiska, Terri J.

2013-01-01

375

Clinically stable angina pectoris is not necessarily associated with histologically stable atherosclerotic plaques  

Microsoft Academic Search

OBJECTIVE: To investigate the extent of plaque inflammation in culprit lesions of patients with chronic stable angina. DESIGN: Retrospective study. SETTING: Amsterdam reference centre. SUBJECTS: 89 consecutive patients who underwent directional coronary atherectomy, 58 of whom met the following inclusion criteria: chronic stable angina (Canadian Cardiovascular Society classification 1-3 (group 1, n = 28)); unstable angina (Braunwald class II (group

A. C. van der Wal; A. E. Becker; K. T. Koch; J. J. Piek; P. Teeling; C. M. van der Loos; G. K. David

1996-01-01

376

Flourescence analysis of ALA-induced Protoporphyrin IX in psoriatic plaque  

NASA Astrophysics Data System (ADS)

The success reported for the treatment of superficial skin carcinomas by photodynamic therapy (PDT), following topical application of 5-aminolaevulinic acid (ALA), has therapeutic implications for the treatment of other skin disorders. This presentation describes the accumulation of the photosensitizing agent protoporphyrin IX (PpIX) in areas of psoriatic plaque, by monitoring the fluorescence emission induced by low-intensity laser excitation at 488 nm. We present the results from 15 patients, with a total of 42 plaques. These results show that PpIX fluorescence increases in intensity within the 6 hour period following application of ALA, which implies there is a potential for PDT. The emission is localized to the area of ALA application and the effect of occlusion appears insignificant. Also, the rate of increase, and maximum intensity of fluorescence emission, is not directly related to the applied quantity of ALA. The variability of the fluorescence intensity is as great between plaques at different sites on the same patient as between different patients. We also present measurements of the depletion in intensity of fluorescence emission during PDT treatment, using white light, at an irradiance of 25 mW cm-2, that is a consequence of the molecular photo-oxidation of PpIX. The use of fluorescence measurements in predicting the therapeutic effect of treating plaque psoriasis by ALA-PDT is discussed.

Stringer, Mark R.; Robinson, Dominic J.; Collins, P.

1996-01-01

377

Painting blood vessels and atherosclerotic plaques with an adhesive drug depot  

E-print Network

Painting blood vessels and atherosclerotic plaques with an adhesive drug depot Christian J to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine

Strynadka, Natalie

378

Myeloid I?B? Deficiency Promotes Atherogenesis by Enhancing Leukocyte Recruitment to the Plaques  

PubMed Central

Activation of the transcription factor NF-?B appears to be involved in different stages of atherogenesis. In this paper we investigate the role of NF-?B inhibitor I?B? in atherosclerosis. Myeloid-specific deletion of I?B? results in larger and more advanced lesions in LDL-R-deficient mice without affecting the compositional phenotype of the plaques or systemic inflammatory markers in the plasma. We show that I?B?-deleted macrophages display enhanced adhesion to an in vitro endothelial cell layer, coinciding with an increased expression of the chemokine CCL5. Also, in vivo we found that I?B?del mice had more leukocytes adhering to the luminal side of the endothelial cell layers that cover the atherosclerotic plaques. Moreover, we introduce ER-MP58 in this paper as a new immunohistochemical tool for quantifying newly recruited myeloid cells in the atherosclerotic lesion. This staining confirms that in I?B?del mice more leukocytes are attracted to the plaques. In conclusion, we show that I?B? deletion in myeloid cells promotes atherogenesis, probably through an induced leukocyte recruitment to plaques. PMID:21814576

Goossens, Pieter; Vergouwe, Monique N.; Gijbels, Marion J. J.; Curfs, Danielle M. J.; van Woezik, Johannes H. G.; Hoeksema, Marten A.; Xanthoulea, Sofia; Leenen, Pieter J. M.; Rupec, Rudolf A.; Hofker, Marten H.; de Winther, Menno P. J.

2011-01-01

379

Evaluation of the Efficacy of a Dental Plaque Control Program in Autistic Patients  

ERIC Educational Resources Information Center

The aim of this study was to verify the efficacy of a programme for dental plaque control in autistics. Patients were evaluated on five occasions over a period of 180 days using the following instruments: OHI-S, DMF-T, the Fonnes brushing technique and diet questionnaire. Participants were divided into two groups according to level of co-operation…

Dias, Guilherme G.; Prado, Eliane F. G. B.; Vadasz, Estevao; Siqueira, Jose Tadeu T.

2010-01-01

380

Relationship among Dental Plaque Composition, Daily Sugar Exposure and Caries in the Primary Dentition  

Microsoft Academic Search

The relationship among daily sugar exposure, dental plaque composition and caries patterns in the primary dentition is not known. Three groups of 20 children (18–48 months old) were studied: (1) caries-free (CF), (2) presenting pit and fissure caries (PFC), and (3) with nursing caries (NC). Dental caries index (dmfs) was assessed and the frequency of daily sugar exposure (TS) and

M. Nobre dos Santos; L. Melo dos Santos; S. B. Francisco; J. A. Cury

2002-01-01

381

Clinical and Capillaroscopic Modifications of the Psoriatic Plaque during Therapy: Observations with Oral Acitretin  

PubMed Central

Psoriasis is considered to be an inflammatory autoimmune disease, where angiogenesis plays an undefined pathogenetic role. The well-known changes of the superficial microvasculature in the psoriatic plaque can be easily assessed in vivo by videocapillaroscopy. In the last years, several studies reported the clinical and capillaroscopic response of the psoriatic plaque during different topical and systemic treatments. In the present work we evaluated the effects of acitretin (0.8?mg/kg/day) on videocapillaroscopic alterations and the clinical response in 11 patients affected by plaque psoriasis at the baseline (T0) and after 4 (T1), 8 (T2), and 12 (T3) weeks. A clinical improvement during the treatment with a complete clinical healing of the plaque in 7 of the 11 patients was observed. The typical “basket-weave” capillaries of the psoriatic lesions showed a reduction of 65.4% in diameter at the end of the study; only 3 patients returned to a normal capillaroscopic pattern. As observed during previous our studies, we found a discrepancy between clinical and capillaroscopic results, with a far greater improvement in the first than in the second. This finding could be in agreement with a secondary role of blood vessels in the pathogenesis and persistence of psoriatic lesions. PMID:24174931

Buligan, Cinzia; Errichetti, Enzo; Valent, Francesca

2013-01-01

382

The effect of orthodontic appliances on the distribution of Candida and plaque in adolescents.  

PubMed

The site prevalence and intra-oral density of Candidal organisms may be increased by local factors including prostheses. However, whether significant changes in Candidal carriage occurs with denture wearing is not clearly established. This study employed the imprint culture technique to assess the effects of fixed and removable orthodontic appliances on oral carriage, site prevalence and intra-oral density of Candida in adolescents. Moreover, alterations in plaque distribution were measured. Groups of 12-16 year olds without or wearing fixed and removable appliances were studied. Imprint cultures were taken from six intra-oral sites and colony counts recorded after 48 hours incubation on selective media. Plaque scores were recorded from non-appliance and removable appliance wearers. The prevalence of Candidal carriage in the groups was not significantly different being 46 per cent of non-appliance, 51 per cent of fixed appliance and 52 per cent of removable appliance wearers. However, the prevalence of Candidal recovery at some sites and Candidal densities at all sites were significantly increased in both fixed and removable appliance wearers. Thus orthodontic appliances may predispose to Candidal proliferation in oral carriers. However, the results do not permit the conclusion that appliances may change non-carriers of Candida to carriers. Plaque distribution was significantly altered in removable appliance wearers when compared with non-appliance wearers as a result of increases in palatal plaque scores. These findings again emphasize the particular need for oral hygiene instruction in patients wearing appliances or partial prostheses. PMID:6954991

Addy, M; Shaw, W C; Hansford, P; Hopkins, M

1982-07-01

383

Regional Adipose Tissue Associations With Calcified Atherosclerotic Plaque: African American–Diabetes Heart Study  

Microsoft Academic Search

Coronary artery calcified atherosclerotic plaque (CP) is strongly associated with nonsubcutaneous adipose tissue, particularly pericardial adipose tissue (PAT), in community-based studies. We tested for relationships between regional adipose tissue depots and CP in African Americans with longstanding type 2 diabetes. Infrarenal aorta, coronary, and carotid artery CP and pericardial, visceral, intermuscular, and subcutaneous organ-specific adipose tissue volumes were measured using

Jasmin Divers; Lynne E. Wagenknecht; Donald W. Bowden; J. Jeffrey Carr; R. Caresse Hightower; Jingzhong Ding; Jianzhao Xu; Carl D. Langefeld; Barry I. Freedman

2010-01-01

384

Increased brain iron coincides with early plaque formation in a mouse model of Alzheimer's disease  

Microsoft Academic Search

Elevated brain iron content, which has been observed in late-stage human Alzheimer's disease, is a potential target for early diagnosis. However, the time course for iron accumulation is currently unclear. Using the PSAPP mouse model of amyloid plaque formation, we conducted a time course study of metal ion content and distribution [iron (Fe), copper (Cu), and zinc (Zn)] in the

A. C. Leskovjan; L. Miller; A. Kretlow; A. Lanzirotti; R. Barrea; S. Vogt

2010-01-01

385

Increased brain iron coincides with early plaque formation in a mouse model of Alzheimer's disease  

Microsoft Academic Search

Elevated brain iron content, which has been observed in late-stage human Alzheimer's disease, is a potential target for early diagnosis. However, the time course for iron accumulation is currently unclear. Using the PSAPP mouse model of amyloid plaque formation, we conducted a time course study of metal ion content and distribution [iron (Fe), copper (Cu), and zinc (Zn)] in the

Andreana C. Leskovjan; Ariane Kretlow; Antonio Lanzirotti; Raul Barrea; Stefan Vogt; Lisa M. Miller

2011-01-01

386

Detection of yellow fever virus: a comparison of quantitative real-time PCR and plaque assay  

Microsoft Academic Search

Yellow fever virus quantitation is performed routinely by cultivation of virus containing samples using susceptible cells. Counting of the resulting plaques provides a marker for the number of infectious particles present in the sample. This assay usually takes up to 5 days before results are obtained and must be carried out under L2 or L3 laboratory conditions, depending on the

Hi-Gung Bae; Andreas Nitsche; Anette Teichmann; Stefan S. Biel; Matthias Niedrig

2003-01-01

387

Spotty calcification typifies the culprit plaque in patients with acute myocardial infarction: An intravascular ultrasound study  

Microsoft Academic Search

Background—Calcification is a common finding in human coronary arteries; however, the relationship between calcification patterns, plaque morphology, and patterns of remodeling of culprit lesions in a comparison of patients with acute coronary syndromes (ACS) and those with stable conditions has not been documented. Methods and Results—Preinterventional intravascular ultrasound (IVUS) images of 178 patients were studied, 61 with acute myocardial infarction

Shoichi Ehara; Yoshiki Kobayashi; Minoru Yoshiyama

2005-01-01

388

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

PubMed

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. PMID:22287230

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

2012-04-01

389

Cytogenetic analysis reveals clonal proliferation of smooth muscle cells in atherosclerotic plaques  

Microsoft Academic Search

Cytogenetic analysis of primary cell cultures from human atherosclerotic fibrous plaques revealed clonal chromosome abnormalities in 13 of the 18 cases studied. Loss of the Y chromosome and del(13)(q14) were present as single clonal abnormalities in eight cases; in five cases separate clones were found involving loss of the Y and a XXY karyotype, trisomy 10 and 18, loss of

R. Casalone; P. Granata; E. Minelli; P. Portentoso; A. Giudici; R. Righi; P. Castelli; A. Socrate; B. Frigerio

1991-01-01

390

Chronic ?-secretase inhibition reduces amyloid plaque-associated instability of pre- and postsynaptic structures.  

PubMed

The loss of synapses is a strong histological correlate of the cognitive decline in Alzheimer's disease (AD). Amyloid ?-peptide (A?), a cleavage product of the amyloid precursor protein (APP), exerts detrimental effects on synapses, a process thought to be causally related to the cognitive deficits in AD. Here, we used in vivo two-photon microscopy to characterize the dynamics of axonal boutons and dendritic spines in APP/Presenilin 1 (APP(swe)/PS1(L166P))-green fluorescent protein (GFP) transgenic mice. Time-lapse imaging over 4 weeks revealed a pronounced, concerted instability of pre- and postsynaptic structures within the vicinity of amyloid plaques. Treatment with a novel sulfonamide-type ?-secretase inhibitor (GSI) attenuated the formation and growth of new plaques and, most importantly, led to a normalization of the enhanced dynamics of synaptic structures close to plaques. GSI treatment did neither affect spines and boutons distant from plaques in amyloid precursor protein/presenilin 1-GFP (APPPS1-GFP) nor those in GFP-control mice, suggesting no obvious neuropathological side effects of the drug. PMID:24061497

Liebscher, S; Page, R M; Käfer, K; Winkler, E; Quinn, K; Goldbach, E; Brigham, E F; Quincy, D; Basi, G S; Schenk, D B; Steiner, H; Bonhoeffer, T; Haass, C; Meyer-Luehmann, M; Hübener, M

2014-08-01

391

Aminonaphthalene 2Cyanoacrylate (ANCA) Probes Fluorescently Discriminate between Amyloid and Prion Plaques in Brain  

E-print Network

and Prion Plaques in Brain Kevin Cao, Mona Farahi, Marianna Dakanali, Willy M. Chang, Christina J. Sigurdson- (A) peptides associated with AD or from prion (PrPSc ) proteins associated with prion disease (Figure) PrPSc deposits in the corpus callosum of a prion-infected mouse. (C) Ex vivo fluorescence spectra

Theodorakis, Emmanuel

392

In vivo dental plaque pH variation with regular and diet soft drinks  

Microsoft Academic Search

Purpose: Despite the presence or absence of artificial sweeteners in cola drinks, both regular and diet soft drinks still contain phosphoric and citric acid, which contributes to the total acidic challenge potential on enamel. The purpose of this study was to assess the plaque pH, in vivo, after a substrate challenge of diet and regular soft drinks. Methods: Seventeen subjects

Erik H. Roos; Kevin J. Donly

2002-01-01

393

Prediction of coronary plaque location on arteries having myocardial bridge, using finite element models.  

PubMed

This study was performed to evaluate the influences of the myocardial bridges on the plaque initializations and progression in the coronary arteries. The wall structure is changed due to the plaque presence, which could be the reason for multiple heart malfunctions. Using simplified parametric finite element model (FE model) of the coronary artery having myocardial bridge and analyzing different mechanical parameters from blood circulation through the artery (wall shear stress, oscillatory shear index, residence time), we investigated the prediction of "the best" position for plaque progression. We chose six patients from the angiography records and used data from DICOM images to generate FE models with our software tools for FE preprocessing, solving and post-processing. We found a good correlation between real positions of the plaque and the ones that we predicted to develop at the proximal part of the myocardial bridges with wall shear stress, oscillatory shear index and residence time. This computer model could be additional predictive tool for everyday clinical examination of the patient with myocardial bridge. PMID:25139775

Nikoli?, Dalibor; Radovi?, Miloš; Aleksandri?, Sr?an; Tomaševi?, Miloje; Filipovi?, Nenad

2014-11-01

394

MICA/B expression in macrophage foam cells infiltrating atherosclerotic plaques.  

PubMed

Infiltrating macrophages accumulate in fatty streak lesions and transform into foam cells, leading to the formation of atherosclerotic plaques. Inflammatory mechanisms underlying the plaque formation mediated by NKG2D-positive lymphocytes such as CD8+ T cells, natural killer cells and natural killer T cells have been extensively investigated. Yet, the involvement of the NKG2D system itself remains poorly understood. Recent work in mouse models has shown that blockade of an NKG2D receptor-ligand interaction reduces plaque formation and suppresses inflammation in aortae. In this study, we conducted immunohistochemical analysis of NKG2D ligand expression in autopsy-derived aortic specimens. Foam cells expressing NKG2D ligands MICA/B were found in advanced atherosclerotic lesions accompanied by a large necrotic core or hemorrhage. Human monocyte-derived macrophages treated in vitro with acetylated low-density lipoproteins enhanced expression of MICA/B and scavenger receptor A, thus accounting for NKG2D ligand expression in foam cells infiltrating atherosclerotic plaques. Our results suggest that, as in mice, the NKG2D system might be involved in the development of atherosclerosis in humans. PMID:24997223

Ikeshita, Shunji; Miyatake, Yukiko; Otsuka, Noriyuki; Kasahara, Masanori

2014-08-01

395

Microbial Diversity Similarities in Periodontal Pockets and Atheromatous Plaques of Cardiovascular Disease Patients  

PubMed Central

Background and Objective The immune and infectious alterations occurring in periodontitis have been shown to alter the development and severity of cardiovascular disease. One of these relationships is the translocation of oral bacteria to atheroma plaques, thereby promoting plaque development. Thus, the aim of this study was to assess, by 16s cloning and sequencing, the microbial diversity of the subgingival environment and atheroma plaques of patients concomitantly suffering from periodontitis and obstructive coronary artery atherosclerosis (OCAA). Methods Subgingival biofilm and coronary balloons used in percutaneous transluminal coronary angioplasty were collected from 18 subjects presenting with generalized moderate to severe periodontitis and OCAA. DNA was extracted and the gene 16S was amplified, cloned and sequenced. Results Significant differences in microbial diversity were observed between both environments. While subgingival samples mostly contained the phylum Firmicutes, in coronary balloons, Proteobacteria (p<0.05) was predominant. In addition, the most commonly detected genera in coronary balloons were Acinetobacter, Alloprevotella, Pseudomonas, Enterobacter, Sphingomonas and Moraxella, while in subgingival samples Porphyromonas, Filifactor, Veillonella, Aggregatibacter and Treponema (p<0.05) were found. Interestingly, 17 identical phylotypes were found in atheroma and subgingival samples, indicating possible bacterial translocation between periodontal pockets and coronary arteries. Conclusion Periodontal pockets and atheromatous plaques of cardiovascular disease patients can present similarities in the microbial diversity. PMID:25329160

Serra e Silva Filho, Wagner; Casarin, Renato C. V.; Nicolela Junior, Eduardo L.; Passos, Humberto M.; Sallum, Antonio W.; Goncalves, Reginaldo B.

2014-01-01

396

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

PubMed

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

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

2014-11-01

397

Cytomegalovirus localization in atherosclerotic plaques is associated with acute coronary syndromes: report of 105 patients.  

PubMed

It has been shown that cytomegalovirus (CMV) is present in coronary atherosclerotic plaques, but the clinical relevance of this presence remains to be elucidated. In this study we sought to examine CMV infection in atherosclerosis patients defined by different methods and to identify the clinical significance of CMV replication in the atherosclerotic plaques. The study included 105 consecutive patients who were admitted to our department and underwent coronary artery bypass grafting (CABG) surgical interventions. Coronary atherosclerotic specimens as well as 53 specimens from the mamillary artery of these same patients were analyzed. Enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) methods were used for evaluations. The CMV PCR test result was positive for 28 (26.7%) of patients with coronary artery atherosclerosis. After adjusting for other risk factors, coronary artery disease patients with a history of acute coronary syndrome were more likely to be positive for CMV PCR test (P=0.027; odds ratio: 4.2; 95% CI: 1.18-15.0). They were also more likely to have a positive family history for cardiovascular diseases (CVD). This study confirms previous evidence about the replication of CMV virus in the atherosclerotic plaques of coronary arteries and brings clinical significance to this observation by showing a higher prevalence of acute coronary syndromes in those patients with CMV-infected plaques. Our study also suggests a familial vulnerability to CMV replication in the coronary artery walls. PMID:22891128

Izadi, Morteza; Fazel, Mozhgan; Saadat, Seyed Hassan; Nasseri, Mohammad Hassan; Ghasemi, Mojtaba; Dabiri, Hossein; Aryan, Reza Safi; Esfahani, Ali Akbar; Ahmadi, Ali; Kazemi-Saleh, Davood; Kalantar-Motamed, Mohammad Hassan; Taheri, Saeed

2012-01-01

398

Cytomegalovirus Localization in Atherosclerotic Plaques is Associated with Acute Coronary Syndromes: Report of 105 Patients  

PubMed Central

It has been shown that cytomegalovirus (CMV) is present in coronary atherosclerotic plaques, but the clinical rele-vance of this presence remains to be elucidated. In this study we sought to examine CMV infection in atherosclerosis patients defined by different methods and to identify the clinical significance of CMV replication in the atherosclerotic plaques. The study included 105 consecutive patients who were admitted to our department and underwent coronary artery bypass grafting (CABG) surgical interventions. Coronary atherosclerotic specimens as well as 53 specimens from the mamillary artery of these same patients were analyzed. Enzyme-linked immunosorbent assay (ELISA) and poly-merase chain reaction (PCR) methods were used for evaluations. The CMV PCR test result was positive for 28 (26.7%) of patients with coronary artery atherosclerosis. After adjusting for other risk factors, coronary artery disease patients with a history of acute coronary syndrome were more likely to be positive for CMV PCR test (P=0.027; odds ratio: 4.2; 95% CI: 1.18-15.0). They were also more likely to have a positive family history for cardiovascular diseases (CVD). This study confirms previous evidence about the replication of CMV virus in the atherosclerotic plaques of coronary arteries and brings clinical significance to this observation by showing a higher prevalence of acute coronary syndromes in those patients with CMV-infected plaques. Our study also suggests a familial vulnerability to CMV replication in the coronary artery walls. PMID:22891128

Fazel, Mozhgan; Saadat, Seyed Hassan; Nasseri, Mohammad Hassan; Ghasemi, Mojtaba; Dabiri, Hossein; Aryan, Reza Safi; Esfahani, Ali Akbar; Ahmadi, Ali; Kazemi-Saleh, Davood; Kalantar-Motamed, Mohammad Hassan; Taheri, Saeed

2012-01-01

399

Impact of local vessel curvature on the circumferential plaque distribution in coronary arteries  

E-print Network

was derived from the 3­D borders of the lumen/plaque and media/adventitia interfaces. Within each frame as an electronic reprint with permission of SPIE. One print or electronic copy may be made for personal use only

Wahle, Andreas

400

Computerized assessment of motion-contaminated calcified plaques in cardiac multidetector CT  

SciTech Connect

An automated method for evaluating the image quality of calcified plaques with respect to motion artifacts in noncontrast-enhanced cardiac computed tomography (CT) images is introduced. This method involves using linear regression (LR) and artificial neural network (ANN) regression models for predicting two patient-specific, region-of-interest-specific, reconstruction-specific and temporal phase-specific image quality indices. The first is a plaque motion index, which is derived from the actual trajectory of the calcified plaque and is represented on a continuous scale. The second is an assessability index, which reflects the degree to which a calcified plaque is affected by motion artifacts, and is represented on an ordinal five-point scale. Two sets of assessability indices were provided independently by two radiologists experienced in evaluating cardiac CT images. Inputs for the regression models were selected from 12 features characterizing the dynamic, morphological, and intensity-based properties of the calcified plaques. Whereas LR-velocity (LR-V) used only a single feature (three-dimensional velocity), the LR-multiple (LR-M) and ANN regression models used the same subset of these 12 features selected through stepwise regression. The regression models were parameterized and evaluated using a database of simulated calcified plaque images from the dynamic NCAT phantom involving nine heart rate/multi-sector gating combinations and 40 cardiac phases covering two cardiac cycles. Six calcified plaques were used for the plaque motion indices and three calcified plaques were used for both sets of assessability indices. In one configuration, images from the second cardiac cycle were used for feature selection and regression model parameterization, whereas images from the first cardiac cycle were used for testing. With this configuration, repeated measures concordance correlation coefficients (CCCs) and associated 95% confidence intervals for the LR-V, LR-M, and ANN were 0.817 [0.785, 0.848], 0.894 [0.869, 0.916], and 0.917 [0.892, 0.936] for the plaque motion indices. For the two sets of assessability indices, CCC values for the ANN model were 0.843 [0.791, 0.877] and 0.793 [0.747, 0.828]. These two CCC values were statistically greater than the CCC value of 0.689 [0.648, 0.727], which was obtained by comparing the two sets of assessability indices with each other. These preliminary results suggest that the variabilities of assessability indices provided by regression models can lie within the variabilities of the indices assigned by independent observers. Thus, the potential exists for using regression models and assessability indices for determining optimal phases for cardiac CT image interpretation.

King, Martin; Giger, Maryellen L.; Suzuki, Kenji; Bardo, Dianna M. E.; Greenberg, Brent; Lan Li; Pan Xiaochuan [Department of Radiology, Committee on Medical Physics, University of Chicago, Chicago, Illinois 60637 (United States)

2007-12-15

401

Antioxidants attenuate atherosclerotic plaque development in a balloon-denuded and -radiated hypercholesterolemic rabbit  

SciTech Connect

Background: Oxidation of lipoproteins is considered to be a key contributor to atherogenesis. Antioxidants are potential antiatherogenic agents because they can inhibit lipoprotein oxidation. Radiation has been shown to increase oxidative stress leading to increased atherogenesis. This study is designed to test the potential of antioxidants to inhibit atherosclerotic plaque progression in balloon-denuded and -radiated rabbits. Methods and Results: Two groups of New Zealand white rabbits (n=36) were fed with 1% cholesterol diet (control diet) or with 1% cholesterol diet containing a mixture of various antioxidants for 1 week. Iliac arteries in all the animals were balloon denuded and continued to fed with 0.15% cholesterol diet or 0.15% cholesterol diet containing antioxidants (antioxidant diet). Four weeks after balloon denudation one iliac artery in 12 animals from each group was radiated and all the animals were continued to be fed with the same diet. Four weeks after radiation animals were sacrificed and morphometric analysis of iliac arteries (n=12) in nonradiated and radiated animals were performed. Plaque area (PA) in the rabbits that were fed with cholesterol diet is 0.2{+-}0.12 mm{sup 2}, and it is increased by 2.75-fold (P<.05) in the radiated arteries of animals fed with cholesterol diet. Plaque area in the animals fed with antioxidant diet is 50% less then the one in the animals fed with cholesterol diet. Similarly, plaque area in radiated arteries of the animals fed with antioxidant diet is 50% less then the animals fed with cholesterol diet. Conclusion: Antioxidants significantly attenuate atherosclerotic plaque progression in balloon-injured and -radiated hypercholesterolemic rabbits.

Leborgne, Laurent; Fournadjiev, Jana; Pakala, Rajbabu; Dilcher, Christian; Cheneau, Edouard; Wolfram, Roswitha; Hellinga, David; Seaborn, Rufus; O'Tio, Fermin; Waksman, Ron

2003-03-01