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1

Vulnerable Plaque  

MedlinePLUS

... plaque is formed in the following way. Fat droplets are absorbed by the artery, which causes the ... called macrophages and begin to soak up fat droplets. The fat-filled cells form a plaque with ...

2

Plaque Psoriasis  

MedlinePLUS

... Cycle Team NPF DIY Medical Professionals Donate Donate Psoriasis About Psoriasis Symptoms and Diagnosis Types of Psoriasis ... Kit Find Us Online YouTube Twitter Facebook Plaque Psoriasis Plaque psoriasis is the most common form of ...

3

Plaque regression and plaque stabilisation in cardiovascular diseases  

PubMed Central

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

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

2013-01-01

4

Effects of bacteriophage traits on plaque formation  

PubMed Central

Background The appearance of plaques on a bacterial lawn is one of the enduring imageries in modern day biology. The seeming simplicity of a plaque has invited many hypotheses and models in trying to describe and explain the details of its formation. However, until now, there has been no systematic experimental exploration on how different bacteriophage (phage) traits may influence the formation of a plaque. In this study, we constructed a series of isogenic ? phages that differ in their adsorption rate, lysis timing, or morphology so that we can determine the effects if these changes on three plaque properties: size, progeny productivity, and phage concentration within plaques. Results We found that the adsorption rate has a diminishing, but negative impact on all three plaque measurements. Interestingly, there exists a concave relationship between the lysis time and plaque size, resulting in an apparent optimal lysis time that maximizes the plaque size. Although suggestive in appearance, we did not detect a significant effect of lysis time on plaque productivity. Nonetheless, the combined effects of plaque size and productivity resulted in an apparent convex relationship between the lysis time and phage concentration within plaques. Lastly, we found that virion morphology also affected plaque size. We compared our results to the available models on plaque size and productivity. For the models in their current forms, a few of them can capture the qualitative aspects of our results, but not consistently in both plaque properties. Conclusions By using a collection of isogenic phage strains, we were able to investigate the effects of individual phage traits on plaque size, plaque productivity, and average phage concentration in a plaque while holding all other traits constant. The controlled nature of our study allowed us to test several model predictions on plaque size and plaque productivity. It seems that a more realistic theoretical approach to plaque formation is needed in order to capture the complex interaction between phage and its bacterium host in a spatially restricted environment. PMID:21827665

2011-01-01

5

Pioneer F Plaque Symbology  

NASA Technical Reports Server (NTRS)

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

1972-01-01

6

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

7

Vascular MR segmentation: wall and plaque  

Microsoft Academic Search

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

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

2003-01-01

8

Radiotracer imaging of atherosclerotic plaque biology.  

PubMed

Traditional imaging modalities used in the assessment of atherosclerotic plaque have focused on anatomic characteristics of size, location and luminal encroachment. The ability to identify plaques that are at risk for rupture, and thus may go on to cause clinical events, remains limited, however. By labeling tracer compounds capable of identifying important cellular or molecular processes involved in plaque vulnerability with radioactive isotopes, there is now potential for the noninvasive identification of vulnerable plaques. This article discusses several radiotracers that can report on high-risk plaque pathophysiology. PMID:19306774

Elkhawad, Maysoon; Rudd, James H F

2009-05-01

9

Ophthalmic zoster: mucous plaque keratitis.  

PubMed Central

Data taken from 1221 patients attending the Zoster Clinic of Moorfields Eye Hospital over the past 15 years were used to characterise the clinical appearance and behaviour of zoster mucous plaque keratitis (MPK). The typical greyish branching plaques are usually accompanied by a limbitis, stromal keratitis, or decrease in corneal sensation and are commonly associated with cataract, raised intraocular pressure, or corneal ulceration. MPK may begin at any time within two years of onset of the rash, but when it appears after three months there are more complications. Usually MPK settles within one month if appropriate treatment with topical steroids and acetylcysteine drops is given, but surgical intervention is sometimes required to control glaucoma or neuroparalytic keratitis or to remove cataracts. The results of surgery are surprisingly good. Images PMID:3499932

Marsh, R. J.; Cooper, M.

1987-01-01

10

Stickland reactions of dental plaque.  

PubMed Central

Dental plaque samples from monkeys (Macaca fascicularis) were shown to contain proline reduction activity in coupled Stickland reactions with other amino acids and also with certain end products of bacterial glucose metabolism. The unusually high concentration of bound and free proline in the oral environment may be of importance in both the production of base and in the removal of acid from the tooth surface after dietary carbohydrate ingestion. PMID:6618673

Curtis, M A; Kemp, C W; Robrish, S A; Bowen, W H

1983-01-01

11

Ceramides and sphingomyelinases in senile plaques.  

PubMed

The senile plaque is a hallmark lesion of Alzheimer disease (AD). We compared, without a priori, the lipidome of the senile plaques and of the adjacent plaque-free neuropil. The analysis by liquid chromatography coupled with electrospray ionization mass spectrometry revealed that laser microdissected senile plaques were enriched in saturated ceramides Cer(d18:1/18:0) and Cer(d18:1/20:0) by 33 and 78% respectively with respect to the surrounding neuropil. This accumulation of ceramides was not explained by their affinity for A? deposits: no interaction between ceramide-liposomes and A? fibrils was observed in vitro by surface plasmon resonance and fluorescent ceramide-liposomes showed no affinity for the senile plaques in AD brain tissue. Accumulation of ceramides could be, at least partially, the result of a local production by acid and neutral sphingomyelinases that we found to be present in the corona of the senile plaques. PMID:24486621

Panchal, Maï; Gaudin, Mathieu; Lazar, Adina N; Salvati, Elisa; Rivals, Isabelle; Ayciriex, Sophie; Dauphinot, Luce; Dargère, Delphine; Auzeil, Nicolas; Masserini, Massimo; Laprévote, Olivier; Duyckaerts, Charles

2014-05-01

12

Mechanisms of plaque formation and rupture.  

PubMed

Atherosclerosis causes clinical disease through luminal narrowing or by precipitating thrombi that obstruct blood flow to the heart (coronary heart disease), brain (ischemic stroke), or lower extremities (peripheral vascular disease). The most common of these manifestations is coronary heart disease, including stable angina pectoris and the acute coronary syndromes. Atherosclerosis is a lipoprotein-driven disease that leads to plaque formation at specific sites of the arterial tree through intimal inflammation, necrosis, fibrosis, and calcification. After decades of indolent progression, such plaques may suddenly cause life-threatening coronary thrombosis presenting as an acute coronary syndrome. Most often, the culprit morphology is plaque rupture with exposure of highly thrombogenic, red cell-rich necrotic core material. The permissive structural requirement for this to occur is an extremely thin fibrous cap, and thus, ruptures occur mainly among lesions defined as thin-cap fibroatheromas. Also common are thrombi forming on lesions without rupture (plaque erosion), most often on pathological intimal thickening or fibroatheromas. However, the mechanisms involved in plaque erosion remain largely unknown, although coronary spasm is suspected. The calcified nodule has been suggested as a rare cause of coronary thrombosis in highly calcified and tortious arteries in older individuals. To characterize the severity and prognosis of plaques, several terms are used. Plaque burden denotes the extent of disease, whereas plaque activity is an ambiguous term, which may refer to one of several processes that characterize progression. Plaque vulnerability describes the short-term risk of precipitating symptomatic thrombosis. In this review, we discuss mechanisms of atherosclerotic plaque initiation and progression; how plaques suddenly precipitate life-threatening thrombi; and the concepts of plaque burden, activity, and vulnerability. PMID:24902970

Bentzon, Jacob Fog; Otsuka, Fumiyuki; Virmani, Renu; Falk, Erling

2014-06-01

13

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

14

Macrophage heterogeneity in atherosclerotic plaques  

PubMed Central

Purpose of review The varied behaviour of macrophages and foam cells during atherosclerosis and its clinical sequelae prompt the question whether all these activities can be the property of a single cell population. Recent findings Subsets of monocytes with distinct patterns of surface markers and behaviours during inflammation have recently been characterized and shown to have complementary roles during progression of atherosclerosis. A variety of macrophage phenotypes derived from these monocyte subsets in response to mediators of innate and acquired immunity have also been found in plaques. Based on functional properties and genomic signatures, they may have different impacts on facets of plaque development, including fibrous cap and lipid core formation. Summary Monocyte and macrophage phenotypic diversity is important in atherogenesis. More work is needed to define consistent marker sets for the different foam cell phenotypes in experimental animals and humans. Cell tracking studies are needed to establish their relationship with monocyte subtypes. In addition, genetic and pharmacological manipulation of phenotypes will be useful to define their functions and exploit the resulting therapeutic potential. PMID:19741337

Johnson, Jason L.; Newby, Andrew C.

2010-01-01

15

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

16

Fibrin Deposition in Peyronie's Disease Plaque  

Microsoft Academic Search

PurposePeyronie's disease is a pathological fibrosis characterized by excessive deposition of collagen in the plaque. Although the etiology of Peyronie's disease is unknown, trauma has been hypothesized as the inciting event. In an effort to obtain more insight into the pathogenesis of Peyronie's disease plaque tissue was examined for collagen, elastic fiber, and fibrin content and distribution.

Kenneth D. Somers; Dawn M. Dawson

1997-01-01

17

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

18

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

PubMed

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

2014-07-01

19

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

20

The clinical value of histological femoral artery plaque analysis.  

E-print Network

??This thesis shows that the dissected femoral atherosclerotic plaque contains a predictive value for clinical outcome after femoral endarterectomy. Plaque histology analysis should be incorporated… (more)

Derksen, W.J.M.

2011-01-01

21

Biomechanical factors and macrophages in plaque stability.  

PubMed

Thin-cap fibroatheromas (TCFAs) or vulnerable atherosclerotic plaques are considered a high-risk phenotype for acute cardiovascular events. TCFAs are identified by a thin rupture-prone fibrous cap, a large necrotic core, and a high content of leucocytes. Atherogenesis is dependent upon complex patterns of blood flow. Slow-flowing blood imposing low shear stress on the arterial wall up-regulates inflammatory signalling in endothelial cells and leucocytes, and modulates microRNAs to promote inflammation and monocyte recruitment. Hence, low shear stress is believed to promote conditions conducive to vulnerable plaque development. In this review, we explore how biomechanical factors modulate macrophage phenotype and plaque stability. PMID:23687352

Seneviratne, Anusha; Hulsmans, Maarten; Holvoet, Paul; Monaco, Claudia

2013-07-15

22

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

23

Role of inflammation and metalloproteinases in plaque disruption and thrombosis.  

PubMed

Numerous pathological, clinical, angiographic and angioscopic studies have demonstrated that acute coronary syndromes (unstable angina, acute myocardial infarction and ischemic sudden death) are most frequently the consequence of plaque disruption (plaque rupture or superficial plaque erosion) and consequent coronary thrombosis. Several serial angiographic studies have demonstrated that nearly 60-70% of acute coronary syndromes evolve from mildly to moderately obstructive atherosclerotic plaques. Coronary plaque disruption appears to be a function of both the composition of the plaque (plaque vulnerability ) as well as extrinsic triggers that may precipitate plaque disruption in a vulnerable plaque. Vulnerability for plaque disruption appears to be largely determined by the size of the lipid-rich atheromatous core, the thickness of the fibrous cap covering the core, and the presence of ongoing inflammation within and underneath the cap. Inflammatory cells may play a critical role in plaque disruption through the elaboration of matrix degrading metalloproteinases or MMPs (collagenases, gelatinases, stromelysins and matrilysin) and by inhibition of function and survival of matrix-synthesizing smooth muscle cells. Inflammatory cells may also play a critical role in triggering thrombosis following plaque disruption through the tissue factor pathway. In addition, stresses resulting from hemodynamic and mechanical forces may precipitate plaque disruption, particularly at points where the fibrous cap is weakest, such as at its shoulders. The degree of thrombosis following plaque disruption is determined by the thrombogenicity of the disrupted plaque, disturbed local rheology and systemic thrombotic-thrombolytic milieu. Surges in sympathetic activity provoked by sudden vigorous exercise, emotional stress -- including anger, or cold weather, may also trigger plaque disruption. These observations have led to the concept of plaque stabilization as a new clinical strategy for the prevention of acute coronary syndromes. Plaque stabilization can be achieved through pharmacologic and lifestyle-modifying interventions that reduce vulnerability to plaque disruption by altering plaque composition and/or inflammatory activity within the plaque. PMID:9892512

Shah, P K

1998-01-01

24

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

25

CONFIRMED VIRUSES VERSUS UNCONFIRMED PLAQUES IN SEWAGE  

EPA Science Inventory

Ninety-two treated and untreated sewage samples from seven wastewater treatment plants in Chicago, Illinois, Memphis, Tennessee, and Cincinnati, Ohio were examined for their virus content. Concentrated and unconcentrated samples were plaque assayed in five different cell culture ...

26

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

27

Carotid Plaque Age Is a Feature of Plaque Stability Inversely Related to Levels of Plasma Insulin  

PubMed Central

Background The stability of atherosclerotic plaques determines the risk for rupture, which may lead to thrombus formation and potentially severe clinical complications such as myocardial infarction and stroke. Although the rate of plaque formation may be important for plaque stability, this process is not well understood. We took advantage of the atmospheric 14C-declination curve (a result of the atomic bomb tests in the 1950s and 1960s) to determine the average biological age of carotid plaques. Methodology/Principal Finding The cores of carotid plaques were dissected from 29 well-characterized, symptomatic patients with carotid stenosis and analyzed for 14C content by accelerator mass spectrometry. The average plaque age (i.e. formation time) was 9.6±3.3 years. All but two plaques had formed within 5–15 years before surgery. Plaque age was not associated with the chronological ages of the patients but was inversely related to plasma insulin levels (p?=?0.0014). Most plaques were echo-lucent rather than echo-rich (2.24±0.97, range 1–5). However, plaques in the lowest tercile of plaque age (most recently formed) were characterized by further instability with a higher content of lipids and macrophages (67.8±12.4 vs. 50.4±6.2, p?=?0.00005; 57.6±26.1 vs. 39.8±25.7, p<0.0005, respectively), less collagen (45.3±6.1 vs. 51.1±9.8, p<0.05), and fewer smooth muscle cells (130±31 vs. 141±21, p<0.05) than plaques in the highest tercile. Microarray analysis of plaques in the lowest tercile also showed increased activity of genes involved in immune responses and oxidative phosphorylation. Conclusions/Significance Our results show, for the first time, that plaque age, as judge by relative incorporation of 14C, can improve our understanding of carotid plaque stability and therefore risk for clinical complications. Our results also suggest that levels of plasma insulin might be involved in determining carotid plaque age. PMID:21490968

Hägg, Sara; Salehpour, Mehran; Noori, Peri; Lundström, Jesper; Possnert, Göran; Takolander, Rabbe; Konrad, Peter; Rosfors, Stefan; Ruusalepp, Arno; Skogsberg, Josefin; Tegnér, Jesper; Björkegren, Johan

2011-01-01

28

Imaging of the carotid artery vulnerable plaque.  

PubMed

Atherosclerosis involving the carotid arteries has a high prevalence in the population worldwide. This condition is significant because accidents of the carotid artery plaque are associated with the development of cerebrovascular events. For this reason, carotid atherosclerotic disease needs to be diagnosed and those determinants that are associated to an increased risk of stroke need to be identified. The degree of stenosis typically has been considered the parameter of choice to determine the therapeutical approach, but several recently published investigations have demonstrated that the degree of luminal stenosis is only an indirect indicator of the atherosclerotic process and that direct assessment of the plaque structure and composition may be key to predict the development of future cerebrovascular ischemic events. The concept of "vulnerable plaque" was born, referring to those plaque's parameters that concur to the instability of the plaque making it more prone to the rupture and distal embolization. The purpose of this review is to describe the imaging characteristics of "vulnerable carotid plaques." PMID:23912494

Saba, Luca; Anzidei, Michele; Marincola, Beatrice Cavallo; Piga, Mario; Raz, Eytan; Bassareo, Pier Paolo; Napoli, Alessandro; Mannelli, Lorenzo; Catalano, Carlo; Wintermark, Max

2014-06-01

29

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

SciTech Connect

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

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

2009-01-01

30

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

PubMed Central

Background Due to the limited number of experimental studies that mechanically characterise human atherosclerotic plaque tissue from the femoral arteries, a recent trend has emerged in current literature whereby one set of material data based on aortic plaque tissue is employed to numerically represent diseased femoral artery tissue. This study aims to generate novel vessel-appropriate material models for femoral plaque tissue and assess the influence of using material models based on experimental data generated from aortic plaque testing to represent diseased femoral arterial tissue. Methods Novel material models based on experimental data generated from testing of atherosclerotic femoral artery tissue are developed and a computational analysis of the revascularisation of a quarter model idealised diseased femoral artery from a 90% diameter stenosis to a 10% diameter stenosis is performed using these novel material models. The simulation is also performed using material models based on experimental data obtained from aortic plaque testing in order to examine the effect of employing vessel appropriate material models versus those currently employed in literature to represent femoral plaque tissue. Results Simulations that employ material models based on atherosclerotic aortic tissue exhibit much higher maximum principal stresses within the plaque than simulations that employ material models based on atherosclerotic femoral tissue. Specifically, employing a material model based on calcified aortic tissue, instead of one based on heavily calcified femoral tissue, to represent diseased femoral arterial vessels results in a 487 fold increase in maximum principal stress within the plaque at a depth of 0.8 mm from the lumen. Conclusions Large differences are induced on numerical results as a consequence of employing material models based on aortic plaque, in place of material models based on femoral plaque, to represent a diseased femoral vessel. Due to these large discrepancies, future studies should seek to employ vessel-appropriate material models to simulate the response of diseased femoral tissue in order to obtain the most accurate numerical results. PMID:25602515

2015-01-01

31

Functional expression of dental plaque microbiota.  

PubMed

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

32

Growth of Necrotic Cores in Vulnerable Plaque  

NASA Astrophysics Data System (ADS)

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

Fok, Pak-Wing

2011-03-01

33

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

34

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

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

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

35

Estimation of nonlinear mechanical properties of atherosclerotic plaques  

E-print Network

A numerical method has been developed to estimate the mechanical properties of atherosclerotic plaques by combining genetic algorithm with finite element methods. Plaque images derived from optical coherence tomography ...

Zhu, Ting F. (Ting Fredrick)

2005-01-01

36

Treating cardiovascular atherosclerotic plaques with Tongmaijiangzhi (TMJZ) capsule.  

PubMed

Atherosclerotic plaques can cause serious syndromes and mortality. Cholesterol accumulation in the plaques can disrupt the arterial flow, with lumen narrowing and stenosis, which contributes to heart attack and sudden cardiac death. The pharmacological treatment to atherosclerotic plaques can be anti-hypertensives, anti-cholesterol, and cleaning of the existed plaques. This work examined the effects of pharmacological Tongmaijiangzhi (TMJZ) capsule on atherosclerotic plaques. The radiological findings of the atherosclerotic plaques of 107 patients receiving TMJZ treatment were analyzed. We found that the TMJZ administration decreases plaque volume and alters the composition in a relatively short period, showing highly promising effects. TMJZ treatment is able to remove the existed atherosclerotic plaques with no side effects observed. PMID:24311866

Ren, Hong-Qiang; Zhao, Li; Zhang, Zhong Shuang; Wang, Zhong; Wang, Li; Duan, Jun Cang; Li, Li; Zhai, Zhi Hong; Qu, De Tao; Huang, Hui

2013-01-01

37

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

38

Red plaque on a high school wrestler.  

PubMed

A 15-year-old freshman on a nationally ranked high school wrestling team had a 1-week history of a pruritic plaque on his left arm. He had no history of atopic dermatitis or a similar lesion. He had been treating the lesion with over-the-counter 1% hydrocortisone cream for 7 days without resolution. PMID:20086564

Adams, B B

2001-02-01

39

Shear stress in atherosclerotic plaque determination.  

PubMed

Atherosclerosis initiates at predictable focal sites near arterial branches and curves, where blood flow is disturbed and shear stress is complex. Endothelial shear stress is the tangential stress derived from the friction of the flowing blood on the endothelial surface of the arterial wall. It is a key factor in modulating endothelial cell gene expression and vascular development and remodeling. Increasing evidences suggest that shear stress patterns have a strong relationship with atherosclerotic features. Moreover, variations in the local artery geometry during atherogenesis further modify flow shear stress characteristics, which contribute to the rupture site at the plaque upstream. In this study, we summarize the mechanistic evidences that associate shear stress patterns with determined atherosclerotic plaque features. An enhanced understanding of the relationship and pathophysiological function of shear stress patterns in atherosclerotic plaque features is essential, which may provide early prediction of clinical risk and guide individualized treatment strategies. In the current review, we analyzed the function of shear stress on the determination of atherosclerotic lesion and provided an update on the mechanotransduction of shear stress, gene expression regulation, and atherosclerotic plaque development and rupture. PMID:25165867

Li, Xiaohong; Yang, Qin; Wang, Zuo; Wei, Dangheng

2014-12-01

40

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

41

Microanalysis of Alzheimer disease NFT and plaques  

Microsoft Academic Search

Electron probe energy dispersive microanalysis of isolated andin situ neurofibrillary tangles (NFT) and neuritic (senile) plaque cores have been done to investigate the levels of Al, Si, Ca and Fe in the leading lesions of Alzheimer disease neuropathology. Varying levels of Si and Al, and to a lesser extent Ca, have been co-localized in about one half of the NFT

R. C. Moretz; K. Iqbal; H. M. Wisniewski

1990-01-01

42

Lipidome of Atherosclerotic Plaques from Hypercholesterolemic Rabbits  

PubMed Central

The cellular, macromolecular and neutral lipid composition of the atherosclerotic plaque has been extensively characterized. However, a comprehensive lipidomic analysis of the major lipid classes within atherosclerotic lesions has not been reported. The objective of this study was to produce a detailed framework of the lipids that comprise the atherosclerotic lesion of a widely used pre-clinical model of plaque progression. Male New Zealand White rabbits were administered regular chow supplemented with 0.5% cholesterol (HC) for 12 weeks to induce hypercholesterolemia and atherosclerosis. Our lipidomic analyses of plaques isolated from rabbits fed the HC diet, using ultra-performance liquid chromatography (UPLC) and high-resolution mass spectrometry, detected most of the major lipid classes including: Cholesteryl esters, triacylglycerols, phosphatidylcholines, sphingomyelins, diacylglycerols, fatty acids, phosphatidylserines, lysophosphatidylcholines, ceramides, phosphatidylglycerols, phosphatidylinositols and phosphatidylethanolamines. Given that cholesteryl esters, triacylglycerols and phosphatidylcholines comprise greater than 75% of total plasma lipids, we directed particular attention towards the qualitative and quantitative assessment of the fatty acid composition of these lipids. We additionally found that sphingomyelins were relatively abundant lipid class within lesions, and compared the abundance of sphingomyelins to their precursor phosphatidylcholines. The studies presented here are the first approach to a comprehensive characterization of the atherosclerotic plaque lipidome. PMID:25517033

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

2014-01-01

43

Linear milia en plaque on the forearm.  

PubMed

A 64-year-old man presented with asymptomatic eruption on his right forearm and the dorsum of the hand present for 2 weeks. There was no history of trauma, prolonged sun exposure, or application of or contact with any substance prior to the development of lesions. He was a known hypertensive and diabetic and was taking treatment for these conditions. The rest of his history was noncontributory. On examination, multiple grouped tiny white papules were found on both normal skin and on the erythematous plaque. These papules were of almost uniform size (2-4 mm) and were notable for absence of umbilication. The erythematous plaque was roughly 15 cm in length and was extending along the ulnar border of forearm and dorsum of hand in a linear pattern (Figure 1). The surface temperature of the plaque appeared similar to the surrounding area, and the surface was studded with multiple tiny white papules. There were no lesions suggestive of chronic actinic damage in the surrounding area. The papules revealed solid whitish material on expression with a needle. The rest of the mucocutaneous examination was noncontributory. Based on clinical presentation, a diagnosis of linear milia en plaque was made. PMID:25335356

Kumar, Piyush; Gharami, Ramesh Chandra

2014-01-01

44

Lipidome of atherosclerotic plaques from hypercholesterolemic rabbits.  

PubMed

The cellular, macromolecular and neutral lipid composition of the atherosclerotic plaque has been extensively characterized. However, a comprehensive lipidomic analysis of the major lipid classes within atherosclerotic lesions has not been reported. The objective of this study was to produce a detailed framework of the lipids that comprise the atherosclerotic lesion of a widely used pre-clinical model of plaque progression. Male New Zealand White rabbits were administered regular chow supplemented with 0.5% cholesterol (HC) for 12 weeks to induce hypercholesterolemia and atherosclerosis. Our lipidomic analyses of plaques isolated from rabbits fed the HC diet, using ultra-performance liquid chromatography (UPLC) and high-resolution mass spectrometry, detected most of the major lipid classes including: Cholesteryl esters, triacylglycerols, phosphatidylcholines, sphingomyelins, diacylglycerols, fatty acids, phosphatidylserines, lysophosphatidylcholines, ceramides, phosphatidylglycerols, phosphatidylinositols and phosphatidylethanolamines. Given that cholesteryl esters, triacylglycerols and phosphatidylcholines comprise greater than 75% of total plasma lipids, we directed particular attention towards the qualitative and quantitative assessment of the fatty acid composition of these lipids. We additionally found that sphingomyelins were relatively abundant lipid class within lesions, and compared the abundance of sphingomyelins to their precursor phosphatidylcholines. The studies presented here are the first approach to a comprehensive characterization of the atherosclerotic plaque lipidome. PMID:25517033

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

2014-01-01

45

Biomechanics of Plaque Rupture: Progress, Problems, and New Frontiers  

Microsoft Academic Search

Plaque rupture has become identified as a critical step in the evolution of arterial plaques, especially as clinically significant events occur in critical arteries. It has become common in the past dozen years or so to consider which plaques are vulnerable, even though not yet ruptured. Thrombotic events have remained significant, but in a context where they are seen as

Peter D. Richardson

2002-01-01

46

IVUS-based Histology of Atherosclerotic plaques: Improving Longitudinal Resolution  

E-print Network

IVUS-based Histology of Atherosclerotic plaques: Improving Longitudinal Resolution Arash Takia ABSTRACT Although Virtual Histology (VH) is the in-vivo gold standard for atherosclerosis plaque is the Virtual Histology (VH).3 VH provides a colored coded plaque characterization image by analyzing

Yanikoglu, Berrin

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

Artery buckling affects the mechanical stress in atherosclerotic plaques  

PubMed Central

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

2015-01-01

49

In Vivo MRI Atherosclerotic Plaque Characterization Using Magnetic Susceptibility Distinguishes Symptom-Producing Plaques  

PubMed Central

Objectives We investigated iron's role in atherosclerosis and plaque instability with a novel approach to in vivo atherosclerotic plaque characterization using noninvasive, noncontrast magnetic resonance-based T2* measurement. We validated this approach using ex vivo plaque analyses to establish that T2* reflects intraplaque iron composition. Background Iron catalyzes free radical production, a key step for lipid peroxidation and atherosclerosis development. The parameter T2* measures tissue magnetic susceptibility, historically has been used to quantify hepatic and myocardial iron. To date, T2* measurement has not been previously developed for in vivo plaque characterization in patients with atherosclerosis. Methods Thirty-nine patients referred for carotid endarterectomy were prospectively enrolled to undergo preoperative carotid MRI and postoperative analysis of the explanted plaque. Clinical history of any symptoms attributable to each carotid lesion was recorded. Results MRI could not be completed in 4 subjects due to claustrophobia, and three patients scanned prior to the use of a neck stabilizer had motion artifact precluding quantification. In the remaining subjects, symptomatic compared to asymptomatic patients had significantly lower plaque T2* values (20.0±1.8 vs. 34.4±2.7 ms, respectively, p<0.001). Analytical methods demonstrated similar total iron (138.6±36.5 vs. 165.8±48.3 mg/kg, p=NS) but less low-molecular weight Fe(III) (7.3±3.8 vs. 17.7±4.0 nmol/mg, p<0.05) in the explanted plaques of symptomatic versus asymptomatic patients, respectively, consistent with a shift in iron from Fe(III) to higher amounts of T2*-shortening forms of iron. Mass spectroscopy also showed significantly lower calcium (37.5±10.8 vs. 123.6±19.3 g/kg, p<0.01) and higher copper (3.2±0.5 vs. 1.7±0.1 mg/kg, p<0.01) in plaques from symptomatic patients. Conclusions In vivo measurement of intraplaque T2* using MRI is feasible and reproducible, and distinguishes symptom-producing from non-symptom producing plaques in patients with carotid artery atherosclerosis. Symptom-producing plaques demonstrated characteristic changes in iron forms by ex vivo analysis, supporting the dynamic presence of iron in the microenvironment of atherosclerotic plaque. PMID:19356405

Raman, Subha V.; Winner, Marshall W.; Tran, Tam; Velayutham, Murugesan; Simonetti, Orlando P.; Baker, Peter B.; Olesik, John; McCarthy, Beth; Ferketich, Amy K.; Zweier, Jay L.

2009-01-01

50

Therapeutic strategies to deplete macrophages in atherosclerotic plaques  

PubMed Central

Macrophages can be found in all stages of atherosclerosis and are major contributors of atherosclerotic plaque development, progression and destabilization. Continuous recruitment of monocytes drives this chronic inflammatory disease, which can be intervened by several strategies: reducing the inflammatory stimulus by lowering circulating lipids and promoting cholesterol efflux from plaque, direct and indirect targeting of adhesion molecules and chemokines involved in monocyte adhesion and transmigration and inducing macrophage death in atherosclerotic plaques in combination with anti-inflammatory drugs. This review discusses the outlined strategies to deplete macrophages from atherosclerotic plaques to promote plaque stabilization. PMID:22309283

De Meyer, Inge; Martinet, Wim; De Meyer, Guido R. Y.

2012-01-01

51

Facts and artefacts in research on human dental plaque fluid.  

PubMed

In 1966, Jenkins suggested that the plaque fluid environment was likely to have higher concentrations of extracellular solutes than was apparent from analyses of total plaque concentrations. Early work on plaque fluid confirmed this contention, but some artefact was also generated by the prolonged centrifugation used for separation. The solute concentrations in plaque fluid mostly exceed those in saliva or crevicular fluid. Thus, the environmental conditions are distinctly different from those based on the assumption that saliva readily permeates films of dental plaque. In contrast, the presence of serum proteins suggests a crevicular input to plaque fluid. These data suggest that exchange between dental plaque and its environment is apparently restricted. Diffusion rates measured in dental plaque by different methods do not agree on how restricted it is. However, measuring diffusion in plaque introduces artefacts in packing density, a major determinant of the diffusion rate. The conditions used for collection and analysis have been reported to produce artefactual changes in plaque fluid potassium, a predominantly intracellular ion. Measurements of predominantly extracellular ions, such as calcium, are no less prone to artefact, whether based on ion-selective electrodes or on total calcium. We have much to learn about the fluid environment of the teeth and about dynamic changes in plaque fluid composition and properties during perturbations. Such information can give insights into pathological processes such as tooth demineralization and dental caries, calculus formation, and gingival inflammation. PMID:2191981

Tatevossian, A

1990-06-01

52

Intradural extramedullary tuberculoma mimicking en plaque meningioma.  

PubMed

In this paper we report an 18 year old woman with an intradural extramedullary tuberculoma mimicking en plaque meningioma located in the thoracic region. The patient was operated via thoracic laminoplasty and tumor was totally resected. On the follow-up examination the magnetic resonance imaging demonstrated the total excision of the tumor. Here we describe a case of intradural extramedullary tuberculoma of the spinal cord as a complication of tuberculosis meningitis in a previously healthy young female. PMID:19439860

Ozek, Erdinc; Iplkcioglu, A Celal; Erdal, Mustafa

2009-01-01

53

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

54

Microwave plaque thermoradiotherapy for choroidal melanoma.  

PubMed Central

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

Finger, P. T.

1992-01-01

55

Ghrelin receptor deficiency aggravates atherosclerotic plaque instability and vascular inflammation.  

PubMed

Ghrelin has been found to be associated with anti-inflammatory effects, inhibition of atherosclerotic plaque formation, and plaque stability in the cardiovascular system. We investigated whether ghrelin affected atherosclerotic plaque and inflammation found in atherosclerosis. We crossed ghrelin receptor knock out mice (growth hormone secretagogue receptor (GHSR)-/-) and low-density lipoprotein receptor-null (low-density lipoprotein receptor (LDLR)-/-) mice. In this model, atherosclerotic lesions were promoted by administering a high-fat, high-cholesterol, Western-type diet for 18 weeks. Serum lipid levels, atherosclerotic plaque on the aortic arches, and expression of intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), T cells, macrophages, and smooth muscle cells of atherosclerotic plaque were observed. Although serum lipid levels and atherosclerotic plaque in aortic arches were not significantly different between GHSR+/+/LDLR-/- and GHSR -/-LDLR-/- mice, ICAM-1 and VCAM-1 protein expression in atherosclerotic plaques were increased in GHSR -/-LDLR-/- mice compared with GHSR+/+/LDLR-/- mice. T cells and macrophages were increased, while smooth muscle cells of atherosclerotic plaques were less in GHSR -/-LDLR-/- mice than that in GHSR+/+/LDLR-/- mice. In conclusion, ghrelin receptor deficiency aggravates atherosclerotic plaque instability and vascular inflammation but not the surface area of atherosclerotic plaque. This information will provide novel avenues for the treatment of patients with atherosclerosis.  PMID:25553467

Zhang, Min; Qu, Xinkai; Yuan, Fang; Yang, Yiqing; Xu, Lei; Dai, Jinjie; Wang, Weigang; Fei, Jian; Hou, Xumin; Fang, Weiyi

2015-01-01

56

Intravascular probe for detection of vulnerable plaque  

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

57

Bacterial Diversity in Human Subgingival Plaque  

PubMed Central

The purpose of this study was to determine the bacterial diversity in the human subgingival plaque by using culture-independent molecular methods as part of an ongoing effort to obtain full 16S rRNA sequences for all cultivable and not-yet-cultivated species of human oral bacteria. Subgingival plaque was analyzed from healthy subjects and subjects with refractory periodontitis, adult periodontitis, human immunodeficiency virus periodontitis, and acute necrotizing ulcerative gingivitis. 16S ribosomal DNA (rDNA) bacterial genes from DNA isolated from subgingival plaque samples were PCR amplified with all-bacterial or selective primers and cloned into Escherichia coli. The sequences of cloned 16S rDNA inserts were used to determine species identity or closest relatives by comparison with sequences of known species. A total of 2,522 clones were analyzed. Nearly complete sequences of approximately 1,500 bases were obtained for putative new species. About 60% of the clones fell into 132 known species, 70 of which were identified from multiple subjects. About 40% of the clones were novel phylotypes. Of the 215 novel phylotypes, 75 were identified from multiple subjects. Known putative periodontal pathogens such as Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola were identified from multiple subjects, but typically as a minor component of the plaque as seen in cultivable studies. Several phylotypes fell into two recently described phyla previously associated with extreme natural environments, for which there are no cultivable species. A number of species or phylotypes were found only in subjects with disease, and a few were found only in healthy subjects. The organisms identified only from diseased sites deserve further study as potential pathogens. Based on the sequence data in this study, the predominant subgingival microbial community consisted of 347 species or phylotypes that fall into 9 bacterial phyla. Based on the 347 species seen in our sample of 2,522 clones, we estimate that there are 68 additional unseen species, for a total estimate of 415 species in the subgingival plaque. When organisms found on other oral surfaces such as the cheek, tongue, and teeth are added to this number, the best estimate of the total species diversity in the oral cavity is approximately 500 species, as previously proposed. PMID:11371542

Paster, Bruce J.; Boches, Susan K.; Galvin, Jamie L.; Ericson, Rebecca E.; Lau, Carol N.; Levanos, Valerie A.; Sahasrabudhe, Ashish; Dewhirst, Floyd E.

2001-01-01

58

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

SciTech Connect

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

Vogel, G.L.; Carey, C.M.; Chow, L.C.; Tatevossian, A. (American Dental Association Health Foundation, Gaithersburg, MD (USA))

1990-06-01

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

Multimodality imaging of carotid atherosclerotic plaque: Going beyond stenosis  

PubMed Central

Apart from the degree of stenosis, the morphology of carotid atherosclerotic plaques and presence of neovascularization are important factors that may help to evaluate the risk and ‘vulnerability’ of plaques and may also influence the choice of treatment. In this article, we aim to describe the techniques and imaging findings on CTA, high resolution MRI and contrast enhanced ultrasound in the evaluation of carotid atherosclerotic plaques. We also discuss a few representative cases from our institute with the related clinical implications. PMID:23986615

Hingwala, Divyata; Kesavadas, Chandrasekharan; Sylaja, Padmavathy N; Thomas, Bejoy; Kapilamoorthy, Tirur Raman

2013-01-01

61

Palladium103 versus iodine-125 for ophthalmic plaque radiotherapy  

Microsoft Academic Search

A dosimetry study compared the use of I-125 vs. Pd-103 radioactive seeds for ophthalmic plaque brachytherapy. Pd-103 seeds in ophthalmic plaques were used to treat 15 patients with intraocular malignant melanoma. Computer-aided simulations were performed to evaluate the intraocular dose distribution of I-125 versus Pd-103 ophthalmic plaques (delivering equivalent apex doses). Seven target points were selected. Starting at the outer

Paul T. Finger; Dongfeng Lu; Alfonso Buffa; Daniels Deblasio; Jay L. Bosworth

1993-01-01

62

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.

63

DETAIL OF PLAQUE WITH ADDITIONAL DESIGN AND CONSTRUCTION INFORMATION, SOUTHEAST ...  

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

DETAIL OF PLAQUE WITH ADDITIONAL DESIGN AND CONSTRUCTION INFORMATION, SOUTHEAST ABUTMENT - Connecticut Avenue Bridge, Spans Rock Creek & Potomac Parkway at Connecticut Avenue, Washington, District of Columbia, DC

64

Nature or The Natural Evolution of Plaque: What Matters?  

PubMed Central

ABSTRACT Progression to major acute cardiovascular events often is triggered by an atherosclerotic plaque complicated by rupture or erosion, namely the vulnerable plaque. Early and secure identification of these plaques would allow the development of individualized therapeutic and pharmacological strategies, applied in a timely manner. Imaging methods have a huge potential in detecting and monitoring the evolution of vulnerable plaque. Even though there are multiple invasive and noninvasive techniques, clinical application is for now a matter of choosing the relevant imaging feature for the prognosis, the methodo­logy of study and the target population. PMID:24790659

AURSULESEI, Viviana

2013-01-01

65

Non-invasive detection of vulnerable coronary plaque  

PubMed Central

Critical coronary stenoses have been shown to contribute to only a minority of acute coronary syndromes and sudden cardiac death. Autopsy studies have identified a subgroup of high-risk patients with disrupted vulnerable plaque and modest stenosis. Consequently, a clinical need exists to develop methods to identify these plaques prospectively before disruption and clinical expression of disease. Recent advances in invasive and non-invasive imaging techniques have shown the potential to identify these high-risk plaques. Non-invasive imaging with magnetic resonance imaging, computed tomography and positron emission tomography holds the potential to differentiate between low- and high-risk plaques. There have been significant technological advances in non-invasive imaging modalities, and the aim is to achieve a diagnostic sensitivity for these technologies similar to that of the invasive modalities. Molecular imaging with the use of novel targeted nanoparticles may help in detecting high-risk plaques that will ultimately cause acute myocardial infarction. Moreover, nanoparticle-based imaging may even provide non-invasive treatments for these plaques. However, at present none of these imaging modalities are able to detect vulnerable plaque nor have they been shown to definitively predict outcome. Further trials are needed to provide more information regarding the natural history of high-risk but non-flow-limiting plaque to establish patient specific targeted therapy and to refine plaque stabilizing strategies in the future. PMID:21860703

Sharif, Faisal; Lohan, Derek G; Wijns, William

2011-01-01

66

Comparison of Methods for Monitoring Changes in the pH of Human Dental Plaque  

Microsoft Academic Search

Changes in human dental plaque pH can be used to obtain estimates of the acidogenic potential of ingested foods. The presence of acid in plaque is influenced by a large number of host, microbial, and substrate factors. Several useful methods have been developed for monitoring changes in plaque pH. Plaque sampling involves repeated removal of small samples of plaque from

C. F. Schachtele; M. E. Jensen

1982-01-01

67

Congenital Milia En Plaque on Scalp  

PubMed Central

Milia en plaque is a rare disease entity characterized by confluence of multiple keratin-filled cysts resulting from the obstruction of hair follicle without any preceding primary dermatosis. Fewer than 40 cases have been reported so far in dermatological literature, and most cases are described to occur in adults and in the peri-auricular area. We describe a case of congenital MEP on scalp of a five-year-old boy with a blaschkoid extension into posterior nuchal area. This case report claims its uniqueness because of the unusual site and congenital presentation. PMID:25657433

Ghosh, Sangita; Sangal, Shikha

2015-01-01

68

Intradural extramedullary tuberculoma mimicking en plaque meningioma.  

PubMed

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

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

2010-12-01

69

Intradural Extramedullary Tuberculoma Mimicking En Plaque Meningioma  

PubMed Central

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

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

2010-01-01

70

Congenital milia en plaque on scalp.  

PubMed

Milia en plaque is a rare disease entity characterized by confluence of multiple keratin-filled cysts resulting from the obstruction of hair follicle without any preceding primary dermatosis. Fewer than 40 cases have been reported so far in dermatological literature, and most cases are described to occur in adults and in the peri-auricular area. We describe a case of congenital MEP on scalp of a five-year-old boy with a blaschkoid extension into posterior nuchal area. This case report claims its uniqueness because of the unusual site and congenital presentation. PMID:25657433

Ghosh, Sangita; Sangal, Shikha

2015-01-01

71

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

72

Intravital imaging of amyloid plaques in a transgenic mouse model using optical-resolution  

E-print Network

Intravital imaging of amyloid plaques in a transgenic mouse model using optical imaging of amyloid plaques in an Alzheimer's disease mouse model. Validation using conventional-dimensional morphology of amyloid plaques and the surrounding microvasculature are imaged simultaneously through

Wang, Lihong

73

RTN\\/Nogo in forming Alzheimer's neuritic plaques  

Microsoft Academic Search

One of the pathological hallmarks in brains of patients with Alzheimer's disease (AD) is the presence of neuritic plaques, in which amyloid deposits are surrounded by reactive gliosis and dystrophic neurites. Within neuritic plaques, reticulon 3 (RTN3), a homolog of Nogo protein, appears to regulate the formation of both amyloid deposition via negative modulation of BACE1 activity and dystrophic neurites

Marguerite Prior; Qi Shi; Xiangyou Hu; Wanxia He; Allan Levey; Riqiang Yan

2010-01-01

74

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

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

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

75

Computational Fluid Dynamics Simulations of Hemodynamics in Plaque Erosion  

PubMed Central

Purpose We investigated whether local hemodynamics were associated with sites of plaque erosion and hypothesized that patients with plaque erosion have locally elevated WSS magnitude in regions where erosion has occurred. Methods We generated 3D, patient-specific models of coronary arteries from biplane angiographic images in 3 human patients with plaque erosion diagnosed by optical coherence tomography (OCT). Using computational fluid dynamics, we simulated pulsatile blood flow and calculated both wall shear stress (WSS) and oscillatory shear index (OSI). We also investigated anatomic features of plaque erosion sites by examining branching and local curvature in x-ray angiograms of barium-perfused autopsy hearts. Results Neither high nor low magnitudes of mean WSS were associated with sites of plaque erosion. OSI and local curvature were also not associated with erosion. Anatomically, 8 of 13 hearts had a nearby bifurcation upstream of the site of plaque erosion. Conclusions This study provides preliminary evidence that neither hemodynamics nor anatomy are predictors of plaque erosion, based upon a very unique dataset. Our sample sizes are small, but this dataset suggests that high magnitudes of wall shear stress, one potential mechanism for inducing plaque erosion, are not necessary for erosion to occur. PMID:24223678

Campbell, Ian C.; Timmins, Lucas H.; Giddens, Don P.; Virmani, Renu; Veneziani, Alessandro; Rab, S. Tanveer; Samady, Habib; McDaniel, Michael C.; Finn, Aloke V.; Taylor, W. Robert; Oshinski, John N.

2013-01-01

76

Oxysterols and symptomatic versus asymptomatic human atherosclerotic plaque.  

PubMed

Atherosclerosis is the most common cause of mortality in the Western world, contributing to about 50% of all deaths. Atherosclerosis is characterized by deposition of lipids onto the coronary or carotid arterial wall and formation of an atherosclerotic plaque. Atherosclerotic plaques are categorized into two groups: symptomatic and asymptomatic. The symptomatic plaques tend to be unstable and prone to rupture, and are associated with an increase in ischemic events. Oxysterols, products of cholesterol oxidation, are cytotoxic materials. Their level and type may be associated with plaque formation, development and stability. Oxysterols stimulate the formation of foam cells, advance atherosclerotic plaque progression, and contribute to plaque vulnerability and instability due to their cytotoxicity and their ability to induce cell apoptosis. Studies indicate that plasma 7?-OH CH level can be used as a biomarker for detecting carotid and coronary artery disease. Further clinical studies are needed to evaluate the potential of oxysterols for use as biomarkers for plaque vulnerability and instability. The identification of biomarkers in the blood that can distinguish between symptomatic and asymptomatic plaques remains an unresolved issue. PMID:24393847

Khatib, Soliman; Vaya, Jacob

2014-04-11

77

Scanning Electron Microscope Study of the Formation of Dental Plaque  

Microsoft Academic Search

Few investigations on the development of dental have considered the first changes which can occur on a cleaned tooth surface during the first 4 h of exposure to the Plaque oral environment. The present study has investigated, using the scanning electron microscope, the colonization of enamel surfaces in vivo, and some of the factors influencing plaque formation during the initial

C. A. Saxton

1973-01-01

78

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

79

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

80

Human endothelial cell culture plaques induced by Rickettsia rickettsii.  

PubMed Central

Primary cultures of human umbilical vein endothelial cells were inoculated with plaque-purified Rickettsia rickettsii. After adsorption of rickettsiae, monolayers were overlaid with medium containing 0.5% agarose. Small plaques appeared on day 4 postinoculation, and distinct 1- to 2-mm plaques were observed on day 5. Plaquing efficiency was less than that of primary chicken embryo cells in the same medium. Human endothelial cell monolayers were susceptible to infection by R. rickettsii and underwent necrosis as demonstrated by supravital staining. The topographic association of endothelial cell necrosis and rickettsial infection in the plaque model confirmed the direct cytopathic effect of R. rickettsii on human endothelium. Uninfected cells appeared normal by supravital staining and transmission electron microscopy. This model offers the possibility of investigating rickettsial pathogenesis and mechanisms of enhanced severity of Rocky Mountain spotted fever in specific genetically determined conditions. Images PMID:6809631

Walker, D H; Firth, W T; Edgell, C J

1982-01-01

81

Aortic Arch Plaques and Risk of Recurrent Stroke and Death  

PubMed Central

Background Aortic arch plaques are a risk factor for ischemic stroke. Although the stroke mechanism is conceivably thromboembolic, no randomized studies have evaluated the efficacy of antithrombotic therapies in preventing recurrent events. Methods and Results The relationship between arch plaques and recurrent events was studied in 516 patients with ischemic stroke, double–blindly randomized to treatment with warfarin or aspirin as part of the Patent Foramen Ovale in Cryptogenic Stroke Study (PICSS), based on the Warfarin-Aspirin Recurrent Stroke Study (WARSS). Plaque thickness and morphology was evaluated by transesophageal echocardiography. End-points were recurrent ischemic stroke or death over a 2-year follow-up. Large plaques (?4mm) were present in 19.6% of patients, large complex plaques (those with ulcerations or mobile components) in 8.5 %. During follow-up, large plaques were associated with a significantly increased risk of events (adjusted Hazard Ratio 2.12, 95% Confidence Interval 1.04-4.32), especially those with complex morphology (HR 2.55, CI 1.10-5.89). The risk was highest among cryptogenic stroke patients, both for large plaques (HR 6.42, CI 1.62-25.46) and large-complex plaques (HR 9.50, CI 1.92-47.10). Event rates were similar in the warfarin and aspirin groups in the overall study population (16.4% vs. 15.8%; p=0.43). Conclusions In patients with stroke, and especially cryptogenic stroke, large aortic plaques remain associated with an increased risk of recurrent stroke and death at two years despite treatment with warfarin or aspirin. Complex plaque morphology confers a slight additional increase in risk. PMID:19380621

Di Tullio, Marco R.; Russo, Cesare; Jin, Zhezhen; Sacco, Ralph L.; Mohr, J.P.; Homma, Shunichi

2010-01-01

82

Intravascular ultrasound assessment of the association between spatial orientation of ruptured coronary plaques and remodeling morphology of culprit plaques in ST-elevation acute myocardial infarction.  

PubMed

The aim of this study was to assess the association between the spatial location of plaque rupture and remodeling pattern of culprit lesions in acute anterior myocardial infarction (MI). Positive remodeling suggests a potential surrogate marker of plaque vulnerability, whereas plaque rupture causes thrombus formation followed by coronary occlusion and MI. Intravascular ultrasound (IVUS) can determine the precise spatial orientation of coronary plaque formation. We studied 52 consecutive patients with acute anterior MI caused by plaque rupture of the culprit lesion as assessed by preintervention IVUS. The plaques were divided into those with and without positive remodeling. We divided the plaques into three categories according to the spatial orientation of plaque rupture site: myocardial (inner curve), epicardial (outer curve), and lateral quadrants (2 intermediate quadrants). Among 52 plaque ruptures in 52 lesions, 27 ruptures were oriented toward the epicardial side (52%), 18 toward the myocardial side (35%), and 7 in the 2 lateral quadrants (13%). Among 35 plaques with positive remodeling, plaque rupture was observed in 21 (52%) on the epicardial side, 12 (34%) on the myocardial side, and 2 (6%) on the lateral side. However, among 17 plaques without positive remodeling, plaque rupture was observed in 6 (35%), 6 (35%), and 5 (30%), respectively (p = 0.047). Atherosclerotic plaques with positive remodeling showed more frequent plaque rupture on the epicardial side of the coronary vessel wall in anterior MI than those without positive remodeling. PMID:21892739

Kusama, Ikuyoshi; Hibi, Kiyoshi; Kosuge, Masami; Sumita, Shinnichi; Tsukahara, Kengo; Okuda, Jun; Ebina, Toshiaki; Umemura, Satoshi; Kimura, Kazuo

2012-11-01

83

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; Touzé, Emmanuel

2014-01-01

84

Effect of listerine on dental plaque and gingivitis.  

PubMed

The present study was performed in 10 adults in order to evaluate the effect of an antiseptic mouthrinse (Listerine) on the rate of dental plaque formation and gingivitis development during a 2-week period when all efforts towards active mechanical oral hygiene were withdrawn. The study was performed as a crossover study and was carried out during four consecutive 2-week periods. During the first and third periods (preparatory periods) the participants were subjected to repeated professional tooth cleanings in order to establish plaque- and gingivitis-free dentitions. During the second and fourth periods (test and control periods) the participants were not allowed to brush their teeth but rinsed their mouths three times a day with Listerine or a placebo mouthwash. Plaque Index, Gingival Index, gingival fluid flow, and crevicular leukocytes were assessed on d 0, 2, 4, 7, and 14. On d 7 and 14, dental plaque was removed from the right and left jaws respectively and the wet weights determined. The chemotactic activity elaborated by the plaques was studied in Boyden chambers. During the Listerine test period, significantly lower Plaque and Gingival Index values were scored and lower amounts of plaque could be sampled in comparison to the control period. PMID:1094528

Fornell, J; Sundin, Y; Lindhe, J

1975-01-01

85

The Vulnerable Plaque: the Real Villain in Acute Coronary Syndromes  

PubMed Central

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

Liang, Michael; Puri, Aniket; Devlin, Gerard

2011-01-01

86

Dental plaque biofilm in oral health and disease.  

PubMed

Dental plaque is an archetypical biofilm composed of a complex microbial community. It is the aetiological agent for major dental diseases such as dental caries and periodontal disease. The clinical picture of these dental diseases is a net result of the cross-talk between the pathogenic dental plaque biofilm and the host tissue response. In the healthy state, both plaque biofilm and adjacent tissues maintain a delicate balance, establishing a harmonious relationship between the two. However, changes occur during the disease process that transform this 'healthy' dental plaque into a 'pathogenic' biofilm. Recent advances in molecular microbiology have improved the understanding of dental plaque biofilm and produced numerous clinical benefits. Therefore, it is imperative that clinicians keep abreast with these new developments in the field of dentistry. Better understanding of the molecular mechanisms behind dental diseases will facilitate the development of novel therapeutic strategies to establish a 'healthy dental plaque biofilm' by modulating both host and microbial factors. In this review, the present authors aim to summarise the current knowledge on dental plaque as a microbial biofilm and its properties in oral health and disease. PMID:22319749

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

2011-01-01

87

Dural lucent line: characteristic sign of hyperostosing meningioma en plaque  

SciTech Connect

Hyperostosis of the skull associated with en plaque form of meningioma may present a diagnostic challenge, since the intracranial part of the tumor is not visualized by skull radiography, computed tomography (CT), or other neuroradiologic methods. The authors report four cases of hyperostosing meningioma en plaque demonstrating a characteristic feature: a subdural layer of ossification along the hyperostotic bone with a dural lucent interface. Polytomography or high-resolution CT at bone window settings is necessary to identify the dural lucent line. The absence of this sign does not exclude meningioma en plaque.

Kim, K.S.; Rogers, L.F.; Lee, C.

1983-12-01

88

Tuberculoma of the cervical spinal canal mimicking en plaque meningioma.  

PubMed

A previously healthy, HIV-negative, 40-year-old man presented with a 2-month history of progressive weakness of his left arm. Magnetic resonance imaging revealed an intradural, extramedullary plaque-shaped lesion at C6-T1 levels with high contrast enhancement. Based on the patient's clinical and radiologic findings, it was believed that the patient had an en plaque meningioma, and he was operated on. Histologic examination of the mass revealed granulomas with multinucleated and Langhans-type giant cells, typical of a tuberculoma. Intradural extramedullary tuberculomas should be considered in the differential diagnosis of en plaque meningioma as a rare entity. PMID:15800442

Mirzai, Hasan

2005-04-01

89

Plaque and thrombus evaluation by optical coherence tomography.  

PubMed

Intravascular Optical Coherence Tomography has been explored as an imaging tool for vessel wall and thrombus characterization. OCT enables a high resolution arterial wall imaging, and light properties allow tissue characterization. It has been proved one of the most valuable imaging modalities for the evaluation of vulnerable plaque and thrombus. OCT has a unique capacity in volumetric quantification of calcium, and unlike ultrasound, light can easily penetrate calcified plaques. Finally, this review paper will address aspects of the validation method of plaque characterization and potential pitfalls and put in perspective new approaches that may help the evolution of the field. PMID:21336556

Kubo, Takashi; Xu, Chenyang; Wang, Zhao; van Ditzhuijzen, Nienke S; Bezerra, Hiram G

2011-02-01

90

Complement activation in amyloid plaques in Alzheimer’s dementia  

Microsoft Academic Search

Summary  Amyloid plaques in Alzheimer’s dementia contain complement factors C1q, C4 and C3. In the present study we demonstrate complement\\u000a activation in amyloid plaques using immunoenzymatical techniques and specific antibodies against subunits of individual complement\\u000a components and activated complement products. Amyloid plaques contain C1q and activated C3 fragments (C3c and C3d, g) but\\u000a no C1s and C3a. These findings demonstrate that

P. Eikelenboom; C. E. Hack; J. M. Rozemuller; F. C. Stam

1988-01-01

91

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

92

Surgical management of a mobile floating carotid plaque.  

PubMed

A mobile floating carotid plaque (MFCP) is an infrequent pathological lesion with an unknown natural history caused by thinning and rupture of the fibrous cap of the atheromatous plaque; it may result in repeated ischaemic strokes. Duplex carotid ultrasound is a non-invasive technique useful in defining the plaque morphology with high sensitivity and specificity. Due to the lack of evidence, treatment remains controversial. We present a patient with an asymptomatic MFCP diagnosed by ultrasound and treated with carotid endarterectomy without neurological complications due to the procedure and without restenosis nor residual flaps during the follow-up. PMID:25476457

Moncayo, Karla Elizabeth; Vidal, Juan Jose; García, Raúl; Pereira, David

2014-12-01

93

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

PubMed

The purpose of this study was to evaluate the potential clinical value of coronary plaque imaging with a new generation CT scanner and the interobserver variability of coronary plaque assessment with a new semiautomatic plaque analysis application. Thirty-five isolated plaques of the left anterior descending coronary artery from 35 patients were evaluated with a new semiautomatic plaque analysis application. All patients were scanned with a 256-slice MDCT scanner (Brilliance iCT, Philips Healthcare, Cleveland OH, USA). Two independent observers evaluated lesion volume, maximum plaque burden, lesion CT number mean and standard deviation, and relative lesion composition. We found 10 noncalcified, 16 mixed, and 9 calcified lesions in our study cohort. Relative interobserver bias and variability for lesion volume were -37%, -13%, -49%, -44% and 28%, 16%, 37%, and 90% for all, noncalcified, mixed, and calcified lesions, respectively. Absolute interobserver bias and variability for relative lesion composition were 1.2%, 0.5%, 1.5%, 1.3% and 3.3%, 4.5%, 7.0%, and 4.4% for all, noncalcified, mixed, and calcified lesions, respectively. While mixed and calcified lesions demonstrated a high degree of lesion volume interobserver variability, noncalcified lesions had a lower degree of lesion volume interobserver variability. In addition, relative noncalcified lesion composition had a very low interobserver variability. Therefore, there may a role for MDCT in serial noncalcified plaque assessment with semiautomatic analysis software. PMID:20339922

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

2010-08-01

94

26. BOLLING MEMORIAL GROVE PLAQUE, AVENUE OF THE GIANTS, OLD ...  

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

26. BOLLING MEMORIAL GROVE PLAQUE, AVENUE OF THE GIANTS, OLD HIGHWAY 101. HUMBOLDT COUNTY, CALIFORNIA. LOOKING E. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

95

Coronary plaque imaging by coronary computed tomography angiography  

PubMed Central

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

Sato, Akira

2014-01-01

96

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

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

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

97

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

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

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

98

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

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

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

99

A helical microwave antenna for welding plaque during balloon angioplasty  

SciTech Connect

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

Liu, P.; Rappaport, C.M. [Northeastern Univ., Boston, MA (United States). Electrical and Computer Engineering Dept.

1996-10-01

100

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

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

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

101

10. VIEW OF PLAQUE ON ILLINOIS DEPARTMENT OF TRANSPORTATION HEADQUARTERS ...  

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

10. VIEW OF PLAQUE ON ILLINOIS DEPARTMENT OF TRANSPORTATION HEADQUARTERS GROUND, SPRINGFIELD, ILLINOIS; NOW IN CUSTODY OF WARREN COUNTY HIGHWAY SUPERINTENDENT - Campbell Bridge, Spanning Cedar Creek at Sumner Township Road 22, Little York, Warren County, IL

102

Cholesterol in the senile plaque: often mentioned, never seen  

Microsoft Academic Search

The lipid components of the senile plaque (SP) remain largely unknown. Senile plaques were said to be enriched in cholesterol\\u000a in a few studies using the cholesterol probe filipin and a histoenzymatic method based upon cholesterol oxidase activity.\\u000a We provide data that strongly suggest that these results are false-positive: the SPs were still stained in the absence of\\u000a the enzyme

Thibaud Lebouvier; Claire Perruchini; Maï Panchal; Marie-Claude Potier; Charles Duyckaerts

2009-01-01

103

Prion protein expression in senile plaques in Alzheimer's disease  

Microsoft Academic Search

Prion protein (PrPC) is a glycolipid-anchored cell membrane sialoglycoprotein that localises in presynaptic membranes. Since synapses are vulnerable to Alzheimer's disease (AD), the present study examines PrPC expression in senile plaques, one of the major structural abnormalities in AD, by single- and double-labelling immunohistochemistry. Punctate PrPC immunoreactivity is found in diffuse plaques, whereas isolated large coarse PrPC-positive granules reminiscent of

I. Ferrer; R. Blanco; M. Carmona; B. Puig; R. Ribera; M. J. Rey; T. Ribalta

2001-01-01

104

Fluorescence lifetime imaging microscopy for the characterization of atherosclerotic plaques  

PubMed Central

Atherosclerotic plaque composition has been associated with plaque instability and rupture. This study investigates the use of fluorescence lifetime imaging microscopy (FLIM) for mapping plaque composition and assessing features of vulnerability. Measurements were conducted in atherosclerotic human aortic samples using an endoscopic FLIM system (spatial resolution of 35 ?m; temporal resolution 200 ps) developed in our lab which allows mapping in one measurement the composition within a volume of 4 mm diameter × 250 ?m depth. Each pixel in the image represents a corresponding fluorescence lifetime value; images are formed through a flexible 0.6 mm side-viewing imaging bundle which allows for further intravascular applications. Based on previously recorded spectra of human atherosclerotic plaque, fluorescence emission was collected through two filters: f1: 377/50 and f2: 460/60 (center wavelength/bandwidth), which together provides the greatest discrimination between intrinsic fluorophores related to plaque vulnerability. We have imaged nine aortas and lifetime images were retrieved using a Laguerre expansion deconvolution technique and correlated with histopathology. Early results demonstrate discrimination using fluorescence lifetime between early, lipid-rich, and collagen-rich lesions which are consistent with previously reported time-resolved atherosclerotic plaque measurements. PMID:19606277

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

2009-01-01

105

Dosimetry for 125I seed (model 6711) in eye plaques.  

PubMed

The effect of eye plaque materials (gold backing and silastic seed-carrier insert) on the dose distribution around a single 125I seed has been measured, using cubic lithium fluoride thermoluminescent dosimeters (TLDs) 1 mm on an edge, in a solid water eye phantom embedded in a solid water head phantom. With an 125I seed (model 6711) positioned in the center slot of the silastic insert for a 20-mm plaque of the design used in the collaborative ocular melanoma study (COMS), dose was measured at 2-mm intervals along the plaque central axis (the seed's transverse axis) and at various off-axis points, both with and without the COMS gold backing placed over the insert. Monte Carlo calculations (MORSE code) were performed, as well, for these configurations and closely the same geometry but assuming a large natural water phantom. Additional Monte Carlo calculations treated the case, both for 20- and 12-mm gold plaques, where the silastic insert is replaced by natural water. Relative to previous measurements taken in homogeneous medium of the same material (without the eye plaque), the dose reduction found by both Monte Carlo and TLD methods was greater at points farther from the seed along the central axis and, for a given central-axis depth, at larger off-axis distances. Removal of the gold backing from the plaque did not make measurable difference in the dose reduction results (10% at 1 cm). PMID:8497229

Chiu-Tsao, S T; Anderson, L L; O'Brien, K; Stabile, L; Liu, J C

1993-01-01

106

Automatic plaque assay for the pharmaceutical industry using machine vision  

NASA Astrophysics Data System (ADS)

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

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

1995-10-01

107

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

108

Can anti-erosion dentifrices also provide effective plaque control?  

PubMed Central

Objective: While gingivitis and caries continue to be prevalent issues, there is growing concern about dental erosion induced by dietary acids. An oral hygiene product that protects against all these conditions would be beneficial. This study investigated the potential of two anti-erosion dentifrices to inhibit plaque. Methods: This was a randomized, three-period, two-treatment, double-blind, crossover study evaluating a stannous chloride/sodium fluoride dentifrice (SnCl2/NaF, blend-a-med® Pro Expert) and a popular anti-erosion dentifrice (NaF, Sensodyne® ProNamel™). During Period 3, subjects were randomized to repeat one treatment to evaluate any product carryover effects. Each treatment period was 17 days. Test dentifrices were used with a standard manual toothbrush. Digital plaque image analysis (DPIA) was employed at the end of each period to evaluate plaque levels (i) overnight (am prebrush); (ii) post-brushing with the test product (am post-brush); and (iii) mid-afternoon (pm). Analysis was conducted via an objective computer algorithm, which calculated total area of visible plaque. Results: Twenty-seven subjects completed the study. At all time points, subjects had statistically significantly (P ? 0.0001) lower plaque levels after using the SnCl2/NaF dentifrice than the NaF dentifrice. The antiplaque benefit for the SnCl2/NaF dentifrice versus the NaF dentifrice was: am prebrush = 26.0%; am post-brushing = 27.9%; pm = 25.7%. Conclusions: The SnCl2/NaF dentifrice provided significantly greater daytime and overnight plaque inhibition than the NaF toothpaste. When recommending dentifrice to patients susceptible to dental erosion, clinicians can consider one that also inhibits plaque. PMID:21356021

Bellamy, PG; Prendergast, M; Strand, R; Yu, Z; Day, TN; Barker, ML; Mussett, AJ

2011-01-01

109

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

110

Survival of human dental plaque flora in various transport media.  

PubMed

Dental plaque samples from (i) subjects with no apparent oral disease, (ii) mentally retarded subjects with periodontal disease, and (iii) subjects with active caries were collected in three transport media viz. a dithiothreitol poised balanced mineral salt solution designated as reduced transport fluid (RTF), VMG II, and modified Stuart medium (SBL). The samples were dispersed by sonic treatment, diluted in the respective medium in which they were collected, and cultured on MM10 sucrose agar. The efficiency of the transport media in the survival of dental plaque flora was determined by comparing the quantitative recovery (expressed as percentage of the initial viable count) from the specimens stored for various lengths of time. The data showed a great variation in the recovery of the oral bacterial flora from the plaque samples. VMG II and SBL served better than RTF as storage media for non-disease-associated dental plaque cultured under strict anaerobic conditions. Recoveries of bacteria from periodontal plaque specimens stored in RTF were higher than SBL and VMG II under identical conditions. The organisms present in the carious plaque samples appeared to survive much better in RTF and VMG II than in SBL as determined by conventional anaerobic culturing technique. However, VMG II showed a higher recovery of organisms from these specimens with an increase in the storage period, suggesting multiplication of the plaque flora. RTF did not allow the growth of oral bacterial flora under all experimental conditions. On the basis of the relative performance of these media it is suggested that RTF is a satisfactory medium for the transport of oral bacteria present in the samples. PMID:4628799

Syed, S A; Loesche, W J

1972-10-01

111

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

112

Relationship between plaque development and local hemodynamics in coronary arteries  

NASA Astrophysics Data System (ADS)

The mechanisms of plaque development in coronary arteries are not yet completely understood. Vessel geometry influences the local hemodynamics within a vessel, and the resulting wall shear stress in turn influences plaque development. Previously, we showed in-vivo that plaque tends to accumulate more on the inner curvature of a vessel than on its outer curvature. While vessel curvature is preserved during plaque progression, the local wall shear stresses change with lumen narrowing. The aim of this study was to test how the hypothesis that locations of low wall shear stress coincide with circumferentially larger plaque accumulation depends on vascular remodeling with or without lumen narrowing. We have analyzed 39 in-vivo intravascular-ultrasound pullbacks, for which geometrically accurate 3-D models were obtained by fusion with x-ray angiography. Distorting subsegments (branches, calcifications, stents) were discarded, and the relative number of vessel locations was determined within a 10-40% area-stenosis range. This range corresponds to compensatory enlargement (outward or positive vessel remodeling), but not yet lumen narrowing, and these vessel segments were a focus of our study. For each segment, we determined the relative number of vessel locations for which circumferentially low wall shear stress coincided with larger plaque thickness and vice versa. The inverse association between wall shear stress and plaque thickness was significantly more pronounced (p<0.005) in vessel cross sections exhibiting compensatory enlargement without luminal narrowing than when the full spectrum of vessel stenosis severity was considered. Thus, the hypothesis is supported more in subsegments with less developed disease.

Wahle, Andreas; Lopez, John J.; Olszewski, Mark E.; Vigmostad, Sarah C.; Braddy, Kathleen C.; Brennan, Theresa M. H.; Bokhari, Syed W.; Bennett, J. Gray; Holper, Elizabeth M.; Rossen, James D.; Chandran, Krishnan B.; Sonka, Milan

2005-04-01

113

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

114

ROPES eye plaque dosimetry: commissioning and verification of an ophthalmic brachytherapy treatment planning system  

NASA Astrophysics Data System (ADS)

In this study, the Plaque SimulatorTM eye plaque brachytherapy planning system was commissioned for ROPES eye plaques and Amersham Health model 6711 Iodine 125 seeds, using TG43-UI data. The brachytherapy module of the RADCALC® independent checking program was configured to allow verification of the accuracy of the dose calculated by Plaque SimulatorTM. Central axis depth dose distributions were compared and observed to agree to within 2% for all ROPES plaque models and depths of interest. Experimental measurements were performed with a customized PRESAGEm 3-D type dosimeter to validate the calculated depth dose distributions. Preliminary results have shown the effect of the stainless steel plaque backing decreases the measured fluorescence intensity by up to 25%, and 40% for the 15 mm and 10 mm diameter ROPES plaques respectively. This effect, once fully quantified should be accounted for in the Plaque SimulatorTM eye plaque brachytherapy planning system.

Poder, J.; Annabell, N.; Geso, M.; Alqathami, M.; Corde, S.

2013-06-01

115

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

116

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

PubMed

Kidney stones develop attached to sub-epithelial plaques of calcium phosphate (CaP) crystals (termed Randall's plaque) and/or form as a result of occlusion of the openings of the Ducts of Bellini by stone-forming crystals (Randall's plugs). These plaques and plugs eventually extrude into the urinary space, acting as a nidus for crystal overgrowth and stone formation. To better understand these regulatory mechanisms and the pathophysiology of idiopathic calcium stone disease, this review provides in-depth descriptions of the morphology and potential origins of these plaques and plugs, summarizes existing animal models of renal papillary interstitial deposits, and describes factors that are believed to regulate plaque formation and calcium overgrowth. Based on evidence provided within this review and from the vascular calcification literature, we propose a "unified" theory of plaque formation-one similar to pathological biomineralization observed elsewhere in the body. Abnormal urinary conditions (hypercalciuria, hyperoxaluria, and hypocitraturia), renal stress or trauma, and perhaps even the normal aging process lead to transformation of renal epithelial cells into an osteoblastic phenotype. With this de-differentiation comes an increased production of bone-specific proteins (i.e., osteopontin), a reduction in crystallization inhibitors (such as fetuin and matrix Gla protein), and creation of matrix vesicles, which support nucleation of CaP crystals. These small deposits promote aggregation and calcification of surrounding collagen. Mineralization continues by calcification of membranous cellular degradation products and other fibers until the plaque reaches the papillary epithelium. Through the activity of matrix metalloproteinases or perhaps by brute physical force produced by the large sub-epithelial crystalline mass, the surface is breached and further stone growth occurs by organic matrix-associated nucleation of CaOx or by the transformation of the outer layer of CaP crystals into CaOx crystals. Should this theory hold true, developing an understanding of the cellular mechanisms involved in progression of a small, basic interstitial plaque to that of an expanding, penetrating plaque could assist in the development of new therapies for stone prevention. PMID:25119506

Khan, Saeed R; Canales, Benjamin K

2015-01-01

117

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

118

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

119

[Motivation on plaque control and gingival bleeding in school children].  

PubMed

The objective of the study is to evaluate the impact of two pedagogical motivational approaches for plaque and gingival bleeding control among 135 students of local public schools in Santa Tereza, Brazil, in 1999 The motivational program consisted of different educational strategies offered to two distinct groups: Group A, who attended only one explanatory session about oral hygiene, and Group B, who attended a total of four pedagogical sessions. In order to evaluate the methodology applied, the visible plaque index (according to Ainamo & Bay, 1975) and gingival bleeding index (according to L e and Silness, 1963) were calculated. A highly statistically significant reduction in the visible plaque index and gingival bleeding index was observed in both groups after the educational sessions (p<0.001). Moreover, a higher reduction in the gingival bleeding index and an even more accentuated decrease in the visible plaque index was found in group B when compared to group A (p<0.001). In conclusion, the motivational reinforcement in educational and preventive programs has a positive effect for the reduction and control of gingival bleeding and bacterial plaque. PMID:12471391

Toassi, Ramona Fernanda Ceriotti; Petry, Paulo Cauhy

2002-10-01

120

[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

121

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

122

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

123

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

124

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

125

A Neprilysin Polymorphism and Amyloid-? Plaques after Traumatic Brain Injury  

PubMed Central

Abstract Traumatic brain injury (TBI) induces the rapid formation of Alzheimer's disease (AD)-like amyloid-? (AB) plaques in about 30% of patients. However, the mechanisms behind this selective plaque formation are unclear. We investigated a potential association between amyloid deposition acutely after TBI and a genetic polymorphism of the AB-degrading enzyme, neprilysin (n?=?81). We found that the length of the GT repeats in AB-accumulators was longer than in non-accumulators. Specifically, there was an increased risk of AB plaques for patients with more than 41 total repeats (p?plaque deposition (p?=?0.03; OR: 5.2). In contrast, the presence of 20?GT repeats in one allele was independently associated with a reduced incidence of AB deposition (p?=?0.003). These data suggest a genetically linked mechanism that determines which TBI patients will rapidly form AB plaques. Moreover, these findings provide a potential genetic screening test for individuals at high risk of TBI, such as participants in contact sports and military personnel. PMID:19326964

Johnson, Victoria E.; Stewart, William; Graham, David I.; Stewart, Janice E.; Praestgaard, Amy H.

2009-01-01

126

Low copper and high manganese levels in prion protein plaques  

USGS Publications Warehouse

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.

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

2013-01-01

127

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

128

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

129

Multispectral optoacoustic tomography resolves smart probe activation in vulnerable plaques  

NASA Astrophysics Data System (ADS)

In this work, we show, for the first time to our knowledge, that multispectral optoacoustic tomography (MSOT) can deliver high resolution images of activatable molecular probe's distribution, sensitive to matrix metalloproteinases (MMP), deep within optically scattering human carotid specimen. It is further demonstrated that this method can be used in order to provide accurate maps of vulnerable plaque formations in atherosclerotic disease. Moreover, optoacoustic images can simultaneously show the underlining plaque morphology for accurate localization of MMP activity in three dimensions. This performance directly relates to small animal screening applications and to clinical potential as well.

Razansky, Daniel; Harlaar, Niels J.; Hillebrands, Jan-Luuk; Taruttis, Adrian; Herzog, Eva; Zeebregts, Clark; van Dam, Goitzen; Ntziachristos, Vasilis

2011-03-01

130

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

131

Fluorescence of experimental atheromatous plaques with hematoporphyrin derivative.  

PubMed Central

Fluorescence of hematoporphyrin derivative (HPD) has been used clinically to localize malignant neoplasms because of its selective accumulation in these tissues. We tested the hypothesis that HPD may also be selectively concentrated within atheromatous plaques. 48 h after HPD injection in a variety of species, selective fluorescence of atheromatous plaques of the aorta was seen in each animal (rabbits and Patas monkey) exhibiting such lesions. No fluorescence could be demonstrated in aortic segments free of atheromatous involvement. Since the efficacy of photodynamic destruction of malignant tumors with HPD has been demonstrated in clinical studies, the observations of the present study may have therapeutic implications in atheromatosis. Images PMID:6822671

Spears, J R; Serur, J; Shropshire, D; Paulin, S

1983-01-01

132

Effects of extracellular plaque components on the chlorhexidine sensitivity of strains of Streptococcus mutans and human dental plaque  

SciTech Connect

An in vitro study was undertaken to determine the effects of sucrose-derived extracellular plaque components on the sensitivity of selected oral bacteria to chlorhexidine (CX). Cultures of Streptococcus mutans HS-6, OMZ-176, Ingbritt C, 6715-wt13, and pooled human plaque were grown in trypticase soy media with or without 1% sucrose. The sensitivity to CX of bacteria grown in each medium was determined by fixed-time exposure to CX and subsequent measurement of /sup 3/H-thymidine uptake. One-hour exposure to CX at concentrations of 10(-4) M (0.01% w/v) or greater substantially inhibited subsequent cellular division among all the S. mutans strains and human plaque samples tested. An IC50 (the CX concentration which depressed /sup 3/H-thymidine incorporation to 50% of control level) of close to 10(-4) M was noted for S. mutans strains HS-6, OMZ-176, and 6715-wt13 when grown in the presence of sucrose. The same strains grown in cultures without added sucrose showed about a ten-fold greater sensitivity to CX (IC50 close to 10(-5) M). A three-fold difference was noted for S. mutans Ingbritt C. Only a slight increase in the IC50 was noted for the plaque samples cultured in sucrose-containing media, but their threshold for depression of /sup 3/H-thymidine uptake by CX was lower than that for the sucrose-free plaque samples. The study showed that extracellular products confer some protection against CX to the bacteria examined, and provided an explanation for the disparity between clinically-recommended concentrations for plaque suppression and data on in vitro susceptibility.

Wolinsky, L.E.; Hume, W.R.

1985-08-01

133

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.

134

21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.  

Code of Federal Regulations, 2012 CFR

...identified as a device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical...that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b) Classification . Class II...

2012-04-01

135

21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.  

Code of Federal Regulations, 2013 CFR

...identified as a device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical...that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b) Classification . Class II...

2013-04-01

136

21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.  

Code of Federal Regulations, 2011 CFR

...identified as a device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical...that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b) Classification . Class II...

2011-04-01

137

21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.  

...identified as a device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical...that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b) Classification. Class II...

2014-04-01

138

21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.  

Code of Federal Regulations, 2010 CFR

...identified as a device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical...that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b) Classification . Class II...

2010-04-01

139

Modelling of fluid structure interactions in stenosed arteries: effect of plaque deformability  

E-print Network

Modelling of fluid structure interactions in stenosed arteries: effect of plaque deformability of fluid structure interactions in stenosed arteries. Stenoses in arteries are usually induced the mechanical response of plaques in the arteries [1]. This mechanical response is mainly induced

Paris-Sud XI, Université de

140

Identification of Amyloid Plaques in Retinas from Alzheimer’s Patients and Noninvasive In Vivo Optical Imaging of Retinal Plaques in a Mouse Model  

PubMed Central

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 portrays 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 APPSWE/PS1?E9 transgenic mice (AD-Tg; n=18) and 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.

2010-01-01

141

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

142

Comparative Studies of Plaque Variants Derived From a Florida Strain of Venezuelan Equine Encephalomyelitis Virus  

PubMed Central

Small- and large-plaque variants of a Florida strain (Fe 3-7c) of Venezuelan equine encephalomyelitis virus were studied in vivo and in vitro. The small-plaque variant was less virulent in mice, hamsters, and guinea pigs than the large-plaque variant. The variants could be distinguished by calcium phosphate chromatography. The implications of plaque variants within a mixed virus population are discussed. Images PMID:4344368

Pedersen, Carl E.; Slocum, Donald R.; Robinson, David M.

1972-01-01

143

Fractal analysis of ultrasound images of carotid atherosclerotic plaque  

Microsoft Academic Search

In this paper, we investigate the possibility of using the fractal dimension to characterise carotid atheromatous plaques from B-mode ultrasound images. The images were obtained from ten symptomatic and nine asymptomatic subjects. Symptomatic subjects included patients with previous history of cerebral events, whereas asymptomatic ones had no evidence of any cerebral symptoms prior to the time of the investigation. For

P. Asvestas; S. Golemati; G. K. Matsopoulos; K. S. Nikita

2001-01-01

144

Antibody Testing Against Canine Coronavirus by Immunoperoxidase Plaque Staining  

Microsoft Academic Search

The application of the immunoperoxidase (IP) plaque staining procedure (IP test) to the diagnosis of canine coronavirus (CCV) infection was investigated. The IP test did not react with sera from either 15 specific pathogen-free (SPF) dogs or 7 SPF dogs immunized with a multivalent vaccine, including canine parvovirus type 2, canine distemper virus, canine adenovirus type 2, and canine parainfluenza

T. Soma; M. Hara; H. Ishii; S. Yamamoto

2001-01-01

145

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

146

Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque  

SciTech Connect

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

Saba, Luca, E-mail: lucasaba@tiscali.i [Azienda Ospedaliero-Universitaria di Cagliari, Department of Radiology (Italy); Potters, Fons; Lugt, Aad van der [Erasmus Medical Center Rotterdam, Department of Radiology (Netherlands); Mallarini, Giorgio [Azienda Ospedaliero-Universitaria di Cagliari, Department of Radiology (Italy)

2010-08-15

147

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

148

Fermentation of five sucrose isomers by human dental plaque bacteria.  

PubMed

Sucrose has five structural isomers: palatinose, trehalulose, turanose, maltulose and leucrose. Although these isomers have been reported to be noncariogenic disaccharides, which cannot be utilized by mutans streptococci, there is no information about their fermentability by other bacteria in dental plaque. The purpose of the present study was to examine whether these isomers were fermented by predominant bacteria in human dental plaque. Clinical bacterial isolates obtained from dental plaque from 3 children aged 22 months to 50 months (146 strains) were inoculated into 3 ml of peptone-yeast extract (PY medium) containing glucose for 1 day, then an aliquot of 20 microl of culture medium was inoculated into 1 ml of PY medium containing 1% (w/v) of the respective test carbohydrates. After incubation for 1 day, the pH values and the optical density at 660 nm of the cultures were measured. Fermentation ability was measured by pH or=0.5. Of the clinical isolates, 33% fermented palatinose, and 69% of these were Actinomyces species. All of the palatinose-fermenting bacterial strains fermented trehalulose, 25% fermented turanose, 70% fermented maltulose and 23% fermented leucrose. We therefore conclude that, in human dental plaque, there are significant numbers of bacteria that are able to ferment sucrose isomers. PMID:14571118

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

2003-01-01

149

T. J. Lee Presents Plaque to Vice President Dan Quayle  

NASA Technical Reports Server (NTRS)

Vice President Dan Quayle holds up an inscribed plaque presented by Marshall Space Flight Center Director T. J. Lee (right) during Quayle's August 31, 1992 visit. While at Marshall, Quayle participated in a roundtable discussion with aerospace managers and addressed Center employees in Building 4755.

1992-01-01

150

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

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

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

151

Plaque formation and marginal gingivitis associated with restorative materials.  

PubMed

The presence of restorative materials on tooth surfaces is perceived to be a contributing factor to periodontal disease. This observation is a result of the increased accumulation of plaque on restorations adjacent to the gingiva, which may lead to gingivitis. Plaque is believed to adhere better to restorations than to enamel. This may be due to the surface characteristics of restorative materials such as surface roughness and surface-free energy inherent in the materials. This article reviews the experimental studies of plaque formation on different restorative materials. In addition, clinical studies analyzing and comparing restorative materials and the consequent formation of gingivitis are reviewed. While in vitro and in vivo studies show variations in plaque formation among restorative materials and enamel, clinical studies demonstrate that the progression of gingivitis can be prevented if patients maintain adequate oral hygiene and home care. Therefore, instructing the patient to maintain proper oral hygiene and home care is more important than the choice of restorative material. PMID:23268568

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

2012-01-01

152

Plaque formation and marginal gingivitis associated with restorative materials.  

PubMed

The presence of restorative materials on tooth surfaces is perceived to be a contributing factor to periodontal disease. This observation is a result of the increased accumulation of plaque on restorations adjacent to the gingiva, which may lead to gingivitis. Plaque is believed to adhere better to restorations than to enamel. This may be due to the surface characteristics of restorative materials such as surface roughness and surface-free energy inherent in the materials. This article reviews the experimental studies of plaque formation on different restorative materials. In addition, clinical studies analyzing and comparing restorative materials and the consequent formation of gingivitis are reviewed. While in vitro and in vivo studies show variations in plaque formation among restorative materials and enamel, clinical studies demonstrate that the progression of gingivitis can be prevented if patients maintain adequate oral hygiene and home care. Therefore, instructing the patient to maintain proper oral hygiene and home care is more important than the choice of restorative material. PMID:23738894

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

2011-05-01

153

Ultrasound imaging versus morphopathology in cardiovascular diseases. Coronary atherosclerotic plaque  

PubMed Central

This review article is aimed at comparing the results of histopathological and clinical imaging studies to assess coronary atherosclerotic plaques in humans. In particular, the gap between the two techniques and its effect on the understanding of the pathophysiological basis of coronary artery disease is critically discussed. PMID:15598352

Baroldi, Giorgio; Bigi, Riccardo; Cortigiani, Lauro

2004-01-01

154

Plaque busters: strategies to inhibit amyloid formation in Alzheimer's disease  

Microsoft Academic Search

Alzheimer's disease is a devastating degenerative disorder of the brain for which there is no cure or effective treatment. Although the etiology of Alzheimer's disease is not fully understood, recent research suggests that deposition of cerebral amyloid plaques is central to the disease process. Therefore, an attractive therapeutic strategy for Alzheimer's disease is to prevent, reduce or reverse amyloid deposition

Claudio Soto

1999-01-01

155

Tangles and plaques in nondemented aging and ?preclinical? Alzheimer's disease  

Microsoft Academic Search

The distribution and density of neurofibrillary tangles and amyloid plaques was studied in a unique series of cases whose premortem cognitive status had been assessed with the Clinical Dementia Rating (CDR), including 39 nondemented cases (CDR 5 0; age, 51- 88 years), 15 very mildly demented cases (CDR 5 0.5), and 8 severely demented (CDR 5 3) cases. The initial

Joseph L. Price; John C. Morris

1999-01-01

156

Optical coherence tomography for imaging the vulnerable plaque  

PubMed Central

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. PMID:16674177

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

2009-01-01

157

Recent Advances in Visualizing Alzheimer's Plaques by Magnetic Reso- nance Imaging  

Microsoft Academic Search

The presence of amyloid plaques in the brain is one of prominent histological features of Alzheimer's disease. However, imaging of amyloid plaques in vivo in humans is not yet feasible. Recent technical advances in high resolution magnetic resonance imaging (MRI) methods in mice have enabled not only the detection of amyloid plaques in vivo but also allowed to monitor the

Niels Braakman; Mark A. van Buchem; Reinhard Schliebs; Huub J. M. de Groot

2009-01-01

158

Plaque disruption and coronary thrombosis: new insight into pathogenesis and prevention.  

PubMed

Clinical and pathologic studies have confirmed that disruption or superficial erosion of atherosclerotic plaque is the major cause of coronary thrombosis, which is the primary mechanism responsible for acute coronary syndromes of unstable angina, acute myocardial infarction, and sudden cardiac death. Serial angiographic studies have shown that nearly 60-70% of acute coronary syndromes evolve from mildly to moderately obstructive atherosclerotic plaques. The risk of plaque disruption appears to be a function of both plaque vulnerability (intrinsic factors) and extrinsic triggers, and is determined largely by the size of the lipid-rich atheromatous core, the thickness of the fibrous cap covering the core, and the presence of ongoing inflammation within and underneath the cap. Hemodynamic or mechanical stresses may precipitate plaque disruption, particularly in places where the fibrous cap is weakest, such as the shoulders. The degree of thrombosis following plaque disruption depends on the thrombogenicity of the disrupted plaque, the disturbed local rheology, and the systemic thrombotic-thrombolytic milieu. Surges in sympathetic activity (such as those provoked by sudden vigorous exercise, emotional stress, or cold weather) may also trigger plaque disruption. These observations have led to the concept of plaque stabilization as a new strategy for the prevention of acute coronary syndromes. Plaque stabilization can be achieved through pharmacologic and lifestyle-modifying interventions that alter plaque composition and/or inflammatory activity within the plaque and thus reduce its vulnerability to disruption. PMID:9422851

Shah, P K

1997-11-01

159

Imaging of high-risk carotid artery plaques: current status and future directions.  

PubMed

In this paper, the authors review the definition of high-risk plaque as developed by experienced researchers in atherosclerosis, including pathologists, clinicians, molecular biologists, and imaging scientists. Current concepts of vulnerable plaque are based on histological studies of coronary and carotid artery plaque as well as natural history studies and include the presence of a lipid-rich necrotic core with an overlying thin fibrous cap, plaque inflammation, fissured plaque, and intraplaque hemorrhage. The extension of these histologically identified high-risk carotid plaque features to human in vivo MRI is reviewed as well. The authors also assess the ability of in vivo MRI to depict these vulnerable carotid plaque features. Next, the ability of these MRI-demonstrated high-risk carotid plaque features to predict the risk of ipsilateral carotid thromboembolic events is reviewed and compared with the risk assessment provided by simple carotid artery stenosis measurements. Lastly, future directions of high-risk carotid plaque MRI are discussed, including the potential for increased clinical availability and more automated analysis of carotid plaque MRI. The ultimate goal of high-risk plaque imaging is to design and run future multicenter trials using carotid plaque MRI to guide individual patient selection and decisions about optimal atherosclerotic treatment strategies. PMID:24380475

DeMarco, J Kevin; Huston, John

2014-01-01

160

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.

161

The Impact of Calcification on the Biomechanical Stability of Atherosclerotic Plaques  

Microsoft Academic Search

Background—Increased biomechanical stresses in the fibrous cap of atherosclerotic plaques contribute to plaque rupture and, consequently, to thrombosis and myocardial infarction. Thin fibrous caps and large lipid pools are important determinants of increased plaque stresses. Although coronary calcification is associated with worse cardiovascular prognosis, the relationship between atheroma calcification and stresses is incompletely described. Methods and Results—To test the hypothesis

Hayden Huang; Renu Virmani; Hesham Younis; Allen P. Burke; Roger D. Kamm; Richard T. Lee

2001-01-01

162

Genetic Susceptibility for Alzheimer’s Disease Neuritic Plaque Pathology  

PubMed Central

Objective To investigate whether Alzheimer’s disease (AD) susceptibility loci from genome-wide association studies (GWAS) impact neuritic plaque pathology and to additionally identify novel risk loci for this trait. Design Candidate analysis of single nucleotide polymorphisms (SNPs) and GWAS in a joint clinicopathologic cohort study, followed by targeted validation in independent neuroimaging cohorts. Participants and Setting 725 deceased subjects from the Religious Orders and Rush Memory and Aging Project, two prospective, community-based studies of aging; the validation neuroimaging cohort consisted of 114 subjects from multiple clinical and research centers. Main Outcome Measures A quantitative measure of neuritic plaque pathologic burden, based on assessments of silver-stained tissue averaged from multiple brain regions. Validation based on ?-amyloid load by immunocytochemistry, and replication with fibrillar ?-amyloid Positron Emission Tomography (PET) imaging with Pittsburgh Compound B or florbetapir. Results Besides the previously reported APOE and CR1 loci, we find that ABCA7 (rs3764650, P=0.02) and CD2AP (rs9349407, P=0.03) AD susceptibility loci are associated with neuritic plaque burden. In addition, among the top results of our GWAS, we discovered a novel variant near the amyloid precursor protein gene (APP, rs2829887) that is associated with neuritic plaques (P=3.3×10?6). This polymorphism was associated with postmortem ?-amyloid load, as well as fibrillar ?-amyloid in two independent cohorts of adults with normal cognition. Conclusion These findings enhance understanding of AD risk factors by relating validated susceptibility alleles to increased neuritic plaque pathology and implicate common genetic variation at the APP locus in the earliest, pre-symptomatic stages of AD. PMID:23836404

Shulman, Joshua M.; Chen, Kewei; Keenan, Brendan T.; Chibnik, Lori B.; Fleisher, Adam; Thiyyagura, Pradeep; Roontiva, Auttawut; McCabe, Cristin; Patsopoulos, Nikolaos A.; Corneveaux, Jason J.; Yu, Lei; Huentelman, Matthew J.; Evans, Denis A.; Schneider, Julie A.; Reiman, Eric M.; De Jager, Philip L.; Bennett, David A.

2013-01-01

163

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

164

Patient-specific prediction of coronary plaque growth from CTA angiography: a multiscale model for plaque formation and progression.  

PubMed

Computational fluid dynamics methods based on in vivo 3-D vessel reconstructions have recently been identified the influence of wall shear stress on endothelial cells as well as on vascular smooth muscle cells, resulting in different events such as flow mediated vasodilatation, atherosclerosis, and vascular remodeling. Development of image-based modeling technologies for simulating patient-specific local blood flows is introducing a novel approach to risk prediction for coronary plaque growth and progression. In this study, we developed 3-D 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 3-D 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 3-D model was created. It includes blood flow and LDL concentration, as well as plaque formation and progression. 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 by repetition of CTA, six months after. PMID:22665513

Parodi, Oberdan; Exarchos, Themis P; Marraccini, Paolo; Vozzi, Federico; Milosevic, Zarko; Nikolic, Dalibor; Sakellarios, Antonis; Siogkas, Panagiotis K; Fotiadis, Dimitrios I; Filipovic, Nenad

2012-09-01

165

Proteomic characterization of postmortem amyloid plaques isolated by laser capture microdissection.  

PubMed

The presence of amyloid plaques in the brain is one of the pathological hallmarks of Alzheimer's disease (AD). We report here a comprehensive proteomic analysis of senile plaques from postmortem AD brain tissues. Senile plaques labeled with thioflavin-S were procured by laser capture microdissection, and their protein components were analyzed by liquid chromatography coupled with tandem mass spectrometry. We identified a total of 488 proteins co-isolated with the plaques, and we found multiple phosphorylation sites on the neurofilament intermediate chain, implicating the complexity and diversity of cellular processes involved in the plaque formation. More significantly, we identified 26 proteins enriched in the plaques of two AD cases by quantitative comparison with surrounding non-plaque tissues. The localization of several proteins in the plaques was further confirmed by the approach of immunohistochemistry. In addition to previously identified plaque constituents, we discovered novel association of dynein heavy chain with the plaques in human postmortem brain and in a double transgenic AD mouse model, suggesting that neuronal transport may play a role in neuritic degeneration. Overall, our results revealed for the first time the sub-proteome of amyloid plaques that is important for further studies on disease biomarker identification and molecular mechanisms of AD pathogenesis. PMID:15220353

Liao, Lujian; Cheng, Dongmei; Wang, Jian; Duong, Duc M; Losik, Tatyana G; Gearing, Marla; Rees, Howard D; Lah, James J; Levey, Allan I; Peng, Junmin

2004-08-27

166

Mechanical action of the blood onto atheromatous plaques: influence of the stenosis shape and morphology.  

PubMed

The vulnerability of atheromatous plaques in the carotid artery may be related to several factors, the most important being the degree of severity of the endoluminal stenosis and the thickness of the fibrous cap. It has recently been shown that the plaque length can also affect the mechanical response significantly. However, in their study on the effect of the plaque length, the authors did not consider the variations of the plaque morphology and the shape irregularities that may exist independently of the plaque length. These aspects are developed in this paper. The mechanical interactions between the blood flow and an atheromatous plaque are studied through a numerical model considering fluid-structure interaction. The simulation is achieved using the arbitrary Lagrangian-Eulerian scheme in the COMSOL TM commercial finite element package. The stenosis severity and the plaque length are, respectively, set to 45% and 15 mm. Different shapes of the stenosis are modelled, considering irregularities made of several bumps over the plaque. The resulting flow patterns, wall shear stresses, plaque deformations and stresses in the fibrous cap reveal that the effects of the blood flow are amplified if the slope upstream stenosis is steep or if the plaque morphology is irregular with bumps. More specifically, the maximum stress in the fibrous cap is 50% larger for a steep slope than for a gentle slope. These results offer new perspectives for considering the shape of plaques in the evaluation of the vulnerability. PMID:22757631

Belzacq, Tristan; Avril, Stéphane; Leriche, Emmanuel; Delache, Alexandre

2014-04-01

167

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.; Löwik, Clemens W. G. M.; Hamming, Jaap F.; Jukema, J. Wouter; Quax, Paul H. A.

2012-01-01

168

Identification of Noncalcified Plaque in Young Persons with Diabetes  

PubMed Central

Purpose Coronary computed tomographic angiography (CTA) is a valuable tool for assessing coronary artery disease (CAD). Although statin use is widely recommended for persons with diabetes older than age 40, little is known about the presence and severity of CAD in younger patients with diabetes mellitus (DM). We evaluated coronary artery calcium (CAC) and coronary CTA in young persons with both DM1 and DM2 in an attempt to detect the earliest objective evidence of arteriosclerosis eligible for primary prevention. Methods and Materials We prospectively enrolled 40 persons with DM (25 type 1 and 15 type 2) between the ages of 19 and 35 presenting with diabetes for 5 years or longer. All patients underwent coronary CTA and CAC scans to evaluate for early atherosclerotic disease. Each plaque in the coronary artery was classified as noncalcified or calcified-mixed. We also evaluated all segments with stenosis, dividing them into mild (<50%), moderate (50–70%), and severe (>70%). Results The average age of the DM1 subjects were 26 ± 4 (SD) years and 30 ± 4 years for DM2 patients (P < .01), with duration of diabetes of 8 ± 5 years and average HbA1c% of 8.7 ± 1.6 (norm = 4.6–6.2). Abnormal scans were present in 57.5%, noncalcified in 35% and calcified-mixed plaque in 22.5%. Persons with DM2 had a higher prevalence of positive coronary CTA scans than DM1: 80% versus 44% (P < .03) and more positive CAC scores 53% versus 4%, (P < .01). The total segment score of 2.1 ± 3.4 (P < .01) and total plaque score 1.9 ± 2.8 (P < .01) were highly correlated to each other. Plaque was almost uniformly absent below age 25, and became increasingly common in individuals over the age of 25 years for both groups. The average radiation exposure was 2.5 ± 1.3 mSv. Conclusion Our study verifies that early CAD can be diagnosed with coronary CTA and minimal radiation exposure in young adults with DM. A negative CAC score was not sufficient to exclude early CAD as we observed a preponderance of noncalcified plaque in this cohort. Coronary CTA in young DM patients older than age 25 may provide earlier identification of disease than does a CAC because only non-calcified plaque is frequently present. Coronary CTA provides an opportunity to consider initiation of earlier primary CAD prevention rather than waiting for the age of 40 as currently recommended by the American Diabetes Association guidelines. PMID:22542200

Madaj, Paul M.; Budoff, Matthew J.; Li, Dong; Tayek, John A.; Karlsberg, Ronald P.; Karpman, Harold L.

2014-01-01

169

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

170

Mechanical behavior of calcified plaques: a summary of compression and stress-relaxation experiments.  

PubMed

This paper summarizes the results from mechanical testing of atherosclerotic plaques performed in the Cardiovascular Mechanics Laboratory and the Laboratory for Implantable Materials at UMBC. The motivation for our work is that balloon angioplasty, stenting, and roto-ablation are mechanical processes that are designed to permanently alter the shape of an occluded arterial lumen. The mechanisms of permanent plaque deformation are not known. Therefore, to study the mechanical behavior of plaques, we performed mechanical tests on atherosclerotic lesions with different compositions and investigated differences in the materials' mechanical responses. Atherosclerotic plaque specimens were subjected to two main types of loading: multiple cyclic compression and stress-relaxation. The multiple-cycle test protocol was two fifteen-cycle loading phases that were separated by a 10-15 minute unloaded "rest" period. The compressive stress-relaxation test protocol was a series of three consecutive loadings (called phases I, II, and III). Each phase consisted of a 25% compression that was achieved in less than 1 second, a 10 minute relaxation period, and a 10 minute unloaded "rest" period between loadings. In the multiple cycle compressive loading, plaques exhibited three distinct types of behavior, which corresponded to the plaque compositions. Calcified plaques showed behaviors distinct from other plaque types and healthy vessels. In contrast to the cyclic compression results, plaque types could not be distinguished solely on the basis of stress relaxation behavior. Calcified and fibrous plaques had similar behavior, and therefore histology was used for definite identification. Calcified plaques have unique mechanical properties, and therefore interventions like angioplasty, roto-ablation, and stenting may require protocols specific for calcified lesions. The optimum protocols for calcified plaques may be quite different from plaques with other compositions. It is essential to learn more about the mechanical behavior of all plaque types to increase the success rate of occlusive atherosclerosis treatments. PMID:10769409

Topoleski, L D; Salunke, N V

2000-01-01

171

Definition of human rotavirus serotypes by plaque reduction assay.  

PubMed Central

Twenty different human rotavirus reassortants were characterized serologically by a plaque reduction assay as belonging to one of three distinct serotypes. Fourteen were similar if not identical to our prototype Wa strain; two were like the prototype DS-1 strain, and four belonged to a third serotype for which a prototype has not yet been selected. Hyperimmune sera raised against the three serotypes were required to distinguish among them, since postinfection sera had lower titers and were more cross-reactive than hyperimmune sera. These results confirmed the ability of a qualitative cytopathic neutralization test to predict correctly the Wa or DS-1 serotype. A strain of rhesus rotavirus (MMU 18006) was identified as belonging to the newly defined third serotype. Finally, an attempt was made to correlate previously published serotype analysis by neutralization of fluorescent cell-forming units with the results determined by the plaque reduction neutralization assay. PMID:6286487

Wyatt, R G; Greenberg, H B; James, W D; Pittman, A L; Kalica, A R; Flores, J; Chanock, R M; Kapikian, A Z

1982-01-01

172

RTN/Nogo in forming Alzheimer's neuritic plaques.  

PubMed

One of the pathological hallmarks in brains of patients with Alzheimer's disease (AD) is the presence of neuritic plaques, in which amyloid deposits are surrounded by reactive gliosis and dystrophic neurites. Within neuritic plaques, reticulon 3 (RTN3), a homolog of Nogo protein, appears to regulate the formation of both amyloid deposition via negative modulation of BACE1 activity and dystrophic neurites via the formation of RTN3 aggregates. Transgenic mice over-expressing RTN3, but not the other known markers of dystrophic neurites in AD brain, spontaneously develop RTN3-immunoreactive dystrophic neurites. The presence of dystrophic neurites impairs cognition. Blocking abnormal RTN3 aggregation will increase the available RTN3 monomer and is therefore a promising therapeutic strategy for enhancing cognitive function in AD patients. PMID:20144652

Prior, Marguerite; Shi, Qi; Hu, Xiangyou; He, Wanxia; Levey, Allan; Yan, Riqiang

2010-07-01

173

Helicobacter pylori in dental plaque and gastric mucosa: correlation revisited.  

PubMed

Helicobacter pylori (H. pylori) related gastric infection is highly prevalent in developing countries. Prevalence of bacterium in dental plaque from these regions is also reported to be high, but association between simultaneous colonization of H. pylori in both these sites has not been established yet. Aim of this paper is to review possible association between simultaneous oral and gastric H. pylori colonization in dyspeptic patients. Pertinent literature was reviewed and all available evidence collected from Medline and PakMedinet. Studies conducted in the developing world show conflicting results. Some report a positive relation between oral and gastric H. pylori colonization while others deny any association. This may be due to the population sampled or methodology applied. Further studies are recommended to confirm the association between concurrent presence of H. pylori in dental plaque and gastric mucosa of dyspeptic patients using sensitive and specific tests for detection of bacterium in oral samples. PMID:18988394

Chaudhry, Saima; Iqbal, Hafiz Aamer; Khan, Ayyaz Ali; Izhar, Mateen; Butt, Arshad Kamal; Akhter, M Waheed; Izhar, Faisal; Mirza, Kamran Masood

2008-06-01

174

Oral care and pulmonary infection - the importance of plaque scoring  

PubMed Central

Improving the quality of oral hygiene is recognised as an important counter measure for reducing the incidence of ventilator-associated pneumonia amongst critically ill patients. Toothbrushing physically disrupts the dental plaque that acts as a reservoir for pulmonary infection and therefore has the potential to reduce the incidence of ventilator-associated pneumonia. Gu and colleagues performed a systematic review and meta-analysis of oral hygiene with and without a toothbrush and found no difference in the incidence of pneumonia in mechanically ventilated patients. The diagnosis of ventilator-associated pneumonia is prone to bias and future studies of oral care interventions should focus on measures of oral cleanliness such as plaque and gingival scores. Once the optimal strategy for oral hygiene is defined in the critically ill, larger studies focussing on ventilator-associated pneumonia or mortality can be conducted. PMID:23302185

2013-01-01

175

Oral care and pulmonary infection - the importance of plaque scoring.  

PubMed

Improving the quality of oral hygiene is recognised as an important counter measure for reducing the incidence of ventilator-associated pneumonia amongst critically ill patients. Toothbrushing physically disrupts the dental plaque that acts as a reservoir for pulmonary infection and therefore has the potential to reduce the incidence of ventilator-associated pneumonia. Gu and colleagues performed a systematic review and meta-analysis of oral hygiene with and without a toothbrush and found no difference in the incidence of pneumonia in mechanically ventilated patients. The diagnosis of ventilator-associated pneumonia is prone to bias and future studies of oral care interventions should focus on measures of oral cleanliness such as plaque and gingival scores. Once the optimal strategy for oral hygiene is defined in the critically ill, larger studies focussing on ventilator-associated pneumonia or mortality can be conducted. PMID:23302185

Wise, Matt P; Williams, David W

2013-01-01

176

Apollo 11 Commander Armstrong Presents President With Commemorative Plaque  

NASA Technical Reports Server (NTRS)

On June 4, 1974, 5 years after the successful Apollo 11 lunar landing mission, commander Neil Armstrong (right) presented a plaque to U.S. President Richard Milhous Nixon (left) on behalf of all people who had taken part in the space program. In making the presentation, Armstrong said 'Mr. President, you have proclaimed this week to be United States Space week in conjunction with the fifth anniversary of our first successful landing on the Moon. It is my privilege to represent my colleagues, the crewmen of projects Mercury, Gemini, Apollo, and Skylab, and the men and women of NASA, and the hundreds of thousands of Americans from across the land who contributed so mightily to the success of our efforts in space in presenting this plaque which bears the names of each individual who has had the privilege of representing this country' in a space flight. The presentation was made at the California white house in San Clemente.

1974-01-01

177

The Dental Plaque Microbiome in Health and Disease  

PubMed Central

Dental decay is one of the most prevalent chronic diseases worldwide. A variety of factors, including microbial, genetic, immunological, behavioral and environmental, interact to contribute to dental caries onset and development. Previous studies focused on the microbial basis for dental caries have identified species associated with both dental health and disease. The purpose of the current study was to improve our knowledge of the microbial species involved in dental caries and health by performing a comprehensive 16S rDNA profiling of the dental plaque microbiome of both caries-free and caries-active subjects. Analysis of over 50,000 nearly full-length 16S rDNA clones allowed the identification of 1,372 operational taxonomic units (OTUs) in the dental plaque microbiome. Approximately half of the OTUs were common to both caries-free and caries-active microbiomes and present at similar abundance. The majority of differences in OTU’s reflected very low abundance phylotypes. This survey allowed us to define the population structure of the dental plaque microbiome and to identify the microbial signatures associated with dental health and disease. The deep profiling of dental plaque allowed the identification of 87 phylotypes that are over-represented in either caries-free or caries-active subjects. Among these signatures, those associated with dental health outnumbered those associated with dental caries by nearly two-fold. A comparison of this data to other published studies indicate significant heterogeneity in study outcomes and suggest that novel approaches may be required to further define the signatures of dental caries onset and progression. PMID:23520516

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

2013-01-01

178

Simvastatin Attenuates Plaque Inflammation Evaluation by Fluorodeoxyglucose Positron Emission Tomography  

Microsoft Academic Search

METHODS Forty-three consecutive subjects, who underwent 18FDG-PET for cancer screening and had 18 FDG uptakes in the thoracic aorta and\\/or the carotid arteries, were randomized to either statin group receiving simvastatin (n 21) or diet group receiving dietary management only (n 22). The maximum standardized uptake values (SUVs) were measured in individual plaques, and were averaged for analysis of the

Nobuhiro Tahara; Hisashi Kai; Masatoshi Ishibashi; Hiroyuki Nakaura; Hayato Kaida; Kenkichi Baba; Naofumi Hayabuchi; Tsutomu Imaizumi

179

Ichthyosiform Large Plaque Parapsoriasis: Report of a Rare Entity  

PubMed Central

Large plaque parapsoriasis (LPP) is an idiopathic, chronic scaly dermatosis classified within parapsoriasis group of diseases, occurring commonly in middle aged patients of all races and geographic regions. LPP and its variants are closely related to the patch stage of mycosis fungoides. The two types of LPP mostly described are the poikilodermatous and retiform parapsoriasis. We are reporting an ichthyosiform LPP for its rarity. PMID:24082186

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

2013-01-01

180

Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma  

Microsoft Academic Search

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),

P Summanen; I Immonen; T Kivelä; P Tommila; J Heikkonen; A Tarkkanen

1996-01-01

181

Lectin histochemistry of plaques and tangles in Alzheimer's disease  

Microsoft Academic Search

Biotinyl derivatives of several lectins and avidin-horseradish peroxidase were used to study the localization of glycoconjugates in amyloid plaques and in neuritic tangles in brains of patients with Alzheimer's disease (AD), Downs syndrome (DS) and Gerstmann-Sträussler syndrome (GSS). The lectins tested recognize the following residues: ß-d-galactosyl [Ricinus communis agglutinin 120, (RCA-1) and peanut agglutinin, (PNA)]; a-d-galactosyl [Griffonia simplicifolia agglutinin (GSA)];

G. Szumanska; A. W. Vorbrodt; T. I. Mandybur; H. M. Wisniewski

1987-01-01

182

Persistent erythematous plaque after minor trauma in an immunocompromised woman.  

PubMed

Scedosporium apiospermum is a ubiquitous soil fungus with a worldwide distribution. It can cause a wide range of clinical disease, from cutaneous and subcutaneous infections, to pneumonia, brain abscess, and life threatening systemic illness. The diagnosis of cutaneous disease is with biopsy and culture. We discuss the case of an elderly immunocompromised woman who presented with a persistent erythematous plaque on the elbow after minor trauma. A biopsy revealed Scedosporium apiospermum. Treatment usually requires surgical resection in conjunction with antifungal therapy. PMID:22559017

Mays, Rana; Gordon, Rachel; Wilson, Janice M; LaPolla, Whitney J; Sra, Karan K; Madkan, Vandana; Tyring, Stephen K

2012-01-01

183

Amyloid plaque imaging in vivo: current achievement and future prospects  

Microsoft Academic Search

Introduction  Alzheimer’s disease (AD) is a very complex neurodegenerative disorder, the exact cause of which is still not known. The major\\u000a histopathological features, amyloid plaques and neurofibrillary tangles, already described by Alois Alzheimer, have been the\\u000a focus in research for decades. Despite a probable whole cascade of events in the brain leading to impairment of cognition,\\u000a amyloid is still the target

Agneta Nordberg

2008-01-01

184

Perforin Expression in Plaque Psoriasis: An Immunohistochemical Study.  

PubMed

ABSTRACT Psoriasis (PsO) is T-cell-mediated disease resulting from aberrant activation of both innate and adaptive immunity. Perforin is a multi-domain, pore-forming protein. It is located within the cytoplasm of CD 8 cytotoxic T cells (CTLs) and natural killer cells (NK). The aim of this study was to evaluate the immunohistochemical (IHC) expression of perforin in lesional and perilesional skin of chronic plaque psoriatic patient and correlate its expression with the standard clinico-pathological variables. This prospective case-control study was conducted on 50 PsO patients and 30 age- and gender-matched healthy subjects as a control group. There were high-significant differences between lesional and perilesional skin of plaque PsO patients as regards to IHC perforin status and localization (p?plaque PsO. Plaque psoriatic patients with positive perforin expression could be a candidate for a future target therapy to stop the proposed scenario and achieve a therapeutic response. PMID:25222509

Samaka, Rehab Monir; Gaber, Mohamed A; Metwe, Nermin A

2014-09-15

185

Infectious Burden and Carotid Plaque Thickness: The Northern Manhattan Study  

PubMed Central

Background The overall burden of prior infections may contribute to atherosclerosis and stroke risk. We hypothesized that serological evidence of common infections would be associated with carotid plaque thickness in a multi-ethnic cohort. Methods Antibody titers to five common infectious microorganisms (i.e. Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpesvirus 1 and 2) were measured among stroke-free community participants, and a weighted index of infectious burden (IB) was calculated based on Cox models previously derived from for the association of each infection with stroke risk. High-resolution carotid duplex Doppler studies were used to assess maximum carotid plaque thickness (MCPT). Weighted least squares regression was used to measure the association between IB and MCPT after adjusting for other risk factors. Results Serological results for all five infectious organisms were available in 861 participants with MCPT measurements available (mean age 67.2+/?9.6 yrs). Each individual infection was associated with stroke risk after adjusting for other risk factors. The IB index (n=861) had a mean of 1.00 ± standard deviation 0.35, median 1.08. Plaque was present in 52% of participants (mean 0.90+/?1.04 mm). IB was associated with MCPT (adjusted increase in MCPT 0.09 mm, 95% confidence interval 0.03–0.15 mm, per standard deviation increase of IB). Conclusion A quantitative weighted index of infectious burden, derived from the magnitude of association of individual infections with stroke, was associated with carotid plaque thickness in this multi-ethnic cohort. These results lend support to the notion that past or chronic exposure to common infections, perhaps by exacerbating inflammation, contributes to atherosclerosis. Future studies are needed to confirm this hypothesis and to define optimal measures of infectious burden as a vascular risk factor. PMID:20075350

Elkind, Mitchell S. V.; Luna, Jorge M.; Moon, Yeseon Park; Boden-Albala, Bernadette; Liu, Khin M.; Spitalnik, Steven; Rundek, Tanja; Sacco, Ralph L.; Paik, Myunghee C.

2010-01-01

186

Symplekin, a novel type of tight junction plaque protein  

PubMed Central

Using a monoclonal antibody we have identified and cDNA-cloned a novel type of protein localized, by light and electron microscopy, to the plaque associated with the cytoplasmic face of the tight junction- containing zone (zonula occludens) of polar epithelial cells and of Sertoli cells of testis, but absent from the junctions of vascular endothelia. The approximately 3.7-kb mRNA encodes a polypeptide of 1142 amino acids (calculated molecular weight 126.5 kD, pI 6.25), for which the name "symplekin" (from Greek sigma upsilon mu pi lambda epsilon kappa epsilon iota, nu, to tie together, to weave, to be intertwined) is proposed. However, both the mRNA and the protein can also be detected in a wide range of cell types that do not form tight junctions or are even completely devoid of any stable cell contacts. Careful analyses have revealed that the protein occurs in all these diverse cells in the nucleoplasm, and only in those cells forming tight junctions is it recruited, partly but specifically, to the plaque structure of the zonula occludens. We discuss symplekin as a representative of a group of dual residence proteins which occur and probably function in the nucleus as well as in the plaques exclusive for either tight junctions, adherens junctions, or desmosomes. PMID:8769423

1996-01-01

187

Primary Stenting for Complex Atherosclerotic Plaques in Aortic and Iliac Stenoses  

SciTech Connect

Purpose: To evaluate the efficacy of primary stenting for complex atherosclerotic plaques in aortic and iliac stenoses that are not amenable to balloon angioplasty alone. Methods: Nineteen patients with complex atherosclerotic plaques were treated with a Palmaz stent (n= 19), Wallstent (n= 1), Strecker stent (n= 1), or Memotherm stent (n= 1). A total of 22 stenoses presenting with complex plaque morphology including ulcerated plaques, ulcerated plaques with focal aneurysms, plaques with heavy calcification, severely eccentric plaques, plaques with overhanging edge, and plaques with spontaneous dissection were stented. The lesions were in the aorta (n= 1), common iliac artery (n= 19), or external iliac artery (n= 2). Results: Immediate angiography after stent placement revealed restoration of patency of the stented segment. Focal aneurysms and ulcerated areas were occluded in the follow-up angiographies obtained 4-12 weeks after the procedure. In one case with poor distal runoff and multiple complex lesions of the iliac artery, subacute occlusion occurred. Clinical and angiographic follow-up (3-46 months) revealed patency of all other stented segments. Conclusion: Primary stenting is an effective and reliable approach for complex plaques in stenoses. Patency of the arterial segment with a smooth lumen can be created without the risk of acute complications such as distal embolization, dissection, or occlusion.

Onal, Baran; Ilgit, Erhan T.; Yuecel, Cem; Ozbek, Erdal; Vural, Murat; Akpek, Sergin [Department of Radiology, School of Medicine, Gazi University, Besevler, 06510 Ankara (Turkey)

1998-09-15

188

NATURAL HISTORY OF DENTAL PLAQUE ACCUMULATION IN MECHANICALLY VENTILATED ADULTS: A DESCRIPTIVE CORRELATIONAL STUDY  

PubMed Central

Summary Objective The purpose of this study was to describe the pattern of dental plaque accumulation in mechanically ventilated adults. Accumulation of dental plaque and bacterial colonization of the oropharynx is associated with a number of systemic diseases including ventilator associated pneumonia. Research Methodology/Design Data were collected from mechanically ventilated critically ill adults (n=137), enrolled within 24 hours of intubation. Dental plaque, counts of decayed, missing and filled teeth and systemic antibiotic use was assessed on study days 1, 3, 5 and 7. Dental plaque averages per study day, tooth type and tooth location were analyzed. Setting Medical Respiratory, Surgical Trauma and Neuroscience ICU’s of a large tertiary care center in the southeast United States. Results Plaque: All surfaces > 60% plaque coverage from day 1 to day 7; Molars and Premolars contained greatest plaque average >70%. Systemic antibiotic use on day 1 had no significant effect on plaque accumulation on day 3 (p=0.73). Conclusions Patients arrive in critical care units with preexisting oral hygiene issues. Dental plaque tends to accumulate in the posterior teeth (molars and premolars) that may be hard for nurses to visualize and reach; this problem may be exacerbated by endotracheal tubes and other equipment. Knowing accumulation trends of plaque will guide the development of effective oral care protocols. PMID:22014582

Jones, Deborah J.; Munro, Cindy L.; Grap, Mary Jo

2011-01-01

189

Suppressed monocyte recruitment drives macrophage removal from atherosclerotic plaques of Apoe–/– mice during disease regression  

PubMed Central

Experimental models of atherosclerosis suggest that recruitment of monocytes into plaques drives the progression of this chronic inflammatory condition. Cholesterol-lowering therapy leads to plaque stabilization or regression in human atherosclerosis, characterized by reduced macrophage content, but the mechanisms that underlie this reduction are incompletely understood. Mice lacking the gene Apoe (Apoe–/– mice) have high levels of cholesterol and spontaneously develop atherosclerotic lesions. Here, we treated Apoe–/– mice with apoE-encoding adenoviral vectors that induce plaque regression, and investigated whether macrophage removal from plaques during this regression resulted from quantitative alterations in the ability of monocytes to either enter or exit plaques. Within 2 days after apoE complementation, plasma cholesterol was normalized to wild-type levels, and HDL levels were increased 4-fold. Oil red O staining and quantitative mass spectroscopy revealed that esterified cholesterol content was markedly reduced. Plaque macrophage content decreased gradually and was 72% lower than baseline 4 weeks after apoE complementation. Importantly, this reduction in macrophages did not involve migratory egress from plaques or CCR7, a mediator of leukocyte emigration. Instead, marked suppression of monocyte recruitment coupled with a stable rate of apoptosis accounted for loss of plaque macrophages. These data suggest that therapies to inhibit monocyte recruitment to plaques may constitute a more viable strategy to reduce plaque macrophage burden than attempts to promote migratory egress. PMID:21505265

Potteaux, Stephane; Gautier, Emmanuel L.; Hutchison, Susan B.; van Rooijen, Nico; Rader, Daniel J.; Thomas, Michael J.; Sorci-Thomas, Mary G.; Randolph, Gwendalyn J.

2011-01-01

190

3D MRI-based multicomponent FSI models for atherosclerotic plaques.  

PubMed

A three-dimensional (3D) MRI-based computational model with multicomponent plaque structure and fluid-structure interactions (FSI) is introduced to perform mechanical analysis for human atherosclerotic plaques and identify critical flow and stress/strain conditions which may be related to plaque rupture. Three-dimensional geometry of a human carotid plaque was reconstructed from 3D MR images and computational mesh was generated using Visualization Toolkit. Both the artery wall and the plaque components were assumed to be hyperelastic, isotropic, incompressible, and homogeneous. The flow was assumed to be laminar, Newtonian, viscous, and incompressible. The fully coupled fluid and structure models were solved by ADINA, a well-tested finite element package. Results from two-dimensional (2D) and 3D models, based on ex vivo MRI and histological images (HI), with different component sizes and plaque cap thickness, under different pressure and axial stretch conditions, were obtained and compared. Our results indicate that large lipid pools and thin plaque caps are associated with both extreme maximum (stretch) and minimum (compression when negative) stress/strain levels. Large cyclic stress/strain variations in the plaque under pulsating pressure were observed which may lead to artery fatigue and possible plaque rupture. Large-scale patient studies are needed to validate the computational findings for possible plaque vulnerability assessment and rupture predictions. PMID:15298432

Tang, Dalin; Yang, Chun; Zheng, Jie; Woodard, Pamela K; Sicard, Gregorio A; Saffitz, Jeffrey E; Yuan, Chun

2004-07-01

191

Spotty calcification and plaque vulnerability in vivo: frequency-domain optical coherence tomography analysis  

PubMed Central

Background Spotty calcification is a morphological characteristic of a vulnerable plaque phenotype. While this calcium pattern is considered an active process, promoted by inflammation, it is unknown whether spotty calcification associates with development of microstructures observed in vulnerable plaques. As frequency-domain optical coherence tomography (FD-OCT) enables visualization of microstructures associated with plaque vulnerability, we investigated the association between spotty calcification and plaque microstructures by using FD-OCT. Methods A total of 300 patients with stable coronary artery disease (CAD), having clinical indication for percutaneous coronary intervention (PCI), were analyzed. Totally 280 non-culprit lipid plaques within the target vessel requiring PCI were evaluated by FD-OCT. Spotty calcification was defined as a presence of lesion <4 mm in length, containing an arc of calcification <90° on FD-OCT. Plaque microstructures were compared in non-culprit lipid-rich plaques with and without spotty calcification. Results Spotty calcification was observed in 39.6% of non-culprit lipid-rich plaques, with 30.6% of these plaques demonstrating multiple spotty calcifications. Plaques containing spotty calcification exhibited a greater lipid index (= averaged lipid arc × lipid length); 1,511.8±1,522.3 vs. 815.2±1,040.3 mm°, P<0.0001), thinner fibrous caps (89.0±31.6 vs. 136.5±32.5 µm, P=0.002) and a higher prevalence of microchannels (45.9% vs. 17.7%, P=0.007). A significant association was observed between the number of spotty calcifications per plaque and fibrous cap thickness (r=-0.40, P=0.006). Increased number of spotty calcification was also associated with a higher prevalence of microchannel within plaques (P=0.01). Conclusions In patients with stable CAD requiring PCI, the presence of spotty calcification imaged by FD-OCT was associated with features of greater plaque vulnerability. PMID:25610803

Puri, Rishi; Hammadah, Muhammad; Duggal, Bhanu; Uno, Kiyoko; Kapadia, Samir R.; Tuzcu, E. Murat; Nissen, Steven E.; Nicholls, Stephen J.

2014-01-01

192

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

PubMed Central

Calcification is a marked pathological component in carotid artery plaque. Studies have suggested that calcification may induce regions of high stress concentrations therefore increasing the potential for rupture. However, the mechanical behaviour of the plaque under the influence of calcification is not fully understood. A method of accurately characterising the calcification coupled with the associated mechanical plaque properties is needed to better understand the impact of calcification on the mechanical behaviour of the plaque during minimally invasive treatments. This study proposes a comparison of biochemical and structural characterisation methods of the calcification in carotid plaque specimens to identify plaque mechanical behaviour. Biochemical analysis, by Fourier Transform Infrared (FTIR) spectroscopy, was used to identify the key components, including calcification, in each plaque sample. However, FTIR has a finite penetration depth which may limit the accuracy of the calcification measurement. Therefore, this FTIR analysis was coupled with the identification of the calcification inclusions located internally in the plaque specimen using micro x-ray computed tomography (?X-CT) which measures the calcification volume fraction (CVF) to total tissue content. The tissue characterisation processes were then applied to the mechanical material plaque properties acquired from experimental circumferential loading of human carotid plaque specimen for comparison of the methods. FTIR characterised the degree of plaque progression by identifying the functional groups associated with lipid, collagen and calcification in each specimen. This identified a negative relationship between stiffness and 'lipid to collagen' and 'calcification to collagen' ratios. However, ?X-CT results suggest that CVF measurements relate to overall mechanical stiffness, while peak circumferential strength values may be dependent on specific calcification geometries. This study demonstrates the need to fully characterise the calcification structure of the plaque tissue and that a combination of FTIR and ?X-CT provides the necessary information to fully understand the mechanical behaviour of the plaque tissue. PMID:25602176

2015-01-01

193

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

PubMed Central

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

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

2013-01-01

194

Assessment of atherosclerotic plaque burden with an elastin-specific magnetic resonance contrast agent.  

PubMed

Atherosclerosis and its consequences remain the main cause of mortality in industrialized and developing nations. Plaque burden and progression have been shown to be independent predictors for future cardiac events by intravascular ultrasound. Routine prospective imaging is hampered by the invasive nature of intravascular ultrasound. A noninvasive technique would therefore be more suitable for screening of atherosclerosis in large populations. Here we introduce an elastin-specific magnetic resonance contrast agent (ESMA) for noninvasive quantification of plaque burden in a mouse model of atherosclerosis. The strong signal provided by ESMA allows for imaging with high spatial resolution, resulting in accurate assessment of plaque burden. Additionally, plaque characterization by quantifying intraplaque elastin content using signal intensity measurements is possible. Changes in elastin content and the high abundance of elastin during plaque development, in combination with the imaging properties of ESMA, provide potential for noninvasive assessment of plaque burden by molecular magnetic resonance imaging (MRI). PMID:21336283

Makowski, Marcus R; Wiethoff, Andrea J; Blume, Ulrike; Cuello, Friederike; Warley, Alice; Jansen, Christian H P; Nagel, Eike; Razavi, Reza; Onthank, David C; Cesati, Richard R; Marber, Michael S; Schaeffter, Tobias; Smith, Alberto; Robinson, Simon P; Botnar, René M

2011-03-01

195

Contemporary invasive imaging modalities that identify and risk-stratify coronary plaques at risk of rupture.  

PubMed

Atherosclerotic plaque rupture is responsible for the majority of myocardial infarctions, with ruptured plaques exhibiting specific morphological features, including large lipid cores, thinner overlying fibrous caps and micro-calcifications. Contemporary imaging modalities are increasingly able to characterize plaques, potentially leading to the identification of precursor lesions that are at high risk of rupture. Observational studies using invasive imaging consistently find that plaques responsible for an acute coronary event display these high-risk morphological features, and recent prospective imaging studies have now established links between baseline plaque characteristics and future cardiovascular events. Despite these promising advances, subsequent overall event rates remain too low for clinical utility. Novel technologies are now required to refine and improve our ability to identify and risk-stratify lesions at risk of rupture, if plaque-based risk evaluation is ever to become reality. PMID:25470576

Brown, Adam J; Costopoulos, Charis; West, Nick Ej; Bennett, Martin R

2015-01-01

196

Effect of Sucralose in Coffee on Plaque pH in Human Subjects  

Microsoft Academic Search

Our earlier work demonstrated that the sweetener sucralose, C12H19CI3O8, mixed with water had no effect on intraoral plaque pH. The current study compared the effect on resting plaque pH of sucralose to sucrose when these sweeteners were used in hot coffee at equivalent sweetness levels. Twelve subjects with an identified acidogenic plaque were tested at dicrete sessions, using coffee as

Louis M. Steinberg; Folarin Odusola; Irwin D. Mandel

1996-01-01

197

Increased expression of endothelial lipase in symptomatic and unstable carotid plaques  

Microsoft Academic Search

The aim of this study was to evaluate endothelial lipase (EL) protein expression in advanced human carotid artery plaques\\u000a (HCAP) with regard to plaque (in)stability and the incidence of symptoms. HCAP were collected from 66 patients undergoing\\u000a carotid endarterectomy (CEA). The degree of plaque (in)stability was estimated by ultrasound and histology. In HCAP sections,\\u000a EL expression was determined by immunostaining

Matias Trbuši?; Monika Riederer; Majda Vu?i?; Ivo Lovri?evi?; Božo Krušlin; Martin Gauster; Sonja Mohrenz; Andrea Berghold; Beate Tiran; Vesna Degoricija; Saša Frank

198

Image quality evaluation of motion-contaminated calcified plaques in cardiac CT  

Microsoft Academic Search

An automated method for evaluating the image quality of motion-contaminated calcified plaques in non contrast-enhanced cardiac CT was developed. This method consisted of using the rapid phase-correlated ROI (RP-ROI) reconstruction algorithm for generating a 4D series of calcified plaque images, and then extracting phase-correlated dynamic, morphological, and intensity-based features of the plaques. Velocity-based linear regression (VLR), multiple linear regression (MLR),

Martin King; Maryellen Giger; Kenji Suzuki; Xiaochuan Pan

2007-01-01

199

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

200

Evaluation of the Radiolabeled Boronic Acid-Based FAP Inhibitor MIP-1232 for Atherosclerotic Plaque Imaging.  

PubMed

Research towards the non-invasive imaging of atherosclerotic plaques is of high clinical priority as early recognition of vulnerable plaques may reduce the incidence of cardiovascular events. The fibroblast activation protein alpha (FAP) was recently proposed as inflammation-induced protease involved in the process of plaque vulnerability. In this study, FAP mRNA and protein levels were investigated by quantitative polymerase chain reaction and immunohistochemistry, respectively, in human endarterectomized carotid plaques. A published boronic-acid based FAP inhibitor, MIP-1232, was synthetized and radiolabeled with iodine-125. The potential of this radiotracer to image plaques was evaluated by in vitro autoradiography with human carotid plaques. Specificity was assessed with a xenograft with high and one with low FAP level, grown in mice. Target expression analyses revealed a moderately higher protein level in atherosclerotic plaques than normal arteries correlating with plaque vulnerability. No difference in expression was determined on mRNA level. The radiotracer was successfully produced and accumulated strongly in the FAP-positive SK-Mel-187 melanoma xenograft in vitro while accumulation was negligible in an NCI-H69 xenograft with low FAP levels. Binding of the tracer to endarterectomized tissue was similar in plaques and normal arteries, hampering its use for atherosclerosis imaging. PMID:25633335

Meletta, Romana; Müller Herde, Adrienne; Chiotellis, Aristeidis; Isa, Malsor; Rancic, Zoran; Borel, Nicole; Ametamey, Simon M; Krämer, Stefanie D; Schibli, Roger

2015-01-01

201

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. PMID:25278976

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

2014-01-01

202

Automatic segmentation of amyloid plaques in MR images using unsupervised SVM  

PubMed Central

Deposition of the ?-amyloid peptide (A?) is an important pathological hallmark of Alzheimer’s disease (AD). However, reliable quantification of amyloid plaques in both human and animal brains remains a challenge. We present here a novel automatic plaque segmentation algorithm based on the intrinsic MR signal characteristics of plaques. This algorithm identifies plaque candidates in MR data by using watershed transform, which extracts regions with low intensities completely surrounded by higher intensity neighbors. These candidates are classified as plaque or non-plaque by an unsupervised learning method using features derived from the MR data intensity. The algorithm performance is validated by comparison with histology. We also demonstrate the algorithm’s ability to detect age-related changes in plaque load ex vivo in 5×FAD APP transgenic mice. To our knowledge, this work represents the first quantitative method for characterizing amyloid plaques in MRI data. The proposed method can be used to describe the spatio-temporal progression of amyloid deposition, which is necessary for understanding the evolution of plaque pathology in mouse models of AD and to evaluate the efficacy of emergent amyloid-targeting therapies in preclinical trials. PMID:22189675

Iordanescu, Gheorghe; Venkatasubramanian, Palamadai N.; Wyrwicz, Alice M.

2011-01-01

203

Comparison of strain rates of dart impacted plaques and pendulum impacted bumpers  

SciTech Connect

The difference in strain rates prevailing during pendulum impact of bumpers versus high speed dart impact of plaques was investigated. Uni-axial strain gages were applied to the tension side of the plaques and bumpers directly opposite the point of impact. The plaques were impacted with an instrumented high rate dart impact tester and the bumpers impacted with a full scale bumper pendulum impact tester. Theoretical calculations and actual strain rate data support the conclusion that the strain rate of a plaque during dart impact significantly exceeds that of bumper strain rate during pendulum impact.

Scammell, K.L.

1987-01-01

204

Analyzer-based phase-contrast x-ray imaging of carotid plaque microstructure  

PubMed Central

BACKGROUND Plaque vulnerability depends, in part, on composition. Imaging techniques are needed that can aid the prediction of plaque stability. High-contrast images of soft-tissue structure have been obtained with x-ray phase-contrast (PC) imaging. This research investigates multiple image radiography (MIR), an x-ray PC imaging technique, for evaluation of human carotid artery plaques. METHODS Carotid plaques were imaged with ultrasound and subsequently excised and formalin fixed. MIR imaging was performed. By using synchrotron radiation, conventional radiographs were acquired for comparison. Image texture measures were computed for soft-tissue regions of the plaques. RESULTS Ultrasound evaluation identified plaques as homogeneous without calcifications. MIR images revealed complex heterogeneous structure with multiple microcalcifications consistent with histology, and possessed more image texture in specific regions than conventional radiographs (P < .05). MIR refraction images allowed imaging of the geometric structure of tissue interfaces within the plaques, while scatter images contained more texture in soft-tissue regions than absorption or refraction images. CONCLUSIONS X-ray PC imaging better depicts plaque soft-tissue heterogeneity than ultrasound or conventional radiographs. MIR imaging technique should be investigated further as a viable imaging technique to identify high-risk plaques. PMID:23140828

Appel, Alyssa A.; Chou, Cheng-Ying; Greisler, Howard P.; Larson, Jeffery C.; Vasireddi, Sunil; Zhong, Zhong; Anastasio, Mark A.; Brey, Eric M.

2012-01-01

205

Milia en plaque of the nose: report of a case and successful treatment with topical tretinoin.  

PubMed

Milia are benign, superficial keratinaceous cysts that present as fine, small white papules. Milia en plaque is a rare, challenging-to-treat variant most often seen in the posterior auricular region. A total of 9 cases of milia en plaque have been reported in the pediatric literature to date. We report a case of milia en plaque of the nose in a 7-year-old boy, a novel site of involvement in the pediatric population, and successful treatment with the use of topical tretinoin. Topical retinoids offer an effective treatment option for the management of milia en plaque in the pediatric population. PMID:24709934

Nambudiri, Vinod E; Habib, Nancy; Arndt, Kenneth A; Kane, Kay S

2014-05-01

206

Biocompatibility of orthodontic bands following exposure to dental plaque  

Microsoft Academic Search

Objective  The aim of this study was to assess the biocompatibility of orthodontic bands following exposure to the human oral environment.\\u000a \\u000a \\u000a \\u000a Methods  Cell adherence and cell morphology of gingival fibroblasts grown on 32 orthodontic bands were tested. The bands were in place\\u000a intraorally for 6 to 37 months.\\u000a \\u000a \\u000a \\u000a \\u000a Results  We observed cell adherence in 76% of the previously plaque-free surfaces. Cell morphology was 50%

Sandra Hornikel; Christina Erbe; Irene Schmidtmann; Heiner Wehrbein

2011-01-01

207

Characteristics of intact and ruptured atherosclerotic plaques in brachiocephalic arteries of apolipoprotein E knockout mice.  

PubMed

The brachiocephalic arteries of fat-fed apolipoprotein E knockout mice develop plaques that frequently rupture and form luminal thromboses. The morphological characteristics of plaques without evidence of instability or with healed previous ruptures (intact) and vessels with acutely ruptured plaques (ruptured) have now been defined, to understand the process of plaque destabilization in more detail. Ninety-eight apolipoprotein E knockout mice were fed a diet supplemented with 21% lard and 0.15% cholesterol, for 5 to 59 weeks. Of these 98 mice, 51 had an acutely ruptured plaque in the brachiocephalic artery. Ruptured and intact plaques differed in terms of plaque cross-sectional area (intact, 0.109+/-0.016 mm2; ruptured, 0.192+/-0.009 mm2; P=0.0005), luminal occlusion (intact, 35.3+/-3.3%; ruptured, 57.7+/-1.9%; P<0.0001), the number of buried caps within the lesion (intact, 1.06+/-0.12; ruptured, 2.66+/-0.16; P<0.0001), fibrous cap thickness (intact, 4.7+/-0.6 microm; ruptured, 2.0+/-0.3 microm; P=0.0004), and lipid fractional volume (intact, 35.9+/-3.0%; ruptured, 50.7+/-2.2%; P=0.0019). This study confirms that plaque rupture is a frequent occurrence in the brachiocephalic arteries of apolipoprotein E knockout mice on a high-fat diet. The data also show that ruptured plaques in these mice show many of the characteristics of vulnerable plaques in humans. This supports the use of this model in studies of the mechanisms and therapy of plaque rupture. PMID:12006391

Williams, Helen; Johnson, Jason Lee; Carson, Kevin George Stephen; Jackson, Christopher Langdale

2002-05-01

208

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

209

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

210

Symptomatic carotid atherosclerotic disease: correlations between plaque composition and ipsilateral stroke risk  

PubMed Central

BACKGROUND AND PURPOSE For symptomatic patients with carotid artery stenosis the risk-benefit for surgical intervention may vary among patient groups. Various modalities of plaque imaging have been promoted as potential tools for additional risk stratification, particularly in patients with moderate stenosis. However, it remains uncertain to what extent carotid plaque components predict risk of future ipsilateral ischaemic stroke. METHODS In two large atherosclerotic carotid plaque biobank studies, we related histological characteristics of 1640 carotid plaques with a validated risk model for the prediction of individual 1- and 5-year stroke risk. RESULTS No significant heterogeneity between the studies was found. Predicted 5-year stroke risk (top versus bottom quartile) was related to plaque thrombus (OR=1.42, 95%CI 1.11-1.89, p=0.02), fibrous content (0.65, 0.49-0.87, p=0.004), macrophage infiltration (1.41, 1.05-1.90, p=0.02), high micro-vessel density (1.49, 1.05-2.11, p=0.03), and overall plaque instability (1.40, 1.05-1.87,p=0.02). This association was not observed for cap thickness, calcification, intra-plaque haemorrhage, or lymphocyte infiltration. Plaques removed within 30-days of most recent symptomatic event were most strongly correlated with predicted stroke risk. CONCLUSIONS Features of ‘the vulnerable carotid plaque’ including plaque thrombus, low fibrous content, macrophage infiltration and microvessel density correlate with predicted stroke risk. This study provides a basis for plaque imaging studies focused on stroke risk stratification. PMID:25477221

Rothwell, Peter M; Redgrave, Jessica N; Moll, Frans L; de Vries, Jean-Paul PM; de Kleijn, Dominique PV; den Ruijter, Hester M; de Borst, Gert Jan; Pasterkamp, Gerard

2014-01-01

211

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

212

An automated approach to seed assignment for eye plaque brachytherapy  

NASA Astrophysics Data System (ADS)

Episcleral plaques are commonly used for the treatment of ocular tumours such as choroidal melanoma. Treatment planning involves the assignment of seeds to slots on the plaque to achieve a desired dose rate distribution. Seed assignment is rather straightforward if seeds are ordered on demand. However, the assignment task becomes tedious and laborious if the seeds have to be chosen from an existing stock of seeds with different activities. To date, this task has usually been performed by a human planner through trial and error. An algorithm has been developed to automate the task of seed assignment using a mixed-integer programming method. We also explore ways to simplify the problem such that the method becomes practical in most facilities. We have tested the method on three randomly chosen clinical cases from our past records, to show that the algorithm could yield solutions within a shorter time frame and with less deviation from the desired dose rate distributions, as compared with the solutions from a human counterpart.

San Koh, Tong; Yeung, Ivan; Tong, Shidong

2000-07-01

213

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

214

Effect of Amine Fluoride\\/Stannous Fluoride-Containing Toothpaste and Mouthrinsings on Dental Plaque, Gingivitis, Plaque and Enamel F–– Accumulation  

Microsoft Academic Search

The aim of the study was to assess the effect of an amine fluoride\\/stannous fluoride toothpaste and mouthwash on dental plaque and gingivitis, plaque F–– accumulation, F–– content and acid solubility of dental enamel. Participants in the 12-week double-blind study were 92 schoolchildren, with a mean age of 12.4 years, randomly distributed to four groups: (1) AmF\\/SnF2 toothpaste, (2) placebo

J. Bánóczy; J. Szöke; P. Kertész; Zs. Tóth; P. Zimmermann; Z. Gintner

1989-01-01

215

Fractal dimension estimation of carotid atherosclerotic plaques from B-mode ultrasound: a pilot study  

Microsoft Academic Search

In this paper, a pilot study regarding carotid atherosclerotic plaque instability using B-mode ultrasound (US) images was carried out. The fractal dimension of plaques obtained from ten symptomatic subjects (i.e., subjects having experienced neurological symptoms) as well as from nine asymptomatic subjects, was estimated using a novel method, called the kth nearest neighbour (KNN) method. The results indicated a significant

Pantelis Asvestas; Spyretta Golemati; George K. Matsopoulos; Konstantina S. Nikita; Andrew N. Nicolaides

2002-01-01

216

FRACTAL DIMENSION ESTIMATION OF CAROTID ATHEROSCLEROTIC PLAQUES FROM B-MODE ULTRASOUND: A PILOT STUDY  

Microsoft Academic Search

In this paper, a pilot study regarding carotid atherosclerotic plaque instability using B-mode ultra- sound (US) images was carried out. The fractal dimension of plaques obtained from ten symptomatic subjects (i.e., subjects having experienced neurological symptoms) as well as from nine asymptomatic subjects, was estimated using a novel method, called the kth nearest neighbour (KNN) method. The results indicated a

PANTELIS ASVESTAS; SPYRETTA GOLEMATI; GEORGE K. MATSOPOULOS; KONSTANTINA S. NIKITA; ANDREW N. NICOLAIDES

2002-01-01

217

Doxycycline Stabilizes Vulnerable Plaque via Inhibiting Matrix Metalloproteinases and Attenuating Inflammation in Rabbits  

Microsoft Academic Search

Enhanced matrix metalloproteinases (MMPs) activity is implicated in the process of atherosclerotic plaque instability. We hypothesized that doxycycline, a broad MMPs inhibitor, was as effective as simvastatin in reducing the incidence of plaque disruption. Thirty rabbits underwent aortic balloon injury and were fed a high-fat diet for 20 weeks. At the end of week 8, the rabbits were divided into

Mei Dong; Lin Zhong; Wen Qiang Chen; Xiao Ping Ji; Mei Zhang; Yu Xia Zhao; Li Li; Gui Hua Yao; Peng Fei Zhang; Cheng Zhang; Lei Zhang; Yun Zhang

2012-01-01

218

EFFICACY OF BARBERRY AQUEOUS EXTRACTS DENTAL GEL ON CONTROL OF PLAQUE AND GINGIVITIS  

Microsoft Academic Search

Herbal extracts have been successfully used in dentistry as tooth cleaning and antimicrobial plaque agents. The aim of this study was to evaluate the clinical effects of a dental gel containing barberry extracts (from Berberis vulgaris) on gingivitis and microbial plaque control. A double blind clinical trial study was conducted in a dormitory on 45 boys aged 11-12 years having

A. Makarem; N. Khalili; R. Asodeh

219

Dynamics of Plaque Formation in Alzheimer's Disease B. Urbanc,* L. Cruz,* S. V. Buldyrev,* S. Havlin,*#  

E-print Network

Dynamics of Plaque Formation in Alzheimer's Disease B. Urbanc,* L. Cruz,* S. V. Buldyrev,* S and their time evolution. INTRODUCTION Alzheimer's disease (AD) is a progressive neurodegenera- tive disorder, Boston, Massachusetts 02114 USA ABSTRACT Plaques that form in the brains of Alzheimer patients are made

Buldyrev, Sergey

220

Lysophosphatidic acid triggers mast cell-driven atherosclerotic plaque destabilization by increasing vascular inflammation[S  

PubMed Central

Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by modulating mast cell function. We here show by an imaging mass spectrometry approach that several LPA species are present in atherosclerotic plaques. Subsequently, we demonstrate that LPA is a potent mast cell activator which, unlike other triggers, favors release of tryptase. Local perivascular administration of LPA to an atherosclerotic carotid artery segment increases the activation status of perivascular mast cells and promotes intraplaque hemorrhage and macrophage recruitment without impacting plaque cell apoptosis. The mast cell stabilizer cromolyn could prevent intraplaque hemorrhage elicited by LPA-mediated mast cell activation. Finally, the involvement of mast cells in these events was further emphasized by the lack of effect of perivascular LPA administration in mast cell deficient animals. We demonstrate that increased accumulation of LPA in plaques induces perivascular mast cell activation and in this way contributes to plaque destabilization in vivo. This study points to local LPA availability as an important factor in atherosclerotic plaque stability. PMID:23396975

Bot, Martine; de Jager, Saskia C. A.; MacAleese, Luke; Lagraauw, H. Maxime; van Berkel, Theo J. C.; Quax, Paul H. A.; Kuiper, Johan; Heeren, Ron M. A.; Biessen, Erik A. L.; Bot, Ilze

2013-01-01

221

Effect of chlorhexidine gluconate mouth wash on the plaque microflora in children using intra oral appliances.  

PubMed

The effect of 0.2% chlorhexidine mouth wash (Hexidine) on the plaque microflora was evaluated on children wearing intra oral removable appliances. Plaque samples were collected from the enamel sections, both primary and permanent, mounted on the removable appliances. These appliances were worn by 12 children for one week. Plaque was allowed to accumulate on the in situ test sites and on the adjacent natural dentition. At the end of the experimental period the plaque microflora associated with the enamel sections were compared with that obtained from lingual and interproximal areas of the lower molar teeth. It was also compared with a control group of 12 children without an appliance. In addition, the effect of 0.2% chlorhexidine mouth wash on the plaque microflora for the next 14 days was also determined on both the groups. Although some quantitative difference was found between the proportion of isolates obtained from the different enamel surfaces, it was not statistically significant. There was a statistically significant increase in the isolates of plaque microflora after the insertion of removable appliance in children which decreased significantly with the use of 10 ml of 0.2% chlorhexidine gluconate mouth wash twice a day. The study indicates that the primary and permanent tooth specimens mounted on the intra-oral device collected plaque microflora similar to that present on the adjacent natural dentition and that chlorhexidine gluconate mouth wash therapy is effective in reducing plaque microflora in children with removable appliances. PMID:8634191

Amitha, H; Munshi, A K

1995-01-01

222

Carotid plaque burden predicts cardiovascular death: A prospective, population-based cohort study  

Microsoft Academic Search

Background: Ultrasonographic assessment of plaque in the carotid artery is a recognized non-invasive technique to reveal atherosclerosis. The aim of this study was to investigate whether plaque in the carotid arteries predicted cardiovascular (CV) death independently of traditional CV risk factors in the general population.Methods: In 1993 to 1994, a random sample of 2651 men and women, aged 41, 51,

Marina K. Christensen; Michael H. Olsen; Lars T. Jensen; Hans Ibsen

2005-01-01

223

18F-labeled styrylpyridines as PET agents for amyloid plaque imaging  

Microsoft Academic Search

Positron emission tomography (PET) imaging of ?-amyloid (A?) plaques in the brain is a potentially valuable tool for studying the pathophysiology of Alzheimer's disease (AD). It may also be applicable for measuring the effectiveness of therapeutic drugs aimed at lowering A? plaques in the brain. We have successfully reported a series of 18F-labeled fluoropegylated stilbenes for PET imaging studies. Encouraging

Wei Zhang; Mei-Ping Kung; Shunichi Oya; Catherine Hou; Hank F. Kung

2007-01-01

224

18F-Labeled benzylideneaniline derivatives as new ligands for ?-amyloid plaque imaging in Alzheimer's disease  

Microsoft Academic Search

IntroductionNoninvasive early detection of ?-amyloid (A?) plaques might be useful for the treatment of patients with Alzheimer's disease (AD). We herein describe the synthesis of 18F-labeled benzylideneaniline derivatives using a novel labeling approach for imaging A? plaques in AD patients.

Hak Jeong Lee; Jae Min Jeong; Ganesha Rai; Yun-Sang Lee; Young Soo Chang; Young Ju Kim; Hyung Woo Kim; Dong Soo Lee; Jung Key Chung; Inhee Mook-Jung; Myung Chul Lee

2009-01-01

225

Segmentation of wall and plaque in in vitro vascular MR images  

Microsoft Academic Search

Atherosclerosis leads to heart attack and stroke, which are major killers in the western world. These cardiovascular events frequently result from local rupture of vulnerable atherosclerotic plaque. Non-invasive assessment of plaque vulnerability would dramatically change the way in which atherosclerotic disease is diagnosed, monitored, and treated. In this paper, we report a computerized method for segmentation of arterial wall layers

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

2003-01-01

226

Segmentation of wall and plaque in in vitro vascular MR images  

Microsoft Academic Search

Atherosclerosis leads to heart attack and stroke, which are major killers in the western world. These cardiovascular events frequently result from local rupture of vulnerable atherosclerotic plaque. Non- invasive assessment of plaque vulnerability would dramatically change the way in which atherosclerotic disease is diagnosed, monitored, and treated. In this paper, we report a computerized method for seg- mentation of arterial

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

2003-01-01

227

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

228

Clustering of Risk Factors Increases the Incidence of Echolucent Carotid Plaque in Stroke Patients  

Microsoft Academic Search

Background: The purpose of this study was to assess the influence of clusters of risk factors on the incidence of echolucent carotid plaque in stroke patients. Methods: A retrospective analysis of 413 stroke patients who had undergone carotid ultrasonography was performed. High-resolution B-mode ultrasonography was used to evaluate the characteristics of carotid plaque. We investigated the relationships between the incidence

Kazuo Yamashiro; Terubumi Watanabe; Ryota Tanaka; Miki Komine-Kobayashi; Yoshikuni Mizuno; Takao Urabe

2006-01-01

229

Matrix-Metalloproteinases as Imaging Targets for Inflammatory Activity in Atherosclerotic Plaques  

Microsoft Academic Search

Cardiovascular events such as myocardial infarction or stroke resulting from atherosclerosis still account for the majority of deaths worldwide. New imaging approaches focusing on the vi- sualization of inflammation in the vessel wall may emerge as toolsforindividualizedriskassessmentandpreventionofevents. Enzymes such as matrix-metalloproteinases (MMPs) are in- volved in several steps in plaque progression driving plaques into vulnerable, rupture-prone states. Targeting of MMPs

Michael Schafers; Otmar Schober; Sven Hermann

2010-01-01

230

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

231

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

232

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

233

Coronary Plaque Boundary Enhancement in IVUS Image by Using a Modified Perona-Malik Diffusion Filter  

PubMed Central

We propose a modified Perona-Malik diffusion (PMD) filter to enhance a coronary plaque boundary by considering the conditions peculiar to an intravascular ultrasound (IVUS) image. The IVUS image is commonly used for a diagnosis of acute coronary syndrome (ACS). The IVUS image is however very grainy due to heavy speckle noise. When the normal PMD filter is applied for speckle noise reduction in the IVUS image, the coronary plaque boundary becomes vague. For this problem, we propose a modified PMD filter which is designed in special reference to the coronary plaque boundary detection. It can then not only reduce the speckle noise but also enhance clearly the coronary plaque boundary. After applying the modified PMD filter to the IVUS image, the coronary plaque boundaries are successfully detected further by applying the Takagi-Sugeno fuzzy model. The accuracy of the proposed method has been confirmed numerically by the experiments. PMID:25506357

Anam, S.; Uchino, E.; Suetake, N.

2014-01-01

234

A review of factors influencing the incidence and severity of plaque-induced gingivitis.  

PubMed

An individual variation in the gingival inflammatory response to the dental biofilm has been demonstrated. This variability can be observed between individuals with neither quantitative nor qualitative differences in plaque accumulation. The reported significant differences in gingival inflammatory response under quantitatively and/or qualitatively almost identical bacterial challenge suggest that the gingival response to plaque accumulation may be an individual trait, possibly genetic in origin. The most recent classification of periodontal diseases acknowledges that the clinical expression of plaque-induced gingival inflammation can be substantially modified by systemic factors, either inherent to the host or related to environmental influences. The aim of the present literature review is to describe (i) the factors influencing the development of plaque-induced gingivitis as well as (ii) those metabolic, environmental and systemic factors which have a direct impact on the etiopathogenetic pathway of plaque-induced gingivitis, thus altering the nature or course of the gingival inflammatory response to dental biofilm. PMID:23828258

Trombelli, L; Farina, R

2013-06-01

235

Microwave radiometry: a new non-invasive method for the detection of vulnerable plaque  

PubMed Central

Atherosclerosis and its consequences are the most rapidly growing vascular pathology, with myocardial infarction and ischemic cerebrovascular accident to remain a major cause of premature morbidity and death. In order to detect the morphological and functional characteristics of the vulnerable plaques, new imaging modalities have been developed. Intravascular thermography (IVT) is an invasive method, which provides information on the identification of the high-risk atheromatic plaques in coronary arteries. However, the invasive character of IVT excludes the method from primary prevention. Microwave radiometry (MR) is a new non-invasive method, which detects with high accuracy relative changes of temperature in human tissues whereas this thermal heterogeneity is indicative of inflammatory atherosclerotic plaque. Both experimental and clinical studies have proved the effectiveness of MR in detecting vulnerable plaque whereas recent studies have also revealed its association with plaque neoangiogenesis as assessed by contrast enhanced carotid ultrasound (CEUS). PMID:24282729

Synetos, Andreas; Nikolaou, Charalampia; Stathogiannis, Konstantinos; Tsiamis, Eleftherios; Stefanadis, Christodoulos

2012-01-01

236

The influence of inaccuracies in carotid MRI segmentation on atherosclerotic plaque stress computations.  

PubMed

Biomechanical finite element analysis (FEA) based on in vivo carotid magnetic resonance imaging (MRI) can be used to assess carotid plaque vulnerability noninvasively by computing peak cap stress. However, the accuracy of MRI plaque segmentation and the influence this has on FEA has remained unreported due to the lack of a reliable submillimeter ground truth. In this study, we quantify this influence using novel numerical simulations of carotid MRI. Histological sections from carotid plaques from 12 patients were used to create 33 ground truth plaque models. These models were subjected to numerical computer simulations of a currently used clinically applied 3.0?T T1-weighted black-blood carotid MRI protocol (in-plane acquisition voxel size of 0.62?×?0.62 mm2) to generate simulated in vivo MR images from a known underlying ground truth. The simulated images were manually segmented by three MRI readers. FEA models based on the MRI segmentations were compared with the FEA models based on the ground truth. MRI-based FEA model peak cap stress was consistently underestimated, but still correlated (R) moderately with the ground truth stress: R?=?0.71, R?=?0.47, and R?=?0.76 for the three MRI readers respectively (p?plaque stretch was underestimated as well. The peak cap stress in thick-cap, low stress plaques was substantially more accurately and precisely predicted (error of -12?±?44?kPa) than the peak cap stress in plaques with caps thinner than the acquisition voxel size (error of -177?±?168?kPa). For reliable MRI-based FEA to compute the peak cap stress of carotid plaques with thin caps, the current clinically used in-plane acquisition voxel size (?0.6?mm) is inadequate. FEA plaque stress computations would be considerably more reliable if they would be used to identify thick-cap carotid plaques with low stresses instead. PMID:24317274

Nieuwstadt, Harm A; Speelman, Lambert; Breeuwer, Marcel; van der Lugt, Aad; van der Steen, Anton F W; Wentzel, Jolanda J; Gijsen, Frank J H

2014-02-01

237

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

238

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

239

Efficacy of essential oil mouthwash with and without alcohol: a 3-Day plaque accumulation model  

PubMed Central

Background The aim of this study was to evaluate the antiplaque effect of a new alcohol free essential oil mouthwash with respect to a control of an essential oil with alcohol mouthwash, using an in vivo plaque regrowth model of 3-days. Methods The study was designed as a double-masked, randomized, crossover clinical trial, involving 30 volunteers to compare two different essential oil containing mouthwashes, during a 3-day plaque accumulation model. After receiving a thorough professional prophylaxis at the baseline, over the next 3-days each volunteer refrained from all oral hygiene measures and had two daily rinses with 20 ml of the test mouthwash (alcohol free essential oil) or the control mouthwash (essential oil with alcohol). At the end of the each experimental period, plaque was assessed and the panelists filled out a questionnaire. Each subject underwent a 14 days washout period and there was a second allocation. Results The essential oil mouthwash with ethanol shows a better inhibitory effect of plaque regrowth in 3-days than the mouthwash test with only essential oil in the whole mouth (plaque index = 2.18 against 2.46, respectively, p < 0.05); for the lower jaw (plaque index = 2.28 against 2.57, respectively, p < 0.05); for the upper jaw (plaque index = 2.08 against 2.35, respectively, p < 0.05); for the incisors (plaque index = 1.93 against 2.27, respectively, p < 0.05); and the canines (plaque index = 1.99 against 2.47, respectively, p < 0.05). Conclusion The essential oil containing mouthwash without alcohol seems to have a less inhibiting effect on the plaque regrowth than the traditional alcoholic solution. Trial Registration ClinicalTrials.gov NCT01411618 PMID:22171999

2011-01-01

240

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

241

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

242

Bone morphogenetic protein -7 increases thrombogenicity of lipid-rich atherosclerotic plaques via activation of tissue factor  

Microsoft Academic Search

Thrombogenicity of atherosclerotic plaques largely depends on plaque morphology. Tissue factor (TF) expression is higher in lipid-rich than in calcified lesions. Although bone morphogenetic protein (BMP) -7 is a known inhibitor of vascular calcification, the role of BMP-7 in the development of plaque thrombogenicity is uncertain. We hypothesized that increased thrombogenic potential of lipid-rich plaques is attributed to activation of

M. A. Sovershaev; E. M. Egorina; V. Y. Bogdanov; N. Seredkina; J. T. Fallon; A. Y. Valkov; B. Østerud; J. B. Hansen

2010-01-01

243

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

244

Retiform purpura in plaques: a morphological approach to diagnosis.  

PubMed

Retiform purpura (RPP) is a livedoid pattern of cutaneous haemorrhage that may result from vasculitis, occlusion or altered coagulation. When this pattern presents as palpable plaques, vascular inflammation is present, and the differential diagnosis includes calciphylaxis, warfarin-induced skin necrosis, antiphospholipid antibody syndrome and heparin-induced skin necrosis. These diseases are clinically aggressive and may result in significant morbidity and mortality. Early recognition is essential to make the necessary medication changes and to begin intervention. Our morphological approach to diagnosis differs from traditional methods and can expedite management. Biopsy results and laboratory findings are then used to verify the diagnosis and determine the specific cause. This approach may allow the development of a treatment plan prior to availability of all ancillary data. Clinical and histological cases are presented for these four syndromes presenting as RPP. PMID:17489989

Jones, A; Walling, H

2007-09-01

245

Polyfluorinated bis-styrylbenzenes as amyloid-? plaque binding ligands.  

PubMed

Detection of cerebral ?-amyloid (A?) by targeted contrast agents remains of great interest to aid the in vivo diagnosis of Alzheimer's disease (AD). Bis-styrylbenzenes have been previously reported as potential A? imaging agents. To further explore their potency as (19)F MRI contrast agents we synthetized several novel fluorinated bis-styrylbenzenes and studied their fluorescent properties and amyloid-? binding characteristics. The compounds showed a high affinity for A? plaques on murine and human brain sections. Interestingly, competitive binding experiments demonstrated that they bound to a different binding site than chrysamine G. Despite their high logP values, many bis-styrylbenzenes were able to enter the brain and label murine amyloid in vivo. Unfortunately initial post-mortem (19)F NMR studies showed that these compounds as yet do not warrant further MRI studies due to the reduction of the (19)F signal in the environment of the brain. PMID:24657049

Nabuurs, Rob J A; Kapoerchan, Varsha V; Metaxas, Athanasios; de Jongh, Sanne; de Backer, Maaike; Welling, Mick M; Jiskoot, Wim; Windhorst, Albert D; Overkleeft, Hermen S; van Buchem, Mark A; Overhand, Mark; van der Weerd, Louise

2014-04-15

246

Diagnostic challenges of single plaque-like lesion paucibacillary leprosy  

PubMed Central

The diagnosis of single-lesion paucibacillary leprosy remains a challenge. Reviews by expert dermatopathologists and quantitative polymerase chain reaction (qPCR) results obtained from 66 single-plaque biopsy samples were compared. Histological findings were graded as high (HP), medium (MP) or low (LP) probability of leprosy or other dermatopathy (OD). Mycobacterium leprae-specific genes were detected using qPCR. The biopsies of 47 out of 57 clinically diagnosed patients who received multidrug therapy were classified as HP/MP, eight of which were qPCR negative. In the LP/OD (n = 19), two out of eight untreated patients showed positive qPCR results. In the absence of typical histopathological features, qPCR may be utilised to aid in final patient diagnosis, thus reducing overtreatment and delay in diagnosis. PMID:25411000

Barbieri, Raquel Rodrigues; Sales, Anna Maria; Illarramendi, Ximena; Moraes, Milton Ozório; Nery, José Augusto da Costa; Moreira, Suelen Justo Maria; Sarno, Euzenir Nunes; Machado, Alice de Miranda; Bozza, Fernando Augusto

2014-01-01

247

Plaque debulking for femoro-popliteal occlusions: techniques and results.  

PubMed

Although currently there is a trend of using percutaneous transluminal angioplasty (PTA) and stenting for the treatment of long occlusions of superficial femoral artery, many studies reported comparable results in terms of mid- and long-term patency between PTA and stenting and plaque debulking techniques such as remote endarterectomy, directional atherectomy catheter atherectomy and laser guided atherectomy. A successful debulking procedure is strongly associated with patients comorbidities, length of lesions and clinical presentation. In the last decade many new devices have been proposed to improve debulking results. Despite encouraging data about technical feasibility and limb salvage rate, debulking is still associated with a low rate of long-term primary and secondary patency. However, randomized clinical trials are expected and can hopefully provide conclusions on the effective durability of these procedures. PMID:23443599

Lenti, M; Marucchini, A; Isernia, G; Simonte, G; Ciucci, A; Cao, P; Verzini, F

2013-02-01

248

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

249

Non-invasive imaging of atherosclerotic plaque macrophage in a rabbit model with F-18 FDG PET: a histopathological correlation  

Microsoft Academic Search

BACKGROUND: Coronary atherosclerosis and its thrombotic complications are the major cause of mortality and morbidity throughout the industrialized world. Thrombosis on disrupted atherosclerotic plaques plays a key role in the onset of acute coronary syndromes. Macrophages density is one of the most critical compositions of plaque in both plaque vulnerability and thrombogenicity upon rupture. It has been shown that macrophages

Zhuangyu Zhang; Josef Machac; Gerard Helft; Stephen G Worthley; Cheuk Tang; Azfar G Zaman; Oswaldo J Rodriguez; Monte S Buchsbaum; Valentin Fuster; Juan J Badimon

2006-01-01

250

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

251

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

2009-01-01

252

Alzheimer's disease-related plaques in nondemented subjects.  

PubMed

Alzheimer's disease (AD) pathology was assessed in 587 nondemented subjects, with age at death at or more than 50 years. In 307 subjects, amyloid-? (A?) immunoreactive (IR) plaques were seen; in 192 subjects, neuritic plaques (NPs) stained with modified Bielschowsky silver stain (mBky) were observed. In 20% of the whole cohort and in 62% of the 192 subjects with NPs in mBky, hyperphosphorylated tau (HPtau) IR NPs were seen. In most cases in this nondemented cohort, the HPtau IR NPs were observed either sparsely or to a moderate extent. The correlation between the NP score and Braak stage was best (r=0.6, P<.001) when HPtau immunohistochemistry was used. Eighty-three percent of the subjects could not be categorized following the 1997 National Institute on Aging and the Reagan Institute (NIA-RI) recommendations, whereas the 2012 National Institute on Aging-Alzheimer's Association (NIA-AA) guidelines were applicable for all study subjects. Twenty-eight subjects had an intermediate level of AD neuropathological change according to the 2012 NIA-AA guidelines, and 25 of these 28 subjects displayed HPtau IR NPs in the temporal cortex. It is noteworthy, however, that as many as 119 out of the 192 subjects with NPs in mBky displayed HPtau IR NPs in the temporal cortex. Ninety-four of these 119 subjects with neocortical HPtau IR NPs had a low level of neuropathological AD change according to the 2012 NIA-AA guidelines because they were in Braak stages I and II. Thus, 94 subjects were not acknowledged as being at risk for AD when applying the 2012 NIA-AA guidelines. We suggest that to identify all subjects with cortical HPtau pathology and, consequently, probably being at risk for developing AD, in addition to the level of AD neuropathological change as recommended by the 2012 NIA-AA guidelines, assessment of HPtau IR NPs in the neocortex should be carried out. PMID:24742915

Elobeid, Adila; Rantakömi, Sanna; Soininen, Hilkka; Alafuzoff, Irina

2014-09-01

253

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

254

A calcium prerinse required to form calcium fluoride in plaque from a sodium fluoride rinse.  

PubMed

The purpose of this study is to determine whether a calcium (Ca) prerinse used before a 228 µg/g (ppm) fluoride (F) rinse would induce the formation of 'calcium fluoride-like' (CaF2-like) deposits in human dental plaque. Sixty minutes after the use of the Ca prerinse/F rinse, plaque samples were collected from 10 volunteers, homogenized, and split into 2 aliquots. The plaque mass from one aliquot was then extracted with a 'plaque-like' solution that extracted all the CaF2-like deposits. The total F in both aliquots was then determined and compared. The results demonstrated that, as in previous studies, the Ca prerinse induced large increases in plaque fluid and total plaque F. However, unlike previous results without the Ca prerinse, 30% of the plaque F deposits were CaF2 or CaF2-like. Given that maintaining an elevated F concentration in the vicinity of a developing lesion may play an important role in the cariostatic effect of this ion, and the potential advantages of CaF2-like deposits as an F source, these results suggest that a Ca prerinse may increase the cariostatic effect of topical agents. PMID:24401761

Vogel, G L; Tenuta, L M A; Schumacher, G E; Chow, L C

2014-01-01

255

IVUS-Based FSI Models for Human Coronary Plaque Progression Study: Components, Correlation and Predictive Analysis.  

PubMed

Atherosclerotic plaque progression is believed to be associated with mechanical stress conditions. Patient follow-up in vivo intravascular ultrasound coronary plaque data were acquired to construct fluid-structure interaction (FSI) models with cyclic bending to obtain flow wall shear stress (WSS), plaque wall stress (PWS) and strain (PWSn) data and investigate correlations between plaque progression measured by wall thickness increase (WTI), cap thickness increase (CTI), lipid depth increase (LDI) and risk factors including wall thickness (WT), WSS, PWS, and PWSn. Quarter average values (n = 178-1016) of morphological and mechanical factors from all slices were obtained for analysis. A predictive method was introduced to assess prediction accuracy of risk factors and identify the optimal predictor(s) for plaque progression. A combination of WT and PWS was identified as the best predictor for plaque progression measured by WTI. Plaque WT had best overall correlation with WTI (r = -0.7363, p < 1E-10), cap thickness (r = 0.4541, p < 1E-10), CTI (r = -0.4217, p < 1E-8), LD (r = 0.4160, p < 1E-10), and LDI (r = -0.4491, p < 1E-10), followed by PWS (with WTI: (r = -0.3208, p < 1E-10); cap thickness: (r = 0.4541, p < 1E-10); CTI: (r = -0.1719, p = 0.0190); LD: (r = -0.2206, p < 1E-10); LDI: r = 0.1775, p < 0.0001). WSS had mixed correlation results. PMID:25245219

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

2015-01-01

256

Estimation of Ultrasound Strain Indices in Carotid Plaque and Correlation to Cognitive Dysfunction  

PubMed Central

Carotid plaque prone to release emboli may be predicted by increased strain variations within plaque due to arterial pulsation over a cardiac cycle. Non-invasive ultrasound strain imaging may therefore be a viable surrogate to determine the risk of embolic stroke and possible cognitive impairment. Ultrasound strain imaging was performed on 24 human subjects with significant plaque, who also underwent standardized cognitive assessment (Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)) prior to a carotid endarterectomy (CEA) procedure. Radiofrequency signals were acquired using a Siemens Antares with a VFX 13-5 linear array transducer. Plaque regions were segmented by a radiologist at end-diastole using the Medical Imaging Interaction Toolkit. A hierarchical block-matching motion tracking algorithm was utilized to estimate the cumulated axial, lateral, and shear strains within the imaging plane. The maximum strain indices of the plaque, defined as mean accumulated strain over a small region of interest in the plaque with large deformations, were obtained. All the strain indices were then correlated with RBANS Total score. Overall cognitive performance was negatively associated with maximum axial and lateral strains respectively. The results demonstrate a direct relationship between the maximum axial and lateral strain indices in carotid plaque and cognitive impairment. PMID:25571271

Wang, X; Jackson, D.C.; Mitchell, C.C.; Varghese, T.; Hermann, B.P.; Kliewer, M.A.; Dempsey, R. J.

2014-01-01

257

Estimation of ultrasound strain indices in carotid plaque and correlation to cognitive dysfunction.  

PubMed

Carotid plaque prone to release emboli may be predicted by increased strain variations within plaque due to arterial pulsation over a cardiac cycle. Non-invasive ultrasound strain imaging may therefore be a viable surrogate to determine the risk of embolic stroke and possible cognitive impairment. Ultrasound strain imaging was performed on 24 human subjects with significant plaque, who also underwent standardized cognitive assessment (Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)) prior to a carotid endarterectomy (CEA) procedure. Radiofrequency signals were acquired using a Siemens Antares with a VFX 13-5 linear array transducer. Plaque regions were segmented by a radiologist at end-diastole using the Medical Imaging Interaction Toolkit. A hierarchical block-matching motion tracking algorithm was utilized to estimate the cumulated axial, lateral, and shear strains within the imaging plane. The maximum strain indices of the plaque, defined as mean accumulated strain over a small region of interest in the plaque with large deformations, were obtained. All the strain indices were then correlated with RBANS Total score. Overall cognitive performance was negatively associated with maximum axial and lateral strains respectively. The results demonstrate a direct relationship between the maximum axial and lateral strain indices in carotid plaque and cognitive impairment. PMID:25571271

Wang, X; Jackson, D C; Mitchell, C C; Varghese, T; Hermann, B P; Kliewer, M A; Dempsey, R J

2014-08-01

258

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

259

Effects of herbal and non-herbal toothpastes on plaque and gingivitis: A clinical comparative study  

PubMed Central

Background: Presence of plaque may be the culprit for dental caries, gingivitis, periodontal problems, and halitosis. Many mechanical aids are practiced worldwide to remove or control plaque, including tooth brushes, dental floss, mouth rinses, and dentifrices. The objective of this clinical study was to investigate the effectiveness of herbal toothpaste (Dabur Red) in controlling plaque and gingivitis, as compared to conventional (non-herbal) dentifrice (Pepsodent). Materials and Methods: In this study, 30 subjects aged 35–43 years with established gingivitis and at least 20 natural teeth, and having a probing depth <3 mm were investigated. After the washout period, plaque and gingival index (PI and GI, respectively) scores were assessed at days 0 and 30. Differences between groups were compared with Mann–Whitney U test and the mean scores of PI and GI by Wilcoxon test. Statistical difference between the weights of dentifrices tubes on days 0 and 30 was evaluated by Student's t-test. Results: At the end of 30 days of the study, there was statistically significant difference between both the groups for plaque and gingival scores. Conclusion: After 30 days of trial, both test and control groups showed effective reduction of plaque and gingivitis, which was statistically significant. No adverse reactions to dentifrices products were observed during the trial. It was concluded that herbal dentifrice was as effective as non-herbal dentifrices in the control of plaque and gingivitis. PMID:25558453

Tatikonda, Aravind; Debnath, Surangama; Chauhan, Vivek Singh; Chaurasia, Vishwajit Rampratap; Taranath, M; Sharma, Akanksha Manmohan

2014-01-01

260

Intravascular Ultrasound of Symptomatic Intracranial Stenosis Demonstrates Atherosclerotic Plaque with Intraplaque Hemorrhage: A Case Report  

PubMed Central

BACKGROUND Intracranial artery stenosis is assumed to represent atherosclerotic plaque. Catheter cerebral arteriography shows that intracranial stenosis may progress, regress, or remain unchanged. It is counterintuitive that atherosclerotic plaque should spontaneously regress, raising questions about the composition of intracranial stenoses. Little is known about this disease entity in vivo. We provide the first demonstration of in vivo atherosclerotic plaque with intraplaque hemorrhage using intravascular ultrasound (IVUS). CASE DESCRIPTION A 35-year-old man with multiple vascular risk factors presented with recurrent stroke failing medical therapy. Imaging demonstrated left internal carotid artery occlusion, severe intracranial right internal carotid artery stenosis, and cerebral perfusion failure. Cerebral arteriography with IVUS confirmed 85% stenosis of the petrous right carotid artery due to atherosclerotic plaque with intraplaque hemorrhage. Intracranial stent-supported angioplasty was performed with IRB approval. The patient recovered without complication. CONCLUSIONS This case supports the premise that symptomatic intracranial stenosis can be caused by atherosclerotic plaque complicated by intraplaque hemorrhage similar to coronary artery plaque. IVUS provides additional characteristics that define intracranial atherosclerosis and high-risk features. To our knowledge, this is the first report of stroke due to unstable atherosclerotic plaque with intraplaque hemorrhage in vivo. PMID:19021843

Meyers, Philip M.; Schumacher, H. Christian; Gray, William A.; Fifi, Johanna; Gaudet, John G.; Heyer, Eric J.; Chong, Ji Y.

2009-01-01

261

Improving visualization of intracranial arteries at the skull base for CT angiography with calcified plaques  

NASA Astrophysics Data System (ADS)

Bony structures at the skull base were the main obstacle to detection and estimation of arterial stenoses and aneurysms for CT angiography in the brain. Direct subtraction and the matched mask bone elimination (MMBE) have become two standard methods for removing bony structures. However, clinicians regularly find that calcified plaques at or near the carotid canal cannot be removed satisfactorily by existing methods. The blood-plaque boundary tends to be blurred by subtraction operation while plaque size is constantly overestimated by the bone mask dilation operation in the MMBE approach. In this study, we propose using the level of enhancement to adjust the MMBE bone mask more intelligently on the artery- and tissue-bone/plaque boundaries. The original MMBE method is only applied to the tissue-bone boundary voxels; while the artery-bone/blood-plaque boundary voxels, identified by a higher enhancement level, are processed by direct subtraction instead. A dataset of 6 patients (3 scanned with a regular dose and 3 scanned with a reduced dose) with calcified plaques at or near the skull base is used to examine our new method. Preliminary results indicate that the visualization of intracranial arteries with calcified plaques at the skull base can be improved effectively and efficiently.

Huang, Adam; Lee, Chung-Wei; Yang, Chung-Yi; Liu, Hon-Man

2010-03-01

262

Vasa vasorum in plaque angiogenesis, metabolic syndrome, type 2 diabetes mellitus, and atheroscleropathy: a malignant transformation  

PubMed Central

Background Vascularization is an exciting and complex mechanism involving angiogenesis and arteriogenesis. The metabolic syndrome (MS) and type 2 diabetes mellitus (T2DM) are associated with multiple metabolic toxicities, which result in reactive oxygen species (ROS) due to an elevated tension of oxidative-redox stress and an accelerated atherosclerosis termed atheroscleropathy. Results This atheroscleropathy is associated with accelerated angiogenesis within the vulnerable, thin-cap fibro-atheroma, prone to rupture resulting in acute coronary syndromes (ACS). The resulting intimopathy with its neovascularization due to angiogenesis of the adventitial vasa vasorum (Vv) is prone to intraplaque hemorrhage (IPH). These IPH are associated with destabilization of the vulnerable plaques resulting in plaque erosion and plaque rupture resulting in ACS. In atheroscleropathy the adventitial Vv invades the plaque in a malignant-like fashion and concurrently is associated with chronic inflammation, as macrophages are being deposited within the shoulder regions of these vulnerable plaques. These angiogenic Vv provide a custom delivery vascular network for multiple detrimental substrates, which further accelerates the growth of these vulnerable plaques and atheroscleropathy. There exists a vascularization paradox in MS and T2DM, in that, angiogenesis within the plaque is induced and arteriogenesis is impaired. Conclusion This review will attempt to provide a database of knowledge regarding the vascularization process (angiogenesis and arteriogenesis) and its mechanisms to better understand the increased cardiovascular risk and the increased morbidity and mortality associated with MS and T2DM. PMID:14761253

Hayden, Melvin R; Tyagi, Suresh C

2004-01-01

263

Evaluation of holy basil mouthwash as an adjunctive plaque control agent in a four day plaque regrowth model  

PubMed Central

Objectives: Various antibacterial and antiplaque agents are used in chemical plaque control but none are without their shortcomings. Chlorhexidine considered a gold standard, also has an array of side effects. To overcome these, numerous herbal extracts have been tried and tested and one among them is holy basil. The present study evaluated the antibacterial efficacy of holy basil in vitro against some periodontopathogens and its antiplaque effect in vivo. Study Design: Thirty periodontally healthy volunteers were randomly divided into three groups and refrained from all mechanical oral hygiene measures for 4 days and used one of the randomly assigned mouthwash (1- chlorhexidine; 2- holy basil; and 3- sterile water [placebo]) twice daily. The Plaque Index (PI) was assessed at days 0 and 5. Aqueous extract of holy basil was tested against Prevotella intermedia (P. intermedia) and Fusobacterium nucleatum (F.nucleatum). Results: Holy basil extract showed inhibition of both the tested periodontopathogens (P.intermedia and F.nucleatum) at various concentrations. In all groups, the PI increased from baseline to day 5. There was a statistically significant difference (p < .05) between the chlorhexidine and placebo rinse and the holy basil and placebo rinse, but no statistically significant difference was found between the chlorhexidine and holy basil rinse with respect to PI. Conclusions: These results indicate that the holy basil mouthwash has an antiplaque effect and is efficacious against P. intermedia and F. nucleatum strains in vitro. Hence holy basil mouthwash may have potential as an antiplaque mouthwash with prophylactic benefits. Key words:Antibacterial agent, basil, Fusobacterium nucleatum, mouthwashes, Prevotella intermedia.

Acharya, Anirudh B.; Vij, Chhavi; Trivedi, Dhiraj; Setty, Swati B.; Thakur, Srinath L.

2014-01-01

264

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

PubMed

Periodontal disease (PD) is a significant problem in dogs affecting between 44% and 63.6% of the population. The main etiological agent for PD is plaque, a microbial biofilm that colonizes teeth and causes inflammation of the gingiva. Understanding how this biofilm initiates on the tooth surface is of central importance in developing interventions against PD. Although the stages of plaque development on human teeth have been well characterized little is known about how canine plaque develops. Recent studies of the canine oral microbiome have revealed distinct differences between the canine and human oral environments and the bacterial communities they support, particularly with respect to healthy plaque. These differences mean knowledge about the nature of plaque formation in humans may not be directly translatable to dogs. The aim of this study was to identify the bacterial species important in the early stages of canine plaque formation in vivo and then use isolates of these species in a laboratory biofilm model to develop an understanding of the sequential processes which take place during the initial colonization of enamel. Supra-gingival plaque samples were collected from 12 dogs at 24 and 48 hour time points following a full mouth descale and polish. Pyrosequencing of the 16S rDNA identified 134 operational taxonomic units after statistical analysis. The species with the highest relative abundance were Bergeyella zoohelcum, Neisseria shayeganii and a Moraxella species. Streptococcal species, which tend to dominate early human plaque biofilms, had very low relative abundance. In vitro testing of biofilm formation identified five primary colonizer species, three of which belonged to the genus Neisseria. Using these pioneer bacteria as a starting point, viable two and three species communities were developed. Combining in vivo and in vitro data has led us to construct novel models of how the early canine plaque biofilm develops. PMID:25463050

Holcombe, Lucy J; Patel, Niran; Colyer, Alison; Deusch, Oliver; O'Flynn, Ciaran; Harris, Stephen

2014-01-01

265

Multiple lentigines in areas of resolving psoriatic plaques after ustekinumab therapy.  

PubMed

The development of lentigines in areas previously involved by psoriasis has been reported in the literature, classically related to phototherapy but also to topical products. More recently, some authors have described several cases of lentigines appearing in resolving psoriatic plaques during or after treatment with anti-tumour necrosis factor (TNF) drugs used to treat severe plaque psoriasis, including adalimumab, etanercept, and infliximab. We report the case of a patient that developed multiple lentigines after clearance of the plaques of psoriasis receiving treatment with ustekinumab for his psoriasis. PMID:24746301

Guttierez-Gonzalez, E; Batalla, A; de la Mano, D

2014-01-01

266

Pleural plaques and risk of cancer in Turin, northwestern Italy. An autopsy study  

SciTech Connect

The relationship between the occurrence of neoplastic diseases and the presence of pleural plaques was studied in a series of 1097 autopsies performed in Turin from the adult general population. In men, pleural plaques showed an association with the presence of laryngeal, pulmonary, esophageal, and colorectal cancer. Only cancer of the larynx was strongly related to the occurrence of such pleural changes. This autopsy investigation confirms previous observations by others based on x-ray findings, and suggests that pleural plaques may be regarded as risk indicators of possibly asbestos-related tumors in the general population.

Mollo, F.; Andrion, A.; Colombo, A.; Segnan, N.; Pira, E.

1984-10-01

267

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

268

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

PubMed Central

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.

2013-01-01

269

Imaging RAGE expression in atherosclerotic plaques in hyperlipidemic pigs  

PubMed Central

Background Receptor for advanced glycated end product (RAGE) expression is a prominent feature of atherosclerosis. We have previously shown in apoE null mice uptake of a radiolabeled anti-RAGE antibody in atherosclerotic plaque and now evaluate RAGE-directed imaging to identify advanced plaques in a large animal model. Methods Nine hyperlipidemic (HL) pigs were injected with 603.1?±?129.5 MBq of 99mTc-anti-RAGE F(ab?)2, and after 6 h (blood pool clearance), they underwent single-photon emission computed tomography/computed tomography (SPECT/CT) imaging of the neck, thorax, and hind limbs. Two HL pigs received 99mTc non-immune IgG F(ab?)2, and three farm pigs were injected with 99mTc-anti-RAGE F(ab?)2. After imaging, the pigs were euthanized. The aorta from the root to bifurcation was dissected, and the innominates, proximal carotids, and coronaries were dissected and counted, stained for H&E and RAGE, and AHA-classified. Results On pathology, 24% of the arterial segments showed AHA class III or IV lesions, and these lesions were confined almost exclusively to coronaries and carotids with % stenosis from 15% to 65%. Scatter plots of %ID/g for class III/IV vs. I/II lesions showed almost complete separation. Focal vascular uptake of tracer visualized on SPECT scans corresponded to class III/IV lesions in the coronary and carotid vessels. In addition, uptake in the hind limbs was noted in the HL pigs and corresponded to RAGE staining of small arteries in the muscle sections. Correlations for the vascular lesions were r?=?0.747, P?=?0.001 for %ID vs. %ID/g and r?=?0.83, P?=?0.002 for %ID/g vs. % RAGE staining. Conclusions Uptake of radiolabeled anti-RAGE antibody in coronary and carotid fibroatheroma and in the small arteries of the hind limbs in a relevant large animal model of atherosclerosis supports the important role of RAGE in atherosclerosis and peripheral artery disease as a target for imaging and treatment. PMID:25006545

2014-01-01

270

Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model  

SciTech Connect

Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.

Khan, Niloufer [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States)] [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Singh, Arun D., E-mail: singha@ccf.org [Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (United States)

2012-11-01

271

Folate receptor–targeted single-photon emission computed tomography/computed tomography to detect activated macrophages in atherosclerosis: can it distinguish vulnerable from stable atherosclerotic plaques?  

PubMed

The need for noninvasive imaging to distinguish stable from vulnerable atherosclerotic plaques is evident. Activated macrophages play a role in atherosclerosis and express folate receptor folate receptor ? (FR-?). The feasibility of folate targeting to detect atherosclerosis was demonstrated in human and mouse plaques, and it was suggested that molecular imaging of FR-? through folate conjugates might be a specific marker for plaque vulnerability. However, these studies did not allow differentiation between stable and vulnerable atherosclerotic plaques. We investigated the feasibility of a folate-based radiopharmaceutical (111)In-EC0800) with high-resolution animal single-photon emission computed tomography/computed tomography (SPECT/CT) to differentiate between stable and vulnerable atherosclerotic plaques in apolipoprotein E(?/?) mice in which we can induce plaques with the characteristics of stable and vulnerable plaques by placing a flow-modifying cast around the common carotid artery. Both plaques showed (111)In-EC0800 uptake, with higher uptake in the vulnerable plaque. However, the vulnerable plaque was larger than the stable plaque. Therefore, we determined tracer uptake per plaque volume and demonstrated higher accumulation of (111)In-EC0800 in the stable plaque normalized to plaque volume. Our data show that (111)In-EC0800 is not a clear-cut marker for the detection of vulnerable plaques but detects both stable and vulnerable atherosclerotic plaques in a mouse model of atherosclerosis. PMID:24757762

Winkel, Leah C J; Groen, Harald C; van Thiel, Bibi S; Müller, Cristina; van der Steen, Antonius F W; Wentzel, Jolanda J; de Jong, Marion; Van der Heiden, Kim

2014-01-01

272

Identification and characterization of a plaque forming avian rotavirus isolated from a wild bird in Japan.  

PubMed

From fresh faeces of a wild bird (Melanitta fusca), a virus that showed granular cytopathic effects (CPE) on chicken kidney cell (CKC) cultures was isolated. By indirect immunofluorescence analyses (IFA), this isolate reacted with an antiserum against a bovine rotavirus. The isolate produced clear plaques on CKC by conventional techniques, without trypsin. Three virus plaques were selected by plaque size (small, medium, and large) and cloned by three successive plaque cloning. In the SDS-PAGE analyses, dsRNA bands showed a typical profile of avian rotavirus and quite different from that of avian reovirus. With dsRNA patterns, IFA results, CPE, and a morphological property, the clones were identified as avian rotaviruses of group A rotavirus. The clones killed chicken embryos, when they were inoculated to yolk sac. PMID:1653040

Takehara, K; Kiuchi, H; Kuwahara, M; Yanagisawa, F; Mizukami, M; Matsuda, H; Yoshimura, M

1991-06-01

273

A fluorescence lifetime spectroscopy study of matrix metalloproteinases -2 and -9 in human atherosclerotic plaque  

PubMed Central

Matrix metalloproteinase (MMP) -2 and -9 play important roles in the progression of atherosclerosis. This study aims to determine whether MMP-2 and -9 content in the fibrotic caps of atherosclerotic plaque is correlated with plaque autofluorescence. A time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) system was used to measure the autofluorescence and assess the biochemical composition of human plaques obtained from carotid endarterectomy. Results presented here demonstrate for the first time the ability to characterize the biochemical composition as it relates to MMP-2 and -9 content in the atherosclerotic plaque cap using a label-free imaging technique implemented with a fiberoptic TR-LIFS system. PMID:21770037

Phipps, Jennifer E.; Hatami, Nisa; Galis, Zorina S.; Baker, J. Dennis; Fishbein, Michael C.; Marcu, Laura

2011-01-01

274

[Detection of vulnerable atherosclerotic plaque with near-infrared spectroscopy: a systematic review].  

PubMed

The term vulnerable atherosclerotic plaque is used to describe an atherosclerotic lesion with a high probability of rupture and thrombosis causing an acute coronary event or stroke. Pathogenesis of the vulnerable plaque has been well described pathologically and on experimental models. Detection of vulnerable plaques in vivo has been limited so far. There has been lack of methods able to predict future event from certain lesion characteristics that were rigorously validated on prospective clinical trials. Intravascular near-infrared spectroscopy is a novel technique that has been intentionally developed for the identification of a lipid core within a plaque. Results from recent clinical trials seem promising. This review briefly summarizes current knowledge in the field of near-infrared spectroscopy. PMID:24986001

St?chovský, Cyril; Horváth, Martin; Hájek, Petr; Veselka, Josef

2014-04-01

275

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.

276

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

277

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

278

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

PubMed Central

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.

2014-01-01

279

Material-specific imaging of atherosclerotic plaque using coherently scattered x rays  

NASA Astrophysics Data System (ADS)

The formation and development of plaques in the arterial wall is a direct consequence of atherosclerosis. The composition of a plaque is of particular interest as it is thought to be an important indicator of vulnerability, or risk of rupture and thrombosis. Current diagnostic methods do not yet have the ability to fully characterize plaque composition. Coherent-scatter imaging, a technique being developed in our laboratory, produces images based on the low-angle scattering properties of tissue. As these properties depend on molecular structure, material-specific maps of the different components in a tissue can be created. Material-specific images were produced for an atherosclerotic carotid artery. The image distributions of fatty and calcified deposits agreed with visual examination of the specimen. Preliminary results indicate that fat and calcifications, two typical plaque constituents, can be identified and distinguished from the undiseased vessel wall using coherently scattered x rays.

Davidson, Melanie T. M.; Batchelar, Deidre L.; Cunningham, Ian A.

2002-05-01

280

Coexistence of cervico-thoracic extradural en-plaque meningioma with multiple intracranial meningiomas.  

PubMed

Meningioma is one of the most common tumors in the spinal cord. Extradural and en-plaque variety of meningioma occur less frequently. A 47-year-old woman is presented with radiculopathy signs. Magnetic resonance imaging revealed a lesion from C6 through T3 vertebral levels compressing the cord both anteriorly and posteriorly. Subtotally excision was performed and histopathologic signs showed transitional type of meningioma (WHO Grade 1). Post operatively, she had good neurological recovery. Intraoperative findings point out that the en-plaque meningioma was pure extradural. Twelve cases of pure extradural en-plaque meningioma have been reported in the literature. Besides, to the best our knowledge coexistence of "en plaque" spinal epidural meningioma with meningiomas in cranial cavity has not been reported. Complete resection is mandatory to prevent recurrence. Moreover, it is considerably difficult to remove the parts of tumor over anterior of the dura without complication. PMID:25440016

Kale, Aydemir; Akyol, Cetin; Keskin, Emrah; Aydo?mu?, Evren; Ayd?n, Hasan Ali; Barut, Figen; Gül, Sanser; Kalayc?, Murat

2014-01-01

281

Clonal characteristics of fibrous plaques and fatty streaks from human aortas.  

PubMed Central

Using isoenzymes of glucose-6-phosphate dehydrogenase (G-6-PD) as cellular markers, a study was made of atherosclerotic fibrous plaques and fatty streaks in aortas of black women heterozygous for G-6-PD. Of 29 fibrous plaques, 26 (89.7%) contained only one isoenzyme (17, A; 9, B), the other three containing both A and B. Of 28 fatty streaks, five (17.8%) contained only one isoenzyme (2, A; 3, B), the remaining 23 containing both A and B. Normal uninvolved aorta contained both A and B isoenzymes in 99 of 101 samples. These results confirm the monoclonal character of atherosclerotic fibrous plaques; this strands in contrast to the fatty streaks which most commonly contain the two isoenzymes. The studies on the fatty streaks are inconclusive at this stage in determining whether the streak is the forerunner of the fibrous plaque. Images Figure 1 PMID:1190295

Pearson, T. A.; Wang, B. A.; Solez, K.; Heptinstall, R. H.

1975-01-01

282

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.

283

Changes in height of choroidal melanomas after plaque therapy.  

PubMed Central

Serial ultrasonic measurements of 82 uveal melanomas treated with brachytherapy plaques (cobalt-60 and iodine-125) and followed up for up to 141 months revealed that no two patients had identical patterns of change. The mean absolute change in tumour height after treatment was 1.8 mm at six months, 5.6 mm at 48 months for large tumours, and 0.9 and 1.9 mm for medium sized tumours. Eighty of the 82 patients fell into one of three patterns of response: 57 patients had a decrease in height after treatment (type D), 13 patients had the same height after treatment (type S), and 10 patients had a progressive increase in height (type I). Life table comparison showed no correlation between survival and location of tumour, sex of patient, size of tumour when treated, or laterality. There was a slight correlation between age and survival. Patients older than 60 died more frequently from metastatic melanoma than those under 60 (p = 0.06). Life table analysis showed a significant correlation between tumour regression type and survival. At 48 months the best cumulative probability of survival was in patients with type D (88% alive) compared with those of type I (34% alive, p = 0.0004). PMID:2378844

Abramson, D H; Servodidio, C A; McCormick, B; Fass, D; Zang, E

1990-01-01

284

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

285

IVUS-based histology of atherosclerotic plaques: improving longitudinal resolution  

NASA Astrophysics Data System (ADS)

Although Virtual Histology (VH) is the in-vivo gold standard for atherosclerosis plaque characterization in IVUS images, it suffers from a poor longitudinal resolution due to ECG-gating. In this paper, we propose an image-based approach to overcome this limitation. Since each tissue have different echogenic characteristics, they show in IVUS images different local frequency components. By using Redundant Wavelet Packet Transform (RWPT), IVUS images are decomposed in multiple sub-band images. To encode the textural statistics of each resulting image, run-length features are extracted from the neighborhood centered on each pixel. To provide the best discrimination power according to these features, relevant sub-bands are selected by using Local Discriminant Bases (LDB) algorithm in combination with Fisher's criterion. A structure of weighted multi-class SVM permits the classification of the extracted feature vectors into three tissue classes, namely fibro-fatty, necrotic core and dense calcified tissues. Results shows the superiority of our approach with an overall accuracy of 72% in comparison to methods based on Local Binary Pattern and Co-occurrence, which respectively give accuracy rates of 70% and 71%.

Taki, Arash; Pauly, Olivier; Setarehdan, S. Kamaledin; Unal, Gozde; Navab, Nassir

2010-03-01

286

Bilateral scaly plaques in axillae: pityriasis rosea of Vidal.  

PubMed

A 32-year-old man was referred for acute onset of pruritic scaly eruptions in the axillae of 8 days' duration, which was unresponsive to topical clotrimazole. The lesions consisted of multiple, coalescent oval plaques of 1 cm to 6 cm in longest diameter (Figure 1 and Figure 2) with central clearing and typical collarette scales at the periphery (Figure 3). Other skin areas and mucosal surfaces were unaffected. His general and systemic examinations were normal. Family and past histories were unremarkable except for a "ring worm-like patch" on his lower aspect of the abdomen 4 months ago, which rapidly regressed. On further inquiry, he gave a history of an episode of fever, coryza, and headache 3 weeks earlier to his eruption on the abdomen, which resolved with conservative remedies and one paracetamol tablet. He remained asymptomatic until axillary lesions appeared. We made a provisional diagnosis of pityriasis rosea (PR). Investigations including scrapings for potassium hydroxide examination, complete blood cell counts, urinalysis, blood sugar, VDRL test, and human immunodeficiency virus antibodies were all normal or non-reactive. As cutaneous biopsy revealed parakeratosis, epidermal spongiosis, dermal inflammatory cells, and extravasated red blood cells (Figure 4). The eruptions cleared within 8 days, following treatment with mometasone furoate cream and oral desloratidine 5 mg/d, leaving post-inflammatory hyperpigmentation. There was no recurrence for the next 6 months of observation. He was later lost to follow-up. PMID:23008948

Zawar, Vijay

2012-01-01

287

Optical coherence tomography and its use in detection of vulnerable plaque  

Microsoft Academic Search

Acute coronary syndromes and their associated complications related to coronary ischemia continue to be the leading cause\\u000a of morbidity and mortality in the world. The most commonly encountered pathophysiologic cascade of events resulting in this\\u000a picture is initiated by formation of a vulnerable plaque. Despite the widespread use of a variety of imaging technologies,\\u000a high-resolution detection of the vulnerable plaque

Mehmet Cilingiroglu; Kerem Ozer

2006-01-01

288

Presenilin-1 C410Y Alzheimer Disease Plaques Contain Synaptic Proteins  

Microsoft Academic Search

Presenilin-1 (PS-1) mutations are associated with familial Alzheimer's disease (AD). Although beta-amyloid (A?) plaques in brain tissue are characteristic of AD patients, space occupying “cotton-wool” plaques (CWPs) lacking dense A? cores have also been described in patients with mutations in exon 9 of the PS-1 gene. The composition of CWPs has not been fully described. To better elucidate the composition

Kamran Haleem; Carol F. Lippa; Thomas W. Smith; Hisatomo Kowa; Jianlin Wu; Takeshi Iwatsubo

2007-01-01

289

SOPROCARE - 450 nm wavelength detection tool for microbial plaque and gingival inflammation: a clinical study  

NASA Astrophysics Data System (ADS)

Gingivitis due to microbial plaque and calculus can lead over time if left untreated to advanced periodontal disease with non-physiological pocket formation. Removal of microbial plaque in the gingivitis stage typically achieves gingival health. The SOPROCARE camera system emits blue light at 450 nm wavelength using three blue diodes. The 450 nm wavelength is located in the non-ionizing, visible spectral wavelength region and thus is not dangerous. It is assumed that using the SOPROCARE camera in perio-mode inflamed gingiva can easily be observed and inflammation can be scored due to fluorescence from porphyrins in blood. The assumption is also that illumination of microbial plaque with blue light induces fluorescence due to the bacteria and porphyrin content of the plaque and thus can help to make microbial plaque and calculus visible. Aim of the study with 55 subjects was to evaluate the ability of the SOPROCARE fluorescence camera system to detect, visualize and allow scoring of microbial plaque in comparison to the Turesky modification of the Quigley and Hein plaque index. A second goal was to detect and score gingival inflammation and correlated the findings to the Silness and Löe gingival inflammation index. The study showed that scoring of microbial plaque as well as gingival inflammation levels similar to the established Turesky modified Quigley Hein index and the Silness and Löe gingival inflammation index can easily be done using the SOPROCARE fluorescence system in periomode. Linear regression fits between the different clinical indices and SOPROCARE scores in fluorescence perio-mode revealed the system's capacity for effective discrimination between scores.

Rechmann, P.; Liou, Shasan W.; Rechmann, Beate M.; Featherstone, John D.

2014-02-01

290

Acid formation in sucrose-exposed dental plaque in relation to caries incidence in schoolchildren  

Microsoft Academic Search

The aim was to investigate the composition and concentration of organic acids produced by plaque bacteria in vivo and its\\u000a possible relation to caries development in schoolchildren. Sucrose-exposed pooled plaque from 25 healthy teenagers was collected\\u000a and the levels of Streptococcus mutans and lactobacilli were estimated. The acid anions were analysed with isotachophoresis. The prevalence and incidence of dental\\u000a caries

M. K. Borgström; S. Edwardsson; G. Svensäter; S. Twetman

2000-01-01

291

Thrombospondin1 Deficiency Accelerates Atherosclerotic Plaque Maturation in ApoE\\/ Mice  

Microsoft Academic Search

Thrombospondin (TSP)1 is implicated in various inflammatory processes, but its role in atherosclerotic plaque formation and progression is unclear. Therefore, the development of atherosclerosis was compared in ApoE\\/ and Tsp1\\/ApoE\\/ mice kept on a normocholesterolemic diet. At 6 months, morphometric analysis of the aortic root of both mouse genotypes showed comparable lesion areas. Even when plaque burden increased 5-fold in

Rute Moura; Paul Holvoet; Marc F. Hoylaerts

2010-01-01

292

Magnetization transfer characteristics in atherosclerotic plaque components assessed by adapted binomial preparation pulses  

Microsoft Academic Search

Increasing the contrast between atheromatous plaque components is a major issue in cardiovascular MRI research. It would allow\\u000a one to identify unstable plaque by differentiating the lipid core associated with vulnerability, from the fibrous cap, considered\\u000a as a factor of stability. T2 and diffusion-weighted imaging have already provided satisfying results. Magnetization transfer (MT) between restricted protons\\u000a Hr and free-water protons

Mathilde Pachot-Clouard; Françoise Vaufrey; Luc Darrasse; Jean-François Toussainti

1998-01-01

293

Differential Accumulation of Proteoglycans and Hyaluronan in Culprit Lesions Insights Into Plaque Erosion  

Microsoft Academic Search

Objective—The importance of the extracellular matrix molecules versican, biglycan, decorin, and hyaluronan in plaque instability has not been recognized. Methods and Results—Coronary lesions with acute thrombi and stable plaques were examined for the accumulation and distribution of specific proteoglycans and hyaluronan at culprit sites. The cell surface receptor for hyaluronan, CD44, and smooth muscle (SM) cell maturation markers were also

Frank D. Kolodgie; Allen P. Burke; Andrew Farb; Deena K. Weber; Robert Kutys; Thomas N. Wight; Renu Virmani

294

Sirtuin 6 Expression and Inflammatory Activity in Diabetic Atherosclerotic Plaques: Effects of Incretin Treatment.  

PubMed

The role of sirtuin-6 (SIRT6) in atherosclerotic progression of diabetic patients is unknown. We evaluated SIRT6 expression and the effect of incretin-based therapies in carotid plaques of asymptomatic diabetic and non-diabetic patients. Plaques were obtained from 52 type 2 diabetic and 30 non-diabetic patients undergoing carotid endarterectomy. Twenty-two diabetic patients were treated with the drugs that work on the incretin system, glucagon-like-peptide-1 (GLP-1) receptor agonists and dipeptidyl-peptidase-4 (DPP-4)-inhibitors, for 26±8 months before endarterectomy. Compared to non-diabetic plaques, diabetic plaques had more inflammation and oxidative stress, along with a lesser SIRT6 expression and collagen content. Compared with no-GLP-1 therapies-treated plaques, GLP-1 therapies-treated plaques presented greater SIRT6 expression and collagen content, less inflammation and oxidative stress, indicating a more stable plaque phenotype. These results were supported by in vitro observations on endothelial progenitor cells (EPCs) and endothelial cells (EC). Indeed, both EPCs and EC treated with high-glucose (25mM) in the presence of GLP-1 (100 nM liraglutide) presented a greater SIRT6 and lower nuclear factor-kappa B (NF-?B) expression compared to cells treated only with high-glucose. These findings establish the involvement of SIRT6 in the inflammatory pathway(s) of diabetic atherosclerotic lesions and suggest its possible positive modulation by incretin, whose effect is associated with morphological and compositional characteristics of a potential stable plaque phenotype. PMID:25325735

Balestrieri, Maria Luisa; Rizzo, Maria Rosaria; Barbieri, Michelangela; Paolisso, Pasquale; D'Onofrio, Nunzia; Giovane, Alfonso; Siniscalchi, Mario; Minicucci, Fabio; Sardu, Celestino; D'Andrea, Davide; Mauro, Ciro; Ferraraccio, Franca; Servillo, Luigi; Chirico, Fabio; Caiazzo, Pasquale; Paolisso, Giuseppe; Marfella, Raffaele

2014-10-16

295

Vulnerable Plaque: From Bench to Bedside; Local Pacification Versus Systemic Therapy  

PubMed Central

Critical coronary stenoses accounts for a small proportion of acute coronary syndromes and sudden death. The majority are caused by coronary thromboses that arise from a nonangiographically obstructive atheroma. Recent developments in noninvasive imaging of so-called vulnerable plaques created opportunities to direct treatment to prevent morbidity and mortality associated with these high-risk lesions. This review covers therapy employed in the past, present, and potentially in the future as the natural history of plaque assessment unfolds. PMID:23439781

Kasim, Sazzli; Moran, Darragh; McFadden, Eugene

2012-01-01

296

Functionalization of gadolinium metallofullerenes for detecting atherosclerotic plaque lesions by cardiovascular magnetic resonance  

PubMed Central

Background The hallmark of atherosclerosis is the accumulation of plaque in vessel walls. This process is initiated when monocytic cells differentiate into macrophage foam cells under conditions with high levels of atherogenic lipoproteins. Vulnerable plaque can dislodge, enter the blood stream, and result in acute myocardial infarction and stroke. Imaging techniques such as cardiovascular magnetic resonance (CMR) provides one strategy to identify patients with plaque accumulation. Methods We synthesized an atherosclerotic-targeting contrast agent (ATCA) in which gadolinium (Gd)-containing endohedrals were functionalized and formulated into liposomes with CD36 ligands intercalated into the lipid bilayer. In vitro assays were used to assess the specificity of the ATCA for foam cells. The ability of ATCA to detect atherosclerotic plaque lesions in vivo was assessed using CMR. Results The ATCA was able to detect scavenger receptor (CD36)-expressing foam cells in vitro and were specifically internalized via the CD36 receptor as determined by focused ion beam/scanning electron microscopy (FIB-SEM) and Western blotting analysis of CD36 receptor-specific signaling pathways. The ATCA exhibited time-dependent accumulation in atherosclerotic plaque lesions of ApoE ?/? mice as determined using CMR. No ATCA accumulation was observed in vessels of wild type (C57/b6) controls. Non-targeted control compounds, without the plaque-targeting moieties, were not taken up by foam cells in vitro and did not bind plaque in vivo. Importantly, the ATCA injection was well tolerated, did not demonstrate toxicity in vitro or in vivo, and no accumulation was observed in the major organs. Conclusions The ATCA is specifically internalized by CD36 receptors on atherosclerotic plaque providing enhanced visualization of lesions under physiological conditions. These ATCA may provide new tools for physicians to non-invasively detect atherosclerotic disease. PMID:23324435

2013-01-01

297

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

298

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. PMID:25206220

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

2013-01-01

299

Type I collagen gene expression in human atherosclerosis. Localization to specific plaque regions.  

PubMed

Because collagen is a major component of the human atherosclerotic plaque, factors controlling collagen synthesis may have a profound influence on the volume growth of these intimal lesions. In human arteries, we compared normal vs atherosclerotic media vs intimas for type I collagen gene expression using immunocytochemistry and in situ messenger RNA hybridization with subsequent correlations with plaque topographical features. We also determined the associations of such collagen gene expression with proximity to monocyte/macrophages and T lymphocytes. Type I collagen synthesis appears to be upregulated in atherosclerotic plaques compared with their underlying medias and normal internal mammary arteries and coronary diffuse intimal thickenings. At least in established and advanced coronary and carotid plaques, type I collagen gene expression is focal and especially prevalent in fibrous cap and vascularized regions. Although macrophages and type I procollagen messenger RNA and protein are both found in atherosclerotic plaques, no apparent spatial correlation between macrophage presence and type I procollagen presence was found within these atherosclerotic intimas. Type I procollagen presence appears to be negatively associated with the spatial presence of T cells. Thus, human atherosclerotic plaques exhibit nonuniform patterns of type I collagen gene expression. Although the biochemical determinants of this focal gene expression have yet to be determined, it is conceivable that stimulatory/inhibitory cytokines and other factors (eg hemodynamics) play important roles in determining the focal nature of collagen synthesis in atherosclerosis. PMID:7504887

Rekhter, M D; Zhang, K; Narayanan, A S; Phan, S; Schork, M A; Gordon, D

1993-12-01

300

Development of an in vitro denture plaque biofilm to model denture malodour.  

PubMed

This study aimed to develop an in vitro denture plaque biofilm to model denture malodour. No previous studies have attempted to characterize the malodour associated with dentures and the effect of Candida spp. (main aetiological agent of denture-related stomatitis) on malodour. Pooled denture plaque microcosms and 'model' denture plaque biofilms (pooled saliva supplemented with additional microbial species) with and without addition of candida were grown aerobically at 37 °C for up to 13 days in a constant depth film fermenter (CDFF) on denture acrylic discs. Sample discs were removed, rinsed in sterile water and placed in phosphate buffered saline (PBS). The discs were vortex mixed to remove the biofilms, diluted in PBS and plated in duplicate onto general and selective media. The composition and stability of the biofilms over time were assessed. CDFF-grown microcosms and 'model' denture plaque biofilms were relatively stable in composition, with streptococci remaining the dominant microbial group. Model denture plaque biofilms were comparable in composition to denture plaque microcosms. This model system has the potential for evaluation of agents that might affect these parameters such as denture cleansers and other oral hygiene treatments. PMID:21386148

Coulthwaite, L; Verran, J

2008-03-01

301

Contribution of neovascularization and intraplaque haemorrhage to atherosclerotic plaque progression and instability.  

PubMed

Atherosclerosis is a continuous pathological process that starts early in life and progresses frequently to unstable plaques. Plaque rupture leads to deleterious consequences such as acute coronary syndrome, stroke and atherothrombosis. The vulnerable lesion has several structural and functional hallmarks that distinguish it from the stable plaque. The unstable plaque has large necrotic core (over 40% plaque volume) composed of cholesterol crystals, cholesterol esters, oxidized lipids, fibrin, erythrocytes and their remnants (haeme, iron, haemoglobin), and dying macrophages. The fibrous cap is thin, depleted of smooth muscle cells and collagen, and is infiltrated with proinflammatory cells. In unstable lesion, formation of neomicrovessels is increased. These neovessels have weak integrity and leak thereby leading to recurrent haemorrhages. Haemorrhages deliver erythrocytes to the necrotic core where they degrade promoting inflammation and oxidative stress. Inflammatory cells mostly presented by monocytes/macrophages, neutrophils and mast cells extravagate from bleeding neovessels and infiltrate adventitia where they support chronic inflammation. Plaque destabilization is an evolutionary process that could start at early atherosclerotic stages and whose progression is influenced by many factors including neovascularization, intraplaque haemorrhages, formation of cholesterol crystals, inflammation, oxidative stress and intraplaque protease activity. PMID:25515699

Chistiakov, D A; Orekhov, A N; Bobryshev, Y V

2015-03-01

302

Type I collagen gene expression in human atherosclerosis. Localization to specific plaque regions.  

PubMed Central

Because collagen is a major component of the human atherosclerotic plaque, factors controlling collagen synthesis may have a profound influence on the volume growth of these intimal lesions. In human arteries, we compared normal vs atherosclerotic media vs intimas for type I collagen gene expression using immunocytochemistry and in situ messenger RNA hybridization with subsequent correlations with plaque topographical features. We also determined the associations of such collagen gene expression with proximity to monocyte/macrophages and T lymphocytes. Type I collagen synthesis appears to be upregulated in atherosclerotic plaques compared with their underlying medias and normal internal mammary arteries and coronary diffuse intimal thickenings. At least in established and advanced coronary and carotid plaques, type I collagen gene expression is focal and especially prevalent in fibrous cap and vascularized regions. Although macrophages and type I procollagen messenger RNA and protein are both found in atherosclerotic plaques, no apparent spatial correlation between macrophage presence and type I procollagen presence was found within these atherosclerotic intimas. Type I procollagen presence appears to be negatively associated with the spatial presence of T cells. Thus, human atherosclerotic plaques exhibit nonuniform patterns of type I collagen gene expression. Although the biochemical determinants of this focal gene expression have yet to be determined, it is conceivable that stimulatory/inhibitory cytokines and other factors (eg hemodynamics) play important roles in determining the focal nature of collagen synthesis in atherosclerosis. Images Figure 1 Figure 3 PMID:7504887

Rekhter, M. D.; Zhang, K.; Narayanan, A. S.; Phan, S.; Schork, M. A.; Gordon, D.

1993-01-01

303

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

304

Detection of neuritic plaques in Alzheimer’s disease by magnetic resonance microscopy  

PubMed Central

Magnetic resonance microscopy (MRM) theoretically provides the spatial resolution and signal-to-noise ratio needed to resolve neuritic plaques, the neuropathological hallmark of Alzheimer’s disease (AD). Two previously unexplored MR contrast parameters, T2* and diffusion, are tested for plaque-specific contrast to noise. Autopsy specimens from nondemented controls (n = 3) and patients with AD (n = 5) were used. Three-dimensional T2* and diffusion MR images with voxel sizes ranging from 3 × 10?3 mm3 to 5.9 × 10?5 mm3 were acquired. After imaging, specimens were cut and stained with a microwave king silver stain to demonstrate neuritic plaques. From controls, the alveus, fimbria, pyramidal cell layer, hippocampal sulcus, and granule cell layer were detected by either T2* or diffusion contrast. These structures were used as landmarks when correlating MRMs with histological sections. At a voxel resolution of 5.9 × 10?5 mm3, neuritic plaques could be detected by T2*. The neuritic plaques emerged as black, spherical elements on T2* MRMs and could be distinguished from vessels only in cross-section when presented in three dimension. Here we provide MR images of neuritic plaques in vitro. The MRM results reported provide a new direction for applying this technology in vivo. Clearly, the ability to detect and follow the early progression of amyloid-positive brain lesions will greatly aid and simplify the many possibilities to intervene pharmacologically in AD. PMID:10570201

Benveniste, Helene; Einstein, Gillian; Kim, Katie R.; Hulette, Christine; Johnson, G. Allan

1999-01-01

305

Chronic imaging of amyloid plaques in the live mouse brain using multiphoton microscopy  

NASA Astrophysics Data System (ADS)

Transgenic mice expressing the human Amyloid Precursor Protein (APP) develop amyloid plaques as they age. These plaques resemble those found in the human disease. Multiphoton laser scanning microscopy combined with a novel surgical approach was used to measure amyloid plaque dynamics chronically in the cortex of living transgenic mice. Thioflavine S (thioS) was used as a fluorescent marker of amyloid deposits. Multiphoton excitation allowed visualization of amyloid plaques up to 200 micrometers deep into the brain. The surgical site could be imaged repeatedly without overt damage to the tissue, and individual plaques within this volume could be reliably identified over periods of several days to several months. On average, plaque sizes remained constant over time, supporting a model of rapid deposition, followed by relative stability. Alternative reporters for in vivo histology include thiazine red, and FITC-labeled amyloid-(Beta) peptide. We also present examples of multi-color imaging using Hoechst dyes and FITC-labeled tomato lectin. These approaches allow us to observe cell nuclei or microglia simultaneously with amyloid-(Beta) deposits in vivo. Chronic imaging of a variety of reporters in these transgenic mice should provide insight into the dynamics of amyloid-(Beta) activity in the brain.

Bacskai, Brian J.; Kajdasz, Stephen T.; Christie, R. H.; Zipfel, Warren R.; Williams, Rebecca M.; Kasischke, Karl A.; Webb, Watt W.; Hyman, B. T.

2001-04-01

306

A quantitative comet assay: imaging and analysis of virus plaques formed with a liquid overlay.  

PubMed

Although the plaque assay defines a "gold-standard" for measuring virus infectivity, its reliance on plaque counting limits its sensitivity. When the assay is performed with a liquid overlay, instead of agar overlay, spontaneous flows can promote a uni-directional spread of infection, creating elongated regions of cytopathology that resemble comets. As a model system comet and plaque cultures of vesicular stomatitis virus (VSV) on baby hamster kidney (BHK-21) cells were compared. Host-cell monolayers were infected with VSV particles, incubated 15 h in the presence of liquid or agar overlays and stained. VSV formed significantly larger comets than plaques, consistent with a mechanism of flow-enhanced spread. When antiviral drug (5-fluorouracil) was incorporated into the liquid overlay, comet sizes were reduced in a dose-dependent manner. Images of infected monolayers, acquired using a simple digital scanner, enabled a quantification of the inhibitory effect of the drug on infectivity. The resulting measure of drug susceptibility was found to be 18-fold more sensitive than the IC(50) measure attained by the traditional plaque-reduction assay. This quantitative comet assay has the potential to similarly enhance the sensitivity of infection measures for other plaque-forming viruses. PMID:17092573

Zhu, Ying; Yin, John

2007-01-01

307

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

308

Method for verifying the air kerma strength of I-125 plaques for the treatment of ocular melanoma.  

PubMed

The purpose of this work was to develop a method for easily verifying that the activity or air kerma strength of pre-assembled eye plaques, used in the treatment of ocular melanomas, agrees with the activity or air kerma strength called for in the treatment plan. A Capintec CRC-7 Dose Calibrator with its standard vial/syringe sample holder was used to measure the activity of pre-assembled COMS and Eye Physics EP917 eye plaques using IsoAid Advantage I-125 seeds. Plaque activity measurements were made by placing the plaque face up in the center of a 5 cm tall Styrofoam insert in the source holder. Activity measurements were made with the source holder rotated to four angles (0°, 90°, 180°, and 270°). The average of these four values was converted to air kerma strength and divided by the assay air kerma strength, from the NIST traceable source calibration, and decayed to the plaque measurement date, to determine a plaque calibration factor. The average of the calibration factors for each plaque type was used to establish a calibration factor for each plaque type. Several partially loaded plaque configurations were included in this study and different methods were used to determine the effects of partial loading. This verification method is easy to implement with commonly available equipment and is effective in identifying possible errors. During this two-year study, the air kerma strength of 115 eye plaques was checked and 11 possible errors were identified. PMID:25207419

Zimmermann, L W; Wilkinson, D Allan

2014-01-01

309

Real-time plaque characterization and visualization with spectral analysis of intravascular ultrasound data.  

PubMed

Coronary artery disease is the number one cause of death in the United States and the Western world, and approximately 250,000 affected people die per year without ever being admitted to a hospital. One of the main reasons of such a high death-rate without any diagnosis is that more than 50 or heart-attacks) occur in patients with no prior history of known heart disease or symptoms. Coronary artery disease leads to the occlusion of arteries that are vital in providing nutrients to the heart muscles. The disease develops by progressive accumulation or formation of "plaque" within an artery. Certain types of plaques could occlude blood flow and yet might be "stable". These plaques usually have a high fibrous content, and are known as hard plaques. On the other hand, "unstable" or "soft" plaques might not cause much occlusion but could be vulnerable to rupture. Rupture of such plaques could lead to total or partial occlusion in arteries resulting in sudden cardiac death or heart-attack. In fact, 68 coronary arteries are less than 50.Intravascular ultrasound (IVUS) is a minimally invasive imaging modality that provides cross-section images of arteries in real-time, allowing visualization of atherosclerotic plaques in vivo. In standard IVUS gray-scale images, calcified regions of plaque and dense fibrous components generally reflect ultrasound energy well and thus appear bright and homogeneous on IVUS images. Conversely, regions of low echo reflectance in IVUS images are usually labeled "soft" or "mixed" plaque. However, this visual interpretation has been demonstrated to be very inconsistent in accurately determining plaque composition and does not allow real-time assessment of quantitative plaque constituents.Spectral analysis of the backscattered radiofrequency (RF) ultrasound signals allows detailed assessment of plaque composition. Advanced mathematical techniques can be employed to extract spectral information from these RF data to determine composition. The spectral content or signature of RF data reflected from tissue depends on density, compressibility, concentration, size, etc. A combination of spectral parameters were used to develop statistical classification schemes for analysis of in vivo IVUS data in real-time. The clinical data acquisition system is ECG gated and the analysis software developed by our group reconstructs IVUS gray-scale images from the acquired RF data. A combination of spectral parameters and active contour models is used for real-time 3D plaque segmentation followed by computation of color-coded tissue maps for each image cross-section and longitudinal views of the entire vessel. The "fly-through" mode allows one to visualize the complete length of the artery internally with the histology components at the lumen surface. In addition, vessel and plaque metrics such as areas and volumes of individual plaque components (collagen, fibro-lipid, calcium, lipid-core) are also available. PMID:15923746

Nair, Anuja; Klingensmith, Jon D; Vince, D Geoffrey

2005-01-01

310

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

PubMed Central

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

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

2013-01-01

311

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

312

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

313

Correlation of cognitive function with ultrasound strain indices in carotid plaque.  

PubMed

Instability in carotid vulnerable plaque can generate cerebral micro-emboli, which may be related to both stroke and eventual cognitive abnormality. Strain imaging to detect plaque vulnerability based on regions with large strain fluctuations, with arterial pulsation, may be able to determine the risk of cognitive impairment. Plaque instability may be characterized by increased strain variations over a cardiac cycle. Radiofrequency signals for ultrasound strain imaging were acquired from the carotid arteries of 24 human patients using a Siemens Antares with a VFX 13-5 linear array transducer. These patients underwent standardized cognitive assessment (Repeatable Battery for the Assessment of Neuropsychological Status [RBANS]). Plaque regions were segmented by a radiologist at end-diastole using the Medical Imaging Interaction Toolkit. A hierarchical block-matching motion tracking algorithm was used to estimate the cumulated axial, lateral and shear strains within the imaging plane. The maximum, minimum and peak-to-peak strain indices in the plaque computed from the mean cumulated strain over a small region of interest in the plaque with large deformations were obtained. The maximum and peak-to-peak mean cumulated strain indices over the entire plaque region were also computed. All strain indices were then correlated with RBANS Total performance. Overall cognitive performance (RBANS Total) was negatively associated with values of the maximum strain and the peak-to-peak for axial and lateral strains, respectively. There was no significant correlation between the RBANS Total score and shear strain and strain indices averaged over the entire identified plaque for this group of patients. However, correlation of maximum lateral strain was higher for symptomatic patients (r = -0.650, p = 0.006) than for asymptomatic patients (r = -0.115, p = 0.803). On the other hand, correlation of maximum axial strain averaged over the entire plaque region was significantly higher for asymptomatic patients (r = -0.817, p = 0.016) than for symptomatic patients (r = -0.224, p = 0.402). The results reveal a direct relationship between the maximum axial and lateral strain indices in carotid plaque and cognitive impairment. PMID:24120415

Wang, Xiao; Jackson, Daren C; Varghese, Tomy; Mitchell, Carol C; Hermann, Bruce P; Kliewer, Mark A; Dempsey, Robert J

2014-01-01

314

Secreted proteins from carotid endarterectomy: an untargeted approach to disclose molecular clues of plaque progression  

PubMed Central

Background Atherosclerosis is the main cause of morbidity and mortality in Western countries and carotid plaque rupture is associated to acute events and responsible of 15-20% of all ischemic strokes. Several proteomics approaches have been up to now used to elucidate the molecular mechanisms involved in plaque formation as well as to identify markers of pathology severity for early diagnosis or target of therapy. The aim of this study was to characterize the plaque secretome. The advantage of this approach is that secretome mimics the in vivo condition and implies a reduced complexity compared to the whole tissue proteomics allowing the detection of under-represented potential biomarkers. Methods Secretomes from carotid endarterectomy specimens of 14 patients were analyzed by a liquid chromatography approach coupled with label free mass spectrometry. Differential expression of proteins released from plaques and from their downstream distal side segments were evaluated in each specimen. Results were validated by Western blot analysis and ELISA assays. Histology and immunohistochemistry were performed to characterize plaques and to localise the molecular factors highlighted by proteomics. Results A total of 463 proteins were identified and 31 proteins resulted differentially secreted from plaques and corresponding downstream segments. A clear-cut distinction in the distribution of cellular- and extracellular-derived proteins, evidently related to the higher cellularity of distal side segments, was observed along the longitudinal axis of carotid endarterectomy samples. The expressions of thrombospondin-1, vitamin D binding protein, and vinculin, as examples of extracellular and intracellular proteins, were immunohistologically compared between adjacent segments and validated by antibody assays. ELISA assays of plasma samples from 34 patients and 10 healthy volunteers confirmed a significantly higher concentration of thrombospondin-1 and vitamin D binding protein in atherosclerotic subjects. Conclusions Taking advantage of the optimized workflow, a detailed protein profile related to carotid plaque secretome has been produced which may assist and improve biomarker discovery of molecular factors in blood. Distinctive signatures of proteins secreted by adjacent segments of carotid plaques were evidenced and they may help discriminating markers of plaque complication from those of plaque growth. PMID:24131807

2013-01-01

315

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

316

Long-term Followup of Treatment of Peyronie's Disease with Plaque Incision, Carbon Dioxide Laser Plaque Ablation and Placement of a Deep Dorsal Vein Patch Graft  

Microsoft Academic Search

Numerous surgical therapies have been used for Peyronie's disease in patients who maintain potency. We report on incision and carbon dioxide laser ablation of Peyronie's plaque combined with a deep dorsal vein patch graft in the treatment of 6 men (mean age 57 years). The chief indication for surgery was curvature interfering with intromission, with voiding difficulty being a secondary

Edward D. Kim; Kevin T. McVary

1995-01-01

317

The Immune Response Is Involved in Atherosclerotic Plaque Calcification: Could the RANKL/RANK/OPG System Be a Marker of Plaque Instability?  

PubMed Central

Atherogenesis is characterized by an intense inflammatory process, involving immune and vascular cells. These cells play a crucial role in all phases of atherosclerotic plaque formation and complication through cytokine, protease, and prothrombotic factor secretion. The accumulation of inflammatory cells and thus high amounts of soluble mediators are responsible for the evolution of some plaques to instable phenotype which may lead to rupture. One condition strongly associated with plaque rupture is calcification, a physiopathological process orchestrated by several soluble factors, including the receptor activator of nuclear factor (NF)?B ligand (RANKL)/receptor activator of nuclear factor (NF)?B (RANK)/osteoprotegerin (OPG) system. Although some studies showed some interesting correlations with acute ischemic events, at present, more evidences are needed to evaluate the predictive and diagnostic value of serum sRANKL and OPG levels for clinical use. The major limitation is probably the poor specificity of these factors for cardiovascular disease. The identification of tissue-specific isoforms could increase the importance of sRANKL and OPG in predicting calcified plaque rupture and the dramatic ischemic consequences in the brain and the heart. PMID:18320012

Montecucco, Fabrizio; Steffens, Sabine; Mach, François

2007-01-01

318

Human dental plaque pH, and the organic acid and free amino acid profiles in plaque fluid, after sucrose rinsing.  

PubMed

The relationship between these factors was studied in plaque and plaque fluid samples taken at intervals during the Stephan pH curve following a sucrose mouth rinse. Levels of lactate rose after the rinse, then fell during the pH recovery phase. Levels of acetate, propionate and phosphate fell after rinsing, then rose again. Amino acid concentrations also changed, with many showing a fall followed by a rise; others rising then falling; and some showing a more variable or complex pattern. In resting plaque fluid, only alanine, proline, glutamic acid, glycine and ammonia were present at concentrations above 1 mmol/l. Delta-aminovaleric acid was detected at levels below those that have been found in monkeys. Hydroxyproline and hydroxylysine were consistently detected, levels of arginine were generally low, and those of cystine consistently very low. The results may provide a basis for understanding the complex metabolic interrelations that occur in the course of the Stephan curve and which may reflect or produce the observed pH changes. They suggest that besides the amount of acid produced, the type of acid, buffering power and base production should be considered as determinants of plaque pH. PMID:2597027

Higham, S M; Edgar, W M

1989-01-01

319

Plaque reduction neutralization test for human cytomegalovirus based upon enhanced uptake of neutral red by virus-infected cells.  

PubMed Central

Foci of cells infected with human cytomegalovirus were noted to stain more intensely than uninfected cells with neutral red, and this provided the basis for development of a plaque assay and plaque reduction neutralization test for cytomegalovirus. Plaques demonstrable by neutral red staining could be counted at 8 days after infection; thus, results could be obtained earlier than for plaque assay systems based upon the viral cytopathic effect, a fewer manipulations were required for staining cell monolayers to demonstrate plaques. Certain variables affecting plaque size and numbers and antibody titers were defined. Addition of fresh guinea pig complement to the reaction mixtures markedly enhanced cytomegalovirus-neutralizing antibody titers of hyperimmune animal sera, but titers of human sera were enhanced only two-or fourfold. Images PMID:182716

Schmidt, N J; Dennis, J; Lennette, E H

1976-01-01

320

Atherosclerotic plaque uptake of a novel integrin tracer 18F-Flotegatide in a mouse model of atherosclerosis  

PubMed Central

Rupture of unstable atherosclerotic plaque is the primary event leading to stroke and myocardial infarction. Plaque vulnerability may be induced by macrophage infiltration, neovessel formation and intraplaque instability. A tracer that selectively binds to macrophages and neovascular endothelium may identify rupture prone plaque. The 18F-labeled “R-G-D” containing tripeptide (Flotegatide) is a click chemistry derived radiotracer that binds to integrin ?v?3, a protein present in vulnerable plaque. We now demonstrate that Flotegatide preferentially binds to aortic plaque in an ApoE knock out mouse model of atherosclerosis. The tracer's uptake is strongly associated with presence of histologic markers for macrophage infiltration and integrin expression. There is a weaker but detectable association between Flotegatide uptake and presence of an immunohistochemical marker for neovascularization. We hypothesize that Flotegatide may be a useful tracer for visualization of inflamed plaque in clinical subjects. PMID:24627345

Su, Helen; Gorodny, Natalia; Gomez, Luis Felipe; Gangadharmath, Umesh B.; Mu, Fanrong; Chen, Gang; Walsh, Joseph C.; Szardenings, Katrin; Berman, Daniel S; Kolb, Hartmuth C.; Tamarappoo, Balaji K.

2015-01-01

321

Predictors of change in carotid atherosclerotic plaque inflammation and burden as measured by 18-FDG-PET and MRI, respectively, in the dal-PLAQUE study.  

PubMed

Baseline predictors of response to treatment of patients with coronary heart disease (CHD) with respect to vascular inflammation and atherosclerotic plaque burden are poorly understood. From post hoc analysis of the dal-PLAQUE study (NCT00655473), 18F-fluorodeoxyglucose-positron emission tomography (18-FDG-PET) imaging and carotid black blood magnetic resonance imaging (MRI) were used to track changes in these vascular parameters. Baseline demographics, imaging, and biomarkers were collected/measured in 130 patients with CHD or CHD risk-equivalents, and imaging follow-up at 6 months (PET) and 24 months (MRI) was performed. Using stepwise linear regression, predictors of change in carotid plaque inflammation by PET [target-to-background ratio (TBR), n = 92] and plaque burden by MRI [wall area (WA) and total vessel area (TVA), n = 89] were determined. Variables with p < 0.05 in multivariable models were considered independently significant. Interleukin-6, systolic blood pressure and standard deviation of wall thickness (WT) at baseline were independently positively associated with 18-FDG uptake (mean of maximum [MeanMax] TBR change over 6 months). Mean of mean TBR, phospholipase A2, apolipoprotein A-I, and high-sensitivity C-reactive protein at baseline were independently negatively associated with MeanMax TBR change over 6 months. Mean WT and plasminogen activator inhibitor-1 (PAI-1) activity at baseline, and age, were independently associated with change in WA over 24 months. For TVA changes; mean WA and PAI-1 activity at baseline, age, and female gender were independent predictors. These findings may help determine patients most suitable for clinical trials employing plaque inflammation or burden changes as endpoints. PMID:24458953

Mani, Venkatesh; Woodward, Mark; Samber, Daniel; Bucerius, Jan; Tawakol, Ahmed; Kallend, David; Rudd, James H F; Abt, Markus; Fayad, Zahi A

2014-03-01

322

Coaggregation-Mediated Interactions of Streptococci and Actinomyces Detected in Initial Human Dental Plaque  

PubMed Central

Streptococci and actinomyces that initiate colonization of the tooth surface frequently coaggregate with each other as well as with other oral bacteria. These observations have led to the hypothesis that interbacterial adhesion influences spatiotemporal development of plaque. To assess the role of such interactions in oral biofilm formation in vivo, antibodies directed against bacterial surface components that mediate coaggregation interactions were used as direct immunofluorescent probes in conjunction with laser confocal microscopy to determine the distribution and spatial arrangement of bacteria within intact human plaque formed on retrievable enamel chips. In intrageneric coaggregation, streptococci such as Streptococcus gordonii DL1 recognize receptor polysaccharides (RPS) borne on other streptococci such as Streptococcus oralis 34. To define potentially interactive subsets of streptococci in the developing plaque, an antibody against RPS (anti-RPS) was used together with an antibody against S. gordonii DL1 (anti-DL1). These antibodies reacted primarily with single cells in 4-h-old plaque and with mixed-species microcolonies in 8-h-old plaque. Anti-RPS-reactive bacteria frequently formed microcolonies with anti-DL1-reactive bacteria and with other bacteria distinguished by general nucleic acid stains. In intergeneric coaggregation between streptococci and actinomyces, type 2 fimbriae of actinomyces recognize RPS on the streptococci. Cells reactive with antibody against type 2 fimbriae of Actinomyces naeslundii T14V (anti-type-2) were much less frequent than either subset of streptococci. However, bacteria reactive with anti-type-2 were seen in intimate association with anti-RPS-reactive cells. These results are the first direct demonstration of coaggregation-mediated interactions during initial plaque accumulation in vivo. Further, these results demonstrate the spatiotemporal development and prevalence of mixed-species communities in early dental plaque. PMID:12754239

Palmer, Jr., Robert J.; Gordon, Sharon M.; Cisar, John O.; Kolenbrander, Paul E.

2003-01-01

323

Noncalcified Coronary Atherosclerotic Plaque and Immune Activation in HIV-Infected Women  

PubMed Central

Background.?Little is known about coronary plaque in human immunodeficiency virus (HIV)–infected women. Methods.?Sixty HIV-infected and 30 non–HIV-infected women without symptoms or history of cardiovascular disease were recruited to assess coronary plaque with coronary computed tomographic angiography and immune activation. Data from 102 HIV-infected men and 41 non–HIV-infected male controls were compared. Results.?HIV-infected women demonstrated significantly higher percentages of segments with noncalcified plaque (mean ± SD, 74% ± 28% vs 23% ± 39% compared to female control subjects; median [interquartile range], 75% [63%–100%] vs 0% [0%–56%]; P = .007) and more segments with noncalcified plaque (mean ± SD, 0.92 ± 1.48 vs 0.40 ± 1.44; median [interquartile range], 0 [0–2] vs 0 [0–0]; P = .04). Immune activation parameters, including soluble CD163 (sCD163; P = .006), CXCL10 (P = .002), and percentages of CD14+CD16+ monocytes (P = .008), were higher in HIV-infected women than in female control subjects, but no differences were seen in general inflammatory markers. Among HIV-infected women with noncalcified coronary plaque, sCD163 levels were significantly higher than in HIV-infected women without noncalcified plaque (P = .04). In multivariate modeling for sCD163 levels among male and female subjects, significant effects of HIV (P < .0001), age (P = .002), and sex (P = .0002) were seen. Conclusions.?Young, asymptomatic, HIV-infected women, demonstrate increased noncalcified coronary plaque and increased immune activation, particularly monocyte activation. Independent effects of sex, HIV status, and aging on immune activation may contribute to cardiovascular disease in this population. Clinical Trials Registration.?NCT00455793. PMID:24041790

Fitch, Kathleen V.; Srinivasa, Suman; Abbara, Suhny; Burdo, Tricia H.; Williams, Kenneth C.; Eneh, Peace; Lo, Janet; Grinspoon, Steven K.

2013-01-01

324

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

325

Data mining of atherosclerotic plaque transcriptomes predicts STAT1-dependent inflammatory signal integration in vascular disease.  

PubMed

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

326

Statins use and coronary artery plaque composition: Results from the International Multicenter CONFIRM Registry  

PubMed Central

Objective The effect of statins on coronary artery plaque features beyond stenosis severity is not known. Coronary CT angiography (CCTA) is a novel non-invasive method that permits direct visualization of coronary atherosclerotic features, including plaque composition. We evaluated the association of statin use to coronary plaque composition type in patients without known coronary artery disease (CAD) undergoing CCTA. Methods From consecutive individuals, we identified 6673 individuals (2413 on statin therapy and 4260 not on statin therapy) with no known CAD and available statin use status. We studied the relationship between statin use and the presence and extent of specific plaque composition types, which was graded as non-calcified (NCP), mixed (MP), or calcified (CP) plaque. Results The mean age was 59 ± 11 (55% male). Compared to the individuals not taking statins, those taking statins had higher prevalence of risk factors and obstructive CAD. In multivariable analyses, statin use was associated with increased the presence of MP [odds ratio (OR) 1.46, 95% confidence interval (CI) 1.27–1.68), p < 0.001] and CP (OR 1.54, 95% CI 1.36–1.74, p < 0.001), but not NCP (OR 1.11, 95% CI 0.96–1.29, p = 0.1). Further, in multivariable analyses, statin use was associated with increasing numbers of coronary segments possessing MP (OR 1.52, 95% CI 1.34–1.73, p < 0.001) and CP (OR 1.52, 95% CI 1.36–1.70, p < 0.001), but not coronary segments with NCP (OR 1.09, 95% CI 0.94–1.25, p = 0.2). Conclusion Statin use is associated with an increased prevalence and extent of coronary plaques possessing calcium. The longitudinal effect of statins on coronary plaque composition warrants further investigation. PMID:22981406

Nakazato, Ryo; Gransar, Heidi; Berman, Daniel S.; Cheng, Victor Y.; Lin, Fay Y.; Achenbach, Stephan; Al-Mallah, Mouaz; Budoff, Matthew J.; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Cury, Ricardo C.; Chinnaiyan, Kavitha; Chow, Benjamin J.W.; Delago, Augustin; Hadamitzky, Martin; Hausleiter, Joerg; Kaufmann, Philipp; Maffei, Erica; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Dunning, Allison; Feuchtner, Gudrun; Kim, Yong-Jin; Leipsic, Jonathon; Min, James K.

2014-01-01

327

Ultrastructure and morphology of biofilms on thermoplastic orthodontic appliances in 'fast' and 'slow' plaque formers.  

PubMed

The aim of this study was to investigate the morphological features and distribution of biofilms on Invisalign orthodontic appliances, in a sample of 'slow' and 'fast' plaque formers using scanning electron microscopy (SEM). Fifty-six Chinese male/female volunteers (aged 19-39 years) were screened for their plaque-forming rate using the plaque percentage index (PPI) coupled with digital photography and computer-based image analysis, after a period of 48 hours of abstinence from oral hygiene procedures. Eleven volunteers (seven males/four females) representing the lowest and highest ends of the plaque formation spectrum were chosen as slow and fast plaque formers, respectively. The subjects wore a full-coverage splint appliance, in which four tiles of Invisalign material were embedded. These tiles were collected at intervals of 1, 3, 6, 12, 24, and 48 hours, as well as 3, 7, and 14 days, immediately fixed in 10 per cent paraformaldehyde in 0.2 M cacodylate buffer solution and prepared for SEM. The surface configuration of the Invisalign appliance was visualized, as well as the chronological pattern of biofilm formation. Significance between fast and slow plaque formers was determined using a Student's t-test. Colonization appeared to centre initially on the raised edges or textured surfaces of the appliance, and initial adhesion was quicker and more abundant in the fast plaque-forming group. In the later stages of biofilm development, both groups showed no discernible differences in biofilm accrual on the surfaces, but the fast group displayed a more complex biofilm structure. More recessed and sheltered areas of the appliance, such as the cusp tips and attachment dimples, harboured more biofilm than the flat surfaces. Hence, it seems that the novel Invisialign orthodontic appliance is a useful tool to investigate the features of biofilm formation in time-course studies. PMID:21187528

Low, Bernard; Lee, Wilson; Seneviratne, C J; Samaranayake, Lakshman P; Hägg, Urban

2011-10-01

328

Variations in the predominant cultivable microflora of dental plaque at defined subsites on approximal tooth surfaces in children  

Microsoft Academic Search

The distribution and composition of the resident microflora were determined in approximal gingival margin plaque from 21 premolars extracted from schoolchildren (mean age 12.0 ± 1.8 yr). Indigo carmine (5% w\\/v) was used to visualize plaque to facilitate sampling. About 1 mm2 of plaque was removed from sites away from (A), to the side of (S), and below (B) the

K. G. Babaahmady; P. D. Marsh; S. J. Challacombe; H. N. Newman

1997-01-01

329

The Protein and Lipid Composition of Arterial Elastin and Its Relationship to Lipid Accumulation in the Atherosclerotic Plaque  

PubMed Central

Elastin preparations from intimal layers and the media of normal and atherosclerotic human aortae were analyzed for protein and lipid content. In atherosclerotic aortae, elastin from plaques was compared with elastin from adjacent normal appearing areas of the same aorta. Arterial elastin purified by alkaline extraction appeared to be a protein-lipid complex containing free and ester cholesterol, phospholipids, and triglycerides. The lipid component of normal arterial elastin was small (1-2%). With increasing severity of atherosclerosis, there was a progressive accumulation of lipid in intimal elastin from plaques, reaching a mean lipid content of 37% in severe plaques. The increase in the lipid content of plaque elastic preparations was mainly due to large increases in cholesterol, over 80% of which was cholesteryl ester. This deposition of cholesterol in plaque elastin accounted for 20-34% of the total cholesterol content of the plaque. The increased lipid deposition in plaque elastin was associated with alterations in the amino acid composition of plaque elastin. In elastin from plaque intima, the following polar amino acids were increased significantly: aspartic acid, threonine, serine, glutamic acid, lysine, histidine, and arginine; whereas, cross-linking amino acids: desmosine, isodesmosine, and lysinonorleucine were decreased significantly. The amino acid and lipid composition of elastin from normal appearing aortic areas was comparable to that of normal arterial elastin except for intimal elastin directly adjacent to and medial elastin directly below the most severe plaques. The data indicate that the focal lipid deposition in early atherosclerotic plaques is due to a large extent to lipid accumulations in altered elastin protein of localized intimal areas. Continued lipid deposition in altered elastin appears to contribute substantially to the progressive lipid accumulation in the plaque. The study suggests that elastin of intimal elastic membranes may play an important role in the pathogenesis and progression of atherosclerosis. PMID:5097573

Kramsch, Dieter M.; Franzblau, Carl; Hollander, William

1971-01-01

330

A mechanistic analysis of the role of microcalcifications in atherosclerotic plaque stability: potential implications for plaque rupture  

PubMed Central

The role of microcalcifications (?Calcs) in the biomechanics of vulnerable plaque rupture is examined. Our laboratory previously proposed (Ref. 44), using a very limited tissue sample, that ?Calcs embedded in the fibrous cap proper could significantly increase cap instability. This study has been greatly expanded. Ninety-two human coronary arteries containing 62 fibroatheroma were examined using high-resolution microcomputed tomography at 6.7-?m resolution and undecalcified histology with special emphasis on calcified particles <50 ?m in diameter. Our results reveal the presence of thousands of ?Calcs, the vast majority in lipid pools where they are not dangerous. However, 81 ?Calcs were also observed in the fibrous caps of nine of the fibroatheroma. All 81 of these ?Calcs were analyzed using three-dimensional finite-element analysis, and the results were used to develop important new clinical criteria for cap stability. These criteria include variation of the Young's modulus of the ?Calc and surrounding tissue, ?Calc size, and clustering. We found that local tissue stress could be increased fivefold when ?Calcs were closely spaced, and the peak circumferential stress in the thinnest nonruptured cap (66 ?m) if no ?Calcs were present was only 107 kPa, far less than the proposed minimum rupture threshold of 300 kPa. These results and histology suggest that there are numerous ?Calcs < 15 ?m in the caps, not visible at 6.7-?m resolution, and that our failure to find any nonruptured caps between 30 and 66 ?m is a strong indication that many of these caps contained ?Calcs. PMID:22777419

Maldonado, Natalia; Kelly-Arnold, Adreanne; Vengrenyuk, Yuliya; Laudier, Damien; Fallon, John T.; Virmani, Renu; Cardoso, Luis

2012-01-01

331

Technetium complexes for diagnostic imaging of amyloid-beta plaques to assist in the diagnosis of Alzheimer's disease .  

E-print Network

??The pathological hallmarks of Alzheimer???s disease (AD) include extracellular plaques, primarily composed of aggregated A?? peptide, and intracellular neurofibrillary tangles (NFTs) of hyperphosphorylated tau protein.… (more)

Hayne, David John

2014-01-01

332

Impact of enucleation versus plaque radiotherapy in the management of juxtapapillary choroidal melanoma on patient survival.  

PubMed Central

The records of 265 consecutive patients with juxtapapillary choroidal melanoma were reviewed and a statistical non-randomised retrospective study was performed to evaluate the risk for metastasis and compare the survival rate of patients treated with plaque radiotherapy or enucleation. To obtain sufficient overlap between the enucleation and plaque radiotherapy, the statistical analysis was limited to an adjusted subgroup of 127 patients who met eligibility criteria for plaque radiotherapy and who had a minimum of 3 years of follow up after treatment. In the adjusted subgroup of 127 patients, 92 patients (72%) were initially treated with enucleation and 35 (28%) with plaque radiotherapy. In both univariate and multivariate logistic analysis models, the age of the patient (> 50 years), tumour thickness (> 3 mm), and treatment by age interaction were found to be significant factors for development of distant metastasis. In patients younger than 50 years, the method of treatment (enucleation versus plaque radiotherapy) did not significantly affect the risk of metastasis. For those older than 50 years, there was a non-significant trend for patients in the enucleation group to be at a higher risk for metastasis than those in the plaque group. In the enucleation group, patients older than 50 years had a significantly higher incidence of distant metastasis than those younger than 50 years. In the plaque radiotherapy group, there was no significant higher incidence of metastasis in patients younger than 50 years than in those older than 50 years. When a Cox proportional hazards model was used to evaluate the survival rate, there was the same statistically significant effect of treatment by age interaction as was found in the multivariate logistic model on survival time. Moreover, there was a significant effect of treatment by tumour thickness interaction on survival time. Patients in the enucleation group had a better survival rate when the thickness of the tumour was less than 3 mm compared with a tumour of more than 3 mm. There were no apparent effects of tumour thickness on survival for patients treated with plaque radiotherapy. From these results, the authors currently recommend plaque radiotherapy as a viable option to enucleation in patients with juxtapapillary choroidal melanoma. PMID:8123617

De Potter, P; Shields, C L; Shields, J A; Cater, J R; Tardio, D J

1994-01-01

333

Environmental pleural plaques in residents of a Quebec chrysotile mining town.  

PubMed

We report four cases of pleural plaques found at autopsy in individuals who resided in or near the chrysotile mining town of Thetford Mines, Quebec, and who had never been employed in the chrysotile mining and milling industry. Three of these patients were farmers, and one was a road construction worker. Lung asbestos content of these cases was compared with that of a group of nine persons living in the same vicinity who did not have pleural plaques. The plaque group was found to have an equal chrysotile content but about a fourfold elevation in median tremolite content, a statistically significant increase. Fiber sizes were the same in both groups. Also, one plaque case had an elevated level of relatively long titanium oxide fibers. These observations suggest that environmental pleural plaques in this region of Quebec are probably caused by exposure to tremolite derived from local soil and rock and that other types of mineral fibers such as titanium oxide may occasionally also be the cause of such lesions. PMID:2838224

Churg, A; DePaoli, L

1988-07-01

334

Nanorose and lipid detection in atherosclerotic plaque using dual-wavelength photothermal wave imaging  

NASA Astrophysics Data System (ADS)

Atherosclerosis and specifically rupture of vulnerable plaques account for 23% of all deaths worldwide, far surpassing both infectious diseases and cancer. In atherosclerosis, macrophages can infiltrate plaques which are often associated with lipid deposits. Photothermal wave imaging is based on the periodic thermal modulation of a sample using intensity modulated light. Intensity modulated light enters the sample and is absorbed by targeted chromophores and generates a periodic thermal modulation. We report use of photothermal wave imaging to visualize nanoroses (taken up by macrophages via endocytosis) and lipids in atherosclerotic plaques. Two excitation wavelengths were selected to image nanoroses (800 nm) and lipids (1210 nm). Atherosclerotic plaque in a rabbit abdominal artery was irradiated (800 nm and 1210 nm separately) at a frequency of 4 Hz to generate photothermal waves. The radiometric temperature at the tissue surface was recorded by an infrared (IR) camera over a 10 second time period at the frame rate of 25.6 Hz. Extraction of images (256 × 256 pixels) at various frequencies was performed by Fourier transform at each pixel. Frequency amplitude images were obtained corresponding to 800 nm and 1210 nm laser irradiation. Computed images suggest that the distributions of both nanorose and lipid can be identified in amplitude images at a frequency of 4 Hz. Nanoroses taken up by macrophages are distributed at the edges of lipid deposits. Observation of high concentration of nanoroses in atherosclerotic plaque confirms that nanoroses are present at locations associated with lipid deposits.

Wang, Tianyi; Qiu, Jinze; Ma, Li Leo; Li, Xiankai; Sun, Jingjing; Ryoo, Seungyup; Johnston, Keith P.; Feldman, Marc D.; Milner, Thomas E.

2010-02-01

335

Clinical validation of robot simulation of toothbrushing - comparative plaque removal efficacy  

PubMed Central

Background Clinical validation of laboratory toothbrushing tests has important advantages. It was, therefore, the aim to demonstrate correlation of tooth cleaning efficiency of a new robot brushing simulation technique with clinical plaque removal. Methods Clinical programme: 27 subjects received dental cleaning prior to 3-day-plaque-regrowth-interval. Plaque was stained, photographically documented and scored using planimetrical index. Subjects brushed teeth 33–47 with three techniques (horizontal, rotating, vertical), each for 20s buccally and for 20s orally in 3 consecutive intervals. The force was calibrated, the brushing technique was video supported. Two different brushes were randomly assigned to the subject. Robot programme: Clinical brushing programmes were transfered to a 6-axis-robot. Artificial teeth 33–47 were covered with plaque-simulating substrate. All brushing techniques were repeated 7 times, results were scored according to clinical planimetry. All data underwent statistical analysis by t-test, U-test and multivariate analysis. Results The individual clinical cleaning patterns are well reproduced by the robot programmes. Differences in plaque removal are statistically significant for the two brushes, reproduced in clinical and robot data. Multivariate analysis confirms the higher cleaning efficiency for anterior teeth and for the buccal sites. Conclusions The robot tooth brushing simulation programme showed good correlation with clinically standardized tooth brushing. This new robot brushing simulation programme can be used for rapid, reproducible laboratory testing of tooth cleaning. PMID:24996973

2014-01-01

336

The effect of iterative reconstruction on quantitative computed tomography assessment of coronary plaque composition.  

PubMed

To compare coronary plaque size and composition as well as degree of coronary artery stenosis on coronary Computed Tomography angiography (CCTA) using three levels of iterative reconstruction (IR) with standard filtered back projection (FBP). In 63 consecutive patients with a clinical indication for CCTA 55 coronary plaques were analysed. Raw data were reconstructed using standard FBP and levels 2, 4 and 6 of a commercially available IR algorithm (iDose(4)). CT attenuation and noise were measured in the aorta and two coronary arteries. Both signal-to-noise-ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The amount of lipid, fibrous and calcified plaque components and mean cross-sectional luminal area were analysed using dedicated software. Image noise was reduced by 41.6% (p < 0.0001) and SNR and CNR in the aorta were improved by 73.4% (p < 0.0001) and 72.9% (p < 0.0001) at IR level 6, respectively. IR improved objective image quality measures more in the aorta than in the coronary arteries. Furthermore, IR had no significant effect on measurements of plaque volume and cross-sectional luminal area. The application of IR significantly improves objective image quality, and does not alter quantitative analysis of coronary plaque volume, composition and luminal area. PMID:24046026

Takx, Richard A P; Willemink, Martin J; Nathoe, Hendrik M; Schilham, Arnold M R; Budde, Ricardo P J; de Jong, Pim A; Leiner, Tim

2014-01-01

337

Plaque assay and replication of Tipula iridescent virus in Spodoptera frugiperda ovarian cells.  

PubMed

A plaque assay was developed for the study of Tipula iridescent virus (TIV) replication using a cell line derived from the fall army worm Spodoptera frugiperda (Sf9). Infection and plaque formation were monitored with time by phase contrast microscopy, video and fluorescent light microscopy. Structure of virions, viroplasmic centres and organelles of infected cells were examined by transmission electron microscopy (TEM). After 4 h postinfection, plaques were visibly detected within the cell monolayer by the presence of localized cell damage and production of numerous vesicular-like cytoplasmic structures. Quantitation of virions present per A260 unit of TIV preparation was determined by TEM. The number of visible plaques corresponded to virus concentration and 1 A260 produced approximately 10(5) plaques. DNA hybridization analysis revealed no gross differences in genomic DNA from TIV propagated in either Sf9 cells or wax moth Galleria mellonella larvae. These findings indicate that Sf9 is permissive for replication of TIV and superior by some parameters to other cell lines currently in use for the study of host cell/TIV interactions. PMID:7839010

Czuba, M; Tajbakhsh, S; Walker, T; Dove, M J; Johnson, B F; Seligy, V L

1994-01-01

338

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

339

A New F-18 Labeled PET Agent For Imaging Alzheimer's Plaques  

NASA Astrophysics Data System (ADS)

Amyloid plaques and neurofibrillary tangles are hallmarks of Alzheimer's disease (AD). Advances in development of imaging agents have focused on targeting amyloid plaques. Notable success has been the development of C-11 labeled PIB (Pittsburgh Compound) and a number of studies have demonstrated the utility of this agent. However, the short half life of C-11 (t1/2: 20 min), is a limitation, thus has prompted the development of F-18 labeled agents. Most of these agents are derivatives of amyloid binding dyes; Congo red and Thioflavin. Some of these agents are in clinical trials with encouraging results. We have been exploring new class of agents based on 8-hydroxy quinoline, a weak metal chelator, targeting elevated levels of metals in plaques. Iodine-123 labeled clioquinol showed affinity for amyloid plaques however, it had limited brain uptake and was not successful in imaging in intact animals and humans. We have been successful in synthesizing F-18 labeled 8-hydroxy quinoline. Small animal PET/CT imaging studies with this agent showed high (7-10% ID/g), rapid brain uptake and fast washout of the agent from normal mice brains and delayed washout from transgenic Alzheimer's mice. These promising results encouraged us in further evaluation of this class of compounds for imaging AD plaques.

Kulkarni, Padmakar V.; Vasdev, Neil; Hao, Guiyang; Arora, Veera; Long, Michael; Slavine, Nikolai; Chiguru, Srinivas; Qu, Bao Xi; Sun, Xiankai; Bennett, Michael; Antich, Peter P.; Bonte, Frederick J.

2011-06-01

340

Fully automated carotid plaque segmentation in combined contrast-enhanced and B-mode ultrasound.  

PubMed

Carotid plaque segmentation in B-mode ultrasound (BMUS) and contrast-enhanced ultrasound (CEUS) is crucial to the assessment of plaque morphology and composition, which are linked to plaque vulnerability. Segmentation in BMUS is challenging because of noise, artifacts and echo-lucent plaques. CEUS allows better delineation of the lumen but contains artifacts and lacks tissue information. We describe a method that exploits the combined information from simultaneously acquired BMUS and CEUS images. Our method consists of non-rigid motion estimation, vessel detection, lumen-intima segmentation and media-adventitia segmentation. The evaluation was performed in training (n = 20 carotids) and test (n = 28) data sets by comparison with manually obtained ground truth. The average root-mean-square errors in the training and test data sets were comparable for media-adventitia (411 ± 224 and 393 ± 239 ?m) and for lumen-intima (362 ± 192 and 388 ± 200 ?m), and were comparable to inter-observer variability. To the best of our knowledge, this is the first method to perform fully automatic carotid plaque segmentation using combined BMUS and CEUS. PMID:25542485

Akkus, Zeynettin; Carvalho, Diego D B; van den Oord, Stijn C H; Schinkel, Arend F L; Niessen, Wiro J; de Jong, Nico; van der Steen, Antonius F W; Klein, Stefan; Bosch, Johan G

2015-02-01

341

The role of plaque fissures in unstable angina: fact or fiction?  

PubMed

Several factors may contribute to the development of unstable angina. These include underlying atherosclerosis, mural platelet thrombosis, dynamic stenosis, occlusive spasm and microvascular dysfunctions. Of these, thrombosis is the most visible event, but its actual causes remain elusive. Plaque fissure is widely assumed to be the cause of unstable angina. However, studies have shown no evidence of plaque fissure in about 40% of patients dying from acute coronary syndromes and, conversely, fissured plaques have been found in 10-25% of individuals dying of non-cardiac causes. An inflammatory process may activate the coronary intima and the haemostatic system to produce a platelet-rich thrombus. Activated inflammatory cells produce cytokines which can activate the endothelium making it prothrombotic and vasoconstrictive; they can also produce metalloproteases that can lyse the interstitial matrix. Thus, inflammatory lysis of thin atherosclerotic plaques may also cause plaque fissure at one or more sites. Waxing and waning inflammatory activity may explain the multi-layered thrombi and multiple simultaneous coronary fissure and thrombi that have been described in patients with acute coronary syndromes. PMID:9790281

Maseri, A; Sanna, T

1998-09-01

342

Carotid magnetic resonance imaging for monitoring atherosclerotic plaque progression: a multicenter reproducibility study  

PubMed Central

This study sought to determine the multicenter reproducibility of magnetic resonance imaging (MRI) and the compatibility of different scanner platforms in assessing carotid plaque morphology and composition. A standardized multi-contrast MRI protocol was implemented at 16 imaging sites (GE: 8; Philips: 8). Sixty-eight subjects (61 ± 8 years; 52 males) were dispersedly recruited and scanned twice within 2 weeks on the same magnet. Images were reviewed centrally using a streamlined semiautomatic approach. Quantitative volumetric measurements on plaque morphology (lumen, wall, and outer wall) and plaque tissue composition [lipid-rich necrotic core (LRNC), calcification, and fibrous tissue] were obtained. Inter-scan reproducibility was summarized using the within-subject standard deviation, coefficient of variation (CV) and intraclass correlation coefficient (ICC). Good to excellent reproducibility was observed for both morphological (ICC range 0.98–0.99) and compositional (ICC range 0.88–0.96) measurements. Measurement precision was related to the size of structures (CV range 2.5–4.9 % for morphology, 36–44 % for LRNC and calcification). Comparable measurement variability was found between the two platforms on both plaque morphology and tissue composition. In conclusion, good to excellent inter-scan reproducibility of carotid MRI can be achieved in multicenter settings with comparable measurement precision between platforms, which may facilitate future multicenter endeavors that use serial MRI to monitor atherosclerotic plaque progression. PMID:25216871

Zhao, Xue-Qiao; Balu, Niranjan; Hippe, Daniel S.; Hatsukami, Thomas S.; Isquith, Daniel A.; Yamada, Kiyofumi; Neradilek, Moni B.; Cantón, Gádor; Xue, Yunjing; Fleg, Jerome L.; Desvigne-Nickens, Patrice; Klimas, Michael T.; Padley, Robert J.; Vassileva, Maria T.; Wyman, Bradley T.

2014-01-01

343

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

344

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

345

Pharmacological modulation of cell death in atherosclerosis: a promising approach towards plaque stabilization?  

PubMed Central

Despite tremendous advances over the last 15 years in identifying vulnerable atherosclerotic plaques, the incidence of death and disability caused by such lesions still remains the number one health threat in developed countries. Therefore, new systemic or focal therapies aimed at decreasing the overall burden of disease, and a change to a more benign phenotype, are needed. Because cell death is a prominent feature of advanced atherosclerotic plaques with a major impact on plaque destabilization, an increasing number of compounds targeting the apoptotic or autophagic machinery in atherosclerosis are being explored, predominantly at the preclinical level. This review will provide an overview of these compounds, with a focus on both inhibition and stimulation of cell death, to prevent acute coronary syndromes and sudden cardiac death. PMID:21418184

Martinet, Wim; Schrijvers, Dorien M; De Meyer, Guido RY

2011-01-01

346

Differentiating atherosclerotic plaque burden in arterial tissues using femtosecond CARS-based multimodal nonlinear optical imaging  

PubMed Central

A femtosecond CARS-based nonlinear optical microscope was used to simultaneously image extracellular structural proteins and lipid-rich structures within intact aortic tissue obtained from myocardial infarction-prone Watanabe heritable hyperlipidemic rabbits (WHHLMI). Clear differences in the NLO microscopic images were observed between healthy arterial tissue and regions dominated by atherosclerotic lesions. In the current ex-vivo study, we present a single parameter based on intensity changes derived from multi-channel NLO image to classify plaque burden within the vessel. Using this parameter we were able to differentiate between healthy regions of the vessel and regions with plaque, as well as distinguish plaques relative to the age of the WHHLMI rabbit. PMID:21258446

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

2010-01-01

347

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

348

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

349

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. PMID:25289148

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

2014-01-01

350

Clinical effect of a gel containing Lippia sidoides on plaque and gingivitis control  

PubMed Central

Objective: This parallel controlled clinical trial evaluated the effect of a gel containing Lippia sidoides essential oil on plaque and gingivitis control. Methods: Thirty patients (n=30) were randomly selected and allocated into three groups: Lippia sidoides (LS, n=10), chlorhexidine (CLX, n=10) or placebo (control, n=10). Plaque and bleeding index were recorded at baseline and after three months. All volunteers were instructed to brush with the gel three times a day throughout the experiment period. Results: There was a significant reduction on plaque and gingivitis in the test groups (P<.05), but no statistically significant difference was observed between them (P>.05). Conclusion: A gel preparation containing 10% Lippia sidoides essential oil was an efficient herbal antiplaque and antigingivitis agent. PMID:23408652

Pereira, Sérgio Luis da Silva; Praxedes, Yuri Carvalho Machado; Bastos, Thiago Catunda; Alencar, Phillipe Nogueira Barbosa; da Costa, Flávio Nogueira

2013-01-01

351

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

352

[Effects of dequalinium chloride and sanguinarine on the ultrastructure of early supragingival plaque].  

PubMed

The influence of antimicrobial mouthrinses containing dequalinium chloride or sanguinarine on early plaque formation was assessed in vivo in a clinical-experimental study. Rinses with water served as controls. After 24 and 72 hours, plastic films, which were applied to the buccal surfaces of six upper front teeth at the start of experiment, were removed and processed for transmission electron microscopic study. Dequalinium chloride or sanguinarine applied on plaque resulted in an increased and higher structured surface coating. Degenerated microorganisms were observed and the variety of bacteria seemed to be reduced. Both mouthrinses effected the early supragingival plaque formation. The effect of sanguinarine was more intensive than that of dequalinium chloride. PMID:1818603

Rau, I; Bössmann, K

1991-12-01

353

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

PubMed Central

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

2014-01-01

354

Lower ratio of high-molecular-weight adiponectin level to total may be associated with coronary high-risk plaque  

PubMed Central

Background Although high-molecular-weight (HMW) adiponectin is believed to protect against atherosclerosis, the association between HMW adiponectin and the composition of coronary plaques is unknown. We evaluated whether the HMW to total adiponectin ratio was associated with the presence of coronary plaque and its composition using multi-slice computed tomography coronary angiography (MSCTCA). Methods Serum total and HMW adiponectin levels were measured in 53 consecutive patients (age, 71) with >50% coronary artery stenosis detected by MSCTCA. A low-attenuation coronary plaque was defined as a plaque with a mean CT density <50 Hounsfield units. Multivariate logistic regression analyses were performed to evaluate the predictors of the presence of low-attenuation coronary plaques, which is thought to be high risk, on CT. Results Decreased serum levels of total as well as HMW adiponectin were significantly associated with the presence of at least one calcified or non-calcified coronary artery plaque (total adiponectin level: odds ratio 0.76, 95% CI 0.58–0.99, P?=?0.048; HMW adiponectin level: odds ratio 0.65, 95% CI 0.42–0.99, P?=?0.047). A low ratio of HMW to total adiponectin was significantly associated with the presence of low-attenuation coronary plaques (4.55, 1.94–21.90, P?=?0.049). However, neither the total adiponectin nor the HMW adiponectin level was associated with the presence of low-attenuation coronary plaques. Conclusion Lower total or HMW adiponectin levels are associated with the presence of calcified and non-calcified coronary plaques, whereas a lower ratio of HMW to total adiponectin associated with the presence of low-attenuation coronary plaques (thought to be high risk). Measurement of total and HMW adiponectin levels and the HMW to total adiponectin ratio may be useful for risk stratification of coronary artery plaques. PMID:23497474

2013-01-01

355

An initial evaluation of analyser-based phase-contrast X-ray imaging of carotid plaque microstructure  

PubMed Central

ABSTRACT. Carotid artery plaque instability can result in rupture and lead to ischaemic stroke. Stability of plaques appears to be a function of composition. Current non-invasive imaging techniques are limited in their ability to classify distinct histological regions within plaques. Phase-contrast (PC) X-ray imaging methods are an emerging class of techniques that have shown promise for identifying soft-tissue features without use of exogenous contrast agents. This is the first study to apply analyser-based X-ray PC imaging in CT mode to provide three-dimensional (3D) images of excised atherosclerotic plaques. The results provide proof of principle for this technique as a promising method for analysis of carotid plaque microstructure. Multiple image radiography CT (MIR-CT), a tomographic implementation of X-ray PC imaging that employs crystal optics, was employed to image excised carotid plaques. MIR-CT imaging yields three complementary images of the plaque's 3D X-ray absorption, refraction and scatter properties. These images were compared with histological sections of the tissue. X-ray PC images were able to identify the interface between the plaque and the medial wall. In addition, lipid-rich and highly vascularized regions were visible in the images as well as features depicting inflammation. This preliminary research shows MIR-CT imaging can reveal details about plaque structure not provided by traditional absorption-based X-ray imaging and appears to identify specific histological regions within plaques. This is the first study to apply analyser-based X-ray PC imaging to human carotid artery plaques to identify distinct soft-tissue regions. PMID:23239697

Appel, A A; Chou, C-Y; Larson, J C; Zhong, Z; Schoen, F J; Johnston, C M; Brey, E M; Anastasio, M A

2013-01-01

356

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

357

Effects of Stent Design and Atherosclerotic Plaque Composition on Arterial Wall Biomechanics  

PubMed Central

Purpose: To examine the solid mechanical effects of varying stent design and atherosclerotic plaque stiffness on the biomechanical environment induced in a diseased artery wall model. Methods: Computational modeling techniques were employed to investigate the final radius of the lumen and artery wall stresses after stent implantation. Two stent designs were studied (one stiff and one less stiff). The stenotic artery was modeled as an axisymmetrical diseased vessel with a 20% stenosis by diameter. The material properties of the diseased tissue in the artery models varied. Atherosclerotic plaques half as stiff (0.5×), of equal stiffness (1.0×), or twice as stiff (2.0×) as the artery wall were investigated. Results: Final lumen radius was dependent on stent design, and the stiffer stent deformed the artery to an approximately 10% greater radius than the more compliant design. Alternatively, circumferential stress levels were dependent on both stent design and plaque material properties. Overall, the stiffer stent subjected the artery wall to much higher stress values than the more compliant design, with differences in peak values of 0.50, 0.31, and 0.09 MPa for the 2.0×, 1.0×, and 0.5× stiff plaques, respectively. Conclusion: Evidence suggests that a judicious choice of stent design can minimize stress while maintaining a patent lumen in stenotic arteries. If confronted with a rigid, calcified plaque, stent design is more important, as design differences can impose dramatically different stress fields, while still providing arterial patency. Alternatively, stent design is not as much of an issue when treating a soft, lipid-laden plaque, as stress fields do not vary significantly among stent designs. PMID:19090628

Timmins, Lucas H.; Meyer, Clark A.; Moreno, Michael R.; Moore, James E.

2008-01-01

358

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

359

Quantification of new structural features of coronary plaques by computational post-hoc analysis of virtual histology-intravascular ultrasound images.  

PubMed

Cardiovascular disease and complications are often mediated by the development and rupture of atherosclerotic plaques. Plaque composition is a major factor that determines plaque vulnerability. Intravascular ultrasound (IVUS) and spectral analysis of the radio frequency signal provide an in vivo tissue characterisation of atherosclerotic plaques, known as virtual histology (VH-IVUS). In VH-IVUS analysis, four histological tissue components are classified: fibrous, fibro/fatty, necrotic core and calcium. Existing technology determines only the area of each component within the plaque. Quantitative, objective characterisation of other plaque components' patterns within the plaque is lacking. The aim of this study was to determine new compositional and structural indices which indicate spatial distribution, heterogeneity and dispersity of each VH-IVUS-derived component within the plaque area and also with respect to the plaque-lumen border. We developed an automated computational system in Java for the analysis of both single cross-sectional segments and the whole length of the examined plaque (volumetric analysis). The following parameters were computed: the number of different solid segments and the area of the largest solid segment of each component within the plaque, the per cent of the lumen border that is surrounded by each component, the number of different solid segments and the largest area of a solid segment of each component that adjoins the lumen border. Especially components' localisation in relation to the lumen border may significantly influence plaque vulnerability and plaque-stent interaction, which should be investigated in future clinical studies. PMID:22974224

Papaioannou, Theodore G; Schizas, Dimitrios; Vavuranakis, Manolis; Katsarou, Ourania; Soulis, Dimitrios; Stefanadis, Christodoulos

2014-01-01

360

Finite Element Simulation of Mechanical Behaviors of Coronary Stent in a Vessel with Plaque  

NASA Astrophysics Data System (ADS)

The paper presents results of the finite element analysis of a coronary stent used in a treatment of blood vessel stenosis. This analysis is an efficient way to modify the design of stent and its performance. The work focuses on the Medtronic AVE Modular stent S7. A nonlinear model that contains balloon, stent, and vessel with plaque was used. A bi-linear elasto-plastic material model for stent and hyper-elastic material models for balloon, artery, and plaque were assumed for material modeling. Stress distribution, outer diameter changes and bending behavior were investigated.

Imani, M.; Hojjati, M. H.; Eshghi, N.; Goudarzi, A. M.

2011-12-01

361

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

362

Reduction of connexin 37 expression by RNA interference decreases atherosclerotic plaque formation.  

PubMed

The aim of this study was to examine the effects of connexin 37 (Cx37) interference on atherosclerotic plaques. Lentiviruses expressing small interfering RNA (siRNA) of Cx37 were constructed, and were shown to significantly knockdown the mRNA and protein expression of Cx37 in vitro. Sixty pigs on a high?fat diet were randomly divided into three treatment groups of saline, mock or Cx37 siRNA, to induce plaque formation. The Cx37 lentiviral suspension was transfected into the abdominal aortic plaques of pigs. Plaque characteristics were detected by intravascular ultrasound and the expression of Cx37 mRNA was detected by semi?quantitative polymerase chain reaction. The expression of Cx37 protein was analyzed by western blot analysis. Two months after lentivirus transfection, Cx37 mRNA levels were decreased by 38% in the Cx37 siRNA group, by 60% in the mock?siRNA group and by 63% in the saline group (P<0.05). The mock group showed no significant changes in Cx37 expression as compared with the saline group. Cx37 protein expression was lower in the Cx37 siRNA?treated group as compared with the other groups (0.21±0.07 vs. 0.65±0.06 vs. 0.54±0.07). The percentage of plaque necrosis at 10 months (two months following RNAi) was decreased in the Cx37 siRNA group as compared with that at eight months, prior to RNAi (5.26±2.11 vs. 7.83±1.03%, P<0.05). In the mock?siRNA and saline groups, no differences (P=0.074, 0.061, respectively) were observed. In the Cx37 siRNA group, plaque volumes following 10 months decreased relative to those following eight months, prior to RNAi (21.03±6.24 vs. 31.23±10.23, P<0.01). By contrast, in the mock siRNA and saline groups, plaque volumes after 10 months were increased relative to those following eight months (38.54±13.56 vs. 32.12±11.21 mm3, 37.36±14.21 vs. 30.21±12.02 mm3, P=0.031, P=0.027). Atherosclerotic plaque formation was effectively decreased through the downregulation of Cx37 mRNA using Cx37 siRNA. PMID:25483389

Guo, Suxia; Zhu, Jihong; Yang, Zhenyu; Feng, Jian; Li, Kulin; Wang, Ruxing; Yang, Xiangjun

2015-04-01

363

Influence of lumen shape and vessel geometry on plaque stresses: possible role in the increased vulnerability of a remodelled vessel and the “shoulder” of a plaque  

PubMed Central

Objective: To use finite element modelling to look at the impact of lumen shape and vessel geometry on stress distribution in a vessel. Methods: A finite element model of an atherosclerotic plaque in a coronary artery was created and a non-linear analysis with Ogden strain energy function was done. The three most common shapes seen in an artery with an eccentric plaque—namely an elliptical lumen inside a circular vessel (A), a circular lumen inside an elliptical vessel, typical of a vessel with positive remodelling (B), and a circular lumen inside a circular vessel (C)—were modelled with and without lipid. Stress was analysed in the region of the fibrous cap separating the lumen from the plaque and the region of maximum stress along the circumference of the lumen was noted. Results: In a normal circular shaped coronary artery, the haemodynamic stresses were uniformly distributed all around the circle. However, if the circle was changed to an ellipse, the stresses were redistributed along the major axis and dropped substantially along the minor axis. The stresses in a positively remodelled vessel (B) were significantly greater than in A and C, by almost 100%. Moreover, the haemodynamic stresses increased significantly towards the major axis or the shoulder in A and B, due to lumen shape and vessel geometry alone, even in the absence of lipid in the model. The stresses also had a direct relation with the thickness of the lipid pool and an inverse relation with cap thickness and lumen stenosis. Conclusions: The increased vulnerability of the shoulder region of a plaque and a remodelled coronary artery are due, apart from other factors, to increased biomechanical stresses as a result of lumen shape and vessel geometry. PMID:15774611

Krishna Kumar, R; Balakrishnan, K R

2005-01-01

364

Immunization targeting a minor plaque constituent clears ?-amyloid and rescues behavioral deficits in an Alzheimer's disease mouse model.  

PubMed

Although anti-human ?-amyloid (A?) immunotherapy clears brain ?-amyloid plaques in Alzheimer's disease (AD), targeting additional brain plaque constituents to promote clearance has not been attempted. Endogenous murine A? is a minor A? plaque component in amyloid precursor protein (APP) transgenic AD models, which we show is ?3%-8% of the total accumulated A? in various human APP transgenic mice. Murine A? codeposits and colocalizes with human A? in amyloid plaques, and the two A? species coimmunoprecipitate together from brain extracts. In the human APP transgenic mouse model Tg2576, passive immunization for 8 weeks with a murine-A?-specific antibody reduced ?-amyloid plaque pathology, robustly decreasing both murine and human A? levels. The immunized mice additionally showed improvements in two behavioral assays, odor habituation and nesting behavior. We conclude that passive anti-murine A? immunization clears A? plaque pathology--including the major human A? component--and decreases behavioral deficits, arguing that targeting minor endogenous brain plaque constituents can be beneficial, broadening the range of plaque-associated targets for AD therapeutics. PMID:22608241

Morales-Corraliza, Jose; Schmidt, Stephen D; Mazzella, Matthew J; Berger, Jason D; Wilson, Donald A; Wesson, Daniel W; Jucker, Mathias; Levy, Efrat; Nixon, Ralph A; Mathews, Paul M

2013-01-01

365

Inhibition of progression and stabilization of plaques by postnatal interferon-gamma function blocking in ApoE-knockout mice.  

PubMed

A role of interferon-gamma is suggested in early development of atherosclerosis. However, the role of interferon-gamma in progression and destabilization of advanced atherosclerotic plaques remains unknown. Thus, the aim of this study was to determine whether postnatal inhibition of interferon-gamma signaling could inhibit progression of atherosclerotic plaques and stabilize the lipid- and macrophage-rich advanced plaques. Atherosclerotic plaques were induced in ApoE-knockout (KO) mice by feeding high-fat diet from 8 weeks old (w). Interferon-gamma function was postnatally inhibited by repeated gene transfers of a soluble mutant of interferon-gamma receptors (sIFNgammaR), an interferon-gamma inhibitory protein, into the thigh muscle every 2 weeks. When sIFNgammaR treatment was started at 12 w (atherosclerotic stage), sIFNgammaR not only prevented plaque progression but also stabilized advanced plaques at 16 w: sIFNgammaR decreased accumulations of the lipid and macrophages and increased fibrotic area with more smooth muscle cells. Moreover, sIFNgammaR downregulated expressions of proinflammatory cytokines, chemokines, adhesion molecules, and matrix metalloproteinases but upregulated procollagen type I. sIFNgammaR did not affect serum cholesterol levels. In conclusion, postnatal blocking of interferon-gamma function by sIFNgammaR treatment would be a new strategy to inhibit plaque progression and to stabilize advanced plaques through the antiinflammatory effects. PMID:17495225

Koga, Mitsuhisa; Kai, Hisashi; Yasukawa, Hideo; Yamamoto, Tomoka; Kawai, Yumiko; Kato, Seiya; Kusaba, Ken; Kai, Mamiko; Egashira, Kensuke; Kataoka, Yasufumi; Imaizumi, Tsutomu

2007-08-17

366

ACAT inhibition reduces the progression of pre-existing, advanced atherosclerotic mouse lesions without plaque or systemic toxicity  

PubMed Central

Objective Acyl-CoA:cholesterol acyltransferase (ACAT) converts cholesterol to cholesteryl esters in plaque foam cells. Complete deficiency of macrophage ACAT has been shown to increase atherosclerosis in hypercholesterolemic mice due to cytotoxicity from free cholesterol accumulation, while we previously showed that partial ACAT inhibition by Fujirebio compound F1394 decreased early atherosclerosis development. In this report, we tested F1394 effects on pre-established, advanced lesions of apoE-/- mice. Methods & Results ApoE-/- mice on Western diet for 14 weeks developed advanced plaques, and were either sacrificed (“Baseline”), or continued on Western diet without or with F1394 and sacrificed after 14 more weeks. F1394 was not associated with systemic toxicity. Compared to the baseline group, lesion size progressed in both groups; however, F1394 significantly retarded plaque progression, and reduced plaque macrophage, free and esterified cholesterol, and tissue factor contents compared to the untreated group. Apoptosis of plaque cells was not increased, consistent with the decrease in lesional free cholesterol, plaque necrosis was not increased, and efferocytosis (phagocytic clearance of apoptotic cells) was not impaired. The effects of F1394 were independent of changes in plasma cholesterol levels. Conclusions Partial ACAT inhibition by F1394 lowered plaque cholesterol content and had other antiatherogenic effects in advanced lesions in apoE-/- mice without overt systemic or plaque toxicity, suggesting the continued potential of ACAT inhibition for the clinical treatment of atherosclerosis in spite of recent trial data. PMID:23139293

Rong, James X.; Blachford, Courtney; Feig, Jonathan E.; Bander, Ilda; Mayne, Jeffrey; Kusunoki, Jun; Miller, Christine; Davis, Matthew; Wilson, Martha; Dehn, Shirley; Thorp, Edward; Tabas, Ira; Taubman, Mark B.; Rudel, Lawrence L.; Fisher, Edward A.

2013-01-01

367

Effect of Sucralose – Alone or Bulked with Maltodextrin and\\/or Dextrose – on Plaque pH in Humans  

Microsoft Academic Search

Sucralose is a safe, intensely sweet, noncaloric sucrose derivative that has been shown to be noncariogenic. The purpose of the present study was to compare the effects on plaque pH in vivo of sucralose in iced tea (alone or bulked with maltodextrin or with maltodextrin\\/dextrose) with sucrose in iced tea. Fourteen subjects, with DMFT > 7 and an acidogenic plaque,

C. M. Meyerowitz; E. P. Syrrakou; R. F. Raubertas

1996-01-01

368

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

369

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

370

The Efficacy and Safety of Topically Applied Indigo Naturalis Ointment in Patients with Plaque-Type Psoriasis  

Microsoft Academic Search

Background: It has been reported in the Chinese literature that indigo naturalis exhibits potential antipsoriatic effects in systemic therapy. Objective: To evaluate the efficacy and safety of topically applied indigo naturalis on treating plaque-type psoriasis and to analyze the histological change in skin tissues. Methods: Fourteen patients with chronic plaque psoriasis were enrolled. The patients were topically applied with either

Yin-Ku Lin; Wen-Rou Wong; Ya-Ching Chang; Chee-Jen Chang; Pei-Kwei Tsay; Shu-Chen Chang; Jong-Hwei Su Pang

2007-01-01

371

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

372

Diminished Omega-3 Fatty Acids are Associated with Carotid Plaques from Neurologically Symptomatic Patients: Implications for Carotid Interventions  

PubMed Central

The omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are prevalent in fish oil and their cardioprotective effects are thought to be mediated by anti-inflammatory mechanisms. The aim of this study is to determine whether omega-3 fatty acids are associated with carotid plaques from neurologically symptomatic patients. Plaques were obtained from 41 patients (mean age 62 [44 – 84]; 24-asymptomatic, 17-symptomatic). Intra-plaque lipids were assessed with mass spectrometry. Compared to asymptomatic patients, significantly diminished omega-3 fatty acids DHA (545.8 ± 98 ng/g vs. 270.7 ± 19.6 ng/g, p=0.0096) and EPA (385.9 ± 68 ng/g vs. 216.4 ± 17.6 ng/g, p=0.0189) were found in carotid plaques from neurologically symptomatic patients. However, no differences were found in the levels of the omega-6 fatty acid arachidonic acid (p=0.2003). Immunohistochemistry and ELISA analysis (CD68+ cells, 0.461 ± 0.04 vs. 0.312 ± 0.03, p=0.003) demonstrated an increased inflammatory infiltrate in plaques from neurologically symptomatic, compared to asymptomatic, patients. Carotid plaques from neurologically symptomatic patients are inflammatory and have decreased intra-plaque levels of omega-3 fatty acids. Future trials will determine whether interventions that increase omega-3 fatty acid incorporation into carotid plaques prevent stroke and improve the safety of carotid interventions. PMID:19733689

Bazan, Hernan A.; Lu, Yan; Thoppil, Deepu; Fitzgerald, Tamara N.; Hong, Song; Dardik, Alan

2009-01-01

373

Detecting atheromatous plaques in the aortic arch or supra-aortic arteries for more accurate stroke subtype classification.  

PubMed

Introduction. To investigate the correlations of atheromatous plaques in the aortic arch or supra-aortic arteries with intracranial arterial stenosis and carotid plaques in stroke patients, and to determine whether taking these plaques into account will reduce the proportion of patients in the undetermined etiology group. Methods. We prospectively enrolled 308 ischemic stroke patients, whose clinical characteristics and A-S-C-O classifications were compared with analyses of intracranial arteries, carotid arteries, aortic arch, and supra-aortic arteries. Results. 125(40.6%) patients had plaques in the aortic arch or supra-aortic arteries, of which 106 (84.8%) had complex plaques. No correlations were observed between these plaques and carotid plaques (?p = 0.283) or intracranial arterial stenosis (?p = 0.097). After detecting the mobile thrombi in the aortic arch and supra-aortic arteries, the proportion of patients in the atherothrombosis group was increased from 33.8% to 55.5% (?p = 0.00), whereas the proportion of patients in stroke of undetermined etiology group was decreased from 19.2% to 11.0% (?p = 0.00). Discussion. Examining only the carotid and intracranial arteries may not provide adequate information about large arteries in stroke patients. Therefore, it would be better to include a search for relevant plaques in the aortic arch or supra-aortic arteries in modern stroke workup, for it may lead to more accurate stroke subtype classification and guide secondary prevention. PMID:24738734

Cui, Xiaoyang; Wu, Simiao; Zeng, Quantao; Xiao, Jiahe; Liu, Ming

2015-02-01

374

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

375

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

376

Epigenome-Guided Analysis of the Transcriptome of Plaque Macrophages during Atherosclerosis Regression Reveals Activation of the Wnt Signaling Pathway  

PubMed Central

We report the first systems biology investigation of regulators controlling arterial plaque macrophage transcriptional changes in response to lipid lowering in vivo in two distinct mouse models of atherosclerosis regression. Transcriptome measurements from plaque macrophages from the Reversa mouse were integrated with measurements from an aortic transplant-based mouse model of plaque regression. Functional relevance of the genes detected as differentially expressed in plaque macrophages in response to lipid lowering in vivo was assessed through analysis of gene functional annotations, overlap with in vitro foam cell studies, and overlap of associated eQTLs with human atherosclerosis/CAD risk SNPs. To identify transcription factors that control plaque macrophage responses to lipid lowering in vivo, we used an integrative strategy – leveraging macrophage epigenomic measurements – to detect enrichment of transcription factor binding sites upstream of genes that are differentially expressed in plaque macrophages during regression. The integrated analysis uncovered eight transcription factor binding site elements that were statistically overrepresented within the 5? regulatory regions of genes that were upregulated in plaque macrophages in the Reversa model under maximal regression conditions and within the 5? regulatory regions of genes that were upregulated in the aortic transplant model during regression. Of these, the TCF/LEF binding site was present in promoters of upregulated genes related to cell motility, suggesting that the canonical Wnt signaling pathway may be activated in plaque macrophages during regression. We validated this network-based prediction by demonstrating that ?-catenin expression is higher in regressing (vs. control group) plaques in both regression models, and we further demonstrated that stimulation of canonical Wnt signaling increases macrophage migration in vitro. These results suggest involvement of canonical Wnt signaling in macrophage emigration from the plaque during lipid lowering-induced regression, and they illustrate the discovery potential of an epigenome-guided, systems approach to understanding atherosclerosis regression. PMID:25474352

Menon, Prashanthi; Podolsky, Irina; Feig, Jonathan E.; Aderem, Alan; Fisher, Edward A.; Gold, Elizabeth S.

2014-01-01

377

Regression of Atherosclerosis Is Characterized by Broad Changes in the Plaque Macrophage Transcriptome  

E-print Network

responsible for cellular movement (e.g. actin and myosin) were up-regulated whereas genes related to cell University School of Medicine, New York, New York, United States of America, 2 Department of Cardiovascular adhesion (e.g. cadherins, vinculin) were down-regulated. In addition, CD68+ cells from regressing plaque

Statnikov, Alexander

378

Automated in vivo segmentation of carotid plaque MRI with Morphology-Enhanced probability maps.  

PubMed

MRI is a promising noninvasive technique for characterizing atherosclerotic plaque composition in vivo, with an end-goal of assessing plaque vulnerability. Because of limitations arising from acquisition time, achievable resolution, contrast-to-noise ratio, patient motion, and the effects of blood flow, automatically identifying plaque composition remains a challenging task in vivo. In this article, a segmentation method using maximum a posteriori probability Bayesian theory is presented that divides axial, multi-contrast-weighted images into regions of necrotic core, calcification, loose matrix, and fibrous tissue. Key advantages of the method are that it utilizes morphologic information, such as local wall thickness, and coupled active contours to limit the impact from noise and artifacts associated with in vivo imaging. In experiments involving 142 sets of multi-contrast images from 26 subjects undergoing carotid endarterectomy, segmented areas of each of these tissues per slice agreed with histologically confirmed areas with correlations (R(2)) of 0.78, 0.83, 0.41, and 0.82, respectively. In comparison, manually identifying areas blinded to histology yielded correlations of 0.71, 0.76, 0.33, and 0.78, respectively. These results show that in vivo automatic segmentation of carotid MRI is feasible and comparable to or possibly more accurate than manual review for quantifying plaque composition. PMID:16470594

Liu, Fei; Xu, Dongxiang; Ferguson, Marina S; Chu, Baocheng; Saam, Tobias; Takaya, Norihide; Hatsukami, Thomas S; Yuan, Chun; Kerwin, William S

2006-03-01

379

Histopathologic findings in eyes treated with a ruthenium plaque for uveal melanoma  

Microsoft Academic Search

Fifty-six globes that had to be enucleated following ruthenium plaque therapy were examined histopathologically. These eyes account for 10% of all uveal melanomas treated at the University Eye Clinic Essen up until 1985. All but one revealed at least some supposedly viable tumor cells. The most prominent findings within the tumors were tumor cell necrosis, vacuolization and balloon cell degeneration,

Elmar Messmer; Norbert Bornfeld; Michael Foerster; Harald Schilling; Achim Wessing

1992-01-01

380

Increased brain iron coincides with early plaque formation in a mouse model of Alzheimer's disease  

SciTech Connect

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 cortex and hippocampus using X-ray fluorescence microscopy (XFM). We found that iron in the cortex was 34% higher than age-matched controls at an early stage, corresponding to the commencement of plaque formation. The elevated iron was not associated with the amyloid plaques. Interestingly, none of the metal ions were elevated in the amyloid plaques until the latest time point (56 weeks), where only the Zn content was significantly elevated by 38%. Since neuropathological changes in human Alzheimer's disease are presumed to occur years before the first cognitive symptoms appear, quantification of brain iron content could be a powerful marker for early diagnosis of Alzheimer's disease.

Leskovjan, A.C.; Miller, L.; Kretlow, A.; Lanzirotti, A.; Barrea,R.; Vogt, S.

2010-11-23

381

Carotid ultrasound symptomatology using atherosclerotic plaque characterization: a class of Atheromatic systems.  

PubMed

In this paper, we present a Computer Aided Diagnosis (CAD) based technique (Atheromatic system) for classification of carotid plaques in B-mode ultrasound images into symptomatic or asymptomatic classes. This system, called Atheromatic, has two steps: (i) feature extraction using a combination of Discrete Wavelet Transform (DWT) and averaging algorithms and (ii) classification using Support Vector Machine (SVM) classifier for automated decision making. The CAD system was built and tested using a database consisting of 150 asymptomatic and 196 symptomatic plaque regions of interests which were manually segmented. The ground truth of each plaque was determined based on the presence or absence of symptoms. Three-fold cross-validation protocol was adapted for developing and testing the classifiers. The SVM classifier with a polynomial kernel of order 2 recorded the highest classification accuracy of 83.7%. In the clinical scenario, such a technique, after much more validation, can be used as an adjunct tool to aid physicians by giving a second opinion on the nature of the plaque (symptomatic/asymptomatic) which would help in the more confident determination of the subsequent treatment regime for the patient. PMID:23366606

Acharya, U Rajendra; S, Vinitha Sree; Molinari, Filippo; Saba, Luca; Nicolaides, Andrew; Shafique, Shoaib; Suri, Jasjit S

2012-01-01

382

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

383

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

384

Pravastatin inhibits plaque rupture and subsequent thrombus formation in atherosclerotic rabbits with hyperlipidemia.  

PubMed

Previous studies have demonstrated that statin can reduce the risk of acute coronary syndrome. In order to explore the mechanism, we observed the effects of pravastatin on plaque stability in atherosclerotic rabbits. Sixteen male rabbits were fed with a high fat diet following their damaged abdominal aortic endothelium by using catheter. Eight of them were administered with pravastatin (10 mg·kg(-1)·d(-1)) for 4 weeks. Then the rabbit atherosclerotic plaque rupture and thrombosis were triggered by injection of viper venom and histamine. Compared with model group, the thrombus area on aorta in pravastatin-treated group was reduced. Fibre cap on plaque was more thick and integrant, and inflammatory cell infiltration was also decreased. Serum total cholesterol, triglyceride, low density lipoprotein-cholesterol and contents of cholesterol in abdominal aorta were decreased. 6-Keto-prostaglandin F(1?) (6-keto-PGF(1?)) level and ratio of 6-keto-PGF(1?)/thromboxane B(2) (TXB(2)) in aorta were significantly increased. These results suggested that pravastatin could increase plaque stability and inhibit thrombosis through both lipid-dependent and lipid-independent way. PMID:23207681

Wu, Gang; Xie, Qiang; Xu, Lin; Jiang, Hong; Huang, Zhengrong; Huang, Congxin

2013-01-01

385

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

Microsoft Academic Search

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

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

2009-01-01

386

Degenerative collagenous plaque of the hand (linear keratoelastoidosis of the hands). A variant of acrokeratoelastosis.  

PubMed

Clinical and histological features of three examples of degenerative collagenous plaques of the hands in Indian housewives have been described in detail in order to focus attention on a hitherto uncommon entity. Household trauma has been incriminated as the precipitating or a triggering factor in these cases. PMID:7398997

Sehgal, V N; Singh, M; Korrane, R V; Nayyar, M; Chandra, M

1980-01-01

387

Mathematical modelling of atheroma plaque formation and development in coronary arteries  

PubMed Central

Atherosclerosis is a vascular disease caused by inflammation of the arterial wall, which results in the accumulation of low-density lipoprotein (LDL) cholesterol, monocytes, macrophages and fat-laden foam cells at the place of the inflammation. This process is commonly referred to as plaque formation. The evolution of the atherosclerosis disease, and in particular the influence of wall shear stress on the growth of atherosclerotic plaques, is still a poorly understood phenomenon. This work presents a mathematical model to reproduce atheroma plaque growth in coronary arteries. This model uses the Navier–Stokes equations and Darcy's law for fluid dynamics, convection–diffusion–reaction equations for modelling the mass balance in the lumen and intima, and the Kedem–Katchalsky equations for the interfacial coupling at membranes, i.e. endothelium. The volume flux and the solute flux across the interface between the fluid and the porous domains are governed by a three-pore model. The main species and substances which play a role in early atherosclerosis development have been considered in the model, i.e. LDL, oxidized LDL, monocytes, macrophages, foam cells, smooth muscle cells, cytokines and collagen. Furthermore, experimental data taken from the literature have been used in order to physiologically determine model parameters. The mathematical model has been implemented in a representative axisymmetric geometrical coronary artery model. The results show that the mathematical model is able to qualitatively capture the atheroma plaque development observed in the intima layer. PMID:24196695

Cilla, Myriam; Peña, Estefanía; Martínez, Miguel A.

2014-01-01

388

Leonid Breznev and Richard Nixon examine plaques presented by Skylab crew  

NASA Technical Reports Server (NTRS)

Leonid I. Breznev, General Secretary of the Communist Party, Union of Soviet Socialist Republics, and President Richard M. Nixon, during ceremonies at the Western White House in San Clemente, California, examine plaques presented by Skylab astronauts Charles Conrad Jr., center; Joseph P. Kerwin, second from right; and Paul J. Weitz, left.

1973-01-01

389

Fluorescence in situ hybridization for direct visualization of gram-negative anaerobes in subgingival plaque samples.  

PubMed

Fluorescent oligonucleotide probes complementary to variable regions of Porphyromonas gingivalis and Bacteroides forsythus 16S ribosomal RNA were used to identify these organisms in smears of formaldehyde-fixed subgingival plaque samples from patients suffering from periodontitis. Fluorescence in situ hybridization represents a useful method for assessing the microbial ecology of the periodontal flora. PMID:7686071

Gersdorf, H; Pelz, K; Göbel, U B

1993-03-01

390

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

PubMed Central

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; Kjær, Andreas

2014-01-01

391

Microglia constitute a barrier that prevents neurotoxic protofibrillar A?42 hotspots around plaques.  

PubMed

In Alzheimer's disease (AD), ?-amyloid (A?) plaques are tightly enveloped by microglia processes, but the significance of this phenomenon is unknown. Here we show that microglia constitute a barrier with profound impact on plaque composition and toxicity. Using high-resolution confocal and in vivo two-photon imaging in AD mouse models, we demonstrate that this barrier prevents outward plaque expansion and leads to compact plaque microregions with low A?42 affinity. Areas uncovered by microglia are less compact but have high A?42 affinity, leading to the formation of protofibrillar A?42 hotspots that are associated with more severe axonal dystrophy. In ageing, microglia coverage is reduced leading to enlarged protofibrillar A?42 hotspots and more severe neuritic dystrophy. CX3CR1 gene deletion or anti-A? immunotherapy causes expansion of microglia coverage and reduced neuritic dystrophy. Failure of the microglia barrier and the accumulation of neurotoxic protofibrillar A? hotspots may constitute novel therapeutic and clinical imaging targets for AD. PMID:25630253

Condello, Carlo; Yuan, Peng; Schain, Aaron; Grutzendler, Jaime

2015-01-01

392

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

393

FACTORS AFFECTING IRON SULFIDE-ENHANCED BACTERIOPHAGE PLAQUE ASSAYS IN SALMONELLA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Formation of iron sulfide from reaction of ferric ions in bacteriological media with hydrogen sulfide (H2S) produced by bacteria has been exploited to enhance contrast of bacteriophage plaques in sulfate-reducing strains of Salmonella. Ferric ammonium citrate (FAC) and sodium thiosulfate (ST) added ...

394

42. Perimeter acquisition radar building plaque, commemorating parransferral from U.S. ...  

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

42. Perimeter acquisition radar building plaque, commemorating parransferral from U.S. Army ballistic missile defense organization to U.S. Air Force aerospace defense command (dated 1 October 1977) - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

395

Molecular detection and corelation of Helicobacter pylori in dental plaque and gastric biopsies of dyspeptic patients  

PubMed Central

Helicobacter pylori is a microaerophilic organism, which colonizes in the gastric mucosa. Its role in etiology and development of acute and chronic gastritis and peptic ulcer diseases is scientifically proved. Oral cavity especially supragingival, subgingival plaque and so forth simulate the same microaerophilic environment favorable for the growth of this bacterium. Aim: Detection of H. pylori simultaneously in the oral cavity and gastric mucosa of patients suffering from gastric pathologies. Objectives: To detect H. pylori in the oral cavity and gastric mucosa using endoscopy, urease test and real-time polymerase chain reaction (PCR) (urease A gene). Determining its association and corelation with patient demographics, oral hygiene maintenance and periodontal disease status. Materials and Methods: Endoscopic examination, oral findings oral hygiene index-simplified (OHI-S) and community periodontal index and treatment needs (CPITN) indices were recorded. Antral biopsies and supragingival plaque samples were taken from 56 dyspeptic adult patients. The collected samples were subjected to histological examination, urease broth test and urease A gene amplification using real-time PCR. Result: H. pylori was detected in the supragingival plaque of individuals with H. pylori-induced gastric diseases using rapid urease test and real-time PCR analysis. Occurrence of same strain of H. pylori simultaneously in plaque and gastric mucosa was observed. Positive correlation was obtained between the collected indices and quantity of H. pylori colonization. PMID:24959032

Bharath, T Sreenivasa; Reddy, M Sesha; Dhanapal, Raghu; Raj Kumar, N Govind; Neeladri Raju, PV; Saraswathi, TR

2014-01-01

396

Comparison of Erythritol and Xylitol Saliva Stimulants in the Control of Dental Plaque and Mutans Streptococci  

Microsoft Academic Search

The effect of 2–month usage of saliva–stimulating pastils containing either erythritol or xylitol was studied in a cohort of 30 subjects assigned to the respective polyol groups (n = 15). The daily consumption level of both polyols was 5.2 g, used in 5 daily chewing episodes. The mean weight of total plaque mass (collectable during a standard period of 3

K. K. Mäkinen; K. P. Isotupa; T. Kivilompolo; P. L. Mäkinen; J. Toivanen; E. Söderling

2001-01-01

397

Inhaled diesel emissions alter atherosclerotic plaque composition in ApoE ?\\/? mice  

Microsoft Academic Search

Recent epidemiological studies suggest that traffic-related air pollution may have detrimental effects on cardiovascular health. Previous studies reveal that gasoline emissions can induce several enzyme pathways involved in the formation and development of atherosclerotic plaques. As a direct comparison, the present study examined the impact of diesel engine emissions on these pathways, and further examined the effects on vascular lesion

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

2010-01-01

398

A new approach for improving coronary plaque component analysis based on intravascular ultrasound images.  

PubMed

Virtual histology intravascular ultrasound (VH-IVUS) is a clinically available technique for atherosclerosis plaque characterization. It, however, suffers from a poor longitudinal resolution due to electrocardiogram (ECG)-gated acquisition. This article presents an effective algorithm for IVUS image-based histology to overcome this limitation. After plaque area extraction within an input IVUS image, a textural analysis procedure consisting of feature extraction and classification steps is proposed. The pixels of the extracted plaque area excluding the shadow region were classified into one of the three plaque components of fibro-fatty (FF), calcification (CA) or necrotic core (NC) tissues. The average classification accuracy for pixel and region based validations is 75% and 87% respectively. Sensitivities (specificities) were 79% (85%) for CA, 81% (90%) for FF and 52% (82%) for NC. The kappa (kappa) = 0.61 and p value = 0.02 indicate good agreement of the proposed method with VH images. Finally, the enhancement in the longitudinal resolution was evaluated by reconstructing the IVUS images between the two sequential IVUS-VH images. PMID:20691915

Taki, Arash; Hetterich, Holger; Roodaki, Alireza; Setarehdan, S K; Unal, Gozde; Rieber, Johannes; Navab, Nassir; König, Andreas

2010-08-01

399

Intravascular detection of inflamed atherosclerotic plaques using a fluorescent photosensitizer targeted to the scavenger receptor  

PubMed Central

Inflammation plays an important role in the pathophysiology of atherosclerotic disease. We have previously shown that the targeted photosensitizer chlorin (e6) conjugated with maleylated albumin (MA-ce6) is taken up by macrophages via the scavenger receptor with high selectivity. In a rabbit model of inflamed plaque in New Zealand white rabbits via balloon injury of the aorto-iliac arteries and high cholesterol diet we showed that the targeted conjugate showed specificity towards plaques compared to free ce6. We now show that an intravascular fiber-based spectrofluorimeter advanced along the -iliac vessel through blood detects 24-fold higher fluorescence in atherosclerotic vessels compared to control rabbits (p < 0.001 ANOVA). Within the same animals, signal derived from the injured iliac artery was 16-fold higher than the contralateral uninjured iliac (p < 0.001). Arteries were removed and selective accumulation of MA-ce6 in plaques was confirmed using: (1) surface spectrofluorimetry, (2) fluorescence extraction of ce6 from aortic segments, and (3) confocal microscopy. Immunohistochemical analysis of the specimens showed a significant correlation between MA-ce6 uptake and RAM-11 macrophage staining (R = 0.83, p < 0.001) and an inverse correlation between MA-ce6 uptake and smooth muscle cell staining (R=?0.74, p < 0.001). MA-ce6 may function as a molecular imaging agent to detect and/or photodynamically treat inflamed plaques. PMID:18167594

Tawakol, Ahmed; Castano, Ana P.; Gad, Faten; Zahra, Touqir; Bashian, Gregory; Migrino, Raymond Q.; Ahmadi, Atosa; Stern, Jeremy; Anatelli, Florencia; Chirico, Stephanie; Shirazi, Azadeh; Syed, Sakeenah; Fischman, Alan J.; Muller, James E.

2010-01-01

400

Optimal parameters for near infrared fluorescence imaging of amyloid plaques in Alzheimer's disease mouse models  

NASA Astrophysics Data System (ADS)

Amyloid-? plaques are an Alzheimer's disease biomarker which present unique challenges for near-infrared fluorescence tomography because of size (<50 µm diameter) and distribution. We used high-resolution simulations of fluorescence in a digital Alzheimer's disease mouse model to investigate the optimal fluorophore and imaging parameters for near-infrared fluorescence tomography of amyloid plaques. Fluorescence was simulated for amyloid-targeted probes with emission at 630 and 800 nm, plaque-to-background ratios from 1-1000, amyloid burden from 0-10%, and for transmission and reflection measurement geometries. Fluorophores with high plaque-to-background contrast ratios and 800 nm emission performed significantly better than current amyloid imaging probes. We tested idealized fluorophores in transmission and full-angle tomographic measurement schemes (900 source-detector pairs), with and without anatomical priors. Transmission reconstructions demonstrated strong linear correlation with increasing amyloid burden, but underestimated fluorescence yield and suffered from localization artifacts. Full-angle measurements did not improve upon the transmission reconstruction qualitatively or in semi-quantitative measures of accuracy; anatomical and initial-value priors did improve reconstruction localization and accuracy for both transmission and full-angle schemes. Region-based reconstructions, in which the unknowns were reduced to a few distinct anatomical regions, produced highly accurate yield estimates for cortex, hippocampus and brain regions, even with a reduced number of measurements (144 source-detector pairs).

Raymond, S. B.; Kumar, A. T. N.; Boas, D. A.; Bacskai, B. J.

2009-10-01

401

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

402

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

403

Lipoprotein lipase is synthesized by macrophage-derived foam cells in human coronary atherosclerotic plaques.  

PubMed Central

Lipoprotein lipase (LPL), hydrolyzes the core triglycerides of lipoproteins, thereby playing a role in their maturation. LPL may be important in the metabolic pathways that lead to atherosclerosis, since it is secreted in vitro by both of the predominant cell types of the atherosclerotic plaque, i.e., macrophages and smooth muscle cells. Because of uncertainty concerning the primary cellular source of LPL in atherosclerotic lesions, in situ hybridization assays for LPL mRNA were performed on 12