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1

Vulnerable Plaque  

MedlinePLUS

... pH of plaque. Can vulnerable plaque be prevented? Patients can lower their C-reactive protein levels in the same ways that they can cut their heart attack risk: take aspirin, eat a proper diet, quit smoking, and begin an exercise program. Researchers also think that obesity and diabetes ...

2

Dental plaque formation  

Microsoft Academic Search

Dental plaque is a complex biofilm that accumulates on the hard tissues (teeth) in the oral cavity. Although over 500 bacterial species comprise plaque, colonization follows a regimented pattern with adhesion of initial colonizers to the enamel salivary pellicle followed by secondary colonization through interbacterial adhesion. A variety of adhesins and molecular interactions underlie these adhesive interactions and contribute to

Burton Rosan; Richard J Lamont

2000-01-01

3

Atherosclerotic carotid plaque segmentation  

Microsoft Academic Search

Atherosclerosis is the major cause of heart attack and stroke in the western world. In this paper we present a computerized method for segmenting the athrerosclerotic carotid plaque from ultrasound images. The method uses the blood flow image first to detect the initial contour of the plaque, and then despeckle filtering and snakes to deform the initial contour for best

C. P. Loizou; C. S. Pattichis; R. S. H. Istepanian; M. Pantziaris; A. Nicolaides

2004-01-01

4

Biomarkers of plaque instability.  

PubMed

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

Shah, P K

2014-12-01

5

Sintered plaque characteristics  

NASA Technical Reports Server (NTRS)

The structural transformations occurring during sintering, the fabrication of a slurry produced sintered plaque, are detailed. Degradation of the positive electrode in performance in cycling in a nickel hydrogen battery were traced to the quality of the sintered plaque. Electrode degradation was found to be a limiting factor in the battery cycle life. Details of microstructural characterization and distribution of pores, examination of plastic flow during shrinkage, and observations of the rounding of nickel powder particles during the slurry process are presented.

Vaidyanathan, H.

1982-01-01

6

10. Detail, dedication plaque on the bridge's northeast end (plaque ...  

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

10. Detail, dedication plaque on the bridge's northeast end (plaque on southwest end of bridge is identical - Big Cottonwood River Bridge No. 246, Spanning Big Cottonwood River at Cottonwood Street (City Road No. 165), New Ulm, Brown County, MN

7

Psoriasis (chronic plaque)  

PubMed Central

Introduction Psoriasis is a chronic inflammatory skin disease that affects 1% to 3% of the population, in some people causing changes to the nails and joints as well as skin lesions. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of non-drug (other than ultraviolet light), topical drug, ultraviolet light, and systemic drug treatments for chronic plaque psoriasis? What are the effects of combined treatment with drugs plus ultraviolet light for chronic plaque psoriasis? What are the effects of combined systemic plus topical drug treatments for chronic plaque psoriasis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2007 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 122 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: acupuncture, adding calcipotriol (topical) to psoralen plus ultraviolet light A or ultraviolet light B, adding oral retinoids to psoralen plus ultraviolet A (PUVA), alefacept, balneotherapy, ciclosporin, dithranol, T cell-targeted therapies, cytokine blocking agents, emollients (alone or plus ultraviolet light B), etanercept, fish oil supplementation, fumaric acid derivatives, Goeckerman treatment, heliotherapy, infliximab, Ingram regimen, keratolytics (salicylic acid, urea), leflunomide, methotrexate, oral pimecrolimus, oral retinoids (alone or with ultraviolet light B), phototherapy plus balneotherapy, psoralen plus ultraviolet A, psychotherapy, systemic drug treatments plus topical vitamin D derivatives, tars, tazarotene, topical corticosteroids (alone or plus oral retinoids), topical Vitamin D derivatives, ultraviolet light A, and ultraviolet light B. PMID:19445765

2009-01-01

8

Evolution of Atherosclerotic Carotid Plaque Morphology: Do Ulcerated Plaques Heal? A Serial Multidetector CT Angiography Study  

Microsoft Academic Search

Background: Atherosclerotic carotid plaque rupture may lead to thromboembolization, causing transient ischemic attack or ischemic stroke. Carotid plaque ulceration on angiography is associated with plaque rupture. Although healing of ruptured plaques has been described in coronary arteries, little is known about the natural development of plaque ulcerations in carotid arteries. We therefore explored the evolution of carotid plaque surface morphology

M. J. van Gils; P. J. Homburg; S. Rozie; T. T. de Weert; D. W. J. Dippel; A. van der Lugt

2011-01-01

9

Denitrification in human dental plaque  

Microsoft Academic Search

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

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

2010-01-01

10

Pioneer F Plaque Location  

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

1972-01-01

11

Making a Lightweight Battery Plaque  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

12

Denture plaque and denture cleansers.  

PubMed

Literature concerning the relationship between denture plaque, oral pathology, and the nature and effectiveness of the products commercially available for cleaning dentures has been reviewed. The literature reports indicate that (1) plaque on the tissue surface side of the denture is unquestionably a major etiologic factor in the pathogenesis of denture stomatitis, inflammatory papillary hyperplasia, and chronic candidiasis and (2) there are shortcomings in the popular products used by the public to clean their dentures. The protocol and results of a study to test the plaque removal effectiveness of a new denture cleansing product are described. In this study, the plaque removal effectiveness of the ultrasonic device tested, when used with water alone, was found to be substantially greater than that of two popular alkaline-peroxide soak-type denture cleansers, Efferdent and Polident. PMID:6939844

Abelson, D C

1981-04-01

13

Dental plaque identification at home  

MedlinePLUS

... special tablets that contain a red dye that stains the plaque. One tablet is chewed thoroughly, moving ... this method is that it leaves no pink stains in the mouth. In the office, dentists are ...

14

Chromosomal alterations in atherosclerotic plaques.  

PubMed

Alterations of chromosomes 7 and 11 have been involved in the progression of atherosclerosis. Twenty-three carotid endarterectomy specimens were studied for the presence of alterations in chromosomes 7 and 11, and fibroblastic growth factor-3 (FGF-3) gene amplification. Besides classic histological stainings, immunophenotyping of cellular and vascular components and fluorescence in situ hybridization (FISH) were performed. At the caps, unstable plaques (n=18) showed inflammatory infiltration of macrophages, smooth muscle cells, and T-lymphocytes. Specifically in these regions, the FISH showed varying percentages of trisomy (15/18) and tetrasomy (8/15) of chromosome 7. In four cases polisomy 7 was noted in some nuclei. Monosomy of chromosome 11 and gene amplification of FGF-3 gene was observed. The FISH of the five stable plaques and normal arterial walls showed no chromosome alterations; furthermore, chromosome 3, which is not involved in atherosclerotic progression, presented a normal ploidy of smooth muscle cells in stable and unstable plaques and normal arterial walls. In conclusion, chromosome 7 and 11 alterations and FGF-3 gene amplification are components of unstable plaques, and might contribute to the evolution of stable plaques into complicated plaques. PMID:11257279

Matturri, L; Cazzullo, A; Turconi, P; Lavezzi, A M; Vandone, P L; Gabrielli, L; Fernández Alonso, G; Grana, D; Milei, J

2001-02-15

15

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

16

[Magnetic resonance imaging of atherosclerotic plaque].  

PubMed

Recent advances in terms of spatial and temporal resolution have enabled magnetic resonance imaging (MRI) to be used to display atherosclerotic plaque. MRI permits not only to detect atherosclerotic lesions but also enables determination of plaque volume and plaque characterization. It allows to display different plaque components such as lipid core, fibrous cap, calcium, and thrombus. To improve the spatial resolution, different invasive approaches based on intravascular coils have been evaluated. Novel contrast agent developments aim at the detection of inflammatory plaque activity in order to identify lesions with a high vascular risk (vulnerable plaque). PMID:14564414

Ruehm, Stefan G

2003-09-01

17

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

18

Imaging Atherosclerosis and Vulnerable Plaque  

PubMed Central

Identifying patients at high risk for an acute cardiovascular event such as myocardial infarction or stroke and assessing the total atherosclerotic burden are clinically important. Currently available imaging modalities can delineate vascular wall anatomy and, with novel probes, target biologic processes important in plaque evolution and plaque stability. Expansion of the vessel wall involving remodeling of the extracellular matrix can be imaged, as can angiogenesis of the vasa vasorum, plaque inflammation, and fibrin deposits on early nonocclusive vascular thrombosis. Several imaging platforms are available for targeted vascular imaging to acquire information on both anatomy and pathobiology in the same imaging session using either hybrid technology (nuclear combined with CT) or MRI combined with novel probes targeting processes identified by molecular biology to be of importance. This article will discuss the current state of the art of these modalities and challenges to clinical translation. PMID:20395341

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

2010-01-01

19

Apollo 16 Moon Plaque Installation  

NASA Technical Reports Server (NTRS)

Working inside the Apollo 16 Saturn V space vehicle at the launch pad, Grumman Aerospace Corporation technician Ken Crow attaches a plaque bearing the names and signatures of the Apollo 16 crew to the front leg of the lunar module's descent stage. The stainless steel plaque, which will remain on the lunar surface, measures 18 by 23 cm (seven by nine inches) and will bear the names of the Apollo 16 astronauts, John W. Young, mission Commander; Thomas K. Mattingly II, Command Module Pilot; and Charles M. Duke, Jr., Lunar Module Pilot.

1972-01-01

20

Human Carotid Plaque Calcification and Vulnerability  

Microsoft Academic Search

Background: Inflammation is a key mechanism in human atherosclerotic plaque vulnerability and disruption. The objective was to determine the differential gene expression of pro- and anti-inflammatory factors in the fibrous cap and shoulder region of noncalcified and calcified carotid endarterectomy plaques. Methods: Thirty carotid endarterectomy plaques were classified as type Va (noncalcified, n = 15) and type Vb (calcified, n

Carl-Magnus Wahlgren; Wei Zheng; Wael Shaalan; Jun Tang; Hisham S. Bassiouny

2009-01-01

21

View of Commemorative Plaque for ASTP  

NASA Technical Reports Server (NTRS)

A close-up view of the Commemorative Plaque for the Apollo Soyuz Test Project (ASTP). Two plaques divided into four quarters each will be flown on the ASTP mission. A four-part plaque is completely assembled here. The American ASTP crew will carry the four U.S. quarter pieces aboard Apollo; and the Soviet ASTP crew will carry the four USSR quarter sections aboard Soyuz. The eight quarter pieces will be joined together to form two complete commemorative plaques after the two spacecraft rendezvous and dock in Earth orbit. One complete plaque then will be returned to Earth by the astronauts; the other complete plaque will be brought back by the cosmonauts. The plaque is written in both English and Russian.

1975-01-01

22

Plaque-Based Competitive Hybridization  

Microsoft Academic Search

The authors have developed a simple, cost-saving experimental design, plaque-based competitive hybridization (PBCH), for genome-wide identification of genes differentially expressed in different tissues. PBCH offers advantages in comparison with other methods used in comparative genomics by combining the principles of differential hybridization with the subtractive hybridization. PBCH is particularly advantageous when libraries with few differences are to be analyzed. The

Zoltán Villányi; István Gyurján; Viktor Stéger; László Orosz

2008-01-01

23

ACTIVATION OF T LYMPHOCYTES IN ATHEROSCLEROTIC PLAQUES  

PubMed Central

Objective To decipher the immunological mechanisms of plaque maturation and rupture, it is necessary to analyze the phenotypes and distribution of individual lymphocytes which migrate to the plaques as well as their activation at different stages of plaque formation. Methods and Results We developed a protocol to isolate plaque-residing immune cells and analyze their status using polychromatic flow cytometry. We found that the composition and phenotype of T lymphocytes in the plaques differs from that in blood. CD4 and, in particular, CD8+ T cells in plaques are highly activated; the fraction of CD8 T cells co-expressing CD25 and HLA-DR in plaques was 10 times larger than in blood. Conclusions The first flow-cytoanalysis of individual T cells in atherosclerotic plaques indicates that plaques represent a separate immunological compartment from blood with lymphocytes characterized by a high level of T cells activation, which is compatible with the presence of antigen(s) that trigger infiltration activation of these cells. The ability to isolate and characterize these cells may lead to the identification of such antigens. PMID:21960562

Grivel, Jean-Charles; Ivanova, Oxana; Pinegina, Natalia; Blank, Paul S.; Shpektor, Alexander; Margolis, Leonid B.; Vasilieva, Elena

2011-01-01

24

Biomechanical structural stresses of atherosclerotic plaques.  

PubMed

Atherosclerotic plaques may rupture without warning, causing fatal clinical events such as myocardial infarction and stroke. Degree of stenosis, which is the current criterion for assessment of atherosclerotic disease severity, has been observed to have poor correlation with plaque vulnerability. Under physiological conditions, plaque undertakes mechanical loadings due to blood pressure and flow. From the material view point, rupture possibly occurs when the extra loading exceeds the material strength of the plaque. Therefore, morphological and mechanical features should be considered in an integrated way for a more accurate assessment of plaque vulnerability and for identification of the at-risk patient. Biomechanical stress analysis is a technique that allows such comprehensive assessment. This article focuses on the mechanical stresses in the plaque structure, which are believed to be of greater magnitude than the associated wall shear stress and are thought to be more closely associated with plaque rupture. We discuss the basic mechanics that govern plaque behavior, the material properties of atherosclerotic tissues and the studies investigating the association between high biomechanical stresses and plaque rupture. Parameter studies investigating the effect of morphologic factors on the critical biomechanical stresses and limitations of current simulation models are also reviewed. PMID:20936933

Sadat, Umar; Teng, Zhongzhao; Gillard, Jonathan H

2010-10-01

25

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

26

Amyloid plaques in PSAPP mice bind less metal than plaques in human Alzheimer's disease  

Microsoft Academic Search

Amyloid beta (A?) 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

Andreana C. Leskovjan; Antonio Lanzirotti; Lisa M. Miller

2009-01-01

27

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

28

Detection of Atherosclerotic Coronary Plaques by Fluorescence Lifetime Imaging Angioscopy  

E-print Network

Vulnerable plaque is a clinically silent condition of atherosclerotic plaque that leaves a large number of patients at risk of a coronary event. A method to detect vulnerable atherosclerotic plaque would greatly enhance the ability of clinicians...

Thomas, Patrick A.

2010-10-12

29

Noninvasive imaging of atheromatous carotid plaques  

Microsoft Academic Search

Atherothrombosis is a systemic disease of the arterial wall that affects the carotid, coronary, and peripheral vascular beds, and the aorta. This condition is associated with complications such as stroke, myocardial infarction, and peripheral vascular disease, which usually result from unstable atheromatous plaques. The study of atheromatous plaques can provide useful information about the natural history and progression of the

Zhi-Yong Li; Martin J Graves; Tjun Y Tang; Jonathan H Gillard; Umar Sadat

2009-01-01

30

MagnetresonanztomographischeBildgebung der atherosklerotischen Plaque  

Microsoft Academic Search

Zusammenfassung. Mit zunehmender räumlicher und zeitlicher Auflösung hat sich die Magnetresonanztomographie (MRT) im Verlauf der letzten Jahre zu einem viel versprechenden Verfahren zur Bildgebung atherosklerotischer Plaques entwickelt. Die MRT erlaubt neben der Detektion, Volumenbestimmung und Verlaufsbeurteilung atherosklerotischer Plaques auch die Charakterisierung verschiedener Plaquekomponenten, wie Fettkern („lipid core“), fibröse Kappe („fibrous cap“), Calcium und Thrombus. Zur Verbesserung der räumlichen Auflösung erweisen

Stefan G. Ruehm

2003-01-01

31

Maladies gingivales induites par la plaque  

Microsoft Academic Search

Dental plaque-induced gingival diseases are infectious diseases. They reflect the local inflammatory and host-specific immune responses to the dental bacterial biofilm. According to the new classification, they include those gingivitis associated with dental plaque only, and the gingival diseases that are modified by general factors. The diagnosis of gingivitis is based on gingival changes in colour, consistency and texture, without

F. Boschin; H. Boutigny; E. Delcourt-Debruyne

2004-01-01

32

Intravascular probe for detection of vulnerable plaque  

Microsoft Academic Search

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

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

2001-01-01

33

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

34

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

35

AdipositasErhöhte Mortalität durch arteriosklerotische Folgekrankheiten und Karzinome  

Microsoft Academic Search

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

A. Wirth

1997-01-01

36

Plaque-based competitive hybridization.  

PubMed

The authors have developed a simple, cost-saving experimental design, plaque-based competitive hybridization (PBCH), for genome-wide identification of genes differentially expressed in different tissues. PBCH offers advantages in comparison with other methods used in comparative genomics by combining the principles of differential hybridization with the subtractive hybridization. PBCH is particularly advantageous when libraries with few differences are to be analyzed. The authors demonstrate the use of PBCH by identifying 3 genes, up-regulated in the developing velvet antler of red deer (Cervus elaphus): ApoD, C011A2, and S100a1. The fidelity and sensitivity of PBCH is also shown: 1 specific clone among a library sample of 15,000 can be recognized. Possibilities for further utilizations are discussed. PMID:18227228

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

2008-01-01

37

Comprehensive plaque assessment by coronary CT angiography.  

PubMed

Most acute coronary syndromes are caused by sudden luminal thrombosis due to atherosclerotic plaque rupture or erosion. Preventing such an event seems to be the only effective strategy to reduce mortality and morbidity of coronary heart disease. Coronary lesions prone to rupture have a distinct morphology compared with stable plaques, and provide a unique opportunity for noninvasive imaging to identify vulnerable plaques before they lead to clinical events. The submillimeter spatial resolution and excellent image quality of modern computed tomography (CT) scanners allow coronary atherosclerotic lesions to be detected, characterized, and quantified. Large plaque volume, low CT attenuation, napkin-ring sign, positive remodelling, and spotty calcification are all associated with a high risk of acute cardiovascular events in patients. Computation fluid dynamics allow the calculation of lesion-specific endothelial shear stress and fractional flow reserve, which add functional information to plaque assessment using CT. The combination of morphologic and functional characteristics of coronary plaques might enable noninvasive detection of vulnerable plaques in the future. PMID:24755916

Maurovich-Horvat, Pál; Ferencik, Maros; Voros, Szilard; Merkely, Béla; Hoffmann, Udo

2014-07-01

38

Fibrillar Amyloid Plaque Formation Precedes Microglial Activation  

PubMed Central

In Alzheimer’s disease (AD), hallmark ?-amyloid deposits are characterized by the presence of activated microglia around them. Despite an extensive characterization of the relation of amyloid plaques with microglia, little is known about the initiation of this interaction. In this study, the detailed investigation of very small plaques in brain slices in AD transgenic mice of the line APP-PS1(dE9) revealed different levels of microglia recruitment. Analysing plaques with a diameter of up to 10 ?m we find that only the half are associated with clear morphologically activated microglia. Utilizing in vivo imaging of new appearing amyloid plaques in double-transgenic APP-PS1(dE9)xCX3CR1+/- mice further characterized the dynamic of morphological microglia activation. We observed no correlation of morphological microglia activation and plaque volume or plaque lifetime. Taken together, our results demonstrate a very prominent variation in size as well as in lifetime of new plaques relative to the state of microglia reaction. These observations might question the existing view that amyloid deposits by themselves are sufficient to attract and activate microglia in vivo. PMID:25799372

Steinbach, Sonja; Blazquez-Llorca, Lidia; Herms, Jochen

2015-01-01

39

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

40

Assessment of vulnerable coronary plaque by intravascular elasticity imaging  

Microsoft Academic Search

Plaque rupture is regarded as one of the main causes of acute coronary syndromes. To prevent plaque rupture and guide a pharmacological treatment, it is important to image the weak (fragile) part of atherosclerotic plaque. Our preliminary experiments revealed the feasibility of a strain image using IVUS (intravascular ultrasound) to discriminate between different types of plaque. For the purpose of

Tsuyoshi Shiina; Naotaka Nitta; Hiroyuki Endo; Masakazu Yamagishi

2004-01-01

41

Atherosclerotic plaque rupture in symptomatic carotid artery stenosis  

Microsoft Academic Search

Purpose: Plaque rupture is often the precipitating event in acute coronary syndromes. We hypothesized that a similar process occurs in stenotic carotid plaques in association with ischemic neurologic symptoms. Our purpose was to examine several morphologic features of stenotic carotid plaques and to determine which characteristics are more commonly associated with plaques obtained from patients with symptomatic carotid artery disease

Sandra Carr; Andrew Farb; William H. Pearce; Renu Virmani; James S. T. Yao

1996-01-01

42

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 ...

43

Historical Plaque at Marshall Space Flight Center  

NASA Technical Reports Server (NTRS)

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

2000-01-01

44

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

45

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 Saturn V Space Vehicle's induction into the National Register of Historic Places by the United States Department of the Interior.

2000-01-01

46

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

47

Plaque on Spirit Honors Columbia Astronauts  

NASA Technical Reports Server (NTRS)

A plaque commemorating the astronauts who died in the tragic accident of the Space Shuttle Columbia is mounted on the back of the Mars Exploration Rover Spirit's high-gain antenna. The plaque was designed by Mars Exploration Rover engineers. The astronauts are also honored by the new name of the rover landing site, the Columbia Memorial Station. This image was taken on Mars by Spirit's navigation camera.

2004-01-01

48

The pathology of parietal pleural plaques  

Microsoft Academic Search

The incidence, morbid anatomy, histology, and relationship of hyaline pleural plaques to exposure to asbestos has been studied.Plaques were found in 12·3% of 334 hospital necropsies (in an urban population in Glasgow, 41 cases). In 85·3% (35 cases) asbestos bodies were found in the lungs. There is evidence of a dose-response relationship between the number of asbestos bodies found in

G. Hefin Roberts

1971-01-01

49

Oral biofilm models for mechanical plaque removal  

Microsoft Academic Search

In vitro plaque removal studies require biofilm models that resemble in vivo dental plaque. Here, we compare contact and non-contact\\u000a removal of single and dual-species biofilms as well as of biofilms grown from human whole saliva in vitro using different\\u000a biofilm models. Bacteria were adhered to a salivary pellicle for 2 h or grown after adhesion for 16 h, after which, their

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

2010-01-01

50

Improved treatment planning for COMS eye plaques  

SciTech Connect

Purpose: A recent reanalysis of the Collaborative Ocular Melanoma Study (COMS) medium tumor trial concluded that incorporating factors to account for anisotropy, line source approximation, the gold plaque, and attenuation in the Silastic seed carrier into the dose calculations resulted in a significant and consistent reduction of calculated doses to structures of interest within the eye. The authors concluded that future eye plaque dosimetry should be 'performed using the most up-to-date parameters available.' The reason these factors are important is attributable to the low energy {sup 125}I radiation (approximately 28 keV) that is primarily absorbed by the photoelectric process. Photoelectric absorption is quite dependent on the atomic composition of the absorbing material. Being 40% silicon by weight, the effective atomic number of Silastic is significantly greater than that of water. Although the AAPM TG43 brachytherapy formalism inherently addresses the issues of source anisotropy and geometry, its parameter that accounts for scatter and attenuation, the radial dose function g(r), assumes that the source is immersed in infinite homogeneous water. In this work, factors are proposed for {sup 125}I that correct for attenuation in the Silastic carrier and scatter deficits resulting from the gold plaque and nearby air. The implications of using {sup 103}Pd seeds in COMS plaques are also discussed. Methods and materials: An existing TG43-based ophthalmic plaque planning system was modified to incorporate additional scatter and attenuation correction factors that better account for the path length of primary radiation in the Silastic seed carrier and the distance between the dose calculation point and the eye-air interface. Results: Compared with homogeneous water, the dose-modifying effects of the Silastic and gold are greatest near the plaque surface and immediately adjacent to the plaque, while being least near the center of the eye. The calculated dose distribution surrounding a single {sup 125}I seed centered in a COMS 20 mm plaque was found to be consistent with previously published examples that used thermoluminescent dosimetry measurements and Monte Carlo methods. For fully loaded 12 and 20 mm plaques, calculated dose to critical ocular structures ranged from 16%-50% less than would have been reported using the standard COMS dose calculation protocol. Conclusions: Treatment planning for COMS eye plaques that accurately accounts for the presence of the gold, Silastic and extraocular air is both possible and practical.

Astrahan, Melvin A. [Department of Radiation Oncology, University of Southern California Norris Cancer Hospital, Los Angeles, CA (United States)]. E-mail: astrahan@usc.edu

2005-03-15

51

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

Microsoft Academic Search

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

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

2010-01-01

52

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

53

Functional expression of dental plaque microbiota  

PubMed Central

Dental caries remains a significant public health problem and is considered pandemic worldwide. The prediction of dental caries based on profiling of microbial species involved in disease and equally important, the identification of species conferring dental health has proven more difficult than anticipated due to high interpersonal and geographical variability of dental plaque microbiota. We have used RNA-Seq to perform global gene expression analysis of dental plaque microbiota derived from 19 twin pairs that were either concordant (caries-active or caries-free) or discordant for dental caries. The transcription profiling allowed us to define a functional core microbiota consisting of nearly 60 species. Similarities in gene expression patterns allowed a preliminary assessment of the relative contribution of human genetics, environmental factors and caries phenotype on the microbiota's transcriptome. Correlation analysis of transcription allowed the identification of numerous functional networks, suggesting that inter-personal environmental variables may co-select for groups of genera and species. Analysis of functional role categories allowed the identification of dominant functions expressed by dental plaque biofilm communities, that highlight the biochemical priorities of dental plaque microbes to metabolize diverse sugars and cope with the acid and oxidative stress resulting from sugar fermentation. The wealth of data generated by deep sequencing of expressed transcripts enables a greatly expanded perspective concerning the functional expression of dental plaque microbiota. PMID:25177549

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

2014-01-01

54

Localized pleural plaques and lung cancer  

SciTech Connect

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

Partanen, T.; Nurminen, M.; Zitting, A.; Koskinen, H.; Wiikeri, M.; Ahlman, K. (Department of Epidemiology and Biostatistics, Institute of Occupational Health, Helsinki (Finland))

1992-01-01

55

Infliximab for the treatment of plaque psoriasis  

PubMed Central

Infliximab is a monoclonal antibody that targets tumor necrosis factor-? (TNF?). It is used in the treatment of a number of inflammatory disorders including severe plaque psoriasis. TNF? is thought to have a major role in psoriasis by promoting an inflammatory infiltrate into the skin and inducing keratinocyte proliferation and preventing keratinocyte apoptosis, which directly contributes to the characteristic plaque skin lesions. Based on four randomized, placebo-controlled, double-blind clinical trials and nine open-label uncontrolled trials of the use of infliximab in plaque psoriasis, it was found that infliximab is a highly efficacious, rapid, sustainable, and relatively safe therapy. Yet as with any biologic, caution is recommended in its use as infusion reactions, lupus-like syndromes, infections, malignancies including lymphomas, as well as other rare events have been reported. PMID:19707434

Gall, Jennifer S; Kalb, Robert E

2008-01-01

56

Statistical segmentation of carotid plaque neovascularization  

NASA Astrophysics Data System (ADS)

In several studies, intraplaque neovascularization (IPN) has been linked with plaque vulnerability. The recent development of contrast enhanced ultrasound enables IPN detection, but an accurate quantification of IPN is a big challenge due to noise, motion, subtle contrast response, blooming of contrast and artifacts. We present an algorithm that automatically estimates the location and amount of contrast within the plaque over time. Plaque pixels are initially labeled through an iterative expectation-maximization (EM) algorithm. The used algorithm avoids several drawbacks of standard EM. It is capable of selecting the best number of components in an unsupervised way, based on a minimum message length criterion. Next, neighborhood information using a 5×5 kernel and spatiotemporal behavior are combined with the known characteristics of contrast spots in order to group components, identify artifacts and finalize the classification. Image sequences are divided into 3-seconds subgroups. A pixel is relabeled as an artifact if it is labeled as contrast for more than 1.5 seconds in at least two subgroups. For 10 plaques, automated segmentation results were validated with manual segmentation of contrast in 10 frames per clip. Average Dice index and area ratio were 0.73+/-0.1 (mean+/-SD) and 98.5+/-29.6 (%) respectively. Next, 45 atherosclerotic plaques were analyzed. Time integrated IPN surface area was calculated. Average area of IPN was 3.73+/-3.51 mm2. Average area of 45 plaques was 11.6+/-8.6 mm2. This method based on EM contrast segmentation provides a new way of IPN quantification.

Akkus, Zeynettin; Bosch, Johan G.; Sánchez-Ferrero, Gonzalo V.; Carvalho, Diego D. B.; Renaud, Guillaume; van den Oord, Stijn C. H.; ten Kate, Gerrit L.; Schinkel, Arend F. L.; de Jong, Nico; van der Steen, Antonius F. W.

2013-03-01

57

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

58

Plaque fluoride and mutans streptococci in plaque and saliva before and after discontinuation of water fluoridation.  

PubMed

Our aim was to compare plaque fluoride and the level of mutans streptococci in saliva and plaque before and 1 and 2 years after discontinuation of water fluoridation in Kuopio, Finland. For comparison, a low-fluoride community was included in the study. Pooled plaque and saliva were collected from a random sample of 12-year-olds in both communities (n = 139). Enumeration of mutans streptococci in plaque was made on MSB agar and the level of salivary mutans streptococci was measured using the Strip mutans method. Fluoride was analyzed using a fluoride specific electrode. Caries, gingival status, fluoride varnish applications and self-reported oral health habits were recorded at baseline. Before discontinuation of fluoridation, the level of mutans streptococci in saliva was significantly lower in the fluoridated than in the non-fluoridated community. The difference in plaque mutans streptococci was not statistically significant. After discontinuation of water fluoridation, there was a significant shift towards elevated values of salivary mutans streptococci in the fluoridated community, but the level of mutans streptococci in plaque remained at the baseline level. There was no significant difference between the communities in the fluoride content of plaque either before or after discontinuation of fluoridation. From the background factors, only caries scores (higher in the non-fluoridated community) and oral hygiene (better in the non-fluoridated community) were significantly different between the communities. PMID:8930582

Seppä, L; Hausen, H; Kärkkäinen, S

1996-08-01

59

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

Microsoft Academic Search

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

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

2005-01-01

60

DIFFERENTIAL EFFECT OF TETRAZOLIUM UPON BACTERIOPHAGE PLAQUE ASSAY TITERS  

EPA Science Inventory

This study examined whether the practice of incorporating either tetrazolium red ortetrazolium violet dye into plaque assay medium deleteriously influences plaque assay titers. epresentative members of six different virus families were studied: ystoviridae (06), Leviviridae (MS2)...

61

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

62

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 a National Historic Landmark. The site was designated as such in 1985 by the National Park Service of the United States Department of the Interior.

2000-01-01

63

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 Saturn V Launch Vehicle as a National Historic Landmark. The site was designated as such in 1984 by the National Park Service of the United States Department of the Interior.

2000-01-01

64

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 designation of the Propulsion and Structural Test Facility as a National Historic Landmark by the National Park Service of the United States Interior. The site was designated as a landmark in 1985.

2000-01-01

65

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 Saturn V Dynamic Test Stand as a National Historic Landmark. The site was designated as such in 1985 by the National Park Service of the United States Department of the Interior.

2000-01-01

66

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 Neutral Buoyancy Space Simulator as a National Historic Landmark. The site was designated as such in 1986 by the National Park Service of the United States Department of the Interior.

2000-01-01

67

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

68

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

69

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

70

Influence of microcalcifications on vulnerable plaque mechanics using FSI modeling  

Microsoft Academic Search

Sudden heart attacks remain one of the primary causes of premature death in the developed world. Asymptomatic vulnerable plaques that rupture are believed to prompt such fatal heart attacks and strokes. The role of microcalcifications in the vulnerable plaque rupture mechanics is still debated. Recent studies suggest the microcalcifications increase the plaque vulnerability. In this manuscript we present a numerical

Danny Bluestein; Yared Alemu; Idit Avrahami; Morteza Gharib; Kris Dumont; John J. Ricotta; Shmuel Einav

71

Influence of microcalcifications on vulnerable plaque mechanics using FSI modeling  

Microsoft Academic Search

Sudden heart attacks remain one of the primary causes of premature death in the developed world. Asymptomatic vulnerable plaques that rupture are believed to prompt such fatal heart attacks and strokes. The role of microcalcifications in the vulnerable plaque rupture mechanics is still debated. Recent studies suggest the microcalcifications increase the plaque vulnerability. In this manuscript we present a numerical

Danny Bluestein; Yared Alemu; Idit Avrahami; Morteza Gharib; Kris Dumont; John J. Ricotta; Shmuel Einav

2008-01-01

72

Intravascular Modalities for Detection of Vulnerable Plaque Current Status  

Microsoft Academic Search

Progress in the diagnosis, treatment, and prevention of atherosclerotic coronary artery disease is dependent on a greater understanding of the mechanisms of coronary plaque progression. Autopsy studies have characterized a subgroup of high-risk, or vulnerable, plaques that result in acute coronary syndromes or sudden cardiac death. These angiographically modest plaques share certain pathologic characteristics: a thin, fibrous cap, lipid-rich core,

Briain D. MacNeill; Harry C. Lowe; Masamichi Takano; Valentin Fuster; Ik-Kyung Jang

73

Intravascular photoacoustic imaging to detect and differentiate atherosclerotic plaques  

Microsoft Academic Search

Atherosclerosis is a systemic disease characterized by the development of a plaque leading to several acute coronary syndromes. Imaging of plaque structure and composition is important in diagnosing the disease and further guiding coronary interventions. Currently, there is no clinical imaging technique capable of providing comprehensive morphological and functional information of the plaques. Several emerging techniques including palpography and thermography

S. Sethuraman; S. Aglyamov; J. Amirian; R. Smalling; S. Emelianov

2005-01-01

74

View of plaque Apollo 11 astronauts left on moon  

NASA Technical Reports Server (NTRS)

Closeup view of the plaque which the Apollo 11 astronauts left on the moon in commemoration of the historic lunar landing mission. The plaque was attached to the ladder on the landing gear strut on the descent stage of the Apollo 11 Lunar Module. The plaque was covered with a thin sheet of stainless steel during flight.

1969-01-01

75

Cosmonaut Leonov and Astronaut Stafford display ASTP commemorative plaque  

NASA Technical Reports Server (NTRS)

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

1975-01-01

76

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

77

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

78

Videocapillaroscopic Findings in the Microcirculation of the Psoriatic Plaque  

Microsoft Academic Search

Background: Videocapillaroscopy (VCP) is a method to study the morphology and dynamics of microcirculation, but information about capillaroscopic features of the psoriatic plaque is limited. Objective: To investigate the distribution, morphology and density of capillaries in lesional and perilesional skin of the psoriatic plaque. Methods: VCP of a well-delimited plaque of the trunk, arms or legs in 15 consecutive patients

Rossella De Angelis; Leonardo Bugatti; Patrizia Del Medico; Massimiliano Nicolini; Giorgio Filosa

2002-01-01

79

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

80

Plaque pHandMicroflora ofDental Plaque onSoundandCarious RootSurfaces  

Microsoft Academic Search

Giventhehypothesis that root caries istheresult of acidformation byacidogenic micro-organisms, thepresent study wasperformed torelate sucrose-induced pHresponse ofdentalplaqueon rootsurfaces tothemicrobial composition oftheoverlying plaque. Seventeen caries-active elderly Chinese withpoororal hygiene andwithbothsound andcarious rootsurfaces wereexamined. Plaque pH was measured before anduptoonehourafter acontrolled sucrose mouthrinse. Plaquesamples formicrobiologic analyses werecollected from2soundand2or3carious pH- measurement sites ineachsubject. Theprevalence ofthe following micro-organisms wasassessed as% oftotal viable countsonBrucella agar: Prevotella

A. Aamdal-Scheiel; W.-M. Luan; G. Dahlen

81

Simple Method for Plating Escherichia coli Bacteriophages Forming Very Small Plaques or No Plaques under Standard Conditions  

Microsoft Academic Search

The use of low concentrations (optimally 2.5 to 3.5 g\\/ml, depending on top agar thickness) of ampicillin in the bottom agar of the plate allows for formation of highly visible plaques of bacteriophages which otherwise form extremely small plaques or no plaques on Escherichia coli lawns. Using this method, we were able to obtain plaques of newly isolated bacteriophages, propagated

J. M. Los; Piotr Golec; G. Wegrzyn; A. Wegrzyn; M. Los

2008-01-01

82

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

83

Cap buckling as a potential mechanism of atherosclerotic plaque vulnerability.  

PubMed

Plaque rupture in atherosclerosis is the primary cause of potentially deadly coronary events, yet about 40% of ruptures occur away from the plaque cap shoulders and cannot be fully explained with the current biomechanical theories. Here, cap buckling is considered as a potential destabilizing factor which increases the propensity of the atherosclerotic plaque to rupture and which may also explain plaque failure away from the cap shoulders. To investigate this phenomenon, quasistatic 2D finite element simulations are performed, considering the salient geometrical and nonlinear material properties of diverse atherosclerotic plaques over the range of physiological loads. The numerical results indicate that buckling may displace the location of the peak von Mises stresses in the deflected caps. Plaque buckling, together with its deleterious effects is further observed experimentally in plaque caps using a physical model of deformable mock coronary arteries with fibroatheroma. Moreover, an analytical approach combining quasistatic equilibrium equations with the Navier-Bresse formulas is used to demonstrate the buckling potential of a simplified arched slender cap under intraluminal pressure and supported by foundations. This analysis shows that plaque caps - calcified, fibrotic or cellular - may buckle in specific undulated shapes once submitted to critical loads. Finally, a preliminary analysis of intravascular ultrasonography recordings of patients with atherosclerotic coronary arteries corroborates the numerical, experimental and theoretical findings and shows that various plaque caps buckle in vivo. By displacing the sites of high stresses in the plaque cap, buckling may explain the atherosclerotic plaque cap rupture at various locations, including cap shoulders. PMID:24491969

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

2014-04-01

84

Elemental analysis of soft plaque and calcified plaque deposits from human coronary arteries and aorta.  

PubMed

Twenty-five samples of soft plaque and calcified plaque deposits from human hearts or aorta were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The determined elements were Ca, P, Na, K, Mg, Zn, Cu, Ba, Pb, Fe, Al, Si, and S. Results showed that the concentration of all elements in the soft plaque was at the micromolar level. In the calcified deposits, the concentrations of Ca and P were at least an order of magnitude higher than the soft plaque, but the other elements were at the same order of magnitude. In the calcified plaque the molar ratios of Ca/P suggested that a significant portion existed as hydroxyapatite Ca10(PO4)6(OH)3. However, their absolute concentrations indicated that this compound was not a major component of the plaque although it may play a major role in determining the crystal structure of the deposit. In some samples the Ca/P ratio was too high to conform to hydroxyapatite. In others it was too low. This indicated that both the calcium and phosphorus existed in other chemical forms which varied from sample to sample. In the soft tissue the P level was high indicating it existed primarily in chemical forms other than hydroxyapatite. The presence of homocysteine is often associated with heart disease. However, the low levels of sulfur indicate that although it may be present, it is not a major component of the plaque, but may nevertheless play an important role in its formation. PMID:15244331

Murungi, J I; Thiam, S; Tracy, R E; Robinson, J W; Warner, I M

2004-01-01

85

Enucleation versus plaque irradiation for choroidal melanoma  

SciTech Connect

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

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

1988-07-01

86

Choroidal melanoma: I-125 plaque therapy  

SciTech Connect

An iodine-125 eye plaque was used to treat 58 patients with choroidal melanoma. Patients were followed up for a mean of 48.7 months. Fifty patients had medium-sized lesions (height between 3.1 and 8.0 mm and base diameter less than 16.0 mm), and six patients had large lesions. There were 24 lesions less than 3.0 mm from the optic nerve. The average radiation dose to the apex of the tumor was 8,468 cGy (dose rate, 71 cGy per hour). Initial local disease control was achieved in 50 patients (86.2%). One patient with local treatment failure received another plaque treatment, which controlled disease, so the total disease control rate was 87.9%. Only eight patients died of their disease. Complications were similar to those with other treatment methods, but none of the patients in this study developed optic nerve atrophy.

Bosworth, J.L.; Packer, S.; Rotman, M.; Ho, T.; Finger, P.T.

1988-10-01

87

Annular plaques on the back and flanks.  

PubMed

An 86-year-old African American woman sought care for an asymptomatic rash on her back and flanks that she'd had for 14 months. Physical examination of her trunk revealed 3 to 6 cm annular/arcuate plaques with central clearing. The lesions also had a delicate trailing scale behind a slightly raised erythematous rim. The combination of a ring-shaped rash on the patient's torso and a foot infection led us to the diagnosis. PMID:25574507

Bankhead, Sarah; Jackson, Jeremy; Brodell, Robert

2015-01-01

88

Intravascular Thermography for Assessing Vulnerable Plaques  

Microsoft Academic Search

Atherosclerosis and its cardiovascular complications remain the leading cause of death in developed countries. Current knowledge\\u000a of coronary artery disease progression has significantly evolved and the interest has been focused on the development of new\\u000a imaging techniques for the early detection of vulnerable lesions. Intracoronary thermography is a method that detects local\\u000a plaque inflammation. Clinical studies with intracoronary thermography have

Konstantinos Toutouzas; Maria Drakopoulou; Andreas Synetos; Christodoulos Stefanadis

2010-01-01

89

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

90

Choroidal melanoma: I-125 plaque therapy  

Microsoft Academic Search

An iodine-125 eye plaque was used to treat 58 patients with choroidal melanoma. Patients were followed up for a mean of 48.7 months. Fifty patients had medium-sized lesions (height between 3.1 and 8.0 mm and base diameter less than 16.0 mm), and six patients had large lesions. There were 24 lesions less than 3.0 mm from the optic nerve. The

J. L. Bosworth; S. Packer; M. Rotman; T. Ho; P. T. Finger

1988-01-01

91

Amyloid plaques in transmissible spongiform encephalopathies (prion diseases).  

PubMed

Amyloid plaques are encountered in all cases of kuru and Gerstmann-Straussler-Scheinker disease (GSS) and in some 10-15% of sporadic Creutzfeldt-Jakob disease (sCJD) cases. In variant Creutzfeldt-Jakob (vCJD) the particular type of plaque known as "florid" or "daisy" plaque exists in 100% of cases. By electron microscopy several types of amyloid plaque were delineated, corresponding to those seen by PrP immunohistochemistry. Unicentric "kuru" plaques consisted of stellate arrangements (stars or cores) of amyloid bundles emanating from a dense interwoven centre. A proportion of kuru plaques formed very dense stars, reminiscent of sea urchins in shape. Others presented a looser pattern. Amyloid stars were enveloped by astrocytic processes. High-power electron micrographs revealed that amyloid bundles were concealed within grooves of obscure cellular origin. Interestingly, basement membranes lined with electron-dense material were observed at the periphery of many amyloid plaques of GSS. Dystrophic neurites were seen only rarely. Microglial cells formed a significant part of the amyloid plaques. Occasionally clusters composed of several kuru plaques were found. These were intermediate forms to multi-centric plaques, which consisted of several merging stellate cores. Smaller amyloid deposits surrounded larger cores. In contrast to the kuru plaques, associated with a limited number of dystrophic neurites (DN), numerous such structures were seen at the periphery. The DN were filled with abnormal organelles such as electron-dense bodies, multi-vesicular bodies and multilamellar bodies and thus were indistinguishable from those seen in scrapie and CJD or Alzheimer's disease, except that they did not contain paired helical filaments (PHF). Instead, piled neurofilaments were often detected in the centres of DN. Similar DN were observed but these were not associated with any plaques. The last and, by the same token, the rarest type of plaque was the purely neuritic plaque. These consisted of large areas filled with DN of different sizes and shapes (sometimes bizarre) but not amyloid bundles. Analogously to the kuru and multi-centric plaques, astrocytic processes were observed at the periphery. By means of light microscopy and semi-thin (1 microm) sections discrete PrP-immunopositive plaques were observed (data not shown), in the subependymal region but not in the deep brain neuroparenchyma, in both 263K and 22C-H scrapie-infected hamster brains. These plaques were not discernible by routine haematoxylin and eosin staining. Ultrastructurally, plaques were recognised as areas of low electron density containing haphazardly-oriented fibrils which, when immunogold techniques were applied, were heavily decorated with PrP-conjugated gold particles. PMID:16903146

Liberski, Pawe? P

2004-01-01

92

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

93

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

94

Computer Simulations of Atherosclerotic Plaque Growth in Coronary Arteries  

PubMed Central

A three dimensional mathematical model with a linear plaque growth function was developed to investigate the geometrical adaptation of atherosclerotic plaques in coronary arteries and study the influences of flow wall shear stress (WSS), blood viscosity and the inlet flow rate on the growth of atherosclerotic plaques using computational plaque growth simulations. The simulation results indicated that the plaque wall thickness at the neck of the stenosis increased at a decreasing rate in the atherosclerosis progression. The simulation results also showed a strong dependence of the plaque wall thickness increase on the blood viscosity and the inlet flow rate. The progression rate in a coronary artery was lower with a higher inlet velocity flow rate and higher with a smaller value of the blood viscosity. PMID:21141673

Liu, Biyue; Tang, Dalin

2011-01-01

95

Plaque Size Heterogeneity: a Genetic Trait of Lymphocytic Choriomeningitis Virus  

PubMed Central

All of the ten strains of lymphocytic choriomeningitis virus assayed on BHK 21/13S cells showed various degrees of plaque size heterogeneity. The amount of virus released from these plaques was usually very small because of rapid photodynamic inactivation by neutral red. When virus from large and small plaques of a specific strain was plated, the same distribution of plaque size was obtained from each clone. Although it was shown that surface virus could possibly be randomly distributed at the time of addition of neutral red overlays, no virus could be isolated from nonplaque areas. Two different strains of virus (CA1371 and WE) with markedly different plaque size ranges were separated by plaque excision from plates infected with a mixture of both viruses. Images PMID:4195608

Pulkkinen, A. J.; Pfau, C. J.

1970-01-01

96

Siglec receptors and hiding plaques in Alzheimer's disease  

Microsoft Academic Search

Alzheimer's disease (AD) is a progressive neurodegenerative disease. One hallmark of this disease is the continuous increase\\u000a in the numbers and size of aggregating amyloid plaques. The accumulation of extracellular plaques is an immunologically interesting\\u000a phenomenon since microglial cells, brain-specific macrophages, should be able to cleanse the aggregating material from the\\u000a human brain. Immunotherapy targeting ?-amyloid peptides in plaques with

Antero Salminen; Kai Kaarniranta

2009-01-01

97

Correlations between Numbers of Microf lora in Plaque and Saliva  

Microsoft Academic Search

An epidemiologic investigation to reliably identify caries-susceptible subjects by microbiological and chemical assessment of plaque and saliva is currently in progress. As part of that study, the numerical relationships of mutans streptococci, lactobacilli and total viable microflora in plaque and saliva among 12- to 15-year-old children in a fluoridated community were determined. Paraffin-stimulated whole saliva and pooled dental plaque were

Sheila A. Mundorff; Arthur D. Eisenberg; Dennis H. Leverett; Mark A. Espeland; Howard M. Proskin

1990-01-01

98

Stability Analysis of a Model of Atherosclerotic Plaque Growth  

PubMed Central

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

Reddy, Sushruth; Seshaiyer, Padmanabhan

2015-01-01

99

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

100

Expression of NPP1 is regulated during atheromatous plaque calcification  

PubMed Central

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

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

2011-01-01

101

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

102

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.

103

Plaque which Apollo 11 astronauts will leave on the moon  

NASA Technical Reports Server (NTRS)

Closeup view of the plaque which the Apollo 11 astronauts will leave behind on the moon is commemoration of the historic event. The plaque is made of stainless steel measuring nine by seven and five-eighths inches, and one-sixteenth inch thick. The plaque will be attached to the ladder on the landing gear strut on the descent stage of the Apollo 11 Lunar Module. Covering the plaque during flight will be a thin sheet of stainless steel which will be removed on the lunar surface.

1969-01-01

104

Retinal atheromatous plaques: their recognition by elevating the intraocular pressure.  

PubMed Central

Recognition and further study of existing retinal atheromatous plaques in the central retinal artery may be enhanced by pressure on the globe. This simple maneuver should be used when patients with transient ischemic attacks (cerebral or ocular) are examined with or without atheromatous disease of the carotid artery. Previously unseen or suspected plaques may be brought into view. Plaques already visible may appear larger or vary greatly in both color and texture giving indication of their composition. The recognition of these atheromatous plaques is important in the diagnosis of atheromatous disease. Images FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 1 D PMID:867624

Hedges, T R

1976-01-01

105

Retinal atheromatous plaques: their recognition by elevating the intraocular pressure.  

PubMed

Recognition and further study of existing retinal atheromatous plaques in the central retinal artery may be enhanced by pressure on the globe. This simple maneuver should be used when patients with transient ischemic attacks (cerebral or ocular) are examined with or without atheromatous disease of the carotid artery. Previously unseen or suspected plaques may be brought into view. Plaques already visible may appear larger or vary greatly in both color and texture giving indication of their composition. The recognition of these atheromatous plaques is important in the diagnosis of atheromatous disease. PMID:867624

Hedges, T R

1976-01-01

106

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

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

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

107

Stress analysis of carotid plaque rupture based on in vivo high resolution MRI  

Microsoft Academic Search

Atheromatous carotid plaque rupture is responsible for the majority of ischaemic strokes in the developed world. Plaque rupture has been associated with plaque morphology, plaque components’ properties, inflammation and local stress concentration. High resolution multi-spectral magnetic resonance imaging (MRI) has allowed the plaque components to be visualized in vivo. This study combined the recent advances in finite element analysis (FEA)

Zhi-Yong Li; Simon Howarth; Rikin A. Trivedi; Jean M. U-King-Im; Martin J. Graves; Andrew Brown; Liqun Wang; Jonathan H. Gillard

2006-01-01

108

Fibrous Pleural Plaques Detected at Autopsy  

PubMed Central

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

TÜRKMEN, Nursel; EREN, Bülent; GÜNDO?MU?, Ümit Naci

2014-01-01

109

[Plaque surgery for Peyronie's disease: heterologous grafts].  

PubMed

Surgical treatment of Induratio Penis Plastica includes conservative procedures (phalloplasty), substitutive procedures (prosthesis) and combined procedures (phalloplasty plus prosthesis). Our policy for conservative treatment is based on radical removal of the plaque and replacement with biological patches. During a 15 year experience we employed lyophilized dura mater, autologous dermal graft, preputial skin, cadaveric dermal graft (AlloDerm), venous graft and porcine SIS (Small Intestine Submucosa) graft. Our experience confirms the superiority of venous grafts, but preliminary results with SIS grafts are encouraging. PMID:12868152

Paradiso, Matteo; Sedigh, Omid; Milan, Gian Luca

2003-06-01

110

76 FR 66307 - Scientific Information Request on Phototherapy for Treatment of Chronic Plaque Psoriasis  

Federal Register 2010, 2011, 2012, 2013, 2014

...Phototherapy for Treatment of Chronic Plaque Psoriasis AGENCY: Agency for Healthcare Research...devices for treatment of chronic plaque psoriasis. Scientific information is being solicited...Phototherapy for Treatment of Chronic Plaque Psoriasis, which is currently being...

2011-10-26

111

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

112

Complement factor C5a induces atherosclerotic plaque disruptions  

PubMed Central

Complement factor C5a and its receptor C5aR are expressed in vulnerable atherosclerotic plaques; however, a causal relation between C5a and plaque rupture has not been established yet. Accelerated atherosclerosis was induced by placing vein grafts in male apoE?/? mice. After 24 days, when advanced plaques had developed, C5a or PBS was applied locally at the lesion site in a pluronic gel. Three days later mice were killed to examine the acute effect of C5a on late stage atherosclerosis. A significant increase in C5aR in the plaque was detectable in mice treated with C5a. Lesion size and plaque morphology did not differ between treatment groups, but interestingly, local treatment with C5a resulted in a striking increase in the amount of plaque disruptions with concomitant intraplaque haemorrhage. To identify the potential underlying mechanisms, smooth muscle cells and endothelial cells were treated in vitro with C5a. Both cell types revealed a marked increase in apoptosis after stimulation with C5a, which may contribute to lesion instability in vivo. Indeed, apoptosis within the plaque was seen to be significantly increased after C5a treatment. We here demonstrate a causal role for C5a in atherosclerotic plaque disruptions, probably by inducing apoptosis. Therefore, intervention in complement factor C5a signalling may be a promising target in the prevention of acute atherosclerotic complications. PMID:25124749

Wezel, Anouk; de Vries, Margreet R; Lagraauw, H Maxime; Foks, Amanda C; Kuiper, Johan; Quax, Paul HA; Bot, Ilze

2014-01-01

113

Plaque the Apollo 14 crew will leave on the Moon  

NASA Technical Reports Server (NTRS)

A close-up view of the plaque which the Apollo 14 crew will leave behind on the Moon during their lunar landing mission. The seven by nine-inch stainless steel plaque will be attached to the ladder on the landing gear strut on the Lunar Module's descent stage.

1971-01-01

114

Apollo Soyuz Test Project Commemorative plaque in orbit  

NASA Technical Reports Server (NTRS)

The Apollo-Soyuz Test Project (ASTP) Commemorative Plaque is assembled in the Soviet Soyuz Orbital Module during the joint U.S.-U.S.S.R. Apollo-Soyuz Test Project docking in Earth orbit mission. The plaque is written both in English and Russian.

1975-01-01

115

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

116

Effect of polyol gums on dental plaque in orthodontic patients  

Microsoft Academic Search

Sixty 11- to 15-year-old children wearing fixed orthodontic appliances were given chewing gums containing polyol for daily use after meals and snacks, to study whether the chewing of gums that contained slowly fermentable polyols (xylitol and sorbitol) affects the amount of dental plaque and the number of mutans streptococci present in plaque and saliva. The 60 subjects were randomly divided

K. P. Isotupa; S. Gunn; C.-Y. Chen; D. Lopatin; K. K. Mäkinen

1995-01-01

117

Automated coronary CT angiography plaque-lumen segmentation  

NASA Astrophysics Data System (ADS)

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

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

2009-02-01

118

Caries-related plaque microcosm biofilms developed in microplates.  

PubMed

In vivo dental plaque biofilms consist of complex communities of oral bacteria that are a challenge to replicate in vitro. The aim of this investigation was to establish human dental plaque microcosms in microplates to reflect conditions that are relevant to dental caries. Microcosm plaque biofilms were initiated from the saliva of two different donors, grown for up to 10 days in 24-welled microplates on Thermanox coverslips in various types of artificial saliva with and without sucrose, which were replaced daily. Microbiota composition of 40 species associated with oral health and dental caries was monitored in the plaques using Checkerboard DNA-DNA hybridization analysis. pH was measured as an indicator of cariogenic potential. The composition of the saliva inocula was different, and yielded plaque microcosms with different composition and growth responses to sucrose. Artificial saliva type and presence of sucrose, and the resulting growth and pH conditions, modified the growth of individual species and hence the ecological profile of the microplate plaques during development. Complex population shifts were observed during development, and older plaques comprised predominantly facultative anaerobic species. Sucrose supplementation limited the decline of Streptococci over time but did not increase the abundance of mutans Streptococci. Sucrose at 0.15% increased levels of caries-associated species including Lactobacillus fermentum, Lactobacillus acidophilus and Actinomyces gerensceriae; these were further increased with sucrose at 0.5%, in addition to Actinomyces israelii, Rothia dentocariosa and Capnocytophaga gingivalis. The microplate plaques demonstrated complex community dynamics that appeared to reflect the maturation of natural plaques, and sucrose induced a cariogenic plaque composition and pH. PMID:17311629

Filoche, S K; Soma, K J; Sissons, C H

2007-04-01

119

Effect of in situ plaque mineral supplementation on the state of saturation of plaque fluid during sugar-induced acidogenesis.  

PubMed

Dental plaque fluid is normally supersaturated with respect to enamel mineral but this may change to a state of undersaturation when plaque pH falls following sugar exposure, placing the adjacent enamel at risk of caries. We have determined the saturation status of the fluid in both resting and fermenting plaque following mineral supplementation. Eleven subjects abstained from oral hygiene and rinsed their mouth 3 times/d for 3 d with a placebo solution or with test solutions designed to enrich plaque with hydroxyapatite or fluorhydroxyapatite. On the morning of day 4, plaque samples were collected before and after exposure to 10% sucrose. Compared to the placebo, use of the test rinses resulted in significantly higher concentrations of Ca, P and F in plaque residue. In plaque fluid, higher post-sucrose Ca2+ free concentrations and saturation levels with respect to enamel mineral and fluorapatite were found after use of the hydroxyapatite rinse compared to the placebo, effects that probably resulted from the release of cell-bound Ca2+ as well as from the dissolution of apatite. Thus, some evidence was obtained that the test mouthrinses can counteract the fall in saturation level found when plaque is exposed briefly to sucrose. Potential long-term benefits of the test mouthrinses deserve further study. PMID:10467940

Pearce, E I; Margolis, H C; Kent, R L

1999-08-01

120

Apollo 11 5th Annivesary Commemoration Plaque  

NASA Technical Reports Server (NTRS)

On July 3, 1974 NASA commemorated the 5th anniversary of the Apollo 11, first lunar landing mission, at the Kennedy Space Center (KSC). Launch Pad 39, from which astronauts Neil Armstrong, Edwin Aldrin, and Michael Collins first embarked on their historic journey to the Moon, was dedicated as a national landmark. Apollo 11 was launched at 9:32 am on July 16, 1969 and made the first successful lunar landing July 20th. During the 45 minute ceremony, the three Apollo 11 astronauts unveiled this plaque which was placed at the launch site. Other participating dignitaries included Dr. James Fletcher and Dr. George H. Low, NASA Administrator and Deputy Administrator respectively; Florida Governor Rubin Askew; Senator frank E. Moss; Congressman Olin E. Teague, and Kurt Debus, KSC Director. Apollo 11 launched from the Kennedy Space Center, Florida via a Saturn V launch which was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun.

1974-01-01

121

Hydrogen sulfide production from subgingival plaque samples.  

PubMed

Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3 < 7 mm) and 35% had severe periodontal breakdown (CAL > 7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket. PMID:25280920

Basic, A; Dahlén, G

2014-09-30

122

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

123

Human oral, gut, and plaque microbiota in patients with atherosclerosis  

PubMed Central

Periodontal disease has been associated with atherosclerosis, suggesting that bacteria from the oral cavity may contribute to the development of atherosclerosis and cardiovascular disease. Furthermore, the gut microbiota may affect obesity, which is associated with atherosclerosis. Using qPCR, we show that bacterial DNA was present in the atherosclerotic plaque and that the amount of DNA correlated with the amount of leukocytes in the atherosclerotic plaque. To investigate the microbial composition of atherosclerotic plaques and test the hypothesis that the oral or gut microbiota may contribute to atherosclerosis in humans, we used 454 pyrosequencing of 16S rRNA genes to survey the bacterial diversity of atherosclerotic plaque, oral, and gut samples of 15 patients with atherosclerosis, and oral and gut samples of healthy controls. We identified Chryseomonas in all atherosclerotic plaque samples, and Veillonella and Streptococcus in the majority. Interestingly, the combined abundances of Veillonella and Streptococcus in atherosclerotic plaques correlated with their abundance in the oral cavity. Moreover, several additional bacterial phylotypes were common to the atherosclerotic plaque and oral or gut samples within the same individual. Interestingly, several bacterial taxa in the oral cavity and the gut correlated with plasma cholesterol levels. Taken together, our findings suggest that bacteria from the oral cavity, and perhaps even the gut, may correlate with disease markers of atherosclerosis. PMID:20937873

Koren, Omry; Spor, Aymé; Felin, Jenny; Fåk, Frida; Stombaugh, Jesse; Tremaroli, Valentina; Behre, Carl Johan; Knight, Rob; Fagerberg, Björn; Ley, Ruth E.; Bäckhed, Fredrik

2011-01-01

124

Palladium-103 versus iodine-125 for ophthalmic plaque radiotherapy  

SciTech Connect

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 scleral surface, four were located along the central axis of the plaque: the 1 mm point (the inner sclera), the 6 mm point, the tumors apex, and the opposite eye wall. They also evaluated the fovea, optic nerve, and the lens because they were considered to be critical structures. These studies demonstrated that the lower energy photons generated by Pd-103 seeds (average 21 KeV) in ophthalmic plaques were more rapidly absorbed in tissue than photons generated by I-125 (average 28 KeV). Therefore, during ophthalmic plaque radiotherapy, Pd-103 photons were found to be more rapidly absorbed within the tumor and less likely to reach most normal ocular structures. On average, the use of Pd-103 decreased the dose to the fovea by 5.7%, to the optic nerve by 8.4%, to the lens by 26%, and to the opposite eye wall by 38.4%. Pd-103 ophthalmic plaque brachytherapy resulted in slightly more irradiation of the tumor and less radiation to most normal ocular structures. 36 refs., 1 fig., 3 tabs.

Finger, P.T. (Cornell Univ. Medical College, New York, NY (United States) New York Eye and Ear Infirmary, New York, NY (United States)); Lu, D.; Buffa, A.; DeBlasio, D.S.; Bosworth, J.L. (Cornell Univ. Medical College, New York, NY (United States))

1993-11-15

125

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

126

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

2015-03-01

127

Replica of Plaque Left on Moon by Apollo 17 Astronauts  

NASA Technical Reports Server (NTRS)

This image is a photographic replica of the plaque that the Apollo 17 astronauts left on the Moon at the Taurus-Littrow landing site. Apollo 17 was the final lunar landing mission in NASA's Apollo program. The commemorative plaque was unveiled at the close of the third extravehicular activity (EVA-3). The plaque was made of stainless steel measuring nine by seven and five-eighths inches, and one-sixteenth inch thick. It was attached to the ladder on the landing gear strut on the descent stage of Apollo 17 Lunar Module 'Challenger.'

1972-01-01

128

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

129

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

130

Ultrasonographic and histologic characteristics of symptom-free and symptomatic carotid plaque  

Microsoft Academic Search

The purpose of the study was to determine the reliability of ultrasonography in assessing plaque pathology and to relate it to clinical symptoms. Ten symptom-free patients and 26 with symptomatic carotid plaques with a stenosis >70%, as detected by arteriography, were assessed by duplex. The findings were compared with the clinical presentation and plaque pathology. Pathological specimens of the plaque

D. G. Kardoulas; A. N. Katsamouris; P. Th. Gallis; Th. Ph. Philippides; N. K. Anagnostakos; D. S. Gorgoyannis; N. C. Gourtsoyannis

1996-01-01

131

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

PubMed

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

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

2014-04-01

132

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

133

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

134

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

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

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

135

156. 1932 UNITED DAUGHTERS OF CONFEDERACY, DISTRICT CHAPTERS MEMORIAL PLAQUE ...  

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

156. 1932 UNITED DAUGHTERS OF CONFEDERACY, DISTRICT CHAPTERS MEMORIAL PLAQUE AND REPLACEMENT RED OAK MEMORIAL PLANTING. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

136

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

137

Clathrin and Cx43 gap junction plaque endoexocytosis  

SciTech Connect

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

Nickel, Beth M.; DeFranco, B. Hewa; Gay, Vernon L. [Department of Cell Biology and Physiology, University of Pittsburgh, School of Medicine, 324 South Biomedical Science Tower, Pittsburgh, PA 15261 (United States); Murray, Sandra A. [Department of Cell Biology and Physiology, University of Pittsburgh, School of Medicine, 324 South Biomedical Science Tower, Pittsburgh, PA 15261 (United States)], E-mail: smurray@pitt.edu

2008-10-03

138

Clathrin and Cx43 gap junction plaque endoexocytosis.  

PubMed

In earlier transmission electron microscopic studies, we have described pentilaminar gap junctional membrane invaginations and annular gap junction vesicles coated with short, electron-dense bristles. The similarity between these electron-dense bristles and the material surrounding clathrin-coated pits led us to suggest that the dense bristles associated with gap junction structures might be clathrin. To confirm that clathrin is indeed associated with annular gap junction vesicles and gap junction plaques, quantum dot immuno-electron microscopic techniques were used. We report here that clathrin associates with both connexin 43 (Cx43) gap junction plaques and pentilaminar gap junction vesicles. An important finding was the preferential localization of clathrin to the cytoplasmic surface of the annular or of the gap junction plaque membrane of one of the two contacting cells. This is consistent with the possibility that the direction of gap junction plaque internalization into one of two contacting cells is regulated by clathrin. PMID:18675253

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

2008-10-01

139

Radiolabeled bioactive benzoheterocycles for imaging ?-amyloid plaques in Alzheimer's disease.  

PubMed

Alzheimer's disease (AD) is a debilitating neurodegenerative dementia that involves substantial neuronal loss. Extracellular deposition of neurotoxic ?-amyloid (A?) plaques in the brain has been recognized as the central histological characteristic of AD. In the past decade, precise detection of the A? plaques at preclinical AD with positron emission tomography (PET) or single photon emission computed tomography (SPECT) has achieved continued development. A big category of A? imaging agents was benzoheterocycles which derived from Thioflavin-T (ThT), a traditional amyloid binding dye. This review summarizes the past and current status of radioactive benzoheterocycles designed to selectively bind to A? plaques. Separate sections discuss the chemical synthesis, in vitro and in vivo investigations of radiolabeled benzothiazole, benzoxazole, benzofuran, benzothiophene, indole, imidazopyridine and quinoxaline analogs to act as PET/SPECT candidates for imaging A? plaques. PMID:25305715

Yang, Yanping; Cui, Mengchao

2014-11-24

140

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

141

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

142

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

143

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

144

Plaque-like cutaneous mucinosis: case report and literature review.  

PubMed

Midline mucinosis was observed in a 14-year-old man, which was confined to the midline of the back and appeared as asymptomatic, nonindurated, hyperpigmented plaques. Skin biopsies showed prominent interstitial mucinosis with perivascular lymphocytic infiltration. A literature review of plaque-like mucinosis revealed 14 previous cases with this distinct presentation that may overlap with reticular erythematous mucinosis and connective tissue disease. Midline mucinosis has been previously reported in prepubertal children but is rare. PMID:22617136

Wriston, Cooper C; Rubin, Adam I; Martin, Linda K; Kossard, Steven; Murrell, Dedee F

2012-06-01

145

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

Microsoft Academic Search

Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections.\\u000a However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To\\u000a evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique\\u000a and to compare it with the effect of NaCl and

Nicole Birgit Arweiler; Thorsten Mathias Auschill; Anton Sculean

146

An interactive treatment planning system for ophthalmic plaque radiotherapy  

SciTech Connect

Brachytherapy using removable episcleral plaques containing sealed radioisotope sources is being studied as an alternative to enucleation in the treatment of choroidal melanoma and other tumors of the eye. Encouraging early results have been reported, but late complications which lead to loss of vision continue to be a problem. A randomized national study, the Collaborative Ocular Melanoma Study (COMS) is currently in progress to evaluate the procedure. The COMS specified isotope is 125I. Precise dosimetric calculations near the plaque may correlate strongly with complications and could also be used to optimize isotope loading patterns in the plaques. A microcomputer based treatment planning system has been developed for ophthalmic plaque brachytherapy. The program incorporates an interactive, 3-dimensional, solid-surface, color-graphic interface. The program currently supports 125I and 192Ir seeds which are treated as anisotropic line sources. Collimation effects related to plaque structure are accounted for, permitting detailed study of shielding effectiveness near the lip of a plaque. A dose distribution matrix may be calculated in any subregion of a transverse, sagittal, or coronal planar cross section of the eye, in any plane transecting the plaque and crossing the eye diametrically, or on a spherical surface within or surrounding the eye. Spherical surfaces may be displayed as 3-dimensional perspective projections or as funduscopic diagrams. Isodose contours are interpolated from the dose matrix. A pointer is also available to explicitly calculate and display dose at any location on the dosimetry surface. An interactive editing capability allows new plaque designs to be rapidly added to the system.

Astrahan, M.A.; Luxton, G.; Jozsef, G.; Kampp, T.D.; Liggett, P.E.; Sapozink, M.D.; Petrovich, Z. (Univ. of Southern California School of Medicine, Los Angeles (USA))

1990-03-01

147

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

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

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

148

Methotrexate toxicity presenting as cutaneous ulcerations on psoriatic plaques.  

PubMed

Methotrexate (MTX) is an effective but potentially toxic treatment for psoriasis. We describe a patient who administered 20?mg daily of MTX for 5?d and presented with ulcerated and necrotic lesions on the psoriatic plaques, mouth erosions and hair loss. However, his psoriatic plaques and ulcerations totally healed rapidly within two weeks and no recurrence has been observed for the 6 months of follow up. PMID:23537374

Koçak, Asl?han Yonca; Koçak, O?uzhan; Aslan, Figen; Tekta?, Mustafa

2013-10-01

149

Effect of rinse with calcium enriched milk on plaque fluid.  

PubMed

Previous research has shown that rinsing the mouth with milk significantly diminished the pH in dental plaque fluid; however, the degree of saturation with respect to the dental enamel (DS) was not significantly decreased because of an increase in the calcium ion concentration in plaque fluid. The aim of this study was to investigate the cariostatic effect of adding calcium to milk on the DS value of the plaque fluid after rinsing. Plaque samples were collected from 8 Japanese male dental students. Prior to plaque collection, all subjects refrained from practicing oral hygiene for 48 hr and fasted overnight. Supragingival plaque samples were collected from one side of the mouth of each subject, and then collected from the other side, following a 30-second rinse with 15 mL of calcium-enriched milk, which was prepared by adding calcium carbonate to ordinary milk, and a 10-minute waiting period. The samples were cleared by centrifugation, and the plaque fluid was analyzed for inorganic ions and pH, using an ion chromatograph and pH microelectrode, respectively. The calcium ion concentration of the milk was 6.4 mM, which was about 36% higher than that of ordinary milk. The pH decreased significantly (p<5%) from 6.4 to 6.1 following the rinse with calcium enriched milk, as tested by the paired t-test. The decrease in pH might have caused a reduction of the DS value; however, it was compensated for by a significant (p<0.5%) increase in the calcium ion concentration of plaque fluid. PMID:12160258

Tanaka, M; Matsunaga, K; Kadoma, Y

1999-09-01

150

Lung asbestos bodies and pleural plaques at autopsy  

Microsoft Academic Search

Summary  Examination for lung asbestos bodies and pleural plaques was made in 996 consecutive unselected autopsies in Torino. The prevalence\\u000a of asbestos bodies was 12.4% and that of pleural plaques 19.1%. Both findings were found with significantly greater frequency\\u000a in men, and in the age group above 50 years. In addition, their occurrence increased with age up to 70 years, then

Alberto Andrion; Alessandro Colombo; Franco Mollo

1982-01-01

151

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

152

An Ultrasonographic Risk Score For Detecting Symptomatic Carotid Atherosclerotic Plaques.  

PubMed

This paper proposes a risk score computed from ultrasound data that correlates to plaque activity. It has the twofold purpose of detecting symptomatic plaques and estimating the likelihood of the asymptomatic lesion to become symptomatic. The proposed ultrasonographic activity index (UAI) relies on the plaque active profile which is a combination of the most discriminate ultrasound parameter associated with symptoms. These features are extracted by the automatic algorithm and also by the physician from the ultrasound images and from some transformations on it, such as monogenic decomposition which is a novelty in this clinical problem. This information is used to compute a risk score from the conditional probabilities of either symptomatic or asymptomatic groups. Symptom detection performance is evaluated on a transversal dataset of 146 plaques, where UAI obtained 83:5% accuracy, 84:1% sensitivity and 83:7% specificity. Performance is also assessed on a longitudinal study of 112 plaques, where UAI shows a significant improvement over the gold standard degree of stenosis, demonstrating higher power at predicting which asymptomatic plaques developed symptoms in an average follow-up of 10 months. Results suggest that this score could have a positive impact on early stroke prevention and treatment planning. PMID:25252286

Afonso, David; Seabra, Jose; Pedro, Luis; E Fernandes, Jose Fernandes; Sanches, Joao

2014-09-19

153

Medical image retrieval based on plaque appearance and image registration.  

PubMed

The increasing amount of medical images produced and stored daily in hospitals needs a datrabase management system that organizes them in a meaningful way, without the necessity of time-consuming textual annotations for each image. One of the basic ways to organize medical images in taxonomies consists of clustering them depending of plaque appearance (for example, intravascular ultrasound images). Although lately, there has been a lot of research in the field of Content-Based Image Retrieval systems, mostly these systems are designed for dealing a wide range of images but not medical images. Medical image retrieval by content is still an emerging field, and few works are presented in spite of the obvious applications and the complexity of the images demanding research studies. In this chapter, we overview the work on medical image retrieval and present a general framework of medical image retrieval based on plaque appearance. We stress on two basic features of medical image retrieval based on plaque appearance: plaque medical images contain complex information requiring not only local and global descriptors but also context determined by image features and their spatial relations. Additionally, given that most objects in medical images usually have high intra- and inter-patient shape variance, retrieval based on plaque should be invariant to a family of transformations predetermined by the application domain. To illustrate the medical image retrieval based on plaque appearance, we consider a specific image modality: intravascular ultrasound images and present extensive results on the retrieval performance. PMID:15923736

Amores, Jaume; Radeva, Petia

2005-01-01

154

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

155

Clinical studies of plaque control agents: an overview.  

PubMed

Dental plaque is massed packed bacterial cells which accumulate on the supra- and subgingival surfaces of the teeth as well as on the oral mucosa. The microorganisms of plaque have been shown to be associated with both dental caries and periodontal disease. This overview of clinical studies of plaque control agents reviews the properties and effects of chemical compounds which have demonstrated a potential for the control of plaque microorganisms. The search for clinically effective antiplaque agents has been stimulated by findings in laboratory and animal studies of plaque dynamics. Based upon these in vitro and in vivo experiments, chemotherapeutic agents such as antibiotics, antiseptics, enzymes, detergents, bacteriosides, antimetabolites, and oxidizing agents have been evaluated against human plaque microorganisms using the ultimate biological model -- man. Continued study of chemotherapeutic agents should be encouraged because many of these drugs have been shown to be safe for human use and may require only the development of a delivery system to potentiate their concentration in a specific local site. Use of these chemotherapeutic agents, which can be self-administered, becomes an attractive way of providing the public with a cost-effective method of preventing caries and periodontal disease. PMID:117032

Lobene, R R

1979-12-01

156

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

PubMed

Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections. However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique and to compare it with the effect of NaCl and chlorhexidine (CHX), 18 subjects had to refrain from all mechanical and chemical hygiene measures for 24 h. A voluminous supragingival plaque sample was taken from the buccal surfaces of the lower molars and wiped on an objective slide. The sample was then divided into three equal parts and mounted with one of the three test or control preparations (a) NaCl, (b) taurolidine 2% and (c) CHX 0.2%. After a reaction time of 2 min, the test solutions were sucked of. Subsequently, the plaque biofilm was stained with fluorescence dye and vitality of the plaque flora was evaluated under the fluorescence microscope (VF%). Plaque samples treated with NaCl showed a mean VF of 82.42?±?6.04%. Taurolidine affected mean VF with 47.57?±?16.60% significantly (p?plaque biofilm which was, however, not as pronounced as that of CHX. PMID:21360105

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

2012-04-01

157

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

158

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

159

Acid production in dental plaque after exposure to probiotic bacteria  

PubMed Central

Background The increasing interest in probiotic lactobacilli in health maintenance has raised the question of potential risks. One possible side effect could be an increased acidogenicity in dental plaque. The aim of this study was to investigate the effect of probiotic lactobacilli on plaque lactic acid (LA) production in vitro and in vivo. Methods In the first part (A), suspensions of two lactobacilli strains (L. reuteri DSM 17938, L. plantarum 299v) were added to suspensions of supragingival dental plaque collected from healthy young adults (n=25). LA production after fermentation with either xylitol or fructose was analyzed. In the second part (B), subjects (n=18) were given lozenges with probiotic lactobacilli (L. reuteri DSM 17938 and ATCC PTA 5289) or placebo for two weeks in a double-blinded, randomized cross-over trial. The concentration of LA in supragingival plaque samples was determined at baseline and after 2 weeks. Salivary counts of mutans streptococci (MS) and lactobacilli were estimated with chair-side methods. Results Plaque suspensions with L. reuteri DSM 17938 produced significantly less LA compared with L. plantarum 299v or controls (p<0.05). Fructose gave higher LA concentrations than xylitol. In part B, there were no significant differences in LA production between baseline and follow up in any of the groups and no differences between test and placebo were displayed. The salivary MS counts were not significantly altered during the intervention but the lactobacilli counts increased significantly in the test group (p<0.05). Conclusion Lactic acid production in suspensions of plaque and probiotic lactobacilli was strain-dependant and the present study provides no evidence of an increase in plaque acidity by the supply of selected probiotic lactobacilli when challenged by fructose or xylitol. The study protocol was approved by The Danish National Committee on Biomedical Research Ethics (protocol no H-2-2010-112). Trial registration NCT01700712 PMID:23092239

2012-01-01

160

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

161

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

162

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

163

Quantitative Evaluation of Atherosclerotic Plaque Using Ultrasound Tissue Characterization.  

NASA Astrophysics Data System (ADS)

Evaluation of therapeutic methods directed toward interrupting and/or delaying atherogenesis is impeded by the lack of a reliable, non-invasive means for monitoring progression or regression of disease. The ability to characterize the predominant component of plaque may be very valuable in the study of this disease's natural history. The earlier the lesion, the more likely is lipid to be the predominant component. Progression of plaque is usually by way of overgrowth of fibrous tissues around the fatty pool. Calcification is usually a feature of the older or complicated lesion. To explore the feasibility of using ultrasound to characterize plaque we have conducted measurements of the acoustical properties of various atherosclerotic lesions found in freshly excised samples of human abdominal aorta. Our objective has been to determine whether or not the acoustical properties of plaque correlate with the type and/or chemical composition of plaque and, if so, to define a measurement scheme which could be done in-vivo and non-invasively. Our current data base consists of individual tissue samples from some 200 different aortas. Since each aorta yields between 10 to 30 tissue samples for study, we have data on some 4,468 different lesions or samples. Measurements of the acoustical properties of plaque were found to correlate well with the chemical composition of plaque. In short, measurements of impedance and attenuation seem sufficient to classify plaque as to type and to composition. Based on the in-vitro studies, the parameter of attenuation was selected as a means of classifying the plaque. For these measurements, an intravascular ultrasound scanner was modified according to our specifications. Signal processing algorithms were developed which would analyze the complex ultrasound waveforms and estimate tissue properties such as attenuation. Various methods were tried to estimate the attenuation from the pulse-echo backscattered signal. Best results were obtained by comparing averaged power spectra in small time windows at different depths for a series of A-lines. Comparisons between consequent averaged spectra at different depths provided the magnitude and frequency dependence of attenuation. Non-invasive characterization of the physical state of the tissue with quantitative ultrasound holds great promise for the extension of the diagnostic power of conventional B-mode imaging.

Yigiter, Ersin

164

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

165

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

166

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

167

Efficacy of Methotrexate in patients with plaque type psoriasis  

PubMed Central

Objective: To assess the efficacy of Methotrexate in patients with plaque type psoriasis. Methods: This descriptive study was conducted in the department of Dermatology, Civil Hospital Karachi from September 2009 to March 2010. Seventy three patients between 18 to 50 years of age suffering from plaque type psoriasis with PASI score of >10 were included in the study after taking the informed consent. Oral methotrexate in a dose of 7.5 mg/week was given for 8 weeks. The data collected included demographic profile (age and gender), duration of disease, site of involvement, size of plaque, severity of plaque measured by Psoriasis Area and Severity Index (PASI) score before starting the treatment and at the end of treatment. Efficacy was labeled with a PASI score of ?5 at the end of 8 weeks. Results: Out of 73 patients there were 45 (61.6%) males and 28 (38.4%) females. The mean ±SD age was 40.0±12.6 years. The mean baseline PASI score showed clear and comparable improvement from a mean ± SD PASI score of 14.8±4.2 to 4.9±4.3.Twenty nine (40%) patients had an almost complete remission during the 8 weeks of treatment. Partial remission was achieved in 44 (60%) patients. The clearance time for psoriasis ranged from 5-7 weeks (mean 6±0.89 weeks). Conclusion: Treatment with methotrexate for chronic plaque psoriasis brings satisfactory disease control and improved quality of life. PMID:25225524

Haider, Sabiqa; Wahid, Zarnaz; Najam-us-Saher; Riaz, Farzana

2014-01-01

168

Gamma mixture classifier for plaque detection in intravascular ultrasonic images.  

PubMed

Carotid and coronary vascular incidents are mostly caused by vulnerable plaques. Detection and characterization of vulnerable plaques are important for early disease diagnosis and treatment. For this purpose, the echomorphology and composition have been studied. Several distributions have been used to describe ultrasonic data depending on tissues, acquisition conditions, and equipment. Among them, the Rayleigh distribution is a one-parameter model used to describe the raw envelope RF ultrasound signal for its simplicity, whereas the Nakagami distribution (a generalization of the Rayleigh distribution) is the two-parameter model which is commonly accepted. However, it fails to describe B-mode images or Cartesian interpolated or subsampled RF images because linear filtering changes the statistics of the signal. In this work, a gamma mixture model (GMM) is proposed to describe the subsampled/interpolated RF images and it is shown that the parameters and coefficients of the mixture are useful descriptors of speckle pattern for different types of plaque tissues. This new model outperforms recently proposed probabilistic and textural methods with respect to plaque description and characterization of echogenic contents. Classification results provide an overall accuracy of 86.56% for four classes and 95.16% for three classes. These results evidence the classifier usefulness for plaque characterization. Additionally, the classifier provides probability maps according to each tissue type, which can be displayed for inspecting local tissue composition, or used for automatic filtering and segmentation. PMID:24402895

Vegas-Sánchez-Ferrero, Gonzalo; Seabra, José; Rodriguez-Leor, Oriol; Serrano-Vida, Angel; Aja-Fernández, Santiago; Palencia, César; Martín-Fernández, Marcos; Sanches, Joao

2014-01-01

169

Lymphoma with large-plaque parapsoriasis treated with PUVA.  

PubMed

We report on a 78-year-old Japanese woman with a 50-year history of large-plaque parapsoriasis that had evolved into cutaneous T-cell lymphoma. Her large-plaque parapsoriasis had been treated with psoralen plus ultraviolet A for 10 years. Subsequently an isolated nodule appeared on her right lower leg. Prior or concurrent patches or plaques were absent. Histology revealed a diffuse nonepidermotropic infiltrate of large lymphocytes in the dermis, which had enlarged nuclei and prominent nucleoli. A diagnosis of CD30- cutaneous large T-cell lymphoma was made. Following systemic chemotherapy, there was clinical improvement. No evidence of recurrence or systemic lymphoma has subsequently been found. PMID:16048755

Tamagawa, Risa; Katoh, Norito; Shimazaki, Chihiro; Okano, Akira; Yamada, Shinya; Ichihashi, Kaori; Masuda, Koji; Kishimoto, Saburo

2005-01-01

170

Method of making a light weight battery plaque  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

171

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

172

DETAIL OF PLAQUE COMMEMORATING THE JULY/ AUGUST 1958 VOYAGE OF ...  

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

DETAIL OF PLAQUE COMMEMORATING THE JULY/ AUGUST 1958 VOYAGE OF THE USS NAUTILUS (SSN-571) TO THE NORTH POLE. NOTE: THIS PLAQUE IS NOT LOCATED AT WHARFS S13-S19; IT IS AT THE SUBMARINE MEMORIAL PARK, ABOUT 1,000' SOUTH OF THE WHARFS. THE LOCATION AND ORIENTATION OF THIS PHOTO IS NOT SHOWN ON THE PHOTO KEY MAP - U.S. Naval Base, Pearl Harbor, Additional Piers and Quay Walls, S13 to S19, Northeast end of Magazine Loch, Pearl City, Honolulu County, HI

173

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

174

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

175

Ultrasound Used to Attack Alzheimer's-Linked Brain Plaque in Mice  

MedlinePLUS

... enable JavaScript. Ultrasound Used to Attack Alzheimer's-Linked Brain Plaque in Mice Treatment is preliminary, but may ... treatment might help eliminate plaque buildup in the brain that's associated with Alzheimer's disease. Scientists don't ...

176

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

Code of Federal Regulations, 2013 CFR

... Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5580 Oral rinse to reduce the adhesion of dental plaque. (a) Identification...

2013-04-01

177

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

Code of Federal Regulations, 2010 CFR

... Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5580 Oral rinse to reduce the adhesion of dental plaque. (a) Identification...

2010-04-01

178

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

Code of Federal Regulations, 2011 CFR

... Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5580 Oral rinse to reduce the adhesion of dental plaque. (a) Identification...

2011-04-01

179

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

Code of Federal Regulations, 2014 CFR

... Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5580 Oral rinse to reduce the adhesion of dental plaque. (a) Identification....

2014-04-01

180

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

Code of Federal Regulations, 2012 CFR

... Oral rinse to reduce the adhesion of dental plaque. 872.5580 Section 872...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5580 Oral rinse to reduce the adhesion of dental plaque. (a) Identification...

2012-04-01

181

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.

182

Biofilm structure and cell vitality in a laboratory model of subgingival plaque  

Microsoft Academic Search

The accumulation of dental plaque below the gingival margin (i.e. subgingival plaque) is responsible for the most prevalent microbe-induced diseases of humans — the periodontal diseases. Access to this plaque is difficult, making studies of its structure in vivo very difficult. We have, therefore, used a constant-depth film fermenter to grow microcosm subgingival dental plaques under conditions similar to those

C. K. Hope; M. Wilson

2006-01-01

183

3D MRI-Based Multicomponent FSI Models for Atherosclerotic Plaques  

Microsoft Academic Search

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

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

2004-01-01

184

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

PubMed Central

The general population is exposed to cadmium from food and smoking. Cadmium is a widely spread toxic pollutant that seems to be associated with cardiovascular diseases, although little is known if it contributes to the occurrence of atherosclerotic plaques and the process whereby plaques become vulnerable and are prone to rupture. We tested the hypotheses that cadmium exposure is associated not only with an increased subclinical burden of atherosclerotic plaques in different vascular territories and early signs of plaque vulnerability, but also with cadmium content and plaque-rupture in the clinical phase of the disease. Ultrasound technique was used to measure plaque prevalence and echogenicity in the carotid and femoral arteries in a population sample of women (n = 599) in whom blood cadmium was measured. In addition cadmium was measured in snap-frozen endarterectomies and whole blood obtained from patients who were referred to surgery because of symptomatic carotid plaques (n = 37). Sixteen endarterectomies were divided into three parts corresponding to different flow conditions and plaque vulnerability. In the population sample blood cadmium was associated with the number of vascular territories with plaques (p = 0.003 after adjustment for potential confounders). The cadmium concentrations in symptomatic plaques were 50-fold higher in plaque tissue than in blood. Cadmium levels in blood and plaque correlated, also after adjustment for smoking and other cardiovascular risk factors (p<0.001). Compared with the other parts of the plaque, the cadmium content was double as high in the part where plaque rupture usually occurs. In conclusion, the results show that cadmium exposure is associated with the burden of subclinical atherosclerosis in middle-aged women with different degrees of glucose tolerance, and that the content of cadmium in symptomatic plaques in patients is related to that in blood, but much higher, and preferentially located in the part of plaque where rupture often occurs. PMID:25816093

Sallsten, Gerd; Lundh, Thomas; Barregard, Lars

2015-01-01

185

Antiviral neutralizing antibody to Hantaan virus as determined by plaque reduction technique  

Microsoft Academic Search

Summary The 76–118 strain of Hantaan virus was titrated in E6 (Vero) cells by the plaque method using agarose overlay medium. Visible plaques, formed 10 days post-infection, were uniformly 2–3 mm in diameter. Dose-response experiments showed that a single infectious particle initiated the formation of a plaque. Infectivity titers by the plaque method were equivalent to those obtained by the

A. Takenaka; C. J. Gibbs; D. C. Gajdusek

1985-01-01

186

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

187

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

188

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

189

SEQUENTIAL INOCULATION AS AN ADJUNCT IN ENTERIC VIRUS PLAQUE ENUMERATION  

EPA Science Inventory

The potential utility of sequentially inoculating a virus sample onto two different cultures of similar dissimilar cell lines was evaluated in conjunction with IDU (5-iodo-2'-deoxyuridine) treatment of the cells as a potential adjunct in viral plaque formation assays. his evaluat...

190

152. 1932 MEMORIAL PLAQUE FROM THE NATIONAL COLONIAL DAMES OF ...  

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

152. 1932 MEMORIAL PLAQUE FROM THE NATIONAL COLONIAL DAMES OF AMERICA, DISTRICT CHAPTER, AND MEMORIAL PLANTING OF TWO SPECIMEN WILLOW OAKS AT FT. WASHINGTON OVERLOOK LOOKING SOUTHEAST. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

191

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

192

Plaque Formation in Agar by Single Antibody-Producing Cells  

Microsoft Academic Search

Distinct plaques, each of which is due to the release of hemolysin by a single antibody-forming cell, are revealed by complement after incubation, in an agar layer, of a mixture of sheep red cells and lymphoid cells from a rabbit immunized with sheep red cells.

Niels K. Jerne; Albert A. Nordin

1963-01-01

193

Bone mineral density of patients with chronic plaque psoriasis  

Microsoft Academic Search

Summary Reduced bone mineral density (BMD), the major risk factor for osteoporotic fracture, has been linked to palmoplantar pustular psoriasis, but no significant studies have examined BMD in chronic plaque psoriasis (CPP). In this study, in-patients with severe CPP had their BMD measured at the nondominant hip and lumbar spine using dual energy X-ray absorbtiometry. Ten male and 10 female

T. P. Millard; L. Antoniades; A. V. Evans; H. R. Smith; T. D. Spector; J. N. W. N. Barker

2001-01-01

194

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

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

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

195

Inadequate dietary magnesium intake increases atherosclerotic plaque development in rabbits  

E-print Network

Inadequate dietary magnesium intake increases atherosclerotic plaque development in rabbits at Urbana-Champaign, Urbana, IL 61801, USA b Division of Nutritional Sciences, Department of Food Science magnesium (Mg) intake and serum Mg levels to be inversely correlated with the development of atherosclerosis

Illinois at Urbana-Champaign, University of

196

Variogram methods for texture classification of atherosclerotic plaque ultrasound images  

NASA Astrophysics Data System (ADS)

Stroke is the third leading cause of death in the western world and the major cause of disability in adults. The type and stenosis of extracranial carotid artery disease is often responsible for ischemic strokes, transient ischemic attacks (TIAs) or amaurosis fugax (AF). The identification and grading of stenosis can be done using gray scale ultrasound scans. The appearance of B-scan pictures containing various granular structures makes the use of texture analysis techniques suitable for computer assisted tissue characterization purposes. The objective of this study is to investigate the usefulness of variogram analysis in the assessment of ultrasound plague morphology. The variogram estimates the variance of random fields, from arbitrary samples in space. We explore stationary random field models based on the variogram, which can be applied in ultrasound plaque imaging leading to a Computer Aided Diagnosis (CAD) system for the early detection of symptomatic atherosclerotic plaques. Non-parametric tests on the variogram coefficients show that the cofficients coming from symptomatic versus asymptomatic plaques come from distinct distributions. Furthermore, we show significant improvement in class separation, when a log point-transformation is applied to the images, prior to variogram estimation. Model fitting using least squares is explored for anisotropic variograms along specific directions. Comparative classification results, show that variogram coefficients can be used for the early detection of symptomatic cases, and also exhibit the largest class distances between symptomatic and asymptomatic plaque images, as compared to over 60 other texture features, used in the literature.

Jeromin, Oliver M.; Pattichis, Marios S.; Pattichis, Constantinos; Kyriacou, Efthyvoulos; Nicolaides, Andrew

2006-03-01

197

Development of plaque assays for adenoviruses 40 and 41  

Microsoft Academic Search

Enteric adenoviruses, important agents of infantile gastroenteritis, are difficult to culture with low titers and limited CPE. Consequently, few plaque assays have been reported and none are used routinely by investigators who may need reproducible quantitative assays for these viruses. CPE in A549 cells (an epithelial lung carcinoma cell line) was induced by isolates of human adenovirus (HAdV) serotypes 40

Theresa L. Cromeans; Xiaoyan Lu; Dean D. Erdman; Charles D. Humphrey; Vincent R. Hill

2008-01-01

198

Thoracic aortic plaques, transoesophageal echocardiography and coronary artery disease  

Microsoft Academic Search

Background: The purpose of this study was to assess whether the detection of atherosclerotic aortic plaques by transoesophageal echocardiogra- phy (TEE) could be used as a marker of coronary artery disease (CAD), relying on their number, cross-sectional surface, depth and localisation. Methods: The thoracic aortas of 102 consecu- tive patients (77 men, mean age 67 ± 12 years) undergoing elective

Lucka Sekoranja; Francesco Bianchi-Demicheli; Pedro T. Trindade; René Lerch

199

Erosion of psoriatic plaques: An early sign of methotrexate toxicity  

Microsoft Academic Search

Methotrexate is an effective but potentially toxic treatment for psoriasis. Well-known signs of methotrexate toxicity include bone marrow suppression and oral and gastrointestinal ulceration. Painful erosion of psoriatic plaques is a less common sign of methotrexate toxicity that may precede evidence of bone marrow suppression. We describe two patients in whom painful erosions of their psoriasis developed as the presenting

Hannah P. Pearce; Barbara Braunstein Wilson

1996-01-01

200

Juxtalumenal location of plaque necrosis and neoformation in symptomatic carotid stenosis  

Microsoft Academic Search

Purpose: The structural features that underlie carotid plaque disruption and symptoms are largely unknown. We have previously shown that the chemical composition and structural complexity of critical carotid stenoses are related to plaque size regardless of symptoms. To further determine whether the spatial distribution of individual plaque components in relation to the lumen corresponds to symptomatic outcome, we evaluated 99

Hisham S. Bassiouny; Yashuhiro Sakaguchi; Susanne A. Mikucki; James F. McKinsey; Giancarlo Piano; Bruce L. Gewertz; Seymour Glagov

1997-01-01

201

The laminar distribution of neuritic plaques in the fascia dentata of patients with Alzheimer's disease  

Microsoft Academic Search

Neuritic plaques are prominent in the fascia dentata of the hippocampus and are often linearly oriented in stratum moleculare. Since the afferents to this region are also organized in a laminar pattern, the present study focused on the relative number and laminar distribution of plaques in this region to shed light on the genesis of the neuritic plaques. Examination of

B. J. Crain; P. C. Burger

1988-01-01

202

[Imaging and differentiation of atherosclerotic plaque with magnetic resonance tomography].  

PubMed

Magnetic resonance (MR) imaging studies have allowed the imaging of an atheroma, its size, shape, and lipid contents. The aim of our study was to characterize atherosclerotic lesions using a 0.5 T magnet, to delineate plaque components, and to compare MR results with histology. Thirty necropsy specimens of human iliac arteries were studied. Magnetic resonance imaging studies were carried out on a 0.5 Tesla superconducting magnet using a 5 cm surface coil. The position for the coronal MR planes was oriented by an external marker. The matrix size was 256 x 256, 4 NEX, and the FOV was 45 mm. The pulse sequences used included SE 520/29 and SE 2200/28 and 90. Signal intensity (SI) of fibrous plaques increased significantly from 28.3 +/- 3.8 to 49.1 +/- 8.2 (p < or = 0.0001) and decreased at SE 2200/90 to 24.1 +/- 6.8 (p < or = 0.0001). However, lipid plaque components showed no significant change in SI between T1-weighted pulse-sequences (28.2 +/- 5.4) and T2-weighted pulse-sequences (25.5 +/- 5.9). Only at SE 2200/90 SI of lipid plaques decreased significantly (11.8 +/- 3.9, p < or = 0.0001). As compared to histology, MR has shown a high sensitivity and specificity in the detection of fibrous and lipid plaque components. In conclusions, our study demonstrated that MR is highly effective in the characterization of atherosclerotic lesions. PMID:9782595

Loewe, C; Oberhuber, G; Loewe, R; Frank, H

1998-08-01

203

An in vitro biofilm model of subgingival plaque  

PubMed Central

Introduction: Numerous biofilm models have been described for the study of bacteria associated with the supragingival plaque. However, there are fewer models available for the study of subgingival plaque. The purpose of this study was to develop and validate a model that closely mimicked the composition of the subgingival flora. Methods: The model was developed as follows: calcium hydroxyapatite disks were coated overnight with 10% sterile saliva, placed in flat-bottomed tissue culture plates containing trypticase-soy broth, directly inoculated with a small aliquot of dispersed subgingival plaque, incubated anaerobically, and transferred to fresh medium at 48-h intervals until climax (steady-state) biofilms were formed (?10 days). Results: The model, based on samples from eight periodontitis patients and eight healthy subjects, yielded a multi-species, heterogeneous biofilm, consisting of both gram-positive and gram-negative species, and comprising 15?20 cultivable species associated with the subgingival flora. The species present and their proportions were reflective of the initial cultivable subgingival flora. Comparisons of the initial plaque samples from healthy subjects and the mature biofilms showed 81% similarity in species and 70% similarity in the proportions present. Biofilms formed from samples obtained from periodontally diseased subjects were 69% similar in species and 57% similar in the proportions present. Conclusions: The biofilm model described here closely reproduces the composition of the cultivable subgingival plaque both in the species present and in their relative proportions. Differences existed between biofilms grown from diseased and non-diseased sites with the former being characterized by the presence of periodontal pathogens at microbially significant levels. PMID:17488440

Walker, C.; Sedlacek, M. J.

2007-01-01

204

Optical Coherence Tomography Analysis of Attenuated Plaques Detected by Intravascular Ultrasound in Patients with Acute Coronary Syndromes  

PubMed Central

Background. Recent intravascular ultrasound (IVUS) studies have demonstrated that hypoechoic plaque with deep ultrasound attenuation despite absence of bright calcium is common in acute coronary syndrome. Such “attenuated plaque” may be an IVUS characteristic of unstable lesion. Methods. We used optical coherence tomography (OCT) in 104 patients with unstable angina to compare lesion characteristics between IVUS-detected attenuated plaque and nonattenuated plaque. Results. IVUS-detected attenuated plaque was observed in 41 (39%) patients. OCT-detected lipidic plaque (88% versus 49%, P < 0.001), thin-cap fibroatheroma (48% versus 16%, P < 0.001), plaque rupture (44% versus 11%, P < 0.001), and intracoronary thrombus (54% versus 17%, P < 0.001) were more often seen in IVUS-detected attenuated plaques compared with nonattenuated plaques. Conclusions. IVUS-detected attenuated plaque has many characteristics of unstable coronary lesion. The presence of attended plaque might be an important marker of lesion instability. PMID:21941667

Kubo, Takashi; Matsuo, Yoshiki; Ino, Yasushi; Tanimoto, Takashi; Ishibashi, Kohei; Komukai, Kenichi; Kitabata, Hironori; Tanaka, Atsushi; Kimura, Keizo; Imanishi, Toshio; Akasaka, Takashi

2011-01-01

205

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

206

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

PubMed Central

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

Navaravong, Leenhapong; Steenson, Carol; Sigurdsson, Gardar

2014-01-01

207

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

208

Quantification of arterial plaque and lumen density with MDCT  

SciTech Connect

Purpose: This study aimed to derive a mathematical correction function in order to normalize the CT number measurements for small volume arterial plaque and small vessel mimicking objects, imaged with multidetector CT (MDCT). Methods: A commercially available calcium plaque phantom (QRM GmbH, Moehrendorf, Germany) and a custom built cardiovascular phantom were scanned with 320 and 64 MDCT scanners. The calcium hydroxyapatite plaque phantom contained objects 0.5-5.0 mm in diameter with known CT attenuation nominal values ranging 50-800 HU. The cardiovascular phantom contained vessel mimicking objects 1.0-5.0 mm in diameter with different contrast media. Both phantoms were scanned using clinical protocols for CT angiography and images were reconstructed with different filter kernels. The measured CT number (HU) and diameter of each object were analyzed on three clinical postprocessing workstations. From the resultant data, a mathematical formula was derived based on absorption function exp(-{mu}{sup *}d) to demonstrate the relation between measured CT numbers and object diameters. Results: The percentage reduction in measured CT number (HU) for the group of selected filter kernels, apparent during CT angiography, is dependent only on the object size (plaque or vessel diameter). The derived formula of the form 1-c{sup *}exp(-a{sup *}d{sup b}) showed reduction in CT number for objects between 0.5 and 5 mm in diameter, with asymptote reaching background noise for small objects with diameters nearing the CT in-plane resolution (0.35 mm). No reduction was observed for the objects with diameters equal or larger than 5 mm. Conclusions: A clear mathematical relationship exists between object diameter and reduction in measured CT number in HU. This function is independent of exposure parameters and inherent attenuation properties of the objects studied. Future developments include the incorporation of this mathematical model function into quantification software in order to automatically generate a true assessment of measured CT number (HU) corresponding to plaque physical density {rho} (g/cm{sup 3}). This is a significant development for the accurate, noninvasive classification of noncalcified arterial plaque.

Paul, Narinder S.; Blobel, Joerg; Kashani, Hany; Rice, Murray; Ursani, Ali [Department of Medical Imaging, Toronto General Hospital, Toronto, Ontario M5G 2N2 (Canada); CT Systems Division, Toshiba Medical Systems Europe BV, 2718 RP Zoetermeer (Netherlands); Department of Medical Imaging, Toronto General Hospital, Toronto, Ontario M5G 2N2 (Canada); Department of Medical Engineering, University Health Network, Toronto, Ontario M5G 2N2 (Canada)

2010-08-15

209

Development of plaque assays for adenoviruses 40 and 41.  

PubMed

Enteric adenoviruses, important agents of infantile gastroenteritis, are difficult to culture with low titers and limited CPE. Consequently, few plaque assays have been reported and none are used routinely by investigators who may need reproducible quantitative assays for these viruses. CPE in A549 cells (an epithelial lung carcinoma cell line) was induced by isolates of human adenovirus (HAdV) serotypes 40 or 41 that were obtained by prior limited passage in primary cynmolgous monkey kidney (pCMK), human embryonic kidney (HEK), and Graham 293 cells. CPE with HAdV 40 (Dugan strain) and HAdV 41 (Tak strain) inoculated in A549 cells was also observed. Monolayers of A549 cells were inoculated with a low multiplicity of infection (MOI) of the archived stock isolates and harvested at days 10-14 with full CPE. Subsequent passages were harvested in as few as 7 days with 100% CPE to prepare virus stocks for plaque assay. Large individual plaques under agarose overlay were picked prior to staining and clonal stocks prepared. Titers of final stock preparations after six to eight passages in A549 cells were in the range of 5 x 10(7)-1 x 10(8)PFU/ml, which provides adequate virus for quantitative recovery studies. The particle to infectivity (P:I) ratios of the early passages of virus stocks were in the range reported previously. The ratio of non-infectious to infectious particles decreased with successive passages of HAdVs 40 and 41 in A549 cells. The specificity of the assay was confirmed by neutralization of plaques with type-specific antisera. Furthermore, sequence analysis of the HAdVs 40 and 41 plaque forming stocks ruled out contamination with any other HAdVs. The plaque assay developed will be useful for evaluation of virus recovery methods from water, food or other environmental matrices, as well as determination of the efficacy of water treatment techniques for inactivation of these viruses. PMID:18440077

Cromeans, Theresa L; Lu, Xiaoyan; Erdman, Dean D; Humphrey, Charles D; Hill, Vincent R

2008-07-01

210

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

211

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

SciTech Connect

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

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

1990-04-01

212

Elastin and Collagen-Rich Human Carotid Plaques Have Increased Levels of the Cysteine Protease Inhibitor Cystatin C  

Microsoft Academic Search

Background: Cystatin C is a major inhibitor of the elastin- and collagen-degrading cysteine proteases and may therefore have an important role in preserving atherosclerotic plaque stability. In this study we analyzed the associations between human carotid plaque cystatin C expression and the plaque content of collagen and elastin. Methods: Thirty-one plaques were removed by endarterectomy and homogenized. Cystatin C levels

Isabel Gonçalves; Mikko P. S. Ares; Anna Moberg; Jonatan Moses; Fong To; Jonathan Montan; Luís M. Pedro; Nuno Dias; José Fernandes e Fernandes; Gunilla Nordin Fredrikson; Jan Nilsson; Stefan Jovinge; Eva Bengtsson

2008-01-01

213

Septic rupture of an atherosclerotic plaque of the ascending aorta  

PubMed Central

Infectious aortitis has become a rare disease thanks to the widespread use of antibiotics. We report the case of a patient who, 15 days after initiation of antibiotics for bacteraemia due to methicillin-resistant Staphylococcus aureus (MRSA), developed acute chest pain followed by haemodynamic instability. A tamponade due to a rupture into the pericardium of the ascending aorta at the site of an atherosclerotic plaque was diagnosed by an emergent chest contrasted computed tomography (CT). Intraoperatively, the septic nature of the rupture was suspected. All aortic atherosclerotic plaque samples grew MRSA. Postoperatively, the patient had an uneventful recovery after 12 weeks of antibiotic therapy. Transoesophageal echocardiography and chest CT were normal at 3 months after cessation of antibiotics. This case report permits the review of some characteristics of this disease, its physiopathology as well as the therapeutic implications. PMID:22728897

Maillet, Jean Michel; Palombi, Tonino; Sablayrolles, Jean-Louis; Bonnet, Nicolas

2012-01-01

214

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

215

Intravascular photoacoustic imaging of gold nanorod-labeled atherosclerotic plaques  

NASA Astrophysics Data System (ADS)

Combined intravascular photoacoustic (IVPA) and intravascular ultrasound (IVUS) imaging has been previously established as a viable means for imaging atherosclerotic plaques using both endogenous and exogenous contrast. In this study, IVUS/IVPA imaging of an atherosclerotic rabbit aorta following injection of gold nanorods (AuNR) with peak absorbance within the tissue optical window was performed. Ex-vivo imaging results revealed high photoacoustic signal from localized AuNR. Corresponding histological cross-sections and digital photographs of the artery lumen confirmed the presence of AuNR preferentially located at atherosclerotic regions and in agreement with IVPA signal. Furthermore, an integrated IVUS/IVPA imaging catheter was used to image the AuNR in the presence of luminal blood. The results suggest that AuNR allow for IVPA imaging of exogenously labeled atherosclerotic plaques with a comparatively low background signal and without the need for arterial flushing.

Yeager, Doug; Karpiouk, Andrei; Wang, Bo; Amirian, James; Sokolov, Konstantin; Smalling, Richard; Emelianov, Stanislav

2012-02-01

216

Paraneoplastic plaque-like cutaneous mucinosis: a case report.  

PubMed

Plaque-like cutaneous mucinosis (PCM) is a rare disorder of dermal mucin deposition. Some patients with PCM will be found to have an associated malignancy. We report the case of a 72-year-old man presenting with new onset pruritic, waxy-appearing erythematous and skin-colored papules and nodules coalescing into plaques on his shoulder, scalp, and forehead. Skin biopsy revealed cutaneous mucinosis. Despite conservative treatment, his skin lesions progressed, and he was found to have an occult malignancy of pancreatobiliary origin. After several months of chemotherapy, his skin lesions showed progressive improvement. To our knowledge, this is the third reported case of paraneoplastic PCM and the first reported to occur in association with underlying adenocarcinoma of pancreatobiliary origin. PCM may occasionally represent a paraneoplastic dermatosis. This case highlights the importance of a search for occult malignancy in such patients. PMID:25756478

Owen, Joshua L; Word, Andrew P; Vandergriff, Travis; Desai, Seemal R

2014-01-01

217

Focal skin toxicity related to methotrexate sparing psoriatic plaques.  

PubMed

Methotrexate (MTX) is an antimetabolite and antifolate drug used in the treatment of cancer and autoimmune diseases. MTX inhibits DNA synthesis by competitive inhibition of dihydrofolate reductase in immunologically active cells. It also decreases inflammation by other mechanisms. Cutaneous toxicity is usually dose-related and generally occurs when recommended guidelines are ignored or there is a decrease in renal excretion. Self-medication is a problem with unknown prevalence. Signs of MTX toxicity include bone marrow suppression, hepatotoxicity, and mucocutaneous toxicity. Painful erosions of psoriatic plaques and, less commonly, erosions in patients without psoriasis have been reported as an early sign of MTX toxicity. To our knowledge, this is the first case of skin toxicity related to MTX that affected the normal skin and spared the psoriatic plaques. PMID:20579471

Truchuelo, Teresa; Alcántara, Javier; Moreno, Carmen; Vano-Galván, Sergio; Jaén, Pedro

2010-01-01

218

MRI Plaque Imaging Detects Carotid Plaques with a High Risk for Future Cerebrovascular Events in Asymptomatic Patients  

PubMed Central

Purpose The aim of this study was to investigate prospectively whether MRI plaque imaging can identify patients with asymptomatic carotid artery stenosis who have an increased risk for future cerebral events. MRI plaque imaging allows categorization of carotid stenosis into different lesion types (I–VIII). Within these lesion types, lesion types IV–V and VI are regarded as rupture-prone plaques, whereas the other lesion types represent stable ones. Methods Eighty-three consecutive patients (45 male (54.2%); age 54–88 years (mean 73.2 years)) presenting with an asymptomatic carotid stenosis of 50–99% according to ECST-criteria were recruited. Patients were imaged with a 1.5-T scanner. T1-, T2-, time-of-flight-, and proton-density weighted studies were performed. The carotid plaques were classified as lesion type I–VIII. Clinical endpoints were ischemic stroke, TIA or amaurosis fugax. Survival analysis and log rank test were used to ascertain statistical significance. Results Six out of 83 patients (7.2%) were excluded: 4 patients had insufficient MR image quality; 1 patient was lost-to-follow-up; 1 patient died shortly after the baseline MRI plaque imaging. The following results were obtained by analyzing the remaining 77 patients. The mean time of follow-up was 41.1 months. During follow-up, n?=?9 (11.7%) ipsilateral ischemic cerebrovascular events occurred. Only patients presenting with the high-risk lesion types IV–V and VI developed an ipsilateral cerebrovascular event versus none of the patients presenting with the stable lesion types III, VII, and VIII (n?=?9 (11.7%) vs. n?=?0 (0%) during follow-up). Event-free survival was higher among patients with the MRI-defined stable lesion types (III, VII, and VIII) than in patients with the high-risk lesion types (IV–V and VI) (log rank test P<0.0001). Conclusions MRI plaque imaging has the potential to identify patients with asymptomatic carotid stenosis who are particularly at risk of developing future cerebral ischemia. MRI could improve selection criteria for invasive therapy in the future. PMID:23894291

Esposito-Bauer, Lorena; Saam, Tobias; Ghodrati, Iman; Pelisek, Jaroslav; Heider, Peter; Bauer, Matthias; Wolf, Petra; Bockelbrink, Angelina; Feurer, Regina; Sepp, Dominik; Winkler, Claudia; Zepper, Peter; Boeckh-Behrens, Tobias; Riemenschneider, Matthias; Hemmer, Bernhard; Poppert, Holger

2013-01-01

219

DSC characterisation of compression moulded PEEK-PTFE plaques  

Microsoft Academic Search

Compression moulded plaques of a range of poly(ether ether ketone) (PEEK)- poly(tetrafluoroethylene) (PTFE) blends (100, 92,\\u000a 48, 29, 9.5 and 0 mass% PEEK) have been characterised using differential scanning calorimetry (DSC) and wide angle X-ray crystallography\\u000a (WAXD). A shift in the melting peak of the PEEK phase from 347 to 358C was observed with increasing proportion of PTFE in\\u000a the

P. S. Thomas; B. H. Stuart

2003-01-01

220

Copper, iron and zinc in Alzheimer's disease senile plaques  

Microsoft Academic Search

Concentrations of copper (Cu), iron (Fe) and zinc (Zn) were measured in the rims and cores of senile plaques (SP) and in the neuropil of the amygdala of nine Alzheimer's disease (AD) patients and in the neuropil of the amygdala of five neurologically normal control subjects using micro particle-induced X-ray emission (micro-PIXE). Comparison of SP rim and core values revealed

M. A Lovell; J. D Robertson; W. J Teesdale; J. L Campbell; W. R Markesbery

1998-01-01

221

Ossified frontosphenoorbital meningioma en plaque, mimicking extensive hyperostosis.  

PubMed

Small intratumoral calcifications are often seen within meningioma, but ossification of the whole neoplasm is very rare. The case of an ossified frontosphenoorbital meningioma en plaque is presented. The radiological appearance resembled extensive hyperostosis extending from the anterior clinoid process to the cerebral convexity and falx cerebri. It is possible that, in some cases of meningioma, the identified "hyperostosis" represents partial ossification of the tumor itself. PMID:18683118

Kato, K; Chernov, M; Urino, T; Kasuya, H; Kubo, O; Iseki, H; Hori, T

2008-08-01

222

Optical detection of structural changes in human carotid atherosclerotic plaque  

NASA Astrophysics Data System (ADS)

Background: Arterial bifurcations are commonly the sites of developing atherosclerotic plaque that lead to arterial occlusions and plaque rupture (myocardial infarctions and strokes). Laser induced fluorescence (LIF) spectroscopy provides an effective nondestructive method supplying spectral information on extracellular matrix (ECM) protein composition, specifically collagen and elastin. Purpose: To investigate regional differences in the ECM proteins -- collagen I, III and elastin in unstable plaque by analyzing data from laser-induced fluorescence spectroscopy of human carotid endarterectomy specimens. Methods: Gels of ECM protein extracts (elastin, collagen types I & III) were measured as reference spectra and internal thoracic artery segments (extra tissue from bypass surgery) were used as tissue controls. Arterial segments and the endarterectomy specimens (n=21) were cut into 5mm cross-sectional rings. Ten fluorescence spectra per sampling area were then recorded at 5 sites per ring with argon laser excitation (357nm) with a penetration depth of 200 ?m. Spectra were normalized to maximum intensity and analyzed using multiple regression analysis. Tissue rings were fixed in formalin (within 3 hours of surgery), sectioned and stained with H&E or Movat's Pentachrome for histological analysis. Spectroscopy data were correlated with immunohistology (staining for elastin, collagen types I, III and IV). Results: Quantitative fluorescence for the thoracic arteries revealed a dominant elastin component on the luminal side -- confirmed with immunohistology and known artery structure. Carotid endarterectomy specimens by comparison had a significant decrease in elastin signature and increased collagen type I and III. Arterial spectra were markedly different between the thoracic and carotid specimens. There was also a significant elevation (p<0.05) of collagen type I distal to the bifurcation compared to proximal tissue in the carotid specimens. Conclusion: Fluorescence spectroscopy is an effective method for evaluating ECM (collagen and elastin) associated with vascular remodeling despite the considerable variability in the plaque structure. Consistent regional differences were detected in the carotid specimens.

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

2005-08-01

223

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

224

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

225

A rotational ablation tool for calcified atherosclerotic plaque removal.  

PubMed

Atherosclerosis is a major cardiovascular disease involving accumulations of lipids, white blood cells, and other materials on the inside of artery walls. Since the calcification found in the advanced stage of atherosclerosis dramatically enhances the mechanical properties of the plaque, restoring the original lumen of the artery remains a challenge. High-speed rotational atherectomy, when performed with an ablating grinder to remove the plaque, produces much better results in the treatment of calcified plaque compared to other methods. However, the high-speed rotation of the Rotablator commercial rotational atherectomy device produces microcavitation, which should be avoided because of the serious complications it can cause. This research involves the development of a high-speed rotational ablation tool that does not generate microcavitation. It relies on surface modification to achieve the required surface roughness. The surface roughness of the tool for differential cutting was designed based on lubrication theory, and the surface of the tool was modified using Nd:YAG laser beam engraving. Electron microscope images and profiles indicated that the engraved surface of the tool had approximately 1 ?m of root mean square surface roughness. The ablation experiment was performed on hydroxyapatite/polylactide composite with an elastic modulus similar to that of calcified plaque. In addition, differential cutting was verified on silicone rubber with an elastic modulus similar to that of a normal artery. The tool performance and reliability were evaluated by measuring the ablation force exerted, the size of the debris generated during ablation, and through visual inspection of the silicone rubber surface. PMID:21792606

Kim, Min-Hyeng; Kim, Hyung-Jung; Kim, Nicholas N; Yoon, Hae-Sung; Ahn, Sung-Hoon

2011-12-01

226

Perforin expression in plaque psoriasis: an immunohistochemical study.  

PubMed

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

2015-04-01

227

Biofilms, a new approach to the microbiology of dental plaque  

Microsoft Academic Search

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

Jacob M. ten Cate

2006-01-01

228

Potential contributions of intimal and plaque hypoxia to atherosclerosis.  

PubMed

Injury of arterial endothelium by abnormal shear stress and other insults induces migration and proliferation of vascular smooth muscle cells (VSMCs), which in turn leads to intimal thickening, hypoxia, and vasa vasorum angiogenesis. The resultant new blood vessels extend from the tunica media into the outer intima, allowing blood-borne oxidized low-density lipoprotein (oxLDL) particles to accumulate in outer intimal tissues by extravasation through local capillaries. In response to oxLDL accumulation, monocytes infiltrate into arterial wall tissues, where they differentiate into macrophages and subsequently evolve into foam cells by uptaking large quantities of oxLDL particles, the latter process being stimulated by hypoxia. Increased oxygen demand due to expanding macrophage and foam cell populations contributes to persistent hypoxia in plaque lesions, whereas hypoxia further promotes plaque growth by stimulating angiogenesis, monocyte infiltration, and oxLDL uptake into macrophages. Molecularly, the accumulation of hypoxia-inducible factor (HIF)-1? and the expression of its target genes mediate many of the hypoxia-induced processes during plaque initiation and growth. It is hoped that further understanding of the underlying mechanisms may lead to novel therapies for effective intervention of atherosclerosis. PMID:25876920

Fong, Guo-Hua

2015-06-01

229

HDL-Mimetic PLGA Nanoparticle To Target Atherosclerosis Plaque Macrophages.  

PubMed

High-density lipoprotein (HDL) is a natural nanoparticle that exhibits an intrinsic affinity for atherosclerotic plaque macrophages. Its natural targeting capability as well as the option to incorporate lipophilic payloads, e.g., imaging or therapeutic components, in both the hydrophobic core and the phospholipid corona make the HDL platform an attractive nanocarrier. To realize controlled release properties, we developed a hybrid polymer/HDL nanoparticle composed of a lipid/apolipoprotein coating that encapsulates a poly(lactic-co-glycolic acid) (PLGA) core. This novel HDL-like nanoparticle (PLGA-HDL) displayed natural HDL characteristics, including preferential uptake by macrophages and a good cholesterol efflux capacity, combined with a typical PLGA nanoparticle slow release profile. In vivo studies carried out with an ApoE knockout mouse model of atherosclerosis showed clear accumulation of PLGA-HDL nanoparticles in atherosclerotic plaques, which colocalized with plaque macrophages. This biomimetic platform integrates the targeting capacity of HDL biomimetic nanoparticles with the characteristic versatility of PLGA-based nanocarriers. PMID:25650634

Sanchez-Gaytan, Brenda L; Fay, Francois; Lobatto, Mark E; Tang, Jun; Ouimet, Mireille; Kim, YongTae; van der Staay, Susanne E M; van Rijs, Sarian M; Priem, Bram; Zhang, Liangfang; Fisher, Edward A; Moore, Kathryn J; Langer, Robert; Fayad, Zahi A; Mulder, Willem J M

2015-03-18

230

Rhenium and technetium complexes that bind to amyloid-? plaques.  

PubMed

Alzheimer's disease is associated with the presence of insoluble protein deposits in the brain called amyloid plaques. The major constituent of these deposits is aggregated amyloid-? peptide. Technetium-99m complexes that bind to amyloid-? plaques could provide important diagnostic information on amyloid-? plaque burden using Single Photon Emission Computed Tomography (SPECT). Tridentate ligands with a stilbene functional group were used to form complexes with the fac-[M(I)(CO)3](+) (M = Re or (99m)Tc) core. The rhenium carbonyl complexes with tridentate co-ligands that included a stilbene functional group and a dimethylamino substituent bound to amyloid-? present in human frontal cortex brain tissue from subjects with Alzheimer's disease. This chemistry was extended to make the analogous [(99m)Tc(I)(CO)3](+) complexes and the complexes were sufficiently stable in human serum. Whilst the lipophilicity (log?D7.4) of the technetium complexes appeared ideally suited for penetration of the blood-brain barrier, preliminary biodistribution studies in an AD mouse model (APP/PS1) revealed relatively low brain uptake (0.24% ID g(-1) at 2 min post injection). PMID:25515141

Hayne, David J; North, Andrea J; Fodero-Tavoletti, Michelle; White, Jonathan M; Hung, Lin W; Rigopoulos, Angela; McLean, Catriona A; Adlard, Paul A; Ackermann, Uwe; Tochon-Danguy, Henri; Villemagne, Victor L; Barnham, Kevin J; Donnelly, Paul S

2015-03-01

231

Heterogeneity of Inflammatory and Cytokine Networks in Chronic Plaque Psoriasis  

PubMed Central

The clinical features of psoriasis, characterized by sharply demarcated scaly erythematous plaques, are typically so distinctive that a diagnosis can easily be made on these grounds alone. However, there is great variability in treatment response between individual patients, and this may reflect heterogeneity of inflammatory networks driving the disease. In this study, whole-genome transcriptional profiling was used to characterize inflammatory and cytokine networks in 62 lesional skin samples obtained from patients with stable chronic plaque psoriasis. We were able to stratify lesions according to their inflammatory gene expression signatures, identifying those associated with strong (37% of patients), moderate (39%) and weak inflammatory infiltrates (24%). Additionally, we identified differences in cytokine signatures with heightened cytokine-response patterns in one sub-group of lesions (IL-13-strong; 50%) and attenuation of these patterns in a second sub-group (IL-13-weak; 50%). These sub-groups correlated with the composition of the inflammatory infiltrate, but were only weakly associated with increased risk allele frequency at some psoriasis susceptibility loci (e.g., REL, TRAF3IP2 and NOS2). Our findings highlight variable points in the inflammatory and cytokine networks known to drive chronic plaque psoriasis. Such heterogeneous aspects may shape clinical course and treatment responses, and can provide avenues for development of personalized treatments. PMID:22479649

Swindell, William R.; Xing, Xianying; Stuart, Philip E.; Chen, Cynthia S.; Aphale, Abhishek; Nair, Rajan P.; Voorhees, John J.; Elder, James T.; Johnston, Andrew; Gudjonsson, Johann E.

2012-01-01

232

[Ultrasound-guided ESWT in Peyronie's disease plaques].  

PubMed

The aim of the study was to check the efficiency of shock waves in the treatment of Peyronie's disease. The instrument, because of its lithotriptic power, already used in the treatment of orthopedic disease and salivary stones, can be used to break plaques in induratio penis plastica. A total of 481 patients affected with Peyronie's disease were entered into a prospective trial. Patients with big plaques or with an initial stage of degeneration were excluded. We divided the patients into three treatment groups: a) shock waves alone in 56 patients; b) a combination of shock waves and calcioantagonist (perilesional injection) in 324 patients; c) calcioantagonist alone in 101 patients. The group of 101 patients (group C) treated during the previous 2 years with a medical therapy based only on the injection of calcioantagonist, was used as a control group. Ultrasound evaluation of the treated plaques showed a reduction of size in 27/56 patients of the group A, in 159/324 patients of the group B and in 39/101 patients of group C. Painful erection improved in the 91.5% of group B, against the 45.7% of group C. Furthermore, we pointed out, with interviews to the patients, a considerable improvement of the pain and of the sexual performances. The therapeutic association of shock waves with calcioantagonist injections is an effective non-operative treatment for the stabilization of Peyronie's disease. PMID:11221076

Mirone, V; Palmieri, A; Granata, A M; Piscopo, A; Verze, P; Ranavolo, R

2000-12-01

233

Molecular imaging of apolipoprotein B-100 in human coronary plaques by color fluorescent angioscopy and microscopy.  

PubMed

Apolipoprotein B-100 (ApoB-100) is an important risk factor for coronary artery disease. However, its localization in human coronary plaques is not well understood. The present study was performed to visualize ApoB-100 in human coronary artery wall. Deposition of native ApoB-100 in excised human coronary plaques and normal segments classified by conventional angioscopy was investigated by color fluorescent angioscopy (CFA) and microscopy (CFM) using Nile blue dye (NB) which elicits a golden fluorescence characteristic of ApoB-100 as a biomarker. By CFA, the % incidence of ApoB-100 was 20 in 40 normal segments, 38 in 42 white, and 11 in 35 yellow plaques (P < 0.05 versus white plaques). There was no significant difference in detection sensitivity between CFA and luminal surface scan by CFM. By CFM transected surface scan, ApoB-100 deposited in superficial, deep, and/or in both layers. Deposition in both layers was frequently observed in white plaques and yellow plaques without necrotic core (NC), less frequently in normal segments, and rarely in yellow plaques with NC. (1) Taking into consideration the well known process of plaque growth, the results suggest that ApoB-100 begins to deposit before plaque formation, increasingly deposits with plaque growth, and disappears after necrotic core formation. (2) CFA is feasible for imaging of ApoB-100 in human coronary artery wall. PMID:23676365

Hiruta, Nobuyuki; Uchida, Yasuto; Maezawa, Yuko; Shimoyama, Ei; Uchida, Yasumi

2013-01-01

234

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

NASA Astrophysics Data System (ADS)

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

Kasraie, Nima; Clarke, Geoffrey D.

2012-02-01

235

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

236

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

237

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

PubMed Central

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

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

1989-01-01

238

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

239

Spectral CT imaging of vulnerable plaque with two independent biomarkers  

NASA Astrophysics Data System (ADS)

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

Baturin, Pavlo; Alivov, Yahya; Molloi, Sabee

2012-07-01

240

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

241

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

242

The Effects of Xylitol-containing Chewing Gums on Dental Plaque and Acidogenic Potential  

Microsoft Academic Search

The aim of this study was to test the hypothesis that the chewing of xylitol- or xylitol\\/sorbitol-containing chewing gum reduces plaque formation and the acidogenic potential of dental plaque. Thirty healthy volunteers aged from 19 to 28 yrs were randomly allocated to one of three test groups, chewing either xylitol-, xylitol\\/sorbitol-, or sucrose-sweetened gums. A three-day plaque accumulation period of

A. Aa. Scheie; O. Fejerskov; B. Danielsen

1998-01-01

243

Cyclic Bending Contributes to High Stress in a Human Coronary Atherosclerotic Plaque and Rupture Risk  

PubMed Central

Many acute cardiovascular syndromes such as heart attack and stroke are caused by atherosclerotic plaque ruptures which often happen without warning. MRI-based models with fluid-structure interactions (FSI) have been introduced to perform flow and stress/strain analysis for atherosclerotic plaques and identify possible mechanical and morphological indices for accurate plaque vulnerability assessment. In this paper, cyclic bending was added to 3D FSI coronary plaque models for more accurate mechanical predictions. Curvature variation was prescribed using the data of a human left anterior descending (LAD) coronary artery. Five computational models were constructed based on ex vivo MRI human coronary plaque data to assess the effects of cyclic bending, pulsating pressure, plaque structure, and axial stretch on plaque stress/strain distributions. In vitro experiments using a hydrogel stenosis model with cyclical bending were performed to observe effect of cyclical bending on flow conditions. Our results indicate that cyclical bending may cause more than 100% or even up to more than 1000% increase in maximum principal stress values at locations where the plaque is bent most. Stress increase is higher when bending is coupled with axial stretch, non-smooth plaque structure, or resonant pressure conditions (zero phase angle shift). Effects of cyclic bending on flow behaviors are more modest (21.6% decrease in maximum velocity, 10.8% decrease in flow rate, maximum flow shear stress changes were < 5%). Computational FSI models including cyclic bending, plaque components and structure, axial stretch, accurate in vivo measurements of pressure, curvature, and material properties should lead to significant improvement on stress-based plaque mechanical analysis and more accurate coronary plaque vulnerability assessment. PMID:19412353

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

2009-01-01

244

Genetic mapping of the determinants of plaque morphology of coxsackievirus B4  

Microsoft Academic Search

Summary The genetic determinants of plaque size of two variants of coxsackievirus B4, CB4-P and CB4-V, were identified using a panel of recombinant, chimeric viruses. When grown in monkey kidney cells, CB4-V yielded large plaques with an average size of 1.0 cm while CB4-P yielded small plaques with an average size of 0.4 cm. Two genetic domains, the 5' untranslated

A. I. Ramsingh; M. Caggana; S. Ronstrom

1995-01-01

245

View of Commemorative plaque left on moon at Hadley-Apennine landing site  

NASA Technical Reports Server (NTRS)

A close-up view of a commemorative plaque left on the Moon at the Hadley-Apennine landing site in memory of 14 NASA astronauts and USSR cosmonauts, now deceased. Their names are inscribed in alphabetical order on the plaque. The plaque was stuck in the lunar soil by Astronauts David R. Scott and James B. Irwin during their Apollo 15 lunar surface extravehicular activity. The tin, man-like object represents the figure of a fallen astronaut/cosmonaut.

1971-01-01

246

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

Microsoft Academic Search

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

LOUISE ST-CYR; ADELE A. CROWDER

1990-01-01

247

Human atheromatous plaques stimulate thrombus formation by activating platelet glycoprotein VI  

Microsoft Academic Search

Lipid-rich atherosclerotic plaques are vulnerable, and their rupture can cause the formation of a platelet- and fibrin-rich thrombus leading to myo- cardial infarction and ischemic stroke. Although the role of plaque-based tissue factor as stimulator of blood coagulation has been recognized, it is not known whether plaques can cause thrombus formation through direct activation of platelets. We isolated lipid- rich

Sandra Penz; Armin J. Reininger; Richard Brandl; Pankaj Goyal; Tamer Rabie; Isabell Bernlochner; Enno Rother; Christine Goetz; Bernd Engelmann; Peter A. Smethurst; Willem H. Ouwehand; Richard Farndale; Bernhard Nieswandt; Wolfgang Siess

2005-01-01

248

Matrix metalloproteinase-2 of human carotid atherosclerotic plaques promotes platelet activation. Correlation with ischaemic events.  

PubMed

Purified active matrix metalloproteinase-2 (MMP-2) is able to promote platelet aggregation. We aimed to assess the role of MMP-2 expressed in atherosclerotic plaques in the platelet-activating potential of human carotid plaques and its correlation with ischaemic events. Carotid plaques from 81 patients undergoing endarterectomy were tested for pro-MMP-2 and TIMP-2 content by zymography and ELISA. Plaque extracts were incubated with gel-filtered platelets from healthy volunteers for 2 minutes before the addition of a subthreshold concentration of thrombin receptor activating peptide-6 (TRAP-6) and aggregation was assessed. Moreover, platelet deposition on plaque extracts immobilised on plastic coverslips under high shear-rate flow conditions was measured. Forty-three plaque extracts (53%) potentiated platelet aggregation (+233 ± 26.8%), an effect prevented by three different specific MMP-2 inhibitors (inhibitor II, TIMP-2, moAb anti-MMP-2). The pro-MMP-2/TIMP-2 ratio of plaques potentiating platelet aggregation was significantly higher than that of plaques not potentiating it (3.67 ± 1.21 vs 1.01 ± 0.43, p<0.05). Moreover, the platelet aggregation-potentiating effect, the active-MMP-2 content and the active MMP-2/pro-MMP-2 ratio of plaque extracts were significantly higher in plaques from patients who developed a subsequent major cardiovascular event. In conclusion, atherosclerotic plaques exert a prothrombotic effect by potentiating platelet activation due to their content of MMP-2; an elevated MMP-2 activity in plaques is associated with a higher rate of subsequent ischaemic cerebrovascular events. PMID:24499865

Lenti, Massimo; Falcinelli, Emanuela; Pompili, Marcella; de Rango, Paola; Conti, Valentina; Guglielmini, Giuseppe; Momi, Stefania; Corazzi, Teresa; Giordano, Giuseppe; Gresele, Paolo

2014-06-01

249

A comparative immunohistochemical study of Kuru and senile plaques with a special reference to glial reactions at various stages of amyloid plaque formation.  

PubMed Central

The authors examined 10 patients with Gerstmann-Sträussler syndrome or Creutzfeldt-Jakob disease and 10 with Alzheimer's disease (AD). Immunohistochemistry using anti-prion protein (PrP) and anti-beta/A4 protein (beta/A4) coupled with formic acid pretreatment could detect Congophilic and non-Congophilic deposits. Prion protein deposits were classified into five types and compared with types of beta/A4 deposits. Kuru plaques with multicentric cores and fine granular deposits were a characteristic feature of PrP deposits. Some types of PrP or beta/A4 deposits depend on the anatomic sites. To clarify the relationship of microglia and astrocytes to PrP or beta/A4 deposits, double-immunostaining method was performed. In both kuru and senile plaques, microglia were closely linked to the Congophilic plaques. Astrocytes, however, extended their processes toward the plaques even in the non-Congophilic plaques. These observations strongly suggest that similar glial association with plaque formation may be involved in both kuru and senile plaques, although the amyloid core proteins differ. Images Figure 1 Figure 4 p595-a Figure 5 PMID:1679596

Miyazono, M.; Iwaki, T.; Kitamoto, T.; Kaneko, Y.; Doh-ura, K.; Tateishi, J.

1991-01-01

250

Comparison of 16 mm OSU-Nag and COMS eye plaques.  

PubMed

OSU-NAG eye plaques use fewer sources than COMS-plaques of comparable size, and do not employ a Silastic seed carrier insert. Monte Carlo modeling was used to calculate 3D dose distributions for a 16 mm OSU-NAG eye plaque and a 16 mm COMS eye plaque loaded with either Iodine-125 or Cesium-131 brachytherapy sources. The OSU-NAG eye plaque was loaded with eight sources forming two squares, whereas the COMS eye plaque was loaded with thirteen sources approximating three isocentric circles. A spherical eyeball 24.6 mm in diameter and an ellipsoid-like tumor 6 mm in height and 12 mm in the major and minor axes were used to evaluate the doses delivered. To establish a fair comparison, a water seed carrier was used instead of the Silastic seed carrier designed for the traditional COMS eye plaque. Calculations were performed on the dose distributions along the eye plaque axis and the DVHs of the tumor, as well as the 3D distribution. Our results indicated that, to achieve a prescription dose of 85 Gy at 6 mm from the inner sclera edge for a six-day treatment, the OSU-NAG eye plaque will need 6.16 U/source and 6.82U/source for 125I and 131Cs, respectively. The COMS eye plaque will require 4.02 U/source and 4.43 U/source for the same source types. The dose profiles of the two types of eye plaques on their central axes are within 9% difference for all applicable distances. The OSU-NAG plaque delivers about 10% and 12% more dose than the COMS for 125I and 131Cs sources, respectively, at the inner sclera edge, but 6% and 3% less dose at the opposite retina. The DVHs of the tumor for two types of plaques were within 6% difference. In conclusion, the dosimetric quality of the OSU-NAG eye plaque used in eye plaque brachytherapy is comparable to the COMS eye plaque. PMID:22584165

Zhang, Hualin; Davidorf, Frederick; Qi, Yujin

2012-01-01

251

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

252

Relation of amylase to starch and Lycasin metabolism in human dental plaque in vitro.  

PubMed

Acid production activity (APA) in plaque suspensions from glucose, boiled soluble starch and hydrogenated starch hydrolysate (Lycasin) was studied in 11 subjects. Amylase (alpha-1,4-glucan 4-glucanohydrolase, EC 3.2.1.1) activity was measured in plaque and whole saliva samples from the same persons. Lycasin was found to be hydrolyzed by salivary amylase under the formation of di- and oligosaccharides, however, with a lower rate than starch. A high correlation was found between APA from glucose and from soluble starch and between APA from soluble starch and plaque amylase activity. No correlation was found between amylase activity in saliva and APA from soluble starch or between amylase activity in saliva or plaque and APA from Lycasin. APA from Lycasin was about 62% and from soluble starch about 76% of the APA from glucose. 0-25% of the total number of cultivable microorganisms from the plaque produced extracellular starch-degrading enzymes. No correlation was found between number of starch-degrading microorganisms and APA from soluble starch or between these numbers and the plaque amylase activity. By electrophoreses only amylase fractions of human origin were found in whole saliva, plaque supernatants and plaque suspensions, indicating that the microbial amylase activity in the plaque is low compared with that of salivary origin. PMID:279956

Birkhed, D; Skude, G

1978-07-01

253

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

254

Integrated IVUS-OCT Imaging for Atherosclerotic Plaque Characterization  

PubMed Central

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

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

2014-01-01

255

A classic collaboration: Michael Davies on plaque vulnerability.  

PubMed

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

Born, G V R; Richardson, P D

2012-02-01

256

A Reduced Astrocyte Response to ?-Amyloid Plaques in the Ageing Brain Associates with Cognitive Impairment  

PubMed Central

Aims ?-amyloid (A?) plaques are a key feature of Alzheimer’s disease pathology but correlate poorly with dementia. They are associated with astrocytes which may modulate the effect of A?-deposition on the neuropil. This study characterised the astrocyte response to A? plaque subtypes, and investigated their association with cognitive impairment. Methods A? plaque subtypes were identified in the cingulate gyrus using dual labelling immunohistochemistry to A? and GFAP+ astrocytes, and quantitated in two cortical areas: the area of densest plaque burden and the deep cortex near the white matter border (layer VI). Three subtypes were defined for both diffuse and compact plaques (also known as classical or core-plaques): A? plaque with (1) no associated astrocytes, (2) focal astrogliosis or (3) circumferential astrogliosis. Results In the area of densest burden, diffuse plaques with no astrogliosis (? = -0.05, p = 0.001) and with focal astrogliosis (? = -0.27, p = 0.009) significantly associated with lower MMSE scores when controlling for sex and age at death. In the deep cortex (layer VI), both diffuse and compact plaques without astrogliosis associated with lower MMSE scores (? = -0.15, p = 0.017 and ? = -0.81, p = 0.03, respectively). Diffuse plaques with no astrogliosis in layer VI related to dementia status (OR = 1.05, p = 0.025). In the area of densest burden, diffuse plaques with no astrogliosis or with focal astrogliosis associated with increasing Braak stage (? = 0.01, p<0.001 and ? = 0.07, p<0.001, respectively), and ApoE?4 genotype (OR = 1.02, p = 0.001 and OR = 1.10, p = 0.016, respectively). In layer VI all plaque subtypes associated with Braak stage, and compact amyloid plaques with little and no associated astrogliosis associated with ApoE?4 genotype (OR = 1.50, p = 0.014 and OR = 0.10, p = 0.003, respectively). Conclusions Reactive astrocytes in close proximity to either diffuse or compact plaques may have a neuroprotective role in the ageing brain, and possession of at least one copy of the ApoE?4 allele impacts the astroglial response to A? plaques. PMID:25707004

Mathur, Ryan; Ince, Paul G.; Minett, Thais; Garwood, Claire J.; Shaw, Pamela J.; Matthews, Fiona E.; Brayne, Carol

2015-01-01

257

Coronary CT angiography in patients with high calcium score: evaluation of plaque characteristics and diagnostic accuracy.  

PubMed

Our aim was to evaluate the plaque characteristics of coronary arteries related to significant stenosis with coronary CT angiography (CCTA) and to discuss the diagnostic accuracy of CCTA in patients with high calcium scores. After institutional review board approval, 110 patients (63 men; mean age: 67.1 ± 7.9 years) with Agatston scores >400 were retrospectively reviewed. Patients underwent Agatston calcium scoring and 64-slice CCTA, in addition to invasive coronary angiography (CAG). The composition (calcified, mixed, and non-calcified) and configuration (concentric, eccentric) of coronary artery plaques were analyzed on a per-segment basis by CCTA. We analyzed the differences in plaque composition and configuration between significant (? 50%) and non-significant (<50%) stenosis. Additionally, the diagnostic accuracy of stenosis according to plaque composition was evaluated by CCTA, using CAG as a reference method. Significant differences in plaque composition and configurations were observed between the two groups. In cases of significant stenosis, the proportions of concentric, mixed, and non-calcified plaques were significantly higher than those of eccentric and calcified plaques (P < 0.001). The sensitivity and positive predictive value of mixed (97.4, 87.6%) and non-calcified plaques (97.8, 95.7%) were significantly higher than those of calcified plaques (87.6, 67.2%). Although CCTA has limited value due to low diagnostic accuracy of calcified plaques, knowledge about the high frequencies of mixed and non-calcified plaques in significant stenosis help to make an accurate assessment of CAD with CCTA in patients with high calcium scores. PMID:22048849

Park, Mi Jung; Jung, Jung Im; Choi, Yun-Seok; Ann, Soe Hee; Youn, Ho-Joong; Jeon, Gyeong Nyeo; Choi, Ho Cheol

2011-12-01

258

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

PubMed Central

Background Previous studies have shown that coronary plaque composition plays a pivotal role in plaque instability, and imaging modalities and serum biomarkers have been investigated to identify vulnerable plaque. Virtual histology IVUS (VH-IVUS) characterizes plaque components as calcified, fibrotic, fibrofatty, or necrotic core. C-reactive protein (hsCRP) is an independent risk factor and a powerful predictor of future coronary events. However, a relationship between inflammatory response indicated by CRP and plaque characteristics in ACS patients remains not well established. Objective To determine, by using VH-IVUS, the relation between coronary plaque components and plasma high-sensitivity CRP levels in patients with acute coronary syndromes (ACS). Methods 52 patients with ACS were enrolled in this prospective study. Electrocardiographically-gated VH-IVUS were performed in the culprit lesion before PCI. Blood sample was drawn from all patients before the procedure and after 24 hours, and hs-CRP levels were determined. Results Mean age was 55.3±4.9 years, 76.9% were men and 30.9% had diabetes. Mean MLA was 3.9±1.3 mm2, and plaque burden was 69±11.3%, as assessed by IVUS. VH-IVUS analysis at the minimum luminal site identified plaque components: fibrotic (59.6±15.8%), fibrofatty (7.6±8.2%), dense calcium (12.1±9.2%) and necrotic core (20.7±12.7%). Plasma hs-CRP (mean 16.02±18.07 mg/L) did not correlate with necrotic core (r=-0.089, p = 0.53) and other plaque components. Conclusions In this prospective study with patients with ACS, the predominant components of the culprit plaque were fibrotic and necrotic core. Serum hs C-reactive protein levels did not correlate with plaque composition. PMID:23752339

Siqueira, Dimytri Alexandre de Alvim; Sousa, Amanda Guerra Moraes R.; Costa Junior, José de Ribamar; da Costa, Ricardo Alves; Staico, Rodolfo; Tanajura, Luis Fernando Leite; Centemero, Marinella Patrizia; Feres, Fausto; Abizaid, Alexandre Antonio Cunha; Sousa, J. Eduardo Moraes R.

2013-01-01

259

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

260

[Effect of iron plaque on root surfaces on phosphorus uptake of two wetland plants].  

PubMed

In situ micro-suction cups were used to collect samples of soil solution with Arundo donax Linn and Typha latifolia from defined segments at rhizosphere in field. The experiment was conducted to elucidate the contribution of iron plaque while wetland plants were used to remove phosphorus. The reddish iron plaque was observed and measured on the surfaces of roots of Arundo donax Linn and Typha latifolia in the field, 20,170.8 mg/kg (fresh weight) for Arundo donax Linn and 7640.3 mg/kg (fresh weight) for Typha latifolia were collected. Olsen-P contents of Arundo donax Linn with iron plaque were 28.85 mg/kg, 46.2% more than that of without, 34.99 mg/kg for Typha latifolia 21.9% more than that of without. The phosphate concentrations in the in situ rhizosphere soil solution of Arundo donax Linn with iron plaque were 0.65 mg/kg, 9.2% more than that of without, 0.56 mg/kg for Typha latifolia, 33.9% more than that of without. The phosphorus contents adsorbed by iron plaque were 81.7% for Arundo donax Linn and 85.7% for Typha latifolia of the wetland plants with iron plaque. Phosphate use efficiency of Arundo donax Linn with iron plaque was 16.5% more than that of without, 31.4% for Typha latifolia. The contents of phosphorus of single plant of the two wetland plants with iron plaque are higher than that of without. Due to adsorb phosphate with iron plaque, the transfer speeds of phosphate from non-rhizosphere to rhizosphere and from soil to soil solution are increasing. The phosphorus contents with iron plaque accumulated at rhizosphere and depleted at rhizosphere without iron plaque of Arundo donax Linn and Typha latifolia. PMID:20358843

Wang, Zhen-yu; Liu, Li-hua; Wen, Sheng-fang; Peng, Chang-sheng; Xing, Bao-shan; Li, Feng-min

2010-03-01

261

Anti?Inflammatory Immune Skewing Is Atheroprotective: Apoe?/?Fc?RIIb?/? Mice Develop Fibrous Carotid Plaques  

PubMed Central

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

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

2014-01-01

262

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

263

How Does Calcification Influence Plaque Vulnerability? Insights from Fatigue Analysis  

PubMed Central

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

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

2014-01-01

264

In Vivo Magnetic Resonance Imaging of Amyloid-? Plaques in Mice  

PubMed Central

Transgenic mice are used increasingly to model brain amyloidosis, mimicking the pathogenic processes involved in Alzheimer's disease (AD). In this chapter, an in vivo strategy is described that has been successfully used to map amyloid-? deposits in transgenic mouse models of AD with magnetic resonance imaging (MRI), utilizing both the endogenous contrast induced by the plaques attributed to their iron content and by selectively enhancing the signal from amyloid-? plaques using molecular-targeting vectors labeled with MRI contrast agents. To obtain sufficient spatial resolution for effective and sensitive mouse brain imaging, magnetic fields of 7-Tesla (T) or more are required. These are higher than the 1.5-T field strength routinely used for human brain imaging. The higher magnetic fields affect contrast agent efficiency and dictate the choice of pulse sequence parameters for in vivo MRI, all addressed in this chapter. Two-dimensional (2D) multi-slice and three-dimensional (3D) MRI acquisitions are described and their advantages and limitations are discussed. The experimental setup required for mouse brain imaging is explained in detail, including anesthesia, immobilization of the mouse's head to reduce motion artifacts, and anatomical landmarks to use for the slice alignment procedure to improve image co-registration during longitudinal studies and for subsequent matching of MRI with histology. PMID:22528108

Wadghiri, Youssef Zaim; Hoang, Dung Minh; Wisniewski, Thomas; Sigurdsson, Einar M.

2013-01-01

265

Lipoprotein apheresis reduces biomarkers of plaque destabilization and cardiovascular risk.  

PubMed

Lipoprotein apheresis (LA) is believed to exert anti-atherosclerotic effects beyond LDL-cholesterol reduction. We investigated 22 patients undergoing regular LA on a weekly basis (group A) before (AP) and after LA procedure (EP), 15 healthy individuals (group B), and 22 hyperlipoproteinemic patients with concomitant cardiovascular end organ damage treated without LA therapy (group C). Biomarkers of endothelial inflammation (hsCRP), plaque destabilization, and rupture (sVCAM, MMP-9, PAPP-A, ADMA) were quantified. Intergroup comparison revealed a statistically significant lower MMP-9 level in group A (AP and EP) compared with group C (P?plaque destabilization and elevated cardiovascular risk after a single LA treatment. PMID:24281903

Strauchmann, Julia; Wallbach, Manuel; Bramlage, Carsten; Puls, Miriam; Konstantinides, Stavros; Mueller, Gerhard A; Koziolek, Michael J

2014-10-01

266

Evidence-based control of plaque and gingivitis.  

PubMed

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

Santos, A

2003-01-01

267

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

268

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

Microsoft Academic Search

It is well accepted that atherosclerosis initiation and progression correlate positively with low and oscillating flow wall shear stresses (FSS). However, this mechanism cannot explain why advanced plaques continue to grow under elevated FSS conditions. In vivo magnetic resonance imaging (MRI)-based 2D\\/3D multi-component models with fluid–structure interactions (FSI, 3D only) for human carotid atherosclerotic plaques were introduced to quantify correlations

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

2008-01-01

269

Combined iodine-125 plaque irradiation and indirect ophthalmoscope laser therapy of choroidal malignant melanomas: Comparison with iodine-125 and cobalt-60 plaque radiotherapy alone  

Microsoft Academic Search

The authors studied the short-term impact of combined episcleral iodine-125 plaque radiotherapy and argon laser treatment in a series of 24 patients with choroidal malignant melanoma. All patients underwent plaque therapy prior to their initial laser session. All laser treatments were performed with an indirect ophthalmoscope argon green laser, using low-power, long-duration exposures. The endpoint of laser therapy was a

James J. Augsburger; Markus Kleineidam; Donald Mullen

1993-01-01

270

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 that is not readily accessible from currently available technology. Amyloid plaque accumulation in the brain discriminate be- tween different types of amyloid deposits in brain. The discriminating capability

Theodorakis, Emmanuel

271

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

272

Antimicrobial Susceptibility and Composition of Microcosm Dental Plaques Supplemented with Sucrose  

Microsoft Academic Search

The aims of this study were to evaluate the effects of repeated chlorhexidine gluconate (CHG) pulsing on the viability and bacterial composition of microcosm dental plaques derived from human saliva. The biofilms were grown on bovine enamel discs in a constant-depth film fermentor fed with an artificial saliva which was supplemented thrice daily with sucrose. The microcosm plaques had total

J. PRATTEN; M. WILSON; Eastman Dental

1999-01-01

273

A catheter-based radiation detector for endovascular detection of atheromatous plaques  

Microsoft Academic Search

Purpose Although various radiopharmaceuticals have been developed for the detection of atheromas, external imaging techniques have limitations when it comes to the detection of small plaques. In this study, we developed a charged particle-sensitive detector for the endovascular detection of small plaques. Methods The device consists of a probe, an automatic pullback unit and a controller. The probe, which consists

Takahiro Mukai; Ryuji Nohara; Mikako Ogawa; Seigo Ishino; Naoshige Kambara; Kazuaki Kataoka; Toru Kanoi; Kazuhiro Saito; Hiroshi Motomura; Junji Konishi; Hideo Saji

2004-01-01

274

A Catheter-Based Intravascular Radiation Detector ofVulnerablePlaques  

Microsoft Academic Search

Detection of vulnerable plaques before rupture is important in preventing acute coronary events such as myocardial infarction. Althoughtherapeuticstrategiessuchaspercutaneoustranslumi- nal coronary angioplasty appear to prevent coronary occlusion and consequently may lead to improved prognosis in these pa- tients, a method of detecting vulnerable plaques has not been established. A nuclear method that uses an intravascular radia- tion detector (IVRD) with the

Ryohei Hosokawa; Naoshige Kambara; Muneo Ohba; Takahiro Mukai; Mikako Ogawa; Hiroshi Motomura; Noriaki Kume; Hideo Saji; Toru Kit; Ryuji Nohara

275

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

Microsoft Academic Search

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

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

1990-01-01

276

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

Microsoft Academic Search

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

K. Küsel; A. Chabbi; T. Trinkwalter

2003-01-01

277

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

278

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

PubMed

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

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

1994-12-01

279

Photographic replica of plaque Apollo 15 astronauts will leave on Moon  

NASA Technical Reports Server (NTRS)

A photographic replica of the plaque which Apollo 15 astronauts will leave behind on the Moon during their lunar landing mission. The seven by nine-inch stainless steel plaque will be attached to the ladder on the landing gear strut on the Lunar Module's descent stage.

1971-01-01

280

View of replica of plaque Apollo 12 astronauts will leave on the Moon  

NASA Technical Reports Server (NTRS)

Close-up view of a replica of the plaque which the Apollo 12 astronauts will leave on the Moon in commemoration of their flight. The plaque will be attached to the ladder on the landing gear strut on the descent stage of the Apollo 12 Lunar Module.

1969-01-01

281

Photographic replica of the plaque Apollo 13 astronauts will leave on moon  

NASA Technical Reports Server (NTRS)

A photographic replica of the plaque which the Apollo 13 astronauts will leave behind on the Moon during their lunar landing mission. The plaque will be attached to the ladder on the landing gear strut on the Lunar Module's descent stage.

1970-01-01

282

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

NASA Astrophysics Data System (ADS)

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

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

2015-04-01

283

TNF Inhibition Rapidly Down-Regulates Multiple Proinflammatory Pathways in Psoriasis Plaques1  

Microsoft Academic Search

The mechanisms of action of marketed TNF-blocking drugs in lesional tissues are still incompletely understood. Because psoriasis plaques are accessible to repeat biopsy, the effect of TNF\\/lymphotoxin blockade with etanercept (soluble TNFR) was studied in ten psoriasis patients treated for 6 months. Histological response, inflammatory gene expression, and cellular infiltration in psoriasis plaques were evaluated. There was a rapid and

Alice B. Gottlieb; Francesca Chamian; Salman Masud; Irma Cardinale; Maria Veronica Abello; Michelle A. Lowes; Fei Chen; Melissa Magliocco; James G. Krueger

2005-01-01

284

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

285

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

PubMed

Different immune cell types are present within atherosclerotic plaques. Dendritic cells (DC) are of special interest, since they are considered as the 'center of the immuniverse'. Identifying inflammatory DC subtypes within plaques is important for a better understanding of the lesion pathogenesis and pinpoints their contribution to the atherosclerotic process. We have developed a flow cytometry-based method to characterize and isolate different DC subsets (i.e. CD11b(+), Clec9A(+) and CD16(+) conventional (c)DC and CD123(+) plasmacytoid (p)DC) in human atherosclerotic plaques. We revealed a predominance of pro-inflammatory CD11b(+) DC in advanced human lesions, whereas atheroprotective Clec9A(+) DC were almost absent. CD123(+) pDC and CD16(+) DC were also detectable in plaques. Remarkably, plaques from distinct anatomical locations exhibited different cellular compositions: femoral plaques contained less CD11b(+) and Clec9A(+) DC than carotid plaques. Twice as many monocytes/macrophages were observed compared to DC. Moreover, relative amounts of T cells/B cells/NK cells were 6 times as high as DC numbers. For the first time, fluorescent activated cell sorting analysis of DC subsets in human plaques indicated a predominance of CD11b(+) cDC, in comparison with other DC subsets. Isolation of the different subsets will facilitate detailed functional analysis and may have significant implications for tailoring appropriate therapy. PMID:25527343

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

2015-02-01

286

Beta-Ray Brachytherapy of Retinoblastoma: Feasibility of a New Small-Sized Ruthenium106 Plaque  

Microsoft Academic Search

A non-comparative case observation study estimated the feasibility of brachytherapy for retinoblastoma with a newly designed ruthenium-106 plaque (label: CXS) with an 8-mm diameter of the irradiation zone. Methods: The new CXS plaque was used between 2001 and 2003 for brachytherapy of 13 retinoblastomas. Indications were recurrences after preceding local treatment or endophytic retinoblastoma with an impending vitreous tumour cell

Andreas O. Schueler; Dirk Flühs; Gerasimos Anastassiou; Christine Jurklies; Wolfgang Sauerwein; Norbert Bornfeld

2006-01-01

287

Activation of ?2-adrenergic receptor stimulates ?-secretase activity and accelerates amyloid plaque formation  

Microsoft Academic Search

Amyloid plaque is the hallmark and primary cause of Alzheimer disease. Mutations of presenilin-1, the ?-secretase catalytic subunit, can affect amyloid-? (A?) production and Alzheimer disease pathogenesis. However, it is largely unknown whether and how ?-secretase activity and amyloid plaque formation are regulated by environmental factors such as stress, which is mediated by receptors including ?2-adrenergic receptor (?2-AR). Here we

Yanxiang Ni; Xiaohui Zhao; Guobin Bao; Lin Zou; Lin Teng; Zhu Wang; Min Song; Jiaxiang Xiong; Yun Bai; Gang Pei

2006-01-01

288

Histometric Assessment of Psoriatic Plaques Treated by Vitamin D3 Derivatives  

Microsoft Academic Search

Background: Psoriasis is an immunogenetic disorder. Factor XIIIa+ dermal dendrocytes (DD) are part of the pathobiological changes in the plaque type of the disease. Objective: The present study aimed at comparing the effect of 3 vitamin D3 derivatives on the epidermis, microvasculature and DD in psoriasis. Method: Twenty men suffering from chronic plaques of psoriasis on the trunk were enrolled

Isabelle Uhoda; Pascale Quatresooz; Trinh Hermanns-Lê; Claudine Piérard-Franchimont; Jorge E. Arrese; Gérald E. Piérard

2003-01-01

289

Relationship Between Ultrasonic Attenuation, Size and Axial Strain Parameters for Ex Vivo Atherosclerotic Carotid Plaque  

Microsoft Academic Search

Many ultrasonic parameters, primarily related to attenuation and scatterer size, have been used to characterize the composition of atherosclerotic plaque tissue. In this study, we combine elastographic (axial strain ratio) and ultrasonic tissue characterization parameters, namely the attenuation coefficient and a scattering parameter associated with an “equivalent” scatterer size to delineate between fibrous, calcified, and lipidic plaque tissue. We present

Hairong Shi; Tomy Varghese; Robert J. Dempsey; Mohammed S. Salamat; James A. Zagzebski

2008-01-01

290

Human Root Caries: Microbiota in Plaque Covering Sound, Carious and Arrested Carious Root Surfaces  

Microsoft Academic Search

The plaque microbiota covering sound or carious root surfaces were studied and compared with that covering arrested root caries lesions. From each of these categories five extracted teeth were examined. The experimental design of the study allowed us to relate the qualitative and quantitative microbial composition to the degree of integrity of the root surface. Plaque was sampled by a

P. Schüpbach; V. Osterwalder; B. Guggenheim

1995-01-01

291

Impact of Preoperative Dental Plaque Culture for Predicting Postoperative Pneumonia in Esophageal Cancer Patients  

Microsoft Academic Search

Background\\/Aims: In esophageal cancer patients, postoperative pneumonia frequently occurs. In the oral cavity, dental plaque is a major reservoir of bacteria, and it is possible that oral bacteria are aspirated into the upper respiratory tract after esophagectomy. We evaluated the interaction between preoperative dental plaque and postoperative pneumonia in patients undergoing esophagectomy. Patients and Methods: Thirty-nine patients with thoracic esophageal

Yasunori Akutsu; Hisahiro Matsubara; Shinichi Okazumi; Hideaki Shimada; Kiyohiko Shuto; Toru Shiratori; Takenori Ochiai

2008-01-01

292

Dental plaque as a biofilm and a microbial community – implications for health and disease  

Microsoft Academic Search

Dental plaque is a structurally- and functionally-organized biofilm. Plaque forms in an ordered way and has a diverse microbial composition that, in health, remains relatively stable over time (microbial homeostasis). The predominant species from diseased sites are different from those found in healthy sites, although the putative pathogens can often be detected in low numbers at normal sites. In dental

Philip D Marsh

2006-01-01

293

Neuritic plaque-like structures in the rat cerebellum following prolonged alcohol consumpotion  

Microsoft Academic Search

Summary Primitive neuritic plaques were observed in the inner third of the molecular layer of the cerebellar cortex of rats following chronic alcohol consumption. Neurites were indentified as dystrophic parallel fiber bouton. Amyloid material dispersed among neurites was not clearly recognized, dystrophic some fibrils were frequently seen among them. Astrocytic processes were noted in the periphery of the plaque. Microglial

M. M. Paula-Barbosa; M. A. Tavares

1984-01-01

294

Novel anti-microbial therapies for dental plaque-related diseases  

Microsoft Academic Search

Control of dental plaque-related diseases has traditionally relied on non-specific removal of plaque by mechanical means. As our knowledge of oral disease mechanisms increases, future treatment is likely to be more targeted, for example at small groups of organisms, single species or at key virulence factors they produce. The aim of this review is to consider the current status as

Robert P. Allaker; C. W. Ian Douglas

2009-01-01

295

Simian rotavirus SA-11 plaque formation in the presence of trypsin.  

PubMed Central

Incorporation of 5 micrograms of trpsin per ml of the overlay (Eagle minimal essential medium-0.7% Ionagar no. 2) was found to be necessary for plaque formation by simian rotavirus SA-11. Plaques of 3 to 4 mm in diameter were produced in MA-104 cells after 5 days of incubation at 37 degrees C. Plaque size was even larger (5 to 6 mm) in monolayers of African green monkey kidney cells. Addition of diethyl-aminotheyl-dextran, protamine sulfate, or 5-bromodeoxyuridine to the trypsin-containing overlay did not improve plaque formation by the virus. Incorporation of beef extract or yeast extract to a final concentration of 0.5% in the trypsin-containing overlay inhibited plaque formation. On the other hand, the presence of lactalbumin hydrolysate or peptone at a similar concentration in the overlay did not inhibit plaque formation. When methylcellulose was used instead of the agar as the solidifying agent in the overlay, no plaques were seen. SA-11 is a useful model for the study of human rotaviruses, and this relatively simple plaque assay system should further enhance its usefulness in this regard. Images PMID:94597

Ramia, S; Sattar, S A

1979-01-01

296

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

297

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

298

Plaque Therapy and Scatter Dose Using {sup 252}Cf Sources  

SciTech Connect

As melanomas are radioresistant to conventional low-linear energy transfer (LET) radiations such as photons and electrons, {sup 252}Cf (high-LET due to neutrons) may offer more promising clinical results. Although {sup 252}Cf also emits photons and electrons, the majority of absorbed dose is imparted by the high-LET radiation. This study examines the impact of scattering material on the neutron dose distributions for {sup 252}Cf plaque therapy (used to treat surface lesions like melanoma). Neutrons were transported through a 10-cm-diam water phantom with a thickness of either 5 or 10 cm using the MCNP radiation transport code. The phantom was surrounded by vacuum; the {sup 252}Cf neutron energy spectrum was modeled as a Maxwellian distribution; and the source was a bare point positioned at 1.0, 0.5, or {epsilon} above or below the water/vacuum interface. These source positions were chosen to mimic the case where a plaque locates the source either above the skin's surface, e.g., 2{pi} scattering geometry, or if layers of tissue-equivalent bolus materials were placed atop the implant to provide radiation backscatter, 4{pi} geometry. Differences between the 2{pi} and 4{pi} geometries were maximized closest to the source and for source positions farthest from the water/vacuum interface. Therefore, the maximum radiation dose (closest to the {sup 252}Cf source) may be minimized by not including scattering material for plaque therapy. However, for nonrelativistic, elastic scattering for protons by neutrons, the proton range increases with neutron energy. This result was expected since the neutron energy spectrum degrades at increasing depth and the proportion of fast neutron dose to total dose is maximized closest to the source in the 2{pi} geometry. Future studies will examine this effect as a function of neutron energy, will consider synergy with the low-LET {sup 252}Cf dose component and include experimental measurements, and will assess this technique to possibly improve in vivo dose distributions.

Mark J. Rivard; Anita Mahajan

2000-11-12

299

Heme oxygenase-1 inhibits progression and destabilization of vulnerable plaques in a rabbit model of atherosclerosis.  

PubMed

Although heme oxygenase-1 (HO-1) has been implicated in protection against atherogenesis, its role in vulnerable plaques remains to be fully elucidated. This study was aimed to explore the effect of HO-1 on the progression and stabilization of vulnerable plaques and the possible mechanism. We established a vulnerable plaque model by local transfection with recombinant p53 adenovirus to plaques in rabbits fed a high-cholesterol diet. HO-1 activity was modulated by intraperitoneal injection of hemin or Sn-protoporphyrin IX (SnPP). HO-1 induction by hemin inhibited the progression of atherosclerotic lesions and changed the plaque morphology and composition into a more stable phenotype. In addition, hemin treatment is associated with a reduction in matrix metalloproteinase-9, interleukin-6 and tumor necrosis factor-? production, an increase in interleukin-10 level, as well as a decrease of TUNEL labeled apoptosis of smooth muscle cells in lesions. Compared with the control group, aortic nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity decreased markedly, whereas endothelial nitric oxide synthase (eNOS) activity increased significantly in the Hemin group. In contrast, inhibition of HO-1 by SnPP induced reversed effects and augmented plaque progression and vulnerability. After pharmacological triggering, the incidence of plaque disruption in SnPP group was significantly higher than that in control group (79% vs. 33%, P<0.05), while no plaque in Hemin group developed disruption (0% vs. 33%, P<0.05). These findings suggest that HO-1 induction could delay progression and enhance stability of atherosclerotic plaques, possibly through the attenuation of plaque inflammation and apoptosis, and the suppression of iNOS/NO production. PMID:22004613

Li, Tingting; Tian, Hongbo; Zhao, Yuxia; An, Fengshuang; Zhang, Lei; Zhang, Jianning; Peng, Jie; Zhang, Yun; Guo, Yuan

2011-12-15

300

Evaluation of a 3D technique for quantifying neovascularization within plaques imaged by contrast enhanced ultrasound.  

PubMed

Intra-plaque neovascularization and inflammation are considered as important indicators of plaque vulnerability, which when ruptured, may cause stroke or acute myocardial infarction. The purpose of this research was to validate and evaluate a semi-automatic method, which allows quantification of carotid plaque neovascularization using contrast-enhanced ultrasound cines, thus enabling assessment of plaque vulnerability. The method detects contrast clusters in the images, and tracks them, to generate over time a path that portrays the neovasculature. It classifies the paths as either artifacts or `blood vessels' and reconstructs the 3D arterial tree. Software-based phantom was developed to represent volumetric structures of the carotid lumen, the plaque, and `objects' passing through the intra-plaque neovasculature. These 3D objects, which mimic microbubbles or clusters of microbubbles, were based on original 2D formations, imaged during clinical examinations using contrast-enhanced ultrasound. Within a plaque, several paths were constructed, representing flow inside blood vessels, and several isolated objects were added, representing artifacts. Different paths were generated, classified into 4 groups: separate paths, paths that merge at some point, paths that branch and intersecting paths. The phantom was used to generate sets of cines, which were then processed by the method. The method identified artifacts and different paths, which were then compared to the `true' ones. Sixty-four 'objects' in 16 movies were examined. All of them were detected. 79% of those objects were well tracked and classified to either artifacts or real blood vessels. The results of this study show that the method accurately identifies artifacts and paths, which allows reconstruction of intra-plaque vascular tree and quantification of the plaque neovasculature, which is associated with plaque vulnerability. PMID:24109890

Hoogi, Assaf; Zurakhov, Grigoriy; Adam, Dan

2013-01-01

301

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

302

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

303

Exchange of unsaturated fatty acids between adipose tissue and atherosclerotic plaque studied with artificial neural networks.  

PubMed

The linoleic C18:2 (n-6) and linolenic C18:3 (n-3) are recognized as essential components of the diet. Free radical peroxidation of essential fatty acids (EFAs) present in lipoproteins produces oxidized low-density lipoproteins which play a critical role in the development of atherosclerosis. The accumulation of EFAs in the vascular wall and correlations between their content in the adipose tissue and atherosclerotic plaque have been confirmed. The present study was undertaken to determine the usefulness of a neural network for studying the exchange between tissues of linoleic, alpha-linolenic, and arachidonic acids-three fatty acids with a well-understood metabolism. Atheromatous plaques, adipose tissue, and serum were obtained from 31 patients who underwent surgery due to atherosclerotic stenosis of the abdominal aorta, iliac or femoral arteries. Fatty acids were extracted and separated as methyl esters using gas chromatography. Statistical analysis was done with STATISTICA neural networks package. Several correlations reported previously were corroborated and factors modifying the content of individual EFAs in adipose tissue and atherosclerotic plaque were revealed. Artificial neural networks (ANNs) were used to determine factors modifying the content of linoleic, alpha-linolenic, and arachidonic acids in human atheromatous plaques. The mechanism of exchange of some fatty acids between the adipose tissue, atheromatous plaque, and plasma is discussed. The results provide evidence for an effective mechanism of tissue uptake and turnover of linoleic acid. Reduced plasma levels of this acid are compensated by release from adipose tissue and atheromatous plaque. While alpha-linolenic acid is continuously taken up by the plaque, adipose tissue absorbs this acid to a certain level only. The dynamics of exchange of arachidonic acid between adipose tissue and atheromatous plaque reflects a minor role for adipose tissue in determining plaque content of this acid, suggesting that "de novo" synthesis is the chief source of arachidonic acid in plaques. PMID:14643180

Stachowska, E; Gutowska, I; Do?egowska, B; Chlubek, D; Bober, J; Ra?, M; Gutowski, P; Szumilowicz, H; Turowski, R

2004-01-01

304

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

305

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

306

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

NASA Astrophysics Data System (ADS)

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

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

2007-04-01

307

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

308

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

309

Association of Randall's Plaques with Collagen Fibers and Membrane Vesicles  

PubMed Central

Background Idiopathic calcium oxalate (CaOx) kidney stones develop by deposition of CaOx crystals on Randall's plaques (RP). Mechanisms involved in RP formation are still unclear. Objective It is our hypotheses that RP formation is similar to vascular calcification involving components of extracellular matrix including membrane bound vesicles (MV) and collagen fibers. In order to verify our hypothesis we critically examined renal papillary tissue from stone patients. Methods 4 mm cold-cup biopies of renal papillae were performed on fifteen idiopathic stone patients undergoing PCNL. Tissue was immediately fixed and processed for analyses by various light and electron microscopic techniques. Results and Limitations Spherulitic CaP crystals, the hallmark of RP's, were seen in all samples examined. They were seen in interstitium as well as laminated basement membrane of tubular epithelia. Large crystalline deposits comprised of dark elongated strands mixed with spherulites. Strands showed banded patterns similar to collagen. Crystal deposits were surrounded by collagen fibers and membrane bound vesicles. Energy dispersive x-ray microanalyses (EDX) and electron diffraction identified the crystals as hydroxyapatite. The number of kidneys examined is small and urinary data was not available for all the patients. Conclusions Results presented here show that crystals in the Randall's plaques are associated with both the collagen as well as MV. Collagen fibers appeared calcified and vesicles contained crystals. We conclude that crystal deposition in renal papillae may have started with membrane vesicle induced nucleation and grew by addition of crystals on the periphery within a collagen framework. PMID:22266007

Khan, Saeed R.; Rodriguez, Douglas E.; Gower, Laurie B.; Monga, Manoj

2013-01-01

310

Identification of Atherosclerotic Plaques in Carotid Artery by Fluorescence Spectroscopy  

NASA Astrophysics Data System (ADS)

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

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

2008-04-01

311

Bacterial diversity of subgingival plaque in 6 healthy Chinese individuals  

PubMed Central

The subgingival microbial ecology is complex, and little is known regarding its bacteria species composition in healthy Chinese individuals. This study aimed to identify the subgingival microbiota from 6 healthy Chinese subjects. Subgingival samples from 6 volunteers were collected, the 16S rRNA gene was amplified using broad-range bacterial primers, and clone libraries were constructed. For the initial 2,439 sequences analyzed, 383 species-level operational taxonomic units (SLOTUs) belonging to seven phyla were identified, estimated as 51% [95% confidence interval (CI) 44–55] of the SLOTUs in this ecosystem. Most (85%) of the bacterial sequences, falling into 228 types of species, corresponded to known and cultivated species. However, 146 (6%) sequences, comprising 104 phylotypes, had <97% similarity to prior database sequences. Ten bacterial genera were conserved among all 6 individuals, comprising 2,000 (82%) of the 2,439 clones analyzed. Ten species were noted in all of the 6 subjects, comprising 1,435 (58.8%) of the 2,439 clones. Streptococcus infantis was the species most frequently cloned. Furthermore, certain species which may participate in the pathogenesis of periodontal disease were present in the 6 subjects. Although the initial subgingival plaque community of each subject was unique in terms of diversity and composition, 10 common key species were found in the 6 Chinese individuals. These ten species of bacteria in the human subgingival plaque in the 6 healthy individuals may be key species which, to some extent, affect periodontal health. Destruction of these key species in subgingival bacteria may break the microbiota balance and may easily lead to over-breeding conditions resulting in pathogenic oral disease. PMID:22977615

ZHANG, SONG-MEI; TIAN, FEI; HUANG, QING-FENG; ZHAO, YAN-FANG; GUO, XIAO-KUI; ZHANG, FU-QIANG

2011-01-01

312

Demographics and characterization of 10,282 randall plaque-related kidney stones: a new epidemic?  

PubMed

Renal stone incidence has progressively increased in industrialized countries, but the implication of Randall plaque in this epidemic remains unknown. Our objectives were to determine whether the prevalence of Randall plaque-related stones increased during the past decades after having analyzed 30,149 intact stones containing mainly calcium oxalate since 1989 (cross-sectional study), and to identify determinants associated with Randall plaque-related stones in patients (case-control study).The proportion of Randall plaque-related stones was assessed over 3 time periods: 1989-1991, 1999-2001, and 2009-2011. Moreover, we analyzed clinical and biochemical parameters of 105 patients affected by calcium oxalate stones, with or without plaque.Of 30,149 calcium oxalate stones, 10,282 harbored Randall plaque residues (34.1%). The prevalence of Randall plaque-related stones increased dramatically during the past years. In young women, 17% of calcium oxalate stones were associated with Randall plaque during the 1989-1991 period, but the proportion rose to 59% 20 years later (P?plaques experienced their first stone-related event earlier in life as compared with those without plaque (median age 26 vs 34 years, P?=?0.02), had increased ionized serum calcium levels (P?=?0.04), and increased serum osteocalcin (P?=?0.001) but similar 25-hydroxyvitamin D levels. The logistic regression analysis showed that age (odds ratio [OR] 0.96, confidence interval [CI] 0.926-0.994, P?=?0.02), weight (OR 0.97, CI 0.934-0.997, P?=?0.03), and osteocalcin serum levels (OR 1.12, CI 1.020-1.234, P?=?0.02) were independently associated with Randall plaque. The prevalence of the FokI f vitamin D receptor polymorphism was higher in patients with plaque (P?=?0.047).In conclusion, these findings point to an epidemic of Randall plaque-associated renal stones in young patients, and suggest a possible implication of altered vitamin D response. PMID:25761176

Letavernier, Emmanuel; Vandermeersch, Sophie; Traxer, Olivier; Tligui, Mohamed; Baud, Laurent; Ronco, Pierre; Haymann, Jean-Philippe; Daudon, Michel

2015-03-01

313

Molecular Imaging of Low-density Lipoprotein in Human Coronary Plaques by Color Fluorescent Angioscopy and Microscopy  

PubMed Central

Objectives Low-density lipoprotein (LDL) is an important risk factor for coronary artery disease. However, its localization in human coronary plaques is not well understood. The present study was performed to visualize LDL in human coronary artery wall. Methods (1) The fluorescence characteristic of LDL was investigated by color fluorescent microscopy (CFM) with excitation at 470-nm and emission at 515-nm using Nile blue dye (NB) as a biomarker. (2) Native LDL in 40 normal segments, 42 white plaques and 35 yellow plaques (20 with necrotic core) of human coronary arteries was investigated by color fluorescent angioscopy (CFA) and CFM. Results (1) NB elicited a brown, golden and red fluorescence characteristic of LDL, apolipoprotein B-100, and lysophosphatidylcholine/triglyceride, respectively. (2) The % incidence of LDL in normal segments, white, and yellow plaques was 25, 38 and 14 by CFA and 42, 42 and 14 by CFM scan of their luminal surface, respectively, indicating lower incidence (p<0.05) of LDL in yellow plaques than white plaques, and no significant differences in detection sensitivity between CFA and CFM. By CFM transected surface scan, LDL deposited more frequently and more diffusely in white plaques and yellow plaques without necrotic core (NC) than normal segments and yellow plaques with NC. LDL was localized to fibrous cap in yellow plaques with NC. Co-deposition of LDL with other lipid components was observed frequently in white plaques and yellow plaques without NC. Conclusions (1) Taken into consideration of the well-known process of coronary plaque growth, the results of the present study suggest that LDL begins to deposit before plaque formation; increasingly deposits with plaque growth, often co-depositing with other lipid components; and disappears after necrotic core formation. (2) CFA is feasible for visualization of LDL in human coronary artery wall. PMID:23209809

Uchida, Yasumi; Maezawa, Yuko; Uchida, Yasuto; Hiruta, Nobuyuki; Shimoyama, Ei

2012-01-01

314

Meshless Generalized Finite Difference Method and Human Carotid Atherosclerotic Plaque Progression Simulation Using Multi-Year MRI Patient-Tracking Data.  

PubMed

Atherosclerotic plaque rupture and progression have been the focus of intensive investigations in recent years. Plaque rupture is closely related to most severe cardiovascular syndromes such as heart attack and stroke. A computational procedure based on meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating patients were scanned three times (T(1), T(2), and T(3), at intervals of about 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Since there was insufficient data with the current technology to quantify individual plaque component growth, the whole plaque was assumed to be uniform, homogeneous, hyperelastic, isotropic and nearly incompressible. The linear elastic model was used. The 2D plaque model was discretized and solved using a meshless generalized finite difference (GFD) method. Starting from the T(2) plaque geometry, plaque progression was simulated by solving the solid model and adjusting wall thickness using plaque growth functions iteratively until T(3) is reached. Numerically simulated plaque progression agreed very well with actual plaque geometry at T(3) given by MRI data. We believe this is the first time plaque progression simulation based on multi-year patient-tracking data was reported. Serial MRI-based progression simulation adds time dimension to plaque vulnerability assessment and will improve prediction accuracy for potential plaque rupture risk. PMID:19774222

Yang, Chun; Tang, Dalin; Yuan, Chun; Kerwin, William; Liu, Fei; Canton, Gador; Hatsukami, Thomas S; Atluri, Satya

2008-01-01

315

Meshless Generalized Finite Difference Method and Human Carotid Atherosclerotic Plaque Progression Simulation Using Multi-Year MRI Patient-Tracking Data  

PubMed Central

Atherosclerotic plaque rupture and progression have been the focus of intensive investigations in recent years. Plaque rupture is closely related to most severe cardiovascular syndromes such as heart attack and stroke. A computational procedure based on meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating patients were scanned three times (T1, T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Since there was insufficient data with the current technology to quantify individual plaque component growth, the whole plaque was assumed to be uniform, homogeneous, hyperelastic, isotropic and nearly incompressible. The linear elastic model was used. The 2D plaque model was discretized and solved using a meshless generalized finite difference (GFD) method. Starting from the T2 plaque geometry, plaque progression was simulated by solving the solid model and adjusting wall thickness using plaque growth functions iteratively until T3 is reached. Numerically simulated plaque progression agreed very well with actual plaque geometry at T3 given by MRI data. We believe this is the first time plaque progression simulation based on multi-year patient-tracking data was reported. Serial MRI-based progression simulation adds time dimension to plaque vulnerability assessment and will improve prediction accuracy for potential plaque rupture risk. PMID:19774222

Yang, Chun; Tang, Dalin; Yuan, Chun; Kerwin, William; Liu, Fei; Canton, Gador; Hatsukami, Thomas S.; Atluri, Satya

2009-01-01

316

Helicobacter pylori in dental plaque and stomach of patients from Northern Brazil  

PubMed Central

AIM: To establish whether virulence factor genes vacA and cagA are present in Helicobacter pylori (H. pylori) retrieved from gastric mucosa and dental plaque in patients with dyspepsia. METHODS: Cumulative dental plaque specimens and gastric biopsies were submitted to histological examination, rapid urease test and polymerase chain reaction (PCR) assays to detect the presence of cagA and vacA polymorphisms. RESULTS: Detection of H. pylori from dental plaque and gastric biopsy samples was greater by PCR compared to histological examination and the rapid urease test. DNA from H. pylori was detected in 96% of gastric mucosa samples and in 72% of dental plaque samples. Sixty-three (89%) of 71 dental plaque samples that were H. pylori-positive also exhibited identical vacA and cagA genotypes in gastric mucosa. The most common genotype was vacAs1bm1 and cagA positive, either in dental plaque or gastric mucosa. These virulent H. pylori isolates were involved in the severity of clinical outcome. CONCLUSION: These pathogenic strains were found simultaneously in dental plaque and gastric mucosa, which suggests that gastric infection is correlated with the presence of H. pylori in the mouth. PMID:20572307

Assumpção, Mônica Baraúna; Martins, Luisa Caricio; Melo Barbosa, Hivana Patricia; dos Santos Barile, Katarine Antonia; de Almeida, Sintia Silva; Assumpção, Paulo Pimentel; de Oliveira Corvelo, Tereza Cristina

2010-01-01

317

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

318

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

319

Diffuse Calcifications Protect Carotid Plaques regardless of the Amount of Neoangiogenesis and Related Histological Complications  

PubMed Central

Background. Neoangiogenesis is crucial in plaque progression and instability. Previous data from our group showed that Nestin-positive intraplaque neovessels correlated with histological complications. The aim of the present work is to evaluate the relationship between neoangiogenesis, plaque morphology, and clinical instability of the plaque. Materials and Methods. Seventy-three patients (53 males and 20 females, mean age 71 years) were consecutively enrolled. Clinical data and 14 histological variables, including intraplaque hemorrhage and calcifications, were collected. Immunohistochemistry for CD34 and Nestin was performed. RT-PCR was performed to evaluate Nestin mRNA (including 5 healthy arteries as controls). Results. Diffusely calcified plaques (13/73) were found predominantly in females (P = 0.017), with a significantly lower incidence of symptoms (TIA/stroke (P = 0.019) than noncalcified plaques but with the same incidence of histological complications (P = 0.156)). Accordingly, calcified and noncalcified plaques showed similar mean densities of positivity for CD34 and Nestin. Nestin density, but not CD34, correlated with the occurrence of intraplaque hemorrhage. Conclusions. Plaques with massive calcifications show the same incidence of histological complications but without influencing symptomatology, especially in female patients, and regardless of the amount of neoangiogenesis. These results can be applied in a future presurgical identification of patients at major risk of developing symptoms.

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

2015-01-01

320

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

PubMed

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

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

2014-05-01

321

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

NASA Astrophysics Data System (ADS)

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

Nagao, Ryo; Ishii, Katsunori; Awazu, Kunio

2014-03-01

322

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

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

323

Development and optimization of a direct plaque assay for human and avian metapneumoviruses  

PubMed Central

The genus Metapneumovirus within the subfamily Pneumovirinae and family Paramyxoviridae includes only two viruses, human metapneumovirus (hMPV) and avian metapneumovirus (aMPV), which cause respiratory disease in humans and birds, respectively. These two viruses grow poorly in cell culture and other quantitation methods, such as indirect immuno-staining and immuno-fluorescent assays, are expensive, time consuming, and do not allow for plaque purification of the virus. In order to enhance research efforts for studying these two viruses, a direct plaque assay for both hMPV and aMPV has been developed. By optimizing the chemical components of the agarose overlay, it was found that both hMPV with a trypsin-independent F cleavage site and aMPV formed clear and countable plaques in a number of mammalian cell lines (such as Vero-E6 and LLC-MK2 cells) after 5 days of incubation. The plaque forming assay has similar sensitivity and reliability as the currently used immunological methods for viral quantitation. The plaque assay is also a more simple, rapid, and economical method compared to immunological assays, and in addition allows for plaque purification of the viruses. The direct plaque assay will be a valuable method for the quantitation and evaluation of the biological properties of some metapneumoviruses. PMID:22684013

Zhang, Yu; Wei, Yongwei; Li, Junan; Li, Jianrong

2012-01-01

324

Silence of NLRP3 Suppresses Atherosclerosis and Stabilizes Plaques in Apolipoprotein E-Deficient Mice  

PubMed Central

Objectives. The role of the NLRP3 inflammasome in atherosclerosis remains controversial. The aim of this study was to determine whether inhibition of NLRP3 signaling by lentivirus-mediated RNA interference could reduce atherosclerosis and stabilizes plaques. We also tried to explore the mechanisms of the impact of NLRP3 inflammasome on atherosclerosis. Methods. Apolipoprotein E-deficient mice aged 8 weeks were fed a high-fat diet and were injected with NLRP3 interfering or mock viral suspension after 4 weeks. Lentivirus transfer was repeated in 2 weeks. Four weeks after the first lentivirus injection, we evaluated the effects of NLRP3 gene silencing on plaque composition and stability and on cholesterol efflux and collagen metabolism, by histopathologic analyses and real-time PCR. Results. Gene silence of NLRP3 prevented plaques progression and inhibited inductions of proinflammatory cytokines. Moreover, this RNA interference reduced plaque content of macrophages and lipid, and increased plaque content of smooth muscle cells and collagen, leading to the stabilizing of atherosclerotic plaques. Conclusions. NLRP3 inflammasomes may play a vital role in atherosclerosis, and lentivirus-mediated NLRP3 silencing would be a new strategy to inhibit plaques progression and to reduce local inflammation. PMID:24999295

Zheng, Fei; Xing, Shanshan; Gong, Zushun; Mu, Wei; Xing, Qichong

2014-01-01

325

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

326

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

327

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. PMID:25674314

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

2014-01-01

328

The carotid plaque imaging in acute stroke (CAPIAS) study: protocol and initial baseline data  

PubMed Central

Background In up to 30% of patients with ischemic stroke no definite etiology can be established. A significant proportion of cryptogenic stroke cases may be due to non-stenosing atherosclerotic plaques or low grade carotid artery stenosis not fulfilling common criteria for atherothrombotic stroke. The aim of the CAPIAS study is to determine the frequency, characteristics, clinical and radiological long-term consequences of ipsilateral complicated American Heart Association lesion type VI (AHA-LT VI) carotid artery plaques in patients with cryptogenic stroke. Methods/Design 300 patients (age >49 years) with unilateral DWI-positive lesions in the anterior circulation and non- or moderately stenosing (<70% NASCET) internal carotid artery plaques will be enrolled in the prospective multicenter study CAPIAS. Carotid plaque characteristics will be determined by high-resolution black-blood carotid MRI at baseline and 12 month follow up. Primary outcome is the prevalence of complicated AHA-LT VI plaques in cryptogenic stroke patients ipsilateral to the ischemic stroke compared to the contralateral side and to patients with defined stroke etiology. Secondary outcomes include the association of AHA-LT VI plaques with the recurrence rates of ischemic events up to 36 months, rates of new ischemic lesions on cerebral MRI (including clinically silent lesions) after 12 months and the influence of specific AHA-LT VI plaque features on the progression of atherosclerotic disease burden, on specific infarct patterns, biomarkers and aortic arch plaques. Discussion CAPIAS will provide important insights into the role of non-stenosing carotid artery plaques in cryptogenic stroke. The results might have implications for our understanding of stroke mechanism, offer new diagnostic options and provide the basis for the planning of targeted interventional studies. Trial Registration NCT01284933 PMID:24330333

2013-01-01

329

Early Canine Plaque Biofilms: Characterization of Key Bacterial Interactions Involved in Initial Colonization of Enamel  

PubMed Central

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

330

A Study of Bovine Virus Diarrhea Mucosal Disease Virus by Plaque Technique  

PubMed Central

Bovine virus diarrhea-mucosal disease (BVD-MD), NADL, strain formed 3-4 mm plaques on monolayers of bovine embryo kidney (BEK), lung and testicular (BET) cell cultures on post inoculation day four. Plaques were 1.5 mm on the post inoculation day five in lamb testicular cell cultures. Neutral red incorporated in first overlay had inhibitory effect on plaque formation in these cell-virus systems. The study of effects of environmental variables on plaquing efficiency indicated that virus adsorption rate was temperature dependent and approximately 80% virus was adsorbed onto BET monolayers in two hours. Rate of adsorption was slightly superior in BEK monolayers than the ones recorded in BET cell cultures. Virus diluent should contain calcium and magnesium ions for maximum plaquing efficiency. Cultures maintained under lamb serum should be washed for the development of maximum number of plaques. Virus particles could diffuse through agar overlay to initiate infection and form delayed plaques. Size of the plaques was proportional to the concentration of agar in overlay medium. Plaquing efficiency was also dependent upon pH of the overlay and optimum pH for maximum efficiency was 7.3 - 7.7. NADL strain of BVD-MD virus was sensitive to trypsin but resistant to 5'-Bromodeoxyuridine. Thermostability studies showed that 0.5% virus survived when incubated at 37°C for 48 hours. The virus was sensitive to freezing and thawing. Comparative titers of virus determined and expressed as PFU and TCID50 were almost similar. ImagesFig. I. PMID:4242771

Singh, K. V.

1969-01-01

331

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

SciTech Connect

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

Beiki-Ardakani, Akbar; Jezioranski, John; Jaffray, David A.; Yeung, Ivan [Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada) and Departments of Radiation Oncology and Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)

2008-10-15

332

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

PubMed

Mechanical response and properties of the arterial wall can be used to identify the biomechanical instability of plaques and predict their vulnerability to rupture. Shear strain elastography (SSE) is proposed to identify vulnerable plaque features attributed to mechanical structural heterogeneities. The aims of this study were: 1) to report on the potential of SSE to identify atherosclerotic plaques; and 2) to use SSE maps to highlight biomechanical changes in lesion characteristics after directional coronary atherectomy (DCA) interventions. For this purpose, SSE was imaged using in vivo intravascular ultrasound (IVUS) radio-frequency data collected from 12 atherosclerotic patients before and after DCA intervention. Coronary atherosclerotic plaques (pre-DCA) showed high SSE magnitudes with large affected areas. There were good correlations between SSE levels and soft plaque content (i.e., cellular fibrosis, thrombosis and fibrin) (mean |SSE| vs. soft plaque content: r = 0.82, p < 0.01). Significant differences were noticed between SSE images before and after DCA. Stable arteries (post-DCA) exhibited lower values than pre-DCA vessels (e.g., pre-DCA: mean |SSE| = 3.9 ± 0.2% vs. 1.1 ± 0.2% post-DCA, p < 0.001). Furthermore, SSE magnitude was statistically higher in plaques with a high level of inflammation (e.g., mean |SSE| had values of 4.8 ± 0.4% in plaques with high inflammation, whereas it was reduced to 1.8 ± 0.2% with no inflammation, p < 0.01). This study demonstrates the potential of the IVUS-based SSE technique to detect vulnerable plaques in vivo. PMID:24835433

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

2014-07-01

333

Effect of coconut oil in plaque related gingivitis — A preliminary report  

PubMed Central

Background: Oil pulling or oil swishing therapy is a traditional procedure in which the practitioners rinse or swish oil in their mouth. It is supposed to cure oral and systemic diseases but the evidence is minimal. Oil pulling with sesame oil and sunflower oil was found to reduce plaque related gingivitis. Coconut oil is an easily available edible oil. It is unique because it contains predominantly medium chain fatty acids of which 45-50 percent is lauric acid. Lauric acid has proven anti inflammatory and antimicrobial effects. No studies have been done on the benefits of oil pulling using coconut oil to date. So a pilot study was planned to assess the effect of coconut oil pulling on plaque induced gingivitis. Materials and Methods: The aim of the study was to evaluate the effect of coconut oil pulling/oil swishing on plaque formation and plaque induced gingivitis. A prospective interventional study was carried out. 60 age matched adolescent boys and girls in the age-group of 16-18 years with plaque induced gingivitis were included in the study and oil pulling was included in their oral hygiene routine. The study period was 30 days. Plaque and gingival indices of the subjects were assessed at baseline days 1,7,15 and 30. The data was analyzed using paired t test. Results: A statistically significant decrease in the plaque and gingival indices was noticed from day 7 and the scores continued to decrease during the period of study. Conclusion: Oil pulling using coconut oil could be an effective adjuvant procedure in decreasing plaque formation and plaque induced gingivitis.

Peedikayil, Faizal C.; Sreenivasan, Prathima; Narayanan, Arun

2015-01-01

334

Enhanced Expression of Lp-PLA2 and Lysophosphatidylcholine in Symptomatic Carotid Atherosclerotic Plaques  

PubMed Central

Background and Purpose Circulating lipoprotein-associated phospholipase A2 (Lp-PLA2) has emerged as a novel biomarker for cardiovascular diseases. However, the correlation between the plaque expression of Lp-PLA2 and plaque oxidative stress, inflammation, and stability as well as the clinical presentation remains poorly defined, especially for cerebrovascular disease. Therefore, this study was performed to test the hypothesis that Lp-PLA2 expression is higher in symptomatic than in asymptomatic carotid plaques of patients undergoing carotid endarterectomy. Methods The expression of Lp-PLA2 in 167 carotid artery plaques was determined by immunoblotting and immunostaining. Plaque oxidative stress, inflammation, and stability were quantified by NAD(P)H oxidase p67phox and MMP-2 immunoblotting, oxidized LDL (oxLDL) immunoreactivity, macrophage and Sirius red collagen staining. Lysophosphatidylcholine 16:0 (lysoPC) concentration was measured in 55 plaques using liquid chromatography tandem mass spectrometry. Results Lp-PLA2 expression was significantly higher in plaques of symptomatic patients than asymptomatic patients (1.66±0.19 versus 1.14±0.10, P<0.05) and localized mainly to shoulder and necrotic lipid core areas in colocalization with oxLDL and macrophage content. Similarly, Lp-PLA2 expression was related to collagen content, which was lower in plaques from symptomatic patients than in plaques from asymptomatic patients (9.1±2.2 versus 18.5±1.7% of staining/field, P<0.001). LysoPC plaque concentration was significantly higher in plaques of symptomatic than asymptomatic patients (437.0±57.91 versus 228.84±37.00 mmol/L, P<0.05). Conclusions Symptomatic carotid artery plaques are characterized by increased levels of Lp-PLA2 and its product lysoPC in correlation with markers of tissue oxidative stress, inflammation, and instability. These findings strongly support a role for Lp-PLA2 in the pathophysiology and clinical presentation of cerebrovascular disease. PMID:18356547

Mannheim, Dallit; Herrmann, Joerg; Versari, Daniele; Gössl, Mario; Meyer, Fredric B.; McConnell, Joseph P.; Lerman, Lilach O.; Lerman, Amir

2015-01-01

335

Computer assisted treatment planning for sup 125 I ophthalmic plaque radiotherapy  

SciTech Connect

This paper describes a computer program for planning the treatment of ocular tumors with {sup 125}I plaques. The program permits the input of the tumor configuration into a model eye and facilitates the viewing of the relative geometry of the tumor and various eye structures in different perspectives. Custom-designed {sup 125}I plaques can be localized onto the globe, and dose distributions can be calculated and superimposed on the eye structures in any plane or on the inner eye surface. The program allows efficient evaluation of the plaque design in terms of radiation dose distribution relative to the tumor and critical structures.

Ling, C.C.; Chen, G.T.; Boothby, J.W.; Weaver, K.; Stuart, A.; Barnett, C.; Char, D.; Phillips, T.L. (Univ. of California, San Francisco (USA))

1989-08-01

336

Effects of fluorides on in vitro acid production by dental plaque.  

PubMed

A method that holds human dental plaque on a glass micro-electrode has been used to measure the pH depressions in plaque samples exposed to different concentrations of fluoride from sodium fluoride or sodium monofluorophosphate. Fluoride from both sources gave some inhibition of sucrose-induced acid formation at levels as low as 10 ppm and parallel results at other test concentrations of up to 200 ppm F. Repeated exposures of plaque to fluoride solutions did not interfere with its subsequent ability to ferment sucrose. PMID:3457824

Bibby, B G; Fu, J

1986-05-01

337

A Plaque Assay for Malignant Catarrhal Fever Virus and Virus Neutralizing Activity  

PubMed Central

A cell-free strain of malignant catarrhal fever virus which produced a readily recognizable cytopathic effect was obtained by serial passage of the virus in a rabbit kidney cell line. Plaque assay of the virus was more rapid and gave higher titres 11 days postinoculation than tube titration, but the latter advantage decreased with a longer incubation period. Plaques were clear with sharp edges and measured 0.5 to 2 mm in diameter after 15 days. A plaque neutralization test was developed and successfully employed for the titration of malignant catarrhal fever virus neutralizing activity in the sera and nasal secretions of blue wildebeest. PMID:7427840

Hazlett, D. T. G.

1980-01-01

338

Interleukin-17 (IL-17) Inhibitors in the Treatment of Plaque Psoriasis: A Review.  

PubMed

Acting on keratinocytes to produce antimicrobial peptides and chemokines, which in turn attract neutrophils and other inflammatory cells, interleukin-17 (IL-17) is believed to be a potent driver of plaque psoriasis. Its proinflammatory characteristics make IL-17 an attractive therapeutic target for addressing immune dysregulation. This review examines the role of IL-17 in the pathogenesis of plaque psoriasis and the potential implications of its inhibition. The efficacy and safety results from Phase 2 and 3 trials with monoclonal antibodies targeting IL-17RA (brodalumab), and IL-17A (ixekizumab and secukinumab) validate IL-17 as an effective therapeutic target for the treatment of plaque psoriasis. PMID:25807214

Gooderham, M; Posso-De Los Rios, C J; Rubio-Gomez, G A; Papp, K

2015-02-01

339

[Formation of iron plaque on root surface and its effect on plant nutrition and ecological environment].  

PubMed

This paper illustrated the conditions of iron plaque formation on root surface, the morphology, mineralogical composition and deposition site of the plaque, and its function as a Fe reservoir in supplying Fe nutrient and affecting the uptake of other nutrients such as phosphorus and zinc. The environmental and ecological role of the plaque in inhibiting the uptake and translocation of heavy metals such as Cu, Ni, Cd and As through absorption or co-precipitation was called external tolerance mechanism, while its competition with heavy metals for metabolically sensitive sites in plants was called internal tolerance mechanisms. These two mechanisms help plant survive in high acidic and low carbon environment. PMID:15362637

He, Chun'e; Liu, Xuejun; Zhang, Fusuo

2004-06-01

340

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

341

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

342

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

343

Comparative tolerability of systemic treatments for plaque-type psoriasis.  

PubMed

Psoriasis is a chronic, debilitating skin condition that affects millions of people and is attributed to both genetic and environmental factors. Topical therapy is generally considered to be the first-line treatment of psoriasis. However, many patients do not respond to topical therapy or have disease so extensive that topical therapy is not practical. For these patients, systemic therapy is indicated. Presently, there are four available systemic treatments, psoralen with ultraviolet A (PUVA), methotrexate, oral retinoids (acitretin), and cyclosporin. Unfortunately, all of these treatments have significant potential adverse effects. PUVA may acutely cause nausea, pruritus and sunburn. More chronic and concerning is the development of PUVA lentigines, ocular complications and skin cancer. Non-melanoma skin cancer has been directly linked to PUVA; however, the association with melonoma is more elusive. Methotrexate use most notably carries the risk of hepatic fibrosis and cirrhosis, which is not always evident on liver function tests. Other more rare, but potentially life-threatening adverse effects include pancytopenia, lymphoproliferative disorders and acute pneumonitis. The addition of folic acid may help to reduce the risk of increasing liver enzymes and haematological toxicity seen in those taking methotrexate. Both methotrexate and oral retinoids are teratogenic and should never be used in pregnancy. Oral retinoids are probably the least effective available systemic medication for the treatment of plaque psoriasis. The effects are improved with the addition of other systemic therapies. Acitretin has replaced the formerly used etretinate primarily because of the significantly shorter half-life. The adverse effects are generally mild and reversible, making the drug fairly safe for long-term use. The most commonly seen adverse effects include elevated serum lipids, generalised xerosis and alopecia. Bony abnormalities, while somewhat controversial, have also been described and include diffuse idiopathic skeletal hyperostosis, skeletal calcifications and osteoporosis. Cyclosporin is the most recently approved systemic medication for plaque psoriasis. The nephrotoxicity associated with the use of cyclosporin can be minimised when used in lower doses and for a limited duration. Hypertension is usually mild and can be seen in up to about one-third of patients receiving long-term therapy. Cutaneous and internal malignancies have also been reported with cyclosporin and tend to be correlated with duration of treatment. In this review, we will examine the potential adverse effects with these US Food and Drug Administration-approved treatments in adults, with specific emphasis on the controversies that surround long-term therapy with these agents and their cumulative adverse effects. PMID:12381213

McClure, Stacy L; Valentine, Jayme; Gordon, Kenneth B

2002-01-01

344

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

PubMed Central

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

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

1977-01-01

345

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

E-print Network

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

Bouma, Brett E.

346

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

PubMed

Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcóllar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed 'root+plaque' material in excess of 1000 mg kg(-1), and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcóllar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque. PMID:19062145

Taggart, M A; Mateo, R; Charnock, J M; Bahrami, F; Green, A J; Meharg, A A

2009-03-01

347

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

348

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

349

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.

350

A Threestepped Coordinated Level Set Segmentation Method for Identifying Atherosclerotic Plaques on MR-Images  

E-print Network

of the body ­ including the heart and the vessels - with high spatial resolution (typical values for in, such as the aorta and the carotid arteries with state of the art MR scanners and to characterize plaque components

Ehrhardt, Matthias

351

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.

352

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

353

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

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

354

A case of aseptic pleuropericarditis in a patient with chronic plaque psoriasis under methotrexate therapy  

E-print Network

with chronic plaque psoriasis under methotrexate therapypsoriasis since the age of 30, when he began oral methotrexateMethotrexate is frequently used worldwide for the treatment of cutaneous and arthropatic psoriasis.

2010-01-01

355

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

PubMed Central

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

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

2011-01-01

356

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

PubMed Central

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

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

2009-01-01

357

Histotopochemical Determination of Metabolic Activity of Carbohydrate Metabolism in Plaque from Sound and Carious Enamel  

Microsoft Academic Search

The tetrazolium technique was applied in tissue sections from sound and carious enamel plaque on human teeth to represent the histotopochemical distribution of activity for numerous enzymes of the Embden-Meyerhof pathway, the pentosephosphate and citrate cycle, and the glycerophosphate cycle. GAPDH, LDH, G6PDH, ME, MDH, SDH, and NAD-IDH were found in all samples from sound enamel plaque; NADP-IDH appeared in

U. A. Garlichs; H. Brandau; K. Bössmann

1974-01-01

358

Prevalence of periodontal pathogens in coronary atherosclerotic plaque of patients undergoing coronary artery bypass graft surgery  

Microsoft Academic Search

Background  Chronic bacterial infections have been associated with an increased risk for atherosclerosis and coronary artery disease.\\u000a The ability of oral pathogens to colonize in coronary atheromatous plaque is well known. The aim of our study was to detect\\u000a the presence of four common periodontal pathogens in coronary plaques. We detected the presence of 16S rRNA of Treponema denticola, Eikenella Corrodens,

Jaideep Mahendra; Little Mahendra; V. M. Kurian; K. Jaishankar; R. Mythilli

2009-01-01

359

In Vivo Phage Display Selection Yields Atherosclerotic Plaque Targeted Peptides for Imaging  

Microsoft Academic Search

Purpose  Atherosclerosis is a leading cause of morbidity and mortality in the Western world, yet specific imaging agents to detect and map inflammatory plaques are still lacking.Procedures  We used in vivo phage display to interrogate early atherosclerotic lesions present in ApoE?\\/? mice with the goal of identifying plaque-associated endothelial cell internalized affinity ligands.Results  We identified 30 phage families with some of these families

Kimberly A. Kelly; Matthias Nahrendorf; Amy M. Yu; Fred Reynolds; Ralph Weissleder

2006-01-01

360

Phage Display Identification of CD100 in Human Atherosclerotic Plaque Macrophages and Foam Cells  

PubMed Central

Atherosclerosis is a complex disease in which vessels develop plaques comprising dysfunctional endothelium, monocyte derived lipid laden foam cells and activated lymphocytes. Considering that humans and animal models of the disease develop quite distinct plaques, we used human plaques to search for proteins that could be used as markers of human atheromas. Phage display peptide libraries were probed to fresh human carotid plaques, and a bound phage homologous to plexin B1, a high affinity receptor for CD100, was identified. CD100 is a member of the semaphorin family expressed by most hematopoietic cells and particularly by activated T cells. CD100 expression was analyzed in human plaques and normal samples. CD100 mRNA and protein were analyzed in cultured monocytes, macrophages and foam cells. The effects of CD100 in oxLDL-induced foam cell formation and in CD36 mRNA abundance were evaluated. Human atherosclerotic plaques showed strong labeling of CD100/SEMA4D. CD100 expression was further demonstrated in peripheral blood monocytes and in in vitro differentiated macrophages and foam cells, with diminished CD100 transcript along the differentiation of these cells. Incubation of macrophages with CD100 led to a reduction in oxLDL-induced foam cell formation probably through a decrease of CD36 expression, suggesting for the first time an atheroprotective role for CD100 in the human disease. Given its differential expression in the numerous foam cells and macrophages of the plaques and its capacity to decrease oxLDL engulfment by macrophages we propose that CD100 may have a role in atherosclerotic plaque development, and may possibly be employed in targeted treatments of these atheromas. PMID:24098722

Luque, Maria Carolina Aquino; Gutierrez, Paulo Sampaio; Debbas, Victor; Martins, Waleska Kerllen; Puech-Leao, Pedro; Porto, Georgia; Coelho, Verônica; Boumsell, Laurence; Kalil, Jorge; Stolf, Beatriz

2013-01-01

361

Soil factors influencing ferric hydroxide plaque formation on roots of Typha latifolia L  

Microsoft Academic Search

The amount of ferric hydroxide plaque deposited onTypha latifolia roots varied between wetlands submerged throughout the growing season. Plaque formation was positively correlated with extractable\\u000a iron in the substrate and pH, and negatively correlated with the percent organic matter and percent inorganic carbonates in\\u000a the soil. All the above correlations were significant but weak, and in a stepwise regression analysis

S. M. Macfie; A. A. Crowder

1987-01-01

362

View of the plaque to be left on the moon by the Apollo 17 astronauts  

NASA Technical Reports Server (NTRS)

View of the plaque to be left at the Taurus-Littrow lunar landing site by the Apollo 17 astronauts. The commemorative plaque is made of stainless steel measuring nine by seven by five-eighths inches and one-sixteenth inch thick. It is attached to the ladder on the landing gear strut on the descent stage of the Apollo 17 Lunar Module 'Challenger'.

1972-01-01

363

Relationship of periodontal clinical parameters with bacterial composition in human dental plaque.  

PubMed

More than 600 bacterial species have been identified in the oral cavity, but only a limited number of species show a strong association with periodontitis. The purpose of the present study was to provide a comprehensive outline of the microbiota in dental plaque related to periodontal status. Dental plaque from 90 subjects was sampled, and the subjects were clustered based on bacterial composition using the terminal restriction fragment length polymorphism of 16S rRNA genes. Here, we evaluated (1) periodontal clinical parameters between clusters; (2) the correlation of subgingival bacterial composition with supragingival bacterial composition; and (3) the association between bacterial interspecies in dental plaque using a graphical Gaussian model. Cluster 1 (C1) having high prevalence of pathogenic bacteria in subgingival plaque showed increasing values of the parameters. The values of the parameters in Cluster 2a (C2a) having high prevalence of non-pathogenic bacteria were markedly lower than those in C1. A cluster having low prevalence of non-pathogenic bacteria in supragingival plaque showed increasing values of the parameters. The bacterial patterns between subgingival plaque and supragingival plaque were significantly correlated. Chief pathogens, such as Porphyromonas gingivalis, formed a network with other pathogenic species in C1, whereas a network of non-pathogenic species, such as Rothia sp. and Lautropia sp., tended to compete with a network of pathogenic species in C2a. Periodontal status relates to non-pathogenic species as well as to pathogenic species, suggesting that the bacterial interspecies connection affects dental plaque virulence. PMID:23539062

Fujinaka, Hidetake; Takeshita, Toru; Sato, Hirayuki; Yamamoto, Tetsuji; Nakamura, Junji; Hase, Tadashi; Yamashita, Yoshihisa

2013-06-01

364

Anschutz Library receives plaque recognizing outstanding efforts in energy conservation and sustainability  

E-print Network

. The Student Environmental Advisory Board, a KU student organization, spearheaded a Student Senate initiative to reduce dependence on unsustainable energy in 2007. The initiative uses student fees to purchase wind power credits from one of Westar Energy... Articles, Books,… Friends & Benefactors Suggestions Anschutz Library receives plaque recognizing outstanding efforts in energy conservation and sustainabil i ty On Friday, August 14, Chevron Energy Solutions (CES) will present a plaque to Anschutz Library...

2009-01-01

365

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

Microsoft Academic Search

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

L. St-Cyr; A. A. Crowder

1989-01-01

366

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

367

InVivoRadiofrequency-Based Ultrasonic Tissue Characterization oftheAtherosclerotic Plaque  

Microsoft Academic Search

Background andPurpose: Theultrasonic image can offer unique information on thecomposition of atherosclerotic plaque, ie,therelative content oflipids, fibrous tissue, andcalcific deposits. Todate, however, theechographic assessment ofplaque structure isbased on a subjective, qualitative evaluation ofthebidimensional images. Weevaluated thefeasibility andaccuracyofassessing, invivo, theacoustic properties ofarterial carotid plaques bymeans ofa suitably modified echographic apparatus allowing direct accesstotheradiofrequency signal. Methods: In15patients undergoing carotid thromboendarterectomy, theultrasonic findings

Michelangelo PioUrbani; Eugenio Picano; Giuliano Parenti; Alessandro Mazzarisi; Leonardo Fiori; Luigi Landini

368

Effect of blood on lethal photosensitization of bacteria in subgingival plaque from patients with chronic periodontitis  

Microsoft Academic Search

The purpose of this study was to determine whether bacteria in subgingival plaque samples from patients with chronic periodontitis\\u000a could be sensitized to killing by low-power laser light in the presence of blood. Toluidine blue O (45 ?g ml?1) was added to the plaque samples which were then exposed to light from a 7.3 mW HeNe laser for 30 or

M. Wilson; S. Sarkar; J. S. Bulman

1993-01-01

369

Pathology of Vulnerability Caused by High-Risk (Vulnerable) Arteries and Plaques  

Microsoft Academic Search

\\u000a Atherosclerosis is a slowly progressing systemic (multifocal) arterial disease with focal manifestations caused by one or\\u000a relatively few stenotic and\\/or thrombosis-prone (vulnerable) plaques. The coronary arteries, carotid arteries, ilio-femoral\\u000a arteries, and aorta are especially susceptible to atherosclerosis. The most devastating consequences of atherosclerosis, such\\u000a as heart attack and stroke, are usually caused by thrombosis precipitated by plaque rupture. Although the

Troels Thim; Mette Kallestrup Hagensen; Jacob Fog Bentzon; Erling Falk

370

Treatment with Angiotensin-(1-7) reduces inflammation in carotid atherosclerotic plaques.  

PubMed

Angiotensin (Ang)-(1-7), acting through the receptor Mas, has atheroprotective effects; however, its role on plaque vulnerability has been poorly studied. Here, we investigated the expression of the renin-angiotensin system (RAS) components in stable and unstable human carotid plaques. In addition, we evaluated the effects of the chronic treatment with an oral formulation of Ang-(1-7) in a mouse model of shear stress-determined carotid atherosclerotic plaque. Upstream and downstream regions of internal carotid plaques were obtained from a recently published cohort of patients asymptomatic or symptomatic for ischaemic stroke. Angiotensinogen and renin genes were strongly expressed in the entire cohort, indicating an intense intraplaque modulation of the RAS. Intraplaque expression of the Mas receptor mRNA was increased in the downstream portion of asymptomatic patients as compared to corresponding region in symptomatic patients. Conversely, AT1 receptor gene expression was not modified between asymptomatic and symptomatic patients. Treatment with Ang-(1-7) in ApoE-/- mice was associated with increased intraplaque collagen content in the aortic root and low shear stress-induced carotid plaques, and a decreased MMP-9 content and neutrophil and macrophage infiltration. These beneficial effects were not observed in the oscillatory shear stress-induced plaque. In vitro incubation with Ang-(1-7) did not affect ICAM-1 expression and apoptosis on cultured endothelial cells. In conclusion, Mas receptor is up regulated in the downstream portions of human stable carotid plaques as compared to unstable lesions. Treatment with the oral formulation of Ang-(1-7) enhances a more stable phenotype in atherosclerotic plaques, depending on the local pattern of shear stress forces. PMID:24499778

Fraga-Silva, Rodrigo A; Savergnini, Silvia Q; Montecucco, Fabrizio; Nencioni, Alessio; Caffa, Irene; Soncini, Debora; Costa-Fraga, Fabiana P; De Sousa, Frederico B; Sinisterra, Ruben D; Capettini, Luciano A S; Lenglet, Sébastien; Galan, Katia; Pelli, Graziano; Bertolotto, Maria; Pende, Aldo; Spinella, Giovanni; Pane, Bianca; Dallegri, Franco; Palombo, Domenico; Mach, François; Stergiopulos, Nikolaos; Santos, Robson A S; da Silva, Rafaela F

2014-04-01

371

Development of a plaque assay for a cytopathic, rapidly replicating isolate of hepatitis A virus.  

PubMed

Most hepatitis A virus (HAV) replication in cell culture has been reported to be nonlytic and relatively slow. A rapidly replicating isolate of strain HM-175 from persistently infected, serially passed cell cultures (pHM-175) was found to induce a cytopathic effect. This observation allowed the development of a classic plaque assay for pHM-175 in FRhK-4 cells. The plaques were neutralized by polyclonal and monoclonal antisera to HAV. PMID:3035079

Cromeans, T; Sobsey, M D; Fields, H A

1987-05-01

372

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

373

Quantification of epidermal cell populations in the centre and margin of stable psoriatic plaques  

Microsoft Academic Search

\\u000a Abstract The histological picture of psoriasis has been studied extensively. Several authors have investigated the differences between\\u000a the centre and the margin of spreading plaques, because the margin is of great pathogenic interest as lesions enlarge by centrifugal\\u000a expansion. However, little is known about the differences between the centre and the margin of stable plaques. In the present\\u000a study we

J. M. Mommers; M. M. van Rossum; C. A. E. M. van Hooijdonk; P. E. J. van Erp; P. C. M. van de Kerkhof

1999-01-01

374

Multiple Atherosclerotic Plaque Rupture in Acute Coronary Syndrome: A Three-Vessel Intravascular Ultrasound Study  

Microsoft Academic Search

Background—To test the hypothesis of general atherosclerotic plaque destabilization during acute coronary syndrome (ACS), the present study sought to analyze the 3 coronary arteries by systematic intravascular ultrasound scan (IVUS). Methods and Results—Seventy-two arteries were explored in 24 patients referred for percutaneous coronary intervention after a first ACS with troponin I elevation. Fifty plaque ruptures (mean, 2.08 per patient; range,

G. Rioufol; G. Finet; I. Ginon; X. André-Fouët; R. Rossi; E. Vialle; E. Desjoyaux; G. Convert; J. F. Huret; A. Tabib

2002-01-01

375

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

376

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

PubMed Central

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

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

2014-01-01

377

Texture characterization of carotid atherosclerotic plaque from B-mode ultrasound using gabor filters.  

PubMed

Texture analysis of B-mode ultrasound images of carotid atheromatous plaque can be valuable for the accurate diagnosis of atherosclerosis. In this paper, Gabor filters were used to characterize the texture of carotid artery atherosclerotic tissue. B-mode ultrasound images of 10 symptomatic and 9 asymptomatic plaques were interrogated. A total of 40 texture features were estimated for each plaque. The bootstrap method was used to compare the mean values of the texture features extracted from the two groups. After bootstrapping, the mean value and the standard deviation of the energy estimated using the Gabor filters was found to be significantly different between symptomatic and asymptomatic plaques in the first scale of analysis and for all orientations. In addition, a number of texture features that correspond to larger resolution scales were found to be significantly different between the two types of plaques. It is concluded that Gabor-filter-based texture analysis in combination with a powerful statistical technique, such as bootstrapping, may provide valuable information about the plaque tissue type. PMID:19964937

Stoitsis, John; Golemati, Spyretta; Tsiaparas, Nikolaos; Nikita, Konstantina S

2009-01-01

378

Prevalence and severity of plaque-induced gingivitis in a Saudi adult population  

PubMed Central

Objectives: To evaluate the prevalence and severity of plaque-induced gingivitis among a Saudi adult population in Riyadh region. Methods: Three hundred and eighty-five eligible participants in this cross-sectional study were recruited from routine dental patients attending the oral diagnosis clinic at Al-Farabi College in Riyadh, Saudi Arabia from June 2013 to December 2013. A clinical examination was performed by 2 dentists to measure the gingival and plaque indices of Löe and Silness for each participant. Results: The prevalence of gingivitis was 100% among adult subjects aged between 18-40 years old. Moreover, the mean gingival index was 1.68±0.31, which indicates a moderate gingival inflammation. In fact, males showed more severe signs of gingival inflammation compared with females (p=0.001). In addition, the mean plaque index was 0.875±0.49, which indicates a good plaque status of the participants. Interestingly, the age was not related either to the gingival inflammation (p=0.13), or to the amount of plaque accumulation (p=0.17). However, males were more affected than females (p=0.005). Conclusion: The results of this study show that plaque accumulation is strongly associated with high prevalence of moderate to severe gingivitis among Saudi subjects. PMID:25399215

Idrees, Majdy M.; Azzeghaiby, Saleh N.; Hammad, Mohammad M.; Kujan, Omar B.

2014-01-01

379

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

PubMed Central

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

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

2014-01-01

380

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

PubMed Central

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

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

2008-01-01

381

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

382

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

SciTech Connect

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

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

1983-01-01

383

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

PubMed Central

This study was to investigate the hemodynamic effect of simulated plaques in left coronary artery models, which were generated from a sample patient's data. Plaques were simulated and placed at the left main stem and the left anterior descending (LAD) to produce at least 60% coronary stenosis. Computational fluid dynamics analysis was performed to simulate realistic physiological conditions that reflect the in vivo cardiac hemodynamics, and comparison of wall shear stress (WSS) between Newtonian and non-Newtonian fluid models was performed. The pressure gradient (PSG) and flow velocities in the left coronary artery were measured and compared in the left coronary models with and without presence of plaques during cardiac cycle. Our results showed that the highest PSG was observed in stenotic regions caused by the plaques. Low flow velocity areas were found at postplaque locations in the left circumflex, LAD, and bifurcation. WSS at the stenotic locations was similar between the non-Newtonian and Newtonian models although some more details were observed with non-Newtonian model. There is a direct correlation between coronary plaques and subsequent hemodynamic changes, based on the simulation of plaques in the realistic coronary models. PMID:22400051

Chaichana, Thanapong; Sun, Zhonghua; Jewkes, James

2012-01-01

384

Inhibition of dental plaque acid production by the salivary lactoperoxidase antimicrobial system.  

PubMed

Resting human whole saliva inhibited acid production by glucose-stimulated, homologous plaque. The degree of inhibition of plaque acid production correlated positively with the concentration of hypothiocyanite (OSCN-) ions in saliva. Supplementation of saliva with an appropriate combination of thiocyanate and hydrogen peroxide resulted in a significant increase in the concentration of OSCN- ions and in more effective inhibition of plaque acid production. In most cases, the inhibition was complete when the supplements were added directly to saliva-plaque mixtures. Acid production resumed when the inhibitory effect of OSCN- was reversed by addition of thiols. Among the oral defense factors, the salivary lactoperoxidase system seems to play an important role by producing highly reactive antibacterial products (including OSCN-) which can regulate bacterial metabolism in the human mouth. The concentration of OSCN- in normal human whole saliva seems to be just below the threshold level required for plaque inhibition. Therefore, enhancement of this system in vivo may be effective in the regulation of plaque acid production. PMID:7298182

Tenovuo, J; Mansson-Rahemtulla, B; Pruitt, K M; Arnold, R

1981-10-01

385

Inhibition of dental plaque acid production by the salivary lactoperoxidase antimicrobial system.  

PubMed Central

Resting human whole saliva inhibited acid production by glucose-stimulated, homologous plaque. The degree of inhibition of plaque acid production correlated positively with the concentration of hypothiocyanite (OSCN-) ions in saliva. Supplementation of saliva with an appropriate combination of thiocyanate and hydrogen peroxide resulted in a significant increase in the concentration of OSCN- ions and in more effective inhibition of plaque acid production. In most cases, the inhibition was complete when the supplements were added directly to saliva-plaque mixtures. Acid production resumed when the inhibitory effect of OSCN- was reversed by addition of thiols. Among the oral defense factors, the salivary lactoperoxidase system seems to play an important role by producing highly reactive antibacterial products (including OSCN-) which can regulate bacterial metabolism in the human mouth. The concentration of OSCN- in normal human whole saliva seems to be just below the threshold level required for plaque inhibition. Therefore, enhancement of this system in vivo may be effective in the regulation of plaque acid production. PMID:7298182

Tenovuo, J; Mansson-Rahemtulla, B; Pruitt, K M; Arnold, R

1981-01-01

386

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

387

Relationship between ultrasonic attenuation, size and axial strain parameters for ex vivo atherosclerotic carotid plaque.  

PubMed

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

Shi, Hairong; Varghese, Tomy; Dempsey, Robert J; Salamat, Mohammed S; Zagzebski, James A

2008-10-01

388

Effects of exogenous gibberellic acid3 on iron and manganese plaque amounts and iron and manganese uptake in rice.  

PubMed

Gibberellins (GA) regulate various components of plant development. Iron and Mn plaque result from oxiding and hydroxiding Fe and Mn, respectively, on the roots of aquatic plant species such as rice (Oryza sativa L.). In this study, we found that exogenous gibberellic acid3 (GA3) spray decreased Fe plaque, but increased Mn plaque, with applications of Kimura B nutrient solution. Similar effects from GA3, leading to reduced Fe plaque and increased Mn plaque, were also found by scanning electron microscopy and energy dispersive X-ray spectrometric microanalysis. Reduced Fe plaque was observed after applying GA3 to the groups containing added Fe2+ (17 and 42 mg•L(-1)) and an increasing trend was detected in Mn plaques of the Mn2+ (34 and 84 mg•L(-1)) added treatments. In contrast, an inhibitor of GA3, uniconazole, reversed the effects of GA3. The uptake of Fe or Mn in rice plants was enhanced after GA3 application and Fe or Mn plaque production. Strong synergetic effects of GA3 application on Fe plaque production were detected. However, no synergetic effects on Mn plaque production were detected. PMID:25710173

Guo, Yue; Zhu, Changhua; Gan, Lijun; Ng, Denny; Xia, Kai

2015-01-01

389

Effects of Exogenous Gibberellic Acid3 on Iron and Manganese Plaque Amounts and Iron and Manganese Uptake in Rice  

PubMed Central

Gibberellins (GA) regulate various components of plant development. Iron and Mn plaque result from oxiding and hydroxiding Fe and Mn, respectively, on the roots of aquatic plant species such as rice (Oryza sativa L.). In this study, we found that exogenous gibberellic acid3 (GA3) spray decreased Fe plaque, but increased Mn plaque, with applications of Kimura B nutrient solution. Similar effects from GA3, leading to reduced Fe plaque and increased Mn plaque, were also found by scanning electron microscopy and energy dispersive X-ray spectrometric microanalysis. Reduced Fe plaque was observed after applying GA3 to the groups containing added Fe2+ (17 and 42 mg•L-1) and an increasing trend was detected in Mn plaques of the Mn2+ (34 and 84 mg•L-1) added treatments. In contrast, an inhibitor of GA3, uniconazole, reversed the effects of GA3. The uptake of Fe or Mn in rice plants was enhanced after GA3 application and Fe or Mn plaque production. Strong synergetic effects of GA3 application on Fe plaque production were detected. However, no synergetic effects on Mn plaque production were detected. PMID:25710173

Guo, Yue; Zhu, Changhua; Gan, Lijun; Ng, Denny; Xia, Kai

2015-01-01

390

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

391

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

PubMed Central

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 FDG-PET imaging. However, cardiac and respiratory motion of the heart makes PET detection of coronary plaque very challenging. Fat surrounding coronary arteries allow 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 patient 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 (PBC) 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

2014-01-01

392

Correlation of Cognitive Function with Ultrasound Strain Indices in Carotid Plaque  

PubMed Central

Instability in carotid vulnerable plaque can generate cerebral microemboli, that 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 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 subjects 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 utilized 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 the 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 the maximum lateral strain was higher for symptomatic patients (r=?0.650, p=0.006) than that for asymptomatic patients (r=?0.115, p=0.803). On the other hand correlation for maximum axial strain averaged over the entire plaque region was significantly higher for asymptomatic patients (r=?0.817, p=0.016) than that 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 with cognitive impairment. PMID:24120415

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

2013-01-01

393

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

394

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

395

Effect of Fluoride and Chlorhexidine Digluconate Mouthrinses on Plaque Biofilms  

PubMed Central

Objective : To develop a model in which to investigate the architecture of plaque biofilms formed on enamel surfaces in vivo and to compare the effects of anti-microbial agents of relevance for caries on biofilm vitality. Materials and Methodology : Enamel discs mounted on healing abutments in the pre-molar region were worn by three subjects for 7 days. Control discs were removed before subjects rinsed with 0.1% chlorhexidine digluconate (CHX) or 0.2% sodium fluoride (NaF) for 1 minute. Biofilms were stained with Baclight Live/Dead and z-stacks of images created using confocal scanning laser micoscopy. The levels of vital and dead/damaged bacteria in the biofilms, assessed as the proportion of green and red pixels respectively, were analysed using ImageTrak® software. Results : The subjects showed individual differences in biofilm architecture. The thickness of the biofilms varied from 28-96µm although cell density was always the greatest in the middle layers. In control biofilms, the overall levels of vitality were high (71-98%) especially in the area closest to the enamel interface. Rinsing with either CHX or NaF caused a similar reduction in overall vitality. CHX exerted an effect throughout the biofilm, particularly on the surface of cell clusters whereas NaF caused cell damage/death mainly in the middle to lower biofilm layers. Conclusion : We describe a model that allows the formation of mature, undisturbed oral biofilms on human enamel surfaces in vivo and show that CHX and NaF have a similar effect on overall vitality but differ in their sites of action.

Rabe, Per; Twetman, Svante; Kinnby, Bertil; Svensäter, Gunnel; Davies, Julia R

2015-01-01

396

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

SciTech Connect

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

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

2012-09-01

397

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

398

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

399

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

NASA Astrophysics Data System (ADS)

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

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

2006-02-01

400

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

PubMed Central

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

2011-01-01

401

Effects of tongue cleaning on bacterial flora in tongue coating and dental plaque: a crossover study  

PubMed Central

Background The effects of tongue cleaning on reconstruction of bacterial flora in dental plaque and tongue coating itself are obscure. We assessed changes in the amounts of total bacteria as well as Fusobacterium nucleatum in tongue coating and dental plaque specimens obtained with and without tongue cleaning. Methods We conducted a randomized examiner-blind crossover study using 30 volunteers (average 23.7 ± 3.2 years old) without periodontitis. After dividing randomly into 2 groups, 1 group was instructed to clean the tongue, while the other did not. On days 1 (baseline), 3, and 10, tongue coating and dental plaque samples were collected after recording tongue coating score (Winkel tongue coating index: WTCI). After a washout period of 3 weeks, the same examinations were performed with the subjects allocated to the alternate group. Genomic DNA was purified from the samples and applied to SYBR® Green-based real-time PCR to quantify the amounts of total bacteria and F. nucleatum. Results After 3 days, the WTCI score recovered to baseline, though the amount of total bacteria in tongue coating was significantly lower as compared to the baseline. In plaque samples, the bacterial amounts on day 3 and 10 were significantly lower than the baseline with and without tongue cleaning. Principal component analysis showed that variations of bacterial amounts in the tongue coating and dental plaque samples were independent from each other. Furthermore, we found a strong association between amounts of total bacteria and F. nucleatum in specimens both. Conclusions Tongue cleaning reduced the amount of bacteria in tongue coating. However, the cleaning had no obvious contribution to inhibit dental plaque formation. Furthermore, recovery of the total bacterial amount induced an increase in F. nucleatum in both tongue coating and dental plaque. Thus, it is recommended that tongue cleaning and tooth brushing should both be performed for promoting oral health. PMID:24423407

2014-01-01

402

Segmental coronary endothelial dysfunction in patients with minimal atherosclerosis is associated with necrotic core plaques  

PubMed Central

Background/objective Endothelial dysfunction and atherosclerosis are systemic disorders, but are often characterised by segmental involvement and complications. A potential mechanism for local involvement early in the disease process may be related to plaque composition. This study was designed to test the hypothesis that in patients with minimal coronary atherosclerosis, coronary artery segments with abnormal endothelial function have specific plaque characteristics. Methods Intravascular ultrasound (IVUS) images were obtained from 30 patients who underwent coronary endothelial function assessment. Spectral analysis of the IVUS radiofrequency data was used for assessment of plaque composition. IVUS findings of the coronary sections were compared according to the corresponding endothelial response to acetylcholine. Results Sections with a decrease epicardial coronary arterial diameter in response to acetylcholine had smaller baseline lumen (7.5 (2.4) mm2 vs 8.8 (3.3) mm2, p = 0.006) but larger plaque burden (37.1% (9.4%) vs 31% (7%), p = 0.003) than sections with normal endothelial response. Sections with endothelial dysfunction had larger necrotic core plaques: 0.13 (0.03–0.33) mm2 vs 0.0 (0.0–0.07), p<0.001 and more dense calcium: 0.03 (IQR 0.0–0.13) mm2 vs 0.0 (0.0–0.10) mm2, p<0.01), than those with normal endothelial response. Only necrotic core area was associated with endothelial dysfunction (p<0.001) after adjusting for other measures. Conclusions This study suggests that local coronary endothelial dysfunction in patients with minimal coronary atherosclerosis is associated with plaque characteristics that are typical of vulnerable plaques. PMID:19497916

Lavi, S; Bae, J-H; Rihal, C S; Prasad, A; Barsness, G W; Lennon, R J; Holmes, D R; Lerman, A

2015-01-01

403

Atorvastatin Improves Plaque Stability in ApoE-Knockout Mice by Regulating Chemokines and Chemokine Receptors  

PubMed Central

It is well documented that statins protect atherosclerotic patients from inflammatory changes and plaque instability in coronary arteries. However, the underlying mechanisms are not fully understood. Using a previously established mouse model for vulnerable atherosclerotic plaque, we investigated the effect of atorvastatin (10 mg/kg/day) on plaque morphology. Atorvastatin did not lower plasma total cholesterol levels or affect plaque progression at this dosage; however, vulnerable plaque numbers were significantly reduced in the atorvastatin-treated group compared to control. Detailed examinations revealed that atorvastatin significantly decreased macrophage infiltration and subendothelial lipid deposition, reduced intimal collagen content, and elevated collagenase activity and expression of matrix metalloproteinases (MMPs). Because vascular inflammation is largely driven by changes in monocyte/macrophage numbers in the vessel wall, we speculated that the anti-inflammatory effect of atorvastatin may partially result from decreased monocyte recruitment to the endothelium. Further experiments showed that atorvastatin downregulated expression of the chemokines monocyte chemoattractant protein (MCP)-1, chemokine (C-X3-C motif) ligand 1 (CX3CL1) and their receptors CCR2 and, CX3CR1, which are mainly responsible for monocyte recruitment. In addition, levels of the plasma inflammatory markers C-reactive protein (CRP) and tumor necrosis factor (TNF)-? were also significantly decrease in atorvastatin-treated mice. Collectively, our results demonstrate that atorvastatin can improve plaque stability in mice independent of plasma cholesterol levels. Given the profound inhibition of macrophage infiltration into atherosclerotic plaques, we propose that statins may partly exert protective effects by modulating levels of chemokines and their receptors. These findings elucidate yet another atheroprotective mechanism of statins. PMID:24816562

Hu, Liuhua; Jin, Shuxuan; Yu, Ying; Cai, Zhaohua; Shao, Qin; Shen, Jieyan; Yi, Jing; Xiao, Hua; Shen, Linghong; He, Ben

2014-01-01

404

Low Elastin Content of Carotid Plaques Is Associated with Increased Risk of Ipsilateral Stroke  

PubMed Central

Objectives Atherosclerotic plaques with a low content of connective tissue proteins are believed to have an increased risk of rupture and to give rise to clinical events. The aim of the present study was to investigate if the content of elastin, collagen and of the matrix metalloproteinase (MMP) ?1, ?3, ?9 and ?12 in plaques removed at surgery can be associated with the occurrence of ipsilateral symptoms. Methods The atherosclerotic plaques of 221 patients undergoing carotid endarterectomy were analyzed and their composition was related to the incidence of preoperative, intraoperative and postoperative neurological events. Results Elastin, collagen and MMP-12 contents were lower in males and diabetic patients. Elastin (P .010), MMP-3 (P .008) and MMP-9 (P < .0001) were lower, while MMP-1 (P .004) and MMP-9 (P .002) were higher in plaques of patients with preoperative symptoms, even after correction for the time between the occurrence of symptoms and surgery. Elastin and MMP-12 decreased (r = ?0.17, P .009 and r = ?.288, P <.0001 respectively) while MMP-1 (r = 0.17, P .012) and MMP-9 (r = .21 P <.0001) increased with age. After a mean follow-up time of 39.6 ± 16.6 months, 7.7% of patients had suffered one or multiple ipsilateral neurological events. Patients with plaque elastin levels lower than the median (52 mg/g) had increased post-operative incidence of ipsilateral stroke (P for trend 0.009 using Log Rank Chi-square test). This finding was confirmed when controlling for age, gender, hypertension, diabetes, smoking, pre-operative symptoms and statin usage in a Cox Proportional Hazard model (hazard ratio 7.38, 95% C.I. 1.50–36.31). Conclusions These observations support the concept that elastin may be important for plaque stability, and suggest that a low plaque content of elastin is associated with a higher risk for ipsilateral stroke. PMID:25803692

Asciutto, Giuseppe; Dias, Nuno V; Edsfeldt, Andreas; Nitulescu, Mihaela; Persson, Ana; Nilsson, Marie; Dunér, Pontus; Nilsson, Jan; Gonçalves, Isabel

2015-01-01

405

Role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism.  

PubMed

Our aim was to investigate the role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism. Coronary angiography and intravascular ultrasound (IVUS) were performed in 60 stable angina pectoris (SAP) patients and 60 unstable angina pectoris (UAP) patients. The chemotactic activity of monocytes in the 2 groups of patients was examined in Transwell chambers. High-sensitivity C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1), regulated on activation in normal T-cell expressed and secreted (RANTES), and fractalkine in serum were examined with ELISA kits, and expression of MCP-1, RANTES, and fractalkine mRNA was examined with real-time PCR. In the SAP group, 92 plaques were detected with IVUS. In the UAP group, 96 plaques were detected with IVUS. The plaques in the UAP group were mainly lipid 51.04% (49/96) and the plaques in the SAP group were mainly fibrous 52.17% (48/92). Compared with the SAP group, the plaque burden and vascular remodeling index in the UAP group were significantly greater than in the SAP group (P<0.01). Chemotactic activity and the number of mobile monocytes in the UAP group were significantly greater than in the SAP group (P<0.01). Concentrations of hs-CRP, MCP-1, RANTES, and fractalkine in the serum of the UAP group were significantly higher than in the serum of the SAP group (P<0.05 or P<0.01), and expression of MCP-1, RANTES, and fractalkine mRNA was significantly higher than in the SAP group (P<0.05). MCP-1, RANTES, and fractalkine probably promote instability of coronary atherosclerotic plaque. PMID:25424368

Zhong, Z X; Li, B; Li, C R; Zhang, Q F; Liu, Z D; Zhang, P F; Gu, X F; Luo, H; Li, M J; Luo, H S; Ye, G H; Wen, F L

2015-02-01

406

Role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism  

PubMed Central

Our aim was to investigate the role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism. Coronary angiography and intravascular ultrasound (IVUS) were performed in 60 stable angina pectoris (SAP) patients and 60 unstable angina pectoris (UAP) patients. The chemotactic activity of monocytes in the 2 groups of patients was examined in Transwell chambers. High-sensitivity C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1), regulated on activation in normal T-cell expressed and secreted (RANTES), and fractalkine in serum were examined with ELISA kits, and expression of MCP-1, RANTES, and fractalkine mRNA was examined with real-time PCR. In the SAP group, 92 plaques were detected with IVUS. In the UAP group, 96 plaques were detected with IVUS. The plaques in the UAP group were mainly lipid 51.04% (49/96) and the plaques in the SAP group were mainly fibrous 52.17% (48/92). Compared with the SAP group, the plaque burden and vascular remodeling index in the UAP group were significantly greater than in the SAP group (P<0.01). Chemotactic activity and the number of mobile monocytes in the UAP group were significantly greater than in the SAP group (P<0.01). Concentrations of hs-CRP, MCP-1, RANTES, and fractalkine in the serum of the UAP group were significantly higher than in the serum of the SAP group (P<0.05 or P<0.01), and expression of MCP-1, RANTES, and fractalkine mRNA was significantly higher than in the SAP group (P<0.05). MCP-1, RANTES, and fractalkine probably promote instability of coronary atherosclerotic plaque. PMID:25424368

Zhong, Z.X.; Li, B.; Li, C.R.; Zhang, Q.F.; Liu, Z.D.; Zhang, P.F.; Gu, X.F.; Luo, H.; Li, M.J.; Luo, H.S.; Ye, G.H.; Wen, F.L.

2014-01-01

407

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

Microsoft Academic Search

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

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

1993-01-01

408

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

PubMed Central

Aims Post-mortem pathological studies have shown that a “vulnerable” plaque is the dominant patho-physiological mechanism responsible for acute coronary syndromes (ACS). One way to improve our understanding of these plaques in vivo is by using histological “surrogates” created by intravascular ultrasound derived virtual histology (IVUS-VH). Our aim in this analysis was to determine the relationship between site-specific differences in individual plaque areas between ACS plaques and stable plaques (SP), with a focus on remodelling index and the pattern of calcifying necrosis. Methods and results IVUS-VH was performed before percutaneous intervention in both ACS culprit plaques (CP) n=70 and stable disease (SP) n=35. A total of 210 plaque sites were examined in 105 lesions at the minimum lumen area (MLA) and the maximum necrotic core site (MAX NC). Each plaque site had multiple measurements made including some novel calculations to ascertain the plaque calcification equipoise (PCE) and the calcified interface area (CIA). CP has greater amounts of positive remodelling at the MLA (RI@MLA): 1.1 (±0.17) vs. 0.95 (±0.14) (P<0.001); lower values for PCE 30% vs. 54% (P<0.001) but a higher CIA 5.38 (±2.72) vs. 3.58 (±2.26) (P=0.001). These features can provide discriminatory ability between plaque types with area under the curve (AUC) measurements between 0.65-0.86. The cut-off values with greatest sensitivity and specificity to discriminate CP morphologies were: RI @ MLA >1.12; RI @ MAX NC >1.22; PCE @ MLA <47.1%; PCE @MAX NC <47.3%; CIA @ MLA >2.6; CIA @ MAX NC >3.1. Conclusions Determining the stage of calcifying necrosis, along with the remodelling index can discriminate between stable and ACS related plaques. These findings could be applied in the future to help detect plaques that have a vulnerable phenotype. PMID:25276614

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

2014-01-01

409

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

410

Combinatorial interference of toll-like receptor 2 and 4 synergistically stabilizes atherosclerotic plaque in apolipoprotein E-knockout mice  

PubMed Central

Abstract To test the hypothesis that combinatorial interference of toll-like receptor 2 (TLR2) and TLR4 is superior to isolated interference of TLR2 or TLR4 in stabilizing atherosclerotic plaques, lentiviruses carrying small interfering RNA of TLR2 or TLR4 were constructed and proved efficacious for knocking down mRNA and protein expression of TLR2 or TLR4 significantly in vitro. One hundred and fifty apolipoprotein E?/? mice fed a high-fat diet were divided into the control, mock, TLR2i, TLR4i and TLR2 + 4i subgroups and a constrictive collar was placed around carotid artery of these mice to induce plaque formation. TLR2i and TLR4i viral suspension was transfected into carotid plaques, respectively, in TLR2i and TLR4i subgroups, or in combination in TLR2 + 4i subgroup. Four weeks after lentivirus transfection, mRNA and protein expression of TLR2 or TLR4 was attenuated markedly in carotid plaques, leading to reduced local inflammatory cytokine expression and plaque content of lipid and macrophages, increased plaque content of collagen and lowered plaque vulnerability index. Factorial ANOVA analysis revealed that there was a synergistic effect between TLR4i and TLR2i in stabilizing plaques. In conclusion, combinatorial interference of TLR2 and TLR4 reduces local inflammation and stabilizes plaques more effectively than interference of TLR2 or TLR4 alone. PMID:20132416

Yang, Jian Min; Wang, Yan; Qi, Li Hang; Wang, Ying; Gao, Fei; Ding, Shi Fang; Ni, Mei; Liu, Chun Xi; Zhang, Cheng; Zhang, Yun

2011-01-01

411

Application of Confocal Microscopy for 3D Assessment of Carotid Plaque Structure: Implications for Carotid Blood Flow and Stroke Research  

PubMed Central

Background: Little information is available on how forces resulting from fluid flow interact with structural stability of carotid atherosclerotic plaque and how such interactions may impact on stroke prevention; investigation of the 3D structure of plaque could help in such studies. The aim of this study was to investigate whether confocal microscopy can be used to obtain 3D visualization of the structure of atherosclerotic carotid plaques. Methods: Carotid plaque specimens were collected from routine end-arterectomy surgical operations. Both bright-field microscopy and Laser Scanning Confocal Microscopy (LSCM) were used to generate 3D image data-sets and visualizations of surgically removed carotid plaques. Results: Evidence of carotid plaque vulnerability was demonstrated by reduced fibrous cap thickness and large lipid-necrotic core with evidence of cracking. Conclusion: The generation of 3D images of carotid plaques could help in: (i) investigating key features that affect plaque structural stability; (ii) comparing 3D microstructure of the plaque with clinical imaging assessment and blood flow investigations; and (iii) developing markers to identify patients requiring clinical intervention. PMID:22518263

Khattab, Ahmed; Wertheim, David; Petford, Nick; Kirk, Ruth; Wijesinghe, Lasantha; Ali, Ibtisam

2011-01-01

412

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

PubMed Central

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

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

1991-01-01

413

Assessment of MMP-9, TIMP-1, and COX2 in normal tissue and in advanced symptomatic and asymptomatic carotid plaques  

Microsoft Academic Search

Background  Mature carotid plaques are complex structures, and their histological classification is challenging. The carotid plaques of\\u000a asymptomatic and symptomatic patients could exhibit identical histological components.\\u000a \\u000a \\u000a \\u000a \\u000a Objectives  To investigate whether matrix metalloproteinase 9 (MMP-9), tissue inhibitor of MMP (TIMP), and cyclooxygenase-2 (COX-2) have\\u000a different expression levels in advanced symptomatic carotid plaques, asymptomatic carotid plaques, and normal tissue.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Thirty patients admitted for carotid

Liz Andréa V Baroncini; Lia S Nakao; Simone G Ramos; Antonio Pazin Filho; Luiz Otávio Murta Jr; Max Ingberman; Cristiane Tefé-Silva; Dalton B Précoma

2011-01-01

414

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

NASA Astrophysics Data System (ADS)

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

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

2000-12-01

415

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

NASA Astrophysics Data System (ADS)

A feasibility study was undertaken in order to investigate alternative noninvasive treatment options for atherosclerosis. In particular, the aim of this study was to investigate the potential use of Dual-Mode Ultrasound Arrays (DMUAs) for image guided treatment of atheromatous plaques. DMUAs offer a unique treatment paradigm for image-guided surgery allowing for robust image-based identification of tissue targets for localized application of HIFU. In this study we present imaging and therapeutic results form a 3.5 MHz, 64-element fenestrated prototype DMUA for targeting lesions in the femoral artery of familial hypercholesterolemic (FH) swine. Before treatment, diagnostic ultrasound was used to verify the presence of plaque in the femoral artery of the swine. Images obtained with the DMUA and a diagnostic (HST 15-8) transducer housed in the fenestration were analyzed and used for guidance in targeting of the plaque. Discrete therapeutic shots with an estimated focal intensity of 4000-5600 W/cm2 and 500-2000 msec duration were performed at several planes in the plaque. During therapy, pulsed HIFU was interleaved with single transmit focus imaging from the DMUA and M2D imaging from the diagnostic transducer for further analysis of lesion formation. After therapy, the swine's were recovered and later sacrificed after 4 and 7 days for histological analysis of lesion formation. At sacrifice, the lower half of the swine was perfused and the femoral artery with adjoining muscle was fixed and stained with H&E to characterize HIFU-induced lesions. Histology has confirmed that localized thermal lesion formation within the plaque was achieved according to the planned lesion maps. Furthermore, the damage was confined to the plaque tissue without damage to the intima. These results offer the promise of a new treatment potentially suited for vulnerable plaques. The results also provide the first real-time demonstration of DMUA technology in targeting fine tissue structures for precise lesion formation in the presence or arterial pulsation and tissue motion. In this paper, we show results from targeting both proximal and distal sides of the vessel wall with a series of 5 - 7 discrete shots in each plane (typically three planes per plaque). Experiments to demonstrate a full treatment forming contiguous lesion within the target plaque are currently underway.

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

2012-11-01

416

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

PubMed Central

Cardiovascular disease (CVD) is becoming the number one cause of death worldwide. Atherosclerotic plaque rupture and progression are closely related to most severe cardiovascular syndromes such as heart attack and stroke. Mechanisms governing plaque rupture and progression are not well understood. A computational procedure based on three-dimensional meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating patients were scanned three times (T1, T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Since there was insufficient data with the current technology to quantify individual plaque component growth, the whole plaque was assumed to be uniform, homogeneous, isotropic, linear, and nearly incompressible. The linear elastic model was used. The 3D plaque model was discretized and solved using a meshless generalized finite difference (GFD) method. Four growth functions with different combinations of wall thickness, stress, and neighboring point terms were introduced to predict future plaque growth based on previous time point data. Starting from the T2 plaque geometry, plaque progression was simulated by solving the solid model and adjusting wall thickness using plaque growth functions iteratively until T3 is reached. Numerically simulated plaque progression agreed very well with the target T3 plaque geometry with errors ranging from 11.56%, 6.39%, 8.24%, to 4.45%, given by the four growth functions. We believe this is the first time 3D plaque progression simulation based on multi-year patient-tracking data was reported. Serial MRI-based progression simulation adds time dimension to plaque vulnerability assessment and will improve prediction accuracy for potential plaque rupture risk. PMID:20730039

Yang, Chun; Tang, Dalin; Atluri, Satya

2010-01-01

417

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

PubMed

Cardiovascular disease (CVD) is becoming the number one cause of death worldwide. Atherosclerotic plaque rupture and progression are closely related to most severe cardiovascular syndromes such as heart attack and stroke. Mechanisms governing plaque rupture and progression are not well understood. A computational procedure based on three-dimensional meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating patients were scanned three times (T1, T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Since there was insufficient data with the current technology to quantify individual plaque component growth, the whole plaque was assumed to be uniform, homogeneous, isotropic, linear, and nearly incompressible. The linear elastic model was used. The 3D plaque model was discretized and solved using a meshless generalized finite difference (GFD) method. Four growth functions with different combinations of wall thickness, stress, and neighboring point terms were introduced to predict future plaque growth based on previous time point data. Starting from the T2 plaque geometry, plaque progression was simulated by solving the solid model and adjusting wall thickness using plaque growth functions iteratively until T3 is reached. Numerically simulated plaque progression agreed very well with the target T3 plaque geometry with errors ranging from 11.56%, 6.39%, 8.24%, to 4.45%, given by the four growth functions. We believe this is the first time 3D plaque progression simulation based on multi-year patient-tracking data was reported. Serial MRI-based progression simulation adds time dimension to plaque vulnerability assessment and will improve prediction accuracy for potential plaque rupture risk. PMID:20730039

Yang, Chun; Tang, Dalin; Atluri, Satya

2010-01-01

418

Timing of Estrogen Replacement Influences Atherosclerosis Progression and Plaque Leukocyte Populations in ApoE?/? Mice  

PubMed Central

Studies of the effects of estrogen replacement therapy on coronary heart disease risk have produced conflicting results. We hypothesize that this may be explained by differences in the length of estrogen deficiency prior to initiation of treatment and associated variation in plaque inflammation or stage of progression. The goal of this study was to determine whether estrogen administered after a period of deficiency affects plaque progression and leukocyte populations. Ovariectomized ApoE?/? mice were treated as follows: Group 1: continuous estrogen for 90 days (E+/+); group 2: placebo for 45 days followed by estrogen for 45 days (E?/+); group 3: estrogen for 45 days followed by placebo for 45 days (E+/?); and group 4: placebo for 90 days (E?/?). Serum lipoprotein concentrations, plaque size and inflammatory cell (macrophage, CD3+, CD4+, CD8+, dendritic cell, and NK cell) densities were quantified. Plaque size was smaller in groups receiving early estrogen therapy. CD3+ and total inflammatory cell densities were lower in late estrogen therapy groups. The CD8 to dendritic cell ratio was significantly lower in the E?/+ group only. These results suggest that a period of estrogen deficiency followed by reintroduction alters the immunologic environment of atherosclerotic lesions as well as plaque progression. PMID:18374339

Register, Thomas C.; Adams, Michael R.; St.Clair, Richard W.; Espeland, Mark A.; Williams, J. Koudy

2008-01-01

419

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

420

Association between increased epicardial adipose tissue volume and coronary plaque composition.  

PubMed

To assess the relationship between epicardial adipose tissue volume (EATV) and plaque vulnerability in significant coronary stenosis using a 40-MHz intravascular ultrasound (IVUS) imaging system (iMap-IVUS), we analyzed 130 consecutive patients with coronary stenosis who underwent dual-source computed tomography (CT) and cardiac catheterization. Culprit lesions were imaged by iMap-IVUS before stenting. The iMAP-IVUS system classified coronary plaque components as fibrous, lipid, necrotic, or calcified tissue, based on the radiofrequency spectrum. Epicardial adipose tissue was measured as the tissue ranging from -190 to -30 Hounsfield units. EATV, calculated as the sum of the fat areas on short-axis images, was 85.0 ± 34.0 cm(3). There was a positive correlation between EATV and the percentage of necrotic plaque tissue (R (2) = 0.34, P < 0.01), while there was a negative correlation between EATV and the percentage of fibrous tissue (R (2) = 0.24, P < 0.01). Multivariate analysis revealed that an increased low-density lipoprotein cholesterol level (? = 0.15, P = 0.03) and EATV (? = 0.14, P = 0.02) were independently associated with the percentage of necrotic plaque tissue. An increase in EATV was associated with the development of coronary atherosclerosis and, potentially, with the most dangerous type of plaque. PMID:23982316

Yamashita, Kennosuke; Yamamoto, Myong Hwa; Ebara, Seitarou; Okabe, Toshitaka; Saito, Shigeo; Hoshimoto, Koichi; Yakushiji, Tadayuki; Isomura, Naoei; Araki, Hiroshi; Obara, Chiaki; Ochiai, Masahiko

2014-09-01