Note: This page contains sample records for the topic instabile arteriosklerotische plaque from
While these samples are representative of the content of,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of
to obtain the most current and comprehensive results.
Last update: November 12, 2013.

Fishbowl Plaques.  

ERIC Educational Resources Information Center

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

Lambert, Phyllis Gilchrist



Operative Versorgung instabiler osteoporotischer Wirbelsäulenfrakturen  

Microsoft Academic Search

Zusammenfassung  Die Kombination von Kyphoplastie und Fixateur interne ist bei osteoporotischen instabilen Wirbelfrakturen eine wesentliche\\u000a Therapie. Die Materialkosten von ca. 5500 Euro sind mit den Erlösen der DRG I09 nicht hinreichend gedeckt. So werden die Eingriffe\\u000a oft zweizeitig nach einem Intervall von 30 Tagen durchgeführt. Dies hat für die Patienten eine vermehrte Belastung und z. T.\\u000a auch Repositionsverluste zur Folge.\\u000a \\u000a Daher haben wir im Jahr

A. Prokop; M. Wollny; N. Futterer; U. Berner; J. Volbracht; J. Windolf; H. Siebert



Histopathological classification of tympanosclerotic plaques  

Microsoft Academic Search

Tympanosclerotic plaques seen in the middle ear and tympanic membrane as a sequelae of otitis media have different characteristics.\\u000a Tympanosclerotic plaque consistency shows a wide range from soft to hard during surgical excision and can be classified histologically.\\u000a The aim of this study is to classify surgically excised tympanosclerotic plaques macroscopically and histologically. Seventeen\\u000a surgically excised tympanosclerotic tissues were examined

Adin Selcuk; Serdar Ensar?; Ayse Kose Sarg?n; Belgin Can; Huseyin Dere



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



Control of Specific Plaque Bacteria  

Microsoft Academic Search

The Specific Plaque Hypothesis posits that particular bacteria are of unique importance in the etiology of dental caries and periodontal diseases, and a logical conclusion is that these bacteria should be the targets for our 'magic bullets' in devising plaque-control methods. This paper considers the development of preventive measures based on understanding of the significance of particular bacterial species and

R. R. B. Russell



Dental plaque as a biofilm  

Microsoft Academic Search

Dental plaque is the diverse microbial community found on the tooth surface embedded in a matrix of polymers of bacterial and salivary origin. Once a tooth surface is cleaned, a conditioning film of proteins and glycoproteins is adsorbed rapidly to the tooth surface. Plaque formation involves the interaction between early bacterial colonisers and this film (the acquired enamel pellicle). To

P D Marsh; D J Bradshaw



Plaque quantitation through protein measurement.  


This study was undertaken to establish whether the quantitation of dental plaque protein by a dye-binding method (Coomassie G-250) may be used as an index of the amount of dental plaque sampled. Ten sites were sampled in 34 children on 5 occasions at 4 month intervals. The mean protein concentration in 1391 plaque samples was 6.9 +/- 4.1 micrograms (micrograms) (mean +/- standard deviation). A three-way analysis of variance showed that the plaque protein concentration was similar at the different sampling sites in the same child (p = 0.14), but statistically significant differences were observed with respect to time of sampling (F = 36.24; p = 0.0001) and individual sampled (F = 5.69; p = 0.0001). These observations indicate that plaque bacterial counts may be expressed as units of protein concentration and this method may be useful to relate the number of viable bacteria to an estimate of the amount of plaque collected. This ratio allows standardisation for any variation in the amount of plaque collected. PMID:1401432

Smit, A; Cleaton-Jones, P E; Boardman, M E



Disappearance of La Caille Plaque  

NASA Astrophysics Data System (ADS)

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



Dental plaque identification at home  


... 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 ...


A Plaque Assay for Feline Panleukopenia Virus  

Microsoft Academic Search

SUMMARY Plaque formation with representative strains of feline panleukopenia virus (FPV) has been obtained using a permanent line of feline kidney cells under agarose over- lay. FPV-infected cells appear as white plaques after neutral red staining. Plaque size is determined by the extent of cell division in the infected monolayer. FPV assay by the plaque procedure is rapid and gives




Carbohydrates in Pooled Dental Plaque  

Microsoft Academic Search

Dental plaque was collected from approximately 3,500 schoolchildren, and immediately pooled and frozen. The lyophilized plaque was processed in several batches as follows:After an aqueous extraction the water-insoluble portion was further extracted with 1 N KOH. Both aqueous and alkaline extracts were further subfractionated by precipitation at different ethanol concentrations. Nature and composition of carbohydrates in sub-fractions were investigated using

P. Hotz; B. Guggenheim; R. Schmid



Recent concepts in plaque formation.  


Dental plaque is an adherent, bacterial film, and is the main pathological agent for periodontal diseases. The formation of dental plaque can occur both supragingivally and subgingivally. The development of plaque is a three-step process. Following the formation of a pellicle, pioneer micro-organisms will adhere to it, proliferate and form colonies. The final stage involves the aggregation of filamentous organisms and spirochetes into a cohesive biofilm. Many products of the plaque bacteria reach the subepithelial tissue, causing inflammatory responses such as increased vascularity and leukocyte diapedesis. Both supragingival and subgingival plaque may form a hard, mineralized mass called calculus. The surface of calculus harbours bacteria, which may exacerbate the inflammatory responses. An effective oral antiseptic must be active against a wide range of Gram-positive and Gram-negative bacterial species, including streptococci and fusobacteria. Ideally, an effective agent would also penetrate the plaque biofilm. Data show that essential oil and chlorhexidine mouthwashes have the broadest antimicrobial effects. PMID:12787195

Bernimoulin, J-P



Plaque Assay for Murine Norovirus  

PubMed Central

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

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



Effects of bacteriophage traits on plaque formation  

PubMed Central

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



Clustering of plaques contributes to plaque growth in a mouse model of Alzheimer's disease.  


Amyloid-? (A?) plaque deposition plays a central role in the pathogenesis of Alzheimer's disease (AD). Post-mortem analysis of plaque development in mouse models of AD revealed that plaques are initially small, but then increase in size and become more numerous with age. There is evidence that plaques can grow uniformly over time; however, a complementary hypothesis of plaque development is that small plaques cluster and grow together thereby forming larger plaques. To investigate the latter hypothesis, we studied plaque formation in APPPS1 mice using in vivo two-photon microscopy and immunohistochemical analysis. We used sequential pre- and post-mortem staining techniques to label plaques at different stages of development and to detect newly emerged plaques. Post-mortem analysis revealed that a subset (22 %) of newly formed plaques appeared very close (<40 ?m) to pre-existing plaques and that many close plaques (25 %) that were initially separate merged over time to form one single large plaque. Our results suggest that small plaques can cluster together, thus forming larger plaques as a complementary mechanism to simple uniform plaque growth from a single initial plaque. This study deepens our understanding of A? deposition and demonstrates that there are multiple mechanisms at play in plaque development. PMID:23775142

McCarter, Joanna F; Liebscher, Sabine; Bachhuber, Teresa; Abou-Ajram, Claudia; Hübener, Mark; Hyman, Bradley T; Haass, Christian; Meyer-Luehmann, Melanie



Pathophysiology of atherosclerosis plaque progression.  


Atherosclerotic plaque rupture with luminal thrombosis is the most common mechanism responsible for the majority of acute coronary syndromes and sudden coronary death. The precursor lesion of plaque rupture is thought to be a thin cap fibroatheroma (TCFA) or "vulnerable plaque". TCFA is characterised by a necrotic core with an overlying thin fibrous cap (?65 ?m) that is infiltrated by macrophages and T-lymphocytes. Intraplaque haemorrhage is a major contributor to the enlargement of the necrotic core. Haemorrhage is thought to occur from leaky vasa vasorum that invades the intima from the adventitia as the intima enlarges. The early atherosclerotic plaque progression from pathologic intimal thickening (PIT) to a fibroatheroma is thought to be the result of macrophage infiltration. PIT is characterised by the presence of lipid pools which consist of proteoglycan with lipid insudation. The conversion of the lipid pool to a necrotic core is poorly understood but is thought to occur as a result of macrophage infiltration which releases matrix metalloproteinase (MMPs) along with macrophage apoptosis that leads to the formation of a acellular necrotic core. The fibroatheroma has a thick fibrous cap that begins to thin over time through macrophage MMP release and apoptotic death of smooth muscle cells converting the fibroatheroma into a TCFA. Other causes of thrombosis include plaque erosion which is less frequent than plaque rupture but is a common cause of thrombosis in young individuals especially women <50 years of age. The underlying lesion morphology in plaque erosion consists of PIT or a thick cap fibroatheroma. Calcified nodule is the least frequent cause of thrombosis, which occurs in older individuals with heavily calcified and tortious arteries. PMID:23541627

Sakakura, Kenichi; Nakano, Masataka; Otsuka, Fumiyuki; Ladich, Elena; Kolodgie, Frank D; Virmani, Renu



Plaque Formation by Virulent Shigella flexneri.  

National Technical Information Service (NTIS)

An in vitro tissue culture plaque assay was developed to investigate the intracellular replication and intercellular spread of virulent shigellae. Shigella plaques were formed in HeLa cell monolayers in the presence of an agarose overlay containing tissue...

E. V. Oaks M. E. Wingfield S. B. Formal



Multiphoton microscopy of atheroslcerotic plaques  

NASA Astrophysics Data System (ADS)

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

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



Antiangiogenic therapy for normalization of atherosclerotic plaque vasculature: a potential strategy for plaque stabilization  

Microsoft Academic Search

Angiogenesis within human atherosclerotic plaques has an important role in plaque progression as immature blood vessels leak red blood cells and inflammatory mediators into the plaque center. Accumulation of free cholesterol from red blood cell membranes potentially increases the size of the necrotic core and triggers a chain of events that promote plaque destabilization. Antiangiogenic agents have been shown to

Aloke V Finn; Frank D Kolodgie; Renu Virmani; Rakesh K Jain; Herman K Gold



Relationship Between Dental Plaque Indices and Bacteria in Dental Plaque and Those in Saliva  

Microsoft Academic Search

A variety of indices has been developed for the quantitation of dental plaque. The aim of this study was to determine the correlation between the Löe plaque index and the number of bacteria on the same tooth. Furthermore, the effect of plaque accumulation on the salivary counts of some dental plaque organisms was estimated. Twenty volunteers were asked to abstain

M. J. M. Schaeken; T. J. Creugers; J. S. Van Der Hoeven



Shear stress and plaque development.  


Although traditional cardiovascular risk factors 'prime the soil' for atherogenesis systemically, atherosclerosis primarily occurs in a site-specific manner with a predilection towards the inner wall of curvatures and outer wall of bifurcations with sparing of flow-dividers. Wall shear stress is a frictional force exerted parallel to the vessel wall that leads to alteration of the endothelial phenotype, endothelial cell signaling, gene and protein expression leading to a proinflammatory phenotype, reduced nitric oxide availability and disruption of the extracellular matrix, which in turn leads to plaque development. Clinical and experimental data are emerging that suggest the pathobiology associated with abnormal wall shear stress results in atherosclerotic plaque development and progression. PMID:20397828

Dhawan, Saurabh S; Avati Nanjundappa, Ravi P; Branch, Jonathan R; Taylor, W Robert; Quyyumi, Arshed A; Jo, Hanjoong; McDaniel, Michael C; Suo, Jin; Giddens, Don; Samady, Habib



Visualization of the Vulnerable Plaque  

Microsoft Academic Search

Thrombosis is the main cause of acute coronary syndrome and myocardial infarction (Naghavi et al., 2003). The mechanism underlying thrombus formation is presently under debate, but several pathological conditions have\\u000a been identified from human postmortem studies that correspond with the presence of thrombus. Of these conditions plaque rupture\\u000a is the most common, but erosion of the endothelial layer and existence

Rob Krams; Johannes Schaar; Frank Helderman; Caroline Cheng; Babak Mousavi Gourabi; L. C. A. Damme; D. Segers; Evelyn Regar; Cornelis J. Slager; Pim J. Feyter; Anton F. W. Steen; Patrick W. Serruys


Gene therapy for the vulnerable plaque  

Microsoft Academic Search

Rupture of coronary atherosclerotic plaque and subsequent formation of an occlusive intracoronary thrombus (Figure 410-1)\\u000a are the major events precipitating acute coronary syndromes [1–6]. The vulnerable plaque is smaller in size [7], richer in lipids [1],[2], and more infiltrated with macrophages [2,3,8–10] than the stable, fibromuscular lesion. Therefore, lowering the lipid and\\/or macrophage pools stored in the plaque may “stabilize”

Douglas W. Losordo; Jeffrey M. Isner


Biomechanical structural stresses of atherosclerotic plaques.  


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



Local Maximal Stress Hypothesis and Computational Plaque Vulnerability Index for Atherosclerotic Plaque Assessment  

PubMed Central

It is believed that atherosclerotic plaque rupture may be related to maximal stress conditions in the plaque. More careful examination of stress distributions in plaques reveals that it may be the local stress/strain behaviors at critical sites such as very thin plaque cap and locations with plaque cap weakness that are more closely related to plaque rupture risk. A “local maximal stress hypothesis” and a stress-based computational plaque vulnerability index (CPVI) are proposed to assess plaque vulnerability. A critical site selection (CSS) method is proposed to identify critical sites in the plaque and critical stress conditions which are be used to determine CPVI values. Our initial results based on 34 2D MRI slices from 14 human coronary plaque samples indicate that CPVI plaque assessment has an 85% agreement rate (91% if the square root of stress values is used) with assessment given by histopathological analysis. Large-scale and long-term patient studies are needed to further validate our findings for more accurate quantitative plaque vulnerability assessment.

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



Cholesterol in human atherosclerotic plaque is a marker for underlying disease state and plaque vulnerability  

PubMed Central

Background Cholesterol deposition in arterial wall drives atherosclerosis. The key goal of this study was to examine the relationship between plaque cholesterol content and patient characteristics that typically associate with disease state and lesion vulnerability. Quantitative assays for free cholesterol, cholesteryl ester, triglyceride, and protein markers in atherosclerotic plaque were established and applied to plaque samples from multiple patients and arterial beds (Carotid and peripheral arteries; 98 lesions in total). Results We observed a lower cholesterol level in restenotic than primary peripheral plaque. We observed a trend toward a higher level in symptomatic than asymptomatic carotid plaque. Peripheral plaque from a group of well-managed diabetic patients displayed a weak trend of more free cholesterol deposition than plaque from non-diabetic patients. Plaque triglyceride content exhibited less difference in the same comparisons. We also measured cholesterol in multiple segments within one carotid plaque sample, and found that cholesterol content positively correlated with markers of plaque vulnerability, and negatively correlated with stability markers. Conclusions Our results offer important biological validation of cholesterol as a key lipid marker for plaque severity. Results also suggest cholesterol is a more sensitive plaque marker than routine histological staining for neutral lipids.



Phyto (in)stabilization of elements  

Microsoft Academic Search

The effects of plants (corn, soybean, sunflower) and fertilizer on mobility of more than 60 elements were assessed in a greenhouse experiment. Unplanted columns with the same soil served as controls. Half the columns received fertilizer and all columns were watered at the same rate. At the end of the experiment, the columns were watered to mimic a rainstorm event

Donna L. Jacob; David G. Hopkins; Marinus L. Otte



Imaging of High-Risk Plaque  

Microsoft Academic Search

‘High-risk’ or ‘vulnerable’ plaques in the coronary arteries have characteristics that make them more prone to disruption and subsequent thrombosis – the mechanisms of most acute coronary syndromes (ACS). There are a number of imaging modalities that are capable of visualizing these features. This article discusses invasive modalities for identifying ‘high-risk’ plaque such as intravascular ultrasound, coronary angioscopy, optical coherence

Dmitry Nemirovsky



Fluoride bioavailability in saliva and plaque  

PubMed Central

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



New insights into atherosclerotic plaque rupture  

Microsoft Academic Search

Coronary artery atherosclerosis is the major cause of mortality and morbidity in the indus- trialised world. Progressive narrowing of cor- onary arteries causes angina. However, it is rupture of the plaque that causes the cata- strophic consequences of atherosclerosis, such as myocardial infarction. Recent work has identified that the stability of the plaque rather than its absolute size determines the

D M Braganza; M R Bennett



Advanced Techniques for MRI of Atherosclerotic Plaque  

PubMed Central

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

Kerwin, William S.; Canton, Gador



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



Effect of N -chlorotaurine mouth rinses on plaque regrowth and plaque vitality  

Microsoft Academic Search

The purpose of this 4-day plaque regrowth study was to assess the effect of N-chlorotaurine (NCT) mouth rinses on plaque inhibition and plaque vitality. Eighty volunteers participated in this investigator-blind,\\u000a randomized, clinical controlled study in parallel groups. No oral hygiene was permitted except rinsing with a 2% or 3% NCT\\u000a mouth rinse, a positive or a negative control. Primary parameters

K. Lorenz; D. Mayer; G. Bruhn; B. Noack; M. Brecx; C. Heumann; H. Toutenburg; L. Netuschil; M. Nagl; W. Gottardi; T. Hoffmann




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 ...


Symptomatic and asymptomatic carotid artery plaque  

PubMed Central

Carotid atherosclerotic plaques represent both stable and unstable atheromatous lesions. Atherosclerotic plaques that are prone to rupture owing to their intrinsic composition such as a large lipid core, thin fibrous cap and intraplaque hemorrhage are associated with subsequent thromboembolic ischemic events. At least 15–20% of all ischemic strokes are attributable to carotid artery atherosclerosis. Characterization of plaques may enhance the understanding of natural history and ultimately the treatment of atherosclerotic disease. MRI of carotid plaque and embolic signals during transcranial Doppler have identified features beyond luminal stenosis that are predictive of future transient ischemic attacks and stroke. The value of specific therapies to prevent stroke in symptomatic and asymptomatic patients with severe carotid artery stenosis are the subject of current research and analysis of recently published clinical trials that are discussed in this article.

Mughal, Majid M; Khan, Mohsin K; DeMarco, J Kevin; Majid, Arshad; Shamoun, Fadi; Abela, George S



Motion compensated reconstructions of calcified coronary plaques in cardiac CT  

Microsoft Academic Search

In order to obtain motion-compensated reconstructions of calcified coronary plaques in cardiac CT, the dynamic trajectory of the plaque must be known rather accurately. The purpose of this study is to evaluate whether the dynamic trajectories of a plaque extracted from reconstructions provided by a previously developed tracking algorithm can be used for obtaining motion-compensated reconstructions of this plaque. A

Martin King; Xiaochuan Pan; Maryellen Giger; Kenji Suzuki



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

PubMed Central

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

Hagg, Sara; Salehpour, Mehran; Noori, Peri; Lundstrom, Jesper; Possnert, Goran; Takolander, Rabbe; Konrad, Peter; Rosfors, Stefan; Ruusalepp, Arno; Skogsberg, Josefin; Tegner, Jesper; Bjorkegren, Johan



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



Visualising noncalcified coronary plaques by CT  

Microsoft Academic Search

Due to a rapid improvement of the new generation submillimetre multislice CT-technology noninvasive tomographic imaging of the coronary vessel wall has become reality. First clinical studies have shown the ability in particular of 16-slice CT to determine plaque burden, plaque composition and compensatory vessel-wall remodelling. These novel findings already constitute an important step forward to assess coronary atherosclerosis noninvasively in

Alexander W. Leber; Andreas Knez; Alexander Becker; Christoph Becker; Maximilian Reiser; Gerhard Steinbeck; Peter Boekstegers



Drug-eluting stents and vulnerable plaque  

Microsoft Academic Search

Coronary artery disease with acute coronary syndromes (ACS) is the leading cause of death worldwide in both men and women.\\u000a ACS mostly occur as a result of rupture of “vulnerable plaque” with a superimposed thrombus formation, which ultimately leads\\u000a to distal cessation of blood flow. Vulnerable plaque mostly occurs in mildly obstructive coronary lesions rather than severely\\u000a stenosed (< 50%)

Mehmet Cilingiroglu; Faisal Khan



Radiolabelled probes for imaging of atherosclerotic plaques  

PubMed Central

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

Temma, Takashi; Saji, Hideo



Detection of High-Risk Atherosclerotic Plaque  

PubMed Central

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

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



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


This presentation provides an overview of the technologies available for the chemical control of plaque. It is generally accepted that the formation of dental plaque at the interfaces of tooth/gingiva is one of the major causes of gingival inflammation and dental caries. Several therapeutic approaches have been used to control dental plaque and supragingival infections. These include fluoride preparations such as stannous fluoride, oxygenating agents, anti-attachment agents, and cationic and non-cationic antibacterial agents. Among the fluoride preparations, stable stannous fluoride pastes and gels have been shown to reduce supragingival plaque, gingivitis, hypersensitivity and caries. The effect of the oxygenating agents on the supragingival plaque has been equivocal, but recent data indicate that a stable agent which provides sustained active oxygen release is effective in controlling plaque. A polymer, PVPA, which reduced attachment of bacteria to teeth was shown to significantly reduce plaque formation in humans. A new generation of antibacterials includes non-ionics such as triclosan, which in combination with a special polymer delivery system, has been shown to reduce plaque, gingivitis, supragingival calculus and dental caries in long-term studies conducted around the world. Unlike the first generation of agents, the triclosan/copolymer/sodium fluoride system is effective in long-term clinicals and does not cause staining of teeth, increase in calculus, or disturbance in the oral microbial ecology. PMID:9395116

Gaffar, A; Afflitto, J; Nabi, N



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

PubMed Central

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 degree of neurodegeneration observed in humans. In this study, we imaged the Zn, Cu, Fe, and Ca ion distribution in the PSAPP transgenic mouse model representing end-stage AD (N = 6) using synchrotron X-ray fluorescence (XRF) microprobe. In order to account for differences in density in the plaques, the relative protein content was imaged with synchrotron Fourier transform infrared microspectroscopy (FTIRM) on the same samples. FTIRM results revealed a 61% increase in protein content in the plaques compared to the surrounding tissue. After normalizing to protein density, we found that the PSAPP plaques contained only a 29% increase in Zn and there was actually less Cu, Fe, and Ca in the plaque compared to the surrounding tissue. Since metal-binding to A? is thought to induce redox chemistry that is toxic to neurons, the reduced metal-binding in PSAPP mice is consistent with the lack of neurodegeneration in these animals. These findings were in stark contrast to the high metal ion content observed in human AD plaques, further implicating the role of metal ions in human AD pathology.

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



Thermal detection of cellular infiltrates in living atherosclerotic plaques: possible implications for plaque rupture and thrombosis  

Microsoft Academic Search

SummaryBackground Atherosclerotic lesions are heterogeneous and prognosis cannot easily be predicted, even with intracoronary ultrasound and angioscopy. Serial angiographic and necropsy studies suggest that the risk of plaque rupture correlates only weakly with the degree of stenosis. Most ruptured plaques are characterised by a large pool of cholesterol or necrotic debris and a thin fibrous cap with a dense infiltration

W. Casscells; W. K. Vaughn; H. McAllister; J. T. Willerson; B. Hathorn; M. David; T. Krabach; G. Bearman



Hyperspectral imaging of atherosclerotic plaques in vitro  

NASA Astrophysics Data System (ADS)

Vulnerable plaques constitute a risk for serious heart problems, and are difficult to identify using existing methods. Hyperspectral imaging combines spectral- and spatial information, providing new possibilities for precise optical characterization of atherosclerotic lesions. Hyperspectral data were collected from excised aorta samples (n = 11) using both white-light and ultraviolet illumination. Single lesions (n = 42) were chosen for further investigation, and classified according to histological findings. The corresponding hyperspectral images were characterized using statistical image analysis tools (minimum noise fraction, K-means clustering, principal component analysis) and evaluation of reflectance/fluorescence spectra. Image analysis combined with histology revealed the complexity and heterogeneity of aortic plaques. Plaque features such as lipids and calcifications could be identified from the hyperspectral images. Most of the advanced lesions had a central region surrounded by an outer rim or shoulder-region of the plaque, which is considered a weak spot in vulnerable lesions. These features could be identified in both the white-light and fluorescence data. Hyperspectral imaging was shown to be a promising tool for detection and characterization of advanced atherosclerotic plaques in vitro. Hyperspectral imaging provides more diagnostic information about the heterogeneity of the lesions than conventional single point spectroscopic measurements.

Larsen, Eivind L. P.; Randeberg, Lise L.; Olstad, Elisabeth; Haugen, Olav A.; Aksnes, Astrid; Svaasand, Lars O.



Growth of Necrotic Cores in Vulnerable Plaque  

NASA Astrophysics Data System (ADS)

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

Fok, Pak-Wing



Hyperspectral imaging of atherosclerotic plaques in vitro.  


Vulnerable plaques constitute a risk for serious heart problems, and are difficult to identify using existing methods. Hyperspectral imaging combines spectral- and spatial information, providing new possibilities for precise optical characterization of atherosclerotic lesions. Hyperspectral data were collected from excised aorta samples (n = 11) using both white-light and ultraviolet illumination. Single lesions (n = 42) were chosen for further investigation, and classified according to histological findings. The corresponding hyperspectral images were characterized using statistical image analysis tools (minimum noise fraction, K-means clustering, principal component analysis) and evaluation of reflectance/fluorescence spectra. Image analysis combined with histology revealed the complexity and heterogeneity of aortic plaques. Plaque features such as lipids and calcifications could be identified from the hyperspectral images. Most of the advanced lesions had a central region surrounded by an outer rim or shoulder-region of the plaque, which is considered a weak spot in vulnerable lesions. These features could be identified in both the white-light and fluorescence data. Hyperspectral imaging was shown to be a promising tool for detection and characterization of advanced atherosclerotic plaques in vitro. Hyperspectral imaging provides more diagnostic information about the heterogeneity of the lesions than conventional single point spectroscopic measurements. PMID:21361695

Larsen, Eivind L P; Randeberg, Lise L; Olstad, Elisabeth; Haugen, Olav A; Aksnes, Astrid; Svaasand, Lars O



A Plaque Assay System for Several Species of Rickettsia.  

National Technical Information Service (NTIS)

The plaque assay procedure developed in this laboratory for the Bitter Root strain of Rickettsia rickettsii has recently been shown to be appropriate for other rickettsiae. Large (2 mm) distinct plaques were formed when chick primary monolayers were infec...

J. E. McDade J. E. Stakebake P. J. Gerone



Intracoronary imaging for detecting vulnerable plaque.  


It is now generally recognized that acute coronary syndromes most commonly result from disruption of thin-cap fibroatheroma (TCFA), which is characterized by a large necrotic core with an overlying thin-fibrous cap measuring <65 ?m. Recent advances in intracoronary imaging modalities have significantly improved the ability to detect TCFA in vivo. Intravascular ultrasound (IVUS) is perhaps the most promising modality that has been used more than 15 years to evaluate atherosclerotic plaque. IVUS has revealed a lot of the clinical evidence regarding vulnerable plaque detection in live humans. Recently, by analyzing the IVUS acoustic signal before demodulation and scan conversion, IVUS radiofrequency analysis can be used to differentiate adjacent smaller areas of atherosclerotic plaque with heterogeneous composition. Coronary angioscopy allows direct visualization of the coronary artery wall and provides detailed information of the luminal surface of plaque, such as color, thrombus or disruption. Optical coherence tomography imaging, recently been introduced for in vivo human imaging, offers a higher resolution than any other available imaging modality, and can visualize a thin fibrous cap measuring <65 ?m. In this review, we will discuss the features and limitations of each imaging modalities for detecting TCFA. PMID:23370454

Fujii, Kenichi; Hao, Hiroyuki; Ohyanagi, Mitsumasa; Masuyama, Tohru



Structure of Dental Plaque and the Plaque-Enamel Interface in Human Experimental Caries  

Microsoft Academic Search

This study describes the ultrastructrure of dental plaque and the plaque-enamel interface after 2 and 3 weeks’ exposure to a cariogenic challenge. Five dental students carried a total of 25 specimens of smooth surface enamel in intraoral acrylic appliances. During the initial 3 days the volunteers refrained from oral hygiene and performed nine daily mouthrinses with 10% (w\\/v) solutions of

B. Nyvad; O. Fejerskov



Fluorescent Green Plaques: Light at the End of the Catheter?  

PubMed Central

The field of vascular molecular imaging is searching for the `holy grail' of an imaging technique that will quantitatively and reliably assess vulnerable coronary plaques. Fluorescence imaging with indocyanine green specifically identifies lipid-rich plaques in rabbits and in human plaques and represents a promising, though invasive, approach.

Mehta, Nehal N.; Rader, Daniel J.



Rayleigh Mixture Model for Plaque Characterization in Intravascular Ultrasound  

Microsoft Academic Search

Vulnerable plaques are the major cause of carotid and coronary vascular problems, such as heart attack or stroke. A correct modeling of plaque echomorphology and composition can help the identification of such lesions. The Rayleigh distribution is widely used to describe (nearly) homogeneous areas in ultrasound images. Since plaques may contain tissues with heterogeneous re- gions, more complex distributions depending

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



Plaque reduction over time of an integrated oral hygiene system.  


This article compares the efficacy of a prototype integrated system (the IntelliClean System from Sonicare and Crest) in the reduction of supragingival plaque to that of a manual toothbrush and conventional toothpaste. The integrated system was compared to a manual toothbrush with conventional toothpaste in a randomized, single-blinded, parallel, 4-week, controlled clinical trial with 100 subjects randomized to each treatment group. There was a low dropout rate, with 89 subjects in the manual toothbrush group (11% loss to follow-up) and 93 subjects in the integrated system group (7% loss to follow-up) completing the study. The Turesky modification of the Quigley and Hein Plaque Index was used to assess full-mouth plaque scores for each subject. Prebrushing plaque scores were obtained at baseline and at 4 weeks after 14 to 20 hours of plaque accumulation. A survey also was conducted at the conclusion of the study to determine the attitude toward the two oral hygiene systems. The integrated system was found to significantly reduce overall and interproximal prebrushing plaque scores over 4 weeks, both by 8.6%, demonstrating statistically significant superiority in overall plaque reduction (P = .002) and interproximal plaque reduction (P < .001) compared to the manual toothbrush with conventional toothpaste, which showed no significant reduction in either overall plaque or interproximal plaque. This study demonstrates that the IntelliClean System from Sonicare and Crest is superior to a manual toothbrush with conventional toothpaste in reducing overall plaque and interproximal plaque over time. PMID:15637975

Nunn, Martha E; Ruhlman, C Douglas; Mallatt, Philip R; Rodriguez, Sally M; Ortblad, Katherine M



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

Microsoft Academic Search

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

Peter D. Richardson



Clinical Studies of Plaque Control Agents: An Overview  

Microsoft Academic Search

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

Ralph R. Lobene



Antiangiogenic therapy for normalization of atherosclerotic plaque vasculature: a potential strategy for plaque stabilization.  


Angiogenesis within human atherosclerotic plaques has an important role in plaque progression as immature blood vessels leak red blood cells and inflammatory mediators into the plaque center. Accumulation of free cholesterol from red blood cell membranes potentially increases the size of the necrotic core and triggers a chain of events that promote plaque destabilization. Antiangiogenic agents have been shown to prune some tumor vessels and 'normalize' the structure and function of the remaining vasculature, thereby improving the access of chemotherapeutic agents to tumors. We propose that antiangiogenic therapy can similarly stabilize vulnerable 'rupture-prone' plaques by pruning and normalizing immature intraplaque vessels, preventing further intraplaque hemorrhage. This normalization would limit necrotic core enlargement, further luminal narrowing and the degree of inflammation. Such normalization has been realized using vascular endothelial growth factor antagonists for the treatment of cancer and age-related macular degeneration. The development of this novel approach to prevent plaque progression might add to the armamentarium of preventive measures for acute myocardial infarction, stroke and sudden cardiac death. PMID:17712362

Jain, Rakesh K; Finn, Aloke V; Kolodgie, Frank D; Gold, Herman K; Virmani, Renu



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

Microsoft Academic Search

BACKGROUND: Plaque imaging based on magnetic resonance imaging (MRI) represents a new modality for risk assessment in atherosclerosis. It allows classification of carotid plaques in high-risk and low-risk lesion types (I-VIII). Type 2 diabetes mellitus (DM 2) represents a known risk factor for atherosclerosis, but its specific influence on plaque vulnerability is not fully understood. This study investigates whether MRI-plaque

L Esposito; T Saam; P Heider; Angelina Bockelbrink; Jaroslav Pelisek; D Sepp; R Feurer; C Winkler; T Liebig; K Holzer; O Pauly; S Sadikovic; B Hemmer; H Poppert



Magnetic resonance imaging of carotid plaque inflammation in acute coronary syndromes: A sign of multisite plaque activation  

Microsoft Academic Search

Widespread plaque inflammation has been demonstrated in acute coronary syndromes (ACS). We evaluated signs of plaque inflammation in carotid arteries of patients with ACS by contrast-enhanced magnetic resonance imaging (MRI).Carotid MRI was performed in 13 patients with ACS and in 9 controls having at least 1 carotid plaque with a stenosis ?40%. MRI criteria of plaque inflammation were: increased T2

Antonella Lombardo; Vittoria Rizzello; Luigi Natale; Mariaelena Lombardi; Stefano Coli; Francesco Snider; Lorenzo Bonomo; Filippo Crea



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



Study of non-destructive methods to evaluate plaque properties and non-Newtonian blood flow inside arteries with plaque  

Microsoft Academic Search

Knowledge about the flow profile characteristics of blood inside vascular arteries in the presence of plaque is of greater interest to cardio vascular research community. Along with the flow pattern, the study of mechanical properties of the artery vessel wall and plaque is an important phenomenon that supports the detection and diagnosis of the vulnerability of plaque inside the arteries.

Rajagopa Balakrishnan



The gelatinous plaque: its relation to coronary atherosclerosis.  


The relations between the gelatinous plaque and the atherosclerotic plaque were investigated on more than 500 subjects aged 1--40 years. The appearance of the light microscopic aspect of the gelatinous plaque was related to a particular: a) evolution of the process of histolysis involving branch pads and thickened intimas; b) insudation, occurring in nodular proliferations of intimal smooth muscle cells; c) stage of atheroma formation. The results showed that the term gelatinous plaque did not refer to an independent, early atherosclerotic lesion, or a true precursor of advanced lesions,but to an intermediate, transitional stage in the complex histogenesis of the atherosclerotic plaque. PMID:7394458

Velican, C; Velican, D


Significance of ABCA1 in human carotid atherosclerotic plaques  

PubMed Central

The ATP-binding cassette transporter A1 (ABCA1) is an important effector in the regulation of cholesterol efflux from cells. In this study, we assessed the role of ABCA1 in human carotid atherosclerotic plaques (CAPs). We found that ABCA1 and retinoid X receptor ? (RXR?) mRNAs were significantly increased in the atherosclerotic plaques compared to control arteries. The increased ABCA1 mRNA correlated with that of RXR? in plaques. According to the modified American Heart Association plaque classification, atherosclerotic specimens were assigned to three grades, and ABCA1 and RXR? mRNA levels were compared across plaques of different grades. Resultantly, plaques of grade II and III exhibited higher mRNA levels than grade I, but there was no difference in mRNA levels between plaques of grade II and III. By contrast, ABCA1 and RXR? protein levels were notably reduced in plaques relative to control tissues. Similarly, plaques of grade II and III exhibited lower ABCA1 and RXR? protein levels than grade I, and there was no difference in protein levels between plaques of grade II and III. Our findings suggest that decreased ABCA1 protein plays a key role in the pathogenesis of CAP; the regulation of ABCA1 may be mediated by RXR? and ABCA1 mRNA levels may serve as an indicator for plaque stability.




Imaging of coronary atherosclerosis and identification of the vulnerable plaque  

PubMed Central

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

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



Enucleation versus plaque irradiation for choroidal melanoma.  


The Collaborative Ocular Melanoma Study (COMS) is an international, multicenter-controlled study. The organization includes an Executive Committee, Steering Committee, 6 Central Units, 32 Clinical Centers, and a Data and Safety Monitoring Committee. Scientifically, the COMS consists of (1) a randomized trial of patients with medium choroidal melanoma treated with enucleation versus iodine-125 plaque irradiation, (2) a randomized trial of patients with large choroidal melanoma treated with enucleation versus preenucleation external beam irradiation and enucleation, and (3) a prospective observational study of patients with small choroidal melanoma to determine whether a randomized trial of treatment is appropriate. In design and conduct of the COMS, special consideration is given to biostatistics and sample size considerations, iodine-125 plaque irradiation of choroidal melanoma, and coordinated ocular melanoma research. Recruitment is in progress. However, the pool of eligible patients is limited and the COMS needs the continued support and cooperation of ophthalmologists throughout the United States and Canada. PMID:3174030

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



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.



Cellular immune response in multiple sclerosis plaques.  

PubMed Central

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

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



Cataractogenesis after Cobalt-60 eye plaque radiotherapy  

SciTech Connect

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

Kleineidam, M.; Augsburger, J.J. (Wills Eye Hospital, Philadelphia, PA (United States)); Hernandez, C.; Glennon, P.; Brady, L.W. (Hahnemann Univ., Philadelphia, PA (United States))



Angiogenesis in human coronary atherosclerotic plaques.  

PubMed Central

Neovascularization in the walls of coronary arteries is associated with the presence of atherosclerotic plaque. The mechanisms responsible for the formation of these intraplaque microvessels are not understood. The purpose of this study is to examine the prevalence of endothelial cell replication in plaque microvessels. Two hundred and one primary and restenotic coronary atherectomy specimens were analyzed for the presence of microvessels and proliferation as reflected by positive immunolabeling for Ulex agglutinin and the proliferating cell nuclear antigen, respectively. In primary but not restenotic specimens, proliferation of any cell type was associated with the detection of microvessels on the same slide. However, intraplaque microvessels were more commonly found in restenotic compared to primary specimens (P = 0.004). Twelve highly vascularized specimens with evidence of replication were subjected to detailed histomorphological and quantitative image analyses. At 200 x, the most vascular optical field of each slide was identified and consistently included plaque macrophages. Total slide endothelial cell replication indices for these specimens varied, but in some instances were remarkably elevated (eg, 43.5%). The role of intraplaque angiogenesis may be analogous to that of tumor or wound angiogenesis and be important in development and progression of coronary artery lesions and restenosis. Images Figure 4 Figure 5

O'Brien, E. R.; Garvin, M. R.; Dev, R.; Stewart, D. K.; Hinohara, T.; Simpson, J. B.; Schwartz, S. M.



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



Resistance to extinction of low fitness virus subjected to plaque-to-plaque transfers: diversification by mutation clustering 1 1 Edited by J. Karn  

Microsoft Academic Search

Plaque-to-plaque transfers of RNA viruses lead to accumulation of mutations and fitness decrease. To test whether continuing plaque-to-plaque transfers would lead to viral extinction, we have subjected several low fitness foot-and-mouth disease virus (FMDV) clones to up to 130 successive plaque transfers, and have analyzed the evolution of plaque titers and genomic nucleotide sequences. No case of viral extinction could

Cristina Escarm??s; Gema Gómez-Mariano; Mercedes Dávila; Ester Lázaro; Esteban Domingo



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.

Liu, Biyue; Tang, Dalin



A Plaque Assay for the Simian Rotavirus SA11  

Microsoft Academic Search

SUMMARY A sensitive, quantitative and reproducible plaque assay for the measurement of the simian rotavirus SAII is described. Plaque formation required the presence of the facilitators pancreatin or trypsin and diethylaminoethyl-dextran in the agar overlay. SAII produced plaques in three continuous primate cell lines: MA-Io4, CV-I and LLC-MK2. MA-Io 4 cells were the most sensitive.




The Mutability of Small-Plaque-Forming Encephalomyocarditis Virus  

Microsoft Academic Search

SUMMARY Sixty-four single plaque subclones of a small-plaque-forming mutant of encephalomyocarditis virus, EMC\\/r +, were isolated and titrated. In addition to EMC\\/r + virus, some contained large-plaque-forming virus, EMC\\/r. The selective conditions which prevailed during the growth and iso- lation of the subclones were analysed in detail. All the evidence suggests that only negligible differential selection favouring either the parental

D. C. Breeze; H. Subak-Sharpe



Oral biofilm models for mechanical plaque removal  

PubMed Central

In vitro plaque removal studies require biofilm models that resemble in vivo dental plaque. Here, we compare contact and non-contact removal of single and dual-species biofilms as well as of biofilms grown from human whole saliva in vitro using different biofilm models. Bacteria were adhered to a salivary pellicle for 2 h or grown after adhesion for 16 h, after which, their removal was evaluated. In a contact mode, no differences were observed between the manual, rotating, or sonic brushing; and removal was on average 39%, 84%, and 95% for Streptococcus mutans, Streptococcus oralis, and Actinomyces naeslundii, respectively, and 90% and 54% for the dual- and multi-species biofilms, respectively. However, in a non-contact mode, rotating and sonic brushes still removed considerable numbers of bacteria (24–40%), while the manual brush as a control (5–11%) did not. Single A. naeslundii and dual-species (A. naeslundii and S. oralis) biofilms were more difficult to remove after 16 h growth than after 2 h adhesion (on average, 62% and 93% for 16- and 2-h-old biofilms, respectively), while in contrast, biofilms grown from whole saliva were easier to remove (97% after 16 h and 54% after 2 h of growth). Considering the strong adhesion of dual-species biofilms and their easier more reproducible growth compared with biofilms grown from whole saliva, dual-species biofilms of A. naeslundii and S. oralis are suggested to be preferred for use in mechanical plaque removal studies in vitro.

Verkaik, Martinus J.; Busscher, Henk J.; Rustema-Abbing, Minie; Slomp, Anje M.; Abbas, Frank



Oral biofilm models for mechanical plaque removal.  


In vitro plaque removal studies require biofilm models that resemble in vivo dental plaque. Here, we compare contact and non-contact removal of single and dual-species biofilms as well as of biofilms grown from human whole saliva in vitro using different biofilm models. Bacteria were adhered to a salivary pellicle for 2 h or grown after adhesion for 16 h, after which, their removal was evaluated. In a contact mode, no differences were observed between the manual, rotating, or sonic brushing; and removal was on average 39%, 84%, and 95% for Streptococcus mutans, Streptococcus oralis, and Actinomyces naeslundii, respectively, and 90% and 54% for the dual- and multi-species biofilms, respectively. However, in a non-contact mode, rotating and sonic brushes still removed considerable numbers of bacteria (24-40%), while the manual brush as a control (5-11%) did not. Single A. naeslundii and dual-species (A. naeslundii and S. oralis) biofilms were more difficult to remove after 16 h growth than after 2 h adhesion (on average, 62% and 93% for 16- and 2-h-old biofilms, respectively), while in contrast, biofilms grown from whole saliva were easier to remove (97% after 16 h and 54% after 2 h of growth). Considering the strong adhesion of dual-species biofilms and their easier more reproducible growth compared with biofilms grown from whole saliva, dual-species biofilms of A. naeslundii and S. oralis are suggested to be preferred for use in mechanical plaque removal studies in vitro. PMID:19565279

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



Plaque stability and the southern European paradox.  


Differences between European countries in coronary heart disease mortality were initially described in the 20th century, and albeit less dramatic than first reported, these differences remain substantial. Three main hypotheses have been proposed to explain the so-called "Mediterranean paradox": a) underestimation of coronary heart disease mortality due to methodological flaws; b) the "lag time" hypothesis, and c) the traditional Mediterranean diet and lifestyle. In this manuscript we present and discuss another possible explanation for the Mediterranean paradox related to the higher prevalence and and incidence of stable atheromatous plaques in this area. Full English text available PMID:23485186

Dégano, Irene R; Elosua, Roberto; Kaski, Juan C; Fernández-Bergés, Daniel J; Grau, María; Marrugat, Jaume



Plaque stability and the southern European paradox.  


Differences between European countries in coronary heart disease mortality were initially described in the 20th century, and albeit less dramatic than first reported, these differences remain substantial. Three main hypotheses have been proposed to explain the so-called "Mediterranean paradox": a) underestimation of coronary heart disease mortality due to methodological flaws; b) the "lag time" hypothesis, and c) the traditional Mediterranean diet and lifestyle. In this manuscript we present and discuss another possible explanation for the Mediterranean paradox related to the higher prevalence and and incidence of stable atheromatous plaques in this area. PMID:23078876

Dégano, Irene R; Elosua, Roberto; Kaski, Juan C; Fernández-Bergés, Daniel J; Grau, María; Marrugat, Jaume



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


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



Urothelial Plaque Formation in Post-Golgi Compartments  

PubMed Central

Urothelial plaques are specialized membrane domains in urothelial superficial (umbrella) cells, composed of highly ordered uroplakin particles. We investigated membrane compartments involved in the formation of urothelial plaques in mouse umbrella cells. The Golgi apparatus did not contain uroplakins organized into plaques. In the post-Golgi region, three distinct membrane compartments containing uroplakins were characterized: i) Small rounded vesicles, located close to the Golgi apparatus, were labelled weakly with anti-uroplakin antibodies and they possessed no plaques; we termed them “uroplakin-positive transporting vesicles” (UPTVs). ii) Spherical-to-flattened vesicles, termed “immature fusiform vesicles” (iFVs), were uroplakin-positive in their central regions and contained small urothelial plaques. iii) Flattened “mature fusiform vesicles” (mFVs) contained large plaques, which were densely labelled with anti-uroplakin antibodies. Endoytotic marker horseradish peroxidase was not found in these post-Golgi compartments. We propose a detailed model of de novo urothelial plaque formation in post-Golgi compartments: UPTVs carrying individual 16-nm particles detach from the Golgi apparatus and subsequently fuse into iFV. Concentration of 16-nm particles into plaques and removal of uroplakin-negative membranes takes place in iFVs. With additional fusions and buddings, iFVs mature into mFVs, each carrying two urothelial plaques toward the apical surface of the umbrella cell.

Hudoklin, Samo; Jezernik, Kristijan; Neumuller, Josef; Pavelka, Margit; Romih, Rok



Non-invasive detection of vulnerable coronary plaque  

PubMed Central

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

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




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

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


Plaque Formation by Mumps Virus and Inhibition by Antiserum  

PubMed Central

Boston and ABC strains of mumps virus produced plaques approximately 1.0 mm in diameter in monolayers of BGM cells. The plaques were circular and either clear or target-like in form. Ricki strain virus produced plaques of similar size and form but, in addition, a red plaque was observed with this agent. The vaccine strain of mumps virus, Jeryl Lynn, produced minute clear plaques approximately 0.3 mm in diameter. Incorporation of diethylaminoethyl (DEAE)-dextran into the overlay medium did not affect the size difference between Jeryl Lynn plaques and those of the other strains. However plaques of the Jeryl Lynn and Ricki strains were more easily visualized when the overlay medium contained 400 ?g/ml of DEAE-dextran. Simultaneous titration by plaque formation and roller tube infectivity showed that these two methods were of equal sensitivity. Virus neutralization by antibody was demonstrated by plaque reduction. Rise in antibody titer was observed in sera from human and animal infection, human vaccination, and rabbit immunization. Images

Flanagan, Thomas D.; Barron, Almen L.



Hypoechoic areas on ultrasound images of atheroma are not always diagnostic of fatty plaque  

Microsoft Academic Search

Atherosclerotic plaques in ultrasound (US) images may have bright areas suggestive of fibrous plaque and hypoechoic areas that are often interpreted as fatty plaque. The current study was designed to test the hypothesis that fibrous tissue in atherosclerotic plaques will be hyperechoic or hypoechoic, depending on collagen fiber morphology. Twelve segments of aortic arch containing atherosclerotic plaques obtained from cadavers

Ghasan M. Tabel; Jaroslaw Hepel; Peter Whittaker; Betsy Palal; P. Anthony Chandraratna



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



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

Microsoft Academic Search

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

E Falk



Assessment of plaque assay methods for alphaviruses.  


Viruses from the Alphavirus genus are responsible for numerous arboviral diseases impacting human health throughout the world. Confirmation of acute alphavirus infection is based on viral isolation, identification of viral RNA, or a fourfold or greater increase in antibody titers between acute and convalescent samples. In convalescence, the specificity of antibodies to an alphavirus may be confirmed by plaque reduction neutralization test. To identify the best method for alphavirus and neutralizing antibody recognition, the standard solid method using a cell monolayer overlay with 0.4% agarose and the semisolid method using a cell suspension overlay with 0.6% carboxymethyl cellulose (CMC) overlay were evaluated. Mayaro virus, Una virus, Venezuelan equine encephalitis virus (VEEV), and Western equine encephalitis virus (WEEV) were selected to be tested by both methods. The results indicate that the solid method showed consistently greater sensitivity than the semisolid method. Also, a "semisolid-variant method" using a 0.6% CMC overlay on a cell monolayer was assayed for virus titration. This method provided the same sensitivity as the solid method for VEEV and also had greater sensitivity for WEEV titration. Modifications in plaque assay conditions affect significantly results and therefore evaluation of the performance of each new assay is needed. PMID:23085307

Juarez, Diana; Long, Kanya C; Aguilar, Patricia; Kochel, Tadeusz J; Halsey, Eric S



Carotid plaque, a subclinical precursor of vascular events  

PubMed Central

Background Carotid atherosclerosis is a known biomarker associated with future vascular disease. The risk associated with small, nonstenotic carotid plaques is less clear. The objective of this study was to examine the association between maximum carotid plaque thickness and risk of vascular events in an urban multiethnic cohort. Methods As part of the population-based Northern Manhattan Study, carotid plaque was analyzed among 2,189 subjects. Maximum carotid plaque thickness was evaluated at the cutoff level of 1.9 mm, a prespecified value of the 75th percentile of the plaque thickness distribution. The primary outcome measure was combined vascular events (ischemic stroke, myocardial infarction, or vascular death). Results Carotid plaque was present in 1,263 (58%) subjects. After a mean follow-up of 6.9 years, vascular events occurred among 319 subjects; 121 had fatal or nonfatal ischemic stroke, 118 had fatal or nonfatal myocardial infarction, and 166 died of vascular causes. Subjects with maximum carotid plaque thickness greater than 1.9 mm had a 2.8-fold increased risk of combined vascular events in comparison to the subjects without carotid plaque (hazard ratio, 2.80; 95% CI, 2.04–3.84). In fully adjusted models, this association was significant only among Hispanics. Approximately 44% of the low-risk individuals by Framingham risk score had a 10-year vascular risk of 18.3% if having carotid plaque. Conclusions Maximum carotid plaque thickness is a simple and noninvasive marker of subclinical atherosclerosis associated with increased risk of vascular outcomes in a multiethnic cohort. Maximum carotid plaque thickness may be a simple and nonexpensive tool to assist with vascular risk stratification in preventive strategies and a surrogate endpoint in clinical trials.

Rundek, T.; Arif, H.; Boden-Albala, B.; Elkind, M.S.; Paik, M.C.; Sacco, R.L.



Plaque distribution and vascular remodeling of ruptured and nonruptured coronary plaques in the same vessel: an intravascular ultrasound study in vivo  

Microsoft Academic Search

OBJECTIVESThis study was designed to identify potential differences between the intravascular ultrasound (IVUS) characteristics of spontaneously ruptured and nonruptured coronary plaques.BACKGROUNDThe identification of vulnerable plaques in vivo may allow targeted prevention of acute coronary events and more effective evaluation of novel therapeutic approaches.METHODSIntravascular ultrasound was used to identify 29 ruptured plaques in arteries containing another nonruptured plaque in an adjacent

Clemens von Birgelen; Wolfgang Klinkhart; Gary S Mintz; Alexandra Papatheodorou; Jörg Herrmann; Dietrich Baumgart; Michael Haude; Heinrich Wieneke; Junbo Ge; Raimund Erbel



Artificial plaque removal with Carisolv system: a clinical approach.  


In the present study, removal of artifcial plaque in pits and fissures with the Carisolv system was compared with that of conventional bristle brush methoda in vitro. The results indicate that in the dental clinic, complete plaque removal with the Carisolv is possible, and in addition to acid etching, treated cavity was almost free of debris which might increase sealant retention. PMID:17550047

Yamada, Yoshishige; Hossain, Mozammal; Kimura, Yuichi; Nakamura, Yukio; Masuda, Yoshiko; Shimizu, Yuko; Matsumoto, Koukichi



A Rheolytic System for Percutaneous Coronary and Peripheral Plaque Removal  

Microsoft Academic Search

A method for plaque dissolution has been identified that percutaneously delivers a pulsatile high-velocity stream of saline to the site of an atheromatous lesion within a coronary or peripheral artery. In vitro evaluation and in vivo canine and porcine testing were performed using this 'rheolytic' system to deter mine its feasibility in ablating calcified plaque and soft thrombotic tissue.A prototype

William J. Drasler; Mark L. Jenson; Gregory J. Wilson; Joseph M. Thielen; Emmanuil I. Protonotarios; Robert G. Dutcher; Zinon C. Possis



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



Demonstration of MHC-specific haemolytic plaque-forming cells  

Microsoft Academic Search

IT would be convenient to be able to measure the antibody response to alloantigens of the major histocompatibility complex (MHC) at a cellular level. As MHC alloantigens are expressed on erythrocyte membranes in mice one might suppose that a conventional Jerne plaque assay with enumeration of haemolytic plaque-forming cells (allo-PFC) against a lawn of suitable allogeneic erythrocytes would be straightforward.

Jonathan C. Howard; Jose R. F. Corvalan



No cultural detection of Helicobacter pylori in dental plaque.  


Helicobacter pylori causes human type B gastritis and is involved in the etiology of peptic ulcer disease. The routes of transmission of H. pylori are still unclear. The microorganism may be transmitted orally, since H. pylori has been detected in dental plaques. To confirm the hypothesis that dental plaques are a reservoir of H. pylori, 100 dental plaque specimens from 55 dental surgery patients were incubated on one nonselective and up to four selective agar media for the detection of H. pylori. In addition, urease activity of the plaque material was tested, and the gingival status of the patients was assessed. H. pylori was not cultivated from any of the specimens investigated. Plaque material from 12 patients with moderate and severe gingivitis showed urease activity. The results do not confirm the hypothesis that dental plaques are a relevant reservoir of viable H. pylori cells. However, non-cultivatable forms of H. pylori may survive in dental plaques. Urea cleaving activity of dental plaque may be a marker of gingival inflammation. PMID:7803925

Von Recklinghausen, G; Weischer, T; Ansorg, R; Mohr, C



Aggregative Behavior of Bacteria Isolated from Canine Dental Plaque  

Microsoft Academic Search

Interbacterial adhesion of bacteria isolated from canine dental plaque was assessed by performing a visual coaggregation assay. Using conditions mimicking those likely to be encountered in vivo, the entire cultivable plaque microbiota from a single dog was assessed, and eight (6.7%) unique coaggregation interactions were detected for 120 crosses. Transmission electron microscopy was used to visualize several of the bacteria

David R. Elliott; Michael Wilson; Catherine M. F. Buckley; David A. Spratt



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

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

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


Effect of Oil Pulling on Plaque and Gingivitis  

Microsoft Academic Search

Oil pulling is an age-old process mentioned in Charaka Samhita and Sushratha's Arthashastra. This study was conducted to assess the effect of oil pulling on Plaque and Gingivitis. Objectives: (1) To assess the effect of oil pulling on plaque and gingivitis. (2) To monitor its safety on oral soft and hard tissues. Methodology: 10 subjects performed Oil Pulling along with

HV Amith; Anil V Ankola; L Nagesh


Fluoride in plaque following use of dentifrices containing sodium monofluorophosphate.  


Previous work showed that plaque fluoride increased with increasing NaF content of mouthwashes following daily use. The main aim of this study was to test whether a similar relationship was detectable after regular use of dentifrices containing amounts of sodium monofluorophosphate equivalent to 1000, 1500, and 2500 micrograms F/g. Plaque was collected from three groups, each consisting of approximately 80 children, who had each used one of the dentrifrices for one year. Plaque fluoride increased significantly with increasing Na2FPO3 content of the dentifrices. For the 1000-micrograms-F/g group, plaque fluoride also increased significantly with increasing frequency of dentifrice use, but did not correlate with amount of dentifrice applied per brushing. The inverse correlation observed between mean plaque fluoride concentrations and mean three-year caries increments suggests that oral fluoride measurements may prove valuable in estimating the likely anti-caries efficacy of fluoride-containing dental products. PMID:2918134

Duckworth, R M; Morgan, S N; Burchell, C K



Aortic Arch Plaques and Risk of Recurrent Stroke and Death  

PubMed Central

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

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



Episcleral plaque thermoradiotherapy of posterior uveal melanomas.  


Episcleral plaque radiotherapy is a widely applied treatment for selected patients with uveal melanomas. This treatment is well tolerated but may produce severe late radiation complications resulting in decreased visual acuity that reduces the attractiveness of conservative therapy. The purpose of this study was to access if the addition of episcleral hyperthermia decreases late radiation complications through radiation dose reduction while maintaining high incidence of local tumor control. In a 3-year period, episcleral plaque thermoradiotherapy was given to 25 patients with uveal melanoma in a Phase I study. The mean tumor height was 6.2 mm and the mean tumor basal area was 173 mm(2). The mean radiation dose given to the tumor apex was 72.2 Gy and the mean hyperthermia temperature, given once for 45 min, was 43.5 degrees C. Of the 25 patients treated, 22 (88%) showed tumor height reduction, 2 (8%) showed no change, and 1 (4%) had an increase in tumor height. At the last follow-up (range, 20-68 months; mean, 31.2 months), a 43% mean tumor height reduction was recorded (p = 0.0002). Of the 22 patients initially showing tumor regression, 2 (9%) had subsequent tumor progression. At least ambulatory vision (>5/200) was maintained by 20 (80%) patients. Severe complications, including hemorrhagic retinal detachment and a large vitreous hemorrhage, were seen in 2 (8%) patients early in this Phase I study. The treatment program was well tolerated by the study patients. Severe late treatment toxicity was sharply reduced by limiting the mean scleral temperature to < or equal to 44 degrees C. This study employing 30% lower radiation doses, showed tumor regression in the majority of patients. Longer follow-up is needed to assess long-term treatment efficacy and late treatment complications. PMID:8610652

Petrovich, Z; Pike, M; Astrahan, M A; Luxton, G; Murphree, A L; Liggett, P E



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


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

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



The Vulnerable Plaque: the Real Villain in Acute Coronary Syndromes  

PubMed Central

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

Liang, Michael; Puri, Aniket; Devlin, Gerard



Factors affecting supragingival biofilm composition. I. Plaque mass  

PubMed Central

Objective To examine the relationship between total DNA probe counts of supragingival biofilm samples, clinical parameters and supragingival biofilm composition. Methods Supragingival plaque samples were taken from 187 systemically healthy adult subjects at baseline (N samples = 4,745). All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. The relationship between total DNA probe counts and microbial composition was examined by sub-setting the data into 10 groups based on 10 percentile increments of the total DNA probe counts. Differences among groups in terms of species counts and proportions were sought as well as relationships of total plaque DNA probe count and clinical parameters. Results There was a wide distribution in mean total DNA probe counts among the 187 subjects. With increasing total plaque levels there was a change in the proportions of individual species and microbial complexes. “Small plaques” were characterized by high proportions of species in the yellow, orange, purple and “other” complexes; plaques of moderate mass were characterized by high proportions of Actinomyces and purple complex species, while “large plaques” exhibited increased proportions of green and orange complex species. Measures of gingival inflammation, pocket depth and recession were significantly positively associated with total DNA probe counts. Increased plaque numbers were related to increased pocket depth irrespective of presence or absence of gingival inflammation. Conclusion The proportions of individual species and microbial complexes in supragingival biofilms are influenced by the total numbers of organisms in the biofilm.

Haffajee, A. D.; Teles, R.P.; Patel, M.R.; Song, X.; Veiga, N.; Socransky, S. S.



Collagenolytic activity of dental plaque associated with periodontal pathology.  


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

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



Cell surface hydrophobicity of dental plaque microorganisms in situ.  

PubMed Central

The cell surface hydrophobicity of bacteria obtained directly from human tooth surfaces was assayed by measuring their adherence to liquid hydrocarbons. Fresh samples of supragingival dental plaque were washed and dispersed in buffer. Adherence of the plaque microorganisms to hexadecane, octane, and xylene was tested turbidimetrically and by direct microscopic observation. The results clearly show that the vast majority of bacteria comprising dental plaque exhibit pronounced cell surface hydrophobicity. These data support the hypothesis that hydrophobic interactions play a major role in mediating bacterial adherence on tooth surfaces. Images

Rosenberg, M; Judes, H; Weiss, E



Computer assisted treatment planning for 125I ophthalmic plaque radiotherapy.  


This paper describes a computer program for planning the treatment of ocular tumors with 125I 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 125I 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. PMID:2753765

Ling, C C; Chen, G T; Boothby, J W; Weaver, K; Stuart, A; Barnett, C; Char, D; Phillips, T L



Relationship Between a Systemic Inflammatory Marker, Plaque Inflammation, and Plaque Characteristics Determined by Intravascular Optical Coherence Tomography  

PubMed Central

Objective The purpose of this study was to evaluate the relationships between the peripheral white blood cell (WBC) count, local plaque fibrous cap macrophage density, and the morphological features and presence of thin-cap fibroatheromas (TCFA) identified by optical coherence tomography (OCT). Methods and Results OCT was performed in patients undergoing catheterization. Images were analyzed using validated criteria for plaque characteristics. Baseline WBC count correlated with macrophage density (r=0.483, P<0.001). Both parameters were associated with lipid-rich plaque and correlated inversely with plaque fibrous cap thickness (r=?0.547 for macrophage density and ?0.423 for WBC count, P<0.015). Plaques classified as TCFA had a higher median macrophage density than non-TCFA plaques (7.4 versus 4.99, P<0.001). Patients with TCFA had a higher WBC count compared with those without TCFA (11.0 versus 7.9, P=0.007). Receiver operator curves for WBC count, macrophage density, and these combined parameters for prediction of TCFA showed the area under the curves were 0.88, 0.91, and 0.97 (P<0.001), respectively. Conclusion This study provides the first in vivo data linking the peripheral WBC count, plaque fibrous cap macrophage density, and the characteristics and presence of TCFA. Macrophage density correlated with the WBC count, and both parameters independently and particularly in combination predict the presence of TCFA.

Raffel, O. Christopher; Tearney, Guillermo J.; Gauthier, Denise DeJoseph; Halpern, Elkan F.; Bouma, Brett E.; Jang, Ik-Kyung



Atherosclerotic plaque composition and classification identified by coronary computed tomography: assessment of computed tomography-generated plaque maps compared with virtual histology intravascular ultrasound and histology.  


Background- Computed tomography (CT) is used routinely for coronary angiography, and higher-risk features of plaques can also be identified. However, the ability of CT to discriminate individual plaque components and classify plaques according to accepted histological definitions is unknown. Methods and Results- We first determined CT attenuation ranges for individual plaque components using combined in vivo CT coregistered with virtual histology intravascular ultrasound (VH-IVUS) in 108 plaques from 57 patients. Comparison with contrast attenuation created plaque/contrast attenuation ratios that were significantly different for each component. In a separate validation cohort of 47 patients, these Plaque Maps correlated significantly with VH-IVUS-determined plaque component volumes (necrotic core: r=0.41, P=0.002; fibrous plaque: r=0.54, P<0.001; calcified plaque: r=0.59, P<0.001; total plaque: r=0.62, P<0.001). We also assessed VH-IVUS and CT Plaque Maps against coregistered histology in 72 (VH-IVUS) and 87 (CT) segments from 8 postmortem coronary arteries. The diagnostic accuracy of CT to detect calcified plaque (83% versus 92%), necrotic core (80% versus 65%), and fibroatheroma (80% versus 79%) was comparable with VH-IVUS. However, although VH-IVUS could identify thin-cap fibroatheromas (TCFA) with a diagnostic accuracy of between 74% and 82% (depending on the TCFA definition used), the spatial resolution of CT prevented direct identification of TCFA. Conclusions- CT-derived Plaque Maps based on contrast-adjusted attenuation ranges can define individual plaque components with a similar accuracy to VH-IVUS ex vivo. However, coronary CT Plaque Maps could not reliably classify plaques and identify TCFA, such that high-risk plaques may be misclassified or overlooked. PMID:23960215

Obaid, Daniel R; Calvert, Patrick A; Gopalan, Deepa; Parker, Richard A; Hoole, Stephen P; West, Nick E J; Goddard, Martin; Rudd, James H F; Bennett, Martin R



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

PubMed Central

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



[Methylation profiling of human atherosclerotic plaques].  


Somatic mutation theory of atherogenesis proved by alterations at the DNA level such as "loss of heterozygosity" and microsatellite instability in atherosclerotic plaque is complemented by the date of epigenetic variability of genetic loci involved in the pathological process. However, only recently large-scale analysis of epigenetic modifications in the human genome became possible. For the first time quantitative microarray-based methylation profiling of 1505 CpG-sites across 807 genes was performed in atherosclerotic aorta and carotid artery wall lesions using the GoldenGate Methylation Cancer Panel I ("Illumina", USA). One hundred and three (7%) CpG-sites in 90 (11%) genes were differentially methylated between tissue samples. The most pronounced differences in DNA methylation levels were registered for a site which is located in CpG-island of imprinted gene H19. By comparing 90 genes that were differentially methylated between tissue samples in our study, 10 genes (ICAM1, GSTM1, IGFBP1, POMC, APOA1, IL1RN, INS, LTA, MMP3, THBS2) were overlapped with data in Human Genome Epidemiology Network (HuGENet), in which they were identified as candidates for cardiovascular disease continuum. PMID:21954592

Nazarenko, M S; Puzyrev, V P; Lebedev, I N; Frolov, A V; Barbarash, O L; Barbarash, L S


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:




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




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




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




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



Current status of PET-imaging probes of ?-amyloid plaques.  


Alzheimer's disease (AD) is the most common form of dementia and is characterized by progressive cognitive decline and memory loss. One of pathological hallmarks of AD is the accumulation and deposition of ?-amyloid (A?) plaques which is a potential target for the early diagnosis of AD. Positron emission tomography (PET), a sensitive radionuclide imaging technique, has provided opportunities to detect A? plaques of AD. PET-imaging probes of A? plaques have been extensively developed during the last decade. [(18)F]Florbetapir, the (18)F-labeled PET-imaging probe of A? plaques, was recently approved by US Food and Drug Administration. A number of follow-on PET-imaging probes are currently being developed in academia and pharmaceutical companies. This article will discuss the recent development of PET-imaging probes from [(11)C]PIB to [(18)F]Florbetapir, which are in clinic trials, and several follow-on probes in preclinical stage. PMID:23812777

Koo, Jaehyung; Byun, Youngjoo




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




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



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

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



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



Microsoft Academic Search

PurposeRandall's plaques are common in calcium oxalate (CaOx) stone formers (SF). Plaque coverage correlates directly with urine calcium excretion and inversely with urine volume. We hypothesize that plaque coverage should increase proportionally with increasing stone number. We measured plaque areas in idiopathic CaOx stone formers and nonstone formers (NSF), and identified significant relationships with quantified stone histories.




Urine calcium and volume predict coverage of renal papilla by Randall's plaque  

Microsoft Academic Search

Urine calcium and volume predict coverage of renal papilla by Randall's plaque.BackgroundRenal papillary plaques are common in calcium stone formers. We hypothesized that plaque should increase directly with urine calcium excretion, and inversely with urine volume. To test this, we measured papillary plaque areas in both idiopathic calcium oxalate stone formers and nonstone formers and examined 24-hour urine data to

Ramsay L. Kuo; James E. Lingeman; Andrew P. Evan; Ryan F. Paterson; Joan H. Parks; Sharon B. Bledsoe; Larry C. Munch; Fredric L. Coe



Review How to evaluate plaque vulnerability in animal models of atherosclerosis?  

Microsoft Academic Search

Prevention of heart attack and stroke depends on detection of vulnerable plaques and development of plaque-stabilizing therapies. In turn, progress in diagnostics and treatment is contingent on our understanding of molecular mechanisms of plaque vulnerability. Animal models are essential for testing mechanistic hypotheses in a controlled manner. Currently, there is no single, golden standard animal model of a vulnerable plaque.

Mark D. Rekhter


The role of plaque rupture and thrombosis in coronary artery disease  

Microsoft Academic Search

Atherosclerosis and its thrombotic complications are the major cause of morbidity and mortality in the industrialized world. The progression of atherosclerotic plaques in the coronary circulation is dependent on several risk factors. It is now clear that plaque composition is a major determinant of the risk of subsequent plaque rupture and superimposed thrombosis. The vulnerability of plaques to rupture is

A. G Zaman; G Helft; S. G Worthley; J. J Badimon



Plaque Formation by and Plaque Cloning of Chlamydia trachomatis Biovar Trachoma  

PubMed Central

A new technique for the induction of plaque formation by Chlamydia trachomatis biovar trachoma applicable to the titration of infectivity and cloning of biovar trachoma was established. Three novel strains were cloned and confirmed to be free of glycogen inclusions. The lack of glycogen accumulation correlated with the absence of a 7.5-kb plasmid, which is highly conserved in other strains of C. trachomatis. Although the growth efficiency of these plasmid-free strains was slightly lower than that of plasmid-positive strains, possession of the plasmid and glycogen accumulation were not essential for the survival of C. trachomatis.

Matsumoto, Akira; Izutsu, Hiroshi; Miyashita, Naoyuki; Ohuchi, Masanobu



Persistent edematous-plaque photosensitivity observed with sitagliptin phosphate (Januvia®).  


Photosensitivity to sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, is reported. No previous reports of photosensitivity to any DPP-4 inhibitors are known. Physical examination of the patient revealed edematous plaques confined to sun-exposed areas of the skin. An unusual finding in this case was the spongy sensation upon palpation of the plaques. Histopathology revealed parakeratosis and abundant eosinophils, supporting the clinical impression of cutaneous drug sensitivity. The eruption finally cleared, approximately two years after onset. PMID:22398230

Stricklin, Sherea M; Stoecker, William V; Rader, Ryan K; Hood, Antoinette F; Litt, Jerome Z; Schuman, Thomas P



Senile Plaque Neurites in Alzheimer Disease Accumulate Amyloid Precursor Protein  

Microsoft Academic Search

Senile plaques are polymorphous beta-amyloid protein deposits found in the brain in Alzheimer disease and normal aging. This beta-amyloid protein is derived from a larger precursor molecule of which neurons are the principal producers in brain. We found that amyloid precursor protein (APP)-immunoreactive neurites were involved in senile plaques and that only a subset of these neurites showed markers for

Patrick Cras; Mitsuru Kawai; David Lowery; Patty Gonzalez-Dewhitt; Barry Greenberg; George Perry



Interstellar Message Plaques: Application of White-Light Holography  

Microsoft Academic Search

During Spring \\/ Summer 2001, a prototype white-light holographic interstellar-probe message plaque was created under Contract H-29712D of NASA Marshall Spaceflight Center (MSFC), and commercial white-light holograms were tested for space-radiation tolerance at the MSFC Space Environment Facility (SEF) in Huntsville, AL, USA. Artist C Bangs' message plaque was created at the Center for Holographic Arts in Long Island City,

G. L. Matloff



The Association of Pericardial Fat With Calcified Coronary Plaque  

Microsoft Academic Search

Background:Pericardial fat has a higher secretion of inflammatory cytokines than subcutaneous fat. Cytokines released from pericardial fat around coronary arteries may act locally on the adjacent cells.Objective:We examined the relationship between pericardial fat and calcified coronary plaque.Methods and Procedures:Participants in the community-based Multi-Ethnic Study of Atherosclerosis (MESA) underwent a computed tomography (CT) scan for the assessment of calcified coronary plaque

Jingzhong Ding; Stephen B. Kritchevsky; Tamara B. Harris; Gregory L. Burke; Robert C. Detrano; Moyses Szklo; J. Jeffrey Carr



Effect of rinse with calcium enriched milk on plaque fluid.  


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



Tryptase Promotes Atherosclerotic Plaque Haemorrhage in ApoE-/- Mice  

PubMed Central

Tryptase, the most abundant mast cell (MC) granule protein, plays an important role in atherosclerosis plaque development. To test the hypothesis that tryptase participates directly in atherosclerosis plaque haemorrhage, the gene sequence and siRNA for tryptase were cloned into a lentivirus carrier and atherosclerosis plaque haemorrhage models in ApoE-/- mice were constructed. After a cuffing-cervical artery operation, the mice were randomly divided into 6 groups. Hematoxylin and eosin(HE) staining showed that the cervical artery plaque area was much larger in the tryptase overexpression group compared to the other groups, and there was greater artery stenosis. The artery stenosis from the cuff-side in all groups was more than 90%, except the siRNA group. Tryptase promotes plaque haemorrhage distinctively because 50% of the mice in the tryptase overexpression group had plaque haemorrhage, while only 10% in the siRNA group did. The immunohistochemistry of the cervical artery plaque showed that plasminogen activator inhibitor-1 (PAI-1) expression was the lowest while tissue plasminogen activator (tPA), CD31, CD34 and VEGF was the highest in the tryptase overexpression groups. This observation was completely contrary to what was observed in the siRNA group. Tryptase promoted bEnd.3 cell growth, migration and capillary-like tube formation, which suggests that tryptase can promote microvessel angiogenesis. PAI-1 expression was inhibited, while tPA expression was increased by tryptase in bEnd.3 cells. Our in vivo and in vitro studies suggest that trypase can promote atherosclerotic plaque haemorrhage by promoting angiogenesis and regulating the balance of PAI-1 and tPA. Thus, regulating tryptase expression in MCs may provide a potential target for atherosclerosis treatment.

Tian, Dai; Li, Xiaobo; Ning, Yanxia; Yin, Lianhua



Adiponectin-coated nanoparticles for enhanced imaging of atherosclerotic plaques  

PubMed Central

Background: Atherosclerosis is a leading cause of mortality in the Western world, and plaque diagnosis is still a challenge in cardiovascular medicine. The main focus of this study was to make atherosclerotic plaques visible using targeted nanoparticles for improved imaging. Today various biomarkers are known to be involved in the pathophysiologic scenario of atherosclerotic plaques. One promising new candidate is the globular domain of the adipocytokine adiponectin (gAd), which was used as a targeting sequence in this study. Methods: gAd was coupled to two different types of nanoparticles, namely protamine-oligonucleotide nanoparticles, known as proticles, and sterically stabilized liposomes. Both gAd-targeted nanoparticles were investigated for their potency to characterize critical scenarios within early and advanced atherosclerotic plaque lesions using an atherosclerotic mouse model. Aortic tissue from wild type and apolipoprotein E-deficient mice, both fed a high-fat diet, were stained with either fluorescent-labeled gAd or gAd-coupled nanoparticles. Ex vivo imaging was performed using confocal laser scanning microscopy. Results: gAd-targeted sterically stabilized liposomes generated a strong signal by accumulating at the surface of atherosclerotic plaques, while gAd-targeted proticles became internalized and showed more spotted plaque staining. Conclusion: Our results offer a promising perspective for enhanced in vivo imaging using gAd-targeted nanoparticles. By means of nanoparticles, a higher payload of signal emitting molecules could be transported to atherosclerotic plaques. Additionally, the opportunity is opened up to visualize different regions in the plaque scenario, depending on the nature of the nanoparticle used.

Almer, Gunter; Wernig, Karin; Saba-Lepek, Matthias; Haj-Yahya, Samih; Rattenberger, Johannes; Wagner, Julian; Gradauer, Kerstin; Frascione, Daniela; Pabst, Georg; Leitinger, Gerd; Mangge, Harald; Zimmer, Andreas; Prassl, Ruth



Sensitive detection of tritium in southern blot and plaque hybridizations  

SciTech Connect

A sensitive method for detecting /sup 3/H-labeled probes in Southern blot and plaque hybridizations is described. The method is a combination of dipping nitrocellulose filters in melted Permablend III and preflashing X-ray films. About 10 cpm per band or plaque can be detected after 1 week. This method is used to detect cloned rDNA from Aspergillus nidulans and cloned variant sequences of calf satellite I DNA.

Bartnik, E.; Borsuk, P.; Pieniazek, N.J.



Methotrexate toxicity presenting as cutaneous ulcerations on psoriatic plaques.  


Abstract 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



Molecular MRI of Atherosclerotic Plaque With Targeted Contrast Agents  

PubMed Central

Molecular MRI of atherosclerosis involves the use of novel contrast agents to image cellular and molecular processes within atherosclerotic plaque. Agents to image plaque lipid content, inflammation, angiogenesis, and thrombosis have been developed and studied extensively in animal models of atherosclerosis and vascular injury. Selected agents have also been studied in humans, with highly promising initial results. In this brief review, recent advances as well as opportunities and challenges in the field are discussed.

Sosnovik, David E.; Caravan, Peter



Preliminary study of the detectability of coronary plaque with PET  

NASA Astrophysics Data System (ADS)

The evaluation of coronary plaque vulnerability could be of great diagnostic value in cardiology. Positron emission tomography (PET) is a good candidate due to its ability to quantify micromolar concentrations of targeted drugs. However, the detectability of sub-voxel targets such as coronary plaque is limited by partial volume effects and by cardiorespiratory motion. The goal of this paper is to investigate the impact of these factors in the detectability of plaque uptake. Radioactive markers were implanted on the epicardium of a pig and in vivo scans were performed. This was complemented with phantom measurements to determine the minimum detectable uptake as a function of background activity. Simulations were used to evaluate the effect of cardiorespiratory motion on the reconstructed lesions. Despite cardiorespiratory motion of up to 7 mm, the markers were detectable in the in vivo scans even after the injection of background. A lower limit of 250 Bq was found for a target to be detectable. Motion reduced the contrast of the reconstructed lesions to 23% of their static counterpart. Respiratory gating improved this to 49% of the static value. The results suggest that coronary plaque evaluation with PET is possible, provided that sufficient plaque-to-myocardium uptake contrast (50 to 100) can be achieved. This requirement increases exponentially for lesions with uptake below 250 Bq. The described experiments provide a means of estimating the minimum uptake and contrast required to ensure the detectability of plaque lesions.

Delso, G.; Martinez-Möller, A.; Bundschuh, R. A.; Nekolla, S. G.; Ziegler, S. I.; Schwaiger, M.



Cell culture of Peyronie's disease plaque and normal penile tissue.  


Cell cultures derived from Peyronie's disease plaque and normal penile tissue were characterized morphologically and examined by immunofluorescence for actin cable formation, and their growth properties were compared. Relative to normal penile cell cultures which grew as contact inhibited, poorly refractile fibroblast-like cells, plaque derived cell cultures consisted of round and spindle shaped cells that were more refractile and exhibited random crisscross growth patterns. Scanning electron microscopy of plaque derived cell cultures revealed changes in cell surface topography characterized by the appearance of surface membrane blebs amd microvilli. Transmission electron microscopy demonstrated cells containing organized cytoplasmic microfilament bundles and nuclear indentations which resembled myofibroblasts. Such alterations were less extensive or absent in normal penile cell cultures. The amount and extent of actin cable formation was increased in plaque derived compared to normal penile cell cultures. Plaque derived cells also exhibited differences in growth properties and grew to higher saturation densities than their normal counterparts. These results demonstrate that cells derived from Peyronie's disease plaque can be grown in vitro and that these cells are morphologically altered and have an enhanced proliferative capacity. The availability of these cell cultures will permit studies directed at understanding the etiology and pathogenesis of Peyronie's disease. PMID:7038152

Somers, K D; Dawson, D M; Wright, G L; Leffell, M S; Rowe, M J; Bluemink, G G; Vande Berg, J S; Gleischman, S H; Devine, C J; Horton, C E



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


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


Reproducibility of IVUS Border Detection for Carotid Atherosclerotic Plaque Assessment  

PubMed Central

Plaque composition is a potentially important diagnostic feature for carotid artery stenting (CAS). The purpose of this investigation is to evaluate the reproducibility of manual border correction in intravascular ultrasound with virtual histology (VH IVUS) images. Three images each were obtained from 51 CAS datasets on which automatic border detection was corrected manually by two trained observers. Plaque was classified using the definitions from the CAPITAL (Carotid Artery Plaque Virtual Histology Evaluation) study, listed in order from least to most pathological: no plaque, pathological intimal thickening, fibroatheroma, fibrocalcific, calcified fibroatheroma, thin-cap fibroatheroma, and calcified thin-cap fibroatheroma. Inter-observer variability was quantified using both weighted and unweighted Kappa statistics. Bland-Altman analysis was used to compare the cross-sectional areas of the vessel and lumen. Agreement using necrotic core percentage as the criterion was evaluated using the unweighted Kappa statistic. Agreement between classifications of plaque type was evaluated using the weighted Kappa statistic. There was substantial agreement between the observers based on necrotic core percentage (? = 0.63), while the agreement was moderate (?quadratic = 0.60) based on plaque classification. Due to the time-consuming nature of manual border detection, an improved automatic border detection algorithm is necessary for using VH IVUS as a diagnostic tool for assessing the suitability of patients with carotid artery occlusive disease for CAS.

Siewiorek, Gail M.; Loghmanpour, Natasha A.; Winston, Brion M.; Wholey, Mark H.; Finol, Ender A.



Automatic plaque characterization employing quantitative and multicontrast MRI.  


Multicontrast magnetic resonance imaging (MRI) has shown promise in identifying and characterizing atherosclerotic plaques. One of the limitations of this technique is the lack of a practical automated plaque characterization scheme. In the current study, a prior-information-enhanced clustering (PIEC) technique that utilizes both multicontrast MR images and quantitative T(2) maps is proposed to characterize atherosclerotic plaque components automatically. The PIEC algorithm was assessed on computationally simulated images and multicontrast MRI data of coronary arteries. Multicontrast (T(1)-, T(2)-, partial T(2)-, and proton density-weighted) MR images were acquired from freshly excised human coronary arteries using a 4.7T small-animal scanner. The T(2) distribution for each plaque constituent was measured by exponentially fitting the signal from multiple MR images with different TEs and the same TR. The calculated T(2) distributions were used as the a priori information and combined with the Fuzzy C-Means (FCM)-based clustering algorithm to characterize plaque constituents. The proposed PIEC technique appears to be a promising algorithm for accurate automated plaque characterization. PMID:17969075

Sun, Binjian; Giddens, Don P; Long, Robert; Taylor, W Robert; Weiss, Diana; Joseph, Giji; Vega, David; Oshinski, John N



Plaque disruption and thrombus in Ambrose's angiographic coronary lesion types.  


Lesion eccentricity with irregularities on coronary angiography is associated with ruptured plaques and thrombus based on postmortem and clinical angiographic studies. However, the predictive value of such angiographic markers of plaque disruption and thrombus remains to be determined in vivo. The purpose of this study was to establish whether Ambrose's angiographic coronary lesion types and other angiographic criteria predict the presence of disrupted plaques and thrombus using intracoronary angioscopy. Angioscopy was performed before angioplasty in 60 patients with various coronary syndromes and culprit lesions that were not totally occlusive. Lesions were classified angiographically according to Ambrose's criteria as concentric, type I and II eccentric, and multiple irregularities, or as complex or noncomplex, and then compared with the corresponding angioscopic findings. Disruption and/or thrombus were seen in 17 of 19 type II eccentric lesions and 21 of 23 angiographically complex lesions and had the highest positive predictive value to detect complicated atherosclerotic plaques (type II eccentric lesions: positive predictive value 89%, 95% confidence intervals 67% to 99%; complex lesions: 91%, 95% confidence intervals 72% to 99%). We conclude that Ambrose's type II eccentric stenoses and angiographically complex lesions are strongly associated with disrupted plaques and/or thrombus as assessed by angioscopy in patients and represent unstable plaque substrates. PMID:12842238

Waxman, Sergio; Mittleman, Murray A; Zarich, Stuart W; Fitzpatrick, Philip J; Lewis, Stanley M; Leeman, David E; Shubrooks, Samuel J; Abela, George S; Nesto, Richard W



Animal models of spontaneous plaque rupture: The holy grail of experimental atherosclerosis research  

Microsoft Academic Search

Throughout the history of atherosclerosis research we have sought animal models of the disease process that exhibit high frequencies\\u000a of the features that make human plaque a clinical risk: plaque rupture, mural thrombosis, and intra-plaque hemorrhage. This\\u000a type of model is needed to determine the mechanisms by which plaques rupture and to design and test therapeutic interventions\\u000a for stabilizing plaques.

Michael E. Rosenfeld; Kevin G. S. Carson; Jason L. Johnson; Helen Williams; Christopher L. Jackson; Stephen M. Schwartz



Increased Overnight Fluoride Concentrations in Saliva, Plaque, and Plaque Fluid after a Novel Two-solution Rinse  

Microsoft Academic Search

Recent studies showed that salivary, plaque-fluid, and whole-plaque fluoride were significantly higher 120 min after subjects rinsed with a novel two-solution rinse than after they rinsed with a NaF rinse of the same fluoride concentration. In this study, the persistence of these increases was investigated overnight, a period of time that is more clinically relevant. Improved analytical techniques for the

G. L. Vogel; Y. Mao; C. M. Carey; L. C. Chow



Regional differences in MRI detection of amyloid plaques in AD transgenic mouse brain.  


Our laboratory and others have reported the ability to detect individual Alzheimer's disease (AD) amyloid plaques in transgenic mouse brain in vivo by magnetic resonance imaging (MRI). Since amyloid plaques contain iron, most MRI studies attempting to detect plaques in AD transgenic mouse brain have employed techniques that exploit the paramagnetic effect of iron and have had mixed results. In the present study, using five-way anatomic spatial coregistration of MR images with three different histological techniques, properties of amyloid plaques in AD transgenic mouse brain were revealed that may explain their variable visibility in gradient- and spin-echo MR images. The results demonstrate differences in the visibility of plaques in the cortex and hippocampus, compared to plaques in the thalamus, by the different MRI sequences. All plaques were equally detectable by T(2)SE, while only thalamic plaques were reliably detectable by T(2)*GE pulse sequences. Histology revealed that cortical/hippocampal plaques have low levels of iron while thalamic plaques have very high levels. However, the paramagnetic effect of iron does not appear to be the sole factor leading to the rapid decay of transverse magnetization (short T(2)) in cortical/hippocampal plaques. Accordingly, MRI methods that rely less on iron magnetic susceptibility effect may be more successful for eventual human AD plaque MR imaging, particularly since human AD plaques more closely resemble the cortical and hippocampal plaques of AD transgenic mice than thalamic plaques. PMID:20728546

Wengenack, T M; Reyes, D A; Curran, G L; Borowski, B J; Lin, J; Preboske, G M; Holasek, S S; Gilles, E J; Chamberlain, R; Marjanska, M; Jack, C R; Garwood, M; Poduslo, J F



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


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



Aspirin inhibits human telomerase activation in unstable carotid plaques  

PubMed Central

The activation of telomerase in unstable plaques is an important factor in atherosclerosis, and may be predictive of the risk of cerebrovascular diseases. Human telomerase reverse transcriptase (hTERT) is a subunit of telomerase that is essential for telomerase activation. The aim of the present study was to investigate whether aspirin inhibits the activation of telomerase and hTERT in unstable carotid plaques. Polymorphonuclear neutrophils (PMNs) derived from carotid plaques were isolated from the washing medium of angioplasty balloons, while circulating PMNs, isolated from arterial blood, served as the controls. A polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) enzyme-linked immunosorbent assay (ELISA) was used to measure the telomerase activity in the cells following treatment with aspirin. The mRNA and protein expression of hTERT were detected by a reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis, respectively. The results revealed that the atherosclerotic plaques were positive for telomerase activity, and that aspirin inhibited the telomerase activity of the PMNs derived from the plaques. In addition, aspirin was demonstrated to inhibit the mRNA and protein expression of hTERT through the suppression of hTERT transcriptional activity; however, it had no inhibitory effect on the telomerase activity of the circulating PMNs. Thus, the activation of telomerase in resident PMNs is critical in the instability of carotid plaques. The upregulation of telomerase and hTERT during the progression of atherosclerosis may indicate a role for telomerase in the vascular remodeling that occurs during atherogenesis. Aspirin was demonstrated to inhibit the activation of telomerase via an hTERT-dependent manner in the PMN cells of unstable carotid plaques, and thus hTERT may be considered as a target in the treatment of cerebrovascular diseases.




Radionuclide imaging - A molecular key to the atherosclerotic plaque  

PubMed Central

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

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



Rayleigh mixture model for plaque characterization in intravascular ultrasound.  


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

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



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, PUPA; Abrecth, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; McKenzie, Debbie



Low Copper and High Manganese Levels in Prion Protein Plaques  

PubMed Central

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

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



Multimodal spectroscopy detects features of vulnerable atherosclerotic plaque  

PubMed Central

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.

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



Ultrasound Biomicroscopy for Longitudinal Studies of Carotid Plaque Development in Mice: Validation with Histological Endpoints  

PubMed Central

Atherosclerosis is responsible for the death of thousands of Americans each year. The carotid constriction model of plaque development has recently been presented as a model for unstable plaque formation in mice. In this study we 1) validate ultrasound biomicroscopy (UBM) for the determination of carotid plaque size, percent stenosis, and plaque development in live animals, 2) determine the sensitivity of UBM in detecting changes in blood flow induced by carotid constriction and 3) test whether plaque formation can be predicted from blood flow parameters measured by UBM. Carotid plaques were induced by surgical constriction in Apo E?/? mice. Arteries were imaged bi-weekly by UBM, at which time PW-Doppler measurements of proximal blood flow, as well as plaque length and percent stenosis were determined. Histology was performed 9 weeks post surgery. When compared to whole mount post-mortem measurements, UBM accurately reported carotid plaque length. Percent stenosis, based on transverse B-mode UBM measurements, correlated well with that calculated from histological sections. PW-Doppler revealed that constriction reduced maximum systolic velocity (vmax) and duration of the systolic velocity peak (ts/tt). Pre-plaque (2 week post-surgery) PW-Doppler parameters (vmax and ts/tt) were correlated with plaque length at 9 weeks, and were predictive of plaque formation. Correlation of initiating PW-Doppler parameters (vmax and ts/tt) with resulting plaque length established the degree of flow disturbance required for subsequent plaque development and demonstrated its power for predicting plaque development.

Harmon, Erin Y.; Fronhofer, Van; Keller, Rebecca S.; Feustel, Paul J.; Brosnan, M. Julia; von der Thusen, Jan H.; Loegering, Daniel J.; Lennartz, Michelle R.



SMC-Specific IGF-1 Overexpression in Apoe?/? Mice Does Not Alter Atherosclerotic Plaque Burden but Increases Features of Plaque Stability  

PubMed Central

Objective Growth factors may play a permissive role in atherosclerosis initiation and progression, in part via their promotion of VSMC accumulation in plaques. However, unstable human plaques often have a relative paucity of VSMC which has been suggested to contribute to plaque rupture and/or erosion and to clinical events. IGF-1 is an endocrine and autocrine/paracrine growth factor that is a mitogen for VSMC, but when infused into Apoe?/? mice paradoxically reduces atherosclerosis burden. Methods & Results To determine the effect of stimulation of VSMC growth on atherosclerotic plaque development and to understand mechanisms of IGF-1’s atheroprotective effect we assessed atherosclerotic plaques in mice overexpressing IGF-1 in SMC under the control of the ?SMA promoter, after backcrossing to the Apoe?/? background (SMP8/Apoe?/?). When compared with Apoe?/? mice these SMP8/Apoe?/? mice developed comparable plaque burden after 12 wks on a Western diet, suggesting that the ability of increased circulating IGF-1 to reduce plaque burden was mediated in large part via non-SMC target cells. However, advanced plaques in SMP8/Apoe?/? mice displayed several features of plaque stability, including increased fibrous cap area, ?SMA positive SMC and collagen content and reduced necrotic cores. Conclusion These findings indicate that stimulation of VSMC IGF-1 signaling does not alter total atherosclerotic plaque burden and may improve atherosclerotic plaque stability.

Shai, Shaw-Yung; Sukhanov, Sergiy; Higashi, Yusuke; Vaughn, Charlotte; Kelly, James; Delafontaine, Patrice



Viewpoint: Crosstalks between neurofibrillary tangles and amyloid plaque formation.  


Since its discovery, the hallmarks of Alzheimer's disease (AD) brain have been recognised as the formation of amyloid plaques and neurofibrillary tangles (NFTs). Mounting evidence has suggested the active interplay between the two pathways. Studies have shown that ?-amyloid (A?) can be internalized and generated intracellularly, accelerating NFT formation. Conversely, tau elements in NFTs are observed to affect A? and amyloid plaque formation. Yet the precise mechanisms which link the pathologies of the two brain lesions remain elusive. In this review, we discuss recent evidence that support five putative mechanisms by which crosstalk occurs between amyloid plaque and NFT formation in AD pathogenesis. Understanding the crosstalks in the formation of AD pathologies could provide new clues for the development of novel therapeutic strategies to delay or halt the progression of AD. PMID:22728532

Luan, Kailie; Rosales, Jesusa L; Lee, Ki-Young



A? secretion and plaque formation depend on autophagy.  


Alzheimer's disease (AD) is a neurodegenerative disease biochemically characterized by aberrant protein aggregation, including amyloid beta (A?) peptide accumulation. Protein aggregates in the cell are cleared by autophagy, a mechanism impaired in AD. To investigate the role of autophagy in A? pathology in vivo, we crossed amyloid precursor protein (APP) transgenic mice with mice lacking autophagy in excitatory forebrain neurons obtained by conditional knockout of autophagy-related protein 7. Remarkably, autophagy deficiency drastically reduced extracellular A? plaque burden. This reduction of A? plaque load was due to inhibition of A? secretion, which led to aberrant intraneuronal A? accumulation in the perinuclear region. Moreover, autophagy-deficiency-induced neurodegeneration was exacerbated by amyloidosis, which together severely impaired memory. Our results establish a function for autophagy in A? metabolism: autophagy influences secretion of A? to the extracellular space and thereby directly affects A? plaque formation, a pathological hallmark of AD. PMID:24095740

Nilsson, Per; Loganathan, Krishnapriya; Sekiguchi, Misaki; Matsuba, Yukio; Hui, Kelvin; Tsubuki, Satoshi; Tanaka, Motomasa; Iwata, Nobuhisa; Saito, Takashi; Saido, Takaomi C



An integrated system for the segmentation of atherosclerotic carotid plaque.  


In this paper, we propose and evaluate an integrated system for the segmentation of atherosclerotic plaque in ultrasound imaging of the carotid artery based on normalization, speckle reduction filtering, and four different snakes segmentation methods. These methods are the Williams and Shah, Balloon, Lai and Chin, and the gradient vector flow (GVF) snake. The performance of the four different plaque snakes segmentation methods was tested on 80 longitudinal ultrasound images of the carotid artery using receiver operating characteristic (ROC) analysis and the manual delineations of an expert. All four methods were very satisfactory and similar in all measures evaluated, with no significant differences between them; however, the Lai and Chin snakes segmentation method gave slightly better results. Concluding, it is proposed that the integrated system investigated in this study could be used successfully for the automated segmentation of the carotid plaque. PMID:18046941

Loizou, Christos P; Pattichis, Constantinos S; Pantziaris, Marios; Nicolaides, Andrew



Radiation regression patterns after cobalt plaque insertion for retinoblastoma  

SciTech Connect

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

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



T Cells Specifically Targeted to Amyloid Plaques Enhance Plaque Clearance in a Mouse Model of Alzheimer's Disease  

PubMed Central

Patients with Alzheimer's disease (AD) exhibit substantial accumulation of amyloid-? (A?) plaques in the brain. Here, we examine whether A? vaccination can facilitate the migration of T lymphocytes to specifically target A? plaques and consequently enhance their removal. Using a new mouse model of AD, we show that immunization with A?, but not with the encephalitogenic proteolipid protein (PLP), results in the accumulation of T cells at A? plaques in the brain. Although both A?-reactive and PLP-reactive T cells have a similar phenotype of Th1 cells secreting primarily IFN-?, the encephalitogenic T cells penetrated the spinal cord and caused experimental autoimmune encephalomyelitis (EAE), whereas A? T cells accumulated primarily at A? plaques in the brain but not the spinal cord and induced almost complete clearance of A?. Furthermore, while a single vaccination with A? resulted in upregulation of the phagocytic markers triggering receptors expressed on myeloid cells-2 (TREM2) and signal regulatory protein-?1 (SIRP?1) in the brain, it caused downregulation of the proinflammatory cytokines TNF-? and IL-6. We thus suggest that A? deposits in the hippocampus area prioritize the targeting of A?-reactive but not PLP-reactive T cells upon vaccination. The stimulation of A?-reactive T cells at sites of A? plaques resulted in IFN-?-induced chemotaxis of leukocytes and therapeutic clearance of A?.

Fisher, Yair; Nemirovsky, Anna; Baron, Rona; Monsonego, Alon



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)



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


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

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



Irradiation of malignant eyelid melanoma with iodine 125 plaque  

SciTech Connect

We used contact irradiation with iodine 125 seeds to treat a large, exulcerative, nodular, amelanotic malignant eyelid melanoma with metastasis to the regional lymph nodes in an 80-year-old man. The procedure was similar to iodine 125 plaque irradiation of malignant choroidal melanoma; special equipment, however, was needed to protect the eye from radiation exposure. The response of the malignant eyelid melanoma to iodine 125 plaque irradiation was similar to that of malignant melanomas of the choroid. No complications were observed in a follow-up period of 15 months.

Stanowsky, A.; Krey, H.F.; Kopp, J.; Kanitz, W.; Wagner, T. (Eye Clinic, Central Clinic, Augsburg (West Germany))



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.



Plaque Formation Compared on Surfaces of Stannous Fluoride-Containing and Conventional Amalgams.  

National Technical Information Service (NTIS)

Clinical trials of an amalgam restorative material containing 1.5% sodium fluoride by weight have revealed a definite reduction in plaque formation, perhaps due to the bacteriostatic effect on the organisms within the plaque. This amalgam does not appear ...

A. C. Jerman R. J. Winkworth



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

PubMed Central

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

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



Detection and Therapy of Vulnerable Plaque with Fluorescent and/or Radiolabeled Compositions.  

National Technical Information Service (NTIS)

The present invention relates to methods for selectively targeting Photodynamic Therapy ('PDT') to inflammatory components of vulnerable plaques. As such, the present invention provides methods for the identification of vulnerable plaques, using fluoresce...

A. Fischman A. Tawakol J. Muller M. R. Hamblin T. Hasan



Dendritic Cells in Human Atherosclerosis: From Circulation to Atherosclerotic Plaques  

PubMed Central

Background. Atherosclerosis is a chronic inflammatory disease with atherosclerotic plaques containing inflammatory infiltrates predominantly consisting of monocytes/macrophages and activated T cells. More recent is the implication of dendritic cells (DCs) in the disease. Since DCs were demonstrated in human arteries in 1995, numerous studies in humans suggest a role for these professional antigen-presenting cells in atherosclerosis. Aim. This paper focuses on the observations made in blood and arteries of patients with atherosclerosis. In principal, flow cytometric analyses show that circulating myeloid (m) and plasmacytoid (p) DCs are diminished in coronary artery disease, while immunohistochemical studies describe increased intimal DC counts with evolving plaque stages. Moreover, mDCs and pDCs appear to behave differently in atherosclerosis. Yet, the origin of plaque DCs and their relationship with blood DCs are unknown. Therefore, several explanations for the observed changes are postulated. In addition, the technical challenges and discrepancies in the research field are discussed. Future. Future studies in humans, in combination with experimental animal studies will unravel mechanisms leading to altered blood and plaque DCs in atherosclerosis. As DCs are crucial for inducing but also dampening immune responses, understanding their life cycle, trafficking and function in atherosclerosis will determine potential use of DCs in antiatherogenic therapies.

Van Vre, Emily A.; Van Brussel, Ilse; Bosmans, Johan M.; Vrints, Christiaan J.; Bult, Hidde



Optical coherence tomography for imaging the vulnerable plaque  

PubMed Central

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

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



Effects of Fluoride on the Microbial Ecology of Dental Plaque  

Microsoft Academic Search

In order to survive in a community such as dental plaque, bacteria must be able to resist changes in the environment. These changes may be the result of differences in the host or the activities of the bacteria within the community. Bacteria which cannot resist these environmental pressures may cease metabolism but survive, or be eliminated from the community. Fluoride

G. H. W. Bowden



"MacCallum Plaque of the Heart": A Medicolegal Case  

PubMed Central

Mural endocardial lesions can be seen as MacCallum plaques in rheumatic heart disease. These plaques appear as map-like areas of thickened, roughened, and wrinkled part of the endocardium in the left atrium. Perhaps they are caused by regurgitant jets of blood flow, due to incompetence of the mitral valve. Although MacCallum plaques are one of the characteristic features in rheumatic heart disease, they are very uncommon in recent times. We hereby report a case of an adolescent female with RHD, who was working as a housemaid in a doctor’s house for a few months, and suddenly developed respiratory tract infection and cardiac failure. She died on the fourth day of admission. A medicolegal autopsy was conducted, as her relatives accused her master of sexual assault. On autopsy it was seen that the mitral valves were narrowed, showing multiple vegetations. MacCallum plaque was seen in the dilated left atrium. Hence, it is presented here for educative purposes.

Shivakumarswamy, Udasimath; Sinhasan, Sankappa P.; Purushotham, R.; Nagesha, K. R.



Fluoridated elastomers: Effect on the microbiology of plaque  

Microsoft Academic Search

The objective of this study was to investigate the effect of fluoridated elastomeric ligatures on the microbiology of local dental plaque in vivo. This randomized, prospective, longitudinal, clinical trial had a split-mouth crossover design. The subjects were 30 patients at the beginning of their treatment with fixed orthodontic appliances in the orthodontic departments of the Liverpool and the Sheffield dental

Philip E. Benson; C. W. Ian Douglas; Michael V. Martin



Optical coherence tomography for imaging the vulnerable plaque  

NASA Astrophysics Data System (ADS)

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

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



Toothbrush age and wear as it relates to plaque control.  


An investigation was conducted to test the hypothesis that age and wear of toothbrushes do not affect plaque removal. 40 preclinical dental students between the ages of 19 and 26 years were assigned randomly to 2 groups. 1 group of 19 subjects used a toothbrush for 10 weeks while the 21 subjects in the other group were given new toothbrushes every 2 weeks for 10 weeks. A baseline of zero plaque and calculus was obtained on the first visit. On subsequent visits, 2 weeks apart, the gingival status of each group was evaluated using the gingival index, and plaque levels were scored using the patient hygiene performance index. The brushing surface area of the toothbrushes was measured with a caliper as well as being graded subjectively according to their condition (good, fair or poor). Results were statistically analysed at the end of the 10-week period. It was found that after 10 weeks, the subjects using the same toothbrush for the whole period had significantly more plaque than those who replaced their brushes every 2 weeks. As brushes deteriorated, they became less effective. No differences in gingival state were detected. There was appreciable variation in toothbrush wear among subjects, some reducing their brush to a poor state in 2 weeks whereas with others the brush was rated as "good" after 10 weeks. PMID:3455936

Glaze, P M; Wade, A B



Cellular and molecular players in the atherosclerotic plaque progression.  


Atherosclerosis initiation and progression is controlled by inflammatory molecular and cellular mediators. Cells of innate immunity, stimulated by various endogenous molecules that have undergone a transformation following an oxidative stress or nonenzymatic glycation processes, activate cells of the adaptive immunity, found at the borders of atheromas. In this way, an immune response against endogenous modified antigens takes place and gives rise to chronic low-level inflammation leading to the slow development of complex atherosclerotic plaques. These lesions will occasionally ulcerate, thus ending with fatal clinical events. Plaque macrophages represent the majority of leukocytes in the atherosclerotic lesions, and their secretory activity, including proinflammatory cytokines and matrix-degrading proteases, may be related to the fragilization of the fibrous cap and then to the rupture of the plaque. A considerable amount of work is currently focused on the identification of locally released proinflammatory factors that influence the evolution of the plaque to an unstable phenotype. A better understanding of these molecular processes may contribute to new treatment strategies. Mediators released by the immune system and associated with the development of carotid atherosclerosis are discussed. PMID:22823445

Businaro, Rita; Tagliani, Angela; Buttari, Brigitta; Profumo, Elisabetta; Ippoliti, Flora; Di Cristofano, Claudio; Capoano, Raffaele; Salvati, Bruno; Riganò, Rachele



Link Seen Between Hardening of Arteries, Alzheimer's Plaques  


... enable JavaScript. Link Seen Between Hardening of Arteries, Alzheimer's Plaques Study of patients in their 80s looked ... Preidt Wednesday, October 16, 2013 Related MedlinePlus Pages Alzheimer's Disease Atherosclerosis Seniors' Health WEDNESDAY, Oct. 16 (HealthDay ...



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



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...


Ichthyosiform Large Plaque Parapsoriasis: Report of a Rare Entity  

PubMed Central

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

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



Interstellar Message Plaques: Application of White-Light Holography  

NASA Astrophysics Data System (ADS)

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

Matloff, G. L.



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

Microsoft Academic Search

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

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



Manufacturer's plaque located on north side of south parapet wall, ...  

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

Manufacturer's plaque located on north side of south parapet wall, bridge over little Pince Creek (S.R. 1026, section 002), looking south - Bridge over Little Pine Creek, State Route 1026 over Little Pine Creek, 2.01 kilometers (1.25 miles) East of Bendertown, Jonestown, Columbia County, PA


Impact of artificial plaque composition on drug transport.  


Drug-eluting stent (DES) implantation is a common treatment for atherosclerosis. The safety and efficacy of these devices will depend on the uptake and distribution of drug into the vessel wall. It is established that the composition of atherosclerotic vessels can vary dramatically with patients' age and gender. However, studies focused on elucidating and quantifying the impact of these variations on important drug transport properties, such as diffusion (D) and partition (k) coefficients, are limited. We have developed an improved tissue mimic or artificial plaque to probe the effect of varying concentrations of plaque constituents on drug transport in vitro. Based on these artificial plaques, we have quantified the impact of gelatin (hydrolyzed collagen) and lipid (cholesterol) concentration on D and k using two model drugs, tetracycline and fluvastatin. We found that for tetracycline, increasing the collagen concentration from 0.025 to 0.100 (w/w) resulted in a fivefold decrease in diffusivity, whereas there was no discernible impact on solubility. Increasing the lipid concentration up to 0.034 (w/w) resulted in only minor changes to transport properties of tetracycline. However, fluvastatin exhibited nearly a fivefold increase in k and 10-fold decrease in D with increased lipid concentration. These results were in reasonable agreement with existing models and exhibited behavior consistent with previous observations on drugs commonly used in DES applications. These observations suggest that variations in the chemical characteristics of atherosclerotic plaque can significantly alter the release rate and distribution of drug following DES implantation. PMID:23568279

Guo, Ji; Saylor, David M; Glaser, Ethan P; Patwardhan, Dinesh V



Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque  

SciTech Connect

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

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



Atherosclerotic plaques: is endothelial shear stress the only factor?  


Initiation and development of atherosclerosis has largely been attributed to irregular shear stress patterns and values, in the current literature. Abnormalities such as low shear stress, reversing and oscillatory shear force patterns, as well as temporal variations of shear stress are the most cited factors. However, clinical findings have further indicated that plaques have still been formed and developed in arterial sites that possess relatively more steady and higher shear stresses than those observed in studies correlating low or oscillatory shear stresses with atherosclerosis. These data imply that deviations in shear stress from its normal physiological pattern alone may not be the only factor inducing atherosclerosis, and additional haemodynamics parameter other then shear stress may also contribute to the initiation and development of plaques. In this paper, we hypothesise that the combined effect of wall shear stress and circumferential stress waves, in the form of angular phase difference between the two waves at each cardiac cycle, may be a more accurate determinant of plaque formation and growth. Furthermore, arterial sites that possess more positive values of this angular phase difference may be more prone to plaque formation or development. If proved correct, this theory can transform our understanding of endothelial cell mechanotransduction and mechanobiology, and may lead to design and utilisation of new diagnostic procedures and equipment as predictive and preventive clinical tools for patients with abnormal arterial blood pressure. PMID:23688740

Anssari-Benam, Afshin; Korakianitis, Theodosios



Mechanical and structural characteristics of vulnerable plaques: analysis by coronary angioscopy and intravascular ultrasound  

Microsoft Academic Search

OBJECTIVESMechanical and structural characteristics of vulnerable plaques were evaluated using coronary angioscopy and intravascular ultrasound.BACKGROUNDMechanical stress and composition of plaques play an important role in plaque disruption.METHODSThirty-eight lesions in 38 patients were examined pre-interventionally. The plaques were classified as either yellow or white using coronary angioscopy. Intravascular ultrasound imaging was performed simultaneously with electrocardiographic and intracoronary pressure recordings to calculate

Masamichi Takano; Kyoichi Mizuno; Kentaro Okamatsu; Shinya Yokoyama; Takayoshi Ohba; Shunta Sakai



Segmentation of atherosclerotic carotid plaque in ultrasound video.  


The degree of stenosis of the common carotid artery (CCA) but also the characteristics of the arterial wall including plaque size, composition and elasticity represent important predictors used in the assessment of the risk for future cardiovascular events. This paper proposes and evaluates an integrated system for the segmentation of atherosclerotic carotid plaque in ultrasound video of the CCA based on normalization, speckle reduction filtering (with the hybrid median filter) and parametric active contours. The algorithm is initialized in the first video frame of the cardiac cycle with human assistance and the moving atherosclerotic plaque borders are tracked and segmented in the subsequent frames. The algorithm is evaluated on 10 real CCA digitized videos from B-mode longitudinal ultrasound segments and is compared with the manual segmentations of an expert, for every 20 frames in a time span of 3-5 seconds, covering in general 2 cardiac cycles. The segmentation results are very satisfactory with a true negative fraction (TNF) of 79.3%, a true-positive fraction (TPF) of 78.12%, a false-positive fraction (FPF) of 6.7% and a false-negative fraction (FNF) of 19.6% between the ground truth and the presented plaque segmentations, a Williams index (KI) of 80.3%, an overlap index of 71.5%, a specificity of 0.88±0.09, a precision of 0.86±0.10 and an effectiveness measure of 0.77±0.09. The results show that integrated system investigated in this study could be successfully used for the automated video segmentation of the carotid plaque. PMID:23365830

Loizou, C P; Petroudi, S; Pattichis, C S; Pantziaris, M; Kasparis, T; Nicolaides, A



Development of positron emission tomography ?-amyloid plaque imaging agents.  


For 100 years, ?-amyloid (A?) plaques and neurofibrillary tangles (NFTs) have been recognized as the neuropathological hallmarks of Alzheimer's disease (AD), and their presence or absence could only be assessed postmortem using stains and dyes that identified these microscopic structures. Approximately 10 years ago, the first successful A? plaque-specific positron emission tomography (PET) imaging study was conducted in a living human subject clinically diagnosed with probable AD using the (11)C-labeled radiopharmaceutical Pittsburgh Compound B (PiB). Laboratory studies and preclinical evaluations to design PiB began a decade earlier than the first human PiB PET study and involved chemical modifications of different well-known dyes that bound specifically to the extended ?-pleated sheets that comprise the fibrils of amyloid proteins such as A? plaques, NFTs, ?-synuclein deposits, and prions. These preclinical studies were conducted in our laboratories at the University of Pittsburgh, starting with Congo red derivatives, followed by Chrysamine G derivatives, followed by X-series compounds, and finally with neutral derivatives of thioflavin-T. The in vitro and in vivo evaluations of the different derivatives as candidate PET radioligands for imaging A? plaques and neurofibrillary tangles in human brain are described in this review, along with the specific evaluation criteria by which the candidate radioligands were judged. Out of these studies came PiB, a PET radioligand that binds selectively and with high affinity to only fibrillar forms of A?. PiB has been used in many different human research protocols throughout the world and has demonstrated the usefulness of assessing the A? plaque status of subjects many years before the clinical diagnosis of probable AD. Recently, longer-lived (18)F-radiolabeled A?-selective radiopharmaceuticals have been developed. It is likely that the full clinical impact of these imaging agents will be realized by identifying presymptomatic subjects who would benefit from early drug treatments with future disease-modifying AD therapeutics. PMID:23026364

Mathis, Chester A; Mason, N Scott; Lopresti, Brian J; Klunk, William E



Smooth muscle homeostasis in human atherosclerotic plaques through interleukin 15 signalling  

Microsoft Academic Search

Interleukin (IL)-15 is a cytokine that has a broad tissue distribution and is important in maintaining homeostasis of cells and stability of tissues. When Il-15 is also expressed by vascular smooth muscle cells (SMC), which are the dominant type of cells in most atherosclerotic plaques, it could be important in maintaining plaque tissue integrity and hence resistance of plaques towards

Meer van der J. J; Boer de O. J; P. Teeling; Loos van der C. M; M. C. Dessing; Wal van der A. C



Generation of Equally Sized Particle Plaques Using Solid-Liquid Suspensions  

Microsoft Academic Search

A device is presented for the generation of equally sized plaques of sensitive particles in a 96-well format. The resulting particle plaques can be used for the measurement of adsorption isotherms and uptake kinetics in protein chromatography or for immobilization reactions. The particle plaques are formed from suspensions with a vacuum device that is designed as a reusable sandwich module.

Tim Herrmann; M. Schroder; J. Hubbuch



Differential incorporation of processes derived from different classes of neurons into senile plaques in Alzheimer's disease  

Microsoft Academic Search

The incorporation of neurites into amyloid deposits is an important step in the formation of senile plaques in Alzheimer's disease. It is unknown whether all neuronal types contribute neurites equally to plaques, or whether the processes of certain types are preferentially incorporated. We addressed this question by comparing the incorporation into neocortical plaques of neurites containing the widely distributed neuronal

Laurie A. Adams; David G. Munoz



Relationship between Plaque Assay and Mouse Assay for Titrating Rift Valley Fever Virus.  

National Technical Information Service (NTIS)

A plaque assay method for the small-plaque variant of the pantropic van Wyk strain of Rift Valley fever virus is described. The ease in preparation, the reproducibility of results, the distinctness of the plaques, and the relatively short time required fo...

F. Klein B. G. Mahlandt S. L. Eyler R. E. Lincoln



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

Microsoft Academic Search

Although the plaque assay defines a “gold-standard” for measuring virus infectivity, its reliance on plaque counting limits its sensitivity. When the assay is performed with a liquid overlay, instead of agar overlay, spontaneous flows can promote a uni-directional spread of infection, creating elongated regions of cytopathology that resemble comets. As a model system comet and plaque cultures of vesicular stomatitis

Ying Zhu; John Yin



Methods in Atherosclerotic Plaque Characterization Using Intravascular Ultrasound Images and Backscattered Signals  

Microsoft Academic Search

\\u000a We will review existing supervised as well as unsupervised image- and spectrumderived algorithms in the context of atherosclerotic\\u000a plaque characterization and detection of vulnerable plaques. We will further elaborate more on challenges involved in characterization\\u000a of plaques from tissue preparation, data collection, and registration toward classification.

Amin Katouzian; Stéphane G. Carlier; Andrew F. Laine


Molecular targeting of atherosclerotic plaques by a stabilin-2-specific peptide ligand  

Microsoft Academic Search

Many cells, including macrophages, accumulate in atherosclerotic lesions, destabilizing plaques and driving plaque disruption. Therefore, macrophages serve as useful targets for atherosclerosis treatment and imaging. Stabilin-2 is a transmembrane protein expressed predominantly in macrophages and endothelial cells. In the present study, we found that stabilin-2 was widely expressed in atherosclerotic plaques than in normal vessel walls, and was present not

Ga Young Lee; Jong-Ho Kim; Goo Taeg Oh; Byung-Heon Lee; Ick Chan Kwon; In-San Kim



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

Microsoft Academic Search

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

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



Stable Size Distribution of Amyloid Plaques Over the Course of Alzheimer Disease  

PubMed Central

Amyloid-? plaques are a key pathological feature of Alzheimer disease (AD), but whether plaque sizes increase or stabilize over the course of AD is unknown. We measured the size distribution of total immunoreactive (10D5-positive) and dense-core (Thioflavine-S-positive) plaques in the temporal neocortex of a large group of AD and plaque-bearing age-matched non-demented subjects to test the hypothesis that amyloid plaques continue to grow along with the progression of the disease. The size of amyloid-? (10D5)-positive plaques did not differ between groups whereas dense-core plaques from the AD group were slightly larger than those in the non-demented group (~25%–30%, p = 0.01). Within the AD group, dense-core plaque size did not independently correlate with duration of clinical disease (from 4 to 21 years, p = 0.68), whereas 10D5-positive plaque size correlated negatively with disease duration (p = 0.01). By contrast, an earlier age of symptom onset strongly predicted a larger postmortem plaque size; this effect was independent of disease duration and the presence of the APOE?4 allele (p = 0.0001). We conclude that plaques vary in size among patients, with larger size distributions correlating with an earlier age of onset, but plaques do not substantially increase in size over the clinical course of the disease.

Serrano-Pozo, Alberto; Mielke, Matthew L.; Muzitansky, Alona; Gomez-Isla, Teresa; Growdon, John H.; Bacskai, Brian J.; Betensky, Rebecca A.; Frosch, Matthew P.; Hyman, Bradley T.



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.

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



Study of carotid arterial plaque stress for symptomatic and asymptomatic patients.  


Stroke is one of the leading causes of death in the world, resulting mostly from the sudden ruptures of atherosclerosis carotid plaques. Until now, the exact plaque rupture mechanism has not been fully understood, and also the plaque rupture risk stratification. The advanced multi-spectral magnetic resonance imaging (MRI) has allowed the plaque components to be visualized in-vivo and reconstructed by computational modeling. In the study, plaque stress analysis using fully coupled fluid structure interaction was applied to 20 patients (12 symptomatic and 8 asymptomatic) reconstructed from in-vivo MRI, followed by a detailed biomechanics analysis, and morphological feature study. The locally extreme stress conditions can be found in the fibrous cap region, 85% at the plaque shoulder based on the present study cases. Local maximum stress values predicted in the plaque region were found to be significantly higher in symptomatic patients than that in asymptomatic patients (200 ± 43 kPa vs. 127 ± 37 kPa, p=0.001). Plaque stress level, defined by excluding 5% highest stress nodes in the fibrous cap region based on the accumulative histogram of stress experienced on the computational nodes in the fibrous cap, was also significantly higher in symptomatic patients than that in asymptomatic patients (154 ± 32 kPa vs. 111 ± 23 kPa, p<0.05). Although there was no significant difference in lipid core size between the two patient groups, symptomatic group normally had a larger lipid core and a significantly thinner fibrous cap based on the reconstructed plaques using 3D interpolation from stacks of 2D contours. Plaques with a higher stenosis were more likely to have extreme stress conditions upstream of plaque throat. The combined analyses of plaque MR image and plaque stress will advance our understanding of plaque rupture, and provide a useful tool on assessing plaque rupture risk. PMID:21824619

Gao, Hao; Long, Quan; Kumar Das, Saroj; Halls, Justin; Graves, Martin; Gillard, Jonathan H; Li, Zhi-Yong



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

PubMed Central

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

Slee, A M; O'Connor, J R



Magnetic resonance imaging of amyloid plaques in transgenic mouse models of Alzheimer's disease  

PubMed Central

A major objective in the treatment of Alzheimer's disease is amyloid plaque reduction. Transgenic mouse models of Alzheimer's disease provide a controlled and consistent environment for studying amyloid plaque deposition in Alzheimer's disease. Magnetic resonance imaging is an attractive tool for longitudinal studies because it offers non-invasive monitoring of amyloid plaques. Recent studies have demonstrated the ability of magnetic resonance imaging to detect individual plaques in living mice. This review discusses the mouse models, MR pulse sequences, and parameters that have been used to image plaques and how they can be optimized for future studies.

Chamberlain, Ryan; Wengenack, Thomas M.; Poduslo, Joseph F.; Garwood, Michael; Jack, Clifford R.



Magnetic resonance imaging of amyloid plaques in transgenic mouse models of Alzheimer's disease.  


A major objective in the treatment of Alzheimer's disease is amyloid plaque reduction. Transgenic mouse models of Alzheimer's disease provide a controlled and consistent environment for studying amyloid plaque deposition in Alzheimer's disease. Magnetic resonance imaging is an attractive tool for longitudinal studies because it offers non-invasive monitoring of amyloid plaques. Recent studies have demonstrated the ability of magnetic resonance imaging to detect individual plaques in living mice. This review discusses the mouse models, MR pulse sequences, and parameters that have been used to image plaques and how they can be optimized for future studies. PMID:21499442

Chamberlain, Ryan; Wengenack, Thomas M; Poduslo, Joseph F; Garwood, Michael; Jack, Clifford R



Development of plaque assays for adenoviruses 40 and 41.  


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



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


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



Pleural plaques: a review of diagnostic issues and possible nonasbestos factors.  


The authors reviewed nonasbestos etiologies and diagnostic issues related to pleural plaques. Through searches of PUBMED and DIALOG using the term pleural plaques, they identified 125 articles. The authors found additional references by reviewing citations of these 125 articles. Exposure to nonasbestos agents (eg, erionite, silicates, manmade fibers) was cited as a possible factor in plaque development, although this association was based on limited data; empyema, tuberculosis, rib fractures, and hemothorax also were cited as potential etiologies. Rib companion shadows, fat, intercostal vessels, and muscles can appear as plaques; thus, radiographic diagnosis requires careful evaluation. Chest x-rays show large false negative and varying false positive rates. The terms calcification and thickening often were used as synonymous with plaques; however, these terms have different meanings. The authors concluded that plaques may be associated with nonasbestos exposures and certain medical conditions. Without a thorough exposure/medical history, plaque reports can be misleading. PMID:17867573

Clarke, Chester C; Mowat, Fionna S; Kelsh, Michael A; Roberts, Mark A


Fluoride profiles in dental plaque in vivo formed on fluoride pre-treated human enamel.  


Using a novel device capable of generating plaque in vivo on a natural enamel substrate, it has been possible to determine fluoride profiles from the saliva-plaque interface towards the enamel surface. Fluoride profiles in dental plaques tended to fall from the saliva-plaque interface towards the enamel. The device also offered the possibility of examining fluoride distributions after pre-treatment of the enamel with fluoride in vitro. Fluoride profiles were determined in plaque generated in vivo on enamel surfaces, which had been previously treated with a 900-ppm fluoride solution. The results showed the previously reported fall from the plaque surface, but in addition, a further rise towards the enamel surface was seen. The data imply that enamel loaded with fluoride can release some of this fluoride back into the plaque and may act as a fluoride reservoir. PMID:10867425

Arai, K; Kato, K; Nakagaki, H; Toyama, A; Nagai, N; Noguchi, T; Kirkham, J; Robinson, C; Thuy, T T; Ha, N T


Multiple keratoacanthomas developing in healing plaques of Psoriasis  

PubMed Central

A 22 year old male psoriatic patient presented with multiple reddish scaly plaques all over body. After hematological and biochemical investigations the patient was started on oral methotrexate 15 mg weekly. PASI score at the start of treatment was 26.2. After 3 months PASI dropped to 11.5, the dose of methotrexate was tapered to 7.5mg weekly and the patient was maintained on this dose and kept under monthly follow up. Four months later, the patient presented with reddish to hyperpigmented raised firm nodules having a central crater over the healing plaques of psoriasis. Few lesions showed self resolution over a period of 6-12 weeks. Histopathology of the lesion confirmed it to be Keratoacanthoma. We believe the most likely etiologic factors for the multiple KAs in our patient could be a genetic susceptibility stimulated by multiple causes.

Relhan, Vineet; Sinha, Surabhi; Khurana, Nita; Garg, Vijay K.



The prevention and regression of atherosclerotic plaques: emerging treatments  

PubMed Central

Occlusive vascular diseases, such as sudden coronary syndromes, stroke, and peripheral arterial disease, are a huge burden on the health care systems of developed and developing countries. Tremendous advances have been made over the last few decades in the diagnosis and treatment of atherosclerotic diseases. Intravascular ultrasound has been able to provide detailed information of plaque anatomy and has been used in several studies to assess outcomes. The presence of atherosclerosis disrupts the normal protective mechanism provided by the endothelium and this mechanism has been implicated in the pathophysiology of coronary artery disease and stroke. Efforts are being put into the prevention of atherosclerosis, which has been shown to begin in childhood. This paper reviews the pathophysiology of atherosclerosis and discusses the current options available for the prevention and reversal of plaque formation.

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



Multiple keratoacanthomas developing in healing plaques of Psoriasis.  


A 22 year old male psoriatic patient presented with multiple reddish scaly plaques all over body. After hematological and biochemical investigations the patient was started on oral methotrexate 15 mg weekly. PASI score at the start of treatment was 26.2. After 3 months PASI dropped to 11.5, the dose of methotrexate was tapered to 7.5mg weekly and the patient was maintained on this dose and kept under monthly follow up. Four months later, the patient presented with reddish to hyperpigmented raised firm nodules having a central crater over the healing plaques of psoriasis. Few lesions showed self resolution over a period of 6-12 weeks. Histopathology of the lesion confirmed it to be Keratoacanthoma. We believe the most likely etiologic factors for the multiple KAs in our patient could be a genetic susceptibility stimulated by multiple causes. PMID:23984234

Relhan, Vineet; Sinha, Surabhi; Khurana, Nita; Garg, Vijay K



Local critical stress correlates better than global maximum stress with plaque morphological features linked to atherosclerotic plaque vulnerability: an in vivo multi-patient study  

PubMed Central

Background It is believed that mechanical stresses play an important role in atherosclerotic plaque rupture process and may be used for better plaque vulnerability assessment and rupture risk predictions. Image-based plaque models have been introduced in recent years to perform mechanical stress analysis and identify critical stress indicators which may be linked to rupture risk. However, large-scale studies based on in vivo patient data combining mechanical stress analysis, plaque morphology and composition for carotid plaque vulnerability assessment are lacking in the current literature. Methods 206 slices of in vivo magnetic resonance image (MRI) of carotid atherosclerotic plaques from 20 patients (age: 49–71, mean: 67.4; all male) were acquired for model construction. Modified Mooney-Rivlin models were used for vessel wall and all plaque components with parameter values chosen to match available data. A morphological plaque severity index (MPSI) was introduced based on in vivo plaque morphological characteristics known to correlate with plaque vulnerability. Critical stress, defined as the maximum of maximum- principal-stress (Stress-P1) values from all possible vulnerable sites, was determined for each slice for analysis. A computational plaque stress index (CPSI, with 5 grades 0–4, 4 being most vulnerable) was defined for each slice using its critical stress value and stress interval for each CPSI grade was optimized to reach best agreement with MPSI. Correlations between CPSI and MPSI, plaque cap thickness, and lipid core size were analyzed. Results Critical stress values correlated positively with lipid core size (r = 0.3879) and negatively with cap thickness (r = -0.3953). CPSI classifications had 71.4% agreement with MPSI classifications. The Pearson correlation coefficient between CPSI and MPSI was 0.849 (p < 0.0001). Using global maximum Stress-P1 value for each slice to define a global maximum stress-based CPSI (G-CPSI), the agreement rate with MPSI was only 34.0%. The Pearson correlation coefficient between G-CPSI and MPSI was 0.209. Conclusion Results from this in vivo study demonstrated that localized critical stress values had much better correlation with plaque morphological features known to be linked to plaque rupture risk, compared to global maximum stress conditions. Critical stress indicators have the potential to improve image-based screening and plaque vulnerability assessment schemes.

Tang, Dalin; Teng, Zhongzhao; Canton, Gador; Hatsukami, Thomas S; Dong, Li; Huang, Xueying; Yuan, Chun



Persistent erythematous plaque after minor trauma in an immunocompromised woman.  


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

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



Lectin histochemistry of plaques and tangles in Alzheimer's disease  

Microsoft Academic Search

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

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



A rotational ablation tool for calcified atherosclerotic plaque removal.  


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



Amyloid plaque imaging in vivo: current achievement and future prospects  

Microsoft Academic Search

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

Agneta Nordberg



Sequencing viral genomes from a single isolated plaque  

PubMed Central

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



Experimental determination of circumferential properties of fresh carotid artery plaques.  


Carotid endarterectomy (CEA) is currently accepted as the gold standard for interventional revascularisation of diseased arteries belonging to the carotid bifurcation. Despite the proven efficacy of CEA, great interest has been generated in carotid angioplasty and stenting (CAS) as an alternative to open surgical therapy. CAS is less invasive compared with CEA, and has the potential to successfully treat lesions close to the aortic arch or distal internal carotid artery (ICA). Following promising results from two recent trials (CREST; Carotid revascularisation endarterectomy versus stenting trial, and ICSS; International carotid stenting study) it is envisaged that there will be a greater uptake in carotid stenting, especially amongst the group who do not qualify for open surgical repair, thus creating pressure to develop computational models that describe a multitude of plaque models in the carotid arteries and their reaction to the deployment of such interventional devices. Pertinent analyses will require fresh human atherosclerotic plaque material characteristics for different disease types. This study analysed atherosclerotic plaque characteristics from 18 patients tested on site, post-surgical revascularisation through endarterectomy, with 4 tissue samples being excluded from tensile testing based on large width-length ratios. According to their mechanical behaviour, atherosclerotic plaques were separated into 3 grades of stiffness. Individual and group material coefficients were then generated analytically using the Yeoh strain energy function. The ultimate tensile strength (UTS) of each sample was also recorded, showing large variation across the 14 atherosclerotic samples tested. Experimental Green strains at rupture varied from 0.299 to 0.588 and the Cauchy stress observed in the experiments was between 0.131 and 0.779 MPa. It is expected that this data may be used in future design optimisation of next generation interventional medical devices for the treatment and revascularisation of diseased arteries of the carotid bifurcation. PMID:21497353

Lawlor, Michael G; O'Donnell, Michael R; O'Connell, Barry M; Walsh, Michael T



Susceptibility of microcosm subgingival dental plaques to lethal photosensitization  

Microsoft Academic Search

Photodynamic therapy (PDT) offers potential as a non-invasive treatment of periodontaldisease.Inthisstudy,microcosmbiofilmsweregrownin vitrounder conditions designed to mimic subgingival plaques typically found in patients with periodontitis. To investigate potential PDT modalities, biofilms were exposed to light from a helium\\/neon laser in conjunction with a photosensitizer, toluidine blue O (TBO), at varying output and concentration, respectively. To determine cytotoxic effects, viability profiling was

I. U. Allan; J. F. O'Neill; C. K. Hope



Macrophage Activation in Atherosclerosis: Pathogenesis and Pharmacology of Plaque Rupture  

Microsoft Academic Search

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

J. J. Boyle



Somatostatin immunoreactivity in neuritic plaques of Alzheimer's patients  

Microsoft Academic Search

Senile dementia of the Alzheimer's type can be diagnosed with certainty only by examining neurofibrillary tangles and neuritic plaques under the microscope1-4. Recently, it has been suggested that the condition is linked to specific neurotransmitter systems5, with a decline of cortical acetylcholine, choline acetyl-transferase5-8, cholinergic neurones projecting to the cortex9-11, cortical noradrenaline content12, locus coeruleus neurones13,14 and cortical somatostatic content15.

John H. Morrison; Joseph Rogers; Stephen Scherr; Robert Benoit; Floyd E. Bloom



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



Detection of bacterial DNA in atheromatous plaques by quantitative PCR  

Microsoft Academic Search

This is the first study to analyze atheromatous plaques for the presence of bacterial DNA from ten species, including periodontal species and Chlamydia pneumoniae. We examined 129 samples of DNA extracted from atheromas from 29 individuals for the presence of bacterial 16S rDNA sequences from ten different species: Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans (A.a.), Tannerella forsythensis, Eikenella corrodens, Prevotella intermedia, Staphylococcus

Emil Kozarov; Domenica Sweier; Charles Shelburne; Ann Progulske-Fox; Dennis Lopatin



Sphenoid Wing en plaque meningiomas: Surgical results and recurrence rates  

PubMed Central

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

Simas, Nuno M.; Farias, Joao Paulo



Adherence of plaque components to different restorative materials.  


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

Kawai, K; Urano, M


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


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



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

Microsoft Academic Search

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

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


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




PubMed Central

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

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



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


Acidogenicity and the levels of mutans streptococci (MS) in dental plaque after the use of Lactobacillus rhamnosus GG (LGG) and Lactobacillus reuteri were determined. The study had a randomised, double-blind, crossover design. Thirteen volunteers used tablets containing LGG or a combination of L. reuteri SD2112 and PTA 5289 for 2 weeks. At baseline and at the end of each tablet period, all available supragingival plaque was collected. Lactic acid production was determined from a fixed volume (8 ?l) of fresh plaque and the rest of the plaque was used for culturing MS and lactobacilli. The retention of probiotics to the plaque was assessed using PCR techniques. No probiotic-induced changes were found in the acidogenicity of plaque. Also, MS counts remained at the original level. The number of subjects with lactobacilli in plaque increased in the L. reuteri group (p = 0.011) but not in the LGG group. PCR analysis of plaque revealed the presence of LGG in four and L. reuteri in six subjects after the use of the probiotic. The use of the lactobacilli did not affect the acidogenicity or MS levels of plaque. Short-term consumption of LGG and L. reuteri appeared not to influence the acidogenicity of plaque. PMID:21732090

Marttinen, Aino; Haukioja, Anna; Karjalainen, Sára; Nylund, Lotta; Satokari, Reetta; Öhman, Carina; Holgerson, Pernilla; Twetman, Svante; Söderling, Eva



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


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

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



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.



Generation of C-Reactive Protein and Complement Components in Atherosclerotic Plaques  

PubMed Central

C-reactive protein (CRP) and complement are hypothesized to be major mediators of inflammation in atherosclerotic plaques. We used the reverse transcriptase-polymerase chain reaction technique to detect the mRNAs for CRP and the classical complement components C1 to C9 in both normal arterial and plaque tissue, establishing that they can be endogenously generated by arteries. When the CRP mRNA levels of plaque tissue, normal artery, and liver were compared in the same cases, plaque levels were 10.2-fold higher than normal artery and 7.2-fold higher than liver. By Western blotting, we showed that the protein levels of CRP and complement proteins were also up-regulated in plaque tissue and that there was full activation of the classical complement pathway. By in situ hybridization, we detected intense signals for CRP and C4 mRNAs in smooth muscle-like cells and macrophages in the thickened intima of plaques. By immunohistochemistry we showed co-localization of CRP and the membrane attack complex of complement. We also detected up-regulation in plaque tissue of the mRNAs for the macrophage markers CD11b and HLA-DR, as well as their protein products. We showed by immunohistochemistry macrophage infiltration of plaque tissue. Because CRP is a complement activator, and activated complement attacks cells in plaque tissue, these data provide evidence of a self-sustaining autotoxic mechanism operating within the plaques as a precursor to thrombotic events.

Yasojima, Koji; Schwab, Claudia; McGeer, Edith G.; McGeer, Patrick L.



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)



Elastin and Calcium Rather Than Collagen or Lipid Content Are Associated With Echogenicity of Human Carotid Plaques  

Microsoft Academic Search

Background and Purpose—Echolucent carotid plaques have been associated with increased risk for stroke. Histological studies suggested that echolucent plaques are hemorrhage- and lipid-rich, whereas echogenic plaques are characterized by fibrosis and calcification. This is the first study to relate echogenicity to plaque composition analyzed biochemically. Methods—Echogenicity of human carotid plaques was analyzed by standardized high-definition ultrasound and classified into echolucent,

Isabel Goncalves; Marie W. Lindholm; Luõ ´ s; M. Pedro; Nuno Dias; Gunilla Nordin Fredrikson; Jan Nilsson; Jonatan Moses; Mikko P. S. Ares



No calcium-fluoride-like deposits detected in plaque shortly after a sodium fluoride mouthrinse.  


Plaque 'calcium-fluoride-like' (CaF(2)-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 microg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF(2)-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF(2)-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF(2)-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF(2)-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF(2)-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses. PMID:20185917

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



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

PubMed Central

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

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



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


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



Inhibition of plaque neovascularization reduces macrophage accumulation and progression of advanced atherosclerosis  

NASA Astrophysics Data System (ADS)

Plaque angiogenesis promotes the growth of atheromas, but the functions of plaque capillaries are not fully determined. Neovascularization may act as a conduit for the entry of leukocytes into sites of chronic inflammation. We observe vasa vasorum density correlates highly with the extent of inflammatory cells, not the size of atheromas in apolipoprotein E-deficient mice. We show atherosclerotic aortas contain activities that promote angiogenesis. The angiogenesis inhibitor angiostatin reduces plaque angiogenesis and inhibits atherosclerosis. Macrophages in the plaque and around vasa vasorum are reduced, but we detect no direct effect of angiostatin on monocytes. After angiogenesis blockade in vivo, the angiogenic potential of atherosclerotic tissue is suppressed. Activated macrophages stimulate angiogenesis that can further recruit inflammatory cells and more angiogenesis. Our findings demonstrate that late-stage inhibition of angiogenesis can interrupt this positive feedback cycle. Inhibition of plaque angiogenesis and the secondary reduction of macrophages may have beneficial effects on plaque stability.

Moulton, Karen S.; Vakili, Khashayar; Zurakowski, David; Soliman, Mohsin; Butterfield, Catherine; Sylvin, Erik; Lo, Kin-Ming; Gillies, Stephen; Javaherian, Kashi; Folkman, Judah



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

Microsoft Academic Search

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

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


Characterization of in vivo MRI detectable thalamic amyloid plaques from APP\\/PS1 mice  

Microsoft Academic Search

Amyloid deposits are one of the hallmarks of Alzheimer's disease. Recent studies, in transgenic mice modeling Alzheimer's disease showed that, using in vivo, contrast agent-free, MRI, thalamic amyloid plaques are more easily detected than other plaques of the brain. Our study evaluated the characteristics of these thalamic plaques in a large population of APP\\/PS1, PS1 and C57BL\\/6 mice. Thalamic spots

Marc Dhenain; Nadine El Tannir El Tayara; Ting-Di Wu; Maryvonne Guégan; Andreas Volk; Carmen Quintana; Benoît Delatour



Stationary and high-frequency pulsed electron paramagnetic resonance of a calcified atherosclerotic plaque  

NASA Astrophysics Data System (ADS)

New possibilities of applying high-frequency electron paramagnetic resonance in medicine are demonstrated on an example of the investigation of a calcified atherosclerotic plaque. After the irradiation of the atherosclerotic plaque by x rays, a new type of paramagnetic centers—organomineral radicals—is detected. The spectral and relaxation characteristics of these radicals depend on the calcification degree of the atherosclerotic plaque and can be used for diagnostics.

Abdul'Yanov, V. A.; Galiullina, L. F.; Galyavich, A. S.; Izotov, V. G.; Mamin, G. V.; Orlinskii, S. B.; Rodionov, A. A.; Salakhov, M. Kh.; Silkin, N. I.; Sitdikova, L. M.; Khairullin, R. N.; Chelyshev, Yu. A.




Microsoft Academic Search

The effects of a variety of purine and pyrimidine bases on splenic plaque-forming cells and cellular immunity in mice are presented. The antibody-forming plaque cells were measured in spleens of female C57\\/B1 mice by the Jerne plaque method using sheep red blood cells as the antigen. Bases were given on days 0 and 1 at doses varying from 2 to

AH Chalmers; Mohan M Rao; Villis R Marshall



3D ultrasound analysis of carotid plaque volume and surface morphology  

Microsoft Academic Search

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

A. Fenster; C. Blake; Igor Gyacskov; A. Landry; J. D. Spence



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

Microsoft Academic Search

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

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



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

Microsoft Academic Search

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

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



Inhibition of Acid Production in Dental Plaque Bacteria by Green Tea Catechins  

Microsoft Academic Search

The inhibition of acid production from dental plaque and mutans streptococci by epigallocatechin gallate (EGCg), one of the green tea catechins, was examined. The effect of EGCg solution on dental plaque pH was investigated.Subjects rinsed their mouths with 2 mg\\/ml EGCg solution and then, after 30-min interval, rinsed their mouths with 10% sucrose. Plaque samples were collected at appropriate times

M. Hirasawa; K. Takada; S. Otake



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.

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



Consensus guidelines for the management of plaque psoriasis.  


The Canadian Guidelines for the Management of Plaque Psoriasis were reviewed by the entire National Psoriasis Foundation Medical Board and updated to include newly approved agents such as ustekinumab and to reflect practice patterns in the United States, where the excimer laser is approved for psoriasis treatment. Management of psoriasis in special populations is discussed. In the updated guidelines, we include sections on children, pregnant patients or pregnant partners of patients, nursing mothers, the elderly, patients with hepatitis B or C virus infections, human immunodeficiency virus-infected patients, and patients with malignant neoplasms, as well as sections on tumor necrosis factor blockers, elective surgery, and vaccinations. PMID:22250239

Hsu, Sylvia; Papp, Kim Alexander; Lebwohl, Mark G; Bagel, Jerry; Blauvelt, Andrew; Duffin, Kristina Callis; Crowley, Jeffrey; Eichenfield, Lawrence F; Feldman, Steven R; Fiorentino, David F; Gelfand, Joel M; Gottlieb, Alice B; Jacobsen, Carmen; Kalb, Robert E; Kavanaugh, Arthur; Korman, Neil J; Krueger, Gerald G; Michelon, Melissa A; Morison, Warwick; Ritchlin, Christopher T; Stein Gold, Linda; Stone, Stephen P; Strober, Bruce E; Van Voorhees, Abby S; Weiss, Stefan C; Wanat, Karolyn; Bebo, Bruce F



Risk assessment of atherosclerotic plaques based on global biomechanics.  


We present the results of a computational study of the entire left coronary system simulated both at Newtonian level and at red blood cell resolution for a sizeable number of physiological conditions. We analyze the cardiovascular implications of stenotic plaques and show that the standard clinical criterion for surgical or percutaneous intervention, based on the fractional flow reserve (FFR), is significantly affected by system-dependent, local hemodynamic factors. A refined version, based on the new notion of local FFR response to stenotic growth, and accounting for statistical uncertainties due to flow heterogeneity, is suggested and illustrated. PMID:23490424

Melchionna, Simone; Amati, Giorgio; Bernaschi, Massimo; Bisson, Mauro; Succi, Sauro; Mitsouras, Dimitrios; Rybicki, Frank J



Scanning electron microscopy of growing dental plaque: a quantitative study with different mouth rinses.  


The aim of this study was to quantify the influence of different mouth rinses on dental plaque. Wearing splints with enamel pieces 24 volunteers rinsed with essential oils, amine/stannous fluoride, or chlorhexidine digluconate (0.12%) mouth rinses. After 24, 48, 72, and 96 h the enamel pieces were analyzed by scanning electron microscopy. The counts of cocci and bacilli in different plaque layers and the plaque thickness were almost similar using essential oils and amine/stannous fluoride. These results differed significantly from those of chlorhexidine digluconate mouth rinses. The results for plaque thickness were without significant differences between the groups at any appointment. PMID:23758106

Jentsch, Holger; Mozaffari, Eshan; Jonas, Ludwig



Echogenic carotid artery plaques are associated with vertebral fractures in postmenopausal women with low bone mass.  


Although low bone mass has been associated with atherosclerosis even after adjustment for age, little is known about the association between vertebral fractures and calcified atherosclerotic plaques. Our objective was to investigate whether osteoporotic vertebral fractures are independently related to the prevalence of atherosclerotic carotid plaques in postmenopausal women with low bone mass. We enrolled 195 postmenopausal women with osteopenia or osteoporosis. Bone mineral density and the presence of vertebral fractures were assessed. Intima media thickness and atherosclerotic plaques of the carotid artery were assessed using ultrasonography. Of the 195 subjects in the study, 84 had no plaques and 111 had at least one. The percentage of women with vertebral fractures was significantly higher in subjects with echogenic carotid plaques than in those without (27% vs. 11%, respectively; P < 0.05). However, there was no difference in the prevalence of vertebral fractures between women with echolucent plaques and those without (10.9% vs. 10.7%, respectively; P = nonsignificant). By logistic regression analysis with multivariate adjustment, age (P < 0.01), dyslipidemia (P < 0.05), and the presence of vertebral fracture (P < 0.05) were independent risk factors for echogenic carotid plaques. Osteoporotic vertebral fractures are associated with an increased risk of echogenic atherosclerotic plaques in postmenopausal women with low bone mass. It appears that the high association of echogenic atherosclerotic plaques and vertebral fractures could partially explain why osteoporotic vertebral fractures are linked to increased mortality. PMID:18496724

Kim, Se Hwa; Kim, Yoo Mee; Cho, Mi Ae; Rhee, Yumie; Hur, Kyu Yeon; Kang, Eun Seok; Cha, Bong Soo; Lee, Eun Jig; Lee, Hyun Chul; Lim, Sung Kil



Improved iodine-125 plaque design in the treatment of choroidal malignant melanoma.  

PubMed Central

The use and development of iodine-125 plaque therapy for choroidal malignant melanoma are described. Since 1975 experience has led to changes in plaque design and insertion techniques. Twenty-one patients were irradiated with local episcleral iodine-125 plaques. Three patients required a second plaque for tumour recurrence. Four eyes were enucleated because of continued tumour growth and a further eye was removed because of glaucoma secondary to radiation retinopathy. Two patients (9.5%) died of metastases. The remaining 19 patients are alive and clinically clear of metastases, with a mean follow up time of 73.1 months (range 43-142 months).

Hill, J C; Sealy, R; Shackleton, D; Stannard, C; Korrubel, J; Hering, E; Loxton, C



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

PubMed Central

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

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



Increased Expression of Inhibitor of Apoptosis Proteins in Atherosclerotic Plaques of Symptomatic Patients with Carotid Stenosis  

PubMed Central

Vascular remodeling and atheromatous lesion formation are determined in part by the balance between apoptosis and survival of vascular smooth muscle cells (VSMCs). In the chronic stages, apoptosis of VSMCs in the atherosclerotic plaques contributes to the weakening and potential rupture of the plaque causing pathologies such as acute coronary syndrome. The higher incidence of apoptosis in the plaques of symptomatic than in asymptomatic patients has been demonstrated, but the expression of survival proteins, including the inhibitor of apoptosis proteins (IAPs), has not been thoroughly examined. The aim of this study was to investigate the immunohistochemical expression of cellular inhibitor of apoptosis protein-2 (cIAP2), x-linked inhibitor of apoptosis protein (XIAP), and survivin in normal carotid arteries, and carotid endarterectomy specimens of symptomatic and asymptomatic patients with carotid stenosis. The results demonstrated stronger immunopositivity to smooth muscle myosin heavy chain antigen (SM-MHC) (sm2), proliferating cell nuclear antigen (PCNA), and p50 subunit of NF-?? in the asymptomatic plaques than in symptomatic plaques. Furthermore, there was higher expression of cIAP2, XIAP, and survivin in the symptomatic than in the asymptomatic plaques and this paralleled caspase-3 expression. The increased expression of IAPs in symptomatic plaques could be due to endogenous defense mechanism to protect against the pro-apoptotic effect of the inflammatory stimuli that are released in the plaques. This could be involved in the stabilization of symptomatic atheromatous plaques and may prove a potential therapeutic target.

Moran, Edward P.; Agrawal, Devendra K.



Comparative effects of xylitol- and sucrose-sweetened chew tablets and chewing gums on plaque quantity.  


The effects of chewing gums and chew tablets sweetened with sucrose or xylitol on the quantity and adhesivity of dental plaque were studied with 14 volunteer dental students (mean age 23.2). The subjects participated in a four-phase study in which one of four different test products was used during each period. The 3-d periods were interspaced with 4-d normalization phases. The following four experimental products were tested: chewing gums (CG) and chew tablets (CT), sweetened with sucrose (s) or xylitol (x). The amount of plaque was determined through an automatic planimetric procedure on teeth treated with Dentotest. The total plaque areas before brushing were significantly larger in the CTs group compared with the CTx group. After brushing, the plaque areas remained larger in the CTs group. In the determination of the thick plaque areas, the use of CTx was associated with significantly smaller plaque scores than the use of CTs. In the adhesivity studies CGx consistently yielded the lowest plaque scores, but the differences between x and s were not significant. The comparison between CT and CG suggested that CTx produced significantly smaller plaque scores than CGx before brushing, but not after. This finding was considered to result from the differences involved in the texture and chemical composition between tablets and chewing gums. The present study showed that the use of CGx and CTx was associated with clinically more advantageous plaque effects than the use of corresponding products sweetened with sucrose. PMID:6952539

Rekola, M



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.



Characterization of atherosclerotic plaque depositions by Raman and FTIR imaging.  


Spectroscopy-based imaging techniques can provide useful biochemical information about tissue samples. Here, we employ Raman and Fourier transform infrared (IR) imaging to characterize composition and constitution of atherosclerotic plaques of rabbits, fed with a high cholesterol diet. The results were compared with conventional light microscopy after staining with hematoxylin eosin, and elastica van Gieson. The spectral unmixing algorithm vertex component analysis was applied for data analysis and image reconstruction. IR microscopy allowed for differentiation between lipids and proteins in plaques of full aortic cross sections. Raman microscopy further discriminated cholesterol esters, cholesterol and triglycerides. FTIR and Raman images were recorded at a resolution near 20 micrometer per pixel for a large field of view. High resolution Raman images at 1 micrometer per pixel revealed structural details at selected regions of interest. The intima-media and the lipid-protein ratio were determined in five specimens for quantitation. These results correlate well with histopathology. The described method is a promising tool for easy and fast molecular imaging of atherosclerosis. PMID:23139154

Lattermann, Annika; Matthäus, Christian; Bergner, Norbert; Beleites, Claudia; Romeike, Bernd F; Krafft, Christoph; Brehm, Bernhard R; Popp, Jürgen



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



Aminomalonic acid: identification in Escherichia coli and atherosclerotic plaque.  

PubMed Central

Aminomalonic acid (Ama) has been isolated from proteins of Escherichia coli and human atherosclerotic plaque. The presence of Ama has important biological implications because the malonic acid moiety potentially imparts calcium binding properties to protein. Ama was obtained by anaerobic alkaline hydrolysis and identified by chromatographic behavior, quantitative acid-mediated decarboxylation to glycine, and unambiguous gas chromatographic/mass spectral detection. The chromatographic, chemical, and mass spectral properties of naturally occurring Ama were identical to those of the synthetic compound. Amino acid analysis and GC/mass spectrometry also revealed the presence of beta-carboxyaspartic acid and gamma-carboxyglutamic acid in the base hydrolysate of human atherosclerotic plaque. The ratio of Ama to beta-carboxyaspartic acid to gamma-carboxyglutamic acid was 20:1:10, and the quantity of Ama per 1,000 glycine residues was 0.2. Ama is a relatively unstable, minor amino acid in complex structures such as bacteria or tissues. This may explain why it has escaped detection previously, despite intensive investigation.

Van Buskirk, J J; Kirsch, W M; Kleyer, D L; Barkley, R M; Koch, T H



Comparing measures of reliability for indices of gingivitis and plaque.  


The purpose of this methodological study was to compare methods used to assess reliability for gingival inflammation and plaque. Duplicate examinations were conducted by one examiner on 17 subjects (506 scoring sites), using the gingival index (GI), bleeding points index (BPI), and plaque index (PI). The percentage of agreement, the weighted and unweighted kappa coefficients, and Pearson correlation coefficients were calculated as statistics of reliability for mesial buccal site scores and whole mouth mean scores when appropriate. For mesial buccal sites the respective values of the GI, BPI, and PI for weighted kappas were: 0.47, 0.49, and 0.75; for the correlation coefficients: 0.47, 0.49, and 0.76; for unweighted kappas, 0.39, 0.49, and 0.39; and for percentage of agreement 66.2%, 76.1%, and 51.2%. For whole mouth means the correlation coefficients for the GI, BPI, and PI were 0.87, 0.59, and 0.87, respectively. In conclusion, the most useful statistics in assessing the intraexaminer reliability of a solo examiner in descending order were the weighted kappa coefficient, Pearson correlation coefficient, the unweighted kappa coefficient, and percentage of agreement. PMID:8884641

Spolsky, V W; Gornbein, J A



Plaque neovascularization: defense mechanisms, betrayal, or a war in progress.  


Angiogenesis is induced from sprouting of preexisting endothelial cells leading to neovascularization. Imbalance in the angiogenic and antiangiogenic mediators triggers angiogenesis, which may be physiological in the normal state or pathological in malignancy and atherosclerosis. Physiologic angiogenesis is instrumental for restoration of vessel wall normoxia and resolution inflammation, leading to atherosclerosis regression. However, pathological angiogenesis enhances disease progression, increasing macrophage infiltration and vessel wall thickness, perpetuating hypoxia and necrosis. In addition, thin-walled fragile neovessels may rupture, leading to intraplaque hemorrhage. Lipid-rich red blood cell membranes and free hemoglobin are detrimental to plaque composition, increasing inflammation, lipid core expansion, and oxidative stress. In addition, associated risk factors that include polymorphysms in the haptoglobin genotype and diabetes mellitus may modulate the features of plaque vulnerability. This review will focus on physiological and pathological angiogenesis in atherosclerosis and summarizes the current status of anti-vascular endothelial growth factor (VEGF) therapy, microvascular rarefaction, and possible statin-mediated effects in atherosclerosis neovascularization. PMID:22548565

Moreno, Pedro R; Purushothaman, Meeranani; Purushothaman, K-Raman



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.

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



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



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

PubMed Central

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

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



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)



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


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



Coronary Plaque Quantification by Voxel Analysis: Dual-Source MDCT Angiography Versus Intravascular Sonography  

PubMed Central

OBJECTIVE The purpose of this study was to evaluate a voxel-based analytic technique for quantification of noncalcified coronary artery plaque with intravascular sonography as a standard of reference. SUBJECTS AND METHODS Intravascular sonography and dual-source MDCT angiography prospectively performed on 12 patients resulted in identification of 20 segments containing noncalcified plaque. Four of these segments were used to establish reference measurements of 0.6-mm proximal wall thickness with a 0-HU cutoff between the epicardial fat and outer wall and an individually adjusted threshold for the interface between the wall and lumen. With these data, consecutive circular layers of the outer wall were subtracted from a 3D volume to determine the plaque plus medial layer and the actual plaque volume in the other 16 segments. Accuracy of the voxel technique was assessed by comparing the results with intravascular sonographic findings. RESULTS Both the total plaque burden (plaque plus medial layer) and the actual plaque volume had good concordance with intravascular sonographic findings (49.6 ± 20 mm3 vs 56.7 ± 23.6 mm3, p = 0.076; 26.5 ± 14.8 mm3 vs 30.9 ± 15.3 mm3, p = 0.09). Corresponding correlation coefficients were r = 0.76 and r = 0.79. The method had good reproducibility, the an intraclass correlation coefficients being 0.93 for total plaque burden and 0.90 for actual plaque volume. CONCLUSION Voxel analysis can be used for accurate and reproducible quantification not only of plaque burden but also of actual plaque volume.

Brodoefel, Harald; Burgstahler, Christof; Sabir, Adeel; Yam, Chun-Shan; Khosa, Faisal; Claussen, Claus D.; Clouse, Melvin E.



Beta-carotene enhances plaque detection by fluorescence attenuation in an atherosclerotic rabbit model.  


Improved detection of plaque during cardiovascular procedures could enhance the outcome of diagnosis and therapy. We evaluated a new method to stain plaque using a special intravenous preparation of beta-carotene (beta-C) in an in vivo model. beta-C was used to enhance the absorption coefficient of plaque and decrease the laser-induced fluorescence emission. Using this approach the difference in fluorescence emission was accentuated between normal artery and atherosclerotic plaque. Twenty-nine NZW rabbits were divided into five groups, each receiving a different intervention. This included the administration of beta-C to rabbits on a normal or a high cholesterol diet, with or without endothelial debridement. Aortae were examined grossly, by histology, and relative total fluorescence was detected at 886 sites using 488 nm or 514 nm laser excitation. At 488 nm excitation, unstained plaque attenuated total fluorescence twice as much as normal controls (7.55 +/- 1.46 vs. 15.06 +/- 3.12; P < 0.0001); beta-C stained plaque attenuated total fluorescence 17 times more than normal controls (0.89 +/- 0.29 vs. 15.06 +/- 3.12; P < 0.0001). Total fluorescence from unstained plaque was eight times greater than plaque stained with beta-C (7.55 +/- 1.46 vs. 0.89 +/- 0.29; P < 0.0001). Results obtained using 514 nm excitation were similar. The attenuation effect persisted up to 8 weeks following beta-C administration. Thus, beta-C stained plaque displayed fluorescence attenuation, which suggests that pretreatment with beta-C may greatly enhance plaque detection. This may be useful as a guide during plaque removal procedures. PMID:8366738

Ye, B; Abela, G S



Preliminary in vivo atherosclerotic carotid plaque characterization using the accumulated axial strain and relative lateral shift strain indices  

PubMed Central

In this paper, we explore two parameters or strain indices related to plaque deformation during the cardiac cycle, namely, the maximum accumulated axial strain in plaque and the relative lateral shifts between plaque and vessel wall under in vivo clinical ultrasound imaging conditions for possible identification of vulnerable plaque. These strain indices enable differentiation between calcified and lipidic plaque tissue utilizing a new perspective based on the stiffness and mobility of the plaque. In addition, they also provide the ability to distinguish between softer plaques that undergo large deformations during the cardiac cycle when compared to stiffer plaque tissue. Soft plaques that undergo large deformations over the cardiac cycle are more prone to rupture and to release micro-emboli into the cerebral bloodstream. The ability to identify vulnerable plaque, prone to rupture, would significantly enhance the clinical utility of this method for screening patients. We present preliminary in vivo results obtained from ultrasound radio frequency data collected over 16 atherosclerotic plaque patients before these patients undergo a carotid endarterectomy procedure. Our preliminary in vivo results indicate that the maximum accumulated axial strain over a cardiac cycle and the maximum relative lateral shift or displacement of the plaque are useful strain indices that provide differentiation between soft and calcified plaques.

Shi, Hairong; Mitchell, Carol C; McCormick, Matthew; Kliewer, Mark A; Dempsey, Robert J; Varghese, Tomy



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

Microsoft Academic Search

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

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



Effect of Two Antibacterial Mouth Sprays and Dentifrices on Dental Plaque and Gingivitis in Beagle Dogs  

Microsoft Academic Search

Plaque inhibition by dilute mouth sprays and dentifrices containing benzethonium chloride and chlorhexidine gluconate was compared in beagle dogs. Agents with chlorhexidine gluconate produced less plaque than their benzethonium chloride or placebo counterparts, but the differences were not significant when compared to mean control scores registered during interexperimental recovery periods.

F. H. Compton; G. S. Beagrie; Robert Chernecky; Kirsten Glasser



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



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



Dichotomy in Hedgehog Signaling between Human Healthy Vessel and Atherosclerotic Plaques  

PubMed Central

The major cause for plaque instability in atherosclerotic disease is neoangiogenic revascularization, but the factors controlling this process remain only partly understood. Hedgehog (HH) is a morphogen with important functions in revascularization, but its function in human healthy vessel biology as well as in atherosclerotic plaques has not been well investigated. Hence, we determined the status of HH pathway activity both in healthy vessels and atherosclerotic plaques. A series of 10 healthy organ donor–derived human vessels, 17 coronary atherosclerotic plaques and 24 atherosclerotic carotid plaques were investigated for HH pathway activity. We show that a healthy vessel is characterized by a high level of HH pathway activity but that atherosclerotic plaques are devoid of HH signaling despite the presence of HH ligand in these pathological structures. Thus, a dichotomy between healthy vessels and atherosclerotic plaques with respect to the activation status of the HH pathway exists, and it is tempting to suggest that downregulation of HH signaling contributes to long-term plaque stability.

Queiroz, Karla C S; Bijlsma, Maarten F; Tio, Rene A; Zeebregts, Clark J; Dunaeva, Marina; Ferreira, Carmen V; Fuhler, Gwenny M; Kuipers, Ernst J; Alves, Maria M; Rezaee, Farhad; Spek, C Arnold; Peppelenbosch, Maikel P



Effects of an anticariogenic casein phosphopeptide on calcium diffusion in streptococcal model dental plaques  

Microsoft Academic Search

Casein phosphopeptides (CPP) stabilize amorphous calcium phosphate (ACP) and may be used to localize ACP in dental plaque, maintaining a state of supersaturation with respect to tooth enamel, reducing demineralization and enhancing remineralization. The aim here was to investigate these effects by measuring the effect of CPP–ACP on calcium diffusion in plaque. Using Dibdin’s effusion system, calcium diffusion was measured

R. K. Rose



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

Microsoft Academic Search

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

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



Chlamydia pneumoniae Eradication from Carotid Plaques.Results of an Open, Randomised Treatment Study  

Microsoft Academic Search

Objective: to determine the effect of specific antibiotic treatment with roxithromycin in the eradication of Chlamydia pneumoniae from carotid artery plaques. Design: prospective open randomised treatment study. Patients and methods: we analysed 32 patients (16 females, mean age 70.1±14.7 years) who underwent surgery for the removal of atherosclerotic plaques from carotid arteries. During surgery samples of lingual vein and superior

G Melissano; F Blasi; G Esposito; P Tarsia; L Dordoni; C Arosio; Y Tshomba; L Fagetti; L Allegra; R Chiesa



Regulation of vulnerable plaque development by the heme oxygenase/carbon monoxide system.  


Plaque rupture and luminal thrombosis is the most common cause of coronary occlusion that leads to acute coronary syndromes. High-risk plaques, or vulnerable plaques, are defined as lesions that are prone to rupture, also known as thin cap fibroatheroma (TCFA), or lesions prone to erosion or with calcified cores. This review will focus mainly on the vulnerable plaque, which is thought to be the precursor of the thrombogenic or ruptured plaque. Heme oxygenase 1 (HO-1) protein expression is specifically increased in lesions with a vulnerable plaque phenotype resembling TCFAs and correlates with a rise in expression levels of intimal proinflammatory markers. Data from several human and animal studies imply an important function for HO-1 in the genetic regulation of early, as well as late atherogenesis, and plaque destabilization toward a vulnerable phenotype. Although a direct association between HO-1, vulnerable plaque development, and clinical outcome is for now missing, the correlations that have been reported for HO-1 and coronary artery disease point to a possible link. PMID:20656217

Larsen, Katarína; Cheng, Caroline; Duckers, Henricus J



A Comparative Study of Plaque Acidogenesis in Individuals Residing in Communities with and Without Fluoridated Water.  

National Technical Information Service (NTIS)

The ability of dental plaques to produce acid in response to a sugar rinse in fluoridated and non-fluoridated communities was indirectly evaluated by measuring plaque pH with an antimony electrode attached to a Corning pH meter. One hundred forty-four sev...

L. H. Woolley



A Comparative Study of Plaque Acidogenesis in Individuals Residing in Communities with and Without Fluoridated Water.  

National Technical Information Service (NTIS)

The ability of dental plaques to produce acid in response to a sugar rinse in fluoridated and non-fluoridated communities was indirectly evaluated by measuring plaque pH with an antimony electrode attached to a Corning pH meter. 144 seventh and eighth gra...

L. H. Woolley



Magnetic Resonance Demonstration of Multiple Sclerosis Plaques in the Cervical Cord  

Microsoft Academic Search

Magnetic resonance imaging (MRI) has been shown to be far more sensitive than computed tomography (CT) in the detection of muftiple sclerosis plaques within the brain. Unlike CT, MRI is also able to detect multiple sclerosis in the brainstem and cerebellum. This report is the first description of MRI of multiple sclerosis plaques within the cervical spinal cord. Twenty-one patients

Kenneth R. Maravilla; Jeffrey C. Weinreb; Richard Suss; Ray L. Nunnally


Microbiology and Acid\\/Anion Profiles of Enamel Surface Plaque from an in situ Caries Appliance  

Microsoft Academic Search

The microbiological species and acid\\/anion profiles of the plaque-like material which accumulates on exposed surfaces of enamel sections mounted in the experimental troughs of the previously described in situ caries appliance were studied. Each experiment lasted 1 week and the volunteers’ diet and oral hygiene patterns were unaltered, except that interproximal plaque was allowed to accumulate in an interproximal space

S. L. Creanor; T. W. Macfarlane; D. Mackenzie; D. A. Weetman; R. Strang; K. W. Stephen



Ablation of Uroplakin III Gene Results in Small Urothelial Plaques, Urothelial Leakage, and Vesicoureteral Reflux  

Microsoft Academic Search

Urothelium synthesizes a group of inte- gral membrane proteins called uroplakins, which form two-dimensional crystals (urothelial plaques) covering . 90% of the apical urothelial surface. We show that the ablation of the mouse uroplakin III (UPIII) gene leads to overexpression, defective glycosylation, and abnor- mal targeting of uroplakin Ib, the presumed partner of UPIII. The UPIII-depleted urothelium features small plaques,

Ping Hu; Fang-Ming Deng; Feng-Xia Liang; Chuan-Min Hu; Anna B. Auerbach; Ellen Shapiro; Xue-Ru Wu; Bechara Kachar; Tung-Tien Sun



Bacteriology of Human Experimental Gingivitis: Effect of Plaque and Gingivitis Score  

PubMed Central

The plaque flora isolated from discrete dentogingival sites during a human gingivitis experiment was analyzed as a function of the plaque score and of the gingivitis score. When the gingivitis score was plotted as a function of the plaque score, a nonbleeding gingivitis was associated with a proportional increase in the Actinomyces sp. at the expense of the Streptococcus sp. In particular, the percentage of Actinomyces israelii increased significantly, while the percent Streptococcus sanguis decreased significantly. A. israelii also increased significantly when a bleeding gingivitis developed. When the plaque score was plotted as a function of the gingivitis score, A. israelii increased significantly as the nonbleeding gingivitis developed, but A. viscosus and Bacteroides melaninogenicus increased significantly when the bleeding gingivitis developed. The availability of a sufficient number of plaques with a plaque score of 2.0 permitted the examination of the interrelationship of gingivitis and flora minus the effect of plaque biomass. The bacteriological profile showed that when bleeding occurred, the levels and proportions of A. viscosus and B. melaninogenicus increased significantly. These findings raise the possibility that proportional changes in the gingival plaque flora may uniquely contribute to the development of gingival inflammation in this experimental model.

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



Quantitative Assessment of Coronary Atherosclerotic Plaque Profile by Morphometric Analysis of Angiographic Images  

Microsoft Academic Search

Coronary plaque morphology (simple or complex) has a recognized clinical, pathophys iologic, and prognostic importance, but its routine use is hampered by the subjective and qualitative nature of the assessment. The aim of this study was to assess the feasibility and accuracy of mathematical, objective, operator-independent assessment of plaque morphology, by means of algorithms based on vector and fractal analysis,

Cataldo Palmieri; Marco Paterni Rosa Sicari; Eugenio Picano; Andrea Biagini; Mario Marzilli



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

Microsoft Academic Search

Summary This paper summarizes the results from mechanical testing of atherosclerotic plaques performed in the Cardiovascular Mechanics Laboratory and the Laboratory for Implantable Materials at UMBC. The motivation for our work is that balloon angioplasty, stenting, and roto-ablation are mechanical processes that are designed to permanently alter the shape of an occluded arterial lumen. The mechanisms of permanent plaque deformation

L. D. T. Topoleski; N. V. Salunke



Gingival Reactions Around and Plaque Formation on Resin Composites and Glass-Ionomer Cements  

Microsoft Academic Search

This review covers plaque growth on and gingival reactions adjacent to composite resin and glass-ionomer cement restorations. Despite large variations in surface roughness and chemical composition of the restoratives, no clinically measurable differences in the presence or development of plaque and gingivitis were seen. However, more pronounced signs of subclinical gingivitis adjacent to resin composites, compared with non-filled surfaces, were

J. W. V. Van Dijken; S. Sjostrom



Cerebral Embolism during Carotid Artery Stenting: Role of Carotid Plaque Echolucency  

Microsoft Academic Search

Background: Carotid artery stenting (CAS) is associated with the risk of intraprocedural stroke. A better understanding of specific risk factors could help to improve the procedure and to reduce the overall risk of CAS. We addressed the role of carotid plaque echolucency as potential risk factor for cerebral embolism during CAS. Methods: We prospectively evaluated carotid plaque echolucency by use

Michael Rosenkranz; Oliver Wittkugel; Christian Waiblinger; Götz Thomalla; Anna Krützelmann; Stefanie Havemeister; Hermann Zeumer; Christian Gerloff; Jens Fiehler



Dosimetric calculations and measurements of gold plaque ophthalmic irradiators using iridium-192 and iodine-125 seeds  

Microsoft Academic Search

The dosimetry of ophthalmic plaques designed to hold iridium-192 or iodine-125 seeds is investigated experimentally and by means of a computer model. A phantom for thermoluminescent dosimetry (TLD) which permits measurements to within 2 mm of the plaque surface is described. TLD data are compared with model calculations that take into account the active length of the seeds, anisotropy of

Gary Luxton; Melvin A. Astrahan; Peter E. Liggett; David L. Neblett; Dierdre M. Cohen; Zbigniew Petrovich



The severity of coronary atherosclerosis at sites of plaque rupture with occlusive thrombosis.  


Atherosclerotic plaque rupture with superimposed thrombosis is recognized as the lesion causing greater than 90% of acute myocardial infarctions. To determine the severity of atherosclerosis at the site of plaque rupture, 184 coronary arteries from autopsies of 162 patients who died of acute myocardial infarction were studied. There were 102 men, 72 +/- 10 years old (mean +/- SD), and 60 women, 75 +/- 8 years old. All arteries were dissected from the heart, fixed, decalcified, cut at 2 to 3 mm intervals and processed routinely for histologic examination. A planimeter was used to measure artery, plaque, thrombus and luminal cross-sectional area at the site of plaque rupture with thrombosis in sections projected at x13.8 magnification. At the site of atherosclerotic plaque rupture with superimposed thrombosis, the degree of stenosis due to plaque was: 90 +/- 7% for the right (n = 67), 91 +/- 6% for the left anterior descending (n = 79) and 91 +/- 6% for the left circumflex (n = 38) coronary arteries. Plaque rupture in fatal acute myocardial infarction occurs at sites of severe narrowing (mean 91%, range 67% to 99%). Thus, plaque rupture with thrombosis is unlikely to cause the fatal acute myocardial infarction in patients with mild to moderate coronary stenosis. PMID:2007714

Qiao, J H; Fishbein, M C



Psoriatic Plaques Exhibit Red Autofluorescence that is Due to Protoporphyrin IX  

Microsoft Academic Search

In evaluating the autofluorescence properties of normal and diseased skin we discovered that psoriatic plaques can emit a distinct red fluorescence when illuminated with UVA or blue light. Using a macrospectrofluorometer equipped with a 442 nm excitation laser, a sharp in vivo fluorescence emission peak around 635 nm could be demonstrated within the plaques of 34 of 75 (45%) patients

Robert Bissonnette; Haishan Zeng; David I. McLean; William E. Schreiber; Diane L. Roscoe; Harvey Lui



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


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

Turtola, L O



Shear strain in the adventitial layer of the arterial wall facilitates development of vulnerable plaques  

Microsoft Academic Search

Myocardial infarction and stroke are two of the leading causes of death and primarily triggered by destabilization of atherosclerotic plaques. Fatty streaks are known to develop at sites in the arterial wall where shear stress is low. These fatty streaks can develop into more advanced plaques that are prone to rupture. Rupture leads to thrombus formation, which may subsequently result

T. Idzenga; G. Pasterkamp; C. L. de Korte



Proteomic analysis of differential protein expression in human atherosclerotic plaque progression  

Microsoft Academic Search

In this study, differential protein expression was assessed during human atherosclerotic plaque progression. A multifaceted approach was used in which differential protein expression was studied by two-dimensional (2D) gel electrophoresis and validated in individual patients using western blotting and immunohistochemistry. 2D profiles of whole- mount advanced stable lesions were compared to those of plaques containing a thrombus. Mass spectrometry analysis

Marjo MPC Donners; Monique J Verluyten; Freek G Bouwman; Edwin CM Mariman; Bart Devreese; Frank Vanrobaeys; Jozef van Beeumen; Luc HJM van den Akker; Mat JAP Daemen; Sylvia Heeneman



A new method for analysis of motion of carotid plaques from RF ultrasound images  

Microsoft Academic Search

Motion of carotid artery plaques during the cardiac cycle may contribute to plaque disruption and embolism. We have developed a computerized method that objectively analyzes such motion from a sequence of ultrasound (US) radiofrequency (RF) images. A displacement vector map is obtained by 2-D correlation of local areas in consecutive images. From this map, motion dynamics can be quantified and

Jon Bang; Torbjørn Dahl; Annemarieke Bruinsma; Jon Harald Kaspersen; Toril A Nagelhus Hernes; Hans Olav Myhre



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

Microsoft Academic Search

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

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



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

Microsoft Academic Search

Atherosclerosis and specifically rupture of vulnerable plaques account for 23% of all deaths worldwide, far surpassing both infectious diseases and cancer. In atherosclerosis, macrophages can infiltrate plaques which are often associated with lipid deposits. Photothermal wave imaging is based on the periodic thermal modulation of a sample using intensity modulated light. Intensity modulated light enters the sample and is absorbed

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



Plaque disruption and thrombus in Ambrose’s angiographic coronary lesion types  

Microsoft Academic Search

Lesion eccentricity with irregularities on coronary angiography is associated with ruptured plaques and thrombus based on postmortem and clinical angiographic studies. However, the predictive value of such angiographic markers of plaque disruption and thrombus remains to be determined in vivo. The purpose of this study was to establish whether Ambrose’s angiographic coronary lesion types and other angiographic criteria predict the

Sergio Waxman; Murray A Mittleman; Stuart W Zarich; Philip J Fitzpatrick; Stanley M Lewis; David E Leeman; Samuel J Shubrooks; George S Abela; Richard W Nesto



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

Microsoft Academic Search

The presence of ulceration in carotid artery plaque is an independent risk factor for thromboembolic stroke. However, the associated pathophysiological mechanisms - in particular the mechanisms related to the local hemodynamics in the carotid artery bifurcation - are not well understood. We investigated the effect of carotid plaque ulceration on the local time-varying three-dimensional flow field using computational fluid dynamics

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



Smoking Increases Inflammation and Metalloproteinase Expression in Human Carotid Atherosclerotic Plaques  

Microsoft Academic Search

Objectives: To evaluate the effects of cigarette smoking on the composition of human carotid endarterectomy plaques.Background: Smoking has been recognized as a major risk factor in atherogenesis. It is believed that smoking contributes to the atherosclerotic process and plaque instability in part by increasing the adherence of macrophages to the vessel wall and inducing the release of proteolytic enzymes. However,

Simon Kangavari; Shlomo Matetzky; Prediman K. Shah; Juliana Yano; Kuang-Yuh Chyu; Michael C. Fishbein; Bojan Cercek



Dimethylamino-fluorenes: ligands for detecting ?-amyloid plaques in the brain  

Microsoft Academic Search

Formation of ?-amyloid (A?) plaques in the brain is a major contributing factor in the pathogenesis of Alzheimer’s disease (AD). Detection of A? plaques in the brain will be potentially useful in early diagnosis and monitoring the progression of the disease. A series of novel A? aggregate-specific ligands based on fluorenes, which are simple and rigid tricyclic molecules, are synthesized

Chi-Wan Lee; Mei-Ping Kung; Catherine Hou; Hank F. Kung



Quantifying effect of intraplaque hemorrhage on critical plaque wall stress in human atherosclerotic plaques using three-dimensional fluid-structure interaction models.  


Recent magnetic resonance studies have indicated that intraplaque hemorrhage (IPH) may accelerate plaque progression and play an important role in plaque destabilization. However, the impact of hemorrhage on critical plaque wall stress (CPWS) and strain (CPWSn) has yet to be determined. The objective of this study was to assess the effect of the presence and size of IPH on wall mechanics. The magnetic resonance image (MRI) of one patient with histology-confirmed IPH was used to build eight 3D fluid-structure interaction (FSI) models by altering the dimensions of the existing IPH. As a secondary end point, the combined effect of IPH and fibrous cap thickness (FCT) was assessed. A volume curve fitting method (VCFM) was applied to generate a mesh that would guarantee numerical convergence. Plaque wall stress (PWS), strain (PWSn), and flow shear stress (FSS) were extracted from all nodal points on the lumen surface for analysis. Keeping other conditions unchanged, the presence of intraplaque hemorrhage caused a significant increase (27.5%) in CPWS; reduced FCT caused an increase of 22.6% of CPWS. Similar results were found for CPWSn. Furthermore, combination of IPH presence, reduced FCT, and increased IPH volume caused an 85% and 75% increase in CPWS and CPWSn, respectively. These results show that intraplaque hemorrhage has considerable impact on plaque stress and strain conditions and accurate quantification of IPH could lead to more accurate assessment of plaque vulnerability. Large-scale studies are needed to further validate our findings. PMID:23363206

Huang, Xueying; Yang, Chun; Canton, Gador; Ferguson, Marina; Yuan, Chun; Tang, Dalin



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



MRI Features of the Disruption-Prone and the Disrupted Carotid Plaque: A Pictorial Essay  

PubMed Central

Stroke is a leading cause of long-term disability and is the third most common cause of death in the United States and western countries. Twenty percent of strokes are thought to arise from the carotid artery. Histopathological studies have suggested that plaque disruption is a key factor in the etiology of carotid-related ischemic events. Features associated with plaque disruption include intraplaque hemorrhage, large necrotic cores with thin overlying fibrous caps, plaque neovasculature and inflammatory cell infiltrate. In vivo high-spatial resolution, multi-contrast weighted magnetic resonance imaging (MRI) has been extensively evaluated using histology as the gold standard, and has documented reliability in the identification of these key carotid plaque features. In this pictorial essay, we illustrate the capability of MRI for identifying features of disruption-prone and disrupted atherosclerotic carotid plaques.

Chu, Baocheng; Ferguson, Marina S.; Chen, Huijun; Hippe, Daniel S.; Kerwin, William S.; Canton, Gador; Yuan, Chun; Hatsukami, Thomas S.



Intraplaque Stretch in Carotid Atherosclerotic Plaque - an Effective Biomechanical Predictor for Subsequent Cerebrovascular Ischemic Events  

PubMed Central

Background Stretch is a mechanical parameter, which has been proposed previously to affect the biological activities in different tissues. This study explored its utility in determining plaque vulnerability. Methods One hundred and six patients with mild to moderate carotid stenosis were recruited in this study (53 symptomatic and 53 asymptomatic). High resolution, multi-sequence magnetic resonance (MR) imaging was performed to delineate various plaque components. Finite element method was used to predict high stretch concentration within the plaque. Results During a two-year follow-up, 11 patients in symptomatic group and 3 in asymptomatic group experienced recurrent cerebrovascular events. Plaque stretch at systole and stretch variation during one cardiac cycle was greater in symptomatic group than those in the asymptomatic. Within the symptomatic group, a similar trend was observed in patients with recurrent events compared to those without. Conclusion Plaques with high stretch concentration and large stretch variation are associated with increased risk of future cerebrovascular events.

Wang, Wenkai; Bahaei, Nasim S.; Chen, Shengyong; Young, Victoria E.; Graves, Martin J.; Gillard, Jonathan H.



Fibronectin-degrading activity in human crevicular fluid, gingival explants culture medium and bacterial plaques.  


125I-fibronectin was incubated with extracts having presumably a proteolytic activity. Plaque from children without gingivitis, plaque from adults with chronic periodontitis, human gingival fluid and pooled culture media of human gingival explants were studied. Proteolysis was usually faster with plaque from patients with adult periodontitis than with plaque from children without gingivitis and the inhibition tests showed that several enzymes were implicated in the process. For the culture medium of gingival explants, the electrophoretic profile of the digestion products of fibronectin was different and showed a decreased activity. Nevertheless the gingival fluid gave a very similar degradation to bacterial plaque. The sulcular content was able to assume enzymatic activity capable of destroying fibronectin. These sulcular activities could be important for bacterial colonisation of sulcular surfaces and perhaps also for fibronectin destruction of periodontal tissues. PMID:3049569

Pellat, B; Planchenault, T; Keil-Dlouha, V; Pellerin, C



Effect of Pomegranate Juice on Dental Plaque Microorganisms (Streptococci and Lactobacilli)  

PubMed Central

To study the effect of pomegranate juice on dental plaque microorganisms. A clinical trial was conducted on thirty healthy volunteers aged 25-30 years who visited Out Patient Department (OPD) of Bapuji Dental College and Hospital, Davangere during the month of October 2006. Before conducting the study, thorough oral prophylaxis was done and the subjects were asked to refrain from the oral hygiene procedures for 24 hrs. Dental plaque was collected from each subject, before and after rinsing 30ml of pomegranate juice without sugar. Plaque samples were cultured using Mitis Salivarius Agar and Rogosa SL Agar media. Wilcoxon's signed rank test was used for statistical analysis. Results showed that pomegranate rinse was effective against dental plaque microorganisms. There was a significant reduction in the number of colony forming units of streptococci (23%) and lactobacilli (46%). The ruby red seeds may be a possible alternative for the treatment of dental plaque bacteria.

Kote, Sowmya; Kote, Sunder; Nagesh, Lakshminarayan



Use of the plaque assay for testing the antibiotic susceptibility of intracellular bacteria.  


The plaque assay was first described for titration of bacterial inoculums and clonal isolation, and was later adapted for testing antibiotics susceptibility and to study virulence factors and motility of bacteria. Over time, the sensitivity and reproducibility of the technique has been improved. Usually, the number of plaques is counted; however, the recent development of informatics tools has stimulated interest in the quantification of plaque size. Owing to this new approach, the plaque assay has been used to characterize the host cell response when infected cells are treated with antimicrobial agents. It was found that statins prevented cell lesions following rickettsial infection; in other studies, some antibiotics were found to cause apoptosis of host cells, suggesting a toxic activity. Here, we present an overview of the plaque assay as it has been used to investigate intracellular bacteria. PMID:24059920

Edouard, Sophie; Raoult, Didier



Differentiation of Temperature Variants of Influenza A2 Viruses on the Basis of Plaque Formation  

PubMed Central

The ability of temperature variants of influenza A2 virus to produce plaques in chick embryo kidney tissue culture was studied at different temperatures. Definite differences in efficiency of plaque formation by cryophilic and thermophilic strains were observed at low and high temperatures. Differentiation of the temperature variants appears to reside in a number of genetic markers, designated rct-40, rct-28, and plaque size (S). Virulence of influenza A2 virus, enhanced after prolonged cultivation at high temperature, is probably related to its greater efficiency of plating at 40 C (rct-40+), formation of larger plaques at optimal (36 C) and high (40 C) temperatures, and to loss of ability to form plaques at 28 C (rct-28?). Images

Medvedeva, T. E.; Alexandrova, G. I.; Smorodintsev, A. A.



Role of thrombosis in the onset, progression and obstructive character of coronary atherosclerotic plaques.  


A study was carried out on the role of successive microthrombi incorporation and intramural thrombi formation in the onset, progression and obstructive character of coronary atherosclerotic plaques. The coronary arterial tree of 836 apparently healthy subjects 1 to 50 years old who died of accidental causes was investigated. The onset of coronary atherosclerotic plaques having as precursors thrombi could be detected in 10% of advanced lesions. The left anterior descending artery appeared as the vessel of the coronary arterial tree the most susceptible to plaque development induced by thrombi and to the occurrence of thrombi on preexisting plaques. This occurrence of thrombi on preexisting plaques was recorded in 48% of subjects aged 46 to 50 years and was followed by a severe luminal narrowing in the major coronary arteries. PMID:2749156

Velican, C; Velican, D; Petrescu, C


The tar fraction of cigarette smoke does not promote arteriosclerotic plaque development.  

PubMed Central

In addition to being the single greatest known environmental cause of cancer, cigarette smoke (CS) is also a major contributor to heart disease. We reported previously that 1) inhalation of either mainstream or sidestream CS promotes aortic arteriosclerotic plaque development; 2) 1,3 butadiene, a vapor-phase component of CS, promotes plaque development at 20 ppm, which at the time was only 2 times higher than the threshold limit value; and 3) individual tar fraction carcinogens in CS, including polynuclear aromatic hydrocarbons (PAHs) and nitrosamines, either do not promote plaque development or do so only at high concentrations. These results suggested that the tar fraction is not the primary source of plaque-promoting agents in CS. We asked whether repeated exposure to the tar fraction of CS, collected in a cold trap (TAR), promotes plaque development in an avian model of arteriosclerosis. Acetone extracts of mainstream CS tar from burning, unfiltered reference cigarettes were solubilized in dimethyl sulfoxide (DMSO) and injected weekly into cockerels for 16 weeks (25 mg/kg/week). Positive controls were injected weekly with the synthetic PAH carcinogen, 7,12 dimethylbenz(a)anthracene (DMBA) dissolved in DMSO and negative controls were injected with DMSO. Plaque location and prevalence did not differ from group to group. Morphometric analysis of plaque cross-sectional areas showed that plaque sizes, which are log-normally distributed, were significantly larger in the DMBA cockerels compared to both the TAR and DMSO groups. There were no significant differences in plaque size between DMSO and TAR cockerels. The results reported here, combined with other recent findings, support the conclusion that the primary arteriosclerotic plaque-promoting components of CS are in the vapor phase. Images Figure 1. Figure 2.

Penn, A; Keller, K; Snyder, C; Nadas, A; Chen, L C



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

PubMed Central

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



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)



Verrucous plaque on the back of a hand.  


We report the case of a 44-year-old slaughter-house operator with a skin lesion that had been present for two years on the back of his left hand. The lesion had increased progressively in size despite numerous topical treatments. Physical examination revealed an infiltrated erythematous-violet plaque with a verrucous surface featuring numerous orifices draining purulent material. Histologic study of the lesion disclosed tuberculoid granulomatous infiltrates at the dermoepidermal limit. Presence of Mycobacterium tuberculosis, together with other epidemiologic, clinical, histologic, and immunologic data, permitted a diagnosis of tuberculosis verrucosa cutis to be made. The excellent response of the patient to treatment confirmed this hypothesis. However, polychemotherapy withdrawal was temporarily needed due to analytical abnormalities. PMID:9403240

Hernández-Martín, A; Fernández-López, E; Román, C; de Unamuno, P; Armijo, M



Review of diagnostic plaque reduction neutralization tests for flavivirus infection.  


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

Maeda, Akihiko; Maeda, Junko



Bacterial diversity of subgingival plaque in 6 healthy Chinese individuals.  


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



Electrochemical Impedance Spectroscopy to Characterize Inflammatory Atherosclerotic Plaques  

PubMed Central

Despite advances in diagnosis and therapy, atherosclerotic cardiovascular disease remains the leading cause of morbidity and mortality in the Western world. Predicting metabolically active atherosclerotic lesions has remained an unmet clinical need. We hereby developed an electrochemical strategy to characterize the inflammatory states of high-risk atherosclerotic plaques. Using the concentric bipolar microelectrodes, we sought to demonstrate distinct Electrochemical Impedance Spectroscopic (EIS) measurements for unstable atherosclerotic plaques that harbored active lipids and inflammatory cells. Using equivalent circuits to simulate vessel impedance at the electrode-endoluminal tissue interface, we demonstrated specific electric elements to model working and counter electrode interfaces as well as the tissue impedance. Using explants of human coronary, carotid, and femoral arteries at various Stary stages of atherosclerotic lesions (n = 15), we performed endoluminal EIS measurements (n = 147) and validated with histology and immunohistochemistry. We computed the vascular tissue resistance using the equivalent circuit model and normalized the resistance to the lesion-free regions. Tissue resistance was significantly elevated in the oxLDL-rich thin-cap atheromas (1.57±0.40, n = 14, p < 0.001) and fatty streaks (1.36±0.28, n = 33, p < 0.001) as compared with lesion-free region (1.00±0.18, n = 82) or oxLDL-absent fibrous atheromas (0.86±0.30, n = 12). Tissue resistance was also elevated in the calcified core of fibrous atheroma (2.37±0.60, n = 6, p < 0.001). Despite presence of fibrous structures, tissue resistance between ox-LDL-absent fibroatheroma and the lesion-free regions was statistically insignificant (0.86±0.30, n = 12, p > 0.05). Hence, we demonstrate that the application of EIS strategy was sensitive to detect fibrous cap oxLDL-rich lesions and specific to distinguish oxLDL-absent fibroatheroma.

Yu, Fei; Dai, Xiaohu; Beebe, Tyler; Hsiai, Tzung



Intraplaque haemorrhages as the trigger of plaque vulnerability.  


Atherothrombosis remains one of the main causes of morbidity and mortality in the western countries. Human atherothrombotic disease begins early in life in relation to circulating lipid retention in the inner vascular wall. Risk factors enhance the progression towards clinical expression: dyslipidaemia, diabetes, smoking, hypertension, ageing, etc. The evolution from the initial lipid retention in the arterial wall to clinical events is a continuum of increasingly complex biological processes. Current strategies to fight the consequences of atherothrombosis are orientated either towards the promotion of a healthy life style and preventive treatment of risk factors, or towards late interventional strategies. Despite this therapeutic arsenal, the incidence of clinical events remains dramatically high, dependent, at least in part, on the increasing frequency of type 2 diabetes and ageing. But some medical treatments, focusing only on prevention of the metabolic risk, have failed to reduce cardiovascular mortality, thus illustrating that our understanding of the pathophysiology of human atherothrombosis leading to clinical events remain incomplete. New paradigms are now emerging which may give rise to novel experimental strategies to improve therapeutic efficacy and prediction of disease progression. Recent studies strengthen the concept that the intraplaque neovascularization and bleeding (Figure 1, upper panel) are events that could play a major role in plaque progression and leucocyte infiltration, and may also serve as a measure of risk for the development of future events. The recent advances in our understanding of IntraPlaque Hemorrhage as a critical event in triggering acute clinical events have important implications for clinical research and possibly future clinical practice. PMID:21398643

Michel, Jean-Baptiste; Virmani, Renu; Arbustini, Eloïsa; Pasterkamp, Gerard



Evaluating practice patterns for managing moderate to severe plaque psoriasis  

PubMed Central

Abstract Objective To describe practice patterns for care of Canadian patients with moderate to severe plaque psoriasis. Design Online survey of a consumer panel. Setting Participants were drawn from a population-wide Canadian consumer database. Participants To be eligible to participate, respondents had to have been diagnosed with plaque psoriasis within the past 5 years, and to have had body surface area involvement of 3% or greater in the past 5 years, or to have psoriasis on a sensitive area of the body (hands, feet, scalp, face, or genitals), or to be currently receiving treatment with systemic agents or phototherapy for psoriasis. Main outcome measures Proportion of respondents with psoriasis managed by FPs and other specialists, psoriasis therapies, comorbidities, and patient satisfaction. Results Invitations were sent to 3845 panelists with self-reported psoriasis, of which 514 qualified to complete the survey. Family physicians were reported to be the primary providers for diagnosis and ongoing care of psoriasis in all provinces except Quebec. Overall physician care was reported to be satisfactory by 62% of respondents. Most respondents receiving over-the-counter therapies (55%) or prescribed topical therapies (61%) reported that their psoriasis was managed by FPs. Respondents receiving prescription oral or injectable medications or phototherapy were mainly managed by dermatologists (42%, 74%, and 71% of respondents, respectively). Ongoing management of respondents with body surface area involvement of 10% or greater was mainly split between dermatologists (47%) and FPs (45%), compared with rheumatologists (4%) or other health care professionals (4%). Of those respondents receiving medications for concomitant health conditions, treatment for high blood pressure was most common (92%), followed by treatment for heart disease (75%) and elevated cholesterol and lipid levels (68%). Conclusion Patient-reported practice patterns for the diagnosis and management of moderate to severe psoriasis vary among provinces and in primary and secondary care settings.

Poulin, Yves; Wasel, Norman; Chan, Daphne; Bernstein, Geula; Andrew, Robin; Fraquelli, Elisa; Papp, Kim



CycloOxygenase2 –765G > C Promoter Variants Are Associated with Lower Carotid Plaque Echogenicity in Japanese  

Microsoft Academic Search

Background and Purpose: Recent studies revealed that inflammation contributes to plaque instability. Cyclo-oxygenase (COX)-2 is one of the key enzymes in plaque inflammation. We examined the relation between a polymorphism in the COX-2 gene and carotid plaque echogenicity in patients with high risk of cerebrovascular disease to evaluate the involvement of COX-2 in plaque instability. Methods: The study comprised 469

Shigetaka Furukado; Manabu Sakaguchi; Hiroshi Yamagami; Yoshiki Yagita; Taku Hoshi; Yuko Abe; Hidetaka Hougaku; Masatsugu Hori; Saburo Sakoda; Kazuo Kitagawa



Staining of cerebral amyloid plaque glycoproteins in patients with Alzheimer's disease with the microglia-specific lectin from mistletoe  

Microsoft Academic Search

Glycoconjugates in the amyloid plaques in the cerebral cortex of patients with Alzheimer's disease were stained with a lectin from mistletoe (ML-I). This lectin selectively stains microglial cells which can be found in the centre of many plaques. Since the terminal carbohydrate moieties of some but not all of the plaques, which mainly consist of A4 protein, are identical to

U. Schumacher; H. Kretzschmar; U. Pfüller



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

PubMed Central

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



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

Microsoft Academic Search

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

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



Basic Biological Sciences The Effects of Fatty Acids and Their Monoesters on the Metabolic Activity of Dental Plaque  

Microsoft Academic Search

We examined the effects of the saturated series of fatty acids and their esters on plaque bacterial metabolism. Fatty acids with a chain length of 8-15 carbons inhibited Streptococcus mutans and dental plaque in vitro. The glycerol monoesters with a fatty acid chain of 10-14 carbons were inhibitory to a similar extent. The glycolipid (sucrose monolaurate) reduced plaque bacterial glycolysis

M. L. Hayes



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

Microsoft Academic Search

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

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



Lives of Stone, Lives of People: Re-Viewing the Engraved Plaques of Late Neolithic and Copper Age Iberia  

Microsoft Academic Search

For over a century prehistorians have approached the engraved stone plaques of the Iberian late Neolithic and Copper Age (3000-2500 BC) from a monolithic and idealist perspective, viewing the plaques as representations of the Mother Goddess. Most have not addressed the plaques’ variability, their method of manufacture, the organization of their production, or their biographies. This article presents new interpretations

Katina Lillios



Reduced Apoptosis and Plaque Necrosis in Advanced Atherosclerotic Lesions of Apoe-/- and Ldlr-/- Mice Lacking CHOP  

PubMed Central

SUMMARY Endoplasmic reticulum (ER) stress is a hallmark of advanced atherosclerosis, but its causative role in plaque progression is unknown. In-vitro studies have implicated the ER stress effector CHOP in macrophage apoptosis, a process involved in plaque necrosis in advanced atheromata. To test the effect of CHOP deficiency in vivo, aortic root lesions of fat-fed Chop+/+;Apoe?/? and Chop?/?;Apoe?/? mice were analyzed for size and morphology. Despite similar plasma lipoproteins, lesion area was 35% smaller in Chop?/?;Apoe?/? mice. Most importantly, plaque necrosis was reduced by ~50% and lesional apoptosis by 35% in the CHOP-deficient mice. Similar results were found in fat-fed Chop?/?;Ldlr?/? vs. Chop+/+;Ldlr?/? mice. Thus, CHOP promotes plaque growth, apoptosis, and plaque necrosis in fat-fed Apoe?/? and Ldlr?/? mice. These data provide direct evidence for a causal link between the ER stress effector CHOP and plaque necrosis and suggest that interventions weakening this arm of the UPR may lessen plaque progression.

Thorp, Edward; Li, Gang; Seimon, Tracie A.; Kuriakose, George; Ron, David; Tabas, Ira



Detection of noncalcified and mixed plaque by multirow detector computed tomography.  


New tomographic cardiovascular imaging tests, such as intravascular ultrasonography and coronary computed tomography angiography, can be used to assess atherosclerotic plaques for the characterization and early staging of coronary artery disease (CAD). Although intravascular ultrasonography provides high-resolution images that are capable of revealing early preclinical CAD, it is a highly invasive technique used clinically only in conjunction with coronary interventions. Multidetector computed tomography angiography, which is noninvasive and corresponds well with plaque histology, shows promise as a diagnostic method for CAD and can provide general evaluation of noncalcified and mixed plaque composition. The current generation of 64-slice computed tomography scanners have high accuracy for detection of lesions obstructing more than 50% of the lumen, with sensitivity, specificity, and positive and negative predictive values all over 90% in patients without known CAD. They may have an important role in characterizing high-risk noncalcified and mixed plaques. Review of the currently available literature suggests that tissue density measured by multidetector computed tomography can be used to accurately characterize coronary atherosclerotic plaque composition. With further advances in tomographic angiography, the goal will be to detect plaques earlier in the development of CAD and to characterize the plaques most likely to generate a clinical event. PMID:19105767

Foster, Gary; Shah, Harsh; Sarraf, Guilda; Ahmadi, Naser; Budoff, Matthew



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

NASA Astrophysics Data System (ADS)

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

Lander, J. J.



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


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



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.

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



MRI-based biomechanical imaging: initial study on early plaque progression and vessel remodeling.  


The goal of the study is to develop a noninvasive magnetic resonance imaging (MRI)-based biomechanical imaging technique to address biomechanical pathways of atherosclerotic progression and regression in vivo using a 3D fluid-structure interaction (FSI) model. Initial in vivo study was carried out in an early plaque model in pigs that underwent balloon-overstretch injury to the left carotid arteries. Consecutive MRI scans were performed while the pigs were maintained on high cholesterol (progression) or normal chow (regression), with an injection of a plaque-targeted contrast agent, Gadofluorine M. At the end of study, the specimens of carotid arterial segments were dissected and underwent dedicated mechanical testing to determine their material properties. 3D FSI computational model was applied to calculate structure stress and strain distribution. The plaque structure resembles early plaque with thickened intima. Lower maximal flow shear stress correlates with the growth of plaque volume during progression, but not during regression. In contrast, maximal principle structure stress/stain (stress-P1 and strain-P1) were shown to correlate strongly with the change in the plaque dimension during regression, but moderately during progression. This MRI-based biomechanical imaging method may allow for noninvasive dynamic assessment of local hemodynamic forces on the development of atherosclerotic plaques in vivo. PMID:19559552

Zheng, Jie; Abendschein, Dana R; Okamoto, Ruth J; Yang, Deshan; McCommis, Kyle S; Misselwitz, Bernd; Gropler, Robert J; Tang, Dalin



Oral hygiene indirect instruction and periodic reinforcements: effects on index plaque in schoolchildren.  


The aim of this study was to evaluate the effectiveness of the indirect instruction and the influence of the periodic reinforcement on the plaque index in schoolchildren. Forty schoolchildren aged from 7 to 9 years old were selected from a public school. After determining the initial O'Leary Plaque Index all schoolchildren were submitted to a program for oral hygiene through indirect instruction -"The Smiling Robot". The schoolchildren were divided into 2 groups: with and without motivation reinforcement. The index plaque exam was performed in both groups after 30, 60 and 90 days of the educational program. Comparing the groups, the plaque index decreasing could be observed in the group with reinforcement with statistically significant difference. For the group with reinforcement, statistically significant difference among the evaluations was found. For the group without reinforcement, significant decrease in the plaque index was found after 30 days when compared to the first, third and fourth evaluations. The indirect instruction with "The Smiling Robot "promoted a positive initial impact on the decrease of plaque index in the schoolchildren. The periodic reinforcements showed more suitable results and significant reduction of the plaque index in the course of the evaluations. PMID:19953806

Rodrigues, Jonas Almeida; dos Santos, Patrícia Aleixo; Baseggio, Wagner; Corona, Silmara Aparecida Milori; Palma-Dibb, Regina Guenka; Garcia, Patrícia Petromilli Nordi Sasso



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


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

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



Plaque erosion is a major substrate for coronary thrombosis in acute myocardial infarction  

PubMed Central

OBJECTIVE—To evaluate the prevalence of plaque erosion as a substrate for coronary thrombosis.?DESIGN—Pathological study in patients with acute myocardial infarction not treated with thrombolysis or coronary interventional procedures.?PATIENTS—298 consecutive patients (189 men, mean (SD) age 66 (11) years; 109 women, 74 (8) years) dying in hospital between 1984 and 1996 from acute myocardial infarction, diagnosed by ECG changes and rise in cardiac enzymes.?MAIN OUTCOME MEASURES—Histopathological determination of plaque erosion as substrate for acute thrombosis; location and histological type of coronary thrombosis; acute and healed myocardial infarcts; ventricular rupture.?RESULTS—Acute coronary thrombi were found in 291 hearts (98%); in 74 cases (25%; 40/107 women (37.4%) and 34/184 men (18.5%); p = 0.0004), the plaque substrate for thrombosis was erosion. Healed infarcts were found in 37.5% of men v 22% of women (p = 0.01). Heart rupture was more common in women than in men (22% v 10.5%, p = 0.01). The distribution of infarcts, thrombus location, heart rupture, and healed infarcts was similar in cases of plaque rupture and plaque erosion.?CONCLUSIONS—Plaque erosion is an important substrate for coronary thrombosis in patients dying of acute myocardial infarction. Its prevalence is significantly higher in women than in men.???Keywords: plaque erosion; rupture; acute myocardial infarction

Arbustini, E; Dal, B; Morbini, P; Burke, A; Bocciarelli, M; Specchia, G; Virmani, R



MRI-based biomechanical imaging: initial study on early plaque progression and vessel remodeling  

PubMed Central

The goal of the study is to develop a noninvasive magnetic resonance imaging (MRI)-based biomechanical imaging technique to address biomechanical pathways of atherosclerotic progression and regression in vivo using a 3D fluid-structure interaction (FSI) model. Initial in vivo study was carried out in an early plaque model in pigs that underwent balloon-overstretch injury to the left carotid arteries. Consecutive MRI scans were performed while the pigs were maintained on high cholesterol (progression) or normal chow (regression), with an injection of a plaque-targeted contrast agent, Gadofluorine M. At the end of study, the specimens of carotid arterial segments were dissected and underwent dedicated mechanical testing to determine their material properties. 3D FSI computational model was applied to calculate structure stress and strain distribution. The plaque structure resembles early plaque with thickened intima. Lower maximal flow shear stress correlates with the growth of plaque volume during progression, but not during regression. In contrast, maximal principle structure stress/stain (stress-P1 and strain-P1) were shown to correlate strongly with the change in the plaque dimension during regression, but moderately during progression. This MRI-based biomechanical imaging method may allow for noninvasive dynamic assessment of local hemodynamic forces on the development of atherosclerotic plaques in vivo.

Zheng, Jie; Abendschein, Dana R.; Okamoto, Ruth J.; Yang, Deshan; McCommis, Kyle S.; Misselwitz, Bernd; Gropler, Robert J.; Tang, Dalin



Mechanical, biological and structural characterization of in vitro ruptured human carotid plaque tissue.  


Recent experimental studies performed on human carotid plaques have focused on mechanical characterization for the purpose of developing material models for finite-element analysis without quantifying the tissue composition or relating mechanical behaviour to preoperative classification. This study characterizes the mechanical and biological properties of 25 human carotid plaques and also investigates the common features that lead to plaque rupture during mechanical testing by performing circumferential uniaxial tests, Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) on each specimen to relate plaque composition to mechanical behaviour. Mechanical results revealed large variations between plaque specimen behaviour with no correlation to preoperative ultrasound prediction. However, FTIR classification demonstrated a statistically significant relationship between stress and stretch values at rupture and the level of calcification (P=0.002 and P=0.009). Energy-dispersive X-ray spectroscopy was carried out to confirm that the calcium levels observed using FTIR analysis were accurate. This work demonstrates the potential of FTIR as an alternative method to ultrasound forpredicting plaque mechanical behaviour. SEM imaging at the rupture sites of each specimen highlighted voids created by the nodes of calcifications in the tissue structure which could lead to increased vulnerability of the plaque. PMID:23871944

Mulvihill, J J; Cunnane, E M; McHugh, S M; Kavanagh, E G; Walsh, S R; Walsh, M T



The precursors of coronary atherosclerotic plaques in subjects up to 40 years old.  


The onset of coronary atherosclerotic plaques was investigated in 400 selected cases aged 1--40 years. During childhood the atherosclerotic plaques developed on their own, in preexisting branch pads or cushions. During adolescence the atherosclerotic plaques developed on their own, in both branch pads or cushions and thickened intimas. In young and mature adults the thickened intima became the main site for plaque histogenesis, whereas the role of branch pads or cushions decreased significantly. In mature adults incorporated microthrombi were accidentally involved in plaque development. In both branch pads or cushions and thickened intimas the atherosclerotic plaques developed through several stages including: histolysis, followed by nodular proliferation of smooth muscle cells (prevalent during childhood), insudation (prevalent during adolescence), accumulation of lipid-filled and foam cells (prevalent during early adulthood) and necrosis (prevalent in mature adults). Likewise the coronary fatty streaks developed on their own, through several stages, from early to advanced lesions. We were unable to reveal the conversion of fatty streaks into atherosclerotic plaques the two types of lesions occurring as unrelated pathological processes. PMID:7426086

Velican, C; Velican, D



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



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


The histological picture of psoriasis has been studied extensively. Several authors have investigated the differences between the centre and the margin of spreading plaques, because the margin is of great pathogenic interest as lesions enlarge by centrifugal expansion. However, little is known about the differences between the centre and the margin of stable plaques. In the present study we investigated quantitatively the differences between the centre and margin of stable psoriatic plaques with respect to differentiation, inflammation and proliferation. To quantify these parameters, we used flow cytometry. From nine patients with nonspreading, stable psoriasis, we obtained punch biopsies from the centre and from the lesional margin of a plaque, and performed a flow cytometric assessment, using the markers keratin 10 for differentiation, vimentin for inflammation, and TO-PRO-3 iodide for proliferation. We found that the quantitative parameters showed a large interindividual variability, and that there was no significant difference in the quantitative parameters for inflammation and proliferation between the centre and margin of stable plaques. However, the percentage of differentiated cells was significantly higher in the margin than in the centre. We conclude that there is a great heterogeneity within stable psoriatic plaques with respect to differentiation, inflammation and proliferation, but further quantitative studies are needed to substantiate the pathogenic relevance of the significant difference in keratinization between the centre and the margin of stable psoriatic plaques. PMID:10195395

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


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.

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



Hemolytic Plaque Formation by Leukocytes in Vitro CONTROL BY VASOACTIVE HORMONES  

PubMed Central

Histamine, beta-adrenergic amines, and prostaglandins inhibited hemolytic plaque formation by splenic leukocytes from immunized mice. The same agents had previously been shown to prevent both the IgE-mediated release of histamine from human basophils and the immunologically specific cytolytic activity of murine lymphocytes, through stimulation of the production of cyclic AMP in leukocytes. We therefore tested the hypothesis that cyclic AMP might mediate an inhibitory effect of these drugs by comparing the ability of these agents to inhibit plaque formation with their effects on cyclic AMP accumulation in leukocytes. In splenic cells from three mouse strains, the dose-dependent effects of these agents of cyclic AMP correlated with their inhibition of plaque formation. Beta- but not alpha-adrenergic agonists were effective in both systems, and the effects of isoproterenol were inhibited by propranolol. Histamine was approximately equipotent with isoproterenol in both systems. Two prostaglandins (E1 and E2) were effective in both systems, but prostaglandin F2? was not. Dibutyryl cyclic AMP, a lipid-soluble analog of the endogenous nucleotide, inhibited plaque formation by cells of all three strains. Theophylline, an inhibitor of cyclic AMP degradation, inhibited plaque formation slightly, but potentiated the effects of histamine, isoproterenol, and the prostaglandins on both cyclic AMP accumulation and plaque formation. Finally, cholera enterotoxin, a potent activator of adenyl cyclase, produced a delayed inhibition of plaque formation and a parallel increase in leukocyte cyclic AMP content; both effects of the toxin were blocked by canine antitoxin. These results suggest that leukocyte cyclic AMP may act as a “second messenger” to suppress plaque formation in vitro. The inhibitory effects of hormones and cyclic AMP on plaque formation are strikingly similar to their effects on in vitro models of immediate and cell-mediated hypersensitivity. The physiologic significance of these findings is not yet known.

Melmon, Kenneth L.; Bourne, Henry R.; Weinstein, Yacob; Shearer, G. M.; Kram, Jerrold; Bauminger, Sara



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


Several studies have suggested that evolving mechanical stresses and strains drive atherosclerotic plaque development and vulnerability. Especially, stress distribution in the plaque fibrous capsule is an important determinant for the risk of vulnerable plaque rupture. Knowledge of the stiffness of atherosclerotic plaque components is therefore of critical importance. In this work, force mapping experiments using atomic force microscopy (AFM) were conducted in apolipoprotein E-deficient (ApoE(-/-)) mouse, which represents the most widely used experimental model for studying mechanisms underlying the development of atherosclerotic lesions. To obtain the elastic material properties of fibrous caps and lipidic cores of atherosclerotic plaques, serial cross-sections of aortic arch lesions were probed at different sites. Atherosclerotic plaque sub-structures were subdivided into cellular fibrotic, hypocellular fibrotic and lipidic rich areas according to histological staining. Hertz's contact mechanics were used to determine elasticity (Young's) moduli that were related to the underlying histological plaque structure. Cellular fibrotic regions exhibit a mean Young modulus of 10.4±5.7kPa. Hypocellular fibrous caps were almost six-times stiffer, with average modulus value of 59.4±47.4kPa, locally rising up to ?250kPa. Lipid rich areas exhibit a rather large range of Young's moduli, with average value of 5.5±3.5kPa. Such precise quantification of plaque stiffness heterogeneity will allow investigators to have prospectively a better monitoring of atherosclerotic disease evolution, including arterial wall remodeling and plaque rupture, in response to mechanical constraints imposed by vascular shear stress and blood pressure. PMID:21296163

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



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

PubMed Central

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

Lee, Jung-Eun



Methicillin-resistant Staphylococcus aureus phage plaque size enhancement using sublethal concentrations of antibiotics.  


Phage therapy presents an alternative approach against the emerging methicillin-resistant Staphylococcus aureus (MRSA) threat. Some of the problems encountered during isolation of MRSA phages include the high prevalence of enteric phages in natural sources, nonspecific absorption of viable phage, and the formation of pinpoint or tiny plaques. The phage isolated in this study, MR-5, also formed tiny plaques against its host S. aureus ATCC 43300 (MRSA), making its detection and enumeration difficult. An improved method of increasing the plaque size of MRSA phage by incorporating sublethal concentrations of three different classes of antibiotics (inhibitors of protein synthesis) in the classical double-layer agar (DLA) method was investigated. The ?-lactam and quinolone antibiotics commonly employed in earlier studies for increasing the plaque size did not show any significant effect on the plaque size of isolated MR-5 phage. Linezolid (oxazolidinone class), tetracycline, and ketolide antibiotics brought significant enhancements (3 times the original size) in the plaque size of MR-5 phage. Prior treatment with these antibiotics resulted in significant reductions in the time of adsorption and the latent period of MR-5 phage. To rule out whether the action of linezolid (which brought the maximum increase in plaque size) was specific for a single phage only, its effect on the plaque size of seven other S. aureus-specific phages was also assessed. Significant enhancements in the plaque size of these phages were observed. These results indicate that this modification can therefore safely be incorporated in the traditional DLA overlay method to search for new MRSA-virulent phages. PMID:23001655

Kaur, Sandeep; Harjai, Kusum; Chhibber, Sanjay



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)



Methicillin-Resistant Staphylococcus aureus Phage Plaque Size Enhancement Using Sublethal Concentrations of Antibiotics  

PubMed Central

Phage therapy presents an alternative approach against the emerging methicillin-resistant Staphylococcus aureus (MRSA) threat. Some of the problems encountered during isolation of MRSA phages include the high prevalence of enteric phages in natural sources, nonspecific absorption of viable phage, and the formation of pinpoint or tiny plaques. The phage isolated in this study, MR-5, also formed tiny plaques against its host S. aureus ATCC 43300 (MRSA), making its detection and enumeration difficult. An improved method of increasing the plaque size of MRSA phage by incorporating sublethal concentrations of three different classes of antibiotics (inhibitors of protein synthesis) in the classical double-layer agar (DLA) method was investigated. The ?-lactam and quinolone antibiotics commonly employed in earlier studies for increasing the plaque size did not show any significant effect on the plaque size of isolated MR-5 phage. Linezolid (oxazolidinone class), tetracycline, and ketolide antibiotics brought significant enhancements (3 times the original size) in the plaque size of MR-5 phage. Prior treatment with these antibiotics resulted in significant reductions in the time of adsorption and the latent period of MR-5 phage. To rule out whether the action of linezolid (which brought the maximum increase in plaque size) was specific for a single phage only, its effect on the plaque size of seven other S. aureus-specific phages was also assessed. Significant enhancements in the plaque size of these phages were observed. These results indicate that this modification can therefore safely be incorporated in the traditional DLA overlay method to search for new MRSA-virulent phages.

Kaur, Sandeep; Harjai, Kusum



Mechanisms of progression in native coronary artery disease: role of healed plaque disruption  

PubMed Central

OBJECTIVE—To determine the role of healed plaque disruption in the generation of chronic high grade coronary stenosis.?METHODS—Coronary arteries obtained at necropsy were perfuse fixed with formal saline for 24 hours at 100 mg Hg. The percentage lumen diameter stenosis was measured in each 3 mm segment containing a plaque, using the lumen size at the nearest histologically normal segment as the reference point. Each segment was prepared for histological examination and stained with Sirius red and immunohistochemistry for smooth muscle actin. Healed disruption was considered to be present when under polarised light there was a break in the yellow-white dense collagen of the cap filled in by more loosely arranged green collagen. Increased smooth muscle density in the green staining areas was required. Each section was read independently by two observers; any segment with discordant views was considered negative.?MATERIAL—31 men aged 51-69 dying suddenly of ischaemic heart disease. 39 coronary arteries were studied containing 256 separate plaques, after excluding coronary arteries with old total occlusions, an acute culprit thrombotic lesion, diffuse disease without normal arterial segments, and arteries related to old myocardial scars.?RESULTS—16 of 99 plaques causing < 20% diameter stenosis had prior disruption. In the 21-50% stenosis range 16 of 86 plaques showed healed disruption. Stenosis ? 51% by diameter was present in 71 plaques, 52 of which showed a healed disruption pattern. The difference between stenosis < 50% and stenosis ? 51% was significant by the ?2 test (p < 0.001).?CONCLUSIONS—Subclinical episodes of plaque disruption followed by healing are a stimulus to plaque growth that occurs suddenly and is a major factor in causing chronic high grade coronary stenosis. This mechanism would explain the phasic rather than linear progression of coronary disease observed in angiograms carried out annually in patients with chronic ischaemic heart disease.???Keywords: atherosclerosis; stenosis; plaque disruption

Mann, J; Davies, M



Effect of a new pre-brushing rinse on dental plaque removal.  


Non-prescription prebrushing rinses to facilitate dental plaque removal have been advertised in recent years. The purpose of the present study was to determine the plaque removal effectiveness of Plax (Colgate) prebrushing rinse by comparing it to a placebo solution. 19 dental students volunteered for this double blind study which consisted of 2 experimental periods. The following procedure was followed: 3 weeks after scaling and polishing, the participants abstained from oral hygiene for 3 days to allow dental plaque to accumulate. After plaque disclosing, the 4 mandibular incisors were photographed using a strictly defined technique, as described by Quirynen et al. Then the volunteers mouthrinsed for 30 s with 15 ml of a solution provided to them. Neither the volunteers nor the examiners knew which solution (test or control) was used. After mouthrinsing, the participants were allowed to brush their teeth and the remaining plaque was photographed again. During the 2nd experimental period, the same procedure was followed, and the 2nd solution was used for mouthrinsing. The effectiveness of the solutions was evaluated by comparing the proportion of dental plaque removed during the 2 experimental periods. The area of dental plaque was measured by an electronic high-precision device (planimeter). The proportion of plaque removed after rinsing with Plax was 0.40 +/- 0.23 and after rising with placebo 0.42 +/- 0.24, of the tooth surface (p = 0.962). Analysis of data by means of paired t-test between the 2 experimental periods revealed no beneficial effect regarding plaque removal when Plax was used. PMID:7852615

Vouros, J; Sakellari, D; Konstantinidis, A



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.

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



Effects of crude extracts of various plants on infectious bovine rhinotracheitis virus-plaque production.  


Extracts of 28 plants were tested without demonstable antiviral activity in an agar-overlay plaque-reduction antiviral assay system, using infectious bovine rhinotracheitis virus and bovine endocardial cell cultures. Ethanolic extract of Narcissus tazetta L bulb elicited antiviral activity by inhibition of viral plaque formation. Antiviral activity was demonstrated against infectious bovine rhinotracheitis and equine rhinopneumonitis viruses. Narcissus tazetta L bulb did not directly inactivate the virus extracellularly. The extract exhibited only limited toxicity to rapidly multiplying bovine endocardial cells at plaque-inhibitory levels and was not cytoxic to preformed confluent cell monolayers. Narcissus extract did not induce the formation of drug-resistant viral strains. PMID:176907

Kelling, C L; Schipper, I A; Schermeister, L J; Vacik, J P



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))



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

PubMed Central

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

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



Measurement of intima-media thickness vs. carotid plaque: uses in patient care, genetic research and evaluation of new therapies.  


Intima-media thickness (IMT) has been measured for over 20 years, and is widely regarded as a surrogate for atherosclerosis. However, in the carotid arteries atherosclerosis is focal, manifesting as plaques. IMT is often measured deliberately where no plaque exists, or multiple measurements may be averaged, including only one or two that intersect plaque. IMT and plaque are biologically and genetically distinct, so they can be expected to respond differentially to therapies for atherosclerosis. Furthermore, because plaques grow along the carotid arteries 2.4 times faster than they thicken, progression or regression of total plaque area is more sensitive to effects of therapy than IMT. Because plaques also grow and regress circumferentially, three-dimensional (3-D) plaque volume is two orders of magnitude more sensitive to effects of therapy than is IMT. While 3-D ultrasound requires special equipment, total plaque area can be measured using the same equipment as IMT. Because plaque and IMT are biologically and genetically distinct entities, representing different phenotypes of atherosclerosis, both should be measured in any situation where IMT is measured, with the exception of studies in children too young for the occurrence of plaque. IMT should not be called 'atherosclerosis': the phenotype being assessed should be specified. PMID:18706019

Spence, J David



Developing a novel rabbit model of atherosclerotic plaque rupture and thrombosis by cold-induced endothelial injury  

PubMed Central

Background It is widely believed that atherosclerotic plaque rupture and subsequent thrombosis leads to acute coronary events and stroke. However, study of the mechanism and treatment of human plaque rupture is hampered by lack of a suitable animal model. Our aim was to develop a novel animal model of atherosclerotic plaque rupture to facilitate the study of human plaque disruption and thrombosis. Methods 28 healthy male New Zealand white rabbits were randomly divided into two groups: rabbits in group A (n = 12) were only fed a high-fat diet for eight weeks; rabbits in group B (n = 16) underwent cold-induced endothelial injury with liquid nitrogen, then were given a high-fat diet for eight weeks. After completion of the preparatory regimen, triggering of plaque rupture was attempted by local injection of liquid nitrogen in both groups. Results All rabbits in group B had disrupted plaques or rupture-driven occlusive thrombus formation, but none in group A showed any effects. More importantly, the cold-induced plaques in our model were reminiscent of human atherosclerotic plaques in terms of architecture, cellular composition, growth characteristics, and patterns of lipid accumulation. Conclusion We successfully developed a novel rabbit model of atherosclerotic plaque rupture and thrombosis, which is simple, fast, inexpensive, and reproducible, and has a low mortality and a high yield of triggering. This model will allow us to better understand the mechanism of human plaque rupture and also to develop plaque-stabilizing therapies.

Fang, Shun-Miao; Zhang, Qing-Hua; Jiang, Zhi-Xin



Is chronic plaque psoriasis triggered by microbiota in the skin?  


There is a known association between psoriasis and Crohn disease (CD). Patients with CD are five times more likely to develop psoriasis, and, conversely, patients with psoriasis are more likely to develop CD. Many gastroenterologists now accept that CD results from a breakdown of immune tolerance to the microbiota of the intestine in genetically susceptible individuals. The microbiota of the skin have recently been investigated in psoriasis. Firmicutes was the most common phylum, and Streptococcus the most common genus identified. Beta-haemolytic streptococci have been implicated in both guttate and chronic plaque psoriasis. Furthermore, the innate immune system has been shown to be activated in psoriasis, and many of the genes associated with the disease are concerned with the signalling pathways of the innate immune system, notably interleukin-23 and nuclear factor ?B. Patients with psoriasis also have an increased incidence of periodontitis, a disease thought to be due to an abnormal response to normal oral commensals. Based on the similarities between CD and psoriasis, we propose that psoriasis is due to a breakdown of immune tolerance to the microbiota of the skin. In support of this hypothesis we provide evidence for microbiota in the skin, activation of the innate immune system, and genetic abnormalities involving the innate immune system. PMID:23521130

Fry, L; Baker, B S; Powles, A V; Fahlen, A; Engstrand, L



IVUS-based histology of atherosclerotic plaques: improving longitudinal resolution  

NASA Astrophysics Data System (ADS)

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

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



Biofilms, a new approach to the microbiology of dental plaque.  


Dental plaque has the properties of a biofilm, similar to other biofilms found in the body and the environment. Modern molecular biological techniques have identified about 1000 different bacterial species in the dental biofilm, twice as many as can be cultured. Oral biofilms are very heterogeneous in structure. Dense mushroom-like structures originate from the enamel surface, interspersed with bacteria-free channels used as diffusion pathways. The channels are probably filled with an extracellular polysaccharide (EPS) matrix produced by the bacteria. Bacteria in biofilms communicate through signaling molecules, and use this "quorum-sensing" system to optimize their virulence factors and survival. Bacteria in a biofilm have a physiology different from that of planktonic cells. They generally live under nutrient limitation and often in a dormant state. Such "sleepy" bacteria respond differently to antibiotics and antimicrobials, because these agents were generally selected in experiments with metabolically active bacteria. This is one of the explanations as to why antibiotics and antimicrobials are not as successful in the clinic as could be expected from laboratory studies. In addition, it has been found that many therapeutic agents bind to the biofilm EPS matrix before they even reach the bacteria, and are thereby inactivated. Taken together, these fundings highlight why the study of bacteria in the oral cavity is now taken on by studying the biofilms rather than individual species. PMID:16998612

ten Cate, Jacob M



Bilateral scaly plaques in axillae: pityriasis rosea of Vidal.  


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

Zawar, Vijay


Symptomatic vs. asymptomatic plaque classification in carotid ultrasound.  


Quantitative characterization of carotid atherosclerosis and classification into symptomatic or asymptomatic type is crucial in both diagnosis and treatment planning. This paper describes a computer-aided diagnosis (CAD) system which analyzes ultrasound images and classifies them into symptomatic and asymptomatic based on the textural features. The proposed CAD system consists of three modules. The first module is preprocessing, which conditions the images for the subsequent feature extraction. The feature extraction stage uses image texture analysis to calculate Standard deviation, Entropy, Symmetry, and Run Percentage. Finally, classification is performed using AdaBoost and Support Vector Machine for automated decision making. For Adaboost, we compared the performance of five distinct configurations (Least Squares, Maximum- Likelihood, Normal Density Discriminant Function, Pocket, and Stumps) of this algorithm. For Support Vector Machine, we compared the performance using five different configurations (linear kernel, polynomial kernel configurations of different orders and radial basis function kernels). SVM with radial basis function kernel for support vector machine presented the best classification result: classification accuracy of 82.4%, sensitivity of 82.9%, and specificity of 82.1%. We feel that texture features coupled with the Support Vector Machine classifier can be used to identify the plaque tissue type. An Integrated Index, called symptomatic asymptomatic carotid index (SACI), is proposed using texture features to discriminate symptomatic and asymptomatic carotid ultrasound images using just one index or number. We hope this SACI can be used as an adjunct tool by the vascular surgeons for daily screening. PMID:21243411

Acharya, Rajendra U; Faust, Oliver; Alvin, A P C; Sree, S Vinitha; Molinari, Filippo; Saba, Luca; Nicolaides, Andrew; Suri, Jasjit S



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.

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.



Caries Inducing Streptococci and Polysaccharide Forming Ability of Dental Plaque as Indicators of Caries Susceptibility.  

National Technical Information Service (NTIS)

Evaluation of the null hypothesis that after having taken into account a number of epidemiological variables there are no differences in the relative frequencies of various 'caries inducing' micro-organisms and the sucrase activity of plaque in children a...

W. F. Liljemark J. I. Swenson



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.



Decreased senile plaque density in Alzheimer neocortex adjacent to an omental transposition.  


Post-mortem studies of the brain of an Alzheimer patient indicate fewer senile plaques in the crests of cortical gyri underneath an omental transposition than in neighboring cortical areas. PMID:8875444

Relkin, N R; Edgar, M A; Gouras, G K; Gandy, S E; Goldsmith, H S



Dietary supplementation with resveratrol reduces plaque pathology in a transgenic model of Alzheimer's Disease  

PubMed Central

Resveratrol, a polyphenol found in red wine, peanuts, soy beans, and pomegranates, possesses a wide range of biological effects. Since resveratrol’s properties seem ideal for treating neurodegenerative diseases, its ability to diminish amyloid plaques was tested. Mice were fed clinically feasible dosages of resveratrol for forty-five days. Neither resveratrol nor its conjugated metabolites were detectable in brain. Nevertheless, resveratrol diminished plaque formation in a region specific manner. The largest reductions in the percent area occupied by plaques were observed in medial cortex (?48%), striatum (?89%) and hypothalamus (?90%). The changes occurred without detectable activation of SIRT-1 or alterations in APP processing. However, brain glutathione declined 21% and brain cysteine increased 54%. The increased cysteine and decreased glutathione may be linked to the diminished plaque formation. This study supports the concept that onset of neurodegenerative disease may be delayed or mitigated with use of dietary chemo-preventive agents that protect against ?-amyloid induced neuronal damage.

Karuppagounder, Saravanan S.; Pinto, John T.; Xu, Hui; Chen, Lian H.; Beal, M. Flint; Gibson, Gary E.



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


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



Influence of Modified Diets Upon the Quality and Quantity of Human Dental Plaque.  

National Technical Information Service (NTIS)

The effects of dietary sucrose, as a component of a well characterized diet, on plaque quantity, its microbial and biochemical composition were determined under carefully supervised conditions in young healthy males and females. The study was composed of ...



Iron plaque formation and morphoanatomy of roots from species of restinga subjected to excess iron.  


The restingas, a sandy coastal plain ecosystem of Brazil, have received an additional amount of iron due to the activity of mining industries. The present study aims to characterize morphoanatomically and histochemically the iron plaque formation on roots of Ipomoea pes-caprae L. and Canavalia rosea DC, cultivated in hydroponic solution with and without excess iron. The iron plaque formation as well as changes in the external morphology of the lateral roots of both species were observed after the subjection to excess iron. Changes in the nutrient uptake, and in the organization and form of the pericycle and cortex cells were observed for both species. Scanning electron microscopy showed evident iron plaques on the whole surface of the root. The iron was histolocalized in all root tissues of both species. The species of restinga studied here formed iron plaque in their roots when exposed to excess of this element, which may compromise their development in environments polluted by particulated iron. PMID:22169228

Siqueira-Silva, Advanio Inácio; da Silva, Luzimar Campos; Azevedo, Aristéa Alves; Oliva, Marco Antonio



Effects of Sanguinaria Extract on Plaque Retention and Gingival Health in Active Orthodontic Patients.  

National Technical Information Service (NTIS)

Controlling plaque accumulation in orthodontic patients is of primary importance to all orthodontists. A new antiplane chemotherapeutic agent which contains sanguimaria extract was recently been introduced and proven to be effective in periodontal patient...

R. A. Miller




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

DETAIL OF ?BIVOUAC OF THE DEAD? PLAQUES, SOUTH OF CHAPEL/ADMINISTRATION BUILDING. VIEW TO NORTHEAST. - Los Angeles National Cemetery, 950 South Sepulveda Boulevard, Los Angeles, Los Angeles County, CA


Clinical Evaluation of a Method for Plaque Removal Using a Single-Tufted Toothbrush.  

National Technical Information Service (NTIS)

A single-tufted toothbrush attachment to an electric toothbrush holder was recently made available as a method for increasing the effectiveness of interdental cleansing. The purpose of this study was to evaluate clinically an adjunct method of plaque remo...

J. P. Williams G. M. Bowers G. B. Pelleu



Effect of toothbrush grip on plaque removal during manual toothbrushing in children.  


Toothbrushing is fundamental to oral hygiene. Children differ in manual dexterity and their grip on toothbrushes. We videotaped toothbrushing sessions and observed the grip type, duration of brushing, and brushing technique used among 100 children aged 8-12 years. We then investigated the association between grip type and plaque removal, using plaque scores obtained at various time points. We further examined the effect on plaque scores of standardizing both brushing technique and duration among the same participants. The most common grip was the distal oblique, followed by the oblique; the spoon and precision grips were rare, and no child used a power grip. Mean brushing duration for most children was 1.43 ± 0.85 min, and the most common brushing technique was horizontal scrubbing. We conclude that grip preference is inherent and that the distal oblique grip was better than the oblique grip in removing plaque. PMID:22790411

Sharma, Sarika; Yeluri, Ramakrishna; Jain, Amit A; Munshi, Autar K



Comparison of plaque removal efficacy of new and 3-month-old toothbrushes in children.  


The cost of replacing toothbrushes at frequent intervals may be prohibitive in underdeveloped countries. The objective of this study in Tehran was to compare the plaque removal efficacy of new and 3-month-old toothbrushes in children. In a randomized, crossover study, 93 children aged 7-9 years old received a new manual toothbrush to use twice per day for 3 months. Plaque scores were measured using the modified Quigley-Hein plaque index after children had brushed for 60 seconds with either a new or their used toothbrush. Bristle wear of worn brushes was assessed by measuring brushing surface areas on digital images. Compared with new brushes in the same subjects, no statistically significant differences were found for plaque score reductions for 3-month-old toothbrushes exhibiting various degrees of wear. Worn toothbrushes are equally effective as new ones for children. PMID:21735945

Malekafzali, B; Biria, M; Tadayon, N; Abbasi, H



Antigenicity, pathogenicity, and immunogenicity of small and large plaque infectious bursal disease virus clones.  


A serotype 1 variant strain of infectious bursal disease virus designated IN was passaged 40 times in BGM-70 cell line. A small plaque (SP) clone and a large plaque (LP) clone were then isolated and plaque purified four times. The SP and LP viruses formed circular plaques about 0.5 mm and 6.0 mm in diameter, respectively. Both clones lost their pathogenicity for specific-pathogen-free (SPF) chickens and did not elicit significant levels of virus-neutralizing antibody titers. However, the SP and LP clones maintained their immunogenicity when used as inactivated vaccines in SPF chickens. The restriction enzyme profiles of both clones were similar. Back passage of the SP and LP clones in SPF chickens resulted in loss of their phenotypic characteristics. PMID:8980814

Hassan, M K; Nielsen, C K; Ward, L A; Jackwood, D J; Saif, Y M


Inraoperative and Histological Visualization of Disrupted Vulnerable Plaques following Diagnostic Angiography of Moderate Carotid Stenosis.  


Background. Digital subtraction angiography (DSA) remains an important tool for diagnosis of carotid stenosis but is associated with risk for periprocedural complications. This is the first report of direct intraoperative and histolopathologic visualization of DSA-related carotid plaque disruption. Case. A 64-year-old man diagnosed to have a 60% right carotid stenosis received diagnostic DSA for therapeutic decision-making. He developed transient left hand numbness and weakness immediately after the procedure. Intraoperative imaging during carotid endarterectomy revealed a fragile plaque with sharp surface laceration and intraplaque hemorrhage at the bifurcation. Microscopy of the specimen demonstrated a large atheromatous plaque with fibrous hypertrophy and intraplaque hemorrhage filled with recent hemorrhagic debris. Conclusion. The visualized carotid lesion was more serious than expected, warning the danger of embolization or occlusion associated with the catheter maneuvers. Thus the highest level of practitioner training and technical expertise that ensures precise assessment of plaque characteristics should be encouraged. PMID:20700419

Mutoh, Tatsushi; Ishikawa, Tatsuya; Suzuki, Akifumi; Yasui, Nobuyuki



Selective absorption of ultraviolet laser energy by human atherosclerotic plaque treated with tetracycline  

SciTech Connect

Tetracycline is an antibiotic that absorbs ultraviolet light at 355 nm and preferentially binds to atherosclerotic plaque both in vitro and in vivo. Tetracycline-treated human cadaveric aorta was compared with untreated aorta using several techniques: absorptive spectrophotometry; and tissue uptake of radiolabeled tetracycline, which showed 4-fold greater uptake by atheroma than by normal vessel. In addition, intravenous tetracycline administered to patients undergoing vascular surgery demonstrated characteristic fluorescence in surgically excised diseased arteries. Because of tetracycline's unique properties, the authors exposed tetracycline-treated and untreated aorta to ultraviolet laser radiation at a wavelength of 355 nm. They found enhanced ablation of tetracycline-treated atheroma compared with untreated atheroma. The plaque ablation caused by ultraviolet laser radiation was twice as extensive in tetracycline-treated vs nontreated plaque. This study demonstrates the potential of tetracycline plaque enhancement for the selective destruction of atheroma by ultraviolet laser radiation.

Murphy-Chutorian, D.; Kosek, J.; Mok, W.; Quay, S.; Huestis, W.; Mehigan, J.; Profitt, D.; Ginsburg, R.



The onset and progression of atherosclerotic plaques as related to arterial wall changes.  


The coronary arterial beds from more than 1200 subjects aged 1 to 65 years were investigated by both histopathological, histochemical and morphometric methods. Light microscopic aspects were analysed to reveal if plaque development and progression toward obstructive lesions were associated with arterial wall changes, particularly of the intimal connective tissue adjacent to lesions. Six patterns of plaque development in the coronary arterial tree were delineated, emphasis being placed on the observation that the onset and progression of plaques frequently appeared independent of arterial wall changes, in contrast to fatty streaks, gelatinous lesions, intimal necrotic areas, incorporated microthrombi and intramural thrombi. Our results support the view that plaques develop and progress on their own, superimposed on a preexisting arterial wall microarchitecture. PMID:1784938

Velican, D; Velican, C; St?nescu, C


Vulnerable plaque: Detection of agreement between multi-detector-row CT angiography and US-ECD  

Microsoft Academic Search

ObjectivesThe purpose of this work was to evaluate the agreement between ultra-sound echo-color Doppler (US-ECD) and multi-detector-row CT angiography (MDCTA) in the characterization of vulnerable plaque.

Luca Saba; Roberto Sanfilippo; Roberto Montisci; Matteo Atzeni; Diego Ribuffo; Giorgio Mallarini



Development and Evaluation of Self-Applied Plaque Indices for Children.  

National Technical Information Service (NTIS)

An aim of preventive dentistry is to convince individuals to remove accumulated plaque from their teeth daily by toothbrushing and flossing. This contract attempted to develop a self-administered feedback measure to permit them to judge their own performa...

H. G. Hunter C. D. Fink



Effects of carbon dioxide, Nd-YAG, and argon laser radiation on coronary atheromatous plaques.  


Laser radiation has been successfully applied in several areas of medical practice. However, its use in cardiology and specifically its effects on obstructive atherosclerosis have largely been unexplored. To evaluate effects of laser radiation on atherosclerotic plaques 25 fresh necropsy atherosclerotic coronary artery segments were exposed to laser radiation with either a carbon dioxide, Nd-YAG, or argon laser. Split or intact segments were prepared under dry conditions or while immersed in saline solution or blood and exposed to laser radiation as power and duration of exposure varied. All 3 lasers were capable of creating controlled injury to atherosclerotic plaques. In general, the magnitude of injury varied according to the total energy delivered (that is, power times duration of exposure. Calcified and noncalcified plaques were penetrated with similar levels of injury. Histologic examination demonstrated that laser radiation produced a wedge incision in the atherosclerotic plaque which was surrounded by zones of thermal and acoustic injury. PMID:6816057

Abela, G S; Normann, S; Cohen, D; Feldman, R L; Geiser, E A; Conti, C R



Paradoxic Decreases in Atherosclerotic Plaque Mass in Insulin-Treated Diabetic Patients  

Microsoft Academic Search

This study assessed the impact of diabetes mellitus on atherosclerotic lesion formation. Seventy insulin-treated diabetics, 150 non–insulin-treated diabetics, and 607 nondiabetics with chronic anginal syndomes and de novo native coronary stenoses were studied using (1) angiography, and (2) intravascular ultrasound (reference and lesion arterial, lumen, and plaque areas; area stenosis [reference-lesion\\/reference lumen area]; remodeling index [reference-lesion lumen area\\/lesion-reference plaque area];

Ran Kornowski; Gary S. Mintz; Alexandra J. Lansky; Mun K. Hong; Kenneth M. Kent; August D. Pichard; Lowell F. Satler; Jeffrey J. Popma; Theresa A. Bucher; Martin B. Leon




Microsoft Academic Search

This study aimed to investigate the effects of some snack foods on plaque pH in children with different levels of mutans streptococci (MS). Six children, aged 9-12 years, with low (<104) and 6 children, aged 10-12 years, with high (>106) numbers of MS\\/ml saliva partici- pated in the study. Dental plaque pH changes, after the consumption of milk chocolate, sweet

Sroisiri Thaweboon; Theeralaksana Suddhasthira; Boonyanit Thaweboon; Surin Soo-Ampon; Surachai Dechkunakorn



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



Risk Factors for Cataract After Palladium103 Ophthalmic Plaque Radiation Therapy  

Microsoft Academic Search

Purpose: To examine how tumor characteristics and dose affect cataract development after plaque radiation therapy. Methods and Materials: Three hundred and eighty-four patients were diagnosed with uveal melanoma and treated with palladium-103 (¹°³Pd) plaque radiation therapy. Of these, 282 (74%) inclusion met exclusion criteria for follow-up time, tumor location, and phakic status. Then patient-, ophthalmic-, and radiation-specific factors (patient age,

Paul T. Finger; Kimberly J. Chin; Guo-Pei Yu; Neil S. Patel



Diagnosis of Vulnerable Atherosclerotic Plaques by Time-Resolved Fluorescence Spectroscopy and Ultrasound Imaging  

Microsoft Academic Search

In this study, time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and ultrasonography were applied to detect vulnerable (high-risk) atherosclerotic plaque. A total of 813 TR-LIFS measurements were taken from carotid plaques of 65 patients, and subsequently analyzed using the Laguerre deconvolution technique. The investigated spots were classified by histopathology as thin, fibrotic, calcified, low-inflamed, inflamed and necrotic lesions. Spectral and time-resolved parameters

J. A. Jo; Q. Fang; T. Papaioannou; J. H. Qiao; M. C. Fishbein; B. Beseth; A. H. Dorafshar; T. Reil; D. Baker; J. Freischlag; K. K. Shung; L. Sun; L. Marcu



Measurement of Color Parameters of Psoriatic Plaques by Narrow-Band Reflectance Spectrophotometry and Tristimulus Colorimetry  

Microsoft Academic Search

Color parameters were measured on 50 psoriatic plaques in 10 patients, after scoring the amount of scales on them by inspection, with a narrow-band reflectance spectrophotometer (erythema\\/melanin index expression) and tristimulus colorimeter (CIE L*a*b* expression). Both erythema index and a* (redness) were highest in the group of erythematous plaque with little scale (twice as high as in controls) and decreased

Hirotsugu Takiwaki; Jørgen Serup



Fabrication of Ni-Plaque-Based Manganese Dioxide Electrodes for Electrochemical Supercapacitors  

Microsoft Academic Search

Chemical and electrochemical impregnation methods have been developed for the fabrication of manganese dioxide electrodes for electrochemical supercapacitors using Ni plaques as current collectors. The methods enabled the synthesis of manganese dioxide in-situ in pores of Ni plaques. The chemical method was based on the reduction of KMnO4 solutions with isopropanol. Cathodic galvanostatic method and reverse pulse electrosynthesis method were

Yaohui Wang; Quan Min Yang; Igor Zhitomirsky



Fabrication of Ni-plaque Based Manganese Dioxide Electrodes for Electrochemical Supercapacitors  

Microsoft Academic Search

Chemical and electrochemical impregnation methods have been developed for the fabrication of manganese dioxide electrodes for electrochemical supercapacitors using Ni plaques as current collectors. The methods enabled the synthesis of manganese dioxide in-situ in pores of Ni plaques. Chemical method was based on the reduction of KMnO4 solutions with isopropanol. Cathodic galvanostatic method and reverse pulse electrosynthesis method were investigated

Yaohui Wang; Quan Min Yang; Igor Zhitomirsky



Plaque pH response to snack foods in children with different levels of mutans streptococci.  


This study aimed to investigate the effects of some snack foods on plaque pH in children with different levels of mutans streptococci (MS). Six children, aged 9-12 years, with low (<10(4)) and 6 children, aged 10-12 years, with high (>106) numbers of MS/ml saliva participated in the study. Dental plaque pH changes, after the consumption of milk chocolate, sweet biscuit, instant noodle, sticky rice with banana and a 10% sucrose positive control were measured using pH-electrode. The measurements of plaque pH were made on forty-eight-hour accumulated plaque, at baseline to determine the resting pH of the fasted plaque and at time intervals of 2, 5, 10, 20 and 30 minutes after food consumption. The plaque pH curves, delta pH values and area under curve for pH 6.0 for each test food were determined. Plaque acidogenicity was more pronounced for the high-MS group at almost all test periods compared to the low-MS group with all test foods. The test foods were ranked according to maximum pH drop in about the same order in both groups as follows: 10% sucrose > milk chocolate > sweet biscuit > sticky rice with banana > instant noodle. The plaque pH also stayed below pH 6.00 for a longer period in the high-MS group with sweet biscuit, milk chocolate, and sticky rice with banana. Findings suggest that pH responses were more acidic in high-MS group than low-MS group. PMID:17877240

Thaweboon, Sroisiri; Suddhasthira, Theeralaksana; Thaweboon, Boonyanit; Soo-Ampon, Surin; Dechkunakorn, Surachai



Comparison of different methods to detect Helicobacter pylori in the dental plaque of dyspeptic patients  

Microsoft Academic Search

The aim of this study was to compare different methods of detection of Helicobacter pylori (H. pylori) in the dental plaque of dyspeptic patients. After recording the clinical indices, culture and polymerase chain reaction\\u000a (PCR) methods were performed on plaque samples, while rapid urease test in addition to these tests was carried on gastric\\u000a samples from 67 dyspeptic patients who

Idil Teoman; Nurdan Özmeriç; Gönen Özcan; Emine Alaaddino?lu; ?ükrü Dumlu; Yakut Akyön; Köksal Balo?



Effect of X-Rays on Plaque-forming Ability of Vesicular Stomatitis Virus  

Microsoft Academic Search

THE animal virus vesicular stomatitis can be easily propagated in tissue cultures and quantitatively assayed by the plaque-count technique using tissue cell monolayers1,2. In preliminary experiments dealing with X-ray inactivation of vesicular stomatitis virus, several morphological plaque-type variants were observed among the irradiated survivors. This observation suggested that vesicular stomatitis virus offers additional material for radiobiological and genetic studies on

I. L. Shechmeister; Ralph St. John



Evaluation of Human and Simian Immunodeficiency Virus Plaque and Neutralization Assays  

Microsoft Academic Search

SUMMARY A number of CD4 ÷ T cell lines were compared for their ability to act as target cells for human immunodeficiency virus (HIV) infection in syncytium- and plaque-forming assays. MT-4 and C8166 cells were the most sensitive indicator cells for HIV- and simian immunodeficiency virus (SIV)-induced cytopathic effects, and gave rise to macroscopic (MT-4) and microscopic (C8166) plaques. The

J. A. McKeating; A. McKnight; K. McIntosh; P. R. Clapham; C. Mulder; R. A. Weiss



Carotid intima-media thickness and plaque occurrence in predicting stable angiographic coronary artery disease  

PubMed Central

Background Carotid intima-media thickness (CIMT) and plaque formation have been used as surrogate end-points for evaluating the regression and/or progression of atherosclerotic cardiovascular disease, but their predictive value for stable coronary artery disease (CAD) is inconclusive. Methods Carotid ultrasonography was performed in patients who underwent noninvasive multislice computed tomography (MSCT) angiography for CAD suspected, due to chest pain. CIMT and plaque formation on the left and right common carotid arteries (CCAs), carotid bulb (CB), and proximal internal carotid arteries (ICAs) were evaluated, and the relationship between angiographic CAD, CIMT, and plaque formation was determined. Results 120 patients (95 male; 25 female), with a mean age ± standard deviation of 61 ± 11 years (range: 35–89 years) were recruited. Because age had a significant impact on CAD (r = 0.191; P = 0.036), CCA plaques (r = 0.368; P = 0.001), ICA plaques (r = 0.334; P = 0.004), and mean CIMT (r = 0.436; P = 0.001), patients were divided into two groups aged <60 years and ?60 years. In the <60 years group, CIMT-CB was significantly higher in patients with CAD (P = 0.041), while in the ?60 years group, mean CIMT, CIMT-CCA, and CIMT-CB were significantly higher in patients with CAD (P < 0.05, for each). In both groups, the occurrence of carotid plaques was significantly higher in patients with CAD than in those without CAD (P < 0.007, for each). After controlling for other risk factors, carotid plaques were an independent predictor of CAD in both groups (P < 0.05, for each), while CIMT-CB could independently predict CAD only in patients ?60 years old (P = 0.031). Conclusion Our findings suggest that carotid plaques are a strong predictor of stable CAD. However, CIMT-CB could predict stable CAD only in patients over 60 years of age.

Chang, Chao-Chien; Chang, Mei-Ling; Huang, Chi-Hung; Chou, Po-Ching; Ong, Eng-Thiam; Chin, Chih-Hui



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.

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



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

Microsoft Academic Search

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

M. E. Jensen



Comparative Plaque Acidogenesis of Caries-resistant vs. Caries-susceptible Adults  

Microsoft Academic Search

The authors conducted a comparative study of plaque acids in three-day fasting or resting plaque samples from ten pairs of caries-resistant (CR) and caries-susceptible (CS) subjects chewing a sucrose gum for a period of 45 min. The study disclosed two important differences: 1) The amount and rate of production of lactic acid were lower in the CR group, especially at

S. M. Vratsanos; I. D. Mandel



Bayes Clustering and Structural Support Vector Machines for Segmentation of Carotid Artery Plaques in Multicontrast MRI  

PubMed Central

Accurate segmentation of carotid artery plaque in MR images is not only a key part but also an essential step for in vivo plaque analysis. Due to the indistinct MR images, it is very difficult to implement the automatic segmentation. Two kinds of classification models, that is, Bayes clustering and SSVM, are introduced in this paper to segment the internal lumen wall of carotid artery. The comparative experimental results show the segmentation performance of SSVM is better than Bayes.

Guan, Qiu; Du, Bin; Teng, Zhongzhao; Gillard, Jonathan; Chen, Shengyong



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



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


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



Association of Caries Activity with the Composition of Dental Plaque Fluid  

Microsoft Academic Search

This study tests the hypothesis that caries activity is associated with lower degrees of saturation with respect to enamel mineral in dental plaque fluid following sucrose exposure. Plaque fluids were obtained from caries-free, caries-positive, and caries-active subjects. Samples were collected before and at 3 and 7 min after a sucrose rinse on consecutive weeks and analyzed for organic acids, inorganic

X. J. Gao; Y. Fan; R. L. Kent; J. Van Houte; H. C. Margolis



Formation and maintenance of Alzheimer's disease beta-amyloid plaques in the absence of microglia.  


In Alzheimer's disease, microglia cluster around beta-amyloid deposits, suggesting that these cells are important for amyloid plaque formation, maintenance and/or clearance. We crossed two distinct APP transgenic mouse strains with CD11b-HSVTK mice, in which nearly complete ablation of microglia was achieved for up to 4 weeks after ganciclovir application. Neither amyloid plaque formation and maintenance nor amyloid-associated neuritic dystrophy depended on the presence of microglia. PMID:19838177

Grathwohl, Stefan A; Kälin, Roland E; Bolmont, Tristan; Prokop, Stefan; Winkelmann, Georg; Kaeser, Stephan A; Odenthal, Jörg; Radde, Rebecca; Eldh, Therese; Gandy, Sam; Aguzzi, Adriano; Staufenbiel, Matthias; Mathews, Paul M; Wolburg, Hartwig; Heppner, Frank L; Jucker, Mathias



Variation in atherosclerotic plaque composition according to increasing coronary artery calcium scores on computed tomography angiography  

Microsoft Academic Search

Increasing coronary artery calcium scores (CACS) are independently associated with cardiac events. Recent advents in coronary\\u000a computed tomography angiography (CCTA) have allowed us to better characterize individual plaque. Currently, it is unknown\\u000a if higher CACS are likely to be associated with more calcified or mixed and heterogeneous plaque burden on CCTA. The study\\u000a population consisted of 1,043 South Korean asymptomatic

Khurram Nasir; Juan J. Rivera; Yeonyee E. Yoon; Sung-A Chang; Sang-iI Choi; Eun-Ju Chun; Dong-Joo Choi; Matthew J. Budoff; Roger S. Blumenthal; Hyuk-Jae Chang



The culprit lesion score on multi-detector computed tomography can detect vulnerable coronary artery plaque  

Microsoft Academic Search

Vulnerable plaques are characterized by large lipid cores, positive remodeling and small coronary calcium deposits. Multi-detector\\u000a computed tomography (MDCT) has recently been shown to be able to characterize coronary artery plaques. The aim of this study\\u000a was to evaluate culprit coronary lesions for differentiating acute coronary syndrome (ACS) from stable angina pectoris (SAP)\\u000a using MDCT. 64-slice MDCT was conducted on

So Yeon Kim; Kee-Sik Kim; Myeung Joon Seung; Jin Wook Chung; Jeung Hyeun Kim; Sung Hee Mun; Young Soo Lee; Jin Bae Lee; Jae Kean Ryu; Ji Yong Choi; Sung Gug Chang



Noninvasive evaluation of coronary artery plaque with electrocardiographically-gated multislice computed tomography  

Microsoft Academic Search

The study evaluated the feasibility of determining coronary lesion configuration, including coronary plaque, stenosis and calcification, by ECG-gated MSCT. The results were compared with the characteristics of intravascular ultrasound (IVUS). The overall sensitivity for diagnosing significant coronary stenosis was 80.2%, and the specificity was 95.6%. There were significant differences in plaque density among three groups (p<0.01). MSCT was feasible for

Shinro Matsuo; Ichiro Nakae; Tetsuya Matsumoto; Minoru Horie



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


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



Drug-Eluting Stents: A Potential Preemptive Treatment Choice for Vulnerable Coronary Plaques  

Microsoft Academic Search

\\u000a Restenosis, a major limitation of percutaneous transluminal coronary angioplasty, has been dramatically reduced by the use\\u000a of drug-eluting stents (DES). Because the majority of acute coronary events occur at nonobstructive lesions that are vulnerable,\\u000a it has been suggested that prophylactic stenting of vulnerable plaques (VP) to prevent further plaque instability, thereby\\u000a preventing future coronary events, is as a reasonable strategy.

Edwin Lee; George Dangas; Roxana Mehran


IMPY: an improved thioflavin-T derivative for in vivo labeling of ?-amyloid plaques  

Microsoft Academic Search

Development of small molecular probes for in vivo labeling and detection of ?-amyloid (A?) plaques in patients of Alzheimer’s disease (AD) is of significant scientific interest, and it may also assist the development of drugs targeting A? plaques for treatment of AD. A novel probe, [123I\\/125I]IMPY, 6-iodo-2-(4?-dimethylamino-)phenyl-imidazo[1,2-a]pyridine, was successfully prepared with an iododestannylation reaction catalyzed by hydrogen peroxide. The modified

Mei-Ping Kung; Catherine Hou; Zhi-Ping Zhuang; Bin Zhang; Daniel Skovronsky; John Q Trojanowski; Virginia M.-Y Lee; Hank F Kung



Carotid plaque compared with intima-media thickness as a predictor of coronary and cerebrovascular disease  

Microsoft Academic Search

Atherosclerosis is the underlying cause of most myocardial infarction (MI) and ischemic strokes. B-mode ultrasound of carotid\\u000a arteries provides measures of intima-media thickness (IMT) and plaques, both widely used as surrogate measures of cardiovascular\\u000a disease. Although IMT and plaques are highly inter-correlated, IMT’s role as a marker of atherosclerosis has been questioned,\\u000a especially when measurements include the common carotid artery

Stein Harald Johnsen; Ellisiv B. Mathiesen



Elevated White Blood Cell Count and Carotid Plaque Thickness The Northern Manhattan Stroke Study  

Microsoft Academic Search

Background and Purpose—Elevated leukocyte count has been associated with cardiovascular and cerebrovascular disease in several epidemiological studies. We sought to determine whether white blood cell count (WBC) is associated with carotid plaque thickness in a stroke-free, multiethnic cohort. Methods—For this cross-sectional analysis, WBC was measured in stroke-free community subjects undergoing carotid duplex Doppler ultrasound. Maximal internal carotid plaque thickness (MICPT)

Mitchell S. Elkind; Jianfeng Cheng; Bernadette Boden-Albala; Myunghee C. Paik; Ralph L. Sacco


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.



Lymphoplasmacytic plaque in children: a report of two new cases with review of the literature.  


Lymphoplasmacytic plaque in children has been proposed as a rare, emerging clinicopathologic entity characterized by solitary, extratruncal, asymptomatic papules and plaques that are typically found in healthy young Caucasian females. Biopsy of these lesions reveals a dermal lymphoplasmacytic infiltrate with or without epithelioid granulomas. Two unique patients with lymphoplasmacytic plaque in children are presented in this report, including a 26-month-old female with a lesion on her finger, who represents both the youngest described patient and the first documented with a finger lesion, as well as a 17-year-old young woman with a left thigh lesion, who represents the patient with the longest clinically and histopathologically observed lesion to date. These two additional patients corroborate the experience of lymphoplasmacytic plaque in children in the six previously reported cases and further expand the clinicopathologic spectrum of the disease. Recognition of lymphoplasmacytic plaque in children is important to facilitate distinction from potential differential considerations, including lymphoproliferative disorders and infectious conditions, particularly as the experience to date appears to suggest that lymphoplasmacytic plaque in children represent a reactive (pseudolymphomatous) condition. PMID:23167476

Porto, Dennis A; Sutton, Stephanie; Wilson, Joshua B; Scupham, Richard K; Stone, Mary S; Liu, Vincent



High Zn content of Randall's plaque: a ?-X-ray fluorescence investigation.  


Kidney stone disease, or nephrolithiasis, is a common ailment. Among the different risk factors usually associated with nephrolithiasis are dehydration, metabolic defects (especially with regard to calcium and oxalate). The presence of a mineral deposit at the surface of the renal papilla (termed Randall's plaque) has all been recently underlined. Of note, Randall's plaque is made of the calcium phosphate, carbapatite, and serves as a nucleus for kidney stone formation. The process by which apatite nanocrystals nucleate and form Randall's plaque remains unclear. This paper deals with the possible relationship between trace elements and the formation of this mineral. The investigation has been performed on a set of Randall's plaques, extracted from human kidney stones, through ?-X-ray diffraction and ?-X-ray fluorescence analyses in order to determine the chemical composition of the plaque as well as the nature and the amount of trace elements. Our data provide evidence that Zn levels are dramatically increased in carbapatite of RP by comparison to carbapatite in kidney stones, suggesting that calcified deposits within the medullar interstitium are a pathological process involving a tissue reaction. Further studies, perhaps including the investigation of biomarkers for inflammation, are necessary for clarifying the role of Zn in Randall's plaque formation. PMID:21763116

Carpentier, Xavier; Bazin, Dominique; Combes, Christelle; Mazouyes, Aurélie; Rouzière, Stephan; Albouy, Pierre Antoine; Foy, Eddy; Daudon, Michel



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.

Chaichana, Thanapong; Sun, Zhonghua; Jewkes, James



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


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



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

PubMed Central

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

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



Characterization of carotid atherosclerotic plaques using frequency-based texture analysis and bootstrap.  


Texture analysis of B-mode ultrasound images of carotid atheromatous plaque can be valuable for the accurate diagnosis of atherosclerosis. In this paper, two frequency-based texture analysis methods based on the Fourier Power Spectrum and the Wavelet Transform were used to characterize atheromatous plaques. B-mode ultrasound images of 10 symptomatic and 9 asymptomatic plaques were interrogated. A total of 109 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, three features were found to be significantly different between the two types of plaques: the average value of the angular distribution corresponding to the wedge centered at 90 degrees, the standard deviation at scale 1 derived from the horizontal detail image, and the standard deviation at scale 2 derived from the horizontal detail image. It is concluded that frequency-based texture analysis in combination with a powerful statistical technique, such as bootstrapping, may provide valuable information about the plaque tissue type. PMID:17946957

Stoitsis, J; Tsiaparas, N; Golemati, S; Nikita, K S



Evaluation of knowledge and plaque scores in school children before and after health education  

PubMed Central

Background: Health education is a process of transmission of knowledge and skills necessary for improvement in quality of life. The purpose of the present study was to evaluate the oral hygiene related knowledge and plaque scores of 12-year-old school children in Belgaum city before and after health education. Methods: Three schools of Belgaum city were randomly selected and assigned into one of three health educational groups – group I (audiovisual aids), group II (chalk and blackboard) and group III (no health education). Oral health related knowledge and plaque scores were assessed in all the groups before and after health education. Results: The mean knowledge score before intervention in group I was 7.94, in group II was 7.86 and in group III was 7.74 (P=0.86). After intervention, the mean knowledge score was 14.42 in group I, 12.7 in group II and 9.58 in group III (P<0.001). Plaque scores in the three groups were similar and statistically nonsignificant at baseline. After the oral health education, the mean plaque scores were 0.627 in group I, 0.8826 in group II and 1.0156 in group III. Within the group comparisons revealed a statistically improved oral hygiene with decreased plaque scores in all the three groups. Conclusion: Health education by audiovisual aids could be an effective preventive measure against plaque-related oral diseases.

Hebbal, Mamata; Ankola, Anil V.; Vadavi, Deepti; Patel, Kunal



Hemodynamic Instability during Carotid Angioplasty and Stenting-Relationship of Calcified Plaque and Its Characteristics  

PubMed Central

Purpose During carotid angioplasty and stenting (CAS), hemodynamic instability (HDI) can occur, possibly causing post-procedural ischemic complications. The goal of this study was to investigate the risk factors of HDI focusing on characteristics of plaque. Materials and Methods Thirty nine CAS patients were retrospectively evaluated for HDI. Prolonged HDI that lasted over 30 minutes was analyzed in relation to characteristics of calcified plaque. Results Nineteen (48.7%) patients had HDI. Ten of the 19 had both bradycardia and hypotension, and nine had only bradycardia. All bradycardia was treated well with a transcutaneous temporary cardiac pacemaker. But eight patients presented with prolonged hypotension in spite of recovery of bradycardia. Calcified plaque was a related factor associated with HDI (odds ratio, 8.571; 95% confidence interval, 1.321-55.62; p=0.024). Extensive and eccentric type calcified plaques were associated with prolonged hypotension (p=0.04, and p=0.028, respectively). Conclusion The calcification of plaque is a predictable factor of HDI during CAS, and its extensive and eccentric calcified plaques may be related to prolonged HDI.

Jeon, Jin Sue; Hwang, Gyojun



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


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

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



Apoptosis of human vascular smooth muscle cells derived from normal vessels and coronary atherosclerotic plaques.  

PubMed Central

We studied death of human vascular smooth muscle cells derived from coronary plaques and normal coronary arteries and aorta. Cells from normal arteries underwent death only upon removal of serum growth factors. In contrast, plaque-derived cells died even in high serum conditions, and death increased after serum withdrawal. Death was characteristically by apoptosis in both normal and plaque-derived cells, as determined by time-lapse videomicroscopy, electron microscopy, and DNA fragmentation patterns. IGF-1 and PDGF were identified as potent survival factors in serum, whereas EGF and basic fibroblast growth factor had little effect. Stable expression of bcl-2, a protooncogene that regulates apoptosis in other cell lines, protected smooth muscle cells from apoptosis, although there was no detectable difference in endogenous bcl-2 expression between cells from plaques or normal vessels. We conclude that apoptosis of human vascular smooth muscle cells is regulated by both specific gene products and local cytokines acting as survival factors. Apoptosis may therefore regulate cell mass in the normal arterial wall and the higher rates of apoptosis seen in plaque smooth muscle cells may ultimately contribute to plaque rupture and breakdown and thus to the clinical sequelae of atherosclerosis. Images

Bennett, M R; Evan, G I; Schwartz, S M



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


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

Zhu, Ying; Yin, John



Iron plaques improve the oxygen supply to root meristems of the freshwater plant, Lobelia dortmanna.  


* High radial oxygen loss (ROL) from roots of aquatic plants to reduced sediments is thought to deplete the roots of oxygen and restrict the distribution of those species unable to form a barrier to oxygen loss. Metal precipitates with high iron content (Fe-plaques) frequently form on roots of aquatic plants and could create such a diffusion barrier, thereby diverting a larger proportion of downward oxygen transport to the root meristems. * To investigate whether Fe-plaques form a barrier to oxygen loss, ROL and internal oxygen concentrations were measured along the length of roots of the freshwater plant Lobelia dortmanna using platinum sleeve electrodes and Clark-type microelectrodes. * Measurements showed that ROL was indeed lower from roots with Fe-plaques than roots without plaques and that ROL declined gradually with thicker iron coating on roots. The low ROL was caused by low diffusion coefficients through root walls with Fe-plaques resulting in higher internal oxygen concentrations in the root lacunae. * By diverting a larger proportion of downward oxygen transport to root meristems in L. dortmanna, the presence of Fe-plaques should diminish root anoxia and improve survival in reduced sediments. PMID:18513220

Møller, Claus Lindskov; Sand-Jensen, Kaj