Variability and accuracy of coronary CT angiography including use of iterative reconstruction algorithms for plaque burden assessment as compared with intravascular ultrasound - an ex vivo study

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Stolzmann, Paul [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Schlett, Christopher L.; Maurovich-Horvat, Pal; Scheffel, Hans; Engel, Leif-Christopher; Karolyi, Mihaly; Hoffmann, Udo [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); Maehara, Akiko; Ma, Shixin; Mintz, Gary S. [Columbia University Medical Center, Cardiovascular Research Foundation, New York, NY (United States)

2012-10-15

To systematically assess inter-technique and inter-/intra-reader variability of coronary CT angiography (CTA) to measure plaque burden compared with intravascular ultrasound (IVUS) and to determine whether iterative reconstruction algorithms affect variability. IVUS and CTA data were acquired from nine human coronary arteries ex vivo. CT images were reconstructed using filtered back projection (FBPR) and iterative reconstruction algorithms: adaptive-statistical (ASIR) and model-based (MBIR). After co-registration of 284 cross-sections between IVUS and CTA, two readers manually delineated the cross-sectional plaque area in all images presented in random order. Average plaque burden by IVUS was 63.7 {+-} 10.7% and correlated significantly with all CTA measurements (r = 0.45-0.52; P < 0.001), while CTA overestimated the burden by 10 {+-} 10%. There were no significant differences among FBPR, ASIR and MBIR (P > 0.05). Increased overestimation was associated with smaller plaques, eccentricity and calcification (P < 0.001). Reproducibility of plaque burden by CTA and IVUS datasets was excellent with a low mean intra-/inter-reader variability of <1/<4% for CTA and <0.5/<1% for IVUS respectively (P < 0.05) with no significant difference between CT reconstruction algorithms (P > 0.05). In ex vivo coronary arteries, plaque burden by coronary CTA had extremely low inter-/intra-reader variability and correlated significantly with IVUS measurements. Accuracy as well as reader reliability were independent of CT image reconstruction algorithm. (orig.)

A study of disrupted carotid plaque using high-resolution MRI

International Nuclear Information System (INIS)

Yu Wei; Zhang Zhaoqi; Underhill, H.; Hatsukami, T.S.; Chun, Y.

2008-01-01

Objective: To evaluate distribution features of disrupted carotid plaque. Methods: Forty-three subjects with duplex ultrasound evidence of 50% to 99% stenosis were retrospectively analyzed. Plaques were categorized as disrupted if there was MRI evidence of fibrous cap rupture. Quantity measured areas of the lumen (LA), wall (WA), and plaque components. The morphological parameters used were total vessel area, vessel burden index, eccentricity index. Mann-Whitney test and Chi-square test appropriate used SPSS (v. 12.0). Results: There were 17 disrupted and 26 undisrupted lesions identified for comparison. Disrupted plaques showed a predominance of longer longitudinal length of large lip nucleus along the vessel wall (6 mm vs. 0 mm, U=126, P 2 vs. 30.18 mm 2 U=138 P<0.05) and a longer segment of stenosis when compared with the intact plaques. Conclusions: Disrupted plaques have significantly different characteristics in terms of both axial and longitudinal distribution. A combination of multi-plane and multi-contrast high resolution MRI may provide valuable information about overall lesion morphology and its association to vulnerability. (authors)

Optical coherence tomography plaque characterization in a patient with ST segment elevation myocardial infarction after cocaine intake

International Nuclear Information System (INIS)

Hansen, Morten Steen Svarer; Antonsen, Lisbeth; Jensen, Lisette Okkels

2016-01-01

A 28-year old man presented to the Emergency Department with malaise after cocaine intake. After arrival he developed retrosternal chest pain and the electrocardiogram showed ST segment elevations in V1-V2 and ST segment depressions in V5-V6. An acute coronary angiogram revealed a focal non-occlusive lesion with thrombus in the left anterior descending artery. Supplementary optical coherence tomography (OCT) detected plaque erosion with adherent thrombus to be the responsible underlying pathophysiological mechanism. The patient received an effective antithrombotic regimen. Repeat angiogram with additional OCT one month later documented thrombus resolution and complete restoration of the previously eroded coronary vascular surface area. - Highlights: • Optical coherence tomography (OCT) was used to characterize a coronary artery plaque. • OCT detected coronary plaque erosion in a young male with MI due to cocaine abuse. • OCT was used to document thrombus resolution.

Optical coherence tomography plaque characterization in a patient with ST segment elevation myocardial infarction after cocaine intake

Energy Technology Data Exchange (ETDEWEB)

Hansen, Morten Steen Svarer, E-mail: morten.steen.hansen2@rsyd.dk [Emergency Department, Kolding Hospital, Skovvangen 2-8, DK-6000 Kolding (Denmark); Antonsen, Lisbeth; Jensen, Lisette Okkels [Department of Cardiology, Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense (Denmark)

2016-04-15

A 28-year old man presented to the Emergency Department with malaise after cocaine intake. After arrival he developed retrosternal chest pain and the electrocardiogram showed ST segment elevations in V1-V2 and ST segment depressions in V5-V6. An acute coronary angiogram revealed a focal non-occlusive lesion with thrombus in the left anterior descending artery. Supplementary optical coherence tomography (OCT) detected plaque erosion with adherent thrombus to be the responsible underlying pathophysiological mechanism. The patient received an effective antithrombotic regimen. Repeat angiogram with additional OCT one month later documented thrombus resolution and complete restoration of the previously eroded coronary vascular surface area. - Highlights: • Optical coherence tomography (OCT) was used to characterize a coronary artery plaque. • OCT detected coronary plaque erosion in a young male with MI due to cocaine abuse. • OCT was used to document thrombus resolution.

Topographic association of angioscopic yellow plaques with coronary atherosclerotic plaque: assessment with quantitative colorimetry in human coronary artery autopsy specimens.

Science.gov (United States)

Ishibashi, Fumiyuki; Lisauskas, Jennifer B; Kawamura, Akio; Waxman, Sergio

2008-01-01

Yellow plaques seen during coronary angioscopy are thought to be the surrogates for superficial intimal lipids in coronary plaque. Given diffuse and heterogeneous nature of atherosclerosis, yellow plaques in coronaries may be seen as several yellow spots on diffuse coronary plaque. We examined the topographic association of yellow plaques with coronary plaque. In 40 non-severely stenotic ex-vivo coronary segments (average length: 52.2 +/- 3.1 mm), yellow plaques were examined by angioscopy with quantitative colorimetry. The segments were cut perpendicular to the long axis of the vessel at 2 mm intervals, and 1045 slides with 5 microm thick tissue for whole segments were prepared. To construct the plaque surface, each tissue slice was considered to be representative of the adjacent 2 mm. The circumference of the lumen and the lumen border of plaque were measured in each slide, and the plaque surface region was constructed. Coronary plaque was in 37 (93%) of 40 segments, and consisted of a single mass [39.9 +/- 3.9 (0-100) mm, 311.3 +/- 47.4 (0.0-1336.2) mm2]. In 30 (75%) segments, multiple (2-9) yellow plaques were detected on a mass of coronary plaque. The number of yellow plaques correlated positively with coronary plaque surface area (r = 0.77, P colorimetry, some of them are associated with lipid cores underneath thin fibrous caps, may be used to assess the extent of coronary plaque. Further research using angioscopy could be of value to study the association of high-risk coronaries with acute coronary syndromes.

Outcome of coronary plaque burden: a 10-year follow-up of aggressive medical management

OpenAIRE

Achenbach Stephan; Rumberger John A; Mohlenkamp Stefan; Lau Chu-Pak; Goh Victor K; Budoff Matthew J

2010-01-01

Abstract Background The effect of aggressive medical therapy on quantitative coronary plaque burden is not generally known, especially in ethnic Chinese. Aims We reasoned that Cardiac CT could conveniently quantify early coronary atherosclerosis in our patient population, and hypothesized that serial observation could differentiate the efficacy of aggressive medical therapy regarding progression and regression of the atherosclerotic process, as well as evaluating the additional impact of life...

Atherosclerotic plaque component segmentation in combined carotid MRI and CTA data incorporating class label uncertainty

DEFF Research Database (Denmark)

van Engelen, Arna; Niessen, Wiro J.; Klein, Stefan

2014-01-01

Atherosclerotic plaque composition can indicate plaque vulnerability. We segment atherosclerotic plaque components from the carotid artery on a combination of in vivo MRI and CT-angiography (CTA) data using supervised voxelwise classification. In contrast to previous studies the ground truth...... for training is directly obtained from 3D registration with histology for fibrous and lipid-rich necrotic tissue, and with [Formula: see text]CT for calcification. This registration does, however, not provide accurate voxelwise correspondence. We therefore evaluate three approaches that incorporate uncertainty......), II) samples are weighted by the local contour distance of the lumen and outer wall between histology and in vivo data, and III) 10% of each class is rejected by Gaussian outlier rejection. Classification was evaluated on the relative volumes (% of tissue type in the vessel wall) for calcified...

Progranulin gene delivery reduces plaque burden and synaptic atrophy in a mouse model of Alzheimer's disease.

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Jackalina M Van Kampen

Full Text Available Progranulin (PGRN is a multifunctional protein that is widely expressed throughout the brain, where it has been shown to act as a critical regulator of CNS inflammation and also functions as an autocrine neuronal growth factor, important for long-term neuronal survival. PGRN has been shown to activate cell signaling pathways regulating excitoxicity, oxidative stress, and synaptogenesis, as well as amyloidogenesis. Together, these critical roles in the CNS suggest that PGRN has the potential to be an important therapeutic target for the treatment of various neurodegenerative disorders, particularly Alzheimer's disease (AD. AD is the leading cause of dementia and is marked by the appearance of extracellular plaques consisting of aggregates of amyloid-β (Aβ, as well as neuroinflammation, oxidative stress, neuronal loss and synaptic atrophy. The ability of PGRN to target multiple key features of AD pathophysiology suggests that enhancing its expression may benefit this disease. Here, we describe the application of PGRN gene transfer using in vivo delivery of lentiviral expression vectors in a transgenic mouse model of AD. Viral vector delivery of the PGRN gene effectively enhanced PGRN expression in the hippocampus of Tg2576 mice. This elevated PGRN expression significantly reduced amyloid plaque burden in these mice, accompanied by reductions in markers of inflammation and synaptic atrophy. The overexpression of PGRN was also found to increase activity of neprilysin, a key amyloid beta degrading enzyme. PGRN regulation of neprilysin activity could play a major role in the observed alterations in plaque burden. Thus, PGRN may be an effective therapeutic target for the treatment of AD.

Tumor segmentation of whole-body magnetic resonance imaging in neurofibromatosis type 1 patients: tumor burden correlates

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Heffler, Michael A.; Xi, Yin; Chhabra, Avneesh [University of Texas Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Le, Lu Q. [University of Texas Southwestern Medical Center, Department of Dermatology, Dallas, TX (United States)

2017-01-15

Segmentation of whole-body MRI (WBMRI) to assess the feasibility, quantitate the total tumor volume (tumor burden) in patients with neurofibromatosis type 1 (NF1) and examine associations with demographic, disease-related and anthropomorphic features. A consecutive series of patients with NF1 underwent WBMRI and were reviewed for tumors. Tumors were segmented using a semiautomated software-based tool. Tumors were classified as superficial or deep and discrete or plexiform. Segmentation times were recorded. Segmentation yielded the quantity and tumor burden of superficial, internal and plexiform tumors. Correlations between segmentation data and demographic, disease-related and anthropomorphic features were examined. Fifteen patients were evaluated (42.3 ± 13.6 years, 10 female, 5 male). Segmentation times were a median of 30 min and yielded 2,328 tumors (1,582 superficial, 746 internal and 23 plexiform). One tumor was malignant. Tumor counts ranged from 14 to 397. Tumor burden ranged from 6.95 cm3 to 571 cm3. Individual tumor volume ranged from 0.0120 cm3 to 298 cm3. Significant correlation was found between the total volume of superficial tumors and height (ρ = 0.5966, p < 0.02). Male patients had higher overall tumor burdens (p < 0.05) and higher superficial tumor burden (p < 0.03). Patients with negative family history had more tumors (p < 0.05). Segmentation of WBMRI in patients with NF1 is feasible and elucidates meaningful relationships among disease phenotype, anthropomorphic and demographic features. (orig.)

Tumor segmentation of whole-body magnetic resonance imaging in neurofibromatosis type 1 patients: tumor burden correlates

International Nuclear Information System (INIS)

Heffler, Michael A.; Xi, Yin; Chhabra, Avneesh; Le, Lu Q.

2017-01-01

Segmentation of whole-body MRI (WBMRI) to assess the feasibility, quantitate the total tumor volume (tumor burden) in patients with neurofibromatosis type 1 (NF1) and examine associations with demographic, disease-related and anthropomorphic features. A consecutive series of patients with NF1 underwent WBMRI and were reviewed for tumors. Tumors were segmented using a semiautomated software-based tool. Tumors were classified as superficial or deep and discrete or plexiform. Segmentation times were recorded. Segmentation yielded the quantity and tumor burden of superficial, internal and plexiform tumors. Correlations between segmentation data and demographic, disease-related and anthropomorphic features were examined. Fifteen patients were evaluated (42.3 ± 13.6 years, 10 female, 5 male). Segmentation times were a median of 30 min and yielded 2,328 tumors (1,582 superficial, 746 internal and 23 plexiform). One tumor was malignant. Tumor counts ranged from 14 to 397. Tumor burden ranged from 6.95 cm3 to 571 cm3. Individual tumor volume ranged from 0.0120 cm3 to 298 cm3. Significant correlation was found between the total volume of superficial tumors and height (ρ = 0.5966, p < 0.02). Male patients had higher overall tumor burdens (p < 0.05) and higher superficial tumor burden (p < 0.03). Patients with negative family history had more tumors (p < 0.05). Segmentation of WBMRI in patients with NF1 is feasible and elucidates meaningful relationships among disease phenotype, anthropomorphic and demographic features. (orig.)

Differences in atherosclerotic plaque burden and morphology between type 1 and 2 diabetes as assessed by multislice computed tomography

NARCIS (Netherlands)

Djaberi, Roxana; Schuijf, Joanne D.; Boersma, Eric; Kroft, Lucia J. M.; Pereira, Alberto M.; Romijn, Johannes A.; Scholte, Arthur J.; Jukema, J. Wouter; Bax, Jeroen J.

2009-01-01

OBJECTIVE It is unclear whether the coronary atherosclerotic plaque burden is similar in patients with type 1 and type 2 diabetes. By using multislice computed tomography (MSCT), the presence, degree, and morphology of coronary artery disease (CAD) in patients with type 1 and type 2 diabetes were

Mediterranean Diet Score: Associations with Metabolic Products of the Intestinal Microbiome, Carotid Plaque Burden, and Renal Function

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Michael Pignanelli

2018-06-01

Full Text Available Metabolic products of the intestinal microbiome such as trimethylamine N-oxide (TMAO that accumulate in renal failure (gut-derived uremic toxins, GDUTs affect atherosclerosis and increase cardiovascular risk. We hypothesized that patients on a Mediterranean diet and those consuming lower amounts of dietary precursors would have lower levels of GDUTs. Patients attending vascular prevention clinics completed a Harvard Food Frequency Questionnaire (FFQ and had plasma levels of TMAO, p-cresylsulfate, hippuric acid, indoxyl sulfate, p-cresyl glucuronide, phenyl acetyl glutamine, and phenyl sulfate measured by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Carotid plaque burden was measured by ultrasound; CKD-Epi equations were used to estimate the glomerular filtration rate. In total, 276 patients completed the study. Even moderate renal function significantly increased plasma GDUTs, which were significantly associated with higher carotid plaque burden. There was no significant difference in plasma levels of any GDUT associated with a Mediterranean diet score or with intake of dietary precursors. In omnivorous patients with vascular disease, the intake of dietary precursors of intestinal metabolites or adherence to a Mediterranean diet did not change plasma GDUT. Approaches other than diet, such as probiotics and repopulation of the intestinal microbiome, may be required to mitigate the adverse effects of GDUTs.

Association of traditional cardiovascular risk factors with coronary plaque sub-types assessed by 64-slice computed tomography angiography in a large cohort of asymptomatic subjects.

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Rivera, Juan J; Nasir, Khurram; Cox, Pedro R; Choi, Eue-Keun; Yoon, Yeonyee; Cho, Iksung; Chun, Eun-Ju; Choi, Sang-Il; Blumenthal, Roger S; Chang, Hyuk-Jae

2009-10-01

Although prior studies have shown that traditional cardiovascular (CV) risk factors are associated with the burden of coronary atherosclerosis, less is known about the relationship of risk factors with coronary plaque sub-types. Coronary computed tomography angiography (CCTA) allows an assessment of both, total disease burden and plaque characteristics. In this study, we investigate the relationship between traditional CV risk factors and the presence and extent of coronary plaque sub-types in a large group of asymptomatic individuals. The study population consisted of 1015 asymptomatic Korean subjects (53+/-10 years; 64% were males) free of known CV disease who underwent 64-slice CCTA as part of a health screening evaluation. We analyzed plaque characteristics on a per-segment basis according to the modified American Heart Association classification. Plaques in which calcified tissue occupied more than 50% of the plaque area were classified as calcified (CAP), NCAP). A total of 215 (21%) subjects had coronary plaque while 800 (79%) had no identifiable disease. Multivariate regression analysis demonstrated that increased age (per decade) and gender are the strongest predictors for the presence of any coronary plaque or the presence of at least one segment of CAP and MCAP (any plaque-age: OR 2.89; 95% CI 2.34, 3.56; male gender: OR 5.21; 95% CI 3.20, 8.49; CAP-age: OR 2.75; 95% CI 2.12, 3.58; male gender: 4.78; 95% CI 2.48, 9.23; MCAP-age: OR 2.62; 95% CI 2.02, 3.39; male gender: OR 4.15; 95% CI 2.17, 7.94). The strongest predictors for the presence of any NCAP were gender (OR 3.56; 95% CI 1.96-6.55) and diabetes mellitus (OR 2.87; 95% CI 1.63-5.08). When looking at the multivariate association between the presence of >/=2 coronary segments with a plaque sub-type and CV risk factors, male gender was the strongest predictor for CAP (OR 7.31; 95% CI 2.12, 25.20) and MCAP (OR 5.54; 95% CI 1.84, 16.68). Alternatively, smoking was the strongest predictor for the presence

Clinical outcome of nonculprit plaque ruptures in patients with acute coronary syndrome in the PROSPECT study.

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Xie, Yong; Mintz, Gary S; Yang, Junqing; Doi, Hiroshi; Iñiguez, Andrés; Dangas, George D; Serruys, Patrick W; McPherson, John A; Wennerblom, Bertil; Xu, Ke; Weisz, Giora; Stone, Gregg W; Maehara, Akiko

2014-04-01

The aim of this study was to report the frequency, patient and lesion-related characteristics, and outcomes of subclinical, nonculprit plaque ruptures in the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study. Plaque rupture and subsequent thrombosis is the most common cause of acute coronary syndrome (ACS). Secondary, subclinical, nonculprit plaque ruptures have been seen in both stable patients and patients with ACS; however, reports of the natural history of these secondary plaque ruptures are limited. After successful stenting in 697 patients with ACS, 3-vessel grayscale and intravascular ultrasound virtual histology (IVUS-VH) was performed in the proximal-mid segments of all 3 coronary arteries as part of a prospective multicenter study. Among 660 patients with complete IVUS data, 128 plaque ruptures were identified in 105 nonculprit lesions in 100 arteries from 93 patients (14.1%). Although the minimum lumen area (MLA) was similar, the plaque burden was significantly greater in nonculprit lesions with a plaque rupture compared with nonculprit lesions without a plaque rupture (66.0% [95% confidence interval: 64.5% to 67.4%] vs. 56.0% [95% confidence interval: 55.6% to 56.4%]; p PROSPECT]; NCT00180466). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Comparison of intravascular ultrasound and angiographic assessement of coronary reference segment size in patients with type 2 diabetes mellitus

DEFF Research Database (Denmark)

Jensen, Lisette Okkels; Thayssen, Per; Mintz, Gary S

2008-01-01

During percutaneous coronary intervention, the reference segment is assessed angiographically. This report described the discrepancy between angiographic and intravascular ultrasound (IVUS) assessment of reference segment size in patients with type 2 diabetes mellitus. Preintervention IVUS was used...... to study 62 de novo lesions in 41 patients with type 2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden...... was measured as plaque CSA/external elastic membrane (EEM) CSA. Using IVUS, the reference lumen diameter was 2.80 +/- 0.42 mm and the reference EEM diameter was 4.17 +/- 0.56 mm. The angiographic reference diameter was 2.63 +/- 0.36 mm. Mean difference between the IVUS EEM diameter and angiographic reference...

Chronic cladribine administration increases amyloid beta peptide generation and plaque burden in mice.

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Crystal D Hayes

Full Text Available The clinical uses of 2-chloro-2'-deoxyadenosine (2-CDA or cladribine which was initially prescribed to patients with hematological and lymphoid cancers is now extended to treat patients with multiple sclerosis (MS. Previous data has shown that 2-CDA has high affinity to the brain and readily passes through the blood brain barrier reaching CSF concentrations 25% of that found in plasma. However, whether long-term administration of 2-CDA can lead to any adverse effects in patients or animal models is not yet clearly known.Here we show that exposure of 2-CDA to CHO cells stably expressing wild-type APP751 increased generation and secretion of amyloid β peptide (Aβ in to the conditioned medium. Interestingly, increased Aβ levels were noticed even at non-toxic concentrations of 2-CDA. Remarkably, chronic treatment of APdE9 mice, a model of Alzheimer's disease with 2-CDA for 60 days increased amyloid plaque burden by more than 1-fold. Increased Aβ generation appears to result from increased turnover of APP as revealed by cycloheximide-chase experiments. Additionally, surface labeling of APP with biotin and immunoprecipitation of surface labeled proteins with anti-biotin antibody also indicated increased APP at the cell surface in 2-CDA treated cells compared to controls. Increased turnover of APP by 2-CDA in turn might be a consequence of decreased protein levels of PIN 1, which is known to regulate cis-trans isomerization and phosphorylation of APP. Most importantly, like many other oncology drugs, 2-CDA administration led to significant delay in acquiring a reward-based learning task in a T maze paradigm.Taken together, these data provide compelling evidence for the first time that chronic 2-CDA administration can increase amyloidogenic processing of APP leading to robustly increased plaque burden which may be responsible for the observed deficits in learning skills. Thus chronic treatment of mice with 2-CDA can have deleterious effects in vivo.

Imaging unstable plaque

International Nuclear Information System (INIS)

SRIRANJAN, Rouchelle S.; TARKIN, Jason M.; RUDD, James H.; EVANS, Nicholas R.; CHOWDHURY, Mohammed M.

2016-01-01

Recent advances in imaging technology have enabled us to utilise a range of diagnostic approaches to better characterise high-risk atherosclerotic plaque. The aim of this article is to review current and emerging techniques used to detect and quantify unstable plaque in the context of large and small arterial systems and will focus on both invasive and non-invasive imaging techniques. While the diagnosis of clinically relevant atherosclerosis still relies heavily on anatomical assessment of arterial luminal stenosis, evolving multimodal cross-sectional imaging techniques that encompass novel molecular probes can provide added information with regard to plaque composition and overall disease burden. Novel molecular probes currently being developed to track precursors of plaque rupture such as inflammation, micro-calcification, hypoxia and neoangiogenesis are likely to have translational applications beyond diagnostics and have the potential to play a part in quantifying early responses to therapeutic interventions and more accurate cardiovascular risk stratification.

Plaque Burden Influences Accurate Classification of Fibrous Cap Atheroma by In-Vivo Optical Coherence Tomography in a Porcine Model of Advanced Coronary Atherosclerosis

DEFF Research Database (Denmark)

Poulsen, Christian B; Pedrigi, Ryan M; Pareek, Nilesh

2018-01-01

AIMS: In-vivo validation of coronary optical coherence tomography (OCT) against histology and the effects of plaque burden (PB) on plaque classification remain unreported. We investigated this in a porcine model with human-like coronary atherosclerosis. METHODS AND RESULTS: Five female Yucatan D374...... a validated algorithm. Lesions were adjudicated using the Virmani classification and PB assessed from histology. OCT had a high sensitivity, but modest specificity (92.9% and 74.6%), for identifying fibrous cap atheroma (FCA). The reduced specificity for OCT was due to misclassification of plaques...... with histologically defined pathological intimal thickening (PIT) as FCA (46.1% of the frames with histological PIT were misclassified). PIT lesions misclassified as FCA by OCT had a statistically higher PB than in other OCT frames (median 32.0% versus 13.4%; p

Automated image segmentation and registration of vessel wall MRI for quantitative assessment of carotid artery vessel wall dimensions and plaque composition

NARCIS (Netherlands)

Klooster, Ronald van 't

2014-01-01

The main goal of this thesis was to develop methods for automated segmentation, registration and classification of the carotid artery vessel wall and plaque components using multi-sequence MR vessel wall images to assess atherosclerosis. First, a general introduction into atherosclerosis and

An objective method to optimize the MR sequence set for plaque classification in carotid vessel wall images using automated image segmentation.

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Ronald van 't Klooster

Full Text Available A typical MR imaging protocol to study the status of atherosclerosis in the carotid artery consists of the application of multiple MR sequences. Since scanner time is limited, a balance has to be reached between the duration of the applied MR protocol and the quantity and quality of the resulting images which are needed to assess the disease. In this study an objective method to optimize the MR sequence set for classification of soft plaque in vessel wall images of the carotid artery using automated image segmentation was developed. The automated method employs statistical pattern recognition techniques and was developed based on an extensive set of MR contrast weightings and corresponding manual segmentations of the vessel wall and soft plaque components, which were validated by histological sections. Evaluation of the results from nine contrast weightings showed the tradeoff between scan duration and automated image segmentation performance. For our dataset the best segmentation performance was achieved by selecting five contrast weightings. Similar performance was achieved with a set of three contrast weightings, which resulted in a reduction of scan time by more than 60%. The presented approach can help others to optimize MR imaging protocols by investigating the tradeoff between scan duration and automated image segmentation performance possibly leading to shorter scanning times and better image interpretation. This approach can potentially also be applied to other research fields focusing on different diseases and anatomical regions.

Endothelial dysfunction, carotid artery plaque burden, and conventional exercise-induced myocardial ischemia as predictors of coronary artery disease prognosis

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Ishihara Masayuki

2008-12-01

Full Text Available Abstract Background While both flow-mediated vasodilation (FMD in the brachial artery (BA, which measures endothelium-dependent vasodilatation, and intima-media thickness (IMT in the carotid artery are correlated with the prognosis of coronary artery disease (CAD, it is not clear which modality is a better predictor of CAD. Furthermore, it has not been fully determined whether either of these modalities is superior to conventional ST-segment depression on exercise stress electrocardiogram (ECG as a predictor. Thus, the goal of the present study was to compare the predictive value of FMD, IMT, and stress ECG for CAD prognosis. Methods and Results A total of 103 consecutive patients (62 ± 9 years old, 79 men with clinically suspected CAD had FMD and nitroglycerin-induced dilation (NTG-D in the BA, carotid artery IMT measurement using high-resolution ultrasound, and exercise treadmill testing. The 73 CAD patients and 30 normal coronary patients were followed for 50 ± 15 months. Fifteen patients had coronary events during this period (1 cardiac death, 2 non-fatal myocardial infarctions, 3 acute heart failures, and 9 unstable anginas. On Kaplan-Meier analysis, only FMD and stress ECG were significant predictors for cardiac events. Conclusion Brachial endothelial function as reflected by FMD and conventional exercise stress testing has comparable prognostic value, whereas carotid artery plaque burden appears to be less powerful for predicting future cardiac events.

Virtual histology study of atherosclerotic plaque composition in patients with stable angina and acute phase of acute coronary syndromes without ST segment elevation

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Ivanović Miloš

2013-01-01

Full Text Available Introduction. Rupture of vulnerable atherosclerotic plaques is the cause of most acute coronary syndromes (ACS. Postmortem studies which compared stable coronary lesions and atherosclerotic plaques in patients who have died because of ACS indicated high lipid-core content as one of the major determinants of plaque vulnerability. Objective. Our primary goal was to assess the potential relations of plaque composition determined by IVUS-VH (Intravascular Ultrasound - Virtual Histology in patients with stable angina and subjects in acute phase of ACS without ST segment elevation. Methods. The study comprised of 40 patients who underwent preintervention IVUS examination. Tissue maps were reconstructed from radio frequency data using IVUS-VH software. Results. We analyzed 53 lesions in 40 patients. Stable angina was diagnosed in 24 patients (29 lesions, while acute phase of ACS without ST elevation was diagnosed in 16 patients (24 lesions. In the patients in acute phase of ACS without ST segment elevation IVUS-VH examination showed a significantly larger area of the necrotic core at the site of minimal lumen area and a larger mean of the necrotic core volume in the entire lesion comparing to stable angina subjects (1.84±0.90 mm2 vs. 0.96±0.69 mm2; p<0.001 and 20.94±15.79 mm3 vs. 11.54±14.15 mm3; p<0.05 respectively. Conclusion. IVUS-VH detected that the necrotic core was significantly larger in atherosclerotic lesions in patients in acute phase of ACS without ST elevation comparing to the stable angina subjects and that it could be considered as a marker of plaque vulnerability.

Quantitative Comparison of Dense-Core Amyloid Plaque Accumulation in Amyloid-β Precursor Protein Transgenic Mice

Science.gov (United States)

Liu, Peng; Reichl, John H.; Rao, Eshaan R.; McNellis, Brittany M.; Huang, Eric S.; Hemmy, Laura S.; Forster, Colleen L.; Kuskowski, Michael A.; Borchelt, David R.; Vassar, Robert; Ashe, Karen H.; Zahs, Kathleen R.

2016-01-01

There exist several dozen lines of transgenic mice that express human amyloid-β precursor protein (AβPP) with Alzheimer’s disease (AD)-linked mutations. AβPP transgenic mouse lines differ in the types and amounts of Aβ that they generate and in their spatiotemporal patterns of expression of Aβ assemblies, providing a toolkit to study Aβ amyloidosis and the influence of Aβ aggregation on brain function. More complete quantitative descriptions of the types of Aβ assemblies present in transgenic mice and in humans during disease progression should add to our understanding of how Aβ toxicity in mice relates to the pathogenesis of AD. Here, we provide a direct quantitative comparison of amyloid plaque burdens and plaque sizes in four lines of AβPP transgenic mice. We measured the fraction of cortex and hippocampus occupied by dense-core plaques, visualized by staining with Thioflavin S, in mice from young adulthood through advanced age. We found that the plaque burdens among the transgenic lines varied by an order of magnitude: at 15 months of age, the oldest age studied, the median cortical plaque burden in 5XFAD mice was already ~4.5 times that of 21-month Tg2576 mice and ~15 times that of 21–24-month rTg9191 mice. Plaque-size distributions changed across the lifespan in a line- and region-dependent manner. We also compared the dense-core plaque burdens in the mice to those measured in a set of pathologically-confirmed AD cases from the Nun Study. Cortical plaque burdens in Tg2576, APPSwePS1ΔE9, and 5XFAD mice eventually far exceeded those measured in the human cohort. PMID:28059792

Quantitative Comparison of Dense-Core Amyloid Plaque Accumulation in Amyloid-β Protein Precursor Transgenic Mice.

Science.gov (United States)

Liu, Peng; Reichl, John H; Rao, Eshaan R; McNellis, Brittany M; Huang, Eric S; Hemmy, Laura S; Forster, Colleen L; Kuskowski, Michael A; Borchelt, David R; Vassar, Robert; Ashe, Karen H; Zahs, Kathleen R

2017-01-01

There exist several dozen lines of transgenic mice that express human amyloid-β protein precursor (AβPP) with Alzheimer's disease (AD)-linked mutations. AβPP transgenic mouse lines differ in the types and amounts of Aβ that they generate and in their spatiotemporal patterns of expression of Aβ assemblies, providing a toolkit to study Aβ amyloidosis and the influence of Aβ aggregation on brain function. More complete quantitative descriptions of the types of Aβ assemblies present in transgenic mice and in humans during disease progression should add to our understanding of how Aβ toxicity in mice relates to the pathogenesis of AD. Here, we provide a direct quantitative comparison of amyloid plaque burdens and plaque sizes in four lines of AβPP transgenic mice. We measured the fraction of cortex and hippocampus occupied by dense-core plaques, visualized by staining with Thioflavin S, in mice from young adulthood through advanced age. We found that the plaque burdens among the transgenic lines varied by an order of magnitude: at 15 months of age, the oldest age studied, the median cortical plaque burden in 5XFAD mice was already ∼4.5 times that of 21-month-old Tg2576 mice and ∼15 times that of 21-24-month-old rTg9191 mice. Plaque-size distributions changed across the lifespan in a line- and region-dependent manner. We also compared the dense-core plaque burdens in the mice to those measured in a set of pathologically-confirmed AD cases from the Nun Study. Cortical plaque burdens in Tg2576, APPSwePS1ΔE9, and 5XFAD mice eventually far exceeded those measured in the human cohort.

Influence of Adaptive Statistical Iterative Reconstruction on coronary plaque analysis in coronary computed tomography angiography

DEFF Research Database (Denmark)

Precht, Helle; Kitslaar, Pieter H; Broersen, Alexander

2016-01-01

performed. Images were reconstructed using FBP, 30% and 60% adaptive statistical IR (ASIR). Coronary plaque analysis was performed as per patient and per vessel (LM, LAD, CX and RCA) measurements. Lumen and vessel volumes and plaque burden measurements were based on automatic detected contours in each...... reconstruction. Lumen and plaque intensity measurements and HU based plaque characterization were based on corrected contours copied to each reconstruction. RESULTS: No significant changes between FBP and 30% ASIR were found except for lumen- (-2.53 HU) and plaque intensities (-1.28 HU). Between FBP and 60% ASIR...... the change in total volume showed an increase of 0.94%, 4.36% and 2.01% for lumen, plaque and vessel, respectively. The change in total plaque burden between FBP and 60% ASIR was 0.76%. Lumen and plaque intensities decreased between FBP and 60% ASIR with -9.90 HU and -1.97 HU, respectively. The total plaque...

First experiences with model based iterative reconstructions influence on quantitative plaque volume and intensity measurements in coronary computed tomography angiography

International Nuclear Information System (INIS)

Precht, H.; Kitslaar, P.H.; Broersen, A.; Gerke, O.; Dijkstra, J.; Thygesen, J.; Egstrup, K.; Lambrechtsen, J.

2017-01-01

Purpose: Investigate the influence of adaptive statistical iterative reconstruction (ASIR) and the model-based IR (Veo) reconstruction algorithm in coronary computed tomography angiography (CCTA) images on quantitative measurements in coronary arteries for plaque volumes and intensities. Methods: Three patients had three independent dose reduced CCTA performed and reconstructed with 30% ASIR (CTDI vol at 6.7 mGy), 60% ASIR (CTDI vol 4.3 mGy) and Veo (CTDI vol at 1.9 mGy). Coronary plaque analysis was performed for each measured CCTA volumes, plaque burden and intensities. Results: Plaque volume and plaque burden show a decreasing tendency from ASIR to Veo as median volume for ASIR is 314 mm 3 and 337 mm 3 –252 mm 3 for Veo and plaque burden is 42% and 44% for ASIR to 39% for Veo. The lumen and vessel volume decrease slightly from 30% ASIR to 60% ASIR with 498 mm 3 –391 mm 3 for lumen volume and vessel volume from 939 mm 3 to 830 mm 3 . The intensities did not change overall between the different reconstructions for either lumen or plaque. Conclusion: We found a tendency of decreasing plaque volumes and plaque burden but no change in intensities with the use of low dose Veo CCTA (1.9 mGy) compared to dose reduced ASIR CCTA (6.7 mGy & 4.3 mGy), although more studies are warranted. - Highlights: • Veo decrease plaque volumes and plaque burden using low-dose CCTA. • Moving from ASIR 30%, ASIR 60% to Veo did not appear to influence the plaque intensities. • Studies including larger sample size are needed to investigate the effect on plaque.

HDL mimetic CER-001 targets atherosclerotic plaques in patients.

Science.gov (United States)

Zheng, Kang He; van der Valk, Fleur M; Smits, Loek P; Sandberg, Mara; Dasseux, Jean-Louis; Baron, Rudi; Barbaras, Ronald; Keyserling, Constance; Coolen, Bram F; Nederveen, Aart J; Verberne, Hein J; Nell, Thijs E; Vugts, Danielle J; Duivenvoorden, Raphaël; Fayad, Zahi A; Mulder, Willem J M; van Dongen, Guus A M S; Stroes, Erik S G

2016-08-01

Infusion of high-density lipoprotein (HDL) mimetics aimed at reducing atherosclerotic burden has led to equivocal results, which may relate in part to the inability of HDL mimetics to adequately reach atherosclerotic lesions in humans. This study evaluated delivery of recombinant human apolipoprotein A-I (apoA-I) containing HDL mimetic CER-001 in carotid plaques in patients. CER-001 was radiolabeled with the long-lived positron emitter zirconium-89 ((89)Zr) to enable positron emission tomography with computed tomography (PET/CT) imaging. Eight patients with atherosclerotic carotid artery disease (>50% stenosis) received a single infusion of unlabeled CER-001 (3 mg/kg), co-administered with 10 mg of (89)Zr-labeled CER-001 (18 MBq). Serial PET/CT imaging and contrast enhanced-magnetic resonance imaging (CE-MRI) were performed to evaluate targeted delivery of CER-001. One hour after infusion, mean plasma apoA-I levels increased by 9.9 mg/dL (p = 0.026), with a concomitant relative increase in the plasma cholesterol efflux capacity of 13.8% (p CER-001 expressed as target-to-background ratio (TBRmax) increased significantly 24 h after infusion, and remained increased up to 48 h (TBRmax t = 10 min: 0.98; t = 24 h: 1.14 (p = 0.001); t = 48 h: 1.12 (p = 0.007)). TBRmax was higher in plaque compared with non-plaque segments (1.18 vs. 1.05; p CER-001 increases plasma apoA-I concentration and plasma cholesterol efflux capacity. Our data support the concept that CER-001 targets plaque regions in patients, which correlates with plaque contrast enhancement. These clinical findings may also guide future nanomedicine development using HDL particles for drug delivery in atherosclerosis. Netherlands Trial Registry - NTR5178. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5178. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Normalized wall index specific and MRI-based stress analysis of atherosclerotic carotid plaques. A study comparing acutely symptomatic and asymptomatic patients

International Nuclear Information System (INIS)

Zhu, C.; Teng, Z.; Sadat, U.; Young, V.E.; Graves, M.J.; Gillard, J.H.; Li Zhiyong

2010-01-01

Biomechanical stresses play an important role in determining plaque stability. Quantification of these simulated stresses can be potentially used to assess plaque vulnerability and differentiate different patient groups. 54 asymptomatic and 45 acutely symptomatic patients underwent in vivo multicontrast magnetic resonance imaging (MRI) of the carotid arteries. Plaque geometry used for finite element analysis was derived from in vivo MRI at the sites of maximum and minimum plaque burden. In total, 198 slices were used for the computational simulations. A pre-shrink technique was used to refine the simulation. Maximum principle stress at the vulnerable plaque sites (id est (ie), critical stress) was extracted for the selected slices and a comparison was performed between the 2 groups. Critical stress in the slice with maximum plaque burden is significantly higher in acutely symptomatic patients as compared to asymptomatic patients (median, inter quartile range: 198.0 kPa (119.8-359.0 kPa) vs 138.4 kPa (83.8-242.6 kPa), P=0.04). No significant difference was found in the slice with minimum plaque burden between the 2 groups (196.7 kPa (133.3-282.7 kPa) vs 182.4 kPa (117.2-310.6 kPa), P=0.82). Acutely symptomatic carotid plaques have significantly high biomechanical stresses than asymptomatic plaques. This might be potentially useful for establishing a biomechanical risk stratification criteria based on plaque burden in future studies. (author)

Fractal analysis of plaque border, a novel method for the quantification of atherosclerotic plaque contour irregularity, is associated with pro-atherogenic plasma lipid profile in subjects with non-obstructive carotid stenoses.

Science.gov (United States)

Moroni, Francesco; Magnoni, Marco; Vergani, Vittoria; Ammirati, Enrico; Camici, Paolo G

2018-01-01

Plaque border irregularity is a known imaging characteristic of vulnerable plaques, but its evaluation heavily relies on subjective evaluation and operator expertise. Aim of the present work is to propose a novel fractal-analysis based method for the quantification of atherosclerotic plaque border irregularity and assess its relation with cardiovascular risk factors. Forty-two asymptomatic subjects with carotid stenosis underwent ultrasound evaluation and assessment of cardiovascular risk factors. Total, low-density lipoprotein (LDL), high-density lipoprotein (HDL) plasma cholesterol and triglycerides concentrations were measured for each subject. Fractal analysis was performed in all the carotid segments affected by atherosclerosis, i.e. 147 segments. The resulting fractal dimension (FD) is a measure of irregularity of plaque profile on long axis view of the plaque. FD in the severest stenosis (main plaque FD,mFD) was 1.136±0.039. Average FD per patient (global FD,gFD) was 1.145±0.039. FD was independent of other plaque characteristics. mFD significantly correlated with plasma HDL (r = -0.367,p = 0.02) and triglycerides-to-HDL ratio (r = 0.480,p = 0.002). Fractal analysis is a novel, readily available, reproducible and inexpensive technique for the quantitative measurement of plaque irregularity. The correlation between low HDL levels and plaque FD suggests a role for HDL in the acquisition of morphologic features of plaque instability. Further studies are needed to validate the prognostic value of fractal analysis in carotid plaques evaluation.

Plaque Structural Stress Estimations Improve Prediction of Future Major Adverse Cardiovascular Events After Intracoronary Imaging.

Science.gov (United States)

Brown, Adam J; Teng, Zhongzhao; Calvert, Patrick A; Rajani, Nikil K; Hennessy, Orla; Nerlekar, Nitesh; Obaid, Daniel R; Costopoulos, Charis; Huang, Yuan; Hoole, Stephen P; Goddard, Martin; West, Nick E J; Gillard, Jonathan H; Bennett, Martin R

2016-06-01

Although plaque rupture is responsible for most myocardial infarctions, few high-risk plaques identified by intracoronary imaging actually result in future major adverse cardiovascular events (MACE). Nonimaging markers of individual plaque behavior are therefore required. Rupture occurs when plaque structural stress (PSS) exceeds material strength. We therefore assessed whether PSS could predict future MACE in high-risk nonculprit lesions identified on virtual-histology intravascular ultrasound. Baseline nonculprit lesion features associated with MACE during long-term follow-up (median: 1115 days) were determined in 170 patients undergoing 3-vessel virtual-histology intravascular ultrasound. MACE was associated with plaque burden ≥70% (hazard ratio: 8.6; 95% confidence interval, 2.5-30.6; P<0.001) and minimal luminal area ≤4 mm(2) (hazard ratio: 6.6; 95% confidence interval, 2.1-20.1; P=0.036), although absolute event rates for high-risk lesions remained <10%. PSS derived from virtual-histology intravascular ultrasound was subsequently estimated in nonculprit lesions responsible for MACE (n=22) versus matched control lesions (n=22). PSS showed marked heterogeneity across and between similar lesions but was significantly increased in MACE lesions at high-risk regions, including plaque burden ≥70% (13.9±11.5 versus 10.2±4.7; P<0.001) and thin-cap fibroatheroma (14.0±8.9 versus 11.6±4.5; P=0.02). Furthermore, PSS improved the ability of virtual-histology intravascular ultrasound to predict MACE in plaques with plaque burden ≥70% (adjusted log-rank, P=0.003) and minimal luminal area ≤4 mm(2) (P=0.002). Plaques responsible for MACE had larger superficial calcium inclusions, which acted to increase PSS (P<0.05). Baseline PSS is increased in plaques responsible for MACE and improves the ability of intracoronary imaging to predict events. Biomechanical modeling may complement plaque imaging for risk stratification of coronary nonculprit lesions. © 2016

Influence of Adaptive Statistical Iterative Reconstruction on coronary plaque analysis in coronary computed tomography angiography.

Science.gov (United States)

Precht, Helle; Kitslaar, Pieter H; Broersen, Alexander; Dijkstra, Jouke; Gerke, Oke; Thygesen, Jesper; Egstrup, Kenneth; Lambrechtsen, Jess

The purpose of this study was to study the effect of iterative reconstruction (IR) software on quantitative plaque measurements in coronary computed tomography angiography (CCTA). Thirty patients with a three clinical risk factors for coronary artery disease (CAD) had one CCTA performed. Images were reconstructed using FBP, 30% and 60% adaptive statistical IR (ASIR). Coronary plaque analysis was performed as per patient and per vessel (LM, LAD, CX and RCA) measurements. Lumen and vessel volumes and plaque burden measurements were based on automatic detected contours in each reconstruction. Lumen and plaque intensity measurements and HU based plaque characterization were based on corrected contours copied to each reconstruction. No significant changes between FBP and 30% ASIR were found except for lumen- (-2.53 HU) and plaque intensities (-1.28 HU). Between FBP and 60% ASIR the change in total volume showed an increase of 0.94%, 4.36% and 2.01% for lumen, plaque and vessel, respectively. The change in total plaque burden between FBP and 60% ASIR was 0.76%. Lumen and plaque intensities decreased between FBP and 60% ASIR with -9.90 HU and -1.97 HU, respectively. The total plaque component volume changes were all small with a maximum change of -1.13% of necrotic core between FBP and 60% ASIR. Quantitative plaque measurements only showed modest differences between FBP and the 60% ASIR level. Differences were increased lumen-, vessel- and plaque volumes, decreased lumen- and plaque intensities and a small percentage change in the individual plaque component volumes. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Joint segmentation of lumen and outer wall from femoral artery MR images: Towards 3D imaging measurements of peripheral arterial disease.

Science.gov (United States)

Ukwatta, Eranga; Yuan, Jing; Qiu, Wu; Rajchl, Martin; Chiu, Bernard; Fenster, Aaron

2015-12-01

Three-dimensional (3D) measurements of peripheral arterial disease (PAD) plaque burden extracted from fast black-blood magnetic resonance (MR) images have shown to be more predictive of clinical outcomes than PAD stenosis measurements. To this end, accurate segmentation of the femoral artery lumen and outer wall is required for generating volumetric measurements of PAD plaque burden. Here, we propose a semi-automated algorithm to jointly segment the femoral artery lumen and outer wall surfaces from 3D black-blood MR images, which are reoriented and reconstructed along the medial axis of the femoral artery to obtain improved spatial coherence between slices of the long, thin femoral artery and to reduce computation time. The developed segmentation algorithm enforces two priors in a global optimization manner: the spatial consistency between the adjacent 2D slices and the anatomical region order between the femoral artery lumen and outer wall surfaces. The formulated combinatorial optimization problem for segmentation is solved globally and exactly by means of convex relaxation using a coupled continuous max-flow (CCMF) model, which is a dual formulation to the convex relaxed optimization problem. In addition, the CCMF model directly derives an efficient duality-based algorithm based on the modern multiplier augmented optimization scheme, which has been implemented on a GPU for fast computation. The computed segmentations from the developed algorithm were compared to manual delineations from experts using 20 black-blood MR images. The developed algorithm yielded both high accuracy (Dice similarity coefficients ≥ 87% for both the lumen and outer wall surfaces) and high reproducibility (intra-class correlation coefficient of 0.95 for generating vessel wall area), while outperforming the state-of-the-art method in terms of computational time by a factor of ≈ 20. Copyright © 2015 Elsevier B.V. All rights reserved.

[Evaluation of dental plaque by quantitative digital image analysis system].

Science.gov (United States)

Huang, Z; Luan, Q X

2016-04-18

To analyze the plaque staining image by using image analysis software, to verify the maneuverability, practicability and repeatability of this technique, and to evaluate the influence of different plaque stains. In the study, 30 volunteers were enrolled from the new dental students of Peking University Health Science Center in accordance with the inclusion criteria. The digital images of the anterior teeth were acquired after plaque stained according to filming standardization.The image analysis was performed using Image Pro Plus 7.0, and the Quigley-Hein plaque indexes of the anterior teeth were evaluated. The plaque stain area percentage and the corresponding dental plaque index were highly correlated,and the Spearman correlation coefficient was 0.776 (Pchart showed only a few spots outside the 95% consistency boundaries. The different plaque stains image analysis results showed that the difference of the tooth area measurements was not significant, while the difference of the plaque area measurements significant (P<0.01). This method is easy in operation and control,highly related to the calculated percentage of plaque area and traditional plaque index, and has good reproducibility.The different plaque staining method has little effect on image segmentation results.The sensitive plaque stain for image analysis is suggested.

Comparison of traditional cardiovascular risk models and coronary atherosclerotic plaque as detected by computed tomography for prediction of acute coronary syndrome in patients with acute chest pain.

Science.gov (United States)

Ferencik, Maros; Schlett, Christopher L; Bamberg, Fabian; Truong, Quynh A; Nichols, John H; Pena, Antonio J; Shapiro, Michael D; Rogers, Ian S; Seneviratne, Sujith; Parry, Blair Alden; Cury, Ricardo C; Brady, Thomas J; Brown, David F; Nagurney, John T; Hoffmann, Udo

2012-08-01

The objective was to determine the association of four clinical risk scores and coronary plaque burden as detected by computed tomography (CT) with the outcome of acute coronary syndrome (ACS) in patients with acute chest pain. The hypothesis was that the combination of risk scores and plaque burden improved the discriminatory capacity for the diagnosis of ACS. The study was a subanalysis of the Rule Out Myocardial Infarction Using Computer-Assisted Tomography (ROMICAT) trial-a prospective observational cohort study. The authors enrolled patients presenting to the emergency department (ED) with a chief complaint of acute chest pain, inconclusive initial evaluation (negative biomarkers, nondiagnostic electrocardiogram [ECG]), and no history of coronary artery disease (CAD). Patients underwent contrast-enhanced 64-multidetector-row cardiac CT and received standard clinical care (serial ECG, cardiac biomarkers, and subsequent diagnostic testing, such as exercise treadmill testing, nuclear stress perfusion imaging, and/or invasive coronary angiography), as deemed clinically appropriate. The clinical providers were blinded to CT results. The chest pain score was calculated and the results were dichotomized to ≥10 (high-risk) and modeling was performed to examine the association of risk scores and coronary plaque burden to the outcome of ACS. Unadjusted models were individually fitted for the coronary plaque burden and for Goldman, Sanchis, TIMI, and chest pain scores. In adjusted analyses, the authors tested whether the association between risk scores and ACS persisted after controlling for the coronary plaque burden. The prognostic discriminatory capacity of the risk scores and plaque burden for ACS was assessed using c-statistics. The differences in area under the receiver-operating characteristic curve (AUC) and c-statistics were tested by performing the -2 log likelihood ratio test of nested models. A p value capacity for the diagnosis of ACS. Plaque burden was

Characterisation of carotid plaques with ultrasound elastography: feasibility and correlation with high-resolution magnetic resonance imaging

International Nuclear Information System (INIS)

Naim, Cyrille; Cloutier, Guy; Mercure, Elizabeth; Destrempes, Francois; Qin, Zhao; El-Abyad, Walid; Lanthier, Sylvain; Giroux, Marie-France; Soulez, Gilles

2013-01-01

To evaluate the ability of ultrasound non-invasive vascular elastography (NIVE) strain analysis to characterise carotid plaque composition and vulnerability as determined by high-resolution magnetic resonance imaging (MRI). Thirty-one subjects with 50 % or greater carotid stenosis underwent NIVE and high-resolution MRI of internal carotid arteries. Time-varying strain images (elastograms) of segmented plaques were generated from ultrasonic raw radiofrequency sequences. On MRI, corresponding plaques and components were segmented and quantified. Associations between strain parameters, plaque composition and symptomatology were estimated with curve-fitting regressions and Mann-Whitney tests. Mean stenosis and age were 72.7 % and 69.3 years, respectively. Of 31 plaques, 9 were symptomatic, 17 contained lipid and 7 were vulnerable on MRI. Strains were significantly lower in plaques containing a lipid core compared with those without lipid, with 77-100 % sensitivity and 57-79 % specificity (P < 0.032). A statistically significant quadratic fit was found between strain and lipid content (P < 0.03). Strains did not discriminate symptomatic patients or vulnerable plaques. Ultrasound NIVE is feasible in patients with significant carotid stenosis and can detect the presence of a lipid core with high sensitivity and moderate specificity. Studies of plaque progression with NIVE are required to identify vulnerable plaques. (orig.)

Coronary artery plaque burden and calcium scores in healthy men adhering to long-term wine drinking or alcohol abstinence

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Luz, P.L. da; Coimbra, S.; Favarato, D.; Albuquerque, C. [Divisão de Cardiologia Clínica, Instituto do Coração (Incor), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Mochiduky, R.I.; Rochitte, C.E. [Divisão de Radiologia, Instituto do Coração (Incor), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Hojaij, E. [Serviço de Psicologia, Instituto do Coração (Incor), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Gonsalves, C.R.L. [Serviço Nutricional, Instituto do Coração (Incor), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Laurindo, F.R. [Laboratório de Biologia Vascular, Instituto do Coração (Incor), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

2014-07-04

Observational studies suggest there are clinical benefits to moderate red wine (RW) consumption. However, the effects on coronary vasculature and overall lifestyle are unclear. We investigated whether a lifestyle of regular long-term RW consumption is associated with changes in coronary plaque burden, calcium score, carotid intima/media thickness, endothelial function, and metabolic variables, compared with alcohol abstinence. Healthy volunteers were evaluated by coronary computed tomography angiography (CTA) as well as carotid and brachial artery ultrasound. Nutritional status, psychological status, and metabolic variables were assessed. The study included 101 drinkers [aged 58.9±7.3 years (means±SD)], from wine brotherhoods, and 104 abstainers, from Anglican, Evangelical and Catholic churches both in the city of São Paulo, Brazil. No significant differences in demographics were noted. Lesion prevalence per patient assessed by coronary CTA and classified as absent (0), 1-25, 26-49, and ≥50% stenosis was similar between groups. When analyzed by individual arteries, i.e., left anterior descending, circumflex, and right coronary, prevalence was also not different. On the other hand, calcium scores were higher among drinkers than abstainers (144.4±362.2 vs 122.0±370.3; P<0.01). However, drinkers reported less history of diabetes and exercised more. RW drinkers consumed 2127.9±387.7 kcal/day while abstainers consumed 1836.0±305.0 (P<0.0001). HDL cholesterol was significantly higher among drinkers compared to abstainers (46.9±10.9 vs 39.5±9.0 mg/dL; P<0.001), while fasting plasma glucose was lower (97.6±18.2 vs 118.4±29.6 mg/dL; P<0.02). Liver enzymes were normal in both groups. In conclusion, long-term wine drinkers displayed a similar plaque burden but greater calcium score than abstainers, despite a more atherogenic diet, and the mechanisms for the increased calcium scores in the former remain speculative.

Coronary artery plaque burden and calcium scores in healthy men adhering to long-term wine drinking or alcohol abstinence

International Nuclear Information System (INIS)

Luz, P.L. da; Coimbra, S.; Favarato, D.; Albuquerque, C.; Mochiduky, R.I.; Rochitte, C.E.; Hojaij, E.; Gonsalves, C.R.L.; Laurindo, F.R.

2014-01-01

Observational studies suggest there are clinical benefits to moderate red wine (RW) consumption. However, the effects on coronary vasculature and overall lifestyle are unclear. We investigated whether a lifestyle of regular long-term RW consumption is associated with changes in coronary plaque burden, calcium score, carotid intima/media thickness, endothelial function, and metabolic variables, compared with alcohol abstinence. Healthy volunteers were evaluated by coronary computed tomography angiography (CTA) as well as carotid and brachial artery ultrasound. Nutritional status, psychological status, and metabolic variables were assessed. The study included 101 drinkers [aged 58.9±7.3 years (means±SD)], from wine brotherhoods, and 104 abstainers, from Anglican, Evangelical and Catholic churches both in the city of São Paulo, Brazil. No significant differences in demographics were noted. Lesion prevalence per patient assessed by coronary CTA and classified as absent (0), 1-25, 26-49, and ≥50% stenosis was similar between groups. When analyzed by individual arteries, i.e., left anterior descending, circumflex, and right coronary, prevalence was also not different. On the other hand, calcium scores were higher among drinkers than abstainers (144.4±362.2 vs 122.0±370.3; P<0.01). However, drinkers reported less history of diabetes and exercised more. RW drinkers consumed 2127.9±387.7 kcal/day while abstainers consumed 1836.0±305.0 (P<0.0001). HDL cholesterol was significantly higher among drinkers compared to abstainers (46.9±10.9 vs 39.5±9.0 mg/dL; P<0.001), while fasting plasma glucose was lower (97.6±18.2 vs 118.4±29.6 mg/dL; P<0.02). Liver enzymes were normal in both groups. In conclusion, long-term wine drinkers displayed a similar plaque burden but greater calcium score than abstainers, despite a more atherogenic diet, and the mechanisms for the increased calcium scores in the former remain speculative

Coronary artery plaque burden and calcium scores in healthy men adhering to long-term wine drinking or alcohol abstinence

Directory of Open Access Journals (Sweden)

P.L. da Luz

2014-08-01

Full Text Available Observational studies suggest there are clinical benefits to moderate red wine (RW consumption. However, the effects on coronary vasculature and overall lifestyle are unclear. We investigated whether a lifestyle of regular long-term RW consumption is associated with changes in coronary plaque burden, calcium score, carotid intima/media thickness, endothelial function, and metabolic variables, compared with alcohol abstinence. Healthy volunteers were evaluated by coronary computed tomography angiography (CTA as well as carotid and brachial artery ultrasound. Nutritional status, psychological status, and metabolic variables were assessed. The study included 101 drinkers [aged 58.9±7.3 years (means±SD], from wine brotherhoods, and 104 abstainers, from Anglican, Evangelical and Catholic churches both in the city of São Paulo, Brazil. No significant differences in demographics were noted. Lesion prevalence per patient assessed by coronary CTA and classified as absent (0, 1-25, 26-49, and ≥50% stenosis was similar between groups. When analyzed by individual arteries, i.e., left anterior descending, circumflex, and right coronary, prevalence was also not different. On the other hand, calcium scores were higher among drinkers than abstainers (144.4±362.2 vs 122.0±370.3; P<0.01. However, drinkers reported less history of diabetes and exercised more. RW drinkers consumed 2127.9±387.7 kcal/day while abstainers consumed 1836.0±305.0 (P<0.0001. HDL cholesterol was significantly higher among drinkers compared to abstainers (46.9±10.9 vs 39.5±9.0 mg/dL; P<0.001, while fasting plasma glucose was lower (97.6±18.2 vs 118.4±29.6 mg/dL; P<0.02. Liver enzymes were normal in both groups. In conclusion, long-term wine drinkers displayed a similar plaque burden but greater calcium score than abstainers, despite a more atherogenic diet, and the mechanisms for the increased calcium scores in the former remain speculative.

Associations of fibroblast growth factor 23 and fetuin-A with coronary plaque burden and plaque composition in young adults.

Science.gov (United States)

Akin, Fatih; Celik, Omer; Ayca, Burak; Altun, Ibrahim; Diker, Vesile Ornek; Byk, Ismail; Siriopol, Dimitrie; Covic, Adrian; Kanbay, Mehmet

2015-04-01

The total burden of subclinical coronary artery disease (CAD) is significant among young adults. Serum fibroblast growth factor 23 (FGF-23) and fetuin-A are established predictors of morbidity and mortality because of cardiovascular disease. The objective of the study was to evaluate the relationship between subclinical CAD and serum FGF-23 and fetuin-A concentrations among a population of young adults. A total of 241 subjects younger than 45 years who had undergone coronary computed tomographic angiography (CCTA) were included in the study. In 117 patients, the CCTA detected subclinical CAD; the rest of the patients had no CAD detected on CCTA. Serum FGF-23 and fetuin-A levels were significantly increased in the CAD patients as compared with the non-CAD patients (26.7 [interquartile range, 22.4-31.9] vs 15.7 [interquartile range, 13.2-18.1] pg/mL and 904.7 [interquartile range, 695.5-1021.6] vs 469.6 [331.4-660.5] mg/L, respectively; P < 0.001 for both). Furthermore, a positive correlation was identified between FGF-23 and fetuin-A levels and the total number of plaques (r = 0.21 and r = 0.28, respectively; P < 0.001 for both). In multivariate logistic regression analysis, age, smoking status, uric acid, FGF-23, and fetuin-A levels were found to be independently associated with the presence of CAD. The presence of subclinical CAD is independently associated with FGF-23 and fetuin-A and could be used as novel risk markers of cardiovascular disease in the asymptomatic young adult population.

Relationship Between Quantitative Adverse Plaque Features From Coronary Computed Tomography Angiography and Downstream Impaired Myocardial Flow Reserve by 13N-Ammonia Positron Emission Tomography: A Pilot Study.

Science.gov (United States)

Dey, Damini; Diaz Zamudio, Mariana; Schuhbaeck, Annika; Juarez Orozco, Luis Eduardo; Otaki, Yuka; Gransar, Heidi; Li, Debiao; Germano, Guido; Achenbach, Stephan; Berman, Daniel S; Meave, Aloha; Alexanderson, Erick; Slomka, Piotr J

2015-10-01

We investigated the relationship of quantitative plaque features from coronary computed tomography (CT) angiography and coronary vascular dysfunction by impaired myocardial flow reserve (MFR) by (13)N-Ammonia positron emission tomography (PET). Fifty-one patients (32 men, 62.4±9.5 years) underwent combined rest-stress (13)N-ammonia PET and CT angiography scans by hybrid PET/CT. Regional MFR was measured from PET. From CT angiography, 153 arteries were evaluated by semiautomated software, computing arterial noncalcified plaque (NCP), low-density NCP (NCP<30 HU), calcified and total plaque volumes, and corresponding plaque burden (plaque volumex100%/vessel volume), stenosis, remodeling index, contrast density difference (maximum difference in luminal attenuation per unit area in the lesion), and plaque length. Quantitative stenosis, plaque burden, and myocardial mass were combined by boosted ensemble machine-learning algorithm into a composite risk score to predict impaired MFR (MFR≤2.0) by PET in each artery. Nineteen patients had impaired regional MFR in at least 1 territory (41/153 vessels). Patients with impaired regional MFR had higher arterial NCP (32.4% versus 17.2%), low-density NCP (7% versus 4%), and total plaque burden (37% versus 19.3%, P<0.02). In multivariable analysis with 10-fold cross-validation, NCP burden was the most significant predictor of impaired MFR (odds ratio, 1.35; P=0.021 for all). For prediction of impaired MFR with 10-fold cross-validation, receiver operating characteristics area under the curve for the composite score was 0.83 (95% confidence interval, 0.79-0.91) greater than for quantitative stenosis (0.66, 95% confidence interval, 0.57-0.76, P=0.005). Compared with stenosis, arterial NCP burden and a composite score combining quantitative stenosis and plaque burden from CT angiography significantly improves identification of downstream regional vascular dysfunction. © 2015 American Heart Association, Inc.

Actinic Granuloma with Focal Segmental Glomerulosclerosis

Directory of Open Access Journals (Sweden)

Ruedee Phasukthaworn

2016-02-01

Full Text Available Actinic granuloma is an uncommon granulomatous disease, characterized by annular erythematous plaque with central clearing predominately located on sun-damaged skin. The pathogenesis is not well understood, ultraviolet radiation is recognized as precipitating factor. We report a case of a 52-year-old woman who presented with asymptomatic annular erythematous plaques on the forehead and both cheeks persisting for 2 years. The clinical presentation and histopathologic findings support the diagnosis of actinic granuloma. During that period of time, she also developed focal segmental glomerulosclerosis. The association between actinic granuloma and focal segmental glomerulosclerosis needs to be clarified by further studies.

Coronary Plaque Characterization in Psoriasis Reveals High-Risk Features That Improve After Treatment in a Prospective Observational Study.

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Lerman, Joseph B; Joshi, Aditya A; Chaturvedi, Abhishek; Aberra, Tsion M; Dey, Amit K; Rodante, Justin A; Salahuddin, Taufiq; Chung, Jonathan H; Rana, Anshuma; Teague, Heather L; Wu, Jashin J; Playford, Martin P; Lockshin, Benjamin A; Chen, Marcus Y; Sandfort, Veit; Bluemke, David A; Mehta, Nehal N

2017-07-18

Psoriasis, a chronic inflammatory disease associated with an accelerated risk of myocardial infarction, provides an ideal human model to study inflammatory atherogenesis in vivo. We hypothesized that the increased cardiovascular risk observed in psoriasis would be partially attributable to an elevated subclinical coronary artery disease burden composed of noncalcified plaques with high-risk features. However, inadequate efforts have been made to directly measure coronary artery disease in this vulnerable population. As such, we sought to compare total coronary plaque burden and noncalcified coronary plaque burden (NCB) and high-risk plaque (HRP) prevalence between patients with psoriasis (n=105), patients with hyperlipidemia eligible for statin therapy under National Cholesterol Education Program-Adult Treatment Panel III guidelines (n=100) who were ≈10 years older, and healthy volunteers without psoriasis (n=25). Patients underwent coronary computed-tomography angiography for total coronary plaque burden and NCB quantification and HRP identification, defined as low attenuation (1.10), and spotty calcification. A consecutive sample of the first 50 patients with psoriasis was scanned again 1 year after therapy. Despite being younger and at lower traditional risk than patients with hyperlipidemia, patients with psoriasis had increased NCB (mean±SD: 1.18±0.33 versus 1.11±0.32, P =0.02) and similar HRP prevalence ( P =0.58). Furthermore, compared to healthy volunteers, patients with psoriasis had increased total coronary plaque burden (1.22±0.31 versus 1.04±0.22, P =0.001), NCB (1.18±0.33 versus 1.03±0.21, P =0.004), and HRP prevalence beyond traditional risk (odds ratio, 6.0; 95% confidence interval, 1.1-31.7; P =0.03). Last, among patients with psoriasis followed for 1 year, improvement in psoriasis severity was associated with improvement in total coronary plaque burden (β=0.45, 0.23-0.67; P psoriasis had greater NCB and increased HRP prevalence than

Calcified Plaque of Coronary Artery: Factors Influencing Overestimation of Coronary Artery Stenosis on Coronary CT Angiography

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Kim, Mok Hee; Kim, Yun Hyeon; Choi, Song; Seon, Hyun Ju; Jeong, Gwang Woo; Park, Jin Gyoon; Kang, Heoung Keun; Ko, Joon Seok

2010-01-01

To assess the influence of calcified plaque characteristics on the overestimation of coronary arterial stenosis on a coronary CT angiography (CCTA). The study included 271 coronary arteries with calcified plaques identified by CCTA, and based on 928 coronary arteries from 232 patients who underwent both CCTA and invasive coronary angiography (ICA). Individual coronary arteries were classified into two groups by agreement based on the degree of stenosis from each CCTA and ICA: 1) group A includes patients with concordant CCTA and ICA results and, 2) group B includes patients with an overestimation of CCTA compared to ICA. Parameters including total calcium score, calcium score of an individual coronary artery, calcium burden number of an individual coronary artery, and the density of each calcified plaque (calcium score / number of calcium burden) for each individual coronary artery were compared between the two groups. Of the 271 coronary arteries, 164 (60.5%) were overestimated on CCTA. The left anterior descending artery (LAD) had a significantly low rate of overestimation (47.1%) compared to the other coronary arteries (p=0.001). No significant differences for total calcium score, calcium score of individual coronary artery, and the density of each calcified plaque from individual coronary arteries between two groups was observed. However, a decreasing tendency for the rate of overestimation on CCTA was observed with an increase in calcium burden of individual coronary arteries (p<0.05). The evaluation of coronary arteries suggests that the degree of coronary arterial stenosis had a tendency to be overestimated by calcified plaques on CCTA. However, the rate of overestimation for the degree of coronary arterial stenosis by calcified plaques was not significantly influenced by total calcium score, calcium score of individual coronary artery, and density of each calcified plaque

T1-weighted MRI for the detection of coronary artery plaque haemorrhage

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Oei, May Lin; Ozgun, Murat; Seifarth, Harald; Bunck, Alexander; Fischbach, Roman; Heindel, Walter; Maintz, David; Orwat, Stefan; Botnar, Rene

2010-01-01

Hyperintense areas in atherosclerotic plaques on pre-contrast T1-weighted MRI have been shown to correlate with intraplaque haemorrhage. We evaluated the presence of T1 hyperintensity in coronary artery plaques in coronary artery disease (CAD) patients and correlated results with multi-detector computed tomography (MDCT) findings. Fifteen patients with CAD were included. Plaques detected by MDCT were categorised based on their Hounsfield number. T1-weighted inversion recovery (IR) MRI prepared coronary MRI for the detection of plaque and steady-state free-precession coronary MR-angiography for anatomical correlation was performed. After registration of MDCT and MRI, regions of interest were defined on MDCT-visible plaques and in corresponding vessel segments acquired with MRI. MDCT density and MR signal measurement were performed in each plaque. Forty-three plaques were identified with MDCT. With IR-MRI 5/43 (12%) plaques were hyperintense, 2 of which were non-calcified and 3 mixed. Average signal-to-noise and contrast-to-noise ratios of hyperintense plaques were 15.7 and 9.1, compared with 5.6 and 1.2 for hypointense plaques. Hyperintense plaques exhibited a significantly lower CT density than hypointense plaques (63.6 vs. 140.8). There was no correlation of plaque signal intensity with degree of stenosis. T1-weighted IR-MRI may be useful for non-invasive detection and characterisation of intraplaque haemorrhage in coronary artery plaques. (orig.)

Comparing culprit lesions in ST-segment elevation and non-ST-segment elevation acute coronary syndrome with 64-slice multidetector computed tomography

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Huang, W.-C. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: w.c.huang@yahoo.com.tw; Liu, C.-P. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: cpliu@isca.vghks.gov.tw; Wu, M.-T. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Department of Radiology, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: wu.mingting@gmail.com; Mar, G.-Y. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: gymar@isca.vghks.gov.tw; Lin, S.-K. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: skyii89@yahoo.com.tw; Hsiao, S.-H. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: a841120@ms3.hinet.net; Lin, S.-L. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: sllin@isca.vghks.gov.tw; Chiou, K.-R. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: krchiou@isca.vghks.gov.tw

2010-01-15

Background: Classifying acute coronary syndrome (ACS) as ST elevation ACS (STE-ACS) or non-ST elevation ACS (NSTE-ACS) is critical for clinical prognosis and therapeutic decision-making. Assessing the differences in composition and configuration of culprit lesions between STE-ACS and NSTE-ACS can clarify their pathophysiologic differences. Objective: This study focused on evaluating the ability of 64-slice multidetector computed tomography (MDCT) to investigate these differences in culprit lesions in patients with STE-ACS and NSTE-ACS. Methods: Of 161 ACS cases admitted, 120 who fit study criteria underwent MDCT and conventional coronary angiography. The following MDCT data were analyzed: calcium volume, Agatston calcium scores, plaque area, plaque burden, remodeling index, and plaque density. Results: The MDCT angiography had a good correlation with conventional coronary angiography regarding the stenotic severity of culprit lesions (r = 0.86, p < 0.001). The STE-ACS culprit lesions (n = 54) had significantly higher luminal area stenosis (78.6 {+-} 21.2% vs. 66.7 {+-} 23.9%, p = 0.006), larger plaque burden (0.91 {+-} 0.10 vs. 0.84 {+-} 0.12, p = 0.007) and remodeling index (1.28 {+-} 0.34 vs. 1.16 {+-} 0.22, p = 0.021) than those with NSTE-ACS (n = 66). The percentage of expanding remodeling index (remodeling index >1.05) was significantly higher in the STE-ACS group (81.5% vs. 63.6%, p = 0.031). The patients with STE-ACS had significantly lower MDCT density of culprit lesions than patients with NSTE-ACS (25.8 {+-} 13.9 HU vs. 43.5 {+-} 19.1 HU, p < 0.001). Conclusions: Sixty-four-slice MDCT can accurately evaluate the stenotic severity and composition of culprit lesions in selected patients with either STE-ACS or NSTE-ACS. Culprit lesions in NSTE-ACS patients had significantly lower luminal area stenosis, plaque burden, remodeling index and higher MDCT density, which possibly reflect differences in the composition of vulnerable culprit plaques and thrombi.

Localization of oxidized low-density lipoprotein and its relation to plaque morphology in human coronary artery.

Directory of Open Access Journals (Sweden)

Yasumi Uchida

Full Text Available OBJECTIVES: Oxidized low-density lipoprotein (oxLDL plays a key role in the formation of atherosclerotic plaques. However, its localization in human coronary arterial wall is not well understood. The present study was performed to visualize deposition sites and patterns of native oxLDL and their relation to plaque morphology in human coronary artery. METHODS: Evans blue dye (EB elicits a violet fluorescence by excitation at 345-nm and emission at 420-nm, and a reddish-brown fluorescence by excitation at 470-nm and emission at 515-nm characteristic of oxLDL only. Therefore, native oxLDL in excised human coronary artery were investigated by color fluorescent microscopy (CFM using EB as a biomarker. RESULTS: (1 By luminal surface scan with CFM, the % incidence of oxLDL in 38 normal segments, 41 white plaques and 32 yellow plaques that were classified by conventional angioscopy, was respectively 26, 44 and 94, indicating significantly (p<0.05 higher incidence in the latter than the former two groups. Distribution pattern was classified as patchy, diffuse and web-like. Web-like pattern was observed only in yellow plaques with necrotic core. (2 By transected surface scan, oxLDL deposited within superficial layer in normal segments and diffusely within both superficial and deep layers in white and yellow plaques. In yellow plaques with necrotic core, oxLDL deposited not only in the marginal zone of the necrotic core but also in the fibrous cap. CONCLUSION: Taken into consideration of the well-known process of coronary plaque growth, the results suggest that oxLDL begins to deposit in human coronary artery wall before plaque formation and increasingly deposits with plaque growth, exhibiting different deposition sites and patterns depending on morphological changes.

Framework for detection and localization of coronary non-calcified plaques in cardiac CTA using mean radial profiles.

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Jawaid, Muhammad Moazzam; Riaz, Atif; Rajani, Ronak; Reyes-Aldasoro, Constantino Carlos; Slabaugh, Greg

2017-10-01

The high mortality rate associated with coronary heart disease (CHD) has driven intensive research in cardiac imaging and image analysis. The advent of computed tomography angiography (CTA) has turned non-invasive diagnosis of cardiovascular anomalies into reality as calcified coronary plaques can be easily identified due to their high intensity values. However, the detection of non-calcified plaques in CTA is still a challenging problem because of lower intensity values, which are often similar to the nearby blood and muscle tissues. In this work, we propose the use of mean radial profiles for the detection of non-calcified plaques in CTA imagery. Accordingly, we computed radial profiles by averaging the image intensity in concentric rings around the vessel centreline in a first stage. In the subsequent stage, an SVM classifier is applied to identify the abnormal coronary segments. For occluded segments, we further propose a derivative-based method to localize the position and length of the plaque inside the segment. A total of 32 CTA volumes were analysed and a detection accuracy of 88.4% with respect to the manual expert was achieved. The plaque localization accuracy was computed using the Dice similarity coefficient and a mean of 83.2% was achieved. The consistent performance for multi-vendor, multi-institution data demonstrates the reproducibility of our method across different CTA datasets with a good agreement with manual expert annotations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanisms of erosion of atherosclerotic plaques.

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Quillard, Thibaut; Franck, Grégory; Mawson, Thomas; Folco, Eduardo; Libby, Peter

2017-10-01

The present review explores the mechanisms of superficial intimal erosion, a common cause of thrombotic complications of atherosclerosis. Human coronary artery atheroma that give rise to thrombosis because of erosion differ diametrically from those associated with fibrous cap rupture. Eroded lesions characteristically contain few inflammatory cells, abundant extracellular matrix, and neutrophil extracellular traps (NETs). Innate immune mechanisms such as engagement of Toll-like receptor 2 (TLR2) on cultured endothelial cells can impair their viability, attachment, and ability to recover a wound. Hyaluronan fragments may serve as endogenous TLR2 ligands. Mouse experiments demonstrate that flow disturbance in arteries with neointimas tailored to resemble features of human eroded plaques disturbs endothelial cell barrier function, impairs endothelial cell viability, recruits neutrophils, and provokes endothelial cells desquamation, NET formation, and thrombosis in a TLR2-dependent manner. Mechanisms of erosion have received much less attention than those that provoke plaque rupture. Intensive statin treatment changes the characteristic of plaques that render them less susceptible to rupture. Thus, erosion may contribute importantly to the current residual burden of risk. Understanding the mechanisms of erosion may inform the development and deployment of novel therapies to combat the remaining atherothrombotic risk in the statin era.

Regression of coronary atherosclerosis with infusions of the high-density lipoprotein mimetic CER-001 in patients with more extensive plaque burden.

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Kataoka, Yu; Andrews, Jordan; Duong, MyNgan; Nguyen, Tracy; Schwarz, Nisha; Fendler, Jessica; Puri, Rishi; Butters, Julie; Keyserling, Constance; Paolini, John F; Dasseux, Jean-Louis; Nicholls, Stephen J

2017-06-01

CER-001 is an engineered pre-beta high-density lipoprotein (HDL) mimetic, which rapidly mobilizes cholesterol. Infusion of CER-001 3 mg/kg exhibited a potentially favorable effect on plaque burden in the CHI-SQUARE (Can HDL Infusions Significantly Quicken Atherosclerosis Regression) study. Since baseline atheroma burden has been shown as a determinant for the efficacy of HDL infusions, the degree of baseline atheroma burden might influence the effect of CER-001. CHI-SQUARE compared the effect of 6 weekly infusions of CER-001 (3, 6 and 12 mg/kg) vs. placebo on coronary atherosclerosis in 369 patients with acute coronary syndrome (ACS) using serial intravascular ultrasound (IVUS). Baseline percent atheroma volume (B-PAV) cutoff associated with atheroma regression following CER-001 infusions was determined by receiver-operating characteristics curve analysis. 369 subjects were stratified according to the cutoff. The effect of CER-001 at different doses was compared to placebo in each group. A B-PAV ≥30% was the optimal cutoff associated with PAV regression following CER-001 infusions. CER-001 induced PAV regression in patients with B-PAV ≥30% but not in those with B-PAV CER-001 3mg/kg in patients with B-PAV ≥30% (-0.96%±0.34% vs. -0.25%±0.31%, P=0.01), whereas there were no differences between placebo (+0.09%±0.36%) versus CER-001 in patients with B-PAV CER-001 3 mg/kg induced the greatest atheroma regression in ACS patients with higher B-PAV. These findings identify ACS patients with more extensive disease as most likely to benefit from HDL mimetic therapy.

Clinical and angiographic characteristics of patients likely to have vulnerable plaques: analysis from the PROSPECT study.

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Bourantas, Christos V; Garcia-Garcia, Hector M; Farooq, Vasim; Maehara, Akiko; Xu, Ke; Généreux, Philippe; Diletti, Roberto; Muramatsu, Takashi; Fahy, Martin; Weisz, Giora; Stone, Gregg W; Serruys, Patrick W

2013-12-01

This study sought to determine the clinical and angiographic variables that would identify patients with high-risk "vulnerable" coronary plaques. In the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study, in patients successfully treated for acute coronary syndrome (ACS), plaque composition, plaque burden, and minimal luminal area as detected by 3-vessel radiofrequency intravascular ultrasound (IVUS) imaging were associated with an increased risk of developing future events from untreated atherosclerotic lesions (vulnerable plaques). Whether baseline demographic and angiographic findings can be used to identify patients most likely to have vulnerable coronary plaques has not been examined. On the basis of 3-vessel radiofrequency IVUS imaging, patents in the PROSPECT trial were classified in 2 groups according to whether or not one or more untreated high-risk plaques were present, defined as having ≥2 high-risk features (a thin-cap fibroatheroma, plaque burden ≥70%, and/or minimal luminal area ≤4 mm(2)). The high-risk group (those with one or more high-risk lesions) had higher Framingham risk score (7.5 ± 3.4 vs. 6.9 ± 3.3; p = 0.04), more extensive coronary artery disease, and more nonculprit lesion-related cardiovascular events during the 3-year follow-up (hazard ratio: 2.63; 95% confidence interval: 1.62 to 3.66; p < 0.0001). However, demographic factors had poor discrimination in detecting high-risk patients (area under the curve 0.55), and discrimination was only slightly improved when angiographic variables were entered into the model (area under the curve 0.64). Clinical and angiographic characteristics had poor predictive accuracy in identifying patients with untreated high-risk plaques related to future adverse events. This finding highlights the potential value of comprehensive 3-vessel imaging assessment (either invasive or noninvasive) to evaluate plaque phenotype for more accurate risk

Vitamin K-antagonists accelerate atherosclerotic calcification and induce a vulnerable plaque phenotype.

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Leon J Schurgers

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

Multiple yellow plaques assessed by angioscopy with quantitative colorimetry in patients with myocardial infarction.

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Inami, Shigenobu; Ishibashi, Fumiyuki; Waxman, Sergio; Okamatsu, Kentaro; Seimiya, Koji; Takano, Masamichi; Uemura, Ryota; Sano, Junko; Mizuno, Kyoichi

2008-03-01

Multiple angioscopic yellow plaques are associated with diffuse atherosclerotic plaque, and may be prevalent in patients with myocardial infarction (MI), so in the present study the yellow plaques in the coronary arteries of patients with MI was evaluated using quantitative colorimetry, and compared with those of patients with stable angina (SA). In the recorded angioscopic images of 3 coronary vessels in 29 patients (15 patients with MI, 14 with SA), yellow plaques were determined as visually yellow regions with b* value >0 (yellow color intensity) measured by the quantitative colorimetric method. A total of 90 yellow plaques were identified (b* =19.35+/-8.3, 3.05-45.35). Yellow plaques were significantly more prevalent in 14 (93%) of 15 culprit lesions of MI as compared with 8 (57%) of 14 of SA (p=0.03). In non-culprit segments, yellow plaques were similarly prevalent in 13 (87%) patients with MI and 11 (79%) with SA (p=0.65). Overall, multiple (> or =2) yellow plaques were prevalent in 13 (87%) patients with MI, similar to the 10 (71%) with SA (p=0.38). The number of yellow plaques was significantly higher in patients with MI (3.8+/-1.9) than in those with SA (2.4+/-1.6, p=0.03). The present study suggests that patients with MI tend to have diffuse atherosclerotic plaque in their coronary arteries.

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

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

2009-01-01

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

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

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

2013-01-01

Previous studies have shown that coronary plaque composition plays a pivotal role in plaque instability, and imaging modalities and serum biomarkers have been investigated to identify vulnerable plaque. Virtual histology IVUS (VH-IVUS) characterizes plaque components as calcified, fibrotic, fibrofatty, or necrotic core. C-reactive protein (hsCRP) is an independent risk factor and a powerful predictor of future coronary events. However, a relationship between inflammatory response indicated by CRP and plaque characteristics in ACS patients remains not well established. To determine, by using VH-IVUS, the relation between coronary plaque components and plasma high-sensitivity CRP levels in patients with acute coronary syndromes (ACS). 52 patients with ACS were enrolled in this prospective study. Electrocardiographically-gated VH-IVUS were performed in the culprit lesion before PCI. Blood sample was drawn from all patients before the procedure and after 24 hours, and hs-CRP levels were determined. Mean age was 55.3±4.9 years, 76.9% were men and 30.9% had diabetes. Mean MLA was 3.9±1.3 mm 2 , and plaque burden was 69±11.3%, as assessed by IVUS. VH-IVUS analysis at the minimum luminal site identified plaque components: fibrotic (59.6±15.8%), fibrofatty (7.6±8.2%), dense calcium (12.1±9.2%) and necrotic core (20.7±12.7%). Plasma hs-CRP (mean 16.02±18.07 mg/L) did not correlate with necrotic core (r=-0.089, p = 0.53) and other plaque components. In this prospective study with patients with ACS, the predominant components of the culprit plaque were fibrotic and necrotic core. Serum hs C-reactive protein levels did not correlate with plaque composition

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

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Siqueira, Dimytri Alexandre de Alvim, E-mail: dimytri@cardiol.br; Sousa, Amanda Guerra Moraes R.; Costa Junior, José de Ribamar; Costa, Ricardo Alves da; Staico, Rodolfo; Tanajura, Luis Fernando Leite; Centemero, Marinella Patrizia; Feres, Fausto; Abizaid, Alexandre Antonio Cunha; Sousa, J. Eduardo Moraes R. [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

2013-07-15

Previous studies have shown that coronary plaque composition plays a pivotal role in plaque instability, and imaging modalities and serum biomarkers have been investigated to identify vulnerable plaque. Virtual histology IVUS (VH-IVUS) characterizes plaque components as calcified, fibrotic, fibrofatty, or necrotic core. C-reactive protein (hsCRP) is an independent risk factor and a powerful predictor of future coronary events. However, a relationship between inflammatory response indicated by CRP and plaque characteristics in ACS patients remains not well established. To determine, by using VH-IVUS, the relation between coronary plaque components and plasma high-sensitivity CRP levels in patients with acute coronary syndromes (ACS). 52 patients with ACS were enrolled in this prospective study. Electrocardiographically-gated VH-IVUS were performed in the culprit lesion before PCI. Blood sample was drawn from all patients before the procedure and after 24 hours, and hs-CRP levels were determined. Mean age was 55.3±4.9 years, 76.9% were men and 30.9% had diabetes. Mean MLA was 3.9±1.3 mm{sup 2}, and plaque burden was 69±11.3%, as assessed by IVUS. VH-IVUS analysis at the minimum luminal site identified plaque components: fibrotic (59.6±15.8%), fibrofatty (7.6±8.2%), dense calcium (12.1±9.2%) and necrotic core (20.7±12.7%). Plasma hs-CRP (mean 16.02±18.07 mg/L) did not correlate with necrotic core (r=-0.089, p = 0.53) and other plaque components. In this prospective study with patients with ACS, the predominant components of the culprit plaque were fibrotic and necrotic core. Serum hs C-reactive protein levels did not correlate with plaque composition.

Veins in plaques of multiple sclerosis patients - a longitudinal magnetic resonance imaging study at 7 Tesla

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Dal-Bianco, Assunta; Auff, Eduard; Leutmezer, Fritz; Vass, Karl [Medical University of Vienna, Department of Neurology, Wien (Austria); Hametner, Simon [Medical University of Vienna, Center for Brain Research, Wien (Austria); Grabner, Guenther; Schernthaner, Melanie; Kronnerwetter, Claudia; Trattnig, Siegfried [Medical University of Vienna, Department of Radiology, Wien (Austria); Reitner, Andreas; Vass, Clemens; Kircher, Karl [Medical University of Vienna, Department of Ophthalmology, Wien (Austria)

2015-10-15

To monitor the venous volumes in plaques of patients with multiple sclerosis (MS) compared to an age-matched control group over a period of 3.5 years. Ten MS patients underwent an annual neurological examination and MRI. Susceptibility-weighted imaging (SWI) combined with fluid-attenuated inversion recovery (FLAIR) or FLAIR-like contrast at 7 Tesla (7 T) magnetic resonance imaging (MRI) was used for manual segmentation of veins in plaques, in the normal-appearing white matter (NAWM) and in location-matched white matter of 9 age-matched controls. Venous volume to tissue volume ratio was assessed for each time point in order to describe the dynamics of venous volumes in MS plaques over time. MS plaques, which were newly detected during the study period, showed significantly higher venous volumes compared to the preplaque area 1 year before plaque detection and the corresponding NAWM regions. Venous volumes in established MS plaques, which were present already in the first scans, were significantly higher compared to the NAWM and controls. Our data underpin a relation of veins and plaque development in MS and reflect increased apparent venous calibers due to increased venous diameters or increased oxygen consumption in early MS plaques. (orig.)

Veins in plaques of multiple sclerosis patients - a longitudinal magnetic resonance imaging study at 7 Tesla

International Nuclear Information System (INIS)

Dal-Bianco, Assunta; Auff, Eduard; Leutmezer, Fritz; Vass, Karl; Hametner, Simon; Grabner, Guenther; Schernthaner, Melanie; Kronnerwetter, Claudia; Trattnig, Siegfried; Reitner, Andreas; Vass, Clemens; Kircher, Karl

2015-01-01

To monitor the venous volumes in plaques of patients with multiple sclerosis (MS) compared to an age-matched control group over a period of 3.5 years. Ten MS patients underwent an annual neurological examination and MRI. Susceptibility-weighted imaging (SWI) combined with fluid-attenuated inversion recovery (FLAIR) or FLAIR-like contrast at 7 Tesla (7 T) magnetic resonance imaging (MRI) was used for manual segmentation of veins in plaques, in the normal-appearing white matter (NAWM) and in location-matched white matter of 9 age-matched controls. Venous volume to tissue volume ratio was assessed for each time point in order to describe the dynamics of venous volumes in MS plaques over time. MS plaques, which were newly detected during the study period, showed significantly higher venous volumes compared to the preplaque area 1 year before plaque detection and the corresponding NAWM regions. Venous volumes in established MS plaques, which were present already in the first scans, were significantly higher compared to the NAWM and controls. Our data underpin a relation of veins and plaque development in MS and reflect increased apparent venous calibers due to increased venous diameters or increased oxygen consumption in early MS plaques. (orig.)

Optimization of dual-wavelength intravascular photoacoustic imaging of atherosclerotic plaques using Monte Carlo optical modeling

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Dana, Nicholas; Sowers, Timothy; Karpiouk, Andrei; Vanderlaan, Donald; Emelianov, Stanislav

2017-10-01

Coronary heart disease (the presence of coronary atherosclerotic plaques) is a significant health problem in the industrialized world. A clinical method to accurately visualize and characterize atherosclerotic plaques is needed. Intravascular photoacoustic (IVPA) imaging is being developed to fill this role, but questions remain regarding optimal imaging wavelengths. We utilized a Monte Carlo optical model to simulate IVPA excitation in coronary tissues, identifying optimal wavelengths for plaque characterization. Near-infrared wavelengths (≤1800 nm) were simulated, and single- and dual-wavelength data were analyzed for accuracy of plaque characterization. Results indicate light penetration is best in the range of 1050 to 1370 nm, where 5% residual fluence can be achieved at clinically relevant depths of ≥2 mm in arteries. Across the arterial wall, fluence may vary by over 10-fold, confounding plaque characterization. For single-wavelength results, plaque segmentation accuracy peaked at 1210 and 1720 nm, though correlation was poor (blood, a primary and secondary wavelength near 1210 and 1350 nm, respectively, may offer the best implementation of dual-wavelength IVPA imaging. These findings could guide the development of a cost-effective clinical system by highlighting optimal wavelengths and improving plaque characterization.

Quantification and visualization of carotid segmentation accuracy and precision using a 2D standardized carotid map

International Nuclear Information System (INIS)

Chiu, Bernard; Ukwatta, Eranga; Shavakh, Shadi; Fenster, Aaron

2013-01-01

This paper describes a framework for vascular image segmentation evaluation. Since the size of vessel wall and plaque burden is defined by the lumen and wall boundaries in vascular segmentation, these two boundaries should be considered as a pair in statistical evaluation of a segmentation algorithm. This work proposed statistical metrics to evaluate the difference of local vessel wall thickness (VWT) produced by manual and algorithm-based semi-automatic segmentation methods (ΔT) with the local segmentation standard deviation of the wall and lumen boundaries considered. ΔT was further approximately decomposed into the local wall and lumen boundary differences (ΔW and ΔL respectively) in order to provide information regarding which of the wall and lumen segmentation errors contribute more to the VWT difference. In this study, the lumen and wall boundaries in 3D carotid ultrasound images acquired for 21 subjects were each segmented five times manually and by a level-set segmentation algorithm. The (absolute) difference measures (i.e., ΔT, ΔW, ΔL and their absolute values) and the pooled local standard deviation of manually and algorithmically segmented wall and lumen boundaries were computed for each subject and represented in a 2D standardized map. The local accuracy and variability of the segmentation algorithm at each point can be quantified by the average of these metrics for the whole group of subjects and visualized on the 2D standardized map. Based on the results shown on the 2D standardized map, a variety of strategies, such as adding anchor points and adjusting weights of different forces in the algorithm, can be introduced to improve the accuracy and variability of the algorithm. (paper)

[Qualitative and quantitative diagnostic performance of 320-slice computed tomography for detecting coronary artery disease with respect to atherosclerotic plaque characteristics].

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Li, Suhua; Liu, Jinlai; Peng, Long; Dong, Ruimin; Wu, Huilan; Wang, Chenlin; Ni, Qiongqiong; Luo, Yanting; Zhu, Jieming; Chen, Lin

2014-10-28

To investigate qualitatively and quantitatively the diagnostic performance of 320-slice CT for detection of coronary artery disease with respect to different atherosclerotic plaque characteristics. A retrospective search was performed for inpatients underwent both coronary CT and further coronary angiography (CAG) from December 1, 2008 to December 31, 2012. The diagnostic performance of 320-slice CTA for detecting significant stenosis ( ≥ 50% diameter) with respect to atherosclerotic plaque characteristics were analyzed by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, kappa index (κ), and area under the receiver operating characteristic curve (AUC). Chi-square test was used to evaluate whether there were significant differences of the true-case frequency (true positive + true negative) and false-case frequency (false positive + false negative) among groups. Bland-Altman analysis was used to determine limits of agreement between CTA and CAG. A total of 454 patients and 6 779 segments were analyzed. Diagnostic accuracy was higher in non-calcified segments; whereas they decreased in the presence of both mild-moderately and heavily calcified plaques. Excellent agreement (κ = 0.810) between CT and CAG was observed for non-calcified segments, while good agreement was observed for both mild-moderately (κ = 0.701) and heavily calcified segments (κ = 0.750). Both mild-moderate (P = 0.000) and heavy (P = 0.000) calcification decreased the true-case frequency and increased the false-case frequency when compared to non-calcification. There were no significant underestimation or overestimation for non-calcified (P = 0.087) and mild-moderately calcified (P = 0.704) segments, while there was significant overestimation for heavily calcified segments (P = 0.001). Great qualitative and quantitative diagnostic performances of 320-slice CT were observed in non-calcified coronary segments. However, qualitative

Effect of high-intensity statin therapy on atherosclerosis in non-infarct-related coronary arteries (IBIS-4)

DEFF Research Database (Denmark)

Räber, Lorenz; Taniwaki, Masanori; Zaugg, Serge

2015-01-01

AIM: The effect of long-term high-intensity statin therapy on coronary atherosclerosis among patients with acute ST-segment elevation myocardial infarction (STEMI) is unknown. The aim of this study was to quantify the impact of high-intensity statin therapy on plaque burden, composition, and phen......AIM: The effect of long-term high-intensity statin therapy on coronary atherosclerosis among patients with acute ST-segment elevation myocardial infarction (STEMI) is unknown. The aim of this study was to quantify the impact of high-intensity statin therapy on plaque burden, composition......-infarct-related epicardial coronary arteries (non-IRA) after successful primary PCI. Patients were treated with high-intensity rosuvastatin (40 mg/day) throughout 13 months and serial intracoronary imaging with the analysis of matched segments was available for 82 patients with 146 non-IRA. The primary IVUS end...

Inter-Scan Reproducibility of Carotid Plaque Volume Measurements by 3-D Ultrasound

DEFF Research Database (Denmark)

Sandholt, Benjamin V; Collet-Billon, Antoine; Entrekin, Robert

2018-01-01

(PPV) measure centered on MPT. Total plaque volume (TPV), PPV from a 10-mm segment and MPT were measured using dedicated semi-automated software on 38 plaques from 26 patients. Inter-scan reproducibility was assessed using the t-test, Bland-Altman plots and Pearson's correlation coefficient....... There was a mean difference of 0.01 mm in MPT (limits of agreement: -0.45 to 0.42 mm, Pearson's correlation coefficient: 0.96). Both volume measurements exhibited high reproducibility, with PPV being superior (limits of agreement: -35.3 mm3to 33.5 mm3, Pearson's correlation coefficient: 0.96) to TPV (limits...... of agreement: -88.2 to 61.5 mm3, Pearson's correlation coefficient: 0.91). The good reproducibility revealed by the present results encourages future studies on establishing plaque quantification as part of cardiovascular risk assessment and for follow-up of disease progression over time....

Plaque echodensity and textural features are associated with histologic carotid plaque instability.

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Doonan, Robert J; Gorgui, Jessica; Veinot, Jean P; Lai, Chi; Kyriacou, Efthyvoulos; Corriveau, Marc M; Steinmetz, Oren K; Daskalopoulou, Stella S

2016-09-01

Carotid plaque echodensity and texture features predict cerebrovascular symptomatology. Our purpose was to determine the association of echodensity and textural features obtained from a digital image analysis (DIA) program with histologic features of plaque instability as well as to identify the specific morphologic characteristics of unstable plaques. Patients scheduled to undergo carotid endarterectomy were recruited and underwent carotid ultrasound imaging. DIA was performed to extract echodensity and textural features using Plaque Texture Analysis software (LifeQ Medical Ltd, Nicosia, Cyprus). Carotid plaque surgical specimens were obtained and analyzed histologically. Principal component analysis (PCA) was performed to reduce imaging variables. Logistic regression models were used to determine if PCA variables and individual imaging variables predicted histologic features of plaque instability. Image analysis data from 160 patients were analyzed. Individual imaging features of plaque echolucency and homogeneity were associated with a more unstable plaque phenotype on histology. These results were independent of age, sex, and degree of carotid stenosis. PCA reduced 39 individual imaging variables to five PCA variables. PCA1 and PCA2 were significantly associated with overall plaque instability on histology (both P = .02), whereas PCA3 did not achieve statistical significance (P = .07). DIA features of carotid plaques are associated with histologic plaque instability as assessed by multiple histologic features. Importantly, unstable plaques on histology appear more echolucent and homogeneous on ultrasound imaging. These results are independent of stenosis, suggesting that image analysis may have a role in refining the selection of patients who undergo carotid endarterectomy. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Periodontal disease burden and pathological changes in organs of dogs.

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Pavlica, Zlatko; Petelin, Milan; Juntes, Polona; Erzen, Damjan; Crossley, David A; Skaleric, Uros

2008-06-01

Bacterial plaque associated periodontal disease is the most common chronic infection in man and dogs. In man, there is an association between periodontal disease and myocardial infarction and stroke, while in dogs it has also been associated with changes in internal organs. Inflamed periodontal tissues present a 'periodontal disease burden' to the host and the extent of this inflammatory disease burden is likely to affect the degree of associated pathological change in distant organs. This hypothesis was investigated in dogs with naturally occurring periodontal disease. Post-mortem investigations including periodontal assessment, standard necropsy, and organ histology were performed on 44 mature toy and miniature Poodles (related, periodontitis predisposed breeds) that died naturally or were euthanized based on clinical disease. Animals with gross primary organ pathology were excluded. The periodontal disease burden was estimated from the total surface area of periodontal pocket epithelium using six measurements of probing depth for each tooth and the tooth circumferences. Ordinal logistic regression (OR) analysis established that for each square centimeter of periodontal disease burden there was a 1.4-times higher likelihood of greater changes being present in the left atrio-ventricular valves (OR = 1.43), plus 1.2 and 1.4 times higher likelihoodfor greater liver and kidney pathology (OR = 1.21; OR = 1.42), respectively The results show that there is a link between the estimated 'periodontal disease burden' resulting from plaque-bacteria associated periodontal disease and the level of internal pathology in this population, implying that periodontitis might contribute to the development of systemic pathology in dogs.

Comparison between a new computer program and the reference software for gray-scale median analysis of atherosclerotic carotid plaques.

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Casella, Ivan Benaduce; Fukushima, Rodrigo Bono; Marques, Anita Battistini de Azevedo; Cury, Marcus Vinícius Martins; Presti, Calógero

2015-03-01

To compare a new dedicated software program and Adobe Photoshop for gray-scale median (GSM) analysis of B-mode images of carotid plaques. A series of 42 carotid plaques generating ≥50% diameter stenosis was evaluated by a single observer. The best segment for visualization of internal carotid artery plaque was identified on a single longitudinal view and images were recorded in JPEG format. Plaque analysis was performed by both programs. After normalization of image intensity (blood = 0, adventitial layer = 190), histograms were obtained after manual delineation of plaque. Results were compared with nonparametric Wilcoxon signed rank test and Kendall tau-b correlation analysis. GSM ranged from 00 to 100 with Adobe Photoshop and from 00 to 96 with IMTPC, with a high grade of similarity between image pairs, and a highly significant correlation (R = 0.94, p < .0001). IMTPC software appears suitable for the GSM analysis of carotid plaques. © 2014 Wiley Periodicals, Inc.

The association between gallstone disease and plaque in the abdominopelvic arteries

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Halil Ibrahim Serin

2017-01-01

Full Text Available Background: The aim of this study was to assess the atheromatous plaque, in the abdominopelvic arteries as a marker of cardiac risk in patients with or without gallstone disease (GD. Materials and Methods: A total of 136 patients were enrolled in this cross-sectional study. Forty-eight patients had GD and the remaining 88 patients did not. The presence or absence of gallstones was noted during abdominal ultrasonography while vascular risk factors such as plaque formation, intima-media thickness, plaque calcification, mural thrombus, stenosis, aneurysm, and inflammation were recorded during an abdominopelvic computed tomography scan. In addition, percentage of the abdominopelvic aorta surface covered by atheromatous plaque was calculated. Results: The mean age of patients with GD and without GD was 50.81 ± 16.20 and 50.40 ± 12.43, respectively. Patients with GD were more likely to have diabetes mellitus, a higher body mass index (BMI (P < 0.001, and higher cholesterol (P < 0.01, and low-density lipoprotein-cholesterol (P < 0.02 levels. No significant differences were found between the groups regarding other atherosclerotic risk factors. Patients with GD had significantly higher rates of the vascular risk factors as intima-media thickness, plaque formation, calcification, aneurysm, mural thrombosis, stenosis, and inflammation in all abdominal arterial segments other than aneurysm in the femoral arteries. In addition, patients with GD had severe atheromatous plaques in the abdominal aorta, common iliac, external iliac, and common femoral artery (CFA. In patients with GD, parameters of age, BMI, and systolic and diastolic blood pressure were all correlated with the severity of the atheromatous plaque in abdominal aorta, common iliac, external iliac, and CFA. Conclusion: We demonstrated a direct relationship between GD and abdominopelvic atheromatous plaque, which is a marker for increased cardiovascular risk, for the first time in the literature

An assessment on the incremental value of high-resolution magnetic resonance imaging to identify culprit plaques in atherosclerotic disease of the middle cerebral artery

International Nuclear Information System (INIS)

Teng, Zhongzhao; Graves, Martin J.; Gillard, Jonathan H.; Peng, Wenjia; Zhan, Qian; Zhang, Xuefeng; Liu, Qi; Chen, Shiyue; Tian, Xia; Chen, Luguang; Lu, Jianping; Brown, Adam J.

2016-01-01

Although certain morphological features depicted by high resolution, multi-contrast magnetic resonance imaging (hrMRI) have been shown to be different between culprit and non-culprit middle cerebral artery (MCA) atherosclerotic lesions, the incremental value of hrMRI to define culprit lesions over stenosis has not been assessed. Patients suspected with MCA stenosis underwent hrMRI. Lumen and outer wall were segmented to calculate stenosis, plaque burden (PB), volume (PV), length (PL) and minimum luminal area (MLA). Data from 165 lesions (112 culprit and 53 non-culprit) in 139 individuals were included. Culprit lesions were larger and longer with a narrower lumen and increased PB compared with non-culprit lesions. More culprit lesions showed contrast enhancement. Both PB and MLA were better indicators than stenosis in differentiating lesion types (AUC were 0.649, 0.732 and 0.737 for stenosis, PB and MLA, respectively). Combinations of PB, MLA and stenosis could improve positive predictive value (PPV) and specificity significantly. An optimal combination of stenosis ≥ 50 %, PB ≥ 77 % and MLA ≤ 2.0 mm 2 produced a PPV = 85.7 %, negative predictive value = 54.1 %, sensitivity = 69.6 %, specificity = 75.5 %, and accuracy = 71.5 %. hrMRI plaque imaging provides incremental information to luminal stenosis in identifying culprit lesions. (orig.)

Matrix vesicles in the fibrous cap of atherosclerotic plaque: possible contribution to plaque rupture.

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Bobryshev, Y V; Killingsworth, M C; Lord, R S A; Grabs, A J

2008-10-01

Plaque rupture is the most common type of plaque complication and leads to acute ischaemic events such as myocardial infarction and stroke. Calcification has been suggested as a possible indicator of plaque instability. Although the role of matrix vesicles in the initial stages of arterial calcification has been recognized, no studies have yet been carried out to examine a possible role of matrix vesicles in plaque destabilization. Tissue specimens selected for the present study represented carotid specimens obtained from patients undergoing carotid endarterectomy. Serial frozen cross-sections of the tissue specimens were cut and mounted on glass slides. The thickness of the fibrous cap (FCT) in each advanced atherosclerotic lesion, containing a well developed lipid/necrotic core, was measured at its narrowest sites in sets of serial sections. According to established criteria, atherosclerotic plaque specimens were histologically subdivided into two groups: vulnerable plaques with thin fibrous caps (FCT <100 microm) and presumably stable plaques, in which fibrous caps were thicker than 100 microm. Twenty-four carotid plaques (12 vulnerable and 12 presumably stable plaques) were collected for the present analysis of matrix vesicles in fibrous caps. In order to provide a sufficient number of representative areas from each plaque, laser capture microdissection (LCM) was carried out. The quantification of matrix vesicles in ultrathin sections of vulnerable and stable plaques revealed that the numbers of matrix vesicles were significantly higher in fibrous caps of vulnerable plaques than those in stable plaques (8.908+0.544 versus 6.208+0.467 matrix vesicles per 1.92 microm2 standard area; P= 0.0002). Electron microscopy combined with X-ray elemental microanalysis showed that some matrix vesicles in atherosclerotic plaques were undergoing calcification and were characterized by a high content of calcium and phosphorus. The percentage of calcified matrix vesicles

Utility of magnetic resonance imaging-based finite element analysis for the biomechanical stress analysis of hemorrhagic and non-hemorrhagic carotid plaques

International Nuclear Information System (INIS)

Sadat, U.; Teng, Z.; Young, V.E.; Li, Z.Y.; Gillard, J.H.

2011-01-01

Biomechanical stress analysis has been used for plaque vulnerability assessment. The presence of plaque hemorrhage (PH) is a feature of plaque vulnerability and is associated with thromboembolic ischemic events. The purpose of the present study was to use finite element analysis (FEA) to compare the stress profiles of hemorrhagic and non-hemorrhagic profiles. Forty-five consecutive patients who had suffered a cerebrovascular ischemic event with an underlying carotid artery disease underwent high-resolution magnetic resonance imaging (MRI) of their symptomatic carotid artery in a 1.5-T MRI system. Axial images were manually segmented for various plaque components and used for FEA. Maximum critical stress (M-Cstress SL ) for each slice was determined. Within a plaque, the maximum M-Cstress SL for each slice of a plaque was selected to represent the maximum critical stress of that plaque (M-Cstress PL ) and used to compare hemorrhagic and non-hemorrhagic plaques. A total of 62% of plaques had hemorrhage. It was observed that plaques with hemorrhage had significantly higher stress (M-Cstress PL ) than plaques without PH (median [interquartile range]: 315kPa [247-434] vs. 200kPa [171-282], P=0.003). Hemorrhagic plaques have higher biomechanical stresses than non-hemorrhagic plaques. MRI-based FEA seems to have the potential to assess plaque vulnerability. (author)

Intraplaque Hemorrhage and the Plaque Surface in Carotid Atherosclerosis: The Plaque At RISK Study (PARISK)

NARCIS (Netherlands)

van Dijk, A. C.; Truijman, M. T. B.; Hussain, B.; Zadi, T.; Saiedie, G.; de Rotte, A. A. J.; Liem, M. I.; van der Steen, A. F. W.; Daemen, M. J. A. P.; Koudstaal, P. J.; Nederkoorn, P. J.; Hendrikse, J.; Kooi, M. E.; van der Lugt, A.

2015-01-01

An important characteristic of vulnerable plaque, intraplaque hemorrhage, may predict plaque rupture. Plaque rupture can be visible on noninvasive imaging as a disruption of the plaque surface. We investigated the association between intraplaque hemorrhage and disruption of the plaque surface. We

Kyrieleis plaques associated with Herpes Simplex Virus type 1 acute retinal necrosis

Directory of Open Access Journals (Sweden)

Neha Goel

2016-04-01

Full Text Available We report the case of a 55-year-old immunocompetent male who presented with features typical of acute retinal necrosis (ARN. Polymerase chain reaction of the aqueous tap was positive for Herpes Simplex Virus (HSV – 1. Following therapy with intravenous Acyclovir, followed by oral Acyclovir and steroids, there was marked improvement in the visual acuity and clinical picture. At one week after initiation of treatment, Kyrieleis plaques were observed in the retinal arteries. They became more prominent despite resolution of the vitritis, retinal necrosis and vasculitis and persisted till six weeks of follow-up, when fluorescein angiography was performed. The appearance of this segmental retinal periarteritis also known as Kyrieleis plaques has not been described in ARN due to HSV-1 earlier.

Prevalence of noncalcified coronary plaque in patients with calcium score of 0: the silent enemy.

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Koulaouzidis, George; Charisopoulou, Dafni; Jenkins, Paul J; Koulaouzidis, Anastasios; McArthur, Tony

2013-04-01

Noncalcified coronary artery plaques (NCAPs) are susceptible to rupture, resulting in coronary artery thrombosis. Using computer tomography coronary angiography (CTCA), we evaluated the prevalence and degree of stenosis caused by NCAP in patients without coronary artery calcification (CAC). A retrospective analysis of 447 symptomatic patients with 0 CAC score revealed negative CTCA in 400 (89.5%). Noncalcified coronary artery plaques were demonstrated in 47 (10.5%), with 4 presenting stenosis >50%. Patients with positive CTCA, compared to those with normal CTCA, had significantly higher mean age (56.2 years vs 50.6 years, P < .004) and higher pretest coronary artery disease (CAD) probability (26% vs 34%, P < .0001). Noncalcified coronary artery plaque was predominantly developed in the proximal segment of the left anterior descending artery. Noncalcified coronary artery plaque is present in up to 10% of patients with a CAC score of 0. Computer tomography coronary angiography could be of diagnostic value in symptomatic patients with multiple risk factors for CAD, even in the absence of CAC.

Feasibility of Vascular Endothelial Growth Factor Imaging in Human Atherosclerotic Plaque Using 89Zr-Bevacizumab Positron Emission Tomography

Directory of Open Access Journals (Sweden)

Reza Golestani

2013-06-01

Full Text Available Intraplaque angiogenesis is associated with the occurrence of atherosclerotic plaque rupture. Cardiovascular molecular imaging can be used for the detection of rupture-prone plaques. Imaging with radiolabeled bevacizumab, a monoclonal anti-vascular endothelial growth factor (VEGF-A, can depict VEGF levels corresponding to the angiogenic status in tumors. We determined the feasibility of 89Zr-bevacizumab imaging for the detection of VEGF in carotid endarterectomy (CEA specimens. Five CEA specimens were coincubated with 89Zr-bevacizumab and aspecific 111In-labeled IgG to determine the specificity of bevacizumab accumulation. In 11 CEA specimens, 89Zr-bevacizumab micro-positron emission tomography (PET was performed following 2 hours of incubation. Specimens were cut in 4 mm wide segments and were stained for VEGF and CD68. In each segment, the mean percent incubation dose per gram of tissue (%Inc/g and tissue to background ratio were determined. A 10-fold higher accumulation of 89Zr-bevacizumab compared to 111In-IgG uptake was demonstrated by gamma counting. The mean %Inc/ghot spot was 2.2 ± 0.9 with a hot spot to background ratio of 3.6 ± 0.8. There was a significant correlation between the segmental tissue to background uptake ratio and the VEGF score (ρ = .74, p < .001. It is feasible to detect VEGF tissue concentration within CEA specimens using 89Zr-bevacizumab PET. 89Zr-bevacizumab accumulation in plaques is specific and correlates with immunohistochemistry scores.

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

Science.gov (United States)

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

2005-04-01

Intravascular ultrasound (IVUS) elastography visualizes local radial strain of arteries in so-called elastograms to detect rupture-prone plaques. However, due to the unknown arterial stress distribution these elastograms cannot be directly interpreted as a morphology and material composition image. To overcome this limitation we have developed a method that reconstructs a Young's modulus image from an elastogram. This method is especially suited for thin-cap fibroatheromas (TCFAs), i.e., plaques with a media region containing a lipid pool covered by a cap. Reconstruction is done by a minimization algorithm that matches the strain image output, calculated with a parametric finite element model (PFEM) representation of a TCFA, to an elastogram by iteratively updating the PFEM geometry and material parameters. These geometry parameters delineate the TCFA media, lipid pool and cap regions by circles. The material parameter for each region is a Young's modulus, EM, EL, and EC, respectively. The method was successfully tested on computer-simulated TCFAs (n = 2), one defined by circles, the other by tracing TCFA histology, and additionally on a physical phantom (n = 1) having a stiff wall (measured EM = 16.8 kPa) with an eccentric soft region (measured EL = 4.2 kPa). Finally, it was applied on human coronary plaques in vitro (n = 1) and in vivo (n = 1). The corresponding simulated and measured elastograms of these plaques showed radial strain values from 0% up to 2% at a pressure differential of 20, 20, 1, 20, and 1 mmHg respectively. The used/reconstructed Young's moduli [kPa] were for the circular plaque EL = 50/66, EM = 1500/1484, EC = 2000/2047, for the traced plaque EL = 25/1, EM = 1000/1148, EC = 1500/1491, for the phantom EL = 4.2/4 kPa, EM = 16.8/16, for the in vitro plaque EL = n.a./29, EM = n.a./647, EC = n.a./1784 kPa and for the in vivo plaque EL = n.a./2, EM = n.a./188, Ec = n.a./188 kPa.

Prognostic implications of nonobstructive coronary plaques in patients with non-ST-segment elevation myocardial infarction: a multidetector computed tomography study

DEFF Research Database (Denmark)

Kristensen, Thomas S; Kofoed, Klaus F; Kühl, Jørgen T

2011-01-01

We sought to determine whether the amount of noncalcified plaque (NCP) in nonobstructive coronary lesions as detected by multidetector computed tomography (MDCT) was a predictor of future coronary events.......We sought to determine whether the amount of noncalcified plaque (NCP) in nonobstructive coronary lesions as detected by multidetector computed tomography (MDCT) was a predictor of future coronary events....

Usefulness of Coronary Atheroma Burden to Predict Cardiovascular Events in Patients Presenting With Acute Coronary Syndromes (from the PROSPECT Study).

Science.gov (United States)

Shan, Peiren; Mintz, Gary S; McPherson, John A; De Bruyne, Bernard; Farhat, Naim Z; Marso, Steven P; Serruys, Patrick W; Stone, Gregg W; Maehara, Akiko

2015-12-01

We investigated the relation between overall atheroma burden and clinical events in the Providing Regional Observations to Study Predictors of Events in the Coronary Tree (PROSPECT) study. In PROSPECT, 660 patients (3,229 nonculprit lesions with a plaque burden ≥ 40% and complete intravascular ultrasound data) were divided into tertiles according to baseline percent atheroma volume (PAV: total plaque/vessel volume). Patients were followed for 3.4 years (median); major adverse cardiac events (MACE: death from cardiac causes, cardiac arrest, myocardial infarction, or rehospitalization because of unstable or progressive angina) were adjudicated to either culprit or nonculprit lesions. Compared with patients in low or intermediate PAV tertiles, patients in the high PAV tertile had the greatest prevalence of plaque rupture and radiofrequency thin-cap fibroatheroma (VH-TCFA) and the highest percentage of necrotic core volume; they were also more likely to have high-risk lesion characteristics: ≥ 1 lesion with minimal luminal area ≤ 4 mm(2), plaque burden >70%, and/or VH-TCFA. Three-year cumulative nonculprit lesion-related MACE was greater in the intermediate and high tertiles than in the low tertile (6.3% vs 14.7% vs 15.1%, low vs intermediate vs high tertiles, p = 0.009). On Cox multivariable analysis, insulin-dependent diabetes (hazard ratio [HR] 3.98, p = 0.002), PAV (HR 1.06, p = 0.03), and the presence of ≥1 VH-TCFA (HR 1.80, p = 0.02) were independent predictors of nonculprit MACE. In conclusion, increasing baseline overall atheroma burden was associated with more advanced, complex, and vulnerable intravascular ultrasound lesion morphology and independently predicted nonculprit lesion-related MACE in patients with acute coronary syndromes after successful culprit lesion intervention. Copyright © 2015 Elsevier Inc. All rights reserved.

Carotid plaque age is a feature of plaque stability inversely related to levels of plasma insulin.

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Sara Hägg

Full Text Available 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.

Combined presence of aortic valve calcification and mitral annular calcification as a marker of the extent and vulnerable characteristics of coronary artery plaque assessed by 64-multidetector computed tomography.

Science.gov (United States)

Utsunomiya, Hiroto; Yamamoto, Hideya; Kunita, Eiji; Kitagawa, Toshiro; Ohashi, Norihiko; Oka, Toshiharu; Yamazato, Ryo; Horiguchi, Jun; Kihara, Yasuki

2010-11-01

We examined the association of aortic valve calcification (AVC) and mitral annular calcification (MAC) to coronary atherosclerosis using 64-multidetector computed tomography (MDCT). Valvular calcification is considered a manifestation of atherosclerosis. The impact of multiple heart valve calcium deposits on the distribution and characteristics of coronary plaque is unknown. We evaluated 322 patients referred for 64-MDCT, and assessed valvular calcification and the extent of calcified (CAP), mixed (MCAP), and noncalcified coronary atherosclerotic plaque (NCAP) in accordance with the 17-coronary segments model. We assessed the vulnerable characteristics of coronary plaque with positive remodeling, low-density plaque (CT density ≤38 Hounsfield units), and the presence of adjacent spotty calcification. In 49 patients with both AVC and MAC, the segment numbers of CAP and MCAP were larger than in those with a lack of valvular calcification and an isolated AVC (pNCAP. Moreover, it was also related to the presence of coronary plaque with all three vulnerable characteristics (OR 4.87, 95%CI 1.85-12.83, p=0.001). The combined presence of AVC and MAC is highly associated with the presence, extent, and vulnerable characteristics of coronary plaque identified by 64-MDCT. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Cystatin C–Adiponectin Complex in Plasma Associates with Coronary Plaque Instability

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Matsuoka, Tetsuro; Kayama, Kento; Onishi, Sumire; Matsuo, Natsumi

2017-01-01

Aim: Adiponectin (APN) is an adipocyte-derived bioactive molecule with antiatherogenic properties. We previously reported that cystatin C (CysC) abolished the anti-atherogenic effects of APN. We aimed to elucidate the clinical significance of CysC–APN complex in patients with coronary artery disease (CAD). Methods: We enrolled 43 stable CAD male patients to examine the relationship between CysC–APN complex and coronary plaque characteristics. Serum was immunoprecipitated by the anti-APN antibody and immunoblotted by the anti-CysC antibody to demonstrate the presence of CysC–APN complexes in vivo. To confirm their binding in vitro, HEK293T cell lysates overexpressing myc-APN and FLAG-CysC were immunoprecipitated with an anti-myc or anti-FLAG antibody, followed by immunoblotting with an anti-APN or anti-CysC antibody. Results: CysC was identified as a specific co-immunoprecipitant with APN by the anti-APN antibody in human serum. In vitro, FLAG-CysC was co-immunoprecipitated with myc-APN by the antimyc antibody and myc-APN was co-immunoprecipitated with FLAG-CysC by the anti-FLAG antibody. Among CAD patients, serum CysC–APN complex levels negatively correlated with fibrotic components of coronary plaques and positively correlated with either necrotic or lipidic plus necrotic components. Plaque burden negatively correlated with serum APN levels but not serum CysC–APN complex levels. Serum CysC levels had no association with plaque characteristics. In multivariate analysis, CysC–APN complex levels were identified as the strongest negative factor for fibrotic components and the strongest positive factor for both necrotic and lipidic plus necrotic components. Conclusion: Measuring serum CysC–APN complex levels is helpful for evaluating coronary plaque instability in CAD patients. PMID:28321013

A new inexpensive customized plaque for choroidal melanoma iodine-125 plaque therapy

International Nuclear Information System (INIS)

Vine, A.K.; Tenhaken, R.K.; Diaz, R.F.; Maxson, B.B.; Lichter, A.S.

1989-01-01

The authors have developed a new inexpensive precious metal alloy plaque for use in customized iodine-125 plaque therapy. Each plaque is formed from two flat circular gold/palladium foils which are used in dental crown work. Using a simple manual mechanism, the two forms are stamped over a customized acrylic die shaped to the dimensions of the tumor base plus a 2-mm margin. Completed plaques consist of a back wall, a 2-mm side wall, and a 1.5-mm wide lip with holes for suture placement. Advantages include: simple construction from inexpensive components, customized shape, and iodine seeds that are readily visible on plane radiographs

Learning-based automated segmentation of the carotid artery vessel wall in dual-sequence MRI using subdivision surface fitting.

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Gao, Shan; van 't Klooster, Ronald; Kitslaar, Pieter H; Coolen, Bram F; van den Berg, Alexandra M; Smits, Loek P; Shahzad, Rahil; Shamonin, Denis P; de Koning, Patrick J H; Nederveen, Aart J; van der Geest, Rob J

2017-10-01

The quantification of vessel wall morphology and plaque burden requires vessel segmentation, which is generally performed by manual delineations. The purpose of our work is to develop and evaluate a new 3D model-based approach for carotid artery wall segmentation from dual-sequence MRI. The proposed method segments the lumen and outer wall surfaces including the bifurcation region by fitting a subdivision surface constructed hierarchical-tree model to the image data. In particular, a hybrid segmentation which combines deformable model fitting with boundary classification was applied to extract the lumen surface. The 3D model ensures the correct shape and topology of the carotid artery, while the boundary classification uses combined image information of 3D TOF-MRA and 3D BB-MRI to promote accurate delineation of the lumen boundaries. The proposed algorithm was validated on 25 subjects (48 arteries) including both healthy volunteers and atherosclerotic patients with 30% to 70% carotid stenosis. For both lumen and outer wall border detection, our result shows good agreement between manually and automatically determined contours, with contour-to-contour distance less than 1 pixel as well as Dice overlap greater than 0.87 at all different carotid artery sections. The presented 3D segmentation technique has demonstrated the capability of providing vessel wall delineation for 3D carotid MRI data with high accuracy and limited user interaction. This brings benefits to large-scale patient studies for assessing the effect of pharmacological treatment of atherosclerosis by reducing image analysis time and bias between human observers. © 2017 American Association of Physicists in Medicine.

[18F]Fluoroazabenzoxazoles as potential amyloid plaque PET tracers: synthesis and in vivo evaluation in rhesus monkey

International Nuclear Information System (INIS)

Hostetler, Eric D.; Sanabria-Bohórquez, Sandra; Fan Hong; Zeng, Zhizhen; Gammage, Linda; Miller, Patricia; O'Malley, Stacey; Connolly, Brett; Mulhearn, James; Harrison, Scott T.; Wolkenberg, Scott E.; Barrow, James C.; Williams, David L.; Hargreaves, Richard J.; Sur, Cyrille; Cook, Jacquelynn J.

2011-01-01

Introduction: An 18 F-labeled positron emission tomography (PET) tracer for amyloid plaque is desirable for early diagnosis of Alzheimer's disease, particularly to enable preventative treatment once effective therapeutics are available. Similarly, such a tracer would be useful as a biomarker for enrollment of patients in clinical trials for evaluation of antiamyloid therapeutics. Furthermore, changes in the level of plaque burden as quantified by an amyloid plaque PET tracer may provide valuable insights into the effectiveness of amyloid-targeted therapeutics. This work describes our approach to evaluate and select a candidate PET tracer for in vivo quantification of human amyloid plaque. Methods: Ligands were evaluated for their in vitro binding to human amyloid plaques, lipophilicity and predicted blood–brain barrier permeability. Candidates with favorable in vitro properties were radiolabeled with 18 F and evaluated in vivo. Baseline PET scans in rhesus monkey were conducted to evaluate the regional distribution and kinetics of each tracer using tracer kinetic modeling methods. High binding potential in cerebral white matter and cortical grey matter was considered an unfavorable feature of the candidate tracers. Results: [ 18 F]MK-3328 showed the most favorable combination of low in vivo binding potential in white matter and cortical grey matter in rhesus monkeys, low lipophilicity (Log D=2.91) and high affinity for human amyloid plaques (IC 50 =10.5±1.3 nM). Conclusions: [ 18 F]MK-3328 was identified as a promising PET tracer for in vivo quantification of amyloid plaques, and further evaluation in humans is warranted.

Multidetector row computed tomography may accurately estimate plaque vulnerability. Does MDCT accurately estimate plaque vulnerability? (Pro)

International Nuclear Information System (INIS)

Komatsu, Sei; Imai, Atsuko; Kodama, Kazuhisa

2011-01-01

Over the past decade, multidetector row computed tomography (MDCT) has become the most reliable and established of the noninvasive examination techniques for detecting coronary heart disease. Now MDCT is chasing intravascular ultrasound (IVUS) in terms of spatial resolution. Among the components of vulnerable plaque, MDCT may detect lipid-rich plaque, the lipid pool, and calcified spots using computed tomography number. Plaque components are detected by MDCT with high accuracy compared with IVUS and angioscopy when assessing vulnerable plaque. The TWINS study and TOGETHAR trial demonstrated that angioscopic loss of yellow color occurred independently of volumetric plaque change by statin therapy. These 2 studies showed that plaque stabilization and regression reflect independent processes mediated by different mechanisms and time course. Noncalcified plaque and/or low-density plaque was found to be the strongest predictor of cardiac events, regardless of lesion severity, and act as a potential marker of plaque vulnerability. MDCT may be an effective tool for early triage of patients with chest pain who have a normal electrocardiogram (ECG) and cardiac enzymes in the emergency department. MDCT has the potential ability to analyze coronary plaque quantitatively and qualitatively if some problems are resolved. MDCT may become an essential tool for detecting and preventing coronary artery disease in the future. (author)

Helicobacter pylori in dental plaque; is it related to brushing frequency, plaque load and oral health status?

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Chaudhry, Saima; Khan, Ayyaz Ali; Butt, Arshad Kamal; Idrees, Muhammad; Izhar, Mateen; Iqbal, Hafiz Aamer

2011-10-01

To determine the relation between presence of H. pylori in supra-gingival dental plaque with oral hygiene habits and oral health status of patients suffering from symptomatic dyspepsia. Descriptive study. The Department of Oral Health Sciences, Shaikh Zayed FPGMI, Lahore, from September 2008 to August 2009. One hundred and fifty dyspeptic subjects with dental plaque were enrolled. After recording brushing frequency, oral health status and plaque load, the supra-gingival dental plaque samples were collected by sterile curettes. Helicobacter pylori were detected in dental plaque samples through PCR assay. Presence of H. pylori in dental plaque was found to be 37.5% in the sample. Most of the subjects brushed once daily, had plaque index score of 1 and had fair to poor oral hygiene status. Approximately 35% of the individuals who brushed once or twice a day harbored the bacterium in their dental plaque. There was no difference between bacterial detection rates among different categories of plaque index and oral health status of the study subjects. Presence of H. pylori in dental plaque was found to be associated with neither brushing frequency nor with the plaque load nor with the oral health status of individuals suffering from symptomatic dyspepsia.

Noninvasive characterization of carotid plaque strain.

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Khan, Amir A; Sikdar, Siddhartha; Hatsukami, Thomas; Cebral, Juan; Jones, Michael; Huston, John; Howard, George; Lal, Brajesh K

2017-06-01

Current risk stratification of internal carotid artery plaques based on diameter-reducing percentage stenosis may be unreliable because ischemic stroke results from plaque disruption with atheroembolization. Biomechanical forces acting on the plaque may render it vulnerable to rupture. The feasibility of ultrasound-based quantification of plaque displacement and strain induced by hemodynamic forces and their relationship to high-risk plaques have not been determined. We studied the feasibility and reliability of carotid plaque strain measurement from clinical B-mode ultrasound images and the relationship of strain to high-risk plaque morphology. We analyzed carotid ultrasound B-mode cine loops obtained in patients with asymptomatic ≥50% stenosis during routine clinical scanning. Optical flow methods were used to quantify plaque motion and shear strain during the cardiac cycle. The magnitude (maximum absolute shear strain rate [MASSR]) and variability (entropy of shear strain rate [ESSR] and variance of shear strain rate [VSSR]) of strain were combined into a composite shear strain index (SSI), which was assessed for interscan repeatability and correlated with plaque echolucency. Nineteen patients (mean age, 70 years) constituting 36 plaques underwent imaging; 37% of patients (n = 7) showed high strain (SSI ≥0.5; MASSR, 2.2; ESSR, 39.7; VSSR, 0.03) in their plaques; the remaining clustered into a low-strain group (SSI routine B-mode imaging using clinical ultrasound machines. High plaque strain correlates with known high-risk echolucent morphology. Strain measurement can complement identification of patients at high risk for plaque disruption and stroke. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Quantification of atherosclerotic plaque activity and vascular inflammation using [18-F] fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT).

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Mehta, Nehal N; Torigian, Drew A; Gelfand, Joel M; Saboury, Babak; Alavi, Abass

2012-05-02

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC) and carotid intimal medial thickness (C-IMT) provide information about the burden of disease. However, despite multiple validation studies of CAC, and C-IMT, these modalities do not accurately assess plaque characteristics, and the composition and inflammatory state of the plaque determine its stability and, therefore, the risk of clinical events. [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG) imaging using positron-emission tomography (PET)/computed tomography (CT) has been extensively studied in oncologic metabolism. Studies using animal models and immunohistochemistry in humans show that FDG-PET/CT is exquisitely sensitive for detecting macrophage activity, an important source of cellular inflammation in vessel walls. More recently, we and others have shown that FDG-PET/CT enables highly precise, novel measurements of inflammatory activity of activity of atherosclerotic plaques in large and medium-sized arteries. FDG-PET/CT studies have many advantages over other imaging modalities: 1) high contrast resolution; 2) quantification of plaque volume and metabolic activity allowing for multi-modal atherosclerotic plaque quantification; 3) dynamic, real-time, in vivo imaging; 4) minimal operator dependence. Finally, vascular inflammation detected by FDG-PET/CT has been shown to predict cardiovascular (CV) events independent of traditional risk factors and is also highly associated with overall burden of atherosclerosis. Plaque activity by FDG-PET/CT is modulated by known beneficial CV interventions such as short term (12 week) statin therapy as well as longer term therapeutic lifestyle changes (16 months). The current methodology for quantification of FDG uptake in atherosclerotic plaque involves measurement of the standardized uptake value (SUV) of an artery of interest and of the venous blood pool in order to calculate a target to background ratio (TBR), which is

Plaque control and oral hygiene methods

LENUS (Irish Health Repository)

Harrison, Peter

2017-06-01

The experimental gingivitis study of Löe et al.1 demonstrated a cause and effect relationship between plaque accumulation and gingival inflammation, and helped to establish plaque\\/biofilm as the primary risk factor for gingivitis. When healthy individuals withdrew oral hygiene efforts, gingival inflammation ensued within 21 days in all subjects. Once effective plaque removal was recommenced, clinical gingival health was quickly re-established – indicating that plaque-associated inflammation is modifiable by plaque control. As current consensus confirms that gingivitis and periodontitis may be viewed as a continuum of disease,2 the rationale for achieving effective plaque control is clear.

Coronary Plaque Characteristics Assessed by 256-Slice Coronary CT Angiography and Association with High-Sensitivity C-Reactive Protein in Symptomatic Patients with Type 2 Diabetes

Directory of Open Access Journals (Sweden)

Jinling Zhang

2016-01-01

Full Text Available Little is known regarding plaque distribution, composition, and the association with inflammation in type 2 diabetes mellitus (DM2. This study aimed to assess the relationship between coronary plaque subtypes and high-sensitivity C-reactive protein levels. Coronary CTA were performed in 98 symptomatic DM2 patients and 107 non-DM2 patients using a 256-slice CT. The extent and types of plaque as well as luminal narrowing were evaluated. Patients with DM2 were more likely to have significant stenosis (>50% with calcified plaques in at least one coronary segment (p<0.01; the prevalence rates of diffuse calcified plaques in the DM2 and non-DM2 groups were 31.6% and 4.7%, respectively (p<0.01. Plasma hs-CRP levels in DM2 with calcified plaques were higher compared with values obtained for the non-DM2 group (p<0.01. In conclusion, combination of coronary CTA and hs-CRP might improve risk stratification in symptomatic DM2 patients.

Clinical value of MSCTA in the interventional treatment of the initial origin stenotic segment of the internal carotid artery

International Nuclear Information System (INIS)

Qi Yueyong; Zou Liguang; Chen Lin; Sun Qingrong; Shuai Jie; Zhou Zheng; Huang Lan

2007-01-01

Objective: To assess the clinical value of MSCTA in the interventional treatment of the initial origin stenotic segment of internal carotid artery. Methods: Forty two patients with stenosis of initial origin stenotic segment of internal carotid artery underwent interventional treatment and MSCTA were analyzed retrospectively. Results: Forty two patients were diagnosed correctly through MSCTA. The percentages of stenotic area were measured from the multiplanar reconstruction (MPR)images of MSCTA, including mild stenosis( 70%)in 30, obstruction in 4 (>100%)and normal in 18. Plaques and endoscopic views of stenosis were delineated on MSCTA and CTVE. Conclusion: MSCTA is an accurate method for the assessment of the stenosis and plaques of the stenotic origin segment of internal carotid artery. MSCTA can be used as a convenient follow-up modality for instent restenosis. (authors)

Denture plaque--past and recent concerns.

Science.gov (United States)

Nikawa, H; Hamada, T; Yamamoto, T

1998-05-01

This paper critically reviews the history of denture plaque and identifies some concerns with the presence of Candida in the mouth. This review covers literature sources related to Candida albicans and its relationship to denture plaque. The articles selected for this review are from referred journals and describe C. albicans and its relationship to oral, gastrointestinal and pleuropulmonary infections. The relationship to caries, root caries and periodontal disease is also covered. Denture plaque containing Candida could cause not only oral candidiasis, like oral thrush or denture-induced stomatitis, but also caries, root caries and periodontitis of abutment teeth. However, there is only limited experimental evidence or information available on the cariogenicity of Candida. The continuous swallowing or aspiration of micro-organisms from denture plaque exposes patients, particularly the immunocompromised host or medicated elderly, to the risks of unexpected infections. The term, 'denture plaque' has been used throughout the review. However, the term 'plaque on denture' should be used because the microbial flora and its pathogenicity of denture plaque resembles those of plaque formed on the tooth surface, so called dental plaque. In addition, the term 'denture related stomatitis' would be preferable to 'denture induced stomatitis', since the inflammation of (palatal) mucosa is not induced by the denture, but by wearing the denture or by plaque on the denture.

Automatic segmentation and 3D reconstruction of intravascular ultrasound images for a fast preliminar evaluation of vessel pathologies.

Science.gov (United States)

Sanz-Requena, Roberto; Moratal, David; García-Sánchez, Diego Ramón; Bodí, Vicente; Rieta, José Joaquín; Sanchis, Juan Manuel

2007-03-01

Intravascular ultrasound (IVUS) imaging is used along with X-ray coronary angiography to detect vessel pathologies. Manual analysis of IVUS images is slow and time-consuming and it is not feasible for clinical purposes. A semi-automated method is proposed to generate 3D reconstructions from IVUS video sequences, so that a fast diagnose can be easily done, quantifying plaque length and severity as well as plaque volume of the vessels under study. The methodology described in this work has four steps: a pre-processing of IVUS images, a segmentation of media-adventitia contour, a detection of intima and plaque and a 3D reconstruction of the vessel. Preprocessing is intended to remove noise from the images without blurring the edges. Segmentation of media-adventitia contour is achieved using active contours (snakes). In particular, we use the gradient vector flow (GVF) as external force for the snakes. The detection of lumen border is obtained taking into account gray-level information of the inner part of the previously detected contours. A knowledge-based approach is used to determine which level of gray corresponds statistically to the different regions of interest: intima, plaque and lumen. The catheter region is automatically discarded. An estimate of plaque type is also given. Finally, 3D reconstruction of all detected regions is made. The suitability of this methodology has been verified for the analysis and visualization of plaque length, stenosis severity, automatic detection of the most problematic regions, calculus of plaque volumes and a preliminary estimation of plaque type obtaining for automatic measures of lumen and vessel area an average error smaller than 1mm(2) (equivalent aproximately to 10% of the average measure), for calculus of plaque and lumen volume errors smaller than 0.5mm(3) (equivalent approximately to 20% of the average measure) and for plaque type estimates a mismatch of less than 8% in the analysed frames.

A comparison between plaque-based and vessel-based measurement for plaque component using volumetric intravascular ultrasound radiofrequency data analysis.

Science.gov (United States)

Shin, Eun-Seok; Garcia-Garcia, Hector M; Garg, Scot; Serruys, Patrick W

2011-04-01

Although percent plaque components on plaque-based measurement have been used traditionally in previous studies, the impact of vessel-based measurement for percent plaque components have yet to be studied. The purpose of this study was therefore to correlate percent plaque components derived by plaque- and vessel-based measurement using intravascular ultrasound virtual histology (IVUS-VH). The patient cohort comprised of 206 patients with de novo coronary artery lesions who were imaged with IVUS-VH. Age ranged from 35 to 88 years old, and 124 patients were male. Whole pullback analysis was used to calculate plaque volume, vessel volume, and absolute and percent volumes of fibrous, fibrofatty, necrotic core, and dense calcium. The plaque and vessel volumes were well correlated (r = 0.893, P measurement was also highly correlated with vessel-based measurement. Therefore, the percent plaque component volume calculated by vessel volume could be used instead of the conventional percent plaque component volume calculated by plaque volume.

Relation between thoracic aortic inflammation and features of plaque vulnerability in the coronary tree in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention. An FDG-positron emission tomography and optical coherence tomography study

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Taglieri, Nevio; Ghetti, Gabriele; Saia, Francesco; Bacchi Reggiani, Maria Letizia; Rapezzi, Claudio [Alma Mater Studiorum Universita di Bologna, Istituto di Cardiologia, Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Bologna (Italy); Nanni, Cristina; Bonfiglioli, Rachele; Lima, Giacomo Maria; Fanti, Stefano [Alma Mater Studiorum Universita di Bologna, Istituto di Medicina Nucleare, Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Bologna (Italy); Marco, Valeria [CLI Foundation, Rome (Italy); Prati, Francesco [CLI Foundation, Rome (Italy); Ettore Sansavini Health Science Foundation, GVM Care and Research, Cotignola (Italy)

2017-10-15

To evaluate the relationship between aortic inflammation as assessed by {sup 18}F-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG-PET) and features of plaque vulnerability as assessed by frequency domain-optical coherence tomography (FD-OCT). We enrolled 30 consecutive non-ST-segment elevation acute coronary syndrome patients undergoing percutaneous coronary intervention. All patients underwent three-vessel OCT before intervention and {sup 18}F-FDG-PET before discharge. Univariable and C-reactive protein (CRP)-adjusted linear regression analyses were performed between features of vulnerability [namely:lipid-rich plaques with and without macrophages and thin cap fibroatheromas (TCFA)] and {sup 18}F-FDG uptake in both ascending (AA) and descending aorta (DA) [measured either as averaged mean and maximum target-to-blood ratio (TBR) or as active slices (TBR{sub max} ≥ 1.6)]. Mean age was 62 years, and 26 patients were male. On univariable linear regression analysis TBR{sub mean} and TBR{sub max} in DA was associated with the number of lipid-rich plaques (β = 4.22; 95%CI 0.05-8.39; p = 0.047 and β = 3.72; 95%CI 1.14-6.30; p = 0.006, respectively). TBR{sub max} in DA was also associated with the number of lipid-rich plaques containing macrophages (β = 2.40; 95%CI 0.07-4.72; p = 0.044). A significant CRP adjusted linear association between the TBR{sub max} in DA and the number of lipid-rich plaques was observed (CRP-adjusted β = 3.58; 95%CI -0.91-6.25; p = 0.01). TBR{sub max} in DA showed a trend towards significant CRP-adjusted association with number of lipid-rich plaques with macrophages (CRP-adjusted β = 2.30; 95%CI -0.11-4.71; p = 0.06). We also observed a CRP-adjusted (β = 2.34; 95%CI 0.22-4.47; p = 0.031) linear association between the number of active slices in DA and the number of lipid-rich plaques. No relation was found between FDG uptake in the aorta and the number of TCFAs. In patients with first NSTEACS{sup ,} {sup 18}F-FDG uptake in

Neutrophil to lymphocyte ratio is associated with proximal/middle segment of the LAD lesions in patients with ST segment elevation infarction

Directory of Open Access Journals (Sweden)

Ozlem Arican Ozluk

2017-01-01

Full Text Available Introduction: Neutrophil to lymphocyte ratio (NLR was revaled to have a close relation with atherosclerotic cardiovascular disease. The relationship between NLR and culprit plaque localization has never been studied. Aim of the study : To evaluate the association between NLR and unstable plaque localization of left anterior descending artery (LAD in anterior miyocardial infarction patients. Material and methods : Patients admitted to our hospital with acute anterior STEMI were included. Fifhy-eight patients who have single-vessel disease at LAD and their hematological parameters were analyzed retrospectively. Proximal segment of LAD lesions were groupped as Group I and mid segment of the LAD lesion groupped as Group II. The groups were compared according to their NLR and other parameters. Results : Between group I (n = 41, mean age 52.5 ±12.7 and group II (n = 17, mean ages 52.0 ±10.8; NLR, were significantly higher in group I compared to the group II (6.9 ±5.6 vs. 3.3 ±2.0, p = 0.01. In group I, left ventricular ejection fraction (LVEF was significantly lower (p = 0.02. In correlation analyzes, NLR was positively correlated with CK MB (r = 0.32, p = 0.01 and negatively correlated with LVEF (r = –0.28, p = 0.03. Conclusions : The present study demonstrated that anterior myocardial infarction patients with high NLR had a greater possibility having proximal culprit lesion on the LAD. Therefore NLR can be used as a useful tool to culprit plaque localization in patients with acute miyocardial infarction patients.

Current status of vulnerable plaque detection.

LENUS (Irish Health Repository)

Sharif, Faisal

2012-02-01

Critical coronary stenoses have been shown to contribute to only a minority of acute coronary syndromes (ACS) 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 noninvasive imaging techniques have shown the potential to identify these high-risk plaques. The anatomical characteristics of the vulnerable plaque such as thin cap fibroatheroma and lipid pool can be identified with angioscopy, high frequency intravascular ultrasound, intravascular MRI, and optical coherence tomography. Efforts have also been made to recognize active inflammation in high-risk plaques using intravascular thermography. Plaque chemical composition by measuring electromagnetic radiation using spectroscopy is also an emerging technology to detect vulnerable plaques. Noninvasive imaging with MRI, CT, and PET also holds the potential to differentiate between low and high-risk plaques. However, at present none of these imaging modalities are able to detect vulnerable plaque neither has been shown to definitively predict outcome. Nevertheless in contrast, there has been a parallel development in the physiological assessment of advanced atherosclerotic coronary artery disease. Thus recent trials using fractional flow reserve in patients with modest non flow-limiting stenoses have shown that deferral of PCI with optimal medical therapy in these patients is superior to coronary intervention. 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.

The inter-observer agreement in the assessment of carotid plaque neovascularization by contrast-enhanced ultrasonography: The impact of plaque thickness.

Science.gov (United States)

Chen, Jian; Zhang, Yan-Ming; Song, Ze-Zhou; Fu, Yan-Fei; Geng, Yu

2018-04-10

The interobserver agreement in the assessment of the grade of carotid plaque neovascularization by contrast-enhanced ultrasonography is poorly established. We examined 140 carotid plaques in 66 patients (all patients had bilateral plaques, and 8 patients had 2 plaques on one side). We performed conventional and contrast-enhanced ultrasonography to analyze the presence of carotid plaque neovascularization, which was graded by two independent observers whose interobserver agreement (κ) was evaluated according to the thickness of carotid plaque. For all carotid plaques, the mean κ was 0.689 (95% confidence interval 0.604-0.774). It was 0.689 (0.569-0.808), 0.637 (0.487-0.787), and 0.740 (0.585-0.896), respectively for carotid plaques with maximal thickness 3 mm. The interobserver agreement for assessing carotid plaque neovascularization by using contrast-enhanced ultrasonography is substantial and acceptable for research purposes, regardless of the maximal thickness of the plaque. © 2018 Wiley Periodicals, Inc.

The association of lesion eccentricity with plaque morphology and components in the superficial femoral artery: a high-spatial-resolution, multi-contrast weighted CMR study

Directory of Open Access Journals (Sweden)

Zhao Xihai

2010-07-01

Full Text Available Abstract Background Atherosclerotic plaque morphology and components are predictors of subsequent cardiovascular events. However, associations of plaque eccentricity with plaque morphology and plaque composition are unclear. This study investigated associations of plaque eccentricity with plaque components and morphology in the proximal superficial femoral artery using cardiovascular magnetic resonance (CMR. Methods Twenty-eight subjects with an ankle-brachial index less than 1.00 were examined with 1.5T high-spatial-resolution, multi-contrast weighted CMR. One hundred and eighty diseased locations of the proximal superficial femoral artery (about 40 mm were analyzed. The eccentric lesion was defined as [(Maximum wall thickness- Minimum wall thickness/Maximum wall thickness] ≥ 0.5. The arterial morphology and plaque components were measured using semi-automatic image analysis software. Results One hundred and fifteen locations were identified as eccentric lesions and sixty-five as concentric lesions. The eccentric lesions had larger wall but similar lumen areas, larger mean and maximum wall thicknesses, and more calcification and lipid rich necrotic core, compared to concentric lesions. For lesions with the same lumen area, the degree of eccentricity was associated with an increased wall area. Eccentricity (dichotomous as eccentric or concentric was independently correlated with the prevalence of calcification (odds ratio 3.78, 95% CI 1.47-9.70 after adjustment for atherosclerotic risk factors and wall area. Conclusions Plaque eccentricity is associated with preserved lumen size and advanced plaque features such as larger plaque burden, more lipid content, and increased calcification in the superficial femoral artery.

Identifying Vulnerable Atherosclerotic Plaque in Rabbits Using DMSA-USPIO Enhanced Magnetic Resonance Imaging to Investigate the Effect of Atorvastatin

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Li, Dongye; Wu, Weiheng; Gong, Lei; Li, Yong; Zhang, Qingdui; Zhang, Tao; Zhang, Chao; Zhang, Yu

2015-01-01

Background Rupture of an atherosclerotic plaque is the primary cause of acute cardiovascular and cerebrovascular syndromes. Early and non-invasive detection of vulnerable atherosclerotic plaques (VP) would be significant in preventing some aspects of these syndromes. As a new contrast agent, dimercaptosuccinic acid (DMSA) modified ultra-small super paramagnetic iron oxide (USPIO) was synthesized and used to identify VP and rupture plaque by magnetic resonance imaging (MRI). Methods Atherosclerosis was induced in male New Zealand White rabbits by feeding a high cholesterol diet (n = 30). Group A with atherosclerosis plaque (n = 10) were controls. VP was established in groups B (n = 10) and C (n = 10) using balloon-induced endothelial injury of the abdominal aorta. Adenovirus-carrying p53 genes were injected into the aortic segments rich in plaques after 8 weeks. Group C was treated with atorvastatin for 8 weeks. Sixteen weeks later, all rabbits underwent pharmacological triggering, and imaging were taken daily for 5 d after DMSA-USPIO infusion. At the first day and before being killed, serum MMP-9, sCD40L, and other lipid indicators were measured. Results DMSA-USPIO particles accumulated in VP and rupture plaques. Rupture plaques appeared as areas of hyper-intensity on DMSA-USPIO enhanced MRI, especially T2*-weighted sequences, with a signal strength peaking at 96 h. The group given atorvastatin showed few DMSA-USPIO particles and had lower levels of serum indicators. MMP-9 and sCD40L levels in group B were significantly higher than in the other 2 groups (P MRI for clear identification of plaque inflammation and rupture. Rupture plaques were detectable in this way probably due to an activating inflammatory process. Atorvastatin reduced the inflammatory response and stabilizing VP possibly by decreasing MMP-9 and sCD40L levels. PMID:25973795

Kinetics of hemolytic plaque formation. IV. IgM plaque inhibition

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DeLisi, C

1975-01-01

An analysis of the inhibition of hemolytic plaques formed against IgM antibodies is presented. The starting point is the equations of DeLisi and Bell (1974) which describe the kinetics of plaque growth, and DeLisi and Goldstein (1975) which describe inhibition of IgG plaques. However, the physical chemical models which were used previously to describe IgG inhibition data are shown to be inadequate for describing the characteristics of IgM inhibition curves. Moreover, it is shown that the experimental results place severe restrictions on the possible choices of physical chemical models for IgM upon which to base the calculations. It is argued that in order to account even qualitatively for all the data, one must assume (1) a very restricted motion of IgMs about the Fab hinge region and (2) a very narrow secretion rate distribution of IgM by antibody secreting cells. (auth)

Accurate estimation of dose distributions inside an eye irradiated with 106Ru plaques

International Nuclear Information System (INIS)

Brualla, L.; Sauerwein, W.; Sempau, J.; Zaragoza, F.J.; Wittig, A.

2013-01-01

Background: Irradiation of intraocular tumors requires dedicated techniques, such as brachytherapy with 106 Ru plaques. The currently available treatment planning system relies on the assumption that the eye is a homogeneous water sphere and on simplified radiation transport physics. However, accurate dose distributions and their assessment demand better models for both the eye and the physics. Methods: The Monte Carlo code PENELOPE, conveniently adapted to simulate the beta decay of 106 Ru over 106 Rh into 106 Pd, was used to simulate radiation transport based on a computerized tomography scan of a patient's eye. A detailed geometrical description of two plaques (models CCA and CCB) from the manufacturer BEBIG was embedded in the computerized tomography scan. Results: The simulations were firstly validated by comparison with experimental results in a water phantom. Dose maps were computed for three plaque locations on the eyeball. From these maps, isodose curves and cumulative dose-volume histograms in the eye and for the structures at risk were assessed. For example, it was observed that a 4-mm anterior displacement with respect to a posterior placement of a CCA plaque for treating a posterior tumor would reduce from 40 to 0% the volume of the optic disc receiving more than 80 Gy. Such a small difference in anatomical position leads to a change in the dose that is crucial for side effects, especially with respect to visual acuity. The radiation oncologist has to bring these large changes in absorbed dose in the structures at risk to the attention of the surgeon, especially when the plaque has to be positioned close to relevant tissues. Conclusion: The detailed geometry of an eye plaque in computerized and segmented tomography of a realistic patient phantom was simulated accurately. Dose-volume histograms for relevant anatomical structures of the eye and the orbit were obtained with unprecedented accuracy. This represents an important step toward an optimized

Bone marrow endothelial progenitors augment atherosclerotic plaque regression in a mouse model of plasma lipid lowering

Science.gov (United States)

Yao, Longbiao; Heuser-Baker, Janet; Herlea-Pana, Oana; Iida, Ryuji; Wang, Qilong; Zou, Ming-Hui; Barlic-Dicen, Jana

2012-01-01

The major event initiating atherosclerosis is hypercholesterolemia-induced disruption of vascular endothelium integrity. In settings of endothelial damage, endothelial progenitor cells (EPCs) are mobilized from bone marrow into circulation and home to sites of vascular injury where they aid endothelial regeneration. Given the beneficial effects of EPCs in vascular repair, we hypothesized that these cells play a pivotal role in atherosclerosis regression. We tested our hypothesis in the atherosclerosis-prone mouse model in which hypercholesterolemia, one of the main factors affecting EPC homeostasis, is reversible (Reversa mice). In these mice normalization of plasma lipids decreased atherosclerotic burden; however, plaque regression was incomplete. To explore whether endothelial progenitors contribute to atherosclerosis regression, bone marrow EPCs from a transgenic strain expressing green fluorescent protein under the control of endothelial cell-specific Tie2 promoter (Tie2-GFP+) were isolated. These cells were then adoptively transferred into atheroregressing Reversa recipients where they augmented plaque regression induced by reversal of hypercholesterolemia. Advanced plaque regression correlated with engraftment of Tie2-GFP+ EPCs into endothelium and resulted in an increase in atheroprotective nitric oxide and improved vascular relaxation. Similarly augmented plaque regression was also detected in regressing Reversa mice treated with the stem cell mobilizer AMD3100 which also mobilizes EPCs to peripheral blood. We conclude that correction of hypercholesterolemia in Reversa mice leads to partial plaque regression that can be augmented by AMD3100 treatment or by adoptive transfer of EPCs. This suggests that direct cell therapy or indirect progenitor cell mobilization therapy may be used in combination with statins to treat atherosclerosis. PMID:23081735

Comparison of multislice computed tomography with intravascular ultrasound for detection and characterization of coronary artery plaques: A systematic review

Energy Technology Data Exchange (ETDEWEB)

Springer, Ivonne [Department of Radiology, Charite, Medical School, Humboldt-Universitaet zu Berlin (Germany); Dewey, Marc [Department of Radiology, Charite, Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: marc.dewey@charite.de

2009-08-15

Purpose: Multislice computed tomography (MSCT) is a novel non-invasive test for detection and analysis of coronary artery plaques. A systematic review was conducted of the literature to compare MSCT with IVUS as the reference standard for assessing coronary artery plaques. Materials and methods: We performed a literature search in the online database MEDLINE, which was accessed at (http://www.pubmed.gov) on 9th April 2008. Results: The search identified 14 studies with 340 patients (mean age 59 {+-} 5 years). The systematic review revealed a sensitivity of MSCT on the lesion level (n = 1779 coronary plaques) on the order of 90% (range from 87 to 92%) in comparison to IVUS. Per-segment analysis (n = 356) yielded a lower sensitivity of 81-86%. In the per-vessel analysis (n = 90), MSCT had a better sensitivity and specificity for the RCA (83-89% and 92-100%) and the LAD (83-87% and 93%) than for the LCX (71-85% and 77-89%), and on the vessel level and the cross-section analysis MSCT was more sensitive for calcified plaques than for non-calcified plaque. It is noteworthy that most studies provide only incomplete data on technical and methodological parameters such as radiation exposure and patient characteristics. Conclusion: MSCT is an accurate and reliable test for detection of coronary artery plaques in comparison to IVUS with limitations in regards to the LCX and non-calcified plaques. Studies published thus far are limited by the sample sizes and methodological quality issues.

Animal models to study plaque vulnerability

NARCIS (Netherlands)

Schapira, K.; Heeneman, S.; Daemen, M. J. A. P.

2007-01-01

The need to identify and characterize vulnerable atherosclerotic lesions in humans has lead to the development of various animal models of plaque vulnerability. In this review, current concepts of the vulnerable plaque as it leads to an acute coronary event are described, such as plaque rupture,

Effect of longitudinal anatomical mismatch of stenting on the mechanical environment in human carotid artery with atherosclerotic plaques.

Science.gov (United States)

Fan, Zhenmin; Liu, Xiao; Sun, Anqiang; Zhang, Nan; Fan, Zhanming; Fan, Yubo; Deng, Xiaoyan

2017-10-01

Longitudinal anatomic mismatch (LAM) of stenting (i.e., a stenotic artery segment is not fully covered by a deployed stent) worsens the mechanical environment in the treated artery, which most likely is the cause for the associated high risks of restenosis, myocardial infarction and stent thrombosis. To probe the possibility, we constructed a patient-specific carotid model with two components of plaques (lipid and calcified plaque) based on MRI images; we numerically compared three different stenting scenarios in terms of von Mises stress (VMS) distribution in the treated arteries, namely, the short stenting (LAM), the medium stenting and the long stenting. The results showed that the short stenting led to more areas with abnormally high VMS along the inner surface of the treated artery with a much higher surface-averaged VMS at the distal end of the stent than both the medium and long stenting. While the VMS distribution in the calcified plaques was similar for the three stenting models, it was quite different in the lipid plaques among the three stenting models. The lipid plaque of the short-stent model showed more volume of the lipid plaque subjected to high VMS than those of the other two models. Based on the obtained results, we may infer that the short stenting (i.e., LAM) may aggravate vascular injury due to high VMS on the artery-stent interaction surface and within the lipid plaque. Therefore, to obtain a better outcome, a longer stent, rather than a short one, might be needed for arterial stenting. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Plaquing procedure for infectious hematopoietic necrosis virus

Science.gov (United States)

Burke, J.A.; Mulcahy, D.

1980-01-01

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

Fast Streaming 3D Level set Segmentation on the GPU for Smooth Multi-phase Segmentation

DEFF Research Database (Denmark)

Sharma, Ojaswa; Zhang, Qin; Anton, François

2011-01-01

Level set method based segmentation provides an efficient tool for topological and geometrical shape handling, but it is slow due to high computational burden. In this work, we provide a framework for streaming computations on large volumetric images on the GPU. A streaming computational model...

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

Science.gov (United States)

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

2016-03-01

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

Physical model of the haemodynamic effects around the obstructing plaque in the acute coronary syndromes take account of the stenosis geometry

International Nuclear Information System (INIS)

Matveev, M.

2004-01-01

Selective coronary angiography with quantitative parameter assessment of the vessel stenosis geometry, which leads to acute coronary syndrome, was performed in 205 patients undergoing acute phase of myocardial infarction or unstable angina pectoris. Data for physicomechanical properties of the arterial vessels, blood and blood flow were used. The range of pressure variations accompanying the most frequently encountered ruptures of the atherosclerotic plaques was analyzed with physical model. It suggests that in 'lock' type plaques the ratio between the pressure on the wall of the normal vessel and that in the section outside the stenosis is considerably increased, especially in cases of enlarged vessel gauge. The results obtained show that the wall pressure closely to the plaque of a stenosed vessel with normal diameter of 3.5 mm exceeds 25 times the pressure within a normal vessel segment. (author)

Temperature distribution in atherosclerotic coronary arteries: influence of plaque geometry and flow (a numerical study)

International Nuclear Information System (INIS)

Have, A G ten; Gijsen, F J H; Wentzel, J J; Slager, C J; Steen, A F W van der

2004-01-01

Intravascular coronary thermography is a method that may detect vulnerable, atherosclerotic plaques and is currently evaluated in a clinical setting. Active macrophages or enzymatic heat releasing processes in vulnerable plaques may act as heat sources. To better understand the parameters of influence on thermographic measurements, numerical simulations have been performed on a model of a coronary artery segment containing a heat source. Heat source parameters and flow were varied to study their influence on temperatures at the lumen wall. Maximal temperature differences at the lumen wall increased when the source volume increased and they differ with the source geometry. The simulations showed that blood flow acts as a coolant to the lumen wall. Blood flow decreased maximal temperatures depending on the source geometry, source volume and the maximal flow velocity. Influence of flow was highest for circumferentially extended sources, up to a factor 3.7, and lowest for longitudinally extended sources, down to a factor 1.9. When cap thickness increased, maximal temperatures decreased and the influence of flow increased. This study shows that correct interpretation of intravascular thermographic measurements requires data on the flow and on the morphologic characteristics of the atherosclerotic plaque

Dental plaque identification at home

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/003426.htm Dental plaque identification at home To use the sharing ... a sticky substance that collects around and between teeth. The home dental plaque identification test shows where ...

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Accurate estimation of dose distributions inside an eye irradiated with {sup 106}Ru plaques

Energy Technology Data Exchange (ETDEWEB)

Brualla, L.; Sauerwein, W. [Universitaetsklinikum Essen (Germany). NCTeam, Strahlenklinik; Sempau, J.; Zaragoza, F.J. [Universitat Politecnica de Catalunya, Barcelona (Spain). Inst. de Tecniques Energetiques; Wittig, A. [Marburg Univ. (Germany). Klinik fuer Strahlentherapie und Radioonkologie

2013-01-15

Background: Irradiation of intraocular tumors requires dedicated techniques, such as brachytherapy with {sup 106}Ru plaques. The currently available treatment planning system relies on the assumption that the eye is a homogeneous water sphere and on simplified radiation transport physics. However, accurate dose distributions and their assessment demand better models for both the eye and the physics. Methods: The Monte Carlo code PENELOPE, conveniently adapted to simulate the beta decay of {sup 106}Ru over {sup 106}Rh into {sup 106}Pd, was used to simulate radiation transport based on a computerized tomography scan of a patient's eye. A detailed geometrical description of two plaques (models CCA and CCB) from the manufacturer BEBIG was embedded in the computerized tomography scan. Results: The simulations were firstly validated by comparison with experimental results in a water phantom. Dose maps were computed for three plaque locations on the eyeball. From these maps, isodose curves and cumulative dose-volume histograms in the eye and for the structures at risk were assessed. For example, it was observed that a 4-mm anterior displacement with respect to a posterior placement of a CCA plaque for treating a posterior tumor would reduce from 40 to 0% the volume of the optic disc receiving more than 80 Gy. Such a small difference in anatomical position leads to a change in the dose that is crucial for side effects, especially with respect to visual acuity. The radiation oncologist has to bring these large changes in absorbed dose in the structures at risk to the attention of the surgeon, especially when the plaque has to be positioned close to relevant tissues. Conclusion: The detailed geometry of an eye plaque in computerized and segmented tomography of a realistic patient phantom was simulated accurately. Dose-volume histograms for relevant anatomical structures of the eye and the orbit were obtained with unprecedented accuracy. This represents an important step

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

Science.gov (United States)

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

2016-02-01

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

Basal Cell Carcinoma in Type 2 Segmental Dariers Disease

International Nuclear Information System (INIS)

Robertson, L.; Sauder, M. B.

2012-01-01

Dariers disease (DD), also known as Keratosis Follicularis or Dariers-White disease, is a rare disorder of keratinisation. DD can present as a generalized autosomal dominant condition as well as a localized or segmental post zygotic condition (Vasquez et al., 2002). Clinical features of DD include greasy, warty papules and plaques on seborrhoeic areas, dystrophic nails, palmo-plantar pits, and papules on the dorsum of the hands and feet. Objective. We report a case of basal cell carcinoma developing in a patient with type 2 segmental DD. Conclusion. According to the current literature, Type 2 segmental disease is a rare presentation of Dariers disease with only 8 previous cases reported to date. In addition, non melanoma skin cancer (NMSC) arising from DD is rarely reported; however, there may be an association between DD and risk of carcinogenesis.

Basal Cell Carcinoma in Type 2 Segmental Darier's Disease

Directory of Open Access Journals (Sweden)

Lynne Robertson

2012-01-01

Full Text Available Background. Darier's disease (DD, also known as Keratosis Follicularis or Darier-White disease, is a rare disorder of keratinization. DD can present as a generalized autosomal dominant condition as well as a localized or segmental postzygotic condition (Vázquez et al., 2002. Clinical features of DD include greasy, warty papules and plaques on seborrheic areas, dystrophic nails, palmo-plantar pits, and papules on the dorsum of the hands and feet. Objective. We report a case of basal cell carcinoma developing in a patient with type 2 segmental DD. Conclusion. According to the current literature, Type 2 segmental disease is a rare presentation of Darier's disease with only 8 previous cases reported to date. In addition, nonmelanoma skin cancer (NMSC arising from DD is rarely reported; however, there may be an association between DD and risk of carcinogenesis.

Variables affecting viral plaque formation in microculture plaque assays using homologous antibody in a liquid overlay.

Science.gov (United States)

Randhawa, A S; Stanton, G J; Green, J A; Baron, S

1977-05-01

A liquid antibody microculture plaque assay and the variables that govern its effectiveness are described. The assay is based on the principle that low concentrations of homologous antibody can inhibit secondary plaque formation without inhibiting formation of primary plaques. Thus, clear plaques that followed a linear dose response were produced. The assay was found to be more rapid, less cumbersome, and less expensive than assays using agar overlays and larger tissue culture plates. It was reproducible, quantitative, and had about the same sensitivity as the agar overlay technique in measuring infectious coxsackievirus type B-3. It was more sensitive in assaying adenovirus type 3 and Western equine encephalomyelitis, vesicular stomatitis, Semliki forest, Sendai, Sindbis, and Newcastle disease viruses than were liquid, carboxymethylcellulose, and methylcellulose microculture plaque assays. The variables influencing sensitivity and accuracy, as determined by using coxsackievirus type B-3, were: (i) the inoculum volume of virus; (ii) the incubation period of virus; and (iii) the incubation temperature.

New dimensions in mechanical plaque control: An overview

Directory of Open Access Journals (Sweden)

Arnab Mandal

2017-01-01

Full Text Available Plaque control is the daily removal of dental plaque, oral biofilm and also prevention of their accumulation on the teeth and other parts of oral cavity. Dental plaque is the major etiology of maximum gingival and periodontal diseases. It is also related with various dental problems. Mechanical plaque control is a very effective method to get rid of plaque accumulation in oral cavity. In 3000 BC there was the first toothbrush invented by human beings. With time several modifications came in toothbrushes to make mechanical plaque control more effective in day to day oral hygiene practice. This article emphasizes on the advanced and emerging tools in mechanical plaque control methods in attaining an optimal level of oral hygiene standards and maintenance of oral health.

Dosimetric Benefit of a New Ophthalmic Radiation Plaque

Energy Technology Data Exchange (ETDEWEB)

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

2012-12-01

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

Dosimetric Benefit of a New Ophthalmic Radiation Plaque

International Nuclear Information System (INIS)

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

2012-01-01

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

Identifying Vulnerable Atherosclerotic Plaque in Rabbits Using DMSA-USPIO Enhanced Magnetic Resonance Imaging to Investigate the Effect of Atorvastatin.

Directory of Open Access Journals (Sweden)

Chunmei Qi

Full Text Available Rupture of an atherosclerotic plaque is the primary cause of acute cardiovascular and cerebrovascular syndromes. Early and non-invasive detection of vulnerable atherosclerotic plaques (VP would be significant in preventing some aspects of these syndromes. As a new contrast agent, dimercaptosuccinic acid (DMSA modified ultra-small super paramagnetic iron oxide (USPIO was synthesized and used to identify VP and rupture plaque by magnetic resonance imaging (MRI.Atherosclerosis was induced in male New Zealand White rabbits by feeding a high cholesterol diet (n = 30. Group A with atherosclerosis plaque (n = 10 were controls. VP was established in groups B (n = 10 and C (n = 10 using balloon-induced endothelial injury of the abdominal aorta. Adenovirus-carrying p53 genes were injected into the aortic segments rich in plaques after 8 weeks. Group C was treated with atorvastatin for 8 weeks. Sixteen weeks later, all rabbits underwent pharmacological triggering, and imaging were taken daily for 5 d after DMSA-USPIO infusion. At the first day and before being killed, serum MMP-9, sCD40L, and other lipid indicators were measured.DMSA-USPIO particles accumulated in VP and rupture plaques. Rupture plaques appeared as areas of hyper-intensity on DMSA-USPIO enhanced MRI, especially T2*-weighted sequences, with a signal strength peaking at 96 h. The group given atorvastatin showed few DMSA-USPIO particles and had lower levels of serum indicators. MMP-9 and sCD40L levels in group B were significantly higher than in the other 2 groups (P <0.05.After successfully establishing a VP model in rabbits, DMSA-USPIO was used to enhance MRI for clear identification of plaque inflammation and rupture. Rupture plaques were detectable in this way probably due to an activating inflammatory process. Atorvastatin reduced the inflammatory response and stabilizing VP possibly by decreasing MMP-9 and sCD40L levels.

Current diagnostic modalities for vulnerable plaque detection

NARCIS (Netherlands)

J.A. Schaar (Johannes); F. Mastik (Frits); E.S. Regar (Eveline); C.A. den Uil (Corstiaan); F.J.H. Gijsen (Frank); J.J. Wentzel (Jolanda); P.W.J.C. Serruys (Patrick); A.F.W. van der Steen (Ton)

2007-01-01

textabstractRupture of vulnerable plaques is the main cause of acute coronary syndrome and myocardial infarction. Identification of vulnerable plaques is therefore essential to enable the development of treatment modalities to stabilize such plaques. Several diagnostic methods are currently tested

Gene expression levels of matrix metalloproteinases in human atherosclerotic plaques and evaluation of radiolabeled inhibitors as imaging agents for plaque vulnerability

International Nuclear Information System (INIS)

Müller, Adrienne; Krämer, Stefanie D.; Meletta, Romana; Beck, Katharina; Selivanova, Svetlana V.; Rancic, Zoran; Kaufmann, Philipp A.; Vos, Bernhard; Meding, Jörg; Stellfeld, Timo; Heinrich, Tobias K.; Bauser, Marcus; Hütter, Joachim; Dinkelborg, Ludger M.; Schibli, Roger; Ametamey, Simon M.

2014-01-01

Introduction: Atherosclerotic plaque rupture is the primary cause for myocardial infarction and stroke. During plaque progression macrophages and mast cells secrete matrix-degrading proteolytic enzymes, such as matrix metalloproteinases (MMPs). We studied levels of MMPs and tissue inhibitor of metalloproteinases-3 (TIMP-3) in relation to the characteristics of carotid plaques. We evaluated in vitro two radiolabeled probes targeting active MMPs towards non-invasive imaging of rupture-prone plaques. Methods: Human carotid plaques obtained from endarterectomy were classified into stable and vulnerable by visual and histological analysis. MMP-1, MMP-2, MMP-8, MMP-9, MMP-10, MMP-12, MMP-14, TIMP-3, and CD68 levels were investigated by quantitative polymerase chain reaction. Immunohistochemistry was used to localize MMP-2 and MMP-9 with respect to CD68-expressing macrophages. Western blotting was applied to detect their active forms. A fluorine-18-labeled MMP-2/MMP-9 inhibitor and a tritiated selective MMP-9 inhibitor were evaluated by in vitro autoradiography as potential lead structures for non-invasive imaging. Results: Gene expression levels of all MMPs and CD68 were elevated in plaques. MMP-1, MMP-9, MMP-12 and MMP-14 were significantly higher in vulnerable than stable plaques. TIMP-3 expression was highest in stable and low in vulnerable plaques. Immunohistochemistry revealed intensive staining of MMP-9 in vulnerable plaques. Western blotting confirmed presence of the active form in plaque lysates. In vitro autoradiography showed binding of both inhibitors to stable and vulnerable plaques. Conclusions: MMPs differed in their expression patterns among plaque phenotypes, providing possible imaging targets. The two tested MMP-2/MMP-9 and MMP-9 inhibitors may be useful to detect atherosclerotic plaques, but not the vulnerable lesions selectively

Plaque Index in Multi-Bracket Fixed Appliances

International Nuclear Information System (INIS)

Rahim, Z.H.; Shaikh, S.; Razak, F.A.

2014-01-01

To compare the plaque index in patients receiving multi-bracket fixed orthodontic treatment for various factors like age, gender, socio-economic status, brushing practices, meal habits, types of brackets, types of ligations, use of mouthwash and duration of treatment. Study Design: Cross-sectional analytical study. Place and Duration of Study: Orthodontics Clinic, The Aga Khan University Hospital, from September to November 2011. Methodology: Socio-demographic and clinical modalities were defined and recorded for 131 patients having multi-bracket fixed appliances. The plaque index of subjects were recorded according to the Silness and Loe plaque index method. Independent sample t-test was used to see difference in plaque index in factors having two variables. One way ANOVA and Post-Hoc Tukey tests were used to see difference in plaque index in factors having three variables. Kappa statistics was used to assess inter examiner reliability. P-value 0.05 was taken to be significant. Results: The sample comprised of 37% males (n = 48) and 63% females (n = 83). The plaque index had statistically significant association with practice of brushing i.e., timing of brushing (p=0.001), method of brushing (p=0.08), type of ligatures (p=0.05) and frequency of visits (p=0.01). Conclusion: The plaque accumulation is significantly decreased in subjects who brush the teeth twice or more than twice a day and those who brush their teeth after breakfast. The use of interdental brush and stainless steel ligatures had significantly low plaque. Subjects presenting with more frequent appointments of short-period had significantly less plaque. (author)

Clinical Relevance of 18F-Sodium Fluoride Positron-Emission Tomography in Noninvasive Identification of High-Risk Plaque in Patients With Coronary Artery Disease.

Science.gov (United States)

Lee, Joo Myung; Bang, Ji-In; Koo, Bon-Kwon; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Yaliang, Tong; Suh, Minseok; Paeng, Jin Chul; Shiono, Yasutsugu; Kubo, Takashi; Akasaka, Takashi

2017-11-01

18 F-sodium fluoride ( 18 F-NaF) positron-emission tomography has been introduced as a potential noninvasive imaging tool to identify plaques with high-risk characteristics in patients with coronary artery disease. We sought to evaluate the clinical relevance of 18 F-NaF uptake using optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography in patients with coronary artery disease. The target population consisted of 51 prospectively enrolled patients (93 stenoses) who underwent 18 F-NaF positron-emission tomography before invasive coronary angiography. 18 F-NaF uptake was compared with IVUS- and OCT-derived plaque characteristics. In the coronary computed tomography angiography subgroup (46 lesions), qualitative lesion characteristics were compared between 18 F-NaF-positive and 18 F-NaF-negative plaques using adverse plaque characteristics. The plaques with 18 F-NaF uptake showed significantly higher plaque burden, more frequent posterior attenuation and positive remodeling in IVUS, and significantly higher maximum lipid arc and more frequent microvessels in OCT (all P characteristics. The 18 F-NaF tissue-to-background ratio in plaques with high-risk characteristics was significantly higher than in those without (1.09 [95% confidence interval, 0.85-1.34] versus 0.62 [95% confidence interval, 0.42-0.82], P characteristics between 18 F-NaF-positive and 18 F-NaF-negative plaques in the coronary computed tomography angiography subgroup (85.2% versus 78.9%; P =0.583). This study's results suggest that 18 F-NaF positron-emission tomography can be a useful noninvasive diagnostic tool to identify and localize plaque with high-risk characteristics. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02388412. © 2017 American Heart Association, Inc.

PLAQUE ASSAY OF NEWCASTLE DISEASE VIRUS

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B. Sardjono

2012-09-01

Full Text Available The Newcastle disease virus (NDV was isolated from a 3 months-old indigenous chicken (buras or kampung chicken which showed clinical signs of Newcastle disease (ND. For viral isolation a small part of the spleen and lung were inoculated into 10 days-old embryonated chicken eggs. The physical characteristics of the isolate (A/120 were studied. The hemagglutination of chicken red blood cell showed slow elution, thermostability of hemagglutinin at 56°C was 120 minutes. The vims was able to agglutinate horse erythrocytes but not those of sheep. The biological characteristics on mean death time (MDT of embryonated chicken egg and plaque morphology on chicken embryo fibroblast (CEF primary cell cultures were studied. The MDT was 56 hours, the isolate was velogenic NDV. There were three different plaque morphologies on CEF : 2 mm clear plaques, 1 mm clear plaques, and minute clear plaques which were visible only with microscopic examination.

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

DEFF Research Database (Denmark)

van Engelen, Arna; de Bruijne, Marleen; Klein, Stefan

2011-01-01

registration of histology data with ex vivo MRI data, using non-rigid registration, both for training and evaluation. This is more objective than previously presented methods, as it eliminates selection bias that is introduced when 2D MRI slices are manually matched to histological slices before evaluation....... Histological slices of human atherosclerotic plaques were manually segmented into necrotic core, fibrous tissue and calcification. Classification of these three components was voxelwise evaluated. As features the intensity, gradient magnitude and Laplacian in four MRI sequences after different degrees...

MR plaque imaging of the carotid artery

International Nuclear Information System (INIS)

Watanabe, Yuji; Nagayama, Masako

2010-01-01

Atherosclerotic carotid plaque represents a major cause of cerebral ischemia. The detection of vulnerable plaque is important for preventing future cardiovascular events. The key factors in advanced plaque that are most likely to lead to patient complications are the condition of the fibrous cap, the size of the necrotic core and hemorrhage, and the extent of inflammatory activity within the plaque. Magnetic resonance (MR) imaging has excellent soft tissue contrast and can allow for a more accurate and objective estimation of carotid wall morphology and plaque composition. Recent advances in MR imaging techniques have permitted serial monitoring of atherosclerotic disease evolution and the identification of intraplaque risk factors for accelerated progression. The purpose of this review article is to review the current state of techniques of carotid wall MR imaging and the characterization of plaque components and surface morphology with MR imaging, and to describe the clinical practice of carotid wall MR imaging for the determination of treatment plan. (orig.)

A computer-simulation study on the effects of MRI voxel dimensions on carotid plaque lipid-core and fibrous cap segmentation and stress modeling.

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Harm A Nieuwstadt

Full Text Available The benefits of a decreased slice thickness and/or in-plane voxel size in carotid MRI for atherosclerotic plaque component quantification accuracy and biomechanical peak cap stress analysis have not yet been investigated in detail because of practical limitations.In order to provide a methodology that allows such an investigation in detail, numerical simulations of a T1-weighted, contrast-enhanced, 2D MRI sequence were employed. Both the slice thickness (2 mm, 1 mm, and 0.5 mm and the in plane acquired voxel size (0.62x0.62 mm2 and 0.31x0.31 mm2 were varied. This virtual MRI approach was applied to 8 histology-based 3D patient carotid atherosclerotic plaque models.A decreased slice thickness did not result in major improvements in lumen, vessel wall, and lipid-rich necrotic core size measurements. At 0.62x0.62 mm2 in-plane, only a 0.5 mm slice thickness resulted in improved minimum fibrous cap thickness measurements (a 2-3 fold reduction in measurement error and only marginally improved peak cap stress computations. Acquiring voxels of 0.31x0.31 mm2 in-plane, however, led to either similar or significantly larger improvements in plaque component quantification and computed peak cap stress.This study provides evidence that for currently-used 2D carotid MRI protocols, a decreased slice thickness might not be more beneficial for plaque measurement accuracy than a decreased in-plane voxel size. The MRI simulations performed indicate that not a reduced slice thickness (i.e. more isotropic imaging, but the acquisition of anisotropic voxels with a relatively smaller in-plane voxel size could improve carotid plaque quantification and computed peak cap stress accuracy.

Electric Power Distribution System Model Simplification Using Segment Substitution

Energy Technology Data Exchange (ETDEWEB)

Reiman, Andrew P.; McDermott, Thomas E.; Akcakaya, Murat; Reed, Gregory F.

2018-05-01

Quasi-static time-series (QSTS) simulation is used to simulate the behavior of distribution systems over long periods of time (typically hours to years). The technique involves repeatedly solving the load-flow problem for a distribution system model and is useful for distributed energy resource (DER) planning. When a QSTS simulation has a small time step and a long duration, the computational burden of the simulation can be a barrier to integration into utility workflows. One way to relieve the computational burden is to simplify the system model. The segment substitution method of simplifying distribution system models introduced in this paper offers model bus reduction of up to 98% with a simplification error as low as 0.2% (0.002 pu voltage). In contrast to existing methods of distribution system model simplification, which rely on topological inspection and linearization, the segment substitution method uses black-box segment data and an assumed simplified topology.

Electric Power Distribution System Model Simplification Using Segment Substitution

International Nuclear Information System (INIS)

Reiman, Andrew P.; McDermott, Thomas E.; Akcakaya, Murat; Reed, Gregory F.

2017-01-01

Quasi-static time-series (QSTS) simulation is used to simulate the behavior of distribution systems over long periods of time (typically hours to years). The technique involves repeatedly solving the load-flow problem for a distribution system model and is useful for distributed energy resource (DER) planning. When a QSTS simulation has a small time step and a long duration, the computational burden of the simulation can be a barrier to integration into utility workflows. One way to relieve the computational burden is to simplify the system model. The segment substitution method of simplifying distribution system models introduced in this paper offers model bus reduction of up to 98% with a simplification error as low as 0.2% (0.002 pu voltage). Finally, in contrast to existing methods of distribution system model simplification, which rely on topological inspection and linearization, the segment substitution method uses black-box segment data and an assumed simplified topology.

Influence of ezetimibe in addition to high-dose atorvastatin therapy on plaque composition in patients with ST-segment elevation myocardial infarction assessed by serial Intravascular ultrasound with iMap: the OCTIVUS trial*

DEFF Research Database (Denmark)

Hougaard, Mikkel; Hansen, Henrik Steen; Thayssen, Per

2017-01-01

Background: The aim of this study was to examine the influence of ezetimibe in addition to atorvastatin on plaque composition in patients with first-time ST-segment Elevation Myocardial Infarction treated with primary percutaneous intervention. Methods: Eighty-seven patients were randomized ( 1: 1......) to ezetimibe 10mg or placebo in addition to Atorvastatin 80 mg. Intravascular ultrasound with iMap was performed at baseline and after 12 months in a non-infarctrelated artery. Primary endpoint was change in necrotic core (NC). Secondary endpoints were total atheroma volume (TAV) and percentage atheroma volume.......3 +/- 9.4% to 42.2 +/- 10.7 p - 0.07),p - 0.91 between groups. Conclusions: Ezetimibe in addition to atorvastatin therapy did not influence NC content, but was associated with regression of coronary atherosclerosis. (C) 2016 Elsevier Inc. All rights reserved....

PET/CT for atherosclerotic plaque imaging

International Nuclear Information System (INIS)

Ben-Haim, S.; Technion Institute of Technology, Haifa; Israel, O.; Rambam Medical Center, Haifa

2006-01-01

Atherosclerosis is one of the leading causes of morbidity and mortality in the world. Rupture of atherosclerotic plaques and thrombi formation are the primary mechanisms of myocardial infarction or cerebrovascular accident. Angiography is considered to represent the gold standard technique for imaging of the arterial lumen. However, in recent years it has been realized that the primary determinant of the atherosclerotic plaque stability is the composition of the plaque and other imaging modalities have been suggested. The purpose of this review is to briefly summarize the knowledge accumulated to present date regarding the potential role of fluo deoxyglucose imaging in the assessment of atherosclerosis and to compare this modality to additional available imaging approaches for the detection of vulnerable plaques

The effect of pH, temperature and plaque thickness on the hydrolysis of monofluorophosphate in experimental dental plaque.

Science.gov (United States)

Pearce, E I F; Dibdin, G H

2003-01-01

Monofluorophosphate (MFP), an anti-caries agent commonly used in toothpaste, is known to be degraded to fluoride and orthophosphate by bacterial phosphatases in dental plaque. We have examined the effect of pH, temperature, plaque thickness and some ions on this process. Both natural plaque and artificial microcosm plaque incubated with purified MFP at pH 4-10 showed an optimum pH of approximately 8 for hydrolysis. Diffusion and concomitant hydrolysis were examined in an apparatus in which artificial plaque was held between rigid membranes separating two chambers. When MFP diffused through a plaque of 0.51-mm thickness over 4 h it was almost completely hydrolysed at pH 8, but hydrolysis on diffusion decreased as the pH deviated from 8. MFP in toothpaste extract showed a similar pH susceptibility to hydrolysis, according to the inherent pH of the toothpaste. Hydrolysis of MFP in the toothpaste was reduced by no more than 10% when compared with a matched-pH control, suggesting that other toothpaste ingredients had no major influence on hydrolysis. Transport was slower and hydrolysis at pH 6 more complete the thicker the plaque, but hydrolysis was not significantly slower at 23 degrees C than at 37 degrees C. The addition of various potential activating or inhibiting ions at 0.1 and 1.0 mmol/l had small and non-significant effects on hydrolysis. The results suggest that MFP toothpaste should be formulated and used to maximise enzymic hydrolysis of this complex anion, and that plaque pH control is probably the most important factor. Copyright 2003 S. Karger AG, Basel

Altered carotid plaque signal among different repetition times on T1-weighted magnetic resonance plaque imaging with self-navigated radial-scan technique

Energy Technology Data Exchange (ETDEWEB)

Narumi, Shinsuke; Ohba, Hideki; Mori, Kiyofumi; Ohura, Kazumasa; Ono, Ayumi; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto [Iwate Medical University, Advanced Medical Research Center, Morioka (Japan); Ogasawara, Kuniaki [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Hitomi, Jiro [Iwate Medical University, Department of Anatomy, Morioka (Japan)

2010-04-15

Magnetic resonance (MR) plaque imaging for carotid arteries is usually performed by using an electrocardiograph (ECG)-gating technique to eliminate pulsation-related artifacts, which can affect the plaque signals because of varied repetition time (TR) among patients. Hence, we investigated whether differences in TR causes signal alterations of the carotid plaque by using a non-gated plaque imaging technique. We prospectively examined 19 patients with carotid stenosis by using a T1-weighted self-navigated radial-scan technique with TRs of 500, 700, and 900 ms. The signal intensity of the carotid plaque was measured, and the contrast ratio (CR) relative to the adjacent muscle was calculated. CRs of the carotid plaques were 1.39 {+-} 0.39, 1.29 {+-} 0.29, and 1.23 {+-} 0.24 with TRs of 500, 700, and 900 ms, respectively, and were significantly different. Among the plaques, those with a hyperintensity signal (CR > 1.5) and moderate-intensity signal (CR 1.2-1.5) at 500 ms showed a TR-dependent signal decrease (hyperintensity plaques, 1.82 {+-} 0.26; 1.61 {+-} 0.19; and 1.48 {+-} 0.17; moderate-intensity plaques, 1.33 {+-} 0.08; 1.26 {+-} 0.08; and 1.19 {+-} 0.07), while those with an isointensity signal (CR < 1.2) remained unchanged regardless of TR (0.96 {+-} 0.12, 0.96 {+-} 0.11, and 0.97 {+-} 0.13). The signal intensity of the carotid plaque on T1-weighted imaging significantly varies among different TRs and tends to decrease with longer TR. MR plaque imaging with short and constant TR settings that the ECG-gating method cannot realize would be preferable for evaluating plaque characteristics. (orig.)

Near-Infrared Spectroscopy Enhances Intravascular Ultrasound Assessment of Vulnerable Coronary Plaque: A Combined Pathological and In Vivo Study.

Science.gov (United States)

Puri, Rishi; Madder, Ryan D; Madden, Sean P; Sum, Stephen T; Wolski, Kathy; Muller, James E; Andrews, Jordan; King, Karilane L; Kataoka, Yu; Uno, Kiyoko; Kapadia, Samir R; Tuzcu, E Murat; Nissen, Steven E; Virmani, Renu; Maehara, Akiko; Mintz, Gary S; Nicholls, Stephen J

2015-11-01

Pathological studies demonstrate the dual significance of plaque burden (PB) and lipid composition for mediating coronary plaque vulnerability. We evaluated relationships between intravascular ultrasound (IVUS)-derived PB and arterial remodeling with near-infrared spectroscopy (NIRS)-derived lipid content in ex vivo and in vivo human coronary arteries. Ex vivo coronary NIRS and IVUS imaging was performed through blood in 116 coronary arteries of 51 autopsied hearts, followed by 2-mm block sectioning (n=2070) and histological grading according to modified American Heart Association criteria. Lesions were defined as the most heavily diseased 2-mm block per imaged artery on IVUS. IVUS-derived PB and NIRS-derived lipid core burden index (LCBI) of each block and lesion were analyzed. Block-level analysis demonstrated significant trends of increasing PB and LCBI across more complex atheroma (Ptrend <0.001 for both LCBI and PB). Lesion-based analyses demonstrated the highest LCBI and remodeling index within coronary fibroatheroma (Ptrend <0.001 and 0.02 versus all plaque groups, respectively). Prediction models demonstrated similar abilities of PB, LCBI, and remodeling index for discriminating fibroatheroma (c indices: 0.675, 0.712, and 0.672, respectively). A combined PB+LCBI analysis significantly improved fibroatheroma detection accuracy (c index 0.77, P=0.028 versus PB; net-reclassification index 43%, P=0.003), whereas further adding remodeling index did not (c index 0.80, P=0.27 versus PB+LCBI). In vivo comparisons of 43 age- and sex-matched patients (to the autopsy cohort) undergoing combined NIRS-IVUS coronary imaging yielded similar associations to those demonstrated ex vivo. Adding NIRS to conventional IVUS-derived PB imaging significantly improves the ability to detect more active, potentially vulnerable coronary atheroma. © 2015 American Heart Association, Inc.

Early characterization of atherosclerotic coronary plaques with multidetector computed tomography in patients with acute coronary syndrome. A comparative study with intravascular ultrasound

Energy Technology Data Exchange (ETDEWEB)

Iriart, Xavier; Dos-Santos, Pierre [Universite Bordeaux 2, Inserm U. 441 Atherosclerose, Bordeaux (France); Brunot, Sebastien [CHU de Bordeaux, Hopital du Haut-Leveque, Unite d' Imagerie Thoracique et Cardiovasculaire, Pessac (France); Unite de Soins Intensifs Cardiologiques, Pessac (France); Unite d' Imagerie Thoracique et Cardiovasculaire, Hopital Cardiologique, Pessac (France); Coste, Pierre; Leroux, Lionel [Universite Bordeaux 2, Inserm U. 441 Atherosclerose, Bordeaux (France); Unite de Soins Intensifs Cardiologiques, Pessac (France); Montaudon, Michel [Universite Bordeaux 2, Inserm U. 885 F 33076, Bordeaux (France); CHU de Bordeaux, Hopital du Haut-Leveque, Unite d' Imagerie Thoracique et Cardiovasculaire, Pessac (France); Labeque, Jean-Noel; Jais, Catherine [Unite de Soins Intensifs Cardiologiques, Pessac (France); Laurent, Francois [Universite Bordeaux 2, Inserm U. 885 F 33076, Bordeaux (France); CHU de Bordeaux, Hopital du Haut-Leveque, Unite d' Imagerie Thoracique et Cardiovasculaire, Pessac (France); Unite d' Imagerie Thoracique et Cardiovasculaire, Hopital Cardiologique, Pessac (France)

2007-10-15

We compared 16-slice computed tomography (CT) with intravascular ultrasound (IVUS) in their ability to identify the culprit lesion, and to assess plaque characterization and vascular remodelling in acute coronary syndrome (ACS). Twenty patients were prospectively studied. Coronary plaque identification and characterization were compared using 16-slice CT and 40-MHz catheter-based IVUS. Minimum lumen area (MLA), cross-sectional vessel area (CVA) and vessel remodelling were determined for each comparable lesion. One hundred and sixty-nine segments were compared and 84 plaques analysed. Sixteen-slice CT detected 95% of culprit lesions (19/20). No feature suggestive of plaque rupture was detected by 16-slice CT. Attenuation measurements within all lesions revealed different values for hypoechoic (38 {+-} 33 HU), hyperechoic (94 {+-} 44 HU), and calcified plaques (561 {+-} 216 HU), (P < 0.001). Agreement between 16-slice CT and IVUS on measuring MLA and CVA was evaluated using Bland-Altman analysis. Pearson and intra-class coefficient (ICC) were 0.81 and 0.70 for MLA, and 0.81 and 0.36 for CVA, for 16-slice CT and IVUS, respectively. Agreement between both techniques for vessel positive remodelling was moderate (kappa = 0.54, P < 0.001). Sixteen-slice CT has shown moderate accuracy in quantifying and characterizing coronary plaques compared with IVUS. Spatial resolution of 16-slice CT remains a major limitation, however, to accurately assess the complex lesions involved in ACS. (orig.)

Treatment of Plaque-Type Psoriasis With Oral CF101: Data from a Phase II/III Multicenter, Randomized, Controlled Trial.

Science.gov (United States)

David, Michael; Gospodinov, Dimitar Konstantinov; Gheorghe, Nicola; Mateev, Grisha Stefanov; Rusinova, Mariyana Venelinova; Hristakieva, Evgeniya; Solovastru, Laura Gheuca; Patel, Rita V; Giurcaneanu, Calin; Hitova, Mariela Chepileva; Purcaru, Anca Ioana; Horia, Beti; Tsingov, Iliya Iliev; Yankova, Rumyana Kaloferova; Kadurina, Miroslava Ilieva; Ramon, Michal; Rotaru, Maria; Simionescu, Olga; Benea, Vasile; Demerdjieva, Zdravka Velichkova; Cosgarea, Maria Rodica; Morariu, Horia Silviu; Michael, Ziv; Cristodor, Patricia; Nica, Carmen; Silverman, Michael H; Bristol, David R; Harpaz, Zivit; Farbstein, Motti; Cohen, Shira; Fishman, Pnina

2016-08-01

CF101, an adenosine A3 receptor agonist, is an orally bioavailable small molecule drug presenting an anti-psoriatic effect demonstrated in a Phase 2 clinical trial in psoriasis patients. To evaluate the safety and efficacy of CF101 treatment in a Phase 2/3 study in patients with moderate to severe plaque-type psoriasis. This multicenter, double-blind, 2-segment, placebo-controlled study randomized subjects with moderate to severe plaque psoriasis to CF101 1 or 2 mg, or placebo twice daily. At either week 12 (Segment 1) or 16 (Segment 2), the placebo group crossed over to CF101 BID through week 32 in an open-label fashion. At week 12, following an interim analysis, the CF101 1mg group was discontinued due to futility. The primary endpoint was proportion of patients achieving ≥75% improvement in Psoriasis Area Severity Index (PASI 75). Efficacy testing was performed using the Cochran-Mantel Haenszel test, the primary analysis of PASI 75 was performed at the 0.035 significance level. CF101 had an excellent safety profile at all tested dosages with a profile similar to the placebo group. The most common adverse events were infections and gastrointestinal events, and there was no cumulative intolerance over the 32-week dosing period. The study did not meet the primary endpoint of PASI 75 at week 12 (2 mg: 8.5% vs. placebo: 6.9%, P=0.621). However, at week 32, PASI mean percent improvement with CF101 2 mg was 57% (P<0.001) compared to baseline, with linear improvement in PASI 50 (63.5%), 75 (35.5%), 90 (24.7%), and 100 (10.6%). Oral CF101 was found to be safe and very well tolerated, demonstrating evidence of efficacy in patients with moderate to severe plaque psoriasis through 32 weeks of treatment. J Drugs Dermatol. 2016;15(8):931-938.

Coronary plaque morphology on multi-modality imagining and periprocedural myocardial infarction after percutaneous coronary intervention

Directory of Open Access Journals (Sweden)

Akira Sato

2016-06-01

Full Text Available Percutaneous coronary intervention (PCI may be complicated by periprocedural myocardial infarction (PMI as manifested by elevated cardiac biomarkers such as creatine kinase (CK-MB or troponin T. The occurrence of PMI has been shown to be associated with worse short- and long-term clinical outcome. However, recent studies suggest that PMI defined by biomarker levels alone is a marker of atherosclerosis burden and procedural complexity but in most cases does not have independent prognostic significance. Diagnostic multi-modality imaging such as intravascular ultrasound, optical coherence tomography, coronary angioscopy, near-infrared spectroscopy, multidetector computed tomography, and magnetic resonance imaging can be used to closely investigate the atherosclerotic lesion in order to detect morphological markers of unstable and vulnerable plaques in the patients undergoing PCI. With the improvement of technical aspects of multimodality coronary imaging, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes. There were numerous published data regarding the relationship between pre-PCI lesion subsets on multi-modality imaging and post-PCI biomarker levels. In this review, we discuss the relationship between coronary plaque morphology estimated by invasive or noninvasive coronary imaging and the occurrence of PMI. Furthermore, this review underlies that the value of the multimodality coronary imaging approach will become the gold standard for invasive or noninvasive prediction of PMI in clinical practice.

Contemporary management of moderate to severe plaque psoriasis.

Science.gov (United States)

Wu, Jashin J

2017-12-01

Psoriasis is a multisystem inflammatory disease that is often underdiagnosed, leaving many patients untreated. Plaque psoriasis, the most common form of the disease, affects approximately 80% to 90% of patients with psoriasis. Formulating a treatment plan can be complicated when various factors are considered. For example, type of therapy is dependent on the severity of the disease. Topical agents are preferred for mild disease, while phototherapy alone or in combination with systemic agents is recommended for the treatment of moderate to severe plaque psoriasis. Traditional systemic agents have the convenience of oral dosing; however, their toxicity profile can be a limiting factor. Newer biologic agents haven proven efficacious, if not superior to traditional oral agents, but their high cost can be a substantial disadvantage. Psoriasis has also been associated with increased risk of developing comorbidities, such as cardiovascular disease, obesity, and psoriatic arthritis, all of which increase the patient's overall mortality and further worsen their overall physical well-being. Management of these comorbidities is often overlooked. Moreover, psoriasis may affect a patient's psychological and social well-being. Patients with psoriasis are at a higher risk of developing clinical depression than patients without psoriasis. Inadequate management of comorbidities inevitably leads to poor outcomes, which increases the economic burden to the patient and society. Prevention and management of comorbidities, including cardiovascular and mental health, must be addressed as a part of a patient's overall treatment plan. Specialist coordination may be beneficial for patients with psoriasis. Improved patient care may lead to better clinical and economical outcomes.

Association of Streptococcus with Plaque Type of Psoriasis

Directory of Open Access Journals (Sweden)

Mohammad Akram Hossain

2015-05-01

Full Text Available Background: Guttate psoriasis has a well-known association with streptococcal throat infections, but the effects of these infections in patients with chronic plaque type of psoriasis remains to be evaluated. In Bangladesh several studies were done on psoriasis but no data about association between streptococcal throat infection and plaque type psoriasis are available so far. Considering the co-morbidities of psoriasis patients, it might be justifiable to find out the events that provoke the initiation or exacerbation of psoriatic disease process. Objective: To observe the association of streptococcus with plaque type of psoriasis. Materials and Methods: This observational study was conducted in the department of Dermatology and Venereology, Bangabandhu Sheikh Mujib Medical University, Dhaka. Forty seven patients clinically and histopathologically diagnosed as having plaque psoriasis were selected as cases and patients with skin diseases other than psoriasis were selected as controls. Results: In this study majority of subjects (55% were diagnosed as chronic plaque psoriasis. Among the subjects with guttate flare of chronic plaque psoriasis 64.2% gave a positive history of sore throat. ASO titer was raised (>200 IU/mL in 28 (59.5% patients of chronic plaque psoriasis and 7 (17.9% patients of non-psoriatic respondents. The difference between two groups was significant (p0.05. Conclusion: This study shows that streptococcal throat infections are associated with plaque psoriasis and early treatment of throat infections may be beneficial for plaque type of psoriasis patients.

Atherosclerotic Plaque Destabilization in Mice: A Comparative Study.

Directory of Open Access Journals (Sweden)

Helene Hartwig

Full Text Available Atherosclerosis-associated diseases are the main cause of mortality and morbidity in western societies. The progression of atherosclerosis is a dynamic process evolving from early to advanced lesions that may become rupture-prone vulnerable plaques. Acute coronary syndromes are the clinical manifestation of life-threatening thrombotic events associated with high-risk vulnerable plaques. Hyperlipidemic mouse models have been extensively used in studying the mechanisms controlling initiation and progression of atherosclerosis. However, the understanding of mechanisms leading to atherosclerotic plaque destabilization has been hampered by the lack of proper animal models mimicking this process. Although various mouse models generate atherosclerotic plaques with histological features of human advanced lesions, a consensus model to study atherosclerotic plaque destabilization is still lacking. Hence, we studied the degree and features of plaque vulnerability in different mouse models of atherosclerotic plaque destabilization and find that the model based on the placement of a shear stress modifier in combination with hypercholesterolemia represent with high incidence the most human like lesions compared to the other models.

Bone marrow endothelial progenitors in atherosclerotic plaque resolution

Science.gov (United States)

Yao, Longbiao; Heuser-Baker, Janet; Herlea-Pana, Oana; Barlic-Dicen, Jana

2013-01-01

Atherosclerosis is a major cause of morbidity and mortality in the United States. Persistently elevated circulating low-density lipoprotein, or hypercholesterolemia, and deposition of low-density lipoprotein in the vascular wall are the main inducers of atherosclerosis, which manifests itself as arterial lesions or plaques. Some plaques become thrombosis-prone and rupture, causing acute myocardial infarction or stroke. Lowering plasma cholesterol through the use of statins is the primary intervention against atherosclerosis. Treatment with statins slows progression of atherosclerosis but can only support limited plaque regression. Partially regressed plaques continue to pose a serious threat due to their remaining potential to rupture. Thus, new interventions inducing complete reversal of atherosclerosis are being sought. Implementation of new therapies will require clear understanding of the mechanisms driving plaque resolution. In this Commentary, we highlight the role of bone marrow endothelial progenitors in atherosclerotic plaque regression and discuss how regenerative cell-based interventions could be used in combination with plasma lipid-lowering to induce plaque reversal in order to prevent and/or reduce adverse cardiovascular events. PMID:23538778

3D Fiber Orientation in Atherosclerotic Carotid Plaques

NARCIS (Netherlands)

A.C. Akyildiz (Ali); C.-K. Chai (Chen-Ket); C.W.J. Oomens (Cees); A. van der Lugt (Aad); F.P.T. Baaijens (Frank); G.J. Strijkers (Gustav); F.J.H. Gijsen (Frank)

2017-01-01

textabstractAtherosclerotic plaque rupture is the primary trigger of fatal cardiovascular events. Fibrillar collagen in atherosclerotic plaques and their directionality are anticipated to play a crucial role in plaque rupture. This study aimed assessing 3D fiber orientations and architecture in

Initial stress in biomechanical models of atherosclerotic plaques

NARCIS (Netherlands)

Speelman, L.; Akyildiz, A.C.; Adel, den B.; Wentzel, J.J.; Steen, van der A.F.W.; Virmani, R.; Weerd, van der L.; Jukema, J.W.; Poelmann, R.E.; Brummelen, van E.H.; Gijsen, F.J.H.

2011-01-01

Rupture of atherosclerotic plaques is the underlying cause for the majority of acute strokes and myocardial infarctions. Rupture of the plaque occurs when the stress in the plaque exceeds the strength of the material locally. Biomechanical stress analyses are commonly based on pressurized

Characteristics of coronary artery disease in symptomatic type 2 diabetic patients: evaluation with CT angiography

Directory of Open Access Journals (Sweden)

Zhu Zhi-yu

2010-11-01

Full Text Available Abstract Background Coronary artery disease (CAD is a common and severe complication of type 2 diabetes mellitus (DM. The aim of this study is to identify the features of CAD in diabetic patients using coronary CT angiography (CTA. Methods From 1 July 2009 to 20 March 2010, 113 consecutive patients (70 men, 43 women; mean age, 68 ± 10 years with type 2 DM were found to have coronary plaques on coronary CTA. Their CTA data were reviewed, and extent, distribution and types of plaques and luminal narrowing were evaluated and compared between different sexes. Results In total, 287 coronary vessels (2.5 ± 1.1 per patient and 470 segments (4.2 ± 2.8 per patient were found to have plaques, respectively. Multi-vessel disease was more common than single vessel disease (p p p p p = 0.855. Extent of CAD, types of plaques and luminal narrowing were not significantly different between male and female diabetic patients. Conclusions Coronary CTA depicted a high plaque burden in patients with type 2 DM. Plaques, which were mainly calcified, were more frequently detected in the proximal segment of the LAD artery, and increased attention should be paid to the significant prevalence of obstructive stenosis. In addition, DM reduced the sex differential in CT findings of CAD.

Urease and Dental Plaque Microbial Profiles in Children.

Science.gov (United States)

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

2015-01-01

Urease enzymes produced by oral bacteria generate ammonia, which can have a significant impact on the oral ecology and, consequently, on oral health. To evaluate the relationship of urease with dental plaque microbial profiles in children as it relates to dental caries, and to identify the main contributors to this activity. 82 supragingival plaque samples were collected from 44 children at baseline and one year later, as part of a longitudinal study on urease and caries in children. DNA was extracted; the V3-V5 region of the 16S rRNA gene was amplified and sequenced using 454 pyrosequencing. Urease activity was measured using a spectrophotometric assay. Data were analyzed with Qiime. Plaque urease activity was significantly associated with the composition of the microbial communities of the dental plaque (Baseline P = 0.027, One Year P = 0.012). The bacterial taxa whose proportion in dental plaque exhibited significant variation by plaque urease levels in both visits were the family Pasteurellaceae (Baseline Purease and positively associated with dental caries (Bonferroni Purease enzymes primarily from species in the family Pasteurellaceae can be an important ecological determinant in children's dental plaque. Further studies are needed to establish the role of urease-associated bacteria in the acid/base homeostasis of the dental plaque, and in the development and prediction of dental caries in children.

Quantitative assessment of changes in carotid plaques during cilostazol administration using three-dimensional ultrasonography and non-gated magnetic resonance plaque imaging

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Mao; Ohba, Hideki; Mori, Kiyofumi; Narumi, Shinsuke; Katsura, Noriyuki; Ohura, Kazumasa; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto; Kudo, Kohsuke [Iwate Medical University, Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Morioka (Japan)

2012-09-15

Cilostazol, an antiplatelet agent, is reported to induce the regression of atherosclerotic changes. However, its effects on carotid plaques are unknown. Hence, we quantitatively investigated the changes that occur within carotid plaques during cilostazol administration using three-dimensional (3D) ultrasonography (US) and non-gated magnetic resonance (MR) plaque imaging. We prospectively examined 16 consecutive patients with carotid stenosis. 3D-US and T1-weighted MR plaque imaging were performed at baseline and 6 months after initiating cilostazol therapy (200 mg/day). We measured the volume and grayscale median (GSM) of the plaques from 3D-US data. We also calculated the contrast ratio (CR) of the carotid plaque against the adjacent muscle and areas of the intraplaque components: fibrous tissue, lipid, and hemorrhage components. The plaque volume on US decreased significantly (median at baseline and 6 months, 0.23 and 0.21 cm{sup 3}, respectively; p = 0.03). In the group exhibiting a plaque volume reduction of more than 10%, GSM on US increased significantly (24.8 and 71.5, respectively; p = 0.04) and CR on MRI decreased significantly (1.13 and 1.04, respectively; p = 0.02). In this group, in addition, the percent area of the fibrous component on MRI increased significantly (68.6% and 79.4%, respectively; p = 0.02), while those of the lipid and hemorrhagic components decreased (24.9% and 20.5%, respectively; p = 0.12) (1.0% and 0.0%, respectively; p = 0.04). There were no substantial changes in intraplaque characteristics in either US or MRI in the other group. 3D-US and MR plaque imaging can quantitatively detect changes in the size and composition of carotid plaques during cilostazol therapy. (orig.)

Tensile and compressive properties of fresh human carotid atherosclerotic plaques.

LENUS (Irish Health Repository)

Maher, Eoghan

2009-12-11

Accurate characterisation of the mechanical properties of human atherosclerotic plaque is important for our understanding of the role of vascular mechanics in the development and treatment of atherosclerosis. The majority of previous studies investigating the mechanical properties of human plaque are based on tests of plaque tissue removed following autopsy. This study aims to characterise the mechanical behaviour of fresh human carotid plaques removed during endarterectomy and tested within 2h. A total of 50 radial compressive and 17 circumferential tensile uniaxial tests were performed on samples taken from 14 carotid plaques. The clinical classification of each plaque, as determined by duplex ultrasound is also reported. Plaques were classified as calcified, mixed or echolucent. Experimental data indicated that plaques were highly inhomogeneous; with variations seen in the mechanical properties of plaque obtained from individual donors and between donors. The mean behaviour of samples for each classification indicated that calcified plaques had the stiffest response, while echolucent plaques were the least stiff. Results also indicated that there may be a difference in behaviour of samples taken from different anatomical locations (common, internal and external carotid), however the large variability indicates that more testing is needed to reach significant conclusions. This work represents a step towards a better understanding of the in vivo mechanical behaviour of human atherosclerotic plaque.

Added Sugar Consumption and Chronic Oral Disease Burden among Adolescents in Brazil.

Science.gov (United States)

Carmo, C D S; Ribeiro, M R C; Teixeira, J X P; Alves, C M C; Franco, M M; França, A K T C; Benatti, B B; Cunha-Cruz, J; Ribeiro, C C C

2018-05-01

Chronic oral diseases are rarely studied together, especially with an emphasis on their common risk factors. This study examined the association of added sugar consumption on "chronic oral disease burden" among adolescents, with consideration of obesity and systemic inflammation pathways through structural equation modeling. A cross-sectional study was conducted of a complex random sample of adolescent students enrolled at public schools in São Luís, Brazil ( n = 405). The outcome was chronic oral disease burden, a latent variable based on the presence of probing depth ≥4 mm, bleeding on probing, caries, and clinical consequences of untreated caries. The following hypotheses were tested: 1) caries and periodontal diseases among adolescents are correlated with each other; 2) added sugar consumption and obesity are associated with chronic oral disease burden; and 3) chronic oral disease burden is linked to systemic inflammation. Models were adjusted for socioeconomic status, added sugar consumption, oral hygiene behaviors, obesity, and serum levels of interleukin 6 (IL-6). All estimators of the latent variable chronic oral disease burden involved factor loadings ≥0.5 and P values disease burden values. Obesity was associated with high IL-6 levels (SC = 0.232, P = 0.001). Visible plaque index was correlated with chronic oral disease burden (SC = 0.381, P periodontal diseases are associated with each other and with added sugar consumption, obesity, and systemic inflammation reinforces the guidance of the World Health Organization that any approach intended to prevent noncommunicable diseases should be directed toward common risk factors.

Coronary CT Angiography in the Quantitative Assessment of Coronary Plaques

Directory of Open Access Journals (Sweden)

Zhonghua Sun

2014-01-01

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

Immunofluorescence Plaque Assay for African Swine Fever Virus

Science.gov (United States)

Tessler, J.; Hess, W. R.; Pan, I. C.; Trautman, R.

1974-01-01

Suitably diluted cell culture adapted African swine fever virus preparations were inoculated on VERO cell monolayers and grown on coverslips. Gum tragacanth was used as an overlay. After three days incubation at 37°C the infected cultures were fixed with acetone and stained with fluorescent antibody conjugate. Fluorescing plaques consisted of 20-30 infected cells. Three statistical criteria for a quantitatively reliable assay were met: the Poisson distribution for plaque counts, linearity of the relationship between the concentration of virus and the plaque count and reproducibility of replicate titrations. The method is suitable for counts up to at least 70 plaques per 5 cm2 coverslip and computed titers are reproducible within 0.16 log units with a total of 300 plaques enumerated. PMID:4279763

DECT evaluation of noncalcified coronary artery plaque

Energy Technology Data Exchange (ETDEWEB)

Ravanfar Haghighi, Rezvan [Medical Imaging Research Center and Colorectal Research Center, Shiraz University of Medical Science, Shiraz 719 363 5899 (Iran, Islamic Republic of); Chatterjee, S. [BGVS Chemical Engineering Building (Old), Indian Institute of Science, Bangalore 560012 (India); Tabin, Milo; Singh, Rishi P.; Sharma, Munish; Krishna, Karthik [Department of Forensic Medicine, All India Institute of Medical Sciences, New Delhi 110029 (India); Sharma, Sanjiv; Jagia, Priya [Department of Cardiac-Radiology, All India Institute of Medical Sciences, New Delhi 110029 (India); Ray, Ruma; Arava, Sudhir [Department of Pathology, All India Institute of Medical Sciences, New Delhi 110029 (India); Yadav, Rakesh [Department of Cardiology, All India Institute of Medical Sciences, New Delhi 110029 (India); Vani, V. C. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India); Lakshmi, R.; Kumar, Pratik, E-mail: drpratikkumar@gmail.com [Department of Cardiac-Biochemistry, All India Institute of Medical Sciences, New Delhi 110029 (India); Mandal, Susama R. [Department of Medical Physics Unit IRCH, All India Institute of Medical Sciences, New Delhi 110029 (India)

2015-10-15

Purpose: Composition of the coronary artery plaque is known to have critical role in heart attack. While calcified plaque can easily be diagnosed by conventional CT, it fails to distinguish between fibrous and lipid rich plaques. In the present paper, the authors discuss the experimental techniques and obtain a numerical algorithm by which the electron density (ρ{sub e}) and the effective atomic number (Z{sub eff}) can be obtained from the dual energy computed tomography (DECT) data. The idea is to use this inversion method to characterize and distinguish between the lipid and fibrous coronary artery plaques. Methods: For the purpose of calibration of the CT machine, the authors prepare aqueous samples whose calculated values of (ρ{sub e}, Z{sub eff}) lie in the range of (2.65 × 10{sup 23} ≤ ρ{sub e} ≤ 3.64 × 10{sup 23}/cm{sup 3}) and (6.80 ≤ Z{sub eff} ≤ 8.90). The authors fill the phantom with these known samples and experimentally determine HU(V{sub 1}) and HU(V{sub 2}), with V{sub 1},V{sub 2} = 100 and 140 kVp, for the same pixels and thus determine the coefficients of inversion that allow us to determine (ρ{sub e}, Z{sub eff}) from the DECT data. The HU(100) and HU(140) for the coronary artery plaque are obtained by filling the channel of the coronary artery with a viscous solution of methyl cellulose in water, containing 2% contrast. These (ρ{sub e}, Z{sub eff}) values of the coronary artery plaque are used for their characterization on the basis of theoretical models of atomic compositions of the plaque materials. These results are compared with histopathological report. Results: The authors find that the calibration gives ρ{sub e} with an accuracy of ±3.5% while Z{sub eff} is found within ±1% of the actual value, the confidence being 95%. The HU(100) and HU(140) are found to be considerably different for the same plaque at the same position and there is a linear trend between these two HU values. It is noted that pure lipid type plaques

Denitrification in human dental plaque

Directory of Open Access Journals (Sweden)

Verstraete Willy

2010-03-01

Full Text Available Abstract 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 can reduce this NO3- to nitrite (NO2-. Results We show that dental plaque mediates denitrification of NO3- to nitric oxide (NO, nitrous oxide (N2O, and dinitrogen (N2 using microsensor measurements, 15N isotopic labelling and molecular detection of denitrification genes. In vivo N2O accumulation rates in the mouth depended on the presence of dental plaque and on salivary NO3- concentrations. NO and N2O production by denitrification occurred under aerobic conditions and was regulated by plaque pH. Conclusions Increases of NO concentrations were in the range of effective concentrations for NO signalling to human host cells and, thus, may locally affect blood flow, signalling between nerves and inflammatory processes in the gum. This is specifically significant for the understanding of periodontal diseases, where NO has been shown to play a key role, but where gingival cells are believed to be the only source of NO. More generally, this study establishes denitrification by human-associated microbial communities as a significant metabolic pathway which, due to concurrent NO formation, provides a basis for symbiotic interactions.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Plaque reduction over time of an integrated oral hygiene system.

Science.gov (United States)

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

2004-10-01

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.

Vulnerable Plaque

Science.gov (United States)

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

An assessment of the vulnerability of carotid plaques: a comparative study between intraplaque neovascularization and plaque echogenicity

International Nuclear Information System (INIS)

Zhou, Yangyang; Li, Yan; Bai, Yang; Chen, Ying; Sun, Xiaofeng; Zhu, Yingqiao; Wu, Jiang

2013-01-01

Carotid plaque echolucency as detected by Color Doppler ultrasonography (CDUS) has been used as a potential marker of plaque vulnerability. However, contrast-enhanced ultrasound (CEUS) has recently been shown to be a valuable method to evaluate the vulnerability and neovascularization within carotid atherosclerotic plaques. The aim of this study was to compare CEUS and CDUS in the assessment of plaque vulnerability using transcranial color Doppler (TCD) monitoring of microembolic signals (MES) as a reference technique. A total of 46 subjects with arterial stenosis (≥ 50%) underwent a carotid duplex ultrasound, TCD monitoring of MES and CEUS (SonoVue doses of 2.0 mL) within a span of 3 days. The agreement between the CEUS, CDUS, and MES findings was assessed with a chi-square test. A p-value less than 0.05 was considered statistically significant. Neovascularization was observed in 30 lesions (44.4%). The vascular risk factors for stroke were similar and there were no age or gender differences between the 2 groups. Using CEUS, MES were identified in 2 patients (12.5%) within class 1 (non-neovascularization) as opposed to 15 patients (50.0%) within class 2 (neovascularization) (p = 0.023). CDUS revealed no significant differences in the appearance of the MES between the 2 groups (hyperechoic and hypoechoic) (p = 0.237). This study provides preliminary evidence to suggest that intraplaque neovascularization detected by CEUS is associated with the presence of MESs, where as plaque echogenicity on traditional CDUS does not. These findings argue that CEUS may better identify high-risk plaques

Advanced computed tomographic anatomical and morphometric plaque analysis for prediction of fractional flow reserve in intermediate coronary lesions

International Nuclear Information System (INIS)

Opolski, Maksymilian P.; Kepka, Cezary; Achenbach, Stephan; Pregowski, Jerzy; Kruk, Mariusz; Staruch, Adam D.; Kadziela, Jacek; Ruzyllo, Witold; Witkowski, Adam

2014-01-01

Objective: To determine the application of advanced coronary computed tomography angiography (CCTA) plaque analysis for predicting invasive fractional flow reserve (FFR) in intermediate coronary lesions. Methods: Sixty-one patients with 71 single intermediate coronary lesions (≥50–80% stenosis) on CCTA prospectively underwent coronary angiography and FFR. Advanced anatomical and morphometric plaque analysis was performed based on CCTA data set to determine optimal criteria for significant flow impairment. A significant stenosis was defined as FFR ≤ 0.80. Results: FFR averaged 0.85 ± 0.09, and 19 lesions (27%) were functionally significant. FFR correlated with minimum lumen area (MLA) (r = 0.456, p < 0.001), minimum lumen diameter (MLD) (r = 0.326, p = 0.006), reference lumen diameter (RLD) (r = 0.245, p = 0.039), plaque burden (r = −0.313, p = 0.008), lumen area stenosis (r = −0.305, p = 0.01), lesion length (r = −0.692, p < 0.001), and plaque volume (r = −0.668, p < 0.001). There was no relationship between FFR and CCTA morphometric plaque parameters. By multivariate analysis the independent predictors of FFR were lesion length (beta = −0.581, p < 0.001), MLA (beta = 0.360, p = 0.041), and RLD (beta = −0.255, p = 0.036). The optimal cutoffs for lesion length, MLA, MLD, RLD, and lumen area stenosis were >18.5 mm, ≤3.0 mm 2 , ≤2.1 mm, ≤3.2 mm, and >69%, respectively (max. sensitivity: 100% for MLA, max. specificity: 79% for lumen area stenosis). Conclusions: CCTA predictors for FFR support the mathematical relationship between stenosis pressure drop and coronary flow. CCTA could prove to be a useful rule-out test for significant hemodynamic effects of intermediate coronary stenoses

Dental plaque removal with a novel battery-powered toothbrush.

Science.gov (United States)

Biesbrock, Aaron R; Walters, Patricia; Bartizek, Robert D; Ruhlman, Douglas; Donly, Kevin J

2002-04-01

To compare the plaque removal efficacy of a positive control power toothbrush (Oral-B Ultra Plaque Remover) to an experimental power toothbrush (Crest SpinBrush) following a single use. This study was a randomized, controlled, examiner-blind, 2-period crossover design which examined plaque removal with the two toothbrushes following a single use in 38 completed subjects. Plaque was scored before and after brushing using the Turesky Modification of the Quigley-Hein Index. Baseline plaque scores were 1.89 and 1.91 for the experimental toothbrush and control toothbrush treatment groups, respectively. With respect to all surfaces examined, the experimental toothbrush delivered an adjusted (via analysis of covariance) mean difference between baseline and post-brushing plaque scores of 0.46 while the control toothbrush delivered an adjusted mean difference of 0.45. These results were not statistically significant (P=0.645). A 95% one-sided upper confidence limit on the Ultra Plaque Remover minus SpinBrush difference in amount of plaque removed was calculated as 9.4% of the Ultra Plaque Remover adjusted mean. A common criterion for what is known as an "at least as good as" test is that the 95% one-sided confidence limit on the product difference is below 10% of the control product mean. Using this criterion, the SpinBrush is at least as good as the Oral-B Ultra Plaque Remover. With respect to buccal and lingual surfaces, the experimental toothbrush delivered very similar results relative to the control toothbrush. These results were also not statistically significant (P> 0.564).

Plaque biology: interesting science or pharmacological treasure trove?

Science.gov (United States)

Loftus, I; Thompson, M

2008-11-01

Our understanding of the events that occur within atherosclerotic plaques has improved dramatically over the last 2 decades, particularly with regard to the role of plaque destabilisation and the onset of clinical ischaemic syndromes. Many potential targets have been identified for therapeutic intervention aimed at disease prevention, plaque stabilisation and regression. Furthermore, many potential biomarkers of vascular disease have generated interest in terms of monitoring disease activity and the effect of therapeutic agents. However, despite much scientific promise with in vitro cell and animal models, there has been much less success in modulation of these processes in clinical practice. This review will highlight the local and systemic factors associated with disease progression and acute plaque destabilisation, the current role of therapeutic agents and the potential for targeted plaque modification.

Low gray scale values of computerized images of carotid plaques associated with increased levels of triglyceride-rich lipoproteins and with increased plaque lipid content

DEFF Research Database (Denmark)

Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Weibe, Britt M.

1997-01-01

Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content......Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content...

Cholinergic degeneration is associated with increased plaque deposition and cognitive impairment in APPswe/PS1dE9 mice

DEFF Research Database (Denmark)

Laursen, Bettina; Mørk, Arne; Plath, Niels

2013-01-01

mice was not due to a more extensive cholinergic degeneration since the reduction in choline acetyltransferase activity was similar following SAP treatment in APP/PS1 mice and Wt. Interestingly, plaque load was significantly increased in SAP treated APP/PS1 mice relative to sham lesioned APP/PS1 mice....... Additionally, APP/PS1 mice treated with SAP showed a tendency towards an increased level of soluble and insoluble Aß1-40 and Aß1-42 measured in brain tissue homogenate. Our results suggest that the combination of cholinergic degeneration and Aß overexpression in the APP/PS1 mouse model results in cognitive...... decline and accelerated plaque burden. SAP treated APP/PS1 mice might thus constitute an improved model of Alzheimer's disease-like neuropathology and cognitive deficits compared to the conventional APP/PS1 model without selective removal of basal forebrain cholinergic neurons....

Characterization of atherosclerotic disease in thoracic aorta: A 3D, multicontrast vessel wall imaging study

Energy Technology Data Exchange (ETDEWEB)

Zhou, Changwu [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Department of Radiology, The Second Clinical Medical College, Yangzhou University, Yangzhou (China); Qiao, Huiyu; He, Le [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Yuan, Chun [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Department of Radiology, University of Washington, Seattle, WA (United States); Chen, Huijun; Zhang, Qiang; Li, Rui [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Wang, Wei; Du, Fang [Department of Radiology, The Second Clinical Medical College, Yangzhou University, Yangzhou (China); Li, Cheng, E-mail: cjr.licheng@vip.163.com [Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing (China); Zhao, Xihai, E-mail: xihaizhao@tsinghua.edu.cn [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China)

2016-11-15

Purpose: To investigate the characteristics of plaque in the thoracic aorta using three dimensional multicontrast magnetic resonance imaging. Materials and methods: Elderly subjects (≥60 years) were recruited in this study. Thoracic aorta was imaged on a 3.0T MR scanner by acquiring multicontrast sequences. The plaque burden was evaluated by measuring lumen area, wall area, wall thickness, and normalized wall index. The presence or absence of plaque and intraplaque hemorrhage (IPH)/mural thrombus (MT) were identified. The characteristics of atherosclerosis among different thoracic aorta segments (AAO: ascending aorta; AOA: aortic arch, and DOA: descending aorta) were determined. Results: Of 66 recruited subjects (mean age 72.3 ± 6.2 years, 30 males), 55 (83.3%) had plaques in the thoracic aorta. The prevalence of plaque in AAO, AOA, and DAO was 5.4%, 72.7%, and 71.2%, respectively. In addition, 21.2% of subjects were found to have lesions with IPH/MT in the thoracic aorta. The prevalence of IPH/MT in segment of AAO, AOA and DAO was 0%, 13.6%, and 12.1%, respectively. The aortic wall showed the highest NWI in DAO (34.1% ± 4.8%), followed by AOA (31.2% ± 5%), and AAO (26.8% ± 3.3%) (p < 0.001). Conclusion: Three dimensional multicontrast MR imaging is capable of characterizing atherosclerotic plaques in the thoracic aorta. The findings of high prevalence of plaques and the presence of high risk plaques in the thoracic aorta suggest early screening for aortic vulnerable lesions in the elderly.

Characterization of atherosclerotic disease in thoracic aorta: A 3D, multicontrast vessel wall imaging study

International Nuclear Information System (INIS)

Zhou, Changwu; Qiao, Huiyu; He, Le; Yuan, Chun; Chen, Huijun; Zhang, Qiang; Li, Rui; Wang, Wei; Du, Fang; Li, Cheng; Zhao, Xihai

2016-01-01

Purpose: To investigate the characteristics of plaque in the thoracic aorta using three dimensional multicontrast magnetic resonance imaging. Materials and methods: Elderly subjects (≥60 years) were recruited in this study. Thoracic aorta was imaged on a 3.0T MR scanner by acquiring multicontrast sequences. The plaque burden was evaluated by measuring lumen area, wall area, wall thickness, and normalized wall index. The presence or absence of plaque and intraplaque hemorrhage (IPH)/mural thrombus (MT) were identified. The characteristics of atherosclerosis among different thoracic aorta segments (AAO: ascending aorta; AOA: aortic arch, and DOA: descending aorta) were determined. Results: Of 66 recruited subjects (mean age 72.3 ± 6.2 years, 30 males), 55 (83.3%) had plaques in the thoracic aorta. The prevalence of plaque in AAO, AOA, and DAO was 5.4%, 72.7%, and 71.2%, respectively. In addition, 21.2% of subjects were found to have lesions with IPH/MT in the thoracic aorta. The prevalence of IPH/MT in segment of AAO, AOA and DAO was 0%, 13.6%, and 12.1%, respectively. The aortic wall showed the highest NWI in DAO (34.1% ± 4.8%), followed by AOA (31.2% ± 5%), and AAO (26.8% ± 3.3%) (p < 0.001). Conclusion: Three dimensional multicontrast MR imaging is capable of characterizing atherosclerotic plaques in the thoracic aorta. The findings of high prevalence of plaques and the presence of high risk plaques in the thoracic aorta suggest early screening for aortic vulnerable lesions in the elderly.

Cobalt60 plaques in recurrent retinoblastoma

Energy Technology Data Exchange (ETDEWEB)

Fass, D.; McCormick, B.; Abramson, D.; Ellsworth, R. (Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, NY, NY (USA))

1991-08-01

Cobalt60 plaque irradiation is one treatment option for patients with recurrent retinoblastoma following conventional external beam irradiation (ERT). Tumorocidal doses can be delivered without excessive risk of normal tissue injury. In patients not considered candidates for xenon arc or cryotherapy, 60Co is an alternative to enucleation. Between 1968 and 1987, 85 patients were treated with 60Co plaques, 72 of whom had failed prior ERT. Age at diagnosis ranged from 1 week to 4 years. There are 37 males and 35 females. Seventy-one patients had bilateral disease and one had unilateral. Three patients had both eyes plaqued. Prior ERT ranged from 30 to 70 Gy (mean 4200 Gy). Time from initial therapy to failure ranged from 13 to 60 months. Cobalt plaques of 10 mm, 15 mm, or 10 {times} 15 mm were used depending on tumor size and location. Dose prescribed to the apex of the tumor ranged from 30 to 50 Gy (median 40 Gy) given over 3 to 8 days. Twelve patients had two plaque applications; three patients had three plaque applications. All patients were followed with routine ophthalmoscopic examinations. Follow-up ranged from 2 to 22 years (mean 8.7). Seven patients died of metastatic disease; 10 patients developed non-ocular second tumors. Thirty patients required enucleation. Twenty-two patients had clear tumor progression, two patients had radiation complications, and six patients had a combination of tumor growth and complications. Cobalt60 can salvage eyes in retinoblastoma patients failing ERT. Currently, the authors are using I125 in an attempt to spare normal ocular tissue and reduce subsequent complications.

Cobalt60 plaques in recurrent retinoblastoma

International Nuclear Information System (INIS)

Fass, D.; McCormick, B.; Abramson, D.; Ellsworth, R.

1991-01-01

Cobalt60 plaque irradiation is one treatment option for patients with recurrent retinoblastoma following conventional external beam irradiation (ERT). Tumorocidal doses can be delivered without excessive risk of normal tissue injury. In patients not considered candidates for xenon arc or cryotherapy, 60Co is an alternative to enucleation. Between 1968 and 1987, 85 patients were treated with 60Co plaques, 72 of whom had failed prior ERT. Age at diagnosis ranged from 1 week to 4 years. There are 37 males and 35 females. Seventy-one patients had bilateral disease and one had unilateral. Three patients had both eyes plaqued. Prior ERT ranged from 30 to 70 Gy (mean 4200 Gy). Time from initial therapy to failure ranged from 13 to 60 months. Cobalt plaques of 10 mm, 15 mm, or 10 x 15 mm were used depending on tumor size and location. Dose prescribed to the apex of the tumor ranged from 30 to 50 Gy (median 40 Gy) given over 3 to 8 days. Twelve patients had two plaque applications; three patients had three plaque applications. All patients were followed with routine ophthalmoscopic examinations. Follow-up ranged from 2 to 22 years (mean 8.7). Seven patients died of metastatic disease; 10 patients developed non-ocular second tumors. Thirty patients required enucleation. Twenty-two patients had clear tumor progression, two patients had radiation complications, and six patients had a combination of tumor growth and complications. Cobalt60 can salvage eyes in retinoblastoma patients failing ERT. Currently, the authors are using I125 in an attempt to spare normal ocular tissue and reduce subsequent complications

Approach To Unstable Plaque In Carotid Disease

Directory of Open Access Journals (Sweden)

Mojdeh Ghabaee

2017-02-01

Full Text Available Risk of cerebral infarction due to thrombo emboli originating  from carotid artery disease estimated to be near 15%, and this risk  is closely associated with the severity of luminal stenosis. But at the same time characteristics  of the plaque should be taken into account for therapeutic planning when the patient is asymptomatic and the diameter of the stenosis does not reach the threshold of 70%. Search for markers of plaque vulnerability, instability, or thromboembolic potential as complementary to the degree of the luminal stenosis in stroke risk prediction should be considered .These morphologic features of carotid plaques are increasingly believed to be one of those markers that could carry further prognostic information, and early recognition of these plaques features may identify a high-risk subgroup of patients who might particularly benefit from aggressive interventions with aggressive medical treatment. Color and duplex Doppler sonography  evaluates both  morphologic and hemodynamic   abnormalitie of carotid. Echogensity, degree of stenosis and plaque surface features are essential parameters of morphological abnormality.

3D Isotropic MR Culprit Plaque Visualization of Carotid Plaque Edema and Hemorrhage with Motion Sensitized Blood Suppression

DEFF Research Database (Denmark)

Søvsø Szocska Hansen, Esben; Pedersen, Steen Fjord; Bloch, Lars Ø.

2014-01-01

hemorrhage and plaque edema may represent advanced stages of atherosclerosis[1, 2]. In this study, we present a novel multi-contrast 3D motion sensitized black-blood CMR imaging sequence, which detects both plaque edema and hemorrhage with positive contrast. Subjects and Methods The 3D imaging sequence...... to lumen was 39.74±6.75. Discussion/Conclusion In conclusion, the proposed 3D isotropic multi-contrast CMR technique detects plaque edema and hemorrhage with positive contrast and excellent black-blood contrast, which may facilitate evaluation of carotid atherosclerosis. Ongoing studies will include CMR...

Assessment of carotid plaque vulnerability using structural and geometrical determinants

International Nuclear Information System (INIS)

Li, Z.Y.; Tang, T.; U-King-Im, J.; Graves, M.; Gillard, J.H.; Sutcliffe, M.

2008-01-01

Because many acute cerebral ischemic events are caused by rupture of vulnerable carotid atheroma and subsequent thrombosis, the present study used both idealized and patient-specific carotid atheromatous plaque models to evaluate the effect of structural determinants on stress distributions within plaque. Using a finite element method, structural analysis was performed using models derived from in vivo high-resolution magnetic resonance imaging (MRI) of carotid atheroma in 40 non-consecutive patients (20 symptomatic, 20 asymptomatic). Plaque components were modeled as hyper-elastic materials. The effects of varying fibrous cap thickness, lipid core size and lumen curvature on plaque stress distributions were examined. Lumen curvature and fibrous cap thickness were found to be major determinants of plaque stress. The size of the lipid core did not alter plaque stress significantly when the fibrous cap was relatively thick. The correlation between plaque stress and lumen curvature was significant for both symptomatic (p=0.01; correlation coefficient: 0.689) and asymptomatic patients (p=0.01; correlation coefficient: 0.862). Lumen curvature in plaques of symptomatic patients was significantly larger than those of asymptomatic patients (1.50±1.0 mm -1 vs 1.25±0.75 mm -1 ; p=0.01). Specific plaque morphology (large lumen curvature and thin fibrous cap) is closely related to plaque vulnerability. Structural analysis using high-resolution MRI of carotid atheroma may help in detecting vulnerable atheromatous plaque and aid the risk stratification of patients with carotid disease. (author)

Contemporary perspective on plaque control.

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Marsh, P D

2012-06-22

The aim of this review article is to provide a scientific platform that will enable the dental team to develop a rational approach to plaque control based on the latest knowledge of the role of the oral microflora in health and disease. The resident oral microflora is natural and forms spatially-organised, interactive, multi-species biofilms on mucosal and dental surfaces in the mouth. These resident oral microbial communities play a key function in the normal development of the physiology of the host and are important in preventing colonisation by exogenous and often undesirable microbes. A dynamic balance exists between the resident microflora and the host in health, and disease results from a breakdown of this delicate relationship. Patients should be taught effective plaque control techniques that maintain dental biofilms at levels compatible with oral health so as to retain the beneficial properties of the resident microflora while reducing the risk of dental disease from excessive plaque accumulation. Antimicrobial and antiplaque agents in oral care products can augment mechanical plaque control by several direct and indirect mechanisms that not only involve reducing or removing dental biofilms but also include inhibiting bacterial metabolism when the agents are still present at sub-lethal concentrations.

Spectral CT of carotid atherosclerotic plaque: comparison with histology

Energy Technology Data Exchange (ETDEWEB)

Zainon, R.; Doesburg, R.M. [University of Canterbury, Department of Physics and Astronomy, Christchurch (New Zealand); Ronaldson, J.P.; Gieseg, S.P. [University of Otago, Centre for Bioengineering, Christchurch (New Zealand); Janmale, T. [University of Canterbury, Free Radical Biochemistry Laboratory, School of Biological Sciences, Christchurch (New Zealand); Scott, N.J. [University of Otago, Department of Medicine, Christchurch (New Zealand); Buckenham, T.M. [University of Otago, Department of Academic Radiology, Christchurch (New Zealand); Butler, A.P.H. [University of Otago, Centre for Bioengineering, Christchurch (New Zealand); University of Otago, Department of Academic Radiology, Christchurch (New Zealand); University of Canterbury, Department of Electrical and Computer Engineering, Christchurch (New Zealand); European Organisation for Nuclear Research (CERN), Geneva (Switzerland); Butler, P.H. [University of Canterbury, Department of Physics and Astronomy, Christchurch (New Zealand); European Organisation for Nuclear Research (CERN), Geneva (Switzerland); Roake, J.A. [Christchurch Hospital, Department of Vascular, Endovascular and Transplant Surgery, Christchurch (New Zealand); Anderson, N.G. [University of Otago, Centre for Bioengineering, Christchurch (New Zealand); University of Otago, Department of Academic Radiology, Christchurch (New Zealand); University of Otago, Christchurch, Department of Radiology, PO Box 4345, Christchurch (New Zealand)

2012-12-15

To distinguish components of vulnerable atherosclerotic plaque by imaging their energy response using spectral CT and comparing images with histology. After spectroscopic calibration using phantoms of plaque surrogates, excised human carotid atherosclerotic plaques were imaged using MARS CT using a photon-processing detector with a silicon sensor layer and microfocus X-ray tube (50 kVp, 0.5 mA) at 38-{mu}m voxel size. The plaques were imaged, sectioned and re-imaged using four threshold energies: 10, 16, 22 and 28 keV; then sequentially stained with modified Von Kossa, Perl's Prussian blue and Oil-Red O, and photographed. Relative Hounsfield units across the energies were entered into a linear algebraic material decomposition model to identify the unknown plaque components. Lipid, calcium, iron and water-like components of plaque have distinguishable energy responses to X-ray, visible on spectral CT images. CT images of the plaque surface correlated very well with histological photographs. Calcium deposits (>1,000 {mu}m) in plaque are larger than iron deposits (<100 {mu}m), but could not be distinguished from each other within the same voxel using the energy range available. Spectral CT displays energy information in image form at high spatial resolution, enhancing the intrinsic contrast of lipid, calcium and iron within atheroma. (orig.)

HDL and CER-001 Inverse-Dose Dependent Inhibition of Atherosclerotic Plaque Formation in apoE-/- Mice: Evidence of ABCA1 Down-Regulation.

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Tardy, Claudine; Goffinet, Marine; Boubekeur, Nadia; Cholez, Guy; Ackermann, Rose; Sy, Gavin; Keyserling, Constance; Lalwani, Narendra; Paolini, John F; Dasseux, Jean-Louis; Barbaras, Ronald; Baron, Rudi

2015-01-01

CER-001 is a novel engineered HDL-mimetic comprised of recombinant human apoA-I and charged phospholipids that was designed to mimic the beneficial properties of nascent pre-ß HDL. In this study, we have evaluated the dose-dependent regulation of ABCA1 expression in vitro and in vivo in the presence of CER-001 and native HDL (HDL3). CER-001 induced cholesterol efflux from J774 macrophages in a dose-dependent manner similar to natural HDL. A strong down-regulation of the ATP-binding cassette A1 (ABCA1) transporter mRNA (- 50%) as well as the ABCA1 membrane protein expression (- 50%) was observed at higher doses of CER-001 and HDL3 compared to non-lipidated apoA-I. In vivo, in an apoE-/- mouse "flow cessation model," in which the left carotid artery was ligatured to induce local inflammation, the inhibition of atherosclerotic plaque burden progression in response to a dose-range of every-other-day CER-001 or HDL in the presence of a high-fat diet for two weeks was assessed. We observed a U-shaped dose-response curve: inhibition of the plaque total cholesterol content increased with increasing doses of CER-001 or HDL3 up to a maximum inhibition (- 51%) at 5 mg/kg; however, as the dose was increased above this threshold, a progressively less pronounced inhibition of progression was observed, reaching a complete absence of inhibition of progression at doses of 20 mg/kg and over. ABCA1 protein expression in the same atherosclerotic plaque was decreased by-45% and-68% at 50 mg/kg for CER-001 and HDL respectively. Conversely, a-12% and 0% decrease in ABCA1 protein expression was observed at the 5 mg/kg dose for CER-001 and HDL respectively. These data demonstrate that high doses of HDL and CER-001 are less effective at slowing progression of atherosclerotic plaque in apoE-/- mice compared to lower doses, following a U-shaped dose-response curve. A potential mechanism for this phenomenon is supported by the observation that high doses of HDL and CER-001 induce a rapid and

18FDG PET and ultrasound echolucency in carotid artery plaques

DEFF Research Database (Denmark)

Graebe, Martin; Pedersen, Sune F; Højgaard, Liselotte

2010-01-01

OBJECTIVES: The objective was to evaluate inflammation in echolucent carotid artery plaques. BACKGROUND: Ultrasound echolucency of carotid artery plaques has been proven to differentiate patients at high risk of stroke. On the other hand, positron emission tomography (PET) of plaques with the use...... for ultrasound and PET imaging. Plaque standardized gray scale medians (GSM) were measured in longitudinal ultrasound images to quantitate echolucency, and GSM values were compared with FDG PET uptake quantified by maximum standardized uptake values (SUV). Symptomatic plaques were compared with contralateral...... plaques ranged from high to low inflammatory activity, as depicted with PET. Quantitative FDG SUV differentiated asymptomatic from symptomatic plaques, whereas GSM values did not. There was a positive correlation between CD68 expression and FDG uptake (r = 0.50, p = 0.04). CONCLUSIONS: Our results...

Value of the lateral view in diagnosing pleural plaques

International Nuclear Information System (INIS)

Hillerdal, G.

1986-01-01

To assess the value of the lateral view in the diagnosis of pleural plaques, 2018 chest roentgenograms from the general population were scrutinized for such plaques. The lateral and posterior-anterior (PA) views were read separately and without knowledge of the occupational history or other clinical data. Of the males, 4.8% had pleural plaques in the PA view and 2% had dorsal pleural plaques in the lateral view. A total of 54% of the positive cases in the PA view also showed typical plaques in the PA view. Thus, there remained a number of cases which were diagnosed only in the lateral view; in all, these constituted 18.8%

Carotid artery plaque imaging. Present status and new perspectives

International Nuclear Information System (INIS)

Hishikawa, Tomohito; Date, Isao; Iihara, Koji; Yamada, Naoaki; Ueda, Hatsue; Nagatsuka, Kazuyuki; Miyamoto, Susumu

2010-01-01

At present, the management of carotid artery (CA) stenosis depends largely on the degree of stenosis. CA plaque imaging is a modality, which assesses the nature of CA plaques objectively and less invasively, that has developed remarkably in recent years. The use of CA plaque imaging in the management of CA stenosis not only reveals the degree of stenosis but it can make the selection of treatment more appropriate by taking the plaque character into consideration. In this manuscript, we introduce ultrasound, intravascular ultrasound, angiography, magnetic resonance imaging (MRI), positron emission tomography (PET) and computed tomography (CT) and describe the present situation and new perspectives of CA plaque imaging. (author)

Three-dimensional carotid ultrasound plaque texture predicts vascular events

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van Engelen, Arna; Wannarong, Thapat; Parraga, Grace

2014-01-01

BACKGROUND AND PURPOSE: Carotid ultrasound atherosclerosis measurements, including those of the arterial wall and plaque, provide a way to monitor patients at risk of vascular events. Our objective was to examine carotid ultrasound plaque texture measurements and the change in carotid plaque text...

The significance of early post-exercise ST segment normalization.

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Chow, Rudy; Fordyce, Christopher B; Gao, Min; Chan, Sammy; Gin, Kenneth; Bennett, Matthew

2015-01-01

The persistence of ST segment depression in recovery signifies a strongly positive exercise treadmill test (ETT). However, it is unclear if early recovery of ST segments portends a similar prognosis. We sought to determine if persistence of ST depression into recovery correlates with ischemic burden based on myocardial perfusion imaging (MPI). This was a retrospective analysis of 853 consecutive patients referred for exercise MPI at a tertiary academic center over a 24-month period. Patients were stratified into three groups based on the results of the ETT: normal (negative ETT), persistence (positive ETT with >1mm ST segment depression at 1minute in recovery) and early normalization (positive ETT with normalization, while 105 patients met criteria for persistence. The persistence group had a significantly greater SSS (8.48±7.77) than both the early normalization (4.34±4.98, pnormal (4.47±5.31, pnormalization and normal groups were not statistically different and met the prespecified non-inferiority margin (mean difference 0.12, -0.66=lower 95% CI, pnormal and 7.4% of early normalization groups. Among patients with an electrically positive ETT, recovery of ST segment depression within 1minute was associated with a lower SSS than patients with persistence of ST depression beyond 1minute. Furthermore, early ST segment recovery conferred a similar SSS to patients with a negative ETT. These results suggest that among patients evaluated for chest pain with a positive ETT, early recovery of the ST segment during recovery is associated with a significantly less ischemic burden on subsequent MPI and thus may represent a false positive finding in exercise treadmill testing. Copyright © 2015 Elsevier Inc. All rights reserved.

New low-viscosity overlay medium for viral plaque assays

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Garten Wolfgang

2006-08-01

Full Text Available Abstract Background Plaque assays in cell culture monolayers under solid or semisolid overlay media are commonly used for quantification of viruses and antiviral substances. To overcome the pitfalls of known overlays, we tested suspensions of microcrystalline cellulose Avicel RC/CL™ as overlay media in the plaque and plaque-inhibition assay of influenza viruses. Results Significantly larger plaques were formed under Avicel-containing media, as compared to agar and methylcellulose (MC overlay media. The plaque size increased with decreasing Avicel concentration, but even very diluted Avicel overlays (0.3% ensured formation of localized plaques. Due to their low viscosity, Avicel overlays were easier to use than methylcellulose overlays, especially in the 96-well culture plates. Furthermore, Avicel overlay could be applied without prior removal of the virus inoculum thus facilitating the assay and reducing chances of cross-contamination. Using neuraminidase inhibitor oseltamivir carboxylate, we demonstrated applicability of the Avicel-based plaque reduction assay for testing of antiviral substances. Conclusion Plaque assay under Avicel-containing overlay media is easier, faster and more sensitive than assays under agar- and methylcellulose overlays. The assay can be readily performed in a 96-well plate format and seems particularly suitable for high-throughput virus titrations, serological studies and experiments on viral drug sensitivity. It may also facilitate work with highly pathogenic agents performed under hampered conditions of bio-safety labs.

Optical coherence tomography plaque characterization in a patient with ST segment elevation myocardial infarction after cocaine intake

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Hansen, Morten; Antonsen, L.; Jensen, L. O.

2016-01-01

A 28-year old man presented to the Emergency Department with malaise after cocaine intake. After arrival he developed retrosternal chest pain and the electrocardiogram showed ST segment elevations in V1-V2 and ST segment depressions in V5-V6. An acute coronary angiogram revealed a focal non...

Quantification of iron in the presence of calcium with dual-energy computed tomography (DECT) in an ex vivo porcine plaque model

International Nuclear Information System (INIS)

Wang Jia; Duan Xinhui; Leng Shuai; Yu Lifeng; McCollough, Cynthia H; Garg, Nitin; Liu Yu; Kantor, Birgit; Ritman, Erik L

2011-01-01

Iron deposits secondary to microbleeds often co-exist with calcium in coronary plaques. The purpose of this study was to quantify iron in the presence of calcium in an ex vivo porcine arterial plaque model using a clinical dual-energy CT (DECT) scanner. A material decomposition method to quantify the mass fractions of iron and calcium within a mixture using DECT was developed. Mixture solutions of known iron and calcium concentrations were prepared to calibrate and validate the DECT-based algorithm. Simulated plaques with co-existing iron and calcium were created by injecting the mixture solutions into the vessel wall of porcine carotid arteries and aortas. These vessel regions were harvested and scanned using a clinical DECT system and iron mass fraction was calculated for each sample. Iron- and calcium-specific staining was conducted on 5 µm thick histological sections of vessel samples to confirm the co-existence of iron and calcium in the simulated plaques. The proposed algorithm accurately quantified iron and calcium amounts in mixture solutions. Maps of iron mass fraction of 60 artery segments were obtained from CT images at two energies. The sensitivity for detecting the presence of iron was 83% and the specificity was 92% using a threshold at an iron mass fraction of 0.25%. Histological analysis confirmed the co-localization of iron and calcium within the simulated plaques. Iron quantification in the presence of calcium was feasible in excised arteries at an iron mass fraction of around 1.5% or higher using current clinical DECT scanners.

La pelade par plaques

Science.gov (United States)

Spano, Frank; Donovan, Jeff C.

2015-01-01

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

Release of mineral ions in dental plaque following acid production.

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Tanaka, M; Margolis, H C

1999-03-01

The release of appreciable amounts of calcium, phosphate and fluoride found in whole plaque into the plaque-fluid phase, following bacterial acid production, can potentially reduce the driving force for tooth demineralization. However, limited information is available on this topic, particularly on the release of fluoride. This study sought to determine the change in calcium, phosphate and fluoride concentrations in plaque fluid after sucrose exposure. 48 h overnight-fasted supragingival plaque samples were collected from all tooth surfaces (with the exception of the lower lingual anterior teeth) of one half of an individual mouth, following a 1 min water rinse. Plaque samples were then collected from the other half of the same mouth, following a 292 mM sucrose rinse. Plaque fluid was isolated by centrifugation and analysed for total calcium and phosphate (ion chromatography) and for free fluoride (ion-specific electrode). Samples were collected from seven individuals. Following sucrose exposure, plaque-fluid pH decreased significantly from 6.5+/- 0.3 to 5.4+/-0.2; calcium concentrations (mmol/l) also increased significantly (p Fluoride and phosphate concentrations in plaque fluid, however, did not increase significantly after sucrose exposure: mean concentrations (mmol/l) of fluoride after the water and sucrose rinses were 0.006+/-0.003 and 0.005+/-0.002, respectively, and mean phosphate concentrations (mmol/l) were 11.0+/-2.0 and 12.0+/-3.0, respectively. When results were expressed per wet plaque weight, phosphate concentrations were also found to increase significantly. The same trends were observed when additional plaque samples were treated in vitro with sucrose: fluoride-ion activity did not increase in plaque under in vivo-like conditions.

Image segmentation evaluation for very-large datasets

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Reeves, Anthony P.; Liu, Shuang; Xie, Yiting

2016-03-01

With the advent of modern machine learning methods and fully automated image analysis there is a need for very large image datasets having documented segmentations for both computer algorithm training and evaluation. Current approaches of visual inspection and manual markings do not scale well to big data. We present a new approach that depends on fully automated algorithm outcomes for segmentation documentation, requires no manual marking, and provides quantitative evaluation for computer algorithms. The documentation of new image segmentations and new algorithm outcomes are achieved by visual inspection. The burden of visual inspection on large datasets is minimized by (a) customized visualizations for rapid review and (b) reducing the number of cases to be reviewed through analysis of quantitative segmentation evaluation. This method has been applied to a dataset of 7,440 whole-lung CT images for 6 different segmentation algorithms designed to fully automatically facilitate the measurement of a number of very important quantitative image biomarkers. The results indicate that we could achieve 93% to 99% successful segmentation for these algorithms on this relatively large image database. The presented evaluation method may be scaled to much larger image databases.

Inner and outer coronary vessel wall segmentation from CCTA using an active contour model with machine learning-based 3D voxel context-aware image force

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Sivalingam, Udhayaraj; Wels, Michael; Rempfler, Markus; Grosskopf, Stefan; Suehling, Michael; Menze, Bjoern H.

2016-03-01

In this paper, we present a fully automated approach to coronary vessel segmentation, which involves calcification or soft plaque delineation in addition to accurate lumen delineation, from 3D Cardiac Computed Tomography Angiography data. Adequately virtualizing the coronary lumen plays a crucial role for simulating blood ow by means of fluid dynamics while additionally identifying the outer vessel wall in the case of arteriosclerosis is a prerequisite for further plaque compartment analysis. Our method is a hybrid approach complementing Active Contour Model-based segmentation with an external image force that relies on a Random Forest Regression model generated off-line. The regression model provides a strong estimate of the distance to the true vessel surface for every surface candidate point taking into account 3D wavelet-encoded contextual image features, which are aligned with the current surface hypothesis. The associated external image force is integrated in the objective function of the active contour model, such that the overall segmentation approach benefits from the advantages associated with snakes and from the ones associated with machine learning-based regression alike. This yields an integrated approach achieving competitive results on a publicly available benchmark data collection (Rotterdam segmentation challenge).

Collagen and related extracellular matrix proteins in atherosclerotic plaque development.

Science.gov (United States)

Shami, Annelie; Gonçalves, Isabel; Hultgårdh-Nilsson, Anna

2014-10-01

The structure, composition and turnover of the extracellular matrix (ECM) as well as cell-matrix interactions are crucial in the developing atherosclerotic plaque. There is a need for further insight into specific proteins in the ECM and their functions in the developing plaque, and during the last few years a number of publications have highlighted this very important field of research. These novel findings will be addressed in the present review. This review covers literature focused on collagen and ECM proteins interacting with collagen, and what their roles may be in plaque development. Acute myocardial infarction and stroke are common diseases that cause disability and mortality, and the underlying mechanism is often the rupture of a vulnerable atherosclerotic plaque. The vascular ECM and the tissue repair in the atherosclerotic lesion are important players in plaque progression. Understanding how specific proteins in the ECM interact with cells in the plaque and affect the fate of the plaque can lead to new treatments for cardiovascular disease.

Reliability and discriminatory power of methods for dental plaque quantification

Directory of Open Access Journals (Sweden)

Daniela Prócida Raggio

2010-04-01

Full Text Available OBJECTIVE: This in situ study evaluated the discriminatory power and reliability of methods of dental plaque quantification and the relationship between visual indices (VI and fluorescence camera (FC to detect plaque. MATERIAL AND METHODS: Six volunteers used palatal appliances with six bovine enamel blocks presenting different stages of plaque accumulation. The presence of plaque with and without disclosing was assessed using VI. Images were obtained with FC and digital camera in both conditions. The area covered by plaque was assessed. Examinations were done by two independent examiners. Data were analyzed by Kruskal-Wallis and Kappa tests to compare different conditions of samples and to assess the inter-examiner reproducibility. RESULTS: Some methods presented adequate reproducibility. The Turesky index and the assessment of area covered by disclosed plaque in the FC images presented the highest discriminatory powers. CONCLUSION: The Turesky index and images with FC with disclosing present good reliability and discriminatory power in quantifying dental plaque.

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

International Nuclear Information System (INIS)

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

1985-01-01

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 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 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 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

Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients.

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Otten, Marieke P T; Busscher, Henk J; Abbas, Frank; van der Mei, Henny C; van Hoogmoed, Chris G

2012-10-01

Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims. First, volunteers brushed 2 weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12 h after brushing and bacterial concentrations and viabilities were measured. The contributions of plaque and saliva towards substantivity were determined by combining control plaques with experimental plaque or saliva samples and subsequently assessing their viabilities. Bacterial compositions in the various plaque and saliva samples were compared using denaturing gradient gel electrophoresis. The viabilities of plaques after brushing with Colgate-Total® and Crest-Pro-Health® were smaller than of control plaques and up to 12 h after brushing with Crest-Pro-Health® plaques still contained effective, residual antibacterial activity against control plaques. No effective, residual antibacterial activity could be measured in saliva samples after brushing. There was no significant difference in bacterial composition of plaque or saliva after brushing with the different toothpastes. Plaque-left-behind after mechanical cleaning contributes to the substantive action of an antibacterial toothpaste containing stannous fluoride (Crest-Pro-Health®). The absorptive capacity of plaque-left-behind after brushing is of utmost clinical importance, since plaque is predominantly left behind in places where its removal and effective killing matter most. Therewith this study demonstrates a clear and new beneficial effect of the use of antibacterial toothpastes.

Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

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Nageshwar Iyer

2016-01-01

Full Text Available Aim: The aim of this clinical study was to confirm the plaque removal efficacy of the Colgate 360 Whole Mouth Clean Toothbrush. Study Design: This was a single-center, monadic, case-controlled study with the 7 days duration. Materials and Methods: A total of eighty participants (56 male and 24 female aged between 18 and 45 years with a minimum of 20 permanent teeth (excluding the third molars without any prosthetic crowns and an initial plaque score of minimum 1.5 as determined by Modified Quigley-Hein Plaque Index (1970 participated in the study. There were two dropouts during the study duration, one male and one female. The participants were instructed to brush for 1 min, after which plaque index was recorded again. They were then instructed to brush their teeth twice a day for 1 min with the assigned toothbrush (Colgate 360 Whole Mouth Clean Toothbrush and a commercially available fluoride toothpaste for the next 7 days. On the 7 th day, all the participants were recalled for follow-up and plaque examination. The plaque index scores (pre- and post-brushing were recorded, tabulated, and analyzed statistically. Results: The mean plaque indices reduced after brushing both on day 1 and day 7. There was also a reduction in mean plaque indices from day 1 to day 7. All these reductions were statistically significant (P < 0.001. The reduction in plaque scores was independent of the gender of the participants however female participants showed lower scores as compared to male participants (P < 0.001. Conclusion: The present study demonstrated a significant reduction in plaque scores with the use of Colgate 360 Whole Mouth Clean Soft Toothbrush throughout the study period. Continued use resulted in a further significant reduction in plaque scores irrespective of the gender of participants.

High shear stress relates to intraplaque haemorrhage in asymptomatic carotid plaques

DEFF Research Database (Denmark)

Tuenter, A.; Selwaness, M.; Arias Lorza, A.

2016-01-01

estimating equations analysis, adjusting for age, sex and carotid wall thickness. RESULTS: The study group consisted of 93 atherosclerotic carotid arteries of 74 participants. In plaques with higher maximum shear stresses, IPH was more often present (OR per unit increase in maximum shear stress (log......BACKGROUND AND AIMS: Carotid artery plaques with vulnerable plaque components are related to a higher risk of cerebrovascular accidents. It is unknown which factors drive vulnerable plaque development. Shear stress, the frictional force of blood at the vessel wall, is known to influence plaque...... formation. We evaluated the association between shear stress and plaque components (intraplaque haemorrhage (IPH), lipid rich necrotic core (LRNC) and/or calcifications) in relatively small carotid artery plaques in asymptomatic persons. METHODS: Participants (n = 74) from the population-based Rotterdam...

Monte Carlo generation of dosimetric parameters for eye plaque dosimetry

International Nuclear Information System (INIS)

Cutajar, D.L.; Green, J.A.; Guatelli, S.; Rosenfeld, A.B.

2010-01-01

Full text: The Centre for Medical Radiation Physics have undertaken the dcvelopment of a quality assurance tool, using silicon pixelated detectors, for the calibration of eye plaques prior to insertion. Dosimetric software to correlate the measured and predicted dose rates has been constructed. The dosimetric parameters within the software, for both 1-125 and Ru-I 06 based eye plaques, were optimised using the Geant4 Monte Carlo toolkit. Methods For 1-125 based plaques, an novel application was developed to generate TG-43 parameters for any seed input. TG-43 parameters were generated for an Oncura model 6711 seed, with data points every millimetre up to 25 mm in the radial direction, and every 5 degrees in polar angle, and correlated to published data. For the Ru106 based plaques, an application was developed to generate dose rates about a Bebig model CCD plaque. Toroids were used to score the deposited dose, taking advantage of the cylindrical symmetry of the plaque, with radii in millimetre increments up to 25 mm, and depth from the plaque surface in millimetre increments up to 25 mm. Results TheTG43 parameters generated for the 6711 seed correlate well with published TG43 data at the given intervals, with radial dose function within 3%, and anisotropy function within 5% for angles greater than 30 degrees. The Ru-l 06 plaque data correlated well with the Bebig protocol of measurement. Conclusion Geant4 is a useful Monte Carlo tool for the generation of dosimetric data for eye plaque dosimetry. which may improve the quality assurance of eye plaque treatment. (author)

Non-calcified coronary plaque volume inversely related to CD4 count in HIV infection

Science.gov (United States)

Duarte, Horacio; Matta, Jatin R.; Muldoon, Nancy; Masur, Henry; Hadigan, Colleen; Gharib, Ahmed M.

2013-01-01

Background Non-calcified coronary artery plaque (NCAP) may be an important predictor of cardiovascular events, however, few studies have directly measured NCAP in HIV-infected individuals. Methods We completed a prospective cross-sectional evaluation of NCAP and coronary calcium scores using CT angiography in HIV-infected subjects (n=26) without known coronary artery disease (CAD), but who had one or more CAD risk factor and compared them to controls matched on age, race, sex, body mass index and Framingham risk score (n=26). Results There was no difference in coronary calcium scores (114 ± 218 vs. 124 ± 298 p=0.89) or NCAP volume (65 ± 86 mm3 vs. 63 ± 82 mm3, p=0.38) between HIV-infected subjects and controls, respectively. Among HIV-infected subjects, lower CD4 count was associated with increased NCAP volume (r=-0.52, p=0.006). CD4 count remained a significant predictor of NCAP in a multivariate analysis that adjusted for age and duration of antiretroviral therapy. Conclusion Plaque burden is similar between HIV-infected and uninfected individuals when matched on traditional CAD risk factors, however immune function may mediate the development of atherosclerosis in HIV infection. PMID:22293714

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

Science.gov (United States)

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

2012-01-01

Amyloid-β 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-β (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 APOEε4 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. PMID:22805771

Atherosclerotic plaque rupture and thrombosis. Evolving concepts.

Science.gov (United States)

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

1990-09-01

Rupture of an atherosclerotic plaque associated with partial or complete thrombotic vessel occlusion is fundamental to the development of ischemic coronary syndromes. Plaques that produce only mild-to-moderate angiographic luminal stenosis are frequently those that undergo abrupt disruption, leading to unstable angina or acute myocardial infarction. Plaques with increased lipid content appear more prone to rupture, particularly when the lipid pool is localized eccentrically within the intima. Macrophages appear to play an important role in atherogenesis, perhaps by participating in the uptake and metabolism of lipoproteins, secretion of growth factors, and production of enzymes and toxic metabolites that may facilitate plaque rupture. In addition, the particular composition or configuration of a plaque and the hemodynamic forces to which it is exposed may determine its susceptibility to disruption. Exposure of collagen, lipids, and smooth muscle cells after plaque rupture leads to the activation of platelets and the coagulation cascade system. The resulting thrombus may lead to marked reduction in myocardial perfusion and the development of an unstable coronary syndrome, or it may become organized and incorporated into the diseased vessel, thus contributing to the progression of atherosclerosis. In unstable angina, plaque disruption leads to thrombosis, which is usually labile and results in only a transient reduction in myocardial perfusion. Release of vasoactive substances, arterial spasm, or increases in myocardial oxygen demand may contribute to ischemia. In acute myocardial infarction, plaque disruption results in a more persistent thrombotic vessel occlusion; the extent of necrosis depends on the size of the artery, the duration of occlusion, the presence of collateral flow, and the integrity of the fibrinolytic system. Thrombi that undergo lysis expose a highly thrombogenic surface to the circulating blood, which has the capacity of activating platelets and

Fluorescence immunoassay for detecting periodontal bacterial pathogens in plaque.

OpenAIRE

Wolff, L F; Anderson, L; Sandberg, G P; Aeppli, D M; Shelburne, C E

1991-01-01

A particle concentration fluorescence immunoassay has been modified into a bacterial concentration fluorescence immunoassay (BCFIA) to rapidly detect periodontopathic bacteria in human plaque samples. The BCFIA utilizes fluorescently tagged monoclonal antibodies (MAbs) directed against the lipopolysaccharide of selected gram-negative plaque bacteria. Microorganisms closely associated with periodontal disease that can be identified in plaque with the BCFIA include Porphyromonas gingivalis, Bac...

Automated, quantitative measures of grey and white matter lesion burden correlates with motor and cognitive function in children with unilateral cerebral palsy.

Science.gov (United States)

Pagnozzi, Alex M; Dowson, Nicholas; Doecke, James; Fiori, Simona; Bradley, Andrew P; Boyd, Roslyn N; Rose, Stephen

2016-01-01

White and grey matter lesions are the most prevalent type of injury observable in the Magnetic Resonance Images (MRIs) of children with cerebral palsy (CP). Previous studies investigating the impact of lesions in children with CP have been qualitative, limited by the lack of automated segmentation approaches in this setting. As a result, the quantitative relationship between lesion burden has yet to be established. In this study, we perform automatic lesion segmentation on a large cohort of data (107 children with unilateral CP and 18 healthy children) with a new, validated method for segmenting both white matter (WM) and grey matter (GM) lesions. The method has better accuracy (94%) than the best current methods (73%), and only requires standard structural MRI sequences. Anatomical lesion burdens most predictive of clinical scores of motor, cognitive, visual and communicative function were identified using the Least Absolute Shrinkage and Selection operator (LASSO). The improved segmentations enabled identification of significant correlations between regional lesion burden and clinical performance, which conform to known structure-function relationships. Model performance was validated in an independent test set, with significant correlations observed for both WM and GM regional lesion burden with motor function (p < 0.008), and between WM and GM lesions alone with cognitive and visual function respectively (p < 0.008). The significant correlation of GM lesions with functional outcome highlights the serious implications GM lesions, in addition to WM lesions, have for prognosis, and the utility of structural MRI alone for quantifying lesion burden and planning therapy interventions.

Automated, quantitative measures of grey and white matter lesion burden correlates with motor and cognitive function in children with unilateral cerebral palsy

Directory of Open Access Journals (Sweden)

Alex M. Pagnozzi

2016-01-01

Full Text Available White and grey matter lesions are the most prevalent type of injury observable in the Magnetic Resonance Images (MRIs of children with cerebral palsy (CP. Previous studies investigating the impact of lesions in children with CP have been qualitative, limited by the lack of automated segmentation approaches in this setting. As a result, the quantitative relationship between lesion burden has yet to be established. In this study, we perform automatic lesion segmentation on a large cohort of data (107 children with unilateral CP and 18 healthy children with a new, validated method for segmenting both white matter (WM and grey matter (GM lesions. The method has better accuracy (94% than the best current methods (73%, and only requires standard structural MRI sequences. Anatomical lesion burdens most predictive of clinical scores of motor, cognitive, visual and communicative function were identified using the Least Absolute Shrinkage and Selection operator (LASSO. The improved segmentations enabled identification of significant correlations between regional lesion burden and clinical performance, which conform to known structure-function relationships. Model performance was validated in an independent test set, with significant correlations observed for both WM and GM regional lesion burden with motor function (p < 0.008, and between WM and GM lesions alone with cognitive and visual function respectively (p < 0.008. The significant correlation of GM lesions with functional outcome highlights the serious implications GM lesions, in addition to WM lesions, have for prognosis, and the utility of structural MRI alone for quantifying lesion burden and planning therapy interventions.

Multi-domain, higher order level set scheme for 3D image segmentation on the GPU

DEFF Research Database (Denmark)

Sharma, Ojaswa; Zhang, Qin; Anton, François

2010-01-01

to evaluate level set surfaces that are $C^2$ continuous, but are slow due to high computational burden. In this paper, we provide a higher order GPU based solver for fast and efficient segmentation of large volumetric images. We also extend the higher order method to multi-domain segmentation. Our streaming...

Emerging Technology Update Intravascular Photoacoustic Imaging of Vulnerable Atherosclerotic Plaque.

Science.gov (United States)

Wu, Min; Fw van der Steen, Antonius; Regar, Evelyn; van Soest, Gijs

2016-10-01

The identification of vulnerable atherosclerotic plaques in the coronary arteries is emerging as an important tool for guiding atherosclerosis diagnosis and interventions. Assessment of plaque vulnerability requires knowledge of both the structure and composition of the plaque. Intravascular photoacoustic (IVPA) imaging is able to show the morphology and composition of atherosclerotic plaque. With imminent improvements in IVPA imaging, it is becoming possible to assess human coronary artery disease in vivo . Although some challenges remain, IVPA imaging is on its way to being a powerful tool for visualising coronary atherosclerotic features that have been specifically associated with plaque vulnerability and clinical syndromes, and thus such imaging might become valuable for clinical risk assessment in the catheterisation laboratory.

MR chemical shift imaging and spectroscopy of atherosclerotic plaque

International Nuclear Information System (INIS)

Vinitski, S.; Consigny, P.M.; Shapiro, M.J.; Janes, N.; Smullens, S.N.; Rifkin, M.D.

1989-01-01

The purpose of this study was to develop a technique for in vivo imaging and characterization of atherosclerotic plaque. The authors used a spin-echo technique with a short echo time (TE) of 11 msec. Lipid/water suppression was achieved by means of hybrid chemical shift imaging. Lesions were induced in three rabbits by a combination of balloon denudation of the abdominal aorta and a high-cholesterol diet. Following in vivo imaging of these rabbit aortas and human carotid arteries (1.5 T), the animals were killed or carotid endarterectomy was performed so that the plaques could be excised. The plaques were then analyzed in vitro both histologically and with high-resolution spectroscopy (8.5 T). Use of the short TE improved lesion visualization. The fat/water suppression showed only a small amount of mobile lipids in plaque. Both MR spectroscopic and histologic analysis corroborated these images. The composition of atherosclerotic plaques in both humans and rabbits was demonstrated to be heterogeneous, with predominantly nonmobile lipids. These results suggest that the combination of short TE MR imaging and fat/water suppression can identify plaque and delineate areas containing mobile lipids

Bacterial sex in dental plaque.

Science.gov (United States)

Olsen, Ingar; Tribble, Gena D; Fiehn, Nils-Erik; Wang, Bing-Yan

2013-01-01

Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

Bacterial sex in dental plaque

Directory of Open Access Journals (Sweden)

Ingar Olsen

2013-06-01

Full Text Available Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

Dynamics of red fluorescent dental plaque during experimental gingivitis--A cohort study.

Science.gov (United States)

van der Veen, Monique H; Volgenant, Catherine M C; Keijser, Bart; Ten Cate, Jacob Bob M; Crielaard, Wim

2016-05-01

The dynamics of red fluorescent plaque (RFP) in comparison to clinical plaque and bleeding scores were studied during an experimental gingivitis protocol in a cohort of healthy participants. Forty-one participants were monitored for RFP before (24h plaque), during 14 days plaque accumulation (days 2, 5, 9, 14) and after 7 days recovery (24h plaque). RFP was assessed on fluorescence photographs of the vestibular aspect of the anterior teeth (cuspid to cuspid) in the upper and lower jaw. Clinical plaque and bleeding were assessed at days -14, 0, 14 and 21. RFP of 24h plaque was reproducible (days -14, 0), then increased during 14 days plaque accumulation and returned to baseline after 7 days recovery. Groups of low, moderate and high RFP formers were statistically significantly different at all times even already at baseline. The individual RFP response during 14 days plaque accumulation correlated well with RFP of 24h plaque (days -14, 0). RFP correlated moderate to well with clinical plaque at days -14, 0, 14 and 21. From day 2 of the gingivitis challenge RFP correlated with bleeding at day 14. RFP provided an objective measure of oral hygiene status. Given the correlation with clinical parameters found, the amount of RFP after 24h plaque accumulation was indicatory for the inflammatory response during a prolonged period of no oral hygiene. This trial was registered at the public trial register ​of the Central Committee on Research Involving Human Subjects (CCMO) under number NL51111.029.14 CLINICAL SIGNIFICANCE: This paper shows the association between RFP after 24h plaque accumulation and inflammatory response after a prolonged period of no oral hygiene. Red plaque fluorescence can be used to identify subjects at risk for developing gingival inflammation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography

International Nuclear Information System (INIS)

Kim, Eun Young; Kang, Doo Kyoung; Sun, Joo Sung; Choi, So Yeon

2013-01-01

Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm 3 , 90.4%) than in calcified plaque (median, 0.7 mm 3 , 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.

Computerized analysis of coronary artery disease: Performance evaluation of segmentation and tracking of coronary arteries in CT angiograms

Energy Technology Data Exchange (ETDEWEB)

Zhou, Chuan, E-mail: chuan@umich.edu; Chan, Heang-Ping; Chughtai, Aamer; Kuriakose, Jean; Agarwal, Prachi; Kazerooni, Ella A.; Hadjiiski, Lubomir M.; Patel, Smita; Wei, Jun [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2014-08-15

Purpose: The authors are developing a computer-aided detection system to assist radiologists in analysis of coronary artery disease in coronary CT angiograms (cCTA). This study evaluated the accuracy of the authors’ coronary artery segmentation and tracking method which are the essential steps to define the search space for the detection of atherosclerotic plaques. Methods: The heart region in cCTA is segmented and the vascular structures are enhanced using the authors’ multiscale coronary artery response (MSCAR) method that performed 3D multiscale filtering and analysis of the eigenvalues of Hessian matrices. Starting from seed points at the origins of the left and right coronary arteries, a 3D rolling balloon region growing (RBG) method that adapts to the local vessel size segmented and tracked each of the coronary arteries and identifies the branches along the tracked vessels. The branches are queued and subsequently tracked until the queue is exhausted. With Institutional Review Board approval, 62 cCTA were collected retrospectively from the authors’ patient files. Three experienced cardiothoracic radiologists manually tracked and marked center points of the coronary arteries as reference standard following the 17-segment model that includes clinically significant coronary arteries. Two radiologists visually examined the computer-segmented vessels and marked the mistakenly tracked veins and noisy structures as false positives (FPs). For the 62 cases, the radiologists marked a total of 10191 center points on 865 visible coronary artery segments. Results: The computer-segmented vessels overlapped with 83.6% (8520/10191) of the center points. Relative to the 865 radiologist-marked segments, the sensitivity reached 91.9% (795/865) if a true positive is defined as a computer-segmented vessel that overlapped with at least 10% of the reference center points marked on the segment. When the overlap threshold is increased to 50% and 100%, the sensitivities were 86

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

DEFF Research Database (Denmark)

Fumagalli, Stefano; Perego, Carlo; Zangari, Rosalia

2017-01-01

Inflammatory mechanisms may be involved in atherosclerotic plaque rupture. By using a novel histology-based method to quantify plaque instability here, we assess whether lectin pathway (LP) of complement activation, a major inflammation arm, could represent an index of plaque instability. Plaques...

Cell surface hydrophobicity of dental plaque microorganisms in situ.

OpenAIRE

Rosenberg, M; Judes, H; Weiss, E

1983-01-01

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 hydr...

Prophylaxis for infective endocarditis: antibiotic sensitivity of dental plaque.

OpenAIRE

MacFarlane, T W; McGowan, D A; Hunter, K; MacKenzie, D

1983-01-01

The antibiotic sensitivity pattern of bacteria isolated from bacteraemia after dental extraction was compared with that of bacteria isolated from dental plaque samples from the same patient. The results supported the current practice of using penicillin and erythromycin empirically for prophylaxis. The prediction of the most appropriate antibiotic for prophylaxis using dental plaque samples was most accurate when the minimum inhibitory concentration (MIC) of plaque isolates were used. It appe...

CT virtual intravascular endoscopy assessment of coronary artery plaques: A preliminary study

International Nuclear Information System (INIS)

Sun Zhonghua; Dimpudus, Franky Jacobus; Nugroho, Johanes; Adipranoto, Jeffrey Daniel

2010-01-01

Purpose: The purpose of this study was to investigate the potential value of CT virtual intravascular endoscopy (VIE) in the visualization and assessment of coronary plaques in patients suspected of coronary artery disease. Materials and methods: 20 (13 men, 7 women, mean age 54 years) consecutive patients with suspected coronary artery disease undergoing 64-slice CT angiography were included in the study. Four main coronary artery branches were assessed with regard to the presence of coronary plaques based on 2D axial, multiplanar reformation, 3D volume rendering and VIE visualizations. The coronary plaques were characterized into calcified, noncalcified and mixed plaques. The intraluminal appearances of these coronary plaques were demonstrated with VIE images and correlated with 2D and 3D images to determine the diagnostic value of VIE for the assessment of the plaques. Results: VIE was able to identify and demonstrate the intraluminal appearances of coronary plaques in 18 patients involving 32 coronary artery branches which were shown as an irregularly intraluminal protruding sign in extensively calcified plaques and smooth protruding appearance in noncalcified or focally calcified plaques. An irregular intraluminal appearance was also noticed in the presence of mixed plaques due to variable components with different CT attenuations contained within the plaques. VIE accurately confirmed the degree of coronary stenosis or occlusion despite the presence of heavy calcification. Conclusion: VIE could be used as a complementary tool to conventional CT visualizations for the analysis of luminal changes and assessment of disease extent caused by the coronary plaques.

Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Young; Kang, Doo Kyoung; Sun, Joo Sung; Choi, So Yeon [Ajou University School of Medicine, Suwon (Korea, Republic of)

2013-12-15

Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm{sup 3}, 90.4%) than in calcified plaque (median, 0.7 mm{sup 3}, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.

Can high frequency ultrasound and MRI diagnose malignant atheromatous plaque in vitro?

International Nuclear Information System (INIS)

Yoshida, Shigeo; Nieminen, M.S.; Paananen, T.; Kahri, A.

1995-01-01

It remains a vital clinical issue how to diagnose malignant atheromatous plaques consisting of ulcerative plaque and hemorrhagic plaque, which are potential risks for thrombosis and the arterial spasm. This study proposes further investigations to develop methods in order to detect this type of lesions by echocardiography. In this study, we tested high frequency (7.5 MHz) US and 1.0 T MRI (Tl weighted SE, STIR; short time inversion recovery sequence, and Tl weighted fat suppression technique) for their precision in the diagnosis of atheromatous plaque as malignant or benign in postmortem human aorta. Ten hemorrhagic plaques were imaged as heterogeneous echo-pattern in the shoulder of plaques covered with high-echo capsule with US; however, these findings were also obtained from 2 of 16 non-hemorrhagic plaques. With TlSE, hemorrhagic plaques were revealed as mixed areas of reduced intensity and high intensity which were differentiated from fatty deposition with Tl weighted fat suppression technique. Ulcerative plaques were revealed as concave shaped plaques and diagnosed correctly with both methods. US was superior to MRI from the viewpoints of examination time and measuring wall thickness. US indicated intimal plus medial thickness of hemorrhagic plaque and non-hemorrhagic plaque at 4.3+1.1 mm and 3.0+1.0 mm (p<0.05) respectively. MRI was vulnerable to artifacts and its image was poorer in quality due to its lower resolution: however, probably because of its superior ability to distinguish fatty deposition from hemorrhage, MRI ultimately enabled more accurate diagnosis than US, as long as its image was fairly clear. The overall accuracies were 80% with US and 85.7% with MRI as confirmed by histological tests. From these results, the careful analysis of the two images obtained from US and MRI enables clinical diagnosis of malignant atheromatous plaques. (author)

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

Science.gov (United States)

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

2012-04-01

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.

Raised soluble P-selectin moderately accelerates atherosclerotic plaque progression.

Directory of Open Access Journals (Sweden)

Kevin J Woollard

Full Text Available Soluble P-selectin (sP-selectin, a biomarker of inflammatory related pathologies including cardiovascular and peripheral vascular diseases, also has pro-atherosclerotic effects including the ability to increase leukocyte recruitment and modulate thrombotic responses in vivo. The current study explores its role in progressing atherosclerotic plaque disease. Apoe-/- mice placed on a high fat diet (HFD were given daily injections of recombinant dimeric murine P-selectin (22.5 µg/kg/day for 8 or 16 weeks. Saline or sE-selectin injections were used as negative controls. In order to assess the role of sP-selectin on atherothrombosis an experimental plaque remodelling murine model, with sm22α-hDTR Apoe-/- mice on a HFD in conjunction with delivery of diphtheria toxin to induce targeted vascular smooth muscle apoptosis, was used. These mice were similarly given daily injections of sP-selectin for 8 or 16 weeks. While plaque mass and aortic lipid content did not change with sP-selectin treatment in Apoe-/- or SM22α-hDTR Apoe-/- mice on HFD, increased plasma MCP-1 and a higher plaque CD45 content in Apoe-/- HFD mice was observed. As well, a significant shift towards a more unstable plaque phenotype in the SM22α-hDTR Apoe-/- HFD mice, with increased macrophage accumulation and lower collagen content, leading to a lower plaque stability index, was observed. These results demonstrate that chronically raised sP-selectin favours progression of an unstable atherosclerotic plaque phenotype.

Echolucency of computerized ultrasound images of carotid atherosclerotic plaques are associated with increased levels of triglyceride-rich lipoproteins as well as increased plaque lipid content

DEFF Research Database (Denmark)

Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Wiebe, Britt M.

1998-01-01

carotid plaque echo-lucency and that echo-lucency predicts a high plaque lipid content. Methods and Results-The study included 137 patients with neurological symptoms and greater than or equal to 50% stenosis of the relevant carotid artery, High-resolution B-mode ultrasound images of carotid plaques were......Background-Echo-lucency of carotid atherosclerotic plaques on computerized ultrasound B-mode images has been associated with a high incidence of brain infarcts as evaluated on CT scans. We tested the hypotheses that triglyceride-rich lipoproteins in the fasting and postprandial state predict...

Plaque Characteristics of Patients with Symptomatic Mild Carotid Artery Stenosis.

Science.gov (United States)

Takai, Hiroki; Uemura, Juniti; Yagita, Yoshiki; Ogawa, Yukari; Kinoshita, Keita; Hirai, Satoshi; Ishihara, Manabu; Hara, Keijirou; Toi, Hiroyuki; Matsubara, Shunji; Nishimura, Hirotake; Uno, Masaaki

2018-03-20

Carotid revascularization may be considered for severe stenosis, but its use for symptomatic mild stenosis (<50%) with vulnerable plaque or ulcer remains uncertain. The characteristics of patients with symptomatic mild stenosis who underwent revascularization are reviewed. The subjects of this study were 18 patients with symptomatic mild stenosis (<50%) on angiography from among 175 patients who underwent revascularization in our department. The plaques were evaluated by black-blood magnetic resonance imaging (BB-MRI) and ultrasonography (US) and classified into 2 types: type 1 (n = 15), a lesion with an ulcer or mobile plaque or thrombosis on angiography or US; and type 2 (n = 3), a lesion without any of the above. Fourteen patients underwent carotid endarterectomy (CEA), and 4 patients underwent carotid artery stenting. The stenosis on angiography was 27.2% ± 10.7 (5%-41%), and the area carotid artery stenosis rate on US was 69.8 ± 14.5% (44.5%-97%). The stenosis rate of these 2 methods was not at all correlated. In type 1 plaque that underwent CEA, 10 of 11 patients had vulnerable plaque by histopathology, and 1 patient had thrombus on the plaque by operative findings. In type 2 plaque that underwent CEA, all patients had vulnerable plaque by histopathology. During the follow-up period, none of the patients had restenosis or stroke. The findings of US and BB-MRI in patients with symptomatic mild stenosis (<50%) on angiography are important for determining treatment. If BB-MRI or US shows the findings of vulnerable plaque in mild stenosis, surgical treatment may be considered for these patients. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

F-18 fluoride positron emission tomography-computed tomography for detecting atherosclerotic plaques

International Nuclear Information System (INIS)

Kang, Won Jun

2015-01-01

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

F-18 fluoride positron emission tomography-computed tomography for detecting atherosclerotic plaques

Energy Technology Data Exchange (ETDEWEB)

Kang, Won Jun [Dept. of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2015-12-15

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

Characteristics of virtual histology-intravascular unltrasound of infarction-related artery atheromatous plaque and pregnancy-associated plasma protein A level: a correlation study

International Nuclear Information System (INIS)

Chen Shaobo; Jiang Tiemin; Liang Guoqing; Zhao Jihong; Li Yuming

2011-01-01

Objective: To observe the characteristics of virtual histology-intravascular ultrasound (VH-IVUS) in 70 patients with acute ST segment elevated type myocardial infarction (AMI), the findings were compared with that in 70 patients with stable angina (control group), and to analyze the correlation between VH-IVUS characteristics and pregnancy-associated plasma protein A (PAPPA) level. Methods: Seventy patients with ST segment elevated AMI and 70 patients with stable angina, who received percutaneous coronary artery intervention and were encountered from Jan. 2008 to Dec. 2009, were involved in this study. After coronary angiography was completed,the plasma was aspirated from culprit coronary artery with ZEEK catheter. Then, IVUS examination to culprit lesion was carried out and grayscale and VH data were stored. The characteristics of VH-IVUS of culprit atheromatous plaque were observed and its correlation with PAPPA was analyzed. Results: The difference in age,gender, hypertension, smoking, diabetes mellitus and hyperlipidemia between two groups was of no statistical significance, but statistically significant difference in VH-IVUS characteristics of the atheromatous plaque existed between two groups, more fibro-fatty tissue and necrotic tissue with less dense calcium were seen in AMI group. The ratio of necrotic tissue area to calcified tissue area was (3.62±1.46) in AMI group and(7.18±2.53) in control group (P<0.01). PAPPA in AMI group was significantly higher than that in control group (P<0.01). Parameters of VH-IVUS in AMI group were highly correlated with PAPPA (P<0.05 or P<0.01). Conclusion: The characteristics of virtual histology-intravascular ultrasound of infarction-related artery atheromatous plaque include more necrotic tissue, higher ratio of necrotic tissue area to calcified tissue area and a closer correlation with PAPPA. (authors)

Comparative study of coronary plaque and stenosis: CT versus MR angiography

International Nuclear Information System (INIS)

Liu Xin; Zhao Xihai; Cheng Liuquan; Zhao Shaohong; Cai Zulong; Cai Youquan; Yang Li

2006-01-01

Objective: To investigate the effect of coronary plaque composition on the extent of stenosis and compare the accuracies of coronary CTA and MRA in detecting significant stenosis (≥50%) caused by different composition plaques. Methods: Thirty patients with coronary heart disease were examined with coronary CTA, MRA and conventional coronary, angiography (CAG) within two weeks. CTA and MRA were performed with a 16-slice CT scanner and hreathhold 3D FIESTA sequence respectively. The coronary plaques were grouped as non-calcified and calcified plaque on CTA images. The accuracies and agreement of CTA and MRA in detecting significant stenosis were evaluated by two experienced radiologists independently using CAG as reference. Results: Fifty-three plaques were detected on CTA. Twenty-eight were non-calcified and the other 25 were calcified. Twenty-one of 28 non-calcified plaques caused significant stenosis on CAG. The sensitivity and specificity of CTA and MRA in detecting significant stenosis were 85.7%, 85.7% and 47.6%, 71.4%, respectively, CTA showed good agreement with CAG (K=0.65). Six of 25 calcified plaques caused significant stenosis on CAG. The sensitivity and specificity of CTA and MRA in detecting significant stenosis were 83.3%, 31.6% and 83.3%, 73.7%, respectively, MRA showed moderate agreement with CAG (K=0.46). Conclusion: CTA was accurate for detecting non-calcified plaque and stenosis, while MRA had advantage to evaluate lumen with severe calcified plaque. (authors)

Metabolomic Effects of Xylitol and Fluoride on Plaque Biofilm in Vivo

Science.gov (United States)

Takahashi, N.; Washio, J.

2011-01-01

Dental caries is initiated by demineralization of the tooth surface through acid production from sugar by plaque biofilm. Fluoride and xylitol have been used worldwide as caries-preventive reagents, based on in vitro-proven inhibitory mechanisms on bacterial acid production. We attempted to confirm the inhibitory mechanisms of fluoride and xylitol in vivo by performing metabolome analysis on the central carbon metabolism in supragingival plaque using the combination of capillary electrophoresis and a time-of-flight mass spectrometer. Fluoride (225 and 900 ppm F−) inhibited lactate production from 10% glucose by 34% and 46%, respectively, along with the increase in 3-phosphoglycerate and the decrease in phosphoenolpyruvate in the EMP pathway in supragingival plaque. These results confirmed that fluoride inhibited bacterial enolase in the EMP pathway and subsequently repressed acid production in vivo. In contrast, 10% xylitol had no effect on acid production and the metabolome profile in supragingival plaque, although xylitol 5-phosphate was produced. These results suggest that xylitol is not an inhibitor of plaque acid production but rather a non-fermentative sugar alcohol. Metabolome analyses of plaque biofilm can be applied for monitoring the efficacy of dietary components and medicines for plaque biofilm, leading to the development of effective plaque control. PMID:21940519

Metabolomic effects of xylitol and fluoride on plaque biofilm in vivo.

Science.gov (United States)

Takahashi, N; Washio, J

2011-12-01

Dental caries is initiated by demineralization of the tooth surface through acid production from sugar by plaque biofilm. Fluoride and xylitol have been used worldwide as caries-preventive reagents, based on in vitro-proven inhibitory mechanisms on bacterial acid production. We attempted to confirm the inhibitory mechanisms of fluoride and xylitol in vivo by performing metabolome analysis on the central carbon metabolism in supragingival plaque using the combination of capillary electrophoresis and a time-of-flight mass spectrometer. Fluoride (225 and 900 ppm F(-)) inhibited lactate production from 10% glucose by 34% and 46%, respectively, along with the increase in 3-phosphoglycerate and the decrease in phosphoenolpyruvate in the EMP pathway in supragingival plaque. These results confirmed that fluoride inhibited bacterial enolase in the EMP pathway and subsequently repressed acid production in vivo. In contrast, 10% xylitol had no effect on acid production and the metabolome profile in supragingival plaque, although xylitol 5-phosphate was produced. These results suggest that xylitol is not an inhibitor of plaque acid production but rather a non-fermentative sugar alcohol. Metabolome analyses of plaque biofilm can be applied for monitoring the efficacy of dietary components and medicines for plaque biofilm, leading to the development of effective plaque control.

Red fluorescence imaging for dental plaque detection and quantification: pilot study

Science.gov (United States)

Liu, Zhao; Gomez, Juliana; Khan, Soniya; Peru, Debbie; Ellwood, Roger

2017-09-01

The red fluorescence of dental plaque originating from porphyrins in oral bacteria may allow visualization, detection, and scoring of plaque without disclosing agents. Two studies were conducted. The first included 24 healthy participants who abstained from oral hygiene for 24 h. Dental plaque was collected from tooth surfaces, and a 10% solution was prepared. These were scanned by a molecular spectrometer to identify the optimum excitation and emission wavelengths of plaque for developing a red fluorescence imaging system. Fourteen healthy subjects completed the second study. After a washout period (1 week), participants had a prophylaxis at baseline and abstained from oral hygiene during the study. They were monitored using the fluorescence imaging system at baseline, 24 h, and 48 h. A dentist clinically assessed plaque after disclosing and on red fluorescence images. Three descriptors were extracted from images and a RUSBoost classifier derived computer fluorescence scores through cross-validation. Red fluorescence plaque levels increased during the 48-h accumulation. Plaque progression was identified by dentist assessment and computer analysis, presenting significant differences between visits at tooth and subject levels (phygiene assessment.

Characterization of plaque in the internal carotid artery. Comparison neuroradiological findings with pathological findings

International Nuclear Information System (INIS)

Nishikawa, Misao; Nishio, Akimasa; Takami, Toshihiro; Goto, Takeo; Ueda, Makiko; Hara, Mitsuhiro

2006-01-01

We evaluate the morphology of the carotid plaque using echogram, CT scan and MRI and compare those neuroradiological findings with histological findings of the plaque. We evaluated 14 cases operated with carotid endoarterectomy for carotid stenosis. We estimated the findings of the echogram, enhanced CT scan and black blood MRI (BB MRI), in comparison with the histological findings of the carotid plaque. Echogram, enhanced CT scan and MRI clearly demonstrated the plaque in cervical carotid stenosis. In most cases, echograms could show the plaque, but in some cases could not due to the back shadow caused by plaque calcification. Enhanced CT scan clearly demonstrated the calcification and the neovasculization in plaque. BB MRI clearly showed the carotid plaque. Low-intensity lesions in T1 and T2 weighted images showed hard and fibrous plaque. High-intensity lesions in T1 and T2 weighted images showed soft plaque with lipoprotein and/or hemorrhage. This study demonstrates the potential of a systemic approach to atherosclerotic plaque with enhanced CT scan and BB MRI compared with histological findings of the carotid plaque. These estimations elucidate the growth mechanism of carotid plaque. (author)

Morphological classification of mobile plaques and their association with early recurrence of stroke.

Science.gov (United States)

Ogata, Toshiyasu; Yasaka, Masahiro; Wakugawa, Yoshiyuki; Kitazono, Takanari; Okada, Yasushi

2010-01-01

The present study investigated the frequency and morphological characteristics of carotid mobile plaques and examined the relationship between carotid mobile plaques and recurrent strokes. The study included 94 consecutive acute stroke patients with large-artery atherosclerosis associated with extracranial carotid stenosis. We investigated the presence of mobile plaques by carotid ultrasonography and classified patients into two groups (mobile group and non-mobile group). We compared backgrounds, MRI and ultrasonographic findings, neurological severity on admission and at discharge, and the rate of early recurrent stroke between both groups. Mobile plaques were detected in 12 patients (12.8%). There were four types of mobile plaques: (1) the jellyfish-type plaque, in which the fibrous cap fluctuated like a jellyfish; (2) the streaming-band-type plaque, in which the string attached to the plaque was swaying; (3) the mobile-thrombus-type plaque, in which a mobile mass was attached to the plaque surface, and (4) the fluctuating-ulcer-type plaque, which contained a mobile substance in the plaque ulcer. Although National Institutes of Health Stroke Scale (NIHSS) scores on admission were less severe in the mobile group than in the non-mobile group (median 1 vs. 4, respectively; p = 0.004), the rate of early recurrent stroke was significantly higher in the mobile group than in the non-mobile group (33.3 vs. 7.3%, respectively; p = 0.022). There were no significant differences in NIHSS scores at discharge between groups. Morphologically, several types of mobile plaques were detected in consecutive patients with acute stroke associated with carotid stenosis. Mobile plaques are strongly associated with an early recurrence of stroke. Copyright © 2010 S. Karger AG, Basel.

Plaque retention on elastomeric ligatures. An in vivo study

OpenAIRE

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

2013-01-01

Fixed orthodontic appliances make it difficult to maintain the oral hygiene, resulting in plaque accumulation. Retention of bacterial plaque, represents a risk for white spot lesions and development of periodontal disease.

Vulnerable plaque detection: The role of 18-fluorine ...

African Journals Online (AJOL)

Positron emission tomography computed tomography (PET-CT) is a combined functional and structural multi modality imaging tool that can be utilized to detect vulnerable and atherosclerotic plaques. In this study we observe the prevalence of active and calcified plaques in selected arteries during whole-body 18F-FDG ...

Bacterial colonization of psoriasis plaques. Is it relevant?

Directory of Open Access Journals (Sweden)

Eva Marcus

2011-08-01

Full Text Available Bacterial colonization was investigated retrospectively in patients with plaque psoriasis (n=98 inpatient treatments, n=73 patients. At least one pathogen was found in 46% of all cases. Staphylococcus aureus was the most frequent bacterium. Bacterial colonization of psoriasis plaques could be relevant in individual cases.

In vivo inhibition of nuclear factor of activated T-cells leads to atherosclerotic plaque regression in IGF-II/LDLR-/-ApoB100/100 mice.

Science.gov (United States)

Blanco, Fabiana; Heinonen, Suvi E; Gurzeler, Erika; Berglund, Lisa M; Dutius Andersson, Anna-Maria; Kotova, Olga; Jönsson-Rylander, Ann-Cathrine; Ylä-Herttuala, Seppo; Gomez, Maria F

2018-03-01

Despite vast clinical experience linking diabetes and atherosclerosis, the molecular mechanisms leading to accelerated vascular damage are still unclear. Here, we investigated the effects of nuclear factor of activated T-cells inhibition on plaque burden in a novel mouse model of type 2 diabetes that better replicates human disease. IGF-II/LDLR -/- ApoB 100/100 mice were generated by crossbreeding low-density lipoprotein receptor-deficient mice that synthesize only apolipoprotein B100 (LDLR -/- ApoB 100/100 ) with transgenic mice overexpressing insulin-like growth factor-II in pancreatic β cells. Mice have mild hyperglycaemia and hyperinsulinaemia and develop complex atherosclerotic lesions. In vivo treatment with the nuclear factor of activated T-cells blocker A-285222 for 4 weeks reduced atherosclerotic plaque area and degree of stenosis in the brachiocephalic artery of IGF-II/LDLR -/- ApoB 100/100 mice, as assessed non-invasively using ultrasound biomicroscopy prior and after treatment, and histologically after termination. Treatment had no impact on plaque composition (i.e. muscle, collagen, macrophages). The reduced plaque area could not be explained by effects of A-285222 on plasma glucose, insulin or lipids. Inhibition of nuclear factor of activated T-cells was associated with increased expression of atheroprotective NOX4 and of the anti-oxidant enzyme catalase in aortic vascular smooth muscle cells. Targeting the nuclear factor of activated T-cells signalling pathway may be an attractive approach for the treatment of diabetic macrovascular complications.

Dosimetric study of the 15 mm ROPES eye plaque

International Nuclear Information System (INIS)

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

2004-01-01

The main aim of this paper is to make a study of dose-rate distributions obtained around the 15 mm, radiation oncology physics and engineering services, Australia (ROPES) eye plaque loaded with 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

Nonlinear registration of serial coronary CT angiography (CCTA) for assessment of changes in atherosclerotic plaque

International Nuclear Information System (INIS)

Woo, Jonghye; Dey, Damini; Cheng, Victor Y.; Hong, Byung-Woo; Ramesh, Amit; Sundaramoorthi, Ganesh; Nakazato, Ryo; Berman, Daniel S.; Germano, Guido; Kuo, C.-C. Jay; Slomka, Piotr J.

2010-01-01

Purpose: Coronary CT angiography (CCTA) is a high-resolution three-dimensional imaging technique for the evaluation of coronary arteries in suspected or confirmed coronary artery disease (CAD). Coregistration of serial CCTA scans would allow precise superimposition of images obtained at two different points in time, which could aid in recognition of subtle changes and precise monitoring of coronary plaque progression or regression. To this end, the authors aimed at developing a fully automatic nonlinear volume coregistration for longitudinal CCTA scan pairs. Methods: The algorithm combines global displacement and local deformation using nonlinear volume coregistration with a volume-preserving constraint. Histogram matching of intensities between two serial scans is performed prior to nonlinear coregistration with dense nonparametric local deformation in which sum of squared differences is used as a similarity measure. The approximate segmentation of coronary arteries obtained from commercially available software provides initial anatomical landmarks for the coregistration algorithm that help localize and emphasize the structure of interest. To avoid possible bias caused by incorrect segmentation, the authors convolve the Gaussian kernel with the segmented binary coronary tree mask and define an extended weighted region of interest. A multiresolution approach is employed to represent coarse-to-fine details of both volumes and the energy function is optimized using a gradient descent method. The authors applied the algorithm in ten paired CCTA datasets (20 scans in total) obtained within 10.7±5.7 months from each other on a dual source CT scanner to monitor progression of CAD. Results: Serial CCTA coregistration was successful in 9/10 cases as visually confirmed. The global displacement and local deformation of target registration error obtained from four anatomical landmarks were 2.22±1.15 and 1.56±0.74 mm, respectively, and the inverse consistency error of local

Effect of coconut oil in plaque related gingivitis - A preliminary report.

Science.gov (United States)

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

2015-01-01

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

Orbital Atherectomy Plaque Modification Assessment of the Femoropopliteal Artery Via Intravascular Ultrasound (TRUTH Study).

Science.gov (United States)

Babaev, Anvar; Zavlunova, Susanna; Attubato, Michael J; Martinsen, Brad J; Mintz, Gary S; Maehara, Akiko

2015-10-01

The Tissue Removal Assessment with Ultrasound of the SFA and Popliteal (TRUTH) study assessed the performance of the orbital atherectomy system (OAS) to treat femoropopliteal arteries, including determining its effect on plaque removal. Patients with symptomatic femoropopliteal peripheral arterial disease were treated with the OAS followed by adjunctive balloon angioplasty (BA). Intravascular ultrasound (IVUS) images were collected pre- and post-OAS and post-OAS BA. Patients were followed through 12 months post-procedure. Twenty-nine lesions were treated with OAS-BA in 25 patients. The mean maximum balloon inflation pressure was 5.2 ± 1.2 atm. Virtual histology IVUS (VH-IVUS) analysis revealed at the maximum calcium ablation site that calcium reduction was responsible for 86% of the lumen area increase. The minimum lumen area increased from 4.0 mm(2) to 9.1 mm(2) (<.0001), and the percentage of area stenosis decreased from 76.9% to 43.0% (<.0001) after OAS-BA. At 12 months, the target lesion revascularization rate was 8.2%, and ankle-brachial index and Rutherford classification improved significantly from baseline through follow-up. The VH-IVUS analysis reveals that OAS modifies the calcified component of the plaque burden. It is hypothesized that calcium modification by OAS changes the lesion compliance, allowing for low pressure adjunctive BA. The clinical outcomes were favorable through 12-month follow-up. © The Author(s) 2015.

Cryotherapy-induced milia en plaque: case report and literature review.

Science.gov (United States)

Beutler, Bryce David; Cohen, Philip R

2014-12-12

Cryotherapy-induced milia is a rarely described cutaneous reaction that may occur in patients who have received cryotherapy with liquid nitrogen. Cryotherapy-induced milia is characterized by 1-2 millimeter white dermal cysts that develop at the healed cryotherapy site. Milia en plaque, an erythematous plaque containing numerous milia, has not previously been described following treatment of a skin lesion with liquid nitrogen cryotherapy. We describe a man who developed cryotherapy-induced milia en plaque after receiving cryotherapy to his dorsal hand for the treatment of an actinic keratosis. We also summarize the potential complications of cryotherapy, the differential diagnosis of milia en plaque, and therapeutic interventions for this lesion. The features of a man with cryotherapy-induced milia en plaque are presented. Using PubMed, the following terms were searched and relevant citations assessed: cryosurgery, cryotherapy, hypothermia, milia, milia en plaque, and Wolf's isotopic response. In addition, the literature on cryotherapy-induced milia and cryotherapy-induced milia en plaque is reviewed. Our patient developed cryotherapy-induced milia en plaque shortly after his cryotherapy site had healed. Some of the asymptomatic cystic dermal lesions had spontaneously resolved when a lesional biopsy was performed to confirm the diagnosis. The diagnosis, natural course, and potential treatments were discussed with the patient. Subsequent management was to observe the area; at follow-up examination, the remainder of the milia had also spontaneously resolved. Cryotherapy-induced milia is a benign condition characterized by the development of small white dermal cystic lesions that develop at a healed liquid nitrogen cryotherapy site. The lesions may appear individually or as milia en plaque. While the mechanism of pathogenesis is unknown, we postulate that the condition is an example of Wolf's isotopic response, in which a new, unrelated skin disease develops at the

Echo-lucency of computerized ultrasound images of carotid atherosclerotic plaques are associated with increased levels of triglyceride-rich lipoproteins as well as increased plaque lipid content

DEFF Research Database (Denmark)

Grønholdt, Marie-Louise Moes; Nordestgaard, Børge G.; Weibe, Brit M.

1998-01-01

carotid plaque echo-lucency and that echo-lucency predicts a high plaque lipid content. Methods and Results-The study included 137 patients with neurological symptoms and greater than or equal to 50% stenosis of the relevant carotid artery, High-resolution B-mode ultrasound images of carotid plaques were......Background-Echo-lucency of carotid atherosclerotic plaques on computerized ultrasound B-mode images has been associated with a high incidence of brain infarcts as evaluated on CT scans. We tested the hypotheses that triglyceride-rich lipoproteins in the fasting and postprandial state predict...

Serum zinc, senile plaques, and neurofibrillary tangles: findings from the Nun Study.

Science.gov (United States)

Tully, C L; Snowdon, D A; Markesbery, W R

1995-11-13

Zinc appears to have a role in binding amyloid precursor protein in vitro, but it is not known whether zinc plays a role in senile plaque formation in vivo in humans. Serum zinc concentrations were available from 12 sisters who died in the Nun Study, a longitudinal study of aging and Alzheimer's disease. Fasting serum zinc concentrations, determined approximately 1 year before death, showed moderate to strong negative correlations with senile plaque counts in seven brain regions. In all brain regions combined, the age-adjusted negative correlations with serum zinc were statistically significant for total senile plaques and diffuse plaques, and suggestive for neuritic plaques. Thus serum zinc in the normal range may be associated with low senile plaque counts in the elderly.

Anti-plaque effect of a synergistic combination of green tea and Salvadora persica L. against primary colonizers of dental plaque.

Science.gov (United States)

Abdulbaqi, Hayder Raad; Himratul-Aznita, Wan Harun; Baharuddin, Nor Adinar

2016-10-01

Green tea (Gt), leafs of Camellia sinensis var. assamica, is widely consumed as healthy beverage since thousands of years in Asian countries. Chewing sticks (miswak) of Salvadora persica L. (Sp) are traditionally used as natural brush to ensure oral health in developing countries. Both Gt and Sp extracts were reported to have anti-bacterial activity against many dental plaque bacteria. However, their combination has never been tested to have anti-bacterial and anti-adherence effect against primary dental plaque colonizers, playing an initial role in the dental plaque development, which was investigated in this study. Two-fold serial micro-dilution method was used to measure minimal inhibitory concentration (MIC) of aqueous extracts of Gt, Sp and their combinations. Adsorption to hexadecane was used to determine the cell surface hydrophobicity (CSH) of bacterial cells. Glass beads were used to mimic the hard tissue surfaces, and were coated with saliva to develop experimental pellicles for the adhesion of the primary colonizing bacteria. Gt aqueous extracts exhibited better anti-plaque effect than Sp aqueous extracts. Their combination, equivalent to 1/4 and 1/2 of MIC values of Gt and Sp extracts respectively, showed synergistic anti-plaque properties with fractional inhibitory concentration (FIC) equal to 0.75. This combination was found to significantly reduce CSH (pplaque activity, and could be used as a useful active agent to produce oral health care products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Early supra- and subgingival plaque formation in experimental gingivitis in smokers and never-smokers.

Science.gov (United States)

Branco, Paula; Weidlich, Patricia; Oppermann, Rui Vicente; Rösing, Cassiano Kuchenbecker

2015-01-01

To evaluate supragingival and subgingival plaque formation on the dentogingival area in smokers and never smokers using the experimental gingivitis model and a plaque scoring system that considers the presence of an area free of plaque between plaque and the gingival sulcus called the plaque free zone (PFZ). Male volunteers, 9 current smokers and 10 never-smokers, refrained from oral hygiene procedures in the maxillary incisors and canines (test teeth) for 25 days. Under conditions of clinically healthy gingiva (phase 1) and gingival inflammation (phase 2), the supragingival plaque formation pattern was observed for 4 days in the dentogingival area. Gingival crevicular fluid was also measured. Plaque was dyed with fucsine and its presence was recorded by a calibrated examiner based on a 3-criteria scoring system: 0 - absence of stained plaque; 1 - presence of stained plaque and supragingival PFZ; 2 - presence of stained plaque and absence of PFZ, indicating that subgingival plaque formation has taken place. In both phases, smokers presented a significantly lower relative frequency of sites with subgingival plaque compared to never-smokers (P smokers demonstrated a significantly lower frequency of gingival bleeding than did non-smokers (23.6% vs 66.1%; P Smokers presented significantly lower percentages of sites with subgingival plaque in all experimental periods and presented less gingival inflammation as shown by GBI and gingival crevicular fluid quantification.

Induction Therapy With Antithymocyte Globulin in Patients Undergoing Cardiac Transplantation Is Associated With Decreased Coronary Plaque Progression as Assessed by Intravascular Ultrasound.

Science.gov (United States)

Azarbal, Babak; Cheng, Richard; Vanichsarn, Christopher; Patel, Jignesh K; Czer, Lawrence S; Chang, David H; Kittleson, Michelle M; Kobashigawa, Jon A

2016-01-01

Antithymocyte globulin (ATG) is used as induction therapy after cardiac transplant for enhancing immunosuppression and delaying the initiation of nephrotoxic drugs. It is unknown if ATG induction is associated with decreased coronary plaque progression by intravascular ultrasound (IVUS). Patients transplanted between March 2010 and December 2012 with baseline and 1-year IVUS were included. All patients transplanted were included in a secondary analysis. Change in plaque progression was measured in a blinded fashion on matched coronary segments and contrasted between patients induced with ATG and those who were not. One hundred and three patients were included in IVUS arms. Mean age at transplant was 55.8 ± 12.6 years, and 33.0% were female. Patients induced with ATG were more sensitized (54.3% versus 14.3%). Plaque progression was attenuated in patients who received ATG by changes in maximal intimal area (1.0 ± 1.2 versus 2.3 ± 2.6 mm(2); P = 0.001), maximal percent stenosis (6.3 ± 7.9 versus 12.8 ± 12.3%; = 0.003), maximal intimal thickness (0.2 ± 0.2 versus 0.3 ± 0.3 mm; P = 0.035), and plaque volume (0.5 ± 0.7 versus 1.0 ± 1.3 mm(3)/mm; P = 0.016). Rapid plaque progression by maximal percent stenosis (≥ 20%) occurred less frequently in the ATG arm (4.3% versus 26.3; P = 0.003). Survival (P = 0.242) and any treated rejection (P = 0.166) were not statistically different between groups. Patients receiving ATG had a higher rate of first-year infection (P = 0.003), perhaps related to increased intravenous antibiotic use immediately postoperatively, and a trend toward more biopsy-proven rejection (P = 0.073). Induction therapy with ATG is associated with reduced first-year coronary plaque progression as assessed by IVUS, despite an increased prevalence of sensitized patients with a trend toward more rejection. © 2016 American Heart Association, Inc.

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

Science.gov (United States)

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

2014-06-01

The vulnerable atherosclerotic plaque is believed to be at the root of the majority of acute coronary events. Even though the exact origins of plaque vulnerability remain elusive, the thin-cap fibroatheroma, characterized by a lipid-rich necrotic core covered by a thin fibrous cap, is considered to be the most prominent type of vulnerable plaque. No clinically available imaging technique can characterize atherosclerotic lesions to the extent needed to determine plaque vulnerability prognostically. Intravascular photoacoustic imaging (IVPA) has the potential to take a significant step in that direction by imaging both plaque structure and composition. IVPA is a natural extension of intravascular ultrasound that adds tissue type specificity to the images. IVPA utilizes the optical contrast provided by the differences in the absorption spectra of plaque components to image composition. Its capability to image lipids in human coronary atherosclerosis has been shown extensively ex vivo and has recently been translated to an in vivo animal model. Other disease markers that have been successfully targeted are calcium and inflammatory markers, such as macrophages and matrix metalloproteinase; the latter two through application of exogenous contrast agents. By simultaneously displaying plaque morphology and composition, IVPA can provide a powerful prognostic marker for disease progression, and as such has the potential to transform the current practice in percutaneous coronary intervention. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Classification of Carotid Plaque Echogenicity by Combining Texture Features and Morphologic Characteristics.

Science.gov (United States)

Huang, Xiaowei; Zhang, Yanling; Qian, Ming; Meng, Long; Xiao, Yang; Niu, Lili; Zheng, Rongqin; Zheng, Hairong

2016-10-01

Anechoic carotid plaques on sonography have been used to predict future cardiovascular or cerebrovascular events. The purpose of this study was to investigate whether carotid plaque echogenicity could be assessed objectively by combining texture features extracted by MaZda software (Institute of Electronics, Technical University of Lodz, Lodz, Poland) and morphologic characteristics, which may provide a promising method for early prediction of acute cardiovascular disease. A total of 268 plaque images were collected from 136 volunteers and classified into 85 hyperechoic, 83 intermediate, and 100 anechoic plaques. About 300 texture features were extracted from histogram, absolute gradient, run-length matrix, gray-level co-occurrence matrix, autoregressive model, and wavelet transform algorithms by MaZda. The morphologic characteristics, including degree of stenosis, maximum plaque intima-media thickness, and maximum plaque length, were measured by B-mode sonography. Statistically significant features were selected by analysis of covariance. The most discriminative features were obtained from statistically significant features by linear discriminant analysis. The K-nearest neighbor classifier was used to classify plaque echogenicity based on statistically significant and most discriminative features. A total of 30 statistically significant features were selected among the plaques, and 2 most discriminative features were obtained from the statistically significant features. The classification accuracy rates for 3 types of plaques based on statistically significant and most discriminative features were 72.03% (κ= 0.571; P MaZda and morphologic characteristics.

Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging

Science.gov (United States)

Doherty, Joshua Ryan

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

Non-calcified coronary plaque volume inversely related to CD4(+) T-cell count in HIV infection.

Science.gov (United States)

Duarte, Horacio; Matta, Jatin R; Muldoon, Nancy; Masur, Henry; Hadigan, Colleen; Gharib, Ahmed M

2012-01-01

Non-calcified coronary artery plaque (NCAP) might be an important predictor of cardiovascular events; however, few studies have directly measured NCAP in HIV-infected individuals. We completed a prospective cross-sectional evaluation of NCAP and coronary calcium scores using computed tomography angiography in HIV-infected patients (n=26) without known coronary artery disease (CAD), but who had one or more CAD risk factor(s), and compared them with controls matched on age, race, sex, body mass index and Framingham Risk Score (n=26). There was no difference in coronary calcium scores (114 ± 218 versus 124 ± 298; P=0.89) or NCAP volume (65 ± 86 mm(3) versus 63 ± 82 mm(3); P=0.38) between HIV-infected patients and controls, respectively. Among HIV-infected patients, lower CD4(+) T-cell count was associated with increased NCAP volume (r=-0.52, P=0.006). The CD4(+) T-cell count remained a significant predictor of NCAP in a multivariate analysis that adjusted for age and duration of antiretroviral therapy. Plaque burden is similar between HIV-infected and uninfected individuals when matched on traditional CAD risk factors; however, immune function might mediate the development of atherosclerosis in HIV infection.

Effect of baking soda in dentifrices on plaque removal.

Science.gov (United States)

Myneni, Srinivas R

2017-11-01

The prevention of dental caries and periodontal diseases targets control of dental plaque biofilm. In this context, chemical agents could represent a valuable complement to mechanical plaque control by reducing and controlling biofilm formation. The literature on the effectiveness of different dentifrices has not, however, been carefully categorized. A lack of consensus exists among dental professionals on a recommendation for a universal dentifrice for plaque control. The authors reviewed the scientific data on the different properties of sodium bicarbonate (baking soda)-containing dentifrices and their effectiveness in plaque removal. The results of the literature search show that baking soda-containing dentifrices are ideal candidates to be considered as a universal dentifrice because baking soda is inexpensive, abundant in supply, highly biocompatible, exhibits specific antibacterial properties to oral microorganisms, has low abrasivity, and is effective in plaque biofilm removal. Although some patients may benefit from desensitizing or high fluoride-containing dentifrices, those with routine needs may find using dentifrices containing baking soda and fluoride effective. Baking soda and fluoride dentifrices, therefore, may perhaps be considered as a criterion standard for patients with routine oral hygiene needs. Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.

Evaluation of the early enhancement of coronary atherosclerotic plaque by contrast-enhanced MR angiography

Energy Technology Data Exchange (ETDEWEB)

Li Tao [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhao Xihai [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Liu Xin [Paul C. Lauterbur Biomedical Imaging Center, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Science, Shenzhen 518067 (China); Gao Jianhua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Zhao Shaohong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Li Xin; Zhou Weihua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Cai Zulong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhang Weiguo [Cardiovascular and Neurological Consulting Institute, 6771 San Fernando, Irving, TX 75039 (United States); Yang Li, E-mail: Yangli301@yahoo.com [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China)

2011-10-15

Purpose: To evaluate the early enhancement of coronary atherosclerotic plaque using contrast-enhanced MR angiography (CE-MRA) and investigate the association between unstable angina pectoris (UAP) and early enhancement of the plaque. Methods: Forty-one patients presenting with angina pectoris and demonstrating single-vessel disease with non-calcified plaque and significant coronary stenosis ({>=}50%) on CTA were consecutively recruited for coronary CE-MRA. Contrast-to-noise ratio of the culprit plaque guided by CTA was measured on a cross-sectional multi-planar reconstruction image of the plaque on both pre- and post-CE-MRA. A 50% increasing of CNR was defined as plaque enhancement. The association between early enhancement of the plaques and UAP was analyzed. Results: Thirty-seven non-calcified plaques with significant coronary stenosis were detected in the 37 patients on MRA. 4 subjects were excluded because coronary atherosclerotic plaques were inadequate for identification on MRA. Of the 37 patients, 18 patients had UAP and other 19 patients presented stable angina pectoris (SAP). Of the 37 plaques on CE-MRA, 13 and 24 plaques presented early enhancement and no enhancement, respectively. Of the 13 early-enhanced plaques, 11 (85%) and 2 (15%) were found in the patients with UAP and SAP, respectively (p < 0.01). Of the 37 patients, 11 (61%) with UAP and 2 (11%) with SAP had early-enhanced plaques, respectively (p < 0.01). Conclusion: CE-MRA allows detection of early enhancement of coronary atherosclerotic plaque. The early enhancement is common in unstable angina and could be a sign of vulnerability.

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Monte Carlo Estimation of Absorbed Dose Distributions Obtained from Heterogeneous 106Ru Eye Plaques.

Science.gov (United States)

Zaragoza, Francisco J; Eichmann, Marion; Flühs, Dirk; Sauerwein, Wolfgang; Brualla, Lorenzo

2017-09-01

The distribution of the emitter substance in 106 Ru eye plaques is usually assumed to be homogeneous for treatment planning purposes. However, this distribution is never homogeneous, and it widely differs from plaque to plaque due to manufacturing factors. By Monte Carlo simulation of radiation transport, we study the absorbed dose distribution obtained from the specific CCA1364 and CCB1256 106 Ru plaques, whose actual emitter distributions were measured. The idealized, homogeneous CCA and CCB plaques are also simulated. The largest discrepancy in depth dose distribution observed between the heterogeneous and the homogeneous plaques was 7.9 and 23.7% for the CCA and CCB plaques, respectively. In terms of isodose lines, the line referring to 100% of the reference dose penetrates 0.2 and 1.8 mm deeper in the case of heterogeneous CCA and CCB plaques, respectively, with respect to the homogeneous counterpart. The observed differences in absorbed dose distributions obtained from heterogeneous and homogeneous plaques are clinically irrelevant if the plaques are used with a lateral safety margin of at least 2 mm. However, these differences may be relevant if the plaques are used in eccentric positioning.

Chronic plaque psoriasis | Luba | South African Family Practice

African Journals Online (AJOL)

Chronic plaque psoriasis, the most common form of psoriasis, is a papulosquamous disease defined by erythematous plaques with a silvery scale. The diagnosis usually is clinical, but occasionally a biopsy is necessary. Psoriasis affects 0.6 to 4.8 percent of the U.S. population, and about 30 percent of affected patients have ...

Macrophage antioxidant protection within atherosclerotic plaques.

Science.gov (United States)

Gieseg, Steven P; Leake, David S; Flavall, Elizabeth M; Amit, Zunika; Reid, Linzi; Yang, Ya-Ting

2009-01-01

Macrophage cells within inflammatory lesions are exposed to a wide range of degrading and cytotoxic molecules including reactive oxygen species. Unlike neutrophils, macrophages do not normally die in this environment but continue to generate oxidants, phagocytose cellular remains, and release a range of cyto-active agents which modulate the immune response. It is this potential of the macrophage cell to survive in an oxidative environment that allows the growth and complexity of advanced atherosclerotic plaques. This review will examine the oxidants encountered by macrophages within an atherosclerotic plaque and describe some of the potential antioxidant mechanisms which enable macrophages to function within inflammatory lesions. Ascorbate, a-tocopherol, and glutathione appear to be central to the protection of macrophages yet additional antioxidant mechanisms appear to be involved. Gamma-Interferon causes macrophages to generate 7,8-dihydroneopterin, neopterin and 3-hydroxyanthranilic acid both of which have antioxidant properties. Manganese superoxide dismutase is also upregulated in macrophages. The evidence that these antioxidants provide further protection, so allowing the macrophage cells to survive within sites of chronic inflammation such as atherosclerotic plaques, will be described.

Factors Influencing Virulence and Plaque Properties of Attenuated Venezuelan Equine Encephalomyelitis Virus Populations

Science.gov (United States)

Hearn, Henry J.; Seliokas, Zenonas V.; Andersen, Arthur A.

1969-01-01

A minority of stable large-plaque virus increased proportionally in stored unstable attenuated (9t) Venezuelan equine encephalomyelitis virus populations. L-cell-grown progeny (9t2) of stored 9t showed large amounts of large-plaque virus and increased virulence. Small-plaque virus inhibited large-plaque virus but not the reverse. Serial passage of small-plaque virus from 9t2 yielded a strain (20t) that was more attenuated than 9t. PMID:5823235

The relationship between coronary stenosis severity and compression type coronary artery movement in acute myocardial infarction.

Science.gov (United States)

Chan, Kim H; Chawantanpipat, Chirapan; Gattorna, Tim; Chantadansuwan, Thamarath; Kirby, Adrienne; Madden, Ann; Keech, Anthony; Ng, Martin K C

2010-04-01

Acute myocardial infarction is thought to occur at sites of minor coronary stenosis. Recent data challenge this and also propose a role for coronary artery movement (CAM) in plaque instability. We examined the relationship between coronary stenosis severity, CAM pattern, and infarct-related lesions (IRLs) in acute myocardial infarction. We investigated 203 consecutive patients with ST-segment elevation myocardial infarction after successful fibrinolysis. Quantitative coronary angiography, CAM pattern, and extent score (atheroma burden) analysis was performed for each coronary artery segment. The IRL stenosis was at least moderate (>50%) and severe (>70%) in 78% and 31% of patients, respectively. Culprit arteries were associated with higher atheroma extent scores (25.2 vs 21.6, P 70% vs Compression CAM was also strongly associated with culprit segments (OR 3.4, 95% CI 2.6-4.5, P compression CAM and stenosis severity were strongly correlated, with the likelihood of a coronary segment having compression CAM progressively increasing with worsening stenosis (OR 56.4, 95% CI 37.9-83.8, P 70% vs relationship between stenosis severity and IRLs. Our study also raises the hypothesis that compression CAM may accelerate atherosclerosis and predispose to plaque vulnerability. Copyright 2010 Mosby, Inc. All rights reserved.

Kinetics of monofluorophosphate hydrolysis in a bacterial test plaque in situ.

Science.gov (United States)

Tenuta, L M A; Del Bel Cury, A A; Tabchoury, C P M; Moi, G P; Silva, W J; Cury, J A

2010-01-01

Models to evaluate the anticaries potential of fluoride (F) formulations containing monofluorophosphate (MFP) should consider the release of F ion to the oral environment by its enzymatic hydrolysis. This was tested in situ, using a test plaque of a strain of Streptococcus mutans which presents high MFPase activity at pH 5.0. The test plaque was exposed to non-F or MFP (1,450 microg F/g) dentifrices and the fluid phase of the plaque was analyzed after 15, 30, 45 and 75 min. MFP concentration in the plaque fluid decreased over time after exposure to MFP dentifrice, but F ion reached 134.9 +/- 32.0 microM at 15 min and decreased significantly only at 75 min, suggesting continuous MFP hydrolysis by the test plaque. Copyright 2010 S. Karger AG, Basel.

Acid production in dental plaque after exposure to probiotic bacteria

Directory of Open Access Journals (Sweden)

Keller Mette K

2012-10-01

Full Text Available Abstract Background The increasing interest in probiotic lactobacilli in health maintenance has raised the question of potential risks. One possible side effect could be an increased acidogenicity in dental plaque. The aim of this study was to investigate the effect of probiotic lactobacilli on plaque lactic acid (LA production in vitro and in vivo. Methods In the first part (A, suspensions of two lactobacilli strains (L. reuteri DSM 17938, L. plantarum 299v were added to suspensions of supragingival dental plaque collected from healthy young adults (n=25. LA production after fermentation with either xylitol or fructose was analyzed. In the second part (B, subjects (n=18 were given lozenges with probiotic lactobacilli (L. reuteri DSM 17938 and ATCC PTA 5289 or placebo for two weeks in a double-blinded, randomized cross-over trial. The concentration of LA in supragingival plaque samples was determined at baseline and after 2 weeks. Salivary counts of mutans streptococci (MS and lactobacilli were estimated with chair-side methods. Results Plaque suspensions with L. reuteri DSM 17938 produced significantly less LA compared with L. plantarum 299v or controls (p Conclusion Lactic acid production in suspensions of plaque and probiotic lactobacilli was strain-dependant and the present study provides no evidence of an increase in plaque acidity by the supply of selected probiotic lactobacilli when challenged by fructose or xylitol. The study protocol was approved by The Danish National Committee on Biomedical Research Ethics (protocol no H-2-2010-112. Trial registration NCT01700712

Red fluorescence of dental plaque in children -A cross-sectional study.

Science.gov (United States)

Volgenant, Catherine M C; Zaura, Egija; Brandt, Bernd W; Buijs, Mark J; Tellez, Marisol; Malik, Gayatri; Ismail, Amid I; Ten Cate, Jacob M; van der Veen, Monique H

2017-03-01

The relation between the presence of red fluorescent plaque and the caries status in children was studied. In addition, the microbial composition of dental plaque from sites with red fluorescent plaque (RFP) and from sites with no red fluorescent plaque (NFP) was assessed. Fluorescence photographs were taken from fifty children (6-14 years old) with overnight plaque. Full-mouth caries scores (ICDAS II) were obtained. The composition of a saliva sample and two plaque samples (RFP and NFP) was assessed using 16S rDNA sequencing. At the site level, no clinically relevant correlations were found between the presence of RFP and the caries status. At the subject level, a weak correlation was found between RFP and the caries status when non-cavitated lesions were included (r s =0.37, p=0.007). The microbial composition of RFP differed significantly from NFP. RFP had more anaerobes and more Gram-negative bacterial taxa. The most discriminative operational taxonomic units (OTUs) for RFP were Corynebacterium, Leptotrichia, Porphyromonas and Selenomonas, while the most discriminative OTUs for NFP were Neisseria, Actinomyces, Streptococcus and Rothia. There were no clinical relevant correlations in this cross-sectional study between the presence of RFP and (early) caries lesions. There were differences in the composition of these phenotypically different plaque samples: RFP contained more Gram-negative, anaerobic taxa and was more diverse than NFP. The study outcomes provide more insight in the possibilities to use plaque fluorescence in oral health risk assessments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Three-dimensional dosimetry imaging of I-125 plaque for eye cancer treatment

Energy Technology Data Exchange (ETDEWEB)

Weaver, M.; Green, J.; Petasecca, M.; Lerch, M.L.F.; Cutajar, D.; Franklin, D. [Centre for Medical Radiation Physics-University of Wollongong, Northfileds Avenue, Wollongong 2500 NSW (Australia); Jakubek, J. [Institute of Experimental and Applied Physics, Czech Technical University in Prague, 12800 Prague 2 (Czech Republic); Carolan, M.G. [Centre for Medical Radiation Physics-University of Wollongong, Northfileds Avenue, Wollongong 2500 NSW (Australia); Illawarra Cancer Care Centre, Wollongong 2500 NSW (Australia); Conway, M. [Sydney Eye Hospital-Faculty of Medicine, The University of Sydney, Sydney 2006 NSW (Australia); Pospisil, S. [Institute of Experimental and Applied Physics, Czech Technical University in Prague, 12800 Prague 2 (Czech Republic); Kron, T. [Peter MacCallum Cancer Centre, Melbourne Vic 8006 (Australia); Metcalfe, P. [Centre for Medical Radiation Physics-University of Wollongong, Northfileds Avenue, Wollongong 2500 NSW (Australia); Zaider, M. [Memorial Sloan-Kettering Cancer Centre, New York, NY 10021 (United States); Rosenfeld, A.B., E-mail: anatoly@uow.edu.au [Centre for Medical Radiation Physics-University of Wollongong, Northfileds Avenue, Wollongong 2500 NSW (Australia)

2011-05-15

Treatment of ocular cancers using eye plaque brachytherapy is now an established medical procedure. However, current QA for these eye plaques is quite rudimentary, limiting the opportunities for precise pre-tumour plaque customisation. This paper proposes and experimentally validates a new technique for imaging of eye plaque dose distributions using a high-resolution pixelated silicon detector. Results are presented demonstrating the 2D and 3D isodose surfaces produced using experimental data collected using this method.

Three-dimensional dosimetry imaging of I-125 plaque for eye cancer treatment

International Nuclear Information System (INIS)

Weaver, M.; Green, J.; Petasecca, M.; Lerch, M.L.F.; Cutajar, D.; Franklin, D.; Jakubek, J.; Carolan, M.G.; Conway, M.; Pospisil, S.; Kron, T.; Metcalfe, P.; Zaider, M.; Rosenfeld, A.B.

2011-01-01

Treatment of ocular cancers using eye plaque brachytherapy is now an established medical procedure. However, current QA for these eye plaques is quite rudimentary, limiting the opportunities for precise pre-tumour plaque customisation. This paper proposes and experimentally validates a new technique for imaging of eye plaque dose distributions using a high-resolution pixelated silicon detector. Results are presented demonstrating the 2D and 3D isodose surfaces produced using experimental data collected using this method.

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

Science.gov (United States)

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

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Taggart, M.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom); Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain)], E-mail: mark.taggart@uclm.es; Mateo, R. [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain); Charnock, J.M.; Bahrami, F. [Synchrotron Radiation Department, CCLRC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Green, A.J. [Department of Wetland Ecology, Estacion Biologica de Donana, CSIC, Pabellon del Peru, Avenida Maria Luisa s/n, 41013 Seville (Spain); Meharg, A.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom)

2009-03-15

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

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

Science.gov (United States)

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

2010-01-01

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. (c) 2010 S. Karger AG, Basel.

The formation of atherosclerotic plaque, its destabilisation and diagnostics

Directory of Open Access Journals (Sweden)

Piotr Kaźmierski

2014-04-01

Full Text Available According to the established medical knowledge, the atheromatous lesions occur in the arteries of large and medium diameter. Their presence in the aorta, arteries of extremities as well as extracerebral and coronal arteries is clinically relevant. The evolution of atherosclerotic plaques probably starts in the prenatal development, what may be proved by the presence of the fatty streaks in endothelium of coronal arteries in some newborns. Then it evolves through lipid accumulation, media inflammatory response, vasa vasorum proliferation, fibrination and calcification of plaques. Researches proved that the matter of atherosclerosis is exaggerated inflammatory proliferative reaction to the arterial wall damage. The oxidative stress phenomenon and infections with common pathogens play an undoubtful role in this process. Ultimately the direct damage is an effect of immune response cells infiltration and secretion of cytokines and proinflammatory factors. Among the cells of immune system responsible for formation and development of atheromatous plaque are considered: macrophages, dendritic cells, T and B lymphocytes, monocytes. Attention was also paid to the inflammatory mediators and growth factors. Scientist are interested in unstable atherosclerotic plaque and accompanying inflammatory process within the artery wall for a long time. Meanwhile, there are conducted researches on inflammation markers underlying the destabilisation of plaques. Revealing the role of these cells in evolution of atherosclerosis would enable more complex understanding of the mechanism of lesions development. Then it would facilitate an introduction of the new and upgraded methods of treatment and prevention. Also the progress of imaging examinations is meaningful for diagnostics and treatment. It is contributory to the choice of therapeutic strategy and assessment of surgical intervention urgency. In the clinical practice there are recognized standards of imaging the

How radiation influences atherosclerotic plaque development. A biophysical approach in ApoE{sup -/-} mice

Energy Technology Data Exchange (ETDEWEB)

Kloosterman, Astrid; Dillen, Teun van; Dekkers, Fieke [National Institute for Public Health and the Environment (RIVM), Centre for Environmental Safety and Security, Bilthoven (Netherlands); Bijwaard, Harmen [National Institute for Public Health and the Environment (RIVM), Centre for Environmental Safety and Security, Bilthoven (Netherlands); Inholland University of Applied Sciences, Medical Technology Research Group, Haarlem (Netherlands); Heeneman, Sylvia [Maastricht University Medical Center, Experimental Vascular Pathology group, Department of Pathology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); Hoving, Saske; Stewart, Fiona A. [Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Division of Biological Stress Response (H3), Amsterdam (Netherlands)

2017-11-15

Atherosclerosis is the development of lipid-laden plaques in arteries and is nowadays considered as an inflammatory disease. It has been shown that high doses of ionizing radiation, as used in radiotherapy, can increase the risk of development or progression of atherosclerosis. To elucidate the effects of radiation on atherosclerosis, we propose a mathematical model to describe radiation-promoted plaque development. This model distinguishes itself from other models by combining plaque initiation and plaque growth, and by incorporating information from biological experiments. It is based on two consecutive processes: a probabilistic dose-dependent plaque initiation process, followed by deterministic plaque growth. As a proof of principle, experimental plaque size data from carotid arteries from irradiated ApoE{sup -/-} mice was used to illustrate how this model can provide insight into the underlying biological processes. This analysis supports the promoting role for radiation in plaque initiation, but the model can easily be extended to include dose-related effects on plaque growth if available experimental data would point in that direction. Moreover, the model could assist in designing future biological experiments on this research topic. Additional biological data such as plaque size data from chronically-irradiated mice or experimental data sets with a larger variety in biological parameters can help to further unravel the influence of radiation on plaque development. To the authors' knowledge, this is the first biophysical model that combines probabilistic and mechanistic modeling which uses experimental data to investigate the influence of radiation on plaque development. (orig.)

Finite element modeling and intravascular ultrasound elastography of vulnerable plaques: parameter variation.

NARCIS (Netherlands)

Baldewsing, R.A.; Korte, C.L. de; Schaar, J.A.; Mastik, F.; Steen, A.F.W. van der

2004-01-01

BACKGROUND AND GOAL: More than 60% of all myocardial infarction is caused by rupture of a vulnerable plaque. A vulnerable plaque can be described as a large, soft lipid pool covered by a thin fibrous cap. Plaque material composition, geometry, and inflammation caused by infiltration of macrophages

Optimization of 125I ophthalmic plaque brachytherapy

International Nuclear Information System (INIS)

Astrahan, M.A.; Luxton, G.; Jozsef, G.; Liggett, P.E.; Petrovich, Z.

1990-01-01

Episcleral plaques containing 125 I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged

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

International Nuclear Information System (INIS)

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

1983-01-01

Plaques formed by herpes simplex virus (HSV), pseudorabies virus, and varicella-zoster virus were studied by plaque autoradiography after [ 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

Natural history of dental plaque accumulation in mechanically ventilated adults: a descriptive correlational study.

Science.gov (United States)

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

2011-12-01

The purpose of this study was to describe the pattern of dental plaque accumulation in mechanically ventilated adults. Accumulation of dental plaque and bacterial colonisation of the oropharynx is associated with a number of systemic diseases including ventilator associated pneumonia. 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 analysed. Medical respiratory, surgical trauma and neuroscience ICU's of a large tertiary care centre in the southeast United States. 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). 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 visualise 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. Published by Elsevier Ltd.

Clear Plaque Mutants of Lactococcal Phage TP901-1

DEFF Research Database (Denmark)

Kot, Witold; Kilstrup, Mogens; Vogensen, Finn K.

2016-01-01

We report a method for obtaining turbid plaques of the lactococcal bacteriophage TP901-1 and its derivative TP901-BC1034. We have further used the method to isolate clear plaque mutants of this phage. Analysis of 8 such mutants that were unable to lysogenize the host included whole genome...

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

OpenAIRE

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

2013-01-01

Local hemodynamic forces, such as wall shear stress, are thought to trigger cellular and molecular mechanisms that determine atherosclerotic plaque vulnerability to rupture. Magnetic resonance imaging (MRI) has emerged as a powerful tool to characterize human carotid atherosclerotic plaque composition and morphology, and to identify plaque features shown to be key determinants of plaque vulnerability. Image-based computational fluid dynamics (CFD) has allowed researchers to obtain time-resolv...

Cell proliferation in the atherosclerotic plaques of cholesterol-fed rabbits

International Nuclear Information System (INIS)

Cavallero, C.; Tondo, U. di; Mingazinni, P.L.; Nicosia, R.; Pericoli, M.N.; Sarti, P.; Spagnoli, L.G.; Villaschi, S.

1976-01-01

Tritiated thymidine radioautography was employed to study the effect of cortisol and other glucocorticoids on cellular proliferation in the aorta and pulmonary artery of rabbits with cholesterol atherosclerosis. Labelled cell counts showed that glucocorticoids, even after one day and at a relatively low dose, decrease sharply the deoxyribonucleic acid synthesis in the intimal plaques. The hormonal influence on [ 3 H] thymidine uptake seems to be a dose-dependent process. The relative potency of these steroids in inhibiting DNA synthesis in the plaques parallels closely their anti-inflammatory effectiveness. Conversely mineralocorticoids, including aldosterone and deoxycorticosterone, increase the rate of DNA synthesis in the plaques. It is concluded that the anti-atherogenic effect of glucocorticoids on cholesterol-fed rabbits may be due, at least partly, to the inhibitory effect of these steroids on the DNA synthesis of the cellular components of the intimal plaques

Plaque removal efficacy of a battery-operated toothbrush compared to a manual toothbrush.

Science.gov (United States)

Ruhlman, C D; Bartizek, R D; Biesbrock, A R

2001-08-01

Recently, a new power toothbrush has been marketed with a design that fundamentally differs from other marketed power toothbrushes, in that it incorporates a round oscillating head, in conjunction with fixed bristles. The objective of this study was to compare the plaque removal efficacy of a control manual toothbrush (Colgate Navigator) to this experimental power toothbrush (Crest SpinBrush) following a single use. This study was a randomized, controlled, examiner-blind, 4-period crossover design which examined plaque removal with the two toothbrushes following a single use in 40 completed subjects. Plaque was scored before and after brushing using the Turesky Modification of the Quigley-Hein Index. Baseline plaque scores were 1.77 for both the experimental toothbrush and control toothbrush treatment groups. With respect to all surfaces examined, the experimental toothbrush delivered an adjusted (via analysis of covariance) mean difference between baseline and post-brushing plaque scores of 0.48 while the control toothbrush delivered an adjusted mean difference of 0.35. The experimental toothbrush removed, on average, 37.6% more plaque than the control toothbrush. These results were statistically significant (P< 0.001). With respect to buccal surfaces, the experimental toothbrush delivered an adjusted mean difference between baseline and post-brushing plaque scores of 0.54 while the control toothbrush delivered an adjusted mean difference of 0.42. This represents 27.8% more plaque removal with the experimental toothbrush compared to the control toothbrush. These results were also statistically significant (P= 0.001). Results on lingual surfaces also demonstrated statistically significantly (P< 0.001) greater plaque removal for the experimental toothbrush with an average of 53.4% more plaque removal.

PCA-based polling strategy in machine learning framework for coronary artery disease risk assessment in intravascular ultrasound: A link between carotid and coronary grayscale plaque morphology.

Science.gov (United States)

Araki, Tadashi; Ikeda, Nobutaka; Shukla, Devarshi; Jain, Pankaj K; Londhe, Narendra D; Shrivastava, Vimal K; Banchhor, Sumit K; Saba, Luca; Nicolaides, Andrew; Shafique, Shoaib; Laird, John R; Suri, Jasjit S

2016-05-01

Percutaneous coronary interventional procedures need advance planning prior to stenting or an endarterectomy. Cardiologists use intravascular ultrasound (IVUS) for screening, risk assessment and stratification of coronary artery disease (CAD). We hypothesize that plaque components are vulnerable to rupture due to plaque progression. Currently, there are no standard grayscale IVUS tools for risk assessment of plaque rupture. This paper presents a novel strategy for risk stratification based on plaque morphology embedded with principal component analysis (PCA) for plaque feature dimensionality reduction and dominant feature selection technique. The risk assessment utilizes 56 grayscale coronary features in a machine learning framework while linking information from carotid and coronary plaque burdens due to their common genetic makeup. This system consists of a machine learning paradigm which uses a support vector machine (SVM) combined with PCA for optimal and dominant coronary artery morphological feature extraction. Carotid artery proven intima-media thickness (cIMT) biomarker is adapted as a gold standard during the training phase of the machine learning system. For the performance evaluation, K-fold cross validation protocol is adapted with 20 trials per fold. For choosing the dominant features out of the 56 grayscale features, a polling strategy of PCA is adapted where the original value of the features is unaltered. Different protocols are designed for establishing the stability and reliability criteria of the coronary risk assessment system (cRAS). Using the PCA-based machine learning paradigm and cross-validation protocol, a classification accuracy of 98.43% (AUC 0.98) with K=10 folds using an SVM radial basis function (RBF) kernel was achieved. A reliability index of 97.32% and machine learning stability criteria of 5% were met for the cRAS. This is the first Computer aided design (CADx) system of its kind that is able to demonstrate the ability of coronary

A modified COMS plaque for iris melanoma

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Daniel J. Scanderbeg

2011-09-01

Full Text Available Melanoma of the iris is a rare condition compared to posterior ocular tumors and in this case report we presenta 51-year-old female patient with diffuse iris melanoma. Traditional COMS (Collaborative Ocular Melanoma Studyplaques are used at our institution for radiation therapy, so a novel modification of the traditional plaque was requiredto allow better conformance with placement on the cornea. The usual silastic insert was machined to dimensions incompliance with the cornea, placed without incident, and treatment delivered with excellent patient tolerance of themodified plaque.

Dynamic programming in parallel boundary detection with application to ultrasound intima-media segmentation.

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Zhou, Yuan; Cheng, Xinyao; Xu, Xiangyang; Song, Enmin

2013-12-01

Segmentation of carotid artery intima-media in longitudinal ultrasound images for measuring its thickness to predict cardiovascular diseases can be simplified as detecting two nearly parallel boundaries within a certain distance range, when plaque with irregular shapes is not considered. In this paper, we improve the implementation of two dynamic programming (DP) based approaches to parallel boundary detection, dual dynamic programming (DDP) and piecewise linear dual dynamic programming (PL-DDP). Then, a novel DP based approach, dual line detection (DLD), which translates the original 2-D curve position to a 4-D parameter space representing two line segments in a local image segment, is proposed to solve the problem while maintaining efficiency and rotation invariance. To apply the DLD to ultrasound intima-media segmentation, it is imbedded in a framework that employs an edge map obtained from multiplication of the responses of two edge detectors with different scales and a coupled snake model that simultaneously deforms the two contours for maintaining parallelism. The experimental results on synthetic images and carotid arteries of clinical ultrasound images indicate improved performance of the proposed DLD compared to DDP and PL-DDP, with respect to accuracy and efficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

Ropes eye plaque brachytherapy dosimetry for two models of 103Pd seeds

International Nuclear Information System (INIS)

Saidi, P.; Sadeghi, M.; Shirazi, A.; Tenreiro, C.

2011-01-01

Full text: Brachytherapy dose distributions are calculated for I5 m m ROPES eye plaque loaded with model Theragenics200 and IR06-103Pd seeds. The effects of stainless steel backing and Acrylic insert on dose distribution along the central axis of the eye plaque and at critical ocular structure are investigated. Monte Carlo simulation was carried out with the Version 5 of the MCNP. The dose at critical ocular structure by considering the eye composition was calculated. Results are compared with the calculated data for CaMS eye plaque loaded with Theragenics200 palladium-103 seeds and model 6711 iodine-125 seed. The air kerma strength of the IR06- 103Pd seed to deliver 85 Gy in apex of tumor in water medium was calculated to be 4.10 U/seed. Along the central axis of stainless steel plaque loaded with new 103Pd seeds in Acrylic insert, the dose reduction relative to water is 6.9% at 5 mm (apex). Removal of the Acrylic insert from the plaque (replacing with water) did not make significantly difference in dose reduction results (O.2%). The presence of the stainless steel backing results in dose enhancement near the plaque relative to water. Doses at points of interest are higher for ROPES eye plaque when compared to CaMS eye plaque. The dosimetric parameters calculated in this work for the new palladium seed, showed that in dosimetry point of view, the IR06-103Pd seed is suitable for use in brachytherapy. The effect of Acrylic insert on dose distribution is negligible and the main effect on dose reduction is due to the presence of stainless steel plaque backing. (author)

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

NARCIS (Netherlands)

Bot, M.; , van, Berkel T.J.C.

2013-01-01

Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by

Paraclinical Effects of Miswak Extract on Dental Plaque

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Hamid Reza Poureslami

2007-01-01

Full Text Available Introduction: The Persian toothbrush tree or Miswak (Salvadora Persica L. has been used as a brushing stick for more than 1,300 years. Pharmacological studies indicated antibacterial and antiinflammatory activities of Miswak extract. The present study was performed to determine antibacterial effects of Miswak extract.Material and Methods: The present experimental research involved three in vitro studies including: 1 in vitro testing of the effect of Miswak extract on selected bacteria; 2 comparing the paraclinical effects of Iranian toothpaste containing Miswak extract and placebo toothpaste on dental plaque; and 3 comparing the antibacterial effect of Iranian toothpaste with Swiss toothpaste(Quail Miswak on dental plaque. The disc diffusion method was used to test bacterial sensitivity of toothpastes. Data were analyzed by paired t-test and ANOVA.Results: In the first study, Miswak extract inhibited the growth of some dental plaque bacteria. In the second study, antibacterial effect of the herbal toothpaste was significantly greater than that of the placebo (P =0.002. In the third study, four samples of dental plaque bacteria were used and there was no difference between the antibacterial effects of Swiss and Iranian herbal toothpastes (P =0.66.Conclusion: Due to antimicrobial effects of Miswak extract, its use in mouth rinses and toothpastes is highly recommended.

Association between Human Plasma Chondroitin Sulfate Isomers and Carotid Atherosclerotic Plaques

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Elisabetta Zinellu

2012-01-01

Full Text Available Several studies have evidenced variations in plasma glycosaminoglycans content in physiological and pathological conditions. In normal human plasma GAGs are present mainly as undersulfated chondroitin sulfate (CS. The aim of the present study was to evaluate possible correlations between plasma CS level/structure and the presence/typology of carotid atherosclerotic lesion. Plasma CS was purified from 46 control subjects and 47 patients undergoing carotid endarterectomy showing either a soft or a hard plaque. The concentration and structural characteristics of plasma CS were assessed by capillary electrophoresis of constituent unsaturated fluorophore-labeled disaccharides. Results showed that the concentration of total CS isomers was increased by 21.4% (P<0.01 in plasma of patients, due to a significant increase of undersulfated CS. Consequently, in patients the plasma CS charge density was significantly reduced with respect to that of controls. After sorting for plaque typology, we found that patients with soft plaques and those with hard ones differently contribute to the observed changes. In plasma from patients with soft plaques, the increase in CS content was not associated with modifications of its sulfation pattern. On the contrary, the presence of hard plaques was associated with CS sulfation pattern modifications in presence of quite normal total CS isomers levels. These results suggest that the plasma CS content and structure could be related to the presence and the typology of atherosclerotic plaque and could provide a useful diagnostic tool, as well as information on the molecular mechanisms responsible for plaque instability.

Plaque assay for human coronavirus NL63 using human colon carcinoma cells

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Drosten Christian

2008-11-01

Full Text Available Abstract Background Coronaviruses cause a broad range of diseases in animals and humans. Human coronavirus (hCoV NL63 is associated with up to 10% of common colds. Viral plaque assays enable the characterization of virus infectivity and allow for purifying virus stock solutions. They are essential for drug screening. Hitherto used cell cultures for hCoV-NL63 show low levels of virus replication and weak and diffuse cytopathogenic effects. It has not yet been possible to establish practicable plaque assays for this important human pathogen. Results 12 different cell cultures were tested for susceptibility to hCoV-NL63 infection. Human colon carcinoma cells (CaCo-2 replicated virus more than 100 fold more efficiently than commonly used African green monkey kidney cells (LLC-MK2. CaCo-2 cells showed cytopathogenic effects 4 days post infection. Avicel, agarose and carboxymethyl-cellulose overlays proved suitable for plaque assays. Best results were achieved with Avicel, which produced large and clear plaques from the 4th day of infection. The utility of plaque assays with agrose overlay was demonstrated for purifying virus, thereby increasing viral infectivity by 1 log 10 PFU/mL. Conclusion CaCo-2 cells support hCoV-NL63 better than LLC-MK2 cells and enable cytopathogenic plaque assays. Avicel overlay is favourable for plaque quantification, and agarose overlay is preferred for plaque purification. HCoV-NL63 virus stock of increased infectivity will be beneficial in antiviral screening, animal modelling of disease, and other experimental tasks.

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

Science.gov (United States)

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

2013-06-01

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.

Multidimensional segmentation of coronary intravascular ultrasound images using knowledge-based methods

Science.gov (United States)

Olszewski, Mark E.; Wahle, Andreas; Vigmostad, Sarah C.; Sonka, Milan

2005-04-01

In vivo studies of the relationships that exist among vascular geometry, plaque morphology, and hemodynamics have recently been made possible through the development of a system that accurately reconstructs coronary arteries imaged by x-ray angiography and intravascular ultrasound (IVUS) in three dimensions. Currently, the bottleneck of the system is the segmentation of the IVUS images. It is well known that IVUS images contain numerous artifacts from various sources. Previous attempts to create automated IVUS segmentation systems have suffered from either a cost function that does not include enough information, or from a non-optimal segmentation algorithm. The approach presented in this paper seeks to strengthen both of those weaknesses -- first by building a robust, knowledge-based cost function, and then by using a fully optimal, three-dimensional segmentation algorithm. The cost function contains three categories of information: a compendium of learned border patterns, information theoretic and statistical properties related to the imaging physics, and local image features. By combining these criteria in an optimal way, weaknesses associated with cost functions that only try to optimize a single criterion are minimized. This cost function is then used as the input to a fully optimal, three-dimensional, graph search-based segmentation algorithm. The resulting system has been validated against a set of manually traced IVUS image sets. Results did not show any bias, with a mean unsigned luminal border positioning error of 0.180 +/- 0.027 mm and an adventitial border positioning error of 0.200 +/- 0.069 mm.

A state-of-the-art review on segmentation algorithms in intravascular ultrasound (IVUS) images.

Science.gov (United States)

Katouzian, Amin; Angelini, Elsa D; Carlier, Stéphane G; Suri, Jasjit S; Navab, Nassir; Laine, Andrew F

2012-09-01

Over the past two decades, intravascular ultrasound (IVUS) image segmentation has remained a challenge for researchers while the use of this imaging modality is rapidly growing in catheterization procedures and in research studies. IVUS provides cross-sectional grayscale images of the arterial wall and the extent of atherosclerotic plaques with high spatial resolution in real time. In this paper, we review recently developed image processing methods for the detection of media-adventitia and luminal borders in IVUS images acquired with different transducers operating at frequencies ranging from 20 to 45 MHz. We discuss methodological challenges, lack of diversity in reported datasets, and weaknesses of quantification metrics that make IVUS segmentation still an open problem despite all efforts. In conclusion, we call for a common reference database, validation metrics, and ground-truth definition with which new and existing algorithms could be benchmarked.

SU-E-T-15: A Comparison of COMS and EP917 Eye Plaque Applicators Using Different Radionuclides

Energy Technology Data Exchange (ETDEWEB)

Aryal, P; Molloy, JA [University of Kentucky, Lexington, KY (United States); Rivard, MJ [Tufts University School of Medicine, Boston, MA (United States)

2015-06-15

Purpose: To investigate the effect of plaque design and radionuclides on eye plaque dosimetry. Methods: The Monte Carlo N-particle Code version 6 (MCNP6) was used for radiation transport simulations. The 14 mm and 16 mm diameter COMS plaques and the model EP917 plaque were simulated using brachytherapy seeds containing I-125, Pd-103, and Cs-131 radionuclides. The origin was placed at the scleral inner surface. The central axis (CAX) doses of both COMS plaques at −1 mm, 0 mm, 1 mm, 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, and 22.6 mm were compared to the model EP917 plaque. Dose volume histograms (DVHs) were also created for both COMS plaques for the tumor and outer sclera then compared to results for the model EP917 plaque. Results: For all radionuclides, the EP917 plaque delivered higher dose (max 343%) compared to the COMS plaques, except for the 14 mm COMS plaque with Cs-131 at 1 mm and 2 mm depths from outer sclera surface. This could be due to source design. For all radionuclides, the 14 mm COMS plaque delivered higher doses compared to the 16 mm COMS plaque for the depths up to 5 mm. Dose differences were not significant beyond depths of 10 mm due to ocular lateral scatter for the different plaque designs. Tumor DVHs for the 16 mm COMS plaque with Cs-131 provided better dose homogeneity and conformity compared to other COMS plaques with I-125 and Pd-103. Using Pd-103, DVHs for the 16 mm COMS plaque delivered less dose to outer sclera compared to other plaques. Conclusion: This study identified improved tumor homogeneity upon considering radionuclides and plaque designs, and found that scleral dose with the model EP917 plaque was higher than for the 16 mm COMS plaque for all the radionuclides studied.

Thrombus Burden of Deep Vein Thrombosis and Its Association with Thromboprophylaxis and D-Dimer Measurement: Insights from the APEX Trial.

Science.gov (United States)

Chi, Gerald; Goldhaber, Samuel Z; Hull, Russell D; Hernandez, Adrian F; Kerneis, Mathieu; Al Khalfan, Fahad; Cohen, Alexander T; Harrington, Robert A; Gibson, C Michael

2017-12-01

Background The aim of this study was to evaluate the effect of betrixaban on the occurrence of deep vein thrombosis (DVT) and also the extent of thrombus and to assess the association of baseline D-dimer with subsequent thrombus burden. Methods In the APEX trial (ClinicalTrials.gov: NCT01583218), 7,513 acutely ill hospitalized medical patients were randomly assigned to extended-duration betrixaban (35–42 days) or enoxaparin (10 ± 4 days). D-dimer concentration was measured at baseline, and mandatory lower-extremity compression ultrasonography (CUS) was performed at 35 to 42 days. The thrombus burden of DVT was assessed by the number of non-compressible vascular segments in six target proximal veins and compared between treatment groups and D-dimer categories (≥2 × upper limit of normal [ULN] versus thrombus burden (p = 0.012 for any-dose and p = 0.001 for full-dose). Elevated D-dimer at baseline was independently associated with a 2.12-fold increased risk of developing DVT (p thrombus burden was also observed in those with D-dimer ≥ 2 × ULN compared with venous segments with thrombosis at 35 to 42 days compared with enoxaparin. A positive D-dimer was associated with a greater extent of thrombus burden among acutely ill medical patients who developed DVT despite receiving thromboprophylaxis.

Current techniques for the investigation of vulnerable atherosclerotic plaques

International Nuclear Information System (INIS)

Riou, L.; Broisat, A.; Fagret, D.; Ghezzi, C.

2005-01-01

Atherosclerosis is the single most important contributor to cardiovascular diseases, the leading cause of death in industrialized countries. Atherosclerosis complications such as vulnerable coronary plaque rupture or erosion result in acute coronary events, i.e. myocardial infarction and sudden death. Vulnerable plaques initially develop eccentrically without impeding on the vessel lumen and are therefore not detectable using angiography. New techniques for the investigation of vulnerable plaques are needed to identify and treat vulnerable patients. Invasive techniques require the use of intracoronary probes and are thereby not applicable to large populations of patients. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are the most promising invasive modalities. They provide morphological data that could potentially be associated with a more functional approach such as thermography, elasto-graphy, or spectroscopy, Non-invasive techniques are better suited for studying larger populations of patients. Computed tomography is currently used for calcium scoring, but the biological meaning and the prognostic value of this index remain to be fully determined. Non-invasive coronary magnetic resonance imaging (MRI) faces numerous technical challenges, and it essentially provides morphological data. Molecular nuclear imaging offers a great sensitivity and the ability to provide metabolic data about atherosclerotic lesions. New potential tracers of vulnerable plaques are currently being evaluated. Nuclear Medicine should therefore play a major role in the future as a non invasive imaging modality for the assessment of vulnerable atherosclerotic plaques. (author)

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

Science.gov (United States)

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

2014-01-01

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

Review of ustekinumab, an interleukin-12 and interleukin-23 inhibitor used for the treatment of plaque psoriasis

Directory of Open Access Journals (Sweden)

Nora Koutruba

2010-03-01

Full Text Available Nora Koutruba, Jason Emer, Mark LebwohlMount Sinai School of Medicine, New York, USAAbstract: The pathogenesis of psoriasis is unknown, although it is generally accepted that this chronic inflammatory skin disorder is a complex autoimmune condition similar to other T-cell mediated disorders. Psoriasis imposes a heavy burden on the lifestyle of those affected due to the psychological, arthritic, and cutaneous morbidities; thus significant research has focused on the genetic and immunologic features of psoriasis in anticipation of more targeted, efficacious, and safe therapies. Recently, CD4+ T helper (Th 17 cells and interleukins (IL-12 and -23 have been important in the pathogenesis of T-cell mediated disorders such as psoriasis and has influenced the development of medications that specifically target these key immunological players. Ustekinumab is a monoclonal antibody belonging to a newly developed class of biological, anti-cytokine medications that notably targets the p40 subunit of both IL-12 and -23, both naturally occurring proteins that are important in regulating the immune system and are understood to play a role in immune-mediated inflammatory disorders. Ustekinumab’s safety and efficacy has been evaluated for the treatment of moderate-to-severe plaque psoriasis in 3 phase III clinical trials, 2 placebo-controlled (PHOENIX 1 and 2, and 1 comparator-controlled (ACCEPT study which proved advantageous in patients who were treatment-naive, previously failed other immunosuppressive medications including cyclosporine or methotrexate, were unresponsive to phototherapy, or were unable to use or tolerate other therapies. Ustekinumab has also been investigated for other indications such as psoriatic arthritis, Crohn’s disease, and relapsing/remitting multiple sclerosis. We present a concise review evaluating the evidence that supports the use of ustekinumab in the treatment of plaque psoriasis and other conditions.Keywords: ustekinumab

Compensatory enlargement of the left main coronary artery: insights from the PROSPECT study.

Science.gov (United States)

Inaba, Shinji; Mintz, Gary S; Shimizu, Takehisa; Weisz, Giora; Mehran, Roxana; Marso, Steven P; Xu, Ke; de Bruyne, Bernard; Serruys, Patrick W; Stone, Gregg W; Maehara, Akiko

2014-03-01

Glagov proposed that remodeling delayed development of significant coronary artery stenoses until plaque occupied, on average, 40% of arterial area (40% plaque burden). The aim of the current study was to confirm the previously proposed concept of coronary remodeling as first described by Glagov who studied postmortem left main coronary arteries (LMCAs). Using the in-vivo intravascular ultrasound data from the Providing Regional Observations to Study Predictors of Events in the Coronary Tree (PROSPECT) study, we evaluated 552 LMCAs in 552 patients. External elastic membrane cross-sectional areas (CSAs) increased in proportion to the increase in plaque and media CSAs (r=0.61, P40% plaque burden), there was an inverse relationship between lumen CSA and plaque burden (r=-0.57, PPROSPECT study patients. In addition, the present study suggested that plaque phenotype worsened with increasing LMCA plaque growth.

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

Science.gov (United States)

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

2014-06-01

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

[Innovative application of small molecules to influence -pathogenicity of dental plaque].

Science.gov (United States)

Janus, M M; Volgenant, C M C; Krom, B P

2018-05-01

Current preventive measures against infectious oral diseases are mainly focussed on plaque removal and promoting a healthy lifestyle. This in vitro study investigated a third preventive method: maintaining healthy dental plaque with the use of small molecules. As a model of dental plaque, in vitro biofilms were cultivated under conditions that induce pathogenic characteristics. The effect of erythritol and other small molecules on the pathogenic characteristics and bacterial composition of the biofilm was evaluated. The artificial sweetener erythritol and the molecule 3-Oxo-N-(2-oxycyclohexyl)dodecanamide (3-Oxo-N) had no clinically relevant effect on total biofilm formation. Erythritol did, however, lower the gingivitis related protease activity of the biofilm, while 3-Oxo-N blocked the caries related lactic acid accumulation. Furthermore, both substances ensured the biofilm maintained a young, non-pathogenic microbial composition. This shows it is possible to influence the dental plaque in a positive manner in vitro with the help of small molecules. Further research is necessary before this manipulation of dental plaque can be applied.

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

Science.gov (United States)

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

2014-09-01

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

Protein components in saliva and plaque fluid from irradiated primates

Energy Technology Data Exchange (ETDEWEB)

Edgar, W.M.; Bowen, W.H.; Cole, M.F. (Caries Prevention and Research Branch, National Caries Program, NIDR, Bethesda, Maryland, USA)

1982-01-01

Irradiation of the major salivary glands of monkeys (Macaca mulatta) fed cariogenic diets leads to caries clinically indistinguishable from radiation caries in man. This study compares the organic compostion of individual samples of plaque fluid and saliva from irradiated and control monkeys receiving the same cariogenic diet. Plaque and saliva were collected from fasting, tranquillised animals. Four irradiated animals were sampled repeatedly as were non-irradiated controls. Total protein, albumin, immunoglobulins A, G, and M, and the third component of complement (C'3) were quantitated in plaque fluid and whole saliva. Salivary amylase and peroxidase activities were also determined. Plaque fluid and saliva samples were also subjected to polyacrylamide gel electrophoresis. The total viable anaerobic count and numbers of Streptococcus mutans were determined in samples of plaque. The results suggest that the major effect of irradiation leading to increased numbers of S. mutans and caries susceptibility is in the amount, and not the composition, of the saliva produced by the residual gland tissue. The scanty flow of saliva may reduce the effectiveness of cleansing, buffering and lubrication mechanisms as well as resulting in a marked reduction in the total amount of specific and non-specific immune factors entering the mouth.

Protein components in saliva and plaque fluid from irradiated primates

International Nuclear Information System (INIS)

Edgar, W.M.; Bowen, W.H.; Cole, M.F.

1982-01-01

Irradiation of the major salivary glands of monkeys (Macaca mulatta) fed cariogenic diets leads to caries clinically indistinguishable from radiation caries in man. This study compares the organic compostion of individual samples of plaque fluid and saliva from irradiated and control monkeys receiving the same cariogenic diet. Plaque and saliva were collected from fasting, tranquillised animals. Four irradiated animals were sampled repeatedly as were non-irradiated controls. Total protein, albumin, immunoglobulins A, G, and M, and the third component of complement (C'3) were quantitated in plaque fluid and whole saliva. Salivary amylase and peroxidase activities were also determined. Plaque fluid and saliva samples were also subjected to polyacrylamide gel electrophoresis. The total viable anaerobic count and numbers of Streptococcus mutans were determined in samples of plaque. The results suggest that the major effect of irradiation leading to increased numbers of S. mutans and caries susceptibility is in the amount, and not the composition, of the saliva produced by the residual gland tissue. The scanty flow of saliva may reduce the effectiveness of cleansing, buffering and lubrication mechanisms as well as resulting in a marked reduction in the total amount of specific and non-specific immune factors entering the mouth. (author)

Protein components in saliva and plaque fluid from irradiated primates

Energy Technology Data Exchange (ETDEWEB)

Edgar, W M; Bowen, W H; Cole, M F [Caries Prevention and Research Branch, National Caries Program, NIDR, Bethesda, Maryland, USA

1982-01-01

Irradiation of the major salivary glands of monkeys (Macaca mulatta) fed cariogenic diets leads to caries clinically indistinguishable from radiation caries in man. This study compares the organic compostion of individual samples of plaque fluid and saliva from irradiated and control monkeys receiving the same cariogenic diet. Plaque and saliva were collected from fasting, tranquillised animals. Four irradiated animals were sampled repeatedly as were non-irradiated controls. Total protein, albumin, immunoglobulins A, G, and M, and the third component of complement (C'3) were quantitated in plaque fluid and whole saliva. Salivary amylase and peroxidase activities were also determined. Plaque fluid and saliva samples were also subjected to polyacrylamide gel electrophoresis. The total viable anaerobic count and numbers of Streptococcus mutans were determined in samples of plaque. The results suggest that the major effect of irradiation leading to increased numbers of S. mutans and caries susceptibility is in the amount, and not the composition, of the saliva produced by the residual gland tissue. The scanty flow of saliva may reduce the effectiveness of cleansing, buffering and lubrication mechanisms as well as resulting in a marked reduction in the total amount of specific and non-specific immune factors entering the mouth.

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

Science.gov (United States)

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

2012-03-01

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

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

Science.gov (United States)

Barrett, Hilary E; Mulvihill, John J; Cunnane, Eoghan M; Walsh, Michael T

2015-01-01

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

Progressive epicardial coronary blood flow reduction fails to produce ST-segment depression at normal heart rates.

Science.gov (United States)

de Chantal, Marilyn; Diodati, Jean G; Nasmith, James B; Amyot, Robert; LeBlanc, A Robert; Schampaert, Erick; Pharand, Chantal

2006-12-01

ST-segment depression is commonly seen in patients with acute coronary syndromes. Most authors have attributed it to transient reductions in coronary blood flow due to nonocclusive thrombus formation on a disrupted atherosclerotic plaque and dynamic focal vasospasm at the site of coronary artery stenosis. However, ST-segment depression was never reproduced in classic animal models of coronary stenosis without the presence of tachycardia. We hypothesized that ST-segment depression occurring during acute coronary syndromes is not entirely explained by changes in epicardial coronary artery resistance and thus evaluated the effect of a slow, progressive epicardial coronary artery occlusion on the ECG and regional myocardial blood flow in anesthetized pigs. Slow, progressive occlusion over 72 min (SD 27) of the left anterior descending coronary artery in 20 anesthetized pigs led to a 90% decrease in coronary blood flow and the development of ST-segment elevation associated with homogeneous and transmural myocardial blood flow reductions, confirmed by microspheres and myocardial contrast echocardiography. ST-segment depression was not observed in any ECG lead before the development of ST-segment elevation. At normal heart rates, progressive epicardial stenosis of a coronary artery results in myocardial ischemia associated with homogeneous, transmural reduction in regional myocardial blood flow and ST-segment elevation, without preceding ST-segment depression. Thus, in coronary syndromes with ST-segment depression and predominant subendocardial ischemia, factors other than mere increases in epicardial coronary resistance must be invoked to explain the heterogeneous parietal distribution of flow and associated ECG changes.

Evidence for xylitol 5-P production in human dental plaque

Energy Technology Data Exchange (ETDEWEB)

Waaler, S.M. (Department of Preclinical Techniques and Material Sciences and Department of Pedodontics, Dental Faculty, University of Oslo, Oslo (Norway))

1992-01-01

The Turku sugar studies indicated that xylitol may possess a caries-therapeutic effect. More recent data show that xylotol exhibits a bacteriostatic activity on a wide range of bacteria based on uptake and expulsion of xylitol. Intracellular xylitol 5-P appears to be a key substance associated with inhibition of bacterial metabolism by xylitol. This has been shown in studies with pure strains of bacteria, mainly Streptococcus mutans. The aim of the present study was to examine if production of xylitol 5-P occurs in freshly collected dental plaque which is exposed to labeled xylitol. Plaque extracts were analyzed by thin-layer chromatography combined with autoradiography and high performance liquid chromatography. Strong indications were obtained that xylitol 5-P is readily produced by dental plaque. No other significant xylitol metabolites were identified. The bacteriostatic properties of xylitol in plaque are a mechanism which may well account for the caries-therapeutic effect of xylitol. (au).

Guselkumab for the treatment of moderate-to-severe plaque psoriasis.

Science.gov (United States)

Yang, Eric J; Sanchez, Isabelle M; Beck, Kristen; Sekhon, Sahil; Wu, Jashin J; Bhutani, Tina

2018-04-01

Guselkumab is a human monoclonal antibody targeting the p19 subunit of IL-23 that has been approved for the treatment of adult patients with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy. This medication blocks the IL-23/IL-17 axis, which has been implicated in playing a key role in the pathogenesis of psoriasis. Areas covered: This review outlines the pharmacologic properties, safety, and efficacy of guselkumab for the treatment of plaque psoriasis. Expert commentary: Guselkumab is the first IL-23 specific inhibitor to be approved for the treatment of plaque psoriasis. Phase II and III clinical trial results have demonstrated excellent safety and efficacy of guselkumab. IL-23 inhibitors may offer potential benefits over existing therapies for moderate-to-severe plaque psoriasis in terms of safety, frequency of administration, and efficacy. Long-term safety data will be critical in evaluating the role of guselkumab in the treatment of psoriasis.

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

Science.gov (United States)

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

2009-03-01

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

MR Microimaging of amyloid plaques in Alzheimer's disease transgenic mice

International Nuclear Information System (INIS)

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

2008-01-01

Alzheimer's disease (AD) is the most prevalent neurological condition affecting industrialized nations and will rapidly become a healthcare crisis as the population ages. Currently, the post-mortem histological observation of amyloid plaques and neurofibrillary tangles is the only definitive diagnosis available for AD. A pre-mortem biological or physiological marker specific for AD used in conjunction with current neurological and memory testing could add a great deal of confidence to the diagnosis of AD and potentially allow therapeutic intervention much earlier in the disease process. Our group has developed MRI techniques to detect individual amyloid plaques in AD transgenic mouse brain in vivo. We are also developing contrast-enhancing agents to increase the specificity of detection of amyloid plaques. Such in vivo imaging of amyloid plaques will also allow the evaluation of anti-amyloid therapies being developed by the pharmaceutical industry in pre-clinical trials of AD transgenic mice. This short review briefly discusses our progress in these areas. (orig.)

Evidence for xylitol 5-P production in human dental plaque

International Nuclear Information System (INIS)

Waaler, S.M.

1992-01-01

The Turku sugar studies indicated that xylitol may possess a caries-therapeutic effect. More recent data show that xylotol exhibits a bacteriostatic activity on a wide range of bacteria based on uptake and expulsion of xylitol. Intracellular xylitol 5-P appears to be a key substance associated with inhibition of bacterial metabolism by xylitol. This has been shown in studies with pure strains of bacteria, mainly Streptococcus mutans. The aim of the present study was to examine if production of xylitol 5-P occurs in freshly collected dental plaque which is exposed to labeled xylitol. Plaque extracts were analyzed by thin-layer chromatography combined with autoradiography and high performance liquid chromatography. Strong indications were obtained that xylitol 5-P is readily produced by dental plaque. No other significant xylitol metabolites were identified. The bacteriostatic properties of xylitol in plaque are a mechanism which may well account for the caries-therapeutic effect of xylitol. (au)

Pleural plaques in Sweden among immigrants from Finland - with an editorial note

Energy Technology Data Exchange (ETDEWEB)

Hillerdal, G.

1983-07-01

In the county of Uppsala, Sweden, all detected cases of pleural plaques have been investigated with reference to asbestos exposure. Up to June, 1981, the number of men found to have pleural plaques were 1030 and the number of women 42. A disproportionately high percentage, especially of the women and the younger men, were born in Finland. Also, the Finnish-born had been exposed to asbestos to a significantly lower degree. They came from all parts of Finland - not only from the area where anthophyllite asbestos is found and where endemic plaques are common. Thus, some other factor must have caused these plaques among the Finns.

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

Science.gov (United States)

Wang, Shuang-shuang; Hu, Si-wang; Zhang, Qing-hua; Xia, Ai-xiang; Jiang, Zhi-xin; Chen, Xiao-min

2015-01-01

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

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

Directory of Open Access Journals (Sweden)

Shuang-shuang Wang

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

Enhancement of plaque removal by baking soda toothpastes from less accessible areas in the dentition.

Science.gov (United States)

Thong, S; Hooper, W; Xu, Y; Ghassemi, A; Winston, A

2011-01-01

To determine if baking soda toothpastes are relatively more effective than non-baking soda toothpastes in promoting plaque removal from less accessible sites in the dentition. Several single-brushing comparisons of baking soda and non-baking soda toothpastes for their overall ability to remove plaque have been published. In this study, individual comparisons of these published data, comparing the plaque removal performance of baking soda and non-baking soda toothpastes at various sites in the dentition, were examined to see if there were any site-dependant performance trends. The site-specific single-brushing data were then combined and analyzed in two ways. Meta-analyses of the clinical studies were performed to compare baking soda's relative plaque removal advantage at various sites in the mouth using paired t-testing at p baking soda toothpastes were graphically compared with plaque index reductions due to brushing with non-baking soda dentifrices. The percent relative plaque removal advantage for baking soda toothpastes at various sites were plotted against the reduction in plaque index due to brushing with non-baking soda toothpastes. Individual comparisons showed that brushing with the toothpastes containing baking soda generally removed significantly more plaque from each site than brushing with toothpastes without baking soda. The relative efficacy advantage for baking soda toothpastes was consistently higher at sites where the non-baking soda toothpastes removed less plaque. Meta-analytical comparisons confirmed baking soda toothpastes to be relatively more effective in enhancing plaque removal from sites where less plaque was removed compared to brushing with non-baking soda toothpastes (p baking soda toothpastes' relative plaque removal advantage could be seen to increase hyperbolically with decreasing plaque removal by the non-baking soda toothpastes with which they were compared. We presuppose that the reason less plaque is removed by non-baking soda

Effects of Hyperthyroidism on Coronary Artery Disease: A Computed Tomography Angiography Study.

Science.gov (United States)

Beyer, Christoph; Plank, Fabian; Friedrich, Guy; Wildauer, Matthias; Feuchtner, Gudrun

2017-10-01

Changes in thyroid hormone concentration can negatively affect the cardiovascular system. Subclinical hyperthyroidism has been linked to an increase of cardiovascular heart disease, however, clinical effects and significance are still uncertain. Therefore, we analyzed coronary computed tomography angiographies of patients with overt and subclinical hyperthyroidism for quantitative parameters and plaque morphology. Seven hundred forty-four (47.1% female) patients who underwent coronary computed tomography angiography were stratified into 3 groups: 51 patients with overt, 74 patients with subclinical hyperthyroidism, and 619 patients with euthyroidism. Analysis included grades of stenosis (no stenosis = 0, mild 70%) and plaque types (noncalcified, mixed, and calcified), segment involvement score (SIS), noncalcified SIS, and high-risk plaque features (napkin ring sign, low attenuation plaque, spotty calcifications, positive remodelling). Patients with overt and subclinical hyperthyroidism had more high-grade stenoses (39.2% vs 37.8% vs 24.2%; P = 0.007) and a higher coronary calcium score (456.5 vs 199.5 vs 155.9; P hyperthyroidism, followed by those with subclinical hyperthyroidism, had the most high-risk plaque features: napkin ring (21.6% vs 9.5% vs 6.0%, P hyperthyroid patients. Patients with subclinical and overt hyperthyroidism showed more high-grade coronary stenoses, plaque burden, and high-risk plaque features than patients with euthyroidism, which indicates that an increase of thyroid hormones might lead to coronary vascular degeneration and plaque instability. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Mathematical modeling of atherosclerotic plaque destabilization: Role of neovascularization and intraplaque hemorrhage.

Science.gov (United States)

Guo, Muyi; Cai, Yan; Yao, Xinke; Li, Zhiyong

2018-08-07

Observational studies have identified angiogenesis from the adventitial vasa vasorum and intraplaque hemorrhage (IPH) as critical factors in atherosclerotic plaque progression and destabilization. Here we propose a mathematical model incorporating intraplaque neovascularization and hemodynamic calculation with plaque destabilization for the quantitative evaluation of the role of neoangiogenesis and IPH in the vulnerable atherosclerotic plaque formation. An angiogenic microvasculature is generated by two-dimensional nine-point discretization of endothelial cell proliferation and migration from the vasa vasorum. Three key cells (endothelial cells, smooth muscle cells and macrophages) and three key chemicals (vascular endothelial growth factors, extracellular matrix and matrix metalloproteinase) are involved in the plaque progression model, and described by the reaction-diffusion partial differential equations. The hemodynamic calculation of the microcirculation on the generated microvessel network is carried out by coupling the intravascular, interstitial and transvascular flow. The plasma concentration in the interstitial domain is defined as the description of IPH area according to the diffusion and convection with the interstitial fluid flow, as well as the extravascular movement across the leaky vessel wall. The simulation results demonstrate a series of pathophysiological phenomena during the vulnerable progression of an atherosclerotic plaque, including the expanding necrotic core, the exacerbated inflammation, the high microvessel density (MVD) region at the shoulder areas, the transvascular flow through the capillary wall and the IPH. The important role of IPH in the plaque destabilization is evidenced by simulations with varied model parameters. It is found that the IPH can significantly speed up the plaque vulnerability by increasing necrotic core and thinning fibrous cap. In addition, the decreased MVD and vessel permeability may slow down the process of

Cryotherapy increases features of plaque stability in atherosclerotic rabbits.

Science.gov (United States)

Verheye, Stefan; Roth, Lynn; De Meyer, Inge; Van Hove, Cor E; Nahon, Daniel; Santoianni, Domenic; Yianni, John; Martinet, Wim; Buchbinder, Maurice; De Meyer, Guido R Y

2016-08-20

In the last 10 years, cryotherapy has been investigated as a new technology to treat vascular disease. The efficiency of cryotherapy in stabilising atherosclerotic plaques has never been described. The purpose of the present study was to evaluate the effect of catheter-based cryotherapy on atherosclerotic plaque composition in a rabbit model of atherosclerosis. Twenty-four New Zealand white rabbits were fed a 0.3% cholesterol-supplemented diet for 24 weeks. At two predefined sites of the atherosclerotic thoracic aorta, catheter-based cryotherapy, applying either single-dose, double-dose cryotherapy or control inflation, was performed after randomisation. Rabbits were continued on a cholesterol-supplemented diet for one day (acute) or four weeks (chronic). One day after cryotherapy, apoptotic cell death of smooth muscle cells (SMCs) and endothelial cells (ECs) was observed, whereas macrophages were unaffected. Four weeks later, the amount of SMCs was restored, the EC layer was regenerated, and a subendothelial macrophage-free layer was formed, indicative of a more stable plaque. In addition, both the thickness and the type I collagen content of the fibrous cap were increased. The present study demonstrated that cryotherapy is feasible and appears to stabilise atherosclerotic plaques in a rabbit model.

Study of isodose curves of an eye brachytherapy plaque

Energy Technology Data Exchange (ETDEWEB)

Costa, Marcos R.O.; Mourao, Arnaldo P., E-mail: marcos.robertto@hotmail.com, E-mail: seg@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Grynberg, Suely E., E-mail: aprata@des.cefetmg.br [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar

2015-07-01

The use eye plaque brachytherapy for intraocular tumors treatment is a process designed to protect healthy eye structures, as well as visual functions. It replaces enucleation when possible. The knowledge of the dose spatial distribution inside the eyeball and adjacent structures is very important to obtain the therapeutic dose, minimize the side effects and ensure efficiency in the process. Small variations in positioning the plaque on the ocular surface may generate a less effective treatment. Thus, in this work an eyeball phantom and a seed accommodation system similar to a commercially eye plaque model ROPES with diameter of 15 mm, were developed both in solid water Gammex 457 to conduct the study of the possible variation in the dose deposition inside the eye phantom. Radiochromic films were used to record isodose curves of two orthogonal plans within the simulator. The results showed that there is a difference in the dose deposition for the two orthogonal plans studied. This difference is 8.33% higher for the maximum dose value. Thus, a difference in dose that occurs due to the asymmetrical distribution of seeds on the eye plaque may interfere with the treatment, making it less effective. (author)

Study of isodose curves of an eye brachytherapy plaque

International Nuclear Information System (INIS)

Costa, Marcos R.O.; Mourao, Arnaldo P.; Grynberg, Suely E.

2015-01-01

The use eye plaque brachytherapy for intraocular tumors treatment is a process designed to protect healthy eye structures, as well as visual functions. It replaces enucleation when possible. The knowledge of the dose spatial distribution inside the eyeball and adjacent structures is very important to obtain the therapeutic dose, minimize the side effects and ensure efficiency in the process. Small variations in positioning the plaque on the ocular surface may generate a less effective treatment. Thus, in this work an eyeball phantom and a seed accommodation system similar to a commercially eye plaque model ROPES with diameter of 15 mm, were developed both in solid water Gammex 457 to conduct the study of the possible variation in the dose deposition inside the eye phantom. Radiochromic films were used to record isodose curves of two orthogonal plans within the simulator. The results showed that there is a difference in the dose deposition for the two orthogonal plans studied. This difference is 8.33% higher for the maximum dose value. Thus, a difference in dose that occurs due to the asymmetrical distribution of seeds on the eye plaque may interfere with the treatment, making it less effective. (author)

Intravascular Photoacoustic Imaging : A New Tool for Vulnerable Plaque Identification

NARCIS (Netherlands)

Jansen, K.; Van Soest, G.; Van der Steen, A.F.W.

2014-01-01

The vulnerable atherosclerotic plaque is believed to be at the root of the majority of acute coronary events. Even though the exact origins of plaque vulnerability remain elusive, the thin-cap fibroatheroma, characterized by a lipid-rich necrotic core covered by a thin fibrous cap, is considered to

Detection of attenuated plaque in stable angina with 64-multidetector computed tomography: a comparison with intravascular ultrasound.

Science.gov (United States)

Jinzaki, Masahiro; Okabe, Teruo; Endo, Ayaka; Kawamura, Akio; Koga, Seiko; Yamada, Minoru; Fukuda, Keiichi; Kuribayashi, Sachio

2012-01-01

To clarify multidetector computed tomography (MDCT) findings of attenuated plaque detected by intravascular ultrasound (IVUS). One hundred and fifty-four patients with stable angina underwent MDCT before IVUS. The attenuated plaque was identified in the targeted artery with IVUS, and the same artery was analyzed with MDCT for the presence of a high density area (HDA) >130 Hounsfield units (HU), and a low density area (LDA) HDA in attenuated plaque was compared with that in calcified plaque. Ten attenuated plaques and 15 calcified plaques were identified in 9 of 154 patients (males=9, 66.2 ± 9.5 years). Eight of the 10 attenuated plaques and all 15 calcified plaques were accompanied with a HDA on MDCT. The HDA ranged from 174 to 667 HU (mean 389.0 ± 148.3 HU) in the 8 attenuated plaques, and from 545 to 1,205 HU (mean 920.9 ± 215.9 HU) in 15 calcified plaques. There was a significant difference in CT density of the HDA between the attenuated and calcified plaque (PHDA. MDCT has the ability to demonstrate attenuated plaque as the combination of HDA (approximately 400 HU on average) and LDA HDA can be differentiated from calcified plaque by its lower CT density value.

Efficacy of Methotrexate in patients with plaque type psoriasis

Science.gov (United States)

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

2014-01-01

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

Contrast-enhanced magnetic resonance imaging for the detection of ruptured coronary plaques in patients with acute myocardial infarction.

Directory of Open Access Journals (Sweden)

Christian H P Jansen

Full Text Available X-ray coronary angiography (XCA is the current gold standard for the assessment of lumen encroaching coronary stenosis but XCA does not allow for early detection of rupture-prone vulnerable plaques, which are thought to be the precursor lesions of most acute myocardial infarctions (AMI and sudden death. The aim of this study was to investigate the potential of delayed contrast-enhanced magnetic resonance coronary vessel wall imaging (CE-MRCVI for the detection of culprit lesions in the coronary arteries.16 patients (13 male, age 61.9±8.6 years presenting with sub-acute MI underwent CE-MRCVI within 24-72h prior to invasive XCA. CE-MRCVI was performed using a T1-weighted 3D gradient echo inversion recovery sequence (3D IR TFE 40±4 minutes following the administration of 0.2 mmol/kg gadolinium-diethylenetriamine-pentaacetic acid (DTPA on a 3T MRI scanner equipped with a 32-channel cardiac coil.14 patients were found to have culprit lesions (7x LAD, 1xLCX, 6xRCA as identified by XCA. Quantitative CE-MRCVI correctly identified the culprit lesion location with a sensitivity of 79% and excluded culprit lesion formation with a specificity of 99%. The contrast to noise ratio (CNR of culprit lesions (9.7±4.1 significantly exceeded CNR values of segments without culprit lesions (2.9±1.9, p<0.001.CE-MRCVI allows the selective visualization of culprit lesions in patients immediately after myocardial infarction (MI. The pronounced contrast uptake in ruptured plaques may represent a surrogate biomarker of plaque activity and/or vulnerability.

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

Directory of Open Access Journals (Sweden)

Takashi Kubo

2011-01-01

Full Text Available 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%, <0.001, thin-cap fibroatheroma (48% versus 16%, <0.001, plaque rupture (44% versus 11%, <0.001, and intracoronary thrombus (54% versus 17%, <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.

Quantification of arterial plaque and lumen density with MDCT

International Nuclear Information System (INIS)

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

2010-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2012-01-01

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

Microglia in diffuse plaques in hereditary cerebral hemorrhage with amyloidosis (Dutch). An immunohistochemical study.

Science.gov (United States)

Maat-Schieman, M L; Rozemuller, A J; van Duinen, S G; Haan, J; Eikelenboom, P; Roos, R A

1994-09-01

In hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D) beta/A4 amyloid deposition is found in meningocortical blood vessels and in diffuse plaques in the cerebral cortex. Diffuse plaques putatively represent early stages in the formation of senile plaques. Microglia are intimately associated with congophilic plaques in Alzheimer's disease (AD), but microglial involvement in diffuse plaque formation is controversial. Therefore, we studied the relationship between microglia and diffuse plaques in the cerebral cortex of four patients with HCHWA-D using a panel of macrophage/microglia markers (mAbs LCA, LeuM5, LeuM3, LN3, KP1, OKIa, CLB54, Mac1, Ki-M6, AMC30 and the lectin RCA-1). Eight AD patients, one demented Down's syndrome (DS) patient and four non-demented controls were included for comparison. In controls and HCHWA-D patients ramified or "resting" microglia formed a reticular array in cortical gray and subcortical white matter. Microglial cells in or near HCHWA-D diffuse plaques retained their normal regular spacing and ramified morphology. In AD/DS gray matter more microglial cells were stained than in controls and HCHWA-D patients. Intensely immunoreactive microglia with enlarged cell bodies and short, thick processes clustered in congophilic plaques. In contrast to the resting microglia, these "activated microglia" strongly expressed class II major histocompatibility complex antigen, HLA-DR, and were AMC30-immunoreactive. These findings support the view that microglia play a role in the formation of congophilic plaques but do not initiate diffuse plaque formation. Another finding in this study is the presence of strong monocyte/macrophage marker immunoreactivity in the wall of cortical congophilic blood vessels in HCHWA-D.

Optimization of sup 125 I ophthalmic plaque brachytherapy

Energy Technology Data Exchange (ETDEWEB)

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

1990-11-01

Episcleral plaques containing {sup 125}I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged.

Efficacy of triphala mouth rinse (aqueous extracts) on dental plaque and gingivitis in children.

Science.gov (United States)

Bhattacharjee, Ritesh; Nekkanti, Sridhar; Kumar, Nikesh G; Kapuria, Ketan; Acharya, Shashidhar; Pentapati, Kalyana C

2015-08-01

The aim of the present study was to evaluate the efficacy of triphala mouth rinse (aqueous) in the reduction of plaque and gingivitis among children. The study was a randomized, double-blinded, controlled trial, with a total of 60 school children (n = 30 in each group; triphala and chlorhexidine groups). Plaque and gingival indices were used to evaluate baseline and follow-up plaque and gingivitis. A total of 57 children completed the study. Both chlorhexidine and triphala groups showed significantly lower mean gingival and plaque index scores at follow up than baseline (P gingival index between the two groups (P = 0.826). The percentage change in the mean plaque index was significantly higher in the chlorhexidine group compared to the triphala group (P = 0.048). The effectiveness of triphala in the reduction of plaque and gingivitis was comparable to chlorhexidine, and can be used for short-term purposes without potential side-effects. It is a cost-effective alternative in reducing plaque and gingivitis. © 2014 Wiley Publishing Asia Pty Ltd.

Inhibition of dental plaque formation by toothpaste containing propolis

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Nurin Aisyiyah Listyasari

2012-12-01

Full Text Available Background: Plaque is the main cause of caries and periodontal disease. Caries and periodontal disease can be prevented by inhibiting dental plaque formation. To inhibit the formation of plaque, teeth must be brushed with toothpaste. According to previous studies, propolis contains apigenin and tt-farnesol classified as flavonoid that can inhibit the formation of dental plaque by inhibiting glucosyltransferase enzym and membrane integrity of Streptococcus mutans. Purpose: The aim of this study was to determine the effect of toothpaste containing propolis on the formation of dental plaque. Methods: Post test with only control group design was used. The subjects of this study were 30 boarding school students of Hidayatullah, Yayasan Al-Burhan, Gedawang, Semarang, divided into two groups, randomized control group and treatment group. Control group was not treated with toothpaste contanining propolis. Meanwhile, treatment group was treated with toothpaste containing propolis. Plaque then was measured by using plaque index of Sillness and Loe method after using toothpaste containing propolis for four hours. Afterwards, the data was analyzed by a computer program, Mann-Whitney test, with its significance p < 0.05. Results: The result of Mann-Whitney test showed a significant difference, 0.002 (p < 0.05, between the control group and the treatment group. The median of the control group was about 3.41, while that of the treatment group was about 0.58. Conclusion: The use of toothpaste contaning propolis can prevent dental plaque formation.Latar belakang: Plak merupakan penyebab utama terjadinya karies dan penyakit periodontal. Karies dan penyakit periodontal dapat dicegah dengan menghambat pembentukan plak gigi. Untuk mencegah terbentuknya plak, gigi harus digosok menggunakan pasta gigi. Penelitian terdahulu menyebutkan bahwa propolis mengandung flavonoid apigenin dan tt-farnesol yang mampu menghambat aktivitas enzim glukosiltransferase dan menghambat

High-risk plaque features can be detected in non-stenotic carotid plaques of patients with ischaemic stroke classified as cryptogenic using combined 18F-FDG PET/MR imaging

International Nuclear Information System (INIS)

Hyafil, Fabien; Schindler, Andreas; Obenhuber, Tilman; Saam, Tobias; Sepp, Dominik; Hoehn, Sabine; Poppert, Holger; Bayer-Karpinska, Anna; Boeckh-Behrens, Tobias; Hacker, Marcus; Nekolla, Stephan G.; Rominger, Axel; Dichgans, Martin; Schwaiger, Markus

2016-01-01

The aim of this study was to investigate in 18 patients with ischaemic stroke classified as cryptogenic and presenting non-stenotic carotid atherosclerotic plaques the morphological and biological aspects of these plaques with magnetic resonance imaging (MRI) and 18 F-fluoro-deoxyglucose positron emission tomography ( 18 F-FDG PET) imaging. Carotid arteries were imaged 150 min after injection of 18 F-FDG with a combined PET/MRI system. American Heart Association (AHA) lesion type and plaque composition were determined on consecutive MRI axial sections (n = 460) in both carotid arteries. 18 F-FDG uptake in carotid arteries was quantified using tissue to background ratio (TBR) on corresponding PET sections. The prevalence of complicated atherosclerotic plaques (AHA lesion type VI) detected with high-resolution MRI was significantly higher in the carotid artery ipsilateral to the ischaemic stroke as compared to the contralateral side (39 vs 0 %; p = 0.001). For all other AHA lesion types, no significant differences were found between ipsilateral and contralateral sides. In addition, atherosclerotic plaques classified as high-risk lesions with MRI (AHA lesion type VI) were associated with higher 18 F-FDG uptake in comparison with other AHA lesions (TBR = 3.43 ± 1.13 vs 2.41 ± 0.84, respectively; p < 0.001). Furthermore, patients presenting at least one complicated lesion (AHA lesion type VI) with MRI showed significantly higher 18 F-FDG uptake in both carotid arteries (ipsilateral and contralateral to the stroke) in comparison with carotid arteries of patients showing no complicated lesion with MRI (mean TBR = 3.18 ± 1.26 and 2.80 ± 0.94 vs 2.19 ± 0.57, respectively; p < 0.05) in favour of a diffuse inflammatory process along both carotid arteries associated with complicated plaques. Morphological and biological features of high-risk plaques can be detected with 18 F-FDG PET/MRI in non-stenotic atherosclerotic plaques ipsilateral to the stroke, suggesting a causal

Evidence of helicobacter pylori infection in dental plaque and gastric mucosa

International Nuclear Information System (INIS)

Siddiq, M.; Haseeb-ur-Rehman; Mahmood, A.

2004-01-01

Objective: To determine the presence of Helicobacter pylori (H. pylori) in dental plaque of individuals suffering from H. pylori associated gastric disease. Patients and Methods: Patients presenting with symptoms/signs of chronic gastritis were included in the study. Specimens of dental plaque and gastric biopsy were collected from all the patients. The dental plaque specimen was processed for helicourease test and the gastric biopsy specimens were processed both for the helicourease test and histopathology. Results: Out of all patients studied (n=52), 32 (61.53%) were positive for helicourease test with gastric biopsy while 48 (92.30%) were positive with dental plaque. The histopathology of gastric biopsy showed H. pylori associated chronic active gastritis in 42 (80.76%) patients. Eight (15.38%) patients showed chronic active gastritis which was not associated with H. pylori while in 2 (3.84%) patients the gastric biopsy specimen was unremarkable. Conclusion: Majority of the patients have possible H. pylori colonization in dental plaque while about two-thirds have H. pylori associated chronic active gastritis. Oral cavity may be the first place for colonization and then the infection involves the gastric mucosa. (author)

High-risk carotid plaques identified by CT-angiogram can predict acute myocardial infarction.

Science.gov (United States)

Mosleh, Wassim; Adib, Keenan; Natdanai, Punnanithinont; Carmona-Rubio, Andres; Karki, Roshan; Paily, Jacienta; Ahmed, Mohamed Abdel-Aal; Vakkalanka, Sujit; Madam, Narasa; Gudleski, Gregory D; Chung, Charles; Sharma, Umesh C

2017-04-01

Prior studies identified the incremental value of non-invasive imaging by CT-angiogram (CTA) to detect high-risk coronary atherosclerotic plaques. Due to their superficial locations, larger calibers and motion-free imaging, the carotid arteries provide the best anatomic access for the non-invasive characterization of atherosclerotic plaques. We aim to assess the ability of predicting obstructive coronary artery disease (CAD) or acute myocardial infarction (MI) based on high-risk carotid plaque features identified by CTA. We retrospectively examined carotid CTAs of 492 patients that presented with acute stroke to characterize the atherosclerotic plaques of the carotid arteries and examined development of acute MI and obstructive CAD within 12-months. Carotid lesions were defined in terms of calcifications (large or speckled), presence of low-attenuation plaques, positive remodeling, and presence of napkin ring sign. Adjusted relative risks were calculated for each plaque features. Patients with speckled (<3 mm) calcifications and/or larger calcifications on CTA had a higher risk of developing an MI and/or obstructive CAD within 1 year compared to patients without (adjusted RR of 7.51, 95%CI 1.26-73.42, P = 0.001). Patients with low-attenuation plaques on CTA had a higher risk of developing an MI and/or obstructive CAD within 1 year than patients without (adjusted RR of 2.73, 95%CI 1.19-8.50, P = 0.021). Presence of carotid calcifications and low-attenuation plaques also portended higher sensitivity (100 and 79.17%, respectively) for the development of acute MI. Presence of carotid calcifications and low-attenuation plaques can predict the risk of developing acute MI and/or obstructive CAD within 12-months. Given their high sensitivity, their absence can reliably exclude 12-month events.

Mechanical Stresses in Carotid Plaques

DEFF Research Database (Denmark)

Samuel, Samuel Alberg

simulationer, som tillod beregning af longitudinelle stress-niveauer i den fibrøse kappe. Afhandlingen indeholder tre artikler, som beskriver denne metode. Den første; “Mechanical Stresses in Carotid Plaques using MRI-Based Fluid Structure Interaction Models”, beskriver i detaljer metoden til at danne de...

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

Science.gov (United States)

2011-10-26

... Information Request on Phototherapy for Treatment of Chronic Plaque Psoriasis AGENCY: Agency for Healthcare... manufacturers of Phototherapy medical devices for treatment of chronic plaque psoriasis. Scientific information... Systemic Agents and Phototherapy for Treatment of Chronic Plaque Psoriasis, which is currently being...

Magnetic resonance imaging of vulnerable atherosclerotic plaques: current imaging strategies and molecular imaging probes

NARCIS (Netherlands)

Briley-Saebo, Karen C.; Mulder, Willem J. M.; Mani, Venkatesh; Hyafil, Fabien; Amirbekian, Vardan; Aguinaldo, Juan Gilberto S.; Fisher, Edward A.; Fayad, Zahi A.

2007-01-01

The vulnerability or destabilization of atherosclerotic plaques has been directly linked to plaque composition. Imaging modalities, such as magnetic resonance (MR) imaging, that allow for evaluation of plaque composition at a cellular and molecular level, could further improve the detection of

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

Science.gov (United States)

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

2014-01-01

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

Multimodal nonlinear imaging of atherosclerotic plaques differentiation of triglyceride and cholesterol deposits

Directory of Open Access Journals (Sweden)

Christian Matthäus

2014-09-01

Full Text Available Cardiovascular diseases in general and atherothrombosis as the most common of its individual disease entities is the leading cause of death in the developed countries. Therefore, visualization and characterization of inner arterial plaque composition is of vital diagnostic interest, especially for the early recognition of vulnerable plaques. Established clinical techniques provide valuable morphological information but cannot deliver information about the chemical composition of individual plaques. Therefore, spectroscopic imaging techniques have recently drawn considerable attention. Based on the spectroscopic properties of the individual plaque components, as for instance different types of lipids, the composition of atherosclerotic plaques can be analyzed qualitatively as well as quantitatively. Here, we compare the feasibility of multimodal nonlinear imaging combining two-photon fluorescence (TPF, coherent anti-Stokes Raman scattering (CARS and second-harmonic generation (SHG microscopy to contrast composition and morphology of lipid deposits against the surrounding matrix of connective tissue with diffraction limited spatial resolution. In this contribution, the spatial distribution of major constituents of the arterial wall and atherosclerotic plaques like elastin, collagen, triglycerides and cholesterol can be simultaneously visualized by a combination of nonlinear imaging methods, providing a powerful label-free complement to standard histopathological methods with great potential for in vivo application.

Linkages between oral commensal bacteria and atherosclerotic plaques in coronary artery disease patients.

Science.gov (United States)

Chhibber-Goel, Jyoti; Singhal, Varsha; Bhowmik, Debaleena; Vivek, Rahul; Parakh, Neeraj; Bhargava, Balram; Sharma, Amit

2016-01-01

Coronary artery disease is an inflammatory disorder characterized by narrowing of coronary arteries due to atherosclerotic plaque formation. To date, the accumulated epidemiological evidence supports an association between oral bacterial diseases and coronary artery disease, but has failed to prove a causal link between the two. Due to the recent surge in microbial identification and analyses techniques, a number of bacteria have been independently found in atherosclerotic plaque samples from coronary artery disease patients. In this study, we present meta-analysis from published studies that have independently investigated the presence of bacteria within atherosclerotic plaque samples in coronary artery disease patients. Data were collated from 63 studies covering 1791 patients spread over a decade. Our analysis confirms the presence of 23 oral commensal bacteria, either individually or in co-existence, within atherosclerotic plaques in patients undergoing carotid endarterectomy, catheter-based atherectomy, or similar procedures. Of these 23 bacteria, 5 ( Campylobacter rectus , Porphyromonas gingivalis , Porphyromonas endodontalis , Prevotella intermedia , Prevotella nigrescens ) are unique to coronary plaques, while the other 18 are additionally present in non-cardiac organs, and associate with over 30 non-cardiac disorders. We have cataloged the wide spectrum of proteins secreted by above atherosclerotic plaque-associated bacteria, and discuss their possible roles during microbial migration via the bloodstream. We also highlight the prevalence of specific poly-microbial communities within atherosclerotic plaques. This work provides a resource whose immediate implication is the necessity to systematically catalog landscapes of atherosclerotic plaque-associated oral commensal bacteria in human patient populations.

Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients

OpenAIRE

Otten, Marieke P. T.; Busscher, Henk J.; Abbas, Frank; van der Mei, Henny C.; van Hoogmoed, Chris G.

2012-01-01

Objectives Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims. Materials and methods First, volunteers brushed 2 weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12 h af...

Microglia in diffuse plaques in hereditary cerebral hemorrhage with amyloidosis (Dutch). An immunohistochemical study

NARCIS (Netherlands)

Maat-Schieman, M. L.; Rozemuller, A. J.; van Duinen, S. G.; Haan, J.; Eikelenboom, P.; Roos, R. A.

1994-01-01

In hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D) beta/A4 amyloid deposition is found in meningocortical blood vessels and in diffuse plaques in the cerebral cortex. Diffuse plaques putatively represent early stages in the formation of senile plaques. Microglia are intimately

Use of the Toric Surgical Marker to Aid in Intraoperative Plaque Placement for the USC Eye Physics Plaques to Treat Uveal Melanoma: A New Surgical Technique.

Science.gov (United States)

Berry, Jesse L; Kim, Jonathan W; Jennelle, Richard; Astrahan, Melvin

2015-09-01

To describe a new surgical technique for intraoperative placement of Eye Physics (EP) plaques for uveal melanoma using a toric marker. A toric marker is designed for cataract surgery to align the axis of astigmatism; its use was modified in this protocol to mark the axis of suture coordinates as calculated by Plaque Simulator (PS) software. The toric marker can be used to localize suture coordinates, in degrees, during intraoperative plaque placement. Linear marking using the toric marker decreases potential inaccuracies associated with the surgeon estimating 'clock-hours' by dot placement. Use of the toric marker aided surgical placement of EP plaques. The EP planning protocol is now designed to display the suture coordinates either by clock-hours or degrees, per surgeon preference. Future research is necessary to determine whether routine use of the toric marker improves operative efficiency. [Ophthalmic Surg Lasers Imaging Retina. 2015;46:866-870.]. Copyright 2015, SLACK Incorporated.

Effect of kibble size, shape and additives on plaque in cats

NARCIS (Netherlands)

Clarke, D.E.; Servet, E.; Hendriks, W.H.; Thomas, D.G.; Weidgraaf, K.; Biourge, V.C.

2010-01-01

Forty mixed-breed cats completed a parallel-group, clinical study to compare supragingival plaque accumulation using a triangular or rectangular shaped dry-expanded diet, with or without an anti-calculus agent (sodium tripolyphosphate) or an anti-plaque agent (plaquereducing nutrient). The cats were

Topical tazarotene vs. coal tar in stable plaque psoriasis

Energy Technology Data Exchange (ETDEWEB)

Kumar, U.; Kaur, I.; Dogra, S.; De, D.; Kumar, B. [Postgraduate Institute of Medical Education & Research, Chandigarh (India)

2010-07-15

The efficacy of topical tazarotene has not previously been compared with the conventional topical treatment of crude coal tar (CCT) in stable plaque psoriasis. In this nonblinded side-to-side comparison study, patients with chronic stable plaque psoriasis, who had bilaterally symmetrical plaques on the limbs, applied 0.1% tazarotene gel on the right side and 5% CCT ointment on the left side once daily for 12 weeks followed by an 8-week treatment-free follow up period. Severity of psoriatic lesions and response to treatment was evaluated by scoring erythema, scaling and induration (ESI). Of 30 patients recruited, 27 could be assessed. In the per-protocol analysis, the mean percentage reduction in ESI score at the end of the treatment period was 74.15% {+-} 9.43 and 77.37% {+-} 10.93 with tazarotene and CCT, respectively (P {gt} 0.05). A reduction in ESI score of {gt} 75% was seen in 11 (40.74%) and 16 (59.26%) patients with tazarotene and CCT, respectively, at the end of 12 weeks. Side-effects were seen in 48.14% of patients treated with tazarotene, but in no patient treated with CCT. Tazarotene 0.1% gel has comparable clinical efficacy to CCT 5% ointment. CCT ointment remains a cost-effective therapy for plaque psoriasis.

Microbial profiling of dental plaque from mechanically ventilated patients.

Science.gov (United States)

Sands, Kirsty M; Twigg, Joshua A; Lewis, Michael A O; Wise, Matt P; Marchesi, Julian R; Smith, Ann; Wilson, Melanie J; Williams, David W

2016-02-01

Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97% gene similarity cut-off for bacterial species level identifications. A significant 'microbial shift' occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection.

Radiation regression patterns after cobalt plaque insertion for retinoblastoma

International Nuclear Information System (INIS)

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

1983-01-01

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)

Radiation regression patterns after cobalt plaque insertion for retinoblastoma

Energy Technology Data Exchange (ETDEWEB)

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

1983-08-01

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).

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

Energy Technology Data Exchange (ETDEWEB)

Dhenain, M. [URA CEA CNRS 2210, I2BM, SHFJ, 4 Place du General Leclerc, 91401 Orsay Cedex (France); Dhenain, M.; El Tannir El Tayara, N.; Wu, T.D.; Volk, A.; Quintana, C. [U759 INSERM, Centre Universitaire, Laboratoire 112, 91405 Orsay Cedex (France); Dhenain, M.; El Tannir El Tayara, N.; Wu, T.D.; Volk, A.; Quintana, C. [Institut Curie, Centre Universitaire, Laboratoire 112, 91405 Orsay Cedex (France); Guegan, M.; Delatour, B. [Instituto de Microelectronica de Madrid-CSIC, 8, Isaac Newton, 28760 Tres Cantos, Madrid (Spain)

2009-07-01

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 were detected in all mice but with different frequency and magnitude. Hence, the prevalence and size of the lesions were higher in APP/PS1 mice. However, even in APP/PS1 mice, thalamic spots did not occur in all the old animals. In APP/PS1 mice, spots detection was related to high iron and calcium load within amyloid plaques and thus reflects the ability of such plaque to capture large amounts of minerals. Interestingly, calcium and iron was also detected in extra-thalamic plaques but with a lower intensity. Hypointense lesions in the thalamus were not associated with the iron load in the tissue surrounding the plaques, nor with micro-hemorrhages, inflammation, or a neuro-degenerative context. (authors)

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

Science.gov (United States)

1971-01-01

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

Adaptive Binary Arithmetic Coder-Based Image Feature and Segmentation in the Compressed Domain

Directory of Open Access Journals (Sweden)

Hsi-Chin Hsin

2012-01-01

Full Text Available Image compression is necessary in various applications, especially for efficient transmission over a band-limited channel. It is thus desirable to be able to segment an image in the compressed domain directly such that the burden of decompressing computation can be avoided. Motivated by the adaptive binary arithmetic coder (MQ coder of JPEG2000, we propose an efficient scheme to segment the feature vectors that are extracted from the code stream of an image. We modify the Compression-based Texture Merging (CTM algorithm to alleviate the influence of overmerging problem by making use of the rate distortion information. Experimental results show that the MQ coder-based image segmentation is preferable in terms of the boundary displacement error (BDE measure. It has the advantage of saving computational cost as the segmentation results even at low rates of bits per pixel (bpp are satisfactory.

Preliminary Study of In Vivo Formed Dental Plaque Using Confocal Microscopy and Scanning Electron Microscopy

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KA. Al-Salihi

2009-12-01

Full Text Available Objective: Confocal laser scanning microscopy (CLSM is relatively a new light microscopical imaging technique with a wide range of applications in biological sciences. The primary value of CLSM for the biologist is its ability to provide optical sections from athree-dimensional specimen. The present study was designed to assess the thickness and content of in vivo accumulated dental plaque using CLSM and scanning electron microscopy (SEM.Materials and Methods: Acroflat lower arch splints (acrylic appliance were worn by five participants for three days without any disturbance. The formed plaques were assessed using CLSM combined with vital fluorescence technique and SEM.Results: In this study accumulated dental plaque revealed varied plaque microflora vitality and thickness according to participant’s oral hygiene. The thickness of plaque smears ranged from 40.32 to 140.72 μm and 65.00 to 128.88 μm for live (vital and dead accumulated microorganisms, respectively. Meanwhile, the thickness of plaque on the appliance ranged from 101 μm to 653 μm. CLSM revealed both dead and vital bacteria on the surface of the dental plaque. In addition, SEM revealed layers of various bacterial aggregations in all dental plaques.Conclusion: This study offers a potent non-invasive tool to evaluate and assess the dental plaque biofilm, which is a very important factor in the development of dental caries.

Control study of MRI and histopathology in early atherosclerotic plaque of rabbits

International Nuclear Information System (INIS)

Song Qiong; Xia Liming; Wang Chengyuan; Hu Junwu; Feng Dingyi; Zou Mingli

2006-01-01

Objective: To explore the diagnostic value of MRI in the early atherosclerosis. Materials and Methods: Atherosclerosis was induced in 20 New Zealand White male rabbits with high cholesterol diet. Rabbits underwent serial MRI at 9 and 18 weeks after high cholesterol diet. Axial T 1 and fat-suppressed PDWI spin echo images of the abdominal aorta were obtained above and below the right renal arteries. The signal intensity and morphologic features of plaque in the various phases after high cholesterol diet in MRI were analyzed and compared with those of histopathology. Results: Plaque could be observed in all animals on MRI at 9 weeks after high cholesterol diet, and mild enhancement of the plaque could be noted on enhanced imaging. Imaging effect was the best at T 1 sequence. Plaque size increased gradually at 18 weeks. Plaque and vessel wall were all enrichment. In histopathology, foam cells, collagen and matrix fiber component can be seen in the various phases. Conclusion: The conventional MRI technique can be used to assess the formation and development of the early atherosclerosis dynamically and histologically. (authors)

High-risk plaque features can be detected in non-stenotic carotid plaques of patients with ischaemic stroke classified as cryptogenic using combined {sup 18}F-FDG PET/MR imaging

Energy Technology Data Exchange (ETDEWEB)

Hyafil, Fabien [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Bichat University Hospital, Department of Nuclear Medicine, Paris (France); Schindler, Andreas; Obenhuber, Tilman; Saam, Tobias [Ludwig Maximilians University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Sepp, Dominik; Hoehn, Sabine; Poppert, Holger [Technische Universitaet Muenchen, Department of Neurology, Klinikum rechts der Isar, Munich (Germany); Bayer-Karpinska, Anna [Ludwig Maximilians University Hospital Munich, Institute for Stroke and Dementia Research, Munich (Germany); Boeckh-Behrens, Tobias [Technische Universitaet Muenchen, Department of Neuroradiology, Klinikum Rechts der Isar, Munich (Germany); Hacker, Marcus [Medical University of Vienna, Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Nekolla, Stephan G. [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Partner Site Munich Heart Alliance, German Centre for Cardiovascular Research (DZHK), Munich (Germany); Rominger, Axel [Ludwig Maximilians University Hospital Munich, Department of Nuclear Medicine, Munich (Germany); Dichgans, Martin [Technische Universitaet Muenchen, Department of Neurology, Klinikum rechts der Isar, Munich (Germany); Munich Cluster of Systems Neurology (SyNergy), Munich (Germany); Schwaiger, Markus [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany)

2016-02-15

The aim of this study was to investigate in 18 patients with ischaemic stroke classified as cryptogenic and presenting non-stenotic carotid atherosclerotic plaques the morphological and biological aspects of these plaques with magnetic resonance imaging (MRI) and {sup 18}F-fluoro-deoxyglucose positron emission tomography ({sup 18}F-FDG PET) imaging. Carotid arteries were imaged 150 min after injection of {sup 18}F-FDG with a combined PET/MRI system. American Heart Association (AHA) lesion type and plaque composition were determined on consecutive MRI axial sections (n = 460) in both carotid arteries. {sup 18}F-FDG uptake in carotid arteries was quantified using tissue to background ratio (TBR) on corresponding PET sections. The prevalence of complicated atherosclerotic plaques (AHA lesion type VI) detected with high-resolution MRI was significantly higher in the carotid artery ipsilateral to the ischaemic stroke as compared to the contralateral side (39 vs 0 %; p = 0.001). For all other AHA lesion types, no significant differences were found between ipsilateral and contralateral sides. In addition, atherosclerotic plaques classified as high-risk lesions with MRI (AHA lesion type VI) were associated with higher {sup 18}F-FDG uptake in comparison with other AHA lesions (TBR = 3.43 ± 1.13 vs 2.41 ± 0.84, respectively; p < 0.001). Furthermore, patients presenting at least one complicated lesion (AHA lesion type VI) with MRI showed significantly higher {sup 18}F-FDG uptake in both carotid arteries (ipsilateral and contralateral to the stroke) in comparison with carotid arteries of patients showing no complicated lesion with MRI (mean TBR = 3.18 ± 1.26 and 2.80 ± 0.94 vs 2.19 ± 0.57, respectively; p < 0.05) in favour of a diffuse inflammatory process along both carotid arteries associated with complicated plaques. Morphological and biological features of high-risk plaques can be detected with {sup 18}F-FDG PET/MRI in non-stenotic atherosclerotic plaques ipsilateral

Low copper and high manganese levels in prion protein plaques

Science.gov (United States)

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

2013-01-01

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

40 CFR 305.33 - Burden of presentation; burden of persuasion.

Science.gov (United States)

2010-07-01

... persuasion. 305.33 Section 305.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Hearing Procedure § 305.33 Burden of presentation; burden of persuasion. The Requestor has the burden of... justified. Accordingly, the Requestor bears the burdens of presentation and persuasion. Following the...

Carotid Artery Stenting Successfully Prevents Progressive Stroke Due to Mobile Plaque

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Masahiro Oomura

2015-05-01

Full Text Available We report a case of progressive ischemic stroke due to a mobile plaque, in which carotid artery stenting successfully prevented further infarctions. A 78-year-old man developed acute multiple infarcts in the right hemisphere, and a duplex ultrasound showed a mobile plaque involving the bifurcation of the left common carotid artery. Maximal medical therapy failed to prevent further infarcts, and the number of infarcts increased with his neurological deterioration. Our present case suggests that the deployment of a closed-cell stent is effective to prevent the progression of the ischemic stroke due to the mobile plaque.

Cetylpyridinium chloride mouth rinses alleviate experimental gingivitis by inhibiting dental plaque maturation.

Science.gov (United States)

Teng, Fei; He, Tao; Huang, Shi; Bo, Cun-Pei; Li, Zhen; Chang, Jin-Lan; Liu, Ji-Quan; Charbonneau, Duane; Xu, Jian; Li, Rui; Ling, Jun-Qi

2016-09-29

Oral rinses containing chemotherapeutic agents, such as cetylpyridinium chloride (CPC), can alleviate plaque-induced gingival infections, but how oral microbiota respond to these treatments in human population remains poorly understood. Via a double-blinded, randomised controlled trial of 91 subjects, the impact of CPC-containing oral rinses on supragingival plaque was investigated in experimental gingivitis, where the subjects, after a 21-day period of dental prophylaxis to achieve healthy gingivae, received either CPC rinses or water for 21 days. Within-subject temporal dynamics of plaque microbiota and symptoms of gingivitis were profiled via 16S ribosomal DNA gene pyrosequencing and assessment with the Mazza gingival index. Cetylpyridinium chloride conferred gingival benefits, as progression of gingival inflammation resulting from a lack of dental hygiene was significantly slower in the mouth rinse group than in the water group due to inhibition of 17 gingivitis-enriched bacterial genera. Tracking of plaque α and β diversity revealed that CPC treatment prevents acquisition of new taxa that would otherwise accumulate but maintains the original biodiversity of healthy plaques. Furthermore, CPC rinses reduced the size, local connectivity and microbiota-wide connectivity of the bacterial correlation network, particularly for nodes representing gingivitis-enriched taxa. The findings of this study provide mechanistic insights into the impact of oral rinses on the progression and maturation of dental plaque in the natural human population.

The influence of xylitol containing toothpaste on plaque formation inhibition on fixed bridge

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Hamim Fithrony

2009-09-01

Full Text Available Background: Plaque is the main cause of teeth and periodontal tissue damage, which usually accumulates on crown surfaces. To avoid this, plaque control is the best way that not only has a close connection to oral hygiene but also become important element in dental practice. Previously, xylitol was used as alternative sweetener for diabetic patients, but later it is used to maintain healthy teeth. Xylitol is capable to inhibit Streptococcus mutans growth which changes sugar and other carbohydrate into acid, because xylitol cannot be fermented. Purpose: This study was aimed to understand the inhibition capability of toothpaste containing xylitol to plaque formation on fixed bridge. Methods: This clinical experiment study was carried out in fifteen patients wearing fixed bridge at Prosthodontics Department, Faculty of Dentistry, Airlangga University in Surabaya from 2005 to 2008. Samples were based on selective random sampling technique. Plaque index was analyzed by Mann Whitney test. Result: This study showed that there was significant difference of plaque scores in patients who brush their teeth using xylitol containing toothpaste compared to the control group (placebo. Conclusion: Xylitol was capable to inhibit plaque formation on fixed bridge.

Impact of previous vascular burden on in-hospital and long-term mortality in patients with ST-segment elevation myocardial infarction.

Science.gov (United States)

Consuegra-Sánchez, Luciano; Melgarejo-Moreno, Antonio; Galcerá-Tomás, José; Alonso-Fernández, Nuria; Díaz-Pastor, Angela; Escudero-García, Germán; Jaulent-Huertas, Leticia; Vicente-Gilabert, Marta

2014-06-01

Patients with a current acute coronary syndrome and previous ischemic heart disease, peripheral arterial disease, and/or cerebrovascular disease are reported to have a poorer outcome than those without these previous conditions. It is uncertain whether this association with outcome is observed at long-term follow-up. Prospective observational study, including 4247 patients with ST-segment elevation myocardial infarction. Detailed clinical data and information on previous ischemic heart disease, peripheral arterial disease, and cerebrovascular disease ("vascular burden") were recorded. Multivariate models were performed for in-hospital and long-term (median, 7.2 years) all-cause mortality. One vascular territory was affected in 1131 (26.6%) patients and ≥ 2 territories in 221 (5.2%). The total in-hospital mortality rate was 12.3% and the long-term incidence density was 3.5 deaths per 100 patient-years. A background of previous ischemic heart disease (odds ratio = 0.83; P = .35), peripheral arterial disease (odds ratio = 1.30; P = .34), or cerebrovascular disease (stroke) (odds ratio = 1.15; P = .59) was not independently predictive of in-hospital death. In an adjusted model, previous cerebrovascular disease and previous peripheral arterial disease were both predictors of mortality at long-term follow-up (hazard ratio = 1.57; P cerebrovascular disease and peripheral arterial disease were predictors of mortality at long-term after hospital discharge. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

No Calcium-Fluoride-Like Deposits Detected in Plaque Shortly after a Sodium Fluoride Mouthrinse

OpenAIRE

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

2010-01-01

Plaque ‘calcium-fluoride-like’ (CaF2-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 μg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2...

Investigation Of Interaction Between Nitinol Stent And A Vascular Plaque Using Finite Element Method

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Recep Güneş

2012-06-01

Full Text Available In this study, the interaction between the Nitinol stent and the artery with plaque was investigated using finite element method. The occurring pressure values during the cardiac contraction (systolic and loosening (diastolic were applied as loading to the modeled system with Nitinol stent. In the light of the stress values, the suitability of the Nitinol stent in an artery with plaque was investigated. In the analysis, Nitinol stent was assumed to be shape memory alloy, and artery and plaque were assumed to behave linearly elastic. As a result, the stress and deformations in the plaque and artery due to the interference of Nitinol stent were discussed and concluded that the structure of artery with plaque can be expanded in accordance with Nitinol stent.

Oculocutaneous albinism complicated with an ulcerated plaque

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Lokanatha Keshavalu

2013-04-01

Full Text Available A 32-year-old male with a history of albinism and farmer by occupation presented with an ulcerated plaque on the right wrist. The patient had light eyes, hair, and skin. Physical examination showed extensive photodamage. A skin biopsy specimen from the plaque revealed a well-differentiated squamous-cell carcinoma. Wide surgical excision was done. The most common types of oculocutaneous albinism (OCA, OCA 1 and OCA 2, are autosomal recessive disorders of pigmentation that commonly affect the skin, hair and eyes. Photodamage and skin cancers plague patients with albinism. Albinos face a myriad of social and medical issues. Importance of photoprotection, skin cancer surveillance and treatment has been stressed upon in this report.

45 CFR 672.17 - Burden of presentation; burden of persuasion.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Burden of presentation; burden of persuasion. 672.17 Section 672.17 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT AND HEARING PROCEDURES § 672.17 Burden of presentation; burden of persuasion. The...

Chair-side detection of Prevotella Intermedia in mature dental plaque by its fluorescence.

Science.gov (United States)

Nomura, Yoshiaki; Takeuchi, Hiroaki; Okamoto, Masaaki; Sogabe, Kaoru; Okada, Ayako; Hanada, Nobuhiro

2017-06-01

Prevotella intermedia/nigrescens is one of the well-known pathogens causing periodontal diseases, and the red florescence excited by the visible blue light caused by the protoporphyrin IX in the bacterial cells could be useful for the chair-side detection. The aim of this study was to evaluated levels of periodontal pathogen, especially P. intermedia in clinical samples of red fluorescent dental plaque. Thirty two supra gingival plaque samples from six individuals were measured its fluorescence at 640nm wavelength excited by 409nm. Periodontopathic bacteria were counted by the Invader PLUS PCR assay. Co-relations the fluorescence intensity and bacterial counts were analyzed by Person's correlation coefficient and simple and multiple regression analysis. Positive and negative predictive values of the fluorescence intensities for with or without P. intermedia in supragingival plaque was calculated. When relative fluorescence unit (RFU) were logarithmic transformed, statistically significant linear relations between RFU and bacterial counts were obtained for P. intermedia, Porphyromonas gingivalis and Tannerella forsythia. By the multiple regression analysis, only P. intermedia had statistically significant co-relation with fluorescence intensities. All of the fluorescent dental plaque contained P. intermedia m. In contrast, 28% of non-fluorescent plaques contained P. intermedia. To check the fluorescence dental plaque in the oral cavity could be the simple chair-side screening of the mature dental plaque before examining the periodontal pathogens especially P. intermedia by the PCR method. Copyright © 2017 Elsevier B.V. All rights reserved.

Developing population segments with different levels of complexity and primary health care needs: An analysis using health administrative data in British Columbia, Canada

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Julia Langton

2017-04-01

We developed population segments designed to account for patient complexity and primary health care needs; as such, segments provide more information than traditional indices of morbidity burden based on counts of chronic conditions. These segments will be used to report information on the quality of primary care. We plan to include conduct validation studies using additional variables (e.g, socio-economic factors, level of vulnerability from patient surveys so that segments more accurately represent the level of complexity and patients’ primary health care needs.

Modest effect on plaque progression and vasodilatory function in atherosclerosis-prone mice exposed to nanosized TiO2

DEFF Research Database (Denmark)

Mikkelsen, Lone; Sheykhzade, Majid; Jensen, Keld A

2011-01-01

of atherosclerotic plaques in aorta was assessed in mice exposed to nanosized TiO2 (0.5 mg/kg bodyweight) once a week for 4 weeks. We measured mRNA levels of Mcp-1, Mip-2, Vcam-1, Icam-1 and Vegf in lung tissue to assess pulmonary inflammation and vascular function. TiO2-induced alterations in nitric oxide (NO...... were intratracheally instilled (0.5 mg/kg bodyweight) with rutile fine TiO2 (fTiO2, 288 nm), photocatalytic 92/8 anatase/rutile TiO2 (pTiO2, 12 nm), or rutile nano TiO2 (nTiO2, 21.6 nm) at 26 and 2 hours before measurement of vasodilatory function in aorta segments mounted in myographs. The progression...

[Influence of the fluoride releasing dental materials on the bacterial flora of dental plaque].

Science.gov (United States)

Płuciennik, Małgorzata; Sakowska, Danuta; Krzemiński, Zbigniew; Piatowska, Danuta

2008-01-01

The assessment of influence of silver-free, fluor releasing dental materials on dental plaque bacteria quantity. 17 patients were included into the study. 51 restorations were placed following manufacturers recommendations. Following materials were used: conventional glassionomer Ketac-Molar ESPE, resin modified glassionomer Fuji II LC GC and fluor containing composite Charisma Heraeus Kulzer Class V restorations were placed in following teeth of upper and lower jaw: canines, first bicuspids, second bicuspids. Sound enamel was a control. After 10 weeks the 72 hours old dental plaque was collected from surface of restorations and control using sterile probe. Total amount of 68 dental plaques were investigated. Each plaque was placed on scaled and sterile aluminum foil. The moist weight of dental plaque was scaled. Dental plaque was moved into 7 ml 0.85% NaCl solution reduced by cystein chlorine hydrogen and disintegrated by ultrasounds (power:100 Watt, wave amplitude: 5 micorm). The suspension of dental plaque was serially diluted from 10(-4) to 10(-5) in sterile 0,85% NaCl solution, and seeded with amount of 0.1 ml on appropriate base. In dental plaque trials the amount of cariogenic bacteria was calculated--Streptococcus mutans, Streptococcus, Lactobacillus, Veillonella and Neisseria, and also total amount of aerobic and anaerobic bacteria was measured. Microbiologic studies were performed in Institute of Microbiology, Medical University, Łódź. Statistical analysis of collected data was accomplished. In 72 hours old dental plaques collected from the surfaces of Ketac -Molar, Fuji II LC, Charisma after 10 weeks since being placed into the class V cavity, results show no statistically significant differences in the amount of Streptococcus mutans, Streptococcus spp., Lactobacillus spp., Veillonella spp., Neisseria spp, in total amount of aerobic and anaerobic bacteria and in the quantity proportion of Streptococcus mutans versus Streptococcus spp. in comparison

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

Science.gov (United States)

Trombelli, L; Farina, R

2013-06-01

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

Multiple Vehicle Detection and Segmentation in Malaysia Traffic Flow

Science.gov (United States)

Fariz Hasan, Ahmad; Fikri Che Husin, Mohd; Affendi Rosli, Khairul; Norhafiz Hashim, Mohd; Faiz Zainal Abidin, Amar

2018-03-01

Vision based system are widely used in the field of Intelligent Transportation System (ITS) to extract a large amount of information to analyze traffic scenes. By rapid number of vehicles on the road as well as significant increase on cameras dictated the need for traffic surveillance systems. This system can take over the burden some task was performed by human operator in traffic monitoring centre. The main technique proposed by this paper is concentrated on developing a multiple vehicle detection and segmentation focusing on monitoring through Closed Circuit Television (CCTV) video. The system is able to automatically segment vehicle extracted from heavy traffic scene by optical flow estimation alongside with blob analysis technique in order to detect the moving vehicle. Prior to segmentation, blob analysis technique will compute the area of interest region corresponding to moving vehicle which will be used to create bounding box on that particular vehicle. Experimental validation on the proposed system was performed and the algorithm is demonstrated on various set of traffic scene.

Common carotid artery intima-media thickness is as good as carotid intima-media thickness of all carotid artery segments in improving prediction of coronary heart disease risk in the Atherosclerosis Risk in Communities (ARIC) study.

Science.gov (United States)

Nambi, Vijay; Chambless, Lloyd; He, Max; Folsom, Aaron R; Mosley, Tom; Boerwinkle, Eric; Ballantyne, Christie M

2012-01-01

Carotid intima-media thickness (CIMT) and plaque information can improve coronary heart disease (CHD) risk prediction when added to traditional risk factors (TRF). However, obtaining adequate images of all carotid artery segments (A-CIMT) may be difficult. Of A-CIMT, the common carotid artery intima-media thickness (CCA-IMT) is relatively more reliable and easier to measure. We evaluated whether CCA-IMT is comparable to A-CIMT when added to TRF and plaque information in improving CHD risk prediction in the Atherosclerosis Risk in Communities (ARIC) study. Ten-year CHD risk prediction models using TRF alone, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque were developed for the overall cohort, men, and women. The area under the receiver operator characteristic curve (AUC), per cent individuals reclassified, net reclassification index (NRI), and model calibration by the Grønnesby-Borgan test were estimated. There were 1722 incident CHD events in 12 576 individuals over a mean follow-up of 15.2 years. The AUC for TRF only, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque models were 0.741, 0.754, and 0.753, respectively. Although there was some discordance when the CCA-IMT + plaque- and A-CIMT + plaque-based risk estimation was compared, the NRI and clinical NRI (NRI in the intermediate-risk group) when comparing the CIMT models with TRF-only model, per cent reclassified, and test for model calibration were not significantly different. Coronary heart disease risk prediction can be improved by adding A-CIMT + plaque or CCA-IMT + plaque information to TRF. Therefore, evaluating the carotid artery for plaque presence and measuring CCA-IMT, which is easier and more reliable than measuring A-CIMT, provide a good alternative to measuring A-CIMT for CHD risk prediction.

Dosimetric verification of a dedicated 3D treatment planning system for episcleral plaque therapy

International Nuclear Information System (INIS)

Knutsen, Stig; Hafslund, Rune; Monge, Odd R.; Valen, Harald; Muren, Ludvig Paul; Rekstad, Bernt Louni; Krohn, Joergen; Dahl, Olav

2001-01-01

Purpose: Episcleral plaque therapy (EPT) is applied in the management of some malignant ocular tumors. A customized configuration of typically 4 to 20 radioactive seeds is fixed in a gold plaque, and the plaque is sutured to the scleral surface corresponding to the basis of the intraocular tumor, allowing for a localized radiation dose delivery to the tumor. Minimum target doses as high as 100 Gy are directed at malignant tumor sites close to critical normal tissues (e.g., optic disc and macula). Precise dosimetry is therefore fundamental for judging both the risk for normal tissue toxicity and tumor dose prescription. This paper describes the dosimetric verification of a commercially available dedicated treatment planning system (TPS) for EPT when realistic multiple-seed configurations are applied. Materials and Methods: The TPS Bebig Plaque Simulator is used to plan EPT at our institution. Relative dose distributions in a water phantom, including central axis depth dose and off-axis dose profiles for three different plaques, the University of Southern California (USC) No. 9 and the Collaborative Ocular Melanoma Study (COMS) 12-mm and 20-mm plaques, were measured with a diode detector. Each plaque was arranged with realistic multiple 125 I seed configurations. The measured dose distributions were compared to the corresponding dose profiles calculated with the TPS. All measurements were corrected for the angular sensitivity variation of the diode. Results: Single-seed dose distributions measured with our dosimetry setup agreed with previously published data within 3%. For the three multiple-seed plaque configurations, the measured and calculated dose distributions were in good agreement. For the central axis depth doses, the agreement was within 4%, whereas deviations up to 11% were observed in single points far off-axis. Conclusions: The Bebig Plaque Simulator is a reliable TPS for calculating relative dose distributions around realistic multiple 125 I seed

Uptake of inflammatory cell marker [{sup 11}C]PK11195 into mouse atherosclerotic plaques

Energy Technology Data Exchange (ETDEWEB)

Laitinen, Iina; Marjamaeki, Paeivi; Naagren, Kjell; Roivainen, Anne; Knuuti, Juhani [University of Turku, Turku PET Centre, Turku (Finland); Laine, V.J.O. [Turku University Hospital, Department of Pathology, Turku (Finland); Wilson, Ian [GE Healthcare Biosciences, Medical Diagnostics, London (United Kingdom); Leppaenen, Pia; Ylae-Herttuala, Seppo [University of Kuopio, A.I. Virtanen Institute, Kuopio (Finland)

2009-01-15

The ligand [{sup 11}C]PK11195 binds with high affinity and selectivity to peripheral benzodiazepine receptor, expressed in high amounts in macrophages. In humans, [{sup 11}C]PK11195 has been used successfully for the in vivo imaging of inflammatory processes of brain tissue. The purpose of this study was to explore the feasibility of [{sup 11}C]PK11195 in imaging inflammation in the atherosclerotic plaques. The presence of PK11195 binding sites in the atherosclerotic plaques was verified by examining the in vitro binding of [{sup 3}H]PK11195 onto mouse aortic sections. Uptake of intravenously administered [{sup 11}C]PK11195 was studied ex vivo in excised tissue samples and aortic sections of a LDLR/ApoB48 atherosclerotic mice. Accumulation of the tracer was compared between the atherosclerotic plaques and non-atherosclerotic arterial sites by autoradiography and histological analyses. The [{sup 3}H]PK11195 was found to bind to both the atherosclerotic plaques and the healthy wall. The autoradiography analysis revealed that the uptake of [{sup 11}C]PK11195 to inflamed regions in plaques was more prominent (p = 0.011) than to non-inflamed plaque regions, but overall it was not higher than the uptake to the healthy vessel wall. Also, the accumulation of {sup 11}C radioactivity into the aorta of the atherosclerotic mice was not increased compared to the healthy control mice. Our results indicate that the uptake of [{sup 11}C]PK11195 is higher in inflamed atherosclerotic plaques containing a large number of inflammatory cells than in the non-inflamed plaques. However, the tracer uptake to other structures of the artery wall was also prominent and may limit the use of [{sup 11}C]PK11195 in clinical imaging of atherosclerotic plaques. (orig.)

Intravascular optical imaging of high-risk plaques in vivo by targeting macrophage mannose receptors

Science.gov (United States)

Kim, Ji Bak; Park, Kyeongsoon; Ryu, Jiheun; Lee, Jae Joong; Lee, Min Woo; Cho, Han Saem; Nam, Hyeong Soo; Park, Ok Kyu; Song, Joon Woo; Kim, Tae Shik; Oh, Dong Joo; Gweon, Daegab; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

2016-03-01

Macrophages mediate atheroma expansion and disruption, and denote high-risk arterial plaques. Therefore, they are substantially gaining importance as a diagnostic imaging target for the detection of rupture-prone plaques. Here, we developed an injectable near-infrared fluorescence (NIRF) probe by chemically conjugating thiolated glycol chitosan with cholesteryl chloroformate, NIRF dye (cyanine 5.5 or 7), and maleimide-polyethylene glycol-mannose as mannose receptor binding ligands to specifically target a subset of macrophages abundant in high-risk plaques. This probe showed high affinity to mannose receptors, low toxicity, and allowed the direct visualization of plaque macrophages in murine carotid atheroma. After the scale-up of the MMR-NIRF probe, the administration of the probe facilitated in vivo intravascular imaging of plaque inflammation in coronary-sized vessels of atheromatous rabbits using a custom-built dual-modal optical coherence tomography (OCT)-NIRF catheter-based imaging system. This novel imaging approach represents a potential imaging strategy enabling the identification of high-risk plaques in vivo and holds promise for future clinical implications.

Analysis of Complex Coronary Plaque in Multidetector Computed Tomography: Comparison with Conventional Coronary Angiography

International Nuclear Information System (INIS)

Kim, Dong Hyun; Bang, Duck Won; Cho, Yoon Haeng; Suk, Eun Ha

2011-01-01

To delineate complex plaque morphology in patients with stable angina using coronary computed tomographic angiography (CTA). 36 patients with complex plaques proven by conventional coronary angiography (CAG), who had taken CTA for evaluation of typical angina, were enrolled in this study. Intravascular ultrasonography (IVUS) was performed in 14 patients (16 lesions). We compared CTA with CAG for plaque features and analyzed vascular cutoff, intraluminal filling defect in a patent vessel, irregularity of plaque, and ulceration. Also, the density of plaque was evaluated on CTA. CAG and CTA showed complex morphology in 44 cases (100%) and 34 cases, (77%), respectively, with features including abrupt vessel cutoff (27 vs. 16%, κ=0.57), intraluminal filling defect (32 vs. 30%, κ=0.77), irregularity (75 vs. 52%, κ=0.52), and ulceration (16 vs. 11%, κ=0.60). CTA indicated that the complex lesions were hypodense (mean 66 ± 21 Houndsfield Units). CTA is a very accurate and useful non-invasive imaging modality for evaluating complex plaque in patients with typical angina.

Analysis of Complex Coronary Plaque in Multidetector Computed Tomography: Comparison with Conventional Coronary Angiography

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Hyun [Dept. of Radiology, Soonchunhyang University Hospital, Bucheon (Korea, Republic of); Bang, Duck Won; Cho, Yoon Haeng [Dept. of Internal Medicine, Soonchunhyang University Hospital, Bucheon (Korea, Republic of); Suk, Eun Ha [Dept. of Anesthyesiology and Pain Medicine, Asan Medical Center, Seoul (Korea, Republic of)

2011-04-15

To delineate complex plaque morphology in patients with stable angina using coronary computed tomographic angiography (CTA). 36 patients with complex plaques proven by conventional coronary angiography (CAG), who had taken CTA for evaluation of typical angina, were enrolled in this study. Intravascular ultrasonography (IVUS) was performed in 14 patients (16 lesions). We compared CTA with CAG for plaque features and analyzed vascular cutoff, intraluminal filling defect in a patent vessel, irregularity of plaque, and ulceration. Also, the density of plaque was evaluated on CTA. CAG and CTA showed complex morphology in 44 cases (100%) and 34 cases, (77%), respectively, with features including abrupt vessel cutoff (27 vs. 16%, {kappa}=0.57), intraluminal filling defect (32 vs. 30%, {kappa}=0.77), irregularity (75 vs. 52%, {kappa}=0.52), and ulceration (16 vs. 11%, {kappa}=0.60). CTA indicated that the complex lesions were hypodense (mean 66 {+-} 21 Houndsfield Units). CTA is a very accurate and useful non-invasive imaging modality for evaluating complex plaque in patients with typical angina.

Salivary antimicrobial proteins associate with age-related changes in streptococcal composition in dental plaque.

Science.gov (United States)

Malcolm, J; Sherriff, A; Lappin, D F; Ramage, G; Conway, D I; Macpherson, L M D; Culshaw, S

2014-12-01

Secretion of antimicrobial proteins (AMPs) and salivary antibodies can modify biofilm formation at host body surfaces. In adolescents, associations have been reported between dental caries and salivary AMPs. AMPs demonstrate direct antimicrobial effects at high concentrations, and at lower more physiological concentrations they mediate changes in host cell defenses, which may alter the local environment and indirectly shape local biofilm formation. The expression of salivary AMPs in preschool children, at an age when the oral bacteria are known to change, has not been investigated. We sought to investigate salivary AMP expression in the context of previously well-documented changes in the oral cavities of this age group including salivary immunoglobulin A (IgA), oral bacteria and dental caries. Dental plaque and saliva were collected from 57 children aged 12-24 months at baseline, of whom 23 children were followed-up at 3 years of age. At each time, saliva was assessed for LL37, human neutrophil peptides 1-3, calprotectin, lactoferrin, salivary IgA, total plaque bacteria and Streptococcus mutans. Over time, concentrations of AMPs, S. mutans and bacteria-specific salivary IgA increased. Caries experience was also recorded when children were 3 years old. Concentrations of AMPs were highest in the saliva of 3-year-old children with the greatest burden of S. mutans. These data suggest that salivary AMPs are variable over time and between individuals, and are linked with bacterial colonization. At follow up, the majority of children remained caries free. Larger longitudinal studies are required to confirm whether salivary AMP levels are predictive of caries and whether their modulation offers therapeutic benefit. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

Science.gov (United States)

2012-01-01

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. PMID:22336469

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

Directory of Open Access Journals (Sweden)

Wong Kelvin KL

2012-02-01

Full Text Available Abstract 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.

Autoradiographic and ultrastructural studies on the human fibro-atheromatous plaque

Energy Technology Data Exchange (ETDEWEB)

Villaschi, S.; Spagnoli, L.G. (Universita degli Studi, Rome (Italy). Istituto di Anatomia ed Istologia Patologica)

1983-07-01

Foam cells, either myogenic or macrophagic, are commonly detected in experimental and human fibro-atheromatous plaques. Their role in human atherosclerosis is not yet understood. This paper reports on a preliminary autoradiographic study combined with ultrastructural observations in the human fibro-atheromatous plaque. Most of the autoradiographic silver grains appeared on foam cells and monocytelike cells, thus suggesting a local proliferation of these cells.

Autoradiographic and ultrastructural studies on the human fibro-atheromatous plaque

International Nuclear Information System (INIS)

Villaschi, Sergio; Spagnoli, L.G.

1983-01-01

Foam cells, either myogenic or macrophagic, are commonly detected in experimental and human fibro-atheromatous plaques. Their role in human atherosclerosis is not yet understood. This paper reports on a preliminary autoradiographic study combined with ultrastructural observations in the human fibro-atheromatous plaque. Most of the autoradiographic silver grains appeared on foam cells and monocytelike cells, thus suggesting a local proliferation of these cells. (author)

Plaque disruption by coronary computed tomographic angiography in stable patients vs. acute coronary syndrome: a feasibility study.

Science.gov (United States)

Bilolikar, Abhay N; Goldstein, James A; Madder, Ryan D; Chinnaiyan, Kavitha M

2016-03-01

This study was designed to determine whether coronary CT angiography (CTA) can detect features of plaque disruption in clinically stable patients and to compare lesion prevalence and features between stable patients and those with acute coronary syndrome (ACS). We retrospectively identified patients undergoing CTA, followed by invasive coronary angiography (ICA) within 60 days. Quantitative 3-vessel CTA lesion analysis was performed on all plaques ≥25% stenosis to assess total plaque volume, low attenuation plaque (LAP, disruption, including ulceration and intra-plaque dye penetration (IDP). ICA was employed as a reference standard for disruption. A total of 145 (94 ACS and 51 stable) patients were identified. By CTA, plaque disruption was evident in 77.7% of ACS cases. Although more common among those with ACS, CTA also detected plaque disruption in 37.3% of clinically stable patients (P disruption as determined by CTA. Though the prevalence of plaque disruption is less than patients with ACS, these findings support the concept that some clinically stable patients may harbour 'silent' disrupted plaques. These findings may have implications for detection of 'at risk' plaques and patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Human macrophage foam cells degrade atherosclerotic plaques through cathepsin K mediated processes

DEFF Research Database (Denmark)

Barascuk, Natasha; Skjøt-Arkil, Helene; Register, Thomas C

2010-01-01

BACKGROUND: Proteolytic degradation of Type I Collagen by proteases may play an important role in remodeling of atherosclerotic plaques, contributing to increased risk of plaque rupture.The aim of the current study was to investigate whether human macrophage foam cells degrade the extracellular...... matrix (ECM) of atherosclerotic plaques by cathepsin K mediated processes. METHODS: We 1) cultured human macrophages on ECM and measured cathepsin K generated fragments of type I collagen (C-terminal fragments of Type I collagen (CTX-I) 2) investigated the presence of CTX-I in human coronary arteries......-I in areas of intimal hyperplasia and in shoulder regions of advanced plaques. Treatment of human monocytes with M-CSF or M-CSF+LDL generated macrophages and foam cells producing CTX-I when cultured on type I collagen enriched matrix. Circulating levels of CTX-I were not significantly different in women...

Type D personality and coronary atherosclerotic plaque vulnerability: The potential mediating effect of health behavior.

Science.gov (United States)

Cheng, Fangman; Lin, Ping; Wang, Yini; Liu, Guojie; Li, Ling; Yu, Huai; Yu, Bo; Zhao, Zhenjuan; Gao, Xueqin

2018-05-01

The association between type D personality and coronary plaque vulnerability has been suggested. The objective of the study was to evaluate the potential mediating effects of health behavior on the association between type D personality and plaque vulnerability in coronary artery disease (CAD) patients. A total of 319 CAD patients were assessed for type D personality and health behavior via self-administered questionnaires. The plaque vulnerability, evaluated according to characteristics, accompaniment, and outcomes of plaque, was assessed by optical coherence tomography. Regression analysis showed that type D personality was independently associated with lipid plaque (odds ratio [OR] = 2.387, p = 0.001), thin cap fibroatheroma (TCFA) (OR = 2.366, p = 0.001), rupture (OR = 2.153, p = 0.002), and lipid arc (β = -0.291, p vulnerability. Psychological stress mediated the relationship between type D and lipid plaque (p = 0.030), TCFA (p = 0.034), and rupture (p = 0.013). Living habits significantly mediated the relationship between type D and lipid plaque (p = 0.028), TCFA (p = 0.036), but not rupture (p = 0.066). Participating in activities was not a significant mediator of the relationship between type D personality and lipid plaque (p = 0.115), TCFA (p = 0.115), or rupture (p = 0.077). Health behaviors (psychological stress and living habits) may be mediators of the association between type D personality and plaque vulnerability. Copyright © 2018 Elsevier Inc. All rights reserved.

Evaluation of chlorhexidine 0.05% with the adjunct of fluoride 0.05% in the inhibition of plaque formation: a double blind, crossover, plaque regrowth study.

Science.gov (United States)

De Siena, F; Del Fabbro, M; Corbella, S; Taschieri, S; Weinstein, R

2013-08-01

The aim of this study was to evaluate the effect of mouthrinses containing 0.05% chlorhexidine + 0.05% fluoride solution on early dental plaque regrowth. Thirty periodontally healthy subjects were included in the study. A crossover 4-day plaque regrowth protocol was adopted. The test product was initially used in 15 patients, while a placebo was administered to the other 15 patients. Then, after a washout period, each patient used the other product. No other oral hygiene manoeuvre was allowed. Full-mouth plaque and bleeding scores (FMPS and FMBS) were evaluated at baseline and after 4 days. All subjects completed the study. The mean age was 27 ± 8.4 years. Five patients were smokers with a mean daily consumption of 1 ± 2.5 cigarettes. FMPS at baseline was 8.0 ± 4.4 for control group and 7.9 ± 3.8 for test group, without significant difference. After the 4-day plaque regrowth the mean FMPS significantly increased to 31.9 ± 16.5 and 36.3 ± 16.1 for control and test group, respectively (no significant difference between the two groups). The test product was safe and well tolerated by subjects. The similar outcomes of the two experimental groups suggest that the two products have an equivalent effect on early dental plaque regrowth. Studies with longer follow-up are needed to clarify whether there is a beneficial long-term effect of daily rinses with the tested solution. © 2012 John Wiley & Sons A/S.

Identification and analysis of senile plaques using nuclear microscopy

Energy Technology Data Exchange (ETDEWEB)

Landsberg, J P; Roberts, J M; Grime, G W; Watt, F [Nuclear Physics Lab., Oxford (UK); McDonald, B [Dept. of Neuropathology, Radcliffe Infirmary, Oxford (UK) Nuffield Dept. of Pathology, John Radcliffe Hospital, Oxford (UK) MRC Neuroanatomical Unit, Dept. of Pharmacology, Oxford (UK)

1991-03-01

The senile plaques and neuro-fibrillary tangles which form part of the pathology of Alzheimer's disease have come under increasing scrutiny over the last decade. In particular, much work has been done investigating their elemental composition. The suggestion that 75-100% of tensile plaques with mature cores contain aluminium and silicon, probably in the form of alumino-silicates, has led to increasing speculation about the role of these elements in the disease. SPM preliminary studies suggest that aluminium and silicon are not present in as great a proportion of senile plaques as presented in the literature. The situation is complicated by the fact that airborn and solubilised salts of aluminium and silicon may be encountered as contamination. They have been found, for example, in granular or crystalline form in the Aristar grade organic laboratory reagents used for staining the tissue, and in the pure pioloform used to back the samples. The latest results from scans of stained and unstained Alzheimer tissue are presented. (orig.).

Identification and analysis of senile plaques using nuclear microscopy

International Nuclear Information System (INIS)

Landsberg, J.P.; Roberts, J.M.; Grime, G.W.; Watt, F.; McDonald, B.

1991-01-01

The senile plaques and neuro-fibrillary tangles which form part of the pathology of Alzheimer's disease have come under increasing scrutiny over the last decade. In particular, much work has been done investigating their elemental composition. The suggestion that 75-100% of tensile plaques with mature cores contain aluminium and silicon, probably in the form of alumino-silicates, has led to increasing speculation about the role of these elements in the disease. SPM preliminary studies suggest that aluminium and silicon are not present in as great a proportion of senile plaques as presented in the literature. The situation is complicated by the fact that airborn and solubilised salts of aluminium and silicon may be encountered as contamination. They have been found, for example, in granular or crystalline form in the Aristar grade organic laboratory reagents used for staining the tissue, and in the pure pioloform used to back the samples. The latest results from scans of stained and unstained Alzheimer tissue are presented. (orig.)

HDL-mimetic PLGA nanoparticle to target atherosclerosis plaque macrophages.

Science.gov (United States)

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

2015-03-18

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

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

Science.gov (United States)

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

2009-06-01

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

The burden of illness of osteoporosis in Canada.

Science.gov (United States)

Tarride, J-E; Hopkins, R B; Leslie, W D; Morin, S; Adachi, J D; Papaioannou, A; Bessette, L; Brown, J P; Goeree, R

2012-11-01

To update the 1993 burden of illness of osteoporosis in Canada, administrative and community data were used to calculate the 2010 costs of osteoporosis at $2.3 billion in Canada or 1.3% of Canada's healthcare expenditures. Prevention of fractures in high-risk individuals is key to decrease the financial burden of osteoporosis. Since the 1996 publication of the burden of osteoporosis in 1993 in Canada, the population has aged and the management of osteoporosis has changed. The study purpose was to estimate the current burden of illness due to osteoporosis in Canadians aged 50 and over. Analyses were conducted using five national administrative databases from the Canadian Institute for Health Information for the fiscal-year ending March 31 2008 (FY 2007/2008). Gaps in national data were supplemented by provincial and community data extrapolated to national levels. Osteoporosis-related fractures were identified using a combination of most responsible diagnosis at discharge and intervention codes. Fractures associated with severe trauma codes were excluded. Costs, expressed in 2010 dollars, were calculated for osteoporosis-related hospitalizations, emergency care, same day surgeries, rehabilitation, continuing care, homecare, long-term care, prescription drugs, physician visits, and productivity losses. Sensitivity analyses were conducted to measure the impact on the results of key assumptions. Osteoporosis-related fractures were responsible for 57,413 acute care admissions and 832,594 hospitalized days in FY 2007/2008. Acute care costs were estimated at $1.2 billion. When outpatient care, prescription drugs, and indirect costs were added, the overall yearly cost of osteoporosis was over $2.3 billion for the base case analysis and as much as $3.9 billion if a proportion of Canadians were assumed to be living in long-term care facilities due to osteoporosis. Osteoporosis is a chronic disease that affects a large segment of the adult population and results in a

Phase-based vascular input function: Improved quantitative DCE-MRI of atherosclerotic plaques

NARCIS (Netherlands)

van Hoof, R. H. M.; Hermeling, E.; Truijman, M. T. B.; van Oostenbrugge, R. J.; Daemen, J. W. H.; van der Geest, R. J.; van Orshoven, N. P.; Schreuder, A. H.; Backes, W. H.; Daemen, M. J. A. P.; Wildberger, J. E.; Kooi, M. E.

2015-01-01

Purpose: Quantitative pharmacokinetic modeling of dynamic contrast-enhanced (DCE)-MRI can be used to assess atherosclerotic plaque microvasculature, which is an important marker of plaque vulnerability. Purpose of the present study was (1) to compare magnitude-versus phase-based vascular input

Multicenter assessment of the reproducibility of volumetric radiofrequency-based intravascular ultrasound measurements in coronary lesions that were consecutively stented

DEFF Research Database (Denmark)

Huisman, Jennifer; Egede, Rasmus; Rdzanek, Adam

2012-01-01

To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility...... of volumetric VH-IVUS measurements, experienced analysts of 4 European IVUS centers performed independent analyses (in total 8,052 cross-sectional analyses) to obtain volumetric data of 40 coronary segments (length 20.0 ± 0.3 mm) from target lesions prior to percutaneous intervention that were performed...... in the setting of stable (65%) or unstable angina pectoris (35%). Geometric and compositional VH-IVUS measurements were highly correlated for the different comparisons. Overall intraclass correlation for vessel, lumen, plaque volume and plaque burden was 0.99, 0.92, 0.96, and 0.83, respectively; for fibrous...

Predicting carotid artery disease and plaque instability from cell-derived microparticles.

Science.gov (United States)

Wekesa, A L; Cross, K S; O'Donovan, O; Dowdall, J F; O'Brien, O; Doyle, M; Byrne, L; Phelan, J P; Ross, M D; Landers, R; Harrison, M

2014-11-01

Cell-derived microparticles (MPs) are small plasma membrane-derived vesicles shed from circulating blood cells and may act as novel biomarkers of vascular disease. We investigated the potential of circulating MPs to predict (a) carotid plaque instability and (b) the presence of advanced carotid disease. This pilot study recruited carotid disease patients (aged 69.3 ± 1.2 years [mean ± SD], 69% male, 90% symptomatic) undergoing endarterectomy (n = 42) and age- and sex-matched controls (n = 73). Plaques were classified as stable (n = 25) or unstable (n = 16) post surgery using immunohistochemistry. Blood samples were analysed for MP subsets and molecular biomarkers. Odds ratios (OR) are expressed per standard deviation biomarker increase. Endothelial MP (EMP) subsets, but not any vascular, inflammatory, or proteolytic molecular biomarker, were higher (p < .05) in the unstable than the stable plaque patients. The area under the receiver operator characteristic curve for CD31(+)41(-) EMP in discriminating an unstable plaque was 0.73 (0.56-0.90, p < .05). CD31(+)41(-) EMP predicted plaque instability (OR = 2.19, 1.08-4.46, p < .05) and remained significant in a multivariable model that included transient ischaemic attack symptom status. Annexin V(+) MP, platelet MP (PMP) subsets, and C-reactive protein were higher (p < .05) in cases than controls. Annexin V(+) MP (OR = 3.15, 1.49-6.68), soluble vascular cell adhesion molecule-1 (OR = 1.64, 1.03-2.59), and previous smoking history (OR = 3.82, 1.38-10.60) independently (p < .05) predicted the presence of carotid disease in a multivariable model. EMP may have utility in predicting plaque instability in carotid patients and annexin V(+) MPs may predict the presence of advanced carotid disease in aging populations, independent of established biomarkers. Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Aortic plaque rupture in the setting of acute lower limb ischemia.

LENUS (Irish Health Repository)

O'Donnell, David H

2012-02-01

Acute aortic plaque rupture is an uncommon cause of acute lower limb ischemia. The authors report sequence computed tomographic imaging of a distal aortic plaque rupture in a young man with bilateral lower limb complications. Clinical awareness, prompt recognition and imaging, and appropriate treatment of this uncommon condition are necessary to improve patient outcomes.

Effects of Bristle Hardness & Duration of Manual Tooth brushing on Plaque Control

Directory of Open Access Journals (Sweden)

. Sunny

2017-03-01

Full Text Available Background: Oral health is an integral part of general health. Poor oral health can have adverse effect on general health hence a good oral health is very essential, which in turn is achieved by good oral hygiene. Even though, the concept of good oral hygiene evolved 5000 years back, it is only in the beginning of 19th century it gained more importance. (1 Dental caries and periodontal disease are the most commonly occurring diseases affecting mankind. Dental plaque is a very important factor in the causation of both the diseases. (2 Aims & Objectives: To evaluate efficacy of four different types of toothbrushes, with difference in duration of brushing along with different bristle hardness in removal of microbial plaque. Material & Methods: In a randomized controlled trial, four groups with 40 subjects used manual toothbrushes with either hard, medium, soft and ultra-soft bristles. On baseline examination, clinical parameter plaque index (Sillness & Loe, 1964 was recorded. Selected subjects were refrained from all kinds of oral hygiene measures for 24 hrs before clinical appointment. On the day of clinical appointment scores of pre and post brushing were recorded in each patient when brushing time was set for 1 minute and same procedure was repeated after a wash off period of 3 days and similar recordings were made with brushing time of 11/2minute. Primary outcome was measured with differences in the plaque index (Sillness & Loe, 1964 compared to baseline. Results: Significant reduction in mean value of plaque score was observed on comparing pre-brushing and post-brushing data in all the subjects irrespective of bristle hardness in both 1 minute and 11/2 minute groups. On increasing time duration from 1 minute to 11/2 minute intergroup comparison revealed that significant correlation exist in mean plaque score reduction in subjects using medium bristle brush, soft bristle brush, ultra-soft bristle brush. However, no significant reduction in

Atherosclerosis and the vulnerable plaque - imaging. Part II

International Nuclear Information System (INIS)

Worthley, S.G.; Helft, G.; Zaman, A.G.; Fuster, V.; Badimon, J.J.

2000-01-01

Atherosclerotic disease and its thrombotic complications remain the leading causes of mortality and morbidity in Western society. In Australia, cardiovascular disease (CVD) is responsible for one in every 2.4 (41%) deaths and is the leading single cause of mortality. The crucial final common process for the conversion of a non-occlusive, often clinically silent, atherosclerotic lesion to a potentially fatal condition is plaque disruption. The mortality associated with atherosclerotic disease relates to the acute coronary syndromes, including acute myocardial infarction (MI), unstable angina pectoris and sudden cardiac death. There is substantial clinical, experimental and post-mortem evidence demonstrating the role played by acute thrombosis upon a disrupted atherosclerotic plaque in the onset of acute coronary syndromes. Atherosclerotic plaque composition, rather than the stenotic severity, appears to be central in determining risk of both plaque rupture and subsequent thrombogenicity. In particular, a large lipid core and a thin fibrous cap render an atherosclerotic lesion susceptible or vulnerable to these complications. We are currently limited in our ability to identify accurately patients at risk for an acute coronary event. The armamentarium of diagnostic investigations, both non-invasive and invasive, currently clinically available is only able to provide us with data related to the stenotic severity of a coronary artery. The non-invasive testing includes stress-induced (exercise or pharmacologic) ischaemic changes in electrical repolarisation, wall motion or myocardial radioactive-tracer uptake. The invasive test of coronary angiography, although the current gold standard for the detection of coronary atherosclerotic disease, provides us with no data about the composition of the atherosclerotic lesion. However, the vast majority of acute coronary events involve a non-critically stenosed atherosclerotic lesion, and thus with currently available means of

Plaque-left-behind after brushing : intra-oral reservoir for antibacterial toothpaste ingredients

NARCIS (Netherlands)

Otten, Marieke P. T.; Busscher, Henk J.; Abbas, Frank; van der Mei, Henny C.; van Hoogmoed, Chris G.

2012-01-01

Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste

The time window of MRI of murine atherosclerotic plaques after administration of CB2 receptor targeted micelles: inter-scan variability and relation between plaque signal intensity increase and gadolinium content of inversion recovery prepared versus non-prepared fast spin echo

NARCIS (Netherlands)

te Boekhorst, B. C. M.; Bovens, S. M.; van de Kolk, C. W. A.; Cramer, M. J. M.; Doevendans, P. A. F. M.; ten Hove, M.; van der Weerd, L.; Poelmann, R.; Strijkers, G. J.; Pasterkamp, G.; van Echteld, C. J. A.

2010-01-01

Single fast spin echo scans covering limited time frames are mostly used for contrast-enhanced MRI of atherosclerotic plaque biomarkers. Knowledge on inter-scan variability of the normalized enhancement ratio of plaque (NER(plaque)) and relation between NER(plaque) and gadolinium content for

Diverse cellular architecture of atherosclerotic plaque derives from clonal expansion of a few medial SMCs

DEFF Research Database (Denmark)

Jacobsen, Kevin; Lund, Marie Bek; Shim, Jeong

2017-01-01

Fibrous cap smooth muscle cells (SMCs) protect atherosclerotic lesions from rupturing and causing thrombosis, while other plaque SMCs may have detrimental roles in plaque development. To gain insight into recruitment of different plaque SMCs, we mapped their clonal architecture in aggregation...... in the cap and heterogeneous ACTA2– SMCs in the plaque interior, including chondrocyte-like cells and cells with intracellular lipid and crystalline material. Fibrous cap SMCs were invariably arranged in endothelium-aligned clonal sheets, confirming results in the aggregation chimeras. Analysis of the clonal...

A study of plaque vascularization and inflammation using quantitative contrast-enhanced US and PET/CT

International Nuclear Information System (INIS)

Hjelmgren, Ola; Johansson, Lars; Prahl, Ulrica; Schmidt, Caroline; Fredén-Lindqvist, Johan; Bergström, Göran M.L.

2014-01-01

Background: Contrast-enhanced ultrasound (CEUS) is an in vivo methodology to quantify carotid plaque vascularization. Increased metabolism in plaques, measured as FDG uptake in PET/CT examination, has been associated with markers of inflammation in histological samples. In this study, we tested the association between FDG uptake and vascularization measured by CEUS to assess whether CEUS can be used as an in vivo marker of plaque vulnerability. Methods: After informed consent, subjects aged >60 years with carotid plaque height exceeding 2.5 mm were recruited. CEUS was performed and analyzed using earlier described protocol and software, Contrast Quantification Program, which calculates the fraction of the plaque being contrast positive (CQP value). PET/CT examination was performed within 3 months of CEUS (median time 7 days). PET/CT images were acquired 90 min after FDG injection (2.7 MBq/kg). FDG uptake was measured as tissue background index (TBI), calculated using Spearman's rho as mean standard uptake value (SUV) of the plaque divided by mean SUV in the jugular vein (mean of 7 measuring points). Local ethics committee approved the study. Results: We recruited 13 subjects (5 women) with a mean age of 71 years, 6 had a history of stroke or TIA, 1 had a history of ipsilateral stroke. CQP values showed a significant, positive correlation with TBI of carotid plaques, r = 0.67, p < 0.02. Conclusions: Plaque vascularization measured by CEUS correlates positively with FDG uptake measured by PET/CT in humans. This indicates an association between vascularization and inflammation and/or hypoxia, supporting the use of CEUS as a non-invasive method to detect plaque vulnerability

A study of plaque vascularization and inflammation using quantitative contrast-enhanced US and PET/CT

Energy Technology Data Exchange (ETDEWEB)

Hjelmgren, Ola, E-mail: ola.hjelmgren@wlab.gu.se [Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Department of Molecular and Clinical Medicine, Clinical Physiology, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Clinical Physiology, Gothenburg (Sweden); Johansson, Lars, E-mail: lars.johansson@radiol.uu.se [Uppsala University, Department of Radiology, Uppsala (Sweden); Prahl, Ulrica, E-mail: ulrica-prahl-gullberg@wlab.gu.se [Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Department of Molecular and Clinical Medicine, Clinical Physiology, Gothenburg (Sweden); Schmidt, Caroline, E-mail: caroline.schmidt@wlab.gu.se [Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Department of Molecular and Clinical Medicine, Clinical Physiology, Gothenburg (Sweden); Fredén-Lindqvist, Johan, E-mail: johan.freden-lindqvist@vgregion.se [Sahlgrenska University Hospital, Department of Clinical Physiology, Gothenburg (Sweden); Bergström, Göran M.L., E-mail: goran.bergstrom@hjl.gu.se [Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Department of Molecular and Clinical Medicine, Clinical Physiology, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Clinical Physiology, Gothenburg (Sweden)

2014-07-15

Background: Contrast-enhanced ultrasound (CEUS) is an in vivo methodology to quantify carotid plaque vascularization. Increased metabolism in plaques, measured as FDG uptake in PET/CT examination, has been associated with markers of inflammation in histological samples. In this study, we tested the association between FDG uptake and vascularization measured by CEUS to assess whether CEUS can be used as an in vivo marker of plaque vulnerability. Methods: After informed consent, subjects aged >60 years with carotid plaque height exceeding 2.5 mm were recruited. CEUS was performed and analyzed using earlier described protocol and software, Contrast Quantification Program, which calculates the fraction of the plaque being contrast positive (CQP value). PET/CT examination was performed within 3 months of CEUS (median time 7 days). PET/CT images were acquired 90 min after FDG injection (2.7 MBq/kg). FDG uptake was measured as tissue background index (TBI), calculated using Spearman's rho as mean standard uptake value (SUV) of the plaque divided by mean SUV in the jugular vein (mean of 7 measuring points). Local ethics committee approved the study. Results: We recruited 13 subjects (5 women) with a mean age of 71 years, 6 had a history of stroke or TIA, 1 had a history of ipsilateral stroke. CQP values showed a significant, positive correlation with TBI of carotid plaques, r = 0.67, p < 0.02. Conclusions: Plaque vascularization measured by CEUS correlates positively with FDG uptake measured by PET/CT in humans. This indicates an association between vascularization and inflammation and/or hypoxia, supporting the use of CEUS as a non-invasive method to detect plaque vulnerability.

Dosimetric Calculations of a Radioactive Eye Plaque used in Management of Ocular Melanoma Using Monte Carlo Simulations

Directory of Open Access Journals (Sweden)

P Shokrani

2009-10-01

Full Text Available Introduction & Objective: Brachytherapy using I-125 radioactive seeds in removable episcleral plaques (EP is often used in treatment of ocular malignant melanoma. Some radioactive seeds are fixed in a gold bowl-shaped plaque. The plaque is sutured to the sclera surface corresponding to the base of the intraocular tumor, allowing for a localized radiation dose delivery to the tumor. Minimum target doses as high as 85Gy are directed at malignant tumor. The aim of this study was to develop a Monte Carlo simulation of an ocular plaque in order to calculate the resulting isodose distributions. Materials & Methods: The MCNP-4C Monte Carlo code is used to simulate the plan of an episcleral plaque treatment. A 20-mm Collaborative Ocular Melanoma Study (COMS plaque with 3, I-125 seed of model 6711 was used. Resulting dose distributions, including central axis dose and off-axis dose profiles, were calculated in a water phantom with 12mm radius. The calculated dose distributions were compared to the corresponding dose measured by Knuten et al., 2001. Results: Central axis dose calculations represent a rapid dose fall off, which is an important factor in selection of appropriate eye plaque for management of tumors with known dimension. Calculated off-axis dose profiles show decreased dose uniformity at distances close to the plaque. Increasing of distance from the plaque resulted in increasing of the dose uniformity. Conclusion: Monte Carlo simulation of eye plaques can be used as a useful tool in process of design, development and treatment planning of ocular radioactive plaques.

125I eye plaque dose distribution including penumbra characteristics.

Science.gov (United States)

de la Zerda, A; Chiu-Tsao, S T; Lin, J; Boulay, L L; Kanna, I; Kim, J H; Tsao, H S

1996-03-01

The two main purposes of this work are (1) to determine the penumbra characteristics for 125I eye plaque and the relative influence of the plaque and eye-air interface on the dose distribution, and (2) to initiate development of a treatment planning algorithm for clinical dose calculations. Dose was measured in a newly designed solid water eye phantom for an 125I (6711) seed at the center of a 20 mm COMS eye plaque using thermoluminescent dosimeter (TLD) "cubes" and "minichips" inside and outside the eye, in the longitudinal and transverse central planes. TLD cubes were used in most locations, except for short distances from the seed and in the penumbra region. In the presence of both the plaque and the eye-air interface, the dose along the central axis was found to be reduced by 10% at 1 cm and up to 20% at 2.5 cm, relative to the bulk homogeneous phantom case. In addition, the overall dose reduction was greater for larger off-axis coordinates at a given depth. The penumbra characteristics due to the lip collimation were quantified, particularly the dependence of penumbra center and width on depth. Only small differences were observed between the profiles in the transverse and longitudinal planes. In the bulk geometry (without the eye-air interface), the dose reduction due to the presence of the plaque alone was found to be 7% at a depth of 2.5 cm. The additional reduction of 13% observed, with the presence of eye-air interface (20% combined), can be attributed to the lack of backscattering from the air in front of the eye. The dose-reduction effect due to the anterior air interface alone became unnoticeable at a depth of 1.1 cm (1.5 cm from the eye-air interface). An analytic fit to measured data was developed for clinical dose calculations for a centrally loaded seed. The central axis values of the dose rates multiplied by distance squared, Dr2, were fitted with a double exponential function of depth. The off-axis profile of Dr2, at a given depth, was

Comparative efficacy of two battery-powered toothbrushes on dental plaque removal.

Science.gov (United States)

Ruhlman, C Douglas; Bartizek, Robert D; Biesbrock, Aaron R

2002-01-01

A number of clinical studies have consistently demonstrated that power toothbrushes deliver superior plaque removal compared to manual toothbrushes. Recently, a new power toothbrush (Crest SpinBrush) has been marketed with a design that fundamentally differs from other marketed power toothbrushes. Other power toothbrushes feature a small, round head designed to oscillate for enhanced cleaning between the teeth and below the gumline. The new power toothbrush incorporates a similar round oscillating head in conjunction with fixed bristles, which allows the user to brush with optimal manual brushing technique. The objective of this randomized, examiner-blind, parallel design study was to compare the plaque removal efficacy of a positive control power toothbrush (Colgate Actibrush) to an experimental toothbrush (Crest SpinBrush) following a single use among 59 subjects. Baseline plaque scores were 1.64 and 1.40 for the experimental toothbrush and control toothbrush treatment groups, respectively. With regard to all surfaces examined, the experimental toothbrush delivered an adjusted (via analysis of covariance) mean difference between baseline and post-brushing plaque scores of 0.47, while the control toothbrush delivered an adjusted mean difference of 0.33. On average, the difference between toothbrushes was statistically significant (p = 0.013). Because the covariate slope for the experimental group was statistically significantly greater (p = 0.001) than the slope for the control group, a separate slope model was used. Further analysis demonstrated that the experimental group had statistically significantly greater plaque removal than the control group for baseline plaque scores above 1.43. With respect to buccal surfaces, using a separate slope analysis of covariance, the experimental toothbrush delivered an adjusted mean difference between baseline and post-brushing plaque scores of 0.61, while the control toothbrush delivered an adjusted mean difference of 0

16S rRNA-based detection of oral pathogens in coronary atherosclerotic plaque

Directory of Open Access Journals (Sweden)

Mahendra Jaideep

2010-01-01

Full Text Available Background: Atherosclerosis develops as a response of the vessel wall to injury. Chronic bacterial infections have been associated with an increased risk for atherosclerosis and coronary artery disease. The ability of oral pathogens to colonize in coronary atheromatous plaque is well known. Aim: The aim of this study was to detect the presence of Treponema denticola, Porphyromonas gingivalis and Campylobacter rectus in the subgingival and atherosclerotic plaques of patients with coronary artery disease. Materials and Methods: Fifty-one patients in the age group of 40-80 years with coronary artery disease were selected for the study. DNA was extracted from the plaque samples. The specific primers for T. denticola, C. rectus and P. gingivalis were used to amplify a part of the 16S rRNA gene by polymerase chain reaction. Statistical Analysis Used: Chi-square analysis, correlation coefficient and prevalence percentage of the microorganisms were carried out for the analysis. Results: Of the 51 patients, T. denticola, C. rectus and P. gingivalis were detected in 49.01%, 21.51% and 45.10% of the atherosclerotic plaque samples. Conclusions: Our study revealed the presence of bacterial DNA of the oral pathogenic microorganisms in coronary atherosclerotic plaques. The presence of the bacterial DNA in the coronary atherosclerotic plaques in significant proportion may suggest the possible relationship between periodontal bacterial infection and genesis of coronary atherosclerosis.

Efficacy of inter-dental mechanical plaque control in managing gingivitis--a meta-review.

Science.gov (United States)

Sälzer, Sonja; Slot, Dagmar E; Van der Weijden, Fridus A; Dörfer, Christof E

2015-04-01

What is the effect of mechanical inter-dental plaque removal in addition to toothbrushing, on managing gingivitis using various formats of inter-dental self-care in adults based on evidence gathered from existing systematic reviews? Three Internet sources were searched by a strategy designed to include systematic reviews on inter-dental cleaning devices. Plaque and gingivitis scores were the primary parameters of interest. Characteristics of selected papers were extracted. The potential risk of bias was estimated and the acquired evidence was graded. Screening of 395 papers resulted in six systematic reviews. Two papers evaluated the efficacy of dental floss, two of inter-dental brushes (IDB), one of woodsticks and one of the oral irrigator. Weak evidence of unclear or small magnitude was retrieved that supported dental floss, woodsticks and the oral irrigator to reduce gingivitis in addition to toothbrushing. No concomitant evidence for an effect on plaque emerged. There is moderate evidence that IDBs in combination with toothbrushing reduce both plaque and gingivitis. Evidence suggests that inter-dental cleaning with IDBs is the most effective method for inter-dental plaque removal. The majority of available studies fail to demonstrate that flossing is generally effective in plaque removal. All investigated devices for inter-dental self-care seem to support the management of gingivitis, however, to a varying extend. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Palladium-103 plaque radiotherapy for choroidal melanoma: an 11-year study

International Nuclear Information System (INIS)

Finger, Paul T.; Berson, Anthony; Ng, Tracy; Szechter, Andrzej

2002-01-01

Purpose: To describe 11 years of experience with 103 Pd ophthalmic plaque brachytherapy for intraocular melanoma. Methods and Materials: Since 1990, 152 patients have been diagnosed with uveal melanoma, found to be negative for metastatic disease, and treated with 103 Pd radioactive plaque radiotherapy. This study presents the first 100 patients treated with 103 Pd and followed for ≥2 years. Plaques were sewn to the episclera to cover the base of the intraocular tumor. Treatment involved delivery of a mean apical radiation dose of 80.5 Gy during 5-7 days' continuous treatment. Patients were evaluated for local tumor control, visual acuity, radiation damage (retinopathy, optic neuropathy, cataract), and metastatic disease. Results: Patients in this series were followed for a mean of 4.6 years (55.4 months). 103 Pd seeds were found to be equivalent to 125 I with respect to plaque manufacture and ease of dosimetric calculations. We noted a local control rate of 96% and six secondary enucleations. Including the enucleated patients, the visual acuity evaluations revealed that 35% lost six or more lines of vision and 73% had vision of 20/200 or better. Conclusion: Long-term results now exist describing the use of 103 Pd plaque radiotherapy for uveal (iris, ciliary body, and choroidal) melanoma. Compared with the results from centers using 125 I, patients in this series experienced equivalent local control rates and better visual function

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

Science.gov (United States)