Randomized Trial of Plaque-Identifying Toothpaste: Decreasing Plaque and Inflammation.

PubMed

Fasula, Kim; Evans, Carla A; Boyd, Linda; Giblin, Lori; Belavsky, Benjamin Z; Hetzel, Scott; McBride, Patrick; DeMets, David L; Hennekens, Charles H

2017-06-01

Randomized data are sparse about whether a plaque-identifying toothpaste reduces dental plaque and nonexistent for inflammation. Inflammation is intimately involved in the pathogenesis of atherosclerosis and is accurately measured by high-sensitivity C-reactive protein (hs-CRP), a sensitive marker for cardiovascular disease. The hypotheses that Plaque HD (TJA Health LLC, Joliet, Ill), a plaque-identifying toothpaste, produces statistically significant reductions in dental plaque and hs-CRP were tested in this randomized trial. Sixty-one apparently healthy subjects aged 19 to 44 years were assigned at random to this plaque-identifying (n = 31) or placebo toothpaste (n = 30) for 60 days. Changes from baseline to follow-up in dental plaque and hs-CRP were assessed. In an intention-to-treat analysis, the plaque-identifying toothpaste reduced mean plaque score by 49%, compared with a 24% reduction in placebo (P = .001). In a prespecified subgroup analysis of 38 subjects with baseline levels >0.5 mg/L, the plaque-identifying toothpaste reduced hs-CRP by 29%, compared with a 25% increase in placebo toothpaste (P = .041). This plaque-identifying toothpaste produced statistically significant reductions in dental plaque and hs-CRP. The observed reduction in dental plaque confirms and extends a previous observation. The observed reduction in inflammation supports the hypothesis of a reduction in risks of cardiovascular disease. The direct test of this hypothesis requires a large-scale randomized trial of sufficient size and duration designed a priori to do so. Such a finding would have major clinical and public health implications. Copyright © 2017 Elsevier Inc. All rights reserved.

Vulnerable atherosclerotic plaque detection by resonance Raman spectroscopy

NASA Astrophysics Data System (ADS)

Liu, Cheng-hui; Boydston-White, Susie; Weisberg, Arel; Wang, Wubao; Sordillo, Laura A.; Perotte, Adler; Tomaselli, Vincent P.; Sordillo, Peter P.; Pei, Zhe; Shi, Lingyan; Alfano, Robert R.

2016-12-01

A clear correlation has been observed between the resonance Raman (RR) spectra of plaques in the aortic tunica intimal wall of a human corpse and three states of plaque evolution: fibrolipid plaques, calcified and ossified plaques, and vulnerable atherosclerotic plaques (VPs). These three states of atherosclerotic plaque lesions demonstrated unique RR molecular fingerprints from key molecules, rendering their spectra unique with respect to one another. The vibrational modes of lipids, cholesterol, carotenoids, tryptophan and heme proteins, the amide I, II, III bands, and methyl/methylene groups from the intrinsic atherosclerotic VPs in tissues were studied. The salient outcome of the investigation was demonstrating the correlation between RR measurements of VPs and the thickness measurements of fibrous caps on VPs using standard histopathology methods, an important metric in evaluating the stability of a VP. The RR results show that VPs undergo a structural change when their caps thin to 66 μm, very close to the 65-μm empirical medical definition of a thin cap fibroatheroma plaque, the most unstable type of VP.

Validation of Noninvasive In Vivo Compound Ultrasound Strain Imaging Using Histologic Plaque Vulnerability Features.

PubMed

Hansen, Hendrik H G; de Borst, Gert Jan; Bots, Michiel L; Moll, Frans L; Pasterkamp, Gerard; de Korte, Chris L

2016-11-01

Carotid plaque rupture is a major cause of stroke. Key issue for risk stratification is early identification of rupture-prone plaques. A noninvasive technique, compound ultrasound strain imaging, was developed providing high-resolution radial deformation/strain images of atherosclerotic plaques. This study aims at in vivo validation of compound ultrasound strain imaging in patients by relating the measured strains to typical features of vulnerable plaques derived from histology after carotid endarterectomy. Strains were measured in 34 severely stenotic (>70%) carotid arteries at the culprit lesion site within 48 hours before carotid endarterectomy. In all cases, the lumen-wall boundary was identifiable on B-mode ultrasound, and the imaged cross-section did not move out of the imaging plane from systole to diastole. After endarterectomy, the plaques were processed using a validated histology analysis technique. Locally elevated strain values were observed in regions containing predominantly components related to plaque vulnerability, whereas lower values were observed in fibrous, collagen-rich plaques. The median strain of the inner plaque layer (1 mm thickness) was significantly higher (P<0.01) for (fibro)atheromatous (n=20, strain=0.27%) than that for fibrous plaques (n=14, strain=-0.75%). Also, a significantly larger area percentage of the inner layer revealed strains above 0.5% for (fibro)atheromatous (45.30%) compared with fibrous plaques (31.59%). (Fibro)atheromatous plaques were detected with a sensitivity, specificity, positive predictive value, and negative predictive value of 75%, 86%, 88%, and 71%, respectively. Strain did not significantly correlate with fibrous cap thickness, smooth muscle cell, or macrophage concentration. Compound ultrasound strain imaging allows differentiating (fibro)atheromatous from fibrous carotid artery plaques. © 2016 American Heart Association, Inc.

Type D personality and coronary atherosclerotic plaque vulnerability: The potential mediating effect of health behavior.

PubMed

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 < 0.001). Mediation analyses showed that aspects of health behavior were significant mediators of the relationship between type D personality and plaque 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.

The usefulness of optical analyses for detecting vulnerable plaques using rabbit models

NASA Astrophysics Data System (ADS)

Nakai, Kanji; Ishihara, Miya; Kawauchi, Satoko; Shiomi, Masashi; Kikuchi, Makoto; Kaji, Tatsumi

2011-03-01

Purpose: Carotid artery stenting (CAS) has become a widely used option for treatment of carotid stenosis. Although technical improvements have led to a decrease in complications related to CAS, distal embolism continues to be a problem. The purpose of this research was to investigate the usefulness of optical methods (Time-Resolved Laser- Induced Fluorescence Spectroscopy [TR-LIFS] and reflection spectroscopy [RS] as diagnostic tools for assessment of vulnerable atherosclerotic lesions, using rabbit models of vulnerable plaque. Materials & Methods: Male Japanese white rabbits were divided into a high cholesterol diet group and a normal diet group. In addition, we used a Watanabe heritable hyperlipidemic (WHHL) rabbit, because we confirmed the reliability of our animal model for this study. Experiment 1: TR-LIFS. Fluorescence was induced using the third harmonic wave of a Q switch Nd:YAG laser. The TR-LIFS was performed using a photonic multi-channel analyzer with ICCD (wavelength range, 200 - 860 nm). Experiment 2: RS. Refection spectra in the wavelength range of 900 to 1700 nm were acquired using a spectrometer. Results: In the TR-LIFS, the wavelength at the peak was longer by plaque formation. The TR-LIFS method revealed a difference in peak levels between a normal aorta and a lipid-rich aorta. The RS method showed increased absorption from 1450 to 1500 nm for lipid-rich plaques. We observed absorption around 1200 nm due to lipid only in the WHHL group. Conclusion: These methods using optical analysis might be useful for diagnosis of vulnerable plaques. Keywords: Carotid artery stenting, vulnerable plaque, Time-Resolved Laser-Induced Fluorescence

Emerging applications of nanotechnology for the diagnosis and management of vulnerable atherosclerotic plaques

PubMed Central

Yu, Shann S.; Ortega, Ryan A.; Reagan, Brendan W.; McPherson, John A.; Sung, Hak-Joon; Giorgio, Todd D.

2017-01-01

An estimated 16 million people in the United States have coronary artery disease (CAD), and approximately 325,000 people die annually from cardiac arrest. About two-thirds of unexpected cardiac deaths occur without prior recognition of cardiac disease. A vast majority of these deaths are attributable to the rupture of ‘Vulnerable atherosclerotic plaques’. Clinically, plaque vulnerability is typically assessed through imaging techniques, and ruptured plaques leading to acute myocardial infarction are treated through angioplasty or stenting. Despite significant advances, it is clear that current imaging methods are insufficiently capable for elucidating plaque composition—which is a key determinant of vulnerability. Further, the exciting improvement in the treatment of CAD afforded by stenting procedures has been buffered by significant undesirable host-implant effects, including restenosis and late thrombosis. Nanotechnology has led to some potential solutions to these problems by yielding constructs that interface with plaque cellular components at an unprecedented size scale. By leveraging the innate ability of macrophages to phagocytose nanoparticles, contrast agents can now be targeted to plaque inflammatory activity. Improvements in nano-patterning procedures have now led to increased ability to regenerate tissue isotropy directly on stents, enabling gradual regeneration of normal, physiologic vascular structures. Advancements in immunoassay technologies promise lower costs for biomarker measurements, and in the near future, may enable the addition of routine blood testing to the clinician’s toolbox—decreasing the costs of atherosclerosis-related medical care. These are merely three examples among many stories of how nanotechnology continues to promise advances in the diagnosis and treatment of vulnerable atherosclerotic plaques. PMID:21834059

A Review of Intravascular Ultrasound–Based Multimodal Intravascular Imaging: The Synergistic Approach to Characterizing Vulnerable Plaques

PubMed Central

Ma, Teng; Zhou, Bill; Hsiai, Tzung K.; Shung, K. Kirk

2015-01-01

Catheter-based intravascular imaging modalities are being developed to visualize pathologies in coronary arteries, such as high-risk vulnerable atherosclerotic plaques known as thin-cap fibroatheroma, to guide therapeutic strategy at preventing heart attacks. Mounting evidences have shown three distinctive histopathological features—the presence of a thin fibrous cap, a lipid-rich necrotic core, and numerous infiltrating macrophages—are key markers of increased vulnerability in atherosclerotic plaques. To visualize these changes, the majority of catheter-based imaging modalities used intravascular ultrasound (IVUS) as the technical foundation and integrated emerging intravascular imaging techniques to enhance the characterization of vulnerable plaques. However, no current imaging technology is the unequivocal “gold standard” for the diagnosis of vulnerable atherosclerotic plaques. Each intravascular imaging technology possesses its own unique features that yield valuable information although encumbered by inherent limitations not seen in other modalities. In this context, the aim of this review is to discuss current scientific innovations, technical challenges, and prospective strategies in the development of IVUS-based multi-modality intravascular imaging systems aimed at assessing atherosclerotic plaque vulnerability. PMID:26400676

Carotid artery stenting for vulnerable plaques on MR angiography and ultrasonography: utility of dual protection and blood aspiration method.

PubMed

Sakamoto, Shigeyuki; Kiura, Yoshihiro; Okazaki, Takahito; Shinagawa, Katsuhiro; Ishii, Daizo; Ichinose, Nobuhiko; Kurisu, Kaoru

2016-10-01

Carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis with vulnerable plaques is controversial. We analyzed the effect of a dual protection and blood aspiration method during CAS in patients with vulnerable plaques. A total of 111 patients with ICA stenosis underwent CAS using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method. In 103 of 111 patients, preoperative carotid plaque was estimated by both 3 T MRI and ultrasonography (US). ICA plaques with a high intensity signal on time-of-flight-MR angiography (TOF-MRA) and/or mobile component on US were defined as vulnerable plaques. We assessed major adverse events (MAE) (ie, major stroke, myocardial infarction, and death) and hyperintense spots on diffusion-weighted images (DWI) after CAS. We then evaluated the visible debris captured by dual protection and blood aspiration during CAS. The preoperative ICA plaque on TOF-MRA and US was judged to be vulnerable in 48.5% (50/103 patients). The success rate of the CAS procedure was 100% with no MAE within 30 days. DWI showed small hyperintense spots in 18% (9/50 patients) and 18.9% (10/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively. Visible debris was captured in 68% (34/50 patients) and 45.3% (24/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively (p=0.0286). The combination of dual protection and blood aspiration could provide effective distal embolic protection although vulnerable plaques on TOF-MRA and US had a high incidence of debris during CAS. Thus, CAS using dual protection and blood aspiration is safe in patients with vulnerable plaques. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Evaluation of carotid plaque vulnerability in vivo: Correlation between dynamic contrast-enhanced MRI and MRI-modified AHA classification.

PubMed

Ge, Xiaoqian; Zhou, Zien; Zhao, Huilin; Li, Xiao; Sun, Beibei; Suo, Shiteng; Hackett, Maree L; Wan, Jieqing; Xu, Jianrong; Liu, Xiaosheng

2017-09-01

To noninvasively monitor carotid plaque vulnerability by exploring the relationship between pharmacokinetic parameters (PPs) of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and plaque types based on MRI-modified American Heart Association (AHA) classification, as well as to assess the ability of PPs in discrimination between stable and vulnerable plaques suspected on MRI. Of 70 consecutive patients with carotid plaques who volunteered for 3.0T MRI (3D time-of-flight [TOF], T 1 -weighted, T 2 -weighted, 3D magnetization-prepared rapid acquisition gradient-echo [MP-RAGE] and DCE-MRI), 66 participants were available for analysis. After plaque classification according to MRI-modified AHA Lesion-Type (LT), PPs (K trans , k ep , v e , and v p ) of DCE-MRI were measured. The Extended Tofts model was used for calculation of PPs. For participants with multiple carotid plaques, the plaque with the worst MRI-modified AHA LT was chosen for analysis. Correlations between PPs and plaque types and the ability of these parameters to distinguish stable and vulnerable plaques suspected on MRI were assessed. Significant positive correlation between K trans and LT III to VI was found (ρ = 0.532, P < 0.001), as was the correlation between k ep and LT III to VI (ρ = 0.409, P < 0.001). Stable and vulnerable plaques suspected on MRI could potentially be distinguished by K trans (sensitivity 83%, specificity 100%) and k ep (sensitivity 77%, specificity 91%). K trans and k ep from DCE-MRI can provide quantitative information to monitor plaque vulnerability in vivo and differentiate vulnerable plaques suspected on MRI from stable ones. These two parameters could be adopted as imaging biomarkers for plaque characterization and risk stratification. 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:870-876. © 2017 International Society for Magnetic Resonance in Medicine.

Interactions among variants in TXA2R, P2Y12 and GPIIIa are associated with carotid plaque vulnerability in Chinese population.

PubMed

Yi, Xingyang; Lin, Jing; Luo, Hua; Zhou, Ju; Zhou, Qiang; Wang, Yanfen; Wang, Chun

2018-04-03

The associations between variants in platelet activation-relevant genes and carotid plaque vulnerability are not fully understood. The aim of the present study was to investigate the associations of the variants in platelet activation-relevant genes and interactions among these variants with carotid plaque vulnerability. There were no significant differences in the frequencies of genotypes of the 11 variants between patients and controls. Among 396 patients, 102 patients had not carotid plaque, 106 had VP, and 188 had SP. The 11 variants were not independently associated with risk of carotid plaque vulnerability after adjusting for potential confounding variables. However, the GMDR analysis showed that there were synergistic effects of gene-gene interactions among TXA2Rr s1131882, GPIIIa rs2317676 and P2Y12 rs16863323 on carotid plaque vulnerability. The high-risk interactions among the three variants were associated with high platelet activation, and independently associated with the risk of carotid plaque vulnerability. Eleven variants in platelet activation-relevant genes were examined using mass spectrometry methods in 396 ischemic stroke patients and 291controls. Platelet-leukocyte aggregates and platelet aggregation were also measured. Carotid plaques were assessed by B-mode ultrasound. According to the results of ultrasound, the patients were stratified into three groups: non-plaque group, vulnerable plaque (VP) group and stable plaque (SP) group. Furthermore, gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) methods. The rs1131882, rs2317676, and rs16863323 three-loci interactions may confer a higher risk of carotid plaque vulnerability, and might be potential markers for plaque instability.

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

PubMed Central

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

2012-01-01

Enhanced matrix metalloproteinases (MMPs) activity is implicated in the process of atherosclerotic plaque instability. We hypothesized that doxycycline, a broad MMPs inhibitor, was as effective as simvastatin in reducing the incidence of plaque disruption. Thirty rabbits underwent aortic balloon injury and were fed a high-fat diet for 20 weeks. At the end of week 8, the rabbits were divided into three groups for 12-week treatment: a doxycycline-treated group that received oral doxycycline at a dose of 10 mg/kg/d, a simvastatin-treated group that received oral simvastatin at a dose of 5 mg/kg/d, and a control group that received no treatment. At the end of week 20, pharmacological triggering was performed to induce plaque rupture. Biochemical, ultrasonographic, pathologic, immunohistochemical and mRNA expression studies were performed. The results showed that oral administration of doxycycline resulted in a significant increase in the thickness of the fibrous cap of the aortic plaque whereas there was a substantial reduction of MMPs expression, local and systemic inflammation, and aortic plaque vulnerability. The incidence of plaque rupture with either treatment (0% for both) was significantly lower than that for controls (56.0%, P<0.05). There was no significant difference between doxycycline-treated group and simvastatin-treated group in any serological, ultrasonographic, pathologic, immunohistochemical and mRNA expression measurement except for the serum lipid levels that were higher with doxycycline than with simvastatin treatment. In conclusion, doxycycline at a common antimicrobial dose stabilizes atherosclerotic lesions via inhibiting matrix metalloproteinases and attenuating inflammation in a rabbit model of vulnerable plaque. These effects were similar to a large dose of simvastatin and independent of serum lipid levels. PMID:22737253

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

PubMed

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

PubMed Central

Wang, Shuang-shuang; Hu, Si-wang; Zhang, Qing-hua; Xia, Ai-xiang

2015-01-01

Background and objectives 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. Subjects and methods 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. Results 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

A novel workflow combining plaque imaging, plaque and plasma proteomics identifies biomarkers of human coronary atherosclerotic plaque disruption.

PubMed

Lee, Regent; Fischer, Roman; Charles, Philip D; Adlam, David; Valli, Alessandro; Di Gleria, Katalin; Kharbanda, Rajesh K; Choudhury, Robin P; Antoniades, Charalambos; Kessler, Benedikt M; Channon, Keith M

2017-01-01

Atherosclerotic plaque rupture is the culprit event which underpins most acute vascular syndromes such as acute myocardial infarction. Novel biomarkers of plaque rupture could improve biological understanding and clinical management of patients presenting with possible acute vascular syndromes but such biomarker(s) remain elusive. Investigation of biomarkers in the context of de novo plaque rupture in humans is confounded by the inability to attribute the plaque rupture as the source of biomarker release, as plaque ruptures are typically associated with prompt down-stream events of myocardial necrosis and systemic inflammation. We developed a novel approach to identify potential biomarkers of plaque rupture by integrating plaque imaging, using optical coherence tomography, with both plaque and plasma proteomic analysis in a human model of angioplasty-induced plaque disruption. We compared two pairs of coronary plaque debris, captured by a FilterWire Device, and their corresponding control samples and found matrix metalloproteinase 9 (MMP9) to be significantly enriched in plaque. Plaque contents, as defined by optical coherence tomography, affect the systemic changes of MMP9. Disruption of lipid-rich plaque led to prompt elevation of plasma MMP9, whereas disruption of non-lipid-rich plaque resulted in delayed elevation of plasma MMP9. Systemic MMP9 elevation is independent of the associated myocardial necrosis and systemic inflammation (measured by Troponin I and C-reactive protein, respectively). This information guided the selection of a subset of subjects of for further label free proteomics analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS). We discovered five novel, plaque-enriched proteins (lipopolysaccharide binding protein, Annexin A5, eukaryotic translocation initiation factor, syntaxin 11, cytochrome B5 reductase 3) to be significantly elevated in systemic circulation at 5 min after plaque disruption. This novel approach for biomarker

Assessment of plaque vulnerability in atherosclerosis via intravascular photoacoustic imaging of targeted liposomal ICG J-aggregates (Conference Presentation)

NASA Astrophysics Data System (ADS)

Harris, Justin T.; Dumani, Diego S.; Cook, Jason R.; Sokolov, Konstantin V.; Emelianov, Stanislav Y.; Homan, Kimberly A.

2017-03-01

While molecular and cellular imaging can be used to visualize the conventional morphology characteristics of vulnerable plaques, there is a need to monitor other physiological factors correlated with high rupture rates; a high M1 activated macrophage concentration is one such indicator of high plaque vulnerability. Here, we present a molecularly targeted contrast agent for intravascular photoacoustic (IVPA) imaging consisting of liposomes loaded with indocyanine green (ICG) J-aggregates with high absorption at 890 nm, allowing for imaging in the presence of blood. This "Lipo-ICG" was targeted to a biomarker of M1 activated macrophages in vulnerable plaques: folate receptor beta (FRβ). The targeted liposomes accumulate in plaques through areas of endothelial dysfunction, while the liposome encapsulation prevents nonspecific interaction with lipids and endothelium. Lipo-ICG specifically interacts with M1 activated macrophages, causing a spectral shift and change in the 890/780 nm photoacoustic intensity ratio upon breakdown of J-aggregates. This sensing mechanism enables assessment of the M1 activated macrophage concentration, providing a measure of plaque vulnerability. In a pilot in vivo study utilizing ApoE deficient mouse models of atherosclerosis, diseased mice showed increased uptake of FRβ targeted Lipo-ICG in the heart and arteries vs. normal mice. Likewise, targeted Lipo-ICG showed increased uptake vs. two non-targeted controls. Thus, we successfully synthesized a contrast agent to detect M1 activated macrophages in high risk atherosclerotic plaques and exhibited targeting both in vitro and in vivo. This biocompatible agent could enable M1 macrophage detection, allowing better clinical decision making in treatment of atherosclerosis.

Molecular imaging of inflammation and intraplaque vasa vasorum: A step forward to identification of vulnerable plaques?

PubMed Central

ten Kate, Gerrit L.; Sijbrands, Eric J. G.; Valkema, Roelf; ten Cate, Folkert J.; Feinstein, Steven B.; van der Steen, Antonius F. W.; Daemen, Mat J. A. P.

2010-01-01

Current developments in cardiovascular biology and imaging enable the noninvasive molecular evaluation of atherosclerotic vascular disease. Intraplaque neovascularization sprouting from the adventitial vasa vasorum has been identified as an independent predictor of intraplaque hemorrhage and plaque rupture. These intraplaque vasa vasorum result from angiogenesis, most likely under influence of hypoxic and inflammatory stimuli. Several molecular imaging techniques are currently available. Most experience has been obtained with molecular imaging using positron emission tomography and single photon emission computed tomography. Recently, the development of targeted contrast agents has allowed molecular imaging with magnetic resonance imaging, ultrasound and computed tomography. The present review discusses the use of these molecular imaging techniques to identify inflammation and intraplaque vasa vasorum to identify vulnerable atherosclerotic plaques at risk of rupture and thrombosis. The available literature on molecular imaging techniques and molecular targets associated with inflammation and angiogenesis is discussed, and the clinical applications of molecular cardiovascular imaging and the use of molecular techniques for local drug delivery are addressed. PMID:20552308

Detection of High-Risk Atherosclerotic Plaque

PubMed Central

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

2013-01-01

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

Near-infrared hyperspectral imaging of atherosclerotic plaque in WHHLMI rabbit artery

NASA Astrophysics Data System (ADS)

Ishii, Katsunori; Kitayabu, Akiko; Omiya, Kota; Honda, Norihiro; Awazu, Kunio

2013-03-01

Hyperspectral imaging (HSI) of rabbit atherosclerotic plaque in near-infrared (NIR) range from 1150 to 2400 nm was demonstrated. A method to identify vulnerable plaques that are likely to cause acute coronary events has been required. The object of this study is identifying vulnerable plaques by NIR-HSI for an angioscopic application. In this study, we observed the hyperspectral images of the atherosclerotic plaque in WHHLMI rabbit (atherosclerotic rabbit) artery under simulated angioscopic conditions by NIR-HSI. NIR-HSI system was constructed by a NIR super continuum light and a mercury-cadmium-telluride camera. Spectral absorbance values (log (1/R) data) were obtained in the wavelength range from 1150 to 2400 nm at 10 nm intervals. The hyperspectral images were constructed with spectral angle mapper algorithm. As a result, the detections of atherosclerotic plaque under angioscopic observation conditions were achieved especially in the wavelength around 1200 nm, which corresponds to the second overtone of CH stretching vibration mode. The NIR-HSI was considered to serve as an angioscopic diagnosis technique to identify vulnerable plaques without clamping and saline injection.

Spatio-temporal texture (SpTeT) for distinguishing vulnerable from stable atherosclerotic plaque on dynamic contrast enhancement (DCE) MRI in a rabbit model

PubMed Central

Wan, Tao; Madabhushi, Anant; Phinikaridou, Alkystis; Hamilton, James A.; Hua, Ning; Pham, Tuan; Danagoulian, Jovanna; Kleiman, Ross; Buckler, Andrew J.

2014-01-01

Purpose: To develop a new spatio-temporal texture (SpTeT) based method for distinguishing vulnerable versus stable atherosclerotic plaques on DCE-MRI using a rabbit model of atherothrombosis. Methods: Aortic atherosclerosis was induced in 20 New Zealand White rabbits by cholesterol diet and endothelial denudation. MRI was performed before (pretrigger) and after (posttrigger) inducing plaque disruption with Russell's-viper-venom and histamine. Of the 30 vascular targets (segments) under histology analysis, 16 contained thrombus (vulnerable) and 14 did not (stable). A total of 352 voxel-wise computerized SpTeT features, including 192 Gabor, 36 Kirsch, 12 Sobel, 52 Haralick, and 60 first-order textural features, were extracted on DCE-MRI to capture subtle texture changes in the plaques over the course of contrast uptake. Different combinations of SpTeT feature sets, in which the features were ranked by a minimum-redundancy-maximum-relevance feature selection technique, were evaluated via a random forest classifier. A 500 iterative 2-fold cross validation was performed for discriminating the vulnerable atherosclerotic plaque and stable atherosclerotic plaque on per voxel basis. Four quantitative metrics were utilized to measure the classification results in separating between vulnerable and stable plaques. Results: The quantitative results show that the combination of five classes of SpTeT features can distinguish between vulnerable (disrupted plaques with an overlying thrombus) and stable plaques with the best AUC values of 0.9631 ± 0.0088, accuracy of 89.98% ± 0.57%, sensitivity of 83.71% ± 1.71%, and specificity of 94.55% ± 0.48%. Conclusions: Vulnerable and stable plaque can be distinguished by SpTeT based features. The SpTeT features, following validation on larger datasets, could be established as effective and reliable imaging biomarkers for noninvasively assessing atherosclerotic risk. PMID:24694153

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

PubMed Central

Pedersen, Sune F; Hag, Anne Mette F; Klausen, Thomas L; Ripa, Rasmus S; Bodholdt, Rasmus P; Kjær, Andreas

2014-01-01

Atherosclerosis is the primary underlying cause of cardiovascular disease (CVD). It is the leading cause of morbidity and mortality in the Western world today and is set to become the prevailing disease and major cause of death worldwide by 2020. In the 1950s surgical intervention was introduced to treat symptomatic patients with high-grade carotid artery stenosis due to atherosclerosis – a procedure known as carotid endarterectomy (CEA). By removing the atherosclerotic plaque from the affected carotid artery of these patients, CEA is beneficial by preventing subsequent ipsilateral ischemic stroke. However, it is known that patients with low to intermediate artery stenosis may still experience ischemic events, leading clinicians to consider plaque composition as an important feature of atherosclerosis. Today molecular imaging can be used for characterization, visualization and quantification of cellular and subcellular physiological processes as they take place in vivo; using this technology we can obtain valuable information on atherosclerostic plaque composition. Applying molecular imaging clinically to atherosclerotic disease therefore has the potential to identify atherosclerotic plaques vulnerable to rupture. This could prove to be an important tool for the selection of patients for CEA surgery in a health system increasingly focused on individualized treatment. This review focuses on current advances and future developments of in vivo atherosclerosis PET imaging in man. PMID:24289282

Atherosclerotic plaque characterization by spatial and temporal speckle pattern analysis

NASA Astrophysics Data System (ADS)

Tearney, Guillermo J.; Bouma, Brett E.

2002-04-01

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

Relationship between thin cap fibroatheroma identified by virtual histology and angioscopic yellow plaque in quantitative analysis with colorimetry.

PubMed

Yamamoto, Masanori; Takano, Masamichi; Okamatsu, Kentaro; Murakami, Daisuke; Inami, Shigenobu; Xie, Yong; Seimiya, Koji; Ohba, Takayoshi; Seino, Yoshihiko; Mizuno, Kyoichi

2009-03-01

Thin cap fibroatheroma (TCFA) is considered to be a vulnerable plaque. Virtual Histology-intravascular ultrasound (VH-IVUS) can precisely identify TCFA in vivo. Intense yellow plaque on angioscopy determined by quantitative colorimetry with L a b color space corresponds with histological TCFA; in particular, a plaque of color b value >23 indicates an atheroma with a fibrous cap thickness <100 mum. In the present study, the relationship between VH-TCFA and angioscopic plaque color determined by colorimetry was investigated. Fifty-seven culprit plaques in 57 patients were evaluated by VH-IVUS and angioscopy. VH-TCFA was defined as a plaque with a necrotic core >10% of plaque area without overlying fibrous tissue, and angioscopic TCFA was a plaque with b value >23. The frequency of angioscopic TCFA was higher in the VH-TCFA group than in the VH-non-TCFA group (74% vs 23%, P=0.0002). Moreover, yellow color intensity (b value) significantly correlated with plaque classification on VH-IVUS. When TCFA detected with angioscopy was used as the gold standard, the sensitivity, specificity, and accuracy for TCFA with VH-IVUS was 68%, 81%, and 75%, respectively. VH-TCFA strongly correlated with angioscopic TCFA determined by a quantitative analysis with colorimetry.

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

PubMed Central

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

2008-01-01

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 μm) and presumably stable plaques, in which fibrous caps were thicker than 100 μm. 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 μm2 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

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

PubMed

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

[Association of human epicardial adipose tissue volume and inflammatory mediators with atherosclerosis and vulnerable coronary atherosclerotic plaque].

PubMed

Zhou, Liangliang; Gong, Jianbin; Li, Demin; Lu, Guangming; Chen, Dong; Wang, Jing

2015-02-01

To investigate the relation of epicardial adipose tissue volume (EATV) determined by dual-source CT (DSCT) cardiac angiography and EAT-derived inflammatory factors to coronary heart disease (CHD) and vulnerable plaque. A total of 260 patients underwent cardiac computed tomography to evaluate stenosis of coronary artery, and blood samples were obtained from each patient. CHD was confirmed in 180 patients by DSA and CHD was excluded in the remaining 80 patients (NCHD). Vascular remodeling index and plaque vulnerability parameters (fatty volume, fibrous volume and calcification volume and fiber volume) were measured in CHD patients and correlation with EATV was analyzed. Epicardial adipose tissue (EAT) and intrathoracic adipose tissue (TAT) were collected from 40 CHD patients undergoing CABG surgery, and, mRNA and protein expressions of leptin and MMP9 were detected by RT-PCR and Western blot analysis. (1) The EATV was significantly higher in the CHD group than in NCHD group ((121.2 ± 40.6) mm³ vs. (74.7 ± 18.1) mm³, P = 0.01). (2) Subgroup analysis of the CHD patients demonstrated that EATV was significantly higher in patients with positive remodeling than in patients without positive remodeling ((97.6 ± 42.0) cm³ vs. (75.5 ± 25.4) cm³, P = 0.01). Lipid plaque volume was positively correlated with EATV (r = 0.34, P = 0.002); however, fiber plaque volume was negatively correlated with EATV (r = -0.30, P = 0.008). (3) Logistic regression analysis indicated that EATV was an independent risk factor for positive vascular remodeling (OR = 2.01, 95% CI: 1.30-2.32, P = 0.01). (4) mRNA and protein expression of leptin and MMP9 in EAT was significantly upregulated in 40 CHD patients who received CABG surgery compared to 40 NCHD patients (P < 0.01). However, there was no significant difference (P > 0.05) in mRNA and protein expression of leptin and MMP9 from the SAT between CHD and NCHD patients. (5) In the CHD group, leptin and MMP9 levels in EAT and EATV were

Surface modified gold nanoparticles for SERS based detection of vulnerable plaque formations (Conference Presentation)

NASA Astrophysics Data System (ADS)

Matthäus, Christian; Dugandžić, Vera; Weber, Karina; Cialla-May, Dana; Popp, Jürgen

2017-02-01

Cardiovascular diseases are the leading cause of death worldwide. Atherosclerosis is closely related to the majority of these diseases, as a process of thickening and stiffening of the arterial walls through accumulation of lipids, which is a consequence of aging and life style. Atherosclerosis affects all people in some extent, but not all arterial plaques will necessarily lead to the complications, such as thrombosis, stroke and heart attack. One of the greatest challenges in the risk assessment of atherosclerotic depositions is the detection and recognition of plaques which are unstable and prone to rupture. These vulnerable plaques usually consist of a lipid core that attracts macrophages, a type of white blood cells that are responsible for the degradation of lipids. It has been hypothesized that the amount of macrophages relates to the overall plaque stability. As phagocytes, macrophages also act as recipients for nanoscale particles or structures. Administered gold nanoparticles are usually rabidly taken up by macrophages residing within arterial walls and can therefore be indirectly detected. A very sensitive strategy for probing gold nanoparticles is by utilizing surface enhanced Raman scattering (SERS). By modifying the surface of these particles with SERS active labels it is possible to generate highly specific signals that exhibit sensitivity comparable to fluorescence. SERS labeled gold nanoparticles have been synthesized and the uptake dynamics and efficiency on macrophages in cell cultures was investigated using Raman microscopic imaging. The results clearly show that nanoparticles are taken up by macrophages and support the potential of SERS spectroscopy for the detection of vulnerable plaques. Acknowledgements: Financial support from the Carl Zeiss Foundation is highly acknowledged. The project "Jenaer Biochip Initiative 2.0" (03IPT513Y) within the framework "InnoProfile Transfer - Unternehmen Region" is supported by the Federal Ministry of

Atherosclerotic plaque in the left carotid artery is more vulnerable than in the right.

PubMed

Selwaness, Mariana; van den Bouwhuijsen, Quirijn; van Onkelen, Robbert S; Hofman, Albert; Franco, Oscar H; van der Lugt, Aad; Wentzel, Jolanda J; Vernooij, Meike

2014-11-01

Ischemic stroke is more often diagnosed in the left hemisphere than in the right. It is unknown whether this asymmetrical prevalence relates to differences in carotid atherosclerosis. We compared atherosclerotic plaque prevalence, severity, and composition between left and right carotid arteries. In a population-based cohort, carotid MRI scanning was performed in 1414 stroke-free participants (≥45 years). Using a multisequence MRI protocol, we assessed the prevalence, stenosis, and thickness of the plaque and its predominant component (ie, lipid core, intraplaque hemorrhage, calcification, or fibrous tissue in each carotid artery). Differences between left and right side were tested using paired t tests, McNemar test and Generalized Estimating Equation analyses. The majority (85%) of the participants had bilateral carotid plaques. Unilateral plaques were twice more prevalent on the left than on the right side (67% versus 33%; P<0.001). Plaque thickness was also greater on the left (3.1±1.2 versus 2.9±1.3 mm; P<0.001); degree of stenosis did not differ. Intraplaque hemorrhage and fibrous tissue were more prevalent on the left (9.1 versus 5.9%; P<0.001 and 45.0 versus 38.5%; P<0.001), whereas calcification occurred more often on the right (37.4 versus 31.6% at the left; P<0.001). Lipid was equally distributed. Carotid atherosclerotic plaque size and composition are not symmetrically distributed. Predominance of intraplaque hemorrhage in left-sided carotid plaques suggests a greater vulnerability as opposed to right-sided plaques, which are more calcified and therefore considered more stable. © 2014 American Heart Association, Inc.

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.

PubMed

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 (p<0.001 for both). Multivariate analyses revealed that a combined presence of AVC and MAC was independently associated with the presence (odds ratio [OR] 9.36, 95% confidence interval [95%CI] 1.55-56.53, p=0.015) and extent (β-estimate 1.86, p<0.001) of overall coronary plaque. When stratified by plaque composition, it was associated with the extent of CAP (β-estimate 1.77, p<0.001) and MCAP (β-estimate 1.04, p<0.001), but not with NCAP. 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.

Circulating Immunoglobulins Are Not Associated with Intraplaque Mast Cell Number and Other Vulnerable Plaque Characteristics in Patients with Carotid Artery Stenosis

PubMed Central

Quax, Paul H. A.; de Borst, Gert Jan; de Vries, Jean-Paul P. M.; Moll, Frans L.; Kuiper, Johan; Toes, René E. M.; de Jager, Saskia C. A.; de Kleijn, Dominique P. V.; Hoefer, Imo E.; Pasterkamp, Gerard; Bot, Ilze

2014-01-01

Background Recently, we have shown that intraplaque mast cell numbers are associated with atherosclerotic plaque vulnerability and with future cardiovascular events, which renders inhibition of mast cell activation of interest for future therapeutic interventions. However, the endogenous triggers that activate mast cells during the progression and destabilization of atherosclerotic lesions remain unidentified. Mast cells can be activated by immunoglobulins and in the present study, we aimed to establish whether specific immunoglobulins in plasma of patients scheduled for carotid endarterectomy were related to (activated) intraplaque mast cell numbers and plasma tryptase levels. In addition, the levels were related to other vulnerable plaque characteristics and baseline clinical data. Methods and Results OxLDL-IgG, total IgG and total IgE levels were measured in 135 patients who underwent carotid endarterectomy. No associations were observed between the tested plasma immunoglobulin levels and total mast cell numbers in atherosclerotic plaques. Furthermore, no associations were found between IgG levels and the following plaque characteristics: lipid core size, degree of calcification, number of macrophages or smooth muscle cells, amount of collagen and number of microvessels. Interestingly, statin use was negatively associated with plasma IgE and oxLDL-IgG levels. Conclusions In patients suffering from carotid artery disease, total IgE, total IgG and oxLDL-IgG levels do not associate with plaque mast cell numbers or other vulnerable plaque histopathological characteristics. This study thus does not provide evidence that the immunoglobulins tested in our cohort play a role in intraplaque mast cell activation or grade of atherosclerosis. PMID:24586471

Tanshinone II A stabilizes vulnerable plaques by suppressing RAGE signaling and NF-κB activation in apolipoprotein-E-deficient mice

PubMed Central

Zhao, Dong; Tong, Lufang; Zhang, Lixin; Li, Hong; Wan, Yingxin; Zhang, Tiezhong

2016-01-01

Tanshinone II A (TSIIA) is a diterpene quinone extracted from the roots of Salvia miltiorrhiza with anti-inflammatory and anti-oxidant properties that is used to treat atherosclerosis. In the current study, morphological analyses were conducted to evaluate the effects of TSIIA on atherosclerotic vulnerable plaque stability. Additionally, receptor of advanced glycation end products (RAGE), adhesion molecule, and matrix-metalloproteinases (MMPs) expression, and nuclear factor-κB (NF-κB) activation were examined in apolipoprotein E (apoE)-deficient mice treated with TSIIA. Eight-week-old apoE−/− mice were administered TSIIA and fed an atherogenic diet for 8 weeks. TSIIA exhibited no effects on plaque size. Analysis of the vulnerable plaque composition demonstrated decreased numbers of macrophages and smooth muscle cells, and increased collagen content in apoE-deficient mice treated with TSIIA compared with untreated mice. Western blotting revealed that TSIIA downregulated the expression levels of vascular cellular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and MMP-2, −3, and −9, suppressed RAGE, and inhibited NF-κB, JNK and p38 activation. The present study demonstrated that the underlying mechanism of TSIIA stabilization of vulnerable plaques involves interfering with RAGE and NF-κB activation, and downregulation of downstream inflammatory factors, including ICAM-1, VCAM-1, and MMP-2, −3 and −9 in apoE−/− mice. PMID:27840935

Novel 3D-CT evaluation of carotid stent volume: greater chronological expansion of stents in patients with vulnerable plaques.

PubMed

Itami, Hisakazu; Tokunaga, Koji; Okuma, Yu; Hishikawa, Tomohito; Sugiu, Kenji; Ida, Kentaro; Date, Isao

2013-09-01

Although self-expanding carotid stents may dilate gradually, the degrees of residual stenosis have been quantified by the NASCET criteria, which is too simple to reflect the configuration of the stented artery. We measured the volumes of the stent lumens chronologically by 3D-CT in patients after carotid artery stenting (CAS), and analyzed the correlations between the volume change and medical factors. Fourteen patients with carotid artery stenosis were treated using self-expanding, open-cell stents. All patients underwent preoperative plaque MRI (magnetization-prepared rapid acquisition gradient-echo, MPRAGE) and chronological 3D-CT examinations of their stents immediately after their placement and 1 day, 1 week, and 1 month after the procedure. The volume of the stent lumen was measured using a 3D workstation. The correlations between stent volume and various factors including the presence of underlying diseases, plaque characteristics, and the results of the CAS procedure were analyzed. Stent volume gradually increased in each case and had increased by 1.04-1.55 (mean, 1.25)-fold at 1 postoperative month. The presence of underlying medical diseases, plaque length, the degree of residual stenosis immediately after CAS, and plaque calcification did not have an impact on the change in stent volume. On the other hand, the stent volume increase was significantly larger in the patients with vulnerable plaques that demonstrated high MPRAGE signal intensity (P < 0.05). A 3D-CT examination is useful for precisely measuring stent volume. Self-expanding stents in carotid arteries containing vulnerable plaques expand significantly more than those without such plaques in a follow-up period.

Apoptosis of vascular smooth muscle cells induces features of plaque vulnerability in atherosclerosis.

PubMed

Clarke, Murray C H; Figg, Nichola; Maguire, Janet J; Davenport, Anthony P; Goddard, Martin; Littlewood, Trevor D; Bennett, Martin R

2006-09-01

Vascular smooth muscle cell (VSMC) apoptosis occurs in many arterial diseases, including aneurysm formation, angioplasty restenosis and atherosclerosis. Although VSMC apoptosis promotes vessel remodeling, coagulation and inflammation, its precise contribution to these diseases is unknown, given that apoptosis frequently accompanies vessel injury or alterations to flow. To study the direct consequences of VSMC apoptosis, we generated transgenic mice expressing the human diphtheria toxin receptor (hDTR, encoded by HBEGF) from a minimal Tagln (also known as SM22alpha) promoter. Despite apoptosis inducing loss of 50-70% of VSMCs, normal arteries showed no inflammation, reactive proliferation, thrombosis, remodeling or aneurysm formation. In contrast, VSMC apoptosis in atherosclerotic plaques of SM22alpha-hDTR Apoe-/- mice induced marked thinning of fibrous cap, loss of collagen and matrix, accumulation of cell debris and intense intimal inflammation. We conclude that VSMC apoptosis is 'silent' in normal arteries, which have a large capacity to withstand cell loss. In contrast, VSMC apoptosis alone is sufficient to induce features of plaque vulnerability in atherosclerosis. SM22alpha-hDTR Apoe-/- mice may represent an important new model to test agents proposed to stabilize atherosclerotic plaques.

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

NASA Astrophysics Data System (ADS)

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

2014-09-01

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

Progress in atherosclerotic plaque imaging

PubMed Central

Soloperto, Giulia; Casciaro, Sergio

2012-01-01

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

Assessment of serum leptin, pregnancy-associated plasma protein A and CRP levels as indicators of plaque vulnerability in patients with acute coronary syndrome.

PubMed

Lodh, Moushumi; Goswami, Binita; Parida, Ashok; Patra, Surajeet; Saxena, Alpana

2012-07-01

A multifactorial aetiology of coronary artery disease (CAD) has been established in the recent past. Extensive research is now underway to understand the mechanisms responsible for plaque vulnerability. The identification of a novel biomarker that will help in the assessment of plaque status is urgently needed for the purpose of patient stratification and prognostication. The aim of the present study was to evaluate leptin, pregnancy-associated plasma protein A (PAPP-A) and C-reactive protein (CRP) levels in patients with acute coronary syndrome and to assess their diagnostic efficacy in the identification of vulnerable plaques. The study group comprised 105 patients who had chest pain along with ECG changes (ST elevation, ST depression, T inversion) and raised cardiac enzyme levels. Sixty-two patients with chest pain and ECG changes but with normal cardiac enzyme profiles were included in the control group. Lipid profiles, and leptin, PAPP-A and CRP levels were assessed in these two groups. Receiver operating characteristics (ROC) curves were plotted to determine the utility of the parameters under study as markers of plaque vulnerability. Significantly higher levels of serum lipoprotein (a), leptin, PAPP-A and high-sensitivity CRP (hs-CRP) were observed in the cases than in the controls. A positive correlation was observed between CRP and PAPP-A levels as well as CRP and leptin concentrations. ROC curve analysis revealed similar efficacies of CRP and PAPP-A levels in their ability to detect unstable plaques with areas under the curve of 0.762 and 0.732, respectively. Multivariate analysis established the superiority of hs-CRP as a predictor of plaque instability. Our study highlights the utility of both CRP and PAPP-A levels as determinants of plaque instability. Our findings necessitate population-based follow-up studies to establish the superiority of either of the two biomarkers in the field of preventive cardiology.

Vulnerable Atherosclerotic Plaque Elasticity Reconstruction Based on a Segmentation-Driven Optimization Procedure Using Strain Measurements: Theoretical Framework

PubMed Central

Le Floc’h, Simon; Tracqui, Philippe; Finet, Gérard; Gharib, Ahmed M.; Maurice, Roch L.; Cloutier, Guy; Pettigrew, Roderic I.

2016-01-01

It is now recognized that prediction of the vulnerable coronary plaque rupture requires not only an accurate quantification of fibrous cap thickness and necrotic core morphology but also a precise knowledge of the mechanical properties of plaque components. Indeed, such knowledge would allow a precise evaluation of the peak cap-stress amplitude, which is known to be a good biomechanical predictor of plaque rupture. Several studies have been performed to reconstruct a Young’s modulus map from strain elastograms. It seems that the main issue for improving such methods does not rely on the optimization algorithm itself, but rather on preconditioning requiring the best estimation of the plaque components’ contours. The present theoretical study was therefore designed to develop: 1) a preconditioning model to extract the plaque morphology in order to initiate the optimization process, and 2) an approach combining a dynamic segmentation method with an optimization procedure to highlight the modulogram of the atherosclerotic plaque. This methodology, based on the continuum mechanics theory prescribing the strain field, was successfully applied to seven intravascular ultrasound coronary lesion morphologies. The reconstructed cap thickness, necrotic core area, calcium area, and the Young’s moduli of the calcium, necrotic core, and fibrosis were obtained with mean relative errors of 12%, 4% and 1%, 43%, 32%, and 2%, respectively. PMID:19164080

Absence of Akt1 reduces vascular smooth muscle cell migration and survival and induces features of plaque vulnerability and cardiac dysfunction during atherosclerosis

PubMed Central

Fernández-Hernando, Carlos; József, Levente; Jenkins, Deborah; Lorenzo, Annarita Di; Sessa, William C.

2009-01-01

Objective Deletion of Akt1 leads to severe atherosclerosis and occlusive coronary artery disease. VSMC are an important component of atherosclerotic plaques, responsible for promoting plaque stability in advanced lesions. Fibrous caps of unstable plaques contain less collagen and ECM components and fewer VSMCs than caps from stable lesions. Here, we investigated the role of Akt1 in VSMC proliferation, migration and oxidative stress-induce apoptosis. In addition, we also characterized the atherosclerotic plaque morphology and cardiac function in an atherosclerosis-prone mouse model deficient in Akt1. Methods and Results Absence of Akt1 reduces VSMC proliferation and migration. Mechanistically, the proliferation and migratory phenotype found in Akt1 null VSMCs was linked to reduced Rac-1 activity and MMP-2 secretion. Serum starvation and stress-induced apoptosis was enhanced in Akt1 null VSMCs as determined by flow cytometry using Annexin V/PI staining. Immunohistochemical analysis of atherosclerotic plaques from Akt1−/−ApoE−/− mice showed a dramatic increase in plaque vulnerability characteristics such as enlarged necrotic core and reduced fibrous cap and collagen content. Finally, we show evidences of myocardial infarcts and cardiac dysfunction in Akt1−/−ApoE−/− mice analyzed by immunohistochemistry and echocardiography respectively. Conclusion Akt1 is essential for VSMC proliferation, migration and protection against oxidative stress-induce apoptosis. Absence of Akt1 induces features of plaque vulnerability and cardiac dysfunction in a mouse model of atherosclerosis. PMID:19762778

Vulnerable atherosclerotic plaque morphology in apolipoprotein E-deficient mice unable to make ascorbic Acid.

PubMed

Nakata, Yukiko; Maeda, Nobuyo

2002-03-26

Oxidative stress is thought to play an important role in atherogenesis, suggesting that antioxidants could prevent coronary artery disease. However, the efficacy of vitamin C in reducing atherosclerosis is debatable in humans and has not been tested rigorously in animals. Gulo(-/-)Apoe(-/-) mice were used to test a hypothesis that chronic vitamin C deficiency enhances the initiation and development of atherosclerosis. These mice are dependent on dietary vitamin C because of the lack of L-gulonolactone-gamma-oxidase and are prone to develop atherosclerosis because of lacking apolipoprotein E. Beginning at 6 weeks of age, the Gulo(-/-)Apoe(-/-) mice were fed regular chow or Western-type diets containing high fat and supplemented with either 0.033 g or 3.3 g/L of vitamin C in their drinking water. This regimen produced mice with chronically low vitamin C (average 1.5 microg/mL in plasma) or high vitamin C (average 10 to 30 microg/mL in plasma). Morphometric analysis showed that within each sex, age, and diet group, the sizes of the atherosclerotic plaques were not different between low vitamin C mice and high vitamin C mice. However, advanced plaques in the low vitamin C mice had significantly reduced amounts of Sirius red-staining collagen (36.4+/-2.2% versus 54.8+/-2.3%, P<0.0001), larger necrotic cores within the plaques, and reduced fibroproliferation and neovascularization in the aortic adventitia. Chronic vitamin C deficiency does not influence the initiation or progression of atherosclerotic plaques but severely compromises collagen deposition and induces a type of plaque morphology that is potentially vulnerable to rupture.

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

PubMed

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.

Biomechanics of Atherosclerotic Coronary Plaque: Site, Stability and In Vivo Elasticity Modeling

PubMed Central

Ohayon, Jacques; Finet, Gérard; Le Floc’h, Simon; Cloutier, Guy; Gharib, Ahmed M.; Heroux, Julie; Pettigrew, Roderic I.

2016-01-01

Coronary atheroma develop in local sites that are widely variable among patients and are considerably variable in their vulnerability for rupture. This article summarizes studies conducted by our collaborative laboratories on predictive biomechanical modeling of coronary plaques. It aims to give insights into the role of biomechanics in the development and localization of atherosclerosis, the morphologic features that determine vulnerable plaque stability, and emerging in vivo imaging techniques that may detect and characterize vulnerable plaque. Composite biomechanical and hemodynamic factors that influence the actual site of development of plaques have been studied. Plaque vulnerability, in vivo, is more challenging to assess. Important steps have been made in defining the biomechanical factors that are predictive of plaque rupture and the likelihood of this occurring if characteristic features are known. A critical key in defining plaque vulnerability is the accurate quantification of both the morphology and the mechanical properties of the diseased arteries. Recently, an early IVUS based palpography technique developed to assess local strain, elasticity and mechanical instabilities has been successfully revisited and improved to account for complex plaque geometries. This is based on an initial best estimation of the plaque components’ contours, allowing subsequent iteration for elastic modulus assessment as a basis for plaque stability determination. The improved method has also been preliminarily evaluated in patients with successful histologic correlation. Further clinical evaluation and refinement are on the horizon. PMID:24043605

TRAF3IP2 mediates atherosclerotic plaque development and vulnerability in ApoE−/− mice

PubMed Central

Prasad, Sakamuri Siva Sankara Vara; Higashi, Yusuke; Sukhanov, Sergiy; Siddesha, Jalahalli M; Delafontaine, Patrice; Siebenlist, Ulrich; Chandrasekar, Bysani

2016-01-01

Background and aims Atherosclerosis is a major cause of heart attack and stroke. Inflammation plays a critical role in the development of atherosclerosis. Since the cytoplasmic adaptor molecule TRAF3IP2 (TRAF3-Interacting Protein 2) plays a causal role in various autoimmune and inflammatory diseases, we hypothesized that TRAF3IP2 mediates atherosclerotic plaque development. Methods TRAF3IP2/ApoE double knockout (DKO) mice were generated by crossing TRAF3IP2−/− and ApoE−/− mice. ApoE−/− mice served as controls. Both DKO and control mice were fed a high-fat diet for 12 weeks. Plasma lipids were measured by ELISA, atherosclerosis by en face analysis of aorta and plaque cross-section measurements at the aortic valve region, plaque necrotic core area, collagen and smooth muscle cell content by histomorphometry, and aortic gene expression by RT-qPCR. Results The plasma lipoprotein profile was not altered by TRAF3IP2 gene deletion in ApoE−/− mice. While total aortic plaque area was decreased in DKO female, but not male mice, the plaque necrotic area was significantly decreased in DKO mice of both genders. Plaque collagen and smooth muscle cell contents were increased significantly in both female and male DKO mice compared to respective controls. Aortic expression of proinflammatory cytokine (Tumor necrosis factor α, TNFα), chemokine (Chemokine (C-X-C motif) Ligand 1, CXCL1) and adhesion molecule (Vascular cell adhesion molecule 1, VCAM1; and Intercellular adhesion molecule 1, ICAM1) gene expression were decreased in both male and female DKO mice. In addition, the male DKO mice showed a markedly reduced expression of extracellular matrix (ECM)-related genes, including TIMP1 (Tissue inhibitor of metalloproteinase 1), RECK (Reversion-Inducing- Cysteine-Rich Protein with Kazal Motifs) and ADAM17 (A Disintegrin And Metalloproteinase 17). Conclusions TRAF3IP2 plays a causal role in atherosclerotic plaque development and vulnerability, possibly by inducing the

Risk classification of highly sensitive troponin I predict presence of vulnerable plaque assessed by dual source coronary computed tomography angiography.

PubMed

Liu, Ting; Wang, Guan; Li, Peiling; Dai, Xu

2017-11-01

Patients presenting to the emergency department with acute chest pain, negative conventional troponin and electrocardiogram require serial testing to rule out acute coronary syndrome (ACS). We studied the association of highly sensitive troponin (hsTn) I with vulnerable plaque features as detected by coronary dual source computed tomography angiography (DSCTA) and determined whether hsTn I at the time of presentation combined with early DSCTA could improve classification of patients as high-risk or low risk for ACS. We included 220 patients with acute chest pain, negative electrocardiogram and conventional troponin who underwent DSCTA and had hsTn I measured at the time of presentation. The patients were categorized as having hsTn I below the limit of detection (low risk), intermediate and above the 99th percentile (high risk). Readers assessed DSCTA qualitatively for the presence of significant CAD (≥50% stenosis), calcified and non-calcified coronary plaque, and vulnerable plaque features (positive remodeling, low CT attenuation plaque, napkin-ring sign, spotty calcium). The mean age of the population was 50.3 ± 8.2 years (43% women). ACS during the index hospitalization occurred in 36 (16.3%) patients (myocardial infarction n = 8, unstable angina pectoris n = 28). HsTn I was below the limit of detection, intermediate, and above 99th percentile in 39 (17.7%), 139 (86.9%), and 42 (19.1%) patients, respectively. Across the categories of low risk, intermediate and high risk of hsTn I, there was increase in prevalence of ≥50% stenosis (0, 11.5, and 61.9% of patients; p < 0.001), any plaque (35.9, 51.1, and 85.7% of patients; p < 0.001) and high-risk plaque (0, 36.0, and 85.7% of patients; p < 0.001). None of the patients in low risk HsTn I group had ACS. ACS occurred in 10.1% of the intermediate hsTn I group and in 52.3% of the patients with high risk hsTnI group. Severity of stenosis and presence of vunerable plaque as detected by DSCTA

High-Risk Carotid Plaques Identified by CT-Angiogram can Predict Acute Myocardial Infarction

PubMed Central

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

2016-01-01

Purpose 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. Methods 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 (NRS). Adjusted relative risks were calculated for each plaque features. Results Patients with speckled (<3mm) calcifications and/or larger calcifications on CTA had a higher risk of developing an MI and/or obstructive CAD within one year compared to patients without [adjusted RR of 7.51, 95%CI 1.26 to 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 one year than patients without [adjusted RR of 2.73, 95%CI 1.19 to 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. Conclusions 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. PMID:27866279

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

PubMed

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.

High-resolution magnetic resonance imaging of carotid atherosclerotic plaques - a correlation study with histopathology.

PubMed

Xia, Zhangyong; Yang, Hua; Yuan, Xiaochun; Wang, Jiyue; Zhang, Shigang; Zhang, Liyong; Qu, Yang; Chen, Jun; Jiao, Liqun; Wang, Le-Xin; Du, Yifeng

2017-07-01

This study aimed to utilize high-resolution magnetic resonance imaging (MRI) to investigate the characteristics of stable and vulnerable carotid arteriosclerotic plaques, with correlations to histopathological findings. High-resolution MRI was performed in 817 patients, using three-dimensional magnetic resonance angiography. Plaque composition was evaluated by measuring the areas occupied by calcification, a lipid-rich necrotic core, intra-plaque haemorrhage, and fibrous cap rupture. Plaque morphology was analysed by measuring vessel wall area, thickness, and luminal area at the bifurcation of the common carotid artery. Plaque tissues were sampled during carotid endarterectomy and examined using haematoxylin-eosin, Oil Red O, Masson trichrome staining, and immunohistochemical staining for CD68. Patients were divided into stable plaque group (n = 462) and vulnerable plaque group (n = 355), based on intraoperative observations and postoperative histopathological findings. Compared to the stable plaque group, the vulnerable plaque group exhibited increased vessel wall areas and thickness, and decreased mean luminal areas (P < 0.001). The vulnerable plaque group also had a lower collagen content, a higher lipid content, and higher CD68 expression in plaque tissues on histological examinations (P < 0.01). Incidences of lipid-rich necrotic core (38.1 % vs. 34.3 %), intra-plaque haemorrhage (26.9 % vs. 22.8 %), plaque calcification (45.2 % vs. 40.9 %), and fibrous cap rupture (36.0 % vs 39.8 %) in the plaques were concordant with MRI observations and histopathological findings (p > 0.05). Stable and vulnerable carotid plaques had different morphologies and compositions. High-resolution MRI can assess such differences qualitatively and quantitatively in vivo and provide guidance for risk stratification and management.

Catheter design optimization for practical intravascular photoacoustic imaging (IVPA) of vulnerable plaques

NASA Astrophysics Data System (ADS)

Iskander-Rizk, Sophinese; Wu, Min; Springeling, Geert; Mastik, Frits; Beurskens, Robert H. S. H.; van der Steen, Antonius F. W.; van Soest, Gijs

2018-02-01

Intravascular photoacoustic/ultrasound imaging (IVPA/US) can image the structure and composition of atherosclerotic lesions identifying lipid-rich plaques ex vivo and in vivo. In the literature, multiple IVPA/US catheter designs were presented and validated both in ex-vivo models and preclinical in-vivo situations. Since the catheter is a critical component of the imaging system, we discuss here a catheter design oriented to imaging plaque in a realistic and translatable setting. We present a catheter optimized for light delivery, manageable flush parameters and robustness with reduced mechanical damage risks at the laser/catheter joint interface. We also show capability of imaging within sheath and in water medium.

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

PubMed

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

Decreased cathepsin K levels in human atherosclerotic plaques are associated with plaque instability.

PubMed

Zhao, Huiying; Qin, Xiujiao; Wang, Shuai; Sun, Xiwei; Dong, Bin

2017-10-01

Investigating the determinants and dynamics of atherosclerotic plaque instability is a key area of current cardiovascular research. Extracellular matrix degradation from excessive proteolysis induced by enzymes such as cathepsin K (Cat K) is implicated in the pathogenesis of unstable plaques. The current study assessed the expression of Cat K in human unstable atherosclerotic plaques. Specimens of popliteal arteries with atherosclerotic plaques were classified as stable (<40% lipid core plaque area; n=6) or unstable (≥40% lipid core plaque area; n=14) based on histopathological examinations of hematoxylin and eosin stained sections. The expression of Cat K and cystatin C (Cys C) were assessed by immunohistochemical examination and levels of Cat K mRNA were detected by semi-quantitative reverse transcriptase polymerase chain reaction. Morphological changes including a larger lipid core, endothelial proliferation with foam cells and destruction of internal elastic lamina were observed in unstable atherosclerotic plaques. In unstable plaques, the expression of Cat K protein and mRNA was upregulated, whereas Cys C protein expression was downregulated. The interplay between Cat K and Cys C may underlie the progression of plaques from stable to unstable and the current study indicated that Cat K and Cys C are potential targets for preventing and treating vulnerable atherosclerotic plaque ruptures.

Aortic atherosclerotic plaque detection using a multiwavelength handheld photoacoustic imaging system

NASA Astrophysics Data System (ADS)

Hirano, Susumu; Namita, Takeshi; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

2016-03-01

Patients affected by diseases caused by arteriosclerosis are increasing. Atherosclerosis, which is becoming an especially difficult health problem, forms plaques from lipids such as cholesterol located in walls of the aorta, cerebral artery, and coronary artery. Because lipid-rich plaques are vulnerable and because arterial rupture causes acute vascular occlusion, early detection is crucially important to prevent plaque growth and rupture. Ultrasound systems can detect plaques but cannot discriminate between vulnerable and equable plaques. To evaluate plaques non-invasively and easily, we developed a handheld photoacoustic imaging device. Its usefulness was verified in phantom experiments with a bovine aorta in which mimic plaque had been embedded. Photoacoustic images taken at wavelengths that produce high light absorbance by lipids show strong photoacoustic signals from the boundary of the mimic plaque. Results confirmed that our system can evaluate plaque properties by analysis with the photoacoustic spectrum. The effects of surrounding tissues and tissue components on plaque evaluation were investigated using a layered phantom. The mimic plaque located under a 6 mm blood layer was also evaluated. Results of these analyses demonstrate the system's usefulness.

Dickkopf1 destabilizes atherosclerotic plaques and promotes plaque formation by inducing apoptosis of endothelial cells through activation of ER stress

PubMed Central

Di, Mingxue; Wang, Lin; Li, Mengmeng; Zhang, Yu; Liu, Xinxin; Zeng, Renya; Wang, Han; Chen, Yifei; Chen, Weijia; Zhang, Yun; Zhang, Mei

2017-01-01

Several clinical studies reported that Dickkopf1 (DKK1) plasma levels are correlated with atherosclerosis. However, the impact of DKK1 on the formation and vulnerability of atherosclerotic plaques remains elusive. This study investigated DKK1’s effects on enlargement and destabilization of plaques by targeting endothelial cells and assessing the possible cellular mechanisms involved. The effects of DKK1 on atherogenesis and plaque stability were evaluated in ApoE−/− mice using lentivirus injections to knockdown and knock-in the DKK1 gene. The presence of DKK1 resulted in enlarged and destabilized atherosclerotic lesions and increased apoptosis, while silencing of DKK1 alleviated plaque formation and vulnerability in the whole progression of atherosclerosis. DKK1 expression was upregulated in response to ox-LDL treatment in a time- and concentration-dependent manner on human umbilical vein endothelial cell (HUVEC). The interference of DKK1 reversed ox-LDL-induced apoptosis in HUVECs. The mechanism underlying this effect was DKK1’s activation of the JNK signal transduction pathway and inhibition of canonical Wnt signaling, following by activation of the IRE1α and eif2α/CHOP pathways. In conclusion, DKK1 promotes plaque formation and vulnerability partly by inducing apoptosis in endothelial cells, which partly through inducing the JNK-endoplasmic reticulum stress pathway and inhibiting canonical Wnt signaling. PMID:28703797

Imaging vulnerable plaques by targeting inflammation in atherosclerosis using fluorescent-labeled dual-ligand microparticles of iron oxide and magnetic resonance imaging.

PubMed

Chan, Joyce M S; Monaco, Claudia; Wylezinska-Arridge, Marzena; Tremoleda, Jordi L; Cole, Jennifer E; Goddard, Michael; Cheung, Maggie S H; Bhakoo, Kishore K; Gibbs, Richard G J

2018-05-01

Identification of patients with high-risk asymptomatic carotid plaques remains an elusive but essential step in stroke prevention. Inflammation is a key process in plaque destabilization and a prelude to clinical sequelae. There are currently no clinical imaging tools to assess the inflammatory activity within plaques. This study characterized inflammation in atherosclerosis using dual-targeted microparticles of iron oxide (DT-MPIO) as a magnetic resonance imaging (MRI) probe. DT-MPIO were used to detect and characterize inflammatory markers, vascular cell adhesion molecule 1 (VCAM-1). and P-selectin on (1) tumor necrosis factor-α-treated cells by immunocytochemistry and (2) aortic root plaques of apolipoprotein-E deficient mice by in vivo MRI. Furthermore, apolipoprotein E-deficient mice with focal carotid plaques of different phenotypes were developed by means of periarterial cuff placement to allow in vivo molecular MRI using these probes. The association between biomarkers and the magnetic resonance signal in different contrast groups was assessed longitudinally in these models. Immunocytochemistry confirmed specificity and efficacy of DT-MPIO to VCAM-1 and P-selectin. Using this in vivo molecular MRI strategy, we demonstrated (1) the DT-MPIO-induced magnetic resonance signal tracked with VCAM-1 (r = 0.69; P = .014), P-selectin (r = 0.65; P = .022), and macrophage content (r = 0.59; P = .045) within aortic root plaques and (2) high-risk inflamed plaques were distinguished from noninflamed plaques in the murine carotid artery within a practical clinical imaging time frame. These molecular MRI probes constitute a novel imaging tool for in vivo characterization of plaque vulnerability and inflammatory activity in atherosclerosis. Further development and translation into the clinical arena will facilitate more accurate risk stratification in carotid atherosclerotic disease in the future. Copyright © 2017 Society for Vascular Surgery. Published by

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

PubMed

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.

Identifying Future Disease Hot Spots: Infectious Disease Vulnerability Index.

PubMed

Moore, Melinda; Gelfeld, Bill; Okunogbe, Adeyemi; Paul, Christopher

2017-06-01

Recent high-profile outbreaks, such as Ebola and Zika, have illustrated the transnational nature of infectious diseases. Countries that are most vulnerable to such outbreaks might be higher priorities for technical support. RAND created the Infectious Disease Vulnerability Index to help U.S. government and international agencies identify these countries and thereby inform programming to preemptively help mitigate the spread and effects of potential transnational outbreaks. The authors employed a rigorous methodology to identify the countries most vulnerable to disease outbreaks. They conducted a comprehensive review of relevant literature to identify factors influencing infectious disease vulnerability. Using widely available data, the authors created an index for identifying potentially vulnerable countries and then ranked countries by overall vulnerability score. Policymakers should focus on the 25 most-vulnerable countries with an eye toward a potential "disease belt" in the Sahel region of Africa. The infectious disease vulnerability scores for several countries were better than what would have been predicted on the basis of economic status alone. This suggests that low-income countries can overcome economic challenges and become more resilient to public health challenges, such as infectious disease outbreaks.

Accuracy of MRI to Identify the Coronary Artery Plaque: A Comparative Study With Intravascular Ultrasound

PubMed Central

He, Yi; Zhang, Zhaoqi; Dai, Qinyi; Zhou, Yujie; Yang, Ya; Yu, Wei; An, Jing; Jin, Lixin; Jerecic, Renate; Yuan, Chun; Li, Debiao

2014-01-01

Purpose To evaluate the ability of black-blood coronary arterial wall MRI to identify the coronary artery plaque, using intravascular ultrasound (IVUS) as the golden standard. Materials and Methods Nineteen consecutive patients underwent IVUS and coronary artery wall MRI. Cross-sectional images were acquired on the lesion of coronary artery from the ostium to the middle segment continuously. The vessel cross-sectional area (CSA), luminal CSA, plaque burden, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured in each slice which was then compared with the IVUS images. Results Sixteen of 19 patients completed coronary artery MRA and wall imaging. 41 of 67 slices were found plaques on both IVUS and MRI; The maximal wall thickness, plaque burden, SNR, CNR in the coronary wall containing plaque were greater compared with the normal coronary wall (1.70 ± 0.51 versus 1.24 ± 0.24; 0.71 ± 0.13 versus 0.59 ± 0.12; 1.86 ± 0.41 versus 1.47 ± 0.23; 5.10 ± 2.21 versus 2.99 ± 1.17; respectively, P < 0.05). The matched MRI and IVUS showed good correlation for vessel CSA (16.77 ± 10.67 versus 16.97 ± 8.36; r = 0.79; P < 0.01), luminal CSA (5.18 ± 5.01 versus 7.13 ± 5.14; r = 0.88; P < 0.01), plaque burden (0.71 ± 0.13 versus 0.59 ± 0.15; r = 0.67; P < 0.01). in segments containing plaques, especially the luminal CSA were strongly correlated. Conclusion MRI coronary artery wall imaging can identify coronary plaque in the proximal segments. It also has the potential to assess coronary artery size. PMID:21989946

Complement factor C5a induces atherosclerotic plaque disruptions

PubMed Central

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

2014-01-01

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

Evaluation of the radiolabeled boronic acid-based FAP inhibitor MIP-1232 for atherosclerotic plaque imaging.

PubMed

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

2015-01-27

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

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

PubMed Central

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

2014-01-01

Atherosclerotic plaques develop at particular sites in the arterial tree, and this regional localisation depends largely on haemodynamic parameters (such as wall shear stress; WSS) as described in the literature. Plaque rupture can result in heart attack or stroke and hence understanding the development and vulnerability of atherosclerotic plaques is critically important. The purpose of this study is to characterise the haemodynamics of blood flow in the mouse aortic arch using numerical modelling. The geometries are digitalised from synchrotron imaging and realistic pulsatile blood flow is considered under rigid wall assumptions. Two cases are considered; arteries with and without plaque. Mice that are fed under fat diet present plaques in the aortic arch whose size is dependent on the number of weeks under the diet. The plaque distribution in the region is however relatively constant through the different samples. This result underlines the influence of the geometry and consequently of the wall shear stresses for plaque formation with plaques growing in region of relative low shear stresses. A discussion of the flow field in real geometry in the presence and absence of plaques is conducted. The presence of plaques was shown to alter the blood flow and hence WSS distribution, with regions of localised high WSS, mainly on the wall of the brachiocephalic artery where luminal narrowing is most pronounced. In addition, arch plaques are shown to induce recirculation in the blood flow, a phenomenon with potential influence on the progression of the plaques. The oscillatory shear index and the relative residence time have been calculated on the geometry with plaques to show the presence of this recirculation in the arch, an approach that may be useful for future studies on plaque progression. PMID:25349678

Detection of rupture-prone atherosclerotic plaques by time-resolved laser-induced fluorescence spectroscopy.

PubMed

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

2009-05-01

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

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

PubMed Central

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

2009-01-01

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

Carotid Plaque Morphological Classification Compared With Biomechanical Cap Stress: Implications for a Magnetic Resonance Imaging-Based Assessment.

PubMed

Gijsen, Frank J H; Nieuwstadt, Harm A; Wentzel, Jolanda J; Verhagen, Hence J M; van der Lugt, Aad; van der Steen, Antonius F W

2015-08-01

Two approaches to target plaque vulnerability-a histopathologic classification scheme and a biomechanical analysis-were compared and the implications for noninvasive risk stratification of carotid plaques using magnetic resonance imaging were assessed. Seventy-five histological plaque cross sections were obtained from carotid endarterectomy specimens from 34 patients (>70% stenosis) and subjected to both a Virmani histopathologic classification (thin fibrous cap atheroma with <0.2-mm cap thickness, presumed vulnerable) and a peak cap stress computation (<140 kPa: presumed stable; >300 kPa: presumed vulnerable). To demonstrate the implications for noninvasive plaque assessment, numeric simulations of a typical carotid magnetic resonance imaging protocol were performed (0.62×0.62 mm(2) in-plane acquired voxel size) and used to obtain the magnetic resonance imaging-based peak cap stress. Peak cap stress was generally associated with histological classification. However, only 16 of 25 plaque cross sections could be labeled as high-risk (peak cap stress>300 kPa and classified as a thin fibrous cap atheroma). Twenty-eight of 50 plaque cross sections could be labeled as low-risk (a peak cap stress<140 kPa and not a thin fibrous cap atheroma), leading to a κ=0.39. 31 plaques (41%) had a disagreement between both classifications. Because of the limited magnetic resonance imaging voxel size with regard to cap thickness, a noninvasive identification of only a group of low-risk, thick-cap plaques was reliable. Instead of trying to target only vulnerable plaques, a more reliable noninvasive identification of a select group of stable plaques with a thick cap and low stress might be a more fruitful approach to start reducing surgical interventions on carotid plaques. © 2015 American Heart Association, Inc.

Assessing vulnerability to drought: identifying underlying factors across Europe

NASA Astrophysics Data System (ADS)

Urquijo, Julia; Gonzalez Tánago, Itziar; Ballesteros, Mario; De Stefano, Lucia

2015-04-01

Drought is considered one of the most severe and damaging natural hazards in terms of people and sectors affected and associated losses. Drought is a normal and recurrent climatic phenomenon that occurs worldwide, although its spatial and temporal characteristics vary significantly among climates. In the case of Europe, in the last thirty years, the region has suffered several drought events that have caused estimated economic damages over a €100 billion and have affected almost 20% of its territory and population. In recent years, there has been a growing awareness among experts and authorities of the need to shift from a reactive crisis approach to a drought risk management approach, as well as of the importance of designing and implementing policies, strategies and plans at country and river basin levels to deal with drought. The identification of whom and what is vulnerable to drought is a central aspect of drought risk mitigation and planning and several authors agree that societal vulnerability often determines drought risk more than the actual precipitation shortfalls. The final aim of a drought vulnerability assessment is to identify the underlying sources of drought impact, in order to develop policy options that help to enhance coping capacity and therefore to prevent drought impact. This study identifies and maps factors underlying vulnerability to drought across Europe. The identification of factors influencing vulnerability starts from the analysis of past drought impacts in four European socioeconomic sectors. This analysis, along with an extensive literature review, led to the selection of vulnerability factors that are both relevant and adequate for the European context. Adopting the IPCC model, vulnerability factors were grouped to describe exposure, sensitivity and adaptive capacity. The aggregation of these components has resulted in the mapping of vulnerability to drought across Europe at NUTS02 level. Final results have been compared with

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

NASA Astrophysics Data System (ADS)

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

2006-02-01

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

Noninvasive characterization of carotid plaque strain.

PubMed

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 <0.5; MASSR, 0.58; ESSR, 21.2; VSSR, 0.002). The area of echolucent morphology was greater in high-strain plaques vs low-strain plaques (28% vs 17%; P = .018). Strain measurements showed low variability on Bland-Altman plots with cluster assignment agreement of 76% on repeated scanning. Two patients developed a stroke during 2 years of follow-up; both demonstrated high SSI (≥0.5) at baseline. Carotid plaque strain is reliably computed from routine B-mode imaging using clinical ultrasound machines. High plaque strain correlates with known

Collagen and related extracellular matrix proteins in atherosclerotic plaque development.

PubMed

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.

How does juxtaluminal calcium affect critical mechanical conditions in carotid atherosclerotic plaque? An exploratory study.

PubMed

Zhongzhao Teng; Jing He; Sadat, Umar; Mercer, John R; Xiaoyan Wang; Bahaei, Nasim S; Thomas, Owen M; Gillard, Jonathan H

2014-01-01

The impact of calcification on the carotid atherosclerotic plaque vulnerability remains controversial and unclear. This study assesses the critical mechanical conditions induced by the calcium at the lumen surface, i.e., juxtaluminal calcification (JLCa), within human carotid atherosclerotic plaque. Eleven patients with evidence of JLCa were included for the analysis. The plaque geometry was reconstructed based on computed tomography and magnetic resonance images and 3-D fluid-structure interaction simulation was used for mechanical analysis. The presence of JLCa increased local stresses compared to when calcification was artificially covered with a 0.2-mm-thick fibrous cap (107.87 kPa [76.99, 129.14] versus 63.17 kPa [34.55, 75.13]; Median, [interquartile range]; ). Stretch ratio decreased from 1.18 [1.07, 1.27] to 1.13 [1.10, 1.18] (p = 0.03). The presence of JLCa significantly elevates local stress and stretch level. Further exploration of this plaque feature is warranted as a possible risk factor causing plaque vulnerability.

The effects of the mediterranean diet on biomarkers of vascular wall inflammation and plaque vulnerability in subjects with high risk for cardiovascular disease. A randomized trial.

PubMed

Casas, Rosa; Sacanella, Emilio; Urpí-Sardà, Mireia; Chiva-Blanch, Gemma; Ros, Emilio; Martínez-González, Miguel-Angel; Covas, Maria-Isabel; Salas-Salvadó, Jordi; Fiol, Miquel; Arós, Fernando; Estruch, Ramon

2014-01-01

Adherence to the Mediterranean diet (MD) is associated with reduced morbidity and mortality due to cardiovascular disease. However, how the MD exerts its effects is not fully known. To assess the 12-month effects of two enhanced MDs compared to a low-fat diet on inflammatory biomarkers related to atherosclerosis and plaque vulnerability in a subcohort of the PREDIMED (Prevención con Dieta Mediterránea) study. A total of 164 participants at high risk for cardiovascular disease were randomized into three diet groups: MD supplemented with 50mL/d of extra virgin olive oil (MD+EVOO) or 30 g/d of nuts (MD+Nuts) and a low-fat diet. Changes in classical cardiovascular risk factors, inflammatory biomarkers of atherosclerosis and plaque vulnerability were measured after 12 months of intervention. Compared to participants in the low-fat diet group, those receiving MD+EVOO and MD+Nuts showed a higher decrease in systolic (6mmHg) and diastolic (3mmHg) blood pressure (P = 0.02; both), as well as a reduction of 10% and 8% in LDL-cholesterol (P = 0.04), respectively. Patients in the MD+Nuts group showed a significant reduction of 34% in CD40 expression on monocyte surface compared to low-fat diet patients (P = 0.03). In addition, inflammatory biomarkers related to plaque instability such as C-reactive protein and interleukin-6 were reduced by 45% and 35% and 95% and 90% in the MD+EVOO and MD+Nuts groups, respectively (P<0.05; all) compared to the low-fat diet group. Likewise, sICAM and P-selectin were also reduced by 50% and 27%, respectively in the MD+EVOO group (P = 0.04) and P-selectin by 19% in MD+Nuts group (P = 0.04) compared to the low-fat diet group. Adherence to the MD is associated with an increase in serum markers of atheroma plaque stability which may explain, at least in part, the protective role of MD against ischemic heart disease. www.controlled-trials.com ISRCTN35739639.

Application of infrared fiber optic imaging in atherosclerotic plaques

NASA Astrophysics Data System (ADS)

Guo, Bujin; Casscells, S. W.; Bearman, Gregory H.; McNatt, Janice; Naghevi, Morteza; Malik, Basit A.; Gul, Khawar; Willerson, James T.

1999-07-01

Rupture of atherosclerotic plaques - the main cause of heart attach and stokes - is not predictable. Hence even treadmill stress tests fail to detect many persons at risk. Fatal plaques are found at autopsies to be associated with active inflammatory cells. Classically, inflammation is detected by its swelling, red color, pain and heat. We have found that heat accurately locates the dangerous plaques that are significantly warmer then atherosclerotic plaques without the same inflammation. In order to develop a non-surgical method of locating these plaques, an IR fiber optic imaging system has been developed in our laboratory to evalute the causes and effect of heat in atherosclerotic plaques. The fiber optical imagin bundle consists of 900 individual As2S3 chalcogenide glass fibers which transmit IR radiation from 0.7 micrometers 7 micrometers with little energy loss. By combining that with a highly sensitive Indium Antimonide IR focal plane array detector, we are able to obtain thermal graphic images in situ. The temperature heterogeneity of atherosclerotic plaques developed in the arteral of the experimental animal models is under study with the new device. The preliminary experimental results from the animal model are encouraging. The potential of using this new technology in diagnostic evaluation of the vulnerable atherosclerotic plaques is considerable.

64Cu-DOTATATE PET/MRI for Detection of Activated Macrophages in Carotid Atherosclerotic Plaques: Studies in Patients Undergoing Endarterectomy.

PubMed

Pedersen, Sune Folke; Sandholt, Benjamin Vikjær; Keller, Sune Høgild; Hansen, Adam Espe; Clemmensen, Andreas Ettrup; Sillesen, Henrik; Højgaard, Liselotte; Ripa, Rasmus Sejersten; Kjær, Andreas

2015-07-01

A feature of vulnerable atherosclerotic plaques of the carotid artery is high activity and abundance of lesion macrophages. There is consensus that this is of importance for plaque vulnerability, which may lead to clinical events, such as stroke and transient ischemic attack. We used positron emission tomography (PET) and the novel PET ligand [(64)Cu] [1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid]-d-Phe1,Tyr3-octreotate ((64)Cu-DOTATATE) to specifically target macrophages via the somatostatin receptor subtype-2 in vivo. Ten patients underwent simultaneous PET/MRI to measure (64)Cu-DOTATATE uptake in carotid artery plaques before carotid endarterectomy. (64)Cu-DOTATATE uptake was significantly higher in symptomatic plaque versus the contralateral carotid artery (P<0.001). Subsequently, a total of 62 plaque segments were assessed for gene expression of selected markers of plaque vulnerability using real-time quantitative polymerase chain reaction. These results were compared with in vivo (64)Cu-DOTATATE uptake calculated as the mean standardized uptake value. Univariate analysis of real-time quantitative polymerase chain reaction and PET showed that cluster of differentiation 163 (CD163) and CD68 gene expression correlated significantly but weakly with mean standardized uptake value in scans performed 85 minutes post injection (P<0.001 and P=0.015, respectively). Subsequent multivariate analysis showed that CD163 correlated independently with (64)Cu-DOTATATE uptake (P=0.031) whereas CD68 did not contribute significantly to the final model. The novel PET tracer (64)Cu-DOTATATE accumulates in atherosclerotic plaques of the carotid artery. CD163 gene expression correlated independently with (64)Cu-DOTATATE uptake measured by real-time quantitative polymerase chain reaction in the final multivariate model, indicating that (64)Cu-DOTATATE PET is detecting alternatively activated macrophages. This association could potentially improve noninvasive

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

PubMed

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.

Short communication: Dating components of human atherosclerotic plaques.

PubMed

Gonçalves, Isabel; Stenström, Kristina; Skog, Göran; Mattsson, Sören; Nitulescu, Mihaela; Nilsson, Jan

2010-04-02

Atherosclerotic plaques that give rise to acute clinical symptoms are typically characterized by degradation of the connective tissue and plaque rupture. Experimental studies have shown that mechanisms to repair vulnerable lesions exist, but the rate of remodeling of human plaque tissue has not been studied. In the present study, we determined the biological age of different components of advanced human atherosclerotic plaques by analyzing tissue levels of (14)C released into the atmosphere during the nuclear weapons tests in the late 1950s and early 1960s. Atherosclerotic plaques were obtained from 10 patients (age 46 to 80 years) undergoing carotid surgery. Different regions of the plaques were dissected and analyzed for (14)C content using accelerator mass spectrometry. At the time of surgery, the mean biological age of the cap region was 6.4+/-3.2 years, which was significantly lower than that of the shoulder region (12.9+/-3.0 years, P<0.01), the interface toward the media (12.4+/-3.3 years, P<0.01), and the core (9.8+/-4.5 years, P<0.05). Analysis of proliferative activity and rate of apoptosis showed no signs of increased cellular turnover in the cap, suggesting that the lower (14)C content reflected a more recent time of formation. These results show that the turnover time of human plaque tissue is very long and may explain why regression of atherosclerotic plaque size rarely is observed in cardiovascular intervention trials.

Lipid peroxidation and decomposition-Conflicting roles in plaque vulnerability and stability

PubMed Central

Parthasarathy, Sampath; Litvinov, Dmitry; Selvarajan, Krithika; Garelnabi, Mahdi

2008-01-01

The low density lipoprotein (LDL) oxidation hypothesis has generated considerable interest in oxidative stress and how it might affect atherosclerosis. However, the failure of antioxidants, particularly vitamin E, to affect the progression of the disease in humans has convinced even staunch supporters of the hypothesis to take a step backwards and reconsider alternatives. Preponderant evidence for the hypothesis came from animal antioxidant intervention studies. In this review we point out basic differences between animal and human atherosclerosis development and suggest that human disease starts where animal studies end. While initial oxidative steps in the generation of early fatty streak lesions might be common, the differences might be in the steps involved in the decomposition of peroxidized lipids into aldehydes and their further oxidation into carboxylic acids. We suggest that these steps may not be amenable to attenuation by antioxidants and antioxidants might actually counter the stabilization of plaque by preventing the formation of carboxylic acids which are anti-inflammatory in nature. The formation of such dicarboxylic acids may also be conducive to plaque stabilization by trapping calcium. We suggest that agents that would prevent the decomposition of lipid peroxides and promote the formation and removal of lipid hydroxides, such as paraoxonase (PON 1) or apo A1/high density lipoprotein (HDL) might be more conducive to plaque regression. PMID:18406361

On the potential of a new IVUS elasticity modulus imaging approach for detecting vulnerable atherosclerotic coronary plaques: In vitro vessel phantom study

PubMed Central

Le Floc’h, Simon; Cloutier, Guy; Finet, Gérard; Tracqui, Philippe; Pettigrew, Roderic I.; Ohayon, Jacques

2016-01-01

Peak cap stress amplitude is recognized as a good indicator of vulnerable plaque (VP) rupture. However, such stress evaluation strongly relies on a precise, but still lacking, knowledge of the mechanical properties exhibited by the plaque components. As a first response to this limitation, our group recently developed, in a previous theoretical study, an original approach, called iMOD, which reconstructs elasticity maps (or modulograms) of atheroma plaques from the estimation of strain fields. In the present in vitro experimental study, conducted on PVA-C arterial phantoms, we investigate the benefit of coupling the iMOD procedure with the acquisition of intravascular ultrasound (IVUS) measurements for detection of VP. Our results show that the combined iMOD-IVUS strategy : 1) successfully detected and quantified soft inclusion contours with high positive predictive values and sensitivities of 89.7 ± 3.9% and 81.5 ± 8.8 %, respectively, 2) estimated reasonably cap thicknesses larger than ~300 µm, but underestimated thinner caps, and 3) quantified satisfactorily Young's modulus of hard medium (mean value of 109.7 ± 23.7 kPa instead of 145.4 ± 31.8 kPa), but overestimated the stiffness of soft inclusions (mean Young`s moduli of 31.4 ± 9.7 kPa instead of 17.6 ± 3.4 kPa). All together, these results demonstrate a promising benefit of the new iMOD-IVUS clinical imaging method for in vivo VP detection. PMID:20826899

Localization of Coronary High-Intensity Signals on T1-Weighted MR Imaging: Relation to Plaque Morphology and Clinical Severity of Angina Pectoris.

PubMed

Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Otsuka, Kenichiro; Yoshikawa, Junichi; Shimada, Kenei

2015-10-01

This study sought to investigate the relationship between localization of high-intensity signals (HISs) on T1-weighted imaging (T1WI) with the noncontrast magnetic resonance technique and plaque morphology detected on optical coherence tomography, and the clinical severity of angina pectoris. Since the introduction of the T1WI noncontrast magnetic resonance technique for plaque imaging, some groups have reported that HISs in the coronary artery on T1WI are associated with a vulnerable morphology and future cardiac events. However, the association between the localization of HISs, such as coronary intrawall or intraluminal, and plaque morphology has not been investigated. One hundred lesions with either stable or unstable angina were included and divided into 3 groups according to the following criteria using T1WI. First, the plaques with the ratio between the signal intensities of coronary plaque and cardiac muscle ≤1.0 were classified as non-HISs (n = 39). Then, HISs with the ratio between the signal intensities of coronary plaque and cardiac muscle >1.0 were classified into 2 types by using cross-sectional T1WI. Those localized within the coronary wall when the lumen was identified were defined as intrawall HISs (n = 37), whereas those occupying the lumen when the lumen was not, or even if only partly, identified, were defined as intraluminal HISs (n = 24). Multivariate analysis revealed that intrawall HISs were associated with macrophage accumulation and the absence of calcification assessed by using optical coherence tomography. In contrast, thrombus and intimal vasculature were independent factors associated with intraluminal HISs. Furthermore, 50% of patients with intraluminal HISs experienced rest angina, such as Braunwald class II or III. This study shows that intrawall and intraluminal HISs on T1WI in patients with angina are related to the different types of vulnerable plaque morphology and the clinical severity. Copyright © 2015 American College of

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

PubMed

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

2014-03-03

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multicenter AIDS Cohort Study Quantitative Coronary Plaque Progression Study: rationale and design.

PubMed

Nakanishi, Rine; Post, Wendy S; Osawa, Kazuhiro; Jayawardena, Eranthi; Kim, Michael; Sheidaee, Nasim; Nezarat, Negin; Rahmani, Sina; Kim, Nicholas; Hathiramani, Nicolai; Susarla, Shriraj; Palella, Frank; Witt, Mallory; Blaha, Michael J; Brown, Todd T; Kingsley, Lawrence; Haberlen, Sabina A; Dailing, Christopher; Budoff, Matthew J

2018-01-01

The association of HIV with coronary atherosclerosis has been established; however, the progression of coronary atherosclerosis over time among participants with HIV is not well known. The Multicenter AIDS Cohort Study Quantitative Coronary Plaque Progression Study is a large prospective multicenter study quantifying progression of coronary plaque assessed by serial coronary computed tomography angiography (CTA). HIV-infected and uninfected men who were enrolled in the Multicenter AIDS Cohort Study Cardiovascular Substudy were eligible to complete a follow-up contrast coronary CTA 3-6 years after baseline. We measured coronary plaque volume and characteristics (calcified and noncalcified plaque including fibrous, fibrous-fatty, and low attenuation) and vulnerable plaque among HIV-infected and uninfected men using semiautomated plaque software to investigate the progression of coronary atherosclerosis over time. We describe a novel, large prospective multicenter study investigating incidence, transition of characteristics, and progression in coronary atherosclerosis quantitatively assessed by serial coronary CTAs among HIV-infected and uninfected men.

Elevated Levels of Serum Fibrin and Fibrinogen Degradation Products Are Independent Predictors of Larger Coronary Plaques and Greater Plaque Necrotic Core

PubMed Central

Corban, Michel T; Hung, Olivia Y; Mekonnen, Girum; Eshtehardi, Parham; Eapen, Danny J; Rasoul-Arzrumly, Emad; Kassem, Hatem Al; Manocha, Pankaj; Ko, Yi-An; Sperling, Laurence S; Quyyumi, Arshed A; Samady, Habib

2016-01-01

Background Co-existence of vulnerable plaque and pro-thrombotic state may provoke acute coronary events. It was hypothesized that elevated serum levels of fibrin and fibrinogen degradation products (FDP) are associated with larger total plaque and necrotic core (NC) areas. Methods and Results Seventy-five patients presenting with stable anginal symptoms (69%) or stabilized acute coronary syndrome (ACS; 31%), and found to have non-obstructive coronary artery disease (CAD) with a fractional flow reserve >0.8, were studied. Invasive virtual histology intravascular ultrasound (VH-IVUS) was performed in 68 LAD arteries, 6 circumflex arteries, and 1 right coronary artery. Serum FDP levels were measured using ELISA technique. Plaque volumetrics and composition were assessed in each VH-IVUS frame and averaged. The median age of patients was 56 (47–63) years; 52% were men and 23% had diabetes. The average length of coronary artery studied was 62 mm. After adjustment for systemic risk factors, medications, CRP levels and ACS, male gender (P<0.001) and serum FDP levels (P=0.02) were independent predictors of a larger NC area. Older age (P<0.001), male gender (P<0.0001) and increased serum FDP level (P=0.03) were associated with a larger plaque area. Conclusions In patients with CAD, a higher serum level of FDP is independently associated with larger plaques and greater plaque NC. PMID:26911453

Elevated Levels of Serum Fibrin and Fibrinogen Degradation Products Are Independent Predictors of Larger Coronary Plaques and Greater Plaque Necrotic Core.

PubMed

Corban, Michel T; Hung, Olivia Y; Mekonnen, Girum; Eshtehardi, Parham; Eapen, Danny J; Rasoul-Arzrumly, Emad; Al Kassem, Hatem; Manocha, Pankaj; Ko, Yi-An; Sperling, Laurence S; Quyyumi, Arshed A; Samady, Habib

2016-01-01

Co-existence of vulnerable plaque and pro-thrombotic state may provoke acute coronary events. It was hypothesized that elevated serum levels of fibrin and fibrinogen degradation products (FDP) are associated with larger total plaque and necrotic core (NC) areas. Seventy-five patients presenting with stable anginal symptoms (69%) or stabilized acute coronary syndrome (ACS; 31%), and found to have non-obstructive coronary artery disease (CAD) with a fractional flow reserve >0.8, were studied. Invasive virtual histology intravascular ultrasound (VH-IVUS) was performed in 68 LAD arteries, 6 circumflex arteries, and 1 right coronary artery. Serum FDP levels were measured using ELISA technique. Plaque volumetrics and composition were assessed in each VH-IVUS frame and averaged. The median age of patients was 56 (47-63) years; 52% were men and 23% had diabetes. The average length of coronary artery studied was 62 mm. After adjustment for systemic risk factors, medications, CRP levels and ACS, male gender (P<0.001) and serum FDP levels (P=0.02) were independent predictors of a larger NC area. Older age (P<0.001), male gender (P<0.0001) and increased serum FDP level (P=0.03) were associated with a larger plaque area. In patients with CAD, a higher serum level of FDP is independently associated with larger plaques and greater plaque NC.

Magnetic resonance imaging of atherothrombotic plaques.

PubMed

Usman, Ammara; Sadat, Umar; Graves, Martin J; Gillard, Jonathan H

2015-11-01

Atherosclerosis remains the leading cause of long term morbidity and mortality worldwide, despite significant advances in its management. Vulnerable atherothrombotic plaques are predominantly responsible for thromboembolic ischaemic events in arterial beds, such as the carotid, coronary and lower limb arteries. MRI has emerged as a non-invasive, non-irradiating and highly reproducible imaging technique which allows detailed morphological and functional assessment of such plaques. It also has the potential to monitor the efficacy of established and evolving anti-atherosclerosis drugs. It is envisaged that by careful identification and understanding of the underlying cellular and molecular mechanisms that govern atherosclerosis, novel treatment strategies can be formulated which may reduce the persistent high mortality and morbidity rates associated with this disease. MRI shows promise in achieving this goal. Copyright © 2015 Elsevier Ltd. All rights reserved.

Use of modeling to identify vulnerabilities to human error in laparoscopy.

PubMed

Funk, Kenneth H; Bauer, James D; Doolen, Toni L; Telasha, David; Nicolalde, R Javier; Reeber, Miriam; Yodpijit, Nantakrit; Long, Myra

2010-01-01

This article describes an exercise to investigate the utility of modeling and human factors analysis in understanding surgical processes and their vulnerabilities to medical error. A formal method to identify error vulnerabilities was developed and applied to a test case of Veress needle insertion during closed laparoscopy. A team of 2 surgeons, a medical assistant, and 3 engineers used hierarchical task analysis and Integrated DEFinition language 0 (IDEF0) modeling to create rich models of the processes used in initial port creation. Using terminology from a standardized human performance database, detailed task descriptions were written for 4 tasks executed in the process of inserting the Veress needle. Key terms from the descriptions were used to extract from the database generic errors that could occur. Task descriptions with potential errors were translated back into surgical terminology. Referring to the process models and task descriptions, the team used a modified failure modes and effects analysis (FMEA) to consider each potential error for its probability of occurrence, its consequences if it should occur and be undetected, and its probability of detection. The resulting likely and consequential errors were prioritized for intervention. A literature-based validation study confirmed the significance of the top error vulnerabilities identified using the method. Ongoing work includes design and evaluation of procedures to correct the identified vulnerabilities and improvements to the modeling and vulnerability identification methods. Copyright 2010 AAGL. Published by Elsevier Inc. All rights reserved.

Potential benefits of eicosapentaenoic acid on atherosclerotic plaques.

PubMed

Nelson, J R; Wani, O; May, H T; Budoff, M

2017-04-01

Residual cardiovascular (CV) risk remains in some patients despite optimized statin therapy and may necessitate add-on therapy to reduce this risk. Eicosapentaenoic acid (EPA), an omega-3 polyunsaturated fatty acid, lowers plasma triglyceride levels without raising low-density lipoprotein cholesterol levels and has potential beneficial effects on atherosclerotic plaques. Animal studies have shown that EPA reduces levels of pro-inflammatory cytokines and chemokines. In clinical trials utilizing a wide spectrum of plaque imaging modalities, EPA has shown beneficial effects on plaque characteristics. Studies of patients with coronary artery disease receiving statin therapy suggest that EPA may decrease plaque vulnerability and prevent plaque progression. EPA also decreased pentraxin-3 and macrophage accumulation. A large, randomized, Japanese study reported that EPA plus a statin resulted in a 19% relative reduction in major coronary events at 5years versus a statin alone in patients with hypercholesterolemia (P=0.011). Icosapent ethyl, a high-purity prescription form of EPA ethyl ester, has been shown to reduce triglyceride levels and markers of atherosclerotic inflammation. Results of an ongoing CV outcomes study will further define the potential clinical benefits of icosapent ethyl in reducing CV risk in high-risk patients receiving statin therapy. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Identifying Frailty Among Vulnerable Populations

PubMed Central

Salem, Benissa E.; Nyamathi, Adeline; Phillips, Linda R.; Mentes, Janet; Sarkisian, Catherine; Brecht, Lynn

2014-01-01

Frailty is a significant public health issue which is experienced by homeless and other vulnerable adults; to date, a frailty framework has not been proposed to guide researchers who study this hard-to-reach population. The Frailty Framework among Homeless and other Vulnerable Populations (FFHVP) has been developed from empirical research and consultation with frailty experts in an effort to characterize antecedents, i.e. situational, health-related, behavioral, resource, biological, and environmental factors which contribute to physical, psychological and social frailty domains and impact adverse outcomes. As vulnerable populations continue to age, a greater understanding of frailty will enable the development of nursing interventions. PMID:24469090

Chronic miR-29 antagonism promotes favorable plaque remodeling in atherosclerotic mice.

PubMed

Ulrich, Victoria; Rotllan, Noemi; Araldi, Elisa; Luciano, Amelia; Skroblin, Philipp; Abonnenc, Mélanie; Perrotta, Paola; Yin, Xiaoke; Bauer, Ashley; Leslie, Kristen L; Zhang, Pei; Aryal, Binod; Montgomery, Rusty L; Thum, Thomas; Martin, Kathleen; Suarez, Yajaira; Mayr, Manuel; Fernandez-Hernando, Carlos; Sessa, William C

2016-06-01

Abnormal remodeling of atherosclerotic plaques can lead to rupture, acute myocardial infarction, and death. Enhancement of plaque extracellular matrix (ECM) may improve plaque morphology and stabilize lesions. Here, we demonstrate that chronic administration of LNA-miR-29 into an atherosclerotic mouse model improves indices of plaque morphology. This occurs due to upregulation of miR-29 target genes of the ECM (col1A and col3A) resulting in reduced lesion size, enhanced fibrous cap thickness, and reduced necrotic zones. Sustained LNA-miR-29 treatment did not affect circulating lipids, blood chemistry, or ECM of solid organs including liver, lung, kidney, spleen, or heart. Collectively, these data support the idea that antagonizing miR-29 may promote beneficial plaque remodeling as an independent approach to stabilize vulnerable atherosclerotic lesions. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

A direct vulnerable atherosclerotic plaque elasticity reconstruction method based on an original material-finite element formulation: theoretical framework

PubMed Central

Bouvier, Adeline; Deleaval, Flavien; Doyley, Marvin M; Yazdani, Saami K; Finet, Gérard; Le Floc'h, Simon; Cloutier, Guy; Pettigrew, Roderic I; Ohayon, Jacques

2016-01-01

The peak cap stress (PCS) amplitude is recognized as a biomechanical predictor of vulnerable plaque (VP) rupture. However, quantifying PCS in vivo remains a challenge since the stress depends on the plaque mechanical properties. In response, an iterative material finite element (FE) elasticity reconstruction method using strain measurements has been implemented for the solution of these inverse problems. Although this approach could resolve the mechanical characterization of VPs, it suffers from major limitations since (i) it is not adapted to characterize VPs exhibiting high material discontinuities between inclusions, and (ii) does not permit real time elasticity reconstruction for clinical use. The present theoretical study was therefore designed to develop a direct material-FE algorithm for elasticity reconstruction problems which accounts for material heterogeneities. We originally modified and adapted the extended FE method (Xfem), used mainly in crack analysis, to model material heterogeneities. This new algorithm was successfully applied to six coronary lesions of patients imaged in vivo with intravascular ultrasound. The results demonstrated that the mean relative absolute errors of the reconstructed Young's moduli obtained for the arterial wall, fibrosis, necrotic core, and calcified regions of the VPs decreased from 95.3±15.56%, 98.85±72.42%, 103.29±111.86% and 95.3±10.49%, respectively, to values smaller than 2.6 × 10−8±5.7 × 10−8% (i.e. close to the exact solutions) when including modified-Xfem method into our direct elasticity reconstruction method. PMID:24240392

Identifying typical patterns of vulnerability: A 5-step approach based on cluster analysis

NASA Astrophysics Data System (ADS)

Sietz, Diana; Lüdeke, Matthias; Kok, Marcel; Lucas, Paul; Carsten, Walther; Janssen, Peter

2013-04-01

Specific processes that shape the vulnerability of socio-ecological systems to climate, market and other stresses derive from diverse background conditions. Within the multitude of vulnerability-creating mechanisms, distinct processes recur in various regions inspiring research on typical patterns of vulnerability. The vulnerability patterns display typical combinations of the natural and socio-economic properties that shape a systems' vulnerability to particular stresses. Based on the identification of a limited number of vulnerability patterns, pattern analysis provides an efficient approach to improving our understanding of vulnerability and decision-making for vulnerability reduction. However, current pattern analyses often miss explicit descriptions of their methods and pay insufficient attention to the validity of their groupings. Therefore, the question arises as to how do we identify typical vulnerability patterns in order to enhance our understanding of a systems' vulnerability to stresses? A cluster-based pattern recognition applied at global and local levels is scrutinised with a focus on an applicable methodology and practicable insights. Taking the example of drylands, this presentation demonstrates the conditions necessary to identify typical vulnerability patterns. They are summarised in five methodological steps comprising the elicitation of relevant cause-effect hypotheses and the quantitative indication of mechanisms as well as an evaluation of robustness, a validation and a ranking of the identified patterns. Reflecting scale-dependent opportunities, a global study is able to support decision-making with insights into the up-scaling of interventions when available funds are limited. In contrast, local investigations encourage an outcome-based validation. This constitutes a crucial step in establishing the credibility of the patterns and hence their suitability for informing extension services and individual decisions. In this respect, working at

Comparison by optical coherence tomography of the frequency of lipid coronary plaques in current smokers, former smokers, and nonsmokers.

PubMed

Abtahian, Farhad; Yonetsu, Taishi; Kato, Koji; Jia, Haibo; Vergallo, Rocco; Tian, Jinwei; Hu, Sining; McNulty, Iris; Lee, Hang; Yu, Bo; Jang, Ik-Kyung

2014-09-01

Smoking is associated with high incidence of cardiovascular events including acute coronary syndrome. We sought to characterize coronary plaques in patients with ongoing smoking using optical coherence tomography (OCT) compared with former smokers and nonsmokers. We identified 465 coronary plaques from 182 subjects who underwent OCT imaging for all 3 coronary arteries. Subjects were divided into 3 groups: current smokers (n = 41), former smokers (n = 67), and nonsmokers (n = 74). OCT analysis included the presence of lipid-rich plaque, thin-cap fibroatheroma (TCFA), calcification, maximum lipid arc, lipid core length, lipid index, and fibrous cap thickness. Lipid index was defined by mean lipid arc multiplied by lipid core length. Compared with former smokers and nonsmokers, the incidence of lipid plaques and TCFA was significantly higher in current smokers (lipid plaques: 68.0% vs 45.9% and 52.6%, p = 0.002; TCFA: 18.4% vs 7.6% and 9.9%, p = 0.018). There was a trend for higher plaque disruption in current smokers. Former smokers were more likely to have calcified plaques than current and nonsmokers (52.9% vs 32.0% and 38.0%, p = 0.001). In a multivariate analysis, current smoking, low-density lipoprotein, and presentation with acute coronary syndrome were independently associated with the presence of TCFAs. In conclusion, current smokers are more likely to have lipid plaques and OCT-defined vulnerable plaques (TCFAs). Former smokers have increased number of calcified plaques. These results may explain the increased risk of acute cardiac events among smokers. Copyright © 2014 Elsevier Inc. All rights reserved.

A GIS Approach to Identifying Socially and Medically Vulnerable Older Adult Populations in South Florida.

PubMed

Hames, Elizabeth; Stoler, Justin; Emrich, Christopher T; Tewary, Sweta; Pandya, Naushira

2017-11-10

We define, map, and analyze geodemographic patterns of socially and medically vulnerable older adults within the tri-county region of South Florida. We apply principal components analysis (PCA) to a set of previously identified indicators of social and medical vulnerability at the census tract level. We create and map age-stratified vulnerability scores using a geographic information system (GIS), and use spatial analysis techniques to identify patterns and interactions between social and medical vulnerability. Key factors contributing to social vulnerability in areas with higher numbers of older adults include age, large household size, and Hispanic ethnicity. Medical vulnerability in these same areas is driven by disease burden, access to emergency cardiac services, availability of nursing home and hospice beds, access to home health care, and available mental health services. Age-dependent areas of social vulnerability emerge in Broward County, whereas age-dependent areas of medical vulnerability emerge in Palm Beach County. Older-adult social and medical vulnerability interact differently throughout the study area. Spatial analysis of older adult social and medical vulnerability using PCA and GIS can help identify age-dependent pockets of vulnerability that are not easily identifiable in a populationwide analysis; improve our understanding of the dynamic spatial organization of health care, health care needs, access to care, and outcomes; and ultimately serve as a tool for health care planning. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Diminazene enhances stability of atherosclerotic plaques in ApoE-deficient mice

PubMed Central

Fraga-Silva, Rodrigo A.; Montecucco, Fabrizio; Costa-Fraga, Fabiana P.; Nencioni, Alessio; Caffa, Irene; Bragina, Maiia E.; Mach, François; Raizada, Mohan K.; Santos, Robson A.S.; da Silva, Rafaela F.; Stergiopulos, Nikolaos

2017-01-01

Angiotensin (Ang) II contributes to the development of atherosclerosis, while Ang-(1–7) has atheroprotective actions. Accordingly, angiotensin-converting enzyme 2 (ACE2), which breaks-down Ang II and forms Ang-(1–7), has been suggested as a target against atherosclerosis. Here we investigated the actions of diminazene, a recently developed ACE2 activator compound, in a model of vulnerable atherosclerotic plaque. Atherosclerotic plaque formation was induced in the carotid artery of ApoE-deficient mice by a shear stress (SS) modiffer device. The animals were treated with diminazene (15 mg/kg/day) or vehicle. ACE2 was strongly expressed in the aortic root and low SS-induced carotid plaques, but poorly expressed in the oscillatory SS-induced carotid plaques. Diminazene treatment did not change the lesion size, but ameliorated the composition of aortic root and low SS-induced carotid plaques by increasing collagen content and decreasing both MMP-9 expression and macrophage infiltration. Interestingly, these beneficial effects were not observed in the oscillatory SS-induced plaque. Additionally, diminazene treatment decreased intraplaque ICAM-1 and VCAM-1 expression, circulating cytokine and chemokine levels and serum triglycerides. In summary, ACE2 was distinctively expressed in atherosclerotic plaques, which depends on the local pattern of shear stress. Moreover, diminazene treatment enhances the stability of atherosclerotic plaques. PMID:26304699

PLACD-7T Study: Atherosclerotic Carotid Plaque Components Correlated with Cerebral Damage at 7 Tesla Magnetic Resonance Imaging.

PubMed

den Hartog, A G; Bovens, S M; Koning, W; Hendrikse, J; Pasterkamp, G; Moll, F L; de Borst, G J

2011-02-01

In patients with carotid artery stenosis histological plaque composition is associated with plaque stability and with presenting symptomatology. Preferentially, plaque vulnerability should be taken into account in pre-operative work-up of patients with severe carotid artery stenosis. However, currently no appropriate and conclusive (non-) invasive technique to differentiate between the high and low risk carotid artery plaque in vivo is available. We propose that 7 Tesla human high resolution MRI scanning will visualize carotid plaque characteristics more precisely and will enable correlation of these specific components with cerebral damage. The aim of the PlaCD-7T study is 1: to correlate 7T imaging with carotid plaque histology (gold standard); and 2: to correlate plaque characteristics with cerebral damage ((clinically silent) cerebral (micro) infarcts or bleeds) on 7 Tesla high resolution (HR) MRI. We propose a single center prospective study for either symptomatic or asymptomatic patients with haemodynamic significant (70%) stenosis of at least one of the carotid arteries. The Athero-Express (AE) biobank histological analysis will be derived according to standard protocol. Patients included in the AE and our prospective study will undergo a pre-operative 7 Tesla HR-MRI scan of both the head and neck area. We hypothesize that the 7 Tesla MRI scanner will allow early identification of high risk carotid plaques being associated with micro infarcted cerebral areas, and will thus be able to identify patients with a high risk of periprocedural stroke, by identification of surrogate measures of increased cardiovascular risk.

PLACD-7T Study: Atherosclerotic Carotid Plaque Components Correlated with Cerebral Damage at 7 Tesla Magnetic Resonance Imaging

PubMed Central

den Hartog, A.G; Bovens, S.M; Koning, W; Hendrikse, J; Pasterkamp, G; Moll, F.L; de Borst, G.J

2011-01-01

Introduction: In patients with carotid artery stenosis histological plaque composition is associated with plaque stability and with presenting symptomatology. Preferentially, plaque vulnerability should be taken into account in pre-operative work-up of patients with severe carotid artery stenosis. However, currently no appropriate and conclusive (non-) invasive technique to differentiate between the high and low risk carotid artery plaque in vivo is available. We propose that 7 Tesla human high resolution MRI scanning will visualize carotid plaque characteristics more precisely and will enable correlation of these specific components with cerebral damage. Study objective: The aim of the PlaCD-7T study is 1: to correlate 7T imaging with carotid plaque histology (gold standard); and 2: to correlate plaque characteristics with cerebral damage ((clinically silent) cerebral (micro) infarcts or bleeds) on 7 Tesla high resolution (HR) MRI. Design: We propose a single center prospective study for either symptomatic or asymptomatic patients with haemodynamic significant (70%) stenosis of at least one of the carotid arteries. The Athero-Express (AE) biobank histological analysis will be derived according to standard protocol. Patients included in the AE and our prospective study will undergo a pre-operative 7 Tesla HR-MRI scan of both the head and neck area. Discussion: We hypothesize that the 7 Tesla MRI scanner will allow early identification of high risk carotid plaques being associated with micro infarcted cerebral areas, and will thus be able to identify patients with a high risk of periprocedural stroke, by identification of surrogate measures of increased cardiovascular risk. PMID:22294972

Application of the laguerre deconvolution method for time-resolved fluorescence spectroscopy to the characterization of atherosclerotic plaques.

PubMed

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

2005-01-01

This study investigates the ability of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) to detect inflammation in atherosclerotic lesion, a key feature of plaque vulnerability. A total of 348 TR-LIFS measurements were taken from carotid plaques of 30 patients, and subsequently analyzed using the Laguerre deconvolution technique. The investigated spots were classified as Early, Fibrotic/Calcified or Inflamed lesions. A stepwise linear discriminant analysis algorithm was developed using spectral and TR features (normalized intensity values and Laguerre expansion coefficients at discrete emission wavelengths, respectively). Features from only three emission wavelengths (390, 450 and 500 nm) were used in the classifier. The Inflamed lesions were discriminated with sensitivity > 80% and specificity > 90 %, when the Laguerre expansion coefficients were included in the feature space. These results indicate that TR-LIFS information derived from the Laguerre expansion coefficients at few selected emission wavelengths can discriminate inflammation in atherosclerotic plaques. We believe that TR-LIFS derived Laguerre expansion coefficients can provide a valuable additional dimension for the detection of vulnerable plaques.

High-risk carotid plaque: lessons learned from histopathology.

PubMed

Kolodgie, Frank D; Yahagi, Kazuyuki; Mori, Hiroyoshi; Romero, Maria E; Trout, Hugh H; Finn, Aloke V; Virmani, Renu

2017-03-01

The pathophysiology and natural history of atherosclerotic carotid disease is predicated on a more extensive knowledge of lesion progression gained in the studies conducted in the coronary arteries, and these will be reviewed. While the precise sequence of lesion progression leading to carotid plaque vulnerability and cerebrovascular events remain less well understood, specific early and more advanced progressive lesion morphologies associated with stroke risk have been characterized. Of late, there has been a conscious effort for stroke prevention in symptomatic and asymptomatic patients to move beyond luminal stenosis as the only guidance to predict future cerebrovascular events. Driving this strategy are recent advances in medical imaging modalities to assess carotid atherosclerosis vulnerability particularly involving molecular imaging, which is now positioned at the forefront to provide a more detailed and mechanistic assessment of stroke risk. As such, we will spotlight the pathology of high-risk carotid plaques in patients with symptomatic and asymptomatic carotid disease with further reference into more recent mechanistic insights involving a recognized macrophage-mediated inflammatory change, intraplaque neoangiogenesis/hemorrhage, hypoxia, and microcalcification, as potential morphologic indicators of stroke risk. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

PubMed

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.

Denture plaque--past and recent concerns.

PubMed

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.

[Is regression of atherosclerotic plaque possible?

PubMed

Páramo, José A; Civeira, Fernando

As it is well-known, a thrombus evolving into a disrupted/eroded atherosclerotic plaque causes most acute coronary syndromes. Plaque stabilization via reduction of the lipid core and/or thickening of the fibrous cap is one of the possible mechanisms accounted for the clinical benefits displayed by different anti-atherosclerotic strategies. The concept of plaque stabilization was developed to explain how lipid-lowering agents could decrease adverse coronary events without substantial modifications of the atherosclerotic lesion ('angiographic paradox'). A number of imaging modalities (vascular ultrasound and virtual histology, MRI, optical coherence tomography, positron tomography, etc.) are used for non-invasive assessment of atherosclerosis; most of them can identify plaque volume and composition beyond lumen stenosis. An 'aggressive' lipid-lowering strategy is able to reduce the plaque burden and the incidence of cardiovascular events; this may be attributable, at least in part, to plaque-stabilizing effects. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

Joint learning of ultrasonic backscattering statistical physics and signal confidence primal for characterizing atherosclerotic plaques using intravascular ultrasound.

PubMed

Sheet, Debdoot; Karamalis, Athanasios; Eslami, Abouzar; Noël, Peter; Chatterjee, Jyotirmoy; Ray, Ajoy K; Laine, Andrew F; Carlier, Stephane G; Navab, Nassir; Katouzian, Amin

2014-01-01

Intravascular Ultrasound (IVUS) is a predominant imaging modality in interventional cardiology. It provides real-time cross-sectional images of arteries and assists clinicians to infer about atherosclerotic plaques composition. These plaques are heterogeneous in nature and constitute fibrous tissue, lipid deposits and calcifications. Each of these tissues backscatter ultrasonic pulses and are associated with a characteristic intensity in B-mode IVUS image. However, clinicians are challenged when colocated heterogeneous tissue backscatter mixed signals appearing as non-unique intensity patterns in B-mode IVUS image. Tissue characterization algorithms have been developed to assist clinicians to identify such heterogeneous tissues and assess plaque vulnerability. In this paper, we propose a novel technique coined as Stochastic Driven Histology (SDH) that is able to provide information about co-located heterogeneous tissues. It employs learning of tissue specific ultrasonic backscattering statistical physics and signal confidence primal from labeled data for predicting heterogeneous tissue composition in plaques. We employ a random forest for the purpose of learning such a primal using sparsely labeled and noisy samples. In clinical deployment, the posterior prediction of different lesions constituting the plaque is estimated. Folded cross-validation experiments have been performed with 53 plaques indicating high concurrence with traditional tissue histology. On the wider horizon, this framework enables learning of tissue-energy interaction statistical physics and can be leveraged for promising clinical applications requiring tissue characterization beyond the application demonstrated in this paper. Copyright © 2013 Elsevier B.V. All rights reserved.

Improved Plaque Assay Identifies a Novel Anti-Chlamydia Ceramide Derivative with Altered Intracellular Localization

PubMed Central

Banhart, Sebastian; Saied, Essa M.; Martini, Andrea; Koch, Sophia; Aeberhard, Lukas; Madela, Kazimierz; Arenz, Christoph

2014-01-01

Chlamydia trachomatis is a medically important human pathogen causing different diseases, including trachoma, the leading cause of preventable blindness in developing countries, and sexually transmitted infections that can lead to infertility and ectopic pregnancies. There is no vaccine against C. trachomatis at present. Broad-spectrum antibiotics are used as standard therapy to treat the infection but have unwanted side effects, such as inducing persistent or recurring infections and affecting the host microbiome, necessitating the development of novel anti-Chlamydia therapies. Here, we describe the establishment of a robust, fast, and simple plaque assay using liquid overlay medium (LOM) for the identification of anti-Chlamydia compounds. Using the LOM plaque assay, we identified nitrobenzoxadiazole (NBD)-labeled 1-O-methyl-ceramide-C16 as a compound that efficiently inhibits C. trachomatis replication without affecting the viability of the host cell. Further detailed analyses indicate that 1-O-methyl-NBD-ceramide-C16 acts outside the inclusion. Thereby, 1-O-methyl-NBD-ceramide-C16 represents a lead compound for the development of novel anti-Chlamydia drugs and furthermore constitutes an agent to illuminate sphingolipid trafficking pathways in Chlamydia infections. PMID:25001308

Association between Carotid Plaque Characteristics and Cerebral White Matter Lesions: One-Year Follow-Up Study by MRI

PubMed Central

Kwee, Robert M.; Hofman, Paul A. M.; Gronenschild, Ed H. B. M.; van Oostenbrugge, Robert J.; Mess, Werner H.; Berg, Johannes W. M. ter.; Franke, Cees L.; Korten, Arthur G. G. C.; Meems, Bé J.; van Engelshoven, Jos M. A.; Wildberger, Joachim E.; Kooi, M. Eline

2011-01-01

Objective To prospectively assess the relation between carotid plaque characteristics and the development of new cerebral white matter lesions (WMLs) at MRI. Methods Fifty TIA/stroke patients with ipsilateral 30–69% carotid stenosis underwent MRI of the plaque at baseline. Total plaque volume and markers of vulnerability to thromboembolism (lipid-rich necrotic core [LRNC] volume, fibrous cap [FC] status, and presence of intraplaque hemorrhage [IPH]) were assessed. All patients also underwent brain MRI at baseline and after one year. Ipsilateral cerebral WMLs were quantified with a semiautomatic method. Results Mean WML volume significantly increased over a one-year period (6.52 vs. 6.97 mm3, P = 0.005). WML volume at baseline and WML progression did not significantly differ (P>0.05) between patients with 30–49% and patients with 50–69% stenosis. There was a significant correlation between total plaque volume and baseline ipsilateral WML volume (Spearman ρ = 0.393, P = 0.005). There was no significant correlation between total plaque volume and ipsilateral WML progression. There were no significant associations between LRNC volume and WML volume at baseline and WML progression. WML volume at baseline and WML progression did not significantly differ between patients with a thick and intact FC and patients with a thin and/or ruptured FC. WML volume at baseline and WML progression also did not significantly differ between patients with and without IPH. Conclusion The results of this study indicate that carotid plaque burden is significantly associated with WML severity, but that there is no causal relationship between carotid plaque vulnerability and the occurrence of WMLs. PMID:21347225

Atherosclerotic plaque delamination: Experiments and 2D finite element model to simulate plaque peeling in two strains of transgenic mice.

PubMed

Merei, Bilal; Badel, Pierre; Davis, Lindsey; Sutton, Michael A; Avril, Stéphane; Lessner, Susan M

2017-03-01

Finite element analyses using cohesive zone models (CZM) can be used to predict the fracture of atherosclerotic plaques but this requires setting appropriate values of the model parameters. In this study, material parameters of a CZM were identified for the first time on two groups of mice (ApoE -/- and ApoE -/- Col8 -/- ) using the measured force-displacement curves acquired during delamination tests. To this end, a 2D finite-element model of each plaque was solved using an explicit integration scheme. Each constituent of the plaque was modeled with a neo-Hookean strain energy density function and a CZM was used for the interface. The model parameters were calibrated by minimizing the quadratic deviation between the experimental force displacement curves and the model predictions. The elastic parameter of the plaque and the CZM interfacial parameter were successfully identified for a cohort of 11 mice. The results revealed that only the elastic parameter was significantly different between the two groups, ApoE -/- Col8 -/- plaques being less stiff than ApoE -/- plaques. Finally, this study demonstrated that a simple 2D finite element model with cohesive elements can reproduce fairly well the plaque peeling global response. Future work will focus on understanding the main biological determinants of regional and inter-individual variations of the material parameters used in the model. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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 < 0.01), while there was a negative correlation between EATV and the percentage of fibrous tissue (R (2) = 0.24, P < 0.01). Multivariate analysis revealed that an increased low-density lipoprotein cholesterol level (β = 0.15, P = 0.03) and 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.

Transmissible gastroenteritis virus: plaques and a plaque neutralization test.

PubMed Central

Thomas, F C; Dulac, G C

1976-01-01

A plaquing system and plaque neutralization test in porcine thyroid cells were used to study different transmissible gastroenteritis isolates and hemagglutinating encephalomyelitis virus. Among transmissible gastroenteritis virus isolates, plaque size varied considerably and mixed size ranges sometimes occurred. The most recently isolated viruses produced smaller plaques than the laboratory viruses or hemagglutinating encephalomyelitis virus. All transmissible gastroenteritis virus isolates reacted in the plaque neutralization test with a transmissible gastroenteritis virus antiserum which showed no activity against hemagglutinating encephalomyelitis virus. Plaque neutralization results both from experimentally infected pigs and following a field outbreak demonstrated the reliability of this test and its greater sensitivity than the conventional tube test. Images Fig. 1. PMID:187296

Intraplaque stretch in carotid atherosclerotic plaque--an effective biomechanical predictor for subsequent cerebrovascular ischemic events.

PubMed

Teng, Zhongzhao; Sadat, Umar; Wang, Wenkai; Bahaei, Nasim S; Chen, Shengyong; Young, Victoria E; Graves, Martin J; Gillard, Jonathan H

2013-01-01

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

COORDINATING, COMMUNICATING AND PERFORMING COMPLEX RESEARCH THAT IDENTIFIES VULNERABLE STREAM ECOSYSTEM IN THE MID-ATLANTIC REGION

EPA Science Inventory

The USEPA's Regional Vulnerability Assessment (ReVA) program was created to advance the scientific basis for protecting vulnerable ecosystems at a regional scale. As a first step, the ReVa program will coordinate, communicate and perform complex research that will identify vulner...

Near-infrared autofluorescence induced by intraplaque hemorrhage and heme degradation as marker for high-risk atherosclerotic plaques.

PubMed

Htun, Nay Min; Chen, Yung Chih; Lim, Bock; Schiller, Tara; Maghzal, Ghassan J; Huang, Alex L; Elgass, Kirstin D; Rivera, Jennifer; Schneider, Hans G; Wood, Bayden R; Stocker, Roland; Peter, Karlheinz

2017-07-13

Atherosclerosis is a major cause of mortality and morbidity, which is mainly driven by complications such as myocardial infarction and stroke. These complications are caused by thrombotic arterial occlusion localized at the site of high-risk atherosclerotic plaques, of which early detection and therapeutic stabilization are urgently needed. Here we show that near-infrared autofluorescence is associated with the presence of intraplaque hemorrhage and heme degradation products, particularly bilirubin by using our recently created mouse model, which uniquely reflects plaque instability as seen in humans, and human carotid endarterectomy samples. Fluorescence emission computed tomography detecting near-infrared autofluorescence allows in vivo monitoring of intraplaque hemorrhage, establishing a preclinical technology to assess and monitor plaque instability and thereby test potential plaque-stabilizing drugs. We suggest that near-infrared autofluorescence imaging is a novel technology that allows identification of atherosclerotic plaques with intraplaque hemorrhage and ultimately holds promise for detection of high-risk plaques in patients.Atherosclerosis diagnosis relies primarily on imaging and early detection of high-risk atherosclerotic plaques is important for risk stratification of patients and stabilization therapies. Here Htun et al. demonstrate that vulnerable atherosclerotic plaques generate near-infrared autofluorescence that can be detected via emission computed tomography.

Comparison of red autofluorescing plaque and disclosed plaque-a cross-sectional study.

PubMed

Volgenant, Catherine M C; Fernandez Y Mostajo, Mercedes; Rosema, Nanning A M; van der Weijden, Fridus A; Ten Cate, Jacob M; van der Veen, Monique H

2016-12-01

The aim of this cross-sectional study was to assess the correlation between dental plaque scores determined by the measurement of red autofluorescence or by visualization with a two-tone solution. Clinical photographs were used for this study. Overnight plaque from the anterior teeth of 48 participants was assessed for red fluorescence on photographs (taken with a QLF-camera) using a modified Quigley & Hein (mQH) index. A two-tone disclosing solution was applied. Total disclosed plaque was clinically assessed using the mQH index. In addition, total and blue disclosed plaque was scored on clinical photographs using the mQH index. A strong correlation was observed between the total disclosed plaque scored on photographs and the clinical scores (r = 0.70 at site level; r = 0.88 at subject level). The correlation between red fluorescent plaque and total plaque, as assessed on the photographs, was moderate to strong and significant (r = 0.50 at the site level; r = 0.70 at the subject level), with the total plaque scores consistently higher than the red fluorescent plaque scores. The correlation between red fluorescent plaque and blue disclosed plaque was weak to moderate and significant (r = 0.30 at the site level; r = 0.50 at the subject level). Plaque, as scored on white-light photographs, corresponds well with clinically assessed plaque. A weak to moderate correlation between red fluorescing plaque and total disclosed plaque or blue disclosed plaque was found. What at present is considered to be matured dental plaque, which appears blue following the application of a two-tone disclosing solution, is not in agreement with red fluorescent dental plaque assessment.

Identifying the "vulnerables" in biomedical research: the vox populis from the Tuskegee Legacy Project.

PubMed

Chiu, Christopher T; Katz, Ralph V

2011-01-01

This report presents, for the first time, findings on the vox populis as to who constitutes the "vulnerables in biomedical research" The 3-City Tuskegee Legacy Project (TLP) study used the TLP questionnaire as administered via random-digit-dial telephone interviews to 1162 adult Black people, non-Hispanic White people, and two Puerto Rican (PR) Hispanic groups: Mainland United States and San Juan (SJ) in three cities. The classification schema was based upon respondents' answers to an open-ended question asking which groups of people were the most vulnerable when participating in biomedical research. Subjects provided 749 valid open-ended responses, which were grouped into 29 direct response categories, leading to a four-tier classification schema for vulnerability traits. Tier 1, the summary tier, had five vulnerability categories: (1) Race/ ethnicity; (2) Age; (3) SES; (4) Health; and, (5) Gender. Black people and Mainland United States PR Hispanics most frequently identified Race/Ethnicity as a vulnerability trait (42.1 percent of Black people and 42.6 percent of Mainland United States. PR Hispanics versus 15.4 percent of White people and 16.7 percent of SJ R Hispanics) (P < 0.007), while White people and SJ PR Hispanics most frequently identified Age (48.3 percent and 29.2 percent) as a vulnerability trait. The response patterns on "who was vulnerable" were similar for the two minority groups (Black people and Mainland US PR Hispanics), and notably different from the response patterns of the two majority groups (White people and SJ PR Hispanics). Further, the vox populis definition of vulnerables differed from the current official definitions as used by the U.S. federal government.

Symptomatic and asymptomatic carotid artery plaque

PubMed Central

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

2011-01-01

Carotid atherosclerotic plaques represent both stable and unstable atheromatous lesions. Atherosclerotic plaques that are prone to rupture owing to their intrinsic composition such as a large lipid core, thin fibrous cap and intraplaque hemorrhage are associated with subsequent thromboembolic ischemic events. At least 15–20% of all ischemic strokes are attributable to carotid artery atherosclerosis. Characterization of plaques may enhance the understanding of natural history and ultimately the treatment of atherosclerotic disease. MRI of carotid plaque and embolic signals during transcranial Doppler have identified features beyond luminal stenosis that are predictive of future transient ischemic attacks and stroke. The value of specific therapies to prevent stroke in symptomatic and asymptomatic patients with severe carotid artery stenosis are the subject of current research and analysis of recently published clinical trials that are discussed in this article. PMID:21985544

Characterization of coronary plaques with combined use of intravascular ultrasound, virtual histology and optical coherence tomography

PubMed Central

Sánchez-Elvira, Guillermo; Coma-Canella, Isabel; Artaiz, Miguel; Páramo, José Antonio; Barba, Joaquín; Calabuig, José

2010-01-01

According to post-mortem studies, luminal thrombosis occurs from plaque rupture, erosion and calcified nodules. In vivo studies have found thin cap fibroatheroma (TCFA) as the main vulnerable lesion, prone to rupture. Few data about other post-mortem lesions have been reported in vivo. Our main objective is to characterize in vivo the coronary plaques with intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT), in order to detect not only thin cap fibroatheroma (TCFA), but also other possible vulnerable lesions. The secondary objective is to correlate these findings with clinical and analytical data. Twenty-five patients (18 stable) submitted to coronary angiography were included in this pilot study. After angiography, the three vessels were studied (when possible) with IVUS-VH and OCT. Plaque characteristics were correlated with clinical and analytical data. Forty-six lesions were analyzed. IVUS-VH detected significant necrotic core in 15 (3 were definite TCFA). OCT detected TCFA in 10 lesions, erosion in 6, thrombus in 5 and calcified nodule in 8. Possible vulnerable lesion was found in 61% of stable and 57% of unstable patients. Erosions and calcified nodules were only found in stable patients. Those with significant necrotic core had higher body mass index (P=0.016), higher levels of hs-CRP (P=0.019) and triglycerides (P=0.040). The higher the levels of hs-CRP, the larger the size of the necrotic core (r=0.69, P=0.003). Lesions with characteristics of vulnerability were detected by IVUS-VH and OCT in more than 50% of stable and unstable coronary patients. A significant necrotic core was mainly correlated with higher hs-CRP. PMID:21977297

Subject-Specific Fully-Coupled and One-Way Fluid-Structure Interaction Models for Modeling of Carotid Atherosclerotic Plaques in Humans

PubMed Central

Tao, Xiaojuan; Gao, Peiyi; Jing, Lina; Lin, Yan; Sui, Binbin

2015-01-01

Background Hemodynamics play an important role in the development and progression of carotid atherosclerosis, and may be important in the assessment of plaque vulnerability. The aim of this study was to develop a system to assess the hemodynamics of carotid atherosclerotic plaques using subject-specific fluid-structure interaction (FSI) models based on magnetic resonance imaging (MRI). Material/Methods Models of carotid bifurcations (n=86 with plaques from 52 patients, n=14 normal carotids from 12 participants) were obtained at the Department of Radiology, Beijing Tian Tan Hospital between 2010 and 2013. The maximum von Mises stress, minimum pressure, and flow velocity values were assessed at the most stenotic site in patients, or at the carotid bifurcations in healthy volunteers. Results of one-way FSI were compared with fully-coupled FSI for the plaques of 19 randomly selected models. Results The maximum von Mises stress and the minimum pressure and velocity were significantly increased in the stenosis group compared with controls based on one-way FSI (all P<0.05). The maximum von Mises stress and the minimum pressure were significantly higher and the velocity was significantly lower based on fully coupled FSI compared with on-way FSI (all P<0.05). Although there were differences in numerical values, both methods were equivalent. The maximum von Mises stress of vulnerable plaques was significantly higher than stable plaques (P<0.001). The maximum von Mises stress of the group with fibrous cap defect was significantly higher than the group without fibrous cap defect (P=0.001). Conclusions The hemodynamics of atherosclerotic plaques can be assessed noninvasively using subject-specific models of FSI based on MRI. PMID:26510514

Correlations between gene expression highlight a different activation of ACE/TLR4/PTGS2 signaling in symptomatic and asymptomatic plaques in atherosclerotic patients.

PubMed

Ferronato, Silvia; Scuro, Alberto; Gomez-Lira, Macarena; Mazzucco, Sara; Olivato, Silvia; Turco, Alberto; Elisa, Orlandi; Malerba, Giovanni; Romanelli, Maria Grazia

2018-06-19

Inflammation has a key role and translates the effects of many known risk factors for the disease in atherosclerotic vulnerable plaques. Aiming to look into the elements that induce the development of either a vulnerable or stable atherosclerotic plaque, and considering that inflammation has a central role in the progression of lesions, we analyzed the expression of genes involved in the ACE/TLR4/PTGS2 signaling in carotid plaques of symptomatic and asymptomatic patients. Patients with internal carotid artery stenosis undergoing carotid endarterectomy at Verona University Hospital were included in this study. A total of 71 patients was considered for gene expression analysis (29 atherothrombotic stroke patients and 42 asymptomatic patients). Total RNA was extracted from the excised plaques and expression of PTGS2, ACE, TLR4, PTGER4, PTGER3, EPRAP and ACSL4 genes was analyzed by real-time PCR. The correlation between the pair of genes was studied by Spearman coefficient. From the analyzed genes, we did not observe any individual difference in gene expression but the network of co-expressed genes suggests a different activation of pathways in the two groups of plaques.

Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares.

PubMed

Östling, Gerd; Persson, Margaretha; Hedblad, Bo; Gonçalves, Isabel

2013-11-01

Grey scale median (GSM) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut-off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with Adobe Photoshop(®) and with Artery Measurement System (AMS) on duplex ultrasound images of 100 consecutive medium- to large-sized carotid plaques of the Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for Adobe Photoshop(®) and AMS, respectively. Mean difference was 20·45 (95% CI: 19·17-21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi-square test revealed a kappa value of 0·68 when studying quartiles of GSM. The intra-observer variability was 1·9% for AMS and 2·5% for Adobe Photoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Clinical prediction model to identify vulnerable patients in ambulatory surgery: towards optimal medical decision-making.

PubMed

Mijderwijk, Herjan; Stolker, Robert Jan; Duivenvoorden, Hugo J; Klimek, Markus; Steyerberg, Ewout W

2016-09-01

Ambulatory surgery patients are at risk of adverse psychological outcomes such as anxiety, aggression, fatigue, and depression. We developed and validated a clinical prediction model to identify patients who were vulnerable to these psychological outcome parameters. We prospectively assessed 383 mixed ambulatory surgery patients for psychological vulnerability, defined as the presence of anxiety (state/trait), aggression (state/trait), fatigue, and depression seven days after surgery. Three psychological vulnerability categories were considered-i.e., none, one, or multiple poor scores, defined as a score exceeding one standard deviation above the mean for each single outcome according to normative data. The following determinants were assessed preoperatively: sociodemographic (age, sex, level of education, employment status, marital status, having children, religion, nationality), medical (heart rate and body mass index), and psychological variables (self-esteem and self-efficacy), in addition to anxiety, aggression, fatigue, and depression. A prediction model was constructed using ordinal polytomous logistic regression analysis, and bootstrapping was applied for internal validation. The ordinal c-index (ORC) quantified the discriminative ability of the model, in addition to measures for overall model performance (Nagelkerke's R (2) ). In this population, 137 (36%) patients were identified as being psychologically vulnerable after surgery for at least one of the psychological outcomes. The most parsimonious and optimal prediction model combined sociodemographic variables (level of education, having children, and nationality) with psychological variables (trait anxiety, state/trait aggression, fatigue, and depression). Model performance was promising: R (2)  = 30% and ORC = 0.76 after correction for optimism. This study identified a substantial group of vulnerable patients in ambulatory surgery. The proposed clinical prediction model could allow healthcare

[Plaque segmentation of intracoronary optical coherence tomography images based on K-means and improved random walk algorithm].

PubMed

Wang, Guanglei; Wang, Pengyu; Han, Yechen; Liu, Xiuling; Li, Yan; Lu, Qian

2017-06-01

In recent years, optical coherence tomography (OCT) has developed into a popular coronary imaging technology at home and abroad. The segmentation of plaque regions in coronary OCT images has great significance for vulnerable plaque recognition and research. In this paper, a new algorithm based on K -means clustering and improved random walk is proposed and Semi-automated segmentation of calcified plaque, fibrotic plaque and lipid pool was achieved. And the weight function of random walk is improved. The distance between the edges of pixels in the image and the seed points is added to the definition of the weight function. It increases the weak edge weights and prevent over-segmentation. Based on the above methods, the OCT images of 9 coronary atherosclerotic patients were selected for plaque segmentation. By contrasting the doctor's manual segmentation results with this method, it was proved that this method had good robustness and accuracy. It is hoped that this method can be helpful for the clinical diagnosis of coronary heart disease.

Contrast-enhanced ultrasound imaging of intraplaque neovascularization and its correlation to plaque echogenicity in human carotid arteries atherosclerosis.

PubMed

Cattaneo, Mattia; Staub, Daniel; Porretta, Alessandra P; Gallino, Jeanne Marie; Santini, Paolo; Limoni, Costanzo; Wyttenbach, Rolf; Gallino, Augusto

2016-11-15

Currently the most widely accepted predictor of stroke risk in patients with carotid atherosclerosis is the degree of stenoses. Plaque echogenicity on ultrasound imaging (US) and intraplaque neovascularization (IPNV) are becoming recognized as factors of plaque vulnerability. Aim of the study was to investigate the correlation between the echogenicity of the carotid atherosclerosis by standard US and the degree of IPNV by contrast enhanced US (CEUS). We recruited 45 consecutive subjects with an asymptomatic ≥50% carotid artery stenoses. Carotid plaque echogenicity at standard US was visually graded according to Gray-Weale classification (GW) and measured by the grayscale median (GSM), a semi-automated measurement performed by Adobe Photoshop©. On CEUS imaging IPNV was graded by different point scales according to the visual appearance of contrast within the plaque as follows: CEUS_A (1=absent; 2=present); CEUS_B (increasing IPNV from 1 to 3); and CEUS_C (increasing IPNV from 0 to 3). The correlation between echogenicity by GW and IPNV grading was as follows: CEUS_B (-0.130 p .423), CEUS_C (-0.108, p .509), CEUS_A (0.021, p .897). The correlation between echogenicity by GSM measurement and IPNV was as follows: using a CEUS_A (-0.125, p .444), CEUS_C (-0.021, p .897) (0.005, p .977). No correlation was found statistically significant. Our results display that there is no significant correlation between plaque echogenicity and IPNV. The small sample number and the multifaceted pathophysiology of the atherosclerotic plaque may explain the absence of statistically significantly correlation. Curtailing vulnerability explanation to either IPNV or echolucency may be misleading. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Macrophage activation by heparanase is mediated by TLR-2 and TLR-4 and associates with plaque progression.

PubMed

Blich, Miry; Golan, Amnon; Arvatz, Gil; Sebbag, Anat; Shafat, Itay; Sabo, Edmond; Cohen-Kaplan, Victoria; Petcherski, Sirouch; Avniel-Polak, Shani; Eitan, Amnon; Hammerman, Haim; Aronson, Doron; Axelman, Elena; Ilan, Neta; Nussbaum, Gabriel; Vlodavsky, Israel

2013-02-01

Factors and mechanisms that activate macrophages in atherosclerotic plaques are incompletely understood. We examined the capacity of heparanase to activate macrophages. Highly purified heparanase was added to mouse peritoneal macrophages and macrophage-like J774 cells, and the levels of tumor necrosis factor-α, matrix metalloproteinase-9, interlukin-1, and monocyte chemotactic protein-1 were evaluated by ELISA. Gene expression was determined by RT-PCR. Cells collected from Toll-like receptor-2 and Toll-like receptor-4 knockout mice were evaluated similarly. Heparanase levels in the plasma of patients with acute myocardial infarction, stable angina, and healthy subjects were determined by ELISA. Immunohistochemistry was applied to detect the expression of heparanase in control specimens and specimens of patients with stable angina or acute myocardial infarction. Addition or overexpression of heparanase variants resulted in marked increase in tumor necrosis factor-α, matrix metalloproteinase-9, interlukin-1, and monocyte chemotactic protein-1 levels. Mouse peritoneal macrophages harvested from Toll-like receptor-2 or Toll-like receptor-4 knockout mice were not activated by heparanase. Plasma heparanase level was higher in patients with acute myocardial infarction, compared with patients with stable angina and healthy subjects. Pathologic coronary specimens obtained from vulnerable plaques showed increased heparanase staining compared with specimens of stable plaque and controls. Heparanase activates macrophages, resulting in marked induction of cytokine expression associated with plaque progression toward vulnerability.

Detection and characterization of atherosclerotic plaques by Raman probe spectroscopy and optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Matthäus, Christian; Dochow, Sebastian; Egodage, Kokila D.; Schie, Iwan; Romeike, Bernd F.; Brehm, Bernhard R.; Popp, Jürgen

2017-02-01

Visualization and characterization of inner arterial plaque depositions is of vital diagnostic interest. Established intravascular imaging techniques provide valuable morphological information, but cannot deliver information about the chemical composition of individual plaques. Probe based Raman spectroscopy offers the possibility for a biochemical characterization of atherosclerotic plaque formations during an intravascular intervention. From post mortem studies it is well known that the severity of a plaque and its stability are strongly correlated with its biochemical composition. Especially the identification of vulnerable plaques remains one of the most important and challenging aspects in cardiology. Thus, specific information about the composition of a plaque would greatly improve the risk assessment and management. Furthermore, knowledge about the composition can offer new therapeutic and medication strategies. Plaque calcifications as well as major lipid components such as cholesterol, cholesterol esters and triglycerides can be spectroscopically easily differentiated. Intravascular optical coherence tomography (OCT) is currently a prominent catheter based imaging technique for the localization and visualization of atherosclerotic plaque depositions. The high resolution of OCT with 10 to 15 µm allows for very detailed characterization of morphological features such as different plaque formations, thin fibrous caps and accurate measurements of lesion lengths. In combination with OCT imaging the obtained spectral information can provide substantial information supporting on on-site diagnosis of various plaque types and therefor an improved risk assessment. The potential and feasibility of combining OCT with Raman spectroscopy is demonstrated on excised plaque samples, as well as under in vivo conditions. Acknowledgements: Financial support from the Carl Zeiss Foundation is greatly acknowledged.

Application of the gingival contour plaque index: six-month plaque and gingivitis study.

PubMed

Scherl, Dale S; Bork, Kim; Coffman, Lori; Lowry, Stephen R; VanCleave, Misty

2009-01-01

The Gingival Contour Plaque Index (GCPI) is a recently introduced and validated method of measuring plaque accumulation in dogs. It focuses on plaque accumulated along the gingival margin. Plaque accumulation in this area leads to gingival inflammation and, potentially, periodontitis. A 6-month plaque and gingivitis study was conducted to demonstrate the clinical research application of the GCPI, and to ensure that documented quantification of plaque-reducing efficacy could be related to a reduction in gingivitis. Advantages of the GCPI method are the ability to quantify plaque accumulation in an awake dog with fewer research personnel and more efficient time usage.

Identifying Vulnerabilities and Hardening Attack Graphs for Networked Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saha, Sudip; Vullinati, Anil K.; Halappanavar, Mahantesh

We investigate efficient security control methods for protecting against vulnerabilities in networked systems. A large number of interdependent vulnerabilities typically exist in the computing nodes of a cyber-system; as vulnerabilities get exploited, starting from low level ones, they open up the doors to more critical vulnerabilities. These cannot be understood just by a topological analysis of the network, and we use the attack graph abstraction of Dewri et al. to study these problems. In contrast to earlier approaches based on heuristics and evolutionary algorithms, we study rigorous methods for quantifying the inherent vulnerability and hardening cost for the system. Wemore » develop algorithms with provable approximation guarantees, and evaluate them for real and synthetic attack graphs.« less

Bacterial Diversity in Human Subgingival Plaque

PubMed Central

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

2001-01-01

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

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

NASA Astrophysics Data System (ADS)

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 (p<0.05). Moderate correlations showed between clinical plaque and red fluorescence plaque (r=0.62 dentist, r=0.55 computer). The best agreement was observed when disclosing plaque threshold at level 2, for both dentist evaluation (sensitivity 71.1%, specificity 67.7%, accuracy 70.2%) and computer classification (sensitivity 68.4%, specificity 62.9%, accuracy 67.1%). Given the correlation with clinical diagnosis, red fluorescence imaging shows its potential for providing an objective and promising method for proper oral hygiene assessment.

Plaque levels of patients with fixed orthodontic appliances measured by digital plaque image analysis.

PubMed

Klukowska, Malgorzata; Bader, Annike; Erbe, Christina; Bellamy, Philip; White, Donald J; Anastasia, Mary Kay; Wehrbein, Heiner

2011-05-01

A digital plaque image analysis system was developed to objectively assess dental plaque formation and coverage in patients treated with fixed orthodontic appliances. The technique was used to assess plaque levels of 52 patients undergoing treatment with fixed appliances in the Department of Orthodontics at Johannes Gutenberg University in Mainz, Germany. Plaque levels ranged from 5.1% to 85.3% of the analyzed tooth areas. About 37% of the patients had plaque levels over 50% of the dentition, but only 10% exhibited plaque levels below 15% of tooth coverage. The mean plaque coverage was 41.9% ± 18.8%. Plaque was mostly present along the gum line and around the orthodontic brackets and wires. The digital plaque image analysis system might provide a convenient quantitative technique to assess oral hygiene in orthodontic patients with multi-bracket appliances. Plaque coverage in orthodontic patients is extremely high and is 2 to 3 times higher than levels observed in high plaque-forming adults without appliances participating in clinical studies of the digital plaque image analysis system. Improved hygiene, chemotherapeutic regimens, and compliance are necessary in these patients. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2012-11-01

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

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

PubMed

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

Quantitative colorimetry of atherosclerotic plaque using the L*a*b* color space during angioscopy for the detection of lipid cores underneath thin fibrous caps.

PubMed

Ishibashi, Fumiyuki; Yokoyama, Shinya; Miyahara, Kengo; Dabreo, Alexandra; Weiss, Eric R; Iafrati, Mark; Takano, Masamichi; Okamatsu, Kentaro; Mizuno, Kyoichi; Waxman, Sergio

2007-12-01

Yellow plaques seen during angioscopy are thought to represent lipid cores underneath thin fibrous caps (LCTCs) and may be indicative of vulnerable sites. However, plaque color assessment during angioscopy has been criticized because of its qualitative nature. The purpose of the present study was to test the ability of a quantitative colorimetric system to measure yellow color intensity of atherosclerotic plaques during angioscopy and to characterize the color of LCTCs. Using angioscopy and a quantitative colorimetry system based on the L*a*b* color space [L* describes brightness (-100 to +100), b* describes blue to yellow (-100 to +100)], the optimal conditions for measuring plaque color were determined in three flat standard color samples and five artificial plaque models in cylinder porcine carotid arteries. In 88 human tissue samples, the colorimetric characteristics of LCTCs were then evaluated. In in-vitro samples and ex-vivo plaque models, brightness L* between 40 and 80 was determined to be optimal for acquiring b* values, and the variables unique to angioscopy in color perception did not impact b* values after adjusting for brightness L* by manipulating light or distance. In ex-vivo human tissue samples, b* value >/=23 (35.91 +/- 8.13) with L* between 40 and 80 was associated with LCTCs (fibrous caps <100 mum). Atherosclerotic plaque color can be consistently measured during angioscopy with quantitative colorimetry. High yellow color intensity, determined by this system, was associated with LCTCs. Quantitative colorimetry during angioscopy may be used for detection of LCTCs, which may be markers of vulnerability.

Plaque surface irregularity and calcification length within carotid plaque predict secondary events in patients with coronary artery disease.

PubMed

Nonin, Shinichi; Iwata, Shinichi; Sugioka, Kenichi; Fujita, Suwako; Norioka, Naoki; Ito, Asahiro; Nakagawa, Masashi; Yoshiyama, Minoru

2017-01-01

Although comprehensive risk factor modification is recommended, a uniform management strategy does not necessarily prevent secondary events in patients with coronary artery disease (CAD). Therefore, identification of high-risk patients who may benefit from more intensive interventions may improve prognosis. Carotid ultrasound can reliably identify systemic atherosclerosis, and carotid plaque and intima-media thickness (IMT) are known independent risk factors for CAD. However, it is unclear whether findings on carotid ultrasound can improve prediction of secondary CAD events. The study population comprised 146 consecutive patients with CAD (mean age, 66 ± 9 years; 126 with angina pectoris, 20 with acute myocardial infarction). IMT, plaque score, plaque area, plaque surface irregularity, and calcification length (calculated by summing the calcified lesions within each plaque accompanied by acoustic shadow) were measured at baseline. Patients were followed for 10 years to ascertain secondary CAD events defined as hard major adverse cardiovascular events (MACE; cardiac death and acute myocardial infarction) and as total MACE (hard MACE and angina pectoris with coronary revascularization). Multiple regression analysis demonstrated that calcification length (p < 0.05) and plaque surface irregularity (p < 0.01) remained independently associated with total MACE after adjustment for age, sex, diabetes mellitus, dyslipidemia, hypertension, chronic kidney disease, smoking, and multivessel CAD. These findings suggest that the combination of calcification length and plaque surface irregularity has additional value beyond traditional risk classification. Intensive intervention for these high-risk patients may avoid or delay progression of atherosclerosis towards secondary CAD events. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Ischemic Stroke Patients Demonstrate Increased Carotid Plaque Microvasculature Compared to (Ocular) Transient Ischemic Attack Patients

PubMed Central

van Hoof, Raf H.M.; Schreuder, Floris H.B.M.; Nelemans, Patty; Truijman, Martine T.B.; van Orshoven, Narender P.; Schreuder, Tobien H.; Mess, Werner H.; Heeneman, Sylvia; van Oostenbrugge, Robert J.; Wildberger, Joachim E.; Kooi, M. Eline

2017-01-01

Background Patients with a recent ischemic stroke have a higher risk of recurrent stroke compared to (ocular) transient ischemic attack (TIA) patients. Plaque microvasculature is considered as a feature of plaque vulnerability and can be quantified with carotid dynamic contrast-enhanced MRI (DCE-MRI). The purpose of this cross-sectional study was to explore the association between plaque microvasculature and the type of recent cerebrovascular events in symptomatic patients with mild-to-moderate carotid stenosis. Methods A total of 87 symptomatic patients with a recent stroke (n = 35) or (ocular) TIA (n = 52) underwent carotid DCE-MRI examination. Plaque microvasculature was studied in the vessel wall and adventitia using DCE-MRI and the pharmacokinetic modeling parameter Ktrans. Statistical analysis was performed with logistic regression, correcting for associated clinical risk factors. Results The 75th percentile adventitial (OR 1.97, 95% CI 1.18–3.29) Ktrans was significantly associated with a recent ischemic stroke compared to (ocular) TIA in multivariate analysis, while clinical risk factors were not significantly associated with the type of event. Conclusions This study indicates a positive association of leaky plaque microvasculature with a recent ischemic stroke compared to (ocular) TIA. Prospective longitudinal studies are needed to investigate whether Ktrans or other plaque characteristics may serve as an imaging marker for predicting (the type of) future cerebrovascular events. PMID:28946147

Enzyme-Sensitive MR Imaging Targeting Myeloperoxidase Identifies Active Inflammation in Experimental Rabbit Atherosclerotic Plaques

PubMed Central

Ronald, John A.; Chen, John W.; Chen, Yuanxin; Hamilton, Amanda M.; Rodriguez, Elisenda; Reynolds, Fred; Hegele, Robert A.; Rogers, Kem A.; Querol, Manel; Bogdanov, Alexei; Weissleder, Ralph; Rutt, Brian K.

2009-01-01

Background Inflammation undermines the stability of atherosclerotic plaques, rendering them susceptible to acute rupture, the cataclysmic event that underlies clinical expression of this disease. Myeloperoxidase (MPO) is a central inflammatory enzyme secreted by activated macrophages, and is involved in multiple stages of plaque destabilization and patient outcome. We report here that a unique functional in vivo magnetic resonance (MR) agent can visualize MPO activity in atherosclerotic plaques in a rabbit model. Methods and Results We performed MR imaging of the thoracic aorta of New Zealand white (NZW) rabbits fed a cholesterol (n=11) or normal (n=4) diet up to 2 hours after injection of the MPO sensor bis-5HT-DTPA(Gd) (MPO(Gd)), the conventional agent, DTPA(Gd), or an MPO (Gd) analog, bis-tyr-DTPA(Gd), as controls. Delayed MPO(Gd) images (2 hour post injection) showed focal areas of increased contrast (>2-fold) in diseased wall, but not in normal wall (p=0.84), compared to both DTPA(Gd) (n=11; p<0.001) and bis-tyr-DTPA(Gd) (n=3; p<0.05). Biochemical assays confirmed that diseased wall possessed three-fold elevated MPO activity compared to normal wall (p<0.01). Areas detected by MPO(Gd) imaging co-localized and correlated with MPO-rich areas infiltrated by macrophages on histopathological evaluations (r=0.91, p<0.0001). While macrophages were the main source of MPO, not all macrophages secreted MPO, suggesting that distinct subpopulations contribute differently to atherogenesis and supporting our functional approach. Conclusions Our study represents a unique approach in the detection of inflammation in atherosclerotic plaques by examining macrophage function and the activity of an effector enzyme, to noninvasively provide both anatomic and functional information in vivo. PMID:19652086

WE-FG-207B-06: Plaque Composition Measurement with Dual Energy Computed Tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, C; Ding, H; Malkasian, S

Purpose: To investigate the feasibility of characterizing arterial plaque composition in terms of water, lipid and protein or calcium using dual energy computed tomography. Characterization of plaque composition can potentially help distinguish vulnerable from stable plaques. Methods: Simulations studies were performed by the CT simulator based on ASTRA tomography toolbox. The beam energy for dual energy images was selected to be 80 kVp and 135 kVp. The radiation dose and energy spectrum for the CT simulator were carefully calibrated with respect to a 320-slice CT scanner. A digital chest phantom was constructed using Matlab for calibration and plaque measurement. Puremore » water, lipid, protein or calcium was used for calibration and a mixture of different volume percentages of these materials were used for validation purposes. Non-calcified plaque was simulated using water, lipid and protein with volumetric percentage range of 35%∼65%, 5%∼60% and 5%∼40%, respectively. Calcified plaque was simulated using water, lipid and calcium with volumetric percentage range of 50%∼80%, 8%∼45% and 3%∼13%, respectively. We employed iterative sinogram processing (ISP) to reduce the beam hardening effect in the simulation to improve the decomposition results. Results: The simulated known composition and dual energy decomposition results were in good agreement. Water, lipid and protein (calcium) mixtures were decomposed into water, lipid and protein (calcium) contents. The RMS errors of volumetric percentage for the water, lipid and protein (non-calcified plaque) decomposition, as compared to known values, were estimated to be approximately 5.74%, 2.54%, and 0.95% respectively. The RMS errors of volumetric percentage for the water, lipid and Calcium (calcified plaque) decomposition, as compared to known values, were estimated to be approximately 7.4%, 8.64%, and 0.08% respectively. Conclusion: The results of this study suggest that the dual energy decomposition can

Endoplasmic reticulum stress in perivascular adipose tissue promotes destabilization of atherosclerotic plaque by regulating GM-CSF paracrine.

PubMed

Ying, Ru; Li, Sheng-Wei; Chen, Jia-Yuan; Zhang, Hai-Feng; Yang, Ying; Gu, Zhen-Jie; Chen, Yang-Xin; Wang, Jing-Feng

2018-04-18

Perivascular adipose tissue (PVAT) accelerates plaque progression and increases cardiovascular risk. We tested the hypothesis that PVAT contributed to plaque vulnerability and investigated whether endoplasmic reticulum stress (ER stress) in PVAT played an important role in vulnerable plaque. We transplanted thoracic aortic PVAT or subcutaneous adipose tissue as a control, from donor mice to carotid arteries of recipient apolipoprotein E deficient (apoE -/- ) mice after removing carotid artery collar placed for 6 weeks. Two weeks after transplantation, ER stress inhibitor 4-phenyl butyric acid (4-PBA) was locally administrated to the transplanted PVAT and then animals were euthanized after 4 weeks. Immunohistochemistry was performed to quantify plaque composition and neovascularization. Mouse angiogenesis antibody array kit was used to test the angiogenic factors produced by transplanted adipose tissue. In vitro tube formation assay, scratch wound migration assay and mouse aortic ring assay were used to assess the angiogenic capacity of supernatant of transplanted PVAT. Ultrastructural detection by transmission electron microscopy showed transplanted PVAT was a mixed population of white and brown adipocytes with abundant mitochondria. Transplanted PVAT increased the intraplaque macrophage infiltration, lipid core, intimal and vasa vasorum neovascularization and MMP2/9 expression in plaque while decreased smooth muscle cells and collagen in atherosclerotic plaque, which were restored by local 4-PBA-treatment. Antibody array analysis showed that 4-PBA reduced several angiogenic factors [Granulocyte Macrophage Colony Stimulating Factor (GM-CSF), MCP-1, IL-6] secreted by PVAT. Besides, conditioned medium from 4-PBA treated-PVAT inhibited tube formation and migration capacity of endothelial cells and ex vivo mouse aortic ring angiogenesis compared to conditioned medium from transplanted PVAT. mRNA expression and protein levels of GM-CSF were markedly elevated in

[Carotid plaque assessment using inversion recovery T1 weighted-3 dimensions variable refocus flip angle turbo spin echo sampling perfection with application optimized contrast using different angle evolutions black blood imaging].

PubMed

Inoue, Yuji; Yoneyama, Masami; Nakamura, Masanobu; Ozaki, Satoshi; Ito, Kenjiro; Hiura, Mikio

2012-01-01

Vulnerable plaque can be attributed to induction of ischemic symptoms and magnetic resonance imaging of carotid artery is valuable to detect the plaque. Magnetization prepared rapid acquisition with gradient echo (MPRAGE) method could detect hemorrhagic vulnerable plaque as high intensity signal; however, blood flow is not sufficiently masked by this method. The contrast for plaque in T1 weighted image (T1WI) could not be obtained sufficiently with black blood image (BBI) by sampling perfection with application optimized contrast using different angle evolutions (SPACE) method as turbo spin echo (TSE). In addition, an appearance of artifact by slow flow is a problem. Considering these controversial situations in plaque imaging, we examined the modified BBI inversion recovery (IR)-SPACE in which IR was added for SPACE method so that the contrast for plaque in T1WI was optimized. We investigated the application of this method in plaque imaging. As a result of phantom imaging, the contrast for plaque in T1WI was definitely obtained by choosing an appropriate inversion time (TI) for the corresponding repetition time. In clinical cases, blood flow was sufficiently masked by IR-SPACE method and the plaque imaging was clearly obtained in clinical cases to the same extent as MPRAGE method. Since BBI with IR-SPACE method was derived from both IR pulse and flow void effect, this method could obtain the blood flow masking effect definitely. The present study suggested that SPACE method might be applicable to estimate properties of carotid artery plaque.

Molecular analysis of 16S rRNA genes identifies potentially periodontal pathogenic bacteria and archaea in the plaque of partially erupted third molars.

PubMed

Mansfield, J M; Campbell, J H; Bhandari, A R; Jesionowski, A M; Vickerman, M M

2012-07-01

Small subunit rRNA sequencing and phylogenetic analysis were used to identify cultivable and uncultivable microorganisms present in the dental plaque of symptomatic and asymptomatic partially erupted third molars to determine the prevalence of putative periodontal pathogens in pericoronal sites. Template DNA prepared from subgingival plaque collected from partially erupted symptomatic and asymptomatic mandibular third molars and healthy incisors was used in polymerase chain reaction with broad-range oligonucleotide primers to amplify 16S rRNA bacterial and archaeal genes. Amplicons were cloned, sequenced, and compared with known nucleotide sequences in online databases to identify the microorganisms present. Two thousand three hundred two clones from the plaque of 12 patients carried bacterial sequences from 63 genera belonging to 11 phyla, including members of the uncultivable TM7, SR1, and Chloroflexi, and difficult-to-cultivate Synergistetes and Spirochaetes. Dialister invisus, Filifactor alocis, Fusobacterium nucleatum, Porphyromonas endodontalis, Prevotella denticola, Tannerella forsythia, and Treponema denticola, which have been associated with periodontal disease, were found in significantly greater abundance in pericoronal compared with incisor sites. Dialister invisus and F nucleatum were found in greater abundance in sites exhibiting clinical symptoms. The archaeal species, Methanobrevibacter oralis, which has been associated with severe periodontitis, was found in 3 symptomatic patients. These findings have provided new insights into the complex microbiota of pericoronitis. Several bacterial and archaeal species implicated in periodontal disease were recovered in greater incidence and abundance from the plaque of partially erupted third molars compared with incisors, supporting the hypothesis that the pericoronal region may provide a favored niche for periodontal pathogens in otherwise healthy mouths. Copyright © 2012 American Association of Oral and

Effect of rosuvastatin on atherosclerotic plaque stability: An intravascular ultrasound elastography study.

PubMed

Li, Zhaohuan; Wang, Lin; Hu, Xiaobo; Zhang, Pengfei; Chen, Yifei; Liu, Xinxin; Xu, Mingjun; Zhang, Yun; Zhang, Mei

2016-05-01

The present study aimed to investigate the effect of potent rosuvastatin therapy on plaque mechanical stabilization as seen on IVUSE. 14 purebred New Zealand rabbits were fed a high-cholesterol diet; the abdominal aorta endothelium was balloon-injured after 2 weeks; at week 13, 7 rabbits received rosuvastatin (1.5 mg/kg/day), and the other 7 received an equal volume of saline. IVUS images of abdominal aortas were acquired, and 2 consecutive frames near the end-diastole images in situ were used to construct an IVUS elastogram. Control rabbits showed a significant increase in shear strain (SS) and area strain (AS) in total plaques. The rosuvastatin group showed no change in SS and AS, but serum TG and LDL-C levels were reduced, with less lipid deposition, macrophage infiltration, production of proinflammatory cytokines and apoptosis in plaques. The changes in SS and AS from baseline between groups significantly differed (SS: 1.15 (1.96) % vs. -0.99 ± 2.83%, p = 0.013; AS: 1.25 (2.29) % vs. -1.67 ± 5.05%, p = 0.022). At follow-up, for controls, strain values were increased in the shoulder of eccentric plaques (SS: 2.66 ± 1.31% vs. 4.86 ± 1.93%, p = 0.016; AS: 4.45 ± 2.33% vs. 7.91 ± 2.74%, p = 0.009) but not the plaque body. Changes in SS and AS in the plaque shoulder differed between the control and rosuvastatin groups (SS: 2.20 ± 2.17% vs. -0.87 ± 3.31%, p = 0.028; AS: 2.10 (4.61) % vs. -2.75 ± 5.97%, p = 0.009). Rosuvastatin therapy in rabbits with atherosclerotic plaques led to less vulnerable plaque features. IVUSE is a very sensitive technique for detecting pharmacologically-induced mechanical changes in rabbit atherosclerotic plaques. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Urease and Dental Plaque Microbial Profiles in Children.

PubMed

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 P<0.001; One Year P = 0.0148), especially Haemophilus parainfluenzae. No association was observed between these bacteria and dental caries. Bacteria in the genus Leptotrichia were negatively associated with urease and positively associated with dental caries (Bonferroni P<0.001). Alkali production by urease 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.

Community analysis of dental plaque and endotracheal tube biofilms from mechanically ventilated patients.

PubMed

Marino, Poala J; Wise, Matt P; Smith, Ann; Marchesi, Julian R; Riggio, Marcello P; Lewis, Michael A O; Williams, David W

2017-06-01

Mechanically ventilated patients are at risk for developing ventilator-associated pneumonia, and it has been reported that dental plaque provides a reservoir of respiratory pathogens that may aspirate to the lungs and endotracheal tube (ETT) biofilms. For the first time, metataxonomics was used to simultaneously characterize the microbiome of dental plaque, ETTs, and non-directed bronchial lavages (NBLs) in mechanically ventilated patients to determine similarities in respective microbial communities and therefore likely associations. Bacterial 16S rRNA gene sequences from 34 samples of dental plaque, NBLs, and ETTs from 12 adult mechanically ventilated patients were analyzed. No significant differences in the microbial communities of these samples were evident. Detected bacteria were primarily oral species (e.g., Fusobacterium nucleatum, Streptococcus salivarius, Prevotella melaninogenica) with respiratory pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcuspneumoniae, and Haemophilus influenzae) also in high abundance. The high similarity between the microbiomes of dental plaque, NBLs, and ETTs suggests that the oral cavity is indeed an important site involved in microbial aspiration to the lower airway and ETT. As such, maintenance of good oral hygiene is likely to be highly important in limiting aspiration of bacteria in this vulnerable patient group. Copyright © 2017 Elsevier Inc. All rights reserved.

Using standard clinical assessments for home care to identify vulnerable populations before, during, and after disasters.

PubMed

van Solm, Alexandra I T; Hirdes, John P; Eckel, Leslie A; Heckman, George A; Bigelow, Philip L

Several studies have shown the increased vulnerability of and disproportionate mortality rate among frail community-dwelling older adults as a result of emergencies and disasters. This article will discuss the applicability of the Vulnerable Persons at Risk (VPR) and VPR Plus decision support algorithms designed based on the Resident Assessment Instrument-Home Care (RAI-HC) to identify the most vulnerable community-dwelling (older) adults. A sample was taken from the Ontario RAI-HC database by selecting unique home care clients with assessments closest to December 31, 2014 (N = 275,797). Statistical methods used include cross tabulation, bivariate logistic regression as well as Kaplan-Meier survival plotting and Cox proportional hazards ratios calculations. The VPR and VPR Plus algorithms, were highly predictive of mortality, long-term care admission and hospitalization in ordinary circumstances. This provides a good indication of the strength of the algorithms in identifying vulnerable persons at times of emergencies. Access to real-time person-level information of persons with functional care needs is a vital enabler for emergency responders in prioritizing and allocating resources during a disaster, and has great utility for emergency planning and recovery efforts. The development of valid and reliable algorithms supports the rapid identification and response to vulnerable community-dwelling persons for all phases of emergency management.

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

PubMed

Gaffar, A; Afflitto, J; Nabi, N

1997-10-01

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

Automatic segmentation of amyloid plaques in MR images using unsupervised SVM

PubMed Central

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

2011-01-01

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

Genetic susceptibility for Alzheimer disease neuritic plaque pathology.

PubMed

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

2013-09-01

While numerous genetic susceptibility loci have been identified for clinical Alzheimer disease (AD), it is important to establish whether these variants are risk factors for the underlying disease pathology, including neuritic plaques. To investigate whether AD susceptibility loci from genome-wide association studies affect neuritic plaque pathology and to additionally identify novel risk loci for this trait. Candidate analysis of single-nucleotide polymorphisms and genome-wide association study in a joint clinicopathologic cohort, including 725 deceased subjects from the Religious Orders Study and the Rush Memory and Aging Project (2 prospective, community-based studies), followed by targeted validation in an independent neuroimaging cohort, including 114 subjects from multiple clinical and research centers. A quantitative measure of neuritic plaque pathologic burden, based on assessments of silver-stained tissue averaged from multiple brain regions. Validation based on β-amyloid load by immunocytochemistry, and replication with fibrillar β-amyloid positron emission tomographic imaging with Pittsburgh Compound B or florbetapir. Besides the previously reported APOE and CR1 loci, we found that the ABCA7 (rs3764650; P = .02) and CD2AP (rs9349407; P = .03) AD susceptibility loci are associated with neuritic plaque burden. In addition, among the top results of our genome-wide association study, we discovered a novel variant near the amyloid precursor protein gene (APP, rs2829887) that is associated with neuritic plaques (P = 3.3 × 10-6). This polymorphism was associated with postmortem β-amyloid load as well as fibrillar β-amyloid in 2 independent cohorts of adults with normal cognition. These findings enhance understanding of AD risk factors by relating validated susceptibility alleles to increased neuritic plaque pathology and implicate common genetic variation at the APP locus in the earliest, presymptomatic stages of AD.

Urease and Dental Plaque Microbial Profiles in Children

PubMed Central

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

2015-01-01

Objective 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. Methods 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. Results 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 P<0.001; One Year P = 0.0148), especially Haemophilus parainfluenzae. No association was observed between these bacteria and dental caries. Bacteria in the genus Leptotrichia were negatively associated with urease and positively associated with dental caries (Bonferroni P<0.001). Conclusions Alkali production by urease 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. PMID:26418220

Actinic comedonal plaque.

PubMed

Eastern, J S; Martin, S

1980-12-01

Solitary plaques developed on the sun-exposed and damaged skin of five elderly, fair-skinned individuals. The lesions, erythematous to bluish confluent nodules and plaques with a cribriform appearance and comedone-like structures, presented a distinctive histologic picture of dilated, keratin-filled follicles within a matrix of amorphous, damaged collagen. We believe these cases demonstrate a distinct entity within the realm of actinic dermatoses, for which the name "actinic comedonal plaque" seems appropriate.

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

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

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

Environmental Health Related Socio-Spatial Inequalities: Identifying “Hotspots” of Environmental Burdens and Social Vulnerability

PubMed Central

Shrestha, Rehana; Flacke, Johannes; Martinez, Javier; van Maarseveen, Martin

2016-01-01

Differential exposure to multiple environmental burdens and benefits and their distribution across a population with varying vulnerability can contribute heavily to health inequalities. Particularly relevant are areas with high cumulative burdens and high social vulnerability termed as “hotspots”. This paper develops an index-based approach to assess these multiple burdens and benefits in combination with vulnerability factors at detailed intra-urban level. The method is applied to the city of Dortmund, Germany. Using non-spatial and spatial methods we assessed inequalities and identified “hotspot” areas in the city. We found modest inequalities burdening higher vulnerable groups in Dortmund (CI = −0.020 at p < 0.05). At the detailed intra-urban level, however, inequalities showed strong geographical patterns. Large numbers of “hotspots” exist in the northern part of the city compared to the southern part. A holistic assessment, particularly at a detailed local level, considering both environmental burdens and benefits and their distribution across the population with the different vulnerability, is essential to inform environmental justice debates and to mobilize local stakeholders. Locating “hotspot” areas at this detailed spatial level can serve as a basis to develop interventions that target vulnerable groups to ensure a health conducive equal environment. PMID:27409625

Identifying Novel Phenotypes of Vulnerability and Resistance to Activity-Based Anorexia in Adolescent Female Rats

PubMed Central

Barbarich-Marsteller, Nicole C.; Underwood, Mark D.; Foltin, Richard W.; Myers, Michael M.; Walsh, B. Timothy; Barrett, Jeffrey S.; Marsteller, Douglas A.

2018-01-01

Objective Activity-based anorexia is a translational rodent model that results in severe weight loss, hyperactivity, and voluntary self-starvation. The goal of our investigation was to identify vulnerable and resistant phenotypes of activity-based anorexia in adolescent female rats. Method Sprague-Dawley rats were maintained under conditions of restricted access to food (N = 64; or unlimited access, N = 16) until experimental exit, predefined as a target weight loss of 30–35% or meeting predefined criteria for animal health. Nonlinear mixed effects statistical modeling was used to describe wheel running behavior, time to event analysis was used to assess experimental exit, and a regressive partitioning algorithm was used to classify phenotypes. Results Objective criteria were identified for distinguishing novel phenotypes of activity-based anorexia, including a vulnerable phenotype that conferred maximal hyperactivity, minimal food intake, and the shortest time to experimental exit, and a resistant phenotype that conferred minimal activity and the longest time to experimental exit. Discussion The identification of objective criteria for defining vulnerable and resistant phenotypes of activity-based anorexia in adolescent female rats provides an important framework for studying the neural mechanisms that promote vulnerability to or protection against the development of self-starvation and hyperactivity during adolescence. Ultimately, future studies using these novel phenotypes may provide important translational insights into the mechanisms that promote these maladaptive behaviors characteristic of anorexia nervosa. PMID:23853140

Identifying novel phenotypes of vulnerability and resistance to activity-based anorexia in adolescent female rats.

PubMed

Barbarich-Marsteller, Nicole C; Underwood, Mark D; Foltin, Richard W; Myers, Michael M; Walsh, B Timothy; Barrett, Jeffrey S; Marsteller, Douglas A

2013-11-01

Activity-based anorexia is a translational rodent model that results in severe weight loss, hyperactivity, and voluntary self-starvation. The goal of our investigation was to identify vulnerable and resistant phenotypes of activity-based anorexia in adolescent female rats. Sprague-Dawley rats were maintained under conditions of restricted access to food (N = 64; or unlimited access, N = 16) until experimental exit, predefined as a target weight loss of 30-35% or meeting predefined criteria for animal health. Nonlinear mixed effects statistical modeling was used to describe wheel running behavior, time to event analysis was used to assess experimental exit, and a regressive partitioning algorithm was used to classify phenotypes. Objective criteria were identified for distinguishing novel phenotypes of activity-based anorexia, including a vulnerable phenotype that conferred maximal hyperactivity, minimal food intake, and the shortest time to experimental exit, and a resistant phenotype that conferred minimal activity and the longest time to experimental exit. The identification of objective criteria for defining vulnerable and resistant phenotypes of activity-based anorexia in adolescent female rats provides an important framework for studying the neural mechanisms that promote vulnerability to or protection against the development of self-starvation and hyperactivity during adolescence. Ultimately, future studies using these novel phenotypes may provide important translational insights into the mechanisms that promote these maladaptive behaviors characteristic of anorexia nervosa. Copyright © 2013 Wiley Periodicals, Inc.

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

PubMed

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) <30 HU. A 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 (P<0.001). All attenuated plaques contained LDA <30 HU in the portions without HDA. MDCT has the ability to demonstrate attenuated plaque as the combination of HDA (approximately 400 HU on average) and LDA <30 HU. The HDA can be differentiated from calcified plaque by its lower CT density value.

In vivo MRI-based simulation of fatigue process: a possible trigger for human carotid atherosclerotic plaque rupture.

PubMed

Huang, Yuan; Teng, Zhongzhao; Sadat, Umar; He, Jing; Graves, Martin J; Gillard, Jonathan H

2013-04-23

Atherosclerotic plaque is subjected to a repetitive deformation due to arterial pulsatility during each cardiac cycle and damage may be accumulated over a time period causing fibrous cap (FC) fatigue, which may ultimately lead to rupture. In this study, we investigate the fatigue process in human carotid plaques using in vivo carotid magnetic resonance (MR) imaging. Twenty seven patients with atherosclerotic carotid artery disease were included in this study. Multi-sequence, high-resolution MR imaging was performed to depict the plaque structure. Twenty patients were found with ruptured FC or ulceration and 7 without. Modified Paris law was used to govern crack propagation and the propagation direction was perpendicular to the maximum principal stress at the element node located at the vulnerable site. The predicted crack initiations from 20 patients with FC defect all matched with the locations of the in vivo observed FC defect. Crack length increased rapidly with numerical steps. The natural logarithm of fatigue life decreased linearly with the local FC thickness (R(2) = 0.67). Plaques (n=7) without FC defect had a longer fatigue life compared with those with FC defect (p = 0.03). Fatigue process seems to explain the development of cracks in FC, which ultimately lead to plaque rupture.

The impact of wall shear stress and pressure drop on the stability of the atherosclerotic plaque.

PubMed

Li, Zhi-Yong; Taviani, Valentina; Gillard, Jonathan H

2008-01-01

Rupture of vulnerable atheromatous plaque in the carotid and coronary arteries often leads to stroke and heart attack respectively. The mechanism of blood flow and plaque rupture in stenotic arteries is still not fully understood. A three dimensional rigid wall model was solved under steady state conditions and unsteady conditions by assuming a time-varying inlet velocity profile to investigate the relative importance of axial forces and pressure drops in arteries with asymmetric stenosis. Flow-structure interactions were investigated for the same geometry and the results were compared with those retrieved with the corresponding 2D cross-section structural models. The Navier-Stokes equations were used as the governing equations for the fluid. The tube wall was assumed hyperelastic, homogeneous, isotropic and incompressible. The analysis showed that the three dimensional behavior of velocity, pressure and wall shear stress is in general very different from that predicted by cross-section models. Pressure drop across the stenosis was found to be much higher than shear stress. Therefore, pressure may be the more important mechanical trigger for plaque rupture other than shear stress, although shear stress is closely related to plaque formation and progression.

Activation of activator protein 2 alpha by aspirin alleviates atherosclerotic plaque growth and instability in vivo

PubMed Central

Yang, Jing-Jing; Li, Peng; Wang, Fu; Liang, Wen-Jing; Ma, Hui; Chen, Yuan; Ma, Zhi-Min; Li, Quan-Zhong; Peng, Qi-Sheng; Zhang, Yun; Wang, Shuang-Xi

2016-01-01

Aims Aspirin has been used for the secondary prevention and treatment of cardiovascular disease for several decades. We investigated the roles of transcriptional factor activator protein 2α (AP-2α) in the beneficial effects of aspirin in the growth and vulnerability of atherosclerotic plaque. Methods and Results In mice deficient of apolipoprotein E (Apoe-/-), aspirin (20, 50 mg/kg/day) suppressed the progression of atherosclerosis in aortic roots and increased the plaque stability in carotid atherosclerotic plaques induced by collar-placement. In vivo lentivirus-mediated RNA interference of AP-2α reversed the inhibitory effects of aspirin on atherosclerosis in Apoe-/- mice. Mechanically, aspirin increased AP-2α phosphorylation and its activity, upregulated IkBα mRNA and protein levels, and reduced oxidative stress in cultured vascular smooth muscle cells. Furthermore, deficiency of AP-2α completely abolished aspirin-induced upregulation of IkBα levels and inhibition of oxidative stress in Apoe-/- mice. Clinically, conventional doses of aspirin increased AP-2α phosphorylation and IkBα protein expression in humans subjects. Conclusion Aspirin activates AP-2α to upregulate IkBα gene expression, resulting in attenuations of plaque development and instability in atherosclerosis. PMID:27391154

Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial.

PubMed

Liu, Ting; Maurovich-Horvat, Pál; Mayrhofer, Thomas; Puchner, Stefan B; Lu, Michael T; Ghemigian, Khristine; Kitslaar, Pieter H; Broersen, Alexander; Pursnani, Amit; Hoffmann, Udo; Ferencik, Maros

2018-02-01

Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm 3 , 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features.

In vivo serial MRI-based models and statistical methods to quantify sensitivity and specificity of mechanical predictors for carotid plaque rupture: location and beyond.

PubMed

Wu, Zheyang; Yang, Chun; Tang, Dalin

2011-06-01

the sensitivity and specificity of various risk indicators and offers the potential to identify the optimized predictor for plaque rupture using serial MRI with follow-up scan showing ulceration as the gold standard for method validation. While serial MRI data with actual rupture are hard to acquire, this single-case study suggests that combination of multiple predictors may provide potential improvement to existing plaque assessment schemes. With large-scale patient studies, this predictive modeling process may provide more solid ground for rupture predictor selection strategies and methods for image-based plaque vulnerability assessment.

Numerical observer for atherosclerotic plaque classification in spectral computed tomography

PubMed Central

Lorsakul, Auranuch; Fakhri, Georges El; Worstell, William; Ouyang, Jinsong; Rakvongthai, Yothin; Laine, Andrew F.; Li, Quanzheng

2016-01-01

Abstract. Spectral computed tomography (SCT) generates better image quality than conventional computed tomography (CT). It has overcome several limitations for imaging atherosclerotic plaque. However, the literature evaluating the performance of SCT based on objective image assessment is very limited for the task of discriminating plaques. We developed a numerical-observer method and used it to assess performance on discrimination vulnerable-plaque features and compared the performance among multienergy CT (MECT), dual-energy CT (DECT), and conventional CT methods. Our numerical observer was designed to incorporate all spectral information and comprised two-processing stages. First, each energy-window domain was preprocessed by a set of localized channelized Hotelling observers (CHO). In this step, the spectral image in each energy bin was decorrelated using localized prewhitening and matched filtering with a set of Laguerre–Gaussian channel functions. Second, the series of the intermediate scores computed from all the CHOs were integrated by a Hotelling observer with an additional prewhitening and matched filter. The overall signal-to-noise ratio (SNR) and the area under the receiver operating characteristic curve (AUC) were obtained, yielding an overall discrimination performance metric. The performance of our new observer was evaluated for the particular binary classification task of differentiating between alternative plaque characterizations in carotid arteries. A clinically realistic model of signal variability was also included in our simulation of the discrimination tasks. The inclusion of signal variation is a key to applying the proposed observer method to spectral CT data. Hence, the task-based approaches based on the signal-known-exactly/background-known-exactly (SKE/BKE) framework and the clinical-relevant signal-known-statistically/background-known-exactly (SKS/BKE) framework were applied for analytical computation of figures of merit (FOM

Identifying counties vulnerable to diabetes from obesity prevalence in the United States: a spatiotemporal analysis.

PubMed

Li, Xiao; Staudt, Amanda; Chien, Lung-Chang

2016-11-21

Clinical and epidemiological research has reported a strong association between diabetes and obesity. However, whether increased diabetes prevalence is more likely to appear in areas with increased obesity prevalence has not been thoroughly investigated in the United States (US). The Bayesian structured additive regression model was applied to identify whether counties with higher obesity prevalence are more likely clustered in specific regions in 48 contiguous US states. Prevalence data adopted the small area estimate from the Behavioral Risk Factor Surveillance System. Confounding variables like socioeconomic status adopted data were from the American Community Survey. This study reveals that an increased percentage of relative risk of diabetes was more likely to appear in Southeast, Northeast, Central and South regions. Of counties vulnerable to diabetes, 36.8% had low obesity prevalence, and most of them were located in the Southeast, Central, and South regions. The geographic distribution of counties vulnerable to diabetes expanded to the Southwest, West and Northern regions when obesity prevalence increased. This study also discloses that 7.4% of counties had the largest average in predicted diabetes prevalence compared to the other counties. Their average diabetes prevalence escalated from 8.7% in 2004 to 11.2% in 2011. This study not only identifies counties vulnerable to diabetes due to obesity, but also distinguishes counties in terms of different levels of vulnerability to diabetes. The findings can provide the possibility of establishing targeted surveillance systems to raise awareness of diabetes in those counties.

La pelade par plaques

PubMed Central

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.

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

PubMed

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.

Review of studies assessing plaque accumulation and gingival inflammation in dogs.

PubMed

Hennet, P

1999-03-01

Periodontal disease is difficult to measure objectively. Many indices measuring plaque accumulation and gingivitis have been designed for humans, the Silness and Löe plaque index and Turesky modification of the Quigley and Hein plaque index being examples of well-accepted systems. It may, however, be beneficial to consider new or modified measurement systems for dogs, and such veterinary modifications need to be supported and clearly identified. This article reviews the origins of clinical periodontal indices now in common use in studies that examine the effectiveness of oral hygiene products.

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

PubMed

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 < 0.001). There was a strong correlation between percent plaque components volumes calculated by plaque and those calculated by vessel volumes (fibrous; r = 0.927, P < 0.001, fibrofatty; r = 0.972, P < 0.001, necrotic core; r = 0.964, P < 0.001, dense calcium; r = 0.980, P < 0.001,). Plaque and vessel volumes correlated well to the overall plaque burden. For percent plaque component volume, plaque-based 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.

DECT evaluation of noncalcified coronary artery plaque

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ravanfar Haghighi, Rezvan; Chatterjee, S.; Tabin, Milo

2015-10-15

plaques are practically nonexistent, and microcalcification, as observed in histopathology, has to be taken into account to explain the nature of the observed (ρ{sub e}, Z{sub eff}) data. This also enables us to judge the composition of the plaque in terms of basic model which considers the plaque to be composed of fibres, lipids, and microcalcification. Conclusions: This simple and reliable method has the potential as an effective modality to investigate the composition of noncalcified coronary artery plaques and thus help in their characterization. In this inversion method, (ρ{sub e}, Z{sub eff}) of the scanned sample can be found by eliminating the effects of the CT machine and also by ensuring that the determination of the two unknowns (ρ{sub e}, Z{sub eff}) does not interfere with each other and the nature of the plaque can be identified in terms of a three component model.« less

Vulnerable Plaque

MedlinePlus

... Daily Conferences Fellowships and Residencies School of Perfusion Technology Education Resources Library & Learning Resource Center CME Resources THI Journal THI Cardiac Society Save the Date: International Symposium on Cardiovascular Regenerative ...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2009-01-01

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

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

PubMed

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.

The Nature of Iron Deposits Differs between Symptomatic and Asymptomatic Carotid Atherosclerotic Plaques

PubMed Central

Kopriva, David; Kisheev, Anastasye; Meena, Deiter; Pelle, Shaneen; Karnitsky, Max; Lavoie, Andrea; Buttigieg, Josef

2015-01-01

Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophages with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. The abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin. PMID:26606178

The nature of iron deposits differs between symptomatic and asymptomatic carotid atherosclerotic plaques

DOE PAGES

Kopriva, David; Kisheev, Anastasye; Meena, Deiter; ...

2015-11-25

Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophagesmore » with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R 2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. Moreover, the abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin.« less

The nature of iron deposits differs between symptomatic and asymptomatic carotid atherosclerotic plaques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kopriva, David; Kisheev, Anastasye; Meena, Deiter

Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophagesmore » with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R 2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. Moreover, the abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin.« less

Demographics and Characterization of 10,282 Randall Plaque-Related Kidney Stones

PubMed Central

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

2015-01-01

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

Identifying the world's most climate change vulnerable species: a systematic trait-based assessment of all birds, amphibians and corals.

PubMed

Foden, Wendy B; Butchart, Stuart H M; Stuart, Simon N; Vié, Jean-Christophe; Akçakaya, H Resit; Angulo, Ariadne; DeVantier, Lyndon M; Gutsche, Alexander; Turak, Emre; Cao, Long; Donner, Simon D; Katariya, Vineet; Bernard, Rodolphe; Holland, Robert A; Hughes, Adrian F; O'Hanlon, Susannah E; Garnett, Stephen T; Sekercioğlu, Cagan H; Mace, Georgina M

2013-01-01

Climate change will have far-reaching impacts on biodiversity, including increasing extinction rates. Current approaches to quantifying such impacts focus on measuring exposure to climatic change and largely ignore the biological differences between species that may significantly increase or reduce their vulnerability. To address this, we present a framework for assessing three dimensions of climate change vulnerability, namely sensitivity, exposure and adaptive capacity; this draws on species' biological traits and their modeled exposure to projected climatic changes. In the largest such assessment to date, we applied this approach to each of the world's birds, amphibians and corals (16,857 species). The resulting assessments identify the species with greatest relative vulnerability to climate change and the geographic areas in which they are concentrated, including the Amazon basin for amphibians and birds, and the central Indo-west Pacific (Coral Triangle) for corals. We found that high concentration areas for species with traits conferring highest sensitivity and lowest adaptive capacity differ from those of highly exposed species, and we identify areas where exposure-based assessments alone may over or under-estimate climate change impacts. We found that 608-851 bird (6-9%), 670-933 amphibian (11-15%), and 47-73 coral species (6-9%) are both highly climate change vulnerable and already threatened with extinction on the IUCN Red List. The remaining highly climate change vulnerable species represent new priorities for conservation. Fewer species are highly climate change vulnerable under lower IPCC SRES emissions scenarios, indicating that reducing greenhouse emissions will reduce climate change driven extinctions. Our study answers the growing call for a more biologically and ecologically inclusive approach to assessing climate change vulnerability. By facilitating independent assessment of the three dimensions of climate change vulnerability, our approach can

Identifying the World's Most Climate Change Vulnerable Species: A Systematic Trait-Based Assessment of all Birds, Amphibians and Corals

PubMed Central

Foden, Wendy B.; Butchart, Stuart H. M.; Stuart, Simon N.; Vié, Jean-Christophe; Akçakaya, H. Resit; Angulo, Ariadne; DeVantier, Lyndon M.; Gutsche, Alexander; Turak, Emre; Cao, Long; Donner, Simon D.; Katariya, Vineet; Bernard, Rodolphe; Holland, Robert A.; Hughes, Adrian F.; O’Hanlon, Susannah E.; Garnett, Stephen T.; Şekercioğlu, Çagan H.; Mace, Georgina M.

2013-01-01

Climate change will have far-reaching impacts on biodiversity, including increasing extinction rates. Current approaches to quantifying such impacts focus on measuring exposure to climatic change and largely ignore the biological differences between species that may significantly increase or reduce their vulnerability. To address this, we present a framework for assessing three dimensions of climate change vulnerability, namely sensitivity, exposure and adaptive capacity; this draws on species’ biological traits and their modeled exposure to projected climatic changes. In the largest such assessment to date, we applied this approach to each of the world’s birds, amphibians and corals (16,857 species). The resulting assessments identify the species with greatest relative vulnerability to climate change and the geographic areas in which they are concentrated, including the Amazon basin for amphibians and birds, and the central Indo-west Pacific (Coral Triangle) for corals. We found that high concentration areas for species with traits conferring highest sensitivity and lowest adaptive capacity differ from those of highly exposed species, and we identify areas where exposure-based assessments alone may over or under-estimate climate change impacts. We found that 608–851 bird (6–9%), 670–933 amphibian (11–15%), and 47–73 coral species (6–9%) are both highly climate change vulnerable and already threatened with extinction on the IUCN Red List. The remaining highly climate change vulnerable species represent new priorities for conservation. Fewer species are highly climate change vulnerable under lower IPCC SRES emissions scenarios, indicating that reducing greenhouse emissions will reduce climate change driven extinctions. Our study answers the growing call for a more biologically and ecologically inclusive approach to assessing climate change vulnerability. By facilitating independent assessment of the three dimensions of climate change vulnerability

Plaque disruption by coronary computed tomographic angiography in stable patients vs. acute coronary syndrome: a feasibility study.

PubMed

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, <50 HU) volume, and remodelling index. Plaques were qualitatively assessed for CTA features of 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 < 0.0001). Clinically stable patients commonly manifest plaques with features of 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.

Impact of Wall Shear Stress and Pressure Variation on the Stability of Atherosclerotic Plaque

NASA Astrophysics Data System (ADS)

Taviani, V.; Li, Z. Y.; Sutcliffe, M.; Gillard, J.

Rupture of vulnerable atheromatous plaque in the carotid and coronary arteries often leads to stroke and heart attack respectively. The mechanism of blood flow and plaque rupture in stenotic arteries is still not fully understood. A three dimensional rigid wall model was solved under steady and unsteady conditions assuming a time-varying inlet velocity profile to investigate the relative importance of axial forces and pressure drops in arteries with asymmetric stenosis. Flow-structure interactions were investigated for the same geometry and the results were compared with those retrieved with the corresponding one dimensional models. The Navier-Stokes equations were used as the governing equations for the fluid. The tube wall was assumed linearly elastic, homogeneous isotropic. The analysis showed that wall shear stress is small (less than 3.5%) with respect to pressure drop throughout the cycle even for severe stenosis. On the contrary, the three dimensional behavior of velocity, pressure and wall shear stress is in general very different from that predicted by one dimensional models. This suggests that the primary source of mistakes in one dimensional studies comes from neglecting the three dimensional geometry of the plaque. Neglecting axial forces only involves minor errors.

64Cu-Labeled Divalent Cystine Knot Peptide for Imaging Carotid Atherosclerotic Plaques.

PubMed

Jiang, Lei; Tu, Yingfeng; Kimura, Richard H; Habte, Frezghi; Chen, Hao; Cheng, Kai; Shi, Hongcheng; Gambhir, Sanjiv Sam; Cheng, Zhen

2015-06-01

The rupture of vulnerable atherosclerotic plaques that lead to stroke and myocardial infarction may be induced by macrophage infiltration and augmented by the expression of integrin αvβ3. Indeed, atherosclerotic angiogenesis may be a promising marker of inflammation. In this study, an engineered integrin αvβ3-targeting PET probe, (64)Cu-NOTA-3-4A, derived from a divalent knottin miniprotein was evaluated in a mouse model for carotid atherosclerotic plaques. Atherosclerotic plaques in BALB/C mice, maintained on a high-fat diet, were induced with streptozotocin injection and carotid artery ligation and verified by MR imaging. Knottin 3-4A was synthesized by solid-phase peptide synthesis chemistry and coupled to 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) before radiolabeling with (64)Cu. PET probe stability in mouse serum was evaluated. Mice with carotid atherosclerotic plaques were injected via the tail vein with (64)Cu-NOTA-3-4A or (18)F-FDG, followed by small-animal PET/CT imaging at different time points. Receptor targeting specificity of the probe was verified by coinjection of c(RGDyK) administered in molar excess. Subsequently, carotid artery dissection and immunofluorescence staining were performed to evaluate target expression. (64)Cu-NOTA-3-4A was synthesized in high radiochemical purity and yield and demonstrated molecular stability in both phosphate-buffered saline and mouse serum at 4 h. Small-animal PET/CT showed that (64)Cu-NOTA-3-4A accumulated at significantly higher levels in the neovasculature of carotid atherosclerotic plaques (7.41 ± 1.44 vs. 0.67 ± 0.23 percentage injected dose/gram, P < 0.05) than healthy or normal vessels at 1 h after injection. (18)F-FDG also accumulated in atherosclerotic lesions at 0.5 and 1 h after injection but at lower plaque-to-normal tissue ratios than (64)Cu-NOTA-3-4A. For example, plaque-to-normal carotid artery ratios for (18)F-FDG and (64)Cu-NOTA-3-4A at 1 h after injection were 3.75 and 14.71 (P < 0

GIS model for identifying urban areas vulnerable to noise pollution: case study

NASA Astrophysics Data System (ADS)

Bilaşco, Ştefan; Govor, Corina; Roşca, Sanda; Vescan, Iuliu; Filip, Sorin; Fodorean, Ioan

2017-04-01

The unprecedented expansion of the national car ownership over the last few years has been determined by economic growth and the need for the population and economic agents to reduce travel time in progressively expanding large urban centres. This has led to an increase in the level of road noise and a stronger impact on the quality of the environment. Noise pollution generated by means of transport represents one of the most important types of pollution with negative effects on a population's health in large urban areas. As a consequence, tolerable limits of sound intensity for the comfort of inhabitants have been determined worldwide and the generation of sound maps has been made compulsory in order to identify the vulnerable zones and to make recommendations how to decrease the negative impact on humans. In this context, the present study aims at presenting a GIS spatial analysis model-based methodology for identifying and mapping zones vulnerable to noise pollution. The developed GIS model is based on the analysis of all the components influencing sound propagation, represented as vector databases (points of sound intensity measurements, buildings, lands use, transport infrastructure), raster databases (DEM), and numerical databases (wind direction and speed, sound intensity). Secondly, the hourly changes (for representative hours) were analysed to identify the hotspots characterised by major traffic flows specific to rush hours. The validated results of the model are represented by GIS databases and useful maps for the local public administration to use as a source of information and in the process of making decisions.

Plaque autofluorescence as potential diagnostic targets for oral malodor

NASA Astrophysics Data System (ADS)

Lee, Eun-Song; Yim, Hyun-Kyung; Lee, Hyung-Suk; Choi, Jong-Hoon; Kwon, Ho-Keun; Kim, Baek-Il

2016-08-01

The aim of this study was to determine whether the degree of tongue and interdental plaque can be used to assess oral malodor by quantifying their fluorescence as detected using quantitative light-induced fluorescence (QLF) technology. Ninety-nine subjects who complained of oral malodor were included. The level of oral malodor was quantified using the organoleptic score (OLS) and the concentration of volatile sulfur compounds (VSCs). The fluorescence properties of tongue and interdental plaque were quantified as scores calculated by multiplying the intensity and area of fluorescence in QLF-digital images, and the combined plaque fluorescence (CPF) score was obtained by summing the scores for the two regions. The associations of the scores with malodor levels and the diagnostic accuracy of the CPF score were analyzed. The two plaque fluorescence scores and their combined score differed significantly with the level of oral malodor (p<0.001). The CPF score was moderately correlated with OLS (r=0.64) and VSC levels (r=0.54), and its area under the receiver operating characteristic curve was 0.77 for identifying subjects with definite oral malodor (OLS≥2). In conclusion, plaque fluorescence from tongue and interdental sites as detected using QLF technology can be used to assess the level of oral malodor.

Equipment - Apollo XI (Plaque) - MSC

NASA Image and Video Library

1969-07-07

S69-38749 (July 1969) --- Close-up view of the plaque which the Apollo 11 astronauts will leave behind on the moon in commemoration of the historic event. The plaque is made of stainless steel measuring nine by seven and five-eighths inches, and one-sixteenth inch thick. The plaque will be attached to the ladder on the landing gear strut on the descent stage of the Apollo 11 Lunar Module (LM). Covering the plaque during flight will be a thin sheet of stainless steel which will be removed on the lunar surface.

Effect of intraplaque angiogenesis to atherosclerotic rupture-prone plaque induced by high shear stress in rabbit model

PubMed Central

Qiu, Juhui; Lei, Daoxi; Hu, Jianjun; Yin, Tieying; Zhang, Kang; Yu, Donghong

2017-01-01

Abstract Atherosclerotic prone-rupture plaque is mainly localized in the region of the entrance to the stenosis with high shear stress and the reasons are largely unknown. Our hypothesis is that such a distribution of cells in atherosclerotic plaque may depend on the angiogenesis. Silastic collars induced regions of high shear stress (20.68 ± 5.27 dynes/cm2) in the upstream flow and low shear stress (12.25 ± 1.28 dynes/cm2) in the downstream flow in carotid arteries. Compared with the low shear stress region, plaques in the high shear stress region showed more intraplaque haemorrhaging, less collagen and higher apoptotic rates of vascular smooth muscle cells; endothelial cells (ECs) in the high shear stress region were characterized with integrity and high endothelial nitric oxide synthase (eNOS) expression (1570.3 ± 345.5% vs 172.9 ± 49.9%). The number of intraplaque microvessels is very high in the high shear stress region (15 ± 1.8 n/mm2 vs 3.5 ± 0.4 n/mm2), and the microvessels in the plaque show ECs were abnormal, with membrane blebs, intracytoplasmic vacuoles and leukocyte infiltration. Our current study reveals that the integrity of the endothelium and the vulnerability of atherosclerotic plaques are simultaneously localized in high shear stress regions, and we provide evidence for the first time that microvessels in the intraplaque maybe responsible for rupture-prone plaque formation in the high shear stress region. PMID:28798867

The dental plaque microbiome in health and disease.

PubMed

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

2013-01-01

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

The Dental Plaque Microbiome in Health and Disease

PubMed Central

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

2013-01-01

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

Automatic plaque characterization and vessel wall segmentation in magnetic resonance images of atherosclerotic carotid arteries

NASA Astrophysics Data System (ADS)

Adame, Isabel M.; van der Geest, Rob J.; Wasserman, Bruce A.; Mohamed, Mona; Reiber, Johan H. C.; Lelieveldt, Boudewijn P. F.

2004-05-01

Composition and structure of atherosclerotic plaque is a primary focus of cardiovascular research. In vivo MRI provides a meanse to non-invasively image and assess the morphological features of athersclerotic and normal human carotid arteries. To quantitatively assess the vulnerability and the type of plaque, the contours of the lumen, outer boundary of the vessel wall and plaque components, need to be traced. To achieve this goal, we have developed an automated contou detection technique, which consists of three consecutive steps: firstly, the outer boundary of the vessel wall is detected by means of an ellipse-fitting procedure in order to obtain smoothed shapes; secondly, the lumen is segnented using fuzzy clustering. Thre region to be classified is that within the outer vessel wall boundary obtained from the previous step; finally, for plaque detection we follow the same approach as for lumen segmentation: fuzzy clustering. However, plaque is more difficult to segment, as the pixel gray value can differ considerably from one region to another, even when it corresponds to the same type of tissue. That makes further processing necessary. All these three steps might be carried out combining information from different sequences (PD-, T2-, T1-weighted images, pre- and post-contrast), to improve the contour detection. The algorithm has been validated in vivo on 58 high-resolution PD and T1 weighted MR images (19 patients). The results demonstrate excellent correspondence between automatic and manual area measurements: lumen (r=0.94), outer (r=0.92), and acceptable for fibrous cap thickness (r=0.76).

Effects of plaque lengths on stent surface roughness.

PubMed

Syaifudin, Achmad; Takeda, Ryo; Sasaki, Katsuhiko

2015-01-01

The physical properties of the stent surface influence the effectiveness of vascular disease treatment after stent deployment. During the expanding process, the stent acquires high-level deformation that could alter either its microstructure or the magnitude of surface roughness. This paper constructed a finite element simulation to observe the changes in surface roughness during the stenting process. Structural transient dynamic analysis was performed using ANSYS, to identify the deformation after the stent is placed in a blood vessel. Two types of bare metal stents are studied: a Palmaz type and a Sinusoidal type. The relationship between plaque length and the changes in surface roughness was investigated by utilizing three different length of plaque; plaque length longer than the stent, shorter than the stent and the same length as the stent. In order to reduce computational time, 3D cyclical and translational symmetry was implemented into the FE model. The material models used was defined as a multilinear isotropic for stent and hyperelastic for the balloon, plaque and vessel wall. The correlation between the plastic deformation and the changes in surface roughness was obtained by intermittent pure tensile test using specimen whose chemical composition was similar to that of actual stent material. As the plastic strain is achieved from FE simulation, the surface roughness can be assessed thoroughly. The study found that the plaque size relative to stent length significantly influenced the critical changes in surface roughness. It was found that the length of stent which is equal to the plaque length was preferable due to the fact that it generated only moderate change in surface roughness. This effect was less influential to the Sinusoidal stent.

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

PubMed

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 < 0.0001). Yellow plaques in coronaries detected by angioscopy with quantitative 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.

Functional genomics identifies specific vulnerabilities in PTEN-deficient breast cancer.

PubMed

Tang, Yew Chung; Ho, Szu-Chi; Tan, Elisabeth; Ng, Alvin Wei Tian; McPherson, John R; Goh, Germaine Yen Lin; Teh, Bin Tean; Bard, Frederic; Rozen, Steven G

2018-03-22

-SSL patterns of activity in a large proportion of PTEN-deficient breast cancer cell lines and are potential specific vulnerabilities in PTEN-deficient breast cancer. Furthermore, the NUAK1 PTEN-SSL vulnerability identified by RNA interference techniques can be recapitulated and exploited using the small molecule kinase inhibitor HTH-01-015. Thus, NUAK1 inhibition may be an effective strategy for precision treatment of PTEN-deficient breast tumors.

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

PubMed

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.

A fast screening protocol for carotid plaques imaging using 3D multi-contrast MRI without contrast agent.

PubMed

Zhang, Na; Zhang, Lei; Yang, Qi; Pei, Anqi; Tong, Xiaoxin; Chung, Yiu-Cho; Liu, Xin

2017-06-01

To implement a fast (~15min) MRI protocol for carotid plaque screening using 3D multi-contrast MRI sequences without contrast agent on a 3Tesla MRI scanner. 7 healthy volunteers and 25 patients with clinically confirmed transient ischemic attack or suspected cerebrovascular ischemia were included in this study. The proposed protocol, including 3D T1-weighted and T2-weighted SPACE (variable-flip-angle 3D turbo spin echo), and T1-weighted magnetization prepared rapid acquisition gradient echo (MPRAGE) was performed first and was followed by 2D T1-weighted and T2-weighted turbo spin echo, and post-contrast T1-weighted SPACE sequences. Image quality, number of plaques, and vessel wall thicknesses measured at the intersection of the plaques were evaluated and compared between sequences. Average examination time of the proposed protocol was 14.6min. The average image quality scores of 3D T1-weighted, T2-weighted SPACE, and T1-weighted magnetization prepared rapid acquisition gradient echo were 3.69, 3.75, and 3.48, respectively. There was no significant difference in detecting the number of plaques and vulnerable plaques using pre-contrast 3D images with or without post-contrast T1-weighted SPACE. The 3D SPACE and 2D turbo spin echo sequences had excellent agreement (R=0.96 for T1-weighted and 0.98 for T2-weighted, p<0.001) regarding vessel wall thickness measurements. The proposed protocol demonstrated the feasibility of attaining carotid plaque screening within a 15-minute scan, which provided sufficient anatomical coverage and critical diagnostic information. This protocol offers the potential for rapid and reliable screening for carotid plaques without contrast agent. Copyright © 2016. Published by Elsevier Inc.

SU-E-T-635: Process Mapping of Eye Plaque Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huynh, J; Kim, Y

Purpose: To apply a risk-based assessment and analysis technique (AAPM TG 100) to eye plaque brachytherapy treatment of ocular melanoma. Methods: The role and responsibility of personnel involved in the eye plaque brachytherapy is defined for retinal specialist, radiation oncologist, nurse and medical physicist. The entire procedure was examined carefully. First, major processes were identified and then details for each major process were followed. Results: Seventy-one total potential modes were identified. Eight major processes (corresponding detailed number of modes) are patient consultation (2 modes), pretreatment tumor localization (11), treatment planning (13), seed ordering and calibration (10), eye plaque assembly (10),more » implantation (11), removal (11), and deconstruction (3), respectively. Half of the total modes (36 modes) are related to physicist while physicist is not involved in processes such as during the actual procedure of suturing and removing the plaque. Conclusion: Not only can failure modes arise from physicist-related procedures such as treatment planning and source activity calibration, but it can also exist in more clinical procedures by other medical staff. The improvement of the accurate communication for non-physicist-related clinical procedures could potentially be an approach to prevent human errors. More rigorous physics double check would reduce the error for physicist-related procedures. Eventually, based on this detailed process map, failure mode and effect analysis (FMEA) will identify top tiers of modes by ranking all possible modes with risk priority number (RPN). For those high risk modes, fault tree analysis (FTA) will provide possible preventive action plans.« less

Targetable vulnerabilities in T- and NK-cell lymphomas identified through preclinical models.

PubMed

Ng, Samuel Y; Yoshida, Noriaki; Christie, Amanda L; Ghandi, Mahmoud; Dharia, Neekesh V; Dempster, Joshua; Murakami, Mark; Shigemori, Kay; Morrow, Sara N; Van Scoyk, Alexandria; Cordero, Nicolas A; Stevenson, Kristen E; Puligandla, Maneka; Haas, Brian; Lo, Christopher; Meyers, Robin; Gao, Galen; Cherniack, Andrew; Louissaint, Abner; Nardi, Valentina; Thorner, Aaron R; Long, Henry; Qiu, Xintao; Morgan, Elizabeth A; Dorfman, David M; Fiore, Danilo; Jang, Julie; Epstein, Alan L; Dogan, Ahmet; Zhang, Yanming; Horwitz, Steven M; Jacobsen, Eric D; Santiago, Solimar; Ren, Jian-Guo; Guerlavais, Vincent; Annis, D Allen; Aivado, Manuel; Saleh, Mansoor N; Mehta, Amitkumar; Tsherniak, Aviad; Root, David; Vazquez, Francisca; Hahn, William C; Inghirami, Giorgio; Aster, Jon C; Weinstock, David M; Koch, Raphael

2018-05-22

T- and NK-cell lymphomas (TCL) are a heterogenous group of lymphoid malignancies with poor prognosis. In contrast to B-cell and myeloid malignancies, there are few preclinical models of TCLs, which has hampered the development of effective therapeutics. Here we establish and characterize preclinical models of TCL. We identify multiple vulnerabilities that are targetable with currently available agents (e.g., inhibitors of JAK2 or IKZF1) and demonstrate proof-of-principle for biomarker-driven therapies using patient-derived xenografts (PDXs). We show that MDM2 and MDMX are targetable vulnerabilities within TP53-wild-type TCLs. ALRN-6924, a stapled peptide that blocks interactions between p53 and both MDM2 and MDMX has potent in vitro activity and superior in vivo activity across 8 different PDX models compared to the standard-of-care agent romidepsin. ALRN-6924 induced a complete remission in a patient with TP53-wild-type angioimmunoblastic T-cell lymphoma, demonstrating the potential for rapid translation of discoveries from subtype-specific preclinical models.

A Simplified Technique to Measure Plaque on the Intaglio Surfaces of Complete Dentures.

PubMed

Almas, Khalid; Salameh, Ziad; Kutkut, Ahmad; Al Doubali, Ahmad

2015-04-01

The main aim of this study was to develop a simplified quantitative denture plaque index that could help dentists to motivate denture patients to maintain optimal oral hygiene. The secondary aim was to assess specific areas of dentures more prone to accumulate plaque and subjects' oral hygiene habits related to their dentures. One hundred subjects who wore maxillary and/or mandibular complete dentures for at least one year were included in the study as a powered sample. Fifteen females and 85 males, age range 45-75 years, were recruited. The study was carried out at King Saud University (KSU), College of Dentistry. A plaque disclosing solution was used to assess the plaque covered areas of denture. A quantitative percentage (10 x 10%) score index was developed by assessing plaque scores from digital images of intaglio surfaces of the dentures. The weighted kappa method was used to assess inter-examiner agreement in the main study. The new denture plaque index was identified as ASKD-DPI (Almas, Salameh, Kutkut, and Doubali-Denture Plaque Index). It ranged from 0 - 100%, and reflected the percentage of the intaglio surfaces of maxillary and mandibular complete dentures that contained plaque. It also classified quantitative percentages: 30 subjects ranged from 0 - 30% (low DPI), 50 subjects ranged from 31 - 70% (moderate DPI), and 20 subjects ranged from 71 - 100% (high DPI) denture plaque score. A simplified denture plaque index (ASKD-DPI) technique was developed and tested in this study. ASKD-DPI may be used for evaluating denture plaque scores, monitoring denture hygiene, and measuring compliance of patients regarding plaque control for complete dentures.

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

PubMed

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 <2 mm, from 2 mm to 3 mm, and >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.

Amoxicillin-resistant oral streptococci identified in dental plaque specimens from healthy Japanese adults.

PubMed

Masuda, Katsuhiko; Nemoto, Hirotoshi; Nakano, Kazuhiko; Naka, Shuhei; Nomura, Ryota; Ooshima, Takashi

2012-05-01

Infective endocarditis (IE) is known to be a life-threatening disease and invasive dental procedures are considered to be important factors. Oral amoxicillin (AMPC) is widely used for prophylaxis in patients with heart disorders who are at risk for IE. However, there is only limited information regarding the inhibition of oral bacteria by AMPC. Dental plaque specimens were obtained from 120 healthy Japanese adult subjects, then diluted and streaked onto selective medium for oral streptococci. The minimum inhibitory concentration (MIC) of AMPC was evaluated using a macro-dilution method by Clinical Laboratory Standard Institute (2006). Seven strains with an MIC of AMPC of 16μg/mL or more were isolated from 5 subjects. The bacterial species were confirmed by sequence analysis of 16S rRNA from each strain, which demonstrated that most were Streptococcus sanguinis, followed by Streptococcus oralis. Dental plaque specimens collected from these 5 subjects again after an interval of 2-3 months possessed no strains with an MIC of AMPC of 16μg/mL or more. These findings suggest that strains with a high MIC of AMPC are present in the oral cavities of Japanese adults, though they may be transient rather than inhabitants. Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Quantification of carotid artery plaque stability with multiple region of interest based ultrasound strain indices and relationship with cognition

NASA Astrophysics Data System (ADS)

Meshram, N. H.; Varghese, T.; Mitchell, C. C.; Jackson, D. C.; Wilbrand, S. M.; Hermann, B. P.; Dempsey, R. J.

2017-08-01

Vulnerability and instability in carotid artery plaque has been assessed based on strain variations using noninvasive ultrasound imaging. We previously demonstrated that carotid plaques with higher strain indices in a region of interest (ROI) correlated to patients with lower cognition, probably due to cerebrovascular emboli arising from these unstable plaques. This work attempts to characterize the strain distribution throughout the entire plaque region instead of being restricted to a single localized ROI. Multiple ROIs are selected within the entire plaque region, based on thresholds determined by the maximum and average strains in the entire plaque, enabling generation of additional relevant strain indices. Ultrasound strain imaging of carotid plaques, was performed on 60 human patients using an 18L6 transducer coupled to a Siemens Acuson S2000 system to acquire radiofrequency data over several cardiac cycles. Patients also underwent a battery of neuropsychological tests under a protocol based on National Institute of Neurological Disorders and Stroke and Canadian Stroke Network guidelines. Correlation of strain indices with composite cognitive index of executive function revealed a negative association relating high strain to poor cognition. Patients grouped into high and low cognition groups were then classified using these additional strain indices. One of our newer indices, namely the average L  -  1 norm with plaque (AL1NWP) presented with significantly improved correlation with executive function when compared to our previously reported maximum accumulated strain indices. An optimal combination of three of the new indices generated classifiers of patient cognition with an area under the curve (AUC) of 0.880, 0.921 and 0.905 for all (n  =  60), symptomatic (n  =  33) and asymptomatic patients (n  =  27) whereas classifiers using maximum accumulated strain indices alone provided AUC values of 0.817, 0.815 and 0

Quantification of carotid artery plaque stability with multiple region of interest based ultrasound strain indices and relationship with cognition.

PubMed

Meshram, N H; Varghese, T; Mitchell, C C; Jackson, D C; Wilbrand, S M; Hermann, B P; Dempsey, R J

2017-07-17

Vulnerability and instability in carotid artery plaque has been assessed based on strain variations using noninvasive ultrasound imaging. We previously demonstrated that carotid plaques with higher strain indices in a region of interest (ROI) correlated to patients with lower cognition, probably due to cerebrovascular emboli arising from these unstable plaques. This work attempts to characterize the strain distribution throughout the entire plaque region instead of being restricted to a single localized ROI. Multiple ROIs are selected within the entire plaque region, based on thresholds determined by the maximum and average strains in the entire plaque, enabling generation of additional relevant strain indices. Ultrasound strain imaging of carotid plaques, was performed on 60 human patients using an 18L6 transducer coupled to a Siemens Acuson S2000 system to acquire radiofrequency data over several cardiac cycles. Patients also underwent a battery of neuropsychological tests under a protocol based on National Institute of Neurological Disorders and Stroke and Canadian Stroke Network guidelines. Correlation of strain indices with composite cognitive index of executive function revealed a negative association relating high strain to poor cognition. Patients grouped into high and low cognition groups were then classified using these additional strain indices. One of our newer indices, namely the average L  -  1 norm with plaque (AL1NWP) presented with significantly improved correlation with executive function when compared to our previously reported maximum accumulated strain indices. An optimal combination of three of the new indices generated classifiers of patient cognition with an area under the curve (AUC) of 0.880, 0.921 and 0.905 for all (n  =  60), symptomatic (n  =  33) and asymptomatic patients (n  =  27) whereas classifiers using maximum accumulated strain indices alone provided AUC values of 0.817, 0.815 and 0

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

NASA Astrophysics Data System (ADS)

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.

Novel Approach for In Vivo Detection of Vulnerable Coronary Plaques using Molecular 3-T CMR Imaging with an Albumin-Binding Probe.

PubMed

Engel, Leif-Christopher; Landmesser, Ulf; Gigengack, Kevin; Wurster, Thomas; Manes, Constantina; Girke, Georg; Jaguszewski, Milosz; Skurk, Carsten; Leistner, David M; Lauten, Alexander; Schuster, Andreas; Hamm, Bernd; Botnar, Rene M; Makowski, Marcus R; Bigalke, Boris

2018-01-12

This study sought to investigate the potential of the noninvasive albumin-binding probe gadofosveset-enhanced cardiac magnetic resonance (GE-CMR) for detection of coronary plaques that can cause acute coronary syndromes (ACS). ACS are frequently caused by rupture or erosion of coronary plaques that initially do not cause hemodynamically significant stenosis and are therefore not detected by invasive x-ray coronary angiography (XCA). A total of 25 patients with ACS or symptoms of stable coronary artery disease underwent GE-CMR, clinically indicated XCA, and optical coherence tomography (OCT) within 24 h. GE-CMR was performed approximately 24 h following a 1-time application of gadofosveset-trisodium. Contrast-to-noise ratio (CNR) was quantified within coronary segments in comparison with blood signal. A total of 207 coronary segments were analyzed on GE-CMR. Segments containing a culprit lesion in ACS patients (n = 11) showed significant higher signal enhancement (CNR) following gadofosveset-trisodium application than segments without culprit lesions (n = 196; 6.1 [3.9 to 16.5] vs. 2.1 [0.5 to 3.5]; p < 0.001). GE-CMR was able to correctly identify culprit coronary lesions in 9 of 11 segments (sensitivity 82%) and correctly excluded culprit coronary lesions in 162 of 195 segments (specificity 83%). Additionally, segmented areas of thin-cap fibroatheroma (n = 22) as seen on OCT demonstrated significantly higher CNR than segments without coronary plaque or segments containing early atherosclerotic lesions (n = 185; 9.2 [3.3 to 13.7] vs. 2.1 [0.5 to 3.4]; p = 0.001). In this study, we demonstrated for the first time the noninvasive detection of culprit coronary lesions and thin-cap fibroatheroma of the coronary arteries in vivo by using GE-CMR. This method may represent a novel approach for noninvasive cardiovascular risk prediction. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

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

PubMed

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.

[Imprints of coronary plaque particles in the PTCA balloon surface during the dilatation processing].

PubMed

Werner, D; Behrend, D; Schmitz, K P; Urbaszek, W

1995-05-01

Seventy-six PTCA-balloons after coronary angioplasty were studied for superficial changes using scanning electron microscopy (SEM) after fixing in glutardialdehyde. Coronary plaque particles were identified on the balloon surface in 52 cases (68%). Twelve new and unused balloons were subjected to the same chemical treatment and SEM showed no imprints. The average length of the longest imprinted plaques was 128 +/- 201 microns and the average number of plaque particles per balloon was 4.9 +/- 2.7. The maximal dilatation pressure and the number of dilatations showed no influence on the impregnation of plaque particles. However, longer plaque imprints tended to occur under low dilatation pressure. Imprints of plaque particles were significantly higher in patients with low cholesterol (p = 0.0001) and low triglycerides (p = 0.0016). No correlation was seen between imprint length and lipid levels. Similarly, the different balloon materials (polyethylene, polyolefincopolymer) showed no significant differences with regard to plaque occurrence. The PTCA-balloons, plaque particles and six coronary plaques obtained after endatherectomy were subjected to energy dispersive x-ray analysis (EDX) under SEM as EDX reveals qualitative and quantitative information about the structural elements. Highly significant differences in calcium, sodium, phosphorus and silicon contents (p = 0.0000) between plaque particles and balloon surface were observed, owing to the absence of these in balloon material. Thus EDX offers additional advantages over SEM in that it clearly differentiates deformed balloon surface, plaque particle, and retained contrast medium. Plaque particles can be recovered from balloon surfaces after PTCA. Depending upon their size, they could lead to coronary spasm or microembolic phenomenon.

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

NASA Astrophysics Data System (ADS)

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.

Valsartan Promoting Atherosclerotic Plaque Stabilization by Upregulating Renalase: A Potential-Related Gene of Atherosclerosis.

PubMed

Zhou, Mingxue; Ma, Chao; Liu, Weihong; Liu, Hongxu; Wang, Ning; Kang, Qunfu; Li, Ping

2015-09-01

Renalase is a protein that can regulate sympathetic nerve activity by metabolizing catecholamines, while redundant catecholamines are thought to contribute to atherosclerosis (As). Catecholamine release can be facilitated by angiotensin (Ang) II by binding to Ang II type 1 (AT1) receptors. Valsartan, a special AT1 antagonist, can dilate blood vessels and reduce blood pressure, but it remained unclear whether valsartan can promote the stability of atherosclerotic plaque by affecting renalase. This study examined the tissue distribution of renalase in ApoE(-/-) mice fed with a high-fat diet and the effect of valsartan on expression of renalase. ApoE(-/-) mice were fed with a high-fat diet for 13 or 26 weeks. As a control, 10 C57BL mice were fed with a standard chow diet. After 13 weeks on the high-fat diet, the ApoE(-/-) mice were randomized (10 mice/group) and treated with valsartan, simvastatin, or distilled water (control group) for an additional 13 weeks accompanied by a high-fat diet. Knockout of ApoE caused a dramatic increase in expression of renalase in mice adipose tissue. With the disturbance of lipid metabolism induced by a high-fat diet, renalase expression decreased in the liver. Renalase can be expressed in smooth muscle cells and M2 macrophages in atherosclerotic plaque, and its expression gradually decreases in the fibrous cap during the transition from stable to vulnerable atherosclerotic plaque. Valsartan, an AT1 receptor antagonist, promotes the stabilization of atherosclerotic plaque by increasing the levels of renalase in serum and the expression of renalase in the fibrous cap of atherosclerotic plaque. It also reduces triglyceride levels in serum and increases the expression of renalase in the liver. Renalase may be a potential-related gene of lipid metabolism and As, and it may be the possible molecular target of valsartan to help stabilize atherosclerotic plaque. © The Author(s) 2015.

Topological Vulnerability Analysis

NASA Astrophysics Data System (ADS)

Jajodia, Sushil; Noel, Steven

Traditionally, network administrators rely on labor-intensive processes for tracking network configurations and vulnerabilities. This requires a great deal of expertise, and is error prone because of the complexity of networks and associated security data. The interdependencies of network vulnerabilities make traditional point-wise vulnerability analysis inadequate. We describe a Topological Vulnerability Analysis (TVA) approach that analyzes vulnerability dependencies and shows all possible attack paths into a network. From models of the network vulnerabilities and potential attacker exploits, we compute attack graphs that convey the impact of individual and combined vulnerabilities on overall security. TVA finds potential paths of vulnerability through a network, showing exactly how attackers may penetrate a network. From this, we identify key vulnerabilities and provide strategies for protection of critical network assets.

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

PubMed

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

Plaquing procedure for infectious hematopoietic necrosis virus

USGS Publications Warehouse

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.

Special Operations Soldier With Cardiac Family History: Use of CCTA and Protein Biomarker Testing to Detect Risk of Heart Attack From Noncalcified Plaque.

PubMed

Singh, Millee; Kroman, Anne; Singh, Juile; Tariq, Hassan; Amin, Shetal; Morales-Pablon, Cesar Alberto; Cahill, Kristina Vanessa; Harrison, Eric Edward

2015-01-01

We sought to characterize the risk of a heart attack in a 48-year-old asymptomatic US Special Operations Command (SOCOM) Soldier without known coronary artery disease (CAD). CAD continues to be a leading cause of morbidity and mortality among most age groups in the United States. Much research is dedicated to establishing new techniques to predict myocardial infarction (MI). Coronary computed tomography (CT) angiography, also known as CCTA, along with 7-protein serum biomarker risk assessment was performed for risk evaluation. A 48-year-old SOCOM Soldier with a family history of heart disease had skeletal chest pain from war injuries and a 5-fold higher risk of heart attack over the next 5 years on the basis of protein markers. A nonobstructive left anterior descending coronary artery (LAD) plaque with a lipid-rich core and a thin fibrous cap (i.e., vulnerable plaque) was detected by CCTA. The patient was warned about his risk and prescribed four cardiac medications and scheduled for angioplasty even though he fell outside the guidelines by not having a severe obstructive blockage. Four days later, unfortunately, he had a heart attack before starting his medications and before angioplasty. CCTA with biomarker testing may have an important role in predicating acute coronary syndrome (ACS) in Special Operations Forces (SOF) Soldiers with at least one risk factor. Conventional stress testing and nuclear scanning would not detect non-flow-limiting vulnerable plaques in vulnerable patients. In order to collect more data, the PROTECT Registry has been started to evaluate asymptomatic Soldiers with at least one risk factor referred to the clinic by military physicians. 2015.

Carotid Plaque Lipid Content and Fibrous Cap Status Predict Systemic CV Outcomes: The MRI Substudy in AIM-HIGH.

PubMed

Sun, Jie; Zhao, Xue-Qiao; Balu, Niranjan; Neradilek, Moni B; Isquith, Daniel A; Yamada, Kiyofumi; Cantón, Gádor; Crouse, John R; Anderson, Todd J; Huston, John; O'Brien, Kevin; Hippe, Daniel S; Polissar, Nayak L; Yuan, Chun; Hatsukami, Thomas S

2017-03-01

clinical risk factors, plaque burden, or AIM-HIGH randomized treatment assignment. Among patients with clinically established atherosclerotic disease, carotid plaque lipid content and fibrous cap status were strongly associated with systemic cardiovascular outcomes. Markers of carotid plaque vulnerability may serve as novel surrogate markers for systemic atherothrombotic risk. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Use of high-resolution 3.0-T magnetic resonance imaging to characterize atherosclerotic plaques in patients with cerebral infarction

PubMed Central

XU, PENG; LV, LULU; LI, SHAODONG; GE, HAITAO; RONG, YUTAO; HU, CHUNFENG; XU, KAI

2015-01-01

The present study aimed to evaluate the utility of high-resolution magnetic resonance imaging (MRI) in the characterization of atherosclerotic plaques in patients with acute and non-acute cerebral infarction. High-resolution MRI of unilateral stenotic middle cerebral arteries was performed to evaluate the degree of stenosis, the wall and plaque areas, plaque enhancement patterns and lumen remodeling features in 15 and 17 patients with acute and non-acute cerebral infarction, respectively. No significant difference was identified in the vascular stenosis rate between acute and non-acute patients. Overall, plaque eccentricity was observed in 29 patients, including 13 acute and 16 non-acute cases, with no significant difference identified between these groups. The wall area of stenotic arteries and the number of cases with plaque enhancement were significantly greater in the acute patients, but no significant difference in plaque or lumen area was identified between the 2 patient groups. Lumen remodeling patterns of stenotic arteries significantly differed between the acute and non-acute patients; the former predominantly demonstrated positive remodeling, and the latter group demonstrated evidence of negative remodeling. In conclusion, patients with acute and non-acute cerebral infarction exhibit specific characteristics in stenotic arteries and plaques, which can be effectively evaluated by high-resolution MRI. PMID:26668651

Impaired JIP3-dependent axonal lysosome transport promotes amyloid plaque pathology

PubMed Central

Gowrishankar, Swetha; Wu, Yumei

2017-01-01

Lysosomes robustly accumulate within axonal swellings at Alzheimer’s disease (AD) amyloid plaques. However, the underlying mechanisms and disease relevance of such lysosome accumulations are not well understood. Motivated by these problems, we identified JNK-interacting protein 3 (JIP3) as an important regulator of axonal lysosome transport and maturation. JIP3 knockout mouse neuron primary cultures accumulate lysosomes within focal axonal swellings that resemble the dystrophic axons at amyloid plaques. These swellings contain high levels of amyloid precursor protein processing enzymes (BACE1 and presenilin 2) and are accompanied by elevated Aβ peptide levels. The in vivo importance of the JIP3-dependent regulation of axonal lysosomes was revealed by the worsening of the amyloid plaque pathology arising from JIP3 haploinsufficiency in a mouse model of AD. These results establish the critical role of JIP3-dependent axonal lysosome transport in regulating amyloidogenic amyloid precursor protein processing and support a model wherein Aβ production is amplified by plaque-induced axonal lysosome transport defects. PMID:28784610

Fluoride bioavailability in saliva and plaque

PubMed Central

2012-01-01

Background Different fluoride formulations may have different effects on caries prevention. It was the aim of this clinical study to assess the fluoride content, provided by NaF compared to amine fluoride, in saliva and plaque. Methods Eight trained volunteers brushed their teeth in the morning for 3 minutes with either NaF or amine fluoride, and saliva and 3-day-plaque-regrowth was collected at 5 time intervals during 6 hours after tooth brushing. The amount of collected saliva and plaque was measured, and the fluoride content was analysed using a fluoride sensitive electrode. All subjects repeated all study cycles 5 times, and 3 cycles per subject underwent statistical analysis using the Wilcoxon-Mann-Whitney test. Results Immediately after brushing the fluoride concentration in saliva increased rapidly and dropped to the baseline level after 360 minutes. No difference was found between NaF and amine fluoride. All plaque fluoride levels were elevated after 30 minutes until 120 minutes after tooth brushing, and decreasing after 360 minutes to baseline. According to the highly individual profile of fluoride in saliva and plaque, both levels of bioavailability correlated for the first 30 minutes, and the fluoride content of saliva and plaque was back to baseline after 6 hours. Conclusions Fluoride levels in saliva and plaque are interindividually highly variable. However, no significant difference in bioavailability between NaF and amine fluoride, in saliva, or in plaque was found. PMID:22230722

Isolating social influences on vulnerability to earthquake shaking: identifying cost-effective mitigation strategies.

NASA Astrophysics Data System (ADS)

Bhloscaidh, Mairead Nic; McCloskey, John; Pelling, Mark; Naylor, Mark

2013-04-01

Until expensive engineering solutions become more universally available, the objective targeting of resources at demonstrably effective, low-cost interventions might help reverse the trend of increasing mortality in earthquakes. Death tolls in earthquakes are the result of complex interactions between physical effects, such as the exposure of the population to strong shaking, and the resilience of the exposed population along with supporting critical infrastructures and institutions. The identification of socio-economic factors that contribute to earthquake mortality is crucial to identifying and developing successful risk management strategies. Here we develop a quantitative methodology more objectively to assess the ability of communities to withstand earthquake shaking, focusing on, in particular, those cases where risk management performance appears to exceed or fall below expectations based on economic status. Using only published estimates of the shaking intensity and population exposure for each earthquake, data that is available for earthquakes in countries irrespective of their level of economic development, we develop a model for mortality based on the contribution of population exposure to shaking only. This represents an attempt to remove, as far as possible, the physical causes of mortality from our analysis (where we consider earthquake engineering to reduce building collapse among the socio-economic influences). The systematic part of the variance with respect to this model can therefore be expected to be dominated by socio-economic factors. We find, as expected, that this purely physical analysis partitions countries in terms of basic socio-economic measures, for example GDP, focusing analytical attention on the power of economic measures to explain variance in observed distributions of earthquake risk. The model allows the definition of a vulnerability index which, although broadly it demonstrates the expected income-dependence of vulnerability to

Intraplaque hemorrhage, fibrous cap status, and microembolic signals in symptomatic patients with mild to moderate carotid artery stenosis: the Plaque at RISK study.

PubMed

Truijman, Martine T B; de Rotte, Alexandra A J; Aaslid, Rune; van Dijk, Anouk C; Steinbuch, Jeire; Liem, Madieke I; Schreuder, Floris H B M; van der Steen, Anton F W; Daemen, Mat J A P; van Oostenbrugge, Robert J; Wildberger, Joachim E; Nederkoorn, Paul J; Hendrikse, Jeroen; van der Lugt, Aad; Kooi, Marianne Eline; Mess, Werner H

2014-11-01

In patients with mild to moderate symptomatic carotid artery stenosis, intraplaque hemorrhage (IPH) and a thin/ruptured fibrous cap (FC) as evaluated with MRI, and the presence of microembolic signals (MESs) as detected with transcranial Doppler, are associated with an increased risk of a (recurrent) stroke. The objective of the present study is to determine whether the prevalence of MES differs in patients with and without IPH and thin/ruptured FC, and patients with only a thin/ruptured FC without IPH. In this multicenter, diagnostic cohort study, patients with recent transient ischemic attack or minor stroke in the carotid territory and an ipsilateral mild to moderate carotid artery plaque were included. IPH and FC status were dichotomously scored. Analysis of transcranial Doppler data was done blinded for the MRI results. Differences between groups were analyzed with Fisher exact test. A total of 113 patients were included. Transcranial Doppler measurements were feasible in 105 patients (average recording time, 219 minutes). A total of 26 MESs were detected in 8 of 105 patients. In 44 of 105 plaques IPH was present. In 92 of 105 plaques FC status was assessable, 36 of these had a thin/ruptured FC. No significant difference in the prevalence of MES between patients with and without IPH (P=0.46) or with thick versus thin/ruptured FC (P=0.48) was found. In patients with a symptomatic mild to moderate carotid artery stenosis, IPH and FC status are not associated with MES. This suggests that MRI and transcranial Doppler provide different information on plaque vulnerability. http://www.clinicaltrials.gov. Unique identifier: NCT01709045. © 2014 American Heart Association, Inc.

Intra-individual comparison of carotid and femoral atherosclerotic plaque features with in vivo MR plaque imaging.

PubMed

Helck, Andreas; Bianda, Nicola; Canton, Gador; Yuan, Chun; Hippe, Daniel S; Reiser, Maximilian F; Gallino, Augusto; Wyttenbach, Rolf; Saam, Tobias

2015-12-01

The purpose of this study was to evaluate differences of plaque composition and morphology within the same patient in different vascular beds using non-invasive MR-plaque imaging. 28 patients (67.8 ± 7.4 years, 8 females) with high Framingham general cardiovascular disease 10-year risk score and mild-to-moderate atherosclerosis were consecutively included in the study. All subjects underwent a dedicated MRI-plaque imaging protocol using TOF and T1w and T2w black-blood-sequences with fat suppression at 1.5 T. The scan was centered on the carotid bulb of the carotid arteries and on the most stenotic lesion of the ipsilateral femoral artery, respectively. Plaques were classified according to the American Heart Association (AHA) lesion type classification and area measurements of lumen, wall and the major plaque components, such as calcification, necrotic core and hemorrhage were determined in consensus by two blinded reviewers using dedicated software (Cascade, Seattle, USA). Plaque components were recorded as maximum percentages of the wall area. Carotid arteries had larger maximum wall and smaller minimum lumen areas (p < 0.001) than femoral arteries, whereas no significant difference was find with respect to the max. NWI (p = 0.87). Prevalence of lipid-rich AHA lesion type IV/V and complicated AHA lesion type VI with hemorrhage/thrombus/fibrous cap rupture was significantly higher in the carotid arteries compared to the femoral arteries. Plaque composition as percentage of the vessel wall differed significantly between carotid and femoral arteries: Max. %necrotic core and max. %hemorrhage were significantly higher in the carotid arteries compared to the femoral arteries (p = 0.001 and p = 0.02, respectively). Max. %calcification did not differ significantly. Average stenotic degree of carotid arteries at duplex was 49.7 ± 12.5 (%). Non-invasive MR plaque-imaging is able to visualize differences in plaque composition across the vascular tree. We observed

Identifying key features of early stressful experiences that produce stress vulnerability and resilience in primates

PubMed Central

Parker, Karen J.; Maestripieri, Dario

2010-01-01

This article examines the complex role of early stressful experiences in producing both vulnerability and resilience to later stress-related psychopathology in a variety of primate models of human development. Two types of models are reviewed: Parental Separation Models (e.g., isolate-rearing, peer-rearing, parental separations, and stress inoculation) and Maternal Behavior Models (e.g., foraging demands, variation in maternal style, and maternal abuse). Based on empirical evidence, it is argued that early life stress exposure does not increase adult vulnerability to stress-related psychopathology as a linear function, as is generally believed, but instead reflects a quadratic function. Features of early stress exposure including the type, duration, frequency, ecological validity, sensory modality, and developmental timing, within and between species, are identified to better understand how early stressful experiences alter neurobiological systems to produce such diverse developmental outcomes. This article concludes by identifying gaps in our current knowledge, providing directions for future research, and discussing the translational implications of these primate models for human development and psychopathology. PMID:20851145

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

PubMed

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.

Material properties of components in human carotid atherosclerotic plaques: a uniaxial extension study.

PubMed

Teng, Zhongzhao; Zhang, Yongxue; Huang, Yuan; Feng, Jiaxuan; Yuan, Jianmin; Lu, Qingsheng; Sutcliffe, Michael P F; Brown, Adam J; Jing, Zaiping; Gillard, Jonathan H

2014-12-01

Computational modelling to calculate the mechanical loading within atherosclerotic plaques has been shown to be complementary to defining anatomical plaque features in determining plaque vulnerability. However, its application has been partially impeded by the lack of comprehensive knowledge about the mechanical properties of various tissues within the plaque. Twenty-one human carotid plaques were collected from endarterectomy. The plaque was cut into rings, and different type of atherosclerotic tissues, including media, fibrous cap (FC), lipid and intraplaque haemorrhage/thrombus (IPH/T) was dissected for uniaxial extension testing. In total, 65 media strips from 17 samples, 59 FC strips from 14 samples, 38 lipid strips from 11 samples, and 21 IPH/T strips from 11 samples were tested successfully. A modified Mooney-Rivlin strain energy density function was used to characterize the stretch-stress relationship. The stiffnesses of media and FC are comparable, as are lipid and IPH/T. However, both media and FC are stiffer than either lipid or IPH/T. The median values of incremental Young's modulus of media, FC, lipid and IPH/T at λ=1 are 290.1, 244.5, 104.4, 52.9, respectively; they increase to 1019.5, 817.4, 220.7 and 176.9 at λ=1.1; and 4302.7, 3335.0, 533.4 and 268.8 at λ=1.15 (unit, kPa; λ, stretch ratio). The material constants of each tissue type are suggested to be: media, c1=0.138kPa, D1=3.833kPa and D2=18.803; FC, c1=0.186kPa, D1=5.769kPa and D2=18.219; lipid, c1=0.046kPa, D1=4.885kPa and D2=5.426; and IPH/T, c1=0.212kPa, D1=4.260kPa and D2=5.312. It is concluded that all soft atherosclerotic tissues are non-linear, and both media and FC are stiffer than either lipid or IPH/T. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Dental plaque identification at home

MedlinePlus

... 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 ...

INCIDENCE OF HELICOBACTER PYLORI IN DENTAL PLAQUE OF SAUDI GASTRITIS PATIENTS

PubMed Central

Al-Refai, Abdel-Nasser M.; Fathalla, Sami E.; Nagamani, Rambhala; Al-Momen, Sami

2002-01-01

Background: Helicobacter pylori (H. pylori) was identified in dental plaque, raising the possibility of future gastritis and peptic ulceration. Objective: This trial was to study the association between presence of H. pylori in dental plaque and in the stomachs of patients with gastritis; the effect of oral hygiene and periodontal condition on the stomach. Patients and Methods: Seventy-five Saudi adult dyspeptic patients, together with 60 healthy persons as control. Two samples of dental plaque were taken from gingival crevice of deepest pocket. One sample was kept in Christensen's urea agar and incubated for H. pylori detection by rapid urease test. The second sample was kept in 5% sheep blood agar, chocolate agar and a selective medium to culture the H. pylori. Gastric urease test was done for the same patients. Results: (1) Plaque urease test results showed 89% positive patients. (2) Dental plaque Index:- Mild dental plaque accumulation in 24%, moderate in 41%, while severe accumulation was in 35% of the patients. (3) Gingival Index: Showed mild, moderate and severe gingivitis in 17%, 48% and 35% of patients, respectively. (4) Community periodontal index of treatment needs (CPITN): Showed gingivitis, mild periodontitis and moderate periodontitis in 50%, 23% and 27% of patients, respectively. (5)Gastric urease results: 87% of patients were positive. (6)All cultured samples results were negative Conclusion: The ability to detect H. pylori in dental plaque samples offers a potential for a noninvasive test for gastric infection and would lend support for oral spread of H. pylori as the princi-pal mode of transmission. However, the presence of H. pylori in dental plaque and in the stomach (in gastritis patients) could permit not only a target for therapeutic procedures but also a monitor-ing tool for the efficacy of therapy. PMID:23008669

Identifying Population Vulnerable to Extreme Heat Events in San Jose, California.

NASA Astrophysics Data System (ADS)

Rivera, A. L.

2016-12-01

The extreme heat days not only make cities less comfortable for living but also they are associated with increased morbidity and mortality. Mapping studies have demonstrated spatial variability in heat vulnerability. A study conducted between 2000 and 2011 in New York City shows that deaths during heat waves was more likely to occur in black individuals, at home in census tracts which received greater public assistance. This map project intends to portray areas in San Jose California that are vulnerable to extreme heat events. The variables considered to build a vulnerability index are: land surface temperature, vegetated areas (NDVI), and people exposed to these area (population density).

Identification of Mature Atherosclerotic Plaque Proteome Signatures Using Data-Independent Acquisition Mass Spectrometry.

PubMed

Hansmeier, Nicole; Buttigieg, Josef; Kumar, Pankaj; Pelle, Shaneen; Choi, Kyoo Yoon; Kopriva, David; Chao, Tzu-Chiao

2018-01-05

Atherosclerosis is a chronic inflammatory disease with complex pathobiology and one of the most common causes of cardiovascular events. The process is characterized by complex vascular remodeling processes that require the actions of numerous proteins. The composition of atherosclerotic plaque is increasingly recognized as a major factor governing the occurrence of cardiovascular or neurological symptoms. To gain deeper insights into the composition of atherosclerotic plaques, we created quantitative proteome profiles of advanced plaque tissues of six male patients undergoing carotid endarterectomy for stroke prevention. Using a quantitative, data-independent proteome approach, we identified 4181 proteins with an average protein coverage of 45%. An analysis of the quantitative composition of the tissue revealed key players of vascular remodeling processes. Moreover, compared with proximal arterial tissue, 20 proteins in mature plaques were enriched, whereas 52 proteins were found in lower quantities. Among the proteins with increased abundance were prominent extracellular matrix proteins such as biglycan and lumican, whereas cytoskeletal markers for contractile smooth muscle cells (SMCs) were decreased. Taken together, this study provides the most comprehensive quantitative assessment of mature human plaque tissue to date, which indicates a central role of SMCs in the structure of advanced atherosclerotic plaques.

Myeloperoxidase-oxidized high density lipoprotein impairs atherosclerotic plaque stability by inhibiting smooth muscle cell migration.

PubMed

Zhou, Boda; Zu, Lingyun; Chen, Yong; Zheng, Xilong; Wang, Yuhui; Pan, Bing; Dong, Min; Zhou, Enchen; Zhao, Mingming; Zhang, Youyi; Zheng, Lemin; Gao, Wei

2017-01-10

High density lipoprotein (HDL) has been proved to be a protective factor for coronary heart disease. Notably, HDL in atherosclerotic plaques can be nitrated (NO 2 -oxHDL) and chlorinated (Cl-oxHDL) by myeloperoxidase (MPO), likely compromising its cardiovascular protective effects. Here we determined the effects of NO 2 -oxHDL and Cl-oxHDL on SMC migration using wound healing and transwell assays, proliferation using MTT and BrdU assays, and apoptosis using Annexin-V assay in vitro, as well as on atherosclerotic plaque stability in vivo using a coratid artery collar implantation mice model. Our results showed that native HDL promoted SMC proliferation and migration, whereas NO 2 -oxHDL and Cl-oxHDL inhibited SMC migration and reduced capacity of stimulating SMC proliferation as well as migration, respectively. OxHDL had no significant influence on SMC apoptosis. In addition, we found that ERK1/2-phosphorylation was significantly lower when SMCs were incubated with NO 2 -oxHDL and Cl-oxHDL. Furthermore, transwell experiments showed that differences between native HDL, NO 2 -oxHDL and Cl-oxHDL was abolished after PD98059 (MAPK kinase inhibitor) treatment. In aortic SMCs from scavenger receptor BI (SR-BI) deficient mice, differences between migration of native HDL, NO 2 -oxHDL and Cl-oxHDL treated SMCs vanished, indicating SR-BI's possible role in HDL-associated SMC migration. Importantly, NO 2 -oxHDL and Cl-oxHDL induced neointima formation and reduced SMC positive staining cells in atherosclerotic plaque, resulting in elevated vulnerable index of atherosclerotic plaque. These findings implicate MPO-catalyzed oxidization of HDL may contribute to atherosclerotic plaque instability by inhibiting SMC proliferation and migration through MAPK-ERK pathway which was dependent on SR-BI.

Photogrammetric registration of dental plaque accumulation in vivo.

PubMed

Bergström, J

1981-01-01

Using the labial surface of upper anterior laterals for determination, the accumulation of plaque was assessed by means of a stereo-photogrammetric method. The stereoimages were subjected to photogrammetric evaluation, the part of the surface area covered by plaque being given in per cent of the total surface area of the tooth. Plaque extension and plaque topography was studied in young adults with healthy periodontia during a 20 day period of no oral hygiene. At the end of the experimental period, on an average 75 per cent of the surface area was covered by plaque, corresponding to an extension rate of 3.75 per cent per day. The correlation between plaque values obtained by photogrammetry and various estimates obtained from clinical scoring ranged between r = 0.66 and r = 0.78. It is concluded that the method introduced is a sensitive means of determining small amounts of plaque and should prove useful for in vivo investigation of plaque growth and plaque suppression, where measurements of high quality is of importance.

Interaction of Neuritic Plaques and Education Predicts Dementia

PubMed Central

Roe, Catherine M.; Xiong, Chengjie; Miller, J. Phillip; Cairns, Nigel J.; Morris, John C.

2009-01-01

In exploring the cognitive reserve hypothesis in persons with substantial Alzheimer disease neuropathology, we aimed to determine the extent to which educational attainment and densities of diffuse plaques, neuritic plaques, and neurofibrillary tangles predict dementia. Participants were 1563 individuals aged 65 years or above who were assessed for dementia within 1 year of death. Generalized linear mixed models were used to examine whether education and density ratings of diffuse plaques and neuritic plaques, and neurofibrillary tangle stage were associated with a dementia diagnosis. Education interacted with densities of neuritic plaques to predict dementia. Tangle density independently predicted dementia, but did not interact with education. Diffuse plaque density was unrelated to dementia when adjusted for densities of neuritic plaques and tangles. Among individuals with Alzheimer disease neuropathology, educational attainment, as a surrogate of cognitive reserve, modifies the influence of neuritic, but not diffuse, plaque neuropathology on the expression of dementia. PMID:18525294

Integrating social media and remote sensing data in a model framework to identify vulnerable areas in coastal cities after disasters

NASA Astrophysics Data System (ADS)

Gopalakrishnan, G.

2013-12-01

In the aftermath of man-made disasters such as oil spills or natural disasters such as hurricanes and floods, city planners and residents of affected areas are often concerned about future vulnerabilities and rebuilding the area to increase resilience. However, identifying locations in the affected area that are most impacted by the disaster, the associated human health risks and potential vulnerabilities often require a monitoring effort that is expensive, time-consuming and difficult to implement in disaster-hit areas using traditional monitoring techniques. This project presents a framework for identifying areas that are most likely to be impacted by disasters by integrating remote sensing data and information from social media networks, including Twitter streams. The framework was tested for New York, coastal New Jersey and Staten Island in the aftermath of Hurricane Sandy. Vulnerable areas were identified using anomaly detection and the results were mapped against measurements collected on the ground. A correlation coefficient of 0.78 was obtained. Uncertainty in model predictions was evaluated using Monte Carlo simulations.

Making a Lightweight Battery Plaque

NASA Technical Reports Server (NTRS)

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

1986-01-01

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

ASTRONAUT STAFFORD, THOMAS P. - PLAQUES - JSC

NASA Image and Video Library

1975-02-01

S75-25823 (February 1975) --- Cosmonaut Aleksei A. Leonov (left) and astronaut Thomas P. Stafford display the Apollo Soyuz Test Project (ASTP) commemorative plaque. The two commanders, of their respective crews, are in the Apollo Command Module (CM) trainer at Building 35 at NASA's Johnson Space Center (JSC). Two plaques divided into four quarters each will be flown on the ASTP mission. The American ASTP Apollo crew will carry the four United States quarter pieces aboard Apollo; and the Soviet ASTP Soyuz 19 crew will carry the four USSR quarter sections aboard Soyuz. The eight quarter pieces will be joined together to form two complete commemorative plaques after the two spacecraft rendezvous and dock in Earth orbit. One complete plaque then will be returned to Earth by the astronauts; and the other complete plaque will be brought back by the cosmonauts. The plaque is written in both English and Russian. The Apollo crew will consist of astronauts Thomas P. Stafford, commander; Donald K. "Deke" Slayton, docking module pilot; Vance D. Brand, command module pilot. The Soyuz 19 crew will consist of cosmonauts Aleksei A. Leonov, command pilot; and Valeri N. Kubasov, flight engineer.

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.

PubMed

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), <50% calcified area as mixed (MCAP), and plaques without any calcium as non-calcified (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

Effects of atorvastatin on serum lipids, serum inflammation and plaque morphology in patients with stable atherosclerotic plaques.

PubMed

Guo, Suxia; Wang, Ruxing; Yang, Zhenyu; Li, Kulin; Wang, Qiang

2012-12-01

Statin treatment in patients with coronary heart disease is associated with a reduced incidence of short-term adverse events and endpoint cardiac events. However, the effects of statin treatment on atherosclerotic plaques, particularly stable plaques, remain poorly defined. In total, 228 consecutive patients with stable atherosclerotic plaques who had undergone coronary arteriography (CAG) and intravascular ultrasound (IVUS) were randomly assigned to receive placebo (placebo group, n=54) or atorvastatin (ATOR) at a single daily dose of 10 mg (ATOR 10 mg group, n=47), 20 mg (ATOR 20 mg group, n=45), 40 mg (ATOR 40 mg group, n=43) or 80 mg (ATOR 80 mg group, n=39). Endpoints, including serum lipids, serum inflammation, plaque volume and percentage of plaque necrosis were assessed after 3-6 months. At baseline, mean low-density lipoprotein (LDL), high-density lipoprotein (HDL) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as plaque volumes and percentages of plaque necrosis, were similar between all groups. At 6 months of follow-up, the LDL levels in the ATOR groups were below those at their respective baselines (P<0.01). HDL levels in the ATOR 80 mg group following treatment were significantly higher compared with baseline (P=0.001). Additionally, they were significantly higher compared with those in the placebo, ATOR 10, 20 and 40 mg groups (P<0.01, P=0.001, P=0.048, P=0.047, respectively). Hs-CRP levels in the placebo group following treatment were higher compared with baseline levels (6.87±2.62 vs. 5.07±1.80, P<0.01), but hs-CRP levels in the ATOR 80 mg group following treatment were lower compared with baseline (3.59±1.07 vs. 6.10±2.12, P<0.01). According to the virtual histology (VH) of IVUS, the percentages of plaque necrosis following treatment in the placebo and ATOR 10 mg groups rose above baseline levels (15.51±12.56 vs. 7.69±1.31%, 13.54±11.76 vs. 7.83±1.43%, P<0.01) and conformed to the diagnostic criteria for unstable plaques

Effects of atorvastatin on serum lipids, serum inflammation and plaque morphology in patients with stable atherosclerotic plaques

PubMed Central

GUO, SUXIA; WANG, RUXING; YANG, ZHENYU; LI, KULIN; WANG, QIANG

2012-01-01

Statin treatment in patients with coronary heart disease is associated with a reduced incidence of short-term adverse events and endpoint cardiac events. However, the effects of statin treatment on atherosclerotic plaques, particularly stable plaques, remain poorly defined. In total, 228 consecutive patients with stable atherosclerotic plaques who had undergone coronary arteriography (CAG) and intravascular ultrasound (IVUS) were randomly assigned to receive placebo (placebo group, n=54) or atorvastatin (ATOR) at a single daily dose of 10 mg (ATOR 10 mg group, n=47), 20 mg (ATOR 20 mg group, n=45), 40 mg (ATOR 40 mg group, n=43) or 80 mg (ATOR 80 mg group, n=39). Endpoints, including serum lipids, serum inflammation, plaque volume and percentage of plaque necrosis were assessed after 3–6 months. At baseline, mean low-density lipoprotein (LDL), high-density lipoprotein (HDL) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as plaque volumes and percentages of plaque necrosis, were similar between all groups. At 6 months of follow-up, the LDL levels in the ATOR groups were below those at their respective baselines (P<0.01). HDL levels in the ATOR 80 mg group following treatment were significantly higher compared with baseline (P=0.001). Additionally, they were significantly higher compared with those in the placebo, ATOR 10, 20 and 40 mg groups (P<0.01, P=0.001, P=0.048, P=0.047, respectively). Hs-CRP levels in the placebo group following treatment were higher compared with baseline levels (6.87±2.62 vs. 5.07±1.80, P<0.01), but hs-CRP levels in the ATOR 80 mg group following treatment were lower compared with baseline (3.59±1.07 vs. 6.10±2.12, P<0.01). According to the virtual histology (VH) of IVUS, the percentages of plaque necrosis following treatment in the placebo and ATOR 10 mg groups rose above baseline levels (15.51±12.56 vs. 7.69±1.31%, 13.54±11.76 vs. 7.83±1.43%, P<0.01) and conformed to the diagnostic criteria for unstable plaques

Carotid Artery Plaque Morphology and Composition in Relation to Incident Cardiovascular Events: The Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Zavodni, Anna E. H.; Wasserman, Bruce A.; McClelland, Robyn L.; Gomes, Antoinette S.; Folsom, Aaron R.; Polak, Joseph F.; Lima, João A. C.

2014-01-01

Purpose To determine if carotid plaque morphology and composition with magnetic resonance (MR) imaging can be used to identify asymptomatic subjects at risk for cardiovascular events. Materials and Methods Institutional review boards at each site approved the study, and all sites were Health Insurance Portability and Accountability Act (HIPAA) compliant. A total of 946 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) were evaluated with MR imaging and ultrasonography (US). MR imaging was used to define carotid plaque composition and remodeling index (wall area divided by the sum of wall area and lumen area), while US was used to assess carotid wall thickness. Incident cardiovascular events, including myocardial infarction, resuscitated cardiac arrest, angina, stroke, and death, were ascertained for an average of 5.5 years. Multivariable Cox proportional hazards models, C statistics, and net reclassification improvement (NRI) for event prediction were determined. Results Cardiovascular events occurred in 59 (6%) of participants. Carotid IMT as well as MR imaging remodeling index, lipid core, and calcium in the internal carotid artery were significant predictors of events in univariate analysis (P < .001 for all). For traditional risk factors, the C statistic for event prediction was 0.696. For MR imaging remodeling index and lipid core, the C statistic was 0.734 and the NRI was 7.4% and 15.8% for participants with and those without cardiovascular events, respectively (P = .02). The NRI for US IMT in addition to traditional risk factors was not significant. Conclusion The identification of vulnerable plaque characteristics with MR imaging aids in cardiovascular disease prediction and improves the reclassification of baseline cardiovascular risk. © RSNA, 2014 PMID:24592924

Ghrelin inhibits atherosclerotic plaque angiogenesis and promotes plaque stability in a rabbit atherosclerotic model.

PubMed

Wang, Li; Chen, Qingwei; Ke, Dazhi; Li, Guiqiong

2017-04-01

Intraplaque angiogenesis associates with the instability of atherosclerotic plaques. In the present study, we investigated the effects of ghrelin on intraplaque angiogenesis and plaque instability in a rabbit model of atherosclerosis. The rabbits were randomly divided into three groups, namely, the control group, atherosclerotic model group, and ghrelin-treated group, with treatments lasting for 4 weeks. We found that the thickness ratio of the intima to media in rabbits of the ghrelin-treated group was significantly lower than that in rabbits of the atherosclerotic model group. The number of neovessels and the levels of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) decreased dramatically in rabbits of the ghrelin-treated group compared to those of the atherosclerotic model group. Ghrelin significantly decreased the plaque content of macrophages, matrix metalloproteinase (MMP)-2, and MMP-9, in a rabbit model of atherosclerosis. In addition, the level of the pro-inflammatory factor monocyte chemoattractant protein (MCP)-1 was significantly lower in rabbits of the ghrelin-treated group than in rabbits of the atherosclerotic model group. In summary, ghrelin can inhibit intraplaque angiogenesis and promote plaque stability by down-regulating VEGF and VEGFR2 expression, inhibiting the plaque content of macrophages, and reducing MCP-1 expression at an advanced stage of atherosclerosis in rabbits. Copyright © 2017 Elsevier Inc. All rights reserved.

Low copper and high manganese levels in prion protein plaques

USGS Publications Warehouse

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.

Effect of Intensive Statin Therapy on Coronary High-Intensity Plaques Detected by Noncontrast T1-Weighted Imaging: The AQUAMARINE Pilot Study.

PubMed

Noguchi, Teruo; Tanaka, Atsushi; Kawasaki, Tomohiro; Goto, Yoichi; Morita, Yoshiaki; Asaumi, Yasuhide; Nakao, Kazuhiro; Fujiwara, Reiko; Nishimura, Kunihiro; Miyamoto, Yoshihiro; Ishihara, Masaharu; Ogawa, Hisao; Koga, Nobuhiko; Narula, Jagat; Yasuda, Satoshi

2015-07-21

Coronary high-intensity plaques detected by noncontrast T1-weighted imaging may represent plaque instability. High-intensity plaques can be quantitatively assessed by a plaque-to-myocardium signal-intensity ratio (PMR). This pilot, hypothesis-generating study sought to investigate whether intensive statin therapy would lower PMR. Prospective serial noncontrast T1-weighted magnetic resonance imaging and computed tomography angiography were performed in 48 patients with coronary artery disease at baseline and after 12 months of intensive pitavastatin treatment with a target low-density lipoprotein cholesterol level <80 mg/dl. The control group consisted of coronary artery disease patients not treated with statins that were matched by propensity scoring (n = 48). The primary endpoint was the 12-month change in PMR. Changes in computed tomography angiography parameters and high-sensitivity C-reactive protein levels were analyzed. In the statin group, 12 months of statin therapy significantly improved low-density lipoprotein cholesterol levels (125 to 70 mg/dl; p < 0.001), PMR (1.38 to 1.11, an 18.9% reduction; p < 0.001), low-attenuation plaque volume, and the percentage of total atheroma volume on computed tomography. In the control group, the PMR increased significantly (from 1.22 to 1.49, a 19.2% increase; p < 0.001). Changes in PMR were correlated with changes in low-density lipoprotein cholesterol (r = 0.533; p < 0.001), high-sensitivity C-reactive protein (r = 0.347; p < 0.001), percentage of atheroma volume (r = 0.477; p < 0.001), and percentage of low-attenuation plaque volume (r = 0.416; p < 0.001). Statin treatment significantly reduced the PMR of high-intensity plaques. Noncontrast T1-weighted magnetic resonance imaging could become a useful technique for repeated quantitative assessment of plaque composition. (Attempts at Plaque Vulnerability Quantification with Magnetic Resonance Imaging Using Noncontrast T1-weighted Technique [AQUAMARINE

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

PubMed Central

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

[Aging and becoming vulnerable].

PubMed

Monod, Stéfanie; Sautebin, Annelore

2009-11-18

"The vulnerable are those whose autonomy, dignity and integrity are capable of being threatened". Based on this ethical definition of vulnerability, four risk factors of vulnerability might be identified among elderly persons, and are described in this article: the functional limitation, the loss of autonomy, the social precariousness and the restriction of access to medical care. A clinical case of elderly abuse is presented to illustrate vulnerability. Finally, some recommendations to lower the risk of vulnerability in elderly persons are proposed.

Overexpression of hypoxia/inflammatory markers in atherosclerotic carotid plaques.

PubMed

Luque, Ana; Turu, Marta; Juan-Babot, Oriol; Cardona, Pere; Font, Angels; Carvajal, Ana; Slevin, Mark; Iborra, Elena; Rubio, Francisco; Badimon, Lina; Krupinski, Jerzy

2008-05-01

Hypoxia, angiogenesis and inflammation leads to plaque progression and remodelling and may significantly contribute towards plaque rupture and subsequent cerebrovascular events. Our aim was to study, markers of hypoxia and inflammation previously identified by microarray analysis, in atherosclerotic carotid arteries with low to moderate stenosis. We hoped to describe different cellular populations expressing the studied markers. The location of selected inflammatory molecules obtained as vascular transplants from organ donors were analysed by immunohistochemistry with monoclonal and polyclonal antibodies. Paraffin-embedded sections were cut and probed with antibodies recognizing active B and T-lymphocytes (CD30), hypoxia-inducible factor-1alpha, endoglin (CD105), Interleukin-6 and C-reactive protein. We observed a notable overexpression of HIF-1alpha in inflammatory and hypoxic areas of carotid arteries in all types of lesions from type II-V taken from the patients with carotid stenosis less than 50%. This suggests that HIF-1alpha may have a putative role in atherosclerosis progression and angiogenesis. Dynamic changes in the non-occluding plaques may explain some of the clinical events in patients with low to moderate carotid stenosis.

Icaritin Inhibits Collagen Degradation-Related Factors and Facilitates Collagen Accumulation in Atherosclerotic Lesions: A Potential Action for Plaque Stabilization

PubMed Central

Zhang, Zong-Kang; Li, Jie; Yan, De-Xin; Leung, Wing-Nang; Zhang, Bao-Ting

2016-01-01

Most acute coronary syndromes result from rupture of vulnerable atherosclerotic plaques. The collagen content of plaques may critically affect plaque stability. This study tested whether Icaritin (ICT), an intestinal metabolite of Epimedium-derived flavonoids, could alter the collagen synthesis/degradation balance in atherosclerotic lesions. Rabbits were fed with an atherogenic diet for four months. Oral administration of ICT (10 mg·kg−1·day−1) was started after two months of an atherogenic diet and lasted for two months. The collagen degradation-related parameters, including macrophages accumulation, content and activity of interstitial collagenase-1 (MMP-1), and the collagen synthesis-related parameters, including amount and distribution of smooth muscle cells (SMC) and collagen mRNA/protein levels, were evaluated in the aorta. ICT reduced plasma lipid levels, inhibited macrophage accumulation, lowered MMP-1 mRNA and protein expression, and suppressed proteolytic activity of pro-MMP-1 and MMP-1 in the aorta. ICT changed the distribution of the SMCs towards the fibrous cap of lesions without increasing the amount of SMCs. Higher collagen protein content in lesions and aorta homogenates was observed with ICT treatment compared with the atherogenic diet only, without altered collagen mRNA level. These results suggest that ICT could inhibit the collagen degradation-related factors and facilitate collagen accumulation in atherosclerotic lesions, indicating a new potential of ICT in atherosclerotic plaques. PMID:26828485

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

PubMed

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

Bacteria present in carotid arterial plaques are found as biofilm deposits which may contribute to enhanced risk of plaque rupture.

PubMed

Lanter, Bernard B; Sauer, Karin; Davies, David G

2014-06-10

, and we demonstrate that one species we have identified in plaques can be stimulated in vitro to undergo a biofilm dispersion response when challenged with physiologically relevant levels of norepinephrine in the presence of transferrin. Biofilm dispersion is characterized by the release of bacterial enzymes into the surroundings of biofilm microcolonies, allowing bacteria to escape the biofilm matrix. We believe these enzymes may have the potential to damage surrounding tissues and facilitate plaque rupture if norepinephrine is able to stimulate biofilm dispersion in vivo. This research, therefore, suggests a potential mechanistic link between hormonal state and the potential for heart attack and stroke. Copyright © 2014 Lanter et al.

Dental plaque - associated infections and antibacterial oral hygiene products.

PubMed

Verran, J

1991-02-01

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

[Differences between plaque-like variants of dermatofibrosarcoma protuberans and plaque-like dermal fibromatosis (dermatomyofibroma)].

PubMed

Hügel, H; Kutzner, H; Rütten, A; Biess, B

1994-05-01

On the basis of two cases the differences between the plaque-like variant of dermatofibrosarcoma protuberans (PDFSP) and the plaque-like dermal fibromatosis (synonym: dermatomyofibroma; PDF) are presented. PDFSP and PDF are two clinically very similar dermal fibrous proliferations, but differentiation is important because of their different therapy and prognosis. Histologically and immunohistochemically PDFSP and PDF can be recognized as separate entities.

Vulnerability- and Diversity-Aware Anonymization of Personally Identifiable Information for Improving User Privacy and Utility of Publishing Data

PubMed Central

Majeed, Abdul; Ullah, Farman; Lee, Sungchang

2017-01-01

Personally identifiable information (PII) affects individual privacy because PII combinations may yield unique identifications in published data. User PII such as age, race, gender, and zip code contain private information that may assist an adversary in determining the user to whom such information relates. Each item of user PII reveals identity differently, and some types of PII are highly identity vulnerable. More vulnerable types of PII enable unique identification more easily, and their presence in published data increases privacy risks. Existing privacy models treat all types of PII equally from an identity revelation point of view, and they mainly focus on hiding user PII in a crowd of other users. Ignoring the identity vulnerability of each type of PII during anonymization is not an effective method of protecting user privacy in a fine-grained manner. This paper proposes a new anonymization scheme that considers the identity vulnerability of PII to effectively protect user privacy. Data generalization is performed adaptively based on the identity vulnerability of PII as well as diversity to anonymize data. This adaptive generalization effectively enables anonymous data, which protects user identity and private information disclosures while maximizing the utility of data for performing analyses and building classification models. Additionally, the proposed scheme has low computational overheads. The simulation results show the effectiveness of the scheme and verify the aforementioned claims. PMID:28481298

Vulnerability- and Diversity-Aware Anonymization of Personally Identifiable Information for Improving User Privacy and Utility of Publishing Data.

PubMed

Majeed, Abdul; Ullah, Farman; Lee, Sungchang

2017-05-08

Personally identifiable information (PII) affects individual privacy because PII combinations may yield unique identifications in published data. User PII such as age, race, gender, and zip code contain private information that may assist an adversary in determining the user to whom such information relates. Each item of user PII reveals identity differently, and some types of PII are highly identity vulnerable. More vulnerable types of PII enable unique identification more easily, and their presence in published data increases privacy risks. Existing privacy models treat all types of PII equally from an identity revelation point of view, and they mainly focus on hiding user PII in a crowd of other users. Ignoring the identity vulnerability of each type of PII during anonymization is not an effective method of protecting user privacy in a fine-grained manner. This paper proposes a new anonymization scheme that considers the identity vulnerability of PII to effectively protect user privacy. Data generalization is performed adaptively based on the identity vulnerability of PII as well as diversity to anonymize data. This adaptive generalization effectively enables anonymous data, which protects user identity and private information disclosures while maximizing the utility of data for performing analyses and building classification models. Additionally, the proposed scheme has low computational overheads. The simulation results show the effectiveness of the scheme and verify the aforementioned claims.

Ultrafast laser ablation for targeted atherosclerotic plaque removal

NASA Astrophysics Data System (ADS)

Lanvin, Thomas; Conkey, Donald B.; Descloux, Laurent; Frobert, Aurelien; Valentin, Jeremy; Goy, Jean-Jacques; Cook, Stéphane; Giraud, Marie-Noelle; Psaltis, Demetri

2015-07-01

Coronary artery disease, the main cause of heart disease, develops as immune cells and lipids accumulate into plaques within the coronary arterial wall. As a plaque grows, the tissue layer (fibrous cap) separating it from the blood flow becomes thinner and increasingly susceptible to rupturing and causing a potentially lethal thrombosis. The stabilization and/or treatment of atherosclerotic plaque is required to prevent rupturing and remains an unsolved medical problem. Here we show for the first time targeted, subsurface ablation of atherosclerotic plaque using ultrafast laser pulses. Excised atherosclerotic mouse aortas were ablated with ultrafast near-infrared (NIR) laser pulses. The physical damage was characterized with histological sections of the ablated atherosclerotic arteries from six different mice. The ultrafast ablation system was integrated with optical coherence tomography (OCT) imaging for plaque-specific targeting and monitoring of the resulting ablation volume. We find that ultrafast ablation of plaque just below the surface is possible without causing damage to the fibrous cap, which indicates the potential use of ultrafast ablation for subsurface atherosclerotic plaque removal. We further demonstrate ex vivo subsurface ablation of a plaque volume through a catheter device with the high-energy ultrafast pulse delivered via hollow-core photonic crystal fiber.

Fully integrated optical coherence tomography, ultrasound, and indocyanine green based fluorescence tri-modality system for intravascular imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Li, Yan; Jing, Joseph C.; Qu, Yueqiao; Miao, Yusi; Ma, Teng; Yu, Mingyue; Zhou, Qifa; Chen, Zhongping

2017-02-01

The rupture of atherosclerotic plaques is the leading cause of acute coronary events, so accurate assessment of plaque is critical. A large lipid pool, thin fibrous cap, and inflammatory reaction are the crucial characteristics for identifying vulnerable plaques. In our study, a tri-modality imaging system for intravascular imaging was designed and implemented. The tri-modality imaging system with a 1-mm probe diameter is able to simultaneously acquire optical coherence tomography (OCT), intravascular ultrasound (IVUS), and fluorescence imaging. Moreover, for fluorescence imaging, we used the FDA-approved indocyanine green (ICG) dye as the contrast agent to target lipid-loaded macrophages. Firstly, IVUS is used as the first step for identifying plaque since IVUS enables the visualization of the layered structures of the artery wall. Due to low soft-tissue contrast, IVUS only provides initial identification of the lipid plaque. Then OCT is used for differentiating fibrosis and lipid pool based on its relatively higher soft tissue contrast and high sensitivity/specificity. Last, fluorescence imaging is used for identifying inflammatory reaction to further confirm whether the plaque is vulnerable or not. Ex vivo experiment of a male New Zealand white rabbit aorta was performed to validate the performance of our tri-modality system. H and E histology results of the rabbit aorta were also presented to check assessment accuracy. The miniature tri-modality probe, together with the use of ICG dye suggest that the system is of great potential for providing a more accurate assessment of vulnerable plaques in clinical applications.

Bone marrow endothelial progenitors in atherosclerotic plaque resolution

PubMed Central

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

Nuclear microscopy of diffuse plaques in the brains of transgenic mice

NASA Astrophysics Data System (ADS)

Rajendran, Reshmi; Ren, Minqin; Casadesus, Gemma; Smith, Mark A.; Perry, George; Huang, En; Ong, Wei Yi; Halliwell, Barry; Watt, Frank

2005-04-01

Using nuclear microscopy, extracellular diffuse amyloid deposits in fresh unstained brain tissue from Alzheimer's disease transgenic mice Tg2576 have been identified and analyzed for trace element content. Off-axis scanning transmission ion microscopy (STIM) images can be obtained which are similar to the images produced using direct STIM. Since the proton beam current required for off-axis STIM is compatible with PIXE and RBS, we can identify the plaque location and analyze for trace elements simultaneously. Analysis of the diffuse plaques showed an increase in the transition metals iron and zinc compared with the surrounding area of comparable areal density. This supports the theory that redox interactions between Aβ and metals could be at the heart of a pathological feedback system wherein Aβ amyloidosis and oxidative stress promote each other, possibly via Fenton chemistry.

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

PubMed Central

Slee, A M; O'Connor, J R

1983-01-01

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

3.0 T plaque imaging.

PubMed

Hinton-Yates, Denise P; Cury, Ricardo C; Wald, Lawrence L; Wiggins, Graham C; Keil, Boris; Seethmaraju, Ravi; Gangadharamurthy, Dakshinamurthy; Ogilvy, Christopher S; Dai, Guangping; Houser, Stuart L; Stone, James R; Furie, Karen L

2007-10-01

The aim of this article is to evaluate 3.0 T magnetic resonance imaging for characterization of vessel morphology and plaque composition. Emphasis is placed on early and moderate stages of carotid atherosclerosis, where increases in signal-to-noise (SNR) and contrast-to-noise (CNR) ratios compared with 1.5 T are sought. Comparison of in vivo 3.0 T imaging to histopathology is performed for validation. Parallel acceleration methods applied with an 8-channel carotid array are investigated as well as higher field ex vivo imaging to explore even further gains. The overall endeavor is to improve prospective assessment of atherosclerosis stage and stability for reduction of atherothrombotic event risk. A total of 10 male and female subjects ranging in age from 22 to 72 years (5 healthy and 5 with cardiovascular disease) participated. Custom-built array coils were used with endogenous and exogenous multicontrast bright and black-blood protocols for 3.0 T carotid imaging. Comparisons were performed to 1.5 T, and ex vivo plaque was stained with hematoxylin and eosin for histology. Imaging (9.4 T) was also performed on intact specimens. The factor of 2 gain in signal-to-noise SNR is realized compared with 1.5 T along with improved wall-lumen and plaque component CNR. Post-contrast black-blood imaging within 5-10 minutes of gadolinium injection is optimal for detection of the necrotic lipid component. In a preliminary 18-month follow-up study, this method provided measurement of a 50% reduction in lipid content with minimal change in plaque size in a subject receiving aggressive statin therapy. Parallel imaging applied with signal averaging further improves 3.0 T black-blood vessel wall imaging. The use of 3.0 T for carotid plaque imaging has demonstrated increases in SNR and CNR compared with 1.5 T. Quantitative prospective studies of moderate and early plaques are feasible at 3.0 T. Continued improvements in coil arrays, 3-dimensional pulse sequences, and the use of novel

Reduction of dental plaque formation by chlorhexidine dihydrochloride lozenges.

PubMed

Kaufman, A Y; Tal, H; Perlmutter, S; Shwartz, M M

1989-01-01

The effect of chlorhexidine dihydrochloride (chlorhex HCl) in lozenges on plaque growth was assessed on 21 subjects with fresh plaque of 7 days duration. The lozenges, which contained 5 mg chlorhex HCl, were sucked three times daily after meals, for 2 weeks. The study was a single-blind crossover. Placebo lozenges had all the ingredients except chlorhex HCl. These were used as a control. Results indicated that lozenges containing chlorhex HCl were a potent plaque inhibitor. The mean plaque score was reduced by 62.8% from an initial mean plaque score (DO) of 2.38 +/- 0.48 to (D7) 0.89 +/- 0.26 (p less than 0.0001), after 1 wk of usage. A further reduction to plaque score (D14) of 0.56 +/- 0.27 (p less than 0.0001) was recorded by the end of the 2nd wk. Usage of the placebo during the same time period did not show significant differences in the plaque score (DO = 2.38; D7 = 2.33; D14 = 2.42). Inhibition of plaque formation to the 1104 test surfaces revealed a total elimination of the higher levels of plaque (scores 4 and 5), a considerable reduction of the middle levels (scores 2 and 3) and a significant increase (44.7%) of low level plaque (score 1). Total elimination of plaque (score 0) was observed in 50.3% of the test group surfaces. Lozenges containing 5 mg chlorhexidine dihydrochloride, taken three times daily, were an efficient, comfortable and potent agent for reducing and inhibiting plaque formation. These lozenges are a more convenient alternative to chlorhexidine mouthrinses and may prove to be superior to these.

Mining Bug Databases for Unidentified Software Vulnerabilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumidu Wijayasekara; Milos Manic; Jason Wright

2012-06-01

Identifying software vulnerabilities is becoming more important as critical and sensitive systems increasingly rely on complex software systems. It has been suggested in previous work that some bugs are only identified as vulnerabilities long after the bug has been made public. These vulnerabilities are known as hidden impact vulnerabilities. This paper discusses the feasibility and necessity to mine common publicly available bug databases for vulnerabilities that are yet to be identified. We present bug database analysis of two well known and frequently used software packages, namely Linux kernel and MySQL. It is shown that for both Linux and MySQL, amore » significant portion of vulnerabilities that were discovered for the time period from January 2006 to April 2011 were hidden impact vulnerabilities. It is also shown that the percentage of hidden impact vulnerabilities has increased in the last two years, for both software packages. We then propose an improved hidden impact vulnerability identification methodology based on text mining bug databases, and conclude by discussing a few potential problems faced by such a classifier.« less

Quantitative T1 and T2* carotid atherosclerotic plaque imaging using a three-dimensional multi-echo phase-sensitive inversion recovery sequence: a feasibility study.

PubMed

Fujiwara, Yasuhiro; Maruyama, Hirotoshi; Toyomaru, Kanako; Nishizaka, Yuri; Fukamatsu, Masahiro

2018-06-01

Magnetic resonance imaging (MRI) is widely used to detect carotid atherosclerotic plaques. Although it is important to evaluate vulnerable carotid plaques containing lipids and intra-plaque hemorrhages (IPHs) using T 1 -weighted images, the image contrast changes depending on the imaging settings. Moreover, to distinguish between a thrombus and a hemorrhage, it is useful to evaluate the iron content of the plaque using both T 1 -weighted and T 2 *-weighted images. Therefore, a quantitative evaluation of carotid atherosclerotic plaques using T 1 and T 2 * values may be necessary for the accurate evaluation of plaque components. The purpose of this study was to determine whether the multi-echo phase-sensitive inversion recovery (mPSIR) sequence can improve T 1 contrast while simultaneously providing accurate T 1 and T 2 * values of an IPH. T 1 and T 2 * values measured using mPSIR were compared to values from conventional methods in phantom and in vivo studies. In the phantom study, the T 1 and T 2 * values estimated using mPSIR were linearly correlated with those of conventional methods. In the in vivo study, mPSIR demonstrated higher T 1 contrast between the IPH phantom and sternocleidomastoid muscle than the conventional method. Moreover, the T 1 and T 2 * values of the blood vessel wall and sternocleidomastoid muscle estimated using mPSIR were correlated with values measured by conventional methods and with values reported previously. The mPSIR sequence improved T 1 contrast while simultaneously providing accurate T 1 and T 2 * values of the neck region. Although further study is required to evaluate the clinical utility, mPSIR may improve carotid atherosclerotic plaque detection and provide detailed information about plaque components.

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

PubMed

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 (P<0.01). Intraclass correlation coefficients of the tooth area and plaque area which two researchers used the software to calculate were 0.956 and 0.930 (P<0.01).The Bland-Altman analysis chart 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.

Community and gene composition of a human dental plaque microbiota obtained by metagenomic sequencing

PubMed Central

Xie, G.; Chain, P.S.G.; Lo, C.; Liu, K-L.; Gans, J.; Merritt, J.; Qi, F.

2010-01-01

SUMMARY Human dental plaque is a complex microbial community containing an estimated 700 to 19,000 species/phylotypes. Despite numerous studies analysing species richness in healthy and diseased human subjects, the true genomic composition of the human dental plaque microbiota remains unknown. Here we report a metagenomic analysis of a healthy human plaque sample using a combination of second-generation sequencing platforms. A total of 860 million base pairs of non-human sequences were generated. Various analysis tools revealed the presence of 12 well-characterized phyla, members of the TM-7 and BRC1 clade, and sequences that could not be classified. Both pathogens and opportunistic pathogens were identified, supporting the ecological plaque hypothesis for oral diseases. Mapping the metagenomic reads to sequenced reference genomes demonstrated that 4% of the reads could be assigned to the sequenced species. Preliminary annotation identified genes belonging to all known functional categories. Interestingly, although 73% of the total assembled contig sequences were predicted to code for proteins, only 51% of them could be assigned a functional role. Furthermore, ~ 2.8% of the total predicted genes coded for proteins involved in resistance to antibiotics and toxic compounds, suggesting that the oral cavity is an important reservoir for antimicrobial resistance. PMID:21040513

Community and gene composition of a human dental plaque microbiota obtained by metagenomic sequencing.

PubMed

Xie, G; Chain, P S G; Lo, C-C; Liu, K-L; Gans, J; Merritt, J; Qi, F

2010-12-01

Human dental plaque is a complex microbial community containing an estimated 700 to 19,000 species/phylotypes. Despite numerous studies analysing species richness in healthy and diseased human subjects, the true genomic composition of the human dental plaque microbiota remains unknown. Here we report a metagenomic analysis of a healthy human plaque sample using a combination of second-generation sequencing platforms. A total of 860 million base pairs of non-human sequences were generated. Various analysis tools revealed the presence of 12 well-characterized phyla, members of the TM-7 and BRC1 clade, and sequences that could not be classified. Both pathogens and opportunistic pathogens were identified, supporting the ecological plaque hypothesis for oral diseases. Mapping the metagenomic reads to sequenced reference genomes demonstrated that 4% of the reads could be assigned to the sequenced species. Preliminary annotation identified genes belonging to all known functional categories. Interestingly, although 73% of the total assembled contig sequences were predicted to code for proteins, only 51% of them could be assigned a functional role. Furthermore, ~2.8% of the total predicted genes coded for proteins involved in resistance to antibiotics and toxic compounds, suggesting that the oral cavity is an important reservoir for antimicrobial resistance. © 2010 John Wiley & Sons A/S.

Dental plaque biofilm in oral health and disease.

PubMed

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

2011-01-01

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

Carotid Plaque Morphology in Asymptomatic Patients with and without Metabolic Syndrome.

PubMed

Cury, Marcus Vinícius Martins; Presti, Calógero; Bonadiman, Suellen Stevam Timotheo; Casella, Ivan Benaduce; Benabou, Joseph Elias; da Silva, Erasmo Simão; de Luccia, Nelson; Puech-Leão, Pedro

2017-02-01

The aim of this study was to determine the impact of metabolic syndrome (MetS) on the morphology of carotid plaques, as evaluated using duplex ultrasound (DUS) with computer-assisted analysis. In this cross-sectional observational study, we analyzed 148 carotid artery plaques in asymptomatic patients. Data were obtained via clinical and laboratory examinations, and DUS was performed by a single operator. All plaques were scanned in a longitudinal fashion, and the best segment was selected, recorded, and evaluated using dedicated software. The main software-based analyses included gray-scale median (GSM) measurements and carotid plaque morphology histograms. MetS was identified in 51.8% of patients. Comparisons of patients with MetS and patients without MetS indicated that the former patients used more classes of antihypertensive drugs (2.49 vs. 1.93; P = 0.004) and were treated with statins for a longer period (71.08 vs. 49.17 months; P = 0.003). Most patients of both types exhibited moderate carotid artery stenosis ranging from 50% to 69% (n = 62; 37.3%), and MetS was not associated with an increased prevalence of severe carotid artery stenosis. The mean GSM was greater in the MetS group than in the non-MetS group (74.18 vs. 61.63; P = 0.012). The histogram analysis revealed that there were lower quantities of blood and fat (2.91 vs. 3.88; P = 0.006; 10.21 vs. 15.08; P = 0.004, respectively) and more fibrous tissue (19.93 vs. 14.55; P = 0.015) in the carotid plaques of patients with MetS than in the carotid plaques of patients without MetS. The present study demonstrated that MetS did not affect the stenosis grade or did it lead to unstable carotid plaques. Copyright © 2016 Elsevier Inc. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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 (<0.13). Dual-wavelength analysis proved promising, with 1210 nm as the most successful primary wavelength (≈1.0). Results suggest that, without flushing the luminal 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.

The presence of Helicobacter pylori in dental plaque of children and their parents: is it related to their periodontal status and oral hygiene?

PubMed

Tsami, A; Petropoulou, P; Kafritsa, Y; Mentis, Y A; Roma-Giannikou, E

2011-12-01

To investigate the possible presence of H. pylori in subgingival dental plaque of children with upper gastrointestinal symptoms, as well as of their parents' and to detect any association between the presence of H. pylori and oral hygiene together with the periodontal status of children and their parents. The study comprised of 35 children with upper gastrointestinal symptoms, aged 4 to 14 years and 45 family members (mothers and/or fathers). Gastric biopsies were collected from all children for CLO-test, histology and culture. Serology was used to assess the H. pylori infection status of their parents. Before endoscopy, subgingival dental plaque from children and their parents were collected from 4 healthy and 4 diseased sites, and the clinical indices (gingival index, plaque index, bleeding on probing, pocket depth, loss of clinical attachment) after plaque collection were recorded. The Chi-square test was performed to investigate possible differences between children and their parents and logistic regression analysis was used to evaluate the association of parental infection status with that of children. 15 out of 35 children (42.86%) were found H. pylori-positive. In 6 out of the 15 infected children (40%) H. pylori was also identified in their subgingival plaque samples, as well as in one among the 20 non infected children. The presence of H. pylori in dental plaque was significantly associated with its presence in the gastric antrum (p=0.0274). H. pylori was identified in the dental plaque of 7 mothers corresponding to children with positive PCR in their dental plaque and of 4 fathers (one corresponding with his child found H. pylori positive in dental plaque). Children who had H. pylori identified in their dental plaque belonged to families with members also having H. pylori in dental plaque. No significant relationship between periodontal clinical parameters and detection of H. pylori in dental plaque in both children and their parents was found. However

WE-A-17A-12: The Influence of Eye Plaque Design On Dose Distributions and Dose- Volume Histograms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aryal, P; Molloy, JA; Rivard, MJ

Purpose: To investigate the effect of slot design of the model EP917 plaque on dose distributions and dose-volume histograms (DVHs). Methods: The dimensions and orientation of the slots in EP917 plaques were measured. In the MCNP5 radiation simulation geometry, dose distributions on orthogonal planes and DVHs for a tumor and sclera were generated for comparisons. 27 slot designs and 13 plaques were evaluated and compared with the published literature and the Plaque Simulator clinical treatment planning system. Results: The dosimetric effect of the gold backing composition and mass density was < 3%. Slot depth, width, and length changed the centralmore » axis (CAX) dose distributions by < 1% per 0.1 mm in design variation. Seed shifts in the slot towards the eye and shifts of the {sup 125} I-coated Ag rod within the capsule had the greatest impact on CAX dose distribution, increasing by 14%, 9%, 4%, and 2.5% at 1, 2, 5, and 10 mm, respectively, from the inner sclera. Along the CAX, dose from the full plaque geometry using the measured slot design was 3.4% ± 2.3% higher than the manufacturer-provided geometry. D{sub 10} for the simulated tumor, inner sclera, and outer sclera for the measured plaque was also higher, but 9%, 10%, and 20%, respectively. In comparison to the measured plaque design, a theoretical plaque having narrow and deep slots delivered 30%, 37%, and 62% lower D{sub 10} doses to the tumor, inner sclera, and outer sclera, respectively. CAX doses at −1, 0, 1, and 2 mm were also lower by a factor of 2.6, 1.4, 1.23, and 1.13, respectively. Conclusion: The study identified substantial sensitivity of the EP917 plaque dose distributions to slot design. However, it did not identify substantial dosimetric variations based on radionuclide choice ({sup 125}I, {sup 103}Pd, or {sup 131}Cs). COMS plaques provided lower scleral doses with similar tumor dose coverage.« less

A reduced astrocyte response to β-amyloid plaques in the ageing brain associates with cognitive impairment.

PubMed

Mathur, Ryan; Ince, Paul G; Minett, Thais; Garwood, Claire J; Shaw, Pamela J; Matthews, Fiona E; Brayne, Carol; Simpson, Julie E; Wharton, Stephen B

2015-01-01

β-amyloid (Aβ) plaques are a key feature of Alzheimer's disease pathology but correlate poorly with dementia. They are associated with astrocytes which may modulate the effect of Aβ-deposition on the neuropil. This study characterised the astrocyte response to Aβ plaque subtypes, and investigated their association with cognitive impairment. Aβ plaque subtypes were identified in the cingulate gyrus using dual labelling immunohistochemistry to Aβ and GFAP+ astrocytes, and quantitated in two cortical areas: the area of densest plaque burden and the deep cortex near the white matter border (layer VI). Three subtypes were defined for both diffuse and compact plaques (also known as classical or core-plaques): Aβ plaque with (1) no associated astrocytes, (2) focal astrogliosis or (3) circumferential astrogliosis. In the area of densest burden, diffuse plaques with no astrogliosis (β = -0.05, p = 0.001) and with focal astrogliosis (β = -0.27, p = 0.009) significantly associated with lower MMSE scores when controlling for sex and age at death. In the deep cortex (layer VI), both diffuse and compact plaques without astrogliosis associated with lower MMSE scores (β = -0.15, p = 0.017 and β = -0.81, p = 0.03, respectively). Diffuse plaques with no astrogliosis in layer VI related to dementia status (OR = 1.05, p = 0.025). In the area of densest burden, diffuse plaques with no astrogliosis or with focal astrogliosis associated with increasing Braak stage (β = 0.01, p<0.001 and β = 0.07, p<0.001, respectively), and ApoEε4 genotype (OR = 1.02, p = 0.001 and OR = 1.10, p = 0.016, respectively). In layer VI all plaque subtypes associated with Braak stage, and compact amyloid plaques with little and no associated astrogliosis associated with ApoEε4 genotype (OR = 1.50, p = 0.014 and OR = 0.10, p = 0.003, respectively). Reactive astrocytes in close proximity to either diffuse or compact plaques may have a neuroprotective role in the ageing brain, and possession of at

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrison, H; Menon, G; Jans, H

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 weremore » 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

Drinking habits are associated with changes in the dental plaque microbial community.

PubMed

Signoretto, Caterina; Bianchi, Franco; Burlacchini, Gloria; Sivieri, Francesca; Spratt, Dave; Canepari, Pietro

2010-02-01

Caries and gingivitis are the most prevalent oral infectious diseases of humans and are due to the accumulation of dental plaque (a microbial biofilm) on the tooth surface and at the gingival margin, respectively. Several in vitro and in vivo studies have shown that many natural components of foods and beverages inhibit the adhesion of and/or exert activity against oral bacteria. These biological activities have mainly been attributed to the polyphenol fraction. In order to explore the possibility that diet can alter the dental plaque community, in this study we evaluated the composition of the microbiota of supra- and subgingival plaque samples collected from 75 adult subjects with different drinking habits (drinkers of coffee, red wine, or water for at least 2 years) by analyzing the microbial population through the separation of PCR-amplified fragments using the denaturing gradient gel electrophoresis (DGGE) technique. The mean numbers of bands of the DGGE profiles from all three categories were evaluated. There were no significant differences between the two kinds of plaque collected from the control group (water drinkers), and this group showed the highest number of bands (supragingival plaque, 18.98 +/- 3.16 bands; subgingival plaque, 18.7 +/- 3.23 bands). The coffee and wine drinker groups generated the lowest numbers of bands for both supragingival plaque (coffee drinkers, 8.25 +/- 3.53 bands; wine drinkers, 7.93 +/- 2.55 bands) and subgingival plaque (coffee drinkers, 8.3 +/- 3.03 bands; wine drinkers, 7.65 +/- 1.68 bands). The differences between coffee drinkers or wine drinkers and the control group (water drinkers) were statistically significant. A total of 34 microorganisms were identified, and the frequency of their distribution in the three subject categories was analyzed. A greater percentage of subjects were positive for facultative aerobes when supragingival plaque was analyzed, while anaerobes were more frequent in subgingival plaque samples. It

Plaque reduction over time of an integrated oral hygiene system.

PubMed

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.

Social network characteristics and HIV vulnerability among transgender persons in San Salvador: identifying opportunities for HIV prevention strategies.

PubMed

Barrington, Clare; Wejnert, Cyprian; Guardado, Maria Elena; Nieto, Ana Isabel; Bailey, Gabriela Paz

2012-01-01

The purpose of this study is to improve understanding of HIV vulnerability and opportunities for HIV prevention within the social networks of male-to-female transgender persons in San Salvador, El Salvador. We compare HIV prevalence and behavioral data from a sample of gay-identified men who have sex with men (MSM) (n = 279), heterosexual or bisexual identified MSM (n = 229) and transgender persons (n = 67) recruited using Respondent Driven Sampling. Transgender persons consistently reported higher rates of HIV risk behavior than the rest of the study population and were significantly more likely to be involved in sex work. While transgender persons reported the highest rates of exposure to HIV educational activities they had the lowest levels of HIV-related knowledge. Transgender respondents' social networks were homophilous and efficient at recruiting other transgender persons. Findings suggest that transgender social networks could provide an effective and culturally relevant opportunity for HIV prevention efforts in this vulnerable population.

Social Network Characteristics and HIV Vulnerability Among Transgender Persons in San Salvador: Identifying Opportunities for HIV Prevention Strategies

PubMed Central

Barrington, Clare; Wejnert, Cyprian; Guardado, Maria Elena; Nieto, Ana Isabel; Bailey, Gabriela Paz

2013-01-01

The purpose of this study is to improve understanding of HIV vulnerability and opportunities for HIV prevention within the social networks of male-to-female transgender persons in San Salvador, El Salvador. We compare HIV prevalence and behavioral data from a sample of gay-identified men who have sex with men (MSM) (n = 279), heterosexual or bisexual identified MSM (n = 229) and transgender persons (n = 67) recruited using Respondent Driven Sampling. Transgender persons consistently reported higher rates of HIV risk behavior than the rest of the study population and were significantly more likely to be involved in sex work. While transgender persons reported the highest rates of exposure to HIV educational activities they had the lowest levels of HIV-related knowledge. Transgender respondents’ social networks were homophilous and efficient at recruiting other transgender persons. Findings suggest that transgender social networks could provide an effective and culturally relevant opportunity for HIV prevention efforts in this vulnerable population. PMID:21538082

Dental plaque removal with a novel battery-powered toothbrush.

PubMed

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).

Comparison of 16 mm OSU‐Nag and COMS eye plaques

PubMed Central

Davidorf, Frederick; Qi, Yujin

2012-01-01

OSU‐NAG eye plaques use fewer sources than COMS‐plaques of comparable size, and do not employ a Silastic seed carrier insert. Monte Carlo modeling was used to calculate 3D dose distributions for a 16 mm OSU‐NAG eye plaque and a 16 mm COMS eye plaque loaded with either Iodine‐125 or Cesium‐131 brachytherapy sources. The OSU‐NAG eye plaque was loaded with eight sources forming two squares, whereas the COMS eye plaque was loaded with thirteen sources approximating three isocentric circles. A spherical eyeball 24.6 mm in diameter and an ellipsoid‐like tumor 6 mm in height and 12 mm in the major and minor axes were used to evaluate the doses delivered. To establish a fair comparison, a water seed carrier was used instead of the Silastic seed carrier designed for the traditional COMS eye plaque. Calculations were performed on the dose distributions along the eye plaque axis and the DVHs of the tumor, as well as the 3D distribution. Our results indicated that, to achieve a prescription dose of 85 Gy at 6 mm from the inner sclera edge for a six‐day treatment, the OSU‐NAG eye plaque will need 6.16 U/source and 6.82 U/source for  125I and  131Cs, respectively. The COMS eye plaque will require 4.02 U/source and 4.43 U/source for the same source types. The dose profiles of the two types of eye plaques on their central axes are within 9% difference for all applicable distances. The OSU‐NAG plaque delivers about 10% and 12% more dose than the COMS for  125I and  131Cs sources, respectively, at the inner sclera edge, but 6% and 3% less dose at the opposite retina. The DVHs of the tumor for two types of plaques were within 6% difference. In conclusion, the dosimetric quality of the OSU‐NAG eye plaque used in eye plaque brachytherapy is comparable to the COMS eye plaque. PACS number: 87.56B, 87.55k, 87.55kh PMID:22584165

Alzheimer's disease: neuritic plaques and neurofibrillary tangles in human brain identified by FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Choo, Lin-P'ing; Jackson, Michael; Halliday, William C.; Mantsch, Henry H.

1994-01-01

The abnormal abundance of (beta) -amyloid plaques and neurofibrillary tangles are the hallmark of Alzheimer's disease (AD). Human central nervous system (CNS) grey matter was probed for characteristics arising from these pathological features. In AD but not normal grey matter, an IR band at 1615 cm-1 is seen, characteristic of a protein in an aggregated state. We speculate that this band arises from (beta) A4-amyloid protein. AD, and 18q- grey matter spectra show increased intensity of phosphate bands in accordance with known hyperphosphorylation of proteins found in neurofibrillary tangles. These spectral features may be useful in the diagnosis of AD.

Radiolabeled probes for imaging Alzheimer’s plaques

NASA Astrophysics Data System (ADS)

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

2005-12-01

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

Contemporary perspective on plaque control.

PubMed

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.

Computational Fluid Dynamics Simulations of Hemodynamics in Plaque Erosion

PubMed Central

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

2013-01-01

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

Functional expression of dental plaque microbiota.

PubMed

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

2014-01-01

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

Functional expression of dental plaque microbiota

PubMed Central

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

2014-01-01

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

Association between traditional cholesterol parameters, lipoprotein particle concentration, novel biomarkers and carotid plaques in retired National Football League players.

PubMed

Virani, Salim S; Pompeii, Lisa; Lincoln, Andrew E; Dunn, Reginald E; Tucker, Andrew M; Nambi, Vijay; Nasir, Khurram; Vogel, Robert A; Boone, Jeffrey L; Roberts, Arthur J; Ballantyne, Christie M

2012-06-01

We assessed whether low-density lipoprotein particle concentration (LDL-P) and high-sensitivity C-reactive protein [hs-CRP] can identify subclinical atherosclerosis better than traditional cholesterol parameters in retired National Football League (NFL) players. It is not known whether LDL-P and the biomarker hs-CRP can identify subclinical atherosclerosis better than low-density lipoprotein cholesterol (LDL-C) or non-high-density-lipoprotein cholesterol (non-HDL-C) in retired NFL players, given high prevalence of metabolic syndrome in these players. Carotid artery plaque screening was performed with traditional lipids, LDL-P, and hs-CRP in 996 retired players. Logistic regression analyses comparing highest with the lowest quartile were performed. Carotid artery plaques were seen in 41%. LDL-C (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.06-2.59), non-HDL-C (OR 1.67, 95% CI 1.04-2.67), and LDL-P (OR 2.21, 95% CI 1.35-3.62) were associated with plaques in adjusted models. Among 187 retired players with metabolic syndrome, LDL-C (OR 1.40, 95% CI 0.53-3.72) was not associated with carotid plaques, whereas LDL-P (OR 3.71, 95% CI 1.16-11.84) and non-HDL-C (OR 2.63, 95% CI 0.91-7.63, p=0.07; borderline significant) were associated with carotid plaques. hs-CRP (OR 1.13, 95% CI 0.71-1.79) was not associated with carotid plaques. Carotid artery plaques were common in retired NFL players and were strongly associated with LDL-P, especially among those with metabolic syndrome. hs-CRP was not associated with carotid plaques in this cohort. Published by Elsevier Ireland Ltd.

Association Between the Presence of Carotid Artery Plaque and Cardiovascular Events in Patients With Genetic Hypercholesterolemia.

PubMed

Bea, Ana M; Civeira, Fernando; Jarauta, Estíbaliz; Lamiquiz-Moneo, Itziar; Pérez-Calahorra, Sofía; Marco-Benedí, Victoria; Cenarro, Ana; Mateo-Gallego, Rocío

2017-07-01

The equations used in the general population to calculate cardiovascular risk are not useful in genetic hypercholesterolemia (GH). Carotid plaque detection has proved useful in cardiovascular prediction and risk reclassification but there have been no studies of its usefulness in GH. The aim of this study was to determine the association between the presence of carotid artery plaque and the occurrence of cardiovascular events in patients with GH. This study included 1778 persons with GH. The mean follow-up until the occurrence of cardiovascular events was 6.26 years. At presentation, the presence of carotid artery plaque was studied by high-resolution ultrasound. Carotid artery plaque was found in 661 (37.2%) patients: 31.9% with familial hypercholesterolemia, 39.8% with familial combined hyperlipidemia, 45.5% with dysbetalipoproteinemia, and 43.2% with polygenic hypercholesterolemia. During follow-up, 58 patients had a cardiovascular event. Event rates were 6354/100 000 (95%CI, 4432.4-8275.6) in the group with plaque and 1432/100 000 (95%CI, 730.6-2134.3) in the group without plaque, with significant differences between the 2 groups (P < .001). The relative risk of an event was 4.34 (95CI%, 2.44-7.71; P < .001) times higher in patients with plaque and was 2.40 (95%CI, 1.27-4.56; P = .007) times higher after adjustment for major risk factors. The number of carotid artery plaques was positively associated with the risk of cardiovascular events. Most cardiovascular events occur in a subgroup of patients who can be identified by carotid plaque detection. These results support the use of plaque screening in this population and should help in risk stratification and treatment in GH. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Relation of ABO Blood Groups to the Plaque Characteristic of Coronary Atherosclerosis.

PubMed

Huang, Xingtao; Zou, Yongpeng; Li, Lulu; Chen, Shuyuan; Hou, Jingbo; Yu, Bo

2017-01-01

The ABO blood types related to morphological characteristics of atherosclerosis plaque are not clear. We aimed to evaluate the relationship between ABO blood groups and the coronary plaque characteristic. We retrospectively identified the target lesions in 392 acute coronary syndrome patients who underwent optical coherence tomography examination before stenting. Subjects were divided into different groups according to different blood types. The fibrous cap thickness was significantly thicker in O type compared with non-O type (0.075 ± 0.033 mm versus 0.061 ± 0.024, p < 0.001). Meanwhile, the incidence of thin-cap fibroatheroma was also significantly higher in O type compared with non-O type (51.0% versus 71.5%, p < 0.001). The O type showed a significantly larger minimum lumen area [1.26 (0.82, 2.13) versus 1.05 (0.67, 1.82), p = 0.020] and minimum lumen diameter [1.03 (0.74, 1.31) versus 0.95 (0.66, 1.25), p = 0.039] compared with non-O type. There were no differences found in incidence of lipid plaque, plaque rupture, and thrombus between different blood type groups even between O type and non-O type group ( p > 0.05). The plaques of O type blood group were exhibited more stably compared with non-O type blood group. Moreover, the non-O type blood group have more serious coronary artery stenosis than O type blood group.

Dynamics of the microglial/amyloid interaction indicate a role in plaque maintenance.

PubMed

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

2008-04-16

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

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

PubMed Central

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

2008-01-01

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

Potential pathogenic aspects of denture plaque.

PubMed

Coulthwaite, L; Verran, J

2007-01-01

Oral health status declines with age and as a result the need for removable prostheses increases. Oral health is a reflection of one's general health, affecting the ability of an individual to eat and speak, and contributes significantly to a sense of confidence and well-being. Currently, there are 15 million denture wearers in the UK, representing a significant consumer base and a special healthcare consideration. The microbiology of denture plaque has received little attention in comparison with dental plaque, yet it differs in location and composition. Denture plaque and poor denture hygiene is associated with stomatitis (Candida infection), may also serve as a reservoir of potentially infectious pathogens, and may contribute to oral malodour and to caries and periodontitis in people who have remaining natural teeth. Oral bacteria have been implicated in bacterial endocarditis, aspiration pneumonia, gastrointestinal infection and chronic obstructive pulmonary disease, among others, and dentures offer a reservoir for microorganisms associated with these infections. An effective oral hygiene regimen is important to control denture plaque biofilm and contributes to the control of associated oral and systemic diseases.

Optimization of a Plaque Neutralization Test (PNT) to identify the exposure history of Pacific Herring to viral hemorrhagic septicemia virus (VHSV)

USGS Publications Warehouse

Hart, Lucas; Mackenzie, Ashley; Purcell, Maureen; Thompson, Rachel L.; Hershberger, Paul

2017-01-01

Methods for a plaque neutralization test (PNT) were optimized for the detection and quantification of viral hemorrhagic septicemia virus (VHSV) neutralizing activity in the plasma of Pacific Herring Clupea pallasii. The PNT was complement dependent, as neutralizing activity was attenuated by heat inactivation; further, neutralizing activity was mostly restored by the addition of exogenous complement from specific-pathogen-free Pacific Herring. Optimal methods included the overnight incubation of VHSV aliquots in serial dilutions (starting at 1:16) of whole test plasma containing endogenous complement. The resulting viral titers were then enumerated using a viral plaque assay in 96-well microplates. Serum neutralizing activity was virus-specific as plasma from viral hemorrhagic septicemia (VHS) survivors demonstrated only negligible reactivity to infectious hematopoietic necrosis virus, a closely related rhabdovirus. Among Pacific Herring that survived VHSV exposure, neutralizing activity was detected in the plasma as early as 37 d postexposure and peaked at approximately 64 d postexposure. The onset of neutralizing activity was slightly delayed in fish reared at 7.4°C relative to those in warmer temperatures (9.9°C and 13.1°C); however, neutralizing activity persisted for at least 345 d postexposure in all temperature treatments. It is anticipated that this novel ability to assess VHSV neutralizing activity in Pacific Herring will enable retrospective comparisons between prior VHS infections and year-class recruitment failures. Additionally, the optimized PNT could be employed as a forecasting tool capable of identifying the potential for future VHS epizootics in wild Pacific Herring populations.

Indocyanine Green Enables Near-Infrared Fluorescence Imaging of Lipid-Rich, Inflamed Atherosclerotic Plaques

PubMed Central

Vinegoni, Claudio; Botnaru, Ion; Aikawa, Elena; Calfon, Marcella A.; Iwamoto, Yoshiko; Folco, Eduardo J.; Ntziachristos, Vasilis; Weissleder, Ralph; Libby, Peter; Jaffer, Farouc A.

2011-01-01

New high-resolution molecular and structural imaging strategies are needed to visualize high-risk plaques that are likely to cause acute myocardial infarction, because current diagnostic methods do not reliably identify at-risk subjects. While molecular imaging agents are available for lower-resolution detection of atherosclerosis in large arteries, a lack of imaging agents coupled to high-resolution modalities has limited molecular imaging of atherosclerosis in the smaller coronary arteries [AU: ok? YES]. Here, we have demonstrated that indocyanine green (ICG), an FDA-approved near-infrared fluorescence (NIRF) emitting compound, targets atheromas within 20 minutes of injection and provides sufficient signal enhancement for in vivo detection of lipid-rich, inflamed, coronary-sized plaques in atherosclerotic rabbits. In vivo NIRF sensing was achieved with an intravascular wire in the aortae, a vessel of comparable caliber to human coronary arteries. Ex vivo fluorescence reflectance imaging studies showed high plaque target-to-background ratios in atheroma-bearing rabbits injected with ICG, compared to atheroma-bearing rabbits injected with saline. In vitro studies using human macrophages established that ICG preferentially targets lipid-loaded macrophages. In an early clinical study of human atheroma specimens from four patients, we found that ICG colocalized with plaque macrophages and lipids. The atheroma-targeting capability of ICG has the potential to accelerate the clinical development of NIRF molecular imaging of high-risk plaques in humans. PMID:21613624

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

PubMed

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.

Distinct signatures of dental plaque metabolic byproducts dictated by periodontal inflammatory status

PubMed Central

Sakanaka, Akito; Kuboniwa, Masae; Hashino, Ei; Bamba, Takeshi; Fukusaki, Eiichiro; Amano, Atsuo

2017-01-01

Onset of chronic periodontitis is associated with an aberrant polymicrobial community, termed dysbiosis. Findings regarding its etiology obtained using high-throughput sequencing technique suggested that dysbiosis holds a conserved metabolic signature as an emergent property. The purpose of this study was to identify robust biomarkers for periodontal inflammation severity. Furthermore, we investigated disease-associated metabolic signatures of periodontal microbiota using a salivary metabolomics approach. Whole saliva samples were obtained from adult subjects before and after removal of supragingival plaque (debridement). Periodontal inflamed surface area (PISA) was employed as an indicator of periodontal inflammatory status. Based on multivariate analyses using pre-debridement salivary metabolomics data, we found that metabolites associated with higher PISA included cadaverine and hydrocinnamate, while uric acid and ethanolamine were associated with lower PISA. Next, we focused on dental plaque metabolic byproducts by selecting salivary metabolites significantly decreased following debridement. Metabolite set enrichment analysis revealed that polyamine metabolism, arginine and proline metabolism, butyric acid metabolism, and lysine degradation were distinctive metabolic signatures of dental plaque in the high PISA group, which may be related to the metabolic signatures of disease-associated communities. Collectively, our findings identified potential biomarkers of periodontal inflammatory status and also provide insight into metabolic signatures of dysbiotic communities. PMID:28220901

Chemical Proteomics Identifies Druggable Vulnerabilities in a Genetically Defined Cancer.

PubMed

Bar-Peled, Liron; Kemper, Esther K; Suciu, Radu M; Vinogradova, Ekaterina V; Backus, Keriann M; Horning, Benjamin D; Paul, Thomas A; Ichu, Taka-Aki; Svensson, Robert U; Olucha, Jose; Chang, Max W; Kok, Bernard P; Zhu, Zhou; Ihle, Nathan T; Dix, Melissa M; Jiang, Ping; Hayward, Matthew M; Saez, Enrique; Shaw, Reuben J; Cravatt, Benjamin F

2017-10-19

The transcription factor NRF2 is a master regulator of the cellular antioxidant response, and it is often genetically activated in non-small-cell lung cancers (NSCLCs) by, for instance, mutations in the negative regulator KEAP1. While direct pharmacological inhibition of NRF2 has proven challenging, its aberrant activation rewires biochemical networks in cancer cells that may create special vulnerabilities. Here, we use chemical proteomics to map druggable proteins that are selectively expressed in KEAP1-mutant NSCLC cells. Principal among these is NR0B1, an atypical orphan nuclear receptor that we show engages in a multimeric protein complex to regulate the transcriptional output of KEAP1-mutant NSCLC cells. We further identify small molecules that covalently target a conserved cysteine within the NR0B1 protein interaction domain, and we demonstrate that these compounds disrupt NR0B1 complexes and impair the anchorage-independent growth of KEAP1-mutant cancer cells. Our findings designate NR0B1 as a druggable transcriptional regulator that supports NRF2-dependent lung cancers. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrasound Assessment of Carotid Plaque Echogenicity Response to Statin Therapy: A Systematic Review and Meta-Analysis

PubMed Central

Ibrahimi, Pranvera; Jashari, Fisnik; Bajraktari, Gani; Wester, Per; Henein, Michael Y.

2015-01-01

Objective: To evaluate in a systematic review and meta-analysis model the effect of statin therapy on carotid plaque echogenicity assessed by ultrasound. Methods: We have systematically searched electronic databases (PubMed, MEDLINE, EMBASE and Cochrane Center Register) up to April, 2015, for studies evaluating the effect of statins on plaque echogenicity. Two researchers independently determined the eligibility of studies evaluating the effect of statin therapy on carotid plaque echogenicity that used ultrasound and grey scale median (GSM) or integrated back scatter (IBS). Results: Nine out of 580 identified studies including 566 patients’ carotid artery data were meta-analyzed for a mean follow up of 7.2 months. A consistent increase in the echogenicity of carotid artery plaques, after statin therapy, was reported. Pooled weighted mean difference % (WMD) on plaque echogenicity after statin therapy was 29% (95% CI 22%–36%), p < 0.001, I2 = 92.1%. In a meta-regression analysis using % mean changes of LDL, HDL and hsCRP as moderators, it was shown that the effects of statins on plaque echogenicity were related to changes in hsCRP, but not to LDL and HDL changes from the baseline. The effect of statins on the plaque was progressive; it showed significance after the first month of treatment, and the echogenicity continued to increase in the following six and 12 months. Conclusions: Statin therapy is associated with a favorable increase of carotid plaque echogenicity. This effect seems to be dependent on the period of treatment and hsCRP change from the baseline, independent of changes in LDL and HDL. PMID:25984600

Improving interprofessional practice for vulnerable older people: gaining a better understanding of vulnerability.

PubMed

Abley, Clare; Bond, John; Robinson, Louise

2011-09-01

A key focus for professionals working with older people in the community is on those who are vulnerable, although this vulnerability is not well defined. This study sought the views of health and social care professionals and older people on vulnerability, identifying significant differences between professional and older people's perspectives. It found that for older people, vulnerability is an emotional response to being in a specific situation, whereas for professionals, the vulnerability of those on their case loads relates to them having certain or a combination of characteristics (physical, psychological and social). The paper concludes that interprofessional care for older people in the community could be improved firstly by asking older people if they ever feel vulnerable and if so, in what situations and secondly by focusing team efforts on addressing the issues raised by older people in response to these questions.

What We Have Learned from the Recent Meta-analyses on Diagnostic Methods for Atherosclerotic Plaque Regression.

PubMed

Biondi-Zoccai, Giuseppe; Mastrangeli, Simona; Romagnoli, Enrico; Peruzzi, Mariangela; Frati, Giacomo; Roever, Leonardo; Giordano, Arturo

2018-01-17

Atherosclerosis has major morbidity and mortality implications globally. While it has often been considered an irreversible degenerative process, recent evidence provides compelling proof that atherosclerosis can be reversed. Plaque regression is however difficult to appraise and quantify, with competing diagnostic methods available. Given the potential of evidence synthesis to provide clinical guidance, we aimed to review recent meta-analyses on diagnostic methods for atherosclerotic plaque regression. We identified 8 meta-analyses published between 2015 and 2017, including 79 studies and 14,442 patients, followed for a median of 12 months. They reported on atherosclerotic plaque regression appraised with carotid duplex ultrasound, coronary computed tomography, carotid magnetic resonance, coronary intravascular ultrasound, and coronary optical coherence tomography. Overall, all meta-analyses showed significant atherosclerotic plaque regression with lipid-lowering therapy, with the most notable effects on echogenicity, lipid-rich necrotic core volume, wall/plaque volume, dense calcium volume, and fibrous cap thickness. Significant interactions were found with concomitant changes in low density lipoprotein cholesterol, high density lipoprotein cholesterol, and C-reactive protein levels, and with ethnicity. Atherosclerotic plaque regression and conversion to a stable phenotype is possible with intensive medical therapy and can be demonstrated in patients using a variety of non-invasive and invasive imaging modalities.

Identifying Frailty Levels and Associated Factors in a Population Living in the Context of Poverty and Social Vulnerability.

PubMed

Zazzetta, M S; Gomes, G A O; Orlandi, F S; Gratão, A C M; Vasilceac, F A; Gramani-Say, K; Ponti, M A; Castro, P C; Pavarini, S C I; Menezes, A L C; Nascimento, C M C; Cominetti, M R

2017-01-01

This study aimed to investigate a vulnerable population living in the context of poverty in a Brazilian municipality, in order to identify the factors that are associated with frailty syndrome in elderly people. From the total population living in the area, a random sample of 363 community-dwelling people, 60 years and older, age and gender-stratified, was selected to participate in the research. After losses, a sample of 304 older adults was classified as non-frail, pre-frail and frail. According to the Fried frailty criteria, the prevalence was 12.2% for non-frail individuals, 60.5% pre-frail and 27.3% frail. The main factors associated with frailty in the studied sample were low level of physical activity (OR: 5.2, 95%CI: 2.5-11.0), the occurrence of two or more falls within 12 months (OR: 3.1, 95%CI: 1.4-7.1), mobility deficits (OR: 3.0, 95%CI: 1.5-5.8), and depressive symptoms (OR: 1.9, 95%CI: 1.1-3.7). This study identified the most important factors that must be evaluated to identify frailty syndrome in a socially vulnerable population in the context of poverty. The data should help to encourage effective strategies concerning public health policies for this population.

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

PubMed

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 < 0.0001). IVUS-VH analysis revealed that a nonculprit lesion with a plaque rupture was more often classified as a fibroatheroma than a nonculprit lesion without a plaque rupture (77.1% vs. 51.4%; p < 0.0001). Independent predictors of a plaque rupture were lesion length (per 10 mm; odds ratio: 1.30; p < 0.0001), plaque burden at the MLA site (per 10%; odds ratio: 2.56; p < 0.0001), vessel area at the MLA site (per 1 mm(2); odds ratio: 1.13; p < 0.0001), and VH-thin-cap fibroatheroma (odds ratio: 1.80; p = 0.016). During 3 years of follow-up, the incidence of overall major adverse cardiac events did not differ significantly between the patients with and patients without subclinical, nonculprit plaque ruptures. Secondary, nonculprit

Inhaled Diesel Emissions Alter Atherosclerotic Plaque Composition in ApoE−/− Mice

PubMed Central

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

2009-01-01

Recent epidemiological studies suggest that traffic-related air pollution may have detrimental effects on cardiovascular health. Previous studies reveal that gasoline emissions can induce several enzyme pathways involved in the formation and development of atherosclerotic plaques. As a direct comparison, the present study examined the impact of diesel engine emissions on these pathways, and further examined the effects on vascular lesion pathology. Apolipoprotein E-null mice were simultaneously placed on a high fat chow diet and exposed to four concentrations, plus a high concentration exposure with particulates (PM) removed by filtration, of diesel emissions for 6 h/d for 50 days. Aortas were subsequently assayed for alteration in matrix metalloproteinase-9, endothelin-1, and several other biomarkers. Diesel induced dose-related alterations in gene markers of vascular remodeling and aortic lipid peroxidation; filtration of PM did not significantly alter these vascular responses, indicating that the gaseous portion of the exhaust was a principal driver. Immunohistochemical analysis of aortic leaflet sections revealed no net increase in lesion area, but a significant decrease in lipid-rich regions and increasing trends in macrophage accumulation and collagen content, suggesting that plaques were advanced to a more fragile, potentially more vulnerable state by diesel exhaust exposure. Combined with previous studies, these results indicate that whole emissions from mobile sources may have a significant role in promoting chronic vascular disease. PMID:19891982

Resistant Atherosclerosis: The Need for Monitoring of Plaque Burden.

PubMed

Spence, J David; Solo, Karla

2017-06-01

Recent studies indicate that patients with lower levels of low-density lipoprotein cholesterol (LDL-C) have greater regression of coronary plaque. In 2002, we found that carotid plaque progression doubled cardiovascular risk. In 2003, we therefore implemented a new approach, treating arteries instead of risk factors. Since then, we have seen many patients with carotid plaque progression despite very low levels of LDL-C, suggesting other causes of atherosclerosis. We studied the relationship of achieved LDL-C and change in LDL-C to progression/regression of atherosclerosis, before and after 2003. All 4512 patients in our clinic database with at least 2 measurements of LDL-C and carotid total plaque area approximately a year apart and complete data for analyses (n=2025 before and 2487 after December 31, 2003) were included in the study. Baseline total plaque area was significantly higher after 2003 (129.56±134.32 versus 113.33±121.52 mm 2 ; P <0.0001), and plaque progression was significantly less after 2003 (2.94±37.11 versus 12.62±43.24 mm 2 ; P <0.0001). Many patients with LDL-C <1.8 mm had plaque progression (47.5%), and change in LDL-C was not correlated with plaque progression/regression. Increasing age and serum creatinine contributed to resistant atherosclerosis. Many patients have Resistant Atherosclerosis, failing to achieve regression of atherosclerosis despite low levels of LDL-C. Instead of relying on LDL-C, measuring plaque burden may be a more useful way of assessing individual response to therapy, particularly in resistant atherosclerosis. © 2017 American Heart Association, Inc.

The potential role of IDEAL MRI for identification of lipids and hemorrhage in carotid artery plaques.

PubMed

Khosa, Faisal; Clough, Rachel E; Wang, Xiaoen; Madhuranthakam, Ananth J; Greenman, Robert L

2018-06-01

Hemorrhage and lipid deposits contribute to instability in atherosclerotic plaques. Unstable carotid artery plaques can lead to cerebral ischemic events. While MRI studies have shown the ability to identify plaque components, the identification of hemorrhage and lipids has proven to be problematic. The purpose of this study was to quantitatively evaluate the potential of the MRI fat/water separation method known as iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL) to complement and improve existing methods for the identification of hemorrhage and lipids in carotid artery plaques. Fifteen asymptomatic subjects with 50-79% stenosis of at least one carotid artery were enrolled. Hemorrhage and lipid components within carotid plaques were identified using previously published criteria based on the multiple contrast-weighted (MCW) method (3D Time-of-Flight (3D-TOF), T1-Weighted (T1W) and T2-Weighted (T2W)). The hemorrhage:muscle, lipid:muscle and intra-plaque lipid:hemorrhage signal intensity ratios (SIR) and contrast to noise ratios (CNR) were measured on MCW and compared to IDEAL black-blood images. No differences were found between any of the MCW methods for any of the SIRs measured. The IDEAL Fat images had higher lipid:muscle and lipid/hemorrhage SIRs (p<0.001) compared to IDEAL Water and all MCW image sequence types. The mean values of IDEAL Fat hemorrhage:muscle SIR and CNR were nearly unity (1.1±0.6) and nearly zero (0.1±1.1), respectively. The IDEAL Water imaging was not significantly different than any of the MCW methods for any of the SIRs or for the hemorrhage:muscle CNR of 3D-TOF, while its CNRs were significantly higher than IDEAL Fat lipid:muscle (p<0.05) and lipid:hemorrhage (p<0.001) and all MCW methods (p<0.001). The addition of IDEAL Water and Fat imaging to the MCW method shows potential to improve the identification of hemorrhage and lipid structures in carotid artery plaques. Copyright © 2017

Tsunami survivors' perspectives on vulnerability and vulnerability reduction: evidence from Koh Phi Phi Don and Khao Lak, Thailand.

PubMed

Steckley, Marylynn; Doberstein, Brent

2011-07-01

This paper presents the results of primary research with 40 survivors of the 2004 Indian Ocean tsunami in two communities: Khao Lak (n=20) and Koh Phi Phi Don (n=20), Thailand. It traces tsunami survivors' perceptions of vulnerability, determines whether residents felt that the tsunami affected different communities differently, identifies the populations and sub-community groups that survivors distinguished as being more vulnerable than others, highlights community-generated ideas about vulnerability reduction, and pinpoints a range of additional vulnerability reduction actions. Tsunami survivors most consistently identified the 'most vulnerable' community sub-populations as women, children, the elderly, foreigners, and the poor. In Khao Lak, however, respondents added 'Burmese migrants' to this list, whereas in Koh Phi Phi Don, they added 'Thai Muslims'. Results suggest that the two case study communities, both small, coastal, tourism-dominated communities no more than 100 kilometres apart, have differing vulnerable sub-groups and environmental vulnerabilities, requiring different post-disaster vulnerability reduction efforts. © 2011 The Author(s). Disasters © Overseas Development Institute, 2011.

Reliability and discriminatory power of methods for dental plaque quantification

PubMed Central

RAGGIO, Daniela Prócida; BRAGA, Mariana Minatel; RODRIGUES, Jonas Almeida; FREITAS, Patrícia Moreira; IMPARATO, José Carlos Pettorossi; MENDES, Fausto Medeiros

2010-01-01

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. Conclusions The Turesky index and images with FC with disclosing present good reliability and discriminatory power in quantifying dental plaque. PMID:20485931

Efficacy of Statin Therapy in Inducing Coronary Plaque Regression in Patients with Low Baseline Cholesterol Levels

PubMed Central

Nozue, Tsuyoshi; Yamamoto, Shingo; Tohyama, Shinichi; Fukui, Kazuki; Umezawa, Shigeo; Onishi, Yuko; Kunishima, Tomoyuki; Sato, Akira; Miyake, Shogo; Morino, Yoshihiro; Yamauchi, Takao; Muramatsu, Toshiya; Hibi, Kiyoshi; Terashima, Mitsuyasu; Suzuki, Hiroshi; Michishita, Ichiro

2016-01-01

Aim: The efficacy of statin therapy in inducing coronary plaque regression may depend on baseline cholesterol levels. We aimed to determine the efficacy of statin therapy in inducing coronary plaque regression in statin-naïve patients with low cholesterol levels using serial intravascular ultrasound (IVUS) data from the treatment with statin on atheroma regression evaluated by virtual histology IVUS (TRUTH) study. Methods: The TRUTH study is a prospective, multicenter trial, comparing the efficacies of pitavastatin and pravastatin in coronary plaque regression in 164 patients. All patients were statin-naïve and received statin therapy only after study enrollment. The primary endpoint was the observation of coronary plaque progression, despite statin therapy. Results: Serial IVUS data, at baseline and after an 8-month follow-up, were available for 119 patients. The patients were divided into three groups based on non-high-density lipoprotein cholesterol (HDL-C) levels—low: ≤ 140 mg/dl, n = 38; moderate: 141–169 mg/dl, n = 42; and high: ≥ 170 mg/dl, n = 39. Coronary plaque progression was noted in the low cholesterol group, whereas plaque regression was noted in the moderate and high cholesterol groups [%Δplaque volume: 2.3 ± 7.4 vs. − 2.7 ± 10.7 vs. − 3.2 ± 7.5, p = 0.004 (analysis of variance)]. After adjusting for all variables, a low non-HDLC level (≤ 140 mg/dl) was identified as an independent predictor of coronary plaque progression [odds ratio, 3.7; 95% confidence interval, 1.5–9.1, p = 0.004]. Conclusion: Serial IVUS data analysis indicated that statin therapy was less effective in inducing coronary plaque regression in patients with low cholesterol levels but more effective in those with high cholesterol levels at baseline. University Hospital Medical Information Network (UMIN) (UMIN ID: C000000311). PMID:27040362

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

PubMed

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.

Aggregation and Disaggregation of Senile Plaques in Alzheimer Disease

NASA Astrophysics Data System (ADS)

Cruz, L.; Urbanc, B.; Buldyrev, S. V.; Christie, R.; Gomez-Isla, T.; Havlin, S.; McNamara, M.; Stanley, H. E.; Hyman, B. T.

1997-07-01

We quantitatively analyzed, using laser scanning confocal microscopy, the three-dimensional structure of individual senile plaques in Alzheimer disease. We carried out the quantitative analysis using statistical methods to gain insights about the processes that govern Aβ peptide deposition. Our results show that plaques are complex porous structures with characteristic pore sizes. We interpret plaque morphology in the context of a new dynamical model based on competing aggregation and disaggregation processes in kinetic steady-state equilibrium with an additional diffusion process allowing Aβ deposits to diffuse over the surface of plaques.

Release of mineral ions in dental plaque following acid production.

PubMed

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 < 0.01) from 1.9+/-0.5 to 5.0+/-2.1. 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.

Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

PubMed Central

Iyer, Nageshwar; Chandna, Shalu; Dhindsa, Abhishek; Damle, Dhanashree; Loomba, Ashish

2016-01-01

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 7th 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. PMID:27630494

A Quantitative Model of Early Atherosclerotic Plaques Parameterized Using In Vitro Experiments.

PubMed

Thon, Moritz P; Ford, Hugh Z; Gee, Michael W; Myerscough, Mary R

2018-01-01

There are a growing number of studies that model immunological processes in the artery wall that lead to the development of atherosclerotic plaques. However, few of these models use parameters that are obtained from experimental data even though data-driven models are vital if mathematical models are to become clinically relevant. We present the development and analysis of a quantitative mathematical model for the coupled inflammatory, lipid and macrophage dynamics in early atherosclerotic plaques. Our modeling approach is similar to the biologists' experimental approach where the bigger picture of atherosclerosis is put together from many smaller observations and findings from in vitro experiments. We first develop a series of three simpler submodels which are least-squares fitted to various in vitro experimental results from the literature. Subsequently, we use these three submodels to construct a quantitative model of the development of early atherosclerotic plaques. We perform a local sensitivity analysis of the model with respect to its parameters that identifies critical parameters and processes. Further, we present a systematic analysis of the long-term outcome of the model which produces a characterization of the stability of model plaques based on the rates of recruitment of low-density lipoproteins, high-density lipoproteins and macrophages. The analysis of the model suggests that further experimental work quantifying the different fates of macrophages as a function of cholesterol load and the balance between free cholesterol and cholesterol ester inside macrophages may give valuable insight into long-term atherosclerotic plaque outcomes. This model is an important step toward models applicable in a clinical setting.

Modelling farm vulnerability to flooding: A step toward vulnerability mitigation policies appraisal

NASA Astrophysics Data System (ADS)

Brémond, P.; Abrami, G.; Blanc, C.; Grelot, F.

2009-04-01

Recent catastrophic flood events such as Elbe in 2002 or Rhône in 2003 have shown limits of flood management policies relying on dykes protection: worsening of flood impacts downstream, increased damage by dykes rupture. Those events, among others, contributes to radical changes on the philosophy of flood prevention, with the promotion of new orientations for mitigating flood exposition. Two new trends may have a significant impact on rural areas: floodplain restoration and vulnerability mitigation. The Rhône River program, which is an contract of objectives signed between French Government and local collectivites, is highly illustrative of these new trends and their impact on agricultural sector. In this program, it appears that areas to be concerned by floodplain restoration are agricultural ones, because their supposed vulnerability to flood is expected to be less important to urban areas. As a consequence, agricultural sector is particularly concerned by planned actions on mitigation of assets vulnerability, an important part of the program (financial support of European Union of 7.5 Million euros). Mitigation of agricultural assets vulnerability reveals particularly interesting for two following reasons. Firstly, it is a way to maintain agricultural activities in floodplains yet existing, without promoting flood protection. Secondly, in case of floodplain restoration, vulnerability mitigation is a way for local authorities to compensate over-flooding impacts. In practice, local authorities may financially support farmers for implementing measures to mitigate their farm vulnerability. On the Rhône River, an important work has already been done to identify farm vulnerability to flooding, and propose measures to mitigate it. More than 3 000 farms exposed to flood risk have been identified representing 88 690 ha of agricultural areas which is estimated to generate damage between 400 and 800 Million euros depending on the season of occurrence for a catastrophic

Collagenolytic Activity of Dental Plaque Associated with Periodontal Pathology

PubMed Central

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

1974-01-01

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

Chlorhexidine mouthwash reduces plaque and gingivitis.

PubMed

Herrera, David

2013-03-01

Medline, Embase and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched along with the reference lists of all selected studies. Only English language studies were included. Randomised controlled clinical trials comparing chlorhexidine (CHX) to placebo/control mouthrinses for oral hygiene in studies of at least four weeks duration were included. Screening, selection and data abstractions were conducted independently by two reviewers. Where possible meta-analysis of weighted mean differences was carried out using fixed or random effects models where appropriate. Thirty studies were included, with 13 studies contributing to the meta-analysis. The meta-analysis found significant differences favouring CHX for a range of indices; the Plaque Index Silness & Löe, Plaque-Index Quigley & Hein (PIQH), the Gingival Index (GI), Papillary BIeeding Index, Bleeding on Marginal Probing and the Lobene Stain Index. Relative to control, the reduction with CHX for plaque was 33% and for gingivitis 26%. CHX rinsing groups demonstrated significantly more staining. In gingivitis patients, CHX mouthrinses together with OH versus placebo, or control mouthrinse provide significant reductions in plaque and gingivitis scores, but a significant increase in staining score.

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

PubMed

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 (<30 hounsfield units), positive remodeling (>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 <0.001) and NCB (�

A Cross-Sectional Survey of Bacterial Species in Plaque from Client Owned Dogs with Healthy Gingiva, Gingivitis or Mild Periodontitis

PubMed Central

Davis, Ian J.; Wallis, Corrin; Deusch, Oliver; Colyer, Alison; Milella, Lisa; Loman, Nick; Harris, Stephen

2013-01-01

Periodontal disease is the most widespread oral disease in dogs which if left untreated results in significant pain to the pet and loss of dentition. The objective of this study was to identify bacterial species in canine plaque that are significantly associated with health, gingivitis and mild periodontitis (<25% attachment loss). In this survey subgingival plaque samples were collected from 223 dogs with healthy gingiva, gingivitis and mild periodontitis with 72 to 77 samples per health status. DNA was extracted from the plaque samples and subjected to PCR amplification of the V1-V3 region of the 16S rDNA. Pyrosequencing of the PCR amplicons identified a total of 274 operational taxonomic units after bioinformatic and statistical analysis. Porphyromonas was the most abundant genus in all disease stages, particularly in health along with Moraxella and Bergeyella. Peptostreptococcus, Actinomyces, and Peptostreptococcaceae were the most abundant genera in mild periodontitis. Logistic regression analysis identified species from each of these genera that were significantly associated with health, gingivitis or mild periodontitis. Principal component analysis showed distinct community profiles in health and disease. The species identified show some similarities with health and periodontal disease in humans but also major differences. In contrast to human, healthy canine plaque was found to be dominated by Gram negative bacterial species whereas Gram positive anaerobic species predominate in disease. The scale of this study surpasses previously published research and enhances our understanding of the bacterial species present in canine subgingival plaque and their associations with health and early periodontal disease. PMID:24349448

A cross-sectional survey of bacterial species in plaque from client owned dogs with healthy gingiva, gingivitis or mild periodontitis.

PubMed

Davis, Ian J; Wallis, Corrin; Deusch, Oliver; Colyer, Alison; Milella, Lisa; Loman, Nick; Harris, Stephen

2013-01-01

Periodontal disease is the most widespread oral disease in dogs which if left untreated results in significant pain to the pet and loss of dentition. The objective of this study was to identify bacterial species in canine plaque that are significantly associated with health, gingivitis and mild periodontitis (<25% attachment loss). In this survey subgingival plaque samples were collected from 223 dogs with healthy gingiva, gingivitis and mild periodontitis with 72 to 77 samples per health status. DNA was extracted from the plaque samples and subjected to PCR amplification of the V1-V3 region of the 16S rDNA. Pyrosequencing of the PCR amplicons identified a total of 274 operational taxonomic units after bioinformatic and statistical analysis. Porphyromonas was the most abundant genus in all disease stages, particularly in health along with Moraxella and Bergeyella. Peptostreptococcus, Actinomyces, and Peptostreptococcaceae were the most abundant genera in mild periodontitis. Logistic regression analysis identified species from each of these genera that were significantly associated with health, gingivitis or mild periodontitis. Principal component analysis showed distinct community profiles in health and disease. The species identified show some similarities with health and periodontal disease in humans but also major differences. In contrast to human, healthy canine plaque was found to be dominated by Gram negative bacterial species whereas Gram positive anaerobic species predominate in disease. The scale of this study surpasses previously published research and enhances our understanding of the bacterial species present in canine subgingival plaque and their associations with health and early periodontal disease.

Definition of human rotavirus serotypes by plaque reduction assay.

PubMed Central

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

1982-01-01

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

Targetable vulnerabilities in T- and NK-cell lymphomas identified through preclinical models. | Office of Cancer Genomics

Cancer.gov

T- and NK-cell lymphomas (TCL) are a heterogenous group of lymphoid malignancies with poor prognosis. In contrast to B-cell and myeloid malignancies, there are few preclinical models of TCLs, which has hampered the development of effective therapeutics. Here we establish and characterize preclinical models of TCL. We identify multiple vulnerabilities that are targetable with currently available agents (e.g., inhibitors of JAK2 or IKZF1) and demonstrate proof-of-principle for biomarker-driven therapies using patient-derived xenografts (PDXs).

Bacterial Diversity and Community Structure of Supragingival Plaques in Adults with Dental Health or Caries Revealed by 16S Pyrosequencing

PubMed Central

Xiao, Cuicui; Ran, Shujun; Huang, Zhengwei; Liang, Jingping

2016-01-01

Dental caries has a polymicrobial etiology within the complex oral microbial ecosystem. However, the overall diversity and structure of supragingival plaque microbiota in adult dental health and caries are not well understood. Here, 160 supragingival plaque samples from patients with dental health and different severities of dental caries were collected for bacterial genomic DNA extraction, pyrosequencing by amplification of the 16S rDNA V1–V3 hypervariable regions, and bioinformatic analysis. High-quality sequences (2,261,700) clustered into 10,365 operational taxonomic units (OTUs; 97% identity), representing 453 independent species belonging to 122 genera, 66 families, 34 orders, 21 classes, and 12 phyla. All groups shared 7522 OTUs, indicating the presence of a core plaque microbiome. α diversity analysis showed that the microbial diversity in healthy plaques exceeded that of dental caries, with the diversity decreasing gradually with the severity of caries. The dominant phyla of plaque microbiota included Bacteroidetes, Actinobacteria, Proteobacteria, Firmicutes, Fusobacteria, and TM7. The dominant genera included Capnocytophaga, Prevotella, Actinomyces, Corynebacterium, Neisseria, Streptococcus, Rothia, and Leptotrichia. β diversity analysis showed that the plaque microbial community structure was similar in all groups. Using LEfSe analysis, 25 differentially abundant taxa were identified as potential biomarkers. Key genera (27) that potentially contributed to the differential distributions of plaque microbiota between groups were identified by PLS-DA analysis. Finally, co-occurrence network analysis and function predictions were performed. Treatment strategies directed toward modulating microbial interactions and their functional output should be further developed. PMID:27499752

Magnetic resonance angiography detection of abnormal carotid artery plaque in patients with cryptogenic stroke.

PubMed

Gupta, Ajay; Gialdini, Gino; Lerario, Michael P; Baradaran, Hediyeh; Giambrone, Ashley; Navi, Babak B; Marshall, Randolph S; Iadecola, Costantino; Kamel, Hooman

2015-06-15

Magnetic resonance imaging of carotid plaque can aid in stroke risk stratification in patients with carotid stenosis. However, the prevalence of complicated carotid plaque in patients with cryptogenic stroke is uncertain, especially as assessed by plaque imaging techniques routinely included in acute stroke magnetic resonance imaging protocols. We assessed whether the magnetic resonance angiography-defined presence of intraplaque high-intensity signal (IHIS), a marker of intraplaque hemorrhage, is associated with ipsilateral cryptogenic stroke. Cryptogenic stroke patients with magnetic resonance imaging evidence of unilateral anterior circulation infarction and without hemodynamically significant (≥50%) stenosis of the cervical carotid artery were identified from a prospective stroke registry at a tertiary-care hospital. High-risk plaque was assessed by evaluating for IHIS on routine magnetic resonance angiography source images using a validated technique. To compare the presence of IHIS on the ipsilateral versus contralateral side within individual patients, we used McNemar's test for correlated proportions. A total of 54 carotid arteries in 27 unique patients were included. A total of 6 patients (22.2%) had IHIS-positive nonstenosing carotid plaque ipsilateral to the side of ischemic stroke compared to 0 patients who had IHIS-positive carotid plaques contralateral to the side of stroke (P=0.01). Stroke severity measures, diagnostic evaluations, and prevalence of vascular risk factors were not different between the IHIS-positive and IHIS-negative groups. Our findings suggest that a proportion of strokes classified as cryptogenic may be mechanistically related to complicated, nonhemodynamically significant cervical carotid artery plaque that can easily be detected by routine magnetic resonance imaging/magnetic resonance angiography acute stroke protocols. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Aortic Arch Plaques and Risk of Recurrent Stroke and Death

PubMed Central

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

2010-01-01

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

Characterization of bacteriophage communities and CRISPR profiles from dental plaque

PubMed Central

2014-01-01

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

The effect of orthodontic bonding materials on dental plaque accumulation and composition in vitro.

PubMed

Badawi, H; Evans, R D; Wilson, M; Ready, D; Noar, J H; Pratten, J

2003-08-01

The aim of this study was to investigate the accumulation and composition of microcosm dental plaque on different orthodontic bonding materials using an in vitro model. Microcosm plaques were grown on discs of a range of bonding materials in a constant depth film fermentor. The biofilms were derived from human saliva and supplied with artificial saliva as a source of nutrients. The number of viable bacteria in the biofilms was determined and the streptococci present were identified to species level. The results showed that there was no significant difference in bacterial accumulation between different bonding materials, however, biofilms grown on materials which were fluoride releasing, did not contain Streptococcus mutans. This in vitro study has shown that the use of fluoride-releasing bonding materials may support the growth of supragingival plaque, which does not contain S. mutans.

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

PubMed

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 <0.05). There were no differences in minimum lumen area and area of calcium between 18 F-NaF-positive and 18 F-NaF-negative lesions. Among 51 lesions with 18 F-NaF-positive uptake, 48 lesions (94.1%) had at least one of high-risk 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 <0.001 for IVUS definition; 0.76 [95% confidence interval, 0.54-0.98] versus 0.42 [95% confidence interval, 0.21-0.62], P =0.014 for OCT definition). Among the 15 lesions that met both IVUS- and OCT-defined criteria for high-risk plaque, 14 (93.3%) showed 18 F-NaF-positive uptake. There was no difference in the prevalence of plaques with any adverse plaque characteristics between 18

Association between Randall's Plaque and Calcifying Nanoparticles

NASA Technical Reports Server (NTRS)

Ciftcioglu, Neva; Vejdani, Kaveh; Lee, Olivia; Mathew, Grace; Aho, Katja M.; Kajander, Olavi; McKay, David S.; Jones, Jeff A.; Hayat, Matthew; Stoller, Marshall L.

2007-01-01

Randall's plaques, first described by Alexander Randall in the 1930s, are small subepithelial calcifications in the renal papillae (RP) that also extend deeply into the renal medulla. Despite the strong correlation between the presence of these plaques and the formation of renal stones, the precise origin and pathogenesis of Randall s plaque formation remain elusive. The discovery of calcifying nanoparticles (CNP) and their detection in many calcifying processes of human tissues has raised hypotheses about their possible involvement in renal stone formation. We collected RP and blood samples from 17 human patients who had undergone laparoscopic nephrectomy due to neoplasia. Homogenized RP tissues and serum samples were cultured for CNP. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis were performed on fixed RP samples. Immunohistochemical staining (IHS) was applied on the tissue samples using CNP-specific monoclonal antibody (mAb). Randall s plaques were visible on gross inspection in 11 out of 17 collected samples. Cultures of all serum samples and 13 tissue homogenates had CNP growth within 4 weeks. SEM revealed spherical apatite formations in 14 samples, with calcium and phosphate peaks detected by EDS analysis. IHS was positive in 9 out of 17 samples. A strong link was found between the presence of Randall s plaques and the detection of CNP, also referred to as nanobacteria. These results suggest new insights into the etiology of Randall's plaque formation, and will help us understand the pathogenesis of stone formation. Further studies on this topic may lead us to new approaches on early diagnosis and novel medical therapies of kidney stone formation.

Gadolinium Enhancement in Intracranial Atherosclerotic Plaque and Ischemic Stroke: A Systematic Review and Meta-Analysis.

PubMed

Gupta, Ajay; Baradaran, Hediyeh; Al-Dasuqi, Khalid; Knight-Greenfield, Ashley; Giambrone, Ashley E; Delgado, Diana; Wright, Drew; Teng, Zhongzhao; Min, James K; Navi, Babak B; Iadecola, Costantino; Kamel, Hooman

2016-08-15

Gadolinium enhancement on high-resolution magnetic resonance imaging (MRI) has been proposed as a marker of inflammation and instability in intracranial atherosclerotic plaque. We performed a systematic review and meta-analysis to summarize the association between intracranial atherosclerotic plaque enhancement and acute ischemic stroke. We searched the medical literature to identify studies of patients undergoing intracranial vessel wall MRI for evaluation of intracranial atherosclerotic plaque. We recorded study data and assessed study quality, with disagreements in data extraction resolved by a third reader. A random-effects odds ratio was used to assess whether, in any given patient, cerebral infarction was more likely in the vascular territory supplied by an artery with MRI-detected plaque enhancement as compared to territory supplied by an artery without enhancement. We calculated between-study heterogeneity using the Cochrane Q test and publication bias using the Begg-Mazumdar test. Eight articles published between 2011 and 2015 met inclusion criteria. These studies provided information about plaque enhancement characteristics from 295 arteries in 330 patients. We found a significant positive relationship between MRI enhancement and cerebral infarction in the same vascular territory, with a random effects odds ratio of 10.8 (95% CI 4.1-28.1, P<0.001). No significant heterogeneity (Q=11.08, P=0.14) or publication bias (P=0.80) was present. Intracranial plaque enhancement on high-resolution vessel wall MRI is strongly associated with ischemic stroke. Evaluation for plaque enhancement on MRI may be a useful test to improve diagnostic yield in patients with ischemic strokes of undetermined etiology. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Plaque Echolucency and Stroke Risk in Asymptomatic Carotid Stenosis: A Systematic Review and Meta-Analysis

PubMed Central

Gupta, Ajay; Kesavabhotla, Kartik; Baradaran, Hediyeh; Kamel, Hooman; Pandya, Ankur; Giambrone, Ashley E.; Wright, Drew; Pain, Kevin J.; Mtui, Edward E.; Suri, Jasjit S.; Sanelli, Pina C.; Mushlin, Alvin I.

2014-01-01

Background and Purpose Ultrasonographic plaque echolucency has been studied as a stroke risk marker in carotid atherosclerotic disease. We performed a systematic review and meta-analysis to summarize the association between ultrasound determined carotid plaque echolucency and future ipsilateral stroke risk. Methods We searched the medical literature for studies evaluating the association between carotid plaque echolucency and future stroke in asymptomatic patients. We included prospective observational studies with stroke outcome ascertainment after baseline carotid plaque echolucency assessment. We performed a meta-analysis and assessed study heterogeneity and publication bias. We also performed subgroup analyses limited to patients with stenosis ≥50%, studies in which plaque echolucency was determined via subjective visual interpretation, studies with a relatively lower risk of bias, and studies published after the year 2000. Results We analyzed data from 7 studies on 7557 subjects with a mean follow up of 37.2 months. We found a significant positive relationship between predominantly echolucent (compared to predominantly echogenic) plaques and the risk of future ipsilateral stroke across all stenosis severities (0-99%) (relative risk [RR], 2.31, 95% CI, 1.58-3.39, P<.001) and in subjects with ≥50% stenosis (RR, 2.61 95% CI, 1.47-4.63, P=.001). A statistically significant increased RR for future stroke was preserved in all additional subgroup analyses. No statistically significant heterogeneity or publication bias was present in any of the meta-analyses. Conclusions The presence of ultrasound-determined carotid plaque echolucency provides predictive information in asymptomatic carotid artery stenosis beyond luminal stenosis. However, the magnitude of the increased risk is not sufficient on its own to identify patients likely to benefit from surgical revascularization. PMID:25406150

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

PubMed Central

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.

PubMed

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

Depletion of TDP-43 decreases fibril and plaque β-amyloid and exacerbates neurodegeneration in an Alzheimer's mouse model.

PubMed

LaClair, Katherine D; Donde, Aneesh; Ling, Jonathan P; Jeong, Yun Ha; Chhabra, Resham; Martin, Lee J; Wong, Philip C

2016-12-01

TDP-43 proteinopathy, initially associated with ALS and FTD, is also found in 30-60% of Alzheimer's disease (AD) cases and correlates with worsened cognition and neurodegeneration. A major component of this proteinopathy is depletion of this RNA-binding protein from the nucleus, which compromises repression of non-conserved cryptic exons in neurodegenerative diseases. To test whether nuclear depletion of TDP-43 may contribute to the pathogenesis of AD cases with TDP-43 proteinopathy, we examined the impact of depletion of TDP-43 in populations of neurons vulnerable in AD, and on neurodegeneration in an AD-linked context. Here, we show that some populations of pyramidal neurons that are selectively vulnerable in AD are also vulnerable to TDP-43 depletion in mice, while other forebrain neurons appear spared. Moreover, TDP-43 depletion in forebrain neurons of an AD mouse model exacerbates neurodegeneration, and correlates with increased prefibrillar oligomeric Aβ and decreased Aβ plaque burden. These findings support a role for nuclear depletion of TDP-43 in the pathogenesis of AD and provide strong rationale for developing novel therapeutics to alleviate the depletion of TDP-43 and functional antemortem biomarkers associated with its nuclear loss.

Fast detection of vascular plaque in optical coherence tomography images using a reduced feature set

NASA Astrophysics Data System (ADS)

Prakash, Ammu; Ocana Macias, Mariano; Hewko, Mark; Sowa, Michael; Sherif, Sherif

2018-03-01

Optical coherence tomography (OCT) images are capable of detecting vascular plaque by using the full set of 26 Haralick textural features and a standard K-means clustering algorithm. However, the use of the full set of 26 textural features is computationally expensive and may not be feasible for real time implementation. In this work, we identified a reduced set of 3 textural feature which characterizes vascular plaque and used a generalized Fuzzy C-means clustering algorithm. Our work involves three steps: 1) the reduction of a full set 26 textural feature to a reduced set of 3 textural features by using genetic algorithm (GA) optimization method 2) the implementation of an unsupervised generalized clustering algorithm (Fuzzy C-means) on the reduced feature space, and 3) the validation of our results using histology and actual photographic images of vascular plaque. Our results show an excellent match with histology and actual photographic images of vascular tissue. Therefore, our results could provide an efficient pre-clinical tool for the detection of vascular plaque in real time OCT imaging.

Combining OCT and a fluorescence intensity imaging method for atherosclerosis detection

NASA Astrophysics Data System (ADS)

Liang, Shanshan; Saidi, Arya; Jing, Joe; Liu, Gangjun; Yin, Jiechen; Narula, Jagat; Chen, Zhongping

2012-02-01

Coronary heart disease (like myocardial infarction) is caused by atherosclerosis. It cause over 30% of all deaths in North America and are the most common cause of death in European men under 65 years of age and the second most common cause in women. To diagnose this atherosclerosis before it gets rupture is the most effect way to increase the chance of survival for patients who suffer from this disease. The crucial tusk is how to find out vulnerable plaques. In resent years optical coherence tomography (OCT) has become a very useful tool for intravascular imaging, since it has high axial and transverse resolution. OCT can tell the detail structure inside the plaque like the thickness of plaque cap which is an important factor to identify vulnerable plaques. But we still need to find out the biochemical characteristics that is unique for vulnerable plaques (like inflammation). Fluorescence molecular imaging is a standard way to exam the biochemical property of biological samples. So we integrate these two techniques together into one probe. Our probe is comprised of a double-clad fiber (DCF) and a grin lens, and rotates with a micro mirror in front. The single-mode inner core of the DCF transmits both OCT and fluorescence excitation light, and the multimode inner cladding is used to detect fluorescence signal. In vitro result shows that this is a possible way for more accurate diagnose of vulnerable plaques.

Directional spatial frequency analysis of lipid distribution in atherosclerotic plaque

NASA Astrophysics Data System (ADS)

Korn, Clyde; Reese, Eric; Shi, Lingyan; Alfano, Robert; Russell, Stewart

2016-04-01

Atherosclerosis is characterized by the growth of fibrous plaques due to the retention of cholesterol and lipids within the artery wall, which can lead to vessel occlusion and cardiac events. One way to evaluate arterial disease is to quantify the amount of lipid present in these plaques, since a higher disease burden is characterized by a higher concentration of lipid. Although therapeutic stimulation of reverse cholesterol transport to reduce cholesterol deposits in plaque has not produced significant results, this may be due to current image analysis methods which use averaging techniques to calculate the total amount of lipid in the plaque without regard to spatial distribution, thereby discarding information that may have significance in marking response to therapy. Here we use Directional Fourier Spatial Frequency (DFSF) analysis to generate a characteristic spatial frequency spectrum for atherosclerotic plaques from C57 Black 6 mice both treated and untreated with a cholesterol scavenging nanoparticle. We then use the Cauchy product of these spectra to classify the images with a support vector machine (SVM). Our results indicate that treated plaque can be distinguished from untreated plaque using this method, where no difference is seen using the spatial averaging method. This work has the potential to increase the effectiveness of current in-vivo methods of plaque detection that also use averaging methods, such as laser speckle imaging and Raman spectroscopy.

Saliva and dental plaque.

PubMed

Rudney, J D

2000-12-01

Dental plaque is being redefined as oral biofilm. Diverse overlapping microbial consortia are present on all oral tissues. Biofilms are structured, displaying features like channels and projections. Constituent species switch back and forth between sessile and planktonic phases. Saliva is the medium for planktonic suspension. Several major functions can be defined for saliva in relation to oral biofilm. It serves as a medium for transporting planktonic bacteria within and between mouths. Bacteria in transit may be vulnerable to negative selection. Salivary agglutinins may prevent reattachment to surfaces. Killing by antimicrobial proteins may lead to attachment of dead cells. Salivary proteins form conditioning films on all oral surfaces. This contributes to positive selection for microbial adherence. Saliva carries chemical messengers which allow live adherent cells to sense a critical density of conspecifics. Growth begins, and thick biofilms may become resistant to antimicrobial substances. Salivary macromolecules may be catabolized, but salivary flow also may clear dietary substrates. Salivary proteins act in ways that benefit both host and microbe. All have multiple functions, and many do the same job. They form heterotypic complexes, which may exist in large micelle-like structures. These issues make it useful to compare subjects whose saliva functions differently. We have developed a simultaneous assay for aggregation, killing, live adherence, and dead adherence of oral species. Screening of 149 subjects has defined high killing/low adherence, low killing/high adherence, high killing/high adherence, and low killing/low adherence groups. These will be evaluated for differences in their flora.

Bacterial sex in dental plaque.

PubMed

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.

Optimization of K-edge imaging for vulnerable plaques using gold nanoparticles and energy resolved photon counting detectors: a simulation study.

PubMed

Alivov, Yahya; Baturin, Pavlo; Le, Huy Q; Ducote, Justin; Molloi, Sabee

2014-01-06

We investigated the effect of different imaging parameters, such as dose, beam energy, energy resolution and the number of energy bins, on the image quality of K-edge spectral computed tomography (CT) of gold nanoparticles (GNP) accumulated in an atherosclerotic plaque. A maximum likelihood technique was employed to estimate the concentration of GNP, which served as a targeted intravenous contrast material intended to detect the degree of the plaque's inflammation. The simulation studies used a single-slice parallel beam CT geometry with an x-ray beam energy ranging between 50 and 140 kVp. The synthetic phantoms included small (3 cm in diameter) cylinder and chest (33 × 24 cm(2)) phantoms, where both phantoms contained tissue, calcium and gold. In the simulation studies, GNP quantification and background (calcium and tissue) suppression tasks were pursued. The x-ray detection sensor was represented by an energy resolved photon counting detector (e.g., CdZnTe) with adjustable energy bins. Both ideal and more realistic (12% full width at half maximum (FWHM) energy resolution) implementations of the photon counting detector were simulated. The simulations were performed for the CdZnTe detector with a pixel pitch of 0.5-1 mm, which corresponds to a performance without significant charge sharing and cross-talk effects. The Rose model was employed to estimate the minimum detectable concentration of GNPs. A figure of merit (FOM) was used to optimize the x-ray beam energy (kVp) to achieve the highest signal-to-noise ratio with respect to the patient dose. As a result, the successful identification of gold and background suppression was demonstrated. The highest FOM was observed at the 125 kVp x-ray beam energy. The minimum detectable GNP concentration was determined to be approximately 1.06 µmol mL(-1) (0.21 mg mL(-1)) for an ideal detector and about 2.5 µmol mL(-1) (0.49 mg mL(-1)) for a more realistic (12% FWHM) detector. The studies show the optimal

Not the usual suspects: addressing layers of vulnerability.

PubMed

Luna, Florencia; Vanderpoel, Sheryl

2013-07-01

This paper challenges the traditional account of vulnerability in healthcare which conceptualizes vulnerability as a list of identifiable subpopulations. This list of 'usual suspects', focusing on groups from lower resource settings, is a narrow account of vulnerability. In this article we argue that in certain circumstances middle-class individuals can be also rendered vulnerable. We propose a relational and layered account of vulnerability and explore this concept using the case study of cord blood (CB) banking. In the first section, two different approaches to 'vulnerability' are contrasted: categorical versus layered. In the second section, we describe CB banking and present a case study of CB banking in Argentina. We examine the types of pressure that middle-class pregnant women feel when considering CB collection and storage. In section three, we use the CB banking case study to critique the categorical approach to vulnerability: this model is unable to account for the ways in which these women are vulnerable. A layered account of vulnerability identifies several ways in which middle-class women are vulnerable. Finally, by utilizing the layered approach, this paper suggests how public health policies could be designed to overcome vulnerabilities. © 2013 John Wiley & Sons Ltd.

Predictors of Plaque Rupture Within Nonculprit Fibroatheromas in Patients With Acute Coronary Syndromes: The PROSPECT Study.

PubMed

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

2015-10-01

The study sought to examine the relative importance of lesion location versus vessel area and plaque burden in predicting plaque rupture within nonculprit fibroatheromas (FAs) in patients with acute coronary syndromes. Previous studies have demonstrated that plaque rupture is associated with larger vessel area and greater plaque burden clustering in the proximal segments of coronary arteries. In the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study 3-vessel grayscale and radiofrequency-intravascular ultrasound was performed after successful percutaneous coronary intervention in 697 patients with acute coronary syndromes. Untreated nonculprit lesion FAs were classified as proximal (<20 mm), mid (20 to 40 mm), and distal (>40 mm) according to the distance from the ostium to the maximum necrotic core site. Overall, 74 ruptured FAs and 2,396 nonruptured FAs were identified in nonculprit vessels. The majority of FAs (73.6%) were located within 40 mm of the ostium, and the vessel area and plaque burden progressively decreased from proximal to distal FA location (both p < 0.001). In a multivariate logistic regression model, independent predictors for plaque rupture included the distance from the ostium to the maximum necrotic core site per millimeter (odds ratio [OR]: 0.86; 95% confidence interval [CI]: 0.76 to 0.98; p = 0.02), plaque burden per 10% (OR: 2.05; 95% CI: 1.63 to 2.58; p < 0.0001), vessel area per mm(2) (OR: 1.14; 95% CI: 1.11 to 1.17; p < 0.0001), calcium (OR: 0.09; 95% CI: 0.05 to 0.18; p < 0.0001), and right coronary artery location (OR: 2.16; 95% CI: 1.25 to 3.27; p = 0.006). By receiver-operating characteristic analysis, vessel area correlated with plaque rupture stronger than either plaque burden (p < 0.001) or location (p < 0.001). Large vessel area, plaque burden, proximal location, right coronary artery location, and lack of calcium were associated with FA plaque rupture. The present study suggests

Fluctuation between grandiose and vulnerable narcissism.

PubMed

Gore, Whitney L; Widiger, Thomas A

2016-10-01

Current literature on narcissistic personality disorder has emphasized a distinction between grandiose and vulnerable narcissism. Some researchers have further suggested that narcissistic persons fluctuate between grandiose and vulnerable narcissism. However, this perception has been confined largely to clinical experience with no systematic research testing the hypothesis. Clinicians and clinical psychology professors in the current study identified 143 persons who fit a description of either a grandiose or a vulnerable narcissist and indicated the extent to which these persons ever demonstrated traits of the complementary variant. The results supported the fluctuation hypothesis, particularly for episodes of vulnerable narcissism in persons identified as a grandiose narcissist. Correlations of the grandiose and vulnerable narcissism traits with a brief five-factor model measure corroborated past trait descriptions of the 2 respective variants of narcissism. The results of the current study are compared with existing cross-sectional and longitudinal research, and suggestions for future research are provided. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Plaque morphology detected with Duplex ultrasound before carotid angioplasty and stenting (CAS) is not a predictor of carotid artery in-stent restenosis, a case control study.

PubMed

Wasser, Katrin; Karch, André; Gröschel, Sonja; Witzenhausen, Janin; Gröschel, Klaus; Bähr, Mathias; Liman, Jan

2013-11-05

In-stent restenosis (ISR) is an important factor endangering the long-term safety and efficacy of carotid artery angioplasty and stenting (CAS). It is plausible that soft vulnerable plaques are more likely to be injured during CAS procedure and are therefore more likely to initiate the cascade finally leading to ISR. The aim of this study was to investigate if plaque morphology detected by a simple applicable Duplex ultrasound score before CAS can be used as a predictor for ISR. Within a prospectively collected single-centre CAS database of 281 patients (comprising 300 arteries) with high-grade carotid artery stenosis, who underwent CAS between May 2003 and January 2013, we conducted a nested case-control study. Plaque morphology before CAS was analysed by a blinded investigator and each parameter of the Total Plaque Risk Score (TPRS) as well as the whole score was evaluated with regard to its diagnostic validity for ISR. We analysed the data of 10 patients with ISR and 50 patients without ISR. There were no significant differences with respect to baseline characteristics, vascular risk factors, and degree of stenosis between patients with and without ISR. The duration of follow-up was longer in patients with ISR (p = 0.024) and these patients were more likely to show increased PSV (p = 0.012) immediately after CAS than patients without ISR. Neither individual parameters of the TPRS score nor the score as a whole were suitable as a diagnostic test for ISR development. In the present study we could demonstrate that the non-contrast enhanced DUS of the pre-interventional plaque formation cannot be used as a predictor for the development of ISR. Evaluating a more sophisticated, but not routinely available approach e.g. by ultrasound based plaque perfusion imaging or CT based plaque analysis could be helpful in the future in order to assess the role of plaque morphology in the context of ISR development.

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

NASA Astrophysics Data System (ADS)

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

2013-06-01

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

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

PubMed

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 (p<0.05) and lower the adherence ability (p<0.003) towards experimental pellicles. Combination between Gt and Sp aqueous extracts exhibited synergistic anti-plaque activity, and could be used as a useful active agent to produce oral health care products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of the K-edge imaging for vulnerable plaques using gold nanoparticles and energy-resolved photon counting detectors: a simulation study

PubMed Central

Alivov, Yahya; Baturin, Pavlo; Le, Huy Q.; Ducote, Justin; Molloi, Sabee

2014-01-01

We investigated the effect of different imaging parameters such as dose, beam energy, energy resolution, and number of energy bins on image quality of K-edge spectral computed tomography (CT) of gold nanoparticles (GNP) accumulated in an atherosclerotic plaque. Maximum likelihood technique was employed to estimate the concentration of GNP, which served as a targeted intravenous contrast material intended to detect the degree of plaque's inflammation. The simulations studies used a single slice parallel beam CT geometry with an X-ray beam energy ranging between 50 and 140 kVp. The synthetic phantoms included small (3 cm in diameter) cylinder and chest (33x24 cm2) phantom, where both phantoms contained tissue, calcium, and gold. In the simulation studies GNP quantification and background (calcium and tissue) suppression task were pursued. The X-ray detection sensor was represented by an energy resolved photon counting detector (e.g., CdZnTe) with adjustable energy bins. Both ideal and more realistic (12% FWHM energy resolution) implementations of photon counting detector were simulated. The simulations were performed for the CdZnTe detector with pixel pitch of 0.5-1 mm, which corresponds to the performance without significant charge sharing and cross-talk effects. The Rose model was employed to estimate the minimum detectable concentration of GNPs. A figure of merit (FOM) was used to optimize the X-ray beam energy (kVp) to achieve the highest signal-to-noise ratio (SNR) with respect to patient dose. As a result, the successful identification of gold and background suppression was demonstrated. The highest FOM was observed at 125 kVp X-ray beam energy. The minimum detectable GNP concentration was determined to be approximately 1.06 μmol/mL (0.21 mg/mL) for an ideal detector and about 2.5 μmol/mL (0.49 mg/mL) for more realistic (12% FWHM) detector. The studies show the optimal imaging parameters at lowest patient dose using an energy resolved photon counting detector

A Framework for Local Mechanical Characterization of Atherosclerotic Plaques: Combination of Ultrasound Displacement Imaging and Inverse Finite Element Analysis.

PubMed

Akyildiz, Ali C; Hansen, Hendrik H G; Nieuwstadt, Harm A; Speelman, Lambert; De Korte, Chris L; van der Steen, Antonius F W; Gijsen, Frank J H

2016-04-01

Biomechanical models have the potential to predict plaque rupture. For reliable models, correct material properties of plaque components are a prerequisite. This study presents a new technique, where high resolution ultrasound displacement imaging and inverse finite element (FE) modeling is combined, to estimate material properties of plaque components. Iliac arteries with plaques were excised from 6 atherosclerotic pigs and subjected to an inflation test with pressures ranging from 10 to 120 mmHg. The arteries were imaged with high frequency 40 MHz ultrasound. Deformation maps of the plaques were reconstructed by cross correlation of the ultrasound radiofrequency data. Subsequently, the arteries were perfusion fixed for histology and structural components were identified. The histological data were registered to the ultrasound data to construct FE model of the plaques. Material properties of the arterial wall and the intima of the atherosclerotic plaques were estimated using a grid search method. The computed displacement fields showed good agreement with the measured displacement fields, implying that the FE models were able to capture local inhomogeneities within the plaque. On average, nonlinear stiffening of both the wall and the intima was observed, and the wall of the atheroslcerotic porcine iliac arteries was markedly stiffer than the intima (877 ± 459 vs. 100 ± 68 kPa at 100 mmHg). The large spread in the data further illustrates the wide variation of the material properties. We demonstrated the feasibility of a mixed experimental-numerical framework to determine the material properties of arterial wall and intima of atherosclerotic plaques from intact arteries, and concluded that, due to the observed variation, plaque specific properties are required for accurate stress simulations.

Identification of vulnerability within a child and family health service.

PubMed

Kimla, Katarina; Nathanson, Dania; Woolfenden, Susan; Zwi, Karen

2017-11-21

Objective The aims of the present study were to describe the prevalence of vulnerability in a cohort of newborns, identify the factors that increase the risk of vulnerability and examine whether those who are most vulnerable are receiving home visits. Methods A prospective cross-sectional study was performed using data collected from questionnaires completed by child and family health nurses and obstetric discharge summaries for each mother-baby dyad. Descriptive frequencies and percentages are used to describe the proportions of children who were vulnerable, offered services and had risk factors for vulnerability. Categorical data were compared using Pearson's Chi-squared analysis. Results In all, 1517 newborns were included in the present study. Of these, 40.5% were identified as vulnerable and 13.9% had two or more risk factors for vulnerability (95% confidence interval (CI) 12-16%). The most common risk factors were biological. Across all newborns, 33.7% were visited at home, and 74.6% of vulnerable newborns were offered a home visit. Children identified as vulnerable were more likely to have a home visit than those who were not (z for 95% CI=1.96; P<0.1). Conclusions Although the high reported prevalence of identified risk needs to be confirmed in further studies, identifying vulnerability allowed the offer of home visiting to be directed towards those most likely to benefit. What is known about the topic? Of the Australian child population, 10-20% are vulnerable to adverse health, developmental and wellbeing outcomes. Vulnerable infants are at a greater risk of becoming vulnerable children, adolescents and adults over the life course. Biological and psychosocial risk factors for vulnerability are well described. Families with the greatest need are often the least likely to access or receive support, and have lower utilisation of preventative health services despite evidence that support in the first few years of life can significantly improve long

An Extreme-Value Approach to Anomaly Vulnerability Identification

NASA Technical Reports Server (NTRS)

Everett, Chris; Maggio, Gaspare; Groen, Frank

2010-01-01

The objective of this paper is to present a method for importance analysis in parametric probabilistic modeling where the result of interest is the identification of potential engineering vulnerabilities associated with postulated anomalies in system behavior. In the context of Accident Precursor Analysis (APA), under which this method has been developed, these vulnerabilities, designated as anomaly vulnerabilities, are conditions that produce high risk in the presence of anomalous system behavior. The method defines a parameter-specific Parameter Vulnerability Importance measure (PVI), which identifies anomaly risk-model parameter values that indicate the potential presence of anomaly vulnerabilities, and allows them to be prioritized for further investigation. This entails analyzing each uncertain risk-model parameter over its credible range of values to determine where it produces the maximum risk. A parameter that produces high system risk for a particular range of values suggests that the system is vulnerable to the modeled anomalous conditions, if indeed the true parameter value lies in that range. Thus, PVI analysis provides a means of identifying and prioritizing anomaly-related engineering issues that at the very least warrant improved understanding to reduce uncertainty, such that true vulnerabilities may be identified and proper corrective actions taken.

Assessing the use of Quantitative Light-induced Fluorescence-Digital as a clinical plaque assessment.

PubMed

Han, Sun-Young; Kim, Bo-Ra; Ko, Hae-Youn; Kwon, Ho-Keun; Kim, Baek-Il

2016-03-01

The aims of this study were to compare the relationship between red fluorescent plaque (RF plaque) area by Quantitative Light-induced Fluorescence-Digital (QLF-D) and disclosed plaque area by two-tone disclosure, and to assess the bacterial composition of the RF plaque by real time-PCR. Fifty healthy subjects were included and 600 facial surfaces of their anterior teeth were examined. QLF-D was taken on two separate occasions (before and after disclosing), and the RF plaque area was calculated based on Plaque Percent Index (PPI). After disclosing, the stained plaque area was analyzed to investigate the relationship with the RF plaque area. The relationship was evaluated using Pearson correlation and paired t-test. Then, the RF and non-red fluorescent (non-RF) plaque samples were obtained from the same subject for real-time PCR test. Total 10 plaque samples were compared the ratio of the 6 of bacteria using Wilcoxon signed rank test. Regarding the paired t-test, the blue-staining plaque area (9.3±9.2) showed significantly similarity with the RF plaque area (9.1±14.9, p=0.80) at ΔR20, however, the red-staining plaque area (31.6±20.9) presented difference from the RF plaque area (p<0.0001). In addition, bacterial composition of Prevotella intermedia and Streptococcus anginosus was associated with substantially more the RF plaque than the non-RF plaque (p<0.05). The plaque assessment method using QLF-D has potential to detect mature plaque, and the plaque area was associated with the blue-staining area using two-tone disclosure. Copyright © 2015 Elsevier B.V. All rights reserved.

Plaque which Apollo 11 astronauts will leave on the moon

NASA Image and Video Library

1969-07-14

S69-39334 (July 1969) --- This is a replica of the plaque which the Apollo 11 astronauts will leave behind on the moon in commemoration of the historic event. The plaque is made of stainless steel, measuring nine by seven and five-eighths inches, and one-sixteenth inch thick. The plaque will be attached to the ladder on the landing gear strut on the descent stage of the Apollo 11 Lunar Module (LM). Covering the plaque during the flight will be a thin sheet of stainless steel which will be removed on the lunar surface.

Shield ulcers and plaques of the cornea in vernal keratoconjunctivitis.

PubMed

Cameron, J A

1995-06-01

Shield-shaped corneal ulcers and plaques are serious sight-threatening corneal manifestations of vernal keratoconjunctivitis. There are few reports describing the management of these patients and their outcomes. The clinical presentation, treatment, and outcome of 66 shield ulcers and/or plaques in 55 eyes of 41 patients with vernal keratoconjunctivitis were studied in this retrospective study of patients treated at King Khaled Eye Specialist Hospital during an 11-year period. Patients with shield ulcers where the base of the ulcer was transparent usually had rapid re-epithelialization and an excellent visual outcome with medical treatment alone. Patients with shield ulcers and visible plaque formation had delayed re-epithelialization when receiving only medical treatment. Complications of delayed re-epithelialization consisted of bacterial keratitis in five eyes, amblyopia in one eye, and strabismus in one patient. Patients with shield ulcers and/or plaques that do not re-epithelialize once active vernal keratoconjunctivitis has been controlled should have surgical intervention. In this series, a simple scraping of the base and margins of the ulcer with removal of the inflammatory material (i.e., the plaque) resulted in rapid re-epithelialization in 20 of 23 ulcers and plaques. An algorithm for treating shield ulcers and/or plaques is presented based on the experience at this institution.

Identifying vulnerable populations to death and injuries from residential fires.

PubMed

Gilbert, Stanley W; Butry, David T

2017-08-03

This study proposes and evaluates the theory that people who are susceptible to injury in residential fires are not susceptible to death in residential fires and vice versa. It is proposed that the population vulnerable to death in residential fires can be proxied by 'frailty', which is measured as age-gender adjusted fatality rates due to natural causes. This study uses an ecological approach and controls for exposure to estimate the vulnerability of different population groups to death and injury in residential fires. It allows fatalities and injuries to be estimated by different models. Frailty explains fire-related death in adults while not explaining injuries, which is consistent with the idea that deaths and injuries affect disjoint populations. Deaths and injuries in fire are drawn from different populations. People who are susceptible to dying in fires are unlikely to be injured in fires, and the people who are susceptible to injury are unlikely to die in fires. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Multi-dimensional flood vulnerability assessment using data envelopment analysis

NASA Astrophysics Data System (ADS)

Zahid, Zalina; Saharizan, Nurul Syuhada; Hamzah, Paezah; Hussin, Siti Aida Sheikh; Khairi, Siti Shaliza Mohd

2017-11-01

Malaysia has been greatly impacted by flood during monsoon seasons. Even though flood prone areas are well identified, assessment on the vulnerability of the disaster is lacking. Assessment of flood vulnerability, defined as the potential for loss when a disaster occurs, is addressed in this paper. The focus is on the development of flood vulnerability measurement in 11 states in Peninsular Malaysia using a non-parametric approach of Data Envelopment Analysis. Scores for three dimensions of flood vulnerability (Population Vulnerability, Social Vulnerability and Biophysical) were calculated using secondary data of selected input and output variables across an 11-year period from 2004 to 2014. The results showed that Johor and Pahang were the most vulnerable to flood in terms of Population Vulnerability, followed by Kelantan, the most vulnerable to flood in terms of Social Vulnerability and Kedah, Pahang and Terengganu were the most vulnerable to flood in terms of Biophysical Vulnerability among the eleven states. The results also showed that the state of Johor, Pahang and Kelantan to be most vulnerable across the three dimensions. Flood vulnerability assessment is important as it provides invaluable information that will allow the authority to identify and develop plans for flood mitigation and to reduce the vulnerability of flood at the affected regions.

Identifying regions vulnerable to habitat degradation under future irrigation scenarios

NASA Astrophysics Data System (ADS)

Terrado, Marta; Sabater, Sergi; Acuña, Vicenç

2016-11-01

The loss and degradation of natural habitats is a primary cause of biodiversity decline. The increasing impacts of climate and land use change affect water availability, ultimately decreasing agricultural production. Areas devoted to irrigation have been increased to compensate this reduction, causing habitat and biodiversity losses, especially in regions undergoing severe water stress. These effects might intensify under global change, probably contributing to a decrease in habitat quality. We selected four European river basins across a gradient of water scarcity and irrigation agriculture. The habitat quality in the basins was assessed as a function of habitat suitability and threats under current and future global change scenarios of irrigation. Results revealed that the most threatened regions under future scenarios of global change were among those suffering of water scarcity and with bigger areas devoted to irrigation. Loss of habitat quality reached 10% in terrestrial and 25% in aquatic ecosystems under climate change scenarios involving drier conditions. The aquatic habitats were the most degraded in all scenarios, since they were affected by threats from both the terrestrial and the aquatic parts of the basin. By identifying in advance the regions most vulnerable to habitat and biodiversity loss, our approach can assist decision makers in deciding the conservation actions to be prioritized for mitigation and adaptation to the effects of climate change, particularly front the development of irrigation plans.

Attenuating astrocyte activation accelerates plaque pathogenesis in APP/PS1 mice

PubMed Central

Kraft, Andrew W.; Hu, Xiaoyan; Yoon, Hyejin; Yan, Ping; Xiao, Qingli; Wang, Yan; Gil, So Chon; Brown, Jennifer; Wilhelmsson, Ulrika; Restivo, Jessica L.; Cirrito, John R.; Holtzman, David M.; Kim, Jungsu; Pekny, Milos; Lee, Jin-Moo

2013-01-01

The accumulation of aggregated amyloid-β (Aβ) in amyloid plaques is a neuropathological hallmark of Alzheimer's disease (AD). Reactive astrocytes are intimately associated with amyloid plaques; however, their role in AD pathogenesis is unclear. We deleted the genes encoding two intermediate filament proteins required for astrocyte activation—glial fibrillary acid protein (Gfap) and vimentin (Vim)—in transgenic mice expressing mutant human amyloid precursor protein and presenilin-1 (APP/PS1). The gene deletions increased amyloid plaque load: APP/PS1 Gfap−/−Vim−/− mice had twice the plaque load of APP/PS1 Gfap+/+Vim+/+ mice at 8 and 12 mo of age. APP expression and soluble and interstitial fluid Aβ levels were unchanged, suggesting that the deletions had no effect on APP processing or Aβ generation. Astrocyte morphology was markedly altered by the deletions: wild-type astrocytes had hypertrophied processes that surrounded and infiltrated plaques, whereas Gfap−/−Vim−/− astrocytes had little process hypertrophy and lacked contact with adjacent plaques. Moreover, Gfap and Vim gene deletion resulted in a marked increase in dystrophic neurites (2- to 3-fold higher than APP/PS1 Gfap+/+Vim+/+ mice), even after normalization for amyloid load. These results suggest that astrocyte activation limits plaque growth and attenuates plaque-related dystrophic neurites. These activities may require intimate contact between astrocyte and plaque.—Kraft, A. W., Hu, X., Yoon, H., Yan, P., Xiao, Q., Wang, Y., Gil, S. C., Brown, J., Wilhelmsson, U., Restivo, J. L., Cirrito, J. R., Holtzman, D. M., Kim, J., Pekny, M., Lee, J.-M. Attenuating astrocyte activation accelerates plaque pathogenesis in APP/PS1 mice. PMID:23038755

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

PubMed

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.

Metabolomic Effects of Xylitol and Fluoride on Plaque Biofilm in Vivo

PubMed Central

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

Tumor Necrosis Factor-α Regulates Triggering Receptor Expressed on Myeloid Cells-1-dependent Matrix Metalloproteinases in the Carotid Plaques of Symptomatic Patients with Carotid Stenosis

PubMed Central

Rao, Velidi H.; Rai, Vikrant; Stoupa, Samantha; Subramanian, Saravanan; Agrawal, Devendra K

2016-01-01

Objective To determine the relationship between increased triggering receptor expressed on myeloid cells (TREM)-1 and plaque stability in atherosclerotic carotid stenosis. Methods The mRNA transcripts and protein for TREM-1, MMP-1, MMP-9, collagen type I (COL1A1) and collagen type III (COL3A1) were analyzed by qPCR and immunofluorescence in both tissues and VSMCs isolated from atherosclerotic carotid plaques of symptomatic and asymptomatic patients with carotid stenosis. Results The TREM-1, MMP-1 and MMP-9 mRNA transcripts were significantly increased (TREM-1, p<0.01; MMP-1, p<0.01 and MMP-9, p<0.001) while COL1A1 and COL3A1 mRNA transcripts were decreased (p<0.001) in VSMCs isolated from carotid plaques of symptomatic (S) than asymptomatic (AS) patients. Stimulation of cells with TNF-α further increased the mRNA transcripts of TREM-1, MMPs, COL1A1 and COL3A1. Modulation of TREM-1 by treatment with TREM-1 decoy receptor rTREM-1/Fc, and either TREM-1 antibodies or TREM-1 siRNA attenuated the TNF-α induced expression of MMP-1 and MMP-9 (p<0.01) and COL1A1 and COL3A1 (p<0.01) in S compared to AS VSMCs isolated from carotid plaques. Inhibition of NF-kB (BAY 11-7085), JNK (SP600125) and PI3K (LY294002) signaling pathways decreased the expression of TREM-1 (p<0.01), MMP-1 (p<0.001) and MMP-9 (p<0.01) in TNF-α treated VSMCs isolated from S carotid plaques compared to AS patients. Conclusion Increased expression of TREM-1 in S compared to AS patients involving MMP-1 and MMP-9 suggest a potential role of TREM-1 in plaque destabilization. Selective blockade of TREM-1 may contribute to the development of new therapies and promising targets for stabilizing vulnerable atherosclerotic plaques. PMID:27017522

Quantitative Evaluation of Atherosclerotic Plaque Using Ultrasound Tissue Characterization.

NASA Astrophysics Data System (ADS)

Yigiter, Ersin

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

Identifying vulnerable Asian Americans under Health Care Reform: working in small businesses and health care coverage.

PubMed

Cook, Won Kim; Tseng, Winston; Ko Chin, Kathy; John, Iyanrick; Chung, Corina

2014-11-01

Working in small businesses has been identified as a key factor for low coverage rates in immigrant communities. In this study, we identify specific cultural and socioeconomic predictors of Asian Americans who work in small businesses to identify subgroups at a greater disadvantage than others in obtaining health insurance. Logistic regression models were fitted using a sample of 3,819 Asian American small business owners and employers extracted from pooled 2005–2012 California Health Interview Survey data. We found that individuals with low income levels, Korean Americans, U.S.-born South Asian and Southeast Asian (other than Vietnamese) Americans, immigrants without citizenship (particularly those lacking a green card), and individuals with limited English proficiency had higher odds of lacking coverage. The odds of being uninsured did not differ between small business owners and employees. Based upon these key findings, we propose several strategies to expand coverage for Asian Americans working in small businesses and their most vulnerable subgroups.

The influence of composition and location on the toughness of human atherosclerotic femoral plaque tissue.

PubMed

Cunnane, E M; Barrett, H E; Kavanagh, E G; Mongrain, R; Walsh, M T

2016-02-01

sections. Regression analysis highlights the potential of employing the calcified tissue content of the plaque as a preoperative tool for predicting the fracture response of a target lesion to CBA (R(2)=0.885, p<0.001). This study addresses a gap in current knowledge regarding the influence of plaque location, composition and morphology on the toughness of human femoral plaque tissue. Such information is of great importance to the continued improvement of endovascular treatments, particularly cutting balloon angioplasty (CBA), which require experimentally derived data as a framework for assessing clinical cases and advancing medical devices. This study identifies that femoral plaque tissue exhibits large inter and intra patient and location variance regarding tissue toughness. Increasing calcified plaque content is demonstrated to correlate significantly with increasing toughness. This highlights the potential for predicting target lesion toughness which may lead to an increased adoption of the CBA technique and also further the uptake of endovascular treatment. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Correlation between detection rates of periodontopathic bacterial DNA in coronary stenotic artery plaque [corrected] and in dental plaque samples.

PubMed

Ishihara, Kazuyuki; Nabuchi, Akihiro; Ito, Rieko; Miyachi, Kouji; Kuramitsu, Howard K; Okuda, Katsuji

2004-03-01

Utilizing PCR, the 16S rRNA detection rates for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Treponema denticola, and Campylobacter rectus in samples of stenotic coronary artery plaques were determined to be 21.6, 23.3, 5.9, 23.5, and 15.7%, respectively. The detection rates for P. gingivalis and C. rectus correlated with their presence in subgingival plaque.

Finger's amniotic membrane buffer technique: protecting the cornea during radiation plaque therapy.

PubMed

Finger, Paul T

2008-04-01

To use amniotic membranes as a buffer between the cornea and radioactive eye plaques. Six melanomas were treated with ophthalmic plaque radiation therapy. Plaque-tumor localization required that a portion of the gold plaque touch the cornea during treatment. To enhance patient comfort and protect the cornea, an (0.1-mm-thick) amniotic membrane was interposed between the metal plaque edge and the cornea. Minimal ocular discomfort was noted during plaque radiation therapy. On a scale of 1 (none) to 10 (severe), all 6 patients reported pain levels of 1. As a tissue equivalent and because the mean thickness was only 0.1 mm, amniotic membranes had no significant effect on radiation dose calculations. No adverse effects, infections, or abrasions were noted. The amniotic membrane buffer technique improves patient comfort and protects the cornea during ophthalmic plaque radiation therapy.

Apollo Soyuz Test Project Commemorative plaque in orbit

NASA Image and Video Library

1975-07-17

AST-05-263 (17-18 July 1975) --- The Apollo-Soyuz Test Project (ASTP) Commemorative Plaque is assembled in the Soviet Soyuz Orbital Module during the joint U.S.-USSR Apollo-Soyuz Test Project docking mission in Earth orbit. The plaque is written both in English and Russian.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Characterizing the appearance and growth of amyloid plaques in APP/PS1 mice

PubMed Central

Yan, Ping; Bero, Adam W.; Cirrito, John R.; Xiao, Qingli; Hu, Xiaoyan; Wang, Yan; Gonzales, Ernesto; Holtzman, David M.; Lee, Jin-Moo

2009-01-01

Amyloid plaques are primarily composed of extracellular aggregates of amyloid-beta (Aβ) peptide and are a pathological signature of Alzheimer's disease (AD). However, the factors that influence the dynamics of amyloid plaque formation and growth in vivo are largely unknown. Using serial intravital multiphoton microscopy through a thinned-skull cranial window in APP/PS1 transgenic mice, we have found that amyloid plaques appear and grow over a period of weeks before reaching a mature size. Growth was more prominent early after initial plaque formation: plaques grew faster in 6 month-old compared to 10 month-old mice. Plaque growth rate was also size-related, as smaller plaques exhibited more rapid growth relative to larger plaques. Alterations in interstitial Aβ concentrations were associated with changes in plaque growth. Parallel studies using multiphoton microscopy and in vivo microdialysis revealed that pharmacological reduction of soluble extracellular Aβ by as little as 20-25% was associated with a dramatic decrease in plaque formation and growth. Furthermore, this small reduction in Aβ synthesis was sufficient to reduce amyloid plaque load in 6 month-old but not 10 month-old mice, suggesting that treatment early in disease pathogenesis may be more effective than later treatment. In contrast to thinned-skull windows, no significant plaque growth was observed under open-skull windows, which demonstrated extensive microglial and astrocytic activation. Together, these findings indicate that individual amyloid plaque growth in vivo occurs over a period of weeks and may be influenced by interstitial Aβ concentration as well as reactive gliosis. PMID:19710322

Role of infrasound pressure waves in atherosclerotic plaque rupture: a theoretical approach.

PubMed

Tsatsaris, Athanasios; Koukounaris, Efstathios; Motsakos, Theodoros; Perrea, Despina

2007-01-01

To investigate the role of infrasound aortic pressure waves (IPW) in atherosclerotic plaque rupture. Atherosclerotic plaques have been simulated partly, in two dimensions, as being short or long Conical Intersections (CIS), that is to say elliptic, parabolic or hyperbolic surfaces. Consequently, the course and reflection of the generated aortic pressure wave (infrasound domain-less than 20Hz) has been examined around the simulated plaques. The incidence of IPW on plaque surface results both in reflection and "refraction" of the wave. The IPW course within tissue, seems to be enhanced by high Cu-level presence at these areas according to recent evidence (US2003000388213). The "refracted", derived wave travels through plaque tissue and is eventually accumulated to the foci of the respective CIS-plaque geometry. The foci location within or underneath atheroma declares zones where infrasound energy is mostly absorbed. This process, among other mechanisms may contribute to plaque rupture through the development of local hemorrhage and inflammation in foci areas. In future, detection of foci areas and repair (i.e. via Laser Healing Microtechnique) may attenuate atherosclerotic plaque rupture behavior.

Detection and characterization of early plaque formations by Raman probe spectroscopy and optical coherence tomography: an in vivo study on a rabbit model

NASA Astrophysics Data System (ADS)

Matthäus, Christian; Dochow, Sebastian; Egodage, Kokila D.; Romeike, Bernd F.; Brehm, Bernhard R.; Popp, Jürgen

2018-01-01

Intravascular imaging techniques provide detailed specification about plaque appearance and morphology, but cannot deliver information about the biochemical composition of atherosclerotic plaques. As the biochemical composition is related to the plaque type, important aspects such as the risk of a plaque rupture and treatment are still difficult to assess. Currently, various spectroscopic techniques are tested for potential applications for the chemical analysis of plaque depositions. Here, we employ Raman spectroscopy in combination with optical coherence tomography (OCT) for the characterization of plaques on rabbits in vivo. Experiments were carried out on New Zealand white rabbits treated with a fat- and cholesterol-enriched diet, using a Raman probe setup with a 785-nm multimode laser as an excitation source. Subsequently, OCT images were acquired with a swept source at 1305±55 nm at 22.6 mW. Raman spectra were recorded from normal regions and regions with early plaque formations. The probe positioning was monitored by x-ray angiography. The spectral information identified plaque depositions consisting of lipids, with triglycerides as the major component. Afterward, OCT images of the spectroscopically investigated areas were obtained. The spectral information correlates well with the observed intravascular morphology and is in good agreement with histology. Raman spectroscopy can provide detailed biochemical specification of atherosclerotic plaques.

How Researchers Define Vulnerable Populations in HIV/AIDS Clinical Trials

PubMed Central

Lo, Bernard; Strauss, Ronald P.; Eron, Joseph; Gifford, Allen L.

2010-01-01

In this study, we interviewed researchers, asking them to define vulnerable populations in HIV/AIDS clinical trials, and provide feedback on the federal regulations for three vulnerable populations. Interview data informed a conceptual framework, and were content analyzed to identify acceptability or disagreement with the regulations. Beginning with several characteristics of vulnerable enrollees identified by researchers, the conceptual framework illustrates possible scenarios of how enrollees could be considered vulnerable in clinical research. Content analysis identified barriers affecting HIV/AIDS researchers’ ability to conduct clinical trials with pregnant women, prisoners, and children, for which the regulations specify additional protections. This study challenges current thinking about federal regulations’ group-based approach to defining vulnerable populations. PMID:20721614

Efficacy of 3 toothbrush treatments on plaque removal in orthodontic patients assessed with digital plaque imaging: a randomized controlled trial.

PubMed

Erbe, Christina; Klukowska, Malgorzata; Tsaknaki, Iris; Timm, Hans; Grender, Julie; Wehrbein, Heinrich

2013-06-01

Good oral hygiene is a challenge for orthodontic patients because food readily becomes trapped around the brackets and under the archwires, and appliances are an obstruction to mechanical brushing. The purpose of this study was to compare plaque removal efficacy of 3 toothbrush treatments in orthodontic subjects. This was a replicate-use, single-brushing, 3-treatment, examiner-blind, randomized, 6-period crossover study with washout periods of approximately 24 hours between visits. Forty-six adolescent and young adult patients with fixed orthodontics from a university clinic in Germany were randomized, based on computer-generated randomization, to 1 of 3 treatments: (1) oscillating-rotating electric toothbrush with a specially designed orthodontic brush head (Oral-B Triumph, OD17; Procter & Gamble, Cincinnati, Ohio); (2) the same electric toothbrush handle with a regular brush head (EB25; Procter & Gamble); and (3) a regular manual toothbrush (American Dental Association, Chicago, Ill). The primary outcome was the plaque score change from baseline, which we determined using digital plaque image analysis. Forty-five subjects completed the study. The differences in mean plaque removal (95% confidence interval) between the electric toothbrush with an orthodontic brush head (6% [4.4%-7.6%]) or a regular brush head (3.8% [2.2%-5.3%]) and the manual toothbrush were significant (P <0.001). Plaque removal with the electric toothbrush with the orthodontic brush head was superior (2.2%; P = 0.007) to the regular brush head. No adverse events were seen. The electric toothbrush, with either brush head, demonstrated significantly greater plaque removal over the manual brush. The orthodontic brush head was superior to the regular head. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Non-pulsed electrochemical impregnation of flexible metallic battery plaques

DOEpatents

Maskalick, Nicholas J.

1982-01-01

A method of loading active battery material into porous, flexible, metallic battery plaques, comprises the following steps: precipitating nickel hydroxide active material within the plaque, by making the plaque cathodic, at a high current density, in an electro-precipitation cell also containing a consumable nickel anode and a solution comprising nickel nitrate, having a pH of between 2.0 and 2.8; electrochemically oxidizing the precipitate in caustic formation solution; and repeating the electro-precipitation step at a low current density.

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

PubMed

Vouros, J; Sakellari, D; Konstantinidis, A

1994-11-01

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

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

PubMed

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.

Quantification of the uncertainty in coronary CTA plaque measurements using dynamic cardiac phantom and 3D-printed plaque models

NASA Astrophysics Data System (ADS)

Richards, Taylor; Sturgeon, Gregory M.; Ramirez-Giraldo, Juan Carlos; Rubin, Geoffrey; Segars, Paul; Samei, Ehsan

2017-03-01

The purpose of this study was to quantify the accuracy of coronary computed tomography angiography (CTA) stenosis measurements using newly developed physical coronary plaque models attached to a base dynamic cardiac phantom (Shelley Medical DHP-01). Coronary plaque models (5 mm diameter, 50% stenosis, and 32 mm long) were designed and 3D-printed with tissue equivalent materials (calcified plaque with iodine enhanced lumen). Realistic cardiac motion was achieved by fitting known cardiac motion vectors to left ventricle volume-time curves to create synchronized heart motion profiles executed by the base cardiac phantom. Realistic coronary CTA acquisition was accomplished by synthesizing corresponding ECG waveforms for gating and reconstruction purposes. All scans were acquired using a retrospective gating technique on a dual-source CT system (Siemens SOMATOM FLASH) with 75ms temporal resolution. Multi-planar reformatted images were reconstructed along vessel centerlines and the enhanced lumens were manually segmented by 5 independent operators. On average, the stenosis measurement accuracy was 0.9% positive bias for the motion free condition (0 bpm). The measurement accuracy monotonically decreased to 18.5% negative bias at 90 bpm. Contrast-tonoise (CNR), vessel circularity, and segmentation conformity also decreased monotonically with increasing heart rate. These results demonstrate successful implementation of the base cardiac phantom with 3D-printed coronary plaque models, adjustable motion profiles, and coordinated ECG waveforms. They further show the utility of the model to ascertain metrics of coronary CT accuracy and image quality under a variety of plaque, motion, and acquisition conditions.

Spatial-temporal analysis of dengue deaths: identifying social vulnerabilities.

PubMed

Silva, Maria do Socorro da; Branco, Maria Dos Remédios Freitas Carvalho; Aquino, José; Queiroz, Rejane Christine de Sousa; Bani, Emanuele; Moreira, Emnielle Pinto Borges; Medeiros, Maria Nilza Lima; Rodrigues, Zulimar Márita Ribeiro

2017-01-01

Currently, dengue fever, chikungunya fever, and zika virus represent serious public health issues in Brazil, despite efforts to control the vector, the Aedes aegypti mosquito. This was a descriptive and ecological study of dengue deaths occurring from 2002 to 2013 in São Luis, Maranhão, Brazil. Geoprocessing software was used to draw maps, linking the geo-referenced deaths with urban/social data at census tract level. There were 74 deaths, concentrated in areas of social vulnerability. The use of geo-technology tools pointed to a concentration of dengue deaths in specific intra-urban areas.

The use of plaque score measurements to assess changes in atherosclerotic plaque burden induced by lipid-lowering therapy over time: the METEOR study.

PubMed

Peters, Sanne A E; Dogan, Soner; Meijer, Rudy; Palmer, Mike K; Grobbee, Diederick E; Crouse, John R; O'Leary, Daniel H; Evans, Gregory W; Raichlen, Joel S; Bots, Michiel L

2011-01-01

To evaluate whether plaque scoring measurements are able to track changes in atherosclerotic plaque burden over time and to study whether this is affected by lipid-lowering therapy. Data used were from METEOR (Measuring Effects on Intima-Media Thickness: an Evaluation Of Rosuvastatin), a randomized controlled trial of rosuvastatin 40 mg among 984 low-risk patients with modest carotid intima-media thickening (CIMT). In this analysis, duplicate ultrasound images from 12 carotid sites were collected at the baseline and end of the study from 495 European patients and were evaluated for plaque presence and severity. Plaques were scored from near and far walls of the 12 sites (0= none; 1= minimal; 2= moderate; 3= severe) and plaque scores (PS) were combined into two summary measures for each examination. The MeanMaxPS is the mean over the 12 carotid sites of the maximum score at each site and the MaxMaxPS reflects the most severe lesion at any site. Baseline MeanMaxPS and MaxMaxPS were 0.31 (SD: 0.20) and 1.15 (SD: 0.51), respectively. Changes in MeanMaxPS and MaxMaxPS significantly differed between rosuvastatin and placebo (mean difference: -0.03 [SE: 0.01; p =0.016] and -0.09 [SE: 0.04; p =0.027], respectively). In contrast to rosuvastatin, which demonstrated no change from the baseline, placebo showed significant progression in MeanMaxPS and MaxMaxPS (p =0.002; both). The plaque-scoring method proved capable of assessing the change in atherosclerotic plaque burden over time and proved useful to evaluate lipid-lowering in asymptomatic individuals with a low risk of cardiovascular disease and subclinical atherosclerosis.

The etemic model of Gypsy Roma Traveller community vulnerability: is it time to rethink our understanding of vulnerability?

PubMed

Heaslip, Vanessa; Hean, Sarah; Parker, Jonathan

2016-08-09

To present a new etemic model of vulnerability. Despite vulnerability being identified as a core consequence of health and health experiences, there has been little research exploring the meaning of vulnerability as a concept. Yet, being vulnerable is known to have dire physical/mental health consequences. It is therefore a fundamental issue for nurses to address. To date, the meaning of the term vulnerability has been influenced by the work of Spiers (Journal of Advanced Nursing, 31, 2000, 715, The Essential Concepts of Nursing: Building Blocks for Practice, 2005, Elsevier, London). Spiers identified two aspects of vulnerability: the etic (external judgment of another persons' vulnerability) and the emic (internal lived experience of vulnerability). This approach has led to a plethora of research which has explored the etic (external judgment) of vulnerability and rendered the internal lived (or emic) experience invisible. Consequences of this, for marginalised communities such as Gypsy Roma Travellers include a lack of culturally sensitive services compounding health inequalities. Position paper. Drawing upon a qualitative phenomenological research study exploring the lived experience of vulnerability from a Gypsy Roma Travelling community (published previously), this paper presents a new model of vulnerability. This etemic model of vulnerability values both external and internal dimensions of vulnerability and argues for a fusion of these two opposing perspectives. If nurses and other health- and social care professionals wish to develop practice that is successful in engaging with Gypsy Roma Travellers, then there is a need to both understand and respect their community. This can be achieved through an etemic approach to understanding their vulnerability achieved by eliciting lived experience alongside the appreciation of epidemiological studies. If nurses and health practitioners used this etemic approach to practice then it would enable both the development

Magnetic Resonance Imaging-Based Assessment of Carotid Atheroma: a Comparative Study of Patients with and without Coronary Artery Disease.

PubMed

Usman, Ammara; Sadat, Umar; Teng, Zhongzhao; Graves, Martin J; Boyle, Jonathan R; Varty, Kevin; Hayes, Paul D; Gillard, Jonathan H

2017-02-01

Functional magnetic resonance (MR) imaging of atheroma using contrast media enables assessment of the systemic severity of atherosclerosis in different arterial beds. Whether black-blood imaging has similar ability remains widely unexplored. In this study, we evaluate whether black-blood imaging can differentiate carotid plaques of patients with and without coronary artery disease (CAD) in terms of morphological and biomechanical features of plaque vulnerability, thereby allowing assessment of the systemic severity nature of atherosclerosis in different arterial beds. Forty-one patients with CAD and 59 patients without CAD underwent carotid black-blood MR imaging. Plaque components were segmented to identify large lipid core (LC), ruptured fibrous cap (FC), and plaque hemorrhage (PH). These segmented contours of plaque components were used to quantify maximum structural biomechanical stress. Patients with CAD and without CAD had comparable demographics and comorbidities. Both groups had comparable prevalence of morphological features of plaque vulnerability (FC rupture, 44% versus 41%, P = .90; PH, 58% versus 47%, P = .78; large LC, 32% versus 47%, P = .17), respectively. The maximum biomechanical stress was not significantly different for both groups (241versus 278 kPa, P = .14) respectively. Black-blood imaging does not appear to have the ability to differentiate between the morphological and biomechanical features of plaque vulnerability when comparing patients with and without symptomatic atherosclerotic disease in a distant arterial territory such as coronary artery. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

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

PubMed

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.

Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation

PubMed Central

Amoush, Ahmad; Wilkinson, Douglas A.

2015-01-01

This work is a comparative study of the dosimetry calculated by Plaque Simulator, a treatment planning system for eye plaque brachytherapy, to the dosimetry calculated using Monte Carlo simulation for an Eye Physics model EP917 eye plaque. Monte Carlo (MC) simulation using MCNPX 2.7 was used to calculate the central axis dose in water for an EP917 eye plaque fully loaded with 17 IsoAid Advantage  125I seeds. In addition, the dosimetry parameters Λ, gL(r), and F(r,θ) were calculated for the IsoAid Advantage model IAI‐125  125I seed and benchmarked against published data. Bebig Plaque Simulator (PS) v5.74 was used to calculate the central axis dose based on the AAPM Updated Task Group 43 (TG‐43U1) dose formalism. The calculated central axis dose from MC and PS was then compared. When the MC dosimetry parameters for the IsoAid Advantage  125I seed were compared with the consensus values, Λ agreed with the consensus value to within 2.3%. However, much larger differences were found between MC calculated gL(r) and F(r,θ) and the consensus values. The differences between MC‐calculated dosimetry parameters are much smaller when compared with recently published data. The differences between the calculated central axis absolute dose from MC and PS ranged from 5% to 10% for distances between 1 and 12 mm from the outer scleral surface. When the dosimetry parameters for the  125I seed from this study were used in PS, the calculated absolute central axis dose differences were reduced by 2.3% from depths of 4 to 12 mm from the outer scleral surface. We conclude that PS adequately models the central dose profile of this plaque using its defaults for the IsoAid model IAI‐125 at distances of 1 to 7 mm from the outer scleral surface. However, improved dose accuracy can be obtained by using updated dosimetry parameters for the IsoAid model IAI‐125  125I seed. PACS number: 87.55.K‐ PMID:26699577

The Clinical Effectiveness of Post-Brushing Rinsing in Reducing Plaque and Gingivitis: A Systematic Review

PubMed Central

Patthi, Basavaraj; Singla, Ashish; Gupta, Ritu; Jankiram, Chandrasheker; Kumar, Jishnu Krishna; Vashishtha, Vaibhav; Malhi, Ravneet

2016-01-01

Introduction Dental plaque is the major etiological factor associated with the development of gingivitis. Hence, maintenance of oral hygiene is very essential. Aim To systematically review the literature on the effects of a post toothbrushing rinsing on plaque and parameters of gingival inflammation. Materials and Methods A literature review was performed in PubMed Central and Cochrane library, embase, google scholar were searched up to February 2015 to identify appropriate studies. The primary outcome measure was plaque and gingival inflammation reduction. Results Out of the total 56 titles appeared, 08articles fulfilled the criteria and were selected for the review. One article which was hand searched and one article which was through e-mail was included. A statistically significant reduction in overall plaque and gingivitis was noted when different mouth rinses were compared to the control (p<0.05). It was seen that chlorhexidine is the best antiplaque and antigingivitis agent but due to its side effects after continuous use, was not indicated for long term use. Probiotic was superior to chlorhexidine in terms of reduction of gingival inflammation. Conclusion There are relatively few studies evaluating the association between post toothbrushing rinsing and gingivitis. A clear effect was observed, indicating that different mouthrinses (chlorhexidine, probiotic, herbal, essential oil mouthrinse) when used as an adjunct to mechanical means of oral hygiene, provides an additional benefit with regard to plaque and gingivitis reduction as compared to a placebo or control. PMID:27437376

Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology.

PubMed

Bourantas, Christos V; Jaffer, Farouc A; Gijsen, Frank J; van Soest, Gijs; Madden, Sean P; Courtney, Brian K; Fard, Ali M; Tenekecioglu, Erhan; Zeng, Yaping; van der Steen, Antonius F W; Emelianov, Stanislav; Muller, James; Stone, Peter H; Marcu, Laura; Tearney, Guillermo J; Serruys, Patrick W

2017-02-07

Cumulative evidence from histology-based studies demonstrate that the currently available intravascular imaging techniques have fundamental limitations that do not allow complete and detailed evaluation of plaque morphology and pathobiology, limiting the ability to accurately identify high-risk plaques. To overcome these drawbacks, new efforts are developing for data fusion methodologies and the design of hybrid, dual-probe catheters to enable accurate assessment of plaque characteristics, and reliable identification of high-risk lesions. Today several dual-probe catheters have been introduced including combined near infrared spectroscopy-intravascular ultrasound (NIRS-IVUS), that is already commercially available, IVUS-optical coherence tomography (OCT), the OCT-NIRS, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, IVUS intravascular photoacoustic imaging and combined fluorescence lifetime-IVUS imaging. These multimodal approaches appear able to overcome limitations of standalone imaging and provide comprehensive visualization of plaque composition and plaque biology. The aim of this review article is to summarize the advances in hybrid intravascular imaging, discuss the technical challenges that should be addressed in order to have a use in the clinical arena, and present the evidence from their first applications aiming to highlight their potential value in the study of atherosclerosis. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

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

NASA Astrophysics Data System (ADS)

Lander, J. J.

1986-03-01

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