Sample records for accurate plaque vulnerability

  1. Diagnosis of vulnerable atherosclerotic plaques by time-resolved fluorescence spectroscopy and ultrasound imaging.

    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; Shung, K K; Sun, L; Marcu, L

    2006-01-01

    In this study, time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and ultrasonography were applied to detect vulnerable (high-risk) atherosclerotic plaque. A total of 813 TR-LIFS measurements were taken from carotid plaques of 65 patients, and subsequently analyzed using the Laguerre deconvolution technique. The investigated spots were classified by histopathology as thin, fibrotic, calcified, low-inflamed, inflamed and necrotic lesions. Spectral and time-resolved parameters (normalized intensity values and Laguerre expansion coefficients) were extracted from the TR-LIFS data. Feature selection for classification was performed by either analysis of variance (ANOVA) or principal component analysis (PCA). A stepwise linear discriminant analysis algorithm was developed for detecting inflamed and necrotic lesion, representing the most vulnerable plaques. These vulnerable plaques were detected with high sensitivity (>80%) and specificity (>90%). Ultrasound (US) imaging was obtained in 4 carotid plaques in addition to TR-LIFS examination. Preliminary results indicate that US provides important structural information of the plaques that could be combined with the compositional information obtained by TR-LIFS, to obtain a more accurate diagnosis of vulnerable atherosclerotic plaque.

  2. The Lipid-Rich Plaque Study of vulnerable plaques and vulnerable patients: Study design and rationale.

    PubMed

    Waksman, Ron; Torguson, Rebecca; Spad, Mia-Ashley; Garcia-Garcia, Hector; Ware, James; Wang, Rui; Madden, Sean; Shah, Priti; Muller, James

    2017-10-01

    It has been hypothesized that the outcome post-PCI could be improved by the detection and subsequent treatment of vulnerable patients and lipid-rich vulnerable coronary plaques (LRP). A near-infrared spectroscopy (NIRS) catheter capable of detecting LRP is being evaluated in The Lipid-Rich Plaque Study. The LRP Study is an international, multicenter, prospective cohort study conducted in patients with suspected coronary artery disease (CAD) who underwent cardiac catheterization with possible ad hoc PCI for an index event. Patient level and plaque level events were detected by follow-up in the subsequent 2 years. Enrollment began in February 2014 and was completed in March 2016; a total of 1,562 patients were enrolled. Adjudication of new coronary event occurrence and de novo culprit lesion location during the 2-year follow-up is performed by an independent clinical end-points committee (CEC) blinded to NIRS-IVUS findings. The first analysis of the results will be performed when at least 20 de novo events have occurred for which follow-up angiographic data and baseline NIRS-IVUS measurements are available. It is expected that results of the study will be announced in 2018. The LRP Study will test the hypotheses that NIRS-IVUS imaging to detect LRP in patients can identify vulnerable patients and vulnerable plaques. Identification of vulnerable patients will assist future studies of novel systemic therapies; identification of localized vulnerable plaques would enhance future studies of possible preventive measures. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Integrated intravascular ultrasound and optical coherence tomography technology: a promising tool to identify vulnerable plaques [INVITED PAPER

    PubMed Central

    Li, Jiawen; Chen, Zhongping

    2017-01-01

    Heart attack is mainly caused by the rupture of a vulnerable plaque. IVUS-OCT is a novel medical imaging modality that provides opportunities for accurate assessment of vulnerable plaques in vivo in patients. IVUS provides deep penetration to image the whole necrotic core while OCT enables accurate measurement of the fibrous cap of a plaque owing to its high resolution. In this paper, the authors describe the fundamentals, the technical designs and the applications of IVUS-OCT technology. Results from cadaver specimens are summarized, which indicated the complementary nature of OCT and IVUS for assessment of vulnerable plaques, plaque composition, and stent-tissue interactions. Furthermore, previously reported in vivo animal experiments are reviewed to assess the clinical adaptability of IVUS-OCT. Future directions for this technology are also discussed in this review. PMID:28966987

  4. IVUS-Based Computational Modeling and Planar Biaxial Artery Material Properties for Human Coronary Plaque Vulnerability Assessment

    PubMed Central

    Liu, Haofei; Cai, Mingchao; Yang, Chun; Zheng, Jie; Bach, Richard; Kural, Mehmet H.; Billiar, Kristen L.; Muccigrosso, David; Lu, Dongsi; Tang, Dalin

    2012-01-01

    Image-based computational modeling has been introduced for vulnerable atherosclerotic plaques to identify critical mechanical conditions which may be used for better plaque assessment and rupture predictions. In vivo patient-specific coronary plaque models are lagging due to limitations on non-invasive image resolution, flow data, and vessel material properties. A framework is proposed to combine intravascular ultrasound (IVUS) imaging, biaxial mechanical testing and computational modeling with fluid-structure interactions and anisotropic material properties to acquire better and more complete plaque data and make more accurate plaque vulnerability assessment and predictions. Impact of pre-shrink-stretch process, vessel curvature and high blood pressure on stress, strain, flow velocity and flow maximum principal shear stress was investigated. PMID:22428362

  5. In vivo Raman spectral pathology of human atherosclerosis and vulnerable plaque

    NASA Astrophysics Data System (ADS)

    Motz, Jason T.; Fitzmaurice, Maryann; Miller, Arnold; Gandhi, Saumil J.; Haka, Abigail S.; Galindo, Luis; Dasari, Ramachandra R.; Kramer, John R., Jr.; Feld, Michael S.

    2006-03-01

    The rupture of vulnerable atherosclerotic plaque accounts for the majority of clinically significant acute cardiovascular events. Because stability of these culprit lesions is directly related to chemical and morphological composition, Raman spectroscopy may be a useful technique for their study. Recent developments in optical fiber probe technology have allowed for the real-time in vivo Raman spectroscopic characterization of human atherosclerotic plaque demonstrated in this work. We spectroscopically examine 74 sites during carotid endarterectomy and femoral artery bypass surgeries. Of these, 34 are surgically biopsied and examined histologically. Excellent signal-to-noise ratio spectra are obtained in only 1 s and fit with an established model, demonstrating accurate tissue characterization. We also report the first evidence that Raman spectroscopy has the potential to identify vulnerable plaque, achieving a sensitivity and specificity of 79 and 85%, respectively. These initial findings indicate that Raman spectroscopy has the potential to be a clinically relevant diagnostic tool for studying cardiovascular disease.

  6. Non-invasive detection of vulnerable coronary plaque

    PubMed Central

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

    2011-01-01

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

  7. Emerging Technology Update Intravascular Photoacoustic Imaging of Vulnerable Atherosclerotic Plaque.

    PubMed

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

    2016-10-01

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

  8. Imaging of coronary atherosclerosis and identification of the vulnerable plaque

    PubMed Central

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

    2003-01-01

    Identification of the vulnerable plaque responsible for the occurrence of acute coronary syndromes and acute coronary death is a prerequisite for the stabilisation of this vulnerable plaque. Comprehensive coronary atherosclerosis imaging in clinical practice should involve visualisation of the entire coronary artery tree and characterisation of the plaque, including the three-dimensional morphology of the plaque, encroachment of the plaque on the vessel lumen, the major tissue components of the plaque, remodelling of the vessel and presence of inflammation. Obviously, no single diagnostic modality is available that provides such comprehensive imaging and unfortunately no diagnostic tool is available that unequivocally identifies the vulnerable plaque. The objective of this article is to discuss experience with currently available diagnostic modalities for coronary atherosclerosis imaging. In addition, a number of evolving techniques will be briefly discussed. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7 PMID:25696244

  9. The vulnerable plaque: the real villain in acute coronary syndromes.

    PubMed

    Liang, Michael; Puri, Aniket; Devlin, Gerard

    2011-01-01

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

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

    PubMed

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

    2014-06-01

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

  11. Molecular Imaging of Vulnerable Atherosclerotic Plaques in Animal Models

    PubMed Central

    Gargiulo, Sara; Gramanzini, Matteo; Mancini, Marcello

    2016-01-01

    Atherosclerosis is characterized by intimal plaques of the arterial vessels that develop slowly and, in some cases, may undergo spontaneous rupture with subsequent heart attack or stroke. Currently, noninvasive diagnostic tools are inadequate to screen atherosclerotic lesions at high risk of acute complications. Therefore, the attention of the scientific community has been focused on the use of molecular imaging for identifying vulnerable plaques. Genetically engineered murine models such as ApoE−/− and ApoE−/−Fbn1C1039G+/− mice have been shown to be useful for testing new probes targeting biomarkers of relevant molecular processes for the characterization of vulnerable plaques, such as vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, intercellular adhesion molecule (ICAM)-1, P-selectin, and integrins, and for the potential development of translational tools to identify high-risk patients who could benefit from early therapeutic interventions. This review summarizes the main animal models of vulnerable plaques, with an emphasis on genetically altered mice, and the state-of-the-art preclinical molecular imaging strategies. PMID:27618031

  12. Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque

    PubMed Central

    Picano, Eugenio; Paterni, Marco

    2015-01-01

    A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque), iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque), and markedly hyperechoic with shadowing (calcific plaque). Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics) are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging, offering unique

  13. Intravascular probe for detection of vulnerable plaque

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2013-12-01

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

  16. 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.

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

    PubMed Central

    2013-01-01

    Background Carotid plaque echolucency as detected by Color Doppler ultrasonography (CDUS) has been used as a potential marker of plaque vulnerability. However, contrast-enhanced ultrasound (CEUS) has recently been shown to be a valuable method to evaluate the vulnerability and neovascularization within carotid atherosclerotic plaques. The aim of this study was to compare CEUS and CDUS in the assessment of plaque vulnerability using transcranial color Doppler (TCD) monitoring of microembolic signals (MES) as a reference technique. Methods A total of 46 subjects with arterial stenosis (≥ 50%) underwent a carotid duplex ultrasound, TCD monitoring of MES and CEUS (SonoVue doses of 2.0 mL) within a span of 3 days. The agreement between the CEUS, CDUS, and MES findings was assessed with a chi-square test. A p-value less than 0.05 was considered statistically significant. Results Neovascularization was observed in 30 lesions (44.4%). The vascular risk factors for stroke were similar and there were no age or gender differences between the 2 groups. Using CEUS, MES were identified in 2 patients (12.5%) within class 1 (non-neovascularization) as opposed to 15 patients (50.0%) within class 2 (neovascularization) (p = 0.023). CDUS revealed no significant differences in the appearance of the MES between the 2 groups (hyperechoic and hypoechoic) (p = 0.237). Conclusion This study provides preliminary evidence to suggest that intraplaque neovascularization detected by CEUS is associated with the presence of MESs, where as plaque echogenicity on traditional CDUS does not. These findings argue that CEUS may better identify high-risk plaques. PMID:23537052

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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/

  3. 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.

  4. MRI-based biomechanical parameters for carotid artery plaque vulnerability assessment.

    PubMed

    Speelman, Lambert; Teng, Zhongzhao; Nederveen, Aart J; van der Lugt, Aad; Gillard, Jonathan H

    2016-03-01

    Carotid atherosclerotic plaques are a major cause of ischaemic stroke. The biomechanical environment to which the arterial wall and plaque is subjected to plays an important role in the initiation, progression and rupture of carotid plaques. MRI is frequently used to characterize the morphology of a carotid plaque, but new developments in MRI enable more functional assessment of carotid plaques. In this review, MRI based biomechanical parameters are evaluated on their current status, clinical applicability, and future developments. Blood flow related biomechanical parameters, including endothelial wall shear stress and oscillatory shear index, have been shown to be related to plaque formation. Deriving these parameters directly from MRI flow measurements is feasible and has great potential for future carotid plaque development prediction. Blood pressure induced stresses in a plaque may exceed the tissue strength, potentially leading to plaque rupture. Multi-contrast MRI based stress calculations in combination with tissue strength assessment based on MRI inflammation imaging may provide a plaque stress-strength balance that can be used to assess the plaque rupture risk potential. Direct plaque strain analysis based on dynamic MRI is already able to identify local plaque displacement during the cardiac cycle. However, clinical evidence linking MRI strain to plaque vulnerability is still lacking. MRI based biomechanical parameters may lead to improved assessment of carotid plaque development and rupture risk. However, better MRI systems and faster sequences are required to improve the spatial and temporal resolution, as well as increase the image contrast and signal-to-noise ratio.

  5. Detection of Vulnerable Atherosclerotic Plaques in Experimental Atherosclerosis with the USPIO-Enhanced MRI.

    PubMed

    Qi, Chun-Mei; Du, Lili; Wu, Wei-Heng; Li, Dong-Ye; Hao, Ji; Gong, Lei; Deng, Liangrong; Zhang, Tao; Zhang, Chao; Zhang, Yu

    2015-11-01

    This study's goal was to assess the diagnostic value of the USPIO-(ultra-small superparamagnetic iron oxide) enhanced magnetic resonance imaging (MRI) in detection of vulnerable atherosclerotic plaques in abdominal aorta in experimental atherosclerosis. Thirty New Zealand rabbits were randomly divided into two groups, Group A and Group B. Each group comprised 15 animals which were fed with high cholesterol diet for 8 weeks and then subjected to balloon-induced endothelial injury of the abdominal aorta. After another 8 weeks, animals in Group B received adenovirus carrying p53 gene that was injected through a catheter into the aortic segments rich in plaques. Two weeks later, all rabbits were challenged with the injection of Chinese Russell's viper venom and histamine. Pre-contrast images and USPIO-enhanced MRI images were obtained after pharmacological triggering with injection of USPIO for 5 days. Blood specimens were taken for biochemical and serological tests at 0 and 18 weeks. Abdominal aorta was histologically studied. The levels of serum ICAM-1 and VCAM-1 were quantified by ELISA. Vulnerable plaques appeared as a local hypo-intense signal on the USPIO-enhanced MRI, especially on T2*-weighted sequences. The signal strength of plaques reached the peak at 96 h. Lipid levels were significantly (p < 0.05) higher in both Group A and B compared with the levels before the high cholesterol diet. The ICAM-1 and VCAM-1 levels were significantly (p < 0.05) higher in Group B compared with Group A. The USPIO-enhanced MRI efficiently identifies vulnerable plaques due to accumulation of USPIO within macrophages in abdominal aorta plaques.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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.

  14. Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging

    NASA Astrophysics Data System (ADS)

    Doherty, Joshua Ryan

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

  15. 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

  16. 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

  17. 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

  18. [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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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

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

    PubMed Central

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

    2015-01-01

    Background Rupture of an atherosclerotic plaque is the primary cause of acute cardiovascular and cerebrovascular syndromes. Early and non-invasive detection of vulnerable atherosclerotic plaques (VP) would be significant in preventing some aspects of these syndromes. As a new contrast agent, dimercaptosuccinic acid (DMSA) modified ultra-small super paramagnetic iron oxide (USPIO) was synthesized and used to identify VP and rupture plaque by magnetic resonance imaging (MRI). Methods Atherosclerosis was induced in male New Zealand White rabbits by feeding a high cholesterol diet (n = 30). Group A with atherosclerosis plaque (n = 10) were controls. VP was established in groups B (n = 10) and C (n = 10) using balloon-induced endothelial injury of the abdominal aorta. Adenovirus-carrying p53 genes were injected into the aortic segments rich in plaques after 8 weeks. Group C was treated with atorvastatin for 8 weeks. Sixteen weeks later, all rabbits underwent pharmacological triggering, and imaging were taken daily for 5 d after DMSA-USPIO infusion. At the first day and before being killed, serum MMP-9, sCD40L, and other lipid indicators were measured. Results DMSA-USPIO particles accumulated in VP and rupture plaques. Rupture plaques appeared as areas of hyper-intensity on DMSA-USPIO enhanced MRI, especially T2*-weighted sequences, with a signal strength peaking at 96 h. The group given atorvastatin showed few DMSA-USPIO particles and had lower levels of serum indicators. MMP-9 and sCD40L levels in group B were significantly higher than in the other 2 groups (P <0.05). Conclusion After successfully establishing a VP model in rabbits, DMSA-USPIO was used to enhance MRI for clear identification of plaque inflammation and rupture. Rupture plaques were detectable in this way probably due to an activating inflammatory process. Atorvastatin reduced the inflammatory response and stabilizing VP possibly by decreasing MMP-9 and sCD40L levels. PMID:25973795

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. The standard centrifuge method accurately measures vulnerability curves of long-vesselled olive stems.

    PubMed

    Hacke, Uwe G; Venturas, Martin D; MacKinnon, Evan D; Jacobsen, Anna L; Sperry, John S; Pratt, R Brandon

    2015-01-01

    The standard centrifuge method has been frequently used to measure vulnerability to xylem cavitation. This method has recently been questioned. It was hypothesized that open vessels lead to exponential vulnerability curves, which were thought to be indicative of measurement artifact. We tested this hypothesis in stems of olive (Olea europea) because its long vessels were recently claimed to produce a centrifuge artifact. We evaluated three predictions that followed from the open vessel artifact hypothesis: shorter stems, with more open vessels, would be more vulnerable than longer stems; standard centrifuge-based curves would be more vulnerable than dehydration-based curves; and open vessels would cause an exponential shape of centrifuge-based curves. Experimental evidence did not support these predictions. Centrifuge curves did not vary when the proportion of open vessels was altered. Centrifuge and dehydration curves were similar. At highly negative xylem pressure, centrifuge-based curves slightly overestimated vulnerability compared to the dehydration curve. This divergence was eliminated by centrifuging each stem only once. The standard centrifuge method produced accurate curves of samples containing open vessels, supporting the validity of this technique and confirming its utility in understanding plant hydraulics. Seven recommendations for avoiding artefacts and standardizing vulnerability curve methodology are provided. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. Xylem vulnerability to cavitation can be accurately characterised in species with long vessels using a centrifuge method.

    PubMed

    Tobin, M F; Pratt, R B; Jacobsen, A L; De Guzman, M E

    2013-05-01

    Vulnerability to cavitation curves describe the decrease in xylem hydraulic conductivity as xylem pressure declines. Several techniques for constructing vulnerability curves use centrifugal force to induce negative xylem pressure in stem or root segments. Centrifuge vulnerability curves constructed for long-vesselled species have been hypothesised to overestimate xylem vulnerability to cavitation due to increased vulnerability of vessels cut open at stem ends that extend to the middle or entirely through segments. We tested two key predictions of this hypothesis: (i) centrifugation induces greater embolism than dehydration in long-vesselled species, and (ii) the proportion of open vessels changes centrifuge vulnerability curves. Centrifuge and dehydration vulnerability curves were compared for a long- and short-vesselled species. The effect of open vessels was tested in four species by comparing centrifuge vulnerability curves for stems of two lengths. Centrifuge and dehydration vulnerability curves agreed well for the long- and short-vesselled species. Centrifuge vulnerability curves constructed using two stem lengths were similar. Also, the distribution of embolism along the length of centrifuged stems matched the theoretical pressure profile induced by centrifugation. We conclude that vulnerability to cavitation can be accurately characterised with vulnerability curves constructed using a centrifuge technique, even in long-vesselled species. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. Computer-implemented system and method for automated and highly accurate plaque analysis, reporting, and visualization

    NASA Technical Reports Server (NTRS)

    Kemp, James Herbert (Inventor); Talukder, Ashit (Inventor); Lambert, James (Inventor); Lam, Raymond (Inventor)

    2008-01-01

    A computer-implemented system and method of intra-oral analysis for measuring plaque removal is disclosed. The system includes hardware for real-time image acquisition and software to store the acquired images on a patient-by-patient basis. The system implements algorithms to segment teeth of interest from surrounding gum, and uses a real-time image-based morphing procedure to automatically overlay a grid onto each segmented tooth. Pattern recognition methods are used to classify plaque from surrounding gum and enamel, while ignoring glare effects due to the reflection of camera light and ambient light from enamel regions. The system integrates these components into a single software suite with an easy-to-use graphical user interface (GUI) that allows users to do an end-to-end run of a patient record, including tooth segmentation of all teeth, grid morphing of each segmented tooth, and plaque classification of each tooth image.

  17. 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

  18. Evaluation of a novel immunochromatographic device for rapid and accurate clinical detection of Porphyromonas gingivalis in subgingival plaque.

    PubMed

    Imamura, K; Takayama, S; Saito, A; Inoue, E; Nakayama, Y; Ogata, Y; Shirakawa, S; Nagano, T; Gomi, K; Morozumi, T; Akiishi, K; Watanabe, K; Yoshie, H

    2015-10-01

    An important goal for the improved diagnosis and management of infectious and inflammatory diseases, such as periodontitis, is the development of rapid and accurate technologies for the decentralized detection of bacterial pathogens. The aim of this prospective multicenter study was to evaluate the clinical use of a novel immunochromatographic device with monoclonal antibodies for the rapid point-of-care detection and semi-quantification of Porphyromonas gingivalis in subgingival plaque. Sixty-three patients with chronic periodontitis and 28 periodontally healthy volunteers were subjected to clinical and microbiological examinations. Subgingival plaque samples were analyzed for the presence of P. gingivalis using a novel immunochromatography based device DK13-PG-001, designed to detect the 40k-outer membrane protein of P. gingivalis, and compared with a PCR-Invader method. In the periodontitis group, a significant strong positive correlation in detection results was found between the test device score and the PCR-Invader method (Spearman rank correlation, r=0.737, p<0.0001). The sensitivity, specificity, and positive and negative predictive values of the test device were 96.2%, 91.8%, 90.4% and 96.7%, respectively. The detection threshold of the test device was determined to be approximately 10(4) (per two paper points). There were significant differences in the bacterial counts by the PCR-Invader method among groups with different ranges of device scores. With a cut-off value of ≥0.25 in device score, none of periodontally healthy volunteers were tested positive for the subgingival presence of P. gingivalis, whereas 76% (n=48) of periodontitis subjects were tested positive. There was a significant positive correlation between device scores for P. gingivalis and periodontal parameters including probing pocket depth and clinical attachment level (r=0.317 and 0.281, respectively, p<0.01). The results suggested that the DK13-PG-001 device kit can be effectively used

  19. 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.

  20. 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.

  1. Validation of the Filovirus Plaque Assay for Use in Preclinical Studies

    PubMed Central

    Shurtleff, Amy C.; Bloomfield, Holly A.; Mort, Shannon; Orr, Steven A.; Audet, Brian; Whitaker, Thomas; Richards, Michelle J.; Bavari, Sina

    2016-01-01

    A plaque assay for quantitating filoviruses in virus stocks, prepared viral challenge inocula and samples from research animals has recently been fully characterized and standardized for use across multiple institutions performing Biosafety Level 4 (BSL-4) studies. After standardization studies were completed, Good Laboratory Practices (GLP)-compliant plaque assay method validation studies to demonstrate suitability for reliable and reproducible measurement of the Marburg Virus Angola (MARV) variant and Ebola Virus Kikwit (EBOV) variant commenced at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID). The validation parameters tested included accuracy, precision, linearity, robustness, stability of the virus stocks and system suitability. The MARV and EBOV assays were confirmed to be accurate to ±0.5 log10 PFU/mL. Repeatability precision, intermediate precision and reproducibility precision were sufficient to return viral titers with a coefficient of variation (%CV) of ≤30%, deemed acceptable variation for a cell-based bioassay. Intraclass correlation statistical techniques for the evaluation of the assay’s precision when the same plaques were quantitated by two analysts returned values passing the acceptance criteria, indicating high agreement between analysts. The assay was shown to be accurate and specific when run on Nonhuman Primates (NHP) serum and plasma samples diluted in plaque assay medium, with negligible matrix effects. Virus stocks demonstrated stability for freeze-thaw cycles typical of normal usage during assay retests. The results demonstrated that the EBOV and MARV plaque assays are accurate, precise and robust for filovirus titration in samples associated with the performance of GLP animal model studies. PMID:27110807

  2. 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.

  3. Optimal MR Plaque Imaging for Cervical Carotid Artery Stenosis in Predicting the Development of Microembolic Signals during Exposure of Carotid Arteries in Endarterectomy: Comparison of 4 T1-Weighted Imaging Techniques.

    PubMed

    Sato, Y; Ogasawara, K; Narumi, S; Sasaki, M; Saito, A; Tsushima, E; Namba, T; Kobayashi, M; Yoshida, K; Terayama, Y; Ogawa, A

    2016-06-01

    Preoperative identification of plaque vulnerability may allow improved risk stratification for patients considered for carotid endarterectomy. The present study aimed to determine which plaque imaging technique, cardiac-gated black-blood fast spin-echo, magnetization-prepared rapid acquisition of gradient echo, source image of 3D time-of-flight MR angiography, or noncardiac-gated spin-echo, most accurately predicts development of microembolic signals during exposure of carotid arteries in carotid endarterectomy. Eighty patients with ICA stenosis (≥70%) underwent the 4 sequences of preoperative MR plaque imaging of the affected carotid bifurcation and then carotid endarterectomy under transcranial Doppler monitoring of microembolic signals in the ipsilateral middle cerebral artery. The contrast ratio of the carotid plaque was calculated by dividing plaque signal intensity by sternocleidomastoid muscle signal intensity. Microembolic signals during exposure of carotid arteries were detected in 23 patients (29%), 3 of whom developed new neurologic deficits postoperatively. Those deficits remained at 24 hours after surgery in only 1 patient. The area under the receiver operating characteristic curve to discriminate between the presence and absence of microembolic signals during exposure of the carotid arteries was significantly greater with nongated spin-echo than with black-blood fast spin-echo (difference between areas, 0.258; P < .0001), MPRAGE (difference between areas, 0.106; P = .0023), or source image of 3D time-of-flight MR angiography (difference between areas, 0.128; P = .0010). Negative binomial regression showed that in the 23 patients with microembolic signals, the contrast ratio was associated with the number of microembolic signals only in nongated spin-echo (risk ratio, 1.36; 95% confidence interval, 1.01-1.97; P < .001). Nongated spin-echo may predict the development of microembolic signals during exposure of the carotid arteries in carotid

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Integrating metabolic performance, thermal tolerance, and plasticity enables for more accurate predictions on species vulnerability to acute and chronic effects of global warming.

    PubMed

    Magozzi, Sarah; Calosi, Piero

    2015-01-01

    Predicting species vulnerability to global warming requires a comprehensive, mechanistic understanding of sublethal and lethal thermal tolerances. To date, however, most studies investigating species physiological responses to increasing temperature have focused on the underlying physiological traits of either acute or chronic tolerance in isolation. Here we propose an integrative, synthetic approach including the investigation of multiple physiological traits (metabolic performance and thermal tolerance), and their plasticity, to provide more accurate and balanced predictions on species and assemblage vulnerability to both acute and chronic effects of global warming. We applied this approach to more accurately elucidate relative species vulnerability to warming within an assemblage of six caridean prawns occurring in the same geographic, hence macroclimatic, region, but living in different thermal habitats. Prawns were exposed to four incubation temperatures (10, 15, 20 and 25 °C) for 7 days, their metabolic rates and upper thermal limits were measured, and plasticity was calculated according to the concept of Reaction Norms, as well as Q10 for metabolism. Compared to species occupying narrower/more stable thermal niches, species inhabiting broader/more variable thermal environments (including the invasive Palaemon macrodactylus) are likely to be less vulnerable to extreme acute thermal events as a result of their higher upper thermal limits. Nevertheless, they may be at greater risk from chronic exposure to warming due to the greater metabolic costs they incur. Indeed, a trade-off between acute and chronic tolerance was apparent in the assemblage investigated. However, the invasive species P. macrodactylus represents an exception to this pattern, showing elevated thermal limits and plasticity of these limits, as well as a high metabolic control. In general, integrating multiple proxies for species physiological acute and chronic responses to increasing

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque

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

    Saba, Luca, E-mail: lucasaba@tiscali.i; Potters, Fons; Lugt, Aad van der

    2010-08-15

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

  17. [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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. In Vivo Visualization of Alzheimer’s Amyloid Plaques by MRI in Transgenic Mice Without a Contrast Agent

    PubMed Central

    Jack, Clifford R.; Garwood, Michael; Wengenack, Thomas M.; Borowski, Bret; Curran, Geoffrey L.; Lin, Joseph; Adriany, Gregor; Grohn, Olli H.J.; Grimm, Roger; Poduslo, Joseph F.

    2009-01-01

    One of the cardinal pathologic features of Alzheimer’s disease (AD) is formation of senile, or amyloid, plaques. Transgenic mice have been developed that express one or more of the genes responsible for familial AD in humans. Doubly transgenic mice develop “human-like” plaques, providing a mechanism to study amyloid plaque biology in a controlled manner. Imaging of labeled plaques has been accomplished with other modalities, but only MRI has sufficient spatial and contrast resolution to visualize individual plaques non-invasively. Methods to optimize visualization of plaques in vivo in transgenic mice at 9.4 T using a spin echo sequence based on adiabatic pulses are described. Preliminary results indicate that a spin echo acquisition more accurately reflects plaque size, while a T2* weighted gradient echo sequence reflects plaque iron content not plaque size. In vivo MRI – ex vivo MRI – in vitro histological correlations are provided. Histologically verified plaques as small as 50 μm in diameter were visualized in the living animal. To our knowledge this work represents the first demonstration of non-invasive in vivo visualization of individual AD plaques without the use of a contrast agent. PMID:15562496

  8. 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

  9. 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

  10. 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

  11. [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.

  12. Classification of human coronary atherosclerotic plaques using ex vivo high-resolution multicontrast-weighted MRI compared with histopathology.

    PubMed

    Li, Tao; Li, Xin; Zhao, Xihai; Zhou, Weihua; Cai, Zulong; Yang, Li; Guo, Aitao; Zhao, Shaohong

    2012-05-01

    The objective of our study was to evaluate the feasibility of ex vivo high-resolution multicontrast-weighted MRI to accurately classify human coronary atherosclerotic plaques according to the American Heart Association classification. Thirteen human cadaver heart specimens were imaged using high-resolution multicontrast-weighted MR technique (T1-weighted, proton density-weighted, and T2-weighted). All MR images were matched with histopathologic sections according to the landmark of the bifurcation of the left main coronary artery. The sensitivity and specificity of MRI for the classification of plaques were determined, and Cohen's kappa analysis was applied to evaluate the agreement between MRI and histopathology in the classification of atherosclerotic plaques. One hundred eleven MR cross-sectional images obtained perpendicular to the long axis of the proximal left anterior descending artery were successfully matched with the histopathologic sections. For the classification of plaques, the sensitivity and specificity of MRI were as follows: type I-II (near normal), 60% and 100%; type III (focal lipid pool), 80% and 100%; type IV-V (lipid, necrosis, fibrosis), 96.2% and 88.2%; type VI (hemorrhage), 100% and 99.0%; type VII (calcification), 93% and 100%; and type VIII (fibrosis without lipid core), 100% and 99.1%, respectively. Isointensity, which indicates lipid composition on histopathology, was detected on MRI in 48.8% of calcified plaques. Agreement between MRI and histopathology for plaque classification was 0.86 (p < 0.001). Ex vivo high-resolution multicontrast-weighted MRI can accurately classify advanced atherosclerotic plaques in human coronary arteries.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Intravascular Ultrasound Classification of Plaque in Angiographic True Bifurcation Lesions of the Left Main Coronary Artery.

    PubMed

    Li, Li; Dash, Debabrata; Gai, Lu-Yue; Cao, Yun-Shan; Zhao, Qiang; Wang, Ya-Rong; Zhang, Yao-Jun; Zhang, Jun-Xia

    2016-07-05

    Accurately, characterizing plaques is critical for selecting the optimal intervention strategy for the left main coronary artery (LMCA) bifurcation. Coronary angiography cannot precisely assess the location or nature of plaques in bifurcation lesions. Few intravascular ultrasound (IVUS) classification scheme has been reported for angiographic imaging of true bifurcation lesions of the unprotected LMCA thus far. In addition, the plaque composition at the bifurcation has not been elucidated. This study aimed to detect plaque composition at LMCA bifurcation lesions by IVUS. Fifty-eight patients were recruited. The location, concentricity or eccentricity, site of maximum thickness, and composition of plaques of the distal LMCA, ostial left anterior descending (LAD) coronary artery and, left circumflex (LCX) coronary artery were assessed using IVUS and described using illustrative diagrams. True bifurcation lesions of the unprotected LMCA were classified into four types: Type A, with continuous involvement from the distal LMCA to the ostial LAD and the ostial LCX with eccentric plaques; Type B, with concentric plaques at the distal LMCA, eccentric plaques at the ostial LAD, and no plaques at the LCX; Type C, with continuous involvement from the distal LMCA to the ostial LCX, with eccentric plaques, and to the ostial LAD, with eccentric plaques; and Type D, with continuous involvement from the distal LMCA to the ostial LAD, with eccentric plaques, and to the ostial LCX, with concentric plaques. The carina was involved in only 3.5% of the plaques. A total of 51.7% of the plaques at the ostium of the LAD were soft, while 44.8% and 44.6% were fibrous in the distal LMCA and in the ostial LCX, respectively. We classified LMCA true bifurcation lesions into four types. The carina was always free from disease. Plaques at the ostial LAD tended to be soft, whereas those at the ostial LCX and the distal LMCA tended to be fibrous.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Characterization of lipid-rich plaques using spectroscopic optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Nam, Hyeong Soo; Song, Joon Woo; Jang, Sun-Joo; Lee, Jae Joong; Oh, Wang-Yuhl; Kim, Jin Won; Yoo, Hongki

    2016-07-01

    Intravascular optical coherence tomography (IV-OCT) is a high-resolution imaging method used to visualize the internal structures of walls of coronary arteries in vivo. However, accurate characterization of atherosclerotic plaques with gray-scale IV-OCT images is often limited by various intrinsic artifacts. In this study, we present an algorithm for characterizing lipid-rich plaques with a spectroscopic OCT technique based on a Gaussian center of mass (GCOM) metric. The GCOM metric, which reflects the absorbance properties of lipids, was validated using a lipid phantom. In addition, the proposed characterization method was successfully demonstrated in vivo using an atherosclerotic rabbit model and was found to have a sensitivity and specificity of 94.3% and 76.7% for lipid classification, respectively.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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 ...

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. An integrated method for atherosclerotic carotid plaque segmentation in ultrasound image.

    PubMed

    Qian, Chunjun; Yang, Xiaoping

    2018-01-01

    Carotid artery atherosclerosis is an important cause of stroke. Ultrasound imaging has been widely used in the diagnosis of atherosclerosis. Therefore, segmenting atherosclerotic carotid plaque in ultrasound image is an important task. Accurate plaque segmentation is helpful for the measurement of carotid plaque burden. In this paper, we propose and evaluate a novel learning-based integrated framework for plaque segmentation. In our study, four different classification algorithms, along with the auto-context iterative algorithm, were employed to effectively integrate features from ultrasound images and later also the iteratively estimated and refined probability maps together for pixel-wise classification. The four classification algorithms were support vector machine with linear kernel, support vector machine with radial basis function kernel, AdaBoost and random forest. The plaque segmentation was implemented in the generated probability map. The performance of the four different learning-based plaque segmentation methods was tested on 29 B-mode ultrasound images. The evaluation indices for our proposed methods were consisted of sensitivity, specificity, Dice similarity coefficient, overlap index, error of area, absolute error of area, point-to-point distance, and Hausdorff point-to-point distance, along with the area under the ROC curve. The segmentation method integrated the random forest and an auto-context model obtained the best results (sensitivity 80.4 ± 8.4%, specificity 96.5 ± 2.0%, Dice similarity coefficient 81.0 ± 4.1%, overlap index 68.3 ± 5.8%, error of area -1.02 ± 18.3%, absolute error of area 14.7 ± 10.9%, point-to-point distance 0.34 ± 0.10 mm, Hausdorff point-to-point distance 1.75 ± 1.02 mm, and area under the ROC curve 0.897), which were almost the best, compared with that from the existed methods. Our proposed learning-based integrated framework investigated in this study could be useful for

  4. 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).

  5. 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.

  6. 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.

  7. 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.

  8. Using reconstructed IVUS images for coronary plaque classification.

    PubMed

    Caballero, Karla L; Barajas, Joel; Pujol, Oriol; Rodriguez, Oriol; Radeva, Petia

    2007-01-01

    Coronary plaque rupture is one of the principal causes of sudden death in western societies. Reliable diagnostic of the different plaque types are of great interest for the medical community the predicting their evolution and applying an effective treatment. To achieve this, a tissue classification must be performed. Intravascular Ultrasound (IVUS) represents a technique to explore the vessel walls and to observe its histological properties. In this paper, a method to reconstruct IVUS images from the raw Radio Frequency (RF) data coming from ultrasound catheter is proposed. This framework offers a normalization scheme to compare accurately different patient studies. The automatic tissue classification is based on texture analysis and Adapting Boosting (Adaboost) learning technique combined with Error Correcting Output Codes (ECOC). In this study, 9 in-vivo cases are reconstructed with 7 different parameter set. This method improves the classification rate based on images, yielding a 91% of well-detected tissue using the best parameter set. It also reduces the inter-patient variability compared with the analysis of DICOM images, which are obtained from the commercial equipment.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. Advances in the development of an imaging device for plaque measurement in the area of the carotid artery.

    PubMed

    Ličev, Lačezar; Krumnikl, Michal; Škuta, Jaromír; Babiuch, Marek; Farana, Radim

    2014-03-04

    This paper describes the advances in the development and subsequent testing of an imaging device for three-dimensional ultrasound measurement of atherosclerotic plaque in the carotid artery. The embolization from the atherosclerotic carotid plaque is one of the most common causes of ischemic stroke and, therefore, we consider the measurement of the plaque as extremely important. The paper describes the proposed hardware for enhancing the standard ultrasonic probe to provide a possibility of accurate probe positioning and synchronization with the cardiac activity, allowing the precise plaque measurements that were impossible with the standard equipment. The synchronization signal is derived from the output signal of the patient monitor (electrocardiogram (ECG)), processed by a microcontroller-based system, generating the control commands for the linear motion moving the probe. The controlling algorithm synchronizes the movement with the ECG waveform to obtain clear images not disturbed by the heart activity.

  15. [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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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 ...

  4. Machine learning algorithm accurately detects fMRI signature of vulnerability to major depression.

    PubMed

    Sato, João R; Moll, Jorge; Green, Sophie; Deakin, John F W; Thomaz, Carlos E; Zahn, Roland

    2015-08-30

    Standard functional magnetic resonance imaging (fMRI) analyses cannot assess the potential of a neuroimaging signature as a biomarker to predict individual vulnerability to major depression (MD). Here, we use machine learning for the first time to address this question. Using a recently identified neural signature of guilt-selective functional disconnection, the classification algorithm was able to distinguish remitted MD from control participants with 78.3% accuracy. This demonstrates the high potential of our fMRI signature as a biomarker of MD vulnerability. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Positron autoradiography for intravascular imaging: feasibility evaluation

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Xu, Tong; Ducote, Justin L.; Easwaramoorthy, Balasubramaniam; Mukherjee, Jogeshwar; Molloi, Sabee

    2006-02-01

    experiments. Experiments showed that detecting the coronary plaques using the proposed technique is possible. The proposed technique has the potential for fast and accurate detection of vulnerable coronary and other intravascular plaques.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. The influence of computational strategy on prediction of mechanical stress in carotid atherosclerotic plaques: comparison of 2D structure-only, 3D structure-only, one-way and fully coupled fluid-structure interaction analyses.

    PubMed

    Huang, Yuan; Teng, Zhongzhao; Sadat, Umar; Graves, Martin J; Bennett, Martin R; Gillard, Jonathan H

    2014-04-11

    Compositional and morphological features of carotid atherosclerotic plaques provide complementary information to luminal stenosis in predicting clinical presentations. However, they alone cannot predict cerebrovascular risk. Mechanical stress within the plaque induced by cyclical changes in blood pressure has potential to assess plaque vulnerability. Various modeling strategies have been employed to predict stress, including 2D and 3D structure-only, 3D one-way and fully coupled fluid-structure interaction (FSI) simulations. However, differences in stress predictions using different strategies have not been assessed. Maximum principal stress (Stress-P1) within 8 human carotid atherosclerotic plaques was calculated based on geometry reconstructed from in vivo computerized tomography and high resolution, multi-sequence magnetic resonance images. Stress-P1 within the diseased region predicted by 2D and 3D structure-only, and 3D one-way FSI simulations were compared to 3D fully coupled FSI analysis. Compared to 3D fully coupled FSI, 2D structure-only simulation significantly overestimated stress level (94.1 kPa [65.2, 117.3] vs. 85.5 kPa [64.4, 113.6]; median [inter-quartile range], p=0.0004). However, when slices around the bifurcation region were excluded, stresses predicted by 2D structure-only simulations showed a good correlation (R(2)=0.69) with values obtained from 3D fully coupled FSI analysis. 3D structure-only model produced a small yet statistically significant stress overestimation compared to 3D fully coupled FSI (86.8 kPa [66.3, 115.8] vs. 85.5 kPa [64.4, 113.6]; p<0.0001). In contrast, one-way FSI underestimated stress compared to 3D fully coupled FSI (78.8 kPa [61.1, 100.4] vs. 85.5 kPa [64.4, 113.7]; p<0.0001). A 3D structure-only model seems to be a computationally inexpensive yet reasonably accurate approximation for stress within carotid atherosclerotic plaques with mild to moderate luminal stenosis as compared to fully coupled FSI analysis

  17. 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

  18. 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

  19. 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.

  20. [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.

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

    PubMed

    Poulsen, Christian B; Pedrigi, Ryan M; Pareek, Nilesh; Kilic, Ismail D; Holm, Niels Ramsing; Bentzon, Jacob F; Bøtker, Hans Erik; Falk, Erling; Krams, Rob; de Silva, Ranil

    2018-04-03

    In-vivo validation of coronary optical coherence tomography (OCT) against histology and the effects of plaque burden (PB) on plaque classification remain unreported. We investigated this in a porcine model with human-like coronary atherosclerosis. Five female Yucatan D374Y-PCSK9 transgenic hypercholesterolemic mini-pigs were implanted with a coronary shear-modifying stent to induce advanced atherosclerosis. OCT frames (n=201) were obtained 34 weeks after implantation. Coronary arteries were perfusion-fixed, serially sectioned and co-registered with OCT using a validated algorithm. Lesions were adjudicated using the Virmani classification and PB assessed from histology. OCT had a high sensitivity, but modest specificity (92.9% and 74.6%), for identifying fibrous cap atheroma (FCA). The reduced specificity for OCT was due to misclassification of plaques with histologically defined pathological intimal thickening (PIT) as FCA (46.1% of the frames with histological PIT were misclassified). PIT lesions misclassified as FCA by OCT had a statistically higher PB than in other OCT frames (median 32.0% versus 13.4%; p<0.0001). Misclassification of PIT lesions by OCT occurred when PB exceeded approximately 20%. Compared with histology, in-vivo OCT classification of FCA had high sensitivity but reduced specificity due to misclassification of PITs with high PB.

  2. Quantification In Situ of Crystalline Cholesterol and Calcium Phosphate Hydroxyapatite in Human Atherosclerotic Plaques by Solid-State Magic Angle Spinning NMR

    PubMed Central

    Guo, Wen; Morrisett, Joel D.; DeBakey, Michael E.; Lawrie, Gerald M.; Hamilton, James A.

    2010-01-01

    Because of renewed interest in the progression, stabilization, and regression of atherosclerotic plaques, it has become important to develop methods for characterizing structural features of plaques in situ and noninvasively. We present a nondestructive method for ex vivo quantification of 2 solid-phase components of plaques: crystalline cholesterol and calcium phosphate salts. Magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of human carotid endarterectomy plaques revealed 13C resonances of crystalline cholesterol monohydrate and a 31P resonance of calcium phosphate hydroxyapatite (CPH). The spectra were obtained under conditions in which there was little or no interference from other chemical components and were suitable for quantification in situ of the crystalline cholesterol and CPH. Carotid atherosclerotic plaques showed a wide variation in their crystalline cholesterol content. The calculated molar ratio of liquid-crystalline cholesterol to phospholipid ranged from 1.1 to 1.7, demonstrating different capabilities of the phospholipids to reduce crystallization of cholesterol. The spectral properties of the phosphate groups in CPH in carotid plaques were identical to those of CPH in bone. 31P MAS NMR is a simple, rapid method for quantification of calcium phosphate salts in tissue without extraction and time-consuming chemical analysis. Crystalline phases in intact atherosclerotic plaques (ex vivo) can be quantified accurately by solid-state 13C and 31PMAS NMR spectroscopy. PMID:10845882

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. [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.

  11. Contrast-enhanced ultrasonography vs B-mode ultrasound for visualization of intima-media thickness and detection of plaques in human carotid arteries.

    PubMed

    Shah, Benoy N; Chahal, Navtej S; Kooner, Jaspal S; Senior, Roxy

    2017-05-01

    Carotid intima-media thickness (IMT) and plaque are recognized markers of increased risk for cerebrovascular events. Accurate visualization of the IMT and plaques is dependent upon image quality. Ultrasound contrast agents improve image quality during echocardiography-this study assessed whether contrast-enhanced ultrasound (CEUS) improves carotid IMT visualization and plaque detection in an asymptomatic population. Individuals free from known cardiovascular disease, enrolled in a community study, underwent B-mode and CEUS carotid imaging. Each carotid artery was divided into 10 segments (far and near walls of the proximal, mid and distal segments of the common carotid artery, the carotid bulb, and internal carotid artery). Visualization of the IMT complex and plaque assessments was made during both B-mode and CEUS imaging for all enrolled subjects, a total of 175 individuals (mean age 65±9 years). Visualization of the IMT was significantly improved during CEUS compared with B-mode imaging, in both near and far walls of the carotid arteries (% IMT visualization during B-mode vs CEUS imaging: 61% vs 94% and 66% vs 95% for right and left carotid arteries, respectively, P<.001 for both). Additionally, a greater number of plaques were detected during CEUS imaging compared with B-mode imaging (367 plaques vs 350 plaques, P=.02). Contrast-enhanced ultrasound improves visualization of the intima-media complex, in both near and far walls, of the common and internal carotid arteries and permits greater detection of carotid plaques. Further studies are required to determine whether there is incremental clinical and prognostic benefit related to superior plaque detection by CEUS. © 2017, Wiley Periodicals, Inc.

  12. 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.

  13. 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

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

  14. 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

  15. 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.

  16. 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.

  17. Severity and prevalence of plaque-induced gingivitis in the Chinese population.

    PubMed

    Zhang, Jincai; Xuan, Dongying; Fan, Weihua; Zhang, Xiong; Dibart, Serge; De Vizio, William; Panagakos, Foti; Zhang, Yun-Po

    2010-10-01

    This study investigated the prevalence and severity of gingivitis and plaque in a representative Chinese population of adults. Using the Loe-Silness gingivitis index (GI) and the modified Quigley-Hein plaque index (PULI), researchers examined 1143 patients from Guangzhou, Shenyang, and Nanjing for the presence of gingivitis and plaque. A two-tailed t-test was used to determine significant differences in the GI and PLI scores between gender and urban/rural areas. The data pertaining to study sites and age groups were compared using the Kruskal-Wallis one-way analysis of variances (ANOVA) by ranks. The correlation between GI/PLI and age was examined using the Pearson correlation coefficient. Age differences among three sites were analyzed with the one-way ANOVA. The age and urban/rural compositions (mean age 42.2 years) paralleled the 2008 China census. The overall average and standard deviation of GI and PLI were 1.101 +/- 0.239 and 3.394 +/- 0.578, respectively. Age significantly correlated with GI and PLI (P < .0001). The PLI in males was significantly higher (P < .0001) than in females; however, no significant difference was noted between GI in males compared to females. Patients in rural areas showed a significantly higher GI and PLI (t = 7.723, P < .0001; t = 7.072, P < .0001) than those in urban ones. Clinical trials evaluating a product's antigingivitis efficacy should recruit participants from a population that represents accurately the intended product users. Variables should include gender, race, age, and geography.

  18. 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).

  19. 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

  20. 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.

  1. 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.

  2. Monte Carlo dosimetry for {sup 103}Pd, {sup 125}I, and {sup 131}Cs ocular brachytherapy with various plaque models using an eye phantom

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

    Lesperance, Marielle; Martinov, M.; Thomson, R. M., E-mail: rthomson@physics.carleton.ca

    critical ocular structures are generally delivered with plaques containing {sup 103}Pd seeds. Conclusions: The combined effects of ocular and plaque media on dose are significant and vary with plaque model and radionuclide, suggesting the importance of model-based dose calculations employing accurate ocular and plaque media and geometries for eye plaque brachytherapy.« less

  3. 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.

  4. 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

  5. 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.

  6. 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

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

    PubMed Central

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

    2012-01-01

    Amyloid-β plaques are an Alzheimer’s disease biomarker which present unique challenges for near-infrared fluorescence tomography because of size (<50 μm diameter) and distribution. We used high-resolution simulations of fluorescence in a digital Alzheimer’s disease mouse model to investigate the optimal fluorophore and imaging parameters for near-infrared fluorescence tomography of amyloid plaques. Fluorescence was simulated for amyloid-targeted probes with emission at 630 and 800 nm, plaque-to-background ratios from 1–1000, amyloid burden from 0–10%, and for transmission and reflection measurement geometries. Fluorophores with high plaque-to-background contrast ratios and 800 nm emission performed significantly better than current amyloid imaging probes. We tested idealized fluorophores in transmission and full-angle tomographic measurement schemes (900 source–detector pairs), with and without anatomical priors. Transmission reconstructions demonstrated strong linear correlation with increasing amyloid burden, but underestimated fluorescence yield and suffered from localization artifacts. Full-angle measurements did not improve upon the transmission reconstruction qualitatively or in semi-quantitative measures of accuracy; anatomical and initial-value priors did improve reconstruction localization and accuracy for both transmission and full-angle schemes. Region-based reconstructions, in which the unknowns were reduced to a few distinct anatomical regions, produced highly accurate yield estimates for cortex, hippocampus and brain regions, even with a reduced number of measurements (144 source–detector pairs). PMID:19794239

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Practical direct plaque assay for coliphages in 100-ml samples of drinking water.

    PubMed Central

    Grabow, W O; Coubrough, P

    1986-01-01

    A practical single-agar-layer plaque assay for the direct detection of coliphages in 100-ml samples of water was designed and evaluated. With this assay a 100-ml sample of water, an agar medium containing divalent cations, and the host Escherichia coli C (ATCC 13706) were mixed in a single container, and the mixture was plated on 10 14-cm-diameter petri dishes. It was more sensitive, reliable, and accurate than various other methods and proved rapid, simple, and economic. PMID:3532952

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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 (

  4. 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

  5. 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

  6. 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

  7. SU-F-T-51: Investigating the Effect of Eye Size and Eccentricity On Normal Tissue Doses From Eye Plaque Brachytherapy

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

    Polsdofer, E; Crilly, R

    Purpose: This study investigates the effect of eye size and eccentricity on doses to critical tissues by simulating doses in the Plaque Simulator (v. 6.3.1) software. Present OHSU plaque brachytherapy treatment focuses on delivering radiation to the tumor measured with ocular ultrasound plus a small margin and assumes the orbit has the dimensions of a “standard eye.” Accurately modeling the dimensions of the orbit requires a high resolution ocular CT. This study quantifies how standard differences in equatorial diameters and eccentricity affect calculated doses to critical structures in order to query the justification of the additional CT scan to themore » treatment planning process. Methods: Tumors of 10 mm × 10 mm × 5 mm were modeled at the 12:00:00 hour with a latitude of 45 degrees. Right eyes were modeled at a number of equatorial diameters from 17.5 to 28 mm for each of the standard non-notched COMS plaques with silastic inserts. The COMS plaques were fully loaded with uniform activity, centered on the tumor, and prescribed to a common tumor dose (85 Gy/100 hours). Variations in the calculated doses to normal structures were examined to see if the changes were significant. Results: The calculated dose to normal structures show a marked dependence on eye geometry. This is exemplified by fovea dose which more than doubled in the smaller eyes and nearly halved in the larger model. Additional significant dependence was found in plaque size on the calculated dose in spite of all plaques giving the same dose to the prescription point. Conclusion: The variation in dose with eye dimension fully justifies the addition of a high resolution ocular CT to the planning technique. Additional attention must be made to plaque size beyond simply covering the tumor when considering normal tissue dose.« less

  8. A pragmatic analysis of vulnerability in clinical research.

    PubMed

    Wendler, David

    2017-09-01

    Identifying which subjects are vulnerable, and implementing safeguards to protect them, is widely regarded as essential to clinical research. Commentators have endorsed a number of responses to these challenges and have thereby made significant progress in understanding vulnerability in clinical research. At the same time, this literature points to a central contradiction which calls into question its potential to protect vulnerable subjects in practice. Specifically, analysis suggests that all human subjects are vulnerable and vulnerability in clinical research is comparative and context dependent, in the sense that individuals are vulnerable relative to others and in some contexts only. Yet, if everyone is vulnerable, there seems to be no point in citing the vulnerability of some individuals. Moreover, the conclusion that everyone is vulnerable seems inconsistent with the claims that vulnerability is comparative and context dependent, raising concern over whether it will be possible to develop a comprehensive account of vulnerability that is internally consistent. The solution to this dilemma lies in recognition of the fact that the practical significance of claims regarding vulnerability depends on the context in which they are used. The claims that appear to lead to the central contradiction are in fact accurate conclusions that follow from different uses of the term 'vulnerability'. The present manuscript describes this 'pragmatic' approach to vulnerability in clinical research and considers its implications for ensuring that subjects receive appropriate protection. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Assessing intrinsic and specific vulnerability models ability to indicate groundwater vulnerability to groups of similar pesticides: A comparative study

    USGS Publications Warehouse

    Douglas, Steven; Dixon, Barnali; Griffin, Dale W.

    2018-01-01

    With continued population growth and increasing use of fresh groundwater resources, protection of this valuable resource is critical. A cost effective means to assess risk of groundwater contamination potential will provide a useful tool to protect these resources. Integrating geospatial methods offers a means to quantify the risk of contaminant potential in cost effective and spatially explicit ways. This research was designed to compare the ability of intrinsic (DRASTIC) and specific (Attenuation Factor; AF) vulnerability models to indicate groundwater vulnerability areas by comparing model results to the presence of pesticides from groundwater sample datasets. A logistic regression was used to assess the relationship between the environmental variables and the presence or absence of pesticides within regions of varying vulnerability. According to the DRASTIC model, more than 20% of the study area is very highly vulnerable. Approximately 30% is very highly vulnerable according to the AF model. When groundwater concentrations of individual pesticides were compared to model predictions, the results were mixed. Model predictability improved when concentrations of the group of similar pesticides were compared to model results. Compared to the DRASTIC model, the AF model more accurately predicts the distribution of the number of contaminated wells within each vulnerability class.

  11. 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

  12. 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.

  13. 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

  14. 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

  15. Towards a definition of orphaned and vulnerable children.

    PubMed

    Skinner, Donald; Tsheko, N; Mtero-Munyati, S; Segwabe, M; Chibatamoto, P; Mfecane, S; Chandiwana, B; Nkomo, N; Tlou, S; Chitiyo, G

    2006-11-01

    The HIV epidemic presents challenges including orphans and a large mass of children rendered vulnerable by the epidemic and other societal forces. Focus on orphaned and vulnerable children (OVC) is important, but needs accurate definition. Twelve focus group interviews of service providers, leaders in these communities, OVC and their caretakers were conducted at six project sites across Botswana, South Africa and Zimbabwe to extend this definition. The loss of a parent through death or desertion is an important aspect of vulnerability. Additional factors leading to vulnerability included severe chronic illness of a parent or caregiver, poverty, hunger, lack of access to services, inadequate clothing or shelter, overcrowding, deficient caretakers, and factors specific to the child, including disability, direct experience of physical or sexual violence, or severe chronic illness. Important questions raised in this research include the long-term implications for the child and community, and the contribution of culture systems.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Risk assessment by dynamic representation of vulnerability, exploitation, and impact

    NASA Astrophysics Data System (ADS)

    Cam, Hasan

    2015-05-01

    Assessing and quantifying cyber risk accurately in real-time is essential to providing security and mission assurance in any system and network. This paper presents a modeling and dynamic analysis approach to assessing cyber risk of a network in real-time by representing dynamically its vulnerabilities, exploitations, and impact using integrated Bayesian network and Markov models. Given the set of vulnerabilities detected by a vulnerability scanner in a network, this paper addresses how its risk can be assessed by estimating in real-time the exploit likelihood and impact of vulnerability exploitation on the network, based on real-time observations and measurements over the network. The dynamic representation of the network in terms of its vulnerabilities, sensor measurements, and observations is constructed dynamically using the integrated Bayesian network and Markov models. The transition rates of outgoing and incoming links of states in hidden Markov models are used in determining exploit likelihood and impact of attacks, whereas emission rates help quantify the attack states of vulnerabilities. Simulation results show the quantification and evolving risk scores over time for individual and aggregated vulnerabilities of a network.

  9. 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.

  10. 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

    .54; 95% CI 1.84, 16.68). Alternatively, smoking was the strongest predictor for the presence of >/=2 coronary segments with NCAP (OR 4.86; 95% CI 1.68, 14.07). Low-density lipoprotein cholesterol (LDL-C) was only a predictor for the presence and extent of mixed coronary plaque. Age and gender are overall the strongest predictors of atherosclerosis as assessed by CCTA in this large asymptomatic Korean population and these two risk factors are not particularly associated with a specific coronary plaque sub-type. Smoking is a strong predictor of NCAP, which has been suggested by previous reports as a more vulnerable lesion. Whether a specific plaque sub-type is associated with a worse prognosis is yet to be determined by future prospective studies.

  11. Mechanical properties of human atherosclerotic intima tissue.

    PubMed

    Akyildiz, Ali C; Speelman, Lambert; Gijsen, Frank J H

    2014-03-03

    Progression and rupture of atherosclerotic plaques in coronary and carotid arteries are the key processes underlying myocardial infarctions and strokes. Biomechanical stress analyses to compute mechanical stresses in a plaque can potentially be used to assess plaque vulnerability. The stress analyses strongly rely on accurate representation of the mechanical properties of the plaque components. In this review, the composition of intima tissue and how this changes during plaque development is discussed from a mechanical perspective. The plaque classification scheme of the American Heart Association is reviewed and plaques originating from different vascular territories are compared. Thereafter, an overview of the experimental studies on tensile and compressive plaque intima properties are presented and the results are linked to the pathology of atherosclerotic plaques. This overview revealed a considerable variation within studies, and an enormous dispersion between studies. Finally, the implications of the dispersion in experimental data on the clinical applications of biomechanical plaque modeling are presented. Suggestions are made on mechanical testing protocol for plaque tissue and on using a standardized plaque classification scheme. This review identifies the current status of knowledge on plaque mechanical properties and the future steps required for a better understanding of the plaque type specific material properties. With this understanding, biomechanical plaque modeling may eventually provide essential support for clinical plaque risk stratification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Aspirin inhibits human telomerase activation in unstable carotid plaques

    PubMed Central

    LI, FANGMING; GUO, YI; JIANG, XIN; ZHONG, JIANXIN; LI, GUANDONG; SUN, SHENGGANG

    2013-01-01

    The activation of telomerase in unstable plaques is an important factor in atherosclerosis, and may be predictive of the risk of cerebrovascular diseases. Human telomerase reverse transcriptase (hTERT) is a subunit of telomerase that is essential for telomerase activation. The aim of the present study was to investigate whether aspirin inhibits the activation of telomerase and hTERT in unstable carotid plaques. Polymorphonuclear neutrophils (PMNs) derived from carotid plaques were isolated from the washing medium of angioplasty balloons, while circulating PMNs, isolated from arterial blood, served as the controls. A polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) enzyme-linked immunosorbent assay (ELISA) was used to measure the telomerase activity in the cells following treatment with aspirin. The mRNA and protein expression of hTERT were detected by a reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis, respectively. The results revealed that the atherosclerotic plaques were positive for telomerase activity, and that aspirin inhibited the telomerase activity of the PMNs derived from the plaques. In addition, aspirin was demonstrated to inhibit the mRNA and protein expression of hTERT through the suppression of hTERT transcriptional activity; however, it had no inhibitory effect on the telomerase activity of the circulating PMNs. Thus, the activation of telomerase in resident PMNs is critical in the instability of carotid plaques. The upregulation of telomerase and hTERT during the progression of atherosclerosis may indicate a role for telomerase in the vascular remodeling that occurs during atherogenesis. Aspirin was demonstrated to inhibit the activation of telomerase via an hTERT-dependent manner in the PMN cells of unstable carotid plaques, and thus hTERT may be considered as a target in the treatment of cerebrovascular diseases. PMID:23935747

  18. Quantitative analysis of the polarization characteristics of atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Gubarkova, Ekaterina V.; Kirillin, Michail Y.; Dudenkova, Varvara V.; Kiseleva, Elena B.; Moiseev, Alexander A.; Gelikonov, Grigory V.; Timofeeva, Lidia B.; Fiks, Ilya I.; Feldchtein, Felix I.; Gladkova, Natalia D.

    2016-04-01

    In this study we demonstrate the capability of cross-polarization optical coherence tomography (CP OCT) to assess collagen and elastin fibers condition in atherosclerotic plaques basing on ratio of the OCT signal levels in cross- and co- polarizations. We consider the depolarization factor (DF) and the effective birefringence (Δn) as quantitative characteristics of CP OCT images. We revealed that calculation of both DF and Δn in the region of interest (fibrous cap) yields a statistically significant difference between stable and unstable plaques (0.46+/-0.21 vs 0.09+/-0.04 for IDF; (4.7+/-1.0)•10-4 vs (2.5+/-0.7)•10-4 for Δn p<0.05). In parallel with CP OCT we used the nonlinear microscopy for analysis of thin cross-section of atherosclerotic plaque, revealing the different average isotropy index of collagen and elastin fibers for stable and unstable plaques (0.30 +/- 0.10 vs 0.70 +/- 0.08; p<0.001). The proposed approach for quantitative assessment of CP OCT images allows cross-scattering and birefringence characterization of stable and unstable atherosclerotic plaques.

  19. Effect of baking soda in dentifrices on plaque removal.

    PubMed

    Myneni, Srinivas R

    2017-11-01

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

  20. 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.

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

    PubMed

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

    2017-09-01

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

  2. Plaque formation and removal assessed in vivo in a novel repeated measures imaging methodology.

    PubMed

    White, Donald J; Kozak, Kathy M; Baker, Rob; Saletta, Lisa

    2006-01-01

    A repeated measures digital imaging technique (Digital Plaque Image Analysis) was used to assess variations in plaque formation, including levels of plaque developed following evening and morning tooth brushing with a standard dentifrice, to establish a baseline for future assessments of antimicrobial formulations. Following a rigorous oral hygiene period, subjects were provided with a standard commercial (non-antibacterial) dentifrice and manual toothbrush and instructed to brush b.i.d., as normal. On six separate days over two weeks, subjects reported at three times for a daily plaque assessment: in the morning before oral hygiene, post-brushing, and in the afternoon post-brushing. Morning plaque levels covered approximately 10% of the measured dentition, and plaque was removed by 75% with morning tooth brushing. Plaque underwent rapid regrowth during the day, and averaged approximately 7% coverage by the afternoon. These results support the value of Digital Plaque Image Analysis in recording diurnal plaque variations and treatment effects, and suggest that assessment of oral hygiene efficacy (either mechanical or chemopreventive) accounts for diurnal variations in plaque formation. In addition, the results suggest that plaque regrowth and virulence activity overnight is a significant target for oral hygiene interventions.

  3. 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.

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

    PubMed Central

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

    1969-01-01

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

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

    PubMed

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

    2010-01-01

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

  6. Clinical comparison of plaque inhibition effects of a novel stabilized stannous fluoride dentifrice and a chlorhexidine digluconate dentifrice using digital plaque imaging.

    PubMed

    Bellamy, P G; Boulding, A; Farmer, S; Day, T N; Mussett, A J; Barker, M L

    2011-01-01

    To compare the plaque inhibition efficacy of a novel 0.454% stannous fluoride (SnF2) test dentifrice with sodium hexametaphosphate and stannous chloride to a chlorhexidine digluconate (0.05%), aluminium lactate (0.8%), and aluminium fluoride marketed control dentifrice (Lacalut Aktiv or AlF3/Chx). This was a randomized, two-treatment, two-period, double-blind crossover study that compared the SnF2 test dentifrice to the AlF3/Chx control dentifrice. Each of the two treatment periods lasted for 17 consecutive days of product use, during which subjects were required to brush twice per day with their assigned dentifrice using a standard manual toothbrush (Oral-B P35 Indicator). The two periods of the crossover were separated by a four-day washout period. Plaque levels on the facial anterior tooth surfaces were evaluated and averaged among three assessment days at the end of each treatment period using digital plaque imaging analysis (DPIA). The evening prior to assessments, subjects only brushed lingual surfaces. Assessment time points were carried out in the morning following no morning brushing (A.M. pre-brush), following 40 seconds of brushing with the assigned dentifrice (A.M. post-brush), and in the afternoon (P.M.). The DPIA captured images were used to calculate and analyze visible plaque coverage. Twenty-eight subjects were randomized and completed the study. At each assessment time point, the SnF2 test dentifrice demonstrated a statistically significant lower plaque level compared to the AlF3/Chx dentifrice: A.M. mean pre-brush 15.9% lower, p < 0.05; A.M. mean post-brush 22.2% lower, p < 0.05; P.M. mean 24.3% lower, p < 0.005. Compared to the AlF3/Chx control dentifrice, the novel SnF2 test dentifrice significantly inhibited plaque regrowth overnight and during the day. Immediately after brushing there was also significantly less plaque coverage with the SnF2 test dentifrice.

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

    PubMed

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

    2010-01-01

    The aim of this study was to determine the contribution of plaque and saliva towards the prolonged activity, also called substantivity, of three antimicrobial mouthrinses (Listerine®, Meridol®, Crest Pro Health®), used in combination with a toothpaste (Prodent Coolmint®). Volunteers brushed for 4 weeks with a toothpaste without antimicrobial claims, while during the last 2 weeks half of the volunteers used an antimicrobial mouthrinse in addition to brushing. At the end of the experimental period, plaque and saliva samples were collected 6 h after oral hygiene, and bacterial concentrations and viabilities were determined. The contribution of plaque and saliva towards substantivity was assessed by combining plaque obtained after mechanical cleaning only with plaque and saliva obtained after additional use of an antimicrobial rinse. Subsequently, resulting viabilities of the combined plaques were determined. The viabilities of plaque samples after additional rinsing with mouthrinses were lower than of plaque obtained after mechanical cleaning only, regardless of the rinse involved. Moreover, plaque collected 6 h after rinsing with antimicrobial mouthrinses contained a surplus of antimicrobial activity. Only Listerine showed decreased viability in saliva, but none of the mouthrinses showed any residual antimicrobial activity in saliva. The findings indicate that plaque left behind after mechanical cleaning contributes to the prolonged substantivity of antimicrobial mouthrinses. Copyright © 2010 S. Karger AG, Basel.

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

    PubMed

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

    2012-04-01

    Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections. However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique and to compare it with the effect of NaCl and chlorhexidine (CHX), 18 subjects had to refrain from all mechanical and chemical hygiene measures for 24 h. A voluminous supragingival plaque sample was taken from the buccal surfaces of the lower molars and wiped on an objective slide. The sample was then divided into three equal parts and mounted with one of the three test or control preparations (a) NaCl, (b) taurolidine 2% and (c) CHX 0.2%. After a reaction time of 2 min, the test solutions were sucked of. Subsequently, the plaque biofilm was stained with fluorescence dye and vitality of the plaque flora was evaluated under the fluorescence microscope (VF%). Plaque samples treated with NaCl showed a mean VF of 82.42 ± 6.04%. Taurolidine affected mean VF with 47.57 ± 16.60% significantly (p < 0.001, paired t test). The positive control CHX showed the lowest mean VF values (34.41 ± 14.79%; p < 0.001 compared to NaCl, p = 0.017 compared to taurolidine). Taurolidine possesses a significant antibacterial effect on the supragingival plaque biofilm which was, however, not as pronounced as that of CHX.

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

    PubMed

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

    2015-01-01

    To evaluate supragingival and subgingival plaque formation on the dentogingival area in smokers and never smokers using the experimental gingivitis model and a plaque scoring system that considers the presence of an area free of plaque between plaque and the gingival sulcus called the plaque free zone (PFZ). Male volunteers, 9 current smokers and 10 never-smokers, refrained from oral hygiene procedures in the maxillary incisors and canines (test teeth) for 25 days. Under conditions of clinically healthy gingiva (phase 1) and gingival inflammation (phase 2), the supragingival plaque formation pattern was observed for 4 days in the dentogingival area. Gingival crevicular fluid was also measured. Plaque was dyed with fucsine and its presence was recorded by a calibrated examiner based on a 3-criteria scoring system: 0 - absence of stained plaque; 1 - presence of stained plaque and supragingival PFZ; 2 - presence of stained plaque and absence of PFZ, indicating that subgingival plaque formation has taken place. In both phases, smokers presented a significantly lower relative frequency of sites with subgingival plaque compared to never-smokers (P < 0.001). Mean gingival crevicular fluid was significantly higher in the presence of gingival inflammation for both groups (P = 0.001), whereas smokers demonstrated a significantly lower frequency of gingival bleeding than did non-smokers (23.6% vs 66.1%; P < 0.001). Smokers presented significantly lower percentages of sites with subgingival plaque in all experimental periods and presented less gingival inflammation as shown by GBI and gingival crevicular fluid quantification.

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

    PubMed

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

    2017-03-01

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

  11. Plaque removal efficacy of two children's toothbrushes: a one-month study.

    PubMed

    Benson, B J; Henyon, G; Grossman, E

    1993-01-01

    Reach Wonder Grip toothbrush for children was evaluated for plaque removal efficacy and compared to the Colgate Plus Junior (extra soft). The subjects appeared at the test site with overnight (14-18 hours) plaque accumulation. After qualifying for the study, sixty-eight (68) subjects were randomly assigned one of the test brushes. They then participated in the test evaluation at the clinical site wherein plaque levels were measured before and after a one minute brushing. Plaque removal efficacy was evaluated by the Global Plaque Index (percent of tooth surface covered by stained deposit). The subjects then used the assigned toothbrush at home for one month and returned to the test site to repeat the baseline evaluations. After their final plaque evaluations, the subjects were given a new toothbrush from each brand to use at home for one week and the subject and the parent were asked to complete a preference questionnaire. Sixty-seven (67) subjects completed the one month study. After one month's use of twice per day brushing, neither of the test toothbrushes demonstrated any evidence of oral irritation that could be related to toothbrushing. The results indicated that Reach Wonder Grip for Children was significantly more effective (p < 0.05) than Colgate Plus Junior in removing overall (Global) plaque at the initial exam period. The preference questionnaire indicated that the Reach Wonder Grip toothbrush was preferred by both the children and their parents. It is concluded that the new Reach Wonder Grip toothbrush for children is safe and effective for plaque removal.

  12. Quantitative real-time polymerase chain reaction for Streptococcus mutans and Streptococcus sobrinus in dental plaque samples and its association with early childhood caries.

    PubMed

    Choi, Eun-Jung; Lee, Sung-Hoon; Kim, Young-Jae

    2009-03-01

    Streptococcus mutans and Streptococcus sobrinus are closely associated with the development of early childhood caries (ECC). Recently, quantitative real-time polymerase chain reaction (qRT-PCR) has been used for rapid and accurate quantification of these bacterial species. This study aims to detect quantitatively the levels of S. mutans and S. sobrinus in plaque samples by qRT-PCR, and to assess their association with the prevalence of ECC in Korean preschool children. One hundred and five children (71 months old or younger) were examined and classified into three groups (caries-free, ECC, severe ECC). Dental plaque samples were collected and qRT-PCR was conducted using oligonucleotide primers specific for glucosyltransferase gene (S. mutans-gtfB, S. sobrinus-gtfU) and universal primer. Pearson's correlation test was conducted to evaluate the relationship between the dmfs (decayed, missing, or filled surfaces primary teeth) scores and the microbiological findings. There was a significant difference between the levels of S. mutans and S. sobrinus in the plaque samples of the three groups (P < 0.05). The proportion of S. sobrinus to S. mutans showed strong correlation to the dmfs scores (r = 0.748, P < 0.05). The qRT-PCR results of this study showed that children with ECC had higher level of S. mutans and S. sobrinus in their dental plaque samples. The children with higher ratio of S. sobrinus to S. mutans in their dental plaque showed higher incidence of ECC.

  13. View of plaque Apollo 11 astronauts left on moon

    NASA Image and Video Library

    1969-07-20

    AS11-40-5899 (20 July 1969) --- Close-up view of the plaque which the Apollo 11 astronauts left on the moon in commemoration of the historic lunar landing mission. The plaque was attached to the ladder on the landing gear strut on the descent stage of the Apollo 11 Lunar Module (LM). The plaque was covered with a thin sheet of stainless steel during flight. Astronaut Michael Collins, command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit while astronauts Neil A. Armstrong, commander, and Edwin E. Aldrin Jr., lunar module pilot, explored the moon.

  14. 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.

  15. Comparative effect of chewing sticks and toothbrushing on plaque removal and gingival health.

    PubMed

    Al-Otaibi, Meshari; Al-Harthy, Mohammed; Söder, Birgitta; Gustafsson, Anders; Angmar-Månsson, Birgit

    2003-01-01

    The aim of the study was to compare the effect of the chewing stick (miswak), and toothbrushing on plaque removal and gingival health. The participants comprised 15 healthy Saudi Arabian male volunteers aged 21 to 36 years, attending the Dental Center at Al-Noor Specialist Hospital in Makkah City in Saudi Arabia. The study was designed as a single, blind, randomized crossover study. The Turesky modified Quigley-Hein plaque and Löe-Silness gingival indices and digital photographs of plaque distribution were recorded at baseline, one week after professional tooth cleaning, and again following three weeks use of either the miswak or toothbrush. Professional tooth cleaning was repeated, and after a further three weeks use of either the miswak or toothbrush (using the alternative method to that used in the first experimental period), plaque and gingival indices, and digital photographs of plaque distribution were recorded anew. Compared to toothbrushing, the use of the miswak resulted in significant reductions in plaque (p < 0.001) and gingival (p < 0.01) indices. Image analysis of the plaque distribution showed a significant difference in reduction of plaque between the miswak and toothbrush periods (p < 0.05). It is concluded that the miswak is more effective than toothbrushing for reducing plaque and gingivitis, when preceded by professional instruction in its correct application. The miswak appeared to be more effective than toothbrushing for removing plaque from the embrasures, thus enhancing interproximal health.

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

    PubMed

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

    2010-01-01

    Plaque 'calcium-fluoride-like' (CaF(2)-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 microg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF(2)-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF(2)-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF(2)-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF(2)-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF(2)-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses. (c) 2010 S. Karger AG, Basel.

  17. No Calcium-Fluoride-Like Deposits Detected in Plaque Shortly after a Sodium Fluoride Mouthrinse

    PubMed Central

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

    2010-01-01

    Plaque ‘calcium-fluoride-like’ (CaF2-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 μg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF2-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF2-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF2-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF2-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF2-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses. PMID:20185917

  18. Assessing landscape vulnerability to wildfire in the USA

    Treesearch

    Nicole M. Vaillant; Crystal A. Kolden; Alistair M. S. Smith

    2016-01-01

    Wildfire is an ever present, natural process shaping landscapes. Having the ability to accurately measure and predict wildfire occurrence and impacts to ecosystem goods and services, both retrospectively and prospectively, is critical for adaptive management of landscapes. Landscape vulnerability is a concept widely utilized in the ecosystem management literature that...

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

    PubMed

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

    2010-06-28

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

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

    PubMed Central

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

    2010-01-01

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

  1. Gender differences in coronary plaque composition by coronary computed tomography angiography.

    PubMed

    Blaha, Michael J; Nasir, Khurram; Rivera, Juan J; Choi, Eue-Keun; Chang, Sung-A; Yoon, Yeonyee E; Chun, Eun Ju; Choi, Sang-il; Agatston, Arthur; Blumenthal, Roger S; Chang, Hyuk-Jae

    2009-12-01

    Coronary computed tomography angiography allows the differentiation of non-calcified (NCAP), calcified (CAP), and mixed coronary artery plaques (MCAP). Although males are thought to have a higher prevalence of atherosclerosis for a given age, there are currently few data regarding age-adjusted sex differences in plaque morphology and composition. We studied 1015 consecutive asymptomatic South Korean patients (49+/-10 years, 64% men) who underwent 64-slice coronary computed tomography angiography during a routine health evaluation. Coronary plaque characteristics were analyzed on a per-segment basis according to the modified AHA classification. Plaques with more than 50% calcified tissue were classified as CAP, plaques with less than 50% calcified tissue were classified as MCAP, and plaques without calcium were classified as NCAP. Multiple regression analysis was used to describe the cross-sectional association between sex and plaque-type burden (>or=2 affected segments) after adjustment for age and other cardiovascular risk factors. There was a greater prevalence of coronary plaque among men (13 vs. 4%, P<0.001). Males were more likely to have an increased burden of CAP (4 vs. 1%, P = 0.01) and MCAP (5 vs. 1%, P<0.001), whereas the burden of NCAP was similar across sex (2 vs. 1%, P = 0.28). After multivariable adjustment, men have six to seven times greater odds of having an increased burden of CAP and MCAP, whereas no sex difference was observed in the burden of NCAP. In this population of asymptomatic middle-aged Korean individuals, males had a significantly greater burden of MCAP and CAP. Future studies will determine whether these differences contribute to the accelerated cardiovascular risk observed in men.

  2. Prevention of artificial dental plaque formation in vitro by plant extracts.

    PubMed

    Smullen, J; Finney, M; Storey, D M; Foster, H A

    2012-10-01

    A number of previous studies have shown that plant extracts can inhibit formation of dental plaque. The ability of extracts of Rosmarinus officianalis L., Salvia officianalis L., unfermented cocoa, red grape seed and green tea to inhibit plaque bacteria, glucosyltransferase activity, glucan and plaque formation in an in vitro model using bovine teeth was examined. The antimicrobial activity of the plant extracts against oral bacteria was determined using a standard susceptibility agar dilution technique. Inhibition of growth and acid production from glucose and sucrose by Streptococcus mutans in liquid culture was investigated. Prevention of plaque formation on bovine teeth initiated by Strep. mutans was studied using an artificial mouth. The plant extracts inhibited the growth of oral bacteria and prevented acid production by Strep. mutans. Extracts inhibited glucosyltransferase activity and glucan production and inhibited adhesion to glass. Extracts of R. officianalis L. and S. officianalis L. at 0·25 mg ml(-1) reduced plaque growth by >80%. Green tea extract completely inhibited plaque formation but resulted in a greenish discolouration of the teeth which could not be removed by scrubbing. The plant extracts, particularly those from R. officianalis L. and S. officianalis L., inhibited glucosyltranferase activity, glucan production and plaque formation in vitro. The results suggest that the extracts of R. officianalis L. and S. officianalis L. may be useful as antiplaque agents in foods and dental preparations. Bovine teeth can be used as an alternative to hydroxyapatite for studies of plaque formation, but they need to be carefully sterilized before use. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  3. [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.

  4. 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

  5. Advanced Collapsed cone Engine dose calculations in tissue media for COMS eye plaques loaded with I-125 seeds.

    PubMed

    Morrison, Hali; Menon, Geetha; Larocque, Matthew P; van Veelen, Bob; Niatsetski, Yury; Weis, Ezekiel; Sloboda, Ron S

    2018-05-04

    data more closely than water-based data, even in regions where the ACE accuracy was relatively low. However, depending on the plaque position, doses to critical structures near the plaque penumbra or at tissue interfaces were less accurate, indicating that improvements may be necessary. More extensive knowledge of eye tissue compositions is still required. © 2018 American Association of Physicists in Medicine.

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

    PubMed Central

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

    1983-01-01

    Plaques formed by herpes simplex virus (HSV), pseudorabies virus, and varicella-zoster virus were studied by plaque autoradiography after [14C]thymidine labeling. Standard thymidine kinase-positive (TK+) viruses and TK- mutants of HSV types 1 and 2 and pseudorabies virus were studied, including cell cultured viruses and viruses isolated from animals. Autoradiography was performed with X-ray film with an exposure time of 5 days. After development of films, TK+ plaques showed dark rims due to isotope incorporation, whereas TK- plaques were minimally labeled. Plaque autoradiography of stock TK- viruses showed reversion frequencies to the TK+ phenotype of less than 10(-3). Autoradiography indicated that TK- virus retained the TK- phenotype after replication in vivo. In addition, it was shown that TK- HSV could be isolated from mouse trigeminal ganglion tissue after corneal inoculation of TK- HSV together with TK+ HSV. The plaque autoradiographic procedure was very useful to evaluate proportions of TK+ and TK- virus present in TK+-TK- virus mixtures. Images PMID:6826696

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

    PubMed

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

    2011-12-01

    The purpose of this study was to describe the pattern of dental plaque accumulation in mechanically ventilated adults. Accumulation of dental plaque and bacterial colonisation of the oropharynx is associated with a number of systemic diseases including ventilator associated pneumonia. Data were collected from mechanically ventilated critically ill adults (n=137), enrolled within 24 hours of intubation. Dental plaque, counts of decayed, missing and filled teeth and systemic antibiotic use was assessed on study days 1, 3, 5 and 7. Dental plaque averages per study day, tooth type and tooth location were analysed. Medical respiratory, surgical trauma and neuroscience ICU's of a large tertiary care centre in the southeast United States. Plaque: all surfaces >60% plaque coverage from day 1 to day 7; molars and premolars contained greatest plaque average >70%. Systemic antibiotic use on day 1 had no significant effect on plaque accumulation on day 3 (p=0.73). Patients arrive in critical care units with preexisting oral hygiene issues. Dental plaque tends to accumulate in the posterior teeth (molars and premolars) that may be hard for nurses to visualise and reach; this problem may be exacerbated by endotracheal tubes and other equipment. Knowing accumulation trends of plaque will guide the development of effective oral care protocols. Published by Elsevier Ltd.

  8. Myocardial Bridge and Acute Plaque Rupture

    PubMed Central

    Perl, Leor; Daniels, David; Schwartz, Jonathan; Tanaka, Shige; Yeung, Alan; Tremmel, Jennifer A.; Schnittger, Ingela

    2016-01-01

    A myocardial bridge (MB) is a common anatomic variant, most frequently located in the left anterior descending coronary artery, where a portion of the coronary artery is covered by myocardium. Importantly, MBs are known to result in a proximal atherosclerotic lesion. It has recently been postulated that these lesions predispose patients to acute coronary events, even in cases of otherwise low-risk patients. One such mechanism may involve acute plaque rupture. In this article, we report 2 cases of patients with MBs who presented with acute coronary syndromes despite having low cardiovascular risk. Their presentation was life-risking and both were treated urgently and studied with coronary angiographies and intravascular ultrasound. This latter modality confirmed a rupture of an atherosclerotic plaque proximal to the MB as a likely cause of the acute events. These cases, of unexplained acute coronary syndrome in low-risk patients, raise the question of alternative processes leading to the event and the role MB play as an underlying cause of ruptured plaques. In some cases, an active investigation for this entity may be warranted, due to the prognostic implications of the different therapeutic modalities, should an MB be discovered. PMID:28251167

  9. Myocardial Bridge and Acute Plaque Rupture.

    PubMed

    Perl, Leor; Daniels, David; Schwartz, Jonathan; Tanaka, Shige; Yeung, Alan; Tremmel, Jennifer A; Schnittger, Ingela

    2016-01-01

    A myocardial bridge (MB) is a common anatomic variant, most frequently located in the left anterior descending coronary artery, where a portion of the coronary artery is covered by myocardium. Importantly, MBs are known to result in a proximal atherosclerotic lesion. It has recently been postulated that these lesions predispose patients to acute coronary events, even in cases of otherwise low-risk patients. One such mechanism may involve acute plaque rupture. In this article, we report 2 cases of patients with MBs who presented with acute coronary syndromes despite having low cardiovascular risk. Their presentation was life-risking and both were treated urgently and studied with coronary angiographies and intravascular ultrasound. This latter modality confirmed a rupture of an atherosclerotic plaque proximal to the MB as a likely cause of the acute events. These cases, of unexplained acute coronary syndrome in low-risk patients, raise the question of alternative processes leading to the event and the role MB play as an underlying cause of ruptured plaques. In some cases, an active investigation for this entity may be warranted, due to the prognostic implications of the different therapeutic modalities, should an MB be discovered.

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

    PubMed

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

    2013-05-01

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

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

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

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

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

    PubMed

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

    2012-05-02

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

  13. B-cell-specific depletion of tumour necrosis factor alpha inhibits atherosclerosis development and plaque vulnerability to rupture by reducing cell death and inflammation.

    PubMed

    Tay, Christopher; Liu, Yu-Han; Hosseini, Hamid; Kanellakis, Peter; Cao, Anh; Peter, Karlheinz; Tipping, Peter; Bobik, Alex; Toh, Ban-Hock; Kyaw, Tin

    2016-09-01

    B2 lymphocytes promote atherosclerosis development but their mechanisms of action are unknown. Here, we investigated the role of tumour necrosis factor alpha (TNF-α) produced by B2 cells in atherogenesis. We found that 50% of TNF-α-producing spleen lymphocytes were B2 cells and ∼20% of spleen and aortic B cells produced TNF-α in hyperlipidemic ApoE(-/-) mice. We generated mixed bone marrow (80% μMT/20% TNF-α(-/-)) chimeric LDLR(-/-) mice where only B cells did not express TNF-α. Atherosclerosis was reduced in chimeric LDLR(-/-) mice with TNF-α-deficient B cells. TNF-α expression in atherosclerotic lesions and in macrophages were also reduced accompanied by fewer apoptotic cells, reduced necrotic cores, and reduced lesion Fas, interleukin-1β and MCP-1 in mice with TNF-α-deficient B cells compared to mice with TNF-α-sufficient B cells. To confirm that the reduced atherosclerosis is attributable to B2 cells, we transferred wild-type and TNF-α-deficient B2 cells into ApoE(-/-) mice deficient in B cells or in lymphocytes. After 8 weeks of high fat diet, we found that atherosclerosis was increased by wild-type but not TNF-α-deficient B2 cells. Lesions of mice with wild-type B2 cells but not TNF-α-deficient B2 cells also had increased apoptotic cells and necrotic cores. Transferred B2 cells were found in lesions of recipient mice, suggesting that TNF-α-producing B2 cells promote atherosclerosis within lesions. We conclude that TNF-α produced by B2 cells is a key mechanism by which B2 cells promote atherogenesis through augmenting macrophage TNF-α production to induce cell death and inflammation that promote plaque vulnerability. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

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

    PubMed Central

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

    2015-01-01

    Background: Oil pulling or oil swishing therapy is a traditional procedure in which the practitioners rinse or swish oil in their mouth. It is supposed to cure oral and systemic diseases but the evidence is minimal. Oil pulling with sesame oil and sunflower oil was found to reduce plaque related gingivitis. Coconut oil is an easily available edible oil. It is unique because it contains predominantly medium chain fatty acids of which 45-50 percent is lauric acid. Lauric acid has proven anti inflammatory and antimicrobial effects. No studies have been done on the benefits of oil pulling using coconut oil to date. So a pilot study was planned to assess the effect of coconut oil pulling on plaque induced gingivitis. Materials and Methods: The aim of the study was to evaluate the effect of coconut oil pulling/oil swishing on plaque formation and plaque induced gingivitis. A prospective interventional study was carried out. 60 age matched adolescent boys and girls in the age-group of 16-18 years with plaque induced gingivitis were included in the study and oil pulling was included in their oral hygiene routine. The study period was 30 days. Plaque and gingival indices of the subjects were assessed at baseline days 1,7,15 and 30. The data was analyzed using paired t test. Results: A statistically significant decrease in the plaque and gingival indices was noticed from day 7 and the scores continued to decrease during the period of study. Conclusion: Oil pulling using coconut oil could be an effective adjuvant procedure in decreasing plaque formation and plaque induced gingivitis. PMID:25838632

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

    PubMed Central

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

    2011-01-01

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

  16. Vulnerability of groundwater resources to nitrate pollution: A simple and effective procedure for delimiting Nitrate Vulnerable Zones.

    PubMed

    Arauzo, Mercedes

    2017-01-01

    This research was undertaken to further our understanding of the factors involved in nonpoint-source nitrate pollution of groundwater. The shortcomings of some of the most commonly used methods for assessing groundwater vulnerability have been analysed and a new procedure that incorporates key improvements has been proposed. The new approach (LU-IV procedure) allows us to assess and map groundwater vulnerability to nitrate pollution and to accurately delimit the Nitrate Vulnerable Zones. The LU-IV procedure proved more accurate than the most widely used methods to assess groundwater vulnerability (DRASTIC, GOD), when compared with nitrate distribution in the groundwater of 46 aquifers included in the study (using the drainage basin as the unit of analysis). The proposed procedure stands out by meeting the following requirements: (1) it uses readily available parameters that provide enough data to feed the model, (2) it excludes redundant parameters, (3) it avoids the need to assign insufficiently contrasted weights to parameters, (4) it assess the whole catchment area that potentially drains N-polluted waters into the receptor aquifer, (5) it can be implemented within a GIS, and (6) it provides a multi-scale representation. As the LU-IV procedure has been demonstrated to be a reliable tool for delimiting NVZ, it could be particularly interesting to use it in countries where certain types of environmental data are either not available or have only limited availability. Based on this study (and according to the LU-IV procedure), it was concluded that an area of at least 1728km 2 should be considered as NVZ. This sharply contrasts with the current 328km 2 officially designated in the study area by the Spain's regional administrations. These results highlight the need to redefine the current NVZ designation, which is essential for an appropriate implementation of action programmes designed to restore water quality in line with Directive 91/676/EEC. Copyright © 2016

  17. 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.

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

    PubMed

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

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

  19. Acid production in dental plaque after exposure to probiotic bacteria.

    PubMed

    Keller, Mette K; Twetman, Svante

    2012-10-24

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

  20. 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

    Atherosclerosis, a disease condition resulting from the buildup of fatty plaque deposits within arterial walls, is the major underlying cause of ischemia (restriction of the blood), leading to obstruction of peripheral arteries, congestive heart failure, heart attack, and stroke in humans. Emerging research indicates that factors including inflammation and infection may play a key role in the progression of atherosclerosis. In the current work, atherosclerotic carotid artery explants from 15 patients were all shown to test positive for the presence of eubacterial 16S rRNA genes. Density gradient gel electrophoresis of 5 of these samples revealed that each contained 10 or more distinct 16S rRNA gene sequences. Direct microscopic observation of transverse sections from 5 diseased carotid arteries analyzed with a eubacterium-specific peptide nucleic acid probe revealed these to have formed biofilm deposits, with from 1 to 6 deposits per thin section of plaque analyzed. A majority, 93%, of deposits was located proximal to the internal elastic lamina and associated with fibrous tissue. In 6 of the 15 plaques analyzed, 16S rRNA genes from Pseudomonas spp. were detected. Pseudomonas aeruginosa biofilms have been shown in our lab to undergo a dispersion response when challenged with free iron in vitro. Iron is known to be released into the blood by transferrin following interaction with catecholamine hormones, such as norepinephrine. Experiments performed in vitro showed that addition of physiologically relevant levels of norepinephrine induced dispersion of P. aeruginosa biofilms when grown under low iron conditions in the presence but not in the absence of physiological levels of transferrin. The association of bacteria with atherosclerosis has been only superficially studied, with little attention focused on the potential of bacteria to form biofilms within arterial plaques. In the current work, we show that bacteria form biofilm deposits within carotid arterial plaques

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

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

    Scammell, K.L.

    1987-01-01

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

  2. 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

  3. Association between Randall's Plaque and Calcifying Nanoparticles

    NASA Technical Reports Server (NTRS)

    Citfcioglu, Neva; Vejdani, Kaveh; Lee, Olivia; Mathew, Grace; Aho, Katja M.; Kajander, Olavi; McKay, David S.; Jones, Jeffrey A.; Feiveson, Alan H.; Stoller, Marshall L.

    2007-01-01

    Randall initially described calcified subepithelial papillary plaques, which he hypothesized as nidi for kidney stone formation. The discovery of calcifying nanoparticles (CNP) in many calcifying processes of human tissues has raised another hypothesis about their possible involvement in urinary stone formation. This research is the first attempt to investigate the potential association of these two hypotheses. We collected renal papilla and blood samples from 17 human patients who had undergone laparoscopic nephrectomy due to neoplasia. Immunohistochemical staining (IHS) was applied on the tissue samples using monoclonal antibody 8D10 (mAb) against CNP. Homogenized papillary tissues and serum samples were cultured for CNP. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis were performed on fixed papillary samples. Randall's plaques were visible on gross inspection in 11 out of 17 collected samples. IHS was positive for CNP antigen in 8 of these 11 visually positive samples, but in only 1 of the remaining 6 samples. SEM revealed spherical apatite formations in 14 samples, all of which had calcium and phosphate peaks detected by EDS analysis. From this study, there was some evidence of a link between the presence of Randall's plaques and the detection of CNP, also referred to as nanobacteria. Although causality was not demonstrated, these results suggest that further studies with negative control samples should be made to explore the etiology of Randall's plaque formation, thus leading to a better understanding of the pathogenesis of stone formation.

  4. 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.

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2016-05-01

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

  7. A simple and highly repeatable viral plaque assay for enterovirus 71.

    PubMed

    Yin, Yingxian; Xu, Yi; Ou, Zhiying; Su, Ling; Xia, Huimin

    2015-04-01

    The classic plaque assay is a method for counting infectious viral particles, however its complexity limits its use in a variety of virological experiments. To simplify the operation and to improve the repeatability, we employed an improved plaque assay procedure based on Avicel to make the whole experiment easier and optimize the results on a model of Vero cells infection with Enterovirus 71(EV71). Clear plaques visible to the naked eyes can be formed on a 24-well plate or a 96-well plate without immunostaining. Following further improvement, this plaque assay procedure could be applied to other viruses, being both simple and repeatable. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Differences in coronary plaque composition with aging measured by coronary computed tomography angiography.

    PubMed

    Tota-Maharaj, Rajesh; Blaha, Michael J; Rivera, Juan J; Henry, Travis S; Choi, Eue-Keun; Chang, Sung-A; Yoon, Yeonyee E; Chun, Eun Ju; Choi, Sang-Il; Blumenthal, Roger S; Chang, Hyuk-Jae; Nasir, Khurram

    2012-07-12

    Little is known about the independent impact of aging on coronary plaque morphology and composition in the era of cardiac computed tomography angiography (CCTA). We studied 1015 consecutive asymptomatic South Korean subjects (49 ± 10 years, 64% men) who underwent 64-slice CCTA during routine health evaluation. Coronary plaque characteristics were analyzed on a per-segment basis according to the modified AHA classification. Plaques with >50% calcified tissue were classified as calcified (CAP), plaques with <50% calcified tissue were classified as mixed (MCAP), and plaques without calcium were classified as non-calcified (NCAP). Multiple regression analysis was employed to describe the cross-sectional association between age tertile and plaque type burden (≥ 2 affected segments) after adjustment for other cardiovascular risk factors. The prevalence of coronary plaque increased with age, (1st tertile: 7.5%, 3rd tertile: 38.5% [p<0.001]). The relative contribution of NCAP to overall plaque burden decreased with age from nearly 50% in the first tertile to approximately 20% in the third, while there was a reciprocal increase in both MCAP and CAP subtypes. In multivariable analysis, patients in the oldest tertile had a 2.5-fold increase in burden of NCAP, yet a nearly 40-fold increase in MCAP and 16-fold increase in CAP compared to the youngest tertile. In conclusion, CCTA is an effective method for measuring age-related differences in the burden of individual coronary plaque subtypes. Future research is needed to determine whether the increase in mixed and calcified plaques seen with aging produce an independent contribution to the age-related increase in cardiovascular risk. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

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

    PubMed

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

    2001-08-01

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

  10. Motion Artifact Reduction in Ultrasound Based Thermal Strain Imaging of Atherosclerotic Plaques Using Time Series Analysis

    PubMed Central

    Dutta, Debaditya; Mahmoud, Ahmed M.; Leers, Steven A.; Kim, Kang

    2013-01-01

    Large lipid pools in vulnerable plaques, in principle, can be detected using US based thermal strain imaging (US-TSI). One practical challenge for in vivo cardiovascular application of US-TSI is that the thermal strain is masked by the mechanical strain caused by cardiac pulsation. ECG gating is a widely adopted method for cardiac motion compensation, but it is often susceptible to electrical and physiological noise. In this paper, we present an alternative time series analysis approach to separate thermal strain from the mechanical strain without using ECG. The performance and feasibility of the time-series analysis technique was tested via numerical simulation as well as in vitro water tank experiments using a vessel mimicking phantom and an excised human atherosclerotic artery where the cardiac pulsation is simulated by a pulsatile pump. PMID:24808628

  11. Influence of multi-cycle loading on the structure and mechanics of marine mussel plaques.

    PubMed

    Wilhelm, Menaka H; Filippidi, Emmanouela; Waite, J Herbert; Valentine, Megan T

    2017-10-18

    The proteinaceous byssal plaque-thread structures created by marine mussels exhibit extraordinary load-bearing capability. Although the nanoscopic protein interactions that support interfacial adhesion are increasingly understood, major mechanistic questions about how mussel plaques maintain toughness on supramolecular scales remain unanswered. This study explores the mechanical properties of whole mussel plaques subjected to repetitive loading cycles, with varied recovery times. Mechanical measurements were complemented with scanning electron microscopy to investigate strain-induced structural changes after yield. Multicyclic loading of plaques decreases their low-strain stiffness and introduces irreversible, strain-dependent plastic damage within the plaque microstructure. However, strain history does not compromise critical strength or maximum extension compared with plaques monotonically loaded to failure. These results suggest that a multiplicity of force transfer mechanisms between the thread and plaque-substrate interface allow the plaque-thread structure to accommodate a wide range of extensions as it continues to bear load. This improved understanding of the mussel system at micron-to-millimeter lengthscales offers strategies for including similar fail-safe mechanisms in the design of soft, tough and resilient synthetic structures.

  12. 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.

  13. Oral health practices and prevalence of dental plaque and gingivitis among Indian adults

    PubMed Central

    Prasad, K.V.V.; Javali, S. B.

    2016-01-01

    Abstract This cross‐sectional survey study evaluated oral hygiene habits in conjunction with whole mouth examinations for dental plaque and gingivitis among adults in India. Subjects across several age groups who provided informed consent [220 male and 158 female (mean age 30.9 years)] were enrolled. All enrolled subjects were interviewed for oral hygiene practices and evaluated by the Turesky modification of the Quigley‐Hein and the Löe‐Silness methods for dental plaque and gingivitis, respectively. Evaluations included oral hygiene parameters, prevalence of dental plaque and gingivitis, and regional differences within the dentition for dental plaque and gingivitis. Results from this study indicate that most subjects (97%) utilized a toothbrush and toothpaste for oral hygiene with a majority (92%) using their right hand to brush their teeth. While 29% reported two or more episodes of daily oral hygiene, a majority (53%) brushed their teeth once daily. Utilization of dental floss and mouthwashes were reported by approximately 1% of this population, and most (73%) reported no dental visits in the preceding 5 years. Whole mouth plaque and gingival scores (average ± standard deviation) for this population were 2.47 ± 0.55 and 1.19 ± 0.31, respectively, with no significant differences between either gender (P > 0.05). Significant correlations (r > 0.44) were observed between plaque and gingival scores for the entire sample, either gender or between age groups (P < 0.001). Analyses indicate that anterior teeth demonstrated lower average scores for dental plaque and gingivitis than posterior and molar regions (P < 0.05). Education was associated with higher plaque and gingival scores: plaque scores [odds ratios; 95% confidence interval; 1.23; 1.01–1.50 and gingival scores odds ratios 1.25; 1.02–1.54]. In summary, results from this study demonstrate the prevalence of dental plaque and gingivitis in the general population and their relationships with

  14. Prevalence and determinants of carotid plaque in the cross-sectional REFINE-Reykjavik study

    PubMed Central

    Sturlaugsdottir, Ran; Aspelund, Thor; Bjornsdottir, Gudlaug; Sigurdsson, Sigurdur; Thorsson, Bolli; Eiriksdottir, Gudny; Gudnason, Vilmundur

    2016-01-01

    Objective Carotid plaque and intima-media thickness are non-invasive arterial markers that are used as surrogate end points for cardiovascular disease. The aim was to assess the prevalence and severity of carotid plaque, and examine its determinant risk factors and their association to the common carotid artery intima-media thickness (CCA-IMT) in a general population. Methods We examined 6524 participants aged 25–69 years in the population-based REFINE (Risk Evaluation For INfarct Estimates)-Reykjavik study. Plaques at the bifurcation and internal carotid arteries were evaluated. Mean CCA-IMT was measured in the near and far walls of the common carotid arteries. Results The prevalence of minimal, moderate and severe plaque was 35.0%, 8.9% and 1.1%, respectively, and the mean CCA-IMT was 0.73 (SD 0.14) mm. Age, sex, smoking and type 2 diabetes mellitus (T2DM) were the strongest risk factors associated with plaque, followed by systolic blood pressure, total cholesterol, body mass index and family history of myocardial infarct. Low educational level was also strongly and independently associated with plaque. CCA-IMT shared the same risk factors except for a non-significant association with T2DM and family history of myocardial infarction (MI). Participants with T2DM had greater plaque prevalence, 2-fold higher in those <50 years and 17–30% greater in age groups 50–54 to 60–64, and more significant plaques (moderate or severe) were the difference in prevalence was 24% in age group 50–54 and ≥60% in older age groups, compared with non-T2DM. Conclusions Carotid plaque and CCA-IMT have mostly common determinants. However, T2DM and family history of MI were associated with plaque but not with CCA-IMT. Greater prevalence and more severe plaques in individuals with T2DM raise the concern that with increasing prevalence of T2DM we may expect an increase in atherosclerosis and its consequences. PMID:27884845

  15. Mechanisms of erosion of atherosclerotic plaques.

    PubMed

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

    2017-10-01

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

  16. Modified COMS Plaques for {sup 125}I and {sup 103}Pd Iris Melanoma Brachytherapy

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

    Thomson, Rowan M., E-mail: rthomson@physics.carleton.c; Furutani, Keith M.; Pulido, Jose S.

    2010-11-15

    Purpose: Novel plaques are used to treat iris melanoma at the Mayo Clinic Rochester. The plaques are a modification of the Collaborative Ocular Melanoma Study (COMS) 22 mm plaque design with a gold alloy backing, outer lip, and silicone polymer insert. An inner lip surrounds a 10 mm diameter cutout region at the plaque center. Plaques span 360{sup o}, 270{sup o}, and 180{sup o} arcs. This article describes dosimetry for these plaques and others used in the treatment of anterior eye melanomas. Methods and Materials: The EGSnrc user-code BrachyDose is used to perform Monte Carlo simulations. Plaques and seeds aremore » fully modeled. Three-dimensional dose distributions for different plaque models, TG-43 calculations, and {sup 125}I (model 6711) and {sup 103}Pd (model 200) seeds are compared via depth-dose curves, tabulation of doses at points of interest, and isodose contours. Results: Doses at points of interest differ by up to 70% from TG-43 calculations. The inner lip reduces corneal doses. Matching plaque arc length to tumor extent reduces doses to eye regions outside the treatment area. Maintaining the same prescription dose, {sup 103}Pd offers lower doses to critical structures than {sup 125}I, with the exception of the sclera adjacent to the plaque. Conclusion: The Mayo Clinic plaques offer several advantages for anterior eye tumor treatments. Doses to regions outside the treatment area are significantly reduced. Doses differ considerably from TG-43 predictions, illustrating the importance of complete Monte Carlo simulations. Calculations take a few minutes on a single CPU, making BrachyDose sufficiently fast for routine clinical treatment planning.« less

  17. Long-Term Marathon Running Is Associated with Low Coronary Plaque Formation in Women.

    PubMed

    Roberts, William O; Schwartz, Robert S; Kraus, Stacia Merkel; Schwartz, Jonathan G; Peichel, Gretchen; Garberich, Ross F; Lesser, John R; Oesterle, Stephen N; Wickstrom, Kelly K; Knickelbine, Thomas; Harris, Kevin M

    2017-04-01

    Marathon running is presumed to improve cardiovascular risk, but health benefits of high volume running are unknown. High-resolution coronary computed tomography angiography and cardiac risk factor assessment were completed in women with long-term marathon running histories to compare to sedentary women with similar risk factors. Women who had run at least one marathon per year for 10-25 yr underwent coronary computed tomography angiography, 12-lead ECG, blood pressure and heart rate measurement, lipid panel, and a demographic/health risk factor survey. Sedentary matched controls were derived from a contemporaneous clinical study database. CT scans were analyzed for calcified and noncalcified plaque prevalence, volume, stenosis severity, and calcium score. Women marathon runners (n = 26), age 42-82 yr, with combined 1217 marathons (average 47) exhibited significantly lower coronary plaque prevalence and less calcific plaque volume. The marathon runners also had less risk factors (smoking, hypertension, and hyperlipidemia); significantly lower resting heart rate, body weight, body mass index, and triglyceride levels; and higher high-density lipoprotein cholesterol levels compared with controls (n = 28). The five women runners with coronary plaque had run marathons for more years and were on average 12 yr older (65 vs 53) than the runners without plaque. Women marathon runners had minimal coronary artery calcium counts, lower coronary artery plaque prevalence, and less calcified plaque volume compared with sedentary women. Developing coronary artery plaque in long-term women marathon runners appears related to older age and more cardiac risk factors, although the runners with coronary artery plaque had accumulated significantly more years running marathons.

  18. 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.

  19. Vulnerability

    NASA Technical Reports Server (NTRS)

    Taback, I.

    1979-01-01

    The discussion of vulnerability begins with a description of some of the electrical characteristics of fibers before definiting how vulnerability calculations are done. The vulnerability results secured to date are presented. The discussion touches on post exposure vulnerability. After a description of some shock hazard work now underway, the discussion leads into a description of the planned effort and some preliminary conclusions are presented.

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

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

    Churg, A.; DePaoli, L.

    1988-07-01

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

  1. Diminished perisomatic GABAergic terminals on cortical neurons adjacent to amyloid plaques.

    PubMed

    Garcia-Marin, Virginia; Blazquez-Llorca, Lidia; Rodriguez, José-Rodrigo; Boluda, Susana; Muntane, Gerard; Ferrer, Isidro; Defelipe, Javier

    2009-01-01

    One of the main pathological hallmarks of Alzheimer's disease (AD) is the accumulation of plaques in the cerebral cortex, which may appear either in the neuropil or in direct association with neuronal somata. Since different axonal systems innervate the dendritic (mostly glutamatergic) and perisomatic (mostly GABAergic) regions of neurons, the accumulation of plaques in the neuropil or associated with the soma might produce different alterations to synaptic circuits. We have used a variety of conventional light, confocal and electron microscopy techniques to study their relationship with neuronal somata in the cerebral cortex from AD patients and APP/PS1 transgenic mice. The main finding was that the membrane surfaces of neurons (mainly pyramidal cells) in contact with plaques lack GABAergic perisomatic synapses. Since these perisomatic synapses are thought to exert a strong influence on the output of pyramidal cells, their loss may lead to the hyperactivity of the neurons in contact with plaques. These results suggest that plaques modify circuits in a more selective manner than previously thought.

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

    PubMed

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

    2018-05-01

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

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

    PubMed

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

    2009-01-01

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

  4. 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.

  5. Relating plaque morphology to respiratory syncytial virus subgroup, viral load, and disease severity in children.

    PubMed

    Kim, Young-In; Murphy, Ryan; Majumdar, Sirshendu; Harrison, Lisa G; Aitken, Jody; DeVincenzo, John P

    2015-10-01

    Viral culture plaque morphology in human cell lines are markers for growth capability and cytopathic effect, and have been used to assess viral fitness and select preattenuation candidates for live viral vaccines. We classified respiratory syncytial virus (RSV) plaque morphology and analyzed the relationship between plaque morphology as compared to subgroup, viral load and clinical severity of infection in infants and children. We obtained respiratory secretions from 149 RSV-infected children. Plaque morphology and viral load was assessed within the first culture passage in HEp-2 cells. Viral load was measured by polymerase chain reaction (PCR), as was RSV subgroup. Disease severity was determined by hospitalization, length of stay, intensive care requirement, and respiratory failure. Plaque morphology varied between individual subjects; however, similar results were observed among viruses collected from upper and lower respiratory tracts of the same subject. Significant differences in plaque morphology were observed between RSV subgroups. No correlations were found among plaque morphology and viral load. Plaque morphology did not correlate with disease severity. Plaque morphology measures parameters that are viral-specific and independent of the human host. Morphologies vary between patients and are related to RSV subgroup. In HEp-2 cells, RSV plaque morphology appears unrelated to disease severity in RSV-infected children.

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

    PubMed Central

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

    2013-01-01

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

  7. A Biological Tissue Adhesive and Dissolvent System for Intraocular Tumor Plaque Brachytherapy.

    PubMed

    Zloto, Ofira; Vishnevskia-Dai, Vicktoria; Moisseiev, Joseph; Belkin, Michael; Fabian, Ido Didi

    2016-02-01

    To examine a novel technique for simplified placement and removal of plaque brachytherapy by fibrin glue and urokinase (medac Gmbh, Hamburg, Germany). In six enucleated porcine eyes, plaques were placed on the episclera and fibrin glue was applied to cover it. Urokinase was used to dissolve the glue in three eyes and saline was used in three eyes. Adhesion strength was measured further on 15 plaques affixed to porcine eyes (glued in five with intact conjunctiva, glued in five with removed conjunctiva, and sutured in five). Saline had no effect on the glue-plaque-eye complex, whereas the urokinase (0.38 mL ± 0.08 mL) easily dissolved the adhesion between the glue layer and surrounding tissues. The weight required to detach the plaques was 0.349 kg ± 0.173 kg for glued eyes with intact conjunctiva, 0.405 kg ± 0.083 kg for sutured eyes (P = .59), and 0.032 kg ± 0.004 kg for glued eyes without intact conjunctiva (P ≤ .015). The usage of the biological adhesive and dissolvent system was applicable for plaque surgery in an ex vivo animal model. Copyright 2016, SLACK Incorporated.

  8. Effect of Bifidobacterium bifidum containing yoghurt on dental plaque bacteria in children.

    PubMed

    Caglar, Esber

    2014-01-01

    The aim of the present study is to determine the possible effect of Bifidobacterium bifidum DN-173 010 on dental plaque of children. 52 children (25 F and 27 M), between the ages of 8-10, participated in the present study. The study had a double blind, randomized crossover design and the experimental period consisted of four consecutive time periods. During periods 2 and 4 (2 weeks each), children consumed 110 g probiotic fruit yogurt (Bifidobacterium DN-173 010 (1 x 10(10) cfu/g)), or a placebo fruit yogurt per day. Available supragingival plaque (24 h later) was collected from teeth 16, 11, 36 and 31 at baseline and at the end of periods 2 and 4. The counts of dental plaque mutans streptococci (MS) were evaluated using Dentocult SM (Strep Mutans). Changes of pre- and post-treatment levels of dental plaque MS were recorded for four consecutive sampling sites. There were no statistically differences between transition scores of test and placebo groups regarding different dental plaque sampling sites (p > 0.05) (unpaired t-test). Within the limitations of the present study, Bifidobacterium bifidum DN-173 010 has no effect on dental plaque MS levels in children.

  9. 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.

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

    PubMed

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

    2018-04-01

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

  11. "Show me the money": vulnerability to gambling moderates the attractiveness of money versus suspense.

    PubMed

    Hahn, Cheryl; Wilson, Timothy D; McRae, Kaichen; Gilbert, Daniel T

    2013-10-01

    Do people take risks to obtain rewards or experience suspense? We hypothesized that people vulnerable to gambling are motivated more by the allure of winning money whereas people less vulnerable to gambling are motivated more by the allure of suspense. Consistent with this hypothesis, participants with high scores on a subscale of the Gambling Attitudes and Beliefs Survey--a measure of vulnerability to gambling--reported more of a motivation to earn money (pilot study), were more likely to accept a certain or near-certain amount of money than to gamble for that same amount (Studies 1-2), and worked harder to earn money (Study 3). People vulnerable to gambling also made more accurate predictions about how much they would gamble. People less vulnerable to gambling, in contrast, gambled more than people vulnerable to gambling, but did not know that they would.

  12. Acid production in dental plaque after exposure to probiotic bacteria

    PubMed Central

    2012-01-01

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

  13. 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

  14. Interstellar Message Plaques: Application of White-Light Holography

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    2002-01-01

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

  15. Effectiveness of a dental gel to reduce plaque in beagle dogs.

    PubMed

    Hennet, Philippe

    2002-03-01

    Tooth brushing is considered a superior technique for reducing plaque accumulation. Chemical agents may be used to reduce plaque accumulation on tooth surfaces since many owners may not be willing or able to brush their dog's teeth. Following a professional teeth cleaning procedure, a dental gel containing chlorhexidine was applied in 11 dogs BID for 7-days, while 11 other dogs received a control dental gel applied in the same manner. Dogs in the treatment group had significantly less plaque accumulation during the trial period compared with dogs in the control group. The dental gel applied in the study reported here decreases plaque accumulation in the short-term and may be beneficial in reducing the severity of gingivitis and associated periodontal disease if provided on a long-term basis.

  16. 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.

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

    PubMed

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

    2011-01-01

    To determine if baking soda toothpastes are relatively more effective than non-baking soda toothpastes in promoting plaque removal from less accessible sites in the dentition. Several single-brushing comparisons of baking soda and non-baking soda toothpastes for their overall ability to remove plaque have been published. In this study, individual comparisons of these published data, comparing the plaque removal performance of baking soda and non-baking soda toothpastes at various sites in the dentition, were examined to see if there were any site-dependant performance trends. The site-specific single-brushing data were then combined and analyzed in two ways. Meta-analyses of the clinical studies were performed to compare baking soda's relative plaque removal advantage at various sites in the mouth using paired t-testing at p <0.05. Also, plaque index reductions at various sites due to brushing with baking soda toothpastes were graphically compared with plaque index reductions due to brushing with non-baking soda dentifrices. The percent relative plaque removal advantage for baking soda toothpastes at various sites were plotted against the reduction in plaque index due to brushing with non-baking soda toothpastes. Individual comparisons showed that brushing with the toothpastes containing baking soda generally removed significantly more plaque from each site than brushing with toothpastes without baking soda. The relative efficacy advantage for baking soda toothpastes was consistently higher at sites where the non-baking soda toothpastes removed less plaque. Meta-analytical comparisons confirmed baking soda toothpastes to be relatively more effective in enhancing plaque removal from sites where less plaque was removed compared to brushing with non-baking soda toothpastes (p < 0.05). Graphically, the baking soda toothpastes' relative plaque removal advantage could be seen to increase hyperbolically with decreasing plaque removal by the non-baking soda toothpastes

  18. 19. View of dedication plaque on the north tower facing ...

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

    19. View of dedication plaque on the north tower facing south. The view is oblique because that portion of the approach trestles immediately in front of the plaque was removed in 1979. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  19. Plaque-Associated Local Toxicity Increases over the Clinical Course of Alzheimer Disease

    PubMed Central

    Serrano-Pozo, Alberto; Betensky, Rebecca A.; Frosch, Matthew P.; Hyman, Bradley T.

    2017-01-01

    Amyloid (senile) plaques, one of the two pathologic hallmarks of Alzheimer disease (AD), are associated with dystrophic neurites and glial responses, both astrocytic and microglial. Although plaque burden remains relatively stable through the clinical course of AD, whether these features of local plaque toxicity continue to worsen over the course of the disease is unclear. We performed an unbiased plaque-centered quantification of SMI312+ dystrophic neurites, GFAP+ reactive astrocytes, and IBA1+ and CD68+ activated microglia in randomly selected dense-core (Thioflavin-S+) plaques from the temporal neocortex of 40 AD subjects with a symptom duration ranging from 4 to 20 years, and nine nondemented control subjects with dense-core plaques. Dystrophic neurites (Kendall τ = 0.34, P = 0.001), reactive astrocytes (Kendall τ = 0.30, P = 0.003), and CD68+ (Kendall τ = 0.48, P < 0.0001), but not IBA1 microglia (Kendall τ = 0.045, P = 0.655), exhibited a significant positive correlation with symptom duration. When excluding control subjects, only the positive association between CD68+ microglia and symptom duration remained significant (Kendall τ = 0.39, P = 0.0003). The presence of the APOEε4 allele did not affect these results. We conclude that plaques exert an increasing toxicity in the surrounding neuropil over the clinical course of AD, thereby potentially contributing to cognitive decline. PMID:26687817

  20. Dose verification of eye plaque brachytherapy using spectroscopic dosimetry.

    PubMed

    Jarema, T; Cutajar, D; Weaver, M; Petasecca, M; Lerch, M; Kejda, A; Rosenfeld, A

    2016-09-01

    Eye plaque brachytherapy has been developed and refined for the last 80 years, demonstrating effective results in the treatment of ocular malignancies. Current dosimetry techniques for eye plaque brachytherapy (such as TLD- and film-based techniques) are time consuming and cannot be used prior to treatment in a sterile environment. The measurement of the expected dose distribution within the eye, prior to insertion within the clinical setting, would be advantageous, as any errors in source loading will lead to an erroneous dose distribution and inferior treatment outcomes. This study investigated the use of spectroscopic dosimetry techniques for real-time quality assurance of I-125 based eye plaques, immediately prior to insertion. A silicon detector based probe, operating in spectroscopy mode was constructed, containing a small (1 mm(3)) silicon detector, mounted within a ceramic holder, all encapsulated within a rubber sheath to prevent water infiltration of the electronics. Preliminary tests of the prototype demonstrated that the depth dose distribution through the central axis of an I-125 based eye plaque may be determined from AAPM Task Group 43 recommendations to a deviation of 6 % at 3 mm depth, 7 % at 5 mm depth, 1 % at 10 mm depth and 13 % at 20 mm depth, with the deviations attributed to the construction of the probe. A new probe design aims to reduce these discrepancies, however the concept of spectroscopic dosimetry shows great promise for use in eye plaque quality assurance in the clinical setting.

  1. Antiinflammatory actions of inorganic nitrate stabilize the atherosclerotic plaque

    PubMed Central

    Khambata, Rayomand S.; Ghosh, Suborno M.; Rathod, Krishnaraj S.; Thevathasan, Tharssana; Filomena, Federica; Xiao, Qingzhong; Ahluwalia, Amrita

    2017-01-01

    Reduced bioavailable nitric oxide (NO) plays a key role in the enhanced leukocyte recruitment reflective of systemic inflammation thought to precede and underlie atherosclerotic plaque formation and instability. Recent evidence demonstrates that inorganic nitrate (NO3−) through sequential chemical reduction in vivo provides a source of NO that exerts beneficial effects upon the cardiovascular system, including reductions in inflammatory responses. We tested whether the antiinflammatory effects of inorganic nitrate might prove useful in ameliorating atherosclerotic disease in Apolipoprotein (Apo)E knockout (KO) mice. We show that dietary nitrate treatment, although having no effect upon total plaque area, caused a reduction in macrophage accumulation and an elevation in smooth muscle accumulation within atherosclerotic plaques of ApoE KO mice, suggesting plaque stabilization. We also show that in nitrate-fed mice there is reduced systemic leukocyte rolling and adherence, circulating neutrophil numbers, neutrophil CD11b expression, and myeloperoxidase activity compared with wild-type littermates. Moreover, we show in both the ApoE KO mice and using an acute model of inflammation that this effect upon neutrophils results in consequent reductions in inflammatory monocyte expression that is associated with elevations of the antiinflammatory cytokine interleukin (IL)-10. In summary, we demonstrate that inorganic nitrate suppresses acute and chronic inflammation by targeting neutrophil recruitment and that this effect, at least in part, results in consequent reductions in the inflammatory status of atheromatous plaque, and suggest that this effect may have clinical utility in the prophylaxis of inflammatory atherosclerotic disease. PMID:28057862

  2. Efficacy of Methotrexate in patients with plaque type psoriasis

    PubMed Central

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

    2014-01-01

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

  3. Non-plaque-forming virions of Modified Vaccinia virus Ankara express viral genes.

    PubMed

    Lülf, Anna-Theresa; Freudenstein, Astrid; Marr, Lisa; Sutter, Gerd; Volz, Asisa

    2016-12-01

    In cell culture infections with vaccinia virus the number of counted virus particles is substantially higher than the number of plaques obtained by titration. We found that standard vaccine preparations of recombinant Modified Vaccinia virus Ankara produce only about 20-30% plaque-forming virions in fully permissive cell cultures. To evaluate the biological activity of the non-plaque-forming particles, we generated recombinant viruses expressing fluorescent reporter proteins under transcriptional control of specific viral early and late promoters. Live cell imaging and automated counting by fluorescent microscopy indicated that virtually all virus particles can enter cells and switch on viral gene expression. Although most of the non-plaque-forming infections are arrested at the level of viral early gene expression, we detected activation of late viral transcription in 10-20% of single infected cells. Thus, non-plaque-forming particles are biologically active, and likely contribute to the immunogenicity of vaccinia virus vaccines. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  5. Early improvement in carotid plaque echogenicity by acarbose in patients with acute coronary syndromes.

    PubMed

    Hirano, Mitsumasa; Nakamura, Takamitsu; Obata, Jyun-ei; Fujioka, Daisuke; Saito, Yukio; Kawabata, Ken-ichi; Watanabe, Kazuhiro; Watanabe, Yosuke; Kugiyama, Kiyotaka

    2012-01-01

    The resolution of hyperglycemia is associated with suppression of in-hospital cardiac complications in patients with acute coronary syndromes (ACS). This study evaluated carotid artery plaque echolucency using ultrasound in patients with ACS and type 2 diabetes mellitus (DM) to determine whether acarbose, an α-glucosidase inhibitor, may rapidly stabilize unstable atherosclerotic plaques. ACS patients with type 2 DM and carotid plaques (n=44) were randomly assigned to treatment with acarbose (150 or 300 mg/day, n=22) or a control group (no acarbose, n=22). Acarbose treatment was initiated within 5 days after the onset of ACS. Unstable carotid plaques were assessed by measuring plaque echolucency using carotid ultrasound with integrated backscatter (IBS) before, and at 2 weeks, 1 and 6 months after the initiation of treatment. An increase in the IBS value reflected an increase in carotid plaque echogenicity. As results, the IBS value of echolucent carotid plaques showed a significant increase at 1 month and a further increase at 6 months after treatment in the acarbose group, but there was minimal change in the control group. The increase in IBS values was significantly correlated with a decrease in C-reactive protein levels. Acarbose rapidly improved carotid plaque echolucency within 1 month of therapy in patients with ACS and type 2 DM.

  6. Measurement of traffic network vulnerability for Mississippi coastal region : final research report.

    DOT National Transportation Integrated Search

    2017-08-15

    Natural disasters such as a hurricane can cause great damages to the transportation networks and significantly affect the evacuation trip operations. An accurate understanding and measurement of the network vulnerability can enhance the evacuees p...

  7. HDL mimetic CER-001 targets atherosclerotic plaques in patients.

    PubMed

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

    2016-08-01

    Infusion of high-density lipoprotein (HDL) mimetics aimed at reducing atherosclerotic burden has led to equivocal results, which may relate in part to the inability of HDL mimetics to adequately reach atherosclerotic lesions in humans. This study evaluated delivery of recombinant human apolipoprotein A-I (apoA-I) containing HDL mimetic CER-001 in carotid plaques in patients. CER-001 was radiolabeled with the long-lived positron emitter zirconium-89 ((89)Zr) to enable positron emission tomography with computed tomography (PET/CT) imaging. Eight patients with atherosclerotic carotid artery disease (>50% stenosis) received a single infusion of unlabeled CER-001 (3 mg/kg), co-administered with 10 mg of (89)Zr-labeled CER-001 (18 MBq). Serial PET/CT imaging and contrast enhanced-magnetic resonance imaging (CE-MRI) were performed to evaluate targeted delivery of CER-001. One hour after infusion, mean plasma apoA-I levels increased by 9.9 mg/dL (p = 0.026), with a concomitant relative increase in the plasma cholesterol efflux capacity of 13.8% (p < 0.001). Using serial PET/CT imaging, we showed that arterial uptake of CER-001 expressed as target-to-background ratio (TBRmax) increased significantly 24 h after infusion, and remained increased up to 48 h (TBRmax t = 10 min: 0.98; t = 24 h: 1.14 (p = 0.001); t = 48 h: 1.12 (p = 0.007)). TBRmax was higher in plaque compared with non-plaque segments (1.18 vs. 1.05; p < 0.001). Plaque TBRmax correlated with local plaque contrast enhancement (r = 0.56; p = 0.019) as assessed by CE-MRI. Infusion of HDL mimetic CER-001 increases plasma apoA-I concentration and plasma cholesterol efflux capacity. Our data support the concept that CER-001 targets plaque regions in patients, which correlates with plaque contrast enhancement. These clinical findings may also guide future nanomedicine development using HDL particles for drug delivery in atherosclerosis. Netherlands Trial Registry - NTR5178. http

  8. 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

  9. A free boundary problem for steady small plaques in the artery and their stability

    NASA Astrophysics Data System (ADS)

    Friedman, Avner; Hao, Wenrui; Hu, Bei

    2015-08-01

    Atherosclerosis is a leading cause of death in the United States and worldwide; it originates from a plaque which builds up in the artery. In this paper, we consider a simplified model of plaque growth involving LDL and HDL cholesterols, macrophages and foam cells, which satisfy a coupled system of PDEs with a free boundary, the interface between the plaque and the blood flow. We prove that there exist small radially symmetric stationary plaques and establish a sharp condition that ensures their stability. We also determine necessary and sufficient conditions under which a small initial plaque will shrink and disappear, or persist for all times.

  10. Is the red fluorescence of dental plaque related to its cariogenicity?

    NASA Astrophysics Data System (ADS)

    Bittar, Daniela G.; Pontes, Laura Regina A.; Calvo, Ana Flávia B.; Novaes, Tatiane F.; Braga, Mariana M.; Freitas, Patrícia M.; Tabchoury, Cinthia P. M.; Mendes, Fausto M.

    2014-06-01

    It has been speculated that the red fluorescence emitted by dental plaque could be related to its cariogenicity. To test this hypothesis, we designed this crossover in situ study, with two experimental phases of 14 days each. Seventeen volunteers, wearing a palatal appliance with bovine enamel blocks, were instructed to drip a 20% sucrose solution (experimental group) or purified water (control group) onto the enamel blocks eight times daily. The specimens were removed after 4, 7, 10, and 14 days, and the red fluorescence of dental plaque formed on the enamel blocks was assessed using a quantitative light-induced fluorescence device. After the plaque removal, surface and cross-sectional microhardness tests were performed to assess the mineral loss. The comparisons were made by a multilevel linear regression analysis. We observed a significant increase in the red fluorescence of the dental plaque after longer periods of formation, but this trend was verified in both groups. The mineral loss assessed by the microhardness techniques, contrariwise, showed a significant increase only in the experimental group. In conclusion, the red fluorescence emitted by the dental plaque indicates a mature biofilm, but this fact is not necessarily associated with its cariogenicity.

  11. Role of Colgate Total toothpaste in helping control plaque and gingivitis.

    PubMed

    Rover, Jo-Ann; Leu-Wai-See, Petal

    2014-06-01

    To assess the anti-plaque and anti-gingivitis effects of a dentifrice containing 0.3% triclosan, 2% copolymer and 0.243% (1,100 ppm) sodium fluoride in subjects with moderate plaque-induced gingivitis. This was a single center, monadic study. Subjects had at least 20 teeth remaining in the functional dentition, excluding third molars. Following a baseline examination for plaque, gingival inflammation and bleeding, 75 qualified healthy adult males and females, ages 18-70 were selected to participate in the study. Dental prophylaxis was performed and subjects were provided with two tubes of toothpaste (Colgate Total) and a soft-bristle toothbrush (Colgate Wave Toothbrush). The subjects were instructed to brush twice daily using a modified Bass brushing technique. At the end of the 6- to 8-week period subjects returned for collection of clinical and subjective data. 75 subjects completed the study. Both clinical and subjective reductions were significant. The results showed statistically significant reductions in plaque index, gingival inflammation and bleeding on probing. The overall conclusion was that Colgate Total was a comprehensive dentifrice that produced a significant reduction in gingivitis, plaque, and bleeding.

  12. Mental Health Research in Correctional Settings: Perceptions of Risk and Vulnerabilities

    PubMed Central

    Johnson, Mark E.; Kondo, Karli K.; Brems, Christiane; Ironside, Erica F.; Eldridge, Gloria D.

    2015-01-01

    With over half of individuals incarcerated having serious mental health concerns, correctional settings offer excellent opportunities for epidemiological, prevention, and intervention research. However, due to unique ethical and structural challenges, these settings create risks and vulnerabilities for participants not typically encountered in research populations. We surveyed 1,224 researchers, IRB members, and IRB prisoner representatives to assess their perceptions of risks associated with mental health research conducted in correctional settings. Highest-ranked risks were related to privacy, stigma, and confidentiality; lowest-ranked risks were related to prisoners’ loss of privileges or becoming targets of violence due to having participated in research. Cognitive impairment, mental illness, lack of autonomy, and limited access to services emerged as the greatest sources of vulnerability; being male, being female, being over age of 60, being a minority, and being pregnant were the lowest-ranked sources of vulnerability. Researchers with corrections experience perceived lower risks and vulnerabilities than all other groups, raising the question whether these researchers accurately appraise risk and vulnerability based on experience, or if their lower risk and vulnerability perceptions reflect potential bias due to their vested interests. By identifying areas of particular risk and vulnerability, this study provides important information for researchers and research reviewers alike. PMID:27092025

  13. Genesis and growth of extracellular vesicle-derived microcalcification in atherosclerotic plaques

    PubMed Central

    Hutcheson, Joshua D.; Goettsch, Claudia; Bertazzo, Sergio; Maldonado, Natalia; Ruiz, Jessica L.; Goh, Wilson; Yabusaki, Katsumi; Faits, Tyler; Bouten, Carlijn; Franck, Gregory; Quillard, Thibaut; Libby, Peter; Aikawa, Masanori; Weinbaum, Sheldon; Aikawa, Elena

    2015-01-01

    Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification zones. We also show that calcification morphology and the plaque’s collagen content – two determinants of atherosclerotic plaque stability - are interlinked. PMID:26752654

  14. 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

  15. 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.

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

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

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

  17. Plaque assay for African swine fever virus on swine macrophages.

    PubMed

    Bustos, M J; Nogal, M L; Revilla, Y; Carrascosa, A L

    2002-07-01

    A plaque assay developed to detect the infection of African Swine Fever Virus on swine macrophages is described. Plaques were generated by all of the virus isolates tested. The method is suitable not only for virus titration but also for the selection of clones in protocols for isolation/purification of recombinant viruses.

  18. 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.

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-11-01

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

  1. Method of making a light weight battery plaque

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  2. Climate Change Impacts and Vulnerability Assessment in Industrial Complexes

    NASA Astrophysics Data System (ADS)

    Lee, H. J.; Lee, D. K.

    2016-12-01

    Climate change has recently caused frequent natural disasters, such as floods, droughts, and heat waves. Such disasters have also increased industrial damages. We must establish climate change adaptation policies to reduce the industrial damages. It is important to make accurate vulnerability assessment to establish climate change adaptation policies. Thus, this study aims at establishing a new index to assess vulnerability level in industrial complexes. Most vulnerability indices have been developed with subjective approaches, such as the Delphi survey and the Analytic Hierarchy Process(AHP). The subjective approaches rely on the knowledge of a few experts, which provokes the lack of the reliability of the indices. To alleviate the problem, we have designed a vulnerability index incorporating objective approaches. We have investigated 42 industrial complex sites in Republic of Korea (ROK). To calculate weights of variables, we used entropy method as an objective method integrating the Delphi survey as a subjective method. Finally, we found our method integrating both subjective method and objective method could generate result. The integration of the entropy method enables us to assess the vulnerability objectively. Our method will be useful to establish climate change adaptation policies by reducing the uncertainties of the methods based on the subjective approaches.

  3. I-125 ROPES eye plaque dosimetry: validation of a commercial 3D ophthalmic brachytherapy treatment planning system and independent dose calculation software with GafChromic® EBT3 films.

    PubMed

    Poder, Joel; Corde, Stéphanie

    2013-12-01

    The purpose of this study was to measure the dose distributions for different Radiation Oncology Physics and Engineering Services, Australia (ROPES) type eye plaques loaded with I-125 (model 6711) seeds using GafChromic(®) EBT3 films, in order to verify the dose distributions in the Plaque Simulator™ (PS) ophthalmic 3D treatment planning system. The brachytherapy module of RADCALC(®) was used to independently check the dose distributions calculated by PS. Correction factors were derived from the measured data to be used in PS to account for the effect of the stainless steel ROPES plaque backing on the 3D dose distribution. Using GafChromic(®) EBT3 films inserted in a specially designed Solid Water™ eye ball phantom, dose distributions were measured three-dimensionally both along and perpendicular to I-125 (model 6711) loaded ROPES eye plaque's central axis (CAX) with 2 mm depth increments. Each measurement was performed in full scatter conditions both with and without the stainless steel plaque backing attached to the eye plaque, to assess its effect on the dose distributions. Results were compared to the dose distributions calculated by Plaque Simulator™ and checked independently with RADCALC(®). The EBT3 film measurements without the stainless steel backing were found to agree with PS and RADCALC(®) to within 2% and 4%, respectively, on the plaque CAX. Also, RADCALC(®) was found to agree with PS to within 2%. The CAX depth doses measured using EBT3 film with the stainless steel backing were observed to result in a 4% decrease relative to when the backing was not present. Within experimental uncertainty, the 4% decrease was found to be constant with depth and independent of plaque size. Using a constant dose correction factor of T = 0.96 in PS, where the calculated dose for the full water scattering medium is reduced by 4% in every voxel in the dose grid, the effect of the plaque backing was accurately modeled in the planning system. Off-axis profiles

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

    PubMed

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

    2016-01-01

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

  5. Plaque the Apollo 14 crew will leave on the Moon

    NASA Image and Video Library

    1971-01-27

    S71-16637 (January 1971) --- A close-up view of the plaque which the Apollo 14 astronauts will leave behind on the moon during their lunar landing mission. Astronauts Alan B. Shepard Jr., commander, and Edgar D. Mitchell, lunar module pilot, will descend to the lunar surface in the Lunar Module (LM) "Antares". Astronaut Stuart A. Roosa, command module pilot, will remain with the Command and Service Modules (CSM) in lunar orbit. The seven by nine inch stainless steel plaque will be attached to the ladder on the landing gear strut on the LM's descent stage. Commemorative plaques were also left on the moon by the Apollo 11 and Apollo 12 astronauts.

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

    PubMed

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

    2015-09-01

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

  7. Mechanism of Enhancement of Virus Plaques by Cationic Polymers

    PubMed Central

    Wallis, Craig; Melnick, Joseph L.

    1968-01-01

    It has been assumed that plaque enhancement by cationic polymers is due to their binding of sulfated polysaccharides in agar. However, viruses that are enhanced by cationic polymers, diethylaminoethyl-dextran, and protamine were found not to be inhibited by polyanions in agar under the usual overlay conditions. In the case of adenovirus, enhancement by protamine seems to be due to the protamine serving as a source of arginine; enzymes released from the cultured cells digest the protamine and provide a reservoir of arginine for the cells. Other viruses (herpes and echovirus types 3, 4, 5, and 6) known to be susceptible to agar inhibitors were found to be enhanced by cationic polymers even under starch gel and methylcellulose overlays, which are free of polyanions. Since cationic polymers enhance the diffusion of virus through agar or starch gel, plaque enhancement seems to be the result of the gel becoming positively charged so that viruses can move effectively through them. The observation that starch gel and methylcellulose enhance plaque formation with viruses known to be inhibited under agar was also reinvestigated. When the consistency of the agar gel was reduced to the same viscosity of starch gel and methylcellulose overlays, the same plaque counts and sizes were observed under all three overlays. PMID:4986901

  8. Microbial profiling of dental plaque from mechanically ventilated patients

    PubMed Central

    Twigg, Joshua A.; Lewis, Michael A. O.; Wise, Matt P.; Marchesi, Julian R.; Smith, Ann; Wilson, Melanie J.; Williams, David W.

    2016-01-01

    Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97 % gene similarity cut-off for bacterial species level identifications. A significant ‘microbial shift’ occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection. PMID:26690690

  9. Microbial profiling of dental plaque from mechanically ventilated patients.

    PubMed

    Sands, Kirsty M; Twigg, Joshua A; Lewis, Michael A O; Wise, Matt P; Marchesi, Julian R; Smith, Ann; Wilson, Melanie J; Williams, David W

    2016-02-01

    Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97% gene similarity cut-off for bacterial species level identifications. A significant 'microbial shift' occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection.

  10. Testing the hypothesis of atherosclerotic plaque lipid depletion during lipid therapy by magnetic resonance imaging: study design of Carotid Plaque Composition Study.

    PubMed

    Zhao, Xue-Qiao; Phan, Binh An P; Chu, Baocheng; Bray, Frank; Moore, Andrew B; Polissar, Nayak L; Dodge, J Theodore; Lee, Colin D; Hatsukami, Thomas S; Yuan, Chun

    2007-08-01

    In vivo testing of the lipid depletion hypothesis in human beings during lipid-modifying therapy has not been possible until recent developments in magnetic resonance imaging (MRI). The Carotid Plaque Composition Study is a prospective, randomized study designed to test the lipid depletion hypothesis in vivo. One hundred twenty-three subjects with coronary artery disease (CAD) or carotid disease and with levels of apolipoprotein B > or = 120 mg/dL (low-density lipoprotein levels 100-190 mg/dL) were enrolled and randomized to (1) single therapy--atorvastatin alone, placebos for extended release (ER)-niacin and colesevelam; (2) double therapy--atorvastatin plus ER-niacin (2 g/d), and placebo for colesevelam; (3) triple therapy--atorvastatin, ER-niacin, plus colesevelam (3.8 g/d). All subjects will undergo MRI scans of bilateral carotid arteries at baseline and annually for 3 years for a total of 4 examinations while on active therapy. Among these 123 subjects with mean age of 55 years and mean body mass index of 30 kg/m2, 73% are male, 43% have a family history of premature cardiovascular disease, 37% have had a previous myocardial infarction, 80% have clinically established CAD, 52% are hypertensive, 12% have diabetes, 23% are current smokers, and 47% meet the criteria for metabolic syndrome. The baseline carotid disease is evaluated using a MRI-modified American Heart Association lesion type definition. Of the 123 enrolled subjects, 40% have type III lesions with small eccentric plaque, 52% have type IV to V lesions with a necrotic core, and only 4% have calcified plaque based on the most diseased carotid location. The Carotid Plaque Composition Study uses a state-of-the-art imaging technology and comprehensive lipid management to test the plaque lipid depletion hypothesis in CAD subjects.

  11. Using GA-Ridge regression to select hydro-geological parameters influencing groundwater pollution vulnerability.

    PubMed

    Ahn, Jae Joon; Kim, Young Min; Yoo, Keunje; Park, Joonhong; Oh, Kyong Joo

    2012-11-01

    For groundwater conservation and management, it is important to accurately assess groundwater pollution vulnerability. This study proposed an integrated model using ridge regression and a genetic algorithm (GA) to effectively select the major hydro-geological parameters influencing groundwater pollution vulnerability in an aquifer. The GA-Ridge regression method determined that depth to water, net recharge, topography, and the impact of vadose zone media were the hydro-geological parameters that influenced trichloroethene pollution vulnerability in a Korean aquifer. When using these selected hydro-geological parameters, the accuracy was improved for various statistical nonlinear and artificial intelligence (AI) techniques, such as multinomial logistic regression, decision trees, artificial neural networks, and case-based reasoning. These results provide a proof of concept that the GA-Ridge regression is effective at determining influential hydro-geological parameters for the pollution vulnerability of an aquifer, and in turn, improves the AI performance in assessing groundwater pollution vulnerability.

  12. An Evaluation of Plaque and Gingivitis Reduction Following Home Use of Sonicare FlexCare Platinum with Premium Plaque Control Brush Head and a Manual Toothbrush.

    PubMed

    Jenkins, Wendy; Souza, Sonia; Ward, Marilyn; Defenbaugh, Jodi; Milleman, Kimberly R; Milleman, Jeffery L

    2017-03-01

    To assess the effect of the Philips Sonicare FlexCare Platinum with Premium plaque control brush head on gingival inflammation, bleeding, and supragingival plaque reduction following a six-week period of home use compared to a manual toothbrush. This was a randomized, single-blind, parallel-design clinical trial. Subjects included in the study were routine manual toothbrush users who were generally healthy non-smokers, aged 18-65 years, with mild to moderate gingivitis. Subjects with advanced periodontal disease, excessive gingival recession, and heavy deposits of calculus or rampant decay were excluded from the study. Eligible participants were dispensed either Philips Sonicare FlexCare Platinum with Premium plaque control brush head (PC), or an ADA Reference manual toothbrush (MTB) for twice-daily home oral hygiene procedures for six weeks. Efficacy measures included the Lobene and Soparker Modification of Quigley and Hein Plaque Index (MPI), the Modified Gingival Index (MGI), and Gingival Bleeding Index (GBI). Safety was evaluated by oral examination and subject report. Efficacy and safety were assessed at Baseline, and at two and six weeks following product home use. Of 154 subjects randomized, 143 subjects completed the study. For the primary endpoint, MGI at Week 2, statistically significantly larger reductions in MGI were observed for PC versus MTB, p < 0.0001. The adjusted mean reduction and standard error estimates (SE) for MGI, expressed as percent reduction versus Baseline to Week 2, were 41.73% (2.00%) for PC and 7.38% (2.02%) for MTB. Statistically significant differences were also observed for MPI and GBI at Week 2, and for all metrics at Week 6. Philips Sonicare FlexCare Platinum with Premium plaque control brush head statistically significantly reduces gingival inflammation, gingival bleeding, and plaque following two and six weeks of home use, compared to manual tooth brushing alone.

  13. Evaluation of low molecular mass thiols content in carotid atherosclerotic plaques.

    PubMed

    Zinellu, Angelo; Lepedda, Antonio; Sotgia, Salvatore; Zinellu, Elisabetta; Scanu, Bastianina; Turrini, Franco; Spirito, Rita; Deiana, Luca; Formato, Marilena; Carru, Ciriaco

    2009-06-01

    Despite the evidence that both homocysteine and cysteine are important risk factors for vascular disease and atherosclerosis no information are reported about their effective amount in plaque and on the relationship with the other low molecular weight thiols. We used capillary electrophoresis to measure thiols in both carotid plaque specimens and plasma samples from 37 patients undergoing carotid endarterectomy. Pearson's correlation shows that intraplaque homocysteine, cysteine and cysteinylglycine levels are related to their plasma concentrations. The distribution of intraplaque GSH and Glu-Cys was higher than that of the same thiols in plasma, whereas the other thiols were significantly less prevalent in plaque than in plasma. Intraplaque haemoglobin and GSH levels were correlated, thus suggesting their common origin from erythrocytes lysis. Data suggest that increased levels of intraplaque glutathione may induce important effects on plaque fate by perturbing the normal LMW thiol redox state.

  14. Neutrophil Response to Dental Plaque by Gender and Race

    PubMed Central

    Wahaidi, V.Y.; Dowsett, S.A.; Eckert, G.J.; Kowolik, M.J.

    2009-01-01

    The inflammatory response, which has both genetic and environmental components, is a central mechanism linking oral and systemic diseases. We hypothesized that dental plaque accumulation over 21 days in the experimental gingivitis model would elicit systemic inflammatory responses [change in white blood cell (WBC) count and neutrophil activity], and that these responses would differ by gender/race. We recruited 156 healthy young adults, including black and white males and females. Plaque Index (PI), Gingival Index (GI), systemic WBC counts, and peripheral neutrophil oxidative activity were recorded. Overall, 128 participants completed the study. During the experimental phase, the correlation between PI and GI was 0.79. Total WBC and neutrophil counts did not change. Neutrophil activity increased in blacks but not whites, suggesting that there may be racial differences in the inflammatory response to dental plaque accumulation. PMID:19734456

  15. Biocompatibility of orthodontic bands following exposure to dental plaque.

    PubMed

    Hornikel, Sandra; Erbe, Christina; Schmidtmann, Irene; Wehrbein, Heiner

    2011-03-01

    The aim of this study was to assess the biocompatibility of orthodontic bands following exposure to the human oral environment. Cell adherence and cell morphology of gingival fibroblasts grown on 32 orthodontic bands were tested. The bands were in place intraorally for 6 to 37 months. We observed cell adherence in 76% of the previously plaque-free surfaces. Cell morphology was 50% spherical and 50% elongated. The surfaces that had had plaque attached demonstrated cell adherence in 84% of the given areas; those cells were spherical in 42% and elongated in 58%. We conclude that individual oral hygiene habits during orthodontic treatment seem to have no effect on the biocompatibility of orthodontic bands, as we failed to discern a difference in either cell adherence or cell morphology in areas with and without prior plaque attachment.

  16. Visualization of neuritic plaques in Alzheimer’s disease by polarization-sensitive optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Baumann, Bernhard; Woehrer, Adelheid; Ricken, Gerda; Augustin, Marco; Mitter, Christian; Pircher, Michael; Kovacs, Gabor G.; Hitzenberger, Christoph K.

    2017-03-01

    One major hallmark of Alzheimer’s disease (AD) and cerebral amyloid angiopathy (CAA) is the deposition of extracellular senile plaques and vessel wall deposits composed of amyloid-beta (Aβ). In AD, degeneration of neurons is preceded by the formation of Aβ plaques, which show different morphological forms. Most of them are birefringent owing to the parallel arrangement of amyloid fibrils. Here, we present polarization sensitive optical coherence microscopy (PS-OCM) for imaging mature neuritic Aβ plaques based on their birefringent properties. Formalin-fixed, post-mortem brain samples of advanced stage AD patients were investigated. In several cortical brain regions, neuritic Aβ plaques were successfully visualized in tomographic and three-dimensional (3D) images. Cortical grey matter appeared polarization preserving, whereas neuritic plaques caused increased phase retardation. Consistent with the results from PS-OCM imaging, the 3D structure of senile Aβ plaques was computationally modelled for different illumination settings and plaque sizes. Furthermore, the birefringent properties of cortical and meningeal vessel walls in CAA were investigated in selected samples. Significantly increased birefringence was found in smaller vessels. Overall, these results provide evidence that PS-OCM is able to assess amyloidosis based on intrinsic birefringent properties.

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

    NASA Technical Reports Server (NTRS)

    1971-01-01

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

  18. The antibacterial effect of photodynamic therapy in dental plaque-derived biofilms

    PubMed Central

    Fontana, C. R.; Abernethy, A. D.; Som, S.; Ruggiero, K.; Doucette, S.; Marcantonio, R. C.; Boussios, C. I.; Kent, R.; Goodson, J. M.; Tanner, A. C. R.; Soukos, N. S.

    2009-01-01

    Background and Objective Photodynamic therapy (PDT) has been advocated as an alternative to antimicrobial agents to suppress subgingival species and treat periodontitis. Bacteria located within dense biofilms, such as those encountered in dental plaques, have been found to be relatively resistant to antimicrobial therapy. In the present study, we investigated the ability of PDT to affect bacteria resistant in biofilms by comparing the photodynamic effects of methylene blue (MB) on human dental plaque microorganisms in planktonic phase and in biofilms. Material and Methods Dental plaque samples were obtained from 10 subjects with chronic periodontitis. Suspensions of plaque microorganisms from 5 subjects were sensitized with MB (25 μg/ml) for 5 minutes followed by exposure to red light. Multi-species microbial biofilms developed from the same plaque samples were also exposed to MB (25 μg/ml) and the same light conditions as their planktonic counterparts. In a second set of experiments, biofilms were developed with plaque bacteria from 5 subjects and sensitized with 25 and 50 μg/ml MB followed by exposure to light as above. After PDT, survival fractions were calculated from colony-forming unit counts. Results In suspension, PDT produced approximately 63% killing of bacteria. In biofilms, the effect of PDT resulted in much lower reductions of microorganisms (32% maximal killing). Conclusion Oral bacteria in biofilms are less affected by PDT than bacteria in planktonic phase. The antibacterial effect of PDT is reduced in biofilm bacteria but not to the same degree as has been reported for treatment with antibiotics under similar conditions. PMID:19602126

  19. 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

  20. 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.

  1. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

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

    Lesperance, Marielle; Inglis-Whalen, M.; Thomson, R. M., E-mail: rthomson@physics.carleton.ca

    model simulation by up to 16%. In the full eye model simulations, the average dose to the lens is larger by 7%–9% than the dose to the center of the lens, and the maximum dose to the optic nerve is 17%–22% higher than the dose to the optic disk for all radionuclides. In general, when normalized to the same prescription dose at the tumor apex, doses delivered to all structures of interest in the full eye model are lowest for{sup 103}Pd and highest for {sup 131}Cs, except for the tumor where the average dose is highest for {sup 103}Pd and lowest for {sup 131}Cs. Conclusions : The eye is not radiologically water-equivalent, as doses from simulations of the plaque in the full eye model differ considerably from doses for the plaque in a water phantom and from simulated TG-43 calculated doses. This demonstrates the importance of model-based dose calculations for eye plaque brachytherapy, for which accurate elemental compositions of ocular media are necessary.« less

  2. Calibration of groundwater vulnerability mapping using the generalized reduced gradient method

    NASA Astrophysics Data System (ADS)

    Elçi, Alper

    2017-12-01

    Groundwater vulnerability assessment studies are essential in water resources management. Overlay-and-index methods such as DRASTIC are widely used for mapping of groundwater vulnerability, however, these methods mainly suffer from a subjective selection of model parameters. The objective of this study is to introduce a calibration procedure that results in a more accurate assessment of groundwater vulnerability. The improvement of the assessment is formulated as a parameter optimization problem using an objective function that is based on the correlation between actual groundwater contamination and vulnerability index values. The non-linear optimization problem is solved with the generalized-reduced-gradient (GRG) method, which is numerical algorithm based optimization method. To demonstrate the applicability of the procedure, a vulnerability map for the Tahtali stream basin is calibrated using nitrate concentration data. The calibration procedure is easy to implement and aims the maximization of correlation between observed pollutant concentrations and groundwater vulnerability index values. The influence of each vulnerability parameter in the calculation of the vulnerability index is assessed by performing a single-parameter sensitivity analysis. Results of the sensitivity analysis show that all factors are effective on the final vulnerability index. Calibration of the vulnerability map improves the correlation between index values and measured nitrate concentrations by 19%. The regression coefficient increases from 0.280 to 0.485. It is evident that the spatial distribution and the proportions of vulnerability class areas are significantly altered with the calibration process. Although the applicability of the calibration method is demonstrated on the DRASTIC model, the applicability of the approach is not specific to a certain model and can also be easily applied to other overlay-and-index methods.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  4. Cetylpyridinium chloride mouth rinses alleviate experimental gingivitis by inhibiting dental plaque maturation.

    PubMed

    Teng, Fei; He, Tao; Huang, Shi; Bo, Cun-Pei; Li, Zhen; Chang, Jin-Lan; Liu, Ji-Quan; Charbonneau, Duane; Xu, Jian; Li, Rui; Ling, Jun-Qi

    2016-09-29

    Oral rinses containing chemotherapeutic agents, such as cetylpyridinium chloride (CPC), can alleviate plaque-induced gingival infections, but how oral microbiota respond to these treatments in human population remains poorly understood. Via a double-blinded, randomised controlled trial of 91 subjects, the impact of CPC-containing oral rinses on supragingival plaque was investigated in experimental gingivitis, where the subjects, after a 21-day period of dental prophylaxis to achieve healthy gingivae, received either CPC rinses or water for 21 days. Within-subject temporal dynamics of plaque microbiota and symptoms of gingivitis were profiled via 16S ribosomal DNA gene pyrosequencing and assessment with the Mazza gingival index. Cetylpyridinium chloride conferred gingival benefits, as progression of gingival inflammation resulting from a lack of dental hygiene was significantly slower in the mouth rinse group than in the water group due to inhibition of 17 gingivitis-enriched bacterial genera. Tracking of plaque α and β diversity revealed that CPC treatment prevents acquisition of new taxa that would otherwise accumulate but maintains the original biodiversity of healthy plaques. Furthermore, CPC rinses reduced the size, local connectivity and microbiota-wide connectivity of the bacterial correlation network, particularly for nodes representing gingivitis-enriched taxa. The findings of this study provide mechanistic insights into the impact of oral rinses on the progression and maturation of dental plaque in the natural human population.

  5. Cetylpyridinium chloride mouth rinses alleviate experimental gingivitis by inhibiting dental plaque maturation

    PubMed Central

    Teng, Fei; He, Tao; Huang, Shi; Bo, Cun-Pei; Li, Zhen; Chang, Jin-Lan; Liu, Ji-Quan; Charbonneau, Duane; Xu, Jian; Li, Rui; Ling, Jun-Qi

    2016-01-01

    Oral rinses containing chemotherapeutic agents, such as cetylpyridinium chloride (CPC), can alleviate plaque-induced gingival infections, but how oral microbiota respond to these treatments in human population remains poorly understood. Via a double-blinded, randomised controlled trial of 91 subjects, the impact of CPC-containing oral rinses on supragingival plaque was investigated in experimental gingivitis, where the subjects, after a 21-day period of dental prophylaxis to achieve healthy gingivae, received either CPC rinses or water for 21 days. Within-subject temporal dynamics of plaque microbiota and symptoms of gingivitis were profiled via 16S ribosomal DNA gene pyrosequencing and assessment with the Mazza gingival index. Cetylpyridinium chloride conferred gingival benefits, as progression of gingival inflammation resulting from a lack of dental hygiene was significantly slower in the mouth rinse group than in the water group due to inhibition of 17 gingivitis-enriched bacterial genera. Tracking of plaque α and β diversity revealed that CPC treatment prevents acquisition of new taxa that would otherwise accumulate but maintains the original biodiversity of healthy plaques. Furthermore, CPC rinses reduced the size, local connectivity and microbiota-wide connectivity of the bacterial correlation network, particularly for nodes representing gingivitis-enriched taxa. The findings of this study provide mechanistic insights into the impact of oral rinses on the progression and maturation of dental plaque in the natural human population. PMID:27680288

  6. 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.

  7. Connexin Type and Fluorescent Protein Fusion Tag Determine Structural Stability of Gap Junction Plaques.

    PubMed

    Stout, Randy F; Snapp, Erik Lee; Spray, David C

    2015-09-25

    Gap junctions (GJs) are made up of plaques of laterally clustered intercellular channels and the membranes in which the channels are embedded. Arrangement of channels within a plaque determines subcellular distribution of connexin binding partners and sites of intercellular signaling. Here, we report the discovery that some connexin types form plaque structures with strikingly different degrees of fluidity in the arrangement of the GJ channel subcomponents of the GJ plaque. We uncovered this property of GJs by applying fluorescence recovery after photobleaching to GJs formed from connexins fused with fluorescent protein tags. We found that connexin 26 (Cx26) and Cx30 GJs readily diffuse within the plaque structures, whereas Cx43 GJs remain persistently immobile for more than 2 min after bleaching. The cytoplasmic C terminus of Cx43 was required for stability of Cx43 plaque arrangement. We provide evidence that these qualitative differences in GJ arrangement stability reflect endogenous characteristics, with the caveat that the sizes of the GJs examined were necessarily large for these measurements. We also uncovered an unrecognized effect of non-monomerized fluorescent protein on the dynamically arranged GJs and the organization of plaques composed of multiple connexin types. Together, these findings redefine our understanding of the GJ plaque structure and should be considered in future studies using fluorescent protein tags to probe dynamics of highly ordered protein complexes. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. 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

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

    PubMed Central

    Kastrup, Christian J.; Nahrendorf, Matthias; Figueiredo, Jose Luiz; Lee, Haeshin; Kambhampati, Swetha; Lee, Timothy; Cho, Seung-Woo; Gorbatov, Rostic; Iwamoto, Yoshiko; Dang, Tram T.; Dutta, Partha; Yeon, Ju Hun; Cheng, Hao; Pritchard, Christopher D.; Vegas, Arturo J.; Siegel, Cory D.; MacDougall, Samantha; Okonkwo, Michael; Thai, Anh; Stone, James R.; Coury, Arthur J.; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G.

    2012-01-01

    The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques. PMID:23236189

  10. 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.

  11. A uni-extension study on the ultimate material strength and extreme extensibility of atherosclerotic tissue in human carotid plaques.

    PubMed

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

    2015-11-05

    Atherosclerotic plaque rupture occurs when mechanical loading exceeds its material strength. Mechanical analysis has been shown to be complementary to the morphology and composition for assessing vulnerability. However, strength and stretch thresholds for mechanics-based assessment are currently lacking. This study aims to quantify the ultimate material strength and extreme extensibility of atherosclerotic components from human carotid plaques. Tissue strips of fibrous cap, media, lipid core and intraplaque hemorrhage/thrombus were obtained from 21 carotid endarterectomy samples of symptomatic patients. Uni-extension test with tissue strips was performed until they broke or slid. The Cauchy stress and stretch ratio at the peak loading of strips broken about 2mm away from the clamp were used to characterize their ultimate strength and extensibility. Results obtained indicated that ultimate strength of fibrous cap and media were 158.3 [72.1, 259.3] kPa (Median [Inter quartile range]) and 247.6 [169.0, 419.9] kPa, respectively; those of lipid and intraplaque hemorrhage/thrombus were 68.8 [48.5, 86.6] kPa and 83.0 [52.1, 124.9] kPa, respectively. The extensibility of each tissue type were: fibrous cap - 1.18 [1.10, 1.27]; media - 1.21 [1.17, 1.32]; lipid - 1.25 [1.11, 1.30] and intraplaque hemorrhage/thrombus - 1.20 [1.17, 1.44]. Overall, the strength of fibrous cap and media were comparable and so were lipid and intraplaque hemorrhage/thrombus. Both fibrous cap and media were significantly stronger than either lipid or intraplaque hemorrhage/thrombus. All atherosclerotic components had similar extensibility. Moreover, fibrous cap strength in the proximal region (closer to the heart) was lower than that of the distal. These results are helpful in understanding the material behavior of atherosclerotic plaques. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. 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.

  13. Chair-side detection of Prevotella Intermedia in mature dental plaque by its fluorescence.

    PubMed

    Nomura, Yoshiaki; Takeuchi, Hiroaki; Okamoto, Masaaki; Sogabe, Kaoru; Okada, Ayako; Hanada, Nobuhiro

    2017-06-01

    Prevotella intermedia/nigrescens is one of the well-known pathogens causing periodontal diseases, and the red florescence excited by the visible blue light caused by the protoporphyrin IX in the bacterial cells could be useful for the chair-side detection. The aim of this study was to evaluated levels of periodontal pathogen, especially P. intermedia in clinical samples of red fluorescent dental plaque. Thirty two supra gingival plaque samples from six individuals were measured its fluorescence at 640nm wavelength excited by 409nm. Periodontopathic bacteria were counted by the Invader PLUS PCR assay. Co-relations the fluorescence intensity and bacterial counts were analyzed by Person's correlation coefficient and simple and multiple regression analysis. Positive and negative predictive values of the fluorescence intensities for with or without P. intermedia in supragingival plaque was calculated. When relative fluorescence unit (RFU) were logarithmic transformed, statistically significant linear relations between RFU and bacterial counts were obtained for P. intermedia, Porphyromonas gingivalis and Tannerella forsythia. By the multiple regression analysis, only P. intermedia had statistically significant co-relation with fluorescence intensities. All of the fluorescent dental plaque contained P. intermedia m. In contrast, 28% of non-fluorescent plaques contained P. intermedia. To check the fluorescence dental plaque in the oral cavity could be the simple chair-side screening of the mature dental plaque before examining the periodontal pathogens especially P. intermedia by the PCR method. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Recent Advances in Fluorescent Angioscopy for Molecular Imaging of Human Atherosclerotic Coronary Plaque

    PubMed Central

    2017-01-01

    Purpose of Review: In vivo imaging of the native substances, including lipoproteins, that comprise human atherosclerotic plaques is currently beyond the scope of any available imaging techniques. Color and near-infrared fluorescent angioscopy (CFA and NIRFA, respectively) systems have been recently developed for molecular imaging of lipoproteins within the human coronary arterial wall ex vivo and/or in vivo. The author reviews recent findings on lipoprotein deposition in human coronary plaques obtained by these imaging techniques. Recent Findings: Using specific biomarkers, native pro-atherogenic substances such as oxidized low-density lipoprotein (ox-LDL), LDL, triglycerides (TG), apolipoprotein B-100 (ApoB-100), and lysophosphatidylcholine (LPC), and the anti-atherogenic substance such as high-density lipoprotein (HDL) were visualized by CFA, and LDL and cholesterol by NIRFA, in coronary plaques obtained from autopsy subjects. The relationship between incidence and plaque morphology differed for each substance. The incidence of ox-LDL and LDL on color fluorescence microscopy correlated well with that observed using immunohistochemical techniques. During coronary catheterization in patients, ox-LDL, LDL, and HDL in coronary plaques were visualized by CFA or NIRFA. Conclusions: Using CFA or NIRFA, the distribution of the major native pro-atherogenic and antiatherogenic lipoproteins and their components within human coronary plaques can be evaluated ex vivo and/or in vivo. Fluorescent angioscopy could help our understanding of the molecular mechanisms of coronary atherosclerosis and in the evaluation of the effects of therapy targeting the substances comprising atherosclerotic coronary plaques. PMID:28381766

  15. A method for the quantitative site-specific study of the biochemistry within dental plaque biofilms formed in vivo.

    PubMed

    Robinson, C; Kirkham, J; Percival, R; Shore, R C; Bonass, W A; Brookes, S J; Kusa, L; Nakagaki, H; Kato, K; Nattress, B

    1997-01-01

    The study of plaque biofilms in the oral cavity is difficult as plaque removal inevitably disrupts biofilm integrity precluding kinetic studies involving the penetration of components and metabolism of substrates in situ. A method is described here in which plaque is formed in vivo under normal (or experimental) conditions using a collection device which can be removed from the mouth after a specified time without physical disturbance to the plaque biofilm, permitting site-specific analysis or exposure of the undisturbed plaque to experimental conditions in vitro. Microbiological analysis revealed plaque flora which was similar to that reported from many natural sources. Analytical data can be related to plaque volume rather than weight. Using this device, plaque fluoride concentrations have been shown to vary with plaque depth and in vitro short-term exposure to radiolabelled components may be carried out, permitting important conclusions to be drawn regarding the site-specific composition and dynamics of dental plaque.

  16. Stepping inside the niche: microclimate data are critical for accurate assessment of species' vulnerability to climate change

    PubMed Central

    Storlie, Collin; Merino-Viteri, Andres; Phillips, Ben; VanDerWal, Jeremy; Welbergen, Justin; Williams, Stephen

    2014-01-01

    To assess a species' vulnerability to climate change, we commonly use mapped environmental data that are coarsely resolved in time and space. Coarsely resolved temperature data are typically inaccurate at predicting temperatures in microhabitats used by an organism and may also exhibit spatial bias in topographically complex areas. One consequence of these inaccuracies is that coarsely resolved layers may predict thermal regimes at a site that exceed species' known thermal limits. In this study, we use statistical downscaling to account for environmental factors and develop high-resolution estimates of daily maximum temperatures for a 36 000 km2 study area over a 38-year period. We then demonstrate that this statistical downscaling provides temperature estimates that consistently place focal species within their fundamental thermal niche, whereas coarsely resolved layers do not. Our results highlight the need for incorporation of fine-scale weather data into species' vulnerability analyses and demonstrate that a statistical downscaling approach can yield biologically relevant estimates of thermal regimes. PMID:25252835

  17. Association of caries experience and dental plaque with sociodemographic characteristics in elementary school-aged children: a cross-sectional study.

    PubMed

    Bashirian, Saeed; Shirahmadi, Samaneh; Seyedzadeh-Sabounchi, Shabnam; Soltanian, Ali Reza; Karimi-Shahanjarini, Akram; Vahdatinia, Farshid

    2018-01-10

    and plaque formation among elementary school children in Hamadan were high and they were influenced by their sociodemographic factors. The associations found can be used as a helpful guide for planning accurate preventive programs for elementary school children in this region.

  18. 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.

  19. 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

  20. Determination of multiple sclerosis plaque size with diffusion-tensor MR Imaging: comparison study with healthy volunteers.

    PubMed

    Kealey, Susan M; Kim, Youngjoo; Whiting, Wythe L; Madden, David J; Provenzale, James M

    2005-08-01

    To use diffusion-tensor magnetic resonance (MR) imaging to measure involvement of normal-appearing white matter (WM) immediately adjacent to multiple sclerosis (MS) plaques and thus redefine actual plaque size on diffusion-tensor images through comparison with T2-weighted images of equivalent areas in healthy volunteers. Informed consent was not required given the retrospective nature of the study on an anonymized database. The study complied with requirements of the Health Insurance Portability and Accountability Act. Twelve patients with MS (four men, eight women; mean age, 35 years) and 14 healthy volunteers (six men, eight women; mean age, 25 years) were studied. The authors obtained fractional anisotropy (FA) values in MS plaques and in the adjacent normal-appearing WM in patients with MS and in equivalent areas in healthy volunteers. They placed regions of interest (ROIs) around the periphery of plaques and defined the total ROIs (ie, plaques plus peripheral ROIs) as abnormal if their mean FA values were at least 2 standard deviations below those of equivalent ROIs within equivalent regions in healthy volunteers. The combined area of the plaque and the peripheral ROI was compared with the area of the plaque seen on T2-weighted MR images by means of a Student paired t test (P = .05). The mean plaque size on T2-weighted images was 72 mm2 +/- 21 (standard deviation). The mean plaque FA value was 0.285 +/- 0.088 (0.447 +/- 0.069 in healthy volunteers [P < .001]; mean percentage reduction in FA in MS plaques, 37%). The mean plaque size on FA maps was 91 mm2 +/- 35, a mean increase of 127% compared with the size of the original plaque on T2-weighted images (P = .03). A significant increase in plaque size was seen when normal-appearing WM was interrogated with diffusion-tensor MR imaging. This imaging technique may represent a more sensitive method of assessing disease burden and may have a future role in determining disease burden and activity.

  1. [Influence of the fluoride releasing dental materials on the bacterial flora of dental plaque].

    PubMed

    Płuciennik, Małgorzata; Sakowska, Danuta; Krzemiński, Zbigniew; Piatowska, Danuta

    2008-01-01

    The assessment of influence of silver-free, fluor releasing dental materials on dental plaque bacteria quantity. 17 patients were included into the study. 51 restorations were placed following manufacturers recommendations. Following materials were used: conventional glassionomer Ketac-Molar ESPE, resin modified glassionomer Fuji II LC GC and fluor containing composite Charisma Heraeus Kulzer Class V restorations were placed in following teeth of upper and lower jaw: canines, first bicuspids, second bicuspids. Sound enamel was a control. After 10 weeks the 72 hours old dental plaque was collected from surface of restorations and control using sterile probe. Total amount of 68 dental plaques were investigated. Each plaque was placed on scaled and sterile aluminum foil. The moist weight of dental plaque was scaled. Dental plaque was moved into 7 ml 0.85% NaCl solution reduced by cystein chlorine hydrogen and disintegrated by ultrasounds (power:100 Watt, wave amplitude: 5 micorm). The suspension of dental plaque was serially diluted from 10(-4) to 10(-5) in sterile 0,85% NaCl solution, and seeded with amount of 0.1 ml on appropriate base. In dental plaque trials the amount of cariogenic bacteria was calculated--Streptococcus mutans, Streptococcus, Lactobacillus, Veillonella and Neisseria, and also total amount of aerobic and anaerobic bacteria was measured. Microbiologic studies were performed in Institute of Microbiology, Medical University, Łódź. Statistical analysis of collected data was accomplished. In 72 hours old dental plaques collected from the surfaces of Ketac -Molar, Fuji II LC, Charisma after 10 weeks since being placed into the class V cavity, results show no statistically significant differences in the amount of Streptococcus mutans, Streptococcus spp., Lactobacillus spp., Veillonella spp., Neisseria spp, in total amount of aerobic and anaerobic bacteria and in the quantity proportion of Streptococcus mutans versus Streptococcus spp. in comparison

  2. OCT-measured plaque free wall angle is indicative for plaque burden: overcoming the main limitation of OCT?

    PubMed

    Hoogendoorn, Ayla; Gnanadesigan, Muthukaruppan; Zahnd, Guillaume; van Ditzhuijzen, Nienke S; Schuurbiers, Johan C H; van Soest, Gijs; Regar, Evelyn; Wentzel, Jolanda J

    2016-10-01

    The aim of this study was to investigate the relationship between the plaque free wall (PFW) measured by optical coherence tomography (OCT) and the plaque burden (PB) measured by intravascular ultrasound (IVUS). We hypothesize that measurement of the PFW could help to estimate the PB, thereby overcoming the limited ability of OCT to visualize the external elastic membrane in the presence of plaque. This could enable selection of the optimal stent-landing zone by OCT, which is traditionally defined by IVUS as a region with a PB < 40 %. PB (IVUS) and PFW angle (OCT and IVUS) were measured in 18 matched IVUS and OCT pullbacks acquired in the same coronary artery. We determined the relationship between OCT measured PFW (PFWOCT) and IVUS PB (PBIVUS) by non-linear regression analysis. An ROC-curve analysis was used to determine the optimal cut-off value of PFW angle for the detection of PB < 40 %. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. There is a significant correlation between PFWOCT and PBIVUS (r(2) = 0.59). The optimal cut-off value of the PFWOCT for the prediction of a PBIVUS < 40 % is ≥220° with a PPV of 78 % and an NPV of 84 %. This study shows that PFWOCT can be considered as a surrogate marker for PBIVUS, which is currently a common criterion to select an optimal stent-landing zone.

  3. Expedition 54 plaque hanging ceremony

    NASA Image and Video Library

    2018-04-26

    NASA astronauts Joe Acaba and Mark Vande Hei Acaba visited Marshall April 11 for their honorary Expedition 54 plaque hanging ceremony and to provide valuable feedback of their on-orbit science investigations with the Payload Operations and Integration Center team. Astronauts Mark Vande Hei (L) and Astronaut Joe Acaba sign autographs for Kassandra Stephens

  4. Expedition 54 plaque hanging ceremony

    NASA Image and Video Library

    2018-04-26

    NASA astronauts Joe Acaba and Mark Vande Hei Acaba visited Marshall April 11 for their honorary Expedition 54 plaque hanging ceremony and to provide valuable feedback of their on-orbit science investigations with the Payload Operations and Integration Center team. Astronauts Mark Vande Hei (L) and Astronaut Joe Acaba sign autographs for Lori Meggs.

  5. Expedition 54 plaque hanging ceremony

    NASA Image and Video Library

    2018-04-26

    NASA astronauts Joe Acaba and Mark Vande Hei Acaba visited Marshall April 11 for their honorary Expedition 54 plaque hanging ceremony and to provide valuable feedback of their on-orbit science investigations with the Payload Operations and Integration Center team. Payload Operations Director Phillipia Simmons with Astronauts Joe Acaba (L) and Mark Vande Hei

  6. Expedition 54 plaque hanging ceremony

    NASA Image and Video Library

    2018-04-26

    NASA astronauts Joe Acaba and Mark Vande Hei Acaba visited Marshall April 11 for their honorary Expedition 54 plaque hanging ceremony and to provide valuable feedback of their on-orbit science investigations with the Payload Operations and Integration Center team. Astronauts Mark Vande Hei (L) and Astronaut Joe Acaba sign autographs for Samantha Gurley.

  7. IMPY: an improved thioflavin-T derivative for in vivo labeling of beta-amyloid plaques.

    PubMed

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

    2002-11-29

    Development of small molecular probes for in vivo labeling and detection of beta-amyloid (Abeta) plaques in patients of Alzheimer's disease (AD) is of significant scientific interest, and it may also assist the development of drugs targeting Abeta plaques for treatment of AD. A novel probe, [123I/(125)I]IMPY, 6-iodo-2-(4'-dimethylamino-)phenyl-imidazo[1,2-a]pyridine, was successfully prepared with an iododestannylation reaction catalyzed by hydrogen peroxide. The modified thioflavin-T derivative displayed a good binding affinity for preformed synthetic Abeta40 aggregates in solution (K(i)=15+/-5 nM) and showed selective plaque labeling on postmortem AD brain sections. Biodistribution study in normal mice after an iv injection of [125I]IMPY exhibited excellent brain uptake (2.9% initial dose/brain at 2 min) and fast washout (0.2% initial dose/brain at 60 min). These properties are highly desirable for amyloid plaque imaging agents. In vivo plaque labeling was evaluated in a transgenic mouse model (Tg2576) engineered to produce excess amyloid plaques in the brain. Ex vivo autoradiograms of brain sections of the Tg 2576 mouse obtained at 4 h after an i.v. injection of [125I]IMPY clearly displayed a distinct plaque labeling with a low background activity. When the same brain section was stained with a fluorescent dye, thioflavin-S, the same Abeta plaques showed prominent fluorescent labeling consistent with the results of the autoradiogram. In conclusion, these findings clearly suggest that radioiodinated IMPY demonstrates desirable characteristics for in vivo labeling of Abeta plaques and it may be useful as a molecular imaging agent to study amyloidogenesis in the brain of living AD patients. Copyright 2002 Elsevier Science B.V.

  8. High-speed Intravascular Photoacoustic Imaging of Lipid-laden Atherosclerotic Plaque Enabled by a 2-kHz Barium Nitrite Raman Laser

    PubMed Central

    Wang, Pu; Ma, Teng; Slipchenko, Mikhail N.; Liang, Shanshan; Hui, Jie; Shung, K. Kirk; Roy, Sukesh; Sturek, Michael; Zhou, Qifa; Chen, Zhongping; Cheng, Ji-Xin

    2014-01-01

    Lipid deposition inside the arterial wall is a key indicator of plaque vulnerability. An intravascular photoacoustic (IVPA) catheter is considered a promising device for quantifying the amount of lipid inside the arterial wall. Thus far, IVPA systems suffered from slow imaging speed (~50 s per frame) due to the lack of a suitable laser source for high-speed excitation of molecular overtone vibrations. Here, we report an improvement in IVPA imaging speed by two orders of magnitude, to 1.0 s per frame, enabled by a custom-built, 2-kHz master oscillator power amplifier (MOPA)-pumped, barium nitrite [Ba(NO3)2] Raman laser. This advancement narrows the gap in translating the IVPA technology to the clinical setting. PMID:25366991

  9. Intravascular optical imaging of high-risk plaques in vivo by targeting macrophage mannose receptors

    NASA Astrophysics Data System (ADS)

    Kim, Ji Bak; Park, Kyeongsoon; Ryu, Jiheun; Lee, Jae Joong; Lee, Min Woo; Cho, Han Saem; Nam, Hyeong Soo; Park, Ok Kyu; Song, Joon Woo; Kim, Tae Shik; Oh, Dong Joo; Gweon, Daegab; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

    2016-03-01

    Macrophages mediate atheroma expansion and disruption, and denote high-risk arterial plaques. Therefore, they are substantially gaining importance as a diagnostic imaging target for the detection of rupture-prone plaques. Here, we developed an injectable near-infrared fluorescence (NIRF) probe by chemically conjugating thiolated glycol chitosan with cholesteryl chloroformate, NIRF dye (cyanine 5.5 or 7), and maleimide-polyethylene glycol-mannose as mannose receptor binding ligands to specifically target a subset of macrophages abundant in high-risk plaques. This probe showed high affinity to mannose receptors, low toxicity, and allowed the direct visualization of plaque macrophages in murine carotid atheroma. After the scale-up of the MMR-NIRF probe, the administration of the probe facilitated in vivo intravascular imaging of plaque inflammation in coronary-sized vessels of atheromatous rabbits using a custom-built dual-modal optical coherence tomography (OCT)-NIRF catheter-based imaging system. This novel imaging approach represents a potential imaging strategy enabling the identification of high-risk plaques in vivo and holds promise for future clinical implications.

  10. Intravascular optical imaging of high-risk plaques in vivo by targeting macrophage mannose receptors

    PubMed Central

    Kim, Ji Bak; Park, Kyeongsoon; Ryu, Jiheun; Lee, Jae Joong; Lee, Min Woo; Cho, Han Saem; Nam, Hyeong Soo; Park, Ok Kyu; Song, Joon Woo; Kim, Tae Shik; Oh, Dong Joo; Gweon, DaeGab; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

    2016-01-01

    Macrophages mediate atheroma expansion and disruption, and denote high-risk arterial plaques. Therefore, they are substantially gaining importance as a diagnostic imaging target for the detection of rupture-prone plaques. Here, we developed an injectable near-infrared fluorescence (NIRF) probe by chemically conjugating thiolated glycol chitosan with cholesteryl chloroformate, NIRF dye (cyanine 5.5 or 7), and maleimide-polyethylene glycol-mannose as mannose receptor binding ligands to specifically target a subset of macrophages abundant in high-risk plaques. This probe showed high affinity to mannose receptors, low toxicity, and allowed the direct visualization of plaque macrophages in murine carotid atheroma. After the scale-up of the MMR-NIRF probe, the administration of the probe facilitated in vivo intravascular imaging of plaque inflammation in coronary-sized vessels of atheromatous rabbits using a custom-built dual-modal optical coherence tomography (OCT)-NIRF catheter-based imaging system. This novel imaging approach represents a potential imaging strategy enabling the identification of high-risk plaques in vivo and holds promise for future clinical implications. PMID:26948523

  11. The effect of iron plaque on lead translocation in soil-Carex cinerascens kukenth. system.

    PubMed

    Liu, Chunying; Gong, Xiaofeng; Chen, Chunli; Yang, Juyun; Xu, Sheng

    2016-01-01

    A pot experiment was conducted to investigate the effect of iron plaque on Pb uptake by and translocation in Carex cinerascens Kukenth. grown under open-air conditions. Using Scanning Electron Microscopy and Energy Dispersive X-Ray Spectrometry, iron plaque was present as an amorphous coating on root surfaces with uneven distribution. The amount of iron plaque increased significantly with increasing Fe additions regardless of Pb additions. The presence of iron plaque on the root surface of Carex cinerascens Kukenth. increased the concentrations of Pb adsorbed by iron plaque. The Pb percentage in whole roots increased by 14.52% at 500 mg kg(-1) Fe treatment than at 0 mg kg(-1) Fe, and the distribution coefficient (DC) of Pb and translocation factor (TF) root increased with Fe additions, but translocation factor (TF) shoot decreased with Fe additions. The results suggested that iron plaque could promote the translocation of Pb from soil to roots to some extent, and it played a role to reduce heavy metals pollution of Poyang Lake wetland.

  12. Particulate matter air pollution exposure promotes recruitment of monocytes into atherosclerotic plaques.

    PubMed

    Yatera, Kazuhiro; Hsieh, Joanne; Hogg, James C; Tranfield, Erin; Suzuki, Hisashi; Shih, Chih-Horng; Behzad, Ali R; Vincent, Renaud; van Eeden, Stephan F

    2008-02-01

    Epidemiologic studies have shown an association between exposure to ambient particulate air pollution <10 microm in diameter (PM(10)) and increased cardiovascular morbidity and mortality. We previously showed that PM(10) exposure causes progression of atherosclerosis in coronary arteries. We postulate that the recruitment of monocytes from the circulation into atherosclerotic lesions is a key step in this PM(10)-induced acceleration of atherosclerosis. The study objective was to quantify the recruitment of circulating monocytes into vessel walls and the progression of atherosclerotic plaques induced by exposure to PM(10). Female Watanabe heritable hyperlipidemic rabbits, which naturally develop systemic atherosclerosis, were exposed to PM(10) (EHC-93) or vehicle by intratracheal instillation twice a week for 4 wk. Monocytes, labeled with 5-bromo-2'-deoxyuridine (BrdU) in donors, were transfused to recipient rabbits as whole blood, and the recruitment of BrdU-labeled cells into vessel walls and plaques in recipients was measured by quantitative histological methodology. Exposure to PM(10) caused progression of atherosclerotic lesions in thoracic and abdominal aorta. It also decreased circulating monocyte counts, decreased circulating monocytes expressing high levels of CD31 (platelet endothelial cell adhesion molecule-1) and CD49d (very late antigen-4 alpha-chain), and increased expression of CD54 (ICAM-1) and CD106 (VCAM-1) in plaques. Exposure to PM(10) increased the number of BrdU-labeled monocytes adherent to endothelium over plaques and increased the migration of BrdU-labeled monocytes into plaques and smooth muscle underneath plaques. We conclude that exposure to ambient air pollution particles promotes the recruitment of circulating monocytes into atherosclerotic plaques and speculate that this is a critically important step in the PM(10)-induced progression of atherosclerosis.

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

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

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

  14. Vulnerability survival analysis: a novel approach to vulnerability management

    NASA Astrophysics Data System (ADS)

    Farris, Katheryn A.; Sullivan, John; Cybenko, George

    2017-05-01

    Computer security vulnerabilities span across large, enterprise networks and have to be mitigated by security engineers on a routine basis. Presently, security engineers will assess their "risk posture" through quantifying the number of vulnerabilities with a high Common Vulnerability Severity Score (CVSS). Yet, little to no attention is given to the length of time by which vulnerabilities persist and survive on the network. In this paper, we review a novel approach to quantifying the length of time a vulnerability persists on the network, its time-to-death, and predictors of lower vulnerability survival rates. Our contribution is unique in that we apply the cox proportional hazards regression model to real data from an operational IT environment. This paper provides a mathematical overview of the theory behind survival analysis methods, a description of our vulnerability data, and an interpretation of the results.

  15. 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

  16. Mapping Vulnerability to Disasters in Latin America and the Caribbean, 1900-2007

    USGS Publications Warehouse

    Maynard-Ford, Miriam C.; Phillips, Emily C.; Chirico, Peter G.

    2008-01-01

    The vulnerability of a population and its infrastructure to disastrous events is a factor of both the probability of a hazardous event occurring and the community's ability to cope with the resulting impacts. Therefore, the ability to accurately identify vulnerable populations and places in order to prepare for future hazards is of critical importance for disaster mitigation programs. This project created maps of higher spatial resolution of vulnerability to disaster in Latin America and the Caribbean from 1900 to 2007 by mapping disaster data by first-level administrative boundaries with the objective of identifying geographic trends in regional occurrences of disasters and vulnerable populations. The method of mapping by administrative level is an improvement on displaying and analyzing disasters at the country level and shows the relative intensity of vulnerability within and between countries in the region. Disaster mapping at the country level produces only a basic view of which countries experience various types of natural disasters. Through disaggregation, the data show which geographic areas of these countries, including populated areas, are historically most susceptible to different hazard types.

  17. Modeling of Mechanical Stress Exerted by Cholesterol Crystallization on Atherosclerotic Plaques.

    PubMed

    Luo, Yuemei; Cui, Dongyao; Yu, Xiaojun; Chen, Si; Liu, Xinyu; Tang, Hongying; Wang, Xianghong; Liu, Linbo

    2016-01-01

    Plaque rupture is the critical cause of cardiovascular thrombosis, but the detailed mechanisms are not fully understood. Recent studies have found abundant cholesterol crystals in ruptured plaques, and it has been proposed that the rapid expansion of cholesterol crystals in a limited space during crystallization may contribute to plaque rupture. To evaluate the effect of cholesterol crystal growth on atherosclerotic plaques, we modeled the expansion of cholesterol crystals during the crystallization process in the necrotic core and estimated the stress on the thin cap with different arrangements of cholesterol crystals. We developed a two-dimensional finite element method model of atherosclerotic plaques containing expanding cholesterol crystals and investigated the effect of the magnitude and distribution of crystallization on the peak circumferential stress born by the cap. Using micro-optical coherence tomography (μOCT), we extracted the cross-sectional geometric information of cholesterol crystals in human atherosclerotic aorta tissue ex vivo and applied the information to the model. The results demonstrate that (1) the peak circumference stress is proportionally dependent on the cholesterol crystal growth; (2) cholesterol crystals at the cap shoulder impose the highest peak circumference stress; and (3) spatial distributions of cholesterol crystals have a significant impact on the peak circumference stress: evenly distributed cholesterol crystals exert less peak circumferential stress on the cap than concentrated crystals.

  18. Polarization properties of amyloid-beta plaques in Alzheimer's disease (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Baumann, Bernhard; Wöhrer, Adelheid; Ricken, Gerda; Pircher, Michael; Kovacs, Gabor G.; Hitzenberger, Christoph K.

    2016-03-01

    In histopathological practice, birefringence is used for the identification of amyloidosis in numerous tissues. Amyloid birefringence is caused by the parallel arrangement of fibrous protein aggregates. Since neurodegenerative processes in Alzheimer's disease (AD) are also linked to the formation of amyloid-beta (Aβ) plaques, optical methods sensitive to birefringence may act as non-invasive tools for Aβ identification. At last year's Photonics West, we demonstrated polarization-sensitive optical coherence tomography (PS-OCT) imaging of ex vivo cerebral tissue of advanced stage AD patients. PS-OCT provides volumetric, structural imaging based on both backscatter contrast and tissue polarization properties. In this presentation, we report on polarization-sensitive neuroimaging along with numerical simulations of three-dimensional Aβ plaques. High speed PS-OCT imaging was performed using a spectral domain approach based on polarization maintaining fiber optics. The sample beam was interfaced to a confocal scanning microscope arrangement. Formalin-fixed tissue samples as well as thin histological sections were imaged. For comparison to the PS-OCT results, ray propagation through plaques was modeled using Jones analysis and various illumination geometries and plaque sizes. Characteristic polarization patterns were found. The results of this study may not only help to understand PS-OCT imaging of neuritic Aβ plaques but may also have implications for polarization-sensitive imaging of other fibrillary structures.

  19. Dental plaque bacteria with reduced susceptibility to chlorhexidine are multidrug resistant.

    PubMed

    Saleem, Hafiz Ghulam Murtaza; Seers, Christine Ann; Sabri, Anjum Nasim; Reynolds, Eric Charles

    2016-09-15

    Chlorhexidine (CHX) is used in oral care products to help control dental plaque. In this study dental plaque bacteria were grown on media containing 2 μg/ml chlorhexidine gluconate to screen for bacteria with reduced CHX susceptibility. The isolates were characterized by 16S rRNA gene sequencing and antibiotic resistance profiles were determined using the disc diffusion method. The isolates were variably resistant to multiple drugs including ampicillin, kanamycin, gentamicin and tetracycline. Two species, Chryseobacterium culicis and Chryseobacterium indologenes were able to grow planktonically and form biofilms in the presence of 32 μg/ml CHX. In the CHX and multidrug resistant C. indologenes we demonstrated a 19-fold up-regulation of expression of the HlyD-like periplasmic adaptor protein of a tripartite efflux pump upon exposure to 16 μg/ml CHX suggesting that multidrug resistance may be mediated by this system. Exposure of biofilms of these resistant species to undiluted commercial CHX mouthwash for intervals from 5 to 60 s indicated that the mouthwash was unlikely to eliminate them from dental plaque in vivo. The study highlights the requirement for increased vigilance of the presence of multidrug resistant bacteria in dental plaque and raises a potential risk of long-term use of oral care products containing antimicrobial agents for the control of dental plaque.

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

    PubMed

    Lang, Tomas; Staufer, Sebastian; Jennes, Barbara; Gaengler, Peter

    2014-07-04

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

  1. Calibration of groundwater vulnerability mapping using the generalized reduced gradient method.

    PubMed

    Elçi, Alper

    2017-12-01

    Groundwater vulnerability assessment studies are essential in water resources management. Overlay-and-index methods such as DRASTIC are widely used for mapping of groundwater vulnerability, however, these methods mainly suffer from a subjective selection of model parameters. The objective of this study is to introduce a calibration procedure that results in a more accurate assessment of groundwater vulnerability. The improvement of the assessment is formulated as a parameter optimization problem using an objective function that is based on the correlation between actual groundwater contamination and vulnerability index values. The non-linear optimization problem is solved with the generalized-reduced-gradient (GRG) method, which is numerical algorithm based optimization method. To demonstrate the applicability of the procedure, a vulnerability map for the Tahtali stream basin is calibrated using nitrate concentration data. The calibration procedure is easy to implement and aims the maximization of correlation between observed pollutant concentrations and groundwater vulnerability index values. The influence of each vulnerability parameter in the calculation of the vulnerability index is assessed by performing a single-parameter sensitivity analysis. Results of the sensitivity analysis show that all factors are effective on the final vulnerability index. Calibration of the vulnerability map improves the correlation between index values and measured nitrate concentrations by 19%. The regression coefficient increases from 0.280 to 0.485. It is evident that the spatial distribution and the proportions of vulnerability class areas are significantly altered with the calibration process. Although the applicability of the calibration method is demonstrated on the DRASTIC model, the applicability of the approach is not specific to a certain model and can also be easily applied to other overlay-and-index methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Distinguishing characteristics of idiopathic calcium oxalate kidney stone formers with low amounts of Randall's plaque.

    PubMed

    Wang, Xiangling; Krambeck, Amy E; Williams, James C; Tang, Xiaojing; Rule, Andrew D; Zhao, Fang; Bergstralh, Eric; Haskic, Zejfa; Edeh, Samuel; Holmes, David R; Herrera Hernandez, Loren P; Lieske, John C

    2014-10-07

    Overgrowth of calcium oxalate on Randall's plaque is a mechanism of stone formation among idiopathic calcium oxalate stone-formers (ICSFs). It is less clear how stones form when there is little or no plaque. Participants were a consecutive cohort of ICSFs who underwent percutaneous nephroscopic papillary mapping in the kidney or kidneys containing symptomatic stones and a papillary tip biopsy from a representative calyx during a stone removal procedure between 2009 and 2013. The distribution of Randall's plaque coverage was analyzed and used to divide ICSFs into those with a high (≥5%; mean, 10.5%; n=10) versus low (<5%; mean, 1.5%; n=32) amount of plaque coverage per papilla. Demographic and laboratory features were compared between these two groups. Low-plaque stone formers tended to be obese (50% versus 10%; P=0.03) and have a history of urinary tract infection (34% versus 0%; P=0.04). They were less likely to have multiple prior stone events (22% versus 80%; P=0.002) and had a lower mean 24-hour urine calcium excretion (187±86 mg versus 291±99 mg; P<0.01). Morphologically, stones from patients with low amounts of plaque lacked a calcium phosphate core by microcomputed tomography. Papillary biopsies from low plaque stone-formers revealed less interstitial and basement membrane punctate crystallization. These findings suggest that other pathways independent of Randall's plaque may contribute to stone pathogenesis among a subgroup of ICSFs who harbor low amounts of plaque. Copyright © 2014 by the American Society of Nephrology.

  3. Evaluation of chlorhexidine 0.05% with the adjunct of fluoride 0.05% in the inhibition of plaque formation: a double blind, crossover, plaque regrowth study.

    PubMed

    De Siena, F; Del Fabbro, M; Corbella, S; Taschieri, S; Weinstein, R

    2013-08-01

    The aim of this study was to evaluate the effect of mouthrinses containing 0.05% chlorhexidine + 0.05% fluoride solution on early dental plaque regrowth. Thirty periodontally healthy subjects were included in the study. A crossover 4-day plaque regrowth protocol was adopted. The test product was initially used in 15 patients, while a placebo was administered to the other 15 patients. Then, after a washout period, each patient used the other product. No other oral hygiene manoeuvre was allowed. Full-mouth plaque and bleeding scores (FMPS and FMBS) were evaluated at baseline and after 4 days. All subjects completed the study. The mean age was 27 ± 8.4 years. Five patients were smokers with a mean daily consumption of 1 ± 2.5 cigarettes. FMPS at baseline was 8.0 ± 4.4 for control group and 7.9 ± 3.8 for test group, without significant difference. After the 4-day plaque regrowth the mean FMPS significantly increased to 31.9 ± 16.5 and 36.3 ± 16.1 for control and test group, respectively (no significant difference between the two groups). The test product was safe and well tolerated by subjects. The similar outcomes of the two experimental groups suggest that the two products have an equivalent effect on early dental plaque regrowth. Studies with longer follow-up are needed to clarify whether there is a beneficial long-term effect of daily rinses with the tested solution. © 2012 John Wiley & Sons A/S.

  4. Multidentate (18)F-polypegylated styrylpyridines as imaging agents for Aβ plaques in cerebral amyloid angiopathy (CAA).

    PubMed

    Zha, Zhihao; Choi, Seok Rye; Ploessl, Karl; Lieberman, Brian P; Qu, Wenchao; Hefti, Franz; Mintun, Mark; Skovronsky, Daniel; Kung, Hank F

    2011-12-08

    β-Amyloid plaques (Aβ plaques) in the brain are associated with cerebral amyloid angiopathy (CAA). Imaging agents that could target the Aβ plaques in the living human brain would be potentially valuable as biomarkers in patients with CAA. A new series of (18)F styrylpyridine derivatives with high molecular weights for selectively targeting Aβ plaques in the blood vessels of the brain but excluded from the brain parenchyma is reported. The styrylpyridine derivatives, 8a-c, display high binding affinities and specificity to Aβ plaques (K(i) = 2.87, 3.24, and 7.71 nM, respectively). In vitro autoradiography of [(18)F]8a shows labeling of β-amyloid plaques associated with blood vessel walls in human brain sections of subjects with CAA and also in the tissue of AD brain sections. The results suggest that [(18)F]8a may be a useful PET imaging agent for selectively detecting Aβ plaques associated with cerebral vessels in the living human brain.

  5. HDL-mimetic PLGA nanoparticle to target atherosclerosis plaque macrophages.

    PubMed

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

    2015-03-18

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

  6. HDL-Mimetic PLGA Nanoparticle To Target Atherosclerosis Plaque Macrophages

    PubMed Central

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

    2015-01-01

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

  7. Association of CD147 genetic polymorphisms with carotid atherosclerotic plaques in a Han Chinese population with cerebral infarction.

    PubMed

    Ni, Tongtian; Chen, Min; Yang, Kang; Shao, Jianwei; Fu, Yi; Zhou, Weijun

    2017-08-01

    Given the important role of CD147 in the development of atherosclerosis, we speculated that CD147 genetic polymorphisms might influence the formation of carotid atherosclerotic plaques. The study was to investigate the association between CD147 gene polymorphisms and susceptibility to carotid atherosclerotic plaques in individuals with cerebral infarction (CI). Eight SNPs in the regulatory and coding regions of the CD147 gene were examined using polymerase chain reaction-ligase detection reaction (PCR-LDR) in DNA samples from 732 Chinese patients with CI, divided into a carotid plaque group (n=475) and a non-carotid plaque group (n=257). Significant differences were found in the genotypes and allele frequencies of the rs4919862 SNP between the carotid plaque and non-carotid plaque groups of CI patients (P<0.05), while the frequencies of the C allele and the CC genotype in the non-carotid plaque group were significantly lower than those in the carotid plaque group, and the frequencies of the T allele in the non-carotid plaque group were significantly higher than those in the carotid plaque group (P<0.05). In addition, there was strong linkage disequilibrium among the rs4919862, rs8637 and rs8259 sites. In a haplotype analysis, the occurrence rate of the haplotype GATGCAGC was 2.095 times higher in the carotid plaque group than in the non-carotid plaque group (P<0.05). These results showed that the rs4919862 SNP of CD147 was closely associated with carotid atherosclerotic plaques formation. Thus, polymorphisms of the CD147 gene may be related to the tendency for carotid atherosclerotic plaques. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Effect of fluoride on growth and acid production by Streptococcus mutans in dental plaque.

    PubMed Central

    van der Hoeven, J S; Franken, H C

    1984-01-01

    The aim of this study was to measure the effect of fluoride on the production of organic acids by Streptococcus mutans in dental plaque. The effect was studied in a simplified model of dental plaque with gnotobiotic rats monoinfected with S. mutans Ny341. Adaptation of S. mutans to fluoride was induced by feeding one group of the rats on fluoride-containing diet and drinking water. No difference was found in the accumulation of S. mutans on the teeth between the fluoride-adapted and the control groups. However, there was a significant difference in the amount of lactic acid in metabolically resting plaque between the groups, lactic acid being lower in the fluoride-adapted plaque. At 5 min after a rinse containing 10% sucrose, a high level of lactic acid was found in plaque from animals not exposed to fluoride. Rinses containing 4 or 20 mM fluoride before the sucrose rinse significantly inhibited the lactic acid production in the control group. In the plaque from rats on fluoridated diet and drinking water the sucrose-induced production of lactic acid was not inhibited by a 4 mM fluoride rinse. Moreover, the production of lactic acid in the fluoride-adapted plaque was prolonged. The results indicate that due to fluoride adaptation the inhibition of acid production is unlikely to be important for the caries-preventive action of fluoride. PMID:6746094

  10. Cyber / Physical Security Vulnerability Assessment Integration

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

    MacDonald, Douglas G.; Simpkins, Bret E.

    Abstract Both physical protection and cyber security domains offer solutions for the discovery of vulnerabilities through the use of various assessment processes and software tools. Each vulnerability assessment (VA) methodology provides the ability to identify and categorize vulnerabilities, and quantifies the risks within their own areas of expertise. Neither approach fully represents the true potential security risk to a site and/or a facility, nor comprehensively assesses the overall security posture. The technical approach to solving this problem was to identify methodologies and processes that blend the physical and cyber security assessments, and develop tools to accurately quantify the unaccounted formore » risk. SMEs from both the physical and the cyber security domains developed the blending methodologies, and cross trained each other on the various aspects of the physical and cyber security assessment processes. A local critical infrastructure entity volunteered to host a proof of concept physical/cyber security assessment, and the lessons learned have been leveraged by this effort. The four potential modes of attack an adversary can use in approaching a target are; Physical Only Attack, Cyber Only Attack, Physical Enabled Cyber Attack, and the Cyber Enabled Physical Attack. The Physical Only and the Cyber Only pathway analysis are two of the most widely analyzed attack modes. The pathway from an off-site location to the desired target location is dissected to ensure adversarial activity can be detected and neutralized by the protection strategy, prior to completion of a predefined task. This methodology typically explores a one way attack from the public space (or common area) inward towards the target. The Physical Enabled Cyber Attack and the Cyber Enabled Physical Attack are much more intricate. Both scenarios involve beginning in one domain to affect change in the other, then backing outward to take advantage of the reduced system effectiveness

  11. The role of microglial cells and astrocytes in fibrillar plaque evolution in transgenic APP(SW) mice.

    PubMed

    Wegiel, J; Wang, K C; Imaki, H; Rubenstein, R; Wronska, A; Osuchowski, M; Lipinski, W J; Walker, L C; LeVine, H

    2001-01-01

    Ultrastructural reconstruction of 27 fibrillar plaques in different stages of formation and maturation was undertaken to characterize the development of fibrillar plaques in the brains of human APP(SW) transgenic mice (Tg2576). The study suggests that microglial cells are not engaged in Abeta removal and plaque degradation, but in contrast, are a driving force in plaque formation and development. Fibrillar Abeta deposition at the amyloid pole of microglial cells appears to initiate three types of neuropil response: degeneration of neurons, protective activation of astrocytes, and attraction and activation of microglial cells sustaining plaque growth. Enlargement of neuronal processes and synapses with accumulation of degenerated mitochondria, dense bodies, and Hirano-type bodies is the marker of toxic injury of neurons by fibrillar Abeta. Separation of amyloid cores from neurons and degradation of amyloid cores by cytoplasmic processes of hypertrophic astrocytes suggest the protective and defensive character of astrocytic response to fibrillar Abeta. The growth of cored plaque from a small plaque with one microglial cell with an amyloid star and a few dystrophic neurites to a large plaque formed by several dozen microglial cells seen in old mice is the effect of attraction and activation of microglial cells residing outside of the plaque perimeter. This mechanism of growth of plaques appears to be characteristic of cored plaques in transgenic mice. Other features in mouse microglial cells that are absent in human brain are clusters of vacuoles, probably of lysosomal origin. They evolve into circular cisternae and finally into large vacuoles filled with osmiophilic, amorphous material and bundles of fibrils that are poorly labeled with antibody to Abeta. Microglial cells appear to release large amounts of fibrillar Abeta and accumulate traces of fibrillar Abeta in a lysosomal pathway.

  12. Predicting carotid artery disease and plaque instability from cell-derived microparticles.

    PubMed

    Wekesa, A L; Cross, K S; O'Donovan, O; Dowdall, J F; O'Brien, O; Doyle, M; Byrne, L; Phelan, J P; Ross, M D; Landers, R; Harrison, M

    2014-11-01

    Cell-derived microparticles (MPs) are small plasma membrane-derived vesicles shed from circulating blood cells and may act as novel biomarkers of vascular disease. We investigated the potential of circulating MPs to predict (a) carotid plaque instability and (b) the presence of advanced carotid disease. This pilot study recruited carotid disease patients (aged 69.3 ± 1.2 years [mean ± SD], 69% male, 90% symptomatic) undergoing endarterectomy (n = 42) and age- and sex-matched controls (n = 73). Plaques were classified as stable (n = 25) or unstable (n = 16) post surgery using immunohistochemistry. Blood samples were analysed for MP subsets and molecular biomarkers. Odds ratios (OR) are expressed per standard deviation biomarker increase. Endothelial MP (EMP) subsets, but not any vascular, inflammatory, or proteolytic molecular biomarker, were higher (p < .05) in the unstable than the stable plaque patients. The area under the receiver operator characteristic curve for CD31(+)41(-) EMP in discriminating an unstable plaque was 0.73 (0.56-0.90, p < .05). CD31(+)41(-) EMP predicted plaque instability (OR = 2.19, 1.08-4.46, p < .05) and remained significant in a multivariable model that included transient ischaemic attack symptom status. Annexin V(+) MP, platelet MP (PMP) subsets, and C-reactive protein were higher (p < .05) in cases than controls. Annexin V(+) MP (OR = 3.15, 1.49-6.68), soluble vascular cell adhesion molecule-1 (OR = 1.64, 1.03-2.59), and previous smoking history (OR = 3.82, 1.38-10.60) independently (p < .05) predicted the presence of carotid disease in a multivariable model. EMP may have utility in predicting plaque instability in carotid patients and annexin V(+) MPs may predict the presence of advanced carotid disease in aging populations, independent of established biomarkers. Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  13. 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

  14. I-125 ROPES eye plaque dosimetry: Validation of a commercial 3D ophthalmic brachytherapy treatment planning system and independent dose calculation software with GafChromic{sup ®} EBT3 films

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

    Poder, Joel; Corde, Stéphanie

    accurately modeled in the planning system. Off-axis profiles were also modeled in PS by taking into account the three-dimensional model of the plaque backing.Conclusions: The doses calculated by PS and RADCALC{sup ®} for uniformly loaded ROPES plaques in full and uniform scattering conditions were validated by the EBT3 film measurements. The stainless steel plaque backing was observed to decrease the measured dose by 4%. Through the introduction of a scalar correction factor (0.96) in PS, the dose homogeneity effect of the stainless steel plaque backing was found to agree with the measured EBT3 film measurements.« less

  15. Dental caries and microbiota in children with black stain and non-discoloured dental plaque.

    PubMed

    Heinrich-Weltzien, R; Bartsch, B; Eick, S

    2014-01-01

    We aimed to assess caries experience and microbiota in systemically healthy children with black stain (BS) and non-discoloured plaque. Forty-six children with BS and 47 counterparts with non-discoloured plaque aged 7.9 ± 1.3 years were clinically examined. Dental caries was scored using WHO criteria. Samples of BS and non-discoloured dental plaque were collected from tooth surfaces. The DNA of the samples was extracted and real-time PCR was performed to determine the total number of bacteria and the species Streptococcus mutans, S. sobrinus, Lactobacillus sp., Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum. Children with BS had lower DMFT (p = 0.013), lower DT values (p = 0.005) and a tendency to lower caries prevalence (p = 0.061) than children with non-discoloured plaque. Plaque samples of the BS group contained higher numbers of A. naeslundii (p = 0.005) and lower numbers of F. nucleatum (p = 0.001) and Lactobacillus sp. (p = 0.001) compared to the non-discoloured plaque samples of the control group. Comparing the children with BS and non-discoloured plaque, higher counts for A. naeslundii (p = 0.013) were observed in caries-free children with BS while in caries-affected children with BS, lower counts of F. nucleatum (p = 0.007) were found. Counts of Lactobacillus sp. were higher in non-discoloured plaque samples than in BS of caries-free and caries-affected children. Results suggest that the different microbial composition of BS might be associated with the lower caries experience in affected subjects. The role of black-pigmented bacteria associated with periodontitis needs further studies.

  16. Stepping inside the niche: microclimate data are critical for accurate assessment of species' vulnerability to climate change.

    PubMed

    Storlie, Collin; Merino-Viteri, Andres; Phillips, Ben; VanDerWal, Jeremy; Welbergen, Justin; Williams, Stephen

    2014-09-01

    To assess a species' vulnerability to climate change, we commonly use mapped environmental data that are coarsely resolved in time and space. Coarsely resolved temperature data are typically inaccurate at predicting temperatures in microhabitats used by an organism and may also exhibit spatial bias in topographically complex areas. One consequence of these inaccuracies is that coarsely resolved layers may predict thermal regimes at a site that exceed species' known thermal limits. In this study, we use statistical downscaling to account for environmental factors and develop high-resolution estimates of daily maximum temperatures for a 36 000 km(2) study area over a 38-year period. We then demonstrate that this statistical downscaling provides temperature estimates that consistently place focal species within their fundamental thermal niche, whereas coarsely resolved layers do not. Our results highlight the need for incorporation of fine-scale weather data into species' vulnerability analyses and demonstrate that a statistical downscaling approach can yield biologically relevant estimates of thermal regimes. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

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

    PubMed Central

    Chaichana, Thanapong; Sun, Zhonghua; Jewkes, James

    2012-01-01

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

  18. 125I eye plaque dose distribution including penumbra characteristics.

    PubMed

    de la Zerda, A; Chiu-Tsao, S T; Lin, J; Boulay, L L; Kanna, I; Kim, J H; Tsao, H S

    1996-03-01

    The two main purposes of this work are (1) to determine the penumbra characteristics for 125I eye plaque and the relative influence of the plaque and eye-air interface on the dose distribution, and (2) to initiate development of a treatment planning algorithm for clinical dose calculations. Dose was measured in a newly designed solid water eye phantom for an 125I (6711) seed at the center of a 20 mm COMS eye plaque using thermoluminescent dosimeter (TLD) "cubes" and "minichips" inside and outside the eye, in the longitudinal and transverse central planes. TLD cubes were used in most locations, except for short distances from the seed and in the penumbra region. In the presence of both the plaque and the eye-air interface, the dose along the central axis was found to be reduced by 10% at 1 cm and up to 20% at 2.5 cm, relative to the bulk homogeneous phantom case. In addition, the overall dose reduction was greater for larger off-axis coordinates at a given depth. The penumbra characteristics due to the lip collimation were quantified, particularly the dependence of penumbra center and width on depth. Only small differences were observed between the profiles in the transverse and longitudinal planes. In the bulk geometry (without the eye-air interface), the dose reduction due to the presence of the plaque alone was found to be 7% at a depth of 2.5 cm. The additional reduction of 13% observed, with the presence of eye-air interface (20% combined), can be attributed to the lack of backscattering from the air in front of the eye. The dose-reduction effect due to the anterior air interface alone became unnoticeable at a depth of 1.1 cm (1.5 cm from the eye-air interface). An analytic fit to measured data was developed for clinical dose calculations for a centrally loaded seed. The central axis values of the dose rates multiplied by distance squared, Dr2, were fitted with a double exponential function of depth. The off-axis profile of Dr2, at a given depth, was

  19. Comparative efficacy of two battery-powered toothbrushes on dental plaque removal.

    PubMed

    Ruhlman, C Douglas; Bartizek, Robert D; Biesbrock, Aaron R

    2002-01-01

    A number of clinical studies have consistently demonstrated that power toothbrushes deliver superior plaque removal compared to manual toothbrushes. Recently, a new power toothbrush (Crest SpinBrush) has been marketed with a design that fundamentally differs from other marketed power toothbrushes. Other power toothbrushes feature a small, round head designed to oscillate for enhanced cleaning between the teeth and below the gumline. The new power toothbrush incorporates a similar round oscillating head in conjunction with fixed bristles, which allows the user to brush with optimal manual brushing technique. The objective of this randomized, examiner-blind, parallel design study was to compare the plaque removal efficacy of a positive control power toothbrush (Colgate Actibrush) to an experimental toothbrush (Crest SpinBrush) following a single use among 59 subjects. Baseline plaque scores were 1.64 and 1.40 for the experimental toothbrush and control toothbrush treatment groups, respectively. With regard to all surfaces examined, the experimental toothbrush delivered an adjusted (via analysis of covariance) mean difference between baseline and post-brushing plaque scores of 0.47, while the control toothbrush delivered an adjusted mean difference of 0.33. On average, the difference between toothbrushes was statistically significant (p = 0.013). Because the covariate slope for the experimental group was statistically significantly greater (p = 0.001) than the slope for the control group, a separate slope model was used. Further analysis demonstrated that the experimental group had statistically significantly greater plaque removal than the control group for baseline plaque scores above 1.43. With respect to buccal surfaces, using a separate slope analysis of covariance, the experimental toothbrush delivered an adjusted mean difference between baseline and post-brushing plaque scores of 0.61, while the control toothbrush delivered an adjusted mean difference of 0

  20. Expedition 54 plaque hanging ceremony

    NASA Image and Video Library

    2018-04-26

    NASA astronauts Joe Acaba and Mark Vande Hei Acaba visited Marshall April 11 for their honorary Expedition 54 plaque hanging ceremony and to provide valuable feedback of their on-orbit science investigations with the Payload Operations and Integration Center team. Chris Buckley is awarded privilege of hanging Mission 54 placque, shown here with Astronaut Mark Vande Hei (L) and Astronaut Joe Acaba

  1. Smooth muscle cells healing atherosclerotic plaque disruptions are of local, not blood, origin in apolipoprotein E knockout mice.

    PubMed

    Bentzon, Jacob F; Sondergaard, Claus S; Kassem, Moustapha; Falk, Erling

    2007-10-30

    Signs of preceding episodes of plaque rupture and smooth muscle cell (SMC)-mediated healing are common in atherosclerotic plaques, but the source of the healing SMCs is unknown. Recent studies suggest that activated platelets adhering to sites of injury recruit neointimal SMCs from circulating bone marrow-derived progenitor cells. Here, we analyzed the contribution of this mechanism to plaque healing after spontaneous and mechanical plaque disruption in apolipoprotein E knockout (apoE-/-) mice. To determine the origin of SMCs after spontaneous plaque disruption, irradiated 18-month-old apoE-/- mice were reconstituted with bone marrow cells from enhanced green fluorescent protein (eGFP) transgenic apoE-/- mice and examined when they died up to 9 months later. Plaque hemorrhage, indicating previous plaque disruption, was widely present, but no bone marrow-derived eGFP+ SMCs were detected. To examine the origin of healing SMCs in a model that recapitulates more features of human plaque rupture and healing, we developed a mechanical technique that produced consistent plaque disruption, superimposed thrombosis, and SMC-mediated plaque healing in apoE-/- mice. Mechanical plaque disruption was produced in irradiated apoE-/- mice reconstituted with eGFP+ apoE-/- bone marrow cells and in carotid bifurcations cross-grafted between apoE-/- and eGFP+ apoE-/- mice. Apart from few non-graft-derived SMCs near the anastomosis site in 1 transplanted carotid bifurcation, no SMCs originating from outside the local arterial segment were detected in healed plaques. Healing SMCs after atherosclerotic plaque disruption are derived entirely from the local arterial wall and not circulating progenitor cells in apoE-/- mice.

  2. Isolation of low-molecular-weight proteins from amyloid plaque fibers in Alzheimer's disease.

    PubMed

    Selkoe, D J; Abraham, C R; Podlisny, M B; Duffy, L K

    1986-06-01

    During aging of the human brain, and particularly in Alzheimer's disease, progressive neuronal loss is accompanied by the formation of highly stable intra- and extraneuronal protein fibers. Using fluorescence-activated particle sorting, a method has been developed for purifying essentially to homogeneity the extracellular amyloid fibers that form the cores of senile plaques. The purified plaque cores each contain 60-130 pg of protein. Their amino acid composition shows abundant glycine, trace proline, and approximately 50% hydrophobic residues; it resembles that of enriched fractions of the paired helical filaments (PHF) that accumulate intraneuronally in Alzheimer's disease. Senile plaque amyloid fibers share with PHF insolubility in numerous protein denaturants and resistance to proteinases. However, treatment of either fiber preparation with concentrated (88%) formic acid or saturated (6.8 M) guanidine thiocyanate followed by sodium dodecyl sulfate causes disappearance of the fibers and releases proteins migrating at 5-7,000 and 11-15,000 Mr which appear to be dimerically related. Following their separation by size-exclusion HPLC, the proteins solubilized from plaque amyloid and PHF-enriched fractions have highly similar compositions and, on dialysis, readily aggregate into higher Mr polymers. Antibodies raised to the major low-Mr protein selectively label both plaque cores and vascular amyloid deposits in Alzheimer brain but do not stain neurofibrillary tangles, senile plaque neurites, or any other neuronal structure. Thus, extraneuronal amyloid plaque filaments in Alzheimer's disease are composed of hydrophobic low-Mr protein(s) which are also present in vascular amyloid deposits. Current evidence suggests that such protein(s) found in PHF-enriched fractions may derive from copurifying amyloid filaments rather than from PHF.

  3. Limitations of a hemolytic plaque assay for IgG-anti-IgG rheumatoid factor-producing cells.

    PubMed

    Venn, A J; Dresser, D W

    1987-09-24

    An attempt has been made to develop a hemolytic plaque assay capable of detecting homophile IgG rheumatoid factor (RF)-producing cells. Anti-immunoglobulin allotype-developing reagents were used to distinguish between target and effector IgG. The hemolytic assay has been used to demonstrate an apparently high level of homophile IgM and IgG RF-producing cells in the spleens and lymph nodes of mice stimulated by LPS. However, it appears that a large proportion of the plaques obtained in these assays are due to an artefact resulting from cross-linking of target and effector molecules by the developing reagents. In the case of IgM RF the artefact depends on the presence of a small contamination of the target IgG by IgM, allowing cross-linking of target and effector IgM by the anti-mu-specific developing reagent. With the IgG RF, cross-reactivity of the rabbit anti-Ighb allotype-developing serum for the 'wrong' (Igha) allotype, normally undetectable, becomes sufficient to be biologically relevant when the developing antibody is complexed by being bound to its target (Ighb) allotype. Nevertheless anti-allotype reagents may afford an accurate means of detecting homophile IgG RF producing cells using other assay systems.

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

    PubMed Central

    2014-01-01

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

  5. Aspartame Intake Relates to Coronary Plaque Burden and Inflammatory Indices in Human Immunodeficiency Virus

    PubMed Central

    Hall, Leangelo N.; Sanchez, Laura R.; Hubbard, Jane; Lee, Hang; Looby, Sara E.; Srinivasa, Suman; Zanni, Markella V.; Stanley, Takara L.; Lo, Janet; Grinspoon, Steven K.

    2017-01-01

    Abstract Background. Dietary sweeteners may contribute to metabolic dysregulation and cardiovascular disease (CVD), but this has not been assessed in human immunodeficiency virus (HIV). Methods. One hundred twenty-four HIV-infected and 56 non-HIV-infected participants, without history of known coronary artery disease were included. Dietary intake was assessed using a 4-day food record. Coronary plaque was determined using cardiac computed tomography angiography. Results. Human immunodeficiency virus-infected participants had significantly greater intake of dietary sweeteners, including total sugar (P = .03) and added sugar (P = .009); intake of aspartame (artificial sweetener) was greater among aspartame consumers with HIV versus non-HIV consumers (P = .03). Among HIV-infected participants, aspartame intake was significantly associated with coronary plaque (P = .002) and noncalcified plaque (P = .007) segments, as well as markers of inflammation/immune activation (monocyte chemoattractant protein 1 and lipoprotein-associated phospholipase A2), which may contribute to increased atherogenesis. In multivariable regression modeling, aspartame remained an independent predictor of plaque in HIV. In contrast, among non-HIV-infected participants, no sweetener type was shown to relate to plaque characteristics. Conclusions. We demonstrate increased intake of dietary sweeteners and a potential novel association between aspartame intake, plaque burden, and inflammation in HIV. Our data suggest that aspartame may contribute to CVD risk in HIV. Further studies should address potential mechanisms by which aspartame may contribute to increased plaque burden and cardiovascular benefits of dietary strategies targeting aspartame intake in HIV. PMID:28695142

  6. [Observation of genetic diversity in dental plaque of elder people with root caries].

    PubMed

    Ma, Shan-fen; Liang, Jing-ping; Jiang, Yun-tao; Zhu, Cai-lian

    2011-08-01

    Bacterial community in dental plaque of elder people was analyzed to learn about the microhabitat composition and diversity. Dental plaque samples were collected from 25 elders. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE) was used to evaluate the microbial diversity by displaying PCR-generated 16SrDNA fragments that migrate at different distances, reflecting the different sequence of fragment. SPSS12.0 software was used to analyze the variance of genotypes between different groups of bacteria. Genotypes of bacteria in dental plaques in the root caries group was significantly more than the other two groups. Crown caries group and caries-free group had no significant difference. The genetic diversity of the dental plaque microflora in the root caries group is significantly higher than coronal caries group and caries-free group.

  7. The influence of salivary variables on fluoride retention in dental plaque exposed to a mineral-enriching solution.

    PubMed

    Kato, K; Nakagaki, H; Arai, K; Pearce, E I F

    2002-01-01

    This study was carried out to examine interindividual differences in salivary variables related to plaque accumulation and to estimate their influence on the fluoride retention in plaque in vivo by a mineral-enriching solution. Two saliva samples were taken from 10 subjects, once after brushing and once after 24 h without brushing. Calcium, phosphate and monofluorophosphatase (MFPase) activity in the saliva samples were determined. The salivary flow rate and the debris index were also recorded. After plaque had formed over 3 days within in situ plaque-generating devices, subjects were instructed to rinse with a mineral-enriching mouthrinse three times a day on 4 consecutive days. Plaque exposed to distilled water plus flavoring agents served as a control. Fluoride-free dentifrice was used during the experimental period. Twenty-four hours after the last rinsing, the samples were removed from the mouth, and fluoride and mineral distributions in plaque analyzed using a method previously reported by the authors. Salivary flow, MFPase activity and calcium concentration in saliva were significantly higher after 24 h of plaque accumulation. Rinsing with the mineral-enriching solution produced retention of fluoride and phosphate in the outer and middle layers of plaque. Salivary calcium concentration had a direct effect on fluoride uptake in plaque, but no obvious relationship was found between other salivary variables and the plaque fluoride retention. The salivary calcium effect may be due to enhanced bacterial cell wall binding of fluoride via calcium bridging. Copyright 2002 S. Karger AG, Basel

  8. Stroke echoscan protocol: a fast and accurate pathway to diagnose embolic strokes.

    PubMed

    Pagola, Jorge; González-Alujas, Teresa; Muchada, Marian; Teixidó, Gisela; Flores, Alan; De Blauwe, Sophie; Seró, Laia; Luna, David Rodríguez; Rubiera, Marta; Ribó, Marc; Boned, Sandra; Álvarez-Sabin, José; Evangelista, Arturo; Molina, Carlos A

    2015-01-01

    Cardiac Echoscan is the simplified transthoracic echocardiogram focused on the main source of emboli detection in the acute stroke diagnosis (Stroke Echoscan). We describe the clinical impact related to the Stroke Echoscan protocol in our Center. Acute stroke patients who underwent the Stroke Echoscan by a trained stroke neurologist were included (Echoscan group). All examinations were reviewed by cardiologists. The main embolic stroke etiologies were: ventricular akinesia (VA), severe aortic atheroma (AA) plaque and cardiac shunt (SHUNT). The rate of the embolic stroke etiologies and the median length of stay (LOS) were compared with a cohort of patients studied by cardiologist (Echo group). Eighty acute stroke patients were included. The sensitivity (S) and specificity (E) were: VA (S 98.6%, E 66.7%, k = .7), AA (S 93.3%, E 96.9%, k = .88) and SHUNT (S 100%, E 100%, k = 1), respectively. The rate of AA diagnosis was significantly higher in Echoscan group (18.8% vs. 8.9%; P = .05). Echoscan protocol significantly reduced the LOS: 6 days (IQR 3-10) versus Echo group 9 days (IQR 6-13; P < .001). The Echoscan protocol was an accurate quick test, which reduced the length of stay and increased the percentage of severe AA plaque diagnosis. Copyright © 2014 by the American Society of Neuroimaging.

  9. Dietary supplementation with resveratrol reduces plaque pathology in a transgenic model of Alzheimer's disease.

    PubMed

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

    2009-02-01

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

  10. Plaque imaging with CT—a comprehensive review on coronary CT angiography based risk assessment

    PubMed Central

    Kolossváry, Márton; Szilveszter, Bálint; Merkely, Béla

    2017-01-01

    CT based technologies have evolved considerably in recent years. Coronary CT angiography (CTA) provides robust assessment of coronary artery disease (CAD). Early coronary CTA imaging—as a gate-keeper of invasive angiography—has focused on the presence of obstructive stenosis. Coronary CTA is currently the only non-invasive imaging modality for the evaluation of non-obstructive CAD, which has been shown to contribute to adverse cardiac events. Importantly, improved spatial resolution of CT scanners and novel image reconstruction algorithms enable the quantification and characterization of atherosclerotic plaques. State-of-the-art CT imaging can therefore reliably assess the extent of CAD and differentiate between various plaque features. Recent studies have demonstrated the incremental prognostic value of adverse plaque features over luminal stenosis. Comprehensive coronary plaque assessment holds potential to significantly improve individual risk assessment incorporating adverse plaque characteristics, the extent and severity of atherosclerotic plaque burden. As a result, several coronary CTA based composite risk scores have been proposed recently to determine patients at high risk for adverse events. Coronary CTA became a promising modality for the evaluation of functional significance of coronary lesions using CT derived fractional flow reserve (FFR-CT) and/or rest/dynamic myocardial CT perfusion. This could lead to substantial reduction in unnecessary invasive catheterization procedures and provide information on ischemic burden of CAD. Discordance between the degree of stenosis and ischemia has been recognized in clinical landmark trials using invasive FFR. Both lesion stenosis and composition are possibly related to myocardial ischemia. The evaluation of lesion-specific ischemia using combined functional and morphological plaque information could ultimately improve the diagnostic performance of CTA and thus patient care. In this review we aimed to

  11. Role of plaque in the clearance of salivary sucrose and its influence on salivary ph.

    PubMed

    Kumar, A; Hedge, R; Dixit, U

    2011-01-01

    The prevalence of dental caries in children, in India, is higher than many of the industrialized countries. The sugar most commonly associated with dental caries is sucrose, as the microorganisms in the dental plaque have the ability to convert this dietary constituent into various organic acids. This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and to study the effect of the presence of plaque on salivary pH, following sucrose clearance. Salivary sucrose determination was done by using the anthrone technique. A Digital MHOS pH meter estimated the salivary pH. Presence of plaque increased the salivary sucrose clearance time and decreased the salivary pH at various time intervals. The microbial etiology of dental caries is the dynamic relationship among the dental plaque microbiota, dietary carbohydrates, saliva and pH lowering, and the cariogenic potential of the dental plaque. Caries occur preferentially in the dentition sites characterized by high exposure to carbohydrate and diminished salivary effect.

  12. Keeping an eye on the ring: COMS plaque loading optimization for improved dose conformity and homogeneity.

    PubMed

    Gagne, Nolan L; Cutright, Daniel R; Rivard, Mark J

    2012-09-01

    To improve tumor dose conformity and homogeneity for COMS plaque brachytherapy by investigating the dosimetric effects of varying component source ring radionuclides and source strengths. The MCNP5 Monte Carlo (MC) radiation transport code was used to simulate plaque heterogeneity-corrected dose distributions for individually-activated source rings of 14, 16 and 18 mm diameter COMS plaques, populated with (103)Pd, (125)I and (131)Cs sources. Ellipsoidal tumors were contoured for each plaque size and MATLAB programming was developed to generate tumor dose distributions for all possible ring weighting and radionuclide permutations for a given plaque size and source strength resolution, assuming a 75 Gy apical prescription dose. These dose distributions were analyzed for conformity and homogeneity and compared to reference dose distributions from uniformly-loaded (125)I plaques. The most conformal and homogeneous dose distributions were reproduced within a reference eye environment to assess organ-at-risk (OAR) doses in the Pinnacle(3) treatment planning system (TPS). The gamma-index analysis method was used to quantitatively compare MC and TPS-generated dose distributions. Concentrating > 97% of the total source strength in a single or pair of central (103)Pd seeds produced the most conformal dose distributions, with tumor basal doses a factor of 2-3 higher and OAR doses a factor of 2-3 lower than those of corresponding uniformly-loaded (125)I plaques. Concentrating 82-86% of the total source strength in peripherally-loaded (131)Cs seeds produced the most homogeneous dose distributions, with tumor basal doses 17-25% lower and OAR doses typically 20% higher than those of corresponding uniformly-loaded (125)I plaques. Gamma-index analysis found > 99% agreement between MC and TPS dose distributions. A method was developed to select intra-plaque ring radionuclide compositions and source strengths to deliver more conformal and homogeneous tumor dose distributions than

  13. 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.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  16. Iron plaque decreases cadmium accumulation in Oryza sativa L. and serves as a source of iron.

    PubMed

    Sebastian, A; Prasad, M N V

    2016-11-01

    Cadmium (Cd) contamination occurs in paddy soils; hence it is necessary to reduce Cd content of rice. Application and mode of action of ferrous sulphate in minimizing Cd in rice was monitored in the present study. Pot culture with Indian rice variety Swarna (MTU 7029) was maintained in Cd-spiked soil containing ferrous sulphates, which is expected to reduce Cd accumulation in rice. Responses in rhizosphere pH, root surface, metal accumulation in plant and molecular physiological processes were monitored. Iron plaque was induced on root surfaces after FeSO4 application and the amount of Fe in plaque reduced with increases in Cd in the soil. Rhizosphere pH decreased during plaque formation and became more acidic due to secretion of organic acids from the roots under Cd treatment. Moreover, iron chelate reductase activity increased with Cd treatment, but in the absence of Cd, activity of this enzyme increased in plaque-induced plants. Cd treatment caused expression of OsYSL18, whereas OsYSL15 was expressed only in roots without iron plaque. Fe content of plants increased during plaque formation, which protected plants from Cd-induced Fe deficiency and metal toxicity. This was corroborated with increased biomass, chlorophyll content and quantum efficiency of photo-synthesis among plaque-induced plants. We conclude that ferrous sulphate-induced iron plaque prevents Cd accumulation and Fe deficiency in rice. Iron released from plaque via organic acid mediated dissolution during Cd stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. Quantification of carotid atherosclerotic plaque components using feature space analysis and magnetic resonance imaging.

    PubMed

    Karmonik, Christof; Basto, Pamela; Morrisett, Joel D

    2006-01-01

    Atherosclerosis is one of the main causes of cardiovascular disease, accounting for more than one third of all deaths in the United States, there is a growing need to develop non-invasive techniques to assess the severity of atherosclerotic plaque burden. Recent research has suggested that not the size of the atherosclerotic plaque but rather its composition is indicative for plaque rupture as the underlying event of stroke and acute coronary syndrome. With its excellent soft-tissue contrast, magnetic resonance imaging (MRI) is a favored modality for examining plaque composition. In an ex-vivo study, aimed to show the feasibility of quantifying the components of carotid atherosclerotic plaques in-vivo, we acquired multi-contrast MRI images of 13 freshly excised endarterectomy tissues with commercially available MRI sequences and a human surface coil. Feature space analysis (FSA) was utilized in four representative tissues to determine the total relative abundance of calcific, lipidic, fibrotic, thrombotic and normal components as well as in consecutive 2 mm sections across the carotid bifurcation in each tissue. Excellent qualitative agreement between the FSA results and the results obtained from histological methods was observed. This study demonstrates the feasibility of combining MRI with FSA to quantify carotid atherosclerotic plaques in-vivo.

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

    PubMed Central

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

    2003-01-01

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

  19. Effect of the presence of dental plaque on oral sugar clearance and salivary pH: an in vivo study.

    PubMed

    Pradhan, Debapriya; Jain, Deepak; Gulati, Amit; Kolhe, Swapnil J; Baad, Rajendra; Rao, B Sunil

    2012-11-01

    Fermentable carbohydrates and microorganisms in the plaque play a significant role in the pathogenesis of dental caries. Oral clearance of sugars and salivary pH is affected by the presence of plaque. This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and on salivary pH. The study design was of a randomized controlled parallel group clinical trial and included two groups: The control group and plaque group, as follows: Control group--subjects without plaque and plaque group--subjects with plaque. Salivary sucrose determination was done by using the anthrone technique. A digital pH meter estimated the salivary pH. The Student's t test and Mann-Whitney test was employed to compare the intergroup differences. Pearson's correlation coefficient was used for analysis. The salivary sucrose clearance time was increased by presence of plaque. The presence of plaque led to increased salivary sucrose concentrations and increased the salivary sucrose clearance time. The dental caries is the dynamic relationship among the dental plaque microbiota, dietary carbohydrates, saliva and cariogenic potential of the dental plaque. Caries occur preferentially in the dentition sites characterized by high exposure to carbohydrate and diminished salivary effect.

  20. Short-term effects of povidone iodine and sodium fluoride therapy on plaque levels and microbiome diversity.

    PubMed

    Reilly, C; Goettl, M; Steinmetz, M; Nikrad, J; Jones, R S

    2016-03-01

    The objective of this study is to evaluate the effect of short-term changes in the oral microbial ecology of dental plaque and plaque levels after topical treatment of a combination of 10% povidone iodine (PI) and 5% sodium fluoride varnish (FV). A single group design intervention study on 12 pediatric patients, who underwent two baseline plaques samplings before the intervention, were enrolled in the study. A modified mixed dentition Silness-Löe plaque index score was used to assess plaque accumulation and microbial composition was assessed by amplicon sequencing analysis of the 16S rRNA V4 region. Dental plaque accumulation (P = 0.0424) was reduced after 1 week using PI/FV application. This reduction was not observed between the two double-baseline visits. 16S rRNA analysis showed that the single PI/FV therapy did not have dramatic shifts in the plaque microbiome community depicted by hierarchical cluster and principle component analysis. More subtle changes were found when analyzing the Shannon diversity index after the application of PI/FV vs two baselines prior to combination therapy. The bacteria within the dental biofilms showed resilience in maintaining the overall community diversity but reduced biofilm accumulation following PI/FV therapy. Repeated uses of PI/FV may augment plaque control during dental rehabilitation in children. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.