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The objective quantitative evaluation of the extent of plaques is necessary for epidemiologic studies and for the estimation of the effects of various cleaning methods and agents. Numerous indices have been elaborated for this purpose. Relation planimetry is used for the detection and exact evaluation of small differences. The surfaces are measured with a compensating planimeter, the slides to be evaluated being projected on a white sheet by means of a microfilm reader. In this way, the plaque covered surfaces are determined as percentages of the total surfaces. PMID:283608
Kötzschke, R
Plaque Inhibiting Oligosaccharide.
National Technical Information Service (NTIS)
The present invention relates to a purified oligosaccharide which can be isolated from a natural source, e.g. from the cell wall polysaccharide of Streptococcus sanguis. S. sanguis is found in significant numbers in human dental plaque. This oligosacchari...
F. J. Cassels J. London
Sintered plaque characteristics
NASA Technical Reports Server (NTRS)
The structural transformations occurring during sintering, the fabrication of a slurry produced sintered plaque, are detailed. Degradation of the positive electrode in performance in cycling in a nickel hydrogen battery were traced to the quality of the sintered plaque. Electrode degradation was found to be a limiting factor in the battery cycle life. Details of microstructural characterization and distribution of pores, examination of plastic flow during shrinkage, and observations of the rounding of nickel powder particles during the slurry process are presented.
Vaidyanathan, H.
Plaque assay for murine norovirus.
Murine norovirus (MNV) is the only member of the Norovirus genus that efficiently grows in tissue culture. Cell lysis and cytopathic effect (CPE) are observed during MNV-1 infection of murine dendritic cells or macrophages. This property of MNV-1 can be used to quantify the number of infectious particles in a given sample by performing a plaque assay. The plaque assay relies on the ability of MNV-1 to lyse cells and to form holes in a confluent cell monolayer, which are called plaques. Multiple techniques can be used to detect viral infections in tissue culture, harvested tissue, clinical, and environmental samples, but not all measure the number of infectious particles (e.g. qRT-PCR). One way to quantify infectious viral particles is to perform a plaque assay, which will be described in detail below. A variation on the MNV plaque assay is the fluorescent focus assay, where MNV antigen is immunostained in cell monolayers. This assay can be faster, since viral antigen expression precedes plaque formation. It is also useful for titrating viruses unable to form plaques. However, the fluorescent focus assay requires additional resources beyond those of the plaque assay, such as antibodies and a microscope to count focus-forming units. Infectious MNV can also be quantified by determining the 50% Tissue Culture Infective Dose (TCID50). This assay measures the amount of virus required to produce CPE in 50% of inoculated tissue culture cells by endpoint titration. However, its limit of detection is higher compared to a plaque assay. In this article, we describe a plaque assay protocol that can be used to effectively determine the number of infectious MNV particles present in biological or environmental samples. This method is based on the preparation of 10-fold serial dilutions of MNV-containing samples, which are used to inoculate a monolayer of permissive cells (RAW 264.7 murine macrophage cells). Virus is allowed to attach to the cell monolayer for a given period of time and then aspirated before covering cells with a mixture of agarose and cell culture media. The agar enables the spread of viral progeny to neighboring cells while limiting spread to distantly located cells. Consequently, infected cells are lysed and form holes in the monolayer known as plaques. Upon sufficient spread of virus, plaques become visible following staining of cells with dyes, like neutral red, methylene blue, or crystal violet. At low dilutions, each plaque originates from one infectious viral particle and its progeny, which spread to neighboring cells. Thus, counting the number of plaques allows one to calculate plaque-forming units (PFU) present in the undiluted sample. PMID:22951568
Gonzalez-Hernandez, Mariam B; Bragazzi Cunha, Juliana; Wobus, Christiane E
Imaging of the unstable plaque
Atherosclerosis is now considered a systemic inflammatory disorder affecting the arterial tree. Inflammation plays a role in all stages of the disease, from the initiation of the fatty streak to the final stage of plaque rupture. Atherosclerotic plaques that demonstrate the features of active inflammation are more likely to become symptomatic. In addition to having a higher risk of developing
Kiat Tsong Tan; Gregory Y. H. Lip
Routes to chemical plaque control
A logical approach to the prevention of periodontal disease is through excellent supragingival plaque control. Such control is not generally achieved by mechanical oral hygiene procedures alone. Thus, there is a clear rationale for the use of antiplaque agents to augment mechanical means. The principle routes to chemical plaque control are to prevent colonization of the tooth surface, to inhibit
D. Cummins
Denitrification in human dental plaque
BACKGROUND: Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate (NO3-) concentrations in the millimolar range and that dental plaque houses bacteria that
Frank Schreiber; Peter Stief; Armin Gieseke; Ines M Heisterkamp; Willy Verstraete; Dirk de Beer; Paul Stoodley
Plaque Assay for Rickettsia rickettsii
A plaque technique for the assay of Rickettsia rickettsii is described. The method employs primary chick or green monkey kidney monolayer cell cultures with either an agarose or special Noble agar overlay. Plaques were counted in 6 days and resultant titers correlated well with ld50 end points obtained by a standard assay in embryonated eggs. Identification of the plaque-forming organisms was accomplished by direct observation of rickettsiae-like bodies in the monolayer lesions, inhibition of plaques by antibiotics, sensitivity of plaques to specific immune serum, and failure to cultivate other microorganisms from the infected cells. Versatility of the test was demonstrated by assaying samples of rickettsiae from several different sources commonly used in our laboratory. These included infected yolk sacs, various cell cultures, and infected guinea pig tissue. Sufficient numbers of viable rickettsiae were present in the cells of a single lesion to permit direct recovery. Images
Weinberg, Edmund H.; Stakebake, Jack R.; Gerone, Peter J.
Dental plaque identification at home
... special tablets that contain a red dye that stains the plaque. One tablet is chewed thoroughly, moving ... this method is that it leaves no pink stains in the mouth. In the office, dentists are ...
Plaque removal with variable instrumentation.
The purpose of this study was to evaluate dental plaque removal in a normal healthy mouth, during routine oral hygiene appointments using different techniques and without the use of any disclosing agents. 12 dental hygienists, randomly selected from a continuing education course, were asked to perform oral hygiene on the same patient to remove all the supra-gingival plaque without any time restriction and without the use of a disclosing agents. The plaque index score (O'Leary) was assessed before and after each session with the use of fluorescine and UV light source by an independent examiner. 3 groups of instruments were utilized: group A: ultrasonic scalers + prophy cups; group B: ultrasonic scalers + prophy cups + dental floss; group C: Gracey curettes + prophy cups. While no group was able to remove all the plaque, groups B and C performed significantly better. PMID:9350554
Checchi, L; Forteleoni, G; Pelliccioni, G A; Loriga, G
Disappearance of La Caille Plaque
NASA Astrophysics Data System (ADS)
A bronze plaque erected to the memory of N.-L. de La Caille near the site of his observatory in Central Cape Town, has been stolen by metal thieves. It was designed by the famous architect Sir Herbert Baker.
Carotid endarterectomy for high plaques.
Seventeen instances of high plaque (plaque extending up to the level of the second cervical vertebra) were encountered out of a total of 454 carotid endarterectomies (3.7 percent). With careful dissection and knowledge of anatomy superior to hypoglossal nerve, carotid endarterectomy was accomplished without resorting to mandibular subluxation or dislocation. There was no operative mortality or perioperative strokes. One patient had perioperative myocardial infarction and another sustained temporary glossopharyngeal nerve dysfunction. High carotid plaques were more common in male patients with bilateral stenoses or contralateral internal carotid occlusion and could be suspected by findings of preoperative carotid arteriography in some instances. In the majority of cases, extension of high plaque in a tongue-shaped manner on the posterior wall of the internal carotid artery was an unexpected finding at the time of carotid endarterectomy. PMID:2929868
Hans, S S; Shah, S; Hans, B
Periodontal pathogens in atheromatous plaque.
Background: There has been increasing attention paid in recent years to the possibility that oral bacterial infection, particularly periodontal disease may influence the initiation and or progression of systemic diseases. These studies confirm the observation that heart disease is the most commonly found systemic condition in patients with periodontal disease. Moreover, the literature has also highlighted substantial evidence indicating the presence of Gram-negative periodontal pathogens in atheromatous plaques. Aim: This study intends to investigate the possible association between periodontal health and coronary artery disease by evaluating periodontal status, association between the periodontal plaque and coronary atheromatous plaques for presence of micro-organisms such as, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia. Materials and methods: A case-control study was designed with seven patients who had undergone coronary endarterectomy for cardiovascular disease and 28 controls. The periodontal examination for cases was performed 1 day before vascular surgery and the controls were clinically examined. The atheromatous plaque sample collected during endarterectomy and the intraoral plaque samples were subjected to polymerase chain reaction for identification of A. actinomycetemcomitans, P. gingivalis, P. intermedia and T. forsythia. Results: The presence of periodontal bacteria DNA in coronary atheromatous plaques and sub-gingival plaque samples of the same patients was confirmed by this study. CONCLUSION A correlation was established between putative bacteria contributing to atheromatous plaques and species associated with periodontal disease. One particularly important study to be carried out is the investigation of a possible clinically meaningful reduction in coronary heart disease resulting from the prevention or treatment of periodontal disease. PMID:24943760
Rath, Saroj K; Mukherjee, Manish; Kaushik, R; Sen, Sourav; Kumar, Mukesh
Recent concepts in plaque formation.
Dental plaque is an adherent, bacterial film, and is the main pathological agent for periodontal diseases. The formation of dental plaque can occur both supragingivally and subgingivally. The development of plaque is a three-step process. Following the formation of a pellicle, pioneer micro-organisms will adhere to it, proliferate and form colonies. The final stage involves the aggregation of filamentous organisms and spirochetes into a cohesive biofilm. Many products of the plaque bacteria reach the subepithelial tissue, causing inflammatory responses such as increased vascularity and leukocyte diapedesis. Both supragingival and subgingival plaque may form a hard, mineralized mass called calculus. The surface of calculus harbours bacteria, which may exacerbate the inflammatory responses. An effective oral antiseptic must be active against a wide range of Gram-positive and Gram-negative bacterial species, including streptococci and fusobacteria. Ideally, an effective agent would also penetrate the plaque biofilm. Data show that essential oil and chlorhexidine mouthwashes have the broadest antimicrobial effects. PMID:12787195
Bernimoulin, J-P
Plaque Assay for Murine Norovirus
Murine norovirus (MNV) is the only member of the Norovirus genus that efficiently grows in tissue culture 1, 2. Cell lysis and cytopathic effect (CPE) are observed during MNV-1 infection of murine dendritic cells or macrophages 1. This property of MNV-1 can be used to quantify the number of infectious particles in a given sample by performing a plaque assay 1. The plaque assay relies on the ability of MNV-1 to lyse cells and to form holes in a confluent cell monolayer, which are called plaques 3. Multiple techniques can be used to detect viral infections in tissue culture, harvested tissue, clinical, and environmental samples, but not all measure the number of infectious particles (e.g. qRT-PCR). One way to quantify infectious viral particles is to perform a plaque assay 3, which will be described in detail below. A variation on the MNV plaque assay is the fluorescent focus assay, where MNV antigen is immunostained in cell monolayers 4. This assay can be faster, since viral antigen expression precedes plaque formation. It is also useful for titrating viruses unable to form plaques. However, the fluorescent focus assay requires additional resources beyond those of the plaque assay, such as antibodies and a microscope to count focus-forming units. Infectious MNV can also be quantified by determining the 50% Tissue Culture Infective Dose (TCID50) 3. This assay measures the amount of virus required to produce CPE in 50% of inoculated tissue culture cells by endpoint titration 5. However, its limit of detection is higher compared to a plaque assay 4. In this article, we describe a plaque assay protocol that can be used to effectively determine the number of infectious MNV particles present in biological or environmental samples 1, 4, 6. This method is based on the preparation of 10-fold serial dilutions of MNV-containing samples, which are used to inoculate a monolayer of permissive cells (RAW 264.7 murine macrophage cells). Virus is allowed to attach to the cell monolayer for a given period of time and then aspirated before covering cells with a mixture of agarose and cell culture media. The agar enables the spread of viral progeny to neighboring cells while limiting spread to distantly located cells. Consequently, infected cells are lysed and form holes in the monolayer known as plaques. Upon sufficient spread of virus, plaques become visible following staining of cells with dyes, like neutral red, methylene blue, or crystal violet. At low dilutions, each plaque originates from one infectious viral particle and its progeny, which spread to neighboring cells. Thus, counting the number of plaques allows one to calculate plaque-forming units (PFU) present in the undiluted sample 3.
Gonzalez-Hernandez, Mariam B.; Bragazzi Cunha, Juliana; Wobus, Christiane E.
Effects of bacteriophage traits on plaque formation
Background The appearance of plaques on a bacterial lawn is one of the enduring imageries in modern day biology. The seeming simplicity of a plaque has invited many hypotheses and models in trying to describe and explain the details of its formation. However, until now, there has been no systematic experimental exploration on how different bacteriophage (phage) traits may influence the formation of a plaque. In this study, we constructed a series of isogenic ? phages that differ in their adsorption rate, lysis timing, or morphology so that we can determine the effects if these changes on three plaque properties: size, progeny productivity, and phage concentration within plaques. Results We found that the adsorption rate has a diminishing, but negative impact on all three plaque measurements. Interestingly, there exists a concave relationship between the lysis time and plaque size, resulting in an apparent optimal lysis time that maximizes the plaque size. Although suggestive in appearance, we did not detect a significant effect of lysis time on plaque productivity. Nonetheless, the combined effects of plaque size and productivity resulted in an apparent convex relationship between the lysis time and phage concentration within plaques. Lastly, we found that virion morphology also affected plaque size. We compared our results to the available models on plaque size and productivity. For the models in their current forms, a few of them can capture the qualitative aspects of our results, but not consistently in both plaque properties. Conclusions By using a collection of isogenic phage strains, we were able to investigate the effects of individual phage traits on plaque size, plaque productivity, and average phage concentration in a plaque while holding all other traits constant. The controlled nature of our study allowed us to test several model predictions on plaque size and plaque productivity. It seems that a more realistic theoretical approach to plaque formation is needed in order to capture the complex interaction between phage and its bacterium host in a spatially restricted environment.
Pathophysiology of atherosclerosis plaque progression.
Atherosclerotic plaque rupture with luminal thrombosis is the most common mechanism responsible for the majority of acute coronary syndromes and sudden coronary death. The precursor lesion of plaque rupture is thought to be a thin cap fibroatheroma (TCFA) or "vulnerable plaque". TCFA is characterised by a necrotic core with an overlying thin fibrous cap (?65 ?m) that is infiltrated by macrophages and T-lymphocytes. Intraplaque haemorrhage is a major contributor to the enlargement of the necrotic core. Haemorrhage is thought to occur from leaky vasa vasorum that invades the intima from the adventitia as the intima enlarges. The early atherosclerotic plaque progression from pathologic intimal thickening (PIT) to a fibroatheroma is thought to be the result of macrophage infiltration. PIT is characterised by the presence of lipid pools which consist of proteoglycan with lipid insudation. The conversion of the lipid pool to a necrotic core is poorly understood but is thought to occur as a result of macrophage infiltration which releases matrix metalloproteinase (MMPs) along with macrophage apoptosis that leads to the formation of a acellular necrotic core. The fibroatheroma has a thick fibrous cap that begins to thin over time through macrophage MMP release and apoptotic death of smooth muscle cells converting the fibroatheroma into a TCFA. Other causes of thrombosis include plaque erosion which is less frequent than plaque rupture but is a common cause of thrombosis in young individuals especially women <50 years of age. The underlying lesion morphology in plaque erosion consists of PIT or a thick cap fibroatheroma. Calcified nodule is the least frequent cause of thrombosis, which occurs in older individuals with heavily calcified and tortious arteries. PMID:23541627
Sakakura, Kenichi; Nakano, Masataka; Otsuka, Fumiyuki; Ladich, Elena; Kolodgie, Frank D; Virmani, Renu
An incisor plaque model in rats.
An in vivo model for studying plaque accumulation in rats has been described. This model investigates plaque formation on the mandibular incisors in animals which have been found to be rapid plaque-formers during a pre-test period. The accessibility of these tooth surfaces permits the removal of plaque prior to initiation of tests, the use of test groups balanced on the basis of plaque-forming potential, and interim assessments of plaque formation throughout the test period. In addition, baseline plaque scores of near zero can be attained, thereby permitting investigations of the impact of experimental measures on plaque formation. Moreover, the model permits intermittent plaque assessments throughout the test period. This model was found to have adequate sensitivity to distinguish effects between antimicrobial agents known to differ in their clinical activity and to detect differences between varying concentrations of the same agent. PMID:6582077
Schemehorn, B R; McDonald, J L; Stookey, G K; Park, K K
Denitrification in human dental plaque
Background Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate (NO3-) concentrations in the millimolar range and that dental plaque houses bacteria that can reduce this NO3- to nitrite (NO2-). Results We show that dental plaque mediates denitrification of NO3- to nitric oxide (NO), nitrous oxide (N2O), and dinitrogen (N2) using microsensor measurements, 15N isotopic labelling and molecular detection of denitrification genes. In vivo N2O accumulation rates in the mouth depended on the presence of dental plaque and on salivary NO3- concentrations. NO and N2O production by denitrification occurred under aerobic conditions and was regulated by plaque pH. Conclusions Increases of NO concentrations were in the range of effective concentrations for NO signalling to human host cells and, thus, may locally affect blood flow, signalling between nerves and inflammatory processes in the gum. This is specifically significant for the understanding of periodontal diseases, where NO has been shown to play a key role, but where gingival cells are believed to be the only source of NO. More generally, this study establishes denitrification by human-associated microbial communities as a significant metabolic pathway which, due to concurrent NO formation, provides a basis for symbiotic interactions.
Imaging Atherosclerosis and Vulnerable Plaque
Identifying patients at high risk for an acute cardiovascular event such as myocardial infarction or stroke and assessing the total atherosclerotic burden are clinically important. Currently available imaging modalities can delineate vascular wall anatomy and, with novel probes, target biologic processes important in plaque evolution and plaque stability. Expansion of the vessel wall involving remodeling of the extracellular matrix can be imaged, as can angiogenesis of the vasa vasorum, plaque inflammation, and fibrin deposits on early nonocclusive vascular thrombosis. Several imaging platforms are available for targeted vascular imaging to acquire information on both anatomy and pathobiology in the same imaging session using either hybrid technology (nuclear combined with CT) or MRI combined with novel probes targeting processes identified by molecular biology to be of importance. This article will discuss the current state of the art of these modalities and challenges to clinical translation.
Sadeghi, Mehran M.; Glover, David K.; Lanza, Gregory M.; Fayad, Zahi A.; Johnson, Lynne L.
Multiphoton microscopy of atheroslcerotic plaques
NASA Astrophysics Data System (ADS)
Multiphoton microscopy is a techniques that fascilitates three dimensional imaging of intact, unstained tissue. Especially connective tissue has a relatively strong nonlinear optical response and can easily be imaged. Atherosclerosis is a disease where lipids accumulate in the vessel wall and there is a thickening of the intima by growth of a cap of connective tissue. The mechanical strength of this fibrous cap is of clinically importance. If the cap ruptures a thrombosis forms which can block a coronary vessel and therby causing myocardial infarction. Multiphoton microscopy can be used to image the fibrous cap and thereby determine the thickness of the cap and the structure of the connective fibres. This could possibly be developed into a diagnostic and clincal tool to monitor the vulnerability of a plaque and also to better understand the development of a plaque and effects of treatment. We have collected multiphoton microscopy images from atherosclerotic plaque in human aorta, both two photon excited fluorescens and second harmonic generated signal. The feasability of using this technique to determine the state of the plaque is explored.
Lilledahl, Magnus B.; de Lange Davies, Catharina; Haugen, Olav A.; Svaasand, Lars O.
Laser-induced fluorescence of atherosclerotic plaques
NASA Astrophysics Data System (ADS)
In vitro laser-induced fluorescence (LIF) spectra and lifetimes of normal and atherosclerotic tissues are reported. The experimental arrangement conceived to measure LIF contained a 700 ps nitrogen pulsed laser (337.1 nm) and two quartz optical fibers to induce and respectively collect the fluorescence of normal and diseased samples. With UV laser excitation we found proeminent differences both in spectral and temporal range between normal artery and atherosclerotic plaques which was standard pathological classified in five types such as: normal artery, fibrous plaque, atherosclerotic plaque, calcified plaque and ulcerated plaque. As for statistics, the total number of measurements performed on each of the five mentioned types of tissues was 25.
Moise, N.; Pascu, Mihai L.; Carp, C.; Volvoreanu, C.
[Non plaque-related gingivitis].
Gingivitis is a symptom revealing an underlying pathology, mostly due to a bacterial accumulation. This explains why for dentists gingivitis is often synonymous of a plaque-related gingivitis. This is a dangerous simplification since it can be due to very different etiologies, which evidently imply very different treatments. This paper illustrates the most frequent causes, not only encountered by the periodontologist, but also by the general practitioner, such as erosive lichen planus, herpes, Candida and radiotherapy. PMID:12494701
van Steenberghe, D; Quirynen, M
The relevance of Randall's plaques
The pathophysiology of nephrolithiasis is not fully understood. The pioneering work of Alexander Randall in the 1940s sought to clarify our understanding of stone formation. This review traces the inception of the theory of Randall's plaques and the refinement of the hypothesis in the early days of kidney stone research. It then reviews the contemporary findings utilizing sophisticated investigative techniques that shed additional light on the pathophysiology and redefine the seminal findings of Dr. Randall that were made 70 years ago.
Strakosha, Ruth; Monga, Manoj; Wong, Michael Y. C.
Bacterial sex in dental plaque.
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. PMID:23741559
Olsen, Ingar; Tribble, Gena D; Fiehn, Nils-Erik; Wang, Bing-Yan
Gene therapy for the vulnerable plaque
Rupture of coronary atherosclerotic plaque and subsequent formation of an occlusive intracoronary thrombus (Figure 410-1)\\u000a are the major events precipitating acute coronary syndromes [1–6]. The vulnerable plaque is smaller in size [7], richer in lipids [1],[2], and more infiltrated with macrophages [2,3,8–10] than the stable, fibromuscular lesion. Therefore, lowering the lipid and\\/or macrophage pools stored in the plaque may "stabilize"
Douglas W. Losordo; Jeffrey M. Isner
Mechanisms of plaque formation and rupture.
Atherosclerosis causes clinical disease through luminal narrowing or by precipitating thrombi that obstruct blood flow to the heart (coronary heart disease), brain (ischemic stroke), or lower extremities (peripheral vascular disease). The most common of these manifestations is coronary heart disease, including stable angina pectoris and the acute coronary syndromes. Atherosclerosis is a lipoprotein-driven disease that leads to plaque formation at specific sites of the arterial tree through intimal inflammation, necrosis, fibrosis, and calcification. After decades of indolent progression, such plaques may suddenly cause life-threatening coronary thrombosis presenting as an acute coronary syndrome. Most often, the culprit morphology is plaque rupture with exposure of highly thrombogenic, red cell-rich necrotic core material. The permissive structural requirement for this to occur is an extremely thin fibrous cap, and thus, ruptures occur mainly among lesions defined as thin-cap fibroatheromas. Also common are thrombi forming on lesions without rupture (plaque erosion), most often on pathological intimal thickening or fibroatheromas. However, the mechanisms involved in plaque erosion remain largely unknown, although coronary spasm is suspected. The calcified nodule has been suggested as a rare cause of coronary thrombosis in highly calcified and tortious arteries in older individuals. To characterize the severity and prognosis of plaques, several terms are used. Plaque burden denotes the extent of disease, whereas plaque activity is an ambiguous term, which may refer to one of several processes that characterize progression. Plaque vulnerability describes the short-term risk of precipitating symptomatic thrombosis. In this review, we discuss mechanisms of atherosclerotic plaque initiation and progression; how plaques suddenly precipitate life-threatening thrombi; and the concepts of plaque burden, activity, and vulnerability. PMID:24902970
Bentzon, Jacob Fog; Otsuka, Fumiyuki; Virmani, Renu; Falk, Erling
Kyrieleis plaques in cytomegalovirus retinitis
Purpose The purpose of this study is to report a case of Kyrieleis plaques (segmental retinal periarteritis) associated with cytomegalovirus\\u000a (CMV) retinitis.\\u000a \\u000a \\u000a \\u000a \\u000a Methods A 47-year-old female with recently diagnosed human immunodeficiency virus and a CD4 count of 55 cells\\/µl presented with decreased\\u000a vision and floaters in her left eye. Ophthalmic examination revealed an advancing border of white granular CMV retinitis extending\\u000a into
Amar Patel; Matthew Pomykala; Krishna Mukkamala; Ronald C. Gentile
Objective To decipher the immunological mechanisms of plaque maturation and rupture, it is necessary to analyze the phenotypes and distribution of individual lymphocytes which migrate to the plaques as well as their activation at different stages of plaque formation. Methods and Results We developed a protocol to isolate plaque-residing immune cells and analyze their status using polychromatic flow cytometry. We found that the composition and phenotype of T lymphocytes in the plaques differs from that in blood. CD4 and, in particular, CD8+ T cells in plaques are highly activated; the fraction of CD8 T cells co-expressing CD25 and HLA-DR in plaques was 10 times larger than in blood. Conclusions The first flow-cytoanalysis of individual T cells in atherosclerotic plaques indicates that plaques represent a separate immunological compartment from blood with lymphocytes characterized by a high level of T cells activation, which is compatible with the presence of antigen(s) that trigger infiltration activation of these cells. The ability to isolate and characterize these cells may lead to the identification of such antigens.
Grivel, Jean-Charles; Ivanova, Oxana; Pinegina, Natalia; Blank, Paul S.; Shpektor, Alexander; Margolis, Leonid B.; Vasilieva, Elena
Amyloid plaques in PSAPP mice bind less metal than plaques in human Alzheimer's disease
Amyloid beta (A?) is the primary component of Alzheimer's disease (AD) plaques, a key pathological feature of the disease. Metal ions of zinc (Zn), copper (Cu), iron (Fe), and calcium (Ca) are elevated in human amyloid plaques and are thought to be involved in neurodegeneration. Transgenic mouse models of AD also exhibit amyloid plaques, but fail to exhibit the high
Andreana C. Leskovjan; Antonio Lanzirotti; Lisa M. Miller
Plaquing procedure for infectious hematopoietic necrosis virus
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.
Burke, J. A.; Mulcahy, D.
Current status of vulnerable plaque detection.
Critical coronary stenoses have been shown to contribute to only a minority of acute coronary syndromes (ACS) and sudden cardiac death. Autopsy studies have identified a subgroup of high-risk patients with disrupted vulnerable plaque and modest stenosis. Consequently, a clinical need exists to develop methods to identify these plaques prospectively before disruption and clinical expression of disease. Recent advances in invasive and noninvasive imaging techniques have shown the potential to identify these high-risk plaques. The anatomical characteristics of the vulnerable plaque such as thin cap fibroatheroma and lipid pool can be identified with angioscopy, high frequency intravascular ultrasound, intravascular MRI, and optical coherence tomography. Efforts have also been made to recognize active inflammation in high-risk plaques using intravascular thermography. Plaque chemical composition by measuring electromagnetic radiation using spectroscopy is also an emerging technology to detect vulnerable plaques. Noninvasive imaging with MRI, CT, and PET also holds the potential to differentiate between low and high-risk plaques. However, at present none of these imaging modalities are able to detect vulnerable plaque neither has been shown to definitively predict outcome. Nevertheless in contrast, there has been a parallel development in the physiological assessment of advanced atherosclerotic coronary artery disease. Thus recent trials using fractional flow reserve in patients with modest non flow-limiting stenoses have shown that deferral of PCI with optimal medical therapy in these patients is superior to coronary intervention. Further trials are needed to provide more information regarding the natural history of high-risk but non flow-limiting plaque to establish patient-specific targeted therapy and to refine plaque stabilizing strategies in the future. PMID:19670307
Sharif, Faisal; Murphy, Ross T
Fluoride bioavailability in saliva and plaque
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.
'High-risk' or 'vulnerable' plaques in the coronary arteries have characteristics that make them more prone to disruption and subsequent thrombosis – the mechanisms of most acute coronary syndromes (ACS). There are a number of imaging modalities that are capable of visualizing these features. This article discusses invasive modalities for identifying 'high-risk' plaque such as intravascular ultrasound, coronary angioscopy, optical coherence
Dmitry Nemirovsky
Advanced Techniques for MRI of Atherosclerotic Plaque
This review examines the state of the art in vessel wall imaging by MRI with an emphasis on the biomechanical assessment of atherosclerotic plaque. Three areas of advanced techniques are discussed. First, alternative contrast mechanisms, including susceptibility, magnetization transfer, diffusion and perfusion, are presented in regards to how they facilitate accurate determination of plaque constituents underlying biomechanics. Second, imaging technologies, including hardware and sequences, are reviewed in regards to how they provide the resolution and SNR necessary for determining plaque structure. Finally, techniques for combining MRI data into an overall assessment of plaque biomechanical properties, including wall shear stress and internal plaque strain, are presented. The paper closes with a discussion of the extent to which these techniques have been applied to different arteries commonly targeted by vessel wall MRI.
Kerwin, William S.; Canton, Gador
Osseous changes in meningioma en plaque.
Hyperostosis is the most common skull change associated with meningioma. Five hyperostosis cases of meningioma en plaque infiltrating the skull processed without previous decalcification of the bone tissue were investigated histologically and immunohistochemically with antibodies against somatostatin receptor 2A (SSR2A). Undecalcified bone biopsies embedded in methylmethacrylate and paraffin-embedded extraosseous tumor tissues were analyzed. All five cases were well-differentiated meningotheliomatous meningiomas en plaque according to the WHO classification of tumors and revealed areas of hyperosteoidosis. Furthermore, all five meningiomas en plaque presented strong positive reactions to antibodies against SSR2A in both the intraosseous and extraosseous tumor proliferates. In summary, similar morphological changes characterized by hyperosteoidosis were observed in a small cohort of meningioma en plaque associated with expression of SSR2A and reports in the literature of the histogenesis of hyperostosis in meningioma en plaque are discussed. PMID:21378343
Matschke, Jakob; Addo, Jasmine; Bernreuther, Christian; Zustin, Jozef
Summary Nt-pro BNP in unstable coronary artery disease. Introduction. The natriuretic peptides and, more recently, the N-terminal fragment of Brain Natriuretic Peptide (NT- proBNP) caused great interest both in monitoring cardiac insufficiency and in the risk stratification in acute coronary disease. Anyway, the knowledge of the mechanism of natriuretic peptides synthesis, release and regulation is still incomplete. Besides myocardial necrosis
M. Lotzniker; N. Covini; G. Re; S. Finazzi; C. Inserra; R. Pacifici; P. G. Zuccaro
Growth of necrotic cores in atherosclerotic plaque.
Plaques are fatty deposits that grow mainly in arteries and develop as a result of a chronic inflammatory response. Plaques are characterized as 'vulnerable' when they have large internal regions of necrosis and are heavily infiltrated by macrophages. The particular composition of a vulnerable plaque renders it susceptible to rupture, which releases thrombogenic agents into the bloodstream and can result in myocardial infarction. In this paper, we propose a mathematical model to predict the development of a plaque's necrotic core. By solving coupled reaction-diffusion equations for macrophages and dead cells, we focus on the joint effects of hypoxic cell death and chemoattraction to oxidized low-density lipoprotein (Ox-LDL), a molecule that is strongly linked to atherosclerosis. We do not model the mechanical properties of the plaque, its growth or rupture. Our model predicts cores that have approximately the right size and shape when compared to ultrasound images. Because our model is linear and autonomous, normal mode analysis and subsequent calculation of the smallest eigenvalue allow us to compute the times taken for the necrotic core to form. We find that the spatial distribution of Ox-LDL within the plaque determines not only the placement and size of cores, but their time of formation. Although plaques are biochemically complex, our study shows that certain aspects of their composition can be predicted and are, in fact, governed by simple physical models. PMID:21908792
Fok, Pak-Wing
[Chemical control of plaque: comparative review].
Plaque control can be achieved by mechanical means. Since plaque removal can be laborious and difficult, chemical agents became important adjuncts to traditional oral hygiene procedures. Chlorhexidine is one of the synthetic antiseptics that has a unique antiplaque effect and 0.2% chlorhexidine can achieve a practically complete plaque control. It has one negative effect namely an extrinsic brown-yellow staining. Listerine has proven its ability to reduce plaque and gingivitis in a moderate way. Hexetidine has a greater antiplaque effect in combination with zinc and can be compared with a 0.1% chlorhexidine. Povidone-iodine can not be used to keep plaque at low levels. Sanguinarine can reduce plaque accumulation when the toothpaste and mouthrinse are used together. H2O2 is an antiplaque agent but has some negative effects such as ulcerations... One can conclude that the use of a chemical agent cannot replace a good mechanical plaque control but is rather an adjunct to oral hygiene under certain conditions. PMID:1891629
Marechal, M
Comprehensive plaque assessment by coronary CT angiography.
Most acute coronary syndromes are caused by sudden luminal thrombosis due to atherosclerotic plaque rupture or erosion. Preventing such an event seems to be the only effective strategy to reduce mortality and morbidity of coronary heart disease. Coronary lesions prone to rupture have a distinct morphology compared with stable plaques, and provide a unique opportunity for noninvasive imaging to identify vulnerable plaques before they lead to clinical events. The submillimeter spatial resolution and excellent image quality of modern computed tomography (CT) scanners allow coronary atherosclerotic lesions to be detected, characterized, and quantified. Large plaque volume, low CT attenuation, napkin-ring sign, positive remodelling, and spotty calcification are all associated with a high risk of acute cardiovascular events in patients. Computation fluid dynamics allow the calculation of lesion-specific endothelial shear stress and fractional flow reserve, which add functional information to plaque assessment using CT. The combination of morphologic and functional characteristics of coronary plaques might enable noninvasive detection of vulnerable plaques in the future. PMID:24755916
Maurovich-Horvat, Pál; Ferencik, Maros; Voros, Szilard; Merkely, Béla; Hoffmann, Udo
Parvovirus (feline panleucopaenia virus) plaque formation.
A plaque assay was developed for feline parvovirus (FPV; feline panleucopaenia virus) in a feline embryo (FEmb) cell line. Higher numbers and larger diameter plaques were obtained with a) seeding rates of 0.7 X 10(5) and 1.5 X 10(5) cells cf. 3 X 10(5) and 6 X 10(5) cells/well of 35 mm diameter, b) synchronised cells infected at the G1-S interface cf. nonsynchronised cells and c) 5 to 6 days incubation post inoculation. The plaque assay was standardised by using serum deprivation for 24 hours to synchronize cells, a seeding rate of 1.5 X 10(5) cells/35 mm diameter well, inoculation of virus 16 hours post seeding followed by 5 days incubation. The standardised assay gave consistent, reproducible results. A dose-response curve using the assay showed a linear, 45 degrees slope, relationship between plaque forming units and virus dilution which further verified the sensitivity and reliability of the assay. Plaques produced by "wild" type and plaque purified virus were invariably non uniform in diameter; diameter of plaques in fact followed a normal frequency distribution under standard assay conditions. PMID:2986580
Tham, K M; Studdert, M J
A modified COMS plaque for iris melanoma
Melanoma of the iris is a rare condition compared to posterior ocular tumors and in this case report we present a 51-year-old female patient with diffuse iris melanoma. Traditional COMS (Collaborative Ocular Melanoma Study) plaques are used at our institution for radiation therapy, so a novel modification of the traditional plaque was required to allow better conformance with placement on the cornea. The usual silastic insert was machined to dimensions in compliance with the cornea, placed without incident, and treatment delivered with excellent patient tolerance of the modified plaque.
Vasudev, Deepta; Rice, Roger K.; Goldbaum, Michael; Mundt, Arno J.
Retinal arterial wall plaques in Susac syndrome
PurposeTo demonstrate retinal arterial wall plaques (RAWPs) in patients with Susac syndrome, a disorder that consists of the triad of branch retinal artery occlusion, encephalopathy, and hearing loss. The clinician may misinterpret these RAWPs as emboli.
Robert A Egan; Thuy Ha Nguyen; J. Donald M Gass; Joseph F Rizzo III; John Tivnan; John O Susac
Symptomatic and asymptomatic carotid artery plaque
Carotid atherosclerotic plaques represent both stable and unstable atheromatous lesions. Atherosclerotic plaques that are prone to rupture owing to their intrinsic composition such as a large lipid core, thin fibrous cap and intraplaque hemorrhage are associated with subsequent thromboembolic ischemic events. At least 15–20% of all ischemic strokes are attributable to carotid artery atherosclerosis. Characterization of plaques may enhance the understanding of natural history and ultimately the treatment of atherosclerotic disease. MRI of carotid plaque and embolic signals during transcranial Doppler have identified features beyond luminal stenosis that are predictive of future transient ischemic attacks and stroke. The value of specific therapies to prevent stroke in symptomatic and asymptomatic patients with severe carotid artery stenosis are the subject of current research and analysis of recently published clinical trials that are discussed in this article.
Mughal, Majid M; Khan, Mohsin K; DeMarco, J Kevin; Majid, Arshad; Shamoun, Fadi; Abela, George S
Historical Plaque at Marshall Space Flight Center
NASA Technical Reports Server (NTRS)
This plaque, located on the grounds of Marshall Space Flight Center in Huntsville, Alabama,commemorates the designation of the Saturn V Rocket as a National Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers in 1980.
Historical Plaque at Marshall Space Flight Center
NASA Technical Reports Server (NTRS)
This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Redstone Test Stand as an Alabama Historic Civil Engineering Landmark. The site was desinated as such in 1979.
Tissue characterisation of atherosclerotic carotid plaques by MRI
Carotid artery plaques with intraplaque haemorrhage or atheromatous debris have been found to be associated with an increased risk of embolic stroke. Other methods have failed to detect plaque morphology, and it is not clear whether MRI allows differentiation between prognostically and therapeutically relevant plaque types. We examined 17 carotid bifurcation plaques which had been removed in toto by MRI.
M. Giirtler; A. Goldmann; W. Mohr; B. Widder
A new inexpensive customized plaque for choroidal melanoma iodine-125 plaque therapy
The authors have developed a new inexpensive precious metal alloy plaque for use in customized iodine-125 plaque therapy. Each plaque is formed from two flat circular gold/palladium foils which are used in dental crown work. Using a simple manual mechanism, the two forms are stamped over a customized acrylic die shaped to the dimensions of the tumor base plus a 2-mm margin. Completed plaques consist of a back wall, a 2-mm side wall, and a 1.5-mm wide lip with holes for suture placement. Advantages include: simple construction from inexpensive components, customized shape, and iodine seeds that are readily visible on plane radiographs.
Vine, A.K.; Tenhaken, R.K.; Diaz, R.F.; Maxson, B.B.; Lichter, A.S.
Carotid Plaque Age Is a Feature of Plaque Stability Inversely Related to Levels of Plasma Insulin
Background The stability of atherosclerotic plaques determines the risk for rupture, which may lead to thrombus formation and potentially severe clinical complications such as myocardial infarction and stroke. Although the rate of plaque formation may be important for plaque stability, this process is not well understood. We took advantage of the atmospheric 14C-declination curve (a result of the atomic bomb tests in the 1950s and 1960s) to determine the average biological age of carotid plaques. Methodology/Principal Finding The cores of carotid plaques were dissected from 29 well-characterized, symptomatic patients with carotid stenosis and analyzed for 14C content by accelerator mass spectrometry. The average plaque age (i.e. formation time) was 9.6±3.3 years. All but two plaques had formed within 5–15 years before surgery. Plaque age was not associated with the chronological ages of the patients but was inversely related to plasma insulin levels (p?=?0.0014). Most plaques were echo-lucent rather than echo-rich (2.24±0.97, range 1–5). However, plaques in the lowest tercile of plaque age (most recently formed) were characterized by further instability with a higher content of lipids and macrophages (67.8±12.4 vs. 50.4±6.2, p?=?0.00005; 57.6±26.1 vs. 39.8±25.7, p<0.0005, respectively), less collagen (45.3±6.1 vs. 51.1±9.8, p<0.05), and fewer smooth muscle cells (130±31 vs. 141±21, p<0.05) than plaques in the highest tercile. Microarray analysis of plaques in the lowest tercile also showed increased activity of genes involved in immune responses and oxidative phosphorylation. Conclusions/Significance Our results show, for the first time, that plaque age, as judge by relative incorporation of 14C, can improve our understanding of carotid plaque stability and therefore risk for clinical complications. Our results also suggest that levels of plasma insulin might be involved in determining carotid plaque age.
Hagg, Sara; Salehpour, Mehran; Noori, Peri; Lundstrom, Jesper; Possnert, Goran; Takolander, Rabbe; Konrad, Peter; Rosfors, Stefan; Ruusalepp, Arno; Skogsberg, Josefin; Tegner, Jesper; Bjorkegren, Johan
Collagenases and cracks in the plaque
The core of an atheromatous plaque contains lipids, macrophages, and cellular debris, typically covered by a fibrous cap that separates the thrombogenic core from the blood. Rupture of the fibrous cap causes most fatal myocardial infarctions. Interstitial collagen confers tensile strength on the cap, as it does in skin and tendons. In 1994, Peter Libby and colleagues demonstrated overexpression of collagenolytic enzymes in atheromatous plaques and implicated MMPs in the destabilization of these lesions.
Libby, Peter
Detection of High-Risk Atherosclerotic Plaque
The leading cause of major morbidity and mortality in most countries around the world is atherosclerotic cardiovascular disease, most commonly caused by thrombotic occlusion of a high-risk coronary plaque resulting in myocardial infarction or cardiac death, or embolization from a high-risk carotid plaque resulting in stroke. The lesions prone to result in such clinical events are termed vulnerable or high-risk plaques, and their identification may lead to the development of pharmacological and mechanical intervention strategies to prevent such events. Autopsy studies from patients dying of acute myocardial infarction or sudden death have shown that such events typically arise from specific types of atherosclerotic plaques, most commonly the thin-cap fibroatheroma. However, the search in human beings for vulnerable plaques before their becoming symptomatic has been elusive. Recently, the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study demonstrated that coronary plaques that are likely to cause future cardiac events, regardless of angiographic severity, are characterized by large plaque burden and small lumen area and/or are thin-cap fibroatheromas verified by radiofrequency intravascular ultrasound imaging. This study opened the door to identifying additional invasive and noninvasive imaging modalities that may improve detection of high-risk atherosclerotic lesions and patients. Beyond classic risk factors, novel biomarkers and genetic profiling may identify those patients in whom noninvasive imaging for vulnerable plaque screening, followed by invasive imaging for risk confirmation is warranted, and in whom future pharmacological and/or device-based focal or regional therapies may be applied to improve long-term prognosis.
Fleg, Jerome L.; Stone, Gregg W.; Fayad, Zahi A.; Granada, Juan F.; Hatsukami, Thomas S.; Kolodgie, Frank D.; Ohayon, Jacques; Pettigrew, Roderic; Sabatine, Marc S.; Tearney, Guillermo; Waxman, Sergio; Domanski, Michael J.; Srinivas, Pothur R.; Narula, Jagat
Studies of the Rickettsial Plaque Assay Technique
A plaque assay system for pathogenic rickettsiae, which utilizes primary chick embryo tissue cultures, is described. It proved to be a highly reproducible measure of infectiousness for Rickettsia rickettsi and R. typhi, which were employed in most studies; as well as for R. canada, R. prowazeki, R. sibirica, R. akari, R. conori, and Coxiella burneti. Plaque-forming units (PFU) were compared to direct rickettsial counts and to 50% infectious dose (ID50) values for embryonated eggs, mice, and guinea pigs. Plaque size, appearance, and number were influenced by diluent, incubation temperature after nutrient overlay, centrifugation of inoculated tissue cultures, and number of host cells planted initially in each flask. The most critical factors in plaque formation were diluent used in making rickettsial suspensions and incubation temperature (32 C) after nutrient overlay. Brain Heart Infusion was the only diluent capable of preventing significant delay in plaque formation and decreases in PFU and mouse ID50. Plaque formation was unaffected by genetic background of host cells, volume of inoculum, temperature and length of incubation period before nutrient overlay, and rapid freezing and thawing of rickettsial seed. Centrifugation of inoculated cultures at 600 × g resulted in 100% irreversible absorption of rickettsiae to host cells within 5 min, whereas without centrifugation at least 4 hr was required to achieve the same effect. Images
Wike, David A.; Tallent, George; Peacock, Marius G.; Ormsbee, Richard A.
Studies of the rickettsial plaque assay technique.
A plaque assay system for pathogenic rickettsiae, which utilizes primary chick embryo tissue cultures, is described. It proved to be a highly reproducible measure of infectiousness for Rickettsia rickettsi and R. typhi, which were employed in most studies; as well as for R. canada, R. prowazeki, R. sibirica, R. akari, R. conori, and Coxiella burneti. Plaque-forming units (PFU) were compared to direct rickettsial counts and to 50% infectious dose (ID(50)) values for embryonated eggs, mice, and guinea pigs. Plaque size, appearance, and number were influenced by diluent, incubation temperature after nutrient overlay, centrifugation of inoculated tissue cultures, and number of host cells planted initially in each flask. The most critical factors in plaque formation were diluent used in making rickettsial suspensions and incubation temperature (32 C) after nutrient overlay. Brain Heart Infusion was the only diluent capable of preventing significant delay in plaque formation and decreases in PFU and mouse ID(50). Plaque formation was unaffected by genetic background of host cells, volume of inoculum, temperature and length of incubation period before nutrient overlay, and rapid freezing and thawing of rickettsial seed. Centrifugation of inoculated cultures at 600 x g resulted in 100% irreversible absorption of rickettsiae to host cells within 5 min, whereas without centrifugation at least 4 hr was required to achieve the same effect. PMID:4629250
Wike, D A; Tallent, G; Peacock, M G; Ormsbee, R A
Molecular mechanisms and therapeutic strategies of vulnerable atherosclerotic plaques
Vulnerable atherosclerotic plaque rupture leading to thrombosis is the major cause of acute coronary syndrome (ACS). Studies\\u000a on the pathophysiologic mechanism of both ACS and plaque stabilizing treatment are driving the development of animal models\\u000a of vulnerable plaque. In our laboratory, we established animal models of plaque rupture and thrombosis in rabbits and mice\\u000a that are similar to human plaque
Wen-Qiang Chen; Yun Zhang
Stone Morphology Suggestive of Randall's Plaque
NASA Astrophysics Data System (ADS)
Randall's plaques are found in a number of calcium oxalate stone formers. Stones developed on a Randall's plaque typically present a small depressed zone (``umbilication'') corresponding to the tip of the papilla and containing material detached from the plaque. By examining the morphology and infrared composition of 45,774 calculi referred to our laboratory over the past three decades, we identified 8,916 umbilicated calculi (19.5%). We have selected three periods of time corresponding to the first years of each decade. Over these periods, we analyzed 26,182 consecutive calculi. Among them, we identified 5,401 umbilicated calculi, of which 91.5% had an identifiable plaque. We analyzed the relative prevalence of umbilicated stones over time and the respective composition of Randall's plaque and stones. The proportion of umbilicated stones rose significantly from 10% in period 1 (1978-1984) to 21% in period 2 (1990-1993) and 22.2% in period 3 (2000-2006), with a parallel rise in the prevalence of stones with identifiable Randall's plaque. The main component of plaques was carbapatite in 90.8% of cases, whereas other components such as amorphous carbonated calcium phosphate, sodium hydrogen urate or uric acid were found in other cases. The morphology of plaques made of carbapatite was diverse, as was their carbonate content, thus suggesting variable pathophysiological mechanisms. Stones were made of whewellite as the main component in 51.4% of cases, or admixed with weddellite in 26.8%, predominant weddellite in 12.5% and other components (mainly uric acid) in 7.5% of cases. Our findings confirm that Randall's plaques are made of carbapatite in the great majority of cases, but with the stones more frequently composed of calcium oxalate monohydrate (which is associated with hyperoxaluria) than of calcium oxalate dihydrate (associated with hypercalciuria). In conclusion, in our country, stones developed on a carbapatite Randall's plaque are as frequently made of monohydrate than dihydrate calcium oxalate, thus suggesting a role for a high urine concentration in both oxalate and calcium ions in the lithogenic process.
Daudon, Michel; Traxer, Olivier; Jungers, Paul; Bazin, Dominique
Amyloid Plaques in PSAPP Mice Bind Less Metal than Plaques in Human Alzheimer's Disease
Amyloid beta (A?) is the primary component of Alzheimer's disease (AD) plaques, a key pathological feature of the disease. Metal ions of zinc (Zn), copper (Cu), iron (Fe), and calcium (Ca) are elevated in human amyloid plaques and are thought to be involved in neurodegeneration. Transgenic mouse models of AD also exhibit amyloid plaques, but fail to exhibit the high degree of neurodegeneration observed in humans. In this study, we imaged the Zn, Cu, Fe, and Ca ion distribution in the PSAPP transgenic mouse model representing end-stage AD (N = 6) using synchrotron X-ray fluorescence (XRF) microprobe. In order to account for differences in density in the plaques, the relative protein content was imaged with synchrotron Fourier transform infrared microspectroscopy (FTIRM) on the same samples. FTIRM results revealed a 61% increase in protein content in the plaques compared to the surrounding tissue. After normalizing to protein density, we found that the PSAPP plaques contained only a 29% increase in Zn and there was actually less Cu, Fe, and Ca in the plaque compared to the surrounding tissue. Since metal-binding to A? is thought to induce redox chemistry that is toxic to neurons, the reduced metal-binding in PSAPP mice is consistent with the lack of neurodegeneration in these animals. These findings were in stark contrast to the high metal ion content observed in human AD plaques, further implicating the role of metal ions in human AD pathology.
Leskovjan, Andreana C.; Lanzirotti, Antonio; Miller, Lisa M.
Thermal detection of cellular infiltrates in living atherosclerotic plaques: possible implications for plaque rupture and thrombosis
SummaryBackground Atherosclerotic lesions are heterogeneous and prognosis cannot easily be predicted, even with intracoronary ultrasound and angioscopy. Serial angiographic and necropsy studies suggest that the risk of plaque rupture correlates only weakly with the degree of stenosis. Most ruptured plaques are characterised by a large pool of cholesterol or necrotic debris and a thin fibrous cap with a dense infiltration
W. Casscells; W. K. Vaughn; H. McAllister; J. T. Willerson; B. Hathorn; M. David; T. Krabach; G. Bearman
A plaque-specific antibody clears existing ?-amyloid plaques in Alzheimer's disease mice.
A? Immunotherapy is a promising therapeutic approach for Alzheimer's disease. Preclinical studies demonstrate that plaque prevention is possible; however, the more relevant therapeutic removal of existing plaque has proven elusive. Monoclonal antibodies in development target both soluble and insoluble A? peptide. We hypothesized that antibody specificity for deposited plaque was critical for plaque removal since soluble A? peptide would block recognition of deposited forms. We developed a plaque-specific antibody that targets a modified A? peptide (A?(p3-42)), which showed robust clearance of pre-existing plaque without causing microhemorrhage. Interestingly, a comparator N-terminal A? antibody 3D6, which binds both soluble and insoluble A?(1-42), lacked efficacy for lowering existing plaque but manifested a significant microhemorrhage liability. Mechanistic studies suggested that the lack of efficacy for 3D6 was attributed to poor target engagement in plaques. These studies have profound implications for the development of therapeutic A? antibodies for Alzheimer's disease. PMID:23217740
Demattos, Ronald B; Lu, Jirong; Tang, Ying; Racke, Margaret M; Delong, Cindy A; Tzaferis, John A; Hole, Justin T; Forster, Beth M; McDonnell, Peter C; Liu, Feng; Kinley, Robert D; Jordan, William H; Hutton, Michael L
Localized pleural plaques and lung cancer
In a mass chest radiography survey conducted in 1971 for 7,986 residents of three Finnish communities, 604 subjects (7.6%) with pleural plaques but not other asbestos-related radiographic signs were identified. The same number of referents, each individually matched to each plaque carrier on sex, birth year, and community, was selected from among persons in the same source population with no pleural plaques. The two groups were followed for investigation of incidence of lung cancer during 1972-1989. Twenty-eight of those with plaques and 25 referents contracted lung cancer (crude conditional RR = 1.1; CL95 = 0.7, 1.9). The application of the proportional hazards model, with adjustment for sex, age, and residence, resulted in a hazard ratio of 1.1 (CL = 0.6, 1.8). The risk ratio estimate may be biased; hence, the result is inconclusive in regard to the predictive assessment of lung cancer risk among carriers of pleural plaques.
Partanen, T.; Nurminen, M.; Zitting, A.; Koskinen, H.; Wiikeri, M.; Ahlman, K. (Department of Epidemiology and Biostatistics, Institute of Occupational Health, Helsinki (Finland))
Hyperspectral imaging of atherosclerotic plaques in vitro
NASA Astrophysics Data System (ADS)
Vulnerable plaques constitute a risk for serious heart problems, and are difficult to identify using existing methods. Hyperspectral imaging combines spectral- and spatial information, providing new possibilities for precise optical characterization of atherosclerotic lesions. Hyperspectral data were collected from excised aorta samples (n = 11) using both white-light and ultraviolet illumination. Single lesions (n = 42) were chosen for further investigation, and classified according to histological findings. The corresponding hyperspectral images were characterized using statistical image analysis tools (minimum noise fraction, K-means clustering, principal component analysis) and evaluation of reflectance/fluorescence spectra. Image analysis combined with histology revealed the complexity and heterogeneity of aortic plaques. Plaque features such as lipids and calcifications could be identified from the hyperspectral images. Most of the advanced lesions had a central region surrounded by an outer rim or shoulder-region of the plaque, which is considered a weak spot in vulnerable lesions. These features could be identified in both the white-light and fluorescence data. Hyperspectral imaging was shown to be a promising tool for detection and characterization of advanced atherosclerotic plaques in vitro. Hyperspectral imaging provides more diagnostic information about the heterogeneity of the lesions than conventional single point spectroscopic measurements.
Larsen, Eivind L. P.; Randeberg, Lise L.; Olstad, Elisabeth; Haugen, Olav A.; Aksnes, Astrid; Svaasand, Lars O.
Assessment of vulnerable plaque composition by matching the deformation of a parametric plaque model to measured plaque deformation.
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. PMID:15822809
Baldewsing, Radj A; Schaar, Johannes A; Mastik, Frits; Oomens, Cees W J; van der Steen, Antonius F W
Infliximab for the treatment of plaque psoriasis
Infliximab is a monoclonal antibody that targets tumor necrosis factor-? (TNF?). It is used in the treatment of a number of inflammatory disorders including severe plaque psoriasis. TNF? is thought to have a major role in psoriasis by promoting an inflammatory infiltrate into the skin and inducing keratinocyte proliferation and preventing keratinocyte apoptosis, which directly contributes to the characteristic plaque skin lesions. Based on four randomized, placebo-controlled, double-blind clinical trials and nine open-label uncontrolled trials of the use of infliximab in plaque psoriasis, it was found that infliximab is a highly efficacious, rapid, sustainable, and relatively safe therapy. Yet as with any biologic, caution is recommended in its use as infusion reactions, lupus-like syndromes, infections, malignancies including lymphomas, as well as other rare events have been reported.
Gall, Jennifer S; Kalb, Robert E
Visualizing the atherosclerotic plaque: a chemical perspective.
Atherosclerosis is the major underlying pathologic cause of coronary artery disease. An early detection of the disease can prevent clinical sequellae such as angina, myocardial infarction, and stroke. The different imaging techniques employed to visualize the atherosclerotic plaque provide information of diagnostic and prognostic value. Furthermore, the use of contrast agents helps to improve signal-to-noise ratio providing better images. For nuclear imaging techniques and optical imaging these agents are absolutely necessary. We report on the different contrast agents that have been used, are used or may be used in future in animals, humans, or excised tissues for the distinct imaging modalities for atherosclerotic plaque imaging. PMID:24526041
Teresa Albelda, Ma; Garcia-Espańa, Enrique; Frias, Juan C
Dobesilate in the treatment of plaque psoriasis.
Fibroblast growth factor (FGF)-mediated pathways participate in many of the cellular events implicated in the pathogenesis of psoriasis. Thus, targeting FGF signals may be potentially therapeutic in the treatment of psoriasis. We report for the first time on a 43-year-old man with chronic-type plaque psoriasis with a daily topical treatment of dobesilate, a new FGF inhibitor. As early as at day 14, the patient had cleared or achieved excellent improvement of psoriatic skin lesions. Topical dobesilate offers the potential for treatment of plaque psoriasis without atrophy or other local side effects associated with the use of topical corticosteroids. PMID:16183548
Cuevas, Pedro; Arrazola, Jose M
Assessment of vulnerable plaque composition by matching the deformation of a parametric plaque model to measured plaque deformation
Intravascular ultrasound (IVUS) elastography visualizes local radial strain of arteries in so-called elastograms to detect rupture-prone plaques. However, due to the unknown arterial stress distribution these elastograms cannot be directly interpreted as a morphology and material composition image. To overcome this limitation we have developed a method that reconstructs a Young's modulus image from an elastogram. This method is especially
Radj A. Baldewsing; Johannes A. Schaar; Frits Mastik; Cees. W. J. Oomens; Antonius F. W. van der Steen
This study examined whether the practice of incorporating either tetrazolium red ortetrazolium violet dye into plaque assay medium deleteriously influences plaque assay titers. epresentative members of six different virus families were studied: ystoviridae (06), Leviviridae (MS2)...
Enumeration of bacteriophages by the direct plating plaque assay.
A method is described for determination of the concentration of infectious phage particles by the direct plating plaque assay, which is simpler and faster than the double agar overlay plaque procedure outlined in the previous chapter. PMID:19066812
Mazzocco, Amanda; Waddell, Thomas E; Lingohr, Erika; Johnson, Roger P
Improved treatment planning for COMS eye plaques
Purpose: A recent reanalysis of the Collaborative Ocular Melanoma Study (COMS) medium tumor trial concluded that incorporating factors to account for anisotropy, line source approximation, the gold plaque, and attenuation in the Silastic seed carrier into the dose calculations resulted in a significant and consistent reduction of calculated doses to structures of interest within the eye. The authors concluded that
Melvin A. Astrahan
Is silica involved in neuritic (senile) plaque formation?
The agent responsible for inducing neuritic (senile) plaque formation in senile dementia of the Alzheimer's type and in the ageing non-demented brain is unknown. Other workers have detected a high concentration of silicon in the rims and cores of senile neuritic plaques. We have therefore looked at whether the reaction of brain tissue to silica particles resembles a neuritic plaque.
S. Reesl; B. Cragg
Three-Dimensional Ultrasound Observation of Carotid Artery Plaque Ulceration
Background and Purpose—Carotid artery plaque ulceration is associated with an increased risk of cerebral embolism. However, because of the rather poor diagnostic quality of conventional 2-D ultrasound and angiography compared with the evaluation of pathological specimens, little information exists on the natural course of carotid plaque ulceration. Recently, the introduction of 3-D ultrasound has made reproducible investigation of plaque morphology
Ulf Schminke; Lillian Motsch; Lutz Hilker; Christof Kessler
In vivo imaging reveals sigmoidal growth kinetic of ?-amyloid plaques.
A major neuropathological hallmark of Alzheimer's disease is the deposition of amyloid plaques in the brains of affected individuals. Amyloid plaques mainly consist of fibrillar ?-amyloid, which is a cleavage product of the amyloid precursor protein. The amyloid-cascade-hypothesis postulates A? accumulation as the central event in initiating a toxic cascade leading to Alzheimer's disease pathology and, ultimately, loss of cognitive function. We studied the kinetics of ?-amyloid deposition in Tg2576 mice, which overexpress human amyloid precursor protein with the Swedish mutation. Utilizing long-term two-photon imaging we were able to observe the entire kinetics of plaque growth in vivo. Essentially, we observed that plaque growth follows a sigmoid-shaped curve comprising a cubic growth phase, followed by saturation. In contrast, plaque density kinetics exhibited an asymptotic progression. Taking into account the fact that a critical concentration of A? is required to seed new plaques, we can propose the following kinetic model of ?-amyloid deposition in vivo. In the early cubic phase, plaque growth is not limited by A? concentration and plaque density increases very fast. During the transition phase, plaque density stabilizes whereas plaque volume increases strongly reflecting a robust growth of the plaques. In the late asymptotic phase, A? peptide production becomes rate-limiting for plaque growth. In conclusion, the present study offers a direct link between in vitro and in vivo studies facilitating the translation of A?-lowering strategies from laboratory models to patients. PMID:24678659
Burgold, Steffen; Filser, Severin; Dorostkar, Mario M; Schmidt, Boris; Herms, Jochen
Correlation of hemodynamic forces and atherosclerotic plaque components
NASA Astrophysics Data System (ADS)
Local hemodynamic forces in atherosclerotic carotid arteries are thought to trigger cellular and molecular mechanisms that determine plaque vulnerability. Magnetic Resonance Imaging (MRI) has emerged as a powerful tool to characterize human carotid atherosclerotic plaque composition and morphology, and to identify plaque features shown to be key determinants of plaque vulnerability. Image-based computational fluid dynamics (CFD) has allowed researchers to obtain time-resolved wall shear stress (WSS) information for atherosclerotic carotid arteries. A deeper understanding of the mechanisms of initiation and progression of atherosclerosis can be obtained through the comparison of WSS and plaque composition. The aim of this study was to explore the hypothesis that intra-plaque hemorrhage, a feature associated with adverse outcomes and plaque progression, is more likely to occur in plaques with elevated WSS levels. We compared 2D representations of the WSS distribution and the amount of intra-plaque hemorrhage to determine relationships between WSS patterns and plaque vulnerability. We extracted WSS data to compare patterns between cases with and without hemorrhage. We found elevated values of WSS at regions where intra-plaque hemorrhage was detected, suggesting that WSS might be used as a marker for the risk of intra-plaque hemorrhage and subsequent complications.
Canton, Gádór; Chiu, Bernard; Yuan, Chun; Kerwin, William S.
Fluorescence lifetime imaging microscopy for the characterization of atherosclerotic plaques
Atherosclerotic plaque composition has been associated with plaque instability and rupture. This study investigates the use of fluorescence lifetime imaging microscopy (FLIM) for mapping plaque composition and assessing features of vulnerability. Measurements were conducted in atherosclerotic human aortic samples using an endoscopic FLIM system (spatial resolution of 35 µm; temporal resolution 200 ps) developed in our lab which allows mapping
Jennifer Phipps; Yinghua Sun; Ramez Saroufeem; Nisa Hatami; Laura Marcu
Intravascular Modalities for Detection of Vulnerable Plaque Current Status
Progress in the diagnosis, treatment, and prevention of atherosclerotic coronary artery disease is dependent on a greater understanding of the mechanisms of coronary plaque progression. Autopsy studies have characterized a subgroup of high-risk, or vulnerable, plaques that result in acute coronary syndromes or sudden cardiac death. These angiographically modest plaques share certain pathologic characteristics: a thin, fibrous cap, lipid-rich core,
Briain D. MacNeill; Harry C. Lowe; Masamichi Takano; Valentin Fuster; Ik-Kyung Jang
In vivo imaging reveals sigmoidal growth kinetic of ?-amyloid plaques
A major neuropathological hallmark of Alzheimer's disease is the deposition of amyloid plaques in the brains of affected individuals. Amyloid plaques mainly consist of fibrillar ?-amyloid, which is a cleavage product of the amyloid precursor protein. The amyloid-cascade-hypothesis postulates A? accumulation as the central event in initiating a toxic cascade leading to Alzheimer's disease pathology and, ultimately, loss of cognitive function. We studied the kinetics of ?-amyloid deposition in Tg2576 mice, which overexpress human amyloid precursor protein with the Swedish mutation. Utilizing long-term two-photon imaging we were able to observe the entire kinetics of plaque growth in vivo. Essentially, we observed that plaque growth follows a sigmoid-shaped curve comprising a cubic growth phase, followed by saturation. In contrast, plaque density kinetics exhibited an asymptotic progression. Taking into account the fact that a critical concentration of A? is required to seed new plaques, we can propose the following kinetic model of ?-amyloid deposition in vivo. In the early cubic phase, plaque growth is not limited by A? concentration and plaque density increases very fast. During the transition phase, plaque density stabilizes whereas plaque volume increases strongly reflecting a robust growth of the plaques. In the late asymptotic phase, A? peptide production becomes rate-limiting for plaque growth. In conclusion, the present study offers a direct link between in vitro and in vivo studies facilitating the translation of A?-lowering strategies from laboratory models to patients.
Videocapillaroscopic Findings in the Microcirculation of the Psoriatic Plaque
Background: Videocapillaroscopy (VCP) is a method to study the morphology and dynamics of microcirculation, but information about capillaroscopic features of the psoriatic plaque is limited. Objective: To investigate the distribution, morphology and density of capillaries in lesional and perilesional skin of the psoriatic plaque. Methods: VCP of a well-delimited plaque of the trunk, arms or legs in 15 consecutive patients
Rossella De Angelis; Leonardo Bugatti; Patrizia Del Medico; Massimiliano Nicolini; Giorgio Filosa
Influence of microcalcifications on vulnerable plaque mechanics using FSI modeling
Sudden heart attacks remain one of the primary causes of premature death in the developed world. Asymptomatic vulnerable plaques that rupture are believed to prompt such fatal heart attacks and strokes. The role of microcalcifications in the vulnerable plaque rupture mechanics is still debated. Recent studies suggest the microcalcifications increase the plaque vulnerability. In this manuscript we present a numerical
Danny Bluestein; Yared Alemu; Idit Avrahami; Morteza Gharib; Kris Dumont; John J. Ricotta; Shmuel Einav
The Effect of pH, Temperature and Plaque Thickness on the Hydrolysis of Monofluorophosphate in Experimental Dental Plaque
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 ?8
E. I. F. Pearce; G. H. Dibdin
Simple Method for Plating Escherichia coli Bacteriophages Forming Very Small Plaques or No Plaques under Standard Conditions
The use of low concentrations (optimally 2.5 to 3.5 g\\/ml, depending on top agar thickness) of ampicillin in the bottom agar of the plate allows for formation of highly visible plaques of bacteriophages which otherwise form extremely small plaques or no plaques on Escherichia coli lawns. Using this method, we were able to obtain plaques of newly isolated bacteriophages, propagated
J. M. Los; Piotr Golec; G. Wegrzyn; A. Wegrzyn; M. Los
Computerized Assessment of Carotid Plaque Echogenicity before Stenting.
Summary: To assess the ability of transcutaneous ultrasound (US) to identify carotid atherosclerotic plaques at high risk for development of procedural strokes, the authors retrospectively analyzed the plaque echomorphology by means of gray-scale value (GSV). Both transcutaneous and intravascular US demonstrated a similar ability to characterize the atherosclerotic plaques. A case with embolic complication was proven to have had the lowest GSV in the studied cases. With computerized assessment of plaque echogenicity, pre-procedural transcutaneous US may be used to predict plaques that are associated with a high risk of distal embolization. PMID:20663397
Takahata, H; Hayashi, K; Kitagawa, N; Kaminogo, M; Koga, H; Shibata, S
Therapeutic strategies to deplete macrophages in atherosclerotic plaques
Macrophages can be found in all stages of atherosclerosis and are major contributors of atherosclerotic plaque development, progression and destabilization. Continuous recruitment of monocytes drives this chronic inflammatory disease, which can be intervened by several strategies: reducing the inflammatory stimulus by lowering circulating lipids and promoting cholesterol efflux from plaque, direct and indirect targeting of adhesion molecules and chemokines involved in monocyte adhesion and transmigration and inducing macrophage death in atherosclerotic plaques in combination with anti-inflammatory drugs. This review discusses the outlined strategies to deplete macrophages from atherosclerotic plaques to promote plaque stabilization.
De Meyer, Inge; Martinet, Wim; De Meyer, Guido R. Y.
Atherosclerotic plaque characterization by spatial and temporal speckle pattern analysis
NASA Astrophysics Data System (ADS)
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 (? = 40 ms) versus stable plaques (? = 400 ms) and normal aorta (? = 500 ms). These initial results indicate that different atherosclerotic plaque types may be distinguished by analysis of temporal and spatial speckle pattern fluctuations.
Tearney, Guillermo J.; Bouma, Brett E.
Imaging of coronary atherosclerosis and identification of the vulnerable plaque
Identification of the vulnerable plaque responsible for the occurrence of acute coronary syndromes and acute coronary death is a prerequisite for the stabilisation of this vulnerable plaque. Comprehensive coronary atherosclerosis imaging in clinical practice should involve visualisation of the entire coronary artery tree and characterisation of the plaque, including the three-dimensional morphology of the plaque, encroachment of the plaque on the vessel lumen, the major tissue components of the plaque, remodelling of the vessel and presence of inflammation. Obviously, no single diagnostic modality is available that provides such comprehensive imaging and unfortunately no diagnostic tool is available that unequivocally identifies the vulnerable plaque. The objective of this article is to discuss experience with currently available diagnostic modalities for coronary atherosclerosis imaging. In addition, a number of evolving techniques will be briefly discussed. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7
de Feyter, P.J.; Serruys, P. W.; Nieman, K.; Mollet, N.; Cademartiri, F.; van Geuns, R. J.; Slager, C.; van der Steen, A.F.W.; Krams, R.; Schaar, J.A.; Wielopolski, P.; Pattynama, P.M.T.; Arampatzis, A.; van der Lugt, A.; Regar, E.; Ligthart, J.; Smits, P.
Predominant cultivable flora isolated from human root surface caries plaque.
Plaque samples were obtained from tooth surfaces exhibiting typical lesions of root surface caries and were immediately cultured by a continuous anaerobic procedure. The bacterial composition of root caries flora was determined on individual samples. Representative isolates from each specimen were characterized by morphological and physiological criteria. In addition, fluorescent antibody reagents were used to confirm the identification of Streptococcus mutans and Actinomyces viscosus. The plaque samples could be divided into two groups on the basis of the presence or absence of S. mutans in the plaque. In group I plaques, S. mutans comprised 30 percent of the total cultivable flora. S. sanguis was either not found or was present in very low number. In group II plaques, S. mutans was not detected, and S. sanguis formed 48 percent of the total plaque flora. A. viscosus was the dominant organism in all plaque samples, accounting for 47 percent of the group I isolates and 41 percent of the group II isolates.
Syed, S A; Loesche, W J; Pape, H L; grenier, E
Plaque Production by Arboviruses in Singh's Aedes albopictus Cells
We report plaquing tests of 124 virus strains, mostly arboviruses of 21 serological groups, in Singh's line of Aedes albopictus cells. Thirty of these plaqued; all were arboviruses of six groups and were known or presumed to be mosquito borne. Failing to plaque were 86 strains of arboviruses, mostly tick borne, two strains of insect pathogens, and six animal viruses not classified as arboviruses. Among mosquito-borne agents, plaquing ability appeared related to serological classification. California group and most A-group viruses failed to plaque, but nearly all members of B and Bunyamwera groups readily plaqued. Within serological group B, 14 of 16 mosquito-borne agents plaqued, but none of 13 tick-borne or vector-unassociated viruses did so. Some implications of these results for recognition and classification of arboviruses are discussed. Images
Yunker, C. E.; Cory, J.
Simple Method for Plating Escherichia coli Bacteriophages Forming Very Small Plaques or No Plaques under Standard Conditions ?
The use of low concentrations (optimally 2.5 to 3.5 ?g/ml, depending on top agar thickness) of ampicillin in the bottom agar of the plate allows for formation of highly visible plaques of bacteriophages which otherwise form extremely small plaques or no plaques on Escherichia coli lawns. Using this method, we were able to obtain plaques of newly isolated bacteriophages, propagated after induction of prophages present in six E. coli O157:H? strains which did not form plaques when standard plating procedures were employed.
Los, Joanna M.; Golec, Piotr; Wegrzyn, Grzegorz; Wegrzyn, Alicja; Los, Marcin
Simple method for plating Escherichia coli bacteriophages forming very small plaques or no plaques under standard conditions.
The use of low concentrations (optimally 2.5 to 3.5 microg/ml, depending on top agar thickness) of ampicillin in the bottom agar of the plate allows for formation of highly visible plaques of bacteriophages which otherwise form extremely small plaques or no plaques on Escherichia coli lawns. Using this method, we were able to obtain plaques of newly isolated bacteriophages, propagated after induction of prophages present in six E. coli O157:H(-) strains which did not form plaques when standard plating procedures were employed. PMID:18586961
Lo?, Joanna M; Golec, Piotr; Wegrzyn, Grzegorz; Wegrzyn, Alicja; Lo?, Marcin
Thrombogenesis of the Rabbit Arterial Plaque
Rabbit arteries, de-endothelialized with an intravascular balloon catheter and allowed to heal for 4 weeks, showed intimal changes that were similar to the preatherosclerotic fibromusculoelastic plaques of man. Reinjury of the healed vessels by balloon catheter produced marked quantitative and qualitative alterations of hemostasis, as compared to that in previously uninjured vessels. The most apparent modification of thrombogenesis 10 minutes after injury to the plaque was a large increase in the size of the thrombotic deposits. Features of this exaggerated response were the major participation of fibrin in thrombus formation and greater platelet accumulation. Some platelets and fibrin strands appeared to penetrate into and beneath the neointima. By 3 hours, these deposits had diminished in size, although the hemostatic mass remained larger in the doubly injured vessels. ImagesFig 9Fig 3Fig 4Fig 5Fig 10Fig 6Fig 7Fig 1Fig 8Fig 2
Stemerman, Michael B.
[Pruritic urticarial papules and plaques in pregnancy].
PUPP is a specific eruptive dermatosis in pregnancy, clinically characterized by erythematous papules and plaques with intense itching in periumbilical localization. This disease typically tends to spread to the extremities without involving the head and neck regions. The differential diagnosis of PUPP can be established by immunological and microscopical investigations. Since PUPP is a benign disease with a good prognosis and spontaneous clearing, we recommend only mild symptomatic treatment. PMID:2264374
Füzesi, S; Antal, I; Petres, J
Intravascular Thermography for Assessing Vulnerable Plaques
Atherosclerosis and its cardiovascular complications remain the leading cause of death in developed countries. Current knowledge\\u000a of coronary artery disease progression has significantly evolved and the interest has been focused on the development of new\\u000a imaging techniques for the early detection of vulnerable lesions. Intracoronary thermography is a method that detects local\\u000a plaque inflammation. Clinical studies with intracoronary thermography have
Konstantinos Toutouzas; Maria Drakopoulou; Andreas Synetos; Christodoulos Stefanadis
Earliest Known Roman London Plaque Discovered
NSDL National Science Digital Library
Earlier today, archaeologists working on a massive dig on the southern banks of the River Thames uncovered the oldest known plaque inscribed with the city's Roman name, Londinium. While the exact date of the plaque is unknown, it is believed to date from between 50 and 150 AD, and would most likely have been placed on some type of building or in a shrine. Equally important, the plaque offers some initial concrete evidence that there was an emerging merchant class in London during this period. The actual location of the plaque's discovery is near the junction of what were three key roads in Roman Britain, and the finding represents only a small portion of what may be unearthed in this 40-week archaeology project.The first link is to a recent news story about the recent find in London. The second site leads to the Council for British Archaeology, which features numerous links to ongoing research projects within Britain and frequent updates about new findings from the field. The third site offers some perspective on the historical notion of Roman Britain, and particularly how scholars understand that epoch. The fourth site is a link to the complete work "Roman Roads in Britain," a historical study that seeks to describe and delineate the exact location of these very important Roman pathways. Information about the Museum of London, which is working jointly on this project, is provided by the fifth link. The last link, Britannia, is a nice omnibus listing of sites dealing with various aspects of Roman Britain history and archaeology, provided by the Dalton School in New York.
Grinnell, Max
Intravascular probe for detection of vulnerable plaque
NASA Astrophysics Data System (ADS)
Coronary angiography is unable to define the status of the atheroma, and only measures the luminal dimensions of the blood vessel, without providing information about plaque content. Up to 70% of heart attacks are caused by minimally obstructive vulnerable plaques, which are too small to be detected adequately by angiography. We have developed an intravascular imaging detector to identify vulnerable coronary artery plaques. The detector works by sensing beta or conversion electron radiotracer emissions from plaque-binding radiotracers. The device overcomes the technical constraints of size, sensitivity and conformance to the intravascular environment. The detector at the distal end of the catheter uses six 7mm long by 0.5mm diameter scintillation fibers coupled to 1.5m long plastic fibers. The fibers are offset from each other longitudinally by 6mm and arranged spirally around a guide wire in the catheter. At the proximal end of the catheter the optical fibers are coupled to an interface box with a snap on connector. The interface box contains a position sensitive photomultiplier tube (PSPMT) to decode the individual fibers. The whole detector assembly fits into an 8-French (2.7 mm in diameter) catheter. The PSPMT image is further decoded with software to give a linear image, the total instantaneous count rate and an audio output whose tone corresponds to the count rate. The device was tested with F-18 and Tl-204 sources. Spectrometric response, spatial resolution, sensitivity and beta to background ratio were measured. System resolution is 6 mm and the sensitivity is >500 cps / micrometers Ci when the source is 1 mm from the detector. The beta to background ratio was 11.2 for F-18 measured on a single fiber. The current device will lead to a system allowing imaging of labeled vulnerable plaque in coronary arteries. This type of signature is expected to enable targeted and cost effective therapies to prevent acute coronary artery diseases such as: unstable angina, acute myocardial infarction, and sudden cardiac death.
Patt, Bradley E.; Iwanczyk, Jan S.; MacDonald, Lawrence R.; Yamaguchi, Yuko; Tull, Carolyn R.; Janecek, Martin; Hoffman, Edward J.; Strauss, H. William; Tsugita, Ross; Ghazarossian, Vartan
Bacteriology of Human Experimental Gingivitis: Effect of Plaque Age
Twenty-five subjects with previously excellent hygiene and healthy gingiva developed heavy plaque accumulations and bleeding or nonbleeding gingivitis about certain papilla after 21 days of no oral hygiene. Gingival marginal plaque about a single papilla was collected at 0, 1, 2, and 3 weeks of no oral hygiene in each subject. The plaque was dispersed, serially diluted, and plated on MM10 sucrose agar in an oxygen-free atmosphere. From 50 to 100 colonies from a single high-dilution plate were characterized for each sample. Over 8,500 isolates were partially characterized and placed into one of 29 taxonomic species or groups. The flora was predominantly gram-positive at all time periods. Streptococcal species dominated in the 0- and 1-week-old plaques, i.e. 62 and 43% of the colonyforming units (CFU), but dropped to 26 to 32% of the CFU in the 2- and 3-week-old plaques. Actinomyces species dominated in the older plaques, i.e., 40 to 50% of the CFU. Actinomyces israelii was the most prominent species in the older plaques. Veillonella accounted for 15 to 20% of the CFU at all time periods. Although the other gram-negative species increased with time, collectively they averaged less than 5% of the CFU at week 3. The shift from a Streptococcus-dominated plaque to an Actinomyces-dominated plaque was the most striking microbial change observed as the plaque aged.
Syed, S. A.; Loesche, W. J.
Bacteriology of human experimental gingivitis: effect of plaque age.
Twenty-five subjects with previously excellent hygiene and healthy gingiva developed heavy plaque accumulations and bleeding or nonbleeding gingivitis about certain papilla after 21 days of no oral hygiene. Gingival marginal plaque about a single papilla was collected at 0, 1, 2, and 3 weeks of no oral hygiene in each subject. The plaque was dispersed, serially diluted, and plated on MM10 sucrose agar in an oxygen-free atmosphere. From 50 to 100 colonies from a single high-dilution plate were characterized for each sample. Over 8,500 isolates were partially characterized and placed into one of 29 taxonomic species or groups. The flora was predominantly gram-positive at all time periods. Streptococcal species dominated in the 0- and 1-week-old plaques, i.e. 62 and 43% of the colonyforming units (CFU), but dropped to 26 to 32% of the CFU in the 2- and 3-week-old plaques. Actinomyces species dominated in the older plaques, i.e., 40 to 50% of the CFU. Actinomyces israelii was the most prominent species in the older plaques. Veillonella accounted for 15 to 20% of the CFU at all time periods. Although the other gram-negative species increased with time, collectively they averaged less than 5% of the CFU at week 3. The shift from a Streptococcus-dominated plaque to an Actinomyces-dominated plaque was the most striking microbial change observed as the plaque aged. PMID:711336
Syed, S A; Loesche, W J
Multimodality imaging of carotid atherosclerotic plaque: Going beyond stenosis
Apart from the degree of stenosis, the morphology of carotid atherosclerotic plaques and presence of neovascularization are important factors that may help to evaluate the risk and 'vulnerability' of plaques and may also influence the choice of treatment. In this article, we aim to describe the techniques and imaging findings on CTA, high resolution MRI and contrast enhanced ultrasound in the evaluation of carotid atherosclerotic plaques. We also discuss a few representative cases from our institute with the related clinical implications.
Hingwala, Divyata; Kesavadas, Chandrasekharan; Sylaja, Padmavathy N; Thomas, Bejoy; Kapilamoorthy, Tirur Raman
Diabetes Adversely Affects Macrophages During Atherosclerotic Plaque Regression in Mice
OBJECTIVE Patients with diabetes have increased cardiovascular risk. Atherosclerosis in these patients is often associated with increased plaque macrophages and dyslipidemia. We hypothesized that diabetic atherosclerosis involves processes that impair favorable effects of lipid reduction on plaque macrophages. RESEARCH DESIGN AND METHODS Reversa mice are LDL receptor–deficient mice that develop atherosclerosis. Their elevated plasma LDL levels are lowered after conditional knockout of the gene encoding microsomal triglyceride transfer protein. We examined the morphologic and molecular changes in atherosclerotic plaques in control and streptozotocin-induced diabetic Reversa mice after LDL lowering. Bone marrow–derived macrophages were also used to study changes mediated by hyperglycemia. RESULTS Reversa mice were fed a western diet for 16 weeks to develop plaques (baseline). Four weeks after lipid normalization, control (nondiabetic) mice had reduced plasma cholesterol (?77%), plaque cholesterol (?53%), and plaque cells positive for macrophage marker CD68+ (?73%), but increased plaque collagen (+116%) compared with baseline mice. Diabetic mice had similarly reduced plasma cholesterol, but collagen content increased by only 34% compared with baseline; compared with control mice, there were lower reductions in plaque cholesterol (?30%) and CD68+ cells (?41%). Diabetic (vs. control) plaque CD68+ cells also exhibited more oxidant stress and inflammatory gene expression and less polarization toward the anti-inflammatory M2 macrophage state. Many of the findings in vivo were recapitulated by hyperglycemia in mouse bone marrow–derived macrophages. CONCLUSIONS Diabetes hindered plaque regression in atherosclerotic mice (based on CD68+ plaque content) and favorable changes in plaque macrophage characteristics after the reduction of elevated plasma LDL.
Parathath, Saj; Grauer, Lisa; Huang, Li-Shin; Sanson, Marie; Distel, Emilie; Goldberg, Ira J.; Fisher, Edward A.
Gene expression profiles in the Peyronie's disease plaque
Objectives. To provide molecular insight into the pathophysiology of Peyronie's disease (PD), a preliminary profile of differential gene expression between the PD plaque and control tunica albuginea was obtained with DNA microarrays.Methods. Seven PD plaques and five control tunica albugineas were studied. cDNA specimens were prepared from RNA isolated from one calcified PD plaque and one control tissue and hybridized
Thomas R Magee; Ansha Qian; Jacob Rajfer; Fred C Sander; Laurence A Levine; Nestor F Gonzalez-Cadavid
Dosimetric Benefit of a New Ophthalmic Radiation Plaque
Purpose: To determine whether the computed dosimetry of a new ophthalmic plaque, EP917, when compared with the standard Collaborative Ocular Melanoma Study (COMS) plaques, could reduce radiation exposure to vision critical structures of the eye. Methods and Materials: One hundred consecutive patients with uveal melanoma treated with COMS radiation plaques between 2007 and 2010 were included in this study. These treatment plans were generated with the use of Bebig Plaque Simulator treatment-planning software, both for COMS plaques and for EP917 plaques using I-125. Dose distributions were calculated for a prescription of 85 Gy to the tumor apex. Doses to the optic disc, opposite retina, lens, and macula were obtained, and differences between the 2 groups were analyzed by standard parametric methods. Results: When compared with the COMS plaques, the EP917 plaques used fewer radiation seeds by an average difference of 1.94 (P<.001; 95% confidence interval [CI], -2.8 to -1.06) and required less total strength of radiation sources by an average of 17.74 U (air kerma units) (P<.001; 95% CI, -20.16 to -15.32). The total radiation doses delivered to the optic disc, opposite retina, and macula were significantly less by 4.57 Gy, 0.50 Gy, and 11.18 Gy, respectively, with the EP917 plaques vs the COMS plaques. Conclusion: EP917 plaques deliver less overall radiation exposure to critical vision structures than COMS treatment plaques while still delivering the same total therapeutic dose to the tumor.
Marwaha, Gaurav, E-mail: email@example.com [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Wilkinson, Allan [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Singh, Arun D. [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States)
[Plaque surgery for Peyronie's disease: heterologous grafts].
Surgical treatment of Induratio Penis Plastica includes conservative procedures (phalloplasty), substitutive procedures (prosthesis) and combined procedures (phalloplasty plus prosthesis). Our policy for conservative treatment is based on radical removal of the plaque and replacement with biological patches. During a 15 year experience we employed lyophilized dura mater, autologous dermal graft, preputial skin, cadaveric dermal graft (AlloDerm), venous graft and porcine SIS (Small Intestine Submucosa) graft. Our experience confirms the superiority of venous grafts, but preliminary results with SIS grafts are encouraging. PMID:12868152
Paradiso, Matteo; Sedigh, Omid; Milan, Gian Luca
Plaque inhibition by hexetidine and zinc.
Rinsing experiments with mouthwashes containing zinc ions, hexetidine and a combination of hexetidine and zinc ions were performed with a group of 10 volunteers. The amount of plaque was assessed after rinsing with the test solutions for 4 days during which mechanical toothcleaning was discontinued. Significantly improved inhibition was observed by the combination of hexetidine and zinc ions compared with the two agents used separately. In vitro bacteriological tests showed that hexetidine and zinc ions had a synergistic inhibitory effect on the growth of Streptococcus mutans. PMID:3470899
Giertsen, E; Svatun, B; Saxton, A
Dynamics of plaque formation in Alzheimer's disease.
Plaques that form in the brains of Alzheimer patients are made of deposits of the amyloid-beta peptide. We analyze the time evolution of amyloid-beta deposition in immunostained brain slices from transgenic mice. We find that amyloid-beta deposits appear in clusters whose characteristic size increases from 14 microm in 8-month-old mice to 22 microm in 12-month-old mice. We show that the clustering has implications for the biological growth of amyloid-beta by presenting a growth model that accounts for the experimentally observed structure of individual deposits and predicts the formation of clusters of deposits and their time evolution.
Urbanc, B; Cruz, L; Buldyrev, S V; Havlin, S; Irizarry, M C; Stanley, H E; Hyman, B T
Nature or The Natural Evolution of Plaque: What Matters?
ABSTRACT Progression to major acute cardiovascular events often is triggered by an atherosclerotic plaque complicated by rupture or erosion, namely the vulnerable plaque. Early and secure identification of these plaques would allow the development of individualized therapeutic and pharmacological strategies, applied in a timely manner. Imaging methods have a huge potential in detecting and monitoring the evolution of vulnerable plaque. Even though there are multiple invasive and noninvasive techniques, clinical application is for now a matter of choosing the relevant imaging feature for the prognosis, the methodology of study and the target population.
AURSULESEI, Viviana
Effectiveness of Veadent as a plaque-inhibiting mouthwash.
The aim of this study was to compare the effect of the commercially available Veadent mouthwash and chlorhexidine on plaque formation. Plaque accumulating during two 5-day periods was recorded in a group of 10 students. During the experimental periods, the test subjects abstained from mechanical cleaning of the teeth, and chewed sucrose-containing chewing gum every 4th h in order to enhance plaque formation. They also rinsed with either chlorhexidine or Veadent twice a day according to the manufacturer's recommendations. Chlorhexidine mouthrinses resulted in significantly lower plaque scores than did Veadent in the present short-term model study. PMID:3912956
Abbas, D K; Thrane, P; Othman, S J
Plaque rupture with severe pre-existing stenosis precipitating coronary thrombosis. Characteristics of coronary atherosclerotic plaques underlying fatal occlusive thrombi
Ruptured atheromatous plaques were identified by step-sectioning technique as responsible for 40 of 51 recent coronary artery thrombi and 63 larger intimal haemorrhages. The degree of pre-existing luminal narrowing at the site of rupture was decisive for whether plaque rupture caused occlusive thrombosis or just intimal haemorrhage. If the pre-existing stenosis was greater than 90% (histologically determined) then plaque rupture
E Falk
Granulomatous rosacea: unusual presentation as solitary plaque.
A 45-year-old male presented with a 6 month history of an enlarging smooth, erythematous plaque over the central part of his face. Mild erythema of both eyes was present. Sarcoidosis, Hansen disease, lupus vulgaris, cutaneous leishmaniasis, pseudolymphoma, foreign body granuloma, granuloma faciale, discoid lupus erythematosus, and granulomatous rosacea were considered in the differential diagnosis. CBC, urinalysis, renal function tests, liver function tests, serum electrolytes, and blood sugar were all normal. Chest X-ray and ECG revealed no abnormality. Serology for syphilis and HIV, and mantoux test were negative. Slit-skin smear, tissue smear and culture for AFB and fungi were negative. Skin biopsy revealed multiple non-caseating epitheloid granulomas around the pilosebaceous unit suggestive of granulomatous rosacea. Granulomatous rosacea, a rare entity comprising only about 10 percent of cases of rosacea can mimic many granulomatous conditions both clinically and histologically making the diagnosis an enigma. It usually presents as yellowish brown-red discrete papules on the face; non-caseating epithelioid granulomas are seen on histology examination. We herein report the case because it presented in atypical fashion, as a solitary indurated plaque on the nose, likely representing Morbihan's disease or solid persistent facial edema of rosacea (rosacea lymphedema). PMID:21382292
Batra, Mayanka; Bansal, Cherry; Tulsyan, Suman
Prophylaxis for infective endocarditis: antibiotic sensitivity of dental plaque
The antibiotic sensitivity pattern of bacteria isolated from bacteraemia after dental extraction was compared with that of bacteria isolated from dental plaque samples from the same patient. The results supported the current practice of using penicillin and erythromycin empirically for prophylaxis. The prediction of the most appropriate antibiotic for prophylaxis using dental plaque samples was most accurate when the minimum
T W MacFarlane; D A McGowan; K Hunter; D MacKenzie
A comparative study on plaque vulnerability using constitutive equations.
Atherosclerosis is the most serious and common form of cardiovascular disease in which plaque builds up inside the arteries. Peak plaque stress is considered as the main reason for plaque rupture, which results in heart attack and stroke. In the current research, the finite element method is used to anticipate plaque vulnerability, using human samples. A total of 23 healthy and atherosclerotic human coronary arteries (14 healthy and 9 atherosclerotic) were removed within 5 h postmortem. The samples were mounted on a uniaxial tensile test machine and the obtained mechanical properties were used in finite element models. The peak plaque stresses for the Ogden hyperelastic model were compared to the Mooney-Rivlin and Neo-Hookean outcomes. The results indicated that hypocellular plaque in all three models has the highest stress values compared to the cellular and calcified ones and, as a result, is quite prone to rupture. The calcified plaque type, in contrast, has the lowest stress values and remains stable. The results can be used in plaque vulnerability prediction and have clinical implications for interventions and surgeries such as balloon-angioplasty, cardiopulmonary bypass and stenting. PMID:23999817
Karimi, A; Navidbakhsh, M; Faghihi, S
Apollo Soyuz Test Project Commemorative plaque in orbit
NASA Technical Reports Server (NTRS)
The Apollo-Soyuz Test Project (ASTP) Commemorative Plaque is assembled in the Soviet Soyuz Orbital Module during the joint U.S.-U.S.S.R. Apollo-Soyuz Test Project docking in Earth orbit mission. The plaque is written both in English and Russian.
New low-viscosity overlay medium for viral plaque assays
Background Plaque assays in cell culture monolayers under solid or semisolid overlay media are commonly used for quantification of viruses and antiviral substances. To overcome the pitfalls of known overlays, we tested suspensions of microcrystalline cellulose Avicel RC/CL™ as overlay media in the plaque and plaque-inhibition assay of influenza viruses. Results Significantly larger plaques were formed under Avicel-containing media, as compared to agar and methylcellulose (MC) overlay media. The plaque size increased with decreasing Avicel concentration, but even very diluted Avicel overlays (0.3%) ensured formation of localized plaques. Due to their low viscosity, Avicel overlays were easier to use than methylcellulose overlays, especially in the 96-well culture plates. Furthermore, Avicel overlay could be applied without prior removal of the virus inoculum thus facilitating the assay and reducing chances of cross-contamination. Using neuraminidase inhibitor oseltamivir carboxylate, we demonstrated applicability of the Avicel-based plaque reduction assay for testing of antiviral substances. Conclusion Plaque assay under Avicel-containing overlay media is easier, faster and more sensitive than assays under agar- and methylcellulose overlays. The assay can be readily performed in a 96-well plate format and seems particularly suitable for high-throughput virus titrations, serological studies and experiments on viral drug sensitivity. It may also facilitate work with highly pathogenic agents performed under hampered conditions of bio-safety labs.
Matrosovich, Mikhail; Matrosovich, Tatyana; Garten, Wolfgang; Klenk, Hans-Dieter
Characterization of bacteriophage communities and CRISPR profiles from dental plaque
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.
Oxysterols and symptomatic versus asymptomatic human atherosclerotic plaque.
Atherosclerosis is the most common cause of mortality in the Western world, contributing to about 50% of all deaths. Atherosclerosis is characterized by deposition of lipids onto the coronary or carotid arterial wall and formation of an atherosclerotic plaque. Atherosclerotic plaques are categorized into two groups: symptomatic and asymptomatic. The symptomatic plaques tend to be unstable and prone to rupture, and are associated with an increase in ischemic events. Oxysterols, products of cholesterol oxidation, are cytotoxic materials. Their level and type may be associated with plaque formation, development and stability. Oxysterols stimulate the formation of foam cells, advance atherosclerotic plaque progression, and contribute to plaque vulnerability and instability due to their cytotoxicity and their ability to induce cell apoptosis. Studies indicate that plasma 7?-OH CH level can be used as a biomarker for detecting carotid and coronary artery disease. Further clinical studies are needed to evaluate the potential of oxysterols for use as biomarkers for plaque vulnerability and instability. The identification of biomarkers in the blood that can distinguish between symptomatic and asymptomatic plaques remains an unresolved issue. PMID:24393847
Khatib, Soliman; Vaya, Jacob
Investigation of Plaque Effects on Cardiovascular Stent System
A 3D composite stent model, which consists of the stent, plaque, and artery wall, is generated to characterize stent transient expansion and deflection behavior using Finite Element Method (FEM) approach. Two types (flat and central-thicker) of plaque models have been employed to evaluate the geometrical effects of atherosclerotic artery on the cardiovascular stent deployment system. Simulation results demonstrated that the
Heng-Chuan Kan
Clinical classification of plaque morphology in coronary disease.
In published post-mortem pathological studies, more than two-thirds of acute coronary events are associated with the rupture of lipid-rich, voluminous, and outwardly remodelled plaques covered by attenuated and inflamed fibrous caps in the proximal part of coronary arteries. Superficial erosion of the plaques is responsible for most of the remaining events; the eroded plaques usually do not demonstrate much lipid burden, do not have thin fibrous caps, are not positively remodelled, and are not critically occlusive. Both noninvasive and invasive imaging studies have been performed to clinically define the plaque characteristics in acute coronary syndromes in an attempt to identify the high-risk plaque substrate susceptible to development of an acute coronary event. Optical coherence tomography (OCT)-an intravascular imaging modality with high resolution-can be used to define various stages of plaque morphology, which might allow its use for the identification of high-risk plaques vulnerable to rupture, and their amenability to pre-emptive interventional treatment. OCT might also be employed to characterize plaque pathology at the time of intervention, to provide a priori knowledge of the mechanism of the acute coronary syndrome and, therefore, to enable improved management of the condition. PMID:24776706
Otsuka, Fumiyuki; Joner, Michael; Prati, Francesco; Virmani, Renu; Narula, Jagat
Plaque assay for African swine fever virus on swine macrophages.
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. PMID:12111419
Bustos, M J; Nogal, M L; Revilla, Y; Carrascosa, A L
Imaging of the unstable plaque: how far have we got?
Rupture of unstable plaques may lead to myocardial infarction or stroke and is the leading cause of morbidity and mortality in western countries. Thus, there is a clear need for identifying these vulnerable plaques before the rupture occurs. Atherosclerotic plaques are a challenging imaging target as they are small and move rapidly, especially in the coronary tree. Many of the currently available imaging tools for clinical use still provide minimal information about the biological characteristics of plaques, because they are limited with respect to spatial and temporal resolution. Moreover, many of these imaging tools are invasive. The new generation of imaging modalities such as magnetic resonance imaging, nuclear imaging such as positron emission tomography and single photon emission computed tomography, computed tomography, fluorescence imaging, intravascular ultrasound, and optical coherence tomography offer opportunities to overcome some of these limitations. This review discusses the potential of these techniques for imaging the unstable plaque. PMID:19833636
Matter, Christian M; Stuber, Matthias; Nahrendorf, Matthias
Imaging of the unstable plaque: how far have we got?
Rupture of unstable plaques may lead to myocardial infarction or stroke and is the leading cause of morbidity and mortality in western countries. Thus, there is a clear need for identifying these vulnerable plaques before the rupture occurs. Atherosclerotic plaques are a challenging imaging target as they are small and move rapidly, especially in the coronary tree. Many of the currently available imaging tools for clinical use still provide minimal information about the biological characteristics of plaques, because they are limited with respect to spatial and temporal resolution. Moreover, many of these imaging tools are invasive. The new generation of imaging modalities such as magnetic resonance imaging, nuclear imaging such as positron emission tomography and single photon emission computed tomography, computed tomography, fluorescence imaging, intravascular ultrasound, and optical coherence tomography offer opportunities to overcome some of these limitations. This review discusses the potential of these techniques for imaging the unstable plaque.
Matter, Christian M.; Stuber, Matthias; Nahrendorf, Matthias
Automated coronary CT angiography plaque-lumen segmentation
NASA Astrophysics Data System (ADS)
We are investigating the feasibility of a computer-aided detection (CAD) system to assist radiologists in diagnosing coronary artery disease in ECG gated cardiac multi-detector CT scans having calcified plaque. Coronary artery stenosis analysis is challenging if calcified plaque or the iodinated blood pool hides viable lumen. The research described herein provides an improved presentation to the radiologist by removing obscuring calcified plaque and blood pool. The algorithm derives a Gaussian estimate of the point spread function (PSF) of the scanner responsible for plaque blooming by fitting measured CTA image profiles. An initial estimate of the extent of calcified plaque is obtained from the image evidence using a simple threshold. The Gaussian PSF estimate is then convolved with the initial plaque estimate to obtain an estimate of the extent of the blooming artifact and this plaque blooming image is subtracted from the CT image to obtain an image largely free of obscuring plaque. In a separate step, the obscuring blood pool is suppressed using morphological operations and adaptive region growing. After processing by our algorithm, we are able to project the segmented plaque-free lumen to form synthetic angiograms free from obstruction. We can also analyze the coronary arteries with vessel tracking and centerline extraction to produce cross sectional images for measuring lumen stenosis. As an additional aid to radiologists, we also produce plots of calcified plaque and lumen cross-sectional area along selected blood vessels. The method was validated using digital phantoms and actual patient data, including in one case, a validation against the results of a catheter angiogram.
Cline, Harvey E.; Krishnan, Karthik; Napel, Sandy; Rubin, Geoffrey D.; Turner, Wesley D.; Avila, Ricardo S.
Infections and atheromatous plaque: current therapeutic implications.
Infections are the most common inflammatory triggers and acute and chronic infections have been associated with the development and progression of atherosclerotic disease raising interest in the infectious hypothesis of atherosclerosis. Pathogens have been identified in atherosclerotic plaques and large epidemiological studies have documented conflicting associations between serological evidence of infection and cardiovascular events. Influenza A was mostly studied as a trigger for cardiovascular events during winter months, whilst cytomegalovirus, Chlamydia pneumoniae, helicobacter pylori and porphyromonas ginigivalis were the most studied chronic pathogens which had been associated with the development and progression of cardiovascular disease. Infectious agents can contribute to atherosclerosis by having a direct effect on the vascular wall or via indirect effects including inflammatory responses and molecular mimicry. Efforts to prevent infection with vaccination or treat specific infectious agents with antibiotics have provided mostly negative results, thereby challenging the validity of the infectious hypothesis of atherosclerosis. PMID:23016720
Charakida, Marietta; Tousoulis, Dimitris
Association of Carotid Plaque Echogenicity with Recurrence of Ischemic Stroke
Background: Atherosclerosis is related to various cardiovascular and cerebrovascular events like cerebral infarction. Recurrence of ischemic stroke is specifically related to atherosclerotic load as determined by the presence of carotid atheromatous plaques and its echogenicity. Aim: This study was to evaluate the association of recurrence of stroke with echogenic characteristics of carotid plaque in ischemic stroke patients. Materials and Methods: Carotid sonography using high-resolution 7.5 MHz along with gray-scale technique was done in each ischemic stroke patient to find the occurrence of plaque and its echogenicity according to Mannheim Carotid Intima-Media Thickness Consensus (2004-2006). Followup of patient done to know the recurrence of stroke during 6-month duration and its association with plaque echogenicity. Results: A significant association found between the presence of plaque and known cerebrovascular risk factors. Also significant association found between recurrence of stroke and echolucent character of carotid plaque in bivariate analysis (P = 0.0028). Conclusions: Recurrence of stroke is related to advanced stage of atherosclerosis that is specified by carotid plaque and its characteristics. It will help us to identify groups of patients at different risk for stroke and planning better strategies to prevent such events.
Singh, Amit Shankar; Atam, Virendra; Jain, Nirdesh; Yathish, Besthanahalli Errapa; Patil, Malagouda R; Das, Liza
The association of pericardial fat with calcified coronary plaque
Background Pericardial fat has a higher secretion of inflammatory cytokines than subcutaneous fat. Cytokines released from pericardial fat around coronary arteries may act locally on the adjacent cells. Objective We examined the relationship between pericardial fat and calcified coronary plaque. Design Participants in the community-based Multi-Ethnic Study of Atherosclerosis underwent a computed tomography scan for the assessment of calcified coronary plaque in 2001/02. We measured the volume of pericardial fat using these scans in 159 whites and blacks without symptomatic coronary heart disease from Forsyth County, NC, aged 55–74 years. Results Calcified coronary plaque was observed in 91 participants (57%). After adjusting for height, a one standard deviation increment in pericardial fat was associated with an increased odds of calcified coronary plaque (odds ratio (95% confidence interval): 1.92 (1.27, 2.90)). With further adjustment of other cardiovascular factors, pericardial fat was still significantly associated with calcified coronary plaque. This relationship did not differ by gender and ethnicity. On the other hand, body mass index and height-adjusted waist circumference were not associated with calcified coronary plaque. Conclusions Pericardial fat is independently associated with calcified coronary plaque.
Ding, Jingzhong; Kritchevsky, Stephen B.; Harris, Tamara B.; Burke, Gregory L.; Detrano, Robert C.; Szklo, Moyses; Carr, J. Jeffrey
Collagenolytic Activity of Dental Plaque Associated with Periodontal Pathology
Certain dental plaques, removed from sites of gingival and periodontal pathology in mentally retarded, institutionalized individuals, when incubated in phosphate buffer with Achilles tendon collagen, gave rise to an increase in ninhydrin-positive material. These plaques, while showing great variability, released significantly more ninhydrin-positive material per milligram of plaque (wet weight) than did either the endogenous or heat-treated controls. Certain plaques could also break down soluble, tritiated, labeled collagen isolated from the calvaria of chicken embryos. Bacteroides melaninogenicus and Clostridia histolyticum were found in plaques by either fluorescent antibody or cultural methods. C. histolyticum, when detected, accounted for about 0.01 to 0.1% of the bacteria in plaque. A conspicuous isolate from some plaques was a Bacillus species which rapidly liquefied gelatin. Cell-free supernatants of this organism were able to degrade about 50 to 70% of the soluble collagen when incubated at 36 C. C. histolyticum ATCC 8034 caused an 80% degradation of the collagen under the same conditions of incubation. The Bacillus strains were facultative, could ferment glucose, reduced nitrate to nitrite, and were catalase, indole, and urease negative. The limited taxonomic information for the isolates is compatible with the description given for Bacillus cereus.
Loesche, W. J.; Paunio, K. U.; Woolfolk, M. P.; Hockett, R. N.
Siglec receptors and hiding plaques in Alzheimer's disease.
Alzheimer's disease (AD) is a progressive neurodegenerative disease. One hallmark of this disease is the continuous increase in the numbers and size of aggregating amyloid plaques. The accumulation of extracellular plaques is an immunologically interesting phenomenon since microglial cells, brain-specific macrophages, should be able to cleanse the aggregating material from the human brain. Immunotherapy targeting beta-amyloid peptides in plaques with antibodies represents a promising therapy in AD. Recent progress in pattern recognition receptors of monocytes and macrophages has revealed that the sialic acid-binding, immunoglobulin-like lectin (Siglec) family of receptors is an important recognition receptor for sialylated glycoproteins and glycolipids. Interestingly, recent studies have revealed that microglial cells contain only one type of Siglec receptors, Siglec-11, which mediates immunosuppressive signals and thus inhibits the function of other microglial pattern recognition receptors, such as TLRs, NLRs, and RAGE receptors. We will review here the recent literature which clearly indicates that aggregating amyloid plaques are masked in AD by sialylated glycoproteins and gangliosides. Sialylation and glycosylation of plaques, mimicking the cell surface glycocalyx, can activate the immunosuppressive Siglec-11 receptors, as well as hiding the neuritic plaques, allowing them to evade the immune surveillance of microglial cells. This kind of immune evasion can prevent the microglial cleansing process of aggregating amyloid plaques in AD. PMID:19390836
Salminen, Antero; Kaarniranta, Kai
Intravascular photoacoustic imaging: a new tool for vulnerable plaque identification.
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. PMID:24631379
Jansen, Krista; van Soest, Gijs; van der Steen, Antonius F W
Microglial response to amyloid plaques in APPsw transgenic mice.
Microglial activation is central to the inflammatory response in Alzheimer's Disease (AD). A recently described mouse line, Tg(HuAPP695.K670N/M671L)2576, expressing human amyloid precursor protein with a familial AD gene mutation, age-related amyloid deposits, and memory deficits, was found to develop a significant microglial response using Griffonia simplicifolia lectin or phosphotyrosine probe to identify microglia Both Griffonia simplicifolia lectin and phosphotyrosine staining showed increased numbers of intensely labeled, often enlarged microglia clustered in and around plaques, consistent with microglial activation related to beta-amyloid formation. Using quantitative image analysis of coronal phosphotyrosine-immunostained sections, transgene-positive 10- to 16-month-old, hemizygous, hybrid Tg2576 (APPsw) animals showed significantly increased microglial density and size in plaque-forming areas of hippocampus and frontal, entorhinal, and occipital cortex. Quantitative analysis of microglia as a function of distance from the center of plaques (double labeled for A beta peptide and microglia) revealed highly significant, two- to fivefold elevations in microglial number and area within plaques compared with neighboring regions. Tg2576 beta-amyloid-plaque-forming mice should be a useful system for assessing the consequences of the microglial-mediated inflammatory response to beta-amyloid and developing anti-inflammatory therapeutic strategies for Alzheimer's disease. These results provide the first quantitative link between beta-amyloid plaque formation and microglial activation in an animal model with neuritic plaques and memory deficits. Images Figure 1 Figure 2
Frautschy, S. A.; Yang, F.; Irrizarry, M.; Hyman, B.; Saido, T. C.; Hsiao, K.; Cole, G. M.
Non-pulsed electrochemical impregnation of flexible metallic battery plaques
A method of loading active battery material into porous, flexible, metallic battery plaques, comprises the following steps: precipitating nickel hydroxide active material within the plaque, by making the plaque cathodic, at a high current density, in an electro-precipitation cell also containing a consumable nickel anode and a solution comprising nickel nitrate, having a pH of between 2.0 and 2.8; electrochemically oxidizing the precipitate in caustic formation solution; and repeating the electro-precipitation step at a low current density.
Maskalick, Nicholas J. (Pittsburgh, PA)
[Methylation profiling of human atherosclerotic plaques].
Somatic mutation theory of atherogenesis proved by alterations at the DNA level such as "loss of heterozygosity" and microsatellite instability in atherosclerotic plaque is complemented by the date of epigenetic variability of genetic loci involved in the pathological process. However, only recently large-scale analysis of epigenetic modifications in the human genome became possible. For the first time quantitative microarray-based methylation profiling of 1505 CpG-sites across 807 genes was performed in atherosclerotic aorta and carotid artery wall lesions using the GoldenGate Methylation Cancer Panel I ("Illumina", USA). One hundred and three (7%) CpG-sites in 90 (11%) genes were differentially methylated between tissue samples. The most pronounced differences in DNA methylation levels were registered for a site which is located in CpG-island of imprinted gene H19. By comparing 90 genes that were differentially methylated between tissue samples in our study, 10 genes (ICAM1, GSTM1, IGFBP1, POMC, APOA1, IL1RN, INS, LTA, MMP3, THBS2) were overlapped with data in Human Genome Epidemiology Network (HuGENet), in which they were identified as candidates for cardiovascular disease continuum. PMID:21954592
Nazarenko, M S; Puzyrev, V P; Lebedev, I N; Frolov, A V; Barbarash, O L; Barbarash, L S
Spectroscopic intravascular photoacoustic imaging to differentiate atherosclerotic plaques.
The potential of intravascular photoacoustic (IVPA) imaging to detect atherosclerosis was previously demonstrated using a 532 nm nanosecond pulsed laser and an intravascular ultrasound (IVUS) imaging catheter. However, to differentiate vulnerable plaques, the composition of plaques needs to be imaged. Therefore, we introduce a multi-wavelength photoacoustic imaging method to distinguish various types of plaques. Multi-spectral IVPA imaging of ex vivo samples of normal and atherosclerotic rabbit aorta was performed at several wavelengths within 680-900 nm range. The spectral variation of photoacoustic response was extracted and a spectroscopic analysis was performed. The results of our preliminary study suggest that the spectroscopic intravascular photoacoustic imaging technique can be used to differentiate fibrous and lipid components of the atherosclerotic plaques. PMID:18542427
Sethuraman, Shriram; Amirian, James H; Litovsky, Silvio H; Smalling, Richard W; Emelianov, Stanislav Y
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
6. VIEW OF COMMEMORATIVE PLAQUE, EAST APPROACH GUARDRAIL, WHICH STATES 'SALINE RIVER; ARK. GENERAL CONST. CO.; CONTRACTOR; ARKANSAS; STATE HIGHWAY DEPARTMENT; 1928, BRIDGE NO. __.' - Saline River Bridge, County Highway 365 across Saline River, Benton, Saline County, AR
Advances in mechanisms, imaging and management of the unstable plaque.
Post-mortem observations demonstrated that plaque fissure was the final event leading to coronary thrombosis and occlusion in about two-thirds of cases of sudden coronary death. Plaques prone to fissure have, therefore, been defined "vulnerable plaques" and are identified by specific anatomic features including thin inflamed fibrous cap, large lipidic core and positive remodeling. Accordingly, elegant imaging modalities have been developed in order to identify this "holy grail". However, the results of prognostic studies based on the identification of vulnerable plaques have not been encouraging because of the low positive predictive value for major cardiovascular events. This observation is not surprising as the pathogenesis of acute coronary syndromes is complex and multifactorial. In this review we propose a pathogenetic classification of acute coronary syndromes in the attempt to identify homogeneous groups of patients with a common mechanism of coronary instability which can be identified by using specific biomarkers and imaging techniques, and become a specific therapeutic target. PMID:24530781
Niccoli, Giampaolo; Liuzzo, Giovanna; Montone, Rocco A; Crea, Filippo
Coronary plaque imaging by coronary computed tomography angiography
Coronary computed tomography angiography (CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coronary artery disease (CAD). With the development of technical aspects of coronary CTA, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes by coronary CTA. In this review we discuss the coronary plaque morphology estimated by CTA beyond coronary angiography including the comparison to the currently available other imaging modalities used to examine morphological characteristics of the atherosclerotic plaque. Furthermore, this review underlies the value of a combined assessment of coronary anatomy and myocardial perfusion in patients with CAD, and adds to an increasing body of evidence suggesting an added diagnostic value when combining both modalities. We hope that an integrated, multi-modality imaging approach will become the gold standard for noninvasive evaluation of coronary plaque morphology and outcome data in clinical practice.
Sato, Akira
Penetrating the plaque biofilm: impact of essential oil mouthwash.
The interaction between saliva-coated tooth surfaces and pathogenic bacteria is partly governed by electrostatic and hydrophobic interactions, providing a solid rationale for using chemical agents as part of a plaque-control routine. Chlorhexidine works in several ways. For example, it binds to salivary mucins on the bacterial cell membrane, and penetrates the plaque biofilm. Essential oil (EO) mouthwashes kill micro-organisms by disrupting their cell walls and inhibiting their enzymic activity. They prevent bacterial aggregation, slow multiplication and extract endotoxins. Recent studies have shown that bacterial phenotypes are altered when organisms change from a planktonic to a sessile state. This suggests that an effective mouthwash must also penetrate the plaque biofilm. Two studies have demonstrated the ability of an EO mouthwash to penetrate the plaque biofilm. PMID:12787196
Ouhayoun, J-P
CT evaluation of vulnerable plaque: noninvasive fortune-telling?
Recently, cardiac CTA has been proposed as a promising noninvasive tool for identification of rupture-prone plaques prior to a subsequent coronary event. This task is particularly challenging but the reward is high: identification of high-risk lesions could preclude plaque thrombosis and possibly prevent acute coronary syndromes. We present a case of a borderline mixed plaque with positive remodeling in the proximal left anterior descending artery (LAD). After 6 months and despite aggressive medical therapy, the patient developed acute ST-elevation myocardial infarction caused by a thrombotic lesion in the proximal LAD. We review the literature on CT characteristics of vulnerable plaque and discuss the possible preventive interventions. PMID:21505956
Opolski, Maksymilian P; Kepka, Cezary; Witkowski, Adam
Correlation between aortic/carotid atherosclerotic plaques and cerebral infarction
The aim of this study was to investigate the correlation between aortic/carotid atherosclerotic plaques and cerebral infarction. We examined 116 cases of cerebral infarction using transcranial Doppler ultrasound in order to exclude cerebrovascular stenosis. Transesophageal echocardiography and color Doppler ultrasound were used to detect aortic atherosclerotic plaques (AAPs) and carotid atherosclerotic plaques (CAPs). AAPs were detected in a total of 70 of the 116 cases (60.3%), including 56 with moderate/severe atherosclerotic changes (48.3%). The difference in the incidence of various types of infarction between APP severity levels was significant (P<0.01). Of the 116 cases, 64 had CAPs (55.2%), including 46 with unstable plaque (39.7%). The difference in the incidence of various types of infarction between CAP stability levels was significant (P<0.01). The results indicate that moderate/severe AAP and unstable CAP are significant causes of embolic infarction without stenosis in the internal carotid arteries.
Some aspects of plaque formation by human influenza viruses
Summary Infective influenza virus seems to be essential for plaque production in chick embryo fibroblasts (CEF). With some virus strains, the amounts of virus produced by infected monolayers under an agarose overlay are very small.
C. P. de Sousa; G. Belyavin
Elevation view of dedication plaque on east wall of south ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
Elevation view of dedication plaque on east wall of south lobby - National Home for Disabled Volunteer Soldiers, Pacific Branch, Main Mental Health Building, 11301 Wilshire Boulevard, West Los Angeles, Los Angeles County, CA
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
32. STUDIO VIEW OF PLAQUE PLACED ON MILL HOUSE AT TIME OF COMPLETION, COMMEMORATING EDWARD J. LUKE (SEE TEXT) - Sperry Corn Elevator Complex, Weber Avenue (North side), West of Edison Street, Stockton, San Joaquin County, CA
8. DESCRIPTION PLAQUE Copy photograph of photogrammetric plate LCHAERPS052000402 ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
8. DESCRIPTION PLAQUE Copy photograph of photogrammetric plate LC-HAER-PS05-2000-402 - Falls Bridge, Spanning Schuylkill River, connecting East & West River Drives, Philadelphia, Philadelphia County, PA
Enzymes of Plaque Polysaccharides and Dental Caries Incidence.
National Technical Information Service (NTIS)
Plaque samples from 50 subjects have been obtained in cooperation with the Great Lakes Naval Training Center. These samples were analyzed to determine the activity of the following enzymes--levansucrase, dextrane-sucrase, levanase, and dextranase. It was ...
R. S. Manly
Finite element modeling and intravascular ultrasound elastography of vulnerable plaques: parameter variation
Background and goal: More than 60% of all myocardial infarction is caused by rupture of a vulnerable plaque. A vulnerable plaque can be described as a large, soft lipid pool covered by a thin fibrous cap. Plaque material composition, geometry, and inflammation caused by infiltration of macrophages are considered as major determinants for plaque rupture. For diagnostic purposes, these determinants
Radj A. Baldewsing; Chris L. de Korte; Johannes A. Schaar; Frits Mastik; Antonius F. W. van der Steen
Drug Therapies to Prevent Coronary Plaque Rupture and Erosion: Present and Future
Patients at high risk for coronary heart disease usually have a number of atherosclerotic plaques in their coronary arteries. Some plaques grow inward and, once they have caused a critical degree of luminal stenosis, lead to chronic anginal symptoms. Other plaques grow outward and remain silent unless they disrupt and trigger an acute coronary event. Either type of plaque may
P. T. Kovanen; M. Mäyränpää; K. A. Lindstedt
Ultrashort echo time cardiovascular magnetic resonance of atherosclerotic carotid plaque
BACKGROUND: Multi-contrast weighted cardiovascular magnetic resonance (CMR) allows detailed plaque characterisation and assessment of plaque vulnerability. The aim of this preliminary study was to show the potential of Ultra-short Echo Time (UTE) subtraction MR in detecting calcification. METHODS: 14 ex-vivo human carotid arteries were scanned using CMR and CT, prior to histological slide preparation. Two images were acquired using a
Cheuk F Chan; Niall G Keenan; Sonia Nielles-Vallespin; Peter Gatehouse; Mary N Sheppard; Joseph J Boyle; Dudley J Pennell; David N Firmin
Molecular MRI of Atherosclerotic Plaque With Targeted Contrast Agents
Molecular MRI of atherosclerosis involves the use of novel contrast agents to image cellular and molecular processes within atherosclerotic plaque. Agents to image plaque lipid content, inflammation, angiogenesis, and thrombosis have been developed and studied extensively in animal models of atherosclerosis and vascular injury. Selected agents have also been studied in humans, with highly promising initial results. In this brief review, recent advances as well as opportunities and challenges in the field are discussed.
Sosnovik, David E.; Caravan, Peter
Identification of Autoantigens in Psoriatic Plaques Using Expression Cloning
To search for autoantigens in psoriatic plaques, we screened cDNA libraries of plaque epidermis with psoriatic serum samples. This approach has been highly successful in identifying tumor antigens, but has not been widely applied to autoimmune disease. We identified 11 autoantigens including three with prominent reactivity and plausible disease relevance. These are keratin 13 (K13), heterogeneous nuclear ribonucleoprotein-A1 (hnRNP-A1), and
David A. Jones; Nikhil Yawalkar; Ki-Young Suh; Sara Sadat; Benjamin Rich; Thomas S. Kupper
Lipid-Rich Plaque Masquerading as a Coronary Thrombus
A 43-year-old woman presented with exertional chest pressure. Right coronary angiography showed a clear filling defect. Intravascular ultrasound revealed a plaque with 80% stenosis and a large lipid pool. Therefore, a stent was placed, and the patient became angina-free. Lipid-rich plaques are a cause of angiographic filling defects. Intravascular ultrasound is an integral part of coronary artery evaluation.
Rezkalla, Shereif H.; Holmes, David R.
Tryptase Promotes Atherosclerotic Plaque Haemorrhage in ApoE-/- Mice
Tryptase, the most abundant mast cell (MC) granule protein, plays an important role in atherosclerosis plaque development. To test the hypothesis that tryptase participates directly in atherosclerosis plaque haemorrhage, the gene sequence and siRNA for tryptase were cloned into a lentivirus carrier and atherosclerosis plaque haemorrhage models in ApoE-/- mice were constructed. After a cuffing-cervical artery operation, the mice were randomly divided into 6 groups. Hematoxylin and eosin(HE) staining showed that the cervical artery plaque area was much larger in the tryptase overexpression group compared to the other groups, and there was greater artery stenosis. The artery stenosis from the cuff-side in all groups was more than 90%, except the siRNA group. Tryptase promotes plaque haemorrhage distinctively because 50% of the mice in the tryptase overexpression group had plaque haemorrhage, while only 10% in the siRNA group did. The immunohistochemistry of the cervical artery plaque showed that plasminogen activator inhibitor-1 (PAI-1) expression was the lowest while tissue plasminogen activator (tPA), CD31, CD34 and VEGF was the highest in the tryptase overexpression groups. This observation was completely contrary to what was observed in the siRNA group. Tryptase promoted bEnd.3 cell growth, migration and capillary-like tube formation, which suggests that tryptase can promote microvessel angiogenesis. PAI-1 expression was inhibited, while tPA expression was increased by tryptase in bEnd.3 cells. Our in vivo and in vitro studies suggest that trypase can promote atherosclerotic plaque haemorrhage by promoting angiogenesis and regulating the balance of PAI-1 and tPA. Thus, regulating tryptase expression in MCs may provide a potential target for atherosclerosis treatment.
Tian, Dai; Li, Xiaobo; Ning, Yanxia; Yin, Lianhua
An interactive treatment planning system for ophthalmic plaque radiotherapy.
Brachytherapy using removable episcleral plaques containing sealed radioisotope sources is being studied as an alternative to enucleation in the treatment of choroidal melanoma and other tumors of the eye. Encouraging early results have been reported, but late complications which lead to loss of vision continue to be a problem. A randomized national study, the Collaborative Ocular Melanoma Study (COMS) is currently in progress to evaluate the procedure. The COMS specified isotope is 125I. Precise dosimetric calculations near the plaque may correlate strongly with complications and could also be used to optimize isotope loading patterns in the plaques. A microcomputer based treatment planning system has been developed for ophthalmic plaque brachytherapy. The program incorporates an interactive, 3-dimensional, solid-surface, color-graphic interface. The program currently supports 125I and 192Ir seeds which are treated as anisotropic line sources. Collimation effects related to plaque structure are accounted for, permitting detailed study of shielding effectiveness near the lip of a plaque. A dose distribution matrix may be calculated in any subregion of a transverse, sagittal, or coronal planar cross section of the eye, in any plane transecting the plaque and crossing the eye diametrically, or on a spherical surface within or surrounding the eye. Spherical surfaces may be displayed as 3-dimensional perspective projections or as funduscopic diagrams. Isodose contours are interpolated from the dose matrix. A pointer is also available to explicitly calculate and display dose at any location on the dosimetry surface. An interactive editing capability allows new plaque designs to be rapidly added to the system. PMID:2318702
Astrahan, M A; Luxton, G; Jozsef, G; Kampp, T D; Liggett, P E; Sapozink, M D; Petrovich, Z
The Concomitant Deposition of Strontium and Fluoride in Dental Plaque
We have investigated the feasibility of incorporating Sr into dental plaque by means of an enzyme-dependent system known to increase Ca, P, and F levels in plaque. A solution containing Ca (20 mmoll L), P (12 mmol\\/L), MFP (4.7 mmol\\/L), F (0.3 mmol\\/L), and urea (500 mmol\\/L) was modified by equimolar replacement of Ca with 1, 2, 5, and 10
E. I. F. Pearce; C. H. Sissons
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
Antibacterial effect of taurolidine (2%) on established dental plaque biofilm
Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections.\\u000a However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To\\u000a evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique\\u000a and to compare it with the effect of NaCl and
Nicole Birgit Arweiler; Thorsten Mathias Auschill; Anton Sculean
Methotrexate toxicity presenting as cutaneous ulcerations on psoriatic plaques.
Methotrexate (MTX) is an effective but potentially toxic treatment for psoriasis. We describe a patient who administered 20?mg daily of MTX for 5?d and presented with ulcerated and necrotic lesions on the psoriatic plaques, mouth erosions and hair loss. However, his psoriatic plaques and ulcerations totally healed rapidly within two weeks and no recurrence has been observed for the 6 months of follow up. PMID:23537374
Koçak, Asl?han Yonca; Koçak, O?uzhan; Aslan, Figen; Tekta?, Mustafa
Phenotypic modulation of macrophages in response to plaque lipids
Purpose of review The accumulation of macrophages in the vascular wall is a hallmark of atherosclerosis. The biological properties of atherosclerotic plaque macrophages determine lesion size, composition and stability. In atherosclerotic plaques, macrophages encounter a microenvironment that is comprised of a variety of lipid oxidation products, each of which has diverse biological effects. In this review, we summarize recent advances in our understanding of the effects of plaque lipids on macrophage phenotypic polarization. Recent findings Atherosclerotic lesions in mice and in humans contain various macrophage phenotypes, which play different roles in mediating inflammation, the clearance of dead cells, and possibly resolution. Macrophages alter their phenotype and biological function in response to plaque lipids through the upregulation of specific sets of genes. Interaction of oxidized lipids with pattern recognition receptors and activation of the inflammasome by cholesterol crystals drive macrophages towards an inflammatory M1 phenotype. A new phenotype, Mox, develops when oxidized phospholipids activate stress response genes via Nrf2. Other lipid mediators such as nitrosylated-fatty acids and omega-3 fatty acid-derived products polarize plaque macrophages towards anti-inflammatory and proresolving phenotypes. Summary A deeper understanding of how lipids that accumulate in atherosclerotic plaques affect macrophage phenotype and function and thus atherosclerotic lesion development and stability will help to devise novel strategies for intervention.
Adamson, Samantha; Leitinger, Norbert
Fluorescence lifetime imaging microscopy for the characterization of atherosclerotic plaques
Atherosclerotic plaque composition has been associated with plaque instability and rupture. This study investigates the use of fluorescence lifetime imaging microscopy (FLIM) for mapping plaque composition and assessing features of vulnerability. Measurements were conducted in atherosclerotic human aortic samples using an endoscopic FLIM system (spatial resolution of 35 ?m; temporal resolution 200 ps) developed in our lab which allows mapping in one measurement the composition within a volume of 4 mm diameter × 250 ?m depth. Each pixel in the image represents a corresponding fluorescence lifetime value; images are formed through a flexible 0.6 mm side-viewing imaging bundle which allows for further intravascular applications. Based on previously recorded spectra of human atherosclerotic plaque, fluorescence emission was collected through two filters: f1: 377/50 and f2: 460/60 (center wavelength/bandwidth), which together provides the greatest discrimination between intrinsic fluorophores related to plaque vulnerability. We have imaged nine aortas and lifetime images were retrieved using a Laguerre expansion deconvolution technique and correlated with histopathology. Early results demonstrate discrimination using fluorescence lifetime between early, lipid-rich, and collagen-rich lesions which are consistent with previously reported time-resolved atherosclerotic plaque measurements.
Phipps, Jennifer; Sun, Yinghua; Saroufeem, Ramez; Hatami, Nisa; Marcu, Laura
Reproducibility of IVUS Border Detection for Carotid Atherosclerotic Plaque Assessment
Plaque composition is a potentially important diagnostic feature for carotid artery stenting (CAS). The purpose of this investigation is to evaluate the reproducibility of manual border correction in intravascular ultrasound with virtual histology (VH IVUS) images. Three images each were obtained from 51 CAS datasets on which automatic border detection was corrected manually by two trained observers. Plaque was classified using the definitions from the CAPITAL (Carotid Artery Plaque Virtual Histology Evaluation) study, listed in order from least to most pathological: no plaque, pathological intimal thickening, fibroatheroma, fibrocalcific, calcified fibroatheroma, thin-cap fibroatheroma, and calcified thin-cap fibroatheroma. Inter-observer variability was quantified using both weighted and unweighted Kappa statistics. Bland-Altman analysis was used to compare the cross-sectional areas of the vessel and lumen. Agreement using necrotic core percentage as the criterion was evaluated using the unweighted Kappa statistic. Agreement between classifications of plaque type was evaluated using the weighted Kappa statistic. There was substantial agreement between the observers based on necrotic core percentage (? = 0.63), while the agreement was moderate (?quadratic = 0.60) based on plaque classification. Due to the time-consuming nature of manual border detection, an improved automatic border detection algorithm is necessary for using VH IVUS as a diagnostic tool for assessing the suitability of patients with carotid artery occlusive disease for CAS.
Siewiorek, Gail M.; Loghmanpour, Natasha A.; Winston, Brion M.; Wholey, Mark H.; Finol, Ender A.
Preliminary study of the detectability of coronary plaque with PET
NASA Astrophysics Data System (ADS)
The evaluation of coronary plaque vulnerability could be of great diagnostic value in cardiology. Positron emission tomography (PET) is a good candidate due to its ability to quantify micromolar concentrations of targeted drugs. However, the detectability of sub-voxel targets such as coronary plaque is limited by partial volume effects and by cardiorespiratory motion. The goal of this paper is to investigate the impact of these factors in the detectability of plaque uptake. Radioactive markers were implanted on the epicardium of a pig and in vivo scans were performed. This was complemented with phantom measurements to determine the minimum detectable uptake as a function of background activity. Simulations were used to evaluate the effect of cardiorespiratory motion on the reconstructed lesions. Despite cardiorespiratory motion of up to 7 mm, the markers were detectable in the in vivo scans even after the injection of background. A lower limit of 250 Bq was found for a target to be detectable. Motion reduced the contrast of the reconstructed lesions to 23% of their static counterpart. Respiratory gating improved this to 49% of the static value. The results suggest that coronary plaque evaluation with PET is possible, provided that sufficient plaque-to-myocardium uptake contrast (50 to 100) can be achieved. This requirement increases exponentially for lesions with uptake below 250 Bq. The described experiments provide a means of estimating the minimum uptake and contrast required to ensure the detectability of plaque lesions.
Delso, G.; Martinez-Möller, A.; Bundschuh, R. A.; Nekolla, S. G.; Ziegler, S. I.; Schwaiger, M.
Microglial cells are the driving force in fibrillar plaque formation, whereas astrocytes are a leading factor in plaque degradation
Ultrastructural three-dimensional reconstruction of human classical plaques in different stages of development shows that\\u000a microglial cells are the major factor driving plaque formation by fibrillar amyloid-? (A?) deposition. The amount of fibrillar\\u000a A? released by microglial cells and the area of direct contact between amyloid and neuron determine the extent of dystrophic\\u000a changes in neuronal processes and synapses. The volume
Jerzy Wegiel; Kuo-Chiang Wang; Michal Tarnawski; Boleslaw Lach
Antibacterial effect of taurolidine (2%) on established dental plaque biofilm.
Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections. However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique and to compare it with the effect of NaCl and chlorhexidine (CHX), 18 subjects had to refrain from all mechanical and chemical hygiene measures for 24 h. A voluminous supragingival plaque sample was taken from the buccal surfaces of the lower molars and wiped on an objective slide. The sample was then divided into three equal parts and mounted with one of the three test or control preparations (a) NaCl, (b) taurolidine 2% and (c) CHX 0.2%. After a reaction time of 2 min, the test solutions were sucked of. Subsequently, the plaque biofilm was stained with fluorescence dye and vitality of the plaque flora was evaluated under the fluorescence microscope (VF%). Plaque samples treated with NaCl showed a mean VF of 82.42?±?6.04%. Taurolidine affected mean VF with 47.57?±?16.60% significantly (p?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. PMID:21360105
Arweiler, Nicole Birgit; Auschill, Thorsten Mathias; Sculean, Anton
Raised Soluble P-Selectin Moderately Accelerates Atherosclerotic Plaque Progression
Soluble P-selectin (sP-selectin), a biomarker of inflammatory related pathologies including cardiovascular and peripheral vascular diseases, also has pro-atherosclerotic effects including the ability to increase leukocyte recruitment and modulate thrombotic responses in vivo. The current study explores its role in progressing atherosclerotic plaque disease. Apoe?/? mice placed on a high fat diet (HFD) were given daily injections of recombinant dimeric murine P-selectin (22.5 µg/kg/day) for 8 or 16 weeks. Saline or sE-selectin injections were used as negative controls. In order to assess the role of sP-selectin on atherothrombosis an experimental plaque remodelling murine model, with sm22?-hDTR Apoe?/? mice on a HFD in conjunction with delivery of diphtheria toxin to induce targeted vascular smooth muscle apoptosis, was used. These mice were similarly given daily injections of sP-selectin for 8 or 16 weeks. While plaque mass and aortic lipid content did not change with sP-selectin treatment in Apoe?/? or SM22?-hDTR Apoe?/? mice on HFD, increased plasma MCP-1 and a higher plaque CD45 content in Apoe?/? HFD mice was observed. As well, a significant shift towards a more unstable plaque phenotype in the SM22?-hDTR Apoe?/? HFD mice, with increased macrophage accumulation and lower collagen content, leading to a lower plaque stability index, was observed. These results demonstrate that chronically raised sP-selectin favours progression of an unstable atherosclerotic plaque phenotype.
Andrews, Karen L.; Aprico, Andrea; Harris, Emma; Irvine, Jennifer C.; Jefferis, Ann-maree; Fang, Lu; Kanellakis, Peter; Bobik, Alex; Chin-Dusting, Jaye P. F.
Survival of human dental plaque flora in various transport media.
Dental plaque samples from (i) subjects with no apparent oral disease, (ii) mentally retarded subjects with periodontal disease, and (iii) subjects with active caries were collected in three transport media viz. a dithiothreitol poised balanced mineral salt solution designated as reduced transport fluid (RTF), VMG II, and modified Stuart medium (SBL). The samples were dispersed by sonic treatment, diluted in the respective medium in which they were collected, and cultured on MM10 sucrose agar. The efficiency of the transport media in the survival of dental plaque flora was determined by comparing the quantitative recovery (expressed as percentage of the initial viable count) from the specimens stored for various lengths of time. The data showed a great variation in the recovery of the oral bacterial flora from the plaque samples. VMG II and SBL served better than RTF as storage media for non-disease-associated dental plaque cultured under strict anaerobic conditions. Recoveries of bacteria from periodontal plaque specimens stored in RTF were higher than SBL and VMG II under identical conditions. The organisms present in the carious plaque samples appeared to survive much better in RTF and VMG II than in SBL as determined by conventional anaerobic culturing technique. However, VMG II showed a higher recovery of organisms from these specimens with an increase in the storage period, suggesting multiplication of the plaque flora. RTF did not allow the growth of oral bacterial flora under all experimental conditions. On the basis of the relative performance of these media it is suggested that RTF is a satisfactory medium for the transport of oral bacteria present in the samples. PMID:4628799
Syed, S A; Loesche, W J
Survival of Human Dental Plaque Flora in Various Transport Media
Dental plaque samples from (i) subjects with no apparent oral disease, (ii) mentally retarded subjects with periodontal disease, and (iii) subjects with active caries were collected in three transport media viz. a dithiothreitol poised balanced mineral salt solution designated as reduced transport fluid (RTF), VMG II, and modified Stuart medium (SBL). The samples were dispersed by sonic treatment, diluted in the respective medium in which they were collected, and cultured on MM10 sucrose agar. The efficiency of the transport media in the survival of dental plaque flora was determined by comparing the quantitative recovery (expressed as percentage of the initial viable count) from the specimens stored for various lengths of time. The data showed a great variation in the recovery of the oral bacterial flora from the plaque samples. VMG II and SBL served better than RTF as storage media for non-disease-associated dental plaque cultured under strict anaerobic conditions. Recoveries of bacteria from periodontal plaque specimens stored in RTF were higher than SBL and VMG II under identical conditions. The organisms present in the carious plaque samples appeared to survive much better in RTF and VMG II than in SBL as determined by conventional anaerobic culturing technique. However, VMG II showed a higher recovery of organisms from these specimens with an increase in the storage period, suggesting multiplication of the plaque flora. RTF did not allow the growth of oral bacterial flora under all experimental conditions. On the basis of the relative performance of these media it is suggested that RTF is a satisfactory medium for the transport of oral bacteria present in the samples.
Syed, Salam A.; Loesche, Walter J.
Association between Variations in Coagulation System Genes and Carotid Plaque
Objective Genetic variation in coagulation and fibrinolysis may affect the development of subclinical atherosclerosis modifying the risk of stroke and cardiovascular disease. However, data on the relationship between subclinical atherosclerosis and genes involved in the coagulation system are sparse. The objective of this study is to examine the association between single nucleotide polymorphisms (SNPs) in coagulation system genes and subclinical carotid plaque phenotypes. Methods From the Genetic Determinants of Subclinical Carotid Disease study, 287 Dominicans were examined for carotid plaque presence, thickness, and surface irregularity by high-resolution B-mode carotid ultrasound. Logistic regression was used to test for association between 101 SNPs in 23 coagulation system genes and plaque phenotypes while controlling for age, sex, smoking, hypertension, dyslipidemia, and diabetes. Within gene haplotypes and interactions between genes were examined. A follow-up of SNPs in moderate to high (r2>0.25) linkage disequilibrium (LD) with those implicated in the discovery analysis (p?0.01) was performed in an independent sample of 301 Dominicans. Results The prevalence of carotid plaque (47% discovery; 46% follow-up) as well as the mean age (65±8 discovery; 65±9 follow-up) of the participants was similar in both datasets. Two genes (vWF and THBS1) were associated (p?0.01) with plaque size and surface irregularity. In followup, 5 SNPs in vWF were associated (p?0.05) with plaque size. SERPINE1 was an additional gene of interest in the haplotype and interaction analyses. Conclusions Variation in the vWF, THBS1, and SERPINE1 gene may play an important role in the pathogenesis of atherosclerotic plaque.
Della-Morte, David; Beecham, Ashley; Dong, Chuanhui; Wang, Liyong; McClendon, Mark S.; Gardener, Hannah; Blanton, Susan H.; Sacco, Ralph L.; Rundek, Tatjana
Asbestos fibers and pleural plaques in a general autopsy population.
It has been claimed that symmetric lower zone pleural or diaphargmatic plaques are markers of asbestos exposure both in asbestos workers and the general population. In this study, total pulmonary asbestos burden was analyzed for 29 patients selected because pleural plaques were found at autopsy, and the results were compared with values obtained for 25 patients who had no occupational asbestos exposure. The average number of asbestos bodies in the plaque groups was 1732/g wet lung, and in the control group, 42/g wet lung. Uncoated asbestos fibers were extracted from lung and counted, measured, and identified by morphologic examination, electron diffraction, and energy-dispersive x-ray spectroscopy. The total number of fibers/per gram wet lung in the plaque group (114 x 10(3)) was similar to that in the control group (99 x 10(3), as was the number of chrysotile fibers (51 x 10(3) versus 29 x 10(3)). However, the plaque patients had a marked increase in the number of the commercially used high aspect ratio amphiboles, amosite and crocidolite (50 x 10(3) versus 1 x 10(3). A retrospective history of fairly certain asbestos exposure was obtained for 16 of the plaque patients, and such a history correlated strongly with increased numbers of commercial amphiboles in lung. It is concluded that 1) in this general autopsy population, two subgroups of patients are present. About one half of the patients appear to have developed pleural plaques as a result of asbestos exposure, while the etiology of the plaques in the other half is unclear; 2) the presence of pleural plaques correlates with a modest (50-fold) increase in numbers of long high-aspect ratio commercial amphiboles in lung tissue but does not correlate with numbers of chrysotile fibers, noncommercial amphiboles, or the total number of asbestos fibers; 3) asbestos-induced lesions are related to a complex set of mineralogic parameters and not to mere numbers of fibers in lung. PMID:7124910
Churg, A
[Endemic pleural plaques and environmental factors (author's transl)].
In an agricultural town in Burgenland (Austria) we found an increased prevalence of pleural plaques. These calcifying thickenings of the pleura are related to minimal asbestos exposure such as is mesothelioma, but they cannot be regarded as a precancerosis. The increased occurrence of pleural plaques in this town of nearly 3500 inhabitants (in which during 1916 to 1945 asbestos was mined) we first found at the chest x-ray archives of a pulmologic hospital, then by mass radiography and blind comparison with control groups. A photofluoroscopy of 300 persons yielded 16 cases with definite pleural plaques (5.3%) among which were 4 cases with suspected asbestosis and another 14 cases with uncertain pleural plaques (4.7%). The 600 control persons showed no such radiological changes. Interviews wich persons detected for pleural plaques at mass radiography gave no indication that they had occupational asbestos exposure. But asbestos was detected in the soil of vineyards and in the dust of the houses. Asbestos was also detectable in the atmospheric dust by x-ray diffraction and scanning electron microscopic techniques. PMID:749422
Neuberger, M; Gründorfer, W; Haider, M; Königshofer, R; Müller, H W; Raber, A; Riedmüller, G; Schwaighofer, B
The vulnerable coronary plaque: update on imaging technologies.
Several studies have been carried out on vulnerable plaque as the main culprit for ischaemic cardiac events. Historically, the most important diagnostic technique for studying coronary atherosclerotic disease was to determine the residual luminal diameter by angiographic measurement of the stenosis. However, it has become clear that vulnerable plaque rupture as well as thrombosis, rather than stenosis, triggers most acute ischaemic events and that the quantification of risk based merely on severity of the arterial stenosis is not sufficient. In the last decades, substantial progresses have been made on optimisation of techniques detecting the arterial wall morphology, plaque composition and inflammation. To date, the use of a single technique is not recommended to precisely identify the progression of the atherosclerotic process in human beings. In contrast, the integration of data that can be derived from multiple methods might improve our knowledge about plaque destabilisation. The aim of this narrative review is to update evidence on the accuracy of the currently available non-invasive and invasive imaging techniques in identifying components and morphologic characteristics associated with coronary plaque vulnerability. PMID:23803753
Rosa, Gian Marco; Bauckneht, Matteo; Masoero, Giovanni; Mach, François; Quercioli, Alessandra; Seitun, Sara; Balbi, Manrico; Brunelli, Claudio; Parodi, Antonello; Nencioni, Alessio; Vuilleumier, Nicolas; Montecucco, Fabrizio
Low copper and high manganese levels in prion protein plaques
Accumulation of aggregates rich in an abnormally folded form of the prion protein characterize the neurodegeneration caused by transmissible spongiform encephalopathies (TSEs). The molecular triggers of plaque formation and neurodegeneration remain unknown, but analyses of TSE-infected brain homogenates and preparations enriched for abnormal prion protein suggest that reduced levels of copper and increased levels of manganese are associated with disease. The objectives of this study were to: (1) assess copper and manganese levels in healthy and TSE-infected Syrian hamster brain homogenates; (2) determine if the distribution of these metals can be mapped in TSE-infected brain tissue using X-ray photoelectron emission microscopy (X-PEEM) with synchrotron radiation; and (3) use X-PEEM to assess the relative amounts of copper and manganese in prion plaques in situ. In agreement with studies of other TSEs and species, we found reduced brain levels of copper and increased levels of manganese associated with disease in our hamster model. We also found that the in situ levels of these metals in brainstem were sufficient to image by X-PEEM. Using immunolabeled prion plaques in directly adjacent tissue sections to identify regions to image by X-PEEM, we found a statistically significant relationship of copper-manganese dysregulation in prion plaques: copper was depleted whereas manganese was enriched. These data provide evidence for prion plaques altering local transition metal distribution in the TSE-infected central nervous system.
Johnson, Christopher J.; Gilbert, P. U. P. A.; Abrecth, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; McKenzie, Debbie
Infliximab in the treatment of plaque type psoriasis
Psoriasis is a chronic and immunomediated skin disease characterized by erythematous scaly plaques. Psoriasis affects approximately 1% to 3% of the Caucasian population. Tumor necrosis factor alpha (TNF-?) is a proinflammatory cytokine that plays a critical role in the pathogenesis of psoriasis. Infliximab is an anti-TNF-? drug widely used for the treatment of plaque type psoriasis and psoriatic arthritis. Controlled clinical trials demonstrated that infliximab is characterized by a high degree of clinical response in moderate to severe plaque psoriasis. Moreover infliximab showed rapid efficacy in nail psoriasis which represents a therapeutic challenge for dermatologists and a relevant source of distress for patients with plaque psoriasis. This anti-TNF-? has an encouraging safety profile, especially as long as physicians are watchful in prevention and early diagnosis of infections and infuse reactions. The efficacy, tolerability and safety profiles suggest infliximab as a suitable anti-psoriatic drug in the long-term treatment of a chronic disease such as plaque-type psoriasis.
Saraceno, Rosita; Saggini, Andrea; Pietroleonardo, Lucia; Chimenti, Sergio
Laser speckle imaging of atherosclerotic plaques through optical fiber bundles
Laser speckle imaging (LSI), a new technique that measures an index of plaque viscoelasticity, has been investigated recently to characterize atherosclerotic plaques. These prior studies demonstrated the diagnostic potential of LSI for detecting high-risk plaques and were conducted ex vivo. To conduct intracoronary LSI in vivo, the laser speckle pattern must be transmitted from the coronary wall to the image detector in the presence of cardiac motion. Small-diameter, flexible optical fiber bundles, similar to those used in coronary angioscopy, may be incorporated into an intravascular catheter for this purpose. A key challenge is that laser speckle is influenced by inter-fiber leakage of light, which may be exacerbated during bundle motion. In this study, we tested the capability of optical fiber bundles to transmit laser speckle patterns obtained from atherosclerotic plaques and evaluated the influence of motion on the diagnostic accuracy of fiber bundle-based LSI. Time-varying helium-neon laser speckle images of aortic plaques were obtained while cyclically moving the flexible length of the bundle to mimic coronary motion. Our results show that leached fiber bundles may reliably transmit laser speckle images in the presence of cardiac motion, providing a viable option to conduct intracoronary LSI.
Nadkarni, Seemantini K.; Bouma, Brett E.; Yelin, Dvir; Gulati, Amneet; Tearney, Guillermo J.
Uniaxial tensile testing approaches for characterisation of atherosclerotic plaques.
The pathological changes associated with the development of atherosclerotic plaques within arterial vessels result in significant alterations to the mechanical properties of the diseased arterial wall. There are several methods available to characterise the mechanical behaviour of atherosclerotic plaque tissue, and it is the aim of this paper to review the use of uniaxial mechanical testing. In the case of atherosclerotic plaques, there are nine studies that employ uniaxial testing to characterise mechanical behaviour. A primary concern regarding this limited cohort of published studies is the wide range of testing techniques that are employed. These differing techniques have resulted in a large variance in the reported data making comparison of the mechanical behaviour of plaques from different vasculatures, and even the same vasculature, difficult and sometimes impossible. In order to address this issue, this paper proposes a more standardised protocol for uniaxial testing of diseased arterial tissue that allows for better comparisons and firmer conclusions to be drawn between studies. To develop such a protocol, this paper reviews the acquisition and storage of the tissue, the testing approaches, the post-processing techniques and the stress-strain measures employed by each of the nine studies. Future trends are also outlined to establish the role that uniaxial testing can play in the future of arterial plaque mechanical characterisation. PMID:24508324
Walsh, M T; Cunnane, E M; Mulvihill, J J; Akyildiz, A C; Gijsen, F J H; Holzapfel, G A
Plaque Assay of Rickettsiae in a Mammalian Cell Line
Clear-cut and repeatable plaque assays were obtained for three rickettsiae of the spotted fever group (Rickettsia rickettsi, R. conori, and R. montana) in Vero cells used in a manner similar to that for arboviruses. In addition, three typhus group agents (R. typhi, R. canada, R. prowazeki) induced plaques in these cells. In preliminary tests Coxiella burneti (Nine Mile strain) failed to produce plaques. Comparable results were obtained in plastic flasks and plastic culture trays incubated in ambient air with or without addition of N-2-hydroxyethyl-piperazine-N?-2-ethanesulfinic acid buffer. Larger and more well defined R. rickettsi plaques were produced when cultures were overlaid with Leibovitz (L15) medium than with either medium 199 or Eagle medium. Phosphate-buffered saline containing bovine plasma albumin (fraction V), in contrast to brain heart infusion broth, as a diluent for preparing inocula consistently permitted development of larger and more numerous plaques with three agents: R. rickettsi, R. conori, and R. montana. When R. rickettsi and R. typhi were assayed in parallel in primary chicken embryo cultures and Vero cells, comparable results were obtained, but with R. canada results in Vero cells were superior. In contrast, R. prowazeki produced inconsistent results in Vero cells. Images
Cory, J.; Yunker, C. E.; Ormsbee, R. A.; Peacock, M.; Meibos, H.; Tallent, G.
Plaque assay of rickettsiae in a mammalian cell line.
Clear-cut and repeatable plaque assays were obtained for three rickettsiae of the spotted fever group (Rickettsia rickettsi, R. conori, and R. montana) in Vero cells used in a manner similar to that for arboviruses. In addition, three typhus group agents (R. typhi, R. canada, R. prowazeki) induced plaques in these cells. In preliminary tests Coxiella burneti (Nine Mile strain) failed to produce plaques. Comparable results were obtained in plastic flasks and plastic culture trays incubated in ambient air with or without addition of N-2-hydroxyethyl-piperazine-N'-2-ethanesulfinic acid buffer. Larger and more well defined R. rickettsi plaques were produced when cultures were overlaid with Leibovitz (L15) medium than with either medium 199 or Eagle medium. Phosphate-buffered saline containing bovine plasma albumin (fraction V), in contrast to brain heart infusion broth, as a diluent for preparing inocula consistently permitted development of larger and more numerous plaques with three agents: R. rickettsi, R. conori, and R. montana. When R. rickettsi and R. typhi were assayed in parallel in primary chicken embryo cultures and Vero cells, comparable results were obtained, but with R. canada results in Vero cells were superior. In contrast, R. prowazeki produced inconsistent results in Vero cells. PMID:4208640
Cory, J; Yunker, C E; Ormsbee, R A; Peacock, M; Meibos, H; Tallent, G
Radiolabeled probes for imaging Alzheimer's plaques
NASA Astrophysics Data System (ADS)
Alzheimer's disease (AD) is a debilitating disease characterized by the presence of extra-cellular plaques and intra-cellular neurofibrillary tangles (NFTs) in the brain. The major protein component of these plaques is beta amyloid peptide (A?), a 40-42 amino acid peptide cleaved from amyloid precursor protein (APP) by ?-secretase and a putative ?-secretase. We radioiodinated quinoline derivatives (clioquinol and oxine) and evaluated them as potential amyloid imaging agents based on their ability to cross the blood brain barrier (BBB) and on their selectivity to metal binding sites on amyloid plaques. The uptake of theses tracers in the brains of normal swiss-webster mice was rapid and so was the clearance. Selectivity was demonstrated by higher binding to AD brain homogenates compared to normal brain. Autoradiographic studies demonstrated the localization of the tracers in the plaque regions of the AD brain sections as well as in liver tissue with amyloidosis. Further optimization and evaluations would likely lead to development of these molecules as AD plaque imaging agents.
Kulkarni, P. V.; Arora, V.; Roney, A. C.; White, C.; Bennett, M.; Antich, P. P.; Bonte, F. J.
SMC-Specific IGF-1 Overexpression in Apoe?/? Mice Does Not Alter Atherosclerotic Plaque Burden but Increases Features of Plaque Stability
Objective Growth factors may play a permissive role in atherosclerosis initiation and progression, in part via their promotion of VSMC accumulation in plaques. However, unstable human plaques often have a relative paucity of VSMC which has been suggested to contribute to plaque rupture and/or erosion and to clinical events. IGF-1 is an endocrine and autocrine/paracrine growth factor that is a mitogen for VSMC, but when infused into Apoe?/? mice paradoxically reduces atherosclerosis burden. Methods & Results To determine the effect of stimulation of VSMC growth on atherosclerotic plaque development and to understand mechanisms of IGF-1's atheroprotective effect we assessed atherosclerotic plaques in mice overexpressing IGF-1 in SMC under the control of the ?SMA promoter, after backcrossing to the Apoe?/? background (SMP8/Apoe?/?). When compared with Apoe?/? mice these SMP8/Apoe?/? mice developed comparable plaque burden after 12 wks on a Western diet, suggesting that the ability of increased circulating IGF-1 to reduce plaque burden was mediated in large part via non-SMC target cells. However, advanced plaques in SMP8/Apoe?/? mice displayed several features of plaque stability, including increased fibrous cap area, ?SMA positive SMC and collagen content and reduced necrotic cores. Conclusion These findings indicate that stimulation of VSMC IGF-1 signaling does not alter total atherosclerotic plaque burden and may improve atherosclerotic plaque stability.
Shai, Shaw-Yung; Sukhanov, Sergiy; Higashi, Yusuke; Vaughn, Charlotte; Kelly, James; Delafontaine, Patrice
Plaque Vulnerability in Internal Carotid Arteries with Positive Remodeling
Background This study aimed to evaluate the efficacy of assessing positive remodeling for predicting future stroke events in the internal carotid artery. We therefore assessed narrowing of the carotid artery lumen using multidetector-row computer tomography (MDCT) angiography and carotid plaque characteristics using black-blood (BB) magnetic resonance (MR). Methods We retrospectively selected 17 symptomatic and 11 asymptomatic lesions with luminal narrowing >50%. We compared remodeling parameters of luminal stenosis (remodeling ratio, RR/remodeling index, RI) using MDCT and MR intensities of atherosclerotic plaque contents using the BB technique (relative signal intensity, rSI). We also confirmed the validity of the relationship between MR intensity and atherosclerotic plaque contents by histology. The levels of biological markers related to vessel atherosclerosis were measured. Results Plaque lesions with positive remodeling in carotid arteries were associated with a significantly higher prevalence of stroke compared with plaques with negative remodeling (p < 0.05). Radiologic and histologic analyses determined that plaques with positive remodeling had higher signal intensities (with respect to their lipid-rich content or to hemorrhage) compared with negative remodeling (correlation coefficients: RI and rSI, r = 0.41, p < 0.05; RR and rSI, r = 0.50, p < 0.05). Levels of biological markers, including high-sensitivity C-reactive protein, hemoglobin A1C, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, were not useful for predicting stroke events. Conclusions The results of this study suggest that the combined analysis of RR, RI and rSI could potentially help to predict future stroke events.
Miura, Toshiyasu; Matsukawa, Noriyuki; Sakurai, Keita; Katano, Hiroyuki; Ueki, Yoshino; Okita, Kenji; Yamada, Kazuo; Ojika, Kosei
The apical border plaque in severe periodontitis. An ultrastructural study.
This study concerns the apical border (AB) plaque in relation to severe forms of periodontitis (SP), including juvenile, post-juvenile, and rapidly progressing periodontitis. Twenty-four (24) teeth from 16 patients with SP were examined by transmission electron microscopy (TEM). The AB was not discrete, with islands of bacteria in the so-called plaque-free zone (PFZ). Coronal to the AB the established plaque consisted of a layer of Gram-positive cocci and ghost cells and a superficial layer mainly of Gram-negative morphotypes, including cocci, rods, filaments, fusiforms, and spirochetes. The most apical apparently intact organisms in the PFZ were in bacterial islands or in isolation and were predominantly Gram-negative cocci and rods, with ghost cells in abundance. Ruthenium red, alcian blue-lanthanum nitrate, and safranin O were used to label matrix polyanionic macromolecules, and periodic acid (thiosemicarbazide) silver proteinate for intracellular polysaccharide (IPS). The matrix components were mainly fibrillar. Many intact bacteria exhibited extracellular polysaccharides or glycocalyces associated with their cell wall, and cytoplasmic IPS granules. The latter varied in distribution and were evident even in the most apically advanced intact microorganisms. The results indicate that IPS and some matrix features of the apical border plaque in severe periodontitis in certain aspects resemble those of sub-contact area plaque on children's teeth, in health or associated with early chronic gingivitis, and with those in chronic adult periodontitis. They also suggest the establishment of acidic regions in the microniche at the bottom of the periodontal pocket in the various forms of periodontitis differing in rate of progression. It was concluded that there was a limited range of intact bacterial morphotypes in the apical border plaque in severe periodontitis, similar to those in chronic adult periodontitis. PMID:7537328
Vrahopoulos, T P; Barber, P M; Newman, H N
Buffering effect of a prophylactic gel on dental plaque.
The aim of this study was to evaluate the effect of a new prophylactic gel on plaque pH and plaque fluoride concentration. Twelve participants with normal (n=6, >or=0.7 ml/min) and low (n=6, <0.7 ml/min) stimulated whole salivary secretion rate were included. After 3 days of plaque accumulation, at random the participants were (1) treated with Profylin fluoride gel with buffering components (active gel), (2) treated with Profylin fluoride gel without buffering components (placebo gel), (3) asked to rinse with water, and (4) given no treatment. All test series were followed by rinsing with a nutrition solution; after which registration of plaque pH was performed during 60 min. There were two drop outs with low salivary secretion rate in the water session. The overall least pronounced pH fall was found after the use of the prophylactic gel. Significant differences between the prophylactic gel and the placebo gel were found for the participants with normal secretion rate. Fluoride plaque concentrations evaluated in 12 individuals after (1) application of the active gel, (2) rinsing with 0.2% NaF, and (3) rinsing with water showed significantly higher values after rinsing with the NaF solution. It can be concluded that application of the active gel, particularly in subjects with normal salivary secretion rate, in general, buffered plaque pH to higher levels. Factors like concentration of buffering agent and solubility of the gel need to be further evaluated to improve the effect. PMID:16937109
Persson, Anitha; Lingström, Peter; Bergdahl, Maud; van Dijken, Jan W V
Bifurcation analysis of a model for atherosclerotic plaque evolution
NASA Astrophysics Data System (ADS)
We analyze two ordinary differential equation (ODE) models for atherosclerosis. The ODE models describe long time evolution of plaques in arteries. We show how the dynamics of the first atherosclerosis model (model A) can be understood using codimension-two bifurcation analysis. The Low-Density Lipoprotein (LDL) intake parameter (d) is the first control parameter and the second control parameter is either taken to be the conversion rate of macrophages (b) or the wall shear stress (?). Our analysis reveals that in both cases a Bogdanov-Takens (BT) point acts as an organizing center. The bifurcation diagrams are calculated partly analytically and to a large extent numerically using AUTO07 and MATCONT. The bifurcation curves show that the concentration of LDL in the plaque as well as the monocyte and the macrophage concentrations exhibit oscillations for a certain range of values of the control parameters. Moreover, we find that there are threshold values for both the cholesterol intake rate d and the conversion rate of the macrophages b, which depend on the values of other parameters, above which the plaque volume increases with time. It is found that larger conversion rates of macrophages lower the threshold value of cholesterol intake and vice versa. We further argue that the dynamics for model A can still be discerned in the second model (model B) in which the slow evolution of the radius of the artery is coupled self-consistently to changes in the plaque volume. The very slow evolution of the radius of the artery compared to the other processes makes it possible to use a slow manifold approximation to study the dynamics in this case. We find that in this case the model predicts that the concentrations of the plaque constituents may go through a period of oscillations before the radius of the artery will start to decrease. These oscillations hence act as a precursor for the reduction of the artery radius by plaque growth.
Bulelzai, M. A. K.; Dubbeldam, J. L. A.; Meijer, H. G. E.
Multispectral optoacoustic tomography resolves smart probe activation in vulnerable plaques
NASA Astrophysics Data System (ADS)
In this work, we show, for the first time to our knowledge, that multispectral optoacoustic tomography (MSOT) can deliver high resolution images of activatable molecular probe's distribution, sensitive to matrix metalloproteinases (MMP), deep within optically scattering human carotid specimen. It is further demonstrated that this method can be used in order to provide accurate maps of vulnerable plaque formations in atherosclerotic disease. Moreover, optoacoustic images can simultaneously show the underlining plaque morphology for accurate localization of MMP activity in three dimensions. This performance directly relates to small animal screening applications and to clinical potential as well.
Razansky, Daniel; Harlaar, Niels J.; Hillebrands, Jan-Luuk; Taruttis, Adrian; Herzog, Eva; Zeebregts, Clark; van Dam, Goitzen; Ntziachristos, Vasilis
Dosimetric study of the 15 mm ROPES eye plaque
The main aim of this paper is to make a study of dose-rate distributions obtained around the 15 mm, radiation oncology physics and engineering services, Australia (ROPES) eye plaque loaded with {sup 125}I model 6711 radioactive seeds. In this study, we have carried out a comparison of the dose-rate distributions obtained by the algorithm used by the Plaque Simulator (PS) (BEBIG GmbH, Berlin, Germany) treatment planning system with those obtained by means of the Monte Carlo method for the ROPES eye plaque. A simple method to obtain the dose-rate distributions in a treatment planning system via the superposition of the dose-rate distributions of a seed placed in the eye plaque has been developed. The method uses eye plaque located in a simplified geometry of the head anatomy and distributions obtained by means of the Monte Carlo code GEANT4. The favorable results obtained in the development of this method suggest that it could be implemented on a treatment planning system to improve dose-rate calculations. We have also found that the dose-rate falls sharply along the eye and that outside the eye the dose-rate is very low. Furthermore, the lack of backscatter photons from the air located outside the eye-head phantom produces a dose reduction negligible for distances from the eye-plaque r<1 cm but reaches up to 20% near the air-eye interface. Results showed that the treatment planning system lacks accuracy around the border of the eye (in the sclera and the surrounding area) due to the simplicity of the algorithm used. The BEBIG treatment planning system uses a global attenuation factor that takes into account the effect of the eye plaque seed carrier and the lack of backscatter photons caused by the metallic cover, which in the case of a ROPES eye plaque has a default value of T=1 (no correction). In the present study, a global attenuation factor T=0.96 and an air-interface correction factor which improve on treatment planning system calculations were obtained.
Granero, D.; Perez-Calatayud, J.; Ballester, F.; Casal, E.; Frutos, J.M. de [Department of Atomic, Molecular and Nuclear Physics and IFIC, University of Valencia-CSIC, Dr. Moliner 50, E46100 Burjassot (Spain); Medical Physics Section, University Hospital, Av. Ramon y Cajal 3, E47011 Valladolid (Spain)
Dosimetry and physical treatment planning for iodine eye plaque therapy
The dosimetry of eye plaques loaded with iodine-125 seeds (type 6702) was performed by means of computer calculations and measurements with thermoluminescent dosimeters (TLD). Measurements of the depth dose distribution (2-25.5 mm) along the transverse axis of a single seed were performed in water equivalent phantom material. The transverse axis attenuation and geometry factor F(r) was obtained by applying a least squares fit to the measured data. Based on the resulting radial dose function, a computer program was developed which calculates dose distributions within the eye for arbitrary loading and placement of the eye plaque. The computational results were verified by TLD measurements in an eye phantom.
Alberti, W.; Pothmann, B.; Tabor, P.; Muskalla, K.; Hermann, K.P.; Harder, D. (Alfried Krupp Krankenhaus, Essen, (F.R.Germany))
Is there a role for coronary angiography in the early detection of the vulnerable plaque?
The identification of the coronary "vulnerable plaque" that is prone to disruption and thrombosis remains a "holy grail" in the treatment of coronary artery disease. The widespread use of coronary angiography for the identification of coronary atherosclerotic disease has led to numerous earlier studies exploring the role of angiography in the early detection of the vulnerable plaque. Some of the angiographic features explored for risk of plaque rupture include the degree of luminal stenosis, presence of plaque calcification, complex lesions with plaque disruption and thrombosis, and coronary artery movement patterns. However, a major limiting factor with coronary angiography is that it is a "luminogram", and provides little characterization of plaque morphology or vessel wall, both of which play an important role in the development of plaque vulnerability. Newer intravascular imaging techniques have been developed to permit more detailed interrogation of plaque morphology and vessel wall, potentially allowing for more accurate detection of plaque vulnerability. Whilst coronary angiography may be increasingly superseded by these advances in imaging technologies, it is likely that it will continue to play an important complementary role in the quest for the early detection of the vulnerable plaque. The prospective identification of the vulnerable plaque currently remains elusive, as definitive tools for its detection do not exist. Hence, further prospective studies on the natural history of the atherosclerotic plaque, as well as validation of imaging modalities in clinical studies are needed before the notion of early detection of the vulnerable plaque becomes a clinical reality. PMID:22289298
Chan, Kim Hoe; Ng, Martin K C
Dynamics of the Microglial/Amyloid Interaction Indicate a Role in Plaque Maintenance
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.
Bolmont, Tristan; Haiss, Florent; Eicke, Daniel; Radde, Rebecca; Mathis, Chester A.; Klunk, William E.; Kohsaka, Shinichi; Jucker, Mathias
An assessment of the vulnerability of carotid plaques: a comparative study between intraplaque neovascularization and plaque echogenicity
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.
Multimodal characterization of compositional, structural and functional features of human atherosclerotic plaques
Detection of atherosclerotic plaque vulnerability has critical clinical implications for avoiding sudden death in patients with high risk of plaque rupture. We report on multimodality imaging of ex-vivo human carotid plaque samples using a system that integrates fluorescence lifetime imaging (FLIM), ultrasonic backscatter microscopy (UBM), and photoacoustic imaging (PAI). Biochemical composition is differentiated with a high temporal resolution and sensitivity at the surface of the plaque by the FLIM subsystem. 3D microanatomy of the whole plaque is reconstructed by the UBM. Functional imaging associated with optical absorption contrast is evaluated from the PAI component. Simultaneous recordings of the optical, ultrasonic, and photoacoustic data present a wealth of complementary information concerning the plaque composition, structure, and function that are related to plaque vulnerability. This approach is expected to improve our ability to study atherosclerotic plaques. The multimodal system presented here can be translated into a catheter based intraluminal system for future clinical studies.
Sun, Yang; Chaudhari, Abhijit J.; Lam, Matthew; Xie, Hongtao; Yankelevich, Diego R.; Phipps, Jennifer; Liu, Jing; Fishbein, Michael C.; Cannata, Jonathan M.; Shung, K. Kirk; Marcu, Laura
Plaque Formation Compared on Surfaces of Stannous Fluoride-Containing and Conventional Amalgams.
National Technical Information Service (NTIS)
Clinical trials of an amalgam restorative material containing 1.5% sodium fluoride by weight have revealed a definite reduction in plaque formation, perhaps due to the bacteriostatic effect on the organisms within the plaque. This amalgam does not appear ...
A. C. Jerman R. J. Winkworth
21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.
21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.
Code of Federal Regulations, 2010 CFR
...device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical means. The device type includes those devices that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b)...
21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.
Code of Federal Regulations, 2011 CFR
...device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical means. The device type includes those devices that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b)...
21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.
Code of Federal Regulations, 2012 CFR
...device intended to reduce the presence of bacterial plaque on teeth and oral mucosal surfaces by physical means. The device type includes those devices that act by reducing the attachment and inhibiting the growth of bacterial plaque. (b)...
Microflora and chemical composition of dental plaque from subjects with hereditary fructose intolerance.
We compared the microbiological and chemical composition of dental plaque from subjects with hereditary fructose intolerance who restrict their dietary sugar intake with that of control subjects who do not. The two groups showed no significant differences in chemical composition of plaque: the mean protein, carbohydrate, calcium, magnesium, and phosphate contents were similar. Dental plaque from both groups contained similar numbers of total colony-forming units per microgram of plaque protein, and Streptococcus sanguis, an indigenous nonpathogen, was isolated with equal frequency from plaque samples of both groups. However, potentially odontopathic Streptococcus mutans and Lactobacillus were isolated three to four times more frequently from plaque samples of control subjects than from plaque samples of subjects with hereditary fructose intolerance. Clearly, diet (sucrose in particular) influences the colonization and multiplication of specific cariogenic organisms in dental plaque.
Hoover, C I; Newbrun, E; Mettraux, G; Graf, H
Composition and genesis of calcium deposits in atheroma plaques.
Abstract The composition of atheromatous plaque determines its progression toward rupture or thrombosis. Although its histopathological structure has been widely studied, little attention has been paid to its structural and chemical composition and even less to its mineral component. Thirty-three atheromatous plaques were obtained by carotid thromboendarterectomy. Three types of materials were observed under polarized light microscopy: apatite crystals in the form of glomeruli (dark with plane polarized illumination and greensh with cross-polarized illumination); fibrous-like cholesterol (uncolored or grayish with plane-polarized illumination); and amorphous organic material as brownish deposits. SEM-EDX analysis showed an abundance of phosphorus and calcium in sufficient quantities to form calcium phosphates, and appreciably reduced levels of sodium. X-ray diffraction results differentiated samples into three groups: group I with predominance of hydroxyapatite-type crystals, group II with crystalline material containing an amorphous component, and group III with wholly amorphous material. The most abundant mineral in atheromatous plaque is hydroxyapatite, on which crystals of cholesterol and lipid nuclei are deposited, stratifying the plaque into layers that reflect the different stages of its formation. The difference in calcium and sodium concentrations between arteries with and without atheromata may indicate an important relationship in the pathophysiological development of calcium deposits. PMID:24134634
Lara, María Jesús; Ros, Eduardo; Sierra, Manuel; Dorronsoro, Carlos; Aguilar, José
Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque
In the last two decades, a substantial number of articles have been published to provide diagnostic solutions for patients with carotid atherosclerotic disease. These articles have resulted in a shift of opinion regarding the identification of stroke risk in patients with carotid atherosclerotic disease. In the recent past, the degree of carotid artery stenosis was the sole determinant for performing carotid intervention (carotid endarterectomy or carotid stenting) in these patients. We now know that the degree of stenosis is only one marker for future cerebrovascular events. If one wants to determine the risk of these events more accurately, other parameters must be taken into account; among these parameters are plaque composition, presence and state of the fibrous cap (FC), intraplaque haemorrhage, plaque ulceration, and plaque location. In particular, the FC is an important structure for the stability of the plaque, and its rupture is highly associated with a recent history of transient ischaemic attack or stroke. The subject of this review is imaging of the FC.
Saba, Luca, E-mail: firstname.lastname@example.com [Azienda Ospedaliero-Universitaria di Cagliari, Department of Radiology (Italy); Potters, Fons; Lugt, Aad van der [Erasmus Medical Center Rotterdam, Department of Radiology (Netherlands); Mallarini, Giorgio [Azienda Ospedaliero-Universitaria di Cagliari, Department of Radiology (Italy)
Development of Tc-99m Imaging Agents for Abeta Plaques
Development of SPECT imaging agents based on Tc-99m targeting A? plaques is useful for diagnosis of Alzheimer's disease (AD). A stilbene derivative, [11C]SB-13, showing promise in detecting senile plaques present in AD patients has been reported previously1,2. Based on the 4'-amino-stilbene core structure we have added substituted groups through which a chelating group, N2S2, was conjugated. We report herein a series of Tc-99m labeled stilbene derivative conjugated with a TcO[N2S2] core. The syntheses of stilbenes containing a N2S2 chelating ligand are achieved by a scheme shown. Lipophilic 99mTc stilbene complexes were successfully prepared and purified through HPLC. Preliminary results of in vitro labeling of brain sections from transgenic mice showed very promising plaque labeling. These 99mTc stilbene derivatives are warranted for further evaluations as potential imaging agents targeting amyloid plaques.
Zhi-Ping, Zhuang; Mei-Ping Kung; Catherihne Hou; Hank F. Kung
Gass plaques and fluorescein leakage in Susac Syndrome
IntroductionSusac Syndrome (SS) consists of the triad of encephalopathy, branch retinal artery occlusion, and hearing loss. It is an autoimmune endotheliopathy that primarily affects young women. Two funduscopic findings, Gass plaques (GP) and arteriolar wall hyperfluorescence (AWH), have recently been described and are not only useful in making the SS diagnosis but also point to the endothelium as the site
Robert A. Egan; William L. Hills; John O. Susac
Biochemical imaging of human atherosclerotic plaques with fluorescence lifetime angioscopy.
A prototype angioscopy system with fluorescence lifetime imaging microscopy (FLIM) capabilities was built and applied for biochemical imaging of human coronary atherosclerotic plaques. The FLIM angioscopy prototype consisted of a thin flexible angioscope suitable for UV-excited autofluorescence imaging, and a FLIM detection system based on a pulse sampling approach. The angioscope was composed of an imaging bundle attached to a gradient index objective lens and surrounded by a ring of illumination fibers (2 mm outer diameter, 50 microm spatial resolution). For FLIM detection based on the pulse sampling approach, a gated-intensified charge-couple device camera (200 ps temporal resolution) was used. Autofluorescence was excited with a pulsed UV laser (337 nm) and FLIM images were acquired at three emission bands (390/40 nm, 450/40 nm, 550/88 nm). The system was characterized on standard fluorophores and then used to image postmortem human coronary arteries. The FLIM angioscope allowed us to distinguish elastin-dominant plaques (peak emission at 450 nm, approximately 1.5 ns lifetimes) from collagen-dominant plaques (peak emission at 390 n, approximately 2-3 ns lifetimes) based on their intrinsic fluorescence spectral and lifetime differences. This study demonstrates the potential of FLIM angioscopy for biochemical imaging of human coronary atherosclerotic plaques. PMID:20331523
Thomas, Patrick; Pande, Paritosh; Clubb, Fred; Adame, Jessie; Jo, Javier A
Correlation between major adverse cardiac events and coronary plaque characteristics
BACKGROUND: Unstable plaque is believed to be responsible for major adverse cardiac events (MACE). OBJECTIVE: To determine whether coronary computed tomography angiography (CCTA) could be used to predict future MACE. METHODS: Patients undergoing CCTA between January 2008 and February 2010 were consecutively enrolled in the study. The hospital database was screened for patients who later developed acute ST segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI) or cardiac death. Plaque scores were calculated and analyzed using one-way ANOVA to examine the relationship between plaque scores and MACE. RESULTS: Of the 8557 patients who underwent CCTA, 1055 had hospital records available for follow-up. During follow-up, 25 patients experienced MACE including death (six patients), heart failure (two patients), STEMI (11 patients) and NSTEMI (six patients). The plaque scores were significantly increased in patients who later died, developed heart failure or experienced STEMI (P<0.05). Calcification, erosion and severe stenosis were responsible for the events (P<0.05). Mild and moderate lesions, positive remodelling, drug-eluting stent placement, occlusion and diffuse lesions were not predictive of MACE (P>0.05). CONCLUSION: Severe calcification, erosion and severe stenosis predict death, heart failure and STEMI.
He, Bin; Gai, Luyue; Gai, Jingjing; Qiao, Huaiyu; Zhang, Shuoyang; Guan, Zhiwei; Yang, Li; Chen, Yundai
Enumeration of bacteriophages using the small drop plaque assay system.
The determination of the concentration of infectious phage particles is fundamental to many protocols in phage biology, genetics, and molecular biology. Described here is a drop plaque assay, which, being simpler, faster and more efficient than either the classical overlay or direct plating methods, enhances efficiency in processing large numbers of samples. PMID:19066813
Mazzocco, Amanda; Waddell, Thomas E; Lingohr, Erika; Johnson, Roger P
T. J. Lee Presents Plaque to Vice President Dan Quayle
NASA Technical Reports Server (NTRS)
Vice President Dan Quayle holds up an inscribed plaque presented by Marshall Space Flight Center Director T. J. Lee (right) during Quayle's August 31, 1992 visit. While at Marshall, Quayle participated in a roundtable discussion with aerospace managers and addressed Center employees in Building 4755.
Basal plate plaque: a novel organising placental thrombotic process
In contrast to thrombi and haematomas at other body sites, thrombi in the placental intervillous space are not traditionally known to undergo organisation. This report presents 11 examples of a form of organising thrombotic process that develops as a plaque on the foetal aspect of the basal plate. Originally identified in the placenta of a foetus showing severe intrauterine growth
Brendan Fitzgerald; Patrick Shannon; John Kingdom; Sarah Keating
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
DETAIL VIEW OF GENERAL ELECTRIC PLAQUE INSIDE NORTHWEST CONTROL HOUSE SHOWING MANUFACTURING SPECIFICATIONS AND SWASTICA IN LOWER RIGHT CORNER - Ortona Lock, Lock No. 2, Machinery and Control Houses, Caloosahatchee River, Cross-State Canal, Okeechobee Intracoastal Waterway, Ortona, Glades County, FL
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
6. VIEW OF BRIDGE COMMEMORATIVE PLAQUE WHICH STATES '1908, J. H. CROOKS, ED. ELLIS, A. S. LELAND, COMMISSIONERS. L. E. BRELSFORD, AUDITOR. L. WEST, SURVEYOR. - B. C. GERWICK, DESIGNER. F. E. WITHCOTT, ENG. ON CONST. C. A. WARNER, CONTRACTOR.' - First Street Reinforced Concrete Bridge, Spanning Moxahala Creek at First Street (CR 7), Roseville, Muskingum County, OH
The Predominant Cultivable Flora of Carious Plaque and Carious Dentine
The quantitative recovery of bacteria from single localized sites, namely the interproximal plaque over a carious lesion and the underlying carious dentine, was undertaken. The samples were collected with minimal oxygen exposure and after dispersion and serial dilution were plated on mitis salivarius agar and various formulations of MM10 agar (a dilute trypticase, yeast extract medium). Higher total counts, Strep,
W. J. Loesche; S. A. Syed
Neutral glycolipids of atherosclerotic plaques and unaffected human aorta tissue.
The composition, structure and localization of neutral glycosphingolipids of human aorta taken from subjects who had died after myocardial infarction were studied. Individual glycosphingolipids were purified by high-performance liquid chromatography and were characterized on the basis of their chromatographic mobility, carbohydrate composition, methylation analysis and by 1H-NMR spectroscopy. The main aortic glycosphingolipids were identified as glucosylceramide, lactosylceramide, globotriaosylceramide and globotetraosylceramide. Significant differences in the neutral glycosphingolipid composition of intima and media were detected. The neutral glycosphingolipid profile of medial plaques resembled that of unaffected media; however, significant differences were detected between intimal plaques and unaffected intima. Whereas the latter contained trihexosylceramide and globoside as the only neutral glycolipids, the intimal plaque glycolipids consisted mainly of glucosylceramide and also contained appreciable amounts of lactosylceramide which were completely absent in the unaffected intima. In comparison to intimal plaques, unaffected intima is characterized by a much higher content of cerebrosides terminating by beta-galactosyl residues which are known to interact with growth factors and other external stimuli. It thus seems possible that the proliferative activity of smooth muscle cells in atherosclerotic diseases is to some extent associated with their neutral glycolipid profile. PMID:2707259
Prokazova, N V; Mukhin, D N; Orekhov, A N; Gladkaya, E M; Vasilevskaya, V V; Mikhailenko, I A; Sadovskaya, V L; Bushuev, V N; Bergelson, L D
Erosion of psoriatic plaques: An early sign of methotrexate toxicity
Methotrexate is an effective but potentially toxic treatment for psoriasis. Well-known signs of methotrexate toxicity include bone marrow suppression and oral and gastrointestinal ulceration. Painful erosion of psoriatic plaques is a less common sign of methotrexate toxicity that may precede evidence of bone marrow suppression. We describe two patients in whom painful erosions of their psoriasis developed as the presenting
Hannah P. Pearce; Barbara Braunstein Wilson
Tangles and plaques in nondemented aging and ?preclinical? Alzheimer's disease
The distribution and density of neurofibrillary tangles and amyloid plaques was studied in a unique series of cases whose premortem cognitive status had been assessed with the Clinical Dementia Rating (CDR), including 39 nondemented cases (CDR 5 0; age, 51- 88 years), 15 very mildly demented cases (CDR 5 0.5), and 8 severely demented (CDR 5 3) cases. The initial
Joseph L. Price; John C. Morris
Amyloid Plaque Core Protein in Alzheimer Disease and Down Syndrome
We have purified and characterized the cerebral amyloid protein that forms the plaque core in Alzheimer disease and in aged individuals with Down syndrome. The protein consists of multimeric aggregates of a polypeptide of about 40 residues (4 kDa). The amino acid composition, molecular mass, and NH2-terminal sequence of this amyloid protein are almost identical to those described for the
Colin L. Masters; Gail Simms; Nicola A. Weinman; Gerd Multhaup; Brian L. McDonald; Konrad Beyreuther
Endothelin1 is increased overlying atherosclerotic plaques in human arteries
The distribution of Endothelin-1 (ET-1), a potent vasoactive peptide, within endothelium of human atherosclerotic arteries was examined using a novel en face immunohistochemical technique. The vast majority of endothelial cells were immunoreactive for ET-1. Staining intensity was increased in areas overlying atherosclerotic plaques, calcified media, fatty streaks and about flow dividers, compared with adjacent regions. Multinucleated 'giant' endothelial cells were
Gregory T. Jones; André M. van Rij; Clive Solomon; Ian A. Thomson; Stephen G. K. Packer
Enzymatic Prevention and Control of Dental Plaque Formation.
National Technical Information Service (NTIS)
The solubilization of human plaque and materia alba was measured in vitro using 78 different enzyme preparations from 22 different companies or investigators. Enzymes were normally incubated at 17 micrograms/ml with about 700 micrograms/ml of brushings (d...
D. L. Williams S. Turesky J. H. Kerrigan
Effects of Fluoride-Supplemented Sucrose on Experimental Dental Caries and Dental Plaque PH
Sucrose, 5% and 10% (w\\/v), supplemented with between 0 and 5 ppm fluoride (F), was tested for its influence in vitro on plaque-induced experimental in vitro enamel caries and plaque pH. Plaque growth on bovine enamel was initiated from saliva inocula and sustained in a multiple plaque growth system for up to 31 days by means of a basal medium
T. W. Cutress; C. H. Sissons; E. I. F. Pearce; L. Wong; K. Anderssén; B. Angmar-Mĺnsson
Identification of Seven Treponema Species in Health and Disease-Associated Dental Plaque by Nested PCR
Species-specific nested PCR was used to detect Treponema amylovorum, Treponema denticola, Treponema maltophilum, Treponema medium, Treponema pectinovorum, Treponema socranskii, and Treponema vincentii in dental plaque. Subjects with periodontitis harbored all species, but T. pectinovorum and T. vincentii were not found in plaque from disease-free subjects. Plaque treponemas are associated with periodontal diseases (6), but detection of individual species has been
Electron Microscopic Study of the Effect of Water Jet Lavage Devices on Dental Plaque
The maxillary posterior teeth of nine rhesus monkeys were treated with a pulsating water lavage instrument at 70 psi (high setting). Electron microscopic studies of pre- and post-lavage plaque samples showed that water jet devices as used in this experiment either removed the plaque completely or caused irreversible damage to the microbial forms in the plaque matrix.
John M. Brady; Walter A. Gray; Surindar N. Bhaskar
Methods in Atherosclerotic Plaque Characterization Using Intravascular Ultrasound Images and Backscattered Signals
\\u000a We will review existing supervised as well as unsupervised image- and spectrumderived algorithms in the context of atherosclerotic\\u000a plaque characterization and detection of vulnerable plaques. We will further elaborate more on challenges involved in characterization\\u000a of plaques from tissue preparation, data collection, and registration toward classification.
Amin Katouzian; Stéphane G. Carlier; Andrew F. Laine
Evidence for Increased Collagenolysis by Interstitial Collagenases-1 and -3 in Vulnerable Human Atheromatous Plaques
Background—Several recent studies attempted to classify plaques as those prone to cause clinical manifestations (vulnerable, atheromatous plaques) or those less frequently associated with acute thrombotic complication (stable, fibrous plaques). Defining the cellular and molecular mechanisms that underlie these morphological features remains a challenge. Because interstitial forms of collagen determine the biomechanical strength of the atherosclerotic lesion, this study investigated expression
Galina K. Sukhova; Uwe Schonbeck; Elena Rabkin; Frederick J. Schoen; A. Robin Poole; R. Clark Billinghurst; Peter Libby
Visualization of coronary atherosclerotic plaques in patients using different imaging modalities
Different imaging modalities have been developed over the last several years in order to better characterize the atherosclerotic plaque and attempt to predict those in peril of complication. Specific information such as variations in temperature, plaque stiffness and calcification level is currently being researched as well as biological and chemical markers. Since vulnerable plaques cannot be identified by stress testing
Mohammad Karimi Moridani
Intravascular Ultrasound Elastography: A Clinician's Tool for Assessing Vulnerability and Material Composition of Plaques
The material composition and morphology of the atherosclerotic plaque components are considered to be more important determinants of acute coronary ischemic syndromes than the degree of stenosis. When a vulnerable plaque ruptures it causes an acute thrombotic reaction. Rupture prone plaques contain a large lipid pool covered by a thin fibrous cap. The stress in these caps increases with decreasing
R. A. Baldewsing; J. A. Schaar; C. L. de Korte; F. Mastik; P. W. Serruys
Controlling the angiogenic switch in developing atherosclerotic plaques: Possible targets for therapeutic intervention
Plaque angiogenesis may have an important role in the development of atherosclerosis. Vasa vasorum angiogenesis and medial infiltration provides nutrients to the developing and expanding intima and therefore, may prevent cellular death and contribute to plaque growth and stabilization in early lesions. However in more advanced plaques, inflammatory cell infiltration, and concomitant production of numerous pro-angiogenic cytokines may be responsible
Mark Slevin; Jerzy Krupinski; Lina Badimon
The Impact of Calcification on the Biomechanical Stability of Atherosclerotic Plaques
Background—Increased biomechanical stresses in the fibrous cap of atherosclerotic plaques contribute to plaque rupture and, consequently, to thrombosis and myocardial infarction. Thin fibrous caps and large lipid pools are important determinants of increased plaque stresses. Although coronary calcification is associated with worse cardiovascular prognosis, the relationship between atheroma calcification and stresses is incompletely described. Methods and Results—To test the hypothesis
Hayden Huang; Renu Virmani; Hesham Younis; Allen P. Burke; Roger D. Kamm; Richard T. Lee
Pleural plaques and exposure to mineral fibres in a male urban necropsy population
OBJECTIVES--The study aimed to evaluate the risk of pleural plaques according to the degree of past exposure to asbestos, type of amphibole asbestos, and smoking, as well as to estimate the aetiologic fraction of asbestos as a cause of plaques among urban men. METHODS--The occurrence and extent of pleural plaques were recorded at necropsies of 288 urban men aged 33
A Karjalainen; P J Karhunen; K Lalu; A Penttilä; E Vanhala; P Kyyrönen; A Tossavainen
Development of Positron Emission Tomography ?-Amyloid Plaque Imaging Agents
For 100 years, ?-amyloid (A?) plaques and neurofibrillary tangles (NFTs) have been recognized as the neuropathological hallmarks of Alzheimer's disease (AD), and their presence or absence could only be assessed postmortem using stains and dyes that identified these microscopic structures. Approximately 10 years ago, the first successful A? plaque–specific positron emission tomography (PET) imaging study was conducted in a living human subject clinically diagnosed with probable AD using the 11C-labeled radiopharmaceutical Pittsburgh Compound B (PiB). Laboratory studies and preclinical evaluations to design PiB began a decade earlier than the first human PiB PET study and involved chemical modifications of different well-known dyes that bound specifically to the extended ?-pleated sheets that comprise the fibrils of amyloid proteins such as A? plaques, NFTs, ?-synuclein deposits, and prions. These preclinical studies were conducted in our laboratories at the University of Pittsburgh, starting with Congo red derivatives, followed by Chrysamine G derivatives, followed by X-series compounds, and finally with neutral derivatives of thioflavin-T. The in vitro and in vivo evaluations of the different derivatives as candidate PET radioligands for imaging A? plaques and neurofibrillary tangles in human brain are described in this review, along with the specific evaluation criteria by which the candidate radioligands were judged. Out of these studies came PiB, a PET radioligand that binds selectively and with high affinity to only fibrillar forms of A?. PiB has been used in many different human research protocols throughout the world and has demonstrated the usefulness of assessing the A? plaque status of subjects many years before the clinical diagnosis of probable AD. Recently, longer-lived 18F-radiolabeled A?-selective radiopharmaceuticals have been developed. It is likely that the full clinical impact of these imaging agents will be realized by identifying presymptomatic subjects who would benefit from early drug treatments with future disease-modifying AD therapeutics.
Mathis, Chester A.; Mason, N. Scott; Lopresti, Brian J.; Klunk, William E.
Plaque-inhibiting effect of bioadhesive mucosal tablets containing chlorhexidine in a 4-day plaque regrowth model
Background and aim. Compliance in the use of daily oral antiseptics can probably be enhanced by prescribing easily-applied bioadhesive tablets which slowly release chlorhexidine (CHX). This could also be of use in patients with difficulties in rinsing or performing mechanical plaque control. The aim of the present study was to evaluate the capacity of bioadhesive tablets containing either 30 mg
P. Coessens; F. Herrebout; De J. Boever; J. Voorspoels; J. Remon
Bacteria present in carotid arterial plaques are found as biofilm deposits which may contribute to enhanced risk of plaque rupture.
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. Importance: 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, and we demonstrate that one species we have identified in plaques can be stimulated in vitro to undergo a biofilm dispersion response when challenged with physiologically relevant levels of norepinephrine in the presence of transferrin. Biofilm dispersion is characterized by the release of bacterial enzymes into the surroundings of biofilm microcolonies, allowing bacteria to escape the biofilm matrix. We believe these enzymes may have the potential to damage surrounding tissues and facilitate plaque rupture if norepinephrine is able to stimulate biofilm dispersion in vivo. This research, therefore, suggests a potential mechanistic link between hormonal state and the potential for heart attack and stroke. PMID:24917599
Lanter, Bernard B; Sauer, Karin; Davies, David G
Echo-Lucency of Computerized Ultrasound Images of Carotid Atherosclerotic Plaques Are Associated With Increased Levels of Triglyceride-Rich Lipoproteins as Well as Increased Plaque Lipid Content
Background—Echo-lucency of carotid atherosclerotic plaques on computerized ultrasound B-mode images has been associated with a high incidence of brain infarcts as evaluated on CT scans. We tested the hypotheses that triglyceride-rich lipoproteins in the fasting and postprandial state predict carotid plaque echo-lucency and that echo-lucency predicts a high plaque lipid content. Methods and Results—The study included 137 patients with neurological
Marie-Louise M. Grřnholdt; Břrge G. Nordestgaard; Britt M. Wiebe; Jens E. Wilhjelm; Henrik Sillesen
Observations of psoriasis in the absence of therapeutic intervention identifies two unappreciated morphologic variants, thin-plaque and thick-plaque psoriasis, and their associated phenotypes.
Psoriatic plaque thickness is a clinical measure of psoriasis severity. We have observed that patients tend to revert to a baseline thickness of psoriatic plaques when in an untreated state, and hypothesized that other features of psoriasis could associate with this trait. Data prospectively collected on 500 participants in the Utah Psoriasis Initiative were used for the study. In response to a question assessing plaque thickness when disease was at its worst, 144 (28.8%) reported thick plaques, 123 (24.6%) reported thin plaques, and 233 (46.6%) reported intermediate thickness. For patients with "worst-ever" disease at enrollment (n=122), there was significant correlation of thickness between assessment by the patient and the physician (r=0.448, P-value 0.01). Thick plaques associated with male gender, increased body mass index, nail disease, psoriatic arthritis, larger plaques, more body sites, and greater total body surface area affected. Thin plaques associated with eczema, guttate psoriasis, and skin cancer. We suggest that this is preliminary evidence that plaque thickness is an easily measured trait that associates with other clinical features of psoriasis, and that stratification on this phenotype may be useful in further defining the genetic basis of this disease. PMID:16858419
Christensen, Tanya E; Callis, Kristina P; Papenfuss, Jason; Hoffman, Matthew S; Hansen, Christopher B; Wong, Bob; Panko, Jacqueline M; Krueger, Gerald G
In vitro antiplaque activity of octenidine dihydrochloride (WIN 41464-2) against preformed plaques of selected oral plaque-forming microorganisms.
The antibacterial activity of octenidine dihydrochloride (WIN 41464-2) against intact preformed in vitro plaques of four indigenous oral plaque-forming microorganisms, Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii, was studied. Both absolute (plaque bactericidal index) and relative (chlorhexidine coefficient) indices of antiplaque efficacy were established. Octenidine dihydrochloride compared favorably with chlorhexidine digluconate with respect to overall antiplaque potency in this in vitro plaque bactericidal model. These data indicate that prudent selection of treatment concentration and duration and frequency of exposure should provide an effective means to aid in controlling dental caries and Actinomyces-associated disease in vivo.
Slee, A M; O'Connor, J R
Plaques of Alzheimer's disease originate from cysts of Borrelia burgdorferi, the Lyme disease spirochete.
Here is hypothesized a truly revolutionary notion that rounded cystic forms of Borrelia burgdorferi are the root cause of the rounded structures called plaques in the Alzheimer brain. Rounded "plaques' in high density in brain tissue are emblematic of Alzheimer's disease (AD). Plaques may be conceptualized as rounded "pock mark-like" areas of brain tissue injury. In this century, in brain tissue of AD, plaques are Amyloid Plaques according to the most up to date textbooks. In the last century, however, Dr. Alois Alzheimer did not require amyloid as the pathogenesis for either the disease or for the origin of its plaques. Surely, amyloid is an event in AD, but it may not be the primal cause of AD. Indeed in plaques, amyloid is regularly represented by the "congophilic core" structure which is so named because the waxy amyloid material binds the congo red stain and is congophilic. However an accepted subset of plaques in AD is devoid of a congophilic amyloid core region (these plaques "cotton wool" type plaques, lack a central congophilic core structure). Furthermore, there is "plaque diversity" in Alzheimer's; small, medium and large plaques parallel variable cystic diameters for Borrelia burgdorferi. Perturbations of AD plaque structure (i.e. young plaques devoid of a central core and older plaques with or without a central core structure) offer room for an alternate pathway for explanation of ontogeny of the plaque structures. If amyloid is not required to initiate all of the possible plaques in Alzheimer's, is it possible that amyloid just a by product of a more fundamental primal path to dementia? If a byproduct status is assigned to amyloid in the realm of plaque formation, then is amyloid also an epiphenomenon rather than a primary pathogenesis for Alzheimer's disease. In the "anatomy is destiny" model, cysts of borrelia are always round. Why then not accept roundness as a fundamental "structure determines function" argument for the answer to the mystery of why Alzheimer plaques are always round? Parataxis causality, a concept borrowed from philosophy, is the error that comes from linking two events, which occur contemporaneously or in close proximity to one another with a cause and effect relationship. Parataxis tells us that what appears to be cause and effect in the couplet "amyloid plaque" merely by a proximity relationship may be "spurious causality" which is a cognitive dead end. PMID:16675154
MacDonald, Alan B
Coronary Plaque Type and Burden By Computed Tomography Angiography Without Association to C-Reactive Protein
Background: Contrast-enhanced computed tomography angiography (CTA) of the coronaries allows identification of plaques. Limited data exists on the relationship between C-reactive protein (CRP) and the plaque type or plaque burden detected by CTA. Aims: We studied relationship between CRP and coronary atherosclerosis. Materials and Methods: 92 patients without history of coronary disease underwent coronary CTA for chest pain. Coronary arteries were evaluated with each detected plaque labeled as calcified, noncalcified or mixed. Logarithmic transformation was done on CRP values for statistical analysis. Results: 1380 coronary segments were evaluated. The average age was 57 years (SE 1.0) and basal metabolic index (BMI) 28.9 kg/m2 (SE 0.5). Median CRP level was 2.75 mg/L (range 0.17-16.98). No association was found between CRP quartiles and plaque type. In stepwise multivariate analysis, only diabetes was associated with noncalcified plaque (P < 0.001). When calcified and mixed plaques were added to the model, age (P < 0.001), diabetes (P < 0.02), and statin use (P < 0.05) were associated with an increased number of plaques per subject. No association was found between log-CRP for any type of plaque. Conclusion: There was no association between CRP and plaque type by CTA. Lack of association is likely due to limited spatial resolution and underestimation of noncalcified plaque burden by CTA.
Navaravong, Leenhapong; Steenson, Carol; Sigurdsson, Gardar
Dynamic variations in the ultrasound greyscale median of carotid artery plaques.
BACKGROUND: Several studies have found that the ultrasound greyscale median (GSM) of carotid artery plaques may be useful for predicting the risk of cerebrovascular events. However, measurements of GSM are typically performed on still ultrasound images ignoring any variations that may be observed on a frame-by-frame basis. The aim of this study was to establish the existence and investigate the nature and extent of these variations. METHODS: Employing a novel method that enabled plaque boundaries to be tracked semi-automatically, variations in the plaque GSM and observed cross-sectional area were measured for 27 carotid artery plaques (19 consecutive patients, stenosis range 10%-80%) over image sequences of up to 10 seconds in length acquired with a mean frame rate of 32 frames per second. RESULTS: Our results showed a mean inter-frame coefficient of variation (CV) of 5.2% (s.d. 2.5%) for GSM and 4.2% (s.d. 2.9%) for the plaque area. Thirteen of the 27 plaques (48%) exhibited CV in GSM greater than 5% whereas only 6 plaques (22%) had CV in plaque area of greater than 5%. There was no significant correlation between the CV of GSM and plaque area. CONCLUSIONS: Inter-frame variations in the plaque GSM such as those found in this study have implications on the reproducibility of GSM measurements and their clinical utility. Studies assessing the GSM of carotid artery plaques should consider these variations. PMID:23767988
Kanber, Baris; Hartshorne, Timothy C; Horsfield, Mark A; Naylor, Andrew R; Robinson, Thompson G; Ramnarine, Kumar V
A double layer plaque assay using spread plate technique for enumeration of bacteriophage MS2.
Bacteriophage MS2 is used widely as a model organism to estimate pathogenic virus survival in various environments, and is usually quantified by plaque assay. Although current plaque assays work well in enumeration of MS2 in environmental samples, quantification of MS2 calls for better visibility and higher consistency. In an attempt to improve the visibility and consistency of the current plaque assay, spread plate technique was introduced, instead of the pour plate technique used commonly in existing methods. Other parameters that influence the outcome of the plaque assay were also compared. Using spread plate technique resulted in an increase of plaque size by approximately 50% and contributed to a better visibility. Addition of supplements (glucose, CaCl2 and thiamine); reduction of agar thickness and hardness, also contributed to enhanced plaque visibility and increased plaque count. Among all the conditions tested, a supplemented thin bottom agar (10ml 1% agar) and a supplemented thin top agar (10ml 0.45% agar) with spread plate technique gave the maximum countable plaques with a minimum standard deviation. When compared to other methods, it produced significantly higher plaque count and lower variation. The optimized plaque assay significantly improved visibility and consistency of the existing plaque assay methods and could be used in quantification of MS2. PMID:24211298
Cormier, Jiemin; Janes, Marlene
Magnetic resonance imaging of vulnerable atherosclerotic plaques: current imaging strategies and molecular imaging probes.
The vulnerability or destabilization of atherosclerotic plaques has been directly linked to plaque composition. Imaging modalities, such as magnetic resonance (MR) imaging, that allow for evaluation of plaque composition at a cellular and molecular level, could further improve the detection of vulnerable plaque and may allow for monitoring the efficacy of antiatherosclerotic therapies. In this review we focus on MR imaging strategies for the detection and evaluation of atherosclerotic plaques and their composition. We highlight recent advancements in the development of MR pulse sequences, computer image analysis, and the use of commercially available MR contrast agents, such as gadopentic acid (Gd-DTPA), for plaque characterization. We also discuss molecular imaging strategies that are currently being used to design specific imaging probes targeted to biochemical and cellular markers of atherosclerotic plaque vulnerability. PMID:17729343
Briley-Saebo, Karen C; Mulder, Willem J M; Mani, Venkatesh; Hyafil, Fabien; Amirbekian, Vardan; Aguinaldo, Juan Gilberto S; Fisher, Edward A; Fayad, Zahi A
Ultrasound determination of the relationship of radioactive plaques to the base of choroidal melanomas
There is an assumption that radioactive plaques placed at surgery are, and will remain, in proper relationship to the base of the tumor. The plaque dose is calculated based on this assumption. In fact, factors such as loose sutures, improper diameter estimations, pressure from adjacent rectus muscles, and intervening tissue (oblique muscles) can compromise this relationship. Ultrasound provides a practical method of imaging the tumor and plaque simultaneously. The authors have used postoperative ultrasound to monitor the accuracy of iodine-125 plaque placement in nine cases. Detection of eccentrically placed and malpositioned plaques provides valuable insight which can be used to refine surgical technique. Detection of plaque tilting by oblique muscles can serve as a basis for recalculating dosage. The relationship of plaque margins to vital ocular structures such as the optic nerve can also be determined by ultrasound.
Pavlin, C.J.; Japp, B.; Simpson, E.R.; McGowan, H.D.; Fitzpatrick, P.J.
Helicobacter pylori in dental plaque and gastric mucosa: correlation revisited.
Helicobacter pylori (H. pylori) related gastric infection is highly prevalent in developing countries. Prevalence of bacterium in dental plaque from these regions is also reported to be high, but association between simultaneous colonization of H. pylori in both these sites has not been established yet. Aim of this paper is to review possible association between simultaneous oral and gastric H. pylori colonization in dyspeptic patients. Pertinent literature was reviewed and all available evidence collected from Medline and PakMedinet. Studies conducted in the developing world show conflicting results. Some report a positive relation between oral and gastric H. pylori colonization while others deny any association. This may be due to the population sampled or methodology applied. Further studies are recommended to confirm the association between concurrent presence of H. pylori in dental plaque and gastric mucosa of dyspeptic patients using sensitive and specific tests for detection of bacterium in oral samples. PMID:18988394
Chaudhry, Saima; Iqbal, Hafiz Aamer; Khan, Ayyaz Ali; Izhar, Mateen; Butt, Arshad Kamal; Akhter, M Waheed; Izhar, Faisal; Mirza, Kamran Masood
Oral care and pulmonary infection - the importance of plaque scoring
Improving the quality of oral hygiene is recognised as an important counter measure for reducing the incidence of ventilator-associated pneumonia amongst critically ill patients. Toothbrushing physically disrupts the dental plaque that acts as a reservoir for pulmonary infection and therefore has the potential to reduce the incidence of ventilator-associated pneumonia. Gu and colleagues performed a systematic review and meta-analysis of oral hygiene with and without a toothbrush and found no difference in the incidence of pneumonia in mechanically ventilated patients. The diagnosis of ventilator-associated pneumonia is prone to bias and future studies of oral care interventions should focus on measures of oral cleanliness such as plaque and gingival scores. Once the optimal strategy for oral hygiene is defined in the critically ill, larger studies focussing on ventilator-associated pneumonia or mortality can be conducted.
The prevention and regression of atherosclerotic plaques: emerging treatments
Occlusive vascular diseases, such as sudden coronary syndromes, stroke, and peripheral arterial disease, are a huge burden on the health care systems of developed and developing countries. Tremendous advances have been made over the last few decades in the diagnosis and treatment of atherosclerotic diseases. Intravascular ultrasound has been able to provide detailed information of plaque anatomy and has been used in several studies to assess outcomes. The presence of atherosclerosis disrupts the normal protective mechanism provided by the endothelium and this mechanism has been implicated in the pathophysiology of coronary artery disease and stroke. Efforts are being put into the prevention of atherosclerosis, which has been shown to begin in childhood. This paper reviews the pathophysiology of atherosclerosis and discusses the current options available for the prevention and reversal of plaque formation.
Kalanuria, Atul Ashok; Nyquist, Paul; Ling, Geoffrey
Definition of human rotavirus serotypes by plaque reduction assay.
Twenty different human rotavirus reassortants were characterized serologically by a plaque reduction assay as belonging to one of three distinct serotypes. Fourteen were similar if not identical to our prototype Wa strain; two were like the prototype DS-1 strain, and four belonged to a third serotype for which a prototype has not yet been selected. Hyperimmune sera raised against the three serotypes were required to distinguish among them, since postinfection sera had lower titers and were more cross-reactive than hyperimmune sera. These results confirmed the ability of a qualitative cytopathic neutralization test to predict correctly the Wa or DS-1 serotype. A strain of rhesus rotavirus (MMU 18006) was identified as belonging to the newly defined third serotype. Finally, an attempt was made to correlate previously published serotype analysis by neutralization of fluorescent cell-forming units with the results determined by the plaque reduction neutralization assay.
Wyatt, R G; Greenberg, H B; James, W D; Pittman, A L; Kalica, A R; Flores, J; Chanock, R M; Kapikian, A Z
Intravascular photoacoustic imaging of gold nanorod-labeled atherosclerotic plaques
NASA Astrophysics Data System (ADS)
Combined intravascular photoacoustic (IVPA) and intravascular ultrasound (IVUS) imaging has been previously established as a viable means for imaging atherosclerotic plaques using both endogenous and exogenous contrast. In this study, IVUS/IVPA imaging of an atherosclerotic rabbit aorta following injection of gold nanorods (AuNR) with peak absorbance within the tissue optical window was performed. Ex-vivo imaging results revealed high photoacoustic signal from localized AuNR. Corresponding histological cross-sections and digital photographs of the artery lumen confirmed the presence of AuNR preferentially located at atherosclerotic regions and in agreement with IVPA signal. Furthermore, an integrated IVUS/IVPA imaging catheter was used to image the AuNR in the presence of luminal blood. The results suggest that AuNR allow for IVPA imaging of exogenously labeled atherosclerotic plaques with a comparatively low background signal and without the need for arterial flushing.
Yeager, Doug; Karpiouk, Andrei; Wang, Bo; Amirian, James; Sokolov, Konstantin; Smalling, Richard; Emelianov, Stanislav
MRI Plaque Imaging Detects Carotid Plaques with a High Risk for Future Cerebrovascular Events in Asymptomatic Patients
Purpose The aim of this study was to investigate prospectively whether MRI plaque imaging can identify patients with asymptomatic carotid artery stenosis who have an increased risk for future cerebral events. MRI plaque imaging allows categorization of carotid stenosis into different lesion types (I–VIII). Within these lesion types, lesion types IV–V and VI are regarded as rupture-prone plaques, whereas the other lesion types represent stable ones. Methods Eighty-three consecutive patients (45 male (54.2%); age 54–88 years (mean 73.2 years)) presenting with an asymptomatic carotid stenosis of 50–99% according to ECST-criteria were recruited. Patients were imaged with a 1.5-T scanner. T1-, T2-, time-of-flight-, and proton-density weighted studies were performed. The carotid plaques were classified as lesion type I–VIII. Clinical endpoints were ischemic stroke, TIA or amaurosis fugax. Survival analysis and log rank test were used to ascertain statistical significance. Results Six out of 83 patients (7.2%) were excluded: 4 patients had insufficient MR image quality; 1 patient was lost-to-follow-up; 1 patient died shortly after the baseline MRI plaque imaging. The following results were obtained by analyzing the remaining 77 patients. The mean time of follow-up was 41.1 months. During follow-up, n?=?9 (11.7%) ipsilateral ischemic cerebrovascular events occurred. Only patients presenting with the high-risk lesion types IV–V and VI developed an ipsilateral cerebrovascular event versus none of the patients presenting with the stable lesion types III, VII, and VIII (n?=?9 (11.7%) vs. n?=?0 (0%) during follow-up). Event-free survival was higher among patients with the MRI-defined stable lesion types (III, VII, and VIII) than in patients with the high-risk lesion types (IV–V and VI) (log rank test P<0.0001). Conclusions MRI plaque imaging has the potential to identify patients with asymptomatic carotid stenosis who are particularly at risk of developing future cerebral ischemia. MRI could improve selection criteria for invasive therapy in the future.
Esposito-Bauer, Lorena; Saam, Tobias; Ghodrati, Iman; Pelisek, Jaroslav; Heider, Peter; Bauer, Matthias; Wolf, Petra; Bockelbrink, Angelina; Feurer, Regina; Sepp, Dominik; Winkler, Claudia; Zepper, Peter; Boeckh-Behrens, Tobias; Riemenschneider, Matthias; Hemmer, Bernhard; Poppert, Holger
The Dental Plaque Microbiome in Health and Disease
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.
Peterson, Scott N.; Snesrud, Erik; Liu, Jia; Ong, Ana C.; Kilian, Mogens; Schork, Nicholas J.; Bretz, Walter
Copper, iron and zinc in Alzheimer's disease senile plaques
Concentrations of copper (Cu), iron (Fe) and zinc (Zn) were measured in the rims and cores of senile plaques (SP) and in the neuropil of the amygdala of nine Alzheimer's disease (AD) patients and in the neuropil of the amygdala of five neurologically normal control subjects using micro particle-induced X-ray emission (micro-PIXE). Comparison of SP rim and core values revealed
M. A Lovell; J. D Robertson; W. J Teesdale; J. L Campbell; W. R Markesbery
Simvastatin Attenuates Plaque Inflammation Evaluation by Fluorodeoxyglucose Positron Emission Tomography
METHODS Forty-three consecutive subjects, who underwent 18FDG-PET for cancer screening and had 18 FDG uptakes in the thoracic aorta and\\/or the carotid arteries, were randomized to either statin group receiving simvastatin (n 21) or diet group receiving dietary management only (n 22). The maximum standardized uptake values (SUVs) were measured in individual plaques, and were averaged for analysis of the
Nobuhiro Tahara; Hisashi Kai; Masatoshi Ishibashi; Hiroyuki Nakaura; Hayato Kaida; Kenkichi Baba; Naofumi Hayabuchi; Tsutomu Imaizumi
A rotational ablation tool for calcified atherosclerotic plaque removal.
Atherosclerosis is a major cardiovascular disease involving accumulations of lipids, white blood cells, and other materials on the inside of artery walls. Since the calcification found in the advanced stage of atherosclerosis dramatically enhances the mechanical properties of the plaque, restoring the original lumen of the artery remains a challenge. High-speed rotational atherectomy, when performed with an ablating grinder to remove the plaque, produces much better results in the treatment of calcified plaque compared to other methods. However, the high-speed rotation of the Rotablator commercial rotational atherectomy device produces microcavitation, which should be avoided because of the serious complications it can cause. This research involves the development of a high-speed rotational ablation tool that does not generate microcavitation. It relies on surface modification to achieve the required surface roughness. The surface roughness of the tool for differential cutting was designed based on lubrication theory, and the surface of the tool was modified using Nd:YAG laser beam engraving. Electron microscope images and profiles indicated that the engraved surface of the tool had approximately 1 ?m of root mean square surface roughness. The ablation experiment was performed on hydroxyapatite/polylactide composite with an elastic modulus similar to that of calcified plaque. In addition, differential cutting was verified on silicone rubber with an elastic modulus similar to that of a normal artery. The tool performance and reliability were evaluated by measuring the ablation force exerted, the size of the debris generated during ablation, and through visual inspection of the silicone rubber surface. PMID:21792606
Kim, Min-Hyeng; Kim, Hyung-Jung; Kim, Nicholas N; Yoon, Hae-Sung; Ahn, Sung-Hoon
Optical detection of structural changes in human carotid atherosclerotic plaque
NASA Astrophysics Data System (ADS)
Background: Arterial bifurcations are commonly the sites of developing atherosclerotic plaque that lead to arterial occlusions and plaque rupture (myocardial infarctions and strokes). Laser induced fluorescence (LIF) spectroscopy provides an effective nondestructive method supplying spectral information on extracellular matrix (ECM) protein composition, specifically collagen and elastin. Purpose: To investigate regional differences in the ECM proteins -- collagen I, III and elastin in unstable plaque by analyzing data from laser-induced fluorescence spectroscopy of human carotid endarterectomy specimens. Methods: Gels of ECM protein extracts (elastin, collagen types I & III) were measured as reference spectra and internal thoracic artery segments (extra tissue from bypass surgery) were used as tissue controls. Arterial segments and the endarterectomy specimens (n=21) were cut into 5mm cross-sectional rings. Ten fluorescence spectra per sampling area were then recorded at 5 sites per ring with argon laser excitation (357nm) with a penetration depth of 200 ?m. Spectra were normalized to maximum intensity and analyzed using multiple regression analysis. Tissue rings were fixed in formalin (within 3 hours of surgery), sectioned and stained with H&E or Movat's Pentachrome for histological analysis. Spectroscopy data were correlated with immunohistology (staining for elastin, collagen types I, III and IV). Results: Quantitative fluorescence for the thoracic arteries revealed a dominant elastin component on the luminal side -- confirmed with immunohistology and known artery structure. Carotid endarterectomy specimens by comparison had a significant decrease in elastin signature and increased collagen type I and III. Arterial spectra were markedly different between the thoracic and carotid specimens. There was also a significant elevation (p<0.05) of collagen type I distal to the bifurcation compared to proximal tissue in the carotid specimens. Conclusion: Fluorescence spectroscopy is an effective method for evaluating ECM (collagen and elastin) associated with vascular remodeling despite the considerable variability in the plaque structure. Consistent regional differences were detected in the carotid specimens.
Korol, R. M.; Canham, P. B.; Finlay, H. M.; Hammond, R. R.; Quantz, M.; Ferguson, G. G.; Liu, L. Y.; Lucas, A. R.
Murine atherosclerotic plaque imaging with the USPIO Ferumoxtran-10.
In this study we intended to image plaque inflammation in a murine model of atherosclerosis with MRI and Ferumoxtran-10 (Sinerem, Guerbet, France). 8 apoE-/- mice were injected 500 micromol Fe/kg or 1000 micromol Fe/kg Ferumoxtran-10. 2 apoE-/- mice were injected NaCl. After a post-contrast time of 24 to 336 hours the mice were scarificed and the aortas were imaged ex vivo. All measurements were performed on a 17.6 Tesla Bruker AVANCE 750WB MR scanner (Bruker, Germany). Spin-echo sequences and gradient-echo sequences with variable TE were performed and T2* maps were generated. Prussian-blue and hematoxilin-eosin histology were obtained afterwards and iron-uptake was quantified by counting iron positive areas. 2 apoE-/- mice were imaged in vivo before and 48 hours after 1000 micromol Fe/kg. Atheroma iron uptake was not elevated after 24 hours compared to controls. 48 hours after 1000 micromol Fe/kg but not 500 micromol Fe/kg histology revealed a 1.3- fold increase in plaque iron content compared to NaCl injected mice. Normalized T2*-times decreased from 0.86+/-0.02 in controls to 0.66+/-0.15 after a dose of 500 micromol Fe/ml and 0.59+/-0.14 in mice injected with 1000 micromol Fe/Kg (p=0.038). These results translated into a mean of 122% increase in CNR, as measured by in vivo MRI. We have demonstrated that Ferumoxtran-10 is taken up by atherosclerotic plaques in untreated apoE-/- mice and this alters plaque signal properties. PMID:19273218
Klug, Gert; Kampf, Thomas; Ziener, Christan; Parczyk, Marco; Bauer, Elizabeth; Herold, Volker; Rommel, Eberhard; Jakob, Peter Michael; Bauer, Wolfgang Rudolf
Sequencing viral genomes from a single isolated plaque
Background Whole genome sequencing of viruses and bacteriophages is often hindered because of the need for large quantities of genomic material. A method is described that combines single plaque sequencing with an optimization of Sequence Independent Single Primer Amplification (SISPA). This method can be used for de novo whole genome next-generation sequencing of any cultivable virus without the need for large-scale production of viral stocks or viral purification using centrifugal techniques. Methods A single viral plaque of a variant of the 2009 pandemic H1N1 human Influenza A virus was isolated and amplified using the optimized SISPA protocol. The sensitivity of the SISPA protocol presented here was tested with bacteriophage F_HA0480sp/Pa1651 DNA. The amplified products were sequenced with 454 and Illumina HiSeq platforms. Mapping and de novo assemblies were performed to analyze the quality of data produced from this optimized method. Results Analysis of the sequence data demonstrated that from a single viral plaque of Influenza A, a mapping assembly with 3590-fold average coverage representing 100% of the genome could be produced. The de novo assembled data produced contigs with 30-fold average sequence coverage, representing 96.5% of the genome. Using only 10 pg of starting DNA from bacteriophage F_HA0480sp/Pa1651 in the SISPA protocol resulted in sequencing data that gave a mapping assembly with 3488-fold average sequence coverage, representing 99.9% of the reference and a de novo assembly with 45-fold average sequence coverage, representing 98.1% of the genome. Conclusions The optimized SISPA protocol presented here produces amplified product that when sequenced will give high quality data that can be used for de novo assembly. The protocol requires only a single viral plaque or as little as 10 pg of DNA template, which will facilitate rapid identification of viruses during an outbreak and viruses that are difficult to propagate.
Calculation of arterial wall temperature in atherosclerotic arteries: effect of pulsatile flow, arterial geometry, and plaque structure
BACKGROUND: This paper presents calculations of the temperature distribution in an atherosclerotic plaque experiencing an inflammatory process; it analyzes the presence of hot spots in the plaque region and their relationship to blood flow, arterial geometry, and inflammatory cell distribution. Determination of the plaque temperature has become an important topic because plaques showing a temperature inhomogeneity have a higher likelihood
Obdulia Ley; Taehong Kim
Measurement of intima-media thickness vs. carotid plaque: uses in patient care, genetic research and evaluation of new therapies
Intima-media thickness (IMT) has been measured for over 20 years, and is widely regarded as a surrogate for atherosclerosis. However, inthe carotidarteries atherosclero- sis is focal, manifesting as plaques. IMT is often measured deliberately where no plaque exists, or multiple measure- ments may be averaged, including only one or two that intersect plaque. IMTand plaque are biologically and geneti- cally
J. David Spence
[Ultrasound-guided ESWT in Peyronie's disease plaques].
The aim of the study was to check the efficiency of shock waves in the treatment of Peyronie's disease. The instrument, because of its lithotriptic power, already used in the treatment of orthopedic disease and salivary stones, can be used to break plaques in induratio penis plastica. A total of 481 patients affected with Peyronie's disease were entered into a prospective trial. Patients with big plaques or with an initial stage of degeneration were excluded. We divided the patients into three treatment groups: a) shock waves alone in 56 patients; b) a combination of shock waves and calcioantagonist (perilesional injection) in 324 patients; c) calcioantagonist alone in 101 patients. The group of 101 patients (group C) treated during the previous 2 years with a medical therapy based only on the injection of calcioantagonist, was used as a control group. Ultrasound evaluation of the treated plaques showed a reduction of size in 27/56 patients of the group A, in 159/324 patients of the group B and in 39/101 patients of group C. Painful erection improved in the 91.5% of group B, against the 45.7% of group C. Furthermore, we pointed out, with interviews to the patients, a considerable improvement of the pain and of the sexual performances. The therapeutic association of shock waves with calcioantagonist injections is an effective non-operative treatment for the stabilization of Peyronie's disease. PMID:11221076
Mirone, V; Palmieri, A; Granata, A M; Piscopo, A; Verze, P; Ranavolo, R
Supragingival plaque microbial analysis in reflection to caries experience
Background Dental caries develops as a result of the metabolism of carbohydrates by cariogenic bacteria present in a complex biofilm. The present study aimed to examine if bacteria in pooled supragingival plaque samples quantified using a "checkerboard DNA-DNA hybridization" based panel of caries-related bacteria, could reflect the caries experience in a manner similar to saliva samples analysed using a chair-side method in a previous investigation. Methods A total of 86 mothers and their children aged 4–6 years and 12–16 years old participated. Caries experience (DMFT/dmft; Decayed, Missing and Filled Teeth for permanent and primary teeth) was registered clinically and radiographically. Caries was recorded at the D3 level (caries into dentine). The D/d component was divided into three categories. A pooled supragingival plaque sample per participant was obtained from posterior approximal sites. Analyses of 15 bacterial species were performed using the checkerboard DNA-DNA hybridisation technique. Results No significant relationships were found between the bacterial scores and DMFT/dmft nor D/d groups. Conclusions Unlike the saliva samples and the chair-side method, interproximal pooled plaque samples analysed using the "checkerboard DNA-DNA hybridization technique" did not reveal any significant relations between the bacterial counts and the caries experience.
Identification of amyloid plaques in retinas from Alzheimer's patients and noninvasive in vivo optical imaging of retinal plaques in a mouse model
Noninvasive monitoring of ?-amyloid (A?) plaques, the neuropathological hallmarks of Alzheimer's disease (AD), is critical for AD diagnosis and prognosis. Current visualization of A? plaques in brains of live patients and animal models is limited in specificity and resolution. The retina as an extension of the brain presents an appealing target for a live, noninvasive optical imaging of AD if
Maya Koronyo-Hamaoui; Yosef Koronyo; Alexander V. Ljubimov; Carol A. Miller; MinHee K. Ko; Keith L. Black; Michal Schwartz; Daniel L. Farkas
Shed Membrane Microparticles With Procoagulant Potential in Human Atherosclerotic Plaques A Role for Apoptosis in Plaque Thrombogenicity
Background—The specific role of apoptosis in human atherosclerosis remains unknown. During apoptotic cell death, phosphatidylserine exposure on the cell surface confers a high tissue-factor (TF)- dependent procoagulant activity. Methods and Results—In this study, we examined the role of apoptotic cell death in the promotion of plaque thrombogenicity. TF expression and its relation to apoptosis was analyzed in 16 human atherosclerotic
Ziad Mallat; Benedicte Hugel; Jeanny Ohan; Guy Leseche; Jean-Marie Freyssinet; Alain Tedgui
Elucidating atherosclerotic vulnerable plaque rupture by modeling cross substitution of ApoE-/- mouse and human plaque components stiffnesses.
The structure of mouse atherosclerotic lesions may differ from that of humans, and mouse atherosclerotic plaques do not rupture except in some specific locations such as the brachiocephalic artery. Recently, our group was the first to observe that the amplitudes of in vivo stresses in ApoE-/- mouse aortic atherosclerotic lesions were much lower and differed from those found in a previous work performed on human lesions. In this previous preliminary work, we hypothesized that the plaque mechanical properties (MP) may in turn be responsible for such species differences. However, the limited number of human samples used in our previous comparative study was relevant but not sufficient to broadly validate such hypothesis. Therefore, in this study, we propose an original finite element strategy that reconstructs the in vivo stress/strain (IVS/S) distributions in ApoE-/- artherosclerotic vessels based on cross substitution of ApoE-/- mouse and human plaque components stiffnesses and including residual stress/strain (RS/S). Our results: (1) showed that including RS/S decreases by a factor 2 the amplitude of maximal IVS/S, and more importantly, (2) demonstrated that the MP of the ApoE-/- plaque constituents are mainly responsible for the low level-compared with human-of intraplaque stress in ApoE-/- mouse aortic atherosclerotic lesions (8.36 ± 2.63 kPa vs. 182.25 ± 55.88 kPa for human). Our study highlights that such differences in the distribution and amplitude of vessel wall stress might be one key feature for explaining for the difference in lesion stability between human coronary and mouse aortic lesions. PMID:21986797
Ohayon, Jacques; Mesnier, Nicolas; Broisat, Alexis; Toczek, Jakub; Riou, Laurent; Tracqui, Philippe
Antibacterial agents in the control of supragingival plaque--a review.
This review considers the main agents which have been used as antibacterial agents in mouthwashes and other vehicles to inhibit the growth of supragingival plaque. The agents discussed are bisguanide antiseptics, quaternary ammonium compounds, phenolic antiseptics, hexetidine, povidone iodine, triclosan, delmopinol, salifluor, metal ions, sanguinarine, propolis and oxygenating agents. The plaque inhibitory, anti-plaque and anti-gingivitis properties of these agents are considered along with their substantivity, safety and possible clinical usefulness. Clinical trials of these agents that have been published are also reported. The possible clinical uses of antiseptic mouthwashes are finally considered along with some advice about assessing manufacturers claims. Throughout this review the terms plaque inhibitory, anti-plaque and anti-gingivitis have been used according to the clarification of terminology suggested by the European Federation of Periodontology at its second workshop. This defines a plaque inhibitory effect as one reducing plaque to levels insufficient to prevent the development of gingivitis; an anti-plaque effect as one which produces a prolonged and profound reduction in plaque sufficient to prevent the development of gingivitis; and anti-gingivitis as an anti-inflammatory effect on the gingival health not necessarily mediated through an effect on plaque. PMID:10230103
Eley, B M
Emergence of dendritic cells in rupture-prone regions of vulnerable carotid plaques.
Dendritic cells (DC), which are critically involved in various immunological disorders, were detected in atherosclerotic plaques in 1995. Since DC might be related to the immunological processes in atherosclerosis (AS), we analyzed the emergence of DC and other inflammatory cells in different stages of AS. Serial cross-sections of 44 carotid specimens were immunohistochemically analyzed for the presence of DC, T cells, macrophages, and HLA-DR. Atherosclerotic specimens were histologically defined as initial lesions, advanced stable, or vulnerable plaques. In initial lesions significantly lower DC numbers were detected than in advanced plaques (P < 0.001). For advanced plaques, DC numbers were significantly higher in vulnerable than in stable plaques (P = 0.005). In contrast to initial lesions, approximately 70% of DC in advanced plaques exhibited a mature phenotype (CD83+, DC-LAMP+), indicating a functional activity of DC. In plaques of patients with acute ischemic symptoms DC numbers were markedly elevated (P = 0.03), whereas significantly lower DC numbers and more often a stable plaque morphology were detected in statin-treated patients (P = 0.02). DC clusters with a strong HLA-DR expression and frequent DC-T cell contacts were located particularly in the rupture-prone plaque regions and at complications. The results of the present study indicate that DC might contribute to plaque destabilization through an activation of T cells. PMID:15306181
Yilmaz, Atilla; Lochno, Marlene; Traeg, Friedemann; Cicha, Iwona; Reiss, Christine; Stumpf, Christian; Raaz, Dorette; Anger, Thomas; Amann, Kerstin; Probst, Thomas; Ludwig, Josef; Daniel, Werner G; Garlichs, Christoph D
Retention of antimicrobial activity in plaque and saliva following mouthrinse use in vivo.
The aim of this study was to determine the contribution of plaque and saliva towards the prolonged activity, also called substantivity, of three antimicrobial mouthrinses (Listerine®, Meridol®, Crest Pro Health®), used in combination with a toothpaste (Prodent Coolmint®). Volunteers brushed for 4 weeks with a toothpaste without antimicrobial claims, while during the last 2 weeks half of the volunteers used an antimicrobial mouthrinse in addition to brushing. At the end of the experimental period, plaque and saliva samples were collected 6 h after oral hygiene, and bacterial concentrations and viabilities were determined. The contribution of plaque and saliva towards substantivity was assessed by combining plaque obtained after mechanical cleaning only with plaque and saliva obtained after additional use of an antimicrobial rinse. Subsequently, resulting viabilities of the combined plaques were determined. The viabilities of plaque samples after additional rinsing with mouthrinses were lower than of plaque obtained after mechanical cleaning only, regardless of the rinse involved. Moreover, plaque collected 6 h after rinsing with antimicrobial mouthrinses contained a surplus of antimicrobial activity. Only Listerine showed decreased viability in saliva, but none of the mouthrinses showed any residual antimicrobial activity in saliva. The findings indicate that plaque left behind after mechanical cleaning contributes to the prolonged substantivity of antimicrobial mouthrinses. PMID:20838045
Otten, M P T; Busscher, H J; van der Mei, H C; Abbas, F; van Hoogmoed, C G
Summary Objective The purpose of this study was to describe the pattern of dental plaque accumulation in mechanically ventilated adults. Accumulation of dental plaque and bacterial colonization of the oropharynx is associated with a number of systemic diseases including ventilator associated pneumonia. Research Methodology/Design Data were collected from mechanically ventilated critically ill adults (n=137), enrolled within 24 hours of intubation. Dental plaque, counts of decayed, missing and filled teeth and systemic antibiotic use was assessed on study days 1, 3, 5 and 7. Dental plaque averages per study day, tooth type and tooth location were analyzed. Setting Medical Respiratory, Surgical Trauma and Neuroscience ICU's of a large tertiary care center in the southeast United States. Results Plaque: All surfaces > 60% plaque coverage from day 1 to day 7; Molars and Premolars contained greatest plaque average >70%. Systemic antibiotic use on day 1 had no significant effect on plaque accumulation on day 3 (p=0.73). Conclusions Patients arrive in critical care units with preexisting oral hygiene issues. Dental plaque tends to accumulate in the posterior teeth (molars and premolars) that may be hard for nurses to visualize and reach; this problem may be exacerbated by endotracheal tubes and other equipment. Knowing accumulation trends of plaque will guide the development of effective oral care protocols.
Jones, Deborah J.; Munro, Cindy L.; Grap, Mary Jo
No Calcium-Fluoride-Like Deposits Detected in Plaque Shortly after a Sodium Fluoride Mouthrinse
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 ?g/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.
Vogel, G.L.; Tenuta, L.M.A.; Schumacher, G.E.; Chow, L.C.
Early Differential Changes in Coronary Plaque Composition According to Plaque Stability Following Statin Initiation in Acute Coronary Syndrome: Classification and Analysis by Intravascular Ultrasound-Virtual Histology
Purpose The aim of this study was to demonstrate the early effects of statin treatment on plaque composition according to plaque stability on Intravascular Ultrasound-Virtual Histology at 6 months after a coronary event. Previous trials have demonstrated that lipid lowering therapy with statins decreases plaque volume and increases plaque echogenicity in patients with coronary artery disease. Materials and Methods Fifty-four patients (54 lesions) with acute coronary syndrome were prospectively enrolled. We classified and analyzed the target plaques into two types according to plaque stability: thin-cap fibroatheroma (TCFA, n=14) and non-TCFA (n=40). The primary end point was change in percent necrotic core in the 10-mm subsegment with the most disease. Results After 6 months of statin therapy, no change was demonstrated in the mean percentage of necrotic core (18.7±8.5% to 20.0±11.0%, p=0.38). There was a significant reduction in necrotic core percentage in patients with TCFA (21.3±7.2% to 14.4±8.9%, p=0.017), but not in patients with non-TCFA. Moreover, change in percent necrotic core was significantly correlated with change in high-sensitivity C-reactive protein levels (r=0.4, p=0.003). Changes in low-density lipoprotein cholesterol levels and lipid core percentage demonstrated no significant associations. Conclusion A clear reduction of lipid core was observed only for the TCFA plaque type, suggesting that changes in plaque composition following statin therapy might occur earlier in vulnerable plaque than in stable plaque; the effect may be related to the anti-inflammatory effects of statins.
Hwang, Dae Seong; Shin, Eun Seok; Kim, Shin Jae; Lee, Jun Ho; Kim, Jong Min
The Relationship of Epicardial Fat Volume to Coronary Plaque, Severe Coronary Stenosis, and High-Risk Coronary Plaque Features Assessed by Coronary CT Angiography
Background Associations of epicardial fat volume (EFV) measured on non-contrast cardiac computed tomography (NCT) include coronary plaque, myocardial ischemia and adverse cardiac events. Objectives This study aimed to define the relationship of EFV to coronary plaque type, severe coronary stenosis, and to the presence of high-risk plaque features (HRPFs). Methods We retrospectively evaluated 402 consecutive patients, with no prior history of coronary artery disease, who underwent same day non-contrast cardiac computed tomography (NCT) and coronary CT angiography (CTA). EFV was measured on NCT using validated, semi-automated, software. The coronary arteries were evaluated for coronary plaque type [calcified (CP), non-calcified (NCP) or partially-calcified (MP)] and coronary stenosis severity ?70% using coronary CTA. For patients with NCP and PCP, 2 high risk plaque features were evaluated: Low-attenuation plaque and positive remodeling. Results There were 402 patients with a median age of 66 years (range 23–92) of whom 226 (56%) were male. The EFV was larger in patients with CP (112 ± 55 cm3 vs. 89 ± 39 cm3), PCP (110 ± 57 cm3 vs. 98 ± 45 cm3) and NCP (115 ± 44 cm3 vs. EFV 100 ± 52 cm3. In the 192 patients with PCP or NCP, on multivariable analysis, after adjusting for conventional cardiovascular risk factors, EFV was an independent predictor of ?70% coronary artery stenosis (OR 3.0, 95% CI 1.3–6.6, p=0.008), any high risk plaque features (OR 1.7, 95% CI 0.9–3.4, p=0.04) and low attention plaque (OR 2.4, 95% CI 1.1–5.1, p=0.02), but not of positive remodeling. Conclusions Epicardial fat volume is larger in patients with CP, PCP and NCP. In patients with NCP and PCP, EFV is significantly associated with severe coronary stenosis, high risk plaque features and low attenuation plaque.
Rajani, Ronak; Shmilovich, Haim; Nakazato, Ryo; Nakanishi, Rine; Otaki, Yuka; Cheng, Victor Y.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Slomka, Piotr J.; Min, James K.; Berman, Daniel S.; Dey, Damini
Rosuvastatin improves plaque morphology in cerebral embolism patients with normal low-density lipoprotein and severe aortic arch plaque.
The effect of rosuvastatin was investigated on complicated aortic arch plaque (CAP) morphology and lipid profiles in acute cerebral embolism (CE) patients with normal low-density lipoprotein-cholesterol (LDL-c) levels. Transesophageal echocardiography (TEE) studies were performed in 56 consecutive CE patients with LDL-c less than 140 mg/dL who were not taking lipid-lowering agents at baseline. CAP observed by TEE was defined as the presence of greater than 4-mm diameter, ulcerated, or mobile aortic plaque. Patients were divided into those with CAP versus without CAP (group A, n = 24, age 69 ± 8 years) and without CAP (group B, n = 32, age 62 ± 10 years). Of the 24 group A patients, 18 received 5 mg/d of rosuvastatin for 6 months and had follow-up TEE studies. In Group A, the baseline values of high-density lipoprotein-cholesterol (HDL-c) and apolipoprotein A-1 (ApoA-1) were significantly lower than in Group B (44 ± 15 versus 55 ± 15 mg/dL, P = .0059; 103 ± 19 versus 137 ± 25 mg/dL, P = .0006, respectively) and age and serum high-sensitivity C-reactive protein concentration were significantly higher (69 ± 8 vs. 62 ± 10 years, P = .0080; 2.34 ± 3.05 vs. 0.67 ± 1.00 mg/dL, P = .0054, respectively). By multivariate logistic regression analysis, ApoA-1 was shown to be an independent predictor of CAP (odds ratio = .894, 95% confidence intervals .800-.996, P = .0483). In the 18 group A patients receiving rosuvastatin for 6 months, aortic arch plaque diameter and serum LDL-c were significantly decreased (5.8 ± 2.2 to 5.1 ± 2.1 mm, P = .0377; 110 ± 23 to 81 ± 23 mg/dL, P = .0008, respectively), whereas serum HDL-c and ApoA-1 concentrations were significantly increased (42 ± 8 to 52 ± 9 mg/dL, P = .0002; 109 ± 22 to 135 ± 15 mg/dL, P = .0002, respectively). Plaques were morphologically improved in 11 patients, unchanged in 6, and worsened in 1. These data suggest that rosuvastatin improves plaque morphology concomitant with improving lipid profiles in CE patients with normal LDL-c levels. PMID:24739590
Kaneko, Kazuyoshi; Saito, Hiroki; Takahashi, Tetsuya; Kiribayashi, Nobuyuki; Omi, Koki; Sasaki, Toshiki; Niizeki, Takeshi; Sugawara, Shigeo; Akasaka, Masahiro; Kubota, Isao
Numbers and types of asbestos fibers in subjects with pleural plaques.
The authors analyzed asbestos fibers in lung samples from 20 subjects with pleural plaques discovered on autopsy and compared the findings to their previous analyses of lungs from subjects with little or no asbestos exposure and no plaques. Sixteen of the subjects with plaques had a history of exposure to asbestos. The authors used electron-optical methods and energy-dispersive x-ray spectroscopy to investigate the structure, diffraction patterns, and chemical composition of the asbestos fibers. The subjects with plaques had significantly higher median concentrations than the control subjects for amosite and crocidolite fibers (P less than 0.01) but not for the other fiber types. Minimal microscopic asbestosis was present in the 3 subjects who had the highest amosite concentrations. In the subjects with typical plaques, a history of asbestos exposure, and more fibers than in the control population, the relation of the plaques to asbestos was confirmed; for others, it was uncertain. PMID:7124907
Warnock, M L; Prescott, B T; Kuwahara, T J
Randall's plaque of patients with nephrolithiasis begins in basement membranes of thin loops of Henle
Our purpose here is to test the hypothesis that Randall's plaques, calcium phosphate deposits in kidneys of patients with calcium renal stones, arise in unique anatomical regions of the kidney, their formation conditioned by specific stone-forming pathophysiologies. To test this hypothesis, we performed intraoperative biopsies of plaques in kidneys of idiopathic-calcium-stone formers and patients with stones due to obesity-related bypass procedures and obtained papillary specimens from non–stone formers after nephrectomy. Plaque originates in the basement membranes of the thin loops of Henle and spreads from there through the interstitium to beneath the urothelium. Patients who have undergone bypass surgery do not produce such plaque but instead form intratubular hydroxyapatite crystals in collecting ducts. Non–stone formers also do not form plaque. Plaque is specific to certain kinds of stone-forming patients and is initiated specifically in thin-limb basement membranes by mechanisms that remain to be elucidated.
Evan, Andrew P.; Lingeman, James E.; Coe, Fredric L.; Parks, Joan H.; Bledsoe, Sharon B.; Shao, Youzhi; Sommer, Andre J.; Paterson, Ryan F.; Kuo, Ramsay L.; Grynpas, Marc
Inhibition of plaque neovascularization reduces macrophage accumulation and progression of advanced atherosclerosis
Plaque angiogenesis promotes the growth of atheromas, but the functions of plaque capillaries are not fully determined. Neovascularization may act as a conduit for the entry of leukocytes into sites of chronic inflammation. We observe vasa vasorum density correlates highly with the extent of inflammatory cells, not the size of atheromas in apolipoprotein E-deficient mice. We show atherosclerotic aortas contain activities that promote angiogenesis. The angiogenesis inhibitor angiostatin reduces plaque angiogenesis and inhibits atherosclerosis. Macrophages in the plaque and around vasa vasorum are reduced, but we detect no direct effect of angiostatin on monocytes. After angiogenesis blockade in vivo, the angiogenic potential of atherosclerotic tissue is suppressed. Activated macrophages stimulate angiogenesis that can further recruit inflammatory cells and more angiogenesis. Our findings demonstrate that late-stage inhibition of angiogenesis can interrupt this positive feedback cycle. Inhibition of plaque angiogenesis and the secondary reduction of macrophages may have beneficial effects on plaque stability.
Moulton, Karen S.; Vakili, Khashayar; Zurakowski, David; Soliman, Mohsin; Butterfield, Catherine; Sylvin, Erik; Lo, Kin-Ming; Gillies, Stephen; Javaherian, Kashi; Folkman, Judah
Characterization of atherosclerotic plaque-depositions by infrared, Raman and CARS microscopy
NASA Astrophysics Data System (ADS)
Atherosclerotic plaques are mainly composed of proteoglycans, triglycerides, cholesterol, cholesterolester and crystalline calcium. From histopathological characterizations it is known that the composition of these atherosclerotic plaques can vary to a great extent, due to different risk factors as smoking, hyperlipedemia, or genetic background ect. The individual plaque components can be spectroscopically easily identified. Furthermore, spectroscopic imaging technologies offer the possibility to study the plaque compositions in a more quantitative manner than traditional staining techniques. Here, we compare the potential of IR, Raman and CARS microscopy to characterize the constitution of atherosclerotic plaques as well as the structure of the surrounding tissue. For data analysis and image reconstruction spectral decomposition algorithms such as vertex component analysis (VCA) were introduced. The results are in good agreement with the histopathology. Aim of the study is to correlate the compositional characteristics of atherosclerotic plaques with individual disease patterns.
Matthäus, Christian; Bergner, Gero; Krafft, Christoph; Dietzek, Benjamin; Romeike, Bernd F. M.; Brehm, Bernhard R.; Popp, Jürgen
Non-invasive measurement of coronary plaque from coronary CT angiography and its clinical implications.
Coronary CT angiography (CTA) is increasingly used worldwide for direct, non-invasive evaluation of the coronary arteries. Advances in computed tomography (CT) technology over the last decade have enabled such reliable imaging of the coronary arteries. Beyond arterial stenosis, coronary CTA also permits assessment of atherosclerotic plaque (including plaque burden) and coronary artery remodeling, previously only achievable through invasive means. It has been shown that coronary plaque volumes for non-calcified and mixed plaques and the arterial remodeling index, correlate closely with invasive intravascular ultrasound. Several studies have also shown a strong relationship of adverse plaque features imaged by coronary CTA with acute coronary syndrome, all-cause death, major adverse cardiovascular events and myocardial ischemia. The aim of this review is to summarize current methods for quantitative measurement of atherosclerotic plaque features from coronary CTA and to discuss their clinical implications. PMID:23984930
Dey, Damini; Schuhbaeck, Annika; Min, James K; Berman, Daniel S; Achenbach, Stephan
Human Serum Albumin Cys(34) Oxidative Modifications following Infiltration in the Carotid Atherosclerotic Plaque.
Objectives. To evaluate if the prooxidant environment present in atherosclerotic plaque may oxidatively modify filtered albumin. Methods. Fluorescein-5-maleimide labelled plasma samples and plaque extracts from 27 patients who had undergone carotid endarterectomy were analysed through nonreducing SDS-PAGE for albumin-Cys(34) oxidation. Furthermore, degree and pattern of S-thiolation in both circulating and plaque-filtered albumin were assayed. Results. Albumin filtered in the atherosclerotic plaque showed higher levels of Cys(34) oxidative modifications than the corresponding circulating form as well as different patterns of S-thiolation. Conclusions. Data indicate that the circulating albumin, once filtered in plaque, undergoes Cys(34) oxidative modifications and demonstrate for the first time that albumin is a homocysteine and cysteinylglycine vehicle inside the plaque environment. PMID:24738021
Lepedda, Antonio Junior; Zinellu, Angelo; Nieddu, Gabriele; De Muro, Pierina; Carru, Ciriaco; Spirito, Rita; Guarino, Anna; Piredda, Franco; Formato, Marilena
Numbers and types of asbestos fibers in subjects with pleural plaques.
The authors analyzed asbestos fibers in lung samples from 20 subjects with pleural plaques discovered on autopsy and compared the findings to their previous analyses of lungs from subjects with little or no asbestos exposure and no plaques. Sixteen of the subjects with plaques had a history of exposure to asbestos. The authors used electron-optical methods and energy-dispersive x-ray spectroscopy to investigate the structure, diffraction patterns, and chemical composition of the asbestos fibers. The subjects with plaques had significantly higher median concentrations than the control subjects for amosite and crocidolite fibers (P less than 0.01) but not for the other fiber types. Minimal microscopic asbestosis was present in the 3 subjects who had the highest amosite concentrations. In the subjects with typical plaques, a history of asbestos exposure, and more fibers than in the control population, the relation of the plaques to asbestos was confirmed; for others, it was uncertain.
Warnock, M. L.; Prescott, B. T.; Kuwahara, T. J.
Membrane Type 1 Matrix Metalloproteinase Expression in Human Atherosclerotic Plaques Evidence for Activation by Proinflammatory Mediators
Background—Matrix metalloproteinases (MMPs) are expressed in atherosclerotic plaques, where in their active form, they may contribute to vascular remodeling and plaque disruption. In this study, we tested the hypothesis that membrane type 1 MMP (MT1-MMP), a novel transmembrane MMP that activates pro-MMP-2 (gelatinase A), is expressed in human atherosclerotic plaques and that its expression is regulated by proinflammatory molecules. Methods
Tripathi B. Rajavashisth; Xiao-Ping Xu; Stefan Jovinge; Simcha Meisel; Xiao-Ou Xu; Ning-Ning Chai; Michael C. Fishbein; Sanjay Kaul; Bojan Cercek; Behrooz Sharifi; Prediman K. Shah
Genetic deletion or TWEAK blocking antibody administration reduce atherosclerosis and enhance plaque stability in mice.
Clinical complications associated with atherosclerotic plaques arise from luminal obstruction due to plaque growth or destabilization leading to rupture. Tumour necrosis factor ligand superfamily member 12 (TNFSF12) also known as TNF-related weak inducer of apoptosis (TWEAK) is a proinflammatory cytokine that participates in atherosclerotic plaque development, but its role in plaque stability remains unclear. Using two different approaches, genetic deletion of TNFSF12 and treatment with a TWEAK blocking mAb in atherosclerosis-prone mice, we have analysed the effect of TWEAK inhibition on atherosclerotic plaques progression and stability. Mice lacking both TNFSF12 and Apolipoprotein E (TNFSF12(-/-) ApoE(-/-) ) exhibited a diminished atherosclerotic burden and lesion size in their aorta. Advanced atherosclerotic plaques of TNFSF12(-/-) ApoE(-/-) or anti-TWEAK treated mice exhibited an increase collagen/lipid and vascular smooth muscle cell/macrophage ratios compared with TNFSF12(+/+) ApoE(-/-) control mice, reflecting a more stable plaque phenotype. These changes are related with two different mechanisms, reduction of the inflammatory response (chemokines expression and secretion and nuclear factor kappa B activation) and decrease of metalloproteinase activity in atherosclerotic plaques of TNFSF12(-/-) ApoE(-/-) . A similar phenotype was observed with anti-TWEAK mAb treatment in TNFSF12(+/+) ApoE(-/-) mice. Brachiocephalic arteries were also examined since they exhibit additional features akin to human atherosclerotic plaques associated with instability and rupture. Features of greater plaque stability including augmented collagen/lipid ratio, reduced macrophage content, and less presence of lateral xanthomas, buried caps, medial erosion, intraplaque haemorrhage and calcium content were present in TNFSF12(-/-) ApoE(-/-) or anti-TWEAK treatment in TNFSF12(+/+) ApoE(-/-) mice. Overall, our data indicate that anti-TWEAK treatment has the capacity to diminish proinflamatory response associated with atherosclerotic plaque progression and to alter plaque morphology towards a stable phenotype. PMID:24479820
Sastre, Cristina; Fernández-Laso, Valvanera; Madrigal-Matute, Julio; Muńoz-García, Begońa; Moreno, Juan A; Pastor-Vargas, Carlos; Llamas-Granda, Patricia; Burkly, Linda C; Egido, Jesús; Martín-Ventura, Jose L; Blanco-Colio, Luis M
(Shear) Strain Imaging Used in Noninvasive Detection of Vulnerable Plaques in the Carotid Arterial Wall
\\u000a The primary trigger for myocardial infarction and stroke is destabilization of atherosclerotic plaques. The chance of a plaque\\u000a to rupture is related to its composition and geometry. Ultrasound (shear) strain imaging allows assessment of local tissue\\u000a mechanics and possible risk assessment of vulnerable plaques. Intravascularly, in coronary arteries using a catheter, strain\\u000a imaging has been demonstrated to be successful. At
T. Idzenga; H. H. G. Hansen; C. L. Korte
View of Commemorative plaque left on moon at Hadley-Apennine landing site
NASA Technical Reports Server (NTRS)
A close-up view of a commemorative plaque left on the Moon at the Hadley-Apennine landing site in memory of 14 NASA astronauts and USSR cosmonauts, now deceased. Their names are inscribed in alphabetical order on the plaque. The plaque was stuck in the lunar soil by Astronauts David R. Scott and James B. Irwin during their Apollo 15 lunar surface extravehicular activity. The tin, man-like object represents the figure of a fallen astronaut/cosmonaut.
A computational fluid-structure interaction model for plaque vulnerability assessment in atherosclerotic human coronary arteries
NASA Astrophysics Data System (ADS)
Coronary artery disease is responsible for a third of global deaths worldwide. Computational simulations of blood flow can be used to understand the interactions of artery/plaque and blood in coronary artery disease and to better predict the rupture of atherosclerotic plaques. So far, the mechanical properties of animals' coronary artery have been mostly used for hemodynamic simulation of atherosclerotic arteries. The mechanical properties of animals' coronary arteries are often not accurate enough and can be only used for an approximate estimation and comparative assessment of the cognate parameters in human. In this study, a three-dimensional (3D) computational fluid-structure interactions model with three different plaque types is presented to perform a more accurate plaque vulnerability assessment for human atherosclerotic plaques. The coronary arteries of twenty-two male individuals were removed during autopsy and subjected to uniaxial tensile loading. The hyperelastic material coefficients of coronary arteries were calculated and implemented to the computational model. The fully coupled fluid and structure models were solved using the explicit dynamics finite element code LS-DYNA. The normal and shear stresses induced within the plaques were significantly affected by different plaque types. The highest von Mises (153 KPa) and shear (57 KPa) stresses were observed for hypocellular plaques, while the lowest von Mises (70 KPa) and shear (39 KPa) stresses were observed on the stiffer calcified plaques. The results suggest that the risk of plaque rupture due to blood flow is lower for cellular and hypocellular plaques, while higher for calcified plaques with low fracture stresses.
Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza; Haghpanahi, Mohammad
Matrix metalloproteinase-2 of human carotid atherosclerotic plaques promotes platelet activation. Correlation with ischaemic events.
Purified active matrix metalloproteinase-2 (MMP-2) is able to promote platelet aggregation. We aimed to assess the role of MMP-2 expressed in atherosclerotic plaques in the platelet-activating potential of human carotid plaques and its correlation with ischaemic events. Carotid plaques from 81 patients undergoing endarterectomy were tested for pro-MMP-2 and TIMP-2 content by zymography and ELISA. Plaque extracts were incubated with gel-filtered platelets from healthy volunteers for 2 minutes before the addition of a subthreshold concentration of thrombin receptor activating peptide-6 (TRAP-6) and aggregation was assessed. Moreover, platelet deposition on plaque extracts immobilised on plastic coverslips under high shear-rate flow conditions was measured. Forty-three plaque extracts (53%) potentiated platelet aggregation (+233 ± 26.8%), an effect prevented by three different specific MMP-2 inhibitors (inhibitor II, TIMP-2, moAb anti-MMP-2). The pro-MMP-2/TIMP-2 ratio of plaques potentiating platelet aggregation was significantly higher than that of plaques not potentiating it (3.67 ± 1.21 vs 1.01 ± 0.43, p<0.05). Moreover, the platelet aggregation-potentiating effect, the active-MMP-2 content and the active MMP-2/pro-MMP-2 ratio of plaque extracts were significantly higher in plaques from patients who developed a subsequent major cardiovascular event. In conclusion, atherosclerotic plaques exert a prothrombotic effect by potentiating platelet activation due to their content of MMP-2; an elevated MMP-2 activity in plaques is associated with a higher rate of subsequent ischaemic cerebrovascular events. PMID:24499865
Lenti, M; Falcinelli, E; Pompili, M; de Rango, P; Conti, V; Guglielmini, G; Momi, S; Corazzi, T; Giordano, G; Gresele, P
Intraplaque haemorrhages as the trigger of plaque vulnerability
Atherothrombosis remains one of the main causes of morbidity and mortality in the western countries. Human atherothrombotic disease begins early in life in relation to circulating lipid retention in the inner vascular wall. Risk factors enhance the progression towards clinical expression: dyslipidaemia, diabetes, smoking, hypertension, ageing, etc. The evolution from the initial lipid retention in the arterial wall to clinical events is a continuum of increasingly complex biological processes. Current strategies to fight the consequences of atherothrombosis are orientated either towards the promotion of a healthy life style1 and preventive treatment of risk factors, or towards late interventional strategies.2 Despite this therapeutic arsenal, the incidence of clinical events remains dramatically high,3 dependent, at least in part, on the increasing frequency of type 2 diabetes and ageing. But some medical treatments, focusing only on prevention of the metabolic risk, have failed to reduce cardiovascular mortality, thus illustrating that our understanding of the pathophysiology of human atherothrombosis leading to clinical events remain incomplete. New paradigms are now emerging which may give rise to novel experimental strategies to improve therapeutic efficacy and prediction of disease progression. Recent studies strengthen the concept that the intraplaque neovascularization and bleeding (Figure 1, upper panel) are events that could play a major role in plaque progression and leucocyte infiltration, and may also serve as a measure of risk for the development of future events. The recent advances in our understanding of IntraPlaque Hemorrhage as a critical event in triggering acute clinical events have important implications for clinical research and possibly future clinical practice. Figure 1Macroscopic view and schematic representation of the detrimental consequences of intraplaque haemorrhages on plaque biology and stability.
Michel, Jean-Baptiste; Virmani, Renu; Arbustini, Eloisa; Pasterkamp, Gerard
The effect of a combination of copper and hexetidine on plaque formation and the amount of copper retained by dental plaque bacteria.
Zn++ in combination with hexetidine exerts a synergistic plaque inhibition. Studies in our laboratory on the mechanism of this effect suggested that Cu++ and hexetidine may have a similar combination effect. This hypothesis was tested in vivo on a human test panel in a double-blind crossover study. The amount of Cu++ retained by plaque bacteria in vitro was also evaluated. Seven volunteers rinsed with the solutions for 1 min twice daily for 5 days. The test solutions were H2O, 1.0 mM CuSO4, 2.0 mM hexetidine, and the last two in combination. During the test period no oral hygiene was allowed, and sucrose-containing chewing gum was used to enhance plaque formation. The plaque index scores after rinsing with the combination were significantly (p less than 0.05) lower than those of the other solutions. The effect of hexetidine on Cu++ retention in plaque bacteria was evaluated in plaque samples (n = 3) grown anaerobically overnight in PPLO medium. The bacteria were washed five times, digested in concentrated HNO3, and Cu++ determined by atomic absorption. The presence of hexetidine resulted in a significantly greater amount of Cu++ retained by bacteria at all CuSO4 concentrations. It is suggested that the nonpolar nature of the hexetidine molecule enables Cu++ bound to hexetidine to pass into the bacterial cell. Within the cell, Cu++ can interfere with bacterial metabolism, giving a reduction in plaque growth. PMID:3481160
Grytten, J; Tollefsen, T; Afseth, J
Consensus guidelines for the management of plaque psoriasis.
The Canadian Guidelines for the Management of Plaque Psoriasis were reviewed by the entire National Psoriasis Foundation Medical Board and updated to include newly approved agents such as ustekinumab and to reflect practice patterns in the United States, where the excimer laser is approved for psoriasis treatment. Management of psoriasis in special populations is discussed. In the updated guidelines, we include sections on children, pregnant patients or pregnant partners of patients, nursing mothers, the elderly, patients with hepatitis B or C virus infections, human immunodeficiency virus-infected patients, and patients with malignant neoplasms, as well as sections on tumor necrosis factor blockers, elective surgery, and vaccinations. PMID:22250239
Hsu, Sylvia; Papp, Kim Alexander; Lebwohl, Mark G; Bagel, Jerry; Blauvelt, Andrew; Duffin, Kristina Callis; Crowley, Jeffrey; Eichenfield, Lawrence F; Feldman, Steven R; Fiorentino, David F; Gelfand, Joel M; Gottlieb, Alice B; Jacobsen, Carmen; Kalb, Robert E; Kavanaugh, Arthur; Korman, Neil J; Krueger, Gerald G; Michelon, Melissa A; Morison, Warwick; Ritchlin, Christopher T; Stein Gold, Linda; Stone, Stephen P; Strober, Bruce E; Van Voorhees, Abby S; Weiss, Stefan C; Wanat, Karolyn; Bebo, Bruce F
Investigation of atherosclerotic plaque by high-frequency EPR
NASA Astrophysics Data System (ADS)
We present a comparative study of samples of aorta walls from male patients with atherosclerosis and hydroxyapatite powders with the average size of crystallites of 30 nm synthesized by the wet precipitation technique by using 94 GHz pulsed EPR. Origin of the observed paramagnetic centers is discussed. Supported by the electron microscopy and microanalysis, it is shown that EPR spectra from the calcified biological tissues correlates with those obtained in inorganic hydroxyapatites. The hypothesis about the important role of (nano)hydroxyapatite in formation of the mineral deposits and atherosclerotic plaque instability is further sustained.
Biktagirov, T. B.; Chelyshev, Yu A.; Gafurov, M. R.; Mamin, G. V.; Orlinskii, S. B.; Osin, Yu N.; Salakhov, M. Kh
First isolation of Streptococcus downei from human dental plaques.
In this study, we isolated four bacterial strains grown on mitis-salivarius sucrose bacitracin agar. The strains had similar biochemical characteristics to biotypes I or II of mutans streptococci. The four isolates were identified as Streptococcus downei by 16S rDNA and dextranase gene (dex) sequencing as well as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dex. To our knowledge, this is the first report of the isolation and identification of S. downei from dental plaque in humans. The results suggest that S. downei can inhabit the human oral cavity. PMID:16002238
Yoo, So Young; Kim, Kwan-Joong; Lim, Seong-Hoon; Kim, Kwang-Won; Hwang, Ho-Keel; Min, Byung-Moo; Choe, Son-Jin; Kook, Joong-Ki
Integrated IVUS-OCT Imaging for Atherosclerotic Plaque Characterization
For the diagnosis of atherosclerosis, biomedical imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed. The combined use of IVUS and OCT is hypothesized to remarkably increase diagnostic accuracy of vulnerable plaques. We have developed an integrated IVUS-OCT imaging apparatus, which includes the integrated catheter, motor drive unit, and imaging system. The dual-function imaging catheter has the same diameter of current clinical standard. The imaging system is capable for simultaneous IVUS and OCT imaging in real time. Ex vivo and in vivo experiments on rabbits with atherosclerosis were conducted to demonstrate the feasibility and superiority of the integrated intravascular imaging modality.
Li, Xiang; Li, Jiawen; Jing, Joe; Ma, Teng; Liang, Shanshan; Zhang, Jun; Mohar, Dilbahar; Raney, Aidan; Mahon, Sari; Brenner, Matthew; Patel, Pranav; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping
A fluorescence lifetime spectroscopy study of matrix metalloproteinases -2 and -9 in human atherosclerotic plaque
Matrix metalloproteinase (MMP) -2 and -9 play important roles in the progression of atherosclerosis. This study aims to determine whether MMP-2 and -9 content in the fibrotic caps of atherosclerotic plaque is correlated with plaque autofluorescence. A time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) system was used to measure the autofluorescence and assess the biochemical composition of human plaques obtained from carotid endarterectomy. Results presented here demonstrate for the first time the ability to characterize the biochemical composition as it relates to MMP-2 and -9 content in the atherosclerotic plaque cap using a label-free imaging technique implemented with a fiberoptic TR-LIFS system.
Phipps, Jennifer E.; Hatami, Nisa; Galis, Zorina S.; Baker, J. Dennis; Fishbein, Michael C.; Marcu, Laura
Scanning electron microscopy of growing dental plaque: a quantitative study with different mouth rinses.
The aim of this study was to quantify the influence of different mouth rinses on dental plaque. Wearing splints with enamel pieces 24 volunteers rinsed with essential oils, amine/stannous fluoride, or chlorhexidine digluconate (0.12%) mouth rinses. After 24, 48, 72, and 96 h the enamel pieces were analyzed by scanning electron microscopy. The counts of cocci and bacilli in different plaque layers and the plaque thickness were almost similar using essential oils and amine/stannous fluoride. These results differed significantly from those of chlorhexidine digluconate mouth rinses. The results for plaque thickness were without significant differences between the groups at any appointment. PMID:23758106
Jentsch, Holger; Mozaffari, Eshan; Jonas, Ludwig
Plaque assay and cloning of scrub typhus rickettsiae in irradiated L-929 cells.
It was demonstrated that gamma-irradiated L-929 cells support plaque formation by three strains of Rickettsia tsutsugamushi and representative species of the spotted fever and typhus group rickettsiae. Sensitivity of the plaque assay for detection of viable scrub typhus rickettsiae was similar to that achieved with intraperitoneal inoculation of random-bred mice. The concentration of irradiated cells and the temperature and length of incubation were all found to affect plaque size. A technique combining terminal dilution and plaque purification was used to obtain clones of three strains of scrub typhus rickettsiae. Images
Oaks, S C; Osterman, J V; Hetrick, F M
Bacteria Present in Carotid Arterial Plaques Are Found as Biofilm Deposits Which May Contribute to Enhanced Risk of Plaque Rupture
ABSTRACT 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.
Lanter, Bernard B.; Sauer, Karin
How Does Calcification Influence Plaque Vulnerability? Insights from Fatigue Analysis
Background. Calcification is commonly believed to be associated with cardiovascular disease burden. But whether or not the calcifications have a negative effect on plaque vulnerability is still under debate. Methods and Results. Fatigue rupture analysis and the fatigue life were used to evaluate the rupture risk. An idealized baseline model containing no calcification was first built. Based on the baseline model, we investigated the influence of calcification on rupture path and fatigue life by adding a circular calcification and changing its location within the fibrous cap area. Results show that 84.0% of calcified cases increase the fatigue life up to 11.4%. For rupture paths 10D far from the calcification, the life change is negligible. Calcifications close to lumen increase more fatigue life than those close to the lipid pool. Also, calcifications in the middle area of fibrous cap increase more fatigue life than those in the shoulder area. Conclusion. Calcifications may play a positive role in the plaque stability. The influence of the calcification only exists in a local area. Calcifications close to lumen may be influenced more than those close to lipid pool. And calcifications in the middle area of fibrous cap are seemly influenced more than those in the shoulder area.
Wu, Baijian; Pei, Xuan; Li, Zhi-Yong
[Microbiologic in vitro comparison of plaque-inhibiting mouthwashes].
The colonization on rat molars of S. sobrinus OMZ 176, S. mutans OMZ 376, or a combination S. sanguis OMZ 9 and S. sobrinus OMZ 176 after a short exposition to various fluoride solutions and disinfectants was tested in vitro. The test solutions included Act, Candida, Veadent, sodium fluoride, amine fluoride, stannous fluoride, zinc fluoride hexetidine, stannous fluoride/amine fluoride solutions, chlorhexidine and water. The sterilized rat molars were immersed in the above test solutions for 60 seconds, then incubated with streptococci in broth for 8 hours, again dipped into the same test solutions for 60 seconds and reincubated for an additional 30 hours. The streptococcal suspension contained 14C labelled sucrose solutions. The deposits on the molars were dissolved in 6N potassium hydroxide during 16 hours. Finally, the beta rays emitted by the dissolved radiolabelled suspension were counted using a scintillation counter. The sodium fluoride containing solutions exerted no or a very limited effect on the bacterial deposits. In contrast to the other test solutions, sanguinaria extract (Veadent mouth rinse) mildly inhibited the S. sobrinus and S. mutans deposits, but plaque formation by the combination of streptococci was not hampered. Zinc fluoride/hexetidine, amine fluoride and stannous fluoride/amine fluoride solutions had a distinct and significant inhibitory effect on S. sobrinus and S. mutans deposits, but only a weak effect when mixed cultures were used for plaque formation. Chlorhexidine significantly inhibited the deposits of the three bacterial strains used in these experiments. PMID:2913640
Altenhofen, E; Lutz, F; Guggenheim, B
Aminomalonic acid: identification in Escherichia coli and atherosclerotic plaque.
Aminomalonic acid (Ama) has been isolated from proteins of Escherichia coli and human atherosclerotic plaque. The presence of Ama has important biological implications because the malonic acid moiety potentially imparts calcium binding properties to protein. Ama was obtained by anaerobic alkaline hydrolysis and identified by chromatographic behavior, quantitative acid-mediated decarboxylation to glycine, and unambiguous gas chromatographic/mass spectral detection. The chromatographic, chemical, and mass spectral properties of naturally occurring Ama were identical to those of the synthetic compound. Amino acid analysis and GC/mass spectrometry also revealed the presence of beta-carboxyaspartic acid and gamma-carboxyglutamic acid in the base hydrolysate of human atherosclerotic plaque. The ratio of Ama to beta-carboxyaspartic acid to gamma-carboxyglutamic acid was 20:1:10, and the quantity of Ama per 1,000 glycine residues was 0.2. Ama is a relatively unstable, minor amino acid in complex structures such as bacteria or tissues. This may explain why it has escaped detection previously, despite intensive investigation.
Van Buskirk, J J; Kirsch, W M; Kleyer, D L; Barkley, R M; Koch, T H
PUVA treatment of erythrodermic and plaque type mycosis fungoides.
Five patients with plaque type mycosis fungoides (MF) and five patients with erythrodermic MF responded favorably to oral psoralen photochemotherapy (PUVA). The mean total UVA irradiation dose was less for erythrodermic than for plaque type MF, but the mean number of treatments to achieve clearing was greater in the erythrodermic patients. Histologic examination at clearing revealed persistence of an inflammatory infiltrate in the lower dermis in most cases. Subsequent recurrent lesions in five patients revealed a more extensive dermal inflammatory infiltrate, although findings were not always diagnostic of MF due to a lack of epidermal involvement. Resumption of more intensive PUVA therapy again resulted in clinical clearing in all five patients. The follow-up period for six patients who received long-term PUVA maintenance ranged from 1 1/2 to 3 1/2 years. During PUVA therapy, five of ten patients developed epithelial malignancies or premalignancies, and one patient developed a malignant fibrous histiocytoma. Most of these patients had received prior treatment with electron beam and topical nitrogen mustard. PMID:6453139
Abel, E A; Deneau, D G; Farber, E M; Price, N M; Hoppe, R T
Association of Randall's Plaques with Collagen Fibers and Membrane Vesicles
Background Idiopathic calcium oxalate (CaOx) kidney stones develop by deposition of CaOx crystals on Randall's plaques (RP). Mechanisms involved in RP formation are still unclear. Objective It is our hypotheses that RP formation is similar to vascular calcification involving components of extracellular matrix including membrane bound vesicles (MV) and collagen fibers. In order to verify our hypothesis we critically examined renal papillary tissue from stone patients. Methods 4 mm cold-cup biopies of renal papillae were performed on fifteen idiopathic stone patients undergoing PCNL. Tissue was immediately fixed and processed for analyses by various light and electron microscopic techniques. Results and Limitations Spherulitic CaP crystals, the hallmark of RP's, were seen in all samples examined. They were seen in interstitium as well as laminated basement membrane of tubular epithelia. Large crystalline deposits comprised of dark elongated strands mixed with spherulites. Strands showed banded patterns similar to collagen. Crystal deposits were surrounded by collagen fibers and membrane bound vesicles. Energy dispersive x-ray microanalyses (EDX) and electron diffraction identified the crystals as hydroxyapatite. The number of kidneys examined is small and urinary data was not available for all the patients. Conclusions Results presented here show that crystals in the Randall's plaques are associated with both the collagen as well as MV. Collagen fibers appeared calcified and vesicles contained crystals. We conclude that crystal deposition in renal papillae may have started with membrane vesicle induced nucleation and grew by addition of crystals on the periphery within a collagen framework.
Khan, Saeed R.; Rodriguez, Douglas E.; Gower, Laurie B.; Monga, Manoj
Performance of digital RGB reflectance color extraction for plaque lesion
NASA Astrophysics Data System (ADS)
Several clinical psoriasis lesion groups are been studied for digital RGB color features extraction. Previous works have used samples size that included all the outliers lying beyond the standard deviation factors from the peak histograms. This paper described the statistical performances of the RGB model with and without removing these outliers. Plaque lesion is experimented with other types of psoriasis. The statistical tests are compared with respect to three samples size; the original 90 samples, the first size reduction by removing outliers from 2 standard deviation distances (2SD) and the second size reduction by removing outliers from 1 standard deviation distance (1SD). Quantification of data images through the normal/direct and differential of the conventional reflectance method is considered. Results performances are concluded by observing the error plots with 95% confidence interval and findings of the inference T-tests applied. The statistical tests outcomes have shown that B component for conventional differential method can be used to distinctively classify plaque from the other psoriasis groups in consistent with the error plots finding with an improvement in p-value greater than 0.5.
Hashim, Hadzli; Taib, Mohd Nasir; Jailani, Rozita; Sulaiman, Saadiah; Baba, Roshidah
Correlation between Plaque Composition as assessed by Virtual Histology and C-reactive Protein
Background Previous studies have shown that coronary plaque composition plays a pivotal role in plaque instability, and imaging modalities and serum biomarkers have been investigated to identify vulnerable plaque. Virtual histology IVUS (VH-IVUS) characterizes plaque components as calcified, fibrotic, fibrofatty, or necrotic core. C-reactive protein (hsCRP) is an independent risk factor and a powerful predictor of future coronary events. However, a relationship between inflammatory response indicated by CRP and plaque characteristics in ACS patients remains not well established. Objective To determine, by using VH-IVUS, the relation between coronary plaque components and plasma high-sensitivity CRP levels in patients with acute coronary syndromes (ACS). Methods 52 patients with ACS were enrolled in this prospective study. Electrocardiographically-gated VH-IVUS were performed in the culprit lesion before PCI. Blood sample was drawn from all patients before the procedure and after 24 hours, and hs-CRP levels were determined. Results Mean age was 55.3±4.9 years, 76.9% were men and 30.9% had diabetes. Mean MLA was 3.9±1.3 mm2, and plaque burden was 69±11.3%, as assessed by IVUS. VH-IVUS analysis at the minimum luminal site identified plaque components: fibrotic (59.6±15.8%), fibrofatty (7.6±8.2%), dense calcium (12.1±9.2%) and necrotic core (20.7±12.7%). Plasma hs-CRP (mean 16.02±18.07 mg/L) did not correlate with necrotic core (r=-0.089, p = 0.53) and other plaque components. Conclusions In this prospective study with patients with ACS, the predominant components of the culprit plaque were fibrotic and necrotic core. Serum hs C-reactive protein levels did not correlate with plaque composition.
Siqueira, Dimytri Alexandre de Alvim; Sousa, Amanda Guerra Moraes R.; Costa Junior, Jose de Ribamar; da Costa, Ricardo Alves; Staico, Rodolfo; Tanajura, Luis Fernando Leite; Centemero, Marinella Patrizia; Feres, Fausto; Abizaid, Alexandre Antonio Cunha; Sousa, J. Eduardo Moraes R.
Optical and mechanical parameter detection of calcified plaque for laser angioplasty
NASA Astrophysics Data System (ADS)
Three potential guidance mechanisms for pulsed laser angioplasty were tested for their ability to discriminate between different tissue types. Holmium:YAG laser energy (wavelength=2.1 um, 100 mJ/pulse, 12.7 J/mm2 fluence) was delivered through a 100 um fiber into normal artery, fibrous plaque, and calcified plaque, as well as saline and blood. Plasma emission, mechanical fiber recoil, and acoustic shock wave were all measured during laser irradiation of these different substances. Plasma emission was detected by a photodiode at the proximal end of the fiber. Mechanical fiber recoil was detected using a phono cartridge mechanically coupled to the fiber 60 cm from the distal end. Acoustic sound waves were detected with a hydrophone in close proximity to the target site. The probability of generating plasma emission and the relative magnitudes (1-4) of the mechanical recoil and acoustic signal are as follows: Signal Blood Normal Aorta White Plaque Calcified Plaque plasma 0% 0% 0% 99% acoustic 4 1 1 4 recoil 1 2 2.5 4 A Fourier transform of the acoustic signal showed differences between blood, normal artery or non-calcified plaque, and calcified plaque. Mechanical recoil does not provide additional information. These techniques do not differentiate normal tissue from fibrous plaque but will discriminate calcified plaque from blood, normal artery, and non-calcified plaque. These techniques are relatively easy to implement and provide potentially useful feedback to guide laser ablation. Conclusion: The presence of plasma is a good indicator of calcified plaque; when used in conjunction with the acoustic signal it could indicate whether the fiber catheter is on calcified plaque, non-calcified tissue, or in blood.
Stetz, Mark L.; O'Brien, Kenneth M.; Scott, John J.; Baker, Glenn S.; Deckelbaum, Lawrence I.
Preliminary in vivo atherosclerotic carotid plaque characterization using the accumulated axial strain and relative lateral shift strain indices
NASA Astrophysics Data System (ADS)
In this paper, we explore two parameters or strain indices related to plaque deformation during the cardiac cycle, namely, the maximum accumulated axial strain in plaque and the relative lateral shifts between plaque and vessel wall under in vivo clinical ultrasound imaging conditions for possible identification of vulnerable plaque. These strain indices enable differentiation between calcified and lipidic plaque tissue utilizing a new perspective based on the stiffness and mobility of the plaque. In addition, they also provide the ability to distinguish between softer plaques that undergo large deformations during the cardiac cycle when compared to stiffer plaque tissue. Soft plaques that undergo large deformations over the cardiac cycle are more prone to rupture and to release micro-emboli into the cerebral bloodstream. The ability to identify vulnerable plaque, prone to rupture, would significantly enhance the clinical utility of this method for screening patients. We present preliminary in vivo results obtained from ultrasound radio frequency data collected over 16 atherosclerotic plaque patients before these patients undergo a carotid endarterectomy procedure. Our preliminary in vivo results indicate that the maximum accumulated axial strain over a cardiac cycle and the maximum relative lateral shift or displacement of the plaque are useful strain indices that provide differentiation between soft and calcified plaques.
Shi, Hairong; Mitchell, Carol C.; McCormick, Matthew; Kliewer, Mark A.; Dempsey, Robert J.; Varghese, Tomy
A negative correlation between human carotid atherosclerotic plaque progression and plaque wall stress: In vivo MRI-based 2D\\/3D FSI models
It is well accepted that atherosclerosis initiation and progression correlate positively with low and oscillating flow wall shear stresses (FSS). However, this mechanism cannot explain why advanced plaques continue to grow under elevated FSS conditions. In vivo magnetic resonance imaging (MRI)-based 2D\\/3D multi-component models with fluid–structure interactions (FSI, 3D only) for human carotid atherosclerotic plaques were introduced to quantify correlations
Dalin Tang; Chun Yang; Sayan Mondal; Fei Liu; Gador Canton; Thomas S. Hatsukami; Chun Yuan
Effect of Amine Fluoride\\/Stannous Fluoride-Containing Toothpaste and Mouthrinsings on Dental Plaque, Gingivitis, Plaque and Enamel F–– Accumulation
The aim of the study was to assess the effect of an amine fluoride\\/stannous fluoride toothpaste and mouthwash on dental plaque and gingivitis, plaque F–– accumulation, F–– content and acid solubility of dental enamel. Participants in the 12-week double-blind study were 92 schoolchildren, with a mean age of 12.4 years, randomly distributed to four groups: (1) AmF\\/SnF2 toothpaste, (2) placebo
J. Bánóczy; J. Szöke; P. Kertész; Zs. Tóth; P. Zimmermann; Z. Gintner
Enamel microhardness and fluoride uptake underneath fermenting and non-fermenting artificial plaque.
Washed cells of Streptococcus sanguis were used to form artificial plaque on the surface of bovine enamel and incubated underneath buffer solutions, initial pH 6, for 36 h at 37 degrees C. The decrease in the microhardness of the enamel surface under fermenting "plaque" could be prevented with fluoride. Enamel under a fermenting "plaque" took up significantly more (P less than 0.0u) fluoride than enamel under a non-fermenting "plaque" (initial F- in buffer: 10 parts/10(6)). The artificial plaque did not accumulate fluoride. Within fermenting "plaques/, the pH decreased significantly more without flouride (P less than 0.01) than with fluoride. Fluoride combined with sucrose more than negated the softening of the enamel caused by sucrose fermentation, i.e. it increased the hardness above the original values. The diffusion of fluoride through the fermenting artificial plaque was more rapid than through a non-fermenting plaque. These findings suggest that caries-conducive circumstances may promote fluoride uptake by enamel compared with non-caries-conducive circumstances. PMID:22924
Turtola, L O
Respiratory pathogens in dental plaque of hospitalized patients with chronic lung diseases
Bacterial cultivation studies have shown that dental plaque is a reservoir for respiratory pathogens in intensive care unit patients and in elderly who are debilitated, hospitalized or in a nursing home, placing them at risk of bacterial pneumonia. No information is available, however, concerning dental plaque as a reservoir of putative respiratory pathogens in hospitalized patients with chronic lung diseases.
Andreea C. Didilescu; Nils Skaug; Constantin Marica; Cristian Didilescu
Correlation of cholinergic abnormalities with senile plaques and mental test scores in senile dementia
Necropsy brain tissue from normal (control) patients and patients with depression and dementia was examined for activities of various cholinergic components, and these related to the degree of senile plaque formation and extent of intellectual impairment. Choline acetyltransferase and acetylcholinesterase activities decreased significantly as the mean plaque count rose, and in depressed and demented subjects the reduction in choline acetyltransferase
E K Perry; B E Tomlinson; G Blessed; K Bergmann; P H Gibson; R H Perry
Correlations between bacterial levels in autologous subgingival plaque and saliva of adult Sudanese
The aim of this study was to assess levels of oral bacteria and their correlations in paired samples of saliva and subgingival plaque in a population of adult Sudanese. Whole saliva and pooled subgingival plaque samples from six probing sites of one tooth in each jaw were obtained from 56 Sudanese adults (mean age 35.2NJ.9 years). Levels of 24 oral
Ismail A. Darout; Jasim M. Albandar; Nils Skaug
Immunohistochemical localization of 14.3.3 zeta protein in amyloid plaques in human spongiform encephalopathies.
The localization of 14.3.3 proteins was studied in different subtypes of brain amyloid plaques. We examined paraffin-embedded brain sections of sporadic MV2 Creutzfeldt-Jakob disease (sCJD) with Kuru plaques, sporadic VV2 CJD with plaque-like PrP(sc) (the abnornal form of prion protein) deposits, variant CJD (vCJD) with florid plaques, Gerstmann-Straüssler-Scheinker (GSS) with multicentric plaques and of Alzheimer's disease (AD) with senile plaques. Adjacent immunostaining revealed PrP(sc) and 14.3.3 zeta deposits in the same amyloid plaques in all cases of sporadic CJD and vCJD, whereas 14.3.3 zeta was not seen in amyloid plaques of GSS with A117V, P102L and D202N mutations. The same immunostaining method using anti-betaA4 and anti-14.3.3 zeta antibodies revealed no colocalization in patients with AD. Our data suggest that 14.3.3 zeta protein could interact either with PrP or with other components of PrP(sc) deposits in CJD. PMID:12557018
Richard, Marlčne; Biacabe, Anne-Gaëlle; Streichenberger, Nathalie; Ironside, James West; Mohr, Michel; Kopp, Nicolas; Perret-Liaudet, Armand
Studies on Plaque Variants of Coxsackievirus B5 by Burst Analyses.
National Technical Information Service (NTIS)
Propagation of coxsackievirus B5 on cell lines revealed two variants, one that yields small plaques and is stable and another that is large but variable in size. Multiple-burst studies on the large-plaque pool showed the existence of two different populat...
J. Konowalchuk J. I. Speirs
Compressive mechanical properties of atherosclerotic plaques--indentation test to characterise the local anisotropic behaviour.
Accurate material models and associated parameters of atherosclerotic plaques are crucial for reliable biomechanical plaque prediction models. These biomechanical models have the potential to increase our understanding of plaque progression and failure, possibly improving risk assessment of plaque rupture, which is the main cause of ischaemic strokes and myocardial infarction. However, experimental biomechanical data on atherosclerotic plaque tissue is scarce and shows a high variability. In addition, most of the biomechanical models assume isotropic behaviour of plaque tissue, which is a general over-simplification. This review discusses the past and the current literature that focus on mechanical properties of plaque derived from compression experiments, using unconfined compression, micro-indentation or nano-indentation. Results will be discussed and the techniques will be mutually compared. Thereafter, an in-house developed indentation method combined with an inverse finite element method is introduced, allowing analysis of the local anisotropic mechanical properties of atherosclerotic plaques. The advantages and limitations of this method will be evaluated and compared to other methods reported in literature. PMID:24480703
Chai, Chen-Ket; Speelman, Lambert; Oomens, Cees W J; Baaijens, Frank P T
High Zn content of Randall's plaque: A ?-X-ray fluorescence investigation
Kidney stone disease, or nephrolithiasis, is a common ailment. Among the different risk factors usually associated with nephrolithiasis are dehydration, metabolic defects (especially with regard to calcium and oxalate). The presence of a mineral deposit at the surface of the renal papilla (termed Randall's plaque) has all been recently underlined. Of note, Randall's plaque is made of the calcium phosphate,
Xavier Carpentier; Dominique Bazin; Christelle Combes; Aurélie Mazouyes; Stephan Rouzičre; Pierre Antoine Albouy; Eddy Foy; Michel Daudon
Dichotomy in Hedgehog Signaling between Human Healthy Vessel and Atherosclerotic Plaques
The major cause for plaque instability in atherosclerotic disease is neoangiogenic revascularization, but the factors controlling this process remain only partly understood. Hedgehog (HH) is a morphogen with important functions in revascularization, but its function in human healthy vessel biology as well as in atherosclerotic plaques has not been well investigated. Hence, we determined the status of HH pathway activity both in healthy vessels and atherosclerotic plaques. A series of 10 healthy organ donor–derived human vessels, 17 coronary atherosclerotic plaques and 24 atherosclerotic carotid plaques were investigated for HH pathway activity. We show that a healthy vessel is characterized by a high level of HH pathway activity but that atherosclerotic plaques are devoid of HH signaling despite the presence of HH ligand in these pathological structures. Thus, a dichotomy between healthy vessels and atherosclerotic plaques with respect to the activation status of the HH pathway exists, and it is tempting to suggest that downregulation of HH signaling contributes to long-term plaque stability.
Queiroz, Karla C S; Bijlsma, Maarten F; Tio, Rene A; Zeebregts, Clark J; Dunaeva, Marina; Ferreira, Carmen V; Fuhler, Gwenny M; Kuipers, Ernst J; Alves, Maria M; Rezaee, Farhad; Spek, C Arnold; Peppelenbosch, Maikel P
Ubiquitin immunoelectron microscopy of dystrophic neurites in cerebellar senile plaques of Alzheimer's disease
Senile plaques are present in the cerebellum of most Alzheimer patients. They are composed of beta-amyloid deposits lacking neurites detectable with immunocytochemistry for neurofilament, tau and paired helical filament proteins. Recent studies, however, have shown that cerebellar plaques usually contain round structures that are reactive with ubiquitin antibodies. In this immunoelectron microscopic study, the nature of these structures is explored.
D. W. Dickson; A. Wertkin; L. A. Mattiace; E. Fier; Y. Kress; P. Davies; S.-H. Yen
Proton-induced X-ray emission analysis of atherosclerotic plaques of the carotid bifurcation.
The trace elements of both calcified atherosclerotic plaques and plaque-free vessel walls of the carotid bifurcation from 31 autopsies were investigated using the proton-induced X-ray emission (PIXE) method. The trace elements studied were phosphorus (P), calcium (Ca), chrome (Cr), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), selenium (Se), bromine (Br), strontium (Sr), and rubidium (Rb). All samples contained Fe and Zn. Mercury (Hg) was not detected in any of the samples studied. All plaque-free samples contained Cu and almost all Br and Ca, none Sr. All calcified atherosclerotic plaques contained Ca and almost all Br and Sr. The relative levels of Ca were higher in the calcified plaques than in the plaque-free vessel walls. The relative value of Ca in calcified and uncalcified samples was greatest in the group who had died because of cardiovascular disorders and smallest in the group who had died from other causes. There was a strong positive correlation between the Ca and Sr of the plaque samples and between the P and Br of the plaque-free samples. PMID:1384615
Peltomaa, M; Mattila, K; Wolf, J; Hyvönen-Dabek, M
Effects of dental plaque antiseptic decontamination on bacterial colonization and nosocomial infections in critically ill patients
Objectives: To document in intensive care unit (ICU) patients the effect of dental plaque antiseptic decontamination on the occurrence of plaque colonization by aerobic nosocomial pathogens and nosocomial infections. Design: Single-blind randomized comparative study. Setting: A 16-bed adult intensive care unit in a university hospital. Patients: Patients consecutively admitted in the ICU with a medical condition suggesting an ICU stay
F. Fourrier; E. Cau-Pottier; H. Boutigny; M. Roussel-Delvallez; M. Jourdain; C. Chopin
Conditions for Formation of the Small-Plaque Phenotype of Chikungunya Virus.
National Technical Information Service (NTIS)
The natural background of cultivation was shown to influence the size of plaques formed by Chikungunya virus. The plaque size of S+ and S- mutants depended on the growth medium composition, components of the overlay, host cells, concentration of the cells...
G. D. Zasukhina V. P. Marinina
Metabolomic Effects of Xylitol and Fluoride on Plaque Biofilm in Vivo
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.
Takahashi, N.; Washio, J.
In vitro atherosclerotic plaque and calcium quantitation by intravascular ultrasound and electron-beam computed tomography
The purpose of this investigation was to compare the accuracy of intravascular ultrasound (IVUS) and electron-beam computed tomography (EBCT) in quantitating human atherosclerotic plaque and calcium. In experiment 1, 12 human atherosclerotic arterial segments were obtained at autopsy and imaged by using IVUS and EBCT. The plaque from each arterial segment was dissected and a volume measurement of the dissected
Dan E. Gutfinger; Cyril Y. Leung; Takafumi Hiro; Bavani Maheswaran; Shigeru Nakamura; Robert Detrano; Xingping Kang; Weiyi Tang; Jonathan M. Tobis
19F and 1H MRI detection of amyloid ? plaques in vivo
Formation of senile plaques composed of amyloid ? peptide, a pathological hallmark of Alzheimer disease, in human brains precedes disease onset by many years. Noninvasive detection of such plaques could be critical in presymptomatic diagnosis and could contribute to early preventive treatment strategies. Using amyloid precursor protein (APP) transgenic mice as a model of amyloid ? amyloidosis, we demonstrate here
Nobuhisa Iwata; Yukio Matsuba; Kumi Sato; Kazumi Sasamoto; Makoto Higuchi; Takaomi C Saido
Lysophosphatidic acid triggers mast cell-driven atherosclerotic plaque destabilization by increasing vascular inflammation[S
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.
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
Impact of enucleation versus plaque radiotherapy in the management of juxtapapillary choroidal melanoma on patient survival
The records of 265 consecutive patients with juxtapapillary choroidal melanoma were reviewed and a statistical non-randomised retrospective study was performed to evaluate the risk for metastasis and compare the survival rate of patients treated with plaque radiotherapy or enucleation. To obtain sufficient overlap between the enucleation and plaque radiotherapy, the statistical analysis was limited to an adjusted subgroup of 127
P De Potter; C L Shields; J A Shields; J R Cater; D J Tardio
[A new method for simultaneous demonstration of senile plaques and Alzheimer's neurofibrillary tangles].
The author completed the method according to Yamaguchi with a sodium hydroxide pretreatment, and he also modified the composition of the methenamine-silver nitrate solution. The Alzheimer cells as well as the classic (combined, neuritic) senile plaques and the diffuse plaques can be impregnated simultaneously with the new procedure. PMID:7826989
Krutsay, M
A negative correlation between human carotid atherosclerotic plaque progression and plaque wall stress: in vivo MRI-based 2D/3D FSI models.
It is well accepted that atherosclerosis initiation and progression correlate positively with low and oscillating flow wall shear stresses (FSS). However, this mechanism cannot explain why advanced plaques continue to grow under elevated FSS conditions. In vivo magnetic resonance imaging (MRI)-based 2D/3D multi-component models with fluid-structure interactions (FSI, 3D only) for human carotid atherosclerotic plaques were introduced to quantify correlations between plaque progression measured by wall thickness increase (WTI) and plaque wall (structure) stress (PWS) conditions. A histologically validated multi-contrast MRI protocol was used to acquire multi-year in vivo MRI images. Our results using 2D models (200-700 data points/patient) indicated that 18 out of 21 patients studied showed significant negative correlation between WTI and PWS at time 2 (T2). The 95% confidence interval for the Pearson correlation coefficient is (-0.443,-0.246), p<0.0001. Our 3D FSI model supported the 2D correlation results and further indicated that combining both plaque structure stress and flow shear stress gave better approximation results (PWS, T2: R(2)=0.279; FSS, T1: R(2)=0.276; combining both: R(2)=0.637). These pilot studies suggest that both lower PWS and lower FSS may contribute to continued plaque progression and should be taken into consideration in future investigations of diseases related to atherosclerosis. PMID:18191138
Tang, Dalin; Yang, Chun; Mondal, Sayan; Liu, Fei; Canton, Gador; Hatsukami, Thomas S; Yuan, Chun
Intracranial Plaque Enhancement in Patients with Cerebrovascular Events on High-Spatial-Resolution MR Images.
Purpose To characterize intracranial plaque inflammation in vivo by using three-dimensional (3D) high-spatial-resolution contrast material-enhanced black-blood (BB) magnetic resonance (MR) imaging and to investigate the relationship between intracranial plaque inflammation and cerebrovascular ischemic events. Materials and Methods The study was approved by the institutional review board and was HIPAA compliant. Twenty-seven patients (19 men; mean age, 56.8 years ± 12.4 [standard deviation]) with cerebrovascular ischemic events (acute stroke, n = 20; subacute stroke, n = 2; chronic stroke, n = 3; transient ischemic attack, n = 2) underwent 3D time-of-flight MR angiography and contrast-enhanced BB 3-T MR imaging for intracranial atherosclerotic disease. Each identified plaque was classified as either culprit (the only or most stenotic lesion upstream from a stroke), probably culprit (not the most stenotic lesion upstream from a stroke), or nonculprit (not within the vascular territory of a stroke). Plaque contrast enhancement was categorized on BB MR images (grade 0, enhancement less than or equal to that of normal arterial walls seen elsewhere; grade 1, enhancement greater than grade 0 but less than that of the pituitary infundibulum; grade 2, enhancement greater than or equal to that of the pituitary infundibulum), and degree of contrast enhancement was calculated. Associations of the likelihood of being a culprit lesion with both plaque contrast enhancement and plaque thickness were estimated with ordinal logistic regression. Results Seventy-eight plaques were identified in 20 patients with acute stroke (21 [27%] culprit, 12 [15%] probably culprit, and 45 [58%] nonculprit plaques). In these patients, grade 2 contrast enhancement was associated with culprit plaques (odds ratio 34.6; 95% confidence interval: 4.5, 266.5 compared with grade 0) when adjusted for plaque thickness. Grade 0 was observed in only nonculprit plaques. Culprit plaques had a higher degree of contrast enhancement than did nonculprit plaques (25.9% ± 13.4 vs 13.6% ± 12.3, P = .003). Conclusion Contrast enhancement of intracranial atherosclerotic plaque is associated with its likelihood to have caused a recent ischemic event and may serve as a marker of its stability, thereby providing important insight into stroke risk. © RSNA, 2014 Online supplemental material is available for this article. PMID:24475850
Qiao, Ye; Zeiler, Steven R; Mirbagheri, Saeedeh; Leigh, Richard; Urrutia, Victor; Wityk, Robert; Wasserman, Bruce A
Intraplaque Stretch in Carotid Atherosclerotic Plaque - an Effective Biomechanical Predictor for Subsequent Cerebrovascular Ischemic Events
Background Stretch is a mechanical parameter, which has been proposed previously to affect the biological activities in different tissues. This study explored its utility in determining plaque vulnerability. Methods One hundred and six patients with mild to moderate carotid stenosis were recruited in this study (53 symptomatic and 53 asymptomatic). High resolution, multi-sequence magnetic resonance (MR) imaging was performed to delineate various plaque components. Finite element method was used to predict high stretch concentration within the plaque. Results During a two-year follow-up, 11 patients in symptomatic group and 3 in asymptomatic group experienced recurrent cerebrovascular events. Plaque stretch at systole and stretch variation during one cardiac cycle was greater in symptomatic group than those in the asymptomatic. Within the symptomatic group, a similar trend was observed in patients with recurrent events compared to those without. Conclusion Plaques with high stretch concentration and large stretch variation are associated with increased risk of future cerebrovascular events.
Wang, Wenkai; Bahaei, Nasim S.; Chen, Shengyong; Young, Victoria E.; Graves, Martin J.; Gillard, Jonathan H.
Use of the plaque assay for testing the antibiotic susceptibility of intracellular bacteria.
The plaque assay was first described for titration of bacterial inoculums and clonal isolation, and was later adapted for testing antibiotics susceptibility and to study virulence factors and motility of bacteria. Over time, the sensitivity and reproducibility of the technique has been improved. Usually, the number of plaques is counted; however, the recent development of informatics tools has stimulated interest in the quantification of plaque size. Owing to this new approach, the plaque assay has been used to characterize the host cell response when infected cells are treated with antimicrobial agents. It was found that statins prevented cell lesions following rickettsial infection; in other studies, some antibiotics were found to cause apoptosis of host cells, suggesting a toxic activity. Here, we present an overview of the plaque assay as it has been used to investigate intracellular bacteria. PMID:24059920
Edouard, Sophie; Raoult, Didier
The efficacy of a herbal-based toothpaste on the control of plaque and gingivitis.
A double-blind controlled clinical trial with parallel groups was designed to investigate the effectiveness of a herbal-based toothpaste in the control of plaque and gingivitis as compared with a conventional dentifrice. 70 subjects with gingivitis completed the 6-week study. All participants had at least 20 natural teeth with no probing depths greater than 3 mm and a plaque index of 2 or more at baseline. At baseline, both groups were balanced for the parameters measured: plaque index, plaque vitality, gingival index, bleeding on probing and gingival crevicular fluid flow. At the end of the trial, there were reductions within both groups, however, there were no significant differences between the groups. It was concluded that the herbal based toothpaste was as effective as the conventionally formulated dentifrice in the control of plaque and gingivitis. PMID:7593698
Mullally, B H; James, J A; Coulter, W A; Linden, G J
Effect of Pomegranate Juice on Dental Plaque Microorganisms (Streptococci and Lactobacilli)
To study the effect of pomegranate juice on dental plaque microorganisms. A clinical trial was conducted on thirty healthy volunteers aged 25-30 years who visited Out Patient Department (OPD) of Bapuji Dental College and Hospital, Davangere during the month of October 2006. Before conducting the study, thorough oral prophylaxis was done and the subjects were asked to refrain from the oral hygiene procedures for 24 hrs. Dental plaque was collected from each subject, before and after rinsing 30ml of pomegranate juice without sugar. Plaque samples were cultured using Mitis Salivarius Agar and Rogosa SL Agar media. Wilcoxon's signed rank test was used for statistical analysis. Results showed that pomegranate rinse was effective against dental plaque microorganisms. There was a significant reduction in the number of colony forming units of streptococci (23%) and lactobacilli (46%). The ruby red seeds may be a possible alternative for the treatment of dental plaque bacteria.
Kote, Sowmya; Kote, Sunder; Nagesh, Lakshminarayan
Alzheimer-like plaque formation by human macrophages is reduced by fibrillation inhibitors and lovastatin.
The cerebral deposition of Abeta-peptide as amyloid fibrils and plaques represents a hallmark characteristic of Alzheimer's disease (AD). AD plaques are defined by their green birefringence after Congo red staining, their spherulite-like superstructure and their association with specific secondary components. Here we show that primary human macrophages promote the formation of amyloid plaques that correspond in all aforementioned characteristics to typical amyloid plaques from diseased tissues: they consist of aggregated Abeta-peptide, they reveal the typical ''Maltese cross" structure and they are associated with the secondary components glycosaminoglycanes, apolipoprotein E (apoE) and the raft lipids cholesterol and sphingomyelin. Plaque formation can be impaired in this cell system by addition of small molecules, such as Congo red, melantonine and lovastatin, suggesting potential applications for the study of cellular amyloid formation and for the identification or validation of drug candidates. PMID:16765377
Gellermann, Gerald P; Ullrich, Kathrin; Tannert, Astrid; Unger, Christiane; Habicht, Gernot; Sauter, Simon R N; Hortschansky, Peter; Horn, Uwe; Möllmann, Ute; Decker, Michael; Lehmann, Jochen; Fändrich, Marcus
Characterization of Porosity Distributions of Slurry-Coated and Dry-Powder Plaques Using Conductive Image Technique.
National Technical Information Service (NTIS)
The porosity distributions of sinter plaques manufactured by dry powder and wet slurry processes were measured using an improved conductive imaging microprobe. This study has indicated that the pore size distributions of dry-powder plaques are more unifor...
A. H. Phan, A. H. Zimmerman, M. V. Quinzio
Angioscopic Evaluation of Stabilizing Effects of Bezafibrate on Coronary Plaques in Patients With Coronary Artery Disease
Background Since long-term administrations of anti-hyperlipidemic agents result in reduction in % stenosis or increase in minimum lumen diameter (MLD) of stenotic coronary segments, it is generally believed that anti-hyperlipidemic agents stabilize vulnerable coronary plaques. However, recent pathologic and angioscopic studies revealed that vulnerability of coronary plaques is not related to severity of stenosis and the rims rather than top of the plaques disrupt, and therefore, angiography is not adequate for evaluation of vulnerability. Angioscopy enables macroscopic pathological evaluation of the coronary plaques. Therefore, we carried out a prospective angioscopic open trial for evaluation of the stabilizing effects of bezafibrate on coronary plaques. Methods From April, 1997 to December, 1998, 24 patients underwent coronary angioscopy of the plaques in the non-targeted vessels during coronary interventions and 6 months later. The patients were divided into control (10 patients, 14 plaques) and bezafibrat (14 patients, 21 plaques) groups. Oral administration of bezafibrate (Bezatol SR, 400mg/day) was started immediately after the interventions and was continued for 6 months. The vulnerability score was determined based on angioscopic characteristics of plaques and it was compared before and 6 months later. Results Six months later, vulnerability score was reduced (from 1.6 to 0.8;p < 0.05) in bezafibrate group and unchanged (from 1.4 to 1.3; NS) in control group. In bezafibrate group, the changes in vulnerability score was not correlated with those in % stenosis or MLD. Conclusion The results indicate that bezafibrate can stabilize coronary plaques.
Fujimori, Yoshiharu; Ohsawa, Hidefumi; Hirose, Jyunichi; Noike, Hirofumi; Tokuhiro, Keiichi; Kanai, Masahito; Yoshinuma, Masaki; Mineoka, Kazuhito; Hitsumoto, Takashi; Aoyagi, Kaneyuki; Sakurai, Takeshi; Sato, Shin; Yoshinaga, Kokushi; Ozegawa, Masaaki; Morio, Hiroshi; Yamada, Katsumi; Terasawa, Kimiko; Uchida, Yuuko; Oshima, Tomomitsu
Angioscopic evaluation of stabilizing effects of bezafibrate on coronary plaques in patients with coronary artery disease.
Background Since long-term administrations of anti-hyperlipidemic agents result in reduction in % stenosis or increase in minimum lumen diameter (MLD) of stenotic coronary segments, it is generally believed that anti-hyperlipidemic agents stabilize vulnerable coronary plaques. However, recent pathologic and angioscopic studies revealed that vulnerability of coronary plaques is not related to severity of stenosis and the rims rather than top of the plaques disrupt, and therefore, angiography is not adequate for evaluation of vulnerability.Angioscopy enables macroscopic pathological evaluation of the coronary plaques. Therefore, we carried out a prospective angioscopic open trial for evaluation of the stabilizing effects of bezafibrate on coronary plaques.Methods From April, 1997 to December, 1998, 24 patients underwent coronary angioscopy of the plaques in the non-targeted vessels during coronary interventions and 6 months later. The patients were divided into control (10 patients, 14 plaques) and bezafibrat (14 patients, 21 plaques) groups. Oral administration of bezafibrate (Bezatol SR, 400mg/day) was started immediately after the interventions and was continued for 6 months. The vulnerability score was determined based on angioscopic characteristics of plaques and it was compared before and 6 months later.Results Six months later, vulnerability score was reduced (from 1.6 to 0.8;p < 0.05) in bezafibrate group and unchanged (from 1.4 to 1.3; NS) in control group. In bezafibrate group, the changes in vulnerability score was not correlated with those in % stenosis or MLD. Conclusion The results indicate that bezafibrate can stabilize coronary plaques. PMID:18493543
Uchida, Y; Fujimori, Y; Ohsawa, H; Hirose, J; Noike, H; Tokuhiro, K; Kanai, M; Yoshinuma, M; Mineoka, K; Hitsumoto, T; Aoyagi, K; Sakurai, T; Sato, S; Yoshinaga, K; Ozegawa, M; Morio, H; Yamada, K; Terasawa, K; Uchida, Y; Oshima, T
Attenuating astrocyte activation accelerates plaque pathogenesis in APP/PS1 mice
The accumulation of aggregated amyloid-? (A?) 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 A? levels were unchanged, suggesting that the deletions had no effect on APP processing or A? 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.
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
Efficacy of essential oil mouthwash with and without alcohol: a 3-Day plaque accumulation model
Background The aim of this study was to evaluate the antiplaque effect of a new alcohol free essential oil mouthwash with respect to a control of an essential oil with alcohol mouthwash, using an in vivo plaque regrowth model of 3-days. Methods The study was designed as a double-masked, randomized, crossover clinical trial, involving 30 volunteers to compare two different essential oil containing mouthwashes, during a 3-day plaque accumulation model. After receiving a thorough professional prophylaxis at the baseline, over the next 3-days each volunteer refrained from all oral hygiene measures and had two daily rinses with 20 ml of the test mouthwash (alcohol free essential oil) or the control mouthwash (essential oil with alcohol). At the end of the each experimental period, plaque was assessed and the panelists filled out a questionnaire. Each subject underwent a 14 days washout period and there was a second allocation. Results The essential oil mouthwash with ethanol shows a better inhibitory effect of plaque regrowth in 3-days than the mouthwash test with only essential oil in the whole mouth (plaque index = 2.18 against 2.46, respectively, p < 0.05); for the lower jaw (plaque index = 2.28 against 2.57, respectively, p < 0.05); for the upper jaw (plaque index = 2.08 against 2.35, respectively, p < 0.05); for the incisors (plaque index = 1.93 against 2.27, respectively, p < 0.05); and the canines (plaque index = 1.99 against 2.47, respectively, p < 0.05). Conclusion The essential oil containing mouthwash without alcohol seems to have a less inhibiting effect on the plaque regrowth than the traditional alcoholic solution. Trial Registration ClinicalTrials.gov NCT01411618
The tar fraction of cigarette smoke does not promote arteriosclerotic plaque development.
In addition to being the single greatest known environmental cause of cancer, cigarette smoke (CS) is also a major contributor to heart disease. We reported previously that 1) inhalation of either mainstream or sidestream CS promotes aortic arteriosclerotic plaque development; 2) 1,3 butadiene, a vapor-phase component of CS, promotes plaque development at 20 ppm, which at the time was only 2 times higher than the threshold limit value; and 3) individual tar fraction carcinogens in CS, including polynuclear aromatic hydrocarbons (PAHs) and nitrosamines, either do not promote plaque development or do so only at high concentrations. These results suggested that the tar fraction is not the primary source of plaque-promoting agents in CS. We asked whether repeated exposure to the tar fraction of CS, collected in a cold trap (TAR), promotes plaque development in an avian model of arteriosclerosis. Acetone extracts of mainstream CS tar from burning, unfiltered reference cigarettes were solubilized in dimethyl sulfoxide (DMSO) and injected weekly into cockerels for 16 weeks (25 mg/kg/week). Positive controls were injected weekly with the synthetic PAH carcinogen, 7,12 dimethylbenz(a)anthracene (DMBA) dissolved in DMSO and negative controls were injected with DMSO. Plaque location and prevalence did not differ from group to group. Morphometric analysis of plaque cross-sectional areas showed that plaque sizes, which are log-normally distributed, were significantly larger in the DMBA cockerels compared to both the TAR and DMSO groups. There were no significant differences in plaque size between DMSO and TAR cockerels. The results reported here, combined with other recent findings, support the conclusion that the primary arteriosclerotic plaque-promoting components of CS are in the vapor phase. Images Figure 1. Figure 2.
Penn, A; Keller, K; Snyder, C; Nadas, A; Chen, L C
Vitamin K-Antagonists Accelerate Atherosclerotic Calcification and Induce a Vulnerable Plaque Phenotype
Background Vitamin K-antagonists (VKA) are treatment of choice and standard care for patients with venous thrombosis and thromboembolic risk. In experimental animal models as well as humans, VKA have been shown to promote medial elastocalcinosis. As vascular calcification is considered an independent risk factor for plaque instability, we here investigated the effect of VKA on coronary calcification in patients and on calcification of atherosclerotic plaques in the ApoE?/? model of atherosclerosis. Methodology/Principal Findings A total of 266 patients (133 VKA users and 133 gender and Framingham Risk Score matched non-VKA users) underwent 64-slice MDCT to assess the degree of coronary artery disease (CAD). VKA-users developed significantly more calcified coronary plaques as compared to non-VKA users. ApoE?/? mice (10 weeks) received a Western type diet (WTD) for 12 weeks, after which mice were fed a WTD supplemented with vitamin K1 (VK1, 1.5 mg/g) or vitamin K1 and warfarin (VK1&W; 1.5 mg/g & 3.0 mg/g) for 1 or 4 weeks, after which mice were sacrificed. Warfarin significantly increased frequency and extent of vascular calcification. Also, plaque calcification comprised microcalcification of the intimal layer. Furthermore, warfarin treatment decreased plaque expression of calcification regulatory protein carboxylated matrix Gla-protein, increased apoptosis and, surprisingly outward plaque remodeling, without affecting overall plaque burden. Conclusions/Significance VKA use is associated with coronary artery plaque calcification in patients with suspected CAD and causes changes in plaque morphology with features of plaque vulnerability in ApoE?/? mice. Our findings underscore the need for alternative anticoagulants that do not interfere with the vitamin K cycle.
Schurgers, Leon J.; Chatrou, Martijn L. L.; Herfs, Marjolein; Winkens, Mark H. M.; Westenfeld, Ralf; Veulemans, Verena; Krueger, Thilo; Shanahan, Catherine M.; Jahnen-Dechent, Willi; Biessen, Erik; Narula, Jagat; Vermeer, Cees; Hofstra, Leonard; Reutelingsperger, Chris P.
Plaque-Forming Cells in Rabbits Immunized with BCG Bacilli
Plaque-forming cells (PFC) in the regional lymph node, its efferent lymph, and the spleen of rabbits immunized with BCG were enumerated by localized hemolysis in gel, using sheep red blood cells coated with tuberculin protein. In the primary response, the maximal level of PFC production was reached at 5 days in the regional lymph node, and at 7 days in the spleen, whereas efferent lymphatic cells showed only a small number of PFC. Sharp peaks of PFC levels at 3 days were seen in the regional lymph node, spleen, and the efferent lymphatic cells in the secondary response. Blast cell outflow from the regional lymph node was maximal at 3 days in the secondary response as well as in the primary response. The relation between blast cell outflow and PFC production was discussed.
Okuyama, Harue; Morikawa, Kazuo
Topical therapies for the treatment of plaque psoriasis.
Psoriasis is a chronic inflammatory skin disease affecting approximately 2% of the US population. Plaque psoriasis, characterized by erythematous lesions covered with silvery scales, is the most common form. In the absence of a cure, long-term control is important for the management of this disease. Topical corticosteroids are the primary treatment strategy for most mild to moderate cases of psoriasis. For more severe cases, topical corticosteroids often are combined with other antipsoriatic agents to prolong the remission period between disease outbreaks, manage isolated flares during therapy, and ease the transition between therapies. With the availability of multiple formulations of topical antipsoriatic agents, including multiple formulations of topical corticosteroids with different potencies, physicians have a large number of treatment strategies for their patients with psoriasis. PMID:19916297
Bagel, Jerry
Calcium Oxalate Stones Are Frequently Found Attached to Randall's Plaque
The exact mechanisms of the crystallization processes that occur during the formation of calcium oxalate calculi are controversial. Over six decades ago, Alexander Randall reported on a series of cadaveric renal units in which he observed calcium salt deposits on the tips of the renal papilla. Randall hypothesized that these deposits, eponymously termed Randall's plaque, would be the ideal site for stone formation, and indeed in a number of specimens he noted small stones attached to the papillae. With the recent advent of digital endoscopic imaging and micro computerized tomography (CT) technology, it is now possible to inspect the renal papilla of living, human stone formers and to study the attached stone with greater scrutiny.
Matlaga, Brian R. [James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, 4940 Eastern Ave / Room A 345, Baltimore, Maryland 21224 (United States); Williams, James C. Jr.; Evan, Andrew P. [Departments of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Dr /MS 5035, Indianapolis, Indiana, 46202 (United States); Lingeman, James E. [Methodist Hospital Institute for Kidney Stone Disease, 1801 N. Senate Blvd, Suite 220, Indianapolis, Indiana, 46202 (United States)
Polyfluorinated bis-styrylbenzenes as amyloid-? plaque binding ligands.
Detection of cerebral ?-amyloid (A?) by targeted contrast agents remains of great interest to aid the in vivo diagnosis of Alzheimer's disease (AD). Bis-styrylbenzenes have been previously reported as potential A? imaging agents. To further explore their potency as (19)F MRI contrast agents we synthetized several novel fluorinated bis-styrylbenzenes and studied their fluorescent properties and amyloid-? binding characteristics. The compounds showed a high affinity for A? plaques on murine and human brain sections. Interestingly, competitive binding experiments demonstrated that they bound to a different binding site than chrysamine G. Despite their high logP values, many bis-styrylbenzenes were able to enter the brain and label murine amyloid in vivo. Unfortunately initial post-mortem (19)F NMR studies showed that these compounds as yet do not warrant further MRI studies due to the reduction of the (19)F signal in the environment of the brain. PMID:24657049
Nabuurs, Rob J A; Kapoerchan, Varsha V; Metaxas, Athanasios; de Jongh, Sanne; de Backer, Maaike; Welling, Mick M; Jiskoot, Wim; Windhorst, Albert D; Overkleeft, Hermen S; van Buchem, Mark A; Overhand, Mark; van der Weerd, Louise
Evaluating practice patterns for managing moderate to severe plaque psoriasis
Abstract Objective To describe practice patterns for care of Canadian patients with moderate to severe plaque psoriasis. Design Online survey of a consumer panel. Setting Participants were drawn from a population-wide Canadian consumer database. Participants To be eligible to participate, respondents had to have been diagnosed with plaque psoriasis within the past 5 years, and to have had body surface area involvement of 3% or greater in the past 5 years, or to have psoriasis on a sensitive area of the body (hands, feet, scalp, face, or genitals), or to be currently receiving treatment with systemic agents or phototherapy for psoriasis. Main outcome measures Proportion of respondents with psoriasis managed by FPs and other specialists, psoriasis therapies, comorbidities, and patient satisfaction. Results Invitations were sent to 3845 panelists with self-reported psoriasis, of which 514 qualified to complete the survey. Family physicians were reported to be the primary providers for diagnosis and ongoing care of psoriasis in all provinces except Quebec. Overall physician care was reported to be satisfactory by 62% of respondents. Most respondents receiving over-the-counter therapies (55%) or prescribed topical therapies (61%) reported that their psoriasis was managed by FPs. Respondents receiving prescription oral or injectable medications or phototherapy were mainly managed by dermatologists (42%, 74%, and 71% of respondents, respectively). Ongoing management of respondents with body surface area involvement of 10% or greater was mainly split between dermatologists (47%) and FPs (45%), compared with rheumatologists (4%) or other health care professionals (4%). Of those respondents receiving medications for concomitant health conditions, treatment for high blood pressure was most common (92%), followed by treatment for heart disease (75%) and elevated cholesterol and lipid levels (68%). Conclusion Patient-reported practice patterns for the diagnosis and management of moderate to severe psoriasis vary among provinces and in primary and secondary care settings.
Poulin, Yves; Wasel, Norman; Chan, Daphne; Bernstein, Geula; Andrew, Robin; Fraquelli, Elisa; Papp, Kim
Fluorescence characteristics of atherosclerotic plaque and malignant tumors
NASA Astrophysics Data System (ADS)
Two series of investigations utilizing laser-induced fluorescence (LIF) in characterizing diseased tissue are presented. In one in vitro investigation the fluorescence from normal and atherosclerotically diseased arteries are studied. In another clinical study the fluorescence in vivo from superficial urinary bladder malignancies in patients who had received a low-dose injection of Hematoporphyrin Derivative (HpD) is investigated. Additionally, the fluorescence properties of L-tryptophan, collagen-I powder, elastin powder, nicotinamide adenine dinucleotide and (beta) -carothene were investigated and compared with the spectra from the tissue samples. A nitrogen laser (337 nm) alone or in connection with a dye laser (405 nm) was used together with an optical multichannel analyzer (OMA) to study the fluorescence spectra. The fluorescence decay characteristics of atherosclerotic plaque were examined utilizing a mode locked argon ion laser, synchronously pumping a picosecond dye laser. A fast detection system based on photon counting was employed. The fluorescence decay curves were evaluated on a PC computer allowing up to three lifetime components to be determined. A fluorescence peak at 390 nm in fibrotic plaque was identified as due to collagen fibers, while a fluorescence peak at 520 nm was connected to (beta) -carotene. The in vivo measurements of urinary bladder malignancies were performed with the optical fiber of the OMA system inserted through the biopsy channel of a cystoscope during the diagnostical procedure. The spectral recordings from urinary bladders, obtained at 337 nm and 405 nm excitation, revealed fluorescence features which can be used to demarcate tumor areas from normal mucosa. The fluorescence emission might also be useful to characterize different degrees of dysplasia.
Andersson-Engels, Stefan; Baert, Luc; Berg, Roger; D'Hallewin, Marie-Ange; Johansson, Jonas; Stenram, Unne; Svanberg, Katarina; Svanberg, Sune
A Method for the Quantitative Site-Specific Study of the Biochemistry within Dental Plaque Biofilms Formed in vivo
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
C. Robinson; J. Kirkham; R. Percival; R. C. Shore; W. A. Bonass; S. J. Brookes; L. Kusa; H. Nakagaki; K. Kato; B. Nattress
The relation between carotid plaque echogenicity and oxidative stress marker 8-iso-prostaglandin F2?.
Echolucent plaques are associated with high risk of ischemic cerebrovascular events. Oxidative stress has been implicated in the process of atherosclerotic plaque development from initiation to progression. We assessed the relation between carotid plaque echogenicity and urinary 8-iso-prostaglandin F2?, as an index of oxidative stress. This cross-sectional study was conducted prospectively on 290 consecutive outpatients. Each patient was evaluated for carotid plaque echogenicity using the gray-scale median at the maximal thickness plaque and urinary 8-iso-prostaglandin F2? using enzyme linked immunosorbent assay. By Pearson correlation analysis, we found significant negative linear relation between gray-scale median values and the urinary 8-iso-prostaglandin F2? levels (r = -0.133, p = 0.023). This correlation remained significant after adjustment for atherosclerotic risk factors, thickness of the maximal plaque and medication use (? = -0.137, p = 0.031). We herein show that higher levels of urinary 8-iso-prostaglandin F2? is associated with lower plaque echogenicity. PMID:22261510
Nassar, Hoda; Furukado, Shigetaka; Tanaka, Makiko; Miwa, Kaori; Okazaki, Shuhei; Sakaguchi, Manabu; Mochizuki, Hideki; Kitagawa, Kazuo
MRI-based biomechanical imaging: initial study on early plaque progression and vessel remodeling
The goal of the study is to develop a noninvasive magnetic resonance imaging (MRI)-based biomechanical imaging technique to address biomechanical pathways of atherosclerotic progression and regression in vivo using a 3D fluid-structure interaction (FSI) model. Initial in vivo study was carried out in an early plaque model in pigs that underwent balloon-overstretch injury to the left carotid arteries. Consecutive MRI scans were performed while the pigs were maintained on high cholesterol (progression) or normal chow (regression), with an injection of a plaque-targeted contrast agent, Gadofluorine M. At the end of study, the specimens of carotid arterial segments were dissected and underwent dedicated mechanical testing to determine their material properties. 3D FSI computational model was applied to calculate structure stress and strain distribution. The plaque structure resembles early plaque with thickened intima. Lower maximal flow shear stress correlates with the growth of plaque volume during progression, but not during regression. In contrast, maximal principle structure stress/stain (stress-P1 and strain-P1) were shown to correlate strongly with the change in the plaque dimension during regression, but moderately during progression. This MRI-based biomechanical imaging method may allow for noninvasive dynamic assessment of local hemodynamic forces on the development of atherosclerotic plaques in vivo.
Zheng, Jie; Abendschein, Dana R.; Okamoto, Ruth J.; Yang, Deshan; McCommis, Kyle S.; Misselwitz, Bernd; Gropler, Robert J.; Tang, Dalin
Macrophage expression of active MMP-9 induces acute plaque disruption in apoE-deficient mice
The majority of acute clinical manifestations of atherosclerosis are due to the physical rupture of advanced atherosclerotic plaques. It has been hypothesized that macrophages play a key role in inducing plaque rupture by secreting proteases that destroy the extracellular matrix that provides physical strength to the fibrous cap. Despite reports detailing the expression of multiple proteases by macrophages in rupture-prone regions, there is no direct proof that macrophage-mediated matrix degradation can induce plaque rupture. We aimed to test this hypothesis by retrovirally overexpressing the candidate enzyme MMP-9 in macrophages of advanced atherosclerotic lesions of apoE–/– mice. Despite a greater than 10-fold increase in the expression of MMP-9 by macrophages, there was only a minor increase in the incidence of plaque fissuring. Subsequent analysis revealed that macrophages secrete MMP-9 predominantly as a proform, and this form is unable to degrade the matrix component elastin. Expression of an autoactivating form of MMP-9 in macrophages in vitro greatly enhances elastin degradation and induces significant plaque disruption when overexpressed by macrophages in advanced atherosclerotic lesions of apoE–/– mice in vivo. These data show that enhanced macrophage proteolytic activity can induce acute plaque disruption and highlight MMP-9 as a potential therapeutic target for stabilizing rupture-prone plaques.
Gough, Peter J.; Gomez, Ivan G.; Wille, Paul T.; Raines, Elaine W.
Genetic control of amyloid plaque production and incubation period in scrapie-infected mice.
The extent of amyloid plaque production was investigated in three inbred mouse strains carrying the p7 allele of the scrapie incubation (Sinc) gene (VM, IM and MB). With either ME7 or 87V scrapie, many more plaques were seen in the MB strain than in VM or IM mice. A backcrossing experiment using 87V suggested the involvement of more than one gene. Within this backcrossing experiment there was a positive correlation between mean plaque count and mean incubation period for the various strains and crosses. Also male mice tended to have higher plaque counts and longer incubation periods than female mice of the same genotype. These results suggest that some of the genes controlling minor variation in the incubation period also influence plaque production. This is consistent with previous evidence that the number of amyloid plaques depends, to some extent, on the duration of agent replication within the brain. This study has also identified a high plaque model (MB mice infected with 87V) for future investigation of the nature of the amyloid protein. PMID:3921669
Bruce, M E; Dickinson, A G
Aluminium and phosphate uptake by Phragmites australis: the role of Fe, Mn and Al root plaques.
Aluminium, a potentially phytotoxic metal, is an important constituent of many mine water discharges but has largely been neglected in the literature. The behaviour of this element in the rhizosphere of the wetland plant Phragmites australis was investigated in the laboratory in the presence and absence of Mn and Fe root plaques. Electron microscopy and chemical extraction techniques were utilized to determine the physico-chemical properties of the plaques and any association of Al. Both Mn and Fe plaques occurred as amorphous coatings on root surfaces with uneven distributions. Al was not adsorbed onto the surface of either plaque type but formed a separate phosphate deposit closely resembling the Fe and Mn plaques. Phosphorus was also found to be adsorbed to the surface of the Fe plaques (but not the Mn plaques). Both mechanisms were found to immobilize P at the root surface but this did not significantly reduce the concentration of P in aerial plant tissues that was sufficient to ensure adequate growth. PMID:12096805
Batty, Lesley C; Baker, Alan J M; Wheeler, Bryan D
Improving visualization of intracranial arteries at the skull base for CT angiography with calcified plaques
NASA Astrophysics Data System (ADS)
Bony structures at the skull base were the main obstacle to detection and estimation of arterial stenoses and aneurysms for CT angiography in the brain. Direct subtraction and the matched mask bone elimination (MMBE) have become two standard methods for removing bony structures. However, clinicians regularly find that calcified plaques at or near the carotid canal cannot be removed satisfactorily by existing methods. The blood-plaque boundary tends to be blurred by subtraction operation while plaque size is constantly overestimated by the bone mask dilation operation in the MMBE approach. In this study, we propose using the level of enhancement to adjust the MMBE bone mask more intelligently on the artery- and tissue-bone/plaque boundaries. The original MMBE method is only applied to the tissue-bone boundary voxels; while the artery-bone/blood-plaque boundary voxels, identified by a higher enhancement level, are processed by direct subtraction instead. A dataset of 6 patients (3 scanned with a regular dose and 3 scanned with a reduced dose) with calcified plaques at or near the skull base is used to examine our new method. Preliminary results indicate that the visualization of intracranial arteries with calcified plaques at the skull base can be improved effectively and efficiently.
Huang, Adam; Lee, Chung-Wei; Yang, Chung-Yi; Liu, Hon-Man
Helicobacter pylori in dental plaque and stomach of patients from Northern Brazil
AIM: To establish whether virulence factor genes vacA and cagA are present in Helicobacter pylori (H. pylori) retrieved from gastric mucosa and dental plaque in patients with dyspepsia. METHODS: Cumulative dental plaque specimens and gastric biopsies were submitted to histological examination, rapid urease test and polymerase chain reaction (PCR) assays to detect the presence of cagA and vacA polymorphisms. RESULTS: Detection of H. pylori from dental plaque and gastric biopsy samples was greater by PCR compared to histological examination and the rapid urease test. DNA from H. pylori was detected in 96% of gastric mucosa samples and in 72% of dental plaque samples. Sixty-three (89%) of 71 dental plaque samples that were H. pylori-positive also exhibited identical vacA and cagA genotypes in gastric mucosa. The most common genotype was vacAs1bm1 and cagA positive, either in dental plaque or gastric mucosa. These virulent H. pylori isolates were involved in the severity of clinical outcome. CONCLUSION: These pathogenic strains were found simultaneously in dental plaque and gastric mucosa, which suggests that gastric infection is correlated with the presence of H. pylori in the mouth.
Assumpcao, Monica Barauna; Martins, Luisa Caricio; Melo Barbosa, Hivana Patricia; dos Santos Barile, Katarine Antonia; de Almeida, Sintia Silva; Assumpcao, Paulo Pimentel; de Oliveira Corvelo, Tereza Cristina
Accuracy of Visible Plaque Identification by Pediatric Clinicians During Well-Child Care
Objectives Assess pediatric providers' ability to identify visible plaque on children's teeth. Methods Pediatric providers (residents, nurse practitioners, and attendings) conducting well-child care on 15-month to 5-year-olds in an academic practice examined children's maxillary incisors for visible plaque (recorded yes/no). A dental hygienist then examined the children and recorded the degree of visible plaque present. Results The children's mean age was 34 months (±15 months), and 50% had visible plaque. Providers (n = 28) identified visible plaque on 39% of children (n = 118), with 55% sensitivity and 80% specificity, and agreement with hygienist measured as a ? score was 0.34. Subgroup analyses (based on provider training level, exam experience, child age, and plaque scores) did not appreciably improve sensitivity, specificity, positive predictive value, negative predictive value, or ? scores. Conclusions Visible plaque exams performed during well-child care may not be accurate. To comply with caries-risk assessment guidelines, providers require further education in oral exams.
Dumas, S. Amanda; Weaver, Katelynn E.; Park, Seo Young; Polk, Deborah E.; Weyant, Robert J.; Bogen, Debra L.
Silence of NLRP3 Suppresses Atherosclerosis and Stabilizes Plaques in Apolipoprotein E-Deficient Mice
Objectives. The role of the NLRP3 inflammasome in atherosclerosis remains controversial. The aim of this study was to determine whether inhibition of NLRP3 signaling by lentivirus-mediated RNA interference could reduce atherosclerosis and stabilizes plaques. We also tried to explore the mechanisms of the impact of NLRP3 inflammasome on atherosclerosis. Methods. Apolipoprotein E-deficient mice aged 8 weeks were fed a high-fat diet and were injected with NLRP3 interfering or mock viral suspension after 4 weeks. Lentivirus transfer was repeated in 2 weeks. Four weeks after the first lentivirus injection, we evaluated the effects of NLRP3 gene silencing on plaque composition and stability and on cholesterol efflux and collagen metabolism, by histopathologic analyses and real-time PCR. Results. Gene silence of NLRP3 prevented plaques progression and inhibited inductions of proinflammatory cytokines. Moreover, this RNA interference reduced plaque content of macrophages and lipid, and increased plaque content of smooth muscle cells and collagen, leading to the stabilizing of atherosclerotic plaques. Conclusions. NLRP3 inflammasomes may play a vital role in atherosclerosis, and lentivirus-mediated NLRP3 silencing would be a new strategy to inhibit plaques progression and to reduce local inflammation.
Zheng, Fei; Xing, Shanshan; Gong, Zushun; Mu, Wei; Xing, Qichong
Candidate gene study revealed sex specific association between the OLR1 gene and carotid plaque
Background and Purpose Sex differences have been recognized in stroke risk; however, the sex-dependent genetic contribution to stroke is unclear. We sought to examine the sex-dependent associations between genes involved in lipid metabolism and carotid atherosclerotic plaque, a subclinical precursor of stroke. Methods For the Genetic Determinant of Subclinical Carotid Disease study, 287 Dominicans ascertained through the Northern Manhattan Study (NOMAS) were examined for carotid plaque using high-resolution ultrasound. Sixty-four single nucleotide polymorphisms (SNPs) in eleven lipid-related genes were genotyped. Plaque presence and plaque sub-phenotypes, including multiple, thick, irregular and calcified plaque, were analyzed. First, the interaction between each SNP and sex was evaluated for association with each plaque phenotype using multiple logistic regression and controlling for age, smoking, and the main effects of sex and SNP. For SNPs with suggestive evidence for interaction with sex (p<0.1 for the interaction term), stratification analysis by sex was performed to evaluate the sex-specific association between the SNP and plaque phenotypes. Results The most compelling finding is with the missense SNP rs11053646 (K167N) in the OLR1 gene, which encodes lectin-like oxidized LDL receptor. Stratification analysis revealed a strong association between rs11053646 and all plaque phenotypes in women (OR=2.44~5.86, p=0.0003~0.0081) but not in men (OR=0.85~1.22 p=0.77~0.92). Conclusions Genetic variation in genes involved in lipid metabolism may have sex-dependent effects on carotid plaque burden. Our findings provide a plausible biological basis underlying the sex difference in cardiovascular risk.
Wang, Liyong; Yanuck, Danielle; Beecham, Ashley; Gardener, Hannah; Slifer, Susan; Blanton, Susan H.; Sacco, Ralph L.; Rundek, Tatjana
The carotid plaque imaging in acute stroke (CAPIAS) study: protocol and initial baseline data
Background In up to 30% of patients with ischemic stroke no definite etiology can be established. A significant proportion of cryptogenic stroke cases may be due to non-stenosing atherosclerotic plaques or low grade carotid artery stenosis not fulfilling common criteria for atherothrombotic stroke. The aim of the CAPIAS study is to determine the frequency, characteristics, clinical and radiological long-term consequences of ipsilateral complicated American Heart Association lesion type VI (AHA-LT VI) carotid artery plaques in patients with cryptogenic stroke. Methods/Design 300 patients (age >49 years) with unilateral DWI-positive lesions in the anterior circulation and non- or moderately stenosing (<70% NASCET) internal carotid artery plaques will be enrolled in the prospective multicenter study CAPIAS. Carotid plaque characteristics will be determined by high-resolution black-blood carotid MRI at baseline and 12 month follow up. Primary outcome is the prevalence of complicated AHA-LT VI plaques in cryptogenic stroke patients ipsilateral to the ischemic stroke compared to the contralateral side and to patients with defined stroke etiology. Secondary outcomes include the association of AHA-LT VI plaques with the recurrence rates of ischemic events up to 36 months, rates of new ischemic lesions on cerebral MRI (including clinically silent lesions) after 12 months and the influence of specific AHA-LT VI plaque features on the progression of atherosclerotic disease burden, on specific infarct patterns, biomarkers and aortic arch plaques. Discussion CAPIAS will provide important insights into the role of non-stenosing carotid artery plaques in cryptogenic stroke. The results might have implications for our understanding of stroke mechanism, offer new diagnostic options and provide the basis for the planning of targeted interventional studies. Trial Registration NCT01284933
An Update of Animal Models of Alzheimer Disease with a Reevaluation of Plaque Depositions
Animal models of Alzheimer disease (AD) are used to study the mechanisms underlying AD pathogenesis, genetic interactions with genes of interest, and environmental risk factors that cause sporadic AD as well as to test the therapeutic effects of AD drug-candidates on neuropathology and cognitive function. To attain a comparative view on the AD models developed, representative AD lines were selected and summarized with respect to transgenic constructs and AD-related pathology. In addition, age-dependent plaque deposition data available in the literature for six representative AD models such as Tg2576, PDAPP, TgAPP23, Tg-APPswe/PS1dE9, 3xTg-AD, and 5XFAD mice were reevaluated using a photographic plaque reference scale method that was introduced recently. Tg2576, PDAPP, and TgAPP23 mice, which carry the amyloid precursor protein (APP) transgene, produced initially slow, but progressively accelerated plaque deposition as they aged, resulting in logistic plaque deposition. In contrast, Tg-APPswe/PS1dE9 and 3xTg-AD mice, which carry both APP and PS1 transgenes, developed abruptly accelerated plaque formation from the beginning, resulting in logarithmic plaque deposition. 5XFAD mice, which also carry both the APP and PS1 transgenes, developed a logarithmic deposition beginning at 2 months. This comparative analysis suggests that AD models may be classified into two distinct plaque deposition groups, and that early plaque models such as APPswe/PS1dE9, 3xTg-AD and 5XFAD might be useful to study the biochemical aspects of APP metabolism, whereas late plaque models such as Tg2576, PDAPP, and TgAPP23 might be useful to study more physiological and environmental aspects of AD pathogenesis, which occur on a longer time scale.
Lee, Jung-Eun
Influence of adsorption time, rocking, and soluble proteins on the plaque assay of monodispersed poliovirus.
Factors that could affect adsorption of monodispersed poliovirus to cell culture monolayers were evaluated. These included varying the virus adsorption period under static and nonstatic (rocked) conditions and altering the rocking rate. The effects of several soluble proteins on plaque formation, enumeration, and size were also evaluated. Rocking involved the mechanical spread of viruses over cell culture monolayers for 1 to 4 h. Rocked cultures exhibited significantly higher (P less than 0.05) plaque counts than corresponding static cultures. Optimal plaque counts were obtained after a 2-h adsorption period with rocking; increasing the period to 4 h did not significantly increase PFU. Optimal counts were not obtained until greater than or equal to 4 h with static adsorption. Plaque counts were not affected by increasing the rocking rate above one oscillation per minute, but a slower rocking rate resulted in a significant decrease in plaques. Adsorption of poliovirus in the presence of 3% solutions of beef and meat extracts, acid-precipitated oyster protein, two brands of skim milk, and 3 and 10% fetal bovine serum was compared with adsorption in protein-free controls. Significant reductions (P less than 0.05) in plaque counts occurred with one brand of skim milk, whereas 3% beef extract yielded highly significant reductions (P less than 0.01) in plaque counts and appreciable decreases in plaque sizes. Salinities of protein-containing virus inocula were high for beef and meat extracts but somewhat below physiological levels for the remaining inocula. Beef extract-associated reductions in PFU were eliminated after the extracts were dialyzed. Plaque reductions were associated with dialyzable components of the beef extract but not with the inoculum salinity. Images
Richards, G P; Weinheimer, D A
Significance of increased CIMT with coexisting carotid plaques in cerebral white matter lesions in elders.
It is very common that increased carotid intima media thickness (CIMT) and carotid plaque coexist in a single subject in elderly patients with white matter lesions (WMLs). In this study we investigated whether the coexistence of increased CIMT and carotid plaque is more strongly associated with the presence and extent of WMLs than either alone. All patients were classified into 1 of the following 4 groups: without either increased CIMT (I) or carotid plaque (P): I(-)P(-); with only increased CIMT: I(+)P(-); with only carotid plaque: I(-)P(+); and with both increased CIMT and carotid plaque: I(+)P(+). The presence and severity of periventricular WMLs (PWMLs) and deep WMLs (DWMLs) were assessed and the prevalence of MRI findings by the Cochran-Armitage trend test was calculated. The characteristics of subjects showed that the percentages of patients with increased CIMT and carotid plaque in the DWMLs group and the PWMLs group were significantly higher than those without WMLs group. Both DWMLs and PWMLs were strongly associated with age, carotid plaque and CIMT. Furthermore, the Cochran-Armitage trend test indicated that the prevalence of MRI findings of PWMLs and DWMLs increased in the order of I(-)P(-)< I(+)P(-)< I(-)P(+)< I(+)P(+) (P<0.0001). For the patients with DWMLs, the grades of both I(+)P(-) and I(+)P(+) were increased significantly compared to I(-)P(-) (P<0.0025, P<0.05, respectively) without such a difference found in patients with PWMLs. Our results suggested that the coexistence of increased CIMT and carotid plaque is most closely associated with WMLs, and that increased CIMT is associated with the severity of DWMLs, whereas carotid plaque is related to the presence of WMLs. PMID:23392710
Shu, Min; Zhang, Jun-jian; Dong, Yan; Zhang, Zai-peng
Methicillin-Resistant Staphylococcus aureus Phage Plaque Size Enhancement Using Sublethal Concentrations of Antibiotics
Phage therapy presents an alternative approach against the emerging methicillin-resistant Staphylococcus aureus (MRSA) threat. Some of the problems encountered during isolation of MRSA phages include the high prevalence of enteric phages in natural sources, nonspecific absorption of viable phage, and the formation of pinpoint or tiny plaques. The phage isolated in this study, MR-5, also formed tiny plaques against its host S. aureus ATCC 43300 (MRSA), making its detection and enumeration difficult. An improved method of increasing the plaque size of MRSA phage by incorporating sublethal concentrations of three different classes of antibiotics (inhibitors of protein synthesis) in the classical double-layer agar (DLA) method was investigated. The ?-lactam and quinolone antibiotics commonly employed in earlier studies for increasing the plaque size did not show any significant effect on the plaque size of isolated MR-5 phage. Linezolid (oxazolidinone class), tetracycline, and ketolide antibiotics brought significant enhancements (3 times the original size) in the plaque size of MR-5 phage. Prior treatment with these antibiotics resulted in significant reductions in the time of adsorption and the latent period of MR-5 phage. To rule out whether the action of linezolid (which brought the maximum increase in plaque size) was specific for a single phage only, its effect on the plaque size of seven other S. aureus-specific phages was also assessed. Significant enhancements in the plaque size of these phages were observed. These results indicate that this modification can therefore safely be incorporated in the traditional DLA overlay method to search for new MRSA-virulent phages.
Kaur, Sandeep; Harjai, Kusum
Leukotriene B4 Levels in Human Atherosclerotic Plaques and Abdominal Aortic Aneurysms
Background Leukotriene B4 (LTB4) has been associated with the initiation and progression of atherosclerosis and abdominal aortic aneurysm (AAA) formation. However, associations of LTB4 levels with tissue characteristics and adverse clinical outcome of advanced atherosclerosis and AAA are scarcely studied. We hypothesized that LTB4 levels are associated with a vulnerable plaque phenotype and adverse clinical outcome. Furthermore, that LTB4 levels are associated with inflammatory AAA and adverse clinical outcome. Methods Atherosclerotic plaques and AAA specimens were selected from two independent databases for LTB4 measurements. Plaques were isolated during carotid endarterectomy from asymptomatic (n?=?58) or symptomatic (n?=?317) patients, classified prior to surgery. LTB4 levels were measured without prior lipid extraction and levels were corrected for protein content. LTB4 levels were related to plaque phenotype, baseline patient characteristics and clinical outcome within three years following surgery. Seven non-diseased mammary artery specimens served as controls. AAA specimens were isolated during open repair, classified as elective (n?=?189), symptomatic (n?=?29) or ruptured (n?=?23). LTB4 levels were measured similar to the plaque measurements and were related to tissue characteristics, baseline patient characteristics and clinical outcome. Twenty-six non-diseased aortic specimens served as controls. Results LTB4 levels corrected for protein content were not significantly associated with histological characteristics specific for vulnerable plaques or inflammatory AAA as well as clinical presentation. Moreover, it could not predict secondary manifestations independently investigated in both databases. However, LTB4 levels were significantly lower in controls compared to plaque (p?=?0.025) or AAA (p?=?0.017). Conclusions LTB4 levels were not associated with a vulnerable plaque phenotype or inflammatory AAA or clinical presentation. This study does not provide supportive evidence for a role of LTB4 in atherosclerotic plaque destabilization or AAA expansion. However, these data should be interpreted with care, since LTB4 measurements were performed without prior lipid extractions.
van den Borne, Pleunie; van der Laan, Sander W.; Bovens, Sandra M.; Koole, Dave; Kowala, Mark C.; Michael, Laura F.; Schoneveld, Arjan H.; van de Weg, Sander M.; Velema, Evelyn; de Vries, Jean-Paul; de Borst, Gert J.; Moll, Frans L.; de Kleijn, Dominique P. V.; Quax, Paul H. A.; Hoefer, Imo E.; Pasterkamp, Gerard
Improving quality assurance for assembled COMS eye plaques using a pinhole gamma camera
A quality assurance system has been designed to verify the location and strength of seeds loaded in a brachytherapy eye plaque. This system consists of (1) a pinhole camera in conjunction with a Lumisys ACR-2000i computed radiography (CR) unit to image the location and measure the relative strength of the seeds with autoradiography, and (2) a source strength jig with a survey meter to estimate the total activity of the seeds in the plaque. Five holders of different sizes were made for fixation of the COMS (Collaborative Ocular Melanoma Study) plaques (12, 14, 16, 18, and 20 mm) in the camera. The plaque-to-pinhole distance (d{sub pp}) has been optimized to be 30 mm to give approximately uniform intensity on the CR image for uniformly loaded COMS plaques. The pinhole-to-detector distance (d{sub pd}) can be kept at either 30 mm for 1:1 scale, or at larger distances for higher magnification. For a 1:1 scaling and pinhole diameter of 0.345 mm, useful images are obtained with time-activity product (mCi sec) ranging from 5 to 250 mCi sec. Within this range, the pinhole system is able to differentiate seed activities of >10%. The resulting pinhole autoradiograph is able to (1) confirm the correct number of seeds loaded in the plaque, (2) verify the proper sitting of the seeds in the silastic carrier and the plaque, (3) verify the relative activity distribution of the seeds loaded in the plaque, and (4) potentially evaluate the integrity of the seed. The source strength measurement system is able to measure the total strength of seeds in the plaque ranging from 10 to 80 mCi with an uncertainty of 5%.
Beiki-Ardakani, Akbar; Jezioranski, John; Jaffray, David A.; Yeung, Ivan [Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada) and Departments of Radiation Oncology and Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)
Coronary artery atherectomy reduces plaque shear strains: An endovascular elastography imaging study.
Mechanical response and properties of the arterial wall can be used to identify the biomechanical instability of plaques and predict their vulnerability to rupture. Shear strain elastography (SSE) is proposed to identify vulnerable plaque features attributed to mechanical structural heterogeneities. The aims of this study were: 1) to report on the potential of SSE to identify atherosclerotic plaques; and 2) to use SSE maps to highlight biomechanical changes in lesion characteristics after directional coronary atherectomy (DCA) interventions. For this purpose, SSE was imaged using in vivo intravascular ultrasound (IVUS) radio-frequency data collected from 12 atherosclerotic patients before and after DCA intervention. Coronary atherosclerotic plaques (pre-DCA) showed high SSE magnitudes with large affected areas. There were good correlations between SSE levels and soft plaque content (i.e., cellular fibrosis, thrombosis and fibrin) (mean |SSE| vs. soft plaque content: r = 0.82, p < 0.01). Significant differences were noticed between SSE images before and after DCA. Stable arteries (post-DCA) exhibited lower values than pre-DCA vessels (e.g., pre-DCA: mean |SSE| = 3.9 ± 0.2% vs. 1.1 ± 0.2% post-DCA, p < 0.001). Furthermore, SSE magnitude was statistically higher in plaques with a high level of inflammation (e.g., mean |SSE| had values of 4.8 ± 0.4% in plaques with high inflammation, whereas it was reduced to 1.8 ± 0.2% with no inflammation, p < 0.01). This study demonstrates the potential of the IVUS-based SSE technique to detect vulnerable plaques in vivo. PMID:24835433
Keshavarz-Motamed, Zahra; Saijo, Yoshifumi; Majdouline, Younes; Riou, Laurent; Ohayon, Jacques; Cloutier, Guy
Ability of high-intensity ultrasound to ablate human atherosclerotic plaques and minimize debris size.
To investigate whether high-intensity ultrasound can destroy atherosclerotic plaques while sparing the normal arterial wall, 279 normal human aortic sites and 119 fibrous and 193 calcified plaques, obtained from 24 necropsies, were insonified in a water tank, at 20 kHz and at 5 different power intensities, ranging from 68 W/cm2 (P1) to 150 W/cm2 (P5). These intensities were associated with a total excursion of the ultrasound irradiation apparatus tip from 90 to 268 microns, respectively. Time to perforate normal aortic sites and fibrous and calcified plaques was recorded at each intensity. There was no difference in perforation time between normal aortic sites and fibrous and calcified plaques when high-power levels (P2 to P5) were used. However, at the lowest power (P1), perforation time for the normal aortic wall was significantly longer than for fibrous and calcified plaques: 30 +/- 18 seconds (166 observations), 14 +/- 7 seconds (p less than 0.001) (78 observations) and 12 +/- 8 seconds (p less than 0.001) (115 observations), respectively. When perforation times for normal vessel wall versus fibrous plaque and normal vessel wall versus calcified plaque from the same necropsy specimen were compared in a pairwise manner, the results were: 29 +/- 13 vs 16 +/- 7 (p less than 0.001) (48 paired observations) and 26 +/- 9 vs 10 +/- 5 seconds (p less than 0.001) (55 paired observations), respectively. Regardless of whether paired or unpaired comparison was applied, no significant difference was found in perforation time between fibrous and calcified plaques. The debris did not differ in size as measured separately for normal sites and fibrous and calcified plaques by a computer-interfaced Channelizer and Coulter Counter system.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2063787
Ernst, A; Schenk, E A; Gracewski, S M; Woodlock, T J; Murant, F G; Alliger, H; Meltzer, R S
The rhythmic expression of clock genes attenuated in human plaque-derived vascular smooth muscle cells
Background Acute myocardial infarction and stroke are more likely to occur in the early morning. Circadian pacemakers are considered to be involved in the process. Many peripheral tissues and cells also contain clock systems. In this study, we examined whether the primary cultured human plaque-derived vascular smooth muscle cells (VSMCs) process circadian rhythmicity; furthermore, we investigated the expression difference of clock genes between normal human carotid VSMCs and human plaque-derived VSMCs. Methods Fifty-six human carotid plaques provided the atherosclerotic tissue, and 21 samples yielded viable cultured primary VSMCs. The normal carotid VSMCs were cultured from donors' normal carotids. The mRNA levels of the target genes were measured by Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Results After serum shock, both types of cells showed clear circadian expressions of Bmal1, Cry1, Cry2, Per1, Per2, Per3 and Rev-erb? mRNA; meanwhile the Clock mRNA show a rhythmic expression in plaque-derived SMCs but not in normal carotid VSMCs. The expression levels of these main clock genes were significantly attenuated in human plaque-derived VSMCs compared with normal human carotid VSMCs. The rhythm of Bmal1 mRNA in plaque-derived VSMCs was changed. Conclusion The present results demonstrate that the human plaque-derived VSMCs possess different circadian rhythmicity from that of normal carotid VSMCs. The rhythm changes of clock genes in plaque-derived VSMCs may be involved in the process of atherosclerosis and finally promote the rupture of plaque.
Meshless Generalized Finite Difference Method and Human Carotid Atherosclerotic Plaque Progression Simulation Using Multi-Year MRI Patient-Tracking Data
Atherosclerotic plaque rupture and progression have been the focus of intensive investigations in recent years. Plaque rupture is closely related to most severe cardiovascular syndromes such as heart attack and stroke. A computational procedure based on meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating patients were scanned three times (T1, T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Since there was insufficient data with the current technology to quantify individual plaque component growth, the whole plaque was assumed to be uniform, homogeneous, hyperelastic, isotropic and nearly incompressible. The linear elastic model was used. The 2D plaque model was discretized and solved using a meshless generalized finite difference (GFD) method. Starting from the T2 plaque geometry, plaque progression was simulated by solving the solid model and adjusting wall thickness using plaque growth functions iteratively until T3 is reached. Numerically simulated plaque progression agreed very well with actual plaque geometry at T3 given by MRI data. We believe this is the first time plaque progression simulation based on multi-year patient-tracking data was reported. Serial MRI-based progression simulation adds time dimension to plaque vulnerability assessment and will improve prediction accuracy for potential plaque rupture risk.
Yang, Chun; Tang, Dalin; Yuan, Chun; Kerwin, William; Liu, Fei; Canton, Gador; Hatsukami, Thomas S.; Atluri, Satya
New method of antibody detection by indirect immunoperoxidase plaque staining for serodiagnosis of African swine fever.
An indirect immunoperoxidase plaque-staining method was developed for detecting antibody to African swine fever virus infection. In both sensitivity and specificity, the test was comparable to indirect immunofluorescence. Because it has all of the desirable features of the indirect immunofluorescence test and may also be readily used for testing large numbers of sera, the indirect immunoperoxidase plaque-staining method can be used as a single and final serodiagnostic test in a large-scale survey of African swine fever. The indirect immunoperoxidase plaque-staining method should be applicable to other viruses that can be adapted to and grown in cell cultures. Images
Pan, I C; Huang, T S; Hess, W R
Detection of plaque rupture using 64-slice multidetector row computed tomography
The present case report describes a 37-year-old man who presented to the emergency room with symptoms of a myocardial infarction but no high-grade stenosis on conventional catheter angiography. Consecutive multi-detector row computed tomography of the coronary arteries showed an intimal flap along a fibrous plaque formation in the left anterior descending artery. This finding was found to represent a plaque rupture, and the lesion was treated with an 18 mm stent. Multidetector row computed tomography helped to correctly position the stent by identifying the exact location of the rupture along the long plaque formation.
Reimann, Anja J; Beck, Torsten; Heuschmid, Martin; Brodoefel, Harald; Burgstahler, Christof; Schroder, Stephen; Kopp, Andreas F
Effect of Iron Plaque Formation on Phosphorus Accumulation and Availability in the Rhizosphere of Wetland Plants
Four wetland plants were selected to study the effect of Fe plaque formation on phosphorus (P) accumulation in the rhizosphere\\u000a and P uptake. There were significant positive correlations between the sorbed Fe content in the rhizosphere and the Fe plaque\\u000a concentration (r\\u000a 2?=?0.8454, p?r\\u000a 2?=?0.8460, p?0.01). The concentration of the Fe plaque on the root surface of four wetland plants
Defu Xu; Jianming Xu; Yan He; P. M. Huang
Plaque Formation in Tissue Cultures by Rickettsia rickettsi Isolated Directly from Whole Blood and Tick Hemolymph
A simple technique is described for isolation of Rickettsia rickettsi directly from tick hemolymph and whole blood of rickettsemic guinea pigs by means of the plaque assay technique in primary chicken embryo tissue cultures. Plaque-forming units per drop of hemolymph were almost 100-fold greater for partially engorged ticks than for unengorged ticks. Rickettsemia in guinea pigs fed upon by infected ticks was detected as early as 24 hr before fever. No morphological differences were noted between plaques formed by rickettsiae isolated from tick hemolymph or from whole guinea pig blood. Images
Wike, David A.; Burgdorfer, Willy
Plaque formation in tissue cultures by Rickettsia rickettsi isolated directly from whole blood and tick hemolymph.
A simple technique is described for isolation of Rickettsia rickettsi directly from tick hemolymph and whole blood of rickettsemic guinea pigs by means of the plaque assay technique in primary chicken embryo tissue cultures. Plaque-forming units per drop of hemolymph were almost 100-fold greater for partially engorged ticks than for unengorged ticks. Rickettsemia in guinea pigs fed upon by infected ticks was detected as early as 24 hr before fever. No morphological differences were noted between plaques formed by rickettsiae isolated from tick hemolymph or from whole guinea pig blood. PMID:4629203
Wike, D A; Burgdorfer, W
Multiple lentigines in areas of resolving psoriatic plaques after ustekinumab therapy.
The development of lentigines in areas previously involved by psoriasis has been reported in the literature, classically related to phototherapy but also to topical products. More recently, some authors have described several cases of lentigines appearing in resolving psoriatic plaques during or after treatment with anti-tumour necrosis factor (TNF) drugs used to treat severe plaque psoriasis, including adalimumab, etanercept, and infliximab. We report the case of a patient that developed multiple lentigines after clearance of the plaques of psoriasis receiving treatment with ustekinumab for his psoriasis. PMID:24746301
Guttierez-Gonzalez, E; Batalla, A; De la Mano, D
Biomechanical modeling and morphology analysis indicates plaque rupture due to mechanical failure unlikely in atherosclerosis-prone mice
Spontaneous plaque rupture in mouse models of atherosclerosis is controversial, although numerous studies have discussed so-called "vulnerable plaque" phenotypes in mice. We compared the morphology and biomechanics of two acute and one chronic murine model of atherosclerosis to human coronaries of the thin-cap fibroatheroma (TCFA) phenotype. Our acute models were apolipoprotein E-deficient (ApoE?/?) and LDL receptor-deficient (LDLr?/?) mice, both fed a high-fat diet for 8 wk with simultaneous infusion of angiotensin II (ANG II), and our chronic mouse model was the apolipoprotein E-deficient strain fed a regular chow diet for 1 yr. We found that the mouse plaques from all three models exhibited significant morphological differences from human TCFA plaques, including the plaque burden, plaque thickness, eccentricity, and amount of the vessel wall covered by lesion as well as significant differences in the relative composition of plaques. These morphological differences suggested that the distribution of solid mechanical stresses in the walls may differ as well. Using a finite-element analysis computational solid mechanics model, we computed the relative distribution of stresses in the walls of murine and human plaques and found that although human TCFA plaques have the highest stresses in the thin fibrous cap, murine lesions do not have such stress distributions. Instead, local maxima of stresses were on the media and adventitia, away from the plaque. Our results suggest that if plaque rupture is possible in mice, it may be driven by a different mechanism than mechanics.
Campbell, Ian C.; Weiss, Daiana; Suever, Jonathan D.; Virmani, Renu; Veneziani, Alessandro; Vito, Raymond P.; Oshinski, John N.
Biomechanical modeling and morphology analysis indicates plaque rupture due to mechanical failure unlikely in atherosclerosis-prone mice.
Spontaneous plaque rupture in mouse models of atherosclerosis is controversial, although numerous studies have discussed so-called "vulnerable plaque" phenotypes in mice. We compared the morphology and biomechanics of two acute and one chronic murine model of atherosclerosis to human coronaries of the thin-cap fibroatheroma (TCFA) phenotype. Our acute models were apolipoprotein E-deficient (ApoE(-/-)) and LDL receptor-deficient (LDLr(-/-)) mice, both fed a high-fat diet for 8 wk with simultaneous infusion of angiotensin II (ANG II), and our chronic mouse model was the apolipoprotein E-deficient strain fed a regular chow diet for 1 yr. We found that the mouse plaques from all three models exhibited significant morphological differences from human TCFA plaques, including the plaque burden, plaque thickness, eccentricity, and amount of the vessel wall covered by lesion as well as significant differences in the relative composition of plaques. These morphological differences suggested that the distribution of solid mechanical stresses in the walls may differ as well. Using a finite-element analysis computational solid mechanics model, we computed the relative distribution of stresses in the walls of murine and human plaques and found that although human TCFA plaques have the highest stresses in the thin fibrous cap, murine lesions do not have such stress distributions. Instead, local maxima of stresses were on the media and adventitia, away from the plaque. Our results suggest that if plaque rupture is possible in mice, it may be driven by a different mechanism than mechanics. PMID:23203971
Campbell, Ian C; Weiss, Daiana; Suever, Jonathan D; Virmani, Renu; Veneziani, Alessandro; Vito, Raymond P; Oshinski, John N; Taylor, W Robert
Imaging RAGE expression in atherosclerotic plaques in hyperlipidemic pigs
Background Receptor for advanced glycated end product (RAGE) expression is a prominent feature of atherosclerosis. We have previously shown in apoE null mice uptake of a radiolabeled anti-RAGE antibody in atherosclerotic plaque and now evaluate RAGE-directed imaging to identify advanced plaques in a large animal model. Methods Nine hyperlipidemic (HL) pigs were injected with 603.1?±?129.5 MBq of 99mTc-anti-RAGE F(ab?)2, and after 6 h (blood pool clearance), they underwent single-photon emission computed tomography/computed tomography (SPECT/CT) imaging of the neck, thorax, and hind limbs. Two HL pigs received 99mTc non-immune IgG F(ab?)2, and three farm pigs were injected with 99mTc-anti-RAGE F(ab?)2. After imaging, the pigs were euthanized. The aorta from the root to bifurcation was dissected, and the innominates, proximal carotids, and coronaries were dissected and counted, stained for H&E and RAGE, and AHA-classified. Results On pathology, 24% of the arterial segments showed AHA class III or IV lesions, and these lesions were confined almost exclusively to coronaries and carotids with % stenosis from 15% to 65%. Scatter plots of %ID/g for class III/IV vs. I/II lesions showed almost complete separation. Focal vascular uptake of tracer visualized on SPECT scans corresponded to class III/IV lesions in the coronary and carotid vessels. In addition, uptake in the hind limbs was noted in the HL pigs and corresponded to RAGE staining of small arteries in the muscle sections. Correlations for the vascular lesions were r?=?0.747, P?=?0.001 for %ID vs. %ID/g and r?=?0.83, P?=?0.002 for %ID/g vs. % RAGE staining. Conclusions Uptake of radiolabeled anti-RAGE antibody in coronary and carotid fibroatheroma and in the small arteries of the hind limbs in a relevant large animal model of atherosclerosis supports the important role of RAGE in atherosclerosis and peripheral artery disease as a target for imaging and treatment.
Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model
Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.
Khan, Niloufer [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States)] [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Singh, Arun D., E-mail: firstname.lastname@example.com [Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (United States)
Bilateral scaly plaques in axillae: pityriasis rosea of Vidal.
A 32-year-old man was referred for acute onset of pruritic scaly eruptions in the axillae of 8 days' duration, which was unresponsive to topical clotrimazole. The lesions consisted of multiple, coalescent oval plaques of 1 cm to 6 cm in longest diameter (Figure 1 and Figure 2) with central clearing and typical collarette scales at the periphery (Figure 3). Other skin areas and mucosal surfaces were unaffected. His general and systemic examinations were normal. Family and past histories were unremarkable except for a "ring worm-like patch" on his lower aspect of the abdomen 4 months ago, which rapidly regressed. On further inquiry, he gave a history of an episode of fever, coryza, and headache 3 weeks earlier to his eruption on the abdomen, which resolved with conservative remedies and one paracetamol tablet. He remained asymptomatic until axillary lesions appeared. We made a provisional diagnosis of pityriasis rosea (PR). Investigations including scrapings for potassium hydroxide examination, complete blood cell counts, urinalysis, blood sugar, VDRL test, and human immunodeficiency virus antibodies were all normal or non-reactive. As cutaneous biopsy revealed parakeratosis, epidermal spongiosis, dermal inflammatory cells, and extravasated red blood cells (Figure 4). The eruptions cleared within 8 days, following treatment with mometasone furoate cream and oral desloratidine 5 mg/d, leaving post-inflammatory hyperpigmentation. There was no recurrence for the next 6 months of observation. He was later lost to follow-up. PMID:23008948
Zawar, Vijay
Ultrasonography reveals nail thickening in patients with chronic plaque psoriasis.
Nail psoriasis is usually investigated and diagnosed by clinical examination. Ultrasonography is a non-invasive imaging technique for studying soft tissue involvement. The objective of this study was to estimate nail involvement in patients with chronic plaque psoriasis by ultrasonography. Prevalence, clinical type and severity of nail involvement according to nail psoriasis and severity index (NAPSI) were investigated in 138 patients with psoriasis. The thickness of the plate and bed of the fingernails was measured in 54 patients with psoriasis, 46 healthy controls and 37 patients with chronic eczema, using an ultrasonographic system equipped with a frequency transducer of 18 MHz. The prevalence of nail psoriasis was 73 % (102 out of 138). Onycholysis and thickening of the nail plate were the most common clinical type affecting 56 and 50 % of patients, respectively; splinter haemorrhages was the less common involving 10 % of patients. The mean NAPSI score was 18.4 ± 17.5 (SD; range 0-107). The thickness of fingernail plate and bed was significantly higher in patients with psoriasis with nail disease compared to healthy controls and patients with chronic eczema (p < 0.001). There was a linear correlation between NAPSI and plate and bed nail thickness (r = 0.52 and r = 0.38, p = 0.001). Increased nail plate and bed thickness was observed also in patients with psoriasis without clinically apparent nail involvement. In conclusion, thickening of the nail is a common feature of nail psoriasis also in patients without clinically apparent nail involvement. PMID:23011659
Gisondi, P; Idolazzi, L; Girolomoni, G
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
DETAIL OF ?BIVOUAC OF THE DEAD? PLAQUES, SOUTH OF CHAPEL/ADMINISTRATION BUILDING. VIEW TO NORTHEAST. - Los Angeles National Cemetery, 950 South Sepulveda Boulevard, Los Angeles, Los Angeles County, CA
Dietary supplementation with resveratrol reduces plaque pathology in a transgenic model of Alzheimer's Disease
Resveratrol, a polyphenol found in red wine, peanuts, soy beans, and pomegranates, possesses a wide range of biological effects. Since resveratrol's properties seem ideal for treating neurodegenerative diseases, its ability to diminish amyloid plaques was tested. Mice were fed clinically feasible dosages of resveratrol for forty-five days. Neither resveratrol nor its conjugated metabolites were detectable in brain. Nevertheless, resveratrol diminished plaque formation in a region specific manner. The largest reductions in the percent area occupied by plaques were observed in medial cortex (?48%), striatum (?89%) and hypothalamus (?90%). The changes occurred without detectable activation of SIRT-1 or alterations in APP processing. However, brain glutathione declined 21% and brain cysteine increased 54%. The increased cysteine and decreased glutathione may be linked to the diminished plaque formation. This study supports the concept that onset of neurodegenerative disease may be delayed or mitigated with use of dietary chemo-preventive agents that protect against ?-amyloid induced neuronal damage.
Karuppagounder, Saravanan S.; Pinto, John T.; Xu, Hui; Chen, Lian H.; Beal, M. Flint; Gibson, Gary E.
Improved chicken embryo cell culture plaque assay for scrub typhus rickettsiae.
The plaque technique for three strains of Rickettsia tsutsugamushi in chicken embryo cell cultures was greatly improved by modifying the trypsinizing procedure and employing homologous chicken serum in the overlay medium. Images
Woodman, D R; Grays, R; Weiss, E
Heart Disease without Coronary Plaque Buildup Linked to Heart Attack Risk
... RSS Email Alerts Follow @HeartNews Making News on Heart.org Learn More Heart disease without coronary plaque buildup linked to heart attack risk American Heart Association Meeting Report Abstract ...
Effects of Sanguinaria Extract on Plaque Retention and Gingival Health in Active Orthodontic Patients.
National Technical Information Service (NTIS)
Controlling plaque accumulation in orthodontic patients is of primary importance to all orthodontists. A new antiplane chemotherapeutic agent which contains sanguimaria extract was recently been introduced and proven to be effective in periodontal patient...
R. A. Miller
A fluorescence lifetime spectroscopy study of matrix metalloproteinases-2 and -9 in human atherosclerotic plaque.
Matrix metalloproteinase (MMP)-2 and -9 play important roles in the progression of atherosclerosis. This study aims to determine whether MMP-2 and -9 content in the fibrotic caps of atherosclerotic plaque is correlated with plaque autofluorescence. A time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) system was used to measure the autofluorescence and assess the biochemical composition of human plaques obtained from carotid endarterectomy. Results presented here demonstrate for the first time the ability to characterize the biochemical composition as it relates to MMP-2 and -9 content in the atherosclerotic plaque cap using a label-free imaging technique implemented with a fiberoptic TR-LIFS system. PMID:21770037
Phipps, Jennifer E; Hatami, Nisa; Galis, Zorina S; Baker, J Dennis; Fishbein, Michael C; Marcu, Laura
Non-healing verrucous plaque over upper limb for 1 year in a tea garden worker.
A 55-year-old tea garden worker presented with a slowly growing verrucous plaque on the right arm. The diagnosis of chromomycosis was confirmed by the identification of brown sclerotic bodies in a skin biopsy. PMID:23552009
Mandal, Rajesh Kumar; Banerjee, Sabyasachi; Kumar, Piyush; Chakrabarti, Indranil
Effect of Constant Diet on Microbial Populations of Human Dental Plaque.
National Technical Information Service (NTIS)
Constant diet, minimal oral hygiene, and simulated weightlessness appeared to have no statistically significant effect on selected microbial populations of human dental plaque. Subjects were eight airmen participating in a concurrently conducted bed rest ...
B. F. Podlin C. E. Brown C. J. Andres J. T. Cordaro
Senile Disciform Degeneration of the Macula. Retinal Arterialization of the Fibrous Plaque Demonstrated Clinically and Histopathologically.
National Technical Information Service (NTIS)
Retinal arterialization of a subretinal fibrous-tissue plaque has been observed clinically and by fluorescein angiography in three patients with senile disciform macular degeneration and one with presumed healed Toxocara chorioretinitis. This curious phen...
J. D. M. Gass W. R. Green
Caries Inducing Streptococci and Polysaccharide Forming Ability of Dental Plaque as Indicators of Caries Susceptibility.
National Technical Information Service (NTIS)
Evaluation of the null hypothesis that after having taken into account a number of epidemiological variables there are no differences in the relative frequencies of various 'caries inducing' micro-organisms and the sucrase activity of plaque in children a...
W. F. Liljemark J. I. Swenson
Using multimodal femtosecond CARS imaging to determine plaque burden in luminal atherosclerosis
NASA Astrophysics Data System (ADS)
Luminal atherosclerosis imaging was demonstrated by multimodal femtosecond CARS microscopy (MM-CARS). Using a myocardial infarction-prone rabbit model of atherosclerosis, this study demonstrated the utility of multimodal CARS imaging in determining atherosclerotic plaque burden through two types of image analysis procedures. Firstly, multimodal CARS images were evaluated using a signal-intensity parameter based on intensity changes derived from the multi-channel data (e.g. TPEF, SHG and CARS) to classify plaque burden within the vessel. Secondly, the SHG images that mainly correspond to collagen fibrils were evaluated using a texture analysis model based on the first-order statistical (FOS) parameters of the image histogram. Correlation between FOS parameters of collagen images with atherosclerosis plaque burden was established. A preliminary study of using spectroscopic CARS in identifying the different lipid components within the plaque was also discussed.
Ko, Alex C.-T.; Mostaço-Guidolin, Leila B.; Ridsdale, Andrew; Pegoraro, Adrian F.; Smith, Michael S. D.; Slepkov, Aaron; Hewko, Mark D.; Kohlenberg, Elicia K.; Schattka, Bernie; Stolow, Albert; Sowa, Michael G.
In vivo antimicrobial activity of an essential oil-containing mouthrinse on interproximal plaque bacteria.
This study determined the in vivo interproximal bactericidal efficacy of an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic) following toothbrushing. Thirty-four generally healthy adults, aged 23-64 years, completed this evaluator-blind, randomized, controlled, crossover designed study. Subjects rinsed for 30 seconds with 20 ml of either the essential oil rinse or a negative control rinse. Five minutes later, interproximal plaque was collected using paper points, and recoverable bacterial counts were quantified using both end point dilution and spectrophotometric methods. The results from the end point dilution demonstrated a statistically significant (p < 0.001) 43.8% reduction in recoverable plaque bacteria from interproximal spaces following rinsing with the essential oil mouthrinse. This study suggests that the clinical effectiveness of the essential oil mouthrinse against plaque and gingivitis may be attributable to the rapid kill and plaque permeabilizing properties of the formulation. PMID:11460278
Charles, C H; Pan, P C; Sturdivant, L; Vincent, J W
The effect of hexetidine spray on dental plaque following periodontal surgery.
The aim of the present study was to determine the effects of a 0.2% hexetidine spray, used as a supplement to regular oral hygiene measures, on dental plaque and gingival condition following periodontal surgery. This study was carried out on 38 patients who required 2 episodes of periodontal surgery. Examinations regarding dental plaque were performed at 0, 7, 14, 21 and 28 days, while the condition of the gingiva were examined at 0 and 28 days. Dental plaque was assessed by the Turesky modification of Quigley-Hein index; the gingival condition was evaluated using the gingival index of Löe-Silness and the papilla bleeding index. In a double-blind cross-over study of 28 days duration, significant reduction in plaque accumulation and an improvement in wound healing were demonstrated for the test spray compared to the placebo. PMID:8997651
Bokor, M
The structure and formation of the byssus attachment plaque in Mytilus.
The byssus attachment plaque and the tissues responsible for its formation were studied in M. californianus by light microscopy and by transmission and scanning electron microscopy. It was shown that the plaque consists of at least three phases which ultrastructurally resemble three secretions considered to be collagen, mucoid material and polyphenol. The mucoid and polyphenol appear to mix as a colloidal suspension in which the latter is the continuous phase and forms the definitive bonding surface. Plaque collagen represents an extension of thread material into the cementing substance. Stimulated secretion within the ducts and distal depression of the mussel's foot shows a continuum of increasing heterogeneity from the inner toward the outer regions. This reflects the distribution of exocrine cell apices wherein exocytosis of polyphenol granules predominate deeply, mucous granules superficially and collagen granules in between. It is proposed that the morphology of the plaque conforms to theoretical physical-chemical requirements for adhesion under water. PMID:933173
Tamarin, A; Lewis, P; Askey, J
Selective absorption of ultraviolet laser energy by human atherosclerotic plaque treated with tetracycline
Tetracycline is an antibiotic that absorbs ultraviolet light at 355 nm and preferentially binds to atherosclerotic plaque both in vitro and in vivo. Tetracycline-treated human cadaveric aorta was compared with untreated aorta using several techniques: absorptive spectrophotometry; and tissue uptake of radiolabeled tetracycline, which showed 4-fold greater uptake by atheroma than by normal vessel. In addition, intravenous tetracycline administered to patients undergoing vascular surgery demonstrated characteristic fluorescence in surgically excised diseased arteries. Because of tetracycline's unique properties, the authors exposed tetracycline-treated and untreated aorta to ultraviolet laser radiation at a wavelength of 355 nm. They found enhanced ablation of tetracycline-treated atheroma compared with untreated atheroma. The plaque ablation caused by ultraviolet laser radiation was twice as extensive in tetracycline-treated vs nontreated plaque. This study demonstrates the potential of tetracycline plaque enhancement for the selective destruction of atheroma by ultraviolet laser radiation.
Murphy-Chutorian, D.; Kosek, J.; Mok, W.; Quay, S.; Huestis, W.; Mehigan, J.; Profitt, D.; Ginsburg, R.
Multimodality optical imaging of atherosclerotic plaques combining optical coherence tomography and fluorescence lifetime imaging
We demonstrate the advantage of combining high-resolution Fourier domain optical coherence tomography (OCT) with wide-field time-gated fluorescence lifetime imaging microscopy (FLIM) for a comprehensive morphological and biochemical characterization of atherosclerotic vulnerable plaques (VP).
Javier A. Jo; Brian E. Applegate; Chintan A. Trivedi; Patrick Thomas; Desmond Jacob; Ryan Shelton; Fred Clubb; Brandis Keller
Plaque hemorrhage in carotid artery disease: Pathogenesis, clinical and biomechanical considerations
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.
Teng, Zhongzhao; Sadat, Umar; Brown, Adam J.; Gillard, Jonathan H.
Episcleral plaque 125I radiotherapy with episcleral LCF hyperthermia: A prospective randomized trial
PurposeThe purpose of this study was to search for an optimal radiation dose in the treatment of patients with uveal melanoma using 125I episcleral plaque radiotherapy (EPRT) and episcleral hyperthermia (HT).
Michael R Girvigian; Melvin A Astrahan; Jennifer I Lim; Alan L Murphree; Denice Tsao-Wei; Zbigniew Petrovich
New medium for isolation of Actinomyces viscosus and Actinomyces naeslundii from dental plaque.
Metronidazole (10 microgram/ml) and cadmium sulfate (20 microgram/ml) were added to a gelatin-based medium to select for microaerophilic Actinomyces species from dental plaque samples. The new medium (GMC), when incubated anaerobically, allowed 98% recovery of seven pure cultures of Actinomyces viscosus and 73% recovery of eight pure cultures of Actinomyces naeslundii, while suppressing 76% of the total count of other organisms in dental plaque samples. In 203 plaque samples, recoveries of A. viscosus and A. naeslundii on GMC and another selective medium for oral Actinomyces (CNAC-20) were compared. Recovery of A. viscosus was comparable on the two media. Recovery of A. naeslundii was significantly higher on GMC than CNAC-20 (P is less than 0.001), and GMC allowed a more characteristic cell morphology of both organisms. GMC medium appears to be useful for the isolation and presumptive identification of A. viscosus and A. naeslundii from dental plaque.
Kornman, K S; Loesche, W J
Iron plaque formation and morphoanatomy of roots from species of restinga subjected to excess iron.
The restingas, a sandy coastal plain ecosystem of Brazil, have received an additional amount of iron due to the activity of mining industries. The present study aims to characterize morphoanatomically and histochemically the iron plaque formation on roots of Ipomoea pes-caprae L. and Canavalia rosea DC, cultivated in hydroponic solution with and without excess iron. The iron plaque formation as well as changes in the external morphology of the lateral roots of both species were observed after the subjection to excess iron. Changes in the nutrient uptake, and in the organization and form of the pericycle and cortex cells were observed for both species. Scanning electron microscopy showed evident iron plaques on the whole surface of the root. The iron was histolocalized in all root tissues of both species. The species of restinga studied here formed iron plaque in their roots when exposed to excess of this element, which may compromise their development in environments polluted by particulated iron. PMID:22169228
Siqueira-Silva, Advanio Inácio; da Silva, Luzimar Campos; Azevedo, Aristéa Alves; Oliva, Marco Antonio
Influence of Modified Diets Upon the Quality and Quantity of Human Dental Plaque.
National Technical Information Service (NTIS)
The effects of dietary sucrose, as a component of a well characterized diet, on plaque quantity, its microbial and biochemical composition were determined under carefully supervised conditions in young healthy males and females. The study was composed of ...
Atheromatous Plaques of the Retinal Blood Vessels: Histologic Confirmation of Ophthalmoscopically Visible Lesions.
National Technical Information Service (NTIS)
Ophthalmoscopic examination of the left eye revealed numerous yellowish-white plaques involving the major branches of the central retinal artery in a 55-year-old man. Significant laboratory examinations demonstrated hyperlinidemia with hypercholesterolemi...
S. Brownstein, R. L. Font, M. G. Alper
Shape-based segmentation and visualization techniques for evaluation of atherosclerotic plaques in coronary artery disease
NASA Astrophysics Data System (ADS)
Multi-slice computed tomography (MSCT) has developed strongly in the emerging field of cardiovascular imaging. The manual analysis of atherosclerotic plaques in coronary arteries is a very time consuming and labor intensive process and today only qualitative analysis is possible. In this paper we present a new shape-based segmentation and visualization technique for quantitative analysis of atherosclerotic plaques in coronary artery disease. The new technique takes into account several aspects of the vascular anatomy. It uses two surface representations, one for the contrast filled vessel lumen and also one for the vascular wall. The deviation between these two surfaces is defined as plaque volume. These surface representations can be edited by the user manually. With this kind of representation it is possible to calculate sub plaque volumes (such as: lipid rich core, fibrous tissue, calcified tissue) inside this suspicious area. Also a high quality 3D visualization, using Open Inventor is possible.
Rinck, Daniel; Krüger, Sebastian; Reimann, Anja; Scheuering, Michael
Fluorinated Benzofuran Derivatives for PET Imaging of ?-Amyloid Plaques in Alzheimer's Disease Brains
A series of fluorinated benzofuran derivatives as potential tracers for positron emission tomography (PET) targeting ?-amyloid plaques in the brains of patients with Alzheimer's disease (AD) were synthesized and evaluated. The derivatives were produced using an intramolecular Wittig reaction. In experiments in vitro, all displayed high affinity for A?(1?42) aggregates with Ki values in the nanomolar range. Radiofluorinated 17, [18F]17, in particular labeled ?-amyloid plaques in sections of Tg2576 mouse brain and displayed high uptake (5.66% ID/g) at 10 min postinjection, sufficient for PET imaging. In addition, in vivo ?-amyloid plaque labeling can be clearly demonstrated with [18F]17 in Tg2576 mice. In conclusion, [18F]17 may be useful for detecting ?-amyloid plaques in patients with AD.
Painting blood vessels and atherosclerotic plaques with an adhesive drug depot
The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques.
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.
Painting blood vessels and atherosclerotic plaques with an adhesive drug depot.
The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques. PMID:23236189
Kastrup, Christian J; Nahrendorf, Matthias; Figueiredo, Jose Luiz; Lee, Haeshin; Kambhampati, Swetha; Lee, Timothy; Cho, Seung-Woo; Gorbatov, Rostic; Iwamoto, Yoshiko; Dang, Tram T; Dutta, Partha; Yeon, Ju Hun; Cheng, Hao; Pritchard, Christopher D; Vegas, Arturo J; Siegel, Cory D; MacDougall, Samantha; Okonkwo, Michael; Thai, Anh; Stone, James R; Coury, Arthur J; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G
Material-specific imaging of atherosclerotic plaque using coherently scattered x rays
NASA Astrophysics Data System (ADS)
The formation and development of plaques in the arterial wall is a direct consequence of atherosclerosis. The composition of a plaque is of particular interest as it is thought to be an important indicator of vulnerability, or risk of rupture and thrombosis. Current diagnostic methods do not yet have the ability to fully characterize plaque composition. Coherent-scatter imaging, a technique being developed in our laboratory, produces images based on the low-angle scattering properties of tissue. As these properties depend on molecular structure, material-specific maps of the different components in a tissue can be created. Material-specific images were produced for an atherosclerotic carotid artery. The image distributions of fatty and calcified deposits agreed with visual examination of the specimen. Preliminary results indicate that fat and calcifications, two typical plaque constituents, can be identified and distinguished from the undiseased vessel wall using coherently scattered x rays.
Davidson, Melanie T.; Batchelar, Deidre L.; Cunningham, Ian A.
The Improvement of Plaque Dispersing Enzymes as Oral Therapeutic Agents by Molecular Alteration.
National Technical Information Service (NTIS)
An oral therapeutic substance is formed by modifying a plaque-dispersing enzyme to control and reduce the occurrence of dental caries and periodontal diseases. In one embodiment, the modification is performed by introducing a suitable complexing reagent i...
L. G. Simonson B. C. Lamberts
Drinking Habits Are Associated with Changes in the Dental Plaque Microbial Community?
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 is noteworthy that the frequency of identification of anaerobes was significantly reduced when the frequencies for coffee and wine drinkers were compared with the frequencies for subjects in the control group. The DGGE profiles of the organisms in both plaque samples from all groups were generated and were used to construct dendrograms. A number of distinct clusters of organisms from water, coffee, and wine drinkers were formed. The clustering of some of the DGGE results into cohort-specific clusters implies similarities in the microbiotas within these groups and relevant differences in the microbiotas between cohorts. This supports the notion that the drinking habits of the subjects may influence the microbiota at both the supragingival and the subgingival levels.
Signoretto, Caterina; Bianchi, Franco; Burlacchini, Gloria; Sivieri, Francesca; Spratt, Dave; Canepari, Pietro
Association of the Sirtuin and Mitochondrial Uncoupling Protein Genes with Carotid Plaque
Objective Sirtuins (SIRTs) and mitochondrial uncoupling proteins (UCPs) have been implicated in cardiovascular diseases through the control of reactive oxygen species production. This study sought to investigate the association between genetic variants in the SIRT and UCP genes and carotid plaque. Methods In a group of 1018 stroke-free subjects from the Northern Manhattan Study with high-definition carotid ultrasonography and genotyping, we investigated the associations of 85 single nucleotide polymorphisms (SNPs) in the 11 SIRT and UCP genes with the presence and number of carotid plaques, and evaluated interactions of SNPs with sex, smoking, diabetes and hypertension as well as interactions between SNPs significantly associated with carotid plaque. Results Overall, 60% of subjects had carotid plaques. After adjustment for demographic and vascular risk factors, T-carriers of the SIRT6 SNP rs107251 had an increased risk for carotid plaque (odds ratio, OR?=?1.71, 95% CI?=?1.23–2.37, Bonferroni-corrected p?=?0.03) and for a number of plaques (rate ratio, RR?=?1.31, 1.18–1.45, Bonferroni-corrected p?=?1.4×10?5), whereas T-carriers of the UCP5 SNP rs5977238 had an decreased risk for carotid plaque (OR?=?0.49, 95% CI?=?0.32–0.74, Bonferroni-corrected p?=?0.02) and plaque number (RR?=?0.64, 95% CI?=?0.52–0.78, Bonferroni-corrected p?=?4.9×10?4). Some interactions with a nominal p?0.01 were found between sex and SNPs in the UCP1 and UCP3 gene; between smoking, diabetes, hypertension and SNPs in UCP5 and SIRT5; and between SNPs in the UCP5 gene and the UCP1, SIRT1, SIRT3, SIRT5, and SIRT6 genes in association with plaque phenotypes. Conclusion We observed significant associations between genetic variants in the SIRT6 and UCP5 genes and atherosclerotic plaque. We also found potential effect modifications by sex, smoking and vascular risk factors of the SIRT/UCP genes in the associations with atherosclerotic plaque. Further studies are needed to validate our observations.
Wang, Liyong; Cabral, Digna; Beecham, Ashley; McClendon, Mark S.; Luca, Corneliu C.; Blanton, Susan H.; Sacco, Ralph L.; Rundek, Tatjana
The relationship of amyloid plaques to cerebral capillaries in Alzheimer's disease.
The authors examined the hypothesis that senile plaques of Alzheimer's disease (AD) are formed by abnormal leakage of amyloidogenic precursors from brain capillaries by quantitative analysis of the spatial relationship between capillaries and amyloid plaques. Vibratome sections (40 mu) of the hippocampus, including the entorhinal cortex, obtained at autopsy from AD subjects, were immunostained with a monoclonal antibody to beta-protein and counterstained with rabbit serum to either the glucose transporter protein, a cerebral endothelial marker, or collagen type IV, a basal lamina marker. The authors found that while 60% to 77% of amyloid plaques were associated with capillaries, only 8% to 13% were penetrated by a capillary, the remainder being adjacent. To test whether 1) the area occupied by amyloid plaques or 2) the border zone (10-mu rim) surrounding amyloid plaques has a statistically higher density of capillaries than 3) the remaining gray matter, similarly double-stained 6-mu sections from five AD subjects were photographed and the capillary densities in the three areas calculated. Capillary density was significantly lower in 1) than in 3) and higher in 2) than in 3), while the combined area of 1) and 2) showed the same capillary density as 3). Similar results were obtained by using either the glucose transporter or the collagen type IV antibodies. Because capillary density is low within, and high in regions that immediately surround amyloid plaques, our findings suggest that amyloid plaques exclude capillaries or lead to their degeneration, or both. The latter possibility was investigated by triple-staining tissue sections with antibodies to beta-protein, glucose transporter, and collagen type IV. The proportion of glucose transporter-negative capillaries was not significantly different in areas inside or outside of the plaques. Thus, the authors found no evidence of basal lamina remnants consistent with capillary degeneration preferential to amyloid plaques. Although a small number of capillaries showed amyloid deposition just beneath the basement membrane, the authors conclude that capillaries play only a limited direct role, if any, in amyloid plaque formation, and that the apparent association of amyloid plaques and capillaries is no more than a chance contact. Images Figure 1 Figure 3
Kawai, M.; Kalaria, R. N.; Harik, S. I.; Perry, G.
Impact of flow rates in a cardiac cycle on correlations between advanced human carotid plaque progression and mechanical flow shear stress and plaque wall stress
Background Mechanical stresses are known to play important roles in atherosclerotic plaque initiation, progression and rupture. It has\\u000a been well-accepted that atherosclerosis initiation and early progression correlate negatively with flow wall shear stresses\\u000a (FSS). However, mechanisms governing advanced plaque progression are not well understood.\\u000a \\u000a \\u000a \\u000a \\u000a Method In vivo serial MRI data (patient follow-up) were acquired from 14 patients after informed consent. Each patient
Chun Yang; Gador Canton; Chun Yuan; Marina Ferguson; Thomas S Hatsukami; Dalin Tang
Inflammatory biomarkers in atherosclerosis: pentraxin 3 can become a novel marker of plaque vulnerability.
Inflammation is crucially involved in the development of carotid plaques. We examined the relationship between plaque vulnerability and inflammatory biomarkers using intraoperative blood and tissue specimens. We examined 58 patients with carotid stenosis. Following carotid plaque magnetic resonance imaging, 41 patients underwent carotid artery stenting (CAS) and 17 underwent carotid endarterectomy (CEA). Blood samples were obtained from the femoral artery (systemic) and common carotid artery immediately before and after CAS (local). Seventeen resected CEA tissue samples were embedded in paraffin, and histopathological and immunohistochemical analyses for IL-6, IL-10, E-selectin, adiponectin, and pentraxin 3 (PTX3) were performed. Serum levels of IL-6, IL-1?, IL-10, TNF?, E-selectin, VCAM-1, adiponectin, hs-CRP, and PTX3 were measured by multiplex bead array system and ELISA. CAS-treated patients were classified as stable plaques (n?=?21) and vulnerable plaques (n?=?20). The vulnerable group showed upregulation of the proinflammatory cytokines (IL-6 and TNF?), endothelial activation markers (E-selectin and VCAM-1), and inflammation markers (hs-CRP and PTX3) and downregulation of the anti-inflammatory markers (adiponectin and IL-10). PTX3 levels in both systemic and intracarotid samples before and after CAS were higher in the vulnerable group than in the stable group. Immunohistochemical analysis demonstrated that IL-6 was localized to inflammatory cells in the vulnerable plaques, and PTX3 was observed in the endothelial and perivascular cells. Our findings reveal that carotid plaque vulnerability is modulated by the upregulation and downregulation of proinflammatory and anti-inflammatory factors, respectively. PTX3 may thus be a potential predictive marker of plaque vulnerability. PMID:24936646
Shindo, Akihiro; Tanemura, Hiroshi; Yata, Kenichiro; Hamada, Kazuhide; Shibata, Masunari; Umeda, Yasuyuki; Asakura, Fumio; Toma, Naoki; Sakaida, Hiroshi; Fujisawa, Takao; Taki, Waro; Tomimoto, Hidekazu
Trypsin interaction with the senile plaques of Alzheimer disease is mediated by ?-protein precursor
In this study we demonstrate byin situ binding that trypsin interacts with the senile plaques found in Alzheimer disease. Characterization of various potential\\u000a trypsin binding proteins shows that trypsin binding is mediated by ?-protein precursor (?PP)—the progenitor of amyloid-? in\\u000a senile plaques. Using specific antisera against various proteins to sterically block trypsin blocking, we found that only\\u000a those antibodies raised
Mark A. Smith; Colleen E. Dunbar; Edward J. Miller; George Perry
Accuracy of MRI to Identify the Coronary Artery Plaque: A Comparative Study With Intravascular Ultrasound
Purpose To evaluate the ability of black-blood coronary arterial wall MRI to identify the coronary artery plaque, using intravascular ultrasound (IVUS) as the golden standard. Materials and Methods Nineteen consecutive patients underwent IVUS and coronary artery wall MRI. Cross-sectional images were acquired on the lesion of coronary artery from the ostium to the middle segment continuously. The vessel cross-sectional area (CSA), luminal CSA, plaque burden, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured in each slice which was then compared with the IVUS images. Results Sixteen of 19 patients completed coronary artery MRA and wall imaging. 41 of 67 slices were found plaques on both IVUS and MRI; The maximal wall thickness, plaque burden, SNR, CNR in the coronary wall containing plaque were greater compared with the normal coronary wall (1.70 ± 0.51 versus 1.24 ± 0.24; 0.71 ± 0.13 versus 0.59 ± 0.12; 1.86 ± 0.41 versus 1.47 ± 0.23; 5.10 ± 2.21 versus 2.99 ± 1.17; respectively, P < 0.05). The matched MRI and IVUS showed good correlation for vessel CSA (16.77 ± 10.67 versus 16.97 ± 8.36; r = 0.79; P < 0.01), luminal CSA (5.18 ± 5.01 versus 7.13 ± 5.14; r = 0.88; P < 0.01), plaque burden (0.71 ± 0.13 versus 0.59 ± 0.15; r = 0.67; P < 0.01). in segments containing plaques, especially the luminal CSA were strongly correlated. Conclusion MRI coronary artery wall imaging can identify coronary plaque in the proximal segments. It also has the potential to assess coronary artery size.
He, Yi; Zhang, Zhaoqi; Dai, Qinyi; Zhou, Yujie; Yang, Ya; Yu, Wei; An, Jing; Jin, Lixin; Jerecic, Renate; Yuan, Chun; Li, Debiao
Measurement of Color Parameters of Psoriatic Plaques by Narrow-Band Reflectance Spectrophotometry and Tristimulus Colorimetry
Color parameters were measured on 50 psoriatic plaques in 10 patients, after scoring the amount of scales on them by inspection, with a narrow-band reflectance spectrophotometer (erythema\\/melanin index expression) and tristimulus colorimeter (CIE L*a*b* expression). Both erythema index and a* (redness) were highest in the group of erythematous plaque with little scale (twice as high as in controls) and decreased
Hirotsugu Takiwaki; Jřrgen Serup
Effect of Manuka honey, chlorhexidine gluconate and xylitol on the clinical levels of dental plaque
Aims: To compare the effect of Manuka honey, chlorhexidine gluconate (0.2%) mouthwash and xylitol chewing gum on the dental plaque levels. Materials and Methods: Sixty healthy male dental students aged between 21 and 25 years (mean age 23.4 years) participated in the study. All the subjects received a professional prophylaxis at the start of the study, with the purpose of making the dentition 100% free of plaque and calculus. The subjects were then randomly divided into three groups, i.e. the Manuka honey group, the chlorhexidine gluconate mouthwash group and the xylitol chewing gum group. Rinsing with water or any other fluid after the procedure was not allowed as also any form of mechanical oral hygiene for all the subjects during the experimental period of 72 h. After the experimental period, the plaque was disclosed using disclosing solution and their scores were recorded at six sites per tooth using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Results: The mean plaque scores for Groups I, II and III were 1.37, 1.35 and 1.57, respectively. The ANOVA revealed that between-group comparison was significant, with an F-value of 5.99 and a probability value of 0.004. The T-test was carried out to evaluate the inter-group significance, which revealed that the plaque inhibition by Manuka honey was similar to that of chlorhexidine mouthwash. Both Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly, better than the xylitol chewing gum. Conclusion: Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly better than xylitol chewing gum.
Nayak, Prathibha A.; Nayak, Ullal A.; Mythili, R.
Novel MRI Contrast Agent for Molecular Imaging of Fibrin Implications for Detecting Vulnerable Plaques
Background—Molecular imaging of thrombus within fissures of vulnerable atherosclerotic plaques requires sensitive detection of a robust thrombus-specific contrast agent. In this study, we report the development and characterization of a novel ligand-targeted paramagnetic molecular imaging agent with high avidity for fibrin and the potential to sensitively detect active vulnerable plaques. Methods and Results—The nanoparticles were formulated with 2.5 to 50
Sebastian Flacke; Stefan Fischer; Michael J. Scott; Ralph J. Fuhrhop; John S. Allen; Mark McLean; Patrick Winter; Gregorio A. Sicard; Patrick J. Gaffney; Samuel A. Wickline; Gregory M. Lanza
Elevated White Blood Cell Count and Carotid Plaque Thickness The Northern Manhattan Stroke Study
Background and Purpose—Elevated leukocyte count has been associated with cardiovascular and cerebrovascular disease in several epidemiological studies. We sought to determine whether white blood cell count (WBC) is associated with carotid plaque thickness in a stroke-free, multiethnic cohort. Methods—For this cross-sectional analysis, WBC was measured in stroke-free community subjects undergoing carotid duplex Doppler ultrasound. Maximal internal carotid plaque thickness (MICPT)
Mitchell S. Elkind; Jianfeng Cheng; Bernadette Boden-Albala; Myunghee C. Paik; Ralph L. Sacco
Optical coherence tomography and its use in detection of vulnerable plaque
Acute coronary syndromes and their associated complications related to coronary ischemia continue to be the leading cause\\u000a of morbidity and mortality in the world. The most commonly encountered pathophysiologic cascade of events resulting in this\\u000a picture is initiated by formation of a vulnerable plaque. Despite the widespread use of a variety of imaging technologies,\\u000a high-resolution detection of the vulnerable plaque
Mehmet Cilingiroglu; Kerem Ozer
Genomewide Linkage and Peakwide Association Analyses of Carotid Plaque in Caribbean Hispanics
Background and Purpose Atherosclerosis is a complex subclinical cardiovascular disorder with a substantial genetic component. This study sought to identify genetic loci influencing carotid plaque in 2 independent samples. Methods B-mode ultrasound was performed to determine the presence and area of carotid plaque. Variance components analysis was used to test for linkage using 383 autosomal microsatellite markers in 1308 subjects from 100 Dominican families. Multiple linear and logistic regression models were used to investigate the association between plaque traits and 18 904 single nucleotide polymorphisms under the 1-logarithm of odds unit down regions of linkage peaks in an independent community-based data set (N=941, 41% Dominicans) from the Northern Manhattan Study. Results After adjustment for age, hypertension, diabetes mellitus, cigarette pack-years, body mass index, and waist-to-hip ratio, significant heritability was detected for plaque presence (h2=0.50±0.14, P<0.0001) and plaque area (h2=0.17±0.04, P<0.0001). Quantitative and dichotomous trait linkage analyses obtained similar results and identified 4 regions with multipoint logarithm of odds scores ?2.00 on 7q36, 11p15, 14q32, and 15q23. In the association analysis of the 4 linkage peaks, several single nucleotide polymorphisms in or near SOX6, FSD2, AP3S2, EFTUD1, and MYOD1 were associated with carotid plaque traits with a nominal P?0.0005 in the Northern Manhattan Study data set and with a P?0.01 in Northern Manhattan Study Dominican subset. Conclusions Carotid plaque has considerable heritability and may be influenced by loci on chromosomes 11p15, 14q32, and 15q23. The SOX6 gene within the bone morphogenic protein pathway could be a candidate for carotid plaque. Larger independent studies are needed to validate these findings.
Dong, Chuanhui; Beecham, Ashley; Slifer, Susan; Wang, Liyong; Blanton, Susan H.; Wright, Clinton B.; Rundek, Tatjana; Sacco, Ralph L.
Treatment with Angiotensin-(1-7) reduces inflammation in carotid atherosclerotic plaques.
Angiotensin (Ang)-(1-7), acting through the receptor Mas, has atheroprotective effects; however, its role on plaque vulnerability has been poorly studied. Here, we investigated the expression of the renin-angiotensin system (RAS) components in stable and unstable human carotid plaques. In addition, we evaluated the effects of the chronic treatment with an oral formulation of Ang-(1-7) in a mouse model of shear stress-determined carotid atherosclerotic plaque. Upstream and downstream regions of internal carotid plaques were obtained from a recently published cohort of patients asymptomatic or symptomatic for ischaemic stroke. Angiotensinogen and renin genes were strongly expressed in the entire cohort, indicating an intense intraplaque modulation of the RAS. Intraplaque expression of the Mas receptor mRNA was increased in the downstream portion of asymptomatic patients as compared to corresponding region in symptomatic patients. Conversely, AT1 receptor gene expression was not modified between asymptomatic and symptomatic patients. Treatment with Ang-(1-7) in ApoE-/- mice was associated with increased intraplaque collagen content in the aortic root and low shear stress-induced carotid plaques, and a decreased MMP-9 content and neutrophil and macrophage infiltration. These beneficial effects were not observed in the oscillatory shear stress-induced plaque. In vitro incubation with Ang-(1-7) did not affect ICAM-1 expression and apoptosis on cultured endothelial cells. In conclusion, Mas receptor is up regulated in the downstream portions of human stable carotid plaques as compared to unstable lesions. Treatment with the oral formulation of Ang-(1-7) enhances a more stable phenotype in atherosclerotic plaques, depending on the local pattern of shear stress forces. PMID:24499778
Fraga-Silva, Rodrigo A; Savergnini, Silvia Q; Montecucco, Fabrizio; Nencioni, Alessio; Caffa, Irene; Soncini, Debora; Costa-Fraga, Fabiana P; De Sousa, Frederico B; Sinisterra, Ruben D; Capettini, Luciano A S; Lenglet, Sébastien; Galan, Katia; Pelli, Graziano; Bertolotto, Maria; Pende, Aldo; Spinella, Giovanni; Pane, Bianca; Dallegri, Franco; Palombo, Domenico; Mach, François; Stergiopulos, Nikolaos; Santos, Robson A S; da Silva, Rafaela F
Peyronie's disease associated with increase in plasminogen activator inhibitor in fibrotic plaque
ObjectivesTo investigate whether tissue expression of plasminogen activator inhibitor type 1 (PAI-1) is increased in the fibrotic plaque of human Peyronie's disease (PD). Increased tissue levels of PAI-1, an inhibitor of both fibrinolysis and collagenolysis, have been found in a variety of fibrotic conditions. Recently, it was reported that PAI-1 expression was also increased in the fibrotic plaque of an
Hugo H. Davila; Thomas R. Magee; Freddi I. Zuniga; Jacob Rajfer; Nestor F. Gonzalez-Cadavid
Inflammatory Biomarkers in Atherosclerosis: Pentraxin 3 Can Become a Novel Marker of Plaque Vulnerability
Inflammation is crucially involved in the development of carotid plaques. We examined the relationship between plaque vulnerability and inflammatory biomarkers using intraoperative blood and tissue specimens. We examined 58 patients with carotid stenosis. Following carotid plaque magnetic resonance imaging, 41 patients underwent carotid artery stenting (CAS) and 17 underwent carotid endarterectomy (CEA). Blood samples were obtained from the femoral artery (systemic) and common carotid artery immediately before and after CAS (local). Seventeen resected CEA tissue samples were embedded in paraffin, and histopathological and immunohistochemical analyses for IL-6, IL-10, E-selectin, adiponectin, and pentraxin 3 (PTX3) were performed. Serum levels of IL-6, IL-1?, IL-10, TNF?, E-selectin, VCAM-1, adiponectin, hs-CRP, and PTX3 were measured by multiplex bead array system and ELISA. CAS-treated patients were classified as stable plaques (n?=?21) and vulnerable plaques (n?=?20). The vulnerable group showed upregulation of the proinflammatory cytokines (IL-6 and TNF?), endothelial activation markers (E-selectin and VCAM-1), and inflammation markers (hs-CRP and PTX3) and downregulation of the anti-inflammatory markers (adiponectin and IL-10). PTX3 levels in both systemic and intracarotid samples before and after CAS were higher in the vulnerable group than in the stable group. Immunohistochemical analysis demonstrated that IL-6 was localized to inflammatory cells in the vulnerable plaques, and PTX3 was observed in the endothelial and perivascular cells. Our findings reveal that carotid plaque vulnerability is modulated by the upregulation and downregulation of proinflammatory and anti-inflammatory factors, respectively. PTX3 may thus be a potential predictive marker of plaque vulnerability.
Shindo, Akihiro; Tanemura, Hiroshi; Yata, Kenichiro; Hamada, Kazuhide; Shibata, Masunari; Umeda, Yasuyuki; Asakura, Fumio; Toma, Naoki; Sakaida, Hiroshi; Fujisawa, Takao; Taki, Waro; Tomimoto, Hidekazu
Factors affecting iron plaque on the roots of Phragmites australis (Cav.) Trin. ex Steudel
Phragmites australis (the common reed) was collected at six sites in southern Qubec and Ontario, Canada, in order to study the accumulation of\\u000a iron plaque on the roots. The deposition of iron oxides on roots ofP. australis did not correlate directly with soil measurements; however, the amounts of iron-bound-to-carbonates fraction of the soil\\/sediment,\\u000a responsible for the iron plaque accumulation, correlated
L. St-Cyr; A. A. Crowder
Enhanced Expression of Lp-PLA2 and Lysophosphatidylcholine in Symptomatic Carotid Atherosclerotic Plaques
Background and Purpose—Circulating lipoprotein-associated phospholipase A2 (Lp-PLA2) has emerged as a novel biomarker for cardiovascular diseases. However, the correlation between the plaque expression of Lp-PLA2 and plaque oxidative stress, inflammation, and stability as well as the clinical presentation remains poorly defined, especially for cerebrovascular disease. Therefore, this study was performed to test the hypothesis that Lp-PLA2 expression is higher in
Dallit Mannheim; Joerg Herrmann; Daniele Versari; Mario Gossl; Fredric B. Meyer; Joseph P. McConnell; Lilach O. Lerman; Amir Lerman
Actinic comedonal plaque--a rare ectopic form of the Favre-Racouchot syndrome.
A 59-year-old woman with a single cuff-like plaque, consisting of multiple skin-coloured to bluish cysts and comedones on her right forearm is reported. The solitary lesion resembled, morphologically and histologically, the Favre-Racouchot syndrome. The above condition is another case of the previously described actinic comedonal plaque, which seems to be a rare entity within the spectrum of disease caused by actinic damage to the skin. PMID:8348720
John, S M; Hamm, H