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Sample records for plaque rupture current

  1. Fatigue crack propagation analysis of plaque rupture.

    PubMed

    Pei, Xuan; Wu, Baijian; Li, Zhi-Yong

    2013-10-01

    Rupture of atheromatous plaque is the major cause of stroke or heart attack. Considering that the cardiovascular system is a classic fatigue environment, plaque rupture was treated as a chronic fatigue crack growth process in this study. Fracture mechanics theory was introduced to describe the stress status at the crack tip and Paris' law was used to calculate the crack growth rate. The effect of anatomical variation of an idealized plaque cross-section model was investigated. The crack initiation was considered to be either at the maximum circumferential stress location or at any other possible locations around the lumen. Although the crack automatically initialized at the maximum circumferential stress location usually propagated faster than others, it was not necessarily the most critical location where the fatigue life reached its minimum. We found that the fatigue life was minimum for cracks initialized in the following three regions: the midcap zone, the shoulder zone, and the backside zone. The anatomical variation has a significant influence on the fatigue life. Either a decrease in cap thickness or an increase in lipid pool size resulted in a significant decrease in fatigue life. Comparing to the previously used stress analysis, this fatigue model provides some possible explanations of plaque rupture at a low stress level in a pulsatile cardiovascular environment, and the method proposed here may be useful for further investigation of the mechanism of plaque rupture based on in vivo patient data.

  2. Myocardial Bridge and Acute Plaque Rupture

    PubMed Central

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

    2016-01-01

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

  3. Multimodality Intravascular Imaging Assessment of Plaque Erosion versus Plaque Rupture in Patients with Acute Coronary Syndrome

    PubMed Central

    Kwon, Jee Eun; Mintz, Gary S.; Hong, Young Joon; Lee, Sung Yun; Kim, Ki Seok; Hahn, Joo-Yong; Kumar, Kaup Sharath; Won, Hoyoun; Hyeon, Seong Hyeop; Shin, Seung Yong; Lee, Kwang Je; Kim, Tae Ho; Kim, Chee Jeong; Kim, Sang Wook

    2016-01-01

    Background and Objectives We assessed plaque erosion of culprit lesions in patients with acute coronary syndrome in real world practice. Subjects and Methods Culprit lesion plaque rupture or plaque erosion was diagnosed with optical coherence tomography (OCT). Intravascular ultrasound (IVUS) was used to determine arterial remodeling. Positive remodeling was defined as a remodeling index (lesion/reference EEM [external elastic membrane area) >1.05. Results A total of 90 patients who had plaque rupture showing fibrous-cap discontinuity and ruptured cavity were enrolled. 36 patients showed definite OCT-plaque erosion, while 7 patients had probable OCT-plaque erosion. Overall, 26% (11/43) of definite/probable plaque erosion had non-ST elevation myocardial infarction (NSTEMI) while 35% (15/43) had ST elevation myocardial infarction (STEMI). Conversely, 14.5% (13/90) of plaque rupture had NSTEMI while 71% (64/90) had STEMI (p<0.0001). Among plaque erosion, white thrombus was seen in 55.8% (24/43) of patients and red thrombus in 27.9% (12/43) of patients. Compared to plaque erosion, plaque rupture more often showed positive remodeling (p=0.003) with a larger necrotic core area examined by virtual histology (VH)-IVUS, while negative remodeling was prominent in plaque erosion. Overall, 65% 28/43 of plaque erosions were located in the proximal 30 mm of a culprit vessel-similar to plaque ruptures (72%, 65/90, p=0.29). Conclusion Although most of plaque erosions show nearly normal coronary angiogram, modest plaque burden with negative remodeling and an uncommon fibroatheroma might be the nature of plaque erosion. Multimodality intravascular imaging with OCT and VH-IVUS showed fundamentally different pathoanatomic substrates underlying plaque rupture and erosion. PMID:27482258

  4. The roles of myeloperoxidase in coronary artery disease and its potential implication in plaque rupture.

    PubMed

    Teng, Nathaniel; Maghzal, Ghassan J; Talib, Jihan; Rashid, Imran; Lau, Antony K; Stocker, Roland

    2017-03-01

    Atherosclerosis is the main pathophysiological process underlying coronary artery disease (CAD). Acute complications of atherosclerosis, such as myocardial infarction, are caused by the rupture of vulnerable atherosclerotic plaques, which are characterized by thin, highly inflamed, and collagen-poor fibrous caps. Several lines of evidence mechanistically link the heme peroxidase myeloperoxidase (MPO), inflammation as well as acute and chronic manifestations of atherosclerosis. MPO and MPO-derived oxidants have been shown to contribute to the formation of foam cells, endothelial dysfunction and apoptosis, the activation of latent matrix metalloproteinases, and the expression of tissue factor that can promote the development of vulnerable plaque. As such, detection, quantification and imaging of MPO mass and activity have become useful in cardiac risk stratification, both for disease assessment and in the identification of patients at risk of plaque rupture. This review summarizes the current knowledge about the role of MPO in CAD with a focus on its possible roles in plaque rupture and recent advances to quantify and image MPO in plasma and atherosclerotic plaques.

  5. Changing views of the biomechanics of vulnerable plaque rupture: a review.

    PubMed

    Cardoso, Luis; Weinbaum, Sheldon

    2014-02-01

    This review examines changing perspectives on the biomechanics of vulnerable plaque rupture over the past 25 years from the first finite element analyses (FEA) showing that the presence of a lipid pool significantly increases the local tissue stress in the atheroma cap to the latest imaging and 3D FEA studies revealing numerous microcalcifications in the cap proper and a new paradigm for cap rupture. The first part of the review summarizes studies describing the role of the fibrous cap thickness, tissue properties, and lesion geometry as main determinants of the risk of rupture. Advantages and limitations of current imaging technologies for assessment of vulnerable plaques are also discussed. However, the basic paradoxes as to why ruptures frequently did not coincide with location of PCS and why caps >65 μm thickness could rupture at tissue stresses significantly below the 300 kPa critical threshold still remained unresolved. The second part of the review describes recent studies in the role of microcalcifications, their origin, shape, and clustering in explaining these unresolved issues including the actual mechanism of rupture due to the explosive growth of tiny voids (cavitation) in local regions of high stress concentration between closely spaced microinclusions oriented along their tensile axis.

  6. Optical measurement of arterial mechanical properties: from atherosclerotic plaque initiation to rupture

    PubMed Central

    2013-01-01

    Abstract. During the pathogenesis of coronary atherosclerosis, from lesion initiation to rupture, arterial mechanical properties are altered by a number of cellular, molecular, and hemodynamic processes. There is growing recognition that mechanical factors may actively drive vascular cell signaling and regulate atherosclerosis disease progression. In advanced plaques, the mechanical properties of the atheroma influence stress distributions in the fibrous cap and mediate plaque rupture resulting in acute coronary events. This review paper explores current optical technologies that provide information on the mechanical properties of arterial tissue to advance our understanding of the mechanical factors involved in atherosclerosis development leading to plaque rupture. The optical approaches discussed include optical microrheology and traction force microscopy that probe the mechanical behavior of single cell and extracellular matrix components, and intravascular imaging modalities including laser speckle rheology, optical coherence elastography, and polarization-sensitive optical coherence tomography to measure the mechanical properties of advanced coronary lesions. Given the wealth of information that these techniques can provide, optical imaging modalities are poised to play an increasingly significant role in elucidating the mechanical aspects of coronary atherosclerosis in the future. PMID:24296995

  7. Optical measurement of arterial mechanical properties: from atherosclerotic plaque initiation to rupture

    NASA Astrophysics Data System (ADS)

    Nadkarni, Seemantini K.

    2013-12-01

    During the pathogenesis of coronary atherosclerosis, from lesion initiation to rupture, arterial mechanical properties are altered by a number of cellular, molecular, and hemodynamic processes. There is growing recognition that mechanical factors may actively drive vascular cell signaling and regulate atherosclerosis disease progression. In advanced plaques, the mechanical properties of the atheroma influence stress distributions in the fibrous cap and mediate plaque rupture resulting in acute coronary events. This review paper explores current optical technologies that provide information on the mechanical properties of arterial tissue to advance our understanding of the mechanical factors involved in atherosclerosis development leading to plaque rupture. The optical approaches discussed include optical microrheology and traction force microscopy that probe the mechanical behavior of single cell and extracellular matrix components, and intravascular imaging modalities including laser speckle rheology, optical coherence elastography, and polarization-sensitive optical coherence tomography to measure the mechanical properties of advanced coronary lesions. Given the wealth of information that these techniques can provide, optical imaging modalities are poised to play an increasingly significant role in elucidating the mechanical aspects of coronary atherosclerosis in the future.

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

    PubMed Central

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

    2009-01-01

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

  9. Is Cadmium Exposure Associated with the Burden, Vulnerability and Rupture of Human Atherosclerotic Plaques?

    PubMed Central

    Sallsten, Gerd; Lundh, Thomas; Barregard, Lars

    2015-01-01

    The general population is exposed to cadmium from food and smoking. Cadmium is a widely spread toxic pollutant that seems to be associated with cardiovascular diseases, although little is known if it contributes to the occurrence of atherosclerotic plaques and the process whereby plaques become vulnerable and are prone to rupture. We tested the hypotheses that cadmium exposure is associated not only with an increased subclinical burden of atherosclerotic plaques in different vascular territories and early signs of plaque vulnerability, but also with cadmium content and plaque-rupture in the clinical phase of the disease. Ultrasound technique was used to measure plaque prevalence and echogenicity in the carotid and femoral arteries in a population sample of women (n = 599) in whom blood cadmium was measured. In addition cadmium was measured in snap-frozen endarterectomies and whole blood obtained from patients who were referred to surgery because of symptomatic carotid plaques (n = 37). Sixteen endarterectomies were divided into three parts corresponding to different flow conditions and plaque vulnerability. In the population sample blood cadmium was associated with the number of vascular territories with plaques (p = 0.003 after adjustment for potential confounders). The cadmium concentrations in symptomatic plaques were 50-fold higher in plaque tissue than in blood. Cadmium levels in blood and plaque correlated, also after adjustment for smoking and other cardiovascular risk factors (p<0.001). Compared with the other parts of the plaque, the cadmium content was double as high in the part where plaque rupture usually occurs. In conclusion, the results show that cadmium exposure is associated with the burden of subclinical atherosclerosis in middle-aged women with different degrees of glucose tolerance, and that the content of cadmium in symptomatic plaques in patients is related to that in blood, but much higher, and preferentially located in the part of plaque

  10. Effect of stent implantation on upstream coronary artery compliance--a cause of late plaque rupture?

    PubMed

    Ward, Michael R; Hibi, Kiyoshi; Shaw, James A; Furukawa, Eri; Resnic, Frederic S; Kimura, Kazuo

    2005-09-01

    Stent implantation in the rabbit aorta has been shown to increase vessel wall compliance at the inflow to the stent, but it is uncertain whether similar effects might be seen in the coronary arteries of humans and whether this would have any significant clinical consequences. First, we measured vessel compliance (systolic lumen area--diastolic lumen area/pulse pressure) before, immediately after, and at the 6-month follow-up visit at a site 5 mm upstream of the proximal edge of an implanted coronary stent in patients undergoing coronary intervention using motorized pull-back intravascular ultrasound recordings. Compliance in the upstream segment increased significantly immediately after stenting (before 7.13 +/- 1.49 vs after 10.73 +/- 1.36 mm2/mm Hg, p = 0.03), an effect that was unchanged at 6 months of follow-up (11.84 +/- 2.11 mm2/mm Hg, p = 0.08 vs before stenting). Second, we examined the site of plaque rupture in all patients presenting with an acute coronary syndrome in whom the culprit lesion was in a vessel that had had a stent implanted >12 months previously (n = 31). Plaque rupture was statistically more likely at the inflow to the stent (n = 22) than at other sites within the culprit vessel (n = 9, p <0.01). We conclude that stenting causes an increase in vessel compliance immediately proximal to the stent, and that when a vessel has been previously stented, plaque rupture is most likely to occur at the stent inflow site.

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

    PubMed Central

    2013-01-01

    Background Atherosclerotic plaque is subjected to a repetitive deformation due to arterial pulsatility during each cardiac cycle and damage may be accumulated over a time period causing fibrous cap (FC) fatigue, which may ultimately lead to rupture. In this study, we investigate the fatigue process in human carotid plaques using in vivo carotid magnetic resonance (MR) imaging. Method Twenty seven patients with atherosclerotic carotid artery disease were included in this study. Multi-sequence, high-resolution MR imaging was performed to depict the plaque structure. Twenty patients were found with ruptured FC or ulceration and 7 without. Modified Paris law was used to govern crack propagation and the propagation direction was perpendicular to the maximum principal stress at the element node located at the vulnerable site. Results The predicted crack initiations from 20 patients with FC defect all matched with the locations of the in vivo observed FC defect. Crack length increased rapidly with numerical steps. The natural logarithm of fatigue life decreased linearly with the local FC thickness (R2 = 0.67). Plaques (n=7) without FC defect had a longer fatigue life compared with those with FC defect (p = 0.03). Conclusion Fatigue process seems to explain the development of cracks in FC, which ultimately lead to plaque rupture. PMID:23617791

  12. The vulnerable plaque: current concepts and future perspectives on coronary morphology, composition and wall stress imaging.

    PubMed

    Silva Marques, João; Pinto, Fausto J

    2014-02-01

    Cardiovascular imaging plays an important role in the identification and characterization of the vulnerable plaque. A major goal is the ability to identify individuals at risk of plaque rupture and developing an acute coronary syndrome. Early recognition of rupture-prone atherosclerotic plaques may lead to the development of pharmacologic and interventional strategies to reduce acute coronary events. We review state-of-the-art cardiovascular imaging for identification of the vulnerable plaque. There is ample evidence of a close relationship between plaque morphology and patient outcome, but molecular imaging can add significant information on tissue characterization, inflammation and subclinical thrombosis. Additionally, identifying arterial wall exposed to high shear stress may further identify rupture-prone arterial segments. These new modalities may help reduce the individual, social and economic burden of cardiovascular disease.

  13. Plaque regression and plaque stabilisation in cardiovascular diseases

    PubMed Central

    Dave, Tarun; Ezhilan, J.; Vasnawala, Hardik; Somani, Vinod

    2013-01-01

    Atherosclerosis is characterized by formation of plaques on the inner walls of arteries that threatens to become the leading cause of death worldwide via its sequelae of myocardial infarction and stroke. Endothelial dysfunction leads to cholesterol uptake and accumulation of inflammatory markers within the plaque. The stability of a plaque eventually depends on the balance between vascular smooth muscle cells that stabilize it and the inflammatory cells like macrophages and T lymphocytes that make it prone to rupture. The current approach to manage atherosclerosis focuses on the treatment of a ruptured plaque and efforts have been made to reduce the risk of plaque rupture by identifying vulnerable plaques and treating them before they precipitate into clinical events. New diagnostic approaches such as IVUS and CIMT ultrasound are now being preferred over traditional coronary angiography because of their better accuracy in measuring plaque volume rather than the level of stenosis caused. The present review highlights the literature available on two prevalent approaches to manage a vulnerable plaque, namely, plaque stabilization and plaque regression, and their validation through various treatment modalities in recent plaque management studies. Plaque stabilization focuses on stabilizing the content of plaque and strengthening the overlying endothelium, while plaque regression focuses on the overall reduction in plaque volume and to reverse the arterial endothelium to its normal functional state. Although earlier studies contemplated the practicality of plaque regression and focused greatly on stabilization of a vulnerable plaque, our review indicated that, aided by the use of superior diagnostics tools, more intensive lipid modifying therapies have resulted in actual plaque regression. PMID:24381872

  14. Cholesterol-independent effects of atorvastatin prevent cardiovascular morbidity and mortality in a mouse model of atherosclerotic plaque rupture.

    PubMed

    Roth, Lynn; Rombouts, Miche; Schrijvers, Dorien M; Martinet, Wim; De Meyer, Guido R Y

    2016-05-01

    Because cholesterol-independent effects of statins are difficult to determine in patients, we studied these pleiotropic effects in apolipoprotein E-deficient (ApoE(-/-)) mice with a mutation in the fibrillin-1 gene (Fbn1(C1039G+/-)). These mice develop exacerbated atherosclerosis and spontaneous plaque ruptures, accompanied by myocardial infarctions (MI) and sudden death. ApoE(-/-)Fbn1(C1039G+/-) mice were fed a Western diet (WD). At week 10 of WD, mice were divided in a control (WD), atorvastatin (10mg/kg/day + WD) and cholesterol withdrawal group (cholW, normal chow). The latter was included to compare the effects of atorvastatin with dietary lipid lowering. Fifteen weeks later, the mice were sacrificed. CholW, but not atorvastatin, reduced plasma cholesterol. Survival increased from 50% to 90% both in cholW and atorvastatin treated mice. CholW as well as atorvastatin treatment increased plaque collagen and fibrous cap thickness, but they did not affect the amount of plaque macrophages and T cells. MMP-2 and MMP-9 activity was significantly lower and the expression of MMP-12, TNF-α and IL-1β was strongly reduced in both treatment groups. Blood monocytes and neutrophils returned to baseline levels (ApoE(-/-) mice before the onset of atherosclerosis). Importantly, atorvastatin but not cholW significantly reduced coronary stenosis (from 50 to 28%) and the occurrence of MI (from 43 to 10%). In conclusion, independent of cholesterol lowering, atorvastatin significantly reduced mortality, plaque vulnerability and inflammation to the same extent as cholW. In addition, atorvastatin but not cholW reduced coronary stenosis and the occurrence of MI. These data unequivocally illustrate the significance of the pleiotropic effects of atorvastatin in the prevention of cardiovascular morbidity and mortality.

  15. Plaque Size Is Decreased but M1 Macrophage Polarization and Rupture Related Metalloproteinase Expression Are Maintained after Deleting T-Bet in ApoE Null Mice

    PubMed Central

    Tsaousi, Aikaterini; Hayes, Elaine M.; Di Gregoli, Karina; Bond, Andrew R.; Bevan, Laura

    2016-01-01

    Background Thelper1 (Th1) lymphocytes have been previously implicated in atherosclerotic plaque growth but their role in plaque vulnerability to rupture is less clear. We investigated whether T-bet knockout that prevents Th1 lymphocyte differentiation modulates classical (M1) macrophage activation or production of matrix degrading metalloproteinases (MMPs) and their tissue inhibitors, TIMPs. Methods & Results We studied the effect of T-bet deletion in apolipoproteinE (ApoE) knockout mice fed a high fat diet (HFD) or normal chow diet (ND). Transcript levels of M1/M2 macrophage polarization markers, selected MMPs and TIMPs were measured by RT-qPCR in macrophages isolated from subcutaneous granulomas or in whole aortae. Immunohistochemistry of aortic sinus (AS) and brachiocephalic artery (BCA) plaques was conducted to quantify protein expression of the same factors. Deletion of T-bet decreased mRNA for the M1 marker NOS-2 in granuloma macrophages but levels of M2 markers (CD206, arginase-1 and Ym-1), MMPs-2, -9, -12, -13, -14 and -19 or TIMPs-1 to -3 were unchanged. No mRNA differences were observed in aortic extracts from mice fed a HFD for 12 weeks. Moreover, AS and BCA plaques were similarly sized between genotypes, and had similar areas stained for NOS-2, COX-2, MMP-12 and MMP-14 proteins. T-bet deletion increased MMP-13, MMP-14 and arginase-1 in AS plaques. After 35 weeks of ND, T-bet deletion reduced the size of AS and BCA plaques but there were no differences in the percentage areas stained for M1 or M2 markers, MMPs-12, -13, -14, or TIMP-3. Conclusions Absence of Th1 lymphocytes is associated with reduced plaque size in ApoE knockout mice fed a normal but not high fat diet. In either case, M1 macrophage polarization and expression of several MMPs related to plaque instability are either maintained or increased. PMID:26886778

  16. Cap buckling as a potential mechanism of atherosclerotic plaque vulnerability.

    PubMed

    Abdelali, Maria; Reiter, Steven; Mongrain, Rosaire; Bertrand, Michel; L'Allier, Philippe L; Kritikou, Ekaterini A; Tardif, Jean-Claude

    2014-04-01

    Plaque rupture in atherosclerosis is the primary cause of potentially deadly coronary events, yet about 40% of ruptures occur away from the plaque cap shoulders and cannot be fully explained with the current biomechanical theories. Here, cap buckling is considered as a potential destabilizing factor which increases the propensity of the atherosclerotic plaque to rupture and which may also explain plaque failure away from the cap shoulders. To investigate this phenomenon, quasistatic 2D finite element simulations are performed, considering the salient geometrical and nonlinear material properties of diverse atherosclerotic plaques over the range of physiological loads. The numerical results indicate that buckling may displace the location of the peak von Mises stresses in the deflected caps. Plaque buckling, together with its deleterious effects is further observed experimentally in plaque caps using a physical model of deformable mock coronary arteries with fibroatheroma. Moreover, an analytical approach combining quasistatic equilibrium equations with the Navier-Bresse formulas is used to demonstrate the buckling potential of a simplified arched slender cap under intraluminal pressure and supported by foundations. This analysis shows that plaque caps - calcified, fibrotic or cellular - may buckle in specific undulated shapes once submitted to critical loads. Finally, a preliminary analysis of intravascular ultrasonography recordings of patients with atherosclerotic coronary arteries corroborates the numerical, experimental and theoretical findings and shows that various plaque caps buckle in vivo. By displacing the sites of high stresses in the plaque cap, buckling may explain the atherosclerotic plaque cap rupture at various locations, including cap shoulders.

  17. The vulnerable and unstable atherosclerotic plaque.

    PubMed

    Fishbein, Michael C

    2010-01-01

    The lesion responsible for the overwhelming majority of acute coronary events is plaque disruption or erosion with superimposed thrombosis. The term "vulnerable plaque" has been used to describe those atherosclerotic plaques that are particularly susceptible to disruption. Vulnerable plaques are generally characterized as those having a thin inflamed fibrous cap over a very large lipid core. However, only a small percentage of such plaques rupture, and plaques with different characteristics may also rupture and thrombose. Most autopsy, intravascular ultrasound, and recent computed tomography angiographic studies of coronary arteries reveal large plaques at sites of rupture. While angiographic data are said to show less severe narrowing at sites of plaque rupture, actual review of data indicates that, even angiographically, more than 50% of plaques have greater than 75% cross-sectional area stenosis at sites of plaque rupture. If plaque rupture is more common at the shoulder region of a plaque, one could envision that this would be at a peripheral site of the plaque where the plaque may not be as large or occlusive. New knowledge about vulnerable plaques is emerging through the evolution of novel techniques used to study plaques in vivo. These methods combine sophisticated imaging techniques, often in conjunction with molecular biomarkers, that provide new insights into plaque biology. Since atherosclerotic coronary artery disease is such a widespread and fatal disease, it is important that we continue to strive for a greater understanding of the nature of the vulnerable plaque. Only then can rational interventions for this disorder be developed and implemented.

  18. Imaging Modalities to Identity Inflammation in an Atherosclerotic Plaque

    PubMed Central

    Goel, Sunny; Miller, Avraham; Agarwal, Chirag; Zakin, Elina; Acholonu, Michael; Gidwani, Umesh; Sharma, Abhishek; Kulbak, Guy; Shani, Jacob; Chen, On

    2015-01-01

    Atherosclerosis is a chronic, progressive, multifocal arterial wall disease caused by local and systemic inflammation responsible for major cardiovascular complications such as myocardial infarction and stroke. With the recent understanding that vulnerable plaque erosion and rupture, with subsequent thrombosis, rather than luminal stenosis, is the underlying cause of acute ischemic events, there has been a shift of focus to understand the mechanisms that make an atherosclerotic plaque unstable or vulnerable to rupture. The presence of inflammation in the atherosclerotic plaque has been considered as one of the initial events which convert a stable plaque into an unstable and vulnerable plaque. This paper systemically reviews the noninvasive and invasive imaging modalities that are currently available to detect this inflammatory process, at least in the intermediate stages, and discusses the ongoing studies that will help us to better understand and identify it at the molecular level. PMID:26798515

  19. Impaired gait pattern as a sensitive tool to assess hypoxic brain damage in a novel mouse model of atherosclerotic plaque rupture.

    PubMed

    Roth, Lynn; Van Dam, Debby; Van der Donckt, Carole; Schrijvers, Dorien M; Lemmens, Katrien; Van Brussel, Ilse; De Deyn, Peter P; Martinet, Wim; De Meyer, Guido R Y

    2015-02-01

    Apolipoprotein E deficient (ApoE(-/-)) mice with a heterozygous mutation in the fibrillin-1 gene (Fbn1(C1039G+/-)) show spontaneous atherosclerotic plaque ruptures, disturbances in cerebral flow and sudden death when fed a Western-type diet (WD). The present study focused on motor coordination and spatial learning of ApoE(-/-) Fbn1(C1039G+/-) mice on WD for 20 weeks (n=21). ApoE(-/-) mice on WD (n=24) and ApoE(-/-) Fbn1(C1039G+/-) mice on normal diet (ND, n=21) served as controls. Starting from 10 weeks of diet, coordination was assessed every two weeks by the following tests: gait analysis, stationary beam, wire suspension and accelerating rotarod. The Morris water maze test was performed after 13 weeks of diet to study spatial learning. At the end of the experiment (20 weeks of WD), the mice were sacrificed and the brachiocephalic artery and brain were isolated. From 12 weeks onward, gait analysis of ApoE(-/-) Fbn1(C1039G+/-) mice on WD revealed a progressive increase in track width as compared to ApoE(-/-) mice on WD and ApoE(-/-) Fbn1(C1039G+/-) mice on ND (at 20 weeks: 29.8±0.6 mm vs. 25.8±0.4 mm and 26.0±0.5 mm). Moreover, the stationary beam test showed a decrease in motor coordination of ApoE(-/-) Fbn1(C1039G+/-) mice on WD at 18 and 20 weeks. The wire suspension test and accelerating rotarod could not detect signs of motor impairment. Spatial learning was also not affected. Histological analysis of the brachiocephalic artery showed larger and more stenotic plaques in ApoE(-/-) Fbn1(C1039G+/-) mice on WD. Furthermore, the parietal cortex of ApoE(-/-) Fbn1(C1039G+/-) mice on WD showed pyknotic nuclei as a sign of hypoxia and the percentage of pyknosis correlated with track width. In conclusion, gait analysis may be an efficient method for analyzing hypoxic brain damage in the ApoE(-/-) Fbn1(C1039G+/-) mouse model. This test could be of value to assess the effect of potential anti-atherosclerotic therapies in mice.

  20. The Vulnerable Plaque: the Real Villain in Acute Coronary Syndromes

    PubMed Central

    Liang, Michael; Puri, Aniket; Devlin, Gerard

    2011-01-01

    The term "vulnerable plaque" refers to a vascular lesion that is prone to rupture and may result in life-threatening events which include myocardial infarction. It consists of thin-cap fibroatheroma and a large lipid core which is highly thrombogenic. Acute coronary syndromes often result from rupture of vulnerable plaques which frequently are only moderately stenosed and not visible by conventional angiography. Several invasive and non-invasive strategies have been developed to assess the burden of vulnerable plaques. Intravascular ultrasound provides a two-dimensional cross-sectional image of the arterial wall and can help assess the plaque burden and composition. Optical coherent tomography offers superior resolution over intravascular ultrasound. High-resolution magnetic resonance imaging provides non-invasive imaging for visualizing fibrous cap thickness and rupture in plaques. In addition, it may be of value in assessing the effects of treatments, such as lipid-lowering therapy. Technical issues however limit its clinical applicability. The role of multi-slice computed tomography, a well established screening tool for coronary artery disease, remains to be determined. Fractional flow reserve (FFR) may provide physiological functional assessment of plaque vulnerability; however, its role in the management of vulnerable plaque requires further studies. Treatment of the vulnerable patient may involve systemic therapy which currently include statins, ACE inhibitors, beta-blockers, aspirin, and calcium-channel blockers and in the future local therapeutic options such as drug-eluting stents or photodynamic therapy. PMID:21673834

  1. High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis

    PubMed Central

    Wang, Yi; Qiu, Juhui; Luo, Shisui; Xie, Xiang; Zheng, Yiming; Zhang, Kang; Ye, Zhiyi; Liu, Wanqian; Gregersen, Hans; Wang, Guixue

    2016-01-01

    Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions. PMID:27482467

  2. High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

    PubMed Central

    Rampazo, Érika P.; Liebano, Richard E.; Pinfildi, Carlos Eduardo; Folha, Roberta A. C.; Ferreira, Lydia M.

    2016-01-01

    ABSTRACT Objective To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats. Method Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification. Results No significant difference was observed among the groups regarding collagen realignment (types I or III collagen) or quantity of blood vessels. Conclusion High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats. PMID:27556387

  3. Vulnerable atherosclerotic carotid plaque evaluation by ultrasound, computed tomography angiography, and magnetic resonance imaging: an overview.

    PubMed

    Naim, Cyrille; Douziech, Maxime; Therasse, Eric; Robillard, Pierre; Giroux, Marie-France; Arsenault, Frederic; Cloutier, Guy; Soulez, Gilles

    2014-08-01

    Ischemic syndromes associated with carotid atherosclerotic disease are often related to plaque rupture. The benefit of endarterectomy for high-grade carotid stenosis in symptomatic patients has been established. However, in asymptomatic patients, the benefit of endarterectomy remains equivocal. Current research seeks to risk stratify asymptomatic patients by characterizing vulnerable, rupture-prone atherosclerotic plaques. Plaque composition, biology, and biomechanics are studied by noninvasive imaging techniques such as magnetic resonance imaging, computed tomography, ultrasound, and ultrasound elastography. These techniques are at a developmental stage and have yet to be used in clinical practice. This review will describe noninvasive techniques in ultrasound, magnetic resonance imaging, and computed tomography imaging modalities used to characterize atherosclerotic plaque, and will discuss their potential clinical applications, benefits, and drawbacks.

  4. Update on aneurysm disease: current insights and controversies: peripheral aneurysms: when to intervene - is rupture really a danger?

    PubMed

    Dawson, Joe; Fitridge, Robert

    2013-01-01

    Peripheral artery aneurysms are rarer than abdominal aortic aneurysms (AAA), although the true prevalence is not well known. They often coexist with aortic and other peripheral artery aneurysms. In contrast to AAA, where the principal risk is that of rupture, thromboembolism is more common, contributing a bigger risk in the more common lesions. Although rupture does occur, with incidence related to anatomical site, aneurysm diameter cannot be used to guide management with the same confidence as in AAA. In addition, the rarity of these lesions results in a paucity of evidence with which to guide intervention. Consequently they are difficult lesions to manage, and numerous aneurysm and patient factors must be considered to provide treatment individualised for each case. We discuss popliteal, femoral, carotid, subclavian, upper limb, visceral and false aneurysms, focussing on the risk of rupture and thromboembolism, and current thresholds for intervention, based on the available published literature.

  5. Inhibiting macrophage proliferation suppresses atherosclerotic plaque inflammation.

    PubMed

    Tang, Jun; Lobatto, Mark E; Hassing, Laurien; van der Staay, Susanne; van Rijs, Sarian M; Calcagno, Claudia; Braza, Mounia S; Baxter, Samantha; Fay, Francois; Sanchez-Gaytan, Brenda L; Duivenvoorden, Raphaël; Sager, Hendrik; Astudillo, Yaritzy M; Leong, Wei; Ramachandran, Sarayu; Storm, Gert; Pérez-Medina, Carlos; Reiner, Thomas; Cormode, David P; Strijkers, Gustav J; Stroes, Erik S G; Swirski, Filip K; Nahrendorf, Matthias; Fisher, Edward A; Fayad, Zahi A; Mulder, Willem J M

    2015-04-01

    Inflammation drives atherosclerotic plaque progression and rupture, and is a compelling therapeutic target. Consequently, attenuating inflammation by reducing local macrophage accumulation is an appealing approach. This can potentially be accomplished by either blocking blood monocyte recruitment to the plaque or increasing macrophage apoptosis and emigration. Because macrophage proliferation was recently shown to dominate macrophage accumulation in advanced plaques, locally inhibiting macrophage proliferation may reduce plaque inflammation and produce long-term therapeutic benefits. To test this hypothesis, we used nanoparticle-based delivery of simvastatin to inhibit plaque macrophage proliferation in apolipoprotein E deficient mice (Apoe(-/-) ) with advanced atherosclerotic plaques. This resulted in rapid reduction of plaque inflammation and favorable phenotype remodeling. We then combined this short-term nanoparticle intervention with an eight-week oral statin treatment, and this regimen rapidly reduced and continuously suppressed plaque inflammation. Our results demonstrate that pharmacologically inhibiting local macrophage proliferation can effectively treat inflammation in atherosclerosis.

  6. Inhibiting macrophage proliferation suppresses atherosclerotic plaque inflammation

    PubMed Central

    Tang, Jun; Lobatto, Mark E.; Hassing, Laurien; van der Staay, Susanne; van Rijs, Sarian M.; Calcagno, Claudia; Braza, Mounia S.; Baxter, Samantha; Fay, Francois; Sanchez-Gaytan, Brenda L.; Duivenvoorden, Raphaël; Sager, Hendrik B.; Astudillo, Yaritzy M.; Leong, Wei; Ramachandran, Sarayu; Storm, Gert; Pérez-Medina, Carlos; Reiner, Thomas; Cormode, David P.; Strijkers, Gustav J.; Stroes, Erik S. G.; Swirski, Filip K.; Nahrendorf, Matthias; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

    2015-01-01

    Inflammation drives atherosclerotic plaque progression and rupture, and is a compelling therapeutic target. Consequently, attenuating inflammation by reducing local macrophage accumulation is an appealing approach. This can potentially be accomplished by either blocking blood monocyte recruitment to the plaque or increasing macrophage apoptosis and emigration. Because macrophage proliferation was recently shown to dominate macrophage accumulation in advanced plaques, locally inhibiting macrophage proliferation may reduce plaque inflammation and produce long-term therapeutic benefits. To test this hypothesis, we used nanoparticle-based delivery of simvastatin to inhibit plaque macrophage proliferation in apolipoprotein E–deficient mice (Apoe−/−) with advanced atherosclerotic plaques. This resulted in the rapid reduction of plaque inflammation and favorable phenotype remodeling. We then combined this short-term nanoparticle intervention with an 8-week oral statin treatment, and this regimen rapidly reduced and continuously suppressed plaque inflammation. Our results demonstrate that pharmacologically inhibiting local macrophage proliferation can effectively treat inflammation in atherosclerosis. PMID:26295063

  7. Intracoronary Near-Infrared Spectroscopy (NIRS) Imaging for Detection of Lipid Content of Coronary Plaques: Current Experience and Future Perspectives.

    PubMed

    Jaguszewski, Milosz; Klingenberg, Roland; Landmesser, Ulf

    2013-01-01

    Acute coronary syndromes are frequently caused by "vulnerable" coronary plaques with a lipid-rich core. In 1993 near-infrared spectroscopy (NIRS) was first used to detect the lipid (cholesterol) content of atherosclerotic plaques in an experimental animal study. NIRS was then carefully validated using human atherosclerotic plaques (ex vivo), and has subsequently been developed for intracoronary imaging in humans, for which now an FDA-approved catheter-based NIRS system is available. NIRS provides a "chemogram" of the coronary artery wall and is used to detect lipid-rich plaques. Using this technology, recent studies have shown that lipid-rich plaques are very frequent in the culprit lesion of patients with an acute coronary syndrome, and are also common in non-culprit coronary lesions in these patients as compared to patients with stable coronary disease. First studies are evaluating the impact of statin therapy on coronary NIRS-detected lipid cores. Intracoronary NIRS imaging represents a highly interesting method for coronary plaque characterization in humans and may become a valuable tool for the development of novel therapies aiming to impact on the biology of human coronary artery plaques, likely in combination with other intracoronary imaging techniques, such as optical coherence tomography.

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

    PubMed

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

    2016-01-01

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

  9. Ultrafast optical-ultrasonic system and miniaturized catheter for imaging and characterizing atherosclerotic plaques in vivo

    PubMed Central

    Li, Jiawen; Ma, Teng; Mohar, Dilbahar; Steward, Earl; Yu, Mingyue; Piao, Zhonglie; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Patel, Pranav M.; Chen, Zhongping

    2015-01-01

    Atherosclerotic coronary artery disease (CAD) is the number one cause of death worldwide. The majority of CAD-induced deaths are due to the rupture of vulnerable plaques. Accurate assessment of plaques is crucial to optimize treatment and prevent death in patients with CAD. Current diagnostic techniques are often limited by either spatial resolution or penetration depth. Several studies have proved that the combined use of optical and ultrasonic imaging techniques increase diagnostic accuracy of vulnerable plaques. Here, we introduce an ultrafast optical-ultrasonic dual-modality imaging system and flexible miniaturized catheter, which enables the translation of this technology into clinical practice. This system can perform simultaneous optical coherence tomography (OCT)-intravascular ultrasound (IVUS) imaging at 72 frames per second safely in vivo, i.e., visualizing a 72 mm-long artery in 4 seconds. Results obtained in atherosclerotic rabbits in vivo and human coronary artery segments show that this ultrafast technique can rapidly provide volumetric mapping of plaques and clearly identify vulnerable plaques. By providing ultrafast imaging of arteries with high resolution and deep penetration depth simultaneously, this hybrid IVUS-OCT technology opens new and safe opportunities to evaluate in real-time the risk posed by plaques, detect vulnerable plaques, and optimize treatment decisions. PMID:26678300

  10. 3D MRI-based anisotropic FSI models with cyclic bending for human coronary atherosclerotic plaque mechanical analysis.

    PubMed

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

    2009-06-01

    Heart attack and stroke are often caused by atherosclerotic plaque rupture, which happens without warning most of the time. Magnetic resonance imaging (MRI)-based atherosclerotic plaque models with fluid-structure interactions (FSIs) have been introduced to perform flow and stress/strain analysis and identify possible mechanical and morphological indices for accurate plaque vulnerability assessment. For coronary arteries, cyclic bending associated with heart motion and anisotropy of the vessel walls may have significant influence on flow and stress/strain distributions in the plaque. FSI models with cyclic bending and anisotropic vessel properties for coronary plaques are lacking in the current literature. In this paper, cyclic bending and anisotropic vessel properties were added to 3D FSI coronary plaque models so that the models would be more realistic for more accurate computational flow and stress/strain predictions. Six computational models using one ex vivo MRI human coronary plaque specimen data were constructed to assess the effects of cyclic bending, anisotropic vessel properties, pulsating pressure, plaque structure, and axial stretch on plaque stress/strain distributions. Our results indicate that cyclic bending and anisotropic properties may cause 50-800% increase in maximum principal stress (Stress-P1) values at selected locations. The stress increase varies with location and is higher when bending is coupled with axial stretch, nonsmooth plaque structure, and resonant pressure conditions (zero phase angle shift). Effects of cyclic bending on flow behaviors are more modest (9.8% decrease in maximum velocity, 2.5% decrease in flow rate, 15% increase in maximum flow shear stress). Inclusion of cyclic bending, anisotropic vessel material properties, accurate plaque structure, and axial stretch in computational FSI models should lead to a considerable improvement of accuracy of computational stress/strain predictions for coronary plaque vulnerability

  11. Mechanical analysis of arterial plaques in native geometry with OCT wall motion analysis

    PubMed Central

    Robertson, Claire; Heidari, Andrew E.; Chen, Zhongping; George, Steven C.

    2014-01-01

    The mechanical behavior of an atherosclerotic plaque may encode information about the type, composition, and vulnerability to rupture. Human arterial segments with varying plaque burden were analyzed ex vivo with optical coherence tomography (OCT) to determine plaque type and to determine compliance during pulsatile inflation in their native geometry. Calcifications and lipid filled plaques showed markedly different compliance when analyzed with OCT wall motion analysis. There was also a trend towards increased circumferential variation in arterial compliance with increasing plaque burden. PMID:24388166

  12. Molecular Imaging of Vulnerable Atherosclerotic Plaques in Animal Models

    PubMed Central

    Gargiulo, Sara; Gramanzini, Matteo; Mancini, Marcello

    2016-01-01

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

  13. The role of near-infrared spectroscopy in the detection of vulnerable atherosclerotic plaques

    PubMed Central

    Hajek, Petr; Stechovsky, Cyril; Honek, Jakub; Spacek, Miloslav; Veselka, Josef

    2016-01-01

    Coronary artery disease is the leading cause of mortality worldwide. Most acute coronary syndromes are caused by a rupture of a vulnerable atherosclerotic plaque which can be characterized by a lipid-rich necrotic core with an overlying thin fibrous cap. Many vulnerable plaques can cause angiographically mild stenoses due to positive remodelling, which is why the extent of coronary artery disease may be seriously underestimated. In recent years, we have witnessed a paradigm shift in interventional cardiology. We no longer focus solely on the degree of stenosis; rather, we seek to determine the true extent of atherosclerotic disease. We seek to identify high-risk plaques for improvement in risk stratification of patients and prevention. Several imaging methods have been developed for this purpose. Intracoronary near-infrared spectroscopy is one of the most promising. Here, we discuss the possible applications of this diagnostic method and provide a comprehensive overview of the current knowledge. PMID:27904523

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

    PubMed Central

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

    2014-01-01

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

  15. Multiphoton microscopy of atheroslcerotic plaques

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

    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.

  16. Vascular MR segmentation: wall and plaque

    NASA Astrophysics Data System (ADS)

    Yang, Fuxing; Holzapfel, Gerhard; Schulze-Bauer, Christian; Stollberger, Rudolf; Thedens, Daniel; Bolinger, Lizann; Stolpen, Alan; Sonka, Milan

    2003-05-01

    Cardiovascular events frequently result from local rupture of vulnerable atherosclerotic plaque. Non-invasive assessment of plaque vulnerability is needed to allow institution of preventive measures before heart attack or stroke occur. A computerized method for segmentation of arterial wall layers and plaque from high-resolution volumetric MR images is reported. The method uses dynamic programming to detect optimal borders in each MRI frame. The accuracy of the results was tested in 62 T1-weighted MR images from 6 vessel specimens in comparison to borders manually determined by an expert observer. The mean signed border positioning errors for the lumen, internal elastic lamina, and external elastic lamina borders were -0.12+/-0.14 mm, 0.04+/-0.12mm, and -0.15+/-0.13 mm, respectively. The presented wall layer segmentation approach is one of the first steps towards non-invasive assessment of plaque vulnerability in atherosclerotic subjects.

  17. Nuclear Molecular Imaging for Vulnerable Atherosclerotic Plaques

    PubMed Central

    Lee, Soo Jin

    2015-01-01

    Atherosclerosis is an inflammatory disease as well as a lipid disorder. Atherosclerotic plaque formed in vessel walls may cause ischemia, and the rupture of vulnerable plaque may result in fatal events, like myocardial infarction or stroke. Because morphological imaging has limitations in diagnosing vulnerable plaque, molecular imaging has been developed, in particular, the use of nuclear imaging probes. Molecular imaging targets various aspects of vulnerable plaque, such as inflammatory cell accumulation, endothelial activation, proteolysis, neoangiogenesis, hypoxia, apoptosis, and calcification. Many preclinical and clinical studies have been conducted with various imaging probes and some of them have exhibited promising results. Despite some limitations in imaging technology, molecular imaging is expected to be used both in the research and clinical fields as imaging instruments become more advanced. PMID:26357491

  18. Rupture disc

    DOEpatents

    Newton, Robert G.

    1977-01-01

    The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough.

  19. Artery buckling affects the mechanical stress in atherosclerotic plaques

    PubMed Central

    2015-01-01

    Background Tortuous arteries are often seen in patients with hypertension and atherosclerosis. While the mechanical stress in atherosclerotic plaque under lumen pressure has been studied extensively, the mechanical stability of atherosclerotic arteries and subsequent effect on the plaque stress remain unknown. To this end, we investigated the buckling and post-buckling behavior of model stenotic coronary arteries with symmetric and asymmetric plaque. Methods Buckling analysis for a model coronary artery with symmetric and asymmetric plaque was conducted using finite element analysis based on the dimensions and nonlinear anisotropic materials properties reported in the literature. Results Artery with asymmetric plaque had lower critical buckling pressure compared to the artery with symmetric plaque and control artery. Buckling increased the peak stress in the plaque and led to the development of a high stress concentration in artery with asymmetric plaque. Stiffer calcified tissue and severe stenosis increased the critical buckling pressure of the artery with asymmetric plaque. Conclusions Arteries with atherosclerotic plaques are prone to mechanical buckling which leads to a high stress concentration in the plaques that can possibly make the plaques prone to rupture. PMID:25603490

  20. Growth of Necrotic Cores in Vulnerable Plaque

    NASA Astrophysics Data System (ADS)

    Fok, Pak-Wing

    2011-03-01

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

  1. Stress analysis of fracture of atherosclerotic plaques: crack propagation modeling.

    PubMed

    Rezvani-Sharif, Alireza; Tafazzoli-Shadpour, Mohammad; Kazemi-Saleh, Davood; Sotoudeh-Anvari, Maryam

    2016-12-09

    Traditionally, the degree of luminal obstruction has been used to assess the vulnerability of atherosclerotic plaques. However, recent studies have revealed that other factors such as plaque morphology, material properties of lesion components and blood pressure may contribute to the fracture of atherosclerotic plaques. The aim of this study was to investigate the mechanism of fracture of atherosclerotic plaques based on the mechanical stress distribution and fatigue analysis by means of numerical simulation. Realistic models of type V plaques were reconstructed based on histological images. Finite element method was used to determine mechanical stress distribution within the plaque. Assuming that crack propagation initiated at the sites of stress concentration, crack propagation due to pulsatile blood pressure was modeled. Results showed that crack propagation considerably changed the stress field within the plaque and in some cases led to initiation of secondary cracks. The lipid pool stiffness affected the location of crack formation and the rate and direction of crack propagation. Moreover, increasing the mean or pulse pressure decreased the number of cycles to rupture. It is suggested that crack propagation analysis can lead to a better recognition of factors involved in plaque rupture and more accurate determination of vulnerable plaques.

  2. The Spatial Distribution of Plaque Vulnerabilities in Patients with Acute Myocardial Infarction

    PubMed Central

    Zheng, Guian; Li, Yuxin; Takayama, Tadateru; Nishida, Toshihiko; Sudo, Mitsumasa; Haruta, Hironori; Fukamachi, Daisuke; Okubo, Kimie; Higuchi, Yoshiharu; Hiro, Takafumi; Saito, Satoshi; Hirayama, Atsushi

    2016-01-01

    Objective Although the plaque characteristics have been recognized in patients with acute myocardial infarction (AMI), the plaque spatial distribution is not well clarified. Using color-mapping intravascular ultrasound (iMAP-IVUS), we examined culprit lesions to clarify plaque morphology, composition and spatial distribution of the sites of potential vulnerability. Methods Sixty-eight culprit lesions in 64 consecutive AMI patients who underwent angiography and IVUS examinations before intervention were analyzed. Plaque morphology and composition were quantified with iMAP-IVUS. The spatial distribution of the sites of potential vulnerability was assessed with longitudinal reconstruction of the consecutive IVUS images. The plaque characteristics were also compared between ruptured and non-ruptured lesions, and between totally occlusive (TO) and non-TO lesions. Results The sites with maximum necrotic area (maxNA), maximum plaque burden (maxPB) and most severely narrowed (minimal luminal area, MLA) were recognized vulnerability. In the majority of cases, maxNA sites were proximal to the maxPB sites, and MLA sites were distal to the maxNA and maxPB sites. Ruptures usually occurred close to maxNA sites and proximal to maxPB and MLA sites. The average distance from the site of rupture to the maxNA site was 0.33 ± 4.04 mm. Ruptured lesions showed significant vessel remodeling, greater plaque volume, and greater lipidic volume compared to those of non-ruptured lesions. Both the length and plaque burden (PB) of TO lesions were greater than those of non-TO lesions. Conclusions Instead of overlapping on maxPB sites, most maxNA sites are proximal to the maxPB sites and are the sites most likely to rupture. Plaque morphology and composition play critical roles in plaque rupture and coronary occlusion. PMID:27031514

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

    DOE PAGES

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

    2015-11-25

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

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

    SciTech Connect

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

    2015-11-25

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

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

    NASA Astrophysics Data System (ADS)

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

    2006-02-01

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

  6. In Vivo/Ex Vivo MRI-Based 3D Non-Newtonian FSI Models for Human Atherosclerotic Plaques Compared with Fluid/Wall-Only Models.

    PubMed

    Yang, Chun; Tang, Dalin; Yuan, Chun; Hatsukami, Thomas S; Zheng, Jie; Woodard, Pamela K

    2007-01-01

    It has been recognized that fluid-structure interactions (FSI) play an important role in cardiovascular disease initiation and development. However, in vivo MRI multi-component FSI models for human carotid atherosclerotic plaques with bifurcation and quantitative comparisons of FSI models with fluid-only or structure-only models are currently lacking in the literature. A 3D non-Newtonian multi-component FSI model based on in vivo/ex vivo MRI images for human atherosclerotic plaques was introduced to investigate flow and plaque stress/strain behaviors which may be related to plaque progression and rupture. Both artery wall and plaque components were assumed to be hyperelastic, isotropic, incompressible and homogeneous. Blood flow was assumed to be laminar, non-Newtonian, viscous and incompressible. In vivo/ex vivo MRI images were acquired using histologically-validated multi-spectral MRI protocols. The 3D FSI models were solved and results were compared with those from a Newtonian FSI model and wall-only/fluid-only models. A 145% difference in maximum principal stresses (Stress-P(1)) between the FSI and wall-only models and 40% difference in flow maximum shear stress (MSS) between the FSI and fluid-only models were found at the throat of the plaque using a severe plaque sample (70% severity by diameter). Flow maximum shear stress (MSS) from the rigid wall model is much higher (20-40% in maximum MSS values, 100-150% in stagnation region) than those from FSI models.

  7. Atherosclerotic plaque regression: fact or fiction?

    PubMed

    Shanmugam, Nesan; Román-Rego, Ana; Ong, Peter; Kaski, Juan Carlos

    2010-08-01

    Coronary artery disease is the major cause of death in the western world. The formation and rapid progression of atheromatous plaques can lead to serious cardiovascular events in patients with atherosclerosis. The better understanding, in recent years, of the mechanisms leading to atheromatous plaque growth and disruption and the availability of powerful HMG CoA-reductase inhibitors (statins) has permitted the consideration of plaque regression as a realistic therapeutic goal. This article reviews the existing evidence underpinning current therapeutic strategies aimed at achieving atherosclerotic plaque regression. In this review we also discuss imaging modalities for the assessment of plaque regression, predictors of regression and whether plaque regression is associated with a survival benefit.

  8. Imaging atherosclerosis and vulnerable plaque.

    PubMed

    Sadeghi, Mehran M; Glover, David K; Lanza, Gregory M; Fayad, Zahi A; Johnson, Lynne L

    2010-05-01

    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.

  9. Ultrafast laser ablation for targeted atherosclerotic plaque removal

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  10. Ruptured Intracranial Dermoid Cyst Associated with Rupture of Cerebral Aneurysm

    PubMed Central

    Kim, Ki Hong

    2011-01-01

    Many tumors have been reported to coexist with cerebral aneurysm. However, intracranial dermoid cysts associated with cerebral aneurysm are very rare. We report a case in which rupture of a cerebral aneurysm resulted in a ruptured dermoid cyst. We present this interesting case and review current literature about the relationship between tumors and aneurysm formation. PMID:22259693

  11. Biomechanical Rupture Risk Assessment

    PubMed Central

    2016-01-01

    Abdominal aortic aneurysm (AAA) rupture is a local event in the aneurysm wall that naturally demands tools to assess the risk for local wall rupture. Consequently, global parameters like the maximum diameter and its expansion over time can only give very rough risk indications; therefore, they frequently fail to predict individual risk for AAA rupture. In contrast, the Biomechanical Rupture Risk Assessment (BRRA) method investigates the wall’s risk for local rupture by quantitatively integrating many known AAA rupture risk factors like female sex, large relative expansion, intraluminal thrombus-related wall weakening, and high blood pressure. The BRRA method is almost 20 years old and has progressed considerably in recent years, it can now potentially enrich the diameter indication for AAA repair. The present paper reviews the current state of the BRRA method by summarizing its key underlying concepts (i.e., geometry modeling, biomechanical simulation, and result interpretation). Specifically, the validity of the underlying model assumptions is critically disused in relation to the intended simulation objective (i.e., a clinical AAA rupture risk assessment). Next, reported clinical BRRA validation studies are summarized, and their clinical relevance is reviewed. The BRRA method is a generic, biomechanics-based approach that provides several interfaces to incorporate information from different research disciplines. As an example, the final section of this review suggests integrating growth aspects to (potentially) further improve BRRA sensitivity and specificity. Despite the fact that no prospective validation studies are reported, a significant and still growing body of validation evidence suggests integrating the BRRA method into the clinical decision-making process (i.e., enriching diameter-based decision-making in AAA patient treatment). PMID:27757402

  12. Ruptured eardrum

    MedlinePlus

    ... Avoid swimming or putting your head underneath the water. Your provider may prescribe antibiotics (oral or ear drops) to prevent or treat an infection. Repair of the eardrum might be needed for larger holes or ruptures or if the eardrum does not ...

  13. Achilles Tendon Rupture

    PubMed Central

    Wertz, Jess; Galli, Melissa; Borchers, James R.

    2013-01-01

    Context: Achilles tendon (AT) rupture in athletes is increasing in incidence and accounts for one of the most devastating sports injuries because of the threat to alter or end a career. Despite the magnitude of this injury, reliable risk assessment has not been clearly defined, and prevention strategies have been limited. The purpose of this review is to identify potential intrinsic and extrinsic risk factors for AT rupture in aerial and ground athletes stated in the current literature. Evidence Acquisition: A MEDLINE search was conducted on AT rupture, or “injury” and “risk factors” and “athletes” from 1980 to 2011. Emphasis was placed on epidemiology, etiology, and review articles focusing on the risk for lower extremity injury in runners and gymnasts. Thirty articles were reviewed, and 22 were included in this assessment. Results: Aerial and ground athletes share many intrinsic risk factors for AT rupture, including overuse and degeneration of the tendon as well as anatomical variations that mechanically put an athlete at risk. Older athletes, athletes atypical in size for their sport, high tensile loads, leg dominance, and fatigue also may increase risk. Aerial athletes tend to have more extrinsic factors that play a role in this injury due to the varying landing surfaces from heights and technical maneuvers performed at various skill levels. Conclusion: Risk assessment for AT rupture in aerial and ground athletes is multivariable and difficult in terms of developing prevention strategies. Quantitative measures of individual risk factors may help identify major contributors to injury. PMID:24427410

  14. Research Progress on the Risk Factors and Outcomes of Human Carotid Atherosclerotic Plaques

    PubMed Central

    Xiong, Xiang-Dong; Xiong, Wei-Dong; Xiong, Shang-Shen; Chen, Gui-Hai

    2017-01-01

    Objective: Atherosclerosis is an inflammatory process that results in complex lesions or plaques that protrude into the arterial lumen. Carotid atherosclerotic plaque rupture, with distal atheromatous debris embolization, causes cerebrovascular events. This review aimed to explore research progress on the risk factors and outcomes of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention. Data Sources: We searched the PubMed database for recently published research articles up to June 2016, with the key words of “risk factors”, “outcomes”, “blood components”, “molecular mechanisms”, “cellular mechanisms”, and “human carotid atherosclerotic plaques”. Study Selection: The articles, regarding the latest developments related to the risk factors and outcomes, atherosclerotic plaque composition, blood components, and consequences of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention, were selected. Results: This review described the latest researches regarding the interactive effects of both traditional and novel risk factors for human carotid atherosclerotic plaques, novel insights into human carotid atherosclerotic plaque composition and blood components, and consequences of human carotid atherosclerotic plaque. Conclusion: Carotid plaque biology and serologic biomarkers of vulnerability can be used to predict the risk of cerebrovascular events. Furthermore, plaque composition, rather than lesion burden, seems to most predict rupture and subsequent thrombosis. PMID:28303857

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

    PubMed Central

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

    2014-01-01

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

  16. Mechanical modeling of cholesterol crystallization in atherosclerotic plaques base on Micro-OCT images (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Luo, Yuemei; Liu, Xinyu; Chen, Si; Cui, Dongyao; Wang, Xianghong; Liu, Linbo

    2016-02-01

    Plaque rupture is the critical cause of cardiovascular thrombosis but this process is still under discussion. Recent studies show that, during crystallization, cholesterol crystals in atheromatous plaques accumulate rapidly in a limited space and may result in plaque rupture. However, the actual role of cholesterol crystals on plaque rupture remains unclear due to the lack of detailed morphological information of cholesterol crystals. In this study, we used a Micro-optical coherence tomography (µOCT) setup with 1-2 µm spatial resolution to extract the geometry of cholesterol crystals from human atherosclerotic artery ex vivo firstly. With measured dimensions of cholesterol crystals by this µOCT system (the average length and thickness of 269.1±80.16 µm and 3.0±0.33 µm), we developed a two-dimensional mechanical model in which rectangular shaped cholesterol crystals distribute at different locations spatially. We predicted the stress on the thin cap induced by the expansion of cholesterol crystals by use of finite-element method. Since a large portion of plaques (58%) rupture at points of peak circumferential stress (PCS), we used PCS as the primary indicator of plaque stability with blood pressure of 14.6 kPa on the lumen. The results demonstrate that loading of the concentrated crystals especially at the cap shoulder destabilize the plaque by proportionally increasing the PCS, while evenly distributed crystals loading along the cap might impose less PCS to the plaque than the concentrated case.

  17. Aortic atherosclerotic plaque detection using a multiwavelength handheld photoacoustic imaging system

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  18. Application of infrared fiber optic imaging in atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

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

    1999-07-01

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

  19. Aterofisiol® in carotid plaque evolution

    PubMed Central

    Amato, Bruno; Compagna, Rita; Amato, Maurizio; Gallelli, Luca; de Franciscis, Stefano; Serra, Raffaele

    2015-01-01

    Background In patients with carotid stenosis, the risk of plaque rupture is related to the composition of the atherosclerotic plaque rather than to its magnitude. In this regard, we evaluated the effects of a supplement, Aterofisiol,® containing omega-3 (EPA [eicosapen acid] DHA [docosahexaenoic acid]), vitamin K2, vitamin B6, vitamin B12, oligomeric proanthocyanidins (OPC) and resveratrol on the composition of atherosclerotic plaque and on neurological symptoms in patients with carotid stenosis undergoing carotid endarterectomy. Methods The study was randomized, prospective, and double-blinded. Eligible patients were of both sexes, with carotid stenosis >70% who underwent endarterectomy. Enrolled patients were randomly allocated to receive either one tablet of acetylsalicylic acid 100 mg (Cardioaspirin®) + one tablet of Aterofisiol every 24 hours or one tablet of Cardioaspirin + one tablet of placebo every 24 hours. Each treatment was started 30 days before the surgery and was stopped 5 days before the surgery. The plaques were removed “en bloc” using standard surgical technique. Results During the study period, 214 patients (135 men and 79 women) were enrolled for intent-to-treat and randomized in two groups: Group A: 107 patients (68 men and 39 women) were treated with Cardioaspirin + Aterofisiol. Group B: 107 patients (67 men and 40 women) were treated with Cardioaspirin + placebo. At the end of the study, 202 patients participated fully (103 patients in Group A and 99 patients in Group B), making up the protocol evaluation population (94.4%). The mean lipid content of removed plaques was significantly lower (P<0.05) in Group A. We recorded a significantly lower incidence of neurological symptoms in Group A in comparison with Group B (P<0.05). Conclusion In the study, Aterofisiol showed to be effective in reducing the amounts of cholesterol and lipids in the plaques and in reducing adverse neurological events in the study group with respect to controls

  20. Intracoronary Imaging in the Detection of Vulnerable Plaques.

    PubMed

    Batty, Jonathan A; Subba, Shristy; Luke, Peter; Gigi, Li Wing Chi; Sinclair, Hannah; Kunadian, Vijay

    2016-03-01

    Coronary artery disease is the result of atherosclerotic changes to the coronary arterial wall, comprising endothelial dysfunction, vascular inflammation and deposition of lipid-rich macrophage foam cells. Certain high-risk atherosclerotic plaques are vulnerable to disruption, leading to rupture, thrombosis and the clinical sequelae of acute coronary syndrome. Though recognised as the gold standard for evaluating the presence, distribution and severity of atherosclerotic lesions, invasive coronary angiography is incapable of identifying non-stenotic, vulnerable plaques that are responsible for adverse cardiovascular events. The recognition of such limitations has impelled the development of intracoronary imaging technologies, including intravascular ultrasound, optical coherence tomography and near-infrared spectroscopy, which enable the detailed evaluation of the coronary wall and atherosclerotic plaques in clinical practice. This review discusses the present status of invasive imaging technologies; summarises up-to-date, evidence-based clinical guidelines; and addresses questions that remain unanswered with regard to the future of intracoronary plaque imaging.

  1. Simulation of human atherosclerotic femoral plaque tissue: the influence of plaque material model on numerical results

    PubMed Central

    2015-01-01

    Background Due to the limited number of experimental studies that mechanically characterise human atherosclerotic plaque tissue from the femoral arteries, a recent trend has emerged in current literature whereby one set of material data based on aortic plaque tissue is employed to numerically represent diseased femoral artery tissue. This study aims to generate novel vessel-appropriate material models for femoral plaque tissue and assess the influence of using material models based on experimental data generated from aortic plaque testing to represent diseased femoral arterial tissue. Methods Novel material models based on experimental data generated from testing of atherosclerotic femoral artery tissue are developed and a computational analysis of the revascularisation of a quarter model idealised diseased femoral artery from a 90% diameter stenosis to a 10% diameter stenosis is performed using these novel material models. The simulation is also performed using material models based on experimental data obtained from aortic plaque testing in order to examine the effect of employing vessel appropriate material models versus those currently employed in literature to represent femoral plaque tissue. Results Simulations that employ material models based on atherosclerotic aortic tissue exhibit much higher maximum principal stresses within the plaque than simulations that employ material models based on atherosclerotic femoral tissue. Specifically, employing a material model based on calcified aortic tissue, instead of one based on heavily calcified femoral tissue, to represent diseased femoral arterial vessels results in a 487 fold increase in maximum principal stress within the plaque at a depth of 0.8 mm from the lumen. Conclusions Large differences are induced on numerical results as a consequence of employing material models based on aortic plaque, in place of material models based on femoral plaque, to represent a diseased femoral vessel. Due to these large

  2. Clinical viability of carotid plaque strain estimation using B-mode ultrasound image sequences.

    PubMed

    Khan, Amir A; Hecker, Joseph C; Lal, Brajesh K; Sikdar, Siddhartha

    2016-08-01

    It is estimated that approximately 30% of ischemic strokes are caused by rupture of plaque in the carotid artery. Development of techniques focusing on identifying plaques that are vulnerable to rupture is thus indispensable for stroke prevention. Recent studies have demonstrated that motion analysis of plaques from B-mode and RF ultrasound (US) image sequences can be used to estimate plaque strain. However, viability of these methods in a clinical setting, with variable acquisition protocols, has not been demonstrated yet. In this paper, we explore the viability of estimating plaque strain from B-mode US images of asymptomatic patients, acquired in a real clinical setting with different acquisition settings, frame rates, and operators. Our proposed strain measures, shear strain rate entropy and variance, combined with the recently reported maximum absolute shear strain rate, show that the plaques fall into two distinct clusters. Moreover, these clusters show good correlations with plaque echolucency and echogenicity. We conclude that B-mode US imaging is a viable tool for characterizing plaque dynamics in clinical environments. In future studies, we plan to implement this method on multi-center studies for longitudinal monitoring of plaque.

  3. The microscopic network structure of mussel (Mytilus) adhesive plaques

    PubMed Central

    DeMartini, Daniel G.; Waite, J. Herbert

    2015-01-01

    Marine mussels of the genus Mytilus live in the hostile intertidal zone, attached to rocks, bio-fouled surfaces and each other via collagen-rich threads ending in adhesive pads, the plaques. Plaques adhere in salty, alkaline seawater, withstanding waves and tidal currents. Each plaque requires a force of several newtons to detach. Although the molecular composition of the plaques has been well studied, a complete understanding of supra-molecular plaque architecture and its role in maintaining adhesive strength remains elusive. Here, electron microscopy and neutron scattering studies of plaques harvested from Mytilus californianus and Mytilus galloprovincialis reveal a complex network structure reminiscent of structural foams. Two characteristic length scales are observed characterizing a dense meshwork (approx. 100 nm) with large interpenetrating pores (approx. 1 µm). The network withstands chemical denaturation, indicating significant cross-linking. Plaques formed at lower temperatures have finer network struts, from which we hypothesize a kinetically controlled formation mechanism. When mussels are induced to create plaques, the resulting structure lacks a well-defined network architecture, showcasing the importance of processing over self-assembly. Together, these new data provide essential insight into plaque structure and formation and set the foundation to understand the role of plaque structure in stress distribution and toughening in natural and biomimetic materials. PMID:26631333

  4. The microscopic network structure of mussel (Mytilus) adhesive plaques.

    PubMed

    Filippidi, Emmanouela; DeMartini, Daniel G; Malo de Molina, Paula; Danner, Eric W; Kim, Juntae; Helgeson, Matthew E; Waite, J Herbert; Valentine, Megan T

    2015-12-06

    Marine mussels of the genus Mytilus live in the hostile intertidal zone, attached to rocks, bio-fouled surfaces and each other via collagen-rich threads ending in adhesive pads, the plaques. Plaques adhere in salty, alkaline seawater, withstanding waves and tidal currents. Each plaque requires a force of several newtons to detach. Although the molecular composition of the plaques has been well studied, a complete understanding of supra-molecular plaque architecture and its role in maintaining adhesive strength remains elusive. Here, electron microscopy and neutron scattering studies of plaques harvested from Mytilus californianus and Mytilus galloprovincialis reveal a complex network structure reminiscent of structural foams. Two characteristic length scales are observed characterizing a dense meshwork (approx. 100 nm) with large interpenetrating pores (approx. 1 µm). The network withstands chemical denaturation, indicating significant cross-linking. Plaques formed at lower temperatures have finer network struts, from which we hypothesize a kinetically controlled formation mechanism. When mussels are induced to create plaques, the resulting structure lacks a well-defined network architecture, showcasing the importance of processing over self-assembly. Together, these new data provide essential insight into plaque structure and formation and set the foundation to understand the role of plaque structure in stress distribution and toughening in natural and biomimetic materials.

  5. A computational fluid-structure interaction model for plaque vulnerability assessment in atherosclerotic human coronary arteries

    NASA Astrophysics Data System (ADS)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza; Haghpanahi, Mohammad

    2014-04-01

    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.

  6. Fluorescence lifetime imaging microscopy for the characterization of atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Phipps, Jennifer; Sun, Yinghua; Saroufeem, Ramez; Hatami, Nisa; Marcu, Laura

    2009-02-01

    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 in one measurement the composition within a volume of 4 mm diameter x 250 µm 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.

  7. Challenges on the frontier of intracoronary imaging: atherosclerotic plaque macrophage measurement by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Tanaka, Atsushi; Tearney, Guillermo J.; Bouma, Brett E.

    2010-01-01

    Cellularity of the fibrous caps of coronary atheromas, manifested by the infiltration of macrophages (average size, 20 to 30 μm), is thought to weaken the structural integrity of the cap and predispose plaques to rupture. Therefore, an imaging technology capable of identifying macrophages within fibroatheroma caps in patients could provide valuable information for assessing plaque rupture risk. Recently, intravascular optical coherence tomography (OCT), a high-resolution coronary imaging modality, with an axial resolution of ~10 μm, has been introduced into the clinical setting. OCT images of the microstructure of the coronary artery wall enable accurate plaque-type characterization, supported by histopathological comparison data. Because of its high resolution, OCT may also be used to identify macrophages in vivo. In this paper we review recent developments in OCT for measuring macrophages in atherosclerotic plaques.

  8. Clinical and Pathological Insights into the Dynamic Nature of the White Matter Multiple Sclerosis Plaque

    PubMed Central

    Frischer, Josa M.; Weigand, Stephen D.; Guo, Yong; Kale, Nilufer; Parisi, Joseph E.; Pirko, Istvan; Mandrekar, Jay; Bramow, Stephan; Metz, Imke; Brück, Wolfgang; Lassmann, Hans; Lucchinetti, Claudia F.

    2015-01-01

    Background An extensive analysis of white matter plaques in a large sample of MS autopsies provides insights into the dynamic nature of MS pathology. Methods 120 MS cases (1220 tissue blocks) were included. Plaque types were classified according to demyelinating activity based on stringent criteria. Early-active, late-active, smoldering, inactive, and shadow plaques were distinguished. 2476 MS white matter plaques were identified. Plaque type distribution was analyzed in relation to clinical data. Findings Active plaques were most often found in early disease, whereas at later stages, smoldering, inactive and shadow plaques predominated. The presence of early-active plaques rapidly declined with disease duration. Plaque type distribution differed significantly by clinical course. The majority of plaques in acute-monophasic and RRMS were active. Among SPMS cases with attacks, all plaque types could be distinguished including active plaques, in contrast to SPMS without attacks in whom inactive plaques predominated. Smoldering plaques were frequently and almost exclusively found in progressive MS. At 47-years of age, an equilibrium was observed between active and inactive plaques, whereas smoldering plaques began to peak. Men displayed a higher proportion of smoldering plaques. Interpretation Disease duration, clinical course, age and gender contribute to the dynamic nature of white matter MS pathology. Active MS plaques predominate in acute and early RRMS and are the likely substrate of clinical attacks. Progressive MS transitions to an accumulation of smoldering plaques characterized by microglial activation and slow expansion of pre-existing plaques. Whether current MS therapeutics impact this pathological driver of disease progression remains uncertain. PMID:26239536

  9. Preclinical models of atherosclerosis. The future of Hybrid PET/MR technology for the early detection of vulnerable plaque.

    PubMed

    Cuadrado, Irene; Saura, Marta; Castejón, Borja; Martin, Ana María; Herruzo, Irene; Balatsos, Nikolaos; Zamorano, Jose Luis; Zaragoza, Carlos

    2016-04-08

    Cardiovascular diseases are the leading cause of death in developed countries. The aetiology is currently multifactorial, thus making them very difficult to prevent. Preclinical models of atherothrombotic diseases, including vulnerable plaque-associated complications, are now providing significant insights into pathologies like atherosclerosis, and in combination with the most recent advances in new non-invasive imaging technologies, they have become essential tools to evaluate new therapeutic strategies, with which can forecast and prevent plaque rupture. Positron emission tomography (PET)/computed tomography imaging is currently used for plaque visualisation in clinical and pre-clinical cardiovascular research, albeit with significant limitations. However, the combination of PET and magnetic resonance imaging (MRI) technologies is still the best option available today, as combined PET/MRI scans provide simultaneous data acquisition together with high quality anatomical information, sensitivity and lower radiation exposure for the patient. The coming years may represent a new era for the implementation of PET/MRI in clinical practice, but first, clinically efficient attenuation correction algorithms and research towards multimodal reagents and safety issues should be validated at the preclinical level.

  10. Aetiology of pleural plaques

    PubMed Central

    Rous, V.; Studeny, J.

    1970-01-01

    Pleural plaques were found in 644 (6·6%) of 9,760 photofluorograms taken in 1965 in a region of Pelhřimov district; the incidence was highest in the age group 66-70 years. The advanced age of those affected may be explained by the greater frequency of the causative agent in the past. The disorder was known in Pelhřimov district as early as 1930; it was then thought to be posttuberculous. The past history of the cases was uninformative; as a rule, the only common previous disease was pleurisy with effusion, occurring in 9·7%. The general condition of those affected was excellent; only 8% were aware of the fact that pleural lesions were present. The disorder was found mainly in farmers, familial incidence was common, and if two generations of one family suffered from the condition, the older generation was affected in 100%. Pleural plaques consist morphologically of limited areas of hyalinized collagenous connective tissue with calcium salt deposits. Tubercle bacilli could not be cultivated from the lesions. Mineralological analysis showed no evidence of silicates in the pleural plaques and a normal content in the lungs. The aetiological factor responsible for the development of pleural plaques in Pelhřimov district is not known, but asbestos cannot be implicated. The unknown noxious agent is carried to the pleura by the lymph and blood stream. Pleural plaques are an endemic disorder. The traditional view that lesions are post-tuberculous appears, in the region submitted to this study, to be a possible explanation. Images PMID:5465601

  11. Relationship of MMP-14 and TIMP-3 Expression with Macrophage Activation and Human Atherosclerotic Plaque Vulnerability

    PubMed Central

    Johnson, Jason L.; Jenkins, Nicholas P.; Huang, Wei-Chun; Sala-Newby, Graciela B.; Scholtes, Vincent P. W.; Moll, Frans L.; Pasterkamp, Gerard; Newby, Andrew C.

    2014-01-01

    Matrix metalloproteinase-14 (MMP-14) promotes vulnerable plaque morphology in mice, whereas tissue inhibitor of metalloproteinases-3 (TIMP-3) overexpression is protective. MMP-14hi  TIMP-3lo rabbit foam cells are more invasive and more prone to apoptosis than MMP-14lo  TIMP-3hi cells. We investigated the implications of these findings for human atherosclerosis. In vitro generated macrophages and foam-cell macrophages, together with atherosclerotic plaques characterised as unstable or stable, were examined for expression of MMP-14, TIMP-3, and inflammatory markers. Proinflammatory stimuli increased MMP-14 and decreased TIMP-3 mRNA and protein expression in human macrophages. However, conversion to foam-cells with oxidized LDL increased MMP-14 and decreased TIMP-3 protein, independently of inflammatory mediators and partly through posttranscriptional mechanisms. Within atherosclerotic plaques, MMP-14 was prominent in foam-cells with either pro- or anti-inflammatory macrophage markers, whereas TIMP-3 was present in less foamy macrophages and colocalised with CD206. MMP-14 positive macrophages were more abundant whereas TIMP-3 positive macrophages were less abundant in plaques histologically designated as rupture prone. We conclude that foam-cells characterised by high MMP-14 and low TIMP-3 expression are prevalent in rupture-prone atherosclerotic plaques, independent of pro- or anti-inflammatory activation. Therefore reducing MMP-14 activity and increasing that of TIMP-3 could be valid therapeutic approaches to reduce plaque rupture and myocardial infarction. PMID:25301980

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

    PubMed Central

    Fumagalli, Stefano; Perego, Carlo; Zangari, Rosalia; De Blasio, Daiana; Oggioni, Marco; De Nigris, Francesca; Snider, Francesco; Garred, Peter; Ferrante, Angela M. R.; De Simoni, Maria-Grazia

    2017-01-01

    Inflammatory mechanisms may be involved in atherosclerotic plaque rupture. By using a novel histology-based method to quantify plaque instability here, we assess whether lectin pathway (LP) of complement activation, a major inflammation arm, could represent an index of plaque instability. Plaques from 42 consecutive patients undergoing carotid endarterectomy were stained with hematoxylin-eosin and the lipid core, cholesterol clefts, hemorrhagic content, thickness of tunica media, and intima, including or not infiltration of cellular debris and cholesterol, were determined. The presence of ficolin-1, -2, and -3 and mannose-binding lectin (MBL), LP initiators, was assessed in the plaques by immunofluorescence and in plasma by ELISA. LP activation was assessed in plasma by functional in vitro assays. Patients presenting low stenosis (≤75%) had higher hemorrhagic content than those with high stenosis (>75%), indicating increased erosion. Increased hemorrhagic content and tunica media thickness, as well as decreased lipid core and infiltrated content were associated with vulnerable plaques and therefore used to establish a plaque vulnerability score that allowed to classify patients according to plaque vulnerability. Ficolins and MBL were found both in plaques’ necrotic core and tunica media. Patients with vulnerable plaques showed decreased plasma levels and intraplaque deposition of ficolin-2. Symptomatic patients experiencing a transient ischemic attack had lower plasma levels of ficolin-1. We show that the LP initiators are present within the plaques and their circulating levels change in atherosclerotic patients. In particular, we show that decreased ficolin-2 levels are associated with rupture-prone vulnerable plaques, indicating its potential use as marker for cardiovascular risk assessment in atherosclerotic patients. PMID:28360913

  13. Self-Rupturing Hermetic Valve

    NASA Technical Reports Server (NTRS)

    Tucker, Curtis E., Jr.; Sherrit, Stewart

    2011-01-01

    For commercial, military, and aerospace applications, low-cost, small, reliable, and lightweight gas and liquid hermetically sealed valves with post initiation on/off capability are highly desirable for pressurized systems. Applications include remote fire suppression, single-use system-pressurization systems, spacecraft propellant systems, and in situ instruments. Current pyrotechnic- activated rupture disk hermetic valves were designed for physically larger systems and are heavy and integrate poorly with portable equipment, aircraft, and small spacecraft and instrument systems. Additionally, current pyrotechnically activated systems impart high g-force shock loads to surrounding components and structures, which increase the risk of damage and can require additional mitigation. The disclosed mechanism addresses the need for producing a hermetically sealed micro-isolation valve for low and high pressure for commercial, aerospace, and spacecraft applications. High-precision electrical discharge machining (EDM) parts allow for the machining of mated parts with gaps less than a thousandth of an inch. These high-precision parts are used to support against pressure and extrusion, a thin hermetically welded diaphragm. This diaphragm ruptures from a pressure differential when the support is removed and/or when the plunger is forced against the diaphragm. With the addition of conventional seals to the plunger and a two-way actuator, a derivative of this design would allow nonhermetic use as an on/off or metering valve after the initial rupturing of the hermetic sealing disk. In addition, in a single-use hermetically sealed isolation valve, the valve can be activated without the use of potential leak-inducing valve body penetrations. One implementation of this technology is a high-pressure, high-flow-rate rupture valve that is self-rupturing, which is advantageous for high-pressure applications such as gas isolation valves. Once initiated, this technology is self

  14. Glass rupture disk

    DOEpatents

    Glass, S. Jill; Nicolaysen, Scott D.; Beauchamp, Edwin K.

    2002-01-01

    A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

  15. Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging

    NASA Astrophysics Data System (ADS)

    Doherty, Joshua Ryan

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

  16. Spectroscopy to improve identification of vulnerable plaques in cardiovascular disease.

    PubMed

    Bruggink, Janneke L M; Meerwaldt, Robbert; van Dam, Gooitzen M; Lefrandt, Joop D; Slart, Riemer H J A; Tio, René A; Smit, Andries J; Zeebregts, Clark J

    2010-01-01

    Many apparent healthy persons die from cardiovascular disease, despite major advances in prevention and treatment of cardiovascular disease. Traditional cardiovascular risk factors are able to predict cardiovascular events in the long run, but fail to assess current disease activity or nearby cardiovascular events. There is a clear relation between the occurrence of cardiovascular events and the presence of so-called vulnerable plaques. These vulnerable plaques are characterized by active inflammation, a thin cap and a large lipid pool. Spectroscopy is an optical imaging technique which depicts the interaction between light and tissues, and thereby shows the biochemical composition of tissues. In recent years, impressive advances have been made in spectroscopy technology and intravascular spectroscopy is able to assess the composition of plaques of interest and thereby to identify and actually quantify plaque vulnerability. This review summarizes the current evidence for spectroscopy as a measure of plaque vulnerability and discusses the potential role of intravascular spectroscopic imaging techniques.

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

    PubMed Central

    2015-01-01

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

  18. The effects of plaque morphology and material properties on peak cap stress in human coronary arteries.

    PubMed

    Akyildiz, Ali C; Speelman, Lambert; Nieuwstadt, Harm A; van Brummelen, Harald; Virmani, Renu; van der Lugt, Aad; van der Steen, Anton F W; Wentzel, Jolanda J; Gijsen, Frank J H

    2016-01-01

    Heart attacks are often caused by rupture of caps of atherosclerotic plaques in coronary arteries. Cap rupture occurs when cap stress exceeds cap strength. We investigated the effects of plaque morphology and material properties on cap stress. Histological data from 77 coronary lesions were obtained and segmented. In these patient-specific cross sections, peak cap stresses were computed by using finite element analyses. The finite element analyses were 2D, assumed isotropic material behavior, and ignored residual stresses. To represent the wide spread in material properties, we applied soft and stiff material models for the intima. Measures of geometric plaque features for all lesions were determined and their relations to peak cap stress were examined using regression analyses. Patient-specific geometrical plaque features greatly influence peak cap stresses. Especially, local irregularities in lumen and necrotic core shape as well as a thin intima layer near the shoulder of the plaque induce local stress maxima. For stiff models, cap stress increased with decreasing cap thickness and increasing lumen radius (R = 0.79). For soft models, this relationship changed: increasing lumen radius and increasing lumen curvature were associated with increased cap stress (R = 0.66). The results of this study imply that not only accurate assessment of plaque geometry, but also of intima properties is essential for cap stress analyses in atherosclerotic plaques in human coronary arteries.

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

    PubMed

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

    2016-06-01

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

  20. A Voxel-Map Quantitative Analysis Approach for Atherosclerotic Noncalcified Plaques of the Coronary Artery Tree

    PubMed Central

    Li, Ying; Chen, Wei; Chen, Yonglin; Chu, Chun; Fang, Bingji; Tan, Liwen

    2013-01-01

    Noncalcified plaques (NCPs) are associated with the presence of lipid-core plaques that are prone to rupture. Thus, it is important to detect and monitor the development of NCPs. Contrast-enhanced coronary Computed Tomography Angiography (CTA) is a potential imaging technique to identify atherosclerotic plaques in the whole coronary tree, but it fails to provide information about vessel walls. In order to overcome the limitations of coronary CTA and provide more meaningful quantitative information for percutaneous coronary intervention (PCI), we proposed a Voxel-Map based on mathematical morphology to quantitatively analyze the noncalcified plaques on a three-dimensional coronary artery wall model (3D-CAWM). This approach is a combination of Voxel-Map analysis techniques, plaque locating, and anatomical location related labeling, which show more detailed and comprehensive coronary tree wall visualization. PMID:24348749

  1. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

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

  2. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre les schémas thérapeutiques et les résultats des traitements pour la pelade par plaques, de même que les aider à identifier les patients pour qui une demande de consultation en dermatologie pourrait s’imposer. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant le traitement de la pelade par plaques. Message principal La pelade par plaques est une forme auto-immune de perte pileuse qui touche à la fois les enfants et les adultes. Même s’il n’y a pas de mortalité associée à la maladie, la morbidité découlant des effets psychologiques de la perte des cheveux peut être dévastatrice. Lorsque la pelade par plaques et le sous-type de la maladie sont identifiés, un schéma thérapeutique approprié peut être amorcé pour aider à arrêter la chute des cheveux et possiblement faire commencer la repousse. Les traitements de première intention sont la triamcinolone intralésionnelle avec des corticostéroïdes topiques ou du minoxidil ou les 2. Les médecins de famille peuvent prescrire ces traitements en toute sécurité et amorcer ces thérapies. Les cas plus avancés ou réfractaires pourraient avoir besoin de diphénylcyclopropénone topique ou d’anthraline topique. On peut traiter la perte de cils avec des analogues de la prostaglandine. Les personnes ayant subi une perte de cheveux abondante peuvent recourir à des options de camouflage ou à des prothèses capillaires. Il est important de surveiller les troubles psychiatriques en raison des effets psychologiques profonds de la perte de cheveux. Conclusion Les médecins de famille verront de nombreux patients qui perdent leurs cheveux. La reconnaissance de la pelade par plaques et la compréhension du processus pathologique sous-jacent permettent d’amorcer un schéma thérapeutique approprié. Les cas plus graves ou r

  3. Directional spatial frequency analysis of lipid distribution in atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  4. Local Inhibition of Macrophage and Smooth Muscle Cell Proliferation to Suppress Plaque Progression

    PubMed Central

    Sukhovershin, Roman A.; Toledano Furman, Naama E.; Tasciotti, Ennio; Trachtenberg, Barry H.

    2016-01-01

    Atherosclerosis is a complex process responsible for a major burden of cardiovascular morbidity and mortality. Macrophages and smooth muscle cells (SMCs) are abundant within atherosclerotic plaques. This review discusses the role of macrophages and SMCs in plaque progression and provides an overview of nanoparticle-based approaches and other current methods for local targeting of atherosclerotic plaques. PMID:27826367

  5. Multimodal spectroscopy detects features of vulnerable atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

    Early detection and treatment of rupture-prone vulnerable atherosclerotic plaques is critical to reducing patient mortality associated with cardiovascular disease. The combination of reflectance, fluorescence, and Raman spectroscopy-termed multimodal spectroscopy (MMS)-provides detailed biochemical information about tissue and can detect vulnerable plaque features: thin fibrous cap (TFC), necrotic core (NC), superficial foam cells (SFC), and thrombus. Ex vivo MMS spectra are collected from 12 patients that underwent carotid endarterectomy or femoral bypass surgery. Data are collected by means of a unitary MMS optical fiber probe and a portable clinical instrument. Blinded histopathological analysis is used to assess the vulnerability of each spectrally evaluated artery lesion. Modeling of the ex vivo MMS spectra produce objective parameters that correlate with the presence of vulnerable plaque features: TFC with fluorescence parameters indicative of collagen presence; NC/SFC with a combination of diffuse reflectance β-carotene/ceroid absorption and the Raman spectral signature of lipids; and thrombus with its Raman signature. Using these parameters, suspected vulnerable plaques can be detected with a sensitivity of 96% and specificity of 72%. These encouraging results warrant the continued development of MMS as a catheter-based clinical diagnostic technique for early detection of vulnerable plaques.

  6. F-18 Fluoride Positron Emission Tomography-Computed Tomography for Detecting Atherosclerotic Plaques.

    PubMed

    Kang, Won Jun

    2015-01-01

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

  7. A finite element study of balloon expandable stent for plaque and arterial wall vulnerability assessment

    NASA Astrophysics Data System (ADS)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

    2014-07-01

    The stresses induced within plaque tissues and arterial layers during stent expansion inside an atherosclerotic artery can be exceeded from the yield stresses of those tissues and, consequently, lead to plaque or arterial layer rupture. The distribution and magnitude of the stresses in each component involved in stenting might be clearly different for different plaque types and different arterial layers. In this study, a nonlinear finite element simulation was employed to investigate the effect of plaque composition (calcified, cellular, and hypocellular) on the stresses induced in the arterial layers (intima, media, and adventitia) during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal/healthy arterial tissues on its outer side. The results indicated a significant influence of plaque types on the maximum stresses induced within the plaque wall and arterial layers during stenting but not when computing maximum stress on the stent. The stress on the stiffest calcified plaque wall was in the fracture level (2.38 MPa), whereas cellular and hypocellular plaques remain stable owing to less stress on their walls. Regardless of plaque types, the highest von Mises stresses were observed on the stiffest intima layer, whereas the lowest stresses were seen to be located in less stiff media layer. The computed stresses on the intima layer were found to be high enough to initiate a rupture in this stiff layer. These findings suggest a higher risk of arterial vascular injury for the intima layer, while a lower risk of arterial injury for the media and adventitia layers.

  8. Macrophage-targeted photodynamic detection of vulnerable atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Hamblin, Michael R.; Tawakol, Ahmed; Castano, Ana P.; Gad, Faten; Zahra, Touqir; Ahmadi, Atosa; Stern, Jeremy; Ortel, Bernhard; Chirico, Stephanie; Shirazi, Azadeh; Syed, Sakeena; Muller, James E.

    2003-06-01

    Rupture of a vulnerable atherosclerotic plaque (VP) leading to coronary thrombosis is the chief cause of sudden cardiac death. VPs are angiographically insignificant lesions, which are excessively inflamed and characterized by dense macrophage infiltration, large necrotic lipid cores, thin fibrous caps, and paucity of smooth muscle cells. We have recently shown that chlorin(e6) conjugated with maleylated albumin can target macrophages with high selectivity via the scavenger receptor. We report the potential of this macrophage-targeted fluorescent probe to localize in VPs in a rabbit model of atherosclerosis, and allow detection and/or diagnosis by fluorescence spectroscopy or imaging. Atherosclerotic lesions were induced in New Zealand White rabbit aortas by balloon injury followed by administration of a high-fat diet. 24-hours after IV injection of the conjugate into atherosclerotic or normal rabbits, the animals were sacrificed, and aortas were removed, dissected and examined for fluorescence localization in plaques by fiber-based spectrofluorimetry and confocal microscopy. Dye uptake within the aortas was also quantified by fluorescence extraction of samples from aorta segments. Biodistribution of the dye was studied in many organs of the rabbits. Surface spectrofluorimetry after conjugate injection was able to distinguish between plaque and adjacent aorta, between atherosclerotic and normal aorta, and balloon-injured and normal iliac arteries with high significance. Discrete areas of high fluorescence (up to 20 times control were detected in the balloon-injured segments, presumably corresponding to macrophage-rich plaques. Confocal microscopy showed red ce6 fluorescence localized in plaques that showed abundant foam cells and macrophages by histology. Extraction data on aortic tissue corroborated the selectivity of the conjugate for plaques. These data support the strategy of employing macrophage-targeted fluorescent dyes to detect VP by intravascular

  9. Ruptured abdominal aortic aneurysm.

    PubMed

    Sachs, T; Schermerhorn, M

    2010-06-01

    Ruptured abdominal aortic aneurysm (AAA) continues to be one of the most lethal vascular pathologies we encounter. Its management demands prompt and efficient evaluation and repair. Open repair has traditionally been the mainstay of treatment. However, the introduction of endovascular techniques has altered the treatment algorithm for ruptured AAA in most major medical centers. We present recent literature and techniques for ruptured AAA and its surgical management.

  10. Non-pulsed electrochemical impregnation of flexible metallic battery plaques

    DOEpatents

    Maskalick, Nicholas J.

    1982-01-01

    A method of loading active battery material into porous, flexible, metallic battery plaques, comprises the following steps: precipitating nickel hydroxide active material within the plaque, by making the plaque cathodic, at a high current density, in an electro-precipitation cell also containing a consumable nickel anode and a solution comprising nickel nitrate, having a pH of between 2.0 and 2.8; electrochemically oxidizing the precipitate in caustic formation solution; and repeating the electro-precipitation step at a low current density.

  11. Chronic intermittent mental stress promotes atherosclerotic plaque vulnerability, myocardial infarction and sudden death in mice.

    PubMed

    Roth, Lynn; Rombouts, Miche; Schrijvers, Dorien M; Lemmens, Katrien; De Keulenaer, Gilles W; Martinet, Wim; De Meyer, Guido R Y

    2015-09-01

    Vulnerable atherosclerotic plaques are prone to plaque rupture leading to acute cardiovascular syndromes and death. Elucidating the risk of plaque rupture is important to define better therapeutic or preventive strategies. In the present study, we investigated the effect of chronic intermittent mental stress on atherosclerotic plaque stability and cardiovascular mortality in apolipoprotein E-deficient (ApoE(-/-)) mice with a heterozygous mutation in the fibrillin-1 gene (Fbn1(C1039G+/)(-)). This mouse model displays exacerbated atherosclerosis with spontaneous plaque ruptures, myocardial infarction and sudden death, when fed a Western-type diet (WD). Female ApoE(-/-)Fbn1(C1039G+/-) mice were fed a WD for up to 25 weeks. After 10 weeks WD, mice were divided in a control (n = 27) and mental stress (n = 29) group. The chronic intermittent mental stress protocol consisted of 3 triggers: water avoidance, damp bedding and restraint stress, in a randomly assigned order lasting 6 h every weekday for 15 weeks. Chronic intermittent mental stress resulted in a significant increase in the amount of macrophages in atherosclerotic plaques of the proximal ascending aorta, whereas type I collagen and fibrous cap thickness were decreased. The coronary arteries of mental stress-treated mice showed larger plaques, more stenosis, and an increased degree of perivascular fibrosis. Moreover, myocardial infarctions occurred more frequently in the mental stress group. As compared to the control group, the survival of stressed ApoE(-/-)Fbn1(C1039G+/-) mice decreased from 67% to 52% at 25 weeks WD, presumably due to myocardial infarctions. In conclusion, chronic intermittent mental stress promotes plaque instability, myocardial infarctions, and mortality of ApoE(-/-)Fbn1(C1039G+/-) mice.

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

    PubMed Central

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

    2016-01-01

    Plaque rupture is the critical cause of cardiovascular thrombosis, but the detailed mechanisms are not fully understood. Recent studies have found abundant cholesterol crystals in ruptured plaques, and it has been proposed that the rapid expansion of cholesterol crystals in a limited space during crystallization may contribute to plaque rupture. To evaluate the effect of cholesterol crystal growth on atherosclerotic plaques, we modeled the expansion of cholesterol crystals during the crystallization process in the necrotic core and estimated the stress on the thin cap with different arrangements of cholesterol crystals. We developed a two-dimensional finite element method model of atherosclerotic plaques containing expanding cholesterol crystals and investigated the effect of the magnitude and distribution of crystallization on the peak circumferential stress born by the cap. Using micro-optical coherence tomography (μOCT), we extracted the cross-sectional geometric information of cholesterol crystals in human atherosclerotic aorta tissue ex vivo and applied the information to the model. The results demonstrate that (1) the peak circumference stress is proportionally dependent on the cholesterol crystal growth; (2) cholesterol crystals at the cap shoulder impose the highest peak circumference stress; and (3) spatial distributions of cholesterol crystals have a significant impact on the peak circumference stress: evenly distributed cholesterol crystals exert less peak circumferential stress on the cap than concentrated crystals. PMID:27149381

  13. Bilateral Patellar Tendon Rupture

    DTIC Science & Technology

    2009-07-01

    within the tendon or systemic disorders such as lupus erythematosus , diabetes mellitus, chronic kidney disease, rheumatologic disease, and local or...factors for patellar tendon rupture include obesity, male gender, age 30-40, activities that increase patellar stress, systemic lupus erythematosus ...patellar tendon rupture is a rare occurrence usually associated with chronic degeneration of tendon fibers, use of steroids, or systemic illness. Our

  14. Influence of Cigarette Smoking on Burden and Characteristics of Coronary Artery Plaques in Chinese Men

    PubMed Central

    Sun, Yujiao; Yu, Xin; Zhi, Ying; Geng, Song; Li, Hua; Liu, Ting; Xu, Ke; Qi, Guoxian

    2015-01-01

    Background It is generally well-known that smoking has a substantial impact on general health, and cardiovascular health in particular. The purpose of this study was to analyze the effects of different smoking status on the burden and characteristics of coronary artery plaques in Chinese men. Methods Our study enrolled 1920 individuals with suspected coronary artery disease undergoing 256-detector-row computed tomography scan after clinical assessment. These study participants were stratified into three groups: never smoker, current smoker, and former smoker, according to their smoking status. Thereafter, the associations of different smoking status with the coronary artery plaques were assessed using both univariable and multivariable logistic regression. Results The prevalences of any plaque, significant stenosis and coronary artery calcium score (CACS) ≥ 10 were highest in the current smokers (all p < 0.05). The proportion of calcified plaques was the lowest and the prevalence of non-calcified plaques was the highest in current smokers (p = 0.004). The higher pack-years group had significantly elevated percentages of any plaque, significant stenosis, ≥ 2/LM vessel disease and CACS ≥ 10 than the lower pack-years group (all p < 0.001). The percent of calcified plaques was lower and the percent of non-calcified plaques was higher in the higher (> 20) pack-years group than in the lower pack-years group (≤ 20) (p = 0.024). Current smoking with higher pack-years was the independent risk factor for any plaque, significant stenosis, CACS ≥ 10, non-calcified and mixed plaques (all p < 0.05) after multivariate adjustments. Conclusions The current smokers had the most serious burden of coronary artery plaques and the highest percentage of non-calcified plaques. Current smoking with higher pack-years was a significant risk factor for coronary artery plaque burden and non-calcified and mixed plaques. PMID:27122899

  15. The immune response is involved in atherosclerotic plaque calcification: could the RANKL/RANK/OPG system be a marker of plaque instability?

    PubMed

    Montecucco, Fabrizio; Steffens, Sabine; Mach, François

    2007-01-01

    Atherogenesis is characterized by an intense inflammatory process, involving immune and vascular cells. These cells play a crucial role in all phases of atherosclerotic plaque formation and complication through cytokine, protease, and prothrombotic factor secretion. The accumulation of inflammatory cells and thus high amounts of soluble mediators are responsible for the evolution of some plaques to instable phenotype which may lead to rupture. One condition strongly associated with plaque rupture is calcification, a physiopathological process orchestrated by several soluble factors, including the receptor activator of nuclear factor (NF)kappaB ligand (RANKL)/receptor activator of nuclear factor (NF)kappaB (RANK)/osteoprotegerin (OPG) system. Although some studies showed some interesting correlations with acute ischemic events, at present, more evidences are needed to evaluate the predictive and diagnostic value of serum sRANKL and OPG levels for clinical use. The major limitation is probably the poor specificity of these factors for cardiovascular disease. The identification of tissue-specific isoforms could increase the importance of sRANKL and OPG in predicting calcified plaque rupture and the dramatic ischemic consequences in the brain and the heart.

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

    PubMed

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

    2011-04-01

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

  17. Dental plaque identification at home

    MedlinePlus

    ... about 30 seconds. Then rinse your mouth with water and examine your teeth. Any red-stained areas are plaque. A small dental mirror may help you check all areas. The second method uses a plaque light. ... your mouth gently with water. Examine your teeth and gums while shining an ...

  18. Pioneer F Plaque Location

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Pioneer F spacecraft, destined to be the first man made object to escape from the solar system into interstellar space, carries this pictorial plaque. It is designed to show scientifically educated inhabitants of some other star system, who might intercept it millions of years from now, when Pioneer was launched, from where, and by what kind of beings. (Hopefully, any aliens reading the plaque will not use this knowledge to immediately invade Earth.) The design is etched into a 6 inch by 9 inch gold-anodized aluminum plate, attached to the spacecraft's attenna support struts in a position to help shield it from erosion by interstellar dust. The radiating lines at left represents the positions of 14 pulsars, a cosmic source of radio energy, arranged to indicate our sun as the home star of our civilization. The '1-' symbols at the ends of the lines are binary numbers that represent the frequencies of these pulsars at the time of launch of Pioneer F relative of that to the hydrogen atom shown at the upper left with a '1' unity symbol. The hydrogen atom is thus used as a 'universal clock,' and the regular decrease in the frequencies of the pulsars will enable another civilization to determine the time that has elapsed since Pioneer F was launched. The hydrogen is also used as a 'universal yardstick' for sizing the human figures and outline of the spacecraft shown on the right. The hydrogen wavelength, about 8 inches, multiplied by the binary number representing '8' shown next to the woman gives her height, 64 inches. The figures represent the type of creature that created Pioneer. The man's hand is raised in a gesture of good will. Across the bottom are the planets, ranging outward from the Sun, with the spacecraft trajectory arching away from Earth, passing Mars, and swinging by Jupiter.

  19. Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque

    SciTech Connect

    Saba, Luca; Potters, Fons; Lugt, Aad van der; Mallarini, Giorgio

    2010-08-15

    In the last two decades, a substantial number of articles have been published to provide diagnostic solutions for patients with carotid atherosclerotic disease. These articles have resulted in a shift of opinion regarding the identification of stroke risk in patients with carotid atherosclerotic disease. In the recent past, the degree of carotid artery stenosis was the sole determinant for performing carotid intervention (carotid endarterectomy or carotid stenting) in these patients. We now know that the degree of stenosis is only one marker for future cerebrovascular events. If one wants to determine the risk of these events more accurately, other 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.

  20. Making a Lightweight Battery Plaque

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  1. Saliva and dental plaque.

    PubMed

    Rudney, J D

    2000-12-01

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

  2. Disappearance of La Caille Plaque

    NASA Astrophysics Data System (ADS)

    2010-04-01

    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.

  3. Genetic deletion or TWEAK blocking antibody administration reduce atherosclerosis and enhance plaque stability in mice

    PubMed Central

    Sastre, Cristina; Fernández-Laso, Valvanera; Madrigal-Matute, Julio; Muñoz-García, Begoña; Moreno, Juan A; Pastor-Vargas, Carlos; Llamas-Granda, Patricia; Burkly, Linda C; Egido, Jesús; Martín-Ventura, Jose L; Blanco-Colio, Luis M

    2014-01-01

    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

  4. Peridynamic Modeling of Ruptures in Biomembranes

    PubMed Central

    Jesorka, Aldo; Bertoldi, Katia

    2016-01-01

    We simulate the formation of spontaneous ruptures in supported phospholipid double bilayer membranes, using peridynamic modeling. Experiments performed on spreading double bilayers typically show two distinct kinds of ruptures, floral and fractal, which form spontaneously in the distal (upper) bilayer at late stages of double bilayer formation on high energy substrates. It is, however, currently unresolved which factors govern the occurrence of either rupture type. Variations in the distance between the two bilayers, and the occurrence of interconnections (“pinning sites”) are suspected of contributing to the process. Our new simulations indicate that the pinned regions which form, presumably due to Ca2+ ions serving as bridging agent between the distal and the proximal bilayer, act as nucleation sites for the ruptures. Moreover, assuming that the pinning sites cause a non-zero shear modulus, our simulations also show that they change the rupture mode from floral to fractal. At zero shear modulus the pores appear to be circular, subsequently evolving into floral pores. With increasing shear modulus the pore edges start to branch, favoring fractal morphologies. We conclude that the pinning sites may indirectly determine the rupture morphology by contributing to shear stress in the distal membrane. PMID:27829001

  5. Coronary plaque imaging by coronary computed tomography angiography

    PubMed Central

    Sato, Akira

    2014-01-01

    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. PMID:24876919

  6. On the effect of calcification volume and configuration on the mechanical behaviour of carotid plaque tissue.

    PubMed

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

    2016-03-01

    Vascular calcification is a complex molecular process that exhibits a number of relatively characteristic morphology patterns in atherosclerotic plaques. Treatment of arterial stenosis by endovascular intervention, involving forceful circumferential expansion of the plaque, can be unpredictable in calcified lesions. The aim of this study was to determine the mechanical stretching mechanisms and define the mechanical limits for circumferentially expanding carotid plaque lesions under the influence of distinct calcification patterns. Mechanical and structural characterisation was performed on 17 human carotid plaques acquired from patients undergoing endarterectomy procedures. The mechanical properties were determined using uniaxial extension tests that stretch the lesions to complete failure along their circumferential axis. Calcification morphology of mechanically ruptured plaque lesions was characterised using high resolution micro computed tomography imaging. Scanning electron microscopy was used to examine the mechanically induced failure sites and to identify the interface boundary conditions between calcified and non-calcified tissue. The mechanical tests produced four distinct trends in mechanical behaviour which corresponded to the calcification patterns that structurally defined each mechanical group. Each calcification pattern produced unique mechanical restraining effects on the plaque tissue stretching properties evidenced by the variation in degree of stretch to failure. Resistance to failure appears to rely on interactions between calcification and non-calcified tissue. Scanning electron microscopy examination revealed structural gradations at interface boundary conditions to facilitate the transfer of stress. This study emphasises the mechanical influence of distinct calcification configurations on plaque expansion properties and highlights the importance of pre-operative lesion characterisation to optimise treatment outcomes.

  7. Analysis of Cardiovascular Tissue Components for the Diagnosis of Coronary Vulnerable Plaque from Intravascular Ultrasound Images

    PubMed Central

    Hwang, Yoo Na; Kim, Ga Young; Shin, Eun Seok

    2017-01-01

    The purpose of this study was to characterize cardiovascular tissue components and analyze the different tissue properties for predicting coronary vulnerable plaque from intravascular ultrasound (IVUS) images. For this purpose, sequential IVUS image frames were obtained from human coronary arteries using 20 MHz catheters. The plaque regions between the intima and media-adventitial borders were manually segmented in all IVUS images. Tissue components of the plaque regions were classified into having fibrous tissue (FT), fibrofatty tissue (FFT), necrotic core (NC), or dense calcium (DC). The media area and lumen diameter were also estimated simultaneously. In addition, the external elastic membrane (EEM) was computed to predict the vulnerable plaque after the tissue characterization. The reliability of manual segmentation was validated in terms of inter- and intraobserver agreements. The quantitative results found that the FT and the media as well as the NC would be good indicators for predicting vulnerable plaques in IVUS images. In addition, the lumen was not suitable for early diagnosis of vulnerable plaque because of the low significance compared to the other vessel parameters. To predict vulnerable plaque rupture, future study should have additional experiments using various tissue components, such as the EEM, FT, NC, and media.

  8. Chinese Herbal Cardiotonic Pill Stabilizes Vulnerable Plaques in Rabbits by Decreasing the Expression of Adhesion Molecules

    PubMed Central

    Chen, Liang; Li, Xiaonan; Li, Changjiang; Rong, Yuanyuan; Xiao, Yawei; Xu, Xinsheng; Yao, Guihua; Jiang, Guihua

    2016-01-01

    Abstract: The cardiotonic pill (CP), consisting of a mixture of Radix Salviae Miltiorrhizae, Radix Notoginseng, and Borneolum Syntheticum, has been widely used in the prevention and treatment of cardiovascular disease. Adhesion molecules, including intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1, are involved in the development of vulnerable plaque. We investigated the effect of the CP in a rabbit model of vulnerable plaque established by local transfection with p53 gene. Compared with the control group, rabbits with vulnerable plaque showed a significantly lower intima-media thickness and plaque burden after CP treatment for 12 weeks. Moreover, the reduction in rate of plaque rupture and vulnerability index was similar. On enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and immunohistochemistry analysis, the expression of intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 was inhibited with CP treatment. CP treatment could postpone atherosclerotic plaque development and stabilize vulnerable plaque by inhibiting the expression of adhesion molecules in treatment of cardiovascular disease. PMID:27110743

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

    PubMed Central

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

    2013-01-01

    Local hemodynamic forces, such as wall shear stress, are thought to trigger cellular and molecular mechanisms that determine atherosclerotic plaque vulnerability to rupture. Magnetic resonance imaging (MRI) has emerged as a powerful tool to characterize human carotid atherosclerotic plaque composition and morphology, and to identify plaque features shown to be key determinants of plaque vulnerability. Image-based computational fluid dynamics (CFD) has allowed researchers to obtain time-resolved wall shear stress (WSS) information of atherosclerotic carotid arteries. A deeper understanding of the mechanisms of initiation and progression of atherosclerosis can be obtained through the comparison of WSS and plaque composition and morphology. To date, however, advance in knowledge has been limited greatly due to the lack of a reliable infrastructure to perform such analysis. The aim of this study is to establish a framework that will allow for the co-registration and analysis of the three-dimensional (3D) distribution ofWSS and plaque components and morphology. The use of this framework will lead to future studies targeted to determining the role of WSS in atherosclerotic plaque progression and vulnerability. PMID:23945133

  10. A feasibility study of carotid elastography for risk assessment of atherosclerotic plaques validated by magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Pan, Xiaochang; Huang, Lingyun; Huang, Manwei; Zhao, Xihai; He, Le; Yuan, Chun; Bai, Jing; Luo, Jianwen

    2014-03-01

    Stroke is a leading cause of mortality worldwide. One of its main reasons is rupture of carotid atherosclerotic plaques. Conventional B-mode ultrasound images and Doppler/color flow measurements are mostly used to evaluate degree of stenosis, which underestimates plaque vulnerability. Alternatively, the correspondence between multi-contrast magnetic resonance imaging (MRI) features, plaque composition and histology has been well established. In this study, the feasibility of ultrasound carotid elastography in risk assessment of carotid atherosclerotic plaques is investigated. Preliminarily in-vivo results on a small number of human subjects are initially validated by multi-contrast, highresolution MRI, and it shows that maximum strain rate might be feasible to evaluate the plaque vulnerability.

  11. Application of IR and NIR fiber optic imaging in thermographic and spectroscopic diagnosis of atherosclerotic vulnerable plaques: preliminary experience

    NASA Astrophysics Data System (ADS)

    Naghavi, Morteza; Khan, Tania; Gu, Bujin; Soller, Babs R.; Melling, Peter; Asif, Mohammed; Gul, Khawar; Madjid, Mohammad; Casscells, S. W.; Willerson, James T.

    2000-12-01

    Despite major advances in cardiovascular science and technology during the past three decades, approximately half of all myocardial infarctions and sudden deaths occur unexpectedly. It is widely accepted that coronary atherosclerotic plaques and thrombotic complications resulting from their rupture or erosion are the underlying causes of this major health problem. The majority of these vulnerable plaques exhibit active inflammation, a large necrotic lipid core, a thin fibrous cap, and confer a stenosis of less than 70%. These lesions are not detectable by stress testing or coronary angiography. Our group is exploring the possibility of a functional classification based on physiological variables such as plaque temperature, pH, oxygen consumption, lactate production etc. We have shown that heat accurately locates the inflamed plaques. We also demonstrated human atherosclerotic plaques are heterogeneous with regard to pH and hot plaques and are more likely to be acidic. To develop a nonsurgical method for locating the inflamed plaques, we are developing both IR fiber optic imaging and NIR spectroscopic systems in our laboratory to detect hot and acidic plaque in atherosclerotic arterial walls. Our findings introduce the possibility of an isolated/combined IR and NIR fiber optic catheter that can bring new insight into functional assessment of atherosclerotic plaque and thereby detection of active and inflamed lesions responsible for heart attacks and strokes.

  12. Ruptured jejunal artery aneurysm

    PubMed Central

    Costa, Sílvia; Costa, Alexandre; Pereira, Tiago; Maciel, Jorge

    2013-01-01

    Visceral artery aneurysms (VAAs), unlike aortic aneurysms, are very rare, but are also a potentially lethal vascular disease. Jejunal artery aneurysms only account for less than 3% of VAAs, but have a 30% risk of rupture, with 20% death rate, presenting with only few and vague symptoms. We report the case of a 76-year-old man presenting at the emergency department (ED) with a crampy epigastric pain and vomiting. An ultrasound performed diagnosed free abdominal fluid and immediate CT scan diagnosed jejunal artery aneurysm spontaneously rupturing, followed by hypovolaemic shock. Emergent surgery was undertaken, and aneurysmectomy, followed by partial enterectomy with primary anastomosis were performed, because of segmentary jejunal ischaemia. The patient's recovery was unremarkable. High level of suspicion, rapid diagnosis capability and prompt surgical or endovascular intervention, as well as an effective teamwork in the ED are critical to avoid the devastating consequences of ruptured VAAs. PMID:23771962

  13. Arachnoid cyst spontaneous rupture.

    PubMed

    Marques, Inês Brás; Vieira Barbosa, José

    2014-01-01

    Arachnoid cysts are benign congenital cerebrospinal fluid collections, usually asymptomatic and diagnosed incidentally in children or adolescents. They may become symptomatic after enlargement or complications, frequently presenting with symptoms of intracranial hypertension. We report an unusual case of progressive refractory headache in an adult patient due to an arachnoid cyst spontaneous rupture. Although clinical improvement occurred with conservative treatment, the subdural hygroma progressively enlarged and surgical treatment was ultimately needed. Spontaneous rupture is a very rare complication of arachnoid cysts. Accumulation of cerebrospinal fluid accumulation in the subdural space causes sustained intracranial hypertension that may be life-threatening and frequently requires surgical treatment. Patients with arachnoid cysts must be informed on their small vulnerability to cyst rupture and be aware that a sudden and severe headache, especially if starting after minor trauma or a Valsalva manoeuvre, always requires medical evaluation.

  14. Automatic plaque assay for the pharmaceutical industry using machine vision

    NASA Astrophysics Data System (ADS)

    Wilder, Joseph; Tsai, Augustine; Festa, J. M.

    1995-10-01

    A crucial step in the manufacture of vaccines is the verification of their potency. An assay of the potency must be carried out on every batch produced to determine the safety and efficacy of the vaccine. Currently, human inspectors count the number of plaques (holes) in a cell layer in a petri dish to estimate the potency.They must determine whether nearby plaques that have overgrown each other's borders are single or multiple plaques and distinguish between plaques and small tears in the cell layer resulting from the processing operations (the edges of tears differ in appearance from the edges of plaques). Because of the judgments required to make these subtle distinctions, human inspectors are inconsistent. In cooperation with Merck & Co., Inc., the Rutgers University Center for Computer Aids for Industrial Productivity has demonstrated the feasibility of achieving consistent automatic counting of plaques by a prototype intelligent machine vision system. The David Sarnoff Research Center developed materials handling equipment and factory information system interfaces to enable this prototype system to be installed in a quality control facility at Merck. This paper describes the overall operation of the machine vision aspects of the system, including optics, illumination, sensing, preprocessing, feature extraction and shape recognition. Results of initial tests of the system are also reported.

  15. Ruptured intracranial dermoid cyst.

    PubMed

    Oursin, C; Wetzel, S G; Lyrer, P; Bächli, H; Stock, K W

    1999-09-01

    Intradural dermoids are rare congenital tumors representing approximately 0.05% of all intracranial lesions. These benign tumors have a typical appearance on CT and MR due to their lipid components. The complication caused by rupture are the spillage of the fatty material into the cerebrospinal fluid. We report a case of a ruptured dermoid cyst showing fat/fluid levels in both side ventricles and fatty material in the subarachnoid space on CT and MR-imaging and the follow-up over four years after incomplete resection of the tumor.

  16. Identification of High-Risk Plaques by MRI and Fluorescence Imaging in a Rabbit Model of Atherothrombosis

    PubMed Central

    Hua, Ning; Baik, Fred; Pham, Tuan; Phinikaridou, Alkystis; Giordano, Nick; Friedman, Beth; Whitney, Michael; Nguyen, Quyen T.; Tsien, Roger Y.; Hamilton, James A.

    2015-01-01

    Introduction The detection of atherosclerotic plaques at risk for disruption will be greatly enhanced by molecular probes that target vessel wall biomarkers. Here, we test if fluorescently-labeled Activatable Cell Penetrating Peptides (ACPPs) could differentiate stable plaques from vulnerable plaques that disrupt, forming a luminal thrombus. Additionally, we test the efficacy of a combined ACPP and MRI technique for identifying plaques at high risk of rupture. Methods and Results In an atherothrombotic rabbit model, disrupted plaques were identified with in vivo MRI and co-registered in the same rabbit aorta with the in vivo uptake of ACPPs, cleaved by matrix metalloproteinases (MMPs) or thrombin. ACPP uptake, mapped ex vivo in whole aortas, was higher in disrupted compared to non-disrupted plaques. Specifically, disrupted plaques demonstrated a 4.5~5.0 fold increase in fluorescence enhancement, while non-disrupted plaques showed only a 2.2~2.5 fold signal increase. Receiver operating characteristic (ROC) analysis indicates that both ACPPs (MMP and thrombin) show high specificity (84.2% and 83.2%) and sensitivity (80.0% and 85.7%) in detecting disrupted plaques. The detection power of ACPPs was improved when combined with the MRI derived measure, outward remodeling ratio. Conclusions Our targeted fluorescence ACPP probes distinguished disrupted plaques from stable plaques with high sensitivity and specificity. The combination of anatomic, MRI-derived predictors for disruption and ACPP uptake can further improve the power for identification of high-risk plaques and suggests future development of ACPPs with molecular MRI as a readout. PMID:26448434

  17. Association between renal dysfunction and the mixed plaque of coronary artery on computed tomographic angiography.

    PubMed

    Sung, Jiyoon; Chang, Jae Hyun; Chung, Wook-Jin; Jung, Ji Yong; Na, Sun Young; Lee, Hyun Hee; Sung, Yon Mi; Moon, Chan Il; Hwang, Young-Hwan; Chung, Wookyung; Kim, Sejoong

    2011-01-01

    Coronary artery plaque is related to development of coronary artery disease (CAD), and chronic kidney disease is associated with CAD. However, the association of renal dysfunction (RD) with coronary artery plaque characteristics has not been fully elucidated. We evaluated the association between RD and coronary artery plaque characteristics in patients with suspected CAD, who underwent multislice computed tomographic angiography (CTA). A total of 918 patients were classified into 4 groups: group with no plaque (NP) (48.9%), group with calcified plaque (CP) (16.0%), group with noncalcified plaque (NCP) (22.4%), and group with mixed plaque (MP) (12.7%). NCP is considered as rupture-prone soft plaque, and CP as more stable lesion. The mean of estimated glomerular filtration rate (eGFR) was 82.5 ± 15.4 mL/min/1.73 m(2), and the prevalence of RD (defined as eGFR < 60 mL/min/1.73 m(2)) was 6.3%. The prevalence of RD was 3.3% in the NP group, 10.2% in the CP group, 5.3% in the NCP group, and 14.5% in the MP group (P < 0.001 by ANOVA tests). The adjusted odds ratio for RD was 3.38 (95% confidence interval, 1.27-9.04) for the MP group, compared with the NP group. The presence of RD showed an independent association with the MP counts (r = 0.155, P < 0.001); however, there was no association between RD and other plaque characteristics. In conclusion, RD is associated with MP rather than CP or NCP, compared with NP, which may reflect one of the developmental processes of CAD in patients with RD.

  18. Coronary artery atherectomy reduces plaque shear strains: an endovascular elastography imaging study.

    PubMed

    Keshavarz-Motamed, Zahra; Saijo, Yoshifumi; Majdouline, Younes; Riou, Laurent; Ohayon, Jacques; Cloutier, Guy

    2014-07-01

    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.

  19. Rupture, waves and earthquakes.

    PubMed

    Uenishi, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but "extraordinary" phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable.

  20. Rupture, waves and earthquakes

    NASA Astrophysics Data System (ADS)

    Uenishi, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but "extraordinary" phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable.

  1. Intravascular probe for detection of vulnerable plaque

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

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

  2. Characterizing atherosclerotic plaque with computed tomography: a contrast-detail study

    NASA Astrophysics Data System (ADS)

    Kasraie, Nima; Clarke, Geoffrey D.

    2012-02-01

    Plaque characterization may benefit from the increasing distinctiveness of the attenuating properties of different soft plaque components at lower energies. Due to the relative slight increase in the CT number of the nonadipose soft plaque at lower tube voltage settings vs. adipose plaque, a higher contrast between atheromous adipose and non-adipose plaque may become visible with modern 64 slice systems. A contrast-detail (C-D) phantom with varying plaque composition as the contrast generating method, was imaged on a commercial 64 slice MDCT system using 80, 120, and 140 kVp settings. The same phantom was also imaged on a Cone Beam CT (CBCT) system with a lower tube voltage of 75 kVp. The results of experiments from four different observers on three different plaque types (lipid, fiber, calcific) indicate that CT attenuation within lipid cores and fibrous masses vary not only with the percentage of lipid or fiber present, but also with the size of the cores. Furthermore, the C-D curve analysis for all three plaque types reveals that while the noise constraints prevent visible differentiation of soft plaque at current conventional 64 slice MDCT settings, CBCT exhibits superior visible contrast detectability than its conventional counterpart, with the latter having appreciably better resolution limits and beneficial lower tube voltages. This low voltage CT technique has the potential to be useful in composition based diagnosis of carotid vulnerable atherosclerotic plaque.

  3. Consistent detection of Felis domesticus papillomavirus 2 DNA sequences within feline viral plaques.

    PubMed

    Munday, John S; Peters-Kennedy, Jeanine

    2010-11-01

    Viral plaques are well recognized skin lesions of cats. They are thought to be caused by papillomavirus infection; however, the causative papillomavirus is uncertain. In the current study, polymerase chain reaction using 2 consensus primer sets and 1 primer set specific for Felis domesticus papillomavirus 2 (FdPV-2) was used to amplify DNA from a series of 14 feline viral plaques. The FdPV-2 sequences were detected in all 14 viral plaques by the specific primers but in only 1 of 14 feline cutaneous trichoblastomas. Papillomavirus DNA was amplified from 8 plaques using the consensus primers. Sequences from FdPV-2 were amplified using the consensus primers from 4 plaques. In addition, 3 plaques contained papillomavirus DNA sequences from Felis domesticus papillomavirus sequence MY1, and a previously unreported papillomavirus DNA sequence was amplified from 1 plaque. As FdPV-2 was consistently present within the plaques, this suggests that this papillomavirus is the likely etiologic agent. Feline viral plaques can undergo neoplastic transformation to Bowenoid in situ carcinomas (BISCs). As FdPV-2 DNA is frequently present within BISCs, this suggests that FdPV-2 induces viral plaque formation and then remains detectible after neoplastic transformation.

  4. Complete Achilles tendon ruptures.

    PubMed

    Landvater, S J; Renström, P A

    1992-10-01

    Achilles tendon ruptures can be treated nonsurgically in the nonathletic or low-end recreational athletic patient, particularly those more than 50 years of age, provided the treating physician does not delay in the diagnosis and treatment (preferably less than 48 hrs and possibly less than 1 week). The patient should be advised of the higher incidence of re-rupture of the tendon when treated nonsurgically. Surgical treatment is recommended for patients who are young and athletic. This is particularly true because the major criticism of surgical treatment has been the complication rate, which has decreased to a low level and to a mild degree, usually not significantly affecting the repair over time. Surgical treatment in these individuals seems to be superior not only in regard to re-rupture but also in assuring the correct apposition of the tendon ends and in placing the necessary tension on the tendon to secure appropriate orientation of the collagen fibers. This in turn allows them to regain full strength, power, endurance, and an early return to sports. Surgery is also recommended for late diagnosed ruptures where there is significant lengthening of the tendon. Surgical technique should involve a medial incision to avoid the sural nerve, absorbable suture, and augmentation with fascia or tendon where there is a gap or late rupture. Postoperatively, the immobilization should be 7 to 10 days in a splint. A walking boot with early motion in plantar flexion or a short leg cast with the tendon under slight tension should thereafter be used for 4 to 5 weeks. An early and well-supervised rehabilitation program should be initiated to restore the patient to the preinjury activity level.

  5. Rupture of the plantar fascia.

    PubMed

    Pai, V S

    1996-01-01

    Rupture of the plantar fascia in athletes engaged in sports that require running and jumping has been reported. However, spontaneous degenerative rupture of the plantar fascia is not well documented in the literature. This paper reports a patient with degenerative rupture of the plantar fascia.

  6. High expression of genes for calcification-regulating proteins in human atherosclerotic plaques.

    PubMed Central

    Shanahan, C M; Cary, N R; Metcalfe, J C; Weissberg, P L

    1994-01-01

    Calcification is common in atheromatous plaques and may contribute to plaque rupture and subsequent thrombosis. However, little is known about the mechanisms which regulate the calcification process. Using in situ hybridization and immunohistochemistry we show that two bone-associated proteins, osteopontin (OP) and matrix Gla protein (MGP), are highly expressed in human atheromatous plaques. High levels of OP mRNA and protein were found in association with necrotic lipid cores and areas of calcification. The predominant cell type in these areas was the macrophage-derived foam cell, although some smooth muscle cells could also be identified. MGP was expressed uniformly by smooth muscle cells in the normal media and at high levels in parts of the atheromatous intima. Highest levels of this matrix-associated protein were found in lipid-rich areas of the plaque. The pattern of expression of these two genes contrasted markedly with that of calponin and SM22 alpha, genes expressed predominantly by differentiated smooth muscle cells and whose expression was generally confined to the media of the vessel. The postulated function of OP and MGP as regulators of calcification in bone and the high levels and colocalization of both in atheromatous plaques suggest they have an important role in plaque pathogenesis and stability. Images PMID:8200973

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  9. Proteomic differences in amyloid plaques in rapidly progressive and sporadic Alzheimer's disease.

    PubMed

    Drummond, Eleanor; Nayak, Shruti; Faustin, Arline; Pires, Geoffrey; A Hickman, Richard; Askenazi, Manor; Cohen, Mark; Haldiman, Tracy; Kim, Chae; Han, Xiaoxia; Shao, Yongzhao; Safar, Jiri G; Ueberheide, Beatrix; Wisniewski, Thomas

    2017-03-04

    Rapidly progressive Alzheimer's disease (rpAD) is a particularly aggressive form of Alzheimer's disease, with a median survival time of 7-10 months after diagnosis. Why these patients have such a rapid progression of Alzheimer's disease is currently unknown. To further understand pathological differences between rpAD and typical sporadic Alzheimer's disease (sAD) we used localized proteomics to analyze the protein differences in amyloid plaques in rpAD and sAD. Label-free quantitative LC-MS/MS was performed on amyloid plaques microdissected from rpAD and sAD patients (n = 22 for each patient group) and protein expression differences were quantified. On average, 913 ± 30 (mean ± SEM) proteins were quantified in plaques from each patient and 279 of these proteins were consistently found in plaques from every patient. We found significant differences in protein composition between rpAD and sAD plaques. We found that rpAD plaques contained significantly higher levels of neuronal proteins (p = 0.0017) and significantly lower levels of astrocytic proteins (p = 1.08 × 10(-6)). Unexpectedly, cumulative protein differences in rpAD plaques did not suggest accelerated typical sAD. Plaques from patients with rpAD were particularly abundant in synaptic proteins, especially those involved in synaptic vesicle release, highlighting the potential importance of synaptic dysfunction in the accelerated development of plaque pathology in rpAD. Combined, our data provide new direct evidence that amyloid plaques do not all have the same protein composition and that the proteomic differences in plaques could provide important insight into the factors that contribute to plaque development. The cumulative protein differences in rpAD plaques suggest rpAD may be a novel subtype of Alzheimer's disease.

  10. Vulnerable atherosclerotic plaque elasticity reconstruction based on a segmentation-driven optimization procedure using strain measurements: theoretical framework.

    PubMed

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

    2009-07-01

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

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

    PubMed Central

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

    2016-01-01

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

  12. Optical detection of structural changes in human carotid atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Korol, R. M.; Canham, P. B.; Finlay, H. M.; Hammond, R. R.; Quantz, M.; Ferguson, G. G.; Liu, L. Y.; Lucas, A. R.

    2005-08-01

    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 μm. 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

  13. Anti‐Inflammatory Immune Skewing Is Atheroprotective: Apoe−/−FcγRIIb−/− Mice Develop Fibrous Carotid Plaques

    PubMed Central

    Harmon, Erin Y.; Fronhofer, Van; Keller, Rebecca S.; Feustel, Paul J.; Zhu, Xinmei; Xu, Hao; Avram, Dorina; Jones, David M.; Nagarajan, Shanmugam; Lennartz, Michelle R.

    2014-01-01

    Background Stroke, caused by carotid plaque rupture, is a major cause of death in the United States. Whereas vulnerable human plaques have higher Fc receptor (FcγR) expression than their stable counterparts, how FcγR expression impacts plaque histology is unknown. We investigated the role of FcγRIIb in carotid plaque development and stability in apolipoprotein (Apo)e−/− and Apoe−/−FcγRIIb−/− double knockout (DKO) animals. Methods and Results Plaques were induced by implantation of a shear stress‐modifying cast around the carotid artery. Plaque length and stenosis were followed longitudinally using ultrasound biomicroscopy. Immune status was determined by flow cytometry, cytokine release, immunoglobulin G concentration and analysis of macrophage polarization both in plaques and in vitro. Surprisingly, DKO animals had lower plaque burden in both carotid artery and descending aorta. Plaques from Apoe−/− mice were foam‐cell rich and resembled vulnerable human specimens, whereas those from DKO mice were fibrous and histologically stable. Plaques from DKO animals expressed higher arginase 1 (Arg‐1) and lower inducible nitric oxide synthase (iNOS), indicating the presence of M2 macrophages. Analysis of blood and cervical lymph nodes revealed higher interleukin (IL)‐10, immune complexes, and regulatory T cells (Tregs) and lower IL‐12, IL‐1β, and tumor necrosis factor alpha (TNF‐α) in DKO mice. Similarly, in vitro stimulation produced higher IL‐10 and Arg‐1 and lower iNOS, IL‐1β, and TNF‐α in DKO versus Apoe−/− macrophages. These results define a systemic anti‐inflammatory phenotype. Conclusions We hypothesized that removal of FcγRIIb would exacerbate atherosclerosis and generate unstable plaques. However, we found that deletion of FcγRIIb on a congenic C57BL/6 background induces an anti‐inflammatory Treg/M2 polarization that is atheroprotective. PMID:25516435

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

    NASA Astrophysics Data System (ADS)

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

    2006-03-01

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

  15. Machine learning techniques as a helpful tool toward determination of plaque vulnerability.

    PubMed

    Cilla, Myriam; Martínez, Javier; Peña, Estefanía; Martínez, Miguel Ángel

    2012-04-01

    Atherosclerotic cardiovascular disease results in millions of sudden deaths annually, and coronary artery disease accounts for the majority of this toll. Plaque rupture plays main role in the majority of acute coronary syndromes. Rupture has been usually associated with stress concentrations, which are determined mainly by tissue properties and plaque geometry. The aim of this study is develop a tool, using machine learning techniques to assist the clinical professionals on decisions of the vulnerability of the atheroma plaque. In practice, the main drawbacks of 3-D finite element analysis to predict the vulnerability risk are the huge main memories required and the long computation times. Therefore, it is essential to use these methods which are faster and more efficient. This paper discusses two potential applications of computational technologies, artificial neural networks and support vector machines, used to assess the role of maximum principal stress in a coronary vessel with atheroma plaque as a function of the main geometrical features in order to quantify the vulnerability risk.

  16. Morphodynamic interpretation of acute coronary thrombosis, with special reference to volcano-like eruption of atheromatous plaque caused by coronary artery spasm.

    PubMed

    Lin, C S; Penha, P D; Zak, F G; Lin, J C

    1988-06-01

    Routine autopsy studies of hearts with coronary thrombosis, collected over a period of eleven years, showed unique morphologic features of rupture of soft atheromatous plaques. These features include: (1) irregular luminar outline: angulation, invagination, upheaval, and/or wrinkles, (2) wavy outline of atheromatous cavity, (3) volcano-like rupture with seepage or gushing of semiliquid atheromatous contents into lumen, (4) cholesterol crystals arranged in rheologic vector direction, (5) rupture of deeper intimal fibrous tissue, (6) one or multiple intimal upheavals, (7) focal thickening of contracted media, (8) vestige of volcano-like eruption with organized thrombus, and (9) old thrombotic occlusion with wavy appearance of thick intimal fibrous tissue. The authors present a dynamic model of vasoconstriction or artery spasm that accounts for these features and the rupture of soft atheromatous plaques.

  17. Premature rupture of membranes.

    PubMed Central

    Poma, P. A.

    1996-01-01

    The management of patients with premature rupture of membranes has changed markedly in the past several years. The basis for this is a combination of a better understanding of newborn physiology, improved neonatal care, refinements in antibiotic therapy, and the widespread use of maternal and fetal monitoring. The best outcome for both mother and infant undoubtedly reflects data based on a combination of factors, among which are gestational age survival, evidence of fetal distress, presence or absence of labor and sepsis, and of course, the cervical condition as it is related to labor-readiness. An important recent advance is the recognition that an active observation management program is associated with less morbidity and mortality than the classic management course of delivery within 12 hours of membrane rupture. The fact that preterm premature rupture of membranes tends to recur in subsequent pregnancies offers an opportunity for prevention. Moreover, advances in perinatal and neonatal care will continue to improve the outcomes of these women and their children. PMID:8583489

  18. Effect of atherosclerosis on thermo-mechanical properties of arterial wall and its repercussion on plaque instability.

    PubMed

    Guinea, G V; Atienza, J M; Fantidis, P; Rojo, F J; Ortega, A; Torres, M; Gonzalez, P; Elices, M L; Hayashi, K; Elices, M

    2009-03-06

    Data from the literature report febrile reactions prior to myocardial infarction in patients with normal coronary arteries and that coronary syndromes seem to be triggered by bacterial and viral infections, being fever the common symptom. The thermo-mechanical behavior of thoracic aortas of New Zealand White rabbits with different degrees of atherosclerosis was measured by means of pressure-diameter tests at different temperatures. Specific measurements of the thermal dilatation coefficient of atheroma plaques were performed by means of tensile tests. Results show a different thermo-mechanical behavior, the dilatation coefficient of atheroma plaque being at least twice that of the arterial wall. Temperature-induced mechanical stress at the plaque-vessel interface could be enough to promote plaque rupture. Therefore, increases of corporal temperature, either local or systemic, can play a role in increasing the risk of acute coronary syndromes and deserve a more comprehensive study.

  19. Modeling rupture segmentations on the Cascadia megathrust

    NASA Astrophysics Data System (ADS)

    Yang, H.; Liu, Y.; McGuire, J. J.

    2012-12-01

    The Cascadia subduction zone has produced a series of large to great earthquakes, most recently in 1700 AD. Paleoseismological studies of submarine turbidites suggest a significant difference in recurrence interval between Northern (~500 year) and Southern (~200-300 year) Cascadia. Whether future large ruptures are segmented is very important for estimating hazard in Pacific Northwest, but remains enigmatic from the interpretations of current locking maps. Our approach is to develop rupture scenarios of Cascadia earthquakes by performing numerical simulations using the finite element software, PyLith. Based on the USGS plate interface model of Cascadia, we have constructed a realistic three-dimensional subduction fault model that stretches from Northern California to Central Vancouver Island. We have performed a number of dynamic rupture simulations using a set of artificial friction parameters and uniform stress distributions on the fault governed by a slip-weakening friction law. Preliminary results show that ruptures have initiated from the nucleation zone with higher shear stress than the ambient fault and have propagated on the realistic three-dimensional fault surface. The increase of dip angle with depth has little effect on the rupture propagation because that is governed mostly by the fault strength. The along-strike bend of the fault beneath Washington state and Vancouver Island has not impeded the rupture propagation given the uniform fault strength. To estimate the possible rupture segmentation, we have converted a slip-deficit rate model derived from GPS data into stress change distributions on the fault assuming the entire slip deficit would be released in the next great earthquake. We are also constructing another initial stress map derived from tidal and leveling data, which shows a significant difference in the locking depth beneath Central Oregon. The other important variable, the spatial variation of frictional parameters, however, has to be

  20. Concept of Remission in Chronic Plaque Psoriasis.

    PubMed

    Gisondi, Paolo; Di Mercurio, Marco; Idolazzi, Luca; Girolomoni, Giampiero

    2015-11-01

    Psoriasis is a lifelong chronic inflammatory disease affecting 2-3% of the worldwide population. Current understanding of the pathogenesis of psoriasis assigns central importance to an interaction between acquired and innate immunity. The disease is characterized by a series of linked cellular changes in the skin, including hyperplasia of epidermal keratinocytes, angiogenesis, and infiltration of T lymphocytes, neutrophils, and other types of leukocytes in the affected skin. Plaque psoriasis is the most common clinical form and is characterized by red and scaly plaques generally localized at extensor sites such as elbows and knees. Major determinants of psoriasis severity include the extent of skin involvement; localization in highly affected areas such as scalp, palms, and soles; pruritus; presence of comorbidities including psoriatic arthritis; and impairment on quality of life. About one-third of patients have moderate to severe psoriasis defined as PASI (Psoriasis Area and Severity Index) and/or Dermatology Life Quality Index>10, and/or affected body surface area>10%. The optimal treatment goal is to safely achieve complete or almost complete skin clearance. Treatments available are various and they are chosen according to disease features, comorbidities, and patient characteristics and priorities. Topical treatments including corticosteroids and Vitamin D analogs are reserved for mild disease. Phototherapy, cyclosporine, methotrexate, acitretin, or biologics such as tumor necrosis factor-α antagonists and ustekinumab are reserved for the moderate to severe forms.

  1. [Premonitory sign of myocardial rupture].

    PubMed

    Lauten, A; Dittrich, P

    1975-10-01

    It is reported on 14 cases in which a rupture of the myocardium occurred following a myocardial infarction. The moment of the appearance as well as anamnestic and clinical peculiarities are examined. As the only usable symptom of the rupture the symptomatology of the electromechanic dissociation must be taken into consideration. Finally it is referred to the on principle possible operative consequences of the rupture of the myocardium (oversewing or infarctetomy).

  2. Semi-Automated Curation Allows Causal Network Model Building for the Quantification of Age-Dependent Plaque Progression in ApoE−/− Mouse

    PubMed Central

    Szostak, Justyna; Martin, Florian; Talikka, Marja; Peitsch, Manuel C.; Hoeng, Julia

    2016-01-01

    The cellular and molecular mechanisms behind the process of atherosclerotic plaque destabilization are complex, and molecular data from aortic plaques are difficult to interpret. Biological network models may overcome these difficulties and precisely quantify the molecular mechanisms impacted during disease progression. The atherosclerosis plaque destabilization biological network model was constructed with the semiautomated curation pipeline, BELIEF. Cellular and molecular mechanisms promoting plaque destabilization or rupture were captured in the network model. Public transcriptomic data sets were used to demonstrate the specificity of the network model and to capture the different mechanisms that were impacted in ApoE−/− mouse aorta at 6 and 32 weeks. We concluded that network models combined with the network perturbation amplitude algorithm provide a sensitive, quantitative method to follow disease progression at the molecular level. This approach can be used to investigate and quantify molecular mechanisms during plaque progression. PMID:27840576

  3. Semi-Automated Curation Allows Causal Network Model Building for the Quantification of Age-Dependent Plaque Progression in ApoE(-/-) Mouse.

    PubMed

    Szostak, Justyna; Martin, Florian; Talikka, Marja; Peitsch, Manuel C; Hoeng, Julia

    2016-01-01

    The cellular and molecular mechanisms behind the process of atherosclerotic plaque destabilization are complex, and molecular data from aortic plaques are difficult to interpret. Biological network models may overcome these difficulties and precisely quantify the molecular mechanisms impacted during disease progression. The atherosclerosis plaque destabilization biological network model was constructed with the semiautomated curation pipeline, BELIEF. Cellular and molecular mechanisms promoting plaque destabilization or rupture were captured in the network model. Public transcriptomic data sets were used to demonstrate the specificity of the network model and to capture the different mechanisms that were impacted in ApoE(-/-) mouse aorta at 6 and 32 weeks. We concluded that network models combined with the network perturbation amplitude algorithm provide a sensitive, quantitative method to follow disease progression at the molecular level. This approach can be used to investigate and quantify molecular mechanisms during plaque progression.

  4. Slow rupture of polymer films

    NASA Astrophysics Data System (ADS)

    Kliakhandler, Igor

    2004-11-01

    Bursting of soap film is a fast and fascinating process. It turns out that certain polymer films rupture in a somewhat similar fashion, but much slower. The slowness of the process allows one to study the rupture of polymer films with details. The rupture process in Hele-Shaw-like fashion shows remarkable properties, and is a very simple system. It turns out that propagation speed of the rupture is a function of the film thickness, and rheologic properties of the polymer. Experimental results will be compared with theory, together with demonstration of the experiment.

  5. Rupture of an ascending aortic aneurysm as a cause of sudden death

    PubMed Central

    de Freitas, Cristielle Peres; Petrini, Carla Andrade; Araújo, Ramon Souza Goes; Lima, Luiz Guilherme Cernaglia Aureliano; Picciarelli de Lima, Patrícia

    2016-01-01

    An 84-year-old female patient was brought to the emergency department in cardiac arrest. Cardiopulmonary resuscitation maneuvers were performed but were unsuccessful. The patient had a past medical history of systemic arterial hypertension with target-organ lesions, including stroke and myocardial infarction. The autopsy was carried out, and the most striking finding was cardiac tamponade due to the rupture of an ascending aortic aneurysm at the site of a complex atheromatous plaque. Rupture is the most serious complication of a thoracic aneurysm and must be considered in the differential diagnosis of sudden death. PMID:27818955

  6. Intravascular detection of microvessel infiltration in atherosclerotic plaques: An intraluminal extension of acoustic angiography

    NASA Astrophysics Data System (ADS)

    Martin, K. Heath

    Cardiovascular disease is the leading cause of death worldwide, surpassing both stroke and cancer related mortality with 17.5 million deaths in 2014 alone. Atherosclerosis is the build-up of fatty deposits within arteries and is responsible for the majority of cardiovascular related deaths. Over the past decade, research in atherosclerosis has identified that a key limitation in the appropriate management of the disease is detecting and identifying dangerous fatty plaque build-ups before they dislodge and cause major cardiovascular events, such as embolisms, stroke, or myocardial infarctions. It has been noted that plaques vulnerable to rupture have several key features that may be used to distinguish them from asymptomatic plaques. One key identifier of a dangerous plaque is the presence of blood flow within the plaque itself since this is an indicator of growth and instability of the plaque. Recently, a superharmonic imaging method known as "acoustic angiography" has been shown to resolve microvasculature with unprecedented quality and could be a possible method of detecting blood vessel infiltration within these plaques. This dissertation describes the material and methods used to move the application of "acoustic angiography" to a reduced form factor typical of intravascular catheters and to demonstrate its ability to detect microvasculature. The implementation of this approach is described in terms of the contrast agents used to generate superharmonic signals, the dual-frequency transducers to image them, and the hardware needed to operate them in order to establish how these design choices can impact the quality of the images produced. Furthermore, this dissertation demonstrates how image processing methods such as adaptive windowing or automated sound speed correction can further enhance image quality of vascular targets. The results of these chapters show how acoustic angiography may be optimized using engineering considerations both in signal acquisition

  7. Wrapped Wire Detects Rupture Of Pressure Vessel

    NASA Technical Reports Server (NTRS)

    Hunt, James B.

    1990-01-01

    Simple, inexpensive technique helps protect against damage caused by continuing operation of equipment after rupture or burnout of pressure vessel. Wire wrapped over area on outside of vessel where breakthrough most likely. If wall breaks or burns, so does wire. Current passing through wire ceases, triggering cutoff mechanism stopping flow in vessel to prevent further damage. Applied in other situations in which pipes or vessels fail due to overpressure, overheating, or corrosion.

  8. Ultrasonic Transducer-Guided Electrochemical Impedance Spectroscopy to Assess Lipid-Laden Plaques.

    PubMed

    Ma, Jianguo; Luo, Yuan; Sevag Packard, René R; Ma, Teng; Ding, Yichen; Abiri, Parinaz; Tai, Yu-Chong; Zhou, Qifa; Shung, Kirk K; Li, Rongsong; Hsiai, Tzung

    2016-11-01

    Plaque rupture causes acute coronary syndromes and stroke. Intraplaque oxidized low density lipoprotein (oxLDL) is metabolically unstable and prone to induce rupture. We designed an intravascular ultrasound (IVUS)-guided electrochemical impedance spectroscopy (EIS) sensor to enhance the detection reproducibility of oxLDL-laden plaques. The flexible 2-point micro-electrode array for EIS was affixed to an inflatable balloon anchored onto a co-axial double layer catheter (outer diameter = 2 mm). The mechanically scanning-driven IVUS transducer (45 MHz) was deployed through the inner catheter (diameter = 1.3 mm) to the acoustic impedance matched-imaging window. Water filled the inner catheter to match acoustic impedance and air was pumped between the inner and outer catheters to inflate the balloon. The integrated EIS and IVUS sensor was deployed into the ex vivo aortas dissected from the fat-fed New Zealand White (NZW) rabbits (n=3 for fat-fed, n= 5 normal diet). IVUS imaging was able to guide the 2-point electrode to align with the plaque for EIS measurement upon balloon inflation. IVUS-guided EIS signal demonstrated reduced variability and increased reproducibility (p < 0.0001 for magnitude, p < 0.05 for phase at < 15 kHz) as compared to EIS sensor alone (p < 0.07 for impedance, p < 0.4 for phase at < 15 kHz). Thus, we enhanced topographic and EIS detection of oxLDL-laden plaques via a catheter-based integrated sensor design to enhance clinical assessment for unstable plaque.

  9. [Is regression of atherosclerotic plaque possible?

    PubMed

    Páramo, José A; Civeira, Fernando

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

  10. Spontaneous rupture on irregular faults

    NASA Astrophysics Data System (ADS)

    Liu, C.

    2014-12-01

    It is now know (e.g. Robinson et al., 2006) that when ruptures propagate around bends, the rupture velocity decrease. In the extreme case, a large bend in the fault can stop the rupture. We develop a 2-D finite difference method to simulate spontaneous dynamic rupture on irregular faults. This method is based on a second order leap-frog finite difference scheme on a uniform mesh of triangles. A relaxation method is used to generate an irregular fault geometry-conforming mesh from the uniform mesh. Through this numerical coordinate mapping, the elastic wave equations are transformed and solved in a curvilinear coordinate system. Extensive numerical experiments using the linear slip-weakening law will be shown to demonstrate the effect of fault geometry on rupture properties. A long term goal is to simulate the strong ground motion near the vicinity of bends, jogs, etc.

  11. 3D carotid plaque MR Imaging

    PubMed Central

    Parker, Dennis L.

    2015-01-01

    SYNOPSIS There has been significant progress made in 3D carotid plaque magnetic resonance imaging techniques in recent years. 3D plaque imaging clearly represents the future in clinical use. With effective flow suppression techniques, choices of different contrast weighting acquisitions, and time-efficient imaging approaches, 3D plaque imaging offers flexible imaging plane and view angle analysis, large coverage, multi-vascular beds capability, and even can be used in fast screening. PMID:26610656

  12. Towards coronary plaque imaging using simultaneous PET-MR: a simulation study

    NASA Astrophysics Data System (ADS)

    Petibon, Y.; El Fakhri, G.; Nezafat, R.; Johnson, N.; Brady, T.; Ouyang, J.

    2014-03-01

    Coronary atherosclerotic plaque rupture is the main cause of myocardial infarction and the leading killer in the US. Inflammation is a known bio-marker of plaque vulnerability and can be assessed non-invasively using fluorodeoxyglucose-positron emission tomography imaging (FDG-PET). However, cardiac and respiratory motion of the heart makes PET detection of coronary plaque very challenging. Fat surrounding coronary arteries allows the use of MRI to track plaque motion during simultaneous PET-MR examination. In this study, we proposed and assessed the performance of a fat-MR based coronary motion correction technique for improved FDG-PET coronary plaque imaging in simultaneous PET-MR. The proposed methods were evaluated in a realistic four-dimensional PET-MR simulation study obtained by combining patient water-fat separated MRI and XCAT anthropomorphic phantom. Five small lesions were digitally inserted inside the patients coronary vessels to mimic coronary atherosclerotic plaques. The heart of the XCAT phantom was digitally replaced with the patient's heart. Motion-dependent activity distributions, attenuation maps, and fat-MR volumes of the heart, were generated using the XCAT cardiac and respiratory motion fields. A full Monte Carlo simulation using Siemens mMR's geometry was performed for each motion phase. Cardiac/respiratory motion fields were estimated using non-rigid registration of the transformed fat-MR volumes and incorporated directly into the system matrix of PET reconstruction along with motion-dependent attenuation maps. The proposed motion correction method was compared to conventional PET reconstruction techniques such as no motion correction, cardiac gating, and dual cardiac-respiratory gating. Compared to uncorrected reconstructions, fat-MR based motion compensation yielded an average improvement of plaque-to-background contrast of 29.6%, 43.7%, 57.2%, and 70.6% for true plaque-to-blood ratios of 10, 15, 20 and 25:1, respectively. Channelized

  13. Spontaneous Rupture of Pyometra

    PubMed Central

    Mallah, Fatemeh; Eftekhar, Tahere; Naghavi-Behzad, Mohammad

    2013-01-01

    Spontaneous perforation is a very rare complication of pyometra. The clinical findings of perforated pyometra are similar to perforation of the gastrointestinal tract and other causes of acute abdomen. In most cases, a correct and definite diagnosis can be made only by laparotomy. We report two cases of diffuse peritonitis caused by spontaneous perforated pyometra. The first case is a 78-year-old woman with abdominal pain for which laparotomy was performed because of suspected incarcerated hernia. The second case is a 61-year-old woman with abdominal pain for which laparotomy was performed because of symptoms of peritonitis. At laparotomy of both cases, 1 liter of pus with the source of uterine was found in the abdominal cavity. The ruptured uterine is also detected. More investigations revealed no malignancy as the reason of the pyometra. PMID:24024054

  14. Carotid Plaque Characterization, Stenosis, and Intima-Media Thickness According to Age and Gender in a Large Registry Cohort

    PubMed Central

    Boulos, Nancy M.; Gardin, Julius M.; Malik, Shaista; Postley, John; Wong, Nathan D.

    2017-01-01

    Carotid intima-media thickness (CIMT) is a well-established predictor of cardiovascular disease events. Not well described, however, is the prevalence of plaque and stenosis severity and how this varies according to extent of CIMT, age, and gender. We evaluated the extent of carotid plaque and stenosis severity according to CIMT, age, and gender in a large CIMT screening registry. We studied 9,347 women and 12,676 men (n = 22,023) who received carotid ultrasound scans. The presence and severity of both carotid plaque and stenosis was compared according to extent of CIMT (≥1 mm vs <1 mm), age, and gender using the chi-square test of proportions. Among those aged <45 to ≥80 years, the prevalence of CIMT ≥1 mm ranged from 0.13% to 29.3% in women and 0.6% to 40.1% in men, stenosis ≥50% from 0.1% to 14.9% in women and 0.1% to 13.2% in men, and mixed and/or soft plaque from 7.1% to 66.5% in women, and 9.2% to 65.8% in men (all p <0.001 across age groups). Even when CIMT levels were <1 mm, >30% of patients demonstrated mixed or soft plaque potentially prone to rupture. Of those with CIMT ≥1 mm, more than 70% had such mixed or soft plaque and more than 40% demonstrated stenoses of 30% or greater. In conclusion, we describe in a large CIMT registry study a substantial age-related increase in both men and women of increased CIMT, plaque presence, and severity, and stenosis. Even in those with normal CIMT, mixed or soft plaque was common, further demonstrating the value in assessing for plaque when doing carotid ultrasound. PMID:26869392

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

    NASA Astrophysics Data System (ADS)

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

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

  16. Spontaneous splenic rupture in an acute leukemia patient with splenic tuberculosis: A case report

    PubMed Central

    Zhang, Yue; Zhang, Juan; Chen, Tingting; Zeng, Hui; Zhao, Bing; Zhang, Yong; Zhou, Xiaohuan; Han, Wei; Hu, Yanping; Liu, Fengge; Shan, Zhijuan; Gao, Weifeng; Zhou, Hebing

    2017-01-01

    Spontaneous splenic rupture, also referred to as atraumatic splenic rupture, is a rare but life-threatening emergency condition. Without timely diagnosis and treatment, the mortality rate of splenic rupture approaches 100%. The etiology of atraumatic splenic rupture varies; it is reportedly associated with neoplasms or splenic infection, but is rarely encountered in patients with both conditions. We herein report the case of a 58-year-old male patient with acute myeloid leukemia (AML) complicated by splenic tuberculosis (TB), who presented with spontaneous rupture of the spleen. Pathological examination of the resected spleen revealed multifocal granulomatosis with caseous necrosis. However, with timely diagnosis and surgical intervention, the patient recovered successfully and is currently on consolidation therapy. To the best of our knowledge, this is the first case of spontaneous splenic rupture in AML with splenic TB. The relevant literature on spontaneous splenic rupture was also reviewed and the potential etiology and treatment were discussed. PMID:28357096

  17. Plaquing procedure for infectious hematopoietic necrosis virus

    USGS Publications Warehouse

    Burke, J.A.; Mulcahy, D.

    1980-01-01

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

  18. Fault branching and rupture directivity

    NASA Astrophysics Data System (ADS)

    Fliss, Sonia; Bhat, Harsha S.; Dmowska, Renata; Rice, James R.

    2005-06-01

    Could the directivity of a complex earthquake be inferred from the ruptured fault branches it created? Typically, branches develop in forward orientation, making acute angles relative to the propagation direction. Direct backward branching of the same style as the main rupture (e.g., both right lateral) is disallowed by the stress field at the rupture front. Here we propose another mechanism of backward branching. In that mechanism, rupture stops along one fault strand, radiates stress to a neighboring strand, nucleates there, and develops bilaterally, generating a backward branch. Such makes diagnosing directivity of a past earthquake difficult without detailed knowledge of the branching process. As a field example, in the Landers 1992 earthquake, rupture stopped at the northern end of the Kickapoo fault, jumped onto the Homestead Valley fault, and developed bilaterally there, NNW to continue the main rupture but also SSE for 4 km forming a backward branch. We develop theoretical principles underlying such rupture transitions, partly from elastostatic stress analysis, and then simulate the Landers example numerically using a two-dimensional elastodynamic boundary integral equation formulation incorporating slip-weakening rupture. This reproduces the proposed backward branching mechanism based on realistic if simplified fault geometries, prestress orientation corresponding to the region, standard lab friction values for peak strength, and fracture energies characteristic of the Landers event. We also show that the seismic S ratio controls the jumpable distance and that curving of a fault toward its compressional side, like locally along the southeastern Homestead Valley fault, induces near-tip increase of compressive normal stress that slows rupture propagation.

  19. Plaque and arterial vulnerability investigation in a three-layer atherosclerotic human coronary artery using computational fluid-structure interaction method

    NASA Astrophysics Data System (ADS)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

    2014-08-01

    Coronary artery disease is the common form of cardiovascular diseases and known to be the main reason of deaths in the world. Fluid-Structure Interaction (FSI) simulations can be employed to assess the interactions of artery/plaque and blood to provide a more precise anticipation for rupture of arterial tissue layers and plaque tissues inside an atherosclerotic artery. To date, the arterial tissue in computational FSI simulations has been considered as a one-layer structure. However, a single layer assumption might have deeply bounded the results and, consequently, more computational simulation is needed by considering the arterial tissue as a three-layer structure. In this study, a three-dimensional computational FSI model of an atherosclerotic artery with a three-layer structure and different plaque types was established to perform a more accurate arterial wall/plaque tissue vulnerability assessment. The hyperelastic material coefficients of arterial layers were calculated and implemented in the computational model. The fully coupled fluid and structure models were solved using the explicit dynamics finite element code LS-DYNA. The results revealed the significant role of plaque types in the normal and shear stresses induced within the arterial tissue layers. The highest von Mises and shear stresses were observed on the stiffest calcified plaque with 3.59 and 3.27 MPa, while the lowest von Mises and shear stresses were seen on the hypocellular plaque with 1.15 and 0.63 MPa, respectively. Regardless of plaque types, the media and adventitia layers were played protective roles by displaying less stress on their wall, whilst the intima layer was at a high risk of rupture. The findings of this study have implications not only for determining the most vulnerable arterial layer/plaque tissue inside an atherosclerotic coronary artery but also for balloon-angioplasty, stenting, and bypass surgeries.

  20. Spectroscopic photoacoustic imaging of lipid-rich plaques in the human aorta in the 740 to 1400 nm wavelength range

    NASA Astrophysics Data System (ADS)

    Allen, Thomas J.; Hall, Andrew; Dhillon, Amar P.; Owen, James S.; Beard, Paul C.

    2012-06-01

    Spectroscopic photoacoustic imaging has the potential to discriminate between normal and lipid-rich atheromatous areas of arterial tissue by exploiting the differences in the absorption spectra of lipids and normal arterial tissue in the 740 to 1400 nm wavelength range. Identification of regions of high lipid concentration would be useful to identify plaques that are likely to rupture (vulnerable plaques). To demonstrate the feasibility of visualizing lipid-rich plaques, samples of human aortas were imaged in forward mode, at wavelengths of 970 and 1210 nm. It was shown that the structure of the arterial wall and the boundaries of lipid-rich plaques obtained from the photoacoustic images were in good agreement with histology. The presence of lipids was also confirmed by comparing the photoacoustic spectra (740 to 1400 nm) obtained in a region within the plaque to the spectral signature of lipids. Furthermore, a lipid-rich plaque was successfully imaged while illuminating the sample through 2.8 mm of blood demonstrating the possibility of implementing the photoacoustic technique in vivo.

  1. Rheumatoid flexor tenosynovitis and rupture.

    PubMed

    Ferlic, D C

    1996-08-01

    Rheumatoid flexor tenosynovitis at the wrist can cause locking, limitation of motion, nerve compression, and rupture of tendons. To prevent and treat these conditions, a flexor tenosynovectomy, combined with nerve decompression and tendon reconstruction as indicated, is necessary. If tendons are ruptured, the flexor pollicis longus and profundus to the index finger are most commonly affected. On the fingers flexor tenosynovitis can also cause locking, decrease in range of motion and rupture tendons. Flexor tenosynovitis of the fingers should be treated with decompression of the tendons health with preservation of the pulley system.

  2. Intracranial dermoid cyst rupture-related brain ischemia

    PubMed Central

    Jin, Hang; Guo, Zhen-Ni; Luo, Yun; Zhao, Ren; Sun, Ming-Shuo; Yang, Yi

    2017-01-01

    Abstract Rationale: Spontaneous rupture of intracranial dermoid cyst is a rare but serious clinical event that can result in cerebral ischemia. Cerebral vasospasm and vasculitis are considered as potential mechanisms of dermoid cyst rupture-related cerebral ischemia. However, the hemodynamic mechanisms between cerebral ischemia and dermoid cyst rupture are not well known. Patient concerns: A 55-year-old, right-handed man was admitted to our hospital with sudden receptive aphasia and right-sided hypoalgesia. Brain magnetic resonance imaging (MRI) revealed a ruptured dermoid cyst and watershed infarcts in the left hemisphere. Then brain magnetic resonance angiography disclosed mild stenosis in the left middle cerebral artery (MCA), and further high-resolution MRI demonstrated it was caused by an unstable atherosclerosis plaque. Transcranial Doppler of the patient showed a decreasing tendency of peak systolic velocity (PSV) of the left MCA at different time points after the stroke (from 290cm/s at day 6 to 120cm/s at day 30), indicating a transient vasospasm. However, the time course of dynamic cerebral autoregulation (dCA) seemed different from the PSV. The patient's dCA reached its lowest point at day 8 and was restored at day 10. The time course of dCA indicated a “called procedure” of a cerebrovascular regulating function to deal with the stimulation in subarachnoid space. Diagnoses: A dermoid cyst rupture-related cerebral infarction was diagnosed in this patient. Interventions: Aspirin (100 mg/d) and atorvastatin (20 mg/d) were given to the patient. A neurosurgical operation was strongly recommended to minimize the risk of further injury of the ruptured dermoid cyst; however, the patient refused the recommended treatment. Outcomes: The neurological deficit of the patient was significantly improved on 30 days follow-up. Lessons: We found that the spread of cyst contents through the subarachnoid and/or ventricular system can induce a vasospasm. Then, dCA was

  3. Elbow tendinopathy and tendon ruptures: epicondylitis, biceps and triceps ruptures.

    PubMed

    Rineer, Craig A; Ruch, David S

    2009-03-01

    Lateral and medial epicondylitis are common causes of elbow pain in the general population, with the lateral variety being more common than the medial by a ratio reportedly ranging from 4:1 to 7:1. Initially thought to be an inflammatory condition, epicondylitis has ultimately been shown to result from tendinous microtearing followed by an incomplete reparative response. Numerous nonoperative and operative treatment options have been employed in the treatment of epicondylitis, without the emergence of a single, consistent, universally accepted treatment protocol. Tendon ruptures about the elbow are much less frequent, but result in more significant disability and loss of function. Distal biceps tendon ruptures typically occur in middle-aged males as a result of an event that causes a sudden, eccentric contraction of the biceps. Triceps tendon ruptures are exceedingly rare but usually have a similar etiology with a forceful eccentric contraction of the triceps that causes avulsion of the tendon from the olecranon. The diagnosis of these injuries is not always readily made. Complete ruptures of the biceps or triceps tendons have traditionally been treated surgically with good results. With regard to biceps ruptures, there continues to be debate about the best surgical approach, as well as the best method of fixation of tendon to bone. This article is not meant to be an exhaustive review of the broad topics of elbow tendinopathy and tendon ruptures, but rather is a review of recently published information on the topics that will assist the clinician in diagnosis and management of these conditions.

  4. Ruptured thought: rupture as a critical attitude to nursing research.

    PubMed

    Beedholm, Kirsten; Lomborg, Kirsten; Frederiksen, Kirsten

    2014-04-01

    In this paper, we introduce the notion of ‘rupture’ from the French philosopher Michel Foucault, whose studies of discourse and governmentality have become prominent within nursing research during the last 25 years. We argue that a rupture perspective can be helpful for identifying and maintaining a critical potential within nursing research. The paper begins by introducing rupture as an inheritance from the French epistemological tradition. It then describes how rupture appears in Foucault's works, as both an overall philosophical approach and as an analytic tool in his historical studies. Two examples of analytical applications of rupture are elaborated. In the first example, rupture has inspired us to make an effort to seek alternatives to mainstream conceptions of the phenomenon under study. In the second example, inspired by Foucault's work on discontinuity, we construct a framework for historical epochs in nursing history. The paper concludes by discussing the potential of the notion of rupture as a response to the methodological concerns regarding the use of Foucault-inspired discourse analysis within nursing research. We agree with the critique of Cheek that the critical potential of discourse analysis is at risk of being undermined by research that tends to convert the approach into a fixed method.

  5. Evaluation of plaques and stenosis.

    PubMed

    Arnoldi, Elisabeth; Henzler, Thomas; Bastarrika, Gorka; Thilo, Christian; Nikolaou, Konstantin; Schoepf, U Joseph

    2010-07-01

    Cardiac CT scan has emerged from a research tool to a widely used clinical modality in the diagnostic management of coronary artery disease. Based on evidence of numerous clinical studies coronary CT angiography (cCTA) has emerged as a fast, accurate, and noninvasive alternative to conventional angiography in selected patient populations. A major strength of cCTA is its ability to combine information on the coronary artery anatomy, the vessel lumen, and atherosclerotic lesions. Recent investigations on the application of cCTA in myocardial perfusion imaging suggest that cCTA may allow analysis of the hemodynamic relevance of detected stenosis. Data is accumulating that supports its relevance for patient management and outcome. This article examines the role of cCTA for the evaluation of plaques and stenosis.

  6. Plaque-based competitive hybridization.

    PubMed

    Villányi, Zoltán; Gyurján, István; Stéger, Viktor; Orosz, László

    2008-01-01

    The authors have developed a simple, cost-saving experimental design, plaque-based competitive hybridization (PBCH), for genome-wide identification of genes differentially expressed in different tissues. PBCH offers advantages in comparison with other methods used in comparative genomics by combining the principles of differential hybridization with the subtractive hybridization. PBCH is particularly advantageous when libraries with few differences are to be analyzed. The authors demonstrate the use of PBCH by identifying 3 genes, up-regulated in the developing velvet antler of red deer (Cervus elaphus): ApoD, C011A2, and S100a1. The fidelity and sensitivity of PBCH is also shown: 1 specific clone among a library sample of 15,000 can be recognized. Possibilities for further utilizations are discussed.

  7. Corneal plaque containing levofloxacin in a dog.

    PubMed

    Park, Young-Woo; Kang, Byung-Jae; Lim, Jae Hyun; Ahn, Jung-Mo; Lim, Hyun Sook

    2015-11-01

    A 13-year-old castrated male Yorkshire terrier developed a corneal ulcer 2 weeks after intracapsular lens extraction (ICLE) in the right eye. The corneal ulcer was treated with levofloxacin eye drops. A plaque with a white luster developed in the central cornea 2 weeks after treatment with levofloxacin eye drops. The corneal plaque was surgically removed under inhalant anesthesia. The corneal plaque displayed antimicrobial activity against Escherichia coli. Furthermore, levofloxacin content in the plaque was confirmed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry (MS). The corneal ulcer completely resolved 2 weeks after the surgical removal of the corneal lesion and replacement of levofloxacin eye drops with tobramycin eye drops. Although the topical use of levofloxacin is unlikely to lead to corneal chemical deposits due to the high water solubility of the drug compared to other topical fluoroquinolones, this patient developed corneal plaque of the antibiotic drop.

  8. Stabilization of high-risk plaques

    PubMed Central

    Takata, Kohei; Zhang, Bo; Miura, Shin-ichiro; Saku, Keijiro

    2016-01-01

    The prevalence of atherosclerotic cardiovascular diseases (ASCVDs) is increasing globally and they have become the leading cause of death in most countries. Numerous experimental and clinical studies have been conducted to identify major risk factors and effective control strategies for ASCVDs. The development of imaging modalities with the ability to determine the plaque composition enables us to further identify high-risk plaque and evaluate the effectiveness of different treatment strategies. While intensive lipid-lowering by statins can stabilize or even regress plaque by various mechanisms, such as the reduction of lipid accumulation in a necrotic lipid core, the reduction of inflammation, and improvement of endothelial function, there are still considerable residual risks that need to be understood. We reviewed important findings regarding plaque vulnerability and some encouraging emerging approaches for plaque stabilization. PMID:27500090

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

    PubMed

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

    2016-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  11. Relation of microchannel structure identified by optical coherence tomography to plaque vulnerability in patients with coronary artery disease.

    PubMed

    Kitabata, Hironori; Tanaka, Atsushi; Kubo, Takashi; Takarada, Shigeho; Kashiwagi, Manabu; Tsujioka, Hiroto; Ikejima, Hideyuki; Kuroi, Akio; Kataiwa, Hideaki; Ishibashi, Kohei; Komukai, Kenichi; Tanimoto, Takashi; Ino, Yasushi; Hirata, Kumiko; Nakamura, Nobuo; Mizukoshi, Masato; Imanishi, Toshio; Akasaka, Takashi

    2010-06-15

    Increased neovascularization in atherosclerotic plaques is associated with plaque vulnerability. The high resolution of optical coherence tomography (OCT) might provide a chance to directly visualize plaque neovascularization in vivo. The aim of the present study was to investigate the relation between microchannels in culprit plaques identified by OCT and plaque vulnerability in patients with coronary artery disease. A total of 63 consecutive patients with coronary artery disease who had undergone both OCT and intravascular ultrasound before any interventions to examine culprit lesion morphologies were enrolled. Microchannel was defined as a no-signal tubuloluminal structure on the cross-sectional optical coherence tomographic image. Microchannels were found in 24 (38%) of the 63 patients. The patients were divided into 2 groups according to the presence or absence of microchannels. The frequency of plaque rupture tended to be greater in the microchannel group (50% vs 28%, p = 0.11). The thickness of the fibrous cap (median 60 vs 100 microm, p = 0.001) was significantly less in the patients with microchannels, and significant differences were found in the frequency of thin-cap fibroatheroma (54% vs 21%, p = 0.012) and positive remodeling (67% vs 36%, p = 0.02) between the 2 groups. The high-sensitivity C-reactive protein levels in the microchannel group was significantly greater than those in the no-microchannel group (median 0.27 vs 0.13 mg/dl, p = 0.015). Moreover, increased microchannel counts were associated with greater high-sensitivity C-reactive protein levels (p = 0.01). In conclusion, a significant relation was found between the presence of microchannels in plaques identified by OCT and plaque vulnerability in patients with coronary artery disease.

  12. Shear wave elastography plaque characterization with mechanical testing validation: a phantom study

    NASA Astrophysics Data System (ADS)

    Widman, E.; Maksuti, E.; Larsson, D.; Urban, M. W.; Bjällmark, A.; Larsson, M.

    2015-04-01

    Determining plaque vulnerability is critical when selecting the most suitable treatment for patients with atherosclerotic plaque. Currently, clinical non-invasive ultrasound-based methods for plaque characterization are limited to visual assessment of plaque morphology and new quantitative methods are needed. In this study, shear wave elastography (SWE) was used to characterize hard and soft plaque mimicking inclusions in six common carotid artery phantoms by using phase velocity analysis in static and dynamic environments. The results were validated with mechanical tensile testing. In the static environment, SWE measured a mean shear modulus of 5.8  ±  0.3 kPa and 106.2  ±  17.2 kPa versus 3.3  ±  0.5 kPa and 98.3  ±  3.4 kPa measured by mechanical testing in the soft and hard plaques respectively. Furthermore, it was possible to measure the plaques’ shear moduli throughout a simulated cardiac cycle. The results show good agreement between SWE and mechanical testing and indicate the possibility for in vivo arterial plaque characterization using SWE.

  13. Rupture process of the 2013 Okhotsk deep mega earthquake from iterative backprojection and compress sensing methods

    NASA Astrophysics Data System (ADS)

    Qin, W.; Yin, J.; Yao, H.

    2013-12-01

    On May 24th 2013 a Mw 8.3 normal faulting earthquake occurred at a depth of approximately 600 km beneath the sea of Okhotsk, Russia. It is a rare mega earthquake that ever occurred at such a great depth. We use the time-domain iterative backprojection (IBP) method [1] and also the frequency-domain compressive sensing (CS) technique[2] to investigate the rupture process and energy radiation of this mega earthquake. We currently use the teleseismic P-wave data from about 350 stations of USArray. IBP is an improved method of the traditional backprojection method, which more accurately locates subevents (energy burst) during earthquake rupture and determines the rupture speeds. The total rupture duration of this earthquake is about 35 s with a nearly N-S rupture direction. We find that the rupture is bilateral in the beginning 15 seconds with slow rupture speeds: about 2.5km/s for the northward rupture and about 2 km/s for the southward rupture. After that, the northward rupture stopped while the rupture towards south continued. The average southward rupture speed between 20-35 s is approximately 5 km/s, lower than the shear wave speed (about 5.5 km/s) at the hypocenter depth. The total rupture length is about 140km, in a nearly N-S direction, with a southward rupture length about 100 km and a northward rupture length about 40 km. We also use the CS method, a sparse source inversion technique, to study the frequency-dependent seismic radiation of this mega earthquake. We observe clear along-strike frequency dependence of the spatial and temporal distribution of seismic radiation and rupture process. The results from both methods are generally similar. In the next step, we'll use data from dense arrays in southwest China and also global stations for further analysis in order to more comprehensively study the rupture process of this deep mega earthquake. Reference [1] Yao H, Shearer P M, Gerstoft P. Subevent location and rupture imaging using iterative backprojection for

  14. Fault Branching and Rupture Directivity

    NASA Astrophysics Data System (ADS)

    Dmowska, R.; Rice, J. R.; Kame, N.

    2002-12-01

    Can the rupture directivity of past earthquakes be inferred from fault geometry? Nakata et al. [J. Geogr., 1998] propose to relate the observed surface branching of fault systems with directivity. Their work assumes that all branches are through acute angles in the direction of rupture propagation. However, in some observed cases rupture paths seem to branch through highly obtuse angles, as if to propagate ``backwards". Field examples of that are as follows: (1) Landers 1992. When crossing from the Johnson Valley to the Homestead Valley (HV) fault via the Kickapoo (Kp) fault, the rupture from Kp progressed not just forward onto the northern stretch of the HV fault, but also backwards, i.e., SSE along the HV [Sowers et al., 1994, Spotila and Sieh, 1995, Zachariasen and Sieh, 1995, Rockwell et al., 2000]. Measurements of surface slip along that backward branch, a prominent feature of 4 km length, show right-lateral slip, decreasing towards the SSE. (2) At a similar crossing from the HV to the Emerson (Em) fault, the rupture progressed backwards along different SSE splays of the Em fault [Zachariasen and Sieh, 1995]. (3). In crossing from the Em to Camp Rock (CR) fault, again, rupture went SSE on the CR fault. (4). Hector Mine 1999. The rupture originated on a buried fault without surface trace [Li et al., 2002; Hauksson et al., 2002] and progressed bilaterally south and north. In the south it met the Lavic Lake (LL) fault and progressed south on it, but also progressed backward, i.e. NNW, along the northern stretch of the LL fault. The angle between the buried fault and the northern LL fault is around -160o, and that NNW stretch extends around 15 km. The field examples with highly obtuse branch angles suggest that there may be no simple correlation between fault geometry and rupture directivity. We propose that an important distinction is whether those obtuse branches actually involved a rupture path which directly turned through the obtuse angle (while continuing

  15. Calculation of arterial wall temperature in atherosclerotic arteries: effect of pulsatile flow, arterial geometry, and plaque structure

    PubMed Central

    Ley, Obdulia; Kim, Taehong

    2007-01-01

    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 of rupture. As a result, monitoring plaque temperature and knowing the factors affecting it can help in the prevention of sudden rupture. Methods The transient temperature profile in inflamed atherosclerotic plaques is calculated by solving an energy equation and the Navier-Stokes equations in 2D idealized arterial models of a bending artery and an arterial bifurcation. For obtaining the numerical solution, the commercial package COMSOL 3.2 was used. The calculations correspond to a parametric study where arterial type and size, as well as plaque geometry and composition, are varied. These calculations are used to analyze the contribution of different factors affecting arterial wall temperature measurements. The main factors considered are the metabolic heat production of inflammatory cells, atherosclerotic plaque length lp, inflammatory cell layer length lmp, and inflammatory cell layer thickness dmp. Results The calculations indicate that the best location to perform the temperature measurement is at the back region of the plaque (0.5 ≤ l/lp ≤ 0.7). The location of the maximum temperature, or hot spot, at the plaque surface can move during the cardiac cycle depending on the arterial geometry and is a direct result of the blood flow pattern. For the bending artery, the hot spot moves 0.6 millimeters along the longitudinal direction; for the arterial bifurcation, the hot spot is concentrated at a single location due to the flow recirculation observed at both ends of the plaque. Focusing on the thermal history of different

  16. The prevention and regression of atherosclerotic plaques: emerging treatments

    PubMed Central

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

    2012-01-01

    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. PMID:23049260

  17. Rupture work of pendular bridges.

    PubMed

    de Boer, P C T; de Boer, M P

    2008-01-01

    Capillary bridging can generate substantial forces between solid surfaces. Impacted technologies and sciences include micro- and nanomachining, disk drive interfaces, scanning probe microscopy, biology, and granular mechanics. Existing calculations of the rupture work of capillary bridges do not consider the thermodynamics relating to the evaporation that can occur in the case of volatile liquids. Here, we show that the occurrence of evaporation decreases the rupture work by a factor of about 2. The decrease arises from heat taken from the surroundings that is converted into work. The treatment is based on a thermodynamic control-volume analysis of the pendular bridge geometry. We extend the mathematical formulation of Orr et al., solving the meniscus problem exactly for non-wetting surfaces. The extension provides analytical results for conditions at the rupture point and at a possible inflection point and for the rupture work. A simple equation (eq 32) is shown to fit the rupture work for the two cases over a meniscus curvature range of 3 orders of magnitude. Coefficients for the equation are given in tabular form for different contact angle pairs.

  18. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Saturn V Space Vehicle's induction into the National Register of Historic Places by the United States Department of the Interior.

  19. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    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.

  20. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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.

  1. Evaluation of Carotid Plaque Using Ultrasound Imaging

    PubMed Central

    2016-01-01

    Traditional risk factors for predicting of cardiovascular disease are not always effective predictors for development of cardiovascular events. This review summarizes several newly developed noninvasive imaging techniques for evaluating carotid plaques and their role in cardiovascular disease risk. PMID:27358696

  2. Nuclear envelope rupture is induced by actin-based nucleus confinement.

    PubMed

    Hatch, Emily M; Hetzer, Martin W

    2016-10-10

    Repeated rounds of nuclear envelope (NE) rupture and repair have been observed in laminopathy and cancer cells and result in intermittent loss of nucleus compartmentalization. Currently, the causes of NE rupture are unclear. Here, we show that NE rupture in cancer cells relies on the assembly of contractile actin bundles that interact with the nucleus via the linker of nucleoskeleton and cytoskeleton (LINC) complex. We found that the loss of actin bundles or the LINC complex did not rescue nuclear lamina defects, a previously identified determinant of nuclear membrane stability, but did decrease the number and size of chromatin hernias. Finally, NE rupture inhibition could be rescued in cells treated with actin-depolymerizing drugs by mechanically constraining nucleus height. These data suggest a model of NE rupture where weak membrane areas, caused by defects in lamina organization, rupture because of an increase in intranuclear pressure from actin-based nucleus confinement.

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  4. Aneurysm flow characteristics in realistic carotid artery aneurysm models induced by proximal virtual stenotic plaques: a computational hemodynamics study

    NASA Astrophysics Data System (ADS)

    Castro, Marcelo A.; Peloc, Nora L.; Chien, Aichi; Goldberg, Ezequiel; Putman, Christopher M.; Cebral, Juan R.

    2015-03-01

    Cerebral aneurysms may rarely coexist with a proximal artery stenosis. In that small percent of patients, such coexistence poses a challenge for interventional neuroradiologists and neurosurgeons to make the best treatment decision. According to previous studies, the incidence of cerebral aneurysms in patients with internal carotid artery stenosis is no greater than five percent, where the aneurysm is usually incidentally detected, being about two percent for aneurysms and stenoses in the same cerebral circulation. Those cases pose a difficult management decision for the physician. Case reports showed patients who died due to aneurysm rupture months after endarterectomy but before aneurysm clipping, while others did not show any change in the aneurysm after plaque removal, having optimum outcome after aneurysm coiling. The aim of this study is to investigate the intra-aneurysmal hemodynamic changes before and after treatment of stenotic plaque. Virtually created moderate stenoses in vascular models of internal carotid artery aneurysm patients were considered in a number of cases reconstructed from three dimensional rotational angiography images. The strategy to create those plaques was based on parameters analyzed in a previous work where idealized models were considered, including relative distance and stenosis grade. Ipsilateral and contralateral plaques were modeled. Wall shear stress and velocity pattern were computed from finite element pulsatile blood flow simulations. The results may suggest that wall shear stress changes depend on relative angular position between the aneurysm and the plaque.

  5. Simultaneous bilateral patellar tendon rupture.

    PubMed

    Moura, Diogo Lino; Marques, José Pedro; Lucas, Francisco Manuel; Fonseca, Fernando Pereira

    2017-01-01

    Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a short immobilization period and intensive rehabilitation program. Five months after surgery, the patient was able to fully participate in sport activities.

  6. Vortex dynamics in ruptured and unruptured intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Trylesinski, Gabriel

    the current hypothesized biological triggers of pathological remodeling of the artery walls. Having a good natural ratio of statuses in our IA cohort (55 unruptured vs. 19 ruptured), we were able to test the statistical significance of our predictor to fortify our findings. We also performed a distribution analysis of our cohort with respect to the number of WKV to strengthen the encouraging statistical analysis result; both analyses provided a clear good separation of the status of the aneurysms based on our predictor. Lastly, we constructed a receiver operating characteristic (ROC) curve to analyze the power different thresholds of WKV had in splitting the data in a binary way (unruptured/ruptured). The number of WKV was efficaciously able to stratify the rupture status, identifying 84.21 % of the ruptured aneurysms (with 25.45 % of false positives, i.e. unruptured IAs tagged as ruptured) when using a threshold value of 2. Our novel work undertaken to study the vortex structures in IAs brought to light interesting characteristics of the flow in the aneurysmal sac. We found that there are several distinct categories in which the aneurysm vortex topologies can be put in without relationship to the aneurysm rupture status. This first finding was in contradiction with available already-published results. Nonetheless, ruptured IAs had a statistically significant larger amount of WKV as opposed to unruptured aneurysms. This new predictor we propose to the community could very well clear a new path among the currently controversial WSS-based parameters. Although it needs to be improved to be more resilient, the first results obtained by the WKV-based parameter are promising when applied to a large dataset of 74 IAs patient-specific transient CFD simulations.

  7. Mechanical Interaction of an Expanding Coiled Stent with a Plaque-Containing Arterial Wall: A Finite Element Analysis.

    PubMed

    Welch, Tré R; Eberhart, Robert C; Banerjee, Subhash; Chuong, Cheng-Jen

    2016-03-01

    Wall injury is observed during stent expansion within atherosclerotic arteries, related in part to stimulation of the inflammatory process. Wall stress and strain induced by stent expansion can be closely examined by finite element analysis (FEA), thus shedding light on procedure-induced sources of inflammation. The purpose of this work was to use FEA to examine the interaction of a coiled polymer stent with a plaque-containing arterial wall during stent expansion. An asymmetric fibrotic plaque-containing arterial wall model was created from intravascular ultrasound (IVUS) images of a diseased artery. A 3D model for a coil stent at unexpanded state was generated in SolidWorks. They were imported into ANSYS for FEA of combined stent expansion and fibrotic plaque-distortion. We simulated the stent expansion in the plaqued lumen by increasing balloon pressure from 0 to 12 atm in 1 atm step. At increasing pressure, we examined how the expanding stent exerts forces on the fibrotic plaque and vascular wall components, and how the latter collectively resist and balance the expansive forces from the stent. Results show the expanding coiled stent creates high stresses within the plaque and the surrounding fibrotic capsule. Lower stresses were observed in adjacent medial and adventitial layers. High principal strains were observed in plaque and fibrotic capsule. The results suggest fibrotic capsule rupture might occur at localized regions. The FEA/IVUS method can be adapted for routine examination of the effects of the expansion of selected furled stents against IVUS-reconstructed diseased vessels, to improve stent deployment practices.

  8. The Dental Plaque Microbiome in Health and Disease

    PubMed Central

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

    2013-01-01

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

  9. Predictive biomechanical analysis of ascending aortic aneurysm rupture potential

    PubMed Central

    Martin, Caitlin; Sun, Wei; Pham, Thuy; Elefteriades, John

    2013-01-01

    Aortic aneurysm is a leading cause of death in adults, often taking lives without any premonitory signs or symptoms. Adverse clinical outcomes of aortic aneurysm are preventable by elective surgical repair; however, identifying at-risk individuals is difficult. The objective of this study was to perform a predictive biomechanical analysis of ascending aortic aneurysm (AsAA) tissue to assess rupture risk on a patient-specific level. AsAA tissues, obtained intra-operatively from 50 patients, were subjected to biaxial mechanical and uniaxial failure tests to obtain their passive elastic mechanical properties. A novel analytical method was developed to predict the AsAA pressure-diameter response as well as the aortic wall yield and failure responses. Our results indicated that the mean predicted AsAA diameter at rupture was 5.6 ± 0.7 cm, and the associated blood pressure to induce rupture was 579.4 ± 214.8 mmHg. Statistical analysis showed significant positive correlation between aneurysm tissue compliance and predicted risk of rupture, where patients with a pressure-strain modulus ≥100 kPa may be nearly twice as likely to experience rupture than patients with more compliant aortic tissue. The mechanical analysis of pre-dissection patient tissue properties established in this study could predict the “future” onset of yielding and rupture in AsAA patients. The analysis results implicate decreased tissue compliance as a risk factor for AsAA rupture. The presented methods may serve as a basis for the development of a pre-operative planning tool for AsAA evaluation, a tool currently unavailable. PMID:23948500

  10. Spontaneous Splenic Rupture in Melanoma

    PubMed Central

    Oryan, Ahmad; Davari, Aida; Daneshbod, Khosrow; Daneshbod, Yahya

    2014-01-01

    Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin) confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic) rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen. PMID:24795827

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

    PubMed

    Gaffar, A; Afflitto, J; Nabi, N

    1997-10-01

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

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

    SciTech Connect

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

    2009-01-01

    Amyloid beta (A{Beta}) is the primary component of Alzheimer's disease (AD) plaques, a key pathological feature of the disease. Metal ions of zinc (Zn), copper (Cu), iron (Fe), and calcium (Ca) are elevated in human amyloid plaques and are thought to be involved in neurodegeneration. Transgenic mouse models of AD also exhibit amyloid plaques, but fail to exhibit the high degree of neurodegeneration observed in humans. In this study, we imaged the Zn, Cu, Fe, and Ca ion distribution in the PSAPP transgenic mouse model representing end-stage AD (N = 6) using synchrotron X-ray fluorescence (XRF) microprobe. In order 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{beta} is thought to induce redox chemistry that is toxic to neurons, the reduced metal binding in PSAPP mice is consistent with the lack of neurodegeneration in these animals. These findings were in stark contrast to the high metal ion content observed in human AD plaques, further implicating the role of metal ions in human AD pathology.

  13. Mechanics of Multifault Earthquake Ruptures

    NASA Astrophysics Data System (ADS)

    Fletcher, J. M.; Oskin, M. E.; Teran, O.

    2015-12-01

    The 2010 El Mayor-Cucapah earthquake of magnitude Mw 7.2 produced the most complex rupture ever documented on the Pacific-North American plate margin, and the network of high- and low-angle faults activated in the event record systematic changes in kinematics with fault orientation. Individual faults have a broad and continuous spectrum of slip sense ranging from endmember dextral strike slip to normal slip, and even faults with thrust sense of dip slip were commonly observed in the aftershock sequence. Patterns of coseismic slip are consistent with three-dimensional constrictional strain and show that integrated transtensional shearing can be accommodated in a single earthquake. Stress inversions of coseismic surface rupture and aftershock focal mechanisms define two coaxial, but permuted stress states. The maximum (σ1) and intermediate (σ2) principal stresses are close in magnitude, but flip orientations due to topography- and density-controlled gradients in lithostatic load along the length of the rupture. Although most large earthquakes throughout the world activate slip on multiple faults, the mechanical conditions of their genesis remain poorly understood. Our work attempts to answer several key questions. 1) Why do complex fault systems exist? They must do something that simple, optimally-oriented fault systems cannot because the two types of faults are commonly located in close proximity. 2) How are faults with diverse orientations and slip senses prepared throughout the interseismic period to fail spontaneously together in a single earthquake? 3) Can a single stress state produce multi-fault failure? 4) Are variations in pore pressure, friction and cohesion required to produce simultaneous rupture? 5) How is the fabric of surface rupture affected by variations in orientation, kinematics, total geologic slip and fault zone architecture?

  14. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  15. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  16. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  17. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  18. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  19. DECT evaluation of noncalcified coronary artery plaque

    SciTech Connect

    Ravanfar Haghighi, Rezvan; Chatterjee, S.; Tabin, Milo; Singh, Rishi P.; Sharma, Munish; Krishna, Karthik; Sharma, Sanjiv; Jagia, Priya; Ray, Ruma; Arava, Sudhir; Yadav, Rakesh; Vani, V. C.; Lakshmi, R.; Kumar, Pratik; Mandal, Susama R.

    2015-10-15

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

  20. Direct visualization of microalgae rupture by ultrasound-driven bubbles

    NASA Astrophysics Data System (ADS)

    Pommella, Angelo; Harun, Irina; Pouliopoulos, Antonis; Choi, James J.; Hellgardt, Klaus; Garbin, Valeria

    2015-11-01

    Cell rupture induced by ultrasound is central to applications in biotechnology. For instance, cell disruption is required in the production of biofuels from microalgae (unicellular species of algae). Ultrasound-induced cavitation, bubble collapse and jetting are exploited to induce sufficiently large viscous stresses to cause rupture of the cell membranes. It has recently been shown that seeding the flow with bubbles that act as cavitation nuclei significantly reduces the energy cost for cell processing. However, a fundamental understanding of the conditions for rupture of microalgae in the complex flow fields generated by ultrasound-driven bubbles is currently lacking. We perform high-speed video microscopy to visualize the miscroscale details of the interaction of Chlamydomonas reinhardtii , microalgae of about 10 μm in size, with ultrasound-driven microbubbles of 2-200 μm in diameter. We investigate the efficiency of cell rupture depending on ultrasound frequency and pressure amplitude (from 10 kPa up to 1 MPa), and the resulting bubble dynamics regimes. In particular we compare the efficiency of membrane rupture in the acoustic microstreaming flow induced by linear oscillations, with the case of violent bubble collapse and jetting. V.G. acknowledges partial support from the European Commission (FP7-PEOPLE-2013-CIG), Grant No. 618333.

  1. Advancements in identifying biomechanical determinants for abdominal aortic aneurysm rupture.

    PubMed

    Kontopodis, Nikolaos; Metaxa, Eleni; Papaharilaou, Yannis; Tavlas, Emmanouil; Tsetis, Dimitrios; Ioannou, Christos

    2015-02-01

    Abdominal aortic aneurysms are a common health problem and currently the need for surgical intervention is determined based on maximum diameter and growth rate criteria. Since these universal variables often fail to predict accurately every abdominal aortic aneurysms evolution, there is a considerable effort in the literature for other markers to be identified towards individualized rupture risk estimations and growth rate predictions. To this effort, biomechanical tools have been extensively used since abdominal aortic aneurysm rupture is in fact a material failure of the diseased arterial wall to compensate the stress acting on it. The peak wall stress, the role of the unique geometry of every individual abdominal aortic aneurysm as well as the mechanical properties and the local strength of the degenerated aneurysmal wall, all confer to rupture risk. In this review article, the assessment of these variables through mechanical testing, advanced imaging and computational modeling is reviewed and the clinical perspective is discussed.

  2. Localized pleural plaques and lung cancer

    SciTech Connect

    Partanen, T.; Nurminen, M.; Zitting, A.; Koskinen, H.; Wiikeri, M.; Ahlman, K. )

    1992-01-01

    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.

  3. Functional expression of dental plaque microbiota

    PubMed Central

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

    2014-01-01

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

  4. Measurement of fibrous cap thickness in atherosclerotic plaques by spatiotemporal analysis of laser speckle images

    NASA Astrophysics Data System (ADS)

    Nadkarni, Seemantini K.; Bilenca, Alberto; Bouma, Brett E.; Tearney, Guillermo J.

    2006-03-01

    Necrotic-core fibroatheromas (NCFA) with thin, mechanically weak fibrous caps overlying lipid cores comprise the majority of plaques that rupture and cause acute myocardial infarction. Laser speckle imaging (LSI) has been recently demonstrated to enable atherosclerotic plaque characterization with high accuracy. We investigate spatio-temporal analysis of LSI data, in conjunction with diffusion theory and Monte Carlo modeling of light transport, to estimate fibrous cap thickness in NCFAs. Time-varying laser speckle images of 20 NCFAs are selected for analysis. Spatio-temporal intensity fluctuations are analyzed by exponential fitting of the windowed normalized cross-correlation of sequential laser speckle patterns to obtain the speckle decorrelation time constant, τ(ρ), as a function of distance ρ from the source entry location. The distance, ρ‧, at which τ(ρ) dropped to 65% of its maximum value is recorded. Diffusion theory and Monte Carlo models are utilized to estimate the maximum photon penetration depth, zmax(ρ‧), for a distance equal to ρ‧, measured from LSI. Measurements of zmax(ρ‧) correlate well with histological measurements of fibrous cap thickness (R=0.78,p<0.0001), and paired t-tests show no significant difference between the groups (p=0.4). These results demonstrate that spatio-temporal LSI may allow the estimation of fibrous cap thickness in NCFAs, which is an important predictor of plaque stability.

  5. Plaque assay for virulent Legionella pneumophila.

    PubMed Central

    Fernandez, R C; Lee, S H; Haldane, D; Sumarah, R; Rozee, K R

    1989-01-01

    Methods of assessing virulence of Legionella pneumophila, the etiologic agent of Legionnaires disease, include the infection of guinea pigs, fertile chicken eggs, and mammalian and protozoan cell cultures. Guinea pig assays, in particular, are expensive, laborious, or unsuitable for routine screening of Legionella isolates. We have developed a virulence assay that requires the enumeration of viruslike plaques which are the result of virulent L. pneumophila infecting mouse L929 cells. Each plaque is the consequence of the initial infection of an L cell with a single bacterium. A nonvirulent mutant derived from the serial passage of virulent L. pneumophila on Mueller-Hinton agar fails to survive within L cells and consequently fails to produce plaques. Images PMID:2674192

  6. Integrated IVUS-OCT Imaging for Atherosclerotic Plaque Characterization

    PubMed Central

    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

    2014-01-01

    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. PMID:24771992

  7. Association between Randall's Plaque and Calcifying Nanoparticles

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  8. Variable land-level changes at a non-persistent megathrust rupture boundary, Sitkinak Island, Alaska

    NASA Astrophysics Data System (ADS)

    Briggs, R. W.; Engelhart, S. E.; Nelson, A. R.; Kemp, A.; Haeussler, P. J.; Dura, T.

    2013-12-01

    Fault-rupture segmentation models require paleoseismic data to validate inferred rupture boundaries. We examined the southwestern end of the 1964 Mw 9.2 rupture along the Alaska-Aleutian megathrust to test the prehistoric persistence of this historical rupture boundary. On Sitkinak Island in the Trinity Islands, 20 hand-collected cores and tidal outcrops beneath tidal and freshwater marshes reveal five abrupt lithologic contacts that record a mixed record of coseismic uplift (3 events) and subsidence (2 events) in the last ~1000 years. Diatom and foraminiferal assemblages in modern and core material obtained from the southwestern Sitkinak lagoon indicate rapid uplift ca. AD 1788 and just prior to 575 × 65 cal yr and 735 × 65 cal yr; and rapid subsidence in AD 1964 and soon after ~735 cal yr as constrained by 14C ages and tephra correlation. Because the northern coast of Sitkinak was reportedly uplifted in AD 1964 and the island is currently subsiding interseismically above a locked patch of the megathrust, we interpret coseismic subsidence as representing the along-strike transition from elastic uplift to subsidence at the rupture boundary; this implies that the AD 1964 zero uplift isobase crosses the island. Similar behavior has been observed during large megathrust ruptures in Indonesia and the Solomon Islands and is predicted by elastic dislocation models. A sand bed traced inland 1.5 km and bracketed with 14C, 137Cs, and 210Pb ages was most likely deposited by a tsunami associated with megathrust rupture in 1788. Historical records suggest that the AD 1788 rupture extended from the southwest at least 100 km northeast to the Russian settlement at Three Saints Bay near Old Harbor, Kodiak Island. The complicated uplift and subsidence record we observe on Sitkinak Island, interpreted in the context of historical reports of the AD 1788 rupture, is consistent with at least three rupture segmentation models. In Model A, Sitkinak is located at a boundary for 1964

  9. Overexpression of Prolyl-4-Hydroxylase-α1 Stabilizes but Increases Shear Stress-Induced Atherosclerotic Plaque in Apolipoprotein E-Deficient Mice

    PubMed Central

    Liu, Xin-xin; Li, Meng-meng; Zhang, Yu; Chen, Liang; Wang, Lin; Di, Ming-xue

    2016-01-01

    The rupture and erosion of atherosclerotic plaque can induce coronary thrombosis. Prolyl-4-hydroxylase (P4H) plays a central role in the synthesis of all known types of collagens, which are the most abundant constituent of the extracellular matrix in atherosclerotic plaque. The pathogenesis of atherosclerosis is thought to be in part caused by shear stress. In this study, we aimed to investigate a relationship between P4Hα1 and shear stress-induced atherosclerotic plaque. Carotid arteries of ApoE−/− mice were exposed to low and oscillatory shear stress conditions by the placement of a shear stress cast for 2 weeks; we divided 60 male ApoE−/− mice into three groups for treatments with saline (mock) (n = 20), empty lentivirus (lenti-EGFP) (n = 20), and lentivirus-P4Hα1 (lenti-P4Hα1) (n = 20). Our results reveal that after 2 weeks of lenti-P4Hα1 treatment both low and oscillatory shear stress-induced plaques increased collagen and the thickness of fibrous cap and decreased macrophage accumulation but no change in lipid accumulation. We also observed that overexpression of P4Ha1 increased plaque size. Our study suggests that P4Hα1 overexpression might be a potential therapeutic target in stabilizing vulnerable plaques. PMID:27818566

  10. In search of the "vulnerable plaque": can it be localized and will focal regional therapy ever be an option for cardiac prevention?

    PubMed

    Ambrose, John A

    2008-04-22

    The search to find the location of future plaque ruptures or plaque erosions leading to myocardial infarction (so-called "vulnerable plaques") is an important area of cardiovascular research. Systemic therapy, including use of statins, targets the vulnerable patient. However, adverse events cannot be completely eliminated with the appropriate application of systemic therapies and thus has given rise to the possibility of local or regional therapy of "vulnerable plaques" to prevent future events. Until now, no criteria have been developed for consideration of this therapy. For such a strategy to work, there should be several prerequisites. These involve the identification of susceptible lesions, the number of lesions, their natural history, and proof that an interventional technique is preferable to medical therapy alone. The greatest deficiency relates to the fact that until the natural history of presumed "vulnerable plaques" is known one can never truly identify what constitutes a "vulnerable plaque." Much work needs to be done in this area, but ongoing and new trials should provide important information that could potentially change drastically how coronary artery disease is diagnosed and treated.

  11. Detection of vulnerable atherosclerosis plaques with a dual-modal single-photon-emission computed tomography/magnetic resonance imaging probe targeting apoptotic macrophages.

    PubMed

    Cheng, Dengfeng; Li, Xiao; Zhang, Chunfu; Tan, Hui; Wang, Cong; Pang, Lifang; Shi, Hongcheng

    2015-02-04

    Atherosclerosis (AS), especially the vulnerable AS plaque rupture-induced acute obstructive vascular disease, is a leading cause of death. Accordingly, there is a need for an effective method to draw accurate predictions about AS progression and plaque vulnerability. Herein we report on an approach to constructing a hybrid nanoparticle system using a single-photon-emission computed tomography (SPECT)/magnetic resonance imaging (MRI) multimodal probe, aiming for a comprehensive evaluation of AS progression by achieving high sensitivity along with high resolution. Ultrasmall superparamagnetic iron oxide (USPIO) was covered by aminated poly(ethylene glycol) (PEG) and carboxylated PEG simultaneously and then functionalized with diethylenetriaminepentacetate acid for (99m)Tc coordination and subsequently Annexin V for targeting apoptotic macrophages abundant in vulnerable plaques. The in vivo accumulations of imaging probe reflected by SPECT and MRI were consistent and accurate in highlighting lesions. Intense radioactive signals detected by SPECT facilitated focus recognization and quantification, while USPIO-based T2-weighted MRI improved the focal localization and volumetry of AS plaques. For subsequent ex vivo planar images, targeting effects were further confirmed by immunohistochemistry, including CD-68 and TUNEL staining; meanwhile, the degree of concentration was proven to be statistically correlated with the Oil Red O staining results. In conclusion, these results indicated that the Annexin V-modified hybrid nanoparticle system specifically targeted the vulnerable AS plaques containing apoptotic macrophages and could be of great value in the invasively accurate detection of vulnerable plaques.

  12. Molecular dynamics of interface rupture

    NASA Technical Reports Server (NTRS)

    Koplik, Joel; Banavar, Jayanth R.

    1993-01-01

    Several situations have been studied in which a fluid-vapor or fluid-fluid interface ruptures, using molecular dynamics simulations of 3000 to 20,000 Lennard-Jones molecules in three dimensions. The cases studied are the Rayleigh instability of a liquid thread, the burst of a liquid drop immersed in a second liquid undergoing shear, and the rupture of a liquid sheet in an extensional flow. The late stages of the rupture process involve the gradual withdrawal of molecules from a thinning neck, or the appearance and growth of holes in a sheet. In all cases, it is found that despite the small size of the systems studied, tens of angstroms, the dynamics is in at least qualitative accord with the behavior expected from continuum calculations, and in some cases the agreement is to within tens of percent. Remarkably, this agreement occurs even though the Eulerian velocity and stress fields are essentially unmeasurable - dominated by thermal noise. The limitations and prospects for such molecular simulation techniques are assessed.

  13. Rupture of vertical soap films

    NASA Astrophysics Data System (ADS)

    Rio, Emmanuelle

    2014-11-01

    Soap films are ephemeral and fragile objects. They tend to thin under gravity, which gives rise to the fascinating variations of colors at their interfaces but leads systematically to rupture. Even a child can create, manipulate and admire soap films and bubbles. Nevertheless, the reason why it suddenly bursts remains a mystery although the soap chosen to stabilize the film as well as the humidity of the air seem very important. One difficulty to study the rupture of vertical soap films is to control the initial solution. To avoid this problem we choose to study the rupture during the generation of the film at a controlled velocity. We have built an experiment, in which we measure the maximum length of the film together with its lifetime. The generation of the film is due to the presence of a gradient of surface concentration of surfactants at the liquid/air interface. This leads to a Marangoni force directed toward the top of the film. The film is expected to burst only when its weight is not balanced anymore by this force. We will show that this leads to the surprising result that the thicker films have shorter lifetimes than the thinner ones. It is thus the ability of the interface to sustain a surface concentration gradient of surfactants which controls its stability.

  14. Arterial luminal curvature and fibrous-cap thickness affect critical stress conditions within atherosclerotic plaque: an in vivo MRI-based 2D finite-element study.

    PubMed

    Teng, Zhongzhao; Sadat, Umar; Li, Zhiyong; Huang, Xueying; Zhu, Chengcheng; Young, Victoria E; Graves, Martin J; Gillard, Jonathan H

    2010-10-01

    High mechanical stress in atherosclerotic plaques at vulnerable sites, called critical stress, contributes to plaque rupture. The site of minimum fibrous cap (FC) thickness (FC(MIN)) and plaque shoulder are well-documented vulnerable sites. The inherent weakness of the FC material at the thinnest point increases the stress, making it vulnerable, and it is the big curvature of the lumen contour over FC which may result in increased plaque stress. We aimed to assess critical stresses at FC(MIN) and the maximum lumen curvature over FC (LC(MAX)) and quantify the difference to see which vulnerable site had the highest critical stress and was, therefore, at highest risk of rupture. One hundred patients underwent high resolution carotid magnetic resonance (MR) imaging. We used 352 MR slices with delineated atherosclerotic components for the simulation study. Stresses at all the integral nodes along the lumen surface were calculated using the finite-element method. FC(MIN) and LC(MAX) were identified, and critical stresses at these sites were assessed and compared. Critical stress at FC(MIN) was significantly lower than that at LC(MAX) (median: 121.55 kPa; inter quartile range (IQR) = [60.70-180.32] kPa vs. 150.80 kPa; IQR = [91.39-235.75] kPa, p < 0.0001). If critical stress at FC(MIN) was only used, then the stress condition of 238 of 352 MR slices would be underestimated, while if the critical stress at LC(MAX) only was used, then 112 out of 352 would be underestimated. Stress analysis at FC(MIN) and LC(MAX) should be used for a refined mechanical risk assessment of atherosclerotic plaques, since material failure at either site may result in rupture.

  15. Simulations of Transcatheter Aortic Valve Implantation – Implications for Aortic Root Rupture

    PubMed Central

    Wang, Qian; Kodali, Susheel; Primiano, Charles; Sun, Wei

    2014-01-01

    Objectives Aortic root rupture is one of the most severe complications of transcatheter aortic valve implantation (TAVI). The mechanism of this adverse event remains mostly unknown. The purpose of this study was to obtain a better understanding of the biomechanical interaction between the tissue and stent for patients with a high risk of aortic rupture. Methods We simulated the stent deployment process of three TAVI patients with high aortic rupture risk using finite element method. The first case was a retrospective analysis of an aortic rupture case, while the other two cases were prospective studies, which ended with one cancelled procedure and one successful TAVI. Simulation results were evaluated for the risk of aortic root rupture, as well as coronary artery occlusion, and paravalvular leak. Results For Case 1, the simulated aortic rupture location was the same as clinical observations. From the simulation results, it can be seen that the large calcified spot on the interior of the left coronary sinus between coronary ostium and the aortic annulus was pushed by the stent, causing the aortic rupture. For Case 2 and Case 3, predicated results from the simulations were presented to the clinicians at pre-procedure meetings; and they were in agreement with clinician’s observations and decisions. Conclusions Our results indicated that the engineering analysis could provide additional information to help clinicians evaluate complicated, high risk aortic rupture cases. Since a systematic study of a large patient cohort of aortic rupture is currently not available (due to the low occurrence rate) to clearly understand underlying rupture mechanisms, case by case engineering analysis is recommended for evaluating patient-specific aortic rupture risk. PMID:24736808

  16. Carotid plaque elasticity estimation using ultrasound elastography, MRI, and inverse FEA - A numerical feasibility study.

    PubMed

    Nieuwstadt, H A; Fekkes, S; Hansen, H H G; de Korte, C L; van der Lugt, A; Wentzel, J J; van der Steen, A F W; Gijsen, F J H

    2015-08-01

    The material properties of atherosclerotic plaques govern the biomechanical environment, which is associated with rupture-risk. We investigated the feasibility of noninvasively estimating carotid plaque component material properties through simulating ultrasound (US) elastography and in vivo magnetic resonance imaging (MRI), and solving the inverse problem with finite element analysis. 2D plaque models were derived from endarterectomy specimens of nine patients. Nonlinear neo-Hookean models (tissue elasticity C1) were assigned to fibrous intima, wall (i.e., media/adventitia), and lipid-rich necrotic core. Finite element analysis was used to simulate clinical cross-sectional US strain imaging. Computer-simulated, single-slice in vivo MR images were segmented by two MR readers. We investigated multiple scenarios for plaque model elasticity, and consistently found clear separations between estimated tissue elasticity values. The intima C1 (160 kPa scenario) was estimated as 125.8 ± 19.4 kPa (reader 1) and 128.9 ± 24.8 kPa (reader 2). The lipid-rich necrotic core C1 (5 kPa) was estimated as 5.6 ± 2.0 kPa (reader 1) and 8.5 ± 4.5 kPa (reader 2). A scenario with a stiffer wall yielded similar results, while realistic US strain noise and rotating the models had little influence, thus demonstrating robustness of the procedure. The promising findings of this computer-simulation study stimulate applying the proposed methodology in a clinical setting.

  17. Association between Randall's Plaque and Calcifying Nanoparticles

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  18. Adalimumab: A Review in Chronic Plaque Psoriasis.

    PubMed

    Burness, Celeste B; McKeage, Kate

    2015-12-01

    Adalimumab (Humira(®)) is a fully human monoclonal antibody against tumour necrosis factor (TNF), formulated for subcutaneous administration. It is well established in the treatment of adults with moderate-to-severe chronic plaque psoriasis and has recently received approval in the EU for the treatment of severe chronic plaque psoriasis in children and adolescents from 4 years of age. In a phase III trial in paediatric patients, a significantly greater proportion of patients receiving adalimumab 0.8 mg/kg (to a maximum of 40 mg) every other week (eow) achieved a ≥75 % improvement from baseline in Psoriasis Area and Severity Index than those receiving methotrexate after 16 weeks of treatment. In adults, well-designed randomized clinical trials demonstrated that adalimumab 40 mg eow effectively reduced the signs and symptoms of psoriasis and improved dermatology-specific and general measures of health-related quality of life, with these benefits sustained during long-term treatment. Adalimumab was generally well tolerated, compared with placebo or methotrexate, during clinical trials in paediatric and adult patients with chronic plaque psoriasis. Thus, adalimumab remains an important treatment strategy in adults with moderate-to-severe chronic plaque psoriasis and provides a promising new systemic treatment option for children and adolescents from 4 years of age with severe psoriasis.

  19. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the designation of the Propulsion and Structural Test Facility as a National Historic Landmark by the National Park Service of the United States Interior. The site was designated as a landmark in 1985.

  20. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Redstone Test Stand as a National Historic Landmark. The site was designated as such in 1985 by the National Park Service of the United States Department of the Interior.

  1. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Saturn V Dynamic Test Stand as a National Historic Landmark. The site was designated as such in 1985 by the National Park Service of the United States Department of the Interior.

  2. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama, commemorates the Saturn V Launch Vehicle as a National Historic Landmark. The site was designated as such in 1984 by the National Park Service of the United States Department of the Interior.

  3. Historical Plaque at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This plaque, displayed on the grounds of Marshall Space Flight Center in Huntsville, Alabama commemorates the Neutral Buoyancy Space Simulator as a National Historic Landmark. The site was designated as such in 1986 by the National Park Service of the United States Department of the Interior.

  4. High rate internal pressurization of the human eye to determine dynamic rupture pressure.

    PubMed

    Bisplinghoff, Jill A; McNally, Craig; Yang, Siyang; Herring, Ian P; Brozoski, Fred T; Duma, Stefan M

    2008-01-01

    Over 1.9 million people suffer from eye injuries in the United States, occurring from automobile accidents, sports related impacts, and military combat. The purpose of the current study is to analyze the rupture pressure of human eyes using a high rate pressurization system. Internal pressure was dynamically induced into the eye with a drop tower pressurization system. The rupture pressure was measured with a small pressure sensor inserted into the optic nerve. A total of 10 human eye dynamic pressure tests were performed to determine rupture pressure and to compare the results with previous data. It was found that the average high rate rupture pressure of human eyes is 0.89+/- 0.25 MPa. In comparing these data with previous studies, it is concluded that as the loading rate increases the rupture pressure also increases.

  5. BATON ROUGE NATIONAL CEMETERY PLAQUE MOUNTED ON BASE OF FLAGPOLE, ...

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

    BATON ROUGE NATIONAL CEMETERY PLAQUE MOUNTED ON BASE OF FLAGPOLE, WITH NATIONAL REGISTER OF HISTORIC PLACES PLAQUE AT RIGHT. VIEW TO NORTH. - Baton Rouge National Cemetery, 220 North 19th Street, Baton Rouge, East Baton Rouge Parish, LA

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

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

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

  7. Ground motion hazard from supershear rupture

    USGS Publications Warehouse

    Andrews, D.J.

    2010-01-01

    An idealized rupture, propagating smoothly near a terminal rupture velocity, radiates energy that is focused into a beam. For rupture velocity less than the S-wave speed, radiated energy is concentrated in a beam of intense fault-normal velocity near the projection of the rupture trace. Although confined to a narrow range of azimuths, this beam diverges and attenuates. For rupture velocity greater than the S-wave speed, radiated energy is concentrated in Mach waves forming a pair of beams propagating obliquely away from the fault. These beams do not attenuate until diffraction becomes effective at large distance. Events with supershear and sub-Rayleigh rupture velocity are compared in 2D plane-strain calculations with equal stress drop, fracture energy, and rupture length; only static friction is changed to determine the rupture velocity. Peak velocity in the sub-Rayleigh case near the termination of rupture is larger than peak velocity in the Mach wave in the supershear case. The occurrence of supershear rupture propagation reduces the most intense peak ground velocity near the fault, but it increases peak velocity within a beam at greater distances. ?? 2010.

  8. Ruptured Tendons in Anabolic-Androgenic Steroid Users: A Cross-Sectional Cohort Study

    PubMed Central

    Kanayama, Gen; DeLuca, James; Meehan, William P.; Hudson, James I.; Isaacs, Stephanie; Baggish, Aaron; Weiner, Rory; Micheli, Lyle; Pope, Harrison G.

    2016-01-01

    Background Accumulating case reports have described tendon rupture in men using anabolic-androgenic steroids (AAS). However no controlled study, to our knowledge, has assessed history of tendon rupture in a large cohort of AAS users and comparison nonusers. Hypothesis We hypothesized that men reporting long-term AAS abuse would report an elevated lifetime incidence of tendon rupture as compared to non-AAS-using bodybuilders. Study Design Cross-sectional cohort study. Methods We obtained medical histories from 142 experienced male bodybuilders age 35–55, recruited in the course of two studies. Of these men, 88 reported at least two years of cumulative lifetime AAS use and 54 reported no history of AAS use. In men reporting a history of tendon rupture, we recorded circumstances of the injury, prodromal symptoms, concomitant drug or alcohol use, and details of current and lifetime AAS use if applicable. We also obtained surgical records for most participants. Results Nineteen (22%) of the AAS users, but only 3 (6%) of the nonusers reported at least one lifetime tendon rupture. The hazard ratio (95% confidence interval) for a first ruptured tendon in AAS users versus nonusers was 9.0 (2.5, 32.3); P <.001. Several men reported two or more independent lifetime tendon ruptures. Interestingly, upper body tendon ruptures occurred exclusively in the AAS group (15 [17%] of the AAS users versus 0 non-users; risk difference 0.17 (0.09, 0.25); P < 0.001 [hazard ratio not estimable]), whereas we found no significant difference between users and nonusers in risk for lower body ruptures (6 [7%] AAS users, 3 [6%] nonusers; hazard ratio 3.1 (0.7, 13.8), P = 0.13). Of 31 individual tendon ruptures that we assessed, only 6 (19%) occurred while weightlifting, with the majority occurring during other sports activities. Eight (26%) ruptures followed prodromal symptoms of nonspecific pain in the region. Virtually all ruptures were treated surgically with complete or near

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-28

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

  11. Effects of insulin sensitizers on plaque vulnerability associated with elevated lipid content in atheroma in ApoE-knockout mice.

    PubMed

    Cefalu, W T; Wang, Z Q; Schneider, D J; Absher, P M; Baldor, L C; Taatjes, D J; Sobel, B E

    2004-03-01

    Acute coronary syndromes are generally precipitated by rupture of lipid-laden, relatively acellular, vulnerable atherosclerotic plaques with thin fibrous caps. We investigated whether a high-fat diet alters insulin sensitivity and whether insulin sensitizers (troglitazone and rosiglitazone) alter the composition of otherwise lipidladen atherosclerotic plaques in mice deficient in apolipoprotein E (ApoE). ApoE-knockout mice were fed a high-fat (n=30) or standard chow (n=10) diet for two weeks. Thereafter, those fed the high-fat diet were treated with troglitazone (n=10), rosiglitazone (n=10) or no drug (n=10) for 16 weeks beginning at 8 weeks of age. Carbohydrate metabolism was assessed with intraperitoneal glucose tolerance tests and insulin tolerance tests. Plaque composition was characterised with confocal laser scanning microscopy. The high-fat diet induced insulin resistance in the absence of weight gain. Compared with control animals on the high-fat diet, animals given troglitazone (400 mg/kg/day) or rosiglitazone (4 mg/kg/day) had significantly less area under the curve (AUC) for insulin ( p<0.05) and glucose disposal ( p<0.05). Despite significant increases in insulin sensitivity with drug treatment, no change in HDL-cholesterol and triglyceride levels, nor reduction in atheroma size or lipid content was noted. Thus, improvement in insulin resistance induced by a high-fat diet in this animal model of vasculopathy did not alter plaque composition.

  12. Requirements for imaging vulnerable plaque in the coronary artery using a coded aperture imaging system

    NASA Astrophysics Data System (ADS)

    Tozian, Cynthia

    A coded aperture1 plate was employed on a conventional gamma camera for 3D single photon emission computed tomography (SPECT) imaging on small animal models. The coded aperture design was selected to improve the spatial resolution and decrease the minimum detectable activity (MDA) required to image plaque formation in the APoE (apolipoprotein E) gene deficient mouse model when compared to conventional SPECT techniques. The pattern that was tested was a no-two-holes-touching (NTHT) modified uniformly redundant array (MURA) having 1,920 pinholes. The number of pinholes combined with the thin sintered tungsten plate was designed to increase the efficiency of the imaging modality over conventional gamma camera imaging methods while improving spatial resolution and reducing noise in the image reconstruction. The MDA required to image the vulnerable plaque in a human cardiac-torso mathematical phantom was simulated with a Monte Carlo code and evaluated to determine the optimum plate thickness by a receiver operating characteristic (ROC) yielding the lowest possible MDA and highest area under the curve (AUC). A partial 3D expectation maximization (EM) reconstruction was developed to improve signal-to-noise ratio (SNR), dynamic range, and spatial resolution over the linear correlation method of reconstruction. This improvement was evaluated by imaging a mini hot rod phantom, simulating the dynamic range, and by performing a bone scan of the C-57 control mouse. Results of the experimental and simulated data as well as other plate designs were analyzed for use as a small animal and potentially human cardiac imaging modality for a radiopharmaceutical developed at Bristol-Myers Squibb Medical Imaging Company, North Billerica, MA, for diagnosing vulnerable plaques. If left untreated, these plaques may rupture causing sudden, unexpected coronary occlusion and death. The results of this research indicated that imaging and reconstructing with this new partial 3D algorithm improved

  13. Patterns of Therapeutic Alliance: Rupture-Repair Episodes in Prolonged Exposure for PTSD

    PubMed Central

    McLaughlin, AnnaMaria Aguirre; Keller, Stephanie M.; Feeny, Norah C.; Youngstrom, Eric A.; Zoellner, Lori A.

    2014-01-01

    Objective To better understand the role of therapeutic alliance in PTSD treatment, we examined patterns of and shifts in alliance. First, we identified individuals with repaired ruptures, unrepaired ruptures, and no ruptures in alliance. Then, we explored group differences in these alliance events for clients with common clinical correlates (i.e., co-occurring depression and childhood abuse history) and whether or not the presence of these events influenced treatment outcome. Method At pre-treatment, clients (N = 116); 76.1% female; 66% Caucasian; age M = 36.7 years (SD = 11.3) completed measures assessing PTSD diagnosis and severity (PTSD Symptom Scale Interview and Self-Report), depression diagnosis and severity (Structured Clinical Interview for DSM-IV and Beck Depression Inventory), and trauma history. During ten weeks of prolonged exposure therapy, alliance (California Psychotherapy Alliance Scale) measures were completed. At post-treatment, PTSD and depression were re-assessed. Results Ruptures in alliance were quite common (46%). No significant differences emerged in the frequency of repaired ruptures, unrepaired ruptures, or no ruptures between those with and without co-occurring MDD, X2 (2, N = 82) = 2.69, p =. 26, or those with and without a history of childhood abuse, X2 (2, N = 81) = 0.57, p = .75. Unrepaired ruptures predicted worse treatment outcome (β = .45, p = .001). Conclusions The current study underscores the importance of attending to discontinuities in alliance throughout treatment. PMID:24188510

  14. Cosmonaut Leonov and Astronaut Stafford display ASTP commemorative plaque

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Cosmonaut Aleksey A. Leonov (on left) and Astronaut Thomas P. Stafford display the Apollo Soyuz Test Project (ASTP) commemorative plaque. The two commanders of their respective crews are in the Apollo Command Module trainer in bldg 35 at JSC. The two plaques divided into four quarters each will be flown on the ASTP mission. The plaque is written in both English and Russian.

  15. 99mTc-labelled anti-CD11b SPECT/CT imaging allows detection of plaque destabilization tightly linked to inflammation

    PubMed Central

    Liu, Guobing; Hu, Yan; Xiao, Jie; Li, Xiao; Li, Yanli; Tan, Hui; Zhao, Yanzhao; Cheng, Dengfeng; Shi, Hongcheng

    2016-01-01

    It remains challenging to predict the risk of rupture for a specific atherosclerotic plaque timely, a thrombotic trigger tightly linked to inflammation. CD11b, is a biomarker abundant on inflammatory cells, not restricted to monocytes/macrophages. In this study, we fabricated a probe named as 99mTc-MAG3-anti-CD11b for detecting inflamed atherosclerotic plaques with single photon emission computed tomography/computed tomography (SPECT/CT). The ApoE-knockout (ApoE−/−) mice were selected to establish animal models, with C57BL/6J mice used for control. A higher CD11b+-cell recruitment with higher CD11b expression and more serious whole-body inflammatory status were identified in ApoE−/− mice. The probe showed high in vitro affinity and specificity to the Raw-264.7 macrophages, as well as inflammatory cells infiltrated in atherosclerotic plaques, either in ex vivo fluorescent imaging or in in vivo micro-SPECT/CT imaging, which were confirmed by ex vivo planar gamma imaging, Oil-Red-O staining and CD11b-immunohistochemistry staining. A significant positive relationship was identified between the radioactivity intensity on SPECT/CT images and the CD11b expression in plaques. In summary, this study demonstrates the feasibility of anti-CD11b antibody mediated noninvasive SPECT/CT imaging of inflammatory leukocytes in murine atherosclerotic plaques. This imaging strategy can identify inflammation-rich plaques at risk for rupture and evaluate the effectiveness of inflammation-targeted therapies in atheroma. PMID:26877097

  16. Investigation of cryogenic rupture disc design

    NASA Technical Reports Server (NTRS)

    Keough, J. B.; Oldland, A. H.

    1973-01-01

    Rupture disc designs of both the active (command actuated) and passive (pressure ruptured) types were evaluated for performance characteristics at cryogenic temperatures and for capability to operate in a variety of cryogens, including gaseous and liquid fluorine. The test results, coupled with information from literature and industry searches, were used to establish a statement of design criteria and recommended practices for application of rupture discs to cryogenic rocket propellant feed and vent systems.

  17. Ruptured jejunum following Heimlich maneuver.

    PubMed

    Razaboni, R M; Brathwaite, C E; Dwyer, W A

    1986-01-01

    The Heimlich maneuver, over time, has proved to be a useful resuscitative procedure in the management of cases with airway occlusion secondary to foreign body. Medical treatments, however, can have side effects, and this maneuver is no exception. A previously unreported complication is presented, that of jejunal rupture. The proper application of the maneuver minimizes the number of side effects; however, since they do occur, it is suggested that all persons subject to this maneuver be subsequently evaluated by a physician as soon after the incident as is practicable.

  18. Indocyanine green enables near-infrared fluorescence imaging of lipid-rich, inflamed atherosclerotic plaques.

    PubMed

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

    2011-05-25

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

  19. Objective quantification of plaque using digital image analysis.

    PubMed

    Sagel, P A; Lapujade, P G; Miller, J M; Sunberg, R J

    2000-01-01

    Dental plaque is the precursor to many oral diseases (e.g. gingivitis, periodontitis, caries) and thus its removal and control are an important aspect of oral hygiene. Many of the oral care products available today remove or inhibit the growth of dental plaque. Historically, the antiplaque efficacy of products was measured in blinded clinical trials where the amount of plaque on teeth is assessed via subjective visual grading with predefined scales such as the Turesky index. The ability of the examiner to consistently apply the index over time and the sensitivity of the scales often leads to large, expensive clinical trials. The present invention is an automatic measurement of plaque coverage on the facial surfaces of teeth using a digital image analysis technique. Dental plaque disclosed with fluorescein is digitally imaged under long-wave ultraviolet light. Ultraviolet illumination of fluorescein-disclosed plaque produces an image where the pixels of the image can be categorically classified based on color into one of five classes: teeth; plaque; gingiva; plaque on gingiva, or lip retractors. The amount of plaque on teeth can be determined by summation of the number of plaque pixels. The percent coverage is calculated from the number of plaque pixels and teeth pixels in the image. The digital image analysis of plaque allows facial plaque levels to be precisely measured (RSD = 3.77%). In application, the digital image analysis of plaque is capable of measuring highly significant plaque growth inhibition of a stannous fluoride dentifrice with as few as 10 subjects in a cross-over design.

  20. Acute Pectoralis Major Rupture Captured on Video

    PubMed Central

    Valencia Mora, María

    2016-01-01

    Pectoralis major (PM) ruptures are uncommon injuries, although they are becoming more frequent. We report a case of a PM rupture in a young male who presented with axillar pain and absence of the anterior axillary fold after he perceived a snap while lifting 200 kg in the bench press. Diagnosis of PM rupture was suspected clinically and confirmed with imaging studies. The patient was treated surgically, reinserting the tendon to the humerus with suture anchors. One-year follow-up showed excellent results. The patient was recording his training on video, so we can observe in detail the most common mechanism of injury of PM rupture. PMID:27595030

  1. [From myocardium to the atherosclerotic plaque: new perspectives in cardiologic imaging].

    PubMed

    Gargiulo, Paola; D'Amore, Carmen; Dellegrottaglie, Santo; Leosco, Dario; Rengo, Giuseppe; Musella, Francesca; Pirozzi, Elisabetta; Mosca, Susanna; Casaretti, Laura; Formisano, Roberto; Bologna, Ada; Parente, Antonio; Conte, Sirio; Perrone-Filardi, Pasquale

    2011-06-01

    Molecular imaging is an innovative and promising approach in cardiology for functional characterization of atherosclerosis. Nuclear, ultrasound and magnetic resonance imaging have been used for assessment of atherosclerosis of large and small arteries in several clinical and experimental studies. Positron Emission Tomography with fluorodeoxyglucose can measure metabolic activity and vulnerability of atherosclerotic plaques, identifying individuals at risk of future cardiovascular events. Magnetic resonance imaging can quantify carotid artery inflammation using iron oxide nanoparticles as contrast agent. In addition, macrophage accumulation of iron particles in atherosclerotic plaques may allow monitoring of inflammation during drug therapy, whereas contrast-enhanced ultrasound imaging may detect plaque neovascularization. Currently, technical factors, including cardiac and diaphragmatic motion and small size of coronary vessels, limit routine application of these techniques for coronary imaging. Purpose of this review is to describe state of the art and potential areas of clinical applications of molecular imaging of atherosclerosis.

  2. Preclinical Properties of 18F-AV-45: A PET Agent for Aβ Plaques in the Brain

    PubMed Central

    Choi, Seok Rye; Golding, Geoff; Zhuang, Zhiping; Zhang, Wei; Lim, Nathaniel; Hefti, Franz; Benedum, Tyler E.; Kilbourn, Michael R.; Skovronsky, Daniel; Kung, Hank F.

    2011-01-01

    β-amyloid plaques (Aβ plaques) in the brain, containing predominantly fibrillary Aβ peptide aggregates, represent a defining pathologic feature of Alzheimer disease (AD). Imaging agents targeting the Aβ plaques in the living human brain are potentially valuable as biomarkers of pathogenesis processes in AD. (E)-4-(2-(6-(2-(2-(2-18F-fluoroethoxy)ethoxy)ethoxy)pyridin-3-yl)vinyl)-N-methyl benzenamine (18F-AV-45) is such as an agent currently in phase III clinical studies for PET of Aβ plaques in the brain. Methods In vitro binding of 18F-AV-45 to Aβ plaques in the postmortem AD brain tissue was evaluated by in vitro binding assay and autoradiography. In vivo biodistribution of 18F-AV-45 in mice and ex vivo autoradiography of AD transgenic mice (APPswe/PSEN1) with Aβ aggregates in the brain were performed. Small-animal PET of a monkey brain after an intravenous injection of 18F-AV-45 was evaluated. Results 18F-AV-45 displayed a high binding affinity and specificity to Aβ plaques (Kd, 3.72 ± 0.30 nM). In vitro autoradiography of postmortem human brain sections showed substantial plaque labeling in AD brains and not in the control brains. Initial high brain uptake and rapid washout from the brain of healthy mice and monkey were observed. Metabolites produced in the blood of healthy mice after an intravenous injection were identified. 18F-AV-45 displayed excellent binding affinity to Aβ plaques in the AD brain by ex vivo autoradiography in transgenic AD model mice. The results lend support that 18F-AV-45 may be a useful PET agent for detecting Aβ plaques in the living human brain. PMID:19837759

  3. Energy Partition During In-plane Dynamic Rupture on a Frictional Interface

    NASA Astrophysics Data System (ADS)

    Needleman, A.; Shi, Z.; Ben-Zion, Y.

    2007-12-01

    We study properties of dynamic ruptures and the partition of energy between radiation and dissipative mechanisms using two-dimensional in-plane calculations with the finite element method. The model consists of two identical isotropic elastic media separated by an interface governed by rate- and state-dependent friction. Rupture is initiated by gradually overstressing a localized nucleation zone. Our simulations with model parameters representative of Homalite-100 indicate that different values of parameters controlling the velocity dependence of friction, the strength excess parameter and the length of the nucleation zone, can lead to the following four rupture modes: supershear crack-like rupture, subshear crack-like rupture, subshear single pulse and supershear train of pulses. High initial shear stress and weak velocity dependence of friction favor crack-like ruptures, while the opposite conditions favor the pulse mode. The rupture mode can switch from a subshear single pulse to a supershear train of pulses when the width of the nucleation zone increases. The elastic strain energy released over the same propagation distance by the different rupture modes has the following order: supershear crack, subshear crack, supershear train of pulses and subshear single pulse. The same order applies also to the ratio of kinetic energy (radiation) to total change of elastic energy for the different rupture modes. Decreasing the dynamic coefficient of friction increases the fraction of stored energy that is converted to kinetic energy. In the current study we use model parameters representative of rocks instead of Homalite-100, by modeling recent results of Kilgore et al. (2007) who measured and estimated various energy components in laboratory friction experiments with granite. We are also incorporating into the code ingredients that will allow us to study rupture properties and energy partition for cases with a bimaterial interface and dynamic generation of plastic strain

  4. Risk Factors for Aneurysm Rupture in Patients Kept Under Ultrasound Surveillance

    PubMed Central

    Brown, Louise C.; Powell, Janet T.

    1999-01-01

    Objective To investigate risk factors associated with aneurysm rupture using patients randomized into the U.K. Small Aneurysm Trial (n = 1090) or monitored for aneurysm growth in the associated study (n = 1167). Summary Background Data The U.K. Small Aneurysm Trial has shown that ultrasound surveillance is a safe management option for patients with small abdominal aortic aneurysms (4.0 to 5.5 cm in diameter), with an annual rupture rate of 1%. Methods In the cohort of 2257 patients (79% male), aged 59 to 77 years, 103 instances of abdominal aortic aneurysm rupture were identified during the 7-year period of follow-up (1991–1998). Almost all patients (98%) had initial aneurysm diameters in the range of 3 to 6 cm, and the majority of ruptures (76%) occurred in patients with aneurysms ≥5 cm in diameter. Kaplan-Meier survival and Cox regression analysis were used to identify baseline risk factors associated with aneurysm rupture. Results After 3 years, the annual rate of aneurysm rupture was 2.2% (95% confidence interval 1.7 to 2.8). The risk of rupture was independently and significantly associated with female sex (p < 0.001), larger initial aneurysm diameter (p < 0.001), lower FEV1 (p = 0.004), current smoking (p = 0.01), and higher mean blood pressure (p = 0.01). Age, body mass index, serum cholesterol concentration, and ankle/brachial pressure index were not associated with an increased risk of aneurysm rupture. Conclusions Within this cohort of patients, women had a threefold higher risk of aneurysm rupture than men. Effective control of blood pressure and cessation of smoking are likely to diminish the risk of rupture. PMID:10493476

  5. Induced rupture of vesicles adsorbed on glass by pore formation at the surface-bilayer interface.

    PubMed

    Kataoka-Hamai, Chiho; Yamazaki, Tomohiko

    2015-02-03

    Supported lipid bilayers (SLBs) are often formed by spontaneous vesicle rupture and fusion on a solid surface. A well-characterized rupture mechanism for isolated vesicles is pore nucleation and expansion in the solution-exposed nonadsorbed area. In contrast, pore formation in the adsorbed bilayer region has not been investigated to date. In this work, we studied the detailed mechanisms of asymmetric rupture of giant unilamellar vesicles (GUVs) adsorbed on glass using fluorescence microscopy. Asymmetric rupture is the pathway where a rupture pore forms in a GUV near the edge of the glass-bilayer interface with high curvature and then expansion of the pore yields a planar bilayer patch. We show that asymmetric rupture occasionally resulted in SLB patches bearing a defect pore. The defect formation probability depended on lipid composition, salt concentration, and pH. Approximately 40% of negatively charged GUVs under physiological conditions formed pore-containing SLB patches, while negatively charged GUVs at low salt concentration or pH 4.0 and positively charged GUVs exhibited a low probability of defect inclusion. The edge of the defect pore was either in contact with (on-edge) or away from (off-edge) the edge of the planar bilayer. On-edge pores were predominantly formed over off-edge defects. Pores initially formed in the glass-adsorbed region before rupture, most frequently in close contact with the edge of the adsorbed region. When a pore formed near the edge of the adsorbed area or when the edge of a pore reached that of the adsorbed area by pore expansion, asymmetric rupture was induced from the defect site. These induced rupture mechanisms yielded SLB patches with an on-edge pore. In contrast, off-edge pores were produced when defect pore generation and subsequent vesicle rupture were uncoupled. The current results demonstrate that pore formation in the surface-adsorbed region of GUVs is not a negligible event.

  6. Noninvasive diagnosis of vulnerable coronary plaque

    PubMed Central

    Pozo, Eduardo; Agudo-Quilez, Pilar; Rojas-González, Antonio; Alvarado, Teresa; Olivera, María José; Jiménez-Borreguero, Luis Jesús; Alfonso, Fernando

    2016-01-01

    Myocardial infarction and sudden cardiac death are frequently the first manifestation of coronary artery disease. For this reason, screening of asymptomatic coronary atherosclerosis has become an attractive field of research in cardiovascular medicine. Necropsy studies have described histopathological changes associated with the development of acute coronary events. In this regard, thin-cap fibroatheroma has been identified as the main vulnerable coronary plaque feature. Hence, many imaging techniques, such as coronary computed tomography, cardiac magnetic resonance or positron emission tomography, have tried to detect noninvasively these histomorphological characteristics with different approaches. In this article, we review the role of these diagnostic tools in the detection of vulnerable coronary plaque with particular interest in their advantages and limitations as well as the clinical implications of the derived findings. PMID:27721935

  7. Plaque formation of dietary isomaltulose in humans.

    PubMed

    Ooshima, T; Izumitani, A; Takei, T; Fujiwara, T; Sobue, S

    1990-01-01

    The plaque formation of isomaltulose, a sucrose isomer, was examined in 15 human volunteers with both diet and oral hygiene under supervision. The subjects were requested to refrain from all oral hygiene procedures for 3 days and were provided between-meal snacks containing 157 g of 4 test sugars (100% isomaltulose, 70% isomaltulose + 30% sucrose, 50% isomaltulose + 50% sucrose, and 100% sucrose). The study was repeated 4 times over 4 weeks. The isomaltulose diet resulted in the lowest plaque index, while sucrose induced a significantly greater deposition. In the absence of sucrose-containing snacks, mutans streptococci in saliva decreased below the baseline level. These results suggest that isomaltulose may be a suitable substitute for sucrose in between meal snacks.

  8. Enucleation versus plaque irradiation for choroidal melanoma

    SciTech Connect

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

    1988-07-01

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

  9. Plaque accumulations caused by interdental stripping.

    PubMed

    Radlanski, R J; Jäger, A; Schwestka, R; Bertzbach, F

    1988-11-01

    Human enamel surfaces were stripped with orthodontic grinding and finishing materials, and evaluated with the scanning electron microscope (SEM). Even under in vitro conditions with the finest finishing strips, it was not possible to produce an enamel surface free of the furrows that result from the initial abrasion caused by the coarse strip. Enamel surfaces stripped gradually from coarse to superfine were left in the mouths of patients for 12 weeks and evaluated with the SEM. The edges of the furrows were found to be smoother but the furrows remained wide and deep enough to facilitate more plaque accumulations than those on untreated surfaces. The use of dental floss did not result in prevention of plaque accumulations along the bottom of the furrows.

  10. Reliability and discriminatory power of methods for dental plaque quantification

    PubMed Central

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

    2010-01-01

    Objective This in situ study evaluated the discriminatory power and reliability of methods of dental plaque quantification and the relationship between visual indices (VI) and fluorescence camera (FC) to detect plaque. Material and Methods Six volunteers used palatal appliances with six bovine enamel blocks presenting different stages of plaque accumulation. The presence of plaque with and without disclosing was assessed using VI. Images were obtained with FC and digital camera in both conditions. The area covered by plaque was assessed. Examinations were done by two independent examiners. Data were analyzed by Kruskal-Wallis and Kappa tests to compare different conditions of samples and to assess the inter-examiner reproducibility. Results Some methods presented adequate reproducibility. The Turesky index and the assessment of area covered by disclosed plaque in the FC images presented the highest discriminatory powers. Conclusions The Turesky index and images with FC with disclosing present good reliability and discriminatory power in quantifying dental plaque. PMID:20485931

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

    precise lesion formation in the presence or arterial pulsation and tissue motion. In this paper, we show results from targeting both proximal and distal sides of the vessel wall with a series of 5 - 7 discrete shots in each plane (typically three planes per plaque). Experiments to demonstrate a full treatment forming contiguous lesion within the target plaque are currently underway.

  12. Rare Case of Multiple Aneurysms with Rupture of the Deep Femoral Artery Aneurysm.

    PubMed

    Dulić, Grgur; Požgain, Zrinka; Pinotić, Krešimir; Šego, Krunoslav; Selthofer, Robert; Rončević, Ivica

    2015-11-01

    Profunda femoris artery aneurysms (PFAA) are very rare and easily overlooked. Currently, around 100 PFAA and 20 ruptured PFAA have been described in the literature. This is a report on a case of ruptured PFAA with thoracoabdominal aortic aneurysm. A ligation of the profunda femoris artery (PFA) and a femoropopliteal supragenicular bypass with vascular prosthesis were performed in the surgical treatment, which showed good results on the further follow-ups. A month after the procedure the patient had a rupture of the thoracoabdominal aortic aneurysm with fatal result. Therefore, it is recommended to perform a search for another aneurysm, especially on the aortoiliac segment, in every diagnosed PFAA case.

  13. Low TLR7 gene expression in atherosclerotic plaques is associated with major adverse cardio- and cerebrovascular events

    PubMed Central

    Karadimou, Glykeria; Folkersen, Lasse; Berg, Martin; Perisic, Ljubica; Discacciati, Andrea; Roy, Joy; Hansson, Göran K.; Persson, Jonas; Paulsson-Berne, Gabrielle

    2017-01-01

    Aims Processes in the development of atherosclerotic lesions can lead to plaque rupture or erosion, which can in turn elicit myocardial infarction or ischaemic stroke. The aims of this study were to determine whether Toll-like receptor 7 (TLR7) gene expression levels influence patient outcome and to explore the mechanisms linked to TLR7 expression in atherosclerosis. Methods and results Atherosclerotic plaques were removed by carotid endarterectomy (CEA) and subjected to gene array expression analysis (n = 123). Increased levels of TLR7 transcript in the plaques were associated with better outcome in a follow-up study over a maximum of 8 years. Patients with higher TLR7 transcript levels had a lower risk of experiencing major cardiovascular and cerebrovascular events (MACCE) during the follow-up period after CEA (hazard ratio: 2.38, P = 0.012, 95% CI 1.21–4.67). TLR7 was expressed in all plaques by T cells, macrophages and endothelial cells in capillaries, as shown by immunohistochemistry. In short-term tissue cultures, ex vivo treatment of plaques with the TLR7 ligand imiquimod elicited dose-dependent secretion of IL-10, TNF-α, GM-CSF, and IL-12/IL-23p40. This secretion was blocked with a TLR7 inhibitor. Immunofluorescent tissue analysis after TLR7 stimulation showed IL-10 expression in T cells, macrophages and vascular smooth muscle cells. TLR7 mRNA levels in the plaques were correlated with IL-10 receptor (r = 0.4031, P < 0.0001) and GM-CSF receptor A (r = 0.4354, P < 0.0001) transcripts. Conclusion These findings demonstrate that TLR7 is abundantly expressed in human atherosclerotic plaques. TLR7 ligation elicits the secretion of pro-inflammatory and anti-inflammatory cytokines, and high TLR7 expression in plaques is associated with better patient outcome, suggesting that TLR7 is a potential therapeutic target for prevention of complications of atherosclerosis. PMID:27864310

  14. Quantification of plaque stiffness by Brillouin microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Antonacci, Giuseppe; Pedrigi, Ryan; Krams, Rob; Török, Peter

    2016-03-01

    Spontaneous Brillouin scattering is an inelastic scattering process arising from inherent thermal density fluctuations, or acoustic phonons, propagating in a medium. Over the last few years, Brillouin spectroscopy has shown great potential to become a reliable non-invasive diagnostic tool due to its unique capability of retrieving viscoelastic properties of materials such as strain and stiffness. The detection of the weak scattered light, in addition to the resolution of the Brillouin peaks (typically shifted by few GHz from the central peak) represent one of the greatest challenges in Brillouin. The recent development of high sensitivity CCD cameras has brought Brillouin spectroscopy from a point sampling technique to a new imaging modality. Furthermore, the application of Virtually Imaged Phased Array (VIPA) etalons has dramatically reduced insertion loss simultaneously allowing fast (<1s) collection of the entire spectrum. Hitherto Brillouin microscopy has been shown the ability to provide unique stiffness maps of biological samples, such as the human lens, in a non-destructive manner. In this work, we present results obtained using our Brillouin microscope to map the stiffness variations in the walls of blood vessels in particular when atherosclerotic plaques are formed. The stiffness of the membrane that covers the plaques is critical in developing acute myocardial infarction yet it is not currently possible to credibly assess its stiffness due to lack of suitable methods.

  15. Cataractogenesis after Cobalt-60 eye plaque radiotherapy

    SciTech Connect

    Kleineidam, M.; Augsburger, J.J. ); Hernandez, C.; Glennon, P.; Brady, L.W. )

    1993-07-15

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

  16. Retroperitoneal liposarcoma associated with small plaque parapsoriasis

    PubMed Central

    Tartaglia, Francesco; Blasi, Sara; Sgueglia, Monica; Polichetti, Paolo; Tromba, Luciana; Berni, Alberto

    2007-01-01

    Background Extremely rare cases of paraneoplastic syndromes or ectopic production of proteins associated with liposarcoma are reported in literature. Production of Granulocyte-Colony Stimulating Factor, alpha-fetoprotein, paraneoplastic pemphigus and leucocytosis, Acrokeratosis paraneoplastica (Bazex's syndrome) are reported. The present report describes a case of retroperitoneal liposarcoma associated with small plaque parapsoriasis. Our search in the English literature of such a kind of association did not reveal any case reported. Case presentation A 74 year male patient was admitted to our hospital because of the presence of an abdominal mass in right iliac fossa. He also complained of a two-year history of psoriasiform eruptions. The CT scan showed a retroperitoneal pelvic mass. Therefore surgical resection of the tumor was performed. After surgery, the skin eruptions disappeared completely in seven days and so a diagnosis of parapsoriasis syndrome was done. Conclusion Parallel disappearing of skin eruptions after surgery, typical clinical picture and not specific histology of the cutaneous lesions suggest the diagnosis of small plaque parapsoriasis. Therefore we propose to add Small Plaque Parapsoriasis to the list of paraneoplastic syndromes associated to liposarcoma. PMID:17620118

  17. Microwave plaque thermoradiotherapy for choroidal melanoma.

    PubMed Central

    Finger, P. T.

    1992-01-01

    Microwave thermoradiotherapy was used as a primary treatment for 44 patients with choroidal melanoma. An episcleral dish-shaped microwave antenna was placed beneath the tumour at the time of plaque brachytherapy. While temperatures were measured at the sclera, the tumour's apex was targeted to receive a minimum of 42 degrees C for 45 minutes. In addition, the patients received full or reduced doses of plaque radiotherapy. No patients have been lost to follow-up. Two eyes have been enucleated: one for rubeotic glaucoma, and one for uveitic glaucoma. Though six patients have died, only one death was due to metastatic choroidal melanoma (39 months after treatment). Clinical observations suggest that the addition of microwave heating to plaque radiation therapy of choroidal melanoma has been well tolerated. There has been a 97.7% local control rate (with a mean follow-up of 22.2 months). We have reduced the minimum tumour radiation dose (apex dose) to levels used for thermoradiotherapy of cutaneous melanomas (50 Gy/5000 rad). Within the range of this follow-up period no adverse effects which might preclude the use of this microwave heat delivery system for treatment of choroidal melanoma have been noted. Images PMID:1622949

  18. Cellular immune response in multiple sclerosis plaques.

    PubMed Central

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

    1990-01-01

    Multiple sclerosis plaques were immunohistochemically stained to exhibit cells expressing immune-system antigens. Human leukocyte antigen (HLA)-DR-positive cells formed dense rings around all plaque regions. The majority were reactive microglia/macrophages. Counterstaining with oil red O revealed heavy myelin debris within these cells. They were distinct from astrocytes, which were identified with an antibody to glial fibrillary acidic protein (GFAP) and which did not contain oil red O myelin debris. Numerous leukocytes and microglia were stained with antibody to leukocyte common antigen (LCA). Lymphocytes in cuffs around vessels, along the margins of capillary walls, and, sparingly, in the tissue matrix of affected areas, were stained with antibodies to CD4 (T-helper/inducer) and CD8 (T-cytotoxic/suppressor). In experimental allergic encephalomyelitis (EAE) induced in Lewis rats, a similar proliferation of Ia-positive (OX6, OX17) cells displaying reactive microglia/macrophage morphology was observed. These Ia-positive cells also were easily distinguished from GFAP-positive astrocytes. The results suggest that macrophages/reactive microglia, and not astrocytes, express class II MHC antigens in multiple sclerosis and EAE plaques. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:1698025

  19. Curcumin Targeted, Polymalic Acid-Based MRI Contrast Agent for the Detection of Aβ Plaques in Alzheimer's Disease.

    PubMed

    Patil, Rameshwar; Gangalum, Pallavi R; Wagner, Shawn; Portilla-Arias, Jose; Ding, Hui; Rekechenetskiy, Arthur; Konda, Bindu; Inoue, Satoshi; Black, Keith L; Ljubimova, Julia Y; Holler, Eggehard

    2015-09-01

    Currently, there is no gadolinium-based contrast agent available for conventional magnetic resonance imaging (MRI) detection of amyloidal beta (Aβ) plaques in Alzheimer's disease (AD). Its timely finding would be vital for patient survival and quality of life. Curcumin (CUR), a common Indian spice effectively binds to Aβ plaques which is a hallmark of AD. To address this binding, we have designed a novel nanoimaging agent (NIA) based on nature-derived poly(β-l-malic acid) (PMLA) containing covalently attached gadolinium-DOTA(Gd-DOTA) and nature-derived CUR. The all-in-one agent recognizes and selectively binds to Aβ plaques and is detected by MRI. It efficiently detected Aβ plaques in human and mouse samples by an ex vivo staining. The method can be useful in clinic for safe and noninvasive diagnosis of AD.

  20. Spontaneous diaphragm rupture associated with vaginal delivery.

    PubMed

    Hamaji, Masatsugu; Burt, Bryan M; Ali, Syed Osman; Cohen, Daniel M

    2013-08-01

    Spontaneous rupture of the diaphragm associated with vaginal delivery is a rare occurrence, but has high rates of morbidity and mortality. Herein, we present a first uncomplicated case of spontaneous rupture of the diaphragm associated with vaginal delivery, which was treated successfully with surgery via a thoracotomy.

  1. Uterine rupture. A seat belt hazard.

    PubMed

    van Enk, A; van Zwam, W

    1994-05-01

    A case is described of a uterine rupture resulting from a car accident occurring in a woman who was wearing a seat belt as generally recommended. The rupture was initially not recognised and only became apparent after attempts to induce labor which led to expulsion of the fetus into the abdominal cavity.

  2. Fractal avalanche ruptures in biological membranes

    NASA Astrophysics Data System (ADS)

    Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

    2010-11-01

    Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

  3. Urgent arterial embolization of ruptured renal angiomyolipoma

    PubMed Central

    Yilmaz, Feyza

    2015-01-01

    The most undesired complication of renal angiomyolipoma (AML) is bleeding. Because of tumor rupture, the bleeding can spread to the retroperitoneal field and can be severe enough to be life threatening. We report a case of retroperitoneal hemorrhage caused by a ruptured AML that was successfully treated with transarterial embolization with N-butyl cyanoacrylate. PMID:28352700

  4. Do buried-rupture earthquakes trigger less landslides than surface-rupture earthquakes for reverse faults?

    NASA Astrophysics Data System (ADS)

    Xu, Chong

    2014-07-01

    Gorum et al. (2013, Geomorphology 184, 127-138) carried out a study on inventory compilation and statistical analyses of landslides triggered by the 2010 Mw 7.0 Haiti earthquake. They revealed that spatial distribution patterns of these landslides were mainly controlled by complex rupture mechanism and topography. They also suggested that blind-rupture earthquakes trigger fewer landslides than surface-rupture earthquakes on thrust reverse faults. Although a few lines of evidence indicate that buried-rupture earthquakes might trigger fewer landslides than surface-rupture earthquakes on reverse faults, more careful comparisons and analyses indicate that it is not always true. Instead, some cases show that a buried-rupture earthquake can trigger a larger quantity of landslides that are distributed in a larger area, whereas surface-rupture earthquakes can trigger larger but a fewer landslides distributed in a smaller area.

  5. Monoglyceride lipase deficiency modulates endocannabinoid signaling and improves plaque stability in ApoE-knockout mice

    PubMed Central

    Vujic, Nemanja; Schlager, Stefanie; Eichmann, Thomas O.; Madreiter-Sokolowski, Corina T.; Goeritzer, Madeleine; Rainer, Silvia; Schauer, Silvia; Rosenberger, Angelika; Woelfler, Albert; Doddapattar, Prakash; Zimmermann, Robert; Hoefler, Gerald; Lass, Achim; Graier, Wolfgang F.; Radovic, Branislav; Kratky, Dagmar

    2016-01-01

    plaque rupture. PMID:26584135

  6. Bacteriology of Human Experimental Gingivitis: Effect of Plaque Age

    PubMed Central

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

    1978-01-01

    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

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

    SciTech Connect

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

    1990-06-01

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

  8. Amniopatch for iatrogenic rupture of the fetal membranes.

    PubMed

    Deprest, Jan; Emonds, Marie-Paule; Richter, Jute; DeKoninck, Philip; Van Mieghem, Tim; Van Schoubroeck, Dominique; Devlieger, Roland; De Catte, Luc; Lewi, Liesbeth

    2011-07-01

    With the increased use of invasive fetal procedures, the number of women facing post-procedure membrane rupture is increasing. Here we review the use of platelets and fresh frozen plasma for sealing iatrogenic fetal membrane defects by describing the mechanisms of action of the amniopatch procedure as well as published experience. In cases of iatrogenic preterm pre-labour rupture of the membranes, amniopatch effectively seals the fetal membranes in over two-thirds of cases. There is a risk of 16% of in utero fetal death, which may occur at varying intervals from the procedure and often for unknown reasons. Amniopatch has also been used as a treatment of chorionic membrane separation. In summary, current experience suggests that in cases of early onset but persistent amniotic fluid leakage following an invasive fetal procedure, amniopatch is an option.

  9. Injuries to the finger flexor pulley system in rock climbers: current concepts.

    PubMed

    Schöffl, Volker Rainer; Schöffl, Isabelle

    2006-04-01

    Closed traumatic ruptures of finger flexor tendon pulleys began to be recognized specifically over the past several decades. This injury, although rare in the general population, is seen more commonly in rock climbers. This article analyzes this type of injury and the current diagnostic and therapeutic criteria. Ultrasound and magnetic resonance imaging are used to differentiate between a pulley strain, partial rupture, complete rupture, or multiple ruptures. Grade I to III injuries (strains, partial rupture, single ruptures) are treated conservatively with initial immobilization and early functional therapy under pulley protection. Grade IV injuries (multiple ruptures) require surgical repair.

  10. Intersonic shear cracks and fault ruptures

    NASA Astrophysics Data System (ADS)

    Rosakis, Ares J.

    2002-06-01

    Recent experimental observations of intersonic shear rupture events that occur in a variety of material systems have rekindled interest in the intersonic failure phenomenon. Since the early 1990s, engineers and scientists working in all length scales, from the atomistic, the structural, all the way up to the scale of the earth's deformation processes, have undertaken joint efforts to study this unexplored area of fracture mechanics. The analysis in the present article emphasizes the cooperative and complementary manner in which experimental observations and analytical and numerical developments have proceeded. The article first reviews early contributions to the theoretical literature of dynamic subsonic and intersonic fracture and highlights the significant differences between tensile and shear cracks. The article then uses direct laboratory observations as a framework for discussing the physics of intersonic shear rupture occurring in constitutively homogeneous (isotropic and anisotropic) as well as in inhomogeneous systems, all containing preferable crack paths or faults. Experiments, models, and field evidence at a variety of length scales (from the atomistic, the continuum, and up to the scale of geological ruptures) are used to discuss processes such as (1) shock wave formation, (2) large-scale frictional contact and sliding at the rupture faces, and (3) maximum attainable rupture speeds and rupture speed stability. Particular emphasis is given to geophysical field evidence and to the exploration of the possibility of intersonic fault rupture during shallow crustal earthquake events.

  11. Extraneural rupture of intraneural ganglion cysts.

    PubMed

    Shahid, Kameron R; Hébert-Blouin, Marie-Noëlle; Amrami, Kimberly K; Spinner, Robert J

    2011-01-01

    Rupture of simple (extraneural) cysts such as popliteal cysts (Baker's cysts) is a well-known occurrence. The purpose of this report is to introduce the similar occurrence of extraneural rupture of peroneal and tibial intraneural cysts in the knee region, describe the associated magnetic resonance imaging (MRI) findings, and identify risk factors. There was MRI evidence of rupture in 20 of 38 intraneural cases reviewed, mainly in the region of the fibular head and popliteal fossa. Ruptured intraneural cysts and simple cysts share these MRI findings: T2 hyperintense fluid within surrounding intermuscular fascial planes and enhancement with intravenous contrast consistent with inflammation. The mean maximal diameter of the ruptured intraneural cysts was statistically significantly smaller than that of the unruptured cysts. The authors believe that extraneural rupture of an intraneural cyst is due to increased intraarticular pressures transmitted within the cyst and/or elevated extrinsic pressure delivered to the cyst, such as by trauma, akin to the etiology of rupture of extraneural ganglion cysts.

  12. Metrics for comparing dynamic earthquake rupture simulations

    USGS Publications Warehouse

    Barall, Michael; Harris, Ruth A.

    2014-01-01

    Earthquakes are complex events that involve a myriad of interactions among multiple geologic features and processes. One of the tools that is available to assist with their study is computer simulation, particularly dynamic rupture simulation. A dynamic rupture simulation is a numerical model of the physical processes that occur during an earthquake. Starting with the fault geometry, friction constitutive law, initial stress conditions, and assumptions about the condition and response of the near‐fault rocks, a dynamic earthquake rupture simulation calculates the evolution of fault slip and stress over time as part of the elastodynamic numerical solution (Ⓔ see the simulation description in the electronic supplement to this article). The complexity of the computations in a dynamic rupture simulation make it challenging to verify that the computer code is operating as intended, because there are no exact analytic solutions against which these codes’ results can be directly compared. One approach for checking if dynamic rupture computer codes are working satisfactorily is to compare each code’s results with the results of other dynamic rupture codes running the same earthquake simulation benchmark. To perform such a comparison consistently, it is necessary to have quantitative metrics. In this paper, we present a new method for quantitatively comparing the results of dynamic earthquake rupture computer simulation codes.

  13. Intradural Extramedullary Tuberculoma Mimicking En Plaque Meningioma

    PubMed Central

    Shim, Dae Moo; Kim, Tae Kyun; Chae, Soo Uk

    2010-01-01

    A 24-year-old man with tuberculosis meningitis developed acute paraplegia and sensory disturbances 5 weeks after receiving conventional antituberculous therapy. Magnetic resonance imaging revealed an intradural extramedullary long segmental mass mimicking en plaque meningioma at the T2-T6 vertebrae levels. Prompt surgical decompression was performed. A histology examination of the mass revealed a tuberculoma. After surgery, the patient showed improved motor power and a normal bladder function. Intradural extramedullary tuberculoma of the spinal cord is rare complication of tuberculosis meningitis, which can occur as a response to conventional antituberculous therapy. PMID:21119945

  14. Fibrous Pleural Plaques Detected at Autopsy

    PubMed Central

    TÜRKMEN, Nursel; EREN, Bülent; GÜNDOĞMUŞ, Ümit Naci

    2014-01-01

    The reported case was a 84-year-old male, dead after a traffic accident. The death was considered to be suspicious by prosecutor and an autopsy was mandated. In macroscopic autopsy investigation left tibia, fibula and multiple rib fractures, widespread seborrheic keratoses, and hyperpigmented skin lesions were detected. In the left chest cavity blood content and white colored lesions spread on the left parietal pleura and chest surface of the thoracic diaphragm were observed. The histological examination of the pleural lesions revealed fibrotic hyalinized structures with calcified foci. Investigation of pleural plaques in forensic autopsy is important for scientific classification of this interesting entity. PMID:25705312

  15. Plaques Formed by Mutagenized Viral Populations Have Elevated Coinfection Frequencies

    PubMed Central

    Aguilera, Elizabeth R.; Erickson, Andrea K.; Jesudhasan, Palmy R.; Robinson, Christopher M.

    2017-01-01

    ABSTRACT The plaque assay is a common technique used to measure virus concentrations and is based upon the principle that each plaque represents a single infectious unit. As such, the number of plaques is expected to correlate linearly with the virus dilution plated, and each plaque should be formed by a single founder virus. Here, we examined whether more than one virus can contribute to plaque formation. By using genetic and phenotypic assays with genetically marked polioviruses, we found that multiple parental viruses are present in 5 to 7% of plaques, even at an extremely low multiplicity of infection. We demonstrated through visual and biophysical assays that, like many viral stocks, our viral stocks contain both single particles and aggregates. These data suggest that aggregated virions are capable of inducing coinfection and chimeric plaque formation. In fact, inducing virion aggregation via exposure to low pH increased coinfection in a flow cytometry-based assay. We hypothesized that plaques generated by viruses with high mutation loads may have higher coinfection frequencies due to processes restoring fitness, such as complementation and recombination. Indeed, we found that coinfection frequency correlated with mutation load, with 17% chimeric plaque formation for heavily mutagenized viruses. Importantly, the frequency of chimeric plaques may be underestimated by up to threefold, since coinfection with the same parental virus cannot be scored in our assay. This work indicates that more than one virus can contribute to plaque formation and that coinfection may assist plaque formation in situations where the amount of genome damage is high. PMID:28292984

  16. Dosimetric Benefit of a New Ophthalmic Radiation Plaque

    SciTech Connect

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

    2012-12-01

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

  17. Extracellular matrix content of ruptured anterior cruciate ligament tissue.

    PubMed

    Young, Kate; Samiric, Tom; Feller, Julian; Cook, Jill

    2011-08-01

    Anterior cruciate ligaments (ACLs) can rupture with simple movements, suggesting that structural changes in the ligament may reduce the loading capacity of the ligament. We aimed to investigate if proteoglycan and collagen levels were different between ruptured and non-ruptured ACLs. We also compared changes in ruptured tissue over time. During arthroscopic knee reconstruction surgery 24 ruptured ACLs were collected from participants (10 females; 14 males; mean age 24 years). Four non-ruptured ACLs were obtained from participants undergoing total knee replacement surgery (one female, three males; mean age 66 years). Western blot analysis was used to characterise core proteins of aggrecan, versican, decorin and biglycan and glycosaminoglycan assays were also conducted. Collagen levels were measured by hydroxyproline (OHPr) assays. Significantly lower levels of collagen, were found in ruptured ACL compared to non-ruptured ACL (p=0.004). Lower levels of both small and large proteoglycans were found in ruptured than non-ruptured ACLs. No correlation was found between time since rupture and proteoglycan or collagen levels. Ruptured ACLs had less collagen and proteoglycans than non-ruptured ACLs. These changes indicate either extracellular matrix protein levels were reduced prior to rupture or levels decreased immediately after rupture. It is possible that the composition and structure of ACLs that rupture are different to normal ACLs, potentially reducing the tissue's ability to withstand loading. An enhanced understanding of the aetiology of ACL injury could help identify individuals who may be predisposed to rupture.

  18. Ruptured urinary bladder in a heifer.

    PubMed

    Roussel, A J; Ward, D S

    1985-06-15

    A yearling Holstein heifer was admitted with abdominal pain and bilateral, ventral abdominal distention. Bladder rupture was diagnosed by abdominocentesis and endoscopy. Correction of metabolic derangements was accomplished by volume diuresis, with maintenance of a urethral catheter before surgical repair of the bladder. The cause of the bladder rupture was believed to be related to adhesions resulting from previous surgery for urachal abscessation. Bladder rupture, which usually occurs in bulls or steers secondary to urolithiasis or in cows after dystocia, also should be considered in prepartum heifers with dehydration, abdominal pain, and abdominal distention.

  19. Plantar fascia rupture: diagnosis and treatment.

    PubMed

    Rolf, C; Guntner, P; Ericsäter, J; Turan, I

    1997-01-01

    Two patients with spontaneous medial plantar fascia rupture due to a definite injury with no prior symptoms, were referred to our institution. Clinically, there was a tender lump in the sole, and magnetic resonance imaging confirmed the diagnosis. Nonoperative treatment was sufficient in curing the acute total rupture. Endoscopic release was used on the partially ruptured plantar fascia, but it is probably more optimal in the acute phase. The literature provides no comparative data on operative or nonoperative treatment efficacy for this rare condition.

  20. History of surgery for ruptured disk.

    PubMed

    Patwardhan, R V; Hadley, M N

    2001-01-01

    The history of surgery for ruptured disk of the human spine began approximately a century ago. Advances in the understanding of symptoms and signs of root or cord compression, their relationship to the pathology, and the refinement in imaging techniques have contributed to the present surgical management of rupture disk disease. Historical findings relevant to the cervical, thoracic, and lumbosacral regions of the spine, with relevant pathophysiology, imaging, and surgical treatment, including the evolution of various surgical approaches are discussed. Surgeons and other contributors in the medical field are cited for their respective contributions to the evolution of the present operative approaches for disk ruptures in the cervical, thoracic, and lumbar spinal regions.

  1. Gastric rupture after the Heimlich maneuver.

    PubMed

    Bintz, M; Cogbill, T H

    1996-01-01

    Since 1975, the Heimlich maneuver has been widely applied to relieve upper airway obstruction caused by aspirated material. Life-threatening complications have been documented following this simple procedure. We report two cases of gastric rupture after use of the Heimlich maneuver. Both patients experienced pulmonary and abdominal symptoms. The diagnosis was confirmed in each case by the demonstration of free intraperitoneal air on an upright chest roentgenogram. Full-thickness gastric rupture along the lesser curvature of the stomach was repaired in both patients; one patient died. Abdominal pain or persistent abdominal distention despite nasogastric suction after the Heimlich maneuver should prompt evaluation for possible gastric rupture.

  2. Subsurface ablation of atherosclerotic plaque using ultrafast laser pulses

    PubMed Central

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

    2015-01-01

    We perform subsurface ablation of atherosclerotic plaque using ultrafast pulses. Excised mouse aortas containing atherosclerotic plaque were ablated with ultrafast near-infrared (NIR) laser pulses. Optical coherence tomography (OCT) was used to observe the ablation result, while the physical damage was inspected in histological sections. We characterize the effects of incident pulse energy on surface damage, ablation hole size, and filament propagation. We find that it is possible to ablate plaque just below the surface without causing surface damage, which motivates further investigation of ultrafast ablation for subsurface atherosclerotic plaque removal. PMID:26203381

  3. DETAIL OF PLAQUE DESCRIBING LION SCULPTURES BY ROLAND HINTON PERRY, ...

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

    DETAIL OF PLAQUE DESCRIBING LION SCULPTURES BY ROLAND HINTON PERRY, NORTHWEST ABUTMENT - Connecticut Avenue Bridge, Spans Rock Creek & Potomac Parkway at Connecticut Avenue, Washington, District of Columbia, DC

  4. Subsurface ablation of atherosclerotic plaque using ultrafast laser pulses.

    PubMed

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

    2015-07-01

    We perform subsurface ablation of atherosclerotic plaque using ultrafast pulses. Excised mouse aortas containing atherosclerotic plaque were ablated with ultrafast near-infrared (NIR) laser pulses. Optical coherence tomography (OCT) was used to observe the ablation result, while the physical damage was inspected in histological sections. We characterize the effects of incident pulse energy on surface damage, ablation hole size, and filament propagation. We find that it is possible to ablate plaque just below the surface without causing surface damage, which motivates further investigation of ultrafast ablation for subsurface atherosclerotic plaque removal.

  5. 25. DETAIL VIEW OF COMMEMORATIVE NAMEPLATE PLAQUE, NORTH END SPAN ...

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

    25. DETAIL VIEW OF COMMEMORATIVE NAMEPLATE PLAQUE, NORTH END SPAN - East Bloomsburg Bridge, Spanning Susquehanna River at Pennsylvania Route 487 (Legislative Route 283), Bloomsburg, Columbia County, PA

  6. 14. DETAIL VIEW OF COMMEMORATIVE PLAQUE AND FINIAL, NORTH END ...

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

    14. DETAIL VIEW OF COMMEMORATIVE PLAQUE AND FINIAL, NORTH END SPAN - East Bloomsburg Bridge, Spanning Susquehanna River at Pennsylvania Route 487 (Legislative Route 283), Bloomsburg, Columbia County, PA

  7. Expression of NPP1 is regulated during atheromatous plaque calcification

    PubMed Central

    Nitschke, Yvonne; Hartmann, Simone; Torsello, Giovanni; Horstmann, Rüdiger; Seifarth, Harald; Weissen-Plenz, Gabriele; Rutsch, Frank

    2011-01-01

    Abstract Mutations of the ENPP1 gene encoding ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) are associated with medial calcification in infancy. While the inhibitory role of matrix proteins such as osteopontin (OPN) with respect to atherosclerotic plaque calcification has been established, the role of NPP1 in plaque calcification is not known. We assessed the degree of plaque calcification (computed tomography), NPP1 and OPN localization (immunohistochemistry) and expression (RT-PCR) in a cohort of 45 patients undergoing carotid endatherectomy for significant stenosis of the internal carotid artery and in normal arteries (N= 50). We correlated NPP1 and OPN expression levels to the degree of plaque calcification, to pro-atherogenic factors and statin therapy. NPP1 was demonstrated in the base and in the shoulder of atherosclerotic plaques. Compared to normal arteries and non-calcified plaques, in calcified plaques NPP1 mRNA was decreased (P < 0.0001). OPN mRNA levels were up-regulated in carotid atheroma. NPP1 and OPN expression levels positively correlated with the degree of plaque calcification (R= 0.54, P= 0.00019 and R= 0.46, P= 0.017, respectively) and with risk factors of atherosclerosis. Expression of the calcification inhibitor NPP1 is down-regulated in calcified atherosclerotic plaques. Our correlation data point to a counter-active mechanism, which in the end turns out to be insufficient to prevent further progression of calcification. PMID:20015201

  8. Aggregation and disaggregation of senile plaques in Alzheimer disease

    PubMed Central

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

    1997-01-01

    We quantitatively analyzed, using laser scanning confocal microscopy, the three-dimensional structure of individual senile plaques in Alzheimer disease. We carried out the quantitative analysis using statistical methods to gain insights about the processes that govern Aβ peptide deposition. Our results show that plaques are complex porous structures with characteristic pore sizes. We interpret plaque morphology in the context of a new dynamical model based on competing aggregation and disaggregation processes in kinetic steady-state equilibrium with an additional diffusion process allowing Aβ deposits to diffuse over the surface of plaques. PMID:9207140

  9. Assessment of plaque assay methods for alphaviruses.

    PubMed

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

    2013-01-01

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

  10. The molecular concept of atheromatous plaques.

    PubMed

    Thent, Zar Chi; Chakraborty, Chiranjib; Mahakkanukrauh, Pasuk; Kosai, Nik; Rajan, Reynu; Das, Srijit

    2016-05-02

    Recently, there are scientific attempts to devise new drugs in the biotechnology industry in order to treat various diseases including atherosclerosis. Atherosclerosis is considered to be a leading cause of death throughout the world. Atherosclerosis involves oxidative damage to the cells with production of reactive oxygen species (ROS). Development of atheromatous plaques in the arterial wall is a common feature. Specific inflammatory markers pertaining to the arterial wall in atherosclerosis may be useful for both diagnosis and treatment. These include macrophage inhibiting factor (MIF), leucocytes and P-selectin. Modern therapeutic paradigms involving endothelial progenitor cells therapy, angiotensin II type-2 (AT2R) and ATP-activated purinergic receptor therapy are notable to mention. Future drugs may be designed aiming three signalling mechanisms of AT2R which are (a) activation of protein phosphatases resulting in protein dephosphorylation (b) activation of bradykinin/nitric oxide/cyclic guanosine 3',5'-monophosphate pathway by vasodilation and (c) stimulation of phospholipase A(2) and release of arachidonic acid. Drugs may also be designed to act on ATP-activated purinergic receptor channel type P2X7 molecules which acts on cardiovascular system. In the present review, we discuss the molecular concept of the inflammatory process occurring inside the arterial wall. Better understanding of the vascular inflammatory processes and the cells involved in the formation of plaques, may prove to be beneficial for future diagnosis, clinical treatment and planning innovative novel anti-atherosclerotic drugs.

  11. Effect of Chlorhexidine with Fluoride Mouthrinse on Plaque Accumulation, Plaque pH - A Double Blind Parallel Randomized Clinical Trial

    PubMed Central

    Saha, Sabyasachi; Singh, Sanjay

    2016-01-01

    Introduction Mouthwashes are important means used in chemical control of dental plaque. There is strong evidence suggestive of better effectiveness, when fluoride is added to chlorhexidine mouthwash. Aim To assess the anti-plaque efficacy of Chlorhexidine combined with Fluoride mouthwash and to measure its impact on plaque accumulation and on plaque pH. Materials and Methods Initially 100 subjects were screened. A double blind, parallel randomized clinical trial was conducted on 30 subjects after applying inclusion and exclusion criteria. Other independent variables were matched before randomly allocating them in three groups: Group A-Chlorhexidine as positive control, Group B-Chlorhexidine + Fluoride as test group and Group C- Distilled water as negative control. Oral prophylaxis of participants was done before onset of the study. Plaque pH was assessed before and immediately after rinsing at 0, 5 and 10 minutes interval and after 7 days with digital pH electrode (pHepR pH meter, Hanna Instruments R10285) and accumulation of plaque was recorded by Turesky et al., modification of Quigley Hein Plaque Index (1970). ANOVA test was used for statistical analysis. Results Although there was a statistically significant reduction in mean plaque scores from baseline to seven days in both Groups A and B, Group B showed better anti-plaque efficacy . Almost equal drop in plaque pH was seen for both the groups at 5 and 10 minutes. Conclusion Better anti-plaque efficacy was observed in Group B (Chlorhexidine and Fluoride combination) with minimum variation of plaque pH. PMID:27630956

  12. Toward tsunami early warning system in Indonesia by using rapid rupture durations estimation

    NASA Astrophysics Data System (ADS)

    Madlazim, Physics Department, Faculty Mathematics; Sciences of Surabaya State University (UNESA) Jl. Ketintang, Surabaya 60231, Indonesia

    2012-06-01

    Indonesia has Indonesian Tsunami Early Warning System (Ina-TEWS) since 2008. The Ina-TEWS has used automatic processing on hypocenter; Mwp, Mw (mB) and Mj. If earthquake occurred in Ocean, depth < 70 km and magnitude > 7, then Ina-TEWS announce early warning that the earthquake can generate tsunami. However, the announcement of the Ina-TEWS is still not accuracy. Purposes of this research are to estimate earthquake rupture duration of large Indonesia earthquakes that occurred in Indian Ocean, Java, Timor sea, Banda sea, Arafura sea and Pasific ocean. We analyzed at least 330 vertical seismogram recorded by IRIS-DMC network using a direct procedure for rapid assessment of earthquake tsunami potential using simple measures on P-wave vertical seismograms on the velocity records, and the likelihood that the high-frequency, apparent rupture duration, Tdur. Tdur can be related to the critical parameters rupture length (L), depth (z), and shear modulus (μ) while Tdur may be related to wide (W), slip (D), z or μ. Our analysis shows that the rupture duration has a stronger influence to generate tsunami than Mw and depth. The rupture duration gives more information on tsunami impact, Mo/μ, depth and size than Mw and other currently used discriminants. We show more information which known from the rupture durations. The longer rupture duration, the shallower source of the earthquake. For rupture duration greater than 50 s, the depth less than 50 km, Mw greater than 7, the longer rupture length, because Tdur is proportional L and greater Mo/μ. Because Mo/μ is proportional L. So, with rupture duration information can be known information of the four parameters. We also suggest that tsunami potential is not directly related to the faulting type of source and for events that have rupture duration greater than 50 s, the earthquakes generated tsunami. With available real-time seismogram data, rapid calculation, rupture duration discriminant can be completed within 4-5 min

  13. Toward tsunami early warning system in Indonesia by using rapid rupture durations estimation

    SciTech Connect

    Madlazim

    2012-06-20

    Indonesia has Indonesian Tsunami Early Warning System (Ina-TEWS) since 2008. The Ina-TEWS has used automatic processing on hypocenter; Mwp, Mw (mB) and Mj. If earthquake occurred in Ocean, depth < 70 km and magnitude > 7, then Ina-TEWS announce early warning that the earthquake can generate tsunami. However, the announcement of the Ina-TEWS is still not accuracy. Purposes of this research are to estimate earthquake rupture duration of large Indonesia earthquakes that occurred in Indian Ocean, Java, Timor sea, Banda sea, Arafura sea and Pasific ocean. We analyzed at least 330 vertical seismogram recorded by IRIS-DMC network using a direct procedure for rapid assessment of earthquake tsunami potential using simple measures on P-wave vertical seismograms on the velocity records, and the likelihood that the high-frequency, apparent rupture duration, T{sub dur}. T{sub dur} can be related to the critical parameters rupture length (L), depth (z), and shear modulus ({mu}) while T{sub dur} may be related to wide (W), slip (D), z or {mu}. Our analysis shows that the rupture duration has a stronger influence to generate tsunami than Mw and depth. The rupture duration gives more information on tsunami impact, Mo/{mu}, depth and size than Mw and other currently used discriminants. We show more information which known from the rupture durations. The longer rupture duration, the shallower source of the earthquake. For rupture duration greater than 50 s, the depth less than 50 km, Mw greater than 7, the longer rupture length, because T{sub dur} is proportional L and greater Mo/{mu}. Because Mo/{mu} is proportional L. So, with rupture duration information can be known information of the four parameters. We also suggest that tsunami potential is not directly related to the faulting type of source and for events that have rupture duration greater than 50 s, the earthquakes generated tsunami. With available real-time seismogram data, rapid calculation, rupture duration discriminant

  14. Prevalence and risk factors for atherosclerotic carotid stenosis and plaque

    PubMed Central

    Woo, Shin Young; Joh, Jin Hyun; Han, Sang-Ah; Park, Ho-Chul

    2017-01-01

    Abstract Atherosclerotic carotid stenosis (ACS) is a major cause of ischemic stroke. Screening for asymptomatic ACS is important to identify the patients who require longitudinal surveillance, medication, or endovascular surgery. The aim of this study was to assess the prevalence and risk factors for ACS and carotid plaque (CP) in Korea using a population-based screening study. We recruited participants during visits to several community welfare centers in Korea. The baseline characteristics of the study population were collected. All patients underwent duplex ultrasonography to examine their bilateral carotid arteries. ACS was defined as the presence of plaque with ≥50% vessel diameter reduction and peak systolic velocity (PSV) ≥125 cm/s or PSV ratio ≥2.0. CP was defined as the presence of plaque with <50% vessel diameter reduction. The Mann–Whitney test, χ2 test, Fisher exact test, and logistic regression were used in the statistical analysis. A total of 3030 participants were enrolled in this study (male 43.7% and female 56.3%). The prevalence of ACS and CP was 1.1% and 5.7%, respectively. Significant risk factors for CP included age ≥80 years (odds ratio [OR], 8.11; 95% confidence interval [CI], 3.45–18.93), male sex (OR, 2.16; 95% CI, 1.29–3.61), hypertension (OR, 1.72; 95% CI, 1.21–2.45), and hyperlipidemia (OR, 1.84; 95% CI, 1.30–2.62). The presence of ACS was significantly associated with age (OR, 1.07; 95% CI, 1.03–1.12), hypertension (OR, 3.16; 95% CI, 1.34–7.46), and being an ex-smoker (OR, 6.81; 95% CI, 1.66–27.93) or current smoker (OR, 6.97; 95% CI, 1.78–27.31) after adjusting for confounding factors. This population-based screening study revealed that ACS was uncommon and had a prevalence of 1.1% in the study population. Age, hypertension, and smoking were risk factors for ACS. Further investigations into the prevalence and risk factors of ACS are required, as are studies on the cost-effectiveness of a national screening

  15. Creep-rupture reliability analysis

    NASA Technical Reports Server (NTRS)

    Peralta-Duran, A.; Wirsching, P. H.

    1984-01-01

    A probabilistic approach to the correlation and extrapolation of creep-rupture data is presented. Time temperature parameters (TTP) are used to correlate the data, and an analytical expression for the master curve is developed. The expression provides a simple model for the statistical distribution of strength and fits neatly into a probabilistic design format. The analysis focuses on the Larson-Miller and on the Manson-Haferd parameters, but it can be applied to any of the TTP's. A method is developed for evaluating material dependent constants for TTP's. It is shown that optimized constants can provide a significant improvement in the correlation of the data, thereby reducing modelling error. Attempts were made to quantify the performance of the proposed method in predicting long term behavior. Uncertainty in predicting long term behavior from short term tests was derived for several sets of data. Examples are presented which illustrate the theory and demonstrate the application of state of the art reliability methods to the design of components under creep.

  16. Rupture of lenticulostriate artery aneurysms.

    PubMed

    Heck, Olivier; Anxionnat, René; Lacour, Jean-Christophe; Derelle, Anne-Laure; Ducrocq, Xavier; Richard, Sébastien; Bracard, Serge

    2014-02-01

    The authors report on 3 rare cases of ruptured lenticulostriate artery (LSA) aneurysms that were heralded by deep cerebral hematomas. The hematomas were unilateral in 2 cases and bilateral in 1; in the bilateral case, only a single LSA aneurysm could be identified on the right side of the brain. Because of their small size (≤ 2 mm), fusiform aspect, and deep location within the brain, all of the aneurysms were treated conservatively. There was no hemorrhage recurrence, and follow-up angiography demonstrated spontaneous thrombosis in 2 of the 3 cases. The clinical course was favorable in 2 of the 3 patients. The course in the patient with the bilateral hematoma was marked by an ischemic event after the initial episode, resulting in an aggravation of deficits. The cause of this second event was uncertain. Because our knowledge about the natural history of LSA aneurysms is incomplete, there is no consensus concerning a therapeutic strategy. The authors' experience in 3 reported cases leads them to think that a conservative approach involving close angiographic monitoring may be proposed as first-line treatment. If the monitored aneurysm then persists or grows in size, its occlusion should be considered. Nonetheless, other studies are needed to further strengthen the legitimacy of this strategy.

  17. Plantaris rupture: why is it important?

    PubMed

    Rohilla, Seema; Jain, Nitin; Yadav, Rohtas

    2013-01-22

    Plantaris muscle is accessory plantar flexor of calf, a vestigial muscle of triceps surae complex. Its importance lies in the fact that its rupture cans mimic deep vein thrombosis (DVT). Sometimes when there is rupture of Achilles tendon, intact plantaris can still cause plantar flexion at ankle presenting a confusing picture. We present one such case of plantaris rupture confused by radiology resident with DVT. A 51-year-old man had a feeling as if kicked in back of calf along with a snapping sound and severe pain while playing tennis. On seeing fluid between muscle plane and a hypoechoic structure radiology resident labelled it DVT. MRI suggested ruptured plantaris as fluid and muscle stump were seen between gastronemius and soleus. Patient was treated conservatively with rest, ice compression and elevated leg and showed significant reduction in pain and swelling.

  18. Acute Iliac Artery Rupture: Endovascular Treatment

    SciTech Connect

    Chatziioannou, A.; Mourikis, D.; Katsimilis, J.; Skiadas, V. Koutoulidis, V.; Katsenis, K.; Vlahos, L.

    2007-04-15

    The authors present 7 patients who suffered iliac artery rupture over a 2 year period. In 5 patients, the rupture was iatrogenic: 4 cases were secondary to balloon angioplasty for iliac artery stenosis and 1 occurred during coronary angioplasty. In the last 2 patients, the rupture was secondary to iliac artery mycotic aneurysm. Direct placement of a stent-graft was performed in all cases, which was dilated until extravasation was controlled. Placement of the stent-graft was successful in all the cases, without any complications. The techniques used, results, and mid-term follow-up are presented. In conclusion, endovascular placement of a stent-graft is a quick, minimally invasive, efficient, and safe method for emergency treatment of acute iliac artery rupture, with satisfactory short- and mid-term results.

  19. Cognitive frames in psychology: demarcations and ruptures.

    PubMed

    Yurevich, Andrey V

    2009-06-01

    As there seems to be a recurrent feeling of crisis in psychology, its present state is analyzed in this article. The author believes that in addition to the traditional manifestations that have dogged psychology since it emerged as an independent science some new features of the crisis have emerged. Three fundamental "ruptures" are identified: the "horizontal" rupture between various schools and trends, the "vertical" rupture between natural science and humanitarian psychology, and the "diagonal" rupture between academic research and applied practice of psychology. These manifestations of the crisis of psychology have recently been compounded by the crisis of its rationalistic foundations. This situation is described in terms of the cognitive systems in psychology which include meta-theories, paradigms, sociodigms and metadigms.

  20. Increased brain iron coincides with early plaque formation in a mouse model of Alzheimer's disease

    SciTech Connect

    Leskovjan, A.C.; Miller, L.; Kretlow, A.; Lanzirotti, A.; Barrea,R.; Vogt, S.

    2010-11-23

    Elevated brain iron content, which has been observed in late-stage human Alzheimer's disease, is a potential target for early diagnosis. However, the time course for iron accumulation is currently unclear. Using the PSAPP mouse model of amyloid plaque formation, we conducted a time course study of metal ion content and distribution [iron (Fe), copper (Cu), and zinc (Zn)] in the cortex and hippocampus using X-ray fluorescence microscopy (XFM). We found that iron in the cortex was 34% higher than age-matched controls at an early stage, corresponding to the commencement of plaque formation. The elevated iron was not associated with the amyloid plaques. Interestingly, none of the metal ions were elevated in the amyloid plaques until the latest time point (56 weeks), where only the Zn content was significantly elevated by 38%. Since neuropathological changes in human Alzheimer's disease are presumed to occur years before the first cognitive symptoms appear, quantification of brain iron content could be a powerful marker for early diagnosis of Alzheimer's disease.

  1. Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

    PubMed Central

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

    2016-01-01

    Aim: The aim of this clinical study was to confirm the plaque removal efficacy of the Colgate 360 Whole Mouth Clean Toothbrush. Study Design: This was a single-center, monadic, case–controlled study with the 7 days duration. Materials and Methods: A total of eighty participants (56 male and 24 female) aged between 18 and 45 years with a minimum of 20 permanent teeth (excluding the third molars) without any prosthetic crowns and an initial plaque score of minimum 1.5 as determined by Modified Quigley-Hein Plaque Index (1970) participated in the study. There were two dropouts during the study duration, one male and one female. The participants were instructed to brush for 1 min, after which plaque index was recorded again. They were then instructed to brush their teeth twice a day for 1 min with the assigned toothbrush (Colgate 360 Whole Mouth Clean Toothbrush) and a commercially available fluoride toothpaste for the next 7 days. On the 7th day, all the participants were recalled for follow-up and plaque examination. The plaque index scores (pre- and post-brushing) were recorded, tabulated, and analyzed statistically. Results: The mean plaque indices reduced after brushing both on day 1 and day 7. There was also a reduction in mean plaque indices from day 1 to day 7. All these reductions were statistically significant (P < 0.001). The reduction in plaque scores was independent of the gender of the participants however female participants showed lower scores as compared to male participants (P < 0.001). Conclusion: The present study demonstrated a significant reduction in plaque scores with the use of Colgate 360 Whole Mouth Clean Soft Toothbrush throughout the study period. Continued use resulted in a further significant reduction in plaque scores irrespective of the gender of participants. PMID:27630494

  2. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-06

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach.

  3. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index

    PubMed Central

    Polzer, Stanislav; Gasser, T. Christian

    2015-01-01

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. PMID:26631334

  4. Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

    ERIC Educational Resources Information Center

    Seybold, C. A.; Harms, D. S.; Grossman, R. B.

    2009-01-01

    Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

  5. A case of traumatic pericardiophrenic rupture.

    PubMed

    Stefani, A; Brandi, L; Ruggiero, C; Lodi, R

    1998-12-01

    An unusual case of traumatic pericardiophrenic rupture is presented. The defect was limited to the central tendon of the diaphragm, with herniation of the stomach into the pericardial sac. A correct preoperative diagnosis was not made because laparotomy was quickly performed for splenic rupture. Successful operative repair of the tear was performed, with interrupted reabsorbable sutures. The case is discussed and the management of patients with these rare lesions is reviewed.

  6. The Rupture Behaviour Of Woven Fabrics Containing Kevlar Fibres

    NASA Astrophysics Data System (ADS)

    Mao, N.; Qu, J.; Darley, M.; Lingard, S.

    2012-07-01

    Woven fabrics containing high performance fibres are frequently used in spacecraft structures and the rupture behaviour of these fabrics heavily influences the performance of its final products. However, the initiation and propagation of a ruptured fracture in the woven fabrics is not clear and the interpretation of the results from different tear testing methods varies. Currently there is a lack of knowledge about both the characteristics of tear propagation woven fabrics containing high performance fibres such as Kevlar and the influence of the fabric structural parameters on the rupture behaviour of the fabrics; this knowledge gap creates difficulties for the engineering design and selection of suitable fabric materials to meet specific requirements in each application case involving such woven fabrics. In this paper, the tear propagations in a polyurethane-coated woven fabric containing Kevlar fibres based on two different tear testing standards are examined; the mechanism of tear propagation in woven fabrics and the influences of tear testing design on the interpretation of the results from different tear testing methods are discussed. It is expected that the results will guide both the engineering design of Kevlar woven fabric structures and the evaluation of the fabric performance.

  7. Mantle cell lymphoma presenting with spontaneous splenic rupture.

    PubMed

    Maeda-Sakagami, Yukako; Tanaka, Yasuhiro; Koba, Yusuke; Shinzato, Isaku; Ishikawa, Takayuki

    2016-08-01

    A 48-year-old man was transferred to our emergency room because of sudden-onset epigastric pain and nausea. Abdominal contrast-enhanced computed tomography (CT) showed splenomegaly with splenic infarction and intra-abdominal bleeding, suggestive of splenic rupture. An emergent open splenectomy was performed. His spleen was markedly swollen and showed continuous bleeding due to a laceration. On histopathological examination, his spleen was filled with abnormal tumor cells. He was diagnosed as having mantle cell lymphoma based on the findings of immunohistochemical and cytogenetic analyses of the spleen. Mantle cell lymphoma cells were identified in the bone marrow and ileum, and he was determined to be in stageIVA by positron emission tomography (PET)-CT. He was administered rituximab combined with hyper-CVAD/MA chemotherapy (R-hyper-CVAD/MA regimen). After two courses of the R-hyper-CVAD/MA regimen, he achieved complete response, as confirmed by PET-CT. He received four courses in total of the R-hyper-CVAD/MA regimen, followed sequentially by high-dose chemotherapy and autologous peripheral blood stem cell transplantation (auto-PBSCT). He is currently alive and free of disease. This is the 10(th) report of a mantle cell lymphoma case with spontaneous splenic rupture. We herein review previous reports and emphasize the importance of awareness of hematological malignancies when encountering a case with spontaneous splenic rupture.

  8. Lack of autologous tissue transmission of eosinophilic plaques in cats.

    PubMed

    Moriello, K A; Kunkle, G; Miller, L M; Crowley, A

    1990-07-01

    Autologous tissue transmission of spontaneously developing feline eosinophilic plaques was attempted in 5 cats. Macerated tissue from the plaque was vigorously rubbed onto 2 scarified skin sites in each cat. The inoculated areas were observed daily for 30 days. During that time, no clinical or histologic evidence of transmission was found.

  9. Immunochemical Characterization of Plaque Mutants of Simian Virus 40

    PubMed Central

    Ozer, H. L.; Takemoto, K. K.; Kirschstein, R. L.; Axelrod, D.

    1969-01-01

    Analysis of large and small plaque mutants of simian virus 40 using antisera prepared against each has revealed quantitative and possibly qualitative antigenic differences for each plaque type. A sensitive micro radioisotope precipitation test permitted evaluation of immunochemical similarities and differences of capsid antigens by inhibition of precipitation. PMID:4306300

  10. VIEW OF A BRONZE PLAQUE LOCATED AT THE FRONT OF ...

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

    VIEW OF A BRONZE PLAQUE LOCATED AT THE FRONT OF BUILDING 708. PLAQUE IS MOUNTED ON THE WALL JUST TO THE RIGHT SIDE OF THE CHAPEL'S ENTRANCE. - U.S. Naval Base, Pearl Harbor, Chapel, Corner of Oakley & Nimitz Street, Pearl City, Honolulu County, HI

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

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

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

  12. Lifting the Silver Flakes: The Pathogenesis and Management of Chronic Plaque Psoriasis

    PubMed Central

    Chong, Heng T.; Cowin, Allison J.

    2013-01-01

    Psoriasis is a common chronic inflammatory skin condition in which patients suffer from mild to chronic plaque skin plaques. The disease manifests through an excessive inflammatory response in the skin due to complex interactions between different genetic and environmental factors. Psoriasis can affect the physical, emotional, and psychosocial well-being of patients, and currently there is no cure with treatments focusing primarily on the use of anti-inflammatory agents to control disease symptoms. Traditional anti-inflammatory agents can cause immunosuppression and adverse systemic effects. Further understanding of the disease has led to current areas of research aiming at the development of selective molecular targets to suppress the pathogenic immune responses. PMID:24062996

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

    PubMed Central

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

    2015-01-01

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

  14. Evidence for surface rupture in 1868 on the Hayward fault in north Oakland and major rupturing in prehistoric earthquakes

    USGS Publications Warehouse

    Lienkaemper, J.J.; Williams, P.L.

    1999-01-01

    WGCEP90 estimated the Hayward fault to have a high probability (0.45 in 30 yr) of producing a future M7 Bay Area earthquake. This was based on a generic recurrence time and an unverified segmentation model, because there were few direct observations for the southern fault and none for the northern Hayward fault. To better constrain recurrence and segmentation of the northern Hayward fault, we trenched in north Oakland. Unexpectedly, we observed evidence of surface rupture probably from the M7 1868 earthquake. This extends the limit of that surface rupture 13 km north of the segmentation boundary used in the WGCEP90 model and forces serious re-evaluation of the current two-segment paradigm. Although we found that major prehistoric ruptures have occurred here, we could not radiocarbon date them. However, the last major prehistoric event appears correlative with a recently recognized event 13 km to the north dated AD 1640-1776. Copyright 1999 by the American Geophysical Union.

  15. Cap inflammation leads to higher plaque cap strain and lower cap stress: An MRI-PET/CT-based FSI modeling approach.

    PubMed

    Tang, Dalin; Yang, Chun; Huang, Sarayu; Mani, Venkatesh; Zheng, Jie; Woodard, Pamela K; Robson, Philip; Teng, Zhongzhao; Dweck, Marc; Fayad, Zahi A

    2017-01-04

    Plaque rupture may be triggered by extreme stress/strain conditions. Inflammation is also implicated and can be imaged using novel imaging techniques. The impact of cap inflammation on plaque stress/strain and flow shear stress were investigated. A patient-specific MRI-PET/CT-based modeling approach was used to develop 3D fluid-structure interaction models and investigate the impact of inflammation on plaque stress/strain conditions for better plaque assessment. 18FDG-PET/CT and MRI data were acquired from 4 male patients (average age: 66) to assess plaque characteristics and inflammation. Material stiffness for the fibrous cap was adjusted lower to reflect cap weakening causing by inflammation. Setting stiffness ratio (SR) to be 1.0 (fibrous tissue) for baseline, results for SR=0.5, 0.25, and 0.1 were obtained. Thin cap and hypertension were also considered. Combining results from the 4 patients, mean cap stress from 729 cap nodes was lowered by 25.2% as SR went from 1.0 to 0.1. Mean cap strain value for SR=0.1 was 0.313, 114% higher than that from SR=1.0 model. The thin cap SR=0.1 model had 40% mean cap stress decrease and 81% cap strain increase compared with SR=1.0 model. The hypertension SR=0.1 model had 19.5% cap stress decrease and 98.6% cap strain increase compared with SR=1.0 model. Differences of flow shear stress with 4 different SR values were limited (<10%). Cap inflammation may lead to large cap strain conditions when combined with thin cap and hypertension. Inflammation also led to lower cap stress. This shows the influence of inflammation on stress/strain calculations which are closely related to plaque assessment.

  16. Automatic classification of atherosclerotic plaques imaged with intravascular OCT

    PubMed Central

    Rico-Jimenez, Jose J.; Campos-Delgado, Daniel U.; Villiger, Martin; Otsuka, Kenichiro; Bouma, Brett E.; Jo, Javier A.

    2016-01-01

    Intravascular optical coherence tomography (IV-OCT) allows evaluation of atherosclerotic plaques; however, plaque characterization is performed by visual assessment and requires a trained expert for interpretation of the large data sets. Here, we present a novel computational method for automated IV-OCT plaque characterization. This method is based on the modeling of each A-line of an IV-OCT data set as a linear combination of a number of depth profiles. After estimating these depth profiles by means of an alternating least square optimization strategy, they are automatically classified to predefined tissue types based on their morphological characteristics. The performance of our proposed method was evaluated with IV-OCT scans of cadaveric human coronary arteries and corresponding tissue histopathology. Our results suggest that this methodology allows automated identification of fibrotic and lipid-containing plaques. Moreover, this novel computational method has the potential to enable high throughput atherosclerotic plaque characterization. PMID:27867716

  17. Are herbal mouthwash efficacious over chlorhexidine on the dental plaque?

    PubMed Central

    Gupta, Devanand; Nayan, Swapna; Tippanawar, Harshad K.; Patil, Gaurav I.; Jain, Ankita; Momin, Rizwan K.; Gupta, Rajendra Kumar

    2015-01-01

    Aim: To compare the effect of herbal extract mouthwash and chlorhexidine mouthwash on the dental plaque level. Materials and Methods: The subjects (60 healthy medical students aged ranges between 20 and 25 years) were randomly divided into two groups, that is, the herbal group and the chlorhexidine gluconate mouthwash group. The data were collected at the baseline and 3 days. The plaque was disclosed using erythrosine disclosing agent and their scores were recorded using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Statistical analysis was carried out later to compare the effect of all the two groups. Results: Our result showed that the chlorhexidine group shows a greater decrease in plaque score followed by herbal extract, but the result was statistically insignificant. Conclusion: The results indicate that herbal mouthwash may prove to be an effective agent owing to its ability to reduce plaque level, especially in low socioeconomic strata. PMID:26130940

  18. Lumen irregularity dominates the relationship between mechanical stress condition, fibrous-cap thickness, and lumen curvature in carotid atherosclerotic plaque.

    PubMed

    Teng, Zhongzhao; Sadat, Umar; Ji, Guangyu; Zhu, Chengcheng; Young, Victoria E; Graves, Martin J; Gillard, Jonathan H

    2011-03-01

    High mechanical stress condition over the fibrous cap (FC) has been widely accepted as a contributor to plaque rupture. The relationships between the stress, lumen curvature, and FC thickness have not been explored in detail. In this study, we investigate lumen irregularity-dependent relationships between mechanical stress conditions, local FC thickness (LT(FC)), and lumen curvature (LC(lumen)). Magnetic resonance imaging slices of carotid plaque from 100 patients with delineated atherosclerotic components were used. Two-dimensional structure-only finite element simulations were performed for the mechanical analysis, and maximum principal stress (stress-P₁) at all integral nodes along the lumen was obtained. LT(FC) and LC(lumen) were computed using the segmented contour. The lumen irregularity (L-δir) was defined as the difference between the largest and the smallest lumen curvature. The results indicated that the relationship between stress-P₁, LT(FC), and LC(lumen) is largely dependent on L-δir. When L-δir ≥ .31 (irregular lumen), stress-P₁ strongly correlated with lumen curvature and had a weak/no correlation with local FC thickness, and in 73.4% of magnetic resonance (MR) slices, the critical stress (maximum of stress-P₁ over the diseased region) was found at the site where the lumen curvature was large. When L-δir ≤ 0.28 (relatively round lumen), stress-P₁ showed a strong correlation with local FC thickness but weak/no correlation with lumen curvature, and in 71.7% of MR slices, the critical stress was located at the site of minimum FC thickness. Using lumen irregularity as a method of identifying vulnerable plaque sites by referring to the lumen shape is a novel and simple method, which can be used for mechanics-based plaque vulnerability assessment.

  19. Support vector machine based classification and mapping of atherosclerotic plaques using fluorescence lifetime imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Fatakdawala, Hussain; Gorpas, Dimitris S.; Bec, Julien; Ma, Dinglong M.; Yankelevich, Diego R.; Bishop, John W.; Marcu, Laura

    2016-02-01

    The progression of atherosclerosis in coronary vessels involves distinct pathological changes in the vessel wall. These changes manifest in the formation of a variety of plaque sub-types. The ability to detect and distinguish these plaques, especially thin-cap fibroatheromas (TCFA) may be relevant for guiding percutaneous coronary intervention as well as investigating new therapeutics. In this work we demonstrate the ability of fluorescence lifetime imaging (FLIm) derived parameters (lifetime values from sub-bands 390/40 nm, 452/45 nm and 542/50 nm respectively) for generating classification maps for identifying eight different atherosclerotic plaque sub-types in ex vivo human coronary vessels. The classification was performed using a support vector machine based classifier that was built from data gathered from sixteen coronary vessels in a previous study. This classifier was validated in the current study using an independent set of FLIm data acquired from four additional coronary vessels with a new rotational FLIm system. Classification maps were compared to co-registered histological data. Results show that the classification maps allow identification of the eight different plaque sub-types despite the fact that new data was gathered with a different FLIm system. Regions with diffuse intimal thickening (n=10), fibrotic tissue (n=2) and thick-cap fibroatheroma (n=1) were correctly identified on the classification map. The ability to identify different plaque types using FLIm data alone may serve as a powerful clinical and research tool for studying atherosclerosis in animal models as well as in humans.

  20. Refinement of the Modified Navy Plaque Index to increase plaque scoring efficiency in gumline and interproximal tooth areas.

    PubMed

    Rustogi, K N; Curtis, J P; Volpe, A R; Kemp, J H; McCool, J J; Korn, L R

    1992-01-01

    To improve the assessment of plaque present on teeth, a new index, based on the original Modified Navy Plaque Index, has been developed. The primary modifications to the original Modified Navy Plaque Index were: (1) extending areas F (distal) and D (mesial) into the region just below the interproximal contact point, and (2) extending areas C and A so as to increase the gumline (or marginal gingiva) region. The new index assesses the amount of plaque in the tooth area bounded by the tooth contact, the free gingival margin, and mesial or distal line angles. The use of this new index enables the examiner to evaluate and record both the gumline (or marginal areas) and interproximal areas of the tooth, thus giving these an anatomical areas an increased importance. A pilot clinical assessment study was conducted to utilize this new index in evaluating the plaque removal efficacy of five manual toothbrushes. The results from this pilot study indicated that, when the new plaque scoring index was used, significant differences between pre-toothbrushing and post-toothbrushing plaque scores (as well as among toothbrush groups) could be demonstrated. Further, these differences (plaque removal efficacy) were demonstrated on an interproximal (mesial and distal) basis and a gumline (or gingival margin) basis, as well as on a whole mouth basis.

  1. Accelerated Plaque Formation by Fowlpox Virus in the Presence of Chymotrypsin

    PubMed Central

    Asch, Bonnie B.; Gifford, George E.

    1969-01-01

    Chymotrypsin enhanced fowlpox virus plaque formation in chick embryo cell cultures. A simplified plaque assay for fowlpox virus is described. Plaques were produced in 3 days when chymotrypsin was included in a serum-free fluid overlay. Plaques were also produced in 5 to 6 days under an agar overlay when a medium containing fetal calf serum was employed. Kinetics of plaque formation were also studied, and it was shown that fowlpox virus plaque diameters grow at a linear rate. Images PMID:4905607

  2. Vulnerable atherosclerotic plaque detection by resonance Raman spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  3. Effect of listerine on dental plaque and gingivitis.

    PubMed

    Fornell, J; Sundin, Y; Lindhe, J

    1975-01-01

    The present study was performed in 10 adults in order to evaluate the effect of an antiseptic mouthrinse (Listerine) on the rate of dental plaque formation and gingivitis development during a 2-week period when all efforts towards active mechanical oral hygiene were withdrawn. The study was performed as a crossover study and was carried out during four consecutive 2-week periods. During the first and third periods (preparatory periods) the participants were subjected to repeated professional tooth cleanings in order to establish plaque- and gingivitis-free dentitions. During the second and fourth periods (test and control periods) the participants were not allowed to brush their teeth but rinsed their mouths three times a day with Listerine or a placebo mouthwash. Plaque Index, Gingival Index, gingival fluid flow, and crevicular leukocytes were assessed on d 0, 2, 4, 7, and 14. On d 7 and 14, dental plaque was removed from the right and left jaws respectively and the wet weights determined. The chemotactic activity elaborated by the plaques was studied in Boyden chambers. During the Listerine test period, significantly lower Plaque and Gingival Index values were scored and lower amounts of plaque could be sampled in comparison to the control period.

  4. Sulfadiazines prevent plaque formation and gingivitis in beagles.

    PubMed

    Howell, T H; Reddy, M S; Weber, H P; Li, K L; Alfano, M C; Vogel, R; Tanner, A C; Williams, R C

    1990-07-01

    The effect of zinc sulfadiazine (ZnSD) and silver sulfadiazine (AgSD) on developing plaque formation and gingivitis was studied in 12 beagle dogs over a 14-week period. Plaque and gingival indices were used to measure plaque formation and gingivitis. During a 2-wk baseline period each dog was brought to optimal gingival health with prophylaxis and tooth brushing. Thereafter, 4 dogs were treated twice daily with topical application of 3.0% zinc sulfadiazine; 4 dogs were treated with 2.0% silver sulfadiazine while 4 dogs treated with placebo gel served as controls over a 12-wk treatment period. At wk 2 of treatment, all three groups of dogs showed an increase in plaque build-up on their teeth from baseline. By wk 6, plaque accumulation on the teeth was significantly less in dogs treated with either ZnSD or AgSD compared to control dogs. At wk 2 of treatment, gingival inflammation was increased from baseline in all three groups. Thereafter, over the course of the 12-wk treatment period, gingival inflammation in the ZnSD and the AgSD treated dogs was significantly less than the placebo treated dogs. The data indicate that both ZnSD and AgSD inhibit developing plaque formation in beagles. This significant inhibition of plaque formation was accompanied by a significant reduction in gingival inflammation.

  5. Systematic review of pleural plaques and lung function

    PubMed Central

    Kerper, Laura E.; Lynch, Heather N.; Zu, Ke; Tao, Ge; Utell, Mark J.

    2015-01-01

    Abstract Context US EPA proposed a Reference Concentration for Libby amphibole asbestos based on the premise that pleural plaques are adverse and cause lung function deficits. Objective We conducted a systematic review to evaluate whether there is an association between pleural plaques and lung function and ascertain whether results were dependent on the method used to identify plaques. Methods Using the PubMed database, we identified studies that evaluated pleural plaques and lung function. We assessed each study for quality, then integrated evidence and assessed associations based on the Bradford Hill guidelines. We also compared the results of HRCT studies to those of X-ray studies. Results We identified 16 HRCT and 36 X-ray studies. We rated six HRCT and 16 X-ray studies as higher quality based on a risk-of-bias analysis. Half of the higher quality studies reported small but statistically significant mean lung function decrements associated with plaques. None of the differences were clinically significant. Many studies had limitations, such as inappropriate controls and/or insufficient adjustment for confounders. There was little consistency in the direction of effect for the most commonly reported measurements. X-ray results were more variable than HRCT results. Pleural plaques were not associated with changes in lung function over time in longitudinal studies. Conclusion The weight of evidence indicates that pleural plaques do not impact lung function. Observed associations are most likely due to unidentified abnormalities or other factors. PMID:25518994

  6. CD44 Targeting Magnetic Glyconanoparticles for Atherosclerotic Plaque Imaging

    PubMed Central

    El-Dakdouki, Mohammad H.; El-Boubbou, Kheireddine; Kamat, Medha; Huang, Ruiping; Abela, George S.; Kiupel, Matti; Zhu, David C.; Huang, Xuefei

    2013-01-01

    Purpose The cell surface adhesion molecule CD44 plays important roles in the initiation and development of atherosclerotic plaques. We aim to develop nanoparticles that can selectively target CD44 for the non-invasive detection of atherosclerotic plaques by magnetic resonance imaging. Methods Magnetic glyco-nanoparticles with hyaluronan immobilized on the surface have been prepared. The binding of these nanoparticles with CD44 in vitro was evaluated by enzyme linked immunosorbent assay, flow cytometry and confocal microscopy. In vivo magnetic resonance imaging of plaques was performed on an atherosclerotic rabbit model. Results The magnetic glyconanoparticles can selectively bind CD44. In T2* weighted magnetic resonance images acquired in vivo, significant contrast changes in aorta walls were observed with a very low dose of the magnetic nanoparticles, allowing the detection of atherosclerotic plaques. Furthermore, imaging could be performed without significant delay after probe administration. The selectivity of hyaluronan nanoparticles in plaque imaging was established by several control experiments. Conclusions Magnetic nanoparticles bearing surface hyaluronan enabled the imaging of atherosclerotic plaques in vivo by magnetic resonance imaging. The low dose of nanoparticles required, the possibility to image without much delay and the high biocompatibility are the advantages of these nanoparticles as contrast agents for plaque imaging. PMID:23568520

  7. RGS1 regulates myeloid cell accumulation in atherosclerosis and aortic aneurysm rupture through altered chemokine signalling

    PubMed Central

    Patel, Jyoti; McNeill, Eileen; Douglas, Gillian; Hale, Ashley B.; de Bono, Joseph; Lee, Regent; Iqbal, Asif J.; Regan-Komito, Daniel; Stylianou, Elena; Greaves, David R.; Channon, Keith M.

    2015-01-01

    Chemokine signalling drives monocyte recruitment in atherosclerosis and aortic aneurysms. The mechanisms that lead to retention and accumulation of macrophages in the vascular wall remain unclear. Regulator of G-Protein Signalling-1 (RGS1) deactivates G-protein signalling, reducing the response to sustained chemokine stimulation. Here we show that Rgs1 is upregulated in atherosclerotic plaque and aortic aneurysms. Rgs1 reduces macrophage chemotaxis and desensitizes chemokine receptor signalling. In early atherosclerotic lesions, Rgs1 regulates macrophage accumulation and is required for the formation and rupture of Angiotensin II-induced aortic aneurysms, through effects on leukocyte retention. Collectively, these data reveal a role for Rgs1 in leukocyte trafficking and vascular inflammation and identify Rgs1, and inhibition of chemokine receptor signalling as potential therapeutic targets in vascular disease. PMID:25782711

  8. Butyrylcholinesterase in the life cycle of amyloid plaques.

    PubMed

    Guillozet, A L; Smiley, J F; Mash, D C; Mesulam, M M

    1997-12-01

    Deposits of diffuse beta-amyloid (Abeta) may exist in the brain for many years before leading to neuritic degeneration and dementia. The factors that contribute to the putative transformation of the Abeta amyloid from a relatively inert to a pathogenic state remain unknown and may involve interactions with additional plaque constituents. Matching brain sections from 2 demented and 4 nondemented subjects were processed for the demonstration of Abeta immunoreactivity, butyrylcholinesterase (BChE) enzyme activity, and thioflavine S binding. Additional sections were processed for the concurrent demonstration of two or three of these markers. A comparative analysis of multiple cytoarchitectonic areas processed with each of these markers indicated that Abeta plaque deposits are likely to undergo three stages of maturation, ie, a "diffuse" thioflavine S-negative stage, a thioflavine S-positive (ie, compact) but nonneuritic stage, and a compact neuritic stage. A multiregional analysis showed that BChE-positive plaques were not found in cytoarchitectonic areas or cortical layers that contained only the thioflavine S-negative, diffuse type of Abeta plaques. The BChE-positive plaques were found only in areas containing thioflavine S-positive compact plaques, both neuritic and nonneuritic. Within such areas, almost all (>98%) BChE-containing plaques bound thioflavine S, and almost all (93%) thioflavine S plaques contained BChE. These results suggest that BChE becomes associated with amyloid plaques at approximately the same time that the Abeta deposit assumes a compact beta-pleated conformation. BChE may therefore participate in the transformation of Abeta from an initially benign form to an eventually malignant form associated with neuritic tissue degeneration and clinical dementia.

  9. Rupture Following Biceps-to-Triceps Tendon Transfer in Adolescents and Young Adults With Spinal Cord Injury:

    PubMed Central

    Merenda, Lisa A.; Rutter, Laure; Curran, Kimberly; Kozin, Scott H.

    2012-01-01

    Background: Tendon transfer surgery can restore elbow extension in approximately 70% of persons with tetraplegia and often results in antigravity elbow extension strength. However, we have noted an almost 15% rupture/attenuation rate. Objective: This investigation was conducted to analyze potential causes in adolescents/young adults with spinal cord injury (SCI) who experienced tendon rupture or attenuation after biceps-to-triceps transfer. Methods: Medical charts of young adults with SCI who underwent biceps-to-triceps transfer and experienced tendon rupture or attenuation were reviewed. Data collected by retrospective chart review included general demographics, surgical procedure(s), use and duration of antibiotic treatment, time from tendon transfer surgery to rupture/attenuation, and method of diagnosis. Results: Twelve subjects with tetraplegia (mean age, 19 years) who underwent biceps-to-triceps reconstruction with subsequent tendon rupture or attenuation were evaluated. Mean age at time of tendon transfer was 18 years (range, 14-21 years). A fluoroquinolone was prescribed for 42% (n=5) of subjects. Tendon rupture was noted in 67% (n=8), and attenuation was noted in 33% (n=4). Average length of time from surgery to tendon rupture/attenuation was 5.7 months (range, 3-10 months). Conclusion: Potential contributing causes of tendon rupture/attenuation after transfer include surgical technique, rehabilitation, co-contraction of the transfer, poor patient compliance, and medications. In this cohort, 5 subjects were prescribed fluoroquinolones that have a US Food and Drug Administration black box concerning tendon ruptures. Currently, all candidates for upper extremity tendon transfer reconstruction are counseled on the effects of fluoroquinolones and the potential risk for tendon rupture. PMID:23459326

  10. Novel methodology for 3D reconstruction of carotid arteries and plaque characterization based upon magnetic resonance imaging carotid angiography data.

    PubMed

    Sakellarios, Antonis I; Stefanou, Kostas; Siogkas, Panagiotis; Tsakanikas, Vasilis D; Bourantas, Christos V; Athanasiou, Lambros; Exarchos, Themis P; Fotiou, Evangelos; Naka, Katerina K; Papafaklis, Michail I; Patterson, Andrew J; Young, Victoria E L; Gillard, Jonathan H; Michalis, Lampros K; Fotiadis, Dimitrios I

    2012-10-01

    In this study, we present a novel methodology that allows reliable segmentation of the magnetic resonance images (MRIs) for accurate fully automated three-dimensional (3D) reconstruction of the carotid arteries and semiautomated characterization of plaque type. Our approach uses active contours to detect the luminal borders in the time-of-flight images and the outer vessel wall borders in the T(1)-weighted images. The methodology incorporates the connecting components theory for the automated identification of the bifurcation region and a knowledge-based algorithm for the accurate characterization of the plaque components. The proposed segmentation method was validated in randomly selected MRI frames analyzed offline by two expert observers. The interobserver variability of the method for the lumen and outer vessel wall was -1.60%±6.70% and 0.56%±6.28%, respectively, while the Williams Index for all metrics was close to unity. The methodology implemented to identify the composition of the plaque was also validated in 591 images acquired from 24 patients. The obtained Cohen's k was 0.68 (0.60-0.76) for lipid plaques, while the time needed to process an MRI sequence for 3D reconstruction was only 30 s. The obtained results indicate that the proposed methodology allows reliable and automated detection of the luminal and vessel wall borders and fast and accurate characterization of plaque type in carotid MRI sequences. These features render the currently presented methodology a useful tool in the clinical and research arena.

  11. Subpatch roughness in earthquake rupture investigations

    NASA Astrophysics Data System (ADS)

    Zielke, O.; Mai, P. M.

    2016-03-01

    Fault geometric complexities exhibit fractal characteristics over a wide range of spatial scales (<µm to > km) and strongly affect the rupture process at corresponding scales. Numerical rupture simulations provide a framework to quantitatively investigate the relationship between a fault's roughness and its seismic characteristics. Fault discretization, however, introduces an artificial lower limit to roughness. Individual fault patches are planar and subpatch roughness—roughness at spatial scales below fault patch size—is not incorporated. Does negligence of subpatch roughness measurably affect the outcome of earthquake rupture simulations? We approach this question with a numerical parameter space investigation and demonstrate that subpatch roughness significantly modifies the slip-strain relationship—a fundamental aspect of dislocation theory. Faults with subpatch roughness induce less strain than their planar-fault equivalents at distances beyond the length of a slipping fault. We further provide regression functions that characterize the stochastic effect subpatch roughness.

  12. Hydrogen sulfide production from subgingival plaque samples.

    PubMed

    Basic, A; Dahlén, G

    2015-10-01

    Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3 < 7 mm) and 35% had severe periodontal breakdown (CAL > 7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket.

  13. Linguine sign in musculoskeletal imaging: calf silicone implant rupture.

    PubMed

    Duryea, Dennis; Petscavage-Thomas, Jonelle; Frauenhoffer, Elizabeth E; Walker, Eric A

    2015-08-01

    Imaging findings of breast silicone implant rupture are well described in the literature. On MRI, the linguine sign indicates intracapsular rupture, while the presence of silicone particles outside the fibrous capsule indicates extracapsular rupture. The linguine sign is described as the thin, wavy hypodense wall of the implant within the hyperintense silicone on T2-weighted images indicative of rupture of the implant within the naturally formed fibrous capsule. Hyperintense T2 signal outside of the fibrous capsule is indicative of an extracapsular rupture with silicone granuloma formation. We present a rare case of a patient with a silicone calf implant rupture and discuss the MRI findings associated with this condition.

  14. Neutralization Assay for Chikungunya Virus Infection: Plaque Reduction Neutralization Test.

    PubMed

    Azami, Nor Azila Muhammad; Moi, Meng Ling; Takasaki, Tomohiko

    2016-01-01

    Neutralization assay is a technique that detects and quantifies neutralizing antibody in serum samples by calculating the percentage of reduction of virus activity, as the concentration of virus used is usually constant. Neutralizing antibody titer is conventionally determined by calculating the percentage reduction in total virus infectivity by counting and comparing number of plaques (localized area of infection due to cytopathic effect) with a standard amount of virus. Conventional neutralizing test uses plaque-reduction neutralization test (PRNT) to determine neutralizing antibody titers against Chikungunya virus (CHIKV). Here we describe the plaque reduction neutralization assay (PRNT) using Vero cell lines to obtain neutralizing antibody titers.

  15. The relationships between malocclusion, gingival inflammation, plaque and calculus.

    PubMed

    Buckley, L A

    1981-01-01

    Certain features of malocclusion considered important in relation to periodontal health were analyzed in a study of 300 subjects. It was found that plaque and gingival inflammation were not related to vertical incisor overbite, horizontal incisor overjet or posterior cuspal interdigitation. Individual tooth irregularity measured as tilting, rotation, displacement and crowding had a low but statistically significant correlation with plaque, calculus and gingival inflammation. However, the study showed that these features of malocclusion are far less important than the extent of plaque and calculus deposits in the development of gingival inflammation.

  16. Ex vivo detection of macrophages in atherosclerotic plaques using intravascular ultrasonic-photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Quang Bui, Nhat; Hlaing, Kyu Kyu; Lee, Yong Wook; Kang, Hyun Wook; Oh, Junghwan

    2017-01-01

    Macrophages are excellent imaging targets for detecting atherosclerotic plaques as they are involved in all the developmental stages of atherosclerosis. However, no imaging technique is currently capable of visualizing macrophages inside blood vessel walls. The current study develops an intravascular ultrasonic-photoacoustic (IVUP) imaging system combined with indocyanine green (ICG) as a contrast agent to provide morphological and compositional information about the targeted samples. Both tissue-mimicking vessel phantoms and atherosclerotic plaque-mimicking porcine arterial tissues are used to demonstrate the feasibility of mapping macrophages labeled with ICG by endoscopically applying the proposed hybrid technique. A delay pulse triggering technique is able to sequentially acquire photoacoustic (PA) and ultrasound (US) signals from a single scan without using any external devices. The acquired PA and US signals are used to reconstruct 2D cross-sectional and 3D volumetric images of the entire tissue with the ICG-loaded macrophages injected. Due to high imaging contrast and sensitivity, the IVUP imaging vividly reveals structural information and detects the spatial distribution of the ICG-labeled macrophages inside the samples. ICG-assisted IVUP imaging can be a feasible imaging modality for the endoscopic detection of atherosclerotic plaques.

  17. Traumatic rupture of the thoracic aorta

    PubMed Central

    Keen, G.; Bradbrook, R. A.; McGinn, F.

    1969-01-01

    Seven patients who had traumatic ruptures of the thoracic aorta are reported. Four of these died within a few hours of admission, allowing no opportunity for diagnosis or treatment. However, three survived long enough for elective surgery to be undertaken. A diagnosis of ruptured aorta was missed in one patient (case 2), and the difficulties of diagnosing this condition, even during thoracotomy, are emphasized. The value of serial chest radiography and forward aortography is discussed. Two of these patients underwent successful aortic repair, using left atrio-femoral bypass. Images PMID:5763507

  18. Rupture of the plantar fascia in athletes.

    PubMed

    Leach, R; Jones, R; Silva, T

    1978-06-01

    Symptoms resembling those of plantar fasciitis were seen in six athletes who were thought to have a partial rupture of the plantar fascia. Treatment, which included the use of crutches, anti-inflammatory agents, strapping of the arch, and ice packs, was successful in all but one patient who had a painful mass in the area of the previous rupture. After surgical excision of the painful mass and release of the fascia, he recovered. Five of the six athletes had been previously treated with repeated local injections of steroid.

  19. Tendon ruptures: mallet, flexor digitorum profundus.

    PubMed

    Yeh, Peter C; Shin, Steven S

    2012-08-01

    Mallet injuries are the most common closed tendon injury in the athlete. Flexor digitorum profundus ruptures are rare in baseball, but are common injuries in contact sports. The diagnosis for each condition is based on clinical examination, although radiographs should be evaluated for a possible bony component. Treatment for mallet injury depends on the athlete's goals of competition and understanding of the consequences of any treatment chosen. Gripping, throwing, and catching would be restricted or impossible with the injured finger immobilized. Treatment of FDP ruptures is almost always surgical and requires reattachment of the torn tendon to the distal phalanx.

  20. Mega-earthquakes rupture flat megathrusts.

    PubMed

    Bletery, Quentin; Thomas, Amanda M; Rempel, Alan W; Karlstrom, Leif; Sladen, Anthony; De Barros, Louis

    2016-11-25

    The 2004 Sumatra-Andaman and 2011 Tohoku-Oki earthquakes highlighted gaps in our understanding of mega-earthquake rupture processes and the factors controlling their global distribution: A fast convergence rate and young buoyant lithosphere are not required to produce mega-earthquakes. We calculated the curvature along the major subduction zones of the world, showing that mega-earthquakes preferentially rupture flat (low-curvature) interfaces. A simplified analytic model demonstrates that heterogeneity in shear strength increases with curvature. Shear strength on flat megathrusts is more homogeneous, and hence more likely to be exceeded simultaneously over large areas, than on highly curved faults.

  1. COMPARISON OF CLADDING CREEP RUPTURE MODELS

    SciTech Connect

    P. Macheret

    2000-06-12

    The objective of this calculation is to compare several creep rupture correlations for use in calculating creep strain accrued by the Zircaloy cladding of spent nuclear fuel when it has been emplaced in the repository. These correlations are used to calculate creep strain values that are then compared to a large set of experimentally measured creep strain data, taken from four different research articles, making it possible to determine the best fitting correlation. The scope of the calculation extends to six different creep rupture correlations.

  2. Comparison of JEV neutralization assay using pseudotyped JEV with the conventional plaque-reduction neutralization test.

    PubMed

    Lee, Hee-Jung; Min, Kyung-Il; Park, Ki Hoon; Choi, Hyo Jung; Kim, Min-Kyoung; Ahn, Chi-Young; Hong, Young-Jin; Kim, Young Bong

    2014-05-01

    We previously reported the development of a neutralization assay system for evaluating Japanese Encephalitis Virus (JEV) neutralizing antibody (NAb) using pseudotyped-JEV (JEV-PV). JEV-PV-based neutralization assay offers several advantages compared with the current standard plaque-reduction neutralization test (PRNT), including simplicity, safety, and speed. To evaluate the suitability of the JEV-PV assay as new replacement neutralization assay, we compared its repeatability, reproducibility, specificity, and correlated its results with those obtained using the PRNT. These analyses showed a close correlation between the results obtained with the JEV-PV assay and the PRNT, using the 50% plaque reduction method as a standard for measuring NAb titers to JEV. The validation results met all analytical acceptance criteria. These results suggest that the JEV-PV assay could serve as a safe and simple method for measuring NAb titer against JEV and could be used as an alternative approach for assaying the potency of JEV neutralization.

  3. Earthquake Stress Drop in Rupture Patches and Rupture Barriers on Gofar Transform Fault, East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Moyer, P. A.; Boettcher, M. S.; McGuire, J. J.; Collins, J. A.

    2014-12-01

    The largest earthquakes on mid-ocean ridge transform faults (RTFs) exhibit the most systematic behaviors known in seismology. On the fast slipping Gofar transform fault on the East Pacific Rise (EPR), Mw ~6.0 earthquakes occur every ~5 years and repeatedly rupture the same asperities (fault patches), suggesting that the intervening fault segments (rupture barriers) stop the propagation of the largest earthquakes. In 2008, an ocean bottom seismometer (OBS) deployment captured the end of a seismic cycle on Gofar transform fault [McGuire et al., 2012]. We determine stress drop for earthquakes recorded during this experiment to investigate how the source properties of moderate sized earthquakes (3.0 < Mw < 5.5) differ between the rupture patch and rupture barrier fault segments. The OBS experiment on Gofar transform fault recorded an extensive foreshock sequence localized within a 10 km rupture barrier, the Mw 6.0 mainshock and its aftershocks that occurred in a ~10 km rupture patch, and an earthquake swarm that was located in a second rupture barrier adjacent to the ridge-transform intersection. Using waveforms recorded with a sample rate of 50 Hz on the OBS accelerometers, we calculate stress drop using the Madariaga [1976] circular crack model, with the corner frequency derived from an empirical Green's function (EGF) method, and seismic moment obtained by fitting an omega-squared source model to the low frequency amplitude of individual event spectra. Results for ~300 earthquakes in the foreshock, aftershock, and swarm zones have a range of stress drops from 0.2 to 50 MPa. Values for the best constrained 10% of earthquakes show a weighted average stress drop in the aftershock zone that is more than twice the weighted average stress drop in the foreshock zone (3.5 MPa and 1.1 MPa, respectively). These variations in earthquake stress drop reflect systematic differences in along strike fault zone properties between rupture patches and rupture barriers on Gofar

  4. Assessment of dental plaque by optoelectronic methods

    NASA Astrophysics Data System (ADS)

    Negrutiu, Meda-Lavinia; Sinescu, Cosmin; Bortun, Cristina Maria; Levai, Mihaela-Codrina; Topala, Florin Ionel; Crǎciunescu, Emanuela Lidia; Cojocariu, Andreea Codruta; Duma, Virgil Florin; Podoleanu, Adrian Gh.

    2016-03-01

    The formation of dental biofilm follows specific mechanisms of initial colonization on the surface, microcolony formation, development of organized three dimensional community structures, and detachment from the surface. The structure of the plaque biofilm might restrict the penetration of antimicrobial agents, while bacteria on a surface grow slowly and display a novel phenotype; the consequence of the latter is a reduced sensitivity to inhibitors. The aim of this study was to evaluate with different optoelectronic methods the morphological characteristics of the dental biofilm. The study was performed on samples from 25 patients aged between 18 and 35 years. The methods used in this study were Spectral Domain Optical Coherence Tomography (SD-OCT) working at 870 nm for in vivo evaluations and Scanning Electron Microscopy (SEM) for validations. For each patient a sample of dental biofilm was obtained directly from the vestibular surface of the teeth's. SD-OCT produced C- and B-scans that were used to generate three dimensional (3D) reconstructions of the sample. The results were compared with SEM evaluations. The biofilm network was dramatically destroyed after the professional dental cleaning. OCT noninvasive methods can act as a valuable tool for the 3D characterization of dental biofilms.

  5. Prolidase activity in chronic plaque psoriasis patients

    PubMed Central

    Aksoy, Nurten; Ozgöztas, Orhan; Sezen, Hatice; Yesilova, Yavuz; Turan, Enver

    2015-01-01

    Introduction Psoriasis is a chronic, inflammatory, T-cell-mediated and hyperproliferative skin disease characterized by erythematous, squamous, sharply circumscribed and infiltrated plaques. The metabolisms of the collagen proteins undergo considerable changes due to the acceleration of their turnovers as a result of increased prolidase activity in psoriasis patients. Aim To determine the level of prolidase activity in psoriasis patients and evaluate its relationship with the oxidative system. Material and methods The serum prolidase enzyme activity, total antioxidant levels and total oxidant levels of 40 psoriasis patients and a control group including 47 healthy individuals were analyzed by using their serum samples, and their oxidative stress indices were calculated. Results The prolidase levels (p < 0.01), total oxidant levels (p < 0.01) and oxidative stress index levels (p < 0.001) of the patient group were higher than the corresponding parameters in the control group. The total antioxidant level was low (p < 0.01). Although a positive correlation was found between the prolidase and total antioxidant levels and the total oxidant level, no correlation was found between prolidase and the oxidative stress index. Conclusions It has been determined that the activity of the prolidase enzyme increases due to the increased collage turnover in psoriasis patients. Increased serum oxidant levels and oxidative stress indices values may play a role in the pathogenesis of psoriasis. PMID:26015776

  6. Intravascular laser speckle imaging for the mechanical analysis of coronary plaques (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hosoda, Masaki; Wang, Jing; Tsikudi, Diane; Nadkarni, Seemantini

    2016-02-01

    Acute myocardial infarction is frequently caused by the rupture of coronary plaques with severely compromised viscoelastic properties. We have developed a new optical technology termed intravascular laser speckle imaging (ILSI) that evaluates plaque viscoelastic properties, by measuring the time scale (time constant, τ) of temporally evolving laser speckle fluctuations. To enable coronary evaluation in vivo, an optical ILSI catheter has been developed that accomplishes omni-directional illumination and viewing of the entire coronary circumference without the need for mechanical rotation. Here, we describe the capability of ILSI for evaluating human coronary atherosclerosis in cadaveric hearts. ILSI was conducted in conjunction with optical coherence tomography (OCT) imaging in five human cadaveric hearts. The left coronary artery (LCA), left anterior descending (LAD), left circumflex artery (LCx), and right coronary artery (RCA) segments were resected and secured on custom-developed coronary holders to enable accurate co-registration between ILSI, OCT, and histopathology. Speckle time constants, τ, calculated from each ILSI section were compared with lipid and collagen content measured from quantitative Histopathological analysis of the corresponding Oil Red O and Picrosirius Red stained sections. Because the presence of low viscosity lipid elicits rapid speckle fluctuations, we observed an inverse correlation between τ measured by ILSI and lipid content (R= -0.64, p< 0.05). In contrast, the higher viscoelastic modulus of fibrous regions resulted in a positive correlation between τ and collagen content (R= 0.54, p< 0.05). These results demonstrate the feasibility of conducting ILSI evaluation of arterial mechanical properties using a miniaturized omni-directional catheter.

  7. VIEW TO THE SOUTHEAST. MEMORIAL WITH BRONZE PLAQUE IN HONOR ...

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

    VIEW TO THE SOUTHEAST. MEMORIAL WITH BRONZE PLAQUE IN HONOR OF KELLER, MARKS THE CENTER OF THE BRIDGE. - Keller Memorial Bridge, Spanning Tennessee River at U.S. Highway 31, Decatur, Morgan County, AL

  8. 38. 100 foot through truss bridge original identification plaque ...

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

    38. 100 foot through truss - bridge original identification plaque located on the top of the north portal entrance. - Weidemeyer Bridge, Spanning Thomes Creek at Rawson Road, Corning, Tehama County, CA

  9. Clathrin and Cx43 gap junction plaque endoexocytosis

    SciTech Connect

    Nickel, Beth M.; DeFranco, B. Hewa; Gay, Vernon L.; Murray, Sandra A.

    2008-10-03

    In earlier transmission electron microscopic studies, we have described pentilaminar gap junctional membrane invaginations and annular gap junction vesicles coated with short, electron-dense bristles. The similarity between these electron-dense bristles and the material surrounding clathrin-coated pits led us to suggest that the dense bristles associated with gap junction structures might be clathrin. To confirm that clathrin is indeed associated with annular gap junction vesicles and gap junction plaques, quantum dot immuno-electron microscopic techniques were used. We report here that clathrin associates with both connexin 43 (Cx43) gap junction plaques and pentilaminar gap junction vesicles. An important finding was the preferential localization of clathrin to the cytoplasmic surface of the annular or of the gap junction plaque membrane of one of the two contacting cells. This is consistent with the possibility that the direction of gap junction plaque internalization into one of two contacting cells is regulated by clathrin.

  10. 13. SOUTHEAST OBELISK WITH PLAQUE COMMEMORATING CROSSING OF THE NORTH ...

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

    13. SOUTHEAST OBELISK WITH PLAQUE COMMEMORATING CROSSING OF THE NORTH ANNA RIVER BY ARMY OF NORTHERN VIRGINIA MAY 22, 1864; LOOKING EAST - Fox Bridge No. 1936, Spanning North Anna River at U.S. Route 1, Ashland, Hanover County, VA

  11. GETTYSBURG ADDRESS AND NATIONAL REGISTER PLAQUES, WITH HEADSTONES IN BACKGROUND. ...

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

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

  12. A helical microwave antenna for welding plaque during balloon angioplasty

    SciTech Connect

    Liu, P.; Rappaport, C.M.

    1996-10-01

    A catheter-based microwave helix antenna has been developed in an attempt to improve the long-term success of balloon angioplasty treatment of arteriosclerosis. When the balloon is inflated to widen vessels obstructed with plaque, microwave power is deposited in the plaque, heating it, and thereby fixing it in place. By optimizing the helix pitch angle and excitation frequency, the antenna radiation pattern can be adjusted to deposit microwave power preferentially in the plaque while avoiding overheating the healthy artery. The optimal power deposition patterns of helical antennas are analytically computed for four-layered concentric and four-layered nonconcentric cylindrical geometries, which model symmetric and asymmetric occluded arteries. Experiments were performed on occluded artery phantom models with a prototype antenna for both symmetric and asymmetric models, which matched the theoretical predictions well, indicating almost complete power absorption in the low-water-content simulated plaque.

  13. 32. STUDIO VIEW OF PLAQUE PLACED ON MILL HOUSE AT ...

    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

  14. 5. DETAIL VIEW, LOOKING WEST, SHOWING STONE PLAQUE INSCRIBED 'USRA, ...

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

    5. DETAIL VIEW, LOOKING WEST, SHOWING STONE PLAQUE INSCRIBED 'USRA, 1936' LOCATED IN EAST ELEVATION (tHIS PHOTOGRAPH IS FOGGED) - Spring Lake Bridge, Spanning Bob Barnes Branch at County Road No. 36D, Belleville, Yell County, AR

  15. Detail of aluminum plaque attached to the top of the ...

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

    Detail of aluminum plaque attached to the top of the northwest pilaster, facing west. - Oakland Avenue Viaduct, Oakland Avenue spanning U.S. Route 62 (State Route 2302) & Pine Run, Sharon, Mercer County, PA

  16. Limestone and bronze "Mississippi River Crossing" Bridge plaque located at ...

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

    Limestone and bronze "Mississippi River Crossing" Bridge plaque located at North corner of Administration Building site - Huey P. Long Bridge, Administration Building, 5100 Jefferson Highway, Jefferson, Jefferson Parish, LA

  17. 30. Bronze plaque located on southern inner wall at east ...

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

    30. Bronze plaque located on southern inner wall at east end of south pier taken looking southeast - Duluth Ship Canal, South Pier, North end of Minnesota Point & Canal Park, Duluth, St. Louis County, MN

  18. Plaque formation and marginal gingivitis associated with restorative materials.

    PubMed

    Litonjua, Luis A; Cabanilla, Leyvee L; Abbott, Lawrence J

    2011-05-01

    The presence of restorative materials on tooth surfaces is perceived to be a contributing factor to periodontal disease. This observation is a result of the increased accumulation of plaque on restorations adjacent to the gingiva, which may lead to gingivitis. Plaque is believed to adhere better to restorations than to enamel. This may be due to the surface characteristics of restorative materials such as surface roughness and surface-free energy inherent in the materials. This article reviews the experimental studies of plaque formation on different restorative materials. In addition, clinical studies analyzing and comparing restorative materials and the consequent formation of gingivitis are reviewed. While in vitro and in vivo studies show variations in plaque formation among restorative materials and enamel, clinical studies demonstrate that the progression of gingivitis can be prevented if patients maintain adequate oral hygiene and home care. Therefore, instructing the patient to maintain proper oral hygiene and home care is more important than the choice of restorative material.

  19. Plaque formation and marginal gingivitis associated with restorative materials.

    PubMed

    Litonjua, Luis A; Cabanilla, Leyvee L; Abbott, Lawrence J

    2012-01-01

    The presence of restorative materials on tooth surfaces is perceived to be a contributing factor to periodontal disease. This observation is a result of the increased accumulation of plaque on restorations adjacent to the gingiva, which may lead to gingivitis. Plaque is believed to adhere better to restorations than to enamel. This may be due to the surface characteristics of restorative materials such as surface roughness and surface-free energy inherent in the materials. This article reviews the experimental studies of plaque formation on different restorative materials. In addition, clinical studies analyzing and comparing restorative materials and the consequent formation of gingivitis are reviewed. While in vitro and in vivo studies show variations in plaque formation among restorative materials and enamel, clinical studies demonstrate that the progression of gingivitis can be prevented if patients maintain adequate oral hygiene and home care. Therefore, instructing the patient to maintain proper oral hygiene and home care is more important than the choice of restorative material.

  20. 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

  1. A patient with plaque type morphea mimicking systemic lupus erythematosus.

    PubMed

    Wardhana; Datau, E A

    2015-04-01

    Morphea is an uncommon connective tissue disease with the most prominent feature being thickening or fibrosis of the dermal without internal organ involvement. It is also known as a part of localized scleroderma. Based on clinical presentation and depth of tissue involvement, morphea is classified into several forms, and about two thirds of adults with morphea have plaque type. Overproduction of collagen production by fibroblast is the cause of abnormality in morphea, and the hyperactivity mechanism of fibroblast is still unknown, although there are several mechanisms already proposed. Plaque type morphea is actually a benign and self limited. Plaque type morphea that mimicking systemic lupus erythematosus in clinical appearance, such as alopecia and oral mucosal ulcers, is uncommon. A case of plaque type morphea mimicking systemic lupus erythematosus in a 20 year old woman was discussed. The patient was treated with local and systemic immunosuppressant and antioxydant. The patient's condition is improved without any significant side effects.

  2. 6. VIEW OF COMMEMORATIVE PLAQUE, EAST APPROACH GUARDRAIL, WHICH STATES ...

    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

  3. The Inclusion of Arbitrary Load Histories in the Strength Decay Model for Stress Rupture

    NASA Technical Reports Server (NTRS)

    Reeder, James R.

    2014-01-01

    Stress rupture is a failure mechanism where failures can occur after a period of time, even though the material has seen no increase in load. Carbon/epoxy composite materials have demonstrated the stress rupture failure mechanism. In a previous work, a model was proposed for stress rupture of composite overwrap pressure vessels (COPVs) and similar composite structures based on strength degradation. However, the original model was limited to constant load periods (holds) at constant load. The model was expanded in this paper to address arbitrary loading histories and specifically the inclusions of ramp loadings up to holds and back down. The broadening of the model allows for failures on loading to be treated as any other failure that may occur during testing instead of having to be treated as a special case. The inclusion of ramps can also influence the length of the "safe period" following proof loading that was previously predicted by the model. No stress rupture failures are predicted in a safe period because time is required for strength to decay from above the proof level to the lower level of loading. Although the model can predict failures during the ramp periods, no closed-form solution for the failure times could be derived. Therefore, two suggested solution techniques were proposed. Finally, the model was used to design an experiment that could detect the difference between the strength decay model and a commonly used model for stress rupture. Although these types of models are necessary to help guide experiments for stress rupture, only experimental evidence will determine how well the model may predict actual material response. If the model can be shown to be accurate, current proof loading requirements may result in predicted safe periods as long as 10(13) years. COPVs design requirements for stress rupture may then be relaxed, allowing more efficient designs, while still maintaining an acceptable level of safety.

  4. 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

  5. Plaque retention on elastomeric ligatures. An in vivo study

    PubMed Central

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

    2013-01-01

    SUMMARY Fixed orthodontic appliances make it difficult to maintain the oral hygiene, resulting in plaque accumulation. Retention of bacterial plaque, represents a risk for white spot lesions and development of periodontal disease. Aim Purpose of this study was to determine in vivo the retention of plaque on three different elastic ligatures, in comparison with stainless steel ligature, to determine a possible association between type of ligatures and accumulation of microorganisms. Material and Methods three elastic ligation systems were analyzed for plaque retention: ring-shape, clear, latex ligatures (Leone® Spa), ring-shape, grey, polyurethane ligatures (Micerium® Spa) and grey, polyurethane, Slide low-friction ligatures (Leone® Spa), compared with stainless steel ligatures (Leone® Spa) used as control. Forthy orthodontic patients undergoing fixed orthodontic therapy were selected. A sample for each type of ligature were applied inside the oral cavity of each subject. Samples were kept in the oral cavity for 28 days, ligating 0.16 X 0.22 stainless steel archwire to stainless steel orthodontic premolars brackets. The presence of bacterical slime was quantified by spectrophotometric method (crystal violet-Bouin’s fixative) and morphological observations was evaluated by Scanning Electron Microscopy (SEM). Results From analysis of bacterical slime emerges that all the elastics showed a low plaque retention, especially if compared to the group of steinless steel ligatures, that presented a greater plaque adhesion, statistically significant compared to the Slide group (r<0.0002) and the two elastic groups (r<0.0001). This study reported no significant difference between the Slide ligatures and the traditional elastic ligatures as regards the retention of plaque. SEM images showed presence of cocci, rods and few filamentous organisms and an interbacterial matrix in all observed samples. Conclusion Elastomeric ligatures showed a significant lower susceptibility

  6. Urease and Dental Plaque Microbial Profiles in Children

    PubMed Central

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

    2015-01-01

    Objective Urease enzymes produced by oral bacteria generate ammonia, which can have a significant impact on the oral ecology and, consequently, on oral health. To evaluate the relationship of urease with dental plaque microbial profiles in children as it relates to dental caries, and to identify the main contributors to this activity. Methods 82 supragingival plaque samples were collected from 44 children at baseline and one year later, as part of a longitudinal study on urease and caries in children. DNA was extracted; the V3–V5 region of the 16S rRNA gene was amplified and sequenced using 454 pyrosequencing. Urease activity was measured using a spectrophotometric assay. Data were analyzed with Qiime. Results Plaque urease activity was significantly associated with the composition of the microbial communities of the dental plaque (Baseline P = 0.027, One Year P = 0.012). The bacterial taxa whose proportion in dental plaque exhibited significant variation by plaque urease levels in both visits were the family Pasteurellaceae (Baseline P<0.001; One Year P = 0.0148), especially Haemophilus parainfluenzae. No association was observed between these bacteria and dental caries. Bacteria in the genus Leptotrichia were negatively associated with urease and positively associated with dental caries (Bonferroni P<0.001). Conclusions Alkali production by urease enzymes primarily from species in the family Pasteurellaceae can be an important ecological determinant in children’s dental plaque. Further studies are needed to establish the role of urease-associated bacteria in the acid/base homeostasis of the dental plaque, and in the development and prediction of dental caries in children. PMID:26418220

  7. Captured Macro-embolus of Fractured Atheromatous Plaque by the Embolic Protection Device during Carotid Stent Assisted Angioplasty.

    PubMed

    Kim, Mun Chul; Bennett, Shelby; Farb, Richard; Croul, Sydney; Lee, Seon-Kyu

    2013-02-01

    The authors present a case in which macro-embolus from the ruptured atheromatous plaque developed during carotid artery stenting (CAS). A 63-year-old man who had suffered a left middle cerebral artery territory infarction had significant proximal left internal carotid artery stenosis required CAS procedure. Immediate after stent deployment, the patient showed abrupt neurological deterioration with 12 × 3 mm sized macro-embolus which was caught by the embolus protection device (EPD). Retrieval of the macro-embolus was performed safely and the patient recovered to pre-procedure status. Macro-embolus can be resulted during the CAS. The EPD can capture the macro-embolus and safe removal is technically feasible.

  8. Star polymers rupture induced by constant forces.

    PubMed

    García, N A; Febbo, M; Vega, D A; Milchev, A

    2014-10-28

    In this work, we study the breakage process of an unknotted three-arm star-shaped polymer when it is pulled from its free ends by a constant force. The star polymer configuration is described through an array of monomers coupled by anharmonic bonds, while the rupture process is tracked in three-dimensional space by means of Langevin Molecular Dynamics simulations. The interaction between monomers is described by a Morse potential, while a Weeks-Chandler-Anderson energetic contribution accounts for the excluded volume interaction. We explore the effect of the molecular architecture on the distributions of rupture times over a broad interval of pulling forces and star configurations. It was found that the rupture time distribution of the individual star arms is strongly affected by the star configuration imposed by the pulling forces and the length of the arms. We also observed that for large pulling forces the rupture time distributions resemble the dominant features observed for linear polymer chains. The model introduced here provides the basic ingredients to describe the effects of tensile forces on stress-induced degradation of branched macromolecules and polymer networks.

  9. Plantar fascia rupture associated with corticosteroid injection.

    PubMed

    Sellman, J R

    1994-07-01

    A series of 37 patients, all with a presumptive diagnosis of plantar fascia rupture, is presented. All had had prior heel pain diagnosed as plantar fasciitis, and all had been treated with corticosteroid injection into the calcaneal origin of the fascia. One third described a sudden tearing episode in the heel, while the rest had a gradual change in symptoms. Most of the patients had relief of the original heel pain, which had been replaced by a variety of new foot problems, including dorsal and lateral midfoot pain, swelling, foot weakness, metatarsal pain, and metatarsal fracture. In all 37 patients, there was a palpable diminution in the tension of the plantar fascia on the involved side, and footprints often showed a flattening of the involved arch. Magnetic resonance imaging done on one patient showed attenuation of the plantar fascia. From these observations and data, the author concluded that plantar fascia rupture had occurred. Treatment following rupture included supportive shoes, orthoses, and time. The majority had resolution of their new symptoms, but this often took 6 to 12 months to occur. In the remainder, there were persisting symptoms. Corticosteroid injections, although helpful in the treatment of plantar fasciitis, appear to predispose to plantar fascia rupture.

  10. Musculotendinous infraspinatus rupture and shoulder weakness.

    PubMed

    Lipford, Melissa C; Bond, Jeffrey R; Steinmann, Scott P; Kumar, Neeraj

    2011-12-01

    We report a patient with bilateral simultaneous onset of weakness of shoulder lateral rotation due to musculotendinous infraspinatus rupture that occurred after shoulder steroid injections. Disruption of the musculotendinous junction of the infraspinatus is a rare recently described entity. Electromyography is normal, and magnetic resonance image findings are characteristic.

  11. Bond-rupture immunosensors--a review.

    PubMed

    Hirst, Evan R; Yuan, Yong J; Xu, W L; Bronlund, J E

    2008-07-15

    It has long been the goal of researchers to develop fast and reliable point-of-care alternatives to existing lab-based tests. A viable point-of-care biosensor is fast, reliable, simple, cost-effective, and detects low concentrations of the target analyte. The target of biosensors is biological such as bacteria or virus and as such, the antibody-antigen bond derived from the real immune response is used. Biosensor applications include lab-based tests for the purposes of diagnostics, drug discovery, and research. Additional applications include environmental, food, and agricultural monitoring. The main merits of the bond-rupture method are quick, simple, and capable of discriminating between specific and non-specific interactions. The separation of specific and non-specific bonds is important for working in real-life complex serums such as blood. The bond-rupture technique can provide both qualitative results, the detection of a target, and quantitative results, the concentration of target. Bond-rupture achieves this by a label-free method requiring no pre-processing of the analyte. A piezoelectric transducer such as the quartz crystal microbalance (QCM) shakes the bound particles free from the surface. Other transducers such as Surface Acoustic Wave (SAW) are also considered. The rupture of the bonds is detected as electronic noise. This review article links diverse research areas to build a picture of a field still in development.

  12. [Is dental plaque a normal Helicobacter pylori reservoir?].

    PubMed

    Améndola, R; Roldán, C D; Morgade, L; Solagna, A; Lineado, A; Musi, A O; Valero, J; Zerbo, O; Kogan, Z; Ferro, F E; Schenone, L; Corti, R

    1998-01-01

    The mechanisms of transmission and reservoir of Helicobacter pylori is still unclear; even it has been suggested that dental plaque could be the bacterial reservoir and one important factor in the reinfection. The aim of the study was to evaluate the prevalence of Helicobacter pylori in dental plaque in 20 patients with non ulcer dyspepsia (12 females, 7 males; mean age 40.5 years) and antral infection; and to establish the presence of bacteria in dental plaque and gastric mucosa after eradication. Gastric colonization in all of them was confirmed by five samples (three of antrum and two of body) with Giemsa conventional technique, clotest and culture. When clotest was positive in gastric mucosa, we performed the scrape of dental plaque and sending the material for culture. All patients were treated with a scheme of seven days with one protom pump inhibitor and two antibiotics. After four weeks all the patients were controlled with endoscopy and culture of dental plaque to confirm eradication. Dental plaque culture was positive in 1/20 patients (5%), and this results was similar to developed countries, using as detection method culture or polymerase chain reaction (PCR).

  13. THE TRANSCRIPTIONAL SIGNATURES OF CELLS FROM THE HUMAN PEYRONIE'S DISEASE PLAQUE AND THE ABILITY OF THESE CELLS TO GENERATE A PLAQUE IN A RAT MODEL SUGGEST POTENTIAL THERAPEUTIC TARGETS

    PubMed Central

    Gelfand, R; Vernet, D; Kovanecz, I; Rajfer, J; Gonzalez-Cadavid, NF

    2015-01-01

    Introduction The success of medical therapies for Peyronie's disease (PD) has not been optimal, possibly because many of them went directly to clinical application without sufficient preclinical scientific research. Previous studies revealed cellular and molecular pathways involved in the formation of the PD plaque, and in particular the role of the myofibroblast. Aims The current work aimed to determine under normal and fibrotic conditions what differentiates PD cells from tunica albuginea (TA) and corpora cavernosa (CC) cells, by defining their global transcriptional signatures and testing in vivo whether PD cells can generate a PD like plaque Main Outcomes Measures Fibroproliferative features of PD cells and identification of related key genes as novel targets to reduce plaque size Methods Human TA, PD, and CC cells were grown with TGFβ1 (TA+, PD+, CC+) or without it (TA−, PD−, CC−) and assayed by: a) immunofluorescence, western blot and RT/PCR for myofibroblast, smooth muscle cell and stem cell markers; b) collagen content; and c) DNA microarray analysis. The ability of PD+ cells to induce a PD like plaque in an immuno-suppressed rat model was assessed by Masson trichrome and Picrosirius Red. Results Upon TGFβ1stimulation, collagen levels were increased by myofibroblasts in the PD+ but not in the CC+ cells. The transcriptional signature of the PD− cells identified fibroproliferative, myogenic (myofibroblasts), inflammatory, and collagen turnover genes, that differentiate them from TA− or CC− cells, and respond to TGFβ1 with a PD+ fibrotic phenotype, by upregulation of IGF1, ACTG2, MYF5, ACTC1, PSTN, COL III, MMP3, and others. The PD+ cells injected into the TA of the rat induce a PD like plaque. Conclusions This suggests a novel combination therapy to eliminate a PD plaque, by targeting the identified genes to: a) improve collagenase action by stimulating endogenous MMPs specific to key collagen types, and b) counteract fibromatosis by inhibiting

  14. Premature rupture of the fetal membranes. An update for advanced practice nurses.

    PubMed

    Weitz, B W

    2001-01-01

    Advanced practice nurses in obstetric settings are frequently required to diagnose premature rupture of fetal membranes; co-management of care with physicians is becoming more common in many health care facilities. Therefore, Advanced practice nurses must have an in-depth understanding of this potentially severe obstetric complication. This article presents a review of the current literature focusing on the epidemiology, physiology, pathophysiology, prevention measures, subjective and objective assessment, diagnostic tests, and management of premature rupture of membranes. Psychosocial aspects of this event, often upsetting for the family, are also discussed.

  15. [Surgical treatment of rupture of the plantar fascia].

    PubMed

    Christel, P; Rigal, S; Poux, D; Roger, B; Witvoët, J

    1993-01-01

    Among the various lesions of the hindfoot in athletes, plantar fascia ruptures are not well documented and their surgical treatment is not often reported in the literature. The purpose of the current work was to more precisely define therapeutic indications and to evaluate the results of the surgical treatment based on the excision-release of the plantar fascia. Between 1986 and 1991, 19 patients (5 females, 14 males, average age 32 years) were operated on by one surgeon. All patients were either recreational or competitive athletes. The plantar fascia rupture occurred 18 times during sports activity. Surgical treatment was indicated when pain persisted despite a well conducted conservative treatment. In 17 cases, MRI allowed to plan the operative strategy by showing the fascia lesion. The patients were operated after an average of 8 months following the initial injury (6-16 months). One patient was lost for follow-up, 2 had a follow-up below 6 months, thus 16 patients were available for analysis. The clinical outcome was evaluated through persistence of pain, return to sports, and functional activity. With a 16-month average follow-up (6-51 months) it was observed that pain constantly disappeared and that 11 patients over 16 returned to the same level of sports activity after 6 months with a time-stable result. After failure of a well conducted conservative treatment, surgical treatment of plantar fascia rupture must be proposed. Surgical technique is based not only on fascia release but also on the excision of the pathological scar tissue in order to avoid the restoration of the continuity of the fascia with the calcaneus.

  16. Radiobiology for eye plaque brachytherapy and evaluation of implant duration and radionuclide choice using an objective function

    SciTech Connect

    Gagne, Nolan L.; Leonard, Kara L.; Rivard, Mark J.

    2012-06-15

    Purpose: Clinical optimization of Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy is currently limited to tumor coverage, consensus prescription dosage, and dose calculations to ocular structures. The biologically effective dose (BED) of temporary brachytherapy treatments is a function of both chosen radionuclide R and implant duration T. This study endeavored to evaluate BED delivered to the tumor volume and surrounding ocular structures as a function of plaque position P, prescription dose, R, and T. Methods: Plaque-heterogeneity-corrected dose distributions were generated with MCNP5 for the range of currently available COMS plaques loaded with sources using three available low-energy radionuclides. These physical dose distributions were imported into the PINNACLE{sup 3} treatment planning system using the TG-43 hybrid technique and used to generate dose volume histograms for a T = 7 day implant within a reference eye geometry including the ciliary body, cornea, eyelid, foveola, lacrimal gland, lens, optic disc, optic nerve, retina, and tumor at eight standard treatment positions. The equation of Dale and Jones was employed to create biologically effective dose volume histograms (BEDVHs), allowing for BED volumetric analysis of all ROIs. Isobiologically effective prescription doses were calculated for T = 5 days down to 0.01 days, with BEDVHs subsequently generated for all ROIs using correspondingly reduced prescription doses. Objective functions were created to evaluate the BEDVHs as a function of R and T. These objective functions are mathematically accessible and sufficiently general to be applied to temporary or permanent brachytherapy implants for a variety of disease sites. Results: Reducing T from 7 to 0.01 days for a 10 mm plaque produced an average BED benefit of 26%, 20%, and 17% for {sup 103}Pd, {sup 125}I, and {sup 131}Cs, respectively, for all P; 16 and 22 mm plaque results were more position-dependent. {sup 103}Pd produced a 16

  17. Methodology for fully automated segmentation and plaque characterization in intracoronary optical coherence tomography images.

    PubMed

    Athanasiou, Lambros S; Bourantas, Christos V; Rigas, George; Sakellarios, Antonis I; Exarchos, Themis P; Siogkas, Panagiotis K; Ricciardi, Andrea; Naka, Katerina K; Papafaklis, Michail I; Michalis, Lampros K; Prati, Francesco; Fotiadis, Dimitrios I

    2014-02-01

    Optical coherence tomography (OCT) is a light-based intracoronary imaging modality that provides high-resolution cross-sectional images of the luminal and plaque morphology. Currently, the segmentation of OCT images and identification of the composition of plaque are mainly performed manually by expert observers. However, this process is laborious and time consuming and its accuracy relies on the expertise of the observer. To address these limitations, we present a methodology that is able to process the OCT data in a fully automated fashion. The proposed methodology is able to detect the lumen borders in the OCT frames, identify the plaque region, and detect four tissue types: calcium (CA), lipid tissue (LT), fibrous tissue (FT), and mixed tissue (MT). The efficiency of the developed methodology was evaluated using annotations from 27 OCT pullbacks acquired from 22 patients. High Pearson's correlation coefficients were obtained between the output of the developed methodology and the manual annotations (from 0.96 to 0.99), while no significant bias with good limits of agreement was shown in the Bland-Altman analysis. The overlapping areas ratio between experts' annotations and methodology in detecting CA, LT, FT, and MT was 0.81, 0.71, 0.87, and 0.81, respectively.

  18. Elevated Uptake of Plasma Macromolecules by Regions of Arterial Wall Predisposed to Plaque Instability in a Mouse Model

    PubMed Central

    Mohri, Zahra; Rowland, Ethan M.; Clarke, Lindsey A.; De Luca, Amalia; Peiffer, Véronique; Krams, Rob; Sherwin, Spencer J.; Weinberg, Peter D.

    2014-01-01

    Atherosclerosis may be triggered by an elevated net transport of lipid-carrying macromolecules from plasma into the arterial wall. We hypothesised that whether lesions are of the thin-cap fibroatheroma (TCFA) type or are less fatty and more fibrous depends on the degree of elevation of transport, with greater uptake leading to the former. We further hypothesised that the degree of elevation can depend on haemodynamic wall shear stress characteristics and nitric oxide synthesis. Placing a tapered cuff around the carotid artery of apolipoprotein E -/- mice modifies patterns of shear stress and eNOS expression, and triggers lesion development at the upstream and downstream cuff margins; upstream but not downstream lesions resemble the TCFA. We measured wall uptake of a macromolecular tracer in the carotid artery of C57bl/6 mice after cuff placement. Uptake was elevated in the regions that develop lesions in hyperlipidaemic mice and was significantly more elevated where plaques of the TCFA type develop. Computational simulations and effects of reversing the cuff orientation indicated a role for solid as well as fluid mechanical stresses. Inhibiting NO synthesis abolished the difference in uptake between the upstream and downstream sites. The data support the hypothesis that excessively elevated wall uptake of plasma macromolecules initiates the development of the TCFA, suggest that such uptake can result from solid and fluid mechanical stresses, and are consistent with a role for NO synthesis. Modification of wall transport properties might form the basis of novel methods for reducing plaque rupture. PMID:25531765

  19. The role of marine omega-3 (n-3) fatty acids in inflammatory processes, atherosclerosis and plaque stability.

    PubMed

    Calder, Philip C

    2012-07-01

    Atherosclerosis has an important inflammatory component and acute cardiovascular events can be initiated by inflammatory processes occurring in advanced plaques. Fatty acids influence inflammation through a variety of mechanisms; many of these are mediated by, or associated with, the fatty acid composition of cell membranes. Human inflammatory cells are typically rich in the n-6 fatty acid arachidonic acid, but the contents of arachidonic acid and of the marine n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can be altered through oral administration of EPA and DHA. Eicosanoids produced from arachidonic acid have roles in inflammation. EPA also gives rise to eicosanoids and these are usually biologically weak. EPA and DHA give rise to resolvins which are anti-inflammatory and inflammation resolving. EPA and DHA also affect production of peptide mediators of inflammation (adhesion molecules, cytokines, etc.). Thus, the fatty acid composition of human inflammatory cells influences their function; the contents of arachidonic acid, EPA and DHA appear to be especially important. The anti-inflammatory effects of marine n-3 polyunsaturated fatty acids (PUFAs) may contribute to their protective actions towards atherosclerosis and plaque rupture.

  20. Isolated Total Rupture of Extraocular Muscles

    PubMed Central

    Chen, Jingchang; Kang, Ying; Deng, Daming; Shen, Tao; Yan, Jianhua

    2015-01-01

    Abstract Total rupture of extraocular muscles is an infrequent clinical finding. Here we conducted this retrospective study to evaluate their causes of injury, clinical features, imaging, surgical management, and final outcomes in cases of isolated extraocular muscle rupture at a tertiary center in China. Thirty-six patients were identified (24 men and 12 women). Mean age was 34 years (range 2–60). The right eye was involved in 21 patients and the left 1 in 15. A sharp object or metal hook was the cause of this lesion in 16 patients, sinus surgery in 14 patients, traffic accident in 3 patients, orbital surgery in 2 patients, and conjunctive tumor surgery in 1 patient. The most commonly involved muscles were medial (18 patients) and inferior rectus muscles (13 patients). The function of the ruptured muscles revealed a scale of −3 to −4 defect of ocular motility and the amount of deviation in primary position varied from 10 to 140 PD (prism diopter). Computerized tomography (CT) confirmed the presence of ruptured muscles. An end-to-end muscle anastomosis was performed and 3 to 5 mm of muscle was resected in 23 patients. When the posterior border of the injured muscle could not be identified (13 patients), a partial tendon transposition was performed, together with recession of the antagonist in most patients, whereas a recession of the antagonist muscle plus a resection of the involved muscle with or without nasal periosteal fixation was performed in the remaining patients. After an average of 16.42 months of follow-up an excellent result was achieved in 23 patients and results of 13 patients were considered as a failure. In most patients, the posterior border of the ruptured muscle can be identified and an early surgery can be performed to restore function. Alternatively, a partial tendon transposition should be performed. When muscular rupture is suspected, an early orbital CT is required to confirm this possibility, which can then verify the necessity for

  1. Fiber Breakage Model for Carbon Composite Stress Rupture Phenomenon: Theoretical Development and Applications

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.; Phoenix, S. Leigh; Grimes-Ledesma, Lorie

    2010-01-01

    Stress rupture failure of Carbon Composite Overwrapped Pressure Vessels (COPVs) is of serious concern to Science Mission and Constellation programs since there are a number of COPVs on board space vehicles with stored gases under high pressure for long durations of time. It has become customary to establish the reliability of these vessels using the so called classic models. The classical models are based on Weibull statistics fitted to observed stress rupture data. These stochastic models cannot account for any additional damage due to the complex pressure-time histories characteristic of COPVs being supplied for NASA missions. In particular, it is suspected that the effects of proof test could significantly reduce the stress rupture lifetime of COPVs. The focus of this paper is to present an analytical appraisal of a model that incorporates damage due to proof test. The model examined in the current paper is based on physical mechanisms such as micromechanics based load sharing concepts coupled with creep rupture and Weibull statistics. For example, the classic model cannot accommodate for damage due to proof testing which every flight vessel undergoes. The paper compares current model to the classic model with a number of examples. In addition, several applications of the model to current ISS and Constellation program issues are also examined.

  2. Monocyte prostaglandins inhibit procollagen secretion by human vascular smooth muscle cells: implications for plaque stability.

    PubMed

    Fitzsimmons, C; Proudfoot, D; Bowyer, D E

    1999-02-01

    Extracellular matrix remodelling occurs during atherosclerosis dictating the structure of the plaque and thus the resistance to rupture. Monocytes and macrophages are believed to play a role in this remodelling. In the present study, filter-separated co-culture has been used to study the effect of monocytes on procollagen turnover by human vascular smooth muscle cells (VSMC). In this system, freshly isolated human peripheral blood monocytes inhibited procollagen secretion from VSMC without affecting either degradation of procollagen, or DNA synthesis by the VSMC. Insertion of a 12 kDa dialysis membrane between the two cell types and treatment with indomethacin showed that the inhibitory factor was of low molecular weight and was cyclooxygenase-dependent. Pre-incubation of each cell type with indomethacin demonstrated that monocyte, but not VSMC cyclooxygenase was required. Thus, the inhibitory effect on procollagen secretion was due, most likely, to monocyte prostaglandins. Neither inhibition of thromboxane synthetase, nor blocking IL-1 activity, reduced the inhibitory activity. Addition of prostaglandins PGE1, PGE2 and PGF2alpha to VSMC cultures caused a reduction in procollagen secretion which was equivalent to, but was not additive with, the maximal effect achieved by monocytes. Monocytes and macrophages are a major source of prostaglandins and these molecules are likely to play an important role in collagen turnover within lesions.

  3. Rupture Process During the 2015 Illapel, Chile Earthquake: Zigzag-Along-Dip Rupture Episodes

    NASA Astrophysics Data System (ADS)

    Okuwaki, Ryo; Yagi, Yuji; Aránguiz, Rafael; González, Juan; González, Gabriel

    2016-04-01

    We constructed a seismic source model for the 2015 M W 8.3 Illapel, Chile earthquake, which was carried out with the kinematic waveform inversion method adopting a novel inversion formulation that takes into account the uncertainty in the Green's function, together with the hybrid backprojection method enabling us to track the spatiotemporal distribution of high-frequency (0.3-2.0 Hz) sources at high resolution by using globally observed teleseismic P-waveforms. A maximum slip amounted to 10.4 m in the shallow part of the seismic source region centered 72 km northwest of the epicenter and generated a following tsunami inundated along the coast. In a gross sense, the rupture front propagated almost unilaterally to northward from the hypocenter at <2 km/s, however, in detail the spatiotemporal slip distribution also showed a complex rupture propagation pattern: two up-dip rupture propagation episodes, and a secondary rupture episode may have been triggered by the strong high-frequency radiation event at the down-dip edge of the seismic source region. High-frequency sources tends to be distributed at deeper parts of the slip area, a pattern also documented in other subduction zone megathrust earthquakes that may reflect the heterogeneous distribution of fracture energy or stress drop along the fault. The weak excitation of high-frequency radiation at the termination of rupture may represent the gradual deceleration of rupture velocity at the transition zone of frictional property or stress state between the megathrust rupture zone and the swarm area.

  4. Detection of supershear rupture in 2013 Craig, Alaska, earthquake

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-01-01

    Seismic ruptures are akin to opening a zipper—a gap in the crust starts in one location and travels along the fault in a particular direction. When a strained fault ruptures in an earthquake, seismic waves also spread out from the epicenter. In some cases, the waves' passage can trigger the initiation of a new rupture ahead of the initial expanding rupture in locked portions of the fault. If the triggered rupture grows successfully, the overall rupture front can then outpace the passage of the shear waves, secondary seismic waves that travel slowly after the earthquake begins and are responsible for the bulk of violent shaking. These earthquakes display what is known as supershear rupture; only seven such earthquakes have previously been recorded.

  5. [Proximal and distal rupture of the m. biceps brachii].

    PubMed

    Lorbach, O; Kieb, M; Grim, C; Engelhardt, M

    2010-12-01

    Ruptures of the biceps tendon account for a high percentage of tendon ruptures. The aetiology of proximal ruptures of the long head of the biceps tendon is often degenerative and they are frequently associated with lesions of the rotator cuff. The clinical findings are often not specific and long lasting. Distal ruptures of the biceps tendon mostly occur during eccentric contraction of the biceps muscle.Clinical tests, the associated haematoma and a distalisation or proximalisation of the muscle belly in combination with ultrasound or MRI to rule out combined diseases lead to the diagnosis. The possible options include conservative and operative treatment. Tenotomy and tenodesis lead to comparable results in the literature. Therefore, conservative treatment is mostly recommended in proximal ruptures. Operative treatment is preferred in distal ruptures of the biceps tendon in order to achieve an anatomical reconstruction of the muscle function. Chronic ruptures of the distal biceps tendon can be successfully treated with free autografts or allografts.

  6. Blunt Cardiac Rupture: A Diagnostic Challenge

    PubMed Central

    Kumar, Vineet; Dharap, Satish Balkrishna

    2016-01-01

    Blunt Cardiac Rupture (BCR) is a life threatening injury. Majority of patients do not reach the hospital and in those who reach the emergency department, timely diagnosis and treatment is a challenge. The case is about a patient with multiple blunt injuries who presented in shock. Cardiac tamponade was suspected on clinical grounds and on evidence of mediastinal widening on radiograph. In the absence of songography, the diagnosis was confirmed by subxiphoid pericardial window. Emergency thoracotomy revealed a right atrial appendage rupture which was surgically corrected. The patient also underwent splenectomy for grade IV splenic injury. Liver injury, pubic diastasis and tibial spine avulsion fracture was managed conservatively. He recovered well. Systematic observance of trauma resuscitation guidelines can help salvage patients with life threatening complex injuries even in the absence of specialized imaging investigations. PMID:28050441

  7. Liquid salt environment stress-rupture testing

    DOEpatents

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  8. Creep rupture behavior of Stirling engine materials

    NASA Technical Reports Server (NTRS)

    Titran, R. H.; Scheuerman, C. M.; Stephens, J. R.

    1985-01-01

    The automotive Stirling engine, being investigated jointly by the Department of Energy and NASA Lewis as an alternate to the internal combustion engine, uses high-pressure hydrogen as the working fluid. The long-term effects of hydrogen on the high temperature strength properties of materials is relatively unknown. This is especially true for the newly developed low-cost iron base alloy NASAUT 4G-A1. This iron-base alloy when tested in air has creep-rupture strengths in the directionally solidified condition comparable to the cobalt base alloy HS-31. The equiaxed (investment cast) NASAUT 4G-A1 has superior creep-rupture to the equiaxed iron-base alloy XF-818 both in air and 15 MPa hydrogen.

  9. Rupture rudimentary horn pregnancy at 31 week

    PubMed Central

    Al Qarni, Abdullah A.; Al-Braikan, Nawal; Al-Hanbali, Moh’d M.; Alharmaly, Abdullah H.

    2017-01-01

    Rudimentary horn could be a rare congenital uterine anomalies result from incomplete fusion of the 2 Müllerian ducts throughout embryo-genesis. Pregnancy in an exceedingly rudimentary horn is rare and typically terminates in rupture throughout the late of first or second trimester of pregnancy. We tend to present a rare case of a gravida within the trimester (31 weeks) presented with complain of abdominal pain, nausea, and vomit for 3 days. On presentation, the patient was pale and irritable. Ultrasound scan showed fetus at (30 weeks) with cardiac activity. Cardiotocography reactive. Incision showed horned uterus with pregnancy in rudimentary left horn that was ruptured. Alive fetus was delivered. The rudimentary left horn was excised. The patient was advised to not get pregnant for 3 years. Within one year, the patient came to hospital in active labor at (37 weeks). This case emphasizes the importance of fine antepartum care to avoid morbidity and mortality. PMID:28133695

  10. Rupture rudimentary horn pregnancy at 31 week.

    PubMed

    Al Qarni, Abdullah A; Al-Braikan, Nawal; Al-Hanbali, Moh'd M; Alharmaly, Abdullah H

    2017-02-01

    Rudimentary horn could be a rare congenital uterine anomalies result from incomplete fusion of the two Müllerian ducts throughout embryo-genesis. Pregnancy in an exceedingly rudimentary horn is rare and typically terminates in rupture throughout the late of first or second trimester of pregnancy. We tend to present a rare case of a gravida within the trimester (31 weeks) presented with complain of abdominal pain, nausea, and vomit for 3 days. On presentation, the patient was pale and irritable. Ultrasound scan showed fetus at (30 weeks) with cardiac activity. Cardiotocography reactive. Incision showed horned uterus with pregnancy in rudimentary left horn that was ruptured. Alive fetus was delivered. The rudimentary left horn was excised. The patient was advised to not get pregnant for 3 years. Within one year, the patient came to hospital in active labor at (37 weeks). This case emphasizes the importance of fine antepartum care to avoid morbidity and mortality.

  11. Brittle dynamic damage due to earthquake rupture

    NASA Astrophysics Data System (ADS)

    Bhat, Harsha; Thomas, Marion

    2016-04-01

    The micromechanical damage mechanics formulated by Ashby and Sammis, 1990, and generalized by Deshpande and Evans 2008 has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated new crack growth (damage evolution) law that is valid over a wide range of loading rates. This law is sensitive to both the crack tip stress field and its time derivative. Incorporating this feature produces additional strain-rate sensitivity in the constitutive response. The model is also experimentally verified by predicting the failure strength of Dionysus-Pentelicon marble over wide range of strain rates. We then implement this constitutive response to understand the role of dynamic brittle off-fault damage on earthquake ruptures. We show that off-fault damage plays an important role in asymmetry of rupture propagation and is a source of high-frequency ground motion in the near source region.

  12. Low copper and high manganese levels in prion protein plaques

    USGS Publications Warehouse

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

    2013-01-01

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

  13. Uniaxial tensile testing approaches for characterisation of atherosclerotic plaques.

    PubMed

    Walsh, M T; Cunnane, E M; Mulvihill, J J; Akyildiz, A C; Gijsen, F J H; Holzapfel, G A

    2014-03-03

    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.

  14. Antiinflammatory actions of inorganic nitrate stabilize the atherosclerotic plaque

    PubMed Central

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

    2017-01-01

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

  15. Plaque autofluorescence as potential diagnostic targets for oral malodor

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  16. Endovascular Treatment of Ruptured Pericallosal Artery Aneurysms

    PubMed Central

    Ko, Jun Kyeung; Kim, Hwan Soo; Choi, Hyuk Jin; Lee, Tae Hong; Yun, Eun Young

    2015-01-01

    Objective Aneurysms arising from the pericallosal artery (PA) are uncommon and challenging to treat. The aim of this study was to report our experiences of the endovascular treatment of ruptured PA aneurysms. Methods From September 2003 to December 2013, 30 ruptured PA aneurysms in 30 patients were treated at our institution via an endovascular approach. Procedural data, clinical and angiographic results were retrospectively reviewed. Results Regarding immediate angiographic control, complete occlusion was achieved in 21 (70.0%) patients and near-complete occlusion in 9 (30.0%). Eight procedure-related complications occurred, including intraprocedural rupture and early rebleeding in three each, and thromboembolic event in two. At last follow-up, 18 patients were independent with a modified Rankin Scale (mRS) score of 0-2, and the other 12 were either dependent or had expired (mRS score, 3-6). Adjacent hematoma was found to be associated with an increased risk of poor clinical outcome. Seventeen of 23 surviving patients underwent follow-up conventional angiography (mean, 16.5 months). Results showed stable occlusion in 14 (82.4%), minor recanalization in two (11.8%), and major recanalization, which required recoiling, in one (5.9%). Conclusion Our experiences demonstrate that endovascular treatment for a ruptured PA aneurysms is both feasible and effective. However, periprocedural rebleedings were found to occur far more often (20.0%) than is generally suspected and to be associated with preoperative contrast retention. Analysis showed existing adjacent hematoma is predictive of a poor clinical outcome. PMID:26539261

  17. Spontaneous rupture of the plantar fascia.

    PubMed

    Ahstrom, J P

    1988-01-01

    In this study, rupture of the plantar fascia was seen in five feet, of which four had had plantar fasciitis. At the time of the injury, which is an acceleration type of motion, there is severe pain in the heel followed by the development of ecchymosis in the sole and toward the heel of the foot. With conservative symptomatic care, the acute symptoms as well as the plantar fasciitis symptoms subside, generally allowing full activity in 3 to 4 weeks.

  18. [Intradural rupture of an intervertebral disk].

    PubMed

    Paini, G P; Baldi, P G; Barra, N; Pasetti, S

    1978-01-01

    Since the first description of ruptured lumbar disc, erosion of a fragment of disc through the dura mater has been mentioned only rarely. The authros report two cases occurred among 1,078 herniated discs surgically treated in their department over a period of 8 years, from January 1st., 1970 through March 31st., 1978. Various factors that might contribute to this relatively rare complication of disc disease are mentioned, and literature on the subject is summarized.

  19. Fan-structure waves in shear ruptures

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris

    2016-04-01

    This presentation introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new slabs), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the correspondingly low transient strength of the lithosphere, which favours generation of new earthquake faults in the intact rock mass adjoining pre-existing faults in preference to frictional stick-slip instability along these faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created, while further dynamic propagation of the new fault (earthquake) occurs at low field stresses even below the frictional strength.

  20. Ruptured aneurysms of sinuses of Valsalva

    PubMed Central

    Jugdutt, B. I.; Fraser, R. S.; Rossall, R. E.; Lee, S. J. K.

    1974-01-01

    At least one additional cardiac lesion was present in 18 consecutive patients with ruptured aneurysms of the sinuses of Valsalva who were investigated between 1956 and 1973 at the University of Alberta Hospital. Clinical diagnosis was made in 78% (14/18) of the patients. Confirmation at cardiac catheterization, operation or autopsy was obtained in all but one. The main sites of rupture were the right ventricle (seven cases), right atrium (five) and left ventricle (five). Fifty percent (9/18) are alive and well following prompt operative repair, an average of 8.2 years later (range, six months to 15 years). Replacement of the aortic valve was associated with a high mortality (50% early, 13% late, total 63%) which could be explained by the higher operative risk in this group of very ill patients. Eight patients (44.4%) had had bacterial endocarditis prior to presentation and this may have played a significant role in the rupture of the sinus of Valsalva aneurysm. ImagesFIG. 4FIG. 5 PMID:4278257

  1. [Splenic artery rupture in pancreatic pseudocyst].

    PubMed

    Ungania, S; Panocchia, N

    2000-01-01

    Hemorrhage is one of the most threatening complication of pancreatic pseudocyst. It results from erosion of adjacent vessels. Splenic, gastroduodenal, pancreaticoduodenal and middle colic vessels are predominantly involved. Hemorrhage may present different feature: intra and/or extraperitoneal collection, gastrointestinal bleeding. The authors report the rupture of splenic artery into pseudocyst, with the formation of pulsating pseudoaneurysm, increasing progressively until the final rupture. For the diagnosis the authors utilized: ultrasounds (US) which showed the cyst but not its nature and content; the CT scan which disclosed haematic contents; finally the US Color Doppler which proved the dynamic feature of hemorrhage. This technique allows to identify the arterious or venous source of bleeding and the possible presence of arteriovenous fistula. Arteriography was not performed due to circumstances, although it would permit bleeding vessel embolization and the control of hemorrhage. This procedure is not ever achievable, and doesn't exclude the possibility of rebleeding. On surgery, since the intraoperative rupture of the pseudoaneurysm occurred with severe hypovolemic shock, only a timely posterior mesogastric mobilization and the medially displacement of spleen-body-tail pancreatic complex, allowed to clamp the mass and the hemostasis. When such lesion are approached, it is mandatory to be prepared to carry on this maneuver: the severity of bleeding cannot allow intracystic ligature of bleeding vessel.

  2. [Premature rupture of fetal membranes and chorioamnionitis].

    PubMed

    Haram, K; Daugaard, H O

    1994-05-10

    The article presents a survey of preterm rupture of the amniotic membranes at term (more than 1 hour prior to uterine contractions) and preterm (< 37 weeks). The diagnosis of rupture can be suspected from the history alone in 90% of the cases, and confirmed by inspection. In doubtful cases the pH in fluid from the posterior fornix of the vagina is determined and microscopy is performed. Amniotic fluid is alkaline. Microscopy of a dried specimen shows "ferning" when amniotic fluid is present (crystallization test). Staining with Nil blue will reveal orange foetal cells in fresh specimens, usually only late in pregnancy (after the 38 week). The crystallization test is useful, however, in all three trimesters. The cause of membrane rupture and of chorioamnionitis may be infection. Chorioamnionitis is a serious clinical condition, but can be subclinical and may occur with intact membranes. It can lead to preterm delivery. It is important that chorioamnionitis be diagnosed (maternal fever, tachycardia, uterine contractions, abdominal pain, foul smelling vaginal discharge and elevated C-reactive protein). The condition is treated with antibiotics and labour must be induced.

  3. Rupture models with dynamically determined breakdown displacement

    USGS Publications Warehouse

    Andrews, D.J.

    2004-01-01

    The critical breakdown displacement, Dc, in which friction drops to its sliding value, can be made dependent on event size by specifying friction to be a function of variables other than slip. Two such friction laws are examined here. The first is designed to achieve accuracy and smoothness in discrete numerical calculations. Consistent resolution throughout an evolving rupture is achieved by specifying friction as a function of elapsed time after peak stress is reached. Such a time-weakening model produces Dc and fracture energy proportional to the square root of distance rupture has propagated in the case of uniform stress drop. The second friction law is more physically motivated. Energy loss in a damage zone outside the slip zone has the effect of increasing Dc and limiting peak slip velocity (Andrews, 1976). This article demonstrates a converse effect, that artificially limiting slip velocity on a fault in an elastic medium has a toughening effect, increasing fracture energy and Dc proportionally to rupture propagation distance in the case of uniform stress drop. Both the time-weakening and the velocity-toughening models can be used in calculations with heterogeneous stress drop.

  4. Liver Hydatid Cyst with Transdiaphragmatic Rupture and Lung Hydatid Cyst Ruptured into Bronchi and Pleural Space

    SciTech Connect

    Ar Latin-Small-Letter-Dotless-I bas, Bilgin Kadri Dingil, Guerbuez; Koeroglu, Mert; Uenguel, Uemit; Zaral Latin-Small-Letter-Dotless-I , Aliye Ceylan

    2011-02-15

    The aim of this case study is to present effectiveness of percutaneous drainage as a treatment option of ruptured lung and liver hydatid cysts. A 65-year-old male patient was admitted with complicated liver and lung hydatid cysts. A liver hydatid cyst had ruptured transdiaphragmatically, and a lung hydatid cyst had ruptured both into bronchi and pleural space. The patient could not undergo surgery because of decreased respiratory function. Both cysts were drained percutaneously using oral albendazole. Povidone-iodine was used to treat the liver cyst after closure of the diaphragmatic rupture. The drainage was considered successful, and the patient had no recurrence of signs and symptoms. Clinical, laboratory, and radiologic recovery was observed during 2.5 months of catheterization. The patient was asymptomatic after catheter drainage. No recurrence was detected during 86 months of follow-up. For inoperable patients with ruptured liver and lung hydatid cysts, percutaneous drainage with oral albendazole is an alternative treatment option to surgery. The percutaneous approach can be life-saving in such cases.

  5. Effects of Apparent Supersonic Ruptures for Strike-slip Rupture: Should We Consider it in the Seismic Hazard Analysis?

    NASA Astrophysics Data System (ADS)

    Barrows, M. B.; Shao, G.; Ji, C.

    2009-12-01

    Recent numerical studies indicated that the supersonic rupture could produce larger off-fault damage at distant sites than the sub-shear rupture, due to the famous "mach cone" effect (Dunham and Archuleta, 2005; Bhat et al, 2007). These results were obtained using the steady-state rupture simulations in a half-space earth. For more realistic layered or 3D earth models, we should also consider the effects of apparent supersonic rupture, i.e., the deep rupture is still in a speed slower than the local shear velocity, but faster than the near surface S or even the P wave velocity. The apparent super-shear rupture could excite the mach effect, but how large it is has not yet been quantitatively addressed. In this study, we explore this possibility by performing numerical simulations for pure strike-slip ruptures on a vertical fault inside various layered earth models.

  6. Behavior of spindles and spindle plaques in the cell cycle and conjugation of Saccharomyces cerevisiae.

    PubMed Central

    Byers, B; Goetsch, L

    1975-01-01

    The interdependence of spindle plaque with other aspects of cell division and conjugation in Saccharomyces cerevisiae has been investigated. Three forms of the spindle plaque appear sequentially before the formation of the complete, intranuclear spindle. The single plaque is present initially in the mitotic cycle; it becomes transformed into a satellite-bearing single plaque during the latter part of G1. Subsequently, plaque duplication yields the double plaque characteristic of the early phase of budding, which coincides with the period of chromosome replication (S). The eventual separation of these plaques to form a complete spindle, with a single plaque at each pole, is nearly coincident with the completion of S. The form of the plaque differs in two independent cases of G1 arrest: the single plaque is found in a cell in stationary arrest of growth, whereas a cell arrested by mating factors in preparation for conjugation contains a satellite-bearing single plaque. The latter form is retained during zygote formation, where it serves as the initial site of fusion of each prezygotic nuceus with the other. This fusion results in the formation of a single zygotic nucleus with a satellite-bearing single plaque, which is subsequently transformed into a double plaque as the zygote buds. The double plaque is situated adjacent to the site of bud emergence in both vegetative cells and zygotes. Images PMID:1100612

  7. Low footwall accelerations and variable surface rupture behavior on the Fort Sage Mountains fault, northeast California

    USGS Publications Warehouse

    Briggs, Richard W.; Wesnousky, Steven G.; Brune, James N.; Purvance, Matthew D.; Mahan, Shannon

    2013-01-01

    The Fort Sage Mountains fault zone is a normal fault in the Walker Lane of the western Basin and Range that produced a small surface rupture (L 5.6 earthquake in 1950. We investigate the paleoseismic history of the Fort Sage fault and find evidence for two paleoearthquakes with surface displacements much larger than those observed in 1950. Rupture of the Fort Sage fault ∼5.6  ka resulted in surface displacements of at least 0.8–1.5 m, implying earthquake moment magnitudes (Mw) of 6.7–7.1. An older rupture at ∼20.5  ka displaced the ground at least 1.5 m, implying an earthquake of Mw 6.8–7.1. A field of precariously balanced rocks (PBRs) is located less than 1 km from the surface‐rupture trace of this Holocene‐active normal fault. Ground‐motion prediction equations (GMPEs) predict peak ground accelerations (PGAs) of 0.2–0.3g for the 1950 rupture and 0.3–0.5g for the ∼5.6  ka paleoearthquake one kilometer from the fault‐surface trace, yet field tests indicate that the Fort Sage PBRs will be toppled by PGAs between 0.1–0.3g. We discuss the paleoseismic history of the Fort Sage fault in the context of the nearby PBRs, GMPEs, and probabilistic seismic hazard maps for extensional regimes. If the Fort Sage PBRs are older than the mid‐Holocene rupture on the Fort Sage fault zone, this implies that current GMPEs may overestimate near‐fault footwall ground motions at this site.

  8. Rupture Velocities of Intermediate- and Deep-Focus Earthquakes

    NASA Astrophysics Data System (ADS)

    Warren, L. M.

    2014-12-01

    The rupture velocities of intermediate- and deep-focus earthquakes --- how they vary between subduction zones, how they vary with depth, and what their maximum values are --- may help constrain the mechanism(s) of the earthquakes. As part of a global study of intermediate- and deep-focus earthquakes, I have used rupture directivity to estimate the rupture vector (speed and orientation) for 422 earthquakes >70 km depth with MW ≥5.7 since 1990. I estimate the rupture velocity relative to the local P-wave velocity (vr/α). Since the same method is used for all earthquakes, the results can be readily compared across study areas. The study areas --- Middle America, South America, Tonga-Kermadec, Izu-Bonin-Marianas, and Japan-Kurils-Kamchatka --- include some of the warmest and coldest subduction zones: subducting plate ages range from 9-150 Myr and descent rates range from 1-13 cm/yr. Across all subduction zones and depth ranges, for the 193 earthquakes with observable directivity and well-constrained rupture vectors, most earthquakes rupture on the more horizontal of the two possible nodal planes. However, the rupture vectors appear to be randomly-oriented relative to the slip vector, so the earthquakes span the continuum from Mode II (i.e., parallel slip and rupture vectors) to Mode III rupture (i.e., perpendicular slip and rupture vectors). For this earthquake population, the mean rupture velocity is 0.43 vr/α ± 0.14 vr/α. The mean earthquake rupture velocities are similar between all subduction zones. Since the local seismic wavespeed is faster in colder subduction zones, absolute rupture velocities are faster in colder subduction zones. Overall, the fastest rupture velocities exceed the local S-wave speed. The supershear ruptures are associated with earthquakes closer to Mode II than Mode III faulting. This is consistent with theoretical calculations, which limit the rupture velocity to the S-wave speed for Mode III rupture but the P-wave speed for Mode II

  9. Coupling geodynamic earthquake cycles and dynamic ruptures

    NASA Astrophysics Data System (ADS)

    van Zelst, Iris; van Dinther, Ylona; Gabriel, Alice-Agnes; Heuret, Arnauld

    2016-04-01

    Studying the seismicity in a subduction zone and its effects on tsunamis requires diverse modelling methods that span spatial and temporal scales. Hundreds of years are necessary to build the stresses and strengths on a fault, while consequent earthquake rupture propagation is determined by both these initial fault conditions and the feedback of seismic waves over periods of seconds up to minutes. This dynamic rupture displaces the sea floor, thereby causing tsunamis. The aim of the ASCETE (Advanced Simulations of Coupled Earthquake and Tsunami Events) project is to study all these aspects and their interactions. Here, we present preliminary results of the first aspects in this modelling chain: the coupling of a seismo-thermo-mechanical (STM) code to the dynamic rupture model SeisSol. STM models of earthquake cycles have the advantage of solving multiple earthquake events in a self-consistent manner concerning stress, strength and geometry. However, the drawback of these models is that they often lack in spatial or temporal resolution and do not include wave propagation. In contrast, dynamic rupture models solve for frictional failure coupled to seismic wave propagation. We use the software package SeisSol (www.seissol.org) based on an ADER-DG discretization allowing high-order accuracy in space and time as well as flexible tetrahedral meshing. However, such simulations require assumptions on the initial fault stresses and strengths and its geometry, which are hard to constrain due to the lack of near-field observations and the complexity of coseismic conditions. By adapting the geometry as well as the stress and strength properties of the self-consistently developing non-finite fault zones from the geodynamic models as initial conditions for the dynamic rupture models, the advantages of both methods are exploited and modelling results may be compared. Our results show that a dynamic rupture can be triggered spontaneously and that the propagating rupture is

  10. The Therapeutic Effects of Intracavernosal Plaque Excision in Peyronie’s Disease: A None Grafting or Tunical Excising Procedure

    PubMed Central

    Ahmadnia, Hassan; Kamalati, Ali; Younesi Rostami, Mehdi; Imani, Mohammad Mehdi; Asadpour, Amir Abbas; Hariri, Mohammad Kazem

    2016-01-01

    BACKGROUND Current surgical treatments in Peyronie’s disease are accompanied by complications such as penile shortening, loss of sensation, erectile dysfunction and recurrence of disease. The aim of this study was the evaluation of clinical results of intracavernosal plaque excision in Peyronie’s disease. METHODS The operation was performed on 35 men. It was consisted of incising the tunica albuginea parallel to the plaque and through this incision, and the plaque was removed from the inside surface without excision or replacing the underlying tunica albuginea by grafts. All patients were evaluated before and periodically within 12 months after the surgery with measurement of penile length, curvature angle in the rigidity phase, and sexual satisfaction. RESULTS The mean age of patients was 51.4±5.3 years (range 42-59 years). The angle of penile curvature was 25-45° (mean=35°). Thirty patients (86%) obtained a nearly complete straightening of penis. All patients restored their previous penile length without any disorder of sensation within the glans penis and expressed improvement of sexual activity. CONCLUSION Intracavernosal plaque excision is a simple, easy and minimal invasive method that does not result in penile shortening, loss of sensation or erectile dysfunction. In properly selected patients, this technique can lead to acceptable elimination of penile curvature and sexual satisfaction. PMID:27308243

  11. Bifurcation analysis of a model for atherosclerotic plaque evolution

    NASA Astrophysics Data System (ADS)

    Bulelzai, M. A. K.; Dubbeldam, J. L. A.; Meijer, H. G. E.

    2014-06-01

    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 (σ). 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 dcrit and the conversion rate of the macrophages bcrit, 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.

  12. Effects of plaque lengths on stent surface roughness.

    PubMed

    Syaifudin, Achmad; Takeda, Ryo; Sasaki, Katsuhiko

    2015-01-01

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

  13. Dosimetric study of the 15 mm ROPES eye plaque

    SciTech Connect

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

    2004-12-01

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

  14. Parameter on plaque-induced gingivitis. American Academy of Periodontology.

    PubMed

    2000-05-01

    The American Academy of Periodontology has developed the following parameter on plaque-induced gingivitis in the absence of clinical attachment loss. Plaque-induced gingivitis is the most common form of the periodontal diseases, affecting a significant portion of the population in susceptible individuals. Patients should be informed of the disease process, therapeutic alternatives, potential complications, expected results, and their responsibility in treatment. Consequences of no treatment should be explained. No treatment may result in continuation of clinical signs of disease, with possible development of gingival defects and progression to periodontitis. Given this information, patients should then be able to make informed decisions regarding their periodontal therapy.

  15. Method of making a light weight battery plaque

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  16. Transcatheter Closure of Ruptured Sinus of Valsalva Aneurysm

    PubMed Central

    Al-Senaidi, Khalfan S.; Al-Farqani, Abdullah; Maddali, Madan; Al-Maskary, Salim

    2016-01-01

    A ruptured sinus of Valsalva aneurysm (RSVA) is a rare cardiac anomaly. Traditionally, RSVAs were repaired surgically; however, percutaneous transcatheter closure is the current treatment of choice. We report two cases of RSVA which were closed using this approach. The first case was a 45-year-old female who presented to the Royal Hospital, Muscat, Oman, in 2014 with a RSVA in the right ventricle. The second case was a 39-year-old male who was admitted to the Sultan Qaboos University Hospital, Muscat, in 2015 with a large multifenestrated RSVA extending into the right ventricle outflow tract. Each patient underwent transcutaneous cardiac catheterisation using three-dimensional echocardiography. Both interventions were technically successful; however, the second patient required a subsequent surgery due to the continuing presence of a significant shunt. Transcatheter closure of RSVAs is an effective alternative to surgical repair, although large multifenestrated RSVAs should be repaired surgically to ensure complete closure. PMID:28003903

  17. Splenic rupture following colonoscopy: Case report and literature review

    PubMed Central

    Zappa, Marco Antonio; Aiolfi, Alberto; Antonini, Ilaria; Musolino, Cinzia Domenica; Porta, Andrea

    2016-01-01

    Introduction Colonoscopy is a safe and routinely performed diagnostic and therapeutic procedure for colorectal diseases. Although bleeding and perforation are most common complications, extra colonic or visceral injuries have been described. Splenic rupture is rare with few cases reported in current literature. Presentation of case We report the case of a 73-year old man who presented to surgical consultation 50 h after colonoscopy. Clinical, laboratory and imaging findings were suggestive for haemoperitoneum. At surgery an almost complete splenic disruption was evident and urgent splenectomy was performed. Discussion Splenic injury following colonoscopy is exceptional, probably related to instrumental looping with excessive traction on the splenocolic ligament. In patients with an early presentation a sudden onset of symptoms is the rule. By contrast a delayed presentation (>48 h) is nonspecific and subtle with arduous diagnosis. Conclusion Awareness of this potential complication, high level of suspicion and prompt treatment are at the basis of better outcomes in such patients. PMID:26971282

  18. Environmental Durability and Stress Rupture of EBC/CMCs

    NASA Technical Reports Server (NTRS)

    Appleby, Matthew; Morscher, Gregory N.; Zhu, Dongming

    2012-01-01

    This research focuses on the strength and creep performance of SiC fiber-reinforced SiC ceramic matrix composite (CMC) environmental barrier coating (EBC) systems under complex simulated engine environments. Tensile-strength and stress-rupture testing was conducted to illustrate the material properties under isothermal and thermal gradient conditions. To determine material durability, further testing was conducted under exposure to thermal cycling, thermal gradients and simulated combustion environments. Emphasis is placed on experimental techniques as well as implementation of non-destructive evaluation, including modal acoustic emission and electrical resistivity monitoring, to characterize strength degradation and damage mechanisms. Currently, little is known about the behavior of EBC-CMCs under these conditions; consequently, this work will prove invaluable in the development of structural components for use in high temperature applications.

  19. The Energy Budget of Earthquake Rupture: a View From Spontaneous Rupture Modeling and Finite-Source Models

    NASA Astrophysics Data System (ADS)

    Mai, P.; Guatteri, M.

    2003-12-01

    It is a common and frustrating experience of many dynamic modelers to initiate spontaneous rupture calculations that subsequently abort before rupturing to the desired earthquake size [Nielsen and Olsen, 2000; Oglesby and Day, 2002]. Source parameters in such dynamic source models are strongly correlated, but stress drop is the main factor affecting the distribution of the other dynamic rupture parameters. Additionally, the position of the hypocenter exerts a strong influence on the dynamic properties of the earthquake, and certain hypocenter positions are not plausible as those would not lead to spontaneous rupture propagation. To further investigate this last statement, we analyze the energy budget during earthquake rupture using spontaneous dynamic rupture calculations and finite-source rupture models. In describing the energy budget during earthquake rupture, we follow Favreau and Archuleta [2003]. Each point on the fault contributes to the radiated seismic energy Ers = Eel - Efr - Erx, where Eel denotes the elasto-static energy and Efr the fracture energy. In this study we neglect for simplicity the relaxation work Erx spent during the stopping of the earthquake. A rupture can be characterized by locally negative seismic energy density values, but its integral over the fault plane must be positive. The fundamental condition for rupture growth is therefore that the integral of Ers on the rupture area remains always positive during rupture propagation. Based on a simple energy budget calculation, we focus on identifying those target slip/stress distribution in dynamic rupture modeling that for a given hypocenter location fail to rupture spontaneously. Additionally, we study the energy budget of finite-source rupture models by analyzing the integrated seismic energy for the inferred slip maps using also hypocenter positions other than the network location. These results indicate how rupture was promoted for the true hypocenter while randomized hypocenters may not

  20. [The role of blood-brain barrier in the pathogenesis of Alzheimer dementia--implications for immunological therapies for plaque dissolution].

    PubMed

    Pahnke, J; Krohn, M; Scheffler, K

    2009-08-01

    Alzheimer's disease (AD) is a devastating neurodegenerative disorder affecting more than 27 million people worldwide and leading to severe social-economic problems. One characteristic hallmark of AD--the amyloid plaques--are still being discussed to be one important triggering factor. However, current animal and autopsy studies refer to soluble and highly toxic A block oligomers as the deadly agent for the neurons. Current therapies mainly rely on the abatement of symptoms without antagonizing the etiology of the disease. Potential new approaches address reduced production, increased degradation and/or evacuation of toxic A block peptides from the brain. Among others one important group of target-proteins are the ABC transporters of the blood-brain barrier which contribute importantly to the detoxification of the brain. Changes of specific transport functions evoke important alterations for the known pathogenesis and future therapies of AD, especially approaches that target plaque dissolution and plaque reduction.

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

    SciTech Connect

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

    2015-06-15

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

  2. Measuring thermal rupture force distributions from an ensemble of trajectories.

    PubMed

    Swan, J W; Shindel, M M; Furst, E M

    2012-11-09

    Rupture, bond breaking, or extraction from a deep and narrow potential well requires considerable force while producing minimal displacement. In thermally fluctuating systems, there is not a single force required to achieve rupture, but a spectrum, as thermal forces can both augment and inhibit the bond breaking. We demonstrate measurement and interpretation of the distribution of rupture forces between pairs of colloidal particles bonded via the van der Waals attraction. The otherwise irreversible bond is broken by pulling the particles apart with optical tweezers. We show that an ensemble of the particle trajectories before, during and after the rupture event may be used to produce a high fidelity description of the distribution of rupture forces. This analysis is equally suitable for describing rupture forces in molecular and biomolecular contexts with a number of measurement techniques.

  3. Dynamic stress changes during earthquake rupture

    USGS Publications Warehouse

    Day, S.M.; Yu, G.; Wald, D.J.

    1998-01-01

    We assess two competing dynamic interpretations that have been proposed for the short slip durations characteristic of kinematic earthquake models derived by inversion of earthquake waveform and geodetic data. The first interpretation would require a fault constitutive relationship in which rapid dynamic restrengthening of the fault surface occurs after passage of the rupture front, a hypothesized mechanical behavior that has been referred to as "self-healing." The second interpretation would require sufficient spatial heterogeneity of stress drop to permit rapid equilibration of elastic stresses with the residual dynamic friction level, a condition we refer to as "geometrical constraint." These interpretations imply contrasting predictions for the time dependence of the fault-plane shear stresses. We compare these predictions with dynamic shear stress changes for the 1992 Landers (M 7.3), 1994 Northridge (M 6.7), and 1995 Kobe (M 6.9) earthquakes. Stress changes are computed from kinematic slip models of these earthquakes, using a finite-difference method. For each event, static stress drop is highly variable spatially, with high stress-drop patches embedded in a background of low, and largely negative, stress drop. The time histories of stress change show predominantly monotonic stress change after passage of the rupture front, settling to a residual level, without significant evidence for dynamic restrengthening. The stress change at the rupture front is usually gradual rather than abrupt, probably reflecting the limited resolution inherent in the underlying kinematic inversions. On the basis of this analysis, as well as recent similar results obtained independently for the Kobe and Morgan Hill earthquakes, we conclude that, at the present time, the self-healing hypothesis is unnecessary to explain earthquake kinematics.

  4. Treatment of Ruptured Vertebral Artery Dissecting Aneurysms

    PubMed Central

    Hamasaki, Osamu; Ikawa, Fusao; Hidaka, Toshikazu; Kurokawa, Yasuharu; Yonezawa, Ushio

    2014-01-01

    Summary We evaluated the outcomes of endovascular or surgical treatment of ruptured vertebral artery dissecting aneurysms (VADAs), and investigated the relations between treatment complications and the development and location of the posterior inferior cerebellar artery (PICA). We treated 14 patients (12 men, two women; mean age, 56.2 years) with ruptured VADAs between March 1999 and June 2012 at our hospital. Six and eight patients had Hunt and Hess grades 1-3 and 4-5, respectively. Twelve patients underwent internal endovascular trapping, one underwent proximal endovascular occlusion alone, and one underwent proximal endovascular occlusion in the acute stage and occipital artery (OA)-PICA anastomosis and surgical trapping in the chronic stage. The types of VADA based on their location relative to the ipsilateral PICA were distal, PICA-involved, and non-PICA in nine, two, and three patients, respectively. The types of PICA based on their development and location were bilateral anterior inferior cerebellar artery (AICA)-PICA, ipsilateral AICA-PICA, extradural, and intradural type in one, two, two, and nine patients, respectively. Two patients with high anatomical risk developed medullary infarction, but their midterm outcomes were better than in previous reports. The modified Rankin scale indicated grades 0-2, 3-5, and 6 in eight, three, and three patients, respectively. A good outcome is often obtained in the treatment of ruptured VADA using internal endovascular trapping, except in the PICA-involved type, even with high-grade subarachnoid hemorrhage. Treatment of the PICA-involved type is controversial. The anatomical location and development of PICA may be predicted by complications with postoperative medullary infarction. PMID:24976093

  5. Surgical repair of a rupture of the pectoralis major muscle

    PubMed Central

    Pochini, Alberto De Castro; Andreoli, Carlos Vicente; Ejnisman, Benno; Maffulli, Nicola

    2015-01-01

    Muscle rupture is rarely treated surgically. Few reports of good outcomes after muscular suture have been published. Usually, muscular lesions or partial ruptures heal with few side effects or result in total recovery. We report a case of an athlete who was treated surgically to repair a total muscular rupture in the pectoralis major muscle. After 6 months, the athlete returned to competitive practice. After a 2-year follow-up, the athlete still competes in skateboard championships. PMID:25716033

  6. Source Rupture Process of the 2005 Tarapaca Intermediate Depth Earthquake

    NASA Astrophysics Data System (ADS)

    Peyrat, S.; Favreau, P.; de Chabalier, J.; Bouin, M.

    2007-12-01

    We investigate the details of the rupture process of the large (Mw 7.7) intermediate-depth earthquake that occurred on 13 June 2005 in the Tarapaca region of the Northern Chile seismic gap, using different data sets and different methods. The high quality and variety of seismic and geodetic data available for this event provided an unprecedented opportunity to study its source in detail. This earthquake is a slab-pull event with down dip extensional source mechanism. The aftershock distribution, determined from a post-seismic temporary array, indicates a sub-horizontal fault plane lying between the upper and lower planes of the double seismic zone. This earthquake was also recorded by a permanent digital strong-motion network operated by the University of Chile. These records have absolute time and high dynamic range so that they contain direct information about the rupture process. We used a systematic, fully nonlinear inversion method based on the neighbourhood algorithm to invert for the kinematic slip distribution using the accelerometric data set. This low frequency inversion provides a relatively smooth image of the rupture history. The kinematic inversion shows that the earthquake occurred by the rupture of two asperities. Based on the kinematic inversion result, we propose dynamic rupture models in order to quantify the dynamic rupture process. We simulate the dynamic rupture process and the strong ground motion using a 3D finite-difference method. In our simulation, dynamic rupture grows under the simultaneous control of initial stress and rupture resistance by friction. We constrain dynamic rupture parameters of the Tarapaca earthquake by simple trial and error. Large intraplate earthquakes in subduction zone are quite common although very few have been studied in detail. These earthquakes occurred at depth where the mechanism by which they are triggered remains poorly understood. Consequently, the determination of source rupture for intermediate

  7. Alliance ruptures, impasses, and enactments: a relational perspective.

    PubMed

    Safran, Jeremy D; Kraus, Jessica

    2014-09-01

    Alliance ruptures, impasses, and transference-countertransference enactments are inevitable in therapy. A growing body of evidence suggests that repairing ruptures in the alliance is related to positive outcome (Safran, Muran, & Eubanks-Carter, 2011). Our research program has led to the development of training methods to enhance therapists' abilities to detect and work constructively with alliance ruptures and negative therapeutic process (Safran et al., 2014). This article outlines relevant theoretical underpinnings, intervention principles, and empirical findings.

  8. Spontaneous rupture of the urinary bladder in the puerperium.

    PubMed

    Kekre, A N; Kekre, N; Nath, V; Seshadri, L

    1997-11-01

    Spontaneous rupture of the urinary bladder in the puerperium is extremely rare. The patient usually presents with acute abdominal pain. Awareness on the part of the treating surgeon that bladder rupture is a possibility will lead to an early diagnosis. Immediate exploration, removing urine from the peritoneal cavity or retropubic space, closing the rupture and securing good vesical drainage, results in resumption of vesical function, and thereby decreases the mortality and morbidity.

  9. Complex earthquake rupture and local tsunamis

    USGS Publications Warehouse

    Geist, E.L.

    2002-01-01

    In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this variability is greatest for the most frequently occuring tsunamigenic subduction zone earthquakes in the magnitude range of 7 < Mw < 8.5. Variability in local tsunami runup scaling can be ascribed to tsunami source parameters that are independent of seismic moment: variations in the water depth in the source region, the combination of higher slip and lower shear modulus at shallow depth, and rupture complexity in the form of heterogeneous slip distribution patterns. The focus of this study is on the effect that rupture complexity has on the local tsunami wave field. A wide range of slip distribution patterns are generated using a stochastic, self-affine source model that is consistent with the falloff of far-field seismic displacement spectra at high frequencies. The synthetic slip distributions generated by the stochastic source model are discretized and the vertical displacement fields from point source elastic dislocation expressions are superimposed to compute the coseismic vertical displacement field. For shallow subduction zone earthquakes it is demonstrated that self-affine irregularities of the slip distribution result in significant variations in local tsunami amplitude. The effects of rupture complexity are less pronounced for earthquakes at greater depth or along faults with steep dip angles. For a test region along the Pacific coast of central Mexico, peak nearshore tsunami amplitude is calculated for a large number (N = 100) of synthetic slip distribution patterns, all with identical seismic moment (Mw = 8.1). Analysis of the results indicates that for earthquakes of a fixed location, geometry, and seismic moment, peak nearshore tsunami amplitude can vary by a

  10. Seismic rupture propagation beneath potential landslide wedge

    NASA Astrophysics Data System (ADS)

    Sakaguchi, A.; Kawamura, K.

    2011-12-01

    During 2011 Tohoku earthquake (Mw 9.0), much larger slip and tsunami occurred than expectation at outer-wedge (toe of the trench landward slope) of Japan trench (eg. Ide et al., 2011). Similarly, outer-wedge deformation was pointed out in northern segment of 1986 Meiji-Sanriku earthquake (Ms 7.2), and it was discussed that earthquake-related landslide induced large tsunami (eg. Kanamori, 1972; Tanioka and Satake, 1996). Many landslides and normal faults, potential tsunami genesis, are developed at outer-wedge of Japan trench (Henry et al., 1989). Some steep normal-faults turn to horizon at deep portion, and land sliding may be prevented by basal friction. If seismic rupture propagates to basal fault of the outer-wedge, triggered gravity collapse will enlarge deformation of the outer-wedge to cause large tsunamis. It was considered that seismogenic fault locks at deep portion under inner-wedge of the plate subduction zone, and outer-wedge was classified into aseismic zone classically. Seismic rupture propagation to outer-wedge is still uncertain. Seismic slip at the outer-wedge was found from the drilled core during IODP Nankai trough seismogenic zone drilling project (NanTroSEIZE) in Nankai trough, southwest Japan. Samples were obtained from the frontal thrust (438 mbsf), which connects the deep plate boundary to the seafloor at the toe of the accretionary wedge, and from a megasplay fault (271 mbsf) that branches from the plate boundary décollement. Higher vitrinite reflectance of 0.57 % and 0.37 % than the host rock of 0.24 % were found at splay and plate boundary faults zones respectively. These correspond with 300-400 °C and > 20°C of host rock. Local high temperature zone less than several cm thick may be caused by frictional shear heat at fault zone (Sakaguchi, et al., 2011). Shear velocity and durations can be estimated from thermal property of the sediment and distribution of the vitrinite anomaly (Hamada et al., 2011). This result shows that seismic

  11. MR microscopy of human amyloid-β deposits: characterization of parenchymal amyloid, diffuse plaques, and vascular amyloid.

    PubMed

    Nabuurs, Rob J A; Natté, Remco; de Ronde, Fenna M; Hegeman-Kleinn, Ingrid; Dijkstra, Jouke; van Duinen, Sjoerd G; Webb, Andrew G; Rozemuller, Annemieke J; van Buchem, Mark A; van der Weerd, Louise

    2013-01-01

    Cerebral deposits of amyloid-β peptides (Aβ) form the neuropathological hallmarks of Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). In the brain, Aβ can aggregate as insoluble fibrils present in amyloid plaques and vascular amyloid, or as diffuse plaques consisting of mainly non-fibrillar Aβ. Previously, magnetic resonance imaging (MRI) has been shown to be capable of detecting individual amyloid plaques, not only via the associated iron, but also Aβ itself has been suggested to be responsible for a decrease in the image intensity. In this current study we aim to investigate the MRI properties of the different cerebral Aβ deposits including diffuse plaques and vascular amyloid. Postmortem 60-μm-thick brain sections of AD, CAA, and Down's syndrome patients, known to contain Aβ, were studied. High resolution T2*- and T2-weighted MRI scans and quantitative relaxation maps were acquired using a microcoil on a Bruker 9.4T MRI system. Specific MRI characteristics of each type of Aβ deposit were examined by co-registration of the MRI with Congo Red and Aβ-immunostainings of the same sections. Our results show that only fibrillar Aβ, present in both vascular and parenchymal amyloid, induced a significant change in T2* and T2 values. However, signal changes were not as consistent for all of the vessels affected by CAA, irrespective of possible dyshoric changes. In contrast, the non-fibrillar diffuse plaques did not create any detectable MRI signal changes. These findings are relevant for the interpretation and further development of (quantitative) MRI methods for the detection and follow-up of AD and CAA.

  12. Fermentation of five sucrose isomers by human dental plaque bacteria.

    PubMed

    Matsuyama, J; Sato, T; Hoshino, E; Noda, T; Takahashi, N

    2003-01-01

    Sucrose has five structural isomers: palatinose, trehalulose, turanose, maltulose and leucrose. Although these isomers have been reported to be noncariogenic disaccharides, which cannot be utilized by mutans streptococci, there is no information about their fermentability by other bacteria in dental plaque. The purpose of the present study was to examine whether these isomers were fermented by predominant bacteria in human dental plaque. Clinical bacterial isolates obtained from dental plaque from 3 children aged 22 months to 50 months (146 strains) were inoculated into 3 ml of peptone-yeast extract (PY medium) containing glucose for 1 day, then an aliquot of 20 microl of culture medium was inoculated into 1 ml of PY medium containing 1% (w/v) of the respective test carbohydrates. After incubation for 1 day, the pH values and the optical density at 660 nm of the cultures were measured. Fermentation ability was measured by pH or=0.5. Of the clinical isolates, 33% fermented palatinose, and 69% of these were Actinomyces species. All of the palatinose-fermenting bacterial strains fermented trehalulose, 25% fermented turanose, 70% fermented maltulose and 23% fermented leucrose. We therefore conclude that, in human dental plaque, there are significant numbers of bacteria that are able to ferment sucrose isomers.

  13. 6. VIEW OF BRIDGE COMMEMORATIVE PLAQUE WHICH STATES '1908, J. ...

    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

  14. Congenital plaque-type glomuvenous malformation associated with chylous ascites.

    PubMed

    Tejedor, Maria; Martín-Santiago, Ana; Gómez, Cristina; Fiol, Miquel; Benítez-Segura, Ignacio

    2010-01-01

    Congenital plaque-type glomuvenous malformation (GVM) is caused by loss of function mutations in glomulin gene. We report a newborn with this rare vascular disorder associated with chylous ascites. The common mesenchymal origin of GVM and lymphatic vessels as well as the glomulin expression in vascular smooth muscle cells in utero could help explain this unusual prenatal complication of glomuvenous malformations.

  15. Aldehyde dehydrogenase 2 inhibits inflammatory response and regulates atherosclerotic plaque

    PubMed Central

    Wei, Shu-jian; Zhang, Ming-xiang; Wang, Xu-ping; Yuan, Qiu-huan; Xue, Li; Wang, Jia-li; Cui, Zhao-qiang; Zhang, Yun; Xu, Feng; Chen, Yu-guo

    2016-01-01

    Previous studies demonstrated that aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, which eliminates ALDH2 activity down to 1%-6%, is a susceptibility gene for coronary disease. Here we investigated the underlying mechanisms based on our prior clinical and experimental studies. Male apoE−/− mice were transfected with GFP, ALDH2-overexpression and ALDH2-RNAi lentivirus respectively (n=20 each) after constrictive collars were placed around the right common carotid arteries. Consequently, ALDH2 gene silencing led to an increased en face plaque area, more unstable plaque with heavier accumulation of lipids, more macrophages, less smooth muscle cells and collagen, which were associated with aggravated inflammation. However, ALDH2 overexpression displayed opposing effects. We also found that ALDH2 activity decreased in atherosclerotic plaques of human and aged apoE−/− mice. Moreover, in vitro experiments with human umbilical vein endothelial cells further illustrated that, inhibition of ALDH2 activity resulted in elevating inflammatory molecules, an increase of nuclear translocation of NF-κB, and enhanced phosphorylation of NF-κB p65, AP-1 c-Jun, Jun-N terminal kinase and p38 MAPK, while ALDH2 activation could trigger contrary effects. These findings suggested that ALDH2 can influence plaque development and vulnerability, and inflammation via MAPK, NF-κB and AP-1 signaling pathways. PMID:27191745

  16. Optical coherence tomography for imaging the vulnerable plaque

    NASA Astrophysics Data System (ADS)

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

    2006-03-01

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

  17. Development of Tc-99m Imaging Agents for Abeta Plaques

    SciTech Connect

    Zhi-Ping, Zhuang; Mei-Ping Kung; Catherihne Hou; Hank F. Kung

    2008-09-26

    Development of SPECT imaging agents based on Tc-99m targeting Aβ 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.

  18. APOLLO 16 TECHNICIAN ATTACHES PLAQUE TO LUNAR MODULE'S DESCENT STAGE

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Working inside the Apollo 16 Saturn V space vehicle at the launch pad, technician Ken Crow attaches a stainless steel plaque bearing the names of Apollo 16 astronauts John W. Young, Thomas K. Mattingly II and Charles M. Duke, Jr., to the Lunar Module's descent stage, which will remain on the Moon's surface.

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

    PubMed

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

    2016-02-01

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

  20. Ichthyosiform large plaque parapsoriasis: report of a rare entity.

    PubMed

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

    2013-09-01

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

  1. Reporting Casting Bronze Plaque Becomes Advisers Class Project

    ERIC Educational Resources Information Center

    Ross, Charlie

    1977-01-01

    Describes an advisers' class project (at the University of Oklahoma) which consisted of reporting on the casting of a bronze plaque bearing the names of the first school newspaper, "The Students Gazette," and its editor, Samuel M. Fox, for presentation in Philadelphia to commemorate scholastic journalism's Bicentennial. (MB)

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

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    2002-01-01

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

  3. 4. VISTA POINT AND INTERPRETIVE PLAQUE AT LEE VINING CANYON. ...

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

    4. VISTA POINT AND INTERPRETIVE PLAQUE AT LEE VINING CANYON. NOTE ROAD CUT ON CANYON WALL. LOOKING NNE. GIS: N-37 56 30.3 / 119 13 44.8 - Tioga Road, Between Crane Flat & Tioga Pass, Yosemite Village, Mariposa County, CA

  4. DETAIL VIEW OF GENERAL ELECTRIC PLAQUE INSIDE NORTHWEST CONTROL HOUSE ...

    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

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

    PubMed

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

    1980-06-01

    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.

  6. Effects of Along-strike Fault Heterogeneity on Rupture Propagation

    NASA Astrophysics Data System (ADS)

    Weng, H.; Yang, H.

    2015-12-01

    Fault zone materials have been suggested to be heterogeneous, such as along-strike variations of low velocity zone and stress conditions. How these fault heterogeneities affect earthquake rupture propagation is important to advance our understanding of earthquake physics, and yet remains poorly understood. Here we investigate the effects of along-strike fault heterogeneity on rupture propagation through numerical modeling on a strike-slip planar fault governed by a linear slip-weakening friction law. We first implement along-strike variations of fault zone materials based on field observations, which have shown the velocities of P and S waves of the low velocity zones can be reduced up to 50% compared to intact rocks. The rupture speed is decreased if the rupture propagates into materials with lower shear modulus and keeps at a stable speed quickly. In contrast, the rupture speed is increased if the rupture propagates into materials with higher shear modulus and accelerates into a steady speed more slowly. If this material boundary is very close to the nucleation zone, it may inhibit the nucleation process. In addition, there is always a perturbation on the rupture speed near the boundary due to the reflected energy. We then investigate the effects of a patch with elevated effective normal stress (barrier) on rupture propagation. Except for the distance d between the barrier and the nucleation zone, its width w, and the additional effective normal stress Δσn, all other parameters are kept constant for all the simulated models. Our results confirm that the barrier may slow down or stop coseismic ruptures, but may also induce supershear ruptures. Moreover, there is a sharp boundary between stopping the rupture and making very strong supershear ruptures. Furthermore, we demonstrate that the supershear rupture may emerge in a region that is delineated by two approximate linear boundaries for parameters d and w. The duration of supershear ruptures increases as the

  7. Numerical observer for atherosclerotic plaque classification in spectral computed tomography.

    PubMed

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

    2016-07-01

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

  8. TMI-2 lower head creep rupture analysis

    SciTech Connect

    Thinnes, G.L.

    1988-08-01

    The TMI-2 accident resulted in approximately 40% of the reactor's core melting and collecting on the lower head of the reactor pressure vessel. The severity of the accident has raised questions about the margin of safety against rupture of the lower head in this accident since all evidence seems to indicate no major breach of the vessel occurred. Scoping heat transfer analyses of the relocated core debris and lower head have been made based upon assumed core melting scenarios and core material debris formations while in contact with the lower head. This report describes the structural finite element creep rupture analysis of the lower head using a temperature transient judged most likely to challenge the structural capacity of the vessel. This evaluation of vessel response to this transient has provided insight into the creep mechanisms of the vessel wall, a realistic mode of failure, and a means by which margin to failure can be evaluated once examination provides estimated maximum wall temperatures. Suggestions for more extensive research in this area are also provided. 6 refs., 15 figs.

  9. Ruptures of the distal biceps tendon.

    PubMed

    Ward, James P; Shreve, Mark C; Youm, Thomas; Strauss, Eric J

    2014-01-01

    Distal biceps ruptures occur most commonly in middle-aged males and result from eccentric contraction of the biceps tendon. The injury typically presents with pain and a tearing sensation in the antecubital fossa with resultant weakness in flexion and supination strength. Physical exam maneuvers and diagnostic imaging aid in determining the diagnosis. Nonoperative management is reserved for elderly, low demand patients, while operative intervention is generally pursued for younger patients and can consist of nonanatomic repair to the brachialis or anatomic repair to the radial tuberosity. Anatomic repair through a one-incision or two-incision approach is commonplace, while the nonanatomic repairs are rarely performed. No clear advantage exists in operative management with a one-incision versus two-incision techniques. Chronic ruptures present a more difficult situation, and allograft augmentation is often necessary. Common complications after repair include transient nerve palsy, which often resolves, and heterotopic ossification. Despite these possible complications, most studies suggest that better patient outcomes are obtained with operative, anatomic reattachment of the distal biceps tendon.

  10. Plaque: What It Is and How to Get Rid of It

    MedlinePlus

    Rx for PLAQUE: Sound Teeth What it is and how to get rid of it People used to think that as you got older you naturally lost your teeth. ... your teeth for a lifetime! Plaque: What is it? Plaque is made up of invisible masses of ...

  11. 21 CFR 872.5580 - Oral rinse to reduce the adhesion of dental plaque.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... adhesion of dental plaque. (a) Identification. The device is assigned the generic name oral rinse to reduce... 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....

  12. Stable size distribution of amyloid plaques over the course of Alzheimer disease.

    PubMed

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

    2012-08-01

    Amyloid β plaques are a key pathologic feature of Alzheimer disease (AD), but whether plaque sizes increase or stabilize over the course of AD is unknown. We measured the size distribution of total immunoreactive (10D5-positive) and dense-core (Thioflavin S-positive) plaques in the temporal neocortex of a large group of subjects with AD and age-matched plaque-bearing subjects without dementia to test the hypothesis that amyloid plaques continue to grow along with the progression of the disease. The size of amyloid β (10D5)-positive plaques did not differ between groups, whereas dense-core plaques from the group with AD were slightly larger than those from the group without dementia (∼25%-30%, p = 0.01). Within the group with AD, dense-core plaque size did not independently correlate with duration of clinical disease (from 4 to 21 years, p = 0.68), whereas 10D5-positive plaque size correlated negatively with disease duration (p = 0.01). By contrast, an earlier age of symptom onset strongly predicted a larger postmortem plaque size; this effect was independent of disease duration and the presence of the APOE[Latin Small Letter Open E]4 allele (p = 0.0001). We conclude that plaques vary in size among patients, with larger size distributions correlating with an earlier age of onset, but plaques do not substantially increase in size over the clinical course of the disease.

  13. Rupture of Right Ventricular Free Wall Following Ventricular Septal Rupture in Takotsubo Cardiomyopathy with Right Ventricular Involvement

    PubMed Central

    Sung, June-Min; Chung, In-Hyun; Lee, Hye Young; Lee, Jae Hoon; Kim, Hyun-Jung; Byun, Young Sup; Kim, Byung Ok; Rhee, Kun Joo

    2017-01-01

    Most patients diagnosed with takotsubo cardiomyopathies are expected to almost completely recover, and their prognosis is excellent. However, complications can occur in the acute phase. We present a case of a woman with takotsubo cardiomyopathy with right ventricular involvement who developed a rupture of the right ventricular free wall following ventricular septal rupture, as a consequence of an acute increase in right ventricular afterload by left-to-right shunt. Our case report illustrates that takotsubo cardiomyopathy can be life threatening in the acute phase. Ventricular septal rupture in biventricular takotsubo cardiomyopathy may be a harbinger of cardiac tamponade by right ventricular rupture. PMID:27873520

  14. Rupture of Right Ventricular Free Wall Following Ventricular Septal Rupture in Takotsubo Cardiomyopathy with Right Ventricular Involvement.

    PubMed

    Sung, June Min; Hong, Sung Jin; Chung, In Hyun; Lee, Hye Young; Lee, Jae Hoon; Kim, Hyun Jung; Byun, Young Sup; Kim, Byung Ok; Rhee, Kun Joo

    2017-01-01

    Most patients diagnosed with takotsubo cardiomyopathies are expected to almost completely recover, and their prognosis is excellent. However, complications can occur in the acute phase. We present a case of a woman with takotsubo cardiomyopathy with right ventricular involvement who developed a rupture of the right ventricular free wall following ventricular septal rupture, as a consequence of an acute increase in right ventricular afterload by left-to-right shunt. Our case report illustrates that takotsubo cardiomyopathy can be life threatening in the acute phase. Ventricular septal rupture in biventricular takotsubo cardiomyopathy may be a harbinger of cardiac tamponade by right ventricular rupture.

  15. Creep-Rupture Behavior and Recrystallization in Cold-Bent Boiler Tubing for USC Applications

    SciTech Connect

    Shingledecker, John P

    2008-01-01

    Creep-rupture experiments were conducted on candidate Ultrasupercritical (USC) alloy tubes to evaluate the effects of cold-work and recrystallization during high-temperature service. These creep tests were performed by internally pressurizing cold-bent boiler tubes at 775 C for times up to 8000 hours. The bends were fabricated with cold-work levels beyond the current ASME Boiler and Pressure Vessel (ASME B&PV) Code Section I limits for austenitic stainless steels. Destructive metallographic evaluation of the crept tube bends was used to determine the effects of cold-work and the degree of recrystallization. The metallographic analysis combined with an evaluation of the creep and rupture data suggest that solid-solution strengthened nickel-based alloys can be fabricated for high-temperature service at USC conditions utilizing levels of cold-work higher than the current allowed levels for austenitic stainless steels.

  16. The "Ethics Rupture" Summit, Fredericton, New Brunswick, Canada, October 25-28, 2012.

    PubMed

    van den Hoonaard, Will C

    2013-02-01

    This report explains the background of the "Ethics Rupture" Summit held in New Brunswick, Canada, October 2012, focusing on the disconnect between research-ethics policies and the nature and purpose of social-science research-an unintended "rupture" in ethics governance. Ethics is about human relationships, and the governance of ethics must reflect that fact rather than function as a bureaucratic, self-legitimating system of control. The themes that emerged from the Summit point to: structural problems with the current system; an undermining of the original, historical mission of some social-science disciplines; a discomfort with new methodologies; ethics committees and the well-being and education of social-science students; the possibilities of reform and renewal; and the next steps. Finally, the report refers in broad outlines to a "New Brunswick Declaration," which is currently being considered by participants of the Summit.

  17. Coronary-Heart-Disease-Associated Genetic Variant at the COL4A1/COL4A2 Locus Affects COL4A1/COL4A2 Expression, Vascular Cell Survival, Atherosclerotic Plaque Stability and Risk of Myocardial Infarction

    PubMed Central

    Pu, Xiangyuan; Ren, Meixia; An, Weiwei; Zhang, Ruoxin; Yan, Shunying; Situ, Haiteng; He, Xinjie; Chen, Yequn; Tan, Xuerui; Xiao, Qingzhong; Tucker, Arthur T.; Caulfield, Mark J.; Ye, Shu

    2016-01-01

    Genome-wide association studies have revealed an association between coronary heart disease (CHD) and genetic variation on chromosome 13q34, with the lead single nucleotide polymorphism rs4773144 residing in the COL4A2 gene in this genomic region. We investigated the functional effects of this genetic variant. Analyses of primary cultures of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) from different individuals showed a difference between rs4773144 genotypes in COL4A2 and COL4A1 expression levels, being lowest in the G/G genotype, intermediate in A/G and highest in A/A. Chromatin immunoprecipitation followed by allelic imbalance assays of primary cultures of SMCs and ECs that were of the A/G genotype revealed that the G allele had lower transcriptional activity than the A allele. Electrophoretic mobility shift assays and luciferase reporter gene assays showed that a short DNA sequence encompassing the rs4773144 site interacted with a nuclear protein, with lower efficiency for the G allele, and that the G allele sequence had lower activity in driving reporter gene expression. Analyses of cultured SMCs from different individuals demonstrated that cells of the G/G genotype had higher apoptosis rates. Immunohistochemical and histological examinations of ex vivo atherosclerotic coronary arteries from different individuals disclosed that atherosclerotic plaques with the G/G genotype had lower collagen IV abundance and thinner fibrous cap, a hallmark of unstable, rupture-prone plaques. A study of a cohort of patients with angiographically documented coronary artery disease showed that patients of the G/G genotype had higher rates of myocardial infarction, a phenotype often caused by plaque rupture. These results indicate that the CHD-related genetic variant at the COL4A2 locus affects COL4A2/COL4A1 expression, SMC survival, and atherosclerotic plaque stability, providing a mechanistic explanation for the association between the genetic variant and CHD

  18. Lightweight porous plastic plaque. [nickel cadmium batteries

    NASA Technical Reports Server (NTRS)

    Reid, M.

    1978-01-01

    The porosity and platability of various materials were investigated to determine a suitable substrate for nickel-plated electrodes. Immersion, ultrasonics, and flow-through plating techniques were tried using nonproprietary formulations, and proprietary phosphide and boride baths. Modifications to the selected material include variations in formulation and treatment, carbon loading to increase conductivity, and the incorporation of a grid. Problems to be solved relate to determining conductivities and porosities as a function of amount of nickel plated on the plastics; loading; charge and discharge curves of electrodes at different current densities; cell performance; and long-term degradation of electrodes.

  19. Disruption of Amyloid Plaques Integrity Affects the Soluble Oligomers Content from Alzheimer Disease Brains

    PubMed Central

    Moyano, Javier; Sanchez-Mico, María; Torres, Manuel; Davila, Jose Carlos; Vizuete, Marisa; Gutierrez, Antonia; Vitorica, Javier

    2014-01-01

    The implication of soluble Abeta in the Alzheimer’s disease (AD) pathology is currently accepted. In fact, the content of soluble extracellular Abeta species, such as monomeric and/or oligomeric Abeta, seems to correlate with the clinico-pathological dysfunction observed in AD patients. However, the nature (monomeric, dimeric or other oligomers), the relative abundance, and the origin (extra-/intraneuronal or plaque-associated), of these soluble species are actually under debate. In this work we have characterized the soluble (defined as soluble in Tris-buffered saline after ultracentrifugation) Abeta, obtained from hippocampal samples of Braak II, Braak III–IV and Braak V–VI patients. Although the content of both Abeta40 and Abeta42 peptides displayed significant increase with pathology progression, our results demonstrated the presence of low, pg/µg protein, amount of both peptides. This low content could explain the absence (or below detection limits) of soluble Abeta peptides detected by western blots or by immunoprecipitation-western blot analysis. These data were in clear contrast to those published recently by different groups. Aiming to explain the reasons that determine these substantial differences, we also investigated whether the initial homogenization could mobilize Abeta from plaques, using 12-month-old PS1xAPP cortical samples. Our data demonstrated that manual homogenization (using Dounce) preserved the integrity of Abeta plaques whereas strong homogenization procedures (such as sonication) produced a vast redistribution of the Abeta species in all soluble and insoluble fractions. This artifact could explain the dissimilar and somehow controversial data between different groups analyzing human AD samples. PMID:25485545

  20. [Delayed iatrogenic tracheal post-intubation rupture. A short review of the aetiopathology and treatment].

    PubMed

    Pinegger, S; Gómez-Ríos, M A; Vizcaíno, L; Carillo, M

    2013-05-01

    Iatrogenic tracheal rupture is a rare complication with a high morbidity and mortality. Tracheal intubation is the main cause and its origin is multifactorial. The diagnosis is based on non-specific but highly suggestive signs and symptoms, such as subcutaneous emphysema, pneumothorax, respiratory distress, or haemoptysis. Confirmation of the diagnosis requires an examination by bronchoscopy. Surgical repair has traditionally been the treatment of choice although the current trend is conservative management.

  1. Some observations regarding the statistical determination of stress rupture regression lines

    NASA Technical Reports Server (NTRS)

    Pizzo, P. P.

    1979-01-01

    Observations concerning the statistical evaluation of creep data are presented. Methods currently employed in the determination of stress rupture regression lines can result in conflicting and necessarily invalid results. Anomalous behavior is principally associated with the selection of the dependent variable. However, it is the least squares method of curve fitting which introduces regression bias. Methods to improve the validity of least squares regressions are suggested.

  2. Quantification of arterial plaque and lumen density with MDCT

    SciTech Connect

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

    2010-08-15

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

  3. Adaptive, High-Order, and Scalable Software Elements for Dynamic Rupture Simulations in Complex Geometries

    NASA Astrophysics Data System (ADS)

    Kozdon, J. E.; Wilcox, L.; Aranda, A. R.

    2014-12-01

    The goal of this work is to develop a new set of simulation tools for earthquake rupture dynamics based on state-of-the-art high-order, adaptive numerical methods capable of handling complex geometries. High-order methods are ideal for earthquake rupture simulations as the problems are wave-dominated and the waves excited in simulations propagate over distance much larger than their fundamental wavelength. When high-order methods are used for such problems significantly fewer degrees of freedom are required as compared with low-order methods. The base numerical method in our new software elements is a discontinuous Galerkin method based on curved, Kronecker product hexahedral elements. We currently use MPI for off-node parallelism and are in the process of exploring strategies for on-node parallelism. Spatial mesh adaptivity is handled using the p4est library and temporal adaptivity is achieved through an Adams-Bashforth based local time stepping method; we are presently in the process of including dynamic spatial adaptivity which we believe will be valuable for capturing the small-scale features around the propagating rupture front. One of the key features of our software elements is that the method is provably stable, even after the inclusion of the nonlinear frictions laws which govern rupture dynamics. In this presentation we will both outline the structure of the software elements as well as validate the rupture dynamics with SCEC benchmark test problems. We are also presently developing several realistic simulation geometries which may also be reported on. Finally, the software elements that we have designed are fully public domain and have been designed with tightly coupled, wave dominated multiphysics applications in mind. This latter design decisions means the software elements are applicable to many other geophysical and non-geophysical applications.

  4. Near-Field Deformation Associated with the M6.0 South Napa Earthquake Surface Rupture

    NASA Astrophysics Data System (ADS)

    Brooks, B. A.; Hudnut, K. W.; Glennie, C. L.; Ericksen, T.

    2014-12-01

    We characterize near-field deformation associated with the surface rupture of the M6.0 South Napa earthquake from repeat mobile laser scanning (MLS) surveys. Starting the day after the main shock, we operated, sometime simultaneously, short (~75 m range) and medium (~400m range) range laser scanners on a truck or backpack. We scanned most of the length of the principal and secondary surface ruptures at speeds less than 10 km/hr. Scanning occurred primarily in either suburban subdivisions or cultivated vineyards of varying varietals with differing leaf patterns and stages of maturity. Spot-spacing is dense enough (100s of points/m^2) to permit creation of 10-25cm digital elevation models of much of the surface rupture. Scanned features of the right-lateral rupture include classic mole tracks through a variety of soil types, en echelon cracks, offset vine rows, and myriad types of pavement-related deformation. We estimate coseismic surface displacements ranging from 5 to 45 cm by examining offset cultural features and vine rows and by comparing the MLS data with preexisting airborne laser scans from 2003 using point-cloud and solid-modeling methodologies. Additionally, we conducted repeat MLS scans to measure the magnitude and spatial variation of fault afterslip, exceeding 20 cm in some places, particularly in the southern portion of the rupture zone. We anticipate these data sets, in conjunction with independently collected ground-based alinement arrays and space-based geodetic data will contribute significant insight into topics of current debate including assessing the most appropriate material models for shallow fault zones and how shallow and deeper fault slip relate to one another.

  5. Spontaneous gastroduodenal artery aneurysm rupture in acute surgery.

    PubMed

    Savage, Jessica; Hsee, Li

    2012-06-29

    Among the rarest of the visceral aneurysms, gastroduodenal artery (GDA) aneurysms often present with spontaneous rupture and are associated with a high mortality rate. Their aetiology is poorly understood. This report describes a case of haemorrhagic shock due to sudden GDA aneurysm rupture in a patient with a significant autoimmune history.

  6. Delayed rupture of renal artery after renal percutaneous transluminal angioplasty

    SciTech Connect

    Puijlaert, C.B.A.J.; Mali, W.P.; Rosenbusch, G.; van Straalen, A.M.; Klinge, J.; Feldberg, M.A.M.

    1986-06-01

    Two cases are reported in which rupture of the renal artery occurred many hours after renal percutaneous transluminal angioplasty. Delayed rupture can be recognized by the angiographic appearance and by the presence of persistent flank pain. The typical angiographic finding is a poorly defined zone of contrast medium at the site of perforation.

  7. The Resolution of Ruptures in the Therapeutic Alliance.

    ERIC Educational Resources Information Center

    Safran, Jeremy D.; Muran, J. Christopher

    1996-01-01

    A rupture in the therapeutic alliance is a deterioration in the quality of the relationship between patient and therapist; it is an interpersonal marker that indicates an opportunity for exploring and understanding the processes that maintain a maladaptive interpersonal schema. Outlines features of a research program on ruptures in the therapeutic…

  8. Comparing two methods of identifying alliance rupture events.

    PubMed

    Coutinho, Joana; Ribeiro, Eugénia; Sousa, Inês; Safran, Jeremy D

    2014-09-01

    This study compared two methods of detecting ruptures in therapy sessions, a procedure based on a self-report measure, the Working Alliance Inventory (WAI), and an observational Rupture Resolution Rating System (3RS). We anticipated that the 3RS would detect more ruptures than the WAI. We examined the longitudinal data of 38 patient-therapist dyads in a cognitive-behavioral therapy condition. The sample included cases that did not complete treatment (dropped cases) as well as good-outcome and poor-outcome cases. At the end of each session, patients completed the WAI self-report questionnaire. Six judges were trained to observe and detect the occurrence of ruptures, and then rated 201 videotaped sessions. Longitudinal statistical models were applied to the data retrieved from the WAI questionnaires completed by patients. We found discrepancies in the ability of the two methods to detect rupture events with the observational 3RS detecting more ruptures than the WAI. Thus, the use of observational systems for the detection of alliance ruptures is crucial for effectively assessing the quality of the therapeutic alliance over the course of treatment. Furthermore, observational systems proven to detect ruptures can be used to improve clinical practice and training of new clinicians.

  9. Spontaneous rupture of a liver hemangioma. A case report.

    PubMed

    Guillén-Paredes, María Pilar; Martínez Fernández, Josefa; Morales González, Álvaro; Pardo-García, José Luis

    2016-07-01

    Spontaneous rupture of a liver hemangioma is a very uncommon disease, but extremely seriousness because it is associated to a 75% of mortality caused by hipovolemic shock. A case of an spontaneous rupture of liver hemangioma, which was previously unknow, is presented.

  10. Diverse rupture processes in the 2015 Peru deep earthquake doublet

    PubMed Central

    Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

    2016-01-01

    Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes. PMID:27386585

  11. Diverse rupture processes in the 2015 Peru deep earthquake doublet.

    PubMed

    Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

    2016-06-01

    Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes.

  12. Tibialis posterior tendon rupture: a cause of rheumatoid flat foot.

    PubMed

    Downey, D J; Simkin, P A; Mack, L A; Richardson, M L; Kilcoyne, R F; Hansen, S T

    1988-03-01

    Flat foot, a major cause of foot pain and disability, may result from rupture of the tibialis posterior tendon. We describe 2 patients with rheumatoid arthritis who developed flat feet secondary to surgically confirmed tendon rupture, and we discuss the anatomy and diagnosis of this condition. In the second patient, we also present the results of tendon imaging with both magnetic resonance and ultrasound.

  13. Tracheal rupture in a cat: diagnosis by computed tomography.

    PubMed

    Bhandal, Jitender; Kuzma, Alan

    2008-06-01

    A cat was presented with a history of worsening generalized subcutaneous emphysema following dental prophylaxis. Tentative diagnosis of tracheal rupture was made. The location and extent of the tear was confirmed with the help of computed tomography. This is the 1st computed tomographic description of tracheal rupture in the veterinary literature.

  14. Antibody-labeled liposomes for CT imaging of atherosclerotic plaques: in vitro investigation of an anti-ICAM antibody-labeled liposome containing iohexol for molecular imaging of atherosclerotic plaques via computed tomography.

    PubMed

    Danila, Delia; Partha, Ranga; Elrod, Don B; Lackey, Melinda; Casscells, S Ward; Conyers, Jodie L

    2009-01-01

    We evaluated the specific binding of anti-intercellular adhesion molecule 1 (ICAM-1) conjugated liposomes (immunoliposomes, or ILs) to activated human coronary artery endothelial cells (HCAEC) with the purpose of designing a computed tomographic imaging agent for early detection of atherosclerotic plaques. Covalent attachment of anti-ICAM-1 monoclonal antibodies to pre-formed liposomes stabilized with polyethylene glycol yielded ILs, with a coupling efficiency of the ICAM-1 to the liposomes of 10% to 24%. The anti-ICAM-1-labeled ILs had an average diameter of 136 nm as determined by dynamic light-scattering and cryogenic electron microscopy. The ILs' encapsulation of 5-[N-acetyl-(2,3-dihydroxypropyl)-amino)-N, N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-benzene-1,3-dicarboxamide (iohexol) was determined to be 18% to 19% by a dialysis technique coupled with ultraviolet detection of free iohexol. This encapsulation corresponded to 30 to 38 mg iodine per mL IL solution, and the ILs exhibited 91% to 98.5% iohexol retention at room temperature and under physiologic conditions. The specific binding of the ILs to cultured, activated HCAEC was measured using flow cytometry, enzyme-linked immunosorbent assays, and fluorescence microscopy. The immunosorbent assays demonstrated the specificity of binding of anti-ICAM-1 to ICAM-1 compared with control studies using nonspecific immunoglobulin G-labeled ILs. Flow cytometry and fluorescence microscopy experiments demonstrated the expression of ICAM-1 on the surface of activated HCAEC. Therefore, our iohexol-filled ILs demonstrated potential for implementation in computed tomographic angiography to noninvasively detect atherosclerotic plaques that are prone to rupture.

  15. Relaxing Segmentation: Does It Improve Characterization of Fault Rupture Behavior?

    NASA Astrophysics Data System (ADS)

    Schwartz, D. P.

    2014-12-01

    Most faults have not ruptured once historically, let alone repeatedly. Estimating future rupture length of an earthquake source has been a challenge since the 1970s when concepts of full and half fault lengths were employed. In the 1980s paleoseismic event timing and observations of slip, coupled with geometric and other physical fault changes, led to concepts of fault segmentation and it's modeling for hazard. The Uniform California Earthquake Rupture Forecast 3 (UCERF 3, Field et al., 2014) relaxed segmentation, guided by rules in which a separation distance of ≤5km and orientation to Coulomb stress changes at fault junctions are prime factors for allowing fault-to-fault jumps. A set of ~350 fault sections produced ~250K ruptures ranging in length from 15 km-1200 km. An inversion provided the rates of these, which range from 102-108 years. Many of the long ruptures have exceedingly low individual rates within the UCERF 3 geologic model but are sufficient in number to release cumulative moment that brings the long-term (Myr) and historical (since 1850) MFDs for the California region into close agreement. Does UCERF 3 have too many multi-fault ruptures? Since 1850 there have been ~260 surface ruptures worldwide in shallow continental crust. 77% are 0-49km; 6% exceed 150km, and the longest is 1906 San Francisco (435-470 km). In California since 1857 there have been 31 surface ruptures. 77% are shorter than 49 km. The longest are 1906, 1857 Fort Tejon (297km), and 1872 Owens Valley (108 km). Most long historical strike-slip ruptures are continuous and geomorphically well-defined traces with limited geometric changes. In contrast, UCERF3 modeling of the south Hayward, as an example, allows it to participate in ruptures that extend to the south ends of the San Andreas or San Jacinto faults (900 km). These include branching (Hayward-Calaveras, San Andreas-San Jacinto) and jumps (Calaveras-San Andreas) on creeping sections of these faults. 5km is the connectivity

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

    NASA Astrophysics Data System (ADS)

    Friedman, Avner; Hao, Wenrui; Hu, Bei

    2015-08-01

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

  17. Control of seafloor roughness on earthquake rupture behavior

    NASA Astrophysics Data System (ADS)

    Bilek, Susan L.; Schwartz, Susan Y.; Deshon, Heather R.

    2003-05-01

    Earthquake rupture complexity is described for three recent large underthrusting earthquakes along the Costa Rican subduction zone, the 1983 Osa, 1990 Nicoya Gulf, and 1999 Quepos events. These earthquakes occurred in regions characterized by distinctly different morphologic features on the subducting plate. The 1990 and 1999 events occurred along linear projections of subducting seamount chains and had fairly simple earthquake rupture histories. Both events are interpreted as failure of the basal contact of closely spaced isolated seamounts acting as asperities. In contrast, the 1983 event occurred along the subducting Cocos Ridge and had a complex rupture history. Comparison of rupture characteristics of these large underthrusting earthquakes with size and location of subducting features provides evidence that seamounts can be subducted to seismogenic depths and that variations in seafloor bathymetry of the subducting plate strongly influence the earthquake rupture process.

  18. Material contrast does not predict earthquake rupture propagation direction

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    2005-01-01

    Earthquakes often occur on faults that juxtapose different rocks. The result is rupture behavior that differs from that of an earthquake occurring on a fault in a homogeneous material. Previous 2D numerical simulations have studied simple cases of earthquake rupture propagation where there is a material contrast across a fault and have come to two different conclusions: 1) earthquake rupture propagation direction can be predicted from the material contrast, and 2) earthquake rupture propagation direction cannot be predicted from the material contrast. In this paper we provide observational evidence from 70 years of earthquakes at Parkfield, CA, and new 3D numerical simulations. Both the observations and the numerical simulations demonstrate that earthquake rupture propagation direction is unlikely to be predictable on the basis of a material contrast. Copyright 2005 by the American Geophysical Union.

  19. Incidence of plantar fascia ruptures following corticosteroid injection.

    PubMed

    Kim, Chul; Cashdollar, Michael R; Mendicino, Robert W; Catanzariti, Alan R; Fuge, LaDonna

    2010-12-01

    Plantar fasciitis is commonly treated with corticosteroid injections to decrease pain and inflammation. Therapeutic benefits often vary in terms of efficacy and duration. Rupture of the plantar fascia has been reported as a possible complication following corticosteroid injection. A retrospective chart review of 120 patients who received corticosteroid injection for plantar fasciitis was performed at the authors' institution to determine the incidence of plantar fascia rupture. The plantar fascia rupture was diagnosed clinically and confirmed with magnetic resonance imaging. Various factors were analyzed, including the number of injections, interval between injections, body mass index (BMI), and activity level. Four patients (2.4%) consequently experienced plantar fascia rupture following an average of 2.67 injections. The average BMI of these patients was 38.6 kg/m². The authors conclude that corticosteroid injection therapy appears to be a safe and effective form of nonoperative treatment with minimal complications and a relatively low incident of plantar fascia rupture.

  20. Pneumatic Rupture of Rectosigmoid; a Case Report.

    PubMed

    Montazeri, Mohammad; Farhangi, Bahman; Montazeri, Mahmood

    2014-01-01

    Pneumatic rectosigmoid rapture is usually occurred following the inappropriate fun by direct entering a high volume of the air through the pneumatic device to the anus. Such an event was reported for the first time in 1904 by Stone. Diagnosis and treatment of such injuries are often delayed because of some social limitations and preventing the patient form explaining the event. Colon sigmoid rupture and pneumoperitoneum is one of the most dangerous and life treating complications of entering a high volume of the air to the rectum in a short time. There are only a few reports regarding the similar cases. Here, a case of pneumatic rectosigmoid rapture was reported in a 53 year-old male following an inappropriate fun.

  1. Unresponsive primipara after rupture of membranes.

    PubMed

    Buechel, Johanna; Berset, Andreas; Lehmann, Michael A; Lapaire, Olav

    2015-04-16

    Amniotic fluid embolism, also called anaphylactoid syndrome of pregnancy, is a rare but severe problem in obstetrics. It occurs in 8/100,000 births and the maternal mortality is up to 90%. We report the case of a patient with amniotic fluid embolism who was transferred to our hospital. The initial presentation was an unresponsive patient after spontaneous rupture of the membranes. The massive hypotension and coagulopathy as well as fetal bradycardia of 60 bpm led, after stabilisation of the mother, to an emergency caesarean section. The neonate expired hours later, despite neonatological intensive care. During the operation, we had to deal with massive bleeding due to the coagulopathy. Through interdisciplinary teamwork including Bakri postpartum balloon insertion through the obstetrics team, uterine artery embolism by the interventional radiologists and transfusion of blood products, the maternal life was saved and the patient was discharged 9 days after admission.

  2. Apollo 11 Commander Armstrong Presents President With Commemorative Plaque

    NASA Technical Reports Server (NTRS)

    1974-01-01

    On June 4, 1974, 5 years after the successful Apollo 11 lunar landing mission, commander Neil Armstrong (right) presented a plaque to U.S. President Richard Milhous Nixon (left) on behalf of all people who had taken part in the space program. In making the presentation, Armstrong said 'Mr. President, you have proclaimed this week to be United States Space week in conjunction with the fifth anniversary of our first successful landing on the Moon. It is my privilege to represent my colleagues, the crewmen of projects Mercury, Gemini, Apollo, and Skylab, and the men and women of NASA, and the hundreds of thousands of Americans from across the land who contributed so mightily to the success of our efforts in space in presenting this plaque which bears the names of each individual who has had the privilege of representing this country' in a space flight. The presentation was made at the California white house in San Clemente.

  3. Multiple keratoacanthomas developing in healing plaques of Psoriasis

    PubMed Central

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

    2013-01-01

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

  4. Endovascular treatment of ruptured tiny (⩽3mm) intracranial aneurysms in the setting of subarachnoid hemorrhage: A case series of 20 patients and literature review.

    PubMed

    Anokwute, Miracle C; Braca, John A; Bohnstedt, Bradley; DeNardo, Andrew; Scott, John; Cohen-Gadol, Aaron; Sahlein, Daniel H

    2017-03-24

    Successful endovascular coiling of ruptured tiny saccular intracranial aneurysms (⩽3mm) is technically challenging and traditionally has been associated with technical failures, as well as morbidity related to thromboembolic events and high intraoperative rupture rates. This study analyzes the feasibility, technical efficacy, and clinical outcomes of coil embolization of ruptured tiny intracranial aneurysms using current coil and microcatheter technology and techniques. We performed a retrospective review of 20 patients with 20 ruptured tiny aneurysms treated with endovascular coil embolization from 2013 to 2016 at a single high-volume academic tertiary care practice. The mean aneurysm size was 2.4mm (median 2.5mm, 1-3). Complete occlusion was achieved in 12 of 20 patients (60%), the remaining 7 of 20 patients (35%) had a small neck remnant, and there was 1 failure (5%) converted to microsurgical clipping. Two patients had a failed attempted surgical clip reconstruction and were subsequently coiled. There was 1 intraprocedural rupture (5%) and 1 severe parent artery vasospasm (5%) during coiling. At discharge, 60% of patients were living independently. At follow-up three patients were deceased. Mean angiographic follow-up was 139days (SD 120). There were no aneurysm recurrences among occluded patients and there were no retreatments among those with neck remnants. Coiling of ruptured aneurysms ⩽3mm is feasible with high occlusion rates and low complication rates. The availability of softer coils with flexible detachment zones has led to safe and effective endovascular treatment of tiny ruptured aneurysms.

  5. Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation.

    PubMed

    Zimmermann, Leonard W; Amoush, Ahmad; Wilkinson, Douglas A

    2015-11-08

    This work is a comparative study of the dosimetry calculated by Plaque Simulator, a treatment planning system for eye plaque brachytherapy, to the dosimetry calculated using Monte Carlo simulation for an Eye Physics model EP917 eye plaque. Monte Carlo (MC) simulation using MCNPX 2.7 was used to calculate the central axis dose in water for an EP917 eye plaque fully loaded with 17 IsoAid Advantage (125)I seeds. In addition, the dosimetry parameters Λ, gL(r), and F(r,θ) were calculated for the IsoAid Advantage model IAI-125 (125)I seed and benchmarked against published data. Bebig Plaque Simulator (PS) v5.74 was used to calculate the central axis dose based on the AAPM Updated Task Group 43 (TG-43U1) dose formalism. The calculated central axis dose from MC and PS was then compared. When the MC dosimetry parameters for the IsoAid Advantage (125)I seed were compared with the consensus values, Λ agreed with the consensus value to within 2.3%. However, much larger differences were found between MC calculated gL(r) and F(r,θ) and the consensus values. The differences between MC-calculated dosimetry parameters are much smaller when compared with recently published data. The differences between the calculated central axis absolute dose from MC and PS ranged from 5% to 10% for distances between 1 and 12 mm from the outer scleral surface. When the dosimetry parameters for the (125)I seed from this study were used in PS, the calculated absolute central axis dose differences were reduced by 2.3% from depths of 4 to 12 mm from the outer scleral surface. We conclude that PS adequately models the central dose profile of this plaque using its defaults for the IsoAid model IAI-125 at distances of 1 to 7 mm from the outer scleral surface. However, improved dose accuracy can be obtained by using updated dosimetry parameters for the IsoAid model IAI-125 (125)I seed.

  6. Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation.

    PubMed

    Zimmermann, Leonard W; Amoush, Ahmad; Wilkinson, Douglas A

    2015-11-01

    This work is a comparative study of the dosimetry calculated by Plaque Simulator, a treatment planning system for eye plaque brachytherapy, to the dosimetry calculated using Monte Carlo simulation for an Eye Physics model EP917 eye plaque. Monte Carlo (MC) simulation using MCNPX 2.7 was used to calculate the central axis dose in water for an EP917 eye plaque fully loaded with 17 IsoAid Advantage  125I seeds. In addition, the dosimetry parameters Λ, gL(r), and F(r,θ) were calculated for the IsoAid Advantage model IAI-125  125I seed and benchmarked against published data. Bebig Plaque Simulator (PS) v5.74 was used to calculate the central axis dose based on the AAPM Updated Task Group 43 (TG-43U1) dose formalism. The calculated central axis dose from MC and PS was then compared. When the MC dosimetry parameters for the IsoAid Advantage  125I seed were compared with the consensus values, Λ agreed with the consensus value to within 2.3%. However, much larger differences were found between MC calculated gL(r) and F(r,θ) and the consensus values. The differences between MC-calculated dosimetry parameters are much smaller when compared with recently published data. The differences between the calculated central axis absolute dose from MC and PS ranged from 5% to 10% for distances between 1 and 12 mm from the outer scleral surface. When the dosimetry parameters for the  125I seed from this study were used in PS, the calculated absolute central axis dose differences were reduced by 2.3% from depths of 4 to 12 mm from the outer scleral surface. We conclude that PS adequately models the central dose profile of this plaque using its defaults for the IsoAid model IAI-125 at distances of 1 to 7 mm from the outer scleral surface. However, improved dose accuracy can be obtained by using updated dosimetry parameters for the IsoAid model IAI-125  125I seed. PACS number: 87.55.K.

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  9. Computerized flow and vessel wall analyses of coronary arteries for detection of non-calcified plaques in coronary CT angiography

    NASA Astrophysics Data System (ADS)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Hadjiiski, Lubomir; Kazerooni, Ella

    2016-03-01

    The buildup of non-calcified plaques (NCP) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. We are developing a computer-aided detection (CADe) system to assist radiologists in detecting NCPs in cCTA. A major challenge of NCP detection is the large number of false positives (FPs) caused by the small sized coronary arteries, image noise and artifacts. In this study, our purpose is to design new image features to reduce FPs. A data set of 98 cCTA scans was retrospectively collected from patient files. We first used vessel wall analysis, in which topological features were extracted from vessel wall and fused with a support-vector machine, to identify the NCP candidates from the segmented coronary tree. Computerized flow dynamic (CFD) features that characterize the change in blood flow due to the presence of plaques and a vascular cross-sectional (VCS) feature that quantifies the presence of low attenuation region at the vessel wall were designed for FP reduction. Using a leave-one-out resampling method, a support vector machine classifier was trained to merge the features into a NCP likelihood score using the vessel wall features alone or in combination with the new CDF and VCS features. The performance of the new features in classification of true NCPs and FPs was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC). Without the new CFD and VCS features, the test AUC was 0.84+/-0.01. The AUC was improved to 0.88+/-0.01 with the addition of the new features. The improvement was statistically significant (p < 0.001). The study indicated that the new flow dynamic and vascular cross-sectional features were useful for differentiation of NCPs from FPs in cCTA.

  10. Behçet's disease with ruptured anterior communicating artery aneurysm following ruptured thoracic aortic aneurysm.

    PubMed

    Ogata, Atsushi; Kawashima, Masatou; Matsushima, Toshio

    2013-01-01

    A 48-year-old Japanese woman with Behçet's disease suffered successive rupture of thoracic aortic and cerebral aneurysms within one year. The patient underwent successful surgical treatment for both aneurysms. Histological examination of the aneurysm walls revealed lymphocyte infiltration into the adventitia with smooth muscle cell hyperplasia in the thickened intima. This is an extremely unusual presentation of Behçet's disease associated with both cerebral and aortic aneurysms.

  11. Deterministic Multiaxial Creep and Creep Rupture Enhancements for CARES/Creep Integrated Design Code

    NASA Technical Reports Server (NTRS)

    Jadaan, Osama M.

    1998-01-01

    High temperature and long duration applications of monolithic ceramics can place their failure mode in the creep rupture regime. A previous model advanced by the authors described a methodology by which the creep rupture life of a loaded component can be predicted. That model was based on the life fraction damage accumulation rule in association with the modified Monkman-Grant creep rupture criterion. However, that model did not take into account the deteriorating state of the material due to creep damage (e.g., cavitation) as time elapsed. In addition, the material creep parameters used in that life prediction methodology, were based on uniaxial creep curves displaying primary and secondary creep behavior, with no tertiary regime. The objective of this paper is to present a creep life prediction methodology based on a modified form of the Kachanov-Rabotnov continuum damage mechanics (CDM) theory. In this theory, the uniaxial creep rate is described in terms of sum, temperature, time, and the current state of material damage. This scalar damage state parameter is basically an abstract measure of the current state of material damage due to creep deformation. The damage rate is assumed to vary with stress, temperature, time, and the current state of damage itself. Multiaxial creep and creep rupture formulations of the CDM approach are presented in this paper. Parameter estimation methodologies based on nonlinear regression analysis are also described for both, isothermal constant stress states and anisothermal variable stress conditions This creep life prediction methodology was preliminarily added to the integrated design code CARES/Creep (Ceramics Analysis and Reliability Evaluation of Structures/Creep), which is a postprocessor program to commercially available finite element analysis (FEA) packages. Two examples, showing comparisons between experimental and predicted creep lives of ceramic specimens, are used to demonstrate the viability of Ns methodology and the

  12. Hydrocortisone supresses inflammatory activity of metalloproteinase - 8 in carotid plaque

    PubMed Central

    Gabriel, Sthefano Atique; Antonangelo, Leila; Capelozzi, Vera Luiza; Beteli, Camila Baumann; de Camargo Júnior, Otacílio; de Aquino, José Luis Braga; Caffaro, Roberto Augusto

    2015-01-01

    Objective Matrix metalloproteinases are inflammatory biomarkers involved in carotid plaque instability. Our objective was to analyze the inflammatory activity of plasma and carotid plaque MMP-8 and MMP-9 after intravenous administration of hydrocortisone. Methods The study included 22 patients with stenosis ≥ 70% in the carotid artery (11 symptomatic and 11 asymptomatic) who underwent carotid endarterectomy. The patients were divided into two groups: Control Group - hydrocortisone was not administered, and Group 1 - 500 mg intravenous hydrocortisone was administered during anesthetic induction. Plasma levels of MMP-8 and MMP-9 were measured preoperatively (24 hours before carotid endarterectomy) and at 1 hour, 6 hours and 24 hours after