Functional divergence of platelet protein kinase C (PKC) isoforms in thrombus formation on collagen.

Science.gov (United States)

Gilio, Karen; Harper, Matthew T; Cosemans, Judith M E M; Konopatskaya, Olga; Munnix, Imke C A; Prinzen, Lenneke; Leitges, Michael; Liu, Qinghang; Molkentin, Jeffery D; Heemskerk, Johan W M; Poole, Alastair W

2010-07-23

Arterial thrombosis, a major cause of myocardial infarction and stroke, is initiated by activation of blood platelets by subendothelial collagen. The protein kinase C (PKC) family centrally regulates platelet activation, and it is becoming clear that the individual PKC isoforms play distinct roles, some of which oppose each other. Here, for the first time, we address all four of the major platelet-expressed PKC isoforms, determining their comparative roles in regulating platelet adhesion to collagen and their subsequent activation under physiological flow conditions. Using mouse gene knock-out and pharmacological approaches in human platelets, we show that collagen-dependent alpha-granule secretion and thrombus formation are mediated by the conventional PKC isoforms, PKCalpha and PKCbeta, whereas the novel isoform, PKC, negatively regulates these events. PKCdelta also negatively regulates thrombus formation but not alpha-granule secretion. In addition, we demonstrate for the first time that individual PKC isoforms differentially regulate platelet calcium signaling and exposure of phosphatidylserine under flow. Although platelet deficient in PKCalpha or PKCbeta showed reduced calcium signaling and phosphatidylserine exposure, these responses were enhanced in the absence of PKC. In summary therefore, this direct comparison between individual subtypes of PKC, by standardized methodology under flow conditions, reveals that the four major PKCs expressed in platelets play distinct non-redundant roles, where conventional PKCs promote and novel PKCs inhibit thrombus formation on collagen.

Functional Divergence of Platelet Protein Kinase C (PKC) Isoforms in Thrombus Formation on Collagen*

Science.gov (United States)

Gilio, Karen; Harper, Matthew T.; Cosemans, Judith M. E. M.; Konopatskaya, Olga; Munnix, Imke C. A.; Prinzen, Lenneke; Leitges, Michael; Liu, Qinghang; Molkentin, Jeffery D.; Heemskerk, Johan W. M.; Poole, Alastair W.

2010-01-01

Arterial thrombosis, a major cause of myocardial infarction and stroke, is initiated by activation of blood platelets by subendothelial collagen. The protein kinase C (PKC) family centrally regulates platelet activation, and it is becoming clear that the individual PKC isoforms play distinct roles, some of which oppose each other. Here, for the first time, we address all four of the major platelet-expressed PKC isoforms, determining their comparative roles in regulating platelet adhesion to collagen and their subsequent activation under physiological flow conditions. Using mouse gene knock-out and pharmacological approaches in human platelets, we show that collagen-dependent α-granule secretion and thrombus formation are mediated by the conventional PKC isoforms, PKCα and PKCβ, whereas the novel isoform, PKCθ, negatively regulates these events. PKCδ also negatively regulates thrombus formation but not α-granule secretion. In addition, we demonstrate for the first time that individual PKC isoforms differentially regulate platelet calcium signaling and exposure of phosphatidylserine under flow. Although platelet deficient in PKCα or PKCβ showed reduced calcium signaling and phosphatidylserine exposure, these responses were enhanced in the absence of PKCθ. In summary therefore, this direct comparison between individual subtypes of PKC, by standardized methodology under flow conditions, reveals that the four major PKCs expressed in platelets play distinct non-redundant roles, where conventional PKCs promote and novel PKCs inhibit thrombus formation on collagen. PMID:20479008

Genetic analysis of the role of protein kinase Ctheta in platelet function and thrombus formation.

Directory of Open Access Journals (Sweden)

Kellie J Hall

2008-09-01

Full Text Available PKCtheta is a novel protein kinase C isozyme, predominately expressed in T cells and platelets. PKCtheta(-/- T cells exhibit reduced activation and PKCtheta(-/- mice are resistant to autoimmune disease, making PKCtheta an attractive therapeutic target for immune modulation. Collagen is a major agonist for platelets, operating through an immunoreceptor-like signalling pathway from its receptor GPVI. Although it has recently been shown that PKCtheta positively regulates outside-in signalling through integrin alpha(IIbbeta(3 in platelets, the role of PKCtheta in GPVI-dependent signalling and functional activation of platelets has not been assessed.In the present study we assessed static adhesion, cell spreading, granule secretion, integrin alpha(IIbbeta(3 activation and platelet aggregation in washed mouse platelets lacking PKCtheta. Thrombus formation on a collagen-coated surface was assessed in vitro under flow. PKCtheta(-/- platelets exhibited reduced static adhesion and filopodia generation on fibrinogen, suggesting that PKCtheta positively regulates outside-in signalling, in agreement with a previous report. In contrast, PKCtheta(-/- platelets also exhibited markedly enhanced GPVI-dependent alpha-granule secretion, although dense granule secretion was unaffected, suggesting that PKCtheta differentially regulates these two granules. Inside-out regulation of alpha(IIbbeta(3 activation was also enhanced downstream of GPVI stimulation. Although this did not result in increased aggregation, importantly thrombus formation on collagen under high shear (1000 s(-1 was enhanced.These data suggest that PKCtheta is an important negative regulator of thrombus formation on collagen, potentially mediated by alpha-granule secretion and alpha(IIbbeta(3 activation. PKCtheta therefore may act to restrict thrombus growth, a finding that has important implications for the development and safe clinical use of PKCtheta inhibitors.

Development of real-time and quantitative monitoring of thrombus formation in an extracorporeal centrifugal blood pump

Science.gov (United States)

Sakota, Daisuke; Fujiwara, Tatsuki; Ohuchi, Katsuhiro; Kuwana, Katsuyuki; Yamazaki, Hiroyuki; Kosaka, Ryo; Maruyama, Osamu

2018-02-01

We developed an optical detector of thrombus formed on the pivot bearing of an extracorporeal centrifugal blood pump (MERA HCF-MP23; Senko Medical Instrument Mfg. Co., Ltd., Tokyo, Japan) which is frequently used for long-term extracorporeal circulation support to bridge to an implantable artificial heart, which in turn is used for bridge to heart transplantation in Japan. In this study, we investigated the quantitative performance of the thrombus formation in acute animal experiments. A total of three experiments of extracorporeal left ventricular assist using Japanese specific pathogen-free pigs were conducted. The optical fibers were set in the pump driver unit. The incident light at nearinfrared wavelength aiming at the pivot bearing and the resulting scattered light were guided to respective fibers. The detected signal was analyzed to obtain thrombus formation level (TFL) calculated by a specially developed software. When the increase in TFL was confirmed, the pump was exchanged and the extracorporeal circulation was restarted. The number of pump exchanges were four times at each experiment so a total of twelve pumps were evaluated. 3-dimentional data surrounding the pivot bearing and the adhered thrombus was captured by a 3-dimantional surface measurement system to calculate the thrombus surface area (TSA) formed on the pivot bearing. As a result, the correlation coefficient between TFL and TSA was 0.878. The accuracy of TSA estimated by the optical detector was 3.6+/-2.3 mm2. This was small enough to not have the pump exchanged in clinical judgement. The developed detector would be useful for optimal anti-coagulation management.

Multi-Constituent Simulation of Thrombus Deposition.

Science.gov (United States)

Wu, Wei-Tao; Jamiolkowski, Megan A; Wagner, William R; Aubry, Nadine; Massoudi, Mehrdad; Antaki, James F

2017-02-20

In this paper, we present a spatio-temporal mathematical model for simulating the formation and growth of a thrombus. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus (solid) phase. The transport and reactions of 10 chemical and biological species are incorporated using a system of coupled convection-reaction-diffusion (CRD) equations to represent three processes in thrombus formation: initiation, propagation and stabilization. Computational fluid dynamic (CFD) simulations using the libraries of OpenFOAM were performed for two illustrative benchmark problems: in vivo thrombus growth in an injured blood vessel and in vitro thrombus deposition in micro-channels (1.5 mm × 1.6 mm × 0.1 mm) with small crevices (125 μm × 75 μm and 125 μm × 137 μm). For both problems, the simulated thrombus deposition agreed very well with experimental observations, both spatially and temporally. Based on the success with these two benchmark problems, which have very different flow conditions and biological environments, we believe that the current model will provide useful insight into the genesis of thrombosis in blood-wetted devices, and provide a tool for the design of less thrombogenic devices.

Multi-Constituent Simulation of Thrombus Deposition

Science.gov (United States)

Wu, Wei-Tao; Jamiolkowski, Megan A.; Wagner, William R.; Aubry, Nadine; Massoudi, Mehrdad; Antaki, James F.

2017-02-01

In this paper, we present a spatio-temporal mathematical model for simulating the formation and growth of a thrombus. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus (solid) phase. The transport and reactions of 10 chemical and biological species are incorporated using a system of coupled convection-reaction-diffusion (CRD) equations to represent three processes in thrombus formation: initiation, propagation and stabilization. Computational fluid dynamic (CFD) simulations using the libraries of OpenFOAM were performed for two illustrative benchmark problems: in vivo thrombus growth in an injured blood vessel and in vitro thrombus deposition in micro-channels (1.5 mm × 1.6 mm × 0.1 mm) with small crevices (125 μm × 75 μm and 125 μm × 137 μm). For both problems, the simulated thrombus deposition agreed very well with experimental observations, both spatially and temporally. Based on the success with these two benchmark problems, which have very different flow conditions and biological environments, we believe that the current model will provide useful insight into the genesis of thrombosis in blood-wetted devices, and provide a tool for the design of less thrombogenic devices.

Genetic Analysis of the Role of Protein Kinase Cθ in Platelet Function and Thrombus Formation

Science.gov (United States)

Hall, Kellie J.; Harper, Matthew T.; Gilio, Karen; Cosemans, Judith M.; Heemskerk, Johan W. M.; Poole, Alastair W.

2008-01-01

Background PKCθ is a novel protein kinase C isozyme, predominately expressed in T cells and platelets. PKCθ−/− T cells exhibit reduced activation and PKCθ−/− mice are resistant to autoimmune disease, making PKCθ an attractive therapeutic target for immune modulation. Collagen is a major agonist for platelets, operating through an immunoreceptor-like signalling pathway from its receptor GPVI. Although it has recently been shown that PKCθ positively regulates outside-in signalling through integrin αIIbβ3 in platelets, the role of PKCθ in GPVI-dependent signalling and functional activation of platelets has not been assessed. Methodology/Principal Findings In the present study we assessed static adhesion, cell spreading, granule secretion, integrin αIIbβ3 activation and platelet aggregation in washed mouse platelets lacking PKCθ. Thrombus formation on a collagen-coated surface was assessed in vitro under flow. PKCθ−/− platelets exhibited reduced static adhesion and filopodia generation on fibrinogen, suggesting that PKCθ positively regulates outside-in signalling, in agreement with a previous report. In contrast, PKCθ−/− platelets also exhibited markedly enhanced GPVI-dependent α-granule secretion, although dense granule secretion was unaffected, suggesting that PKCθ differentially regulates these two granules. Inside-out regulation of αIIbβ3 activation was also enhanced downstream of GPVI stimulation. Although this did not result in increased aggregation, importantly thrombus formation on collagen under high shear (1000 s−1) was enhanced. Conclusions/Significance These data suggest that PKCθ is an important negative regulator of thrombus formation on collagen, potentially mediated by α-granule secretion and αIIbβ3 activation. PKCθ therefore may act to restrict thrombus growth, a finding that has important implications for the development and safe clinical use of PKCθ inhibitors. PMID:18815612

Inhibition of Hb Binding to GP1bα Abrogates Hb-Mediated Thrombus Formation on Immobilized VWF and Collagen under Physiological Shear Stress.

Science.gov (United States)

Annarapu, Gowtham K; Singhal, Rashi; Peng, Yuandong; Guchhait, Prasenjit

2016-01-01

Reports including our own describe that intravascular hemolysis increases the risk of thrombosis in hemolytic disorders. Our recent study shows that plasma Hb concentrations correlate directly with platelet activation in patients with paroxysmal nocturnal hemoglobinuria (PNH). The binding of Hb to glycoprotein1bα (GP1bα) increases platelet activation. A peptide AA1-50, designed from N-terminal amino acid sequence of GP1bα significantly inhibits the Hb binding to GP1bα as well as Hb-induced platelet activation. This study further examined if the Hb-mediated platelet activation plays any significant role in thrombus formation on subendothelium matrix under physiological flow shear stresses and the inhibition of Hb-platelet interaction can abrogate the above effects of Hb. Study performed thrombus formation assay in vitro by perfusing whole blood over immobilized VWF or collagen type I in presence of Hb under shear stresses simulating arterial or venous flow. The Hb concentrations ranging from 5 to 10 μM, commonly observed level in plasma of the hemolytic patients including PNH, dose-dependently increased thrombus formation on immobilized VWF under higher shear stress of 25 dyne/cm2, but not at 5 dyne/cm2. The above Hb concentrations also increased thrombus formation on immobilized collagen under both shear stresses of 5 and 25 dyne/cm2. The peptide AA1-50 abrogated invariably the above effects of Hb on thrombus formation. This study therefore indicates that the Hb-induced platelet activation plays a crucial role in thrombus formation on immobilized VWF or collagen under physiological flow shear stresses. Thus suggesting a probable role of this mechanism in facilitating thrombosis under hemolytic conditions.

Importance of Endogenous Fibrinolysis in Platelet Thrombus Formation.

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Gue, Ying X; Gorog, Diana A

2017-08-25

The processes of thrombosis and coagulation are finely regulated by endogenous fibrinolysis maintaining healthy equilibrium. When the balance is altered in favour of platelet activation and/or coagulation, or if endogenous fibrinolysis becomes less efficient, pathological thrombosis can occur. Arterial thrombosis remains a major cause of morbidity and mortality in the world despite advances in medical therapies. The role endogenous fibrinolysis in the pathogenesis of arterial thrombosis has gained increasing attention in recent years as it presents novel ways to prevent and treat existing diseases. In this review article, we discuss the role of endogenous fibrinolysis in platelet thrombus formation, methods of measurement of fibrinolytic activity, its role in predicting cardiovascular diseases and clinical outcomes and future directions.

White Thrombus Formation in Blood Tubing Lines in a Chronic Hemodialysis Unit

OpenAIRE

Watnick, Suzanne; Stooksbury, Michael; Winter, Rolf; Riscoe, Michael; Cohen, David M.

2008-01-01

Background and objectives: Previous reports have described white particulate matter in banked blood components, but no prior public reports describe such matter in blood tubing during the course of routine in-center hemodialysis. This report describes the events, investigations, and preliminary conclusions associated with the spontaneous formation of adherent white thrombus in the venous and arterial blood lines during routine in-center hemodialysis treatments.

Complementary roles of platelets and coagulation in thrombus formation on plaques acutely ruptured by targeted ultrasound treatment: a novel intravital model.

Science.gov (United States)

Kuijpers, M J E; Gilio, K; Reitsma, S; Nergiz-Unal, R; Prinzen, L; Heeneman, S; Lutgens, E; van Zandvoort, M A M J; Nieswandt, B; Egbrink, M G A Oude; Heemskerk, J W M

2009-01-01

Atherothrombosis is a major cause of cardiovascular events. However, animal models to study this process are scarce. We describe the first murine model of acute thrombus formation upon plaque rupture to study atherothrombosis by intravital fluorescence microscopy. Localized rupture of an atherosclerotic plaque in a carotid artery from Apoe(-/-) mice was induced in vivo using ultrasound. Rupture of the plaque and formation of localized thrombi were verified by two-photon laser scanning microscopy (TPLSM) in isolated arteries, and by immunohistochemistry. The thrombotic reaction was quantified by intravital fluorescence microscopy. Inspection of the ultrasound-treated plaques by histochemistry and TPLSM demonstrated local damage, collagen exposure, luminal thrombus formation as well as intra-plaque intrusion of erythrocytes and fibrin. Ultrasound treatment of healthy carotid arteries resulted in endothelial damage and limited platelet adhesion. Real-time intravital fluorescence microscopy demonstrated rapid platelet deposition on plaques and formation of a single thrombus that remained subocclusive. The thrombotic process was antagonized by thrombin inhibition, or by blocking of collagen or adenosine diphosphate receptor pathways. Multiple thrombi were formed in 70% of mice lacking CD40L. Targeted rupture of murine plaques results in collagen exposure and non-occlusive thrombus formation. The thrombotic process relies on platelet activation as well as on thrombin generation and coagulation, and is sensitive to established and novel antithrombotic medication. This model provides new possibilities to study atherothrombosis in vivo.

Multi-parameter assessment of thrombus formation on microspotted arrays of thrombogenic surfaces

OpenAIRE

sprotocols

2014-01-01

Authors: Susanne de Witt, Frauke Swieringa, Judith Cosemans & Johan Heemskerk ### Abstract Thrombus formation by adhering and aggregating blood platelets is fundamental to hemostasis and is a prerequisite for vascular occlusion in pathological thrombosis. The parallel-plate flow chamber technique has been extensively used to measure platelet adhesion and activation in vitro at arterial or venous flow conditions. Here, we describe the use of brightfield and confocal fluorescence micros...

Critical role of FcR gamma-chain, LAT, PLCgamma2 and thrombin in arteriolar thrombus formation upon mild, laser-induced endothelial injury in vivo.

Science.gov (United States)

Kalia, Neena; Auger, Jocelyn M; Atkinson, Ben; Watson, Steve P

2008-05-01

The role of collagen receptor complex GPVI-FcR gamma-chain, PLCgamma2 and LAT in laser-induced thrombosis is unclear. Controversy surrounds whether collagen is exposed in this model or whether thrombosis is dependent on thrombin. This study hypothesized that collagen exposure plays a critical role in thrombus formation in this model, which was tested by investigating contributions of FcR gamma-chain, LAT, PLCgamma2 and thrombin. Thrombi were monitored using intravital microscopy in anesthetized wild-type and FcR gamma-chain, LAT and PLCgamma2 knockout mice. Hirudin (thrombin inhibitor) was administered to wild-type and FcR gamma-chain knockout mice. Significantly reduced thrombus formation was observed in FcR gamma-chain and PLCgamma2 knockouts with a greater decrease observed in LAT knockouts. Dramatic reduction was observed in wild-types treated with hirudin, with abolished thrombus formation only observed in FcR gamma-chain knockouts treated with hirudin. GPVI-FcR gamma-chain, LAT and PLCgamma2 are essential for thrombus generation and stability in this laser-induced model of injury. More importantly, a greater role for LAT was identified, which may reflect a role for it downstream of a second matrix protein receptor. However, inhibition of platelet activation by matrix proteins and thrombin generation are both required to maximally prevent thrombus formation.

Non-redundant roles of phosphoinositide 3-kinase isoforms alpha and beta in glycoprotein VI-induced platelet signaling and thrombus formation.

Science.gov (United States)

Gilio, Karen; Munnix, Imke C A; Mangin, Pierre; Cosemans, Judith M E M; Feijge, Marion A H; van der Meijden, Paola E J; Olieslagers, Servé; Chrzanowska-Wodnicka, Magdalena B; Lillian, Rivka; Schoenwaelder, Simone; Koyasu, Shigeo; Sage, Stewart O; Jackson, Shaun P; Heemskerk, Johan W M

2009-12-04

Platelets are activated by adhesion to vascular collagen via the immunoglobulin receptor, glycoprotein VI (GPVI). This causes potent signaling toward activation of phospholipase Cgamma2, which bears similarity to the signaling pathway evoked by T- and B-cell receptors. Phosphoinositide 3-kinase (PI3K) plays an important role in collagen-induced platelet activation, because this activity modulates the autocrine effects of secreted ADP. Here, we identified the PI3K isoforms directly downstream of GPVI in human and mouse platelets and determined their role in GPVI-dependent thrombus formation. The targeting of platelet PI3Kalpha or -beta strongly and selectively suppressed GPVI-induced Ca(2+) mobilization and inositol 1,4,5-triphosphate production, thus demonstrating enhancement of phospholipase Cgamma2 by PI3Kalpha/beta. That PI3Kalpha and -beta have a non-redundant function in GPVI-induced platelet activation and thrombus formation was concluded from measurements of: (i) serine phosphorylation of Akt, (ii) dense granule secretion, (iii) intracellular Ca(2+) increases and surface expression of phosphatidylserine under flow, and (iv) thrombus formation, under conditions where PI3Kalpha/beta was blocked or p85alpha was deficient. In contrast, GPVI-induced platelet activation was insensitive to inhibition or deficiency of PI3Kdelta or -gamma. Furthermore, PI3Kalpha/beta, but not PI3Kgamma, contributed to GPVI-induced Rap1b activation and, surprisingly, also to Rap1b-independent platelet activation via GPVI. Together, these findings demonstrate that both PI3Kalpha and -beta isoforms are required for full GPVI-dependent platelet Ca(2+) signaling and thrombus formation, partly independently of Rap1b. This provides a new mechanistic explanation for the anti-thrombotic effect of PI3K inhibition and makes PI3Kalpha an interesting new target for anti-platelet therapy.

Deep venous thrombus characterization: ultrasonography, elastography and scattering operator

OpenAIRE

Thibaud Berthomier; Ali Mansour; Luc Bressollette; Frédéric Le Roy; Dominique Mottier

2017-01-01

A thrombus or a blood clot is the result of blood coagulation which is a natural process to prevent bleeding. An inappropriate formation of a thrombus in a deep vein is known as Deep Venous Thrombosis (DVT). The main complication of a DVT is a Pulmonary Embolism (PE) which occurs when a thrombus breaks loose and travels to the lungs. DVT, PE, or both are also known as Venous thromboembolism (VTE). It affects an estimated 300,000–600,000 Individuals just in the United States per year and can c...

White thrombus formation in blood tubing lines in a chronic hemodialysis unit.

Science.gov (United States)

Watnick, Suzanne; Stooksbury, Michael; Winter, Rolf; Riscoe, Michael; Cohen, David M

2008-03-01

Previous reports have described white particulate matter in banked blood components, but no prior public reports describe such matter in blood tubing during the course of routine in-center hemodialysis. This report describes the events, investigations, and preliminary conclusions associated with the spontaneous formation of adherent white thrombus in the venous and arterial blood lines during routine in-center hemodialysis treatments. Design setting, participants, & measurements: This investigation occurred at the Portland Veterans Administration Medical Center (PVAMC) Hemodialysis Unit from October 2006 through April 2007. Sixty-eight variables regarding demographics, medical history and dialysis treatments were collected on our 34 chronic hemodialysis outpatients. Over a 5-wk interval, 62% (21 of 34) of the chronic hemodialysis patients unexpectedly developed a white precipitate adhering to the lumenal surface of their dialysis blood tubing, with 73 of 580 chronic dialysis treatments exhibiting the phenomenon. Microscopic and biochemical analyses were consistent with white thrombus, formed by an aggregation of platelets and fibrin. An alert was issued and other in-center hemodialysis units noted similar findings. This was remedied by the removal of specific tubing. Both patient-specific and tubing-specific factors may have been operative. Although patient safety was not adversely affected, assessment of clinical and manufacturing variables potentially affecting platelet activation is warranted.

Protein kinase C mediates platelet secretion and thrombus formation through protein kinase D2.

Science.gov (United States)

Konopatskaya, Olga; Matthews, Sharon A; Harper, Matthew T; Gilio, Karen; Cosemans, Judith M E M; Williams, Christopher M; Navarro, Maria N; Carter, Deborah A; Heemskerk, Johan W M; Leitges, Michael; Cantrell, Doreen; Poole, Alastair W

2011-07-14

Platelets are highly specialized blood cells critically involved in hemostasis and thrombosis. Members of the protein kinase C (PKC) family have established roles in regulating platelet function and thrombosis, but the molecular mechanisms are not clearly understood. In particular, the conventional PKC isoform, PKCα, is a major regulator of platelet granule secretion, but the molecular pathway from PKCα to secretion is not defined. Protein kinase D (PKD) is a family of 3 kinases activated by PKC, which may represent a step in the PKC signaling pathway to secretion. In the present study, we show that PKD2 is the sole PKD member regulated downstream of PKC in platelets, and that the conventional, but not novel, PKC isoforms provide the upstream signal. Platelets from a gene knock-in mouse in which 2 key phosphorylation sites in PKD2 have been mutated (Ser707Ala/Ser711Ala) show a significant reduction in agonist-induced dense granule secretion, but not in α-granule secretion. This deficiency in dense granule release was responsible for a reduced platelet aggregation and a marked reduction in thrombus formation. Our results show that in the molecular pathway to secretion, PKD2 is a key component of the PKC-mediated pathway to platelet activation and thrombus formation through its selective regulation of dense granule secretion.

Deep venous thrombus characterization: ultrasonography, elastography and scattering operator

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Thibaud Berthomier

2017-04-01

Full Text Available A thrombus or a blood clot is the result of blood coagulation which is a natural process to prevent bleeding. An inappropriate formation of a thrombus in a deep vein is known as Deep Venous Thrombosis (DVT. The main complication of a DVT is a Pulmonary Embolism (PE which occurs when a thrombus breaks loose and travels to the lungs. DVT, PE, or both are also known as Venous thromboembolism (VTE. It affects an estimated 300,000–600,000 Individuals just in the United States per year and can cause considerable morbidity and mortality. This multifactorial disease related to advanced age, immobility, surgery or obesity is an important public health issue. Our project is looking to link the VTE epidemiology (risk factors, patient history, PE to the thrombus structure. To reach our goals, we are collecting ultrasonography (echogenicity and elastography (stiffness of human thrombus. This manuscript describes our approach to create and preprocess a database using Toshiba Aplio 500. Our approaches to characterize the thrombus structure with ultrasound images are also described. The feature extraction is made with the scattering operator. Obtained features are then reduced using Principal Component Analysis and are analyzed to evaluate our approach.

Complementary roles of platelets and coagulation in thrombus formation on plaques acutely ruptured by targeted ultrasound treatment: a novel intravital model

NARCIS (Netherlands)

Kuijpers, M. J. E.; Gilio, K.; Reitsma, S.; Nergiz-Unal, R.; Prinzen, L.; Heeneman, S.; Lutgens, E.; van Zandvoort, M. A. M. J.; Nieswandt, B.; Egbrink, M. G. A. Oude; Heemskerk, J. W. M.

2009-01-01

Atherothrombosis is a major cause of cardiovascular events. However, animal models to study this process are scarce. We describe the first murine model of acute thrombus formation upon plaque rupture to study atherothrombosis by intravital fluorescence microscopy. Localized rupture of an

Glaucocalyxin A inhibits platelet activation and thrombus formation preferentially via GPVI signaling pathway.

Directory of Open Access Journals (Sweden)

Wei Li

Full Text Available Platelets play a pivotal role in atherothrombosis and the antiplatelet agents have been proved to be useful in preventing onset of acute clinical events including myocardial infarction and stroke. Increasing number of natural compounds has been identified to be potential antiplatelet agents. Here we report the antiplatelet effect of glaucocalyxin A (GLA, an ent-diterpenoid that we isolated and purified from the aerial parts of Rabdosia japonica (Burm. f. var. glaucocalyx (Maxim. Hara, and investigate the molecular mechanisms by which GLA inhibits platelet activation and thrombus formation. The effect of GLA on platelet activation was measured using platelets freshly isolated from peripheral blood of healthy donors. Results showed that pretreatment of human platelets with lower concentrations of GLA (0.01 μg/ml, 0.1 μg/ml significantly inhibited platelet aggregation induced by collagen (P<0.001 and CRP (P<0.01, a synthetic GPVI ligand, but not by ADP and U46619. Accordingly, GLA inhibited collagen-stimulated tyrosine phosphorylation of Syk, LAT, and phospholipase Cγ2, the signaling events in collagen receptor GPⅥ pathway. GLA also inhibited platelet p-selectin secretion and integrin activation by convulxin, a GPVI selective ligand. Additionally, GLA was found to inhibit low-dose thrombin-induced platelet activation. Using a flow chamber device, GLA was found to attenuate platelet adhesion on collagen surfaces in high shear condition. In vivo studies showed that GLA administration increased the time for complete occlusion upon vascular injury in mice, but did not extend tail-bleeding time when mice were administered with relatively lower doses of GLA. Therefore, the present results provide the molecular basis for the inhibition effect of GLA on platelet activation and its in vivo effect on thrombus formation, suggesting that GLA could potentially be developed as an antiplatelet and antithrombotic agent.

Method of cell transplantation promoting the organization of intraarterial thrombus.

Science.gov (United States)

Hirano, Koji; Shimono, Takatsugu; Imanaka-Yoshida, Kyoko; Miyamoto, Keiichi; Fujinaga, Kazuya; Kajimoto, Masaki; Miyake, Yoichiro; Nishikawa, Masakatsu; Yoshida, Toshimichi; Uchida, Atsumasa; Shimpo, Hideto; Yada, Isao; Hirata, Hitoshi

2005-08-30

Endovascular aortic repairs have been developed as less invasive treatments for aortic aneurysms. Some aneurismal cavities, however, remain without organization, causing a re-expansion of the aneurysms. We studied cell transplantation into the aneurismal sac to promote the organization of thrombus for the complete healing of aneurysms. Skin fibroblasts and skeletal myoblasts were isolated from rats for cell transplantation. An intraarterial thrombus model was made by ligation of the carotid artery. Culture medium (medium group, n=11), collagen gel (gel group, n=11), fibroblasts with collagen gel (F group, n=15), myoblasts with collagen gel (M group, n=12), or mixture of fibroblasts and myoblasts with collagen gel (F+M group, n=14) were injected into the thrombus. After 28 days, histologically, the arterial lumens of the F and M groups were partly filled with fibrous tissues, whereas in the F+M group organization was almost completed and luminal sizes diminished. Immunohistochemical staining demonstrated that alpha-smooth muscle actin-positive cells were more abundantly contained in the organized area of the F+M group than in the other groups. We also analyzed cellular function in vitro with immunofluorescence; coculture of fibroblasts and myoblasts showed that the fraction of alpha-smooth muscle actin-positive fibroblasts increased. This phenomenon accounts for the rapid organization of thrombus in the F+M group in vivo. Cell transplantation accelerated thrombus organization. Especially, myoblasts enhanced differentiation of fibroblasts into myofibroblasts, contributing to rapid thrombus organization. Cell transplantation into unorganized spaces seems applicable to endovascular treatment of aneurysms.

The effect of factor VIII deficiencies and replacement and bypass therapies on thrombus formation under venous flow conditions in microfluidic and computational models.

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Abimbola A Onasoga-Jarvis

Full Text Available Clinical evidence suggests that individuals with factor VIII (FVIII deficiency (hemophilia A are protected against venous thrombosis, but treatment with recombinant proteins can increase their risk for thrombosis. In this study we examined the dynamics of thrombus formation in individuals with hemophilia A and their response to replacement and bypass therapies under venous flow conditions. Fibrin and platelet accumulation were measured in microfluidic flow assays on a TF-rich surface at a shear rate of 100 s⁻¹. Thrombin generation was calculated with a computational spatial-temporal model of thrombus formation. Mild FVIII deficiencies (5-30% normal levels could support fibrin fiber formation, while severe (1 nM, but too low to support fibrin formation (<10 nM. In the absence of platelets, fibrin formation was not supported even at normal FVIII levels, suggesting platelet adhesion is necessary for fibrin formation. Individuals treated by replacement therapy, recombinant FVIII, showed normalized fibrin formation. Individuals treated with bypass therapy, recombinant FVIIa, had a reduced lag time in fibrin formation, as well as elevated fibrin accumulation compared to healthy controls. Treatment of rFVIIa, but not rFVIII, resulted in significant changes in fibrin dynamics that could lead to a prothrombotic state.

Successful catheter directed thrombolysis of IVC and renal vein occlusive thrombus.

LENUS (Irish Health Repository)

McCarthy, E

2011-11-01

Thrombus formation is a recognised complication of IVC filter placement, however IVC and bilateral renal vein occlusion secondary to thrombus is much less common. We present a case of infrahepatic caval and bilateral renal vein occlusion secondary to thrombosis of a suprarenal IVC filter. With progressive clinical deterioration and failure of conservative medical management the patient underwent successful mechanical disruption and catheter directed thrombolysis.

Motion of left atrial appendage as a determinant of thrombus formation in patients with a low CHADS2 score receiving warfarin for persistent nonvalvular atrial fibrillation

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Ono Koji

2012-12-01

Full Text Available Abstract Background The aim of this study was to define the independent determinants of left atrial appendage (LAA thrombus among various echocardiographic parameters measured by Velocity Vector Imaging (VVI in patients with nonvalvular atrial fibrillation (AF receiving warfarin, particularly in patients with a low CHADS2 score. Methods LAA emptying fraction (EF and LAA peak longitudinal strain were measured by VVI using transesophageal echocardiography in 260 consecutive patients with nonvalvular persistent AF receiving warfarin. The patients were divided into two groups according to the presence (n=43 or absence (n=217 of LAA thrombus. Moreover, the patients within each group were further divided into subgroups according to a CHADS2 score ≤1. Results Multivariate logistic regression analysis showed that LAAEF was an independent determinant of LAA thrombus in the subgroup of 140 with a low CHADS2 score. Receiver operating characteristics curve analysis showed that an LAAEF of 21% was the optimal cutoff value for predicting LAA thrombus. Conclusions LAA thrombus formation depended on LAA contractility. AF patients with reduced LAA contractile fraction (LAAEF ≤21% require strong anticoagulant therapy to avoid thromboembolic events regardless of a low CHADS2 score (≤1.

Frequency of left ventricular thrombus after anterior wall st-segment elevation acute myocardial infarction

International Nuclear Information System (INIS)

Iqbal, M.W.; Fayyaz, A.

2014-01-01

Left ventricular thrombus (LVT) formation is a well known complication seen in patients presenting with acute anterior wall ST-segment elevation myocardial infarction (STEMI). In previous studies the incidence of this complication, after acute myocardial infarction (AMI) has been reported to be 4% to 60% in large anterior wall STEMI, depending significantly upon the method as well as time of reperfusion therapy after STEMI. Objective: The objective of this descriptive case series study was to evaluate the frequency of left ventricular thrombus formation in patients after acute anterior wall ST-Segment elevation myocardial infarction. Methodology: In this study, 100 patients with anterior wall STEMI presenting to cardiac emergency or coronary care unit (CCU) of Cardiac complex, Gulab Devi Hospital, were selected on non-probability, purposive sampling meeting inclusion criteria, after taking written informed consent. All the patients were treated initially for management of acute STEMI, including use of thrombolytics where indicated. 2-D Transthoracic echocardiography (TTE) was performed during the same admission to assess presence of LV thrombus (LVT). Results: The mean age of the patients was 54.3 +- 11.4 years. There were 84(84%) male patients and 16 (16%) female patients. LVT was present in 28 (28%) patients on TTE. Among those, there were 23 (82.1%) male and 5 (17.9%) female patients. However, out of 84 male patients 27.4% develop LVT and among 16 female patients this ratio was 31.3%. The LV thrombus was independent of age and gender. LV thrombus was significantly less in thrombolytic group as compared to those who were not given this therapy, i.e. p value <0.05. Conclusion: Patients with anterior wall acute STEMI not infrequently develop the complication of development of LV thrombus. In this study the frequency of LV thrombus formation after anterior wall acute STEMI was 28%. (author)

Platelet endothelial cell adhesion molecule 1 deficiency misguides venous thrombus resolution.

Science.gov (United States)

Kellermair, Joerg; Redwan, Bassam; Alias, Sherin; Jabkowski, Joerg; Panzenboeck, Adelheid; Kellermair, Lukas; Winter, Max P; Weltermann, Ansgar; Lang, Irene M

2013-11-07

Platelet endothelial cell adhesion molecule 1 (PECAM-1) is involved in leukocyte migration and angiogenesis, which are key components of venous thrombus resolution. This study investigated the effect of PECAM-1 deficiency on thrombus resolution in FVB/n mice and the extent to which levels of soluble PECAM-1 (sPECAM-1) correlate with delayed thrombus resolution in humans after acute symptomatic deep vein thrombosis (DVT). In a mouse stagnant flow venous thrombosis model Pecam-1(-/-) thrombi were larger, persisted for longer periods of time, and displayed attenuated macrophage invasion and decreased vessel formation in the presence of increased fibrosis. In humans, higher levels of truncated plasma sPECAM-1 possibly cleaved from cell surfaces, were found in patients with delayed thrombus resolution (assessed via duplex-based thrombus scoring) relative to those whose thrombi resolved (median, 25th/75th percentile): 92.5 (87.7/103.4) ng/mL vs 71.5 (51.1/81.0) ng/mL; P deep vein thrombus specimens stained positively with antibodies specific for the extracellular, but not the cytoplasmic domain of PECAM-1, consistent with accumulation of cleaved PECAM-1. Our data suggest a regulatory role of PECAM-1 in venous thrombus resolution and suggest a predictive value of sPECAM-1 for postthrombotic syndrome (PTS) after acute DVT.

Evaluation of radiocolloids as thrombus imaging agents. Effect of particle size on thrombus uptake

Energy Technology Data Exchange (ETDEWEB)

Rosenthal, S.N.; Bardfeld, P.A.

1985-01-01

Thrombus uptake values of several /sup 99m/Tc labeled radiocolloids determined using an experimental rodent model of deep venous thrombosis were correlated with particle size distributions. The thrombus uptake values increased with increasing mean particle size. The /sup 99m/Tc-tin colloid had the highest thrombus uptake value of any of the colloids used in this study.

Recanalization and flow regulate venous thrombus resolution and Matrix metalloproteinases expression in vivo

Science.gov (United States)

Chabasse, Christine; Siefert, Suzanne A.; Chaudry, Mohammed; Hoofnagle, Mark H.; Lal, Brajesh K.; Sarkar, Rajabrata

2016-01-01

Objective We examined the role of thrombus recanalization and ongoing blood flow in the process of thrombus resolution by comparing two murine in vivo models of deep venous thrombosis. Design of study In CD1 mice, we performed surgical inferior vena cava (IVC) ligation (stasis thrombosis), stenosis (thrombosis with recanalization) or sham procedure. We analyzed thrombus weight over time as a measure of thrombus resolution, and quantified the mRNA and protein levels of Membrane-Type Matrix Metalloproteinases (MT-MMPs) as well as effectors of the plasmin complex at day 4, 8 and 12 post-surgery. Results Despite similar initial thrombus size, the presence of ongoing blood flow (stenosis model) was associated with a 45.91% subsequent improvement in thrombus resolution at day 8, and 12.57% at day 12, as compared with stasis thrombosis (ligation model). Immunoblot and real-time PCR demonstrated a difference in MMP-2 and MMP-9 activity at day 8 between the two models (P=.03 and P=.006 respectively), as well as a difference in MT2-MMP gene expression at day 8 (P=.044) and day 12 (P=0.03) and MT1-MMP protein expression at day 4 (P=.021). Histological analyses revealed distinct areas of recanalization in the thrombi of the stenosis model compared to the ligation model, as well as the recruitment of inflammatory cells, especially macrophages, and a focal pattern of localized expression of MT1-MMP and MT3-MMP proteins surrounding the areas of recanalization in the stenosis model. Conclusions Recanalization and ongoing blood flow accelerate deep venous thrombus resolution in vivo, and are associated with distinct patterns of MT1- and MT3-MMP expression and macrophages localization in areas of intra-thrombus recanalization. PMID:26993683

Analysis of early thrombus dynamics in a humanized mouse laser injury model.

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Wang, Weiwei; Lindsey, John P; Chen, Jianchun; Diacovo, Thomas G; King, Michael R

2014-01-01

Platelet aggregation and thrombus formation at the site of injury is a dynamic process that involves the continuous addition of new platelets as well as thrombus rupture. In the early stages of hemostasis (within minutes after vessel injury) this process can be visualized by transfusing fluorescently labeled human platelets and observing their deposition and detachment. These two counterbalancing events help the developing thrombus reach a steady-state morphology, where it is large enough to cover the injured vessel surface but not too large to form a severe thrombotic occlusion. In this study, the spatial and temporal aspects of early stage thrombus dynamics which result from laser-induced injury on arterioles of cremaster muscle in the humanized mouse were visualized using fluorescent microscopy. It was found that rolling platelets show preference for the upstream region while tethering/detaching platelets were primarily found downstream. It was also determined that the platelet deposition rate is relatively steady, whereas the effective thrombus coverage area does not increase at a constant rate. By introducing a new method to graphically represent the real time in vivo physiological shear stress environment, we conclude that the thrombus continuously changes shape by regional growth and decay, and neither dominates in the high shear stress region.

Assessment of mitral annular velocities by Doppler tissue imaging in predicting left ventricular thrombus formation after first anterior acute myocardial infarction

Directory of Open Access Journals (Sweden)

Ahmed Fathy

2011-09-01

Conclusion: From our study, we can conclude that TDE can be used for estimation of systolic and diastolic functions of LV and hence identification of patients at high risk for LV thrombus formation after first time acute anterior myocardial infarction and we recommend more studies to support our results about the importance of the role of oral anticoagulant after AMI.

Mural Thrombus in the Normal-Appearing Descending Thoracic Aorta of a Chronic Smoker

Science.gov (United States)

Habib, Habib; Hsu, Judy; Winchell, Patricia Jo; Daoko, Joseph

2013-01-01

Thrombus formation in an atherosclerotic or aneurysmal descending thoracic aorta is a well-described, frequently encountered vascular condition. In comparison, thrombus formation in a normal-appearing descending thoracic aorta is reported far less often. We describe the case of a 46-year-old woman who had splenic and renal infarctions secondary to embolic showers from a large, mobile thrombus in a morphologically normal proximal descending thoracic aorta. After the patient underwent anticoagulation, stent-grafting, and surgical bypass to correct an arterial blockage caused by the stent-graft, she resumed a relatively normal life. In contrast with other cases of a thrombotic but normal-appearing descending thoracic aorta, this patient had no known malignancy or systemic coagulative disorders; her sole risk factor was chronic smoking. We discuss our patient's case and review the relevant medical literature, focusing on the effect of smoking on coagulation physiology. PMID:24391341

Thrombus aspiration catheter is a Dottering balloon

Directory of Open Access Journals (Sweden)

D. Sheshagiri Rao

2016-07-01

Full Text Available Coronary angiogram in a young man with history of STEMI with delayed presentation revealed subtotal occlusion of left anterior descending artery (LAD with large thrombotic filling defect distal to the critical lesion. PCI was preferred without delay because of ongoing chest pain. Several runs of thrombus aspiration failed to detect any visible thrombus. However, the immediate angiogram after thrombus aspiration showed complete distal embolization of the thrombus which could have been achieved by Dottering or balloon dilatation. In contrary to the general perception, does thrombus aspiration push more thrombus than it can aspirate?

Recent Inferior Myocardial Infarction Complicated with a Right Ventricular Thrombus Detected by Three Cardiac Imaging Modalities.

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Kuno, Toshiki; Imaeda, Syohei; Hashimoto, Kenji; Ryuzaki, Toshinobu; Saito, Tetsuya; Yamazaki, Hiroyuki; Tabei, Ryota; Kodaira, Masaki; Hase, Manabu; Numasawa, Yohei

2018-03-01

We report the case of a 71-year-old woman diagnosed with recent inferior myocardial infarction complicated with right ventricular infarction and a right ventricular thrombus. Three-dimensional transthoracic echocardiography, contrast-enhanced computed tomography, and cardiac magnetic resonance imaging clearly detected a thrombus. We consider cases with a recent right ventricular infarction to require assessment for thrombus formations in the right ventricle. Fortunately, vigorous anticoagulation therapy resolved the thrombi in both the right ventricle and right coronary artery.

Higher levels of serum fibrin-monomer reflect hypercoagulable state and thrombus formation in the left atrial appendage in patients with acute ischemic stroke.

Science.gov (United States)

Okuyama, Hidenobu; Hirono, Osamu; Liu, Ling; Takeishi, Yasuchika; Kayama, Takamasa; Kubota, Isao

2006-08-01

It is sometimes difficult to make a diagnosis of cardioembolic stroke in the stroke care unit, because of the splashing and vanishing of the intracardiac source of the emboli on transesophageal echocardiography. Serum fibrin-monomer (FM) is a new marker for coagulation activity that is useful for identifying older individuals at increased risk of ischemic stroke. Two hundred and four patients with acute ischemic stroke were examined for serum coagulation and fibrinolytic activity on admission, and underwent transesophageal echocardiography within 7 days of onset. Serum levels of FM was significantly higher in patients with left atrial appendage (LAA) thrombus formation (n=24) than in those with no thrombus (88+/-52 vs 14+/-9 microg/ml, pvs 8+/-5 microg/ml, pstroke.

Thrombus aspiration catheter is a Dottering balloon.

Science.gov (United States)

Sheshagiri Rao, D; Barik, Ramachandra; Prasad, Akula Siva

2016-01-01

Coronary angiogram in a young man with history of STEMI with delayed presentation revealed subtotal occlusion of left anterior descending artery (LAD) with large thrombotic filling defect distal to the critical lesion. PCI was preferred without delay because of ongoing chest pain. Several runs of thrombus aspiration failed to detect any visible thrombus. However, the immediate angiogram after thrombus aspiration showed complete distal embolization of the thrombus which could have been achieved by Dottering or balloon dilatation. In contrary to the general perception, does thrombus aspiration push more thrombus than it can aspirate? Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

β2-glycoprotein-1 autoantibodies from patients with antiphospholipid syndrome are sufficient to potentiate arterial thrombus formation in a mouse model

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Arad, Ariela; Proulle, Valerie; Furie, Richard A.; Furie, Barbara C.

2011-01-01

Antiphospholipid syndrome is characterized by thrombosis, recurrent fetal loss, and the presence of the lupus anticoagulant, anticardiolipin antibodies, or anti–β2-glycoprotein-1 (anti–β2-GP1) antibodies. Although anti–β2-GP1 antibodies have been documented as a biomarker for diagnosis of antiphospholipid syndrome, their direct role in the pathogenesis of thrombosis is unknown. We have demonstrated using intravital microscopy that anti–β2-GP1 autoantibodies purified from the sera of patients with antiphospholipid syndrome complicated by thrombosis greatly amplify thrombus size after laser-induced vessel wall injury in live mice. Anti–β2-GP1 autoantibodies from 3 patients with antiphospholipid syndrome were affinity-purified using human β2-GP1 bound to agarose. The effects of purified anti–β2-GP1 IgG autoantibodies, of anti–β2-GP1–depleted IgG, and of IgG from normal human sera on thrombus formation were measured in mice after arterial injury in the cremaster muscle. Before injury, purified anti–β2-GP1 IgG autoantibodies, anti–β2-GP1 antibody–depleted IgG, or IgG from normal human sera were infused. Increasing amounts of purified anti–β2-GP1 autoantibodies increased thrombus size in a dose-dependent manner, whereas neither anti–β2-GP1 antibody-depleted IgG nor IgG from normal serum affected thrombus size. These results indicate that anti–β2-GP1 IgG autoantibodies in antiphospholipid syndrome patient sera are not only a marker of antiphospholipid syndrome but are directly involved in the pathogenesis of thrombosis. PMID:21245481

Recanalization and flow regulate venous thrombus resolution and matrix metalloproteinase expression in vivo.

Science.gov (United States)

Chabasse, Christine; Siefert, Suzanne A; Chaudry, Mohammed; Hoofnagle, Mark H; Lal, Brajesh K; Sarkar, Rajabrata

2015-01-01

We examined the role of thrombus recanalization and ongoing blood flow in the process of thrombus resolution by comparing two murine in vivo models of deep venous thrombosis. In CD1 mice, we performed surgical inferior vena cava ligation (stasis thrombosis), stenosis (thrombosis with recanalization), or sham procedure. We analyzed thrombus weight over time as a measure of thrombus resolution and quantified the messenger RNA and protein levels of membrane-type matrix metalloproteinases (MT-MMPs) as well as effectors of the plasmin complex at days 4, 8, and 12 after surgery. Despite similar initial thrombus size, the presence of ongoing blood flow (stenosis model) was associated with a 45.91% subsequent improvement in thrombus resolution at day 8 and 12.57% at day 12 compared with stasis thrombosis (ligation model). Immunoblot and real-time polymerase chain reaction analysis demonstrated a difference in MMP-2 and MMP-9 activity at day 8 between the two models (P = .03 and P = .006, respectively) as well as a difference in MT2-MMP gene expression at day 8 (P = .044) and day 12 (P = .03) and MT1-MMP protein expression at day 4 (P = .021). Histologic analyses revealed distinct areas of recanalization in the thrombi of the stenosis model compared with the ligation model as well as the recruitment of inflammatory cells, especially macrophages, and a focal pattern of localized expression of MT1-MMP and MT3-MMP proteins surrounding the areas of recanalization in the stenosis model. Recanalization and ongoing blood flow accelerate deep venous thrombus resolution in vivo and are associated with distinct patterns of MT1-MMP and MT3-MMP expression and macrophage localization in areas of intrathrombus recanalization. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Antibody-targeted thrombus imaging and thrombolysis

International Nuclear Information System (INIS)

Wu Guoxin; Ruan Changgeng

1993-05-01

In respect of thrombus imaging, the femoral arterial or venous thrombus model was prepared in dogs and imaged with single photon emission computerized tomography (SPECT). After 4 hours of injection of 131 I-SZ-51 the radioactivity ratio between thrombus and blood (T/B) was 18 : 1 and 8 : 1 for arterial and venous thrombus respectively. The result conformed with the T/B ratio of the removed thrombus and blood after 24 hours of injection of radiotracer. It indicates that the McAb SZ-51 has a great potential to bind with thrombus. In respect of thrombolysis, the Fab(fragment, antigen-binding) fragment of McAb SZ-51 was chemically conjugated of urokinase (UK) by the disulfide-linking reagent SPDP and 2-iminothiolane. The resulting conjugate was 3 to 5 times as potent as UK in vitro in human platelet-rich plasma assay. The increase of fibrinolytic potency was accompanied by a decrease of consumption of plasminogen and fibrinogen. It shows that the increase of potency is the result of selectivity increase

Roles of platelet STIM1 and Orai1 in glycoprotein VI- and thrombin-dependent procoagulant activity and thrombus formation.

Science.gov (United States)

Gilio, Karen; van Kruchten, Roger; Braun, Attila; Berna-Erro, Alejandro; Feijge, Marion A H; Stegner, David; van der Meijden, Paola E J; Kuijpers, Marijke J E; Varga-Szabo, David; Heemskerk, Johan W M; Nieswandt, Bernhard

2010-07-30

In platelets, STIM1 has been recognized as the key regulatory protein in store-operated Ca(2+) entry (SOCE) with Orai1 as principal Ca(2+) entry channel. Both proteins contribute to collagen-dependent arterial thrombosis in mice in vivo. It is unclear whether STIM2 is involved. A key platelet response relying on Ca(2+) entry is the surface exposure of phosphatidylserine (PS), which accomplishes platelet procoagulant activity. We studied this response in mouse platelets deficient in STIM1, STIM2, or Orai1. Upon high shear flow of blood over collagen, Stim1(-/-) and Orai1(-/-) platelets had greatly impaired glycoprotein (GP) VI-dependent Ca(2+) signals, and they were deficient in PS exposure and thrombus formation. In contrast, Stim2(-/-) platelets reacted normally. Upon blood flow in the presence of thrombin generation and coagulation, Ca(2+) signals of Stim1(-/-) and Orai1(-/-) platelets were partly reduced, whereas the PS exposure and formation of fibrin-rich thrombi were normalized. Washed Stim1(-/-) and Orai1(-/-) platelets were deficient in GPVI-induced PS exposure and prothrombinase activity, but not when thrombin was present as co-agonist. Markedly, SKF96365, a blocker of (receptor-operated) Ca(2+) entry, inhibited Ca(2+) and procoagulant responses even in Stim1(-/-) and Orai1(-/-) platelets. These data show for the first time that: (i) STIM1 and Orai1 jointly contribute to GPVI-induced SOCE, procoagulant activity, and thrombus formation; (ii) a compensating Ca(2+) entry pathway is effective in the additional presence of thrombin; (iii) platelets contain two mechanisms of Ca(2+) entry and PS exposure, only one relying on STIM1-Orai1 interaction.

Defective angiogenesis delays thrombus resolution: a potential pathogenetic mechanism underlying chronic thromboembolic pulmonary hypertension

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Panzenboeck, Adelheid; Winter, Max P; Schubert, Uwe; Voswinckel, Robert; Frey, Maria K; Jakowitsch, Johannes; Alimohammadi, Arman; Hobohm, Lukas; Mangold, Andreas; Bergmeister, Helga; Sibilia, Maria; Wagner, Erwin F; Mayer, Eckhard; Klepetko, Walter; Hoelzenbein, Thomas J; Preissner, Klaus T; Lang, Irene M

2015-01-01

Objective Restoration of patency is a natural target of vascular remodeling following venous thrombosis that involves vascular endothelial cells and smooth muscle cells as well as leukocytes. Acute pulmonary emboli usually resolve within six months. However, in some instances, thrombi transform into fibrous vascular obstructions, resulting in occlusion of the deep veins, or in chronic thromboembolic pulmonary hypertension (CTEPH). We proposed that dysregulated thrombus angiogenesis may contribute to thrombus persistence. Approach and Results Mice with an endothelial-cell-specific conditional deletion of vascular endothelial growth factor receptor 2/kinase insert domain protein receptor (VEGF-R2/Kdr) were utilized in a model of stagnant flow venous thrombosis closely resembling human deep vein thrombosis. Biochemical and functional analyses were performed on pulmonary endarterectomy specimens from patients with CTEPH, a human model of non-resolving venous thromboembolism. Endothelial cell-specific deletion of Kdr and subsequent ablation of thrombus vascularization delayed thrombus resolution. In accordance with these findings, organized human CTEPH thrombi were largely devoid of vascular structures. Several vessel-specific genes such as KDR, vascular endothelial cadherin and podoplanin were expressed at lower levels in white CTEPH thrombi than in organizing deep vein thrombi and organizing thrombi from aortic aneurysms. In addition, red CTEPH thrombi attenuated the angiogenic response induced by VEGF. Conclusions In the present work, we propose a mechanism of thrombus non-resolution demonstrating that endothelial cell-specific deletion of Kdr abates thrombus vessel formation, misguiding thrombus resolution. Medical conditions associated with the development of CTEPH may be compromising early thrombus angiogenesis. PMID:24526692

A Case of Myopathy, Encephalopathy, Lactic Acidosis and Stroke-Like Episodes (MELAS) Syndrome with Intracardiac Thrombus [corrected].

Science.gov (United States)

Joo, Jung-Chul; Seol, Myung Do; Yoon, Jin Won; Lee, Young Soo; Kim, Dong-Keun; Choi, Yong Hoon; Ahn, Hyo Seong; Cho, Wook Hyun

2013-03-01

Myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a multisystem clinical syndrome manifested by mitochondrial myopathy, encephalopathy, lactic acidosis and recurrent stroke-like episodes. A 27-year-old female with MELAS syndrome presented with cerebral infarction. Echocardiography revealed a thrombus attached to the apex of the hypertrophied left ventricle, with decreased systolic function. The embolism of the intracardiac thrombus might have been the cause of stroke. There should be more consideration given to the increased possibility of intracardiac thrombus formation when a MELAS patient with cardiac involvement is encountered.

Measurement of Thrombus Flux Using Transesophageal Echocardiography

Science.gov (United States)

Yamaguchi, Tadashi; Hirai, Kazuki; Aoki, Masami; Miyagi, Jin; Suzuki, Masahiko; Moriya, Hideshige; Hachiya, Hiroyuki

2006-05-01

Deep venous thrombosis (DVT) and pulmonary thromboembolism (PTE) are serious problem of total knee replacement (TKR). These diseases may be caused by a thrombus formed during the TKR operation. Therefore, understanding the flow volume of thrombus is important for curing and preventing PTE. In this paper, we tried to understanding the situation of the flow of thrombus by using transesophageal echocardiography movies. We applied the signal processing technique the FSET to extract the anomalous information from ultrasonic echo image. As a result of processing, the time change of the flow volume of thrombus was confirmed.

Roles of Platelet STIM1 and Orai1 in Glycoprotein VI- and Thrombin-dependent Procoagulant Activity and Thrombus Formation*

Science.gov (United States)

Gilio, Karen; van Kruchten, Roger; Braun, Attila; Berna-Erro, Alejandro; Feijge, Marion A. H.; Stegner, David; van der Meijden, Paola E. J.; Kuijpers, Marijke J. E.; Varga-Szabo, David; Heemskerk, Johan W. M.; Nieswandt, Bernhard

2010-01-01

In platelets, STIM1 has been recognized as the key regulatory protein in store-operated Ca2+ entry (SOCE) with Orai1 as principal Ca2+ entry channel. Both proteins contribute to collagen-dependent arterial thrombosis in mice in vivo. It is unclear whether STIM2 is involved. A key platelet response relying on Ca2+ entry is the surface exposure of phosphatidylserine (PS), which accomplishes platelet procoagulant activity. We studied this response in mouse platelets deficient in STIM1, STIM2, or Orai1. Upon high shear flow of blood over collagen, Stim1−/− and Orai1−/− platelets had greatly impaired glycoprotein (GP) VI-dependent Ca2+ signals, and they were deficient in PS exposure and thrombus formation. In contrast, Stim2−/− platelets reacted normally. Upon blood flow in the presence of thrombin generation and coagulation, Ca2+ signals of Stim1−/− and Orai1−/− platelets were partly reduced, whereas the PS exposure and formation of fibrin-rich thrombi were normalized. Washed Stim1−/− and Orai1−/− platelets were deficient in GPVI-induced PS exposure and prothrombinase activity, but not when thrombin was present as co-agonist. Markedly, SKF96365, a blocker of (receptor-operated) Ca2+ entry, inhibited Ca2+ and procoagulant responses even in Stim1−/− and Orai1−/− platelets. These data show for the first time that: (i) STIM1 and Orai1 jointly contribute to GPVI-induced SOCE, procoagulant activity, and thrombus formation; (ii) a compensating Ca2+ entry pathway is effective in the additional presence of thrombin; (iii) platelets contain two mechanisms of Ca2+ entry and PS exposure, only one relying on STIM1-Orai1 interaction. PMID:20519511

Role of newly formed platelets in thrombus formation in rat after clopidogrel treatment

DEFF Research Database (Denmark)

Kuijpers, Marijke J E; Megens, Remco T A; Nikookhesal, Elham

2011-01-01

Platelet P2Y₁₂ receptors play an important role in arterial thrombosis by stimulating thrombus growth. Both irreversibly (clopidogrel) and reversibly binding (ticagrelor, AZD6140) P2Y₁₂ antagonists are clinically used for restricted periods, but possible differences in platelet function recovery ...

Measurement of thrombus flux using transesophageal Echocardiography

International Nuclear Information System (INIS)

Yamaguchi, Tadashi; Hirai, Kazuki; Aoki, Masami; Miyagi, Jin; Suzuki, Masahiko; Moriya, Hideshige; Hachiya Hiroyuki

2006-01-01

Deep venous thrombosis (DVT) and pulmonary thromboembolism (PTE) are serious problem of total knee replacement (TKR). These diseases may be caused by a thrombus formed during the TKR operation. Therefore, understanding the flow volume of thrombus is important for curing and preventing PTE. In this paper, we tried to understanding the situation of the flow of thrombus by using transesophageal echocardiography movies. We applied the signal processing technique the fiber structure extraction technique (FSET) to extract the anomalous information from ultrasonic echo image. As a result of processing, the time change of the flow volume of thrombus was confirmed. (author)

Sixty-Four-Section Cardiac Computed Tomography in Mechanical Prosthetic Heart Valve Dysfunction: Thrombus or Pannus.

Science.gov (United States)

Gündüz, Sabahattin; Özkan, Mehmet; Kalçik, Macit; Gürsoy, Ozan Mustafa; Astarcioğlu, Mehmet Ali; Karakoyun, Süleyman; Aykan, Ahmet Çağri; Biteker, Murat; Gökdeniz, Tayyar; Kaya, Hasan; Yesin, Mahmut; Duran, Nilüfer Ekşi; Sevinç, Deniz; Güneysu, Tahsin

2015-12-01

Distinguishing pannus and thrombus in patients with prosthetic valve dysfunction is essential for the selection of proper treatment. We have investigated the utility of 64-slice multidetector computed tomography (MDCT) in distinguishing between pannus and thrombus, the latter amenable to thrombolysis. Sixty-two (23 men, mean age 44±14 years) patients with suspected mechanical prosthetic valve dysfunction assessed by transesophageal echocardiography were included in this prospective observational trial. Subsequently, MDCT was performed before any treatment was started. Periprosthetic masses were detected by MDCT in 46 patients, and their attenuation values were measured as Hounsfield Units (HU). Patients underwent thrombolysis unless contraindicated, and those with a contraindication or failed thrombolysis underwent surgery. A mass which was completely lysed or surgically detected as a clot was classified as thrombus, whereas a mass which was surgically detected as tissue overgrowth was classified as pannus. A definitive diagnosis could be achieved in 37 patients with 39 MDCT masses (22 thrombus and 17 pannus). The mean attenuation value of 22 thrombotic masses was significantly lower than that in 17 pannus (87±59 versus 322±122; Ppannus from thrombus. Complete lysis was more common for masses with HUpannus overgrowth, whereas a lower value is associated with thrombus formation. A higher attenuation (HU>90) is associated with reduced lysis rates. © 2015 American Heart Association, Inc.

Arterial 18F-fluorodeoxyglucose uptake reflects balloon catheter-induced thrombus formation and tissue factor expression via nuclear factor-κB in rabbit atherosclerotic lesions

International Nuclear Information System (INIS)

Yamashita, Atsushi; Zhao, Yan; Zhao, Songji

2013-01-01

Imaging modalities to assess atherosclerotic plaque thrombogenicity have not been established, so in this study the relationship between [ 18 F]-fluorodeoxyglucose ( 18 F-FDG) uptake and thrombus formation was investigated in rabbit atherosclerotic arteries. Atherosclerotic plaque was induced in the iliacofemoral artery by balloon injury and a 0.5% cholesterol diet. At 3 weeks after the first balloon injury, the arteries were visualized by 18 F-FDG positron emission tomography (PET) imaging 2 h after an 18 F-FDG infusion, and then arterial thrombus was induced by a second balloon injury of both iliacofemoral arteries. Imaging with 18 F-FDG-PET revealed significantly more radioactivity along the injured (0.63±0.12 standardized uptake value (SUV)max), than the contralateral non-injured artery (0.34±0.08 SUVmax, n=17, P 18 F-FDG uptake reflects the thrombogenicity of atherosclerotic plaque following balloon injury. (author)

Superior Venacava Thrombus-A Case Report

Directory of Open Access Journals (Sweden)

Bijay Sah

2016-03-01

Full Text Available Superior venacava (SVC thrombus is a condition requiring immediate diagnosis and treatment. SVC thrombus causes obstruction of blood flow through the SVC resulting in severe decrease in venous return from the head, neck and upper extremity to the heart. The presenting symptoms of SVC obstruction include headache, hoarseness of voice, dyspnea, and laryngeal edema, dizziness, swelling of face, neck, and upper extremity. We hereby present a case of SVC thrombus who presented to the casualty department of COMS-TH with features of SVC syndrome which was diagnosed and managed promptly.JCMS Nepal. 2016;12(1:33-5.

RhoG protein regulates platelet granule secretion and thrombus formation in mice.

Science.gov (United States)

Goggs, Robert; Harper, Matthew T; Pope, Robert J; Savage, Joshua S; Williams, Christopher M; Mundell, Stuart J; Heesom, Kate J; Bass, Mark; Mellor, Harry; Poole, Alastair W

2013-11-22

Rho GTPases such as Rac, RhoA, and Cdc42 are vital for normal platelet function, but the role of RhoG in platelets has not been studied. In other cells, RhoG orchestrates processes integral to platelet function, including actin cytoskeletal rearrangement and membrane trafficking. We therefore hypothesized that RhoG would play a critical role in platelets. Here, we show that RhoG is expressed in human and mouse platelets and is activated by both collagen-related peptide (CRP) and thrombin stimulation. We used RhoG(-/-) mice to study the function of RhoG in platelets. Integrin activation and aggregation were reduced in RhoG(-/-) platelets stimulated by CRP, but responses to thrombin were normal. The central defect in RhoG(-/-) platelets was reduced secretion from α-granules, dense granules, and lysosomes following CRP stimulation. The integrin activation and aggregation defects could be rescued by ADP co-stimulation, indicating that they are a consequence of diminished dense granule secretion. Defective dense granule secretion in RhoG(-/-) platelets limited recruitment of additional platelets to growing thrombi in flowing blood in vitro and translated into reduced thrombus formation in vivo. Interestingly, tail bleeding times were normal in RhoG(-/-) mice, suggesting that the functions of RhoG in platelets are particularly relevant to thrombotic disorders.

CORONARY EMBOLISM WITH FRAGMENTED THROMBUS FROM THE LEFT VENTRICLE IN PATIENT WITH POSTINFARCTION ANEURYSM

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Yu. F. Salakhova

2011-01-01

Full Text Available The thrombus formation in the left ventricle (LV cavity is a frequent complication of myocardial infarction (MI as well as a risk factor for peripheral arterial embolism. Probability of intraventricular thrombus depends on MI location and its therapy. A case of coronary embolism in a patient with anterior MI and thrombus in the LV aneurysm is considered in details. Successful percutaneous coronary intervention (PCI in the first 90 minutes after admission was performed. Decision to appoint a three-component antithrombotic therapy (acetylsalicylic acid, clopidogrel, warfarin was made on the 4th day of disease onset taking into account the combination of MI, stent placement in the anterior interventricular artery and the presence of left ventricular aneurysm with parietal thrombus. Recurrence of MI developed on the 9th day of disease onset. Aspiration thromboembolectomy was performed taking into account thrombosis of two coronary arteries. Warfarin therapy was discontinued in connection with subsequent clot lysis and development of not intensive nosebleed. Subsequent MI course was uneventful. In conclusion, even in spite of the timely achievement of PCI and early reperfusion, MI course can be complicated by thrombosis of the left ventricle and subsequent development of thromboembolic complications.

Iron-Deficiency Anemia Leading to Transient Ischemic Attacks due to Intraluminal Carotid Artery Thrombus

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H. Z. Batur Caglayan

2013-01-01

Full Text Available Reactive thrombocytosis secondary to iron-deficiency anemia (IDA is a rare but recognized cause of stroke. We report the case of a patient with iron-deficiency anemia presenting with multiple transient ischemic attacks (TIA due to intraluminal thrombus of an internal carotid artery. The putative mechanisms underlying anemia and stroke syndromes are not completely understood, and it is believed that iron deficiency may cause ischemic stroke by several potential mechanisms. Thrombocytosis is often associated with iron deficiency, and microcytosis produces a reduction in the red cell deformability and could produce a hypercoagulable state. The platelet count and function observed in iron-deficiency anemia could act synergistically to promote thrombus formation, especially in the setting of an underlying atherosclerotic disease. The presence of floating thrombus in a patient with clinical and MRI evidence of stroke represents a significant therapeutic dilemma and requires immediate decision about treatment.

Comparison of the effect of dabigatran and dalteparin on thrombus stability in a murine model of venous thromboembolism.

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Shaya, S A; Saldanha, L J; Vaezzadeh, N; Zhou, J; Ni, R; Gross, P L

2016-01-01

ESSENTIALS: Does thrombus stability alter the presentation of venous thromboembolism and do anticoagulants alter this? In a murine model, we imaged a femoral vein thrombus and quantified emboli in the pulmonary arteries. Dabigatran decreases thrombus stability via factor XIII increasing embolization and pulmonary emboli. This cautions against the unapproved use of dabigatran for acute initial treatment of deep vein thrombosis. Venous thromboembolism (VTE) is a collective term for deep vein thrombosis (DVT) and pulmonary embolism (PE). Thrombus instability possibly contributes to progression of DVT to PE, and direct thrombin inhibitors (DTIs) may alter this. To develop a model to assess thrombus stability and its link to PE burden, and identify whether DTIs, in contrast to low-molecular-weight heparin (LMWH), alter this correlation. Twelve minutes after ferric chloride-induced thrombus formation in the femoral vein of female mice, saline, dalteparin (LMWH) or dabigatran (DTI) was administered. Thrombus size and embolic events breaking off from the thrombus were quantified before treatment and at 10-min intervals after treatment for 2 h using intravital videomicroscopy. Lungs were stained for the presence of PE. Thrombus size was similar over time and between treatment groups. Total and large embolic events and pulmonary emboli were highest after treatment with dabigatran. Variations in amounts of pulmonary embolic events were not attributed to variations in thrombus size. Large embolic events correlated with the number of emboli per lung slice independent of treatment. Embolization in factor XIII deficient (FXIII(-/-) ) saline-treated mice was greater than that in wild-type (WT) saline-treated mice, but was similar to WT dabigatran-treated mice. We have developed a mouse model of VTE that can quantify emboli and correlate this with PE burden. Consistent with clinical data, dabigatran, a DTI, acutely decreases thrombus stability and increases PE burden compared with

Detection of extracellular genomic DNA scaffold in human thrombus

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Oklu, Rahmi; Albadawi, Hassan; Watkins, Michael T

2012-01-01

into thrombus remodeling. MATERIALS AND METHODS: Ten human thrombus samples were collected during cases of thrombectomy and open surgical repair of abdominal aortic aneurysms (five samples 1 y old). Additionally, an acute murine hindlimb ischemia model was created to evaluate...... thrombus samples in mice. Human sections were immunostained for the H2A/H2B/DNA complex, myeloperoxidase, fibrinogen, and von Willebrand factor. Mouse sections were immunostained with the H2A antibody. All samples were further evaluated after hematoxylin and eosin and Masson trichrome staining. RESULTS......: An extensive network of extracellular histone/DNA complex was demonstrated in the matrix of human ex vivo thrombus. This network is present throughout the highly cellular acute thrombus. However, in chronic thrombi, detection of the histone/DNA network was predominantly in regions of low collagen content...

Contemporary management of symptomatic primary aortic mural thrombus.

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Verma, Himanshu; Meda, Narendranadh; Vora, Simit; George, Robbie K; Tripathi, Ramesh K

2014-12-01

Primary aortic mural thrombus (PAMT) is an uncommon condition but an important source of noncardiogenic emboli with a difficult diagnosis and a high rate of complications, including high mortality. We report our experience of thromboembolic disease from PAMT and review its contemporary management. Retrospective analysis of prospectively collected data of all patients who presented with acute occlusion of a limb or visceral vessels between January 2011 and September 2013 was performed. A total of 88 patients presented with acute occlusion of the extremities or visceral arteries. All underwent extensive evaluation for the possible source of the embolism. Of these 88 patients, 19 patients (mean age, 41.2 years; male:female ratio, 1:2.1) were found to have aortic mural thrombus as the source of distal embolism. Thrombus was located in the thoracic aorta in 10 patients, in the perivisceral aorta in three patients, and in the infrarenal aorta in six patients. Thrombus in the thoracic aorta was treated with stent grafts in four patients, bare metal stents in three patients, and anticoagulation alone in two patients. In the suprarenal abdominal aorta, all three patients underwent trapdoor aortic thrombectomy. Infrarenal aortic thrombus was managed by aortobifemoral embolectomy in two patients, aortic stenting in two patients, surgical thrombectomy in one patient, and anticoagulation alone in one patient. Successful treatment, defined as freedom from further embolic events or recurrence of thrombus, was achieved in 14 of 19 patients (76.4%) with a mean follow-up period of 16.2 months (range, 2-28 months). There were four (21%) thrombus-related deaths, all due to primary thromboembolic insults. One patient needed a below-knee amputation because of a recurrent thrombotic episode. Symptomatic PAMT is an uncommon but important source of noncardiogenic embolus. It appears to occur more frequently in young women. Endovascular coverage of the aortic thrombus, when feasible

Prediction of thrombus-related mechanical prosthetic valve dysfunction using transesophageal echocardiography

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Lin, S. S.; Tiong, I. Y.; Asher, C. R.; Murphy, M. T.; Thomas, J. D.; Griffin, B. P.

2000-01-01

Identification of thrombus-related mechanical prosthetic valve dysfunction (MPVD) has important therapeutic implications. We sought to develop an algorithm, combining clinical and echocardiographic parameters, for prediction of thrombus-related MPVD in a series of 53 patients (24 men, age 52 +/- 16 years) who had intraoperative diagnosis of thrombus or pannus from 1992 to 1997. Clinical and echocardiographic parameters were analyzed to identify predictors of thrombus and pannus. Prevalence of thrombus and diagnostic yields relative to the number of predictors were determined. There were 22 patients with thrombus, 19 patients with pannus, and 12 patients with both. Forty-two of 53 masses were visualized using transesophageal echocardiography (TEE), including 29 of 34 thrombi or both thrombi and panni and 13 of 19 isolated panni. Predictors of thrombus or mixed presentation include mobile mass (p = 0.009), attachment to occluder (p = 0.02), elevated gradients (p = 0.04), and an international normalized ratio of or = 1 predictor. The prevalence of thrombus in the presence of or = 3 predictors is 14%, 69%, and 91%, respectively. Thus, TEE is sensitive in the identification of abnormal mass in the setting of MPVD. An algorithm based on clinical and transesophageal echocardiographic predictors may be useful to estimate the likelihood of thrombus in the setting of MPVD. In the presence of > or = 3 predictors, the probability of thrombus is high.

Large mobile thrombus in non-atherosclerotic thoracic aorta as the source of peripheral arterial embolism

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Brkovic Zoran

2005-11-01

Full Text Available Abstract The presence of thrombi in the atherosclerotic and/or aneurysmatic aorta with peripheral arterial embolism is a common scenario. Thrombus formation in a morphologically normal aorta, however, is a rare event. A 50 years old woman was admitted to the mergency department for pain, coldness, and anesthesia in the the left foot. She had a 25 years history of cigarette smoking, a history of postmenopausal hormone replacement therapy (HRT, hypercholesterolemia and hyperfibrinogenemia. An extensive serologic survey for hypercoagulability, including antiphospholipid antibodies, and vasculitis disorders was negative. Transesophageal echocardiography revealed a large, pedunculated and hypermobile thrombus attached to the aortic wall 5 cm distal of the left subclavian artery. The patient was admitted to the surgery department, where a 15 cm long fresh, parietal thrombus could be removed from the aorta showing no macroscopic wall lesions or any other morphologic abnormalities. This case report demonstrates the possibility of evolving a large, pedunculated thrombus in a morphologically intact aorta in a postmenopausal woman with thrombogenic conditions such as hyperfibrinogenemia, hypercholesterolemia, smoking and HRT. For these patients, profiling the individual risk and weighing the benefits against the potential risks is warranted before prescribing HRT.

Vibration acceleration promotes bone formation in rodent models.

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Ryohei Uchida

Full Text Available All living tissues and cells on Earth are subject to gravitational acceleration, but no reports have verified whether acceleration mode influences bone formation and healing. Therefore, this study was to compare the effects of two acceleration modes, vibration and constant (centrifugal accelerations, on bone formation and healing in the trunk using BMP 2-induced ectopic bone formation (EBF mouse model and a rib fracture healing (RFH rat model. Additionally, we tried to verify the difference in mechanism of effect on bone formation by accelerations between these two models. Three groups (low- and high-magnitude vibration and control-VA groups were evaluated in the vibration acceleration study, and two groups (centrifuge acceleration and control-CA groups were used in the constant acceleration study. In each model, the intervention was applied for ten minutes per day from three days after surgery for eleven days (EBF model or nine days (RFH model. All animals were sacrificed the day after the intervention ended. In the EBF model, ectopic bone was evaluated by macroscopic and histological observations, wet weight, radiography and microfocus computed tomography (micro-CT. In the RFH model, whole fracture-repaired ribs were excised with removal of soft tissue, and evaluated radiologically and histologically. Ectopic bones in the low-magnitude group (EBF model had significantly greater wet weight and were significantly larger (macroscopically and radiographically than those in the other two groups, whereas the size and wet weight of ectopic bones in the centrifuge acceleration group showed no significant difference compared those in control-CA group. All ectopic bones showed calcified trabeculae and maturated bone marrow. Micro-CT showed that bone volume (BV in the low-magnitude group of EBF model was significantly higher than those in the other two groups (3.1±1.2mm3 v.s. 1.8±1.2mm3 in high-magnitude group and 1.3±0.9mm3 in control-VA group, but

Mice with deleted multimerin 1 and alpha-synuclein genes have impaired platelet adhesion and impaired thrombus formation that is corrected by multimerin 1.

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Reheman, Adili; Tasneem, Subia; Ni, Heyu; Hayward, Catherine P M

2010-05-01

Multimerin 1 is a stored platelet and endothelial cell adhesive protein that shows significant conservation. In vitro, multimerin 1 supports platelet adhesion and it also binds to collagen and enhances von Willebrand factor-dependent platelet adhesion to collagen. As selective, multimerin 1 deficient mice have not been generated, we investigated multimerin 1 effects on platelet adhesion using a subpopulation of C57BL/6J mice with tandem deletion of the genes for multimerin 1 and alpha-synuclein, a protein that inhibits alpha-granule release in vitro. We postulated that multimerin 1/alpha-synuclein deficient mice might show impaired platelet adhesive function from multimerin 1 deficiency and increased alpha-granule release from alpha-synuclein deficiency. Platelet function was assessed by intravital microscopy, after ferric chloride injury, using untreated and human multimerin 1-transfused multimerin 1/alpha-synuclein deficient mice, and by in vitro assays of adhesion, aggregation and thrombin-induced P-selectin release. Multimerin 1/alpha-synuclein deficient mice showed impaired platelet adhesion and their defective thrombus formation at sites of vessel injury improved with multimerin 1 transfusion. Although multimerin 1/alpha-synuclein deficient platelets showed increased P-selectin release at low thrombin concentrations, they also showed impaired adhesion to collagen, and attenuated aggregation with thrombin, that improved with added multimerin 1. Our data suggest that multimerin 1 supports platelet adhesive functions and thrombus formation, which will be important to verify by generating and testing selective multimerin 1 deficient mice. Copyright (c) 2010. Published by Elsevier Ltd.

Incidence of thromboembolism following detection by trans-oesophageal echocardiography of left atrial thrombus

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Ciara Mahon

2015-09-01

Conclusion: This is the only study to date that has looked at the incidence of ischemic stroke following a confirmed LAA thrombus, LA thrombus or pre-thrombus state. This single centre study found low stroke rates over a six month follow-up period in patients with a confirmed LAA thrombus, LA thrombus or pre-thrombus state and optimization of OAC. Larger studies would be required to confirm these findings.

Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging

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Motte, Louise de la, E-mail: louise.de.la.motte@rh.regionh.dk [Department of Vascular Surgery, Rigshospitalet and University of Copenhagen (Denmark); Pedersen, Mads Møller, E-mail: phd@medit.dk [Department of Radiology, Rigshospitalet and University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark); Thomsen, Carsten, E-mail: carsten.thomsen@rh.regionh.dk [Department of Radiology, Rigshospitalet and University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark); Vogt, Katja, E-mail: Vogt@dadlnet.dk [Department of Vascular Surgery, Rigshospitalet and University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark); Schroeder, Torben V., E-mail: Torben.Veith.schroeder@rh.regionh.dk [Department of Vascular Surgery, Rigshospitalet and University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark); Lonn, Lars, E-mail: lonn.lars@gmail.com [Department of Vascular Surgery and Department of Radiology, Rigshospitalet and University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)

2013-10-01

Background: Magnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics of intraluminal thrombus specimens to the appearance on magnetic resonance imaging. Methods: Thirty-four patients undergoing open surgery for abdominal aortic aneurysm had a preoperative MRI obtained with a 1.5 T magnet. Qualitative categorization was performed (blinded and in consensus) and correlated to intraluminal thrombus to muscle signal-intensity ratios. Morphology of intraluminal thrombus specimens collected during surgery were compared to the magnetic resonance imaging categories and specimen weight was correlated to thrombus volume measured on preoperative computer tomography angiography. Results: Blinded MRI categorization resulted in agreement in 22 out of 34 intraluminal thrombi (Kappa value 0.3, p = 0.006). Medians (p = 0.004) and distribution (p = 0.002) of signal-intensity ratios varied significantly across the three MRI categories obtained by consensus. Heterogeneous and homogenous specimen appearance corresponded to similar appearances on MRI in 78% and 55% respectively, resulting in an overall Kappa = 0.4 (p = 0.04). Intraluminal thrombus volume and weight correlated well (r{sub s} 0.831, p < 0.001) with a mean difference of 60 g (95% CI 38–80 g), without proportional bias. Conclusion: Qualitative evaluation of intraluminal thrombus morphology based on MRI can be quantified by measuring signal-intensity ratios. Concurrently a fair agreement to blinded qualitative evaluation of thrombus specimens can be obtained. However, the evaluation is impaired by loss of a large proportion of thrombus during sampling.

Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging

International Nuclear Information System (INIS)

Motte, Louise de la; Pedersen, Mads Møller; Thomsen, Carsten; Vogt, Katja; Schroeder, Torben V.; Lonn, Lars

2013-01-01

Background: Magnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics of intraluminal thrombus specimens to the appearance on magnetic resonance imaging. Methods: Thirty-four patients undergoing open surgery for abdominal aortic aneurysm had a preoperative MRI obtained with a 1.5 T magnet. Qualitative categorization was performed (blinded and in consensus) and correlated to intraluminal thrombus to muscle signal-intensity ratios. Morphology of intraluminal thrombus specimens collected during surgery were compared to the magnetic resonance imaging categories and specimen weight was correlated to thrombus volume measured on preoperative computer tomography angiography. Results: Blinded MRI categorization resulted in agreement in 22 out of 34 intraluminal thrombi (Kappa value 0.3, p = 0.006). Medians (p = 0.004) and distribution (p = 0.002) of signal-intensity ratios varied significantly across the three MRI categories obtained by consensus. Heterogeneous and homogenous specimen appearance corresponded to similar appearances on MRI in 78% and 55% respectively, resulting in an overall Kappa = 0.4 (p = 0.04). Intraluminal thrombus volume and weight correlated well (r s 0.831, p < 0.001) with a mean difference of 60 g (95% CI 38–80 g), without proportional bias. Conclusion: Qualitative evaluation of intraluminal thrombus morphology based on MRI can be quantified by measuring signal-intensity ratios. Concurrently a fair agreement to blinded qualitative evaluation of thrombus specimens can be obtained. However, the evaluation is impaired by loss of a large proportion of thrombus during sampling

Development of a real-time and quantitative thrombus sensor for an extracorporeal centrifugal blood pump by near-infrared light.

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Sakota, Daisuke; Fujiwara, Tatsuki; Ohuchi, Katsuhiro; Kuwana, Katsuyuki; Yamazaki, Hiroyuki; Kosaka, Ryo; Nishida, Masahiro; Mizuno, Tomohiro; Arai, Hirokuni; Maruyama, Osamu

2018-01-01

We developed an optical thrombus sensor for a monopivot extracorporeal centrifugal blood pump. In this study, we investigated its quantitative performance for thrombus detection in acute animal experiments of left ventricular assist using the pump on pathogen-free pigs. Optical fibers were set in the driver unit of the pump. The incident light at the near-infrared wavelength of 810 nm was aimed at the pivot bearing, and the resulting scattered light was guided to the optical fibers. The detected signal was analyzed to obtain the thrombus formation level. As a result, real-time and quantitative monitoring of the thrombus surface area on the pivot bearing was achieved with an accuracy of 3.6 ± 2.3 mm 2 . In addition, the sensing method using the near-infrared light was not influenced by changes in the oxygen saturation and the hematocrit. It is expected that the developed sensor will be useful for optimal anticoagulation management for long-term extracorporeal circulation therapies.

Split-bolus single-phase cardiac multidetector computed tomography for reliable detection of left atrial thrombus. Comparison to transesophageal echocardiography

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Staab, W.; Zwaka, P.A.; Sohns, J.M.; Schwarz, A.; Lotz, J. [University Medical Center Goettingen Univ. (Germany). Inst. for Diagnostic and Interventional Radiology; Sohns, C.; Vollmann, D.; Zabel, M.; Hasenfuss, G. [Goettingen Univ. (Germany). Dept. of Cardiology and Pneumology; Schneider, S. [Goettingen Univ. (Germany). Dept. of Medical Statistics

2014-11-15

Evaluation of a new cardiac MDCT protocol using a split-bolus contrast injection protocol and single MDCT scan for reliable diagnosis of LA/LAA thrombi in comparison to TEE, optimizing radiation exposure and use of contrast agent. A total of 182 consecutive patients with drug refractory AF scheduled for PVI (62.6% male, mean age: 64.1 ± 10.2 years) underwent routine diagnostic work including TEE and cardiac MDCT for the evaluation of LA/LAA anatomy and thrombus formation between November 2010 and March 2012. Contrast media injection was split into a pre-bolus of 30 ml and main bolus of 70 ml iodinated contrast agent separated by a short time delay. In this study, split-bolus cardiac MDCT identified 14 of 182 patients with filling defects of the LA/LAA. In all of these 14 patients, abnormalities were found in TEE. All 5 of the 14 patients with thrombus formation in cardiac MDCT were confirmed by TEE. MDCT was 100% accurate for thrombus, with strong but not perfect overall results for SEC equivalent on MDCT.

Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

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Xu Zhiliang

2010-01-01

Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

An unexpected complication of acute pancreatitis: Intra-cardiac thrombus.

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Keskin, Muhammed; Gümüşdağ, Ayça; Börklü, Edibe Betül; Dayı, Şennur Ünal; Avcı, İlhan İlker; Güvenç, Tolga Sinan; Güngör, Barış; Karabay, Can Yücel; Kozan, Ömer

2017-05-01

Left atrial thrombus after acute pancreatitis (AP) is a rare clinical statement. Because of induction of systemic prothrombotic process by AP; some patients with underlying risk factors may develop an intra-cardiac thrombus. We present a 53years-old-woman with moderate mitral stenosis and atrial fibrillation. However the patient was under warfarin treatment, she developed a big left atrial big thrombus which was originated from left atrial appendage after she was suffered from AP. Copyright © 2016 Elsevier Inc. All rights reserved.

Study of 99Tcm-annexin V distribution in inferior vena cava thrombus models of rabbits

International Nuclear Information System (INIS)

Wu Dayong; Zhang Wenyan; Bian Yanzhu; Hu Yujing

2013-01-01

To study 99 Tc m -Annexin V distribution in inferior vena cava thrombus models of rabbits and uptake of 99 Tc m -Annexin V in fresh and old venous thrombus. Rabbits (n=15) were randomly grouped into 3 groups (the fresh thrombus group, old thrombus group, and control group). The rabbits of two thrombus groups developed inferior vena cava thrombus models by operations. The control group received sham operation. The fresh thrombus group and control group rabbits were injected 99 Tc m -Annexin V after operating 1 d; the old thrombus group 14 d. After 1 h all rabbits were killed by injecting overdose pentobarbital sodium. The thrombus (or the inferior vena cava about 3 cm below inferior pole of right kidney level in the control group rabbits), blood, thrombus area inferior vena cava, head lateral inferior vena cava (except the control group), thigh muscle, stomach, myocardium, pulmonary, liver, kidney, spleen, bone and small intestine were obtained from all group rabbits. The ex tissue and blood were weighed and measured by a Well-type detector. The percentage of the injected dose per gram of ex tissue (or blood) was calculated by the above data. The thrombus to blood, thrombus area inferior vena cava, head lateral inferior vena cava and thigh muscle ratios were calculated by percentage of the injected dose per gram of ex tissue (or blood). The test was used to compare the fresh thrombus group and old thrombus group by SPSS 17.0. The percentage of' the injected dose per gram of thrombi (0.01894± 0.002 16% ID/g) in the fresh thrombus group was higher than the old thrombus group (0.00473±0.001 28% ID/g), P<0.05. The thrombus to blood, thrombus area inferior vena cava, head lateral inferior vena cava and muscle ratios (3.42±1.06, 26.32±13.60, 31.23 ±16.00, 111.62±52.23) in the fresh thrombus group were higher than the old thrombus group (0.98±0.09, 5.12±2.01, 6.25±2.38, 21.82±5.93), P<0.05 for all. All the thrombi of the fresh thrombus group were confirmed

Characterization of an experimental venous thrombus model with MRI, phlebography and histology

International Nuclear Information System (INIS)

Schmitz, S.A.; Schiffler, S.; Gust, R.; Winterhalter, S.; Wolf, K.J.; Coupland, S.E.

2005-01-01

Introduction: Several magnetic resonance (MR) techniques designed to demonstrate the characteristic signal intensity of blood degeneration products of thrombi have been suggested, but the effect of thrombus organization on the MR display, in particular with regard to its temporal evolution, remains to be determined. It is the purpose of this study to develop a stagnation thrombus model in rabbits and to characterize thrombus at different ages with two (MR) imaging techniques, phlebography and histology. Materials and Methods: Venous stagnation thrombi were induced in the external jugular veins of rabbits using a minimally invasive radiological technique to produce artificial embolic vascular occlusion and hypercoagulability. Twenty-five animals were divided into 5 groups of 5 animals, and each group underwent 1.5 T MR imaging at 1, 3, 5, 7 and 9 days after thrombus induction using a T1-weighted magnetization-prepared rapid gradient-echo sequence (MP-RAGE: TR 10.4 msec, TE 4.0 msec, FA 15 ) and a T2-weighted fast low-angle shot sequence (FLASH: TR 54 msec, TE 18 msec, FA15 ). The thrombus length was measured on the T1-weighted images. Thrombus conspicuity, signal intensity, and heterogeneity on T2* weighted images were described using visual scales. Radiographic venography and histology served as reference methods. Results: Thrombi were successfully induced in all animals. The overall thrombus length decreased from 43±9 (day 1 after induction) to 23±4 mm (day 9). On 3D-reconstructions of the T1-weighted images, the visible portion of the true thrombus length relative to the overall thrombus length was 0.16±0.3 (day 1), 0.24±0.3 (day 3),0.38±0.5 (day 5), 0.06±0.1 (day 7) and 0.00 (day 9). Sixteen of 25 thrombi were detectable with the T2*-weighted technique. The overall thrombus signal intensity decreased with the age of the thrombus from day 1 to day 9. The histological evaluation showed that the rabbit thrombi closely resemble human thrombi morphologically

Evaluation of the thrombus of abdominal aortic aneurysms using contrast enhanced ultrasound - preliminary results

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Łukasiewicz, Adam; Garkowski, Adam; Rutka, Katarzyna; Janica, Jacek; Łebkowska, Urszula

2016-09-01

It is hypothesized that the degree of vascularization of the thrombus may have a significant impact on the rupture of aortic aneurysms. The presence of neovascularization of the vessel wall and mural thrombus has been confirmed only in histopathological studies. However, no non-invasive imaging technique of qualitative assessment of thrombus and neovascularization has been implemented so far. Contrast-enhanced ultrasound (CEUS) has been proposed as a feasible and minimally invasive technique for in vivo visualization of neovascularization in the evaluation of tumors and atherosclerotic plaques. The aim of this study was the evaluation of mural thrombus and AAAs wall with CEUS. CEUS was performed in a group of seventeen patients with AAAs. The mural thrombus enhancement was recognized in 12 cases, yet no significant correlation between the degree of contrast enhancement and AAAs diameter, thrombus width, and thrombus echogenicity was found. We observed a rise in AAAs thrombus heterogeneity with the increase in the aneurysm diameter (r = 0.62, p = 0.017). In conclusion CEUS can visualize small channels within AAAs thrombus, which could be a result of an ongoing angiogenesis. There is a need for further research to find out whether the degree of vascularization of the thrombus may have a significant impact on the rupture of aneurysms.

Left atrial thrombus following bilobectomy: a case report

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Kaya Ugur

2010-02-01

Full Text Available Abstract Introduction Left atrial free floating ball thrombus is a relatively rare event, especially without mitral valve disease. Case presentation A 61-year-old Turkish man was admitted to our hospital with a thrombus mass in his left atrium. Five months earlier, he had undergone right bilobectomy and superior bronchoplasty due to squamous cell carcinoma in the lung. The patient had no evidence of cardiac disease except atrial fibrillation and there were no defined embolizations. The thrombus mass was surgically removed. The patient was discharged from hospital on the sixth postoperative day. Conclusion Surgery with cardiopulmonary bypass is a safe method for treatment. The patient should be medicated with warfarin, especially in the presence of atrial fibrillation.

A Left Main Coronary Artery Thrombus Presenting as a Non St Elevation MI.

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Ezema, U; Daberkow, D; Delord, T; Guidry, L; Sells, N R

2017-01-01

Left main coronary artery (LMCA); thrombus with an acute myocardial infarction identified with coronary angiography is a clinically rare condition with an extremely high mortality rate. We present a case of LMCA thrombus that presented as a non-ST elevation myocardial infarction (NSTEMI);. A 45-year-old woman with a history of tobacco use and hyperlipidemia presented with a complaint of 10/10 "hard pain" across her chest radiating to her left shoulder and breast which woke her from sleep. The pain was constant and severe, with no alleviation with rest. She had not experienced anything like this before. Workup revealed an upward trending troponin (1.98.989.79);, and an EKG with some tachycardia but no ST elevation or T wave changes. Her CBC, CMP and coagulation studies were unremarkable. A toxicology screen was positive for opiates and benzodiazepines, medications she was on for pain and anxiety respectively. ACS protocol was started with DAPT, LMWH, Statin, ACEi, and Beta-blocker. An angiogram revealed a large thrombus in the LM coronary artery extending into the aorta with concomitant 99 percent stenosis of distal LAD. 2D Echo w/ bubble contrast was significant for PFO, akinetic apical inferior and anterior wall. The mid antero-septum and apical lateral wall were hypokinetic. Interventional Cardiology and CTS recommended conservative management with medical optimization (Continue DAPT, heparin);, watchful waiting for the thrombus to resorb. Left main coronary artery thrombosis (LMCAT); identified during coronary angiography is a rare and challenging condition. It is a life threatening condition with an approximate incidence rate of 0.8 percent . It is thought to be secondary to plaque rupture with subsequent thrombus formation that is associated with persistent hypercoagulable state, cocaine induced plaque rupture or coronary vasospasm, post-partum state and embolization of intra-cardiac masses. The patient presentation can vary from sudden cardiac death to

Matrix Metalloproteinase 9 (MMP-9 Regulates Vein Wall Biomechanics in Murine Thrombus Resolution.

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Khanh P Nguyen

Full Text Available Deep venous thrombosis is a common vascular problem with long-term complications including post-thrombotic syndrome. Post-thrombotic syndrome consists of leg pain, swelling and ulceration that is related to incomplete or maladaptive resolution of the venous thrombus as well as loss of compliance of the vein wall. We examine the role of metalloproteinase-9 (MMP-9, a gene important in extracellular remodeling in other vascular diseases, in mediating thrombus resolution and biomechanical changes of the vein wall.The effects of targeted deletion of MMP-9 were studied in an in vivo murine model of thrombus resolution using the FVB strain of mice. MMP-9 expression and activity significantly increased on day 3 after DVT. The lack of MMP-9 impaired thrombus resolution by 27% and this phenotype was rescued by the transplantation of wildtype bone marrow cells. Using novel biomechanical techniques, we demonstrated that the lack of MMP-9 significantly decreased thrombus-induced loss of vein wall compliance. Biomechanical analysis of the contribution of individual structural components showed that MMP-9 affected the elasticity of the extracellular matrix and collagen-elastin fibers. Biochemical and histological analyses correlated with these biomechanical effects as thrombi of mice lacking MMP-9 had significantly fewer macrophages and collagen as compared to those of wildtype mice.MMP-9 mediates thrombus-induced loss of vein wall compliance by increasing stiffness of the extracellular matrix and collagen-elastin fibers during thrombus resolution. MMP-9 also mediates macrophage and collagen content of the resolving thrombus and bone-marrow derived MMP-9 plays a role in resolution of thrombus mass. These disparate effects of MMP-9 on various aspects of thrombus illustrate the complexity of individual protease function on biomechanical and morphometric aspects of thrombus resolution.

Matrix Metalloproteinase 9 (MMP-9) Regulates Vein Wall Biomechanics in Murine Thrombus Resolution

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Nguyen, Khanh P.; McGilvray, Kirk C.; Puttlitz, Christian M.; Mukhopadhyay, Subhradip; Chabasse, Christine; Sarkar, Rajabrata

2015-01-01

Objective Deep venous thrombosis is a common vascular problem with long-term complications including post-thrombotic syndrome. Post-thrombotic syndrome consists of leg pain, swelling and ulceration that is related to incomplete or maladaptive resolution of the venous thrombus as well as loss of compliance of the vein wall. We examine the role of metalloproteinase-9 (MMP-9), a gene important in extracellular remodeling in other vascular diseases, in mediating thrombus resolution and biomechanical changes of the vein wall. Methods and Results The effects of targeted deletion of MMP-9 were studied in an in vivo murine model of thrombus resolution using the FVB strain of mice. MMP-9 expression and activity significantly increased on day 3 after DVT. The lack of MMP-9 impaired thrombus resolution by 27% and this phenotype was rescued by the transplantation of wildtype bone marrow cells. Using novel biomechanical techniques, we demonstrated that the lack of MMP-9 significantly decreased thrombus-induced loss of vein wall compliance. Biomechanical analysis of the contribution of individual structural components showed that MMP-9 affected the elasticity of the extracellular matrix and collagen-elastin fibers. Biochemical and histological analyses correlated with these biomechanical effects as thrombi of mice lacking MMP-9 had significantly fewer macrophages and collagen as compared to those of wildtype mice. Conclusions MMP-9 mediates thrombus-induced loss of vein wall compliance by increasing stiffness of the extracellular matrix and collagen-elastin fibers during thrombus resolution. MMP-9 also mediates macrophage and collagen content of the resolving thrombus and bone-marrow derived MMP-9 plays a role in resolution of thrombus mass. These disparate effects of MMP-9 on various aspects of thrombus illustrate the complexity of individual protease function on biomechanical and morphometric aspects of thrombus resolution. PMID:26406902

Metastatic Adenocarcinoma Presenting as Extensive Cavoatrial Tumor Thrombus

International Nuclear Information System (INIS)

Johari, Bushra; Abdul Aziz, Yang Faridah; Krishnasamy, Sivakumar; Looi, Lai Meng; Hashim, Shahrul Amry; Raja Mokhtar, Raja Amin

2015-01-01

The presence of tumor thrombus in the right atrium is frequently the result of direct intraluminal extension of infra-diaphragmatic malignancy into the inferior vena cava (IVC) or supradiaphragmatic carcinoma into the superior vena cava (SVC). Right atrial tumor thrombus with extension into both SVC and IVC has not been reported in the literature. We present a patient who presented with symptoms of right atrial and SVC obstruction. Imaging revealed presence of a thrombus in the right atrium, extending to the SVC and IVC, with the additional findings of a left adrenal mass and multiple liver lesions. The histopathological examination of the right atrial mass revealed metastatic adenocarcinoma cells. The patient was given a presumptive diagnosis of metastatic adenocarcinoma, most likely adrenal in origin, with multiple hepatic lesions suspicious for metastasis. The clinical outcome of the patient was not favorable; the patient succumbed before the adrenal mass could be confirmed to be the primary tumor. This case highlights that in patients manifesting with extensive cavoatrial thrombus as, the existence of primary carcinoma should be considered especially in the adrenal cortex or in the lung

Formation and acceleration of precompressed compact tori in RACE

International Nuclear Information System (INIS)

Molvik, A.W.; Eddleman, J.L.; Hammer, J.H.; Hartman, C.W.; McLean, H.S.

1990-01-01

Many applications of the compact torus accelerator, CTA, concept (such as a driver for inertial fusion, or magnetically insulated inertial fusion) require maximizing the power density by compressing the compact torus, CT. The ring accelerator experiment, RACE, has compressed CT's by a factor of 2 in radius before acceleration, after being reconfigured with a precompressor cone followed by a short, 80 cm long, coaxial accelerator. The authors show the gas valves and gun, precompressor, and the beginning of the accelerator. The inner acceleration electrode begins at the precompressor cone after passing through the inner gun electrode. The authors discuss the experimental results of slow formation, compression, and acceleration in this new geometry

Associations Between Collateral Status and Thrombus Characteristics and Their Impact in Anterior Circulation Stroke.

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Alves, Heitor C; Treurniet, Kilian M; Dutra, Bruna G; Jansen, Ivo G H; Boers, Anna M M; Santos, Emilie M M; Berkhemer, Olvert A; Dippel, Diederik W J; van der Lugt, Aad; van Zwam, Wim H; van Oostenbrugge, Robert J; Lingsma, Hester F; Roos, Yvo B W E M; Yoo, Albert J; Marquering, Henk A; Majoie, Charles B L M

2018-02-01

Thrombus characteristics and collateral score are associated with functional outcome in patients with acute ischemic stroke. It has been suggested that they affect each other. The aim of this study is to evaluate the association between clot burden score, thrombus perviousness, and collateral score and to determine whether collateral score influences the association of thrombus characteristics with functional outcome. Patients with baseline thin-slice noncontrast computed tomography and computed tomographic angiography images from the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands) were included (n=195). Collateral score and clot burden scores were determined on baseline computed tomographic angiography. Thrombus attenuation increase was determined by comparing thrombus density on noncontrast computed tomography and computed tomographic angiography using a semiautomated method. The association of collateral score with clot burden score and thrombus attenuation increase was evaluated with linear regression. Mediation and effect modification analyses were used to assess the influence of collateral score on the association of clot burden score and thrombus attenuation increase with functional outcome. A higher clot burden score (B=0.063; 95% confidence interval, 0.008-0.118) and a higher thrombus attenuation increase (B=0.014; 95% confidence interval, 0.003-0.026) were associated with higher collateral score. Collateral score mediated the association of clot burden score with functional outcome. The association between thrombus attenuation increase and functional outcome was modified by the collateral score, and this association was stronger in patients with moderate and good collaterals. Patients with lower thrombus burden and higher thrombus perviousness scores had higher collateral score. The positive effect of thrombus perviousness on clinical outcome was only present in patients with

Intracardiac thrombus in Behçet's disease: Two case reports

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Brahem Radhia

2005-07-01

Full Text Available Abstract Intracardiac thrombus in Behçet's disease is an extremely rare manifestation. We report two such cases. A 20-year-old man presented with dyspnoea, cough and haemoptysis. Right heart thrombus associated with pulmonary artery aneurysm and thromboembolism was identified by helical CT and transoesophageal echocardiography. The second case was a 29-year-old male admitted for fever and chest pain. A diagnosis of right atrial thrombosis associated with pulmonary embolism and hyperhomocysteinemia was made. Due to the absence of haemodynamic compromise, medical management consisting of immunosupressive and anticoagulation therapy was adopted which resulted in complete dissolution of the thrombus with dramatic clinical improvement in both cases of clinical status. Conclusion intracardiac thrombus is a rare complication of Behçet's disease. As shown in our patients, medical treatment should be considered as the first line.

ST Elevation Infarction after Heart Transplantation Induced by Coronary Spasms and Mural Thrombus Detected by Optical Coherence Tomography

DEFF Research Database (Denmark)

Clemmensen, Tor Skibsted; Holm, Niels Ramsing; Eiskjær, Hans

2016-01-01

The case illustrates the possible link between coronary spasms, intraluminal thrombus formation, and widespread organized and layered thrombi in HTx patients. Furthermore, the case underlines the clinical value of OCT as a novel method for high-resolution vessel imaging in heart-transplanted (HTx...

Retrievable Vena Cava Filters in Major Trauma Patients: Prevalence of Thrombus Within the Filter

International Nuclear Information System (INIS)

Mahrer, Arie; Zippel, Douglas; Garniek, Alexander; Golan, Gil; Bensaid, Paul; Simon, Daniel; Rimon, Uri

2008-01-01

The purpose of this study was to report the prevalence of thrombus within a retrievable vena cava filter inserted prophylactically in major trauma patients referred for filter extraction. Between November 2002 and August 2005, 80 retrievable inferior vena cava filters (68 Optease and 12 Gunther-Tulip) were inserted into critically injured trauma patients (mean injury severity score 33.5). The filters were inserted within 1 to 6 (mean 2) days of injury. Thirty-seven patients were referred for filter removal (32 with Optease and 5 with Gunther-Tulip). The indwelling time was 7 to 22 (mean 13) days. All patients underwent inferior vena cavography prior to filter removal. There were no insertion-related complications and all filters were successfully deployed. Forty-three (54%) of the 80 patients were not referred for filter removal, as these patients continued to have contraindications to anticoagulation. Thirty-seven patients (46%) were referred for filter removal. In eight of them (22%) a large thrombus was seen within the filters and they were left in place, all with the Optease device. The other 29 filters (36%) were removed uneventfully.We conclude that the relatively high prevalence of intrafilter thrombi with the Optease filter may be explained by either spontaneous thrombus formation or captured emboli.

HEMOSTATIC SYSTEM CONDITION AND HEART REMODELING IN PATIENTS WITH Q-WAVE MYOCARDIAL INFARCTION WITH ACUTE ANEURYSMS AND LEFT VENTRICLE THROMBUS

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V. D. Syvolap

2014-02-01

Full Text Available Introduction. Worldwide myocardial infarction (MI is one of the main causes of morbidity and mortality. Thanks to advances in modern cardiology we achieved a significant reduction in mortality and the incidence of fatal complications of acute Q-wave MI. However, keeping in mind the pathogenetic features of myocardial defeat of the left ventricle (LV cavity dilation and thinning at the focus of myocardial infarction, which increase the risk of left ventricular aneurysm development and parietal thrombus formation, it is impossible to reduce significantly the risk of these serious complications development. Post-infarction left ventricular aneurysm, extremely unfavorable prognostic factor complicates the course of Q-wave myocardial infarction in 30% of cases. The likelihood of parietal clot development in the anterior apical localization of aneurysms is 32%. The reasons of parietal clot formation are varied and are not fully disclosed, that is responsible for the relevance of this study. Aim: to investigate the serum level of protein C, von Willebrand factor, the expression of vascular adhesion molecules sVCAM-1, platelet aggregation properties and to evaluate their relationship with the structural and functional performance of the heart in patients with acute Q-wave myocardial infarction with aneurysm and parietal thrombus of LV. Methods. 110 patients (67 men and 43 women, mean age - 63,2 ± 5,7 years, with a diagnosis of acute Q-wave myocardial infarction were involved into the study. The first group included 72 patients with postinfarction left ventricular aneurysm, the second - 38 patients with postinfarction aneurysm and parietal thrombus of LV. Serum levels of protein C, von Willebrand factor, the expression of vascular adhesion molecules sVCAM-1, platelet aggregation properties were studied and their relationship with the structural and functional performance of the heart were evaluated. Results. There were revealed high activity of the key

Traversing boundaries: thrombus in transit with paradoxical embolism

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Varun Miriyala

2016-09-01

Full Text Available A 72-year-old male is diagnosed with paradoxical embolus after he presented with concurrent deep vein thrombosis, stroke, and multiple arterial emboli in the presence of a patent foramen ovale (PFO. Paradoxical embolus requires the passage of a thrombus from the venous into the arterial circulation through a right-to-left shunt leading to systemic embolism. But, despite the high incidence of PFO (27.3% across all age groups by autopsy, paradoxical embolism (PDE is uncommon, representing <2% of all arterial emboli. We present a case report where a thrombus has been directly observed passing through the PFO during an echocardiogram study; thus, clearly delineating the true cause of multiple thromboemboli and stoke in our patient. Subsequent Transesophageal Echocardiography (TEE also interestingly showed the thrombus in transit in the aorta and pulmonary artery.

Transient Ischemic Attack and Ischemic Stroke in Danon Disease with Formation of Left Ventricular Apical Thrombus despite Normal Systolic Function

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Takeshi Tsuda

2017-01-01

Full Text Available Danon disease is a rare X-linked dominant skeletal and cardiac muscle disorder presenting with hypertrophic cardiomyopathy, Wolf-Parkinson-White syndrome, skeletal myopathy, and mild intellectual disability. Early morbidity and mortality due to heart failure or sudden death are known in Danon disease, more in males than in females. Here, we present a 17-year-old female adolescent with Danon disease and severe concentric hypertrophy with normal left ventricular (LV systolic function, who has been complaining of intermittent headache and weakness for about 3 years, initially diagnosed with hemiplegic migraine. Subsequently, her neurological manifestation progressed to transient ischemic attack (TIA and eventually to ischemic stroke confirmed by CT scan with 1-day history of expressive aphasia followed by persistent left side weakness and numbness. Detailed echocardiogram for the first time revealed a small LV apical thrombus with unchanged severe biventricular hypertrophy and normal systolic function. This unexpected LV apical thrombus may be associated with a wide spectrum of neurological deficits ranging from TIA to ischemic stroke in Danon disease. Possibility of cerebral ischemic events should be suspected in Danon disease when presenting with neurological deficits even with normal systolic function. Careful assessment for LV apical thrombus is warranted in such cases.

Fibrin d-dimer concentration, deep vein thrombosis symptom duration, and venous thrombus volume.

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Kurklinsky, Andrew K; Kalsi, Henna; Wysokinski, Waldemar E; Mauck, Karen F; Bhagra, Anjali; Havyer, Rachel D; Thompson, Carrie A; Hayes, Sharonne N; McBane, Robert D

2011-04-01

To determine the relationship between fibrin D-dimer levels, symptom duration, and thrombus volume, consecutive patients with incident deep venous thrombosis (DVT) were evaluated. In a cross-sectional study design, patient symptom onset was determined by careful patient questioning. Venous thrombosis was confirmed by compression duplex ultrasonography. Thrombus volume was estimated based on patient's femur length using a forensic anthropology method. Fibrin D-dimer was measured by latex immunoassay. 72 consecutive patients with confirmed leg DVT agreed to participate. The median symptom duration at the time of diagnosis was 10 days. The median D-dimer concentration was 1050 ng/dL. The median thrombus volume was 12.92 cm(3). D-Dimer levels correlated with estimated thrombus volume (P venous thrombosis and correlates with thrombus volume.

Saphenous vein graft thrombus findings by scanning electron microscopy in a patient with acute myocardial infarction

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Borges, Marcela Dias; Aguillera, André Haraguti [Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Brilhante, José Joaquim; Caixeta, Adriano [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil)

2013-07-01

An eighty-year-old male patient with a history of prior (19 years) coronary artery bypass graft surgery was admitted to the hospital with non ST-segment elevation myocardial infarction (NSTEMI). During the hospital stay he was taking acetylsalicylic acid 100mg per day, a loading dose of 600mg clopidogrel, and low molecular weight heparin 1mg/kg twice a day. Twenty-four hours later the patient underwent coronary angiography, which showed a 90% obstruction in the mid portion of the saphenous vein graft to obtuse marginal with signs of degeneration and local thrombus (Figure 1). Thrombus aspiration was performed with a 6-Fr Export{sup ™} catheter (Medtronic, Santa Rosa, CA, USA), which removed small reddish colored fragments. They were fixed in 2,5% glutaraldehyde in a 0.1M sodium cacodilate buffer. The material was processed following the GOTO protocol in which the fragments were washed with osmium tetroxide and titanic acid, after which they were dried in a critical-point device and a golden bath. Scanning electron microscopy and high definition photos (3,000 to 27,221x magnification) were obtained by the FEI Quanta{sup ™} FEG SEM device (FEI Company, Hillsboro, OR, USA). The images showed that the thrombus was rich in activated platelets, with few erythrocytes or inflammatory cells. Many cholesterol crystals were observed (Figures 2 to). The fibrin networks were sparse and thin, which is compatible with a short ischemic time and recent thrombus formation.

Saphenous vein graft thrombus findings by scanning electron microscopy in a patient with acute myocardial infarction

International Nuclear Information System (INIS)

Borges, Marcela Dias; Aguillera, André Haraguti; Brilhante, José Joaquim; Caixeta, Adriano

2013-01-01

An eighty-year-old male patient with a history of prior (19 years) coronary artery bypass graft surgery was admitted to the hospital with non ST-segment elevation myocardial infarction (NSTEMI). During the hospital stay he was taking acetylsalicylic acid 100mg per day, a loading dose of 600mg clopidogrel, and low molecular weight heparin 1mg/kg twice a day. Twenty-four hours later the patient underwent coronary angiography, which showed a 90% obstruction in the mid portion of the saphenous vein graft to obtuse marginal with signs of degeneration and local thrombus (Figure 1). Thrombus aspiration was performed with a 6-Fr Export"™ catheter (Medtronic, Santa Rosa, CA, USA), which removed small reddish colored fragments. They were fixed in 2,5% glutaraldehyde in a 0.1M sodium cacodilate buffer. The material was processed following the GOTO protocol in which the fragments were washed with osmium tetroxide and titanic acid, after which they were dried in a critical-point device and a golden bath. Scanning electron microscopy and high definition photos (3,000 to 27,221x magnification) were obtained by the FEI Quanta"™ FEG SEM device (FEI Company, Hillsboro, OR, USA). The images showed that the thrombus was rich in activated platelets, with few erythrocytes or inflammatory cells. Many cholesterol crystals were observed (Figures 2 to). The fibrin networks were sparse and thin, which is compatible with a short ischemic time and recent thrombus formation

Statins improve the resolution of established murine venous thrombosis: reductions in thrombus burden and vein wall scarring.

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Chase W Kessinger

Full Text Available Despite anticoagulation therapy, up to one-half of patients with deep vein thrombosis (DVT will develop the post-thrombotic syndrome (PTS. Improving the long-term outcome of DVT patients at risk for PTS will therefore require new approaches. Here we investigate the effects of statins--lipid-lowering agents with anti-thrombotic and anti-inflammatory properties--in decreasing thrombus burden and decreasing vein wall injury, mediators of PTS, in established murine stasis and non-stasis chemical-induced venous thrombosis (N = 282 mice. Treatment of mice with daily atorvastatin or rosuvastatin significantly reduced stasis venous thrombus burden by 25% without affecting lipid levels, blood coagulation parameters, or blood cell counts. Statin-driven reductions in VT burden (thrombus mass for stasis thrombi, intravital microscopy thrombus area for non-stasis thrombi compared similarly to the therapeutic anticoagulant effects of low molecular weight heparin. Blood from statin-treated mice showed significant reductions in platelet aggregation and clot stability. Statins additionally reduced thrombus plasminogen activator inhibitor-1 (PAI-1, tissue factor, neutrophils, myeloperoxidase, neutrophil extracellular traps (NETs, and macrophages, and these effects were most notable in the earlier timepoints after DVT formation. In addition, statins reduced DVT-induced vein wall scarring by 50% durably up to day 21 in stasis VT, as shown by polarized light microscopy of picrosirius red-stained vein wall collagen. The overall results demonstrate that statins improve VT resolution via profibrinolytic, anticoagulant, antiplatelet, and anti-vein wall scarring effects. Statins may therefore offer a new pharmacotherapeutic approach to improve DVT resolution and to reduce the post-thrombotic syndrome, particularly in subjects who are ineligible for anticoagulation therapy.

Statins improve the resolution of established murine venous thrombosis: reductions in thrombus burden and vein wall scarring.

Science.gov (United States)

Kessinger, Chase W; Kim, Jin Won; Henke, Peter K; Thompson, Brian; McCarthy, Jason R; Hara, Tetsuya; Sillesen, Martin; Margey, Ronan J P; Libby, Peter; Weissleder, Ralph; Lin, Charles P; Jaffer, Farouc A

2015-01-01

Despite anticoagulation therapy, up to one-half of patients with deep vein thrombosis (DVT) will develop the post-thrombotic syndrome (PTS). Improving the long-term outcome of DVT patients at risk for PTS will therefore require new approaches. Here we investigate the effects of statins--lipid-lowering agents with anti-thrombotic and anti-inflammatory properties--in decreasing thrombus burden and decreasing vein wall injury, mediators of PTS, in established murine stasis and non-stasis chemical-induced venous thrombosis (N = 282 mice). Treatment of mice with daily atorvastatin or rosuvastatin significantly reduced stasis venous thrombus burden by 25% without affecting lipid levels, blood coagulation parameters, or blood cell counts. Statin-driven reductions in VT burden (thrombus mass for stasis thrombi, intravital microscopy thrombus area for non-stasis thrombi) compared similarly to the therapeutic anticoagulant effects of low molecular weight heparin. Blood from statin-treated mice showed significant reductions in platelet aggregation and clot stability. Statins additionally reduced thrombus plasminogen activator inhibitor-1 (PAI-1), tissue factor, neutrophils, myeloperoxidase, neutrophil extracellular traps (NETs), and macrophages, and these effects were most notable in the earlier timepoints after DVT formation. In addition, statins reduced DVT-induced vein wall scarring by 50% durably up to day 21 in stasis VT, as shown by polarized light microscopy of picrosirius red-stained vein wall collagen. The overall results demonstrate that statins improve VT resolution via profibrinolytic, anticoagulant, antiplatelet, and anti-vein wall scarring effects. Statins may therefore offer a new pharmacotherapeutic approach to improve DVT resolution and to reduce the post-thrombotic syndrome, particularly in subjects who are ineligible for anticoagulation therapy.

Rivaroxaban attenuates thrombosis by targeting the NF-κB signaling pathway in a rat model of deep venous thrombus.

Science.gov (United States)

Ma, Junhao; Li, Xinxi; Wang, Yang; Yang, Zhenwei; Luo, Jun

2017-12-01

Anticoagulant therapy is commonly used for the prevention and treatment of patients with deep venous thrombus. Evidence has shown that rivaroxaban is a potential oral anticoagulant drug for the acute treatment of venous thromboembolism. However, the rivaroxaban-mediated molecular mechanism involved in the progression of deep venous thrombosis has not been investigated. In the present study, we investigated the efficacy of rivaroxaban and the underlying signaling pathways in the prevention and treatment of rats with deep venous thrombosis. A rat model with deep vein thrombus formation was established and received treatment with rivaroxaban or PBS as control. The thrombin-activatable fibrinolysis inhibitor (TAFI) and plasminogen activator inhibitor-1 (PAI-1) were analyzed both in vitro and in vivo. The progression of thrombosis and stroke was evaluated after treatment with rivaroxaban or PBS. Nuclear factor-κB (NF-κB) signaling pathway in venous endothelial cells and in the rat model of deep venous thrombus was assessed. The therapeutic effects of rivaroxaban were evaluated as determined by changes in deep venous thrombosis in the rat model. Our results showed that rivaroxaban markedly inhibited TAFI and PAI-1 expression levels, neutrophils, tissue factor, neutrophil extracellular traps (NETs), myeloperoxidase and macrophages in venous endothelial cells and in the rat model of deep venous thrombus. Expression levels of ADP, PAIs, von Willebrand factor (vWF) and thromboxane were downregulated in vein endothelial cells and in serum from the experimental rats. Importantly, the incidences of inferior vena cava filter thrombus were protected by rivaroxaban during heparin-induced thrombolysis deep venous thrombosis in the rat model. We observed that activity of the NF-κB signaling pathway was inhibited by rivaroxaban in vein endothelial cells both in vitro and in vivo. Notably, immunohistology indicated that rivaroxaban attenuated deep venous thrombosis and the

Floating arterial thrombus related stroke treated by intravenous thrombolysis.

Science.gov (United States)

Vanacker, P; Cordier, M; Janbieh, J; Federau, C; Michel, P

2014-01-01

The effects of intravenous thrombolysis on floating thrombi in cervical and intracranial arteries of acute ischemic stroke patients are unknown. Similarly, the best prevention methods of early recurrences remain controversial. This study aimed to describe the clinical and radiological outcome of thrombolyzed strokes with floating thrombi. We retrospectively analyzed all thrombolyzed stroke patients in our institution between 2003 and 2010 with floating thrombi on acute CT-angiography before the intravenous thrombolysis. The floating thrombus was diagnosed if an elongated thrombus of at least 5 mm length, completely surrounded by contrast on supra-aortic neck or intracerebral arteries, was present on CT-angiography. Demographics, vascular risk factors, and comorbidities were recorded and stroke etiology was determined after a standardized workup. Repeat arterial imaging was performed by CTA at 24 h or before if clinical worsening was noted and then by Doppler and MRA during the first week and at four months. Of 409 thrombolyzed stroke patients undergoing acute CT Angiography, seven (1.7%) had a floating thrombus; of these seven, six had it in the anterior circulation. Demographics, risk factors and stroke severity of these patients were comparable to the other thrombolyzed patients. After intravenous thrombolysis, the floating thrombi resolved completely at 24 h in four of the patients, whereas one had an early recurrent stroke and one developed progressive worsening. One patient developed early occlusion of the carotid artery with floating thrombus and subsequently a TIA. The two patients with a stable floating thrombus had no clinical recurrences. In the literature, only one of four reported cases were found to have a thrombolysis-related early recurrence. Long-term outcome seemed similar in thrombolyzed patients with floating thrombus, despite a possible increase of very early recurrence. It remains to be established whether acute mechanical thrombectomy could be

Safety of primary percutaneous coronary intervention with and without (selective) thrombus aspiration

International Nuclear Information System (INIS)

Farman, M. T.; Saghir, T.; Rizvi, N. H.; Khan, N.; Zaman, K. S.; Sial, J. A.; Malik, A.

2014-01-01

Objective: To determine the safety and efficacy of selective thrombus aspiration during Primary Percutaneous Coronary Intervention (PCI). Methods: This observational prospective study was conducted in the catheterization laboratory of a tertiary care cardiovascular centre. A total of 150 consecutive patients who underwent primary PCI were enrolled. Aspiration was done only when thrombus burden was considered significant. After completion of procedure angiographic and electrocardiographic signs were recorded and clinical follow up was documented up to 1 year. Results: No significant difference among the groups was found in age, height, weight and other risk factors like Hypertension, Diabetes Mellitus and Smoking. In general, left anterior descending artery was culprit in 65 % of patients and more than 90 % of culprit vessels had visible thrombus. Multivessel disease was present in 38 % of patients and 22.7% had past history of myocardial infarction. Out of 150 patients 117 (78%) underwent thrombus aspiration. No significant difference was found in ST resolution within 60 minutes (72.6 vs 81.8 %; P<0.285) and myocardial blush grade II and III (41.9 vs 27.3 %; P<0.128). No difference in event free survival was observed among the two groups (80.3 vs 84.8 %; P<0.708) at one year. Conclusion: Selective thrombus aspiration in definite thrombus laden arteries and no aspiration in low or negligible thrombus burden vessels may be a safe and effective strategy in patients undergoing primary PCI. Overall poor risk profile of our patients as compared to western population necessitates further evaluation of this matter in randomized studies. (author)

Thrombus length discrepancy on dual-phase CT can predict clinical outcome in acute ischemic stroke

International Nuclear Information System (INIS)

Park, Mina; Kim, Kyung-eun; Lee, Seung-Koo; Shin, Na-Young; Lim, Soo Mee; Song, Dongbeom; Heo, Ji Hoe; Kim, Jin Woo; Oh, Se Won

2016-01-01

The thrombus length may be overestimated on early arterial computed tomography angiography (CTA) depending on the collateral status. We evaluated the value of a grading system based on the thrombus length discrepancy on dual-phase CT in outcome prediction. Forty-eight acute ischemic stroke patients with M1 occlusion were included. Dual-phase CT protocol encompassed non-contrast enhanced CT, CTA with a bolus tracking technique, and delayed contrast enhanced CT (CECT) performed 40s after contrast injection. The thrombus length discrepancy between CTA and CECT was graded by using a three-point scale: G0 = no difference; G1 = no difference in thrombus length, but in attenuation distal to thrombus; G2 = difference in thrombus length. Univariate and multivariate analyses were performed to define independent predictors of poor clinical outcome at 3 months. The thrombus discrepancy grade showed significant linear relationships with both the collateral status (P = 0.008) and the presence of antegrade flow on DSA (P = 0.010) with good interobserver agreement (κ = 0.868). In a multivariate model, the presence of thrombus length discrepancy (G2) was an independent predictor of poor clinical outcome [odds ratio = 11.474 (1.350-97.547); P =0.025]. The presence of thrombus length discrepancy on dual-phase CT may be a useful predictor of unfavourable clinical outcome in acute M1 occlusion patients. (orig.)

Compact toroid formation, compression, and acceleration

International Nuclear Information System (INIS)

Degnan, J.H.; Bell, D.E.; Baca, G.P.; Dearborn, M.E.; Douglas, M.R.; Englert, S.E.; Englert, T.J.; Holmes, J.H.; Hussey, T.W.; Kiuttu, G.F.; Lehr, F.M.; Marklin, G.J.; Mullins, B.W.; Peterkin, R.E.; Price, D.W.; Roderick, N.F.; Ruden, E.L.; Turchi, P.J.; Coffey, S.K.; Seiler, S.W.; Bird, G.

1992-01-01

Research on the formation, compression, and acceleration of milligram Compact Toroids (CTs) will be discussed. This includes experiments with 2-stage coaxial gun discharges and calculations including 2D- MHD. The CTs are formed by 110 μf, 70 KV, 2 MA, 3 μs rise time discharges into 2 mg gas puffs in a 90 cm inner diameter, 7.6 cm gap coaxial gun with approximately 0.15 Tesla of radial-axial initial magnetic field. Reconnection at the neck of the toroidal magnetized plasma bubble extracted from the first stage gun forms the CT. Trapping, relaxation to a minimum energy Taylor state is observed with magnetic probe arrays. Low energy (few hundred KJ, 2 MA) acceleration in straight coaxial geometry, and high energy acceleration using a conical compression stage are discussed. The Phillips Laboratory 1,300 μf, 120 KV, 9.4 MJ SHIVA STAR capacitor bank is used for the acceleration discharge. The charging and triggering of the 36-module bank has been modified to permit use of any multiple of three modules. Highlights of fast photography, current, voltage, magnetic probe array, optical spectroscopy, interferometry, VUV, and higher energy radiation data and 2D-MHD calculations will be presented. Considerably more detail is presented in companion papers

Computed tomographic and ultrasonographic diagnosis of portal vein tumor thrombus in hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Mori, H; Futagawa, S; Hayashi, K; Amagasaki, Y; Ochi, M [Nagasaki Univ. (Japan). School of Medicine

1982-04-01

Nine cases of hepatocellular carcinoma which have invaded the intra- and extrahepatic portal vein were evaluated by computed tomography (CT) and ultrasonography (US). The outstanding CT and sonographic features of the portal vein tumor thrombus were described. In CT, contrast opacification of normal portal vein and its major tributaries were not observed, and they were replaced by a soft tissue density mass representing the tumor thrombus. The thrombus measured 35 - 45 Hounsfield units (HU) in precontrast scans and 60 - 80 HU in postcontrast scans. The portal vein tumor thrombus showed a branched pattern of low density in porta hepatis and intrahepatic region due to differences in attenuation coefficients of the thrombus and adjacent noncancerous hepatic parenchyma on postcontrast scans. In ultrasound study, tumor thrombus was recognized as an echogenic solid mass in the porta hepatis obliterating the normal portal venous structures, or as an intraluminal solid mass in the dilated portal vein and its branches. Numerous collateral venous channels surrounding the thrombosed portal vein were also demonstrated on both CT and US. Particular emphasis was placed on the clinical implications of these non-invasive detection of the portal vein tumor thrombosis in patients with hepatocellular carcinoma.

Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

International Nuclear Information System (INIS)

Santos, Emilie M.M.; Yoo, Albert J.; Beenen, Ludo F.; Majoie, Charles B.; Berkhemer, Olvert A.; Blanken, Mark D. den; Wismans, Carrie; Niessen, Wiro J.; Marquering, Henk A.

2016-01-01

Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert observers. For 132 consecutive patients with acute ischemic stroke, three experts and two trained observers determined thrombus density by placing three standardized regions of interest (ROIs) in the thrombus and corresponding contralateral arterial segment. Subsequently, absolute and relative thrombus densities were determined using either one or three ROIs. Intraclass correlation coefficient (ICC) was determined, and Bland-Altman analysis was performed to evaluate interobserver and intermethod agreement. Accuracy of the trained observer was evaluated with a reference expert observer using the same statistical analysis. The highest interobserver agreement was obtained for absolute thrombus measurements using three ROIs (ICCs ranging from 0.54 to 0.91). In general, interobserver agreement was lower for relative measurements, and for using one instead of three ROIs. Interobserver agreement of trained non-experts and experts was similar. Accuracy of the trained observer measurements was comparable to the expert interobserver agreement and was better for absolute measurements and with three ROIs. The agreement between the one ROI and three ROI methods was good. Absolute thrombus density measurement has superior interobserver agreement compared to relative density measurement. Interobserver variation is smaller when multiple ROIs are used. Trained non-expert observers can accurately and reproducibly assess absolute thrombus densities using three ROIs. (orig.)

Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

Energy Technology Data Exchange (ETDEWEB)

Santos, Emilie M.M. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, Rotterdam (Netherlands); Department of Radiology, AMC, Amsterdam (Netherlands); Yoo, Albert J. [Texas Stroke Institute, Plano, TX (United States); Beenen, Ludo F.; Majoie, Charles B. [Department of Radiology, AMC, Amsterdam (Netherlands); Berkhemer, Olvert A. [Department of Radiology, AMC, Amsterdam (Netherlands); Department of Neurology, Erasmus MC, Rotterdam (Netherlands); Blanken, Mark D. den; Wismans, Carrie [AMC, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Niessen, Wiro J. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, Rotterdam (Netherlands); Delft University of Technology, Faculty of Applied Sciences, Delft (Netherlands); Marquering, Henk A. [Department of Radiology, AMC, Amsterdam (Netherlands); AMC, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Collaboration: on behalf of the MR CLEAN investigators

2016-02-15

Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert observers. For 132 consecutive patients with acute ischemic stroke, three experts and two trained observers determined thrombus density by placing three standardized regions of interest (ROIs) in the thrombus and corresponding contralateral arterial segment. Subsequently, absolute and relative thrombus densities were determined using either one or three ROIs. Intraclass correlation coefficient (ICC) was determined, and Bland-Altman analysis was performed to evaluate interobserver and intermethod agreement. Accuracy of the trained observer was evaluated with a reference expert observer using the same statistical analysis. The highest interobserver agreement was obtained for absolute thrombus measurements using three ROIs (ICCs ranging from 0.54 to 0.91). In general, interobserver agreement was lower for relative measurements, and for using one instead of three ROIs. Interobserver agreement of trained non-experts and experts was similar. Accuracy of the trained observer measurements was comparable to the expert interobserver agreement and was better for absolute measurements and with three ROIs. The agreement between the one ROI and three ROI methods was good. Absolute thrombus density measurement has superior interobserver agreement compared to relative density measurement. Interobserver variation is smaller when multiple ROIs are used. Trained non-expert observers can accurately and reproducibly assess absolute thrombus densities using three ROIs. (orig.)

Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

NARCIS (Netherlands)

E.M.M. Santos (Emilie M.); A.J. Yoo (Albert J.); L.F.M. Beenen (Ludo); O.A. Berkhemer (Olvert); M.D. Den Blanken (Mark D.); C. Wismans (Carrie); W.J. Niessen (Wiro); C.B. Majoie (Charles); H. Marquering (Henk)

2016-01-01

textabstractIntroduction: Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by

Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

NARCIS (Netherlands)

Santos, Emilie M. M.; Yoo, Albert J.; Beenen, Ludo F.; Berkhemer, Olvert A.; den Blanken, Mark D.; Wismans, Carrie; Niessen, Wiro J.; Majoie, Charles B.; Marquering, Henk A.; Fransen, Puck S. S.; Beumer, Debbie; van den Berg, Lucie A.; Lingsma, Hester F.; Schonewille, Wouter J.; Vos, Jan Albert; Nederkoorn, Paul J.; Wermer, Marieke J. H.; van Walderveen, Marianne A. A.; Staals, Julie; Hofmeijer, Jeannette; van Oostayen, Jacques A.; Lycklama à Nijeholt, Geert J.; Boiten, Jelis; Brouwer, Patrick A.; Emmer, Bart J.; de Bruijn, Sebastiaan F.; van Dijk, Lukas C.; Kappelle, L. Jaap; Lo, Rob H.; van Dijk, Ewoud J.; de Vries, Joost; de Kort, Paul L. M.; van den Berg, Jan S. P.; A A M van Hasselt, Boudewijn; Aerden, Leo A. M.; Dallinga, René J.; Visser, Marieke C.; Bot, Joseph C. J.; Vroomen, Patrick C.; Eshghi, Omid; Schreuder, Tobien H. C. M. L.; Heijboer, Roel J. J.; Keizer, Koos; Tielbeek, Alexander V.; Hertog, Heleen M. Den; Gerrits, Dick G.; van den Berg-Vos, Renske M.; Karas, Giorgos B.; Steyerberg, Ewout W.; Flach, H. Zwenneke; Sprengers, Marieke E. S.; Jenniskens, Sjoerd F. M.; van den Berg, René; Koudstaal, Peter J.; van Zwam, Wim H.; Roos, Yvo B. W. E. M.; van der Lugt, Aad; van Oostenbrugge, Robert J.; Dippel, Diederik W. J.

2016-01-01

Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert

Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

NARCIS (Netherlands)

Santos, E.M.; Yoo, A.J.; Beenen, L.F.; Berkhemer, O.A.; Blanken, M.D. den; Wismans, C.; Niessen, W.J.; Majoie, C.B.; Marquering, H.A.; Dijk, E.J. van; et al.,

2016-01-01

INTRODUCTION: Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and

Optical coherence tomography assessment and quantification of intracoronary thrombus: Status and perspectives

International Nuclear Information System (INIS)

Porto, Italo; Mattesini, Alessio; Valente, Serafina; Prati, Francesco; Crea, Filippo; Bolognese, Leonardo

2015-01-01

Coronary angiography is the “golden standard” imaging technique in interventional cardiology and it is still widely used to guide interventions. A major drawback of this technique, however, is that it is inaccurate in the evaluation and quantification of intracoronary thrombus burden, a critical prognosticator and predictor of intraprocedural complications in acute coronary syndromes. The introduction of optical coherence tomography (OCT) holds the promise of overcoming this important limitation, as near-infrared light is uniquely sensitive to hemoglobin, the pigment of red blood cells trapped in the thrombus. This narrative review will focus on the use of OCT for the assessment, evaluation and quantification of intracoronary thrombosis. - Highlights: • Thrombotic burden in acute coronary syndromes Is not adequately evaluated by standard coronary angiography, whereas Optical Coherence Tomography is exquisitely sensitive to the hemoglobin contained in red blood cells and can be used to precisely quantify thrombus. • Both research and clinical applications have been developed using the OCT-based evaluation of thrombus. In particular, whereas precise quantification scores are useful for comparing antithrombotic therapies in randomized trials, both pharmacological and mechanical, the most important practical applications for OCT-based assessment of thrombus are the individuation of culprit lesions in the context of diffuse atheromata in acute coronary syndromes, and the so-called “delayed stenting” strategies. • Improvements in 3D rendering techniques are on the verge of revolutionizing OCT-based thrombus assessment, allowing extremely precise quantification of the thrombotic burden

Optical coherence tomography assessment and quantification of intracoronary thrombus: Status and perspectives

Energy Technology Data Exchange (ETDEWEB)

Porto, Italo, E-mail: italo.porto@gmail.com [Interventional Cardiology Unit, San Donato Hospital, Arezzo (Italy); Mattesini, Alessio; Valente, Serafina [Interventional Cardiology Unit, Careggi Hospital, Florence (Italy); Prati, Francesco [Interventional Cardiology San Giovanni Hospital, Rome (Italy); CLI foundation (Italy); Crea, Filippo [Department of Cardiovascular Sciences, Catholic University of the Sacred Heart, Rome (Italy); Bolognese, Leonardo [Interventional Cardiology Unit, San Donato Hospital, Arezzo (Italy)

2015-04-15

Coronary angiography is the “golden standard” imaging technique in interventional cardiology and it is still widely used to guide interventions. A major drawback of this technique, however, is that it is inaccurate in the evaluation and quantification of intracoronary thrombus burden, a critical prognosticator and predictor of intraprocedural complications in acute coronary syndromes. The introduction of optical coherence tomography (OCT) holds the promise of overcoming this important limitation, as near-infrared light is uniquely sensitive to hemoglobin, the pigment of red blood cells trapped in the thrombus. This narrative review will focus on the use of OCT for the assessment, evaluation and quantification of intracoronary thrombosis. - Highlights: • Thrombotic burden in acute coronary syndromes Is not adequately evaluated by standard coronary angiography, whereas Optical Coherence Tomography is exquisitely sensitive to the hemoglobin contained in red blood cells and can be used to precisely quantify thrombus. • Both research and clinical applications have been developed using the OCT-based evaluation of thrombus. In particular, whereas precise quantification scores are useful for comparing antithrombotic therapies in randomized trials, both pharmacological and mechanical, the most important practical applications for OCT-based assessment of thrombus are the individuation of culprit lesions in the context of diffuse atheromata in acute coronary syndromes, and the so-called “delayed stenting” strategies. • Improvements in 3D rendering techniques are on the verge of revolutionizing OCT-based thrombus assessment, allowing extremely precise quantification of the thrombotic burden.

Erythrocyte-rich thrombus aspirated from patients with ST-elevation myocardial infarction: association with oxidative stress and its impact on myocardial reperfusion

NARCIS (Netherlands)

Yunoki, Kei; Naruko, Takahiko; Sugioka, Kenichi; Inaba, Mayumi; Iwasa, Yoko; Komatsu, Ryushi; Itoh, Akira; Haze, Kazuo; Inoue, Takeshi; Yoshiyama, Minoru; Becker, Anton E.; Ueda, Makiko

2012-01-01

Recent studies have demonstrated that erythrocytes are a potential component in atheromatous lesions and thrombus formation in patients with ST-elevation myocardial infarction (STEMI). The purpose of this study was to determine the associations of red blood cell (RBC) component of coronary thrombi

Intracardiac thrombus in Behçet’s disease

Directory of Open Access Journals (Sweden)

I. Ben Ghorbel

2016-12-01

Full Text Available Behçet’s disease (BD is a multisystem inflammatory disorder. Intracardiac thrombus (ICT formation is an uncommon but important complication of BD. Of the cases of Behçet’s disease, we selected those with ICT. All patients fulfilled the diagnostic criteria of the International Study Group of Behçet’s disease. The ICT in each case was confirmed by ultrasonography, computed tomography and MRI. Clinical features and laboratory parameters were determined. Among our 518 patients with BD, 8 were diagnosed as having intracardiac thrombus (ICT. All were male; the mean age at the time of the ICT diagnosis was 30.8 years. The main presenting symptoms were hemoptysis, chest pain, and dyspnea. It was associated with pulmonary artery aneurysm and vena cava thrombosis in 3 cases each, pulmonary embolism, and lower limbs deep venous thrombosis in 1 case each. The coexistence of other cardiac complications was as follows: pericarditis in 2 cases, myocarditis, endomyocardial fibrosis, and coronary arteritis with consequent myocardial infarction in one case each. In all cases, echocardiography was sufficient to reach the diagnosis. Chest computed tomography performed in all cases led to the diagnosis of associated pulmonary vasculo-Behçet lesions in 4 cases. All patients received colchicine, anticoagulation, and corticosteroids. Seven patients were on immunosuppressant agents (2 patients received azathioprine and 5 cyclophosphamide. Clinical remission with ICT resolution was observed in 5 cases. Combined immunosuppressive therapy with prednisone and cyclophosphamide might be needed to treat ICT due to BD.

The free-radical scavenger edaravone accelerates thrombolysis with alteplase in an experimental thrombosis model.

Science.gov (United States)

Yamashita, Tsutomu; Sato, Takumi; Sakamoto, Kumi; Ishii, Hiromitsu; Yamamoto, Junichiro

2015-06-01

Reperfusion injury after thrombolytic therapy can have adverse neurologic effects. The free-radical scavenger edaravone is used in combination with the recombinant tissue plasminogen activator alteplase to treat acute ischemic stroke. However, basic investigations of this combination use remain inadequate. Here, we used an in vivo model to investigate the effects of edaravone on alteplase-induced thrombolysis. Thrombolysis was evaluated by using a He-Ne-laser-induced thrombosis model in rat mesenteric microvessels. Changes in thrombus volume were analyzed with the image analysis software Image-Pro Plus (Media Cybernetics, USA). There were three experimental groups (placebo, alteplase 0.6 mg/kg, alteplase 0.6 mg/kg + edaravone 10.5 mg/kg). Sequential changes (0 to 60 min) in thrombus volume were compared by using a relative optical density method that we had used previously. In the placebo group, the thrombus volume at 60 min, reflecting the extent of thrombolysis, was 97.2% ± 5.7% of the initial value. In the alteplase group, thrombus volume decreased to 70.7% ± 4.1% (Pedaravone group, thrombus volume decreased to 66.9% ± 7.2% (Pedaravone accelerates thrombolysis by alteplase. Copyright © 2015 Elsevier Ltd. All rights reserved.

Iliac artery mural thrombus formation. Effect of antiplatelet therapy on 111In-platelet deposition in baboons

International Nuclear Information System (INIS)

Hanson, S.R.; Paxton, L.D.; Harker, L.A.

1986-01-01

To measure the rate, extent, and time course of arterial mural thrombus formation in vivo and to assess the effects of antiplatelet therapy in that setting, we have studied autologous 111 In-platelet deposition induced by experimental iliac artery aneurysms in baboons. Scintillation camera imaging analyses were performed at 1, 24, 48, and 72 hours after implantation of the device. Correction for tissue attenuation was determined by using a small, comparably located 111 In source implanted at the time of surgery. In five animals, 111 In-platelet activity accumulated progressively after device implantation, reaching a maximum after the third day. Repeat image analysis carried out 2 weeks after the surgical procedure also showed progressive accumulation of 111 In-platelets over 3 days but at markedly reduced amounts as compared with the initial study. In five additional animals, treatment with a combination of aspirin and dipyridamole begun 1 hour after surgical implantation reduced 111 In-platelet deposition to negligible levels by the third day. Although platelet survival time was shortened and platelet turnover was reciprocally increased in all operated animals, platelet survival and turnover were not affected by antiplatelet therapy. We conclude that, in contrast to platelet survival and turnover measurements, 111 In-platelet imaging is a reliable and sensitive method for localizing and quantifying focal arterial thrombi and for assessing the effects of antiplatelet therapy

Effect of Adjunctive Thrombus Aspiration on In-Hospital and 3-Year Outcomes in Patients With ST-Segment Elevation Myocardial Infarction and Large Native Coronary Artery Thrombus Burden.

Science.gov (United States)

Keskin, Muhammed; Kaya, Adnan; Tatlısu, Mustafa Adem; Uzman, Osman; Börklü, Edibe Betül; Çinier, Göksel; Tekkeşin, Ahmet İlker; Türkkan, Ceyhan; Hayıroğlu, Mert İlker; Kozan, Ömer

2017-11-15

Although the long-term clinical benefit of adjunctive thrombus aspiration (TA) during primary percutaneous coronary intervention (PPCI) remains controversial, the impact of TA in patients with large thrombus has not been evaluated. The aim of the present study was to investigate the effect of adjunctive TA during PPCI on clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) and a large thrombus. We assessed the effect of adjunctive TA on in-hospital and 3-year clinical outcomes in 627 patients with STEMI and a large thrombus in the native coronary artery. The cumulative 3-year incidence of all-cause death was not significantly different between the 2 groups (91.5% vs 89.0%, log-rank test p = 0.347). After adjusting for confounders, the risk of all-cause death in the TA group was not significantly lower than that in the non-TA group (hazard ratio 1.11, 95% confidence interval 0.60 to 3.54, p = 0.674). The adjusted risks of target lesion revascularization, nonfatal acute myocardial infarction, and stent thrombosis were also not significantly different between the 2 groups. In conclusion, adjunctive TA during PPCI was not associated with better in-hospital and 3-year all-cause deaths in patients with STEMI and a large coronary artery thrombus. Copyright © 2017 Elsevier Inc. All rights reserved.

[Recurrent right atrial thrombus in a patient with atrial fibrillation and heart failure].

Science.gov (United States)

Elikowski, Waldemar; Wróblewski, Dariusz; Małek-Elikowska, Małgorzata; Mazurek, Andrzej; Foremska-Iciek, Joanna; Łazowski, Stanisław

2015-11-01

Atrial fibrillation and heart failure are factors predisposing to locally formed intracardiac thrombosis, which is usually localized in left-sided chambers. A case report. The authors present a case of a 50-year-old male with permanent atrial fibrillation and dilated cardiomyopathy in whom recurrent right atrial thrombus was observed. Initially, the lesion was detected in echocardiography while he was hospitalized due to extensive right-sided pneumonia. The thrombus was successfully treated with heparin, followed by warfarin. Even though the patient continued warfarin use properly, there was recurrence of the thrombus two years later during a new episode of heart failure exacerbation. Because the thrombus was resistant to intensified anticoagulation, cardiac surgery was needed. A large (30 x 25 mm) pedunculated thrombus, as well as two smaller ones (each of 10 x 10 mm) attached closely to the atrial wall and previously not detected either by echocardiography or by magnetic resonance imaging, were excited. A partially organized pattern of the thrombi in histological examination can explain lack of anticoagulation effectiveness. © 2015 MEDPRESS.

Computer simulations of compact toroid formation and acceleration

International Nuclear Information System (INIS)

Peterkin, R.E. Jr.; Sovinec, C.R.

1990-01-01

Experiments to form, accelerate, and focus compact toroid plasmas will be performed on the 9.4 MJ SHIVA STAR fast capacitor bank at the Air Force Weapons Laboratory during the 1990. The MARAUDER (magnetically accelerated rings to achieve ultrahigh directed energy and radiation) program is a research effort to accelerate magnetized plasma rings with the masses between 0.1 and 1.0 mg to velocities above 10 8 cm/sec and energies above 1 MJ. Research on these high-velocity compact toroids may lead to development of very fast opening switches, high-power microwave sources, and an alternative path to inertial confinement fusion. Design of a compact toroid accelerator experiment on the SHIVA STAR capacitor bank is underway, and computer simulations with the 2 1/2-dimensional magnetohydrodynamics code, MACH2, have been performed to guide this endeavor. The compact toroids are produced in a magnetized coaxial plasma gun, and the acceleration will occur in a configuration similar to a coaxial railgun. Detailed calculations of formation and equilibration of a low beta magnetic force-free configuration (curl B = kB) have been performed with MACH2. In this paper, the authors discuss computer simulations of the focusing and acceleration of the toroid

Imaging thrombus with radiolabelled monoclonal antibody to platelets

International Nuclear Information System (INIS)

Loutfi, I.; Peters, A.M.; Lavender, J.P.; Epenetos, A.A.

1988-01-01

Indium-111-hydroxyquinoline labelled platelets, though useful in the detection of thrombus, have not gained widespread use owing to the time and technical skill required for their preparation. A study was therefore conducted evaluating a new method of imaging thrombus with platelets radiolabelled with a 111 In labelled monoclonal antibody, P 256 , directed to the platelet surface glycoprotein complex IIb/IIIa. When the number of receptors occupied by P 256 was less than 3% of the total available on the platelet surface platelet function, as assessed by platelet aggregometry, was undisturbed. P 256 was radiolabelled with 111 In using diethylenetriaminepenta-acetic acid, which achieved a specific activity of 185 MBq (5 mCi)/mg. No impairment of immunoreactivity was detected at this specific activity. Platelets were labelled with radiolabelled monoclonal antibody in vitro in two patients at a receptor occupancy of 6% and in vivo - that is, by direct intravenous injection of P 256 - in six patients at a receptor occupancy of 1%. In vivo recovery and biodistribution kinetics suggested that after in vitro labelling platelets were minimally activated. The 111 In kinetics recorded after intravenous P 256 suggested rapid and efficient radiolabelling of platelets and gave no indication of platelet activation. Of the six patients who received intravenous P 256 , three had documented thrombus, tow of whom gave positive results on P 256 platelet scintigraphy. The third subject had chromic deep venous thrombosis and was scintigraphically negative. Imaging thrombus using a radiolabelled monoclonal antibody directed to platelets appears to offer great potential as a simple, non-invasive approach to the diagnosis of thrombosis. 3 refs. (Author)

Ultrasound active nanoscaled lipid formulations for thrombus lysis.

Science.gov (United States)

Becker, Andreas; Marxer, Elena; Brüssler, Jana; Hoormann, Anne Sophia; Kuhnt, Daniela; Bakowsky, Udo; Nimsky, Christopher

2011-04-01

In the present study, we investigated the sonothrombolytic effect of new nanoscaled lipid formulations in human blood clots, using diagnostic ultrasound. Human blood clots of 1 ml were incubated with 1 μl of the different lipid dispersions DPPC/CH, DPPC/PEG40S, DSPC/PEG40S and the commercially available ultrasound contrast agent SonoVue®. Clots were stored for 3 days at 5 °C to obtain maximal clot retraction and lytic resistance. Each clot weight was determined before and after continuous insonation for 1h of insonation at 1.4 MHz. The pressure in the insonation chamber was 80 mm Hg to mimic middle arterial blood pressure. There were no significant differences in thrombus weight before insonation. All nanoscaled formulations and SonoVue® were able to reduce thrombus weight compared to the weight loss of clots that were not insonated but kept under pressure for one hour (p ultrasound enhanced thrombolysis even without thrombolytic drugs. Stable cavitation is a crucial parameter in fragmentation of thrombus architecture. Further studies of physicochemical properties of DSPC/PEG40S are necessary to corroborate our hypothesis. Copyright © 2010 Elsevier B.V. All rights reserved.

Angioplasty of symptomatic high-grade internal carotid artery stenosis with intraluminal thrombus: therapeutic approach

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, A.; Mayol, A. [Seccion de Neurorradiologia Intervencionista, Servicio de Radiologia, Hospital Universitario Virgen del Rocio, Avenida Manuel Siurot s/n, Avenida Manuel Siurot s/n, 41013, Sevilla (Spain); Gil-Peralta, A.; Gonzalez-Marcos, J.R. [Servicio de Neurologia, Hospital Universitario Virgen del Rocio, Avenida Manuel Siurot s/n, 41013, Sevilla (Spain); Boza, F. [Servicio de Neurofisiologia, Hospital Universitario Virgen del Rocio, Avenida Manuel Siurot s/n, 41013, Sevilla (Spain); Ruano, J. [Unidad de Cuidados Intensivos, Hospital Universitario Virgen del Rocio, Avenida Manuel Siurot s/n, 41013, Sevilla (Spain)

2004-04-01

Intraluminal thrombus in the internal carotid artery (ICA) is usually found in patients with severe atheromatous stenosis. Having reviewed 300 carotid angioplasties for symptomatic >70% ICA stenosis, we found three patients (1%) with intraluminal thrombus. Conservative treatment with anticoagulants and double antiplatelet coverage can result in lysis of the thrombus without severe risks. Percutaneous transluminal angioplasty and stenting, preferably with distal protection, can be an excellent alternative to carotid endarterectomy. (orig.)

Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

Energy Technology Data Exchange (ETDEWEB)

Mizandari, Malkhaz [High Technology Medical Center, Tbilisi State Medical University (Georgia); Ao, Guokun [The 309 Hospital of People' s Liberation Army, Department on Oncology (China); Zhang Yaojun; Feng Xi [Imperial College London, Department of Surgery and Cancer (United Kingdom); Shen Qiang [The First Minimally Invasive Department of Eastern Hepatobiliary Surgery Hospital (China); Chen Minshan [Cancer Centre of Sun Yat-Sen University, Department of Hepatobiliary Surgery (China); Lau, Wan Yee [Chinese University of Hong Kong, Department of Surgery, Faculty of Medicine (Hong Kong); Nicholls, Joanna; Jiao Long; Habib, Nagy, E-mail: nagy.habib@imperial.ac.uk [Imperial College London, Department of Surgery and Cancer (United Kingdom)

2013-02-15

We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

A thrombus in transit through a patent foramen ovale.

Science.gov (United States)

Ibebuogu, Uzoma N; Khouzam, Rami N; Sharma, Gyanendra; Thornton, John W; Robati, Roshanak; Silverman, David

2014-10-01

Patent foramen ovale (PFO) is a congenital heart defect that may first be diagnosed in adulthood and has a prevalence of 25% to 30%. Although many patients with PFO are asymptomatic and do not require treatment, paradoxical embolism can cause stroke or myocardial infarction. The authors report an unusual case of PFO with a transversing thrombus in an 80-year-old man. The patient's initial presentation appeared clinically as acute coronary syndrome, but he was subsequently diagnosed with a massive thrombus in transit via a PFO and pulmonary embolus leading to right-sided heart failure.

The Use of Fluid Mechanics to Predict Regions of Microscopic Thrombus Formation in Pulsatile VADs.

Science.gov (United States)

Topper, Stephen R; Navitsky, Michael A; Medvitz, Richard B; Paterson, Eric G; Siedlecki, Christopher A; Slattery, Margaret J; Deutsch, Steven; Rosenberg, Gerson; Manning, Keefe B

2014-03-01

We compare the velocity and shear obtained from particle image velocimetry (PIV) and computational fluid dynamics (CFD) in a pulsatile ventricular assist device (VAD) to further test our thrombus predictive methodology using microscopy data from an explanted VAD. To mimic physiological conditions in vitro , a mock circulatory loop is used with a blood analog that matched blood's viscoelastic behavior at 40% hematocrit. Under normal physiologic pressures and for a heart rate of 75 bpm, PIV data is acquired and wall shear maps are produced. The resolution of the PIV shear rate calculations are tested using the CFD and found to be in the same range. A bovine study, using a model of the 50 cc Penn State V-2 VAD, for 30 days at a constant beat rate of 75 beats per minute (bpm) provides the microscopic data whereby after the 30 days, the device is explanted and the sac surface analyzed using scanning electron microscopy (SEM) and, after immunofluorescent labeling for platelets and fibrin, confocal microscopy. Areas are examined based on PIV measurements and CFD, with special attention to low shear regions where platelet and fibrin deposition are most likely to occur. Data collected within the outlet port in a direction normal to the front wall of the VAD shows that some regions experience wall shear rates less than 500 s -1 , which increases the likelihood of platelet and fibrin deposition. Despite only one animal study, correlations between PIV, CFD, and in vivo data show promise. Deposition probability is quantified by the thrombus susceptibility potential, a calculation to correlate low shear and time of shear with deposition.

Incremental value of contrast echocardiography in the evaluation of a cardiac thrombus.

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Po, Jose Ricardo F; Tong, Matthew S; Grove, Erica L; Biederman, Robert W W

2017-02-01

A 52-year-old man presented with altered mental status and report of prior complaint of chest pain. On electrocardiography, anterolateral ST-segment elevations with Q-waves in the septal leads were seen. Initial echocardiography images demonstrated a thickened anteroseptum. Further imaging showed the presence of a well-attached laminated apical thrombus. Contrast echocardiography images showed that the thrombus had minimal attachment to the endocardial surface. CT head subsequently showed the presence of acute stroke. The case demonstrates the additional value of contrast echocardiography in the evaluation of cardiac masses despite the certainty in the diagnosis of a thrombus. © 2017, Wiley Periodicals, Inc.

Renal angiomyolipoma with inferior vena caval thrombus in a 32-year-old male

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Matthew W Christian

2009-01-01

Full Text Available Renal angiomyolipoma (AML rarely presents with evidence of extension into the renal vein, inferior vena cava (IVC or atrium. We report a case of a renal AML with a tumor thrombus to the IVC in a 32-year-old male. The patient subsequently underwent a right radical nephrectomy with IVC tumor thrombectomy. To our knowledge, there are four published cases of renal AML presenting with tumor thrombus in males. This case report describes the management of the youngest male ever to develop a renal AML with IVC tumor thrombus.

Chronic skin inflammation accelerates macrophage cholesterol crystal formation and atherosclerosis

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Ng, Qimin; Sanda, Gregory E.; Dey, Amit K.; Teague, Heather L.; Sorokin, Alexander V.; Dagur, Pradeep K.; Silverman, Joanna I.; Harrington, Charlotte L.; Rodante, Justin A.; Rose, Shawn M.; Varghese, Nevin J.; Belur, Agastya D.; Goyal, Aditya; Gelfand, Joel M.; Springer, Danielle A.; Bleck, Christopher K.E.; Thomas, Crystal L.; Yu, Zu-Xi; Winge, Mårten C.G.; Kruth, Howard S.; Marinkovich, M. Peter; Joshi, Aditya A.; Playford, Martin P.; Mehta, Nehal N.

2018-01-01

Inflammation is critical to atherogenesis. Psoriasis is a chronic inflammatory skin disease that accelerates atherosclerosis in humans and provides a compelling model to understand potential pathways linking these diseases. A murine model capturing the vascular and metabolic diseases in psoriasis would accelerate our understanding and provide a platform to test emerging therapies. We aimed to characterize a new murine model of skin inflammation (Rac1V12) from a cardiovascular standpoint to identify novel atherosclerotic signaling pathways modulated in chronic skin inflammation. The RacV12 psoriasis mouse resembled the human disease state, including presence of systemic inflammation, dyslipidemia, and cardiometabolic dysfunction. Psoriasis macrophages had a proatherosclerotic phenotype with increased lipid uptake and foam cell formation, and also showed a 6-fold increase in cholesterol crystal formation. We generated a triple-genetic K14-RacV12–/+/Srb1–/–/ApoER61H/H mouse and confirmed psoriasis accelerates atherogenesis (~7-fold increase). Finally, we noted a 60% reduction in superoxide dismutase 2 (SOD2) expression in human psoriasis macrophages. When SOD2 activity was restored in macrophages, their proatherogenic phenotype reversed. We demonstrate that the K14-RacV12 murine model captures the cardiometabolic dysfunction and accelerates vascular disease observed in chronic inflammation and that skin inflammation induces a proatherosclerotic macrophage phenotype with impaired SOD2 function, which associated with accelerated atherogenesis. PMID:29321372

Covered stent to exclude intravascular thrombus.

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Liistro, Francesco; Stankovic, Goran; Di Mario, Carlo; Montorfano, Matteo; Briguori, Carlo; Colombo, Antonio

2002-04-01

To describe the utility of stent-graft implantation to avoid distal embolization from a large thrombus-containing lesion. A 67-year-old man was evaluated for recent onset of disabling left leg claudication. Angiography disclosed a mobile lobular mass occluding the left common iliac artery; irregular staining suggested an atherothrombotic lesion. Through a percutaneous ipsilateral access and an 8-F sheath, a balloon-expandable Jostent peripheral stent-graft was positioned with the distal edge immediately proximal to the internal iliac artery ostium. A prominent "waist" at the center of the balloon confirmed entrapment of the thrombotic mass. Completion angiography showed an optimal result with no residual stenosis or evidence of distal embolization. At 6-month follow-up, the patient was asymptomatic with angiographically documented luminal patency and no evidence of in-stent stenosis. Stent-graft implantation appears a viable treatment alternative for thrombus-containing lesions, particularly when the thrombotic material is localized or is in a large vessel.

Added value of multiphase CTA imaging for thrombus perviousness assessment

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Santos, E.M.M. [Academic Medical Center, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Erasmus Medical Center, Department of Medical Informatics, Rotterdam (Netherlands); D' Esterre, C.D.; Najm, M.; Goyal, M.; Demchuk, A.M.; Menon, B.K. [University of Calgary, Departments of Neurosciences, Radiology and Community Health Sciences, Calgary (Canada); Treurniet, K.M.; Majoie, C.B. [Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Niessen, W.J. [Erasmus Medical Center, Department of Medical Informatics, Rotterdam (Netherlands); Delft University of Technology, Faculty of Applied Sciences, Delft (Netherlands); Marquering, H.A. [Academic Medical Center, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Mandzia, Jennifer; Fainardi, Enrico; Rubiera, Marta; Khaw, Alexander V.; Zini, Andrea; Shankar, JJ.; Collaboration: PRove-IT investigators

2018-01-15

Thrombus perviousness has been associated with favorable functional outcome in acute ischemic stroke (AIS) patients. Measuring thrombus perviousness on CTA may be suboptimal due to potential delay in contrast agent arrival in occluded arteries at the moment of imaging. Dynamic sequences acquired over time can potentially overcome this issue. We investigate if dynamic CTA has added value in assessing thrombus perviousness. Prospectively collected image data of AIS patients with proven occlusion of the anterior or posterior circulation with thin-slice multi-phase CTA (MCTA) and non-contrast CT were co-registered (n = 221). Thrombus attenuation increase (TAI; a perviousness measure) was measured for the arterial, venous, and delayed phase of the MCTA and time-invariant CTAs (TiCTA). Associations with favorable clinical outcome (90-day mRS ≤ 2) were assessed using univariate and multivariable regressions and calculating areas under receiver operating curves (AUC). TAI determined from the arterial phase CTA was superior in the association with favorable outcome with OR = 1.21 per 10 HU increase (95%CI 1.04-1.41, AUC 0.62, p = 0.014) compared to any other phase (venous 1.14(95%CI 1.01-1.30, AUC 0.58, p = 0.033), delayed 1.046(95%CI 0.919-1.19, AUC 0.53, p = 0.50)), and TiCTA 1.15(95%CI 1.02-1.30, AUC 0.60, p = 0.022). In the multivariable model, only TAI on arterial phase was significantly associated with favorable outcome (aOR 1.59, 95%CI 1.04-2.43, p = 0.032). Association between TAI with functional outcome was optimal on arterial-phase CTA such that dynamic CTA imaging has no additional benefits in current thrombus perviousness assessment, thereby suggesting that the delay of contrast arrival at the clot is a key variable for patient functional outcome. (orig.)

Successful Treatment of Free-Floating Right Ventricular Thrombus with Acute Pulmonary Embolism

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Sanjay Singhal

2015-01-01

Full Text Available Acute pulmonary embolism with floating right intra-ventricular thrombus is a rare phenomena associated with poor prognosis. Here, we are presenting a case of 35-year-young male with no co-morbid illness diagnosed to have right ventricular thrombus with bilateral pulmonary embolism, which was managed successfully with thrombolytic therapy.

Left atrial appendage thrombus with resulting stroke post-RF ablation for atrial fibrillation in a patient on dabigatran.

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Lobo, R

2015-11-01

Dabigatran etexilate is licensed for use in prevention of deep venous thromboembolism and in prevention of stroke and systemic embolism in nonvalvular atrial fibrillation (AF). It has also been used in patients for other indications as a substitute for warfarin therapy because it requires no monitoring; one group being patients undergoing radiofrequency (RF), ablation for AF, although there have been no consensus guidelines with regards to dosage and timing of dose. We report the case of a patient with documentary evidence of left atrial appendage (LAA) thrombus formation and neurological sequelae post-RF ablation despite being on dabigatran. This case highlights the concern that periprocedural dabigatran may not provide adequate protection from development of LAA thrombus and that a standardised protocol will need to be developed and undergo large multicentre trials before dabigatran can be safely used for patients undergoing RF-ablation.

An integrated fluid-chemical model toward modeling the formation of intra-luminal thrombus in abdominal aortic aneurysms.

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Biasetti, Jacopo; Spazzini, Pier Giorgio; Swedenborg, Jesper; Gasser, T Christian

2012-01-01

Abdominal Aortic Aneurysms (AAAs) are frequently characterized by the presence of an Intra-Luminal Thrombus (ILT) known to influence their evolution biochemically and biomechanically. The ILT progression mechanism is still unclear and little is known regarding the impact of the chemical species transported by blood flow on this mechanism. Chemical agonists and antagonists of platelets activation, aggregation, and adhesion and the proteins involved in the coagulation cascade (CC) may play an important role in ILT development. Starting from this assumption, the evolution of chemical species involved in the CC, their relation to coherent vortical structures (VSs) and their possible effect on ILT evolution have been studied. To this end a fluid-chemical model that simulates the CC through a series of convection-diffusion-reaction (CDR) equations has been developed. The model involves plasma-phase and surface-bound enzymes and zymogens, and includes both plasma-phase and membrane-phase reactions. Blood is modeled as a non-Newtonian incompressible fluid. VSs convect thrombin in the domain and lead to the high concentration observed in the distal portion of the AAA. This finding is in line with the clinical observations showing that the thickest ILT is usually seen in the distal AAA region. The proposed model, due to its ability to couple the fluid and chemical domains, provides an integrated mechanochemical picture that potentially could help unveil mechanisms of ILT formation and development.

Successful treatment of central venous catheter induced superior vena cava syndrome with ultrasound accelerated catheter-directed thrombolysis.

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Dumantepe, Mert; Tarhan, Arif; Ozler, Azmi

2013-06-01

Superior vena cava (SVC) syndrome results from obstruction of flow through the vessel either by external compression or thrombosis. External compression by intrathoracic neoplasms is the most common etiology, especially lung cancer and lymphoma. Thrombosis is becoming increasingly common due to the use of indwelling catheters and implantable central venous access devices. Most patients are unresponsive to anticoagulation alone which appears to be effective only in the mildest cases. However, recent advances in catheter-based interventions have led to the development of a variety of minimally invasive endovascular strategies to remove venous thrombus and accepted as an important first-line treatment given its high overall success rate and low morbidity as compared with medical and surgical treatments. Ultrasound accelerated catheter-directed thrombolysis (UACDT) has been developed to rapidly and completely resolve the existing thrombus. This technique integrates high frequency, low intensity ultrasound (US) with standard CDT in order to accelerate clot dissolution, reducing treatment time and the incidence of thrombolysis-related complications. An US wave enhances drug permeation through thrombus by disaggregating the fibrin matrix, exposing additional plasminogen receptor sites to the thrombolytic agent. The US energy affects thrombus in the entire venous segment, increasing the probability of complete thrombus clearing. We report the case of a 56-year-old man who presented with a 5 days history of SVC syndrome symptoms who had been receiving chemotherapy for colon cancer through a right subclavian vein port catheter. The patient successfully treated with UACDT with EkoSonic(®) Mach4e Endovascular device with an overnight infusion. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc.

[Clinical analysis of patients with lower extremity deep venous thrombosis complicated with inferior vena cava thrombus].

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Dong, Dian-ning; Wu, Xue-jun; Zhang, Shi-yi; Zhong, Zhen-yue; Jin, Xing

2013-06-04

To explore the clinical profiles of patients with lower extremity deep venous thrombosis (DVT) complicated with inferior vena cava (IVC) thrombus and summarize their clinical diagnostic and therapeutic experiences. The clinical characteristics, diagnosis and treatment of 20 hospitalized patients with DVT complicated with inferior vena cava thrombus were analyzed retrospectively. All of them were of proximal DVT. There were phlegmasia cerulea dolens (n = 3), pulmonary embolism (n = 3) and completely occlusion of IVC (n = 5). Clinical manifestations were severe. Retrievable inferior vena cava filter (IVCF) was implanted for 17 cases. Catheter-directed thrombolysis (CDT) through ipsilateral popliteal vein was applied for 7 cases and systemic thrombolysis therapy for 8 cases. The effective rate of thrombolysis for fresh IVC thrombus was 100%. Among 5 cases with Cockett Syndrome, 3 cases underwent balloon dilatation angioplasty and endovascular stenting of iliac vein. And 17 IVCFs were retrieved successfully within 3 weeks. IVC thrombus disappeared completely in 15 cases. Systemic or local thrombolysis with protective IVCF is a safe and effective therapy for nonocclusive IVC thrombus in DVT. And CDT is recommended for symptomatic occlusive IVC thrombus.

Quantity of residual thrombus after successful catheter-directed thrombolysis for iliofemoral deep venous thrombosis correlates with recurrence.

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Aziz, F; Comerota, A J

2012-08-01

Iliofemoral deep venous thrombosis (IFDVT) is an independent risk factor for recurrent DVT. It has been observed that recurrent DVT correlates with residual thrombus. This study evaluates whether risk of recurrence is related to the amount of residual thrombus following catheter-directed thrombolysis (CDT) for IFDVT. Patients who underwent CDT for IFDVT had their degree of lysis quantified by a reader blind to the patients' long-term clinical outcome. Patients were classified into two groups, ≥50% and thrombus. Recurrence was defined as a symptomatic presentation with image verification of new or additional thrombus. A total of 75 patients underwent CDT for IFDVT. Median follow-up was 35.9 months. Sixty-eight patients (91%) had no evidence of recurrence and seven (9%) developed recurrence. Of the patients who had ≥50% (mean 80%) residual thrombus, 50% (4/8) experienced recurrence, but in those with thrombus, only 5% (3/67) had recurrent DVT (P = 0.0014). The burden of residual thrombus at completion of CDT correlates with the risk of DVT recurrence. Patients having CDT for IFDVT had a lower risk of recurrence than expected. Successful clearing of acute clot in IFDVT patients significantly reduces the recurrence risk compared to patients with a large residual thrombus burden. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

[Molecular imaging of thrombus with microbubbles targeted to alphavbeta3-integrin using an agarose flow chamber model].

Science.gov (United States)

Hu, Guang-quan; Liu, Jian; Yang, Li; Yan, Yi; Wu, Jue-fei; Xie, Jia-jia; Cai, Jing-jing; Ji, Li-jing; Bin, Jian-ping

2010-03-01

To assess the binding ability of microbubbles targeted to alphavbeta3-integrin (MBp) for thrombus-targeted contrast-enhanced ultrasound. Targeted microbubbles were prepared by conjugating the monoclonal antibody against alphavbeta3-integrin to lipid shell of the microbubble via the avidin-biotin bridges. Equivalent isotype control microbubbles (MB) or targeted ultrasound microbubbles (MBp) were randomly added into the flow chamber. After a 30-min incubation with the thrombus fixed in an agarose flow chamber model, the thrombus was washed with a continuous flow of PBS solution (15 cm/s) for 2, 4, 6, 8 and 10 min, followed by thrombus imaging using contrast-enhanced ultrasound and measurement of the video intensity (VI) values of the images. The VI of the thrombus in MBp group was reduced by 28%-66%, while that in control MB group was decreased by 87%-94%, and the VI values of the thrombus group were significantly greater in former group at each of the time points (Pevaluation of the thrombus-binding capability of the targeted microbubble (MBp) by simulating the shear stress in vivo can be helpful for predicting the in vivo effects of ultrasonic molecular imaging using MBp.

Slow flow and mural thrombus in aortic diseases: Spin-echo MR findings and their differentiation

International Nuclear Information System (INIS)

Chung, Jin Wook; Park, Jae Hyung; Han, Man Chung

1993-01-01

In order to evaluate the ability of spin-echo MR imaging to differentiate slow flow from mural thrombus in aortic diseases, we reviewed the spin-echo MR images of 13 patients with intraaortic thrombus documented by CT (N=11) or aortography (N=2). Six patients had aortic aneurysms and seven had aortic dissections. Intraaortic mural thrombi were accompanied by flow-related intraluminal signal of various pattern and extents in all 13 patients. On 10 gated MR studies, slow flow regions showed ever-echo rephasing phenomenon (N=8), interslice variation of signal intensities of the intraluminal signal (N=7) and flow-related ghost artifact (N=2). However, these MR flow phenomena were obscured on two of three non-gated studies. Seven of 13 intraaortic thrombi remained hyperintense on T2-weighted second-echo images. In these circumstance, a hypointense boundary layer between slow flow and mural thrombus, which was caused by either ' boundary layer dephasing phenomenon' of slow flow or 'paramagnetic T2 shortening' of fresh clot at the edge of mural thrombus, was very useful in discriminating the area of slow flow from that of mural thrombus. Proper interpretation of spin-echo MR images may obviate the need for phase display imaging or gradient-echo imaging in differentiating slow flow and mural thrombus

Radiodiagnostic methods in determining the structure of tumor thrombus in the inferior vena cava in kidney cancer

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N. B. Vikhrova

2015-01-01

Full Text Available Renal cell carcinoma (RCC is the most common primary tumor of the renal parenchyma. Venous involvement is one of the most important anatomic characteristics of tumor. It is known that venous spread influences the survival of patients with RCC. Tumor thrombosis of IVC in patients with renal cell carcinoma has been reported in 4–10 %. The reference standard for RCC with tumor thrombus remains surgical resection. The structure of thrombus determines some technical difficulties in the management of tumor. Spongeous thrombus correlate with higher risk of thrombus detachment during surgery resulting in PE. Therefore determination of IVC thrombus consistency is very important part of preoperative radiologic assessment of tumor in patients with RCC.

Right Ventricular Endomyocardial Fibrosis Presenting With Ventricular Tachycardia And Apical Thrombus - An Interesting Presentation

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Amitesh Aggarwal

2009-11-01

Full Text Available Endomyocardial fibrosis is a progressive disease of unknown origin affecting children and young adults. It involves inflow portion of right and/or left ventricle and apex. It may be associated with thrombus. Literature regarding right ventricular endomyocardial fibrosis with thrombus is scarce. Here we report a rare case of right ventricular endomyocardial fibrosis presenting as ventricular tachycardia and echocardiographic evidence of apical thrombus. Interestingly there was no pulmonary involvement or evidence of deep venous thrombosis. This case also underscores the importance of urgent echocardiography in diagnosis of obscure cases of ventricular tachycardia.

A Therapeutic Challenge: Management of Atrial Thrombus

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Serkan Burc Deser

2016-09-01

Full Text Available Introduction: Primary cause of atrial thrombi include atrial fibrillation, foreign bodies inside the atrium such as catheters and pacemaker leads, emboli of deep venous thrombus and primary or metastatic tumors of the heart. We review the clinical features, epidemiology, diagnosis and treatment of nine intriguing cases with atrial thrombus. Methods: This is a retrospective study of nine patients (seven female (78%, two male (33% who were diagnosed with atrial thrombi (average age of 50 ± 12 years and were treated at the Ondokuz Mayis University, Department of Cardiovascular Surgery from February 2014 to January 2015. Among them, six patients had atrial fibrillation (one male, five female, seven patients were suffering from dispne and orthopnoea, five patients were suffering from leg swelling, seven patients had a history of hypertension and three patients had a history of mitral valve replacement surgery. Results: All patients underwent surgery except one. Four patients recovered uneventfully and discharged with oral anticoagulation (warfarin therapy (adjusted to maintain an international normalized ratio of INR between two and three times. Five of nine patients (55% died after surgery. Conclusion: The response to the thrombolytic therapy is poor, mostly ineffective and unsafe so it is often recommended as a bridge to surgery. In patients diagnosed with mechanical mitral valve thrombosis, medical therapy has the possibility of end organ emboli and also fail to resolve the organised thrombus on the stuck valve. On the other hand surgery does not always give satisfactory results. J Clin Exp Invest 2016; 7(4: 278-282

Therapeutic effect and prognostic analysis of intensity-modulated radiotherapy for primary hepatocellular carcinoma with portal vein and/or inferior vena cava tumor thrombus

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HUANG Long

2015-06-01

Full Text Available ObjectiveTo determine the efficacy and prognostic factors of intensity-modulated radiotherapy (IMRT for primary hepatocellular carcinoma (HCC with portal vein and/or inferior vena cava tumor thrombus. MethodsTwenty-three HCC patients with portal vein and/or inferior vena cava tumor thrombus received IMRT with an 8 MV linear accelerator at the Cancer Center of General Hospital of Armed Police Forces, Anhui Medical University, from April 2008 to August 2011. A single dose of 3 to 6 Gy was delivered at five fractions per week, with a total dose of 56 to 96 Gy and a median dose of 60 Gy. Survival time was recorded, and adverse reactions were evaluated. Survival rate calculation and survival analysis were performed using the Kaplan-Meier method. Comparison of categorical between two groups was made by chi-square test. ResultsOne patient did not complete radiotherapy due to upper gastrointestinal bleeding. Of 22 patients who completed IMRT, 4 achieved complete remission and 10 achieved partial remission, with an overall response rate of 63.7%. Our analysis showed that the type of tumor thrombus and tumor size were associated with tumor response rate and were significant prognostic factors (P＜0.05. The median survival time was 13.4 months. The 1-, 2-, and 3-year survival rates were 59%, 27%, and 18%, respectively. The 22 patients who completed radiotherapy did not experience acute radiation injury or late adverse outcomes such as radiation-induced liver disease. ConclusionThis study suggests IMRT is a safe and effective treatment option for HCC patients with portal vein and/or inferior vena cava tumor thrombus.

CT diagnosis of tumor thrombus of the renal vein and inferior vena cava

International Nuclear Information System (INIS)

Masuda, Fujio; Chen, Zuicho; Oishi, Yukihiko; Machida, Toyohei

1980-01-01

We used computed tomography (CT) for diagnosis in 4 cases of renal tumor associated with tumor thrombus of the renal vein and inferior vana cava. The results obtained are described below: A total of 4 cases consisting of 3 cases of renal cell carcinoma and one case of squamous cell carcinoma of the renal pelvis, treated at the Jikei University Hospital during the six months period from January to June of 1979, were studied. The affected side was right in 3 cases and left in one case. In all of the former cases the tumor thrombus was extending from the renal vein to the inferior vena cava, while in the latter case it was confined in the renal vein. All these 4 cases received CT together with renal arteriography and inferior venacavography, followed by nephrectomy, and were confirmed of the presence of tumor thrombus in the renal vein and inferior vena cava operatively. CT findings revealed a pronounced enlargement of the renal vein, and tumor thrombus of the renal vein was diagnosed in all of the 4 cases. In 2 of 3 cases in which tumor thrombus extended to the inferior vena cava, the dilated renal vein was found to be connected to the slightly dilated inferior vena cava, while in the remaining one case the outline of the inferior vena cava was obscure, showing no clear dilatation. After contrast enhancement, a filling defect was seen in the inferior vena cava. CT findings of tumor thrombus in the vein indicated a dilatation of the renal vein and inferior vena cava. In addition, a filling defect was found after contrast enhancement, suggesting that CT is helpful as a diagnostic aid. (author)

[Stroke due to infective endocarditis diagnosed by the retrieved thrombus: a case report].

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Nakanishi, Kaoru; Kawano, Hiroyuki; Amano, Tatsuo; Omori, Yoshihiko; Kanma, Hiroshi; Hirano, Teruyuki

2018-01-26

A 80-years-old woman suddenly presented with aphasia, right hemiparesis, and dysesthesia. MRA showed the left middle cerebral artery occlusion. She was diagnosed as hyperacute ischemic stroke. She was treated with intravenous recombinant tissue plasminogen activator and underwent endovascular thrombectomy. On admission, she had a fever and high C reactive protein, and was treated with antibiotic therapy. The pathological diagnosis of the retrieved thrombus revealed the cluster of the gram positive cocci. The blood culture was negative and thransthoracic echocardiogram did not detect the vegetation. She was finally diagnosed as cardioembolic stroke due to infective endocarditis based on the pathological diagnosis of the retrieved thrombus. The pathological diagnosis of the retrieved thrombus was quite important to clarify the cause of ischemic stroke.

Assessment of thrombus imaging potency of thrombin-targeting recombinant hirudin in vitro and in vivo

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Cheng, Tan; Rongjun, Zhang; Weixing, Wan; Gangming, Cai; Huixin, Yu; Mengjun, Jiang; Lianfen, Zhang; Guoping, Sheng; Yijun, Fan; Yonghui, Tao; Jian, Jin [Jiangsu Inst. of Nuclear Medicine, Wuxi (China)

2003-07-01

The purpose of this study is to evaluate the effect of recombinant hirudin HV2 (rHHV2) as a thrombus imaging agent. {sup 125}I-rHHV2 and {sup 125}I-Th were prepared with Chloramine method, the labeling rate were 86.64% and 62.20%, with the radioactive purity of 89.70% and 91.22%, with the specific activity of 22.4 TBq/mmol and 94.43 TBq/mmol respectively. The competitive radioassay showed that the Th-fibrin complex formation did not affect the ability of rHHV2 binding with Th. In the complex, the molecular binding ratio of rHHV2 to Th and fibrinogen was 14:14:1. {sup 99m}Tc-rHHV2 was prepared by 2-iminothiolane modified method, the labeled rate was 94%, with the radioactive purity of 93.90%, with the specific activity of 2.30 TBq/mmol. It was used to image fresh thrombi on arteries and veins of dog or rabbit (30 {mu}g/kg). In SPECT images, all thrombin were clearly visible, arterial thrombosis imaging can be seen clearly within 45 min after injection and fade away slowly, venous thrombosis imaging also can be seen within 30 min after injection and quantitative imaging ratios between the thrombus and opposite vessel increased following the time. Biodistribution studies in mouse demonstrated that rHHV2 was excreted from kidneys. These data indicate that Th in Th-fibrin complex could be a potent target for diagnosis of thrombus and {sup 99m}Tc-rHHV2 could be a new thrombotic imaging agent. (authors)

Systematic Review of Treatment for Trapped Thrombus in Patent Foramen Ovale.

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Seo, Won-Woo; Kim, Sung Eun; Park, Myung-Soo; Lee, Jun-Hee; Park, Dae-Gyun; Han, Kyoo-Rok; Oh, Dong-Jin

2017-09-01

Trapped thrombus in patent foramen ovale (PFO) is a rare complication of pulmonary embolism that may lead to tragic clinical events. The aim of this study was to identify the optimal treatment for different clinical situations in patients with trapped thrombus in a PFO by conducting a literature review. A PubMed database search was conducted from 1991 through 2015, and 194 patients (185 articles) with trapped thrombus in a PFO were identified. Patient characteristics, paradoxical embolic events, and factors affecting 60-day mortality were analyzed retrospectively. Among all patients, 112 (57.7%) were treated with surgery, 28 with thrombolysis, and 54 with anticoagulation alone. Dyspnea (79.4%), chest pain (33.0%), and syncope (17.5%) were the most common presenting symptoms. Pretreatment embolism was found in 37.6% of cases, and stroke (24.7%) was the most common event. Surgery was associated with fewer post-treatment embolic events than were other treatment options (p=0.044). In the multivariate analysis, initial shock or arrest, and thrombolysis were independent predictors of 60-day mortality. Thrombolysis was related with higher 60-day mortality compared with surgery in patients who had no initial shock or arrest. This systematic review showed that surgery was associated with a lower overall incidence of post-treatment embolic events and a lower 60-day mortality in patients with trapped thrombus in a PFO. In patients without initial shock or arrest, thrombolysis was related with a higher 60-day mortality compared with surgery.

GIANT PROSTHETIC VALVE THROMBUS

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Prashanth Kumar

2015-04-01

Full Text Available Mechanical prosthetic valves are predisposed to bleeding, thrombosis & thromboembolic complications. Overall incidence of thromboembolic complications is 1% per year who are on oral anticoagulants, whereas bleeding complications incidence is 0.5% to 6.6% per year. 1, 2 Minimization of Scylla of thromboembolic & Charybdis of bleeding complication needs a balancing act of optimal antithrombotic therapy. We are reporting a case of middle aged male patient with prosthetic mitral valve presenting in heart failure. Patient had discontinued anticoagulants, as he had subdural hematoma in the past. He presented to our institute with a giant prosthetic valve thrombus.

Identification of intraluminal thrombus by ultrasonography in emergency department patients with acute deep venous thrombosis.

Science.gov (United States)

Mehta, Ninfa; Schecter, Joshua; Stone, Michael

2012-05-01

Traditionally, the diagnosis of deep venous thrombosis (DVT) using duplex ultrasonography (DU) has relied on the absence of venous compressibility. Visualization of an intraluminal thrombus is considered an uncommon finding. The purpose of this study is to determine the frequency of intraluminal thrombus in emergency department (ED) patients diagnosed with acute DVT. Retrospective chart review of adult ED patients with DU examinations demonstrating acute DVT. Patients with chronic DVT or patients in whom DU did not demonstrate DVT were excluded from data analysis. Study reports and ultrasound images were reviewed and analyzed for the presence of intraluminal thrombus. There were 189 patients who met inclusion criteria, of which 160 (85%) were found to have intraluminal thrombus. Intraluminal thrombi are present in the majority of patients in our ED in whom acute DVT is identified by DU. Copyright © 2012 Elsevier Inc. All rights reserved.

Correlation of Acute M1 Middle Cerebral Artery Thrombus Location with Endovascular Treatment Success and Clinical Outcome.

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Pavabvash, Seyedmehdi; Taleb, Shayandokht; Majidi, Shahram; Qureshi, Adnan I

2017-01-01

The location of the arterial occlusion can help with prognostication and treatment triage of acute stroke patients. We aimed to determine the effects of M1 distance-to-thrombus on angiographic recanalization success rate and clinical outcome following endovascular treatment of acute M1 occlusion. All acute ischemic stroke patients with M1 segment middle cerebral artery (MCA) occlusion on admission CT angiography (CTA) who underwent endovascular treatment were analyzed. The distance between thrombus origin and internal carotid artery (ICA) bifurcation was measured on admission CTA. The modified thrombolysis in cerebral infarction (mTICI) grades 2 b (>50% of distal branch filling) and 3 (complete) were considered as successful recanalization. Favorable outcome was defined by 3-month follow-up modified Rankin scale (mRs) score ≤2. Successful recanalization was achieved in 24 (71%) of 34 consecutive patients included in this study. The M1 distance-to-thrombus was shorter among patients with successful recanalization (5.4 ± 5.4 mm) versus those without (11.3 ± 7.6 mm, p = 0.015). The successful recanalization rate was higher among patients with M1 distance-to-thrombus ≤6 mm (odds ratio: 8, 95% confidence interval: 1.37-46.81, p = 0.023) compared with those with distance-to-thrombus >6 mm. There was no significant correlation between M1 distance-to-thrombus and 3-month mRs (rho: 0.131, p = 0.461); however, the distance-to-thrombus negatively correlated with admission National Institutes of Health Stroke Scale (NIHSS) scores (rho: -0.350, p=0.043). On the other hand, successful recanalization and admission NIHSS score were the only independent predictors of favorable outcome. Shorter distance of M1 thrombus from ICA bifurcation is associated with higher rate of successful recanalization following endovascular treatment.

Correlation of Acute M1 Middle Cerebral Artery Thrombus Location with Endovascular Treatment Success and Clinical Outcome

Science.gov (United States)

Pavabvash, Seyedmehdi; Taleb, Shayandokht; Majidi, Shahram; Qureshi, Adnan I.

2017-01-01

Purpose The location of the arterial occlusion can help with prognostication and treatment triage of acute stroke patients. We aimed to determine the effects of M1 distance-to-thrombus on angiographic recanalization success rate and clinical outcome following endovascular treatment of acute M1 occlusion. Methods All acute ischemic stroke patients with M1 segment middle cerebral artery (MCA) occlusion on admission CT angiography (CTA) who underwent endovascular treatment were analyzed. The distance between thrombus origin and internal carotid artery (ICA) bifurcation was measured on admission CTA. The modified thrombolysis in cerebral infarction (mTICI) grades 2b (>50% of distal branch filling) and 3 (complete) were considered as successful recanalization. Favorable outcome was defined by 3-month follow-up modified Rankin scale (mRs) score ≤2. Results Successful recanalization was achieved in 24 (71%) of 34 consecutive patients included in this study. The M1 distance-to-thrombus was shorter among patients with successful recanalization (5.4 ± 5.4 mm) versus those without (11.3 ± 7.6 mm, p = 0.015). The successful recanalization rate was higher among patients with M1 distance-to-thrombus ≤6 mm (odds ratio: 8, 95% confidence interval: 1.37–46.81, p = 0.023) compared with those with distance-to-thrombus >6 mm. There was no significant correlation between M1 distance-to-thrombus and 3-month mRs (rho: 0.131, p = 0.461); however, the distance-to-thrombus negatively correlated with admission National Institutes of Health Stroke Scale (NIHSS) scores (rho: −0.350, p=0.043). On the other hand, successful recanalization and admission NIHSS score were the only independent predictors of favorable outcome. Conclusion Shorter distance of M1 thrombus from ICA bifurcation is associated with higher rate of successful recanalization following endovascular treatment. PMID:28243346

Resectable hepatoblastoma with tumor thrombus extending into the right atrium after chemotherapy: A case report

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Kosuke Endo

2016-04-01

Full Text Available Hepatoblastoma with intraatrial tumor thrombus is relatively rare. We report a case of hepatoblastoma with tumor thrombus extending into the right atrium, which responded well to chemotherapy and was resected using extracorporeal circulation. A 4-year-old girl was referred to our hospital because of abdominal distention and tenderness. A computed tomography (CT scan showed a large tumor occupying the left 3 segments of the liver with tumor thrombus extending into the right atrium. There was also a small intrahepatic metastasis in the right lobe of the liver. She was diagnosed with hepatoblastoma on the basis of the results of open biopsy. Neoadjuvant chemotherapy with an intense CDDP-based regimen was performed. The tumor responded well to chemotherapy, and intrahepatic metastasis became undetectable on CT scan, although the tumor thrombus remained in the right atrium. After 7 courses of chemotherapy, we performed resection using extracorporeal circulation. The postoperative course was uneventful, and adjuvant chemotherapy was started 10 days after the operation. Her serum alpha-fetoprotein (AFP level decreased to the normal range, and she was free of disease for 1 year after the operation. Tumor resection using extracorporeal circulation can be performed safely and is justified in patients with intraatrial tumor thrombus.

Bacterial signatures in thrombus aspirates of patients with lower limb arterial and venous thrombosis.

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Vakhitov, Damir; Tuomisto, Sari; Martiskainen, Mika; Korhonen, Janne; Pessi, Tanja; Salenius, Juha-Pekka; Suominen, Velipekka; Lehtimäki, Terho; Karhunen, Pekka J; Oksala, Niku

2018-06-01

Increasing data supports the role of bacterial inflammation in adverse events of cardiovascular and cerebrovascular diseases. In our previous research, DNA of bacterial species found in coronary artery thrombus aspirates and ruptured cerebral aneurysms were mostly of endodontic and periodontal origin, where Streptococcus mitis group DNA was the most common. We hypothesized that the genomes of S mitis group could be identified in thrombus aspirates of patients with lower limb arterial and deep venous thrombosis. Thrombus aspirates and control blood samples taken from 42 patients with acute or acute-on-chronic lower limb ischemia (Rutherford I-IIb) owing to arterial or graft thrombosis (n = 31) or lower limb deep venous thrombosis (n = 11) were examined using a quantitative real-time polymerase chain reaction to detect all possible bacterial DNA and DNA of S mitis group in particular. The samples were considered positive, if the amount of bacterial DNA in the thrombus aspirates was 2-fold or greater in comparison with control blood samples. In the positive samples the mean difference for the total bacterial DNA was 12.1-fold (median, 7.1), whereas the differences for S mitis group DNA were a mean of 29.1 and a median of 5.2-fold. Of the arterial thrombus aspirates, 57.9% were positive for bacterial DNA, whereas bacterial genomes were found in 75% of bypass graft thrombosis with 77.8% of the prosthetic grafts being positive. Of the deep vein thrombus aspirates, 45.5% contained bacterial genomes. Most (80%) of bacterial DNA-positive cases contained DNA from the S mitis group. Previous arterial interventions were significantly associated with the occurrence of S mitis group DNA (P = .049, Fisher's exact test). This is the first study to report the presence of bacterial DNA, predominantly of S mitis group origin, in the thrombus aspirates of surgical patients with lower limb arterial and deep venous thrombosis, suggesting their possible role in the pathogenesis of

Vortex Formation and Acceleration of a Fish-Inspired Robot Performing Starts from Rest

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Devoria, Adam; Bapst, Jonathan; Ringuette, Matthew

2009-11-01

We investigate the unsteady flow of a fish-inspired robot executing starts from rest, with the objective of understanding the connection among the kinematics, vortex formation, and acceleration performance. Several fish perform ``fast starts,'' where the body bends into a ``C'' or ``S'' shape while turning (phase I), followed by a straightening of the body and caudal fin and a linear acceleration (phase II). The resulting highly 3-D, unsteady vortex formation and its relationship to the acceleration are not well understood. The self-propelled robotic model contains motor-driven joints with programmable motion to emulate phase II of a simplified C-start. The experiments are conducted in a water tank, and the model is constrained to 1 direction along rails. The velocity is measured using digital particle image velocimetry (DPIV) in multiple planes. Vortex boundaries are identified using the finite-time Lyapunov exponent, then the unsteady vortex circulation is computed. The thrust is estimated from the identified vortices, and correlated with the circulation and model acceleration for different kinematics.

Comparison of the Effectiveness of Three Methods of Recanalization in a Model of the Middle Cerebral Artery: Thrombus Aspiration via a 4F Catheter, Thrombus Aspiration via the GP Thromboaspiration Device, and Mechanical Thrombectomy Using the Solitaire Thrombectomy Device

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Christopher Tennuci

2011-01-01

Full Text Available Introduction. This paper compares different approaches to recanalization in a model of the middle cerebral artery (MCA. Methods. An occlusive thrombus (lamb's blood was introduced into the MCA of a model of the cerebral circulation perfused with Hartmann's solution (80 pulsations/min, mean pressure 90 mm Hg. Three methods of clot retrieval were tested: thrombus aspiration via a 4F catheter (n=26, thrombus aspiration via the GP thrombus aspiration device (GPTAD (n=30, and mechanical thrombectomy via the Solitaire Device (n=30. Results. Recanalization rate was similar for all 3 approaches (62%, 77%, and 85%. Time to recanalization was faster with aspiration devices (41 SD 42 s for 4F and 61 SD 21 s for GPTAD than with the Solitaire (197 SD 64 s P<.05 Kruksal-Wallis. Clot fragmentation was the same in the Solitaire (23% and the GPTAD (23%, but higher with the 4F (53%, P<.05. Conclusion. In this model, thrombus aspiration was faster than mechanical thrombectomy, and similarly effective at recanalization. These results should be confirmed in vivo.

Artificial aortic valve dysfunction due to pannus and thrombus - different methods of cardiac surgical management.

Science.gov (United States)

Ostrowski, Stanisław; Marcinkiewicz, Anna; Kośmider, Anna; Walczak, Andrzej; Zwoliński, Radosław; Jaszewski, Ryszard

2015-09-01

Approximately 60 000 prosthetic valves are implanted annually in the USA. The risk of prosthesis dysfunction ranges from 0.1% to 4% per year. Prosthesis valve dysfunction is usually caused by a thrombus obstructing the prosthetic discs. However, 10% of prosthetic valves are dysfunctional due to pannus formation, and 12% of prostheses are damaged by both fibrinous and thrombotic components. The authors present two patients with dysfunctional aortic prostheses who were referred for cardiac surgery. Different surgical solutions were used in the treatment of each case. The first patient was a 71-year-old woman whose medical history included arterial hypertension, stable coronary artery disease, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and hypercholesterolemia; she had previously undergone left-sided mastectomy and radiotherapy. The patient was admitted to the Cardiac Surgery Department due to aortic prosthesis dysfunction. Transthoracic echocardiography revealed complete obstruction of one disc and a severe reduction in the mobility of the second. The mean transvalvular gradient was very high. During the operation, pannus covering the discs' surface was found. A biological aortic prosthesis was reimplanted without complications. The second patient was an 87-year-old woman with arterial hypertension, persistent atrial fibrillation, and COPD, whose past medical history included gastric ulcer disease and ischemic stroke. As in the case of the first patient, she was admitted due to valvular prosthesis dysfunction. Preoperative transthoracic echocardiography revealed an obstruction of the posterior prosthetic disc and significant aortic regurgitation. Transesophageal echocardiography and fluoroscopy confirmed the prosthetic dysfunction. During the operation, a thrombus growing around a minor pannus was found. The thrombus and pannus were removed, and normal functionality of the prosthetic valve was restored. Precise and modern diagnostic methods

Collisionless shock formation and the prompt acceleration of solar flare ions

Science.gov (United States)

Cargill, P. J.; Goodrich, C. C.; Vlahos, L.

1988-01-01

The formation mechanisms of collisionless shocks in solar flare plasmas are investigated. The priamry flare energy release is assumed to arise in the coronal portion of a flare loop as many small regions or 'hot spots' where the plasma beta locally exceeds unity. One dimensional hybrid numerical simulations show that the expansion of these 'hot spots' in a direction either perpendicular or oblique to the ambient magnetic field gives rise to collisionless shocks in a few Omega(i), where Omega(i) is the local ion cyclotron frequency. For solar parameters, this is less than 1 second. The local shocks are then subsequently able to accelerate particles to 10 MeV in less than 1 second by a combined drift-diffusive process. The formation mechanism may also give rise to energetic ions of 100 keV in the shock vicinity. The presence of these energetic ions is due either to ion heating or ion beam instabilities and they may act as a seed population for further acceleration. The prompt acceleration of ions inferred from the Gamma Ray Spectrometer on the Solar Maximum Mission can thus be explained by this mechanism.

Variable effects of radiological contrast media on thrombus growth in a rabbit jugular vein thrombosis model

NARCIS (Netherlands)

Levi, M. [=Marcel M.; Biemond, B. J.; Sturk, A.; Hoek, J.; ten Cate, J. W.

1991-01-01

We studied the effect of an ionic high osmolar contrast medium (Ioxitalamate), an ionic low osmolar contrast medium (Ioxaglate) and various nonionic low osmolar contrast media (Iopamidol, Iopromide and Iohexol) on thrombus growth in a rabbit jugular vein thrombosis model. Thrombus growth was

Incidência de trombo intracardíaco e de tromboembolismo nos três primeiros meses após o implante de bioprótese valvar Incidence of intracardiac thrombus and thromboembolism in the first three months after bioprosthetic valve implantation

Directory of Open Access Journals (Sweden)

Auristela Isabel de Oliveira Ramos

2004-12-01

Full Text Available OBJETIVO: Avaliar a incidência de trombo intracardíaco e de tromboembolismo nos três primeiros meses após a troca valvar por bioprótese e identificar fatores de risco para a formação de trombo. MÉTODO:Incluídos 184 pacientes, entre 15 e 75 anos de idade, submetidos a implante de bioprótese e realizados ecocardiogramas transtorácico e transesofágico (ETE na fase hospitalar, média 8,4±3 dias, e três meses após, média 97,4±21,7 dias. RESULTADOS: Incidência de trombo foi significativamente mais elevada nos pacientes com prótese em posição mitral ou mitroaórtica (21,0% do que em posição aórtica (2,8%, pOBJECTIVE: To assess the incidence of intracardiac thrombus and thromboembolism in the first 3 months after bioprosthetic valve replacement and to identify the risk factors for thrombus formation. METHODS: The study comprised 184 patients, aged between 15 and 75 years, who underwent bioprosthetic valve implantation. Transthoracic and transesophageal (TEE echocardiographies were performed in the in-hospital phase (mean, 8.4±3 days and after 3 months (mean, 97.4±21.7 days. RESULTS: The incidence of thrombus was significantly greater in patients with a prosthesis in the mitral or mitroaortic position (21.0% than in those with a prosthesis in the aortic position (2.8%, P<0.001. The multiple logistic regression identified the prosthesis in the mitral or mitroaortic position as the only independent variable for thrombus formation. On the 3-month follow-up, TEE showed a thrombus in 35 (20.7% of the 169 patients on echocardiographic assessment, 31.7% in mitral patients and 3.1% in aortic patients, P<0.001. In the third month, the multiple logistic regression also identified the prosthesis in the mitral or mitroaortic position as the only independent variable for thrombus formation. During the 3-month follow-up, 3 (1.6% patients died and 8 (4.3% experienced embolic phenomena, all in the cerebral territory. CONCLUSION: The incidence

Fluoroscopy-Guided Resolution of Ingested Thrombus Leading to Functional Disturbance of a Continuous-Flow Left Ventricular Assist Device

Directory of Open Access Journals (Sweden)

Jens Garbade

2012-01-01

Full Text Available The third generation of left ventricular assist devices (LVADs has been shown to improve outcome and quality of life in patients suffering from acute and chronic heart failure. However, VAD-associated complications are still a challenge in the clinical practice. Here we report the resolution of a mobile thrombus formation in the proximity of the inflow cannula of a third generation of LVADs (HVAD Pump, HeartWare, Inc. in a patient with chronic heart failure 4 months after implantation.

Development of Thrombus in a Systemic Vein after Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varices

International Nuclear Information System (INIS)

Yoshimatsu, Rika; Yamagami, Takuji; Tanaka, Osamu; Miura, Hiroshi; Nishimura, Tsunehiko; Okuda, Kotaro; Hashiba, Mitsuoki

2012-01-01

To retrospectively evaluate the frequency and risk factors for developing thrombus in a systemic vein such as the infrarenal inferior vena cava or the iliac vein, in which a balloon-occluded retrograde transvenous obliteration (B-RTO) catheter was indwelled. Forty-nine patients who underwent B-RTO for gastric varices were included in this study. The B-RTO procedure was performed from the right femoral vein, and the B-RTO catheter was retained overnight in all patients. Pre- and post-procedural CT scans were retrospectively compared in order to evaluate the development of thrombus in the systemic vein in which the catheter was indwelled. Additionally, several variables were analyzed to assess risk factors for thrombus in a systemic vein. In all 49 patients (100%), B-RTO was technically successful, and in 46 patients (94%), complete thrombosis of the gastric varices was achieved. In 6 patients (12%), thrombus developed in the infrarenal inferior vena cava or the right common-external iliac vein. All thrombi lay longitudinally on the right side of the inferior vena cava or the right iliac vein. One of the aforementioned 6 patients required anticoagulation therapy. No symptoms suggestive of pulmonary embolism were observed. Prothrombin time-international normalized ratio and the addition of 5% ethanolamine oleate iopamidol, on the second day, were related to the development of thrombus. Development of a thrombus in a systemic vein such as the inferior vena cava or iliac vein, caused by indwelling of the B-RTO catheter, is relatively frequent. Physicians should be aware of the possibility of pulmonary embolism due to iliocaval thrombosis.

Placement and retrieval of a Guenther tulip filter in patients with a free floating thrombus in inferior vena cava

International Nuclear Information System (INIS)

Seong, Min Hyun; Kim, Young Hwan; Lee, Sang Kwon; Choi, Jin Soo; Kim, Mi Jeong; Koo, Ja Hyun; Kim, Hyoung Tae; Cho, Won Hyun; Seong, Nak Kwan

2005-01-01

We wanted to assess the technical feasibility and clinical efficacy of the placement and retrieval of a Guenther Tulip filter for the prevention of fatal pulmonary embolism during the management of patients with a free floating thrombus in their inferior vena ca va (IVC). Six patients having a free floating thrombus in their IVC (three patients with an isolated free floating thrombus in the IVC that resulted from immobilization due to traumatic liver injury or cerebral infarction, two patients with coexisting deep vein thrombosis in the left lower extremity that was caused by May-Thurner syndrome, and one patient with coexisting deep vein thrombosis in the right lower extremity that was due to nephrotic syndrome and immobilization after hip joint replacement) underwent placement and retrieval of a Guenther Tulip filter. The placement of the filter was performed through the right internal jugular vein to prevent the risk of detachment of the thrombus during the procedure. Retrieval of filter was performed after the free floating thrombus of the IVC had disappeared on follow-up CT because of anticoagulation therapy, aspiration thrombectomy or catheter directed Urokinase thrombolysis. The Guenther Tulip filter was successfully placed in the IVC in all six patients and it was retrieved after the management of the free floating thrombus. The mean duration of the placement of the filter was 11 days (range:7-25 days). Two patients underwent placement of an iliac vein stent for the management of May-Thurner syndrome. Detachment of the free floating thrombus in the IVC and the subsequent thrombus entrapment in the filter were documented during aspiration thrombectomy or Urokinase thrombolysis in four patients. Recurrent thrombus didn't occur during the follow-up period (range:3-20 months) in five of the six patients. In one patient, a recurrent thrombus due to the discontinuance of anticoagulation therapy was identified at the filter detachment site of the IVC on the follow

Erythrocyte membrane modified janus polymeric motors for thrombus therapy

NARCIS (Netherlands)

Shao, Jingxin; Abdelghani, Mona; Shen, Guizhi; Cao, Shoupeng; Williams, David S.; van Hest, Jan C.M.

2018-01-01

We report the construction of erythrocyte membrane-cloaked Janus polymeric motors (EM-JPMs) which are propelled by near-infrared (NIR) laser irradiation and are successfully applied in thrombus ablation. Chitosan (a natural polysaccharide with positive charge, CHI) and heparin (glycosaminoglycan

Innate Effector-Memory T-Cell Activation Regulates Post-Thrombotic Vein Wall Inflammation and Thrombus Resolution.

Science.gov (United States)

Luther, Natascha; Shahneh, Fatemeh; Brähler, Melanie; Krebs, Franziska; Jäckel, Sven; Subramaniam, Saravanan; Stanger, Christian; Schönfelder, Tanja; Kleis-Fischer, Bettina; Reinhardt, Christoph; Probst, Hans Christian; Wenzel, Philip; Schäfer, Katrin; Becker, Christian

2016-12-09

Immune cells play an important role during the generation and resolution of thrombosis. T cells are powerful regulators of immune and nonimmune cell function, however, their role in sterile inflammation in venous thrombosis has not been systematically examined. This study investigated the recruitment, activation, and inflammatory activity of T cells in deep vein thrombosis and its consequences for venous thrombus resolution. CD4 + and CD8 + T cells infiltrate the thrombus and vein wall rapidly on deep vein thrombosis induction and remain in the tissue throughout the thrombus resolution. In the vein wall, recruited T cells largely consist of effector-memory T (T EM ) cells. Using T-cell receptor transgenic reporter mice, we demonstrate that deep vein thrombosis-recruited T EM receive an immediate antigen-independent activation and produce IFN-γ (interferon) in situ. Mapping inflammatory conditions in the thrombotic vein, we identify a set of deep vein thrombosis upregulated cytokines and chemokines that synergize to induce antigen-independent IFN-γ production in CD4 + and CD8 + T EM cells. Reducing the number of T EM cells through a depletion recovery procedure, we show that intravenous T EM activation determines neutrophil and monocyte recruitment and delays thrombus neovascularization and resolution. Examining T-cell recruitment in human venous stasis, we show that superficial varicose veins preferentially contain activated memory T cells. T EM orchestrate the inflammatory response in venous thrombosis affecting thrombus resolution. © 2016 American Heart Association, Inc.

Multisite Thrombus Imaging and Fibrin Content Estimation With a Single Whole-Body PET Scan in Rats.

Science.gov (United States)

Blasi, Francesco; Oliveira, Bruno L; Rietz, Tyson A; Rotile, Nicholas J; Naha, Pratap C; Cormode, David P; Izquierdo-Garcia, David; Catana, Ciprian; Caravan, Peter

2015-10-01

Thrombosis is a leading cause of morbidity and mortality worldwide. Current diagnostic strategies rely on imaging modalities that are specific for distinct vascular territories, but a thrombus-specific whole-body imaging approach is still missing. Moreover, imaging techniques to assess thrombus composition are underdeveloped, although therapeutic strategies may benefit from such technology. Therefore, our goal was to test whether positron emission tomography (PET) with the fibrin-binding probe (64)Cu-FBP8 allows multisite thrombus detection and fibrin content estimation. Thrombosis was induced in Sprague-Dawley rats (n=32) by ferric chloride application on both carotid artery and femoral vein. (64)Cu-FBP8-PET/CT imaging was performed 1, 3, or 7 days after thrombosis to detect thrombus location and to evaluate age-dependent changes in target uptake. Ex vivo biodistribution, autoradiography, and histopathology were performed to validate imaging results. Arterial and venous thrombi were localized on fused PET/CT images with high accuracy (97.6%; 95% confidence interval, 92-100). A single whole-body PET/MR imaging session was sufficient to reveal the location of both arterial and venous thrombi after (64)Cu-FBP8 administration. PET imaging showed that probe uptake was greater in younger clots than in older ones for both arterial and venous thrombosis (P<0.0001). Quantitative histopathology revealed an age-dependent reduction of thrombus fibrin content (P<0.001), consistent with PET results. Biodistribution and autoradiography further confirmed the imaging findings. We demonstrated that (64)Cu-FBP8-PET is a feasible approach for whole-body thrombus detection and that molecular imaging of fibrin can provide, noninvasively, insight into clot composition. © 2015 American Heart Association, Inc.

The development of a standard format for accelerator data analysis

International Nuclear Information System (INIS)

Cohen, S.

1989-01-01

The purpose of specifying a standard file format is to facilitate the analysis of data sampled by accelerator beam diagnostic instrumentation. The format's design needs to be flexible enough to allow storage of information from disparate diagnostic devices placed in the beam line. The goal of this project was to establish a standard file layout and syntax that can be generated and ''understood'' by a large set of applications running on the control and data-analysis computers at LAMPF as well as applications on personal computers. Only one file-parsing algorithm is needed for all computing systems. It is a straightforward process to code a parser for both the control computer and pc's once a consensus on the file syntax has been established. This paper describes the file format and the methods used to integrate the format into existing diagnostic and control software

Artificial aortic valve dysfunction due to pannus and thrombus – different methods of cardiac surgical management

Science.gov (United States)

Marcinkiewicz, Anna; Kośmider, Anna; Walczak, Andrzej; Zwoliński, Radosław; Jaszewski, Ryszard

2015-01-01

Introduction Approximately 60 000 prosthetic valves are implanted annually in the USA. The risk of prosthesis dysfunction ranges from 0.1% to 4% per year. Prosthesis valve dysfunction is usually caused by a thrombus obstructing the prosthetic discs. However, 10% of prosthetic valves are dysfunctional due to pannus formation, and 12% of prostheses are damaged by both fibrinous and thrombotic components. The authors present two patients with dysfunctional aortic prostheses who were referred for cardiac surgery. Different surgical solutions were used in the treatment of each case. Case study 1 The first patient was a 71-year-old woman whose medical history included arterial hypertension, stable coronary artery disease, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and hypercholesterolemia; she had previously undergone left-sided mastectomy and radiotherapy. The patient was admitted to the Cardiac Surgery Department due to aortic prosthesis dysfunction. Transthoracic echocardiography revealed complete obstruction of one disc and a severe reduction in the mobility of the second. The mean transvalvular gradient was very high. During the operation, pannus covering the discs’ surface was found. A biological aortic prosthesis was reimplanted without complications. Case study 2 The second patient was an 87-year-old woman with arterial hypertension, persistent atrial fibrillation, and COPD, whose past medical history included gastric ulcer disease and ischemic stroke. As in the case of the first patient, she was admitted due to valvular prosthesis dysfunction. Preoperative transthoracic echocardiography revealed an obstruction of the posterior prosthetic disc and significant aortic regurgitation. Transesophageal echocardiography and fluoroscopy confirmed the prosthetic dysfunction. During the operation, a thrombus growing around a minor pannus was found. The thrombus and pannus were removed, and normal functionality of the prosthetic valve was restored

‘Mother-in-child’ thrombectomy technique: a novel and effective approach to decrease intracoronary thrombus burden in acute myocardial infarction

Energy Technology Data Exchange (ETDEWEB)

Dauvergne, Christian; Araya, Mario [Department of Cardiology, Clinica Alemana, Santiago (Chile); Uriarte, Polentzi [Department of Cardiology, Instituto Nacional del Torax, Santiago (Chile); Novoa, Oscar; Novoa, Lilian [Department of Cardiology, Clinica Alemana, Santiago (Chile); Maluenda, Gabriel, E-mail: gabrielmaluenda@gmail.com [Department of Cardiology, Clinica Alemana, Santiago (Chile)

2013-01-15

Background: The presence of large thrombus burden in patients presenting with acute myocardial infarction (AMI) is common and associated with poor prognosis. This study aimed to describe the feasibility and safety of the novel ‘mother-in-child’ thrombectomy (MCT) technique in patients presenting with AMI and large thrombus burden undergoing percutaneous coronary intervention (PCI). Methods: We studied 13 patients presenting with AMI who underwent PCI with persistent large intracoronary thrombus after standard thrombectomy. The procedure was performed using a 5 F ‘Heartrail II-ST01’ catheter (Terumo Medical) into a 6 F guiding system. Angiographic assessment of thrombus burden and coronary flow was obtained at baseline, immediately after thrombectomy and at the end of the procedure. Results: The mean age was 55.9 ± 13.0 years and involved mostly males (76.9%). All patients underwent PCI via radial approach. Following MCT Thrombolysis In Myocardial Infarction (TIMI) flow improved by 2 or more degrees in 11 patients (84.5%), while visible angiographic thrombus was reduced in 11 patients (84.5%). In the final angiogram, normal TIMI flow was restored in 11 patients (84.5%), with normal myocardial ‘blush’ in 7 patients (53.8%) and total clearance of a visible thrombus in 7 patients (53.8%). Overall, 6 patients received thrombectomy as ‘stand-alone’ procedure. All patients were discharged alive after a mean of 5.6 ± 2 days. Conclusion: This initial report suggests that significant reduction in thrombus burden and improvement of the coronary flow can be safely achieved in patients presenting with AMI and large thrombus burden by using the novel MCT technique.

Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging

DEFF Research Database (Denmark)

de la Motte, Louise; Pedersen, Mads Møller; Thomsen, Carsten

2013-01-01

Magnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics...

The development of a standard format for accelerator data analysis

Energy Technology Data Exchange (ETDEWEB)

Cohen, S [Los Alamos National Lab., NM (USA)

1990-08-01

The purpose of specifying a standard file format is to facilitate the analysis of data sampled by accelerator beam-diagnostic instrumentation. The format's design needs to be flexible enough to allow storage of information from disparate diagnostic devices placed in the beam line. The goal of this project was to establish a standard file layout and syntax that can be generated and 'understood' by a large set of applications running on the control and data-analysis computers at LAMPF, as well as applications on personal computers. Only one file-parsing algorithm is needed for all computing systems. Once a consensus on the file syntax has been established, it is a straightforward process to code a parser for both the control computer and PCs. This paper describes the file format and the method used to integrate the format into existing diagnostic and control software. (orig.).

Arterial homograft and medical therapy in pseudoaneurysm of infrarenal aorta concomitant with recurrent right ventricular thrombus in Behcet's disease

International Nuclear Information System (INIS)

Vahedian, Jalal; Sadeghapour, Ali

2006-01-01

Pseudoaneurysm of the infrarenal aorta due to Behcet s disease is very rare. We report a case of pseudoaneurysm associated with Behcet s disease in a 17-year-old boy with a recurrent right ventricular thrombus successfully treated with revascularization using arterial homograft patch. Echocardiography examination revealed a right ventricular mass, thought to be a thrombus in an unusual location. Postoperatively, the findings of the pathologic examination confirmed the mass as a thrombus. When the patient was subsequently re-admitted to the emergency unit with complaints of severe abdominal pain, fever, fatigue, sinus tachycardia, and a pulsating and tender abdominal mass, a right ventricular thrombus and a large pseudoaneurysm of the abdominal aorta were found on echocardiography and angiography. The patient underwent resection of the aortic aneurysm and aortoplasty, using arterial homograft patch, and received immunosuppressive and anticoagulation therapy. The thrombus of the right ventricle disappeared 4 months later. This case indicates that a right ventricular thrombosis in Behcet s disease may be managed by medical therapy. (author)

Discrimination between platelet-mediated and coagulation-mediated mechanisms in a model of complex thrombus formation in vivo

International Nuclear Information System (INIS)

Cadroy, Y.; Horbett, T.A.; Hanson, S.R.

1989-01-01

To study mechanisms of complex thrombus formation in vivo, and to compare the relative antithrombotic effects of anticoagulants and antiplatelet agents, a model was developed in baboons. Segments of collagen-coated tubing followed by two sequentially placed expansion chambers exhibiting disturbed flow patterns were exposed to native blood under laminar flow conditions. The device was incorporated for 1 hour into an exteriorized arteriovenous shunt in baboons under controlled blood flow (20 ml/min). Morphologic evaluation by scanning electron microscopy showed that thrombi associated with collagen were relatively rich in platelets but thrombi in the chambers were rich in fibrin and red cells. Deposition of indium 111-labeled platelets was continuously measured with a scintillation camera. Platelet deposition increased in a linear (collagen-coated segment) or exponential (chambers 1 and 2) fashion over time, with values after 40 minutes averaging 24.1 +/- 3.3 x 10(8) platelets (collagen segment), 16.7 +/- 3.4 x 10(8) platelets (chamber 1), and 8.4 +/- 2.4 x 10(8) platelets (chamber 2). Total fibrinogen deposition after 40 minutes was determined by using iodine 125-labeled baboon fibrinogen and averaged 0.58 +/- 0.14 mg in the collagen segment, 1.51 +/- 0.27 mg in chamber 1, and 0.95 +/- 0.25 mg in chamber 2. Plasma levels of beta-thromboglobulin (beta TG), platelet-factor 4 (PF4), and fibrinopeptide A (FPA) increased fourfold to fivefold after 60 minutes of blood exposure to the thrombotic device. Platelet deposition onto the collagen segment, chamber 1, and chamber 2 was linearly dependent on the circulating platelet count. Platelet accumulation in chamber 1 and chamber 2 was also dependent on the presence of the proximal collagen segment

A Stable Formation Control Using Approximation of Translational and Angular Accelerations

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Viet-Hong Tran

2011-03-01

Full Text Available In this paper, a stable leader-following formation control for multiple non-holonomic mobile robot systems using only limited on-board sensor information is proposed. The control can be used for the conventional single leader – single follower (SLSF or for novel two leaders – single follower (TLSF schemes. The control algorithm utilizes estimations of the leaders' translational and angular accelerations in a simple form to reduce the measurement of indirect information. Simulation results show that the TLSF scheme can suppress the oscillation and damping in formation of large robot teams.

Exogenous modification of platelet membranes with the omega-3 fatty acids EPA and DHA reduces platelet procoagulant activity and thrombus formation.

Science.gov (United States)

Larson, Mark K; Tormoen, Garth W; Weaver, Lucinda J; Luepke, Kristen J; Patel, Ishan A; Hjelmen, Carl E; Ensz, Nicole M; McComas, Leah S; McCarty, Owen J T

2013-02-01

Several studies have implicated the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in inhibition of normal platelet function, suggesting a role for platelets in EPA- and DHA-mediated cardioprotection. However, it is unclear whether the cardioprotective mechanisms arise from alterations to platelet-platelet, platelet-matrix, or platelet-coagulation factor interactions. Our previous results led us to hypothesize that EPA and DHA alter the ability of platelets to catalyze the generation of thrombin. We tested this hypothesis by exogenously modifying platelet membranes with EPA and DHA, which resulted in compositional changes analogous to increased dietary EPA and DHA intake. Platelets treated with EPA and DHA showed reductions in the rate of thrombin generation and exposure of platelet phosphatidylserine. In addition, treatment of platelets with EPA and DHA decreased thrombus formation and altered the processing of thrombin precursor proteins. Furthermore, treatment of whole blood with EPA and DHA resulted in increased occlusion time and a sharply reduced accumulation of fibrin under flow conditions. These results demonstrate that EPA and DHA inhibit, but do not eliminate, the ability of platelets to catalyze thrombin generation in vitro. The ability of EPA and DHA to reduce the procoagulant function of platelets provides a possible mechanism behind the cardioprotective phenotype in individuals consuming high levels of EPA and DHA.

Average accelerator simulation Truebeam using phase space in IAEA format

International Nuclear Information System (INIS)

Santana, Emico Ferreira; Milian, Felix Mas; Paixao, Paulo Oliveira; Costa, Raranna Alves da; Velasco, Fermin Garcia

2015-01-01

In this paper is used a computational code of radiation transport simulation based on Monte Carlo technique, in order to model a linear accelerator of treatment by Radiotherapy. This work is the initial step of future proposals which aim to study several treatment of patient by Radiotherapy, employing computational modeling in cooperation with the institutions UESC, IPEN, UFRJ e COI. The Chosen simulation code is GATE/Geant4. The average accelerator is TrueBeam of Varian Company. The geometric modeling was based in technical manuals, and radiation sources on the phase space for photons, provided by manufacturer in the IAEA (International Atomic Energy Agency) format. The simulations were carried out in equal conditions to experimental measurements. Were studied photons beams of 6MV, with 10 per 10 cm of field, focusing on a water phantom. For validation were compared dose curves in depth, lateral profiles in different depths of the simulated results and experimental data. The final modeling of this accelerator will be used in future works involving treatments and real patients. (author)

Abdominal aortic aneurysm calcification and thrombus volume are not associated with outcome following endovascular abdominal aortic aneurysm repair

International Nuclear Information System (INIS)

Rai, Divyajeet; Velu, Ramesh; Tosenovsky, Patrik; Quigley, Francis; Wisniowski, Brendan; Walker, Philip J.; Bradshaw, Barbara; Golledge, Jonathan

2014-01-01

Aortic calcification and thrombus have been postulated to worsen outcome following endovascular abdominal aortic aneurysm repair (EVAR). The purpose of this study was to assess the association of abdominal aortic aneurysm (AAA) calcification and thrombus volume with outcome following EVAR using a reproducible, quantifiable computed tomography (CT) assessment protocol. Patients with elective EVAR performed between January 2002 and 2012 at the Townsville Hospital, Mater Private Hospital (Townsville) and Royal Brisbane and Women's Hospital (RBWH) were included if preoperative CTAs were available for analysis. AAA calcification and thrombus volume were measured using a semiautomated workstation protocol. Outcomes were assessed in terms of clinical failure, endoleak (type I, type II) and reintervention. Univariate and multivariate analyses were performed. Median follow-up was 1.7 years and the interquartile range 1.0-3.8 years. One hundred thirty-four patients undergoing elective EVAR were included in the study. Rates of primary clinical success and freedom from reintervention were 82.8 % and 88.9 % at the 24-month follow-up. AAA calcification and thrombus volume were not associated with clinical failure, type I endoleak, type II endoleak or reintervention. AAA calcification and thrombus volume were not associated with poorer outcome after EVAR in this study. (orig.)

Abdominal aortic aneurysm calcification and thrombus volume are not associated with outcome following endovascular abdominal aortic aneurysm repair

Energy Technology Data Exchange (ETDEWEB)

Rai, Divyajeet; Velu, Ramesh; Tosenovsky, Patrik; Quigley, Francis [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); The Townsville Hospital, Department of Vascular and Endovascular Surgery, Douglas (Australia); Wisniowski, Brendan; Walker, Philip J. [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); University of Queensland, School of Medicine and Centre for Clinical Research, Department of Vascular Surgery, Royal Brisbane and Women' s Hospital, Herston, QLD (Australia); Bradshaw, Barbara [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); Golledge, Jonathan [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); The Townsville Hospital, Department of Vascular and Endovascular Surgery, Douglas (Australia); University of Queensland, School of Medicine and Centre for Clinical Research, Department of Vascular Surgery, Royal Brisbane and Women' s Hospital, Herston, QLD (Australia)

2014-08-15

Aortic calcification and thrombus have been postulated to worsen outcome following endovascular abdominal aortic aneurysm repair (EVAR). The purpose of this study was to assess the association of abdominal aortic aneurysm (AAA) calcification and thrombus volume with outcome following EVAR using a reproducible, quantifiable computed tomography (CT) assessment protocol. Patients with elective EVAR performed between January 2002 and 2012 at the Townsville Hospital, Mater Private Hospital (Townsville) and Royal Brisbane and Women's Hospital (RBWH) were included if preoperative CTAs were available for analysis. AAA calcification and thrombus volume were measured using a semiautomated workstation protocol. Outcomes were assessed in terms of clinical failure, endoleak (type I, type II) and reintervention. Univariate and multivariate analyses were performed. Median follow-up was 1.7 years and the interquartile range 1.0-3.8 years. One hundred thirty-four patients undergoing elective EVAR were included in the study. Rates of primary clinical success and freedom from reintervention were 82.8 % and 88.9 % at the 24-month follow-up. AAA calcification and thrombus volume were not associated with clinical failure, type I endoleak, type II endoleak or reintervention. AAA calcification and thrombus volume were not associated with poorer outcome after EVAR in this study. (orig.)

Thrombus Size is Associated with Etiology of Deep Venous Thrombosis – A Cross-Sectional Study

OpenAIRE

Vučić, Nikša; Magdić, Tihana; Krnić, Anton; Včev, Aleksandar; Božić, Dubravko

2005-01-01

The aim of this study was to evaluate the impact of risk factors for deep vein thrombosis (DVT) on thrombus sizes in lower extremities. The size and extent of thrombus was scored according to International Consensus Committee for venous disease classification. After the diagnosis of DVT was established and its size scored, predominant risk factors for DVT in each patient were identified (malignant disease, thrombophilia, postoperative state, hormonal therapy, heredity, limb trauma, immobiliza...

Imaging thrombus with radiolabelled monoclonal antibody to platelets

Energy Technology Data Exchange (ETDEWEB)

Peters, A.M.; Lavender, J.P.; Needham, S.G.; Loutfi, I.; Snook, D.; Epenetos, A.A.; Lumley, P.; Keery, R.J.; Hogg, N.

1986-12-13

A study was conducted evaluating a method of imaging thrombus with platelets radiolabelled with a /sup 111/In labelled monoclonal antibody, P256, directed to the platelet surface glycoprotein complex IIb/IIIa. when the number of receptors occupied by P256 was less than 3% of the total available on the platelet surface, platelet function was undisturbed. P256 was radiolabelled with /sup 111/In using diethylenetriaminepenta-acetic acid, which achieved a specific activity of 185 MBq (5 mCi)/mg. No impairment of immunoreactivity was detected at this specific activity. Platelets were labelled with radiolabelled monoclonal antibody in vitro in two patients at a receptor occupancy of 6% and in vivo in six patients at a receptor occupancy of 1%. In vivo recovery and biodistribution kinetics suggested that after in vitro labelling platelets were minimally activated. The /sup 111/In kinetics recorded after intravenous P256 suggested rapid and efficient radiolabelling of platelets and gave no indication of platelet activation. Of the six patients who received intravenous P256, three had documented thrombus, two of whom gave positive results on P256 platelet scintigraphy. The third had chronic deep venous thrombosis and was scintigraphically negative.

Incidence and Outcomes of Inferior Vena Cava Filter Thrombus during Catheter-directed Thrombolysis for Proximal Deep Venous Thrombosis.

Science.gov (United States)

Jiang, Jianguang; Tu, Jianfei; Jia, Zhongzhi; Chen, Jiezhong; Cao, Haitao; Meng, Qingli; Fuller, Tyler A; Tian, Feng

2017-01-01

The aim of the study was to retrospectively evaluate the incidence and outcomes of inferior vena cava (IVC) filter thrombus during catheter-directed thrombolysis (CDT) for acute proximal deep venous thrombosis (DVT). From October 2006 to June 2015, patients diagnosed with acute proximal DVT and received CDT after a retrievable IVC filter was placed were included. The incidence, treatment, and outcomes of IVC filter thrombus during CDT were recorded and analyzed. A total of 189 patients (91 women, 98 men; mean age, 57.6 ± 9.8 years; range, 24-85 years) were included in this study. Among the 189 cases, the DVTs involved popliteal iliofemoral veins in 54 patients, iliofemoral veins in 113 patients, and iliac veins in 22 patients, of which 18 patients had thrombus extended into the IVC. Of the 189 patients, a total of 8 (4.2%, 8 of 189) patients were identified with IVC filter thrombus during CDT. The IVC filter thrombus was detected on a median of 2 days (range, 2-4 days) of CDT therapy, including small-size (n = 6) and large-size (n = 2) filter thrombus. Of the 8 patients, CDTs were performed with a mean 7.6 ± 1.1 days (range, 6-11 days) after the presence of symptoms for the treatment of proximal DVT, and all the IVC filter thrombi were lysed during CDT for the proximal DVT. All the IVC filters were removed successfully with a mean of 12.8 ± 0.93 days from placement. There were no procedure- or thrombolysis-related major complications, and no symptomatic pulmonary embolism breakthrough was seen in any of the patients after the filter placement. IVC filter thrombus during CDT for the acute proximal DVT is uncommon, and all of them did not need any additional treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

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

Science.gov (United States)

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

2017-12-01

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

Role of presurgical targeted molecular therapy in renal cell carcinoma with an inferior vena cava tumor thrombus

Directory of Open Access Journals (Sweden)

Peng C

2018-04-01

Full Text Available Cheng Peng,1,* Liangyou Gu,1,* Lei Wang,2 Qingbo Huang,1 Baojun Wang,1 Gang Guo,1 Yang Fan,1 Yu Gao,1 Xin Ma,1 Xu Zhang1 1Department of Urology, State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital, Chinese PLA Medical Academy, Beijing, People’s Republic of China; 2Department of Urology, Chinese PLA 534 Hospital, Luoyang, People’s Republic of China *These authors contributed equally to this work Purpose: The clinical benefit of targeted molecular therapy (TMT in renal cell carcinoma (RCC with an inferior vena cava (IVC tumor thrombus remains controversial. The aim of this study was to investigate the effects of presurgical TMT on the heights and levels of IVC thrombi, and to assess its impact on surgical strategy. Patients and methods: We retrospectively reviewed data from 18 patients with RCC involving IVC tumor thrombi who were treated at our hospital with presurgical TMT followed by an IVC thrombectomy. The changes in heights and levels of the IVC thrombi were compared using computed tomography or magnetic resonance imaging. Clinicopathological factors were also evaluated to assess their association with TMT efficacy. Results: The tumor thrombus levels before TMT were stage I in 1 patient (5.6%, II in 12 patients (66.7%, III in 4 patients (22.2%, and IV in 1 patient (5.6%. After a median of two treatment cycles (range: 1–3, the thrombus height decreased measurably in 11 patients (61.1% with an average shrinkage of 17.7%. The thrombus height remained stable in five patients (27.8% and was enlarged in two (11.1%. Downstaging of the thrombus level occurred in four patients (22.2%; the surgical strategy was modified in three patients (16.7% to avoid cardiopulmonary bypass and complicated liver mobilization under robot-assisted laparoscopy. Furthermore, a higher neutrophil count tended to be associated with a worse clinical TMT-associated outcome (P=0.056. Conclusion: Our data suggest a limited influence of presurgical TMT

Synthesis of PEGylated polyglutamic acid peptide dendrimer and its application in dissolving thrombus.

Science.gov (United States)

Zhang, Shao-Fei; Gao, Chunmei; Lü, Shaoyu; He, Jiujun; Liu, Mingzhu; Wu, Can; Liu, Yijing; Zhang, Xinyu; Liu, Zhen

2017-11-01

Nattokinase (NK) has been used as a new generation thrombolytic drug, due to its high safety, low cost and low side effects. However, it is sensitive to external environment and may lose the enzyme activity easily. Peptide dendrimer possesses functional groups on its surface, adjustable sizes, biodegradability, biocompatibility, and low toxicity, which could be used as ideal carrier for drug protection and delivery. Demonstrated for the first time in this paper, a PEGylated dendrimer (G n -PEG-G n ) composed of polyglutamic acid is designed and synthesized as delivery platform of NK for thrombus treatment. A panel of PEGylated dendrimers with three different generations of 2, 3, 4 was prepared to investigate the effect of dendrimer architecture on the properties and therapeutic efficacy of the resultant NK-loaded delivery systems in terms of the morphology, dimension and enzyme activity. The results demonstrated that the NK-loaded G 3 -PEG-G 3 (G 3 -PEG-G 3 /NK ratio of 6/1), of all the formulations, displayed the optimal enzyme activity for dissolving thrombus in vitro, thus offering great potential for the treatment of thrombus. Copyright © 2017 Elsevier B.V. All rights reserved.

Sensitivity of 3D gradient recalled echo susceptibility-weighted imaging technique compared to computed tomography angiography for detection of middle cerebral artery thrombus in acute stroke

Directory of Open Access Journals (Sweden)

Amit Agarwal

2014-11-01

Full Text Available We aimed at comparing the sensitivity of magnetic resonance (MR susceptibility-weighted imaging (SWI with computed tomography angiography (CTA in the detection of middle cerebral artery (MCA thrombus in acute stroke. Seventy-nine patients with acute MCA stroke was selected using our search engine software; only the ones showing restricted diffusion in the MCA territory on diffusion-weighted images were included. We finally selected 35 patients who had done both MRI (including SWI and CTA. Twenty random subjects with completely normal MRI (including SWI exam were selected as control. Two neuroradiologists (blinded to the presence or absence of stroke reviewed the SW images and then compared the findings with CT angiogram (in patients with stroke. The number of MCA segments showing thrombus in each patient was tabulated to estimate the thrombus burden. Thrombus was detected on SWI in one or more MCA segments in 30 out of 35 patients, on the first review. Of the 30, SWI showed thrombus in more than one MCA segments in 7 patients. CTA depicted branch occlusion in 31 cases. Thrombus was seen on both SWI and CTA in 28 patients. Thrombus was noted in two patients on SWI only, with no corresponding abnormality seen on CTA. Two patients with acute MCA showed no vascular occlusion or thrombus on either CTA or SWI. Only two case of false-positive thrombus was reported in normal control subjects. Susceptibility-weighted images had sensitivity and specificity of 86% and 90% respectively, with positive predictive value 94%. Sensitivity was 86% for SWI, compared with 89% for CTA, and this difference was statistically insignificant (P>0.05. Of all the positive cases on CTA (31 corresponding thrombus was seen on SWI in 90% of subjects (28 of 31. Susceptibility-weighted imaging has high sensitivity for detection of thrombus in acute MCA stroke. Moreover, SWI is a powerful technique for estimation of thrombus burden, which can be challenging on CTA.

Fully automatic detection and segmentation of abdominal aortic thrombus in post-operative CTA images using Deep Convolutional Neural Networks.

Science.gov (United States)

López-Linares, Karen; Aranjuelo, Nerea; Kabongo, Luis; Maclair, Gregory; Lete, Nerea; Ceresa, Mario; García-Familiar, Ainhoa; Macía, Iván; González Ballester, Miguel A

2018-05-01

Computerized Tomography Angiography (CTA) based follow-up of Abdominal Aortic Aneurysms (AAA) treated with Endovascular Aneurysm Repair (EVAR) is essential to evaluate the progress of the patient and detect complications. In this context, accurate quantification of post-operative thrombus volume is required. However, a proper evaluation is hindered by the lack of automatic, robust and reproducible thrombus segmentation algorithms. We propose a new fully automatic approach based on Deep Convolutional Neural Networks (DCNN) for robust and reproducible thrombus region of interest detection and subsequent fine thrombus segmentation. The DetecNet detection network is adapted to perform region of interest extraction from a complete CTA and a new segmentation network architecture, based on Fully Convolutional Networks and a Holistically-Nested Edge Detection Network, is presented. These networks are trained, validated and tested in 13 post-operative CTA volumes of different patients using a 4-fold cross-validation approach to provide more robustness to the results. Our pipeline achieves a Dice score of more than 82% for post-operative thrombus segmentation and provides a mean relative volume difference between ground truth and automatic segmentation that lays within the experienced human observer variance without the need of human intervention in most common cases. Copyright © 2018 Elsevier B.V. All rights reserved.

Surgical Treatment of Renal Cell Carcinoma with Inferior Vena Cava Thrombus: Using Liver Mobilization Technique to Avoid Cardiopulmonary Bypass

Directory of Open Access Journals (Sweden)

Tawatchai Taweemonkongsap

2008-04-01

CONCLUSION: These results support the aggressive surgical removal of RCC with IVC thrombus as the initial treatment. Most of the thrombi can be approached and safely controlled by a transabdominal approach without any form of bypass. Tumour thrombus removal provides a high survival chance and offers improvement in quality of life.

Baryon bias and structure formation in an accelerating universe

International Nuclear Information System (INIS)

Amendola, Luca; Tocchini-Valentini, Domenico

2002-01-01

In most models of dark energy the structure formation stops after the accelerated expansion begins. In contrast, we show that the coupling of dark energy to dark matter may induce the growth of perturbations even in the accelerated regime. In particular, we show that this occurs in the models proposed to solve the cosmic coincidence problem, in which the ratio of dark energy to dark matter is constant. Depending on the parameters, the growth may be much faster than in a standard matter-dominated era. Moreover, if the dark energy couples only to dark matter and not to baryons, as requested by the constraints imposed by local gravity measurements, the baryon fluctuations develop a constant, scale-independent, large-scale bias which is in principle directly observable. We find that a lower limit to the baryon bias b>0.5 requires the total effective parameter of state w e =1+p/ρ to be larger than 0.6 while a limit b>0.73 would rule out the model

Dissolution of pre-existing platelet thrombus by synergistic administration of low concentrations of bifunctional antibodies against β3 integrin.

Directory of Open Access Journals (Sweden)

Suying Dang

Full Text Available Most antithrombotic approaches target prevention rather than the more clinically relevant issue of resolution of an existing thrombus. In this study, we describe a novel and effective therapeutic strategy for ex vivo clearance of pre-existing platelet thrombus by the combination of two bifunctional platelet GPIIIa49-66 ligands that target different parts of the arterial thrombus. We produced an additional GPIIIa49-66 agent (named APAC, which homes to activated platelets. Like our previously described SLK (which targets newly deposited fibrin strands surrounding the platelet thrombus, APAC destroys platelet aggregates ex vivo in an identical fashion with 85% destruction of platelet aggregates at 2 hours. The combined application of APAC and SLK demonstrated a ~2 fold greater platelet thrombus dissolution than either agent alone at a low concentration (0.025 µM. Platelet-rich clot lysis experiments demonstrated the time required for 50% platelet-rich fibrin clot lysis (T(50% by APAC (95 ± 6.1 min or SLK (145 ± 7.1 min was much longer than that by combined APAC + SLK (65 ± 7.6 min at the final concentration of 0.025 µM (APAC + SLK vs APAC, p<0.05; APAC + SLK vs SLK, p<0.01. Thus these low concentrations of a combination of both agents are likely to be more effective and less toxic when used therapeutically in vivo.

Evaluation of accelerated UV and thermal testing for benzene formation in beverages containing benzoate and ascorbic acid.

Science.gov (United States)

Nyman, Patricia J; Wamer, Wayne G; Begley, Timothy H; Diachenko, Gregory W; Perfetti, Gracia A

2010-04-01

Under certain conditions, benzene can form in beverages containing benzoic and ascorbic acids. The American Beverage Assn. (ABA) has published guidelines to help manufacturers mitigate benzene formation in beverages. These guidelines recommend accelerated testing conditions to test product formulations, because exposure to ultraviolet (UV) light and elevated temperature over the shelf life of the beverage may result in benzene formation in products containing benzoic and ascorbic acids. In this study, the effects of UVA exposure on benzene formation were determined. Benzene formation was examined for samples contained in UV stabilized and non-UV stabilized packaging. Additionally, the usefulness of accelerated thermal testing to simulate end of shelf-life benzene formation was evaluated for samples containing either benzoic or ascorbic acid, or both. The 24 h studies showed that under intense UVA light benzene levels increased by as much as 53% in model solutions stored in non-UV stabilized bottles, whereas the use of UV stabilized polyethylene terephthalate bottles reduced benzene formation by about 13% relative to the non-UV stabilized bottles. Similar trends were observed for the 7 d study. Retail beverages and positive and negative controls were used to study the accelerated thermal testing conditions. The amount of benzene found in the positive controls and cranberry juice suggests that testing at 40 degrees C for 14 d may more reliably simulate end of shelf-life benzene formation in beverages. Except for cranberry juice, retail beverages were not found to contain detectable amounts of benzene (<0.05 ng/g) at the end of their shelf lives.

Formation of GEMS from shock-accelerated crystalline dust in Superbubbles

International Nuclear Information System (INIS)

Westphal, A; Bradley, J P

2004-01-01

Interplanetary dust particles (IDPs) contain enigmatic sub-micron components called GEMS (Glass with Embedded Metal and Sulfides). The compositions and structures of GEMS indicate that they have been processed by exposure to ionizing radiation but details of the actual irradiation environment(s) have remained elusive. Here we propose a mechanism and astrophysical site for GEMS formation that explains for the first time the following key properties of GEMS; they are stoichiometrically enriched in oxygen and systematically depleted in S, Mg, Ca and Fe (relative to solar abundances), most have normal (solar) oxygen isotopic compositions, they exhibit a strikingly narrow size distribution (0.1-0.5 (micro)m diameter), and some of them contain ''relict'' crystals within their silicate glass matrices. We show that the compositions, size distribution, and survival of relict crystals are inconsistent with amorphization by particles accelerated by diffusive shock acceleration. Instead, we propose that GEMS are formed from crystalline grains that condense in stellar outflows from massive stars in OB associations, are accelerated in encounters with frequent supernova shocks inside the associated superbubble, and are implanted with atoms from the hot gas in the SB interior. We thus reverse the usual roles of target and projectile. Rather than being bombarded at rest by energetic ions, grains are accelerated and bombarded by a nearly monovelocity beam of atoms as viewed in their rest frame. Meyer, Drury and Ellison have proposed that galactic cosmic rays originate from ions sputtered from such accelerated dust grains. We suggest that GEMS are surviving members of a population of fast grains that constitute the long-sought source material for galactic cosmic rays. Thus, representatives of the GCR source material may have been awaiting discovery in cosmic dust labs for the last thirty years

Frequency of left atrial thrombus detected by transesophageal echocardiography in patients of tight mitral stenosis having negative trans-thoracic echocardiography at gulab devi cardiac complex

International Nuclear Information System (INIS)

Fayyaz, A.; Iqbal, M.W.

2014-01-01

Introduction: Patients with mitral stenosis (MS) having atrial fibrillation (AF) are more prone to develop left atrial (LA) thrombus. Systemic embolism, related to LA thrombus is a well-known risk of Percutaneous Mitral Balloon Valvotomy (PMBV) of the mitral valve. Therefore presence of LA thrombus is a contraindication to PMBV. Objective: Objective of this study was to detect the frequency of LA thrombus by transesophageal echocardiography (TEE) in patients of tight MS in whom transthoracic echocardiography (TTE) could not detect any LA thrombus. Patients and Methods: In this cross sectional study, we took 100 indoor patients with tight MS on non-probability consecutive sampling. Data was collected after meeting inclusion criteria. Patients were taken in this study after acquiring written informed consent. Symptoms were inquired from all patients and functional status was assessed by New York Heart Association class. Unstable patients were medically managed before the procedure. TEE was done on the same day before undergoing PMBV to look for clot in LA. Results: The mean age of the patients was 32.20 years and SD was 11.3 years. There were 36(36%) male patients and 64(64%) female patients. LA thrombus was present in 40% of patients on TEE out of which 19 were male patients (52.77%) and 21 were female patients (32.81%). Conclusion: Patients with mitral stenosis having AF are more prone to develop LA thrombus. In this study, the frequency of LA thrombus was 40% recorded, which is high. Due to the potential risk of embolization, it is strongly recommended to perform TEE in patients with normal TTE study before undergoing PMBV. The presence of a LA thrombus should be considered a contraindication to the PMBV of the mitral valve. (author)

Thrombus-in-Transit: A Case for a Multidisciplinary Hospital-Based Pulmonary Embolism System of Care.

Science.gov (United States)

Pappas, Anthony J; Knight, Stephen W; McLean, Katherine Zanyk; Bork, Susan; Kurz, Michael C; Sawyer, Kelly N

2016-09-01

Venous thromboembolism, including pulmonary embolism (PE), is a common disease identified in the emergency department that carries significant morbidity and mortality. In its most severe form, PE is fulminant and characterized by cardiac arrest and death. In the midst of risk-stratifying PE by using echocardiography to assess right ventricular function, thrombus-in-transit (free-floating clot in the right atrium or ventricle) may be seen. We present a case of a 49-year-old man diagnosed with an acute saddle PE who was incidentally found to have a thrombus-in-transit and patent foramen ovale and required open thrombectomy. Identification of these additional potentially life-threatening features was possible only due to our availability of risk-stratification resources, specifically bedside echocardiography. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Albeit rare, with a reported incidence estimated at 4%, the presence of thrombus-in-transit may change emergent clinical management. A multidisciplinary team of resources should be considered emergently as part of a hospital-based PE system of care. Copyright © 2016 Elsevier Inc. All rights reserved.

Massive Pulmonary Embolism: Treatment with Thrombus Fragmentation and Local Fibrinolysis with Recombinant Human-Tissue Plasminogen Activator

International Nuclear Information System (INIS)

Stock, Klaus Wilhelm; Jacob, Augustinus Ludwig; Schnabel, Karl Jakob; Bongartz, Georg; Steinbrich, Wolfgang

1997-01-01

Purpose: To report the results of thrombus fragmentation in combination with local fibrinolysis using recombinant human-tissue plasminogen activator (rtPA) in patients with massive pulmonary embolism. Methods: Five patients with massive pulmonary embolism were treated with thrombus fragmentation followed by intrapulmonary injection of rtPA. Clot fragmentation was performed with a guidewire, angiographic catheter, and balloon catheter. Three patients had undergone recent surgery; one of them received a reduced dosage of rtPA. Results: All patients survived and showed clinical improvement with a resultant significant (p < 0.05) decrease in the pulmonary blood pressure (mean systolic pulmonary blood pressure before treatment, 49 mmHg; 4 hr after treatment, 28 mmHg). Angiographic follow-up in three patients revealed a decrease in thrombus material and an increase in pulmonary perfusion. Two patients developed retroperitoneal hematomas requiring transfusion. Conclusion: Clot fragmentation and local fibrinolysis with rtPA was an effective therapy for massive pulmonary embolism. Bleeding at the puncture site was a frequent complication

Mural thrombus and the progression of abdominal aortic aneurysms: a large population-based prospective cohort study

DEFF Research Database (Denmark)

Behr-Rasmussen, Carsten; Grøndal, Nikolaj Fibiger; Thomsen, Marie Dahl

2014-01-01

diagnosed in men aged 65-74 years. The relative cross-sectional area covered by the mural thrombus was estimated by a semiautomatic method using ultrasound equipment to measure the area of the ellipses, and adapting the inner ellipse (IA) to the luminal border of the thrombus and the outer ellipse...... to the area inside the media border (OA). The relative thrombus area was then calculated as ((OA-IA)/OU) × 100%. Four hundred and sixteen of the patients with AAA were eligible for analysis. RESULTS: The mean size of the AAA was 40.6 mm, and the mean observation time was 1.78 years. In the group with AAAs...... measuring 30-34 mm, 42% had ILT, with a mean relative size of 12% of the outer area. In the group with AAAs measuring >64 mm, the presence of ILT increased to 100%, with a mean relative size of 70% of the outer area. Univariate analysis showed relative ILT size, aortic diameter, smoking history...

Severe reversible dilated cardiomyopathy associated with a large left ventricular thrombus in a young child with middle aortic syndrome

OpenAIRE

Ponniah, U; Overholt, E

2014-01-01

this article reports a case of a seven-year girl who presented with severe dilated cardiomyopathy (DCM) associated with a large thrombus in the left ventricle (LV). She had a long segment stenosis of the lower thoracic descending aorta, possibly due to non-specific aortitis and underwent successful stent angioplasty. The LV thrombus resolved after heparin without sequelae.

The Accelerator Markup Language and the Universal Accelerator Parser

International Nuclear Information System (INIS)

Sagan, D.; Forster, M.; Cornell U., LNS; Bates, D.A.; LBL, Berkeley; Wolski, A.; Liverpool U.; Cockcroft Inst. Accel. Sci. Tech.; Schmidt, F.; CERN; Walker, N.J.; DESY; Larrieu, T.; Roblin, Y.; Jefferson Lab; Pelaia, T.; Oak Ridge; Tenenbaum, P.; Woodley, M.; SLAC; Reiche, S.; UCLA

2006-01-01

A major obstacle to collaboration on accelerator projects has been the sharing of lattice description files between modeling codes. To address this problem, a lattice description format called Accelerator Markup Language (AML) has been created. AML is based upon the standard eXtensible Markup Language (XML) format; this provides the flexibility for AML to be easily extended to satisfy changing requirements. In conjunction with AML, a software library, called the Universal Accelerator Parser (UAP), is being developed to speed the integration of AML into any program. The UAP is structured to make it relatively straightforward (by giving appropriate specifications) to read and write lattice files in any format. This will allow programs that use the UAP code to read a variety of different file formats. Additionally, this will greatly simplify conversion of files from one format to another. Currently, besides AML, the UAP supports the MAD lattice format

Size of the thrombus in acute deep vein thrombosis and the significance of patients' age and sex.

Science.gov (United States)

Kierkegaard, A

1981-01-01

To determine the significance of patients' age and sex on the size of the thrombus in acute deep vein thrombosis, 420 consecutive phlebograms with acute deep vein thrombosis were studied. A significant correlation between the size of the thrombus and increasing age of the patient as well as the sex of male was noted. It is concluded that older patients and men often are at a high risk of pulmonary embolism at the time of diagnosis.

Giant tumor thrombus in the right atrium clearly detected by /sup 111/In-oxine labeled platelet scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Takeda, T; Ishikawa, N; Satoh, A; Masuda, Y; Hiramatsu, Y; Akisada, M; Sakakibara, Y

1985-07-01

A 54-year-old man was admitted to hospital with a 3-month history of progressive dyspnea with coughing. A giant right atrial mass, originating from a hepatocellular carcinoma, was visualized by computed tomography, and digital subtraction angiography. The volume if the right atrial mass was increasing rapidly. It was therefore essential to determine whether this giant mass was a tumor thrombus or a multiplication of the hepatocellular carcinoma. /sup 111/In-oxine labeled platelet scintigraphy revealed active accumulation in the right atrium caused by the presence of active platelet deposition, and slight accumulation in the lung fields probably due to embolic showers originating from the tumor thrombus in the right atrium. This is the first case report showing that /sup 111/In-oxine labeled platelet scintigraphy can aid in confirming the nature of a giant tumor thrombus in the right atrium and can clarify the pathogenesis of the respiratory symptoms.

Ibrutinib Inhibits Platelet Integrin αIIbβ3 Outside-In Signaling and Thrombus Stability But Not Adhesion to Collagen.

Science.gov (United States)

Bye, Alexander P; Unsworth, Amanda J; Vaiyapuri, Sakthivel; Stainer, Alexander R; Fry, Michael J; Gibbins, Jonathan M

2015-11-01

Ibrutinib is an irreversible Bruton tyrosine kinase inhibitor approved for treatment of Waldenstrom macroglobulinemia, chronic lymphocytic leukemia, and mantle cell lymphoma that increases the risk of bleeding among patients. Platelets from ibrutinib-treated patients exhibit deficiencies in collagen-evoked signaling in suspension; however, the significance of this observation and how it relates to bleeding risk is unclear, as platelets encounter immobile collagen in vivo. We sought to clarify the effects of ibrutinib on platelet function to better understand the mechanism underlying bleeding risk. By comparing signaling in suspension and during adhesion to immobilized ligands, we found that the collagen signaling deficiency caused by ibrutinib is milder during adhesion to immobilized collagen. We also found that platelets in whole blood treated with ibrutinib adhered to collagen under arterial shear but formed unstable thrombi, suggesting that the collagen signaling deficiency caused by ibrutinib may not be the predominant cause of bleeding in vivo. However, clot retraction and signaling evoked by platelet adhesion to immobilized fibrinogen were also inhibited by ibrutinib, indicating that integrin αIIbβ3 outside-in signaling is also effected in addition to GPVI signaling. When ibrutinib was combined with the P2Y12 inhibitor, cangrelor, thrombus formation under arterial shear was inhibited additively. These findings suggest that (1) ibrutinib causes GPVI and integrin αIIbβ3 platelet signaling deficiencies that result in formation of unstable thrombi and may contribute toward bleeding observed in vivo and (2) combining ibrutinib with P2Y12 antagonists, which also inhibit thrombus stability, may have a detrimental effect on hemostasis. © 2015 American Heart Association, Inc.

Surgical Treatment for Thrombus Straddling a Patent Foramen Ovale

Directory of Open Access Journals (Sweden)

Marcos Aurélio Barboza de Oliveira

Full Text Available Abstract We present a case of a 41-year-old female with deep vein thrombosis after abdominal surgery. The patient quickly developed severe pulmonary embolism and stroke representative of paradoxical embolism. Echocardiography showed a thrombus straddling a patent foramen ovale, which was confirmed intraoperatively. An accurate diagnosis and rapid treatment decisions are crucial for preventing patient deterioration in the form of new pulmonary embolisms or stroke.

Compact toroid formation, compression, and acceleration

International Nuclear Information System (INIS)

Degnan, J.H.; Peterkin, R.E. Jr.; Baca, G.P.; Beason, J.D.; Bell, D.E.; Dearborn, M.E.; Dietz, D.; Douglas, M.R.; Englert, S.E.; Englert, T.J.; Hackett, K.E.; Holmes, J.H.; Hussey, T.W.; Kiuttu, G.F.; Lehr, F.M.; Marklin, G.J.; Mullins, B.W.; Price, D.W.; Roderick, N.F.; Ruden, E.L.; Sovinec, C.R.; Turchi, P.J.; Bird, G.; Coffey, S.K.; Seiler, S.W.; Chen, Y.G.; Gale, D.; Graham, J.D.; Scott, M.; Sommars, W.

1993-01-01

Research on forming, compressing, and accelerating milligram-range compact toroids using a meter diameter, two-stage, puffed gas, magnetic field embedded coaxial plasma gun is described. The compact toroids that are studied are similar to spheromaks, but they are threaded by an inner conductor. This research effort, named MARAUDER (Magnetically Accelerated Ring to Achieve Ultra-high Directed Energy and Radiation), is not a magnetic confinement fusion program like most spheromak efforts. Rather, the ultimate goal of the present program is to compress toroids to high mass density and magnetic field intensity, and to accelerate the toroids to high speed. There are a variety of applications for compressed, accelerated toroids including fast opening switches, x-radiation production, radio frequency (rf) compression, as well as charge-neutral ion beam and inertial confinement fusion studies. Experiments performed to date to form and accelerate toroids have been diagnosed with magnetic probe arrays, laser interferometry, time and space resolved optical spectroscopy, and fast photography. Parts of the experiment have been designed by, and experimental results are interpreted with, the help of two-dimensional (2-D), time-dependent magnetohydrodynamic (MHD) numerical simulations. When not driven by a second discharge, the toroids relax to a Woltjer--Taylor equilibrium state that compares favorably to the results of 2-D equilibrium calculations and to 2-D time-dependent MHD simulations. Current, voltage, and magnetic probe data from toroids that are driven by an acceleration discharge are compared to 2-D MHD and to circuit solver/slug model predictions. Results suggest that compact toroids are formed in 7--15 μsec, and can be accelerated intact with material species the same as injected gas species and entrained mass ≥1/2 the injected mass

Investigation of the thrombin-generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days

DEFF Research Database (Denmark)

Johansson, Per Ingemar; Svendsen, M.S.; Salado, J.

2008-01-01

thrombin) and endogenous thrombin potential (ETP; nm thrombin*min) were registered. Clot formation was evaluated by TEG and the R time (min), maxial amplitude (MA; mm), time to maximum thrombus generation (TMG; min) and maximum thrombus generation (MTG; dynes cm(-2) s(-1)) and total thrombus generation...... (TTG; dyne cm(-2)) were registered. RESULTS: Platelets become more procoagulant, evaluated both by TEG and CAT during storage. The reduction in CAT lag time and the ttPeak correlated with a decrease in the TEG R time and TMG (P

Incremental Value of Three-Dimensional Transesophageal Echocardiography over the Two-Dimensional Technique in the Assessment of a Thrombus in Transit through a Patent Foramen Ovale.

Science.gov (United States)

Thind, Munveer; Ahmed, Mustafa I; Gok, Gulay; Joson, Marisa; Elsayed, Mahmoud; Tuck, Benjamin C; Townsley, Matthew M; Klas, Berthold; McGiffin, David C; Nanda, Navin C

2015-05-01

We report a case of a right atrial thrombus traversing a patent foramen ovale into the left atrium, where three-dimensional transesophageal echocardiography provided considerable incremental value over two-dimensional transesophageal echocardiography in its assessment. As well as allowing us to better spatially characterize the thrombus, three-dimensional transesophageal echocardiography provided a more quantitative assessment through estimation of total thrombus burden. © 2015, Wiley Periodicals, Inc.

The Influence of Preoperative Aneurysmal Thrombus Quantity and Distribution on the Development of Type II Endoleaks with Aneurysm Sac Enlargement After EVAR of AAA

Energy Technology Data Exchange (ETDEWEB)

Müller-Wille, R., E-mail: rene.mueller-wille@ukr.de [University Medical Center Regensburg, Department of Radiology (Germany); Güntner, O., E-mail: oliverguentner@yahoo.de [Dr. Neumaier MVZ GmBH Castra Regina Center (Germany); Zeman, F., E-mail: florian.zeman@ukr.de [University Medical Center Regensburg, Center for Clinical Studies (Germany); Dollinger, M., E-mail: Dollinger-M@ukw.de [University Hospital of Würzburg, Department of Diagnostic and Interventional Radiology (Germany); Hälg, C., E-mail: haelg@gmx.ch [Kantonsspital Schaffhausen, Department of Radiology and Nuclear Medicine (Switzerland); Beyer, L. P., E-mail: lukas.beyer@ukr.de [University Medical Center Regensburg, Department of Radiology (Germany); Pfister, K., E-mail: karin.pfister@ukr.de; Kasprzak, P., E-mail: gefaess.chirurgie@ukr.de [University Medical Center Regensburg, Department of Vascular Surgery (Germany); Stroszczynski, C., E-mail: christian.stros@ukr.de; Wohlgemuth, W. A., E-mail: walter.wohlgemuth@ukr.de [University Medical Center Regensburg, Department of Radiology (Germany)

2016-08-15

PurposeTo determine the influence of preoperative aneurysmal thrombus quantity and distribution on the development of type II endoleak with aneurysm sac enlargement after endovascular aneurysm repair (EVAR).Materials and MethodsWe retrospectively analyzed the pre- and postoperatively performed CT scans of 118 patients who had follow-up imaging for at least 1 year after EVAR available. We assessed preoperative thrombus perimeter (T{sub Peri}), diameter (T{sub Dia}), cross-sectional area (T{sub CSA}), and volume (T{sub Vol}). The preoperative thrombus distribution was classified into no thrombus, semilunar-shaped (anterior, right side, left side, posterior) thrombus, and circumferential type thrombus. The number of preoperative patent aortic side branches (ASB) was identified. Endpoint was type II endoleak with aneurysm volume (A{sub Vol}) increase of ≥5 % during follow-up.ResultsDuring follow-up (2 years, range 1–9 years), 17 patients with type II endoleak had significant A{sub Vol} increase. Less preoperative T{sub Peri}, T{sub Dia}, T{sub CSA}, and T{sub Vol} were associated with A{sub Vol} increase. A circumferential thrombus distribution significantly protected against aneurysm enlargement (p = 0.028). The variables with the strongest significance for A{sub Vol} increase were preoperative T{sub Vol}/A{sub Vol} ratio (OR 0.95; p = 0.037) and number of patent ASB (OR 3.52; p < 0.001).ConclusionA low preoperative T{sub Vol}/A{sub Vol} ratio and a high number of patent ASB were associated with aneurysm sac enlargement after EVAR.

Tumor thrombus of inferior vena cava in patients with renal cell carcinoma – clinical and oncological outcome of 50 patients after surgery

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Kocot Arkadius

2012-06-01

Full Text Available Abstract Background To evaluate oncological and clinical outcome in patients with renal cell carcinoma (RCC and tumor thrombus involving inferior vena cava (IVC treated with nephrectomy and thrombectomy. Methods We identified 50 patients with a median age of 65 years, who underwent radical surgical treatment for RCC and tumor thrombus of the IVC between 1997 and 2010. The charts were reviewed for pathological and surgical parameters, as well as complications and oncological outcome. Results The median follow-up was 26 months. In 21 patients (42% distant metastases were already present at the time of surgery. All patients underwent radical nephrectomy, thrombectomy and lymph node dissection through a flank (15 patients/30%, thoracoabdominal (14 patients/28% or midline abdominal approach (21 patients/42%, depending upon surgeon preference and upon the characteristics of tumor and associated thrombus. Extracorporal circulation with cardiopulmonary bypass (CPB was performed in 10 patients (20% with supradiaphragmal thrombus of IVC. Cancer-specific survival for the whole cohort at 5 years was 33.1%. Survival for the patients without distant metastasis at 5 years was 50.7%, whereas survival rate in the metastatic group at 5 years was 7.4%. Median survival of patients with metastatic disease was 16.4 months. On multivariate analysis lymph node invasion, distant metastasis and grading were independent prognostic factors. There was no statistically significant influence of level of the tumor thrombus on survival rate. Indeed, patients with supradiaphragmal tumor thrombus (n = 10 even had a better outcome (overall survival at 5 years of 58.33% than the entire cohort. Conclusions An aggressive surgical approach is the most effective therapeutic option in patients with RCC and any level of tumor thrombus and offers a reasonable longterm survival. Due to good clinical and oncological outcome we prefer the use of CPB with extracorporal

Platelets Drive Thrombus Propagation in a Hematocrit and Glycoprotein VI-Dependent Manner in an In Vitro Venous Thrombosis Model.

Science.gov (United States)

Lehmann, Marcus; Schoeman, Rogier M; Krohl, Patrick J; Wallbank, Alison M; Samaniuk, Joseph R; Jandrot-Perrus, Martine; Neeves, Keith B

2018-05-01

The objective of this study was to measure the role of platelets and red blood cells on thrombus propagation in an in vitro model of venous valvular stasis. A microfluidic model with dimensional similarity to human venous valves consists of a sinus distal to a sudden expansion, where for sufficiently high Reynolds numbers, 2 countercurrent vortices arise because of flow separation. The primary vortex is defined by the points of flow separation and reattachment. A secondary vortex forms in the deepest recess of the valve pocket characterized by low shear rates. An initial fibrin gel formed within the secondary vortex of a tissue factor-coated valve sinus. Platelets accumulated at the interface of the fibrin gel and the primary vortex. Red blood cells at physiological hematocrits were necessary to provide an adequate flux of platelets to support thrombus growth out of the valve sinus. A subpopulation of platelets that adhered to fibrin expose phosphatidylserine. Platelet-dependent thrombus growth was attenuated by inhibition of glycoprotein VI with a blocking Fab fragment or D-dimer. A 3-step process regulated by hemodynamics was necessary for robust thrombus propagation: First, immobilized tissue factor initiates coagulation and fibrin deposition within a low flow niche defined by a secondary vortex in the pocket of a model venous valve. Second, a primary vortex delivers platelets to the fibrin interface in a red blood cell-dependent manner. Third, platelets adhere to fibrin, activate through glycoprotein VI, express phosphatidylserine, and subsequently promote thrombus growth beyond the valve sinus and into the bulk flow. © 2018 American Heart Association, Inc.

Learner-Responsive Instructional Strategies for Adults in Accelerated Classroom Formats: Creating Inclusive Learning Environments

Science.gov (United States)

Gupta, Kalpana

2012-01-01

This study was focused on investigating inclusive learning environments in accelerated classroom formats. Three 8-week sections of an undergraduate course at Regis University were examined. Results from observations and surveys were analyzed to determine the effectiveness and consistency of 13 inclusive strategies derived from Wlodkowski and…

Magnetic resonance venography to assess thrombus resolution with edoxaban monotherapy versus parenteral anticoagulation/warfarin for symptomatic deep vein thrombosis: A multicenter feasibility study.

Science.gov (United States)

Piazza, Gregory; Mani, Venkatesh; Goldhaber, Samuel Z; Grosso, Michael A; Mercuri, Michele; Lanz, Hans J; Schussler, Steven; Hsu, Ching; Chinigo, Amy; Ritchie, Bruce; Nadar, Venkatesh; Cannon, Kevin; Pullman, John; Concha, Mauricio; Schul, Marlin; Fayad, Zahi A

2016-08-01

The feasibility of magnetic resonance venography (MRV) for measuring change in thrombus volume with a novel anticoagulation regimen versus standard anticoagulation in patients with symptomatic deep vein thrombosis (DVT) has not been assessed. Our aim was to study the feasibility of MRV to measure change in thrombus volume in patients with acute symptomatic objectively confirmed proximal DVT in an open-label multicenter trial (edoxaban Thrombus Reduction Imaging Study, eTRIS). We randomized patients in a 2:1 allocation ratio to edoxaban 90 mg/day for 10 days followed by 60 mg/day versus parenteral anticoagulation bridging to warfarin for 3 months. The primary efficacy outcome was a surrogate end point of the relative change in MRV-quantified thrombus volume from baseline to Day 14-21. A total of 85 eligible patients from 26 study sites were randomized to edoxaban monotherapy (n=56) versus parenteral anticoagulation as a 'bridge' to warfarin (n=29). The mean relative change in MRV-quantified thrombus volume from baseline to Day 14-21 was similar in patients treated with edoxaban and parenteral anticoagulation as a 'bridge' to warfarin (-50.1% vs -58.9%; 95% confidence interval of treatment difference, -12.7%, 30.2%). However, thrombus extension was observed in eight patients in the edoxaban monotherapy group and in none in the warfarin group. Rates of recurrent venous thromboembolism (3.6% vs 3.6%, p=0.45) and clinically relevant non-major bleeding (5.4% vs 7.1%, p=0.34) were also similar. No major bleeds occurred in either on-treatment group during the study period. In conclusion, MRV can assess change in thrombus volume in patients with acute DVT randomized to two different anticoagulant regimens.ClinicalTrials.gov IDENTIFIER NCT01662908: INVESTIGATIONAL NEW DRUG IND APPLICATION EDOXABAN IND # 63266. © The Author(s) 2016.

Relationship between Serum Inflammatory Biomarkers and Thrombus Characteristics in Patients with ST Segment Elevation Myocardial Infarction.

Science.gov (United States)

Niccoli, Giampaolo; Menozzi, Alberto; Capodanno, Davide; Trani, Carlo; Sirbu, Vasile; Fineschi, Massimo; Zara, Chiara; Crea, Filippo; Trabattoni, Daniela; Saia, Francesco; Ladich, Elena; Biondi Zoccai, Giuseppe; Attizzani, Guilherme; Guagliumi, Giulio

2017-01-01

To compare angiographic and optical coherence tomography (OCT) data pertinent to thrombi, along with the histologic characteristics of aspirated thrombi in patients presenting with ST elevation myocardial infarction (STEMI) with or without inflammation, as assessed by C-reactive protein (CRP) and myeloperoxidase (MPO). In the OCTAVIA (Optical Coherence Tomography Assessment of Gender Diversity in Primary Angioplasty) study, 140 patients with STEMI referred for primary percutaneous intervention were enrolled. The patients underwent OCT assessment of the culprit vessel, along with blood sampling of CRP and MPO, and histologic analysis of the thrombus. Biomarkers were available for 129 patients, and histology and immunohistochemistry of the thrombi were available for 78 patients. Comparisons were made using the median thresholds of CRP and MPO (2.08 mg/L and 604.124 ng/mL, respectively). There was no correlation between CRP and MPO levels in the whole population (p = 0.685). Patients with high CRP levels had higher thrombus grades and more frequent TIMI flow 0/1 compared with those with low CRP levels (5 [1st quartile 3; 3rd quartile 5] vs. 3.5 mg/L [1; 5], p = 0.007, and 69.3 vs. 48.5%, p = 0.04, respectively). Patients with high MPO levels more commonly had early thrombi than had those with low MPO levels (42.5 vs. 20.0%, p = 0.04). CRP and MPO were not correlated in STEMI patients, possibly reflecting different pathogenic mechanisms, with CRP more related to thrombus burden and MPO to thrombus age. © 2016 S. Karger AG, Basel.

Hepatic vein tumor thrombus as a risk factor for excessive pulmonary deposition of microspheres during TheraSphere therapy for unresectable hepatocellular carcinoma.

Science.gov (United States)

Fleming, Chad J; Andrews, James C; Wiseman, Gregory A; Gansen, Denise N; Roberts, Lewis R

2009-11-01

To evaluate the impact of identifiable hepatic vein tumor thrombus on the ability to safely deliver TheraSphere (yttrium 90-containing glass microspheres) for the treatment of hepatocellular carcinoma (HCC). A retrospective review was performed of 87 patients (71 men, 16 women; mean age, 64.5 years; age range, 25-83 y) referred for TheraSphere therapy for HCC during a 2-year period between April 2005 and May 2007. Evaluation included contrast-enhanced computed tomography or magnetic resonance imaging, selective mesenteric angiography, and radionuclide perfusion scintigraphy to measure the arteriovenous shunting through the tumor. Of the 87 patients, 83 underwent angiography and perfusion scintigraphy; 53 were ultimately treated with 65 glass microsphere infusions. Twelve of 83 were identified as having tumor thrombus in a hepatic vein or extending into the inferior vena cava. The mean lung shunt for the patients with hepatic vein tumor thrombus was 30% (range, 11%-60%), compared with 8.2% (range, 3%-23%) for patients without identifiable tumor thrombus. Two of the 12 patients were treated with reduced doses of glass microspheres, and the remaining 10 were offered alternative therapies. The presence of hepatic vein tumor thrombus is a risk factor for an increased lung shunt that may prohibit delivery of a therapeutic dose of TheraSphere to hepatic tumor.

Extensive tumor thrombus of hepatocellular carcinoma in the entire portal venous system detected on fluorodeoxyglucose positron emission tomography computed tomography

International Nuclear Information System (INIS)

Agrawal, Archi; Purandare, Nilendu; Shah, Sneha; Puranik, Ameya; Rangarajan, Venkatesh

2013-01-01

Detection of thrombus is usually an incidental finding on fluorodeoxyglucose positron emission tomography/computed tomography studies. Nevertheless this is an important finding in terms of disease prognostication and in planning the treatment strategy. We herein report a case of a 50-years-old male, a diagnosed case of hepatocellular carcinoma with extensive hypermetabolic thrombus involving the entire portal venous system. (author)

Ultrasound Detection of Superior Vena Cava Thrombus

Directory of Open Access Journals (Sweden)

Aaron Birch

2014-09-01

Full Text Available Superior vena cava (SVC syndrome is most commonly the insidious result of decreased vascular flow through the SVC due to malignancy, spontaneous thrombus, infections, and iatrogenic etiologies. Clinical suspicion usually leads to computed tomography to confirm the diagnosis. However, when a patient in respiratory distress requires emergent airway management, travel outside the emergency department is not ideal. With the growing implementation of point-of-care ultrasound (POCUS, clinicians may make critical diagnoses rapidly and safely. We present a case of SVC syndrome due to extensive thrombosis of the deep venous system cephalad to the SVC diagnosed by POCUS. [West J Emerg Med. 2014;15(6:715-718

Greenfield filter caval perforation causing an aortic mural thrombus and femoral artery occlusion.

Science.gov (United States)

Chintalapudi, U B; Gutierrez, O H; Azodo, M V

1997-05-01

A 32-year-old woman suffered a right femoral artery embolic occlusion from an abdominal aortic mural thrombus associated with caval perforation by a stainless steel Greenfield Filter. The complication required thrombolytic therapy, surgical revascularization, and long-term anticoagulation.

Guide to LIBXSIF, a Library for Parsing the Extended Standard Input Format of Accelerated Beamlines(LCC-0060)

International Nuclear Information System (INIS)

Tenenbaum, P

2003-01-01

We describe LIBXSIF, a standalone library for parsing the Extended Standard Input Format of accelerator beamlines. Included in the description are: documentation of user commands; full description of permitted accelerator elements and their attributes; the construction of beamline lists; the mechanics of adding LIBXSIF to an existing program; and ''under the hood'' details for users who wish to modify the library or are merely morbidly curious

Preparation and characterization of gadolinium-loaded PLGA particles surface modified with RGDS for the detection of thrombus

Directory of Open Access Journals (Sweden)

Zhang Y

2013-10-01

Full Text Available Yu Zhang,1 Jun Zhou,1 Dajing Guo,1 Meng Ao,2 Yuanyi Zheng,2 Zhigang Wang21Department of Radiology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China; 2Institute of Ultrasound Imaging, Department of Ultrasound, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of ChinaAbstract: Thrombotic disease is a leading cause of death and disability worldwide. The development of magnetic resonance molecular imaging provides potential promise for early disease diagnosis. In this study, we explore the preparation and characterization of gadolinium (Gd-loaded poly (lactic-co-glycolic acid (PLGA particles surface modified with the Arg-Gly-Asp-Ser (RGDS peptide for the detection of thrombus. PLGA was employed as the carrier-delivery system, and a double emulsion solvent-evaporation method (water in oil in water was used to prepare PLGA particles encapsulating the magnetic resonance contrast agent Gd diethylenetriaminepentaacetic acid (DTPA. To synthesize the Gd-PLGA/chitosan (CS-RGDS particles, carbodiimide-mediated amide bond formation was used to graft the RGDS peptide to CS to form a CS-RGDS film that coated the surface of the PLGA particles. Blank PLGA, Gd-PLGA, and Gd-PLGA/CS particles were fabricated using the same water in oil in water method. Our results indicated that the RGDS peptide successfully coated the surface of the Gd-PLGA/CS-RGDS particles. The particles had a regular shape, smooth surface, relatively uniform size, and did not aggregate. The high electron density of the Gd-loaded particles and a translucent film around the particles coated with the CS and CS-RGDS films could be observed by transmission electron microscopy. In vitro experiments demonstrated that the Gd-PLGA/CS-RGDS particles could target thrombi and could be imaged using a clinical magnetic resonance scanner. Compared with the Gd-DTPA solution, the longitudinal relaxation time of

Use of an anti-platelet monoclonal antibody F (ab')2 fragment for imaging thrombus

International Nuclear Information System (INIS)

Loutfi, I.; Stuttle, A.W.J.; Peters, A.M.; George, P.; Lavender, J.P.; Lumley, P.

1990-01-01

Ten patients with suspected thrombus have been studied using 111 In-labelled F (ab')2 fragments of P256, a monoclonal antibody which recognizes an epitope on the platelet membrane glycoprotein IIb/IIIa complex. The F (ab')2 fragment was radiolabelled with 111 In via diethylenetri-aminepentamacetic acid to give a specific activity of up to 190 MBq (5mCi) mg - 1 without impairment of immunoreactivity. In vitro platelet aggregation studies showed that the F (ab')2 fragment caused less platelet aggregation than the whole antibody on a molar ratio and was without significant effect upon the sensitivity of platelets to a range of aggregating agents. Platalets were labelled in ten patients by intravenous injection of approximately 100 μg P256 F (ab')2. Of the ten patients studies, six showed localization of activity consistent with platelet accumulation. Localization was clearly seen when associated with thrombus of the lower limbs (three patients: deep vein thrombosis; one patient: aortofemoral graft), and was apparent although less marked in two other cases, one of aortic aneurysm and one of carotid stenosis. Use of radiolabelled P256 F (ab')2 offers a means of non-invasive detection of thrombus which, from in vitro studies, would appear to have less direct effect of platelet behaviour than the whole antibody. (author). 9 refs. 8 figs. 1 tab

Intermittent, noncyclic dysfunction of a mechanical aortic prosthesis by pannus formation.

Science.gov (United States)

Giroux, Sylvie K; Labinaz, Marino X; Grisoli, Dominique; Klug, Andrew P; Veinot, John P; Burwash, Ian G

2010-01-01

Mechanical aortic prosthesis dysfunction can result from thrombosis or pannus formation. Pannus formation usually restricts systolic excursion of the occluding disk, resulting in progressive stenosis of the aortic prosthesis. Intermittent dysfunction of a mechanical aortic prosthesis is usually ascribed to thrombus formation. We describe an unusual case of intermittent, noncyclic dysfunction of a mechanical aortic prosthesis due to pannus formation in the absence of systolic restriction of disk excursion that presented with intermittent massive aortic regurgitation, severe ischemia, and shock. Pannus formation should be considered as a potential cause of acute intermittent severe aortic regurgitation in a patient with a mechanical aortic prosthesis.

Clinical application of endovascular stent-graft in the treatment of portal stenosis of cancerous thrombus

International Nuclear Information System (INIS)

Jiang Zaibo; Huang Mingsheng; Wang Jing; Li Zhengran; Qian Jiesheng; Guang Shouhai; Zhu Kangshun; Shan Hong; Zhang Xiongjun

2007-01-01

Objective: To explore the approach and early effects of endovascular stent-graft deployment in the treatment of portal stenosis of cancerous thrombus. Methods: Six cases with portal vein stenosis of cancerous thrombus, which caused by primary hepatic carcinoma (5 cases) and cholangiocarcinoma (1 case) and the severity of stenosis showed on contrast enhanced CT were more than 75% or occluded, were performed percutaneous transhepatic or transsplenic portography. FLUENCY TM endovascular stent-graft (10 mm diameter) was placed at the position of stenosis after gastroesophageal varices embolization. Portal pressure was measured pre- and post-deployment. Results: Stents were successfully placed in all patients. The average portal pressure decreased from 50.7 em H 2 O (1 cm H 2 O0.098 kPa) to 41.3 cm H 2 O after endovascular stent-graft deployment. The restenosis were found in 2 cases after one month. Haematemesis and refractory ascites appeared in one case respectively, the other 4 cases showed no significant symptoms above caused by portal hypertension. Conclusion: It is safe and feasible for endovascular stent-graft deployment in the treatment of portal stenosis of cancerous thrombus. Selecting the suitable indications, the symptoms of portal hypertension can be controlled effectively. (authors)

A multimodality vascular imaging phantom of an abdominal aortic aneurysm with a visible thrombus

Energy Technology Data Exchange (ETDEWEB)

Allard, Louise; Chayer, Boris; Qin Zhao [Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Quebec H2L 2W5 (Canada); Soulez, Gilles [Department of Radiology, University of Montreal Hospital (CHUM), Quebec H2L 2M1 (Canada); Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Quebec H3T 1J4 (Canada); Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada); Roy, David [Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada); Cloutier, Guy [Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Quebec H2L 2W5 (Canada); Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Quebec H3T 1J4 (Canada); Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada)

2013-06-15

Purpose: With the continuous development of new stent grafts and implantation techniques, it has now become technically feasible to treat abdominal aortic aneurysms (AAA) with challenging anatomy using endovascular repair with standard, fenestrated, or branched stent-grafts. In vitro experimentations are very useful to improve stent-graft design and conformability or imaging guidance for stent-graft delivery or follow-up. Vascular replicas also help to better understand the limitation of endovascular approaches in challenging anatomy and possibly improve surgical planning or training by practicing high risk clinical procedures in the laboratory to improve outcomes in the operating room. Most AAA phantoms available have a very basic anatomy, which is not representative of the clinical reality. This paper presents a method of fabrication of a realistic AAA phantom with a visible thrombus, as well as some mechanical properties characterizing such phantom. Methods: A realistic AAA geometry replica of a real patient anatomy taken from a multidetector computed tomography (CT) scan was manufactured. To demonstrate the multimodality imaging capability of this new phantom with a thrombus visible in magnetic resonance (MR) angiography, CT angiography (CTA), digital subtraction angiography (DSA), and ultrasound, image acquisitions with all these modalities were performed by using standard clinical protocols. Potential use of this phantom for stent deployment was also tested. A rheometer allowed defining hyperelastic and viscoelastic properties of phantom materials. Results: MR imaging measurements of SNR and CNR values on T1 and T2-weighted sequences and MR angiography indicated reasonable agreement with published values of AAA thrombus and abdominal components in vivo. X-ray absorption also lay within normal ranges of AAA patients and was representative of findings observed on CTA, fluoroscopy, and DSA. Ultrasound propagation speeds for developed materials were also in

A multimodality vascular imaging phantom of an abdominal aortic aneurysm with a visible thrombus

International Nuclear Information System (INIS)

Allard, Louise; Chayer, Boris; Qin Zhao; Soulez, Gilles; Roy, David; Cloutier, Guy

2013-01-01

Purpose: With the continuous development of new stent grafts and implantation techniques, it has now become technically feasible to treat abdominal aortic aneurysms (AAA) with challenging anatomy using endovascular repair with standard, fenestrated, or branched stent-grafts. In vitro experimentations are very useful to improve stent-graft design and conformability or imaging guidance for stent-graft delivery or follow-up. Vascular replicas also help to better understand the limitation of endovascular approaches in challenging anatomy and possibly improve surgical planning or training by practicing high risk clinical procedures in the laboratory to improve outcomes in the operating room. Most AAA phantoms available have a very basic anatomy, which is not representative of the clinical reality. This paper presents a method of fabrication of a realistic AAA phantom with a visible thrombus, as well as some mechanical properties characterizing such phantom. Methods: A realistic AAA geometry replica of a real patient anatomy taken from a multidetector computed tomography (CT) scan was manufactured. To demonstrate the multimodality imaging capability of this new phantom with a thrombus visible in magnetic resonance (MR) angiography, CT angiography (CTA), digital subtraction angiography (DSA), and ultrasound, image acquisitions with all these modalities were performed by using standard clinical protocols. Potential use of this phantom for stent deployment was also tested. A rheometer allowed defining hyperelastic and viscoelastic properties of phantom materials. Results: MR imaging measurements of SNR and CNR values on T1 and T2-weighted sequences and MR angiography indicated reasonable agreement with published values of AAA thrombus and abdominal components in vivo. X-ray absorption also lay within normal ranges of AAA patients and was representative of findings observed on CTA, fluoroscopy, and DSA. Ultrasound propagation speeds for developed materials were also in

Tissue factor levels and the fibrinolytic system in thin and thick intraluminal thrombus and underlying walls of abdominal aortic aneurysms.

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Siennicka, Aldona; Zuchowski, Marta; Kaczmarczyk, Mariusz; Cnotliwy, Miłosław; Clark, Jeremy Simon; Jastrzębska, Maria

2018-03-20

The hemostatic system cooperates with proteolytic degradation in processes allowing abdominal aortic aneurysm (AAA) formation. In previous studies, it has been suggested that aneurysm rupture depends on intraluminal thrombus (ILT) thickness, which varies across each individual aneurysm. We hypothesized that hemostatic components differentially accumulate in AAA tissue in relation to ILT thickness. Thick (A1) and thin (B1) segments of ILTs and aneurysm wall sections A (adjacent to A1) and B (adjacent to B1) from one aneurysm sac were taken from 35 patients undergoing elective repair. Factor levels were measured using enzyme-linked immunosorbent assay of protein extract. Tissue factor (TF) activities were significantly higher in thinner segments of AAA (B1 vs A1, P = .003; B vs A, P thick thrombus-covered wall segments (A) than in B, A1, and B1 (P = .015, P thick ILT (P = .021) and thick ILT (A1; P thick ILT (A1). However, no correlations were found at B sites, except for a correlation between plasmin and TF activities (r = 0.55; P = .004). These results suggest that higher TF activities are present in thinner AAA regions. These parameters and local fibrinolysis may be part of the processes leading to destruction of the aneurysm wall. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Indium-111 platelet scintigraphy and two-dimensional echocardiography for detection of left ventricular thrombus: influence of clot size and age

International Nuclear Information System (INIS)

Seabold, J.E.; Schroeder, E.C.; Conrad, G.R.

1987-01-01

Two-dimensional echocardiography and indium-111 platelet scintigraphy were performed on 50 dogs to determine the influence of clot age and size on the detection of experimentally induced left ventricular mural thrombus. Thrombus was induced by apical infarction and injection of a sclerosing agent and thrombin. The animals were classified into four groups according to the time of indium-111 platelet injection after thrombus induction: Group I (17 dogs, 1/2 hour after induction; 3 dogs, before induction), Group II (12 dogs, 24 hours after induction) and Group III (12 dogs, 1 week after induction). In Group IV (six control dogs) apical infarction was produced, but thrombin was not injected; indium-111 platelets were injected 1/2 to 1 hour after infarction. The dogs were studied by indium-111 platelet scintigraphy and by two-dimensional echocardiography 1/2 to 5 hours (Group I) and 1 to 5 and up to 72 hours (Groups II to IV) after platelet administration and before death was induced. Two-dimensional echocardiography showed the best overall sensitivity for detection of acute thrombus (97%; 29 of 30). The sensitivity of indium-111 platelet scintigraphy was 86% (18 of 21) for clots greater than or equal to 0.08 ml in size, and 67% (20 of 30) for detection of all clots. Thrombus did not form in 14 dogs of Groups I to III and in 6 of 6 control dogs. The specificity of scintigraphy was 100% (20 of 20) compared with 80% (16 of 20) for echocardiography. Echocardiography was more sensitive than scintigraphy for detecting very small clots in this experimental model

A Behcet’s Disease Patient with Right Ventricular Thrombus, Pulmonary Artery Aneurysms, and Deep Vein Thrombosis Complicating Recurrent Pulmonary Thromboembolism

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Selvi Aşker

2013-01-01

Full Text Available Intracardiac thrombus, pulmonary artery aneurysms, deep vein thrombosis, and pulmonary thromboembolism are rarely seen symptoms of Behcet’s disease. A 20-year-old female patient was admitted for complaints of cough, fever, palpitations, and chest pain. On the dynamic thorax computed tomograms (CT obtained because of significantly enlarged hilar structures seen on chest radiograms, aneurysmal dilatation of the pulmonary artery segments bilaterally, chronic thrombus with collapse, and consolidation substances compatible with pulmonary embolism involving both lower lobes have been observed. It is learned that, four years ago, the patient had been diagnosed with Behcet’s disease and received colchicine treatment but not regularly. The patient was hospitalized. On the transthoracic echocardiogram, a thrombosis with a dimension of 4.2 × 1.6 cm was recognized in the right ventricle. On abdomen CT, aneurysmal iliac veins and deep vein thrombus on Doppler ultrasonograms were diagnosed. At the controls after three months of immunosuppressive and anticoagulant therapies, some clinical and radiological improvements were recognized. The patient suspended the treatment for a month and the thrombus recurred. We present our case in order to show the effectiveness of immunosuppressive and anticoagulant therapies and rarely seen pulmonary thromboembolism in recurrent Behcet’s disease.

Radiopharmaceuticals for thrombus detection

International Nuclear Information System (INIS)

Knight, L.C.

1990-01-01

Most of the components of the thrombotic and fibrinolytic systems have at some time been evaluated as a means of carrying a radiolabel specifically to thrombi, although very few have been promising enough to emerge from investigational status to routine clinical use. New approaches are being explored, including improved methods of labeling platelets, chemically modified forms of previously tested plasma proteins, and new biomolecules, including monoclonal antibodies specific for fibrin and platelets. The current goal is to find one or more radiotracers that bind specifically and rapidly to thrombi, and that also have a rapid blood disappearance rate, permitting a clear diagnosis within a few hours after injection. Because this test may be needed to assess the course of therapy in an anticoagulated patient, the ideal radiopharmaceutical should be able to locate thrombi without interference by anticoagulants. Until a suitable thrombus-specific radiopharmaceutical becomes generally available, many hospitals will continue to attempt to make a diagnosis with nonspecific radiopharmaceuticals that can at best provide blood pool images to indicate filling defects. Several of the new approaches seem likely to provide the radiopharmaceutical sought, although clinical trials are at an early stage.137 references

TIME-DEPENDENT ELECTRON ACCELERATION IN BLAZAR TRANSIENTS: X-RAY TIME LAGS AND SPECTRAL FORMATION

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Lewis, Tiffany R.; Becker, Peter A. [Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030-4444 (United States); Finke, Justin D., E-mail: pbecker@gmu.edu, E-mail: tlewis13@gmu.edu, E-mail: justin.finke@nrl.navy.mil [U.S. Naval Research Laboratory, Code 7653, 4555 Overlook Avenue SW, Washington, DC 20375-5352 (United States)

2016-06-20

Electromagnetic radiation from blazar jets often displays strong variability, extending from radio to γ -ray frequencies. In a few cases, this variability has been characterized using Fourier time lags, such as those detected in the X-rays from Mrk 421 using Beppo SAX. The lack of a theoretical framework to interpret the data has motivated us to develop a new model for the formation of the X-ray spectrum and the time lags in blazar jets based on a transport equation including terms describing stochastic Fermi acceleration, synchrotron losses, shock acceleration, adiabatic expansion, and spatial diffusion. We derive the exact solution for the Fourier transform of the electron distribution and use it to compute the Fourier transform of the synchrotron radiation spectrum and the associated X-ray time lags. The same theoretical framework is also used to compute the peak flare X-ray spectrum, assuming that a steady-state electron distribution is achieved during the peak of the flare. The model parameters are constrained by comparing the theoretical predictions with the observational data for Mrk 421. The resulting integrated model yields, for the first time, a complete first-principles physical explanation for both the formation of the observed time lags and the shape of the peak flare X-ray spectrum. It also yields direct estimates of the strength of the shock and the stochastic magnetohydrodynamical wave acceleration components in the Mrk 421 jet.

A novel approach for assessing the progression of deep venous thrombosis by area of venous thrombus in ultrasonic elastography.

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Wang, Chao; Wang, Lei; Zhang, Yuhui; Chen, Ming

2014-04-01

Exact age determination of deep venous thrombosis (DVT) is important for an appropriate treatment. The purpose of this present study is to assess the age of acute DVT with the area of venous thrombi in elasticity imaging during the thrombosis procession. The thrombus area is obtained from a specially designed program. It was applied to clot specimens induced in human great saphenous (n = 15) at selected time points following the initiation of thrombosis. The relative mean proportion of blood clots was 50.01% ± 12.44% at day 1; 69.94% ± 8.19% at day 3; 81.93% ± 6.15% at day 6; and 92.37% ± 4.06% at day 9. The results indicated that the thrombus area increased significantly over time, while the normalized strain values inside the thrombus changed only a little. The pathological analyses also showed the same results. Therefore, we conclude that the area of venous thrombi in elasticity imaging may be a novel function for acute DVT staging.

Intravascular ultrasound and angiographic demonstration of left main stem thrombus-high-risk presentation in a young adult with anabolic steroid abuse.

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Garg, Pankaj; Davis, Gershan; Wilson, John Ian; Sivananthan, Mohan

2010-01-01

We present a case of acute myocardial infarction in a young adult with a history of anabolic steroid abuse. On diagnostic coronary angiography and intravascular ultrasound, he was found to have a distal left main stem thrombus extending into the proximal left anterior descending artery and a large intermediate vessel. As he was hemodynamically stable and pain-free, he was managed conservatively with triple antiplatelet therapy (aspirin, clopidogrel, and abciximab). This was also to avoid the risk of 'wiring the vessel,' especially if there was underlying dissection. Repeat angiography a few weeks later showed complete thrombus resolution. This is the first reported case of extensive left main stem thrombus in a young patient with anabolic steroid abuse. Management of such cases is not straightforward and our case highlights one approach to both diagnosis and treatment.

A Novel Technique for Endovascular Removal of Large Volume Right Atrial Tumor Thrombus

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Nickel, Barbara, E-mail: nickel.ba@gmail.com [US Teleradiology and Quantum Medical Radiology Group (United States); McClure, Timothy, E-mail: tmcclure@gmail.com; Moriarty, John, E-mail: jmoriarty@mednet.ucla.edu [UCLA Medical Center, Department of Interventional Radiology (United States)

2015-08-15

Venous thromboembolic disease is a significant cause of morbidity and mortality, particularly in the setting of large volume pulmonary embolism. Thrombolytic therapy has been shown to be a successful treatment modality; however, its use somewhat limited due to the risk of hemorrhage and potential for distal embolization in the setting of large mobile thrombi. In patients where either thrombolysis is contraindicated or unsuccessful, and conventional therapies prove inadequate, surgical thrombectomy may be considered. We present a case of percutaneous endovascular extraction of a large mobile mass extending from the inferior vena cava into the right atrium using the Angiovac device, a venovenous bypass system designed for high-volume aspiration of undesired endovascular material. Standard endovascular methods for removal of cancer-associated thrombus, such as catheter-directed lysis, maceration, and exclusion, may prove inadequate in the setting of underlying tumor thrombus. Where conventional endovascular methods either fail or are unsuitable, endovascular thrombectomy with the Angiovac device may be a useful and safe minimally invasive alternative to open resection.

A Novel Technique for Endovascular Removal of Large Volume Right Atrial Tumor Thrombus

International Nuclear Information System (INIS)

Nickel, Barbara; McClure, Timothy; Moriarty, John

2015-01-01

Venous thromboembolic disease is a significant cause of morbidity and mortality, particularly in the setting of large volume pulmonary embolism. Thrombolytic therapy has been shown to be a successful treatment modality; however, its use somewhat limited due to the risk of hemorrhage and potential for distal embolization in the setting of large mobile thrombi. In patients where either thrombolysis is contraindicated or unsuccessful, and conventional therapies prove inadequate, surgical thrombectomy may be considered. We present a case of percutaneous endovascular extraction of a large mobile mass extending from the inferior vena cava into the right atrium using the Angiovac device, a venovenous bypass system designed for high-volume aspiration of undesired endovascular material. Standard endovascular methods for removal of cancer-associated thrombus, such as catheter-directed lysis, maceration, and exclusion, may prove inadequate in the setting of underlying tumor thrombus. Where conventional endovascular methods either fail or are unsuitable, endovascular thrombectomy with the Angiovac device may be a useful and safe minimally invasive alternative to open resection

Organizing Thrombus Mimicking a Cardiac Tumor Located at the Mitral-Aortic Intervalvular Fibrosa

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Ji Seong Lee

2016-02-01

Full Text Available Thrombosis at the left ventricular outflow tract occurs without any detectable heart disease or predisposing factors only extremely rarely. A 48-year-old male visited Konkuk University Medical Center with loss of consciousness one month prior to presentation. Before he visited our hospital, he had been diagnosed with a cardiac tumor, which was located between the left atrium and posterior aortic root, and which was adjacent to both the aortic and mitral valves. Cardiac transplantation was recommended at the other hospital because of the high risk of cardiac dysfunction induced by both aortic and mitral valvular dysfunction after surgical resection. Based on preoperative transthoracic echocardiography, cardiac computed tomography, cardiac magnetic resonance imaging, and intraoperative transesophageal echocardiography, we considered it to be a benign tumor. Complete resection was achieved and the pathology confirmed organizing thrombus. We report a case of organizing thrombus mimicking a cardiac tumor, which was located at the mitral-aortic intervalvular fibrosa of the left ventricular outflow tract without any heart disease.

Short-Term Anticoagulant Therapy and Thrombus Location Are Independent Risk Factors for Delayed Recanalization of Deep Vein Thrombosis.

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Zhang, Chuanlin; Fu, Qining; Zhao, Yu; Mu, Shaoyu; Liu, Liping

2016-01-21

Prompt recanalization of the vein containing the thrombus is an important goal during the initial treatment of DVT, and risk factors for delayed recanalization in patients with deep vein thrombosis (DVT) in the lower extremities need to be determined. A total of 174 patients with DVT in lower extremities were recruited from June 2014 to March 2015 at our hospital. Duplex ultrasound scanning was conducted for all patients at 1 and 6 months after baseline evaluation. We divided the patients into recanalization and non-recanalization groups and analyzed risk factors for delayed recanalization. The univariate analysis revealed that an oral anticoagulant time of less than 3 months and venous thrombus location were risk factors for delayed recanalization (P0.05). The multivariate analysis showed that patients with an anticoagulant time of less than 3 months had a lower incidence of recanalization than those with an anticoagulant time of more than 3 months (OR=2.358, Pvenous thrombus location are independent risk factors for delayed recanalization of DVT in the lower extremities.

Left Ventricular Thrombus as a Complication of Clozapine-Induced Cardiomyopathy: A Case Report and Brief Literature Review.

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Malik, Shahbaz A; Malik, Sarah; Dowsley, Taylor F; Singh, Balwinder

2015-01-01

A 48-year-old male with history of schizoaffective disorder on clozapine presented with chest pain, dyspnea, and new left bundle branch block. He underwent coronary angiography, which revealed no atherosclerosis. The patient's workup was unrevealing for a cause for the cardiomyopathy and thus it was thought that clozapine was the offending agent. The patient was taken off clozapine and started on guideline directed heart failure therapy. During the course of hospitalization, he was also discovered to have a left ventricular (LV) thrombus for which he received anticoagulation. To our knowledge, this is the first case report of clozapine-induced cardiomyopathy complicated by a LV thrombus.

Left Ventricular Thrombus as a Complication of Clozapine-Induced Cardiomyopathy: A Case Report and Brief Literature Review

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Shahbaz A. Malik

2015-01-01

Full Text Available A 48-year-old male with history of schizoaffective disorder on clozapine presented with chest pain, dyspnea, and new left bundle branch block. He underwent coronary angiography, which revealed no atherosclerosis. The patient’s workup was unrevealing for a cause for the cardiomyopathy and thus it was thought that clozapine was the offending agent. The patient was taken off clozapine and started on guideline directed heart failure therapy. During the course of hospitalization, he was also discovered to have a left ventricular (LV thrombus for which he received anticoagulation. To our knowledge, this is the first case report of clozapine-induced cardiomyopathy complicated by a LV thrombus.

Imaging of pannus formation in patients with mechanical heart valves.

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Gündüz, Sabahattin; Özkan, Mehmet; Yesin, Mahmut

2015-11-26

Patient-prosthesis mismatch (PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography (MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients.

Late thrombosis of a mitral bioprosthetic valve with associated massive left atrial thrombus

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Preetham R Muskula

2017-04-01

Full Text Available An 84-year-old man presented 5 years after bioprosthetic mitral valve replacement with three months of worsening dyspnea on exertion. A new mitral stenosis murmur was noted on physical examination, and an electrocardiogram revealed newly recognized atrial fibrillation. Severe mitral stenosis (mean gradient = 13 mmHg was confirmed by transthoracic echocardiography. Transesophageal echocardiography revealed markedly thickened mitral bioprosthetic leaflets with limited mobility, and a massive left atrial thrombus (>4 cm in diameter (Fig. 1A, B, C, D and Videos 1, 2, 3 and 4. Intravenous heparin was initiated, and 5 days later, he was taken to the operating room for planned redo mitral valve replacement and left atrial thrombus extraction. Intraoperative transesophageal echocardiography revealed near-complete resolution of the bioprosthetic leaflet thickening, and a mean mitral gradient of only 3 mmHg (Fig. 2A, B, C and Videos 5, 6 and 7. The patient underwent resection of the massive left atrial thrombus (Fig. 2D but did not require redo mitral valve replacement. He was initiated on heparin (and transitioned to warfarin early in the post-operative period, with complete resolution of dyspnea on exertion at 3-month follow-up. Bioprosthetic valve thrombosis is increasingly recognized as a cause of early prosthetic valve dysfunction (1, 2. This case illustrates that bioprosthetic valve thrombosis may occur years after valve replacement; therefore, any deterioration in a patient’s clinical status (new-onset dyspnea, heart failure or atrial fibrillation warrants a thorough evaluation of the bioprosthetic valve with transesophageal echocardiography. In this case, initiation of anticoagulation obviated the need for redo mitral valve replacement.

A floating right heart thrombus in transit across tricuspid valve causing an endocardial friction rub

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Babu Kanjirakadavath

2013-07-01

Full Text Available We report a 42-year-old lady on combined oral contraceptive pills with deep venous thrombosis and mild pulmonary embolism, who developed shock, while being treated with heparin. On auscultation, there was an unexpected loud, superficial, squeaky, triphasic friction rub over the left lower parasternal area. Simultaneous echocardiogram revealed a large serpiginous, freely floating mass in right atrium, prolapsing freely to right ventricular inlet across the tricuspid valve. The endocardial friction rub persisted for about 24 h as long as the thrombus was intracardiac and disappeared when the thrombus disappeared from right heart, occluding the proximal left pulmonary artery. She died due to shock awaiting surgery. We highlight that such a rub in a patient with deep venous thrombosis, though rare, may be an important clue to impending pulmonary embolism.

Association of the route of blood flow channel through an intraluminal thrombus with the abdominal aortic aneurysm rupture in imaging diagnostics

International Nuclear Information System (INIS)

Wiernicki, I.; Gutowski, P.; Kownacki, L.; Polanowski, L.; Gorecka-Szyld, B.; Cyrylowski, L.

2004-01-01

The location of the abdominal aortic aneurysm (AAA) rupture probably influences the patient's morbidity and mortality. No reliable predictors for time and site of the rupture have been found to date. An opinion that intraluminal, parietal thrombus (PT) may play a protective role against the rupture predominates in recent reports. The aim of our study was to evaluate a route of blood flow channel (BFC) through intraluminal PT in AAA. In this prospective study, the thrombus morphology was evaluated in 103 patients with AAA, divided into three groups according to the aneurysm size: group 1 - patients with AAA 30 - 39 mm in maximal diameter, group 2: 40 - 49 mm, and group 3: more than 49 mm. All AAAs were examined with Doppler ultrasound, computed tomography, and magnetic resonance imaging. Anterior, medial, and posterior BFC was defined on the basis of calculated ratio of anterior wall PT thickness to posterior wall PT thickness. Anterior BFC predominates in AAA in group 1 - 39%, while its frequency in group 3 was 21%. Posterior BFC was significantly more frequent in group 3 - 67% than in group 1 - 24%. Both differences were statistically significant (p = 0.03). PT thickness increases in direct proportion to the size of AAA, and with this increase BFC in the thrombus most frequently shifts backward. A lack of PT or its trace may indicate a site of potential rupture of the weakened wall. Patients with AAA and a parietal route of BFC in the thrombus are of higher risk of rupture despite small aneurysm size. In qualification for surgery, the morphology of the thrombus should be considered, in addition to the maximal diameter of AAA. (author)

Synergistic effect of signaling from receptors of soluble platelet agonists and outside-in signaling in formation of a stable fibrinogen-integrin αIIbβ3-actin cytoskeleton complex.

Science.gov (United States)

Budnik, Ivan; Shenkman, Boris; Savion, Naphtali

2015-01-01

Thrombus formation in the injured vessel wall is a highly complex process involving various blood-born components that go through specific temporal and spatial changes as observed by intravital videomicroscopy. Platelets bind transiently to the developing thrombus and may either become stably incorporated into or disengage from the thrombus. The aim of the present study was to reveal the processes involved in the formation of a stable thrombus. Platelet-rich plasma and washed platelets were studied by the aggregometer. The aggregate stability was challenged by eptifibatide. Platelet Triton-insoluble fraction was prepared and the actin and αIIb content in the cytoskeleton was analyzed by western blot. Maximal actin polymerization is achieved 1min after platelet activation while maximal αIIbβ3-actin cytoskeleton association requires 5 to 10min of activation and fibrinogen-mediated platelet-to-platelet bridging. Thus, actin polymerization is dependent on platelet activation and requires neither αIIbβ3 integrin occupation nor platelet aggregation. Formation of a stable aggregate requires platelet activation for more than 1min, complete increase in actin cytoskeleton fraction and partial association of αIIbβ3 with the actin cytoskeleton. However, direct αIIbβ3 activation is not sufficient for cytoskeleton complex formation. Thus, stable αIIbβ3-fibrinogen interaction, representing stable aggregate, is achieved after more than 1min agonist activation, involving inside-out and outside-in signaling but not after direct integrin activation, involving only outside-in signaling. Formation of a stable fibrinogen-αIIbβ3-actin cytoskeleton complex is the result of the combined effect of platelet stimulation by soluble agonists, activation of αIIbβ3, fibrinogen binding and platelet-to-platelet bridging. Copyright © 2014 Elsevier Ltd. All rights reserved.

Accelerated healing of cardiovascular textiles promoted by an RGD peptide.

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Tweden, K S; Harasaki, H; Jones, M; Blevitt, J M; Craig, W S; Pierschbacher, M; Helmus, M N

1995-07-01

Polytetrafluoroethylene (PTFE) and polyethylene terephthalate (Dacron polyester) fabrics are used extensively in cardiovascular devices, e.g. heart valve sewing cuffs and vascular prostheses. While devices containing these fabrics are generally successful, it is recognized that fabrics cause complications prior to tissue ingrowth due to their thrombogenic nature. A surface active synthetic peptide, called PepTite Coating (PepTite), which was modeled after the cell attachment domain of human fibronectin has been marketed as a biocompatible coating. This peptide stimulates cell attachment through the arginine-glycine-aspartic acid (RGD) sequence. Modification of medical implants with PepTite has been shown to promote ingrowth of surrounding cells into the material leading to better tissue integration, reduced inflammation and reduced fibrotic encapsulation. In this study, polyester and PTFE textiles were modified with PepTite. The effectiveness of this coating in enhancing wound healing was investigated in a simple vascular and cardiac valve model. Our results indicate that the RGD-containing peptide, PepTite, promoted the formation of an endothelial-like cell layer on both polyester and PTFE vascular patches in the dog model. PepTite was also found to promote the formation of a significantly thinner neointima (pannus) on polyester as compared to that on its uncoated control. These results were corroborated in the cardiac valve model in which a greater amount of thin pannus and less thrombus were seen on coated polyester sewing cuffs than on control uncoated cuffs. This research shows the promising tissue response to RGD coated textiles and the potential role of this peptide in material passivation via accelerated healing.

The blood flow channel index as novel predictor of abdominal aortic aneurysm impending rupture based on the intraluminal thrombus angio-CT study

International Nuclear Information System (INIS)

Wiernicki, Ireneusz; Szumilowicz, Pawel; Kazimierczak, Arkadiusz; Falkowski, Aleksander; Rutkowski, Donald; Gutowski, Piotr

2015-01-01

Objective: In this study the hypothesis that the thickness of the thinnest part of the thrombus, combined with bleeding into the intraluminal thrombus (ILT), is associated with a possible higher risk of abdominal aortic aneurysm (AAA) rupture was investigated, independently of aneurysm diameter, by using angio-CT. This article describes blood flow channel index based on the CT imaging findings that may help identify impending rupture prior to complete rupture. Methods: Computed tomographic images of 310 hospitalized patients with infrarenal AAA, were collected over a three-year period. They were divided into two main groups: 125 with bleeding into the ILT and control group 185 without the presence of blood in the thrombus. Patients were also analyzed in subgroups with ruptured, symptomatic and asymptomatic AAAs. A blood flow channel index was formulated as: maximal/minimal thickness ratio of thrombus from the same CT scan. Results: In dissected ILT group blood flow channel index was over a twofold higher than in group with intact ILT (19.0 [1.2–89.3] vs. (9.7 [1.3–38.9]; p < 0.001), respectively. Median thickness at the thinnest part of the ILT in dissected thrombus group was lower (1.3 mm [0.3–16.0]) than in group with intact ILT (1.7 mm [0.2–23.4]; p < 0.003). Conclusion: An association between a high blood flow channel index and bleeding into the ILT based on angio-CT study was demonstrated, and can suggest the aneurysm propensity for rupture

The blood flow channel index as novel predictor of abdominal aortic aneurysm impending rupture based on the intraluminal thrombus angio-CT study

Energy Technology Data Exchange (ETDEWEB)

Wiernicki, Ireneusz, E-mail: irekwie@wp.eu [Department of Vascular Surgery and Angiology, Pomeranian Medical University, Szczecin (Poland); Szumilowicz, Pawel; Kazimierczak, Arkadiusz [Department of Vascular Surgery and Angiology, Pomeranian Medical University, Szczecin (Poland); Falkowski, Aleksander; Rutkowski, Donald [Department of Interventional Radiology, Pomeranian Medical University, Szczecin (Poland); Gutowski, Piotr [Department of Vascular Surgery and Angiology, Pomeranian Medical University, Szczecin (Poland)

2015-04-15

Objective: In this study the hypothesis that the thickness of the thinnest part of the thrombus, combined with bleeding into the intraluminal thrombus (ILT), is associated with a possible higher risk of abdominal aortic aneurysm (AAA) rupture was investigated, independently of aneurysm diameter, by using angio-CT. This article describes blood flow channel index based on the CT imaging findings that may help identify impending rupture prior to complete rupture. Methods: Computed tomographic images of 310 hospitalized patients with infrarenal AAA, were collected over a three-year period. They were divided into two main groups: 125 with bleeding into the ILT and control group 185 without the presence of blood in the thrombus. Patients were also analyzed in subgroups with ruptured, symptomatic and asymptomatic AAAs. A blood flow channel index was formulated as: maximal/minimal thickness ratio of thrombus from the same CT scan. Results: In dissected ILT group blood flow channel index was over a twofold higher than in group with intact ILT (19.0 [1.2–89.3] vs. (9.7 [1.3–38.9]; p < 0.001), respectively. Median thickness at the thinnest part of the ILT in dissected thrombus group was lower (1.3 mm [0.3–16.0]) than in group with intact ILT (1.7 mm [0.2–23.4]; p < 0.003). Conclusion: An association between a high blood flow channel index and bleeding into the ILT based on angio-CT study was demonstrated, and can suggest the aneurysm propensity for rupture.

Thrombus imaging in a primate model with antibodies specific for an external membrane protein of activated platelets

International Nuclear Information System (INIS)

Palabrica, T.M.; Furie, B.C.; Konstam, M.A.; Aronovitz, M.J.; Connolly, R.; Brockway, B.A.; Ramberg, K.L.; Furie, B.

1989-01-01

The activated platelet is a potential target for the localization of thrombi in vivo since, after stimulation and secretion of granule contents, activated platelets are concentrated at sites of blood clot formation. In this study, we used antibodies specific for a membrane protein of activated platelets to detect experimental thrombi in an animal model. PADGEM (platelet activation-dependent granule-external membrane protein), a platelet alpha-granule membrane protein, is translocated to the plasma membrane during platelet activation and granule secretion. Since PADGEM is internal in unstimulated platelets, polyclonal anti-PADGEM and monoclonal KC4 antibodies do not bind to circulating resting platelets but do interact with activated platelets. Dacron graft material incubated with radiolabeled KC4 or anti-PADGEM antibodies in the presence of thrombin-activated platelet-rich plasma bound most of the antibody. Imaging experiments with 123I-labeled anti-PADGEM in baboons with an external arterial-venous Dacron shunt revealed rapid uptake in the thrombus induced by the Dacron graft; control experiments with 123I-labeled nonimmune IgG exhibited minimal uptake. Deep venous thrombi, formed by using percutaneous balloon catheters to stop blood flow in the femoral vein of baboons, were visualized with 123I-labeled anti-PADGEM. Thrombi were discernible against blood pool background activity without subtraction techniques within 1 hr. No target enhancement was seen with 123I-labeled nonimmune IgG. 123I-labeled anti-PADGEM cleared the blood pool with an initial half-disappearance time of 6 min and did not interfere with hemostasis. These results indicate that radioimmunoscintigraphy with anti-PADGEM antibodies can visualize thrombi in baboon models and is a promising technique for clinical thrombus detection in humans

Elderly female with acute abdominal pain presenting with Superior Mesenteric Artery Thrombus

Directory of Open Access Journals (Sweden)

Sassan Ghassemzadeh, MD

2018-04-01

Full Text Available History of present illness: An 80-year-old female with history of hypertension and atrial fibrillation, presented with sudden onset of abdominal pain after eating at a restaurant. The patient denied any fever, vomiting or diarrhea. She admitted to being noncompliant with medications including warfarin. Initial vital signs were within normal limits. On exam, the patient was very uncomfortable and could not lay still in bed, even after multiple doses of intravenous narcotic pain medications. The patient had generalized abdominal tenderness without rebound or guarding. Labs revealed a white-blood-cell count of 13.8, lactic acid of 3.6, and international normalized ratio (INR of 1.1, with normal renal function. Significant findings: Computed tomography (CT angiogram of the abdomen and pelvis revealed a superior mesenteric artery (SMA thrombosis 5 cm from the origin off of the abdominal aorta. As seen in the sagittal view, there does not appear to be any contrast 5 cm past the origin of the SMA. On the axial views, you can trace the SMA until the point that there is no longer any contrast visible which indicates the start of the thrombus. The SMA does not appear to be reconstituted. There was normal flow to the celiac artery. (See annotated images. Discussion: This case involves a classic presentation of acute mesenteric ischemia, which is defined as the sudden onset of abdominal pain due to small intestinal hypo-perfusion secondary to reduction or complete occlusion of arterial blood flow to the intestines. The most common artery affected is the SMA. The main two reasons for this phenomenon are either due to an arterial embolus or from arterial thrombus from underlying atherosclerosis. The ratio of superior mesenteric embolus to thrombus has been shown to be 1.4:1.1 Embolism to the mesenteric arteries is most frequently from a thrombus that breaks off from the left atrium, left ventricle, or proximal aorta, as in this case from underlying atrial

Splenectomy after partial hepatectomy accelerates liver regeneration in mice by promoting tight junction formation via polarity protein Par 3-aPKC.

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Liu, Guoxing; Xie, Chengzhi; Fang, Yu; Qian, Ke; Liu, Qiang; Liu, Gao; Cao, Zhenyu; Du, Huihui; Fu, Jie; Xu, Xundi

2018-01-01

Several experimental studies have demonstrated that removal of the spleen accelerates liver regeneration after partial hepatectomy. While the mechanism of splenectomy promotes liver regeneration by the improvement of the formation of tight junction and the establishment of hepatocyte polarity is still unknown. We analyzed the cytokines, genes and proteins expression between 70% partial hepatectomy mice (PHx) and simultaneous 70% partial hepatectomy and splenectomy mice (PHs) at predetermined timed points. Compared with the PHx group mice, splenectomy accelerated hepatocyte proliferation in PHs group. The expression of Zonula occludens-1 (ZO-1) indicated that splenectomy promotes the formation of tight junction during liver regeneration. TNF-α, IL-6, HGF, TSP-1 and TGF-β1 were essential factors for the formation of tight junction and the establishment of hepatocytes polarity in liver regeneration. After splenectomy, Partitioning defective 3 homolog (Par 3) and atypical protein kinase C (aPKC) regulate hepatocyte localization and junctional structures in regeneration liver. Our data suggest that the time course expression of TNF-α, IL-6, HGF, TSP-1, and TGF-β1 and the change of platelets take part in liver regeneration. Combination with splenectomy accelerates liver regeneration by improvement of the tight junction formation which may help to establish hepatocyte polarity via Par 3-aPKC. This may provide a clue for us that splenectomy could accelerate liver regeneration after partial hepatectomy of hepatocellular carcinoma and living donor liver transplantation. Copyright © 2017 Elsevier Inc. All rights reserved.

Blood flow and coherent vortices in the normal and aneurysmatic aortas: a fluid dynamical approach to intra-luminal thrombus formation.

Science.gov (United States)

Biasetti, Jacopo; Hussain, Fazle; Gasser, T Christian

2011-10-07

Abdominal aortic aneurysms (AAAs) are frequently characterized by the development of an intra-luminal thrombus (ILT), which is known to have multiple biochemical and biomechanical implications. Development of the ILT is not well understood, and shear-stress-triggered activation of platelets could be the first step in its evolution. Vortical structures (VSs) in the flow affect platelet dynamics, which motivated the present study of a possible correlation between VS and ILT formation in AAAs. VSs educed by the λ(2)-method using computational fluid dynamics simulations of the backward-facing step problem, normal aorta, fusiform AAA and saccular AAA were investigated. Patient-specific luminal geometries were reconstructed from computed tomography scans, and Newtonian and Carreau-Yasuda models were used to capture salient rheological features of blood flow. Particularly in complex flow domains, results depended on the constitutive model. VSs developed all along the normal aorta, showing that a clear correlation between VSs and high wall shear stress (WSS) existed, and that VSs started to break up during late systole. In contrast, in the fusiform AAA, large VSs developed at sites of tortuous geometry and high WSS, occupying the entire lumen, and lasting over the entire cardiac cycle. Downward motion of VSs in the AAA was in the range of a few centimetres per cardiac cycle, and with a VS burst at that location, the release (from VSs) of shear-stress-activated platelets and their deposition to the wall was within the lower part of the diseased artery, i.e. where the thickest ILT layer is typically observed. In the saccular AAA, only one VS was found near the healthy portion of the aorta, while in the aneurysmatic bulge, no VSs occurred. We present a fluid-dynamics-motivated mechanism for platelet activation, convection and deposition in AAAs that has the potential of improving our current understanding of the pathophysiology of fluid-driven ILT growth.

Dysfunctional nitric oxide signalling increases risk of myocardial infarction.

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Erdmann, Jeanette; Stark, Klaus; Esslinger, Ulrike B; Rumpf, Philipp Moritz; Koesling, Doris; de Wit, Cor; Kaiser, Frank J; Braunholz, Diana; Medack, Anja; Fischer, Marcus; Zimmermann, Martina E; Tennstedt, Stephanie; Graf, Elisabeth; Eck, Sebastian; Aherrahrou, Zouhair; Nahrstaedt, Janja; Willenborg, Christina; Bruse, Petra; Brænne, Ingrid; Nöthen, Markus M; Hofmann, Per; Braund, Peter S; Mergia, Evanthia; Reinhard, Wibke; Burgdorf, Christof; Schreiber, Stefan; Balmforth, Anthony J; Hall, Alistair S; Bertram, Lars; Steinhagen-Thiessen, Elisabeth; Li, Shu-Chen; März, Winfried; Reilly, Muredach; Kathiresan, Sekar; McPherson, Ruth; Walter, Ulrich; Ott, Jurg; Samani, Nilesh J; Strom, Tim M; Meitinger, Thomas; Hengstenberg, Christian; Schunkert, Heribert

2013-12-19

Myocardial infarction, a leading cause of death in the Western world, usually occurs when the fibrous cap overlying an atherosclerotic plaque in a coronary artery ruptures. The resulting exposure of blood to the atherosclerotic material then triggers thrombus formation, which occludes the artery. The importance of genetic predisposition to coronary artery disease and myocardial infarction is best documented by the predictive value of a positive family history. Next-generation sequencing in families with several affected individuals has revolutionized mutation identification. Here we report the segregation of two private, heterozygous mutations in two functionally related genes, GUCY1A3 (p.Leu163Phefs*24) and CCT7 (p.Ser525Leu), in an extended myocardial infarction family. GUCY1A3 encodes the α1 subunit of soluble guanylyl cyclase (α1-sGC), and CCT7 encodes CCTη, a member of the tailless complex polypeptide 1 ring complex, which, among other functions, stabilizes soluble guanylyl cyclase. After stimulation with nitric oxide, soluble guanylyl cyclase generates cGMP, which induces vasodilation and inhibits platelet activation. We demonstrate in vitro that mutations in both GUCY1A3 and CCT7 severely reduce α1-sGC as well as β1-sGC protein content, and impair soluble guanylyl cyclase activity. Moreover, platelets from digenic mutation carriers contained less soluble guanylyl cyclase protein and consequently displayed reduced nitric-oxide-induced cGMP formation. Mice deficient in α1-sGC protein displayed accelerated thrombus formation in the microcirculation after local trauma. Starting with a severely affected family, we have identified a link between impaired soluble-guanylyl-cyclase-dependent nitric oxide signalling and myocardial infarction risk, possibly through accelerated thrombus formation. Reversing this defect may provide a new therapeutic target for reducing the risk of myocardial infarction.

The influence of neck thrombus on clinical outcome and aneurysm morphology after endovascular aneurysm repair

NARCIS (Netherlands)

F.M.V. Bastos Gonçalves (Frederico); H.J.M. Verhagen (Hence); K. Chinsakchai (Khamin); J.W. van Keulen (Jasper); M.T. Voûte (Michiel); H.J.A. Zandvoort (Herman); F.L. Moll (Frans); J.A. van Herwaarden (Joost)

2012-01-01

textabstractObjective: This study investigated the influence of significant aneurysm neck thrombus in clinical and morphologic outcomes after endovascular aneurysm repair (EVAR). Methods: The patient population was derived from a prospective EVAR database from two university institutions in The

[Ultrasound dynamics lysis apex thrombus as an objective criterion of effectiveness of anticoagulation therapy in venous thrombosis].

Science.gov (United States)

Kalinin, R E; Suchkov, I A; Pshennikov, A S; Agapov, A B

2016-01-01

To assess the effectiveness of anticoagulant therapy (ACT) for the treatment of patients with deep venous thrombosis (DVT) of the lower extremities. The study considered ultrasonic characteristics of lysis of the proximal part of thrombus: localization and nature of venous thrombosis, the length and diameter of the proximal floating part of the thrombus, and duration of the venous thrombosis. Depending on the ACT options patients were divided into 3 groups: Group 1 (18 patients) received rivaroxaban, group 2 (19 patients) received enoxaparin sodium with subsequent transition to warfarin, and 3 group (19 patietns) received enoxaparin sodium, followed by administration of rivaroxaban. Treatment with rivaroxaban was preferable over standard ACT with enoxaparin/warfarin with regards to the lysis of thrombus when duration of thrombosis did not exceed 10 days. In 10.5% of patients who received warfarin flotation of thrombi remained for 14 days; the length of the floating part of the thrombi did not exceed 3 cm. Such circumstances and inability to reach a therapeutic INR value required cava filter placement. Treatment with enoxaparin sodium followed by the administration of rivaroxaban was found to be the most efficient ACT regimen as there was no negative dynamics of ultrasound characteristics of lysis of thrombi at any duration of the disease.

Echocardiographic assessment with right ventricular function improvement following ultrasound-accelerated catheter-directed thrombolytic therapy in submassive pulmonary embolism.

Science.gov (United States)

Doheny, Charles; Gonzalez, Lorena; Duchman, Stanley M; Varon, Joseph; Bechara, Carlos F; Cheung, Mathew; Lin, Peter H

2018-06-01

Introduction The objective of this study was to evaluate the efficacy of ultrasound-accelerated catheter-directed thrombolytic therapy in patients with submassive pulmonary embolism. Methods Clinical records of 46 patients with submassive pulmonary embolism who underwent ultrasound-accelerated catheter-directed pulmonary thrombolysis using tissue plasminogen activator, from 2007 to 2017, were analyzed. All patients experienced clinical symptoms with computed tomography evidence of pulmonary thrombus burden. Right ventricular dysfunction was present in all patients by echocardiographic finding of right ventricle-to-left ventricle ratio > 0.9. Treatment outcome, procedural complications, right ventricular pressures, and thrombus clearance were evaluated. Follow-up evaluation included echocardiographic assessment of right ventricle-to-left ventricle ratio at one month, six months, and one year. Results Technical success was achieved in all patients ( n = 46, 100%). Our patients received an average of 18.4 ± 4.7 mg of tissue plasminogen activator using ultrasound-accelerated thrombolytic catheter with an average infusion time of 16.5± 5.4 h. Clinical success was achieved in all patients (100%). Significant reduction of mean pulmonary artery pressure occurred following the treatment, which decreased from 36 ± 8 to 21 ± 5 mmHg ( p right ventricular dysfunction based on echocardiographic assessment. The right ventricle-to-left ventricle ratio decreased from 1.32 ± 0.18 to 0.91 ± 0.13 at the time of hospital discharge ( p right ventricular function remained improved at 6 months and 12 months of follow-up, as right ventricle-to-left ventricle ratio were 0.92 ± 0.14 ( p right ventricular function in patients with submassive pulmonary embolism.

Interobserver Variability in Target Definition for Hepatocellular Carcinoma With and Without Portal Vein Thrombus: Radiation Therapy Oncology Group Consensus Guidelines

Energy Technology Data Exchange (ETDEWEB)

Hong, Theodore S., E-mail: tshong1@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Bosch, Walter R. [Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, Missouri (United States); Krishnan, Sunil [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kim, Tae K. [Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women' s College Hospital, University of Toronto, Toronto, Ontario (Canada); Mamon, Harvey J. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Shyn, Paul [Department of Radiology, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Ben-Josef, Edgar [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania (United States); Seong, Jinsil [Department of Radiation Oncology, Yonsei University Medical College, Seoul (Korea, Republic of); Haddock, Michael G. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Cheng, Jason C. [Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Feng, Mary U. [Department of Radiation Oncology, University of Michigan Health System, Ann Arbor, Michigan (United States); Stephans, Kevin L. [Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Roberge, David [Department of Radiation Oncology, Montreal General Hospital/McGill University Health Centre, Montreal, Quebec (Canada); Crane, Christopher [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); and others

2014-07-15

Purpose: Defining hepatocellular carcinoma (HCC) gross tumor volume (GTV) requires multimodal imaging, acquired in different perfusion phases. The purposes of this study were to evaluate the variability in contouring and to establish guidelines and educational recommendations for reproducible HCC contouring for treatment planning. Methods and Materials: Anonymous, multiphasic planning computed tomography scans obtained from 3 patients with HCC were identified and distributed to a panel of 11 gastrointestinal radiation oncologists. Panelists were asked the number of HCC cases they treated in the past year. Case 1 had no vascular involvement, case 2 had extensive portal vein involvement, and case 3 had minor branched portal vein involvement. The agreement between the contoured total GTVs (primary + vascular GTV) was assessed using the generalized kappa statistic. Agreement interpretation was evaluated using Landis and Koch's interpretation of strength of agreement. The S95 contour, defined using the simultaneous truth and performance level estimation (STAPLE) algorithm consensus at the 95% confidence level, was created for each case. Results: Of the 11 panelists, 3 had treated >25 cases in the past year, 2 had treated 10 to 25 cases, 2 had treated 5 to 10 cases, 2 had treated 1 to 5 cases, 1 had treated 0 cases, and 1 did not respond. Near perfect agreement was seen for case 1, and substantial agreement was seen for cases 2 and 3. For case 2, there was significant heterogeneity in the volume identified as tumor thrombus (range 0.58-40.45 cc). For case 3, 2 panelists did not include the branched portal vein thrombus, and 7 panelists contoured thrombus separately from the primary tumor, also showing significant heterogeneity in volume of tumor thrombus (range 4.52-34.27 cc). Conclusions: In a group of experts, excellent agreement was seen in contouring total GTV. Heterogeneity exists in the definition of portal vein thrombus that may impact treatment

Computed tomographic diagnosis of calcified inferior vena cava thrombus in a child with Wilm's tumor

Energy Technology Data Exchange (ETDEWEB)

Kirks, D R; Ponzi, J W; Korobkin, M

1980-01-01

A calcified thrombus in the inferior vena cava of infants and children may be imaged by computed tomography. The precise location of the calcification within the inferior vena cava may be confirmed by computed tomographic scanning during injection of intravenous contrast material.

A Tenured Faith and an Adjunct Faculty: Successes and Challenges in Instructor Formation at Catholic Colleges that Offer Business Programs in an Accelerated Format

Science.gov (United States)

Gambrall, Doug; Newcomb, Mark A.

2009-01-01

Many Catholic colleges in the United States offer Business programs in an accelerated format, featuring evening courses for adult learners, with few faculty contact hours than traditional classes. Most of these institutions believe in the ideals of Catholic Social Teaching and wish to integrate those principles into their curricula for the sake of…

The model of pulmonary embolism caused by autologous thrombus in rabbits

OpenAIRE

Yu-Jiao Ding; Yang Chen

2017-01-01

Objective: To establish a model of pulmonary embolism in rabbits by using autologous thrombosis of rabbit ear vein, to study the method of establishing acute pulmonary embolism by using autologous thrombus and to explore the diagnostic value of oxygen partial pressure in acute pulmonary embolism. Methods: Twenty rabbits were randomly divided into normal group (n=5), 7 h group, 24h group, 1 week after model establishment Group. The arterial blood gas analysis was performed on th...

Numerical simulation of particle jet formation induced by shock wave acceleration in a Hele-Shaw cell

Science.gov (United States)

Osnes, A. N.; Vartdal, M.; Pettersson Reif, B. A.

2018-05-01

The formation of jets from a shock-accelerated cylindrical shell of particles, confined in a Hele-Shaw cell, is studied by means of numerical simulation. A number of simulations have been performed, systematically varying the coupling between the gas and solid phases in an effort to identify the primary mechanism(s) responsible for jet formation. We find that coupling through drag is sufficient for the formation of jets. Including the effect of particle volume fraction and particle collisions did not alter the general behaviour, but had some influence on the length, spacing and number of jets. Furthermore, we find that the jet selection process starts early in the dispersal process, during the initial expansion of the particle layer.

An integrated fluid-chemical model towards modeling the formation of intra-luminal thrombus in abdominal aortic aneurysms

Directory of Open Access Journals (Sweden)

Jacopo eBiasetti

2012-07-01

Full Text Available Abdominal Aortic Aneurysms (AAAs are frequently characterized by the presenceof an Intra-Luminal Thrombus (ILT known to influence biochemically and biomechanicallytheir evolution. ILT progression mechanism is still unclear and little is known regardingthe impact on this mechanism of the chemical species transported by blood flow.Chemical agonists and antagonists of platelets activation, aggregation, and adhesion andthe proteins involved in the coagulation cascade (CC may play an important role in ILTdevelopment. Starting from this assumption, the evolution of chemical species involvedin the CC, their relation to coherent vortical structures (VSs and their possible effect onILT evolution have been studied. To this end a fluido-chemical model that simulates theCC through a series of convection-diffusion-reaction (CDR equations has been developed.The model involves plasma-phase and surface bound enzymes and zymogens, and includesboth plasma-phase and membrane-phase reactions. Blood is modeled as a non-Newtonianincompressible fluid. VSs convect thrombin in the domain and lead to the high concentration observed in the distal portion of the AAA. This finding is in line with the clinicalobservations showing that the thickest ILT is usually seen in the distal AAA region. Theproposed model, due to its ability to couple the fluid and chemical domains, provides anintegrated mechanochemical picture that potentially could help unveil mechanisms of ILTformation and development.

Is Thrombus With Subcutaneous Edema Detected by Ultrasonography Related to Short Peripheral Catheter Failure? A Prospective Observational Study.

Science.gov (United States)

Takahashi, Toshiaki; Murayama, Ryoko; Oe, Makoto; Nakagami, Gojiro; Tanabe, Hidenori; Yabunaka, Koichi; Arai, Rika; Komiyama, Chieko; Uchida, Miho; Sanada, Hiromi

Short peripheral catheter (SPC) failure is an important clinical problem. The purpose of this study was to clarify the relationship between SPC failure and etiologies such as thrombus, subcutaneous edema, and catheter dislodgment using ultrasonography and to explore the risk factors associated with the etiologies. Two hundred catheters that were in use for infusion, excluding chemotherapy, were observed. Risk factors were examined by logistic regression analysis. Sixty catheters were removed as the result of SPC failure. Frequency of thrombus with subcutaneous edema in SPC failure cases was significantly greater than in those cases where therapy was completed without complications (P edema. Results suggest that subsurface skin assessment for catheterization could prevent SPC failure.

In vivo distribution of Tc-99m labeled recombinant tissue-type plasminogen activator in control and thrombus-bearing rats

International Nuclear Information System (INIS)

Tsukamoto, Eriko

1992-01-01

In vivo distribution of Tc-99m labeled recombinant tissue-type plasminogen activator (Tc-99m-rt-PA) was studied in control rats and thrombus-bearing rats. To compare fibrin binding in vivo with that in vitro, Tc-99m-rt-PA binding to fibrin gel in vitro was also imaged. Rapid blood clearance and accumulation into the liver and kidneys were observed in both control and thrombus-bearing rats. Accumulation in the stomach, which indicates instability of labeled rt-PA in vivo, was very low until two hours after injection. Tc-99m-rt-PA accumulation in the clots was higher than that in skeletal and heart muscles, although it was lower than in blood, liver, and kidneys. Administration of aprotinin, an antifibrinolytic agent, significantly prolonged clot accumulation of Tc-99m-rt-PA at 30 minutes after injection. These results suggest that fibrinolysis is responsible for the low rt-PA concentration in the clots. A scintigram of a thrombus-bearing rat demonstrated increased radioactivity at the clot forming site. On the other hand, Tc-99m-labeled human albumin, which was used as a control, was not accumulated in the clot. Tc-99m-rt-PA binding to fibrin gel in vitro was clearly imaged. By comparison, in vivo fibrin binding of Tc-99m-rt-PA was much lower than in vitro. The reasons for low thrombus uptake in vivo may be: (1) biochemical inactivation of extrinsically administered rt-PA by t-PA inhibitor; (2) fibrinolysis by rt-PA activated plasminogen. Overcoming these limitations will enable Tc-99m-rt-PA to reach the stage of clinical trials. (author)

Portal Vein Tumor Thrombus of Liver Metastasis from Lung Cancer

Directory of Open Access Journals (Sweden)

Ryoko Ogawa

2009-01-01

Full Text Available We report a case of liver metastasis of lung carcinoma with portal vein tumor thrombus (PVTT. Although the primary lesion of lung tumor remained unchanged, the patient rapidly developed wide-spread metastases and formed PVTT of liver metastasis. The primary lesion showed features of mixed Clara and bronchial surface epithelial cell component type adenocarcinoma with small foci of micropapillary pattern. Micropapillary pattern was observed in the metastatic lesions in the liver and PVTT. Micropapillary pattern lung adenocarcinoma may develop rapid metastases and cause PVTT associated with liver metastasis. We should perform a detailed examination to establish correct diagnosis.

Particle radiotherapy, a novel external radiation therapy, versus liver resection for hepatocellular carcinoma accompanied with inferior vena cava tumor thrombus: A matched-pair analysis.

Science.gov (United States)

Komatsu, Shohei; Kido, Masahiro; Asari, Sadaki; Toyama, Hirochika; Ajiki, Tetsuo; Demizu, Yusuke; Terashima, Kazuki; Okimoto, Tomoaki; Sasaki, Ryohei; Fukumoto, Takumi

2017-12-01

Hepatocellular carcinoma accompanied with inferior vena cava tumor thrombus carries a dismal prognosis, and the feasibility of local treatment has remained controversial. The present study aimed to compare the outcomes of particle radiotherapy and liver resection in patients with hepatocellular carcinoma with inferior vena cava tumor thrombus. Thirty-one and 19 patients, respectively, underwent particle radiotherapy and liver resection for hepatocellular carcinoma with inferior vena cava tumor thrombus. A matched-pair analysis was undertaken to compare the short- and long-term outcomes according to tumor stage determined using the tumor-node-metastasis classification. Both stages IIIB and IV (IVA and IVB) patients were well-matched for 12 factors, including treatment policy and patient and tumor characteristics. The median survival time of matched patients with stage IIIB tumors in the particle radiotherapy group was greater than that in the liver resection group (748 vs 272 days, P = .029), whereas no significant difference was observed in the median survival times of patients with stage IV tumors (239 vs 311 days, respectively). There were significantly fewer treatment-related complications of grade 3 or greater in the particle radiotherapy group (0%) than in the liver resection group (26%). Particle radiotherapy is potentially preferable in hepatocellular carcinoma patients with stage IIIB inferior vena cava tumor thrombus and at least equal in efficiency to liver resection in those with stage IV disease, while causing significantly fewer complications. Considering the relatively high survival and low invasiveness of particle radiotherapy when compared to liver resection, this approach may represent a novel treatment modality for hepatocellular carcinoma with inferior vena cava tumor thrombus. Copyright © 2017 Elsevier Inc. All rights reserved.

On the formation of auroral arcs and acceleration of auroral electrons

International Nuclear Information System (INIS)

Swift, D.W.

1975-01-01

It is suggested that the highly structured auroral arc is caused by a current-driven laminar electrostatic shock oblique to the geomagnetic field. Electrons are accelerated by the potential jump associated with the shock. The shock is assumed to be confined to a plane. Self-consistent solutions to the Poisson-Vlasov systems are calculated for the electrostatic potential. A diabatic theory is used to calculate the ion number density in terms of the electrostatic potential and its derivatives. The electrons are assumed to be highly magnetized so they can only move parallel to the magnetic field. Solutions are exhibited for two plasma models: (1) streaming electrons and a two-temperature distribution of ions and (2) streaming electrons and ions and thermal electrons and ions. In the latter model, solutions can be obtained for an arbitrary potential jump across the shock. The shock is identified with the linear electrostatic ion cyclotron wave, and stability of these waves is examined to determine conditions for the formation of oblique shocks. Finally, the theory is discussed in the context of the magnetosphere, and possible model shocks are exhibited and discussed in terms of auroral arc formation

Magnetic resonance direct thrombus imaging of the evolution of acute deep vein thrombosis of the leg.

Science.gov (United States)

Westerbeek, R E; Van Rooden, C J; Tan, M; Van Gils, A P G; Kok, S; De Bats, M J; De Roos, A; Huisman, M V

2008-07-01

Accurate diagnosis of acute recurrent deep vein thrombosis (DVT) is relevant to avoid improper diagnosis and unnecessary life-long anticoagulant treatment. Compression ultrasound has high accuracy for a first episode of DVT, but is often unreliable in suspected recurrent disease. Magnetic resonance direct thrombus imaging (MR DTI) has been shown to accurately detect acute DVT. The purpose of this prospective study was to determine the MR signal change during 6 months follow-up in patients with acute DVT. This study was a prospective study of 43 consecutive patients with a first episode of acute DVT demonstrated by compression ultrasound. All patients underwent MR DTI. Follow-up was performed with MR-DTI and compression ultrasound at 3 and 6 months respectively. All data were coded, stored and assessed by two blinded observers. MR direct thrombus imaging identified acute DVT in 41 of 43 patients (sensitivity 95%). There was no abnormal MR-signal in controls, or in the contralateral extremity of patients with DVT (specificity 100%). In none of the 39 patients available at 6 months follow-up was the abnormal MR-signal at the initial acute DVT observed, whereas in 12 of these patients (30.8%) compression ultrasound was still abnormal. Magnetic resonance direct thrombus imaging normalizes over a period of 6 months in all patients with diagnosed DVT, while compression ultrasound remains abnormal in a third of these patients. MR-DTI may potentially allow for accurate detection in patients with acute suspected recurrent DVT, and this should be studied prospectively.

Ischemic Left Ventricular Perforation Covered by a Thrombus in a Patient Presenting with Cerebral Ischemia: Importance of Time-Sensitive Performance and Adequate Interpretation of Bedside Transthoracic Echography

Directory of Open Access Journals (Sweden)

A. J. Fischer

2016-01-01

Full Text Available If myocardial infarction remains silent, only clinical signs of complications may unveil its presence. Life-threatening complications include myocardial rupture, thrombus formation, or arterial embolization. In the presented case, a 76-year-old patient was admitted with left-sided hemiparesis. In duplex sonography, a critical stenosis of the right internal carotid artery was identified and initially but retrospectively incorrectly judged as the potential cause for ischemia. During operative thromboendarterectomy, arterial embolism of the right leg occurred coincidentally, more likely pointing towards a cardioembolic origin. Percutaneous interventions remained unsuccessful and local fibrinolysis was applied. Delayed bedside echocardiography by an experienced cardiologist demonstrated a discontinuity of the normal myocardial texture of the left ventricular apex together with an echodense, partly floating structure merely attached by a thin bridge not completely sealing the myocardial defect, accompanied by pericardial effusion. The patient was immediately transferred to emergency cardiac surgery with extirpation of the thrombus, aortocoronary bypass graft placement, and aneurysmectomy. This didactic case reveals decisive structural shortcomings in patient’s admission and triage processes and underlines, if performed timely and correctly, the value of transthoracic echocardiography as a noninvasive and cost-effective tool allowing immediate decision-making, which, in this case, led to the correct but almost fatally delayed diagnosis.

Ischemic Left Ventricular Perforation Covered by a Thrombus in a Patient Presenting with Cerebral Ischemia: Importance of Time-Sensitive Performance and Adequate Interpretation of Bedside Transthoracic Echography.

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Fischer, A J; Lebiedz, P; Wiaderek, M; Lichtenberg, M; Böse, D; Martens, S; Breuckmann, F

2016-01-01

If myocardial infarction remains silent, only clinical signs of complications may unveil its presence. Life-threatening complications include myocardial rupture, thrombus formation, or arterial embolization. In the presented case, a 76-year-old patient was admitted with left-sided hemiparesis. In duplex sonography, a critical stenosis of the right internal carotid artery was identified and initially but retrospectively incorrectly judged as the potential cause for ischemia. During operative thromboendarterectomy, arterial embolism of the right leg occurred coincidentally, more likely pointing towards a cardioembolic origin. Percutaneous interventions remained unsuccessful and local fibrinolysis was applied. Delayed bedside echocardiography by an experienced cardiologist demonstrated a discontinuity of the normal myocardial texture of the left ventricular apex together with an echodense, partly floating structure merely attached by a thin bridge not completely sealing the myocardial defect, accompanied by pericardial effusion. The patient was immediately transferred to emergency cardiac surgery with extirpation of the thrombus, aortocoronary bypass graft placement, and aneurysmectomy. This didactic case reveals decisive structural shortcomings in patient's admission and triage processes and underlines, if performed timely and correctly, the value of transthoracic echocardiography as a noninvasive and cost-effective tool allowing immediate decision-making, which, in this case, led to the correct but almost fatally delayed diagnosis.

Long-term survival after liver transplant for recurrent hepatocellular carcinoma with bile duct tumor thrombus: case report.

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Liu, Chao; Wang, Jie

2012-12-01

Hepatocellular carcinoma with bile duct tumor thrombus is considered an aggressive malignancy, and the prognosis of liver transplant for it remains obscure. A 42-year-old man with recurrent hepatocellular carcinoma and a history of surgical resection was admitted to our hospital with a 10-day history of yellowish urine and itchy skin. There were 3 lesions in the right lobe with the diameter of 2 cm each. A mass was found in the upper part of common bile duct, and the intrahepatic bile duct was dilated. His serum alpha-fetoprotein level was 2476 μg/L, total bilirubin level was 327 μmol/L, direct bilirubin level was 261 μmol/L, and alanine aminotransferase was 714 U/L. There was no main portal vein thrombus or extrahepatic metastases. Because of his poor liver function, he was listed for a liver transplant. During the wait (30 d), he underwent 9 episodes of plasmapheresis to decrease the serum level of bilirubin. He had an orthotopic liver transplant with the graft from a deceased donor. After the liver transplant, he received 5 cycles of chemotherapy with the regimen of oxaliplatin and 5-fluorouracil. This patient has survived without recurrence of hepatocellular carcinoma for more than 82 months and remains in good condition. Liver transplant may have a favorable result for hepatocellular carcinoma patient with a bile duct tumor thrombus, within the Milan criteria.

Overwork accelerates thrombotic reaction: implications for the pathogenesis of Karoshi.

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Otsui, Kazunori; Yamamoto, Junichiro; Inoue, Nobutaka

2018-02-01

Work-related stressors are potential causes of cardiovascular diseases (CVDs) and stroke; however, the pathophysiological mechanisms by which occupational stress induces and exacerbates CVDs remain unclear. The global thrombosis test (GTT) is a novel in vitro assay for evaluating both thrombotic reactions and subsequent thrombolysis. The time required to form an occlusive thrombus with the GTT, called as the occlusion time (OT), and the time to lyse the thrombus, the lysis time (LT), are markers of thrombotic and thrombolytic reactions, respectively. We investigated the impact of work-related stress on the thrombotic and thrombolytic reactions in 46 healthy medical residents. Off-duty or on-duty blood samples were collected on the mornings of non-work days or after the night duty on the emergent room respectively. The duration of sleep was significantly shorter during night duty than during off-duty nights [2.25 (1.0, 3.0) h vs. 6.0 (5.0, 7.0) h; p < 0.001]. Baseline OT was 310.3 (260.9, 437.7) s. whereas the on-duty OT was significantly shortened [284.2 (230.5, 355.8) s; p < 0.01]. LT was significantly prolonged during overwork conditions compared with off-duty conditions [1547 (1346, 1908) s vs. 1470 (1219, 1692) s; p < 0.05]. Overwork accelerates the thrombotic reactions. These reactions might explain the pathogenesis of overwork-related CVDs. The GTT is a good tool for evaluating of the level of fatigue.

Accelerated Electron-Beam Formation with a High Capture Coefficient in a Parallel Coupled Accelerating Structure

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Chernousov, Yu. D.; Shebolaev, I. V.; Ikryanov, I. M.

2018-01-01

An electron beam with a high (close to 100%) coefficient of electron capture into the regime of acceleration has been obtained in a linear electron accelerator based on a parallel coupled slow-wave structure, electron gun with microwave-controlled injection current, and permanent-magnet beam-focusing system. The high capture coefficient was due to the properties of the accelerating structure, beam-focusing system, and electron-injection system. Main characteristics of the proposed systems are presented.

Temporary dietary iron restriction affects the process of thrombus resolution in a rat model of deep vein thrombosis.

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Makiko Oboshi

Full Text Available Deep vein thrombosis (DVT is a major cause of pulmonary thromboembolism and sudden death. Thus, it is important to consider the pathophysiology of DVT. Recently, iron has been reported to be associated with thrombotic diseases. Hence, in this study, we investigate the effects of dietary iron restriction on the process of thrombus resolution in a rat model of DVT.We induced DVT in 8-week-old male Sprague-Dawley rats by performing ligations of their inferior venae cavae. The rats were then given either a normal diet (DVT group or an iron-restricted diet (DVT+IR group. Thrombosed inferior venae cavae were harvested at 5 days after ligation.The iron-restricted diet reduced venous thrombus size compared to the normal diet. Intrathrombotic collagen content was diminished in the DVT+IR group compared to the DVT group. In addition, intrathrombotic gene expression and the activity of matrix metalloproteinase-9 were increased in the DVT+IR group compared to the DVT group. Furthermore, the DVT+IR group had greater intrathrombotic neovascularization as well as higher gene expression levels of urokinase-type plasminogen activator and tissue-type plasminogen activator than the DVT group. The iron-restricted diet decreased intrathrombotic superoxide production compared to the normal diet.These results suggest that dietary iron restriction affects the process of thrombus resolution in DVT.

Temporary dietary iron restriction affects the process of thrombus resolution in a rat model of deep vein thrombosis.

Science.gov (United States)

Oboshi, Makiko; Naito, Yoshiro; Sawada, Hisashi; Hirotani, Shinichi; Iwasaku, Toshihiro; Okuhara, Yoshitaka; Morisawa, Daisuke; Eguchi, Akiyo; Nishimura, Koichi; Fujii, Kenichi; Mano, Toshiaki; Ishihara, Masaharu; Masuyama, Tohru

2015-01-01

Deep vein thrombosis (DVT) is a major cause of pulmonary thromboembolism and sudden death. Thus, it is important to consider the pathophysiology of DVT. Recently, iron has been reported to be associated with thrombotic diseases. Hence, in this study, we investigate the effects of dietary iron restriction on the process of thrombus resolution in a rat model of DVT. We induced DVT in 8-week-old male Sprague-Dawley rats by performing ligations of their inferior venae cavae. The rats were then given either a normal diet (DVT group) or an iron-restricted diet (DVT+IR group). Thrombosed inferior venae cavae were harvested at 5 days after ligation. The iron-restricted diet reduced venous thrombus size compared to the normal diet. Intrathrombotic collagen content was diminished in the DVT+IR group compared to the DVT group. In addition, intrathrombotic gene expression and the activity of matrix metalloproteinase-9 were increased in the DVT+IR group compared to the DVT group. Furthermore, the DVT+IR group had greater intrathrombotic neovascularization as well as higher gene expression levels of urokinase-type plasminogen activator and tissue-type plasminogen activator than the DVT group. The iron-restricted diet decreased intrathrombotic superoxide production compared to the normal diet. These results suggest that dietary iron restriction affects the process of thrombus resolution in DVT.

Infection of a ventricular aneurysm and cardiac mural thrombus. Survival after surgical resection

International Nuclear Information System (INIS)

Venezio, F.R.; Thompson, J.E.; Sullivan, H.; Subramanian, R.; Ritzman, P.; Gunnar, R.M.

1984-01-01

Infections of cardiac mural thrombi are rare, and because antemortem diagnosis is difficult and antibiotic therapy alone ineffective, the associated mortality has been significant. A patient with gram-negative bacillary infection of a mural thrombus is described. Gallium 67 citrate isotope scanning and two-dimensional echocardiography were helpful adjuncts in establishing the diagnosis. Surgical resection of the infected myocardial tissue and prolonged antimicrobial therapy were necessary for cure

Renal Angiomyolipoma with Fatty Thrombus Extending to the Right Atrium: An Exceptional Presentation

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Yassine Nouira

2013-01-01

Full Text Available This paper reports the case of 34-year-old woman who presented with bilateral renal angiomyolipomas (AMLs. On the right side, there was a large AML with a fatty thrombus extending to the right atrium. The treatment consisted of right nephrectomy and complete thrombectomy with extracorporeal circulation and right atriotomy. Postoperatively, the patient was septic and died on postoperative day 7 because of septic shock.

Non-vitamin K antagonist oral anticoagulants versus warfarin for the prevention of spontaneous echo-contrast and thrombus in patients with atrial fibrillation or flutter undergoing cardioversion: A trans-esophageal echocardiography study.

Science.gov (United States)

Kim, Yun Gi; Choi, Jong-Il; Kim, Mi-Na; Cho, Dong-Hyuk; Oh, Suk-Kyu; Kook, Hyungdon; Park, Hee-Soon; Lee, Kwang No; Baek, Yong-Soo; Roh, Seung-Young; Shim, Jaemin; Park, Seong-Mi; Shim, Wan Joo; Kim, Young-Hoon

2018-01-01

Spontaneous echo-contrast (SEC) and thrombus observed in trans-esophageal echocardiography (TEE) is known as a strong surrogate marker for future risk of ischemic stroke in patients with atrial fibrillation (AF) or atrial flutter (AFL). The efficacy of non-vitamin K antagonist oral anticoagulants (NOAC) compared to warfarin to prevent SEC or thrombus in patients with AF or AFL is currently unknown. AF or AFL patients who underwent direct current cardioversion (DCCV) and pre-DCCV TEE evaluation from January 2014 to October 2016 in a single center were analyzed. The prevalence of SEC and thrombus were compared between patients who received NOAC and those who took warfarin. NOAC included direct thrombin inhibitor and factor Xa inhibitors. Among 1,050 patients who were considered for DCCV, 424 patients anticoagulated with warfarin or NOAC underwent TEE prior to DCCV. Eighty patients who were anticoagulated for less than 21 days were excluded. Finally, 344 patients were included for the analysis (180 warfarin users vs. 164 NOAC users). No significant difference in the prevalence of SEC (44.4% vs. 43.9%; p = 0.919), dense SEC (13.9% vs. 15.2%; p = 0.722), or thrombus (2.2% vs. 4.3%; p = 0.281) was observed between the warfarin group and the NOAC group. In multivariate analysis, there was no association between NOAC and risk of SEC (odds ratio [OR]: 1.4, 95% CI: 0.796-2.297, p = 0.265) or thrombus (OR: 3.4, 95% CI: 0.726-16.039, p = 0.120). In conclusion, effectiveness of NOAC is comparable to warfarin in preventing SEC and thrombus in patients with AF or AFL undergoing DCCV. However, numerical increase in the prevalence of thrombus in NOAC group warrants further evaluation.

Apospory appears to accelerate onset of meiosis and sexual embryo sac formation in sorghum ovules

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Elliott Estella

2011-01-01

Full Text Available Abstract Background Genetically unreduced (2n embryo sacs (ES form in ovules of gametophytic apomicts, the 2n eggs of which develop into embryos parthenogenetically. In many apomicts, 2n ES form precociously during ovule development. Whether meiosis and sexual ES formation also occur precociously in facultative apomicts (capable of apomictic and sexual reproduction has not been studied. We determined onset timing of meiosis and sexual ES formation for 569 Sorghum bicolor genotypes, many of which produced 2n ES facultatively. Results Genotype differences for onset timing of meiosis and sexual ES formation, relative to ovule development, were highly significant. A major source of variation in timing of sexual germline development was presence or absence of apomictic ES, which formed from nucellar cells (apospory in some genotypes. Genotypes that produced these aposporous ES underwent meiosis and sexual ES formation precociously. Aposporous ES formation was most prevalent in subsp. verticilliflorum and in breeding lines of subsp. bicolor. It was uncommon in land races. Conclusions The present study adds meiosis and sexual ES formation to floral induction, apomictic ES formation, and parthenogenesis as processes observed to occur precociously in apomictic plants. The temporally diverse nature of these events suggests that an epigenetic memory of the plants' apomixis status exists throughout its life cycle, which triggers, during multiple life cycle phases, temporally distinct processes that accelerate reproduction.

The Formation of Plasma by Injection and Dissociation of Accelerated Hydrogen ''Granions''

International Nuclear Information System (INIS)

Bottiglioni, F.; Coutant, J.; Fois, M.; Prevot, F.

1971-01-01

The INGRA experiment is an experimental study of the formation of a hot-ion plasma (T i ≃ 1.5 keV) by the injection, dissociation and capture of a beam of accelerated hydrogen ''granions'' in a magnetic configuration. The granions are agglomerates of hydrogen atoms with one or more positive electric charges. The accelerator is described in the paper. The neutral agglomerates (granules) produced in a supersonic jet of hydrogen, previously cooled to the region of the liquefying temperature, are charged by electron bombardment and accelerated to 600 kV by an electrostatic potential difference. Mass analysis of the accelerated beam is carried out by means of a magnetic separator, which can be used for analysing mass/charge numbers N/Z up to 10 000 at 600 keV. Using an 0.3 x 4 mm capillary nozzle, one can obtain in the continuous régime a beam of the order of 70 mA equivalent (4 x 10 17 atoms/s), whose mass spectrum is very broad and hasa maximum N/Z close to 100, corresponding at 600 keV to an energy of 6 keV/atom. A definite increase in the beam intensity can be obtained by increasing the pressure upstream of the expansion at the same time as the capillary temperature. There is also an increase in the granule size; the electron density in the ionizer must then be increased to bring the mean mass of the granions to the values of interest (N/2 ≃ 100 to 500). To take into account the reduced mean mass in the ionizer, the authors propose a model which assumes that when an electron ionizes a granion that has already been singly charged, the granion dissociates spontaneously by electrostatic repulsion into two granions of complementary mass, each with a charge, in a process of the following type: H + N + e -> H N ++ + H + (1-f)N + 2e with 0 2/3 are in good agreement with experimental results. (author). (author) [fr

Occlusive Hepatic Artery Thrombus in a Deceased-Donor Liver Procured From a Donor With Blunt Abdominal Trauma Following a Road Traffic Collision Accident.

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Ahmad, Niaz; Tahir, Wasif; Haque, Ali; Dar, Faisal; Vilca-Melendez, Hector; Srinavasan, Parthi; Heaton, Nigel

2018-04-09

Here, we describe a case of occlusive hepatic artery thrombus in a liver procured from an 18-year-old deceased donor after circulatory death. The donor had died of multiple trauma following a road traffic collision. Occlusive thrombus was found at the hepatic artery bifurcation during back-table preparation. Consequently, the liver transplant did not proceed. We suggest careful assessment of hepatic arteries of all donor livers before transplant, particularly those from donors who are involved in deceleration injuries. Transplanting such livers may lead to primary nonfunction.

Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation.

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Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang Sei; Park, Sung Kyeong; Lee, Sung-Pyo; Choi, Ehn-Kyoung; Rhee, Man Hee; Kim, Yun-Bae

2013-12-01

The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-dependent manner. Rats were orally administered with nattokinase for 1 week, and their carotid arteries were exposed. Arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Nattokinase delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 160 mg/kg. In addition, a high dose (500 mg/kg) of nattokinase fully prevented the occlusion, as achieved with aspirin (30 mg/kg). The results indicate that nattokinase extracted from fermented soybean inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is suggested that nattokinase could be a good candidate without adverse effects for the improvement of blood flow.

Thrombus Development on a Transseptal Sheath in the Right Atrium Before Electrical Pulmonary Vein Isolation

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Nieves Romero-Rodriguez

2008-02-01

Full Text Available We describe the case of a patient who developed a thrombus on the transseptal sheath in the right atrium before transseptal puncture for circumferential pulmonary vein isolation for paroxysmal atrial fibrillation treatment. The use of intracardiac echocardiography allowed to its identification and probably prevented the patient from suffering a serious thromboembolic complication.

Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation

OpenAIRE

Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang Sei; Park, Sung Kyeong; Lee, Sung-Pyo; Choi, Ehn-Kyoung; Rhee, Man Hee; Kim, Yun-Bae

2013-01-01

The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-depende...

Declotting a Thrombosed Brescia-Cimino Fistula by Manual Catheter-Directed Aspiration of the Thrombus

International Nuclear Information System (INIS)

Turmel-Rodrigues, Luc A

2005-01-01

Acute thrombosis of native fistulae for hemodialysis occurs more rarely than for prosthetic grafts. The vascular access should be reopened as soon as possible in order to resume regular dialysis and to avoid resorting to a temporary central line. Manual aspiration is one of the numerous methods described in this setting. Clinical examination is essential to rule out local infection, which is the only serious contraindication to percutaneous maneuvers. Two introducer-sheaths are placed in a criss-cross fashion in order to gain access to the venous outflow and to the anastomosis. Access to the venous outflow is performed first in order to check the proximal extent of the thrombosis. Heparin and antibiotics are injected systemically. A similar maneuver is then performed in the direction of the anastomosis. The aspiration phase is then initiated. A 7-9 Fr aspiration catheter is pushed through the 'venous' introducer. Manual aspiration is created through a 50 ml syringe while the catheter is progressively removed with back and forth movements. The catheter and the contents of the syringe are flushed through a gauze on the working table to evaluate the amount of thrombus which has been removed and the maneuver is repeated as often as necessary to remove all the thrombus. Once all the clots located downstream from the venous introducer have been removed, any unmasked underlying stenosis is NOT dilated at this stage since it provides protection against major embolism coming from the inflow. The aspiration catheter is then pushed through the 'arterial' introducer down to the anastomosis in order to aspirate the thrombus located between the tip of the introducer and the anastomosis. Dilatation of unmasked stenoses is finally performed using high-pressure balloons. The holes made by the two introducers are closed using a U-shaped suture with interposition of a short piece of plastic and the patient is sent back to the nephrologists for dialysis

Fibrin-Targeted Magnetic Resonance Imaging Allows In Vivo Quantification of Thrombus Fibrin Content and Identifies Thrombi Amenable for Thrombolysis

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Jenkins, Julia; Modarai, Bijan; Wiethoff, Andrea J.; Phinikaridou, Alkystis; Grover, Steven P.; Patel, Ashish S.; Schaeffter, Tobias; Smith, Alberto; Botnar, Rene M.

2014-01-01

Objective Deep venous thrombosis is a major health problem. Thrombolytic therapies are effective in recanalizing the veins and preventing post-thrombotic complications, but there is no consensus on selection criteria. The aim of this study was to investigate a fibrin-specific MRI contrast agent (EP-2104R) for the accurate quantification of thrombus’ fibrin content in vivo and for the identification of thrombus suitable for thrombolysis. Approach and Results Venous thrombosis was induced in the inferior vena cava of 8- to 10-week-old male BALB/C mice and MRI performed 2, 4, 7, 10, 14, and 21 days later. Eighteen mice were scanned at each time point pre and 2 hours post injection of EP-2104R (8.0 μmol/kg) with 12 mice at each time point used to correlate fibrin contrast uptake with thrombus’ histological stage and fibrin content. Six mice at each time point were immediately subjected to intravascular thrombolytic therapy (10 mg/kg of tissue-type plasminogen activator). Mice were imaged to assess response to lytic therapy 24 hours after thrombolytic treatment. Two mice at each time point were scanned post injection of 0.2 mmol/kg of Gd-DTPA (gadolinium with diethylenetriaminepentacetate, Magnevist, Schering AG, Berlin, Germany) for control purpose. Contrast uptake was correlated positively with the fibrin content of the thrombus measured by Western blotting (R2=0.889; PThrombus relaxation rate (R1) post contrast and the change in visualized thrombus size on late gadolinium enhancement inversion recovery MRI pre–EP-2104R and post–EP-2104R injection were the best predictors for successful thrombolysis (area under the curve, 0.989 [95% confidence interval, 0.97–1.00] and 0.994 [95% confidence interval, 0.98–1.00] respectively). Conclusions MRI with a fibrin-specific contrast agent accurately estimates thrombus fibrin content in vivo and identifies thrombi that are amenable for thrombolysis. PMID:24723557

MiR-34a deficiency accelerates medulloblastoma formation in vivo.

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Thor, Theresa; Künkele, Annette; Pajtler, Kristian W; Wefers, Annika K; Stephan, Harald; Mestdagh, Pieter; Heukamp, Lukas; Hartmann, Wolfgang; Vandesompele, Jo; Sadowski, Natalie; Becker, Lore; Garrett, Lillian; Hölter, Sabine M; Horsch, Marion; Calzada-Wack, Julia; Klein-Rodewald, Tanja; Racz, Ildiko; Zimmer, Andreas; Beckers, Johannes; Neff, Frauke; Klopstock, Thomas; De Antonellis, Pasqualino; Zollo, Massimo; Wurst, Wolfgang; Fuchs, Helmut; Gailus-Durner, Valérie; Schüller, Ulrich; de Angelis, Martin Hrabě; Eggert, Angelika; Schramm, Alexander; Schulte, Johannes H

2015-05-15

Previous studies have evaluated the role of miRNAs in cancer initiation and progression. MiR-34a was found to be downregulated in several tumors, including medulloblastomas. Here we employed targeted transgenesis to analyze the function of miR-34a in vivo. We generated mice with a constitutive deletion of the miR-34a gene. These mice were devoid of mir-34a expression in all analyzed tissues, but were viable and fertile. A comprehensive standardized phenotypic analysis including more than 300 single parameters revealed no apparent phenotype. Analysis of miR-34a expression in human medulloblastomas and medulloblastoma cell lines revealed significantly lower levels than in normal human cerebellum. Re-expression of miR-34a in human medulloblastoma cells reduced cell viability and proliferation, induced apoptosis and downregulated the miR-34a target genes, MYCN and SIRT1. Activation of the Shh pathway by targeting SmoA1 transgene overexpression causes medulloblastoma in mice, which is dependent on the presence and upregulation of Mycn. Analysis of miR-34a in medulloblastomas derived from ND2:SmoA1(tg) mice revealed significant suppression of miR-34a compared to normal cerebellum. Tumor incidence was significantly increased and tumor formation was significantly accelerated in mice transgenic for SmoA1 and lacking miR-34a. Interestingly, Mycn and Sirt1 were strongly expressed in medulloblastomas derived from these mice. We here demonstrate that miR-34a is dispensable for normal development, but that its loss accelerates medulloblastomagenesis. Strategies aiming to re-express miR-34a in tumors could, therefore, represent an efficient therapeutic option. © 2014 UICC.

Quasi-adiabatic particle acceleration in a magnetic field reversals and the formation of the plasma sheet boundary layer in the earth's magnetotail

International Nuclear Information System (INIS)

Zelenyi, L.M.; Vogin, D.V.; Buechner, J.

1989-01-01

Two types of regularity exist for the particle motion in the two-dimensional magnetic field reversals (MFR) with the strongly curves magnetic field lines - the usual adiabatic and another one which we called 'quasiadiabatic'. Here we consider the acceleration of MFR particles in stationary and homogeneous electric field induced by the motion of MFR through the ambient plasma (i.e. solar wind). Assuming that the time scale of acceleration is slow in comparison with the period of orbital motion we introduce the new longitudinal invariant I κ . This enables to describe the process of acceleration in a closed form and to obtain for the first time the laws governing the quasiadiabatic ion acceleration in the Earth's mangetotail. The similarities and differences in adiabatic and quasiadiabatic acceleration mechanisms are discussed. The obtained results give and important insights to the problem of the particle heating in hte Earth's magnetotail and to the formation of accelerated plasma streams along the edges of the plasma sheet. (author). 17 refs.; 7 figs

Identification and Management of Pump Thrombus in the HeartWare Left Ventricular Assist Device System: A Novel Approach Using Log File Analysis.

Science.gov (United States)

Jorde, Ulrich P; Aaronson, Keith D; Najjar, Samer S; Pagani, Francis D; Hayward, Christopher; Zimpfer, Daniel; Schlöglhofer, Thomas; Pham, Duc T; Goldstein, Daniel J; Leadley, Katrin; Chow, Ming-Jay; Brown, Michael C; Uriel, Nir

2015-11-01

The study sought to characterize patterns in the HeartWare (HeartWare Inc., Framingham, Massachusetts) ventricular assist device (HVAD) log files associated with successful medical treatment of device thrombosis. Device thrombosis is a serious adverse event for mechanical circulatory support devices and is often preceded by increased power consumption. Log files of the pump power are easily accessible on the bedside monitor of HVAD patients and may allow early diagnosis of device thrombosis. Furthermore, analysis of the log files may be able to predict the success rate of thrombolysis or the need for pump exchange. The log files of 15 ADVANCE trial patients (algorithm derivation cohort) with 16 pump thrombus events treated with tissue plasminogen activator (tPA) were assessed for changes in the absolute and rate of increase in power consumption. Successful thrombolysis was defined as a clinical resolution of pump thrombus including normalization of power consumption and improvement in biochemical markers of hemolysis. Significant differences in log file patterns between successful and unsuccessful thrombolysis treatments were verified in 43 patients with 53 pump thrombus events implanted outside of clinical trials (validation cohort). The overall success rate of tPA therapy was 57%. Successful treatments had significantly lower measures of percent of expected power (130.9% vs. 196.1%, p = 0.016) and rate of increase in power (0.61 vs. 2.87, p file parameters can potentially predict the likelihood of successful tPA treatments and if validated prospectively, could substantially alter the approach to thrombus management. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Combined MR direct thrombus imaging and non-contrast magnetic resonance venography reveal the evolution of deep vein thrombosis: a feasibility study

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Mendichovszky, I.A.; Lomas, D.J. [Addenbrooke' s Hospital, Department of Radiology, Cambridge (United Kingdom); University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Priest, A.N.; Bowden, D.J.; Hunter, S.; Joubert, I.; Hilborne, S.; Graves, M.J. [Addenbrooke' s Hospital, Department of Radiology, Cambridge (United Kingdom); Baglin, T. [Addenbrooke' s Hospital, Department of Haematology, Cambridge (United Kingdom)

2017-06-15

Lower limb deep venous thrombosis (DVT) is a common condition with high morbidity and mortality. The aim of the study was to investigate the temporal evolution of the acute thrombus by magnetic resonance imaging (MRI) and its relationship to venous recanalization in patients with recurrent DVTs. Thirteen patients with newly diagnosed lower limb DVTs underwent MRI with non-contrast MR venography (NC-MRV) and MR direct thrombus imaging (MR-DTI), an inversion-recovery water-selective fast gradient-echo acquisition. Imaging was performed within 7 days of the acute thrombotic event, then at 3 and 6 months. By 3 months from the thrombotic event a third of the thrombi had resolved and by 6 months about half of the cases had resolved on the basis of vein recanalisation using NC-MRV. On the initial MR-DTI acute thrombus was clearly depicted by hyperintense signal, while the remaining thrombi were predominantly low signal at 3 and 6 months. Some residual thrombi contained small and fragmented persisting hyperintense areas at 3 months, clearing almost completely by 6 months. Our study suggests that synergistic venous assessment with combined NC-MRV and MR-DTI is able to distinguish acute venous thrombosis from the established (old) or evolving DVT detected by ultrasound. (orig.)

Combined MR direct thrombus imaging and non-contrast magnetic resonance venography reveal the evolution of deep vein thrombosis: a feasibility study

International Nuclear Information System (INIS)

Mendichovszky, I.A.; Lomas, D.J.; Priest, A.N.; Bowden, D.J.; Hunter, S.; Joubert, I.; Hilborne, S.; Graves, M.J.; Baglin, T.

2017-01-01

Lower limb deep venous thrombosis (DVT) is a common condition with high morbidity and mortality. The aim of the study was to investigate the temporal evolution of the acute thrombus by magnetic resonance imaging (MRI) and its relationship to venous recanalization in patients with recurrent DVTs. Thirteen patients with newly diagnosed lower limb DVTs underwent MRI with non-contrast MR venography (NC-MRV) and MR direct thrombus imaging (MR-DTI), an inversion-recovery water-selective fast gradient-echo acquisition. Imaging was performed within 7 days of the acute thrombotic event, then at 3 and 6 months. By 3 months from the thrombotic event a third of the thrombi had resolved and by 6 months about half of the cases had resolved on the basis of vein recanalisation using NC-MRV. On the initial MR-DTI acute thrombus was clearly depicted by hyperintense signal, while the remaining thrombi were predominantly low signal at 3 and 6 months. Some residual thrombi contained small and fragmented persisting hyperintense areas at 3 months, clearing almost completely by 6 months. Our study suggests that synergistic venous assessment with combined NC-MRV and MR-DTI is able to distinguish acute venous thrombosis from the established (old) or evolving DVT detected by ultrasound. (orig.)

Extraluminal venous interruption for free-floating thrombus in the deep veins of lower limbs.

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Casian, D; Gutsu, E; Culiuc, V

2010-01-01

The free-floating thrombus (FFT) represents a particular form of deep vein thrombosis with extremely high potential of fatal pulmonary embolism. The purpose of the study was to evaluate the early results of aggressive surgical approach to FFT. During the period 2005-2008 years FFT was diagnosed in 13 patients. Demographic characteristics of patients: medium age--54.7 years, male--76.9%, significant comorbidity--5 (38.5%) cases. Localization of FFT: superficial femoral vein (SFV)--5 (38.5%), common femoral vein (CFV)--4 (30.7%), external iliac vein (EIV)--2 (15.4%), inferior cava vein (ICV)--2 (15.4%). Manifestations of previous pulmonary embolism were documented preoperatively in 3 (23.1%) cases. The following emergency surgical procedures were performed: ligation--3 (23.1%) or plication--2 (15.4%) of SFV; plication of CFV--5 (38.5%) patients, combined in 4 cases with partial thrombectomy (free-floating part of thrombus); plication of common iliac vein--1 (7.6%); plication of ICV--2 (15.4%) cases. Primary or recurrent cases of clinically significant pulmonary embolism were not detected in the postoperative period. The accumulated experience of surgical management of patients with FFT reveals the important role of deep vein ligation/plication in prevention of fatal pulmonary embolism.

ACCELERATORS: School prizes

International Nuclear Information System (INIS)

Anon.

1987-01-01

Dedicated to its goal of encouraging scientists and students to work in the field of particle accelerators, the US Particle Accelerator School (operating since 1981) has switched to a new format. Starting this year, it will offer in alternate years basic accelerator physics plus advanced subjects in both university and symposium styles over four weeks. Expanding the school from two to four weeks gives additional flexibility, and undergraduate participation should be encouraged by university credits being offered for particular courses. In the intervening years, the school will organize six-day topical courses

The formation of kappa-distribution accelerated electron populations in solar flares

Energy Technology Data Exchange (ETDEWEB)

Bian, Nicolas H.; Stackhouse, Duncan J.; Kontar, Eduard P. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Emslie, A. Gordon, E-mail: n.bian@physics.gla.ac.uk, E-mail: d.stackhouse.1@research.gla.ac.uk, E-mail: eduard@astro.gla.ac.uk, E-mail: emslieg@wku.edu [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101 (United States)

2014-12-01

Driven by recent RHESSI observations of confined loop-top hard X-ray sources in solar flares, we consider stochastic acceleration of electrons in the presence of Coulomb collisions. If electron escape from the acceleration region can be neglected, the electron distribution function is determined by a balance between diffusive acceleration and collisions. Such a scenario admits a stationary solution for the electron distribution function that takes the form of a kappa distribution. We show that the evolution toward this kappa distribution involves a 'wave front' propagating forward in velocity space, so that electrons of higher energy are accelerated later; the acceleration timescales with energy according to τ{sub acc} ∼ E {sup 3/2}. At sufficiently high energies escape from the finite-length acceleration region will eventually dominate. For such energies, the electron velocity distribution function is obtained by solving a time-dependent Fokker-Planck equation in the 'leaky-box' approximation. Solutions are obtained in the limit of a small escape rate from an acceleration region that can effectively be considered a thick target.

On the Impact of Intraluminal Thrombus Mechanical Behavior in AAA Passive Mechanics.

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Riveros, Fabián; Martufi, Giampaolo; Gasser, T Christian; Rodriguez-Matas, Jose F

2015-09-01

Intraluminal thrombus (ILT) is a pseudo-tissue that develops from coagulated blood, and is found in most abdominal aortic aneurysms (AAAs) of clinically relevant size. A number of studies have suggested that ILT mechanical characteristics may be related to AAA risk of rupture, even though there is still great controversy in this regard. ILT is isotropic and inhomogeneous and may appear as a soft (single-layered) or stiff (multilayered fibrotic) tissue. This paper aims to investigate how ILT constitution and topology influence the magnitude and location of peak wall stress (PWS). In total 21 patient-specific AAAs (diameter 4.2-5.4 cm) were reconstructed from computer tomography images and biomechanically analyzed using state-of-the-art modeling assumptions. Results indicated that PWS correlated stronger with ILT volume (ρ = 0.44, p = 0.05) and minimum thickness of ILT layer (ρ = 0.73, p = 0.001) than with maximum AAA diameter (ρ = 0.05, p = 0.82). On average PWS was 20% (SD 12%) higher for FE models that used soft instead of stiff ILT models (p AAA diameter and was independent from ILT stiffness. In addition, ILT heterogeneity, i.e., the spatial composition of soft and stiff thrombus tissue, can considerably influence stress in the AAA wall. The present study is limited to identification of influential biomechanical factors, and how its findings translate to an AAA rupture risk assessment remains to be explored by clinical studies.

Radiolabelled anti-human fibrin antibody: a new thrombus-detecting agent

International Nuclear Information System (INIS)

Bosnjakovic, V.; Jankovic, B.D.; Horvat, J.; Cvoric, J.

1977-01-01

Rabbit anti-human fibrin globulin (A.F.G.) was labelled with iodine ( 131 I) and used as a thrombus-detecting agent. 131 I-A.F.G. labelled thrombi were displayed by means of a gamma scintillation camera. Normal subjects and patients with thrombo-phlebitis of legs, acute fibrin depositions other than thrombi, and chronic varicosities were examined. The 131 I-A.F.G. technique detected both formed thrombi and those that were forming and could discriminate between acute thrombosis and chronic varicosities. Thrombo-phlebitis and extravascular fibrin depositions were best demonstrated between 24 and 72 hours after 131 I-A.F.G. injection. Radiolabelled A.F.G. in normal veins and chronic varicosities was best displayed within 6 hours of injection. (author)

Results from the RACE [Ring ACceleration Experiment] Compact Torus Acceleration Experiment

International Nuclear Information System (INIS)

Hammer, J.H.; Hartman, C.W.; Eddleman, J.L.; Kusse, B.

1987-06-01

RACE (Ring ACceleration Experiment) is a proof-of-principle experiment aimed at demonstrating acceleration of magnetically confined compact torus plasma rings to directed kinetic energies well in excess of their magnetic and thermal energies. In the course of the first year of operation the following have been observed: successful formation of rings in the RACE geometry; acceleration of rings with large forces, F/sub accelerate/ ∼F/sub equilibrium/ without apparent degradation of the ring structure; peak velocities of ≅2.5 x 10 8 cm/sec; acceleration efficiency of >30% at speeds of 1.5 x 10 8 cm/sec inferred from trajectory and capacitor bank data; kinetic to magnetic energy ratios ∼10 were observed. Experiments in the near future will be aimed at confirmation of the mass/energy measurements by calorimetry and direct density measurements

Early thrombus removal strategies for acute deep venous thrombosis: clinical practice guidelines of the Society for Vascular Surgery and the American Venous Forum.

Science.gov (United States)

Meissner, Mark H; Gloviczki, Peter; Comerota, Anthony J; Dalsing, Michael C; Eklof, Bo G; Gillespie, David L; Lohr, Joann M; McLafferty, Robert B; Murad, M Hassan; Padberg, Frank; Pappas, Peter; Raffetto, Joseph D; Wakefield, Thomas W

2012-05-01

The anticoagulant treatment of acute deep venous thrombosis (DVT) has been historically directed toward the prevention of recurrent venous thromboembolism. However, such treatment imperfectly protects against late manifestations of the postthrombotic syndrome. By restoring venous patency and preserving valvular function, early thrombus removal strategies can potentially decrease postthrombotic morbidity. A committee of experts in venous disease was charged by the Society for Vascular Surgery and the American Venous Forum to develop evidence-based practice guidelines for early thrombus removal strategies, including catheter-directed pharmacologic thrombolysis, pharmacomechanical thrombolysis, and surgical thrombectomy. Evidence-based recommendations are based on a systematic review and meta-analysis of the relevant literature, supplemented when necessary by less rigorous data. Recommendations are made according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, incorporating the strength of the recommendation (strong: 1; weak: 2) and an evaluation of the level of the evidence (A to C). On the basis of the best evidence currently available, we recommend against routine use of the term "proximal venous thrombosis" in favor of more precise characterization of thrombi as involving the iliofemoral or femoropopliteal venous segments (Grade 1A). We further suggest the use of early thrombus removal strategies in ambulatory patients with good functional capacity and a first episode of iliofemoral DVT of venous outflow obstruction (Grade 1A). We suggest pharmacomechanical strategies over catheter-directed pharmacologic thrombolysis alone if resources are available and that surgical thrombectomy be considered if thrombolytic therapy is contraindicated (Grade 2C). Most data regarding early thrombus removal strategies are of low quality but do suggest patient-important benefits with respect to reducing postthrombotic morbidity. We

Thrombus imaging with indium-111 and iodine-131-labeled fibrin-specific monoclonal antibody and its F(ab')2 and Fab fragments

International Nuclear Information System (INIS)

Rosebrough, S.F.; Grossman, Z.D.; McAfee, J.G.

1988-01-01

We have previously reported successful imaging of fresh (2-4 hr old) and aged (1-5 days old) canine thrombi with 131 I-labeled intact monoclonal antibody (MAb) specific for fibrin. We now report thrombus imaging with 131 I-labeled F(ab')2 and Fab and 111 In-labeled intact MAb, F(ab')2, and Fab. Indium-111-labeled F(ab')2 proved to be the best imaging agent due to less nonspecific binding in the liver than whole IgG. Image quality was improved by the higher administered dose permissible with 111 In and its better physical characteristics for imaging, compared to 131 I. Immunofluorescence of fresh human histologic sections showed intact MAb and F(ab')2 binding to thrombi, pulmonary emboli, and atherosclerotic plaques, strengthening the feasibility of clinical thrombus imaging

Tanshinon IIA injection accelerates tissue expansion by reducing the formation of the fibrous capsule.

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Yu, Qingxiong; Sheng, Lingling; Yang, Mei; Zhu, Ming; Huang, Xiaolu; Li, Qingfeng

2014-01-01

The tissue expansion technique has been applied to obtain new skin tissue to repair large defects in clinical practice. The implantation of tissue expander could initiate a host response to foreign body (FBR), which leads to fibrotic encapsulation around the expander and prolongs the period of tissue expansion. Tanshinon IIA (Tan IIA) has been shown to have anti-inflammation and immunoregulation effect. The rat tissue expansion model was used in this study to observe whether Tan IIA injection systematically could inhibit the FBR to reduce fibrous capsule formation and accelerate the process of tissue expansion. Forty-eight rats were randomly divided into the Tan IIA group and control group with 24 rats in each group. The expansion was conducted twice a week to maintain a capsule pressure of 60 mmHg. The expansion volume and expanded area were measured. The expanded tissue in the two groups was harvested, and histological staining was performed; proinflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) and transforming growth factor-β (TGF-β) were examined. The expansion volume and the expanded area in the Tan IIA group were greater than that of the control group. The thickness of the fibrous capsule in the Tan IIA group was reduced with no influence on the normal skin regeneration. Decreased infiltration of macrophages, lower level of TNF-α, IL-6, IL-1β and TGF-β, less proliferating myofibroblasts and enhanced neovascularization were observed in the Tan IIA group. Our findings indicated that the Tan IIA injection reduced the formation of the fibrous capsule and accelerated the process of tissue expansion by inhibiting the FBR.

Tanshinon IIA injection accelerates tissue expansion by reducing the formation of the fibrous capsule.

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Qingxiong Yu

Full Text Available The tissue expansion technique has been applied to obtain new skin tissue to repair large defects in clinical practice. The implantation of tissue expander could initiate a host response to foreign body (FBR, which leads to fibrotic encapsulation around the expander and prolongs the period of tissue expansion. Tanshinon IIA (Tan IIA has been shown to have anti-inflammation and immunoregulation effect. The rat tissue expansion model was used in this study to observe whether Tan IIA injection systematically could inhibit the FBR to reduce fibrous capsule formation and accelerate the process of tissue expansion. Forty-eight rats were randomly divided into the Tan IIA group and control group with 24 rats in each group. The expansion was conducted twice a week to maintain a capsule pressure of 60 mmHg. The expansion volume and expanded area were measured. The expanded tissue in the two groups was harvested, and histological staining was performed; proinflammatory cytokines such as tumor necrosis factor-α (TNF-α, interleukin-6 (IL-6 and interleukin-1β (IL-1β and transforming growth factor-β (TGF-β were examined. The expansion volume and the expanded area in the Tan IIA group were greater than that of the control group. The thickness of the fibrous capsule in the Tan IIA group was reduced with no influence on the normal skin regeneration. Decreased infiltration of macrophages, lower level of TNF-α, IL-6, IL-1β and TGF-β, less proliferating myofibroblasts and enhanced neovascularization were observed in the Tan IIA group. Our findings indicated that the Tan IIA injection reduced the formation of the fibrous capsule and accelerated the process of tissue expansion by inhibiting the FBR.

Sonothrombolysis

Science.gov (United States)

Bader, Kenneth B.; Bouchoux, Guillaume

2016-01-01

Thrombo-occlusive disease is a leading cause of morbidity and mortality. In this chapter, the use of ultrasound to accelerate clot breakdown alone or in combination with thrombolytic drugs will be reported. Primary thrombus formation during cardiovascular disease and standard treatment methods will be discussed. Mechanisms for ultrasound enhancement of thrombolysis, including thermal heating, radiation force, and cavitation, will be reviewed. Finally, in-vitro, in-vivo and clinical evidence of enhanced thrombolytic efficacy with ultrasound will be presented and discussed. PMID:26486347

Nonbacterial thrombotic endocarditis associated with cancer of unknown origin complicated with thrombus in the left auricular appendage: case report

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Morinaga Yukiko

2011-02-01

Full Text Available Abstract A 63-year-old man was admitted to our hospital with a complaint of right lateroabdominal pain. He was diagnosed with metastatic colon cancer, and then developed multiple brain embolic infarctions 7 days after admission. Transesophageal echocardiography showed that mobile, echo-dense masses were attached to the anterior and posterior mitral valve leaflet. Furthermore, there was a thrombus in the left auricular appendage despite sinus rhythm. These findings led to a diagnosis of suspected infectious endocarditis with subsequent multiple brain infarctions. The patient's general condition worsened and he died 13 days after admission. An autopsy was performed, and, while poorly differentiated cancer was observed in multiple organs, no primary tumor could be identified. Histological analysis showed that the masses of the mitral valve consisted mainly of fibrin without bacteria or oncocytes. This patient was therefore diagnosed with nonbacterial thrombotic endocarditis associated with cancer of unknown origin complicated with thrombus in the left auricular appendage.

Influence of solidification accelerators on structure formation of anhydrite-containing binders

Energy Technology Data Exchange (ETDEWEB)

Anikanova, L., E-mail: alasmit@mail.ru; Volkova, O., E-mail: v.olga.nikitina@gmail.com; Kudyakov, A.; Sarkisov, Y.; Tolstov, D. [Tomsk State University of Architecture and Building, 2 Solyanaya sq., Tomsk, 634003 (Russian Federation)

2016-01-15

The article presents results of scientific analysis of chemical additives influence on acid fluoride binder. It was found that the influence of sulfate nature additives on the process of hydration and solidification of the binder is similar to influence of additives on indissoluble anhydrite. Additives with SO{sub 4}{sup 2−} anion NO{sup −} are more efficient. The mentioned additives according to accelerating effect belong to the following succession: K{sub 2}SO{sub 4} > Na{sub 2}SO{sub 4} > FeSO{sub 4} > MgSO{sub 4}. Facilitation of the process of hydration and solidification of the binder, increase in density and durability of the binder (32 MPa) is to the greatest extent achieved with the introduction of 2% sodium sulfate additive of the binder’s mass into the composition of the binder along with the ultrasonic treatment of water solution. Directed crystal formation process with healing of porous structure by new growths presented as calcium sulfate dehydrate and hydroglauberite provides positive effect.

Influence of Tumor Thrombus Location on the Outcome of External-beam Radiation Therapy in Advanced Hepatocellular Carcinoma With Macrovascular Invasion

Energy Technology Data Exchange (ETDEWEB)

Hou Jiazhou [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Zeng Zhaochong, E-mail: zeng.zhaochong@zs-hospital.sh.cn [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Zhang Jianying [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Fan Jia; Zhou Jian [Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Zeng Mengsu [Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai 200032 (China)

2012-10-01

Purpose: The present study evaluates the influence of portal vein (PV) vs. inferior vena cava (IVC) tumor thrombosis sites on the effectiveness of external-beam radiation therapy (EBRT) in advanced hepatocellular carcinoma (HCC) with macrovascular invasion. Methods and Materials: We retrospectively reviewed 181 HCC patients with PV and/or IVC tumor thrombi who were referred for EBRT at our institution between 2000 and 2009. EBRT was designed to focus on the tumor thrombi with or without primary intrahepatic tumors to deliver a median total conventional dose of 50 Gy (range, 30-60 Gy). Predictors of survival were identified using univariate and multivariate analyses. Results: The median survival was 10.2, 7.4, 17.4, and 8.5 months for patients with PV branch, PV trunk, IVC, and PV plus IVC tumor thrombosis, respectively. Unfavorable pretreatment predictors were associated by multivariate analysis with lower albumin and higher {alpha}-fetoprotein levels, poorer Child-Pugh liver function classification, multiple intrahepatic foci, lymph node metastases, thrombus location, less chance to receive post-EBRT transarterial chemoembolization (TACE) and the two-dimensional EBRT technique. In comparison to patients with PV tumor thrombosis, patients with IVC thrombi had a higher occurrence of solitary intrahepatic lesions (p = 0.027), well-controlled intrahepatic tumors (p < 0.001), and a better response to EBRT (p < 0.001), and they were more likely to receive post-EBRT TACE (p = 0.033). Conclusions: In HCC, patients with IVC thrombus treated with EBRT had a better response rate and longer survival than those with PV thrombus.

Differentiation of thrombus from pannus as the cause of acquired mechanical prosthetic heart valve obstruction by non-invasive imaging: a review of the literature.

Science.gov (United States)

Tanis, Wilco; Habets, Jesse; van den Brink, Renee B A; Symersky, Petr; Budde, Ricardo P J; Chamuleau, Steven A J

2014-02-01

For acquired mechanical prosthetic heart valve (PHV) obstruction and suspicion on thrombosis, recently updated European Society of Cardiology guidelines advocate the confirmation of thrombus by transthoracic echocardiography, transesophageal echocardiography (TEE), and fluoroscopy. However, no evidence-based diagnostic algorithm is available for correct thrombus detection, although this is clinically important as fibrinolysis is contraindicated in non-thrombotic obstruction (isolated pannus). Here, we performed a review of the literature in order to propose a diagnostic algorithm. We performed a systematic search in Pubmed and Embase. Included publications were assessed on methodological quality based on the validated Quality Assessment of Diagnostic Accuracy Studies (QUADAS) II checklist. Studies were scarce (n = 15) and the majority were of moderate methodological quality. In total, 238 mechanical PHV's with acquired obstruction and a reliable reference standard were included for the evaluation of the role of fluoroscopy, echocardiography, or multidetector-row computed tomography (MDCT). In acquired PHV obstruction caused by thrombosis, mass detection by TEE and leaflet restriction detected by fluoroscopy were observed in the majority of cases (96 and 100%, respectively). In contrast, in acquired PHV obstruction free of thrombosis (pannus), leaflet restriction detected by fluoroscopy was absent in some cases (17%) and mass detection by TEE was absent in the majority of cases (66%). In case of mass detection by TEE, predictors for obstructive thrombus masses (compared with pannus masses) were leaflet restriction, soft echo density, and increased mass length. In situations of inconclusive echocardiography, MDCT may correctly detect pannus/thrombus based on the morphological aspects and localization. In acquired mechanical PHV obstruction without leaflet restriction and absent mass on TEE, obstructive PHV thrombosis cannot be confirmed and consequently, fibrinolysis

Early enriched environment exposure protects spatial memory and accelerates amyloid plaque formation in APP(Swe/PS1(L166P mice.

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Francesca Montarolo

Full Text Available Enriched environment exposure improves several aspects of cognitive performance in Alzheimer's disease patients and in animal models and, although the role of amyloid plaques is questionable, several studies also assessed their response to enriched environment, with contrasting results. Here we report that rearing APP(Swe/PS1(L166P mice in an enriched environment since birth rescued the spatial memory impairment otherwise present at 6 months of age. At the same time, the exposure to the enriched environment caused a transient acceleration of plaque formation, while there was no effect on intracellular staining with the 6E10 antibody, which recognizes β-amyloid, full length amyloid precursor protein and its C-terminal fragments. The anticipation of plaque formation required exposure during early development, suggesting an action within critical periods for circuits formation. On the other hand, chronic neuronal activity suppression by tetrodotoxin decreased the number of plaques without affecting intracellular amyloid. These results indicate that enriched environment exposure since early life has a protective effect on cognitive deterioration although transiently accelerates amyloid deposition. In addition, the effects of the enriched environment might be due to increased neuronal activity, because plaques were reduced by suppression of electrical signaling by tetrodotoxin.

Interventional treatment for old thrombus in iliofemoral deep veins

International Nuclear Information System (INIS)

Qian Jun; Jiang Hong; Yang Yang

2009-01-01

Objective: To evaluate interventional management in treating old thrombus in iliofemoral deep veins. Methods: The clinical data and the interventional treatment results of 32 patients with chronic iliofemoral deep venous thrombosis were retrospectively reviewed and analyzed. Results: Technical success was achieved in 30 patients (93.8%). Twenty-nine endovascular stents were successfully placed in 25 patients. Postoperative therapeutic effects were as follows: grade I was obtained in 4 cases (12.5%), grade II in 16 cases (50.0%), grade III in 10 cases (31.3%) and grade IV in 2 cases (6.3%). Twenty-nine patients were followed-up for a mean period of 13.0 ± 6.8 months, and three patients were lost in touch. The follow-up results were as follows: grade I was seen in 3 cases (10.3%), grade II in 14 cases (48.3%) and grade III in 12 cases (41.4%). Conclusion: Interventional management is a minimally-invasive, safe and effective treatment for chronic iliofemoral deep venous thrombosis. (authors)

Biventricular thrombus in hypereosinophilic syndrome presenting with shortness of breath

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Abdul Baqi

2016-06-01

Full Text Available A 48 years old male presented to clinic with 12 months of low grade fever with shortness of breath which has progressively worsened with no associated weight loss, night sweats or loss of appetite. There was no prior history of chronic illness before the current illness. Laboratory workup revealed a high white blood cell count with predominant eosinophils. Chest X-ray was normal. Transthoracic echocardiography and Cardiac Magnetic Resonance showed biventricular thrombi. On further extensive workup the findings were consistent with hypereosinophilic syndrome. The patient was started on oral steroids, hydroxyurea, imatanib mesylate and oral anticoagulation. The patient responded to the treatment with complete resolution of his symptoms over the course of few months. The repeat Echocardiogram after a year showed normal left ventricular systolic and diastolic function with complete resolution of biventricular thrombi. Keywords: Hypereosinophilic syndrome, Thrombus

Histopathologic composition of cerebral thrombi of acute stroke patients is correlated with stroke subtype and thrombus attenuation.

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Joris M Niesten

Full Text Available INTRODUCTION: We related composition of cerebral thrombi to stroke subtype and attenuation on non-contrast CT (NCCT to gain more insight in etiopathogenesis and to validate thrombus attenuation as a new imaging biomarker for acute stroke. METHODS: We histopathologically investigated 22 thrombi retrieved after mechanical thrombectomy in acute stroke patients. First, thrombi were classified as fresh, lytic or organized. Second, percentages of red blood cells (RBCs, platelets and fibrin and number of red, white (respectively RBCs or platelets outnumbering other components with ≥ 15% or mixed thrombi were compared between large artery atherosclerosis (LAA, cardioembolism, dissection and unknown subtype. Third, correlation between attenuation and RBCs, platelets and fibrin was calculated using Pearson's correlation coefficients (r. RESULTS: Thrombi were fresh in 73% (n = 16, lytic in 18% (n = 4 and organized in 9% (n = 2. The stroke cause was LAA in eight (36%, cardioembolism in six (27%, dissection in three (14%, and unknown in five (23% patients. LAA thrombi showed the highest percentage RBCs (median 50 (range 35-90, followed by dissection (35 (20-40, p = 0.05, cardioembolism (35 (5-45, p = 0.013 and unknown subtype (25 (2-40, p = 0.006. No differences in platelets (p = 0.16 and fibrin (p = 0.52 between subtypes were found. LAA thrombi were classified as red or mixed (both n = 4, cardioembolisms as mixed (n = 5 or white (n = 1 and dissection as mixed (n = 3. There was a moderate positive correlation between attenuation and RBCs (r = 0.401, p = 0.049, and weak negative correlations with platelets (r = -0.368, p = 0.09 and fibrin (r = -0.073, p = 0.75. CONCLUSIONS: The majority of cerebral thrombi is fresh. There are no differences in age of thrombi between subtypes. LAA thrombi have highest percentages RBCs, cardioembolism and unknown subtype lowest. No relationship exists between subtype and platelets or fibrin percentages. We found a

Hemorrhagic Cardioembolic Stroke Secondary to a Left Ventricular Thrombus: a Therapeutic Dilemma

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Khalil Al-Farsi

2013-01-01

Full Text Available Cardiogenic embolism is a major cause of stroke and often leads to significant morbidity and mortality. Despite the recent advances in our understanding of the pathophysiology of stroke and its risk factors, diagnosis and therapy; some case scenarios still present a real challenge for the treating physicians. We report a case of a 50 year old male patient presenting with multi-territory cerebral infarctions due to a left ventricular mobile thrombus complicated with hemorrhagic transformation at the time of presentation. Gradual introduction of anticoagulation coupled with a multidisciplinary team approach advocating careful daily clinical assessment of the patient and regular echocardiographic and neuroimaging studies have resulted in a better management and achievement of therapeutic goals.

Investigation of the thrombin-generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days.

Science.gov (United States)

Johansson, P I; Svendsen, M S; Salado, J; Bochsen, L; Kristensen, A T

2008-02-01

Transfusion based on the Thrombelastograph (TEG) results reduces transfusion requirements in cardiac surgery and in liver transplantation. Taking the pivotal role of thrombin generation in the coagulation process into consideration, the clinical utility of the TEG may, in part, depend on its reflection of the dynamics of thrombin generation. The kinetics of thrombin generation of platelets stored for 2 and 7 days, respectively, was assessed by calibrated automated thrombogram (CAT) and the lag time (min), time to peak (ttPeak; min), peak (nm thrombin) and endogenous thrombin potential (ETP; nm thrombin*min) were registered. Clot formation was evaluated by TEG and the R time (min), maxial amplitude (MA; mm), time to maximum thrombus generation (TMG; min) and maximum thrombus generation (MTG; dynes cm(-2) s(-1)) and total thrombus generation (TTG; dyne cm(-2)) were registered. Platelets become more procoagulant, evaluated both by TEG and CAT during storage. The reduction in CAT lag time and the ttPeak correlated with a decrease in the TEG R time and TMG (P < 0.0001) as did the CAT peak thrombin generation and the TEG MTG (P = 0.0035). No correlation between ETP and TTG was found (P = 0.65). The kinetics of thrombin generation, as evaluated by CAT, correlates with the thrombus generation, as evaluated by thrombelastography and this may in part explain the clinical utility of the TEG in identifying clinically relevant coagulopathies, secondary to impaired thrombin generation.

An Abdominal Aortic Aneurysm, Intramural Thrombus and Moderate Leak in an Asian Man Presenting with Acute Gastroenteritis

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Abdalla Khalil

2017-11-01

Full Text Available Introduction: Missing a leaking abdominal aortic aneurysm (AAA is common in medical practice because few at-risk patients have a history of AAA and many have an unusual presentation. Background: AAA is less common among Asians than white Caucasians of the same age. Our patient had no significant risk factors apart from age and sex and had an unusual presentation. Patient and Methods: A 67-year-old Asian man presented to the emergency room (ER with a 1-day history of nausea, vomiting, diarrhoea, fever and abdominal pain. He was febrile, dehydrated. and had marked tenderness at the right iliac fossa. Laboratory findings suggested bacterial gastroenteritis but this did not explain the localized tenderness at the right iliac fossa. Result and Discussion: A CT scan of the abdomen revealed an AAA arising above the origins of the renal arteries, an intramural thrombus, a retroperitoneal haematoma and a leak extending to the right iliac fossa. The patient was transferred to another hospital and underwent exploratory laparotomy, surgical repair of the aneurysm, and aortobi-iliac grafting with removal of the thrombus. The patient was discharged in good shape 3 weeks after surgery. Without the CT scan of the abdomen, the AAA could have been missed and the patient treated for severe gastroenteritis.

Theory of aurora formation

International Nuclear Information System (INIS)

Hasegawa, Akira.

1975-04-01

A new theory of aurora formation is presented based on Alfven wave-electron interaction. The theory explains consistently 1) the electron acceleration process, 2) the formation of auroral layers and 3) the long wave formation in the longitudinal direction. (auth.)

Circular induction accelerator for borehole logging

International Nuclear Information System (INIS)

Chen, F.K.; Bertozzi, W.; Corris, G.W.; Diamond, W.; Doucet, J.A.; Schweitzer, J.S.

1992-01-01

This patent describes a downhole logging sonde adapted to be moved through a borehole, a source of gamma rays in the sonde for irradiating earth formations traversed by the borehole, one or more gamma ray detectors for detecting gamma rays scattered back to the sonde from the irradiated earth formations, and means for transmitting signals representative of the detected gamma rays to the earth's surface for processing. This patent describes improvement in the gamma ray source comprises a magnetic induction particle accelerator, including: a magnetic circuit having a field magnet, generally circular opposed pole pieces, and a core magnet metal ions from the group consisting of Mn, Zn and Ni; an excitation circuit including a field coil surrounding the field magnet and the core magnet and a core coil surrounding the central axially leg of the core magnet; an annular acceleration chamber interposed between the pole pieces; means for applying time-varying acceleration voltage pulses across the primary excitation circuit; means for injecting charged particles into orbit within the acceleration chamber; means for compressing the particle orbits to trap particles within generally circular orbits within the acceleration chamber; means for generating a particle accelerating magnetic flux in the magnetic circuit; and means for ejecting charged particles from the generally circular orbits and into contact with a target to produce gamma ray photons

Differentiation of thrombus from pannus as the cause of acquired mechanical prosthetic heart valve obstruction by non-invasive imaging: a review of the literature

NARCIS (Netherlands)

Tanis, Wilco; Habets, Jesse; van den Brink, Renee B. A.; Symersky, Petr; Budde, Ricardo P. J.; Chamuleau, Steven A. J.

2014-01-01

For acquired mechanical prosthetic heart valve (PHV) obstruction and suspicion on thrombosis, recently updated European Society of Cardiology guidelines advocate the confirmation of thrombus by transthoracic echocardiography, transesophageal echocardiography (TEE), and fluoroscopy. However, no

Effects of Intraluminal Thrombus on Patient-Specific Abdominal Aortic Aneurysm Hemodynamics via Stereoscopic Particle Image Velocity and Computational Fluid Dynamics Modeling

Science.gov (United States)

Chen, Chia-Yuan; Antón, Raúl; Hung, Ming-yang; Menon, Prahlad; Finol, Ender A.; Pekkan, Kerem

2014-01-01

The pathology of the human abdominal aortic aneurysm (AAA) and its relationship to the later complication of intraluminal thrombus (ILT) formation remains unclear. The hemodynamics in the diseased abdominal aorta are hypothesized to be a key contributor to the formation and growth of ILT. The objective of this investigation is to establish a reliable 3D flow visualization method with corresponding validation tests with high confidence in order to provide insight into the basic hemodynamic features for a better understanding of hemodynamics in AAA pathology and seek potential treatment for AAA diseases. A stereoscopic particle image velocity (PIV) experiment was conducted using transparent patient-specific experimental AAA models (with and without ILT) at three axial planes. Results show that before ILT formation, a 3D vortex was generated in the AAA phantom. This geometry-related vortex was not observed after the formation of ILT, indicating its possible role in the subsequent appearance of ILT in this patient. It may indicate that a longer residence time of recirculated blood flow in the aortic lumen due to this vortex caused sufficient shear-induced platelet activation to develop ILT and maintain uniform flow conditions. Additionally, two computational fluid dynamics (CFD) modeling codes (Fluent and an in-house cardiovascular CFD code) were compared with the two-dimensional, three-component velocity stereoscopic PIV data. Results showed that correlation coefficients of the out-of-plane velocity data between PIV and both CFD methods are greater than 0.85, demonstrating good quantitative agreement. The stereoscopic PIV study can be utilized as test case templates for ongoing efforts in cardiovascular CFD solver development. Likewise, it is envisaged that the patient-specific data may provide a benchmark for further studying hemodynamics of actual AAA, ILT, and their convolution effects under physiological conditions for clinical applications. PMID:24316984

Effect of cause of iliac vein stenosis and extent of thrombus in the lower extremity on patency of iliac venous stent placed after catheter-directed thrombolysis of acute deep venous thrombosis in the lower extremity

International Nuclear Information System (INIS)

Jung, Sung Il; Choi, Young Ho; Yoon, Chang Jin; Lee, Min Woo; Chung, Jin Wook; Park, Jae Hyung

2003-01-01

To assess the CT findings of acute deep venous thrombosis (DVT) in a lower extremity prior to catheter-directed thrombolysis, and to evaluate their relevance to the patency of an iliac venous stent placed with the help of CT after catheter-directed thrombolysis of DVT. Fourteen patients [M:F=3:11; age, 33-68 (mean, 50.1) years] with acute symptomatic DVD of a lower extremity underwent CT before and after catheter-directed thrombolysis using an iliac venous stent. The mean duration of clinical symptoms was 5.0 (range, 1-14 days. The CT findings prior to thrombolysis were evaluated in terms of their anatomic cause and the extent of the thrombus, and in all patients, the patency of the iliac venous stent was assessed at CT performed during a follow-up period lasting 6-31 (mean, 18.9) months. All patients were assigned to the patent stent group (n=9) or the occluded stent group (n=5). In the former, the anatomic cause of patency included typical iliac vein compression (May-Thurner syndrome) (n=9), and a relatively short segmental thrombus occurring between the common iliac and the popliteal vein (n=8). Thrombi occurred in the iliac vein (n=3), between the common iliac and the femoral vein (n=3), and between the common iliac and the popliteal vein (n=2). In one case, a relatively long segmental thrombus occurred between the common iliac vein and the calf vein. In the occluded stent group, anatomic causes included atypical iliac vein compression (n=3) and a relatively long segmental thrombus between the common iliac and the calf vein (n=4). Typical iliac vein compression (May-Thurner syndrome) occurred in two cases, and a relatively short segmental thrombus between the external iliac and the common femoral vein in one. Factors which can affect the patency of an iliac venous stent positioned after catheter-directed thrombolysis are the anatomic cause of the stenosis, and the extent of a thrombus revealed at CT of acute DVT and occurring in a lower extremity prior to

Effect of cause of iliac vein stenosis and extent of thrombus in the lower extremity on patency of iliac venous stent placed after catheter-directed thrombolysis of acute deep venous thrombosis in the lower extremity

Energy Technology Data Exchange (ETDEWEB)

Jung, Sung Il; Choi, Young Ho; Yoon, Chang Jin; Lee, Min Woo; Chung, Jin Wook; Park, Jae Hyung [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

2003-10-01

To assess the CT findings of acute deep venous thrombosis (DVT) in a lower extremity prior to catheter-directed thrombolysis, and to evaluate their relevance to the patency of an iliac venous stent placed with the help of CT after catheter-directed thrombolysis of DVT. Fourteen patients [M:F=3:11; age, 33-68 (mean, 50.1) years] with acute symptomatic DVD of a lower extremity underwent CT before and after catheter-directed thrombolysis using an iliac venous stent. The mean duration of clinical symptoms was 5.0 (range, 1-14 days. The CT findings prior to thrombolysis were evaluated in terms of their anatomic cause and the extent of the thrombus, and in all patients, the patency of the iliac venous stent was assessed at CT performed during a follow-up period lasting 6-31 (mean, 18.9) months. All patients were assigned to the patent stent group (n=9) or the occluded stent group (n=5). In the former, the anatomic cause of patency included typical iliac vein compression (May-Thurner syndrome) (n=9), and a relatively short segmental thrombus occurring between the common iliac and the popliteal vein (n=8). Thrombi occurred in the iliac vein (n=3), between the common iliac and the femoral vein (n=3), and between the common iliac and the popliteal vein (n=2). In one case, a relatively long segmental thrombus occurred between the common iliac vein and the calf vein. In the occluded stent group, anatomic causes included atypical iliac vein compression (n=3) and a relatively long segmental thrombus between the common iliac and the calf vein (n=4). Typical iliac vein compression (May-Thurner syndrome) occurred in two cases, and a relatively short segmental thrombus between the external iliac and the common femoral vein in one. Factors which can affect the patency of an iliac venous stent positioned after catheter-directed thrombolysis are the anatomic cause of the stenosis, and the extent of a thrombus revealed at CT of acute DVT and occurring in a lower extremity prior to

Carbon nanotubes functionalized with fibroblast growth factor accelerate proliferation of bone marrow-derived stromal cells and bone formation

International Nuclear Information System (INIS)

Hirata, Eri; Takita, Hiroko; Watari, Fumio; Yokoyama, Atsuro; Ménard-Moyon, Cécilia; Venturelli, Enrica; Bianco, Alberto

2013-01-01

Multi-walled carbon nanotubes (MWCNTs) were functionalized with fibroblast growth factor (FGF) and the advantages of their use as scaffolds for bone augmentation were evaluated in vitro and in vivo. The activity of FGF was assessed by measuring the effect on the proliferation of rat bone marrow stromal cells (RBMSCs). The presence of FGF enhanced the proliferation of RBMSCs and the FGF covalently conjugated to the nanotubes (FGF–CNT) showed the same effect as FGF alone. In addition, FGF–CNT coated sponges were implanted between the parietal bone and the periosteum of rats and the formation of new bone was investigated. At day 14 after implantation, a larger amount of newly formed bone was clearly observed in most pores of FGF–CNT coated sponges. These findings indicated that MWCNTs accelerated new bone formation in response to FGF, as well as the integration of particles into new bone during its formation. Scaffolds coated with FGF–CNT could be considered as promising novel substituting materials for bone regeneration in future tissue engineering applications. (paper)

Carbon nanotubes functionalized with fibroblast growth factor accelerate proliferation of bone marrow-derived stromal cells and bone formation

Science.gov (United States)

Hirata, Eri; Ménard-Moyon, Cécilia; Venturelli, Enrica; Takita, Hiroko; Watari, Fumio; Bianco, Alberto; Yokoyama, Atsuro

2013-11-01

Multi-walled carbon nanotubes (MWCNTs) were functionalized with fibroblast growth factor (FGF) and the advantages of their use as scaffolds for bone augmentation were evaluated in vitro and in vivo. The activity of FGF was assessed by measuring the effect on the proliferation of rat bone marrow stromal cells (RBMSCs). The presence of FGF enhanced the proliferation of RBMSCs and the FGF covalently conjugated to the nanotubes (FGF-CNT) showed the same effect as FGF alone. In addition, FGF-CNT coated sponges were implanted between the parietal bone and the periosteum of rats and the formation of new bone was investigated. At day 14 after implantation, a larger amount of newly formed bone was clearly observed in most pores of FGF-CNT coated sponges. These findings indicated that MWCNTs accelerated new bone formation in response to FGF, as well as the integration of particles into new bone during its formation. Scaffolds coated with FGF-CNT could be considered as promising novel substituting materials for bone regeneration in future tissue engineering applications.

Managing iliofemoral deep venous thrombosis of pregnancy with a strategy of thrombus removal is safe and avoids post-thrombotic morbidity.

Science.gov (United States)

Herrera, Santiago; Comerota, Anthony J; Thakur, Subhash; Sunderji, Shiraz; DiSalle, Robert; Kazanjian, Sahira N; Assi, Zakaria

2014-02-01

Extensive deep venous thrombosis (DVT) during pregnancy is usually treated with anticoagulation alone, risking significant post-thrombotic syndrome (PTS) in young patients. Catheter-directed thrombolysis (CDT) and operative venous thrombectomy have been safely and effectively used in nonpregnant patients, demonstrating significant reduction in post-thrombotic morbidity. This report reviews short- and long-term outcomes of 13 patients with extensive DVT of pregnancy treated with a strategy of thrombus removal. From 1999 to 2013, 13 patients with iliofemoral DVT during pregnancy were offered CDT, pharmacomechanical thrombolysis (PMT), and/or venous thrombectomy. Gestational age ranged from 8 to 34 weeks. Fetal monitoring was performed throughout hospitalization. Radiation exposure was minimized with pelvic lead shields, focal fluoroscopy, and limited angiographic runs. Follow-up included objective vein evaluation using venous duplex and PTS assessment using the Villalta scale. CDT and/or PMT were used in 11 patients. Two patients underwent venous thrombectomy alone, and one patient had operative thrombectomy as an adjunct to CDT and PMT. Each patient had complete or near-complete thrombus resolution and rapid improvement in clinical symptoms. Eight of 11 having CDT or PMT underwent venoplasty and stenting of the involved iliac veins. Twelve of the 13 delivered healthy infants at term. One patient opted for termination of her pregnancy. Mean patient and gestational ages were 26 years and 26 weeks, respectively. Mean follow-up was 1.3 years, with only one recurrence. Duplex ultrasonography demonstrated patent veins in all but one patient and normal valve function in 10 patients. Eleven patients had Villalta scores thrombus removal, resulting in a patent venous system, normal valve function in many, prevention of PTS, and reduction in recurrence. Copyright © 2014. Published by Mosby, Inc.

Combined MR direct thrombus imaging and non-contrast magnetic resonance venography reveal the evolution of deep vein thrombosis: a feasibility study.

Science.gov (United States)

Mendichovszky, I A; Priest, A N; Bowden, D J; Hunter, S; Joubert, I; Hilborne, S; Graves, M J; Baglin, T; Lomas, D J

2017-06-01

Lower limb deep venous thrombosis (DVT) is a common condition with high morbidity and mortality. The aim of the study was to investigate the temporal evolution of the acute thrombus by magnetic resonance imaging (MRI) and its relationship to venous recanalization in patients with recurrent DVTs. Thirteen patients with newly diagnosed lower limb DVTs underwent MRI with non-contrast MR venography (NC-MRV) and MR direct thrombus imaging (MR-DTI), an inversion-recovery water-selective fast gradient-echo acquisition. Imaging was performed within 7 days of the acute thrombotic event, then at 3 and 6 months. By 3 months from the thrombotic event a third of the thrombi had resolved and by 6 months about half of the cases had resolved on the basis of vein recanalisation using NC-MRV. On the initial MR-DTI acute thrombus was clearly depicted by hyperintense signal, while the remaining thrombi were predominantly low signal at 3 and 6 months. Some residual thrombi contained small and fragmented persisting hyperintense areas at 3 months, clearing almost completely by 6 months. Our study suggests that synergistic venous assessment with combined NC-MRV and MR-DTI is able to distinguish acute venous thrombosis from the established (old) or evolving DVT detected by ultrasound. • MRI can distinguish between acute and evolving or chronic lower limb DVT • Two advanced MRI techniques can follow the evolution of lower limb DVT • MRI could be used to avoid an incorrect diagnosis of recurrent DVT • MRI could help avoid the risks and complications of lifelong anticoagulation therapy.

Macroscopic ion acceleration associated with the formation of the ring current in the earth's magnetosphere

International Nuclear Information System (INIS)

Mauk, B.H.; Meng, C.I.

1986-01-01

As an illustration of the operation of macroscopic ion acceleration processes within the earth's magnetosphere, the paper reviews processes thought to be associated with the formation of the earth's ring-current populations. Arguing that the process of global, quasi-curl-free convection cannot explain particle characteristics observed in the middle (geosynchronous) to outer regions, it is concluded that the transport and energization of the seed populations that give rise to the ring-current populations come about in two distinct stages involving distinct processes. Near and outside the geostationary region, the energization and transport are always associated with highly impulsive and relatively localized processes driven by inductive electric fields. The subsequent adiabatic earthward transport is driven principally by enhanced, curl-free global convection fields. 58 references

Intervention radiology for venous thrombosis: early thrombus removal using invasive methods.

Science.gov (United States)

Casanegra, Ana I; McBane, Robert D; Bjarnason, Haraldur

2017-04-01

The post thrombotic syndrome is one of the most dreaded complications of proximal deep vein thrombosis. This syndrome leads to pain and suffering with leg swelling, recalcitrant ulceration and venous claudication which greatly impairs mobility and quality of life. The prevalence can be high in patients with iliofemoral venous involvement particularly in the setting of a proximal venous stenosis, such as occurs in May Thurner syndrome. Anticoagulation alone does not reduce the likelihood of this outcome. Compression therapy may be effective but garment discomfort limits its implementation. Pharmacomechanical thrombectomy, which combines catheter-directed thrombolysis with mechanical thrombus dissolution, provides an attractive treatment strategy for such patients. The rationale and delivery of pharmacomechanical thrombectomy, including patient selection and adjunctive antithrombotic therapy, will be reviewed in addition to tips and tricks for managing difficult patient scenarios. © 2017 John Wiley & Sons Ltd.

Defective thrombus formation in mice lacking endogenous factor VII activating protease (FSAP).

Science.gov (United States)

Subramaniam, Saravanan; Thielmann, Ina; Morowski, Martina; Pragst, Ingo; Sandset, Per Morten; Nieswandt, Bernhard; Etscheid, Michael; Kanse, Sandip M

2015-04-01

Factor VII (FVII) activating protease (FSAP) is a circulating protease with a putative function in blood coagulation and fibrinolysis. Genetic epidemiological studies have implied a role for FSAP in carotid stenosis, stroke and thrombosis. To date, no in vivo evidence is available to support these claims. We have, for the first time, used FSAP-/- mice to define its role in thrombosis and haemostasis in vivo and to characterise the molecular mechanisms involved. FeCl3-induced arterial thrombosis in carotid and mesenteric artery revealed that the occlusion time was significantly increased in FSAP-/- mice (pendogenous FSAP impaired the formation of stable, occlusive thrombi in mice. The underlying in vivo effect of FSAP is more likely to be related to the modulation of TFPI rather than FVIIa.

Accelerated formation of hydrogen-producing granules for the start-up of UASB reactors using vinasses

Directory of Open Access Journals (Sweden)

César González-Ugalde

2014-02-01

Full Text Available Hydrogen-producing granules formation was studied in a CSTR. The aim of this process is to later transfer the mixed liquor to a UASB reactor to reduce its start-up period. Vinasses from a national bioetha­nol-producing industry (from sugar cane were used as substrate and their anaerobic fermentation was carried out under mesophilic conditions. The seed sludge was collected from an UASB reactor oper­ated in an industrial wastewater treatment plant and it was heat treated to inactivate methanogenic bacteria. Total viable and non-viable material growth curves were generated and it was determined that the exponential growth phase of the thermally pre­treated mixed culture was between 20 and 120 h. Finally, the anaerobic fermentation of the vinasses in batch mode for 70 hours, and then in continuous CSTR mode for 7 days, showed to be an effective method for accelerating the formation of hydrogen-producing granules. Using this method, granules with an average size of 1.24 mm were achieved. The good efficiency of the process is attributed to high mass transfer in the CSTR reactor.

Detection of left atrial thrombus in patients with mitral stenosis and atrial fibrillation: retrospective comparison of two-phase computed tomography, transoesophageal echocardiography and surgical findings

Energy Technology Data Exchange (ETDEWEB)

Choi, Bo Hwa; Ko, Sung Min [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Radiology, Research Institute of Medical Science, Seoul (Korea, Republic of); Hwang, Hweung Kon [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Cardiology, Seoul (Korea, Republic of); Song, Meong Gun; Shin, Je Kyoun [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Thoracic surgery, Seoul (Korea, Republic of); Kang, Woon Seok; Kim, Tae-Yop [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Anesthesiology, Seoul (Korea, Republic of)

2013-11-15

This retrospective study aims to assess the accuracy of two-phase computed tomography (CT) and transoesophageal echocardiography (TEE) for the detection of left atrial (LA) thrombus in patients with mitral stenosis (MS) and atrial fibrillation (AF), by using intraoperative findings as the reference standard. Preoperative two-phase CT and intraoperative TEE were performed in 106 patients with MS and AF. The ratio (LAA/AA{sub L}) of Hounsfield units (HU) in the LA appendage (LAA) to the ascending aorta (AA) was calculated on the late-phase CT image. LA echodense masses on TEE and LA filling defects on two-phase CT were observed in 29 and 39 patients, respectively. Thirty-five LA thrombi were identified at surgery in 27 patients. Compared with the intraoperative findings, per-patient sensitivity, specificity, positive and negative predictive values of two-phase CT were 100 %, 85 %, 69 % and 100 %, and those by using TEE were 93 %, 95 %, 86 % and 97 % in detecting LAA thrombus. After adopting the cut-off value of 0.5 for the LAA/AA{sub L} HU ratio, the specificity and positive predictive value of two-phase CT were increased to 96 % and 90 %, respectively. Two-phase CT with a cut-off value of LAA/AA{sub L} HU ratio of 0.5 provides high performance for the detection of LAA thrombus. (orig.)

Huge Left Ventricular Thrombus and Apical Ballooning associated with Recurrent Massive Strokes in a Septic Shock Patient

Directory of Open Access Journals (Sweden)

Hyun-Jung Lee

2016-02-01

Full Text Available The most feared complication of left ventricular thrombus (LVT is the occurrence of systemic thromboembolic events, especially in the brain. Herein, we report a patient with severe sepsis who suffered recurrent devastating embolic stroke. Transthoracic echocardiography revealed apical ballooning of the left ventricle with a huge LVT, which had not been observed in chest computed tomography before the stroke. This case emphasizes the importance of serial cardiac evaluation in patients with stroke and severe medical illness.

Diagnosing upper extremity deep vein thrombosis with non-contrast-enhanced Magnetic Resonance Direct Thrombus Imaging: A pilot study.

Science.gov (United States)

Dronkers, C E A; Klok, F A; van Haren, G R; Gleditsch, J; Westerlund, E; Huisman, M V; Kroft, L J M

2018-03-01

Diagnosing upper extremity deep vein thrombosis (UEDVT) can be challenging. Compression ultrasonography is often inconclusive because of overlying anatomic structures that hamper compressing veins. Contrast venography is invasive and has a risk of contrast allergy. Magnetic Resonance Direct Thrombus Imaging (MRDTI) and Three Dimensional Turbo Spin-echo Spectral Attenuated Inversion Recovery (3D TSE-SPAIR) are both non-contrast-enhanced Magnetic Resonance Imaging (MRI) sequences that can visualize a thrombus directly by the visualization of methemoglobin, which is formed in a fresh blood clot. MRDTI has been proven to be accurate in diagnosing deep venous thrombosis (DVT) of the leg. The primary aim of this pilot study was to test the feasibility of diagnosing UEDVT with these MRI techniques. MRDTI and 3D TSE-SPAIR were performed in 3 pilot patients who were already diagnosed with UEDVT by ultrasonography or contrast venography. In all patients, UEDVT diagnosis could be confirmed by MRDTI and 3D TSE-SPAIR in all vein segments. In conclusion, this study showed that non-contrast MRDTI and 3D TSE-SPAIR sequences may be feasible tests to diagnose UEDVT. However diagnostic accuracy and management studies have to be performed before these techniques can be routinely used in clinical practice. Copyright © 2018 Elsevier Ltd. All rights reserved.

Potential application of labeled antibodies for thrombus detection

Energy Technology Data Exchange (ETDEWEB)

Ezekowitz, M.D.; Coller, B.S.; Srivastava, S.C.

1986-01-01

Labeling platelets with monoclonal antibodies in whole blood for imaging thrombi is less cumbersome than the established /sup 111/In-oxine method. 7E3, a murine monoclonal antibody directed against glycoprotein IIb and/or IIIa on both human and dog platelets was used to label canine platelets. Thrombi were induced by transcatheter placement of a copper coil followed by electrocoagulation. 7E3 was iodinated with /sup 131/I and labelled with /sup 111/In using 7E3-DTPA conjugate. Whole blood was incubated with 0.5 - 1.0 ..mu..g labeled 7E3/mL blood. In 4/4 dogs, experimental deep vein thrombi were identified using both /sup 131/I-and /sup 111/In-labeled 7E3 within 5-30 min after injection. For both isotopes, 1 h blood clearance was 54 + - 9%. In 1/3 dogs, experimental coronary thrombus could be identified ex vivo at 4 h. Clot to blood ratios ranged between 7 to 13:1. Using the /sup 111/In-oxine method, 0/3 coronary thrombi were seen. Thus, /sup 131/I-and /sup 111/In-labeled 7E3 may be used to readily identify peripheral venous thrombi. For reliable and prompt identification of coronary thrombi, more rapid clearance of the labeled platelets is required.

Complete Resolution of a Large Bicuspid Aortic Valve Thrombus with Anticoagulation in Primary Antiphospholipid Syndrome

Directory of Open Access Journals (Sweden)

Rayan Jo Rachwan

2017-09-01

Full Text Available Native aortic valve thrombosis in primary antiphospholipid syndrome (APLS is a rare entity. We describe a 38-year-old man who presented with neurological symptoms and a cardiac murmur. Transthoracic echocardiography detected a large bicuspid aortic valve thrombus. Laboratory evaluation showed the presence of antiphospholipid antibodies. Anticoagulation was started, and serial echocardiographic studies showed complete resolution of the aortic valve vegetation after 4 months. The patient improved clinically and had no residual symptoms. This report and review of the literature suggests that vegetations in APLS can be treated successfully with conservative treatment, regardless of their size.

Thrombus aspiration combined with intra-coronary injection of Tirofiban for acute ST-segment elevation myocardial infarction: its influence on myocardial reperfusion

International Nuclear Information System (INIS)

Yin Da; Zhu Hao; Zhou Xuchen; Huang Rongchong; Zhang Bo; Wang Shaopeng; Zhang Yousheng; Jia Yuqing; Sun Menghan; Cui Hashen

2011-01-01

Objective: To explore the influence of thrombus aspiration combined with intra-coronary administration of the glycoprotein Ⅱ b/Ⅲ a inhibitor, Tirofiban, on myocardial microcirculation when percutaneous coronary intervention (PCI) is employed for the treatment of acute ST-segment elevation myocardial infarction. Methods: During the period from April 2008 to June 2010, percutaneous coronary interventional was performed in 184 consecutive patients with acute ST-segment elevation myocardial infarction. The patients were randomly divided into study group (n=78) and control group (n=106). Thrombus aspiration combined with intra-coronary administration of Tirofiban was used in patients of study group, while routine PCI together with intravenous administration of Tirofiban was adopted in patients of control group. Clinical features, TIMI grade, myocardial blush grade, ratio of ST falling >70% at 24 hours after treatment, incidence of massive haemorrhage, hospitalization, days, major adverse cardiac event within 30 days were observed, and the results were compared between two groups. Results: The incidence of no reflow phenomenon in study group was markedly lower than that in control group (5.67% vs. 21.14%, P=0.011), while the myocardial blush grade was much higher in study group than that in control group (2.03±0.32 vs. 1.12±0.47, P=0.021). The ratio of ST falling > 70% at 24 hours after treatment in study group was increased (94% vs. 85%, P=0.003), and the occurrence of perioperative massive haemorrhage was lower (9% vs. 4%, P=0.03). The incidence of major adverse cardiac event within 30 days was distinctly decreased although it was quite similar in both groups (5.5% vs. 6.1%, P=0.786). Conclusion: Thrombus aspiration combined with intra-coronary administration of Tirofiban is superior to conventional PCI in effectively improving the reperfusion of myocardial microcirculation and in reliably reducing perioperative risk. (authors)

PATHOPHYSIOLOGY STROKE NON-HEMORRHAGIC ET CAUSA THROMBUS

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Aji Kristianto Wijaya

2013-10-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Stroke is one of the most common cause of death worldwide and the third leading cause of death in the United States. Stroke composed 90,000 deaths of women and 60,000 men each year. In Indonesia, 8 of 1000 people suffered a stroke. Stroke is divided into two, non-hemorrhagic stroke and hemorrhagic stroke. Most of them (80% is non-hemorrhagic stroke. Non-hemorrhagic stroke can be caused by thrombi or emboli. Understanding the pathophysiology of non-hemorrhagic stroke caused by a thrombus is very important in regard with providing appropriate patient management. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Late Thrombolytic Treatment In A Patient With Ischemic Stroke Caused By Biatrial Thrombus

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Halit CINARKA

2015-07-01

Full Text Available Venous thromboembolism is a preventable disease when necessary precautions are taken and it occurs along with deep vein thrombosis and pulmonary embolism. Mortality related to venous thromboembolism may be high in the acute phase of the disease and it may become chronic. Intracardiac thrombus may be detected in some venous thromboemboli cases. Cardiac embolism is responsible for most of the ischemic strokes which can be very mortal or may cause serious morbidity when they are not treated in time. In this report, we aimed to present the results of late antithrombolytic treatment in a 77-year old patient who developed deep vein thrombosis, biatrial thrombosis and ischemic stroke following hydrocephalus shunt operation.   Key words: Venous thromboembolism; ischemic stroke; thrombolytic therapy

Inhibition of plasminogen activator inhibitor-1 activity results in promotion of endogenous thrombolysis and inhibition of thrombus extension in models of experimental thrombosis

NARCIS (Netherlands)

Levi, M. [=Marcel M.; Biemond, B. J.; van Zonneveld, A. J.; ten Cate, J. W.; Pannekoek, H.

1992-01-01

We investigated the effect of inhibition of plasminogen activator inhibitor-1 (PAI-1) activity by a murine monoclonal anti-human PAI-1 antibody (MAI-12) on in vitro thrombolysis and on in vivo thrombolysis and thrombus extension in an experimental animal model for thrombosis. Thrombolysis, mediated

Rivaroxaban attenuates thrombosis by targeting the NF-κB signaling pathway in a rat model of deep venous thrombus

OpenAIRE

Ma, Junhao; Li, Xinxi; Wang, Yang; Yang, Zhenwei; Luo, Jun

2017-01-01

Anticoagulant therapy is commonly used for the prevention and treatment of patients with deep venous thrombus. Evidence has shown that rivaroxaban is a potential oral anticoagulant drug for the acute treatment of venous thromboembolism. However, the rivaroxaban-mediated molecular mechanism involved in the progression of deep venous thrombosis has not been investigated. In the present study, we investigated the efficacy of rivaroxaban and the underlying signaling pathways in the prevention and...

Platelet thrombosis in cardiac-valve prostheses

International Nuclear Information System (INIS)

Dewanjee, M.K.

1989-01-01

The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs

Platelet thrombosis in cardiac-valve prostheses

Energy Technology Data Exchange (ETDEWEB)

Dewanjee, M.K.

1989-01-01

The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs.

Ultra-High Intensity Proton Accelerators and their Applications

International Nuclear Information System (INIS)

Weng, W. T.

1997-01-01

The science and technology of proton accelerators have progressed considerably in the past three decades. Three to four orders of magnitude increase in both peak intensity and average flux have made it possible to construct high intensity proton accelerators for modern applications, such as: spallation neutron sources, kaon factory, accelerator production of tritium, energy amplifier and muon collider drivers. The accelerator design focus switched over from intensity for synchrotrons, to brightness for colliders to halos for spallation sources. An overview of this tremendous progress in both accelerator science and technology is presented, with special emphasis on the new challenges of accelerator physics issues such as: H(-) injection, halo formation and reduction of losses

An investigation on platelet transport during thrombus formation at micro-scale stenosis.

Directory of Open Access Journals (Sweden)

Francisco Javier Tovar-Lopez

Full Text Available This paper reports on an investigation of mass transport of blood cells at micro-scale stenosis where local strain-rate micro-gradients trigger platelet aggregation. Using a microfluidic flow focusing platform we investigate the blood flow streams that principally contribute to platelet aggregation under shear micro-gradient conditions. We demonstrate that relatively thin surface streams located at the channel wall are the primary contributor of platelets to the developing aggregate under shear gradient conditions. Furthermore we delineate a role for red blood cell hydrodynamic lift forces in driving enhanced advection of platelets to the stenosis wall and surface of developing aggregates. We show that this novel microfluidic platform can be effectively used to study the role of mass transport phenomena driving platelet recruitment and aggregate formation and believe that this approach will lead to a greater understanding of the mechanisms underlying shear-gradient dependent discoid platelet aggregation in the context of cardiovascular diseases such as acute coronary syndromes and ischemic stroke.

Production, Characterization, and Acceleration of Optical Microbunches

Energy Technology Data Exchange (ETDEWEB)

Sears, Christopher M.S. [Stanford Univ., CA (United States)

2008-06-20

Optical microbunches with a spacing of 800 nm have been produced for laser acceleration research. The microbunches are produced using a inverse Free-Electron-Laser (IFEL) followed by a dispersive chicane. The microbunched electron beam is characterized by coherent optical transition radiation (COTR) with good agreement to the analytic theory for bunch formation. In a second experiment the bunches are accelerated in a second stage to achieve for the first time direct net acceleration of electrons traveling in a vacuum with visible light. This dissertation presents the theory of microbunch formation and characterization of the microbunches. It also presents the design of the experimental hardware from magnetostatic and particle tracking simulations, to fabrication and measurement of the undulator and chicane magnets. Finally, the dissertation discusses three experiments aimed at demonstrating the IFEL interaction, microbunch production, and the net acceleration of the microbunched beam. At the close of the dissertation, a separate but related research effort on the tight focusing of electrons for coupling into optical scale, Photonic Bandgap, structures is presented. This includes the design and fabrication of a strong focusing permanent magnet quadrupole triplet and an outline of an initial experiment using the triplet to observe wakefields generated by an electron beam passing through an optical scale accelerator.

Endovascular treatment of intrahepatic inferior vena cava obstruction from malignant hepatocellular tumor thrombus utilizing Luminexx self-expanding nitinol stents

International Nuclear Information System (INIS)

Stambo, Glenn W.; Leto, John; George, Christopher; Van Epps, Kelly; Woeste, Troy; Berlet, Mathew

2008-01-01

Inferior vena cava (IVC) obstruction is a well-described clinical entity. Most IVC obstructions from malignant neoplasms are a direct result of tumor compression [Oviedo J, Cerda S. Vascular invasion by hepatocellular carcinoma. Arch Pathol Lab Med 2001;125: 454-5; Furui S, Sawada S, et al. Gianturco stent placement in malignant caval obstruction: analysis of factors for predicting the outcome. Radiology 1995;195:147-52; Fletcher WS, Lakin PC, et al. Results of treatment of inferior vena cava syndrome with expandable metallic stents. Arch Surg 1998;133:935-8]. The symptoms of IVC obstruction include progressive ascites, scrotal edema and lower body edema. These constellations of symptoms are described as IVC syndrome and are devastating to a patient with end-stage cancer. We describe a palliative therapy utilizing Luminexx nitinol self-expanding stents to treat intracaval hepatoma thrombus obstructing the IVC. The procedure is rapidly performed, technically reliable, and has essentially no morbidity or mortality. This procedure can be performed in the interventional radiology suite with excellent results resolving the IVC syndrome soon after placement of the stents. We believe endovascular stenting as an excellent palliative therapy for patients with IVC syndrome and should be the treatment of choice for caval obstructions due to intraluminal tumor thrombus

Endovascular treatment of intrahepatic inferior vena cava obstruction from malignant hepatocellular tumor thrombus utilizing Luminexx self-expanding nitinol stents

Energy Technology Data Exchange (ETDEWEB)

Stambo, Glenn W. [Division of Vascular and Interventional Radiology, Department of Radiology, St. Joseph' s Hospital and Medical Center, 4516 North Armenia Avenue, Tampa, FL 33603 (United States)], E-mail: xraydoc2@yahoo.com; Leto, John [Division of Vascular and Interventional Radiology, Department of Radiology, St. Joseph' s Hospital and Medical Center, 3001 W. Dr. Martin Luther King Jr. Blvd., Tampa, FL 33607 (United States); George, Christopher [Department of Hematology and Oncology, St. Joseph' s Hospital and Medical Center, 4301 W. Habana Avenue, Suite 1, Tampa, FL 33607 (United States); Van Epps, Kelly; Woeste, Troy; Berlet, Mathew [Division of Vascular and Interventional Radiology, Department of Radiology, St. Joseph' s Hospital and Medical Center, 4516 North Armenia Avenue, Tampa, FL 33603 (United States)

2008-05-15

Inferior vena cava (IVC) obstruction is a well-described clinical entity. Most IVC obstructions from malignant neoplasms are a direct result of tumor compression [Oviedo J, Cerda S. Vascular invasion by hepatocellular carcinoma. Arch Pathol Lab Med 2001;125: 454-5; Furui S, Sawada S, et al. Gianturco stent placement in malignant caval obstruction: analysis of factors for predicting the outcome. Radiology 1995;195:147-52; Fletcher WS, Lakin PC, et al. Results of treatment of inferior vena cava syndrome with expandable metallic stents. Arch Surg 1998;133:935-8]. The symptoms of IVC obstruction include progressive ascites, scrotal edema and lower body edema. These constellations of symptoms are described as IVC syndrome and are devastating to a patient with end-stage cancer. We describe a palliative therapy utilizing Luminexx nitinol self-expanding stents to treat intracaval hepatoma thrombus obstructing the IVC. The procedure is rapidly performed, technically reliable, and has essentially no morbidity or mortality. This procedure can be performed in the interventional radiology suite with excellent results resolving the IVC syndrome soon after placement of the stents. We believe endovascular stenting as an excellent palliative therapy for patients with IVC syndrome and should be the treatment of choice for caval obstructions due to intraluminal tumor thrombus.

Use of multidetector-row computed tomography scan to detect pannus formation in prosthetic mechanical aortic valves.

Science.gov (United States)

Aladmawi, Mohamed A; Pragliola, Claudio; Vriz, Olga; Galzerano, Domenico

2017-04-01

Obstruction of a mechanical aortic valve by pannus formation at the subvalvular level is a major long-term complication of aortic valve replacement (AVR). In fact, pannus is sometime difficult to differentiate from patient-prosthesis mismatch or valve thrombosis. In most cases cine-angiography and echocardiography, either transthoracic or transesophageal, cannot correctly visualize the complication when the leaflets show a normal mobility. Recent technological refinements made this difficult diagnosis possible by ECG-gated computed tomography (CT) scan which shows adequate images in 90% of the cases and can differentiate pannus from fresh and organized thrombus.

The Los Alamos Laser Acceleration of Particles Workshop and beginning of the advanced accelerator concepts field

Science.gov (United States)

Joshi, C.

2012-12-01

The first Advanced Acceleration of Particles-AAC-Workshop (actually named Laser Acceleration of Particles Workshop) was held at Los Alamos in January 1982. The workshop lasted a week and divided all the acceleration techniques into four categories: near field, far field, media, and vacuum. Basic theorems of particle acceleration were postulated (later proven) and specific experiments based on the four categories were formulated. This landmark workshop led to the formation of the advanced accelerator R&D program in the HEP office of the DOE that supports advanced accelerator research to this day. Two major new user facilities at Argonne and Brookhaven and several more directed experimental efforts were built to explore the advanced particle acceleration schemes. It is not an exaggeration to say that the intellectual breadth and excitement provided by the many groups who entered this new field provided the needed vitality to then recently formed APS Division of Beams and the new online journal Physical Review Special Topics-Accelerators and Beams. On this 30th anniversary of the AAC Workshops, it is worthwhile to look back at the legacy of the first Workshop at Los Alamos and the fine groundwork it laid for the field of advanced accelerator concepts that continues to flourish to this day.

Accelerated and Decelerated Flows in a Circular Pipe : 1st Report, Velocity Profile and Friction Coefficient

OpenAIRE

Kurokawa, Junichi; Morikawa, Masahiro

1986-01-01

In order to determine the flow characteristics of a transient flow in a circular pipe, an accelerated and a decelerated flow are studied, and effects of acceleration upon the formation of a velocity profile, transition and a friction coefficient are determined for a wide range of accelerations. The results of the accelerated flow show that there are two patterns in the formation of a sectional velocity profile and transition, one of which is observed when the acceleration is relatively large ...

Increase in the Acceleration Efficiency of Solids in a Hybrid Coaxial Magnetoplasma Accelerator

Science.gov (United States)

Gerasimov, D. Yu.; Sivkov, A. A.

2018-01-01

It is shown that in a hybrid coaxial magnetoplasma accelerator with a channel length of 350 mm and a diameter of 23 mm, the acceleration velocity and the energy conversion efficiency increase as the length of the plasma structure formation channel filled with a gas-generating material decreases from 17 to 9 mm. It is found that it is reasonable to use paraffin as the gas-generating material as it has a less significant deionizing effect on the high-current arc discharge and hence causes a less significant decrease in the discharge current intensity and an increase in conductive and inductive electrodynamic forces.

Collective ion acceleration by means of virtual cathodes

International Nuclear Information System (INIS)

Peter, W.; Faehl, R.J.; Snell, C.; Jones, M.E.

1985-01-01

Experiments on collective ion acceleration by means of the formation of a virtual cathode have been carried out for a number of years in the Soviet Union and in the United States. Recently, there has been renewed interest in the subject as a possible means of accelerating ions to very high energies. By understanding the physics underlying the acceleration process it may be possible to determine the feasibility of virtual cathode staging for very high energy ion production. For this reason, a theoretical and computational effort is underway at Los Alamos in order to clarify the basic issues of collective ion acceleration by means of virtual cathodes. To support the theoretical effort, simulations were done with the fully electromagnetic and relativistic particle-in-cell code ISIS (in a one-dimensional mode) and the electrostatic one-dimensional code BIGONE. In the simulations, an electron beam of density 6 x 10 11 cm -3 is injected into a one-dimensional box of length L. To supply the necessary ions for collective acceleration, a plasma source containing both ions and electrons was initialized near the emitting boundary. Of prime interest in this study was to understand the dynamics of virtual cathode formation and the dynamics of the acceleration process for the ions. In particular, the question of whether the ions are accelerated by a moving potential well or hydrodynamic pressure due to ambipolar expansion is of primary interest. 3 refs., 5 figs

Modeling of thermalization phenomena in coaxial plasma accelerators

Science.gov (United States)

Subramaniam, Vivek; Panneerchelvam, Premkumar; Raja, Laxminarayan L.

2018-05-01

Coaxial plasma accelerators are electromagnetic acceleration devices that employ a self-induced Lorentz force to produce collimated plasma jets with velocities ~50 km s‑1. The accelerator operation is characterized by the formation of an ionization/thermalization zone near gas inlet of the device that continually processes the incoming neutral gas into a highly ionized thermal plasma. In this paper, we present a 1D non-equilibrium plasma model to resolve the plasma formation and the electron-heavy species thermalization phenomena that take place in the thermalization zone. The non-equilibrium model is based on a self-consistent multi-species continuum description of the plasma with finite-rate chemistry. The thermalization zone is modelled by tracking a 1D gas-bit as it convects down the device with an initial gas pressure of 1 atm. The thermalization process occurs in two stages. The first is a plasma production stage, associated with a rapid increase in the charged species number densities facilitated by cathode surface electron emission and volumetric production processes. The production stage results in the formation of a two-temperature plasma with electron energies of ~2.5 eV in a low temperature background gas of ~300 K. The second, a temperature equilibration stage, is characterized by the energy transfer between the electrons and heavy species. The characteristic length scale for thermalization is found to be comparable to axial length of the accelerator thus putting into question the equilibrium magnetohydrodynamics assumption used in modeling coaxial accelerators.

New Pulsed Power Technology for High Current Accelerators

International Nuclear Information System (INIS)

Caporaso, G J

2002-01-01

Recent advances in solid-state modulators now permit the design of a new class of high current accelerators. These new accelerators will be able to operate in burst mode at frequencies of several MHz with unprecedented flexibility and precision in pulse format. These new modulators can drive accelerators to high average powers that far exceed those of any other technology and can be used to enable precision beam manipulations. New insulator technology combined with novel pulse forming lines and switching may enable the construction of a new type of high gradient, high current accelerator. Recent developments in these areas will be reviewed

Accelerated effects of nano-ZnO on phosphorus removal by Chlorella vulgaris: Formation of zinc phosphate crystallites.

Science.gov (United States)

Xiao, Huaixian; Liu, Na; Tian, Ke; Liu, Shixiang; Ge, Fei

2018-09-01

Nanoparticles have been reported to induce toxicity to aquatic organisms, however, their potential impacts on phosphorus removal from wastewater by algae are unclear. In this study, the effects of nanoparticle ZnO (nano-ZnO) on phosphate (PO 4 3- ) removal by a green alga Chlorella vulgaris were investigated. We found that PO 4 3- removal efficiency was accelerated with high concentrations of nano-ZnO (0.04-0.15mM) but reduced with low concentrations of nano-ZnO (0.005-0.04mM) compared to the control (without nano-ZnO), suggesting that PO 4 3- removal efficiency by C. vulgaris was related to nano-ZnO concentrations. Moreover, we observed changes of nano-ZnO morphology and detected element P on the surface of nano-ZnO by using transmission electronic microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDX), indicating that PO 4 3- was interacted with nano-ZnO or the dissolved Zn 2+ from nano-ZnO. Furthermore, we confirmed this interaction induced the formation of Zn 3 (PO 4 ) 2 crystallites sedimentation by employing X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS), which finally accelerates the removal of PO 4 3- . Copyright © 2018 Elsevier B.V. All rights reserved.

Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator

International Nuclear Information System (INIS)

Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

2013-01-01

The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA

Black-blood thrombus imaging (BTI): a contrast-free cardiovascular magnetic resonance approach for the diagnosis of non-acute deep vein thrombosis.

Science.gov (United States)

Xie, Guoxi; Chen, Hanwei; He, Xueping; Liang, Jianke; Deng, Wei; He, Zhuonan; Ye, Yufeng; Yang, Qi; Bi, Xiaoming; Liu, Xin; Li, Debiao; Fan, Zhaoyang

2017-01-18

Deep vein thrombosis (DVT) is a common but elusive illness that can result in long-term disability or death. Accurate detection of thrombosis and assessment of its size and distribution are critical for treatment decision-making. In the present study, we sought to develop and evaluate a cardiovascular magnetic resonance (CMR) black-blood thrombus imaging (BTI) technique, based on delay alternating with nutation for tailored excitation black-blood preparation and variable flip angle turbo-spin-echo readout, for the diagnosis of non-acute DVT. METHODS: This prospective study was approved by institutional review board and informed consent obtained from all subjects. BTI was first conducted in 11 healthy subjects for parameter optimization and then conducted in 18 non-acute DVT patients to evaluate its diagnostic performance. Two clinically used CMR techniques, contrast-enhanced CMR venography (CE-MRV) and three dimensional magnetization prepared rapid acquisition gradient echo (MPRAGE), were also conducted in all patients for comparison. All images obtained from patients were analyzed on a per-segment basis. Using the consensus diagnosis of CE-MRV as the reference, the sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV), and accuracy (ACC) of BTI and MPRAGE as well as their diagnostic agreement with CE-MRV were calculated. Besides, diagnostic confidence and interreader diagnostic agreement were evaluated for all three techniques. BTI with optimized parameters effectively nulled the venous blood flow signal and allowed directly visualizing the thrombus within the black-blood lumen. Higher SE (90.4% vs 67.6%), SP (99.0% vs. 97.4%), PPV (95.4% vs. 85.6%), NPV (97.8% vs 92.9%) and ACC (97.4% vs. 91.8%) were obtained by BTI in comparison with MPRAGE. Good diagnostic confidence and excellent diagnostic and interreader agreements were achieved by BTI, which were superior to MPRAGE on detecting the chronic thrombus. BTI allows

Ischemic Stroke: What Does the Histological Composition Tell Us About the Origin of the Thrombus?

Science.gov (United States)

Sporns, Peter B; Hanning, Uta; Schwindt, Wolfram; Velasco, Aglaé; Minnerup, Jens; Zoubi, Tarek; Heindel, Walter; Jeibmann, Astrid; Niederstadt, Thomas Ulrich

2017-08-01

The introduction of stent retrievers allows for a complete extraction and histological analysis of human thrombi. Ischemic stroke is a major health issue, and differentiation of underlying causes is highly relevant to prevent recurrent stroke. Therefore, histopathologic analysis of the embolic clots after removal may provide valuable information about underlying pathologies. This study analyzes histological clot composition and aims to identify specific patterns that might help to distinguish causes of ischemic stroke. Patients with occlusion of the carotid-T or middle cerebral artery who underwent thrombectomy at our university medical center between December 2013 and February 2016 were included. Samples were histologically analyzed (hematoxylin and eosin, Elastica van Gieson, and Prussian blue), additionally immunohistochemistry for CD3, CD20, and CD68/KiM1P was performed. These data, along with additional clinical and interventional parameters, were compared for different stroke subtypes, as defined by the TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. One hundred eighty-seven patients were included, of these, in 77 patients, cardioembolic; in 46 patients, noncardioembolic; and in 64 patients, cryptogenic pathogenesis was determined. Cardioembolic thrombi had higher proportions of fibrin/platelets ( P =0.027), less erythrocytes ( P =0.005), and more leucocytes ( P =0.026) than noncardioembolic thrombi. We observed a strong overlap of cryptogenic strokes and cardioembolic strokes concerning thrombus histology. The immunohistochemical parameters CD3, CD20, and CD68/KiM1P showed no statistically noticeable differences between stroke subtypes. Histological thrombus features vary significantly according to the underlying cause and may help to differentiate between cardioembolic and noncardioembolic stroke. In addition, our study supports the hypothesis that most cryptogenic strokes have a cardioembolic cause. © 2017 American Heart Association

Relativistic ion acceleration by ultraintense laser interactions

International Nuclear Information System (INIS)

Nakajima, K.; Koga, J.K.; Nakagawa, K.

2001-01-01

There has been a great interest in relativistic particle generation by ultraintense laser interactions with matter. We propose the use of relativistically self-focused laser pulses for the acceleration of ions. Two dimensional PIC simulations are performed, which show the formation of a large positive electrostatic field near the front of a relativistically self-focused laser pulse. Several factors contribute to the acceleration including self-focusing distance, pulse depletion, and plasma density. Ultraintense laser-plasma interactions are capable of generating enormous electrostatic fields of ∼3 TV/m for acceleration of protons with relativistic energies exceeding 1 GeV

Canola and hydrogenated soybean oils accelerate ectopic bone formation induced by implantation of bone morphogenetic protein in mice

Directory of Open Access Journals (Sweden)

Yoko Hashimoto

2014-01-01

Full Text Available Canola oil (Can and hydrogenated soybean oil (H2-Soy are commonly used edible oils. However, in contrast to soybean oil (Soy, they shorten the survival of stroke-prone spontaneously hypertensive (SHRSP rats. It has been proposed that the adverse effects of these oils on the kidney and testis are caused at least in part by dihydro-vitamin K (VK 1 in H2-Soy and unidentified component(s in Can. Increased intake of dihydro-VK1 is associated with decreased tissue VK2 levels and bone mineral density in rats and humans, respectively. The aim of the present study was to determine the effects of these oils on bone morphogenetic protein (BMP-induced ectopic bone formation, which is promoted by VK2 deficiency, in relation to the role of VK in the γ-carboxylation of osteocalcin and matrix Gla protein. A crude extract of BMPs was implanted into a gap in the fascia of the femoral muscle in 5-week-old mice maintained on a Soy, Can, or H2-Soy diet. Newly formed bone volume, assessed by three-dimensional X-ray micro-computed tomography and three-dimensional reconstruction imaging for bone, was 4-fold greater in the Can and H2-Soy groups than in the Soy group. The plasma carboxylated osteocalcin (Gla-OC and total OC (Gla-OC plus undercarboxylated osteocalcin [Glu-OC] levels were significantly lower in the Can group than in the Soy group (p < 0.05. However, these levels did not significantly differ between the H2-Soy and Soy groups. The plasma Gla-OC/Glu-OC ratio in the Can and H2-Soy groups was significantly lower (in Can; p = 0.044 or was almost significantly lower (in H2-Soy; p = 0.053 than that in the Soy group. In conclusion, Can and H2-Soy accelerated BMP-induced bone formation in mice to a greater extent than Soy. Further research is required to evaluate whether the difference in accelerated ectopic bone formation is associated with altered levels of VK2 and VK-dependent protein(s among the three dietary groups.

Long-term clinical outcomes of the left ventricular thrombus in patients with ST elevation anterior myocardial infarction

Directory of Open Access Journals (Sweden)

Mahmoud Ebrahimi

2015-01-01

Full Text Available BACKGROUND: This study was performed to determine the size of left ventricular thrombus (LVT, risk of systemic embolization and response to medical treatment during 18 months of follow up in the patients with anterior-ST elevation myocardial infarction (aSTEMI. METHODS: This cross-sectional study was performed on thirty-five patients with anterior myocardial infarction (MI, in Emam Reza Hospital and Ghaem Hospital, Mashhad, Iran, from August 2008 to January 2011. Warfarin was prescribed for all the patients. Transthoracic echocardiographic study was performed on the 1st, 2nd, 4th, 6th, 12th and 18th months. Outcomes included rate of death, MI, stroke, systemic embolization, major bleeding and change in thrombus size following treatment. RESULTS: The resolve rate of clot on the 2nd, 4th, 6th, 12th and 18th months was 64.7, 86.6, 81.4, 81.4 and 100 percent, respectively. In five patients with complete clot resolution, clot reformation occurred after warfarin discontinuation. In these patients, left ventricular ejection fraction (LVEF improvement was poor. During the study period, five patients died due to severe heart failure. One patient developed hematuria whereas non-experienced thromboembolic events. The mean LVEF at study initiation was 30.8 ± 0.92%, which improved to 42 ± 0.84% (P < 0.05 at the end. CONCLUSION: All LVT was resolved with a combination therapy of antiplatelet and warfarin without any thromboembolic event. In patients with a poor improvement in the LV function, due to the risk of LVT reformation, lifelong warfarin therapy was recommended. 

Ion sources for accelerators

International Nuclear Information System (INIS)

Alton, G.D.

1974-01-01

A limited review of low charge sate positive and negative ion sources suitable for accelerator use is given. A brief discussion is also given of the concepts underlying the formation and extraction of ion beams. Particular emphasis is placed on the technology of ion sources which use solid elemental or molecular compounds to produce vapor for the ionization process

Abdominal aortic aneurysm, arterial stiffening and the role of the intraluminal thrombus

DEFF Research Database (Denmark)

Lyck Hansen, Maria; Dahl Thomsen, Marie; Melholt Rasmussen, Lars

2015-01-01

PATIENTS AND METHODS: PWV and PWA were measured in male patients with AAA from an ongoing Danish AAA screening trial. Information on blood pressure, medications, BMI and smoking status was obtained at inclusion. RESULTS: In total, 157 patients were included. Mean age was 73 years. Mean AAA size...... was 42.2 mm. Fifty-six of the patients had an intraluminal thrombus, and patients with AAA and ILT had a significantly higher Aix75 than patients with AAA but without ILT (Mean = 28.3 ± 1.4 SEM vs. 24.9 ± 0.81, p=0.027), a difference that was also significant when adjusting for AAA size, blood pressure...... and age. There was no difference in PWV between the groups. CONCLUSIONS: Haemodynamic properties of the aorta are affected by the presence of ILT in patients with AAA that is not explained by aortic size. Alternatively, these findings could be explained by associations between ILT and properties...

The short-term prognostic value of thrombus precursor protein in patients with unstable angina

International Nuclear Information System (INIS)

Shen Yanbo; Yu Yan; Tang Jianzhong; Yuan Dingshan; Cai Danlei

2005-01-01

Objective: To investigate the short-term prognostic value of thrombus precursor protein (TpP) in patients with unstable angina (UA). Methods: One hundred and ten cases of UA were selected. The TpP was measured by enzyme linked immunosorbent assay (ELISA). The cardiovascular events were observed in 6 months. Results: In the 100 cases of UA, the cardiovascular events were observed in 17 cases. There was an significant difference in three levels of TpP (P<0.05). The risk level was increasing as the increasing of the plasma level of TpP. Conclusion: The level of TpP has certain reference value and plays a role in forecasting of the short-term prognosis of the patients with UA. When the plasma level of TpP increases there is also an increase in OR. (authors)

Impact of short-term hemodialysis catheters on the central veins: a catheter venographic study

Energy Technology Data Exchange (ETDEWEB)

Oguzkurt, Levent E-mail: loguzkurt@yahoo.com; Tercan, Fahri; Torun, Dilek; Yildirim, Tuelin; Zuemruetdal, Ayseguel; Kizilkilic, Osman

2004-12-01

Objective: To determine the incidence of pericatheter sleeve formation, thrombus formation, and stenosis of the central veins in hemodialysis patients with temporary catheters. Methods and material: In this prospective study, 57 patients (40 males, 17 females) with temporary dialysis catheters had catheter venography by pulling back the catheter just before removal. Patient's age range was 25-87 years (mean age, 51 years). The venographic studies were evaluated for pericatheter sleeve formation, thrombus formation, and stenosis of the brachiocephalic vein (BCV) and the superior vena cava (SVC). The IJV could only be evaluated if there was adequate filling during contrast administration. In a subgroup of patients who had had only right IJV or only right SCV catheters, impact of these catheters on the central veins was compared. Results: The catheter location was right internal jugular vein (IJV) in 26 cases, right subclavian vein (SCV) in 27 cases, left IJV in 1 case, and left SCV in 3 cases. Thirty-two patients (56%) had had only one temporary catheter and the rest had had more than one inserted. The mean dwell time for the catheters was 21 days (range 7-59 days). A pericatheter sleeve was detected on venography in 32 (56%) patients and thrombus formation was noted in 16 patients (28%). A total of 41 patients (72%) exhibited pericatheter sleeve and/or thrombus formation. While 19 of the 32 patients (59%) without previous catheterization had a sleeve around the catheter, only 13 (52%) of 25 patients who had had multiple catheters inserted had a sleeve (P>0.05). Of the eight patients (14%) with BCV stenosis, two had >50% stenosis. Only one patient (2%) had mild stenosis of the SVC. Three patients out of 15 (20%) who had diagnostic venography for the IJV had severe stenosis of the vein. Pericatheter sleeve formation was more frequent in women (P<0.05). However, there were no statistical differences with respect to pericatheter sleeve formation, luminal filling

Feature-Based Analysis of Plasma-Based Particle Acceleration Data

Energy Technology Data Exchange (ETDEWEB)

Rubel, Oliver [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Geddes, Cameron G. R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chen, Min [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cormier-Michel, Estelle [Tech-X Corp., Boulder, CO (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2014-02-01

Plasma-based particle accelerators can produce and sustain thousands of times stronger acceleration fields than conventional particle accelerators, providing a potential solution to the problem of the growing size and cost of conventional particle accelerators. To facilitate scientific knowledge discovery from the ever growing collections of accelerator simulation data generated by accelerator physicists to investigate next-generation plasma-based particle accelerator designs, we describe a novel approach for automatic detection and classification of particle beams and beam substructures due to temporal differences in the acceleration process, here called acceleration features. The automatic feature detection in combination with a novel visualization tool for fast, intuitive, query-based exploration of acceleration features enables an effective top-down data exploration process, starting from a high-level, feature-based view down to the level of individual particles. We describe the application of our analysis in practice to analyze simulations of single pulse and dual and triple colliding pulse accelerator designs, and to study the formation and evolution of particle beams, to compare substructures of a beam and to investigate transverse particle loss.

Electron acceleration by turbulent plasmoid reconnection

Science.gov (United States)

Zhou, X.; Büchner, J.; Widmer, F.; Muñoz, P. A.

2018-04-01

In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury, energetic electrons are often found near current sheets, which hint at electron acceleration by magnetic reconnection. Unfortunately, electron acceleration by reconnection is not well understood yet, in particular, acceleration by turbulent plasmoid reconnection. We have investigated electron acceleration by turbulent plasmoid reconnection, described by MHD simulations, via test particle calculations. In order to avoid resolving all relevant turbulence scales down to the dissipation scales, a mean-field turbulence model is used to describe the turbulence of sub-grid scales and their effects via a turbulent electromotive force (EMF). The mean-field model describes the turbulent EMF as a function of the mean values of current density, vorticity, magnetic field as well as of the energy, cross-helicity, and residual helicity of the turbulence. We found that, mainly around X-points of turbulent reconnection, strongly enhanced localized EMFs most efficiently accelerated electrons and caused the formation of power-law spectra. Magnetic-field-aligned EMFs, caused by the turbulence, dominate the electron acceleration process. Scaling the acceleration processes to parameters of the Hermean magnetotail, electron energies up to 60 keV can be reached by turbulent plasmoid reconnection through the thermal plasma.

Accelerated irradiation growth of zirconium alloys

International Nuclear Information System (INIS)

Griffiths, M.; Gilbert, R.W.; Fidleris, V.

1989-01-01

This paper discusses how sponge zirconium and Zr-2.5 wt% Nb, Zircaloy, or Excel alloys all exhibit accelerated irradiation growth compared with high-purity crystal-bar zirconium for irradiation temperatures between 550 to 710 K and fluences between 0.1 to 10 x 10 25 n · m -2 (E > 1 MeV). There is generally an incubation period or fluence before the onset of accelerated or breakaway growth, which is dependent on the particular material being irradiated, its metallurgical condition before irradiation, and the irradiation temperature. Transmission electron microscopy has shown that there is a correlation between accelerated irradiation growth and the appearance of c-component vacancy loops on basal planes. Measurements in some specimens indicate that a significant fraction of the strain can be directly attributed to the loops themselves. There is considerable evidence to show that their formation is dependent both on the specimen purity and on the irradiation temperature. Materials that have a high interstitial-solute content contain c-component loops and exhibit high growth rates even at low fluences ( 2 :5 n · m -2 , E > 1 MeV). For sponge zirconium and the Zircaloys, c-component loop formation and the associated acceleration of growth (breakaway) during irradiation occurs because the intrinsic interstitial solute (mainly, oxygen, carbon and nitrogen) in the zirconium matrix is supplemented by interstitial iron, chromium, and nickel from the radiation-induced dissolution of precipitates. (author)

The electronic logbook for LNL accelerators

International Nuclear Information System (INIS)

Canella, S.; Carletto, O.

2012-01-01

In spring 2009 all run-time data concerning the particle accelerators at LNL (Legnaro National Laboratory) were still registered mainly on paper. The electrostatic accelerator TANDEM-XTU and its Negative Source data were logged on a large format paper logbook. For the ALPI booster and the PIAVE injector with its Positive ECR Source a number of independent paper notebooks were used, together with plain data files containing raw instant snapshots of the RF super-conductive accelerators. At that time a decision was taken to build a new tool for a general electronic registration of accelerators run-time data. The result of this effort, the LNL electronic logbook, is here presented. The LNL electronic logbook is a many-layers software tool that is made of data sets and software programs. It is used to register states, events, texts, images and files according to the shift structures in the working time of the LNL accelerators. The same system is used to register data and to retrieve them. It may be accessed by standard browser on any platform

Particle acceleration and wave emissions associated with the formation of auroral cavities and enhancements

International Nuclear Information System (INIS)

Winglee, R.M.; Pritchett, P.L.; Dusenbery, P.B.

1988-01-01

Observations from DE 1 and electrostatic particle simulations are combined in an effort to provide a unified model for (nightside) auroral particle acceleration and wave emissions and their association with plasma cavities and enhancements. The observations show that enhanced electron precipitation during inverted-V events is associated with broadband electrostatic bursts (BEB), increased upward field-aligned currents, and density enhancements. These regions are flanked by return current regions where the density is depleted (i.e., by plasma cavities). Perpendicular acceleration of ambient plasma ions can occur in both upward and return current regions. It is shown through the simulations that these processes are integrally related and are not independent of each other. The free energy for the auroral particle acceleration can be provided by energetic ion beams in the plasma sheet boundary layer with nonzero perpendicular energy. The perpendicular energy allows charge separation between the beam ions and costreaming electrons to occur. The resultant space charge fields accelerate electrons on the same field lines as the costreaming electrons downward toward the ionosphere, without the beam ions actually propagating down to auroral altitudes. Ambient plasma electrons on adjacent field lines are accelerated upward, forming a return current

On the mechanism of high-voltage discharge initiation in high-voltage accelerator accelerating tubes

International Nuclear Information System (INIS)

Zheleznikov, F.G.

1983-01-01

Experimental investigation into physical natupe of discharge processes in high-voltage accelerator accelerating tubes in the absence of the accelerated particle beam are conducted. The installation for the study of the mechanism of initiating vacuum isolation conductivity is used in the experiments. The vacuum chamber of the installation is made of steel and sealed with rubber packings. Electrodes 300-360 mm in diameter are made of stainless steel. Two variants of cleaning technology were used before electrode assembling: 1) degreasing by organic solvents; 2) cleaning by fine grinding cloth with successive washing by rectificated alcohol. Analysis of the obtained data shows that forma. tion of background flux of charged particles in interelectrode gap is caused by external photoelectric effect, excited by X radiation, which initiates the formation of intensive internal field in microfilms of non-conducting impurities on the electrode surfaces. The secondary electron emission plays the minor role at that

A novel thromboxane receptor antagonist, nstpbp5185, inhibits platelet aggregation and thrombus formation in animal models.

Science.gov (United States)

Huang, Shiu-Wen; Kuo, Heng-Lan; Hsu, Ming-Tsung; Tseng, Yufeng Jane; Lin, Shu-Wha; Kuo, Sheng-Chu; Peng, Hui-Chin; Lien, Jin-Cherng; Huang, Tur-Fu

2016-08-01

A novel benzimidazole derivative, nstpbp5185, was discovered through in vitro and in vivo evaluations for antiplatelet activity. Thromaboxane receptor (TP) is important in vascular physiology, haemostasis and pathophysiological thrombosis. Nstpbp5185 concentration-dependently inhibited human platelet aggregation caused by collagen, arachidonic acid and U46619. Nstpbp5185 caused a right-shift of the concentration-response curve of U46619 and competitively inhibited the binding of 3H-SQ-29548 to TP receptor expressed on HEK-293 cells, with an IC50 of 0.1 µM, indicating that nstpbp5185 is a TP antagonist. In murine thrombosis models, nstpbp5185 significantly prolonged the latent period in triggering platelet plug formation in mesenteric and FeCl3-induced thrombi formation, and increased the survival rate in pulmonary embolism model with less bleeding than aspirin. This study suggests nstpbp5185, an orally selective anti-thrombotic agent, acting through blockade of TXA2 receptor, may be efficacious for prevention or treatment of pathologic thrombosis.

Acceleration of compact torus plasma rings in a coaxial rail-gun

International Nuclear Information System (INIS)

Hartman, C.W.; Hammer, J.H.; Eddleman, J.

1986-01-01

They discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B/sub Theta/ flux from an accelerator bank. After acceleration, the rings enter a focusing cone where the ring is decelerated and reduced in radius. As the ring radius decreases, the ring magnetic energy increases until it equals the entering kinetic energy and the ring stagnates. Scaling laws and numerical calculations of acceleration using a O-D numerical code are presented. 2-D, MHD simulations are shown which demonstrate ring formation, acceleration, and focusing. Finally, 3-D calculations are discussed which determine the ideal MHD stability of the accelerated ring

Acceleration of compact torus plasma rings in a coaxial rail-gun

International Nuclear Information System (INIS)

Hartman, C.W.; Hammer, J.H.; Eddleman, J.

1985-01-01

We discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B/sub theta/ flux from an accelerator bank. After acceleration, the rings enter a focusing cone where the ring is decelerated and reduced in radius. As the ring radius decreases, the ring magnetic energy increases until it equals the entering kinetic energy and the ring stagnates. Scaling laws and numerical calculations of acceleration using a O-D numerical code are presented. 2-D, MHD simulations are shown which demonstrate ring formation, acceleration, and focusing. Finally, 3-D calculations are discussed which determine the ideal MHD stability of the accelerated ring

Clinical effect of selective thrombus aspiration during primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction

Directory of Open Access Journals (Sweden)

Hai-wei LIU

2015-06-01

Full Text Available Objective　To assess impact of selective thrombus aspiration (TA during primary percutaneous coronary intervention (pPCI on long-term prognosis in patients with ST-segment elevation myocardial infarction (STEMI. Methods　 Between Jan. 2008 and Jan. 2014, a total of 2357 STEMI patients [429 in thrombus aspiration (TA group and 1928 in routine percutaneous coronsry intorventim (PCI group (control group] were eligible for the study criteria and candidates for pPCI were enrolled in this study. The reflow of the involved vessel in pPCI procedure, stent thrombosis and major adverse cardiac events (MACE were comparatively analyzed in the two groups during hospital stay and 12-month follow-up period. Results　Although the success rate of TA procedure was significantly lower in TA group compared with that in control group (P＜0.001, both the TIMI flow grade ≥2 after TA procedure and stent implantation occurred more frequently in TA group than in control group (P＜0.05. The rates of MACE and stent thrombosis showed no difference between two groups during in-hospital and 12-month follow-up period (P>0.05. But the rates of total MACE and target vessel revascularization were significantly higher in control group than in TA group (P=0.04. Conclusion　Selective TA procedure before primary PCI could improve final myocardial reperfusion, reduce the incidence of MACE and improve the 1-year clinical result for STEMI patients. DOI: 10.11855/j.issn.0577-7402.2015.04.04

Adult Wilms tumor with inferior vena cava thrombus and distal deep vein thrombosis - a case report and literature review.

Science.gov (United States)

Ratajczyk, Krzysztof; Czekaj, Adrian; Rogala, Joanna; Kowal, Pawel

2018-02-23

Adult Wilms tumor (WT, nephroblastoma) is a rare, but well-described renal neoplasm. Although inferior vena cava tumor thrombosis is present in up to 10% of Wilms tumors in childhood, only few cases of this clinical manifestation in adults have been reported. To the best of our knowledge, this is the first case of adult WT infiltrating into inferior vena cava (IVC) with concomitant distal deep vein thrombosis. A 28-year-old male patient with gross hematuria and right flank pain was diagnosed with right kidney tumor penetrating to IVC. Preoperatively, acute distal thrombosis in inferior vena cava and lower extremities veins occurred. Right radical nephrectomy with tumor thrombectomy via cavotomy was performed. In order to prevent pulmonary embolism, IVC was ligated below left renal vein level. Histopathological examination revealed a triphasic nephroblastoma without anaplastic features. Postoperatively, patient was diagnosed with metastatic liver disease, which was treated with two lines of chemotherapy followed by radiotherapy with achievement of complete response. Adult WT occurs usually in young patients, under 40 years of age. Neoadjuvant chemotherapy proved to be effective in children, resulting with tumor shrinkage and venous tumor thrombus regression. Therefore, percutaneous biopsy should be always considered in young patients presenting with renal tumor invading venous system. IVC ligation is a safe treatment option in the event of complete inferior vena cava occlusion due to distal thrombosis concomitant to tumor thrombus, provided collateral venous pathways are well-developed.

Induced activity in accelerator structures, air and water

CERN Document Server

Stevenson, Graham Roger

2001-01-01

A summary is given of several 'rules of thumb' which can be used to predict the formation and decay of radionuclides in the structure of accelerators together with the dose rates from the induced radioactivity. Models are also given for the activation of gases (air of the accelerator vault) and liquids (in particular cooling water), together with their transport front the activation region to the release point. (18 refs).

Induced activity in accelerator structures, air and water

International Nuclear Information System (INIS)

Stevenson, G.R.

2001-01-01

A summary is given of several 'rules of thumb' which can be used to predict the formation and decay of radionuclides in the structure of accelerators together with the dose rates from the induced radioactivity. Models are also given for the activation of gases (air of the accelerator vault) and liquids (in particular cooling water), together with their transport from the activation region to the release point. (author)

Functional genomics in zebrafish permits rapid characterization of novel platelet membrane proteins.

Science.gov (United States)

O'Connor, Marie N; Salles, Isabelle I; Cvejic, Ana; Watkins, Nicholas A; Walker, Adam; Garner, Stephen F; Jones, Chris I; Macaulay, Iain C; Steward, Michael; Zwaginga, Jaap-Jan; Bray, Sarah L; Dudbridge, Frank; de Bono, Bernard; Goodall, Alison H; Deckmyn, Hans; Stemple, Derek L; Ouwehand, Willem H

2009-05-07

In this study, we demonstrate the suitability of the vertebrate Danio rerio (zebrafish) for functional screening of novel platelet genes in vivo by reverse genetics. Comparative transcript analysis of platelets and their precursor cell, the megakaryocyte, together with nucleated blood cell elements, endothelial cells, and erythroblasts, identified novel platelet membrane proteins with hitherto unknown roles in thrombus formation. We determined the phenotype induced by antisense morpholino oligonucleotide (MO)-based knockdown of 5 of these genes in a laser-induced arterial thrombosis model. To validate the model, the genes for platelet glycoprotein (GP) IIb and the coagulation protein factor VIII were targeted. MO-injected fish showed normal thrombus initiation but severely impaired thrombus growth, consistent with the mouse knockout phenotypes, and concomitant knockdown of both resulted in spontaneous bleeding. Knockdown of 4 of the 5 novel platelet proteins altered arterial thrombosis, as demonstrated by modified kinetics of thrombus initiation and/or development. We identified a putative role for BAMBI and LRRC32 in promotion and DCBLD2 and ESAM in inhibition of thrombus formation. We conclude that phenotypic analysis of MO-injected zebrafish is a fast and powerful method for initial screening of novel platelet proteins for function in thrombosis.

Application of Plasma Waveguides to High Energy Accelerators

Energy Technology Data Exchange (ETDEWEB)

Milchberg, Howard M

2013-03-30

The eventual success of laser-plasma based acceleration schemes for high-energy particle physics will require the focusing and stable guiding of short intense laser pulses in reproducible plasma channels. For this goal to be realized, many scientific issues need to be addressed. These issues include an understanding of the basic physics of, and an exploration of various schemes for, plasma channel formation. In addition, the coupling of intense laser pulses to these channels and the stable propagation of pulses in the channels require study. Finally, new theoretical and computational tools need to be developed to aid in the design and analysis of experiments and future accelerators. Here we propose a 3-year renewal of our combined theoretical and experimental program on the applications of plasma waveguides to high-energy accelerators. During the past grant period we have made a number of significant advances in the science of laser-plasma based acceleration. We pioneered the development of clustered gases as a new highly efficient medium for plasma channel formation. Our contributions here include theoretical and experimental studies of the physics of cluster ionization, heating, explosion, and channel formation. We have demonstrated for the first time the generation of and guiding in a corrugated plasma waveguide. The fine structure demonstrated in these guides is only possible with cluster jet heating by lasers. The corrugated guide is a slow wave structure operable at arbitrarily high laser intensities, allowing direct laser acceleration, a process we have explored in detail with simulations. The development of these guides opens the possibility of direct laser acceleration, a true miniature analogue of the SLAC RF-based accelerator. Our theoretical studies during this period have also contributed to the further development of the simulation codes, Wake and QuickPIC, which can be used for both laser driven and beam driven plasma based acceleration schemes. We

Coronary thrombus in 34-year-old female patient with 4G/4G polymorphism in the PAI-1 gene

Directory of Open Access Journals (Sweden)

Sinan Varol

2016-06-01

Full Text Available Genetic factors and hypofibrinolytic state may contribute to the likelihood of developing in myocardial infarction (MI in young women rather than traditional risk factors. High plasminogen-activator inhibitor-1 (PAI-1 level and PAI-1 gene polymorphism have been shown to be associated with thrombotic events such as myocardial infarction, deep venous thrombosis, and stroke. We determined 4G/4G polymorphism in a 34-year-old female patient with subacute anterior myocardial infarction and coronary thrombus in left anterior descending artery on coronary angiogram.

CT Findings of Intrarenal Yolk Sac Tumor with Tumor Thrombus Extending into the Inferior Vena Cava: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Lin, Shao Chun; Li, Xue Hua; Sun, Can Hui; Feng, Shi Ting; Peng, Zhen Peng; Huang, Si Yun; Li, Zi Ping [Dept. of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China)

2014-10-15

Yolk sac tumor (YST) is a rare germ cell neoplasm of childhood that usually arises from the testis or ovary. The rare cases of YST in various extragonadal locations have been reported, but the primary intrarenal YST is even more uncommon. Here, we report a case of a primary intrarenal YST with tumor thrombus of the inferior vena cava and left renal vein in a 2-year-old boy, with an emphasis on the CT features. To our knowledge, this is the first reported case of an intrarenal YST with intravascular involvement.

Left atrial appendage myxofibrosarcoma: A rare masquerader of myxoma and thrombus-"all that glitters is not gold".

Science.gov (United States)

Khan, Muhammad Shoaib; Reddy, Sahadev; Lombardi, Richard; Isabel, Pitti; Mcgregor, Walter E; Tang, Bang; Gabriel, George; Biederman, Robert W

2018-02-01

Left atrial appendage mass can occasionally pose a serious challenge to physicians to identify the nature of the mass with the aid of imaging techniques. We present a case of 67-year-old man, who was evaluated for suspected left atria myxoma. Transesophageal echocardiography revealed a heterogeneous density originating from left atrial appendage, thought to be most consistent with a myxoma. Cardiac magnetic resonance imaging, uncharacteristically, gave an equivocal picture, suggesting the mass to be a myxoma on initial imaging and a thrombus with evidence of liquefaction necrosis following postcontrast enhancement. Surprisingly, histopathology of the mass following its surgical excision yielded a rare diagnosis of myxofibrosarcoma. © 2017, Wiley Periodicals, Inc.

Numerical Simulation of Thrombotic Occlusion in Tortuous Arterioles

Science.gov (United States)

Feng, Zhi-Gang; Cortina, Miguel; Chesnutt, Jennifer KW; Han, Hai-Chao

2017-01-01

Tortuous microvessels alter blood flow and stimulate thrombosis but the physical mechanisms are poorly understood. Both tortuous microvessels and abnormally large platelets are seen in diabetic patients. Thus, the objective of this study was to determine the physical effects of arteriole tortuosity and platelet size on the microscale processes of thrombotic occlusion in microvessels. A new lattice-Boltzmann method-based discrete element model was developed to simulate the fluid flow field with fluid-platelet coupling, platelet interactions, thrombus formation, and thrombotic occlusion in tortuous arterioles. Our results show that vessel tortuosity creates high shear stress zones that activate platelets and stimulate thrombus formation. The growth rate depends on the level of tortuosity and the pressure and flow boundary conditions. Once thrombi began to form, platelet collisions with thrombi and subsequent activations were more important than tortuosity level. Thrombus growth narrowed the channel and reduced the flow rate. Larger platelet size leads to quicker decrease of flow rate due to larger thrombi that occluded the arteriole. This study elucidated the important roles that tortuosity and platelet size play in thrombus formation and occlusion in arterioles. PMID:29327739

Histopathological features of aspirated thrombi after primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction.

Directory of Open Access Journals (Sweden)

Miranda C Kramer

Full Text Available BACKGROUND: Plaque disruption with superimposed thrombus is the predominant mechanism responsible for the onset of acute coronary syndromes. Studies have shown that plaque disruption and thrombotic occlusion are frequently separated in time. We established the histopathological characteristics of material aspirated during primary percutaneous coronary intervention (PCI in a large consecutive ST-elevation myocardial infarction (STEMI population. METHODOLOGY/PRINCIPAL FINDINGS: Thrombus aspiration during primary PCI was performed in 1,362 STEMI patients. Thrombus age was classified as fresh (5 day. Further, the presence of plaque was documented. The histopathological findings were related to the clinical, angiographic, and procedural characteristics. Material could be aspirated in 1,009 patients (74%. Components of plaque were found in 395 of these patients (39%. Fresh thrombus was found in 577 of 959 patients (60% compared to 382 patients (40% with lytic or organized thrombi. Distal embolization was present in 21% of patients with lytic thrombus compared to 12% and 15% of patients with fresh or organized thrombus. CONCLUSIONS/SIGNIFICANCE: Material could be obtained in 74% of STEMI patients treated with thrombus aspiration during primary PCI. In 40% of patients thrombus age is older than 24 h, indicating that plaque disruption and thrombus formation occur significantly earlier than the onset of symptoms in many patients.

Effect of Cu4Ti compound formation on the characteristics of NbTi accelerator magnet wire

International Nuclear Information System (INIS)

Garber, M.; Suenaga, M.; Sampson, W.B.; Sabatini, R.L.

1985-01-01

High critical current density, J/sub c/ > 2500 A/mm 2 , and small filament diameter, d approx. 3 μm, are required in multifilamentary NbTi wire used for superconducting accelerator magnets. Wires obtained from various commercial sources had J/sub c/'s in the range 1000 to 2800 A/mm 2 amd d's in the range 1 to 23 μm. The filaments were examined by means of scanning electron microscopy in order to determine the reason for the variation in J/sub c/. It was found that the filaments in high J/sub c/ wires had clean smooth surfaces and uniform cross section along their lengths. Filaments in low J/sub c/ wires show formation of Cu 4 Ti compound particles on their surfaces and large variations in cross section. The lower critical current measured in these wires is believed to be largely due to this effect. The superconducting-normal state transition is relatively wide in these wires

Formation of spectrum of accelerated particles and the hydromagnetic turbulence in the variable magnetic field

International Nuclear Information System (INIS)

Savane, Y. Sy; Diaby, I.; Faza Barry, M.; Lomonossov, V.

2002-11-01

We study the acceleration of charged particles by the variable magnetic field. The study is based on the determination of spectrum of accelerated particles and the spectrum of hydro magnetic turbulence. We plan the self-consistent system of equation and we also find out the solution of the system for the spectrum of particles and hydro magnetic turbulence with the conditions of effective acceleration in the cosmic space of solar system. (author)

Capabilities of diffusion-weighted and fresh blood imaging in depicting fresh thrombus. Presidential award proceedings

International Nuclear Information System (INIS)

Ando, Ritsuko; Manabe, Tsutomu; Tazawa, Satoru

2007-01-01

We examined the capabilities of diffusion-weighted (DWI) and fresh-blood imaging (FBI) in depicting thrombus. A paper-clay phantom holding test syringes of various sizes filled with either contrast medium or fresh human blood were scanned using a 1.5T magnetic resonance (MR) imaging unit, and apparent diffusion coefficient (ADC) values and signal intensities on DWI and FBI of the specimens were obtained. FBI depicted all the specimens regardless of syringe diameter, but DWI failed to image the syringe measuring 0.5 cm in diameter. B-factors and/or number of acquisitions (NAQ) seemed responsible for DWI's depiction capability. ADC values and signal intensities on DWI and FBI correlated with the viscosity of the contrast medium samples. Clotted blood, the most viscous of the samples, had the smallest ADC value and no relationship with signal intensities on DWI and FBI. Larger b-factors reduced signal intensity in contrast medium on DWI, but signals decreased only minimally in clotted blood. The result suggested that although viscosity was the influential factor for signal intensities on DWI in contrast medium, other factors, such as particle sizes of fibrin and hemoglobin, accounted for the low ADC values in clotting blood. T 2 relaxation time seemed to play a significant role in making signal intensities on DWI irrelevant to b-factors. Despite lapsed time, the clots were persistently hyperintense on FBI with a tendency to decrease only gradually. On DWI, there was a certain period when signal intensities were high and ADC values were low. The signal intensities on DWI and ADC values were considered to be influenced by the process of clot formation, and disappearance of signal seemed likely attributable to degeneration of protein and organization of the clot. (author)

Coronary artery stent mimicking intracardiac thrombus on cardiac magnetic resonance imaging due to signal loss

DEFF Research Database (Denmark)

Qayyum, Abbas Ali; Vejlstrup, Niels Grove; Ahtarovski, Kiril Aleksov

2012-01-01

Since the introduction of percutaneous coronary intervention for coronary artery disease, thousands of patients have been treated with the implantation of coronary stents. Moreover, several of the patients with coronary stent undergo cardiac magnetic resonance (CMR) imaging every year. This case...... report is of a 77-year-old man who was previously treated with the implantation of a coronary stent in the left circumflex artery. He underwent CMR imaging, which revealed a process 14×21 mm in the left atrium. Cardiac contrast computed tomography did not demonstrate any cardiac pathology. While...... the signal loss on MRI associated with implanted metallic devices is known, we report a case where an implanted coronary stent in the left circumflex artery led to an intracardiac signal loss mimicking intracardiac thrombus/tumor....

Diesel engine exhaust accelerates plaque formation in a mouse model of Alzheimer's disease.

Science.gov (United States)

Hullmann, Maja; Albrecht, Catrin; van Berlo, Damiën; Gerlofs-Nijland, Miriam E; Wahle, Tina; Boots, Agnes W; Krutmann, Jean; Cassee, Flemming R; Bayer, Thomas A; Schins, Roel P F

2017-08-30

Increasing evidence from toxicological and epidemiological studies indicates that the central nervous system is an important target for ambient air pollutants. We have investigated whether long-term inhalation exposure to diesel engine exhaust (DEE), a dominant contributor to particulate air pollution in urban environments, can aggravate Alzheimer's Disease (AD)-like effects in female 5X Familial AD (5XFAD) mice and their wild-type female littermates. Following 3 and 13 weeks exposures to diluted DEE (0.95 mg/m 3 , 6 h/day, 5 days/week) or clean air (controls) behaviour tests were performed and amyloid-β (Aβ) plaque formation, pulmonary histopathology and systemic inflammation were evaluated. In a string suspension task, assessing for grip strength and motor coordination, 13 weeks exposed 5XFAD mice performed significantly less than the 5XFAD controls. Spatial working memory deficits, assessed by Y-maze and X-maze tasks, were not observed in association with the DEE exposures. Brains of the 3 weeks DEE-exposed 5XFAD mice showed significantly higher cortical Aβ plaque load and higher whole brain homogenate Aβ42 levels than the clean air-exposed 5XFAD littermate controls. After the 13 weeks exposures, with increasing age and progression of the AD-phenotype of the 5XFAD mice, DEE-related differences in amyloid pathology were no longer present. Immunohistochemical evaluation of lungs of the mice revealed no obvious genetic background-related differences in tissue structure, and the DEE exposure did not cause histopathological changes in the mice of both backgrounds. Luminex analysis of plasma cytokines demonstrated absence of sustained systemic inflammation upon DEE exposure. Inhalation exposure to DEE causes accelerated plaque formation and motor function impairment in 5XFAD transgenic mice. Our study provides further support that the brain is a relevant target for the effects of inhaled DEE and suggests that long-term exposure to this ubiquitous air

Zinc oxide nanoparticles induce migration and adhesion of monocytes to endothelial cells and accelerate foam cell formation

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Yuka; Tada-Oikawa, Saeko [Graduate School of Regional Innovation Studies, Mie University, Tsu (Japan); Ichihara, Gaku [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya (Japan); Yabata, Masayuki; Izuoka, Kiyora [Graduate School of Regional Innovation Studies, Mie University, Tsu (Japan); Suzuki, Masako; Sakai, Kiyoshi [Nagoya City Public Health Research Institute, Nagoya (Japan); Ichihara, Sahoko, E-mail: saho@gene.mie-u.ac.jp [Graduate School of Regional Innovation Studies, Mie University, Tsu (Japan)

2014-07-01

Metal oxide nanoparticles are widely used in industry, cosmetics, and biomedicine. However, the effects of exposure to these nanoparticles on the cardiovascular system remain unknown. The present study investigated the effects of nanosized TiO{sub 2} and ZnO particles on the migration and adhesion of monocytes, which are essential processes in atherosclerogenesis, using an in vitro set-up of human umbilical vein endothelial cells (HUVECs) and human monocytic leukemia cells (THP-1). We also examined the effects of exposure to nanosized metal oxide particles on macrophage cholesterol uptake and foam cell formation. The 16-hour exposure to ZnO particles increased the level of monocyte chemotactic protein-1 (MCP-1) and induced the migration of THP-1 monocyte mediated by increased MCP-1. Exposure to ZnO particles also induced adhesion of THP-1 cells to HUVECs. Moreover, exposure to ZnO particles, but not TiO{sub 2} particles, upregulated the expression of membrane scavenger receptors of modified LDL and increased cholesterol uptake in THP-1 monocytes/macrophages. In the present study, we found that exposure to ZnO particles increased macrophage cholesterol uptake, which was mediated by an upregulation of membrane scavenger receptors of modified LDL. These results suggest that nanosized ZnO particles could potentially enhance atherosclerogenesis and accelerate foam cell formation. - Highlights: • Effects of metal oxide nanoparticles on foam cell formation were investigated. • Exposure to ZnO nanoparticles induced migration and adhesion of monocytes. • Exposure to ZnO nanoparticles increased macrophage cholesterol uptake. • Expression of membrane scavenger receptors of modified LDL was also increased. • These effects were not observed after exposure to TiO{sub 2} nanoparticles.

Progress In Plasma Accelerator Development for Dynamic Formation of Plasma Liners

Science.gov (United States)

Thio, Y. C. Francis; Eskridge, Richard; Martin, Adam; Smith, James; Lee, Michael; Cassibry, Jason T.; Griffin, Steven; Rodgers, Stephen L. (Technical Monitor)

2002-01-01

An experimental plasma accelerator for magnetic target fusion (MTF) applications under development at the NASA Marshall Space Flight Center is described. The accelerator is a coaxial pulsed plasma thruster (Figure 1). It has been tested experimentally and plasma jet velocities of approx.50 km/sec have been obtained. The plasma jet has been photographed with 10-ns exposure times to reveal a stable and repeatable plasma structure (Figure 2). Data for velocity profile information has been obtained using light pipes and magnetic probes embedded in the gun walls to record the plasma and current transit respectively at various barrel locations. Preliminary spatially resolved spectral data and magnetic field probe data are also presented. A high speed triggering system has been developed and tested as a means of reducing the gun "jitter". This jitter is being characterized and future work for second generation "ultra-low jitter" gun development is being identified.

Linear accelerator for burner-reactor

International Nuclear Information System (INIS)

Batskikh, G.I.; Murin, B.P.; Fedotov, A.P.

1991-01-01

Future development of nuclear power engineering depends on the successful solution of two key problems of safety and utilization of high level radioactive wastes (HLRW) of atomic power plants (APP). Modern methods of HLRW treatment involve solidification, preliminary storing for a period of 30-50 years necessary for the decay of long-living nuclides and final burial in geological formations several hundred meters below the ground surface. The depth burial of the radioactive wastes requires complicated under ground constructions. It's very expensive and doesn't meet modern ecological requirements. Alternative modern and more reasonable methods of APP HLRW treatment are under consideration now. One of the methods involves separation of APP waste radionuclides for use in economy with subsequent transmutation of the long-living isotopes into the short-living ones by high-intensity neutron fluxes generated by proton accelerators. The installation intended for the long-living radionuclides transmutation into the short-living ones is called burner-reactor. It can be based on the continuous regime proton accelerator with 1.5 GeV energy, 0.3 A current and beam mean power of 450 MW. The preferable type of the proton accelerator with the aforementioned parameters is the linear accelerator

Vessel wall and indium-111-labelled platelet response to carotid endarterectomy

International Nuclear Information System (INIS)

Lusby, R.J.; Ferrell, L.D.; Englestad, B.L.; Price, D.C.; Lipton, M.J.; Stoney, R.J.

1983-01-01

Postendarterectomy platelet deposition and thrombus formation may play an important role not only in vessel wall healing but also in the small incidence of postoperative cerebral ischemia and postoperative stenosis. A study has been performed using a canine model to investigate the healing response to carotid endarterectomy and the validity of an in vivo indium-111 (In-111) radiotracer technique in the assessment of postendarterectomy deposition of autologous labelled platelets. Sixteen endarterectomized carotid arteries showed uptake of autologous In-111 platelets immediately after infusion, reaching a maximum by 1 hour with little increase at 24 or 48 hours. No uptake was seen in ten control vessels following platelet infusion (P less than 0.05). At autopsy, seven vessels were demonstrated to have In-111 platelet deposition immediately prior to sacrifice of the animals. Postmortem scanning confirmed the localization to the vessel lumens, and microscopy revealed thrombus formation with or without partial endothelialization. Complete reendothelialization had occurred in the vessels that failed to show platelet deposition. Delayed healing was associated with continuing platelet deposition, excessive thrombus formation, and luminal stenosis. Arteriotomy closure with a vein patch altered the healing characteristics of the vessel with segmental thrombus formation over the vein patch. A preliminary study of the postendarterectomy in vivo In-111 platelet response in humans demonstrated platelet deposition that was not influenced by the administration of antiplatelet drugs at currently prescribed levels

The programmed nursing care for lower extremity deep venous thrombus patients receiving interventional thrombolysis: its effect on living quality

International Nuclear Information System (INIS)

Qiao Cuiyun; Wang Zhujun; Lan Guiyun; Liang Zhiqiang; Shi Yonmin

2011-01-01

Objective: Tu study the effect of comprehensive programmed nursing intervention on the living quality in patients with lower extremity deep venous thrombus who receive interventional thrombolysis therapy. Methods: A total of 60 patients receiving interventional thrombolysis due to lower extremity deep venous thrombus were randomly and equally divided into two groups. Patients in study group (n=30) was treated with comprehensive programmed nursing intervention in addition to the conventional therapy and routine nursing care, while patients in control group (n=30) was treated with the conventional therapy and routine nursing care only. The conventional therapy and routine nursing care included the nursing assessment before the operation, observation of the vital signs and the cooperation psychological care during the operation, the performance of medication according to the doctor's orders after the operation, etc. The comprehensive programmed nursing intervention included the nursing assessment of the patient before operation and the scientifically making of the nursing plan, which mainly referred to the cognitive behavior, the psychological care and the health education. They were systematically carried out during the perioperative period. One month after discharge the patients were asked to pay a return visit. The living quality was evaluated with relevant standards, and the results were compared between the two groups. Results: The score of living quality in the study group was significantly higher than that in the control group (P<0.01). Conclusion: The comprehensive programmed nursing intervention can significantly improve the living quality of lower extremity deep venous thrombosis patients who receive interventional thrombolysis therapy. (authors)

Pancreatic endocrine tumor with neoplastic venous thrombus and bilobar liver metastasis. A case report.

Science.gov (United States)

Barbier, L; Turrini, O; Sarran, A; Delpero, J-R

2010-02-01

We report the case of an asymptomatic 56-year-old woman with a metastatic pancreatic endocrine tumor, fortuitously discovered by abdominal imaging. A CT-scan showed a large mass in the pancreatic tail invading the spleen and stomach; in addition, there was neoplastic thrombus within the spleno-mesentericoportal venous confluence and bilobar liver metastases. Surgical resection was performed in two stages. The first procedure was an extended left pancreatectomy with venous thrombectomy and "clearance" of the left hepatic lobe. During the interval, embolization of the right portal vein was carried out. Right hepatectomy and radiofrequency destruction of residual metastases was then performed. On the basis of completeness of the resection and the histopathological data, the patient did not undergo any adjuvant therapy, in accordance with French guidelines. At 1 year of follow-up, there was no evidence of recurrence. (c) 2010 Elsevier Masson SAS. All rights reserved.

IFMIF accelerators design

International Nuclear Information System (INIS)

Mosnier, A.; Ratzinger, U.

2008-01-01

The IFMIF requirement for 250 mA current of deuteron beams at a nominal energy of 40 MeV is met by means of two identical continuous wave (CW) 175 MHz linear accelerators running in parallel, each delivering a 125 mA, 40 MeV deuteron beam to the common target. This approach allows to stay within the current capability of present RF linac technology while providing operational redundancy in case of failure of one of the linacs. Each linac comprises a sequence of acceleration and beam transport/matching stages. The ion source generates a 140 mA deuteron beam at 100 keV. A low energy beam transport (LEBT) transfers the deuteron beam from the source to a radio frequency quadrupole (RFQ) cavity. The RFQ bunches and accelerates the 125 mA beam to 5 MeV. The RFQ output beam is injected through a matching section into a drift-tube-linac (DTL) where it is accelerated to the final energy of 40 MeV. In the reference design, the final acceleration stage is a conventional Alvarez-type DTL with post-couplers operating at room temperature. Operation of both the RFQ and the DTL at the same relatively low frequency is essential for accelerating the high current deuteron beam with low beam loss. The primary concern of the IFMIF linacs is the minimization of beam losses, which could limit their availability and maintainability due to excessive activation of the linac and irradiation of the environment. A careful beam dynamics design is therefore needed from the source to the target to avoid the formation of particle halo that could finally be lost in the linac or transfer lines. A superconducting solution for the high energy portion of the linac using, for example, CH-structure or coaxial-type resonators, could offer some advantages, in particular the reduction of operational costs. Careful beam dynamics simulations and comparison tests with beam during the EVEDA phase are however necessary in order to fully assess the technical feasibility of such alternative solutions

Compact torus accelerator as a driver for ICF

International Nuclear Information System (INIS)

Tobin, M.T.; Meier, W.R.; Morse, E.C.

1986-01-01

The authors have carried out further investigations of the technical issues associated with using a compact torus (CT) accelerator as a driver for inertial confinement fusion (ICF). In a CT accelerator, a magnetically confined, torus-shaped plasma is compressed, accelerated, and focused by two concentric electrodes. After its initial formation, the torus shape is maintained for lifetimes exceeding 1 ms by inherent poloidal and toroidal currents. Hartman suggests acceleration and focusing of such a plasma ring will not cause dissolution within certain constraints. In this study, we evaluated a point design based on an available capacitor bank energy of 9.2 MJ. This accelerator, which was modeled by a zero-dimensional code, produces a xenon plasma ring with a 0.73-cm radius, a velocity of 4.14 x 10 9 cm/s, and a mass of 4.42 μg. The energy of the plasma ring as it leaves the accelerator is 3.8 MJ, or 41% of the capacitor bank energy. Our studies confirm the feasibility of producing a plasma ring with the characteristics required to induce fusion in an ICF target with a gain greater than 50. The low cost and high efficiency of the CT accelerator are particularly attractive. Uncertainties concerning propagation, accelerator lifetime, and power supply must be resolved to establish the viability of the accelerator as an ICF driver

An experimental study on MR imaging of jugular venous thrombosis in dogs

International Nuclear Information System (INIS)

Lee, Joo Hyuk; Choi, Sin Eun; Park, Jae Hyung; Kim, Jae Seung; Lee, Sun Gyu; Chang, Kee Hyun

1993-01-01

This study was designed to evaluate the potential application of MRI in differentiating static blood from thrombus, age-related changes of thrombus and the signal differences of the intravascular thrombus in various pulse sequences. External jugular vein was ligated at both upper and lower ends to from a static blood column, and thrombin was injected into the column to cause venous thrombosis in a total of 15 mongrel dogs. The MR images were obtained with T1- and T2-weighted spin echo and gradient echo techniques, lmmediately after the formation of static blood and after 2 hour, 1 day, 1 week, 2 weeks and 4 weeks of the formation of thrombus at a 2.0 T MR unit. The signal intensities of the thrombus and adjacent muscles were compared subjectively, and the signal intensity ratio was compared objectively by the measurement of the signal intensities using a cursor. The MRI findings were compared with histologic findings. The signal intensities of static blood were hyperintense in all pulse sequences, and those of 2 hour, 1 day and 1 week old thrombi were hyperintense in all pulse sequence. The number of experimental thrombi which showed isointensity on T1- and T2-weighted image, and hyperintensity on gradient echo image increased as thrombi aged. The signal intensities of 2 week old thrombus were isointense on T1-weighted image, hyperintense on T2-weighted image, and hyperintense on gradient echo image, while those of 4 week old thrombus were isointense on T1-weighted and T2-weighted image, and hypointense on gradient echo image in most experimental thrombi. There was a tendency to decrease in a signal intensity ratio as thrombi aged on T1-weighted, T2-weighted and gradient echo images(p<0.01). Histologically, thrombus was not formed and lumen was filled with many red blood cells(RBCs) in 2 hour old specimen, but fibrin mesh was visible and RBCs decreased in number in 1 day old specimen. In 1 week old specimen, vessel was contrasted and lumen was filled with thrombus

Accelerated Threshold Fatigue Crack Growth Effect-Powder Metallurgy Aluminum Alloy

Science.gov (United States)

Piascik, R. S.; Newman, J. A.

2002-01-01

Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low (Delta) K, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = K(sub min)/K(sub max)). The near threshold accelerated FCG rates are exacerbated by increased levels of K(sub max) (K(sub max) = 0.4 K(sub IC)). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and K(sub max) influenced accelerated crack growth is time and temperature dependent.

AngioVac Aspiration for Paradoxical Emboli Protection through a Fenestrated Fontan During Central Venous Thrombus Manipulation

Energy Technology Data Exchange (ETDEWEB)

Al-Hakim, Ramsey, E-mail: ralhakim@mednet.ucla.edu [University of California, Department of Radiology, Division of Interventional Radiology (United States); Patel, Komal, E-mail: kdpatel@mednet.ucla.edu [University of California, Department of Anesthesiology, Division of Cardiothoracic Anesthesiology (United States); Moriarty, John M., E-mail: jmoriarty@mednet.ucla.edu [University of California, Department of Radiology, Division of Interventional Radiology (United States)

2015-06-15

This case reports describes a 39-year-old female with a history of surgically repaired hypoplastic left heart syndrome who presented with a left peripherally inserted central catheter (PICC) with associated large volume subclavian and brachiocephalic vein thrombus. Due to the presence of a right-to-left shunt via a fenestrated Fontan, there was clinical concern for a paradoxical embolism during removal of the PICC. The AngioVac aspiration system was successfully utilized to aspirate thromboemboli from the level of the proximal Glenn shunt during manipulation and removal of the PICC. This is the first reported case to demonstrate the safe and effective use of the AngioVac aspiration system for protection of paradoxical emboli through a cardiac right-to-left shunt during a procedure at high risk for thromboembolism.

Successful Percutaneous Coronary Intervention through a Severely Bent Artificial Ascending Aorta Using the DIO Thrombus Aspiration Catheter

Directory of Open Access Journals (Sweden)

Akinori Fujikake

2016-01-01

Full Text Available A 66-year-old man was admitted to our institute because of chest pain. He had undergone replacement of the ascending aorta due to aortic dissection 9 years previously. We made a diagnosis of acute coronary syndrome, and coronary artery angiography was performed. Although the right coronary artery was successfully cannulated, a severe bend of the artificial aorta made it very difficult to advance the catheter into the left coronary artery. Ultimately, a DIO thrombus aspiration catheter was used to enter the left coronary artery, and a stent was implanted successfully. The DIO catheter is very useful when the selection of a guiding catheter is complicated, such as in the case of severe vessel tortuosity or a bend of the ascending aorta.

A systematic FPGA acceleration design for applications based on convolutional neural networks

Science.gov (United States)

Dong, Hao; Jiang, Li; Li, Tianjian; Liang, Xiaoyao

2018-04-01

Most FPGA accelerators for convolutional neural network are designed to optimize the inner acceleration and are ignored of the optimization for the data path between the inner accelerator and the outer system. This could lead to poor performance in applications like real time video object detection. We propose a brand new systematic FPFA acceleration design to solve this problem. This design takes the data path optimization between the inner accelerator and the outer system into consideration and optimizes the data path using techniques like hardware format transformation, frame compression. It also takes fixed-point, new pipeline technique to optimize the inner accelerator. All these make the final system's performance very good, reaching about 10 times the performance comparing with the original system.

Accelerating anodic biofilms formation and electron transfer in microbial fuel cells: Role of anionic biosurfactants and mechanism.

Science.gov (United States)

Zhang, Yunshu; Jiang, Junqiu; Zhao, Qingliang; Gao, YunZhi; Wang, Kun; Ding, Jing; Yu, Hang; Yao, Yue

2017-10-01

Anodic electron transfer is the predominant electricity generation process of MFCs. To accelerate anodic biofilms formation and electron transfer, 40mg/L, 80mg/L, and 120mg/L of rhamnolipid biosurfactants were added to the anolyte, resulting in an increased abiotic capacitance from 15.12F/m 2 (control) to 16.54F/m 2 , 18.00F/m 2 , and 19.39F/m 2 , respectively. Anodic biofilm formation was facilitated after dosing 40mg/L of rhamnolipids on the 7th day after inoculation, resulting in an increased anodic biofilm coverage from 0.43% to 42.51%, and an increased maximum power density from 6.92±1.18W/m 3 to 9.93±0.88W/m 3 . Furthermore, the adsorption of rhamnolipids on the anode caused the Frumkin effect, leading to a decrease of equilibrium potential from -0.43V to -0.56V, and an increase of exchange current density from 5.09×10 -3 A/m 2 to 8.72×10 -3 A/m 2 . However, electron transfer was blocked when the rhamnolipid concentration was further increased to 80mg/L, and 120mg/L. Analysis of the anodic bacterial communities revealed that rhamnolipids facilitated the enrichment of exoelectrogen, increasing the total proportion from 65% to 81%. Additionally, biosurfactants were found to have significant impacts on the composition of exoelectrogens. Copyright © 2017 Elsevier B.V. All rights reserved.

Rivaroxaban as an Antithrombotic Agent in a Patient With ST-Segment Elevation Myocardial Infarction and Left Ventricular Thrombus

Directory of Open Access Journals (Sweden)

Rajeev Seecheran

2017-03-01

Full Text Available The incidence of left ventricular (LV thrombi in the setting of an anterior myocardial infarction has declined significantly since the advent of primary percutaneous coronary intervention coupled with contemporary antithrombotic strategies in ST-segment elevation myocardial infarctions (STE-ACS. Despite oral anticoagulation with the currently accepted, standard-of-care vitamin K antagonist, warfarin, major bleeding complications still arise. Rivaroxaban is a novel, direct oral factor X anticoagulant that has several advantageous properties, which can attenuate bleeding risk. We present a case in which a patient successfully underwent a 3-month course of rivaroxaban in addition to his dual antiplatelet regimen of aspirin and ticagrelor for his STE-ACS and LV thrombus with resultant complete dissolution.

Comparative evaluation of direct thrombin and factor Xa inhibitors with antiplatelet agents under flow and static conditions: an in vitro flow chamber model.

Directory of Open Access Journals (Sweden)

Kazuya Hosokawa

Full Text Available Dabigatran and rivaroxaban are novel oral anticoagulants that specifically inhibit thrombin and factor Xa, respectively. The aim of this study is to elucidate antithrombotic properties of these anticoagulant agents under arterial and venous shear conditions. Whole blood samples treated with dabigatran or rivaroxaban at 250, 500, and 1000 nM, with/without aspirin and AR-C66096, a P2Y12 antagonist, were perfused over a microchip coated with collagen and tissue thromboplastin at shear rates of 240 and 600 s(-1. Fibrin-rich platelet thrombus formation was quantified by monitoring flow pressure changes. Dabigatran at higher concentrations (500 and 1000 nM potently inhibited thrombus formation at both shear rates, whereas 1000 nM of rivaroxaban delayed, but did not completely inhibit, thrombus formation. Dual antiplatelet agents weakly suppressed thrombus formation at both shear rates, but intensified the anticoagulant effects of dabigatran and rivaroxaban. The anticoagulant effects of dabigatran and rivaroxaban were also evaluated under static conditions using thrombin generation (TG assay. In platelet-poor plasma, dabigatran at 250 and 500 nM efficiently prolonged the lag time (LT and moderately reduce peak height (PH of TG, whereas rivaroxaban at 250 nM efficiently prolonged LT and reduced PH of TG. In platelet-rich plasma, however, both anticoagulants efficiently delayed LT and reduced PH of TG. Our results suggest that dabigatran and rivaroxaban may exert distinct antithrombotic effects under flow conditions, particularly in combination with dual antiplatelet therapy.

Plasma Accelerator Development for Dynamic Formation of Plasma Liners: A Status Report

Science.gov (United States)

Thio, Y. C. Francis; Eskridge, Richard; Martin, Adam; Smith, James; Lee, Michael; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

An experimental plasma accelerator for magnetic target fusion (MTF) applications under development at the NASA Marshall Space Flight Center is described. The accelerator is a pulsed plasma thruster and has been tested experimentally and plasma jet velocities of approximately 50 km/sec have been obtained. The plasma jet structure has been photographed with 10 ns exposure times to reveal a stable and repeatable plasma structure. Data for velocity profile information has been obtained using light pipes embedded in the gun walls to record the plasma transit at various barrel locations. Preliminary spatially resolved spectral data and magnetic field probe data are also presented. A high speed triggering system has been developed and tested as a means of reducing the gun "jitter". This jitter is being characterized and future work for second generation "ultra-low jitter" gun development is being identified.

Current Fragmentation and Particle Acceleration in Solar Flares

Science.gov (United States)

Cargill, P. J.; Vlahos, L.; Baumann, G.; Drake, J. F.; Nordlund, Å.

2012-11-01

Particle acceleration in solar flares remains an outstanding problem in plasma physics and space science. While the observed particle energies and timescales can perhaps be understood in terms of acceleration at a simple current sheet or turbulence site, the vast number of accelerated particles, and the fraction of flare energy in them, defies any simple explanation. The nature of energy storage and dissipation in the global coronal magnetic field is essential for understanding flare acceleration. Scenarios where the coronal field is stressed by complex photospheric motions lead to the formation of multiple current sheets, rather than the single monolithic current sheet proposed by some. The currents sheets in turn can fragment into multiple, smaller dissipation sites. MHD, kinetic and cellular automata models are used to demonstrate this feature. Particle acceleration in this environment thus involves interaction with many distributed accelerators. A series of examples demonstrate how acceleration works in such an environment. As required, acceleration is fast, and relativistic energies are readily attained. It is also shown that accelerated particles do indeed interact with multiple acceleration sites. Test particle models also demonstrate that a large number of particles can be accelerated, with a significant fraction of the flare energy associated with them. However, in the absence of feedback, and with limited numerical resolution, these results need to be viewed with caution. Particle in cell models can incorporate feedback and in one scenario suggest that acceleration can be limited by the energetic particles reaching the condition for firehose marginal stability. Contemporary issues such as footpoint particle acceleration are also discussed. It is also noted that the idea of a "standard flare model" is ill-conceived when the entire distribution of flare energies is considered.

In situ acceleration in extragalactic radio jets

International Nuclear Information System (INIS)

Bicknell, G.V.; Melrose, D.B.

1982-01-01

We have examined the energy dissipated by large-scale turbulence in an extragalactic jet. The turbulence is driven by a shear instability which does not disrupt the jet. Fluid theory should be used to treat the evolution of the turbulence, and this allows us to estimate the rate of dissipation without detailed knowledge of the dissipation process. Dissipation occurs due to Fermi acceleration at a scale length approx.10 -3 R and that resonant acceleration plays no role. The Alfvenic component in the turbulent spectrum is dissipated by first being converted into magneto-acoustic waves. An alternative dissipation process due to formation of weak shocks is shown to be equivalent in some respects to Fermi acceleration. Dissipation in the thermal gas should not exceed that due to Fermi acceleration. The effect of Fermi acceleration, adiabatic losses, and radiative losses on an initial power-law distribution with an upper cutoff is studied. Radio emission extending to at least 100 GHz is shown to be possible, and no spectral index gradients are introduced by the acceleration. The upper cutoff can increase due to the acceleration alone or when the acceleration is balanced by radiative losses. The northern jet in NGC 315 is studied in detail. Using our model for the acceleration, we estimate a jet velocity > or approx. =5000 km s -1 with Mach number not much greater than 1, and a density -4 f -1 cm -3 at the turn-on of the jet at 6 cm, where 0.05 5 yr, and it is predicted that the radius of the jet at the turn-on point should vary with frequency either as ν/sup 2/3/ or as ν/sup 3/2/, or there may be no frequency dependence, contingent upon the details of the acceleration

A New Paradigm for Flare Particle Acceleration

Science.gov (United States)

Guidoni, Silvina E.; Karpen, Judith T.; DeVore, C. Richard

2017-08-01

The mechanism that accelerates particles to the energies required to produce the observed high-energy impulsive emission and its spectra in solar flares is not well understood. Here, we propose a first-principle-based model of particle acceleration that produces energy spectra that closely resemble those derived from hard X-ray observations. Our mechanism uses contracting magnetic islands formed during fast reconnection in solar flares to accelerate electrons, as first proposed by Drake et al. (2006) for kinetic-scale plasmoids. We apply these ideas to MHD-scale islands formed during fast reconnection in a simulated eruptive flare. A simple analytic model based on the particles’ adiabatic invariants is used to calculate the energy gain of particles orbiting field lines in our ultrahigh-resolution, 2.5D, MHD numerical simulation of a solar eruption (flare + coronal mass ejection). Then, we analytically model electrons visiting multiple contracting islands to account for the observed high-energy flare emission. Our acceleration mechanism inherently produces sporadic emission because island formation is intermittent. Moreover, a large number of particles could be accelerated in each macroscopic island, which may explain the inferred rates of energetic-electron production in flares. We conclude that island contraction in the flare current sheet is a promising candidate for electron acceleration in solar eruptions. This work was supported in part by the NASA LWS and H-SR programs..

Novel microspheres reduce the formation of deep venous thrombosis and repair the vascular wall in a rat model.

Science.gov (United States)

Dai, Bingyang; Li, Lan; Li, Qiangqiang; Song, Xiaoxiao; Chen, Dongyang; Dai, Jin; Yao, Yao; Yan, Wenjin; Teng, Huajian; Yang, Fang; Xu, Zhihong; Jiang, Qing

2017-07-01

: L-Arginine (L-arg), widely known as a substrate for endogenous nitric oxide synthesis, can improve endothelial function associated with the vasculature, inhibit platelet aggregation, and alter the activity of vascular smooth muscle cells. P-selectin is a membrane component of the platelet alpha-granule and the endothelial cell-specific Wiebel-Palade body that plays a central role in mediating interactions between platelets and both leukocytes and the endothelium. The experiment was designed to evaluate the effect of novel microspheres with L-arg targeting P-selectin on the formation of deep vein thrombosis and repair of vascular wall in a rat model. Thrombosis of the inferior vena cava was induced by applying a piece of filter paper (5 mm × 10 mm) saturated with 10% FeCl3 solution for 5 min. Targeted microspheres with L-arg, targeted microspheres with water, and saline were injected into the tail veins of the rats after 30 min of applying the filter paper saturated with 10% FeCl3 solution. The dry weight and length of the thrombus isolated from the inferior vena cava were significantly decreased in the group with L-arg in microsphere after 24 h. No significant differences in prothrombin time, activated partial thromboplastin time, thrombin time, and fibrinogen among the groups were indicated. Images revealed that apoptosis in the vascular wall was less in the group injected with targeted microspheres with L-arg than in the other two groups at 1 and 8 d postsurgery. Meanwhile, cell proliferation was considerably excessive in the group injected with L-arg wrapped in targeted microspheres. Therefore, these novel microspheres could decrease the formation of thrombus in the early stages and in the subsequent periods of thrombosis. The microspheres can also enhance the vitality of impaired endothelial cells and reduce cell apoptosis.

Laser power sources and laser technology for accelerators

International Nuclear Information System (INIS)

Lowenthal, D.

1986-01-01

The requirements on laser power sources for advanced accelerator concepts are formidable. These requirements are driven by the need to deliver 5 TeV particles at luminosities of 10/sup 33/ - 10/sup 34/ cm/sup -2/ sec/sup -1/. Given that optical power can be transferred efficiently to the particles these accelerator parameters translate into single pulse laser output energies of several kilojoules and rep rates of 1-10 kHz. The average laser output power is then 10-20 MW. Larger average powers will be needed if efficient transfer proves not to be possible. A laser plant of this magnitude underscores the importance of high wall plug efficiency and reasonable cost in $/Watt. The interface between the laser output pulse format and the accelerator structure is another area that drives the laser requirements. Laser accelerators break up into two general architectures depending on the strength of the laser coupling. For strong coupling mechanisms, the architecture requires many ''small'' lasers powering the accelerator in a staged arrangement. For the weak coupling mechanisms, the architecture must feature a single large laser system whose power must be transported along the entire accelerator length. Both of these arrangements have demanding optical constraints in terms of phase matching sequential stages, beam combining arrays of laser outputs and optimizing coupling of laser power in a single accelerating stage

PONDEROMOTIVE ACCELERATION IN CORONAL LOOPS

International Nuclear Information System (INIS)

Dahlburg, R. B.; Obenschain, K.; Laming, J. M.; Taylor, B. D.

2016-01-01

Ponderomotive acceleration has been asserted to be a cause of the first ionization potential (FIP) effect, the well-known enhancement in abundance by a factor of 3–4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a “by-product” of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of coronal loops with an axial magnetic field from 0.005 to 0.02 T and lengths from 25,000 to 75,000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets, which act to heat the loop. As a consequence of coronal magnetic reconnection, small-scale, high-speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

PONDEROMOTIVE ACCELERATION IN CORONAL LOOPS

Energy Technology Data Exchange (ETDEWEB)

Dahlburg, R. B.; Obenschain, K. [LCP and FD, Naval Research Laboratory, Washington, DC 20375 (United States); Laming, J. M. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Taylor, B. D. [AFRL Eglin AFB, Pensacola, FL 32542 (United States)

2016-11-10

Ponderomotive acceleration has been asserted to be a cause of the first ionization potential (FIP) effect, the well-known enhancement in abundance by a factor of 3–4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a “by-product” of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of coronal loops with an axial magnetic field from 0.005 to 0.02 T and lengths from 25,000 to 75,000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets, which act to heat the loop. As a consequence of coronal magnetic reconnection, small-scale, high-speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

Selective inhibition by a synthetic hirudin peptide of fibrin-dependent thrombosis in baboons

International Nuclear Information System (INIS)

Cadroy, Y.; Hanson, S.R.; Harker, L.A.; Maraganore, J.M.

1991-01-01

To determine the importance of the thrombin substrate recognition exosite for fibrinogen binding in the formation of both arterial and venous thrombi the authors evaluated the antithrombotic effects of the tyrosine-sulfated dodecapeptide from residues 53-64 of hirudin (H peptide) in a nonhuman primate model. This peptide was studied because it inhibits thrombin cleavages of fibrinogen by simple competition without blocking enzyme catalytic-site function. When an exteriorized arteriovenous access shunt model was used in baboons (Papio anubis), thrombus formation was induced by placing a thrombogenic device made of (i) a segment of tubing coated covalently with type I collagen, which generated platelet-rich thrombi under arterial flow conditions, and (ii) two subsequent annular regions of flow expansion that produced fibrin-rich thrombi typically associated with venous valves and veins. Thrombus formation was quantified by measurements of 111 In-labeled platelet and 125 I-labeled fibrinogen deposition in both arterial-flow and venous-flow portions of the device. These finding suggest that, by competitive inhibition of fibrinogen binding to thrombin, fibrin-rich venous-type thrombus formation may be selectively prevented. This strategy may be therapeutically attractive for preserving normal platelet function when conventional anticoagulant therapy is contraindicated

The kunitz protease inhibitor domain of protease nexin-2 inhibits factor XIa and murine carotid artery and middle cerebral artery thrombosis

Science.gov (United States)

Wu, Wenman; Li, Hongbo; Navaneetham, Duraiswamy; Reichenbach, Zachary W.; Tuma, Ronald F.

2012-01-01

Coagulation factor XI (FXI) plays an important part in both venous and arterial thrombosis, rendering FXIa a potential target for the development of antithrombotic therapy. The kunitz protease inhibitor (KPI) domain of protease nexin-2 (PN2) is a potent, highly specific inhibitor of FXIa, suggesting its possible role in the inhibition of FXI-dependent thrombosis in vivo. Therefore, we examined the effect of PN2KPI on thrombosis in the murine carotid artery and the middle cerebral artery. Intravenous administration of PN2KPI prolonged the clotting time of both human and murine plasma, and PN2KPI inhibited FXIa activity in both human and murine plasma in vitro. The intravenous administration of PN2KPI into WT mice dramatically decreased the progress of FeCl3-induced thrombus formation in the carotid artery. After a similar initial rate of thrombus formation with and without PN2KPI treatment, the propagation of thrombus formation after 10 minutes and the amount of thrombus formed were significantly decreased in mice treated with PN2KPI injection compared with untreated mice. In the middle cerebral artery occlusion model, the volume and fraction of ischemic brain tissue were significantly decreased in PN2KPI-treated compared with untreated mice. Thus, inhibition of FXIa by PN2KPI is a promising approach to antithrombotic therapy. PMID:22674803

Isolation of a substance activating foot formation in hydra

DEFF Research Database (Denmark)

Grimmelikhuijzen, C J; Schaller, H C

1977-01-01

-forming potential of the tissue (2) It does not accelerate head regeneration, nor do the head factors of hydra discovered by Schaller (1973) and Berking (1977) accelerate foot regeneration. We propose that the foot-activating substance is a morphogen responsible for foot formation in hydra. The foot activator can...

Thioredoxin Inhibitors Attenuate Platelet Function and Thrombus Formation.

Science.gov (United States)

Metcalfe, Clive; Ramasubramoni, Anjana; Pula, Giordano; Harper, Matthew T; Mundell, Stuart J; Coxon, Carmen H

2016-01-01

Thioredoxin (Trx) is an oxidoreductase with important physiological function. Imbalances in the NADPH/thioredoxin reductase/thioredoxin system are associated with a number of pathologies, particularly cancer, and a number of clinical trials for thioredoxin and thioredoxin reductase inhibitors have been carried out or are underway. Due to the emerging role and importance of oxidoreductases for haemostasis and the current interest in developing inhibitors for clinical use, we thought it pertinent to assess whether inhibition of the NADPH/thioredoxin reductase/thioredoxin system affects platelet function and thrombosis. We used small molecule inhibitors of Trx (PMX 464 and PX-12) to determine whether Trx activity influences platelet function, as well as an unbiased proteomics approach to identify potential Trx substrates on the surface of platelets that might contribute to platelet reactivity and function. Using LC-MS/MS we found that PMX 464 and PX-12 affected the oxidation state of thiols in a number of cell surface proteins. Key surface receptors for platelet adhesion and activation were affected, including the collagen receptor GPVI and the von Willebrand factor receptor, GPIb. To experimentally validate these findings we assessed platelet function in the presence of PMX 464, PX-12, and rutin (a selective inhibitor of the related protein disulphide isomerase). In agreement with the proteomics data, small molecule inhibitors of thioredoxin selectively inhibited GPVI-mediated platelet activation, and attenuated ristocetin-induced GPIb-vWF-mediated platelet agglutination, thus validating the findings of the proteomics study. These data reveal a novel role for thioredoxin in regulating platelet reactivity via proteins required for early platelet responses at sites of vessel injury (GPVI and GPIb). This work also highlights a potential opportunity for repurposing of PMX 464 and PX-12 as antiplatelet agents.

Thioredoxin Inhibitors Attenuate Platelet Function and Thrombus Formation.

Directory of Open Access Journals (Sweden)

Clive Metcalfe

Full Text Available Thioredoxin (Trx is an oxidoreductase with important physiological function. Imbalances in the NADPH/thioredoxin reductase/thioredoxin system are associated with a number of pathologies, particularly cancer, and a number of clinical trials for thioredoxin and thioredoxin reductase inhibitors have been carried out or are underway. Due to the emerging role and importance of oxidoreductases for haemostasis and the current interest in developing inhibitors for clinical use, we thought it pertinent to assess whether inhibition of the NADPH/thioredoxin reductase/thioredoxin system affects platelet function and thrombosis. We used small molecule inhibitors of Trx (PMX 464 and PX-12 to determine whether Trx activity influences platelet function, as well as an unbiased proteomics approach to identify potential Trx substrates on the surface of platelets that might contribute to platelet reactivity and function. Using LC-MS/MS we found that PMX 464 and PX-12 affected the oxidation state of thiols in a number of cell surface proteins. Key surface receptors for platelet adhesion and activation were affected, including the collagen receptor GPVI and the von Willebrand factor receptor, GPIb. To experimentally validate these findings we assessed platelet function in the presence of PMX 464, PX-12, and rutin (a selective inhibitor of the related protein disulphide isomerase. In agreement with the proteomics data, small molecule inhibitors of thioredoxin selectively inhibited GPVI-mediated platelet activation, and attenuated ristocetin-induced GPIb-vWF-mediated platelet agglutination, thus validating the findings of the proteomics study. These data reveal a novel role for thioredoxin in regulating platelet reactivity via proteins required for early platelet responses at sites of vessel injury (GPVI and GPIb. This work also highlights a potential opportunity for repurposing of PMX 464 and PX-12 as antiplatelet agents.

The Auroral Field-aligned Acceleration - Cluster Results

Science.gov (United States)

Vaivads, A.; Cluster Auroral Team

The four Cluster satellites cross the auroral field lines at altitudes well above most of acceleration region. Thus, the orbit is appropriate for studies of the generator side of this region. We consider the energy transport towards the acceleration region and different mechanisms for generating the potential drop. Using data from Cluster we can also for the first time study the dynamics of the generator on a minute scale. We present data from a few auroral field crossings where Cluster are in conjunction with DMSP satellites. We use electric and magnetic field data to estimate electrostatic po- tential along the satellite orbit, Poynting flux as well as the presence of plasma waves. These we can compare with data from particle and wave instruments on Cluster and on low latitude satellites to try to make a consistent picture of the acceleration region formation in these cases. Preliminary results show close agreement both between in- tegrated potential values at Cluster and electron peak energies at DMSP as well as close agreement between the integrated Poynting flux values at Cluster and the elec- tron energy flux at DMSP. At the end we draw a parallels between auroral electron acceleration and electron acceleration at the magnetopause.

Contributions to the 1999 particle accelerator conference

Energy Technology Data Exchange (ETDEWEB)

Bernard, M. [Laboratoire de l' Accelerateur Lineaire, 91 - Orsay (France); Fartoukh, S.; Jablonka, M.; Joly, J.M.; Lalot, M.; Magne, C.; Napoly, O. [CEA/Saclay, 91 - Gif sur Yvette (France); Baboi, N.; Schreiber, S.; Simrock, S.; Weise, H. [DESY, Hamburg (Germany)

2000-06-01

This document puts together the 10 contributions of the laboratory to the 1999 particle accelerator conference. The titles of the papers are: 1) Evidence for a strongly coupled dipole mode with insufficient damping in the first accelerating module of the TESLA test facility (TTF); 2) An alternative scheme for stiffening superconducting RF cavities by plasma spraying; 3) A laser triggered electron source for pulsed radiolysis; 4) A cure for the energy spread increasing related bunch lengthening in electron storage rings; 5) Single bunch longitudinal instabilities in proton storage rings; 6) Analytical investigation on the halo formation in space charge dominated beams; 7) Analytical investigation on the dynamic apertures of circular accelerators; 8) The intrinsic upper limit to the beam energy of an electron-positron circular collider; 9) Coaxial disc windows for a high power superconducting cavity input coupler; and 10) RF pulsed tests on 3 GHz niobium cavities.

Contributions to the 1999 particle accelerator conference

International Nuclear Information System (INIS)

Bernard, M.; Fartoukh, S.; Jablonka, M.; Joly, J.M.; Lalot, M.; Magne, C.; Napoly, O.; Baboi, N.; Schreiber, S.; Simrock, S.; Weise, H.

2000-06-01

This document puts together the 10 contributions of the laboratory to the 1999 particle accelerator conference. The titles of the papers are: 1) Evidence for a strongly coupled dipole mode with insufficient damping in the first accelerating module of the TESLA test facility (TTF); 2) An alternative scheme for stiffening superconducting RF cavities by plasma spraying; 3) A laser triggered electron source for pulsed radiolysis; 4) A cure for the energy spread increasing related bunch lengthening in electron storage rings; 5) Single bunch longitudinal instabilities in proton storage rings; 6) Analytical investigation on the halo formation in space charge dominated beams; 7) Analytical investigation on the dynamic apertures of circular accelerators; 8) The intrinsic upper limit to the beam energy of an electron-positron circular collider; 9) Coaxial disc windows for a high power superconducting cavity input coupler; and 10) RF pulsed tests on 3 GHz niobium cavities

Rf system specifications for a linear accelerator

International Nuclear Information System (INIS)

Young, A.; Eaton, L.E.

1992-01-01

A linear accelerator contains many systems; however, the most complex and costly is the RF system. The goal of an RF system is usually simply stated as maintaining the phase and amplitude of the RF signal within a given tolerance to accelerate the charged particle beam. An RF system that drives a linear accelerator needs a complete system specification, which should contain specifications for all the subsystems (i.e., high-power RF, low-level RF, RF generation/distribution, and automation control). This paper defines a format for the specifications of these subsystems and discusses each RF subsystem independently to provide a comprehensive understanding of the function of each subsystem. This paper concludes with an example of a specification spreadsheet allowing one to input the specifications of a subsystem. Thus, some fundamental parameters (i.e., the cost and size) of the RF system can be determined

A case of dilated cardiomyopathy with massive left ventricular thrombus after use of a sibutramine-containing slimming product.

Science.gov (United States)

Heo, Seung Hye; Kang, Min-Ho

2013-09-01

Sibutramine, which acts as an anti-obesity drug by inhibiting reuptake of serotonin and norepinephrine, has now been banned due to cardiovascular adverse effects. However, despite being banned, it is not uncommon for people to purchase products with sibutramine or its analogues used as adulterants in non-prescription slimming products or health foods available on the internet. Sibutramine has been associated with rare but serious adverse reactions such as cardiac arrhythmia including QT interval prolongation, myocardial infarction, and cardiomyopathy, as well as increases in blood pressure and pulse rate. Here, we report a case of a 32-year-old male who presented with dilated cardiomyopathy with massive left ventricular thrombus after taking unauthorized sibutramine-containing slimming pills sold over the internet.

Acceleration waves in non-ideal magnetogasdynamics

Directory of Open Access Journals (Sweden)

R. Singh

2014-03-01

Full Text Available The problem of propagation of acceleration waves in an unsteady inviscid non-ideal gas under the influence of magnetic field is investigated. The characteristic solution to the problem in the neighbourhood of leading characteristics has been determined. An evolution equation governing the behaviour of acceleration waves has been derived. It is shown that a linear solution in the characteristic plane exhibits non-linear behaviour in physical plane. The effect of magnetic field on the formation of shock in non-ideal gas flow with planar and cylindrical symmetry is analysed. It is noticed that all compressive waves terminate into a shock wave. Further, we also compare/contrast the nature of solution in ideal and non-ideal magnetogasdynamic regime.

Fate of the dissecting lumen by CT study following surgical repair

Energy Technology Data Exchange (ETDEWEB)

Nakajima, Nobuyuki; Ando, Taizo; Kawazoe, Kohei; Tomino, Tetsuo; Fujita, Takeshi; Naito, Hiroaki; Yamaguchi, Toshio

1983-03-01

A postoperative follow-up study on the fate of dissecting lumen by means of computer tomography has been evaluated. The materials were 21 patients who underwent surgery for dissection of the aorta, including 8 patients in type 1 of DeBakey classification, 3 in type 11, 8 in type 111 and 2 patients of localized dissection in descending and abdominal aorta. The susceptibility for thrombus formation in dissecting lumen appeared to be related to the background etiology of dissection where poor tendency for thrombus formation was observed in a group of patients with Marfan syndrome and its' incomplete form. On the other hand in the group of patients who had a history of hypertension and atherosclerosis probable, a strong tendency of thrombus formation and eventual occlusion of lumen was obtained. On the basis of above findings, it will be said that the surgical intervention for type 1 of DeBakey classification in Marfan patient is merely creating type 111 dissection, closed observation in the future change of dissecting lumen is of utmost importance especially in those groups of patients.

Fate of the dissecting lumen by CT study following surgical repair

International Nuclear Information System (INIS)

Nakajima, Nobuyuki; Ando, Taizo; Kawazoe, Kohei; Tomino, Tetsuo; Fujita, Takeshi; Naito, Hiroaki; Yamaguchi, Toshio.

1983-01-01

A postoperative follow-up study on the fate of dissecting lumen by mean of computer tomography has been evaluated. The materials were 21 patients who underwent surgery for dissection of the aorta, including 8 patients in type 1 of DeBakey classification, 3 in type 11, 8 in type 111 and 2 patients of localized dissection in descending and abdominal aorta. The susceptibility for thrombus formation in dissecting lumen appeared to be relating to the background etiology of dissection where poor tendency for thrombus formation was observed in group of patients with Marfan syndrome and its' incomplete form. On the other hand in those group of patients who had a history of hypertension and atherosclerosis probable, a strong tendency of thrombus formation and eventual occlusion of lumen was obtained. On the basis of above findings, it will be said that the surgical intervention for type 1 of DeBakey classification in Marfan patient is merely creating type 111 dissection, closed observation in the future change of dissecting lumen is utmost important especially in those group of patients. (author)

Beam losses and beam halos in accelerators for new energy sources

International Nuclear Information System (INIS)

Jameson, R.A.

1995-01-01

Large particle accelerators are proposed as drivers for new ways to produce electricity from nuclear fusion and fission reactions. The accelerators must be designed to deliver large particle beam currents to a target facility with very little beam spill along the accelerator itself, in order that accelerator maintenance can be accomplished without remote manipulators. Typically, particle loss is preceded by the formation of a tenuous halo of particles around the central beam core, caused by beam dynamics effects, often coupled with the slight imperfections inevitable in a practical design. If the halo becomes large enough, particles may be scraped off along the accelerator. The tolerance for beam spill in different applications is discussed, halo mechanisms and recent work to explore and understand their dynamics are reviewed, and possible directions for future investigation are outlined. 17 refs., 10 figs

Transarterial chemoembolization combined with sorafenib for the treatment of hepatocellular carcinoma with hepatic vein tumor thrombus

Directory of Open Access Journals (Sweden)

Zhang YF

2016-07-01

Full Text Available Yong-Fa Zhang,1–3,* Wei Wei,1–3,* Jia-Hong Wang,1–3,* Li Xu,1–3 Pei-En Jian,1–3 Cheng-Zuo Xiao,4 Xiao-Ping Zhong,1–3 Ming Shi,1–3 Rong-Ping Guo1–3 1Department of Hepatobiliary Oncology, Sun Yat-sen University Cancer Center, 2State Key Laboratory of Oncology in South China, 3Collaborative Innovation Center for Cancer Medicine, Guangzhou, 4Department of General Surgery, Shenzhen Shajing Affiliated Hospital of Guangzhou Medical University, Shenzhen, People’s Republic of China *These authors contributed equally to this work Objective: To compare the treatment outcomes of sorafenib plus transarterial chemoembolization (TACE vs TACE alone in patients with hepatocellular carcinoma (HCC and hepatic vein tumor thrombus (HVTT.Methods: Twenty patients who were initially diagnosed with HCC and HVTT and received TACE combined with sorafenib during February 2009 to October 2013 were included in the study. To minimize selection bias, these patients were compared with 60 case-matched controls selected from a pool of 81 patients (in a 1:3 ratio who received TACE alone during the same period. The primary end point was overall survival (OS. The secondary end points were time to progression, disease control rate, and adverse events.Results: After a median follow-up period of 12.5 months (range, 1.03–44.23 months, the OS of the combined group was found to be significantly higher compared with the monotherapy group (14.9 vs 6.1 months, P=0.010. The time to progression was found to be significantly longer in the combined group (4.9 vs 2.4 months, P=0.016. Univariate and multivariate analyses revealed that the treatment allocation was an independent predictor of OS.Conclusion: Sorafenib plus TACE was well tolerated and was more effective in treating patients with advanced HCC and HVTT. Future trials with prospective larger samples are required to validate these results. Keywords: hepatocellular carcinoma, hepatic vein tumor thrombus, prognosis

The role of platelet and endothelial GARP in thrombosis and hemostasis.

Science.gov (United States)

Vermeersch, Elien; Denorme, Frederik; Maes, Wim; De Meyer, Simon F; Vanhoorelbeke, Karen; Edwards, Justin; Shevach, Ethan M; Unutmaz, Derya; Fujii, Hodaka; Deckmyn, Hans; Tersteeg, Claudia

2017-01-01

Glycoprotein-A Repetitions Predominant protein (GARP or LRRC32) is present on among others human platelets and endothelial cells. Evidence for its involvement in thrombus formation was suggested by full knockout of GARP in zebrafish. To evaluate the role of GARP in platelet physiology and in thrombus formation using platelet and endothelial conditional GARP knock out mice. Platelet and endothelial specific GARP knockout mice were generated using the Cre-loxP recombination system. The function of platelets without GARP was measured by flow cytometry, spreading analysis and aggregometry using PAR4-activating peptide and collagen related peptide. Additionally, clot retraction and collagen-induced platelet adhesion and aggregation under flow were analyzed. Finally, in vivo tail bleeding time, occlusion time of the mesenteric and carotid artery after FeCl3-induced thrombosis were determined in platelet and endothelial specific GARP knock out mice. Platelet specific GARP knockout mice had normal surface GPIb, GPVI and integrin αIIb glycoprotein expression. Although GARP expression was increased upon platelet activation, platelets without GARP displayed normal agonist induced activation, spreading on fibrinogen and aggregation responses. Furthermore, absence of GARP on platelets did not influence clot retraction and had no impact on thrombus formation on collagen-coated surfaces under flow. In line with this, neither the tail bleeding time nor the occlusion time in the carotid- and mesenteric artery after FeCl3-induced thrombus formation in platelet or endothelial specific GARP knock out mice were affected. Evidence is provided that platelet and endothelial GARP are not important in hemostasis and thrombosis in mice.

The role of platelet and endothelial GARP in thrombosis and hemostasis.

Directory of Open Access Journals (Sweden)

Elien Vermeersch

Full Text Available Glycoprotein-A Repetitions Predominant protein (GARP or LRRC32 is present on among others human platelets and endothelial cells. Evidence for its involvement in thrombus formation was suggested by full knockout of GARP in zebrafish.To evaluate the role of GARP in platelet physiology and in thrombus formation using platelet and endothelial conditional GARP knock out mice.Platelet and endothelial specific GARP knockout mice were generated using the Cre-loxP recombination system. The function of platelets without GARP was measured by flow cytometry, spreading analysis and aggregometry using PAR4-activating peptide and collagen related peptide. Additionally, clot retraction and collagen-induced platelet adhesion and aggregation under flow were analyzed. Finally, in vivo tail bleeding time, occlusion time of the mesenteric and carotid artery after FeCl3-induced thrombosis were determined in platelet and endothelial specific GARP knock out mice.Platelet specific GARP knockout mice had normal surface GPIb, GPVI and integrin αIIb glycoprotein expression. Although GARP expression was increased upon platelet activation, platelets without GARP displayed normal agonist induced activation, spreading on fibrinogen and aggregation responses. Furthermore, absence of GARP on platelets did not influence clot retraction and had no impact on thrombus formation on collagen-coated surfaces under flow. In line with this, neither the tail bleeding time nor the occlusion time in the carotid- and mesenteric artery after FeCl3-induced thrombus formation in platelet or endothelial specific GARP knock out mice were affected.Evidence is provided that platelet and endothelial GARP are not important in hemostasis and thrombosis in mice.

Mechanical valve obstruction: Review of diagnostic and treatment strategies

Science.gov (United States)

Salamon, Jason; Munoz-Mendoza, Jerson; Liebelt, Jared J; Taub, Cynthia C

2015-01-01

Prosthetic valve obstruction (PVO) is a rare but feared complication of mechanical valve replacement. Diagnostic evaluation should focus on differentiating prosthetic valve thrombosis (PVT) from pannus formation, as their treatment options differ. History of sub-optimal anti-coagulation and post-op time course to development of PVO are useful clinical characteristics in differentiating thrombus from pannus formation. Treatment of PVT is influenced by the patient’s symptoms, valve location, degree of obstruction and thrombus size and may include thrombolysis or surgical intervention. Alternatively, pannus formation requires surgical intervention. The purpose of this article is to review the pathophysiology, epidemiology, diagnostic approach and treatment options for aortic and mitral valve PVO. PMID:26730292

Reproduction of a new inferior vena cava thrombosis model and study of the evolutionary process of thrombolysis in rats

Directory of Open Access Journals (Sweden)

Jian FU

2015-10-01

Full Text Available Objective　To investigate the reproduction of a new model of thrombosis of inferior vena cava (IVC, and explore the natural process of thrombolysis and its mechanism in rats. Methods　Forty-eight SD rats were randomly classified into experimental group and control group. In the experimental group, the lumen of the vena cava was blocked by about 80%-90% with a ligature of IVC below the left renal vein, and then the animals were redivided into three subgroups (n=12, each. In group A, the IVC endothelium was damaged and its tributaries were ligated. In group B, the IVC endothelium was damaged and its tributaries were not ligated. In group C, no damage was done to the endothelium of the IVC but all its tributaries were ligated. A sham-operated group served as control. The length and weight of the vinous thrombus and the percentage of the IVC luminal area were compared after operation to determine the optimum animal model of venous thrombosis. According to the best mode to establish the model, the thrombus specimens were collected and detected by HE and Masson staining, and the ED-1 expressions were examined by immunohistochemical staining after thrombus formation in 30 rats. The natural evolution of intravenous thrombolysis was analyzed dynamically and the cell types involved in this process were observed. Results　Gross observation showed that the experimental group was successfully induced thrombus formation. The thrombus length and weight in group A was significantly higher than that in group B and group C, and no difference between group B and C. The thrombus area in group A was significantly higher than that in groups B and group C, which identified the group A was the optimal model group of venous thrombosis. In the group reproduced by the best mode of the model, HE and Masson staining results showed that new capillaries and the components of collagen and extracellular matrix increased gradually with the passage of time in the process of

Numerical modeling of the plasma ring acceleration experiment

International Nuclear Information System (INIS)

Eddleman, J.L.; Hammer, J.H.; Hartman, C.W.

1987-01-01

Modeling of the LLNL RACE experiment and its many applications has necessitated the development and use of a wide array of computational tools. The two-dimensional MHD code, HAM, has been used to model the formation of a compact torus plasma ring in a magnetized coaxial gun and its subsequent acceleration by an additional applied toroidal field. Features included in the 2-D calculations are self-consistent models for (1) the time-dependent poloidal field produced by a capacitor bank discharge through a solenoid field coil (located either inside the gun inner electrode or outside the outer gun electrode) and the associated diffusion of magnetic flux through neighboring conductors, (2) gas flow into the gun annular region from a simulated puffed gas valve plenum, (3) formation and motion of a current sheet produced by J x B forces resulting from discharge of the gun capacitor bank through the plasma load between the coaxial gun electrodes, (4) the subsequent stretching and reconnection of the poloidal field lines to form a compact torus plasma ring, and (5) finally the discharge of the accelerator capacitor bank producing an additional toroidal field for acceleration of the plasma ring. The code has been extended to include various models for gas breakdown, plasma anomalous resistivity, and mass entrainment from ablation of electrode material

Laser and Particle Guiding Micro-Elements for Particle Accelerators

CERN Document Server

Plettner, Tomas; Spencer, James; Wisdom, Jeffrey

2005-01-01

Laser driven particle accelerators based on the current generation of lasers will require sub-micron control of the laser field as well as precise beam guiding. Hence the fabrication techniques that allow integrating both elements into an accelerator-on-chip format become critical for the success of such particle accelerators. Micromachining technology for silicon has been shown to be one such feasible technology in PAC2003 but with a variety of complications on the laser side. Fortunately, in recent years the fabrication of transparent ceramics has become an interesting technology that could be applied for laser-particle accelerators in several ways. We discuss this area, its advantages such as the range of materials it provides and various ways to implement it followed by some different test examples that have been considered. One important goal of this approach is an integrated system that could avoid the necessity of having to inject either laser or particle pulses into these structures.

Accelerated Near-Threshold Fatigue Crack Growth Behavior of an Aluminum Powder Metallurgy Alloy

Science.gov (United States)

Piascik, Robert S.; Newman, John A.

2002-01-01

Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low DK, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels of Kmax (Kmax less than 0.4 KIC). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and Kmax influenced accelerated crack growth is time and temperature dependent.

Orbit selection of nanosatellite formation in term of fuel consumption

Science.gov (United States)

Pimnoo, Ammarin; Hiraki, Koju

In nanosatellite formation mission design, orbit selection is a necessary factor. Fuel consumption is also necessary to maintain the orbit. Therefore, the best orbit should be the one of minimum fuel consumption for nanosatellite formation. The purpose of this paper is to provide a convenient way to estimate fuel consumption for a nanosatellite to keep formation flying. The formation is disturbed by J _{2} perturbation and other perturbing accelerations. Firstly, the Hill-Clohessy-Wiltshire equations are used in the analysis. Gaussian variation of parameters is included into the Hill’s equation to analyze the variation of Kaplerian orbital elements. The J _{2} perturbation and other perturbing accelerations such as atmospheric drag, solar-radiation pressure and third-body perturbations are considered. Thus, a linear model based on Hill’s equation is established to estimate fuel consumption. Finally, an example of the best orbit for formation flying with minimum fuel consumption shall be presented.

Greece welcomes CERN Accelerator School

CERN Multimedia

CAS School

2011-01-01

The CERN Accelerator School (CAS) and the University of the Aegean jointly organised a course on intermediate-level Accelerator Physics in Chios, Greece, from 19 to 30 September, 2011.   CAS Students pose for a group photo in Chios, Greece. This course followed the established format of the intermediate school, with lectures in the mornings and specialised courses in the afternoons. The latter provided “hands-on” education and experience in three topics: “RF Measurement Techniques”, “Beam Instrumentation and Diagnostics” and “Optics Design and Correction”.  Participants selected one of the three courses and followed the chosen topic throughout the school. Guided studies and tutorials on core subjects, seminars and a poster session completed the programme. An excursion included a visit to the Nea Moni monastery, a guided tour of two medieval villages, Pyrgi and Mesta, and finished with a typical Greek me...

Inferior vena cava filter thrombus: A possible cause of an unanticipated finding of {sup 99m} Tc-labeled red blood cell scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Song, Hee Sung; Choi, Joon Hyouk; Kim, Young Suk [Jeju National University School of Medicine, Jeju (Korea, Republic of)

2016-06-15

{sup 99m}Tc-labeled red blood cell scintigraphy, a sensitive and specific diagnostic test, is useful for patients suspected of suffering from active gastrointestinal bleeding. This study follows a case of a patient who was suspected of gastrointestinal bleeding after an inferior vena cava filter was inserted due to a deep vein thrombosis of the femoral vein. To evaluate an exact focus of bleeding, {sup 99m}Tc-labeled red blood cell scintigraphy was executed. Herein, an unanticipated finding of {sup 99m}Tc-labeled red blood cell scintigraphy probably due to a thrombus on the inferior vena cava filter is reported.

Preparation and Performance of a New-Type Alkali-Free Liquid Accelerator for Shotcrete

Directory of Open Access Journals (Sweden)

Yanping Sheng

2017-01-01

Full Text Available A new type of alkali-free liquid accelerator for shotcrete was prepared. Specifically, the setting time and strength and shrinkage performance of two kinds of Portland cement with the accelerator were fully investigated. Moreover, the accelerating mechanism of alkali-free liquid accelerator and the hydration process of the shotcrete with accelerator were explored. Results show that alkali-free liquid accelerator significantly shortened the setting time of cement paste, where the initial setting time of cement paste with 8 wt% of the accelerator was about 3 min and the final setting time was about 7 min. Compressive strength at 1 day of cement mortar with the accelerator could reach 23.4 MPa, which increased by 36.2% compared to the strength of cement mortar without the accelerator, and the retention rate of 28-day compressive strength reached 110%. In addition, the accelerator still shows a good accelerating effect under low temperature conditions. However, the shrinkage rate of the concrete increased with the amount of the accelerator. 5~8% content of accelerator is recommended for shotcrete in practice. XRD and SEM test results showed that the alkali-free liquid accelerator promoted the formation of ettringite crystals due to the increase of Al3+ and SO42- concentration.

Mass-Discrepancy Acceleration Relation: A Natural Outcome of Galaxy Formation in Cold Dark Matter Halos.

Science.gov (United States)

Ludlow, Aaron D; Benítez-Llambay, Alejandro; Schaller, Matthieu; Theuns, Tom; Frenk, Carlos S; Bower, Richard; Schaye, Joop; Crain, Robert A; Navarro, Julio F; Fattahi, Azadeh; Oman, Kyle A

2017-04-21

We analyze the total and baryonic acceleration profiles of a set of well-resolved galaxies identified in the eagle suite of hydrodynamic simulations. Our runs start from the same initial conditions but adopt different prescriptions for unresolved stellar and active galactic nuclei feedback, resulting in diverse populations of galaxies by the present day. Some of them reproduce observed galaxy scaling relations, while others do not. However, regardless of the feedback implementation, all of our galaxies follow closely a simple relationship between the total and baryonic acceleration profiles, consistent with recent observations of rotationally supported galaxies. The relation has small scatter: Different feedback implementations-which produce different galaxy populations-mainly shift galaxies along the relation rather than perpendicular to it. Furthermore, galaxies exhibit a characteristic acceleration g_{†}, above which baryons dominate the mass budget, as observed. These observations, consistent with simple modified Newtonian dynamics, can be accommodated within the standard cold dark matter paradigm.

Gravitomagnetic Acceleration of Black Hole Accretion Disk Matter to Polar Jets

Science.gov (United States)

Poirier, John; Mathews, Grant

2015-04-01

It is shown that the motion of the neutral masses in an accretion disk orbiting a black hole creates a magnetic-like (gravitomagnetic) field that vertically accelerates neutral particles near the accretion disk away from the disk and then inward toward the axis of the accretion disk. Moreover, as the accelerated material nears the axis, a frame-dragging effect twists the trajectories around the axis thus contributing to the formation of a narrow polar jet emanating from the poles.

Antiplatelet Activity of Morus alba Leaves Extract, Mediated via Inhibiting Granule Secretion and Blocking the Phosphorylation of Extracellular-Signal-Regulated Kinase and Akt

Science.gov (United States)

Rhee, Man Hee; Sung, Yoon-Young; Yang, Won-Kyung; Kim, Seung Hyung; Kim, Ho-Kyoung

2014-01-01

Ethnopharmacological Relevance. Morus alba L. leaves (MAE) have been used in fork medicine for the treatment of beriberi, edema, diabetes, hypertension, and atherosclerosis. However, underlying mechanism of MAE on cardiovascular protection remains to be elucidated. Therefore, we investigated whether MAE affect platelet aggregation and thrombosis. Materials and Methods. The anti-platelet activity of MAE was studied using rat platelets. The extent of anti-platelet activity of MAE was assayed in collagen-induced platelet aggregation. ATP and serotonin release was carried out. The activation of integrin α IIb β 3 and phosphorylation of signaling molecules, including MAPK and Akt, were investigated with cytofluorometer and immunoblotting, respectively. The thrombus formation in vivo was also evaluated in arteriovenous shunt model of rats. Results. HPLC chromatographic analysis revealed that MAE contained rutin and isoquercetin. MAE dose-dependently inhibited collagen-induced platelet aggregation. MAE also attenuated serotonin secretion and thromboxane A2 formation. In addition, the extract in vivo activity showed that MAE at 100, 200, and 400 mg/kg significantly and dose-dependently attenuated thrombus formation in rat arterio-venous shunt model by 52.3% (P < 0.001), 28.3% (P < 0.01), and 19.1% (P < 0.05), respectively. Conclusions. MAE inhibit platelet activation, TXB2 formation, serotonin secretion, aggregation, and thrombus formation. The plant extract could be considered as a candidate to anti-platelet and antithrombotic agent. PMID:24701244

The predisposing effect of TGF-β1 and serpine-1 on the formation of traumatic deep vein thrombosis: an experimental study in rats

International Nuclear Information System (INIS)

Hu Jihong; Wu Xuemei; Li Xingguo; Li Hongkun; Zheng Hongyu; Zhao Xueling; Wang Bing

2011-01-01

Objective: To investigate the changes of TGF-β1 and serpine-1 expression in femoral vein endothelial tissue in the experimental rat models with traumatic deep vein thrombosis (DVT) and to study the effect of expression level on the formation of traumatic deep vein thrombosis. Methods: A total of 60 SD rats were randomly divided into control group (n=10) and experimental group (n=50). Rat model of DVT used in experimental group was established by clamping the femoral vein together with the fixation of the lower extremity with plaster splint. The femoral arteries were dissected at 2.5 and 25 hours after trauma to observe the occurrence of thrombus and its severity. Based on the degree of thrombus formation, the rats in the experimental group was divided into group B (pre-thrombogenesis, 2.5 hours after trauma), group C (thrombogenesis, 25 hours after trauma) and group D (non-thrombogenesis, 25 hours after trauma). Then total RNA was extracted from the local femoral venous tissue. The different expressed genes were screened by adopting a special chip, Rat Genome 2302.0 These gene expressions were further identified by real-time PCR. In addition, these genes were further analyzed by using Pathway technique and other biological information analysis. Results: The results of both gene chip hybridization analysis and real-time PCR showed that the mRNA expressions of both TGF-β1 and serpine-1 in rat femoral vein endothelial tissue were significantly up-regulated at 2.5 hours after trauma, in addition, the expressions of group B were significantly higher than those of group A and group D (P 0.05). Pathway analysis showed that TGF-β1 was the epistatic regulatory gene of serpine-1, as it could induce the over-expression of serpine-1, inhibit fibrinolysis and promote thrombosis. Conclusion: The results obtained from the present study indicate that the up-regulated TGF-β1 and serpine-1 in local femoral venous endothelial tissue may play a crucial role in the formation of

A quasimechanism of melt acceleration in the thermal decomposition of crystalline organic solids

Energy Technology Data Exchange (ETDEWEB)

Henson, Bryan F [Los Alamos National Laboratory

2009-01-01

It has been know for half a century that many crystalline organic solids undergo an acceleration in the rate of thermal decomposition as the melting temperature is approached. This acceleration terminates at the melting point, exhibiting an Arrhenius-like temperature dependence in the faster decomposition rate from the liquid phase. This observation has been modeled previously using various premelting behaviors based on e.g. freezing point depression induced by decomposition products or solvent impurities. These models do not, however, indicate a mechanism for liquid formation and acceleration which is an inherent function of the bulk thermodynamics of the molecule. Here we show that such an inherent thermodynamic mechanism for liquid formation exists in the form of the so-called quasi-liquid layer at the solid surface. We explore a kinetic mechanism which describes the acceleration of rate and is a function of the free energies of sublimation and vaporization. We construct a differential rate law from these thermodynamic free energies and a normalized progress variable. We further construct a reduced variable formulation of the model which is a simple function of the metastable liquid activity below the melting point, and show that it is applicable to the observed melt acceleration in several common organic crystalline solids. A component of the differential rate law, zero order in the progress variable, is shown to be proportional to the thickness of the quasiliquid layer predicted by a recent thermodynamic theory for this phenomenon. This work therefore serves not only to provide new insight into thermal decomposition in a broad class or organic crystalline solids, but also further validates the underlying thermodynamic nature of the phenomenon of liquid formation on the molecular surface at temperatures below the melting point.

Self-accelerating universe in Galileon cosmology

International Nuclear Information System (INIS)

Silva, Fabio P.; Koyama, Kazuya

2009-01-01

We present a cosmological model with a solution that self-accelerates at late times without signs of ghost instabilities on small scales. The model is a natural extension of the Brans-Dicke (BD) theory including a nonlinear derivative interaction, which appears in a theory with the Galilean shift symmetry. The existence of the self-accelerating universe requires a negative BD parameter but, thanks to the nonlinear term, small fluctuations around the solution are stable on small scales. General relativity is recovered at early times and on small scales by this nonlinear interaction via the Vainshtein mechanism. At late time, gravity is strongly modified and the background cosmology shows a phantomlike behavior and the growth rate of structure formation is enhanced. Thus this model leaves distinct signatures in cosmological observations and it can be distinguished from standard LCDM cosmology.

The Relationship Between Pulsatile Flow Impingement and Intraluminal Thrombus Deposition in Abdominal Aortic Aneurysms.

Science.gov (United States)

Lozowy, Richard J; Kuhn, David C S; Ducas, Annie A; Boyd, April J

2017-03-01

Direct numerical simulations were performed on four patient-specific abdominal aortic aneurysm (AAA) geometries and the resulting pulsatile blood flow dynamics were compared to aneurysm shape and correlated with intraluminal thrombus (ILT) deposition. For three of the cases, turbulent vortex structures impinged/sheared along the anterior wall and along the posterior wall a zone of recirculating blood formed. Within the impingement region the AAA wall was devoid of ILT and remote to this region there was an accumulation of ILT. The high wall shear stress (WSS) caused by the impact of vortexes is thought to prevent the attachment of ILT. WSS from impingement is comparable to peak-systolic WSS in a normal-sized aorta and therefore may not damage the wall. Expansion occurred to a greater extent in the direction of jet impingement and the wall-normal force from the continuous impact of vortexes may contribute to expansion. It was shown that the impingement region has low oscillatory shear index (OSI) and recirculation zones can have either low or high OSI. No correlation could be identified between OSI and ILT deposition since different flow dynamics can have similar OSI values.

Cerebral Venous Thrombosis and Pulmonary Embolism with Prothrombin G20210A Gene Mutation

OpenAIRE

Dagli, Canan Eren; Koksal, Nurhan; Guler, Selma; Gelen, Mehmet Emin; Atilla, Nurhan; Tuncel, Deniz

2010-01-01

A 25-year-old man presented with symptoms of syncope, cough, headache and hemoptysis. Cranial MR and venography showed thrombus formation in the right transverse sinus and superior sagittal sinus. Computed tomographic pulmonary angiography (CTPA) showed an embolic thrombus in the right pulmonary truncus and lung abscess. The patient was young, and there were no signs of lower extremity deep venous thrombosis or other major risk factors for pulmonary embolism (PE) including cardiac anomaly. Th...

Resuscitation and Transfusion Principles for Traumatic Hemorrhagic Shock

Science.gov (United States)

2009-11-01

with each of these in addition to bacterial contamination, deep venous thromboembolism (DVT), and febrile reactions.101 The risks of these adverse events...by Cannon in 1918 can be summarized as allowing the blood pressure to be slightly less than normal to promote thrombus formation while still providing...a forming thrombus will not be able to achieve hemostasis, and re-bleeding occurs. This has been called “popping the clot”.34 This concept is

Plasma accelerators

International Nuclear Information System (INIS)

Bingham, R.; Angelis, U. de; Johnston, T.W.

1991-01-01

Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate

International Nuclear Information System (INIS)

C.Z. Cheng; Y. Ren; G.S. Choe; Y.-J. Moon

2003-01-01

A physical mechanism of flares, in particular for the flare rise phase, has emerged from our 2-1/2-dimensional resistive MHD simulations. The dynamical evolution of current-sheet formation and magnetic reconnection and flux-rope acceleration subject to continuous, slow increase of magnetic shear in the arcade are studied by employing a non-uniform anomalous resistivity in the reconnecting current sheet under gravity. The simulation results directly relate the flux rope's accelerated rising motion with an enhanced magnetic reconnection rate and thus an enhanced reconnection electric field in the current sheet during the flare rise phase. The simulation results provide good quantitative agreements with observations of the acceleration of flux rope, which manifests in the form of SXR ejecta or erupting filament or CMEs, in the low corona. Moreover, for the X-class flare events studied in this paper the peak reconnection electric field is about O(10 2 V/m) or larger, enough to accelerate p articles to over 100 keV in a field-aligned distance of 10 km. Nonthermal electrons thus generated can produce hard X-rays, consistent with impulsive HXR emission observed during the flare rise phase

Studies of the plasma droplet accelerator scheme

International Nuclear Information System (INIS)

Mori, W.B.; Joshi, C.; Dawson, J.M.; Lee, K.; Forslund, D.W.; Kindel, J.M.

1985-01-01

In the plasma droplet accelerator scheme, proposed by R. Palmer, a sequence of liquid micro-spheres generated by a jet printer are ionized by an incoming intense laser. The hope is that the micro-spheres now acting as conducting balls will allow efficient coupling of the incoming laser radiation into an accelerating mode. Motivated by this the authors have carried out 2D, particle simulations in order to answer some of the plasma physics questions hitherto unaddressed. In particular they find that at least for laser intensities exceeding v 0 /c=0.03 (/sup ∼/10 13 w/cm 2 for a CO 2 laser), the incident laser light is rather efficiently absorbed in a hot electron distribution. Up to 70% of the incident energy can be absorbed by these electrons which rapidly expand and fill the vacuum space between the microspheres with a low density plasma. These results indicate that it is advisable to stay clear of plasma formation and thus put on an upper limit on the maximum surface fields that can be tolerated in the droplet-accelerator scheme

Studies of the plasma droplet accelerator scheme

International Nuclear Information System (INIS)

Mori, W.B.; Dawson, J.M.; Forslund, D.W.; Joshi, C.; Kindel, J.M.; Lee, K.

1985-01-01

In the plasma droplet accelerator scheme, proposed by R. Palmer, a sequence of liquid micro-spheres generated by a jet printer are ionized by an incoming intense laser. The hope is that the micro-spheres now acting as conducting balls will allow efficient coupling of the incoming laser radiation into an accelerating mode. Motivated by this we have carried out 2D, particle simulations in order to answer some of the plasma physics questions hitherto unaddressed. In particular we find that at least for laser intensities exceeding v /SUB o/ /c=0.03 ( about10 13 w/cm 2 for a CO 2 laser), the incident laser light is rather efficiently absorbed in a hot electron distribution. Up to 70% of the incident energy can be absorbed by these electrons which rapidly expand and fill the vacuum space between the microspheres with a low density plasma. These results indicate that it is advisable to stay clear of plasma formation and thus put on an upper limit on the maximum surface fields that can be tolerated in the droplet-accelerator scheme

Giant cavernous carotid aneurysm with spontaneous ipsilateral ICA occlusion: Report of 2 cases and review of literature

Directory of Open Access Journals (Sweden)

Savitr BV Sastri

2013-01-01

Full Text Available Giant aneurysms of the cavernous carotid artery are rare entities which present predominantly with features of compression of the adjacent neural structures, most commonly the III, IV, VI and V cranial nerves. Historically, treatment options included occlusion of the feeding vessel, direct surgery on the aneurysm, bypass procedures and in recent times, the use of endovascular devices. While intramural thrombus formation is commonly seen in giant aneurysms, we present 2 cases of giant cavernous aneurysms which on evaluation were found to have spontaneous occlusion of the feeding internal carotid artery secondary to thrombus formation, and review the available literature regarding the same.

Detection of von Willebrand factor and tissue factor in platelets-fibrin rich coronary thrombi in acute myocardial infarction.

Science.gov (United States)

Yamashita, Atsushi; Sumi, Takahiro; Goto, Shinya; Hoshiba, Yasunari; Nishihira, Kensaku; Kawamoto, Riichirou; Hatakeyama, Kinta; Date, Haruhiko; Imamura, Takuroh; Ogawa, Hisao; Asada, Yujiro

2006-01-01

The rapid closure of coronary arteries due to occlusive thrombi is the major cause of acute myocardial infarction. However, the mechanisms of coronary thrombus formation have not been elucidated. We immunohistochemically assessed the localizations and their changes over time of glycoprotein IIb/IIIa, fibrin, von Willebrand factor (vWF), and tissue factor (TF), after the onset of chest pain (platelets, fibrin, vWF, and TF from the early phase of onset, and glycoprotein IIb/IIIa and fibrin were closely associated with vWF and TF, respectively. vWF and/or TF may contribute to occlusive thrombus formation and be novel therapeutic candidates for treating patients with coronary thrombosis.

Operation of LIA-30 linear induction accelerator in the mode of generation of two bremsstrahlung pulses

Energy Technology Data Exchange (ETDEWEB)

Bossamykin, V S; Gerasimov, A I; Gordeev, V S; Grishin, A V; Gritsina, V P; Tarasov, A D; Fedotkin, A S; Lazarev, S A; Averchenkov, A Ya [All-Russian Scientific Research Institute of Experimental Physics, Sarov (Russian Federation)

1997-12-31

The operating mode was studied of the LIA-30 linear induction accelerator ({approx} 40 MeV, {approx} 100 kA, {approx} 30 ns) with the generation of two bremsstrahlung pulses separated by a specified time interval from 0 to 5 {mu}s. In the accelerating channel an additional tube cathode was installed, and a synchronization system for two accelerating module groups triggering the formation and acceleration, at different initial times, of two annular electron beams with different outer diameters was changed. The energy limit of each beam electron acceleration can be controlled, and the energy sum limit is {<=} 540 MeV. (author). 2 tabs., 2 figs.

A Model of RHIC Using the Unified Accelerator Libraries

Energy Technology Data Exchange (ETDEWEB)

Pilat, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trahern, C. G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Malitsky, N. [Cornell Univ., Ithaca, NY (United States)

1998-01-01

The Unified Accelerator Library (UAL) is an object oriented and modular software environment for accelerator physics which comprises an accelerator object model for the description of the machine (SMF, for Standard Machine Format), a collection of Physics Libraries, and a Perl inte,face that provides a homo­geneous shell for integrating and managing these components. Currently available physics libraries include TEAPOT++, a collection of C++ physics modules conceptually derived from TEAPOT, and DNZLIB, a differential algebra package for map generation. This software environment has been used to build a flat model of RHIC which retains the hierarchical lat­tice description while assigning specific characteristics to individual elements, such as measured field har­monics. A first application of the model and of the simulation capabilities of UAL has been the study of RHIC stability in the presence of siberian snakes and spin rotators. The building blocks of RHIC snakes and rotators are helical dipoles, unconventional devices that can not be modeled by traditional accelerator phys­ics codes and have been implemented in UAL as Taylor maps. Section 2 describes the RHIC data stores, Section 3 the RHIC SMF format and Section 4 the RHIC spe­cific Perl interface (RHIC Shell). Section 5 explains how the RHIC SMF and UAL have been used to study the RHIC dynamic behavior and presents detuning and dynamic aperture results. If the reader is not familiar with the motivation and characteristics of UAL, we include in the Appendix an useful overview paper. An example of a complete set of Perl Scripts for RHIC simulation can also be found in the Appendix.

High-speed hydrogen pellet acceleration using an electromagnetic railgun system

International Nuclear Information System (INIS)

Onozuka, M.; Oda, Y.

1997-01-01

Using a low electric energy railgun system, solid hydrogen pellet acceleration test have been conducted to investigate the application of the electromagnetic railgun system for high-speed pellet injection into fusion plasmas. Pneumatically pre-accelerated hydrogen pellets measuring 3 mm in diameter and 4-9 mm in length were successfully accelerated by a railgun system that uses a laser-induced plasma armature formation. A 2 m long single railgun with ceramic insulators accelerated th hydrogen pellet to 2.6 kms -1 with a supplied energy of 1.7 kJ. The average acceleration rate and the energy conversion coefficient were improved to about 1.6 x 10 6 ms -2 and 0.37%, which is 1.6 times and three times as large as that using a railgun with plastic insulators, respectively. Furthermore, using the 1 m long augment railgun with ceramic insulators, the energy conversion coefficient was improved to about 0.55% while the acceleration rate was increased to 2.4 x 10 6 ms -2 . The highest hydrogen pellet velocity attained was about 2.3 kms -1 for the augment railgun under an energy supply of 1.1 kJ. Based on the findings, it is expected that the acceleration efficiency and the pellet velocity can be further improved by using a longer augment railgun with ceramic insulators and by applying an optimal power supply. (orig.)

First muon acceleration using a radio-frequency accelerator

Directory of Open Access Journals (Sweden)

S. Bae

2018-05-01

Full Text Available Muons have been accelerated by using a radio-frequency accelerator for the first time. Negative muonium atoms (Mu^{-}, which are bound states of positive muons (μ^{+} and two electrons, are generated from μ^{+}’s through the electron capture process in an aluminum degrader. The generated Mu^{-}’s are initially electrostatically accelerated and injected into a radio-frequency quadrupole linac (RFQ. In the RFQ, the Mu^{-}’s are accelerated to 89 keV. The accelerated Mu^{-}’s are identified by momentum measurement and time of flight. This compact muon linac opens the door to various muon accelerator applications including particle physics measurements and the construction of a transmission muon microscope.

Acceleration Modes and Transitions in Pulsed Plasma Accelerators

Science.gov (United States)

Polzin, Kurt A.; Greve, Christine M.

2018-01-01

Pulsed plasma accelerators typically operate by storing energy in a capacitor bank and then discharging this energy through a gas, ionizing and accelerating it through the Lorentz body force. Two plasma accelerator types employing this general scheme have typically been studied: the gas-fed pulsed plasma thruster and the quasi-steady magnetoplasmadynamic (MPD) accelerator. The gas-fed pulsed plasma accelerator is generally represented as a completely transient device discharging in approximately 1-10 microseconds. When the capacitor bank is discharged through the gas, a current sheet forms at the breech of the thruster and propagates forward under a j (current density) by B (magnetic field) body force, entraining propellant it encounters. This process is sometimes referred to as detonation-mode acceleration because the current sheet representation approximates that of a strong shock propagating through the gas. Acceleration of the initial current sheet ceases when either the current sheet reaches the end of the device and is ejected or when the current in the circuit reverses, striking a new current sheet at the breech and depriving the initial sheet of additional acceleration. In the quasi-steady MPD accelerator, the pulse is lengthened to approximately 1 millisecond or longer and maintained at an approximately constant level during discharge. The time over which the transient phenomena experienced during startup typically occur is short relative to the overall discharge time, which is now long enough for the plasma to assume a relatively steady-state configuration. The ionized gas flows through a stationary current channel in a manner that is sometimes referred to as the deflagration-mode of operation. The plasma experiences electromagnetic acceleration as it flows through the current channel towards the exit of the device. A device that had a short pulse length but appeared to operate in a plasma acceleration regime different from the gas-fed pulsed plasma

Enhanced dimethyl phthalate biodegradation by accelerating phthalic acid di-oxygenation.

Science.gov (United States)

Tang, Yingxia; Zhang, Yongming; Jiang, Ling; Yang, Chao; Rittmann, Bruce E

2017-12-01

The aerobic biodegradation of dimethyl phthalate (DMP) is initiated with two hydrolysis reactions that generate an intermediate, phthalic acid (PA), that is further biodegraded through a two-step di-oxygenation reaction. DMP biodegradation is inhibited when PA accumulates, but DMP's biodegradation can be enhanced by adding an exogenous electron donor. We evaluated the effect of adding succinate, acetate, or formate as an exogenous electron donor. PA removal rates were increased by 15 and 30% for initial PA concentrations of 0.3 and 0.6 mM when 0.15 and 0.30 mM succinate, respectively, were added as exogenous electron donor. The same electron-equivalent additions of acetate and formate had the same acceleration impacts on PA removal. Consequently, the DMP-removal rate, even PA coexisting with DMP simultaneously, was accelerated by 37% by simultaneous addition of 0.3 mM succinate. Thus, lowering the accumulation of PA by addition of an electron increased the rate of DMP biodegradation.

Evaluation and analysis of the residual radioactivity for the 15UD Pelletron accelerator facility

International Nuclear Information System (INIS)

Sonkawade, R. G.

2007-01-01

For the assessment of radiological impact of the accelerators, it will be better to have the documented information on activation of metal parts of the accelerator components. It is very much essential to get reliable data on these subjects. During acceleration of light ion, the residual radioactivity in the accelerator facility was found near the Analyzing Magnet, single slit, Beam Profile Monitors (BPM), Faraday Cups (FC), bellows, beginning of switching magnet bellows, at the target and the ladder. Study with HPGE detector gives an insight of the formation of the short or long lived radionuclides. The different targets used in the light ion experiment were also monitored and proper decommissioning and decontamination steps were followed. This paper presents the data of residual radioactivity in the 15UD Pelletron accelerator infrastructure. (author)

Accelerator development

International Nuclear Information System (INIS)

Anon.

1975-01-01

Because the use of accelerated heavy ions would provide many opportunities for new and important studies in nuclear physics and nuclear chemistry, as well as other disciplines, both the Chemistry and Physics Divisions are supporting the development of a heavy-ion accelerator. The design of greatest current interest includes a tandem accelerator with a terminal voltage of approximately 25 MV injecting into a linear accelerator with rf superconducting resonators. This combined accelerator facility would be capable of accelerating ions of masses ranging over the entire periodic table to an energy corresponding to approximately 10 MeV/nucleon. This approach, as compared to other concepts, has the advantages of lower construction costs, lower operating power, 100 percent duty factor, and high beam quality (good energy resolution, good timing resolution, small beam size, and small beam divergence). The included sections describe the concept of the proposed heavy-ion accelerator, and the development program aiming at: (1) investigation of the individual questions concerning the superconducting accelerating resonators; (2) construction and testing of prototype accelerator systems; and (3) search for economical solutions to engineering problems. (U.S.)

Accelerator Technology: Geodesy and Alignment for Particle Accelerators

CERN Document Server

Missiaen, D

2013-01-01

This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '8.9 Geodesy and Alignment for Particle Accelerators' of the Chapter '8 Accelerator Technology' with the content: 8.9 Geodesy and Alignment for Particle Accelerators 8.9.1 Introduction 8.9.2 Reference and Co-ordinate Systems 8.9.3 Definition of the Beam Line on the Accelerator Site 8.9.4 Geodetic Network 8.9.5 Tunnel Preliminary Works 8.9.6 The Alignment References 8.9.7 Alignment of Accelerator Components 8.9.8 Permanent Monitoring and Remote Alignment of Low Beta Quadrupoles 8.9.9 Alignment of Detector Components

Acceleration of electrons and supplementary ionization during parametrical plasma heating

International Nuclear Information System (INIS)

Grach, S.M.; Mityakov, N.A.; Trakhtengerts, V.Yu.; AN SSSR, Gor'kij. Inst. Prikladnoj Fiziki)

1986-01-01

Acceleration of electrons by plasma waves in partially ionized plasma is considered with provision for the effects of turbulent scattering and formation of secondary electrons, which are produced in the process of electron shock ionization. It is shown that the avalanche density growth of electrons accelerated up to 1-2 ionization potential (instability) takes place beginning from some critical density of plasma waves. Density of fast electrons is found out along with plasma wave energy density at the stage of instability saturation. Additional concentration of a background plasma, which manifests itself due to ionization, is evaluated

Permanent Magnets In Steerers Of The Beam Extracted From The Electron Accelerator

CERN Document Server

Dovbnya, A N; Shendrik, V A; Tolstoj, A E

2004-01-01

The results of test bench simulation and magnetic measurements were used to develop and manufacture "dipole magnet"-type units with a constant field of intensity up to 1.8 kOe in the working gap, 3 to 3.5 cm in height. The operating experience at the technological accelerators has shown that these devices are convenient in service, are easy-to-transport and can be used for solving the various problems in electron beam formation and steering at the exit of the accelerator.

Mitral valve-sparing procedures and prosthetic heart valve failure: A case report

Science.gov (United States)

Khan, Nasir A; Butany, Jagdish; Leong, Shaun W; Rao, Vivek; Cusimano, Robert J; Ross, Heather J

2009-01-01

Prosthetic heart valve dysfunction due to thrombus or pannus formation can be a life-threatening complication. The present report describes a 47-year-old woman who developed valvular cardiomyopathy after chorda-sparing mitral valve replacement, and subsequently underwent heart transplantation for progressive heart failure. The explanted mitral valve prosthesis showed significant thrombus and pannus leading to reduced leaflet mobility and valvular stenosis. The present report illustrates the role of the subvalvular apparatus and pannus in prosthesis dysfunction. PMID:19279993

2014 CERN Accelerator Schools: Plasma Wake Acceleration

CERN Multimedia

2014-01-01

A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

Virtual Accelerator for Accelerator Optics Improvement

CERN Document Server

Yan Yi Ton; Decker, Franz Josef; Ecklund, Stanley; Irwin, John; Seeman, John; Sullivan, Michael K; Turner, J L; Wienands, Ulrich

2005-01-01

Through determination of all quadrupole strengths and sextupole feed-downs by fitting quantities derivable from precision orbit measurement, one can establish a virtual accelerator that matches the real accelerator optics. These quantities (the phase advances, the Green's functions, and the coupling eigen-plane ellipses tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a model-independent analysis (MIA). Instead of trying to identify magnet errors, a limited number of quadrupoles are chosen for optimized strength adjustment to improve the virtual accelerator optics and then applied to the real accelerator accordingly. These processes have been successfully applied to PEP-II rings for beta beating fixes, phase and working tune adjustments, and linear coupling reduction to improve PEP-II luminosity.

Balloon catheter disruption of thrombus in conjunction with thrombolysis for the treatment of acute middle cerebral artery occlusion

International Nuclear Information System (INIS)

Liu Zhensheng; Wang Wei; Zhang Xinjiang; Fu Changbiao; Zhou Longjiang

2009-01-01

Objective: To assess the feasibility, safety, and efficacy of balloon disruption of thrombus by using a deflated balloon catheter combined with intra-arterial thrombolysis for the treatment of acute middle cerebral artery (MCA) occlusion. Methods: Five consecutive patients with acute MCA occlusion underwent balloon disruption combined with intra-arterial thrombolysis. The microballoon was inflated in the distal carotid artery and then deflated and advanced just distal to the occlusion site in the MCA. Thereafter, intra- arterial thrombolysis of the MCA was applied and the maximum dosage of urokinase was 500,000 U. Results: Complete recanalization was achieved in 3 patients and partial recanalization in 2. All patients got favourable clinical outcome. There was no major intracerebral hemorrhage. Conclusion: The penetration of the MCA with a deflated balloon catheter combined with an intra-arterial thrombolysis may be a safe and effective treatment for acute ischemic stroke. (authors)

Primitive neuroectodermal tumour of the kidney with vena caval and atrial tumour thrombus: a case report

Directory of Open Access Journals (Sweden)

Ong Poh

2008-08-01

Full Text Available Abstract Introduction Renal primitive neuroectodermal tumour is an extremely rare malignancy. Case presentation A 21-year-old woman presented with microscopic haematuria, a palpable right loin mass, dyspnoea, dizziness and fatigue. Initial ultrasound scan of the kidneys revealed an 11 cm right renal mass with venous extension into the inferior vena cava. Computed tomography of the thorax and abdomen revealed an extension of the large renal mass into the right renal vein, inferior vena cava and up to the right atrium. A small paracaval lymph node was noted and three small metastatic nodules were identified within the lung parenchyma. The patient underwent a radical nephrectomy and inferior vena caval tumour (level IV thrombectomy with cardiopulmonary bypass and deep hypothermic circulatory arrest. Immunohistochemical staining of the specimen showed a highly specific cluster of differentiation (CD 99, thus confirming the diagnosis of a primitive neuroectodermal tumour. Conclusion It is important that a renal primitive neuroectodermal tumour be considered, particularly in young patients with a renal mass and extensive thrombus.

Electron gun for formation of two high-current beams

International Nuclear Information System (INIS)

Borisov, A.R.; Zherlitsyn, A.G.; Mel'nikov, G.V.; Shtejn, Yu.G.

1982-01-01

The design of the ''Tonus'' accelerator electron gun for formation of two high-current beams aiming at the production of the maximum beam power and density is described. The results of investigation of two modes of beam formation are presented. In the first variant the beams were produced by means of two plane diodes with 40 mm diameter cathodes made of stainless steel and anodes made of 50 μm thick titanium foil. In the second variant the beams were formed by means of two coaxial diodes with magnetic insulation. In one diode the cathode diameter equals to 74 mm, the anode diameter - 92 mm, in the other diode 16 and 44 mm respectively. Current redistribution in the diodes and its effect on accelerating voltage are investigated. It is shown that the gun permits formation of synchronized two high-current beams, iaving equal electron energied. Wide range current control of both beams is possible

Morusinol extracted from Morus alba inhibits arterial thrombosis and modulates platelet activation for the treatment of cardiovascular disease.

Science.gov (United States)

Lee, Jung-Jin; Yang, Hyun; Yoo, Yeong-Min; Hong, Seong Su; Lee, Dongho; Lee, Hyun-Jung; Lee, Hak-Ju; Myung, Chang-Seon; Choi, Kyung-Chul; Jeung, Eui-Bae

2012-01-01

Morus alba (white mulberry) has been used in traditional Chinese medicine as an anti-headache, diuretic, expectorant, and anti-diabetic agent. In previous studies, extracts of Morus alba demonstrated favorable biological properties, such as antioxidant activity, suppression of lipoxygenase (LOX)-1, cytotoxicity against cancer cells, and inhibition of the invasion and migration of cancer cells. This study further evaluated the effects of morusinol, a flavonoid derived from Morus alba root bark, on platelet aggregation and thromboxane B(2) (TXB(2) formation in vitro and thrombus formation in vivo. The antiplatelet potential of morusinol was measured using in vitro rabbit platelet aggregation and TXB(2) formation assays. Arterial thrombus formation was investigated using an in vivo ferric chloride (FeCl(3)-induced thrombosis model. Morusinol significantly inhibited collagen- and arachidonic acid-induced platelet aggregation and TXB(2) formation in cultured platelets in a concentration-dependent manner. Thrombus formation was reduced by 32.1, 42.0, and 99.0% for collagen-induced TXB(2) formation, and 8.0, 24.1, and 29.2% for arachadonic acid-induced TXB(2) formation, with 5, 10, and 30 µg/mL morusinol, respectively. Moreover, oral morusinol (20 mg/kg) or aspirin (20 mg/kg) for three days significantly increased the time to occlusion in vivo by 20.3±5.0 or 6.8±2.9 min, respectively, compared with the control (1% CMC, carboxymethyl cellulose). Taken together, these results indicate that morusinol may significantly inhibit arterial thrombosis in vivo due to antiplatelet activity. Thus, morusinol may exert beneficial effects on transient ischemic attacks or stroke via the modulation of platelet activation.

Analyzing radial acceleration with a smartphone acceleration sensor

Science.gov (United States)

Vogt, Patrik; Kuhn, Jochen

2013-03-01

This paper continues the sequence of experiments using the acceleration sensor of smartphones (for description of the function and the use of the acceleration sensor, see Ref. 1) within this column, in this case for analyzing the radial acceleration.

High-speed hydrogen pellet acceleration using an electromagnetic railgun system

Energy Technology Data Exchange (ETDEWEB)

Onozuka, M.; Oda, Y. [Mitsubishi Heavy Ind., Ltd., Yokohama (Japan). Nucl. Fuel Cycle Eng. Dept.; Azuma, K.; Kasai, S.; Hasegawa, K. [Japan Atomic Energy Res. Inst., Tokai (Japan)

1997-07-01

Using a low electric energy railgun system, solid hydrogen pellet acceleration test have been conducted to investigate the application of the electromagnetic railgun system for high-speed pellet injection into fusion plasmas. Pneumatically pre-accelerated hydrogen pellets measuring 3 mm in diameter and 4-9 mm in length were successfully accelerated by a railgun system that uses a laser-induced plasma armature formation. A 2 m long single railgun with ceramic insulators accelerated th hydrogen pellet to 2.6 kms{sup -1} with a supplied energy of 1.7 kJ. The average acceleration rate and the energy conversion coefficient were improved to about 1.6 x 10{sup 6} ms{sup -2} and 0.37%, which is 1.6 times and three times as large as that using a railgun with plastic insulators, respectively. Furthermore, using the 1 m long augment railgun with ceramic insulators, the energy conversion coefficient was improved to about 0.55% while the acceleration rate was increased to 2.4 x 10{sup 6} ms{sup -2}. The highest hydrogen pellet velocity attained was about 2.3 kms{sup -1} for the augment railgun under an energy supply of 1.1 kJ. Based on the findings, it is expected that the acceleration efficiency and the pellet velocity can be further improved by using a longer augment railgun with ceramic insulators and by applying an optimal power supply. (orig.)

Value of platelet indices in identifying complete resolution of thrombus in deep venous thrombosis patients.

Science.gov (United States)

Sevuk, Utkan; Altindag, Rojhat; Bahadir, Mehmet Veysi; Ay, Nurettin; Demirtas, Ertan; Ayaz, Fırat

2015-03-01

We aimed to evaluate whether mean platelet volume (MPV) and platelet distribution width (PDW) are helpful to identify complete thrombus resolution (CTR) after acute deep venous thrombosis (DVT). Patients who had first-time episode of acute proximal DVT were included in this retrospective study. 100 patients with DVT were divided into two groups according to absence (group 1; n = 68) or presence (group 2; n = 32) of CTR on doppler ultrasonography at month 6. There were no significant difference in admission MPV and PDW levels between group 1 and group 2. MPV (p = 0.03) and PDW (p venous thrombosis in DVT patients. Receiver operating characteristics analysis revealed that a 8.4 % decrease in admission MPV at month 6 provided 62 % sensitivity and 62 % specificity (AUC: 0.64) and a 15.4 % decrease in admission PDW at month 6 provided 87 % sensitivity and 94 % specificity (AUC: 0.89) for prediction of CTR in DVT patients. Percent change in admission MPV and PDW levels at month 6 may be used to identify the patients with CTR after a first episode of acute proximal DVT.

Ion response to relativistic electron bunches in the blowout regime of laser-plasma accelerators.

Science.gov (United States)

Popov, K I; Rozmus, W; Bychenkov, V Yu; Naseri, N; Capjack, C E; Brantov, A V

2010-11-05

The ion response to relativistic electron bunches in the so called bubble or blowout regime of a laser-plasma accelerator is discussed. In response to the strong fields of the accelerated electrons the ions form a central filament along the laser axis that can be compressed to densities 2 orders of magnitude higher than the initial particle density. A theory of the filament formation and a model of ion self-compression are proposed. It is also shown that in the case of a sharp rear plasma-vacuum interface the ions can be accelerated by a combination of three basic mechanisms. The long time ion evolution that results from the strong electrostatic fields of an electron bunch provides a unique diagnostic of laser-plasma accelerators.