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Sample records for reduces thrombus size

  1. Performance of a thrombectomy device for aspiration of thrombus with various sizes based on a computational fluid dynamic modeling.

    PubMed

    Soleimani, Sajjad; Dubini, Gabriele; Pennati, Giancarlo

    2016-06-01

    It is important to thoroughly remove the thrombus within the course of aspiration thrombectomy; otherwise, it may lead to further embolization. The performance of the aspiration thrombectomy device with a generic geometry is studied through the computational approach. In order to model the thrombus aspiration, a real left coronary artery is chosen while thrombi with various sizes are located at the bifurcation area of the coronary artery and, depending on the size of the thrombus, it is stretched toward the side branches. The thrombus occupies the artery resembling the blood current obstruction in the coronary vessel similar to the situation that leads to heart attack. It is concluded that the aspiration ability of the thrombectomy device is not linked to the thrombus size; it is rather linked to the aspiration pressure and thrombus age (organized versus fresh thrombus). However, the aspiration time period correlates to the thrombus size. The minimum applicable aspiration pressure is also investigated in this study. PMID:26351782

  2. Platelet size and density affect shear-induced thrombus formation in tortuous arterioles

    NASA Astrophysics Data System (ADS)

    Chesnutt, Jennifer K. W.; Han, Hai-Chao

    2013-10-01

    Thrombosis accounts for 80% of deaths in patients with diabetes mellitus. Diabetic patients demonstrate tortuous microvessels and larger than normal platelets. Large platelets are associated with increased platelet activation and thrombosis, but the physical effects of large platelets in the microscale processes of thrombus formation are not clear. Therefore, the objective of this study was to determine the physical effects of mean platelet volume (MPV), mean platelet density (MPD) and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A computational model of the transport, shear-induced activation, collision, adhesion and aggregation of individual platelets was used to simulate platelet interactions and thrombus formation in tortuous arterioles. Our results showed that an increase in MPV resulted in a larger number of activated platelets, though MPD and level of tortuosity made little difference on platelet activation. Platelets with normal MPD yielded the lowest amount of mural thrombus. With platelets of normal MPD, the amount of mural thrombus decreased with increasing level of tortuosity but did not have a simple monotonic relationship with MPV. The physical mechanisms associated with MPV, MPD and arteriole tortuosity play important roles in platelet activation and thrombus formation.

  3. Nanoliposomal Growth Hormone and Sodium Nitrite Release from Silicone Fibers Reduces Thrombus Formation Under Flow.

    PubMed

    Salehi-Nik, Nasim; Amoabediny, Ghassem; Banikarimi, Seyedeh Parnian; Pouran, Behdad; Malaie-Balasi, Zahra; Zandieh-Doulabi, Behrouz; Klein-Nulend, Jenneke

    2016-08-01

    Biocompatibility of artificial lungs can be improved by endothelialization of hollow fibers. Bioavailability of growth-inducing and anti-thrombotic agents on the hollow fiber-blood interface inhibits thrombosis. We investigated if nanoliposomal growth-inducing growth hormone (nGH) and anti-thrombotic sodium nitrite (nNitrite) incorporation into collagen-coating on silicone hollow fibers improves blood biocompatibility by increasing endothelial cell growth and nitrite bioavailability under flow. Nitrite production rate was assessed under varying flow conditions. Finite element (FE) modeling was used to simulate nitrite transport within the parallel-plate flow chamber, and nitrite bioavailability on the fiber-blood interface at 1-30 dyn/cm(2) shear stress. Endothelial cell number on fibers coated with nNitrite-nGH-collagen conjugate was 1.5-fold higher than on collagen-coated fibers. For collagen-coated fibers, nitrite production reached a maximum at 18 dyn/cm(2) shear stress. When fibers were coated with nNitrite-nGH-collagen conjugate, nitrite production increased continuously by increasing shear stress. FE modeling revealed that nitrite concentrations at the fiber-blood interface were affected by shear stress-induced nitrite production, and diffusion/convection-induced nitrite removal. Highest nitrite concentrations and lowest thrombus deposition were observed on fibers coated with nNitrite-nGH-collagen conjugate exposed to 6-12 dyn/cm(2) shear stress. In conclusion, our results suggest that nNitrite-nGH-Col conjugate coatings promote endothelialization of silicone hollow fibers in biohybrid artificial lungs. PMID:26762283

  4. Thrombus aspiration in acute myocardial infarction.

    PubMed

    Mahmoud, Karim D; Zijlstra, Felix

    2016-07-01

    The success of primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is often hampered by incomplete microvascular myocardial reperfusion owing to distal embolization of thrombus resulting in microvascular obstruction. To address this problem, thrombus aspiration devices have been developed that can be used to evacuate coronary thrombus either manually or mechanically. Thrombus aspiration has the potential to reduce the local thrombus load, minimize the need for balloon predilatation, facilitate direct stenting, prevent distal embolization, and ultimately improve myocardial reperfusion. Furthermore, thrombus aspiration has enabled us to study coronary thrombus in vivo, and has facilitated recognition of distinct mechanisms of coronary thrombosis. Clinical trials focusing on manual thrombus aspiration in primary PCI have generally shown improved myocardial reperfusion. However, in two large trials powered for clinical end points, no reduction in 1-year mortality or other adverse clinical events was observed with the use of this strategy. Moreover, one of these trials showed a marginally increased risk of stroke. Consequently, current guidelines do not recommend routine use of thrombus aspiration. Future studies should focus on the identification of subgroups of patients with STEMI who might derive benefit from manual thrombus aspiration, and establish the effect of operator performance on the efficacy and safety of the procedure. PMID:26961064

  5. Reducing Class Size To Increase Student Involvement.

    ERIC Educational Resources Information Center

    Lottes, Christine R.

    Reducing class size was considered an important element in a revised health course at Gettysburg College (Pennsylvania). However, reducing class size to approximately 15 students per class would require 38 sections, more than the health faculty could handle. To recruit additional instructors, the course was marketed to faculty and administrators…

  6. The fluid mechanics of thrombus formation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Experimental data are presented for the growth of thrombi (blood clots) in a stagnation point flow of fresh blood. Thrombus shape, size and structure are shown to depend on local flow conditions. The evolution of a thrombus is described in terms of a physical model that includes platelet diffusion, a platelet aggregation mechanism, and diffusion and convection of the chemical species responsible for aggregation. Diffusion-controlled and convection-controlled regimes are defined by flow parameters and thrombus location, and the characteristic growth pattern in each regime is explained. Quantitative comparisons with an approximate theoretical model are presented, and a more general model is formulated.

  7. Clinical Sequelae of Thrombus in an Inferior Vena Cava Filter

    SciTech Connect

    Ahmad, Iftikhar; Yeddula, Kalpana; Wicky, Stephan; Kalva, Sanjeeva P.

    2010-04-15

    The purpose of this study was to assess the long-term clinical sequelae of inferior vena cava (IVC) filter thrombus and the effect of anticoagulation on filter thrombus. Of 1,718 patients who had IVC filters placed during 2001-2008, 598 (34.8%) had follow-up abdominal CT. Filter thrombus was seen in 111 of the 598 (18.6%). There were 44 men (39.6%). The mean age at filter placement was 64 years. The medical diseases included cancer in 64, trauma in 15, stroke in 12, and others in 20. The frequency of filter thrombus on CT and asymptomatic filter thrombus on CT was calculated. The frequency of pulmonary embolism (PE) in patients with filter thrombus was calculated. The frequency of thrombus progression or regression (on CT, available in 56) was calculated. The effect of anticoagulation on filter thrombus regression/progression was evaluated using the Fisher exact test by comparing the group of patients who received anticoagulants versus those who did not. A P-value of <0.05 was considered significant. The overall frequency of filter thrombus was 18.6%. Total occlusion of the IVC filter was seen in 12 of 598 (2%). The filter thrombus was asymptomatic in 110 (18.3%). Filter thrombus was detected after a median of 35 days (range, 0-2082) following filter placement. Thrombus extended above the filter in 4 (3.6%); IVC thrombus below the filter was seen in 35(31.5%). Thrombus in the filter occluded <25% of the filter volume in 58 (52.3%), 25-50% in 21 (18.9%), and 50-75% in 20 (18%). Total IVC occlusion was seen in 12 (10.8%). Eighty-three patients received anticoagulation. Sixteen patients developed symptoms of PE. PE was confirmed on CT in 3 of 15 (2.7%). On follow-up, filter thrombus regressed completely in 19 (33.9%) after a median of 6 months. Filter thrombus decreased in size in 13 (23.2%) and it progressed without IVC occlusion in 7 (12.6%). In one (1.7%), filter thrombus progressed to IVC occlusion. Filter thrombus remained stable in 16 (28.6%). There was no

  8. Effect of Red Blood Cells on Platelet Activation and Thrombus Formation in Tortuous Arterioles

    PubMed Central

    Chesnutt, Jennifer K. W.; Han, Hai-Chao

    2013-01-01

    Thrombosis is a major contributor to cardiovascular disease, which can lead to myocardial infarction and stroke. Thrombosis may form in tortuous microvessels, which are often seen throughout the human body, but the microscale mechanisms and processes are not well understood. In straight vessels, the presence of red blood cells (RBCs) is known to push platelets toward walls, which may affect platelet aggregation and thrombus formation. However in tortuous vessels, the effects of RBC interactions with platelets in thrombosis are largely unknown. Accordingly, the objective of this work was to determine the physical effects of RBCs, platelet size, and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A discrete element computational model was used to simulate the transport, collision, adhesion, aggregation, and shear-induced platelet activation of hundreds of individual platelets and RBCs in thrombus formation in tortuous arterioles. Results showed that high shear stress near the inner sides of curved arteriole walls activated platelets to initiate thrombosis. RBCs initially promoted platelet activation, but then collisions of RBCs with mural thrombi reduced the amount of mural thrombus and the size of emboli. In the absence of RBCs, mural thrombus mass was smaller in a highly tortuous arteriole compared to a less tortuous arteriole. In the presence of RBCs however, mural thrombus mass was larger in the highly tortuous arteriole compared to the less tortuous arteriole. As well, smaller platelet size yielded less mural thrombus mass and smaller emboli, either with or without RBCs. This study shed light on microscopic interactions of RBCs and platelets in tortuous microvessels, which have implications in various pathologies associated with thrombosis and bleeding. PMID:25022613

  9. Thrombus formation in vivo

    PubMed Central

    Furie, Bruce; Furie, Barbara C.

    2005-01-01

    To examine thrombus formation in a living mouse, new technologies involving intravital videomicroscopy have been applied to the analysis of vascular windows to directly visualize arterioles and venules. After vessel wall injury in the microcirculation, thrombus development can be imaged in real time. These systems have been used to explore the role of platelets, blood coagulation proteins, endothelium, and the vessel wall during thrombus formation. The study of biochemistry and cell biology in a living animal offers new understanding of physiology and pathology in complex biologic systems. PMID:16322780

  10. Reduced Boil-Off System Sizing

    NASA Technical Reports Server (NTRS)

    Guzik, Monica C.; Plachta, David W.; Feller, Jeffrey R.

    2015-01-01

    NASA is currently developing cryogenic propellant storage and transfer systems for future space exploration and scientific discovery missions by addressing the need to raise the technology readiness level of cryogenic fluid management technologies. Cryogenic propellants are baselined in many propulsion systems due to their inherently high specific impulse; however, their low boiling points can cause substantial boil-off losses over time. Recent efforts such as the Reduced Boil-off Testing and the Active Thermal Control Scaling Study provide important information on the benefit of an active cooling system applied to LH2 propellant storage. Findings show that zero-boil off technologies can reduce overall mass in LH2 storage systems when low Earth orbit loiter periods extend beyond two months. A significant part of this mass reduction is realized by integrating two stages of cooling: a 20 K stage to intercept heat at the tank surface, and a 90 K stage to reduce the heat entering the less efficient 20 K stage. A missing element in previous studies, which is addressed in this paper, is the development of a direct method for sizing the 90 K cooling stage. Such a method requires calculation of the heat entering both the 90 K and 20 K stages as compared to the overall system masses, and is reliant upon the temperature distribution, performance, and unique design characteristics of the system in question. By utilizing the known conductance of a system without active thermal control, the heat being intercepted by a 90 K stage can be calculated to find the resultant lift and mass of each active thermal control stage. Integral to this is the thermal conductance of the cooling straps and the broad area cooling shield, key parts of the 90 K stage. Additionally, a trade study is performed to show the ability of the 90 K cooling stage to reduce the lift on the 20 K cryocooler stage, which is considerably less developed and efficient than 90 K cryocoolers.

  11. The Paradox of Reducing Class Size and Improving Learning Outcomes

    ERIC Educational Resources Information Center

    Hattie, John

    2005-01-01

    This paper addresses four questions: What are the effects of reducing class size? How important are these effects? How can we explain these effects? and How can we improve the outcomes when class sizes are reduced? A major aim is to provide directions for resolving the paradox as to "Why reducing class size has not led to major improvements in…

  12. Radiopharmaceuticals for thrombus detection

    SciTech Connect

    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.

  13. Experimental Analysis of Reduced-Sized Coplanar Waveguide Transmission Lines

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.

    2002-01-01

    An experimental investigation of the use of capacitive loading of coplanar waveguides to reduce their line length and, thus the size, of monolithic microwave integrated circuits is presented. The reduced sized coplanar waveguides are compared to unloaded transmission lines and to lumped element transmission line segments. The phase bandwidth, defined by 2 percent error in S(sub 21), and the return loss bandwidth, defined by a return loss greater than 15 dB, of coplanar waveguides reduced from 0 to 90 percent are compared, and the insertion loss as a function of the size reduction is presented.

  14. Thrombus aspiration catheter is a Dottering balloon.

    PubMed

    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? PMID:27543477

  15. Parkinsonian patients reduce their stroke size with increased processing demands.

    PubMed

    Van Gemmert, A W; Teulings, H L; Stelmach, G E

    2001-12-01

    Parkinson's disease (PD) patients often show reductions in writing size (micrographia) as the length of the text they produce increases. The cause for these reductions in stroke size are not well understood. Reductions in stroke size could be associated with either concurrent processing demands that result from the coordination and control of fingers, wrist, and arm during writing and the processing of future words or increased extension of the wrist joint as the execution of the writing progresses to the right across the page, resulting in increased stiffness in the pen-limb system. Parkinson's patients and elderly controls wrote phrases of different lengths with target patterns in various serial positions. When the number of words to be written increased, PD patients reduced their stroke size of the initial target pattern, while the elderly controls did not reduce their stroke size. There was no systematic change in stroke size of the second pattern as function of serial position. This result suggests that PD patients reduce the size of their handwriting strokes when concurrent processing load increases. PMID:11748904

  16. Thrombus aspiration in ST-segment elevation myocardial infarction.

    PubMed

    Meneguz-Moreno, R A; Costa, R A; A, A; Ribamar Costa, J; Abizaid, A

    2015-12-01

    Primary percutaneous coronary intervention (PCI) has become the treatment of choice in patients with ST-segment elevation myocardial infarction (STEMI) throughout the last years. A significant number of studies have demonstrated a morbidity and mortality benefit over thrombolysis, which has been attributed to better coronary perfusion in patients undergoing primary PCI. Even though it usually achieves normal flow in the affected epicardial vessel, myocardial reperfusion is not fully restored in a significant percentage of patients. This is commonly the result of distal thrombus embolization with subsequent impairment of myocardial microcirculation. Recognition of this has led to the development of a number of devices with different mechanisms, including thrombus aspiration catheters, in order to reduce distal embolization and therefore improve myocardial perfusion. Recent studies indeed demonstrate that the use of such devices offer additional clinical advantage in patients undergoing primary PCI in comparison to the standard PCI, whether in other trials it could not be proved. This paper focuses on general mechanisms of thrombus formation and discusses favorable and unfavorable studies towards thrombus aspiration in STEMI and its main aspects and it comes up with specific subjects that could benefit or not from the procedure of thrombus aspiration. PMID:26603617

  17. Par4 is required for platelet thrombus propagation but not fibrin generation in a mouse model of thrombosis

    PubMed Central

    Vandendries, Erik R.; Hamilton, Justin R.; Coughlin, Shaun R.; Furie, Bruce; Furie, Barbara C.

    2007-01-01

    Thrombin, a central mediator of hemostasis and thrombosis, converts fibrinogen to fibrin and is a potent platelet activator. Activated platelets provide a surface for assembly of the tenase and prothrombinase complexes required for thrombin generation. The role of thrombin-induced platelet activation in platelet accumulation and its interplay with fibrin deposition during thrombus assembly has not been fully defined. We studied these processes during laser-induced thrombus formation by using real-time digital fluorescence microscopy in mice lacking protease-activated receptor-4 (Par4), which is necessary for thrombin responsiveness in mouse platelets. Juxtamural platelet accumulation immediately after laser injury was not different in wild-type and Par4−/− mice. However, subsequent growth of platelet thrombi was markedly diminished in Par4−/− mice. At the time of maximal thrombus size in wild type, platelet accumulation was more than 10-fold higher in wild type than in Par4−/− mice. P-selectin expression, a marker of platelet activation, was reduced and delayed in Par4−/− thrombi. In contrast to platelet activation and accumulation, the rate and amount of fibrin deposition, predominantly intramural and juxtamural in this model, were indistinguishable in Par4−/− and wild-type mice. These results suggest that platelet activation by thrombin is necessary for normal propagation of a platelet thrombus at a distance from the injured vessel wall and hence for normal thrombus growth. However, platelet activation by thrombin is unnecessary for initial and limited accumulation of platelets at or near the vessel wall, and this limited accumulation of platelets and/or platelet-independent mechanism(s) of thrombin generation are sufficient for normal fibrin deposition in this model. PMID:17190826

  18. Thrombus aspiration in acute myocardial infarction: concepts, clinical trials, and current guidelines.

    PubMed

    Vandermolen, Sebastian; Marciniak, Maciej; Byrne, Jonathan; De Silva, Kalpa

    2016-05-01

    The pathogenesis that underlies acute myocardial infarction is complex and multifactorial. One of the most important components, however, is the role of thrombus formation following atherosclerotic plaque rupture, leading to sudden coronary occlusion and subsequent ischemia and infarction. Thrombus aspiration provides the opportunity of intracoronary clot extraction with the aim to improve coronary and myocardial perfusion, by reducing the risk of no-reflow secondary to distal embolization of thrombus. The utility of thrombus aspiration during primary percutaneous coronary intervention has been assessed in an increasing number of observational and randomized studies. This article reviews the contemporary data and provides insights into the validity of thrombus aspiration in the setting of acute myocardial infarction. PMID:26751424

  19. Reducing myocardial infarct size: challenges and future opportunities

    PubMed Central

    Bulluck, Heerajnarain; Yellon, Derek M; Hausenloy, Derek J

    2016-01-01

    Despite prompt reperfusion by primary percutaneous coronary intervention (PPCI), the mortality and morbidity of patients presenting with an acute ST-segment elevation myocardial infarction (STEMI) remain significant with 9% death and 10% heart failure at 1 year. In these patients, one important neglected therapeutic target is ‘myocardial reperfusion injury’, a term given to the cardiomyocyte death and microvascular dysfunction which occurs on reperfusing ischaemic myocardium. A number of cardioprotective therapies (both mechanical and pharmacological), which are known to target myocardial reperfusion injury, have been shown to reduce myocardial infarct (MI) size in small proof-of-concept clinical studies—however, being able to demonstrate improved clinical outcomes has been elusive. In this article, we review the challenges facing clinical cardioprotection research, and highlight future therapies for reducing MI size and preventing heart failure in patients presenting with STEMI at risk of myocardial reperfusion injury. PMID:26674987

  20. Dabigatran for left ventricular thrombus.

    PubMed

    Kolekar, Satishkumar; Munjewar, Chandrashekhar; Sharma, Satyavan

    2015-01-01

    Male patient in dilated phase of hypertrophic cardiomyopathy had multiple hospitalizations during the past 2 years either due to congestive heart failure, stroke, scar epilepsy, or atrial fibrillation and ventricular tachycardia. Medication included evidence based therapy for heart failure, cordarone and warfarin. Anticoagulation had to be discontinued due to marked fluctuations in INR. Transthoracic Echocardiography (TTE) revealed a mobile mass in the left ventricle. He was treated with Dabigatran 110mg twice a day for 4 months without any bleeding or embolic episode and complete resolution of thrombus. Dabigatran is a reversible direct thrombin inhibitor and currently approved for the prevention of thromboembolic episodes in non-valvar atrial fibrillation. This case demonstrates possible thrombolytic properties of dabigatran in resolution of left ventricular thrombus. PMID:26432747

  1. Measurement of Thrombus Flux Using Transesophageal Echocardiography

    NASA Astrophysics Data System (ADS)

    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.

  2. Platelet Transport Rates and Binding Kinetics at High Shear over a Thrombus

    PubMed Central

    Bark, David L.; Ku, David N.

    2013-01-01

    Thrombus formation over a ruptured atherosclerotic plaque cap can occlude an artery with fatal consequences. We describe a computational model of platelet transport and binding to interpret rate-limiting steps seen in experimental thrombus formation over a collagen-coated stenosis. The model is used to compute shear rates in stenoses with growing boundaries. In the model, moving erythrocytes influence platelet transport based on shear-dependent enhanced diffusivity and a nonuniform platelet distribution. Adhesion is modeled as platelet-platelet binding kinetics. The results indicate that observed thrombus growth rates are limited by platelet transport to the wall for shear rates up to 6000 s−1. Above 7000 s−1, the thrombus growth rate is likely limited by binding kinetics (10−4 m/s). Thrombus growth computed from these rate-limiting steps match the thrombus location and occlusion times for experimental conditions if a lag time for platelet activation is included. Using fitted parameters, the model is then used to predict thrombus size and shape at a higher Reynolds number flow consistent with coronary artery disease. PMID:23870271

  3. Quantification of experimental venous thrombus resolution by longitudinal nanogold-enhanced micro-computed tomography

    PubMed Central

    Grover, Steven P.; Saha, Prakash; Jenkins, Julia; Mukkavilli, Arun; Lyons, Oliver T.; Patel, Ashish S.; Sunassee, Kavitha; Modarai, Bijan; Smith, Alberto

    2015-01-01

    Introduction The assessment of thrombus size following treatments directed at preventing thrombosis or enhancing its resolution has generally relied on physical or histological methods. This cross-sectional design imposes the need for increased numbers of animals for experiments. Micro-computed tomography (microCT) has been used to detect the presence of venous thrombus in experimental models but has yet to be used in a quantitative manner. In this study, we investigate the use of contrast-enhanced microCT for the longitudinal assessment of experimental venous thrombus resolution. Materials and methods Thrombi induced by stenosis of the inferior vena cava in mice were imaged by contrast-enhanced microCT at 1, 7 and 14 days post-induction (n = 18). Thrombus volumes were determined longitudinally by segmentation and 3D volume reconstruction of microCT scans and by standard end-point histological analysis at day 14. An additional group of thrombi were analysed solely by histology at 1, 7 and 14 days post-induction (n = 15). Results IVC resident thrombus was readily detectable by contrast-enhanced microCT. MicroCT-derived measurements of thrombus volume correlated well with time-matched histological analyses (ICC = 0.75, P < 0.01). Thrombus volumes measured by microCT were significantly greater than those derived from histological analysis (P < 0.001). Intra- and inter-observer analyses were highly correlated (ICC = 0.99 and 0.91 respectively, P < 0.0001). Further histological analysis revealed noticeable levels of contrast agent extravasation into the thrombus that was associated with the presence of neovascular channels, macrophages and intracellular iron deposits. Conclusion Contrast-enhanced microCT represents a reliable and reproducible method for the longitudinal assessment of venous thrombus resolution providing powerful paired data. PMID:26489729

  4. Variable Effect of P2Y12 Inhibition on Platelet Thrombus Volume in Flowing Blood

    PubMed Central

    Mendolicchio, G. L.; Zavalloni, D.; Bacci, M.; Corrada, E.; Marconi, M.; Lodigiani, C.; Presbitero, P.; Rota, L.; Ruggeri, Z. M.

    2010-01-01

    Background and objectives Patients treated by percutaneous coronary intervention (PCI) receive aspirin and P2Y12 ADP receptor inhibitors to reduce thrombotic complications. The choice of methodology for monitoring the effects of treatment and assessing its efficacy is still a topic of debate. We evaluated how decreased P2Y12 function influences platelet aggregate (thrombus) size measured ex vivo. Methods and Results We used confocal videomicroscopy to measure in real time the volume of platelet thrombi forming upon blood perfusion over fibrillar collagen type I at the wall shear rate of 1,500 s−1. The average volume was significantly smaller in 31 patients receiving aspirin and clopidogrel (19) or ticlopidine (12) than 21 controls, but individual values were above the lower limit of the normal distribution, albeit mostly within the lower quartile, in 61.3% of cases. Disaggregation of platelet thrombi at later perfusion times occurred frequently in the patients. Vasodilator-stimulated phosphoprotein (VASP) phosphorylation, reflecting P2Y12 inhibition, was also decreased in the patient group and only 22.6% of individual values were above the lower normal limit. We found no correlation between thrombus volume formed onto collagen fibrils and level of P2Y12 inhibition, suggesting that additional and individually variable factors can influence the inhibitory effect of treatment on platelet function. Conclusions Measuring platelet thrombus formation in flowing blood reflects the consequences of anti-platelet therapy in a manner that is not proportional to P2Y12 inhibition. Combining the results of the two assays may improve the assessment of thrombotic risk. PMID:21083646

  5. Tunable Reduced Size Planar Folded Slot Antenna Utilizing Varactor Diodes

    NASA Technical Reports Server (NTRS)

    Scardelletti, Maximilian C.; Ponchak, George E.; Jordan, Jennifer L.; Jastram, Nathan; Mahaffey, Joshua V.

    2010-01-01

    A tunable folded slot antenna that utilizes varactor diodes is presented. The antenna is fabricated on Rogers 6006 Duriod with a dielectric constant and thickness of 6.15 and 635 m, respectively. A copper cladding layer of 17 m defines the antenna on the top side (no ground on backside). The antenna is fed with a CPW 50 (Omega) feed line, has a center frequency of 3 GHz, and incorporates Micrometrics microwave hyper-abrupt 500MHV varactors to tune the resonant frequency. The varactors have a capacitance range of 2.52 pF at 0 V to 0.4 pF at 20 V; they are placed across the radiating slot of the antenna. The tunable 10 dB bandwidth of the 3 GHz antenna is 150 MHz. The varactors also reduce the size of the antenna by 30% by capacitively loading the resonating slot line. At the center frequency, 3 GHz, the antenna has a measured return loss of 44 dB and a gain of 1.6 dBi. Full-wave electromagnetic simulations using HFSS are presented that validate the measured data. Index Terms capacitive loading, Duriod, folded slot antenna, varactor.

  6. Plasma fibronectin promotes thrombus growth and stability in injured arterioles

    PubMed Central

    Ni, Heyu; Yuen, Peter S. T.; Papalia, Jessie M.; Trevithick, Jane E.; Sakai, Takao; Fässler, Reinhard; Hynes, Richard O.; Wagner, Denisa D.

    2003-01-01

    Mice lacking both of the best-known platelet ligands, von Willebrand factor and fibrinogen, can still form occlusive thrombi in injured arterioles. The platelets of these animals accumulate excessive amounts of fibronectin (FN). These observations led us to examine the contribution of plasma FN (pFN) to thrombus formation. Inactivation of the FN gene in FN conditional knockout mice reduced pFN levels to <2% and platelet FN to ≈20% of the levels in similarly treated control mice. The mice were then observed in a model of arterial injury to evaluate their capacity to form thrombi. The deficiency of pFN did not affect the initial platelet adhesion, but a delay of several minutes in thrombus formation was observed in the arterioles of pFN-deficient mice as compared with control mice. The thrombi that formed in the absence of pFN were stably anchored to the vessel wall but continuously shed platelets or small platelet clumps, thus slowing their growth significantly; the platelet/platelet cohesion was apparently diminished. Consequently the occlusion of pFN-deficient vessels was delayed, with the majority of vessels remaining patent at the end of the 40-min observation period. We conclude that, in addition to von Willebrand factor and fibrinogen, FN plays a significant role in thrombus initiation, growth, and stability at arterial shear rates and that deficiency in each of the three platelet ligands has its own specific impact on platelet plug formation. PMID:12606706

  7. Synthesis And Characterization Of Reduced Size Ferrite Reinforced Polymer Composites

    SciTech Connect

    Borah, Subasit; Bhattacharyya, Nidhi S.

    2008-04-24

    Small sized Co{sub 1-x}Ni{sub x}Fe{sub 2}O{sub 4} ferrite particles are synthesized by chemical route. The precursor materials are annealed at 400, 600 and 800 C. The crystallographic structure and phases of the samples are characterized by X-ray diffraction (XRD). The annealed ferrite samples crystallized into cubic spinel structure. Transmission Electron Microscopy (TEM) micrographs show that the average particle size of the samples are <20 nm. Particulate magneto-polymer composite materials are fabricated by reinforcing low density polyethylene (LDPE) matrix with the ferrite samples. The B-H loop study conducted at 10 kHz on the toroid shaped composite samples shows reduction in magnetic losses with decrease in size of the filler sample. Magnetic losses are detrimental for applications of ferrite at high powers. The reduction in magnetic loss shows a possible application of Co-Ni ferrites at high microwave power levels.

  8. 13 CFR 121.802 - What size standards are applicable to reduced patent fees programs?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false What size standards are applicable to reduced patent fees programs? 121.802 Section 121.802 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS SIZE REGULATIONS Size Eligibility Provisions and Standards Size Eligibility Requirements for Paying Reduced...

  9. Reducing Router Forwarding Table Size Using Aggregation and Caching

    ERIC Educational Resources Information Center

    Liu, Yaoqing

    2013-01-01

    The fast growth of global routing table size has been causing concerns that the Forwarding Information Base (FIB) will not be able to fit in existing routers' expensive line-card memory, and upgrades will lead to a higher cost for network operators and customers. FIB Aggregation, a technique that merges multiple FIB entries into one, is probably…

  10. On being the right size: increased body size is associated with reduced telomere length under natural conditions.

    PubMed

    Ringsby, Thor Harald; Jensen, Henrik; Pärn, Henrik; Kvalnes, Thomas; Boner, Winnie; Gillespie, Robert; Holand, Håkon; Hagen, Ingerid Julie; Rønning, Bernt; Sæther, Bernt-Erik; Monaghan, Pat

    2015-12-01

    Evolution of body size is likely to involve trade-offs between body size, growth rate and longevity. Within species, larger body size is associated with faster growth and ageing, and reduced longevity, but the cellular processes driving these relationships are poorly understood. One mechanism that might play a key role in determining optimal body size is the relationship between body size and telomere dynamics. However, we know little about how telomere length is affected when selection for larger size is imposed in natural populations. We report here on the relationship between structural body size and telomere length in wild house sparrows at the beginning and end of a selection regime for larger parent size that was imposed for 4 years in an isolated population of house sparrows. A negative relationship between fledgling size and telomere length was present at the start of the selection; this was extended when fledgling size increased under the selection regime, demonstrating a persistent covariance between structural size and telomere length. Changes in telomere dynamics, either as a correlated trait or a consequence of larger size, could reduce potential longevity and the consequent trade-offs could thereby play an important role in the evolution of optimal body size. PMID:26631569

  11. Molecular MRI of intracranial thrombus in a rat ischemic stroke model

    PubMed Central

    Uppal, Ritika; Ay, Ilknur; Dai, Guangping; Kim, Young Ro; Sorensen, A. Gregory; Caravan, Peter

    2010-01-01

    Background and Purpose Intracranial thrombus is a principal feature in most ischemic stroke, and thrombus location and size may correlate with outcome and response to thrombolytic therapy. EP-2104R, a fibrin-specific molecular MR agent, was previously shown to enhance extracranial thrombi in animal models and recently, in clinical trials. The purpose of this work was to determine if a fibrin-specific molecular MR probe could noninvasively characterize intracranial thrombi. Methods Embolic stroke was induced in adult rats by occlusion of the right internal carotid artery with an aged thrombus. Diffusion weighted imaging, time of flight angiography, and high resolution three dimensional T1-weighted MRI were performed at 4.7T prior to and following contrast agents EP-2104R (10 µmol/kg, n=6) or Gd-DTPA (200 µmol/kg, control, n=5). Gd levels in thrombus, brain, and blood were determined by ex vivo elemental analysis. Results In all animals, MR angiography revealed a flow deficit and diffusion-weighted imaging showed a hyperintensity consistent with ischemia. EP-2104R-enhanced MRI resulted in visualization of all occlusive thrombi (6/6) as well as vessel wall enhancement in all 6 animals with high contrast to noise relative to blood (10.7 post EP-2104R vs. 0.54 pre, p<0.0001). Gd-DTPA injected animals showed no occlusive thrombus or vessel wall enhancement (0/5). The concentration of Gd in the thrombus post-EP2104 was 18 times that in the blood pool. Conclusions EP-2104R enhanced MRI successfully identifies intracranial thrombus in a rat embolic stroke model. PMID:20395615

  12. High Speed Gear Sized and Configured to Reduce Windage Loss

    NASA Technical Reports Server (NTRS)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)

    2013-01-01

    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  13. Thrombus burden and myocardial damage during primary percutaneous coronary intervention.

    PubMed

    Napodano, Massimo; Dariol, Gilberto; Al Mamary, Ahmed H; Marra, Martina Perazzolo; Tarantini, Giuseppe; D'Amico, Gianpiero; Frigo, Anna Chiara; Buja, Paolo; Razzolini, Renato; Iliceto, Sabino

    2014-05-01

    Large thrombus burden (LTB) lesions in the context of primary percutaneous coronary intervention (p-PCI) have been related to unsuccessful angiographic reperfusion and unfavorable clinical outcomes. However, the hazard of LTB treatment on myocardial damage has not been evaluated. We investigated the impact of LTB on myocardial damage using contrast-enhanced cardiac magnetic resonance (CE-CMR) in the setting of p-PCI. In 327 patients, who underwent p-PCI without thrombus aspiration within 12 hours from symptom onset, we prospectively assessed the impact of LTB on infarct size and microvascular damage using CE-CMR. LTB was defined by the presence of Thrombolysis In Myocardial Infarction thrombus score ≥3 in patent infarct-related artery (IRA); or by "cut-off" occlusion pattern and/or large reference vessel diameter (≥3.5 mm) in occluded IRA. One hundred ninety-seven patients (60.2%) showed LTB and 130 (39.8%) did not. Distal embolization occurred in 18.8% patients with versus 6.9% without LTB (p = 0.003). At CE-CMR, patients with LTB had larger infarct size index (27.5 ± 11.1 vs 22.1 ± 17.5, p = 0.009) and more often transmural necrosis (70.5% vs 55.4%, p = 0.008) compared with patients without LTB. Excluding patients with distal embolization, patients with LTB still had larger necrosis. At multivariate analysis, occluded (IRA) at baseline, anterior infarction, and presence of LTB predicted transmural necrosis. In conclusion, LTB in the setting of p-PCI is related to larger myocardial damage as detected by CE-CMR, regardless of angiographic detectable distal embolization. PMID:24630783

  14. Platelet receptor interplay regulates collagen-induced thrombus formation in flowing human blood.

    PubMed

    Siljander, Pia R-M; Munnix, Imke C A; Smethurst, Peter A; Deckmyn, Hans; Lindhout, Theo; Ouwehand, Willem H; Farndale, Richard W; Heemskerk, Johan W M

    2004-02-15

    The platelet glycoproteins (GPs) Ib, integrin alpha(2)beta(1), and GPVI are considered central to thrombus formation. Recently, their relative importance has been re-evaluated based on data from murine knockout models. To examine their relationship during human thrombus formation on collagen type I fibers at high shear (1000 s(-1)), we tested a novel antibody against GPVI, an immunoglobulin single-chain variable fragment, 10B12, together with specific antagonists for GPIb alpha (12G1 Fab(2)) and alpha(2)beta(1) (6F1 mAb or GFOGER-GPP peptide). GPVI was found to be crucial for aggregate formation, Ca(2+) signaling, and phosphatidylserine (PS) exposure, but not for primary adhesion, even with more than 97% receptor blockade. Inhibiting alpha(2)beta(1) revealed its involvement in regulating Ca(2+) signaling, PS exposure, and aggregate size. Both GPIb alpha and alpha(2)beta(1) contributed to primary adhesion, showing overlapping function. The coinhibition of receptors revealed synergism in thrombus formation: the coinhibition of adenosine diphosphate (ADP) receptors with collagen receptors further decreased adhesion and aggregation, and, crucially, the complete eradication of thrombus formation required the coinhibition of GPVI with either GPIb alpha or alpha(2)beta(1). In summary, human platelet deposition on collagen depends on the concerted interplay of several receptors: GPIb in synergy with alpha(2)beta(1) mediating primary adhesion, reinforced by activation through GPVI, which further regulates the thrombus formation. PMID:14563646

  15. Testing new submersible pumps for proper sizing and reduced costs

    SciTech Connect

    O'Toole, W.P.; O'Brien, J.B.

    1989-02-01

    This paper describes an ongoing program to improve overall submersible pump performance by Thums Long Beach Co., acting as contractor for the City of Long Beach, operator of the Long Beach Unit. Thums Long Beach Co. currently operates 700 submersible pump installations located on four manmade islands and one landfill pier location. The program began with spot testing of submersible pumps for Thums' use. It has evolved to 100% pump testing and the stipulation that only pumps with newly manufactured parts are acceptable. The primary goals of this program are to increase well production and to lower lifting costs. Critical to these goals is increasing the average length of run by using accurate pump-performance data to design equipment and by rejecting defective pumps before they are run. Increased production is realized from better designs. Lower lifting costs result from using more efficient pumps and a reduced frequency of pulling submersible equipment.

  16. Testing new submersible pumps for proper sizing and reduced costs

    SciTech Connect

    O'Toole, W.P.; O'Brien, J.B.

    1986-01-01

    This paper describes an ongoing program to improve overall submersible pump performance by Thums Long Beach Company, acting as Contractor of the City of Long Beach, Operator of the Long Beach Unit. Thums Long Beach Company currently operates 700 submersible pump installations located on four man-made islands and one land fill pier location. The program began with spot testing of submersible pumps for Thums' use. It has evolved to 100 percent pump testing and the stipulation that only pumps with newly manufactured parts are acceptable. The primary goals of this program are to increase well production and lower lifting costs. Critical to these goals is increasing the average length of run by using accurate pump performance data to design equipment and by rejecting defective pumps before they are run. Increased production is realized from better designs. Lower lifting costs result from utilizing higher efficiency pumps and a reduced frequency of pulling submersible equipment.

  17. Floating, non-occlusive, mobile aortic thrombus and splenic infarction associated with protein C deficiency.

    PubMed

    Sanon, Saurabh; Phung, Man Kien; Lentz, Rob; Buja, L Maximilian; Tung, Poyee Pansy; McPherson, David D; Fuentes, Francisco

    2009-12-01

    The authors report the case of a patient with isolated protein C deficiency detected later in life, presenting with a mobile aortic thrombus and splenic infarction. Only one such case has been previously described. This case emphasizes the importance of including the aorta in the search for a cause of systemic embolization and highlights the diagnostic options and management dilemmas. Although anticoagulation with subsequent reassessment of thrombus size can be considered for layered thrombi, mobile thrombi warrant early surgical intervention to minimize the risk for systemic embolization. This patient was treated surgically with encouraging results. PMID:19647398

  18. 43 CFR 4300.53 - Can BLM reduce the size of the land in my permit?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; ALASKA; REINDEER; GENERAL Changes in the Size of the Permit Area § 4300.53 Can BLM reduce the size of the... number of reindeer you are grazing; or (b) When disposal, withdrawal, natural causes, such as drought...

  19. 43 CFR 4300.53 - Can BLM reduce the size of the land in my permit?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...; ALASKA; REINDEER; GENERAL Changes in the Size of the Permit Area § 4300.53 Can BLM reduce the size of the... number of reindeer you are grazing; or (b) When disposal, withdrawal, natural causes, such as drought...

  20. 43 CFR 4300.53 - Can BLM reduce the size of the land in my permit?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...; ALASKA; REINDEER; GENERAL Changes in the Size of the Permit Area § 4300.53 Can BLM reduce the size of the... number of reindeer you are grazing; or (b) When disposal, withdrawal, natural causes, such as drought...

  1. 43 CFR 4300.53 - Can BLM reduce the size of the land in my permit?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...; ALASKA; REINDEER; GENERAL Changes in the Size of the Permit Area § 4300.53 Can BLM reduce the size of the... number of reindeer you are grazing; or (b) When disposal, withdrawal, natural causes, such as drought...

  2. Segregation of Platelet Aggregatory and Procoagulant Microdomains in Thrombus Formation Regulation by Transient Integrin Activation

    PubMed Central

    Munnix, Imke C.A.; Kuijpers, Marijke J.E.; Auger, Jocelyn; Thomassen, Christella M.L.G.D.; Panizzi, Peter; van Zandvoort, Marc A.M.; Rosing, Jan; Bock, Paul E.; Watson, Steve P.; Heemskerk, Johan W.M.

    2008-01-01

    Objective Platelets play a dual role in thrombosis by forming aggregates and stimulating coagulation. We investigated the commitment of platelets to these separate functions during collagen-induced thrombus formation in vitro and in vivo. Methods and Results High-resolution 2-photon fluorescence microscopy revealed that in thrombus formation under flow, fibrin(ogen)-binding platelets assembled into separate aggregates, whereas distinct patches of nonaggregated platelets exposed phosphatidylserine. The latter platelet population had inactivated αIibβ3 integrins and displayed increased binding of coagulation factors. Coated platelets, expressing serotonin binding sites, were not identified as a separate population. Thrombin generation and coagulation favored the transformation to phosphatidylserine-exposing platelets with inactivated integrins and reduced adhesion. Prolonged tyrosine phosphorylation in vitro resulted in secondary downregulation of active αIIbβ3. Conclusions These results lead to a new spatial model of thrombus formation, in which aggregated platelets ensure thrombus stability, whereas distinct patches of nonaggregated platelets effectuate procoagulant activity and generate thrombin and fibrin. Herein, the hemostatic activity of a developing thrombus is determined by the balance in formation of proaggregatory and procoagulant platelets. This balance is influenced by antiplatelet and anticoagulant medication. PMID:17761939

  3. Intra-aneurysmal thrombus modification after flow-diversion.

    PubMed

    Zanaty, Mario; Jabbour, Pascal M; Bou Sader, Roula; Chalouhi, Nohra; Tjoumakaris, Stavropoula; Rosenwasser, Robert H; Fernando Gonzalez, L

    2015-01-01

    Flow diversion has been successfully used to treat large and giant intracranial aneurysms that present with mass effect. We conducted a retrospective review, evaluating the modification of thrombi in this aneurysm type after treatment with the Pipeline Embolization Device (ev3 Endovascular, Plymouth, MN, USA) and the effects of these modifications on symptoms. Eight patients, seven of whom were female, harbored eight partially thrombosed large or giant aneurysms. Five of the eight aneurysms presented with symptomatic mass effect. At 1 year follow-up, complete occlusion occurred in 75% (6/8) of patients. On average, the longest thrombus diameter measured 22.31 mm before treatment and 14.05 mm 1 year afterwards. Seven of the eight thrombi regressed, as did their aneurysms. All six patients with shrunken thrombi had tremendous symptom improvement and became asymptomatic in the following year. The current findings seem to reflect the size variation of the intra-aneurysmal thrombus rather than the size of the aneurysm itself. PMID:25192591

  4. Left ventricular mass: Myxoma or thrombus?

    PubMed Central

    Raut, Monish S.; Maheshwari, Arun; Dubey, Sumir; Joshi, Sandip

    2015-01-01

    Patient with embolic episode should always be evaluated for cardiac mass. Mass in left ventricular can be a myxoma or thrombus even in a normal functioning heart. In either case, mobile mass with embolic potential should be surgically resected. PMID:25566719

  5. Application of cystoscope in surgical treatment of hepatocellular carcinoma with portal vein tumor thrombus.

    PubMed

    Li, Nan; Wei, Xu-Biao; Cheng, Shu-Qun

    2016-06-14

    Development of portal vein tumor thrombus deteriorates the prognosis of hepatocellular carcinoma, while surgical treatment can offer a promising prognosis for selected patients. However, the possibility of residual lesions in portal vein after conventional thrombectomy is a main risk factor leading to postoperative recurrence. Therefore, ensuring the complete removal of tumor thrombus during operation is critical to improve prognosis. For the first time, we report here one case of hepatocellular carcinoma with portal vein tumor thrombus in which cystoscope was successfully applied as a substitute of intravascular endoscope to visualize the cavity of the portal vein. The patient was a 61-year-old man with a 7-cm tumor in the right lobe of the liver, with tumor thrombus invading the right branch and adjacent to the conjunction of the portal vein. After removal of the tumor, the Olympus CYF-VA2 cystoscope was used to check the portal vein from the opening stump of the right branch of the portal vein. In this case, residual thrombus tissue was found near the opening stump and the conjunction of the portal vein. The residual lesion was carefully retrieved from the stump after retraction of the cystoscope. The procedure was repeated until no residual lesion was found. The whole duration time of thrombectomy was 22.5 (15 + 7.5) min. The patient was free from recurrence at 8 months after the procedure. Our work indicated that the cystoscope is a suitable substitute, with a proper size and function to check the portal vein system and ensure the curability of thrombectomy. Although well-designed clinic trails are still needed, this procedure may further improve the postoperative prognosis of hepatocellular carcinoma with portal vein tumor thrombus. PMID:27298574

  6. Application of cystoscope in surgical treatment of hepatocellular carcinoma with portal vein tumor thrombus

    PubMed Central

    Li, Nan; Wei, Xu-Biao; Cheng, Shu-Qun

    2016-01-01

    Development of portal vein tumor thrombus deteriorates the prognosis of hepatocellular carcinoma, while surgical treatment can offer a promising prognosis for selected patients. However, the possibility of residual lesions in portal vein after conventional thrombectomy is a main risk factor leading to postoperative recurrence. Therefore, ensuring the complete removal of tumor thrombus during operation is critical to improve prognosis. For the first time, we report here one case of hepatocellular carcinoma with portal vein tumor thrombus in which cystoscope was successfully applied as a substitute of intravascular endoscope to visualize the cavity of the portal vein. The patient was a 61-year-old man with a 7-cm tumor in the right lobe of the liver, with tumor thrombus invading the right branch and adjacent to the conjunction of the portal vein. After removal of the tumor, the Olympus CYF-VA2 cystoscope was used to check the portal vein from the opening stump of the right branch of the portal vein. In this case, residual thrombus tissue was found near the opening stump and the conjunction of the portal vein. The residual lesion was carefully retrieved from the stump after retraction of the cystoscope. The procedure was repeated until no residual lesion was found. The whole duration time of thrombectomy was 22.5 (15 + 7.5) min. The patient was free from recurrence at 8 months after the procedure. Our work indicated that the cystoscope is a suitable substitute, with a proper size and function to check the portal vein system and ensure the curability of thrombectomy. Although well-designed clinic trails are still needed, this procedure may further improve the postoperative prognosis of hepatocellular carcinoma with portal vein tumor thrombus. PMID:27298574

  7. Novel risk predictor for thrombus deposition in abdominal aortic aneurysms

    NASA Astrophysics Data System (ADS)

    Nestola, M. G. C.; Gizzi, A.; Cherubini, C.; Filippi, S.; Succi, S.

    2015-10-01

    The identification of the basic mechanisms responsible for cardiovascular diseases stands as one of the most challenging problems in modern medical research including various mechanisms which encompass a broad spectrum of space and time scales. Major implications for clinical practice and pre-emptive medicine rely on the onset and development of intraluminal thrombus in which effective clinical therapies require synthetic risk predictors/indicators capable of informing real-time decision-making protocols. In the present contribution, two novel hemodynamics synthetic indicators, based on a three-band decomposition (TBD) of the shear stress signal, are introduced. Extensive fluid-structure computer simulations of patient-specific scenarios confirm the enhanced risk-prediction capabilities of the TBD indicators. In particular, they permit a quantitative and accurate localization of the most likely thrombus deposition in realistic aortic geometries, where previous indicators would predict healthy operation. The proposed methodology is also shown to provide additional information and discrimination criteria on other factors of major clinical relevance, such as the size of the aneurysm.

  8. Factors influencing acute thrombus formation on carotid artery vascular grafts

    SciTech Connect

    Torem, S.; Schneider, P.A.; Paxton, L.D.; Yasuda, H.; Hanson, S.R.

    1988-10-01

    Scintillation camera imaging of 111Indium-labeled platelets has been used to measure acute thrombus formation on modified expanded Teflon (ePTFE) vascular grafts placed in the carotid arteries of normal baboons. Platelet deposition plateaued over 2 hr postoperatively and occurred primarily at the graft-vessel anastomoses. A positive correlation was found between the circulating platelet count in individual animals and the extent of early platelet thrombus deposition. Unmodified ePTFE grafts accumulated 4.6 +/- 1.2 x 10(9) platelets per graft, or 2.3 +/- 0.71 x 10(9) platelets per anastomosis. Acutely, platelet accumulation was reduced versus control graft results by coating the graft lumenal surfaces with a smooth layer of silicone rubber polymer (0.60 +/- 0.19 x 10(9) platelets per anastomosis; P less than 0.02) but not by coating the grafts using a plasma polymer based on methane, which did not modify graft texture (8.2 +/- 1.7 x 10(9) platelets per graft; P greater than 0.10). The benefit of the silicone rubber coating persisted for at least 48 hr. However, longer term patency was not preserved because 10 of 12 grafts placed had failed within 1 to 2 months.

  9. Thrombus in Transit through Patent Foramen Ovale.

    PubMed

    Baydoun, Hassan; Barakat, Iskander; Hatem, Elie; Chalhoub, Michel; Mroueh, Ali

    2013-01-01

    A thrombus in transit through a patent foramen ovale (PFO) with impending paradoxical embolism is an extremely rare event. Due to its transient nature, it is unable to identify the thrombus, and most of the cases have been reported at autopsy. We are reporting a case of thrombus straddling the foramen ovale which was diagnosed by echocardiography and treated surgically. Through this personal case, an exhaustive review of the literature was performed. There were 88 cases reported. We concluded that there is no medical consensus about the best option for treatment. Nevertheless, surgery, which is associated with fewer complications of recurrent embolic events than those of thrombolysis and anticoagulation, appeared to be the best approach in patients who are not at a high surgical risk. Anticoagulant treatment appears to be an acceptable therapeutic alternative to surgery, particularly in patients with comorbidities who are at high surgical risk and for patients with small PFO. Thrombolysis is linked to the highest mortality, which could be explained by the severity of the patient's initial presentation. In conclusion, and after the cumulative effects of these case reports, we propose a diagram consisting of the use of the three therapeutic options in the different clinical scenarios. PMID:24826281

  10. Thrombus in Transit through Patent Foramen Ovale

    PubMed Central

    Barakat, Iskander; Chalhoub, Michel

    2013-01-01

    A thrombus in transit through a patent foramen ovale (PFO) with impending paradoxical embolism is an extremely rare event. Due to its transient nature, it is unable to identify the thrombus, and most of the cases have been reported at autopsy. We are reporting a case of thrombus straddling the foramen ovale which was diagnosed by echocardiography and treated surgically. Through this personal case, an exhaustive review of the literature was performed. There were 88 cases reported. We concluded that there is no medical consensus about the best option for treatment. Nevertheless, surgery, which is associated with fewer complications of recurrent embolic events than those of thrombolysis and anticoagulation, appeared to be the best approach in patients who are not at a high surgical risk. Anticoagulant treatment appears to be an acceptable therapeutic alternative to surgery, particularly in patients with comorbidities who are at high surgical risk and for patients with small PFO. Thrombolysis is linked to the highest mortality, which could be explained by the severity of the patient's initial presentation. In conclusion, and after the cumulative effects of these case reports, we propose a diagram consisting of the use of the three therapeutic options in the different clinical scenarios. PMID:24826281

  11. Thrombus entrapped in patent foramen ovale: a rare form of thrombus in transit

    PubMed Central

    Bakhshi, Hooman; Meyghani, Zahra; Shakir, Zaid; Chen, Alexander; Kershner, Dawn

    2015-01-01

    In rare cases, thrombus in transit can be entrapped in a patent foramen ovale (PFO). A patient with this condition is at high risk of embolic stroke and death. Early diagnosis and treatment is essential to help prevent stroke and death in these cases. There is no universal management guideline for this rare condition. The decision between medical versus surgical treatment should be made individually for each patient. We present a case of thrombus in transit entrapped in a PFO that was treated medically by lifelong anticoagulation. PMID:26333859

  12. Influence of Thrombus Age on the Mechanical Thrombectomy Efficacy of the Amplatz Thrombectomy Device In Vitro

    SciTech Connect

    Grimm, Jan Jahnke, Thomas; Muhle, Claus; Heller, Martin; Mueller-Huelsbeck, Stefan

    2003-06-15

    Purpose: To determine the efficacy of thrombectomy for the Amplatz Thrombectomy Device (ATD) according to the age of the thrombus. Methods: Thrombectomy was performed with the 7 Fr or 8 Fr ATD. Five-day-old or 8-day-old thrombi were made from porcine blood by clotting within silicone tubes to be used in a flow model. Emboli sizes, weight, remaining thrombus and activation time were evaluated. Results: The age of the thrombus had no influence on the activation time necessary for complete thrombolysis. A significant difference was found in the overall amount of embolization only with the 7 Fr device although a similar trend was shown with the 8 Fr device. The amount of embolized thrombotic material was higher for both devices if older thrombi (i.e., 8 days old) we reprocessed. The overall impression was that the 8 Fr device showed slightly better results (less remaining thrombus and embolization). Conclusion: A tendency toward higher amounts of embolization was observed if older thrombi were used in the model. Therefore the interventional radiologist should be aware of the potentially higher risk of peripheral embolization when performing mechanical thrombectomy(with the ATD) in older thrombotic occlusions, especially since the higher rate of embolization was mainly due to an increased proportion of larger embolic particles (1 mm), which are clinically more significant.

  13. Defective PDI release from platelets and endothelial cells impairs thrombus formation in Hermansky-Pudlak syndrome

    PubMed Central

    Sharda, Anish; Kim, Sarah H.; Jasuja, Reema; Gopal, Srila; Flaumenhaft, Robert; Furie, Barbara C.

    2015-01-01

    Protein disulfide isomerase (PDI), secreted from platelets and endothelial cells after injury, is required for thrombus formation. The effect of platelet and endothelial cell granule contents on PDI-mediated thrombus formation was studied by intravital microscopy using a mouse model of Hermansky-Pudlak syndrome in which platelet dense granules are absent. Platelet deposition and fibrin generation were nearly absent, and extracellular PDI was significantly reduced in HPS6−/− mice after vascular injury. HPS6−/− platelets displayed impaired PDI secretion and impaired exocytosis of α granules, lysosomes, and T granules due to decreased sensitivity to thrombin, but these defects could be corrected by addition of subthreshold amounts of adenosine 5′-diphosphate (ADP). Human Hermansky-Pudlak syndrome platelets demonstrated similar characteristics. Infusion of wild-type platelets rescued thrombus formation in HPS6−/− mice. Human umbilical vein endothelial cells in which the HPS6 gene was silenced displayed impaired PDI secretion and exocytosis of Weibel-Palade bodies. Defective thrombus formation in Hermansky-Pudlak syndrome, associated with impaired exocytosis of residual granules in endothelial cells and platelets, the latter due to deficiency of ADP, is characterized by a defect in T granule secretion, a deficiency in extracellular PDI secretion, and impaired fibrin generation and platelet aggregation. Hermansky-Pudlak syndrome is an example of a hereditary disease whereby impaired PDI secretion contributes to a bleeding phenotype. PMID:25593336

  14. New method for treatment of inferior vena cava tumor thrombus – case study

    PubMed Central

    Nagy, Zoltán; Gyurkovics, Endre; Pajor, Péter; Tarjányi, Mária; Szijártó, Attila; Vari, Sandor G.

    2015-01-01

    Conventional surgical therapy for advanced renal venous tumor thrombi results in high morbidity, so there is a need for less invasive techniques. This report presents the first case of a successful inferior vena cava (IVC) tumor thrombus removal without complications with balloon catheter (BC) via internal jugular vein (IJV), called the venous tumor thrombus pushing with balloon catheter (VTTP BC). Under the control of transesophageal echocardiogram and fluoroscope, a balloon catheter was sleeved on the guide wire, which was already inserted into the right internal jugular vein (IJV) and was driven distally above the IVC tumor thrombus. The balloon was inflated to occlude the IVC for prevention of pulmonary embolization. After the occlusion, the guide wire was driven to the cavotomy and was opened at the ostium of the right renal vein. It was pulled at both ends and stretched to serve as a rail. The balloon was gently pushed toward the cavotomy and the thrombectomy was completed. This is a less invasive method for treatment of venous tumor thrombus level 3 that can reduce surgical time, blood loss, and complication rates compared to the existing surgical methods. Also, it can be performed without thoracotomy, cardiopulmonary bypass, hypothermic circulatory arrest, and liver mobilization. PMID:25891873

  15. Defective PDI release from platelets and endothelial cells impairs thrombus formation in Hermansky-Pudlak syndrome.

    PubMed

    Sharda, Anish; Kim, Sarah H; Jasuja, Reema; Gopal, Srila; Flaumenhaft, Robert; Furie, Barbara C; Furie, Bruce

    2015-03-01

    Protein disulfide isomerase (PDI), secreted from platelets and endothelial cells after injury, is required for thrombus formation. The effect of platelet and endothelial cell granule contents on PDI-mediated thrombus formation was studied by intravital microscopy using a mouse model of Hermansky-Pudlak syndrome in which platelet dense granules are absent. Platelet deposition and fibrin generation were nearly absent, and extracellular PDI was significantly reduced in HPS6(-/-) mice after vascular injury. HPS6(-/-) platelets displayed impaired PDI secretion and impaired exocytosis of α granules, lysosomes, and T granules due to decreased sensitivity to thrombin, but these defects could be corrected by addition of subthreshold amounts of adenosine 5'-diphosphate (ADP). Human Hermansky-Pudlak syndrome platelets demonstrated similar characteristics. Infusion of wild-type platelets rescued thrombus formation in HPS6(-/-) mice. Human umbilical vein endothelial cells in which the HPS6 gene was silenced displayed impaired PDI secretion and exocytosis of Weibel-Palade bodies. Defective thrombus formation in Hermansky-Pudlak syndrome, associated with impaired exocytosis of residual granules in endothelial cells and platelets, the latter due to deficiency of ADP, is characterized by a defect in T granule secretion, a deficiency in extracellular PDI secretion, and impaired fibrin generation and platelet aggregation. Hermansky-Pudlak syndrome is an example of a hereditary disease whereby impaired PDI secretion contributes to a bleeding phenotype. PMID:25593336

  16. Ultrasonic processor reduces drill-cuttings size and eliminates subsea mounds

    SciTech Connect

    Gaddy, D.E.

    1997-10-06

    Drill cuttings size reduction using ultrasonics eliminated a subsea clean-up and significantly reduced the environmental impact in a North Sea drilling project. Reduction in cuttings size allows for a wider areal dispersion when released into the ocean because they are held in suspension longer than larger sizes. Thus, ocean currents carry the smaller cuttings farther away from the well template, leaving a much wider footprint than larger cuttings sizes. This eliminates the pile-up of cuttings that otherwise would contaminate and harm the marine habitat.

  17. Ultrasound Detection of Superior Vena Cava Thrombus

    PubMed Central

    Birch, Aaron; Um, David; Laselle, Brooks

    2014-01-01

    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. PMID:25247051

  18. Reduced body size and cub recruitment in polar bears associated with sea ice decline.

    PubMed

    Rode, Karyn D; Amstrup, Steven C; Regehr, Eric V

    2010-04-01

    Rates of reproduction and survival are dependent upon adequate body size and condition of individuals. Declines in size and condition have provided early indicators of population decline in polar bears (Ursus maritimus) near the southern extreme of their range. We tested whether patterns in body size, condition, and cub recruitment of polar bears in the southern Beaufort Sea of Alaska were related to the availability of preferred sea ice habitats and whether these measures and habitat availability exhibited trends over time, between 1982 and 2006. The mean skull size and body length of all polar bears over three years of age declined over time, corresponding with long-term declines in the spatial and temporal availability of sea ice habitat. Body size of young, growing bears declined over time and was smaller after years when sea ice availability was reduced. Reduced litter mass and numbers of yearlings per female following years with lower availability of optimal sea ice habitat, suggest reduced reproductive output and juvenile survival. These results, based on analysis of a long-term data set, suggest that declining sea ice is associated with nutritional limitations that reduced body size and reproduction in this population. PMID:20437962

  19. Reduced body size and cub recruitment in polar bears associated with sea ice decline

    USGS Publications Warehouse

    Rode, K.D.; Amstrup, Steven C.; Regehr, E.V.

    2010-01-01

    Rates of reproduction and survival are dependent upon adequate body size and condition of individuals. Declines in size and condition have provided early indicators of population decline in polar bears (Ursus maritimus) near the southern extreme of their range. We tested whether patterns in body size, condition, and cub recruitment of polar bears in the southern Beaufort Sea of Alaska were related to the availability of preferred sea ice habitats and whether these measures and habitat availability exhibited trends over time, between 1982 and 2006. The mean skull size and body length of all polar bears over three years of age declined over time, corresponding with long-term declines in the spatial and temporal availability of sea ice habitat. Body size of young, growing bears declined over time and was smaller after years when sea ice availability was reduced. Reduced litter mass and numbers of yearlings per female following years with lower availability of optimal sea ice habitat, suggest reduced reproductive output and juvenile survival. These results, based on analysis of a longterm data set, suggest that declining sea ice is associated with nutritional limitations that reduced body size and reproduction in this population. ?? 2010 by the Ecological Society of America.

  20. Automated Entire Thrombus Density Measurements for Robust and Comprehensive Thrombus Characterization in Patients with Acute Ischemic Stroke

    PubMed Central

    Santos, Emilie M. M.; Niessen, Wiro J.; Yoo, Albert J.; Berkhemer, Olvert A.; Beenen, Ludo F.

    2016-01-01

    Background and Purpose In acute ischemic stroke (AIS) management, CT-based thrombus density has been associated with treatment success. However, currently used thrombus measurements are prone to inter-observer variability and oversimplify the heterogeneous thrombus composition. Our aim was first to introduce an automated method to assess the entire thrombus density and then to compare the measured entire thrombus density with respect to current standard manual measurements. Materials and Method In 135 AIS patients, the density distribution of the entire thrombus was determined. Density distributions were described using medians, interquartile ranges (IQR), kurtosis, and skewedness. Differences between the median of entire thrombus measurements and commonly applied manual measurements using 3 regions of interest were determined using linear regression. Results Density distributions varied considerably with medians ranging from 20.0 to 62.8 HU and IQRs ranging from 9.3 to 55.8 HU. The average median of the thrombus density distributions (43.5 ± 10.2 HU) was lower than the manual assessment (49.6 ± 8.0 HU) (p<0.05). The difference between manual measurements and median density of entire thrombus decreased with increasing density (r = 0.64; p<0.05), revealing relatively higher manual measurements for low density thrombi such that manual density measurement tend overestimates the real thrombus density. Conclusions Automatic measurements of the full thrombus expose a wide variety of thrombi density distribution, which is not grasped with currently used manual measurement. Furthermore, discrimination of low and high density thrombi is improved with the automated method. PMID:26765847

  1. The role of neovascularisation in the resolution of venous thrombus.

    PubMed

    Modarai, Bijan; Burnand, Kevin Guiver; Humphries, Julia; Waltham, Matthew; Smith, Alberto

    2005-05-01

    Deep vein thrombosis (DVT) can give rise to chronic debilitating complications, which are expensive to treat. Anticoagulation, the standard therapy for DVT, prevents propagation, but does not remove the existing thrombus, which undergoes slow natural resolution. Alternative forms of treatment that accelerate resolution may arise from a better understanding of the cellular and molecular pathways that regulate the natural resolution of thrombi. This review will outline our current understanding of the mechanisms of thrombus resolution and the role of neovascularisation in this process. Novel experimental treatments that may one day find clinical use are also discussed. The process of thrombus resolution resembles wound healing. The mainly monocytic inflammatory infiltrate, which develops, is associated with the appearance of vascular channels. These cells may drive resolution by encouraging angiogenesis, which contributes to restoration of the vein lumen. Significant numbers of bone marrow-derived progenitor cells have also been found in naturally resolving thrombi, but their precise phenotype and their role in thrombus recanalisation is unclear. Enhanced thrombus neovascularisation and rapid vein recanalisation have been achieved in experimental models with proangiogenic agents. Recent reports of the role of bone marrow-derived progenitor cells in the revascularisation of ischaemic tissues suggest that it may be possible to obtain the same effect by delivering pluripotent or lineage specific stem cells into thrombus. These cells could contribute to thrombus recanalisation by expressing a variety of proangiogenic cytokines or by lining the new vessels that appear within the thrombus. PMID:15886791

  2. Differential responses of nitrate reducer community size, structure, and activity to tillage systems.

    PubMed

    Chèneby, D; Brauman, A; Rabary, B; Philippot, L

    2009-05-01

    The main objective of this study was to determine how the size, structure, and activity of the nitrate reducer community were affected by adoption of a conservative tillage system as an alternative to conventional tillage. The experimental field, established in Madagascar in 1991, consists of plots subjected to conventional tillage or direct-seeding mulch-based cropping systems (DM), both amended with three different fertilization regimes. Comparisons of size, structure, and activity of the nitrate reducer community in samples collected from the top layer in 2005 and 2006 revealed that all characteristics of this functional community were affected by the tillage system, with increased nitrate reduction activity and numbers of nitrate reducers under DM. Nitrate reduction activity was also stimulated by combined organic and mineral fertilization but not by organic fertilization alone. In contrast, both negative and positive effects of combined organic and mineral fertilization on the size of the nitrate reducer community were observed. The size of the nitrate reducer community was a significant predictor of the nitrate reduction rates except in one treatment, which highlighted the inherent complexities in understanding the relationships the between size, diversity, and structure of functional microbial communities along environmental gradients. PMID:19304827

  3. Differential Responses of Nitrate Reducer Community Size, Structure, and Activity to Tillage Systems▿ †

    PubMed Central

    Chèneby, D.; Brauman, A.; Rabary, B.; Philippot, L.

    2009-01-01

    The main objective of this study was to determine how the size, structure, and activity of the nitrate reducer community were affected by adoption of a conservative tillage system as an alternative to conventional tillage. The experimental field, established in Madagascar in 1991, consists of plots subjected to conventional tillage or direct-seeding mulch-based cropping systems (DM), both amended with three different fertilization regimes. Comparisons of size, structure, and activity of the nitrate reducer community in samples collected from the top layer in 2005 and 2006 revealed that all characteristics of this functional community were affected by the tillage system, with increased nitrate reduction activity and numbers of nitrate reducers under DM. Nitrate reduction activity was also stimulated by combined organic and mineral fertilization but not by organic fertilization alone. In contrast, both negative and positive effects of combined organic and mineral fertilization on the size of the nitrate reducer community were observed. The size of the nitrate reducer community was a significant predictor of the nitrate reduction rates except in one treatment, which highlighted the inherent complexities in understanding the relationships the between size, diversity, and structure of functional microbial communities along environmental gradients. PMID:19304827

  4. Lymphoedema caused by idiopathic lymphatic thrombus.

    PubMed

    Hara, Hisako; Mihara, Makoto; Seki, Yukio; Koshima, Isao

    2013-12-01

    Primary lymphoedema includes some diseases whose genetic anomaly is detected and others whose pathology is unknown. In this article, we report a lymphatic thrombus found in a limb with lymphoedema during lymphatico-venous anastomosis (LVA). A 32-year-old man was aware of oedema in his left calcar pedis 3 years previously, which appeared without any trigger. Indocyanine green lymphography indicated lymphatic stasis in the left calf and thigh region, and we performed LVA for the patient. During the operation, we found yellow vessels, which were thought to be lymphatic vessels filled with a yellow solid substance, just beneath the superficial fascia at the left ankle. Pathological examination of the thrombi revealed hyaline material mixed with cell components. The cells were categorised as lymphatic endothelial cells, as they were positive for podoplanin. There was no evidence of malignancy. Causes of idiopathic lymphatic thrombus such as this may be one of the causes of so-called primary lymphoedema, and evaluation of such cases may be the first step towards elucidating the mechanisms involved in the development of primary lymphoedema. PMID:23643778

  5. Portion size me: plate-size induced consumption norms and win-win solutions for reducing food intake and waste.

    PubMed

    Wansink, Brian; van Ittersum, Koert

    2013-12-01

    Research on the self-serving of food has empirically ignored the role that visual consumption norms play in determining how much food we serve on different sized dinnerware. We contend that dinnerware provides a visual anchor of an appropriate fill-level, which in turn, serves as a consumption norm (Study 1). The trouble with these dinnerware-suggested consumption norms is that they vary directly with dinnerware size--Study 2 shows Chinese buffet diners with large plates served 52% more, ate 45% more, and wasted 135% more food than those with smaller plates. Moreover, education does not appear effective in reducing such biases. Even a 60-min, interactive, multimedia warning on the dangers of using large plates had seemingly no impact on 209 health conference attendees, who subsequently served nearly twice as much food when given a large buffet plate 2 hr later (Study 3). These findings suggest that people may have a visual plate-fill level--perhaps 70% full--that they anchor on when determining the appropriate consumption norm and serving themselves. Study 4 suggests that the Delboeuf illusion offers an explanation why people do not fully adjust away from this fill-level anchor and continue to be biased across a large range of dishware sizes. These findings have surprisingly wide-ranging win-win implications for the welfare of consumers as well as for food service managers, restaurateurs, packaged goods managers, and public policy officials. PMID:24341317

  6. New mechanism to reduce the size of the monopivot magnetic suspension blood pump: direct drive mechanism.

    PubMed

    Yamane, T; Nishida, M; Kijima, T; Maekawa, J

    1997-07-01

    Size reduction of the monopivot magnetic suspension blood pump has been achieved by reducing the size of the magnetic suspension and employing a direct drive mechanism in place of a brushless DC motor and a magnetic coupling. The flow has also been improved using a closed hollow impeller to remove flow obstruction at the inlet and using radial straight vanes to reduce the impeller speed by 30%. Hemolysis testing was conducted for the new models. Results showed that model DD1 presented only a slightly higher level of hemolysis than a regular extracorporeal centrifugal pump. PMID:9212927

  7. Reduced tabletability of roller compacted granules as a result of granule size enlargement.

    PubMed

    Sun, Changquan Calvin; Himmelspach, Micah W

    2006-01-01

    The mechanism for the frequently observed "loss of reworkability or tabletability" of dry-granulated (DG) powders was investigated in detail using microcrystalline cellulose (MCC). It was hypothesized that granule size enlargement is the primary mechanism to the phenomenon. Detrimental effects of size enlargement on tabletability of plastic materials are predictable based on the physical model of interparticulate bonding within a tablet. In absence of extensive fracture of particles/granules, larger particles/granules exhibit lower surface area available for bonding thus lower tensile strength when compressed under identical conditions. Size effects were first demonstrated using different grades of MCC powders, both whole and sieved, of different particle size distributions. Regardless grade and sieve fraction, larger particles always resulted in lower tabletability, that is, lower tensile strength at the same compaction pressure. It was subsequently shown that enlargement of granules also reduced powder tabletability regardless grade of MCC. Tabletability of sieved granules after roller compacted for one, two, and four times decreased monotonically with increasing granule size but independent of the total number of roller compaction. Moreover, tabletability of fine granules (44-106 microm) was higher than that of coarse MCC powder (Avicel PH-200). These results suggest that the primary mechanism for reduced tabletabilty of DG granules of MCC is granule size enlargement rather than "work-hardening." PMID:16315244

  8. Is Dabigatran As Effective As Warfarin on Cardiac Thrombus in a Patient With Atrial Fibrillation? A Challenging Question.

    PubMed

    Sunbul, Murat; Cincin, Altug; Mammadov, Ceyhun; Mutlu, Bulent

    2016-01-01

    Atrial fibrillation (AF) is an important risk factor for cardioembolic stroke. Warfarin is an effective treatment in reducing the risk of cardioembolic stroke in patients with AF. New anticoagulants have been widely using for stroke prophylaxis in patients with nonvalvular AF. Previous studies have suggested that thrombolytic therapy is effective treatment choice in patients with pulmonary embolisms. Warfarin therapy is also effective on prevention or treatment of cardiac thrombus in patients with AF. However, there are no evidence-based data on treatment of cardiac thrombus with new oral anticoagulants in patients with AF. In our case report, we reported an AF patient with cardiac thrombus and pulmonary embolism under dabigatran therapy. PMID:25415546

  9. Do antioxidant vitamins reduce infarct size following acute myocardial ischemia/reperfusion?

    PubMed

    Bellows, S D; Hale, S L; Simkhovich, B Z; Kay, G L; Kloner, R A

    1995-02-01

    There is controversy concerning the ability of antioxidant vitamins to reduce myocardial infarct size. We sought to determine whether a brief prophylactic treatment of vitamin C or vitamin C plus Trolox (a water-soluble form of vitamin E) could reduce myocardial infarct size in an experimental model. We used an anesthetized open-chest rabbit model in which a branch of the circumflex coronary artery was ligated for 30 minutes followed by 4 hours of reperfusion. Experiments were performed in a randomized and blinded fashion. An IV injection of normal saline pH balanced to 7.4 (control group n = 15), vitamin C (150 mg/kg, n = 14), or vitamin C plus Trolox (150 mg/kg plus 100 mg/kg, respectively, n = 15) was administered prior to coronary occlusion. Collateral blood flow during coronary occlusion was measured by radioactive microspheres, myocardial risk zone (AR) was assessed by blue dye injection, and myocardial infarct size (AN) was assessed by triphenyltetrazolium chloride staining. All rabbits received comparable ischemic insult: Collateral blood flow and AR were similar among all three groups. Infarct size, measured as a percent of AR, did not differ significantly among the controls (21%), vitamin C (29%), or the vitamin C plus Trolox (18%) groups. Therefore, in this ischemia/reperfusion model, antioxidant vitamins did not alter myocardial infarct size. PMID:7540423

  10. Visualization and analysis of biomaterial-centered thrombus formation within a defined crevice under flow.

    PubMed

    Jamiolkowski, Megan A; Pedersen, Drake D; Wu, Wei-Tao; Antaki, James F; Wagner, William R

    2016-07-01

    The blood flow pathway within a device, together with the biomaterial surfaces and status of the patient's blood, are well-recognized factors in the development of thrombotic deposition and subsequent embolization. Blood flow patterns are of particular concern for devices such as blood pumps (i.e. ventricular assist devices, VADs) where shearing forces can be high, volumes are relatively large, and the flow fields can be complex. However, few studies have examined the effect of geometric irregularities on thrombus formation on clinically relevant opaque materials under flow. The objective of this study was to quantify human platelet deposition onto Ti6Al4V alloys, as well as positive and negative control surfaces, in the region of defined crevices (∼50-150 μm in width) that might be encountered in many VADs or other cardiovascular devices. To achieve this, reconstituted fresh human blood with hemoglobin-depleted red blood cells (to achieve optical clarity while maintaining relevant rheology), long working optics, and a custom designed parallel plate flow chamber were employed. The results showed that the least amount of platelet deposition occurred in the largest crevice size examined, which was counterintuitive. The greatest levels of deposition occurred in the 90 μm and 53 μm crevices at the lower wall shear rate. The results suggest that while crevices may be unavoidable in device manufacturing, the crevice size might be tailored, depending on the flow conditions, to reduce the risk of thromboembolic events. Further, these data might be used to improve the accuracy of predictive models of thrombotic deposition in cardiovascular devices to help optimize the blood flow path and reduce device thrombogenicity. PMID:27156141

  11. Salmon calcitonin reduces food intake through changes in meal sizes in male rhesus monkeys

    PubMed Central

    Bello, Nicholas T.; Kemm, Matthew H.; Moran, Timothy H.

    2008-01-01

    Amylinergic mechanisms are believed to be involved in the control of appetite. This study examined the effects of the amylin agonist, salmon calcitonin, on food intake and meal patterns in adult male rhesus monkeys. Fifteen minutes before the onset of their 6-h daily feeding period, monkeys received intramuscular injections of various doses of salmon calcitonin (0.032, 0.056, 0.1, 0.32, and 1 μg/kg) or saline. Salmon calcitonin dose dependently reduced total daily and hourly food intake, with significant decreases at the 0.1, 0.32, and 1 μg/kg doses. Daily food intake was reduced by ∼35%, 62%, and 96%, at these doses, respectively. An analysis of meal patterns revealed that size of the first meal was significantly reduced across the dose range of 0.056 to 1 μg/kg, while average meal size was reduced with the 0.32 and 1 μg/kg doses. Meal number was only affected at the 1 μg/kg dose. Repeated 5-day administration of the 0.1 μg/kg dose resulted in a reduction in daily food intake only on injection day 2, while significant reductions in food intake were observed on all five injection days with a 0.32 μg/kg dose. Daily food intake was also reduced for 1 day after the termination of the 5-day injections of the 0.32 μg/kg salmon calcitonin dose. These sustained reductions in intake were expressed through decreases in meal size. These data demonstrate that salmon calcitonin acutely and consistently decreases food intake mainly through reductions in meal sizes in nonhuman primates. PMID:18480241

  12. Salmon calcitonin reduces food intake through changes in meal sizes in male rhesus monkeys.

    PubMed

    Bello, Nicholas T; Kemm, Matthew H; Moran, Timothy H

    2008-07-01

    Amylinergic mechanisms are believed to be involved in the control of appetite. This study examined the effects of the amylin agonist, salmon calcitonin, on food intake and meal patterns in adult male rhesus monkeys. Fifteen minutes before the onset of their 6-h daily feeding period, monkeys received intramuscular injections of various doses of salmon calcitonin (0.032, 0.056, 0.1, 0.32, and 1 microg/kg) or saline. Salmon calcitonin dose dependently reduced total daily and hourly food intake, with significant decreases at the 0.1, 0.32, and 1 microg/kg doses. Daily food intake was reduced by approximately 35%, 62%, and 96%, at these doses, respectively. An analysis of meal patterns revealed that size of the first meal was significantly reduced across the dose range of 0.056 to 1 microg/kg, while average meal size was reduced with the 0.32 and 1 microg/kg doses. Meal number was only affected at the 1 microg/kg dose. Repeated 5-day administration of the 0.1 microg/kg dose resulted in a reduction in daily food intake only on injection day 2, while significant reductions in food intake were observed on all five injection days with a 0.32 microg/kg dose. Daily food intake was also reduced for 1 day after the termination of the 5-day injections of the 0.32 microg/kg salmon calcitonin dose. These sustained reductions in intake were expressed through decreases in meal size. These data demonstrate that salmon calcitonin acutely and consistently decreases food intake mainly through reductions in meal sizes in nonhuman primates. PMID:18480241

  13. A Treatment Case of Endoscopic Removal of Left Ventricular Thrombus, During Coronary Artery Bypass Graft

    PubMed Central

    Park, Hyun-Seok; Ryu, Se-Min; Cho, Seong-Joon; Park, Sung-Min; Lim, Sun-Hye

    2014-01-01

    Left ventricular thrombus is a common complication related to acute myocardial infarction. Removing this with an incision of the free wall of the left ventricle may cause fatal cardiac dysfunction or arrhythmias. Furthermore, performing incision and suture on the fragile myocardium of an acute myocardial infarction patient may cause serious bleeding complications. If there is a patient with left ventricular thrombus who needs thoracotomy for another reason, the case is attempted with the thought that if effective intraventricular visualization and manipulation can be done, fatalities caused by incision and suture may be reduced. For patients undergoing cardiopulmonary bypass, if intracardiac manipulation is required, an endoscope can be used, and given the potential complications after the incision and suturing of the infarcted tissue, the benefits are deemed sufficient. PMID:25207261

  14. Possible benefits of catheters with lateral holes in coronary thrombus aspiration: a computational study for different clot viscosities and vacuum pressures.

    PubMed

    Soleimani, Sajjad; Dubini, Gabriele; Pennati, Giancarlo

    2014-10-01

    According to a number of clinical studies, coronary aspiration catheters are useful tools to remove a thrombus (blood clot) blocking a coronary artery. However, these thrombectomy devices may fail to remove the blood clot entirely. Few studies have been devoted to a systematic analysis of factors affecting clot aspiration. The geometric characteristics of the aspiration catheter, the physical properties of the thrombus, and the applied vacuum pressure are crucial parameters. In this study, the aspiration of a blood clot blocking a coronary bifurcation is computationally simulated. The clot is modeled as a highly viscous fluid, and a two-phase (blood and clot) problem is solved. The effects of geometric variations in the tip of the coronary catheter, including lateral hole size and location, are investigated considering different aspiration pressures and clot viscosities. A Bird-Carreau model is adopted for blood viscosity, while a power law model is used to describe the clot rheology. Computational results for blood clot aspiration show that the presence of holes in the lateral part of the tip of the catheter can be beneficial depending on clot viscosity, hole features, and applied aspiration pressure. In general, the holes are beneficial when the clot viscosity is low, while aspiration catheters without any extra lateral holes exhibit better performance for higher clot viscosity. However, when higher aspiration pressures are applied, the catheters tend to behave relatively similarly in removing clots with various viscosities, reducing the role of the clot viscosity. PMID:24571089

  15. Cathepsin G-Dependent Modulation of Platelet Thrombus Formation In Vivo by Blood Neutrophils

    PubMed Central

    Faraday, Nauder; Schunke, Kathryn; Saleem, Sofiyan; Fu, Juan; Wang, Bing; Zhang, Jian; Morrell, Craig; Dore, Sylvain

    2013-01-01

    Neutrophils are consistently associated with arterial thrombotic morbidity in human clinical studies but the causal basis for this association is unclear. We tested the hypothesis that neutrophils modulate platelet activation and thrombus formation in vivo in a cathepsin G-dependent manner. Neutrophils enhanced aggregation of human platelets in vitro in dose-dependent fashion and this effect was diminished by pharmacologic inhibition of cathepsin G activity and knockdown of cathepsin G expression. Tail bleeding time in the mouse was prolonged by a cathepsin G inhibitor and in cathepsin G knockout mice, and formation of neutrophil-platelet conjugates in blood that was shed from transected tails was reduced in the absence of cathepsin G. Bleeding time was highly correlated with blood neutrophil count in wildtype but not cathepsin G deficient mice. In the presence of elevated blood neutrophil counts, the anti-thrombotic effect of cathepsin G inhibition was greater than that of aspirin and additive to it when administered in combination. Both pharmacologic inhibition of cathepsin G and its congenital absence prolonged the time for platelet thrombus to form in ferric chloride-injured mouse mesenteric arterioles. In a vaso-occlusive model of ischemic stroke, inhibition of cathepsin G and its congenital absence improved cerebral blood flow, reduced histologic brain injury, and improved neurobehavioral outcome. These experiments demonstrate that neutrophil cathepsin G is a physiologic modulator of platelet thrombus formation in vivo and has potential as a target for novel anti-thrombotic therapies. PMID:23940756

  16. Management of Vertebral Stenosis Complicated by Presence of Acute Thrombus

    SciTech Connect

    Canyigit, Murat; Arat, Anil Cil, Barbaros E.; Sahin, Gurdal; Turkbey, Baris; Elibol, Bulent

    2007-04-15

    A 44-year-old male presented with multiple punctate acute infarcts of the vertebrobasilar circulation and a computed tomographic angiogram showing stenosis of the right vertebral origin. A digital subtraction angiogram demonstrated a new intraluminal filling defect at the origin of the stenotic vertebral artery where antegrade flow was maintained. This filling defect was accepted to be an acute thrombus of the vertebral origin, most likely due to rupture of a vulnerable plaque. The patient was treated with intravenous heparin. A control angiogram revealed dissolution of the acute thrombus under anticoagulation and the patient was treated with stenting with distal protection. Diffusion-weighted magnetic resonance imaging demonstrated no additional acute ischemic lesions. We were unable to find a similar report in the English literature documenting successful management of an acute vertebral ostial thrombus with anticoagulation. Anticoagulation might be considered prior to endovascular treatment of symptomatic vertebral stenoses complicated by the presence of acute thrombus.

  17. Concentration Effect of Reducing Agents on Green Synthesis of Gold Nanoparticles: Size, Morphology, and Growth Mechanism.

    PubMed

    Kim, Hyun-Seok; Seo, Yu Seon; Kim, Kyeounghak; Han, Jeong Woo; Park, Youmie; Cho, Seonho

    2016-12-01

    Under various concentration conditions of reducing agents during the green synthesis of gold nanoparticles (AuNPs), we obtain the various geometry (morphology and size) of AuNPs that play a crucial role in their catalytic properties. Through both theoretical and experimental approaches, we studied the relationship between the concentration of reducing agent (caffeic acid) and the geometry of AuNPs. As the concentration of caffeic acid increases, the sizes of AuNPs were decreased due to the adsorption and stabilizing effect of oxidized caffeic acids (OXCAs). Thus, it turns out that optimal concentration exists for the desired geometry of AuNPs. Furthermore, we investigated the growth mechanism for the green synthesis of AuNPs. As the caffeic acid is added and adsorbed on the surface of AuNPs, the aggregation mechanism and surface free energy are changed and consequently resulted in the AuNPs of various geometry. PMID:27119158

  18. Concentration Effect of Reducing Agents on Green Synthesis of Gold Nanoparticles: Size, Morphology, and Growth Mechanism

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-seok; Seo, Yu Seon; Kim, Kyeounghak; Han, Jeong Woo; Park, Youmie; Cho, Seonho

    2016-04-01

    Under various concentration conditions of reducing agents during the green synthesis of gold nanoparticles (AuNPs), we obtain the various geometry (morphology and size) of AuNPs that play a crucial role in their catalytic properties. Through both theoretical and experimental approaches, we studied the relationship between the concentration of reducing agent (caffeic acid) and the geometry of AuNPs. As the concentration of caffeic acid increases, the sizes of AuNPs were decreased due to the adsorption and stabilizing effect of oxidized caffeic acids (OXCAs). Thus, it turns out that optimal concentration exists for the desired geometry of AuNPs. Furthermore, we investigated the growth mechanism for the green synthesis of AuNPs. As the caffeic acid is added and adsorbed on the surface of AuNPs, the aggregation mechanism and surface free energy are changed and consequently resulted in the AuNPs of various geometry.

  19. A DRAMATICALLY REDUCED SIZE IN THE GANTRY DESIGN FOR THE PROTON-CARBON THERAPY.

    SciTech Connect

    TRBOJEVIC, D.; GUPTA, R.; PARKER, B.; KEIL, E.; SESSLER, A.M.

    2006-06-23

    Gantries in the proton/carbon cancer therapy machines represent the major cost and are of the largest size. This report explains a new way to the gantry design. The size and cost of the gantries are reduced and their use is simplified by using the fixed magnetic field. The ''new'' gantry is made of a very large momentum acceptance non-scaling Fixed Field Alternating Gradient (FFAG) quarter and half arc beam lines. The gantry is made of combined function magnets with a very strong focusing and small dispersion function. Additional magnets with a fast response are required to allow adjustments of the beam position for different energies at the beginning of the gantry. Additional strong focusing magnets following the gantry have also to be adjustable to provide required spot size and radial scanning above the patients. The fixed field combined function magnets could be made of small permanent magnets for the proton machine, or of the high temperature superconductors or superconductors for the carbon machine, reducing dramatically the size.

  20. A biologically active surface enzyme assembly that attenuates thrombus formation

    PubMed Central

    Qu, Zheng; Muthukrishnan, Sharmila; Urlam, Murali K.; Haller, Carolyn A.; Jordan, Sumanas W.; Kumar, Vivek A.; Marzec, Ulla M.; Elkasabi, Yaseen; Lahann, Joerg; Hanson, Stephen R.

    2013-01-01

    Activation of hemostatic pathways by blood-contacting materials remains a major hurdle in the development of clinically durable artificial organs and implantable devices. We postulate that surface-induced thrombosis may be attenuated by the reconstitution onto blood contacting surfaces of bioactive enzymes that regulate the production of thrombin, a central mediator of both clotting and platelet activation cascades. Thrombomodulin (TM), a transmembrane protein expressed by endothelial cells, is an established negative regulator of thrombin generation in the circulatory system. Traditional techniques to covalently immobilize enzymes on solid supports may modify residues contained within or near the catalytic site, thus reducing the bioactivity of surface enzyme assemblies. In this report, we present a molecular engineering and bioorthogonal chemistry approach to site-specifically immobilize a biologically active recombinant human TM fragment onto the luminal surface of small diameter prosthetic vascular grafts. Bioactivity and biostability of TM modified grafts is confirmed in vitro and the capacity of modified grafts to reduce platelet activation is demonstrated using a non-human primate model. These studies indicate that molecularly engineered interfaces that display TM actively limit surface-induced thrombus formation. PMID:23532366

  1. Configuring the mesh size, side taper and wing depth of penaeid trawls to reduce environmental impacts.

    PubMed

    Broadhurst, Matt K; Sterling, David J; Millar, Russell B

    2014-01-01

    The effects of reducing mesh size while concomitantly varying the side taper and wing depth of a generic penaeid-trawl body were investigated to improve engineering performance and minimize bycatch. Five trawl bodies (with the same codends) were tested across various environmental (e.g. depth and current) and biological (e.g. species and sizes) conditions. The first trawl body comprised 41-mm mesh and represented conventional designs (termed the '41 long deep-wing'), while the remaining trawl bodies were made from 32-mm mesh and differed only in their side tapers, and therefore length (i.e. 1N3B or 'long' and ∼28o to the tow direction vs 1N5B or 'short' and ∼35o) and wing depths ('deep'-97 T vs 'shallow'-60 T). There were incremental drag reductions (and therefore fuel savings--by up to 18 and 12% per h and ha trawled) associated with reducing twine area via either modification, and subsequently minimizing otter-board area in attempts to standardize spread. Side taper and wing depth had interactive and varied effects on species selectivity, but compared to the conventional 41 long deep-wing trawl, the 32 short shallow-wing trawl (i.e. the least twine area) reduced the total bycatch by 57% (attributed to more fish swimming forward and escaping). In most cases, all small-meshed trawls also caught more smaller school prawns Metapenaeus macleayi but to decrease this effect it should be possible to increase mesh size slightly, while still maintaining the above engineering benefits and species selectivity. The results support precisely optimizing mesh size as a precursor to any other anterior penaeid-trawl modifications designed to improve environmental performance. PMID:24911786

  2. Configuring the Mesh Size, Side Taper and Wing Depth of Penaeid Trawls to Reduce Environmental Impacts

    PubMed Central

    Broadhurst, Matt K.; Sterling, David J.; Millar, Russell B.

    2014-01-01

    The effects of reducing mesh size while concomitantly varying the side taper and wing depth of a generic penaeid-trawl body were investigated to improve engineering performance and minimize bycatch. Five trawl bodies (with the same codends) were tested across various environmental (e.g. depth and current) and biological (e.g. species and sizes) conditions. The first trawl body comprised 41-mm mesh and represented conventional designs (termed the ‘41 long deep-wing'), while the remaining trawl bodies were made from 32-mm mesh and differed only in their side tapers, and therefore length (i.e. 1N3B or ‘long’ and ∼28o to the tow direction vs 1N5B or ‘short’ and ∼35o) and wing depths (‘deep’–97 T vs ‘shallow’–60 T). There were incremental drag reductions (and therefore fuel savings – by up to 18 and 12% per h and ha trawled) associated with reducing twine area via either modification, and subsequently minimizing otter-board area in attempts to standardize spread. Side taper and wing depth had interactive and varied effects on species selectivity, but compared to the conventional 41 long deep-wing trawl, the 32 short shallow-wing trawl (i.e. the least twine area) reduced the total bycatch by 57% (attributed to more fish swimming forward and escaping). In most cases, all small-meshed trawls also caught more smaller school prawns Metapenaeus macleayi but to decrease this effect it should be possible to increase mesh size slightly, while still maintaining the above engineering benefits and species selectivity. The results support precisely optimizing mesh size as a precursor to any other anterior penaeid-trawl modifications designed to improve environmental performance. PMID:24911786

  3. Morphine Reduces Myocardial Infarct Size via Heat Shock Protein 90 in Rodents

    PubMed Central

    Small, Bryce A.; Lu, Yao; Hsu, Anna K.; Gross, Garrett J.; Gross, Eric R.

    2015-01-01

    Opioids reduce injury from myocardial ischemia-reperfusion in humans. In experimental models, this mechanism involves GSK3β inhibition. HSP90 regulates mitochondrial protein import, with GSK3β inhibition increasing HSP90 mitochondrial content. Therefore, we determined whether morphine-induced cardioprotection is mediated by HSP90 and if the protective effect is downstream of GSK3β inhibition. Male Sprague-Dawley rats, aged 8–10 weeks, were subjected to an in vivo myocardial ischemia-reperfusion injury protocol involving 30 minutes of ischemia followed by 2 hours of reperfusion. Hemodynamics were continually monitored and myocardial infarct size determined. Rats received morphine (0.3 mg/kg), the GSK3β inhibitor, SB216763 (0.6 mg/kg), or saline, 10 minutes prior to ischemia. Some rats received selective HSP90 inhibitors, radicicol (0.3 mg/kg), or deoxyspergualin (DSG, 0.6 mg/kg) alone or 5 minutes prior to morphine or SB216763. Morphine reduced myocardial infarct size when compared to control (42 ± 2% versus 60 ± 1%). This protection was abolished by prior treatment of radicicol or DSG (59 ± 1%, 56 ± 2%). GSK3β inhibition also reduced myocardial infarct size (41 ± 2%) with HSP90 inhibition by radicicol or DSG partially inhibiting SB216763-induced infarct size reduction (54 ± 3%, 47 ± 1%, resp.). These data suggest that opioid-induced cardioprotection is mediated by HSP90. Part of this protection afforded by HSP90 is downstream of GSK3β, potentially via the HSP-TOM mitochondrial import pathway. PMID:26413502

  4. A role for factor XIIa–mediated factor XI activation in thrombus formation in vivo

    PubMed Central

    Cheng, Qiufang; Tucker, Erik I.; Pine, Meghann S.; Sisler, India; Matafonov, Anton; Sun, Mao-fu; White-Adams, Tara C.; Smith, Stephanie A.; Hanson, Stephen R.; McCarty, Owen J. T.; Renné, Thomas; Gruber, András

    2010-01-01

    Mice lacking factor XII (fXII) or factor XI (fXI) are resistant to experimentally–induced thrombosis, suggesting fXIIa activation of fXI contributes to thrombus formation in vivo. It is not clear whether this reaction has relevance for thrombosis in pri mates. In 2 carotid artery injury models (FeCl3 and Rose Bengal/laser), fXII-deficient mice are more resistant to thrombosis than fXI- or factor IX (fIX)–deficient mice, raising the possibility that fXII and fXI function in distinct pathways. Antibody 14E11 binds fXI from a variety of mammals and interferes with fXI activation by fXIIa in vitro. In mice, 14E11 prevented arterial occlusion induced by FeCl3 to a similar degree to total fXI deficiency. 14E11 also had a modest beneficial effect in a tissue factor–induced pulmonary embolism model, indicating fXI and fXII contribute to thrombus formation even when factor VIIa/tissue factor initiates thrombosis. In baboons, 14E11 reduced platelet-rich thrombus growth in collagen-coated grafts inserted into an arteriovenous shunt. These data support the hypothesis that fXIIa-mediated fXI activation contributes to thrombus formation in rodents and primates. Since fXII deficiency does not impair hemostasis, targeted inhibition of fXI activation by fXIIa may be a useful antithrombotic strategy associated with a low risk of bleeding complications. PMID:20634381

  5. Outcomes after thrombus aspiration for ST elevation myocardial infarction: 1-year follow-up of the prospective randomised TOTAL trial

    PubMed Central

    Jolly, Sanjit S; Cairns, John A; Yusuf, Salim; Rokoss, Michael J; Gao, Peggy; Meeks, Brandi; Kedev, Sasko; Stankovic, Goran; Moreno, Raul; Gershlick, Anthony; Chowdhary, Saqib; Lavi, Shahar; Niemela, Kari; Bernat, Ivo; Cantor, Warren J; Cheema, Asim N; Steg, Philippe Gabriel; Welsh, Robert C; Sheth, Tej; Bertrand, Olivier F; Avezum, Alvaro; Bhindi, Ravinay; Natarajan, Madhu K; Horak, David; Leung, Raymond C M; Kassam, Saleem; Rao, Sunil V; El-Omar, Magdi; Mehta, Shamir R; Velianou, James L; Pancholy, Samir; Džavík, Vladimír

    2016-01-01

    Summary Background Two large trials have reported contradictory results at 1 year after thrombus aspiration in ST elevation myocardial infarction (STEMI). In a 1-year follow-up of the largest randomised trial of thrombus aspiration, we aimed to clarify the longer-term benefits, to help guide clinical practice. Methods The trial of routine aspiration ThrOmbecTomy with PCI versus PCI ALone in Patients with STEMI (TOTAL) was a prospective, randomised, investigator-initiated trial of routine manual thrombectomy versus percutaneous coronary intervention (PCI) alone in 10 732 patients with STEMI. Eligible adult patients (aged ≥18 years) from 87 hospitals in 20 countries were enrolled and randomly assigned (1:1) within 12 h of symptom onset to receive routine manual thrombectomy with PCI or PCI alone. Permuted block randomisation (with variable block size) was done by a 24 h computerised central system, and was stratified by centre. Participants and investigators were not masked to treatment assignment. The trial did not show a difference at 180 days in the primary outcome of cardiovascular death, myocardial infarction, cardiogenic shock, or heart failure. However, the results showed improvements in the surrogate outcomes of ST segment resolution and distal embolisation, but whether or not this finding would translate into a longer term benefit remained unclear. In this longer-term follow-up of the TOTAL study, we report the results on the primary outcome (cardiovascular death, myocardial infarction, cardiogenic shock, or heart failure) and secondary outcomes at 1 year. Analyses of the primary outcome were by modified intention to treat and only included patients who underwent index PCI. This trial is registered with ClinicalTrials.gov, number NCT01149044. Findings Between Aug 5, 2010, and July 25, 2014, 10 732 eligible patients were enrolled and randomly assigned to thrombectomy followed by PCI (n=5372) or to PCI alone (n=5360). After exclusions of patients who did not

  6. Anisotropic remastering for reducing feature sizes on UV nanoimprint lithography replica molds.

    PubMed

    Lausecker, E; Grydlik, M; Brehm, M; Bergmair, I; Mühlberger, M; Fromherz, T; Bauer, G

    2012-04-27

    We present an approach that uses existing nanoimprint molds and reduces the size of the resulting features significantly via a remastering process utilizing the anisotropic etchant tetramethylammonium hydroxide and a mold casting step. Inverted pyramidal structures and V-grooves were imprinted using these 2.5-dimensional (2.5D) replica molds. Pattern transfer into silicon (Si) substrates was established with an intermediate silicon nitride (SiN(x)) layer that can be etched with a much larger selectivity against the imprint resist than the Si substrate. The 2.5D resist profiles are thus transferred back into binary structures in the SiN(x) layer and subsequently into the Si substrate. A substantial size reduction of the diameter of pits from 91 to 33 nm and the width of lines from 600 to 142 nm was achieved. PMID:22469617

  7. Cerebral complexity preceded enlarged brain size and reduced olfactory bulbs in Old World monkeys

    PubMed Central

    Gonzales, Lauren A.; Benefit, Brenda R.; McCrossin, Monte L.; Spoor, Fred

    2015-01-01

    Analysis of the only complete early cercopithecoid (Old World monkey) endocast currently known, that of 15-million-year (Myr)-old Victoriapithecus, reveals an unexpectedly small endocranial volume (ECV) relative to body size and a large olfactory bulb volume relative to ECV, similar to extant lemurs and Oligocene anthropoids. However, the Victoriapithecus brain has principal and arcuate sulci of the frontal lobe not seen in the stem catarrhine Aegyptopithecus, as well as a distinctive cercopithecoid pattern of gyrification, indicating that cerebral complexity preceded encephalization in cercopithecoids. Since larger ECVs, expanded frontal lobes, and reduced olfactory bulbs are already present in the 17- to 18-Myr-old ape Proconsul these features evolved independently in hominoids (apes) and cercopithecoids and much earlier in the former. Moreover, the order of encephalization and brain reorganization was apparently different in hominoids and cercopithecoids, showing that brain size and cerebral organization evolve independently. PMID:26138795

  8. Transient response in longitudinal grain size to reduced gravel supply in a large river

    NASA Astrophysics Data System (ADS)

    Singer, Michael Bliss

    2010-09-01

    The first extensive dataset on subaqueous bed material grain size in a large river subject to reduced sediment supply is investigated alongside bathymetry, modeled flow, and sediment flux. Results suggest that following sediment supply decline and a shift to a finer sediment supply, the gravel-sand transition (GST) in fluvial systems extends and subsequently migrates upstream. The non-abrupt (˜125 km) GST in the Sacramento River corresponds with a hump in the long profile, indicating recent downstream redistribution of sediment that impacts grain sizes. The hump is composed of sediments winnowed from upstream gravel beds that accumulate downstream where slope declines. This increases local sorting values and coarse sediment flux rates in the GST, leading to further gravel loss by burial and net efflux. Thus, in a transient response to sediment supply changes, whether anthropogenic or natural, the GST extends upstream as a longitudinally patchy bed modulated by bedload sheet transport that favors the loss of gravel.

  9. Transient response in longitudinal grain size to reduced gravel supply in a large river

    NASA Astrophysics Data System (ADS)

    Singer, M. B.

    2010-12-01

    The first extensive dataset on subaqueous bed material grain size in a large river subject to reduced sediment supply is investigated alongside bathymetry, modeled flow, and sediment flux. Results suggest that following sediment supply decline and a shift to a finer sediment supply, the gravel-sand transition (GST) in fluvial systems extends and subsequently migrates upstream. The non-abrupt (~125 km) GST in the Sacramento River corresponds with a hump in the long profile, indicating recent downstream redistribution of sediment that impacts grain sizes. The hump is composed of sediments winnowed from upstream gravel beds that accumulate downstream where slope declines. This increases local sorting values and coarse sediment flux rates in the GST, leading to further gravel loss by burial and net efflux. Thus, in a transient response to sediment supply changes, whether anthropogenic or natural, the GST extends upstream as a longitudinally patchy bed modulated by bedload sheet transport that favors the loss of gravel.

  10. Anisotropic remastering for reducing feature sizes on UV nanoimprint lithography replica molds

    NASA Astrophysics Data System (ADS)

    Lausecker, E.; Grydlik, M.; Brehm, M.; Bergmair, I.; Mühlberger, M.; Fromherz, T.; Bauer, G.

    2012-04-01

    We present an approach that uses existing nanoimprint molds and reduces the size of the resulting features significantly via a remastering process utilizing the anisotropic etchant tetramethylammonium hydroxide and a mold casting step. Inverted pyramidal structures and V-grooves were imprinted using these 2.5-dimensional (2.5D) replica molds. Pattern transfer into silicon (Si) substrates was established with an intermediate silicon nitride (SiNx) layer that can be etched with a much larger selectivity against the imprint resist than the Si substrate. The 2.5D resist profiles are thus transferred back into binary structures in the SiNx layer and subsequently into the Si substrate. A substantial size reduction of the diameter of pits from 91 to 33 nm and the width of lines from 600 to 142 nm was achieved.

  11. The Role of Social Norms in the Portion Size Effect: Reducing Normative Relevance Reduces the Effect of Portion Size on Consumption Decisions.

    PubMed

    Versluis, Iris; Papies, Esther K

    2016-01-01

    People typically eat more from large portions of food than from small portions. An explanation that has often been given for this so-called portion size effect is that the portion size acts as a social norm and as such communicates how much is appropriate to eat. In this paper, we tested this explanation by examining whether manipulating the relevance of the portion size as a social norm changes the portion size effect, as assessed by prospective consumption decisions. We conducted one pilot experiment and one full experiment in which participants respectively indicated how much they would eat or serve themselves from a given amount of different foods. In the pilot (N = 63), we manipulated normative relevance by allegedly basing the portion size on the behavior of either students of the own university (in-group) or of another university (out-group). In the main experiment (N = 321), we told participants that either a minority or majority of people similar to them approved of the portion size. Results show that in both experiments, participants expected to serve themselves and to eat more from larger than from smaller portions. As expected, however, the portion size effect was less pronounced when the reference portions were allegedly based on the behavior of an out-group (pilot) or approved only by a minority (main experiment). These findings suggest that the portion size indeed provides normative information, because participants were less influenced by it if it communicated the behaviors or values of a less relevant social group. In addition, in the main experiment, the relation between portion size and the expected amount served was partially mediated by the amount that was considered appropriate, suggesting that concerns about eating an appropriate amount indeed play a role in the portion size effect. However, since the portion size effect was weakened but not eliminated by the normative relevance manipulations and since mediation was only partial, other

  12. The Role of Social Norms in the Portion Size Effect: Reducing Normative Relevance Reduces the Effect of Portion Size on Consumption Decisions

    PubMed Central

    Versluis, Iris; Papies, Esther K.

    2016-01-01

    People typically eat more from large portions of food than from small portions. An explanation that has often been given for this so-called portion size effect is that the portion size acts as a social norm and as such communicates how much is appropriate to eat. In this paper, we tested this explanation by examining whether manipulating the relevance of the portion size as a social norm changes the portion size effect, as assessed by prospective consumption decisions. We conducted one pilot experiment and one full experiment in which participants respectively indicated how much they would eat or serve themselves from a given amount of different foods. In the pilot (N = 63), we manipulated normative relevance by allegedly basing the portion size on the behavior of either students of the own university (in-group) or of another university (out-group). In the main experiment (N = 321), we told participants that either a minority or majority of people similar to them approved of the portion size. Results show that in both experiments, participants expected to serve themselves and to eat more from larger than from smaller portions. As expected, however, the portion size effect was less pronounced when the reference portions were allegedly based on the behavior of an out-group (pilot) or approved only by a minority (main experiment). These findings suggest that the portion size indeed provides normative information, because participants were less influenced by it if it communicated the behaviors or values of a less relevant social group. In addition, in the main experiment, the relation between portion size and the expected amount served was partially mediated by the amount that was considered appropriate, suggesting that concerns about eating an appropriate amount indeed play a role in the portion size effect. However, since the portion size effect was weakened but not eliminated by the normative relevance manipulations and since mediation was only partial, other

  13. Radiation damage in protein crystals is reduced with a micron-sized X-ray beam

    PubMed Central

    Sanishvili, Ruslan; Yoder, Derek W.; Pothineni, Sudhir Babu; Rosenbaum, Gerd; Xu, Shenglan; Vogt, Stefan; Stepanov, Sergey; Makarov, Oleg A.; Corcoran, Stephen; Benn, Richard; Nagarajan, Venugopalan; Smith, Janet L.; Fischetti, Robert F.

    2011-01-01

    Radiation damage is a major limitation in crystallography of biological macromolecules, even for cryocooled samples, and is particularly acute in microdiffraction. For the X-ray energies most commonly used for protein crystallography at synchrotron sources, photoelectrons are the predominant source of radiation damage. If the beam size is small relative to the photoelectron path length, then the photoelectron may escape the beam footprint, resulting in less damage in the illuminated volume. Thus, it may be possible to exploit this phenomenon to reduce radiation-induced damage during data measurement for techniques such as diffraction, spectroscopy, and imaging that use X-rays to probe both crystalline and noncrystalline biological samples. In a systematic and direct experimental demonstration of reduced radiation damage in protein crystals with small beams, damage was measured as a function of micron-sized X-ray beams of decreasing dimensions. The damage rate normalized for dose was reduced by a factor of three from the largest (15.6 μm) to the smallest (0.84 μm) X-ray beam used. Radiation-induced damage to protein crystals was also mapped parallel and perpendicular to the polarization direction of an incident 1-μm X-ray beam. Damage was greatest at the beam center and decreased monotonically to zero at a distance of about 4 μm, establishing the range of photoelectrons. The observed damage is less anisotropic than photoelectron emission probability, consistent with photoelectron trajectory simulations. These experimental results provide the basis for data collection protocols to mitigate with micron-sized X-ray beams the effects of radiation damage. PMID:21444772

  14. Protective role of normothermic machine perfusion during reduced-size liver transplantation in pigs.

    PubMed

    Zhang, Zhi-Bin; Gao, Wei; Shi, Yuan; Liu, Lei; Ma, Ning; Chen, Jing; Zhu, Zhi-Jun

    2016-07-01

    The purpose of this study is to explore whether normothermic machine perfusion (NMP) preservation is superior to cold preservation during reduced-size liver transplantation (RSLT) in pigs. Twenty-four healthy Ba-Ma mini pigs were used (aged >13 months; weight 25-35 kg; regardless of sex). The animals were randomized into 2 groups. In group A (NMP), donor livers were harvested without warm ischemia time and heartbeats and then were connected to the NMP system to reduce the livers' size under the normothermic condition. In group B (University of Wisconsin [UW] solution), donor livers were harvested without warm ischemia time and heartbeats after being perfused by UW solution and were then preserved in 0°C-4°C UW solution to reduce the livers' size under cold conditions. After that, liver transplantation without venovenous bypass was performed. General RSLT information of the pigs from the 2 groups was recorded; the serological indices were measured; and routine pathological examination of liver tissue was observed. A significant difference was observed in the intraoperative bleeding between the 2 groups (P < 0.05), whereas no significant difference was found in the other indices (all P > 0.05). Significant differences of alanine aminotransferase levels, aspartate aminotransferase levels, and lactate dehydrogenase levels between the 2 groups were observed between postoperative days 3 and 5 (P < 0.05). Significant differences of lactic acid levels between the 2 groups were observed between postoperative days 2 and 5 (P < 0.05). Compared with the cold preservation group, the liver tissues of the NMP preservation group only rarely experienced liver cell necrosis and maintained integrities in the hepatic sinusoid spaces and endothelial cells. In conclusion, NMP preservation is superior to cold preservation during RSLT in pigs. Liver Transplantation 22 968-978 2016 AASLD. PMID:27037634

  15. Extracellular Thiol Isomerases and Their Role in Thrombus Formation

    PubMed Central

    Schulman, Sol; Bendapudi, Pavan; Sharda, Anish; Chen, Vivien; Bellido-Martin, Lola; Jasuja, Reema; Furie, Barbara C.; Flaumenhaft, Robert

    2016-01-01

    Abstract Significance: The mammalian endoplasmic reticulum (ER) houses a large family of twenty thioredoxin-like proteins of which protein disulfide isomerase (PDI) is the archetypal member. Although the PDI family is best known for its role in oxidative protein folding of secretory proteins in the ER, these thioredoxin-like proteins fulfill ever-expanding roles, both within the secretory pathway and beyond. Recent Advances: Secreted PDI family proteins have now been shown to serve a critical role in platelet thrombus formation and fibrin generation. Utilizing intravital microscopy to visualize thrombus formation in mice, we have demonstrated the presence of extracellular PDI antigen during thrombus formation following injury of the vascular wall. Inhibition of PDI abrogates thrombus formation in vivo (16, 26, 46, 55). These observations have been extended to other PDI family members, including ERp57 (39, 116, 118, 123) and ERp5 (77). The vascular thiol isomerases are those PDI family members secreted from platelets and/or endothelium (40): PDI, ERp57, ERp5, ERp72, ERp44, ERp29, and TMX3. We focus here on PDI (16, 46, 55), ERp57 (39, 116, 118, 123), and ERp5 (77), which have been implicated in thrombus formation in vivo. Critical Issues: It would appear that a system of thiol isomerase redox catalysts has been hijacked from the ER to regulate thrombus formation in the vasculature. Future Directions: How this redox system is trafficked to and regulated at the cell surface, the identity of extracellular substrates, why so many thiol isomerases are required, and which thiol isomerase functions are necessary are critical unanswered questions in understanding the role of thiol isomerases in thrombus formation. Antioxid. Redox Signal. 24, 1–15. PMID:26467859

  16. Irradiation testing of full-sized, reduced-enrichment fuel elements

    SciTech Connect

    Snelgrove, J.L.; Copeland, G.L.

    1983-01-01

    The current status of the irradiation testing of full-sized, reduced-enrichment fuel elements and fuel rods under the US Reduced Enrichment Research and Test Reactor Program is reported. Being tested are UAl/sub x/-Al, U/sub 3/O/sub 8/-Al, U/sub 3/Si/sub 2/-Al, and U/sub 3/Si-Al dispersion fuels and UZrH/sub x/ (TRIGA) fuel at uranium densities in the fuel meat ranging from 1.7 to 6.0 Mg/m/sup 3/. Generally good performance has been experienced to date. Some preliminary results of postirradiation examinations are also included. A whole-core demonstration in the Oak Ridge Research Reactor is planned. Some details of this demonstration are provided.

  17. REDUCED CHLOROPLAST COVERAGE genes from Arabidopsis thaliana help to establish the size of the chloroplast compartment

    PubMed Central

    Larkin, Robert M.; Stefano, Giovanni; Ruckle, Michael E.; Stavoe, Andrea K.; Sinkler, Christopher A.; Brandizzi, Federica; Malmstrom, Carolyn M.; Osteryoung, Katherine W.

    2016-01-01

    Eukaryotic cells require mechanisms to establish the proportion of cellular volume devoted to particular organelles. These mechanisms are poorly understood. From a screen for plastid-to-nucleus signaling mutants in Arabidopsis thaliana, we cloned a mutant allele of a gene that encodes a protein of unknown function that is homologous to two other Arabidopsis genes of unknown function and to FRIENDLY, which was previously shown to promote the normal distribution of mitochondria in Arabidopsis. In contrast to FRIENDLY, these three homologs of FRIENDLY are found only in photosynthetic organisms. Based on these data, we proposed that FRIENDLY expanded into a small gene family to help regulate the energy metabolism of cells that contain both mitochondria and chloroplasts. Indeed, we found that knocking out these genes caused a number of chloroplast phenotypes, including a reduction in the proportion of cellular volume devoted to chloroplasts to 50% of wild type. Thus, we refer to these genes as REDUCED CHLOROPLAST COVERAGE (REC). The size of the chloroplast compartment was reduced most in rec1 mutants. The REC1 protein accumulated in the cytosol and the nucleus. REC1 was excluded from the nucleus when plants were treated with amitrole, which inhibits cell expansion and chloroplast function. We conclude that REC1 is an extraplastidic protein that helps to establish the size of the chloroplast compartment, and that signals derived from cell expansion or chloroplasts may regulate REC1. PMID:26862170

  18. Insulin Resistance in Human iPS Cells Reduces Mitochondrial Size and Function

    PubMed Central

    Burkart, Alison M.; Tan, Kelly; Warren, Laura; Iovino, Salvatore; Hughes, Katelyn J.; Kahn, C. Ronald; Patti, Mary-Elizabeth

    2016-01-01

    Insulin resistance, a critical component of type 2 diabetes (T2D), precedes and predicts T2D onset. T2D is also associated with mitochondrial dysfunction. To define the cause-effect relationship between insulin resistance and mitochondrial dysfunction, we compared mitochondrial metabolism in induced pluripotent stem cells (iPSC) from 5 healthy individuals and 4 patients with genetic insulin resistance due to insulin receptor mutations. Insulin-resistant iPSC had increased mitochondrial number and decreased mitochondrial size. Mitochondrial oxidative function was impaired, with decreased citrate synthase activity and spare respiratory capacity. Simultaneously, expression of multiple glycolytic enzymes was decreased, while lactate production increased 80%. These perturbations were accompanied by an increase in ADP/ATP ratio and 3-fold increase in AMPK activity, indicating energetic stress. Insulin-resistant iPSC also showed reduced catalase activity and increased susceptibility to oxidative stress. Thus, insulin resistance can lead to mitochondrial dysfunction with reduced mitochondrial size, oxidative activity, and energy production. PMID:26948272

  19. Optical Film for LED with Triangular-Pyramidal Array Using Size-Reducible Embossing Method

    NASA Astrophysics Data System (ADS)

    Liu, C. F.; Pan, C. T.; Liu, K. H.; Chen, Y. C.; Chen, J. L.; Huang, J. C.

    2011-12-01

    This study presents a modified hot-embossing process to fabricate micro-triangular-pyramidal array (MTPA). First, a tungsten (W) steel mold (as the first mold) is manufactured by precision machining including optical projection grinding, lapping, and polishing processes. The dimension of a triangular pyramid with acute angle of 85° on the W-steel mold is about 300 μm in width and 139 μm in height. The pitch between two triangular-pyramidal tips is about 170 μm. Then, only the portion of the tip area of the triangular-pyramidal patterns is transferred on bulk metallic glass (BMG, Mg58Cu31Y11) using this modified multi-step hot-embossing method to reduce the pattern size. With a position-adjustable mechanism, size-reduced concaved-shaped MTPA can be selectively formed, used as the secondary mold. In this way, not only can the size of triangular-pyramidal patterns on W-steel mold be reduced down on BMG, but also the tool arc between each triangular-pyramid on W-steel mold caused by machine tool can be eliminated. This is based on the fact that amorphous glass alloys contain no dislocation that can be responsible for yielding in crystalline materials. Thus, BMG is expected to be strong and hard enough to be used as a mold material. Then the secondary mold is used to emboss convex-shaped MTPA on PolymethylMethacrylate (PMMA) optical film. Experiments with different embossing times and embossing pressures are conducted and discussed. Large-sized triangular-pyramidal array on the W-steel mold has been successfully and selectively miniaturized on BMG, and then transferred on PMMA. Finally, this optical film of PMMA with MTPA is packaged on light-emitting diode (LED) to improve its lighting uniformity and luminance. In comparison with commercial 3M™ optical film (3M™ Vikuiti™ TBEF2-T-65i), the film with MTPA shows a good optical performance.

  20. Experimentally increased badge size increases male competition and reduces male parental care in the collared flycatcher

    PubMed Central

    Qvarnstroöm, A.

    1997-01-01

    Experimental enlargement of sexually selected traits that are energetically cheap to produce is expected to reveal costs resulting from increased risk of predation or social competition. Given a trade-off between sexually selected traits and life history traits such costs may be expected to affect not only the males themselves but also their offspring. In this study I manipulated the size of the forehead patch, a sexually selected trait that functions as a badge of status in male collared flycatchersFicedula albicollis). First, I found that a male's likelihood to establish a breeding territory with respect to his original badge size was affected by the treatment such that old males (older than or equal to two years) with relatively small original badges enjoyed an increased likelihood of establishing a breeding territory while young males (yearlings) suffered a reduced likelihood of establishment when their badges were enlarged as compared to unchanged. Second, young males with enlarged badges that were able to establish a territory fed their nestlings less in relation to their females compared to the control males. However, the females adjusted their parental effort to such an extent that no significant differences were observed in total feeding rate nor in reproductive success between the two groups of males. These results suggest that experimentally enlarged badge size in the collared flycatcher may result in increased male competition and that males have to trade their effort spent in male contest against their parental effort.

  1. Thrombus Degradation by Fibrinolytic Enzyme of Stenotrophomonas sp. Originated from Indonesian Soybean-Based Fermented Food on Wistar Rats

    PubMed Central

    Tjandrawinata, Raymond R.

    2016-01-01

    Objective. To evaluate thrombus degrading effect of a fibrinolytic enzyme from food origin Stenotrophomonas sp. of Indonesia. Methods. Prior to animal study, the enzyme safety was tested using cell culture. The effect on expression of tissue plasminogen activator was also analysed in the cell culture. For in vivo studies, 25 Wistar rats were used: normal control, negative control, treatment groups with crude and semipurified enzyme given orally at 25 mg/kg, and positive control group which received Lumbrokinase at 25 mg/kg. Blood clot in the tail was induced by kappa carrageenan injection at 1 mg/kg BW. Results. Experiment with cell culture confirmed the enzyme safety at the concentration used and increased expression of tPA. Decreasing of thrombus was observed in the positive group down to 70.35 ± 23.11% of the negative control animals (100%). The thrombus observed in the crude enzyme treatment was down to 56.99 ± 15.95% and 71.5 ± 15.7% for semipurified enzyme. Scanning electron microscopy showed clearly that bood clots were found in the animals injected with kappa carrageenan; however, in the treatment and positive groups, the clot was much reduced. Conclusions. Oral treatment of enzyme from Stenotrophomonas sp. of Indonesian fermented food was capable of degrading thrombus induced in Wistar rats.

  2. Left ventricular apical thrombus after systemic thrombolysis with recombinant tissue plasminogen activator in a patient with acute ischemic stroke

    PubMed Central

    Doepp, Florian; Sanad, Wasiem; Schreiber, Stephan J; Baumann, Gert; Borges, Adrian C

    2005-01-01

    Background Thrombolysis with recombinant tissue plasminogen activator (rtPA) is an established treatment in acute stroke. To prevent rethrombosis after rtPA therapy, secondary anticoagulation with heparin is commonly performed. However, the recommended time-point and extent of heparin treatment vary and are not well investigated. Case presentation We report a 61-year-old man who developed an acute global aphasia and right-sided hemiparesis. Cranial CT was normal and systemic thrombolytic therapy with tPA was started 120 minutes after symptom onset. Low-dose subcutaneous heparin treatment was initiated 24 hours later. Transthoracic echocardiography (TTE) 12 hours after admission showed slightly reduced left ventricular ejection fraction (LVEF) but was otherwise normal. 48 hours later the patient suddenly deteriorated with clinical signs of dyspnea and tachycardia. TTE revelead a large left ventricular apical thrombus as well as a reduction of LVEF to 20 %. Serial further TTE investigations demonstrated a complete resolution of the thrombus and normalisation of LVEF within two days. Conclusion Our case demonstrates an intracardiac thrombus formation following rtPA treatment of acute stroke, probably caused by secondary hypercoagulability. Rethrombosis or new thrombus formation might be an underestimated complication of rtPA therapy and potentially explain cases of secondary stroke progression. PMID:15918893

  3. A Novel Mechanical Thrombectomy Device for Retrieval of Intravascular Thrombus

    SciTech Connect

    Monsky, Wayne L.; Finitsis, Stephanos; Cicco, Dino De; Brock, John M.; Kucharczyk, John; Latchaw, Richard E.

    2011-04-15

    Purpose: Thrombotic and embolic vascular occlusion represents a leading cause of morbidity and mortality. Currently available thrombectomy devices have limitations, including difficulty removing organized thrombus and clot fragmentation with distal embolization. A novel mechanical thrombectomy device (MTD), designed to remove both hard and soft thrombus without trauma to the blood vessel, was tested in preclinical porcine models evaluating efficacy, safety, and ease of use. Materials and Methods: A total of 26 vessels in 14 pigs underwent mechanical thrombectomy with MTD. Thrombectomy was performed in nine superficial femoral arteries, eight subclavian arteries, five primary branches of the subclavian artery, lateral thoracic artery or the thyrocervical trunk, and four external carotids. Subacute organized fibrin-laden thrombus was injected into the arteries producing vascular occlusion. The MTD was then used for thrombectomy to restore patency and blood flow. Results: Intact thrombus was retrieved from 24 of 26 of the vessels with a single pass of the MTD, resulting in complete restoration of patency in 21 vessels and partial patency in 4 vessels. In 8 cases that used an early design, the embolic material fragmented during withdrawal from the access sheath. In 4 procedures that used an early design, the MTD failed to deploy fully and the embolus was not completely captured. No intraprocedural complications or vascular damage occurred. Conclusions: The present pilot studies demonstrate basic safety and efficacy of a novel MTD with design attributes suitable for retrieval of intact acute and organized chronic thrombus. The device has potential intracranial and peripheral utility.

  4. A microstructurally inspired damage model for early venous thrombus.

    PubMed

    Rausch, Manuel K; Humphrey, Jay D

    2015-03-01

    Accumulative damage may be an important contributor to many cases of thrombotic disease progression. Thus, a complete understanding of the pathological role of thrombus requires an understanding of its mechanics and in particular mechanical consequences of damage. In the current study, we introduce a novel microstructurally inspired constitutive model for thrombus that considers a non-uniform distribution of microstructural fibers at various crimp levels and employs one of the distribution parameters to incorporate stretch-driven damage on the microscopic level. To demonstrate its ability to represent the mechanical behavior of thrombus, including a recently reported Mullins type damage phenomenon, we fit our model to uniaxial tensile test data of early venous thrombus. Our model shows an agreement with these data comparable to previous models for damage in elastomers with the added advantages of a microstructural basis and fewer model parameters. We submit that our novel approach marks another important step toward modeling the evolving mechanics of intraluminal thrombus, specifically its damage, and hope it will aid in the study of physiological and pathological thrombotic events. PMID:26523784

  5. Atrial Thrombus in a Neonate: A Diagnostic Challenge.

    PubMed

    Sheen, Alicia; De Oliveira, Elizabeth R; Kim, Richard W; Parham, David; Lakshmanan, Ashwini

    2015-04-01

    Introduction Left atrial thrombus is a rare finding in a neonate. In the previous literature, atrial thrombi have been associated with catheter placement or congenital heart disease in a preterm infant. Case We report the case of a full-term neonate with no known risk factors found to have a left atrial thrombus. The neonate was born at 38 weeks' gestation to a 31-year-old female via cesarean section who was sent to the normal nursery. On postnatal day 5, the infant was noted to have low-to-medium level of oxygen saturations (∼90%) and was transferred to the neonatal intensive care unit with an echocardiogram completed on postnatal day 6 demonstrating a mobile, pedunculated mass attached to the left atrial septum with an appearance concerning for atrial myxoma. The infant underwent surgical resection on postnatal day 8 and pathology revealed the mass to be a left atrial thrombus. Discussion The rare finding of an atrial thrombus in a neonate has previously been associated with central venous catheter placement or congenital heart disease. This case is unusual in that the patient had neither condition. Although echocardiogram findings appeared more consistent with atrial myxoma, final pathology revealed a left atrial thrombus. Additionally, hypercoagulability work-up for this neonate was largely negative. This report underscores the importance of identification, search for etiology, and prompt therapy to prevent potential catastrophic outcomes. PMID:26199791

  6. Effects of Dabigatran on the Resolution of Left Ventricular Thrombus after Acute Myocardial Infarction.

    PubMed

    Ohashi, Norihiko; Okada, Takenori; Uchida, Mio; Amioka, Michitaka; Fujiwara, Mai; Kaseda, Shunichi

    2015-01-01

    Left ventricular thrombus (LVT) after acute myocardial infarction (AMI) is a risk factor for embolic complications. Although warfarin has traditionally been used to treat LVT, it has relevant disadvantages that limit its use. We herein describe the case of a 78-year-old man with AMI who had a history of paroxysmal atrial fibrillation. Following 10 days of urgent coronary reperfusion therapy, transthoracic echocardiography revealed a moderately sized LVT in the apex, which subsequently disappeared after 18 days of treatment with dabigatran. This case demonstrates that dabigatran may represent an alternative to warfarin as a therapeutic option in patients with LVT after AMI. PMID:26179532

  7. Synthetic thrombus model for in vitro studies of laser thrombolysis

    SciTech Connect

    Hermes, R.E.; Trajkovska, K.

    1998-07-01

    Laser thrombolysis is the controlled ablation of a thrombus (blood clot) blockage in a living arterial system. Theoretical modeling of the interaction of laser light with thrombi relies on the ability to perform in vitro experiments with well characterized surrogate materials. A synthetic thrombus formulation may offer more accurate results when compared to in vivo clinical experiments. The authors describe the development of new surrogate materials based on formulations incorporating chick egg, guar gum, modified food starch, and a laser light absorbing dye. The sound speed and physical consistency of the materials were very close to porcine (arterial) and human (venous) thrombi. Photographic and videotape recordings of pulsed dye laser ablation experiments under various experimental conditions were used to evaluate the new material as compared to in vitro tests with human (venous) thrombus. The characteristics of ablation and mass removal were similar to that of real thrombi, and therefore provide a more realistic model for in vitro laser thrombolysis when compared to gelatin.

  8. Advances in our understanding of mechanisms of venous thrombus resolution.

    PubMed

    Altmann, Johanna; Sharma, Smriti; Lang, Irene M

    2016-01-01

    Traditionally, venous thrombosis has been seen as the consequence of a regulated cascade of proteolytic steps leading to the polymerization of fibrinogen and fibrin crosslinking that is facilitated by platelets. A new view of thrombosis is providing a more integrated concept, with components of the vascular wall contributing to the vascular remodeling of thrombosis. Angiogenesis and inflammation are two key mechanisms that safeguard venous thrombus resolution and restitution of vascular patency after thrombosis. Disturbance of these processes leads to thrombus persistence and has potentially severe consequences for affected patients. Examples for clinical conditions associated with recurrent or persisting venous thrombosis are post-thrombotic syndrome or chronic thromboembolic pulmonary hypertension. Recently, studies using animal models of venous thrombosis have contributed to a better understanding of thrombus non-resolution that will eventually lead to modification of current treatment concepts. For example, recent data suggest that innate immunity is involved in the modification of thrombosis. PMID:26629617

  9. Coronary thrombus detected by cardiac CT angiography before cardiac catheterization.

    PubMed

    Slim, Ahmad M; Slim, Jennifer N; Haney, Brian R; Shry, Eric A

    2010-11-01

    A patient presented with a complaint of pleuritic chest discomfort with elevated cardiac biomarkers. After a cardiac magnetic resonance imaging scan for the suspicion of myopericarditis showed a potential myocardial infarct, a coronary CT scan was performed. This revealed a thrombus of the left anterior descending artery. Cardiac catheterization confirmed the findings, and a small clot was removed. To our knowledge, this is the first reported case of coronary thrombus being detected by CT angiography with cardiac catheterization correlation. Coronary CT angiography has been increasingly used to evaluate acute chest pain with a negative predictive value close to 100%. In a young patient with suspicion of myopericarditis, CT angiography proved to be useful in diagnosing thrombus in the coronary tree. PMID:20463613

  10. Traversing boundaries: thrombus in transit with paradoxical embolism.

    PubMed

    Miriyala, Varun; Awan, Muhammad Umer; Faraj, Kirmanj; Nagra, Bipinpreet

    2016-01-01

    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. PMID:27609716

  11. Epigenetic upregulation of endogenous VEGF-A reduces myocardial infarct size in mice.

    PubMed

    Turunen, Mikko P; Husso, Tiia; Musthafa, Haja; Laidinen, Svetlana; Dragneva, Galina; Laham-Karam, Nihay; Honkanen, Sanna; Paakinaho, Anne; Laakkonen, Johanna P; Gao, Erhe; Vihinen-Ranta, Maija; Liimatainen, Timo; Ylä-Herttuala, Seppo

    2014-01-01

    "Epigenetherapy" alters epigenetic status of the targeted chromatin and modifies expression of the endogenous therapeutic gene. In this study we used lentiviral in vivo delivery of small hairpin RNA (shRNA) into hearts in a murine infarction model. shRNA complementary to the promoter of vascular endothelial growth factor (VEGF-A) was able to upregulate endogenous VEGF-A expression. Histological and multiphoton microscope analysis confirmed the therapeutic effect in the transduced hearts. Magnetic resonance imaging (MRI) showed in vivo that the infarct size was significantly reduced in the treatment group 14 days after the epigenetherapy. Importantly, we show that promoter-targeted shRNA upregulates all isoforms of endogenous VEGF-A and that an intact hairpin structure is required for the shRNA activity. In conclusion, regulation of gene expression at the promoter level is a promising new treatment strategy for myocardial infarction and also potentially useful for the upregulation of other endogenous genes. PMID:24587164

  12. CTRP3 deficiency reduces liver size and alters IL-6 and TGFβ levels in obese mice.

    PubMed

    Wolf, Risa M; Lei, Xia; Yang, Zhi-Chun; Nyandjo, Maeva; Tan, Stefanie Y; Wong, G William

    2016-03-01

    C1q/TNF-related protein 3 (CTRP3) is a secreted metabolic regulator whose circulating levels are reduced in human and rodent models of obesity and diabetes. Previously, we showed that CTRP3 infusion lowers blood glucose by suppressing gluconeogenesis and that transgenic overexpression of CTRP3 protects mice against diet-induced hepatic steatosis. Here, we used a genetic loss-of-function mouse model to further address whether CTRP3 is indeed required for metabolic homeostasis under normal and obese states. Both male and female mice lacking CTRP3 had similar weight gain when fed a control low-fat (LFD) or high-fat diet (HFD). Regardless of diet, no differences were observed in adiposity, food intake, metabolic rate, energy expenditure, or physical activity levels between wild-type (WT) and Ctrp3-knockout (KO) animals of either sex. Contrary to expectations, loss of CTRP3 in LFD- or HFD-fed male and female mice also had minimal or no impact on whole body glucose metabolism, insulin sensitivity, and fasting-induced hepatic gluconeogenesis. Unexpectedly, the liver sizes of HFD-fed Ctrp3-KO male mice were markedly reduced despite a modest increase in triglyceride content. Furthermore, liver expression of fat oxidation genes was upregulated in the Ctrp3-KO mice. Whereas the liver and adipose expression of profibrotic TGFβ1, as well as its serum levels, was suppressed in HFD-fed KO mice, circulating proinflammatory IL-6 levels were markedly increased; these changes, however, were insufficient to affect systemic metabolic outcome. We conclude that, although it is dispensable for physiological control of energy balance, CTRP3 plays a previously unsuspected role in modulating liver size and circulating cytokine levels in response to obesity. PMID:26670485

  13. Surgical management of left ventricular thrombus following severe dehydration.

    PubMed

    Tanaka, Yuki; Nie, Masaki; Yamamoto, Nobuyuki; Ohara, Kuniyoshi; Miyaji, Kagami

    2016-08-01

    We experienced a case involving a left ventricular ball-like thrombus caused by severe following a 150 mile cycling road race. The patient had lower-limb arterial obstruction due to systemic thromboembolism on admission with no significant embolism, including the cerebral arteries, were detected. Left ventricular wall motion was good with no evidence of left and right coronary artery occlusion; therefore, we performed emergency left ventricular thrombectomy. Although there are many reports of left ventricular thrombus following acute myocardial infarction, dehydration is a very rare cause. Herein, we describe the surgical and management approaches to the treatment of left ventricular thrombectomy in this case. PMID:26266631

  14. Hypothyroid cardiomyopathy complicated by a left ventricular laminar thrombus.

    PubMed

    Van Treeck, Benjamin J; Masoud, Amgad G

    2014-01-01

    Clinical hypothyroidism is the most common hormone deficiency in the United States and is found in 0.3% of the U.S. population. It is associated with characteristic symptoms that can be readily identified by a careful history and physical examination. Hypothyroidism affects many bodily systems; in particular the cardiovascular system is impacted via multiple mechanisms.3 Occasionally hypothyroidism leads to transient left ventricular systolic dysfunction, termed hypothyroid cardiomyopathy. A rare sequela of this condition is a left ventricular thrombus, which has been described in two case reports thus far. Here we report a third case of reversible hypothyroid cardiomyopathy complicated by a left ventricular laminar thrombus. PMID:25438369

  15. Gripe water as reducing and stabilizing agent for synthesis of size controlled gold nanoparticles.

    PubMed

    Kirubha, E; Palanisamy, P K

    2013-03-01

    Green synthesis techniques are emerging as more facile and eco-friendly approach for the synthesis of metal nanoparticles compared to chemical reduction methods. Herein we report a new approach to synthesize gold nanoparticles (AuNPs) using gripe water as a reducing as well as stabilizing agent. Good control over the size of the nanoparticles from 3.2 nm to 25 nm has been achieved with this method by simply varying the experimental conditions. The Surface Plasmon Resonance bands of tunable gold nanospheres with high monodispersity and polydispersity have been obtained by this technique and monitored using UV-Visible spectrum. The morphology and the size of these AuNPs are determined using High Resolution Transmission Electron Microscope (HR-TEM). X-Ray Diffraction (XRD) analysis confirms the crystalline nature and the phase of the AuNPs. The as-synthesized AuNPs exhibit good optical nonlinearity. The nonlinear optical studies have been carried out by Z-scan technique to demonstrate its optical limiting property. The threshold limit of the AuNPs is obtained at a input intensity of 30 mW. The nonlinear refractive index of the nanoparticles is in the order of 10(-9) cm2/W and the third-order nonlinearity is estimated to be 7 x 10(-5) esu. PMID:23755681

  16. Plasmid-mediated VEGF gene transfer induces cardiomyogenesis and reduces myocardial infarct size in sheep.

    PubMed

    Vera Janavel, G; Crottogini, A; Cabeza Meckert, P; Cuniberti, L; Mele, A; Papouchado, M; Fernández, N; Bercovich, A; Criscuolo, M; Melo, C; Laguens, R

    2006-08-01

    We have recently reported that in pigs with chronic myocardial ischemia heart transfection with a plasmid encoding the 165 isoform of human vascular endothelial growth factor (pVEGF165) induces an increase in the mitotic index of adult cardiomyocytes and cardiomyocyte hyperplasia. On these bases we hypothesized that VEGF gene transfer could also modify the evolution of experimental myocardial infarct. In adult sheep pVEGF165 (3.8 mg, n=7) or empty plasmid (n=7) was injected intramyocardially 1 h after coronary artery ligation. After 15 days infarct area was 11.3+/-1.3% of the left ventricle in the VEGF group and 18.2+/-2.1% in the empty plasmid group (P<0.02). The mechanisms involved in infarct size reduction (assessed in additional sheep at 7 and 10 days after infarction) included an increase in early angiogenesis and arteriogenesis, a decrease in peri-infarct fibrosis, a decrease in myofibroblast proliferation, enhanced cardiomyoblast proliferation and mitosis of adult cardiomyocytes with occasional cytokinesis. Resting myocardial perfusion (99mTc-sestamibi SPECT) was higher in VEGF-treated group than in empty plasmid group 15 days after myocardial infarction. We conclude that plasmid-mediated VEGF gene transfer reduces myocardial infarct size by a combination of effects including neovascular proliferation, modification of fibrosis and cardiomyocyte regeneration. PMID:16572192

  17. Magnetic resonance image enhancement by reducing receptors' effective size and enabling multiple channel acquisition.

    PubMed

    Yepes-Calderon, Fernando; Velasquez, Adriana; Lepore, Natasha; Beuf, Olivier

    2014-01-01

    Magnetic resonance imaging is empowered by parallel reading, which reduces acquisition time dramatically. The time saved by parallelization can be used to increase image quality or to enable specialized scanning protocols in clinical and research environments. In small animals, the sizing constraints render the use of multi-channeled approaches even more necessary, as they help to improve the typically low spatial resolution and lesser signal-to-noise ratio; however, the use of multiple channels also generates mutual induction (MI) effects that impairs imaging creation. Here, we created coils and used the shared capacitor technique to diminish first degree MI effects and pre-amplifiers to deal with higher order MI-related image deterioration. The constructed devices are tested by imaging phantoms that contain identical solutions; thus, creating the conditions for several statistical comparisons. We confirm that the shared capacitor strategy can recover the receptor capacity in compounded coils when working at the dimensions imposed by small animal imaging. Additionally, we demonstrate that the use of pre-amplifiers does not significantly reduce the quality of the images. Moreover, in light of our results, the two MI-avoiding techniques can be used together, therefore establishing the practical feasibility of flexible array coils populated with multiple loops for small animal imaging. PMID:25570478

  18. Somatostatin analogue, octreotide, reduces increased glomerular filtration rate and kidney size in insulin-dependent diabetes

    SciTech Connect

    Serri, O.; Beauregard, H.; Brazeau, P.; Abribat, T.; Lambert, J.; Harris, A.; Vachon, L. Sandoz Canada Inc., Dorval, Quebec )

    1991-02-20

    To determine whether treatment with a somatostatin analogue can reduce kidney hyperfiltration and hypertrophy in insulin-dependent diabetes mellitus, the authors studied 11 patients with insulin-dependent diabetes mellitus and glomerular hyperfiltration. The patients were assigned randomly to receive continuous subcutaneous infusion of either octreotide, 300 {mu}g/24 h (five patients) or placebo (six patients) for 12 weeks. At baseline, mean glomerular filtration rate and mean total kidney volume were not significantly different in the two groups. However, after 12 weeks of treatment, the mean glomerular filtration rate was significantly lower in the octreotide group than in the placebo group. Furthermore, the mean total kidney volume was significantly lower after treatment in the octreotide group than in the placebo group. Glycemic control did not change significantly in either group. They conclude that subcutaneous infusion of octreotide for 12 weeks reduces increased glomerular filtration rate and kidney size in patients with insulin-dependent diabetes mellitus despite the fact that glycemic control remains unchanged.

  19. Morphology, structural properties and reducibility of size-selected CeO2- x nanoparticle films.

    PubMed

    Spadaro, Maria Chiara; D'Addato, Sergio; Gasperi, Gabriele; Benedetti, Francesco; Luches, Paola; Grillo, Vincenzo; Bertoni, Giovanni; Valeri, Sergio

    2015-01-01

    Non-stoichiometric ceria nanoparticles (NPs) were obtained by a gas aggregation source with a magnetron and were mass-selected with a quadrupole mass filter. By varying magnetron power, Ar gas flow, and the length of the aggregation tube, NPs with an average diameter of 6, 9, and 14 nm were synthesized and deposited onto a substrate, thus obtaining NP films. The morphology of the films was studied with scanning electron microscopy, while high resolution transmission electron microscopy was used to gain a deeper insight into the atomic structure of individual NPs. By using X-ray photoelectron spectroscopy we analyzed the degree of reduction of the NPs of different diameters, before and after thermal treatments in vacuum (reduction cycle) and in O2 atmosphere (oxidation cycle) at different temperatures. From this analysis we inferred that the size is an important parameter only at intermediate temperatures. As a comparison, we evaluated the reducibility of an ultra-thin ceria film with the same surface to volume ratio as the 9 nm diameter NPs film, observing that NPs are more reducible than the ceria film. PMID:25671152

  20. Restaurant Owners’ Perspectives on a Voluntary Program to Recognize Restaurants for Offering Reduced-Size Portions, Los Angeles County, 2012

    PubMed Central

    Dunning, Lauren; Kuo, Tony; Simon, Paul; Fielding, Jonathan E.

    2014-01-01

    Introduction Reducing the portion size of food and beverages served at restaurants has emerged as a strategy for addressing the obesity epidemic; however, barriers and facilitators to achieving this goal are not well characterized. Methods In fall 2012, the Los Angeles County Department of Public Health conducted semistructured interviews with restaurant owners to better understand contextual factors that may impede or facilitate participation in a voluntary program to recognize restaurants for offering reduced-size portions. Results Interviews were completed with 18 restaurant owners (representing nearly 350 restaurants). Analyses of qualitative data revealed 6 themes related to portion size: 1) perceived customer demand is central to menu planning; 2) multiple portion sizes are already being offered for at least some food items; 3) numerous logistical barriers exist for offering reduced-size portions; 4) restaurant owners have concerns about potential revenue losses from offering reduced-size portions; 5) healthful eating is the responsibility of the customer; and 6) a few owners want to be socially responsible industry leaders. Conclusion A program to recognize restaurants for offering reduced-size portions may be a feasible approach in Los Angeles County. These findings may have applications for jurisdictions interested in engaging restaurants as partners in reducing the obesity epidemic. PMID:24650622

  1. Estradiol and G1 Reduce Infarct Size and Improve Immunosuppression after Experimental Stroke

    PubMed Central

    Zhang, Bing; Subramanian, Sandhya; Dziennis, Suzan; Jia, Jia; Uchida, Masayoshi; Akiyoshi, Kozaburo; Migliati, Elton; Lewis, Anne D.; Vandenbark, Arthur A.; Offner, Halina; Hurn, Patricia D.

    2011-01-01

    Reduced risk and severity of stroke in adult females is thought to depend on normal endogenous levels of estrogen, a well-known neuroprotectant and immunomodulator. In male mice, experimental stroke induces immunosuppression of the peripheral immune system, characterized by a reduction in spleen size and cell numbers and decreased cytokine and chemokine expression. However, stroke-induced immunosuppression has not been evaluated in female mice. To test the hypothesis that estradiol (E2) deficiency exacerbates immunosuppression after focal stroke in females, we evaluated the effect of middle cerebral artery occlusion on infarct size and peripheral and CNS immune responses in ovariectomized mice with or without sustained, controlled levels of 17-β–E2 administered by s.c. implant or the putative membrane estrogen receptor agonist, G1. Both E2- and G1-replacement decreased infarct volume and partially restored splenocyte numbers. Moreover, E2-replacement increased splenocyte proliferation in response to stimulation with anti-CD3/CD28 Abs and normalized aberrant mRNA expression for cytokines, chemokines, and chemokine receptors and percentage of CD4+CD25+FoxP3+ T regulatory cells observed in E2-deficient animals. These beneficial changes in peripheral immunity after E2 replacement were accompanied by a profound reduction in expression of the chemokine, MIP-2, and a 40-fold increased expression of CCR7 in the lesioned brain hemisphere. These results demonstrate for the first time that E2 replacement in ovariectomized female mice improves stroke-induced peripheral immunosuppression. PMID:20304826

  2. Handling large datasets of hyperspectral images: reducing data size without loss of useful information.

    PubMed

    Ferrari, Carlotta; Foca, Giorgia; Ulrici, Alessandro

    2013-11-13

    Hyperspectral Imaging (HSI) is gaining increasing interest in the field of analytical chemistry, since this fast and non-destructive technique allows one to easily acquire a large amount of spectral and spatial information on a wide number of samples in very short times. However, the large size of hyperspectral image data often limits the possible uses of this technique, due to the difficulty of evaluating many samples altogether, for example when one needs to consider a representative number of samples for the implementation of on-line applications. In order to solve this problem, we propose a novel chemometric strategy aimed to significantly reduce the dataset size, which allows to analyze in a completely automated way from tens up to hundreds of hyperspectral images altogether, without losing neither spectral nor spatial information. The approach essentially consists in compressing each hyperspectral image into a signal, named hyperspectrogram, which is created by combining several quantities obtained by applying PCA to each single hyperspectral image. Hyperspectrograms can then be used as a compact set of descriptors and subjected to blind analysis techniques. Moreover, a further improvement of both data compression and calibration/classification performances can be achieved by applying proper variable selection methods to the hyperspectrograms. A visual evaluation of the correctness of the choices made by the algorithm can be obtained by representing the selected features back into the original image domain. Likewise, the interpretation of the chemical information underlying the selected regions of the hyperspectrograms related to the loadings is enabled by projecting them in the original spectral domain. Examples of applications of the hyperspectrogram-based approach to hyperspectral images of food samples in the NIR range (1000-1700 nm) and in the vis-NIR range (400-1000 nm), facing a calibration and a defect detection issue respectively, demonstrate the

  3. A Predictive Model of High Shear Thrombus Growth.

    PubMed

    Mehrabadi, Marmar; Casa, Lauren D C; Aidun, Cyrus K; Ku, David N

    2016-08-01

    The ability to predict the timescale of thrombotic occlusion in stenotic vessels may improve patient risk assessment for thrombotic events. In blood contacting devices, thrombosis predictions can lead to improved designs to minimize thrombotic risks. We have developed and validated a model of high shear thrombosis based on empirical correlations between thrombus growth and shear rate. A mathematical model was developed to predict the growth of thrombus based on the hemodynamic shear rate. The model predicts thrombus deposition based on initial geometric and fluid mechanic conditions, which are updated throughout the simulation to reflect the changing lumen dimensions. The model was validated by comparing predictions against actual thrombus growth in six separate in vitro experiments: stenotic glass capillary tubes (diameter = 345 µm) at three shear rates, the PFA-100(®) system, two microfluidic channel dimensions (heights = 300 and 82 µm), and a stenotic aortic graft (diameter = 5.5 mm). Comparison of the predicted occlusion times to experimental results shows excellent agreement. The model is also applied to a clinical angiography image to illustrate the time course of thrombosis in a stenotic carotid artery after plaque cap rupture. Our model can accurately predict thrombotic occlusion time over a wide range of hemodynamic conditions. PMID:26795978

  4. Flow impeding fungal thrombus in the ascending aorta.

    PubMed

    Huang, Jiapeng; Bouvette, Michael J; Hagi, Yousef; Subramanian, Sujata; Zhou, Jing; Austin, Erle H

    2008-10-01

    Mycotic endoaortitis is a rarely occurring infectious entity with an extremely high mortality rate. We report an uncommon case of Phialemonium endoaortits with its management. This large fungal thrombus in the ascending aorta caused significant impediment to the blood flow. PMID:18805204

  5. Using Ancillary Information to Reduce Sample Size in Discovery Sampling and the Effects of Measurement Error

    SciTech Connect

    Axelrod, M

    2005-08-18

    big sample size might bust the budget, or the number seems intuitively excessive. To reduce the sample size, you can increase the tolerable number of defectives, the ''10'' in the preceding example, or back off on the confidence level, say from 95% to 90%. Auditors also frequently bump up the sample size as a safety factor. They know that something can go wrong. For example, they might find out that the measurements or inspections were subject to errors. Unless the auditors know exactly how measurement error affects sample size, they might be forced to give up the safety factor. Clients often choose to ''live dangerously'' (without a compelling argument to the contrary) to save money. Thus, sometimes the auditor finds that ''you just can't get there from here'', because the goals of the audit and the resources available are inherently in conflict. For discovery audits, there is a way out of this apparent conundrum. It turns out that the classical method of confidence intervals uses an implicit and very conservative assumption. We will see that this assumption is too pessimistic and too conservative in the context of a discovery audit. If we abandon this assumption and use ancillary information about the inventory, then we can significantly reduce the sample size required to achieve the desired confidence level. We will see exactly how the classical method ignores this ancillary information and misses the opportunity for an efficient audit. In the following sections, we first review the standard approach using confidence intervals. Then we present a method that incorporates the ancillary information about the inventory to design a very efficient discovery audit. We also provide results on how measurement errors affect the audit, and how exactly how much the sample size must be modified to compensate for these errors. Finally, we state asymptotic formulas that provide useful approximations for large inventories. It is suggested that the reader review the glossary of

  6. Reduced salivary gland size and increased presence of epithelial progenitor cells in DLK1-deficient mice.

    PubMed

    García-Gallastegui, P; Luzuriaga, J; Aurrekoetxea, M; Baladrón, V; Ruiz-Hidalgo, M J; García-Ramírez, J J; Laborda, J; Unda, F; Ibarretxe, G

    2016-06-01

    DLK1 (PREF1, pG2, or FA1) is a transmembrane and secreted protein containing epidermal growth factor-like repeats. Dlk1 expression is abundant in many tissues during embryonic and fetal development and is believed to play an important role in the regulation of tissue differentiation and fetal growth. After birth, Dlk1 expression is abolished in most tissues but is possibly reactivated to regulate stem cell activation and responses to injury. We have recently reported that DLK1 regulates many aspects of salivary gland organogenesis. Here, we have extended our studies of the salivary gland phenotype of Dlk1 knock-out mice. We have observed that salivary glands are smaller and weigh significantly less in both Dlk1 knock-out males and females compared with gender and age-matched wild-type mice and regardless of the natural sexual dimorphism in rodent salivary glands. This reduced size correlates with a reduced capacity of Dlk1-deficient mice to secrete saliva after stimulation with pilocarpine. However, histological and ultrastructural analyses of both adult and developing salivary gland tissues have revealed no defects in Dlk1 ((-/-)) mice, indicating that genetic compensation accounts for the relatively mild salivary phenotype in these animals. Finally, despite their lack of severe anomalies, we have found that salivary glands from Dlk1-deficient mice present a higher amount of CK14-positive epithelial progenitors at various developmental stages, suggesting a role for DLK1 in the regulation of salivary epithelial stem cell balance. PMID:26711912

  7. Dynamic clustering threshold reduces conformer ensemble size while maintaining a biologically relevant ensemble.

    PubMed

    Yongye, Austin B; Bender, Andreas; Martínez-Mayorga, Karina

    2010-08-01

    Representing the 3D structures of ligands in virtual screenings via multi-conformer ensembles can be computationally intensive, especially for compounds with a large number of rotatable bonds. Thus, reducing the size of multi-conformer databases and the number of query conformers, while simultaneously reproducing the bioactive conformer with good accuracy, is of crucial interest. While clustering and RMSD filtering methods are employed in existing conformer generators, the novelty of this work is the inclusion of a clustering scheme (NMRCLUST) that does not require a user-defined cut-off value. This algorithm simultaneously optimizes the number and the average spread of the clusters. Here we describe and test four inter-dependent approaches for selecting computer-generated conformers, namely: OMEGA, NMRCLUST, RMS filtering and averaged-RMS filtering. The bioactive conformations of 65 selected ligands were extracted from the corresponding protein:ligand complexes from the Protein Data Bank, including eight ligands that adopted dissimilar bound conformations within different receptors. We show that NMRCLUST can be employed to further filter OMEGA-generated conformers while maintaining biological relevance of the ensemble. It was observed that NMRCLUST (containing on average 10 times fewer conformers per compound) performed nearly as well as OMEGA, and both outperformed RMS filtering and averaged-RMS filtering in terms of identifying the bioactive conformations with excellent and good matches (0.5 < RMSD < 1.0 A). Furthermore, we propose thresholds for OMEGA root-mean square filtering depending on the number of rotors in a compound: 0.8, 1.0 and 1.4 for structures with low (1-4), medium (5-9) and high (10-15) numbers of rotatable bonds, respectively. The protocol employed is general and can be applied to reduce the number of conformers in multi-conformer compound collections and alleviate the complexity of downstream data processing in virtual screening experiments

  8. From micro- to nanomagnetic dots: evolution of the eigenmode spectrum on reducing the lateral size

    NASA Astrophysics Data System (ADS)

    Carlotti, G.; Gubbiotti, G.; Madami, M.; Tacchi, S.; Hartmann, F.; Emmerling, M.; Kamp, M.; Worschech, L.

    2014-07-01

    Brillouin light scattering experiments and micromagnetic simulations have been exploited to investigate the spectrum of thermally excited magnetic eigenmodes in 10 nm-thick elliptical Permalloy dots, when the longer axis D is scaled down from about 1000 to 100 nm. It is shown that for D larger than about 200 nm the characteristics of the spin-wave eigenmodes are dominated by dipolar energy, while for D in the range of about 100 to 200 nm exchange energy effects cause qualitative and quantitative differences in the spin-wave spectrum. In this ‘mesoscopic’ regime, the usual classification scheme, involving one fundamental mode with large average magnetization and many other modes collected in families with specific symmetries, no longer holds. Rather, one finds the simultaneous presence of two modes with ‘fundamental’ character, i.e. with a significant and comparable value of the average dynamical magnetization: the former is at larger frequency and has its maximum amplitude at the dot's centre, while the latter occurs at lower frequency and is localized at the dot's edges. Interestingly, the maximum intensity swaps from the higher frequency mode to the lower frequency one, just when the dot size is reduced from about 200 to 100 nm. This is relevant in view of the exploitation of nanodots for the design of nanomagnetic devices with lateral dimensions in the above interval, such as memory cells, logic gates, reading heads and spin-torque oscillators.

  9. Flocculated sediments can reduce the size of sediment basin at construction sites.

    PubMed

    Kang, Jihoon; King, Scott E; McLaughlin, Richard A

    2016-01-15

    Due to stringent water quality regulations on stormwater discharges, there is increasing interest in chemically-assisted settling of suspended sediments at construction sites. This study investigated settling characteristics of flocculated sediment by polyacrylamide (PAM) in a top-loading settling tube. Studied sediment materials were obtained from construction sites in North Carolina, USA: Coastal Plain loamy sand (CPLS), Piedmont sandy clay loam (PSCL), Piedmont silt loam (PSL), and Mountain clay loam (MCL). The four different sediment suspensions mixed with and without dissolved PAM were introduced to the top of the column individually. During a 1-h settling period, samples were taken at 1-m depth from surface at various times and analyzed for total suspended solids (TSS). Flocculated sediment by PAM greatly increased its settled TSS fraction up to 95-97% only in 1-min settling period compared to those of unflocculated sediment (16-72%). The settling improvement by PAM was profound in the finer-textured soils (PSL and MCL) by increasing their median particle settling velocity (>2 cm s(-1)) compared to unflocculated counterparts (<1.1 cm s(-1)). Estimated surface area requirement of sediment basin suggested that the basins receiving flocculated sediment could be reduced in size (surface area) by 2- to 4-times compared to those receiving unflocculated sediment. Our results suggests that current sediment basin design could be modified when chemically-assisted settling is implemented, taking up less space and cost in construction sites. PMID:26555101

  10. Epigenetic Upregulation of Endogenous VEGF-A Reduces Myocardial Infarct Size in Mice

    PubMed Central

    Musthafa, Haja; Laidinen, Svetlana; Dragneva, Galina; Laham-Karam, Nihay; Honkanen, Sanna; Paakinaho, Anne; Laakkonen, Johanna P.; Gao, Erhe; Vihinen-Ranta, Maija; Liimatainen, Timo; Ylä-Herttuala, Seppo

    2014-01-01

    “Epigenetherapy” alters epigenetic status of the targeted chromatin and modifies expression of the endogenous therapeutic gene. In this study we used lentiviral in vivo delivery of small hairpin RNA (shRNA) into hearts in a murine infarction model. shRNA complementary to the promoter of vascular endothelial growth factor (VEGF-A) was able to upregulate endogenous VEGF-A expression. Histological and multiphoton microscope analysis confirmed the therapeutic effect in the transduced hearts. Magnetic resonance imaging (MRI) showed in vivo that the infarct size was significantly reduced in the treatment group 14 days after the epigenetherapy. Importantly, we show that promoter-targeted shRNA upregulates all isoforms of endogenous VEGF-A and that an intact hairpin structure is required for the shRNA activity. In conclusion, regulation of gene expression at the promoter level is a promising new treatment strategy for myocardial infarction and also potentially useful for the upregulation of other endogenous genes. PMID:24587164

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

    NASA Technical Reports Server (NTRS)

    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 = 2.5 (p = 0.03). All 34 patients with thrombus or mixed presentation had > or = 1 predictor. The prevalence of thrombus in the presence of < or = 1, 2, and > 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.

  12. [A case of an elderly patient having advanced hepatocellular carcinoma with tumor thrombus in the inferior vena cava treated with chemo-radio-therapy--intraarterial infusion of weekly high dose 5-FU (WHF)].

    PubMed

    Yabuuchi, Shinichi; Katayose, Yu; Rikiyama, Toshiki; Oikawa, Masaya; Yamamoto, Kuniharu; Onogawa, Toru; Hayashi, Hiroki; Muto, Mitsuhisa; Unno, Michiaki

    2006-11-01

    The patient was an 81-year-old man, diagnosed with advanced huge hepatocellular carcinoma (HCC) with tumor thrombus extending into the inferior vena cava (Vv3), for which resection was judged impossible. The radio therapy (51 Gy) for tumor thrombus was carried out, and he received a weekly hepatic arterial infusion therapy (weekly high-dose 5-fluorouracil (5-FU)) for these legions. After 8 cycles, the CT scan revealed a minor response of the tumor (SD), and,the tumor marker reduced. After 10 months, these legions had markedly regressed (PR), the tumor thrombus in the inferior vena cava was not detectable. There were no severe side effects. Ten months since the start of chemo-radio therapy, the positron emission tomography (PET) revealed a metastatic tumor of the femoral bone in recurrence. In conclusion, some elderly patients of advanced HCC with tumor thrombus may obtain a long term survival through this treatment. PMID:17212102

  13. Invasive surgery reduces infarct size and preserves cardiac function in a porcine model of myocardial infarction

    PubMed Central

    van Hout, Gerardus PJ; Teuben, Michel PJ; Heeres, Marjolein; de Maat, Steven; de Jong, Renate; Maas, Coen; Kouwenberg, Lisanne HJA; Koenderman, Leo; van Solinge, Wouter W; de Jager, Saskia CA; Pasterkamp, Gerard; Hoefer, Imo E

    2015-01-01

    Reperfusion injury following myocardial infarction (MI) increases infarct size (IS) and deteriorates cardiac function. Cardioprotective strategies in large animal MI models often failed in clinical trials, suggesting translational failure. Experimentally, MI is induced artificially and the effect of the experimental procedures may influence outcome and thus clinical applicability. The aim of this study was to investigate if invasive surgery, as in the common open chest MI model affects IS and cardiac function. Twenty female landrace pigs were subjected to MI by transluminal balloon occlusion. In 10 of 20 pigs, balloon occlusion was preceded by invasive surgery (medial sternotomy). After 72 hrs, pigs were subjected to echocardiography and Evans blue/triphenyl tetrazoliumchloride double staining to determine IS and area at risk. Quantification of IS showed a significant IS reduction in the open chest group compared to the closed chest group (IS versus area at risk: 50.9 ± 5.4% versus 69.9 ± 3.4%, P = 0.007). End systolic LV volume and LV ejection fraction measured by echocardiography at follow-up differed significantly between both groups (51 ± 5 ml versus 65 ± 3 ml, P = 0.033; 47.5 ± 2.6% versus 38.8 ± 1.2%, P = 0.005). The inflammatory response in the damaged myocardium did not differ between groups. This study indicates that invasive surgery reduces IS and preserves cardiac function in a porcine MI model. Future studies need to elucidate the effect of infarct induction technique on the efficacy of pharmacological therapies in large animal cardioprotection studies. PMID:26282710

  14. Different effects of laser contrast on proton emission from normal large foils and transverse-size-reduced targets

    NASA Astrophysics Data System (ADS)

    Fang, Yuan; Ge, Xulei; Yang, Su; Wei, Wenqing; Yu, Tongpu; Liu, Feng; Chen, Min; Liu, Jingquan; Yuan, Xiaohui; Sheng, Zhengming; Zhang, Jie

    2016-07-01

    We report experimental results on the effects of laser contrast on beam divergence and energy spectrum of protons emitted from ultrashort intense laser interactions with normal large foils and transverse-size-reduced targets. Correlations between beam divergence and spectral shape are found. Large divergence and near-plateau shape energy spectrum are observed for both types of targets when the laser pulse contrast is low. With high contrast laser irradiation, proton beam divergence is remarkably reduced and the energy spectral shape is changed to exponential for large foil targets. In comparison, a similar large divergence and the near-plateau spectral shape remain for transverse-size-reduced targets. The results could be explained by the preplasma formation and target deformation at different laser contrasts and modified accelerating sheath field evolution in transverse-size-reduced target, which were supported by the 2D hydrodynamic and PIC simulations.

  15. Reducing Class Size: A Smart Way To Improve America's Urban Schools. Second Edition.

    ERIC Educational Resources Information Center

    Naik, Manish; Casserly, Michael; Uro, Gabriela

    The Council of the Great City Schools, a coalition of the largest urban public schools in the United States, surveyed its membership to determine how they were using federal class size reduction funds in the 2000-2001 school year. Thirty-six major urban school systems responded. Results indicate that the federal class size reduction program is…

  16. Real-Time Observation of Thrombus Growth Process in an Impeller of a Hydrodynamically Levitated Centrifugal Blood Pump by Near-Infrared Hyperspectral Imaging.

    PubMed

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Fujiwara, Tatsuki; Nishida, Masahiro; Maruyama, Osamu

    2015-08-01

    Understanding the thrombus formation in cardiovascular devices such as rotary blood pumps is the most important issue in developing more hemocompatible devices. The objective of this study was to develop a hyperspectral imaging (HSI) method to visualize the thrombus growth process within a rotary blood pump and investigate the optical properties of the thrombus. An in vitro thrombogenic test was conducted using fresh porcine blood and a specially designed hydrodynamically levitated centrifugal blood pump with a transparent bottom. The pump rotating at 3000 rpm circulated the blood at 1.0 L/min. The bottom surface of the pump was illuminated with white light pulsed at the same frequency as the pump rotation, and the backward-scattered light was imaged using the HSI system. Using stroboscopic HSI and an image construction algorithm, dynamic spectral imaging at wavelengths ranging from 608 to 752 nm within the rotating pump was achieved. After completing the experiment, we collected the red thrombus formed in the pump impeller and quantified the thrombus hemoglobin concentration (Hbthrombus ). The spectrum changed around the center of the impeller, and the area of change expanded toward the impeller flow path. The shape corresponded approximately to the shape of the thrombus. The spectrum change indicated that the light scattering derived from red blood cells decreased. The Hbthrombus was 4.7 ± 1.3 g/dL versus a total hemoglobin of 13 ± 0.87 g/dL. The study revealed that Hbthrombus was reduced by the surrounding blood flow. PMID:26234451

  17. Cocaine-Induced Delayed Myocardial Infarction Complicated by Apical Thrombus.

    PubMed

    Khan, Rafay; Arshed, Sabrina; Jehangir, Waqas; Sen, Shuvendu; Yousif, Abdalla

    2016-01-01

    It is well demonstrated in the literature that cocaine use has been well linked to the formation of various forms of acute and chronic cardiovascular problems including but not limited to acute coronary syndromes. However, cocaine has been commonly associated with coronary vasospasms and less commonly with myocardial infarction and the formation of atrial thrombus. Through this case presentation, we illustrate the findings of a 35-year-old gentleman with history of cocaine use presenting with acute coronary syndrome and complicated by thrombus formation. Furthermore, through this report, we illustrate in a patient with no other risk factors and at a young age, how chronic cocaine use or even a history of usage may result in complications even weeks after its consumption. PMID:26668686

  18. Thrombus Volume Change Visualization after Endovascular Abdominal Aortic Aneurysm Repair

    NASA Astrophysics Data System (ADS)

    Maiora, Josu; García, Guillermo; Macía, Iván; Legarreta, Jon Haitz; Boto, Fernando; Paloc, Céline; Graña, Manuel; Abuín, Javier Sanchez

    A surgical technique currently used in the treatment of Abdominal Aortic Aneurysms (AAA) is the Endovascular Aneurysm Repair (EVAR). This minimally invasive procedure involves inserting a prosthesis in the aortic vessel that excludes the aneurysm from the bloodstream. The stent, once in place acts as a false lumen for the blood current to travel down, and not into the surrounding aneurysm sac. This procedure, therefore, immediately takes the pressure off the aneurysm, which thromboses itself after some time. Nevertheless, in a long term perspective, different complications such as prosthesis displacement or bloodstream leaks into or from the aneurysmatic bulge (endoleaks) could appear causing a pressure elevation and, as a result, increasing the danger of rupture. The purpose of this work is to explore the application of image registration techniques to the visual detection of changes in the thrombus in order to assess the evolution of the aneurysm. Prior to registration, both the lumen and the thrombus are segmented

  19. Cardiac Fibroelastoma versus Thrombus: Echocardiographic Evidence Can Be Misleading

    PubMed Central

    2016-01-01

    We present a case of a young female with stroke symptoms who underwent valve sparing resection of a presumed fibroelastoma based on echocardiographic findings. After confirming embolic stroke, she underwent excision of the lesion, which on pathology revealed a nonbacterial thrombus. Ultimately, this led to a more extensive work-up leading to the discovery of a papillary serous ovarian carcinoma, the underlying cause of her hypercoagulable state. The initial echocardiographic findings painted the clear picture of a papillary tumor on the aortic valve which was likely the source of the emboli resulting in ischemic stroke. This unique case presentation illustrates that imaging, including echocardiography, may not always coincide with the clinical diagnosis. Thus, understanding the differential diagnoses of cardiac masses is of vital clinical significance. The distinction of fibroelastoma versus the much less common finding of aortic thrombus may lead to early diagnosis of malignancy and prevention of life threatening events due to stroke or undiagnosed disease. PMID:27547468

  20. Coagulation activity and white thrombus formation in the microminipig.

    PubMed

    Miura, Naoki; Kawaguchi, Hiroaki; Nagasato, Tomoka; Yamada, Tomonobu; Ito, Takashi; Izumi, Hiroyuki; Shameshima, Hisayo; Miyoshi, Noriaki; Tanimoto, Akihide; Maruyama, Ikuro

    2013-01-01

    Swine are becoming increasingly attractive as animal models for clinical research and the recently developed Microminipig (MMPig) has emerged as a possible experimental animal model. In this study, we demonstrated age-dependent changes in hematological parameters and coagulation activity in healthy MMPigs (58 male and 67 females, aged 0-34 months), and investigated white thrombus formation (WTF) using an in vitro microchip flow-chamber system (four males and four females, aged 22-23 months). There was no clear sex or age-dependent differences in any hematological parameters. While activated partial thromboplastin time (APTT) was shorter than prothrombin time (PT), with APTT:PT of 0.88:1, microchip flow-chamber system analysis showed that WTF time was shorter than that in humans, suggesting a possible thrombotic tendency in the MMPig. These results could be useful to life science researchers in the use of the MMPig as an experimental model animal for thrombus formation. PMID:23606691

  1. Cocaine-Induced Delayed Myocardial Infarction Complicated by Apical Thrombus

    PubMed Central

    Khan, Rafay; Arshed, Sabrina; Jehangir, Waqas; Sen, Shuvendu; Yousif, Abdalla

    2016-01-01

    It is well demonstrated in the literature that cocaine use has been well linked to the formation of various forms of acute and chronic cardiovascular problems including but not limited to acute coronary syndromes. However, cocaine has been commonly associated with coronary vasospasms and less commonly with myocardial infarction and the formation of atrial thrombus. Through this case presentation, we illustrate the findings of a 35-year-old gentleman with history of cocaine use presenting with acute coronary syndrome and complicated by thrombus formation. Furthermore, through this report, we illustrate in a patient with no other risk factors and at a young age, how chronic cocaine use or even a history of usage may result in complications even weeks after its consumption. PMID:26668686

  2. Misshapen/NIK-related kinase (MINK1) is involved in platelet function, hemostasis, and thrombus formation.

    PubMed

    Yue, Ming; Luo, Dongjiao; Yu, Shanshan; Liu, Pu; Zhou, Qi; Hu, Mengjiao; Liu, Yangyang; Wang, Shuai; Huang, Qian; Niu, Yuxi; Lu, Linrong; Hu, Hu

    2016-02-18

    The sterile-20 kinase misshapen/Nck-interacting kinase (NIK)-related kinase 1 (MINK1) is involved in many important cellular processes such as growth, cytoskeletal rearrangement, and motility. Here, with MINK1-deficient (MINK1(-/-)) mice, we showed that MINK1 plays an important role in hemostasis and thrombosis via the regulation of platelet functions. In the tail-bleeding assay, MINK1(-/-) mice exhibited a longer bleeding time than wild-type (WT) mice (575.2 ± 59.7 seconds vs 419.6 ± 66.9 seconds). In a model of ferric chloride-induced mesenteric arteriolar thrombosis, vessel occlusion times were twice as long in MINK1(-/-) mice as in WT mice. In an in vitro microfluidic whole-blood perfusion assay, thrombus formation on a collagen matrix under arterial shear conditions was significantly reduced in MINK1(-/-) platelets. Moreover, MINK1(-/-) platelets demonstrated impaired aggregation and secretion in response to low doses of thrombin and collagen. Furthermore, platelet spreading on fibrinogen was largely hampered in MINK1(-/-) platelets. The functional differences of MINK1(-/-) platelets could be attributed to impaired adenosine 5'-diphosphate secretion. Signaling events associated with MINK1 appeared to involve extracellular signal-regulated kinase, p38, and Akt. Hence, MINK1 may be an important signaling molecule that mediates mitogen-activated protein kinase signaling and participates in platelet activation and thrombus formation. PMID:26598717

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

    PubMed Central

    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.

    2016-01-01

    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. PMID:21527521

  4. Platelet PECAM-1 inhibits thrombus formation in vivo.

    PubMed

    Falati, Shahrokh; Patil, Sonali; Gross, Peter L; Stapleton, Michelle; Merrill-Skoloff, Glenn; Barrett, Natasha E; Pixton, Katherine L; Weiler, Harmut; Cooley, Brian; Newman, Debra K; Newman, Peter J; Furie, Barbara C; Furie, Bruce; Gibbins, Jonathan M

    2006-01-15

    Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a cell surface glycoprotein receptor expressed on a range of blood cells, including platelets, and on vascular endothelial cells. PECAM-1 possesses adhesive and signaling properties, the latter being mediated by immunoreceptor tyrosine-based inhibitory motifs present on the cytoplasmic tail of the protein. Recent studies in vitro have demonstrated that PECAM-1 signaling inhibits the aggregation of platelets. In the present study we have used PECAM-1-deficient mice and radiation chimeras to investigate the function of this receptor in the regulation of thrombus formation. Using intravital microscopy and laser-induced injury to cremaster muscle arterioles, we show that thrombi formed in PECAM-1-deficient mice were larger, formed more rapidly than in control mice, and were more stable. Larger thrombi were also formed in control mice that received transplants of PECAM-1-deficient bone marrow, in comparison to mice that received control transplants. A ferric chloride model of thrombosis was used to investigate thrombus formation in carotid arteries. In PECAM-1-deficient mice the time to 75% vessel occlusion was significantly shorter than in control mice. These data provide evidence for the involvement of platelet PECAM-1 in the negative regulation of thrombus formation. PMID:16166583

  5. Tree Size Inequality Reduces Forest Productivity: An Analysis Combining Inventory Data for Ten European Species and a Light Competition Model.

    PubMed

    Bourdier, Thomas; Cordonnier, Thomas; Kunstler, Georges; Piedallu, Christian; Lagarrigues, Guillaume; Courbaud, Benoit

    2016-01-01

    Plant structural diversity is usually considered as beneficial for ecosystem functioning. For instance, numerous studies have reported positive species diversity-productivity relationships in plant communities. However, other aspects of structural diversity such as individual size inequality have been far less investigated. In forests, tree size inequality impacts directly tree growth and asymmetric competition, but consequences on forest productivity are still indeterminate. In addition, the effect of tree size inequality on productivity is likely to vary with species shade-tolerance, a key ecological characteristic controlling asymmetric competition and light resource acquisition. Using plot data from the French National Geographic Agency, we studied the response of stand productivity to size inequality for ten forest species differing in shade tolerance. We fitted a basal area stand production model that included abiotic factors, stand density, stand development stage and a tree size inequality index. Then, using a forest dynamics model we explored whether mechanisms of light interception and light use efficiency could explain the tree size inequality effect observed for three of the ten species studied. Size inequality negatively affected basal area increment for seven out of the ten species investigated. However, this effect was not related to the shade tolerance of these species. According to the model simulations, the negative tree size inequality effect could result both from reduced total stand light interception and reduced light use efficiency. Our results demonstrate that negative relationships between size inequality and productivity may be the rule in tree populations. The lack of effect of shade tolerance indicates compensatory mechanisms between effect on light availability and response to light availability. Such a pattern deserves further investigations for mixed forests where complementarity effects between species are involved. When studying the

  6. Tree Size Inequality Reduces Forest Productivity: An Analysis Combining Inventory Data for Ten European Species and a Light Competition Model

    PubMed Central

    Bourdier, Thomas; Cordonnier, Thomas; Kunstler, Georges; Piedallu, Christian; Lagarrigues, Guillaume; Courbaud, Benoit

    2016-01-01

    Plant structural diversity is usually considered as beneficial for ecosystem functioning. For instance, numerous studies have reported positive species diversity-productivity relationships in plant communities. However, other aspects of structural diversity such as individual size inequality have been far less investigated. In forests, tree size inequality impacts directly tree growth and asymmetric competition, but consequences on forest productivity are still indeterminate. In addition, the effect of tree size inequality on productivity is likely to vary with species shade-tolerance, a key ecological characteristic controlling asymmetric competition and light resource acquisition. Using plot data from the French National Geographic Agency, we studied the response of stand productivity to size inequality for ten forest species differing in shade tolerance. We fitted a basal area stand production model that included abiotic factors, stand density, stand development stage and a tree size inequality index. Then, using a forest dynamics model we explored whether mechanisms of light interception and light use efficiency could explain the tree size inequality effect observed for three of the ten species studied. Size inequality negatively affected basal area increment for seven out of the ten species investigated. However, this effect was not related to the shade tolerance of these species. According to the model simulations, the negative tree size inequality effect could result both from reduced total stand light interception and reduced light use efficiency. Our results demonstrate that negative relationships between size inequality and productivity may be the rule in tree populations. The lack of effect of shade tolerance indicates compensatory mechanisms between effect on light availability and response to light availability. Such a pattern deserves further investigations for mixed forests where complementarity effects between species are involved. When studying the

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

    SciTech Connect

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

    1997-09-15

    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.

  8. [Survival after Sorafenib Treatment for Advanced Recurrent Hepatocellular Carcinoma with Tumor Thrombus in the Inferior Vena Cava].

    PubMed

    Matoba, Hideaki; Seta, Shinsuke

    2015-11-01

    A 72-year-old man with chronic viral hepatitis type B undergoing surgery for hepatocellular carcinoma was found to have a recurrent tumor in the left liver with peritoneal dissemination near the inferior vena cava(IVC)and tumor thrombus in the IVC. For this patient diagnosed with Barcelona clinic liver cancer (BCLC) classification stage C hepatocellular carcinoma, we initiated 800 mg/body sorafenib. Two weeks after the initiation of sorafenib, the patient experienced grade 3 hand-foot syndrome, after which, the dose of sorafenib was reduced to 400 mg/body. After 1 year, CT showed an enlarged tumor in the left liver and multiple metastases to the lung. However, no remarkable difference was observed in the peritoneal dissemination and the tumor thrombus. He has been receiving sorafenib for 19 months with a good quality of life. Sorafenib can be provided on an outpatient basis and it may facilitate long-term survival for patients with advanced recurrent hepatocellular carcinoma with IVC tumor thrombus. This clinical condition is very rare, and the standard treatment for it still has not been established. PMID:26805098

  9. Reducing bias in rainfall estimates from microwave links by considering variable drop size distribution

    NASA Astrophysics Data System (ADS)

    Fencl, Martin; Jörg, Rieckermann; Vojtěch, Bareš

    2015-04-01

    Commercial microwave links (MWL) are point-to-point radio systems which are used in backhaul networks of cellular operators. For several years, they have been suggested as rainfall sensors complementary to rain gauges and weather radars, because, first, they operate at frequencies where rain drops represent significant source of attenuation and, second, cellular networks almost completely cover urban and rural areas. Usually, path-average rain rates along a MWL are retrieved from the rain-induced attenuation of received MWL signals with a simple model based on a power law relationship. The model is often parameterized based on the characteristics of a particular MWL, such as frequency, polarization and the drop size distribution (DSD) along the MWL. As information on the DSD is usually not available in operational conditions, the model parameters are usually considered constant. Unfortunately, this introduces bias into rainfall estimates from MWL. In this investigation, we propose a generic method to eliminate this bias in MWL rainfall estimates. Specifically, we search for attenuation statistics which makes it possible to classify rain events into distinct groups for which same power-law parameters can be used. The theoretical attenuation used in the analysis is calculated from DSD data using T-Matrix method. We test the validity of our approach on observations from a dedicated field experiment in Dübendorf (CH) with a 1.85-km long commercial dual-polarized microwave link transmitting at a frequency of 38 GHz, an autonomous network of 5 optical distrometers and 3 rain gauges distributed along the path of the MWL. The data is recorded at a high temporal resolution of up to 30s. It is further tested on data from an experimental catchment in Prague (CZ), where 14 MWLs, operating at 26, 32 and 38 GHz frequencies, and reference rainfall from three RGs is recorded every minute. Our results suggest that, for our purpose, rain events can be nicely characterized based on

  10. Asymptomatic large left-atrial ball thrombus. Secondary to mitral stenosis.

    PubMed Central

    Vitale, M; Agnino, A; Serena, D; Schena, S; Piscitelli, D; Fiore, T; de Luca Tupputi Schinosa, L

    1997-01-01

    We describe the very unusual case of a patient with a large, free-floating left-atrial thrombus secondary to severe mitral stenosis, in whom the peculiar symptoms and complications of a ball thrombus were absent. The patient's only symptom before the episode reported here was mild dyspnea, which was attributed to mitral stenosis. She experienced neither embolism nor syncope. While even her clinical signs did not indicate a left-atrial ball thrombus, both echocardiography and angiography showed a free-floating thrombus. Because of the risk of stroke and acute obstruction of the mitral valve, emergency surgery was performed upon diagnosis of the ball thrombus. The surgery, which consisted of removing the thrombus and replacing the mitral valve with a mechanical prosthesis, was uneventful. A computed tomographic brain scan prior to discharge did not detect any cerebral infarction. Images PMID:9456496

  11. Continuous Modeling of Arterial Platelet Thrombus Formation Using a Spatial Adsorption Equation.

    PubMed

    Babushkina, Evgenia S; Bessonov, Nikolay M; Ataullakhanov, Fazoil I; Panteleev, Mikhail A

    2015-01-01

    In this study, we considered a continuous model of platelet thrombus growth in an arteriole. A special model describing the adhesion of platelets in terms of their concentration was derived. The applications of the derived model are not restricted to only describing arterial platelet thrombus formation; the model can also be applied to other similar adhesion processes. The model reproduces an auto-wave solution in the one-dimensional case; in the two-dimensional case, in which the surrounding flow is taken into account, the typical torch-like thrombus is reproduced. The thrombus shape and the growth velocity are determined by the model parameters. We demonstrate that the model captures the main properties of the thrombus growth behavior and provides us a better understanding of which mechanisms are important in the mechanical nature of the arterial thrombus growth. PMID:26517377

  12. An Informatics Based Approach to Reduce the Grain Size of Cast Hadfield Steel

    NASA Astrophysics Data System (ADS)

    Dey, Swati; Pathak, Shankha; Sheoran, Sumit; Kela, Damodar H.; Datta, Shubhabrata

    2016-04-01

    Materials Informatics concept using computational intelligence based approaches are employed to bring out the significant alloying additions to achieve grain refinement in cast Hadfield steel. Castings of Hadfield steels used for railway crossings, requires fine grained austenitic structure. Maintaining proper grain size of this component is very crucial in order to achieve the desired properties and service life. This work studies the important variables affecting the grain size of such steels which includes the compositional and processing variables. The computational findings and prior knowledge is used to design the alloy, which is subjected to a few trials to validate the findings.

  13. Project STAR Research Synopsis: The Effect of Reduced Class Size on Kindergarten Reading Readiness.

    ERIC Educational Resources Information Center

    Bain, Helen Pate; Jacobs, Roseanne

    Effects of teacher-pupil ratio on kindergartners' mastery of reading readiness objectives were studied. The study was part of Tennessee's Project STAR, a 4-year study of class size. About 2,850 students in 38 elementary schools that served 4 types of communities: innercity, suburban, urban, and rural, in 26 Tennessee school systems participated.…

  14. Winter grazing can reduce wildfire size, intensity, and behavior in a shrub-grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. An increase in mega-fires and wildfires in general is a global issue that is expected to become worse with climate change. Fuel treatments are often recommended to decrease the risk, size, intensity, and severity of wildfires; however, the extensive nature of rangelands limits the use of many po...

  15. Motor-Reducer Sizing through a MATLAB-Based Graphical Technique

    ERIC Educational Resources Information Center

    Giberti, H.; Cinquemani, S.

    2012-01-01

    The design of the drive system for an automatic machine and its correct sizing is a very important competence for an electrical or mechatronic engineer. This requires knowledge that crosses the fields of electrical engineering, electronics and mechanics, as well as the skill to choose commercial components based upon their technical documentation.…

  16. 30 CFR 203.76 - When might MMS withdraw or reduce the approved size of my relief?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false When might MMS withdraw or reduce the approved size of my relief? 203.76 Section 203.76 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... ROYALTY RATES OCS Oil, Gas, and Sulfur General Royalty Relief for Pre-Act Deep Water Leases and...

  17. The Cumulative Effects of Indiana PRIME TIME: A State Sponsored Reduced Class Size Program, on Basic Skills Achievement.

    ERIC Educational Resources Information Center

    Malloy, Leanne; Gilman, David

    The purpose of this paper was to analyze the initial results of statewide implementation of the PRIME TIME program in Indiana. PRIME TIME is a state-wide program to reduce class size in the primary grades. Mean scores from 65,911 third graders who had completed the Indiana Competency Test in the spring of 1987 after completing 3 years of the…

  18. Testing Probation Outcomes in an Evidence-Based Practice Setting: Reduced Caseload Size and Intensive Supervision Effectiveness

    ERIC Educational Resources Information Center

    Jalbert, Sarah Kuck; Rhodes, William; Flygare, Christopher; Kane, Michael

    2010-01-01

    Probation and parole professionals argue that supervision outcomes would improve if caseloads were reduced below commonly achieved standards. Criminal justice researchers are skeptical because random assignment and strong observation studies have failed to show that criminal recidivism falls with reductions in caseload sizes. One explanation is…

  19. Brokering Dialogue between Secondary Students and Teachers to Co-Construct Appropriate Pedagogy in Reduced-Size Classes

    ERIC Educational Resources Information Center

    Harfitt, Gary James

    2014-01-01

    This study focuses on how two teachers working in reduced-size secondary classes of the same grade adapted their pedagogy as a result of a brokered dialogue between myself as researcher and 43 grade 10 students from the teachers' classes. Research was carried out over the course of one academic year. First, students' perspectives on…

  20. BIOREACTOR ECONOMICS, SIZE AND TIME OF OPERATION (BEST) COMPUTER SIMULATOR FOR DESIGNING SULFATE-REDUCING BACTERIA FIELD BIOREACTORS

    EPA Science Inventory

    BEST (bioreactor economics, size and time of operation) is an Excel™ spreadsheet-based model that is used in conjunction with the public domain geochemical modeling software, PHREEQCI. The BEST model is used in the design process of sulfate-reducing bacteria (SRB) field bioreacto...

  1. Derivatives of a statically reduced stiffness matrix with respect to sizing variables. [for aircraft weight minimization with flutter constraints

    NASA Technical Reports Server (NTRS)

    Oconnell, R. F.; Hassig, H. J.; Radovcich, N. A.

    1976-01-01

    An expression is obtained for the first derivatives with respect to the sizing variables of a statically reduced stiffness matrix that is a nonlinear function of the sizing variables, where the unreduced stiffness matrix is a linear function of the sizing variables. An accepted procedure to reduce the number of degrees of freedom is to eliminate a number of nodal displacements from the degrees of freedom such that the accuracy of the flutter analysis is not significantly affected. In a typical optimization procedure with flutter constraints, the derivative of the stiffness matrix may be used in a form that contains the characteristic vector of the flutter matrix equation and the transpose of the characteristic vector of the adjoint flutter matrix equation corresponding to a particular solution of the flutter equation.

  2. Counting the platelets: a robust and sensitive quantification method for thrombus formation.

    PubMed

    Claesson, Kjersti; Lindahl, Tomas L; Faxälv, Lars

    2016-06-01

    Flow chambers are common tools used for studying thrombus formation in vitro. However, the use of such devices is not standardised and there is a large diversity among the flow chamber systems currently used, and also in the methods used for quantifying the thrombus development. It was the study objective to evaluate a new method for analysis and quantification of platelet thrombus formation that can facilitate comparison of results between research groups. Whole blood was drawn over a collagen patch in commercial Ibid or in-house constructed PDMS flow chambers. Five percent of the platelets were fluorescently labelled and z-stack time-lapse images were captured during thrombus formation. Images were processed in a Python script in which the number of platelets and their respective x-, y- and z-positions were obtained. For comparison with existing methods the platelets were also labelled and quantified using fluorescence intensity and thrombus volume estimations by confocal microscopy. The presented method was found less sensitive to microscope and image adjustments and provides more details on thrombus development dynamics than the methods for measuring fluorescence intensity and thrombus volume estimation. The platelet count method produced comparable results with commercial and PDMS flow chambers, and could also obtain information regarding the stability of each detected platelet in the thrombus. In conclusion, quantification of thrombus formation by platelet count is a sensitive and robust method that enables measurement of platelet accumulation and platelet stability in an absolute scale that could be used for comparisons between research groups. PMID:26842994

  3. Enhancement of coercivity with reduced grain size in CoCrPt film grown by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Liang, Q.; Hu, X. F.; Li, H. Q.; He, X. X.; Wang, Xiaoru; Zhang, W.

    2006-04-01

    We report a pulsed laser deposition (PLD) growth of VMn/CoCrPt bilayer with a magnetic coercivity ( Hc) of 2.2 kOe and a grain size of 12 nm. The effects of VMn underlayer on magnetic properties of CoCrPt layer were studied. The coercivity, Hc, and squareness, S, of VMn/CoCrPt bilayer, is dependent on the thickness of VMn. The grain size of the CoCrPt film can also be modified by laser parameters. High laser fluence used for CoCrPt deposition produces a smaller grain size. Enhanced Hc and reduced grain size in VMn/CoCrPt is explained by more pronounced surface phase segregation during deposition at high laser fluence.

  4. Is vector body size the key to reduced malaria transmission in the irrigated region of Niono, Mali?

    PubMed

    Manoukis, Nicholas C; Touré, Mahamoudou B; Sissoko, Ibrahim; Doumbia, Seydou; Traoré, Sekou F; Diuk-Wasser, Maria A; Taylor, Charles E

    2006-09-01

    Malaria vectors can reach very high densities in villages near irrigated rice fields in Africa, leading to the expectation that malaria should be especially prevalent there. Surprisingly, this is not always the case. In Niono, Mali, villages from nonirrigated areas have higher malaria prevalence than those within the irrigated regions, which suffer from higher mosquito numbers. One hypothesis explaining this observation is that mosquitoes from irrigated fields with high densities are inefficient vectors. This could occur if higher larval densities lead to smaller mosquitoes that suffer elevated mortality. Three predictions of the hypothesis were studied. First, the effect of larval density on larval body size was measured for both Anopheles gambiae Giles and Anopheles funestus Giles. Second, the relationship between larval and adult body size was tested. Third, evidence of an effect of adult size on survivorship in both irrigated and nonirrigated villages during the wet and dry seasons was sought. There was a modest positive relationship between densities of immatures and larval size, and a strong relationship between larval and adult size. Furthermore, adult survivorship was higher in nonirrigated areas. However, there was no effect of size on survivorship between comparable samples from both the irrigated and nonirrigated zones. Although density may have a causal relationship with reduced transmission in the irrigated areas of Niono, it is unlikely to be because higher density leads to smaller body size and lower survivorship. PMID:17017214

  5. High-intensity training reduces intermittent hypoxia-induced ER stress and myocardial infarct size.

    PubMed

    Bourdier, Guillaume; Flore, Patrice; Sanchez, Hervé; Pepin, Jean-Louis; Belaidi, Elise; Arnaud, Claire

    2016-01-15

    Chronic intermittent hypoxia (IH) is described as the major detrimental factor leading to cardiovascular morbimortality in obstructive sleep apnea (OSA) patients. OSA patients exhibit increased infarct size after a myocardial event, and previous animal studies have shown that chronic IH could be the main mechanism. Endoplasmic reticulum (ER) stress plays a major role in the pathophysiology of cardiovascular disease. High-intensity training (HIT) exerts beneficial effects on the cardiovascular system. Thus, we hypothesized that HIT could prevent IH-induced ER stress and the increase in infarct size. Male Wistar rats were exposed to 21 days of IH (21-5% fraction of inspired O2, 60-s cycle, 8 h/day) or normoxia. After 1 wk of IH alone, rats were submitted daily to both IH and HIT (2 × 24 min, 15-30m/min). Rat hearts were either rapidly frozen to evaluate ER stress by Western blot analysis or submitted to an ischemia-reperfusion protocol ex vivo (30 min of global ischemia/120 min of reperfusion). IH induced cardiac proapoptotic ER stress, characterized by increased expression of glucose-regulated protein kinase 78, phosphorylated protein kinase-like ER kinase, activating transcription factor 4, and C/EBP homologous protein. IH-induced myocardial apoptosis was confirmed by increased expression of cleaved caspase-3. These IH-associated proapoptotic alterations were associated with a significant increase in infarct size (35.4 ± 3.2% vs. 22.7 ± 1.7% of ventricles in IH + sedenary and normoxia + sedentary groups, respectively, P < 0.05). HIT prevented both the IH-induced proapoptotic ER stress and increased myocardial infarct size (28.8 ± 3.9% and 21.0 ± 5.1% in IH + HIT and normoxia + HIT groups, respectively, P = 0.28). In conclusion, these findings suggest that HIT could represent a preventive strategy to limit IH-induced myocardial ischemia-reperfusion damages in OSA patients. PMID:26566725

  6. Herniated disks unchanged over time: Size reduced after oxygen-ozone therapy.

    PubMed

    Bonetti, Matteo; Zambello, Alessio; Leonardi, Marco; Princiotta, Ciro

    2016-08-01

    The spontaneous regression of disk herniation secondary to dehydration is a much-debated topic in medicine. Some physicians wonder whether surgical removal of the extruded nucleus pulposus is really necessary when the spontaneous disappearance of a herniated lumbar disk is a well-known phenomenon. Unfortunately, without spontaneous regression, chronic pain leads to progressive disability for which surgery seems to be the only solution. In recent years, several studies have demonstrated the utility of oxygen-ozone therapy in the treatment of disk herniation, resulting in disk shrinkage. This retrospective study evaluates the outcomes of a series of patients with a history of herniated disks neuroradiologically unchanged in size for over two years, treated with oxygen-ozone therapy at our center over the last 15 years. We treated 96 patients, 84 (87.5%) presenting low back pain complicated or not by chronic sciatica. No drug therapy had yielded significant benefits. A number of specialists had been consulted in two or more years resulting in several neuroradiological scans prior to the decision to undertake oxygen-ozone therapy. Our study documents how ozone therapy for slipped disks "unchanged over time" solved the problem, with disk disruption or a significant reduction in the size of the prolapsed disk material extruded into the spinal canal. PMID:27066816

  7. Significant enhancement of the thermoelectric figure of merit of polycrystalline Si films by reducing grain size

    NASA Astrophysics Data System (ADS)

    Valalaki, K.; Vouroutzis, N.; Nassiopoulou, A. G.

    2016-08-01

    The thermoelectric properties of p-type polycrystalline silicon thin films deposited by low pressure chemical vapour deposition (LPCVD) were accurately determined at room temperature and the thermoelectric figure of merit was deduced as a function of film thickness, ranging from 100 to 500 nm. The effect of film thickness on their thermoelectric performance is discussed. More than threefold increase in the thermoelectric figure of merit of the 100 nm thick polysilicon film was observed compared to the 500 nm thick film, reaching a value as high as 0.033. This enhancement is mainly the result of the smaller grain size in the thinner films. With the decrease in grain size the resistivity of the films is increased twofold and electrical conductivity decreased, however the Seebeck coefficient is increased by 30% and the thermal conductivity is decreased eightfold, being mainly at the origin of the increased figure of merit of the 100 nm film. Our experimental results were compared to known theoretical models and the possible mechanisms involved are presented and discussed.

  8. Transient response in longitudinal grain size to reduced sediment supply in a large river

    NASA Astrophysics Data System (ADS)

    Singer, Michael

    2010-05-01

    Bed material grain size is an important degree of freedom in fluvial systems as they adjust to system-wide perturbations such as sediment supply changes. However, little is known about processes and patterns of such adjustment in longitudinal grain size sorting in large rivers. This research uses unprecedented datasets collected in a large fluvial system to investigate transient response to recent supply changes associated with anthropogenic activities. Separate fining trends for gravel and fines, a protracted gravel-sand (G-S) transition, and bed patchiness identified in Singer (2008) were interrogated using output from a hydraulic model with grain size distributions (GSDs) extracted from ~125 cross sections spanning ~400 river kilometers of the Sacramento River, California. The analysis suggests that interactions between hydraulics, bed material sorting, and sediment flux explain these previously identified anomalies. Highest values of sorting occur in the G-S transition and represent the overlap of separate fining trends for gravel and fines, where the long profile is jagged with evidence of progressive incision. Much of the sediment in this poorly sorted zone is organized into patches, where transport apparently occurs as bedload sheets. Patchiness occurs over short length scales leading to strong differences in entrainment and flux, regardless of hydraulic conditions. A modified Shields stress is proposed that is scaled by GSD sorting to improve characterization of entrainment/disentrainment. Sediment flux calculations based on an equation sensitive bed material conditions (Singer and Dunne, 2004) reveal a strong relationship between fine sediment flux and d90, suggesting that the efficiency of fine patch flux controls bed material bed surface roughness. Results are in part consistent with Paola and Seal (1995) suggesting that patches are a result of overlapping pdfs of shear stress and sorting and with Ferguson (2003) in that the final end of the protracted G

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

    PubMed Central

    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

  10. Fibrinolytic treatment of thrombus on prosthetic heart valves.

    PubMed Central

    Witchitz, S; Veyrat, C; Moisson, P; Scheinman, N; Rozenstajn, L

    1980-01-01

    Fibrinolytic agents were administered for 13 episodes of thrombus formation on mitral or aortic valvar prostheses in 12 patients. The most common presenting features were pulmonary oedema (six cases) or arterial emboli (six cases). The diagnosis of thrombus formation was made by phonocardiography on the following criteria: (a) modifications of the prosthetic sounds (12 cases), (b) appearance of a valvar obstructive syndrome (10 cases). The treatment consisted of streptokinase (100 000 units/h after a loading dose, seven cases) or urokinase using either low doses (75 000 or 112 500 units/h, three cases) or moderate doses (150 000 units/h, three cases) for one to four days. Immediate complete regression of clinical and phonocardiographic anomalies was seen in eight cases. Incomplete improvement was seen in two patients, leading to operation: this was unsuccessful in one patient who had surgery on the third day, and was successful in the other on the 75th day. There were three failures leading to successful reoperative procedures in two patients and to an early death in the third patient suffering from acute myocardial infarction. One non-fatal haemopericardium was observed in a patient treated with streptokinase. No important side effect was noted during delivery in a pregnant woman. During subsequent follow-up, a recurrent episode of thrombus formation was observed in one patient, treated by fibrinolytic therapy with success. One patient had an operation for a valve replacement six months after fibrinolytic treatment because of non-thrombotic valvar dysfunction; the outcome was fatal. Six patients are alive and in good condition, with a follow-up of six months to five years. Images PMID:7437196

  11. Carotid artery free-floating thrombus caused by paradoxical embolization from greater saphenous vein ascending thrombophlebitis.

    PubMed

    Irace, Luigi; Gabrielli, Roberto; Rosati, Maria Sofia; Giannoni, Maria Fabrizia; Castiglione, Anna; Laurito, Antonella; Gossetti, Bruno

    2013-05-01

    Stroke of unknown origin in young patients is seen to be closely correlated with patent foramen ovale (PFO) than stroke in patients with established stroke mechanisms. We report a case of a young woman without cardiovascular risk factors who was admitted to our emergency department with listlessness and altered mental status. The clinical examination revealed right lower limb swelling. Magnetic resonance imaging and contrast-enhanced computed tomographic scans revealed a free floating thrombus of the left internal carotid artery (ICA) with a large bilateral frontal ischemic lesion. The diagnosis of a medium-sized PFO with moderate right-to-left contrast shunting was made after transesophageal echocardiography. No other cardiac sources for embolization were detected, while an ascending thrombophlebitis of the right greater saphenous vein was detected by venous Doppler ultrasonography. These findings support the diagnosis of ICA free-floating thrombus caused by paradoxical embolization (via the PFO) of clot from the greater saphenous vein. The patient underwent emergency saphenofemoral disconnection with femoral vein thrombectomy and subsequently carotid artery thrombectomy under general anesthesia. No carotid atheromatous wall lesions were detected at surgical exploration; no immunologic pathology, hypercoagulable status, or malignancy were recorded. No hemorrhagic cerebral complications were observed in the postoperative period, and the patient had an improvement of her neurologic status (a reduction of the National Institutes of Health Stroke Scale score from 7 to 3). Her recovery was uneventful. The patient was transferred for rehabilitation on postoperative day 5 with oral anticoagulation. Six-month ultrasound follow-up revealed deep and superficial venous system and carotid artery patency. The patient was asymptomatic and anticoagulation was discontinued. Paradoxical cerebral embolization through a PFO is a rare phenomenon that, in our patient, appeared to have

  12. Role of Gas6 receptors in platelet signaling during thrombus stabilization and implications for antithrombotic therapy

    PubMed Central

    Angelillo-Scherrer, Anne; Burnier, Laurent; Flores, Nathalie; Savi, Pierre; DeMol, Maria; Schaeffer, Paul; Herbert, Jean-Marc; Lemke, Greg; Goff, Stephen P.; Matsushima, Glenn K.; Earp, H. Shelton; Vesin, Christian; Hoylaerts, Marc F.; Plaisance, Stéphane; Collen, Désiré; Conway, Edward M.; Wehrle-Haller, Bernhard; Carmeliet, Peter

    2005-01-01

    Mechanisms regulating thrombus stabilization remain largely unknown. Here, we report that loss of any 1 of the Gas6 receptors (Gas6-Rs), i.e., Tyro3, Axl, or Mer, or delivery of a soluble extracellular domain of Axl that traps Gas6 protects mice against life-threatening thrombosis. Loss of a Gas6-R does not prevent initial platelet aggregation but impairs subsequent stabilization of platelet aggregates, at least in part by reducing “outside-in” signaling and platelet granule secretion. Gas6, through its receptors, activates PI3K and Akt and stimulates tyrosine phosphorylation of the β3 integrin, thereby amplifying outside-in signaling via αIIbβ3. Blocking the Gas6-R–αIIbβ3 integrin cross-talk might be a novel approach to the reduction of thrombosis. PMID:15650770

  13. Platelet receptors and signaling in the dynamics of thrombus formation

    PubMed Central

    Rivera, José; Lozano, María Luisa; Navarro-Núñez, Leyre; Vicente, Vicente

    2009-01-01

    Hemostasis and pathological thrombus formation are dynamic processes that require a co-ordinated series of events involving platelet membrane receptors, bidirectional intracellular signals, and release of platelet proteins and inflammatory substances. This review aims to summarize current knowledge in the key steps in the dynamics of thrombus formation, with special emphasis on the crucial participation of platelet receptors and signaling in this process. Initial tethering and firm adhesion of platelets to the exposed subendothelium is mediated by glycoprotein (GP) Ib/IX/V complex and collagen receptors, GP VI and α2β1 integrin, in the platelet surface, and by VWF and fibrillar collagen in the vascular site. Interactions between these elements are largely influenced by flow and trigger signaling events that reinforce adhesion and promote platelet activation. Thereafter, soluble agonists, ADP, thrombin, TxA2, produced/released at the site of vascular injury act in autocrine and paracrine mode to amplify platelet activation and to recruit circulating platelets to the developing thrombus. Specific interactions of these agonists with their G-protein coupled receptors generate inside-out signaling leading to conformational activation of integrins, in particular αIIbβ3, increasing their ligand affinity. Binding of αIIbβ3 to its ligands, mainly fibrinogen, supports processes such as clot retraction and platelet aggregation. Stabilization of thrombi is supported by the late wave of signaling events promoted by close contact between aggregated platelets. The best known contact-dependent signaling is outside-in signaling through αIb β3, but new ones are being clarified such as those mediated by interaction of Eph receptors with ephrins, or by Sema 4D and Gas-6 binding to their receptors. Finally, newly identified mechanisms appear to control thrombus growth, including back-shifting of activated integrins and actuation of compensatory molecules such as ESAM or PECAM-1

  14. Left ventricular thrombus associated with arteriovenous extra corporeal membrane oxygenation

    PubMed Central

    Makdisi, George; Hashmi, Zubair A.; Wozniak, Thomas C.

    2015-01-01

    Extra corporeal membrane oxygenation (ECMO) has remarkably progressed over the recent years. It has become an invaluable tool in the care of adults and pediatric patients with severe cardiogenic shock. At the initiation of ECMO support, the left ventricular contractility is profoundly impaired. Inadequate right ventricular drainage and bronchial circulation can lead to left ventricular distension, with potential deleterious consequences, ranging from inadequate myocardial rest, pulmonary edema, or intracardiac clot formation. Therefore, it is of extreme importance to ensure an adequate left ventricular drainage. Here we present a case of LV thrombus developed while the patient is on central venoarterial (VA) ECMO. PMID:26716054

  15. Left ventricular thrombus associated with arteriovenous extra corporeal membrane oxygenation.

    PubMed

    Makdisi, George; Hashmi, Zubair A; Wozniak, Thomas C; Wang, I-Wen

    2015-11-01

    Extra corporeal membrane oxygenation (ECMO) has remarkably progressed over the recent years. It has become an invaluable tool in the care of adults and pediatric patients with severe cardiogenic shock. At the initiation of ECMO support, the left ventricular contractility is profoundly impaired. Inadequate right ventricular drainage and bronchial circulation can lead to left ventricular distension, with potential deleterious consequences, ranging from inadequate myocardial rest, pulmonary edema, or intracardiac clot formation. Therefore, it is of extreme importance to ensure an adequate left ventricular drainage. Here we present a case of LV thrombus developed while the patient is on central venoarterial (VA) ECMO. PMID:26716054

  16. Reducing Size, Weight, and Power (SWaP) of Perception Systems in Small Autonomous Aerial Systems

    NASA Technical Reports Server (NTRS)

    Jones, Kennie H.; Gross, Jason

    2014-01-01

    The objectives are to examine recent trends in the reduction of size, weight, and power (SWaP) requirements of sensor systems for environmental perception and to explore new technology that may overcome limitations in current systems. Improving perception systems to facilitate situation awareness is critical in the move to introduce increasing autonomy in aerial systems. Whether the autonomy is in the current state-of-the-art of increasing automation or is enabling cognitive decisions that facilitate adaptive behavior, collection of environmental information and fusion of that information into knowledge that can direct actuation is imperative to decisions resulting in appropriate behavior. Artificial sensory systems such as cameras, radar, LIDAR, and acoustic sensors have been in use on aircraft for many years but, due to the large size and weight of the airplane and electrical power made available through powerful engines, the SWaP requirements of these sensors was inconsequential. With the proliferation of Remote Piloted Vehicles (RPV), the trend is in significant reduction in SWaP of the vehicles. This requires at least an equivalent reduction in SWaP for the sensory systems. A survey of some currently available sensor systems and changing technology will reveal the trend toward reduction of SWaP of these systems and will predict future reductions. A new technology will be introduced that provides an example of a desirable new trend. A new device replaces multiple conventional sensory devices facilitating synchronization, localization, altimetry, collision avoidance, terrain mapping, and data communication in a single integrated, small form-factor, extremely lightweight, and low power device that it is practical for integration into small autonomous vehicles and can facilitate cooperative behavior. The technology is based on Ultra WideBand (UWB) radio using short pulses of energy rather than continuous sine waves. The characteristics of UWB yield several

  17. Laser system refinements to reduce variability in infarct size in the rat photothrombotic stroke model

    PubMed Central

    Alaverdashvili, Mariam; Paterson, Phyllis G.; Bradley, Michael P.

    2015-01-01

    Background The rat photothrombotic stroke model can induce brain infarcts with reasonable biological variability. Nevertheless, we observed unexplained high inter-individual variability despite using a rigorous protocol. Of the three major determinants of infarct volume, photosensitive dye concentration and illumination period were strictly controlled, whereas undetected fluctuation in laser power output was suspected to account for the variability. New method The frequently utilized Diode Pumped Solid State (DPSS) lasers emitting 532 nm (green) light can exhibit fluctuations in output power due to temperature and input power alterations. The polarization properties of the Nd:YAG and Nd:YVO4 crystals commonly used in these lasers are another potential source of fluctuation, since one means of controlling output power uses a polarizer with a variable transmission axis. Thus, the properties of DPSS lasers and the relationship between power output and infarct size were explored. Results DPSS laser beam intensity showed considerable variation. Either a polarizer or a variable neutral density filter allowed adjustment of a polarized laser beam to the desired intensity. When the beam was unpolarized, the experimenter was restricted to using a variable neutral density filter. Comparison with existing method(s) Our refined approach includes continuous monitoring of DPSS laser intensity via beam sampling using a pellicle beamsplitter and photodiode sensor. This guarantees the desired beam intensity at the targeted brain area during stroke induction, with the intensity controlled either through a polarizer or variable neutral density filter. Conclusions Continuous monitoring and control of laser beam intensity is critical for ensuring consistent infarct size. PMID:25840363

  18. Nonlinear optical phase-conjugation techniques to reduce the physical size of lasers. Final technical report, May-July 1987

    SciTech Connect

    Pratt, H.L.

    1987-09-01

    Optical phase conjugation involves the use of various techniques to reverse the wavefront of an optical beam. Nonlinear optical interactions within various media may be used to generate phase conjugation. This report reviews the most-promising techniques for nonlinear optical phase conjugation and postulates how phase conjugation might be used to reduce the physical size of laser systems. A number of examples from literature are cited.

  19. Awns reduce grain number to increase grain size and harvestable yield in irrigated and rainfed spring wheat

    PubMed Central

    Rebetzke, G. J.; Bonnett, D. G.; Reynolds, M. P.

    2016-01-01

    Genotypic variation in ear morphology is linked to differences in photosynthetic potential to influence grain yield in winter cereals. Awns contribute to photosynthesis, particularly under water-limited conditions when canopy assimilation is restricted. We assessed performance of up to 45 backcross-derived, awned–awnletted NILs representing four diverse genetic backgrounds in 25 irrigated or rainfed, and droughted environments in Australia and Mexico. Mean environment grain yields were wide-ranging (1.38–7.93 t ha−1) with vegetative and maturity biomass, plant height, anthesis date, spike number, and harvest index all similar (P >0.05) for awned and awnletted NILs. Overall, grain yields of awned–awnletted sister-NILs were equivalent, irrespective of yield potential and genetic background. Awnletted wheats produced significantly more grains per unit area (+4%) and per spike (+5%) reflecting more fertile spikelets and grains in tertiary florets. Increases in grain number were compensated for by significant reductions in grain size (–5%) and increased frequency (+0.8%) of small, shrivelled grains (‘screenings’) to reduce seed-lot quality of awnletted NILs. Post-anthesis canopies of awnletted NILs were marginally warmer over all environments (+0.27 °C) but were not different and were sometimes cooler than awned NILs at cooler air temperatures. Awns develop early and represented up to 40% of total spikelet biomass prior to ear emergence. We hypothesize that the allocation of assimilate to large and rapidly developing awns decreases spikelet number and floret fertility to reduce grain number, particularly in distal florets. Individual grain size is increased to reduce screenings and to increase test weight and milling quality, particularly in droughted environments. Despite the average reduction in grain size, awnless lines could be identified that combined higher grain yield with larger grain size, increased grain protein concentration, and reduced

  20. Awns reduce grain number to increase grain size and harvestable yield in irrigated and rainfed spring wheat.

    PubMed

    Rebetzke, G J; Bonnett, D G; Reynolds, M P

    2016-04-01

    Genotypic variation in ear morphology is linked to differences in photosynthetic potential to influence grain yield in winter cereals. Awns contribute to photosynthesis, particularly under water-limited conditions when canopy assimilation is restricted. We assessed performance of up to 45 backcross-derived, awned-awnletted NILs representing four diverse genetic backgrounds in 25 irrigated or rainfed, and droughted environments in Australia and Mexico. Mean environment grain yields were wide-ranging (1.38-7.93 t ha(-1)) with vegetative and maturity biomass, plant height, anthesis date, spike number, and harvest index all similar (P >0.05) for awned and awnletted NILs. Overall, grain yields of awned-awnletted sister-NILs were equivalent, irrespective of yield potential and genetic background. Awnletted wheats produced significantly more grains per unit area (+4%) and per spike (+5%) reflecting more fertile spikelets and grains in tertiary florets. Increases in grain number were compensated for by significant reductions in grain size (-5%) and increased frequency (+0.8%) of small, shrivelled grains ('screenings') to reduce seed-lot quality of awnletted NILs. Post-anthesis canopies of awnletted NILs were marginally warmer over all environments (+0.27 °C) but were not different and were sometimes cooler than awned NILs at cooler air temperatures. Awns develop early and represented up to 40% of total spikelet biomass prior to ear emergence. We hypothesize that the allocation of assimilate to large and rapidly developing awns decreases spikelet number and floret fertility to reduce grain number, particularly in distal florets. Individual grain size is increased to reduce screenings and to increase test weight and milling quality, particularly in droughted environments. Despite the average reduction in grain size, awnless lines could be identified that combined higher grain yield with larger grain size, increased grain protein concentration, and reduced screenings. PMID

  1. Use of pharmacogenetics in bioequivalence studies to reduce sample size: an example with mirtazapine and CYP2D6.

    PubMed

    González-Vacarezza, N; Abad-Santos, F; Carcas-Sansuan, A; Dorado, P; Peñas-Lledó, E; Estévez-Carrizo, F; Llerena, A

    2013-10-01

    In bioequivalence studies, intra-individual variability (CV(w)) is critical in determining sample size. In particular, highly variable drugs may require enrollment of a greater number of subjects. We hypothesize that a strategy to reduce pharmacokinetic CV(w), and hence sample size and costs, would be to include subjects with decreased metabolic enzyme capacity for the drug under study. Therefore, two mirtazapine studies, two-way, two-period crossover design (n=68) were re-analysed to calculate the total CV(w) and the CV(w)s in three different CYP2D6 genotype groups (0, 1 and ≥ 2 active genes). The results showed that a 29.2 or 15.3% sample size reduction would have been possible if the recruitment had been of individuals carrying just 0 or 0 plus 1 CYP2D6 active genes, due to the lower CV(w). This suggests that there may be a role for pharmacogenetics in the design of bioequivalence studies to reduce sample size and costs, thus introducing a new paradigm for the biopharmaceutical evaluation of drug products. PMID:22733239

  2. Effect of homogenization techniques on reducing the size of microcapsules and the survival of probiotic bacteria therein.

    PubMed

    Ding, W K; Shah, N P

    2009-08-01

    This study investigated 2 different homogenization techniques for reducing the size of calcium alginate beads during the microencapsulation process of 8 probiotic bacteria strains, namely, Lactobacillus rhamnosus, L. salivarius, L. plantarum, L. acidophilus, L. paracasei, Bifidobacterium longum, B. lactis type Bi-04, and B. lactis type Bi-07. Two different homogenization techniques were used, namely, ultra-turrax benchtop homogenizer and Microfluidics microfluidizer. Various settings on the homogenization equipment were studied such as the number of passes, speed (rpm), duration (min), and pressure (psi). The traditional mixing method using a magnetic stirrer was used as a control. The size of microcapsules resulting from the homogenization technique, and the various settings were measured using a light microscope and a stage micrometer. The smallest capsules measuring (31.2 microm) were created with the microfluidizer using 26 passes at 1200 psi for 40 min. The greatest loss in viability of 3.21 log CFU/mL was observed when using the ultra-turrax benchtop homogenizer with a speed of 1300 rpm for 5 min. Overall, both homogenization techniques reduced capsule sizes; however, homogenization settings at high rpm also greatly reduced the viability of probiotic organisms. PMID:19723206

  3. Reduced molecular size and altered disaccharide composition of cerebral chondroitin sulfate upon Alzheimer's pathogenesis in mice.

    PubMed

    Zhang, Zui; Ohtake-Niimi, Shiori; Kadomatsu, Kenji; Uchimura, Kenji

    2016-08-01

    Alzheimer's disease (AD) is a progressive disorder leading to cognitive impairment and neuronal loss. Cerebral extracellular accumulation and deposition of amyloid ß plaques is a pathological hallmark of AD. Chondroitin sulfate (CS) is an extracellular component abundant in the brain. CS is a sulfated glycosaminoglycan covalently attached to a core protein, forming chondroitin sulfate proteoglycan. The structure of CS is heterogeneous with sulfation modification and elongation of the chain. The structural diversity of CS allows it to play various roles in the brain. Increasing evidence has shown that CS promotes aggregation of amyloid ß peptides into higher-order species such as insoluble amyloid ß fibrils. Difficulties in the structural analysis of brain CS, as well as its heterogeneity, limit the study of potential roles of CS in AD pathology. Here we established a microanalysis method with reversed-phase ion-pair high performance liquid chromatography and found that CS in the brains of Tg2576 AD model mice show a lower molecular size and an increased ratio of CS-B motif di-sulfated disaccharide. Our findings provide insight into the structural changes of cerebral CS upon Alzheimer's pathogenesis. PMID:27578913

  4. Reducing the size of the human physiological blind spot through training.

    PubMed

    Miller, Paul A; Wallis, Guy; Bex, Peter J; Arnold, Derek H

    2015-08-31

    The physiological blind spot refers to a zone of functional blindness all normally sighted people have in each eye, due to an absence of photoreceptors where the optic nerve passes through the surface of the retina. Here we report that the functional size of the physiological blind spot can be shrunk through training to distinguish direction signals at the blind spot periphery. Training on twenty successive weekdays improved sensitivity to both direction and colour, suggesting a generalizable benefit. Training on one blind spot, however, did not transfer to the blind spot in the untrained eye, ruling out mediation via a generic practice effect; nor could training benefits be attributed to eye movements, which were monitored to ensure stable fixation. These data suggest that training enhances the response gains of neurons with receptive fields that partially overlap, or abut, the physiological blind spot, thereby enhancing sensitivity to weak signals originating primarily from within the functionally-defined region of blindness [1-3]. Our results have important implications for situations where localised blindness has been acquired through damage to components of the visual system [4,5], and support proposals that these situations might be improved through perceptual training [5-7]. PMID:26325131

  5. Transcatheter Therapy for a Large Mobile Right Atrial Thrombus and Massive Pulmonary Embolism.

    PubMed

    Narang, Akhil; Mediratta, Anuj; Estrada, Jeremy R; Rosenberg, Jonathan; DeCara, Jeanne M; Howell, Michael D; Lang, Roberto M; Paul, Jonathan D; Nathan, Sandeep; Shah, Atman P; Blair, John E

    2016-05-01

    A variety of interventional management approaches exist for the treatment of acute pulmonary embolism (PE). However, when PE is accompanied by residual right heart thrombus, the best therapeutic options are less clear. We describe a novel combined technique of percutaneous aspiration of unstable right atrial thrombus followed by ultrasound-directed thrombolysis of massive PE. PMID:27145056

  6. AngioVac extraction of intra-atrial hepatoma masquerading as PICC-associated thrombus

    PubMed Central

    Abboud, Samir; Raparia, Kirtee; Ubago, Julianne M.; Resnick, Scott

    2016-01-01

    Thrombus associated with peripherally inserted central catheterization is not uncommon. Treatment is typically conservative; however, more aggressive therapies can be considered in patients with tenuous medical condition. The authors present a patient with metastatic hepatocellular carcinoma masquerading as peripherally inserted central catheter-associated intra-atrial thrombus, subsequently removed via vacuum-assisted mechanical thrombectomy. PMID:26509915

  7. AngioVac extraction of intra-atrial hepatoma masquerading as PICC-associated thrombus.

    PubMed

    Abboud, Samir; Raparia, Kirtee; Ubago, Julianne M; Resnick, Scott

    2016-01-01

    Thrombus associated with peripherally inserted central catheterization is not uncommon. Treatment is typically conservative; however, more aggressive therapies can be considered in patients with tenuous medical condition. The authors present a patient with metastatic hepatocellular carcinoma masquerading as peripherally inserted central catheter-associated intra-atrial thrombus, subsequently removed via vacuum-assisted mechanical thrombectomy. PMID:26509915

  8. Dual antiplatelet agents and Rivaroxaban for massive intracoronary thrombus in STEMI.

    PubMed

    Jamal, Nasiruddin; Bapumia, Mustaafa

    2015-11-01

    Management of intracoronary thrombus in patients presenting more than 12 hours after the onset of ST elevation myocardial infarction is challenging. We present such a case which had massive thrombus in left anterior descending artery. It was managed successfully with dual antiplatelet agents and factor Xa inhibitor rivaroxaban administered orally. PMID:26576274

  9. Dual antiplatelet agents and Rivaroxaban for massive intracoronary thrombus in STEMI

    PubMed Central

    Jamal, Nasiruddin; Bapumia, Mustaafa

    2015-01-01

    Key Clinical Message Management of intracoronary thrombus in patients presenting more than 12 hours after the onset of ST elevation myocardial infarction is challenging. We present such a case which had massive thrombus in left anterior descending artery. It was managed successfully with dual antiplatelet agents and factor Xa inhibitor rivaroxaban administered orally. PMID:26576274

  10. Tumour thrombus consistency has no impact on survival in patients with renal cell carcinoma.

    PubMed

    Gołąbek, T; Przydacz, M; Okoń, K; Kopczyński, J; Bukowczan, J; Sobczyński, R; Curyło, Ł; Gołąbek, K; Curyło, Ł; Chłosta, P

    2016-06-01

    The prognosis of renal cell carcinoma (RCC) with venous tumour thrombus (VTT) is variable and not always possible to predict. The prognostic impact and independence of tumour thrombus-related factors including the recently introduced tumour thrombus consistency (TTC) on overall survival remain controversial. The aim of this study was to investigate the prognostic role of TTC in patients' survival. We determined the tumour thrombus consistency (solid vs. friable) in a cohort of 84 patients with RCC and VTT who underwent nephrectomy with thrombectomy, and performed a retrospective evaluation of the patients' data from the prospectively maintained database. A total of 45% of patients had solid thrombus (sTT) and 55% had friable thrombus (fTT). The venous tumour thrombus consistency was not predictive of overall survival. Further studies, preferably prospective and with a larger number of patients, are needed to validate the obtained results, as well as to evaluate the usefulness of tumour thrombus consistency in clinical practice for stratifying the risk of recurrence and planning further follow-up. PMID:27543869

  11. The impact of using reduced capacity baskets on cask fleet size and cask fleet mix

    SciTech Connect

    Joy, D.S.; Johnson, P.E.; Andress, D.A.

    1993-06-01

    The Civilian Radioactive Waste Management System transportation system will encounter a wide range of spent fuel characteristics. Since the Initiative I casks are being designed to transport 10-year-old fuel with a burnup of 35,000 MWd/MTU, there is a good likelihood that a number of the cask shipments will need to be derated in order to meet the Nuclear Regulatory Commission radiation guidelines. This report discusses the impact of cask derating by using reduced-capacity baskets. Cask derating, while enhancing the ability to move spent fuel with a wider range of age and burnup characteristics, increases the number of shipments; the amount of equipment (cask bodies, baskets, etc.); and the number of visits to both shipping and receiving sites required to transport a specific amount of spent fuel.

  12. Diverse Findings in Calcified Thrombus Between Histopathology and In Vivo Imaging Including Intravascular Ultrasound, Optical Coherence Tomography, and Angioscopy.

    PubMed

    Koga, Seiji; Ikeda, Satoshi; Nakata, Tomoo; Kawano, Hiroaki; Abe, Kuniko; Maemura, Koji

    2015-01-01

    A 46-year-old woman on hemodialysis due to end-stage renal disease was admitted for repeated thrombus formation in previously implanted drug-eluting stents in the right coronary artery. We could successfully aspirate this thrombus, and histopathology revealed a calcified thrombus comprising multiple microcalcifications and fibrinous materials. This is the first report showing how a calcified thrombus is visualized in vivo by intracoronary imaging modalities including intravascular ultrasound, optical coherence tomography, and angioscopy. PMID:26549397

  13. Breast IMRT Reduces Time Spent with Acute Dermatitis For Women of All Breast Sizes During Radiation

    PubMed Central

    Freedman, Gary M; Li, Tianyu; Nicolaou, Nicos; Chen, Yan; Ma, Charlie C-M; Anderson, Penny R

    2009-01-01

    Purpose To study the time spent with radiation-induced dermatitis during a course of radiation therapy for breast cancer in women treated with conventional or intensity-modulated radiation therapy (IMRT). Materials and methods The study population consisted of 804 consecutive women with early-stage breast cancer treated with breast-conserving surgery and radiation from 2001 – 2006. All patients were treated with whole-breast radiation followed by a boost to the tumor bed. Whole-breast radiation consisted of conventional wedged photon tangents (n=405) earlier in the study period and mostly of photon IMRT (n=399) in later years. All patients had acute dermatitis graded each week of treatment. Results The breakdown of the cases of maximum acute dermatitis by grade was as follows: 3%, grade 0; 34%, grade 1; 61%, grade 2; and 2%, grade 3. The breakdown of cases of maximum toxicity by technique was as follows: 48%, grade 0/1, and 52%, grade 2/3, for IMRT, and 25%, grade 0/1, and 75%, grade 2/3, for conventional radiation therapy (p<0.0001). IMRT patients spent 82% of weeks during treatment with grade 0/1 dermatitis and 18% with grade 2/3 dermatitis, compared with 29% and 71% of patients, respectively, treated with conventional radiation (p<0.0001). Further, the time spent with grade 2/3 toxicity was decreased in IMRT patients with small (p=0.0015), medium (p<0.0001), and large (p<0.0001) breasts. Conclusions Breast IMRT is associated with both a significant decrease in the time spent during treatment with grade 2/3 dermatitis and in the maximum severity of dermatitis compared with conventional radiation regardless of breast size. PMID:19362779

  14. Predictors of thrombus burden and no-reflow of infarct-related artery in patients with ST-segment elevation myocardial infarction: importance of platelet indices.

    PubMed

    Cakici, Musa; Cetin, Mustafa; Balli, Mehmet; Akturk, Erdal; Dogan, Adnan; Oylumlu, Muhammed; Abus, Sabri; Yildiz, Emrah; Sungur, Azmi; Celiker, Meral

    2014-10-01

    Preprocedural high-thrombus burden (HTB) of infarct-related artery (IRA) is a harbinger of procedural complications following primary percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). The HTB of IRA can lead to poor outcomes by various mechanisms, including no-reflow phenomenon, increased myocardial necrosis and with subsequent reduced survival benefit at follow-up. In this study, we investigated the relationship between all platelet indices on admission and thrombus burden and the no-reflow phenomenon after primary PCI of IRA in patients with STEMI. We retrospectively enrolled 475 patients with STEMI undergoing primary PCI. Study population was divided into two groups according to the thrombolysis in myocardial infarction thrombus grade of IRA as low-thrombus burden or HTB. There were no statistically significant differences in platelet indices, including platelet count, platelet-large cell ratio (P-LCR), mean platelet volume (MPV) and platelet distribution with (PDW) among the groups. However, in the subgroup analysis, P-LCR, MPV and PDW were significantly higher in the no-reflow patients than reflow patients despite similar platelet count (P for all < 0.001). The cutoff value of P-LCR for predicting no-reflow was 26.5% with a sensitivity of 67.0% and a specificity of 62% (area under the curve, 0.689; 95% confidence interval, 0.614-0.765; P < 0.001). Furthermore, P-LCR, MPV and PDW had similar AUC (0.689, P < 0.001; 0.688, P < 0.001; and 0.677, P < 0.001; respectively) for predicting no-reflow phenomenon after primary PCI. As a result, all of the platelet indices have no effect on thrombus load of IRA, however, these parameters seem to impair epicardial perfusion after primary PCI. PMID:24806326

  15. Antiadhesive effect of fibrinogen: a safeguard for thrombus stability

    PubMed Central

    Lishko, Valeryi K.; Burke, Timothy; Ugarova, Tatiana

    2007-01-01

    The recruitment of phagocytic leukocytes to sites of vessel wall injury plays an important role in thrombus dissolution by proteases elaborated on their adhesion. However, leukocyte adhesion to the fibrin clot can be detrimental at the early stages of wound healing when hemostatic plug integrity is critical for preventing blood loss. Adhesion of circulating leukocytes to the insoluble fibrin(ogen) matrix is mediated by integrins and occurs in the presence of a high concentration of plasma fibrinogen. In this study, the possibility that soluble fibrinogen could protect fibrin from excessive adhesion of leukocytes was examined. Fibrinogen was a potent inhibitor of adhesion of U937 monocytoid cells and neutrophils to fibrin gel and immobilized fibrin(ogen). An investigation of the mechanism by which soluble fibrinogen exerts its influence on leukocyte adhesion indicated that it did not block integrins but rather associated with the fibrin(ogen) substrate. Consequently, leukocytes that engage fibrinogen molecules loosely bound to the surface of fibrin(ogen) matrix are not able to consolidate their grip on the substrate; subsequently, cells detach. This conclusion is based on the evidence obtained in adhesion studies using various cells and performed under static and flow conditions. These findings reveal a new role of fibrinogen in integrin-mediated leukocyte adhesion and suggest that this mechanism may protect the thrombus from premature dissolution. PMID:16849640

  16. Platelet adhesion signalling and the regulation of thrombus formation.

    PubMed

    Gibbins, Jonathan M

    2004-07-15

    Platelets perform a central role in haemostasis and thrombosis. They adhere to subendothelial collagens exposed at sites of blood vessel injury via the glycoprotein (GP) Ib-V-IX receptor complex, GPVI and integrin alpha(2)beta(1). These receptors perform distinct functions in the regulation of cell signalling involving non-receptor tyrosine kinases (e.g. Src, Fyn, Lyn, Syk and Btk), adaptor proteins, phospholipase C and lipid kinases such as phosphoinositide 3-kinase. They are also coupled to an increase in cytosolic calcium levels and protein kinase C activation, leading to the secretion of paracrine/autocrine platelet factors and an increase in integrin receptor affinities. Through the binding of plasma fibrinogen and von Willebrand Factor to integrin alpha(IIb)beta(3), a platelet thrombus is formed. Although increasing evidence indicates that each of the adhesion receptors GPIb-V-IX and GPVI and integrins alpha(2)beta(1) and alpha(IIb)beta(3) contribute to the signalling that regulates this process, the individual roles of each are only beginning to be dissected. By contrast, adhesion receptor signalling through platelet endothelial cell adhesion molecule 1 (PECAM-1) is implicated in the inhibition of platelet function and thrombus formation in the healthy circulation. Recent studies indicate that understanding of platelet adhesion signalling mechanisms might enable the development of new strategies to treat and prevent thrombosis. PMID:15252124

  17. Multiscale Simulation for the Initial Stage of Thrombus Formation

    NASA Astrophysics Data System (ADS)

    Takagi, Shu; , Satoshi, II; Shiozaki, Seiji; Shimamoto, Norio; Sugiyama, Kazuyasu; Matsumoto, Yoichiro

    2012-11-01

    Thrombosis is regarded as one of the most important diseases, which cause the myocardial and cerebral infarctions. The thrombus formation is strongly related to the multiscale coupling phenomena from molecular scale protein-protein interaction to continuum scale in blood flow. Initially, platelets start aggregate at the injured vessel wall, where von Willebrand Factor (vWF) is attached. The Glycoprotein, GPIb- α, on platelet membrane starts showing ligand-receptor interaction with this vWF and platelets start aggregating around this spot. In the present study, multiscale coupling method is developed to simulate the initial stage of thrombus formation. In this method, the molecular scale interactions between vWF and GPIb- α is solve using the stochastic Monte Carlo simulations and the binding force at each computational cell is calculated. Then the force is directly coupled with the continuum scale simulation using finite different method. The results illustrate that fluctuation given by the motion of red blood cells plays an important role for the platelets to adhere to the injured vessel walls.

  18. Left atrial giant thrombus infected by Escherichia Coli. Case report

    PubMed Central

    Dedeilias, Panagiotis; Roussakis, Antonios; Koletsis, Efstratios N; Zervakis, Dimitrios; Hountis, Panagiotis; Prokakis, Christos; Balaka, Christina; Bolos, Konstantinos

    2008-01-01

    Background Left atrial thrombi are mostly related to mitral valve disease. The differential diagnosis of clots and myxomas in the left atrium is mostly based on echocardiography. Infection of intracardiac thrombi is extremely rare and mostly reported in ventricular clots or aneurysms following myocardial infarction. Case presentation We present the case of a 65 year old female with a history of mitral valve disease and chronic atrial fibrillation who suffered repeated embolic strokes and a giant infected clot in the left atrium. Although the patient underwent prompt surgery with removal of the clot and valve replacement the complication of septic emboli to the CNS led her to death. To the best of our knowledge this is the second report of an infected left atrial thrombus. Conclusion The case is a representative example of a neglected and undertreated patient with catastrophic consequences. Anticoagulant therapy in patients with mitral valve disease and atrial fibrillation should be applied according the currently available guidelines and standards in order to avoid analogous paradigms in the future. Mitral valve substitution should be considered in patients with mitral valve disease presenting thromboembolic complications. Surgery should be considered as the treatment of choice in cases of organized left atrial thrombus and suspected tumor or infected mass. PMID:18433486

  19. Total Mechanical Unloading Minimizes Metabolic Demand of Left Ventricle and Dramatically Reduces Infarct Size in Myocardial Infarction

    PubMed Central

    Kakino, Takamori; Arimura, Takahiro; Sakamoto, Takafumi; Nishikawa, Takuya; Sakamoto, Kazuo; Ikeda, Masataka; Kishi, Takuya; Ide, Tomomi; Sunagawa, Kenji

    2016-01-01

    Background Left ventricular assist device (LVAD) mechanically unloads the left ventricle (LV). Theoretical analysis indicates that partial LVAD support (p-LVAD), where LV remains ejecting, reduces LV preload while increases afterload resulting from the elevation of total cardiac output and mean aortic pressure, and consequently does not markedly decrease myocardial oxygen consumption (MVO2). In contrast, total LVAD support (t-LVAD), where LV no longer ejects, markedly decreases LV preload volume and afterload pressure, thereby strikingly reduces MVO2. Since an imbalance in oxygen supply and demand is the fundamental pathophysiology of myocardial infarction (MI), we hypothesized that t-LVAD minimizes MVO2 and reduces infarct size in MI. The purpose of this study was to evaluate the differential impact of the support level of LVAD on MVO2 and infarct size in a canine model of ischemia-reperfusion. Methods In 5 normal mongrel dogs, we examined the impact of LVAD on MVO2 at 3 support levels: Control (no LVAD support), p-LVAD and t-LVAD. In another 16 dogs, ischemia was induced by occluding major branches of the left anterior descending coronary artery (90 min) followed by reperfusion (300 min). We activated LVAD from the beginning of ischemia until 300 min of reperfusion, and compared the infarct size among 3 different levels of LVAD support. Results t-LVAD markedly reduced MVO2 (% reduction against Control: -56 ± 9%, p<0.01) whereas p-LVAD did less (-21 ± 14%, p<0.05). t-LVAD markedly reduced infarct size compared to p-LVAD (infarct area/area at risk: Control; 41.8 ± 6.4, p-LVAD; 29.1 ± 5.6 and t-LVAD; 5.0 ± 3.1%, p<0.01). Changes in creatine kinase-MB paralleled those in infarct size. Conclusions Total LVAD support that minimizes metabolic demand maximizes the benefit of LVAD in the treatment of acute myocardial infarction. PMID:27124411

  20. Selective endothelin A receptor antagonism with sitaxentan reduces neointimal lesion size in a mouse model of intraluminal injury

    PubMed Central

    Duthie, Karolina M; Hadoke, Patrick W F; Kirkby, Nicholas S; Miller, Eileen; Ivy, Jessica R; McShane, John F; Lim, Win Gel; Webb, David J

    2015-01-01

    Background and Purpose Endothelin (ET) receptor antagonism reduces neointimal lesion formation in animal models. This investigation addressed the hypothesis that the selective ETA receptor antagonist sitaxentan would be more effective than mixed ETA/B receptor antagonism at inhibiting neointimal proliferation in a mouse model of intraluminal injury. Experimental Approach Antagonism of ETA receptors by sitaxentan (1–100 nM) was assessed in femoral arteries isolated from adult, male C57Bl6 mice using isometric wire myography. Neointimal lesion development was induced by intraluminal injury in mice receiving sitaxentan (ETA antagonist; 15 mg·kg−1·day−1), A192621 (ETB antagonist; 30 mg·kg−1·day−1), the combination of both antagonists or vehicle. Treatment began 1 week before, and continued for 28 days after, surgery. Femoral arteries were then harvested for analysis of lesion size and composition. Key Results Sitaxentan produced a selective, concentration-dependent parallel rightward shift of ET-1-mediated contraction in isolated femoral arteries. Sitaxentan reduced neointimal lesion size, whereas ETB and combined ETA/B receptor antagonism did not. Macrophage and α-smooth muscle actin content were unaltered by ET receptor antagonism but sitaxentan reduced the amount of collagen in lesions. Conclusions and Implications These results suggest that ETA receptor antagonism would be more effective than combined ETA/ETB receptor antagonism at reducing neointimal lesion formation. PMID:25598351

  1. Soluble epoxide hydrolase gene deletion improves blood flow and reduces infarct size after cerebral ischemia in reproductively senescent female mice

    PubMed Central

    Zuloaga, Kristen L.; Zhang, Wenri; Roese, Natalie E.; Alkayed, Nabil J.

    2015-01-01

    Soluble epoxide hydrolase (sEH), a key enzyme in the metabolism of vasodilatory epoxyeicosatrienoic acids (EETs), is sexually dimorphic, suppressed by estrogen, and contributes to underlying sex differences in cerebral blood flow and injury after cerebral ischemia. We tested the hypothesis that sEH inhibition or gene deletion in reproductively senescent (RS) female mice would increase cerebral perfusion and decrease infarct size following stroke. RS (15–18 month old) and young (3–4 month old) female sEH knockout (sEHKO) mice and wild type (WT) mice were subjected to 45 min middle cerebral artery occlusion (MCAO) with laser Doppler perfusion monitoring. WT mice were treated with vehicle or a sEH inhibitor t-AUCB at the time of reperfusion and every 24 h thereafter for 3 days. Differences in regional cerebral blood flow were measured in vivo using optical microangiography (OMAG). Infarct size was measured 3 days after reperfusion. Infarct size and cerebral perfusion 24 h after MCAO were not altered by age. Both sEH gene deletion and sEH inhibition increased cortical perfusion 24 h after MCAO. Neither sEH gene deletion nor sEH inhibition reduced infarct size in young mice. However, sEH gene deletion, but not sEH inhibition of the hydrolase domain of the enzyme, decreased infarct size in RS mice. Results of these studies show that sEH gene deletion and sEH inhibition enhance cortical perfusion following MCAO and sEH gene deletion reduces damage after ischemia in RS female mice; however this neuroprotection in absent is young mice. PMID:25642188

  2. Reduced infarct size in neuroglobin-null mice after experimental stroke in vivo

    PubMed Central

    2012-01-01

    Background Neuroglobin is considered to be a novel important pharmacological target in combating stroke and neurodegenerative disorders, although the mechanism by which this protection is accomplished remains an enigma. We hypothesized that if neuroglobin is directly involved in neuroprotection, then permanent cerebral ischemia would lead to larger infarct volumes in neuroglobin-null mice than in wild-type mice. Methods Using neuroglobin-null mice, we estimated the infarct volume 24 hours after permanent middle cerebral artery occlusion using Cavalieri’s Principle, and compared the infarct volume in neuroglobin-null and wild-type mice. Neuroglobin antibody staining was used to examine neuroglobin expression in the infarct area of wild-type mice. Results Infarct volumes 24 hours after permanent middle cerebral artery occlusion were significantly smaller in neuroglobin-null mice than in wild-types (p < 0.01). Neuroglobin immunostaining of the penumbra area revealed no visible up-regulation of neuroglobin protein in ischemic wild-type mice when compared to uninjured wild-type mice. In uninjured wild-type mice, neuroglobin protein was seen throughout cortical layer II and sparsely in layer V. In contrast, no neuroglobin-immunoreactive neurons were observed in the aforementioned layers of the ischemia injured cortical area, or in the surrounding penumbra of ischemic wild-type mice. This suggests no selective sparing of neuroglobin expressing neurons in ischemia. Conclusions Neuroglobin-deficiency resulted in reduced tissue infarction, suggesting that, at least at endogenous expression levels, neuroglobin in itself is non-protective against ischemic injury. PMID:22901501

  3. Enhanced hydrogenation and reduced lattice distortion in size selected Pd-Ag and Pd-Cu alloy nanoparticles

    SciTech Connect

    Sengar, Saurabh K.; Mehta, B. R.; Kulriya, P. K.; Khan, S. A.

    2013-10-21

    Important correlation between valence band spectra and hydrogenation properties in Pd alloy nanoparticles is established by studying the properties of size selected and monocrystalline Pd, Ag, Cu, Pd-Ag, and Pd-Cu nanoparticles. The X-ray photoelectron spectroscopy and elastic recoil detection analysis show that size induced Pd4d centroid shift is related to enhanced hydrogenation with H/Pd ratio of 0.57 and 0.49 in Pd-Ag and Pd-Cu nanoparticles in comparison to reported bulk values of 0.2 and 0.1, respectively. Pd-alloy nanoparticles show lower hydrogen induced lattice distortion. The reduced distortion and higher hydrogen reactivity of Pd-alloy nanoparticles is important for numerous hydrogen related applications.

  4. Choice of Stimulus Range and Size Can Reduce Test-Retest Variability in Glaucomatous Visual Field Defects

    PubMed Central

    Swanson, William H.; Horner, Douglas G.; Dul, Mitchell W.; Malinovsky, Victor E.

    2014-01-01

    Purpose To develop guidelines for engineering perimetric stimuli to reduce test-retest variability in glaucomatous defects. Methods Perimetric testing was performed on one eye for 62 patients with glaucoma and 41 age-similar controls on size III and frequency-doubling perimetry and three custom tests with Gaussian blob and Gabor sinusoid stimuli. Stimulus range was controlled by values for ceiling (maximum sensitivity) and floor (minimum sensitivity). Bland-Altman analysis was used to derive 95% limits of agreement on test and retest, and bootstrap analysis was used to test the hypotheses about peak variability. Results Limits of agreement for the three custom stimuli were similar in width (0.72 to 0.79 log units) and peak variability (0.22 to 0.29 log units) for a stimulus range of 1.7 log units. The width of the limits of agreement for size III decreased from 1.78 to 1.37 to 0.99 log units for stimulus ranges of 3.9, 2.7, and 1.7 log units, respectively (F = 3.23, P < 0.001); peak variability was 0.99, 0.54, and 0.34 log units, respectively (P < 0.01). For a stimulus range of 1.3 log units, limits of agreement were narrowest with Gabor and widest with size III stimuli, and peak variability was lower (P < 0.01) with Gabor (0.18 log units) and frequency-doubling perimetry (0.24 log units) than with size III stimuli (0.38 log units). Conclusions Test-retest variability in glaucomatous visual field defects was substantially reduced by engineering the stimuli. Translational Relevance The guidelines should allow developers to choose from a wide range of stimuli. PMID:25371855

  5. Plasmodesmata formation and cell-to-cell transport are reduced in decreased size exclusion limit 1 during embryogenesis in Arabidopsis

    PubMed Central

    Xu, Min; Cho, Euna; Burch-Smith, Tessa M.; Zambryski, Patricia C.

    2012-01-01

    In plants, plasmodesmata (PD) serve as channels for micromolecular and macromolecular cell-to-cell transport. Based on structure, PD in immature tissues are classified into two types, simple and branched (X- and Y-shaped) or twinned. The maximum size of molecules capable of PD transport defines PD aperture, known as the PD size exclusion limit. Here we report an Arabidopsis mutation, decreased size exclusion limit1 (dse1), that exhibits reduced cell-to-cell transport of the small (524 Da) fluorescent tracer 8-hydroxypyrene-1,3,6-trisulfonic acid at the midtorpedo stage of embryogenesis. Correspondingly, the fraction of X- and Y-shaped and twinned PD was reduced in dse1 embryos compared with WT embryos at this stage, suggesting that the frequency of PD is related to transport capability. dse1 is caused by a point mutation in At4g29860 (previously termed TANMEI) at the last donor splice site of its transcript, resulting in alternative splicing in both the first intron and the last intron. AtDSE1 is a conserved eukaryotic 386-aa WD-repeat protein critical for Arabidopsis morphogenesis and reproduction. Similar to its homologs in mouse, null mutants are embryo-lethal. The weak loss-of-function mutant dse1 exhibits pleiotropic phenotypes, including retarded vegetative growth, delayed flowering time, dysfunctional male and female organs, and delayed senescence. Finally, silencing of DSE1 in Nicotiana benthamiana leaves leads to reduced movement of GFP fused to tobacco mosaic virus movement protein. Thus, DSE1 is important for regulating PD transport between plant cells. PMID:22411811

  6. Decoration of BiOI quantum size nanoparticles with reduced graphene oxide in enhanced visible-light-driven photocatalytic studies

    NASA Astrophysics Data System (ADS)

    Liu, Zhang; Xu, Weicheng; Fang, Jianzhang; Xu, Xiaoxin; Wu, Shuxing; Zhu, Ximiao; Chen, Zehua

    2012-10-01

    Herein, a reverse microemulsion route was developed to synthesize bismuth oxyiodide (BiOI) nanocrystals and reduced graphene oxide (RGO) nanocomposites as a highly efficient photocatalyst, and both the formation of BiOI and the reduction of RGO were achieved in situ in microemulsions simultaneously at low temperature (60 °C). The uniform nanocrystal size and structure were indicated by XRD, TEM, and the reduction of GO by ascorbic acid was evidenced by FTIR, XPS, and Raman spectra techniques. The enhanced photoactivity of RGO/BiOI nanocomposites under visible light was attributed to improved light absorption and efficient charge separation and transportation.

  7. Effect of GABA derivatives on the rate of thrombus formation, platelet aggregation, and plasma coagulation capacity in rats with experimental gestosis.

    PubMed

    Tyurenkov, I N; Perfilova, V N; Karamysheva, V I; Reznikova, L B; Mokrousov, I S; Mikhailova, L I; Berestovitskaya, V M; Vasil'eva, O S

    2014-12-01

    Experimental gestosis induced by replacement of drinking water with 1.8% NaCl promoted hypercoagulation, increased the rate and degree of platelet aggregation, and reduced clotting time in pregnant females. GABA derivatives, compounds RGPU-151, RGPU-152, and phenibut normalized parameters of hemostasis and platelet aggregation and the rate of thrombus formation in the animals. The efficiency of the test substances did not significantly differ from that of the reference drug sulodexide. PMID:25432276

  8. Platelet PI3Kβ and GSK3 regulate thrombus stability at a high shear rate.

    PubMed

    Laurent, Pierre-Alexandre; Séverin, Sonia; Hechler, Béatrice; Vanhaesebroeck, Bart; Payrastre, Bernard; Gratacap, Marie-Pierre

    2015-01-29

    Class IA phosphoinositide 3-kinase β (PI3Kβ) is considered a potential drug target in arterial thrombosis, which is a major cause of death worldwide. Here we show that a striking phenotype of mice with selective p110β deletion in the megakaryocyte lineage is thrombus instability at a high shear rate, which is an effect that is not detected in the absence of p110α in platelets. The high shear rate-dependent thrombus instability in the absence of p110β is observed both ex vivo and in vivo with the formation of platelet emboli. Moreover, PI3Kβ is required for the recruitment of new platelets to a growing thrombus when a pathological high shear is applied. Treatment of human blood with AZD6482, a selective PI3Kβ inhibitor, phenocopies p110β deletion in mouse platelets, which highlights the role of the kinase activity of p110β. Within the growing platelet thrombus, p110β inactivation impairs the activating phosphorylations of Akt and the inhibitory phosphorylation of GSK3. In accord with these data, pharmacologic inhibition of GSK3 restores thrombus stability. Thus, platelet PI3Kβ is not essential for thrombus growth and stability at normal arterial shear but has a specific and critical role in maintaining the integrity of the formed thrombus on elevation of shear rate, suggesting a potential risk of embolization on treatment with PI3Kβ inhibitors. PMID:25398937

  9. Numerical modeling of the flow in intracranial aneurysms: prediction of regions prone to thrombus formation

    PubMed Central

    Rayz, V.L.; Boussel, L.; Lawton, M.T.; Acevedo-Bolton, G.; Ge, L.; Young, W.L.; Higashida, R.T.; Saloner, D.

    2009-01-01

    The deposition of intralumenal thrombus in intracranial aneurysms adds a risk of thrombo-embolism over and above that posed by mass-effect and rupture. In addition to biochemical factors, hemodynamic factors that are governed by lumenal geometry and blood flow rates likely play an important role in the thrombus formation and deposition process. In this study, patient-specific computational fluid dynamics (CFD) models of blood flow were constructed from MRA data for three patients who had fusiform basilar aneurysms that were thrombus-free and then proceeded to develop intra-lumenal thrombus. In order to determine whether features of the flow fields could suggest which regions had an elevated potential for thrombus deposition, the flow was modeled in the baseline, thrombus-free geometries. Pulsatile flow simulations were carried out using patient-specific inlet flow conditions measured with MR velocimetry. Newtonian and non-Newtonian blood behavior was considered. A strong similarity was found between the intra-aneurysmal regions with CFD-predicted slow, recirculating flows and the regions of thrombus deposition observed in vivo in the follow-up MR studies. In two cases with larger aneurysms, the agreement between the low velocity zones and clotted off regions improved when non-Newtonian blood behavior was taken into account. A similarity was also found between the calculated low shear stress regions and the regions that were later observed to clot. PMID:18787954

  10. Using a Reduced Spot Size for Intensity-Modulated Proton Therapy Potentially Improves Salivary Gland-Sparing in Oropharyngeal Cancer

    SciTech Connect

    Water, Tara A. van de; Lomax, Antony J.; Bijl, Hendrik P.; Schilstra, Cornelis; Hug, Eugen B.; Langendijk, Johannes A.

    2012-02-01

    Purpose: To investigate whether intensity-modulated proton therapy with a reduced spot size (rsIMPT) could further reduce the parotid and submandibular gland dose compared with previously calculated IMPT plans with a larger spot size. In addition, it was investigated whether the obtained dose reductions would theoretically translate into a reduction of normal tissue complication probabilities (NTCPs). Methods: Ten patients with N0 oropharyngeal cancer were included in a comparative treatment planning study. Both IMPT plans delivered simultaneously 70 Gy to the boost planning target volume (PTV) and 54 Gy to the elective nodal PTV. IMPT and rsIMPT used identical three-field beam arrangements. In the IMPT plans, the parotid and submandibular salivary glands were spared as much as possible. rsIMPT plans used identical dose-volume objectives for the parotid glands as those used by the IMPT plans, whereas the objectives for the submandibular glands were tightened further. NTCPs were calculated for salivary dysfunction and xerostomia. Results: Target coverage was similar for both IMPT techniques, whereas rsIMPT clearly improved target conformity. The mean doses in the parotid glands and submandibular glands were significantly lower for three-field rsIMPT (14.7 Gy and 46.9 Gy, respectively) than for three-field IMPT (16.8 Gy and 54.6 Gy, respectively). Hence, rsIMPT significantly reduced the NTCP of patient-rated xerostomia and parotid and contralateral submandibular salivary flow dysfunction (27%, 17%, and 43% respectively) compared with IMPT (39%, 20%, and 79%, respectively). In addition, mean dose values in the sublingual glands, the soft palate and oral cavity were also decreased. Obtained dose and NTCP reductions varied per patient. Conclusions: rsIMPT improved sparing of the salivary glands and reduced NTCP for xerostomia and parotid and submandibular salivary dysfunction, while maintaining similar target coverage results. It is expected that rsIMPT improves quality

  11. Mercury induces proliferation and reduces cell size in vascular smooth muscle cells through MAPK, oxidative stress and cyclooxygenase-2 pathways

    SciTech Connect

    Aguado, Andrea; Galán, María; Zhenyukh, Olha; Wiggers, Giulia A.; Roque, Fernanda R.; Redondo, Santiago; Peçanha, Franck; Martín, Angela; Fortuño, Ana; Cachofeiro, Victoria; Tejerina, Teresa; Salaices, Mercedes; and others

    2013-04-15

    MAPK activation, oxidative stress and COX-2 expression. ► Inhibition of MAPK reduces HgCl{sub 2}-induced oxidative stress and COX-2 expression. ► Inhibition of MAPK, oxidative stress and COX-2 restores the altered cell proliferation and size.

  12. Impact of particle size distribution on rheological and textural properties of chocolate models with reduced fat content.

    PubMed

    Do, T-A L; Hargreaves, J M; Wolf, B; Hort, J; Mitchell, J R

    2007-11-01

    With an increasing consumption of lipids nowadays, decreasing the fat content in food products has become a trend. Chocolate is a fat-based suspension that contains about 30%wt fat. Reducing fat content causes an increase in the molten chocolate viscosity. This leads to 2 major issues: difficulties in the process and a loss of eating quality in the final product, reported to have poor in-mouth melting properties, remain hard, and difficult to swallow. Literature shows that optimizing the particle size distribution (PSD), that is, having one with an increased packing fraction, can decrease the viscosity of highly concentrated suspensions. This study focuses on the impact of the PSD and fat content on the rheological properties, melting behavior, and hardness of chocolate models (dispersions of sugar in fat). We show that optimizing the PSD while reducing the fat content to a critical amount (22%wt) can decrease the viscosity of the molten material and reduce the hardness of the crystallized chocolate models. Melting in the mouth, characterized by an in vitro collapse speed, is faster for the samples with an optimized PSD. The decrease in the viscosity by optimizing the PSD in systems with a constant fraction of medium phase is based on the decrease of interparticle contact, reducing the particle aggregates strength, and structure buildup during flow or meltdown. In its crystallized state, the particle network is less interconnected, providing less resistance to breakage and meltdown. PMID:18034724

  13. Lnk regulates integrin αIIbβ3 outside-in signaling in mouse platelets, leading to stabilization of thrombus development in vivo

    PubMed Central

    Takizawa, Hitoshi; Nishimura, Satoshi; Takayama, Naoya; Oda, Atsushi; Nishikii, Hidekazu; Morita, Yohei; Kakinuma, Sei; Yamazaki, Satoshi; Okamura, Satoshi; Tamura, Noriko; Goto, Shinya; Sawaguchi, Akira; Manabe, Ichiro; Takatsu, Kiyoshi; Nakauchi, Hiromitsu; Takaki, Satoshi; Eto, Koji

    2009-01-01

    The nature of the in vivo cellular events underlying thrombus formation mediated by platelet activation remains unclear because of the absence of a modality for analysis. Lymphocyte adaptor protein (Lnk; also known as Sh2b3) is an adaptor protein that inhibits thrombopoietin-mediated signaling, and as a result, megakaryocyte and platelet counts are elevated in Lnk–/– mice. Here we describe an unanticipated role for Lnk in stabilizing thrombus formation and clarify the activities of Lnk in platelets transduced through integrin αIIbβ3–mediated outside-in signaling. We equalized platelet counts in wild-type and Lnk–/– mice by using genetic depletion of Lnk and BM transplantation. Using FeCl3- or laser-induced injury and in vivo imaging that enabled observation of single platelet behavior and the multiple steps in thrombus formation, we determined that Lnk is an essential contributor to the stabilization of developing thrombi within vessels. Lnk–/– platelets exhibited a reduced ability to fully spread on fibrinogen and mediate clot retraction, reduced tyrosine phosphorylation of the β3 integrin subunit, and reduced binding of Fyn to integrin αIIbβ3. These results provide new insight into the mechanism of αIIbβ3-based outside-in signaling, which appears to be coordinated in platelets by Lnk, Fyn, and integrins. Outside-in signaling modulators could represent new therapeutic targets for the prevention of cardiovascular events. PMID:20038804

  14. Short-term pretreatment with atorvastatin attenuates left ventricular dysfunction, reduces infarct size and apoptosis in acute myocardial infarction rats

    PubMed Central

    Chen, Tie-Long; Zhu, Guang-Li; He, Xiao-Long; Wang, Jian-An; Wang, Yu; Qi, Guo-An

    2014-01-01

    Background: Atorvastatin showed a number of cardiovascular benefits, however, the role and underlying molecular mechanisms of short-term atorvastatin-mediated protection remain unclear. Methods: 30 rats were randomly divided into 3 groups: sham group, acute myocardial infarction model group and atorvastatin group. The rats of acute myocardial infarction model were established by ligation of the left anterior descending of coronary arteries. Before surgery, rats in the atorvastatin group received 20 mg/kg/d atorvastatin for 7 days in atorvastatin group. After 4 hours of model established, changes in hemodynamics parameters were recorded and myocardial infarct size was achieved by Evans blue-TTC staining. Myocardium apoptosis was evaluated by TUNEL. The expression of FAS, FAS-L, Bcl-2, Bax, p-BAD, Caspase-8 and Caspase-3 in myocardium were examined by Western blot. Results: In the atorvastatin group, left ventricular function was elevated and infarct size was decreased compared with the model group. Moreover, in the atorvastatin group, the cell apoptosis index was reduced in response to myocardial infarction. The expressions of Bcl-2 were increased and Bax, p-BAD, Fas, Fas-L, caspase-8 and caspase-3 in myocardium were decreased in atorvastatin group. Conclusions: Short-term atorvastatin pretreatment restored left ventricular function and limited infarct size in acute myocardial infarction, which were associated with reduction of the apoptosis in myocardium through Bcl-2 and Fas pathway. PMID:25663976

  15. Free floating left atrial ball thrombus: a rare cause of stroke.

    PubMed

    Rider, Oliver J; Malhotra, Aneil; Newton, James D

    2013-10-01

    In the setting of mitral valve stenosis and atrial fibrillation, left atrial ball thrombus is a rare but recognized cause of stroke and can occur even in the presence of therapeutic anticoagulation. This case report highlights the need for echocardiography to rule out treatable cardioembolic substrates for stroke. We report a case of cardioembolic stroke as a result of free floating left atrial ball thrombus presenting as a complication of rheumatic mitral valve disease. This case highlights that, in all patients with a history of structural heart disease, atrial fibrillation, or rheumatic fever, prompt cardiac ultrasound to exclude free floating atrial thrombus is essential. PMID:22959106

  16. No-Reflow Phoenomenon by Intracoronary Thrombus in Acute Myocardial Infarction

    PubMed Central

    2016-01-01

    Recently, percutaneous coronary intervention has been the treatment of choice in most acute myocardial infarction cases. Although the results of percutaneous coronary interventions have ben good, the no-reflow phenomenon and distal embolization of intracoronary thrombus are still major problems even after successful interventions. In this article, we will briefly review the deleterious effects of no-reflow and distal embolization of intracoronary thrombus during percutaneous coronary interventions. The current trials focused on the prevention and treatment of the no-reflow phenomenon and intracoronary thrombus. PMID:26865998

  17. Local delivery of soluble TNF-alpha receptor 1 gene reduces infarct size following ischemia/reperfusion injury in rats.

    PubMed

    Sugano, Masahiro; Hata, Tomoji; Tsuchida, Keiko; Suematsu, Nobuhiro; Oyama, Jun-Ichi; Satoh, Shinji; Makino, Naoki

    2004-11-01

    Apoptosis in the myocardium is linked to ischemia/reperfusion injury, and TNF-alpha induces apoptosis in cardiomyocytes. A significant amount of TNF-alpha is detected after ischemia and reperfusion. Soluble TNF-alpha receptor 1 (sTNFR1) is an extracellular domain of TNF-alpha receptor 1 and is an antagonist to TNF-alpha. In the present study, we examined the effects of sTNFR1 on infarct size in acute myocardial infarction (AMI) following ischemia/reperfusion. Male Wistar rats were subjected to left coronary artery (LCA) ligation. After 30 min of LCA occlusion, the temporary ligature on the LCA was released and blood flow was restored. Immediately after reperfusion, a total of 200 microg of sTNFR1 or LacZ plasmid was injected into three different sites of the left ventricular wall. At 6 h, 1 and 2 days after reperfusion, the TNF-alpha bioactivity in the myocardium was significantly higher in rats receiving LacZ plasmid than in sham-operated rats, whereas sTNFR1 plasmid significantly suppressed the increase in the TNF-alpha bioactivity. The sTNFR1 plasmid significantly reduced DNA fragmentation and caspase activity compared to the LacZ plasmid. Finally, the sTNFR1 expression-plasmid treatment significantly reduced the area of myocardial infarction at 2 days after ischemia/reperfusion compared to LacZ plasmid. In conclusion, the TNF-alpha bioactivity in the heart increased from the early stage of ischemia/reperfusion, and this increase was thought to contribute in part to the increased area of myocardial infarction. Suppression of TNF-alpha bioactivity with the sTNFR1 plasmid reduced the infarct size in AMI following ischemia and reperfusion. PMID:15646033

  18. Facile Fabrication of Lubricant-Infused Wrinkling Surface for Preventing Thrombus Formation and Infection.

    PubMed

    Yuan, Shuaishuai; Luan, Shifang; Yan, Shunjie; Shi, Hengchong; Yin, Jinghua

    2015-09-01

    Despite the advanced modern biotechniques, thrombosis and bacterial infection of biomedical devices remain common complications that are associated with morbidity and mortality. Most antifouling surfaces are in solid form and cannot simultaneously fulfill the requirements for antithrombosis and antibacterial efficacy. In this work, we present a facile strategy to fabricate a slippery surface. This surface is created by combining photografting polymerization with osmotically driven wrinkling that can generate a coarse morphology, and followed by infusing with fluorocarbon liquid. The lubricant-infused wrinkling slippery surface can greatly prevent protein attachment, reduce platelet adhesion, and suppress thrombus formation in vitro. Furthermore, E. coli and S. aureus attachment on the slippery surfaces is reduced by ∼98.8% and ∼96.9% after 24 h incubation, relative to poly(styrene-b-isobutylene-b-styrene) (SIBS) references. This slippery surface is biocompatible and has no toxicity to L929 cells. This surface-coating strategy that effectively reduces thrombosis and the incidence of infection will greatly decrease healthcare costs. PMID:26268298

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

    PubMed

    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. PMID:24106270

  20. RhoG Protein Regulates Platelet Granule Secretion and Thrombus Formation in Mice*

    PubMed Central

    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.

    2013-01-01

    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. PMID:24106270

  1. Resolution of Internal Carotid Arterial Thrombus by the Thrombolytic Action of Dabigatran: A first case report.

    PubMed

    Akiyama, Hisanao; Hoshino, Masashi; Shimizu, Takahiro; Hasegawa, Yasuhiro

    2016-04-01

    Non-vitamin K antagonist oral anticoagulants (NOACs) have been reported to cause resolution of intracardiac thrombus, but there have been no reported cases of internal carotid arterial thrombus resolution.We report a case of a 76-year-old man in whom an internal carotid arterial thrombus resolved after administration of the NOAC dabigatran at a dose of 110 mg twice daily.This is the first reported case of carotid arterial thrombus resolution after oral intake of NOAC (direct thrombin and factor Xa inhibitors), to the best of our knowledge.We conclude that this case had major clinical significance because it might represent one of the multiple effects of NOACs. PMID:27057852

  2. Mechano-rheological properties of the murine thrombus determined via nanoindentation and finite element modeling.

    PubMed

    Slaboch, Constance L; Alber, Mark S; Rosen, Elliot D; Ovaert, Timothy C

    2012-06-01

    Deep vein thrombosis, pulmonary embolism, and abdominal aortic aneurysms are blood-related diseases that represent a major public health problem. These diseases are characterized by the formation of a thrombus (i.e., blood clot) that either blocks a major artery or causes an aortic rupture. Identifying the mechanical properties of thrombi can help determine when these incidents will occur. In this investigation, a murine thrombus, formed from platelet-rich plasma, calcium, and thrombin, was nanoindented and the elastic modulus was estimated via elastic contact theory. This information was used as input to an inverse finite element simulation, which determined optimal values for the elastic modulus and viscosity of the thrombus using a viscoelastic material model. A sensitivity analysis was also performed to determine which material parameters have the greatest affect on the simulation. Results from this investigation demonstrate the feasibility of the mechanical characterization of a murine thrombus using nanoindentation. PMID:22520420

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

    SciTech Connect

    Mizandari, Malkhaz; Ao, Guokun; Zhang Yaojun; Feng Xi; Shen Qiang; Chen Minshan; Lau, Wan Yee; Nicholls, Joanna; Jiao Long; Habib, Nagy

    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.

  4. Une angiocholite secondaire à un thrombus tumoral d'une tumeur neuroendocrine primitive du foie

    PubMed Central

    Baba, Hicham; Allaoui, Mohamed; Elfahssi, Mohammed; Bounaim, Ahmed; Ali, Abdelmounaim Ait; Oukabli, Mohamed; Sair, Khalid; Zentar, Aziz

    2015-01-01

    Nous rapportons le cas exceptionnel d'une patiente de 54 ans prise en charge pour une angiocholite due à un thrombus tumoral, d'une tumeur neuroendocrine primitive (TNE Ive) du foie, dans la voie biliaire principale. PMID:26966504

  5. [Successful direct thrombin inhibitor treatment of a left atrial appendage thrombus developed under rivaroxaban therapy].

    PubMed

    Szegedi, Nándor; Gellér, László; Tahin, Tamás; Merkely, Béla; Széplaki, Gábor

    2016-01-24

    The authors present the history of a 62-year-old man on continuous rivaroxaban therapy who was scheduled for pulmonary vein isolation due to persistent atrial fibrillation. Preoperative transesophageal echocardiography detected the presence of left atrial appendage thrombus. Thrombophilia tests showed that the patient was heterozygous carrier of the methylene-tetrahydrofolate reductase gene mutation. The authors hypothesized that a direct thrombin inhibitor might exert a more appropriate effect against thrombosis in this case and, therefore, a switch to dabigatran was performed. After two months of anticoagulation with the direct thrombin inhibitor and folic acid supplementation the thrombus resolved. The authors underline that thrombus formation may develop in atrial fibrillation even if the patient is adequately treated with rivaroxaban. This case suggests, that methylene-tetrahydrofolate reductase gene mutation may modulate the efficacy of direct Xa factor inhibitors. According to this case history, dabigatran may be an effective therapeutic option in resolving established thrombus. PMID:26772828

  6. Use of apixaban for an elderly patient with left atrial thrombus

    PubMed Central

    Dobashi, Shintaro; Fujino, Tadashi; Ikeda, Takanori

    2014-01-01

    An 86-year-old man had long-standing persistent atrial fibrillation, but had not received any anticoagulants. Transthoracic echocardiography revealed a large thrombus formation in the left atrium. We hesitated to use the conventional anticoagulant, warfarin, because he was very old and had dementia. We decided to resolve the thrombus at our outpatient clinic. He was started on the novel oral anticoagulant, apixaban, 2.5 mg twice daily, which is a direct factor Xa (FXa) inhibitor. After 11 weeks on that therapy, the thrombus formation had almost resolved. During oral anticoagulant therapy, no serious bleeding complications, systemic embolisms or strokes were noted. To the best of our knowledge, we are the first to report that apixaban (5 mg/day) can possibly resolve a thrombus formation in the left atrium. PMID:24962484

  7. Eyelid varix with phlebolith formation, thrombus recanalization, and early intravascular papillary endothelial hyperplasia.

    PubMed

    Zakka, Fouad R; Jakobiec, Frederick A; Thakker, Manoj M

    2011-01-01

    An asymptomatic, bluish-gray, movable, raised, and firm left upper eyelid mass had been present for 8 months in an 82-year-old woman. Histopathologic examination revealed a lesion restricted to the dermis and composed in part of a calcific nodule that was circumscribed by an acellular fibrous capsule. An adjacent nodule exhibited proliferating endothelial cells invading a fresh thrombus. Immunohistochemical staining revealed positivity for CD31, CD34, and CD68; D2-40 was negative, ruling out a lymphatic origin. Masson trichrome and elastic staining of deeper sections revealed recanalization of an earlier thrombus; surviving elastic fibers were discovered in the outer wall, establishing a venous source. This is the first reported case of 3 microscopically discernible events (old phlebolith, fresh intravascular endothelial hyperplasia invading a thrombus, and labyrinthine recanalization of a temporally more remote thrombus) in an eyelid varix. The clinical differential diagnosis is reviewed. PMID:20724862

  8. Role of plant residues in determining temporal patterns of the activity, size, and structure of nitrate reducer communities in soil.

    PubMed

    Chèneby, D; Bru, D; Pascault, N; Maron, P A; Ranjard, L; Philippot, L

    2010-11-01

    The incorporation of plant residues into soil not only represents an opportunity to limit soil organic matter depletion resulting from cultivation but also provides a valuable source of nutrients such as nitrogen. However, the consequences of plant residue addition on soil microbial communities involved in biochemical cycles other than the carbon cycle are poorly understood. In this study, we investigated the responses of one N-cycling microbial community, the nitrate reducers, to wheat, rape, and alfalfa residues for 11 months after incorporation into soil in a field experiment. A 20- to 27-fold increase in potential nitrate reduction activity was observed for residue-amended plots compared to the nonamended plots during the first week. This stimulating effect of residues on the activity of the nitrate-reducing community rapidly decreased but remained significant over 11 months. During this period, our results suggest that the potential nitrate reduction activity was regulated by both carbon availability and temperature. The presence of residues also had a significant effect on the abundance of nitrate reducers estimated by quantitative PCR of the narG and napA genes, encoding the membrane-bound and periplasmic nitrate reductases, respectively. In contrast, the incorporation of the plant residues into soil had little impact on the structure of the narG and napA nitrate-reducing community determined by PCR-restriction fragment length polymorphism (RFLP) fingerprinting. Overall, our results revealed that the addition of plant residues can lead to important long-term changes in the activity and size of a microbial community involved in N cycling but with limited effects of the type of plant residue itself. PMID:20833788

  9. Systematic adjustment of charge densities and size of polyglycerol amines reduces cytotoxic effects and enhances cellular uptake.

    PubMed

    Hellmund, Markus; Achazi, Katharina; Neumann, Falko; Thota, Bala N S; Ma, Nan; Haag, Rainer

    2015-11-01

    Excessive cationic charge density of polyplexes during cellular uptake is still a major hurdle in the field of non-viral gene delivery. The most efficient cationic vectors such as polyethylene imine (PEI) or polyamidoamine (PAMAM) can be highly toxic and may induce strong side effects due to their high cationic charge densities. Alternatives like polyethylene glycol (PEG) are used to 'shield' these charges and thus to reduce the cytotoxic effects known for PEI/PEG-core-shell architectures. In this study, we compared the ability of hyperbranched polyglycerol amines (hPG amines) with different amine densities and molecular weights as non-viral cationic vectors for DNA delivery. By adjusting the hydroxyl to amine group ratio on varying molecular weights, we were able to perform a systematic study on the cytotoxic effects caused by the effective charge density in correlation to size. We could demonstrate that carriers with moderate charge density have a higher potential for effective DNA delivery as compared to high/low charged ones independent of their size, but the final efficiency can be optimized by the molecular weight. We analyzed the physicochemical properties and cellular uptake capacity as well as the cytotoxicity and transfection efficiency of these new vector systems. PMID:26244171

  10. Continuous nicotinamide administration improves behavioral recovery and reduces lesion size following bilateral frontal controlled cortical impact injury.

    PubMed

    Vonder Haar, Cole; Anderson, Gail D; Hoane, Michael R

    2011-10-31

    Previous research has demonstrated considerable preclinical efficacy of nicotinamide (NAM; vitamin B(3)) in animal models of TBI with systemic dosing at 50 and 500 mg/kg yielding improvements on sensory, motor, cognitive and histological measures. The current study aimed to utilize a more specific dosing paradigm in a clinically relevant delivery mechanism: continuously secreting subcutaneous pumps. A bilateral frontal controlled cortical impact (CCI) or sham surgery was performed and rats were treated with NAM (150 mg/kg day) or saline (1 ml/kg) pumps 30 min after CCI, continuing until seven days post-CCI. Rats were given a loading dose of NAM (50mg/kg) or saline (1 ml/kg) following pump implant. Rats received behavioral testing (bilateral tactile adhesive removal, locomotor placing task and Morris water maze) starting on day two post-CCI and were sacrificed at 31 days post-CCI and brains were stained to examine lesion size. NAM-treated rats had reductions in sensory, motor and cognitive behavioral deficits compared to vehicle-treated rats. Specifically, NAM-treated rats significantly improved on the bilateral tactile adhesive removal task, locomotor placing task and the reference memory paradigm of the Morris water maze. Lesion size was also significantly reduced in the NAM-treated group. The results from this study indicate that at the current dose, NAM produces beneficial effects on recovery from a bilateral frontal brain injury and that it may be a relevant compound to be explored in human studies. PMID:21704653

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

    PubMed Central

    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

  12. A spatio-temporal model for spontaneous thrombus formation in cerebral aneurysms.

    PubMed

    Malaspinas, O; Turjman, A; Ribeiro de Sousa, D; Garcia-Cardena, G; Raes, M; Nguyen, P-T T; Zhang, Y; Courbebaisse, G; Lelubre, C; Zouaoui Boudjeltia, K; Chopard, B

    2016-04-01

    We propose a new numerical model to describe thrombus formation in cerebral aneurysms. This model combines CFD simulations with a set of bio-mechanical processes identified as being the most important to describe the phenomena at a large space and time scales. The hypotheses of the model are based on in vitro experiments and clinical observations. We document that we can reproduce very well the shape and volume of patient specific thrombus segmented in giant aneurysms. PMID:26802480

  13. Computational Study of Thrombus Formation and Clotting Factor Effects under Venous Flow Conditions.

    PubMed

    Govindarajan, Vijay; Rakesh, Vineet; Reifman, Jaques; Mitrophanov, Alexander Y

    2016-04-26

    A comprehensive understanding of thrombus formation as a physicochemical process that has evolved to protect the integrity of the human vasculature is critical to our ability to predict and control pathological states caused by a malfunctioning blood coagulation system. Despite numerous investigations, the spatial and temporal details of thrombus growth as a multicomponent process are not fully understood. Here, we used computational modeling to investigate the temporal changes in the spatial distributions of the key enzymatic (i.e., thrombin) and structural (i.e., platelets and fibrin) components within a growing thrombus. Moreover, we investigated the interplay between clot structure and its mechanical properties, such as hydraulic resistance to flow. Our model relied on the coupling of computational fluid dynamics and biochemical kinetics, and was validated using flow-chamber data from a previous experimental study. The model allowed us to identify the distinct patterns characterizing the spatial distributions of thrombin, platelets, and fibrin accumulating within a thrombus. Our modeling results suggested that under the simulated conditions, thrombin kinetics was determined predominantly by prothrombinase. Furthermore, our simulations showed that thrombus resistance imparted by fibrin was ∼30-fold higher than that imparted by platelets. Yet, thrombus-mediated bloodflow occlusion was driven primarily by the platelet deposition process, because the height of the platelet accumulation domain was approximately twice that of the fibrin accumulation domain. Fibrinogen supplementation in normal blood resulted in a nonlinear increase in thrombus resistance, and for a supplemented fibrinogen level of 48%, the thrombus resistance increased by ∼2.7-fold. Finally, our model predicted that restoring the normal levels of clotting factors II, IX, and X while simultaneously restoring fibrinogen (to 88% of its normal level) in diluted blood can restore fibrin generation to

  14. Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes

    SciTech Connect

    Hashimoto, Takeshi; Yokokawa, Takumi; Endo, Yuriko; Iwanaka, Nobumasa; Higashida, Kazuhiko; Taguchi, Sadayoshi

    2013-10-11

    Highlights: •Long-term hypoxia decreased the size of LDs and lipid storage in 3T3-L1 adipocytes. •Long-term hypoxia increased basal lipolysis in 3T3-L1 adipocytes. •Hypoxia decreased lipid-associated proteins in 3T3-L1 adipocytes. •Hypoxia decreased basal glucose uptake and lipogenic proteins in 3T3-L1 adipocytes. •Hypoxia-mediated lipogenesis may be an attractive therapeutic target against obesity. -- Abstract: Background: A previous study has demonstrated that endurance training under hypoxia results in a greater reduction in body fat mass compared to exercise under normoxia. However, the cellular and molecular mechanisms that underlie this hypoxia-mediated reduction in fat mass remain uncertain. Here, we examine the effects of modest hypoxia on adipocyte function. Methods: Differentiated 3T3-L1 adipocytes were incubated at 5% O{sub 2} for 1 week (long-term hypoxia, HL) or one day (short-term hypoxia, HS) and compared with a normoxia control (NC). Results: HL, but not HS, resulted in a significant reduction in lipid droplet size and triglyceride content (by 50%) compared to NC (p < 0.01). As estimated by glycerol release, isoproterenol-induced lipolysis was significantly lowered by hypoxia, whereas the release of free fatty acids under the basal condition was prominently enhanced with HL compared to NC or HS (p < 0.01). Lipolysis-associated proteins, such as perilipin 1 and hormone-sensitive lipase, were unchanged, whereas adipose triglyceride lipase and its activator protein CGI-58 were decreased with HL in comparison to NC. Interestingly, such lipogenic proteins as fatty acid synthase, lipin-1, and peroxisome proliferator-activated receptor gamma were decreased. Furthermore, the uptake of glucose, the major precursor of 3-glycerol phosphate for triglyceride synthesis, was significantly reduced in HL compared to NC or HS (p < 0.01). Conclusion: We conclude that hypoxia has a direct impact on reducing the triglyceride content and lipid droplet size via

  15. Methods to Determine the Lagrangian Shear Experienced by Platelets during Thrombus Growth

    PubMed Central

    Pinar, Isaac P.; Arthur, Jane F.; Andrews, Robert K.; Gardiner, Elizabeth E.; Ryan, Kris; Carberry, Josie

    2015-01-01

    Platelets can become activated in response to changes in flow-induced shear; however, the underlying molecular mechanisms are not clearly understood. Here we present new techniques for experimentally measuring the flow-induced shear rate experienced by platelets prior to adhering to a thrombus. We examined the dynamics of blood flow around experimentally grown thrombus geometries using a novel combination of experimental (ex vivo) and numerical (in silico) methodologies. Using a microcapillary system, platelet aggregate formation was analysed at elevated shear rates in the presence of coagulation inhibitors, where thrombus formation is predominantly platelet-dependent. These approaches permit the resolution and quantification of thrombus parameters at the scale of individual platelets (2 μm) in order to quantify real time thrombus development. Using our new techniques we can correlate the shear rate experienced by platelets with the extent of platelet adhesion and aggregation. The techniques presented offer the unique capacity to determine the flow properties for a temporally evolving thrombus field in real time. PMID:26660525

  16. Less invasive treatment option for renal carcinoma with venous tumor thrombus

    PubMed Central

    Nagy, Zoltán; Pánovics, József; Szendrői, Attila; Szász, Attila Marcell; Harsányi, László; Romics, Imre

    2014-01-01

    Aim To retrospectively analyze patients treated by renal tumor and venous tumor thrombus (VTT) removal and to introduce a less stressful and safer surgical method without thoracotomy in Neves level 3 cases. Methods From 2002 to 2011, 33 patients underwent surgery for renal cell cancer combined with tumor thrombus of the inferior vena cava. Preoperative symptoms, tumor-node-metastasis classification of tumors, thrombus extension classified by Neves and Zincke system, types of surgical interventions, complications, postoperative management, and survival results were analyzed. Results Ten patients had level 1, 17 had level 2, and 6 had level 3 thrombi according to Neves and Zincke. In 5 patients with level 3 thrombi, the liver was mobilized without thoracotomy and in 1 patient endoluminal occlusion was utilized. There was no intraoperative mortality. The median survival time of 10 patients who died during follow-up period was 36.6 months (range, 1-116 months). Conclusion Renal cell cancer complicated with tumor thrombus without metastasis can be curable by performing a complete resection. The thrombus level determines the surgical approach and method. Our results confirm that level 3 caval vein tumor thrombus can be safely surgically treated by laparotomy with liver mobilization. Thoracotomy, use of cardiopulmonary bypass, and hypothermic circulatory arrest can be avoided with adequate liver- and vascular surgery methods. PMID:24891285

  17. Bilirubin Levels and Thrombus Burden in Patients With ST-Segment Elevation Myocardial Infarction.

    PubMed

    Hamur, Hikmet; Duman, Hakan; Bakirci, Eftal Murat; Kucuksu, Zafer; Demirelli, Selami; Kalkan, Kamuran; Degirmenci, Husnu

    2016-07-01

    We investigated whether serum bilirubin level (a marker of heme oxygenase activity) is a predictor of thrombus burden in patients with acute myocardial infarction. Patients (n = 229; male 72.9%; mean age 63 ± 13.4 years) who were admitted with ST-segment elevation myocardial infarction (STEMI) were enrolled. Patients were divided into 2 groups. Group 1 was defined as low thrombus burden and group 2 was defined as high thrombus burden. Patients with high thrombus burden had higher total bilirubin levels (14.4 [4.3-22.9] vs 7.7 [2.4-20.3] µmol/L, P ≤ .001), (0.84 [0.25-1.34] vs 0.45 [0.14-1.19] mg/dL P ≤ .001) and direct bilirubin levels (3.1 [2.1-8.4] vs 1.7 [0.5-6.5] µmol/L, P ≤ .001), (0.18 [0.03-0.49] vs 0.10 [0.03-0.38] mg/dL, P ≤ .001). At multivariate analysis, total bilirubin (odds ratio: 1.05, 95% confidence interval: 1.03-1.08, P ≤ .001) was the independent predictor of high thrombus burden. In conclusion, total bilirubin level is independently associated with high thrombus burden in patients with STEMI. PMID:26339042

  18. Histological and Biomechanical Changes in a Mouse Model of Venous Thrombus Remodeling

    PubMed Central

    Lee, Y.-U.; Lee, A.Y.; Humphrey, J.D.; Rausch, M.K.

    2016-01-01

    BACKGROUND Deep vein thrombosis and the risk of pulmonary embolism are significant causes of morbidity and mortality. Much remains unclear, however, about the mechanisms by which a venous thrombus initiates, progresses, or resolves. In particular, there is a pressing need to characterize the evolving mechanical properties of a venous thrombus for its mechanical integrity is fundamental to many disease sequelae. OBJECTIVE The primary goal of the present study was to initiate a correlation between evolving histological changes and biomechanical properties of venous thrombus. METHODS We employed an inferior vena cava ligation model in mice to obtain cylindrical samples of thrombus that were well suited for mechanical testing and that could be explanted at multiple times following surgery. Using uniaxial micro-mechanical testing, we collected stress-stretch data that were then fit with a microstructurally-inspired material model before submitting the samples to immunohistological examination. RESULTS We found that venous thrombus underwent a radially inward directed replacement of fibrin with collagen between 2 weeks and 4 weeks of development, which was accompanied by the infiltration of inflammatory and mesenchymal cells. These histological changes correlated with a marked increase in material stiffness. CONCLUSIONS We demonstrated that 2 to 4 week old venous thrombus undergoes drastic remodeling from a fibrin-dominated mesh to a collagen-dominated microstructure and that these changes are accompanied by dramatic changes in biomechanical behavior. PMID:26444224

  19. A systems approach to hemostasis: 1. The interdependence of thrombus architecture and agonist movements in the gaps between platelets

    PubMed Central

    Welsh, John D.; Stalker, Timothy J.; Voronov, Roman; Muthard, Ryan W.; Tomaiuolo, Maurizio; Diamond, Scott L.

    2014-01-01

    Hemostatic thrombi develop a characteristic architecture in which a core of highly activated platelets is covered by a shell of less-activated platelets. Here we have used a systems biology approach to examine the interrelationship of this architecture with transport rates and agonist distribution in the gaps between platelets. Studies were performed in mice using probes for platelet accumulation, packing density, and activation plus recently developed transport and thrombin activity probes. The results show that intrathrombus transport within the core is much slower than within the shell. The region of slowest transport coincides with the region of greatest packing density and thrombin activity, and appears prior to full platelet activation. Deleting the contact-dependent signaling molecule, Sema4D, delays platelet activation, but not the emergence of the low transport region. Collectively, these results suggest a timeline in which initial platelet accumulation and the narrowing gaps between platelets create a region of reduced transport that facilitates local thrombin accumulation and greater platelet activation, whereas faster transport rates within the shell help to limit thrombin accumulation and growth of the core. Thus, from a systems perspective, platelet accumulation produces an altered microenvironment that shapes thrombus architecture, which in turn affects agonist distribution and subsequent thrombus growth. PMID:24951424

  20. Morphology, structural properties and reducibility of size-selected CeO2− x nanoparticle films

    PubMed Central

    D’Addato, Sergio; Gasperi, Gabriele; Benedetti, Francesco; Luches, Paola; Grillo, Vincenzo; Bertoni, Giovanni; Valeri, Sergio

    2015-01-01

    Summary Non-stoichiometric ceria nanoparticles (NPs) were obtained by a gas aggregation source with a magnetron and were mass-selected with a quadrupole mass filter. By varying magnetron power, Ar gas flow, and the length of the aggregation tube, NPs with an average diameter of 6, 9, and 14 nm were synthesized and deposited onto a substrate, thus obtaining NP films. The morphology of the films was studied with scanning electron microscopy, while high resolution transmission electron microscopy was used to gain a deeper insight into the atomic structure of individual NPs. By using X-ray photoelectron spectroscopy we analyzed the degree of reduction of the NPs of different diameters, before and after thermal treatments in vacuum (reduction cycle) and in O2 atmosphere (oxidation cycle) at different temperatures. From this analysis we inferred that the size is an important parameter only at intermediate temperatures. As a comparison, we evaluated the reducibility of an ultra-thin ceria film with the same surface to volume ratio as the 9 nm diameter NPs film, observing that NPs are more reducible than the ceria film. PMID:25671152

  1. Impact of poroelasticity of intraluminal thrombus on wall stress of abdominal aortic aneurysms

    PubMed Central

    2012-01-01

    Background The predictions of stress fields in Abdominal Aortic Aneurysm (AAA) depend on constitutive descriptions of the aneurysm wall and the Intra-luminal Thrombus (ILT). ILT is a porous diluted structure (biphasic solid–fluid material) and its impact on AAA biomechanics is controversially discussed in the literature. Specifically, pressure measurements showed that the ILT cannot protect the wall from the arterial pressure, while other (numerical and experimental) studies showed that at the same time it reduces the stress in the wall. Method To explore this phenomenon further a poroelastic description of the ILT was integrated in Finite Element (FE) Models of the AAA. The AAA model was loaded by a pressure step and a cyclic pressure wave and their transition into wall tension was investigated. To this end ILT’s permeability was varied within a microstructurally motivated range. Results The two-phase model verified that the ILT transmits the entire mean arterial pressure to the wall while, at the same time, it significantly reduces the stress in the wall. The predicted mean stress in the AAA wall was insensitive to the permeability of the ILT and coincided with the results of AAA models using a single-phase ILT description. Conclusion At steady state, the biphasic ILT behaves like a single-phase material in an AAA model. Consequently, computational efficient FE single-phase models, as they have been exclusively used in the past, accurately predict the wall stress in AAA models. PMID:22931215

  2. A natural antipredation experiment: predator control and reduced sea ice increases colony size in a long-lived duck

    PubMed Central

    Hanssen, Sveinn A; Moe, Børge; Bårdsen, Bård-Jørgen; Hanssen, Frank; Gabrielsen, Geir W

    2013-01-01

    Anthropogenic impact on the environment and wildlife are multifaceted and far-reaching. On a smaller scale, controlling for predators has been increasing the yield from local natural prey resources. Globally, human-induced global warming is expected to impose severe negative effects on ecosystems, an effect that is expected to be even more pronounced in the scarcely populated northern latitudes. The clearest indication of a changing Arctic climate is an increase in both air and ocean temperatures leading to reduced sea ice distribution. Population viability is for long-lived species dependent on adult survival and recruitment. Predation is the main mortality cause in many bird populations, and egg predation is considered the main cause of reproductive failure in many birds. To assess the effect of predation and climate, we compared population time series from a natural experiment where a trapper/down collector has been licensed to actively protect breeding common eiders Somateria mollissima (a large seaduck) by shooting/chasing egg predators, with time series from another eider colony located within a nature reserve with no manipulation of egg predators. We found that actively limiting predator activity led to an increase in the population growth rate and carrying capacity with a factor of 3–4 compared to that found in the control population. We also found that population numbers were higher in years with reduced concentration of spring sea ice. We conclude that there was a large positive impact of human limitation of egg predators, and that this lead to higher population growth rate and a large increase in size of the breeding colony. We also report a positive effect of warming climate in the high arctic as reduced sea-ice concentrations was associated with higher numbers of breeding birds. PMID:24223290

  3. Mesoscopic Modeling of Thrombus Formation and Growth: Platelet Deposition in Complex Geometries

    NASA Astrophysics Data System (ADS)

    Yazdani, Alireza; Karniadakis, George

    2014-11-01

    Haemodynamics and blood rheology are important contributing factors to thrombus formation at a vulnerable vessel wall, and adhesion of platelets to a vascular surface, particularly in regions of flow stagnation, recirculation and reattachment is significantly important in formation of thrombi. For example, haemodynamic micro-environment can have effects on thrombosis inside the atherosclerotic plaques and aneurysms. To study these effects, we have developed and validated a model for platelet aggregation in blood flow using Dissipative Particle Dynamics (DPD) method. In this model platelets are considered as single DPD particles interacting with each other via Morse potential once activated. We assign an activation delay time to each platelet such that they remain passive during that time. We investigate the effect of different geometries on platelet aggregation by considering arterial stenosis at different levels of occlusion, and aneurysms of different shapes and sizes. The results show a marked increase in platelet aggregation within the boundaries of deceleration zone by increasing the degree of stenosis. Further, we observe enhanced platelet margination and wall deposition in the presence of red blood cells.

  4. Left atrial thrombus formation after brief interruption of rivaroxaban.

    PubMed

    Turner, Matthew; Solarz, David

    2016-01-01

    Every year, nearly 250000 atrial fibrillation patients require temporary interruption of anticoagulation therapy for invasive procedures, acute illness, or bleeding events. Rivaroxaban is an oral anticoagulant that works by inhibiting factor Xa leading to a blockage of thrombin production, which inhibits platelet aggregation and thrombus formation. As with other anticoagulants, there is an increased risk of a thrombotic event occurring when rivaroxaban therapy is temporarily interrupted (TI) or prematurely discontinued. The 30-day rate of stroke or systemic embolism for rivaroxaban TI is 0.36%. Possible factors for higher than expected rates of embolic events include a prothrombotic perioperative environment among patients having TI for surgery and a prothrombotic environment associated with TI due to bleeding. The ROCKET AF study showed that there was no detectable difference in the risk of stroke and systemic embolism for participants treated with rivaroxaban vs warfarin undergoing TI. Another analysis suggested that the risk for stroke from TI is probably higher in the rivaroxaban group with 3 to 30 days discontinuation. Alternative anticoagulation therapy such as bridging should always be considered when stopping rivaroxaban. PMID:26081413

  5. Chlorogenic Acid Inhibits Human Platelet Activation and Thrombus Formation

    PubMed Central

    Fuentes, Eduardo; Caballero, Julio; Alarcón, Marcelo; Rojas, Armando; Palomo, Iván

    2014-01-01

    Background Chlorogenic acid is a potent phenolic antioxidant. However, its effect on platelet aggregation, a critical factor in arterial thrombosis, remains unclear. Consequently, chlorogenic acid-action mechanisms in preventing platelet activation and thrombus formation were examined. Methods and Results Chlorogenic acid in a dose-dependent manner (0.1 to 1 mmol/L) inhibited platelet secretion and aggregation induced by ADP, collagen, arachidonic acid and TRAP-6, and diminished platelet firm adhesion/aggregation and platelet-leukocyte interactions under flow conditions. At these concentrations chlorogenic acid significantly decreased platelet inflammatory mediators (sP-selectin, sCD40L, CCL5 and IL-1β) and increased intraplatelet cAMP levels/PKA activation. Interestingly, SQ22536 (an adenylate cyclase inhibitor) and ZM241385 (a potent A2A receptor antagonist) attenuated the antiplatelet effect of chlorogenic acid. Chlorogenic acid is compatible to the active site of the adenosine A2A receptor as revealed through molecular modeling. In addition, chlorogenic acid had a significantly lower effect on mouse bleeding time when compared to the same dose of aspirin. Conclusions Antiplatelet and antithrombotic effects of chlorogenic acid are associated with the A2A receptor/adenylate cyclase/cAMP/PKA signaling pathway. PMID:24598787

  6. Disrupting the EMMPRIN-Cyclophilin A interaction reduces infarct size and preserves systolic function after myocardial ischemia and reperfusion

    PubMed Central

    Seizer, Peter; Ochmann, Carmen; Schönberger, Tanja; Zach, Sebastian; Rose, Melanie; Borst, Oliver; Klingel, Karin; Kandolf, Reinhard; MacDonald, H. Robson; Nowak, Romana A.; Engelhardt, Stefan; Lang, Florian; Gawaz, Meinrad; May, Andreas E.

    2011-01-01

    Introduction Inflammation and proteolysis crucially contribute to myocardial ischemia and reperfusion injury. The Extracellular Matrix Metalloproteinase Inducer (EMMPRIN, CD147) and its ligand Cyclophilin A (CyPA) may be involved in both processes. The aim of the study was to characterize the role of the CD147 and CyPA interplay in myocardial ischemia/reperfusion (I/R) injury. Methods and results Immunohistochemistry showed enhanced expression of CD147 and CyPA in myocardial sections from human autopsies of patients who had died from acute myocardial infarction and from mice at 24 hours after I/R. At 24 hours and 7 days after I/R, the infarct size was reduced in CD147+/− mice versus CD147+/+ mice (C57Bl/6), in mice (C57Bl/6) treated with mAb anti-CD147 vs. control mAb, and in CyPA−/− mice vs. CyPA+/+ mice (129S6/SvEv), all of which being associated with reduced monocyte and neutrophil recruitment at 24h and with a preserved systolic function at 7 days. Combination of CyPA−/− mice with anti-CD147 treatment did not yield further protection in comparison to either inhibition strategy alone. In vitro, treatment with CyPA induced monocyte chemotaxis in a CD147- and PI3-kinase dependent manner and induced monocyte rolling and adhesion to endothelium (HUVEC) under flow in a CD147-dependent manner. Conclusion CD147 and its ligand CyPA are inflammatory mediators after myocardial ischemia and reperfusion and represent potential targets to prevent myocardial I/R injury. PMID:21441138

  7. Innate immune response after acute myocardial infarction and pharmacomodulatory action of tacrolimus in reducing infarct size and preserving myocardial integrity

    PubMed Central

    2013-01-01

    Background This study investigated the association between innate immune reaction and myocardial damage after acute myocardial infarction (AMI) and anti-inflammatory role of tacrolimus in reducing infarct size. Male mini-pigs (n=18) were equally categorized into sham control (SC), untreated AMI (by ligation of left anterior descending coronary artery), and AMI-Tacrolimus (AMI-Tac) (0.5 mg intra-coronary injection 30 minutes post-AMI). Cardiac magnetic resonance imaging (MRI) was performed at post-AMI days 2, 5 and 21 before sacrificing the animals. Results By post-AMI day 21, left ventricular ejection fraction (LVEF) was lowest in untreated AMI animals, significantly higher in SC than in AMI-Tac group (all p<0.003). Infarct areas at basal, middle, and apical levels, numbers of CD14+ and iNOS+ cells in infarct area (IA) and peri-IA, and protein expression of CD14, CD68, and Ly6g from circulating inflammatory cells showed an opposite pattern compared with that of LVEF in all groups (all p<0.005). Protein expressions of MCP-1, MIP-1, TNF-α, NF-κB, iNOS, and IL-12 in IA and peri-IA exhibited an identical pattern compared to that of CD14, CD68, and Ly6g from circulating inflammatory cells (all p<0.01). Expressions of myocardial damage biomarkers in IA and peri-IA [γ-H2AX, β-myosin heavy chain (MHC), Smad3, TGF-β] were highest in AMI and higher in AMI-Tac than in SC, whereas expressions of myocardial integrity biomarkers (connexin43, mitochondrial cytochrome-C, α-MHC, BMP-2, Smad1/5) were opposite to those of damage biomarkers (all p<0.001). Conclusion Innate immune responses were markedly augmented and LVEF was significantly reduced after AMI but were remarkably improved after tacrolimus treatment. PMID:24165293

  8. Extensive tumor thrombus in a case of carcinoma lung detected by F18-FDG-PET/CT.

    PubMed

    Mudalsha, Ravina; Jacob, Mj; Pandit, Ag; Jora, Charu

    2011-04-01

    Tumor thrombus is a rare complication of solid cancers, mainly seen in cases of renal cell carcinoma, wilm's tumor, testicular carcinoma, adrenal cortical carcinoma and hepatocellular carcinoma.[1] Tumor thrombus in inferior vena cava is a rare complication of primary carcinoma lung. It should be identified so as to rule out venous thromboembolism and avoiding unnecessary anticoagulant therapy. We describe a case where F18-Fluorodeoxyglucose (FDG) positron emission tomography - computed tomography (PET/CT) helped to identify extensive tumor thrombus. PMID:22174524

  9. Extensive tumor thrombus in a case of carcinoma lung detected by F18-FDG-PET/CT

    PubMed Central

    Mudalsha, Ravina; Jacob, MJ; Pandit, AG; Jora, Charu

    2011-01-01

    Tumor thrombus is a rare complication of solid cancers, mainly seen in cases of renal cell carcinoma, wilm's tumor, testicular carcinoma, adrenal cortical carcinoma and hepatocellular carcinoma.[1] Tumor thrombus in inferior vena cava is a rare complication of primary carcinoma lung. It should be identified so as to rule out venous thromboembolism and avoiding unnecessary anticoagulant therapy. We describe a case where F18-Fluorodeoxyglucose (FDG) positron emission tomography - computed tomography (PET/CT) helped to identify extensive tumor thrombus. PMID:22174524

  10. An Examination of Teachers' Perceptions and Practice when Teaching Large and Reduced-Size Classes: Do Teachers Really Teach Them in the Same Way?

    ERIC Educational Resources Information Center

    Harfitt, Gary James

    2012-01-01

    Class size research suggests that teachers do not vary their teaching strategies when moving from large to smaller classes. This study draws on interviews and classroom observations of three experienced English language teachers working with large and reduced-size classes in Hong Kong secondary schools. Findings from the study point to subtle…

  11. Flow residence time and regions of intraluminal thrombus deposition in intracranial aneurysms.

    PubMed

    Rayz, V L; Boussel, L; Ge, L; Leach, J R; Martin, A J; Lawton, M T; McCulloch, C; Saloner, D

    2010-10-01

    Thrombus formation in intracranial aneurysms, while sometimes stabilizing lesion growth, can present additional risk of thrombo-embolism. The role of hemodynamics in the progression of aneurysmal disease can be elucidated by patient-specific computational modeling. In our previous work, patient-specific computational fluid dynamics (CFD) models were constructed from MRI data for three patients who had fusiform basilar aneurysms that were thrombus-free and then proceeded to develop intraluminal thrombus. In this study, we investigated the effect of increased flow residence time (RT) by modeling passive scalar advection in the same aneurysmal geometries. Non-Newtonian pulsatile flow simulations were carried out in base-line geometries and a new postprocessing technique, referred to as "virtual ink" and based on the passive scalar distribution maps, was used to visualize the flow and estimate the flow RT. The virtual ink technique clearly depicted regions of flow separation. The flow RT at different locations adjacent to aneurysmal walls was calculated as the time the virtual ink scalar remained above a threshold value. The RT values obtained in different areas were then correlated with the location of intra-aneurysmal thrombus observed at a follow-up MR study. For each patient, the wall shear stress (WSS) distribution was also obtained from CFD simulations and correlated with thrombus location. The correlation analysis determined a significant relationship between regions where CFD predicted either an increased RT or low WSS and the regions where thrombus deposition was observed to occur in vivo. A model including both low WSS and increased RT predicted thrombus-prone regions significantly better than the models with RT or WSS alone. PMID:20499185

  12. A Self-Organizing Map-Based Approach to Generating Reduced-Size, Statistically Similar Climate Datasets

    NASA Astrophysics Data System (ADS)

    Cabell, R.; Delle Monache, L.; Alessandrini, S.; Rodriguez, L.

    2015-12-01

    Climate-based studies require large amounts of data in order to produce accurate and reliable results. Many of these studies have used 30-plus year data sets in order to produce stable and high-quality results, and as a result, many such data sets are available, generally in the form of global reanalyses. While the analysis of these data lead to high-fidelity results, its processing can be very computationally expensive. This computational burden prevents the utilization of these data sets for certain applications, e.g., when rapid response is needed in crisis management and disaster planning scenarios resulting from release of toxic material in the atmosphere. We have developed a methodology to reduce large climate datasets to more manageable sizes while retaining statistically similar results when used to produce ensembles of possible outcomes. We do this by employing a Self-Organizing Map (SOM) algorithm to analyze general patterns of meteorological fields over a regional domain of interest to produce a small set of "typical days" with which to generate the model ensemble. The SOM algorithm takes as input a set of vectors and generates a 2D map of representative vectors deemed most similar to the input set and to each other. Input predictors are selected that are correlated with the model output, which in our case is an Atmospheric Transport and Dispersion (T&D) model that is highly dependent on surface winds and boundary layer depth. To choose a subset of "typical days," each input day is assigned to its closest SOM map node vector and then ranked by distance. Each node vector is treated as a distribution and days are sampled from them by percentile. Using a 30-node SOM, with sampling every 20th percentile, we have been able to reduce 30 years of the Climate Forecast System Reanalysis (CFSR) data for the month of October to 150 "typical days." To estimate the skill of this approach, the "Measure of Effectiveness" (MOE) metric is used to compare area and overlap

  13. Thrombus Formation After Percutaneous Catheterization and Manual Compression of the Femoral Artery in Heparinized Sheep

    SciTech Connect

    Kim, Young Hwan; Pavcnik, Dusan Kakizawa, Hideyaki; Uchida, Barry T.; Burke, Allen; Loriaux, Marc; Keller, Frederick S.; Rosch, Josef

    2010-04-15

    The purpose of this study was to evaluate the angiographic and histopathologic changes in the superficial femoral artery (SFA) in heparinized sheep shortly after catheterization with an 8-Fr sheath and manual compression hemostasis either with standard manual compression (SMC) or with the use of a procoagulant chitosan-based HemCon Bandage. The evaluation was done in 38 SFAs of 19 heparinized (100 mg/kg) sheep. After a 5-min catheterization with an 8-Fr sheath, a 5-min compression was applied. Follow-up angiograms to evaluate hemostasis were done immediately after release of compression and then at 2.5-min intervals until no extravasation was present. Compression was reapplied between angiograms. Final angiograms were performed approximately 30 min after hemostasis and after 3 min of passive flexion and extension of sheep hind limbs. Sheep were then euthanized and SFA specimens with surrounding tissues excised for histopathologic evaluation. Both types of compression caused similar changes in the catheterized SFAs. Follow-up angiograms showed mild arterial narrowing in 14 SFAs and intraluminal clots in 9 SFAs. Histology revealed periarterial hematoma in all 38 specimens. Intraluminal thrombi consisting predominantly of platelets and fibrin were present in 32 SFAs. Their size varied from superficial elevations (8 arteries) to medium-sized, 1- to 2-mm, polypoid protrusions (15 arteries) to large polypoid clots, 3-4 mm long (9 arteries). In six SFAs, the arterial access sites were not included in the obtained specimens. In conclusion, hemostasis with manual compression is achieved in the acute phase by formation of a predominantly platelet-fibrin thrombus occluding the arterial wall access site and often extending significantly into the arterial lumen. The healing process of arterial access sites should be explored several days after catheterization.

  14. A thrombus susceptibility comparison of two pulsatile Penn State 50 cc left ventricular assist device designs.

    PubMed

    Navitsky, Michael A; Deutsch, Steven; Manning, Keefe B

    2013-01-01

    Left ventricular assist devices (LVADs) have proven successful as bridge to transplant devices for patients awaiting donor organs. While survival rates continue to increase, destination therapy remains hindered by thrombus formation within the device. Research has shown that thrombosis is correlated to the fluid dynamics within the device and may be a result of sustained shear rates below 500 s(-1) on the polyurethane blood sac used in the Penn State pulsatile LVAD. Particle image velocimetry is used to compare flow within two 50 cc LVAD designs to assess fluid patterns and quantify wall shear rates in regions known from in vivo studies to be susceptible to thrombus formation. The two designs differ in their front face geometry. The V-1 model has an outward-facing "dome" whereas the face of the V-2 model is flat. A thrombus susceptibility metric, which uses measured wall shear rates and exposure times, was applied to objectively compare pump designs over the entire cardiac cycle. For each design, there are regions where wall shear rates remained below 500 s(-1) for the entire cardiac cycle resulting in high thrombus susceptibility potential. Results of this study indicate that the V-2 device had an overall lower propensity for thrombus formation in the current region of interest. PMID:22825798

  15. Segmentation of the thrombus of giant intracranial aneurysms from CT angiography scans with lattice Boltzmann method.

    PubMed

    Chen, Yu; Navarro, Laurent; Wang, Yan; Courbebaisse, Guy

    2014-01-01

    Computed Tomography Angiography (CTA) plays an essential role in the diagnosis, treatment evaluation, and monitoring of cerebral aneurysms. Segmentation of CTA medical images of giant intracranial aneurysms (GIA) provides quantitative measurements of thrombus and aneurysms geometrical characteristics allowing 3D reconstruction. In fact, GIA demonstrated neuroradiological features and propensity of partial or total spontaneous intra-aneurysmal thrombosis generating a thrombus. Despite intensive researches on medical image segmentation, aneurysm (Lumen, Thrombus, and Parent Blood Vessels) segmentation remains as a difficult problem that has not been yet resolved. In this paper, we proposed a Lattice Boltzmann Geodesic Active Contour Method (LBGM) for aneurysm segmentation in CTA images in order to estimate both the volumes of the thrombus and the aneurysm. Although the noise in the CTA images is very strong and the edges of the thrombus are not so different than the surrounding tissues, the aneurysms are segmented effectively. Based on these results, a method using a dome-neck aspect ratio (AR) parameter for the evaluation of the Spontaneous Thrombosis (ST) phenomena demonstrates the promising potentiality of this LBGM for clinical applications. PMID:24077409

  16. Identification of platelet function defects by multi-parameter assessment of thrombus formation

    PubMed Central

    de Witt, Susanne M.; Swieringa, Frauke; Cavill, Rachel; Lamers, Moniek M. E.; van Kruchten, Roger; Mastenbroek, Tom; Baaten, Constance; Coort, Susan; Pugh, Nicholas; Schulz, Ansgar; Scharrer, Inge; Jurk, Kerstin; Zieger, Barbara; Clemetson, Kenneth J.; Farndale, Richard W.; Heemskerk, Johan W. M.; Cosemans, Judith M.E.M.

    2014-01-01

    Assays measuring platelet aggregation (thrombus formation) at arterial shear rate mostly use collagen as only platelet-adhesive surface. Here we report a multi-surface and multi-parameter flow assay to characterize thrombus formation in whole blood from healthy subjects and patients with platelet function deficiencies. A systematic comparison is made of 52 adhesive surfaces with components activating the main platelet-adhesive receptors, and of eight output parameters reflecting distinct stages of thrombus formation. Three types of thrombus formation can be identified with a predicted hierarchy of the following receptors: glycoprotein (GP)VI, C-type lectin-like receptor-2 (CLEC-2)>GPIb>α6β1, αIIbβ3>α2β1>CD36, α5β1, αvβ3. Application with patient blood reveals distinct abnormalities in thrombus formation in patients with severe combined immune deficiency, Glanzmann’s thrombasthenia, Hermansky–Pudlak syndrome, May–Hegglin anomaly or grey platelet syndrome. We suggest this test may be useful for the diagnosis of patients with suspected bleeding disorders or a pro-thrombotic tendency. PMID:25027852

  17. A Thrombus Susceptibility Comparison of Two Pulsatile Penn State 50cc Left Ventricular Assist Device Designs

    PubMed Central

    Navitsky, Michael A.; Deutsch, Steven; Manning, Keefe B.

    2012-01-01

    Left ventricular assist devices (LVADs) have proven successful as bridge to transplant devices for patients awaiting donor organs. While survival rates continue to increase, destination therapy remains hindered by thrombus formation within the device. Research has shown that thrombosis is correlated to the fluid dynamics within the device and may be a result of sustained shear rates below 500 s−1 on the polyurethane blood sac used in the Penn State pulsatile LVAD. Particle image velocimetry is used to compare flow within two 50 cc LVAD designs to assess fluid patterns and quantify wall shear rates in regions known from in vivo studies to be susceptible to thrombus formation. The two designs differ in their front face geometry. The V-1 model has an outward facing “dome” whereas the face of the V-2 model is flat. A thrombus susceptibility metric, which uses measured wall shear rates and exposure times, was applied to objectively compare pump designs over the entire cardiac cycle. For each design, there are regions where wall shear rates remained below 500 s−1 for the entire cardiac cycle resulting in high thrombus susceptibility potential. Results of this study indicate that the V-2 device had an overall lower propensity for thrombus formation in the current region of interest. PMID:22825798

  18. Registration, segmentation, and visualization of confocal microscopy images of arterial thrombus

    NASA Astrophysics Data System (ADS)

    Garg, Ishita; Camp, Jon J.; McBane, Robert; Wysokinski, Waldemar; Robb, Richard A.

    2004-05-01

    Arterial thrombosis causes death or paralysis of an organ, as it migrates to and localizes in different parts of the body. Massive pulmonary emboli cause 50,000 deaths per year. The cause and origin of arterial thrombosis is not well understood nor objectively characterized. The object of this study was to investigate the microscopic structure of arterial thrombus to better understand this pathology. Confocal microscopy cross-sectional images of an embolized thrombus in the coronary artery were obtained. Adjacent pairs of sections were stained with two different stains, fibrin and CD61, to reveal mutually complementary information. The very thin adjacent slices were treated as one slice. Adjacent slices were registered by a combination of manual and automatic techniques using Analyze software developed in the Biomedical Imaging Resource at Mayo. After smoothing the images with a median filter, the CD61 and fibrin stained section images were used together to segment the tissues by multispectral classification. The image volume was classified into background, platelets and surrounding tissue, and thrombus. The segmented volume was then rendered for visualization and analysis of structure of the thrombus in three dimensions. Preliminary results are promising. Such correlation of structural and histological information may be helpful in determining the origin of the thrombus.

  19. How Well Does Fracture Set Characterization Reduce Uncertainty in Capture Zone Size for Wells Situated in Sedimentary Bedrock Aquifers?

    NASA Astrophysics Data System (ADS)

    West, A. C.; Novakowski, K. S.

    2005-12-01

    Regional groundwater flow models are rife with uncertainty. The three-dimensional flux vector fields must generally be inferred using inverse modelling from sparse measurements of hydraulic head, from measurements of hydraulic parameters at a scale that is miniscule in comparison to that of the domain, and from none to a very few measurements of recharge or discharge rate. Despite the inherent uncertainty in these models they are routinely used to delineate steady-state or time-of-travel capture zones for the purpose of wellhead protection. The latter are defined as the volume of the aquifer within which released particles will arrive at the well within the specified time and their delineation requires the additional step of dividing the magnitudes of the flux vectors by the assumed porosity to arrive at the ``average linear groundwater velocity'' vector field. Since the porosity is usually assumed constant over the domain one could be forgiven for thinking that the uncertainty introduced at this step is minor in comparison to the flow model calibration step. We consider this question when the porosity in question is fracture porosity in flat-lying sedimentary bedrock. We also consider whether or not the diffusive uptake of solute into the rock matrix which lies between the source and the production well reduces or enhances the uncertainty. To evaluate the uncertainty an aquifer cross section is conceptualized as an array of horizontal, randomly-spaced, parallel-plate fractures of random aperture, with adjacent horizontal fractures connected by vertical fractures again of random spacing and aperture. The source is assumed to be a continuous concentration (i.e. a dirichlet boundary condition) representing a leaking tank or a DNAPL pool, and the receptor is a fully pentrating well located in the down-gradient direction. In this context the time-of-travel capture zone is defined as the separation distance required such that the source does not contaminate the well

  20. Intrameal Hepatic Portal and Intraperitoneal Infusions of Glucagon-Like Peptide-1 Reduce Spontaneous Meal Size in the Rat via Different Mechanisms

    PubMed Central

    Rüttimann, Elisabeth B.; Arnold, Myrtha; Hillebrand, Jacquelien J.; Geary, Nori; Langhans, Wolfgang

    2009-01-01

    Peripheral administration of glucagon-like peptide (GLP)-1 reduces food intake in animals and humans, but the sites and mechanism of this effect and its physiological significance are not yet clear. To investigate these issues, we prepared rats with chronic catheters and infused GLP-1 (0.2 ml/min; 2.5 or 5.0 min) during the first spontaneous dark-phase meals. Infusions were remotely triggered 2–3 min after meal onset. Hepatic portal vein (HPV) infusion of 1.0 or 3.0 (but not 0.33) nmol/kg GLP-1 reduced the size of the ongoing meal compared with vehicle without affecting the subsequent intermeal interval, the size of subsequent meals, or cumulative food intake. In double-cannulated rats, HPV and vena cava infusions of 1.0 nmol/kg GLP-1 reduced meal size similarly. HPV GLP-1 infusions of 1.0 nmol/kg GLP-1 also reduced meal size similarly in rats with subdiaphragmatic vagal deafferentations and in sham-operated rats. Finally, HPV and ip infusions of 10 nmol/kg GLP-1 reduced meal size similarly in sham-operated rats, but only HPV GLP-1 reduced meal size in subdiaphragmatic vagal deafferentation rats. These data indicate that peripherally infused GLP-1 acutely and specifically reduces the size of ongoing meals in rats and that the satiating effect of ip, but not iv, GLP-1 requires vagal afferent signaling. The findings suggest that iv GLP-1 infusions do not inhibit eating via hepatic portal or hepatic GLP-1 receptors but may act directly on the brain. PMID:18948395

  1. Allocating Sample Sizes to Reduce Budget for Fixed-Effect 2×2 Heterogeneous Analysis of Variance

    ERIC Educational Resources Information Center

    Luh, Wei-Ming; Guo, Jiin-Huarng

    2016-01-01

    This article discusses the sample size requirements for the interaction, row, and column effects, respectively, by forming a linear contrast for a 2×2 factorial design for fixed-effects heterogeneous analysis of variance. The proposed method uses the Welch t test and its corresponding degrees of freedom to calculate the final sample size in a…

  2. Platelets and coagulation in thrombus formation: aberrations in the Scott syndrome.

    PubMed

    van Geffen, Johanna P; Swieringa, Frauke; Heemskerk, Johan W M

    2016-05-01

    Platelets play key roles in thrombosis and hemostasis by forming aggregates and providing a procoagulant surface, at which thrombin is generated and fibrin fibers are formed. Here we present an overview of the different mechanisms how platelets orchestrate coagulation processes in thrombus formation in thrombosis and hemostasis. Parts of these are via Ca(2+)-dependent activation responses, leading to phosphatidylserine exposure; swelling to form balloons with increased binding of coagulation factors; and calpain-mediated integrin αIIbβ3 cleavage and inactivation. Other mechanisms are secretion of (anti) coagulation factors, and αIIbβ3-mediated thrombus retraction, and clot retraction. In a thrombus, coagulation factors are found at both platelets and fibrin fibers. Many of the procoagulant platelet activities are altered in the Scott syndrome. PMID:27207414

  3. Synthetic thrombus model for in-vitro studies of laser thrombolysis

    NASA Astrophysics Data System (ADS)

    Hermes, Robert E.; Trajkovska, Keti

    1998-05-01

    Laser thrombolysis is the controlled ablation of a thrombus (blood clot) blockage in a living arterial system. Theoretical modeling of the interaction of laser light with thrombi relies on the ability to perform in vitro experiments with well characterized surrogate materials. A synthetic thrombus formulation may offer more accurate results when compared to in vivo clinical experiments. We describe here the development of new surrogate materials based on formulations incorporating chicken egg, guar gum, modified food starch, and a laser light absorbing dye. The sound speed and physical consistency of the materials were very close to porcine (arterial) and human (venous) thrombi. Photographic and videotape recordings of pulsed dye laser ablation experiments under various experimental conditions were used to evaluate the new material as compared to in vitro tests with human (venous) thrombus. The characteristics of ablation and mass removal were similar to that of real thrombi, and therefore provide a more realistic model for in vitro laser thrombolysis when compared to gelatin.

  4. Feasibility of the optical imaging of thrombus formation in a rotary blood pump by near-infrared light.

    PubMed

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu

    2014-09-01

    Blood coagulation is one of the primary concerns when using mechanical circulatory support devices such as blood pumps. Noninvasive detection and imaging of thrombus formation is useful not only for the development of more hemocompatible devices but also for the management of blood coagulation to avoid risk of infarction. The objective of this study is to investigate the use of near-infrared light for imaging of thrombus formation in a rotary blood pump. The optical properties of a thrombus at wavelengths ranging from 600 to 750 nm were analyzed using a hyperspectral imaging (HSI) system. A specially designed hydrodynamically levitated centrifugal blood pump with a visible bottom area was used. In vitro antithrombogenic testing was conducted five times with the pump using bovine whole blood in which the activated blood clotting time was adjusted to 200 s prior to the experiment. Two halogen lights were used for the light sources. The forward scattering through the pump and backward scattering on the pump bottom area were imaged using the HSI system. HSI showed an increase in forward scattering at wavelengths ranging from 670 to 750 nm in the location of thrombus formation. The time at which the thrombus began to form in the impeller rotating at 2780 rpm could be detected. The spectral difference between the whole blood and the thrombus was utilized to image thrombus formation. The results indicate the feasibility of dynamically detecting and imaging thrombus formation in a rotary blood pump. PMID:25234757

  5. Multimodality Treatment for Hepatocellular Carcinoma With Portal Vein Tumor Thrombus

    PubMed Central

    Wang, Kang; Guo, Wei Xing; Chen, Min Shan; Mao, Yi Lei; Sun, Bei Cheng; Shi, Jie; Zhang, Yao Jun; Meng, Yan; Yang, Ye Fa; Cong, Wen Ming; Wu, Meng Chao; Lau, Wan Yee; Cheng, Shu Qun

    2016-01-01

    Abstract The optimal treatment for hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) remains controversial. We aimed to investigate the best treatment for patients with HCC with PVTT. From January 2002 to January 2014, the data from all consecutive patients with HCC with PVTT who underwent surgical treatment (ST),TACE,TACE combined with sorafenib (TACE-Sor), or TACE combined with radiotherapy (TACE-RT) in the 4 largest tertiary hospitals in China were analyzed retrospectively. The patients were divided into 3 subtypes according to the extent of PVTT in the portal vein (type I-III). The primary endpoint was overall survival (OS). A total of 1580 patients with HCC with PVTT were included in the study. The median survival times (MST) for ST (n = 745) for type I, II, and III patients (95% CI) were 15.9 (13.3–18.5), 12.5 (10.7–14.3), and 6.0 (4.3–7.7) months, respectively. The corresponding figures for patients after TACE (n = 604) were 9.3 (5.6–12.9), 4.9 (4.1–5.7), and 4.0 (3.1–4.9), respectively; for patients after TACE-Sor (n = 113) 12.0 (6.6–17.4), 8.9 (6.7–11.1), and 7.0 (3.0–10.9), respectively; and for patients after TACE-RT (n = 118) 12.2 (0–24.7), 10.6 (6.8–14.5), and 8.9 (5.2–12.6), respectively. Comparison among the different treatments for the 3 subtypes of PVTT patients after propensity score (PS) matching showed the effectiveness of ST to be the best for type I and type II PVTT patients, and TACE-RT was most beneficial for type III patients. Treatment was an independent risk factor of OS. ST was the best treatment for type I and II PVTT patients with Child-Pugh A and selected B liver function. TACE-RT should be given to type III PVTT patients. PMID:26986115

  6. Acute Bilateral Internal Carotid Occlusion from Embolization of Left Atrial Thrombus During Transesophageal Echocardiography: Case Report

    PubMed Central

    Mahmood, Syed Saad; Manjila, Sunil; Singh, Gagandeep; Xavier, Andrew R

    2016-01-01

    Background and purpose: Transesophageal echocardiography (TEE) is a relatively safe imaging modality used to visualize intracardiac thrombus. Summary of case: We report on a unique, fatal complication during TEE of embolization of a pre-existing “smoking” left atrial thrombus causing acute bilateral internal carotid occlusion, confirmed on angiogram. Conclusions: Patients with history of lung pathology, such as COPD, who experience retching and cough during transesophageal echocardiography may be more susceptible to embolization of pre-existing thrombi. A need exists to risk stratify such patients. PMID:27403219

  7. Thrombus on Indwelling Central Venous Catheters: The Histopathology of 'Fibrin Sheaths'

    SciTech Connect

    Suojanen, James Norman; Brophy, David Paul; Nasser, Imad

    2000-03-15

    Purpose: Central venous catheters (CVC) may fail for many reasons, though 'fibrin sheaths' blocking catheter ports are usually implicated. We examined the sheaths removed from dialysis catheters to determine their histopathology.Methods: Ten catheter strippings were performed and the removed material was studied grossly and microscopically.Results: The histologic specimens showed thrombus both with and without a proteinaceous sheath.Conclusion: Dialysis catheters fail because of thrombus formation. This can occur in either the absence or presence of a protein coating on the catheter, the so-called 'fibrin sheath.'.

  8. The prevention of circulatory collapse in left atrial myxoma or left atrail thrombus patients.

    PubMed

    Sun, Jie; Ding, Zhengnian

    2016-05-01

    Some patients with myxoma or thrombus may develop to severe hypotension or sudden death. In this article, we hypothesize a clinical scenario that when the myxoma or thrombus blocks in the mitral valve and causes significant hypotension during anesthesia or surgery. Increasing cardiac preload will be an effective preventive method to increasing the mitral valve annulus and decreasing the severity of stenosis, as a result it will prevent circulatory collapse. Our hypothesis will decrease the possibility of lethal mitral valve stenosis induced by left atrial mass blocking the mitral valve area. In addition, we should also maintain a relative slow heart rate and a relative high systemic vascular resistance. PMID:27063074

  9. Novel use of the AngioVac® system to remove thrombus during simultaneous extracorporeal membrane oxygenation life support.

    PubMed

    Griffith, Kevin E; Jenkins, Eric; Copenhaver, William; Williams, David M

    2016-03-01

    Extracorporeal membrane oxygenation (ECMO) was introduced to clinical medicine over 40 years ago. While initially used as a treatment for acute respiratory failure in infants, the use of ECMO has grown to include respiratory and circulatory failure in both children and adults, cardiogenic shock, pulmonary embolism, sepsis, trauma, malignancy, pulmonary hemorrhage and as a treatment for hypothermic drowning.(1) Recent technological improvements in ECMO circuitry make it possible to minimize anticoagulation of the ECMO patient, decreasing the incidence of bleeding. Thrombus deposition within the ECMO circuit can be a life-threating complication. ECMO circuit thrombus can be contained in the circuit, adherent to cannula and deposited within the patient. The ability to remove thrombus while the patient remains on ECMO support could be a life-saving measure for some patients. The present case report outlines use of the AngioVac(®) thrombus removal system in concert with ECMO to remove a large thrombus adherent to an ECMO cannula. PMID:26034197

  10. Spontaneous echo contrast masking thrombus in giant left atrium of mitral stenosis-a dilemma in clinical diagnosis.

    PubMed

    Islam, Akm Monwarul; Salam, Md Abdus; Sayeed, Md Zahidus; Kibria, Md Golam

    2015-01-01

    Spontaneous echo contrast (SEC) and thrombus in enlarged left atrium (LA) are common in mitral valvular disease (MVD) and SEC is considered to be a prethrombotic condition. Reliable exclusion of LA thrombus is important before any definitive curative attempts like percutaneous transluminal mitral commissurotomy (PTMC), closed mitral commissurotomy (CMC) or innovative therapies like pulmonary vein isolation and percutaneous closure of the LA appendage. Echocardiography, particularly the transesophageal echocardiography (TEE) is considered to be the gold standard for the diagnosis and to exclude LA thrombus. However, LA thrombus may remain rarely undetected even by TEE potentially making the interventions a risky job. We present a case of mitral stenosis (MS) with giant LA where profuse, dense SEC masked the underlying thrombus in the LA cavity. PMID:26649032

  11. Spontaneous echo contrast masking thrombus in giant left atrium of mitral stenosis-a dilemma in clinical diagnosis

    PubMed Central

    Islam, AKM Monwarul; Salam, Md. Abdus; Sayeed, Md. Zahidus; Kibria, Md. Golam

    2015-01-01

    Spontaneous echo contrast (SEC) and thrombus in enlarged left atrium (LA) are common in mitral valvular disease (MVD) and SEC is considered to be a prethrombotic condition. Reliable exclusion of LA thrombus is important before any definitive curative attempts like percutaneous transluminal mitral commissurotomy (PTMC), closed mitral commissurotomy (CMC) or innovative therapies like pulmonary vein isolation and percutaneous closure of the LA appendage. Echocardiography, particularly the transesophageal echocardiography (TEE) is considered to be the gold standard for the diagnosis and to exclude LA thrombus. However, LA thrombus may remain rarely undetected even by TEE potentially making the interventions a risky job. We present a case of mitral stenosis (MS) with giant LA where profuse, dense SEC masked the underlying thrombus in the LA cavity. PMID:26649032

  12. The insulin-like growth factor 1 receptor (IGF1R) contributes to reduced size in dogs

    PubMed Central

    Hoopes, Barbara C.; Rimbault, Maud; Liebers, David; Ostrander, Elaine A.

    2012-01-01

    Domestic dog breeds have undergone intense selection for a variety of morphologic features, including size. Among small-dog breeds, defined as those averaging less than ~15 in. at the withers, there remains still considerable variation in body size. Yet essentially all such dogs are fixed for the same allele at the insulin-like growth factor 1 gene, which we and others previously found to be a size locus of large effect. In this study we sought to identify additional genes that contribute to tiny size in dogs using an association scan with the single nucleotide polymorphism (SNP) dataset CanMap, in which 915 purebred dogs were genotyped at 60,968 SNP markers. Our strongest association for tiny size (defined as breed-average height not more than 10 in. at the withers) was on canine chromosome 3 (p = 1.9 × 10−70). Fine mapping revealed a nonsynonymous SNP at chr3:44,706,389 that changes a highly conserved arginine at amino acid 204 to histidine in the insulin-like growth factor 1 receptor (IGF1R). This mutation is predicted to prevent formation of several hydrogen bonds within the cysteine-rich domain of the receptor’s ligand-binding extracellular subunit. Nine of 13 tiny dog breeds carry the mutation and many dogs are homozygous for it. This work underscores the central importance of the IGF1 pathway in controlling the tremendous size diversity of dogs. PMID:22903739

  13. Differences in thrombus structure and kinetics in patients with type 2 diabetes mellitus after non ST elevation acute coronary syndrome

    PubMed Central

    Viswanathan, Girish N.; Marshall, Sally M.; Balasubramaniam, Karthik; Badimon, Juan J.; Zaman, Azfar G.

    2014-01-01

    Introduction Despite optimal secondary prevention therapy following non-ST elevation acute coronary syndrome (NSTE-ACS), recurrent thrombotic events are more frequent in patients with type 2 diabetes mellitus (T2DM). Materials and Methods This exploratory study was aimed to evaluate quantitative and qualitative aspects of thrombus. In 28 patients with and without T2DM treated with aspirin and clopidogrel we assessed thrombus quantity using an ex-vivo chamber, platelet reactivity, thrombus ultrastructure and thrombus kinetics one week after NSTE-ACS. Results T2DM was associated with increased thrombus [14861 (8003 to 30161) vs 8908 (6812 to 11996), μ2/mm, median (IQR), p = 0.045] and platelet reactivity. In addition, diabetic thrombus showed lower visco-elastic tensile strength [(− 0.2(− 1.7 to 0.7) vs 1.0(− 0.9 to 3.3), p = 0.044)] and was more resistant to autolysis [(27.8(11.7 to 70.7) vs 78.8(68.5 to109.6) mm/min, p = 0.002)]. On SEM, fibrin fibres in diabetes were thinner, with higher lateral interlinkage and mesh-like organisation. Thrombus quantity correlated inversely with thrombus retraction (r = − 0.450 p = 0.016) but not with platelet reactivity (r = 0.153, p = 0.544). Conclusions Despite optimal antiplatelet therapy, T2DM patients after NSTE-ACS developed increased thrombus of lower tensile strength and slower retraction. SEM revealed loosely arranged fibrin fibres. Our data showed significant differences in the magnitude as well as structural and mechanistic characteristics of thrombus in patients with T2DM. PMID:24582462

  14. Renal Dysfunction on Admission Predicts No-Reflow Phenomenon in Patients Undergoing Manual Thrombus Aspiration during Primary Percutaneous Coronary Intervention

    PubMed Central

    Sensoy, Baris; Uzunget, Sezen Baglan; Acikgoz, SadikKadri; Sensoy, Nur; Sen, Fatih; Acar, Burak; Canpolat, Uğur; Ozeke, Ozcan; Cay, Serkan; Maden, Orhan

    2016-01-01

    Background No-reflow is a frequent complication during percutaneous coronary intervention (PCI) for acute ST segment elevation myocardial infarction (STEMI). Available data is limited regarding its impact on short-term outcomes in patients undergoing manual thrombus aspiration. Renal impairment is also associated with higher complication rates in STEMI. Herein, we aimed to evaluate the impact of baseline renal dysfunction on the no- reflow phenomenon and the association of no-reflow phenomenon with early clinical outcomes. Methods A total of 94 consecutive STEMI patients who underwent primary stent-based PCI and thrombus aspiration were enrolled. No-reflow was established by the use of angiographic and electrocardiographic reperfusion criteria, respectively. Additionally angiographic and clinical follow-up data were also recorded. Results In our study, the no-reflow phenomenon was observed in 10 patients (11%) angiographically and in 23 patients (24%) electrocardiographically. Whereas, the the estimated glomerular filtration rate (eGFR) [odds ratio (OR) 10.4], hypertension (OR 6.2), previous MI (OR 6.5), previous PCI history, (OR 4.2), predilatation (OR 7.2), final balloon pressure (OR 0.9) were found to be the significant predictors of angiographic no-reflow, only reperfusion time was the predictor of electrocardiographic no-reflow (OR 1.12) at univariate analysis. After adjustment, lower eGFR (OR 14.8) was found to be the independent predictor for angiographic no-reflow. In-hospital mortality was more common in patients with either no-reflow condition separately. Conclusions Longer ischemic time and lower initial eGFR values were associated with no-reflow phenomenon. Irrespective of poor reperfusion criteria, no-reflow phenomenon is associated with in-hospital outcome. Future efforts should be made to reduce the incidence of no-reflow especially in patients with lower initial eGFR values. PMID:27122949

  15. The ability of winter grazing to reduce wildfire size, intensity, and fire-induced plant mortality was not demonstrated: a comment on Davies et al. (2015)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior and intensity metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience fire-induced mortality of native perennial bunchg...

  16. The ability of winter grazing to reduce wildfire size, intensity, and fire-induced plant mortality was not demonstrated: A comment on Davies et al. (2015)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior and intensity metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience fire-induced mortality of native perennial bunchg...

  17. The ability of winter grazing to reduce wildfire size, intensity, and fire-induced plant mortality was not demonstrated: A comment on Davies et al. (2015)

    EPA Science Inventory

    A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience more fire-induced mortality of native peren...

  18. A Thrombus Generation Model Applied to Aneurysms Treated with Shape Memory Polymer Foam and Metal Coils

    NASA Astrophysics Data System (ADS)

    Horn, John; Ortega, Jason; Hartman, Jonathan; Maitland, Duncan

    2015-11-01

    To prevent their rupture, intracranial aneurysms are often treated with endovascular metal coils which fill the aneurysm sac and isolate it from the arterial flow. Despite its widespread use, this method can result in suboptimal outcomes leading to aneurysm recurrence. Recently, shape memory polymer foam has been proposed as an alternative aneurysm filler. In this work, a computational model has been developed to predict thrombus formation in blood in response to such cardiovascular implantable devices. The model couples biofluid and biochemical phenomena present as the blood interacts with a device and stimulates thrombus formation. This model is applied to simulations of both metal coil and shape memory polymer foam treatments within an idealized 2D aneurysm geometry. Using the predicted thrombus responses, the performance of these treatments is evaluated and compared. The results suggest that foam-treated aneurysms may fill more quickly and more completely with thrombus than coil-filled aneurysms, potentially leading to improved long-term aneurysm healing. This work was performed in part under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  19. A systems approach to hemostasis: 2. Computational analysis of molecular transport in the thrombus microenvironment

    PubMed Central

    Tomaiuolo, Maurizio; Stalker, Timothy J.; Welsh, John D.; Diamond, Scott L.; Sinno, Talid

    2014-01-01

    Hemostatic thrombi formed after a penetrating injury have a heterogeneous architecture in which a core of highly activated, densely packed platelets is covered by a shell of less-activated, loosely packed platelets. In the first manuscript in this series, we show that regional differences in intrathrombus protein transport rates emerge early in the hemostatic response and are preserved as the thrombus develops. Here, we use a theoretical approach to investigate this process and its impact on agonist distribution. The results suggest that hindered diffusion, rather than convection, is the dominant mechanism responsible for molecular movement within the thrombus. The analysis also suggests that the thrombus core, as compared with the shell, provides an environment for retaining soluble agonists such as thrombin, affecting the extent of platelet activation by establishing agonist-specific concentration gradients radiating from the site of injury. This analysis accounts for the observed weaker activation and relative instability of platelets in the shell and predicts that a failure to form a tightly packed thrombus core will limit thrombin accumulation, a prediction tested by analysis of data from mice with a defect in clot retraction. PMID:24951425

  20. A Computational Model of Biochemomechanical Effects of Intraluminal Thrombus on the Enlargement of Abdominal Aortic Aneurysms.

    PubMed

    Virag, Lana; Wilson, John S; Humphrey, Jay D; Karšaj, Igor

    2015-12-01

    Abdominal aortic aneurysms (AAAs) typically develop an intraluminal thrombus (ILT), yet most computational models of AAAs have focused on either the mechanics of the wall or the hemodynamics within the lesion, both in the absence of ILT. In the few cases wherein ILT has been modeled directly, as, for example, in static models that focus on the state of stress in the aortic wall and the associated rupture risk, thrombus has been modeled as an inert, homogeneous, load-bearing material. Given the biochemomechanical complexity of an ILT, there is a pressing need to consider its diverse effects on the evolving aneurysmal wall. Herein, we present the first growth and remodeling model that addresses together the biomechanics, mechanobiology, and biochemistry of thrombus-laden AAAs. Whereas it has been shown that aneurysmal enlargement in the absence of ILT depends primarily on the stiffness and turnover of fibrillar collagen, we show that the presence of a thrombus within lesions having otherwise the same initial wall composition and properties can lead to either arrest or rupture depending on the biochemical effects (e.g., release of proteases) and biomechanical properties (e.g., stiffness of fibrin) of the ILT. These computational results suggest that ILT should be accounted for when predicting the potential enlargement or rupture risk of AAAs and highlight specific needs for further experimental and computational research. PMID:26070724

  1. Role of intracoronary thrombus in acute complications during percutaneous transluminal coronary angioplasty.

    PubMed

    Arora, R R; Platko, W P; Bhadwar, K; Simpfendorfer, C

    1989-04-01

    Coronary angiograms from 2,372 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) were retrospectively reviewed for the presence of intracoronary thrombus (ICT) before dilatation. Patients with evolving acute myocardial infarction and those receiving thrombolytic therapy were excluded from analysis. Coronary artery thrombus was present in 126 patients (6%) (group 1). When compared to 2,246 patients (group 2) without ICT, group 1 had a higher incidence of unstable angina, 74% vs. 66% (less than 0.06), previous myocardial infarction, 59% vs. 37% (P less than .0001), and history of a recent myocardial infarction, 28% vs. 9% (P less than .0001). Patients with predilatation intracoronary thrombus had a higher risk for acute occlusion, 6% vs. 2% (P less than .002); however, the incidence of emergency coronary bypass surgery and myocardial infarction was similar in both groups. Therefore, the presence of predilatation intracoronary thrombus heralds an increased risk of acute occlusion, but not myocardial infarction or emergency coronary artery bypass surgery. PMID:2523243

  2. Closure of Left Atrial Appendage With Persistent Distal Thrombus Using an Amplatzer Amulet Occluder.

    PubMed

    Lange, Mathias; Bültel, Helmut; Weglage, Heinrich; Löffeld, Patrick; Wichter, Thomas

    2016-09-01

    A 73-year-old patient with permanent atrial fibrillation presented for left atrial appendage (LAA) occlusion. Transesophageal echocardiography demonstrated a thrombus in the distal LAA. This image series illustrates a "no touch" technique that was used to ensure successful implantation of an Amplatzer Amulet LAA occlusion device without the use of an embolization protection system. PMID:27591691

  3. Discrete element method modeling of the triboelectric charging of polyethylene particles: Can particle size distribution and segregation reduce the charging?

    NASA Astrophysics Data System (ADS)

    Konopka, Ladislav; Kosek, Juraj

    2015-10-01

    Polyethylene particles of various sizes are present in industrial gas-dispersion reactors and downstream processing units. The contact of the particles with a device wall as well as the mutual particle collisions cause electrons on the particle surface to redistribute in the system. The undesirable triboelectric charging results in several operational problems and safety risks in industrial systems, for example in the fluidized-bed polymerization reactor. We studied the charging of polyethylene particles caused by the particle-particle interactions in gas. Our model employs the Discrete Element Method (DEM) describing the particle dynamics and incorporates the ‘Trapped Electron Approach’ as the physical basis for the considered charging mechanism. The model predicts the particle charge distribution for systems with various particle size distributions and various level of segregation. Simulation results are in a qualitative agreement with experimental observations of similar particulate systems specifically in two aspects: 1) Big particles tend to gain positive charge and small particles the negative one. 2) The wider the particle size distribution is, the more pronounced is the charging process. Our results suggest that not only the size distribution, but also the effect of the spatial segregation of the polyethylene particles significantly influence the resulting charge distribution ‘generated’ in the system. The level of particle segregation as well as the particle size distribution of polyethylene particles can be in practice adjusted by the choice of supported catalysts, by the conditions in the fluidized-bed polymerization reactor and by the fluid dynamics. We also attempt to predict how the reactor temperature affects the triboelectric charging of particles.

  4. Echocardiographic detection of free-floating thrombus in left ventricle during coronary artery bypass grafting

    PubMed Central

    Vaggar, Jagadeesh N.; Gadhinglajkar, Shrinivas; Pillai, Vivek; Sreedhar, Rupa; Cahndran, Roshith; Roy, Suddhadeb

    2015-01-01

    We report an incident of detection of a free-floating thrombus in the left ventricle (LV) using intraoperative two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE) during proximal coronary artery bypass graft anastomosis. A 58-year-old man presented to us with a 6-month history of chest pain without any history suggestive of myocardial infarction or transient ischemic attacks. His preoperative echocardiography revealed the systolic dysfunction of LV, mild hypokinesia of basal and mid-anterior wall, and the absence of an aneurysm. He was scheduled for on-pump coronary artery bypass surgery. On intraoperative TEE before establishing cardiopulmonary bypass (CPB), a small immobile mass was found attached to LV apical area. After completion of distal coronary artery grafting, when the aortic cross-clamp was removed, the heart was filled partially and beating spontaneously. TEE examination using 2D mode revealed a free-floating mass in the LV, which was suspected to be a thrombus. Additional navigation using biplane and 3D modes confirmed the presence of the thrombus and distinguished it from papillary muscles and artifact. The surgeon opened the left atrium after re-establishing electromechanical quiescence and removed a thrombus measuring 1.5 cm × 1 cm from the LV. The LV mass in the apical region was no longer seen after discontinuation of CPB. Accurate TEE-detection and timely removal of the thrombus averted disastrous embolic complications. Intraoperative 2D and recent biplane and 3D echocardiography modes are useful monitoring tools during the conduct of CPB. PMID:26440248

  5. Dendritic nonlinearities reduce network size requirements and mediate ON and OFF states of persistent activity in a PFC microcircuit model.

    PubMed

    Papoutsi, Athanasia; Sidiropoulou, Kyriaki; Poirazi, Panayiota

    2014-07-01

    Technological advances have unraveled the existence of small clusters of co-active neurons in the neocortex. The functional implications of these microcircuits are in large part unexplored. Using a heavily constrained biophysical model of a L5 PFC microcircuit, we recently showed that these structures act as tunable modules of persistent activity, the cellular correlate of working memory. Here, we investigate the mechanisms that underlie persistent activity emergence (ON) and termination (OFF) and search for the minimum network size required for expressing these states within physiological regimes. We show that (a) NMDA-mediated dendritic spikes gate the induction of persistent firing in the microcircuit. (b) The minimum network size required for persistent activity induction is inversely proportional to the synaptic drive of each excitatory neuron. (c) Relaxation of connectivity and synaptic delay constraints eliminates the gating effect of NMDA spikes, albeit at a cost of much larger networks. (d) Persistent activity termination by increased inhibition depends on the strength of the synaptic input and is negatively modulated by dADP. (e) Slow synaptic mechanisms and network activity contain predictive information regarding the ability of a given stimulus to turn ON and/or OFF persistent firing in the microcircuit model. Overall, this study zooms out from dendrites to cell assemblies and suggests a tight interaction between dendritic non-linearities and network properties (size/connectivity) that may facilitate the short-memory function of the PFC. PMID:25077940

  6. Dendritic Nonlinearities Reduce Network Size Requirements and Mediate ON and OFF States of Persistent Activity in a PFC Microcircuit Model

    PubMed Central

    Papoutsi, Athanasia; Sidiropoulou, Kyriaki; Poirazi, Panayiota

    2014-01-01

    Technological advances have unraveled the existence of small clusters of co-active neurons in the neocortex. The functional implications of these microcircuits are in large part unexplored. Using a heavily constrained biophysical model of a L5 PFC microcircuit, we recently showed that these structures act as tunable modules of persistent activity, the cellular correlate of working memory. Here, we investigate the mechanisms that underlie persistent activity emergence (ON) and termination (OFF) and search for the minimum network size required for expressing these states within physiological regimes. We show that (a) NMDA-mediated dendritic spikes gate the induction of persistent firing in the microcircuit. (b) The minimum network size required for persistent activity induction is inversely proportional to the synaptic drive of each excitatory neuron. (c) Relaxation of connectivity and synaptic delay constraints eliminates the gating effect of NMDA spikes, albeit at a cost of much larger networks. (d) Persistent activity termination by increased inhibition depends on the strength of the synaptic input and is negatively modulated by dADP. (e) Slow synaptic mechanisms and network activity contain predictive information regarding the ability of a given stimulus to turn ON and/or OFF persistent firing in the microcircuit model. Overall, this study zooms out from dendrites to cell assemblies and suggests a tight interaction between dendritic non-linearities and network properties (size/connectivity) that may facilitate the short-memory function of the PFC. PMID:25077940

  7. N-acetylcysteine reduces the size and activity of von Willebrand factor in human plasma and mice.

    PubMed

    Chen, Junmei; Reheman, Adili; Gushiken, Francisca C; Nolasco, Leticia; Fu, Xiaoyun; Moake, Joel L; Ni, Heyu; López, José A

    2011-02-01

    Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease characterized by systemic microvascular thrombosis caused by adhesion of platelets to ultra-large vWF (ULVWF) multimers. These multimers accumulate because of a deficiency of the processing enzyme ADAMTS13. vWF protein forms long multimers from homodimers that first form through C-terminal disulfide bonds and then join through their N termini by further disulfide bonding. N-acetylcysteine (NAC) is an FDA-approved drug that has long been used to treat chronic obstructive lung disease and acetaminophen toxicity and is known to function in the former disorder by reducing mucin multimers. Here, we examined whether NAC could reduce vWF multimers, which polymerize in a manner similar to mucins. In vitro, NAC reduced soluble plasma-type vWF multimers in a concentration-dependent manner and rapidly degraded ULVWF multimer strings extruded from activated ECs. The effect was preceded by reduction of the intrachain disulfide bond encompassing the platelet-binding A1 domain. NAC also inhibited vWF-dependent platelet aggregation and collagen binding. Injection of NAC into ADAMTS13-deficient mice led to the rapid resolution of thrombi produced by ionophore treatment of the mesenteric venules and reduced plasma vWF multimers. These results suggest that NAC may be a rapid and effective treatment for patients with TTP. PMID:21266777

  8. Novel treatment of coronary artery fistulae concealing severe coronary artery lesion: using thrombus aspiration catheter as a delivery guide.

    PubMed

    Korkmaz, Levent; Acar, Zeydin; Dursun, Ihsan; Akyüz, Ali Rıza; Korkmaz, Ayca Ata

    2014-03-01

    In this case report, we present the occlusion of multiple coronary artery fistulae originating from proximal left anterior descending (LAD) and right sinus valsavla and empting to the pulmonary artery at the same place. We occluded LAD fistulae by using thrombus aspiration catheter as a delivery guide. To the best of our knowlege, this is the first case of occlusion of coronary fistulae with the help of thrombus aspiration catheter. Our experience may suggest that thrombus aspiration catheters can be used in treating coronary artery fistulae with difficult anotomy. PMID:24748888

  9. Novel treatment of coronary artery fistulae concealing severe coronary artery lesion: using thrombus aspiration catheter as a delivery guide

    PubMed Central

    Korkmaz, Levent; Acar, Zeydin; Dursun, İhsan; Akyüz, Ali Rıza; Korkmaz, Ayca Ata

    2014-01-01

    In this case report, we present the occlusion of multiple coronary artery fistulae originating from proximal left anterior descending (LAD) and right sinus valsavla and empting to the pulmonary artery at the same place. We occluded LAD fistulae by using thrombus aspiration catheter as a delivery guide. To the best of our knowlege, this is the first case of occlusion of coronary fistulae with the help of thrombus aspiration catheter. Our experience may suggest that thrombus aspiration catheters can be used in treating coronary artery fistulae with difficult anotomy. PMID:24748888

  10. Salt Stress Reduces Root Meristem Size by Nitric Oxide-Mediated Modulation of Auxin Accumulation and Signaling in Arabidopsis1[OPEN

    PubMed Central

    Liu, Wen; Li, Rong-Jun; Han, Tong-Tong; Cai, Wei; Fu, Zheng-Wei

    2015-01-01

    The development of the plant root system is highly plastic, which allows the plant to adapt to various environmental stresses. Salt stress inhibits root elongation by reducing the size of the root meristem. However, the mechanism underlying this process remains unclear. In this study, we explored whether and how auxin and nitric oxide (NO) are involved in salt-mediated inhibition of root meristem growth in Arabidopsis (Arabidopsis thaliana) using physiological, pharmacological, and genetic approaches. We found that salt stress significantly reduced root meristem size by down-regulating the expression of PINFORMED (PIN) genes, thereby reducing auxin levels. In addition, salt stress promoted AUXIN RESISTANT3 (AXR3)/INDOLE-3-ACETIC ACID17 (IAA17) stabilization, which repressed auxin signaling during this process. Furthermore, salt stress stimulated NO accumulation, whereas blocking NO production with the inhibitor Nω-nitro-l-arginine-methylester compromised the salt-mediated reduction of root meristem size, PIN down-regulation, and stabilization of AXR3/IAA17, indicating that NO is involved in salt-mediated inhibition of root meristem growth. Taken together, these findings suggest that salt stress inhibits root meristem growth by repressing PIN expression (thereby reducing auxin levels) and stabilizing IAA17 (thereby repressing auxin signaling) via increasing NO levels. PMID:25818700

  11. Marine reserves reduce risk of climate-driven phase shift by reinstating size- and habitat-specific trophic interactions.

    PubMed

    Ling, S D; Johnson, C R

    2012-06-01

    Spatial closures in the marine environment are widely accepted as effective conservation and fisheries management tools. Given increasing human-derived stressors acting on marine ecosystems, the need for such effective action is urgently clear. Here we explore mechanisms underlying the utility of marine reserves to reinstate trophic dynamics and to increase resilience of kelp beds against climate-driven phase shift to sea urchin barrens on the rapidly warming Tasmanian east coast. Tethering and tagging experiments were used to examine size- and shelter-specific survival of the range-extending sea urchin Centrostephanus rodgersii (Diadematidae) translocated to reefs inside and outside no-take Tasmanian marine reserves. Results show that survival rates of C. rodgersii exposed on flat reef substratum by tethering were approximately seven times (small urchins 10.1 times; large urchins 6.1 times) lower on protected reef within marine reserve boundaries (high abundance of large predatory-capable lobsters) compared to fished reef (large predatory lobsters absent). When able to seek crevice shelter, tag-resighting models estimated that mortality rates of C. rodgersii were lower overall but remained 3.3 times (small urchins 2.1 times; large urchins 6.4 times) higher in the presence of large lobsters inside marine reserves, with higher survival of small urchins owing to greater access to crevices relative to large urchins. Indeed, shelter was 6.3 times and 3.1 times more important to survival of small and large urchins, respectively, on reserved relative to fished reef. Experimental results corroborate with surveys throughout the range extension region, showing greater occurrence of overgrazing on high-relief rocky habitats where shelter for C. rodgersii is readily available. This shows that ecosystem impacts mediated by range extension of such habitat-modifying organisms will be heterogeneous in space, and that marine systems with a more natural complement of large and thus

  12. Absorption and Bioavailability of Nano-Size Reduced Calcium Citrate Fortified Milk Powder in Ovariectomized and Ovariectomized-Osteoporosis Rats.

    PubMed

    Erfanian, Arezoo; Mirhosseini, Hamed; Rasti, Babak; Hair-Bejo, Mohd; Bin Mustafa, Shuhaimi; Abd Manap, Mohd Yazid

    2015-06-24

    The aim of this study was to evaluate the effects of fortification and nano-size reduction on calcium absorption and bioavailability of milk powder formula in sham, ovariectomized, and ovariectomized-osteoporosis rats as a menopause and menopause-osteoporosis model. Skim milk powder and skim milk powder fortified with calcium citrate and the suitable doses of inulin, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and vitamins D3, K1, and B6 were formulated based on the North American and Western European recommended dietary allowances. Optimization on cycle and pressure of high-pressure homogenizer was done to produce nano-fortified milk powder. In vivo study demonstrated that fortification and calcium citrate nano-fortified milk powder increased absorption and bioavailability of calcium, as well as bone stiffness and bone strength in sham, ovariectomized, and ovariectomized-osteoporosis rats. This study successfully developed an effective fortified milk powder for food application. PMID:26022498

  13. Reduced size of ordered moments of a quasi 1d antiferromagnet Sr{sub 2}CuO{sub 3}

    SciTech Connect

    Kojima, K.; Larkin, M.; Luke, G.M.

    1996-09-01

    The quasi one-dimensional antiferromagnet Sr{sub 2}CuO{sub 3} exhibits Neel order of Cu{sup 2+} moments (S = 1/2) at T{sub N} = 5.41(1) K, as demonstrated by (1) almost resolution-limited magnetic Bragg reflections in neutron scattering measurements, and (2) spontaneous muon spin precession in zero-field muon spin relaxation ({mu}SR) measurements. The temperature dependence of the order parameters are consistent between the two experimental techniques. From the neutron data, the authors obtained an upper-limit for the ordered moment size of {approximately} 0.06 {mu}{sub B}. This indicates a significant moment reduction from quantum fluctuations.

  14. Sizing community energy storage systems to reduce transformer overloading with emphasis on plug-in electric vehicle loads

    NASA Astrophysics Data System (ADS)

    Trowler, Derik Wesley

    The research objective of this study was to develop a sizing method for community energy storage systems with emphasis on preventing distribution transformer overloading due to plug-in electric vehicle charging. The method as developed showed the formulation of a diversified load profile based upon residential load data for several customers on the American Electric Power system. Once a load profile was obtained, plug-in electric vehicle charging scenarios which were based upon expected adoption and charging trends were superimposed on the load profile to show situations where transformers (in particular 25 kVA, 50 kVA, and 100 kVA) would be overloaded during peak hours. Once the total load profiles were derived, the energy and power requirements of community energy storage systems were calculated for a number of scenarios with different combinations of numbers of homes and plug-in electric vehicles. The results were recorded and illustrated into charts so that one could determine the minimum size per application. Other topics that were covered in this thesis were the state of the art and future trends in plug-in electric vehicle and battery chemistry adoption and development. The goal of the literature review was to confirm the already suspected notion that Li-ion batteries are best suited and soon to be most cost-effective solution for applications requiring small, efficient, reliable, and light-weight battery systems such as plug-in electric vehicles and community energy storage systems. This thesis also includes a chapter showing system modeling in MATLAB/SimulinkRTM. All in all, this thesis covers a wide variety of considerations involved in the designing and deploying of community energy storage systems intended to mitigate the effects of distribution transformer overloading.

  15. Increased left atrial size is associated with reduced atrial stiffness and preserved reservoir function in athlete's heart.

    PubMed

    D'Ascenzi, Flavio; Pelliccia, Antonio; Natali, Benedetta Maria; Cameli, Matteo; Andrei, Valentina; Incampo, Eufemia; Alvino, Federico; Lisi, Matteo; Padeletti, Margherita; Focardi, Marta; Bonifazi, Marco; Mondillo, Sergio

    2015-04-01

    Left atrial (LA) fibrosis with increased stiffness has been assumed to be the substrates for occurrence of atrial arrhythmias in athletes. However, this hypothesis has not yet been confirmed in humans. Aim of this study was, therefore, to assess LA remodeling and stiffness in competitive athletes. 150 competitive athletes and 90 age and sex-matched sedentary subjects were analyzed by speckle-tracking echocardiography to measure peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS). LA stiffness was determined using E/e' ratio in conjunction with PALS. Left ventricular (LV) stiffness was also calculated. LA volume index was greater in athletes as compared with controls (24.6 ± 7.3 vs. 18.4 ± 7.8 mL/m(2), p < .0001). LA PALS, LA PACS, and E/e' ratio were lower in athletes in comparison with controls (p < .05, p ≤ .001, and p < .0001, respectively). Despite greater LA size, competitive athletes had lower LA stiffness as compared with controls (0.13 ± 0.04 vs. 0.16 ± 0.06, p ≤ .001). In addition, LV stiffness was lower in athletes (0.84 ± 0.27 vs. 1.07 ± 0.46, p ≤ .001). The only independent predictor of LA stiffness was LV stiffness (β = 0.46, p < .0001), while the only independent predictor of LA volume index was LV end-systolic volume index (β = 0.25, p = .002). Competitive athletes showed greater LA size associated with lower stiffness as compared with controls. Thus, LA remodeling in the context of the athlete's heart is not associated with increased LA stiffness. These findings support the benign nature of LA remodeling in athletes, occurring as a physiological adaptation to exercise conditioning. PMID:25627780

  16. Treatment with anti-RANKL antibody reduces infarct size and attenuates dysfunction impacting on neutrophil-mediated injury.

    PubMed

    Carbone, Federico; Crowe, Lindsey A; Roth, Aline; Burger, Fabienne; Lenglet, Sébastien; Braunersreuther, Vincent; Brandt, Karim J; Quercioli, Alessandra; Mach, François; Vallée, Jean-Paul; Montecucco, Fabrizio

    2016-05-01

    Selective pharmacological treatments targeting reperfusion injury produced modest protective effects and might be associated with immunosuppression. In order to identify novel and better-tolerated approaches, we focused on the neutralization of receptor activator of nuclear factor kappa-B ligand [RANKL], a cytokine recently shown to activate inflammatory cells (i.e. neutrophils) orchestrating post-infarction injury and repair. Myocardial ischemia (60min) and reperfusion injury was surgically induced in C57Bl/6 mice. In hearts and serum, RANKL was early upregulated during reperfusion. A "one-shot" injection with neutralizing anti-RANKL IgG during ischemia ameliorated myocardial infarct size and function, but not adverse remodeling (determined by Magnetic Resonance Imaging [MRI]) as compared to Vehicle or control IgG. These beneficial effects were accompanied in vivo by reduction in cardiac neutrophil infiltration, reactive oxygen species (ROS) and MMP-9 release. Anti-RANKL IgG treatment suppressed sudden peak of neutrophil granule products in mouse serum early after reperfusion onset. In vitro, RANK mRNA expression was detected in isolated mouse neutrophils. Co-incubation with neutralizing anti-RANKL IgG abrogated RANKL-induced mouse neutrophil degranulation and migration, suggesting a critical role of RANKL in neutrophil-mediated injury. Conversely, anti-RANKL IgG did not affect salvage pathways in cardiac cells (i.e. ERK p42/p44, Akt and STAT-3) or macrophage cardiac infiltration. Finally, treatment with anti-RANKL IgG showed no effect on B and T lymphocyte polarization (in serum, spleen and infarcted myocardium) and circulating chemokines as compared with Vehicle or control IgG. In conclusion, acute treatment with anti-RANKL IgG improved cardiac infarct size and function by potentially impacting on neutrophil-mediated injury and repair. PMID:27056420

  17. Role of 5-hydroxytryptamine in platelet thrombus formation and mechanisms of inhibition of thrombus formation by 5-hydroxytryptamine2A antagonists in rabbits.

    PubMed

    Takano, S

    1995-01-01

    The role of 5-hydroxytryptamine (5-HT) in platelet thrombus formation and in the mechanisms of inhibition of thrombus formation by 5-HT2A antagonists was investigated using a turbidimetric method. Collagen-induced platelet aggregation occurred simultaneously with a release of 5-HT from the platelets. The supernatant of collagen-aggregated platelets induced a further aggregation volume-dependently. This supernatant-induced aggregation was inhibited by either 5-HT2A antagonists or adenosine-diphosphate (ADP) scavenging. 5-Hydroxytryptamine and a small amount of the supernatant shifted the dose-response curves of collagen to the left. The aggregation velocity and the onset of aggregation by collagen were significantly increased by the supernatant, but not by 5-HT. The 5-HT2A antagonists, ketanserin and MCI-9042, returned the dose-response curves of the maximum aggregation and of the aggregation velocity of collagen, which were already amplified by the supernatant, to the original values. The onset of aggregation was delayed by the antagonists, but was not completely returned to the original points. There were distinct differences between the effects of endogenous 5-HT, derived from platelets which were stimulated by collagen, and those of exogenous 5-HT on both extensive platelet activation and amplification of the collagen-induced aggregation. These findings suggest that endogenous 5-HT activates platelets in synergism with ADP. The 5-HT2A antagonists used, block the synergism via 5-HT2A receptors and lead to inhibition of a positive feedback loop of thrombus formation. PMID:8836449

  18. Angiogenesis Is Induced and Wound Size Is Reduced by Electrical Stimulation in an Acute Wound Healing Model in Human Skin

    PubMed Central

    Ud-Din, Sara; Sebastian, Anil; Giddings, Pamela; Colthurst, James; Whiteside, Sigrid; Morris, Julie; Nuccitelli, Richard; Pullar, Christine; Baguneid, Mo; Bayat, Ardeshir

    2015-01-01

    Angiogenesis is critical for wound healing. Insufficient angiogenesis can result in impaired wound healing and chronic wound formation. Electrical stimulation (ES) has been shown to enhance angiogenesis. We previously showed that ES enhanced angiogenesis in acute wounds at one time point (day 14). The aim of this study was to further evaluate the role of ES in affecting angiogenesis during the acute phase of cutaneous wound healing over multiple time points. We compared the angiogenic response to wounding in 40 healthy volunteers (divided into two groups and randomised), treated with ES (post-ES) and compared them to secondary intention wound healing (control). Biopsy time points monitored were days 0, 3, 7, 10, 14. Objective non-invasive measures and H&E analysis were performed in addition to immunohistochemistry (IHC) and Western blotting (WB). Wound volume was significantly reduced on D7, 10 and 14 post-ES (p = 0.003, p = 0.002, p<0.001 respectively), surface area was reduced on days 10 (p = 0.001) and 14 (p<0.001) and wound diameter reduced on days 10 (p = 0.009) and 14 (p = 0.002). Blood flow increased significantly post-ES on D10 (p = 0.002) and 14 (p = 0.001). Angiogenic markers were up-regulated following ES application; protein analysis by IHC showed an increase (p<0.05) in VEGF-A expression by ES treatment on days 7, 10 and 14 (39%, 27% and 35% respectively) and PLGF expression on days 3 and 7 (40% on both days), compared to normal healing. Similarly, WB demonstrated an increase (p<0.05) in PLGF on days 7 and 14 (51% and 35% respectively). WB studies showed a significant increase of 30% (p>0.05) on day 14 in VEGF-A expression post-ES compared to controls. Furthermore, organisation of granulation tissue was improved on day 14 post-ES. This randomised controlled trial has shown that ES enhanced wound healing by reduced wound dimensions and increased VEGF-A and PLGF expression in acute cutaneous wounds, which further substantiates the role of ES in up

  19. Chromium-Modified Li4Ti5O12 with a Synergistic Effect of Bulk Doping, Surface Coating, and Size Reducing.

    PubMed

    Zou, Hailin; Liang, Xin; Feng, Xuyong; Xiang, Hongfa

    2016-08-24

    Bulk doping, surface coating, and size reducing are three strategies for improving the electrochemical properties of Li4Ti5O12 (LTO). In this work, chromium (Cr)-modified LTO with a synergistic effect of bulk doping, surface coating, and size reducing is synthesized by a facile sol-gel method. X-ray diffraction (XRD) and Raman analysis prove that Cr dopes into the LTO bulk lattice, which effectively inhibits the generation of TiO2 impurities. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) verifies the surface coating of Li2CrO4 on the LTO surface, which decreases impedance of the LTO electrode. More importantly, the size of LTO particles can be significantly reduced from submicroscale to nanoscale as a result of the protection of the Li2CrO4 surface layer and the suppression from Cr atoms on the long-range order in the LTO lattice. As anode material, Li4-xCr3xTi5-2xO12 (x = 0.1) delivers a reversible capacity of 141 mAh g(-1) at 10 °C, and over 155 mAh g(-1) at 1 °C after 1000 cycles. Therefore, the Cr-modified Li4Ti5O12 prepared via a sol-gel method has potential for applications in high-power, long-life lithium-ion batteries. PMID:27479172

  20. Reduced molecular size and altered disaccharide composition of cerebral chondroitin sulfate upon Alzheimer’s pathogenesis in mice

    PubMed Central

    Zhang, Zui; Ohtake-Niimi, Shiori; Kadomatsu, Kenji; Uchimura, Kenji

    2016-01-01

    ABSTRACT Alzheimer’s disease (AD) is a progressive disorder leading to cognitive impairment and neuronal loss. Cerebral extracellular accumulation and deposition of amyloid ß plaques is a pathological hallmark of AD. Chondroitin sulfate (CS) is an extracellular component abundant in the brain. CS is a sulfated glycosaminoglycan covalently attached to a core protein, forming chondroitin sulfate proteoglycan. The structure of CS is heterogeneous with sulfation modification and elongation of the chain. The structural diversity of CS allows it to play various roles in the brain. Increasing evidence has shown that CS promotes aggregation of amyloid ß peptides into higher-order species such as insoluble amyloid ß fibrils. Difficulties in the structural analysis of brain CS, as well as its heterogeneity, limit the study of potential roles of CS in AD pathology. Here we established a microanalysis method with reversed-phase ion-pair high performance liquid chromatography and found that CS in the brains of Tg2576 AD model mice show a lower molecular size and an increased ratio of CS-B motif di-sulfated disaccharide. Our findings provide insight into the structural changes of cerebral CS upon Alzheimer’s pathogenesis. PMID:27578913

  1. Modified carbon fibers to improve composite properties. [sizing fibers for reduced electrical conductivity and adhesion during combustion

    NASA Technical Reports Server (NTRS)

    Shepler, R. E.

    1979-01-01

    Thin coatings, 5 to 10 wt. percent, were applied to PAN-based carbon fibers. These coatings were intended to make the carbon fibers less electrically conductive or to cause fibers to stick together when a carbon fiber/epoxy composite burned. The effectiveness of the coatings in these regards was evaluated in burn tests with a test rig designed to simulate burning, impact and wind conditions which might release carbon fibers. The effect of the coatings on fiber and composite properties and handling was also investigated. Attempts at sizing carbon fibers with silicon dioxide, silicon carbide and boron nitride meet with varying degrees of success; however, none of these materials provided an electrically nonconductive coating. Coatings intended to stick carbon fibers together after a composite burned were sodium silicate, silica gel, ethyl silicate, boric acid and ammonium borate. Of these, only the sodium silicate and silica gel provided any sticking together of fibers. The amount of sticking was insufficient to achieve the desired objectives.

  2. Plasma fibrin clot phenotype independently affects intracoronary thrombus ultrastructure in patients with acute myocardial infarction.

    PubMed

    Zalewski, Jaroslaw; Bogaert, Jan; Sadowski, Marcin; Woznicka, Olga; Doulaptsis, Konstantinos; Ntoumpanaki, Maria; Ząbczyk, Michal; Nessler, Jadwiga; Undas, Anetta

    2015-06-01

    Determinants of intracoronary thrombus (ICT) composition in patients with ST-elevation myocardial infarction (STEMI) are largely unknown. We sought to investigate whether plasma fibrin phenotype and platelet reactivity affect ICT ultrastructure. We assessed the content of fibrin, platelets and erythrocytes including polyhedrocytes by scanning electron microscopy on the surface and inside ICT aspirated from 80 STEMI patients within 12 hours since chest pain onset. Plasma fibrin clot permeability (Ks), which indicates the average pore size, lysis time (t50 %), platelet reactivity index (PRI) and ADP-induced platelet aggregation (ADP5, 20µM) were evaluated on admission. All patients received aspirin and 45 (56.3 %) 600 mg of clopidogrel, 80 (60-120) min prior to aspiration. Higher content of fibrin (61.6 vs 34.3 %, P< 0.0001) and platelets (8.2 vs 4.8 %, P=0.018) and lower erythrocyte content (15.8 vs 42.9 %, P< 0.0001) were found on ICT surface compared with its inner part. After adjustment for fibrinogen, in both ICT parts fibrin content was correlated with Ks (r≤-0.55, P< 0.0001) and t50 % (r≥ 0.29, P≤ 0.02) but not with PRI and ADP5,20µM. Polyhedrocytes were observed in 16 (20 %) patients and their large amount expressed as ≥ 50 % fields of view covered by polyhedrocytes was associated with the lower PRI values (40 vs 69 %, P=0.015), but not Ks or t50 %. By multivariate regression, Ks (β=-0.62, P< 0.0001), clopidogrel pretreatment (β=-0.36, P< 0.001), ischemia time (β=0.19, P=0.044) and family history (β=0.18, P=0.049) independently predicted fibrin content in the whole ICT (R²=0.65, P< 0.0001). Formation of denser plasma fibrin clots is independently associated with high fibrin content within the ICT in STEMI. PMID:25739375

  3. Assessment of a particle size fractionation as a technology for reducing heavy metal, salinity and impurities from compost produced by municipal solid waste.

    PubMed

    Sharifi, Zahed; Renella, Giancarlo

    2015-04-01

    A physical fractionation of a compost obtained by municipal solid wastes (MSW) was conducted by dry-sieving process, to quantify coarse impurities and assess the distribution of nutrients, heavy metals and salinity values in particle size fractions of 2, 1.2-2, 0.8-1.2, 0.4-0.8, 0.2-0.4, 0.1-0.2 and <0.1mm diameter. The whole unfractionated compost and all physical fractions were analyzed for the same chemical parameters. The results showed that the studied compost was of a low grade due to high salinity and heavy metal concentrations, and the presence of coarse impurities, mainly glass. The physical fractionation analysis showed that heavy metal and base cations concentrations, and salinity values significantly increased with decreasing of particle size, whereas macro nutrients such as C, N and P were more evenly distributed among the different particle size fractions. Overall, our results showed that the removal of selected particle size fractions <0.8mm and coarse impurities (e.g. glass impurity >2mm) could significantly improve the compost quality without reduce its fertilization potential. We concluded that particle size fractionation is a feasible and sustainable approach to improve composted MSW materials for their safe recycle in agriculture. PMID:25660906

  4. Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size.

    PubMed

    Keiser, Carl N; Wright, Colin M; Pruitt, Jonathan N

    2015-10-01

    Sociality provides individuals with benefits via collective foraging and anti-predator defense. One of the costs of living in large groups, however, is increased apparency to natural enemies. Here, we test how the individual-level and collective traits of spider societies can increase the risk of discovery and death by predatory ants. We transplanted colonies of the social spider Stegodyphus dumicola into a habitat dense with one of their top predators, the pugnacious ant Anoplolepis custodiens. With three different experiments, we test how colony-wide survivorship in a predator-dense habitat can be altered by colony apparency (i.e., the presence of a capture web), group size, and group composition (i.e., the proportion of bold and shy personality types present). We also test how spiders' social context (i.e., living solitarily vs. among conspecifics) modifies their behaviour toward ants in their capture web. Colonies with capture webs intact were discovered by predatory ants on average 25% faster than colonies with the capture web removed, and all discovered colonies eventually collapsed and succumbed to predation. However, the lag time from discovery by ants to colony collapse was greater for colonies containing more individuals. The composition of individual personality types in the group had no influence on survivorship. Spiders in a social group were more likely to approach ants caught in their web than were isolated spiders. Isolated spiders were more likely to attack a safe prey item (a moth) than they were to attack ants and were more likely to retreat from ants after contact than they were after contact with moths. Together, our data suggest that the physical structures produced by large animal societies can increase their apparency to natural enemies, though larger groups can facilitate a longer lag time between discovery and demise. Lastly, the interaction between spiders and predatory ants seems to depend on the social context in which spiders reside

  5. Breast Intensity-Modulated Radiation Therapy Reduces Time Spent With Acute Dermatitis for Women of All Breast Sizes During Radiation

    SciTech Connect

    Freedman, Gary M. Li Tianyu; Nicolaou, Nicos; Chen Yan; Ma, Charlie C.-M.; Anderson, Penny R.

    2009-07-01

    Purpose: To study the time spent with radiation-induced dermatitis during a course of radiation therapy for breast cancer in women treated with conventional or intensity-modulated radiation therapy (IMRT). Methods and Materials: The study population consisted of 804 consecutive women with early-stage breast cancer treated with breast-conserving surgery and radiation from 2001 to 2006. All patients were treated with whole-breast radiation followed by a boost to the tumor bed. Whole-breast radiation consisted of conventional wedged photon tangents (n = 405) earlier in the study period and mostly of photon IMRT (n = 399) in later years. All patients had acute dermatitis graded each week of treatment. Results: The breakdown of the cases of maximum acute dermatitis by grade was as follows: 3%, Grade 0; 34%, Grade 1; 61%, Grade 2; and 2%, Grade 3. The breakdown of cases of maximum toxicity by technique was as follows: 48%, Grade 0/1, and 52%, Grade 2/3, for IMRT; and 25%, Grade 0/1, and 75%, Grade 2/3, for conventional radiation therapy (p < 0.0001). The IMRT patients spent 82% of weeks during treatment with Grade 0/1 dermatitis and 18% with Grade 2/3 dermatitis, compared with 29% and 71% of patients, respectively, treated with conventional radiation (p < 0.0001). Furthermore, the time spent with Grade 2/3 toxicity was decreased in IMRT patients with small (p = 0.0015), medium (p < 0.0001), and large (p < 0.0001) breasts. Conclusions: Breast IMRT is associated with a significant decrease both in the time spent during treatment with Grade 2/3 dermatitis and in the maximum severity of dermatitis compared with that associated with conventional radiation, regardless of breast size.

  6. Comparison of 180-degree and 90-degree needle rotation to reduce wound size in PIT-injected juvenile Chinook salmon

    SciTech Connect

    Bryson, Amanda J.; Woodley, Christa M.; Karls, Rhonda K.; Hall, Kathleen D.; Weiland, Mark A.; Deng, Zhiqun; Carlson, Thomas J.; Eppard, Matthew B.

    2013-04-30

    Animal telemetry, which requires the implantation of passive transponders or active transmitters, is used to monitor and assess fish stock and conservation to gain an understanding of fish movement and behavior. As new telemetry technologies become available, studies of their effects on species of interest are imperative as is development of implantation techniques. In this study, we investigated the effects of bevel rotation (0-, 90-, 180-degree axis rotation) on wound extent, tag loss, and wound healing rates in juvenile Chinook salmon injected with an 8-gauge needle, which is required for implantation of the novel injectable Juvenile Salmon Acoustic Telemetry Systems (JSATS) acoustic transmitter or large passive integrated transponder (PIT) tags. Although the injection sites were not closed after injection (e.g., with sutures or glue), there were no mortalities, dropped tags, or indications of fungus, ulceration, and/or redness around the wound. On Day 0 and post-implantation Day 7, the 90-degree bevel rotation produced smaller wound extent than the 180-degree bevel rotation. No axis rotation (0-degrees) resulted in the PIT tag frequently misleading or falling out upon injection. The results of this study indicated the 90-degree bevel rotation was the more efficient technique, produced less wound extent. Given the wound extent compared to size of fish, we recommend researchers should consider a 90-degree rotation over the 180-degree rotation in telemetry studies. Highlights •Three degrees of needle rotation were examined for effects in Chinook salmon. •Mortality, tag loss, wound extent, healing, and infection indicators were measured. •There were no mortalities, tag loss, or indications of infection. •The 90-degree needle rotation through Day 7 produced the smallest wound extent.

  7. Adrenal cortical carcinoma with tumor thrombus extension into the right atrium: A case report

    PubMed Central

    WANG, YIMIN; ZHOU, FENG; PAN, HAO; JIN, BAIYE

    2016-01-01

    Adrenal cortical carcinoma (ACC) is a rare aggressive malignant tumor associated with a poor prognosis. Patients with ACC usually present with abnormal hormone secretion, tumor growth or encroachment on the surrounding viscera. An early diagnosis of ACC is considered challenging. The present study reports a case of ACC with tumor thrombus extension into the inferior vena cava and right atrium. A 33-year-old male patient exhibited symptoms of gynecomastia and abdominal distention, which were due to the abnormal hormone secretion levels and to the presence of a large mass in the right adrenal gland. An en bloc resection of the tumor was the selected treatment option. Extirpation of the tumor thrombus was performed by means of extracorporeal circulation. No signs of metastasis or recurrence were identified at the 1-month follow-up. PMID:27313728

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

    PubMed Central

    Kanjirakadavath, Babu; Krishnan, M.N.; Vinayakumar, D.; Raju, Deepak; Nithin, P.G.; Rajesh, K.F.; Sreekumar, Pradeep

    2013-01-01

    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. PMID:23993010

  9. [A Case of Carotid Free-Floating Thrombus Treated by Carotid Ultrasonography-Guided Endovascular Approach].

    PubMed

    Otawa, Masato; Kinkori, Takeshi; Watanabe, Kenichi; Ando, Ryo; Tambara, Masao; Arima, Toru

    2016-06-01

    We experienced a case of carotid free-floating thrombus treated by carotid ultrasonography-guided endovascular approach. A 63-year-old man was brought to our hospital with the chief complaint of sudden onset left hemiplegia. MRI revealed acute infarction of the right MCA territory due to the right M1 occlusion. Carotid ultrasonography showed a pedunculated, polypoid mobile plaque floating with the cardiac beat. We attempted ultrasonography-guided endovascular treatment. Under proximal balloon protection, the floating plaque was successfully aspirated into the Penumbra aspiration catheter. Carotid stent was also placed to stabilize the residual pedicle of the plaque. Aspirated plaque was identified as fresh thrombus by pathological examination. Carotid ultrasonography-guided endovascular approach was effective for getting the picture of real-time dynamics of the carotid FFT. PMID:27270147

  10. Paraphenylene diamine exacerbates platelet aggregation and thrombus formation in response to a low dose of collagen.

    PubMed

    Zaid, Younes; Marhoume, Fatimazahra; Senhaji, Nezha; Kojok, Kevin; Boufous, Hicham; Naya, Abdallah; Oudghiri, Mounia; Darif, Youssef; Habti, Norddine; Zouine, Soukaina; Mohamed, Fekhaoui; Chait, Abderahmane; Bagri, Abdellah

    2016-02-01

    Paraphenylene daimine (PPD) is an aromatic amine that is widely used in several industrial products; however, its toxicity has been reported in several cases of cardiac arrests. As platelets play a key role in cardiovascular diseases, we aimed to determine the impact of PPD in vitro and in vivo on platelet function. Our findings demonstrated that platelet activation and aggregation were strongly enhanced by PPD. Treatment with PPD primed human platelets that became more reactive in response to low doses of collagen. Furthermore, PPD exacerbated thrombus formation in rats in comparison with those untreated. Our results suggest that PPD is an important platelet primer predisposing platelets to promote thrombus formation in response to vascular injury. This should prompt the authorities to consider controlling the marketing of this product. PMID:26763399

  11. A case of carbon monoxide poisoning with thrombus in the heart: a case report.

    PubMed

    Yildirim, Cuma; Günay, Nurullah; Büyükaslan, Hasan; Küçükdurmaz, Zekeriya; Bozkurt, Selim

    2005-12-15

    Carbon monoxide is a nonirritant, odorless, colorless gas, and is lighter than air. It is an end product of the incomplete combustion of hydrocarbons. Its effects are most prominent in organs sensitive to oxygen deprivation, such as the heart, brain, and kidney. Carbon monoxide poisoning becomes more abundant in winter and at cold places. In Turkey, every year we see several deaths due to poisonous gas leaks from coal or wood stoves. Deaths particularly due to hypoxia-related central nervous system damage and ventricular dysrhythmias are observed. On the other hand, an association between thromboembolic accidents and carbon monoxide poisoning has been shown in literature. Thromboembolic accidents in the mesenteric, central nervous system, and extremities are reported. However, no atrial thrombus has been mentioned. In this study, a case of an atrial thrombus associated with carbon monoxide poisoning following a diagnosis of carbon monoxide poisoning and treatment in the emergency room is reported and the literature is revisited. PMID:16282157

  12. Biomechanical behaviour of cerebral aneurysm and its relation with the formation of intraluminal thrombus: a patient-specific modelling study.

    PubMed

    Wang, Xiaohong; Li, Xiaoyang

    2013-01-01

    Cerebral aneurysm is an irreversible dilatation causing intracranial haemorrhage with severe complications. It is assumed that the biomechanical factor plays a significant role in the development of cerebral aneurysm. However, reports on the correlations between the formation of intraluminal thrombus and the flow pattern, wall shear stress (WSS) distribution of the cerebral aneurysm as well as wall compliance are still limited. In this research, patient-specific numerical simulation was carried out for three cerebral aneurysms based on magnetic resonance imaging (MRI) data-sets. The interaction between pulsatile blood and aneurysm wall was taken into account. The biomechanical behaviour of cerebral aneurysm and its relation with the formation of intraluminal thrombus was studied systematically. The results of the numerical simulation indicated that the region of low blood flow velocity and the region of swirling recirculation were nearly coincident with each other. Besides, there was a significant correlation between the slow swirling flow and the location of thrombus deposition. Excessively low WSS was also found to have strong association with the regions of thrombus formation. Moreover, the relationship between cerebral aneurysm compliance and thrombus deposition was discovered. The patient-specific modelling study based on fluid-structure interaction) may provide a basis for future investigation on the prediction of thrombus formation in cerebral aneurysm. PMID:22292428

  13. [THE THROMBUS FORMATION IN THE PROSTHESIS AS A REACTION OF ORGANISM ON ITS MATERIAL].

    PubMed

    Alekseyeva, T A; Gupalo, Yu M; Kolomoets, A M; Lazarenko, O N; Lazarenko, G O; Litvin, P M; Lohs, I V; Smorzhevskiy, V J; Stepkin, V I

    2016-04-01

    Abstract Vascular prostheses, excised because of their functional properties loss, were studied. Using different methods there was established, that this complication is caused by the thrombus formation as a reaction of organism on the prosthesis material. The testing procedure on compatibility was proposed, using atomic-power microscope. Components of a patient immunity may identify the prosthesis material and start the rejection mechanisms in case of negative reaction. PMID:27434951

  14. No clinical benefit from manual thrombus aspiration in patients with non-ST-elevation myocardial infarction

    PubMed Central

    Dziewierz, Artur; Rakowski, Tomasz; Tokarek, Tomasz; Mielecki, Waldemar; Żabówka, Anna; Plens, Krzysztof; Dudek, Dariusz

    2016-01-01

    Introduction There are scarce data on the usefulness of manual thrombectomy among patients with non-ST-elevation myocardial infarction (NSTEMI). Early positive reports were not supported by the clinical outcome in the recent TATORT-NSTEMI (Thrombus Aspiration in Thrombus Containing Culprit Lesions in Non-ST-Elevation Myocardial Infarction) study. Aim To analyze the long-term outcome of NSTEMI patients treated with manual thrombectomy during percutaneous coronary intervention (PCI) in the Polish multicenter National Registry of Drug Eluting Stents (NRDES) study. Material and methods There were 13 catheterization laboratories in Poland that enrolled patients in NRDES Registry in 2010–2011. Patients with a diagnosis of NSTEMI were divided into two groups: those that were treated with manual thrombectomy for their primary PCI (T) and those who were not (NT). Results There were 923 patients diagnosed with NSTEMI in NRDES. Aspiration thrombectomy was used in 71 (7.7%) patients and the remaining 852 (92.3%) NSTEMI cases were treated without thrombectomy during the index PCI. Thrombectomy was more often used in patients with TIMI less than 1, thrombus grades 4 and 5 and older male patients. Percutaneous coronary interventions complications such as distal embolization and slow flow were more often observed in the thrombectomy subgroup. Overall mortality at 1 year was 1.69% in the T and 5.92% in the NT group (p = 0.24 and p = 0.32 after propensity score matching adjustment with p = 0.11 in the multivariate logistic regression model). Conclusions There was no mortality benefit from thrombus aspiration in NSTEMI patients at 1-year follow-up. PMID:26966447

  15. Percutaneous balloon mitral valvuloplasty with bilateral carotid protection in 2 cases of left atrial thrombus.

    PubMed

    Bansal, N O; Duggal, Bhanu; Omnath, R

    2010-01-01

    We present 2 cases of mitral stenosis with left atrial thrombus who underwent Balloon Mitral Valvotomy with bilateral carotid protection using SpiderFX, distal protection devices to minimize the risk of neuroembolic stroke. One patient was critical MS in congestive heart failure with a highly mobile left atrial appendage clot (LAA) and the second patient was a young female who declined surgery and had an LAA clot which did not respond to warfarin therapy. PMID:21180315

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

    SciTech Connect

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

    1986-09-01

    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 /sup 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 /sup 111/In source implanted at the time of surgery. In five animals, /sup 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 /sup 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 /sup 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, /sup 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.

  17. A Computational Model for Thrombus Formation in Response to Cardiovascular Implantable Devices

    NASA Astrophysics Data System (ADS)

    Horn, John; Ortega, Jason; Maitland, Duncan

    2014-11-01

    Cardiovascular implantable devices elicit complex physiological responses within blood. Notably, alterations in blood flow dynamics and interactions between blood proteins and biomaterial surface chemistry may lead to the formation of thrombus. For some devices, such as stents and heart valves, this is an adverse outcome. For other devices, such as embolic aneurysm treatments, efficient blood clot formation is desired. Thus a method to study how biomedical devices induce thrombosis is paramount to device development and optimization. A multiscale, multiphysics computational model is developed to predict thrombus formation within the vasculature. The model consists of a set of convection-diffusion-reaction partial differential equations for blood protein constituents involved in the progression of the clotting cascades. This model is used to study thrombus production from endovascular devices with the goal of optimizing the device design to generate the desired clotting response. This work was performed in part under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  18. Spinal Cord Infarction Caused by Non-dissected and Unruptured Thoracoabdominal Aortic Aneurysm with Intraluminal Thrombus.

    PubMed

    Ki, Young Jin; Jeon, Byoung Hyun; Bang, Heui Je

    2012-04-01

    Spinal cord infarction, especially anterior spinal artery syndrome, is a relatively rare disease. We report a case of spinal cord infarction caused by thoracoabdominal aortic aneurysm with intraluminal thrombus. A 52-year-old man presented with sudden onset paraplegia. At first, he was diagnosed with cervical myelopathy due to a C6-7 herniated intervertebral disc, and had an operation for C6-7 discetomy and anterior interbody fusion. Approximately 1 month after the operation, he was transferred to the department of rehabilitation in our hospital. Thoracoabdominal aortic aneurysm with intraluminal thrombus was found incidentally on an enhanced computed tomography scan, and high signal intensities were detected at the anterior horns of gray matter from the T8 to cauda equina level on T2-weighted magnetic resonance imaging. There was no evidence of aortic rupture, dissection, or complete occlusion of the aorta. We diagnosed his case as a spinal cord infarction caused by thoracoabdominal aortic aneurysm with intraluminal thrombus. PMID:22639759

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

    SciTech Connect

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

    2008-07-15

    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.

  20. The EP3 Agonist Sulprostone Enhances Platelet Adhesion But Not Thrombus Formation Under Flow Conditions.

    PubMed

    Pasterk, Lisa; Philipose, Sonia; Eller, Kathrin; Marsche, Gunther; Heinemann, Akos; Schuligoi, Rufina

    2015-01-01

    Platelets express the EP2, EP3 and EP4 receptors. Prostaglandin (PG) E2 has a biphasic effect on platelets. Low concentrations of PGE2 enhance platelet aggregation through the activation of the EP3 receptors, while at high concentrations it attenuates aggregation via the EP4 receptor. Consequently, EP3 receptor inhibition was shown to inhibit artherothrombosis, but had no influence on bleeding time in vivo. In this study, we investigated the role of the EP3 receptor in adhesion and thrombus formation under flow conditions in vitro. The EP3 agonist sulprostone caused an increase in the adhesion of washed platelets to fibrinogen as well as to collagen under low shear stress, an effect that was blocked by the EP3 antagonist L-798106. In contrast, when whole blood was perfused over collagen-coated surfaces, sulprostone did not enhance binding and thrombus formation of platelets on collagen; at high concentrations it even attenuated this response. We conclude that in more physiological models of thrombus formation, the role for EP3 receptors is limited, indirectly suggesting that the primary action of PGE2 in haemostasis might be an inhibitory one. PMID:26228833

  1. Automated Delineation of Vessel Wall and Thrombus Boundaries of Abdominal Aortic Aneurysms Using Multispectral MR Images

    PubMed Central

    Rodriguez-Vila, B.; Tarjuelo-Gutierrez, J.; Sánchez-González, P.; Verbrugghe, P.; Fourneau, I.; Maleux, G.; Herijgers, P.; Gomez, E. J.

    2015-01-01

    A correct patient-specific identification of the abdominal aortic aneurysm is useful for both diagnosis and treatment stages, as it locates the disease and represents its geometry. The actual thickness and shape of the arterial wall and the intraluminal thrombus are of great importance when predicting the rupture of the abdominal aortic aneurysms. The authors describe a novel method for delineating both the internal and external contours of the aortic wall, which allows distinguishing between vessel wall and intraluminal thrombus. The method is based on active shape model and texture statistical information. The method was validated with eight MR patient studies. There was high correspondence between automatic and manual measurements for the vessel wall area. Resulting segmented images presented a mean Dice coefficient with respect to manual segmentations of 0.88 and a mean modified Hausdorff distance of 1.14 mm for the internal face and 0.86 and 1.33 mm for the external face of the arterial wall. Preliminary results of the segmentation show high correspondence between automatic and manual measurements for the vessel wall and thrombus areas. However, since the dataset is small the conclusions cannot be generalized. PMID:26236390

  2. Association of Intraluminal Thrombus, Hemodynamic Forces, and Abdominal Aortic Aneurysm Expansion Using Longitudinal CT Images.

    PubMed

    Zambrano, Byron A; Gharahi, Hamidreza; Lim, ChaeYoung; Jaberi, Farhad A; Choi, Jongeun; Lee, Whal; Baek, Seungik

    2016-05-01

    While hemodynamic forces and intraluminal thrombus (ILT) are believed to play important roles on abdominal aortic aneurysm (AAA), it has been suggested that hemodynamic forces and ILT also interact with each other, making it a complex problem. There is, however, a pressing need to understand relationships among three factors: hemodynamics, ILT accumulation, and AAA expansion for AAA prognosis. Hence this study used longitudinal computer tomography scans from 14 patients and analyzed the relationship between them. Hemodynamic forces, represented by wall shear stress (WSS), were obtained from computational fluid dynamics; ILT accumulation was described by ILT thickness distribution changes between consecutives scans, and ILT accumulation and AAA expansion rates were estimated from changes in ILT and AAA volume. Results showed that, while low WSS was observed at regions where ILT accumulated, the rate at which ILT accumulated occurred at the same rate as the aneurysm expansion. Comparison between AAAs with and without thrombus showed that aneurysm with ILT recorded lower values of WSS and higher values of AAA expansion than those without thrombus. Findings suggest that low WSS may promote ILT accumulation and submit the idea that by increasing WSS levels ILT accumulation may be prevented. PMID:26429788

  3. Topical application of a cleanser containing extracts of Diospyros kaki folium, Polygonum cuspidatum and Castanea crenata var. dulcis reduces skin oil content and pore size in human skin

    PubMed Central

    LEE, BO MI; AN, SUNGKWAN; KIM, SOO-YEON; HAN, HYUN JOO; JEONG, YU-JIN; LEE, KYOUNG-ROK; ROH, NAM KYUNG; AHN, KYU JOONG; AN, IN-SOOK; CHA, HWA JUN

    2015-01-01

    The effects of skin pores on skin topographic features can be reduced by decreasing excessive production and accumulation of sebum and elimination of comedones. Therefore, a cosmetic cleanser that regulates sebum homeostasis is required. In the present study, the effects of a cosmetic cleanser that contained Diospyros kaki folium, Polygonum cuspidatum and Castanea crenata var. dulcis (DPC) was examined on the removal of sebum and on skin pore size. Healthy volunteers (n=23) aged 20–50 years were asked to apply the test materials to the face. Skin oil content, pore size, pore number and extracted sebum surface area were measured using various measurement methods. All the measurements were performed at pre- and post-application of the test materials. When the cosmetic cleanser containing DPC was applied to the skin, the oil content decreased by 77.3%, from 6.19 to 1.40. The number of skin pores decreased by 24.83%, from 125.39 to 94.23. Skin pore size decreased from 0.07 to 0.02 µm3 (71.43% decrease). The amount of extracted sebum increased by 335% when the DPC cleanser was used. Compared to the control cleanser, skin oil content was significantly decreased when the cleanser that contained DPC was used. The cleanser containing DPC also decreased pore size and number. Finally, the DPC cleanser easily removed solidified sebum from the skin. PMID:26137233

  4. A Single-Phase Current Source Solar Inverter with Constant Instantaneous Power, Improved Reliability, and Reduced-Size DC-Link Filter

    NASA Astrophysics Data System (ADS)

    Bush, Craig R.

    This dissertation presents a novel current source converter topology that is primarily intended for single-phase photovoltaic (PV) applications. In comparison with the existing PV inverter technology, the salient features of the proposed topology are: a) the low frequency (double of line frequency) ripple that is common to single-phase inverters is greatly reduced; b) the absence of low frequency ripple enables significantly reduced size pass components to achieve necessary DC-link stiffness and c) improved maximum power point tracking (MPPT) performance is readily achieved due to the tightened current ripple even with reduced-size passive components. The proposed topology does not utilize any electrolytic capacitors. Instead an inductor is used as the DC-link filter and reliable AC film capacitors are utilized for the filter and auxiliary capacitor. The proposed topology has a life expectancy on par with PV panels. The proposed modulation technique can be used for any current source inverter where an unbalanced three-phase operation is desires such as active filters and power controllers. The proposed topology is ready for the next phase of microgrid and power system controllers in that it accepts reactive power commands. This work presents the proposed topology and its working principle supported by with numerical verifications and hardware results. Conclusions and future work are also presented.

  5. A Dominant Negative Mutant of Cyclin-Dependent Kinase A Reduces Endoreduplication but Not Cell Size or Gene Expression in Maize Endosperm

    PubMed Central

    Leiva-Neto, João T.; Grafi, Gideon; Sabelli, Paolo A.; Dante, Ricardo A.; Woo, Young-min; Maddock, Sheila; Gordon-Kamm, William J.; Larkins, Brian A.

    2004-01-01

    Cells in maize (Zea mays) endosperm undergo multiple cycles of endoreduplication, with some attaining DNA contents as high as 96C and 192C. Genome amplification begins around 10 d after pollination, coincident with cell enlargement and the onset of starch and storage protein accumulation. Although the role of endoreduplication is unclear, it is thought to provide a mechanism that increases cell size and enhances gene expression. To investigate this process, we reduced endoreduplication in transgenic maize endosperm by ectopically expressing a gene encoding a dominant negative mutant form of cyclin-dependent kinase A. This gene was regulated by the 27-kD γ-zein promoter, which restricted synthesis of the defective enzyme to the endoreduplication rather than the mitotic phase of endosperm development. Overexpression of a wild-type cyclin-dependent kinase A increased enzyme activity but had no effect on endoreduplication. By contrast, ectopic expression of the defective enzyme lowered kinase activity and reduced by half the mean C-value and total DNA content of endosperm nuclei. The lower level of endoreduplication did not affect cell size and only slightly reduced starch and storage protein accumulation. There was little difference in the level of endosperm gene expression with high and low levels of endoreduplication, suggesting that this process may not enhance transcription of genes associated with starch and storage protein synthesis. PMID:15208390

  6. 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.

    PubMed

    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. PMID:25827179

  7. Enhanced Effect of Human Cardiac Stem Cells and Bone Marrow Mesenchymal Stem Cells to Reduce Infarct Size and Restore Cardiac Function after Myocardial Infarction

    PubMed Central

    Williams, Adam R.; Hatzistergos, Konstantinos E.; Addicott, Benjamin; McCall, Fred; Carvalho, Decio; Suncion, Viky; Morales, Azorides R.; Silva, Jose Da; Sussman, Mark A.; Heldman, Alan W.; Hare, Joshua M.

    2013-01-01

    Background As mesenchymal stem cells (MSCs) induce proliferation and differentiation of c-kit+ cardiac stem cells (CSCs) in vivo and in vitro, we hypothesized that combining human (h)MSCs with c-kit+ hCSCs produces greater infarct size reduction compared to either cell administered alone after MI. Methods and Results Yorkshire swine underwent balloon occlusion of the LAD coronary artery followed by reperfusion, and were immunosuppressed after MI with cyclosporine and methylprednisolone. Intramyocardial injection of either: combination hCSCs/hMSCs (1M/200M, n=5), hCSCs alone (1M, n=5), hMSCs alone (200M, n=5), or placebo (PBS, n=5) was administered to the infarct border zones at 14 days post-MI. Phenotypic response to cell therapy was assessed by cardiac MRI and micromanometer conductance catheterization hemodynamics. While each cell therapy group had reduced MI size relative to placebo (p<0.05), the MI size reduction was 2-fold greater in combination vs. either cell therapy alone (p<0.05). Accompanying enhanced MI size reduction was substantial improvement in LV chamber compliance (end-diastolic pressure volume relationship, p<0.01) and contractility (preload recruitable stroke work and dP/dtmax, p<0.05) in combination treated swine. EF was restored to baseline in cell treated pigs, while placebo pigs had persistently depressed LV function (p<0.05). Immunohistochemistry showed 7-fold enhanced engraftment of stem cells in the combination therapy group vs. either cell type alone (P<0.001). Conclusions Combining hMSCs and hCSCs as a cell therapeutic enhances scar size reduction, and restores diastolic and systolic function toward normal after MI. Taken together these findings illustrate important biological interactions between c-kit+ CSCs and MSCs that enhance cell-based therapeutic responses. PMID:23224061

  8. Facilitating roles of murine platelet glycoprotein Ib and αIIbβ3 in phosphatidylserine exposure during vWF–collagen-induced thrombus formation

    PubMed Central

    Kuijpers, Marijke J E; Schulte, Valerie; Oury, Cécile; Lindhout, Theo; Broers, Jos; Hoylaerts, Marc F; Nieswandt, Bernhard; Heemskerk, Johan W M

    2004-01-01

    Vessel wall damage exposes collagen fibres, to which platelets adhere directly via the collagen receptors glycoprotein (GP) VI and integrin α2β1 and indirectly by collagen-bound von Willebrand factor (vWF) via the GPIb-V-IX and integrin αIIbβ3 receptor complexes. Platelet–collagen interaction under shear stimulates thrombus formation in two ways, by integrin-dependent formation of platelet aggregates and by surface exposure of procoagulant phosphatidylserine (PS). GPVI is involved in both processes, complemented by α2β1. In mouse blood flowing over collagen, we investigated the additional role of platelet–vWF binding via GPIb and αIIbβ3. Inhibition of GPIb as well as blocking of vWF binding to collagen reduced stable platelet adhesion at high shear rate. This was accompanied by delayed platelet Ca2+ responses and reduced PS exposure, while microaggregates were still formed. Inhibition of integrin αIIbβ3 with JON/A antibody, which blocks αIIbβ3 binding to both vWF and fibrinogen, reduced PS exposure and aggregate formation. The JON/A effects were not enhanced by combined blocking of GPIb–vWF binding, suggesting a function for αIIbβ3 downstream of GPIb. Typically, with blood from FcR γ-chain +/− mutant mice, expressing 50% of normal platelet GPVI levels, GPIb blockage almost completely abolished platelet adhesion and PS exposure. Together, these data indicate that, under physiological conditions of flow, both adhesive receptors GPIb and αIIbβ3 facilitate GPVI-mediated PS exposure by stabilizing platelet binding to collagen. Hence, these glycoproteins have an assistant procoagulant role in collagen-dependent thrombus formation, which is most prominent at reduced GPVI activity and is independent of the presence of thrombin. PMID:15155790

  9. Long term follow up of patients with anterior myocardial infarction complicated by left ventricular thrombus in the thrombolytic era.

    PubMed Central

    Mooe, T.; Teien, D.; Karp, K.; Eriksson, P.

    1996-01-01

    OBJECTIVES: To examine the appearance and resolution of left ventricular thrombi and to study the relation between thrombus and mortality during long term follow up after anterior myocardial infarction. DESIGN: Ninety nine consecutive patients were prospectively studied until the last included patient had been followed for one year. Streptokinase and aspirin were used routinely, anticoagulants only after a decision by the attending physician. Echocardiography was performed within 3 d of admission, before discharge, and after one, three, and 12 months. SETTING: Umeå University Hospital, a teaching hospital in Northern Sweden. MAIN OUTCOME MEASURES: Left ventricular thrombus, segmental myocardial function, and mortality during follow up. RESULTS: Thirty patients (30%) had a thrombus on discharge. One month, three months, and 12 months after hospital discharge, the thrombus had resolved in 81%, 84%, and 90% of the patients, respectively. The proportion of resolved thrombi at one month was high irrespective of whether anticoagulants were given (10/11, 91%) or not (12/16, 75%), P = 0.4. New thrombi appeared in 12 patients after discharge and resolution and reapperance of thrombi continued during the follow up period. Patients who developed a thrombus during the hospital stay (n = 44, 44%) had more extensive myocardial dysfunction on discharge (P < 0.001) and significantly higher mortality during the follow up period than those without a thrombus (23% v 7%, P < 0.01). CONCLUSIONS: With routine thrombolytic and aspirin treatment of anterior myocardial infarction, left ventricular thrombi usually resolve during the first month after hospital discharge. Appearance and resolution of thrombi continue, however, in a significant proportion of the patients during long term follow up. A left ventricular thrombus during the initial hospital stay is associated with high long term mortality. PMID:8800987

  10. Combination of Superselective Arterial Embolization and Radiofrequency Ablation for the Treatment of a Giant Renal Angiomyolipoma Complicated with Caval Thrombus

    PubMed Central

    Stamatiou, Konstantinos N.; Moschouris, Hippocrates; Marmaridou, Kiriaki; Kiltenis, Michail; Kladis-Kalentzis, Konstantinos; Malagari, Katerina

    2016-01-01

    This is a case of a 78-year-old male patient with multiple angiomyolipomas of a solitary right kidney. The largest of these tumors (maximum diameter: 13.4 cm) caused significant extrinsic compression of the inferior vena cava complicated by thrombosis of this vessel. Treatment of thrombosis with anticoagulants had been ineffective and the patient had experienced a bleeding episode from the largest right renal angiomyolipoma, which had been treated by transarterial embolization in another institution, 4 months prior to our intervention. Our approach included superselective transarterial embolization of the dominant, right kidney angiomyolipoma with hydrogel microspheres, which was combined, 20 days later, with ultrasonographically guided radiofrequency ablation. Both interventions were uneventful. Computed tomography 2 months after ablation showed a 53% reduction in tumor volume, reduced space-occupying effect on inferior vena cava, and resolution of caval thrombus. Nine months after intervention the patient has had no recurrence of thrombosis or hemorrhage and no tumor regrowth has been observed. The combination of superselective transarterial embolization and radiofrequency ablation seems to be a feasible, safe, and efficient treatment of large renal angiomyolipomas. PMID:27293932

  11. Combination of Superselective Arterial Embolization and Radiofrequency Ablation for the Treatment of a Giant Renal Angiomyolipoma Complicated with Caval Thrombus.

    PubMed

    Stamatiou, Konstantinos N; Moschouris, Hippocrates; Marmaridou, Kiriaki; Kiltenis, Michail; Kladis-Kalentzis, Konstantinos; Malagari, Katerina

    2016-01-01

    This is a case of a 78-year-old male patient with multiple angiomyolipomas of a solitary right kidney. The largest of these tumors (maximum diameter: 13.4 cm) caused significant extrinsic compression of the inferior vena cava complicated by thrombosis of this vessel. Treatment of thrombosis with anticoagulants had been ineffective and the patient had experienced a bleeding episode from the largest right renal angiomyolipoma, which had been treated by transarterial embolization in another institution, 4 months prior to our intervention. Our approach included superselective transarterial embolization of the dominant, right kidney angiomyolipoma with hydrogel microspheres, which was combined, 20 days later, with ultrasonographically guided radiofrequency ablation. Both interventions were uneventful. Computed tomography 2 months after ablation showed a 53% reduction in tumor volume, reduced space-occupying effect on inferior vena cava, and resolution of caval thrombus. Nine months after intervention the patient has had no recurrence of thrombosis or hemorrhage and no tumor regrowth has been observed. The combination of superselective transarterial embolization and radiofrequency ablation seems to be a feasible, safe, and efficient treatment of large renal angiomyolipomas. PMID:27293932

  12. 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.

    PubMed

    Tennuci, Christopher; Pearce, Gillian; Wong, Julian; Nayak, Sanjeev; Jones, Tom; Lally, Frank; Roffe, Christine

    2011-01-01

    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. PMID:21603169

  13. 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

    PubMed Central

    Tennuci, Christopher; Pearce, Gillian; Wong, Julian; Nayak, Sanjeev; Jones, Tom; Lally, Frank; Roffe, Christine

    2011-01-01

    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. PMID:21603169

  14. DNA double-strand breaks induce the expression of flavin-containing monooxygenase and reduce root meristem size in Arabidopsis thaliana.

    PubMed

    Chen, Poyu; Umeda, Masaaki

    2015-08-01

    Plants use various mechanisms to cope with environmental stresses, which often threaten genome integrity. In Arabidopsis, DNA double-strand breaks (DSBs) reduce root meristem size in a SOG1-dependent manner. SOG1 is a key transcription factor controlling the response to DNA damage. However, the underlying mechanism remains largely unknown. In this study, we found that treatment with the DSB inducer zeocin increased the accumulation of H2O2 in root tips. Chromatin immunoprecipitation analysis showed that SOG1 directly binds to the promoter of FMO1, which encodes a flavin-containing monooxygenase and is associated with the production of reactive oxygen species (ROS), H2O2 in particular. Indeed, zeocin induced the expression of FMO1 in a SOG1-dependent manner, and neither the sog1 nor the fmo1 knockout mutant exhibited higher H2O2 accumulation in root tips. Consequently, both sog1 and fmo1 could tolerate exposure to zeocin, in terms of root growth and the maintenance of the meristem size. However, transgenic plants over-expressing FMO1 also accumulated H2O2 in response to zeocin exposure, suggesting that other ROS-synthesis genes are also involved in the regulation of ROS production. We conclude that SOG1-mediated regulation of ROS homeostasis plays a key role in the reduction of root meristem size under DNA stress conditions. PMID:26033196

  15. In vivo transfer of soluble TNF-alpha receptor 1 gene improves cardiac function and reduces infarct size after myocardial infarction in rats.

    PubMed

    Sugano, Masahiro; Tsuchida, Keiko; Hata, Tomoji; Makino, Naoki

    2004-05-01

    Increased circulating and cardiac TNF-alpha levels during myocardial ischemia have been found in both experimental animals and patients with ischemic heart disease and advanced heart failure. Soluble TNF-alpha receptor 1 (sTNFR1) is an antagonist to TNF-alpha. In the present study, we examined whether sTNFR1 improves cardiac function in rats after myocardial infarction. Male Wistar rats were subjected to left coronary artery (LCA) ligation. Immediately after the ligation, a total of 200 microg of either the sTNFR1 or LacZ plasmid was injected into three different sites in the left ventricular wall. From 1 to 21 days after LCA ligation, TNF-alpha bioactivity in the heart was higher in rats receiving LacZ plasmid than in sham-operated rats, whereas sTNFR1 plasmid significantly suppressed the increase. The LV diastolic dimension was significantly lower, and the fractional shortening was significantly higher in rats treated with the sTNFR1 plasmid than in those treated with the LacZ plasmid. At 21 days after LCA ligation, the LV end-diastolic pressure was also significantly lower in the rats treated with the sTNFR1 plasmid. In addition, the sTNFR1 expression plasmid had significantly reduced the infarct size. In conclusion, TNF-alpha bioactivity in the heart increased during the early stage of infarction and remained elevated. This elevation seemed partially responsible for the impairment of LV function and the increased infarct size. Suppression of TNF-alpha bioactivity from the early stage of infarction with the sTNFR1 plasmid improved cardiac function and reduced infarct size. PMID:15117889

  16. Synergistic prognostic values of cardiac sympathetic innervation with left ventricular hypertrophy and left atrial size in heart failure patients without reduced left ventricular ejection fraction: a cohort study

    PubMed Central

    Doi, Takahiro; Nakata, Tomoaki; Hashimoto, Akiyoshi; Yuda, Satoshi; Wakabayashi, Takeru; Kouzu, Hidemichi; Kaneko, Naofumi; Hase, Mamoru; Tsuchihashi, Kazufumi; Miura, Tetsuji

    2012-01-01

    Objectives This study tested whether cardiac sympathetic innervation assessed by metaiodobenzylguanidine (MIBG) activity has long-term prognostic value in combination with left ventricular hypertrophy (LVH) and left atrial size in heart failure (HF) patients without reduced left ventricular ejection fraction (LVEF). Design A single-centre prospective cohort study. Setting/participants With primary endpoints of cardiac death and rehospitalisation due to HF progression, 178 consecutive symptomatic HF patients with 74% men, mean age of 56 years and mean LVEF of 64.5% were followed up for 80 months. The entry criteria consisted of LVEF more than 50%, completion of predischarge clinical evaluations including cardiac MIBG and echocardiographic studies and at least more than 1-year follow-up when survived. Results Thirty-four patients with cardiac evens had larger left atrial dimension (LAD), increased LV mass index, reduced MIBG activity quantified as heart-to-mediastinum ratio (HMR) than did the others. Multivariable Cox analysis showed that LAD and HMR were significant predictors (HR of 1.080 (95% CI 1.00 to 1.16, p=0.044) and 0.107 (95% CI 0.01 to 0.61, p=0.012, respectively). Thresholds of HMR (1.65) and LAD (37 mm) were closely related to identification of high-risk patients. In particular, HMR was a significant determinant of cardiac events in both patients with and without LV hypertrophy. Reduced HMR with enlarged LAD or LV hypertrophy identified patients at most increased risk; overall log-rank value, 11.5, p=0.0032 for LAD and 17.5, p=0.0002, respectively. Conclusions In HF patients without reduced LV ejection fraction, impairment of cardiac sympathetic innervation is related to cardiac outcomes independently and synergistically with LA size and LV hypertrophy. Cardiac sympathetic innervation assessment can contribute to better risk-stratification in combination with evaluation of LA size and LV mass but is needed to be evaluated for establishing aetiology

  17. Therapy with Recombinant T-cell Receptor Ligand reduces infarct size and infiltrating inflammatory cells in brain after middle cerebral artery occlusion in mice

    PubMed Central

    Dziennis, Suzan; Mader, Sarah; Akiyoshi, Kozaburo; Ren, Xuefang; Ayala, Patricia; Burrows, Gregory G.; Vandenbark, Arthur A.; Herson, Paco S.; Hurn, Patricia D.; Offner, Halina

    2011-01-01

    Stroke induces a biphasic effect on the peripheral immune response that involves early activation of peripheral leukocytes followed by severe immunosuppression and atrophy of the spleen. Peripheral immune cells, including T lymphocytes, migrate to the brain and exacerbate the developing infarct. Recombinant T-cell receptor (TCR) Ligand (RTL)551 is designed as a partial TCR agonist for myelin oligodendrocyte glycoprotein (MOG)-reactive T cells and has demonstrated the capacity to limit infarct volume and inflammation in brain when administered to mice undergoing middle cerebral artery occlusion (MCAO). The goal of this study was to determine if RTL551 could retain protection when given within the therapeutically relevant 4h time window currently in clinical practice for stroke patients. RTL551 was administered subcutaneously 4h after MCAO, with repeated doses every 24h until the time of euthanasia. Cell numbers were assessed in the brain, blood, spleen and lymph nodes and infarct size was measured after 24 and 96h reperfusion. RTL551 reduced infarct size in both cortex and striatum at 24h and in cortex at 96h after MCAO and inhibited the accumulation of inflammatory cells in brain at both time points. At 24h post-MCAO, RTL551 reduced the frequency of the activation marker, CD44, on T-cells in blood and in the ischemic hemisphere. Moreover, RTL551 reduced expression of the chemokine receptors, CCR5 in lymph nodes and spleen, and CCR7 in the blood and lymph nodes. These data demonstrate effective treatment of experimental stroke with RTL551 within a therapeutically relevant 4h time window through immune regulation of myelin-reactive inflammatory T-cells. PMID:21472429

  18. Inferior vena cava tumor thrombus that directly infiltrated from paracaval lymph node metastases in a patient with recurrent hepatocellular carcinoma

    PubMed Central

    2013-01-01

    Herein, we present the case of a patient with recurrent hepatocellular carcinoma (HCC) who had paracaval lymph node (LN) metastases with an inferior vena cava (IVC) tumor thrombus after a hepatectomy. A 65-year-old man with chronic hepatitis B virus infection received an extended anterior segmentectomy because of two hepatic tumors, located in segments 7 and 8. Histological examination of both resected specimens showed mostly moderately differentiated HCC with some poorly differentiated areas, and liver cirrhosis (A2/F4). Because the patient had an elevated α-fetoprotein serum level, abdominal computed tomography (CT) was performed. Abdominal CT revealed a 9-mm-diameter recurrent tumor in hepatic segment 3 and paracaval LN metastases with an IVC tumor thrombus at 8 months after the first operation. The patient received transcatheter arterial chemoembolization as treatment for the intrahepatic recurrence, following resection of the paracaval LN metastases and removal of the IVC tumor thrombus. In this case, the paracaval LN metastases had directly infiltrated the IVC via the lumbar veins, resulting in an IVC tumor thrombus, which usually develops from an intrahepatic tumor via the hepatic vein. The development of an IVC tumor thrombus with HCC recurrence, as in this case, is very rare, and based on a PubMed search, we believe this report may be the first to describe this condition. PMID:23915104

  19. Hepatocellular Carcinoma With Tumor Thrombus Occupying the Right Atrium and Portal Vein: A Case Report and Literature Review.

    PubMed

    Luo, Xin; Zhang, Binhao; Dong, Shuilin; Zhang, Bixiang; Chen, Xiaoping

    2015-08-01

    Hepatocellular carcinoma (HCC) patients with tumor thrombus extended through the major hepatic veins and inferior vena cava into the right atrium (RA) are rare, and most cases are considered as the advanced stage with a poor prognosis.We report a case of HCC with a tumor thrombus extending into the RA and a tumor thrombus in the portal vein. A literature search for case reports was performed on PubMed.Compared with the published literature, our case is one of the youngest patients, but with the most advanced HCC that invades both the hepatic inflow and outflow vasculature. For this patient, we resected the tumor thrombus in the RA with the use of cardiopulmonary bypass, and then removed the tumor thrombus in the portal vein and ligated the left branch of portal vein. Because of insufficient remnant liver volume, microwave ablation and transcatheter arterial chemoembolization were performed to control the growth of HCC. The patient survived 6 months after surgery.This case suggests that for patients with extension of HCC into the RA and portal vein, surgery is a useful therapeutic modality, even in case that liver tumor cannot be resected. PMID:26313767

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

    PubMed Central

    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

  1. Role of Leukocyte Elastase in Preventing Cellular Re-Colonization of the Mural Thrombus

    PubMed Central

    Fontaine, Vincent; Touat, Ziad; Mtairag, El Mostafa; Vranckx, Roger; Louedec, Liliane; Houard, Xavier; Andreassian, Bernard; Sebbag, Uriel; Palombi, Tonino; Jacob, Marie-Paule; Meilhac, Olivier; Michel, Jean-Baptiste

    2004-01-01

    To explore possible mechanisms responsible for the absence of cell re-colonization of mural thrombi in aneurysms, we analyzed the release and storage of leukocyte proteases in the most luminal layer versus intermediate and abluminal layers of 10 mural thrombi of human abdominal aortic aneurysms. The luminal layer contained many polymorphonuclear leukocytes (PMNs), which released pro-matrix metalloproteinase (MMP)-9 and MMP-8. Leukocyte elastase was also stored and released by the luminal layer (immunohistochemistry, activity on synthetic substrates, and casein zymography). Acid buffer allowed extraction of leukocyte elastase from the luminal layer, which was inhibited by elastase inhibitors. Casein zymography of luminal extracts and conditioned medium from formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMNs exhibited a similar lysis pattern, corresponding to elastase activity. Smooth muscle cell (SMC) seeding resulted in colonization of the intermediate thrombus layer ex vivo but not of the luminal layer. Extracts of the luminal layer induced loss of anchorage of both cultured human smooth muscle cells and stromal cells of bone marrow origin (anoikis). This anoikis was prevented by preincubation of the extracts with serine protease inhibitors. Moreover, adhesion of human SMCs and stromal bone marrow cells on fibrin gels was strongly inhibited when the gel was preincubated with pure elastase, medium of fMLP-stimulated PMNs, or extracts of luminal layers of mural thrombi. This loss of cell anchorage was prevented by the preincubation of the medium or extracts with α1-antitrypsin, but not when α1-antitrypsin was added after binding of elastase to the fibrin gel. In conclusion, elastase released by PMNs trapped within the mural thrombus impairs the spontaneous anchorage of mesenchymal cells to a fibrin matrix. This phenomenon could be one mechanism by which cellular healing of the mural thrombus in aneurysms is prevented. PMID:15161642

  2. Vascular wall hypoxia promotes arterial thrombus formation via augmentation of vascular thrombogenicity.

    PubMed

    Matsuura, Yunosuke; Yamashita, Atsushi; Iwakiri, Takashi; Sugita, Chihiro; Okuyama, Nozomi; Kitamura, Kazuo; Asada, Yujiro

    2015-07-01

    Atherosclerotic lesions represent a hypoxic milieu. However, the significance of this milieu in atherothrombosis has not been established. We aimed to assess the hypothesis that vascular wall hypoxia promotes arterial thrombus formation. We examined the relation between vascular wall hypoxia and arterial thrombus formation using a rabbit model in which arterial thrombosis was induced by 0.5 %-cholesterol diet and repeated balloon injury of femoral arteries. Vascular wall hypoxia was immunohistochemically detected by pimonidazole hydrochloride, a hypoxia marker. Rabbit neointima and THP-1 macrophages were cultured to analyse prothrombotic factor expression under hypoxic conditions (1 % O2). Prothrombotic factor expression and nuclear localisation of hypoxia-inducible factor (HIF)-1α and nuclear factor-kappa B (NF-κB) p65 were immunohistochemically assessed using human coronary atherectomy plaques. Hypoxic areas were localised in the macrophage-rich deep portion of rabbit neointima and positively correlated with the number of nuclei immunopositive for HIF-1α and NF-κB p65, and tissue factor (TF) expression. Immunopositive areas for glycoprotein IIb/IIIa and fibrin in thrombi were significantly correlated with hypoxic areas in arteries. TF and plasminogen activator inhibitor-1 (PAI-1) expression was increased in neointimal tissues and/or macrophages cultured under hypoxia, and both were suppressed by inhibitors of either HIF-1 or NF-κB. In human coronary plaques, the number of HIF-1α-immunopositive nuclei was positively correlated with that of NF-κB-immunopositive nuclei and TF-immunopositive and PAI-1-immunopositive area, and it was significantly higher in thrombotic plaques. Vascular wall hypoxia augments the thrombogenic potential of atherosclerotic plaque and thrombus formation on plaques via prothrombotic factor upregulation. PMID:25833755

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

    SciTech Connect

    Turmel-Rodrigues, Luc A E-mail: cim.stgatien@wanadoo.fr

    2005-01-15

    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.

  4. Right atrial thrombus associated with subclavian catheter developed due to total parenteral nutrition application

    PubMed Central

    Sahin, Nursel; Basarici, Ibrahim; Erbasan, Ozan

    2016-01-01

    Central venous catheterization as a frequent routine clinical procedure may have significant complications. Mechanical complications may occur during catheter placement, whereas thromboembolic and infectious complications can be seen during follow-up. Total parenteral nutrition (TPN) associated central venous catheterizations may result in early mechanical complications and thrombotic and infectious complications in the long term. This paper describes a patient diagnosed as mitochondrial neurogastrointestinal encephalomyopathy requiring long-term central venous catheterization for TPN implementation, who had an infected thrombus on the catheter tip resected by cardiac surgery. PMID:27212985

  5. Thrombus entrapped by patent foramen ovale in a patient with pulmonary embolism: a case report

    PubMed Central

    Nam, Sang Beom; Kim, Chan Mi; Cho, Sung-Ah; Chung, Sungchan

    2015-01-01

    Thrombus-in-transit appears to increase the risk of mortality compared to pulmonary embolism alone and can require alteration in therapeutic plan. We present the case of a biatrial thromboembolus caught in transit across a patent foramen ovale diagnosed by intraoperative transesophageal echocardiogram in a 69-year-old female with acute pulmonary embolism and subsequent acute cerebral infarction. We suggest that echocardiography should be performed in a patient with suspected pulmonary thromboembolism to evaluate right heart function and diagnose emboli in transit. PMID:25664158

  6. Immunohistological assessment of fibrin deposition and thrombus formation in canine mammary neoplasia.

    PubMed

    Golombiewski, A; Gutberlet, K; Rudolph, R

    1997-08-01

    A commercially available monoclonal antibody against human fibrin was used to detect fibrin in canine formalin-fixed, paraffin wax-embedded tissue by applying a slightly modified alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. Twenty-eight mammary tumours from six bitches were examined for the presence of fibrin. Thrombi and extravascular fibrin deposits were detected in 15 tumours (12 complex adenocarcinomas, one adenocarcinoma, two solid carcinomas), and a single thrombus was detected in one adenoma; 12 tumours (three adenomas, one complex adenoma, four complex adenocarcinomas and four adenocarcinomas) did not show any staining reaction. PMID:9352443

  7. Residual Inferior Vena Cava Thrombus Detected by Transesophageal Echocardiography After Resection of a Malignant Adrenal Mass.

    PubMed

    Burbano, Nelson H; Vlah, Claudene; Argalious, Maged

    2015-10-15

    A 43-year-old woman with a history of the Cushing syndrome secondary to adrenocortical carcinoma presented to the operating room for right adrenalectomy, hepatectomy, nephrectomy, and inferior vena cava (IVC) thrombectomy. Initial intraoperative transesophageal echocardiogram (TEE) confirmed the presence of an IVC tumor below the hepatic veins. Total vascular exclusion of the liver was necessary to perform the operation. A repeat TEE showed a residual thrombus within the IVC prompting an additional cavotomy to successfully remove the entire mass. The remainder of the procedure finalized uneventfully. The case highlights the importance of TEE monitoring for noncardiac surgery with thrombotic involvement of the IVC. PMID:26466307

  8. A Collision Probability Model of Portal Vein Tumor Thrombus Formation in Hepatocellular Carcinoma

    PubMed Central

    Xiong, Fei

    2015-01-01

    Hepatocellular carcinoma is one of the most common malignancies worldwide, with a high risk of portal vein tumor thrombus (PVTT). Some promising results have been achieved for venous metastases of hepatocellular carcinoma; however, the etiology of PVTT is largely unknown, and it is unclear why the incidence of PVTT is not proportional to its distance from the carcinoma. We attempted to address this issue using physical concepts and mathematical tools. Finally, we discuss the relationship between the probability of a collision event and the microenvironment of the PVTT. Our formulae suggest that the collision probability can alter the tumor microenvironment by increasing the number of tumor cells. PMID:26131562

  9. Resolution of a warfarin and dabigatran-resistant left atrial appendage thrombus with apixaban.

    PubMed

    Miwa, Yosuke; Minamishima, Toshinori; Sato, Toshiaki; Sakata, Konomi; Yoshino, Hideaki; Soejima, Kyoko

    2016-06-01

    The majority of embolisms associated with atrial fibrillation (AF) are from the left atrial appendage (LAA). To treat the existing thrombus, warfarin and novel anticoagulants have been used. However, there has been no clinical information regarding the difference of the effects of congealing the fibrinogenolysis system among these oral anticoagulants. Here, we report a case of persistent AF, in whom apixaban, factor Xa inhibitor resolved an LAA clot refractory to warfarin and direct thrombin inhibition. Factor Xa inhibitor, apixaban, could resolve the left appendage thrombosis refractory to warfarin and dabigatran. PMID:27354873

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

    SciTech Connect

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

    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

  11. A persistent sciatic artery aneurysm containing a free-floating thrombus: report of a case.

    PubMed

    Unosawa, Satoshi; Ishii, Yusuke; Niino, Tetsuya

    2015-08-01

    A persistent sciatic artery is a rare vascular anomaly in which the sciatic artery, which involutes in the embryonic stage, persists as the blood supply to the lower limb. This vascular anomaly is often associated with aneurysm formation. A persistent sciatic artery aneurysm is a rare cause of peripheral arterial embolic disease. We herein describe the case of a 72-year-old female with a free-floating thrombus in a persistent sciatic artery aneurysm. She underwent iliac-popliteal artery bypass and exclusion of the aneurysm to prevent an embolic event. PMID:25016369

  12. Potential Activity, Size, and Structure of Sulfate-Reducing Microbial Communities in an Exposed, Grazed and a Sheltered, Non-Grazed Mangrove Stand at the Red Sea Coast

    PubMed Central

    Balk, Melike; Keuskamp, Joost A.; Laanbroek, Hendrikus J.

    2015-01-01

    After oxygen, sulfate is the most important oxidant for the oxidation of organic matter in mangrove forest soils. As sulfate reducers are poor competitors for common electron donors, their relative success depends mostly on the surplus of carbon that is left by aerobic organisms due to oxygen depletion. We therefore hypothesized that sulfate-cycling in mangrove soils is influenced by the size of net primary production, and hence negatively affected by mangrove degradation and exploitation, as well as by carbon-exporting waves. To test this, we compared quantitative and qualitative traits of sulfate-reducing communities in two Saudi-Arabian mangrove stands near Jeddah, where co-occurring differences in camel-grazing pressure and tidal exposure led to a markedly different stand height and hence primary production. Potential sulfate reduction rates measured in anoxic flow-through reactors in the absence and presence of additional carbon sources were significantly higher in the samples from the non-grazed site. Near the surface (0–2 cm depth), numbers of dsrB gene copies and culturable cells also tended to be higher in the non-grazed sites, while these differences were not detected in the sub-surface (4–6 cm depth). It was concluded that sulfate-reducing microbes at the surface were indeed repressed at the low-productive site as could be expected from our hypothesis. At both sites, sulfate reduction rates as well as numbers of the dsrB gene copies and viable cells increased with depth suggesting repression of sulfate reduction near the surface in both irrespective of production level. Additionally, sequence analysis of DNA bands obtained from DGGE gels based on the dsrB gene, showed a clear difference in dominance of sulfate-reducing genera belonging to the Deltaproteobacteria and the Firmicutes between sampling sites and depths. PMID:26733999

  13. Potential Activity, Size, and Structure of Sulfate-Reducing Microbial Communities in an Exposed, Grazed and a Sheltered, Non-Grazed Mangrove Stand at the Red Sea Coast.

    PubMed

    Balk, Melike; Keuskamp, Joost A; Laanbroek, Hendrikus J

    2015-01-01

    After oxygen, sulfate is the most important oxidant for the oxidation of organic matter in mangrove forest soils. As sulfate reducers are poor competitors for common electron donors, their relative success depends mostly on the surplus of carbon that is left by aerobic organisms due to oxygen depletion. We therefore hypothesized that sulfate-cycling in mangrove soils is influenced by the size of net primary production, and hence negatively affected by mangrove degradation and exploitation, as well as by carbon-exporting waves. To test this, we compared quantitative and qualitative traits of sulfate-reducing communities in two Saudi-Arabian mangrove stands near Jeddah, where co-occurring differences in camel-grazing pressure and tidal exposure led to a markedly different stand height and hence primary production. Potential sulfate reduction rates measured in anoxic flow-through reactors in the absence and presence of additional carbon sources were significantly higher in the samples from the non-grazed site. Near the surface (0-2 cm depth), numbers of dsrB gene copies and culturable cells also tended to be higher in the non-grazed sites, while these differences were not detected in the sub-surface (4-6 cm depth). It was concluded that sulfate-reducing microbes at the surface were indeed repressed at the low-productive site as could be expected from our hypothesis. At both sites, sulfate reduction rates as well as numbers of the dsrB gene copies and viable cells increased with depth suggesting repression of sulfate reduction near the surface in both irrespective of production level. Additionally, sequence analysis of DNA bands obtained from DGGE gels based on the dsrB gene, showed a clear difference in dominance of sulfate-reducing genera belonging to the Deltaproteobacteria and the Firmicutes between sampling sites and depths. PMID:26733999

  14. Acute Left Arm Ischemia Associated with Floating Thrombus in the Proximal Descending Aorta: Combined Endovascular and Surgical Therapy

    SciTech Connect

    Fanelli, F.; Gazzetti, M.; Boatta, E.; Ruggiero, M.; Lucatelli, P.; Speziale, F.

    2011-02-15

    Free floating thrombus in the proximal descending aorta is an uncommon and dangerous condition that can be associated with acute peripheral embolization. The few cases described were solved with surgical and/or medical therapy. We report the case of a patient with acute left arm ischemia secondary to the presence of floating thrombus in the proximal descending aorta extending into the left subclavian artery, solved with combined endovascular and surgical therapy. Treatment was successfully performed with thrombembolectomy combined with temporary deployment, into the descending aorta, of a Wallstent in a 'basket-fashion' to avoid distal embolization secondary to thrombus fragmentation. At 1 year follow-up the patient remained symptom-free.

  15. A woman with cystic fibrosis, severe hypoxaemia, an atrial thrombus and a patent foramen ovale: a case report

    PubMed Central

    2009-01-01

    Introduction Cystic fibrosis is usually associated with chronic pulmonary sepsis and frequent infective exacerbations. We report a very unusual cause of severe hypoxaemia in a woman with cystic fibrosis caused by thrombus formation in the right atrium. Case presentation A 21-year-old Caucasian woman with cystic fibrosis and a totally implantable venous access device presented with severe hypoxaemia. This was initially treated with antibiotics but her oxygen levels did not improve significantly. Subsequently, a transient ischaemic attack occurred. Further investigations, including a contrast echocardiogram and a cardiac magnetic resonance scan, revealed the presence of a large right atrial thrombus and right-to-left intracardiac shunt through a patent foramen ovale. Conclusion This case highlights the need to consider a right-to-left shunt in chronic respiratory diseases when hypoxaemia is out of proportion to the degree of lung function impairment. Totally implantable venous access devices should always be considered as a source of thrombus formation. PMID:19830232

  16. Machine Learning classification of MRI features of Alzheimer's disease and mild cognitive impairment subjects to reduce the sample size in clinical trials.

    PubMed

    Escudero, Javier; Zajicek, John P; Ifeachor, Emmanuel

    2011-01-01

    There is a need for objective tools to help clinicians to diagnose Alzheimer's Disease (AD) early and accurately and to conduct Clinical Trials (CTs) with fewer patients. Magnetic Resonance Imaging (MRI) is a promising AD biomarker but no single MRI feature is optimal for all disease stages. Machine Learning classification can address these challenges. In this study, we have investigated the classification of MRI features from AD, Mild Cognitive Impairment (MCI), and control subjects from ADNI with four techniques. The highest accuracy rates for the classification of controls against ADs and MCIs were 89.2% and 72.7%, respectively. Moreover, we used the classifiers to select AD and MCI subjects who are most likely to decline for inclusion in hypothetical CTs. Using the hippocampal volume as an outcome measure, we found that the required group sizes for the CTs were reduced from 197 to 117 AD patients and from 366 to 215 MCI subjects. PMID:22256186

  17. Ultrafast superconducting single-photon detector with reduced-size active area coupled to a tapered lensed single-mode fiber

    NASA Astrophysics Data System (ADS)

    Sidorova, Maria V.; Divochiy, Alexander; Vachtomin, Yury B.; Smirnov, Konstantin V.

    2015-05-01

    We present an ultrafast NbN Superconducting single-photon detector (SSPD) with active area of 3x3 μm2, which reveals better timing performances than a previously developed SSPD with active area of 10x10 μm2. The improved SSPD demonstrates the record timing jitter <25 ps, ultra short recovery time <2 ns, extremely low dark counts level, and high detection efficiency (DE) in a wide spectral range from visible to near-infrared. The record parameters were obtained thanks to the development of a new technique of an effective optical coupling between a detector with reduced-size active area and a standard single-mode telecommunication fiber. The advantages of a new approach are experimentally confirmed by performed electro-optical measurements of the device performances.

  18. A reduced-order integral formulation to account for the finite size effect of isotropic square panels using the transfer matrix method.

    PubMed

    Bonfiglio, Paolo; Pompoli, Francesco; Lionti, Riccardo

    2016-04-01

    The transfer matrix method is a well-established prediction tool for the simulation of sound transmission loss and the sound absorption coefficient of flat multilayer systems. Much research has been dedicated to enhancing the accuracy of the method by introducing a finite size effect of the structure to be simulated. The aim of this paper is to present a reduced-order integral formulation to predict radiation efficiency and radiation impedance for a panel with equal lateral dimensions. The results are presented and discussed for different materials in terms of radiation efficiency, sound transmission loss, and the sound absorption coefficient. Finally, the application of the proposed methodology for rectangular multilayer systems is also investigated and validated against experimental data. PMID:27106325

  19. THE IMPACT OF HISTOLOGY ON CLINICOPATHOLOGIC OUTCOMES FOR PATIENTS WITH RENAL CELL CARCINOMA AND VENOUS TUMOR THROMBUS: A MATCHED COHORT ANALYSIS

    PubMed Central

    Kaushik, Dharam; Linder, Brian J.; Thompson, R. Houston; Eisenberg, Manuel S.; Lohse, Christine M.; Cheville, John C.; Leibovich, Bradley C.; Boorjian, Stephen A.

    2013-01-01

    Objectives To evaluate the impact of tumor histology on clinicopathologic outcomes for patients with renal cell carcinoma (RCC) and venous tumor thrombus (VTT). Methods We identified 807 patients with RCC and VTT who underwent nephrectomy at our institution between 1970–2008. All pathologic specimens were re-reviewed by a single urologic pathologist. Patients with non-clear cell RCC (non-ccRCC) (n=56) were matched 1:2 to patients with clear cell RCC (ccRCC) VTT based onsymptoms at presentation, regional lymph node involvement, distant metastases, tumor thrombus level, nuclear grade and sarcomatoid differentiation. Survival was estimated using the Kaplan-Meier method and compared with the log-rank test. Results The 56 patients with non-ccRCC VTT included 26 papillary, 11 chromophobe, 5 collecting duct tumors, and 14 RCC not otherwise specified. Compared to unmatched patients with ccRCC VTT (n=751), patients with non-ccRCC VTT presented with larger tumor size (p=0.02), higher nuclear grade (p=0.04), and more frequent sarcomatoid differentiation (p<0.001) and lymph node invasion (p<0.001). However, when patients with non-ccRCC were matched to patients with cc-RCC, no significant differences were noted with regard to 5-year metastases-free survival (41% versus 34%; p=0.24) or cancer-specific survival (25% versus 27%; p=0.97). Conclusions Non-ccRCC VTT is associated with a high rate of adverse pathologic features. Nevertheless, when matched to patients with ccRCC, patients with non-ccRCC VTT did not have increased rates of recurrence or adverse survival. Aggressive surgical resection represents the mainstay of treatment in these cases, while continued efforts to optimize a multimodal management approach to such patients remain necessary. PMID:23642851

  20. Unusual Finding of a Tumor Thrombus Arising From Osteosarcoma Detected on 18F-NaF PET/CT.

    PubMed

    Verma, Priyanka; Purandare, Nilendu; Agrawal, Archi; Shah, Sneha; Rangarajan, Venkatesh

    2016-06-01

    Osteosarcoma is the most common bone sarcoma in adolescents and children. Tumor thrombus arising from osteosarcoma is rare. We describe the case of a 13-year-old girl with osteosarcoma of the right femur, in whom the F-NaF PET/CT was done for initial staging to look for skeletal metastases. The scan showed abnormal increased tracer uptake in the primary tumor and the right common femoral and external iliac vein representing a tumor thrombus. Our case emphasizes the importance of extraosseous findings on F-NaF PET/CT, which may result in important management changes. PMID:26909709

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

    PubMed Central

    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. PMID:26664756

  2. LIGA20, a lyso derivative of ganglioside GM1, given orally after cortical thrombosis reduces infarct size and associated cognition deficit.

    PubMed Central

    Kharlamov, A; Zivkovic, I; Polo, A; Armstrong, D M; Costa, E; Guidotti, A

    1994-01-01

    A bilateral photochemically induced thrombotic lesion of rat sensorimotor cortex (approximately 3 mm in diameter and 25 mm3 in volume) is associated with a persistent cognition (learning and memory) deficit, which was evaluated with water maze tasks. The N-dichloroacetylsphingosine derivative of lysoGM1 (LIGA20) administered after the lesion either i.v. or per or reduces the infarct size by 30-40% and attenuates the associated cognition deficits, presumably by limiting the extent of damage of neurons at risk located in the surroundings of the infarcted core (i.e., area penumbra). The LIGA20 protection is dose and time dependent. Maximal protection is afforded by a single dose of LIGA20 of 34 mumol/kg i.v. 1 hr after lesion or by a dose of 270 mumol/kg per os when administered 1 hr and 24 hr after the lesion. The protective effect of LIGA20 can be observed when the drug is administered i.v. up to 6 hr after the lesion. The protective efficacy of the oral administration of LIGA20 is related to its physiochemical properties, which, unlike those of GM1, allow absorption from the gastrointestinal tract. LIGA20 given orally reaches the brain promptly and rapidly inserts into the neuronal membranes. Here, by an unknown molecular mechanism, LIGA20 selectively reduces the pathological amplification of Ca2+ signaling elicited by persistent stimulation of ionotropic glutamate receptors in the area penumbra. PMID:8022776

  3. Left ventricular assist device inflow cannula thrombus: characterization with two-dimensional transthoracic echocardiography.

    PubMed

    Missov, Emil

    2013-01-01

    Thrombotic complications are inherent to current generation nonpulsatile left ventricular assist devices. The clinical expression of device thrombosis ranges from catastrophic failure to protracted and indolent. We report the case of a 79-year-old patient who received a left ventricular assist device as destination therapy and presented only with vague clinical symptoms. He was found to have a large thrombus in close proximity with the inflow cannula at the left ventricular apex, raising the question of mechanical obstruction. We describe the step-by-step contrast-enhanced two-dimensional transthoracic echocardiographic examination which allowed to obtain diagnostic acoustic tomograms of the inflow cannula and obviated the need for any additional imaging modalities. Transthoracic echocardiography (TTE) is the most common imaging modality used in the clinical follow-up of left ventricular assist device recipients. A frequent clinical indication for TTE is to exclude left ventricular apical thrombus near the inflow cannula. Imaging of the inflow cannula at the left ventricular apex in the traditional apical 4 chamber, apical 2 chamber, and parasternal long axis views is challenging by TTE mainly because of poor acoustic windows, image artifacts, large body habitus, and operator experience. PMID:24172272

  4. Right Ventricular Thrombus and Cerebral Artery Aneurysm in a Patient with Behçet's Disease.

    PubMed

    Sabzi, Feridoun; Mirzaei, Samaneh; Faraji, Reza

    2016-05-01

    We report a 35-year-old woman referred to the Imam Ali Hospital, Kermanshah, Iran, in July 2014 for evaluation of postoperative dyspnoea after neurosurgery performed seven days previously for a ruptured cerebral artery aneurysm. She was known to have Behçet's disease with a history of recurrent oral and genital aphthous ulcers and uveitis. At referral, her symptoms included vertigo, dysarthria, palpitations and chest pain. Transthoracic echocardiography (TTE) revealed a large thrombus in her right ventricle outflow tract and open-heart surgery was performed eight days after the previous surgery to remove the clot. The postoperative period was complicated by transient acute renal failure, which resolved spontaneously. The patient was discharged 13 days after the cardiac surgery on warfarin, prednisolone, azathioprine and cyclophosphamide. Cyclophosphamide and azathioprine were discontinued after three months as the symptoms had completely resolved; however, prednisolone was continued due to recurrent uveitis. A 10-month follow-up TTE scan revealed no thrombus recurrence and treatment with warfarin and prednisolone was continued. PMID:27226921

  5. Development of Ga-67 labeled DFO-DAS-fibrinogen conjugate as a thrombus imaging agent.

    PubMed

    Yamaoka, S

    1987-01-01

    A cluster method developed for labeling large molecular proteins with radioactive metal was applied for 67Ga-labeled fibrinogen. A large number of deferoxamine (DFO) was introduced to human fibrinogen using dialdehyde strarch (DAS) as a spacer-functional polymer. The synthesized DFO-DAS-fibrinogen mentioned above was easily labeled with GaCl3 (67Ga) solution (2 mCi/5 mg). The basic investigations found that 67Ga-DFO-DAS-fibrinogen was applicable to the diagnosis of thrombus, and clinical trials were carried out under the physician-sponsored IND. In our further investigation, improvement of the 67Ga-DFO-DAS-fibrinogen reagent was attempted to obtain high specific radioactivity. This was accomplished with the more familiar 67Ga citrate. From the results of a series of experiments, 67Ga-DFO-DAS-fibrinogen of a new composition labeled using 67Ga citrate with high specific radioactivity (2 mCi/3 mg) was prepared, and both reagents were evaluated as thrombus imaging agents from the chemical and biological aspects. The labeling efficiency and clottability of both 67Ga-DFO-DAS-fibrinogen conjugates were satisfactorily high, more than 95% and 80%, respectively. The biodistribution in rats showed that both 67Ga-DFO-DAS-fibrinogen conjugates were essentially the same. These results suggest that there are no significant differences between reagents. At present, the improved reagents are being supplied for the second clinical trials under physician-sponsored IND. PMID:3438481

  6. Management of inferior vena cava tumor thrombus in locally advanced renal cell carcinoma

    PubMed Central

    Psutka, Sarah P.

    2015-01-01

    The diagnosis of renal cell carcinoma is accompanied by intravascular tumor thrombus in up to 10% of cases, of which nearly one-third of patients also have concurrent metastatic disease. Surgical resection in the form of radical nephrectomy and caval thrombectomy represents the only option to obtain local control of the disease and is associated with durable oncologic control in approximately half of these patients. The objective of this clinical review is to outline the preoperative evaluation for, and operative management of patients with locally advanced renal cell carcinoma with venous tumor thrombi involving the inferior vena cava. Cornerstones of the management of these complex patients include obtaining high-quality imaging to characterize the renal mass and tumor thrombus preoperatively, with further intraoperative real-time evaluation using transesophageal echocardiography, careful surgical planning, and a multidisciplinary approach. Operative management of patients with high-level caval thrombi should be undertaken in high-volume centers by surgical teams with capacity for bypass and invasive intraoperative monitoring. In patients with metastatic disease at presentation, cytoreductive nephrectomy and tumor thrombectomy may be safely performed with simultaneous metastasectomy if possible. In the absence of level one evidence, neoadjuvant targeted therapy should continue to be viewed as experimental and should be employed under the auspices of a clinical trial. However, in patients with significant risk factors for postoperative complications and mortality, and especially in those with metastatic disease, consultation with medical oncology and frontline targeted therapy may be considered. PMID:26445601

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

    SciTech Connect

    Nickel, Barbara; McClure, Timothy Moriarty, John

    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.

  8. Image-based characterization of thrombus formation in time-lapse DIC microscopy

    PubMed Central

    Brieu, Nicolas; Navab, Nassir; Serbanovic-Canic, Jovana; Ouwehand, Willem H.; Stemple, Derek L.; Cvejic, Ana; Groher, Martin

    2012-01-01

    The characterization of thrombus formation in time-lapse DIC microscopy is of increased interest for identifying genes which account for atherothrombosis and coronary artery diseases (CADs). In particular, we are interested in large-scale studies on zebrafish, which result in large amount of data, and require automatic processing. In this work, we present an image-based solution for the automatized extraction of parameters quantifying the temporal development of thrombotic plugs. Our system is based on the joint segmentation of thrombotic and aortic regions over time. This task is made difficult by the low contrast and the high dynamic conditions observed in vivo DIC microscopic scenes. Our key idea is to perform this segmentation by distinguishing the different motion patterns in image time series rather than by solving standard image segmentation tasks in each image frame. Thus, we are able to compensate for the poor imaging conditions. We model motion patterns by energies based on the idea of dynamic textures, and regularize the model by two prior energies on the shape of the aortic region and on the topological relationship between the thrombus and the aorta. We demonstrate the performance of our segmentation algorithm by qualitative and quantitative experiments on synthetic examples as well as on real in vivo microscopic sequences. PMID:22482997

  9. Engineering of plasminogen activators for targeting to thrombus and heightening thrombolytic efficacy.

    PubMed

    Absar, S; Gupta, N; Nahar, K; Ahsan, F

    2015-09-01

    Thrombotic occlusion of the coronary artery, which triggers acute myocardial infarction, is one of the major causes of death in the USA. Currently, arterial occlusions are treated with intravenous plasminogen activators (PAs), which dissolve the clot by activating plasminogen. However, PAs indiscriminately generate plasmin, which depletes critical clotting factors (fibrinogen, factor V, and factor VIII), precipitates a lytic state in the blood, and produces bleeding complications in a large patient population. PAs have been extensively investigated to achieve thrombus specificity, to attenuate the bleeding risk, and to widen their clinical applications. In this review, we discuss various strategies that have been pursued since the beginning of thrombolytic therapy. We review the biotechnological approaches that have been used to develop mutant and chimeric PAs for thrombus selectivity, including the use of specific antibodies for targeting thrombi. We discuss particulate carrier-based systems and triggered-release concepts. We propose new hypotheses and strategies to spur future studies in this research arena. Overall, we describe the approaches and accomplishments in the development of patient-friendly and workable delivery systems for thrombolytic drugs. PMID:26074048

  10. Tripeptide SQL Inhibits Platelet Aggregation and Thrombus Formation by Affecting PI3K/Akt Signaling.

    PubMed

    Su, Xing-li; Su, Wen; He, Zhi-long; Ming, Xin; Kong, Yi

    2015-09-01

    Centipede has been prescribed for the treatment of cardiovascular diseases in Asian countries for several hundred years. Previously, a new antiplatelet tripeptide SQL (H-Ser-Gln-Leu-OH) was isolated and characterized from centipede. In this study, we investigated its antithrombotic activities in vivo and underlying mechanism. It was found that SQL inhibited platelet aggregation induced by adenosine diphosphate, thrombin, epinephrine, and collagen and attenuated thrombus formation in both the ferric chloride-induced arterial thrombosis model and arteriovenous shunt thrombosis model in rats. It did not prolong the bleeding time in mice even at the dose of 10 mg/kg that showed potent antithrombosis effects. Molecular docking revealed that SQL binds PI3Kβ with the binding free energy of -24.341 kcal/mol, which is close to that of cocrystallized ligand (-24.220 kcal/mol). Additionally, SQL displayed inhibition on the late (180 seconds) but did not influence the early (60 seconds) Akt Ser473 phosphorylation in the immunoblot assay. These results suggest that SQL inhibits thrombus formation in vivo and that SQL inhibits PI3K-mediated signaling or even the PI3K itself in platelets. This study may help elucidate the mechanism for centipede treating cardiovascular diseases. PMID:25923322

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

    PubMed Central

    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. 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. Results: 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. Conclusions: 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. PMID:18184880

  12. [Successful endovascular repair of a ruptured thoracoabdominal aortic aneurysm with severe mural thrombus].

    PubMed

    Nakao, Yoshihisa; Akagi, Haruhiko; Irie, Hiroshi; Sakaguchi, Shoji; Sakai, Kei

    2014-11-01

    A 51-year-old man was transferred to our hospital on an emergency basis complaining of a sudden onset of severe left lumbar back pain. An emergency contrasted computed tomography showed a ruptured thoracoabdominal aortic aneurysm( rTAAA:Crawford classification type III). The ruptured site was near the aortic bifurcation, and the aneurysm had a relatively narrow segment with an extensive mural thrombus just below the renal arteries. Considering the high mortality of open surgery for the rTAAA and the poor general condition of the patient, we decided to perform endovascular aneurysm repair (EVAR) as a rescue procedure using the narrowed segment by the thrombus for a proximal landing zone. The abdominal part of the thoracoabdominal aortic aneurysm (TAAA) was successfully excluded with a stent graft to obtain complete hemostasis. The postoperative course was uneventful except for the need for hemodialysis. Even though there is a risk of developing late type 1 endoleak, this procedure can be a feasible option as a rescue procedure or a bridge to radical open surgery for ruptured TAAA in a specially anatomical setting like this case. PMID:25391465

  13. Inhibition of Mas G-protein signaling improves coronary blood flow, reduces myocardial infarct size, and provides long-term cardioprotection.

    PubMed

    Zhang, Tong; Li, Zhuangjie; Dang, Huong; Chen, Ruoping; Liaw, Chen; Tran, Thuy-Anh; Boatman, P Douglas; Connolly, Daniel T; Adams, John W

    2012-01-01

    The Mas receptor is a class I G-protein-coupled receptor that is expressed in brain, testis, heart, and kidney. The intracellular signaling pathways activated downstream of Mas are still largely unknown. In the present study, we examined the expression pattern and signaling of Mas in the heart and assessed the participation of Mas in cardiac ischemia-reperfusion injury. Mas mRNA and protein were present in all chambers of human hearts, with cardiomyocytes and coronary arteries being sites of enriched expression. Expression of Mas in either HEK293 cells or cardiac myocytes resulted in constitutive coupling to the G(q) protein, which in turn activated phospholipase C and caused inositol phosphate accumulation. To generate chemical tools for use in probing the function of Mas, we performed a library screen and chemistry optimization program to identify potent and selective nonpeptide agonists and inverse agonists. Mas agonists activated G(q) signaling in a dose-dependent manner and reduced coronary blood flow in isolated mouse and rat hearts. Conversely, treatment of isolated rat hearts with Mas inverse agonists improved coronary flow, reduced arrhythmias, and provided cardioprotection from ischemia-reperfusion injury, an effect that was due, at least in part, to decreased cardiomyocyte apoptosis. Participation of Mas in ischemia-reperfusion injury was confirmed in Mas knockout mice, which had reduced infarct size relative to mice with normal Mas expression. These results suggest that activation of Mas during myocardial infarction contributes to ischemia-reperfusion injury and further suggest that inhibition of Mas-G(q) signaling may provide a new therapeutic strategy directed at cardioprotection. PMID:22003054

  14. Single Photon Emission Computed Tomography-Based Three-Dimensional Conformal Radiotherapy for Hepatocellular Carcinoma With Portal Vein Tumor Thrombus

    SciTech Connect

    Shirai, Shintaro; Sato, Morio Suwa, Kazuhiro; Kishi, Kazushi; Shimono, Chigusa; Kawai, Nobuyuki; Tanihata, Hirohiko; Minamiguchi, Hiroki; Nakai, Motoki

    2009-03-01

    Purpose: To evaluate the safety and efficacy of three-dimensional conformal radiotherapy (3D-CRT) using single photon emission computed tomography (SPECT) in unresectable hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT). Methods and Materials: Patients with HCC with PVTT in the first branch and/or main trunk were selected for this study. The optimal beam directions for 3D-CRT were explored using a Tc-99m-galactosyl human serum albumin SPECT image for guidance. The SPECT image was classified as either wedge type or localized type. The clinical target volume to a total dose of 45 or 50 Gy per 18-20 fractions included the main tumor and PVTT in the wedge type and PVTT alone in the localized type. Results: Twenty-six patients were enrolled: 18 with wedge type and 8 with localized type. Mean tumor size was 7.1 cm (range, 4.4-12.3 cm). Clinical target volumes of wedge type vs. localized type were 111.2 cm{sup 3} vs. 48.4 cm{sup 3} (p = 0.010), respectively. Mean dose to normal liver and mean dose to functional liver were 1185 cGy and 988 cGy (p = 0.001) in wedge type and 1046 cGy and 1043 cGy (p = 0.658) in localized type, respectively. Despite an incidence of Child-Pugh B and C of 57.7%, no patients experienced radiation-induced liver disease. The progression of PVTT was inhibited, with an incidence of 92.2%; survival rates at 1 and 2 years were 44% and 30%, respectively. Conclusion: Single photon emission computed tomography-based 3D-CRT enables irradiation of both the main tumor and PVTT with low toxicity and promising survival.

  15. Glial restricted precursor cell transplant with cyclic adenosine monophosphate improved some autonomic functions but resulted in a reduced graft size after spinal cord contusion injury in rats.

    PubMed

    Nout, Yvette S; Culp, Esther; Schmidt, Markus H; Tovar, C Amy; Pröschel, Christoph; Mayer-Pröschel, Margot; Noble, Mark D; Beattie, Michael S; Bresnahan, Jacqueline C

    2011-01-01

    Transplantation of glial restricted precursor (GRP) cells has been shown to reduce glial scarring after spinal cord injury (SCI) and, in combination with neuronal restricted precursor (NRP) cells or enhanced expression of neurotrophins, to improve recovery of function after SCI. We hypothesized that combining GRP transplants with rolipram and cAMP would improve functional recovery, similar to that seen after combining Schwann cell transplants with increasing cAMP. A short term study, (1) uninjured control, (2) SCI+vehicle, and (3) SCI+cAMP, showed that spinal cord [cAMP] was increased 14days after SCI. We used 51 male rats subjected to a thoracic SCI for a 12-week survival study: (1) SCI+vehicle, (2) SCI+GRP, (3) SCI+cAMP, (4) SCI+GRP+cAMP, and (5) uninjured endpoint age-matched control (AM). Rolipram was administered for 2weeks after SCI. At 9days after SCI, GRP transplantation and injection of dibutyryl-cAMP into the spinal cord were performed. GRP cells survived, differentiated, and formed extensive transplants that were well integrated with host tissue. Presence of GRP cells increased the amount of tissue in the lesion; however, cAMP reduced the graft size. White matter sparing at the lesion epicenter was not affected. Serotonergic input to the lumbosacral spinal cord was not affected by treatment, but the amount of serotonin immediately caudal to the lesion was reduced in the cAMP groups. Using telemetric monitoring of corpus spongiosum penis pressure we show that the cAMP groups regained the same number of micturitions per 24hours when compared to the AM group, however, the frequency of peak pressures was increased in these groups compared to the AM group. In contrast, the GRP groups had similar frequency of peak pressures compared to baseline and the AM group. Animals that received GRP cells regained the same number of erectile events per 24hours compared to baseline and the AM group. Since cAMP reduced the GRP transplant graft, and some modest positive

  16. Strong correlation in acene sheets from the active-space variational two-electron reduced density matrix method: effects of symmetry and size.

    PubMed

    Pelzer, Kenley; Greenman, Loren; Gidofalvi, Gergely; Mazziotti, David A

    2011-06-01

    Polyaromatic hydrocarbons (PAHs) are a class of organic molecules with importance in several branches of science, including medicine, combustion chemistry, and materials science. The delocalized π-orbital systems in PAHs require highly accurate electronic structure methods to capture strong electron correlation. Treating correlation in PAHs has been challenging because (i) traditional wave function methods for strong correlation have not been applicable since they scale exponentially in the number of strongly correlated orbitals, and (ii) alternative methods such as the density-matrix renormalization group and variational two-electron reduced density matrix (2-RDM) methods have not been applied beyond linear acene chains. In this paper we extend the earlier results from active-space variational 2-RDM theory [Gidofalvi, G.; Mazziotti, D. A. J. Chem. Phys. 2008, 129, 134108] to the more general two-dimensional arrangement of rings--acene sheets--to study the relationship between geometry and electron correlation in PAHs. The acene-sheet calculations, if performed with conventional wave function methods, would require wave function expansions with as many as 1.5 × 10(17) configuration state functions. To measure electron correlation, we employ several RDM-based metrics: (i) natural-orbital occupation numbers, (ii) the 1-RDM von Neumann entropy, (iii) the correlation energy per carbon atom, and (iv) the squared Frobenius norm of the cumulant 2-RDM. The results confirm a trend of increasing polyradical character with increasing molecular size previously observed in linear PAHs and reveal a corresponding trend in two-dimensional (arch-shaped) PAHs. Furthermore, in PAHs of similar size they show significant variations in correlation with geometry. PAHs with the strictly linear geometry (chains) exhibit more electron correlation than PAHs with nonlinear geometries (sheets). PMID:21563790

  17. Up-regulation of heme oxygenase-1 after infarct initiation reduces mortality, infarct size and left ventricular remodeling: experimental evidence and proof of concept

    PubMed Central

    2014-01-01

    Background Up-regulation of HO-1 by genetic manipulation or pharmacological pre-treatment has been reported to provide benefits in several animal models of myocardial infarction (MI). However, its efficacy following MI initiation (as in clinical reality) remains to be tested. Therefore, this study investigated whether HO-1 over-expression, by cobalt protoporphyrin (CoPP) administered after LAD ligation, is still able to improve functional and structural changes in left ventricle (LV) in a rat model of 4-week MI. Methods A total of 144 adult male Wistar rats were subjected to either left anterior coronary artery ligation or sham-operation. The effect of CoPP treatment (5 mg/kg i.p. at the end of the surgical session and, then, once a week for 4 weeks) was evaluated on the basis of survival, electro- and echocardiography, plasma levels of B-type natriuretic peptide (BNP), endothelin-1 and prostaglandin E2, coronary microvascular reactivity, MI size, LV wall thickness and vascularity. Besides, the expression of HO-1 and connexin-43 in different LV territories was assessed by western blot analysis and immunohistochemistry, respectively. Results CoPP induced an increased expression of HO-1 protein with >16 h delay. CoPP treatment significantly reduced mortality, MI size, BNP concentration, ECG alterations, LV dysfunction, microvascular constriction, capillary rarefaction and restored connexin-43 expression as compared to untreated MI. These functional and structural changes were paralleled by increased HO-1 expression in all LV territories. HO activity inhibition by tin-mesoporphyrin abolished the differences between CoPP-treated and untreated MI animals. Conclusions This is the first report demonstrating the putative role of pharmacological induction of HO-1 following coronary occlusion to benefit infarcted and remote territories, leading to better cardiac function in a 4-week MI outcome. PMID:24708733

  18. Rapid Surface Cooling by ThermoSuit System Dramatically Reduces Scar Size, Prevents Post-Infarction Adverse Left Ventricular Remodeling, and Improves Cardiac Function in Rats

    PubMed Central

    Dai, Wangde; Herring, Michael J; Hale, Sharon L; Kloner, Robert A

    2015-01-01

    Background The long-term effects of transient hypothermia by the non-invasive ThermoSuit apparatus on myocardial infarct (MI) scar size, left ventricular (LV) remodeling, and LV function were assessed in rat MI model. Methods and Results Rats were randomized to normothermic or hypothermic groups (n=14 in each group) and subjected to 30 minutes coronary artery occlusion and 6 weeks of reperfusion. For hypothermia therapy, rats were placed into the ThermoSuit apparatus at 2 minutes after the onset of coronary artery occlusion, were taken out of the apparatus when the core body temperature reached 32°C (in ≈8 minutes), and were then allowed to rewarm. After 6 weeks of recovery, rats treated with hypothermia demonstrated markedly reduced scar size (expressed as % of left ventricular area: hypothermia, 6.5±1.1%; normothermia, 19.4±1.7%; P=1.3×10−6); and thicker anterior LV wall (hypothermia, 1.57±0.09 mm; normothermia, 1.07±0.05 mm; P=3.4×10−5); decreased postmortem left ventricular volume (hypothermia, 0.45±0.04 mL; normothermia, 0.6±0.03 mL; P=0.028); and better LV fractional shortening by echocardiography (hypothermia, 37.2±2.8%; normothermia, 18.9±2.3%; P=0.0002) and LV ejection fraction by LV contrast ventriculography (hypothermia, 66.8±2.3%; normothermia, 56.0±2.0%; P=0.0014). Conclusions Rapid, transient non-invasive surface cooling with the ThermoSuit apparatus in the acute phase of MI decreased scar size by 66.5%, attenuated adverse post-infarct left ventricular dilation and remodeling, and improved cardiac function in the chronic phase of experimental MI. PMID:26116692

  19. Effect of Thrombus Composition and Viscosity on Sonoreperfusion Efficacy in a Model of Micro-Vascular Obstruction.

    PubMed

    Black, John J; Yu, Francois T H; Schnatz, Rick G; Chen, Xucai; Villanueva, Flordeliza S; Pacella, John J

    2016-09-01

    Distal embolization of micro-thrombi during stenting for myocardial infarction causes micro-vascular obstruction (MVO). We have previously shown that sonoreperfusion (SRP), a microbubble (MB)-mediated ultrasound (US) therapy, resolves MVO from venous micro-thrombi in vitro in saline. However, blood is more viscous than saline, and arterial thrombi that embolize during stenting are mechanically distinct from venous clot. Therefore, we tested the hypothesis that MVO created with arterial micro-thrombi are more resistant to SRP therapy compared with venous micro-thrombi, and higher viscosity further increases the US requirement for effective SRP in an in vitro model of MVO. Lipid MBs suspended in plasma with adjusted viscosity (1.1 cP or 4.0 cP) were passed through tubing bearing a mesh with 40-μm pores to simulate a micro-vascular cross-section; upstream pressure reflected thrombus burden. To simulate MVO, the mesh was occluded with either arterial or venous micro-thrombi to increase upstream pressure to 40 mmHg ± 5 mmHg. Therapeutic long-tone-burst US was delivered to the occluded area for 20 min. MB activity was recorded with a passive cavitation detector. MVO caused by arterial micro-thrombi at either blood or plasma viscosity resulted in less effective SRP therapy compared to venous thrombi. Higher viscosity further reduced the effectiveness of SRP therapy. The passive cavitation detector showed a decrease in inertial cavitation when viscosity was increased, while stable cavitation was affected in a more complex manner. Overall, these data suggest that arterial thrombi may require higher acoustic pressure US than venous thrombi to achieve similar SRP efficacy; increased viscosity decreases SRP efficacy; and both inertial and stable cavitation are implicated in observed SRP efficacy. PMID:27207018

  20. Phycobilisome-Deficient Strains of Synechocystis sp. PCC 6803 Have Reduced Size and Require Carbon-Limiting Conditions to Exhibit Enhanced Productivity1[W][OPEN

    PubMed Central

    Lea-Smith, David J.; Bombelli, Paolo; Dennis, John S.; Scott, Stuart A.; Smith, Alison G.; Howe, Christopher J.

    2014-01-01

    Reducing excessive light harvesting in photosynthetic organisms may increase biomass yields by limiting photoinhibition and increasing light penetration in dense cultures. The cyanobacterium Synechocystis sp. PCC 6803 harvests light via the phycobilisome, which consists of an allophycocyanin core and six radiating rods, each with three phycocyanin (PC) discs. Via targeted gene disruption and alterations to the promoter region, three mutants with two (pcpcT→C) and one (ΔCpcC1C2:pcpcT→C) PC discs per rod or lacking PC (olive) were generated. Photoinhibition and chlorophyll levels decreased upon phycobilisome reduction, although greater penetration of white light was observed only in the PC-deficient mutant. In all strains cultured at high cell densities, most light was absorbed by the first 2 cm of the culture. Photosynthesis and respiration rates were also reduced in the ΔCpcC1C2:pcpcT→C and olive mutants. Cell size was smaller in the pcpcT→C and olive strains. Growth and biomass accumulation were similar between the wild-type and pcpcT→C under a variety of conditions. Growth and biomass accumulation of the olive mutant were poorer in carbon-saturated cultures but improved in carbon-limited cultures at higher light intensities, as they did in the ΔCpcC1C2:pcpcT→C mutant. This study shows that one PC disc per rod is sufficient for maximal light harvesting and biomass accumulation, except under conditions of high light and carbon limitation, and two or more are sufficient for maximal oxygen evolution. To our knowledge, this study is the first to measure light penetration in bulk cultures of cyanobacteria and offers important insights into photobioreactor design. PMID:24760817

  1. Thrombin-initiated platelet activation in vivo is vWF independent during thrombus formation in a laser injury model

    PubMed Central

    Dubois, Christophe; Panicot-Dubois, Laurence; Gainor, Justin F.; Furie, Barbara C.; Furie, Bruce

    2007-01-01

    Adhesion of platelets to an injured vessel wall and platelet activation are critical events in the formation of a thrombus. Of the agonists involved in platelet activation, thrombin, collagen, and vWF are known to induce in vitro calcium mobilization in platelets. Using a calcium-sensitive fluorochrome and digital multichannel intravital microscopy to image unstimulated and stimulated platelets, calcium mobilization was monitored as a reporter of platelet activation (as distinct from platelet accumulation) during thrombus formation in live mice. In the absence of vWF, platelet activation was normal, but platelet adherence and aggregation were attenuated during thrombus formation following laser-induced injury in the cremaster muscle microcirculation. In WT mice treated with lepirudin, platelet activation was blocked, and platelet adherence and aggregation were inhibited. The kinetics of platelet activation and platelet accumulation were similar in FcRγ–/– mice lacking glycoprotein VI (GPVI), GPVI-depleted mice, and WT mice. Our results indicate that the tissue factor–mediated pathway of thrombin generation, but not the collagen-induced GPVI-mediated pathway, is the major pathway leading to platelet activation after laser-induced injury under the conditions employed. In the tissue factor–mediated pathway, vWF plays a role in platelet accumulation during thrombus formation but is not required for platelet activation in vivo. PMID:17380206

  2. Local Quantification of Wall Thickness and Intraluminal Thrombus Offer Insight into the Mechanical Properties of the Aneurysmal Aorta.

    PubMed

    Martufi, Giampaolo; Satriano, Alessandro; Moore, Randy D; Vorp, David A; Di Martino, Elena S

    2015-08-01

    Wall stress is a powerful tool to assist clinical decisions in rupture risk assessment of abdominal aortic aneurysms. Key modeling assumptions that influence wall stress magnitude and distribution are the inclusion or exclusion of the intraluminal thrombus in the model and the assumption of a uniform wall thickness. We employed a combined numerical-experimental approach to test the hypothesis that abdominal aortic aneurysm (AAA) wall tissues with different thickness as well as wall tissues covered by different thrombus thickness, exhibit differences in the mechanical behavior. Ultimate tissue strength was measured from in vitro tensile testing of AAA specimens and material properties of the wall were estimated by fitting the results of the tensile tests to a histo-mechanical constitutive model. Results showed a decrease in tissue strength and collagen stiffness with increasing wall thickness, supporting the hypothesis of wall thickening being mediated by accumulation of non load-bearing components. Additionally, an increase in thrombus deposition resulted in a reduction of elastin content, collagen stiffness and tissue strength. Local wall thickness and thrombus coverage may be used as surrogate measures of local mechanical properties of the tissue, and therefore, are possible candidates to improve the specificity of AAA wall stress and rupture risk evaluations. PMID:25631202

  3. Swine Model of Thrombotic Caval Occlusion Created by Autologous Thrombus Injection with Assistance of Intra-caval Net Knitting

    PubMed Central

    Shi, Wan-Yin; Wu, Shuang; Hu, Lan-Yue; Liu, Chang-Jian; Gu, Jian-Ping

    2015-01-01

    To evaluate the feasibility of a swine model of thrombotic inferior vena cava (IVC) occlusion (IVCO) created by autologous thrombus injection with assistance of intra-caval net knitting. Sixteen pigs were included and divided into two groups: Group A (n = 10), IVCO model created by knitting a caval net followed by autologous thrombus injection; Group B (n = 6), control model created by knitting a net and normal saline injection. Venography was performed to assess each model and the associated thrombotic occlusion. The vessels were examined histologically to analyse the pathological changes postoperatively. IVCO model was successfully created in 10 animals in Group A (100%). Immediate venography showed extensive clot burden in the IVC. Postoperative venography revealed partial caval occlusion at 7 days, and complete occlusion coupled with collateral vessels at 14 days. Histologically, Group A animals had significantly greater venous wall thickening, with CD163-positive and CD3-positive cell infiltration. Recanalization channels were observed at the margins of the thrombus. By contrast, no thrombotic occlusion of the IVC was observed in Group B. The thrombotic IVCO model can be reliably established in swine. The inflammatory reaction may contribute to the caval thrombus propagation following occlusion. PMID:26680253

  4. Precise control of caval and hepatic vessels: Surgical technique to treat level III caval thrombus concomitant to renal cell carcinoma

    PubMed Central

    Chen, Ming; Xu, Bin; Liu, Ning; Jiang, Hua; Wang, Yiduo; Yang, Yu; Zhang, Xiaowen; Sun, Chao; Liu, Jing; Zhu, Weidong; Chen, Shuqiu

    2015-01-01

    Introduction: We investigated the surgical techniques, safety, and prevention of complications of nephrectomy and removal of tumour thrombus for treating level III inferior vena cava (IVC) concomitant to renal cell carcinoma (RCC). We did this by precise controlling IVC and hepatic vessels without a vascular bypass. Methods: In this series, we included 5 patients with level III IVC tumour thrombus below the hepatic vein concomitant to RCC. After precisely controlling the IVC and hepatic vessels, we then removed the thrombus en bloc with the renal vein. Blood loss volume, IVC clamping time, hypotension time, resuscitation, cardiocerebrovascular complications, and postoperative organ dysfunction were observed. Results: Surgery was successfully performed without perioperative death. Blood loss volume was 900 to 1500 mL, operation time was 165 to 250 minutes, vascular clamping time was 8 to 12 minutes, and intraoperative hypotension time was 9 to 12 minutes. Serious perioperative complications were not observed. Local recurrence was not observed during the 9 to 24 months of follow-up. One patient exhibited disease-free survival, 3 developed lung or liver metastasis, and 1 died 11 months after surgery. Conclusion: Precise control of IVC and hepatic pedicle vessels, without vascular bypass, is a safe and effective surgical treatment for level III tumor thrombus below the hepatic vein concomitant to RCC. The procedure was conducted without increased risks of intraoperative hypotensive shock, difficult resuscitation, pulmonary embolism, and multiple organ dysfunctions. PMID:26600890

  5. Comprehensive treatments for hepatocellular carcinoma with tumor thrombus in major portal vein

    PubMed Central

    Ye, Hai-Hong; Ye, Jia-Zhou; Xie, Zhi-Bo; Peng, Yu-Chong; Chen, Jie; Ma, Liang; Bai, Tao; Chen, Jun-Ze; Lu, Zhan; Qin, Hong-Gui; Xiang, Bang-De; Li, Le-Qun

    2016-01-01

    AIM: To evaluate the efficacy of transcatheter arterial chemoembolisation (TACE) compared with surgical intervention and sorafenib for treatment of hepatocellular carcinoma (HCC) in patients with tumor thrombus extending to the main portal vein. METHODS: From 2009 to 2013, a total of 418 HCC patients with tumor thrombus extending to the main portal vein were enrolled in this study and divided into four groups. These groups underwent different treatments as follows: TACE (n = 307), surgical intervention (n = 54), sorafenib (n = 15) and palliative treatment (n = 42). Overall survival rates were determined by Kaplan-Meier method, and differences between the groups were identified through log-rank analysis. Cox’s proportional hazard model was used to identify the risk factors for survival. RESULTS: The mean survival periods for patients in the TACE, surgical intervention, sorafenib and palliative treatment groups were 10.39, 4.13, 5.54 and 2.82 mo, respectively. For the TACE group, the 3-, 6-, 12- and 24-mo survival rates were 94.1%, 85.9%, 51.5% and 0.0%, respectively. The corresponding rates were 60.3%, 22.2%, 0.0% and 0.0% for the surgical intervention group and 50.9%, 29.5%, 0.0% and 0.0% for the sorafenib group. Evidently, the results in the TACE group were significantly higher than those in the other groups (P < 0.0001). Furthermore, no significant difference among survival rates was observed between TACE with/without sorafenib (10.22 mo vs 10.52 mo, P = 0.615). No significant difference in survival rates was also found among the surgical intervention, sorafenib and palliative treatment groups (P > 0.05). These values significantly increased after TACE with/without sorafenib compared with other treatments (P < 0.05). CONCLUSION: For HCC patients with tumor thrombus extending to the main portal vein, TACE can yield a higher survival rate than surgical intervention or sorafenib treatment. PMID:27053855

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

    PubMed Central

    Hong, Theodore S.; Bosch, Walter R.; Krishnan, Sunil; Kim, Tae K.; Mamon, Harvey J.; Shyn, Paul; Ben-Josef, Edgar; Seong, Jinsil; Haddock, Michael G.; Cheng, Jason C.; Feng, Mary U.; Stephans, Kevin L.; Roberge, David; Crane, Christopher; Dawson, Laura A.

    2014-01-01

    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 planning

  7. Direct thrombus aspiration using the Penumbra system for the treatment of pediatric intracranial dissection.

    PubMed

    Fujimoto, Motoaki; Tateshima, Satoshi; Ali, Latisha; Raychev, Radoslav; Vinuela, Fernando

    2013-11-01

    We describe a case of a 15-year-old girl who developed a spontaneous intracranial arterial dissection with distal middle cerebral artery (MCA) occlusions. From the digital subtraction angiography provided, the dissection flap appeared to originate at the internal carotid artery terminus with extension into the right M1 segment and occluding the right anterior cerebral artery, A1 segment. CT perfusion study showed salvageable tissue in the posterior MCA territory, including the motor cortex. In order to avoid further injury to the dissection, clot retrieval systems were not a treatment option. We therefore performed selective thrombus aspiration with the Penumbra system for the occluded central and precentral arteries distal to the non-occlusive dissecting lesion. Sufficient recanalization was achieved and the patient made a marked recovery. Although mechanical thrombectomy with the use of retrieval intracranial stent systems has demonstrated satisfactory recanalization rates, the aspiration methodology remains useful for patients with an accompanying proximal vascular lesion. PMID:23188785

  8. Left atrial thrombus under dabigatran in a patient with nonvalvular atrial fibrillation.

    PubMed

    Janssen, A M; van de Kerkhof, D; Szabó, B; Durian, M F; van der Voort, P H

    2016-08-01

    Dabigatran is a new direct competitive inhibitor of thrombin and is equally effective and safe as warfarin in the prevention of thromboembolism in patients with nonvalvular atrial fibrillation. We present a case of a 60-year-old man with persistent nonvalvular atrial fibrillation who switched from acenocoumarol to dabigatran 110 mg twice daily. After five months the patient developed a large atrial thrombus, occlusion of the tibial arteries of the right foot, cerebellar infarction and multiple infarctions in kidneys and spleen. Blood test showed a dabigatran concentration of 35 ng/ml six hours after intake, correlating with a low trough concentration of 24-27 ng/mL and significantly increased thromboembolic risk. Other risk factors for thromboembolism were excluded. The present case indicates that in selected patients, there might be an indication for dose adjustments based on serum levels of dabigatran to ensure patient efficacy (thromboembolic events) and safety (bleeding). PMID:27571947

  9. Thrombus-trapping efficiency of the LGM (Vena Tech) and titanium Greenfield filters in vivo.

    PubMed

    Millward, S F; Marsh, J I; Pon, C; Moher, D

    1992-02-01

    To assess the trapping efficiency of two vena cava filters, 326 radiopaque thrombi 5 mm in diameter were injected into adult sheep: four with LG-Medical (LGM) and four with titanium Greenfield (TG) filters. Thrombi were sequentially injected and not removed. Trapping was monitored fluoroscopically, and the pressure gradient across the filter was measured. The LGM filter trapped 70% of 5 x 5-mm and 100% of 5 x 10-mm thrombi; the TG, 26% of 5 x 5-mm, 34% of 5 x 10-mm, and 37% of 5 x 30-mm thrombi. The LGM filter required an average of 2.0 mL of trapped thrombus to occlude the filter, compared with 6.4 mL for the TG. These differences were statistically significant. These data indicate that in this model, the LGM filter traps thrombi more efficiently than the TG filter but is more likely to produce caval occlusion. PMID:1540709

  10. Greater trunk muscle torque reduces postmenopausal bone loss at the spine independently of age, body size, and vitamin D receptor genotype in Japanese women.

    PubMed

    Iki, M; Saito, Y; Dohi, Y; Kajita, E; Nishino, H; Yonemasu, K; Kusaka, Y

    2002-10-01

    Bone mineral density (BMD) is affected by muscle strength. Recently, vitamin D receptor (VDR) genotype was reported to affect muscle strength as well as BMD in Caucasian women. The aim of this study was to evaluate independent effects of muscle strength of the trunk on BMD at the spine and its change over time in Japanese women. We followed 119 healthy postmenopausal women for 4 years and determined the change in BMD at the spine by dual energy X-ray absorptiometry. Isometric peak torque and isokinetic concentric and eccentric peak torque of the trunk flexors and extensors were measured. The VDR genotype was determined by the PCR-RFLP method based on Apa I and Taq I endonuclease digestions defining the absence/existence of the restriction sites as A/a and T/t, respectively. The subjects were 60.1 +/- 6.6 years old, had 0.808 +/- 0.159 g/cm2 of BMD at baseline. The mean annual change in BMD (delta BMD) was -5.6 +/- 10.4 mg/cm2 during the follow-up period. The VDR genotype, defined by Taq I enzyme, significantly related to BMD at baseline and delta BMD showing that the subjects with genotype TT had the lowest BMD at baseline and lost bone most rapidly. However, its effect on muscle strength was not significant. All the trunk muscle strength indices showed significant positive effects on delta BMD, that is, the effects in increasing the gain and reducing the loss of BMD, after controlling for the effects of age, body size and the VDR genotype. The eccentric trunk extensor torque had a significant positive effect on delta BMD in a dose-dependent manner. The effect of this torque was the greatest among all the muscle indices. The net effect of the trunk extensor torque on delta BMD was greater than that of the VDR genotype. The trunk muscle strength was suggested to affect BMD change independently of age, body size, and the VDR genotype. Exercise programs to increase the strength of the trunk muscles would be beneficial for the prevention of osteoporosis regardless of

  11. Effect of noise reducing components on nose landing gear stability for a mid-size aircraft coupled with vortex shedding and freeplay

    NASA Astrophysics Data System (ADS)

    Eret, Petr; Kennedy, John; Bennett, Gareth J.

    2015-10-01

    In the pursuit of quieter aircraft, significant effort has been dedicated to airframe noise identification and reduction. The landing gear is one of the main sources of airframe noise on approach. The addition of noise abatement technologies such as fairings or wheel hub caps is usually considered to be the simplest solution to reduce this noise. After touchdown, noise abatement components can potentially affect the inherently nonlinear and dynamically complex behaviour (shimmy) of landing gear. Moreover, fairings can influence the aerodynamic load on the system and interact with the mechanical freeplay in the torque link. This paper presents a numerical study of nose landing gear stability for a mid-size aircraft with low noise solutions, which are modelled by an increase of the relevant model structural parameters to address a hypothetical effect of additional fairings and wheel hub caps. The study shows that the wheel hub caps are not a threat to stability. A fairing has a destabilising effect due to the increased moment of inertia of the strut and a stabilising effect due to the increased torsional stiffness of the strut. As the torsional stiffness is dependent on the method of attachment, in situations where the fairing increases the torsional inertia with little increase to the torsional stiffness, a net destabilising effect can result. Alternatively, it is possible that for the case that if the fairing were to increase equally both the torsional stiffness and the moment of inertia of the strut, then their effects could be mutually negated. However, it has been found here that for small and simple fairings, typical of current landing gear noise abatement design, their implementation will not affect the dynamics and stability of the system in an operational range (Fz ≤ 50 000 N, V ≤ 100 m/s). This generalisation is strictly dependent on size and installation methods. The aerodynamic load, which would be influenced by the presence of fairings, was modelled

  12. Cooperative integrin/ITAM signaling in platelets enhances thrombus formation in vitro and in vivo

    PubMed Central

    Zhi, Huiying; Rauova, Lubica; Hayes, Vincent; Gao, Cunji; Boylan, Brian; Newman, Debra K.; McKenzie, Steven E.; Cooley, Brian C.; Poncz, Mortimer; Newman, Peter J.

    2013-01-01

    The integrin family is composed of a series of 24 αβ heterodimer transmembrane adhesion receptors that mediate cell-cell and cell-extracellular matrix interactions. Adaptor molecules bearing immunoreceptor tyrosine-based activation motifs (ITAMs) have recently been shown to cooperate with specific integrins to increase the efficiency of transmitting ligand-binding–induced signals into cells. In human platelets, Fc receptor γ-chain IIa (FcγRIIa) has been identified as an ITAM-bearing transmembrane receptor responsible for mediating “outside-in” signaling through αIIbβ3, the major adhesion receptor on the platelet surface. To explore the importance of FcγRIIa in thrombosis and hemostasis, we subjected FcγRIIa-negative and FcγRIIa-positive murine platelets to a number of well-accepted models of platelet function. Compared with their FcγRIIa-negative counterparts, FcγRIIa-positive platelets exhibited increased tyrosine phosphorylation of Syk and phospholipase Cγ2 and increased spreading upon interaction with immobilized fibrinogen, retracted a fibrin clot faster, and showed markedly enhanced thrombus formation when perfused over a collagen-coated flow chamber under conditions of arterial and venous shear. They also displayed increased thrombus formation and fibrin deposition in in vivo models of vascular injury. Taken together, these data establish FcγRIIa as a physiologically important functional conduit for αIIbβ3-mediated outside-in signaling, and suggest that modulating the activity of this novel integrin/ITAM pair might be effective in controlling thrombosis. PMID:23264598

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

    PubMed

    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. PMID:24634700

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

    PubMed

    Li, Wei; Tang, Xiaorong; Yi, Wenxiu; Li, Qiang; Ren, Lijie; Liu, Xiaohui; Chu, Chunjun; Ozaki, Yukio; Zhang, Jian; Zhu, Li

    2013-01-01

    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. PMID:24386454

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

    PubMed Central

    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.

    2014-01-01

    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. PMID:24634700

  16. Beetroot juice reduces infarct size and improves cardiac function following ischemia-reperfusion injury: Possible involvement of endogenous H2S.

    PubMed

    Salloum, Fadi N; Sturz, Gregory R; Yin, Chang; Rehman, Shabina; Hoke, Nicholas N; Kukreja, Rakesh C; Xi, Lei

    2015-05-01

    Ingestion of high dietary nitrate in the form of beetroot juice (BRJ) has been shown to exert antihypertensive effects in humans through increasing cyclic guanosine monophosphate (cGMP) levels. Since enhanced cGMP protects against myocardial ischemia-reperfusion (I/R) injury through upregulation of hydrogen sulfide (H2S), we tested the hypothesis that BRJ protects against I/R injury via H2S. Adult male CD-1 mice received either regular drinking water or those dissolved with BRJ powder (10 g/L, containing ∼ 0.7 mM nitrate). Seven days later, the hearts were explanted for molecular analyses. Subsets of mice were subjected to I/R injury by occlusion of the left coronary artery for 30 min and reperfusion for 24 h. A specific inhibitor of H2S producing enzyme--cystathionine-γ-lyase (CSE), DL-propargylglycine (PAG, 50 mg/kg) was given i.p. 30 min before ischemia. Myocardial infarct size was significantly reduced in BRJ-fed mice (15.8 ± 3.2%) versus controls (46.5 ± 3.5%, mean ± standard error [SE], n = 6/group, P < .05). PAG completely blocked the infarct-limiting effect of BRJ. Moreover, BRJ significantly preserved ventricular function following I/R. Myocardial levels of H2S and its putative protein target--vascular endothelial growth factor receptor 2 (VEGFR2) were significantly increased by BRJ intake, whereas CSE mRNA and protein content did not change. Interestingly, the BRJ-induced cardioprotection was not associated with elevated blood nitrate-nitrite levels following I/R nor induction of cardiac peroxiredoxin 5, a mitochondrial antioxidant enzyme previously linked to nitrate-induced cardioprotection. We conclude that BRJ ingestion protects against post-I/R myocardial infarction and ventricular dysfunction possibly through CSE-mediated endogenous H2S generation. BRJ could be a promising natural and inexpensive nutraceutical supplement to reduce cardiac I/R injury in patients. PMID:25361774

  17. Complex Perioperative Decision-Making: Liver Resection in a Patient with Extensive Superior Vena Cava/Right Atrial Thrombus and Superior Vena Cava Syndrome

    PubMed Central

    Lekowski, Robert W.

    2016-01-01

    The perioperative management of patients suffering from extensive superior vena cava (SVC) thrombus complicated by SVC syndrome presents unique challenges. The anesthesiologist needs to be prepared for possible thrombus dislodgement resulting in pulmonary embolism and also has to assess the need for fluid resuscitation given the dangers of massive intravenous fluid application via the upper extremities. We present our perioperative approach in management of a patient scheduled for right hepatectomy who was previously diagnosed with extensive SVC and right atrial (RA) thrombus complicated by SVC syndrome. PMID:26904303

  18. A Proton Beam Therapy System Dedicated to Spot-Scanning Increases Accuracy with Moving Tumors by Real-Time Imaging and Gating and Reduces Equipment Size

    PubMed Central

    Shimizu, Shinichi; Miyamoto, Naoki; Matsuura, Taeko; Fujii, Yusuke; Umezawa, Masumi; Umegaki, Kikuo; Hiramoto, Kazuo; Shirato, Hiroki

    2014-01-01

    Purpose A proton beam therapy (PBT) system has been designed which dedicates to spot-scanning and has a gating function employing the fluoroscopy-based real-time-imaging of internal fiducial markers near tumors. The dose distribution and treatment time of the newly designed real-time-image gated, spot-scanning proton beam therapy (RGPT) were compared with free-breathing spot-scanning proton beam therapy (FBPT) in a simulation. Materials and Methods In-house simulation tools and treatment planning system VQA (Hitachi, Ltd., Japan) were used for estimating the dose distribution and treatment time. Simulations were performed for 48 motion parameters (including 8 respiratory patterns and 6 initial breathing timings) on CT data from two patients, A and B, with hepatocellular carcinoma and with clinical target volumes 14.6 cc and 63.1 cc. The respiratory patterns were derived from the actual trajectory of internal fiducial markers taken in X-ray real-time tumor-tracking radiotherapy (RTRT). Results With FBPT, 9/48 motion parameters achieved the criteria of successful delivery for patient A and 0/48 for B. With RGPT 48/48 and 42/48 achieved the criteria. Compared with FBPT, the mean liver dose was smaller with RGPT with statistical significance (p<0.001); it decreased from 27% to 13% and 28% to 23% of the prescribed doses for patients A and B, respectively. The relative lengthening of treatment time to administer 3 Gy (RBE) was estimated to be 1.22 (RGPT/FBPT: 138 s/113 s) and 1.72 (207 s/120 s) for patients A and B, respectively. Conclusions This simulation study demonstrated that the RGPT was able to improve the dose distribution markedly for moving tumors without very large treatment time extension. The proton beam therapy system dedicated to spot-scanning with a gating function for real-time imaging increases accuracy with moving tumors and reduces the physical size, and subsequently the cost of the equipment as well as of the building housing the equipment. PMID

  19. Incidence of post myocardial infarction left ventricular thrombus formation in the era of primary percutaneous intervention and glycoprotein IIb/IIIa inhibitors. A prospective observational study

    PubMed Central

    Rehan, Arshad; Kanwar, Manpreet; Rosman, Howard; Ahmed, Sujood; Ali, Arshad; Gardin, Julius; Cohen, Gerald

    2006-01-01

    Background Before the widespread use of primary percutaneous coronary intervention (PCI) and glycoprotein IIb/IIIa inhibitors (GP IIb/IIIa) left ventricular (LV) thrombus formation had been reported to complicate up to 20% of acute myocardial infarctions (AMI). The incidence of LV thrombus formation with these treatment modalities is not well known. Methods 92 consecutive patients with ST-elevation AMI treated with PCI and GP IIb/IIIa inhibitors underwent 2-D echocardiograms, with and without echo contrast agent, within 24–72 hours. Results Only 4/92 (4.3%) had an LV thrombus, representing a significantly lower incidence than that reported in the pre-PCI era. Use of contrast agents did not improve detection of LV thrombi in our study. Conclusion The incidence of LV thrombus formation after acute MI, in the current era of rapid reperfusion, is lower than what has been historically reported. PMID:16600036

  20. In Vivo Magnetization Transfer and Diffusion-Weighted Magnetic Resonance Imaging Detects Thrombus Composition in a Mouse Model of Deep Vein Thrombosis

    PubMed Central

    Saha, Prakash; Modarai, Bijan; Smith, Alberto; Botnar, René M.

    2014-01-01

    Background Deep vein thrombosis remains a major health problem necessitating accurate diagnosis. Thrombolysis is associated with significant morbidity and is effective only for the treatment of unorganized thrombus. We tested the feasibility of in vivo magnetization transfer (MT) and diffusion-weighted magnetic resonance imaging to detect thrombus organization in a murine model of deep vein thrombosis. Methods and Results Deep vein thrombosis was induced in the inferior vena cava of male BALB/C mice. Magnetic resonance imaging was performed at days 1, 7, 14, 21, and 28 after thrombus induction using MT, diffusion-weighted, inversion-recovery, and T1-mapping protocols. Delayed enhancement and T1 mapping were repeated 2 hours after injection of a fibrin contrast agent. Finally, excised thrombi were used for histology. We found that MT and diffusion-weighted imaging can detect histological changes associated with thrombus aging. MT rate (MTR) maps and percentage of MT rate (%MTR) allowed visualization and quantification of the thrombus protein content, respectively. The %MTR increased with thrombus organization and was significantly higher at days 14, 21, and 28 after thrombus induction (days 1, 7, 14, 21, 28: %MTR=2483±451, 2079±1210, 7029±2490, 10 295±4356, 32 994±25 449; Panova<0.05). There was a significant positive correlation between the %MTR and the histological protein content of the thrombus (r=0.70; P<0.05). The apparent diffusion coefficient was lower in erythrocyte-rich and collagen-rich thrombus (0.72±0.10 and 0.69±0.05 [×10−3 mm2/s]). Thrombus at days 7 and 14 had the highest apparent diffusion coefficient values (0.95±0.09 and 1.10±0.18 [×10−3 mm2/s]). Conclusions MT and diffusion-weighted magnetic resonance imaging sequences are promising for the staging of thrombus composition and could be useful in guiding medical intervention. PMID:23564561

  1. [Outcome of Resection of Inferior Vena Cava Superior to the Renal Vein in Renal Cell Carcinoma with Vena Caval Tumor Thrombus].

    PubMed

    Kashima, Soki; Narita, Shintaro; Saito, Mitsuru; Takahashi, Makoto; Maita, Shinya; Tsuruta, Hiroshi; Numakura, Kazuyuki; Maeno, Atsushi; Inoue, Takamitsu; Tsuchiya, Norihiko; Satoh, Shigeru; Yamamoto, Hiroshi; Yamamoto, Yuzo; Habuchi, Tomonori

    2016-06-01

    Surgical management with radical nephrectomy and thrombectomy has often been performed in renal cell carcinoma (RCC) with tumor thrombus infiltrating the inferior vena cava (IVC). We retrospectively reviewed the outcomes of IVC resection without venous reconstruction in patients with RCC and IVC thrombus at our institution. Eight patients with right RCC underwent radical nephrectomy and IVC resection superior to the level of the renal vein without venous reconstruction from August 2005 to February 2015. Thoracotomy, liver mobilization, and extracorporeal circulation were performed based on the IVC thrombus level. We assessed surgical outcomes, perioperative complications, and survival. At presentation, four patients had level IIIa IVC thrombus, three had level IIIb IVC thrombus, and one had level IV IVC thrombus. Perioperative imaging showed that three of the four patients who underwent neoadjuvant molecular targeting therapy achieved down-staging of the tumor thrombus level. The median operative time was 406 min, and the median estimated blood loss was 3,135 ml. With regard to IVC resectionassociated perioperative complications, one patient needed extracorporeal circulation with IVC ligation and Pringle maneuver owing to low blood pressure. Another patient underwent temporary hemodialysis for 8 days after surgery. There were no perioperative deaths, and none of the patients required permanent hemodialysis. Three patients survived the mean observation period of 25 months, including one patient with no recurrence. Three patients achieved long-term survival of more than 2 years. IVC resection without venous reconstruction may be a feasible option for patients with RCC and IVC tumor thrombus. Further study is needed to determine the most appropriate candidates for this procedure. PMID:27452491

  2. Free-floating thrombus of the carotid artery with a homozygous methylenetetrahydrofolate reductase gene mutation: a case report.

    PubMed

    Colak, Necmettin; Nazli, Yunus; Kosehan, Dilek; Alpay, Mehmet Fatih; Cakir, Omer

    2013-02-01

    Free-floating thrombus (FFT) of the carotid artery is a rare condition of currently unknown etiology. We describe a symptomatic patient with an FFT in the left common carotid artery. A duplex ultrasonography scan showed the presence of a mobile floating thrombus moving in cyclical motion with the cardiac cycles in the left common carotid artery. During emergency surgery, an FFT was seen at this location and removed. No underlying wall defect was seen at the time of surgery. In a genetic screening test, TT homozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T genetic polymorphisms was detected. The patient recovered uneventfully, with no neurogical events. Lifelong anticoagulant therapy was recommended. An aggressive surgical approach is recommended in the patient to prevent embolic episodes. PMID:22101856

  3. Thrombus formation patterns in the HeartMate II ventricular assist device: clinical observations can be predicted by numerical simulations.

    PubMed

    Chiu, Wei-Che; Slepian, Marvin J; Bluestein, Danny

    2014-01-01

    Postimplant device thrombosis remains a life-threatening complication and limitation of continuous-flow ventricular assist devices (VADs). Using advanced computational fluid dynamic (CFD) simulations, we successfully depicted various flow patterns, recirculation zones, and stagnant platelet trajectories which promote thrombus formation and observed that they matched actual thrombus formation patterns observed in Thoratec HeartMate II VADs explanted from patients with pump thrombosis. Previously, these small eddies could not be captured by either digital particle image velocimetry or CFD due to insufficient resolution. Our study successfully demonstrated the potential capability of advanced CFD to be adopted for device optimization, leading to enhanced safety and efficacy of VADs for long-term destination therapy. PMID:24399065

  4. Massive renal urothelial carcinoma with renal vein tumor thrombus, pancreatic infiltration and adrenal metastasis: A case report

    PubMed Central

    Li, Tao; Gao, Liang; Wu, Weilu; Chen, Peng; Bu, Siyuan; Wei, Qiang; Yang, Lu

    2016-01-01

    A 49-year-old female patient presented with a massive left renal tumor, recurrent left flank pain and gross hematuria. The tumor was accompanied by a renal vein tumor thrombus, pancreatic infiltration and a solitary adrenal metastasis. Radical nephrectomy, distal pancreatectomy, ipsilateral adrenalectomy and splenectomy were performed. Histopathological examination suggested high-grade urothelial carcinoma (UC); however, tumor recurrence and multiple metastases were detected only 3 months after the surgery, and the patient succumbed during follow-up 1 month later. To the best of our knowledge, this is the first case of renal UC of such advanced stage with renal vein tumor thrombus, pancreatic infiltration and a solitary adrenal metastasis. PMID:27446406

  5. ANCA-negative eosinophilic granulomatosis with polyangitis (EGPA) manifesting as a large intracardiac thrombus and glomerulonephritis with angionecrosis.

    PubMed

    Saito, Yuichi; Okada, Sho; Funabashi, Nobusada; Kobayashi, Yoshio

    2016-01-01

    A 59-year-old woman with a history of bronchial asthma presented with a prolonged fever and eosinophilia. There was transient proteinuria and troponin level was elevated. Antineutrophil cytoplasmic antibody was negative and she did not fulfil criteria for eosinophilic granulomatosis with polyangitis (EGPA). Echocardiography showed a large apical mass in the left ventricle, but there was no systolic dysfunction, local asynergy or ventricular remodelling. On MRI, apical mass was compatible with a thrombus and endocardial region was diffusely damaged. Loeffler endocarditis-like cardiac manifestation led to meticulous examination, which found no aetiology for eosinophilia. Finally, renal biopsy revealed eosinophil infiltration and glomerular angionecrosis, confirming as EGPA. This case highlights the isolated large cardiac thrombus as a rare presenting sign for EGPA and underscores current complicated strategy to diagnose EGPA. Of note, this clinical challenge was mostly caused by inchoate comprehension of hypereosinophilia-related disorders. PMID:27591039

  6. Increased Epicardial Adipose Tissue Thickness is Associated With Angiographic Thrombus Burden in the Patients With Non-ST-Segment Elevation Myocardial Infarction.

    PubMed

    Bakirci, Eftal Murat; Degirmenci, Husnu; Duman, Hakan; Inci, Sinan; Hamur, Hikmet; Buyuklu, Mutlu; Ceyhun, Gokhan; Topal, Ergun

    2015-10-01

    We aimed to evaluate the relation among epicardial adipose tissue (EAT) thickness, angiographic presence of thrombus, and the no-reflow in the patients with non-ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. The study population consisted of 229 patients. The EAT thickness and neutrophil to lymphocyte ratio (NLR) were significantly higher in the patients with coronary thrombus than in those without coronary thrombus (6.1 ± 1.1 vs 5.1 ± 1.3 mm, P < .001 and 3.4 ± 0.9 vs 2.5 ± 0.7, P < .001, respectively) and in the patients with no-reflow compared to patients with reflow. The EAT thickness was found to be correlated positively with the degree of the thrombus burden, NLR, and waist circumference and negatively with high-density lipoprotein cholesterol. Multivariate logistic regression analysis demonstrated that EAT thickness and NLR independently predicted coronary thrombus formation and no-reflow. We have suggested that EAT can play an important role in the pathophysiology of coronary thrombus formation and the no-reflow. PMID:25381157

  7. Vascular Smooth Muscle Cells Stimulate Platelets and Facilitate Thrombus Formation through Platelet CLEC-2: Implications in Atherothrombosis

    PubMed Central

    Inoue, Osamu; Hokamura, Kazuya; Shirai, Toshiaki; Osada, Makoto; Tsukiji, Nagaharu; Hatakeyama, Kinta; Umemura, Kazuo; Asada, Yujiro; Suzuki-Inoue, Katsue; Ozaki, Yukio

    2015-01-01

    The platelet receptor CLEC-2 is involved in thrombosis/hemostasis, but its ligand, podoplanin, is expressed only in advanced atherosclerotic lesions. We investigated CLEC-2 ligands in vessel walls. Recombinant CLEC-2 bound to early atherosclerotic lesions and normal arterial walls, co-localizing with vascular smooth muscle cells (VSMCs). Flow cytometry and immunocytochemistry showed that recombinant CLEC-2, but not an anti-podoplanin antibody, bound to VSMCs, suggesting that CLEC-2 ligands other than podoplanin are present in VSMCs. VSMCs stimulated platelet granule release and supported thrombus formation under flow, dependent on CLEC-2. The time to occlusion in a FeCl3-induced animal thrombosis model was significantly prolonged in the absence of CLEC-2. Because the internal elastic lamina was lacerated in our FeCl3-induced model, we assume that the interaction between CLEC-2 and its ligands in VSMCs induces thrombus formation. Protein arrays and Biacore analysis were used to identify S100A13 as a CLEC-2 ligand in VSMCs. However, S100A13 is not responsible for the above-described VSMC-induced platelet activation, because S100A13 is not expressed on the surface of normal VSMCs. S100A13 was released upon oxidative stress and expressed in the luminal area of atherosclerotic lesions. Suspended S100A13 did not activate platelets, but immobilized S100A13 significantly increased thrombus formation on collagen-coated surfaces. Taken together, we proposed that VSMCs stimulate platelets through CLEC-2, possibly leading to thrombus formation after plaque erosion and stent implantation, where VSMCs are exposed to blood flow. Furthermore, we identified S100A13 as one of the ligands on VSMCs. PMID:26418160

  8. Differentiation of cardiac thrombus from cardiac tumor combining cardiac MRI and 18F-FDG-PET/CT Imaging.

    PubMed

    Rinuncini, Massimo; Zuin, Marco; Scaranello, Fiorenzo; Fejzo, Majlinda; Rampin, Lucia; Rubello, Domenico; Faggian, Giuseppe; Roncon, Loris

    2016-06-01

    Radiological differentiation of an unknown cardiac masse is often a challenging issue. 18F-FDG-PET/CT imaging was performed to evaluate a left ventricle mass visualized on transthoracic echocardiogram (TTE) and cardiac magnetic resonance (CMR) in a patient with an history of ischemic heart disease. The metabolically inert area on the PET/CT, corresponding to the relatively homogenous hypodensity in the LV, was thought to represent an old organized LV thrombus. Histopathological examination confirmed the imaging diagnosis. PMID:27038712

  9. Thrombembolic occlusion of crural arteries following transcatheter aortic valve implantation--successful endovascular recanalization using a thrombus aspiration device.

    PubMed

    Malyar, Nasser M; Kaleschke, Gerrit; Reinecke, Holger

    2012-05-01

    Transcatheter aortic valve implantation (TAVI) has become an increasingly used alternative to conventional surgical valve replacement in patients with severe aortic valve stenosis (AS) and high operative risk. We here describe a case of a TAVI performed in local anesthesia causing intraprocedural thromboembolic occlusion of non-stenotic crural arteries and its immediate successful therapeutic management by means of endovascular recanalization using a thrombus aspiration device. PMID:22565625

  10. Vascular Smooth Muscle Cells Stimulate Platelets and Facilitate Thrombus Formation through Platelet CLEC-2: Implications in Atherothrombosis.

    PubMed

    Inoue, Osamu; Hokamura, Kazuya; Shirai, Toshiaki; Osada, Makoto; Tsukiji, Nagaharu; Hatakeyama, Kinta; Umemura, Kazuo; Asada, Yujiro; Suzuki-Inoue, Katsue; Ozaki, Yukio

    2015-01-01

    The platelet receptor CLEC-2 is involved in thrombosis/hemostasis, but its ligand, podoplanin, is expressed only in advanced atherosclerotic lesions. We investigated CLEC-2 ligands in vessel walls. Recombinant CLEC-2 bound to early atherosclerotic lesions and normal arterial walls, co-localizing with vascular smooth muscle cells (VSMCs). Flow cytometry and immunocytochemistry showed that recombinant CLEC-2, but not an anti-podoplanin antibody, bound to VSMCs, suggesting that CLEC-2 ligands other than podoplanin are present in VSMCs. VSMCs stimulated platelet granule release and supported thrombus formation under flow, dependent on CLEC-2. The time to occlusion in a FeCl3-induced animal thrombosis model was significantly prolonged in the absence of CLEC-2. Because the internal elastic lamina was lacerated in our FeCl3-induced model, we assume that the interaction between CLEC-2 and its ligands in VSMCs induces thrombus formation. Protein arrays and Biacore analysis were used to identify S100A13 as a CLEC-2 ligand in VSMCs. However, S100A13 is not responsible for the above-described VSMC-induced platelet activation, because S100A13 is not expressed on the surface of normal VSMCs. S100A13 was released upon oxidative stress and expressed in the luminal area of atherosclerotic lesions. Suspended S100A13 did not activate platelets, but immobilized S100A13 significantly increased thrombus formation on collagen-coated surfaces. Taken together, we proposed that VSMCs stimulate platelets through CLEC-2, possibly leading to thrombus formation after plaque erosion and stent implantation, where VSMCs are exposed to blood flow. Furthermore, we identified S100A13 as one of the ligands on VSMCs. PMID:26418160

  11. A Floating Thrombus Anchored at the Proximal Anastomosis of a Woven Thoracic Graft Mimicking a Genuine Aortic Dissection.

    PubMed

    Li, Bin; Liu, Bing; Fu, Yijun; Bondarenko, Olexandr; Verdant, Alain; Rochette-Drouin, Olivier; Lin, Jing; Bourget, Jean-Michel; Guzman, Randolph; Wang, Lu; Zhang, Ze; Douville, Yvan; Germain, Lucie; Jing, Zaiping; Guidoin, Robert

    2015-01-01

    An aortoesophageal fistula following surgery for a ruptured 6.6-cm thoracic aneurysm in a 69-year-old female was repaired using a 34-mm woven prosthetic graft. A follow-up computed tomography (CT) scan at 10 days postoperatively revealed a dissection-like picture in the region of the graft, which was treated conservatively. The patient eventually died from sepsis and multiorgan failure. At autopsy, the graft was retrieved in situ and studied by detailed gross, microscopy, and scanning electron microscopy (SEM) examination. Gross observation confirmed that the dissection resulted from the rolling of the internal capsule downstream. A massive thrombus anchored at the proximal anastomosis and held by a narrow head was also noted. The thrombus demonstrated reorganization in the area of the anastomosis, with a false lumen in its distal half. The reminder of the thrombus consisted of layered fibrin. After gross examination, the fabric graft was found to be flawless. Additional detailed studies were also done using microscopy, SEM, and gross examination. PMID:26756557

  12. Relative permittivity measurement during the thrombus formation process using the dielectric relaxation method for various hematocrit values.

    PubMed

    Asakura, Yuta; Sapkota, Achyut; Maruyama, Osamu; Kosaka, Ryo; Yamane, Takashi; Takei, Masahiro

    2015-12-01

    The relative permittivity ε' and the dielectric loss ε″ for various hematocrit values H for static bovine blood condition have been measured using the dielectric relaxation method to detect thrombosis in real time. The suitable measurement frequency f m ranged within 60 kHz to 1 MHz, and the relaxation frequency of red blood cells (RBCs) f rc was observed to be 2 MHz. In the f m, the temporal change of normalized ε' exhibited a minimum (called as bottom point). The bottom point was observed to be exponentially shortened as H increased. This characteristic of the ε'* minimum is discussed from three viewpoints: during fibrin formation, direct thrombus formation, and rouleaux formation processes. ε'* during the fibrin formation process decreased over time, irrespective of f. However, ε'* in f m during the direct thrombus formation process and during the aggregation formation process increased immediately and rapidly over time. Therefore, the ε'* bottom point in f m might be the indication of micrometer-scale thrombus formation by RBC aggregation due to fibrin formation. PMID:26058831

  13. A Case Report: An Acute Thrombus in the Femoral Artery following Total Hip Arthroplasty

    PubMed Central

    GBS, Varun; N, Muralidhar; Bharathidasan, Kavya

    2016-01-01

    Introduction: Vascular complications post-operative to a total hip arthroplasty are a very rare phenomenon. Only a few isolated cases have been reported to date. Diagnosis of such a case in a timely manner so as to preserve the limb is also difficult due to the subtle signs with which the patient presents. We report a case of complete occlusion of the common femoral artery following total hip arthroplasty due to acute thrombus formation. Case Presentation: A 56 year old Indian male patient underwent a cemented total hip replacement. Three hours post-operatively, the patient’s left lower limb was found to be pale and pulseless. Angiography showed complete occlusion of the left common femoral artery. Thrombectomy was carried out immediately and the patient recovered well. Conclusion: Vascular injuries are highly unusual findings following a total hip arthroplasty. Careful pre-operative and immediate post-operative monitoring of the patient is essential. Signs such as limb ischemia, absence of pulses, etc. must be recognized as early as possible and the necessary investigations and procedures should be carried out without any delay. PMID:27299128

  14. Symptomatic Patients with Intraluminal Carotid Thrombus: Outcome with a Strategy of Initial Anticoagulation

    PubMed Central

    Vellimana, Ananth K.; Kadkhodayan, Yasha; Rich, Keith M.; Cross, Dewitte T.; Moran, Christopher J.; Zazulia, Allyson R.; Lee, Jin-Moo; Chicoine, Michael R.; Dacey, Ralph G.; Derdeyn, Colin P.; Zipfel, Gregory J.

    2013-01-01

    Background Optimal treatment for patients with symptomatic intraluminal carotid thrombus (ICT) remains poorly defined. Methods We performed a retrospective chart review of patients presenting to our institution between 2001 and 2011 with symptomatic ICT. Results Twenty-four patients (16 males, 8 females) with ICT presented with ischemic stroke (n=18) or TIA (n=6). All were treated initially with anticoagulation ± antiplatelet drugs. Eight of these patients had no or mild carotid stenosis on initial angiography and were treated with medical management alone. The remaining 16 patients had moderate or severe carotid stenosis on initial angiography. Of these, 10 underwent delayed revascularization (endarterectomy, n=8; angioplasty and stenting, n=2), 2 refused revascularization, and 4 were treated with medical therapy alone. One patient had multiple TIAs despite medical therapy and eventually underwent CEA; the remaining 23 patients had no TIAs. No patient suffered ischemic or hemorrhagic stroke while on anticoagulation, during the perioperative period or in long-term follow up; one patient died of an unrelated condition (mean follow-up = 16.4 months). Conclusion Our results suggest that initial anticoagulation of symptomatic ICT results in a low rate of recurrent ischemic events and that carotid revascularization, if indicated, can be safely performed in a delayed manner. PMID:23061393

  15. Coupled Hemodynamic-Biochemical Modeling of Thrombus Formation in Infarcted Left Ventricles

    NASA Astrophysics Data System (ADS)

    Seo, Jung Hee; Vedula, Vijay; George, Richard; Mittal, Rajat

    2013-11-01

    Patients with heart failure (HF) and left ventricular (LV) systolic dysfunction have higher rates of thromboembolic events including embolic stroke and peripheral arterial thrombi. A common cause of arterial emboli in HF patients is myocardial infarction (MI) and subsequent left ventricular thrombus (LVT) formation. Stagnation of blood and endocardial injury are hypothesized to promote the development of LVT. The identification of high risk patients and the pharmacologic prevention of LVT formation are the keys to preventing embolic events. Stratification of patients at risk for LVT formation is currently limited, and primarily based on global assessment of ventricular function and image based assessment of ventricular wall motion. In this study, we explore a method to predict LVT risk using a multi-physics computational model. The blood flow in the left ventricle is simulated by solving the incompressible Navier-Stokes equation using an immersed boundary method and this is coupled to a convection-diffusion-reaction equation based model of platelet activation and coagulation. The results are then correlated with the other hemodynamic metrics such as wall shear stress and residence time to develop quantitative metrics for the LVT risk prediction. Supported by NSF CDI-Type II grant IOS-1124804, Computational resource by XSEDE NSF grant TG-CTS100002.

  16. Transarterial chemoembolization combined with sorafenib for the treatment of hepatocellular carcinoma with hepatic vein tumor thrombus

    PubMed Central

    Zhang, Yong-Fa; Wei, Wei; Wang, Jia-Hong; Xu, Li; Jian, Pei-En; Xiao, Cheng-Zuo; Zhong, Xiao-Ping; Shi, Ming; Guo, Rong-Ping

    2016-01-01

    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. PMID:27471398

  17. Management of Primitive Neuroectodermal Tumor of the Kidney with Inferior Vena Cava Thrombus

    PubMed Central

    Gupta, Sahil; Majumder, Kaustav; Chahal, Anurag; Saini, Ashish K.; Gupta, Arjun

    2016-01-01

    Primitive neuroectodermal tumors (PNET) are an aggressive group of small round cell tumors usually arising in the nervous system and affecting children. They have a tendency for local invasion, distant spread and formation of tumor thrombi. The kidney is a rare primary location for these tumors. Outcomes are frequently poor due to late diagnosis (Wilms tumor is a more common tumor in this population) and early spread. Immunohistochemistry is invaluable in making the diagnosis of PNET. We report a case of a primary renal PNET with extensive tumor thrombus into the inferior vena cava, and lung metastasis in a pediatric patient, and its successful management. Our 14-year-old patient with renal PNET was managed with radical nephrectomy, thrombectomy and chemotherapy and remains disease free to date. The diagnosis of renal PNETs should be considered in young adult patients who present with aggressive renal masses at initial presentations. Despite its aggressive nature, good outcomes can be achieved by a multimodality therapeutic strategy. PMID:26989372

  18. [A case of surgical resection for liver metastasis of gastric cancer with portal vein tumor thrombus].

    PubMed

    Hata, Tomoki; Wada, Hiroshi; Tomimaru, Yoshito; Tomokuni, Akira; Hama, Naoki; Kawamoto, Koichi; Kobayashi, Shogo; Asaoka, Tadafumi; Marubashi, Shigeru; Eguchi, Hidetoshi; Umeshita, Koji; Takiguchi, Shuji; Mori, Masaki; Doki, Yuichiro; Nagano, Hiroaki

    2014-11-01

    A 58-year-old man presented with anorexia and weight loss in April 2010. Endoscopic examination revealed a type 3 tumor extending from the gastric cardia to the antrum. Preoperative imaging showed liver metastasis (S8; 2 cm) and direct invasion of the cancer into the pancreas. We administered 4 courses of chemotherapy (DCS) for the unresectable tumor; the impact of the therapy was partial response (PR). We performed total gastrectomy, D2 dissection, splenectomy, distal pancreatectomy, and partial hepatectomy (S8) in April 2011. The patient was treated with 8 courses of adjuvant chemotherapy with S-1. In April 2012, abdominal computed tomography (CT) revealed a solitary recurrent lesion in the liver (S2). After 7 courses of chemotherapy(weekly paclitaxel), abdominal CT and magnetic resonance imaging (MRI) revealed a tumor thrombus in the portal vein extending from P2 to the umbilical portion (UP). We performed left hepatectomy and cholecystectomy due to the absence of new lesions. Histopathological findings revealed that the poorly differentiated adenocarcinoma had metastasized to the liver. Abdominal CT revealed the presence of multiple recurrent metastases in the liver, 4 months after the surgery. The patient died 27 months after the initial surgery and 7 months after the last operation. PMID:25731448

  19. Quantification of volume, mass, and density of thrombus formation using brightfield and differential interference contrast microscopy

    NASA Astrophysics Data System (ADS)

    Baker-Groberg, Sandra M.; Phillips, Kevin G.; McCarty, Owen J. T.

    2013-01-01

    Flow chamber assays, in which blood is perfused over surfaces of immobilized extracellular matrix proteins, are used to investigate the formation of platelet thrombi and aggregates under shear flow conditions. Elucidating the dynamic response of thrombi/aggregate formation to different coagulation pathway perturbations in vitro has been used to develop an understanding of normal and pathological cardiovascular states. Current microscopy techniques, such as differential interference contrast (DIC) or fluorescent confocal imaging, respectively, do not provide a simple, quantitative understanding of the basic physical features (volume, mass, and density) of platelet thrombi/aggregate structures. The use of two label-free imaging techniques applied, for the first time, to platelet aggregate and thrombus formation are introduced: noninterferometric quantitative phase microscopy, to determine mass, and Hilbert transform DIC microscopy, to perform volume measurements. Together these techniques enable a quantitative biophysical characterization of platelet aggregates and thrombi formed on three surfaces: fibrillar collagen, fibrillar collagen +0.1 nM tissue factor (TF), and fibrillar collagen +1 nM TF. It is demonstrated that label-free imaging techniques provide quantitative insight into the mechanisms by which thrombi and aggregates are formed in response to exposure to different combinations of procoagulant agonists under shear flow.

  20. Quantification of volume, mass, and density of thrombus formation using brightfield and differential interference contrast microscopy.

    PubMed

    Baker-Groberg, Sandra M; Phillips, Kevin G; McCarty, Owen J T

    2013-01-01

    Flow chamber assays, in which blood is perfused over surfaces of immobilized extracellular matrix proteins, are used to investigate the formation of platelet thrombi and aggregates under shear flow conditions. Elucidating the dynamic response of thrombi/aggregate formation to different coagulation pathway perturbations in vitro has been used to develop an understanding of normal and pathological cardiovascular states. Current microscopy techniques, such as differential interference contrast (DIC) or fluorescent confocal imaging, respectively, do not provide a simple, quantitative understanding of the basic physical features (volume, mass, and density) of platelet thrombi/aggregate structures. The use of two label-free imaging techniques applied, for the first time, to platelet aggregate and thrombus formation are introduced: noninterferometric quantitative phase microscopy, to determine mass, and Hilbert transform DIC microscopy, to perform volume measurements. Together these techniques enable a quantitative biophysical characterization of platelet aggregates and thrombi formed on three surfaces: fibrillar collagen, fibrillar collagen +0.1  nM tissue factor (TF), and fibrillar collagen +1  nM TF. It is demonstrated that label-free imaging techniques provide quantitative insight into the mechanisms by which thrombi and aggregates are formed in response to exposure to different combinations of procoagulant agonists under shear flow. PMID:23348747

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

    SciTech Connect

    Hong, Theodore S.; Bosch, Walter R.; Krishnan, Sunil; Kim, Tae K.; Mamon, Harvey J.; Ben-Josef, Edgar; Seong, Jinsil; Haddock, Michael G.; Cheng, Jason C.; Feng, Mary U.; Stephans, Kevin L.; Roberge, David; 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 planning

  2. Sizing of crimped Dacron grafts.

    PubMed

    Reid, J D; Sladen, J G

    1992-05-01

    The aim of this study was to correlate the stated size of Dacron grafts (Microvel) with their actual internal diameter and to compare this with measurements by ultrasound in the early postoperative period. Grafts of stated diameters of 7, 8, 9, and 10 mm were studied. Grafts were measured by graded probes and by measuring the width of the longitudinally opened graft and calculating the diameter. Each graft accepted a probe 1 mm larger than its stated size very easily and 2 mm greater when stretched. By open measurement, the grafts were 1.3 to 1.8 mm greater than their stated diameter without stretching. Twenty grafts were studied by duplex ultrasound for diameter and peak systolic velocity within 3 months of implantation. The grafts were 12% larger than their stated graft size. Some of the larger grafts showed low velocity and wall thrombus. We conclude that Microvel grafts are larger than their stated diameter. The same size discrepancy was seen in in vitro measurements of Vascutek (Dacron) grafts but not in polytetrafluoroethylene (Gortex) grafts. Since flow velocity is related to the diameter of the graft, this information should be useful when choosing the diameter of a prosthetic vascular graft. PMID:1533494

  3. Can a Sex-Biased Human Demography Account for the Reduced Effective Population Size of Chromosome X in Non-Africans?

    PubMed Central

    Keinan, Alon; Reich, David

    2010-01-01

    Sex-biased demographic events can result in asymmetries in female and male effective population size that can lead to different patterns of genetic variation on chromosome X than are expected based on the patterns on the autosomes. Previous studies point to a period around the time of the dispersal of anatomically modern humans out of Africa when chromosome X experienced a significant reduction in effective population size relative to the autosomes. Here, we explore whether a sex-biased demographic history could explain these observations. We use coalescent simulations to show that a model of primarily male migration during the out-of-Africa dispersal can produce the striking patterns that are observed when comparing patterns of genetic variation on the autosomes and chromosome X. The model involves a history in which after the founder population of non-Africans lost much of its genetic diversity, subsequent mostly male gene flow from an African source brought new diversity into the population. We also explore two additional models, one of sex-biased generation time and one of a substructured population during the dispersal out of Africa with primarily female migration among demes. These latter models cannot account for the magnitude of the observed reduction in chromosome X effective population size, although it is plausible that they played a more minor role in producing the striking chromosome X/autosome patterns. PMID:20453016

  4. Thrombus Aspirated from Patients with ST-Elevation Myocardial Infarction: Association between 3-Nitrotyrosine and Inflammatory Markers - Insights from ARTERIA Study

    PubMed Central

    Dominguez-Rodriguez, Alberto; Abreu-Gonzalez, Pedro; Consuegra-Sanchez, Luciano; Avanzas, Pablo; Sanchez-Grande, Alejandro; Conesa-Zamora, Pablo

    2016-01-01

    Recent studies have demonstrated that inflammatory cells are a component that plays a role in thrombus formation in ST-elevation myocardial infarction (STEMI). 3-nitrotyrosine (3-NO2-Tyr), a specific marker for protein modification by nitric oxide-derived oxidants, is increased in human atherosclerotic lesions. The purpose of this study was to determine the possible association of inflammatory markers of coronary thrombi with nitroxidative stress. Intracoronary thrombus (n=51) and blood from the systemic circulation were obtained by thromboaspiration in 138 consecutive STEMI patients presenting for primary percutaneous coronary intervention (PCI). Each blood and intracoronary thrombus were measured simultaneously the following biomarkers: C-reactive protein (CRP), 3-NO2-Tyr, soluble CD 40 ligand (sCD40L), vascular cellular adhesion molecule-1 (VCAM-1) and haemoglobin content (only in coronary thrombus). Time delay in minutes from symptom onset to PCI was 244 ± 324. Serum CRP was positively correlated to CRP content in the thrombus (r= 0.395; p = 0.02) and serum sCD40L was negatively correlated to sCD40L in the thrombus (r= -0.394; p = 0.02). Patients were divided into tertiles according to thrombi 3-NO2-Tyr concentration: 1sttertile (<0.146ng/mg), 2ndtertile (0.146-0.485ng/mg) and 3rdtertile (>0.485ng/mg). Thus, thrombus in the highest tertile had significantly higher levels of CRP (p=0.002), VCAM-1 (p=0.003) and haemoglobin (p=0.002). In conclusion, the present study demonstrated that coronary thrombi with higher levels of 3-NO2-Tyr content often contain more inflammatory markers which could have a direct impact on the efficacy of drugs or devices used for coronary reperfusion. PMID:27429583

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

    PubMed Central

    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

    2016-01-01

    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 PMID:27165711

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

    PubMed

    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. PMID:27165711

  7. Thrombus Aspirated from Patients with ST-Elevation Myocardial Infarction: Association between 3-Nitrotyrosine and Inflammatory Markers - Insights from ARTERIA Study.

    PubMed

    Dominguez-Rodriguez, Alberto; Abreu-Gonzalez, Pedro; Consuegra-Sanchez, Luciano; Avanzas, Pablo; Sanchez-Grande, Alejandro; Conesa-Zamora, Pablo

    2016-01-01

    Recent studies have demonstrated that inflammatory cells are a component that plays a role in thrombus formation in ST-elevation myocardial infarction (STEMI). 3-nitrotyrosine (3-NO2-Tyr), a specific marker for protein modification by nitric oxide-derived oxidants, is increased in human atherosclerotic lesions. The purpose of this study was to determine the possible association of inflammatory markers of coronary thrombi with nitroxidative stress. Intracoronary thrombus (n=51) and blood from the systemic circulation were obtained by thromboaspiration in 138 consecutive STEMI patients presenting for primary percutaneous coronary intervention (PCI). Each blood and intracoronary thrombus were measured simultaneously the following biomarkers: C-reactive protein (CRP), 3-NO2-Tyr, soluble CD 40 ligand (sCD40L), vascular cellular adhesion molecule-1 (VCAM-1) and haemoglobin content (only in coronary thrombus). Time delay in minutes from symptom onset to PCI was 244 ± 324. Serum CRP was positively correlated to CRP content in the thrombus (r= 0.395; p = 0.02) and serum sCD40L was negatively correlated to sCD40L in the thrombus (r= -0.394; p = 0.02). Patients were divided into tertiles according to thrombi 3-NO2-Tyr concentration: 1(st)tertile (<0.146ng/mg), 2(nd)tertile (0.146-0.485ng/mg) and 3(rd)tertile (>0.485ng/mg). Thus, thrombus in the highest tertile had significantly higher levels of CRP (p=0.002), VCAM-1 (p=0.003) and haemoglobin (p=0.002). In conclusion, the present study demonstrated that coronary thrombi with higher levels of 3-NO2-Tyr content often contain more inflammatory markers which could have a direct impact on the efficacy of drugs or devices used for coronary reperfusion. PMID:27429583

  8. Bimodal Thrombus Imaging: Simultaneous PET/MR Imaging with a Fibrin-targeted Dual PET/MR Probe—Feasibility Study in Rat Model

    PubMed Central

    Uppal, Ritika; Catana, Ciprian; Ay, Ilknur; Benner, Thomas; Sorensen, A. Gregory

    2011-01-01

    Purpose: To image thrombus by using magnetic resonance (MR) imaging and positron emission tomography (PET) simultaneously in a rat arterial thrombus model with a dual PET/MR probe. Materials and Methods: Animal studies were approved by the institutional animal use committee. A dual PET/MR probe was synthesized by means of partial exchange of gadolinium for copper 64 (64Cu) in the fibrin-targeted MR probe EP-2104R. A preformed 25-mm thrombus was injected into the right internal carotid artery of a rat. Imaging was performed with a clinical 3.0-T MR imager with an MR-compatible human PET imager. Rats (n = 5) were imaged prior to and after systemic administration of the dual probe by using simultaneous PET/MR. The organ distribution of 64Cu and gadolinium was determined ex vivo (n = 8), 2 hours after injection by using well counting and inductively coupled plasma mass spectrometry, respectively. Signal intensity ratios (SIRs) between the thrombus-containing and contralateral vessel were computed from PET images and MR data before and after probe administration. Results: The dual probe was synthesized with greater than 98% radiochemical purity. Thrombus enhancement was observed in all five animals at both MR (SIR[postprobe]/SIR[preprobe] = 1.71 ± 0.35, P = .0053) and PET (SIR = 1.85 ± 0.48, P = .0087) after injection of the dual PET/MR probe. Ex vivo analysis at 2 hours after injection showed the highest 64Cu and gadolinium concentrations, after the excretory organs (kidney and liver), to be in the thrombus. Conclusion: A fibrin-targeted dual PET/MR probe enables simultaneous, direct MR and PET imaging of thrombus. © RSNA, 2010 PMID:21177389

  9. Winter grazing decreases the probability of fire-induced mortality of bunchgrasses and may reduce wildfire size: a response to Smith et al(this issue)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent commentary by Smith et al. (this issue) attempted to discount the findings of our study (Davies et al. this issue) by claiming that our study contained methodological errors and lacked the data necessary to support our conclusions, in particular that winter grazing may reduce the probabilit...

  10. Promotion of experimental thrombus formation by the procoagulant activity of breast cancer cells

    NASA Astrophysics Data System (ADS)

    Berny-Lang, M. A.; Aslan, J. E.; Tormoen, G. W.; Patel, I. A.; Bock, P. E.; Gruber, A.; McCarty, O. J. T.

    2011-02-01

    The routine observation of tumor emboli in the peripheral blood of patients with carcinomas raises questions about the clinical relevance of these circulating tumor cells. Thrombosis is a common clinical manifestation of cancer, and circulating tumor cells may play a pathogenetic role in this process. The presence of coagulation-associated molecules on cancer cells has been described, but the mechanisms by which circulating tumor cells augment or alter coagulation remains unclear. In this study we utilized suspensions of a metastatic adenocarcinoma cell line, MDA-MB-231, and a non-metastatic breast epithelial cell line, MCF-10A, as models of circulating tumor cells to determine the thromobogenic activity of these blood-foreign cells. In human plasma, both metastatic MDA-MB-231 cells and non-metastatic MCF-10A cells significantly enhanced clotting kinetics. The effect of MDA-MB-231 and MCF-10A cells on clotting times was cell number-dependent and inhibited by a neutralizing antibody to tissue factor (TF) as well as inhibitors of activated factor X and thrombin. Using fluorescence microscopy, we found that both MDA-MB-231 and MCF-10A cells supported the binding of fluorescently labeled thrombin. Furthermore, in a model of thrombus formation under pressure-driven flow, MDA-MB-231 and MCF-10A cells significantly decreased the time to occlusion. Our findings indicate that the presence of breast epithelial cells in blood can stimulate coagulation in a TF-dependent manner, suggesting that tumor cells that enter the circulation may promote the formation of occlusive thrombi under shear flow conditions.

  11. Hepatic resection or transarterial chemoembolization for hepatocellular carcinoma with portal vein tumor thrombus.

    PubMed

    Zheng, Ninggang; Wei, Xiaodong; Zhang, Dongzhi; Chai, Wenxiao; Che, Ming; Wang, Jiangye; Du, Binbin

    2016-06-01

    The role of hepatic resection in hepatocellular carcinoma (HCC) with accompanying portal vein tumor thrombus (PVTT) remains controversial. This study aimed to evaluate the surgical outcomes of hepatic resection compared with those of transarterial chemoembolization (TACE) in HCC patients. A retrospective study was conducted using the medical records of 230 HCC patients with portal vein invasion who underwent hepatic resection (96 patients) or TACE (134 patients). The baseline characteristics, tumor characteristics, clinicopathological parameters, and overall survival rates were compared between the 2 groups. The baseline and tumor characteristics were comparable between the hepatic resection and TACE groups. The overall complication rate was 35.4% in the hepatic resection group, which was significantly lower than that in the TACE group (73.0%, P <0.001). However, the serious complication rate (grade ≥3) in the hepatic resection group was 13.5%, which was significantly higher than that in the TACE group (P = 0.003). The cumulative overall survival rates at 1, 3, and 5 years in the hepatic resection group were 86.5%, 60.4%, and 33.3%, respectively. These rates were much higher than those in the TACE group (1-year: 77.6%; 3-year: 47.8%; and 5-year: 20.9%; P = 0.021). The long-term survival was notably better in the patients with types I and II PVTT than in the patients with types III and IV PVTT (P <0.05). The univariate and multivariate analyses indicated that types III and IV PVTT and TACE may have contributed to the poor overall survival following surgery. In HCC patients with PVTT and compensated liver function, hepatic resection is a safe and effective surgical protocol, particularly for patients with type I or II PVTT. PMID:27367992

  12. Intracardiac thrombus in Behçet's disease: four new cases and a comprehensive literature review.

    PubMed

    Aksu, Tolga; Tufekcioglu, Omac

    2015-07-01

    Behçet's disease (BD) is a multisystem inflammatory disorder. Intracardiac thrombus formation (ICTF) is an uncommon but important complication of BD. To highlight recent insights into this disease, we aimed to review ICTF and other systemic involvements associated with ICTF in BD. We conducted a comprehensive review of the relevant literature in MEDLINE and EMBASE from 1966 to 2014 to analyze cumulated data about ICTF in BD. We aimed to evaluate 93 cases of BD with ICT (group 1), four of which have been recently identified and have not been discussed in the relevant literature yet, and to compare the frequency of pulmonary, venous and arterial involvements in group 1 and general Behçet population (group 2). The right heart was the most common site of ICTF in group 1. Pulmonary involvement, venous involvement (especially venous thrombosis) and arterial involvement were more frequent in group 1 than in group 2 (56 vs. 0.7 %, 42 vs. 10 % and 38 vs. 0.8 %, respectively, p < 0.0001). The diagnosis of BD should be considered if a patient presents with a mass in the right-sided cardiac chambers, even in the absence of the characteristic clinical manifestations of the illness. This approach is particularly applicable if the patient is a young man from the Mediterranean basin or the Middle East. All Behçet patients with ICTF must be investigated with thoracic computed tomography for pulmonary and arterial involvements and lower extremity venous Doppler ultrasonography for venous thrombosis, regardless of whether they are symptomatic for these systems. PMID:25381640

  13. A chimeric platelet-targeted urokinase prodrug selectively blocks new thrombus formation

    PubMed Central

    Fuentes, Rudy E.; Zaitsev, Sergei; Ahn, Hyun Sook; Hayes, Vincent; Kowalska, M. Anna; Lambert, Michele P.; Wang, Yuhuan; Siegel, Donald L.; Bougie, Daniel W.; Aster, Richard H.; Myers, Daniel D.; Stepanova, Victoria; Cines, Douglas B.; Muzykantov, Vladimir R.; Poncz, Mortimer

    2015-01-01

    The use of fibrinolytic agents to prevent new thrombus formation is limited by an increased risk of bleeding due to lysis of hemostatic clots that prevent hemorrhage in damaged blood vessels. We sought to develop an agent that provides thromboprophylaxis without carrying a significant risk of causing systemic fibrinolysis or disrupting hemostatic clots. We previously showed that platelet (PLT) α granule–delivered urokinase plasminogen activator (uPA) is highly effective in preventing thrombosis, while being associated with little systemic fibrinolysis or bleeding. Here, we generated a chimeric prodrug composed of a single-chain version of the variable region of an anti-αIIbβ3 mAb fused to a thrombin-activatable, low-molecular-weight pro-uPA (PLT/uPA-T). PLT/uPA-T recognizes human αIIbβ3 on both quiescent and activated platelets and is enzymatically activated specifically by thrombin. We found that this prodrug binds tightly to human platelets even after gel filtration, has a prolonged half-life in mice transgenic for human αIIb compared with that of uPA-T, and prevents clot formation in a microfluidic system. Importantly, in two murine injury models, PLT/uPA-T did not lyse preexisting clots, even when administration was delayed by as little as 10 minutes, while it concurrently prevented the development of nascent thrombi. Thus, PLT/uPA-T represents the prototype of a platelet-targeted thromboprophylactic agent that selectively targets nascent over preexisting thrombi. PMID:26690701

  14. Promotion of experimental thrombus formation by the procoagulant activity of breast cancer cells

    PubMed Central

    Berny-Lang, MA; Aslan, JE; Tormoen, GW; Patel, IA; Bock, PE; Gruber, A

    2011-01-01

    The routine observation of tumor emboli in the peripheral blood of patients with carcinomas raises questions about the clinical relevance of these circulating tumor cells. Thrombosis is a common clinical manifestation of cancer and circulating tumor cells may play a pathogenetic role in this process. The presence of coagulation-associated molecules on cancer cells has been described, but the mechanisms by which circulating tumor cells augment or alter coagulation remains unclear. In this study we utilized suspensions of a metastatic adenocarcinoma cell line, MDA-MB-231, and a non-metastatic breast epithelial cell line, MCF-10A, as models of circulating tumor cells to determine the thromobogenic activity of these blood-foreign cells. In human plasma, both metastatic MDA-MB-231 cells and non-metastatic MCF-10A cells significantly enhanced clotting kinetics. The effect of MDA-MB-231 and MCF-10A cells on clotting times was cell number-dependent and inhibited by a neutralizing antibody to tissue factor (TF) as well as inhibitors of activated factor X and thrombin. Using fluorescence microscopy, we found that both MDA-MB-231 and MCF-10A cells supported the binding of fluorescently-labeled thrombin. Furthermore, in a model of thrombus formation under pressure-driven flow, MDA-MB-231 and MCF-10A cells significantly decreased the time to occlusion. Our findings indicate that the presence of breast epithelial cells in blood can stimulate coagulation in a TF-dependent manner, suggesting that tumor cells that enter the circulation may promote the formation of occlusive thrombi under shear flow conditions. PMID:21301066

  15. Hepatic resection or transarterial chemoembolization for hepatocellular carcinoma with portal vein tumor thrombus

    PubMed Central

    Zheng, Ninggang; Wei, Xiaodong; Zhang, Dongzhi; Chai, Wenxiao; Che, Ming; Wang, Jiangye; Du, Binbin

    2016-01-01

    Abstract The role of hepatic resection in hepatocellular carcinoma (HCC) with accompanying portal vein tumor thrombus (PVTT) remains controversial. This study aimed to evaluate the surgical outcomes of hepatic resection compared with those of transarterial chemoembolization (TACE) in HCC patients. A retrospective study was conducted using the medical records of 230 HCC patients with portal vein invasion who underwent hepatic resection (96 patients) or TACE (134 patients). The baseline characteristics, tumor characteristics, clinicopathological parameters, and overall survival rates were compared between the 2 groups. The baseline and tumor characteristics were comparable between the hepatic resection and TACE groups. The overall complication rate was 35.4% in the hepatic resection group, which was significantly lower than that in the TACE group (73.0%, P <0.001). However, the serious complication rate (grade ≥3) in the hepatic resection group was 13.5%, which was significantly higher than that in the TACE group (P = 0.003). The cumulative overall survival rates at 1, 3, and 5 years in the hepatic resection group were 86.5%, 60.4%, and 33.3%, respectively. These rates were much higher than those in the TACE group (1-year: 77.6%; 3-year: 47.8%; and 5-year: 20.9%; P = 0.021). The long-term survival was notably better in the patients with types I and II PVTT than in the patients with types III and IV PVTT (P <0.05). The univariate and multivariate analyses indicated that types III and IV PVTT and TACE may have contributed to the poor overall survival following surgery. In HCC patients with PVTT and compensated liver function, hepatic resection is a safe and effective surgical protocol, particularly for patients with type I or II PVTT. PMID:27367992

  16. Immobilization of bioactive plasmin reduces the thrombogenicity of metal surfaces.

    PubMed

    Wise, Steven G; Michael, Praveesuda L; Waterhouse, Anna; Santos, Miguel; Filipe, Elysse; Hung, Juichien; Kondyurin, Alexey; Bilek, Marcela M M; Ng, Martin K C

    2015-12-01

    Components of many vascular prostheses including endovascular stents, heart valves and ventricular assist devices are made using metal alloys. In these blood contacting applications, metallic devices promote blood clotting, which is managed clinically by profound platelet suppression and/or anticoagulation. Here it is proposed that the localized immobilization of bioactive plasmin, a critical mediator of blood clot stability, may attenuate metallic prosthesis-induced thrombus formation. Previously described approaches to covalently immobilize biomolecules on implantable materials have relied on complex chemical linker chemistry, increasing the possibility of toxic side effects and reducing bioactivity. We utilize a plasma deposited thin film platform to covalently immobilize biologically active plasmin on stainless steel substrates, including stents. A range of in vitro whole blood assays demonstrate striking reductions in thrombus formation. This approach has profound potential to improve the efficacy of a wide range of metallic vascular implants. PMID:26551872

  17. In situ capping for size control of monochalcogenides (ZnS, CdS, and SnS) nanocrystals produced by anaerobic metal-reducing bacteria

    SciTech Connect

    Jang, Gyoung Gug; Jacobs, Christopher B.; Ivanov, Ilia N.; Joshi, Pooran C.; Meyer, III, Harry M.; Kidder, Michelle; Armstrong, Beth L.; Datskos, Panos G.; Graham, David E.; Moon, Ji -Won

    2015-07-24

    Metal monochalcogenide quantum dot nanocrystals of ZnS, CdS and SnS were prepared by anaerobic, metal-reducing bacteria using in situ capping by oleic acid or oleylamine. Furthermore, the capping agent preferentially adsorbs on the surface of the nanocrystal, suppressing the growth process in the early stages, thus leading to production of nanocrystals with a diameter of less than 5 nm.

  18. In situ capping for size control of monochalcogenide (ZnS, CdS and SnS) nanocrystals produced by anaerobic metal-reducing bacteria

    NASA Astrophysics Data System (ADS)

    Gug Jang, Gyoung; Jacobs, Christopher B.; Ivanov, Ilia N.; Joshi, Pooran C.; Meyer, Harry M., III; Kidder, Michelle; Armstrong, Beth L.; Datskos, Panos G.; Graham, David E.; Moon, Ji-Won

    2015-08-01

    Metal monochalcogenide quantum dot nanocrystals of ZnS, CdS and SnS were prepared by anaerobic, metal-reducing bacteria using in situ capping by oleic acid or oleylamine. The capping agent preferentially adsorbs on the surface of the nanocrystal, suppressing the growth process in the early stages, thus leading to production of nanocrystals with a diameter of less than 5 nm.

  19. Inhibition of SA Node at Supine Position in Right Atrial Thrombus Complicating Behçet’s Disease – From Cardiac Surgical Point of View

    PubMed Central

    Hijazi, Emad Mohamed; Ibdah, Rasheed Khaled; Rawashdeh, Sukina Ismael; Saadeh, Abdullah Mahmoud; Al-Balas, Hamzeh Ibrahim

    2016-01-01

    Patient: Female, 27 Final Diagnosis: Right atrial thrombus compressing the sinoatrial node Symptoms: Dyspnea • cough and hemoptysis with supine bradycardia reaching 36/min and dizziness Medication: — Clinical Procedure: Cardiac surgical intervention removing the mechanical cause if conservative management failed can be done safely Specialty: Surgery Objective: Rare disease Background: Behçet’s disease (BD) is a chronic multi-systemic disease of unknown cause. Intra-cardiac thrombus (ICT) complicating BD is extremely rare. In general, cardiac manifestations in BD are associated with poor prognosis. Chest computed tomography (CT) scan and echocardiogram are excellent modalities for diagnosis and patient assessment. Cardiac surgical intervention can be done safely using an on-pump technique when medical management has failed. Case Report: We report on a case of a 27-year-old Jordanian woman diagnosed with BD who presented with dyspnea, cough, and hemoptysis, with supine bradycardia reaching 36 beats/minute and dizziness which disappear on sitting or standing position, and with heart rate reaching 76 beats/minute. Right atrial thrombus was identified using transthoracic echocardiogram and chest CT scan. After medical management failed, cardiac surgical intervention became an option and targeted extraction of the right atrial thrombus compressing the sinoatrial node (SA node). Conclusions: In BD, right atrial thrombus compressing the SA node is rare. If conservative management has failed, cardiac surgical intervention removing the mechanical cause can be done safely, either using on-pump with cross clamp or on-pump with beating heart technique. PMID:27311379

  20. A long-surviving case of gastric cancer with main portal vein tumor thrombus after surgical resection and postoperative S-1 therapy.

    PubMed

    Sato, Shinsuke; Nagai, Erina; Taki, Yusuke; Watanabe, Masaya; Takahashi, Michiro; Kyoden, Yusuke; Ohata, Ko; Kanemoto, Hideyuki; Oba, Noriyuki; Taku, Keisei; Suzuki, Makoto; Takagi, Masakazu

    2016-08-01

    Gastric cancer patients with main portal vein tumor thrombus usually have a short survival time, owing to its aggressive behavior. Herein, we report a long-surviving case of gastric cancer with main portal vein tumor thrombus. A 78-year-old man presenting with anorexia and body weight loss was diagnosed with gastric cancer. The patient was referred to our hospital for further examination and treatment. Endoscopy revealed a type 3 tumor (8.0 cm in length) in the body of the stomach. Biopsy led to the diagnosis of moderately differentiated adenocarcinoma. Enhanced computed tomography revealed a large tumor thrombus extending from the gastric coronary vein to the portal trunk. A total gastrectomy with lymphadenectomy, splenectomy, and thrombectomy was performed. Postoperative chemotherapy with S-1 was administered for 18 months. The patient died a natural death without recurrence at 49 postoperative months. To the best of our knowledge, the patient was the oldest to be diagnosed with gastric cancer with main portal vein tumor thrombus at diagnosis, who survived >36 months. Although gastric cancer with main portal vein tumor thrombus is a rare occurrence, its prognosis is extremely poor. Intensive surgery and long-term chemotherapy may be effective at improving survival time in these patients. PMID:27318995

  1. Variation in the Oral Processing of Everyday Meals Is Associated with Fullness and Meal Size; A Potential Nudge to Reduce Energy Intake?

    PubMed Central

    Ferriday, Danielle; Bosworth, Matthew L.; Godinot, Nicolas; Martin, Nathalie; Forde, Ciarán G.; Van Den Heuvel, Emmy; Appleton, Sarah L.; Mercer Moss, Felix J.; Rogers, Peter J.; Brunstrom, Jeffrey M.

    2016-01-01

    Laboratory studies have demonstrated that experimental manipulations of oral processing can have a marked effect on energy intake. Here, we explored whether variations in oral processing across a range of unmodified everyday meals could affect post-meal fullness and meal size. In Study 1, female participants (N = 12) attended the laboratory over 20 lunchtime sessions to consume a 400-kcal portion of a different commercially available pre-packaged meal. Prior to consumption, expected satiation was assessed. During each meal, oral processing was characterised using: (i) video-recordings of the mouth and (ii) real-time measures of plate weight. Hunger and fullness ratings were elicited pre- and post-consumption, and for a further three hours. Foods that were eaten slowly had higher expected satiation and delivered more satiation and satiety. Building on these findings, in Study 2 we selected two meals (identical energy density) from Study 1 that were equally liked but maximised differences in oral processing. On separate days, male and female participants (N = 24) consumed a 400-kcal portion of either the “fast” or “slow” meal followed by an ad libitum meal (either the same food or a dessert). When continuing with the same food, participants consumed less of the slow meal. Further, differences in food intake during the ad libitum meal were not compensated at a subsequent snacking opportunity an hour later. Together, these findings suggest that variations in oral processing across a range of unmodified everyday meals can affect fullness after consuming a fixed portion and can also impact meal size. Modifying food form to encourage increased oral processing (albeit to a lesser extent than in experimental manipulations) might represent a viable target for food manufacturers to help to nudge consumers to manage their weight. PMID:27213451

  2. Variation in the Oral Processing of Everyday Meals Is Associated with Fullness and Meal Size; A Potential Nudge to Reduce Energy Intake?

    PubMed

    Ferriday, Danielle; Bosworth, Matthew L; Godinot, Nicolas; Martin, Nathalie; Forde, Ciarán G; Van Den Heuvel, Emmy; Appleton, Sarah L; Mercer Moss, Felix J; Rogers, Peter J; Brunstrom, Jeffrey M

    2016-01-01

    Laboratory studies have demonstrated that experimental manipulations of oral processing can have a marked effect on energy intake. Here, we explored whether variations in oral processing across a range of unmodified everyday meals could affect post-meal fullness and meal size. In Study 1, female participants (N = 12) attended the laboratory over 20 lunchtime sessions to consume a 400-kcal portion of a different commercially available pre-packaged meal. Prior to consumption, expected satiation was assessed. During each meal, oral processing was characterised using: (i) video-recordings of the mouth and (ii) real-time measures of plate weight. Hunger and fullness ratings were elicited pre- and post-consumption, and for a further three hours. Foods that were eaten slowly had higher expected satiation and delivered more satiation and satiety. Building on these findings, in Study 2 we selected two meals (identical energy density) from Study 1 that were equally liked but maximised differences in oral processing. On separate days, male and female participants (N = 24) consumed a 400-kcal portion of either the "fast" or "slow" meal followed by an ad libitum meal (either the same food or a dessert). When continuing with the same food, participants consumed less of the slow meal. Further, differences in food intake during the ad libitum meal were not compensated at a subsequent snacking opportunity an hour later. Together, these findings suggest that variations in oral processing across a range of unmodified everyday meals can affect fullness after consuming a fixed portion and can also impact meal size. Modifying food form to encourage increased oral processing (albeit to a lesser extent than in experimental manipulations) might represent a viable target for food manufacturers to help to nudge consumers to manage their weight. PMID:27213451

  3. CT Findings of Intrarenal Yolk Sac Tumor with Tumor Thrombus Extending into the Inferior Vena Cava: A Case Report

    PubMed Central

    Lin, ShaoChun; Li, XueHua; Feng, ShiTing; Peng, ZhenPeng; Huang, SiYun; Li, ZiPing

    2014-01-01

    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. PMID:25246826

  4. Early thrombus formation in patient with HeartWare left ventricular assist device presenting with acute heart failure

    PubMed Central

    Ucar, Mustafa; Karakas, Mustafa Serkan; Bayrak, Murat; Altekin, Refik Emre; Koksel, Umut; Bayezid, Omer

    2015-01-01

    Heart failure is one of the leading causes of mortality and morbidity in the world. Heart transplantation is still the gold standard therapy despite emerging treatment options. Due to the limited number of available donors, the use of ventricular assist devices has increased. However, increasing incidences of complications are observed with using these devices. In this article, surgical treatment of a huge mobile thrombus formation in an inflow cannula due to ineffective anticoagulation in a 59 year-old man who received a HeartWare ventricular assist device because of ischemic cardiomyopathy is presented. PMID:26778905

  5. Early thrombus formation in patient with HeartWare left ventricular assist device presenting with acute heart failure.

    PubMed

    Ucar, Mustafa; Karakas, Mustafa Serkan; Bayrak, Murat; Altekin, Refik Emre; Koksel, Umut; Bayezid, Omer

    2016-01-01

    Heart failure is one of the leading causes of mortality and morbidity in the world. Heart transplantation is still the gold standard therapy despite emerging treatment options. Due to the limited number of available donors, the use of ventricular assist devices has increased. However, increasing incidences of complications are observed with using these devices. In this article, surgical treatment of a huge mobile thrombus formation in an inflow cannula due to ineffective anticoagulation in a 59 year-old man who received a HeartWare ventricular assist device because of ischemic cardiomyopathy is presented. PMID:26778905

  6. Anti-oxidant ebselen delays microvascular thrombus formation in the rat cremaster muscle by inhibiting platelet P-selectin expression.

    PubMed

    Lindenblatt, Nicole; Schareck, Wolfgang; Belusa, Lorenz; Nickels, Ruth Maria; Menger, Michael Dieter; Vollmar, Brigitte

    2003-11-01

    Ebselen, a seleno-organic compound showing glutathione per-oxidase-like activity, has potent anti-inflammatory and anti-oxidant effects. Since selenium deficiency is thought to be associated with an increased incidence of vascular thrombosis, we studied the effect of ebselen on blood cell aggregate formation and vessel occlusion in vivo. In individual microvessels of rat cremaster muscle preparations, photochemically induced thrombus formation was analyzed in detail using intravital fluorescence microscopy. In ebselen-pretreated animals (30 mg/kg ip), venular thrombus formation was significantly delayed (50% vessel occlusion: 535+/-34 s; initial stasis: 872+/-82 s; complete occlusion: 908+/-87 s) as compared to vehicle-treated controls (416+/-42; 612+/-49; 647+/-51). Moreover, ebselen significantly prolonged the kinetics of arteriolar thrombus formation and even completely prevented blood cell aggregate and thrombus formation in 88.9% of all arterioles studied (p<0.05 vs controls: 37.5%). Anti-thrombotic properties of ebselen could also be observed in a model of ferric chloride-induced microvascular thrombosis, with a low dose (5 mg/kg ip) being as effective as a high dose pretreatment (30 mg/kg ip). As assessed by flow cytometry of platelet P-selectin immunfluorescence, whole blood isolated from ebselen-treated animals revealed a significantly lower fraction of P-selectin expressing platelets when compared with that of DMSO-treated controls. In addition, oxidant stress-induced upregulation of P-selectin on isolated platelets was found dose-dependently inhibited by increasing concentrations of ebselen (10-100 micro M). Moreover, ebselen dose-dependently inhibited H(2)O(2)-induced platelet-leukocyte aggregate formation in whole blood in vitro, suggesting that the anti-thrombotic effect of ebselen is achieved by attenuation of P-selectin dependent platelet-leukocyte aggregation. Thus, ebselen represents preventive and therapeutic value for disorders with increased

  7. Exposure to rosiglitazone, a PPAR-γ agonist, in late gestation reduces the abundance of factors regulating cardiac metabolism and cardiomyocyte size in the sheep fetus.

    PubMed

    Lie, Shervi; Hui, Melisa; McMillen, I Caroline; Muhlhausler, Beverly S; Posterino, Giuseppe S; Dunn, Stacey L; Wang, Kimberley C; Botting, Kimberley J; Morrison, Janna L

    2014-03-15

    It is unknown whether cardiomyocyte hypertrophy and the transition to fatty acid oxidation as the main source of energy after birth is dependent on the maturation of the cardiomyocytes' metabolic system, or on the limitation of substrate availability before birth. This study aimed to investigate whether intrafetal administration of a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, rosiglitazone, during late gestation can stimulate the expression of factors regulating cardiac growth and metabolism in preparation for birth, and the consequences of cardiac contractility in the fetal sheep at ∼140 days gestation. The mRNA expression and protein abundance of key factors regulating growth and metabolism were quantified using quantitative RT-PCR and Western blot analysis, respectively. Cardiac contractility was determined by measuring the Ca(2+) sensitivity and maximum Ca(2+)-activated force of skinned cardiomyocyte bundles. Rosiglitazone-treated fetuses had a lower cardiac abundance of insulin-signaling molecules, including insulin receptor-β, insulin receptor substrate-1 (IRS-1), phospho-IRS-1 (Tyr-895), phosphatidylinositol 3-kinase (PI3K) regulatory subunit p85, PI3K catalytic subunit p110α, phospho-3-phosphoinositide-dependent protein kinase 1 (Ser-241), protein kinase B (Akt-1), phospho-Akt (Ser-273), PKCζ, phospho-PKCζ(Thr-410), Akt substrate 160 kDa (AS160), phospho-AS160 (Thr-642), and glucose transporter type-4. Additionally, cardiac abundance of regulators of fatty acid β-oxidation, including adiponectin receptor 1, AMPKα, phospho-AMPKα (Thr-172), phospho-acetyl CoA carboxylase (Ser-79), carnitine palmitoyltransferase-1, and PGC-1α was lower in the rosiglitazone-treated group. Rosiglitazone administration also resulted in a decrease in cardiomyocyte size. Rosiglitazone administration in the late-gestation sheep fetus resulted in a decreased abundance of factors regulating cardiac glucose uptake, fatty acid β-oxidation, and

  8. Design Modifications for Increasing the BOM and EOM Power Output and Reducing the Size and Mass of RTG for the Pluto Mission

    SciTech Connect

    Schock, Alfred; Or, Chuen T; Kumar, Vasanth

    1994-06-01

    A companion paper analyzed the effect on source modules for three specific fuel options, and compared the predicted power output with JPL's latest goals for the Pluto Fast Flyby (PFF) mission. The results showed that a 5-module RTG cannot fully meet JPL's goals with any of the available fuels; and that a 6-module RTG more than meets those goals with Russian fuel, almost meets them with U.S. (Cassini-type) fuel, but still falls far short of meeting them with the depleted fuel from the aged (1982) Galileo spare RTG. The inadequacy of the aged fuel was disappointing,because heat source modules made from it already exist, and their use in PFF could result in substantial cost savings. The present paper describes additional analyses which showed that a six-module RTG with the aged fuel can meet JPL's stipulated power margin with a relatively simple design modification, that a second design modification makes it possible to recover all of the mass and size penalty for going from five to six heat source modules, and that a third modification could raise the EOM power margin to 16%. There are four copies in the file. Cross Reference ESD Files FSC-ESD-217-94-531 (CID #8572)

  9. Design Modifications for Increasing the BOm and EOM Power Output and Reducing the Size and Mass of RTG for the Pluto Mission

    SciTech Connect

    Schock, Alfred; Or, Chuen T; Kumar, Vasanth

    1994-08-01

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. A companion paper analyzed the effect on source modules for three specific fuel options, and compared the predicted power output with JPL's latest goals for the Pluto Fast Flyby (PFF) mission. The results showed that a 5-module RTG cannot fully meet JPL's goals with any of the available fuels; and that a 6-module RTG more than meets those goals with Russian fuel, almost meets them with U.S. (Cassini-type) fuel, but still falls far short of meeting them with the depleted fuel from the aged (1982) Galileo spare RTG. The inadequacy of the aged fuel was disappointing,because heat source modules made from it already exist, and their use in PFF could result in substantial cost savings. The present paper describes additional analyses which showed that a six-module RTG with the aged fuel can meet JPL's stipulated power margin with a relatively simple design modification, that a second design modification makes it possible to recover all of the mass and size penalty for going from five to six heat source modules, and that a third modification could raise the EOM power margin to 16%.

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

    PubMed Central

    Peng, Yuandong; Guchhait, Prasenjit

    2016-01-01

    Background 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. Methods and Results 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. Conclusions and Significance 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. PMID:27105433

  11. Patterns of ST segment resolution after guidewire passage and thrombus aspiration in primary percutaneous coronary intervention (PPCI) for acute myocardial infarction

    PubMed Central

    Russhard, Paul; Al Janabi, Firas; Parker, Michael; Clesham, Gerald J

    2016-01-01

    Background ST segment elevation allows the rapid identification of patients with acute myocardial infarction who benefit from emergency reperfusion. Primary percutaneous coronary intervention (PPCI) has emerged as the preferred perfusion strategy for patients presenting with ST segment elevation myocardial infarction (STEMI). Methods and results We studied the effects of the simple passage of an angioplasty guidewire followed by mechanical thrombus aspiration on the ST segment displacement in 289 patients presenting with acute STEMI. Simple guidewire passage led to a statistically significant fall in the mean ST elevation from 5.9 to 4.9 mm (p<0.001), but the mean ST displacement after subsequent mechanical thrombus aspiration was 4.8 mm, not statistically significantly different from guidewire passage. When compared with simple guidewire passage, thrombus aspiration resulted in more patients achieving more than 50% ST resolution (21.8% vs 15.2%, p=0.009), but a higher proportion had a worsening of ST elevation compared to baseline (19.7% vs 13.5%, p=0.041). Conclusions Mechanical thrombus aspiration in acute STEMI did not improve the mean ST resolution compared with simple guidewire passage. Thrombus aspiration increased the proportion achieving 50% resolution but also increased the proportion who had a worsening of ST elevation. These data may help explain some of the uncertainties surrounding the routine use of thrombus aspiration in STEMI and potentially supports the use of ‘time to angioplasty guidewire passage’ as one of the ways to judge the promptness of PPCI services. PMID:27335657

  12. PAK1-deficiency/down-regulation reduces brood size, activates HSP16.2 gene and extends lifespan in Caenorhabditis elegans.

    PubMed

    Yanase, S; Luo, Y; Maruta, H

    2013-02-01

    There is an increasing evidence that the oncogenic kinase PAK1 is responsible not only for malignant transformation, but also for several other diseases such as inflammatory diseases (asthma and arthritis), infectious diseases including malaria, AIDS, and flu, as well as a series of neuronal diseases/disorders (neurofibromatosis, tuberous sclerosis, Alzheimer's diseases, Huntington's disease, epilepsy, depression, learning deficit, etc.) which often cause premature death. Interestingly, a few natural PAK1-blockers such as curcumin, caffeic acid (CA) and rosmarinic acid (RA) extend the lifespan of the nematode Caenorhabditis elegans or fruit flies. Here, to explore the possibility that C. elegans could provide us with a quick and inexpensive in vivo screening system for a series of more potent but safe (non-toxic) PAK1-blocking therapeutics, we examined the effects of PAK1-deficiency or down-regulation on a few selected functions of this worm, including reproduction, expression of HSP16.2 gene, and lifespan. In short, we found that PAK1 promotes reproduction, whereas it inactivates HSP16.2 gene and shortens lifespan, as do PI-3 kinase (AGE-1), TOR, and insulin-like signalling /ILS (Daf-2) in this worm. These findings not only support the "trade-off" theory on reproduction versus lifespan, but also suggest the possibility that the reduced reproduction (or HSP16.2 gene activation) of this worm could be used as the first indicator of extended lifespan for a quick in vivo screening for PAK1-blockers. PMID:23524941

  13. Manual Thrombus Aspiration and the Improved Survival of Patients With Unstable Angina Pectoris Treated With Percutaneous Coronary Intervention (30 Months Follow-Up)

    PubMed Central

    Yildiz, Bekir S.; Bilgin, Murat; Zungur, Mustafa; Alihanoglu, Yusuf I.; Kilic, Ismail D.; Buber, Ipek; Ergin, Ahmet; Kaftan, Havane A.; Evrengul, Harun

    2016-01-01

    Abstract The clinical effect of intracoronary thrombus aspiration during percutaneous coronary intervention in patients with unstable angina pectoris is unknown. In this study, we aimed to assess how thrombus aspiration during percutaneous coronary intervention affects in-hospital and 30-month mortality and complications in patients with unstable angina pectoris. We undertook an observational cohort study of 645 consecutive unstable angina pectoris patients who had performed percutaneous coronary intervention from February 2011 to March 2013. Before intervention, 159 patients who had culprit lesion with thrombus were randomly assigned to group 1 (thrombus aspiration group) and group 2 (stand-alone percutaneous coronary intervention group). All patients were followed-up 30 months until August 2015. Thrombus aspiration was performed in 64 patients (46%) whose cardiac markers (ie, creatinine kinase [CK-MB] mass and troponin T) were significantly lower after percutaneous coronary intervention than in those of group 2 (CK-MB mass: 3.80 ± 1.11 vs 4.23 ± 0.89, P = 0.012; troponin T: 0.012 ± 0.014 vs 0.018 ± 0.008, P = 0.002). Left ventricular ejection fraction at 6, 12, and 24 months postintervention was significantly higher in the group 1. During a mean follow-up period of 28.87 ± 6.28 months, mortality rates were 6.3% in the group 1 versus 12.9% in the group 2. Thrombus aspiration was also associated with significantly less long-term mortality in unstable angina pectoris patients (adjusted HR: 4.61, 95% CI: 1.16–18.21, P = 0.029). Thrombus aspiration in the context of unstable angina pectoris is associated with a limited elevation in cardiac enzymes during intervention that minimises microembolization and significantly improves both of epicardial flow and myocardial perfusion, as shown by angiographic TIMI flow grade and frame count. Thrombus aspiration during percutaneous coronary intervention in unstable angina pectoris patients

  14. An encodable lanthanide binding tag with reduced size and flexibility for measuring residual dipolar couplings and pseudocontact shifts in large proteins.

    PubMed

    Barb, Adam W; Subedi, Ganesh P

    2016-01-01

    Metal ions serve important roles in structural biology applications from long-range perturbations seen in magnetic resonance experiments to electron-dense signatures in X-ray crystallography data; however, the metal ion must be secured in a molecular framework to achieve the maximum benefit. Polypeptide-based lanthanide-binding tags (LBTs) represent one option that can be directly encoded within a recombinant protein expression construct. However, LBTs often exhibit significant mobility relative to the target molecule. Here we report the characterization of improved LBTs sequences for insertion into a protein loop. These LBTs were inserted to connect two parallel alpha helices of an immunoglobulin G (IgG)-binding Z domain platform. Variants A and B bound Tb(3+) with high affinity (0.70 and 0.13 μM, respectively) and displayed restricted LBT motion. Compared to the parent construct, the metal-bound A experienced a 2.5-fold reduction in tag motion as measured by magnetic field-induced residual dipolar couplings and was further studied in a 72.2 kDa complex with the human IgG1 fragment crystallizable (IgG1 Fc) glycoprotein. The appearance of both pseudo-contact shifts (-0.221 to 0.081 ppm) and residual dipolar couplings (-7.6 to 14.3 Hz) of IgG1 Fc resonances in the IgG1 Fc:(variant A:Tb(3+))2 complex indicated structural restriction of the LBT with respect to the Fc. These studies highlight the applicability of improved LBT sequences with reduced mobility to probe the structure of macromolecular systems. PMID:26728077

  15. Subcutaneous Injections of the Mannose-Sensitive Hemagglutination Pilus Strain of Pseudomonas aeruginosa Stimulate Host Immunity, Reduce Bladder Cancer Size and Improve Tumor Survival in Mice.

    PubMed

    Li, Tao; Yang, Li; Fu, Sheng-Jun; Xiao, Er-Long; Yuan, Xuan; Lu, Jian-Zhong; Ma, Bao-Liang; Shi, Ting-Kai; Wang, Zhi-Ping

    2015-09-01

    We wished to evaluate the effects of Pseudomonas aeruginosa (mannose-sensitive hemagglutination pilus strain, PA-MSHA) as an immunostimulating and anti-tumor agent for treatment of bladder cancer. Immunostimulating effects were assessed by the in vitro proliferation assay of murine splenic lymphocytes. Anti-tumor effects were studied in a subcutaneous tumor model established in female C57BL/6 mice using the MB49 bladder cell line. These mice received subcutaneous injections of normal saline (control group) or PA-MSHA (high, medium, or low dose, respectively, 1.6-2.0 × 10(9), 3.2- .0 × 10(8), 6.4-8.0 × 10(7) CFU/ml) twice a week for 3 weeks. Mice survival, tumor volume, vascular endothelial growth factor (VEGF) expression, microvessel density (MVD), serum levels of TNF-α and IFN-γ, and blood CD4(+) /CD8(+) counts were the study outcomes. We observed that PA-MSHA promoted the growth of splenic lymphocytes in vitro. In the murine tumor model, PA-MSHA prolonged mice survival and reduced tumor growth. Furthermore, VEGF and MVD were also diminished by PA-MSHA. Mice that received high and medium dose of PA-MSHA had significantly higher serum levels of IFN-γ and TNF-α (days 21 and 28), and higher levels of CD4(+) /CD8(+) cells (days 21 and 28). In conclusion, PA-MSHA exerts beneficial effects on increasing proliferation of murine splenic lymphocytes in vitro and inhibits the growth of bladder tumor in a murine model. Therefore, PA-MSHA may be useful an immunostimulating and anti-tumor agent for bladder cancer therapy. PMID:25724441

  16. Laser-Activated Shape Memory Polymer Microactuator for Thrombus Removal Following Ischemic Stroke: Preliminary In Vitro Analysis

    SciTech Connect

    Small, W; Metzger, M F; Wilson, T S; Maitland, D J

    2004-09-23

    Due to the narrow (3-hour) treatment window for effective use of the thrombolytic drug recombinant tissue-type plasminogen activator (rt-PA), there is a need to develop alternative treatments for ischemic stroke. We are developing an intravascular device for mechanical thrombus removal using shape memory polymer (SMP). We propose to deliver the SMP microactuator in its secondary straight rod form (length = 4 cm, diameter = 350 {micro}m) through a catheter distal to the vascular occlusion. The microactuator, which is mounted on the end of an optical fiber, is then transformed into its primary corkscrew shape by laser heating (diode laser, {lambda} = 800 nm) above its soft phase glass transition temperature (T{sub gs} = 55 C). Once deployed, the microactuator is retracted and the captured thrombus is removed to restore blood flow. The SMP is doped with indocyanine green (ICG) dye to increase absorption of the laser light. Successful deployment of the microactuator depends on the optical properties of the ICG-doped SMP and the optical coupling efficiency of the interface between the optical fiber and the SMP. Spectrophotometry, thermal imaging, and computer simulation aided the initial design effort and continue to be useful tools for optimization of the dye concentration and laser power. Thermomechanical testing was performed to characterize the elastic modulus of the SMP. We have demonstrated laser-activation of the SMP microactuator in air at room temperature, suggesting this concept is a promising therapeutic alternative to rt-PA.

  17. Inhibitory effect of caffeic acid on ADP-induced thrombus formation and platelet activation involves mitogen-activated protein kinases

    PubMed Central

    Lu, Yu; Li, Quan; Liu, Yu-Ying; Sun, Kai; Fan, Jing-Yu; Wang, Chuan-She; Han, Jing-Yan

    2015-01-01

    Caffeic acid (CA), one of the active constituents of Radix Salvia miltiorrhizae, exhibits antioxidant and anti-inflammatory activities. However, few studies have assessed the ability of CA to inhibit platelet mediated thrombus generation in vivo. In this study, we investigated the antithrombotic effect of CA in mouse cerebral arterioles and venules using intravital microscopy. The antiplatelet activity of CA in ADP stimulated mouse platelets in vitro was also examined in attempt to explore the underlying mechanism. Our results demonstrated that CA (1.25–5 mg/kg) significantly inhibited thrombus formation in vivo. In vitro, CA (25–100 μM) inhibited ADP-induced platelet aggregation, P-selectin expression, ATP release, Ca2+ mobilization, and integrin αIIbβ3 activation. Additionally, CA attenuated p38, ERK, and JNK activation, and enhanced cAMP levels. Taken together, these data provide evidence for the inhibition of CA on platelet-mediated thrombosis in vivo, which is, at least partly, mediated by interference in phosphorylation of ERK, p38, and JNK leading to elevation of cAMP and down-regulation of P-selectin expression and αIIbβ3 activation. These results suggest that CA may have potential for the treatment of aberrant platelet activation-related diseases. PMID:26345207

  18. Deficiency of Src homology 2 domain–containing inositol 5-phosphatase 1 affects platelet responses and thrombus growth

    PubMed Central

    Séverin, Sonia; Gratacap, Marie-Pierre; Lenain, Nadège; Alvarez, Laetitia; Hollande, Etienne; Penninger, Josef M.; Gachet, Christian; Plantavid, Monique; Payrastre, Bernard

    2007-01-01

    Platelets are critical for normal hemostasis. Their deregulation can lead to bleeding or to arterial thrombosis, a primary cause of heart attack and ischemic stroke. Src homology 2 domain–containing inositol 5-phosphatase 1 (SHIP1) is a 5-phosphatase capable of dephosphorylating the phosphatidylinositol 3,4,5-trisphosphate second messenger into phosphatidylinositol 3,4-bisphosphate. SHIP1 plays a critical role in regulating the level of these 2 lipids in platelets. Using SHIP1-deficient mice, we found that its loss affects platelet aggregation in response to several agonists with minor effects on fibrinogen binding and β3 integrin tyrosine phosphorylation. Accordingly, SHIP1-null mice showed defects in arterial thrombus formation in response to a localized laser-induced injury. Moreover, these mice had a prolonged tail bleeding time. Upon stimulation, SHIP1-deficient platelets showed large membrane extensions, abnormalities in the open canalicular system, and a dramatic decrease in close cell-cell contacts. Interestingly, SHIP1 appeared to be required for platelet contractility, thrombus organization, and fibrin clot retraction. These data indicate that SHIP1 is an important element of the platelet signaling machinery to support normal hemostasis. To our knowledge, this is the first report unraveling an important function of SHIP1 in the activation of hematopoietic cells, in contrast to its well-documented role in the negative regulation of lymphocytes. PMID:17347685

  19. Detection of lower limb deep venous thrombosis in asymptomatic high risk patients using a new radiolabelled thrombus specific agent

    SciTech Connect

    Butler, S.P.; Rahman, T.; Boyd S.J.

    1995-05-01

    Deep venous thrombosis is a serious consequence of major orthopaedic surgery and non invasive screening with either venous ultrasound or impedance plethysmography is unreliable for detecting or excluding DVT in this group. A new method of thrombus detection has been devised using Tc-99m labelled inhibited recombinant tissue plasminogen activator. The accuracy of scanning with this new radiopharmaceutical in asymptomatic high risk patients was evaluated using venography as the gold standard. 36 consecutive asymptomatic high risk patients (17 total hip, 19 total knee replacements) underwent both a contrast venogram on the operated leg and scintigraphic scan 7 days following operation. Scintigraphic imaging was performed at 4 hours post injection. For the purpose of this analysis, each venogram was divided into a proximal and a distal segment. Venograms were interpreted as being positive, negative or uninterpretable in each segment. Similar analysis of the scintigraphic scans was performed except that all segments were considered to be of diagnostic quality. 57 segments were able to be analysed. Of the 13 thrombosed segments (1 proximal, 12 calf), 12 had positive scans; in the 44 non thrombosed segments, 40 had negative scans. Thus in detecting lower limb thrombosis, scanning had a sensitivity of 92% and a specificity of 91%. Scintigraphic scanning with this new radiopharmaceutical permits accurate detection of thrombus in high risk patients.

  20. Right Ventricular Thrombus and Cerebral Artery Aneurysm in a Patient with Behçet’s Disease

    PubMed Central

    Sabzi, Feridoun; Mirzaei, Samaneh; Faraji, Reza

    2016-01-01

    We report a 35-year-old woman referred to the Imam Ali Hospital, Kermanshah, Iran, in July 2014 for evaluation of postoperative dyspnoea after neurosurgery performed seven days previously for a ruptured cerebral artery aneurysm. She was known to have Behçet’s disease with a history of recurrent oral and genital aphthous ulcers and uveitis. At referral, her symptoms included vertigo, dysarthria, palpitations and chest pain. Transthoracic echocardiography (TTE) revealed a large thrombus in her right ventricle outflow tract and open-heart surgery was performed eight days after the previous surgery to remove the clot. The postoperative period was complicated by transient acute renal failure, which resolved spontaneously. The patient was discharged 13 days after the cardiac surgery on warfarin, prednisolone, azathioprine and cyclophosphamide. Cyclophosphamide and azathioprine were discontinued after three months as the symptoms had completely resolved; however, prednisolone was continued due to recurrent uveitis. A 10-month follow-up TTE scan revealed no thrombus recurrence and treatment with warfarin and prednisolone was continued. PMID:27226921

  1. The differential effects of aspirin on platelets, leucocytes and vascular endothelium in an in vivo model of thrombus formation.

    PubMed

    Nagamatsu, Y; Tsujioka, Y; Hashimoto, M; Giddings, J C; Yamamoto, J

    1999-02-01

    Unanswered questions remain with regard to the therapeutic use of aspirin and the selective inhibition of thromboxane A2 and prostacyclin in platelets and endothelial cells. In the present study, the effects of aspirin on platelets and endothelial cells in vivo were examined using a helium-neon (He-Ne) laser-induced thrombosis model. Single intravenous injections of aspirin at concentrations of more than 0.5 mg/kg body weight mediated a dose dependent inhibition of thrombus formation in arterioles but not in venules. This antithrombotic effect was optimum after 15 min and declined after 90 min. Potent antithrombotic activity in arterioles was manifest at doses of 2.5 mg/kg to 50 mg/kg, and initial inhibition of thrombogenesis in vivo was most pronounced at high doses. Oral aspirin also inhibited thrombus formation in arterioles but not in venules, although the antithrombotic effects were delayed and prolonged. Maximum inhibition of ex vivo, collagen induced platelet aggregation by aspirin was observed approximately 180 min after intravenous injection. The results demonstrated that, although aspirin might have differential effects on platelets and endothelial cells, potent antithrombotic activity was manifest in arterioles at all concentrations. The findings suggest that the concept of the aspirin dilemma might be ignored for therapeutic purposes in many clinical circumstances. The antithrombotic effects of aspirin were unchanged in granulocyte-depleted animals, indicating that leucocyte-related mechanisms including neutrophil superoxide anion production did not modulate the potency of aspirin in this model. PMID:10197261

  2. Thrombus-Targeted Theranostic Microbubbles: A New Technology towards Concurrent Rapid Ultrasound Diagnosis and Bleeding-free Fibrinolytic Treatment of Thrombosis

    PubMed Central

    Wang, Xiaowei; Gkanatsas, Yannik; Palasubramaniam, Jathushan; Hohmann, Jan David; Chen, Yung Chih; Lim, Bock; Hagemeyer, Christoph E; Peter, Karlheinz

    2016-01-01

    Rationale: Myocardial infarction and stroke are leading causes of morbidity/mortality. The typical underlying pathology is the formation of thrombi/emboli and subsequent vessel occlusion. Systemically administered fibrinolytic drugs are the most effective pharmacological therapy. However, bleeding complications are relatively common and this risk as such limits their broader use. Furthermore, a rapid non-invasive imaging technology is not available. Thereby, many thrombotic events are missed or only diagnosed when ischemic damage has already occurred. Objective: Design and preclinical testing of a novel 'theranostic' technology for the rapid non-invasive diagnosis and effective, bleeding-free treatment of thrombosis. Methods and Results: A newly created, innovative theranostic microbubble combines a recombinant fibrinolytic drug, an echo-enhancing microbubble and a recombinant thrombus-targeting device in form of an activated-platelet-specific single-chain antibody. After initial in vitro proof of functionality, we tested this theranostic microbubble both in ultrasound imaging and thrombolytic therapy using a mouse model of ferric-chloride-induced thrombosis in the carotid artery. We demonstrate the reliable highly sensitive detection of in vivo thrombi and the ability to monitor their size changes in real time. Furthermore, these theranostic microbubbles proofed to be as effective in thrombolysis as commercial urokinase but without the prolongation of bleeding time as seen with urokinase. Conclusions: We describe a novel theranostic technology enabling simultaneous diagnosis and treatment of thrombosis, as well as monitoring of success or failure of thrombolysis. This technology holds promise for major progress in rapid diagnosis and bleeding-free thrombolysis thereby potentially preventing the often devastating consequences of thrombotic disease in many patients. PMID:27022419

  3. A selective, slow binding inhibitor of factor VIIa binds to a nonstandard active site conformation and attenuates thrombus formation in vivo.

    PubMed

    Olivero, Alan G; Eigenbrot, Charles; Goldsmith, Richard; Robarge, Kirk; Artis, Dean R; Flygare, John; Rawson, Thomas; Sutherlin, Daniel P; Kadkhodayan, Saloumeh; Beresini, Maureen; Elliott, Linda O; DeGuzman, Geralyn G; Banner, David W; Ultsch, Mark; Marzec, Ulla; Hanson, Stephen R; Refino, Canio; Bunting, Stuart; Kirchhofer, Daniel

    2005-03-11

    The serine protease factor VIIa (FVIIa) in complex with its cellular cofactor tissue factor (TF) initiates the blood coagulation reactions. TF.FVIIa is also implicated in thrombosis-related disorders and constitutes an appealing therapeutic target for treatment of cardiovascular diseases. To this end, we generated the FVIIa active site inhibitor G17905, which displayed great potency toward TF.FVIIa (Ki = 0.35 +/- 0.11 nM). G17905 did not appreciably inhibit 12 of the 14 examined trypsin-like serine proteases, consistent with its TF.FVIIa-specific activity in clotting assays. The crystal structure of the FVIIa.G17905 complex provides insight into the molecular basis of the high selectivity. It shows that, compared with other serine proteases, FVIIa is uniquely equipped to accommodate conformational disturbances in the Gln217-Gly219 region caused by the ortho-hydroxy group of the inhibitor's aminobenzamidine moiety located in the S1 recognition pocket. Moreover, the structure revealed a novel, nonstandard conformation of FVIIa active site in the region of the oxyanion hole, a "flipped" Lys192-Gly193 peptide bond. Macromolecular substrate activation assays demonstrated that G17905 is a noncompetitive, slow-binding inhibitor. Nevertheless, G17905 effectively inhibited thrombus formation in a baboon arterio-venous shunt model, reducing platelet and fibrin deposition by approximately 70% at 0.4 mg/kg + 0.1 mg/kg/min infusion. Therefore, the in vitro potency of G17905, characterized by slow binding kinetics, correlated with efficacious antithrombotic activity in vivo. PMID:15632123

  4. Inhibition of SA Node at Supine Position in Right Atrial Thrombus Complicating Behçet's Disease - From Cardiac Surgical Point of View.

    PubMed

    Hijazi, Emad Mohamed; Ibdah, Rasheed Khaled; Rawashdeh, Sukina Ismael; Saadeh, Abdullah Mahmoud; Al-Balas, Hamzeh Ibrahim

    2016-01-01

    BACKGROUND Behçet's disease (BD) is a chronic multi-systemic disease of unknown cause. Intra-cardiac thrombus (ICT) complicating BD is extremely rare. In general, cardiac manifestations in BD are associated with poor prognosis. Chest computed tomography (CT) scan and echocardiogram are excellent modalities for diagnosis and patient assessment. Cardiac surgical intervention can be done safely using an on-pump technique when medical management has failed. CASE REPORT We report on a case of a 27-year-old Jordanian woman diagnosed with BD who presented with dyspnea, cough, and hemoptysis, with supine bradycardia reaching 36 beats/minute and dizziness which disappear on sitting or standing position, and with heart rate reaching 76 beats/minute. Right atrial thrombus was identified using transthoracic echocardiogram and chest CT scan. After medical management failed, cardiac surgical intervention became an option and targeted extraction of the right atrial thrombus compressing the sinoatrial node (SA node). CONCLUSIONS In BD, right atrial thrombus compressing the SA node is rare. If conservative management has failed, cardiac surgical intervention removing the mechanical cause can be done safely, either using on-pump with cross clamp or on-pump with beating heart technique. PMID:27311379

  5. Disruption of de novo purine biosynthesis in Pseudomonas fluorescens Pf0-1 leads to reduced biofilm formation and a reduction in cell size of surface-attached but not planktonic cells

    PubMed Central

    Newell, Peter D.

    2016-01-01

    Pseudomonas fluorescens Pf0-1 is one of the model organisms for biofilm research. Our previous transposon mutagenesis study suggested a requirement for the de novo purine nucleotide biosynthesis pathway for biofilm formation by this organism. This study was performed to verify that observation and investigate the basis for the defects in biofilm formation shown by purine biosynthesis mutants. Constructing deletion mutations in 8 genes in this pathway, we found that they all showed reductions in biofilm formation that could be partly or completely restored by nucleotide supplementation or genetic complementation. We demonstrated that, despite a reduction in biofilm formation, more viable mutant cells were recovered from the surface-attached population than from the planktonic phase under conditions of purine deprivation. Analyses using scanning electron microscopy revealed that the surface-attached mutant cells were 25 ∼ 30% shorter in length than WT, which partly explains the reduced biomass in the mutant biofilms. The laser diffraction particle analyses confirmed this finding, and further indicated that the WT biofilm cells were smaller than their planktonic counterparts. The defects in biofilm formation and reductions in cell size shown by the mutants were fully recovered upon adenine or hypoxanthine supplementation, indicating that the purine shortages caused reductions in cell size. Our results are consistent with surface attachment serving as a survival strategy during nutrient deprivation, and indicate that changes in the cell size may be a natural response of P. fluorescens to growth on a surface. Finally, cell sizes in WT biofilms became slightly smaller in the presence of exogenous adenine than in its absence. Our findings suggest that purine nucleotides or related metabolites may influence the regulation of cell size in this bacterium. PMID:26788425

  6. Optical coherence tomography assessment of efficacy of thrombus aspiration in patients undergoing a primary percutaneous coronary intervention for acute ST-elevation myocardial infarction

    PubMed Central

    Yamaguchi, Tomoyuki; Ino, Yasushi; Matsuo, Yoshiki; Shiono, Yasutsugu; Yamano, Takashi; Taruya, Akira; Nishiguchi, Tsuyoshi; Shimokado, Aiko; Orii, Makoto; Tanaka, Atsushi; Hozumi, Takeshi; Akasaka, Takashi

    2015-01-01

    Objective We used optical coherence tomography (OCT) to assess the impact of thrombus aspiration before angioplasty on poststenting tissue protrusions in patients undergoing a primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Methods and results A total of 188 patients with STEMI who underwent thrombus-aspiration PCI (n=113) or standard PCI (n=75) were examined in this study. OCT was performed immediately after primary PCI to assess lesion morphology in the stented segment. The minimum stent area was similar between the thrombus-aspiration PCI group and the standard PCI group [7.4 interquartile range (IQR): 5.8–9.4 vs. 7.4 IQR: 5.8–8.9 mm2, P=0.788]. The maximum tissue protrusion area [0.6 (IQR: 0.3–1.1) vs. 1.2 (IQR: 0.8–1.9) mm2, P<0.001], the mean tissue protrusion area [0.1 (IQR: 0.1–0.2) vs. 0.5 (IQR: 0.3–0.8) mm2, P<0.001], and tissue protrusion volume [2.3 (IQR: 1.3–4.3) vs. 8.3 (IQR: 5.4–14.6) mm3, P<0.001] were significantly smaller in the thrombus-aspiration PCI group compared with the standard PCI group. Minimum lumen area was significantly greater in the thrombus-aspiration PCI group compared with the standard PCI group [6.9 (IQR: 5.4–8.8) vs. 6.3 (IQR: 4.6–7.8) mm2, P=0.033]. Conclusion Thrombus aspiration before angioplasty in patients with STEMI was associated with significantly smaller tissue protrusion and larger lumen poststenting compared with standard PCI. Thrombus aspiration in primary PCI favorably influenced lesion morphologies in the stented segment. PMID:26230885

  7. Reduced size fuel cell for portable applications

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor); Clara, Filiberto (Inventor); Frank, Harvey A. (Inventor)

    2004-01-01

    A flat pack type fuel cell includes a plurality of membrane electrode assemblies. Each membrane electrode assembly is formed of an anode, an electrolyte, and an cathode with appropriate catalysts thereon. The anode is directly into contact with fuel via a wicking element. The fuel reservoir may extend along the same axis as the membrane electrode assemblies, so that fuel can be applied to each of the anodes. Each of the fuel cell elements is interconnected together to provide the voltage outputs in series.

  8. A low-dose, dual-phase cardiovascular CT protocol to assess left atrial appendage anatomy and exclude thrombus prior to left atrial intervention.

    PubMed

    Lazoura, Olga; Ismail, Tevfik F; Pavitt, Christopher; Lindsay, Alistair; Sriharan, Mona; Rubens, Michael; Padley, Simon; Duncan, Alison; Wong, Tom; Nicol, Edward

    2016-02-01

    Assessment of the left atrial appendage (LAA) for thrombus and anatomy is important prior to atrial fibrillation (AF) ablation and LAA exclusion. The use of cardiovascular CT (CCT) to detect LAA thrombus has been limited by the high incidence of pseudothrombus on single-pass studies. We evaluated the diagnostic accuracy of a two-phase protocol incorporating a limited low-dose delayed contrast-enhanced examination of the LAA, compared with a single-pass study for LAA morphological assessment, and transesophageal echocardiography (TEE) for the exclusion of thrombus. Consecutive patients (n = 122) undergoing left atrial interventions for AF were assessed. All had a two-phase CCT protocol (first-past scan plus a limited, 60-s delayed scan of the LAA) and TEE. Sensitivity, specificity, diagnostic accuracy, positive (PPV) and negative predictive values (NPV) were calculated for the detection of true thrombus on first-pass and delayed scans, using TEE as the gold standard. Overall, 20/122 (16.4 %) patients had filling defects on the first-pass study. All affected the full delineation of the LAA morphology; 17/20 (85 %) were confirmed as pseudo-filling defects. Three (15 %) were seen on late-pass and confirmed as true thrombi on TEE; a significant improvement in diagnostic performance relative to a single-pass scan (McNemar Chi-square 17, p < 0.001). The sensitivity, specificity, diagnostic accuracy, PPV and NPV was 100, 85.7, 86.1, 15.0 and 100 % respectively for first-pass scans, and 100 % for all parameters for the delayed scans. The median (range) additional radiation dose for the delayed scan was 0.4 (0.2-0.6) mSv. A low-dose delayed scan significantly improves the identification of true LAA anatomy and thrombus in patients undergoing LA intervention. PMID:26420491

  9. Comparison of the usefulness of enoxaparin versus warfarin for prevention of left ventricular mural thrombus after anterior wall acute myocardial infarction.

    PubMed

    White, Derek C; Grines, Cindy L; Grines, Lorelei L; Marcovitz, Pamela; Messenger, John; Schreiber, Theodore

    2015-05-01

    Left ventricular (LV) thrombus is one of the most common complications in patients with anterior acute myocardial infarction (AMI) and LV dysfunction. Although anticoagulation is frequently prescribed, data regarding the appropriate drug, duration, risks, and effect on echocardiographic indices of thrombus are lacking. Moreover, given the difficulty in obtaining adequate anticoagulation with warfarin, it is possible that short-term treatment with a more predictable agent would be effective. We randomized 60 patients at high risk of developing LV mural thrombus (anterior acute myocardial infarction with Q waves and ejection fraction≤40%) to receive either enoxaparin 1 mg/kg (maximum 100 mg) subcutaneously every 12 hours for 30 days or traditional anticoagulation (intravenous heparin followed by oral warfarin for 3 months). Clinical evaluations and transthoracic echocardiograms were obtained at baseline, in-hospital, and at 3.5 months. There were no differences between the groups regarding baseline demographics, acute echocardiographic findings, and in-hospital outcomes. The length of hospital stay tended to be shorter for the enoxaparin group (4.6 vs 5.6; p=0.066) and the corresponding hospital costs ($25,837 vs $34,666; p=0.18). At 3 months, bleeding and thromboembolic events were rare and similar between enoxaparin and warfarin groups. Although more patients had probable mural thrombus in the enoxaparin group compared with warfarin at 3.5 months (15% vs 4%; p=0.35), this was not significantly different. In conclusion, the use of enoxaparin tends to shorten hospitalization and lower cost of care. However, at 3.5 months, there appears to be numerically higher (but statistically insignificant) rates of LV thrombus in the enoxaparin group. PMID:25765590

  10. Fibrinogen-independent platelet adhesion and thrombus formation on subendothelium mediated by glycoprotein IIb-IIIa complex at high shear rate.

    PubMed Central

    Weiss, H J; Hawiger, J; Ruggeri, Z M; Turitto, V T; Thiagarajan, P; Hoffmann, T

    1989-01-01

    Platelet adhesion and thrombus formation on subendothelium, studied at a shear rate of 2,600 s-1, were inhibited by two synthetic peptides known to interact with GPIIb-IIIa. One peptide (HHLGGAKQAGDV) corresponds to the carboxyl terminal segment of the fibrinogen gamma-chain (gamma 400-411) and the other (RGDS) contains the amino acid sequence Arg-Gly-Asp (RGD) common to fibronectin, von Willebrand factor, vitronectin and the alpha-chain of fibrinogen. Neither platelet adhesion nor thrombus formation were decreased in a patient with severe congenital fibrinogen deficiency and this was equally true when his blood was further depleted of the small amounts of fibrinogen present utilizing an anti-fibrinogen antibody. In normal subjects, adhesion and thrombus formation were inhibited by the Fab' fragments of a monoclonal anti-GPIIb-IIIa antibody (LJ-CP8), which interferes with the interaction of platelets with all four adhesive proteins in both the fluid and solid phase. However, another anti-GPIIb-IIIa antibody (LJ-P5) that had minimal effects on the interaction of platelets with fibrinogen, but inhibited to varying degrees platelet interaction with other adhesive proteins, was equally effective. The findings demonstrate that, at a shear rate of 2,600 s-1, adhesive proteins other than fibrinogen are involved in GPIIb-IIIa-mediated platelet adhesion and thrombus formation on subendothelium. In addition, since LJ-P5 inhibited the binding of soluble von Willebrand factor and vitronectin, these adhesive proteins may be involved in platelet thrombus formation. In contrast to the results obtained at a shear rate of 2,600 s-1, fibrinogen could play a role in mediating platelet-platelet interactions with weak agonists or lower shear rates. PMID:2910912

  11. Heterologous over-expression of ACC SYNTHASE8 (ACS8) in Populus tremula x P. alba clone 717-1B4 results in elevated levels of ethylene and induces stem dwarfism and reduced leaf size through separate genetic pathways.

    PubMed

    Plett, Jonathan M; Williams, Martin; LeClair, Gaetan; Regan, Sharon; Beardmore, Tannis

    2014-01-01

    Plant height is an important agronomic and horticultural trait that impacts plant productivity, durability and esthetic appeal. A number of the plant hormones such as gibberellic acid (GA), auxin and ethylene have been linked to control of plant architecture and size. Reduction in GA synthesis and auxin transport result in dwarfism while ethylene may have a permissive or repressive effect on tissue growth depending upon the age of plant tissues or the environmental conditions considered. We describe here an activation-tagged mutant of Populus tremula x P. alba clone 717-1B4 identified from 2000 independent transgenic lines due to its significantly reduced growth rate and smaller leaf size. Named dwarfy, the phenotype is due to increased expression of PtaACC SYNTHASE8, which codes for an enzyme in the first committed step in the biosynthesis of ethylene. Stems of dwarfy contain fiber and vessel elements that are reduced in length while leaves contain fewer cells. These morphological differences are linked to PtaACS8 inducing different transcriptomic programs in the stem and leaf, with genes related to auxin diffusion and sensing being repressed in the stem and genes related to cell division found to be repressed in the leaves. Altogether, our study gives mechanistic insight into the genetics underpinning ethylene-induced dwarfism in a perennial model organism. PMID:25414707

  12. Heterologous over-expression of ACC SYNTHASE8 (ACS8) in Populus tremula x P. alba clone 717-1B4 results in elevated levels of ethylene and induces stem dwarfism and reduced leaf size through separate genetic pathways

    PubMed Central

    Plett, Jonathan M.; Williams, Martin; LeClair, Gaetan; Regan, Sharon; Beardmore, Tannis

    2014-01-01

    Plant height is an important agronomic and horticultural trait that impacts plant productivity, durability and esthetic appeal. A number of the plant hormones such as gibberellic acid (GA), auxin and ethylene have been linked to control of plant architecture and size. Reduction in GA synthesis and auxin transport result in dwarfism while ethylene may have a permissive or repressive effect on tissue growth depending upon the age of plant tissues or the environmental conditions considered. We describe here an activation-tagged mutant of Populus tremula x P. alba clone 717-1B4 identified from 2000 independent transgenic lines due to its significantly reduced growth rate and smaller leaf size. Named dwarfy, the phenotype is due to increased expression of PtaACC SYNTHASE8, which codes for an enzyme in the first committed step in the biosynthesis of ethylene. Stems of dwarfy contain fiber and vessel elements that are reduced in length while leaves contain fewer cells. These morphological differences are linked to PtaACS8 inducing different transcriptomic programs in the stem and leaf, with genes related to auxin diffusion and sensing being repressed in the stem and genes related to cell division found to be repressed in the leaves. Altogether, our study gives mechanistic insight into the genetics underpinning ethylene-induced dwarfism in a perennial model organism. PMID:25414707

  13. “Soluble Tissue Factor” in the 21st Century: Definitions, Biochemistry, and Pathophysiological Role in Thrombus Formation

    PubMed Central

    Bogdanov, Vladimir Y.; Versteeg, Henri H.

    2016-01-01

    Tissue factor (TF), the main trigger of blood coagulation, is essential for normal hemostasis. Over the past 20 years, heightened intravascular levels and activity of TF have been increasingly perceived as an entity that significantly contributes to venous as well as arterial thrombosis. Various forms of the TF protein in the circulation have been described and proposed to be thrombogenic. Aside from cell and vessel wall-associated TF, several forms of non–cell-associated TF circulate in plasma and may serve as a causative factor in thrombosis. At the present time, no firm consensus exists regarding the extent, the vascular setting(s), and/or the mechanisms by which such TF forms contribute to thrombus initiation and propagation. Here, we summarize the existing paradigms and recent, sometimes paradigm-shifting findings elucidating the structural, mechanistic, and pathophysiological characteristics of plasma-borne TF. PMID:26408917

  14. Successful Percutaneous Coronary Intervention through a Severely Bent Artificial Ascending Aorta Using the DIO Thrombus Aspiration Catheter.

    PubMed

    Fujikake, Akinori; Komatsu, Takaaki; Taguchi, Isao

    2016-01-01

    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. PMID:27516912

  15. AngioVac Aspiration for Paradoxical Emboli Protection through a Fenestrated Fontan During Central Venous Thrombus Manipulation

    SciTech Connect

    Al-Hakim, Ramsey; Patel, Komal; Moriarty, John M.

    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.

  16. AngioVac Aspiration for Paradoxical Emboli Protection through a Fenestrated Fontan During Central Venous Thrombus Manipulation.

    PubMed

    Al-Hakim, Ramsey; Patel, Komal; Moriarty, John M

    2015-06-01

    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. PMID:25008372

  17. Acute free-floating carotid artery thrombus causing stroke in a young patient: unique etiology and management using endovascular approach.

    PubMed

    Tan, Ai Peng; Taneja, Manish; Seah, Boon Heng; Leong, Hoe Nam; Venketasubramanian, Narayanaswamy

    2014-01-01

    Atherosclerotic disease accounts for 20%-30% of strokes in the general population. In young adults, it is an unexpected event and its causes involve diverse pathologies. Herein, we describe a unique case of acute embolic stroke in a young adult patient due to the presence of a large clot in the right common and internal carotid arteries, as a result of an extrinsic cause. Surgical clot retrieval was considered unsafe at that point in time in view of the active inflammatory changes surrounding the affected vessels. This was eventually treated with a novel endovascular technique, a unique alternative to open surgery, with excellent clinical outcome. To our knowledge, the penumbra system has never been used for thrombus removal in a nonacute setting. PMID:25440371

  18. Horseshoe thrombus in a patient with mechanical prosthetic mitral valve: A case report and review of literature

    PubMed Central

    Mehra, Sanjay; Movahed, Assad; Espinoza, Carlos; Marcu, Constantin B

    2015-01-01

    Patients with prosthetic cardiac valves are at high risk for thromboembolic complications and need life long anticoagulation with warfarin, which can be associated with variable dose requirements and fluctuating level of systemic anticoagulation and may predispose to thromboembolic and or hemorrhagic complications. Prosthetic cardiac valve thrombosis is associated with high morbidity and mortality. A high index of suspicion is essential for prompt diagnosis. Transthoracic echocardiography, and if required transesophageal echocardiography are the main diagnostic imaging modalities. Medically stable patients can be managed with thrombolytic therapy and anticoagulation, while some patients may require surgical thrombectomy or valve replacement. We present a case report of a patient with prosthetic mitral valve and an unusually large left atrial thrombus with both thromboembolic and hemorrhagic complications. PMID:26380832

  19. Successful Percutaneous Coronary Intervention through a Severely Bent Artificial Ascending Aorta Using the DIO Thrombus Aspiration Catheter

    PubMed Central

    Fujikake, Akinori

    2016-01-01

    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. PMID:27516912

  20. α-Lipoic Acid Reduces Infarct Size and Preserves Cardiac Function in Rat Myocardial Ischemia/Reperfusion Injury through Activation of PI3K/Akt/Nrf2 Pathway

    PubMed Central

    Yi, Wei; Ma, Li; Zhao, Bijun; Cheng, Liang; Zhang, Jinzhou; Cao, Feng; Yi, Dinghua

    2013-01-01

    Background The present study investigates the effects and mechanisms of α-Lipoic acid (LA) on myocardial infarct size, cardiac function and cardiomyocyte apoptosis in rat hearts subjected to in vivo myocardial ischemia/reperfusion (MI/R) injury. Methodology/Principal Findings Male adult rats underwent 30 minutes of ischemia followed by 3, 24, or 72 h of reperfusion. Animals were pretreated with LA or vehicle before coronary artery ligation. The level of MI/R- induced LDH and CK release, infarct size, cardiomyocyte apoptosis and cardiac functional impairment were examined and compared. Western blot analysis was performed to elucidate the mechanism of LA pretreatment. The level of inflammatory cytokine TNF-α released to serum and accumulated in injured myocardium as well as neutrophil accumulation in injured myocardium were also examined after MI/R injury. Our results reveal that LA administration significantly reduced LDH and CK release, attenuated myocardial infarct size, decreased cardiomyocytes apoptosis, and partially preserved heart function. Western blot analysis showed that LA pretreatment up-regulated Akt phosphorylation and Nrf2 nuclear translocation while producing no impact on p38MAPK activation or nitric oxide (NO) production. LA pretreatment also increased expression of HO-1, a major target of Nrf2. LA treatment inhibited neutrophil accumulation and release of TNF-α. Moreover, PI3K inhibition abolished the beneficial effects of LA. Conclusions/Significance This study indicates that LA attenuates cardiac dysfunction by reducing cardiomyoctyes necrosis, apoptosis and inflammation after MI/R. LA exerts its action by activating the PI3K/Akt pathway as well as subsequent Nrf2 nuclear translocation and induction of cytoprotective genes such as HO-1. PMID:23505496

  1. Trivalent methylated arsenical-induced phosphatidylserine exposure and apoptosis in platelets may lead to increased thrombus formation

    SciTech Connect

    Bae, Ok-Nam; Lim, Kyung-Min; Chung, Jin-Ho

    2009-09-01

    Trivalent methylated metabolites of arsenic, monomethylarsonous acid (MMA{sup III}) and dimethylarsinous acid (DMA{sup III}), have been found highly reactive and toxic in various cells and in vivo animal models, suggesting their roles in the arsenic-associated toxicity. However, their effects on cardiovascular system including blood cells, one of the most important targets for arsenic toxicity, remain poorly understood. Here we found that MMA{sup III} and DMA{sup III} could induce procoagulant activity and apoptosis in platelets, which play key roles in the development of various cardiovascular diseases (CVDs) through excessive thrombus formation. In freshly isolated human platelets, treatment of MMA{sup III} resulted in phosphatidylserine (PS) exposure, a hallmark of procoagulant activation, accompanied by distinctive apoptotic features including mitochondrial membrane potential disruption, cytochrome c release, and caspase-3 activation. These procoagulant activation and apoptotic features were found to be mediated by the depletion of protein thiol and intracellular ATP, and flippase inhibition by MMA{sup III}, while the intracellular calcium increase or reactive oxygen species generation was not involved. Importantly, increased platelet procoagulant activity by MMA{sup III} resulted in enhanced blood coagulation and excessive thrombus formation in a rat in vivo venous thrombosis model. DMA{sup III} also induced PS-exposure with apoptotic features mediated by protein thiol depletion, which resulted in enhanced thrombin generation. In summary, we believe that this study provides an important evidence for the role of trivalent methylated arsenic metabolites in arsenic-associated CVDs, giving a novel insight into the role of platelet apoptosis in toxicant-induced cardiovascular toxicity.

  2. Disseminated Intravascular Coagulation with Congestive Heart Failure and Left Ventricular Thrombus: A Case Report with Literature Review of 7 Cases

    PubMed Central

    Belov, Dmitri; Lyubarova, Radmila; Fein, Steven; Torosoff, Mikhail

    2015-01-01

    Patient: Male, 55 Final Diagnosis: Disseminated intravascular coagulation Symptoms: Leg pain • short of breath • swelling legs Medication: — Clinical Procedure: — Specialty: Cardiology Objective: Unusual clinical course Background: Coagulation abnormalities can accompany acute congestive heart failure (CHF). However, disseminated intravascular coagulation (DIC) is rarely documented in such patients. DIC is characterized by generalized excessive activation of coagulation pathways followed by their depletion with secondary activation of anticoagulation and fibrinolysis. Treatment of the cause is an integral part of management of DIC; thus, recognition of the cause is critical. Case Report: A 55-year-old previously healthy man presented with breathlessness, swelling of both legs, and left leg pain. His physical exam result was consistent with decompensated heart failure. Further testing revealed multiple deep venous thrombi in the upper and lower extremities, arterial occlusion in the left popliteal artery, and an unusual cyst-like left ventricular thrombus. His laboratory evaluation was consistent with severe acute DIC. The patient was managed aggressively with diuretics, transfusions of platelets, and cryoprecipitate and was subsequently anticoagulated. His platelet count and coagulation parameters normalized and coronary angiography did not reveal any obstructive lesions. On day 22, an echocardiogram revealed and MRI confirmed that the intracardiac thrombus had disappeared. He underwent revascularization of the left leg and was successfully discharged from the hospital. Conclusions: Severe biventricular non-ischemic cardiac dysfunction with intra-cardiac thrombi should be considered in patients presenting with DIC. In addition to anticoagulation, treatment of underlying heart failure is critical in such cases. PMID:25637329

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

    SciTech Connect

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

    1989-02-01

    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.

  4. Absence of ligands bound to glycoprotein IIB-IIIA on the exposed surface of a thrombus may limit thrombus growth in flowing blood.

    PubMed Central

    Heynen, H F; Lozano Molero, M; de Groot, P G; Nieuwenhuis, H K; Sixma, J J

    1994-01-01

    We examined the distribution of glycoprotein IIb-IIIa (GPIIb-IIIa) and its ligands fibrinogen and von Willebrand factor (vWf) on platelets which had adhered under flow conditions. Immunoelectron microscopy was performed on whole mounts and frozen thin sections of adhering platelets. GPIIb-IIIa was homogeneously distributed on dendritic platelets and on interplatelet membranes of formed thrombi. Fibrinogen and vWf were predominantly associated with interplatelet membranes and membranes facing the substrate. On whole mounts, vWf appeared in clumps and linear arrays, representing the tangled or extended forms of the multimeric molecule. From semiquantitative analysis, it appeared that fibrinogen and vWf were, respectively, nine- and fourfold higher on interplatelet membranes than on surface membranes facing the blood stream, while GPIIb-IIIa was evenly distributed over all platelet plasma membranes. Ligand-induced binding sites (LIBS) of GPIIb-IIIa, as measured with conformation specific monoclonal antibodies RUU 2.41 and LIBS-1, were present on the surface of adhered platelets and thrombi. A redistribution of LIBS-positive forms of GPIIb-IIIa towards interplatelet membranes was not observed. Our data support the hypothesis that, under flow conditions, ligands have first bound to activated GPIIb-IIIa but this binding is reversed on the upper surface of adhering platelets. This relative absence of ligands on the exposed surface of thrombi may play a role in limiting their size. Images PMID:8083351

  5. Histopathological evaluation of thrombus in patients presenting with stent thrombosis. A multicenter European study: a report of the prevention of late stent thrombosis by an interdisciplinary global European effort consortium†

    PubMed Central

    Riegger, Julia; Byrne, Robert A.; Joner, Michael; Chandraratne, Sue; Gershlick, Anthony H.; ten Berg, Jurrien M.; Adriaenssens, Tom; Guagliumi, Giulio; Godschalk, Thea C.; Neumann, Franz-Josef; Trenk, Dietmar; Feldman, Laurent J.; Steg, Philippe Gabriel; Desmet, Walter; Alfonso, Fernando; Goodall, Alison H.; Wojdyla, Roman; Dudek, Dariusz; Philippi, Vanessa; Opinaldo, Sheryl; Titova, Anna; Malik, Nikesh; Cotton, James; Jhagroe, Darshni A.; Heestermans, Antonius A.C.M.; Sinnaeve, Peter; Vermeersch, Paul; Valina, Christian; Schulz, Christian; Kastrati, Adnan; Massberg, Steffen

    2016-01-01

    Background Stent thrombosis (ST) is a rare but serious complication following percutaneous coronary intervention. Analysis of thrombus composition from patients undergoing catheter thrombectomy may provide important insights into the pathological processes leading to thrombus formation. We performed a large-scale multicentre study to evaluate thrombus specimens in patients with ST across Europe. Methods Patients presenting with ST and undergoing thrombus aspiration were eligible for inclusion. Thrombus collection was performed according to a standardized protocol and specimens were analysed histologically at a core laboratory. Serial tissue cross sections were stained with haematoxylin–eosin (H&E), Carstairs and Luna. Immunohistochemistry was performed to identify leukocyte subsets, prothrombotic neutrophil extracellular traps (NETs), erythrocytes, platelets, and fibrinogen. Results Overall 253 thrombus specimens were analysed; 79 (31.2%) from patients presenting with early ST, 174 (68.8%) from late ST; 79 (31.2%) were from bare metal stents, 166 (65.6%) from drug-eluting stents, 8 (3.2%) were from stents of unknown type. Thrombus specimens displayed heterogeneous morphology with platelet-rich thrombus and fibrin/fibrinogen fragments most abundant; mean platelet coverage was 57% of thrombus area. Leukocyte infiltrations were hallmarks of both early and late ST (early: 2260 ± 1550 per mm2 vs. late: 2485 ± 1778 per mm2; P = 0.44); neutrophils represented the most prominent subset (early: 1364 ± 923 per mm2 vs. late: 1428 ± 1023 per mm2; P = 0.81). Leukocyte counts were significantly higher compared with a control group of patients with thrombus aspiration in spontaneous myocardial infarction. Neutrophil extracellular traps were observed in 23% of samples. Eosinophils were present in all stent types, with higher numbers in patients with late ST in sirolimus-and everolimus-eluting stents. Conclusion In a large-scale study of histological thrombus analysis from

  6. Dose–volume histogram parameters of high-dose-rate brachytherapy for Stage I–II cervical cancer (≤4cm) arising from a small-sized uterus treated with a point A dose-reduced plan

    PubMed Central

    Nakagawa, Akiko; Ohno, Tatsuya; Noda, Shin-ei; Kubo, Nobuteru; Kuwako, Keiko; Saitoh, Jun-ichi; Nakano, Takashi

    2014-01-01

    We investigated the rectal dose-sparing effect and tumor control of a point A dose-reduced plan in patients with Stage I–II cervical cancer (≤4 cm) arising from a small-sized uterus. Between October 2008 and August 2011, 19 patients with Stage I–II cervical cancer (≤4 cm) were treated with external beam radiotherapy (EBRT) for the pelvis and CT-guided brachytherapy. Seven patients were treated with brachytherapy with standard loading of source-dwell positions and a fraction dose of 6 Gy at point A (conventional brachy-plan). The other 12 patients with a small uterus close to the rectum or small intestine were treated with brachytherapy with a point A dose-reduction to match D2cc of the rectum and <6 Gy as the dose constraint (‘point A dose-reduced plan’) instead of the 6-Gy plan at point A (‘tentative 6-Gy plan’). The total doses from EBRT and brachytherapy were added up and normalized to a biological equivalent dose of 2 Gy per fraction (EQD2). The median doses to the high-risk clinical target volume (HR-CTV) D90 in the conventional brachy-plan, tentative 6-Gy plan and point A dose-reduced plan were 62 GyEQD2, 80 GyEQD2 and 64 GyEQD2, respectively. The median doses of rectal D2cc in the corresponding three plans were 42 GyEQD2, 62 GyEQD2 and 51 GyEQD2, respectively. With a median follow-up period of 35 months, three patients developed Grade-1 late rectal complications and no patients developed local recurrence. Our preliminary results suggested that CT-guided brachytherapy using an individualized point A dose-reduced plan might be useful for reducing late rectal complications while maintaining primary tumor control. PMID:24566721

  7. The effectiveness of antioxidant vitamins C and E in reducing myocardial infarct size in patients subjected to percutaneous coronary angioplasty (PREVEC Trial): study protocol for a pilot randomized double-blind controlled trial

    PubMed Central

    2014-01-01

    Background Acute myocardial infarction (AMI) is the leading cause of mortality worldwide. Oxidative stress has been involved in the ischemia-reperfusion injury in AMI. It has been suggested that reperfusion accounts for up to 50% of the final size of a myocardial infarct, a part of the damage likely to be prevented.Therefore, we propose that antioxidant reinforcement through vitamins C and E supplementation should protect against the ischemia-reperfusion damage, thus decreasing infarct size. The PREVEC Trial (Prevention of reperfusion damage associated with percutaneous coronary angioplasty following acute myocardial infarction) seeks to evaluate whether antioxidant vitamins C and E reduce infarct size in patients subjected to percutaneous coronary angioplasty after AMI. Methods/Design This is a randomized, 1:1, double-blind, placebo-controlled clinical trial. The study takes place at two centers in Chile: University of Chile Clinical Hospital and San Borja Arriarán Clinical Hospital. The subjects will be 134 adults with acute myocardial infarction with indication for percutaneous coronary angioplasty. This intervention is being performed as a pilot study, involving high-dose vitamin C infusion plus oral administration of vitamin E (Vitamin-treatment group) or placebo (Control group) during the angioplasty procedure. Afterward, the Vitamin-treatment group receives oral doses of vitamins C and E, and the Control group receives placebo for 84 days after coronary angioplasty. Primary outcome is infarct size, assessed by cardiac magnetic resonance (CMR), measured 6 and 84 days after coronary angioplasty. Secondary outcomes are ejection fraction, measured 6 and 84 days after coronary angioplasty with CMR, and biomarkers for oxidative stress, antioxidant status, heart damage, and inflammation, which will be measured at baseline, at the onset of reperfusion, 6 to 8 hours after revascularization, and at hospital discharge. Discussion The ischemia-reperfusion event

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