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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

    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.

  19. 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

  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. 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

  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. 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

  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. 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

  3. 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

  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. 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

  7. 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

  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. 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

  12. 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

  13. 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

  14. 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

  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. 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

  2. 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.

  3. 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

  4. 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

  5. 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.

  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. 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

  8. 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.

  9. 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

  10. 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

  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. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  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. 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

  2. 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

  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. 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

  9. 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.

  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. 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

  20. 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

  1. 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

  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. 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…

  17. 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…

  18. 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...

  19. 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…

  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. 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

  14. 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

  15. 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

  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. 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

  19. 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.

  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. 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

  6. 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

  7. 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

  8. 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

  9. 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

  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. 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

  16. 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

  17. 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

  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. 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.

  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. 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

  19. 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

  20. 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

  1. 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

  2. [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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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

  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. 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

  7. 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

  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…